Biomedical subjects
J Feldman
Publications and source records attributed to J Feldman.
Pharmacological analysis of the central cardiovascular effects of four GABA analogues.
The central cardiovascular effects of 4 structural analogues of GABA were investigated. The drugs were injected intracerebroventricularly (i.c.v.) in cumulative doses into pentobarbital-anaesthetized normotensive rats. Muscimol (0.01-10 micrograms/kg), THIP (0.01-100 micrograms/kg), kojic amine (0.1-100 micrograms/kg) and isoguvacine (0.1-100 micrograms/kg) produced dose-dependent hypotension and bradycardia. The maximal fall in the mean blood pressure was of about 35% of the initial values. These effects appears to be of central origin since the intravenous (i.v.) injection of the same doses of the drugs did not produce any similar cardiovascular modifications. The hypotensive effects of muscimol and kojic amine were antagonized partly by i.c.v. bicuculline. The combination of bicuculline and kainic acid almost completely prevented the blood pressure lowering effects of muscimol, kojic amine and isoguvacine. THIP however was only slightly antagonized by bicuculline and kainic acid. Atropine i.v. also prevented partly the cardiovascular effects of all these drugs. Thus, the mechanisms of the central cardiovascular actions of GABA analogues appear to be more complex than expected and variable from one drug to another. The involvement of GABA receptors of the A and B types and of cholinergic mechanisms in the hypotensive effect of the drugs is discussed.
Central cardiovascular effects of alpha adrenergic drugs: differences between catecholamines and imidazolines.
To check whether the central hypotensive effect of alpha adrenergic agonists is linked with the stimulation of alpha-2 receptors, such drugs were administered directly to the nucleus reticularis lateralis, which is an important site for the hypotensive action of clonidine. These experiments were carried out by microinjections (0.5 microliter on each side) in normotensive cats anesthetized with pentobarbital. alpha-Methylnorepinephrine, a selective alpha-2 agonist (0.1-10 micrograms/kg) had no hypotensive effect in this region, whereas potent alpha-1 agonists such as cirazoline (0.01-1 micrograms/kg) and ST 587 (1-10 micrograms/kg), like clonidine, produced dose-dependent hypotensive effects. Our results suggest that alpha-2 selective catecholamines are not active in the nucleus reticularis lateralis region, whereas imidazolines induce a hypotensive effect whatever their affinity for one subtype of alpha adrenoceptors. Therefore, there may be some form of structure-activity relationship which would indicate the existence, in this particular region of the medulla oblongata, of sites preferring the imidazoline structure.
Living with DRGs.
Efforts to curb Medicare and health care costs have resulted in new systems of third-party reimbursements to hospitals. The authors examine how implementation of a new system in New Jersey is affecting nurses and nursing care in that state.
The New York State Tumor Registry. An important resource.
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Interpreting randomized trials.
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Reduction of asthenopia in patients with convergence insufficiency after fusional vergence training.
Seven patients with convergence insufficiency and related asthenopia underwent automated fusional convergence training. A matched-subjects control group crossover design was used to reduce placebo effects. All patients showed significant increases in vergence ranges with concurrent marked reduction of symptoms after training. All patients showed a flattening of and an increase in the base-out portion of their fixation disparity curve. Our results demonstrated the effectiveness of fusional vergence training in reducing asthenopia in these patients. Subsequent accommodation and vergence training using traditional orthoptic procedures yielded further reduction of asthenopia, as well as an increase in the base-out fusional range.
Sites required for position-effect regulation of mating-type information in yeast.
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Localization and sequence analysis of yeast origins of DNA replication.
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The neural generation of locomotion in the lamprey: an incomplete account.
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[Morphine antagonizes the central hypotensive effect of clonidine in the anesthetized cat].
A dose of 1 microgram/kg of clonidine injected intracerebroventricularly (I.C.V.) in the normotensive anaesthetized Cat elicits a significant and long lasting drop in the mean arterial blood pressure (23 +/- 5 mmHg) and the heart rate (34 +/- 5 beats/min.). A pretreatment with morphine (100 micrograms/kg, I.C.V.) completely prevents the central hypotensive effect of clonidine, whereas the bradycardia is only weakly influenced. Administered after clonidine, morphine reverses the hypotensive effect of clonidine whereas morphine does not affect its bradycardic action. These data demonstrate that morphine antagonizes the central hypotensive effect of clonidine.
Evidence for a neuromodulatory role of GABA at the first synapse of the baroreceptor reflex pathway. Effects of GABA derivatives injected into the NTS.
Microinjections of GABA and of the specific agonist of GABA receptors, muscimol, in the intermediate nucleus tractus solitarii (NTS) of pentobarbitone anaesthetized cats produced hypertension and tachycardia. The GABA receptor antagonist, bicuculline, had opposite effects and prevented those of muscimol. Therefore, a GABAergic system appears to modulate the cardiovascular regulation within the NTS. d,l-Baclofen also increased blood pressure and heart rate when injected into the same region, but this effect was not antagonized by bicuculline. The mechanism of this action of baclofen is discussed.
A 15-year followup of 646 schizophrenic outpatients.
The 15-year hospitalization course of 646 chronic schizophrenic outpatients treated between 1958 and 1963 was determined using records of the research clinic, the Kings County Psychiatric Hospital, and the New York State Department of Mental Hygiene. The cohort was heterogeneous with regard to previous history of hospitalization: 20.6 percent had never been hospitalized, 22.0 percent had experienced only crisis admissions, and 57.4 percent had experienced long-term psychiatric hospitalization. The results indicate that 58.8 percent were hospitalized subsequent to project entry. A relationship was observed between previous history and hospitalization and hospitalization during the followup period. Patients with no previous history of hospitalization was less likely to be hospitalized than patients with crisis admissions only, who in turn were less likely to be hospitalized than patients with a history of hospitalization in a long-term psychiatric treatment facility (39.1 percent vs. 53.5 percent vs. 67.9 percent; p less than .001). The implications of these findings for future followup studies are discussed.
Cardiovascular effects of intracerebroventricular injections of baclofen in the conscious rabbit.
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Use of extracorporeal ascites dialysis in combined hepatic and renal failure.
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Use of the amobarbital interview to determine appropriate behavior therapy.
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I-cell disease and its rehabilitation: case study.
I-cell disease is a rare inborn error of mucolipid metabolism that is characterized by generalized hypotonia, thick and tight skin, restriction of joint motion, coarse facial features, bony deformities, and an inability to stand or walk. A case was treated with gentle stretching, neurodevelopmental therapy, and strengthening exercises of both hip and knee extensor muscles. After this treatment the patient was able to ambulate with moderate support using bilateral long leg braces.