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Nathan Goodyear

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

  • 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
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  • 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
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    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

PLOS ONE: Probiotic Microbes Sustain Youthful Serum Testosterone Levels and Testicular ... - 0 views

  • Studies in both humans and rodents, however, suggest that low testosterone is due to age-related lesions in testes rather than irregular luteinizing hormone metabolism
  • Various dietary factors and diet-induced obesity have been shown to increase the risk for late onset male hypogonadism and low testosterone production in both humans and mice
  • Testosterone deficiency and metabolic diseases such as obesity appear to inter-digitate in complex cause-and-effect relationships
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  • dietary supplementation of aged mice with the probiotic bacterium Lactobacillus reuteri makes them appear to be younger than their matched untreated sibling mice
  • These results indicate that gut microbiota induce modulation of local gastrointestinal immunity resulting in systemic effects on the immune system which activate metabolic pathways that restore tissue homeostasis and overall health
  • all these studies we consistently observed that young and aged mice consuming purified L. reuteri organisms had particularly large testes and a dominant male behavior.
  • The testes of probiotic-fed aged mice were rescued from both seminiferous tubule atrophy and interstitial Leydig cell area reduction typical of the normal aging process. Preservation of testicular architecture despite advanced age or high-fat diet coincided with remarkably high levels of circulating testosterone. The beneficial effects of probiotic consumption were recapitulated by the depletion of the pro-inflammatory cytokine Il-17.
  • feeding of L. reuteri consistently increased the gonadal weights, consumption of a non-pathogenic strain of Escherichia coli (E. coli) K12 organisms did not affect testicular weight
  • mice with dietary L. reuteri supplements were rescued from diet-induced obesity and had normal body weight and lean physique
  • Despite the comparable numbers of ST profiles, we determined that testes from L. reuteri-treated mice had increased ST cross-sectioned profiles
  • the probiotic organism induced prominent Leydig cell accumulations in the interstitial tissue between the ST's
  • The probiotic-associated increase of interstitial Leydig cell areas was sustained with advancing age at 7 (CD vs CD+LR, P = 0.0025; CD+E.coli vs CD+LR, P = 0.0251) and 12 months
  • mice eating L. reuteri had profoundly increased levels of circulating testosterone regardless of the type of diet they consumed
  • blocking pro-inflammatory Il-17 signaling entirely recapitulates the beneficial effects of probiotics
  • previous studies we found that dietary probiotics counteract obesity [19] and age-related integumentary pathology [18] at least in part by down-regulating systemic pro-inflammatory IL-17A-dependent signaling
  • Testes histomorphometry and serum androgen concentration data were both suggestive of a probiotic-associated up-regulation of spermatogenesis in mice
  • Lactobacillus reuteri we discovered that aging male animals had larger testes compared to their age-matched controls
  • xamined testes of probiotic microbe-fed mice and found that they had less testicular atrophy coinciding with higher levels of circulating testosterone compared to their age-matched controls
  • Similar testicular health benefits were produced using systemic depletion of the pro-inflammatory cytokine Il-17 alone, implicating a chronic inflammatory pathway in hypogonadism
  • One specific aspect of this paradigm is reciprocal activities of pro-inflammatory Th-17 and anti-inflammatory Treg cells
  • Feeding of L. reuteri organisms was previously shown to up-regulate IL-10 levels and reduce levels of IL-17 [19] serving to lower systemic inflammation
  • insufficient levels of IL-10 may increase the risk for autoimmunity, obesity, and other inflammatory disease syndromes
  • Westernized diets are also low in vitamin D, a nutrient that when present normally works together with IL-10 to protect against inflammatory disorders
  • Physiological feedback loops apparently exist between microbes, host hormones, and immunity
  • The hormone testosterone has been shown to act directly through androgen receptors on CD4+ cells to increase IL-10 expression
  • studies in both humans and rodents suggest that hypogonadism is due to age-related lesions in testes rather than irregular LH metabolism
  • We postulate that probiotic gut microbes function symbiotically with their mammalian hosts to impart immune homeostasis to maintain systemic and testicular health [34]–[35] despite suboptimal dietary conditions.
  • Dietary factors and diet-induced obesity were previously shown to increase risk for age-associated male hypogonadism, reduced spermatogenesis, and low testosterone production in both humans and mice [2]–[4], [8]–[11], [14]–[17], phenotypic features that in this study were inhibited by oral probiotic therapy absent milk sugars, extra protein, or vitamin D supplied in yogurt.
  • Similar beneficial effects of probiotic microbes on testosterone levels and sperm indices were reported in male mice that had been simultaneously supplemented with selenium
  • L. reuteri-associated prevention of age- and diet-related testicular atrophy correlates with increased numbers and size of Leydig cells
  • the initial changes of testicular atrophy begin to occur in mice from the age of 6 moths onwards [7] and indicates that the trophic effect of L. reuteri on Leydig cells is a key event which precedes and prevents age-related changes in the testes of mice. This effect is reminiscent of earlier studies describing Leydig cell hyperplasia and/or hypertrophy in the mouse and the rat testis that were achievable by the administration of gonadotropins, including human chorionic gonadotropin, FSH and LH
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    Fascinating study on how the addition of Lactobacillus reuteri increased Testicular size, prevented testicular atrophy, increased serum Testosterone production and protected against diet-induced/obesity-induced hypogonadism.  This was a mouse model
Nathan Goodyear

