Biomedical subjects

Mary Ann Emanuele

Publications and source records attributed to Mary Ann Emanuele.

11 recordsLinked to original sources

PubMed2005

The impact of burn injury and ethanol on the cytokine network of the mouse hypothalamus: reproductive implications.

Nearly 50% of the patients admitted to hospitals for burn injuries have detectable levels of alcohol (EtOH) in their circulation. In fact, EtOH is often a causal factor in their injury. It is well known that EtOH as well as burn injury disrupt function of the hypothalamic-pituitary-gonadal (HPG) axis. The cellular mechanisms by which EtOH and/or burn impacts on the HPG are not entirely understood. In the studies reported here, we tested the hypothesis that these injuries mediated their effects by local hypothalamic inflammation. Young adult male mice were subjected to either a 15% total body surface area, full thickness scald, to EtOH, or to both and compared to appropriate controls. They were sacrificed 48 h later. EtOH and burn, as well as the combined injury, consistently and impressively reduced serum testosterone, while increasing hypothalamic concentrations of all three of the pro-inflammatory cytokines, TNFalpha, IL-1beta, and IL-6. In general, the increases induced by burn were greater than those caused by EtOH and the effect of the combined insult was not additive. Hypothalamic concentrations of LHRH were also increased. The data are consistent with the idea that EtOH and/or burn, as models of critical illness, medicate their hypothalamic suppressive effects via increase in pro-inflammatory cytokines.

Animals↗

PubMed2005

Ethanol-induced alterations in Rab proteins: possible implications for pituitary dysfunction.

Chronic exposure of pubertal male rats to ethanol results in a decline in serum testosterone, increased gonadotropins, pituitary luteinizing hormone (LH) and follicle stimulating hormone (FSH) content, and decreased or inappropriately normal serum LH and FSH levels, suggesting impaired secretory release of gonadotropins. The molecular mechanisms behind this disorder are undefined, but a disruption of vesicle-mediated secretory processes is possible because intracellular protein trafficking pathways are involved in secretion of glycoproteins such as FSH and LH. Because small GTP-binding proteins of Rab family have been implicated as key regulators of membrane and protein trafficking in mammalian cells, this study was designed to test if ethanol-impaired pituitary FSH and LH secretion is associated with changes in Rab proteins, particularly Rab1B, Rab3B, Rab6, and Rab11. Male Sprague-Dawley rats 35 days old were pair-fed a Lieber-DeCarli diet with ethanol or without ethanol for 5 to 60 days. After ethanol exposure, serum testosterone levels decreased while LH and FSH were inappropriately unchanged. Immunohistochemical staining showed decreased Rab1B, Rab3B, and Rab11 protein levels in ethanol-treated pituitaries. Immunoblotting showed that ethanol induced a transient reduction in Rab6 after 5 days of ethanol exposure, whereas Rab3B decreased after 20 days, Rab11 after 30 days, and Rab1B after 60 days. Despite these changes in Rab proteins, mRNA levels were unaffected by ethanol exposure. We concluded that reductions in key Rab proteins may lead to altered vesicle trafficking and may play a role in disruption of pituitary FSH and LH secretion caused by ethanol.

Animals↗

PubMed2005

Exposure to ethanol induces oxidative damage in the pituitary gland.

Chronic exposure of pubertal male rats to ethanol results in a decline in serum testosterone and decreased or inappropriately normal serum luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels suggesting a functional defect in the pituitary. The molecular mechanisms behind this disorder are undefined. A role for ethanol-induced oxidative damage in the pathophysiology is supported by studies in liver, muscle, and heart of experimental animals, but there is limited evidence in the pituitary. We examined markers of oxidative damage to lipids and proteins in pituitaries from rats consuming ethanol for 5, 10, 20, 30, and 60 days in addition to markers of damage to nucleic acids in pituitaries after 60 days of ethanol exposure. There were increases in 8-oxo-deoxyguanosine immunoreactivity, a marker of oxidative damage to nucleic acids, and an overall increase in malondialdehyde and 4-hydroxynonenal, markers of lipid peroxidation. Protein carbonylation and protein nitrotyrosination, markers of protein oxidation, were significantly increased after 30 days and 60 days of ethanol consumption, respectively. After 60 days of ethanol exposure, TUNEL assay revealed that cell death in the ethanol-treated pituitaries was not significantly different from that in the pair-fed controls at the time of examination. We also measured serum testosterone, FSH, and LH after ethanol consumption for 5, 10, 20, 30, and 60 days. Through 5 to 60 days of ethanol exposure, testosterone levels were consistently lower whereas LH and FSH were inappropriately unchanged, suggesting pituitary malfunction. These results provide evidence for ethanol-induced oxidative damage at the pituitary level, which may contribute to pituitary dysfunction.

