Search PubMed⌕ Search

Biomedical subjects

U Wiesmann

Publications and source records attributed to U Wiesmann.

At least 37 records · Page 2Linked to original sources
PubMed1996

Familial hypercholesterolaemia with severe cardiac involvement in a boy: successful management and mid-term follow-up.

A 13-year-old boy with double heterozygosity for familial hypercholesterolaemia with a 90% left coronary artery main stem stenosis is reported. The patient's cholesterol levels were effectively controlled with weekly sessions of selective low-density lipoprotein cholesterol removal through immunoadsorption by use of an extracorporeal system. Left main coronary artery stenosis was successfully treated with percutaneous transluminal balloon dilation. At 30 months after the intervention and still under treatment with weekly sessions of low-density lipoprotein apheresis the patient is free of cardiac symptoms. He shows normal exercise capacity and normal myocardial perfusion. It is concluded that aggressive management is justified in such patients and may result in a near-normal quality of life.

Angiography↗
PubMed1995

Enhanced anaerobic degradation of benzene by enrichment of mixed microbial culture and optimization of the culture medium.

A heterogeneous mixed culture, originally collected from two different sources, namely cow-drug and sludge from the city waste-water treatment plant, was grown in mineral medium containing 1% glucose and then adapted on benzene as the carbon and energy source. Under anaerobic conditions benzene was degraded via benzoic acid as a major intermediate in the benzene degradation pathway. The degradation rate of benzene was improved stepwise by the number of enrichments and optimization of the culture medium. The effects of microaerobic conditions and/or physicochemical treatment with H2O2 prior to anaerobic degradation were studied with respect to variations in benzene degradation rate, growth of biomass and gas composition. It was noticed that the amount of gas produced is less than the theoretical value expected and the percentage of methane in the product gas was very small (3%-3.5%). The reason for this is not well understood but it is presumed that the major group of benzene-degrading bacteria present in the culture medium are sulphate reducers and the mixed consortium is unable to degrade certain complex aromatic intermediates in the benzene degradation pathway under the experimental conditions. For an actual explanation of the situation arising in this study, further investigations must be carried out. However, the mixed culture is capable of oxidizing benzene more rapidly to intermediate compounds and also partly into gas under the culture conditions, compared to the published data for the anaerobic degradation of benzene.

Anaerobiosis↗
PubMed1995

[Angiokeratoma corporis diffusum without associated metabolic disorder].

In a 22-year-old woman with mental impairment and some signs of dysmorphism, numerous angiokeratomas developed, starting when she was 3 years old and resulting in the clinical picture of angiokeratoma corporis diffusum. Extensive laboratory analyses did not disclose any associated metabolic disorder,and electron microscopy failed to demonstrate lysosomal inclusions. Therefore, this patient can be classified as one of the rare cases of angiokeratoma corporis diffusum without associated metabolic disease (idiopathic angiokeratoma corporis diffusum).

Adult↗
PubMed1994

Development and evaluation of a spectrophotometric assay for complex III in isolated mitochondria, tissues and fibroblasts from rats and humans.

A spectrophotometric method to assay the activity of complex III in isolated mitochondria, tissues and fibroblasts from patients and rats has been developed and validated. Decylubiquinol was shown to be a suitable substrate with a saturating concentration between 100 and 200 mumol/l. The optimal pH was found to range from 7.4 to 8.0. The enzyme reaction was linear for incubations containing up to 15 micrograms/ml mitochondrial protein, 250 micrograms/ml liver tissue, 375 micrograms/ml skeletal muscle or 100 micrograms/ml fibroblast protein. Intraday and interday variability of the assay for different enzyme sources was below 15% and 10%, respectively. Assessment of complex III activity in liver and fibroblasts from patients with signs of mitochondrial dysfunction revealed the usefulness of the newly developed assay in the diagnosis of complex III deficiency.

Animals↗
PubMed1994

Biological nitrogen removal from wastewater.

A review of the research on the kinetics of nitrification and denitrification is presented including an explanation of reaction engineering models. The results of laboratory scale experiments with high rate nitrification processes are discussed using kinetic results for oxygen limitation as well as for substrate limitation and inhibition. It can be demonstrated that reaction engineering models are helpful for a better understanding of the processes and for the design of reactors. Pilot scale investigations from the last 15 years show remarkable advances in the increase in nitrification efficiency and in the stabilization of the process. The time is ripe for nitrogen removal from industrial effluents in full scale processes!

