Biomedical subjects
Publications and source records attributed to A Levy.
Labeling and stigma in mental disorders occupy a central place in both mental health theory and practice. Some of the problems involved in making psychiatric diagnoses are reviewed. A case description is presented, demonstrating the dangers and complications of labeling and stigma. The irreversibility of labeling and stigma in psychiatric misdiagnosis is emphasized and discussed.
Autoxidation as a function of hemoglobin concentration indicates a 17-fold increase in the rate of autoxidation from 0.25 (%/h) to 4.3 (%/h) when tetrameric oxyhemoglobin dissociates into dimers. As a result of this large enhancement, a contribution of dissociation to the autoxidation is evident even at relatively high concentrations of hemoglobin for which it is usually considered that dissociation can be neglected. The mechanism for this phenomenon is attributed to alterations in the ligand pocket which occur when constraints due to subunit contacts within the R-state are eliminated.
Proneness to injury is a natural inclination with many causes: psychological, physical, physiological and social. We describe 9 patients with this problem. Most injuries, usually the result of falls, occur in 3 populations: young sports persons, workmen, and the elderly or those with chronic disorders. By analyzing the cases we can identify those prone to accidents and injury so as to improve prevention.
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Short-term psychiatric hospitalization, developed during the past 2 decades, needs thorough evaluation with regard to its advantages. It is important to be able to identify those patients who might be aided by such treatment. Therefore the psychiatric emergency room physician should have at hand a model which would enable quick and relatively accurate decisions in identifying such patients. Our work shows that they are either without previous psychiatric history or had been admitted for less than 2 months; that they had suffered from depression, anxiety, personality disorder or addiction; that they had a substantial support system; and that when they had been treated, there had been good compliance with prescribed medication. On the other hand, those who probably would not benefit from short-term psychiatric hospitalization had a history of psychiatric hospitalization of usually more than 2 months; were diagnosed as suffering from schizophrenia or affective disorder; lacked substantial family support; and had poor compliance with medication. This data may aid the physician during the initial interview in the psychiatric emergency room in deciding on further treatment. We also found that psychiatric emergency room diagnoses are usually reliable; and that those whose only diagnosis was "for observation" had a fair chance of a successful result after short-term hospitalization (discharge directly from the emergency room unit). We therefore presume that a sharper characterization of patients referred to the psychiatric emergency room may aid in tailoring the most suitable treatment for any particular patient, thus reserving short-term hospitalization only for those who would benefit the most.(ABSTRACT TRUNCATED AT 250 WORDS)
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High performance hydrophobic interaction chromatography has been used to separate progestin receptors (PRs) from human uterus and from the T47D human breast cancer cell line. Reproducible separations of high resolution were achieved using a TSK Phenyl-5PW column and a reverse salt gradient of 400 mM to 0 mM sodium sulfate in phosphate buffer, pH 7.4. Peaks of radioactivity exhibiting hydrophobic behaviour were isolated, as well as a smaller proportion of specific bound receptors located in the void volume fraction. No differences in retention times were observed between uterine and breast cell line samples. When the technique was used in conjunction with rapid vertical tube sucrose density gradient centrifugation, the 8S sedimenting PR from fresh, low-salt cytosol always eluted with a retention time of 24 min. The natural 4S receptor chromatographed as a single peak at 29 min while the 4S receptor species from high-salt cytosol appeared as two distinct peaks of radioactivity with retention times of 29 and 33 min. While specific binding was shown to occur in the void volume of the column, the origin of these receptors were indeterminate. These results would suggest that under these conditions the 8S receptor occurs as a single hydrophobic class of protein, whereas the data provides evidence that transformed 4S receptor may be proportioned into two unequal entities as a function of exposure to salt.
The data of the present study indicate that chrysotile induces the formation of a clastogenic factor (CF) when mesothelial cells are exposed to these fibers in vitro. Ultrafiltrates of culture media induce chromosome damage in human lymphocytes used as a test system for the detection of clastogenic activity in conditioned media. According to the cut off of the filters (10,000 dalton), CF is a small molecule. Its exact nature is unknown. The intermediacy of active oxygen species in CF formation is suggested by the anticlastogenic effect of antioxidant enzymes such as superoxide dismutase and catalase. The data are similar to those obtained with other membrane-active agents, in particular the tumor promoter tetra-decanoylphorbol acetate (TPA). The model of membrane-mediated chromosome damage with CF formation is proposed for asbestos-induced cell injury.
Ovarian cysts were diagnosed by antenatal ultrasonographic examination in 15 fetuses between 19 and 37 weeks' gestation. In six cases there was ultrasonographic evidence of torsion. Intracystic flocculation, which typically was deposited on the sloping part of the cyst, gave a characteristic liquid interface that was regarded as ultrasonographic evidence of torsion. All cases with evidence of torsion were managed surgically post partum, and in all patients this complication was confirmed. The remaining nine cases were followed up by repeated ultrasonograms, and in all patients disappearance of the cyst was documented within the first 6 months of life. The mean size of cysts with evidence of torsion was 5.41 +/- 0.25 cm, and the mean size of those without torsion was 4.33 +/- 0.3 cm (p less than 0.01). Histologic examination of the surgical specimen in the cases with evidence of torsion revealed follicular cysts in three cases and necrotic ovarian cysts with no specific epithelial findings in the remaining three. We recommend continuous ultrasonographic assessment of antenatally diagnosed cysts and believe that the choice of treatment depends on the appearance of the cyst and its evolution throughout pregnancy.
