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Nathan Goodyear

Circulating 2-hydroxy and 16-α hydroxy estrone levels and risk of breast canc... - 1 views

www.ncbi.nlm.nih.gov/...PMC2562592

estrogen metabolism menopause post-menopause post menopause estrogen metabolite 2-OH-estrone 16-alpha-OH-estrone 2:16alpha-OH estrone breast cancer risk hormone hormones

shared by Nathan Goodyear on 21 Aug 14 - No Cached
  • 2-OH estrogens bind to the estrogen receptor (ER) with affinity equivalent to or greater than estradiol
  • previous prospective studies have not observed any significant associations with either 2-OH or 16α-OH estrone or the ratio of the two metabolites and breast cancer risk overall.
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      whether that risk is increased or decreased
  • it has been hypothesized that metabolism favoring the 2-OH over the 16α-OH pathway may be inversely associated with breast cancer risk (28).
  • ...24 more annotations...
  • they may act as only weak mitogens (14, 15), or as inhibitors of proliferation
  • No significant associations have been observed between 2-OH estrone and breast cancer risk
  • While 16α-OH estrone binds to the ER with lower affinity than estradiol, it binds covalently (18-20) and once bound, fails to down-regulate the receptor (21). Thus, 16α-OH estrone stimulates cell proliferation in a manner comparable to estradiol in ER+ breast cancer cell lines
  • In this large prospective study of 2-OH and 16α-OH estrone metabolites and breast cancer risk, we did not observe any significant associations overall with either individual metabolite or with the ratio of the two metabolites
  • we observed positive associations with 2-OH estrone and the 2:16α-OH estrone ratio among women with lower BMI and women with ER-/PR-tumors,
  • To date, several epidemiologic studies have examined the association between the 2-OH and 16α-OH estrogen metabolites and breast cancer risk with inconclusive results.
  • circulating estrogen levels have been associated more strongly with ER+/PR+ tumors than with ER-/PR- tumors
  • our results do not support the hypothesis that metabolism favoring the 2-OH estrone pathway is more beneficial to breast cancer risk than that favoring the 16α-OH estrone pathway
  • we observed significant positive associations of both 2-OH estrone and the 2:16α-OH estrone ratio with ER-/PR-tumors
  • Three (30, 32, 33) of four (30-33) studies observed RRs above 1 for the association between 16α-OH estrone and breast cancer risk (range of RRs=1.23-2.47); none of the point estimates was statistically significant though one trend was suggestive
  • based on animal studies, 2-OH estrone and the 2:16α-OH estrone ratio have been hypothesized to be inversely associated with breast cancer risk
  • No significant associations have been observed between 2-OH estrone, 16α-OH estrone, or the 2:16α-OH estrone ratio and breast cancer risk and the direction of the estimates is not consistent across studies.
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      better worded is no consistent, significant associations.   There are some studies that point to the 16 catecholestrogen and increased cancer risk; limited studies show negative effects of 2 catecholestrogens on cancer risk and prospective studies available pretty much dispel the idea that the 2:16 ratio has an risk predictability.
  • we observed a suggestive inverse association with 16α-OH estrone and a significant positive association with the 2:16α-OH estrone ratio among lean women, suggesting possible associations in a low estrogen environment.
  • 16α-OH estrone increases unscheduled DNA synthesis in mouse mammary cells (27) and hence also may be genotoxic
  • Although 2-OH estrogens are capable of redox cycling, the semiquinones and quinones (i.e., the oxidized forms) form stable DNA adducts that are reversible without DNA destruction
  • In our population of PMH nonusers, we observed no associations with ER+/PR+ tumors, but significant positive associations with 2-OH estrone and the 2:16α-OH estrone ratio among women with ER-/PR- tumors
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      one of the few studies to find this association between 2 catecholestrogens and the 2:16 ratio and ER-/PR-tumors
  • Animal and in vitro studies have shown that hydroxy estrogens can induce DNA damage either directly, through the formation of quinones and DNA adducts, or indirectly, through redox cycling and the generation of reactive oxygen species
    • Nathan Goodyear
      Nathan Goodyear on 08 Oct 15
       
      genotoxic via directe DNA adducts and indirectly via ROS; this is in addition to the proliferative effect
  • we observed a significant positive association between the 2:16α-OH estrone ratio and breast cancer risk among lean women
  • No significant associations have been observed with the 2:16α-OH estrone ratio
  • In the Danish study, no associations were observed with either ER+ or ER- tumors among PMH nonusers
  • significant positive associations with 2-OH estrone and the 2:16α-OH estrone ratio were observed among PMH users with ER+, but not ER-, tumors
  • it is possible that the genotoxicity of 2-OH estrone plays a role in hormone receptor negative tumors
  • 4-OH estrogens have a greater estrogenic potential than 2-OH estrogens, given the lower dissociation rate from estrogen receptors compared with estradiol (61), and are potentially more genotoxic since the quinones form unstable adducts, leading to depurination and mutation in vitro and in vivo
  • the balance between the catechol (i.e., 2-OH and 4-OH) and methoxy (i.e., 2-Me and 4-Me) estrogens may impact risk
  • Nathan Goodyear on 21 Aug 14
     
