Category Archives: Physiology

Physiology

The anatomy and physiology of vapes: Mods – FlipScience

This degree of adaptability is evident in the staggering diversity of mod vape hardware. There are dozensif not much, much moreof choices for a rig body and atomizer. Different brands come out with different lines, each with many different models and builds.

There are, for example, atomizers that come with prebuilt heating coils that vapers just need to replace once burnt out. Others yield even more control to the user, allowing them to assemble their own coil-and-wick setup.

In turn, this opens up layers upon layers of customization possibilities. Some coils are more resistive, have more turns, and are longer than others; some look like typical coils, while other come in mesh form. Wicks come in different materials. Some atomizers come with a tank, while others dont. Mouthpiece barrels have different allowances for airflow.

The one indispensable thing that all box modsand all vapes in generalshare is the need for e-juice. What good is a decked-out rig for if theres nothing to aerosolize?

But juices themselves are very diverse. Fundamentally, e-juices will contain some ratio of organic solvents that liquefy nicotine and carry it in the aerosols. Many different solvents can fill this role, but the most popular ones are propylene glycol and vegetable glycerin.

To add yet another layer to this variety, juices also come in many different flavors: tobacco; menthol; fruity, like mango and strawberry; and dessert, like cheesecake and cinnamon. Already,over 15,000 flavors had been documented as early as 2014, and the playing field was expanding by some 200 new flavors per month.

In a lot of ways, the market of mod vapes resembles the landscape of smartphones. The sheer number of options is daunting and overwhelming, but can also become intoxicating.

People have different needs, Jess says. For people who are just after high nicotine content, the small pods would be their best bet. The big mods and atomizers, usually those are for cloud chasers.

The dizzying variety of mod vapes shouldnt distract from the often-underplayed risks they come with, though.

Theyve been associated with explosions and poisoning, says Dr Riz Gonzalez, MD, Chairwoman of the Tobacco Control Advocacy Group of the Philippine Pediatric Society, referring to mod vapes.

Mods need regular maintenance and cleaning, particularly in its internal workings, she continues. Neglecting to do so might cause a short circuit and lead to an explosion. This may also be the case when the vape, particularly the battery, is exposed to moisture or extreme temperatures, or when improperly charged. (It is worth noting, though, that explosions have become increasingly rare, especially with the newer mods that have built-in safety features).

The coils themselves are cause for concern. During heating, they leach metallic nanoparticles into the juice, Dr Gonzalez said, and these are irritants. Several studies, indeed, have found considerable levels of metals such as aluminum, nickel, lead, copper, iron, tin, and zinc in the e-juice. And they dont just stay there. When the juice evaporates, it carries these tiny nanoparticles in the aerosols.

The microparticles float in the aerosols, and when you inhale, they go into the lungs, and lungs are only meant to inhale clean air, Dr Gonzalez explains. Anything beyond what is needed by the body, the body reacts to through inflammatory processes.

In the same way that the body tries to clot up a wound, it floods the lungs with platelets, fibrin, thrombin, and other coagulants in response to these metallic invaders. This blocks the airways. Its the same thing that happens with EVALI, she adds, referring to the e-cigarette-related lung injury epidemic that took the US by storm late last year.

This goes for e-juices, too. In fact, more particularly so. There continues to be a lot of debate about the safety of the solvents, particularly around propylene glycol and vegetable glycerin. Both have been designated by the US FDA as GRAS, or substances that are generally recognized as safe.

But Dr Gonzalez points out that these are GRAS for ingestion, not for inhalation. The cells that line the airway, after all, are different from the cells that line the stomach. It follows, too, that they respond to chemicals in different ways.

Several studies have shown, for example, that the aerosols from e-cigarettes mess with our respiratory tract even on a very basic, cellular level. Lab studies have shown that in response to these aerosols the cells that line the airway show signs of stress. Ultimately, such an exposure led to lower cell viability and an excess in the rate of cell death.

E-cigarette aerosols also assault the lungs. When exposed, in culture, to the aerosols, cells that line the tiny air sacs likewise show signs of stress and release indicators of cellular destruction. Aerosols might also make the lungs more susceptible to infection.

A 2016 study found that e-cigarette aerosols weaken the immune cells of the lungs. Mice who had inhaled these vapors showed altered inflammatory activity in their airways. To make things worse, the same type of exposure empowered Staphylococcus aureus, a common respiratory pathogen in humans. The bacteria grew more resistant to immune defenses, and became more potentsticking to the hosts cells better and entering them with greater ease.

The outbreak of EVALI late last year in the US demonstrates that what happens in the lab isnt just a test-tube artefact. Short for e-cigarette or vaping product use-associated lung injury, EVALI describes lung injuries and infections that were inexplicable except when seen in connection to the use of these devices.

Patients would present with unspecific symptoms: coughs, shortness of breath, and fevers. But in the most unfortunate cases, the disease would escalate and kill an otherwise healthy person.

Majority of cases were linked to vitamin E acetate, a common additive in juices that contained tetrahydrocannabinol, but a sizeable minority had no such connection. According to Dr Gonzalez, the culprit chemical (or chemicals) is still at large.

Though still such a very young phenomenon, there is already a substantial body of literature suggesting harms associated with vaping. It is true, however, that theres a shortage of conclusive, unassailable, clinical evidence that vaping does more harm than good. All there is, still, is smoke, not a smoking gun.

The same can be said, though, of safety. There likewise hasnt been irrefutable proof that these chemicals, and vaping in general, are completely devoid of serious health risks.

This is especially true in the face of all the flavorings. Many sweet flavors, like butter, caramel, and strawberry, owe their appeal to diacetyl, acetylpropionyl, and acetoin. Diacetyl is also GRAS for the stomach, but definitely not for the lungs. Used traditionally as the main butter flavoring in popcorn, diacetyl has since become notorious as the culprit behind bronchiolitis obliteransmore commonly known as popcorn lung.

Flavorings are also chiefly responsible for the aldehydes produced during vaping. Under heat, flavoring compounds break down into their aldehyde building blockslike formaldehyde, benzaldehyde, and acroleinin levels that exceed occupational safety thresholds.

Theres little doubt in her head that vapes will emerge more harmful than beneficial. But as of the moment, Dr Gonzalez concedes, theres no way for us know, with a comfortable degree of statistical certainty, how harmful it truly is. Its just still too early.

Maybe in a few years, she says, though even now, were starting to see some cases of COPD. Before, it [used to take] about 20 to 30 years. Vaping, in comparison, has been around 17 years, and only in the most recent handful years did it hit its stride. Its going to take time for all the chronic side effects to arise, and even more time to study and peer-review any future findings.

Unfortunately, this high bar of scientific rigor is more of a convenience than a requirement for marketing. In the face of these sparsely substantiated claims, all health advocates like Dr Gonzalez can do is call for caution and wait.