PLOS ONE: Depletion of Brain Docosahexaenoic Acid Impairs Recovery from Traumatic Brain... - 0 views

  • The polyunsaturated fatty acids linoleic (LA, 18:2n-6) and linolenic acid (LNA, 18:3n-3) are essential fatty acids that cannot be synthesized by the body.
  • LNA serves as the precursor for long chain omega-3 fatty acids such as docosahexaenoic acid (DHA) while LA is converted into long chain omega-6 fatty acids such as arachidonic acid (AA)
  • DHA and AA are abundantly found in the brain, where these are stored mainly in membrane phospholipids
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  • DHA has been shown to increase neurite outgrowth and synaptogenesis, and promotes glutamatergic neurotransmission through increase in glutamate receptor subunit expression
  • DHA has been shown to be converted to anti-inflammatory, proresolving and neuroprotective mediators, such as resolvins [7] and protectins
  • AA is converted by cyclooxygenases into 2-series prostaglandins and 4-series leukotrienes, most of which exert pro-inflammatory effects
  • Supplementation of DHA exerts neuroprotective effects and has been reported to afford protection from diffuse axonal injury [11] and mixed brain injury [12] as well
  • severe depletion of membrane DHA in the brain renders mice significantly more susceptible to TBI and impairs recovery following the injury
  • Omega-3 fatty acids may serve as nutraceutical agents and precondition the brain to make it more resilient to injury
  • it can be suggested that enriching DHA in the brain may be prophylactic and protective against brain injury
  • severe DHA deficiency in the brain impairs functional recovery from TBI in terms of vestibulo-motor and cognitive deficits
  • DHA deficiency further elevates TBI-induced production of SBDPs
  • less neurons were found around the injury site of DHA deficient brain after TBI compared to the omega-3 fatty acid adequate group
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    mouse study finds prolonged recovery in DHA deficient mice compared to controls.
Nathan Goodyear

Normalization of testosterone level is associated with reduced incidence of myocardial ... - 0 views