    The risks of estrogen metabolism are not clear cut.  Likely never will be due to the complexity of individual metabolism.  This study found no correlation between 2OH-Estrone and 2OH:16alpha-Estrone and breast cancer risk in ER+/PR+ breast cancer.  Translated: no benefit in breast cancer risk in 2OH-Estrone metabolism or increased 2OH:16alpha estrone metabolism.  There was a positive association between 2OH-Estrone and 2:16alpha-Estrone in women with ER-/PR- tumors and low BMI.
  • anonymous on 28 Oct 15
     
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Nathan Goodyear

Inborn-like errors of metabolism are determinants of breast cancer risk, clinical respo... - 0 views

www.ncbi.nlm.nih.gov/...PMC6114970

cancer metabolism breast cancer glutamine glutamate aspartate oncogenes

shared by Nathan Goodyear on 24 Sep 18 - No Cached
  • We now recognize that human cancers evolve in an environment of metabolic stress. Rapidly proliferating tumor cells deprived of adequate oxygen, nutrients, hormones and growth factors up-regulate pathways that address these deficiencies to overcome hypoxia (HIF), vascular insufficiency (VEGF), growth factor deprivation (EGFR, HER2) and the loss of hormonal support (ER, PR, AR) all to enhance survival and proliferation
  • RAS, PI3K, TP53 and MYC
  • The results suggest that breast cancer could be preceded by systemic subclinical disturbances in glucose-insulin homeostasis characterized by mild, likely asymptomatic, IEM-like biochemical changes
  • ...16 more annotations...
  • The process would include variable periods of hyperinsulinemia with the consequent systemic MYC activation of glycolysis, glutaminolysis, structural lipidogenesis and further exacerbation of hypoglycemia, the result of MYC's known role as an inhibitor of liver gluconeogenesis
  • The metabolic changes we describe in breast cancer arise in concert with IEM-like changes in oxidative phosphorylation as detected by increased values of the ratio lactate/pyruvate (Supplementary Table 2A, 2B) characteristic of Ox/Phos deficiency [25]. In our study, 76% (70/92) of the European breast cancer patients had lactate/pyruvate ratios values higher than the normal value of 25.8
  • four-fold higher frequency of cancer (including breast) in patients with energy metabolism disorders
  • growing recognition that cancer cells differ from their normal counterparts in their use of nutrients, synthesis of biomolecules and generation of energy
  • glutamine concentrations in the cancer patients were reduced to nearly 1/8 of the levels observed in the normal population
  • blood concentrations of aspartate (p = 1.7e-67, FDR = 8.3e-67) (Figure ​(Figure1E)1E) and glutamate (p = 6.4e-96, FDR = 6.2e-95) (Figure ​(Figure1F)1F) were nearly 10 fold higher than the normal ranges of 0–5 μM/L and 40 μM/L, respectively
  • glutamine consumption associated with parallel increases in glutamate and aspartate (Figure ​(Figure1A1A red arrows) is considered a hallmark of MYC-driven “glutaminolysis”
  • Gln/Glu ratio inversely correlates with i- late stage metabolic syndrome and with ii- increased chance of death
  • changes in glutamine consumption, reflected by the Gln/Glu ratio could provide a metabolic link between breast cancer initiation and diabetes, reflective of a systemic metabolic reprogramming from glucose to glutamine as the preferred source of precursors for biosynthetic reactions and cellular energy
  • lower Gln/Glu ratios inversely correlated with insulin resistance and the risk of diabetes
  • the metabolic dependencies of cancer characterized by excessive glycolysis, glutaminolysis and malignant lipidogenesis, previously considered a consequence of local tumor DNA aberration [23] could, instead, represent a systemic biochemical aberration that predates and very likely promotes tumorigenesis
  • these metabolic disturbances would be expected to remain extant after therapeutic interventions
  • accumulation of very long chain acylcarnitines such as C14:1-OH (p = 0.0, FDR = 0.0), C16 (p = 0.0, FDR = 0.0), C18 (p = 0.0, FDR = 0.0) and C18:1 (p = 1.73e-322, FDR = 1.16-321) and lipids containing VLCFA (lysoPC a C28:0) (p = 1.14-e95, FDR = 1.65e-95) in the blood of breast and colon cancer patients
  • Among the most powerful metabolic equations for MYC-activation is that which links the widely used MYC-driven desaturation marker ratio of SFA/MUFA to the MYC glutaminolysis-associated ratio of (Asp/Gln)
  • liver dysfunction shares many features with both IEM and cancer suggesting a role for hepatic dysfunction in carcinogenesis
  • cancer “conscripts” the human genome to meet its needs under conditions of systemic metabolic stress
  • Nathan Goodyear on 24 Sep 18
     
