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Biomedical subjects

R Herrmann

Publications and source records attributed to R Herrmann.

At least 55 records · Page 3Linked to original sources
PubMed2001

Differences between the quantitative antigenemia assay and the cobas amplicor monitor quantitative PCR assay for detecting CMV viraemia in bone marrow and solid organ transplant patients.

The relationship between quantitative PCR (COBAS Amplicor CMV Monitor, Roche Diagnostics) and quantitative antigenemia (Monofluor pp65, Sanofi Diagnostics) was examined for monitoring CMV viraemia. A total of 469 specimens from immunocompromised haematology and solid organ transplant patients were tested by quantitative antigenemia and qualitative PCR. Quantitative PCR (QPCR) was performed on the 245 specimens in which CMV DNA was detected by qualitative PCR. To exclude any effect due to specific anti-CMV treatment, analysis of antigenemia and QPCR results was only performed on the 164 of 245 specimens collected from patients not on ganciclovir or foscarnet treatment. Forty seven specimens had <400 CMV copies/mL and a negative antigen result, four specimens were antigen positive (all between 1 to 10 positive CMV cells/2 x 10(5) leucocytes) and had <400 CMV copies/mL. Fifty-one specimens had a CMV viral load > or = 400 copies/mL and a negative antigen result and 62 specimens had a CMV viral load > or = 400 copies/mL and a positive antigen. The viral load was shown to be as high as 43,000 copies/mL in some patients with a negative antigen and occurred in non-neutropenic patients. The correlation coefficient for antigen and QPCR results for specimens from bone marrow transplant patients, was 0.69 with an average CMV viral load of 3,200 copies/mL (SEM = 800) and an average antigen of nine positive CMV cells/2 x 10(5) leucocytes (SEM = 3). In the corresponding solid organ transplant group, the correlation coefficient for antigen and QPCR results was 0.71 with an average CMV viral load of 9,900 copies/mL (SEM = 2,100) and an average antigen of 26 positive CMV cells/2 x 10(5) leucocytes (SEM = 6). Both the average viral load and the average antigen result in specimens from solid organ transplant patients, were significantly higher than the average viral load and antigen result in the corresponding group of bone marrow transplant patients (Two-Sample-for-Means z-Test, P = 0.001 and P = 0.003, respectively). The differences in the kinetics of the two assays in monitoring CMV and their ability to predict CMV disease was also assessed in a sub-group of patients. In conclusion, the two assays used in this study do not always show parallel changes in CMV viral load, but may be complementary for the diagnosis and management of CMV disease. The observation that non-neutropenic patients can have a high viral load in plasma and a negative antigenemia has implications for laboratories using antigenemia alone to monitor patients for CMV disease.

Antigens, Viral↗
PubMed2001

Chemotherapy for malignant brain tumors of astrocytic and oligodendroglial lineage.

To date, surgery and irradiation remain the standard therapies for anaplastic astrocytoma (AA, WHO grade III) and glioblastoma multiforme (GBM, WHO grade IV). Due to infiltrative tumor growth a complete surgical resection is never achieved and more than 90% of the tumors will recur within 2 cm of the primary tumor location. Postoperative radiotherapy prolongs survival but is not curative and prognosis remains poor with only a few patients being alive 2 years after diagnosis. Over the past decades multiple trials dealt with the question of whether chemotherapy (CT) may influence the outcome of malignant brain tumor patients. In general, the results have been disappointing with one exception: chemosensitivity and prolonged survival after CT have been demonstrated for tumors of oligodendrogial lineage. Drugs showing some activity in malignant brain tumors and therapeutic concepts will be discussed.

Antineoplastic Agents↗
PubMed2001

Characterisation of organic matter from anaerobic digestion of organic waste by aerobic microbial activity.