  • Normalized-TRT group had significantly fewer deaths than no-TRT
  • Mortality was also significantly lower in the non-normalized-TRT group compared with those in no-TRT group
  • the normalized-TRT group was associated with significantly increased all-cause mortality-free survival (log-rank, P < 0.05) compared with the non-normalized-TRT or no-TRT groups
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  • normalized-TRT group showed lower risk of MI than non-normalized-TRT (HR: 0.82, CI 0.71–0.95, P = 0.008) and no-TRT
  • normalized-TRT group had significantly lower stroke events compared with non-normalized-TRT (HR: 0.70, CI 0.51–0.96, P = 0.028) and no-TRT
  • study of men with low TT levels and without prior MI or stroke, normalization of TT levels using TRT is associated with lower all-cause mortality, fewer MIs, and ischaemic strokes
  • retrospective study
  • the first study to demonstrate that significant benefit is observed only if the dose is adequate to normalize the TT levels
  • Patients who failed to achieve the therapeutic range after TRT did not see a reduction in MI or stroke and had significantly less benefit on mortality
  • selected patients without any previous history of MI or stroke prior to initiation of TRT to reduce bias related to CV outcomes
  • currently only half of the men on TRT had been diagnosed with hypogonadism.
  • 25% of users did not have their T concentrations tested prior to initiating therapy, and 21% of those prescribed TRT did not have their levels tested at any time during treatment.
  • men without a history of previous MI or stroke who have low TT levels, TRT might be associated with decreased risks of MI, ischaemic stroke, and all-cause mortality in long-term follow-up
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    Testosterone therapy in men with low T found to reduce all cause mortality, stroke and MI.
Nathan Goodyear

Effects of thyroxine as compared with thyroxine pl... [N Engl J Med. 1999] - PubMed result - 0 views

  • n patients with hypothyroidism, partial substitution of triiodothyronine for thyroxine may improve mood and neuropsychological function;
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    Effects of thyroxine as compared with thyroxine plus triiodothyronine in patients with hypothyroidism.
Nathan Goodyear

Menopausal Complaints Are Associated With Cardiovascular Risk Factors - 0 views

  • women with complaints of flushing or night sweats have an unfavorable cardiovascular risk profile compared with women without vasomotor complaints and with increased cholesterol levels, systolic and diastolic blood pressures, and BMI.
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    Women with hot flashes and night sweats have increased cardiovascular risk compared to women that do not.
Nathan Goodyear

Implications of free radicals and antioxidant levels in carcinoma of the breast: A neve... - 0 views

  • Experimental investigations as well as clinical and epidemiological findings have provided evidence supporting the role of reactive oxygen metabolites or free radicals such as singlet oxygen O 2 - , superoxide anions (O 2 ), hydrogen peroxide (H­2 O2 ) and hydroxyl radical in the etiology of cancer.
  • Certain aldehydes such as Malonyldialdehyde (MDA), the end product of lipid peroxidation arising from free radical degeneration of polyunsaturated fatty acids can cause cross linking in lipids, proteins and nucleic acids leading to cellular damage.
  • In this study, patients with cancer exhibited higher levels of MDA, both in tissues and serum (p<0.001) compared to the control group [Table 1]. In tissue, the MDA level in stage IV was significantly higher as compared to stage I indicating increased free radical activity with increasing severity of cancer
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  • From these observations, it can be concluded that MDA levels play an important role in assessing the outcome of cancer
  • SOD and CAT are considered primary antioxidant enzymes, since they are involved in direct elimination of reactive oxygen metabolites. [13-16] They also act as anti-carcinogens and inhibitors at initiation and promotion/transformation stage in carcinogenesis
  • In our study, SOD and CAT levels were found to be low in all cancer patients as compared to controls
  • Fridovich and Tayarani have demonstrated in their respective studies that the reduction in SOD activity increases the toxic effects of O2 - and this might lead to severe cellular damage.
  • Mehrotra et al. in their study also observed high levels of MDA and low levels of SOD and CAT in patients of cancer cervix which is in sync with our observations.
  • strong evidence regarding the definitive role of free radicals in breast malignancy.
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    This study finds a strong correlation between advancing breast cancer, decreased catalase and SOD with increasing MDA.  The authors of this study conclude this is a key factor in carcinogenesis and not a by-product of cancer.  This flies in the face of traditional medicines fear of antioxidant therapy in cancer.
Nathan Goodyear