    Breast cancer is a metabolic disease.  Now, where have I heard that cancer is a metabolic disease?
Nathan Goodyear

Branched-chain amino acids in liver diseases - 0 views

www.ncbi.nlm.nih.gov/...PMC3837260

BCAA branched chain amino acids liver cirrhosis disease

shared by Nathan Goodyear on 05 Oct 15 - No Cached
  • Serum concentrations of BCAAs are decreased, while the concentrations of the aromatic amino acids (AAAs) phenylalanine and tyrosine are increased, in patients with advanced liver diseases, resulting in a low ratio of BCAAs to AAAs, a ratio called the Fischer ratio
  • BCAAs were reported to stimulate the production of hepatocyte growth factor
  • a simplified Fischer ratio, the BCAA to tyrosine ratio (BTR), has been reported useful for predicting serum albumin concentration one year later
  • ...10 more annotations...
  • BCAA supplementation was shown to delay the progression of CCl4-induced chronic liver injury in a rat model by reducing hepatic apoptosis
  • BCAAs promoted hepatocyte regeneration in a rat model of hepatectomy
  • BCAA supplementation for advanced cirrhotic patients improves nutritional status and quality of life
  • BCAAs activate mTOR and subsequently increase the production of eukaryotic initiation factor 4E-binding protein-1 and ribosomal protein S6 kinase, which upregulate the synthesis of albumin
  • BCAAs were shown to improve homeostasis model assessment scores for insulin resistance (HOMA-IR) and beta cell function (HOMA-%B) in patients with chronic liver disease, indicating that BCAAs can ameliorate insulin resistance
  • Several clinical trials have suggested that BCAA supplementation improves the prognosis of cirrhotic patients
  • A low Fischer ratio has been associated with hepatic encephalopathy
  • Treatment with BCAAs may therefore have a beneficial effect on patients with hepatic encephalopathy mainly by compensating decreased ratio of BCAAs to AAAs, but not by reducing serum ammonia levels
  • Two randomized studies also showed that BCAAs did not clearly prevent HE in patients with advanced cirrhosis, although BCAAs prevented the progression of hepatic failure
  • a systematic review with meta-analyses on the effect of oral BCAAs for the treatment of HE was published[66]. The review has revealed that supplementation of oral BCAAs in cirrhotic patients inhibits the manifestation of HE, especially in patients with overt HE rather than those with minimal HE, but showed no effect on the survival of those patients[66]. Thus, oral administration of BCAAs is the treatment of choice in cirrhotic patients with HE
  • Nathan Goodyear on 05 Oct 15
     
    good review of BCAA and liver disease: both mechanisms and therapy.
Nathan Goodyear

Thieme E-Journals - International Journal of Sports Medicine / Abstract - 0 views

www.thieme-connect.com/...s-2007-971102

competition sports exercise T:C testosterone cortisol recovery athlete athletics

shared by Nathan Goodyear on 19 Feb 13 - No Cached
  • Nathan Goodyear on 19 Feb 13
     
    competition versus recovery period in wrestling reveals different salivary hormone ratios. Competition results in low Testosterone to cortisol ratio versus the recovery phase which was found to be associated with a high testosterone to cortisol ratio.
Nathan Goodyear

Waist-to-height ratio as a predictor of serum testosterone in ageing men with symptoms ... - 0 views

www.ncbi.nlm.nih.gov/...PMC3739344

waist to height ratio low T low testosterone aging Testosterone male hormones hormones men

shared by Nathan Goodyear on 19 Sep 16 - No Cached
  • WHt ratio was calculated by dividing waist (cm) by height (cm)
  • nverse relationships of BMI and WC with TT and cFT have been previously documented in unselected cohorts of adult men
  • over the age of 54 years
  • ...5 more annotations...
  • adjusting WC for height (WHt ratio) improves the prediction of TT and cFT compared with either BMI or WC alone
  • there were inverse correlations between cFT, TT and either BMI or WC
  • for each unit increase in BMI, there was a 2% fall in TT and cFT
  • for each 10 cm increment in WC, TT and cFT levels declined by 7%.
  • The magnitude of this relationship between increasing BMI and decreasing TT is similar to that described in the Massachusetts Male Ageing Study
  • Nathan Goodyear on 19 Sep 16
     
