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Biomedical subjects

J Berger

Publications and source records attributed to J Berger.

At least 289 records · Page 16Linked to original sources
PubMed1991

Low catalase levels in the epidermis of patients with vitiligo.

Suction blister roofs taken from the involved and uninvolved epidermis of patients with vitiligo showed a consistent reduction in levels of catalase compared to normal healthy controls of matched photo-skin types (Fitzpatrick classification). A decrease in catalase activity is expected to increase the concentration of hydrogen peroxide in the epidermis of these patients. Hydrogen peroxide functions as a reversible inhibitor of human tyrosinase with a KI of 8 X 10(-6) M. Also, hydrogen peroxide undergoes photochemical reduction yielding highly reactive hydroxyl radicals (OH.) and hydroxyl ions (OH-) mainly by the Haber-Weiss reaction. Hydroxyl radicals are capable of bleaching constitutional melanin and cause membrane lysis through lipid peroxidation reactions. Hydroxyl ions increase the pH in the epidermis, and as a consequence glutathione reductase activity is increased in patients with vitiligo compared to controls. Based on these new results, together with the previously reported calcium transport defect, a new hypothesis has been formulated for the pathogenesis of vitiligo.

Catalase↗
PubMed1991

Functional mapping of the human immunodeficiency virus type 1 Rev RNA binding domain: new insights into the domain structure of Rev and Rex.

Expression of human immunodeficiency virus type 1 (HIV-1) structural proteins requires the direct interaction of the viral trans-activator protein Rev with its cis-acting RNA sequence (Rev-response element [RRE]). A stretch of 14 amino acid residues of the 116-amino-acid Rev protein is sufficient to impose nucleolar localization onto a heterologous protein. Our results demonstrated that these same amino acid residues confer Rev-specific RRE binding to the heterologous human T-cell leukemia virus type I Rex protein. In addition, our results indicated that amino acids distinct from the nuclear localization signal are important for Rex-specific RRE RNA binding.

Amino Acid Sequence↗
PubMed1991

Vitiligo and cutaneous melanoma. A case study.

The examination of 623 melanoma patients in North Germany yielded the depigmentation disorder vitiligo in 23 cases (i.e. 3.7%). In 11 patients, the disease preceded their tumor, whereas in 11 patients, vitiligo developed after diagnosis of primary and/or metastatic melanoma into the regional lymph nodes. In 1 case, the onset of melanoma in relation to the tumor remained undefined. The prevalence of vitiligo increased with tumor risk factors based on tumor thickness and anatomical site of tumor location (i.e. for low risk 1.75%, intermediate risk 5.2% and high risk 5.8%). A comparison of the prevalence of vitiligo to the normal population of Northwestern Europe (i.e. 0.38-0.57%) showed a 7- to 10-fold increase for the patients with melanoma. A reverse analysis of the data yielded a 180-fold higher prevalence of melanoma in the group of patients with vitiligo. These results strongly support a more thorough examination of patients with vitiligo for primary melanoma.

Abdomen↗
PubMed1991

Amoxicillin-clavulanic acid for treating drug-resistant Mycobacterium tuberculosis.

This report describes two patients with multidrug resistant tuberculosis who were successfully treated with the addition of amoxicillin-clavulanic acid to second-line drugs. Mycobacterium tuberculosis possesses a beta-lactamase contributing to its resistance to beta-lactam antibiotics. The combination of clavulanic acid, a beta-lactamase inhibitor, and amoxicillin has been shown bactericidal for M tuberculosis in vitro. These data suggest that resistant tuberculosis may warrant a trial of treatment including amoxicillin-clavulanic acid.

Adult↗
PubMed1991

[Immediate breast reconstruction with tissue expander].

