Biomedical subjects
Publications and source records attributed to I Cohen.
The association between dermatomyositis and malignancy is well documented. However, the association between dermatomyositis and Hodgkin's disease is very unusual, particularly in children, adolescents, and young adults. A MEDLINE search of the literature revealed only 13 previous cases.
From January 1, 1984 to April 30, 1990, 38 patients were surgically found to have an intraabdominal disease resembling epithelial ovarian cancer. This diagnosis was confirmed in 31 patients; the remaining 7 met the criteria of primary peritoneal papillary serous carcinoma. Five of these were diagnosed retrospectively and two during surgery. The mean age at diagnosis was 61.2 years. Tumor histology revealed papillary serous carcinoma in six and mixed (papillary serous and papillary clear cell carcinoma) in one patient. Optimal debulking was achieved in three of seven cases (42.8%). Cisplatin-based combination chemotherapy was administered to all in the study group. Complete response was obtained in four patients, with one surviving for 76 months. The median survival in these patients was 34.5 months (range 6-76 months). Currently, three patients with complete response are alive with clinically undetectable disease. CA-125 assays were available in three cases and blood levels corroborated the clinically determined status of the disease. Tumor steroid hormone receptor status was determined in one case and revealed low levels of estrogen and progesterone receptors. To the best of our knowledge, the usefulness of CA-125 in the diagnosis, management, follow-up, and determination of tumor steroid hormone receptor status, mixed papillary serous and clear cell subtype histological patterns for primary peritoneal papillary serous carcinoma are first described in this report. It seems that this neoplasm may be treated and followed up as in epithelial ovarian cancer, obtaining long-term survival; however, the biologic behavior and management problems of this relatively new entity deserve further clinical experience.
The high post-traumatic regenerative ability of fish central nervous system has been partially attributed to the hospitable nature of the surrounding non-neuronal cells and their appropriate response to injury. Uncovering the correlation between fish non-neuronal cell structure and behavior might yield a better understanding of what makes them supportive to axonal growth. Towards this goal, structural proteins expressed by fish non-neuronal cells need to be characterized. In the present study we isolated cDNA clones encoding fish intermediate filaments which are prominent structural proteins in astrocytes. Among the isolated clones, one was identified as fish vimentin and another was found identical to the cloned fish keratin 8. Results are discussed with respect to the use of these cDNAs for further understanding of fish non-neuronal cell plasticity.
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The effect of the two metal ions Zn+2 and Cd+2 on the viability and activity of Escherichia coli B bacteria was studied in experimental conditions. Addition of Cd+2 (0.05 ppm) to the incubation medium caused an inhibition of 16 h in the culture's growth. In similar conditions and concentrations, Zn+2 did not affect the bacterial growth. Only concentrations of 0.5 ppm Zn+2 and more caused growth inhibition of 6 h. Accumulation of the metal ions in the E. coli cells has shown that there is a linear relation between the concentrations of Zn+2 and Cd+2 in the cells and their concentrations in the culture media. On the other hand, a decrease in the Cd+2 accumulation was noticed when the concomitant Zn+2 concentrations were higher in the incubation media. Exposure of E. coli to various concentrations of these ions resulted in an increase of the total protein and the metal binding proteins amount in the cells. The activity of alkaline phosphatase was increased 4-fold in the presence of these ions. Separation of protein fractions revealed three protein fractions which contain Zn+2 with MWs of 80, 40, and 10 kD. Three Cd+2 binding proteins have been separated and their molecular weights were 75, 50, and 25 kD. The two high molecular weight proteins were able to bind Zn+2. Conclusions from these results may contribute to the understanding of events and processes in the natural environment.
This article details the first reported case of neonatal osteomyelitis caused by a nonhemolytic group B streptococcus. The identification of the organism was delayed due to the lack of hemolysis on blood agar plates. Therefore, the infant was treated with a more toxic regimen of antibiotics than would have otherwise been indicated. Successful treatment of this nonhemolytic group B streptococcal osteomyelitis included a combination of both parenteral and oral antibiotics. Proper identification of nonhemolytic streptococcal infections in the infant is essential to ensure safe and accurate antibiotic treatment.
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Pregnancy outcomes of 244 women, successfully treated with erythromycin ethylsuccinate for cervical chlamydial infection, were compared with those of 79 chlamydia-positive pregnant women, who failed to respond to treatment, and 244 chlamydia-free control women, who were not treated. The three groups were at high risk for infection with Chlamydia trachomatis. The frequencies of premature rupture of the membranes, premature contractions, and small-for-gestational-age infants were significantly lower in the successfully treated patients when compared with those of the chlamydia-positive patients, but were not significantly different when compared with those of the control patients. These data indicate that in a pregnant population at high risk for infection with C trachomatis, repeated prenatal chlamydial testing, plus successful erythromycin treatment, can significantly reduce certain adverse effects on pregnancy outcome.