[Vapes] still do contain unidentified harmful chemicals and still-unidentified carcinogens because of the process of heating, she says. They say its for harm-reduction, but in the long run, its still really not safe.MF

Excerpt from:
The anatomy and physiology of vapes: Mods - FlipScience

Physiology

The diagnosis of the infertile couple – Contemporary Obgyn

Introduction

Many couples choose to be childless; no one chooses to be infertile. In a classic 1956 study by Alan Guttmacher examining conception rates among 5,574 women attempting pregnancy, 85% conceived within 12 months.1

However, it has also become increasingly clear that time to conception is strongly influenced by age-related factors, including declining oocyte quantity and quality over time. Indeed, Guttmacher also reported a doubling of median conception time from age 24 to 44.1

Thus, while infertility is more the lack of a normal physiological outcome than a disease per se, a thorough workup for infertility is essential to identify underlying disease. In addition, lifestyle issues and environmental factors can adversely affect infertility.

Importantly, infertility may be a marker of non-reproductive disease and often portends serious health issues. This discussion will highlight how each of these factors affect normal physiology, their diagnosis, and the treatment designed to achieve the delivery of a healthy term baby.

The breathtaking physiology of reproduction may go astray in any facet and result in infertility. Evaluation for that aberration, followed by diagnosis-specific treatment, is perhaps the most cost-effective way to help a couple conceive. This is an opportune time to add antenatal screening to the basic diagnostic evaluation of the infertile couple (Table 1).

Tubal disease is a common cause of infertility, with reported rates between 25-35% of infertility diagnoses2 though these numbers can vary widely3 depending on the population being tested. Tubal obstruction is suspected in women with a history of sexually transmitted infection, cervical dysplasia, abdominal surgery or previous intra-abdominal infection (e.g., ruptured appendix).

While laparoscopy with chromotubation is often considered the gold standard for evaluation of tubal disease, hysterosalpingography (HSG), with a sensitivity and specificity of 65% and 83%, respectively4,5 is considered the first-line diagnostic tool. 6,7

Radiopaque dye is injected into the uterus and followed through the Fallopian tubes under fluoroscopy. A similar procedure utilizing ultrasound instead of fluoroscopy, sonohysterography (SHG), is less reliable in determining tubal patency although more accurate for uterine evaluation6 with a sensitivity and specificity of 76% and 67%.8

Treatment options for tubal infertility include tubal cannulation (for proximal tubal obstruction)9, surgery for tubal reanastomosis, or in vitro fertilization (IVF), which bypasses tubal blockage, with IVF being frequently employed due to success rates and comparable costs with surgery.

Endometriosis is a complex condition characterized by the presence of endometrial tissue in sites outside the uterine cavity. Endometriosis frequently presents with pain and affects 25-40% of women with infertility.10 Posited mechanisms for the relationship between endometriosis and infertility include distortion of pelvic anatomy, tubal obstruction, impaired oocyte quality, release and pickup, and altered endometrial receptivity, although a definite cause-effect relationship between any of these pathologies and endometriosis-related infertility is controversial.

While excisional surgery has been shown to improve spontaneous pregnancy rates in women with endometriosis11, surgery is not recommended for the routine evaluation of infertility in women without other symptoms of endometriosis.12

Endometrial polyps, intracavity leiomyomas, intrauterine synechiae and Mullerian anomalies with associated distortion of the endometrial cavity may be associated with infertility.

Superior to the HSG in detecting uterine anomalies, sonohysterography detects intrauterine polyps or leiomyomas with a sensitivity and specificity of 91% and 84%, respectively.13 Direct visualization via hysteroscopy may be used to confirm the diagnosis (Figure 1). Treatment to remove the distorting mass is surgical.

The cervix is the entry to the upper reproductive tract. Its alkaline mucus protects sperm from the acidity of the vagina and guides sperm into the upper reproductive tract.

Structural alterations of the cervix, either congenital or post-surgical (for example, after loop electrosurgical excision procedure (LEEP) or large cervical cone biopsy) can cause cervical stenosis and prevent sperm entry.14

Post-operative stenosis is diagnosed by the failure to pass a 1 mm probe into the uterine cavity. The post-coital test, performed after intercourse to assess the viability of sperm in mucus, has been used to evaluate cervical function; however, the limited predictive value of this test has relegated it to history (Table 2).

In the absence of mucus and in the presence of cervical stenosis, intrauterine insemination is a successful therapy, assuming all other factors are normal.

Failure to ovulate results from a variety of non-reproductive influences including thyroid disease, pituitary disease, elevated androgens from adrenal hyperplasia, obesity, and stress. Anovulation is diagnosed by a mid-luteal serum progesterone concentration <3 ng/ml, although mid-luteal serum progesterone levels are usually higher than 7 ng/mL,15 and should be suspected when cycles are irregular and occur more often than every 21 days and less often than every 36 days.

The most common cause of anovulation is a metabolic disease, polycystic ovarian syndrome (PCOS) in which multiple follicles exist in various stages of development and are simultaneously a result of and caused by an altered hormonal milieu including insulin resistance, elevated LH, and elevated androgens.16

Women who do not ovulate do not produce progesterone and thus are at risk for the consequences of unopposed estrogen:endometrial hyperplasia and cancer.

Similarly, women with PCOS may experience non-reproductive disorders, particularly, acne, hirsutism and hyperinsulinemia. The metabolic consequences of PCOS increase a womans risk of diabetes mellitus, hyperlipidemia, gestational hypertension and gestational diabetes.

Correcting thyroid deficiency, lowering elevated prolactin, blocking elevated adrenal androgen production often stimulates ovulation. Weight loss of 15% of body weight often prompts ovulation to resume.17

Infertility associated with anovulation is best treated with ovulation induction unless other factors such as diminished ovarian reserve and male factors are present.

Female fecundity (the ability to conceive and carry a pregnancy to term) declines with increasing age, decreasing more rapidly after age 35,18,19 reflecting, in part, the progressive loss of oocytes (the ovarian reserve) that occurs with age. Aging oocytes also accumulate meiotic defects and DNA damage, causing deterioration of gamete quality and increasing the risk of aneuploid embryos and miscarriage.20,21

Therefore, women over 35 who have failed to conceive for six months should be offered expedited evaluation and treatment; for women over 40, immediate evaluation is warranted.19

Ovarian reserve refers to the number of oocytes available for stimulation and ovulation. It can be evaluated using serum FSH and estradiol concentrations on days 3-5 of a menstrual cycle, serum anti-Mllerian hormone (AMH), and/or ultrasound imaging of the ovaries for antral follicle count and ovarian volume determination (Table 3).22-26

Notably, these tests may be predictive of response to exogenous ovarian stimulation and are not predictive of live birth or even natural fertility. Accelerated oocyte loss can result in loss of fertility and early menopause (prior to age 40).

While the majority of these cases are idiopathic,27 ovarian reserve should be monitored in women with a history of prior ovarian surgery, chemotherapy, radiation therapy, or with a family history of premature menopause. These women may be at risk for carrying the fragile X (FMR1) pre-mutation and also the consequences of estrogen deprivation.

Disorders of male physiology occur in 35% of infertile couples and are the sole factor in 17% of couples.28 Similar to the female, in the male, FSH and LH stimulate the testes to produce testosterone and develop the immature gametes. Unlike the oocytes, sperm mature for three months in the male reproductive tract before being ejaculated.

Hormonal dysfunction of the male may arise from all areas of male reproductive physiology. When testosterone is low but not absent, erectile dysfunction and decreased libido commonly accompany alter semen parameters29 resulting in infertility.