The calcium channel blocker nimodipine has been reported to improve cognitive performance in aged and brain-damaged animals. In the present study, the effects of nimodipine and placebo on spatial working memory and hippocampal acetylcholine were studied in young Fischer-344 rats. Nimodipine or placebo was administered via subcutaneously implanted, sustained-release pellets. Each active pellet contained 20 mg of nimodipine and released the drug over approximately 21 days. Two days after the drug or placebo pellets were implanted, training in the 8-arm radial maze started and continued for 12 days. Rats were required to learn a win-shift surgery. Nimodipine-treated animals learned the maze more rapidly than a placebo-treated group as indicated by the number of correct choices out of the first eight arms visited (p less than 0.001). Treated rats also made twice as many choices per unit time during the first week of training (p = 0.005). To assess hippocampal acetylcholine release, in vivo microdialysis was performed while animals were awake and unrestrained, 19-21 days after pellet implantation. A probe with a 3 mm semipermeable tip was placed in the hippocampus (CA1 and dentate gyrus), and individual microliters dialysate samples were collected at 2 microliters/min and immediately analyzed by high performance liquid chromatography with electrochemical detection. Significantly higher extracellular ACh levels were found in nimodipine-treated rats (71.4 +/- 3.6 nM; n = 4) compared to controls (52.5 +/- 2.5 nM; n = 5) (p = 0.003) and in another group of rats of the same age that received identical drug treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Extracellular levels of dopamine (DA) and its metabolites (DOPAC and HVA) were monitored in the striatum of rats using in vivo microdialysis, in an attempt to elucidate the mechanism of cyclo (His-Pro) (histidyl-proline-diketopiperazine, CHP) on dopaminergic activity. Pretreatment with CHP (0.5 mg/kg SC) (n = 5) or the equivalent volume of saline (n = 5) was followed 30 min later by 5 mg/kg IP of d-amphetamine. Dialysate samples were collected and analyzed by high performance liquid chromatography with electrochemical detection (HPLC-EC). Following the initial increase in DA caused by d-amphetamine, DA levels of CHP-treated rats were significantly lower than saline-treated rats across time (p less than 0.05). No difference was observed for DOPAC or HVA. It is therefore unlikely that CHP interferes with the d-amphetamine-induced inhibition of DA reuptake. Other neurotransmitter systems may be involved in the CHP-induced augmentation of amphetamine's behavioral effects. Our data, as well as previous findings, suggest that attenuation of the dopaminergic response to d-amphetamine might be best explained on the basis of striatal DA depletion, possibly via tyrosine hydroxylase (TH) inhibition. This study also indicates that a dissociation may exist between the behavioral and the striatal DA response to acute amphetamine. The data support the hypothesis that amphetamine releases DA from a newly synthesized, extravesicular cytoplasmic pool, and that intracellular striatal DA is present in considerable excess relative to the extracellular DA.
The validity of a modified version of the appropriateness evaluation protocol was assessed in a sample of patients aged 15 and over admitted by means of the emergency department of one of the Paris hospitals. As measured among 371 patients, the reliability of the indicator was high. The prevalence of inappropriate admissions (IA) was found to be 20% using the expert opinions and 25% the instrument. Homelessness was associated with a higher prevalence of IA (34%). Other social factors and age were not related to IA. According to the experts' opinions, difficulties in organizing the continuity of care for patients examined in the emergency room were one of the main causes for IA.
Superoxide is produced during the autoxidation of hemoglobin. Autoxidation of hemoglobin is, however, facilitated under hypoxic conditions where hemoglobin is only partially oxygenated. We have recently found that the erythrocyte superoxide dismutase does not fully react with the additional superoxide produced under hypoxic conditions. A leakage of superoxide from the erythrocyte is thus detected, resulting in a potential source for oxyradical damage to tissues. Detailed studies on intact erythrocytes as a function of oxygen pressure have now been performed. These studies further delineate the hypoxic stress on erythrocytes and the mechanism for the leakage of superoxide. By centrifugation of samples under various oxygen pressures it was possible to show an enhanced rate of lysis at reduced oxygen pressures with a maximum rate in the region of 25 mm Hg. At much lower pressures where the hemoglobin is mostly deoxygenated the rate of lysis was dramatically decreased with almost no lysis detected even after three days. Lysis is shown to be associated with superoxide membrane damage. The formation of superoxide which does not react with endogenous SOD reaches a maximum value at much lower pressures where most of the hemoglobin is deoxygenated. It is suggested that the leakage at low pressure is associated with the formation of superoxide by oxidation of hemoglobin associated with the membrane.
The concept of the professional historical mistake (PHM) pertains to a wide spread, deep seated, narrow professional attitude which has prevailed for many years, or decades, and fails to take into consideration existing professional knowledge, which would broaden the narrow professional approach. 3 cases of PHM in psychiatry are discussed. It is believed that PHM occur in medicine, and since they tend to be overlooked, conscious effort to detect them is needed in order to prevent or to halt them.
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