    waist to height ratio reliable predictor of low T in men.
Nathan Goodyear

Saliva cortisol, testosterone and T/C ratio... [Int J Sports Med. 1999] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...10190771

saliva salivary Testosterone athletes cortisol catabolic sports recovery T:C ratio

shared by Nathan Goodyear on 25 Apr 12 - No Cached
  • Nathan Goodyear on 25 Apr 12
     
    this study looked at salivary testosterone and cortisol in exercise recovery.  They found a low T/C ratio in this athletes.  This is a catabolic state.  A normalization of the a low T/C ratio will increase muscle recovery and should improve performance.  Testing was with saliva
Nathan Goodyear

BMC Microbiology | Full text | The Firmicutes / Bacteroidetes ratio of the human microb... - 0 views

www.biomedcentral.com/...123

gut flora gut microbiome gut microbiota firmicutes bacteroidetes firmicutes_bacteroidetes health gut microbiome

shared by Nathan Goodyear on 06 May 15 - No Cached
  • The microbiota of the large intestine plays an important role in host metabolism and maintenance of host health
  • Our results defining a standard adult profile, together with previous reports, showed that C. leptum, C. coccoides, Bacteroides and Bifidobacterium represent the four dominant groups of the adult fecal microbiota
  • Sub-dominant groups are Lactobacilli Enterobacteriaceae, Desulfovibrio, Sporomusa, Atopobium as well as other bacterial groups including Clostridium clusters XI, XIVb, and XVIII
  • ...12 more annotations...
  • In infant fecal microbiota, we observed Bifidobacterium as the dominant group
  • this observation is strongly related to diet, being enhanced by breast feeding
  • Significant higher numbers of Bifidobacterium were observed in infants versus adults and seniors
  • the gastrointestinal tract is first colonized by facultative anaerobes, such as E. coli
  • Strict anaerobes, such as Clostridium, colonize at later stages, as can be seen by the relatively low levels of C. leptum and C. coccoides in infants
  • diet change must be considered among the primary causes for such a shift of microbiota between infants and adults.
  • In the case of elderly subjects, our qPCR results indicated a significant increase in the counts of E. coli when compared to adults. This data is consistent with other publications indicating that elderly subjects harbor a different E. coli microbiota profile compared to younger adults
  • a number of authors reported a reduction in the numbers and diversity of many protective commensal anaerobes, such as Bacteroides and Bifidobacteria
  • The Firmicutes to Bacteroidetes ratio was already shown to be of significant relevance in signaling human gut microbiota status
  • Our measurements of the Firmicutes/Bacteroidetes ratio in adults obtained by our species-specific qPCR are in agreement with those obtained by Ley et al
  • Compared with young adults, the elderly have a different digestive physiology, characterized at a physiological level by a reduction in transit and of digestive secretions
  • The Firmicutes/Bacteroidetes ratio undergoes an increase from birth to adulthood and is further altered with advanced age
  • Nathan Goodyear on 06 May 15
     
    Good discussion of the gut microbiome.  Age effects the gut bacteria balance.  The Firmicutes/Bacteroidetes ratio increases from young, to young adult, to the elderly in this study.  Is this simply a reflection of aging or is the a biomarker that can be changed through diet and targeted probiotics?
Nathan Goodyear

Urinary estrogen metabolites in women at high risk for breast cancer - 0 views

carcin.oxfordjournals.org/...1532.full

breast cancer CA estrogen metabolism 2:16 OHE 2-OH-estrone 16-alpha-OH-estrone

shared by Nathan Goodyear on 10 May 12 - No Cached
  • obesity has also been linked to preferential estrogen metabolism via the 16-alpha-hydroxylation pathway; thus, a prediction of the mechanism by which obesity could increase breast cancer risk would be through a lowering of the 2:16 ratio in favor of the 16 pathway
  • increased BMI was associated with a lower 2:16 OHE ratio
  • Our data show a significant association between alcohol use, defined as at least one drink per day or an average of seven per week, and 2:16 OHE ratio
  • ...10 more annotations...
  • An alcohol-induced rise in estrogens as a consequence of alcohol catabolism in the liver has been reported
  • The only study that looked at the association between alcohol and wine consumption in healthy women did not report a clear association
  • smoking has been reported to increase induction of the 2-hydroxylation metabolic pathway (24). However, the few epidemiological studies conducted on healthy women showed no difference in estrogen metabolites with smoking status (22) or smoking dose (20), in line with our findings.
  • Family history of a first-degree family member with breast cancer confers a 2- to 4-fold risk of developing breast cancer
  • 16% of breast cancers are due to unidentified hereditary factors
  • Estrogen metabolism occurs through enzymes whose activity is determined by the presence of specific genetic polymorphisms, thus can be defined as unique to each individual.
  • the metabolism is also influenced by a number of environmental factors, which change over a lifetime
  • significantly lower 2:16 OHE ratio in women who have known breast cancer risk factors compared with healthy women
  • There was an additional significant association specifically with BMI and alcohol use, which also supports the evidence that these factors affect estrogen metabolism
  • Profiling estrogen metabolites may identify women who are more likely to develop breast cancer within a population of women with known risk factors
  • Nathan Goodyear on 10 May 12
     