Testicular failure also results in azoospermia. In addition, the concomitant lack of testosterone results in decreased libido and erectile dysfunction. As testosterone concentrations drop in the male, risk for heart disease, hyperlipidemia, osteopenia, and muscular mass loss increases.

Testosterone failure is diagnosed by a low serum testosterone and elevated LH and FSH. Of course, correcting any hormonal abnormality and screening for related disorders should precede treatment.

Diagnosis of male factor infertility begins with a well collected, comprehensive semen analysis performed in a certified andrology laboratory (Table 4). The semen sample is best collected at the laboratory, but when it must be collected at home, it should be delivered to the laboratory at body temperature within 30 to 60 minutes after ejaculation.

A diagnosis of an abnormal semen analysis should only be made after a confirmatory semen analysis has been performed, and must be interpreted in the context of the couples overall fertility evaluation. Other tests of sperm function are available, but their practical diagnostic value is subject to interpretation and are clinically not as useful.

Azoospermia is the absence of sperm in the ejaculate, not necessarily indicating an absence of sperm in the upper reproductive tract or the testes.

When the vas is patent, retrograde ejaculation may be diagnosed by retrieving sperm from the urine after orgasm and may be washed and used for intrauterine insemination. If the vas is blocked, sperm may be aspirated from the epididymis (MESA) or surgically extracted from the testes (TESA) and used for intracytoplasmic sperm injection (ICSI) at IVF.

In cases of azoospermia in which the sperm must be retrieved from the testes, testing for a mutation in the DAZ (Deleted in Azoospermia) gene can be a useful predictor of testicular sperm presence, as presence of the DAZ-c mutation predicts an almost 0% likelihood of finding sperm in the testes.30These genes may also be passed on to offspring; affected male patients may opt to use a donor sperm to prevent this outcome.

Similarly, men with an absent vas deferens may have a mutated allele for cystic fibrosis or a 5-T variant and if sperm is aspirated from the epididymis or testes for use in IVF, the resultant child may inherit cystic fibrosis.31 Thus, screening for the mutations is recommended when an absent vas deferens is detected.

Oligozoopspermia, or less than 15 million sperm/ml, and may signal partial retrograde ejaculation, hormonal disturbance or genetic conditions. If the testosterone levels are normal or low and the LH and FSH are normal, an empirical treatment with clomiphene citrate for 6 to 12 months may increase the sperm count.32

Monitoring testosterone and the semen analysis after three months is recommended. Asthenozoospermia is diagnosed when motility is < 40%, while teratospermia refers to the presence of < 4% normally formed sperm.

Male factor infertility may be treated by intrauterine insemination, possibly combined with ovulation induction of the female (COH-IUI) as discussed below. However, success rates with ICSI at IVF far exceed those with COH-IUI, especially when the normal morphology is <4% or the count is < 2million sperm/cc.

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Dr.Kallen is an assistant professor of Obstetrics, Gynecology, and Reproductive Sciences in the Division of Reproductive Endocrinology and Infertility within the Department of Obstetrics, Gynecology, and Reproductive Sciences at Yale School of Medicine, Yale University.

Dr. Carson is a professor of Obstetrics, Gynecology, and Reproductive Sciences in the Division Chief, Division of Reproductive Endocrinology and Infertility within the Department of Obstetrics, Gynecology, and Reproductive Sciences at Yale School of Medicine, Yale University.

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1. Guttmacher AF. Factors affecting normal expectancy of conception. J Am Med Assoc [Internet]. 1956 Jun 30;161(9):855860. Available from: https://doi.org/10.1001/jama.1956.02970090081016

2. American Society for Reproductive Medicine: Diagnostic evaluation of the infertile female. Fertil Steril [Internet]. Elsevier Inc.; 2015;103(6):e44e50. Available from: http://dx.doi.org/10.1016/j.fertnstert.2015.03.019

3. Audu BM, Massa AA, Bukar M, El-Nafaty AU, SaAd ST. Prevalence of utero-tubal infertility. J Obstet Gynaecol (Lahore). 2009;29(4):326328. PMID: 19835502

4. Broeze KA, Opmeer BC, Van geloven N, Coppus SFPJ, Collins JA, Den hartog JE, Van der Linden PJQ, Marianowski P, Ng EHY, Van der Steeg JW, Steures P, Strandell A, Van der Veen F, Mol BWJ. Are patient characteristics associated with the accuracy of hysterosalpingography in diagnosing tubal pathology? An individual patient data meta-analysis. Hum Reprod Update. 2011;17(3):293300.

5. Swart P, Mol BWJ, Van der Veen F, Van Beurden M, Redekop WK, Bossuyt PMM. The accuracy of hysterosalpingography in the diagnosis of tubal pathology: A meta-analysis. Fertil Steril [Internet]. Elsevier Masson SAS; 1995;64(3):486491. Available from: http://dx.doi.org/10.1016/S0015-0282(16)57781-4 PMID: 7641899

6. Kodaman P, Arici A, Seli E. Diagnosis and Management of Tubal Factor Infertility. Curr Opin Obstet Gynecol. 2004;16(3):221229.

7. Practice Committee of the American Society for Reproductive Medicine. Role of tubal surgery in the era of assisted reproductive technology: A committee opinion. Fertil Steril [Internet]. Elsevier Inc.; 2015;103(6):e37e43. Available from: http://dx.doi.org/10.1016/j.fertnstert.2015.03.032

8. Maheux-Lacroix S, Boutin A, Moore L, Bergeron ME, Bujold E, Laberge P, Lemyre M, Dodin S. Hysterosalpingosonography for diagnosing tubal occlusion in subfertile women: A systematic review with meta-analysis. Hum Reprod. 2014;29(5):953963.

9. De Silva PM, Chu JJ, Gallos ID, Vidyasagar AT, Robinson L, Coomarasamy A. Fallopian tube catheterization in the treatment of proximal tubal obstruction: A systematic review and meta-analysis. Hum Reprod. 2017;32(4):836852.

10. Ozkan S, Murk W, Arici A. Endometriosis and infertility: Epidemiology and evidence-based treatments. Ann N Y Acad Sci. 2008;1127:92100.

11. Brown J, Farquhar C. Endometriosis: An overview of Cochrane Reviews. Cochrane Database Syst Rev. 2014;2014(3). PMID: 24610050

12. American Society for Reproductive Medicine Practice Committee: Endometriosis and infertility. Fertil Steril [Internet]. American Society for Reproductive Medicine; 2012;98(3):591598. Available from: http://dx.doi.org/10.1016/j.fertnstert.2012.05.031

13. Bittencourt CA, dos Santos Simes R, Bernardo WM, Fuchs LFP, Soares Jnior JM, Pastore AR, Baracat EC. Accuracy of saline contrast sonohysterography in detection of endometrial polyps and submucosal leiomyomas in women of reproductive age with abnormal uterine bleeding: systematic review and meta-analysis. Ultrasound Obstet Gynecol. 2017;50(1):3239.

14. Boss EA, Van Golde RJT, Beerendonk CCM, Massuger LFAG. Pregnancy after radical trachelectomy: A real option? Gynecol Oncol. 2005.