The technique of immediate breast reconstruction, using the tissue expander and replacing it with a permanent silicone prosthesis, has been applied with increasing frequency during the past several years. We chose this technique for immediate breast reconstruction because of its simplicity, rapidity when combined with mastectomy, and good esthetic results. We have performed 29 immediate breast reconstructions in the past 1.5 years in patients ranging from 22 to 72 years (mean 47). The insertion of the tissue expander added only 20-30 minutes of operating time for the mastectomy, and did not prolong hospitalization. Before we began to replace the expander with a permanent silicone prosthesis there were complications in 4 patients (14%). These included development of a seroma in 3, 1 of which became infected 40 days after insertion of the tissue expander, and capsular contraction in a patient who had previously had radiotherapy to her breast. The case with the infection was the only failure and the expander had to be removed. Immediate reconstruction of the breast is easily performed and can be of tremendous psychological benefit to mastectomy patients. Chemotherapy or radiotherapy are not contraindications to this type of reconstruction.

Adult↗
PubMed1991

[Computers in hematology].

Computerization of haematology comprises three areas: 1. hospital information system, 2. specific applications in haematology, 3. a support of scientific work and laboratory administration. IBM AT compatible computers seem to be the most widespread. The brains of recent computers are in software and, therefore, the price of large programmes can exceed that of a computer. Comprehensive clinical computer expert programmes are the aim of research work. However, specific not comprehensive programmes are used in haematological practice. Computer support of a haematological laboratory, including many numeric and other data, can be very effective. Computers in a modern haematological laboratory ensure automatic transport of data, internal quality control, management of laboratory work; they are an integral part of many modern devices. Recent software can also make scientific research and administrative work easier.

Computer Systems↗
PubMed1991

[Effects od iron supplementation on malaria infection].

An iron supplementation trial had been performed in a southern village of Togo during the rainy season when occurs malaria transmission. 241 infants from 6 to 36 months old were matched in two randomized groups. The first one (G1) received oral iron supplementation every day during three months. The second group (G2) received placebo. Tablet administration was double blind made. A third group (G3) had been created from two others with anaemic infants and received daily iron supplementation. Three biological and clinical surveys were done, i) before the trial (T0), ii) after supplementation (T3) and iii) six months later (T9). Several parameters were studied including malaria parasite density and titration of malaria antibodies. For each group the prevalence of Plasmodium falciparum was identical in the three surveys. Means of parasite density decreased during and after rainy season but variations were not significant. High parasitaemia frequency (i.e. greater than 10,000 parasitized red cells per mm3, considered as pyrogenic threshold) were identical in all groups and decreased after rainy season. Antibodies titers did not show any variation in the three groups. It seems that iron supplementation did not modify in 6 to 36 months infants the susceptibility to malaria nor the organism response.

Animals↗
PubMed1990

A double-blind comparison of metoprolol CR/ZOK 50 mg and atenolol 50 mg once daily for uncomplicated hypertension.

In a double-blind study with parallel groups, the clinical bioequivalence of the antihypertensive effect of metoprolol CR/ZOK (controlled release formulation) 50 mg and atenolol 50 mg in ordinary tablets given once daily for uncomplicated hypertension was investigated. Clinical bioequivalence was defined as difference in blood pressure reduction less than 8 mmHg. The study involved 195 patients, 98 on metoprolol CR/ZOK and 97 on atenolol. All patients were taken off antihypertensive therapy during a 2-week placebo run-in period. Thereafter the patients were randomly allocated to metoprolol CR/ZOK 50 mg or atenolol 50 mg for 4 weeks. In patients with a diastolic blood pressure remaining above 90 mmHg, the dose was increased to 100 mg daily of the respective drug. After 4 weeks treatment with 50 mg of the two therapies, blood pressure and heart rate was significantly reduced in both treatment groups. At this dose, clinical bioequivalence was found regarding both blood pressure and heart rate reductions. After 8 weeks of therapy (100 mg doses given to 31 in the metoprolol group and 43 in the atenolol group), clinical bioequivalence according to stated definition was found for blood pressures and heart rate reductions, although the reductions of systolic and diastolic blood pressures at rest as well as diastolic blood pressure during exercise were significantly greater in the metoprolol group. In an evaluation of the responder rate after the 8 weeks of treatment, 89% of the patients in the metoprolol CR/ZOK group and 74% in the atenolol group (P less than .05) had a diastolic blood pressure reduction to 90 mmHg or less.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Characterization and grouping of Trypanosoma cruzi stocks by DNA base-specific fluorochromes and discriminant analysis.

