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Biomedical subjects

D Weinberg

Publications and source records attributed to D Weinberg.

At least 37 records · Page 2Linked to original sources
PubMed1995

Involvement of G-protein alpha il subunits in activation of G-protein gated inward rectifying K+ channels (GIRK1) by human NPY1 receptors.

This study investigated the type of G-protein alpha subunit(s) that human neuropeptide Y (NPY)1 receptors preferentially utilize when activating G-protein gated K+ currents. Two electrode voltage-clamp recordings were made from Xenopus oocytes that had been injected with cDNAs encoding either human NPY1 or D2(short) dopamine receptors, and GIRK1 a cloned rat brain K+ channel. These receptors were also co-injected with G-protein alpha i1, alpha i2, alpha i3 and alpha o1 subunits to determine which subunit(s) modulate the efficiency of signal transduction. In NPY1 receptor injected cells neuropeptide Y (100 nM) caused a 53 +/- 10 nA inward current (n = 14; EC50 = 3 nM) and this effect was blocked by pertussis toxin (500 ng ml-1 24 h). Activation of GIRK1 currents by neuropeptide Y was selectively potentiated by alpha i1 subunit cDNA whereas coupling dopamine of D2 receptors to this channel was not.

Animals↗
PubMed1995

Evaluation of a telepathology system between Boston (USA) and Dijon (France): glass slides versus telediagnostic TV-monitor.

The objective of this work was to compare diagnoses achieved through the traditional methods of current pathology practice versus diagnoses achieved through a selection of image on a telediagnostic TV-monitor. The Kappa coefficient between the two protocols of k = 0.26 SE(k) = 0.06 z = k/SE(k) = 4.3 (p < 0.001) allows us to conclude that there is a good reliability between video and glass slide diagnoses.

Boston↗
PubMed1994

[Intracavernous auto-injection of prostaglandin E1 for diagnosis and treatment of erectile dysfunction].

34 impotent patients were offered auto-injection therapy and all except 2 began treatment. Prostaglandin E1 (PGE) was used regularly for a mean of 8.6 months (range 1-17). The onset of erection was 5-30 min (mean 11.4) after injection and it lasted at least 30 min (mean 106.2 min). An erection of more than 6 hrs was observed in only 2 patients. There have been no instances of cavernous fibrosis, chemical priapism or systemic reactions. The most common adverse effect was penile pain after injection. It was mild to moderate in 4 patients (11.7%), and in only 1 was it severe enough to require stopping treatment. Overall, intracavernous injection of PGE appears to be safe, effective treatment for impotence without side-effects other than pain after injection in a few.

Adult↗
PubMed1993

Prognostic factors in medulloblastoma, including DNA ploidy.

PURPOSE: DNA ploidy status, completeness of surgical resection, use of chemotherapy, adequacy of radiation therapy, metastatic stage, sex, and age at diagnosis were evaluated as predictors of relapse in 58 patients with cerebellar medulloblastoma. METHODS: Flow cytometry (FCM) and/or image analysis (IA) were used to characterize tumor DNA ploidy. Twelve tumors (21%) were found to be aneuploid, 11 (19%) tetraploid, and 35 (60%) diploid. RESULTS: The most significant predictors of relapse in univariate analyses were the adequacy of radiation (> or = 50 Gy) (P = .02), metastatic staging (P = .05), completeness of resection (P = .085), and DNA ploidy status (diploid/tetraploid v aneuploid; P = .11). When the 52 patients who received > or = 50 Gy were included in a multivariate Cox model analysis, those with diploid/tetraploid tumors had fewer recurrences than those with aneuploid tumors (relative risk, 0.33; 95% confidence interval, 0.12 to 0.89; P = .03). Patients with complete resections (P = .07), or with stage M0 disease (P = .06) had fewer recurrences than other patients, but these factors were not independent predictors of outcome. DNA ploidy status was correlated with age; 10 of the 12 aneuploid tumors were found in children ages 3 to 10 years. Age, sex, and the use of chemotherapy were not prognostically significant in these analyses. CONCLUSION: The adequacy of radiation dose and DNA ploidy were the most important prognostic factors in this series. Contrary to previous reports, when corrected for adequacy of treatment, DNA aneuploidy was associated with a poor outcome. By multivariate analyses, DNA ploidy was an independent variable, even when controlling for extent of surgical resection and metastatic stage.

