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Nathan Goodyear

PLOS ONE: Microbial Dysbiosis in Colorectal Cancer (CRC) Patients - 0 views

  • differences in the colon microbiota in individuals with colon cancer versus those with a normal colonoscopy
  • qPCR revealed significant elevation of the Bacteroides/Prevotella population in cancer patients that appeared to be linked with elevated IL17 producing cells in the mucosa of individuals with cancer.
  • Bacteroides genus populations and more specifically those of Bacteroides fragilis, have recently been shown to produce a metalloprotease in colon cancer patients, but not in controls [12] suggesting this species sub population might favor carcinogenesis
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  • It is noteworthy that among the many mechanisms that may mediate associations between microbiota and human health [21]–[22], pro-inflammatory and immune cell activation in colon mucosa are of great importance in relation to malignancy
  • B. fragilis has been shown to induce mucosal regulatory T-cell responses in the intestine involving TH17 cell recruitment in experimental models
  • the elevations of Bacteroides in the stool and/or IL17 immunoreactive cells in the normal mucosa appear to be promising sensitive markers
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    A relationship between dysbiosis and colon cancer appears to be present.  Particularly an increase in Bacteroidetes and Prevotella species were found in those with colon cancer versus those without.  An inflammatory up regulation of IL-17 appears to be involved.  Whether this is a cause or effect is yet to be determined, but the presence of elevated Bacteroidetes species with increased IL17 could be used as sensitive biomarkers.
Nathan Goodyear

T Cells Promote Metastasis by Regulating Extracellular Matrix Remodeling following Chemotherapy | Cancer Research | American Association for Cancer Research - 0 views

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    "…chemotherapy-induced, host-mediated mechanism that promotes remodeling of the extracellular matrix (ECM), ultimately facilitating cancer cell seeding and metastasis."
Nathan Goodyear

TGF-β1 secreted by M2 phenotype macrophages enhances the stemness and migration of glioma cells via the SMAD2/3 signalling pathway - 0 views

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    T-regulator cells secrete TGF-beta to promote M2 polarization in the TME to promote tumor progression and spread.
Nathan Goodyear

Lowered testosterone in male obesity: Mechanisms, morbidity and management Tang Fui MN, Dupuis P, Grossmann M - Asian J Androl - 0 views

