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Biomedical subjects

E Cohen

Publications and source records attributed to E Cohen.

At least 145 records · Page 8Linked to original sources
PubMed1994

Damage awards and jurors' responsibility ascriptions in medical versus automobile negligence cases.

Many critics of the tort system have accused juries of assessing larger awards against defendants perceived to have the ability to pay. Juries are said to be particularly prone to go after the 'deep pockets' of doctors in medical malpractice cases as compared to defendants found negligent in automobile accidents. This hypothesis was put to a test in an experiment that manipulated cause of the injury (medical malpractice versus negligent driving) and degree of possible contributing responsibility by the plaintiff (mandatory versus elective surgery and plaintiff as another driver or as a passenger). Responsibility ascriptions to the plaintiff differed across conditions, but jurors did not differentially award pain and suffering damages across conditions.

Accidents, Traffic↗
PubMed1994

Short versus longer term effectiveness of an outreach program for the homeless mentally ill.

Presents 12-month follow-up results from an outreach/linkage intervention with persons who are homeless and mentally ill, contrasting these with results obtained at 4 months. Both sets reflect the success of the program in placing individuals in independent housing. However, longer term data provide useful information regarding client movement patterns and increased tenure in nonhomeless living arrangements beyond the termination of specialized services. Analyses of 12-month residential outcomes identified four variables as significant predictors: recruitment source, project service duration, CMH service duration, and client age. In contrast to 4-month predictors, variables reflecting baseline client functioning were no longer significantly related to outcome, suggesting that the positive effects of the intervention may take longer to achieve with some clients. Discussion focuses on the implications of these effectiveness results for future research designs and measures as well as the utility and limitations of preexperimental approaches for evaluating innovative service models when implementation and efficacy experiences are lacking.

Adult↗
PubMed1994

The effects of insurance benefits coverage on functional and psychosocial outcomes after spinal cord injury.

This retrospective study examined the effects of type of payor (ie, catastrophic, Medicaid, and private) and extent of benefits and independent living (IL) resources received on functional and psychosocial outcomes after spinal cord injury (SCI). One hundred seventy SCI persons with dates of injury from 1985 to 1990 and who were on average 4 years after their initial discharge from rehabilitation participated in the study. Benefits and resources received from discharge to 2 years post-injury in housing, transportation, personal care assistance (PCA), and equipment were assessed. Outcome variables included measures of psychological distress, self-esteem, and participation in physical and work/school activities. Extent of benefits received after SCI was found to be both a function of source of payor and of subject's neurological classification. While an effect of total benefits received could not be detected on SCI subjects post-discharge physical activity, and benefits paid by self only were associated with physical activity. Transportation benefits received and type of payor were positively associated with work/school outcomes. Younger subjects, sponsored by private payors, and with incomplete injuries were more likely to be working or going to school after SCI. Benefits and payor were also associated with psychological distress. Privately sponsored subjects were less distressed, whereas those sponsored by Medicaid were most distressed. Extent of benefits received was found to be inversely associated with distress and self-esteem. Persons with lower self-esteem received more postdischarge benefits, whereas those who paid for their own benefits and those who received communication equipment benefits paid by insurance, reported higher self-esteem. Implications for possible policy changes based on these results are discussed.

Activities of Daily Living↗
PubMed1994

Creation of the isolated bowel segment in animals by omentoenteropexy.

An isolated bowel segment (IBS) was created in rats and dogs by a two-stage procedure. Initial coaptation of the bowel segment to the omentum ("omentoenteropexy") is followed by division of its mesentery several weeks later. The viability of the segment is maintained by angiogenesis at the coaptation site. Neoformed blood vessels were shown by angiographic studies, and in a dog the IBS was used for esophageal interposition.

Anastomosis, Surgical↗
PubMed1994

Synthesis of novel inhibitors of the HIV-1 protease: difunctional enols of simple N-protected amino acids.

A series of enol HIV-1 protease inhibitors which show competitive inhibition and the structure-activity relationship study which led to the design of these compounds are reported. By systematically modifying simple amino acids, Boc-Phe enol and Boc-Tyr enol derivatives yield nanomolar Kiapp values (Kiapp = 0.485 microM and Kiapp = 0.425 microM, respectively). These enols are of low molecular weight (< 500 g/mol) and of non-peptidic nature. The enols are synthesized in a one step chemical synthesis and modifications to increase their potency could easily be performed. Boc-Phe enol and Boc-Tyr enol showed low inhibitory effect on pepsin, Kiapps of 23 and 149 microM, respectively, and Boc-Phe enol showed a Kiapp of 20 microM for cathepsin D. Neither of these two compounds inhibited renin (< 10% inhibition at 200 microM).

