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Biomedical subjects

J Feldman

Publications and source records attributed to J Feldman.

At least 109 records · Page 6Linked to original sources
PubMed1996

Comparative effects of idazoxan, prazosin, and yohimbine on coronary ligation-induced arrhythmias in spontaneously hypertensive rats.

We investigated whether certain drugs with alpha-adrenergic antagonist activity display anti-arrhythmic effects in hypertensive animals subjected to acute coronary artery ligation. The left anterior descending coronary artery (LAD) was ligated in open-chest pentobarbital-anesthetized spontaneously hypertensive rats (SHR); arrhythmias were subsequently recorded for 30 min. Drugs were administered intravenously, (i.v.) 5 min before ligation. The effects of yohimbine and idazoxan were compared with those of prazosin. Prazosin (100 mu g/kg) increased the occurrence of ventricular tachycardia (VT). In contrast, yohimbine 1.6 mg/kg decreased both the occurrence and the duration of VT and the occurrence and the duration of ventricular fibrillation, (VF). The results obtained with idazoxan 1 mg/kg were similar to those with yohimbine. The ECG alterations induced by coronary artery ligation in rats treated with yohimbine and idazoxan were more pronounced than in controls and in rats treated with prazosin, suggesting that the antiarrhythmic effects observed were not mediated by antiischemic activity. The protective effects against ligation-induced arrhythmias were preceded by a hypotensive effect and a decrease in the rate-pressure product in yohimbine-treated but not in idazoxan-treated animals. In rats treated with prazosin, more arrhythmic events were observed, although hemodynamics were similar to those in rats treated with yohimbine. Our results suggest that the yohimbine-induced antiarrhythmic action is not due to an alteration of conduction or repolarization rates. In this model, yohimbine and idazoxan appear to protect against ligation-induced arrhythmias. These data suggest that drugs with alpha-adrenergic properties might influence the nervous drive to the heart in SHR with cardiac ischemia. However, further investigations are needed to ascertain whether the alpha-adrenoceptor blockade participates in this effect.

Adrenergic alpha-Antagonists↗
PubMed1996

GABAergic and glutaminergic modulation of centrally evoked arrhythmias in rats.

A standard electrical stimulus applied to the posterior hypothalamus evoked cardiac arrhythmogenic responses in the spontaneously hypertensive rat. Isolated premature ventricular beats or doublets and nonsustained ventricular tachycardic salvos were observed. This effect was associated with a large rise in blood pressure (79 +/- 3 mm Hg). The same stimulus in normotensive Wistar-Kyoto rats produced no significant cardiac arrhythmias, and the rise in blood pressure was smaller (36 +/- 2 mm Hg). We investigated the influence of baclofen, a GABAB receptor agonist, and two N-methyl-D-aspartate receptor antagonists on the arrhythmogenic response to hypothalamic stimulation. Intravenous baclofen (3 mg/kg) had no effect in the normotensive Wistar-Kyoto rats, but in the spontaneously hypertensive rats it enhanced the adjusted mean value of the number of extrasystoles from 0.5 +/- 0.5 to 18 +/- 1 (P < .001). This value was also increased (from 3 +/- 1 to 17 +/- 1, P < .001) by an intracisternal injection of baclofen (1 micrograms/kg). This facilitatory effect of baclofen was prevented by treatment with atenolol (0.5 mg/kg). Two glutamate receptor antagonists, ketamine (7.5 mg/kg IV) and kynurenic acid (200 micrograms/kg intracerebroventricularly), prevented both the arrhythmogenic response to the hypothalamic stimulation and its facilitation by baclofen. The study confirms that hypothalamic stimulation facilitates the development of arrhythmias through a sympathetic drive and that these arrhythmias are easier to induce in spontaneously hypertensive rats than in normotensive Wistar-Kyoto rats. Both the central GABAergic and the glutamatergic systems are implicated in the development of these ventricular arrhythmias, since baclofen could disinhibit the glutamatergic central pathway. These results could account for the ability of the spontaneously hypertensive rats to develop ventricular arrhythmias of central origin.