Models, Theoretical↗
PubMed1994

Feline mucopolysaccharidosis VII due to beta-glucuronidase deficiency.

A male cat 12-14 weeks old had walking difficulties and an enlarged abdomen. Facial dysmorphism, plump paws, corneal clouding, granulation of neutrophils, vacuolated lymphocytes, and a positive urine test for sulfated glycosaminoglycans suggested mucopolysaccharidosis. Cultured fibroblasts incorporated 35SO4 into mucopolysaccharides more actively than did fibroblasts of a feline control, and degradation was far inferior. Activity of beta-glucuronidase was absent in leukocytes and markedly reduced in fibroblasts, thus establishing the diagnosis of mucopolysaccharidosis VII, a disorder previously described in humans, dogs, and mice. Light microscopic examination revealed foam cells in virtually all organs examined, and electron microscopic examination showed pancytic storage of floccular material characteristic of mucopolysaccharides. Stored sphingolipids in the form of zebra bodies were seen in ganglion cells of the central nervous system and in smooth muscle cells of blood vessels. This case represents another animal model of mucopolysaccharidosis VII with the full disease characteristics known in human patients.

Animals↗
PubMed1993

Soluble factors from human hair papilla cells and dermal fibroblasts dramatically increase the clonal growth of outer root sheath cells.

Depending on environmental influences, follicular outer root sheath (ORS) cells in vivo can differentiate either towards interfollicular keratinocytes or, as demonstrated in the rat vibrissa, hair matrix cells. Crucial regulators of both their proliferation and differentiation are the mesenchymal cells of the respective tissues. The interactions of human ORS cells with human hair papilla cells (HPC) or human dermal fibroblasts (HDF) were studied using a two-chamber model separating the two cell types either by a microporous membrane or additionally by a medium layer. The results of 3H-thymidine incorporation studies indicated that ORS cell growth was markedly enhanced in co-culture with either HPC or HDF, the highest stimulatory effect resulting when ORS cells were in close association with the mesenchymal cells. No correlation was found between ORS cell proliferation and IL-6 production in the co-culture system, thus pointing to the secretion by HPC and HDF of growth-promoting soluble factors that are different form IL-6 as well as from EGF, bFGF and insulin present in the culture medium.

Biological Factors↗
PubMed1992

Co-culture of human keratinocytes on post-mitotic human dermal fibroblast feeder cells: production of large amounts of interleukin 6.

A large synthesis of human IL-6 was demonstrated in co-cultures of human keratinocytes on post-mitotic human dermal fibroblast (HDF) feeder layers. Immunoreactive IL-1 beta could be detected in the co-cultures and the addition of rabbit anti-IL-1 beta antibodies to the co-cultures considerably reduced the IL-6 synthesis, suggesting that it was induced by endogenous IL-1 beta. Addition of saturating concentrations of IL-1 beta to HDF feeder layers as well as to subcultures of keratinocytes induced in both similar but moderate IL-6 production. Conditioned medium from keratinocyte cultures induced IL-6 secretion in HDF feeder cells, whereas the conditioned medium from HDF feeder layers led to only minimal increase of keratinocyte IL-6 production. The co-cultures of keratinocytes on HDF feeder layers produced much larger amounts of IL-6 than the sum of the IL-6 produced by the feeder cell and keratinocyte cultures after the addition of IL-1 beta. The co-cultures of keratinocytes with HDF feeder layers separated by a permeable membrane in a two-chamber system produced significantly lower amounts of IL-6 than the unseparated co-cultures. These findings indicate that a direct cell contact between keratinocytes and feeder cells is involved in the overproportioned increase of IL-6 production and secretion into the medium.

Cell Communication↗
PubMed1991

Restoration of the epidermal phenotype by follicular outer root sheath cells in recombinant culture with dermal fibroblasts.