    urinary estrogen metabolites shown to provide insight into breast cancer risk.  This study suggested that a low 2:16 OHE ratio increase breast cancer risk.
Nathan Goodyear

Glutathione Redox Regulates Airway Hyperresponsiveness and Airway Inflammation in Mice ... - 0 views

www.atsjournals.org/...rcmb.2006-0423OC

glutathione asthma inflammation

shared by Nathan Goodyear on 07 Jul 16 - No Cached
  • γ-GCE reduced levels of IL-4, IL-5, IL-10, and the chemokines eotaxin and RANTES (regulated on activation, normal T cell expressed and secreted) in bronchoalveolar lavage fluid, whereas it enhanced the production of IL-12 and IFN-γ.
  • γ-GCE suppressed eosinophils infiltration
  • γ-GCE directly inhibited chemokine-induced eosinophil chemotaxis
  • ...10 more annotations...
  • these findings suggest that changing glutathione redox balance, increase in GSH level, and the GSH/GSSG ratio by γ-GCE, ameliorate bronchial asthma by altering the Th1/Th2 imbalance through IL-12 production from APC and suppressing chemokine production and eosinophil migration itself.
  • Bronchial asthma is a typical helper T cell type 2 (Th2) disease
  • Through the release of Th2 cytokines, such as IL-4, IL-5, and IL-13, orchestrate the recruitment and activation of the primary effector cells of the allergic response: the mast cells and the eosinophils
  • Glutathione is the most abundant nonprotein sulfhydryl compound in almost all cells. This tripeptide plays a significant role in many biological processes. It also constitutes the first line of the cellular defense mechanism against oxidative injury along with SOD, ascorbate, vitamin E, and catalase, and is the major intracellular redox buffer in ubiquitous cell types
  • We have shown that glutathione redox status, namely the balance between intracellular reduced (GSH) and oxidized (GSSG) glutathione, in murine antigen-presenting cells (APC) plays a central role in determining which of the reductive and oxidative APC predominate during immune status, and the balance between reductive and oxidative APC regulates Th1/Th2 balance through production of IL-12
  • we have also shown that exposure of human alveolar macrophages to the Th1 cytokine IFN-γ or the Th2 cytokine IL-4 either increases or decreases the GSH/GSSG ratio, respectively, which regulates Th1/Th2 balance through IL-12 production
  • the ability to generate a Th1 or Th2 type response has turned out to depend not only on T cells but also on the intracellular glutathione redox status of APC
  • Th1 cytokine IFN-γ and Th2 cytokine IL-4 increases and decreases the GSH/GSSG ratio, respectively, and that this ratio influences LPS-induced IL-12 production from alveolar macrophages
  • the ability to generate a Th1 or Th2 response is dependent on glutathione redox status of APC
  • administration of γ-GCE elevates GSH level and GSH/GSSG ratio in the lung, and ameliorates AHR and eosinophilic airway inflammation by altering the Th1/Th2 balance and suppressing chemokine production and eosinophil migration in a mouse asthma model
  • Nathan Goodyear on 07 Jul 16
     
    glutathione redox reaction plays an important role in the ability to balance Th1 and Th2 and thus disease potential i.e. asthma as this study example.  
Nathan Goodyear

Diet-Induced Dysbiosis of the Intestinal Microbiota and the Effects on Immunity and Dis... - 0 views