The aim of this study was to examine whether the characterisation of organic matter on the basis of an oxygen uptake rate (OUR) could be applied to organic waste from an anaerobic waste treatment process. Three anaerobic digestion experiments were carried out in a bioreactor. Volatile fatty acids (VFA) and dissolved organic carbon (DOC) were monitored. OUR-experiments were carried out with diluted samples from the process. The graphs of the OUR-experiments showed a clear lag-phase, which was due to the slow adaptation of aerobic microorganisms. Model simulations of the OUR versus time curve showed sufficient agreement, if based on one fraction of readily biodegradable and two fractions of less easily biodegradable organic matter. The shape of the simulated graphs was affected considerably by the value of the maintenance energy requirement rate qm and could be improved by reducing the standard value qm = 1 d(-1) to qm = 0.1 d(-1). Only little agreement was achieved when comparing the results of the OUR-experiments with the VFA- and DOC-concentrations. Experiments with additional trace elements and vitamins led to an increase in the OUR and proved that the oxygen consumption was not exclusively determined by the availability of organic matter.

Aerobiosis↗
PubMed2001

Autosomal dominant distal myopathy: further evidence of a chromosome 14 locus.

In 1995 Laing et al. (Am J Hum Genet 56(1995)422) described a single family with nine members affected by an autosomal dominant infantile onset distal myopathy. This family generated a LOD score of 2.6 for a locus on chromosome 14. We describe two families with an infantile onset distal myopathy: a new family with four affected members and the family previously described by Scoppetta et al. (Acta Neurol Scand 92(1955)122) in both of which haplotype segregation was compatible with linkage to the same chromosome 14 locus, generating LOD scores of 0.9 at a penetrance of 100% for the markers D14S283 and D14S64 (theta=0) in both families. The loci for autosomal recessive hereditary inclusion body myopathy and Nonaka myopathy on chromosome 9 and for autosomal dominant distal myopathy of Markesberry-Griggs and Udd on chromosome 2q31-33 were excluded by linkage analysis. The disease followed a uniform course with selective wasting of the anterior tibial muscles, starting in infancy and recognizable by a characteristic clinical sign of the 'hanging big toe'. This was followed by slow progression, with involvement of the finger and wrist extensor muscles in the third decade and proximal limb muscles in the fourth decade. Interestingly, we also found evidence of an accompanying mild peripheral neuropathy in the oldest individual with hypomyelination of numerous large myelinated fibres. In addition, this patient's muscle biopsy also showed autophagic vacuoles and numerous intranuclear tubulo-filamentous inclusions of 15-20 nm diameter. Given that all three families with infantile onset distal myopathy are compatible with linkage to the same locus on chromosome 14, this study supports evidence for, and enlarges the clinical and neuropathological spectrum of the distal myopathy on chromosome 14.

Adolescent↗
PubMed2001

Muscular dystrophy and neuronal migration disorder caused by mutations in a glycosyltransferase, POMGnT1.

Muscle-eye-brain disease (MEB) is an autosomal recessive disorder characterized by congenital muscular dystrophy, ocular abnormalities, and lissencephaly. Mammalian O-mannosyl glycosylation is a rare type of protein modification that is observed in a limited number of glycoproteins of brain, nerve, and skeletal muscle. Here we isolated a human cDNA for protein O-mannose beta-1,2-N-acetylglucosaminyltransferase (POMGnT1), which participates in O-mannosyl glycan synthesis. We also identified six independent mutations of the POMGnT1 gene in six patients with MEB. Expression of most frequent mutation revealed a great loss of the enzymatic activity. These findings suggest that interference in O-mannosyl glycosylation is a new pathomechanism for muscular dystrophy as well as neuronal migration disorder.

Amino Acid Sequence↗
PubMed2001

Risk factors for congenital umbilical hernia in German Fleckvieh.

Risk factors for congenital umbilical hernias were investigated in German Fleckvieh calves up for sale at livestock markets. Data from 53,105 calves were collected from 77 livestock auctions in 1996 and 1997. The overall incidence of congenital umbilical hernia was 1.8%. A significant influence on incidence was exerted by the sex of the calf, the occurrence of multiple births, the market place/market date, the sire and the sire line. The proportion of Red Holstein blood in the calf, the dam's lactation number, gestation length, 305 day milk performance and the herd milk level were not significant factors. Herdmate averages for calves differed significantly in their incidence. Heritability estimates on the liability scale for congenital umbilical hernia were about 0.4 and progeny groups of sires at risk for congenital umbilical hernia were in the range 0.1% to 14.2%. The segregation pattern could not be explained either by an autosomal recessive or by an autosomal dominant monogenic model. It seems likely that more than one gene locus is involved in the underlying genetic mechanism. Breeders should be aware of the genetic implications of congenital umbilical hernias.

