Skip to main content

Home/ Dr. Goodyear/ Group items tagged reproductive

Rss Feed Group items tagged

Filter: All | Bookmarks | Topics Simple Middle
Nathan Goodyear

Association between Lead and Cadmium and Reproductive Hormones in Peripubertal U.S. Girls - 0 views

www.ncbi.nlm.nih.gov/...PMC3002200

heavy metals hormones girls puberty

shared by Nathan Goodyear on 20 Jul 14 - No Cached
  • Nathan Goodyear on 20 Jul 14
     
    Study finds higher Pb levels in young girls is associated with delayed puberty onset.  This occurs through an inverse relationship with inhibin B and follicular development.  This relationship was also found with Cadmium.  Both of these heavy metals are toxic to the ovaries.
Nathan Goodyear

Testosterone replacement: Medical alternative to bariatric surgery? : Clinica... - 0 views

www.clinicalendocrinologynews.com/...9ebe07503b9647c5b63b63de0.html

Testosterone low T low Testosterone men male hormones obese obesity

shared by Nathan Goodyear on 14 Oct 14 - No Cached
  • Nathan Goodyear on 14 Oct 14
     
    Testosterone therapy aids weight loss in study of obese men.  The presentation of the potentially biased study (study was funded by the makers of the Testosterone used in the study) proposes Testosterone as a pharmacologic bariatric treatment.  That conclusion is ludicrous!  Testosterone therapy has been shown to improve insulin sensitivity, improve glucose uptake, reduces inflammation, improve muscle building, and reduce the parameters of metabolic syndrome--all of which underlies the obesity.  Thus, men with low T and obesity, Testosterone therapy is playing a causal role in the obesity and thus Testosterone therapy is treating the cause.  But to describe it as pharmacologic bariatric therapy is false and misleading. http://ow.ly/CKrje 
Nathan Goodyear

PLOS ONE: The Gut Microbiota and Developmental Programming of the Testis in Mice - 0 views

journals.plos.org/...article

hormone hormones Testosterone gut flora gut microbiome gut microbiota

shared by Nathan Goodyear on 30 Apr 15 - No Cached
  • The intra-testicular level of testosterone in GF mice was found to be significantly lower than in SPF and CBUT mice
  • This study establishes a novel role for the commensal gut microbiota in the regulation of testicular development and function
  • Absence of the normal microbiota influences the formation and the integrity of the BTB as well as the intra-testicular levels of testosterone and serum levels of LH and FSH.
  • ...8 more annotations...
  • Nutritional, socioeconomic, lifestyle and environmental factors (among others) are involved in the regulation of normal spermatogenesis.
  • he gut microbiota is one such potential source of environmental factors/products that has developed an intimate symbiotic relationship with host's physiology.
  • Manipulation of the gut microbiotia through dietary modification, pre- and probiotics can therefore be beneficial for the host's reproductive health.
  • In the current study, colonizing GF mice with CBUT resulted in an increased sperm production, suggesting that bacterial products, e.g. of fermentation, directly or indirectly, can affect the testis.
  • the absence of gut microbiota influenced testosterone levels
  • A recent study demonstrated that dietary supplementation of the probiotics Lactobacillus reuteri increased and restored testosterone levels in aging mice
  • bacterial metabolites such as butyrate have been shown to increase the levels of LH [43] and FSH
  • This suggests that butyrate most likely regulates testosterone production at the testicular level by stimulation of gene expression in Leydig cells and with little or no effect at the pituitary- hypothalamic levels.
  • Nathan Goodyear on 30 Apr 15
     
    gut micro biome effects spermatogenesis, Testosterone production, and the brain-testicle-barrier.
Nathan Goodyear

The kisspeptin-GnRH pathway in human reproductive health and disease - 0 views

humupd.oxfordjournals.org/...humupd.dmu009.long

kisspeptin kisspeptins LH hormone hormones gonadotropins

shared by Nathan Goodyear on 16 Jun 15 - No Cached
  • Nathan Goodyear on 16 Jun 15
     
    good review of the current understanding of kisspeptin and gonadotropins.
Nathan Goodyear

