Human choriogonadotropin-induced coupling of receptor and Gs protein and the effect of hormone deglycosylation

The detergent-soluble extract of rat ovary plasma membranes contained a Gs protein of about 100 kDa as shown by its elution behavior on a Bio Gel A-1.5m column. However, the cell membranes exposed to hCG (37° C, 15 min) contained in addition a higher molecular weight Gs protein complex of 300 kDa comprised of human chorionic gonadotropin (hCG) receptor (hCGR) and Gs. The complex bound with an affinity column of GTP-Sepharose and could be released with Gpp(NH)p and GTP inhibited this binding. The presence of the hCGR in the complex was shown by its binding to ¹²⁵I-hCG. Furthermore, GTP inhibited the binding of hCG to the complex. These results indicate the presence of hCGR and Gs protein complex in the hCG-treated membranes. hCGR and Gs protein were individually purified and reconstituted into phospholipid vesicles. The protein-phospholipid vesicles showed saturation kinetics of binding of ¹²⁵I-hCG and ³H-Gpp(NH)p. Incubation of phospholipid vesicles with hCG resulted in a 2–3-fold increase in the binding of ³H-Gpp(NH)p and GTPase activity. Activation of Gs protein was dependent on the length of incubation and the hormone concentration. Deglycosylated hCG was about 10 times less potent than hCG suggesting a role of carbohydrates of hCG in inducing hCG-Gs protein interactions. The data with the in vitro reconstitution system rule out the involvement of a carbohydrate-binding lectin in the function of the hormone.     

Utility of voice therapy in the management of vocal fold polyps and cysts.

OBJECTIVE: To evaluate the efficacy of voice therapy in the management of vocal fold polyps and cysts. STUDY DESIGN AND SETTING: Retrospective review of vocal fold cysts and polyps undergoing voice therapy in a tertiary care center. Symptom resolution or persistence resulting in surgical intervention was the main outcome measure. RESULTS: Fifty-seven patients were identified, of which 49.1% achieved symptom resolution with voice therapy alone. Patients with complete glottal closure and muscle tension dysphonia did not have a better response than those with incomplete glottal closure and without muscle tension dysphonia (P = 0.1, chi(2), respectively). Patients with translucent polyps more commonly responded to voice therapy than fibrotic, hyaline, or hemorrhagic polyps, 81.8% versus 15.4% and 25.0% response rate, respectively (P = 0.002, chi(2)). CONCLUSIONS: Voice therapy is an effective treatment modality for vocal fold polyps and cysts. SIGNIFICANCE: A multidisciplinary approach including a trial of voice therapy is warranted.     

Prevention of sexually transmitted HIV infection: A meta-analytic review of teh behavioral outcome literature

Social learning theory-based models have recently provided the foundation for a series of twelve controlled human immunodeficiency virus (HIV) risk reduction intervention studies that have examined sexual behavior change. These interventions have been tested with adolescents, gay and bisexual men, inner-city women, college students, and seriously mentally ill adults. We report the first meta-analysis of these intervention studies. We found that, as expected, the mean weighted effect of HIV-risk reduction interventions on behavioral outcomes was positive and strongly significant (d₊=0.25). Moreover, the studies’ effect sizes were consistently positive, ranging from 0.11 to 0.53, and were largest when the outcomes were measured close in time to the intervention. We discuss other methodological challenges that, if solved, should enhance the success of future HIV-risk reduction interventions.     

Medication Outcome in ECT-Resistant Depression

The outcome of antidepressant treatment in 12 cases of electroconvulsive therapy (ECT)-resistant depression is presented. Eight patients had been refractory to a clinically adequate course of ECT (Hamilton Depression Scale improvement <20%) and four were partial responders (improvement 20-49%). All remitted completely on antidepressant medication within 2.2 +/- 1.1 (mean +/- SD) months of the ECT course. Remission was associated with clomipramine treatment (139 +/- 49.7 mg/day) in seven cases and maprotiline (125 mg/day) in one case. Four patients who did not respond to a tricyclic antidepressant alone remitted following supplementation (of clomipramine in 2 cases, clomipramine + haloperidol in 1 case, and imipramine in 1 case) with lithium carbonate. Although a delayed therapeutic response to ECT cannot be excluded, the results suggest that ECT may alter the sensitivity of refractory patients to antidepressant medication.     