Statin use and risk of diabetes mellitus - 0 views

  • An increase in new onset diabetes, i.e., 3% in statin arm and 2.4% in placebo arm was reported. This was accompanied by increase in median value of glycated haemoglobin and was one of the earlier studies to report the increase in new onset diabetes in patients on statins
  • Even after adjustment for potential confounders, statin therapy was associated with an increased risk of new-onset diabetes mellitus
  • Authors suggest that statin-induced diabetes mellitus is a medication class effect
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  • Another study also reported that as compared to placebo, statin group showed a higher risk of physician reported incident diabetes and it was also observed that risk was higher in women as compared to men
  • Meta-analysis of randomized controlled trials by Sattar et al[25] involving 91140 non-diabetic patients showed that statin therapy was associated with 9% increased risk of incident diabetes
  • A number of studies showed dose dependent association between statin administration and incident diabetes
  • downregulation of GLUT4
  • Treatment with atorvastatin and simvastatin may be associated with an increased risk of new onset diabetes as compared to pravastatin
  • Increased incidence of diabetes was seen with atorvastatin in the Anglo-Scandinavian Cardiac Outcomes Trial
  • Increased insulin resistance secondary to statins was demonstrated in a prospective non randomised study in patients with coronary bypass surgery
  • intensive dose of statins was associated with high incidence of new - onset diabetes
  • Prevention of coronary and stroke events with atorvastatin in hypertensive patients who have average or lower-than-average cholesterol concentrations, in the Anglo-Scandinavian Cardiac Outcomes Trial--Lipid Lowering Arm (ASCOT-LLA): a multicentre randomised controlled trial
  • Prevention of coronary and stroke events with atorvastatin in hypertensive patients who have average or lower-than-average cholesterol concentrations, in the Anglo-Scandinavian Cardiac Outcomes Trial--Lipid Lowering Arm (ASCOT-LLA): a multicentre randomised controlled trial
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    Great review article of the increased risk of worsening insulin resistance, glycated hemoglobin, and diabetes risk.  Atorvastatin appears to be the worst culprit.  Mechanism partially through a decrease in GLUT4.
Nathan Goodyear

American Journal of Obstetrics & Gynecology Home Page - 0 views

  • M1 macrophages are characterized by the secretion of reactive oxygen species and proinflammatory cytokines and chemokines and can be identified via the cell surface marker CD86
  • M2 macrophages secrete growth factors and antiinflammatory immune modulators and can be identified by the cell surface marker CD206
  • an overzealous M2 response can also lead to excess tissue deposition and fibrosis
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  • Studies of similar meshes that are used in hernia repair have demonstrated that all polypropylene meshes induce a prolonged inflammatory response at the site of implantation
  • the long-term presence of activated inflammatory cells, such as macrophages at the mesh tissue interface, can impact negatively the ability of the mesh to function as intended.
  • All M1 proinflammatory and M2 proremodeling cytokines and chemokines were increased in mesh explants as compared with nonmesh tissue (Table 3Table 3), which indicated a robust, active, and ongoing host response to polypropylene long after implantation
  • Comparison of the ratio of the M2 proremodeling cytokines (IL-10+IL-4) with the M1 proinflammatory cytokines (TNF-α+IL-12p70) revealed a decrease in mesh explants as compared with controls (P = .003), which indicated a shift towards a proinflammatory profile.
  • Mesh explants contained a higher number of total cells/×200 field when compared with controls (682.46 ± 142.61 cells vs 441.63 ± 126.13 cells; P < .001) and a lower ratio of M2:M1 macrophages (0.260 ± 0.161 cells vs 1.772 ± 1.919; P = .001), which supported an ongoing proinflammatory response.
  • the host response was proportional to the amount of material in contact with the host
  • A persistent foreign body response was observed in mesh-tissue complexes that were excised from women who required surgical excision of mesh months to years after mesh implantation
  • The host response was characterized by a predominance of macrophages with an increase in both proinflammatory and proremodeling cytokines/chemokines along with increased tissue degradation, as evidenced by increased MMP-2 and -9
  • Mesh-tissue complexes removed for mesh exposure had increased pro–MMP-9 that indicated a proinflammatory and tissue destruction–type response
  • The presence of macrophages, elevated cytokines, chemokines, and MMPs in tissue-mesh complexes that were excised from patients with exposure or pain suggests that polypropylene mesh elicits an ongoing host inflammatory response
  • In the presence of a permanent foreign body, the implant is surrounded with a fibrotic capsule because it cannot be degraded
  • For hernia meshes, if the fibers are too close (<1 mm), the fibrotic response to neighboring fibers overlaps, or “bridges,” and results in “bridging fibrosis” or encapsulation of the mesh
  • Gynemesh PS has a highly unstable geometry when loaded that resulted in pore collapse and increasing stiffness of the product
  • mesh shrinkage (50-70%) has been described to occur after transvaginal insertion of prolapse meshes
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    Mesh and the abnormal immune response.
Nathan Goodyear

