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Biomedical subjects

B Busse

Publications and source records attributed to B Busse.

18 recordsLinked to original sources
PubMed2006

[Fluorosis--a forgotten entity. Case report of a woman with coxarthrosis and newly diagnosed fluorosis].

The clinical manifestation of fluorosis has become rare over the past years. Although the use of fluoride medication in osteoporosis therapy remains controversial, past study results have led to a reduction in fluoride prescriptions. Several studies have shown minor biomechanical properties of newly built woven bone compared to original bone. Despite new prescription protocols, fluoride therapy should not be disregarded in the anamnesis of osteoporosis patients. In addition to conventional diagnostics in fluorosis, new techniques such as microanalysis and micro-CT-analysis show a diagnostic benefit. In this case, the edx-microanalysis results show an F concentration of over 1.0 wt% in bone. The ratio of bone to tissue volume, evaluated by micro-CT, is clearly elevated at 46% BV/TV. The histopathological preparation of the femoral head has made the possible effects of fluoride medication on bone visible and quantifiable. A direct causal relationship between coxarthrosis and fluoride medication, found both in our patient as well as in the literature, has not been demonstrated. In order to better understand the broad effects of fluoride medication in combination with coxarthrosis more studies are needed.

Aged↗
PubMed2003

Sound attenuation study on the bose-Einstein condensation of magnons in TlCuCl3.

We investigate experimentally and theoretically sound attenuation in the quantum spin system TlCuCl3 in magnetic fields at low temperatures. Near the point of Bose-Einstein condensation of magnons a sharp peak in the sound attenuation is observed. The peak demonstrates a hysteresis as a function of the magnetic field pointing to a first-order contribution to the transition. The sound damping has a Drude-like form arising as a result of hard-core magnon-magnon collisions. The strength of the coupling between lattice and magnons is estimated from the experimental data. The puzzling relationship between the transition temperature and the concentration of magnons is explained by their "relativistic" dispersion.

Journal Article↗
PubMed2001

Experimental evaluation of a cell module for hybrid liver support.

Aim of the study was to evaluate a hybrid liver support system in a porcine model of acute liver failure, after hepatectomy. Pigs with a body weight of 70+/-18 kg underwent total hepatectomy and porto-cavo-caval shunting as well as ligation of the bile duct and the hepatic artery. Control animals were connected to the system (including capillary membrane plasma separation) containing a four compartment bioreactor with integral oxygenation and decentralized mass exchange but without liver cells. The treatment group received hybrid liver support with the same system including 370+/-42 g primary isolated porcine parenchymal liver cells in co-culture with hepatocyte nursing cells, tissue engineered to liver- like structures at high density. Treatment started after complete recovery from anesthesia and was performed continuously. A positive influence on peripheral vascular resistance and a reduced need of catecholamine dosage was observed in the treatment group. Hybrid liver support with a cell module upscaled for clinical application significantly prolonged survival time in animals after hepatectomy with the longest survival being 26 hours in the control group an 57 hours in the treatment group.

Animals↗
PubMed2000

Enterohemorrhagic Escherichia coli (EHEC) strains of serogroup O118 display three distinctive clonal groups of EHEC pathogens.