15. Carmina E, Stanczyk F, Lobo R. Laboratory Assessment. In: Strauss J, Barbieri R, editors. Yen Jaffes Reprod Endocrinol Physiol Pathophysiol Clin Manag. Eighth. Elsevier; 2019. p. 887915.

16. Sirmans SM, Pate KA. Epidemiology, diagnosis, and management of polycystic ovary syndrome. Clin Epidemiol. 2013; PMID: 24379699

17. Clark AM, Ledger W, Galletly C, Tomlinson L, Blaney F, Wang X, Norman RJ. Weight loss results in significant improvement in pregnancy and ovulation rates in anovulatory obese women. Hum Reprod. 1995;10(10):27052712. PMID: 8567797

18. Laing LM. Declining Fertility in a Religious Isolate: The Hutterite Population of Alberta, Canada. Hum Biol. 1980;52(2):289310.

19. American Society for Reproductive Medicine: Female age-related fertility decline. Fertil Steril [Internet]. American Society for Reproductive Medicine; 2014;101(3):633634. Available from: http://dx.doi.org/10.1016/j.fertnstert.2013.12.032

20. Jones KT. Meiosis in oocytes: Predisposition to aneuploidy and its increased incidence with age. Hum Reprod Update. 2008;14(2):143158. PMID: 18084010

21. Oktay K, Turan V, Titus S, Stobezki R, Liu L. BRCA Mutations, DNA Repair Deficiency, and Ovarian Aging. Biol Reprod. 2015;93(3):110. PMID: 26224004

22. Tal R, Seifer DB. Ovarian reserve testing: a user s guide. Am J Obstet Gynecol [Internet]. Elsevier Inc.; 2017;217(2):129140. Available from: http://dx.doi.org/10.1016/j.ajog.2017.02.027

23. Steiner AZ, Pritchard D, Stanczyk FZ, Kesner JS, Meadows JW, Herring AH, Baird DD. Association Between Biomarkers of Ovarian Reserve and Infertility Among Older Women of Reproductive Age. Jama. 2017;318(14):13671376. PMID: 29049585

24. Hawkins Bressler L, Steiner A. Anti-Mllerian hormone as a predictor of reproductive potential. Curr Opin Endocrinol Diabetes Obes. 2018;25(6):385390.

25. Pfeifer S, Butts S, Dumesic D, Fossum G, Giudice L, Gracia C, La Barbera A, Odem R, Pisarska M, Rebar R, Richard R, Rosen M, Sandlow J, Vernon M, Widra E. Testing and interpreting measures of ovarian reserve: A committee opinion. Fertil Steril [Internet]. American Society for Reproductive Medicine; 2015;103(3):e9e17. Available from: http://dx.doi.org/10.1016/j.fertnstert.2014.12.093

26. ACOG Committee Opinion No. 773: The Use of Antimllerian Hormone in Women Not Seeking Fertility Care. Obstet Gynecol. 2019;133(4):e274e278.

27. Bachelot A, Rouxel A, Massin N, Dulon J, Courtillot C, Matuchansky C, Badachi Y, Fortin A, Paniel B, Lecuru F, Lefrere-Belda MA, Constancis E, Thibault E, Meduri G, Guiochon-Mantel A, Misrahi M, Kuttenn F, Touraine P. Phenotyping and genetic studies of 357 consecutive patients presenting with premature ovarian failure. Eur J Endocrinol. 2009;161(1):179187.

28. Odisho AY, Nangia AK, Katz PP, Smith JF. Temporal and geospatial trends in male factor infertility with assisted reproductive technology in the United States from 1999-2010. Fertil Steril. 2014;

29. Nikoobakht MR, Aloosh M, Nikoobakht N, Mehrsay A, Biniaz F, Karjalian MA. The role of hypothyroidism in male infertility and erectile dysfunction. Urol J. 2012; PMID: 22395839

30. Ferlin A, Tessari A, Ganz F, Marchina E, Barlati S, Garolla A, Engl B, Foresta C. Association or partial AZFc region deletions with spermatogenic impairment and male infertility. J Med Genet. 2005;

31. Chilln M, Casals T, Mercier B, Bassas L, Lissens W, Silber S, Romey MC, Ruiz-Romero J, Verlingue C, Claustres M, Nunes V, Frec C, Estivill X, Estivill X. Mutations in the cystic fibrosis gene in patients with congenital absence of the vas deferens. N Engl J Med. 1995;

32. Willets AE, Corbo JM, Brown JN. Clomiphene for the treatment of male infertility. Reproductive Sciences. 2013.

33. La Marca A, Sighinolfi G, Radi D, Argento C, Baraldi E, Artenisio AC, Stabile G, Volpe A. Anti-Mllerian hormone (AMH) as a predictive marker in assisted reproductive technology (ART). Hum Reprod Update. 2009;16(2):113130.

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The diagnosis of the infertile couple - Contemporary Obgyn

Physiology

Shoots and leaves: the shotgun scientist who hunts moving trees – The Guardian

Angelica Patterson is on the lookout, shotgun in hand, as she hikes through New York states Black Rock Forest. She focuses on her target high up in the canopy, then bang a branch falls to the ground. I cant climb trees, building scaffolding is expensive, and using a slingshot requires a lot of skill, she says. A shotgun is an efficient, cheap and effective way to collect the high-up leaves that have full exposure to the sun.

Patterson puts the northern red oak branch into a bucket of water, cutting the submerged stem to ensure that its leaves continue to function, before walking back to her laboratory in the forest.

Here she studies how trees adapt and move in response to increasing average air temperatures. When I first started learning about how plant communities change through time, Id never associated trees with migration because theyre sessile and dont move like four-legged creatures or fly like insects. So its eye-opening to realise that tree communities shift their ranges to migrate to places where they can thrive, says Patterson, 39, a PhD student at Columbia Universitys department of earth and environmental science.

Its as simple as seed dispersal. But just because a seed from a tree can move to a place doesnt mean it will successfully grow or reproduce. Other factors come into play in order to establish a thriving population.

Black Rock Forest is unusual because extensive data collected since the 1930s shows exactly how tree distribution has changed there. Over the past 90 years, theres been a shift in forest composition. Three species have left the region or become locally extinct and 11 have migrated in naturally from the south or been introduced anthropogenically, Patterson says. I wanted to find out what mechanism drives this shift and how that affects the ability of our forest to become a source rather than a sink of carbon dioxide, therefore perpetuating climate change.

The forests in the north-eastern US are one of the worlds fastest growing carbon stores on land as timber harvesting, large-scale agriculture and fire disturbance have declined. But a shifting forest composition could have a drastic impact on this regions carbon storage capacity if the forests carbon balance is disrupted, more carbon could be released into the atmosphere.

Northern red oaks are so important to this region, they influence soil health, water quality, nutrients. When you start to lose large populations of trees, that complex forest ecosystem can break down, says Patterson.

If an invasive tree comes into play, youll start to have a monoculture and lose that biodiversity; then the whole system just isnt healthy.

Patterson, who also works as an educator, admits she has never really been a city person. She grew up immersed in nature and trees in the rural town of Lackawaxen, Pennsylvania, and thrives in the multisensory experience of a forest. I love the calm, the peace, the intrigue; I can go for a walk and find a plant Ive never seen before or hear a new bird call, or discover a weird fungus. This forest is an amazing space to be, says Patterson, who lives just 20 minutes away. This place allows me to calm my mind but also stimulate it at the same time. Ive never found another environment that does that.