Amino Acids↗
PubMed1994

Demonstration by two-color flow cytometry that tyrosine kinase activity is required for down-modulation of the oncogenic neu receptor.

Expression of rat oncogenic neu receptor, p185T-neu (a growth factor receptor with constitutive tyrosine kinase activity), causes cells to become transformed. Treatment with anti-neu receptor monoclonal antibodies reverts the transformed phenotype by down-modulation of p185T-neu. Monoclonal antibody treatment of cells expressing normal neu receptor, p185C-neu (which lacks constitutive tyrosine kinase activity), does not result in down-modulation of p185C-neu. To understand further the role the biochemical activity of p185T-neu plays in transformation and endocytosis, we created a series of mutations in p185T-neu. We found that fibroblasts expressing the tyrosine kinase-defective mutants cannot form foci in culture, colonies in soft agar, or tumors in immunocompromised mice. To follow the antibody-induced endocytosis of neu receptors expressed in these transfectants, we developed a novel two-color flow cytometric assay and confirmed receptor localization by electron microscopy. Cells were treated with mAb7.16.4 over time. After 4 hr of antibody treatment, less than 50% of full-length p185T-neu and of mutant T691 remained on the cell surface, whereas internal expression of the neu receptors within these cells initially increased and then decreased to the original internal receptor level. In contrast, the level of kinase-deficient mutated neu receptors remaining on the cell surface initially decreased by 35%, but, after 4 hr of antibody treatment, the cell surface expression level returned to approximately the original level. Concurrently, fluctuations in expression levels were seen internally over time as well. These cell lines were also treated with gold-conjugated mAb7.16.4. Using electron microscopy, we consistently found the gold particles within multivesicular bodies of cell lines expressing full-length or mutated neu receptor. These data strongly suggest that the fate of the neu receptor, once internalized, is directed by its tyrosine kinase activity. When the kinase activity of the neu receptor is disrupted, the receptor is internalized but recycled to the cell surface, whereas neu receptors which have constitutive kinase activity are internalized and presumably degraded when engaged with anti-neu receptor mAb. Understanding the regulation of receptor endocytosis, degradation, and recycling will contribute to the development of novel therapeutic protocols to combat human malignancies, particularly those associated with the overexpression of the human homologue of the neu receptor, c-erbB2.

Animals↗
PubMed1994

Radiation tolerance of the transplanted liver. A histopathologic study in three cases.

Three patients with multifocal recurrence of hepatocellular carcinoma following liver transplantation received palliative irradiation. Hyperfractionated irradiation (150 cGy/fraction b.i.d.) was delivered in two cases to the entire liver using parallel opposed oblique portals to a total dose of 30 Gy. Conventional irradiation (180 cGy/fraction) totaling 45 Gy was administered to the liver hilus with concomitant infusional 5-fluorouracil chemotherapy in the third case. Clinicopathologic correlations were performed. At autopsy all patients had massive tumor burden within the liver. Veno-occlusive changes were observed in two patients 1 and 2 months following completion of conventional and hyperfractionated irradiation, respectively. Liver transplantation in these two patients had been performed 18 and 16 months prior to palliative hepatic irradiation. In the third patient, no veno-occlusive changes were pathologically observed at autopsy 1 month after completing hyperfractionated radiation, which was delivered 6 months following liver transplantation. No significant differences in prior immunosuppressive therapy were identified among patients. Veno-occlusive changes are not spared by hyperfractionated radiation. Transplanted livers exhibit responses to radiation similar to those normally observed.

Adult↗
PubMed1994

Ages of onset of psychiatric disorders in a community population of older adolescents.

OBJECTIVE: Ages of onset of psychiatric disorders, as well as the link between early onset and later psychosocial functioning, were examined in a community population of older adolescents. METHOD: Subjects were 386 adolescents who were participants in an ongoing 14-year longitudinal study. At age 18, lifetime diagnoses and ages of onset of major depression, phobias, post-traumatic stress disorder, and substance disorders were assessed using the NIMH Diagnostic Interview Schedule, Revised Version. Behavioral, emotional, and academic functioning in later adolescence were evaluated through self-report measures and school records. RESULTS: Almost one fourth of the adolescents met criteria for at least one disorder by age 14. Simple phobias emerged earliest (by early childhood), whereas for major depression and substance disorders the peak risk periods for onset were midadolescence. The early onset (by age 14) of disorders was associated with continued impairments in behavioral and emotional functioning in late adolescence (at age 18). Furthermore, the early onset of disorders, compared to later onset (ages 15 through 18), increased the risk for additional co-occurring disorders. CONCLUSIONS: The striking levels of early psychopathology and associated long-term deficits in functioning found in this community population underscore the need for programs of early intervention.