www.ncbi.nlm.nih.gov/...PMC3448089

dysbiosis diet nutrition metabolic endotoxemia disease inflammation gut

shared by Nathan Goodyear on 27 Jul 14 - No Cached
  • The gut microbiota participates in the body’s metabolism by affecting energy balance, glucose metabolism, and low-grade inflammation associated with obesity and related metabolic disorders
  • Firmicutes and Bacteroidetes represent the two largest phyla in the human and mouse microbiota and a shift in the ratio of these phyla has been associated with many disease conditions, including obesity
  • In obese humans, there is decreased abundance of Bacteroidetes compared to lean individuals
  • ...21 more annotations...
  • weight loss in obese individuals results in an increase in the abundance of Bacteroidetes
  • there is conflicting evidence on the composition of the obese microbiota phenotype with regards to Bacteroidetes and Firmicutes ratios
  • Bifidobacteria spp. from the phyla Actinobacteria, has been shown to be depleted in both obese mice and human subjects
  • While it is not yet clear which specific microbes are inducing or preventing obesity, evidence suggests that the microbiota is a factor.
  • targeted manipulation of the microbiota results in divergent metabolic outcomes depending on the composition of the diet
  • The microbiota has been linked to insulin resistance or type 2 diabetes (T2D) via metabolic syndrome and indeed the microbiota of individuals with T2D is also characterized by an increased Bacteroidetes/Firmicutes ratio, as well as an increase in Bacillus and Lactobacillus spp
  • It was also observed that the ratio of Bacteriodes-Prevotella to C. coccoides-E. rectale positively correlated with glucose levels but did not correlate with body mass index [80]. This suggests that the microbiota may influence T2D in conjunction with or independently of obesity
  • In humans, high-fat Western-style diets fed to individuals over one month can induce a 71% increase in plasma levels of endotoxins, suggesting that endotoxemia may develop in individuals with GI barrier dyfunction connected to dysbiosis
  • LPS increases macrophage infiltration essential for systemic inflammation preceding insulin resistance, LPS alone does not impair glucose metabolism
  • early treatment of dysbiosis may slow down or prevent the epidemic of metabolic diseases and hence the corresponding lethal cardiovascular consequences
  • increased Firmicutes and decreased Bacteroidetes, which is the microbial profile found in lean phenotypes, along with an increase in Bifidobacteria spp. and Lactobacillus spp
  • mouse and rat models of T1D have been shown to have microbiota marked by decreased diversity and decreased Lactobacillus spp., as well as a decrease in the Firmicutes/Bacteroidetes ratio
  • microbial antigens through the innate immune system are involved in T1D progression
  • The microbiota appears to be essential in maintaining the Th17/Treg cell balance in intestinal tissues, mesenteric and pancreatic lymph nodes, and in developing insulitis, although progression to overt diabetes has not been shown to be controlled by the microbiota
  • There is evidence that dietary and microbial antigens independently influence T1D
  • Lactobacillus johnsonii N6.2 protects BB-rats from T1D by mediating intestinal barrier function and inflammation [101,102] and a combination probiotic VSL#3 has been shown to attenuate insulitis and diabetes in NOD mice
  • breast fed infants have higher levels of Bifidobacteria spp. while formula fed infants have higher levels of Bacteroides spp., as well as increased Clostridium coccoides and Lactobacillus spp
  • the composition of the gut microbiota strongly correlates with diet
  • In mice fed a diet high in fat, there are many key gut population changes, such as the absence of gut barrier-protecting Bifidobacteria spp
  • diet has a dominating role in shaping gut microbiota and changing key populations may transform healthy gut microbiota into a disease-inducing entity
  • “Western” diet, which is high in sugar and fat, causes dysbiosis which affects both host GI tract metabolism and immune homeostasis
  • Nathan Goodyear on 27 Jul 14
     
    Nice discussion of how diet, induces gut bacterial change, that leads to metabolic endotoxemia and disease.
Nathan Goodyear

Estrogen Metabolism and Risk of Breast Cancer in Postmenopausal Women - 0 views

www.ncbi.nlm.nih.gov/...PMC3283536

estrogen metabolism estrogen metabolism breast cancer breast cancer

shared by Nathan Goodyear on 14 Oct 13 - No Cached
  • The ratio of the 2-hydroxylation pathway to parent estrogens was associated with a statistically significantly decreased risk of breast cancer
  • In this study, this ratio was more strongly associated with the risk of breast cancer compared with the ratio of 2-hydroxylation pathway to 16-hydroxylation pathway or unconjugated estradiol alone
  • 2-hydroxylation pathway catechols have relatively low affinities for estrogen receptors (4) and are rapidly cleared from circulation
  • ...6 more annotations...
  • In this study, the ratio of the 2-hydroxylation pathway to the 16-hydroxylation pathway was associated with a non-statistically significantly decreased risk of breast cancer
  • In this study, the ratio of catechols to methylated catechols in the 4-hydroxylation pathway was associated with statistically significantly increased risk of breast cancer.
  • This result is consistent with the hypothesis that mutagenic quinones derived from 4-hydroxylation pathway catechols contribute to pathogenesis of postmenopausal breast cancer.
  • Catechols in both the 2- and 4-hydroxylation pathways can be oxidized to form quinones; these reactive electrophiles can then react with DNA to form a variety of adducts
  • Methylation of the catechols prevents their conversion to reactive quinones
  • the most common DNA adducts derived from 4-hydroxylation pathway catechols are depurinating and highly mutagenic (7,40), most of those derived from 2-hydroxylation pathway catechols are stable and can be repaired with little error
  • Nathan Goodyear on 14 Oct 13
     
