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Biomedical subjects

A M Lawrence

Publications and source records attributed to A M Lawrence.

At least 181 records · Page 10Linked to original sources
PubMedDate not supplied

The effect of ethanol on prolactin release from pituitary cells in vitro.

Exposure to ethanol is recognized to cause reproductive impairment in man and animals. Since elevated levels of prolactin will interfere with normal functioning of the hypothalamic-pituitary-gonadal axis, and since ethanol has been shown by others to lead to increased prolactin secretion in vivo, the present in vitro study was undertaken to determine whether there is a direct effect of ethanol (ETOH) on prolactin release. Prolactin release from anterior pituitary cells maintained in monolayer culture and exposed to either no ethanol or media containing ethanol at concentrations of 50, 100, 200, or 400 mg% was measured at 1, 4, 24, 48, 72 hours in incubation. Ethanol added directly to pituitary cells stimulated prolactin release at all time points examined. Significant stimulation occurred with addition of low and mid-range ethanol concentrations (50-200 mg%); no augmented prolactin secretory response was seen with the highest ethanol concentration used (400 mg%). This pattern of response was maintained throughout the entire 72 hour incubation period. Thus, the effect of ethanol on prolactin secretion is mediated, at least in part, at the anterior pituitary level.

Animals↗
PubMedDate not supplied

Failure of in vitro ethanol to inhibit LHRH release from the hypothalamus.

The reproductive alterations induced by ethanol (ETOH) in the male rodent have been intensively investigated. Although gonadal effects are well characterized, the impact of ETOH on the hypothalamic peptide luteinizing hormone-releasing hormone (LHRH) has been less well defined. The releasability of hypothalamic LHRH in the presence of ETOH has not been directly studied. We report here that ETOH in concentrations of 50 mg% to 400 mg% failed to inhibit LHRH release in vitro.

Animals↗
PubMedDate not supplied

The effect of in vitro ethanol exposure on basal growth hormone secretion.

Suppressive effects of ethanol (ETOH) on in vivo serum growth hormone (GH) levels have been reported in both humans and animals. To determine whether this effect could be mediated directly at the pituitary level, we have designed a series of in vitro experiments utilizing pituitary cells from ETOH naive animals maintained in monolayer culture. We report that ETOH, in doses ranging from 50 to 400 mg%, caused a prompt and sustained reduction in basal GH secretion, as well as a significant fall in intracellular GH content. These data establish that the in vivo effects of ETOH on GH can be accounted for, at least in part, by a direct effect at the pituitary level, possibly due to reduced GH synthesis.

Animals↗
PubMedDate not supplied

Laryngeal stenosis in acromegaly: a possible cause of airway difficulties associated with anesthesia.

After difficult intubation in an acromegalic patient was encountered, 7 additional acromegalic patients were studied by measuring the cricoid width and anteroposterior diameter. Cricoid width and anteroposterior diameter were generally found to be narrower than in a group of normal patients. Such narrowing may explain airway problems encountered in acromegalic surgical patients.

Acromegaly↗
PubMedDate not supplied

Thyrotoxic hypokalemic periodic paralysis: six cases in non-Asian patients.

OBJECTIVE: To describe six cases of thyrotoxic hypokalemic periodic paralysis (THPP) in non-Asian men. METHODS: We present six cases of THPP, including clinical and laboratory findings, treatment, and outcome, and review the related literature. RESULTS: Hypokalemic periodic paralysis is a relatively common occurrence in Asian men with thyrotoxicosis; however, it is unusual in non-Asian patients with thyrotoxicosis. Among our six patients--four Caucasians, one African-American, and one Hispanic--the precipitating factors, initial manifestations, and clinical course varied. In general, treatment with 131 I or potassium eliminated the paralytic episodes. CONCLUSION: THPP needs to be distinguished from nonthyrotoxic hypokalemic periodic paralysis. Although THPP is unusual in non-Asian men, it must be recognized because of the severe and potentially fatal complications, which are reversible with potassium replacement and antithyroid therapy.

Journal Article↗
PubMedDate not supplied

Diabetic neuropathy, A review of clinical manifestations.

Diabetic neuropathy in some form or other afflicts a majority of patients with diabetes mellitus. Neuropathic disturbance of sensory, motor or autonomic nerves may occur singly or in combination. Cranial nerve and other mononeuropathies generally resolve spontaneously. Autonomic neuropathy which can result in orthostatic hypotension, gastroparesis diabeticorum, nocturnal diarrhea, atonic bladder and impotence, although chronic, may wax and wane in clinical severity. Neuritis, disesthesias and painful sensory neuritis may resolve with good diabetic control; on occasion, diphenylhydantoin has been of therapeutic benefit.

Adolescent↗
PubMedDate not supplied

Variation in plasma and urinary inorganic phosphate and pyrophosphate in normal subjects and in patients with acromegaly or osteoarthritis.

Plasma inorganic pyrophosphate (PPi) and inorganic orthophosphate (Pi) levels, urinary PPi and Pi excretion were measured every 2 h for a day in 4 normal subjects on a normal diet and again while fasting; 5 patients with osteoarthritis and 4 patients with acromegaly were also studied. Plasma Pi values were elevated at night in all subjects and were highest in the acromegalic patients. Mean plasma PPi was lower during fasting and correlated with Pi levels in all non-fasting subjects. Urinary Pi and PPi were strongly correlated; both were lower in fasting subjects. Food intake and the time of blood sampling are important biological variables that must be considered when interpreting plasma PPi levels.

Acromegaly↗