Adaptation, Psychological↗
PubMed1994

Excursion-volume relation of the right hemidiaphragm measured by ultrasonography and respiratory airflow measurements.

BACKGROUND: Although real time ultrasonography has been used in the last decade to record diaphragmatic motion, the relation between diaphragmatic excursion and different inspired volumes (VT) has not been assessed by ultrasound. METHODS: Ten normal subjects were studied in the supine posture. Diaphragmatic excursion and VT were assessed simultaneously by M mode ultrasonography and respiratory airflow measurements at different inspired volumes. Ultrasound recordings of the movement of the right hemidiaphragm were carried out in the longitudinal plane subcostally. The transducer was held in a fixed position by a frame, built especially to eliminate any artefactual movement caused by outward motion of the anterior abdominal wall on inspiration. RESULTS: Mean (SD) maximal diaphragmatic excursion recorded was 6.0 (0.7) cm. Inspired volumes ranged from 15(5%) to 87(10%) of the subjects' inspiratory capacity. A linear relation between diaphragmatic excursion and VT was found in all subjects (r = 0.976-0.995). The regression line had a slope of 1.66 (0.24) cm/l. This slope had no correlation with either the height (r = 0.007) or weight (r = 0.143) of the subjects. In five subjects in whom diaphragmatic excursion could be recorded at volumes near total lung capacity, the relation between diaphragmatic excursion and VT became alinear at very high lung volumes. CONCLUSIONS: The relation between diaphragmatic excursion and VT was linear between 15(5%) and 87(10%) of inspiratory capacity. Ultrasonography of the diaphragm is a simple technique that could be applied in the clinical investigation of patients with suspected abnormalities of diaphragmatic movement.

Adult↗
PubMed1994

Diaphragmatic movement in hemiplegic patients measured by ultrasonography.

BACKGROUND: It is known that automatic breathing is controlled by centres in the lower brain stem, whereas volitional breathing is controlled by the cerebral cortical centres. In hemiplegia, lesions above the brain stem result in paralysis of limb muscles. This study was performed to determine whether the diaphragm might also be affected in patients with hemiplegia. METHODS: Studies were performed in six normal control subjects and in eight patients with complete hemiplegia caused by a lesion above the brain stem, all with no known chest disease. Full lung function tests were performed. Diaphragmatic excursion and inspired volume (VT) were measured simultaneously by M mode ultrasonography and respiratory airflow measurements. Recordings of diaphragmatic excursion were performed on each side separately during volitional and automatic breathing at a similar range of VT. RESULTS: Lung function tests lay within the normal range in all the control subjects. In the hemiplegic patients mean (SD) vital capacity was 79 (18)% and residual volume was 123(30)% of predicted. Total lung capacity and functional residual capacity were in the normal range. In the control subjects no significant difference in diaphragmatic excursion was found between volitional and automatic breathing for the same range of inspired volume. By contrast, there was a significant decrease in diaphragmatic excursion during volitional breathing compared with automatic breathing on the affected side in four of the eight hemiplegic patients. CONCLUSIONS: In four of eight hemiplegic patients reduced diaphragmatic movement was present on the paralysed side during volitional inspiration when compared with automatic inspiration. The hemidiaphragm may be involved on the affected side in patients with hemiplegia.

Aged↗
PubMed1994

Increased thromboxane mediates the adverse renal effects of interleukin-2 in rats.

The capillary leak syndrome with decreased GFR and renal water and sodium retention after recombinant interleukin-2 (IL-2) administration may arise from endothelial activation via an increase in prostaglandin synthesis. This study was undertaken to better define the role of the prostaglandin system in the renal and metabolic effects of IL-2 administration in rats. The chronic administration of IL-2 (100,000 U/kg, thrice daily, ip) resulted in a significant increase in body weight, a decrease in GFR and in the urinary excretion of sodium and potassium, and an increase in the urinary excretion of thromboxane (TXB2). After combined IL-2 and low-dose indomethacin (1.7 mg/kg per day po), a significant decrease in body weight with normalization of GFR, of the urinary excretion of Na, and of urinary TXB2 was noted in animals receiving combined therapy as compared with those receiving IL-2 alone. In contrast, high-dose indomethacin administration (33.3 mg/kg po for the last 3 days of the study) was associated with a further decrease in GFR, enhancement of the sodium and potassium retention, and suppression of prostaglandin E2 excretion. The administration of the thromboxane receptor antagonist SQ 29548 in IL-2-treated rats led to a reversal of the fall in GFR induced by the lymphokine without significant changes in urinary sodium excretion. These results support the hypothesis that thromboxane is an important mediator of the renal and systemic effects of IL-2. These effects are reversed at least partly by low-dose indomethacin, which selectively suppresses thromboxane A2 (TXA2) synthesis, or by TXA2 receptor antagonism.