  • The number of overweight people is expected to increase from 937 million in 2005 to 1.35 billion in 2030
  • Similarly the number of obese people is projected to increase from 396 million in 2005 to 573 million in 2030
  • By 2030, China alone is predicted to have more overweight men and women than the traditional market economies combined
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  • diacylglycerol O-acyltransferase 2 (DGAT2), mechanistically implicated in this differential storage, [10] is regulated by dihydrotestosterone, [11] suggesting a potential role for androgens to influence the genetic predisposition to either the MHO or MONW phenotype.
  • bariatric surgery achieves 10%-30% long-term weight loss in controlled studies
  • The fact that obese men have lower testosterone compared to lean men has been recognized for more than 30 years
  • Reductions in testosterone levels correlate with the severity of obesity and men
  • epidemiological data suggest that the single most powerful predictor of low testosterone is obesity, and that obesity is a major contributor of the age-associated decline in testosterone levels.
  • healthy ageing by itself is uncommonly associated with marked reductions in testosterone levels
  • obesity blunts this LH rise, obesity leads to hypothalamic-pituitary suppression irrespective of age which cannot be compensated for by physiological mechanisms
  • Reductions in total testosterone levels are largely a consequence of reductions in sex hormone binding globulin (SHBG) due to obesity-associated hyperinsulinemia
  • although controversial, measurement of free testosterone levels may provide a more accurate assessment of androgen status than the (usually preferred) measurement of total testosterone in situations where SHBG levels are outside the reference range
  • SHBG increases with age
  • marked obesity however is associated with an unequivocal reduction of free testosterone levels, where LH and follicle stimulating hormone (FSH) levels are usually low or inappropriately normal, suggesting that the dominant suppression occurs at the hypothalamic-pituitary level
  • adipose tissue, especially when in the inflamed, insulin-resistant state, expresses aromatase which converts testosterone to estradiol (E 2 ). Adipose E 2 in turn may feedback negatively to decrease pituitary gonadotropin secretion
  • diabetic obesity is associated with decreases in circulatory E 2
  • In addition to E 2 , increased visceral fat also releases increased amounts of pro-inflammatory cytokines, insulin and leptin; all of which may inhibit the activity of the HPT axis at multiple levels
  • In the prospective Massachusetts Male Aging Study (MMAS), moving from a non-obese to an obese state resulted in a decline of testosterone levels
  • weight loss, whether by diet or surgery, increases testosterone levels proportional to the amount of weight lost
  • fat is androgen-responsive
  • low testosterone may augment the effects of a hypercaloric diet
  • In human male ex vivo adipose tissue, testosterone decreased adipocyte differentiation by 50%.
  • Testosterone enhances catecholamine-induced lipolysis in vitro and reduces lipoprotein lipase activity and triglyceride uptake in human abdominal adipose tissue in vivo
  • in men with prostate cancer receiving 12 months of androgen deprivation therapy, fat mass increased by 3.4 kg and abdominal VAT by 22%, with the majority of these changes established within 6 months
  • severe sex steroid deficiency can increase fat mass rapidly
  • bidirectional relationship between testosterone and obesity
  • increasing body fat suppresses the HPT axis by multiple mechanisms [30] via increased secretion of pro-inflammatory cytokines, insulin resistance and diabetes; [19],[44] while on the other hand low testosterone promotes further accumulation of total and visceral fat mass, thereby exacerbating the gonadotropin inhibition
  • androgens may play a more significant role in VAT than SAT
  • men undergoing androgen depletion for prostate cancer show more marked increases in visceral compared to subcutaneous fat following treatment
    • Nathan Goodyear
       
      Interesting: low T increases VAT, yet T therapy does not reduce VAT, yet T therapy reduces SAT.
  • irisin, derived from muscle, induces brown fat-like properties in rodent white fat
  • androgens can act via the PPARg-pathway [37] which is implicated in the differentiation of precursor fat cells to the energy-consuming phenotype
  • low testosterone may compound the effect of increasing fat mass by making it more difficult for obese men to lose weight via exercise
  • pro-inflammatory cytokines released by adipose tissue may contribute to loss of muscle mass and function, leading to inactivity and further weight gain in a vicious cycle
  • Sarcopenic obesity, a phenotype recapitulated in men receiving ADT for prostate cancer, [55] may not only be associated with functional limitations, but also aggravate the metabolic risks of obesity;
  • observational evidence associating higher endogenous testosterone with reduced loss of muscle mass and crude measures of muscle function in men losing weight
  • genuine reactivation of the HPT axis in obese men requires more substantial weight-loss
  • A number of intervention studies have confirmed that both diet- and surgically-induced weight losses are associated with increased testosterone, with the rise in testosterone generally proportional to the amount of weight lost
  • men, regardless of obesity level, can benefit from the effect of weight loss.
  • inconsistent effect of testosterone on VAT
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    to be read
Nathan Goodyear

Development of PD-1/PD-L1 Pathway in Tumor Immune Microenvironment and Treatment for Non-Small Cell Lung Cancer | Scientific Reports - 0 views

  • the lack of immunologic control is recognized as a hallmark of cancer currently
  • Programmed death-1 (PD-1) and its ligand PD-L1 play a key role in tumor immune escape and the formation of tumor microenvironment, closely related with tumor generation and development
  • Blockading the PD-1/PD-L1 pathway could reverse the tumor microenvironment and enhance the endogenous antitumor immune responses.
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  • environmental factors, living habits, genetic mutations, dysfunction of the immune system and so on
  • special tumor immune microenvironment
  • cytotoxic T lymphocyte-associated antigen 4 (CLTA-4), Programmed death-1 (PD-1) and its ligands PD-L1 (B7H1) and PD-L2 (B7-DC)
  • CTLA-4 regulates T cell activity in the early stage predominantly, and PD-1 mainly limits the activity of T-cell in the tumor microenvironment at later stage of tumor growth
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    PD-1 to read.
Nathan Goodyear