Pharmacological Ascorbate Radiosensitizes Pancreatic Cancer - 0 views

  • Previous studies from our laboratory have demonstrated that pharmacological ascorbate is cytotoxic to pancreatic cancer cells while normal cells are resistant
  • Ascorbate-induced cytotoxicity is mediated by the formation of H2O2 during the oxidation of ascorbate
  • the combination of IR + ascorbate increased the concentration of intracellular H2O2
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  • Under steady-state conditions, intracellular GSH is maintained at millimolar concentrations, which keeps cells in a reduced environment and serves as the principal intracellular redox buffer when cells are subjected to an oxidative stressor including H2O2 (26). Glutathione peroxidase (GPx) activity catalyzes the reduction of H2O2 to water with the conversion of GSH to glutathione disulfide (GSSG). Under steady-state conditions, GSSG is recycled back to GSH by glutathione disulfide reductase using reducing equivalents from NADPH. However, under conditions of increased H2O2 flux, this recycling mechanism may become overwhelmed leading to a depletion of intracellular GSH (27, 28).
  • ascorbate radiosensitization can create an overwhelming oxidative stress to pancreatic cancer cells resulting in oxidation/depletion of the GSH intracellular redox buffer, resulting in cell death.
  • Treatment with the combination of ascorbate + IR significantly delayed tumor growth compared to controls or ascorbate alone
  • Ascorbate + IR also significantly increased overall survival compared to controls, IR alone or ascorbate alone
  • 54% of mice treated with the combination of IR + ascorbate had no measurable tumors
  • Glutathione is a measurable marker indicative of the oxidation state of the thiol redox buffer in cells. In severe systemic oxidative stress, the GSSG/2GSH couple may become oxidized, i.e. the concentration of GSH decreases and GSSG may increase because the capacity to recycle GSSG to GSH becomes rate-limiting
  • This suggests that the very high levels of pharmacological ascorbate in these experiments may have a pro-oxidant toward red blood cells as seen by a decrease in the capacity of the intracellular redox buffer
  • These data support the hypothesis that ascorbate radiosensitization does not cause an increase in oxidative damage from lipid-derived aldehydes to other organs.
  • Our current study demonstrates the potential for pharmacological ascorbate as a radiosensitizer in the treatment of pancreatic cancer.
  • pharmacological ascorbate enhances IR-induced cell killing and DNA fragmentation leading to induction of apoptosis in HL60 leukemia cells
  • pharmacological ascorbate significantly decreases clonogenic survival and inhibits the growth of all pancreatic cancer cell lines as a single agent, as well as sensitizes cancer cells to IR
  • Hurst et al. demonstrated that pharmacological ascorbate combined with IR leads to increased numbers of double-strand DNA breaks and cell cycle arrest when compared to either treatment alone
  • pharmacological ascorbate could serve as a “pro-drug” for the delivery of H2O2 to tumors
  • the double-strand breaks induced by H2O2 were more slowly repaired
  • The combination of ascorbate and IR provide two distinct mechanisms of action: ascorbate-induced toxicity due to extracellular production of H2O2 that then diffuses into cells and causes damage to DNA, protein, and lipids; and radiation-induced toxicity as a result of ROS-induced damage to DNA. In addition, redox metal metals like Fe2+ may play an important role in ascorbate-induced cytotoxicity. By catalyzing the oxidation of ascorbate, labile iron can enhance the rate of formation of H2O2; labile iron can also react with H2O2. Recently our group has demonstrated that pharmacological ascorbate and IR increase the labile iron in tumor homogenates from this murine model of pancreatic cancer
  • we demonstrated that ascorbate or IR alone decreased tumor growth, but the combination treatment further inhibited tumor growth, indicating that pharmacological ascorbate is an effective radiosensitizer in vivo
  • data suggest that pharmacological ascorbate may protect the gut locally by decreasing IR-induced damage to the crypt cells, and systemically, by ameliorating increases in TNF-α
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    IV vitamin C effective as radiosensitizer in pancreatic cancer.
Nathan Goodyear

