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Biomedical subjects

S G Terra

Publications and source records attributed to S G Terra.

7 recordsLinked to original sources

Association between beta-adrenergic receptor polymorphisms and their G-protein-coupled receptors with body mass index and obesity in women: a report from the NHLBI-sponsored WISE study.

OBJECTIVES: The beta-adrenergic receptor (betaAR) genes are candidate genes for obesity because of their roles in energy homeostasis and promotion of lipolysis in human adipose tissue. Objective is to determine the association between obesity and polymorphisms in genes of the beta(1)AR (ADRB1), beta(2)AR (ADRB2), beta(3)AR (ADRB3), Gs protein alpha (GNAS1), to which all three beta-receptors couple and the G protein beta3 subunit (GNB3), to which beta(3)ARs couple. DESIGN: A case-control genetic association study. SUBJECTS: A total of 643 black or white women enrolled in Women's Ischemia Syndrome Evaluation (WISE) study. MEASUREMENTS: Genotypes were determined by PCR with single primer extension. Associations between genotype and body mass index (BMI), waist-to-hip ratio (WHR), waist circumference, and obesity were made. RESULTS: Polymorphisms in the three betaAR genes, GNAS1, and GNB3 were not associated with BMI, WHR, waist circumference, or obesity. Linear and logistic regression analyses found no contribution of either genotype or haplotype with anthropometric measurements or obesity. CONCLUSIONS: Our study suggests that among American women with suspected coronary heart disease, polymorphisms in the betaARs and their G-protein-coupled receptors do not contribute to increased BMI, WHR, waist circumference, or obesity. Given that 50% of all women die from coronary heart disease, and a higher percentage have heart disease during their lifetime, our results are likely generalizable to many American women.

Adipose Tissue↗

Therapeutic range of digoxin's efficacy in heart failure: what is the evidence?

Clinical studies have solidified the utility of digoxin in patients with left ventricular dysfunction and normal sinus rhythm. No definitive data have been published to clarify the range of serum digoxin concentrations associated with clinical benefit. The traditional therapeutic range of 0.8-2.0 ng/ml was developed originally to classify digoxin toxicity, not efficacy. In addition, this reference range was used before publication of the Digitalis Investigators Group trial. Clinical and neurohormonal studies have attempted to characterize serum concentrations that are associated with clinical efficacy.

Cardiotonic Agents↗

Opioid antagonists in the treatment of pruritus from cholestatic liver disease.

The theory that pruritus from cholestasis is due to increased opiate tone appears to have merit, based on the results of the clinical trials presented above. However, although opioid antagonists relieve itching to a large extent, the itching usually is not abolished completely. Several factors may explain this lack of complete relief. The doses used in the clinical trials may have been insufficient, or duration of therapy may have been short. It is also possible that nonopioid mechanisms contribute to pruritus from cholestasis. Although effective, naloxone therapy has several limitations for long-term use, including a short half-life and large first-pass metabolism, which necessitates parenteral administration. Intravenous administration is clearly not practical for a chronic disease. Nalmefene treatment has several advantages over naloxone, with both prolonged duration of action and increased potency at the opioid receptor level. However, nalmefene is available only as a parenteral product in the US. The nalmefene studies are limited by their small sample size and short follow-up periods. Additionally, two of the studies are available in abstract form only. Based on two clinical studies, naltrexone therapy appears promising. Gradual dose titration from 25 mg/d up to a maximum of 50 mg/d may minimize withdrawal reactions. Further long-term clinical trials using objective measures that compare opioid antagonists with other therapies are needed to clearly establish the role of these agents. Potential tachyphylaxis from long-term use of opioid antagonists requires further investigation. Combination therapy may also be required, since monotherapy with either opioid antagonists or other therapies have failed to completely relieve the pruritus caused by cholestasis. Given the potential for severe withdrawal reactions, opioid antagonists should be reserved for patients refractory to other treatments.

Cholestasis↗

Medroxyprogesterone acetate in the treatment of obstructive sleep apnea.

The use of MPA in patients with OSA is limited. Instead, patients with OSA should be encouraged to abstain from alcohol and respiratory depressive agents, and avoid sleeping in the supine position. In general, patients with OSA are most effectively treated with CPAP and/or surgery. Patients need to be encouraged to maintain ideal body weight, since this has been associated with a marked reduction in symptoms. For patients who are not surgical candidates or refuse to use CPAP, drug therapy may be beneficial. Fluoxetine has been shown to be as effective as protriptyline, and is better tolerated. However, further study is needed to determine whether selective serotonin-reuptake inhibitors are beneficial in treating OSA. Therefore, MPA therapy should be reserved for hypercapnic patients who refuse other modalities of treatment. The potential long-term adverse effects of MPA must be addressed before initiating therapy in men with OSA.

Humans↗

A review of tissue plasminogen activator in the treatment of veno-occlusive liver disease after bone marrow transplantation.

Veno-occlusive disease (VOD) of the liver is a potentially life-threatening complication that usually occurs secondary to high dose-chemotherapy with or without total body irradiation as preparative therapy for bone marrow transplantation. The key event in the development of VOD is damage to the vascular endothelium in the liver, which produces a hypercoagulable state triggering the clotting cascade. Factor VIII and fibrinogen are deposited in the hepatic venules, leading to obliteration of the venules. Tissue plasminogen activator (t-PA) converts fibrin-bound plasminogen to plasmin, thereby producing clot lysis. Review of the literature suggests that t-PA can be administered safely, with some limitations, for the treatment of VOD.

Bone Marrow Transplantation↗