    Lower 2-OH estrone metabolism associated with lower risk of breast cancer, but 4-OH estrone associated with increased risk of breast cancer.
Nathan Goodyear

Urinary Estrogens and Estrogen Metabolites and Subsequent Risk of Breast Cancer among P... - 0 views

cancerres.aacrjournals.org/...696.full

estrogen metabolites estrogen metabolism ER estrogen receptors ROS hormones cancer breast cancer

shared by Nathan Goodyear on 07 Oct 15 - No Cached
  • both 2- and 4-catechol estrogen metabolites bind to the ER with affinities comparable with estradiol, 4-catechol estrogen metabolites have lower dissociation rates than estradiol and an enhanced ability to upregulate ER-dependent processes
  • 2-catechol estrogen metabolites act as either weak mitogens (39) or weak inhibitors of cell proliferation
  • While 16α-hydroxyestrone binds to the ER with lower affinity than estradiol, it binds covalently (41) and leads to a constitutively activated ER
  • ...15 more annotations...
  • 4-hydroxyestradiol and 16α-hydroxyestrone increasing proliferation and decreasing apoptosis in a manner similar to estradiol; however, these effects were achieved only at concentrations 10-fold higher than estradiol (39). In contrast, 2-hydroxyestradiol did not have substantial proliferative or antiapoptotic effects
  • In our study, the associations with both 2-hydroxyestrone and 16α-hydroxyestrone were nonsignificantly inverse and we did not observe a consistent trend or significant associations between the 2-hydroxyestrone:16α-hydroxyestrone ratio and breast cancer risk
  • Ratios of the 3 hydroxylation pathways were not significantly associated with risk although the 2:16-pathway and 4:16-pathway ratios were suggestively inversely associated
  • a significant inverse association with the ratio of parent estrogens to estrogen metabolites
  • several potentially estrogenic and genotoxic mechanisms
  • Estrogen metabolites also can be genotoxic
  • Catechol estrogens can be oxidized into quinones and induce DNA damage directly through the formation of DNA adducts, or indirectly via redox cycling and generation of reactive oxygen species
  • the oxidized forms of the catechol estrogens differ in their ability to damage DNA through adducts, with oxidized 2-catechols forming stable and reversible DNA adducts and oxidized 4-catechols forming unstable adducts, which lead to depurination and mutations
  • 2- and 4-catechols have been shown to produce reactive oxygen species and induce oxidative DNA damage
  • act independently from the ER
  • 16α-Hydroxyestrone also may be genotoxic
  • While the catechol estrogens have estrogenic and genotoxic potential, the methylated catechol estrogens, which are catechol estrogens with one hydroxyl group methylated, have been hypothesized to lower the risk of breast cancer
  • The suggested mechanisms are indirect, by decreasing circulating levels of catechol estrogens and thereby the opportunity for catechols to exert genotoxic or proliferative effects, or direct, by inhibiting tumor growth and inducing apoptosis
  • the balance between phase I (oxidation) and phase II (methylation) metabolism of estrogen may be important in hormonally related cancer development.
  • Despite the estrogenic and genotoxic potential of many of the estrogen metabolites, we only observed a significantly increased breast cancer risk with one estrogen metabolite, 17-epiestriol, which has particularly strong estrogenic activity and binds to both ERα and ERβ with an affinity comparable with estradiol
  • Nathan Goodyear on 07 Oct 15
     
    review of estrogen metabolites and breast cancer risk in premenopausal women.
Nathan Goodyear

Hormone Therapy, Estrogen Metabolism, and Risk of Breast Cancer in the Women's Health I... - 0 views

www.ncbi.nlm.nih.gov/...PMC3493689

breast cancer estrogen metabolites 2-OH-estrone 2:16 cancer hormones estrogen

shared by Nathan Goodyear on 11 Sep 15 - No Cached
  • These results demonstrate that although 16α-OHE1 was increased more by E+P than by E-alone, the increase in the 2:16 ratio was similar for both HT regimens, due to ~4-fold greater increase in 2OHE-1 than 16α-OHE1 for both HT regimens
  • baseline and 1 year change in 16α-OHE1 showed little relationship to incident breast cancer
  • higher baseline 2-OHE1 and the 2:16 ratio were modestly associated with higher odds of incident breast cancer, but larger 1 year increase in 2-OHE-1 and the 2:16 ratio were also weakly associated with lower odds of breast cancer
  • Nathan Goodyear on 11 Sep 15
     