Fluorochromes with G-C and A-T specificity were used for a single-cell DNA analysis of the blood-stream forms of 14 Trypanosoma cruzi stocks in a cytofluorometric assay. The kinetoplast contained 22.3%-37.9% of the total DNA G-C base content and 42.7%-63.5% of the total DNA A-T base content. In spite of these differences, the mean base A-T/G-C ratio of the total DNA was 1.11 and was nearly constant in all stocks. The G-C base ratio of kinetoplast/nucleus resulted in a grouping corresponding with the peanut agglutinin (PNA)- and wheat germ agglutinin (WGA)-type characteristics of the T. cruzi stocks. The discriminant analysis revealed relationships, in that each stock contained some trypanosomes with DNA fluorescence characteristics of common to at least one other stock. After chromomycin A3 staining, the mean hit rates for the classification into group 1 PNA and the WGA group were 99% and 96%, respectively, and the respective rates obtained after DAPI application were 84% and 94%.

Animals↗
PubMed1990

[Epidemiology of hypertension and hypercholesterolemia: results of a mass screening in the framework of "a week in Kiel" 1988].

A screening for total cholesterol levels and blood pressure was conducted in Kiel during the sailing competition 1988 following the suggestion of the American Health Foundation. During the ten days of the testing 2063 visitors were screened, aged 5 to 88 years. Two thirds of the participants had no idea about the connection between high blood pressure, elevated cholesterol levels and the risk of coronary heart disease. The percentage of subjects with normotonic blood pressure decreased from 98 to 63% by age. Concerning the cholesterol levels the percentage of subjects at moderate risk for coronary heart disease increased from 20 to 80% by age and beyond fifty years of age the persons had cholesterol levels above 240 mg/dl. The total cholesterol levels increased by cigarette smoking. Our results demonstrate the need to improve the efforts of health education for lowering the cholesterol levels in the population, and thereby lead to a reduction in the morbidity and mortality of coronary artery disease.

Adolescent↗
PubMed1990

Acinic cell carcinoma of the salivary glands: the prognostic relevance of DNA cytophotometry in a retrospective study of long duration (1965-1987).

Acinic cell carcinomas of the Salivary Gland Registry, Institute of Pathology, University of Hamburg, West Germany, from 1965 to 1980 (n = 55) were evaluated retrospectively with respect to histologic, cytophotometric, and clinical data. The majority of the tumors (92.8%) were located in the parotid gland. Two thirds of the patients were female; one third were male. Mean age at primary diagnosis was 55.4 years. The tumors were graded into highly differentiated (76%) or less differentiated forms (24%) according to classic histologic and cytologic criteria. The clinical course was characterized by no recurrence in 15 cases; in 17 cases, recurrences developed, and 12 patients died of their tumor, some as late as 240 months after primary diagnosis. Differentiation showed a weak correlation with the clinical course. In 35 cases, nuclear DNA content of tumor cells was assessed cytochemically. The tumors were "diploid" or "near-diploid" in 34 cases; DNA content showed no correlation to the clinical course. As a result of long-term follow-up, it becomes evident that acinic cell carcinoma is prone to develop recurrences and metastases. Complete tumor removal during the primary operation seems to be important for controlling the disease inasmuch as the ostensible prognostic predictors evaluated here proved to be unreliable.

Adolescent↗
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

Affinity of 2-(tetrahydroisoquinolin-2-ylmethyl)- and 2-(isoindolin-2-ylmethyl)imidazolines for alpha-adrenoceptors. Differential affinity of imidazolines for the [3H]idazoxan-labeled alpha 2-adrenoceptor vs the [3H]yohimbine-labeled site.