Aldehydes↗

PubMed2005

Effects of chronic ethanol (EtOH) administration on pro-inflammatory cytokines of the hypothalamic-pituitary-gonadal (HPG) axis in female rats.

We and others have investigated the effects of acute and chronic ethanol (EtOH) administration on function of the hypothalamic-pituitary-gonadal (HPG) axis in female rats, consistently finding EtOH to be detrimental. There are now substantial data that pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNFalpha) and interleukin 6 (IL-6), have anti-reproductive effects. If EtOH increased levels of these cytokines, such data would be consistent with, though not necessarily prove, a cytokine mediated mechanism for EtOH's deleterious effects on reproduction. Young adult female Sprague Dawley rats were used. In the experiment reported here, the Lieber DeCarli diet was used, with animals fed a 36% EtOH containing diet or pair fed an identical diet which contained dextrimaltose instead of EtOH. This was done for 4 to 6 weeks. TNFalpha and IL-6 were measured in the hypothalamus, pituitary, and ovary by ELISA. EtOH exposure resulted in significant increases in TNFalpha and IL-6 in hypothalami, pituitaries, and ovaries. The data reported here are the first to show consistent stimulatory effects of EtOH exposure on cytokines in the reproductive axis of female rats. Because the effects of these cytokines are generally anti-reproductive, these data provide a rational for more rigorous testing of the notion that part of EtOH's deleterious HPG effects may be due to such immuno-endocrine interactions.

Animals↗

PubMed2005

Latent autoimmune diabetes of adulthood. Unique features that distinguish it from types 1 and 2.

A number of patients with poor glycemic control receive the diagnosis of type 2 diabetes despite the fact that they do not exhibit some of the traditional characteristics of the disease, such as obesity. A more accurate diagnosis for many of these patients is latent autoimmune diabetes of adulthood (LADA). In this article, Dr Nabhan and coauthors describe features that LADA has in common with type 1 and type 2 diabetes, as well as those that distinguish LADA from these more widely recognized forms of diabetes. The authors also describe the pathogenesis of the disease, potential complications, and treatment options.

Autoantibodies↗

PubMed2003

Hepatic apoptosis and proliferation in male and female rats fed alcohol: role of cytokines.

BACKGROUND: The female liver is more sensitive to the toxic effect of chronic alcohol intake than the male liver. The aim of the study was to compare the influence of gender and sex hormonal status on apoptosis and cell proliferation following chronic ethanol intake. METHODS: Male and female rats were pair fed for 8 weeks a liquid diet containing 36% of their total daily calories as ethanol (ETOH group) or sucrose (control group). Liver samples were analyzed for apoptosis and hepatocyte proliferation by immunohistochemistry. The hepatic production of factors able to influence cell death and proliferation, such as tumor necrosis factor alpha (TNFalpha) and interleukin 6 (IL-6) were determined. RESULTS: In both male and female rats, ethanol intake promoted apoptosis in the liver. This effect of ethanol was more evident in female than male rat livers. Hepatic TNFalpha levels, which promote apoptosis, are significantly more elevated in female than in male livers. Hepatic IL-6 production, which promotes hepatocyte proliferation, was induced by ethanol only in males, but not female animals. CONCLUSION: This observed difference in cytokine responses may contribute to the enhanced sensitivity of female liver to EtOH-induced injury.

Animals↗

PubMed2002

Hepatic estrogen receptors and alcohol intake.

Human liver contains estrogen receptors (ER) which render it sensitive to estrogen. Chronic ethanol ingestion in humans and rats results in alterations of circulating sex steroid levels and expression of sex hormone-dependent phenotype. The analysis and quantitation of hepatic estrogen receptor (ER) activity and sex hormone-responsive proteins have been performed over the past two decades. Alcohol abuse appears to induce an increase in ER content of human liver, especially in patients with alcoholic hepatitis actively drinking. This observation is reproduced in an experimental model of chronic alcohol feeding of rats. In male rat liver, the increased ER expression induced by alcohol is associated with an elevated proliferation rate of the hepatocytes. In female liver, the ER content is not affected by alcohol intake and apoptosis prevails over proliferation. The feminization of the liver in males may protect the liver from the severe alcohol-induced liver injury seen in females.

