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Biomedical subjects

M A Epstein

Publications and source records attributed to M A Epstein.

188 records · Page 11Linked to original sources

Protection of cottontop tamarins against Epstein-Barr virus-induced malignant lymphoma by a prototype subunit vaccine.

Epstein-Barr (EB) virus is one of the five herpesviruses of man. Strong links between this agent and the chain of events causing two human cancers, endemic Burkitt's lymphoma and undifferentiated nasopharyngeal carcinoma, have long been evident (reviewed in ref. 1). Because of this, and because of the very high incidence of nasopharyngeal carcinoma in certain large populations, it was suggested in 1976 that a vaccine should be developed against EB virus to prevent infection and thereby reduce tumour incidence amongst those at risk. The virus-determined membrane antigen (MA) was proposed as immunogen because it was known to elicit naturally occurring virus-neutralizing antibodies in man and because analogous antigens had been shown to act as effective experimental vaccines for preventing the herpesvirus-induced lymphomas of Marek's disease in chickens. Progress has been achieved in defining, quantifying and preparing MA molecules, and in enhancing their immunogenicity; a sensitive assay for antibodies to MA has been elaborated. Here we report that isolated cell membranes expressing MA, or purified MA glycoprotein of relative molecular mass (Mr) 340,000 (gp340), have been used to vaccinate cottontop tamarins (Saguinus oedipus oedipus), and that animals receiving either preparation were protected against the effects of a 100% tumour-inducing challenge dose of EB virus.

Animals↗

QTc interval prolongation associated with citalopram overdose: a case report and literature review.

Citalopram is a member of the selective serotonin reuptake inhibitor class of antidepressants. In 1998, citalopram was approved by the US Food and Drug Administration for the treatment of major depression. Like the other selective serotonin reuptake inhibitors, citalopram enjoys a relatively benign side effect profile compared with the tricyclic antidepressants and the monoamine oxidase inhibitors. However, citalopram has been associated with electrocardiographic changes and seizures at doses greater than 600 mg per day. Fatalities have occurred with citalopram-only overdoses. We report the case of a healthy 21-year-old woman who developed QTc interval prolongation after ingestion of approximately 400 mg citalopram. We discuss the cardiac effects of citalopram, review previous cases of citalopram overdose, and discuss treatment recommendations.

Adult↗

Altered responsiveness during hyperventilation-induced EEG slowing: a non-epileptic phenomenon in normal children.

The relation between hyperventilation (HV)-induced high-amplitude rhythmical slowing (HIHARS) and altered responsiveness without generalized spike and wave activity has not been clearly defined. To test whether altered responsiveness is a nonspecific physiologic response rather than a symptom of generalized epilepsy, we assessed verbal recall ability and motor response testing in 12 healthy nonepileptic children (mean age 9.6 years). Both tasks were administered as a baseline before HV, during HV but before onset of EEG slowing, and during HIHARS. Verbal recall and motor responsiveness remained unchanged during baseline and HV before onset of slowing. During HIHARS, all children exhibited impaired verbal recall (p < 0.005) and 8 of 12 failed to respond to repeated auditory clicks (p < 0.005). Our findings indicate that in a normal setting, responsiveness may be impaired during HV in healthy nonepileptic children.

Acoustic Stimulation↗

Inhibition of rat mammary tumorigenesis by voluntary exercise.

In this study, the anti-promoting effect of voluntary (wheel) exercise on 7, 12-dimethylbenz(a)anthracene (DMBA)-induced mammary tumorigenesis was investigated. All rats were fed high fat diets (23% of calories as fat) to mimice the typical western diet. Two doses of DMBA were used to determine if the antipromoting effects of exercise were dependent on the strength of the initiating agent. In addition, tumor estrogen receptors were assayed to determined whether exercise, through an estrogen-suppressing mechanism, selects for estrogen receptor-negative tumors. Female Sprague-Dawley rats were fed a semi-purified 23% fat (corn oil) diet (AIN-76A) and, on day 50 of age administered DMBA by gavage at 5 or 10 mg/rat. Rats were then randomized into 4 groups (n = 30) as follows: 1) low DMBA/sedentary; 2) low DMBA/exercise; 3) high DMBA/-sedentary; and 4) high DMBA/exercise. Active rats were placed in wheel-cage units, which allowed voluntary access to an activity wheel for 133 (low DMBA) and 77 (high DMBA) days, respectively, Sedentary rats were placed in conventional cages. Both active groups exhibited significantly lower total tumor numbers than their sedentary controls: 75 vs 102 (low DMBA) (p < 0.05) and 90 vs 160 (high DMBA) (p < 0.001). Compared to sedentary controls, latency was significantly lengthened in the low but not the high DMBA active groups; multiplicity, in contrast, was significantly decreased in the high, but not the low DMBA exercised group. Exercise had no effect on overall tumor incidence. When segregated into exercise tertiles, total tumor active compared to the least active tertile, particularly in the high DMBA group.(ABSTRACT TRUNCATED AT 250 WORDS)

9,10-Dimethyl-1,2-benzanthracene↗