In order to better understand how outer root sheath (ORS) cells are able to reepithelialize superficial skin wounds, the level of epidermal differentiation achieved by isolated ORS cells in vitro was determined. Using postmitotic human dermal fibroblasts (HDF) as efficient feeder cells, large numbers of ORS cells from individual follicles were generated. Passaged ORS cells were grown exposed to air on HDF-populated collagen gels in the CRD device (Noser and Limat, In vitro 23, 541-545, 1987) which allows histiotypic tissue organization. In such recombinant organotypic cultures, ORS cells developed distinct epidermal strata comparable to interfollicular keratinocytes (NEK). Ultrastructurally, desmosomes and intermediate filaments increased in number toward the epithelial surface and small keratohyalin (KH) granules (but no large irregular KH granules as in NEK) were abundant, adjacent to an electrondense stratum corneum. Also, synthesis of epidermal suprabasal keratins (K1 and 10;2D gels) was lower in ORS cultures, but clearly visible suprabasally by immunofluorescence along with other epidermal markers (involucrin, filaggrin, surface glycoprotein gp80, pemphigus vulgaris antigen). Basement membrane components (laminin, type IV collagen, bullous pemphigoid antigen) were detectable in both ORS and NEK in these assays. Thus, phenotypic expression was largely comparable, but, whereas terminal differentiation (keratinization) was progressing in NEK cultures limiting their lifespan, this seemed to be better controlled in ORS cultures and viable cell layers persisted resulting in longer survival time.

Adult↗
PubMed1990

Early diagnosis and treatment of neonatal medium-chain acyl-CoA dehydrogenase deficiency: report of two siblings.

Two siblings are reported who were symptomatic in the neonatal period. The first died suddenly at 4 days of age after regurgitating a meal. The postmortem examination showed steatosis of the liver, kidney and muscle. In the second, medium-chain acyl-CoA dehydrogenase (MCAD) deficiency was diagnosed at 3 days of age with muscular hypotonia, vomiting, hyperammonaemia and mild acidosis. Thus disorders of fatty acid oxidation should also be considered in newborns. The biochemical work up indicates that in neonates, analysis of serum medium-chain fatty acids and of acyl and free carnitine are more likely to lead to a diagnosis than determining dicarboxylic acids alone in urine. Long-term treatment was effective and monitored by the acyl/free carnitine ratio.

Acid-Base Equilibrium↗
PubMed1990

Postmitotic human dermal fibroblasts preserve intact feeder properties for epithelial cell growth after long-term cryopreservation.

In vitro, human dermal fibroblasts (HDF) differentiate through morphologically and biochemically identified compartments. In the course of this spontaneous differentiation through mitotic and postmitotic states, a tremendous increase in cellular and nuclear size occurs. Induction of postmitotic states can be accelerated by chemical (e.g., mitomycin C) or physical (e.g., x-ray) treatments. Such experimentally induced postmitotic HDF cells support very efficiently the growth of cutaneous epithelial cells, i.e. interfollicular keratinocytes and follicular outer root sheath cells, especially in primary cultures starting from very low cell seeding densities. The HDF feeder system provides more fundamental and also practical advantages, i.e. use of initially diploid human fibroblasts from known anatomic locations, easy handling and excellent reproducibility, and the possibility of long-term storage by incubation at 37 degrees C. Conditions for the cryogenic storage of postmitotic HDF cells in liquid nitrogen are presented and related to the feeder capacity for epithelial cell growth. Because postmitotic HDF cells preserve intact feeder properties after long-term storage, the immediate availability of feeder cells and the possibility to repeat experiments with identical materials further substantiate the usefulness of this feeder system.

Cell Division↗
PubMed1989

In vitro pemphigus vulgaris model using organotypic cultures of human epidermal keratinocytes.

Using the Combi-ring-dish (CRD), a new culture device, organotypic cultures of human epidermal keratinocytes were grown on bovine eye lens capsules. In these highly differentiated cultures, typical suprabasal acantholysis was induced by pemphigus vulgaris antibodies. This in vitro pemphigus vulgaris model may be used to analyse keratinocyte-derived factors causing acantholysis in experimental pemphigus.

Acantholysis↗
PubMed1989

[Excretion of N-acetyl-beta-D-glucosaminidase in the urine of children with type I juvenile diabetes mellitus and of patients treated with the aminoglycoside amikacin].