Aneuploidy↗
PubMed1992

Leiomyosarcoma of the bladder - ultrasonographic features.

We present a case in which the evaluation of a bladder mass revealed a leiomyosarcoma of the bladder. The ultrasonographic appearance of this tumor is described for the first time. Leiomyosarcoma of the bladder, although rare, should be considered in the differential diagnosis of pelvic masses.

Journal Article↗
PubMed1992

In vivo sodium chemical shift imaging.

The shift reagents thulium(III) 1,4,7,10-tetraazacyclododecane N,N',N",N"'tetramethylenephosphonate (TmDOTP5-), and dysprosium(III)triethylenetetramine-hexaacetate (DyTTHA3-) are compared in this work for their uses in sodium chemical shift imaging (NaCSI). In a series of experiments using phantoms we evaluated the relative contributions of bulk magnetic susceptibility (BMS) effects and hyperfine shifts to the induced 23Na chemical shift for these two shift reagents. The ratios of BMS effects to hyperfine shifts suggest that TmDOTP5- should be a more effective shift reagent than DyTTHA3- for 23Na NMR spectroscopy as well as NaCSI. The dependence on pH and free Ca2+ concentration of the 23Na NMR frequency shift induced by TmDOTP5- was evaluated. It was found that TmDOTP5- produces good spectral resolution under physiologic conditions. Examples presented from in vivo NaCSI experiments using TmDOTP5- to study diffusion in the posterior chamber of the rabbit eye and to monitor the rate of clearance of aqueous fluid from the anterior chamber demonstrate the effectiveness of this new shift reagent and of the NaCSI technique for in vivo studies.

Animals↗
PubMed1992

Assessing drug abusers with the Millon Clinical Multiaxial Inventory: a review.

This paper reviews studies that used the Millon Clinical Multiaxial Inventory with drug abusers. Although the test has been used with over 2000 such patients in the published literature, there is still a dearth of basic research with the MCMI with this population. Preliminary evidence suggests that the Personality Disorder Scales are quite useful to assess personality styles of drug abusers, but the Clinical Syndrome Scales present some problems. Specifically, the Drug Dependence Scale has had difficulty in reliably "detecting" drug addicted individuals who were in treatment for drug abuse. However, a reliable modal MCMI profile among this population seems to exist, although cluster research suggests several subtypes, each with different personality styles. MCMI computer-narrative reports may overdiagnose paranoid disorder and under diagnose antisocial disorders among this population.

Humans↗
PubMed1991

Improvement in visual acuity in chronic aphakic and pseudophakic cystoid macular edema after treatment with topical 0.5% ketorolac tromethamine.

Ketorolac tromethamine 0.5% ophthalmic solution treatment was compared to placebo treatment in 120 patients with chronic aphakic or pseudophakic cystoid macular edema (six-month or more duration of distance visual acuity of 20/40 or less and angiographic evidence of cystoid changes) during a four- to five-month double-masked, multicenter study in which patients were randomly assigned. A statistically significant improvement in distance visual acuity (two lines or more) was observed in the ketorolac-treated group as compared to the placebo-treated group after 30 days (P = .038), 60 days (P = .017), and 90 days (P = .008) of treatment. This improvement in visual acuity remained statistically significant one month after cessation of treatment (P = .001). Nine ketorolac-treated patients and two placebo-treated patients demonstrated a decrease in visual acuity one month after treatment was discontinued. Seven of the nine ketorolac-treated patients experienced an improvement in visual acuity after retreatment as compared to none of the placebo-treated patients. This study offers evidence for a more optimistic outlook in the medical treatment of chronic aphakic and pseudophakic cystoid macular edema.

