PubMed Health⌕ Search

Biomedical subjects

M Beck

Publications and source records attributed to M Beck.

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

[Typing of the apx toxin gene of Actinobacillus pleuropneumoniae using PCR].

For the determination of the apx toxin genes in Actinobacillus pleuropneumoniae strains, five PCR reactions were developed which allow the detection of the activator and structural genes and the secretion genes of the toxins ApxI, ApxII and ApxIII. The oligonucleotide primers were chosen in order to amplify characteristic parts of the activator and structural genes apxICA, apxIICA and apxIIICA, and the secretion genes apxIBD and apxIIIBD. The annealing temperature of all five reaction was identical in order to allow the five reactions in a single PCR run. The differences in length between the individual amplified gene fragments allowed all product fragments to be separated in a single electrophoresis. This way, a typical toxin gene pattern could be obtained which is characteristic for the five toxin gene groups of A. pleuropneumoniae including serotypes 1, 5a, 5b, 9 and 11 (group 1), serotypes 2, 4, 6 and 8 (group 2), serotype 3 (group 3), serotypes 7 and 12 (group 4), and serotype 10 (group 5). The identification of the toxin genes, which have significance in virulence, enhance and facilitate differentiation of A. pleuropneumoniae and allow the detection of serotypes with an atypical toxin pattern.

Actinobacillus pleuropneumoniae↗
PubMed1996

Mucopolysaccharidosis type II (Hunter syndrome): mutation "hot spots" in the iduronate-2-sulfatase gene.

Mucopolysaccharidosis type II (MPS II, Hunter syndrome) is an X-chromosomal storage disorder due to deficiency of the lysosomal enzyme iduronate-2-sulfatase (IDS). We have identified IDS mutations in a total of 31 families/patients with MPS II, of which 20 are novel and unique and a further 1 is novel but has been found in 3 unrelated patients. One of the mutations detected is of special interest as an AG-->G substitution in an intron, far apart from the coding region, is deleterious by creating a new 5'-splice-donor site that results in the inclusion of a 78-bp intronic sequence. While the distribution of gene rearrangements (deletions, insertions, and duplications) of <20 bp seems to be random over the IDS gene, the analysis of a total of 101 point mutations lying within the coding region shows that they tend to be more frequent in exons III, VIII, and IX. Forty-seven percent of the point mutations are at CpG dinucleotides, of which G:C-to-A:T transitions constitute nearly 80%. Almost all recurrent point mutations involve CpG sites. Analysis of a collective of 50 families studied in our laboratory, to date, revealed that mutations occur more frequently in male meioses (estimated male-to-female ratio between 3.76 and 6.3).

Alternative Splicing↗
PubMed1995

Mitral and aortic regurgitation in 84 patients with mucopolysaccharidoses.

UNLABELLED: In echocardiographic and necropsy studies nodular thickening of the mitral valve and, less frequently, of the aortic valve has been found in 60%-90% of patients with mucopolysaccharidoses (MPS). Little is known about the haemodynamic consequences of these morphological changes. In this study 84 unselected patients with different enzymatically proven MPS and 84 age and sex matched, healthy persons were studied prospectively by colour Doppler flow mapping. The patients' age ranged from 1 to 47 years (median 8.1 years). Mitral and aortic regurgitation were defined as a holosystolic or holodiastolic jet originating from the valve into the left atrium or the left ventricular outflow tract, respectively, with peak velocities exceeding 2.5 m/s. Of the 84 patients with satisfactory studies, mitral regurgitation was detected in 64.3% and aortic regurgitation in 40.5%, respectively. Regurgitation was severe in 4.8% of mitral valves and 8.3% of aortic valves. The frequency of aortic and/or mitral regurgitation was 75% in all patients, 89% in MPS I, 94% in MPS II, 66% in MPS III, 33% in MPS IV, and 100% in MPS VI. Combined mitral and aortic regurgitation was present in 29% of our patients. None of the control persons showed mitral or aortic regurgitation. CONCLUSION: Aortic and mitral regurgitation are more frequent in patients with MPS than previously thought and that therefore these patients should have regular colour Doppler flow mapping and antibiotic prophylaxis when required.

Adolescent↗
PubMed1995

Reactions to other corticosteroids in patients with positive patch test reactions to budesonide.