N-acetyl-beta-D-glucosaminidase activity, alpha 1-microglobulin, albumin, and creatinine were determined in urine specimens of healthy children, age 4 months up to 15 years, and of children with type I diabetes and of juvenile patients receiving amikacin, an aminoglycoside antibiotic, during severe systemic infections. All resulting values were expressed per g of creatinine. beta-Glucosaminidase activity was determined colorimetrically using 3-cresolsulfonphthaleinyl-N-acetyl-beta-D-glucosaminide as a substrate. Creatinine was determined by a modified Jaffé reaction. alpha 1-microglobulin and albumin were measured by immunodiffusion. In normal urine beta-glucosaminidase activity showed a log-normal distribution with an upper limit 97.5 percentile of 3.61 U/g creatinine. In patients receiving amikacin for up to 3 weeks beta-glucosaminidase and alpha 1-microglobulin significantly rose to very high values (6-10 times) during the course of the treatment. Urinary albumin values was only doubled. All values returned to normal, days or occasionally weeks after discontinuation of the therapy. 3 groups of diabetic children could be distinguished using urinary beta-glucosaminidase as a discriminator a) children with repeatedly normal activities, b) children with intermittently elevated activities and c) children with repeatedly elevated activities. While alpha 1-microglobulin concentrations followed the same pattern, the excretion of albumin did not.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylglucosaminidase↗
PubMed1988

Different metabolic recycling of the lipid components of exogenous sulphatide in human fibroblasts.

Cultured human fibroblasts were fed with two differently labelled sulphatide molecules [one labelled on C-3 of the sphingosine (Sph) moiety [( Sph-3H]sulphatide), the second on C-1 of stearic acid [( stearoyl-14C]sulphatide)], and the intracellular metabolic fate of radioactivity was monitored. Incorporated radioactivity was almost all recovered in the total lipid extract, regardless of the labelling position of the added sulphatide; however, large differences in the level of incorporation occurred among labelled glycosphingolipids. For example, sphingomyelin was present as the major radiolabelled lipid after [Sph-3H]-sulphatide incubation, but was detectable only in trace amounts after [stearoyl-14C]sulphatide administration; in the latter case the radioactivity was located predominantly in glycerophospholipids. From this finding it can be inferred that the free long-chain base (sphingosine) that originates from lysosomal catabolism of sulphatide is mainly, and quite specifically, utilized for sphingomyelin biosynthesis, whereas the ceramide moiety is not; conversely the fatty acid released from ceramide is non-specifically re-utilized for phospholipid biosynthesis.

Carbon Radioisotopes↗
PubMed1988

Use of cultured keratinocytes in the treatment of severe burns.

A 6 1/2-year-old child was admitted to the emergency ward for third degree burn injuries representing 40% of body surface. Shock therapy was first applied. After débridement and in a series of operating sessions hands were grafted with full-thickness skin and most other wounds were covered with mesh grafts. On the 14th day after admission a piece of approximately 5 cm2 split thickness scalp skin was used to expand the keratinocytes by cell culture techniques according to the method of Rheinwald and Green (7). After 20 days 4 sheets of cells of first subculture, each 10 cm in diameter, representing a surface of approximately 300 cm2, were implanted on the front of the left thigh, which was burnt third-degree deep. Light microscopy of punch biopsies from mesh grafted and keratinocyte implanted sites taken 5 months after grafting showed a well differentiated epidermis overlying scar tissue. The following conclusions were drawn: Autologous keratinocytes did take on a third degree wound. No basic difference was observed neither clinically nor histologically between mesh-grafted and keratinocyte-implanted sites. The epidermis formed by keratinocyte implantation lacked pigmentation but presented an aesthetically better appearance than the mesh-graft treated sites. Given the scarcity of donor sites and the results obtained by implanting keratinocyte cultures, this latter technique may be resorted to in any extended and deep burn injury.

Burns↗
PubMed1987

Differentiation of L6 myoblastic cells into chondrocytes.

Under the influence of demineralized bone pieces L6 cells differentiate into chondrocytes. The cartilage formed is identifiable histologically. The results demonstrate that these myoblastic cells, which are committed to produce muscle, may still be influenced to express another potentiality of their genome.

Animals↗