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Biomedical subjects

R S Surwit

Publications and source records attributed to R S Surwit.

At least 55 records · Page 3Linked to original sources
PubMed1989

Altered pituitary hormone response to naloxone in hypertension development.

Endogenous opioid regulation of blood pressure is altered during stress in young adults at risk for hypertension. We studied the effects of the opioid antagonist naloxone on the secretion of corticotropin and beta-endorphin during psychological stress in young adults with mildly elevated casual arterial pressures. Naloxone-induced secretion of both corticotropin and beta-endorphin was significantly diminished in persons at enhanced risk for hypertension compared with the low blood pressure control group. Results suggest that opioidergic inhibition of anterior pituitary function is altered in hypertension development.

Adolescent↗
PubMed1989

Muscarinic stimulation and antagonism and glucoregulation in nondiabetic and obese hyperglycemic mice.

Plasma glucose and insulin responses to a muscarinic agonist (bethanechol chloride) and a muscarinic antagonist (atropine) were evaluated in obese C57BL/6J ob/ob mice and in lean C57BL/6J + /? mice. In lean +/? mice, plasma glucose decreased in response to 1 and 2 micrograms/g bethanechol chloride, whereas insulin increased significantly. In ob/ob mice, insulin increased remarkably in response to bethanechol administration (saline, 632 +/- 80 microU/ml; 2 micrograms/g bethanechol chloride, 1794 +/- 97 microU/ml; n = 10), but surprisingly, plasma glucose also rose significantly (saline, 230 +/- 14 mg/dl; 2 micrograms/g bethanechol chloride, 363 +/- 18 mg/dl, n = 10). This exaggerated hyperglycemia in ob/ob mice was not associated with significant changes in plasma glucagon. Furthermore, administration of propranolol hydrochloride did not diminish bethanechol chloride-induced hyperglycemia in ob/ob mice. Administration of atropine (2.5, 5, and 10 mg/kg body wt) induced a significant decrease in plasma insulin without changes in plasma glucose in ob/ob mice, whereas neither plasma insulin nor plasma glucose changed in lean mice. Finally, conversion of [14C]alanine to glucose was increased in ob/ob mice after bethanechol chloride administration, indicating that muscarinic stimulation increases gluconeogenesis in an animal model of type II (non-insulin-dependent) diabetes.

Animals↗
PubMed1988

Diet-induced type II diabetes in C57BL/6J mice.

We investigated the effects of diet-induced obesity on glucose metabolism in two strains of mice, C57BL/6J and A/J. Twenty animals from each strain received ad libitum exposure to a high-fat high-simple-carbohydrate diet or standard Purina Rodent Chow for 6 mo. Exposure to the high-fat, high-simple-carbohydrate, low-fiber diet produced obesity in both A/J and C57BL/6J mice. Whereas obesity was associated with only moderate glucose intolerance and insulin resistance in A/J mice, obese C57BL/6J mice showed clear-cut diabetes with fasting blood glucose levels of greater than 240 mg/dl and blood insulin levels of greater than 150 microU/ml. C57BL/6J mice showed larger glycemic responses to stress and epinephrine in the lean state than AJ mice, and these responses were exaggerated by obesity. These data suggest that the C57BL/6J mouse carries a genetic predisposition to develop non-insulin-dependent (type II) diabetes. Furthermore, altered glycemic response to adrenergic stimulation may be a biologic marker for this genetic predisposition to develop type II diabetes.

Animals↗
PubMed1987

Exaggerated peripheral responses to catecholamines contributes to stress-induced hyperglycemia in the ob/ob mouse.

The present study investigated the contribution of altered sympathetic reactivity to the stress-induced hyperglycemia observed in the c57BL/6J (ob/ob) mouse, an animal model of type II diabetes. Blood glucose and insulin responses to sympathetic agonist and antagonist administration were evaluated in ob/ob mice and their nondiabetic, lean (ob/?) littermates. In addition, the ability of nutritional status to modify these responses was determined. These studies demonstrated that epinephrine administration to ob/ob mice caused an exaggerated increase in blood glucose and decrease in plasma insulin in ob/ob mice relative to lean littermates. The dose response curve for epinephrine-induced increases in blood glucose were shifted to the left, and the duration of the blood glucose and plasma insulin responses was longer. Differences between ob/ob mice and their nondiabetic littermates were greater when animals were tested in the fasted state. In addition, administration of the alpha adrenergic antagonist phentolamine caused a larger increase in plasma insulin in ob/ob mice than was observed in lean littermates. These results suggest that altered peripheral responses to sympathetic stimuli contribute to stress-induced hyperglycemia in ob/ob mice, and raise the possibility that altered sympathetic function is an etiologic factor in development of diabetes in these animals.

Adrenergic Fibers↗
PubMed1987

Failure of genetically selected miniature swine to model NIDDM.