Over the past eight years she has studied how hundreds of leaves from 22 species function differently to investigate how environments that are extreme to certain species can influence the physiology of the tree. I liken it to working out which tree has the engine of a Toyota and which has the engine of a Ferrari the oaks are not Ferraris. However, they are extremely resilient and theres a reason theyve been dominant here for centuries, says Patterson, who explains the survival strategy of the northern red oak, which makes up 70% of this forest. These oaks can live up to 350 years so theyre long-lived, they produce dominant seeds [acorns] and tolerate high-stress conditions.

In the past, Black Rock Forest has been subject to fires but the oaks acorns can survive underground until conditions improve. However, now there are more settlements locally, fires are suppressed so these oaks must compete with fire-sensitive trees that would not have survived previously. More frequent tropical storms and heavy winds also threaten mature oak trees, a disease called oak blight is spreading into this region and deer browsing affects oak regeneration, potentially allowing other migrant trees to more easily fill this niche.

Kevin Griffin, professor in plant physiology at Columbia University, is Pattersons PhD supervisor. He explains why Black Rock Forest is such a significant place to study tree migration. Theres a huge mix of species here because tree species that typically have a southern or northern range all seem to crash together right in the Hudson valley, he says. At the end of the last ice age 14,000 years ago, glaciers receded from the Hudson valley and now after ecological succession were looking at this beautiful oak deciduous forest, but thats just a snapshot in time.

A plant or animals range the geographical area in which a species can be found is in constant flux. Ranges naturally shift, expand and contract over time, but it is the current speed of change that concerns scientists like Patterson and Griffin. If the rate of change [in ranges] is greatly accelerated from human activities, then how does the ecology keep up with that? asks Griffin.

For trees that grow and reproduce incredibly slowly, migration is a huge challenge. As Griffin puts it, trees dont have legs, seeds travel short distances and lots of things eat those seeds, plus trees need pollinators and the right soil for germination, so the ecology is fascinating but not obvious. Crucially, theres a mismatch between the speed at which ranges shift and the speed at which trees can respond and migrate.

Griffin and Patterson are investigating how shifting ranges affect the physiology or inner workings of these trees: Were trying to build a clearer picture of how the trees are currently surviving, how competitive they are and at what rate they may or may not be able to keep up with this shift in climatic conditions, says Griffin, who says that temperature is one of the key drivers for shifting ranges.

According to the US Forest Service Northern Research Station, more than 70% of saplings from northern tree species in the eastern US are showing a northwards migration. But temperature certainly isnt the only variable. In 2017, forest ecologist Songlin Fei at Indianas Purdue University found more species moving west than north in eastern areas, possibly due to changes in precipitation or rainfall rather than changes in temperature. Total annual rainfall in central US had increased by more than 150mm and declined significantly in the south-east.

In order to compare metabolic activity inside every leaf she collects, Patterson clamps each one into the chamber of a photosynthesis machine. I set the relative humidity, light, carbon dioxide levels and temperature to mimic the local conditions in the forest, or to recreate the southern range limit conditions, then allow each leaf to acclimatise and become happy. This encourages the stomas [pores] to open so that gas exchange can flow freely, she says. Patterson measures the rates of respiration and photosynthesis in mature trees.

Griffin likens this to a bank account: You have what you make and what you spend; tree growth is whats left over. So we study both photosynthesis how carbon gets into the tree and respiration how carbon leaves the tree to see if we can understand why some plants appear more or less successful.

In Black Rock Forest, the northern red oak is central to its range. But other broad-leaved and conifer trees found here might be living at the southern limit of their region (these northern-ranged trees include paper birch and red pine), or at the northern limit of their region (southern-ranged trees such as American sycamore and Atlantic white cedar). Pattersons initial results show that there are significant differences in the physiological capacities between northern-, central- and southern-ranged trees in Black Rock Forest.

The patterns we find suggest that resident or centrally ranged trees, such as northern red oak, are physiologically disadvantaged when compared [with] the northern- and southern-ranged trees, she says.

But the trees may have been able to adapt to current climate conditions. Within the next 50-100 years, high carbon emission scenarios predict that temperatures could feel as warm as Georgias. So the oaks ability to continue to physiologically acclimate to a warming climate and persist among disturbance regimes such as deer browsing or ice storms will [influence] the health and survival of the oak population and the carbon storage potential of this regions forests, Patterson says.

Theres also scope for this data to be incorporated into climate models so it might help predict future atmospheric carbon dioxide levels and evaluate which of the north-east US tree species may be better able to tolerate warmer climates over coming decades.

The best approach to surviving a warming climate, according to researchers, could be to maintain connective corridors to allow trees to naturally migrate to new areas in a changing future and not be stopped by artificial boundaries such as cities, lakes or farmland.

Further research by the University of Tennessee indicates that underground soil highways could also be important, with certain combinations of fungi and bacteria microbiomes encouraging heat-sensitive trees to migrate to higher elevations where they can thrive.

Ultimately, tree migration is incredibly complex. But Pattersons work represents a valuable benchmark. Having recorded GPS coordinates for every leaf studied, researchers could take further measurements to assess how tree function changes over time.

This is just a small snapshot of whats happening with certain trees, she says. But it gives insight into which species will tolerate particular environments and that could help forest management now and in the future.

Find more age of extinction coverage here, and follow biodiversity reporters Phoebe Weston and Patrick Greenfield on Twitter for all the latest news and features

Continued here:
Shoots and leaves: the shotgun scientist who hunts moving trees - The Guardian

Physiology

Researchers identify the missing link in the production of nitric oxide – News-Medical.net

Reviewed by Emily Henderson, B.Sc.Sep 14 2020

Some microorganisms, the so-called methanotrophs, make a living by oxidizing methane (CH4) to carbon dioxide (CO2). Ammonia (NH3) is structurally very similar to methane, thus methanotrophs also co-metabolize ammonia and produce nitrite.

While this process was observed in cell cultures, the underlying biochemical mechanism was not understood. Boran Kartal, head of the Microbial Physiology Group at the Max Planck Institute for Marine Microbiology in Bremen, Germany, and a group of scientists from Radboud University in Nijmegen, The Netherlands, now shed light on an exciting missing link in the process: the production of nitric oxide (NO).

Nitric oxide is a highly reactive and toxic molecule with fascinating and versatile roles in biology and atmospheric chemistry. It is a signaling molecule, the precursor of the potent greenhouse gas nitrous oxide (N2O), depletes the ozone layer in our atmosphere, and a key intermediate in the global nitrogen cycle.

It now turns out that NO is also the key for the survival of methanotrophs that face ammonia in the environment - which they do more and more as fertilizer input into nature increases. When methanotrophs co-metabolize ammonia they initially produce hydroxylamine, which inhibits other important metabolic processes, resulting in cell death.

Thus, methanotrophs need to get rid of hydroxylamine as fast as possible. "Carrying a hydroxylamine-converting enzyme is a matter of life or death for methane-eating microbes", Kartal says.