Crescent pyramid and drop-set systems do not promote greater strength gains, muscle hyp... - 0 views

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    no training benefit with pyramid and drop-set workouts compared to traditional resistance training.  The key is repeitition, proper technique and just doing it.
Nathan Goodyear

Ibuprofen alters human testicular physiology to produce a state of compensated hypogona... - 0 views

  • The levels of LH in the ibuprofen group had increased by 23% after 14 d of administration
  • This increase was even more pronounced at 44 d, at 33%
  • We found an 18% decrease (P = 0.056) in the ibuprofen group compared with the placebo group after 14 d (Fig. 1A) and a 23% decrease (P = 0.02) after 44 d (Fig. 1C). Taken together, these in vivo data suggest that ibuprofen induced a state of compensated hypogonadism during the trial, which occurred as early as 14 d and was maintained until the end of the trial at 44 d
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  • We first investigated testosterone production after 24 and 48 h of ibuprofen exposure to assess its effects on Leydig cell steroidogenesis. Inhibition of testosterone levels was significant and dose-dependent (β = −0.405, P = 0.01 at 24 h and β = −0.664, P < 0.0001 at 48 h) (Fig. 2A) and was augmented over time
  • The AMH data show that the hypogonadism affected not only Leydig cells but also Sertoli cells and also occurred as early as 14 d of administration
  • Sertoli cell activity showed that AMH levels decreased significantly with ibuprofen administration, by 9% (P = 0.02) after 14 d (Fig. 1B) and by 7% (P = 0.05) after 44 d compared with the placebo group
  • Examination of the effect of ibuprofen exposure on both the ∆4 and ∆5 steroid pathways (Fig. 2B) showed that it generally inhibited all steroids from pregnenolone down to testosterone and 17β-estradiol; the production of each steroid measured decreased at doses of 10−5–10−4 M. Under control conditions, production of androstenediol and dehydroepiandrosterone (DHEA) was below the limit of detection except in one experiment with DHEA
  • Measuring the mRNA expression of genes involved in steroidogenesis in vitro showed that ibuprofen had a profound inhibitory effect on the expression of these genes (Fig. 3 B–D), consistent with that seen above in our ex vivo organ model. Taken together, these data examining effects on the endocrine cells confirm that ibuprofen-induced changes in the transcriptional machinery were the likely reason for the inhibition of steroidogenesis.
  • Suppression of gene expression concerned the initial conversion of cholesterol to the final testosterone synthesis. Hence, expression of genes involved in cholesterol transport to the Leydig cell mitochondria was impaired
  • A previous study reported androsterone levels decreased by 63% among men receiving 400 mg of ibuprofen every 6 h for 4 wk
  • We next examined the gene expression involved in testicular steroidogenesis ex vivo and found that levels of expression of every gene that we studied except CYP19A1 decreased after exposure for 48 h compared with controls
  • the changes in gene expression indicate that the transcriptional machinery behind the endocrine action of Leydig cells was most likely impaired by ibuprofen exposure.
  • Together, these data show that ibuprofen also directly impairs Sertoli cell function ex vivo by inhibiting transcription
  • ibuprofen use in men led to (i) elevation of LH; (ii) a decreased testosterone/LH ratio and, to a lesser degree, a decreased inhibin B/FSH ratio; and (iii) a reduction in the levels of the Sertoli cell hormone AMH
  • The decrease in the free testosterone/LH ratio resulted primarily from the increased LH levels, revealing that testicular responsiveness to gonadotropins likely declined during the ibuprofen exposure. Our data from the ex vivo experiments support this notion, indicating that the observed elevation in LH resulted from ibuprofen’s direct antiandrogenic action
  • AMH levels were consistently suppressed by ibuprofen both in vivo and ex vivo, indicating that this hormone is uncoupled from gonadotropins in adult men. The ibuprofen suppression of AMH further demonstrated that the analgesic targeted not only the Leydig cells but also the Sertoli cells, a feature encountered not only in the human adult testis but also in the fetal testis
  • ibuprofen displayed broad transcription-repression abilities involving steroidogenesis, peptide hormones, and prostaglandin synthesis
  • a chemical compound, through its effects on the signaling compounds, can result in changes in the testis at gene level, resulting in perturbations at higher physiological levels in the adult human
  • The analgesics acetaminophen/paracetamol and ibuprofen have previously been shown to inhibit the postexercise response in muscles by repressing transcription
  • Previous ex vivo studies on adult testis have indeed pointed to an antiandrogenicity, only on Leydig cells, of phthalates (41), aspirin, indomethacin (42), and bisphenol A (BPA) and its analogs
  • ibuprofen’s effects were not restricted to Leydig and Sertoli cells, as data showed that the expression of genes in peritubular cells was also affected
  • short-term exposure
  • In the clinical setting, compromised Leydig cell function resulting in increased insensitivity to LH is defined as compensated hypogonadism (4), an entity associated with all-cause mortality
  • compensated hypogonadic men present with an increased likelihood of reproductive, cognitive, and physical symptoms
  • an inverse relationship was recently reported between endurance exercise training and male sexual libido
  • AMH concentrations are lower in seminal plasma from patients with azoospermia than from men with normal sperm levels
  • inhibin B is a key clinical marker of reproductive health (32). The function of AMH, also secreted by Sertoli cells, and its regulation through FSH remain unclear in men
  • the striking dual effect of ibuprofen observed here on both Leydig and Sertoli cells makes this NSAID the chemical compound, of all the chemical classes considered, with the broadest endocrine-disturbing properties identified so far in men.
  • after administration of 600 mg of ibuprofen to healthy volunteers
  • 14 d or at the last day of administration at 44 d
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    ibuprofen alters genetic expression that results in decreased Testosterone production.
Nathan Goodyear

