Search PubMed⌕ Search

Biomedical subjects

R Sommer

Publications and source records attributed to R Sommer.

At least 37 records · Page 2Linked to original sources
PubMed2000

Sonographic features of dialysis-related amyloidosis of the shoulder.

This study evaluated the diagnostic role of ultrasonography in dialysis-related amyloidosis in shoulders of chronically hemodialyzed patients. Fourteen shoulders of 12 long-term hemodialysis patients were examined. All patients had been on dialysis for at least 10 years. All patients had varying degrees of pain and limitations of movement in the studied shoulders. Dialysis-related amyloidosis was the presumed diagnosis in all patients. Any patient with a history of any disease, other than dialysis-related amyloidosis, capable of producing a pathologic shoulder condition was excluded. The following parameters were studied: supraspinatus and biceps tendon thickness, tendon tears, synovial thickening, and the presence of hypoechoic material around tendons and within bursae. All shoulders had a nonhomogeneous thickening, greater than 7 mm, of the supraspinatus tendon. Seven shoulders (50%) had abnormal thickening of the biceps tendon (4 mm or greater), and two shoulders had abnormal thickening of the subscapularis tendon. Hypoechoic deposits were seen in the subdeltoid bursae and biceps sheaths in five and six shoulders, respectively. Three shoulders showed partial tears of the supraspinatus tendon, one shoulder showed a tear in the biceps tendon, and one shoulder had a tear in the subscapularis tendon. Ultrasonography is an excellent imaging modality in diagnosing the presence of dialysis-related amyloidosis in symptomatic shoulders of long-term hemodialysis patients, without having to resort to invasive procedures. The results of previous studies have been confirmed and new ultrasonographic findings described. Of particular interest is the involvement of the subscapularis tendon in dialysis-related amyloidosis. Repeat ultrasonography can become an important way to follow-up progression of shoulder dialysis-related amyloidosis in hemodialyzed patients.

Adult↗
PubMed1999

Group A beta-hemolytic streptococcus meningitis: clinical and microbiological features of nine cases.

Group A beta-hemolytic streptococcus (GAS) meningitis is a rare disease in adults. We conducted a retrospective study to describe clinical and microbiological features of nine cases of GAS meningitis in Switzerland. Of nine patients, six had neurosurgical conditions, and five had upper respiratory tract infections. Eight cases were community-acquired. The outcome of GAS meningitis was favorable; only one patient died of neurosurgical complications. No patient presented with toxic shock syndrome. Serotyping failed to reveal a dominant strain, and genotyping revealed that two strains carried the gene encoding the streptococcal pyrogenic exotoxin C and that one strain carried the gene encoding the streptococcal pyrogenic exotoxin A. Our observations suggest that GAS meningitis in adults is associated with neurosurgical conditions and/or an upper respiratory tract infection.

Adolescent↗
PubMed1999

Quality of water used for haemodialysis: bacteriological and chemical parameters.

BACKGROUND: The bacterial and chemical contamination of dialysate fluids are important problems in haemodialysis therapy and may be caused by the water used for dialysate preparation. METHODS: We performed a survey of the microbiological and chemical quality of the water used in seven dialysis wards. Special attention was paid to the effects of each water treatment step, for example ion exchange, reverse osmosis and UV disinfection, on the number of bacteria (measured as colony forming units, CFU), the amount of endotoxin (endotoxin units, EU) and various chemical parameters, the main focus being on calcium, magnesium, sulphate, aluminium and heavy metals. RESULTS: CFU values exceeding the European Pharmacopeia value, determined at an incubation temperature of 22 degrees C, were found in the samples of raw water (20.0%, n=25), after ion exchange (66.7%, n=12), after reverse osmosis (33.3%, n=18) and also in samples of the dialysis water taken at the inlets (12.5%, n=40) and outlets (50.0%, n=18) of the machines. Whereas all raw water samples from the wards showed high mean values for endotoxin (0.56-9.10 EU/ml) and the endotoxin levels were often enhanced after ion exchange (0.13- >9.49 EU/ml), treatment by reverse osmosis led to a satisfactory decrease in endotoxin in all samples (<0.03 EU/ml). Sufficient reductions in calcium, magnesium and sulphate could only be achieved by the combined application of ion exchange and reverse osmosis. Mercury contamination was observed in the samples after ion exchange at three treatment plants, this was possibly caused by polluted regenerants. Increased amounts of aluminium, copper and zinc were found in water samples from different sites in the treatment systems and were caused by materials in contact with the water. CONCLUSIONS: A sufficient chemical water purification treatment system should consist of ion exchange and reverse osmosis. Attention has to be paid to the suitability of materials in contact with the water and of the chemicals used, for example regenerants or corrosion inhibitors. From the microbiological point of view, a safety UV disinfection step in the water-treatment system is favourable. To avoid bacterial recontamination periodic cleaning and disinfecting of the water-treatment and distribution systems, as well as the dialysis machine are essential. There is the need for complete guidelines regarding dialysis water that include all relevant chemical and microbiological parameters. Based on this standard, periodic examination of the water after each treatment step has to be performed.