Validation of Blood Spot Sampling for Gonadotropins and Ovarian Hormone Levels in Repro... - 0 views

www.fertstert.org/...fulltext

blood spot hormone testing hormones Estradiol Progesterone LH FSH

shared by Nathan Goodyear on 22 Jun 15 - No Cached
  • Nathan Goodyear on 22 Jun 15
     
    blood spot Estradiol, Progesterone, LH, and FSH levels shown to be comparable to plasma levels.
Nathan Goodyear

Sensitive salivary estradiol assay for monitoring ovarian function -- Worthman et al. 3... - 0 views

www.clinchem.org/...1769

salivary estradiol sensitive saliva testing

shared by Nathan Goodyear on 26 Jan 11 - No Cached
  • This assay may be particularly helpful in investigating ovarian function and free estradiol in women at various stages of the reproductive cycle.
  • Nathan Goodyear on 26 Jan 11
     
    salivary estradiol testing proves to be very helpful in evaluating ovaring function in women
Nathan Goodyear

Reproductive Health And The Industrialized Food System: A Point Of Intervention For Hea... - 0 views

content.healthaffairs.org/...888.abstract

health environmental toxins nutrition infertility obesity overweight

shared by Nathan Goodyear on 24 Aug 11 - No Cached
  • Nathan Goodyear on 24 Aug 11
     
    environmental toxins and poor nutrition are a major player in the rising infertility problems and obesity epidemic
Nathan Goodyear

Informa Healthcare - Systems Biology in Reproductive Medicine - 52(2):97 - Summary - 0 views

informahealthcare.com/...01485010500315479

Testosterone Estadiol Testosterone:Estradiol ratio HPA estrogen dominance low T aromatase obesity overweight

shared by Nathan Goodyear on 10 Oct 11 - No Cached
  • Nathan Goodyear on 10 Oct 11
     
    a decreasing Testosterone:Estradiol ratio leads to decreased sperm production.  This effectively occurs through the interaction of the elevated Estradiol and the HPA.
Nathan Goodyear

Parent bisphenol A accumulation in the human mater... [Environ Health Perspect. 2002] -... - 0 views

www.ncbi.nlm.nih.gov/...12417499

BPA endocrine disurptor

shared by Nathan Goodyear on 01 Jul 11 - No Cached
  • Exposure levels of parent BPA were found within a range typical of those used in recent animal studies and were shown to be toxic to reproductive organs of male and female offspring
  • BPA blood concentrations were higher in male than in female fetuses
  • Nathan Goodyear on 01 Jul 11
     
    Mother's exposure to toxic BPA passed to her child
Nathan Goodyear

Exposure to Bisphenol A Prenatally or in Adulthood Promotes TH2 Cytokine Production Ass... - 0 views