Animals↗
PubMed2001

Defining the mycoplasma 'cytoskeleton': the protein composition of the Triton X-100 insoluble fraction of the bacterium Mycoplasma pneumoniae determined by 2-D gel electrophoresis and mass spectrometry.

After treating Mycoplasma pneumoniae cells with the nonionic detergent Triton X-100, an undefined, structured protein complex remains that is called the 'Triton X-100 insoluble fraction' or 'Triton shell'. By analogy with eukaryotic cells and supported by ultrastructural analyses it is supposed that this fraction contains the components of a bacterial cytoskeleton-like structure. In this study, the composition of the Triton X-100 insoluble fraction was defined by electron microscopic screening for possible structural elements, and by two-dimensional (2-D) gel electrophoresis and MS to identify the proteins present. Silver staining of 2-D gels revealed about 100 protein spots. By staining with colloidal Coomassie blue, about 50 protein spots were visualized, of which 41 were identified by determining the mass and partial sequence of tryptic peptides of individual proteins. The identified proteins belonged to several functional categories, mainly energy metabolism, translation and heat-shock response. In addition, lipoproteins were found and most of the proteins involved in cytadherence that were previously shown to be components of the Triton X-100 insoluble fraction. There were also 11 functionally unassigned proteins. Based on sequence-derived predictions, some of these might be potential candidates for structural components. Quantitatively, the most prevalent proteins were the heat-shock protein DnaK, elongation factor Tu and subunits alpha and beta of the pyruvate dehydrogenase complex (PdhA, PdhB), but definite conclusions regarding the composition of the observed structures can only be drawn after specific proteins are assigned to them, for example by immunocytochemistry.

Bacterial Proteins↗
PubMed2000

Transcription in Mycoplasma pneumoniae.

Very little is understood of the structure of mycoplasma promoters, and this limits interpretation of genomic sequence data in these species. In this study the transcriptional start points of 22 genes of Mycoplasma pneumoniae were identified and the regions 5' to the start point compared. Although a strong consensus -10 region could be seen, there was only a weak consensus in the -35 region. A high proportion of transcripts had heterogeneous 5'-ends and characterisation of the sequence of the 5'-ends of two transcripts established that the heterogeneity was derived from initiation of transcription at reduced levels between 1 and 4 bases 5' to the major starting point. In addition to this apparently unique feature, a high proportion of transcripts lacked a 5' untranslated leader region that could contain a ribosomal binding site. Such leaderless transcripts are seen rarely in other bacterial species. Although the promoter regions for a number of members of lipoprotein multigene families were examined, no obvious explanation for regulation of expression was apparent. Using the data from this study an improved matrix for prediction of M.pneumoniae promoters was derived. Application of this matrix to the sequences immediately 3' and 5' to each predicted start codon in the genome suggested that most M. pneumoniae transcriptional start points were likely to occur between 5 and 30 bases 5' to the start codon.

Base Composition↗
PubMed2000

[Hand-foot syndrome (palmar-plantar erythrodysesthesia].

The hand-foot syndrome (HFS) is an erythematous skin lesion of the palma and planta of the hand and feet is most often caused by cytostatic chemotherapy. The impact on the patients' quality of life depends on the extent of the disease. The pathogenesis of the hand-foot syndrome has not yet been sufficiently clarified and it can only be treated symptomatically. We performed an extensive literature search in Medline to evaluate the current state of knowledge concerning the hand-foot syndrome and conclude with practical advice to physicians treating patients with hand-foot syndrome.

Antineoplastic Agents↗
PubMed2000

Dissociation of the dystroglycan complex in caveolin-3-deficient limb girdle muscular dystrophy.

