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Biomedical subjects

D Wolf

Publications and source records attributed to D Wolf.

At least 109 records · Page 6Linked to original sources
PubMed1991

Entodermal inclusion cyst of the tricuspid valve.

This is a report on an epithelial inclusion cyst covering the septal leaflet of the tricuspid valve. The tumor was an accidental finding in a 5 1/2 years-old boy with congenital heart disease including double-chambered right ventricle, ventricular and atrial septal defects and subvalvular aortic stenosis. Histological examination showed a two-layered ciliated epithelium, typically present in the respiratory system. Embryologic tissue heterotopia arising from sequestered entodermal elements from the primitive foregut during cardiac organogenesis is a possible explanation for the locality and histology of the tumor. To our knowledge, a similar case has never been presented before.

Child, Preschool↗
PubMed1991

Adhesive properties of the beta 3 integrins: comparison of GP IIb-IIIa and the vitronectin receptor individually expressed in human melanoma cells.

Glycoprotein IIb-IIIa (alpha IIb beta 3) and the vitronectin receptor (alpha v beta 3), two integrins that share the common beta 3 subunit, have been reported to function as promiscuous receptors for the RGD-containing adhesive proteins fibrinogen, vitronectin, fibronectin, von Willebrand factor, and thrombospondin. The present study was designed to establish a cell system for the expression of either GP IIb-IIIa or the vitronectin receptor in an otherwise identical cellular environment and to compare the adhesive properties of these two integrins with those of native GP IIb-IIIa and the vitronectin receptor constitutively expressed in HEL cells or platelets. M21 human melanoma cells lack GP IIb-IIIa and use the vitronectin receptor to attach to vitronectin, fibrinogen, fibronectin, and von Willebrand factor. To study the functional properties of GP IIb-IIIa in these cells, we transfected GP IIb into M21-L cells, a variant of M21 cells (Cheresh, D.A., and R.C. Spiro. 1987. J. Biol. Chem. 262:17703-17711), which lack the expression of functional alpha v and are therefore unable to attach to vitronectin, fibrinogen, and von Willebrand factor. Transfectants expressing GP IIb were isolated by immunomagnetic beads and surface expression of the GP IIb-IIIa complex was documented by FACS analysis and immunoprecipitation experiments performed with 125I-labeled M21-L/GP IIb cells. Comparative functional studies demonstrated that GP IIb-IIIa expressed in M21-L/GPIIb cells as well as native GP IIb-IIIa constitutively expressed in HEL-5J20 cells (an HEL variant lacking alpha v beta 3) mediated cell attachment to immobilized fibrinogen, but not to vitronectin or von Willebrand factor, whereas the vitronectin receptor expressed in M21 cells and HEL-AD1 cells (an HEL variant expressing alpha v beta 3) mediated cell attachment to fibrinogen, vitronectin, and von Willebrand factor. Similarly, PGl2-treated resting platelets attached to immobilized fibrinogen but not to vitronectin or von Willebrand factor, and this attachment could be inhibited by mAb A2A9 (directed against a functional site on the GP IIb-IIIa complex). However, in contrast to platelets, which adhered to vitronectin and von Willebrand factor after stimulation by thrombin or PMA, activation of the protein kinase C pathway in M21-L/GP IIb or HEL cells did not induce cell adhesion to vitronectin or von Willebrand factor.(ABSTRACT TRUNCATED AT 400 WORDS)

Blood Platelets↗
PubMed1991

Characterization of prejunctional muscarinic autoreceptors in the guinea-pig trachea.

1. The effects of ten muscarinic antagonists on electrically evoked [3H]-acetylcholine release and muscle contraction were compared in an epithelium-free preparation of the guinea-pig trachea that had been preincubated with [3H]-choline. 2. The M3-selective antagonists UH-AH 37, 4-diphenyl-acetoxy-N-piperidine methobromide and para-fluorohexahydrosiladiphenidol were more potent in reducing the contractile response than in facilitating the evoked [3H]-acetylcholine release. Hexahydrosiladiphenidol did not discriminate between pre- and postjunctional effects. The rank order of the postjunctional potencies of the ten antagonists as well as the postjunctional pA2 values obtained for hexahydrosiladiphenidol (7.95) and AQ-RA (7.08) identified the muscular receptor as an M3 subtype. 3. The M2-selective antagonists methoctramine, AF-DX 116 and AQ-RA 741 were more potent in facilitating the evoked [3H]-acetylcholine release than in inhibiting the contractile response. The increase in release by low concentrations of methoctramine, AF-DX 116 and AQ-RA 741 was paralleled by an enhancement of the stimulation-evoked contractions. 4. Comparison of the pre- and postjunctional potencies of the M1-, M2- and M3-selective antagonists suggests that autoinhibition of acetylcholine release is mediated via an 'M2-like' receptor which differs from the cardiac type M2 receptor in its relatively high affinity for hexahydrosiladiphenidol.

Acetylcholine↗
PubMed1991

Elevated creatine phosphokinase and creatine phosphokinase-MB in acute laryngitis.

Elevated creatine phosphokinase (684 mU/ml) and creatine phosphokinase-MB (3.5%, 23.9 mU/ml) were observed in a 66 year old female with acute laryngitis. The patient had received L-thyroxine because of hypothyroidism for 10 years and her T3 and TSH levels were normal. Acute myocardial infarction was denied by repeated EKG findings. The mechanisms of the enzyme abnormality were discussed.

Aged↗
PubMed1990

Identification and characterization of C-terminal fragments of the beta-amyloid precursor produced in cell culture.