www.ncbi.nlm.nih.gov/...PMC2290985

BPA plastics endocrine disruptor immune T reg cells

shared by Nathan Goodyear on 01 Jul 11 - No Cached
  • BPA promotes the development of TH2 cells in adulthood and both TH1 and TH2 cells in prenatal stages by reducing the number of regulatory T cells.
  • Bisphenol A (BPA), an estrogenic endocrine-disrupting chemical (EDC
  • BPA is one of the most widespread EDCs.
  • ...12 more annotations...
  • BPA antagonizes the actions of thyroid hormone
  • Prenatal exposure to BPA has been shown to alter a variety of reproductive endocrine parameters, such as testosterone and luteinizing hormone levels
  • arly onset of sexual maturation of female mice
  • imbalanced T-helper (TH)1/TH2 immune responses have been demonstrated on exposure to BPA
  • indicating that BPA exerted its effects by reducing the number of Treg cells.
  • Exposure to BPA by subcutaneous injection in adulthood significantly promoted antigen-stimulated production of IL-4, IL-10, and IL-13 in TH2-skewed
  • BPA can leak from the placenta and accumulate in the fetus
  • We showed that prenatal exposure to BPA increased the production of a TH1 cytokine, IFN-γ, and a TH2 cytokine, IL-4, after the offspring developed, suggesting that prenatal exposure to BPA can induce persistent immunologic effects lasting into adulthood.
  • These results are consistent with a previous report that fetal exposure to BPA augmented TH1 and TH2 immune responses
  • our results clearly demonstrate that the production of TH2 cytokines is promoted by BPA in adult mice and in offspring during developmental exposure.
  • The decrease of Treg cells would predispose to immune dysfunction in aged individuals, explaining their higher risk of immune-mediated diseases, cancer, and infections.
  • BPA might cause these diseases. Thus, avoiding exposure to or promoting the excretion of BPA and other EDCs would help in preventing diseases and adverse health effects.
  • Nathan Goodyear on 01 Jul 11
     
    BPA as endocrine disruptor and as immune disruptor
Nathan Goodyear

Hypothalamic-Pituitary-Testicular Axis Disruptions in Older Men Are Differentially Link... - 0 views

press.endocrine.org/...jc.2007-1972

low T low Testosterone low T Testosterone aging LH hormone hormones men male SHBG

shared by Nathan Goodyear on 03 Sep 14 - No Cached
  • 0.4–2% annual decline
  • the age trend in free T was more substantial (−1.3% per annum)
  • The core hormonal pattern with increasing age is suggestive of incipient primary testicular dysfunction with maintained total T and progressively blunted free T associated with higher LH.
  • ...16 more annotations...
  • Obesity was associated with progressively lower total and free T independent of the simultaneous decrease in SHBG.
  • our data highlight the fact that LH was unchanged or even lower in older men in the face of lower T in obesity, suggesting that there may be a failure at the hypothalamic-pituitary level.
  • a change in BMI from nonobese to obese may be equivalent to a 15 yr fall in T.
  • This pattern supports the hypothesis that different underlying mechanisms influence the functions of the HPT axis: age predominantly affects testicular function, whereas obesity impairs hypothalamic/pituitary function.
  • the effects of aging on testicular function can be moderated by increased LH compensation for many decades
  • obesity impairs hypothalamic/pituitary function independent of age, arguably an adaptive response for which there should be no compensatory mechanism.
  • the concurrent but opposite (and separate) effects of obesity and age on SHBG
  • SHBG was negatively associated with increasing strata of obesity
  • Obesity is associated with insulin resistance (28), and the increased circulating insulin inhibits hepatic SHBG synthesis
  • the SHBG increase with age may be related to relative IGF-I deficiency (27), although this has not been directly proven.
  • Obesity is associated with peripheral and central insulin resistance (30) and proinflammatory cytokine production (TNFα and IL-6) from adipocytes (31) and central nervous system endocannibinoid release (32), all of which are potential candidates for abrogating hypothalamic endocrine and downstream reproductive axis functions.
    • Nathan Goodyear
      Nathan Goodyear on 03 Sep 14
       
      The HPA axis effect may be the result of inflammation.
  • The relationship between obesity and T can be bidirectional: low T may be the cause rather than consequence of obesity
  • chronic alcohol abuse is known to suppress LH (40), our data showed no significant association among the three hormones or SHBG and alcohol intake.
  • increase in total T in smokers occurs through a primary increase in SHBG with a compensatory rise in LH
  • the effects of obesity (BMI or waist circumference) was by far the most important determinant of variance in total T, whereas age per se was important for SHBG, LH, and free T with comorbidity and smoking being comparatively minor contributors
  • It is noteworthy that these predisposing lifestyle and health factors are modifiable. This implies that the apparent age-related decline in T may constitute a barometer of health and thus be potentially preventable and/or reversible.
  • Nathan Goodyear on 03 Sep 14
     