Ten young adult miniature swine from a line reported to be genetically selected for glucose intolerance and eight normal controls were obtained from Colorado State University. They were consecutively exposed to 4 mo of a high-fiber, low-fat standard swine diet; 4 mo of a high-sucrose, high-fat, low-fiber diabetogenic diet; and 4 mo of excess diabetogenic diet for obesification. Results of oral glucose tolerance and intravenous insulin tolerance tests conducted at the end of each regimen were compared. Hyperglycemia was not observed in any animals after any manipulation. Insulin sensitivity was also not influenced by diet. We conclude that F7 low-K miniature swine from this colony fail to model human non-insulin-dependent diabetes.

Animals↗
PubMed1984

Biofeedback therapy of essential blepharospasm.

Eight patients with essential blepharospasm were given five consecutive sessions of electromyogram biofeedback from cutaneous electrodes placed over the frontalis muscle. Four of the eight patients demonstrated a 60% or greater reduction in blepharospasm frequency. Posttreatment electromyogram significantly predicted improvement of blepharospasm. These data suggest that electromyogram biofeedback may provide a therapeutic alternative to the treatment of this disabling condition.

Aged↗
PubMed1984

Behavioral manipulation of the diabetic phenotype in ob/ob mice.

The genetically obese mouse (C57BL/6J ob/ob) is a commonly used model of non-insulin-dependent diabetes mellitus. However, our studies demonstrate that, while the animal is significantly hyperinsulinemic, it in fact does not show consistent hyperglycemia in the resting state. During stress, both obese animals and their lean littermates become hyperglycemic, but the magnitude of the hyperglycemia is exaggerated in the obese mice. Obese animals also show an exaggerated plasma glucose increase in response to epinephrine injection. This increase in plasma glucose is accompanied by a decrease in plasma insulin in response to both stress and epinephrine. Our findings suggest that environmental stimuli influence the expression of diabetes in the C57BL/6J obese mouse and therefore must be considered in studies of this animal model of diabetes.

Animals↗
PubMed1984

A double-blind study of prazosin in the treatment of Raynaud's phenomenon in scleroderma.

Nineteen patients with Raynaud's phenomenon in conjunction with progressive systemic sclerosis were given either prazosin hydrochloride (1 mg orally three times a day) or a placebo for eight weeks, after which the treatment procedure was reversed for four weeks. Prazosin was shown to be effective in reducing both the frequency and the severity of vasospasm reported by the patients.

Adult↗
PubMed1983

Neuroendocrine response to cold in Raynaud's syndrome.

Eleven patients with Raynaud's syndrome accompanied by monospecific IgG ANA, nine patients with Raynaud's syndrome in the absence of ANA, and nine normal volunteers were exposed to an ambient cold challenge during which time venous blood was continuously sampled. ANA negative patients were shown to have significantly higher levels of cortisol during a cold challenge than either ANA positive patients or normal controls, and exhibited significantly lower levels of plasma norepinephrine compared with normal controls. ANA positive patients did not differ significantly from normals in their neuroendocrine response to cold. It is suggested that the high plasma cortisol found in Raynaud's syndrome in the absence of ANA may be responsible for the vasospasticity in this group of patients.

Antibodies, Antinuclear↗
PubMed1983

Intra-arterial reserpine for Raynaud's syndrome. Systemic reactions without therapeutic benefit.

Twenty-four patients classified as having Raynaud's disease or Raynaud's phenomenon were given bilateral brachial artery injections of reserpine or saline in a double-blind fashion. In the six weeks following injection, there was no indication that reserpine produced clinical improvement or changed vasomotor reactivity in the treated patients. However, intra-arterial reserpine did produce systemic cardiovascular effects lasting up to six weeks. It is concluded that intra-arterial reserpine as used in this study is an ineffective treatment for Raynaud's disease or Raynaud's phenomenon and may have significant adverse effects.

Adult↗
PubMed1981

Biofeedback techniques in the treatment of visual and ophthalmologic disorders: a review of the literature.

The literature on the use of biofeedback techniques in the treatment of visual and ophthalmologic disorders is reviewed. Although this consists mainly of case studies, there is mounting evidence that biofeedback may be applicable to the treatment of strabismus, nystagmus, blepharospasm, elevated intraocular pressure, and myopia. because of the success in applying biofeedback techniques in the treatment of other neuromuscular disorders, it is concluded that the use of these techniques in the treatment of blepharospasm and strabismus shows the most promise.

Biofeedback, Psychology↗
PubMed1981

Collagen vascular disease: can behavior therapy help?

This study examined the efficacy of a simple autogenic and biofeedback treatment package in the management of Raynaud's Phenomenon secondary to diagnosed collagen vascular disease. The patient, diagnosed as suffering from mixed connective tissue disease, had an average of 6.3 vasospastic attacks per day during a 2 week baseline period. The frequency of daily attacks dropped to 4.2 after 10 weeks and 2.5 attacks after 1 yr of training. In addition, the patient displayed a gradual improvement in the ability to maintain digital skin temperature in the presence of ambient cold stress.

Autogenic Training↗