Animals↗

PubMed2002

Clinical trial evidence for cardiovascular risk reduction in type 2 diabetes.

Major clinical trials have shown that excellent glycemic control, sustained over time, can prevent or delay the microvascular complications of diabetes, including retinopathy, nephropathy, and neuropathy. No prospective trial has clearly shown that glycemic intervention can prevent the macrovascular complications of diabetes, such as myocardial infarction, cerebrovascular accident, and amputation. However, a number of landmark clinical trials have shown the efficacy of control of blood pressure and lipids and use of antiplatelet agents (mainly aspirin) in protecting the macrovasculature of individuals with diabetes. In this article, glycemic, blood pressure, lipid, and antiplatelet trials relevant to the treatment of people with type 2 diabetes are reviewed.

Clinical Trials as Topic↗

PubMed2002

EtOH disrupts female mammalian puberty: age and opiate dependence.

The major drug of abuse among teenagers in the United States continues to be ethanol (EtOH), but use is seen in children as young as nine. In the studies reported here, the impact of EtOH on biologic and hormonal parameters of puberty was assessed in female rats. Rats were fed a liquid diet containing EtOH, pair fed an identical liquid diet containing dextrimaltose instead of EtOH, or fed a liquid diet not containing EtOH ad libitum. Feeding was started at 21, 25, or 28 d of age. EtOH markedly delayed the age at vaginal opening (34.5 +/- 0.5 d in controls vs 48.5 +/- 2.4 d in EtOH animals; p < 0.001), delayed the age at first estrous (40.9 +/- 0.6 d in controls vs 61.2 +/- 2.6 d in EtOH animals; p < 0.001), increased the length of the estrous cycle, and decreased the number of proestrous days. EtOH, concomitant with reduced ovarian and uterine weight, decreased serum estradiol and progesterone. Associated with these changes in ovarian hormones there was a selective increase in follicle-stimulating hormone, but not luteinizing hormone. EtOH consistently reduced insulin-like growth factor-1. In general, EtOH-induced disruption was more severe the younger the animals were at the start of feeding. Opiate receptor blockade with naltrexone completely prevented the EtOH-induced delay in vaginal opening. The impact of EtOH on female puberty is dramatic, is an emerging public health problem, and deserves more study.

Animals↗

PubMed2002

Alcohol's effects on female reproductive function.

Mild-to-moderate alcohol use has numerous negative consequences for female reproductive function. Animal studies have shown that alcohol consumption disrupts female puberty, and drinking during this period also may affect growth and bone health. Beyond puberty, alcohol has been found to disrupt normal menstrual cycling in female humans and animals and to affect hormonal levels in postmenopausal women. Research has explored the mechanisms of these effects and the implications of these effects for bone health.

Adolescent↗

PubMedDate not supplied

Hot flashes in patients with hypogonadism and low serum gonadotropin levels.

OBJECTIVE: To augment the number of cases in the literature describing patients with hot flashes due to hypopituitarism or hypothalamic hypogonadism. METHODS: We reviewed medical records for hot flashes in our patients with low sex hormone levels and low or inappropriately normal gonadotropin levels, and we inquired about hot flashes in new patients with these hormone patterns. A comprehensive literature review on this subject was also completed. RESULTS: In our medical records, we found 14 patients with hot flashes, low sex hormone levels, and low or inappropriately normal gonadotropin levels. In this group of patients, 10 had hypopituitarism and 6 had hypothalamic hypogonadism; 2 patients had both conditions. Hormone replacement therapy successfully relieved or substantially decreased the hot flashes in all 8 patients treated. A review of the literature revealed 17 patients with hot flashes and hypopituitarism and another 5 patients with hypothalamic hypogonadism. CONCLUSION: Hot flashes as a manifestation of low sex hormone levels and associated with low or inappropriately normal gonadotropin levels occur in patients with hypopituitarism and hypothalamic hypogonadism. Sex hormone replacement therapy alleviates the symptoms.

Female↗