    Age induced decline in Testosterone is more associated with a decline in leydig cell function and thus elevated LH will be associated.  In contrast, obesity is more of a HPA axis disruption and thus LH may be normal to low.  The pulse amplitude is decrease.  No change in pulse frequency is noted.   With obesity, a decline in TT and fT was independent of SHBG. Aging is associated with a greater decrease in fT versus TT.
Nathan Goodyear

The kisspeptin-GnRH pathway in human reproductive health and disease - 0 views

humupd.oxfordjournals.org/...humupd.dmu009.full

kisspeptin kisspeptins hormones leptin hormone

shared by Nathan Goodyear on 04 Sep 14 - No Cached
  • Kisspeptin stimulates LH secretion in healthy men (filled squares) and women
  • This raises the possibility that diminished kisspeptin secretion is a potential mechanism for hypogonadotropic hypogonadism in patients with obesity and diabetes
  • The likely pathways for down-regulation of kisspeptin signalling include negative feedback by estrogen, which is markedly elevated in obesity (Schneider et al., 1979), resistance to leptin, also seen in human obesity (Finn et al., 1998), insulin resistance and hyperglycaemia (Castellano et al., 2006, 2009), and inflammation, which is up-regulated in hypogonadal men with diabetes (Dandona et al., 2008) and is associated with decreased kisspeptin expression in rats
  • Nathan Goodyear on 04 Sep 14
     
    Very nice, updated review of kisspeptins, hormone production and the negative/positive effects of kisspeptins.
Nathan Goodyear

Associations between Circulating Reproductive Hormones and SHBG and Prevalent and Incid... - 1 views

press.endocrine.org/...jc.2014-2464

metabolic syndrome metabolic syndrome men male hormone hormones health Testosterone DHT SHBG cFT free Testosterone

shared by Nathan Goodyear on 06 Oct 14 - No Cached
  • Nathan Goodyear on 06 Oct 14
     
    The best marker associated with MetS in older men was low SHBG. Low T, DHT, and cFT were found to be more biomarkers of poor health rather than causal.
Nathan Goodyear

Reproductive hormone increases in respo... [Med Sci Sports Exerc. 1986] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...2943968

exercise hormone hormones Testosterone men male

shared by Nathan Goodyear on 03 Aug 14 - No Cached
  • Nathan Goodyear on 03 Aug 14
     
    Exercise increased after just 20 minutes of exercise.  This study looked at serum Testosterone levels.
Nathan Goodyear

Hyperandrogenism sensitizes mononuclear cells to promote glucose-induced inflammation i... - 0 views

www.ncbi.nlm.nih.gov/...PMC3287360

inflammation glucose PCOS Testosterone DHEA women female hormone hormones

shared by Nathan Goodyear on 05 Aug 14 - No Cached
  • Nathan Goodyear on 05 Aug 14
     
    Interesting study finds hyperandrogenism stimulates excessive inflammatory response to glucose intake.  This study was done in otherwise healthy women not in women with PCOS.  The inflammatory cytokine production was via NF-KappaB activation.  Again, this has negative implications in women being doped with Testosterone.
Nathan Goodyear

Selenium and human health : The Lancet - 0 views

www.thelancet.com/...abstract

Selenium health

shared by Nathan Goodyear on 10 Nov 14 - No Cached
  • Low selenium status has been associated with increased risk of mortality, poor immune function, and cognitive decline
  • Higher selenium status or selenium supplementation has antiviral effects, is essential for successful male and female reproduction, and reduces the risk of autoimmune thyroid disease.
  • Prospective studies have generally shown some benefit of higher selenium status on the risk of prostate, lung, colorectal, and bladder cancers, but findings from trials have been mixed, which probably emphasises the fact that supplementation will confer benefit only if intake of a nutrient is inadequate
  • Nathan Goodyear on 10 Nov 14
     