A recent case report of a child infected with enterohemorrhagic Escherichia coli (EHEC) of serotype O118:H16 in Bavaria, in association with the isolation of a bovine O118 strain on the same farm (A. Weber, H. Klie, H. Richter, P. Gallien, M. Timm, and K. W. Perlberg, Berl. Muench. Tieraerztl. Wochenschr. 110:211-213, 1997), prompted us to investigate the relationship between bovine and human strains of serogroup O118. A total of 29 human O118 E. coli strains from Europe (21), Canada (4), and Peru (4) were compared by virulence typing and macrorestriction analysis with 7 bovine O118 EHEC strains isolated in Bavaria. Twenty-five of the human strains were characterized as EHEC. By serotyping and determination of the virulence-associated factors Shiga toxin (stx1 stx2 stx2 variants), intimin (eae), and EHEC hemolysin (Hly(EHEC)), three distinctive groups of O118 human pathogens were identified. Most of the strains belonged to serotype O118:H16, displaying the virulence traits Stx1, intimin, Hly(EHEC), and EspP/PssA (group 1). In addition, we identified strains of serotype O118:H12 (Stx2d only; group 2) and of serotype O118:H30 (Stx2 and intimin; group 3). Macrorestriction analysis with BlnI and XbaI revealed that all strains with a single O118 serotype profile (O118:H12, O118:H16, and O118:H30) belonged to one clonal cluster, irrespective of their origin. Group 1 strains clustered in the same clonal group as the bovine O118:H16 strains. Moreover, four pairs of strains of different origins and indistinguishable by all other methods applied were identified as group 1 strains. Our data support the direct transmission of an EHEC O118:H16 strain from a calf to a 2-year-old boy in the above-mentioned case report. Since bovine and human O118:H16 strains represent the same clones, they must be considered zoonotic EHEC pathogens. In contrast, EHEC strains of serotypes O118:H12 and O118:H30 have been isolated only from humans, indicating a reservoir for certain human O118 EHEC strains other than bovines.

Adhesins, Bacterial↗
PubMed1999

Bioreactors for hybrid liver support: historical aspects and novel designs.

A novel bioreactor construction has been designed for the utilization of hepatocytes and sinusoidal endothelial cells. The reactor is based on capillaries for hepatocyte aggregate immobilization. Three separate capillary membrane systems, each permitting a different function are woven in order to create a three dimensional network. Cells are perfused via independent capillary membrane compartments. Decentralized oxygen supply and carbon dioxide removal with low gradients are possible. The use of identical parallel units to supply hepatocytes facilitates scale up. In vitro studies demonstrate long-term external metabolic function in primary isolated hepatocytes within bioreactors. These systems are capable of supporting essential liver functions. Animal experiments have verified the possibility of scaling-up the bioreactors for clinical treatment. However, since there is no reliable animal model for investigation of the treatment of acute liver failure, the promising results obtained from these studies have limited relevance. The small number of clinical studies performed so far is not sufficient to reach conclusions about improvements in the therapy of acute liver failure. Although important progress has been made in the development of these systems, various hepatocyte culture models and bioreactor constructions are being discussed in the literature, which indicates competition in this field of medical research. An overview, which emphasizes the development of hepatocyte culture models for bioreactors, subsequent in vitro studies, animal studies, and clinical application, is also provided.

Animals↗
PubMed1999

Treatment of acute liver failure: hybrid liver support. A critical overview.

Hybrid liver support systems, which combine living cells of the liver in an extracorporeal circuit, have entered the first clinical trials in patients with acute liver failure. The goal of the different developments is to provide within a few hours a biological support of the patient's failing liver. Different technical solutions can be found to provide a sufficient functional mass of liver cells to the patient. Within this article, the biotechnical and clinical backgrounds of these developments are discussed, initial clinical results are summarized and an evaluation of this method as experimental treatment is given.

Animals↗
PubMed1998

Virulence properties of Shiga toxin-producing Escherichia coli (STEC) strains of serogroup O118, a major group of STEC pathogens in calves.

