Biomedical subjects
Publications and source records attributed to L Cohen.
A patient with brachial plexitis associated with disseminated gonococcal infection is presented. This is, to the best of our knowledge, the first case to be reported of this association.
Peripheral lymphadenopathy is rarely observed, whereas mesenteric lymphadenopathy is found occasionally on laparotomies in patients with familial Mediterranean fever (FMF). Retroperitoneal lymphadenopathy was reported only once in an autopsy of a patient with FMF. Our case is the second one, and the first one to be diagnosed during life, by means of abdominal ultrasonography and computerized tomography. In patients with FMF, where lymph node biopsy was done, the pathological finding was non-specific lymphoid hyperplasia.
We studied the effects of hyperbaric oxygen in a severe model of circulatory shock induced by occlusion and reperfusion of major splanchnic arteries (splanchnic artery occlusion (SAO) shock). Pentobarbital-anesthetized rats subjected to total occlusion of the superior mesenteric and the celiac arteries for 40 min developed a severe shock state, resulting in a uniformly fatal outcome after release of the occlusion. Exposure to hyperbaric oxygen at 2 ATA (atmosphere absolute) (1 ATA = 0.1 MPa) was initiated immediately after reperfusion. SAO shock rats exposed to hyperbaric oxygen maintained mean arterial blood pressure at significantly higher values throughout the postreperfusion period compared with untreated SAO shock rats (p less than 0.01), with final mean arterial blood pressures of 88 +/- 9 and 51 +/- 4 mmHg, respectively. Treatment with hyperbaric oxygen attenuated the increase in plasma activities of the lysosomal hydrolase cathepsin D (p less than 0.05), and diminished the increase of hematocrit (p less than 0.01 from untreated shock rats). Splanchnic occlusion shock rats treated with hyperbaric oxygen also exhibited a significantly higher survival rate than the untreated shock group (77 vs. 0%, respectively; p less than 0.01). Our results suggest that the beneficial effects of exposure to hyperbaric oxygen immediately after reperfusion of the splanchnic region outweigh its possible deleterious effect.
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Optical monitoring methods have reached the level of development where activity from a network of cells can be recorded in a minimally-dissected behaving animal. The spike activity in the buccal ganglion of Navanax was monitored during feeding and activity in the Aplysia abdominal ganglion was monitored during the gill-withdrawal reflex. Approximately 30 neurons in the Navanax buccal ganglion were active during feeding and between 250 and 400 neurons in the Aplysia abdominal ganglion were active during the gill-withdrawal reflex. A reasonably complete understanding of the neuronal basis of the gill withdrawal may not be possible with presently available scientific methods. Substantial improvements in signal-to-noise ratio in optical measurements will be necessary before the majority of synaptic potentials can be detected optically. Understanding circuits that involve more than a few neurons will be a challenge to neurobiologists.
Early afterdepolarization (EAD)-induced triggered activity is thought to contribute to the cardiac arrhythmogenic effects of several class I antiarrhythmic agents. The combination of quinidine therapy, bradycardia, and hypokalemia is known to predispose to torsade de pointes, which is a form of atypical polymorphous ventricular tachycardia commonly associated with long QT intervals. Recent clinical reports have shown suppression of quinidine-induced torsade de pointes with intravenous administration of magnesium sulfate. To provide further understanding of these relations, we used standard microelectrode techniques to examine the time course of quinidine-induced action potential prolongation, EAD, and triggered activity development and the dependence of these changes on [K+]0, [Mg2+]0, and stimulation frequency in isolated Purkinje fiber preparations exposed to low concentrations of the drug. At slow stimulation rates, the quinidine-induced increase of action potential duration was slow to develop and failed to reach a steady state after 3 hours of exposure to the drug. EAD and EAD-induced triggered activity generally became apparent 70-90 minutes after adding the drug. Quinidine produced triggered activity in 10 of 22 preparations superfused with Tyrode's solution containing normal [K+]0 (3.5-4.0 mM) and in six other preparations when [K+]0 was reduced. In the presence of normal [K+]0, two types of EAD and triggered activity were distinguished. In four of 10 preparations, this activity arose from phase 2 of the action potential; in eight of 10, it was associated with phase 3; and in two experiments, both types were present in the same preparation. The incidence of both forms of triggered responses depended greatly on the rate of stimulation. Triggered activity arising from phase 3 was always manifest at rates considerably slower than those giving rise to phase 2 activity. Both forms of triggered activity were sensitive to changes in the extracellular concentration of potassium and magnesium. Lower-than-normal levels of these electrolytes facilitated the manifestation of triggered activity, whereas elevated levels suppressed or caused a shift in the frequency-dependence of the activity. Phase 2, but not phase 3, EADs were abolished in response to increased [Mg2+]0. The data show a clear congruity between the conditions that predispose to torsade de pointes in the clinic and the conditions under which quinidine may induce triggered activity and marked action potential prolongation in isolated Purkinje fibers.(ABSTRACT TRUNCATED AT 400 WORDS)
The purpose of this report is to document the current status of the teaching of pit and fissure sealants in British dental schools. Survey responses were received from 88.9 per cent of the surveyed programmes, 87.5 per cent of surveyed staff and 77.8 per cent of surveyed dental schools representing 52.4 per cent of all surveyed students. All schools were providing instruction on pit and fissure sealants with departments of Child Dental Health having primary responsibility for teaching at most of them. Students estimated that 61.3 per cent of their child patients were receiving sealants. Staff and students gave both classroom and clinical sealant training favourable ratings. Similarly, the majority of staff and student respondents perceived that other staff and students considered sealants to be of value. Staff knowledge of sealants was generally accurate, while students displayed a larger percentage of incorrect or unsure responses. Both staff and students expressed generally positive attitudes toward sealants. Both groups also gave favourable ratings to the overall preventive orientation of their schools. The student's projected sealant use in practice was explained best by the combination of student attitudes toward sealants and their evaluation of the overall preventive orientation of their dental school.
Seventeen outpatients with panic anxiety and agoraphobia were treated with a low, flexible dose of clomipramine in an 8-week open trial. Panic attacks ceased completely in 13 patients and markedly decreased in the other four without additional therapeutic measures. Avoidance behavior disappeared in five of the seven agoraphobic patients. Overall mean dosage was 45 mg/day, with eight patients receiving clomipramine 25 mg or less. Higher doses were needed when agoraphobia was present. These results are discussed in conjunction with previous findings and lend support to serotonergic involvement in panic anxiety. Further double-blind studies are needed to confirm these results.
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The rheumatic manifestations of familial hypercholesterolemia include recurrent Achilles pain or tendinitis, acute mono/oligoarthritis and migratory (rheumatic fever-like) polyarthritis. Diagnosis is made by finding skin and tendon xanthomas, hypercholesterolemia, and ruling out other rheumatic conditions such as rheumatic fever, gout, pseudogout and septic arthritis. A patient, homozygous for familial hypercholesterolemia, with a rheumatic fever-like migratory arthritis is presented.
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