Administration, Topical↗
PubMed1990

Transcription and translation of the chloroplast atpB-gene and assembly of ATP synthase subunit beta.

In vitro transcription and subsequent translation of the cloned Chlamydomonas chloroplast atpB gene was used to study assembly of ATP synthase. Translation in the presence of thylakoids resulted in association of the beta subunit with the membrane. The in vitro synthesized polypeptide bound to the membrane copurified with CF1 on sucrose gradients. This provides more evidence for the self-assembly of CF1.

Chlamydomonas↗
PubMed1990

Anatomy of arteriovenous crossings in branch retinal vein occlusion.

We studied the photographic records of 292 eyes, including 103 eyes with branch retinal vein occlusion, 90 fellow eyes, and 99 control eyes without branch retinal vein occlusion. All arteriovenous crossings within three disk diameters of the optic disk, including the crossings at the sites of branch retinal vein occlusions, were studied. The relative positions of the crossing artery and vein could be determined at 1,939 crossings in all eyes. Crossings at which a vein crossed over an artery were a common finding (22.3% to 33.0% of crossings), but were rare at the crossings where branch retinal vein occlusions were found (2.4%). A greater proportion of arterial overcrossings was found in eyes with branch retinal vein occlusions (77.7%) compared to fellow eyes (70.6%) or control eyes (67.0%). Our data indicate that arterial overcrossings are at relatively higher risk of branch retinal vein occlusion than venous overcrossings, and that the risk of branch vein occlusion in an eye is proportional to the number of arterial overcrossings in the eye.

Adult↗
PubMed1990

Exudative retinal detachment following central and hemicentral retinal vein occlusions.

We describe five eyes of five patients that developed an exudative retinal detachment following a central retinal vein occlusion (including one eye with a hemicentral [hemispheric] retinal vein occlusion). The time interval between the occurrence of the vein occlusion and the appearance of the retinal detachment ranged from 7 to 36 weeks in the four cases seen in the acute period. Each detachment involved the posterior retina and was associated with the development of marked retinal ischemia. Neovascular glaucoma occurred in two cases. The subretinal fluid completely or partially resorbed in the four eyes that were treated with retinal photocoagulation, but the final visual acuity was poor in all cases. Exudative retinal detachment is a potential complication of central retinal vein occlusion and in this series was associated with a poor visual prognosis.

Adolescent↗
PubMed1990

Expression of densonucleosis virus GmDNV in Galleria mellonella larvae: size analysis and in vitro translation of viral transcription products.

The RNA of densonucleosis virus type 1 (GmDNV), isolated from GmDNV-infected Galleria mellonella larvae, was shown by Northern blotting to contain five polyadenylated, viral-specific RNA species with sizes of 1.8, 2.4, 3.5, 4.0, and 5.0 kb. Poly(A)-containing RNA from whole larvae and hybrid-selected viral RNA were translated in a rabbit reticulocyte lysate system and the translation products were coelectrophoresed with proteins extracted from CsCl-purified virus. All four virion-associated proteins, namely p49, p55, p65, and p94, were present in the in vitro-translated products. However, in the majority of the experiments the most abundant translation product was a 30K polypeptide which is absent from virion extracts. The most abundant viral protein is p49, and the 49K polypeptide was also the most abundant translation product in about 30% of the preparations. The 1.8 kb transcript, which constitutes about half of the total viral RNA, is only slightly larger than the template required for a 30K polypeptide, suggesting that the latter may be a primary translation product of the smallest RNA transcript. The similarities in gene expression between densoviruses and mam malian parvoviruses are discussed.

Animals↗
PubMed1989

Biological grading of breast cancer using antibodies to proliferating cells and other markers.