Animals↗
PubMed1995

Increased genital shedding of herpes simplex virus type 2 in HIV-seropositive women.

OBJECTIVE: To compare the prevalence of genital herpes simplex virus type 2 (HSV-2) shedding in human immunodeficiency virus (HIV)-seropositive women and HIV-seronegative women. DESIGN: Cross-sectional study. SETTING: A major inner-city medical center. PATIENTS: 106 women who were HIV-seropositive and HSV-2-seropositive and 70 women who were HIV-seronegative and HSV-2-seropositive were enrolled from various primary care settings. MEASUREMENTS: Herpes simplex virus type 2 antibody determinations were done for all patients. Regardless of symptoms, vulvar and cervical HSV cultures were obtained from all HIV-seropositive women and from a randomly selected subgroup of HIV-seronegative women. RESULTS: The prevalence of HSV-2 shedding was nearly four times greater in HIV-seropositive than in HIV-seronegative women (13.2% compared with 3.6%; P = 0.04; odds ratio, 4.1 [95% CI, 1.0 to 27.4]) when the serum antibody for HSV-2 was present. Seventy-nine percent of viral shedding among HIV-seropositive women was asymptomatic. Overall viral shedding increased significantly as the CD4 cell count decreased. CONCLUSIONS: Women with HIV infection, particularly those with low CD4 cell counts, shed HSV-2 from the vulva and cervix more commonly than women not infected with HIV. Most of this shedding is asymptomatic.

CD4 Lymphocyte Count↗
PubMed1995

[Multiple myeloma: a geriatric dilemma].

Asymptomatic multiple myeloma was diagnosed in an 80-year-old woman with ischemic heart and cerebrovascular disease. The diagnosis was based on the finding of a rapid sedimentation rate (120 mm in the first hour), paraproteinemia with high levels of monoclonal IgA (4,582 mg%) and the characteristic findings on bone marrow aspiration. There was neither Bence-Jones protein nor hypercalcemia, nor clinical signs of multiple myeloma, such as bone pain, pathological fractures, or recurrent infections. We faced a dilemma in deciding whether or not to treat this elderly, asymptomatic woman. Chemotherapy in an elderly patient can be hazardous, and even life-threatening, due to adverse effects. On the other hand, untreated myeloma may be followed by rapid deterioration. It was decided not to start chemotherapy unless the clinical picture were to change for the worse. Although the hyperviscosity syndrome in this condition is usually due to elevated IgM paraprotein, it has been caused by IgG, or as in this case, by IgA hyperparaproteinemia.

Aged↗
PubMed1995

Evidence for a spinal origin of the effect of baclofen on the myocardial oxygen demand indexes.

In a previous study in anaesthetized rabbits we observed that electrical stimulation of the hypothalamic paraventricular nucleus (PVN) elicited substantial rises in the maximum rate of change of left ventricular pressure (dP/dtmax) and in myocardial oxygen demand indexes (rate-pressure product and triple product), similar to the changes observed during stress or physical effort. Baclofen, a selective GABA(B) receptor agonist, injected intravenously prevented these responses. In the present study, we show that low doses of baclofen (0.1, 0.3 and 1 microgram/kg), injected intrathecally (i.t.) at the T9 level, reduced the myocardial oxygen demand during PVN stimulation. After 0.3 microgram/kg baclofen i.t., the peak value of the triple product during stimulation was 140 +/- 20 compared with 193 +/- 20 before treatment. An i.t. injection (500 micrograms/kg), of saclofen a selective GABA(B) receptor antagonist, did not modify the resting haemodynamics significantly but attenuated the inhibitory effects of baclofen (3 mg/kg i.v.). These results suggest that the main site of the effects of baclofen is located within the spinal cord and that GABA(B) receptors probably mediate these effects by modulating the central control of cardiac function. In conclusion, baclofen might be a useful tool to prevent the centrally evoked increases of myocardial oxygen demand.