BACKGROUND: Corticosteroid cross-reactions have been classified into four well-defined groups. A previous study of patch test reactions to other corticosteroids in patients allergic to hydrocortisone failed to conform to these groups. It was suggested that substitution at the C6 and C9 positions of the corticosteroid was the most important determinant of a further reaction. OBJECTIVE: Our aim was to analyze multiple positive patch tests to corticosteroids in patients sensitized to budesonide to confirm our earlier findings. METHODS: Forty-six patients with positive patch tests to budesonide were patch-tested to 17 other topical corticosteroids. The results were examined by a generalized linear model and a chi-square test. RESULTS: Substitution of the corticosteroid at the C6 and C9 positions significantly reduced the number of reactions. A different substitution at the C16 and C17 positions was less important, and that at the C21 position was of no significance. CONCLUSIONS: Patients sensitized to budesonide are most likely to react to other non-C6 and non-C9 substituted corticosteroids.

Adrenal Cortex Hormones↗
PubMed1995

Development of an efficient PCR method for toxin typing of Actinobacillus pleuropneumoniae strains.

A method has been developed which allows the determination of the activator, the structural and the secretion genes of the three toxins ApxI, ApxII and ApxIII in Actinobacillus pleuropneumoniae in only two PCR reactions. The oligonucleotide primers were designed to amplify a significant part of the activator and structural genes apxICA, apxIICA and apxIIICA together in a single PCR reaction giving amplification products which differ in length, in order to be clearly separated by agarose gel electrophoresis. Variations in the apxIA and apxIIIA genes which were found in different serotypes were taken into account in the design of the primers to give a uniform amplification product for both variants of the apxIA and the apxIIIA genes. The secretion genes apxIBD and apxIIIBD are also detected in a single PCR reaction containing two pairs of oligonucleotide primers which yield two differently sized fragments to differentiate between apxIBD and apxIIIBD genes. The reference strains of A. pleuropneumoniae serotypes 1-12 and 104 field strains representing all serotypes obtained from various laboratories worldwide were analysed for their content of apx genes. The two PCR reactions give toxin gene patterns which are characteristic for different groups of serotypes in A. pleuropneumoniae and allow the rapid differentiation of five toxin type groups, group 1 including serotypes 1, 5a, 5b, 9 and 11, group 2 including serotypes 2, 4, 6, 8, group 3 with serotype 3, group 4 with serotype 7 and 12 and group 5 with serotype 10. The method enhances and facilitates differentiation of A. pleuropneumoniae strains for diagnostics and epidemiology and allows the detection of serotypes with atypical toxin patterns.

Actinobacillus pleuropneumoniae↗
PubMed1995

Histopathologic effects of kinetic cavity preparation for the removal of enamel and dentin. An in vivo animal study.

Recent developments in technology, direct placement restorative materials, and cavity preparation design have renewed interest in kinetic cavity preparation, a term to describe the use of air-abrasion for removal of tooth structure. This study compared the pulpal response of 120 teeth in mixed-breed dogs treated with four kinetic cavity preparation combinations of pressure (80 psi and 160 psi) and aluminum oxide particle sizes (27 microns and 50 microns) to those treated with high-speed rotary burs. Class V buccal preparations were made and restored with an interim material. Teeth were collected 72 hours after surgery, decalcified, sectioned, stained with hematoxylin and eosin, and blindly evaluated by two examiners at the minimal dentin thickness. Samples were graded for extent of displacement, disruption, inflammation, and necrosis of pulpal structures. Differences between groups were analyzed with the use of Bonferroni-adjusted multiple Mann-Whitney-Wilcoxon tests with p < 0.05 being significant. Higher pressures and smaller particles yielded significantly fewer pulpal effects than the high-speed treated teeth whereas lower pressures and larger particles were not significantly different for most effects evaluated. No adverse soft tissue effects were noted when kinetic cavity preparation was directed at attached gingiva.

Air Pressure↗
PubMed1995

Inter- and intrafamilial variability in mucolipidosis II (I-cell disease).

In this paper nine patients with mucolipidosis II (I-cell disease) are described. They had clinical features commonly found in mucolipidosis II, including disproportionate dwarfism, coarse facial features and mental retardation. However, there was remarkable variability in age of onset, organ manifestation and radiological findings. Some had unusual clinical symptoms including pericardial effusion and profound brain atrophy. Striking differences in phenotypic expression were also seen in two affected siblings. Clinical heterogeneity is observed not only in mucolipidosis II but also in many other lysosomal storage disorders. The factors that may contribute to this clinical diversity are discussed.