A series of 2-(tetrahydroisoquinolin-2-ylmethyl)- and 2-(isoindolin-2-ylmethyl)imidazolines were prepared and tested for alpha 1- and alpha 2-adrenoceptor affinity with radioligand binding. Several compounds, 5-fluoro-(5h), 5-chloro-(5j), 5,8-dimethoxy- (5r), and 5,8-dimethoxy- (5r),1-methyl- (5s) 2-(tetrahydroisoquinolin-2- ylmethyl)imidazoline, were found to be selective alpha 2-adrenoceptor ligands on the basis of displacement of [3H]yohimbine from rat cerebral cortical membranes. One compound, 2-[(8-chloro tetrahydroisoquinolin-2-yl)methyl]imidazoline (5m), showed a 36-fold difference in affinity for the [3H]idazoxan-labeled alpha 2-adrenoceptor relative to the [3H]yohimbine-labeled site, which may be evidence for alpha 2-adrenoceptor subtypes.

Animals↗
PubMed1990

1,9-Alkano-bridged 2,3,4,5-tetrahydro-1H-3-benzazepines with affinity for the alpha 2-adrenoceptor and the 5-HT1A receptor.

A number of 1,9-alkano-bridged 2,3,4,5-tetrahydro-1H-3-benzazepines were prepared and evaluated for 5-HT1A receptor and alpha 2-adrenoceptor affinity by using radioligand receptor binding techniques. Several compounds displayed 5-HT1A receptor affinity comparable to, or greater than, the known 5-HT1A ligand buspirone. The highest affinity 5-HT1A receptor ligands were N-alkyl-, N-allyl-5-chloro-, and 5-methoxy-1,2,3,4,8,9,10,10a-octahydronaphth[1,8-cd]azapines (4c, 4m, 4n), which had pKi values of 7.9-8.1. The S enantiomer of 4c had a higher affinity for the 5-HT1A receptor than the corresponding R isomer (pKi of 8.2 for (S)-4c vs 7.7 for (R)-4c). These compounds had a relatively low affinity for the alpha 2-adrenoceptor (pKi of 7 or less). On the other hand, the closely related 5-chloro-2-methyl-2,3,4,8,9,9a-hexahydro-1H-indeno[1,7-cd]azepine (3b) had high affinity for both the alpha 2-adrenoceptor (pKi = 8.1) and 5-HT1A receptor (pKi = 7.6). These results indicate that the two receptors may share common recognition sites.

Animals↗
PubMed1990

Selectivity of the cleavage/attachment site of phosphatidylinositol-glycan-anchored membrane proteins determined by site-specific mutagenesis at Asp-484 of placental alkaline phosphatase.

Many proteins are now known to be anchored to the plasma membrane by a phosphatidylinositol-glycan (PI-G) moiety that is attached to their COOH termini. Placental alkaline phosphatase (PLAP) has been used as a model for investigating mechanisms involved in the COOH-terminal processing of PI-G-tailed proteins. The COOH-terminal domain of pre-pro-PLAP provides a signal for processing during which a largely hydrophobic 29-residue COOH-terminal peptide is removed, and the PI-G moiety is added to the newly exposed Asp-484 terminus. This cleavage/attachment site was subjected to an almost saturation mutagenesis, and the enzymatic activities, COOH-terminal processing, and cellular localizations of the various mutant PLAP forms were determined. Substitution of Asp-484 by glycine, alanine, cysteine, asparagine, or serine (category I) resulted in PI-G-tailed and enzymatically active proteins. However, not all category I mutant proteins were PI-G tailed to the same extent. Pre-pro-PLAP with other substituents at position 484 (threonine, proline, methionine, valine, leucine, tyrosine, tryptophan, lysine, glutamic acid, and glutamine; category II) were expressed, as well as the category I amino acids, but there was little or no processing to the PI-G-tailed form, and this latter group exhibited very low enzyme activity. The bulk of the PLAP protein produced by category II mutants and some produced by category I mutants were sequestered within the cell, apparently in the endoplasmic reticulum (ER). Most likely, certain amino acids at residue 484 are preferred because they yield better substrates for the putative "transamidating" enzyme. In transfected COS cells, at least, posttranslational PI-G-tail processing does not go to completion even for preferred substrates. Apparently PI-G tailing is a requisite for transport from the ER and for PLAP enzyme activity. Proteins that are not transamidated are apparently retained in the ER in an inactive conformation.

Alkaline Phosphatase↗