Limb girdle muscular dystrophy is a group of clinically and genetically heterogeneous disorders inherited in an autosomal recessive or dominant mode. Caveolin-3, the muscle-specific member of the caveolin gene family, is implicated in the pathogenesis of autosomal dominant limb girdle muscular dystrophy 1C. Here we report on a 4-year-old girl presenting with myalgia and muscle cramps due to a caveolin-3 deficiency in her dystrophic skeletal muscle as a result of a heterozygous 136G-->A substitution in the caveolin-3 gene. The novel sporadic missense mutation in the caveolin signature sequence of the caveolin-3 gene changes an alanine to a threonine (A46T) and prevents the localization of caveolin-3 to the plasma membrane in a dominant negative fashion. Caveolin-3 has been suggested to interact with the dystrophin-glycoprotein complex, which in striated muscle fibers links the cytoskeleton to the extracellular matrix and with neuronal nitric oxide synthase. Similar to dystrophin-deficient Duchenne muscular dystrophy, a secondary decrease in neuronal nitric oxide synthase and alpha-dystroglycan expression was detected in the caveolin-3-deficient patient. These results implicate an important function of the caveolin signature sequence and common mechanisms in the pathogenesis of dystrophin-glycoprotein complex-associated muscular dystrophies with caveolin-3-deficient limb girdle muscular dystrophy.

Amino Acid Substitution↗
PubMed2000

Re-annotating the Mycoplasma pneumoniae genome sequence: adding value, function and reading frames.

Four years after the original sequence submission, we have re-annotated the genome of Mycoplasma pneumoniae to incorporate novel data. The total number of ORFss has been increased from 677 to 688 (10 new proteins were predicted in intergenic regions, two further were newly identified by mass spectrometry and one protein ORF was dismissed) and the number of RNAs from 39 to 42 genes. For 19 of the now 35 tRNAs and for six other functional RNAs the exact genome positions were re-annotated and two new tRNA(Leu) and a small 200 nt RNA were identified. Sixteen protein reading frames were extended and eight shortened. For each ORF a consistent annotation vocabulary has been introduced. Annotation reasoning, annotation categories and comparisons to other published data on M.pneumoniae functional assignments are given. Experimental evidence includes 2-dimensional gel electrophoresis in combination with mass spectrometry as well as gene expression data from this study. Compared to the original annotation, we increased the number of proteins with predicted functional features from 349 to 458. The increase includes 36 new predictions and 73 protein assignments confirmed by the published literature. Furthermore, there are 23 reductions and 30 additions with respect to the previous annotation. mRNA expression data support transcription of 184 of the functionally unassigned reading frames.

Amino Acid Sequence↗
PubMed2000

Association of nonsense mutation of dystrophin gene with disruption of sarcoglycan complex in X-linked dilated cardiomyopathy.

BACKGROUND: In a systematic analysis of inherited forms of cardiomyopathy, we previously identified a family with X-linked dilated cardiomyopathy characterised by a mutation in the rod region of dystrophin. We have now attempted to eludicate the genetic mechanism involved in this disease, as well as the role of dystrophin-associated glycoproteins. METHODS: The affected dystrophin epitope, which lacks binding to the dys-1 antibody, was analysed by single-strand conformation polymorphism analysis, reverse-transcription PCR, and DNA sequencing. Effects on dystrophin-associated glycoproteins were studied by immunohistochemistry and western blotting. FINDINGS: A translation-termination mutation (C4148T) in exon 29 of the dystrophin gene was found in all affected family members. Alternative splicing rescued the reading frame and led to the expression of a dystrophin molecule lacking 50 aminoacids both in cardiac and skeletal muscle. Immunohistochemical analysis of the dystrophin-associated proteins revealed a reduction of beta-sarcoglycan and delta-sarcoglycan in the sarcolemma of cardiac muscle but not skeletal muscle tissue. However, western blotting revealed similar amounts of sarcoglycan subunits in both tissues. INTERPRETATION: The molecular mechanism of this subtype of X-linked cardiomyopathy may be explained by a conformational change in exon-29-deleted dystrophin, resulting in disruption of the sarcoglycan assembly in heart muscle but not skeletal muscle.

Cardiomyopathy, Dilated↗
PubMed2000

Diagnosis and treatment of intravascular lymphomatosis.