Animals↗
PubMed1994

Carotid endarterectomy for symptom-free stenosis: the patient's point of view.

Determining the indication for carotid endarterectomy in a given patient with a totally symptom-free internal carotid artery stenosis depends on objectively assessing the risk of non-operative versus operative treatment, as well as on the patient's attitude towards immediate versus long-term risk. In order to study patients' attitudes and preferences, four groups of subjects were asked to complete two questionnaires: the first examined people's perceived deterioration in their quality of life if they sustained a stroke of a defined severity. The second checked the attitude towards risk of operative versus non-operative treatment at different levels of an expected annual stroke rate without surgery. This preliminary study showed the feasibility of studying these subjective elements, and also pointed to problem areas in this type of research. The existence of individual as well as group differences in patients' values and preferences should be considered in the decision-making process.

Adult↗
PubMed1994

Surface expression of the HIV-1 envelope proteins in env gene-transfected CD4-positive human T cell clones: characterization and killing by an antibody-dependent cellular cytotoxic mechanism.

The env gene of the human immunodeficiency virus-type 1 (HIV-1) was transfected in CEM-nkr, a human lymphoid cell line of T lineage that is resistant to the activity of natural killer cells, and for the first time, transfected T cell clones were established that stably express gp160 intracellularly and gp120 on the surface as demonstrated by radioimmunoprecipitation as well as by indirect membrane immunofluorescence. The regulatory protein vpu was not detected by radioimmunoprecipitation in these clones. The surface expression of gp120 without vpu in these clones provides direct evidence that gp160 is processed and cleaved (without vpu) in CD4+ cells. The CD4 antigens of these cells coprecipitated gp160; interestingly, no reduction of the surface CD4 expression (detectable by flow cytometric analysis of membrane immunofluorescence with OKT4) in the transfected cells was observed. However, decreased reactivity of the transfected clones with OKT4A was observed. The gp120-expressing cells did not form syncytia on coculture with other CD4+ human cell lines. These observations suggest the binding of gp120 to the surface CD4 antigen of the transfected cells. The transfected cells retained their resistance to the activity of the natural killer cells but showed a significant (p < 0.05) lysis when they were preincubated with AIDS patients' serum containing anti-gp120/41 antibodies. Thus, the expressed gp120/41 in these cells made them susceptible to killing by an antibody-dependent cellular cytotoxicity (ADCC) mechanism. To our knowledge, these are the first reported CD4+ T cell lines that stably express HIV envelope proteins. These cell lines would be useful as targets in exploring gp120/41-specific immune responses, especially in conducting gp120/41-specific ADCC studies in HIV-infected or gp120/41 (gp160)-vaccinated individuals.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1994

Levels of circulating intercellular adhesion molecule 1 and E-selectin in serum and synovial fluid of juvenile chronic arthritis patients.

OBJECTIVE: To measure the levels of two adhesion molecules (AM), soluble intercellular adhesion molecule 1 (sICAM-1) and soluble E-selectin (sE-selectin), in serum and synovial fluid (SF) of patients with juvenile chronic arthritis (JCA). METHODS: Both soluble AM levels were tested, in serum and synovial fluid (SF) samples, with an enzyme-linked immunosorbent assay (ELISA) method. RESULTS: Serum levels of sICAM-1 and sE-selectin in JCA patients were not significantly different from those of a control group. Synovial fluid levels of sICAM-1, but not of sE-selectin, assayed significantly higher (p < 0.05) in JCA patients than in controls. Moreover SF levels of both molecules correlated negatively with disease duration, being higher in the earliest phases. No significant correlations were found between JCA sICAM-1 and sE-selectin levels and leukocyte count or ESR. CONCLUSIONS: These observations may signify a more important role of ICAM-1 than E-selectin in the migration of inflammatory cells into JCA SF. The negative correlation of both AMSF levels in JCA patients with disease duration could reflect a higher expression of ICAM-1 and E-selectin during the earliest phases of the disease.

Adolescent↗