A Comparative Analysis of Low-Dose Metronomic Cyclophosphamide Reveals Absent or Low-Gr... - 0 views

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    Low-dose chemotherapy significantly reduced toxicity compared to maximum tolerated dosing.
Nathan Goodyear

Ascorbate in pharmacologic concentrations selectively generates ascorbate radical and h... - 0 views

  • Proposed mechanism
  • The data show that pharmacologic ascorbate concentrations produced Asc•− selectively in extracellular fluid compared with blood and that H2O2 formation occurred when Asc•− concentrations were >100 nM in extracellular fluid.
  • These data validate the hypothesis that ascorbate is a prodrug for selective delivery of reactive species to the extravascular space
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  • pharmacologic ascorbate as a prooxidant drug for therapeutic use.
  • Recently we reported that pharmacologic ascorbic acid concentrations produced H2O2 concentrations of ≥25 μM, causing cancer cell death in vitro
  • We found that H2O2 concentrations generated in vivo were those that caused cancer cell death in vitro
  • When ascorbate was given parenterally, Asc•−, the product of a loss of one electron from ascorbate, was detected preferentially in extracellular fluid compared with blood
  • Asc•− generation in extracellular fluid depended on the ascorbate dose and the resulting concentrations
  • With i.v. administration of ascorbate, Asc•− concentrations were as much as 12-fold greater in extracellular fluid compared to blood and approached 250 nM
  • In blood, such Asc•− concentrations were never produced and were always <50 nM
  • These data are all consistent with the hypothesis that pharmacologic ascorbate concentrations in vivo serve as a prodrug for selective delivery of H2O2 to the extracellular space
  • After oral ingestion, control of intracellular and extracellular ascorbate concentrations is mediated by three mechanisms: intestinal absorption, tissue transport, and renal reabsorption
  • intestinal absorption, or bioavailability, declines at doses >200 mg
    • Nathan Goodyear
       
      significant limitation of gut absorption of vitamin C--at 200 mg po.
  • corresponding to plasma concentrations of ≈60 μM
    • Nathan Goodyear
       
      equates to 0.06 mM.  Max blood levels found with po AA dosing has been 0.22 mM
  • at approximately this concentration, the ascorbate tissue transporter SVCT2 approaches Vmax, and tissues appear to be saturated
    • Nathan Goodyear
       