For their study, Kartal and his colleagues used a methanotrophic bacterium named Methylacidiphilum fumariolicum, which originates from a volcanic mud pot, characterized by high temperatures and low pH, in the vicinity of Mount Vesuvius in Italy.

From this microbe, we purified a hydroxylamine oxidoreductase (mHAO) enzyme. Previously it was believed that mHAO enzyme would oxidize hydroxylamine to nitrite in methanotrophs. We now showed that it actually rapidly produces NO."

Boran Kartal, Head of the Microbial Physiology Group, Max Planck Institute for Marine Microbiology

The mHAO enzyme is very similar to the one used by "actual" ammonia oxidizers, which is quite astonishing, as Kartal explains: "It is now clear that enzymatically there is not much difference between aerobic ammonia- and methane-oxidizing bacteria. Using essentially the same set of enzymes, methanotrophs can act as de facto ammonia oxidizers in the environment. Still, how these microbes oxidize NO further to nitrite remains unknown."

The adaptation of the mHAO enzyme to the hot volcanic mud pots is also intriguing, Kartal believes: "At the amino acid level, the mHAO and its counterpart from ammonia oxidizers are very similar, but the protein we isolated from M. fumariolicum thrives at temperatures up to 80 C, almost 30 C above the temperature optimum of their "actual" ammonia-oxidizing relatives. Understanding how so similar enzymes have such different temperature optima and range will be very interesting to investigate."

According to Kartal, production of NO from ammonia has further implications for methane-eating microbes: "Currently there are no known methanotrophs that can make a living out of ammonia oxidation to nitrite via NO, but there could be methanotrophs out there that found a way to connect ammonia conversion to cell growth."

Source:

Journal reference:

Versantvoort, W., et al. (2020) Multiheme hydroxylamine oxidoreductases produce NO during ammonia oxidation in methanotrophs. Proceedings of National Academy of Sciences. doi.org/10.1073/pnas.2011299117.

Link:
Researchers identify the missing link in the production of nitric oxide - News-Medical.net

Physiology

Health Makers: How the App GlucoseZone Helps People With Diabetes Exercise Safely – Everyday Health

He recalls his training schedule during college, which began with breakfast at 7 a.m. They serve bacon, egg, cheese, and fruit, and practice is at 8, he says. How much insulin do you take at breakfast?

Another example: Its 11 a.m. and youve been at practice for three hours and your blood sugar is 280 milligrams per deciliter (mg/dl). According to the American Diabetes Association, the recommended range is between 80mg/dl and 130 mg/dl. What do you do? he asks.

It was a total disaster because nobody there had a clue how to help me. I was the only athlete there with type 1 diabetes, OConnell explains.

His coaches eventually set a refrigerator aside in the training room filled with everything from maple syrup to vials of insulin. I persevered through that situation, and I love U Penn, but at the time, it was a very frustrating experience, and I felt that diabetes had really hindered my athletic potential, he says.

RELATED: 7 Tips for Staying Motivated to Exercise When Managing Diabetes

After graduation he moved to New York City, began working in tech, and quit exercising. The fear and anxiety he experienced during college worrying about hypoglycemia, or low blood sugar was so overwhelming that he lost his motivation.

The problem was that I had come to fear my relationship with exercise, OConnell says. Then I realized that I cant have something that I really love being active be dominated by fear and anxiety.

He began a personal quest to figure it out: What type of exercise should he do? Or how should he prepare for different types of exercise? Why did his blood sugar drop when he did aerobic exercise that is, workouts of low to high intensity and elevate when he did anaerobic exercise, or short bursts of high intensity.

These are detailed and challenging physiological questions that type 1 diabetics have to manage every time they do physical activity, he says. And I realized, if this has taken me three years of studying intensely and I love exercise, what about the person who just wants to do a Spin class and not have a hypoglycemic incident?

RELATED: 6 Diabetes Exercise Mistakes and How to Avoid Them

During this time, he learned about physiology and type 1 and type 2 diabetes, and began developing the foundation of the GlucoseZone algorithm, which takes independent variables like blood sugar, heart rate levels, and medication and analyzes them to make exercise recommendations.

Depending on a persons blood sugar levels, it may not be safe to exercise, OConnell says. Depending on the medication profile theyre on, it may not be safe to exercise.

GlucoseZone has teamed up with the American Diabetes Association and is being used in 20 countries. When the COVID-19 pandemic hit, he decided to offer it free for a limited time. On October 1, the app will cost $4.95, down from $12.95 before the pandemic.

People with diabetes are more susceptible to COVID-19-related issues than the general population, and they have a requirement to be physically active on a daily basis, OConnell says. My ultimate goal is to be the global resource for people living with diabetes to reach their fitness goals.

RELATED: How Exercise Helps Prevent or Manage Type 2 Diabetes

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Health Makers: How the App GlucoseZone Helps People With Diabetes Exercise Safely - Everyday Health

Physiology

Honey Bee Nutrition Might Be Key To Healthy Colonies – Texas A&M Today – Texas A&M University Today

To prevent future managed colony losses, the team will look for ways to strengthen bee colony immunity by feeding them more nutritious diets.

Getty Images

A newly fundedTexas A&M AgriLife Researchproject seeks to slow population losses among more than 2.6 million managed honey bee colonies in the U.S.

Honey bees provide pollination services that uphold $16 billion in U.S. agricultural crops. However, managed colonies have seen annual declines. Those include a 40% decline as recently as 2018-2019, said Juliana Rangel, AgriLife Research honey bee scientist in the Department of Entomology, Bryan-College Station.

The declines are attributed to several general issues, including poor nutrition and susceptibility to pathogens and diseases, said Pierre Lau, AgriLife Research graduate assistant and a Texas A&M Universitydoctoral candidate in Rangels laboratory.

Lau is also the project leader. To prevent future managed colony losses, his team will look for ways to strengthen bee colony immunity to disease pathogens by feeding them more nutritious diets.

The project is supported by aU.S. Department of Agriculture pre-doctoral fellowshiptitled Optimizing Macronutrient Contents in the Honeybee Diet as a Mechanism for Pathogen Defense.

The research team includes Lau, Texas A&M graduate student Alexandria Payne, undergraduate students Cora Garcia and Jordan Gomez, and Rangel. Spencer Behmer, AgriLife Research professor in the Texas A&M department of entomology, is also part of the team, as is his postdoctoral research associate Pierre Lesne.

Cups with different macronutrient mixes are presented to bees in these small cups.

Texas A&M AgriLif

Researchers will focus heavily on macronutrients, which are those nutrients in the highest demand by a healthy body for proper metabolism and physiology, Lau said.

His teams work will be to first understand the varying amounts of proteins and lipids, or macronutrient ratios, present in bees diets. They will work to optimize an ideal diet with varying ratios of macronutrients, then they will observe physiological benefits to bees that receive increasingly nutritious dietary mixes.

Commercial honey bee colonies succumb especially to Nosema ceranae and deformed wing virus. Nosema ceranae, a fungal pathogen, causes a fatal intestinal disease, while deformed wing virus causes death due to developmental complications in heavily infected adults, particularly due to crumpled wings.

Besides pathogens and diseases, Lau said, honey bee declines within agroecosystems which describe most agricultural crop scenarios can also come from parasitization, poor queen health, pesticide exposure and landscape fragmentation.