    Selenium is a "U" shaped curve.  Abstract only available here.
Nathan Goodyear

Anticancer mechanisms of cannabinoids - 0 views

www.ncbi.nlm.nih.gov/...PMC4791144

THC cannabinoids cancer

shared by Nathan Goodyear on 18 Sep 18 - No Cached
  • modulating key cell signalling pathways involved in the control of cancer cell proliferation and survival
  • cannabinoids inhibit angiogenesis and decrease metastasis in various tumour types in laboratory animals
  • Cannabis sativa L. (marijuana)
  • ...41 more annotations...
  • of the approximately 108 cannabinoids produced by C. sativa, Δ9-tetrahydrocannabinol (thc) is the most relevant because of its high potency and abundance in plant preparations
  • Tetrahydrocannabinol exerts a wide variety of biologic effects by mimicking endogenous substances—the endocannabinoids anandamide3 and 2-arachidonoylglycerol4,5—that engage specific cell-surface cannabinoid receptors
  • the cb2 receptor was initially described to be present in the immune system6, but was more recently shown to also be expressed in cells from other origins
  • transient receptor potential cation channel subfamily V, member 1
  • orphan G protein–coupled receptor 55
  • Most of the effects produced by cannabinoids in the nervous system and in non-neural tissues rely on cb1 receptor activation
  • two major cannabinoid-specific receptors—cb1 and cb2
  • cardiovascular tone, energy metabolism, immunity, and reproduction
  • cannabinoids are well known to exert palliative effects in cancer patients
  • best-established use is the inhibition of chemotherapy-induced nausea and vomiting
  • thc and other cannabinoids exhibit antitumour effects in a wide array of animal models of cancer
  • cannabinoid receptors and their endogenous ligands are both generally upregulated in tumour tissue compared with non-tumour tissue
  • cb2 promotes her2 (human epidermal growth factor receptor 2) pro-oncogenic signalling in breast cancer
  • pharmacologic activation of cannabinoid receptors decreases tumour growth
  • endocannabinoid signalling can also have a tumour-suppressive role
  • pharmacologic stimulation of cb receptors is, in most cases, antitumourigenic. Nonetheless, a few reports have proposed a tumour-promoting effect of cannabinoids
  • most prevalent effect is the induction of cancer cell death by apoptosis and the inhibition of cancer cell proliferation
  • impair tumour angiogenesis and block invasion and metastasis
  • thc and other cannabinoids induce the apoptotic death of glioma cells by cb1- and cb2-dependent stimulation
  • Autophagy is primarily a cytoprotective mechanism, although its activation can also lead to cell death
  • autophagy is important for cannabinoid antineoplastic activity
  • autophagy is upstream of apoptosis in the mechanism of cannabinoid-induced cell death
  • the effect of cannabinoids in hormone- dependent tumours might rely, at least in part, on the ability to interfere with the activation of growth factor receptors
  • glioma cells), pharmacologic blockade of either cb1 or cb2 prevents cannabinoid-induced cell death with similar efficacy
  • other types of cancer cells (pancreatic48, breast24, or hepatic43 carcinoma cells, for example), antagonists of cb2 but not of cb1 inhibit cannabinoid antitumour actions
  • thc promotes cancer cell death in a cb1- or cb2-dependent manner (or both) at lower concentrations
  • cannabidiol (cbd), a phytocannabinoid with a low affinity for cannabinoid receptors15, and other marijuana-derived cannabinoids57 have also been proposed to promote the apoptotic death of cancer cells acting independently of the cb1 and cb2 receptors
  • In cancer cells, cannabinoids block the activation of the vascular endothelial growth factor (vegf) pathway, an inducer of angiogenesi
  • In vascular endothelial cells, cannabinoid receptor activation inhibits proliferation and migration, and induces apoptosis
  • cb1 or cb2 receptor agonists (or both) reduce the formation of distant tumour masses in animal models of both induced and spontaneous metastasis, and inhibit adhesion, migration, and invasiveness of glioma64, breast65,66, lung67,68, and cervical68 cancer cells in culture
  • the ceramide/p8–regulated pathway plays a general role in the antitumour activity of cannabinoids targeting cb1 and cb2
  • cbd, by acting independently of the cb1 and cb2 receptors, produces a remarkable anti-tumour effect—including reduction of invasiveness and metastasis
  • cannabinoids can also enhance immune system–mediated tumour surveillance in some contexts
  • ability of thc to reduce inflammation75,76, an effect that might prevent certain types of cancer
  • recent observations suggest that the combined administration of cannabinoids with other anticancer drugs acts synergistically to reduce tumour growth
  • combined administration of gemcitabine (the benchmark agent for the treatment of pancreatic cancer) and various cannabinoid agonists synergistically reduced the viability of pancreatic cancer cells
  • Other reports indicated that anandamide and HU-210 might also enhance the anticancer activity of paclitaxel89 and 5-fluorouracil90 respectively
  • Combined administration of thc and cbd enhances the anticancer activity of thc and reduces the dose of thc needed to induce its tumour growth-inhibiting activity
  • Preclinical animal models have yielded data indicating that systemic (oral or intraperitoneal) administration of cannabinoids effectively decreases tumour growth
  • Combinations of cannabinoids with classical chemotherapeutic drugs such as the alkylating agent temozolomide (the benchmark agent for the management of glioblastoma80,84) have been shown to produce a strong anticancer action in animal models
  • pharmacologic inhibition of egfr, erk83, or akt enhances the cell-death-promoting action of thc in glioma cultures (unpublished observations by the authors), which suggests that targeting egfr and the akt and erk pathways could enhance the antitumour effect of cannabinoids
  • Nathan Goodyear on 18 Sep 18
     