Age of Onset↗
PubMed1995

[In-vitro stability of rotator cuff repair techniques].

Rotator cuff repair techniques were examined in vitro. First, the mechanical properties of nine different tendon-grasping techniques were compared using 159 normal infraspinatus sheep tendons. The clinically most frequently used simple stitch and mattress suture failed at low-to-moderate loads (two stitches, 184 N and 269 N) with the sutures pulling out of the tendons. A modification of the Mason-Allen grasping technique improved the ultimate tensile strength to 359 N (two stitches) without allowing relevant gap formation. Augmentation with synthetic materials did not improve the mechanical properties of the tendon-grasping techniques tested. The mechanical properties of different anchoring techniques to bone were assessed using osteoporotic bone specimens with mechanical properties comparable to those of proximal humeri with long-standing cuff defects. Single as well as double transosseous suture fixation (139 N and 146 N) and suture anchor fixation (142 N) were weak. Tying the knots over a plate-like cortical bone augmentation device improved the failure strength to 329 N. Some of these data were presented in the English literature in 1994. Considering the excellent preliminary experience in the clinical application of the modified Mason-Allen grasping technique and cortical augmentation, it seemed appropriate to present them in German as well.

Animals↗
PubMed1995

Family violence.

Explore the source record for details and available documents.

Adult↗
PubMed1995

[Violent patients. A problem for the therapist in psychiatric clinics?].

At four psychiatric hospitals, 128 doctors, 50 psychologists and 55 social workers were asked to complete a questionnaire about their experience with aggressive patients. Fifty-five percent reported having been assaulted seriously during their career; physical assaults during the last year had occurred for 29%. Forty-nine percent had experienced a situation judged as fairly or very dangerous. Women were concerned less than men, social workers less than psychologists and doctors.

Aggression↗
PubMed1995

Role of larval cadavers in recycling processes of Bacillus sphaericus.

The influence of larval cadavers of Culex pipiens on recycling processes of Bacillus sphaericus was investigated by bioassays and spore counts in the laboratory. Studies conducted with 3 different B. sphaericus concentrations (0.005, 0.01, 0.05 mg B. sphaericus/liter) indicated that the presence of cadavers in the water contributed to the maintenance of toxic levels of B. sphaericus. Larval cadavers seem to contain all the nutrients necessary both for vegetative multiplication and for toxin synthesis associated with the sporulation process. Bioassays of B. sphaericus revealed that the mortality of Culex pipiens remained on a high level over a period of 26 days when larval cadavers were added every second day to the test vessels. This result was supported by a sharp increase in spore density when cadavers were added at the same interval. The test series showed B. sphaericus recycles in intact cadavers of Culex pipiens, whereas this phenomenon could not be observed when crushed cadavers were used in the trials. Therefore, our results demonstrated that for successful recycling processes it seems of crucial importance that infected cadavers remain intact at least for a certain time and also that the dosage of the applied B. sphaericus plays a major role in recycling processes whereas larval density is only of minor importance to these processes.

Animals↗
PubMed1994

Proteoglycan synthesis by cultured human chondrocytes.

Iliac crest biopsies are important in the detection of human skeletal dysplasias. Therefore, culture of these cells may serve as a valuable method for studying proteoglycan metabolism in chondrocytes of individuals with skeletal abnormalities. Morphological and biochemical studies were performed on human iliac crest chondrocytes grown in monolayer and in agarose gels. Two proteoglycan populations of different hydrodynamic size and glycosaminoglycan composition were synthesized by cells grown in monolayer. Chondrocytes cultured in an agarose gel for 2 weeks synthesized proteoglycans identical to those of the native tissue with respect to hydrodynamic size and glycosaminoglycan chain length. However, the ratio of chondroitin-6-sulfate to chondroitin-4-sulfate was higher than in the native tissue. This ratio was not influenced by different sulfate concentrations in the medium. Moreover, treatment with ascorbic acid did not influence proteoglycan synthesis; however, there was a pericellular accumulation of proteoglycans.

Ascorbic Acid↗
PubMed1994

Prenatal diagnosis and carrier detection in mucopolysaccharidosis type II by mutation analysis. A 47,XXY male heterozygous for a missense point mutation.

