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Biomedical subjects

K Dietrich

Publications and source records attributed to K Dietrich.

At least 19 recordsLinked to original sources
PubMed2003

Efficacy and tolerability of pantoprazole compared with misoprostol for the prevention of NSAID-related gastrointestinal lesions and symptoms in rheumatic patients.

AIM: To compare the efficacy and tolerability of pantoprazole 20 mg once daily (o.d.) with misoprostol 200 microg twice daily (b.i.d.), administered for 6 months to rheumatic patients who required long-term therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) and who were at increased risk of developing gastrointestinal lesions. METHODS: This randomized, double-blind, multicenter, parallel group comparison study was performed with rheumatic patients (n = 515) who were likely to take NSAIDs continuously for at least 6 months. Patients were 55 years or older, at risk to develop gastrointestinal lesions, had less than five erosions/petechiae in the stomach and duodenum, no ulcers, no reflux esophagitis (endoscopy-proven), and gastrointestinal symptoms of at most moderate intensity. A minimum daily dose was defined for NSAIDs (COX-2 inhibitors were not available at the time). Patients were randomized to take either pantoprazole 20 mg o.d. (n = 257) or misoprostol 200 microg b.i.d. (n = 258) for 6 months while continuing NSAID therapy. Endoscopy was performed at baseline, 3, and 6 months. RESULTS: Pantoprazole was superior to misoprostol (p < 0.001) with regard to 'therapeutic failure' (occurrence of a peptic ulcer, ten or more erosions/petechiae in the stomach/duodenum, reflux esophagitis, severe gastrointestinal symptoms, and/or 'likely' or 'definitely' related adverse event leading to study termination). Estimated remission rates at 3 and 6 months (Kaplan-Meier life-table analysis) were, respectively, 93 and 89% (pantoprazole) and 79 and 70% (misoprostol). Pantoprazole was superior to misoprostol (p = 0.005) with regard to 'endoscopic failure' (occurrence of a peptic ulcer, ten or more erosions/petechiae in the stomach/duodenum, or reflux esophagitis) after 6 months. Estimated remission rates at 3 and 6 months were, respectively, 98 and 95% (pantoprazole) and 95 and 86% (misoprostol). Patients discontinuing the study early due to adverse events 'likely' or 'definitely' related to the study drug accounted for 13/257 (5%) in the pantoprazole and 33/258 (13%) in the misoprostol treatment groups. CONCLUSION: Pantoprazole 20 mg o.d. is superior to misoprostol 200 microg b.i.d. in the prevention of NSAID-induced gastrointestinal lesions and symptoms in patients on continuous long-term treatment with NSAIDs due to rheumatic diseases and at risk to develop such lesions or symptoms.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2003

The effect of Fränkel's function regulator type III on the apical base.

Dento-alveolar and skeletal effects of orthopaedic treatment have always been the subject of controversial scientific discussions. The objective of this retrospective study was to demonstrate the changes in the dental arch and the apical base of both jaws following therapy with Fränkel's function regulator type III (FR III). For this purpose, 42 Class III patients (28 females, 14 males, mean age 7.5 years) were selected according to strict criteria. The control group consisted of 16 patients (eight females, eight males, mean age 8.3 years) with minor malocclusion symptoms. Study models of all patients at the beginning and end of treatment were evaluated using a sophisticated measuring system. Apart from common parameters of model analysis, cusp inclination of the first molars, and apical bases of the maxilla and mandible were recorded to facilitate a comprehensive evaluation of treatment effects (including growth). The FR III stimulated the development of the maxilla, thus resulting in a more physiological growth pattern. Mandibular prognathism, however, was still discernible after therapy in the Class III patients, even though mandibular growth did not differ significantly between the two groups.

Case-Control Studies↗
PubMed2002

A novel mutation of the RP1 gene (Lys778ter) associated with autosomal dominant retinitis pigmentosa.

BACKGROUND: Besides the three known genes (RHO, RDS/Peripherin, NRL) involved in autosomal dominant retinitis pigmentosa (adRP), a fourth gene, RP1, has been recently identified. Initial reports suggest that mutations in the RP1 gene are the second most frequent cause of adRP. The clinical findings were described in a family with adRP and a novel mutation in the RP1 gene. METHOD: Index patients from 15 independent families with adRP in which RHO mutations had been excluded in previous examinations were screened for mutations in the RP1 gene by means of direct DNA sequencing. Evaluation of the RP1 phenotype in patients included funduscopy, kinetic perimetry, dark adapted final threshold test, standard electroretinography and, in one case, multifocal electroretinography. RESULTS: One novel nonsense mutation (Lys778ter) in one of these 15 patients was detected. Cosegregation of the mutation with the disease phenotype could be established in the index patient's family. The phenotype comprises variable expression of clinical disease probably including one case of incomplete penetrance, a onset of symptoms beginning in adulthood, and evidence of regionally varying retinal function loss. CONCLUSION: The Lys778ter mutation localises inside the critical region harbouring all mutations described so far. The ophthalmic findings support previous observations that variation of disease expression appears as a typical feature of the RP1 phenotype.