The mechanism of amyloid formation in Alzheimer's disease is unknown but appears to involve proteolytic processing of the amyloidogenic peptide from a larger precursor. When the C-terminus containing the amyloid-forming and cytoplasmic domains of the precursor was recombinantly expressed in cultured mammalian cells, a 16 kd protein accumulated which had a tendency to aggregate and form deposits. These deposits had physical characteristics resembling those of preamyloid. Recombinant expression of the full-length precursor was found to produce a similar, cell-associated 16 kd C-terminal fragment as well as a 12 kd fragment, neither of which formed detectable aggregates suggesting efficient catabolism of these fragments. Identification of these two naturally occurring metabolic products of the beta-amyloid precursor provides a system permitting the characterization of the proteolytic processing events of the amyloid precursor protein.

Alzheimer Disease↗
PubMed1990

Differentiating major depression from adjustment disorder with depressed mood in the medical setting.

Although the psychiatric consultant in the general hospital setting is frequently called on to distinguish major depression from adjustment disorder, no studies to date have examined whether the two diagnoses are in fact distinguishable. Analysis of computerized data base records from 944 cases seen by psychiatric consultants from 1981-1987 revealed 59 cases of major depression and 130 cases of adjustment disorder with depressed mood. Patients with major depression were more likely to be older (p less than 0.001), widowed (p less than 0.001), and living alone (p less than 0.005). Patients with adjustment disorder with depressed mood received higher ratings on Axis IV (p less than 0.01), and lower severity of illness ratings (p less than 0.001) were seen later in the hospital stay (p less than 0.05), and they were more likely to be rated by the consultant as improved by the time the case was terminated (p less than 0.001). The results suggest that the two disorders may be distinguished in the consultation population and that adjustment disorder with depressed mood may have descriptive validity in the medical inpatient setting.

Adaptation, Psychological↗
PubMed1990

In vitro susceptibility of Campylobacter jejuni and Campylobacter coli isolated in Austria to erythromycin and ciprofloxacin.

More than 200 strains of Campylobacter (C.) jejuni/coli isolated in 1985 and 1987/88 from human fecal specimens were tested for their susceptibility to erythromycin and ciprofloxacin. Their MIC90 as assessed by agar dilution tests was 2.0 and 0.5 mg/l, respectively. Thus, all strains were regarded as susceptible to ciprofloxacin. With 2 out of 55 strains of C. coli the MIC of erythromycin was 8.0 mg/l. Therefore, only 3.6% of the C. coli strains were resistant to erythromycin. All 209 strains of C. jejuni proved to be susceptible to erythromycin.

Austria↗
PubMed1990

Frequency of occurrence and characterization of catalase negative Campylobacter isolated from human feces in Vienna.

Of a total of 124 Campylobacter (C.) strains isolated 1988 from fecal specimens, 4 (3.2%) were catalase-negative. Two strains were catalase-negative variants of C. jejuni. The other two were identified as C. upsaliensis on the basis of their biochemical properties and of the results of DNA-DNA hybridization with biotinylated probes from C. upsaliensis and C. jejuni. Both had been isolated from patients after their return from Asia (India and Thailand, respectively). In one case, a significant decrease of the antibody titre was observed within 12 months when the patient strain was used as an antigen. Since this patient had been suffering from diarrhoea during her stay and since with the exception of amoebic cysts, no other intestinal pathogen was isolated, C. upsaliensis is thought to have been the reason for the diarrhoeal episode.

Adult↗
PubMed1990

IgG oligoclonal bands in sera of HIV-1 infected patients are mainly directed against HIV-1 determinants.

In a series of 60 HIV-1-infected individuals, serum electrofocusing analysis disclosed clonally restricted IgG patterns in 9 patients (15%), most with limited disease progression (stages WR1-WR3). These oligoclonal bands had a very heterogeneous light chain pattern, and most showed specificity for HIV-1 in affinity-driven transfer studies; virus specificity was more clear-cut following adsorption of sera with the relevant antigen. These findings further stress the profound B-cell function derangement in HIV-1 infection; their possible relevance to AIDS-associated lymphoma development is discussed.

Acquired Immunodeficiency Syndrome↗
PubMed1990

The synthetic androgen mibolerone induces transient suppression of the transformed phenotype in an androgen responsive human prostatic carcinoma cell line.

The synthetic androgen mibolerone elicits a set of distinct changes in the behaviour of an androgen responsive human prostatic carcinoma cell line (LNCaP). Inhibition of cell proliferation, induction of morphological change and of a prostate specific mRNA, and inhibition of colony formation in soft agar are induced by very low concentrations of mibolerone. The natural androgen dihydrotestosterone is much less effective. The changes in growth characteristics and morphology are reverted by excess antiandrogen, i.e. cyproterone acetate or hydroxyflutamide. Cell lines lacking androgen receptors (PC-3, DU 145 and MRC-5) are completely unresponsive to mibolerone. Taken together, our results indicate androgen receptor mediated suppression of the transformed phenotype in LNCaP cells.

Androgen Antagonists↗
PubMed1989

The use of a spreadsheet computer program to expedite TLD reporting.

A method has been devised using an electronic spread sheet that will shorten the data processing time and give a printed report of the results. Lithium Fluoride chips are used in pairs so as to produce the same average response. The raw TL readings along with descriptive comments are entered into the computer. The program then computes the single chip dose, the average dose for each chip pair, applies a non-linearity correction factor and prints out a report with comments and patient data. The program offers several advantages: It is much faster than hand calculations, it provides a precise and accurate conversion of raw data to final data, and outputs an organized display of calibration factors, input data, dosimetry data, patient data and listing of involved personnel. The program is easy to use and can be run on any computer that can support a spreadsheet program.

Calibration↗