Quantitation of immunohistochemical staining by image analysis was performed on 50 breast cancers stained with the monoclonal antibody Ki-67 to determine the growth fraction and its correlation with tumor grade. A high degree of correlation was shown. For each case the DNA ploidy was determined by quantitation of the DNA Feulgen stain by computerized microdensitometry. DNA content of breast tumor cells correlated to the histopathologic grade at which poorly differentiated tumors are more likely to be aneuploid. Quantitation of immunohistochemistry for estrogen and progesterone receptors had a high degree of correlation with the steroid binding assay, such as dextran-coated charcoal assay (DCCA), and were weakly correlated to histologic grade. In summary, our results indicated that quantitation of Ki-67-positive nuclear area and of DNA content by image analysis provides an objective method for assessing tumor cell growth fraction and DNA ploidy. Quantitation of steroid receptors by immunohistochemistry is a better and easier technique than those currently used to determine the best therapy for postmenopausal women. These methods can be performed on small frozen sections or needle aspirates in quantities that are insufficient for current steroid binding assays. Thus, this method is prognosticly useful even for patients with small breast lesions.

Antibodies, Monoclonal↗
PubMed1987

Factors affecting methane production in humans. Gastrointestinal diseases and alterations of colonic flora.

Breath methane was studied in 394 subjects. Among 152 controls, 50.0% produced methane--42.1% of males and 57.9% of females. One hundred sixteen patients with gastrointestinal diseases were studied. Among 32 with Crohn's disease, only 2 (6.1%) produced methane, as well as 16 of 51 ulcerative colitis patients (31.4%) and 11 of 32 patients with the irritable bowel syndrome (34.4%). Breath methane is thus unusual in Crohn's disease. After bowel cleansing for colonoscopy or surgery, 15 of 18 methane producers became nonproducers, whereas after antibiotic treatment, 24 of 30 producers sustained their methane-producing status. After gentamycin and cephazolin therapy, methane production was abolished in three of eight patients. Slight spontaneous variations in methane production were also noticed with two of 23 control subjects, becoming nonproducers on restudy after 10-25 months. Thus gastrointestinal diseases, bowel cleansing and, to a much lesser degree, antibiotic therapy, affect methane production.

Adolescent↗
PubMed1987

Pneumonia in pediatric outpatients: cause and clinical manifestations.

The cause and clinical manifestations of pneumonia were studied in 98 pediatric outpatients. A viral diagnosis was established in 38 (39%) of the 98 patients, and a bacterial diagnosis in 19 (19%). Ten (53%) of the 19 patients with bacterial pneumonia had a concurrent viral infection. No clinical, laboratory, or radiographic findings that would reliably differentiate viral from bacterial infection were identified. This study suggests that bacterial pneumonia is more common in pediatric outpatients than previously reported, and that the clinical, laboratory, and radiographic findings in patients with bacterial infection may be indistinguishable from findings in patients with viral infection.

Adolescent↗
PubMed1986

Synthetic atrial natriuretic factor does not dilate resistance-sized arteries.

The effects of synthetic atrial natriuretic factor and atriopeptin III on induced tone in resistance-sized arteries from the rat were examined in vitro. Cylindrical segments of small mesenteric or cerebral arteries were mounted on a microcannula and pressurized to a transmural pressure of 75 mm Hg. After equilibration, the level of tone in cerebral arteries was on the order of - 35 change in diameter; addition of atrial natriuretic factor or atriopeptin III in cumulative doses from 10(-10) to 10(-7) M did not produce any transient or sustained changes in diameter. Similarly, atrial natriuretic factor or atriopeptin III did not alter the contractile responses of cerebral vessels to serotonin or prostaglandin F2 alpha. Mesenteric arteries, which do not possess an intrinsic myogenic tone, were precontracted with potassium (30 mM), norepinephrine (10(-6) M), or prostaglandin F2 alpha (1.1 X 10(-5) M) and exposed to the synthetic natriuretic peptides, also without effect. Transmural electrical stimulation (0.3-msec pulses; 180 mA; 4/second) relaxed cerebral and contracted mesenteric arteries; preincubation in 10(-7) M atrial natriuretic factor or atriopeptin III did not alter subsequent responses. These observations suggest that the hypotensive action of atrial natriuretic factor cannot be attributed to direct vasodilation of splanchnic or cerebral resistance-sized arteries.

Animals↗