Aged↗
PubMed2001

Identity and expression pattern of chemosensory proteins in Heliothis virescens (Lepidoptera, Noctuidae).

Analyzing the chemosensory organs of the moth Heliothis virescens, three proteins belonging to the family of insect chemosensory proteins (CSPs) have been cloned; they are called HvirCSP1, HvirCSP2 and HvirCSP3. The HvirCSPs show about 50% identity between each other and 30-76% identity to CSPs from other species. Overall, they are rather hydrophilic proteins but include a conserved hydrophobic motif. Tissue distribution and temporal expression pattern during the last pupal stages were assessed by Northern blots. HvirCSP mRNAs were detected in various parts of the adult body with a particular high expression level in legs. The expression of HvirCSP1 in legs started early during adult development, in parallel with the appearance of the cuticle. HvirCSP1 mRNA was detectable five days before eclosion (day E-5), increased dramatically on day E-3 and remained at high level into adult life. The tissue distribution and the time course of appearance of HvirCSPs are in agreement with a possible role in contact chemosensation.

Amino Acid Sequence↗
PubMed2000

Molecular classification of cutaneous malignant melanoma by gene expression profiling.

The most common human cancers are malignant neoplasms of the skin. Incidence of cutaneous melanoma is rising especially steeply, with minimal progress in non-surgical treatment of advanced disease. Despite significant effort to identify independent predictors of melanoma outcome, no accepted histopathological, molecular or immunohistochemical marker defines subsets of this neoplasm. Accordingly, though melanoma is thought to present with different 'taxonomic' forms, these are considered part of a continuous spectrum rather than discrete entities. Here we report the discovery of a subset of melanomas identified by mathematical analysis of gene expression in a series of samples. Remarkably, many genes underlying the classification of this subset are differentially regulated in invasive melanomas that form primitive tubular networks in vitro, a feature of some highly aggressive metastatic melanomas. Global transcript analysis can identify unrecognized subtypes of cutaneous melanoma and predict experimentally verifiable phenotypic characteristics that may be of importance to disease progression.

Adult↗
PubMed2000

Purification and molecular cloning of chemosensory proteins from Bombyx mori.

Soluble low molecular weight acidic proteins are suspected to transport stimulus molecules to the sensory neurons within insect sensilla. From the antennae of Bombyx mori, we have purified and sequenced a protein (BmorCSP1) bearing sequence similarity to a class of soluble chemosensory proteins recently discovered in several orders of insects. Based on its N-terminal sequence, the cDNA encoding this protein has been amplified and cloned. Differential screening of a B. mori antennal cDNA library led to the identification of a second gene encoding a related protein (BmorCSP2), sharing 35-40% identity to BmorCSP1 and chemosensory proteins from other species. The predicted secondary structures of moth's, chemosensory proteins comprise alpha-helical foldings at conserved positions and a reduced hydrophobicity with respect to this novel family of chemosensory proteins.

Amino Acid Sequence↗
PubMed2000

Chemosensory proteins of Locusta migratoria (Orthoptera: Acrididae).

We describe a family of proteins abundantly expressed in the chemoreception sensory organs, the antennae and legs, of the desert locust, Locusta migratoria (Orthoptera, Acrididae). Using polymerase chain reaction-based approaches and homology screenings, "OS-D"-like proteins were identified in L. migratoria. The different sub-types (LmigOS-Ds) are very similar to each other and share about 50-70% identity with OS-Ds from Drosophila melanogaster and Periplaneta americana. A similar degree of identity was also observed with moth OS-Ds. Northern blot analysis revealed a strong expression of the LmigOS-Ds in the antennae and legs, suggesting their involvement in chemosensory processes. Despite the lack of direct evidence for their role in chemosensation, LmigOS-Ds and their homologs seem to constitute a large protein family, characterized by a striking abundance and diversity among insect chemosensory organs.

Amino Acid Sequence↗
PubMed2000

Chromosomal rearrangements affecting biofilm production and antibiotic resistance in a Staphylococcus epidermidis strain causing shunt-associated ventriculitis.

During two clinical courses of shunt-associated meningitis in a 3-month-old child, five multiresistant S. epidermidis isolates were obtained and analyzed with regard to biofilm production and antibiotic susceptibility. Three S. epidermidis strains, which were initially isolated from the cerebrospinal fluid, produced biofilms on polystyrene tissue culture plates. Following antibiotic treatment and subsequent exchange of the shunt system, sterilization of the CSF was achieved. However, after three weeks a relapse of the infection occurred. The two S. epidermidis isolates obtained now were biofilm negative, but showed an identical resistance pattern as those from the previous infection, except that resistance to rifampicin and increased mininal inhibitory concentrations of aminoglycoside antibiotics had emerged. DNA fingerprinting by PFGE indicated the clonal origin of all isolates. However, some DNA rearrangements and differences in the IS256-specific hybridization patterns could be identified in the isolates from the second infection period that led to altered biofilm formation and increased expression of aminoglycoside resistance traits. The data evidence that variation of biofilm expression occurs in vivo during an infection and highlight the extraordinary genome flexibility of pathogenic S. epidermidis.