Animals↗
PubMed1995

The effect of recent cocaine use on the progress of labor.

OBJECTIVE: This study was undertaken to determine whether peripartum cocaine use shortens labor. STUDY DESIGN: A total of 1220 gravidas delivering at an urban county hospital (November 1991 through April 1992) had urine specimens sent for toxicology studies. Cervical dilatation on admission and time intervals during the course of labor were recorded. Analysis of covariance and exact tests for multiple contingency tables were used to compare duration of labor by cocaine use after we adjusted for other factors. RESULTS: Compared with nonusers, women who had positive test results for cocaine were older, were of greater parity, and were admitted to the hospital at greater cervical dilatation (4.63 cm vs 3.96 cm, p < 0.05). The duration of labor from admission to birth was also shorter (336 vs 565 minutes, p < 0.001). After we controlled for type of delivery, parity, birth weight, and prenatal care, there was no significant difference in labor duration in any stage. CONCLUSIONS: There is no difference in duration of any stage of labor related to cocaine use after patients' obstetric characteristics are controlled for.

Adult↗
PubMed1995

Bacterial vaginosis in lesbians: a sexually transmitted disease.

Sexual transmission of bacterial vaginosis (BV), a common syndrome in sexually active women, has not been previously established. Because no male counterpart for BV has been found, a population of lesbians is an ideal one in which to test the hypothesis that BV is sexually transmitted. We studied 103 homosexual women (lesbians) who sought gynecologic care at a community clinic and in a private gynecology practice in New York City. Participants were asked to refer their sexual partners for evaluation. In this cross-sectional prevalence study, all participants were evaluated for the presence of BV, and pairs of monogamous sexual partners were analyzed for concordance of their vaginal secretions. Twenty-nine (28.7%) of the 101 participants from whom satisfactory vaginal wash samples were available had BV. There were 21 pairs of monogamous partners. Of 11 index women who had BV, eight (72.7%) had partners who also had BV. Of 10 index women who did not have BV, only one (10%) had a partner with BV. The likelihood of a partner's having BV was 19.7 times greater if the index case had BV (P < .008; 95% CI, 2.1-588.0). We conclude that with respect to BV, lesbians in monogamous relationships usually have concordant vaginal secretions. This concordance probably reflects the sexual transmission of BV between lesbians.

Female↗
PubMed1995

Incidence of venereal warts in human immunodeficiency virus-infected and uninfected women.

A cohort of human immunodeficiency virus (HIV)-infected (n = 253) and uninfected (n = 658) women was prospectively studied to assess the relationship between venereal warts and HIV status, adjusting for self-reported and biologic measures of sexual risk behavior. Participants were assessed every 6 months for venereal warts and other sexually transmitted diseases, self-reported sexual behavior, and CD4 cell counts. The incidence of venereal warts was significantly increased in HIV-infected women (8.2 vs. 0.8/100 person-years of follow-up). This difference remained after adjusting for measures of high-risk sexual behavior and was observed in women at all levels of immune function, including those with > or = 500/mm3 CD4 cells. The increased risk of venereal warts in HIV infection can occur relatively early in HIV disease and appears chiefly attributable to a higher risk of progression from subclinical to clinical human papillomavirus (HPV) disease rather than to a higher risk of HPV acquisition.

Adult↗
PubMed1995

Developing visual and reading efficiency in older adults.