Vitamin D-mediated immune regulation in multipl... [J Neurol Sci. 2011] - PubMed - NCBI - 0 views

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    Vitamin D's immunomodulating role is an important tool in those with MS. Particularily, it increases T reg cells.
Nathan Goodyear

The telomerase activator TA-65 elongates short telomeres and increases health span of adult/old mice without increasing cancer incidence - 0 views

  • studies have demonstrated that the shortest telomeres are causal of reduced cell viability
  • a stable and enforced expression of telomerase leads to an improved health-span, accompanied by an extension of lifespan
  • TA-65 influences the percentage of cellular short telomeres through the activation of telomerase
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  • TA-65 administration during 4 months significantly improved the capacity to uptake glucose after a glucose pulse
  • liver protective action of TA-65
  • A disadvantage of mTERT potentiation could be associated to its capacity to favor proliferation of cancerous cells in murine models
  • TA-65 treated mice presented a similar incidence of malignant cancers at time of death, with a tendency to show decreased sarcomas and slightly increased lymphomas
  • We demonstrate here that TA-65 leads to a significant rescue of short telomeres through telomerase activation
  • TA-65 treatment increases proliferation and mobilization potential of mouse keratinocytes in vitro, a situation mimicking telomerase overexpression
  • TAT2, a similar molecule, have beneficial effects in the activation of CD8+ T lymphocytes from HIV-infected patients where they observe an increase of the proliferative potential and enhancement of cytokine/chemokine production
  • TA-65 resulted in a similar rescue of short telomeres in leukocytes post-treatment as observed with humans, most likely through an activation of telomerase
  • we observe that TA-65 lead to 10 fold increase of telomerase RNA levels in the liver of treated mice comparing to the non-treated same-age cohorts
  • TA-65 regulates telomerase at the transcription level, probably through the regulation of the MAPK pathway
  • TA-65 dependent telomerase activation results in a better organ fitness as demonstrated by the improved scores at the glucose tolerance test and insulin levels at fasting
  • TA-65 supplemented mice also present modest enhancement of the subcutaneous and epidermal thickness, as well as higher bone density, representative of an overall fitness status improvemen
  • TA-65 treated mice present higher levels of RBC and hemoglobin comparing to the control cohorts
  • improved health-span of TA-65 treated mice is not accompanied by increased cancer incidence, which may be related to the fact that TERT levels are very modestly increased in all tissues tested except for the liver
  • systemic telomerase overexpression from the germline leads to protection from aging associated pathologies
  • similar situation could be mimicked expressing telomerase late in life in a telomerase deficient background
  • we observed a higher proliferation rate and a partial protection from cell death in some tissues of TA65 treated mice
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    TA-65 shown to increase telomerase activity, and thus telomere length of short telomeres, in mouse study.  
Nathan Goodyear

Pregnancy-Specific Down-Regulation of NF-κB Expression in T Cells in Humans Is Essential for the Maintenance of the Cytokine Profile Required for Pregnancy Success - 0 views

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    this article discusses how progesterone protects the developing pregnancy.  Progesterone down regulates NF-kappaB and thus downregulates Th1 activity.
Nathan Goodyear

Telomere shortening and ageing of the immune system | Mendeley - 0 views

  • The immune system is highly sensitive to shortening of telomeres
  • they can up-regulate telomerase, the telomere extending enzyme
  • In ageing immune system adaptive immunity deteriorates because of a progressive decline of naive T and B cells and decrease of absolute numbers of T and B lymphocytes
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    the immune system is very sensitive to shortening of telomere length. This change in the immune system can be a pivotal role in disease development
Nathan Goodyear

Redefining Metabolic Syndrome in Men (July 2012) Townsend Letter for Doctors & Patients - 0 views