Metals↗
PubMed1998

A bibliography of mental patients' autobiographies: an update and classification system.

OBJECTIVE: This article brings to the present earlier bibliographies of books written by former mental patients. These books provide an inside view of mental disorder that can be useful in teaching, public education, theory, and research, and they have played a catalyzing role in mental health reform and in theory development. METHOD: The authors list seven anthologies and 48 autobiographies of former patients published since 1980 and introduce a classification system intended to increase the research value of this important archive. RESULTS: Recent books of this genre show more individuals with a mood disorder and more therapists and more women as authors. CONCLUSIONS: The research potential of these books suggests the value of an electronic database for classifying and retrieving the information they contain.

Archives↗
PubMed1998

Interactions of "Limax amoebae" and gram-negative bacteria: experimental studies and review of current problems.

Free-living amoebae can harbour bacteria inside their cysts giving them a microhabitat and protecting them from disinfectants. The aim of this study was to evaluate the potential importance of "Limax amoebae" as vectors for environmental and nosocomial bacteria in a hospital. It was shown that free-living amoebae are ubiquitous in the investigated hospital, occur syntopically with facultative human pathogens (Comamonas acidovorans and Pseudomonas aeruginosa) and may serve as hosts not only for these but also for bacteria isolated from clinical specimens (Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa); temperature is apparently of crucial importance for the interactions between these microorganisms. Recent studies have shown that "Limax amoebae" apart from acting as protective hosts, may also play a role for the thermotolerance, invasiveness and antibiotic-resistance of bacteria. Considering also the reduced immune-status of many patients, this "symbiosis" of free-living amoebae and bacteria might still be of underestimated hospital-hygienic importance.

Acanthamoeba↗
PubMed1997

Social effects on duration in restaurants.

A nonreactive observational study in full-service restaurants showed group size to be positively correlated with length of stay. Among the serendipitous findings were the role of reading in lengthening duration and the paucity of lone diners in full-service restaurants.

Adult↗
PubMed1996

Increased inactivation of Saccharomyces cerevisiae by protraction of UV irradiation.

The principle of equi-effectivity of the product of intensity and exposure time (principle of Bunsen-Roscoe) of UV irradiation has been assumed to be valid for the inactivation of microorganisms in general. Earlier studies claimed higher survival of Escherichia coli B/r with fractionated irradiation compared with single-exposure survival. However, data on the inactivation effect of protraction of UV irradiation are not available. By means of a specially designed UV irradiation apparatus which secured absolute UV dose measurements throughout the experiments, the effects of variation of UV irradiation intensities (253.7 nm) and exposure times were tested on the inactivation of a bacterial virus (Staphylococcus aureus phage A994), a vegetative bacterial strain (E. coli ATCC 25922), and bacterial spores (Bacillus subtilis ATCC 6633) as well as three haploid laboratory strains (RC43a, YNN281, and YNN282) and two diploid strains (commercial bakery yeast strain and laboratory strain YNN281 x YNN282) or yeast (Saccharomyces cerevisiae) and spores of the latter diploid yeast strain. Each test organism was exposed to three UV intensities (0.02, 0.2, and 2 W/m2), with corresponding exposure times resulting in three dose levels for each intensity. Differences in inactivation rates were tested by analyses of variance and Newman-Keuls tests. Virus and bacteria showed no differences in inactivation rates by variation of intensities and exposure times within selected UV doses; hence, the principle of Bunsen-Roscoe could not be rejected for these strains. However, in the eukaryotic test strains of S. cerevisiae longer exposure times with lower intensities led to enhanced inactivation in both haploid and diploid strains, with a more pronounced effect in the diploid yeast strains, whereas in yeast spores in this dose rate effect could not be observed.