    Good review of the anticancer effects of cananbinoids.
Nathan Goodyear

Influence of Endogenous Reproductive Hormones on F2-Isoprostane Levels in Premenopausal... - 0 views

www.ncbi.nlm.nih.gov/...PMC2950793

F2 Isoprostane estrogen estradiol hormones oxidative stress cardiovascular disease

shared by Nathan Goodyear on 16 Jul 17 - No Cached
  • Nathan Goodyear on 16 Jul 17
     
    Endogenous estradiol levels correlate with F2 Isoprostane levels in premenopausal women.
Nathan Goodyear

Sex hormones affect neurotransmitters and shape the adult female brain during hormonal ... - 0 views

www.ncbi.nlm.nih.gov/...PMC4335177

hormones neurotransmitters serotonin GABA dopamine estradiol progesterone glutamate

shared by Nathan Goodyear on 11 Jul 17 - No Cached
  • estrogen administration has been found to increase tryptophan hydroxylase
  • 5-HT2A mRNA levels in brain areas relevant for the control of mood, mental state and cognition (Sumner and Fink, 1998) and 5-HTT mRNA when administered for a longer period
  • n the other hand, estrogen treatment has also been observed to decrease mRNA related to serotonergic neurotransmission
  • ...4 more annotations...
  • Furthermore, acute estrogen administration decreases 5-HTT mRNA levels (Pecins-Thompson et al., 1998) and 5-HT1A mRNA levels and binding
  • assigning the effects of estrogen on serotonin to a homogenous functional class of stimulation or inhibition seems not to be feasible
  • Progesterone has been suggested to increase serotonergic neurotransmission via the regulation of the expression of serotonin-related genes and proteins
  • menopausal women gain less benefit from antidepressant treatments compared to women during their reproductive years
  • Nathan Goodyear on 11 Jul 17
     
    good review of the relationship of the sex hormones and neurotransmitters.
Nathan Goodyear

Sex hormones and the immune response in humans | Human Reproduction Update | Oxford Aca... - 0 views

academic.oup.com/...874969

NK cells hormones natural killer cells Testosterone estradiol

shared by Nathan Goodyear on 13 Sep 19 - No Cached
  • Nathan Goodyear on 13 Sep 19
     
    To be read
« First ‹ Previous 41 - 60 of 67 Next ›
Showing 20▼ items per page