Mark Allan Berk

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BACKGROUND This double-blind, multicenter, placebo-controlled study determined the efficacy and safety of dofetilide in converting atrial fibrillation (AF) or atrial flutter (AFl) to sinus rhythm (SR) and maintaining SR for 1 year. METHODS AND RESULTS Patients with AF or AFl (n=325) were randomized to 125, 250, or 500 microgram dofetilide or placebo twice(More)
The incidence of spontaneously occurring premature labor in insulin-dependent diabetic pregnancies is unclear, because previous studies have been confounded by a high rate of iatrogenic prematurity. The purpose of this study was to determine, in a large population of insulin-dependent diabetic pregnant women, the rate of spontaneous occurrence of premature(More)
The purpose of the present study was to evaluate factors affecting the rate of macrosomia and related complications in a population of infants of insulin-dependent diabetic mothers. The following factors were hypothesized to be predisposing to macrosomia: increased maternal weight gain during gestation, increased number of births until infant No. 3, white(More)
We hypothesized that adrenergic mechanisms support the postabsorptive plasma glucose concentration, and prevent hypoglycemia when glucagon secretion is deficient. Accordingly, we assessed the impact of glucagon deficiency, produced by infusion of somatostatin with insulin, without and with pharmacologic alpha- and beta-adrenergic blockade on the(More)
To determine if the enhanced glycemic response to epinephrine in patients with insulin-dependent diabetes mellitus (IDDM) is the result of increased adrenergic sensitivity per se, increased glucagon secretion, decreased insulin secretion, or a combination of these, plasma epinephrine concentration-response curves were determined in insulin-infused(More)
From animal and in vitro studies, it has been suggested that high environmental glucose, ketone, or insulin concentrations and low glucose or insulin concentrations may be etiologic factors for congenital malformations (CMs) in infants of diabetic mothers (IDMs). Transplacental passage of antibody-bound insulin has been demonstrated in humans. Controversy(More)
In view of evidence, largely in animals, indicating effects of sex steroids on adrenergic receptors, we measured mononuclear leukocyte (MNL) beta 2-adrenergic receptors and adenylate cyclase sensitivity to stimulation by isoproterenol as well as platelet alpha 2-adrenergic receptors and sensitivity of sodium fluoride-stimulated adenylate cyclase to(More)
In previous studies, we reported a high rate of spontaneous abortions in insulin-dependent diabetic pregnancies. Abortions were associated with poor first-trimester glycemic control. We hypothesized that improvement of glycemic control from one pregnancy to the other would improve fetal outcome and that deterioration of glycemic control would increase the(More)
A 57-year-old schizoaffective disorder patient was placed on chlorpromazine because of its sedative properties and low profile for extrapyramidal side effects. After two years of treatment, the patient developed photosensitivity and blue-gray pigmentation of the skin of the face, neck and dorsum of hands. Significant pigment deposits were also observed in(More)