As such, in addition to immunity, the researchers will investigate how nutritional changes affect expression of genes that mediate proper honey bee development and growth.

We know that pollen is the most important source of nourishment for bees, but as a field of research, we have a poor understanding of all the macronutrients that make up pollen, Lau said.

At the same time, Lau and collaborators, in an unpublished study, were able to determine the nutritional content of certain pollens. In the same study, they noted that honey bees preferred pollen with a lower ratio of protein to lipids, or P:L ratio, than what would be currently available in the beekeeping industry. Moreover, Lau said, existing research shows that organisms naturally seek out pathogen-fighting nutrients in their surroundings.

Does this mean that honey bees can alter their macronutrient intake to self-medicate and increase their tolerance to a pathogen, given the availability? Lau said. It could also be that the role of lipids is more significant than we understand.

Additionally, Rangel said, honey bees need certain plants in the vicinity to help them with physiological processes. Those include metabolizing certain macro and micronutrients.

We know that honey bees need variety in their diet, Rangel said. But, to what extent are certain nutrients required, or even sought after, by the bees for proper nourishment?

Can we introduce supplemental macronutrients that allow honey bees to self-medicate in the presence of pathogen infections? Lau added. This will be our focus for the next two years.

Read more about theTexas A&M Honey Bee Research Program , and follow Rangels lab onFacebook.

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Honey Bee Nutrition Might Be Key To Healthy Colonies - Texas A&M Today - Texas A&M University Today

Physiology

HRI sheds further light on relationship between diet and cardiometabolic disease – Mirage News

Recent HRI research has validated the metabolic pathways that link dietary components with the risk of developing cardiovascular disease.

A study led by the Heart Research Institutes Dr Yen Chin Koay in collaboration with research colleagues Dr Jibran Wali and Professor Stephen Simpson from Charles Perkins Centre, The University of Sydney focuses on dimethylguanidino valeric acid (DMGV), a marker of fatty liver disease, incident coronary artery disease, cardiovascular mortality, and incident diabetes.

The research, published in The American Journal of Physiology, investigates the relationship between dietary macronutrients and circulating levels of DMGV and other related metabolites with insulin resistance.

Our research provides insight into recent observations of dietary control of this promising new marker of cardiometabolic disease and novel disease pathway, says Dr Koay, postdoctoral researcher in HRIs Cardiometabolic Disease Group led by Assoc Prof John OSullivan.

Identifying the modifiable metabolic pathways linking the dietary components of cardiometabolic disease could help to reduce disease risk and lead to new avenues for prevention.

The research measured the plasma concentrations of DMGV and its related metabolites and analysed the dietary data to validate the dietary associations in various cohorts. The results found that DMGV concentrations were significantly upregulated in people with liver or skeletal muscle insulin resistance and that DMGV levels were upregulated in lab models on a very high sucrose diet.

These results provide a comprehensive picture of the dietary determinants of DMGV levels and its association with insulin resistance, says Dr Koay.

The study also extends the clinical value of DMGV as a predictor of exercise responsiveness to global metabolic health, including ectopic lipid deposition and insulin resistance in muscle and liver.

In the next phase of research, the teams goal is to understand the mechanisms that link plasma levels of DMGV, lifestyle, and dietary interventions.

With this knowledge, we could facilitate development of strategies personalised to the individual to help prevent prediabetes in those at increased risk, states Dr Koay.

This research received an APSselect award for distinction in scholarship by The American Physiological Society.

Continued here:
HRI sheds further light on relationship between diet and cardiometabolic disease - Mirage News

Physiology

Adam delivers strong half debut; Callum on strength and conditioning – scottishathletics.org.uk

Saturday 12th September 2020

Adam Craig takes gold at Falkirk in February 2019 at the Lindsays National Xc (photo by Bobby Gavin)

Antrim Results

Adam Craig came up with a very solid half marathon debut as he clocked 63:24 at the Antrim Coast Half Marathon on Saturday morning.

The Inverclyde AC athlete finished in eighth place as Sir Mo Farah headed Marc Scott to win in 60.27.

Craig, who won the Lindsays National XC in 2019, is not far adrift of the top ten in the Scottish all-time rankings with that performance after many months of lockdown.

Inverness Harrier Sean Chalmers was the second best Scot in the Mens race in 13th place in 65:16 and he was closely followed in by James Donald with the Dundee Hawkhill Harrier at 65:27.

Kenny Wilson of Moray Road Runners recorded 67:04 and finished one place below Central AC Irish athlete, Conan McCaughey, who was home in 66:38.

Fiona Brian of Metro Aberdeen delivered the best Scottish performance in the Womens race won by Lily Partridge.

Fiona was placed sixth with a time of 75:33 and her club-mate, Ginie Barrand was 10th with 77:42. Avril Mason of Shettleston was 12th with 78:12 and Claire Bruce of Metro Aberdeen was at 82:19.

+++

Photo by Bobby Gavin

sportscotland interview with Callum

World class athlete Callum Hawkins broke the Scottish record at the London Marathon in April 2019.

He then finished fourth at the IAAF World Championships in Doha to earn pre-selection for the Tokyo 2020 Olympic Games, now due to take place in 2021.

And Callum has been speaking to sportscotland about the importance of strength and conditioning work as he targets even more consistency in his performances.

He credits the support received from thesportscotland institute of sport (SIS), working in collaboration with physical preparation coach Barry Jones as well as the performance physiology and physiotherapy teams, to help him deliver fast times.

Callum, a lifetime member of Kilbarchan AAC, said: Before, I probably dipped in and out of strength and conditioning, but Barry made me fully buy into it and it seems to have worked. I now train twice a week where possible while also getting a lot of massage and physiotherapy.

Going to Doha with the heat it was good to work with SIS physiologist Cian McGinley and Andy Shaw from British Athletics to work out plans and see what I could do in the heat and how I could handle it.

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Tags:Adam Craig, Antrim, Callum Hawkins, Fiona Brian

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Adam delivers strong half debut; Callum on strength and conditioning - scottishathletics.org.uk