OBJECTIVE: To describe a patient with unusually good outcome of a rare, high-grade lymphoma that often involves the nervous system. DESIGN: Case report. SETTING: University hospital. CASE: A 70-year-old pharmacist first presented with meningoencephalitislike symptoms and 6 months later with acute confusional state followed by complex partial status epilepticus. Diagnosis of intravascular lymphomatosis was made using detection and biopsy of a bilateral adrenal tumor. MAIN OUTCOME AND RESULTS: Polychemotherapy consisting of CHOP (cyclophosphamide, doxorubicin hydrochloride, vincristine sulfate, and prednisone) led to complete remission. The patient's survival time currently exceeds 21/2 years. CONCLUSIONS: The possibility of intravascular lymphomatosis should be considered in adult patients with unclear meningoencephalitic syndrome, acute confusional state, dementia, or other unexplained neurologic conditions with signs of a systemic disease. In intravascular lymphomatosis, as in other high-grade non-Hodgkin lymphomas, CHOP polychemotherapy should be the standard treatment.

Aged↗
PubMed2000

Towards a two-dimensional proteome map of Mycoplasma pneumoniae.

A Proteome map of the bacterium Mycoplasma pneumoniae was constructed using two-dimensional (2-D) gel electrophoresis in combination with mass spectrometry (MS). M. pneumoniae is a human pathogen with a known genome sequence of 816 kbp coding for only 688 open reading frames, and is therefore an ideal model system to explore the scope and limits of the current technology. The soluble protein content of this bacterium grown under standard laboratory conditions was separated by 1-D or 2-D gel electrophoresis applying various pH gradients, different acrylamide concentrations and buffer systems. Proteins were identified using liquid chromatography-electrospray ionization ion trap and matrix-assisted laser desorption/ionization-MS. Mass spectrometric protein identification was supported and controlled using N-terminal sequencing and immunological methods. So far, proteins from about 350 spots were characterized with MS by determining the molecular weights and partial sequences of their tryptic peptides. Comparing these experimental data with the DNA sequence-derived predictions it was possible to assign these 350 proteins to 224 genes. The importance of proteomics for genome analysis was shown by the identification of four proteins, not annotated in the original publication. Although the proteome map is still incomplete, it is already a useful reference for comparative analyses of M. pneumoniae cells grown under modified conditions.

Acrylic Resins↗
PubMed2000

Ultrasonic monitoring of zeolite synthesis in real time

Variations of the phase and amplitude of a transmitted ultrasonic wave package were monitored in real time during the synthesis of zeolite A and zeolite X. For both materials, characteristic changes of the measured attenuation and the sound velocity of ultrasonic waves traveling in the reaction fluid were observed, correlating with the processes of gel formation and zeolite crystallization, respectively. Aging effects of the reaction fluids are demonstrated. The observation of the onset of the zeolite crystallization was verified with ex-situ X-ray diffraction (XRD) measurements.

Journal Article↗
PubMed2000

A unique structural abnormality of chromosome 16 resulting in a CBF beta-MYH11 fusion transcript in a patient with acute myeloid leukemia, FAB M4.

A 43-year-old female with a peripheral white cell count of 118.0 x 10(9)/L and 96% blasts was diagnosed with acute myeloid leukemia (AML), FAB M4. Cytogenetics, performed on a bone marrow sample, revealed the following abnormal karyotype: 46,XX,ins(16)(q22p13.1p13. 3). Fluorescence in situ hybridization (FISH) confirmed the inter-arm insertion using a probe for 16p. The result of this structural rearrangement was the fusion of CBF beta to MYH11 seen commonly in inv(16)(p13q22). The patient commenced high-dose intensive combination chemotherapy (big ICE; Idarubicin, Cytarabine, and Etopiside). Five days post chemotherapy, she developed febrile neutropenia. Despite broad spectrum intravenous antibiotics and antifungal therapy, the patient died at day nine post chemotherapy. This case demonstrates a previously unreported structural abnormality of chromosome 16 in a patient with AML M4, which represents a third mechanism to inv(16)(p13q22) and t(16;16)(p13q22) in producing the CBF beta-MYH11 fusion. CBF beta-MYH11 fusions masked by cryptic translocations at the cytogenetic level have been detected by FISH and PCR techniques. Due to the improved prognosis associated with CBF beta-MYH11 fusions compared to the standard risk group for AML, its detection remains important.

Adult↗