Shiga toxin-producing Escherichia coli (STEC) strains of serogroup 0118 are the most prevalent group among STEC strains in diarrheic calves in Germany (L. H. Wieler, Ph.D. thesis, University of Giessen, 1997). To define their virulence properties, 42 0118 (0118:H16 [n = 38] and 0118:H- [n = 4]) strains were characterized. The strains displayed three different Stx combinations (Stx1 [36 of 42], Stx1 and Stx2 [2 of 42], and Stx2 [4 of 42]). A total of 41 strains (97.6%) harbored a large virulence-associated plasmid containing hlyEHEC (hly from enterohemorrhagic E. coli). The strains' adhesive properties varied in relation to the eukaryotic cells tested. Only 28 of 42 strains (66.7%) showed localized adhesion (LA) in the human HEp-2 cell line. In contrast, in bovine fetal calf lung (FCL) cells, the number of LA-positive strains was much higher (37 of 42 [88.1%]). The locus of enterocyte effacement (LEE) was detected in 41 strains (97.6%). However, not all LEE-positive strains reacted positively in the fluorescence actin-staining (FAS) test, which indicated the attaching and effacing (AE) lesion. In HEp-2 cells, only 22 strains (52.4%) were FAS positive, while in FCL cells, the number of FAS-positive strains was significantly higher (38 of 42 [90.5%; P < 0.001]). In conclusion, the vast majority of the 0118 STEC strains from calves (41 of 42 [97.6%]) have a high virulence potential (stx, hlyEHEC, and LEE). This virulence potential and the high prevalence of STEC 0118 strains in calves suggest that these strains could be a major health threat for humans in the future. In addition, the poor association between results of the geno- and phenotypical tests to screen for the AE ability of STEC strains calls the diagnostic value of the FAS test into question.

Actins↗
PubMed1977

Optic disc neovascularization of uveal (choroidal or posterior ciliary) origin.

Fluorescein angiography during the choroidal phase of perfusion has been used to study the origin of blood vessels comprising neovascular tissue of the disc. These newly formed vessels were shown to derive their blood supply primarily from the uveal circulation rather than from the retinal circulation. This is related to the observation that many normal disc blood vessels originate from the choroidal or posterior ciliary circulation.

Adult↗
PubMed1976

Migratory white-without-pressure retinal lesions.

Nine patients had white-without-pressure retinal lesions. These lesions were seen in areas of vitreoretinal adhesions. The configuration and location of these lesions changed over variable periods of time. The cause of this pecular migration is unknown, but may be related to separation and re-creation of vitreoretinal adhesions. The migratory nature of white-without-pressure areas has not, to our knowledge, previously been reported in the literature.

Adolescent↗
PubMed1976

Acute choroidal ischemia as a complication of photocoagulation.

Acute choroidal vascular insufficiency as a complication of photocoagulation has been little noticed. In 17 eyes of 16 patients photocoagulated with either xenon or argon sources for proliferative sickle cell retinopathy, gray lesions of the fundus developed peripheral to the photocoagulation sites. Histologic examination of similar gray lesions produced in monkeys showed necrosis and atrophy of the outer half of the retina. Intense photocoagulation of the human fundus, even with smaller spot sizes, may occlude a choroidal artery, producing separate gray lesions of distinctive shape. The lesions in both the patients and the monkeys progressed to granular hyperpigmentation by two to three weeks after photocoagulation.

Adolescent↗
PubMed1976

Macular and perimacular vascular remodelling sickling haemoglobinopathies.

The posterior pole vasculature of 100 patients with different sickling haemoglobinopathies was studied prospectively over a period of three years. Various abnormalities of the posterior pole vasculature were seen in 29 per cent of the patients. Continuous remodelling of the macular and perimacular vasculature occurred. Visual acuity was variably affected and sometimes remained intact.

Adolescent↗
PubMed1975

Peripheral retinal microaneurysms in chronic leukemia.

Of 25 patients with chronic leukemia, there was clinical evidence of peripheral retinal microaneurysm formation in two of eight patients with chronic lymphocytic leukemia and six of 17 patients with chronic myelogenous leukemia. There was no proliferative retinopathy in any of the 25 patients. An elevated leukocyte count seemed necessary for microaneurysm formation in leukemia, although some patients with elevated counts had no microaneurysms. The prolonged leukocytosis of chronic leukemia can produce peripheral capillary dropout, vascular stagnation, microaneurysm formation, and, rarely, peripheral proliferative retinopathy similar to sickle cell disease.

Adult↗