The authors hypothesized that adults, ages 62 to 75 years, who are in good health for their age can be trained to read more efficiently using approaches similar to those reported for younger individuals. Recruited successively from the State College of Optometry's primary care clinic, the subjects were 20 volunteers who had minimum corrected Snellen visual acuity of at least 6/9 (20/30) at distance and near, no oculomotor anomalies, and no significant ocular diseases such as diabetic retinitis. After a reading efficiency pretest using the Eye-trac, an infrared eye-movement recording device, the subjects were assigned to either a control group or a reading efficiency training group. Those in the control group were tested again after the control period. All subjects were retested after experimental intervention that consisted of rapid visual processing, oculomotor, and Guided Reading training. The results revealed a statistically significant and clinically meaningful improvement in all aspects of reading efficiency, including reduced number of fixations and regressions per 100 words, increased average span of recognition, and improved reading rate without loss of comprehension, only in those who received training. Our recommendation is that training in reading efficiency should be stressed to a greater extent in reading, educational, and vision therapy programs at all age levels.

Aged↗
PubMed1995

Inhibition of the centrally induced increases in myocardial oxygen demand in rabbits by chronic treatment with baclofen, a selective GABAB agonist.

1. A previous study from our group demonstrated that neurones of the paraventricular nucleus of the hypothalamus (PVN) are selectively involved in the central control of the cardiac function. Moreover, in that study, it was shown that baclofen, a selective GABAB receptor agonist, is capable of modulating the increases in myocardial contractility and oxygen demand evoked by electrical or pharmacological stimulation of the PVN. Nevertheless, the acute administration of this compound was frequently accompanied by a cardiodepressant effect. 2. In the present study, the effects of a long term treatment (14 days) with baclofen (3 or 10 mg kg-1, i.p.) have been examined on the excitatory haemodynamic responses evoked by central pharmacological stimulation in anaesthetized rabbits. 3. The i.c.v. injection of L-glutamate (3 mg kg-1) induced marked increases in dP/dtmax (32%), mean arterial pressure (39%) and on two indices of myocardial oxygen consumption: the rate-pressure product (34%) and the triple product (78%). 4. Baclofen blunted the positive inotropic response and the increases in myocardial oxygen consumption induced by L-glutamate in a dose-related manner. The higher dose of baclofen (10 mg kg-1, i.p.), reduced by more than 50% these excitatory effects of L-glutamate without eliciting any significant negative effect on basal haemodynamics. The same doses of baclofen were not able to blunt the hypertensive response induced by central stimulation. 5. These results confirm and extend our previous findings suggesting that it is possible to discriminate the central control of vasomotor tone from that of cardiac function and also that baclofen can modulate the latter. It is concluded that when given chronically, baclofen modulates the increases in myocardial oxygen demand induced by activation of the central nervous system in doses which do not depress the resting cardiac function.

Animals↗
PubMed1995

Polling patients with self-administered surveys.

After this paper describes how various forms of the self-administered survey can affect response to patient surveys, it compares survey response to two patient surveys-one conducted in a waiting room and the other conducted by mail. The waiting room survey produced a higher rate and speed of response, and resulted in more respondents with favorable attitudes toward the medical facility and the survey.

California↗
PubMed1995

Changes in perinatal cocaine use in an inner-city hospital, 1988 to 1992.

Temporal trends in perinatal drug use among parturients at an inner-city hospital were assessed in a cohort study of 1300 parturients in 1991 through 1992 and 1111 parturients in 1988 through 1989. Toxicology results were coupled to data sheets containing demographic and obstetrical information. A decrease was noted between 1988 and 1992 in the prevalence of cocaine metabolites, independent of the utilization of prenatal services. An increase in marijuana use and no change in opiate use were seen. When adjusted for ethnicity and receipt of care, a 50% decline in the odds ratio (OR) of cocaine use was noted between 1988 and 1992 (OR = 0.55; 95% confidence interval = 0.39, 0.79).

Cocaine↗
PubMed1995

Peer review of mammography interpretations in a breast cancer screening program.

Mammograms from a statewide screening program were subjected to a blind review by a panel of expert mammographers. Ninety-five percent (173/182) of original normal mammograms and 53% (164/311) of original abnormal mammograms were reread as normal. In comparison with the expert panel community radiologists were more likely to request a repeat mammogram in 6 months than to interpret a mammogram as normal or address their uncertainty with an immediate diagnostic workup.

Breast Neoplasms↗