Physiology

6 things to know about how wildfire smoke impacts your health – KCRA Sacramento

As Northern California sits under a thick blanket of wildfire smoke for days, many people are left wondering what the air quality means for their health.It is really bad, said Dr. Vanessa Walker. As a pulmonary physician with Sutter Health and Pulmonary Medicine Associates, Walker has treated COVID-19 patients throughout the pandemic. Recently, she has seen an uptick in smoke-related hospital visits. To provide context, she said an AQI greater than 100 is unhealthy for sensitive groups. Right now, the AQI is well over 200. So this is unhealthy for everybody no matter who you are. And unfortunately, it just seems to be getting worse especially as these wildfires are raging out of control, she said. Here are six things to know about how smoke impacts your health according to Dr. Walker:1. What are the negative impacts?Walker: If you have no lung disease, youre probably just going to notice things like eye irritation, throat irritation, scratchy nose, watery eyes. But if you have any kind of underlying lung disease, COPD, emphysema, asthma, you can cause a serious reaction like an asthma exacerbation or a COPD exacerbation where you have tightening of your airways, significant coughing, shortness of breath and sometimes even life-threatening airway edema.2. Who are the most vulnerable people?Walker: The most vulnerable groups are going to be young children, pregnant people as well as people with any kind chronic lung condition or heart condition, and the elderly, mostly because people that are older tend to have those underlying conditions. 3. Is it OK to workout outside (even for just a short amount of time)?Walker: That is dangerous. You dont know if youre going to be somebody whos out there for 20 minutes and ends up having an asthma exacerbation or a sudden airway problem.4. What could wildfire smoke mean for contracting COVID-19?Walker: COVID is setting up an inflammatory bomb in your body. And having underlying inflammation from being exposed to wildfire smoke could actually make it harder for your body to fight because of all the inflammation thats already there. This is all conjecture because we dont know. This is all early in COVID. This is all new to us. But just understanding basic physiology, it makes perfect sense that if youre already having inflammation, that COVID could come and significantly make it worse.5. Which masks should you wear to prevent COVID versus wildfire smoke?For COVID only: Cloth or surgical masksWalker: If youre going to be indoors, youre going to be around people, youre going to be going to the grocery store, I think wearing a cloth mask is perfectly fine or a regular surgical mask. Completely adequate.For COVID & wildfire smoke: K95 & N95 masksWalker: A K95, you can get these online. A lot of people are able to get them. These are good for trying to remove particles. The only problem is they dont get as good of a seal on your face, so theyre not quite as good as a regular N95 would be. But its still a viable option if youre going to be outside.N95 great for actually both COVID and wildfire smoke.For wildfire smoke only: N95 masks with a valveWalker: If youre going to be outdoors by yourself, youre not going to be around other people, youre just going to be maybe doing some yard work, this is the time to wear an N95 with a valve. Itll make it easier for you to breathe. Itll make it so that the air that youre breathing out can exhale beautifully. Just make sure that youre not around other people because that way youre not exposing them to COVID in the event that you do have it.6. How helpful are neck bandanas for COVID and smoke protection?Walker: Unfortunately, the neck bandanas are not terribly helpful. The material theyre made of is very stretchy and thin and so that material makes it very easy for particles to go through. One of the best ways to tell if your mask is too thin is to hold it up and blow out a candle. If you can blow out the candle, youre not protecting people from your droplets.

As Northern California sits under a thick blanket of wildfire smoke for days, many people are left wondering what the air quality means for their health.

It is really bad, said Dr. Vanessa Walker.

As a pulmonary physician with Sutter Health and Pulmonary Medicine Associates, Walker has treated COVID-19 patients throughout the pandemic.

Recently, she has seen an uptick in smoke-related hospital visits. To provide context, she said an AQI greater than 100 is unhealthy for sensitive groups. Right now, the AQI is well over 200.

So this is unhealthy for everybody no matter who you are. And unfortunately, it just seems to be getting worse especially as these wildfires are raging out of control, she said.

Here are six things to know about how smoke impacts your health according to Dr. Walker:

1. What are the negative impacts?

Walker: If you have no lung disease, youre probably just going to notice things like eye irritation, throat irritation, scratchy nose, watery eyes. But if you have any kind of underlying lung disease, COPD, emphysema, asthma, you can cause a serious reaction like an asthma exacerbation or a COPD exacerbation where you have tightening of your airways, significant coughing, shortness of breath and sometimes even life-threatening airway edema.

2. Who are the most vulnerable people?

Walker: The most vulnerable groups are going to be young children, pregnant people as well as people with any kind chronic lung condition or heart condition, and the elderly, mostly because people that are older tend to have those underlying conditions.

3. Is it OK to workout outside (even for just a short amount of time)?

Walker: That is dangerous. You dont know if youre going to be somebody whos out there for 20 minutes and ends up having an asthma exacerbation or a sudden airway problem.

4. What could wildfire smoke mean for contracting COVID-19?

Walker: COVID is setting up an inflammatory bomb in your body. And having underlying inflammation from being exposed to wildfire smoke could actually make it harder for your body to fight because of all the inflammation thats already there.

This is all conjecture because we dont know. This is all early in COVID. This is all new to us. But just understanding basic physiology, it makes perfect sense that if youre already having inflammation, that COVID could come and significantly make it worse.

5. Which masks should you wear to prevent COVID versus wildfire smoke?

For COVID only: Cloth or surgical masks

Walker: If youre going to be indoors, youre going to be around people, youre going to be going to the grocery store, I think wearing a cloth mask is perfectly fine or a regular surgical mask. Completely adequate.

For COVID & wildfire smoke: K95 & N95 masks

Walker: A K95, you can get these online. A lot of people are able to get them. These are good for trying to remove particles. The only problem is they dont get as good of a seal on your face, so theyre not quite as good as a regular N95 would be. But its still a viable option if youre going to be outside.

N95 [masks are] great for actually both COVID and wildfire smoke.

For wildfire smoke only: N95 masks with a valve

Walker: If youre going to be outdoors by yourself, youre not going to be around other people, youre just going to be maybe doing some yard work, this is the time to wear an N95 with a valve. Itll make it easier for you to breathe. Itll make it so that the air that youre breathing out can exhale beautifully. Just make sure that youre not around other people because that way youre not exposing them to COVID in the event that you do have it.

6. How helpful are neck bandanas for COVID and smoke protection?

Walker: Unfortunately, the neck bandanas are not terribly helpful. The material theyre made of is very stretchy and thin and so that material makes it very easy for particles to go through. One of the best ways to tell if your mask is too thin is to hold it up and blow out a candle. If you can blow out the candle, youre not protecting people from your droplets.

Read the rest here:
6 things to know about how wildfire smoke impacts your health - KCRA Sacramento

Physiology

The hepatocyte clock and feeding control chronophysiology of multiple liver cell types – Science Magazine

Keeping rhythm requires communication

In mammals, daily cycles in physiology require the synchronized activity of circadian clocks in peripheral organs such as the liver, a hub of metabolism. Guan et al. generated mice with hepatocytes that lack two transcriptional repressors known to be essential for clock function. This experimental manipulation unexpectedly disrupted rhythmic gene expression and metabolism not only in hepatocytes but also in other liver cell types. Feeding behavior also coregulated circadian rhythms in multiple liver cell types. Cell-cell communication thus appears to be important in maintaining the robustness of peripheral circadian clocks.

Science, this issue p. 1388

Most cells of the body contain molecular clocks, but the requirement of peripheral clocks for rhythmicity and their effects on physiology are not well understood. We show that deletion of core clock components REV-ERB and REV-ERB in adult mouse hepatocytes disrupts diurnal rhythms of a subset of liver genes and alters the diurnal rhythm of de novo lipogenesis. Liver function is also influenced by nonhepatocytic cells, and the loss of hepatocyte REV-ERBs remodels the rhythmic transcriptomes and metabolomes of multiple cell types within the liver. Finally, alteration of food availability demonstrates the hierarchy of the cell-intrinsic hepatocyte clock mechanism and the feeding environment. Together, these studies reveal previously unsuspected roles of the hepatocyte clock in the physiological coordination of nutritional signals and cell-cell communication controlling rhythmic metabolism.

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The hepatocyte clock and feeding control chronophysiology of multiple liver cell types - Science Magazine