Monoclonal anti-(T,G)-A—L antibodies: Characterization of fine specificity and idiotype expression

The technique of polyethylene glycol mediated cell fusion was used to establish 22 monoclonal cell lines secreting anti-(T,G)-A—L antibody. Cell lines were derived from C3H.SW and B10 mice and produced antibody with light chains and predominantly γ₁, heavy chains. Fine-specificity analysis demonstrated that 15 cell lines made antibodies that also recognize a determinant present on GAT, GT (9:1) and GT (1:1), whereas little, if any, serum antibody demonstrates this cross-reaction. Fourteen antibodies, derived from both B10 and C3H.SW mice, bear idiotypic determinants defined by Lewis anti-[B10 anti-(T,G)-A—L], but only two, both from C3H.SW mice, react with Lewis anti-[C3H.SW anti-(T,G)-A—L]. Adsorption studies indicate that no hybridoma tested bore the complete set of idiotypic determinants defined by either serum.     

Raised carcinoembryonic antigen level as an indicator of recurrent disease in follow up of patients with colorectal cancer.

BACKGROUND. Serum carcinoembryonic antigen level is raised in 80% of patients undergoing colonic resection for cancer. Subsequent elevation in the follow-up period may precede signs and symptoms as an indicator of recurrent disease. there is little evidence that "classical" follow up of patients in the general surgical outpatient clinic improves either survival or quality of life. Regular carcinoembryonic antigen level estimation requested by the general practitioner, allied to day-case colonoscopic surveillance may be a more rational approach. AIM. A study was undertaken to investigate the relationship between raised carcinoembryonic antigen level and the recurrence of colorectal cancer in patients following a curative primary resection. METHOD. Retrospective analysis was carried out on the notes of 125 patients who had attended a dedicated hospital colorectal follow-up clinic between 1988 and 1992. Carcinoembryonic antigen level data were obtained by subsequent examination of the University of Edinburgh Department of Clinical Chemistry (immunoassay section) carcinoembryonic antigen database. RESULTS. A single carcinoembryonic level result of more than 100 ul-1 (normal range less than 60 ul-1) was found to be a highly sensitive (87%), specific (89%), and accurate (88%) indicator of recurrent disease. Raised carcinoembryonic antigen level preceded symptoms in 72% of patients with recurrence of colorectal cancer. CONCLUSION. Sequential laboratory estimation of carcinoembryonic antigen level organized by the general practitioner may represent an accurate method of detecting recurrent colorectal disease. Hospital review could be limited to colonoscopic surveillance and restaging of patients referred with evidence of recurrent disease.     

Mutations of OCTN2, an organic cation/carnitine transporter, lead to deficient cellular carnitine uptake in primary carnitine deficiency

Systemic primary carnitine deficiency (CDSP, OMIM 212140) is an autosomal recessive disease characterized by low serum and intracellular concentrations of carnitine. CDSP may present with acute metabolic derangement simulating Reye's syndrome within the first 2 years of life. After 3 years of age, patients with CDSP may present with cardiomyopathy and muscle weakness. A linkage with D5S436 in 5q was reported in a family. A recently cloned homologue of the organic cation transporter, OCTN2, which has sodium-dependent carnitine uptake properties, was also mapped to the same locus. We screened for mutation in OCTN2 in a confirmed CDSP family. One truncating mutation (Trp132Stop) and one missense mutation (Pro478Leu) of OCTN2 were identified together with two silent polymorphisms. Expression of the mutant cDNAs revealed virtually no uptake activity for both mutations. Our data indicate that mutations in OCTN2 are responsible for CDSP. Identification of the underlying gene in this disease will allow rapid detection of carriers and postnatal diagnosis of affected patients.     

Evaluation of a dipstick ELISA and a rapid immunochromatographic test for diagnosis of Dengue virus infection

Here we report standardization of a dipstick enzyme-linked immunosorbent assay (ELISA, Dipstick ELISA) and its comparative evaluation with a commercial Rapid PanBio Immunochromatographic test (IC test) for detection of Dengue (DEN) virus-specific IgM and IgG antibodies in patient sera. Among crude and purified viral antigens prepared from mouse brains or cell cultures, a DEN virus type 2 antigen purified from cell cultures by sucrose density gradient centrifugation was found superior in terms of the signal/ noise (S/N) ratio in the assay system. The sensitivity of detection of the virus by specific IgM antibody was improved by removal of IgG from patient sera prior to testing. The evaluation of the Dipstick ELISA by use of 156 serum samples revealed an overall accordance of 96% and 93% with the IC test in detection of IgM antibodies to DEN viruses (IgM antibodies) and IgG antibodies to DEN viruses (IgG antibodies), respectively. The sensitivity of the Dipstick ELISA and the IC test with reference to the mu-capture ELISA was 83% and 87%, respectively, with a specificity of 98% in both cases. The sensitivity of the Dipstick ELISA with reference to the IC test in detecting IgM and IgG antibodies was 84% and 94%, respectively, and the specificity of the Dipstick ELISA was 98% and 92%, respectively.