Bacillus subtilis↗
PubMed1995

Conserved and divergent expression aspects of the Drosophila segmentation gene hunchback in the short germ band embryo of the flour beetle Tribolium.

The segmentation gene hunchback (hb) plays a central role in determining the anterior-posterior pattern in the Drosophila embryo. We have cloned the homologue of hb from the flour beetle Tribolium and show that, on the basis of its expression pattern, most of its functions seem to be conserved between these two species. Like Drosophila, Tribolium has a maternal hb expression that appears to be under translational control by a factor at the posterior pole of the embryo. The maternal expression is followed by a zygotic expression in the region of the developing head and thoracic segments. During germ band extension, a posterior expression domain appears that is likely to be homologous to the posterior blastoderm expression of hb in Drosophila. These observations suggest that hb may have the same functions in early Drosophila and Tribolium development, despite the different types of embryogenesis in these two species (long versus short germ development). One differing aspect of hb expression in Tribolium concerns a structure that is not present in Drosophila, namely the serosa. An hb expression domain at the anterior pole precisely demarcates the border between the extraembryonic serosa and the embryonic field in the Tribolium embryo at an early stage, and hb protein remains expressed in the serosa cells until the end of embryogenesis.

Amino Acid Sequence↗
PubMed1994

Enhanced clastogenicity of contaminated groundwater following UV irradiation detected by the Tradescantia micronucleus assay.

The Tradescantia micronucleus (Trad-MCN) assay was used to determine clastogenic effects of contaminated groundwater collected near a hazardous waste landfill. Water samples were taken from a purification plant (activated charcoal filtration, UV irradiation) which was built to avoid groundwater contamination by this landfill. Five series of experiments were conducted during approximately 4 months. In addition, water samples were irradiated under laboratory conditions with increasing doses of UV light. Several field water samples gave positive, dose-dependent effects before filtration and irradiation. Maximal values (6.1 +/- 4.7 micronuclei (MCN)/100 tetrads) were six-fold above controls. UV irradiation of activated charcoal-filtered water resulted in an enhancement of MCN frequencies. Exposure of groundwater to UV irradiation in the laboratory led to a dose-dependent increase of micronuclei. At the highest dose (1500 J/m2) the MCN frequency was more than six times higher than in the unirradiated sample (5.4 +/- 1.0 vs. 0.8 +/- 0.4 MCN/100 tetrads). The clastogenicity of UV-irradiated samples decreased with a half-life of approximately 1 day. Irradiation of tap water did not increase the MCN frequency. Our results indicate that irradiation of water with UV light for disinfection purposes might lead to a transiently increased genotoxicity of chemically polluted water samples.

Hydrocarbons, Halogenated↗
PubMed1992

Monitoring of laboratory parameters during carbamazepine therapy in psychiatric patients.

In recent years, carbamazepine has increasingly also been used in psychiatric indications. However, the manifold action of this drug also manifests itself in a number of adverse effects. In a prospective study including 46 patients, who were given carbamazepine for psychiatric indications and most of whom were also treated with one or several other psychotropic drugs, the following laboratory parameters were determined at two-weekly intervals: red and white blood count, platelets, SGOT, SGPT, gamma GT, alkaline phosphatase, serum calcium, serum sodium, IgA, IgG, IgM. Statistically significant changes were found in erythrocytes, leucocytes, platelets (decrease), Gamma GT (increase), serum calcium (decrease), IgA, IgM (decrease). The clinical relevance of these changes is discussed.

Adolescent↗
PubMed1992

Collaborative research with a family support organization.