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We have hypothesized that ligand-induced binding sites (LIBS), i.e. sites expressed on cell surface receptors only after ligand binding causes the receptor to change shape, mediate subsequent biological events. To test this hypothesis, we have raised monoclonal antibodies that preferentially react with an integrin (platelet glycoprotein (GP) IIb-IIIa) after it bind Arg-Gly-Asp-containing ligands. The 13 anti-LIBS antibodies obtained define at least three distinct GPIIb-IIIa epitopes; one of these epitopes is also expressed following occupancy of another integrin, the vitronectin receptor. Certain of these LIBSs appear to mediate functions, since the antibodies that define them inhibit GPIIb-IIIa-mediated fibrin clot contraction or platelet adhesion to collagen. Nevertheless, none of the anti-LIBS antibodies inhibit binding of the primary ligand, fibrinogen. These data indicate that LIBS may mediate distinct consequences of receptor occupancy.
Doppler ultrasonography of the middle cerebral artery was performed on 17 fetuses that were small for gestational age at the time of delivery. Results were compared with a group of 25 fetuses that had a normal weight for gestational age at the time of delivery. Despite a significant difference in fetal weight and systolic/diastolic ratio of the umbilical artery between the two groups, no difference was found in either the systolic/diastolic ratio or in the Pourcelot index of the middle cerebral artery. This may reflect a protective effect on the brain circulation in the small-for-gestational-age fetus.
Two cases of endometrial sarcoma that developed many years after exposure to unopposed exogenous and endogenous estrogens, with no previous pelvic irradiation, are described. The literature is reviewed and the possible effect of prolonged unopposed estrogen stimulation is suggested as an etiologic factor in such extremely rare conditions. These cases add additional support to the assumption that prolonged and excessive endogenous or exogenous unopposed estrogen stimulation of the uterus may increase the risk of endometrial sarcoma.
A study was undertaken to examine possible transplacental passage of Chlamydia trachomatis from pregnant women who were seropositive for chlamydia, but with no cervical C. trachomatis infection. Forty asymptomatic pregnant women, scheduled for diagnostic amniocentesis at 15-19 weeks of gestation, were tested for the presence of high serum IgA and IgG chlamydial specific antibodies and for cervical chlamydia infection. Five (12.5%) had both high serum IgA and IgG antibody levels and 10 (25%) had high serum IgG antibody levels. Overall, 15 (37.5%) had high serum chlamydia specific antibody levels (all were free of cervical chlamydial infection). The evaluation of the amniotic fluid specimens of these 15 seropositive pregnant women, who were free of cervical chlamydial infection, proved negative for direct C. trachomatis antigen detection and for chlamydial IgA and IgG specific antibodies. These negative results could be attributed to the lack of transplacental passage of C. trachomatis or to the antimicrobial activity of amniotic fluid against C. trachomatis, which has been previously described. The discrepancy between maternal infection and maternal serum antibody levels may suggest that the serologic test does not predict the presence of an antigen in the cervix.
A case control study was performed to examine possible morbidity associated with Chlamydia trachomatis in 15 pregnant women with idiopathic preterm premature rupture of the membranes (PROM; group A), and in two control groups, 35 healthy preterm pregnant women (group B), and 43 healthy pregnant women at term (group C). Serum C. trachomatis IgG and IgA specific antibodies were determined using the single serovar (L2) inclusion immunoperoxidase assay. There were no significant differences in the prevalence rate of elevated levels of chlamydia IgG specific antibodies (titer greater than or equal to 1:128) between pregnant women suffering from idiopathic preterm PROM, as compared to healthy preterm and term pregnant women (20, 28 and 26%, respectively). Nor were there any significant differences in the prevalence rate of elevated levels of chlamydia IgA specific antibodies (titer greater than or equal to 1:16) between pregnant women with idiopathic preterm PROM, as compared to healthy preterm and term pregnant women (20, 20 and 17%, respectively). These findings do not support the assumption that C. trachomatis may play role in preterm PROM.
We have investigated the actions of acetylcholine in the absence and presence of the beta-agonist isoproterenol in cardiac Purkinje fibers. beta-Agonists, like isoproterenol, increase the magnitude of the pacemaker current (If) in cardiac myocytes by shifting its activation voltage more positive on the voltage axis. We find that acetylcholine has no effect on If in the absence of isoproterenol. However, if If is first increased by beta-agonist stimulation, acetylcholine can then return If to control levels. This effect on If is exerted through muscarinic receptors since atropine prevents this action of acetylcholine. Functionally, this action of acetylcholine can guarantee the maintenance of ventricular pacemakers when there is high parasympathetic tone but can also prevent extra ventricular beats when sympathetic and parasympathetic tone are both high.