  • Approximately 95% to 98% of testosterone is bound to a carrier protein at any given time, leaving just the remaining 2% to 5% as completely unbound and available for tissues to use
  • most serum laboratories offer a free testosterone level, which is a calculated value based on SHBG levels or determined with equilibrium dialysis
  • the hormone enters the salivary gland by passive diffusion
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  • Testosterone has a known age-related decline, and total levels typically drop by approximately 1.6% per year beginning for most men in their 30s
  • As estrogen levels rise, they prompt the body to produce more SHBG, which in turn has a higher binding affinity for testosterone, and drives the unbound fraction of the testosterone pool down even further
  • When the increase in SHBG is taken into account, the age-related decline in the level of hormone that can be used by the body is closer to 2% to 3% per year.
  • Stinging nettle (Urtica dioica), an herb commonly used for allergies, can also be employed to bind to SHBG, which leaves more testosterone available to tissues
  • Leptin, an adipose-derived peptide hormone that regulates appetite and metabolism, has been shown to directly inhibit testosterone production in animal models
  • tumor necrosis factor alpha (TNF-alpha) and interleukin-1 (IL-1) further inhibit Leydig cell testosterone production
  • Natural aromatase inhibitors include the bioflavonoids chrysin and luteolin
  • Zinc deficiency causes an upregulation of the aromatase enzyme
  • Testosterone reduces lipoprotein lipase (LPL) activity
  • there are several herbs that can work to boost testosterone levels, including longjack (Eurycoma longifolia), horny goat weed (Epimedium grandiflorum), and tribulus (Tribulus terrestris).
  • the majority of the hormone is bound to carrier proteins including sex hormone binding globulin (SHBG) and albumin
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    nice and short review on testosterone and men's  health.
Nathan Goodyear

Transdermal testosterone replacement therapy in men - 0 views

  • a recent study has suggested that it may sometimes be inaccurate because of abnormal fluctuation of other circulating androgens
    • Nathan Goodyear
       
      The authors are referencing the increase in the suggestions to use other testing techniques i.e. saliva.
  • Testosterone therapy can inhibit hepcidin transcription and is associated with increased iron incorporation into red blood cells and increased erythropoietin concentrations
  • Transdermal TRT has a more favorable adverse effect profile when compared to buccal testosterone formulations
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  • testosterone concentrations should be checked 2–3 months after initiation of therapy and after adjusting the dose
  • the recommendation for injectable testosterone esters is to check the serum concentration midway between injections
  • it is recommended for serum testosterone to be evaluated 3 to 12 hours after application of the transdermal patch
  • Approximately 0.3% of testosterone is converted into estradiol by aromatase (CYP19A1)
  • a study from 1989 utilizing testosterone transdermally containing 5, 10, or 15 mg of testosterone showed that peak concentrations of testosterone were achieved 3 to 8 hours after scrotal application in hypogonadal men
  • measure serum testosterone any time after the patient has been on treatment with gel for at least 1 week
  • evaluate serum testosterone at the end of the dosing interval for testosterone pellets
  • increased amount of fat leads to increased extragonadal aromatase activity, resulting in increased concentrations of estradiol. High circulating concentrations of estradiol down regulate the HPG axis and decrease the amount of circulating testosterone
  • Up to 80% of plasma estradiol originates from aromatization of testosterone and less than 20% of estradiol in the circulation is secreted by the testes
  • A PSA concentration, digital rectal examination, and hematocrit should be performed at baseline and at 3 months, 6 months, then yearly after TRT is initiated.
  • It is used for many medications and has the advantage of high bioavailability, absence of hepatic first pass metabolism, increased therapeutic efficacy, and steadiness of plasma concentrations of the drug
  • If the hematocrit rises above 54%, treatment should be discontinued
  • elderly men having higher estradiol serum concentrations than postmenopausal women
Nathan Goodyear

Non-genomic Actions of Thyroid Hormones Regulate the Growth and Angiogenesis of T Cell Lymphomas - 0 views

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    Non-genomic signaling of thyroid hormone signals angiogenesis.
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