Technical assistance on seven self-surveys was provided to a statewide family support organization. The collaborative approach increased client involvement, offered significant economies, and reduced barriers to dissemination, at the same time requiring trade-offs between methodological rigor and utility to the group.

Communication↗
PubMed1992

Results of the multicenter evaluation of the CEDIA cortisol assay.

The present paper describes the multicenter evaluation of the CEDIA Cortisol test for total cortisol. The observed linearity of the test was between 1.2 and 50 micrograms/dL cortisol. The limit of detection was calculated as 1.2/dL. Imprecision studies covering the diagnostically relevant range (5-20 micrograms/dL cortisol) yielded coefficients of variation between 1.7-8.9% (within-run) and 2.7-10.5% (between-day). An interlaboratory survey using 41 human samples and three control sera demonstrated that the new CEDIA Cortisol assay has a good interlaboratory transferability. Method comparison studies between the CEDIA Cortisol test and EIA, FIA, FPIA, and various RIAs yielded an acceptable level of agreement and concordant results in most cases. Low cross-reactivity of the antibody used in the new cortisol assay was observed with precursors or metabolites of cortisol. Especially, dexamethasone did not cross-react. However, prednisolone, 6-methylprednisone, and corticosterone showed cross-reactivities. No limitation by endogenous interferences was observed. The CEDIA Cortisol assay permits the precise, fast and sufficiently specific determination of cortisol. Furthermore, it offers the advantages of a non-radioactive assay and can be performed conveniently on Boehringer Mannheim/Hitachi analyzers in combination with routine clinical chemistry.

Humans↗
PubMed1992

[Long-term therapy of immune neutropenia with high-dose 7S immunoglobulin in a child].

A 15 month old girl with suspected immune neutropenia was treated with high dose immunoglobulin because of recurrent infections over a period of 9 months. Before therapy her neutrophil counts were below 0.5 G/l. With monthly intravenous immunoglobulin her neutrophils remained above 0.5 G/l with one exception. Even after 9 months the patient responded well to therapy, she did not experience new episodes of infections. We suggest that in case of recurrent infections high dose immunoglobulin therapy should be considered in patients with immune neutropenia before the occurrence of life threatening infections.

Autoantibodies↗
PubMed1992

[The role of serum gliadin antibodies in the diagnosis of celiac disease].

Gliadin antibodies (IgA and IgG) have been determined by enzyme immunoassay (EIA) in our laboratory since 1987. 25 AU (arbitrary units) is recommended as the upper limit of the normal range. Here we report the results of the determinations of gliadin IgA antibodies in 70 patients suspected of having coeliac disease (CD), who underwent a small bowel biopsy for the first time. In 15 untreated patients with proven CD gliadin IgA antibodies ranged from 105 to 765 AU (median = 232 AU), in contrast to the findings in 55 patients with other gastrointestinal diseases (range from 0 to 175 AU, median = 9 AU; p less than 0.0001). The calculated sensitivity was 100% and the specificity reached 62% using 25 AU as a cut off. The recommendation of a higher cut off (50 AU) to achieve a higher specificity (82%) with equal sensitivity is discussed using the ROC curves and the Youden Index. Gliadin IgG antibodies were simultaneously determined in 29 out of the 70 patients. Taking 25 AU as a cut off the sensitivity was also 100% but the specificity was lower (29%) in comparison with gliadin IgA antibody testing. The determination of gliadin IgA antibodies by a standardized EIA is a highly sensitive diagnostic tool for screening candidates for small bowel biopsy suspected of having CD. The number of jejunal biopsies can be greatly reduced by using this test. It can also be used for monitoring patients under gluten-free diet or gluten challenge.

Antibodies↗
PubMed1991

Asterixis as a side effect of carbamazepine therapy.

A patient developed asterixis 13 weeks after starting a therapy with carbamazepine. Serum concentration of carbamazepine was within the therapeutic levels. Further factors which might have provoked asterixis were an impairment of pulmonary function and the combination with a neuroleptic and lithium. Since the latter risk factors had already been present for a long time, it may be assumed that the addition of carbamazepine triggered the development of asterixis.

Antipsychotic Agents↗