    Good review of the data from the WHI-HT on estrogen metabolites and breast cancer risk.  Increased 2-OHestrone and 2:16 ratio without statistical significance reached.
Nathan Goodyear

Estrogen metabolite ratio: Is the 2-hydroxyestrone to 16α-hydroxyestrone rati... - 0 views

www.ncbi.nlm.nih.gov/...PMC3039007

breast cancer risk 2:16alpha-OHE1 estrogen metabolism ratio

shared by Nathan Goodyear on 23 Aug 11 - No Cached
  • Nathan Goodyear on 23 Aug 11
     
    in this study, estrogen metabolite ratio of 2:16alpha-OHE1 was found to not be predictive of breast cancer risk
Nathan Goodyear

Behaviour of saliva cortisol [C], testost... [Eur J Appl Physiol. 2003] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...12783234

saliva salivary hormone hormones testosterone cortisol T:C athlete athletic competition recovery

shared by Nathan Goodyear on 19 Feb 13 - No Cached
  • Nathan Goodyear on 19 Feb 13
     
    salivary hormone evaluation reveals cortisol increases during athletic  competition due primarily to a increase in salivary cortisol production.  The result is a decrease in T:C ratio during competition.  In the recovery phase, cortisol decreases to baseline, but the testosterone rises above baseline, thus increasing the T:C ratio in the recovery phase.  This lasted up to 5 days in this study.
Nathan Goodyear

Psychoendocrine and physical performan... [Aggress Behav. 2008 Nov-Dec] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...18626966

T:C training athlete athletics testosterone cortisol saliva salivary hormone hormones

shared by Nathan Goodyear on 19 Feb 13 - No Cached
  • Nathan Goodyear on 19 Feb 13
     
    Rugby training resulted in a decrease in T:C salivary ratio through a decline in resting testosterone level.  In contrast, competition events increased the T:C ratio primarily through an increase in Cortisol production.
Nathan Goodyear

The Firmicutes/Bacteroidetes ratio of the human microbiota changes with age | BMC Micro... - 0 views

bmcmicrobiol.biomedcentral.com/...1471-2180-9-123

gut gut health gut flora gut microbiota firmicutes_bacteroidetes metabolism

shared by Nathan Goodyear on 09 Nov 16 - No Cached
  • C. leptum, C. coccoides, Bacteroides and Bifidobacterium represent the four dominant groups of the adult fecal microbiota
  • Lactobacilli Enterobacteriaceae, Desulfovibrio, Sporomusa, Atopobium as well as other bacterial groups including Clostridium clusters XI, XIVb, and XVIII
  • The Firmicutes/Bacteroidetes ratio undergoes an increase from birth to adulthood and is further altered with advanced age
  • Nathan Goodyear on 09 Nov 16
     
    good review/discussion of gut microbiota, including the firmicutes:bacteroidetes ratio.
Nathan Goodyear

Estrogen metabolite ratio: is the 2-OH estrone to 16alph-OH estrone ratio predictive of... - 0 views

www.ncbi.nlm.nih.gov/...ijwh-3-037.pdf

estrogen metabolism cancer breast prostate metabolites 2-OH estrone 16alpha-OH

shared by Nathan Goodyear on 17 Feb 12 - No Cached
  • Nathan Goodyear on 17 Feb 12
     
    This is a recent review of the literature regarding estrogen metabolism. It has been proposed that 2:16 OH estrone ratio is predictive of breast, prostate cancer. This study does not find that association
Nathan Goodyear

Insulin, proinsulin, proinsulin:insulin ratio, and ... [Am J Med. 2003] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...12727576

type II 2 DM diabetes insulin proinsulin proinsulin:insulin ratio

shared by Nathan Goodyear on 04 Apr 12 - No Cached
  • Nathan Goodyear on 04 Apr 12
     
    Increased risk of developing type II diabetes found in women with elevated fasting insulin, proinsulin and increased proinsulin:insulin ratio
Nathan Goodyear

Reduced activation and increased ina... [J Clin Endocrinol Metab. 2003] - PubMed - NCBI - 0 views

www.ncbi.nlm.nih.gov/...12843166

inflammation illness thyroid hypothyroid hypothyroidism TSH free T3 rT3 T3:rT3 ratio

shared by Nathan Goodyear on 02 Feb 12 - No Cached
  • These observed changes, in correlation with a low T(3)/rT(3) ratio, may represent tissue-specific ways to reduce thyroid hormone bioactivity during cellular hypoxia and contribute to the low T(3) syndrome of severe illness.
  • Nathan Goodyear on 02 Feb 12
     
    inflammation and critical illness associated with low TSH, low T3, elevated rT3 and low T3:rT3 ratio.
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