      SVCT2 Rc in gut reach max binding.
  • also at ≈60 μM, renal reabsorption approaches saturation, and excess ascorbate is excreted in urine
  • Parenteral administration bypasses tight control
  • When tight control is bypassed, H2O2 forms in the extracellular space
  • in vivo validation of ascorbate as a prodrug for selective H2O2 formation
  • Temporarily bypassing tight control with parenteral administration of ascorbate allows H2O2 to form in discrete time periods only, decreasing likelihood of harm, and provides a pharmacologic basis for therapeutic use of i.v. ascorbate
  • H2O2 formation results in selective cytotoxicity
  • Tumor cells are killed with exposure to H2O2 for ≤30 min
  • In vitro, killing is mediated by H2O2 rather than Asc•−
  • In addition to cancer treatment, another potential therapeutic use is for treatment of infections. H2O2 concentrations of 25–50 μM are bacteriostatic
  • virally infected cells may also be candidates
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    follow up invivo study to previous study from 2005.  Here, the authors prove their hypothesis that ascorbate is a prodrug for delivery of H2O2.
Nathan Goodyear

Testosterone Concentrations In Young P... [Clin Endocrinol (Oxf). 2012] - PubMed - NCBI - 0 views

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    New study shows that obese boys/young men pre and post puberty have up to 50% lower testosterone levels than comparative normal BMI counterparts.  Also of note, estradiol levels were not associated with the low testosterone levels.
Nathan Goodyear

Testosterone treatment and mortality... [J Clin Endocrinol Metab. 2012] - PubMed - NCBI - 0 views

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    Testosterone treatment shown to decrease mortality in group of men compared to a no testosterone treatment group.  This study used serum testosterone as it's evaluative method.  They used the cut of of < 250 ng/dl which is very, very low!  This is another study that shows that testosterone for men that need it is much more than just ED and low libido.
Nathan Goodyear

A Cohort Effect on Serum Testosterone Levels in Finnish Men - 0 views

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    Finnish study of 3,271 men found that there was a decline in serum free testosterone levels in recently born boys compared to previous generations.  Additionally, they found inappropriate HPA response to this decline in testicular testosterone.
Nathan Goodyear

Age Trends in the Level of Serum Testosterone and Other Hormones in Middle-Aged Men: Lo... - 0 views

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    This study found that in longitudinal studies, testosterone decline accelerated compared to cross sectional studies.  They concluded that decreasing health could be the explanation.  But, what if the decline in testosterone explained the decreasing health?
Nathan Goodyear

JAMA Network | JAMA | Sex Differences of Endogenous Sex Hormones and Risk of Type 2 Dia... - 0 views

  • lack of reliable data on levels of free hormones
  • endogenous levels of testosterone and SHBG each exhibit sex-dependent relations with risk of type 2 diabetes
  • high testosterone levels were associated with greater type 2 diabetes risk in women but lower risk in men
  • ...1 more annotation...
  • the inverse association of SHBG was stronger in women than in men
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    No surprise, testosterone in men and women have different effects.  I just wrote a post on this.  Testosterone is positively associated with increased risk of diabetes in women, but inversely with men.  That is increased T in women equals increased Diabetes in women; contrast with increased T associated with decreased Diabetes in men.   But the interesting point is SHBG.  This study found a strong inverse association between SHBG with diabetes in women when compared to men.  Meaning: low SHBG is associated with an increased risk of type II Diabetes.  This is at the same time that testosterone is associated with an increased risk.
Nathan Goodyear

Lipid peroxidation in hemodialysis patients: ef... [Clin Biochem. 2008] - PubMed - NCBI - 0 views

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    IV vitamin C shown to reduce AGE and lipid hydroperoxide levels post IV vitamin C when compared prior and controls.
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