Identification of iduronate-2-sulphatase (IDS) gene mutations in patients with mucopolysaccharidosis type II (MPS II, Hunter syndrome) allows fast and reliable carrier detection and prenatal diagnosis. We describe here three cases of prenatal diagnosis by direct detection of the gene mutation. In addition to two affected male fetuses from two different families, a 47,XXY fetus carrying both the normal and the mutant allele was diagnosed in a third family. The latter pregnancy was carried to term and the child is obviously not affected by MPS II.

Alleles↗
PubMed1994

Riedel's thyroiditis associated with high titers of antimicrosomal and antithyroglobulin antibodies and hypothyroidism.

Riedel's thyroiditis is a rare, chronic inflammatory disease of the thyroid gland. The aggressive fibrosis with extension beyond the thyroid into adjacent tissues contrasts with the diffuse, but intracapsular fibrosis of Hashimoto's thyroiditis. Most current studies refute the possibility of progression from a highly fibrosing form of Hashimoto's thyroiditis to a Riedel's thyroiditis based on the distinct clinical and laboratory data, although an unknown immunological basis is suggested for both diseases. The authors describe a patient with Riedel's thyroiditis, probably associated with Hashimoto's thyroiditis, sent to surgery because her cytological examination suggested thyroid malignancy. This patient had clinical and laboratory features of hypothyroidism and very high titers of antimicrosomal and antithyroglobulin antibodies, which decreased after surgery. Pathology studies disclosed Riedel's thyroiditis with intense lymphocytic infiltration suggestive of Hashimoto's thyroiditis. Quantitative immunohistochemical studies were not able to distinguish between both diseases.

Adult↗
PubMed1994

Mucopolysaccharidosis type I: identification of 8 novel mutations and determination of the frequency of the two common alpha-L-iduronidase mutations (W402X and Q70X) among European patients.

A group of 46 European patients with mucopolysaccharidosis type I (MPS I) was screened for mutations of the alpha-L-iduronidase gene. The 2 common nonsense mutations, W402X and Q70X, were identified in, respectively, 37% and 35% of mutant alleles. Considerable differences were seen in the frequency of these 2 mutations in patients from North Europe (Norway and Finland) and other European countries (mainly The Netherlands and Germany). In Scandinavia, W402X and Q70X account for 17% and 62% of the MPS I alleles, respectively, while in other European countries W402X is about 2.5 times more frequent (48%) than Q70X (19%). Eight novel mutations are described including 4 missense mutations, 1 nonsense mutation, 1 insertion of 2 base pairs, and 2 deletions of 1 and 12 base pairs.

Alleles↗
PubMed1994

RTX toxin genotypes and phenotypes in Actinobacillus pleuropneumoniae field strains.

Actinobacillus pleuropneumoniae serotype reference strains and 204 A. pleuropneumoniae field strains representing all 12 serotypes and both biovars 1 and 2, obtained from laboratories from various countries worldwide, were analyzed for the presence of the toxin genes apxIC, apxIA, apxIB, apxID, apxIIC, apxIIA, apxIIIC, apxIIIA, apxIIIB, and apxIIID by DNA-DNA hybridization with specific gene probes. Expression of the toxins ApxI, ApxII, and ApxIII was assessed by immunoblot analysis with monoclonal antibodies. The results show that the patterns of apx genes and those of the expressed Apx toxins in biovar 1 field strains are the same as those of the genes and toxins of corresponding serotype reference strain. We found only three strains which had certain apx genes missing compared with the genes in their serotype reference strains. Analysis of the expression of the three toxins showed that nearly all strains expressed their apx genes and produced the same Apx toxins as their serotype reference strain. We found only one strain that did not produce ApxI, although it contained the apxICABD genes, and one strain which did not express ApxII but which contained apxIICA. Several field strains which initially showed that their serotype did not correspond to the apx gene profile of the reference strain and which had an unexpected virulence for the given serotype revealed that their initial serotyping was erroneous. We show that the apx gene profiles are inherent to a given serotype. The method cannot differentiate between all 12 serotypes. However, it allowed us to distinguish five groups of toxin gene patterns which showed pathological, toxicological, and epidemiological significance. None of the biovar 2 strains contained apxIII genes. The apxI and apxII genes in the biovar 2 strains, however, were the same as those found in the serotype reference strains of biovar 1.

Actinobacillus pleuropneumoniae↗