Anti-Bacterial Agents↗
PubMed2000

A novel type of carbohydrate-protein linkage region in the tyrosine-bound S-layer glycan of Thermoanaerobacterium thermosaccharolyticum D120-70.

The surface-layer (S-layer) protein of Thermoanaerobacterium thermosaccharolyticum D120-70 contains glycosidically linked glycan chains with the repeating unit structure -->4)[alpha-D-Galp-(1-->2)]-alpha-L-Rhap-(1-->3)[beta-D-Glcp-(1--> 6)] -beta-D-Manp-(1-->4)-alpha-L-Rhap-(1-->3)-alpha-D-Glcp-(1--> . After proteolytic degradation of the S-layer glycoprotein, three glycopeptide pools were isolated, which were analyzed for their carbohydrate and amino-acid compositions. In all three pools, tyrosine was identified as the amino-acid constituent, and the carbohydrate compositions corresponded to the above structure. Native polysaccharide PAGE showed the specific heterogeneity of each pool. For examination of the carbohydrate-protein linkage region, the S-layer glycan chain was partially hydrolyzed with trifluoroacetic acid. 1D and 2D NMR spectroscopy, including a novel diffusion-edited difference experiment, showed the O-glycosidic linkage region beta-D-glucopyranose-->O-tyrosine. No evidence was found of additional sugars originating from a putative core region between the glycan repeating units and the S-layer polypeptide. For the determination of chain-length variability in the S-layer glycan, the different glycopeptide pools were investigated by matrix-assisted laser desorption ionization-time of flight mass spectrometry, revealing that the degree of polymerization of the S-layer glycan repeats varied between three and 10. All masses were assigned to multiples of the repeating units plus the peptide portion. This result implies that no core structure is present and thus supports the data from the NMR spectroscopy analyses. This is the first observation of a bacterial S-layer glycan without a core region connecting the carbohydrate moiety with the polypeptide portion.

Bacterial Proteins↗
PubMed1997

Diagnostic value of 3D CT surface reconstruction in spinal fractures.

Our purpose was to evaluate the diagnostic value of three-dimensional (3 D) CT surface reconstruction in spinal fractures in comparison with axial and reformatted images. A total of 50 patients with different CT-proven spinal fractures were analysed retrospectively. Based on axial scans and reformatted images, the spinal fractures were classified according to several classifications as Magerl for the thoraco-lumbar and lower cervical spine by one radiologist. Another radiologist performed 3 D CT surface reconstructions with the aim of characterizing the different types of spinal fractures. A third radiologist classified the 3 D CT surface reconstruction according to the Magerl classification. The results of the blinded reading process were compared. It was checked to see in which type and subgroup 3 D surface reconstructions were helpful. Readers one and two obtained the same results in the classification. The 3 D surface reconstruction did not yield any additional diagnostic information concerning type A and B injuries. Indeed, the full extent of the fracture could be easier recognized with axial and reformatted images in all cases. In 10 cases of C injuries, the dislocation of parts of vertebrae could be better recognized with the help of 3 D reconstructions. A 3 D CT surface reconstruction is only useful in rotational and shear vertebral injuries (Magerl type C injury).

Humans↗
PubMed1997

Identification of two corticotropin-releasing factor receptors from Xenopus laevis with high ligand selectivity: unusual pharmacology of the type 1 receptor.

Two cDNA clones encoding distinct members of the corticotropin-releasing factor (CRF) receptor family have been isolated from Xenopus laevis with PCR-based approaches. The first full-length cDNA amplified from Xenopus brain encoded a 415-amino acid protein with approximately 80% identity to mammalian CRF receptor type 1 (CRF-R1). The second full-length cDNA isolated from Xenopus brain and heart encoded a 413-amino acid protein with approximately 81% identity to the alpha-variant of mammalian CRF receptor, type 2 (CRF-R2). No evidence could be obtained that the beta-variant of CRF-R2 existed in Xenopus laevis. Binding studies using human embryonic kidney 293 (HEK 293) cells stably transfected with xenopus CRF-R2 showed that the CRF analogues urotensin I, urocortin, and sauvagine were bound with higher affinities than human/rat CRF, xenopus CRF, and ovine CRF. In contrast to human CRF-R1, xenopus CRF-R1 (xCRF-R1) was very selective for different CRF ligands. Urotensin I, urocortin, human/rat CRF, and xenopus CRF were bound with significantly (10-22-fold) higher affinities than ovine CRF (K(D) = 31.7 nM) and sauvagine (K(D) = 51.4 nM). In agreement with these binding data, EC50 values of 39.7 and 1.1 nM were found for sauvagine and for human/rat CRF or xenopus CRF, respectively, when the cyclic AMP production in HEK 293 cells stably transfected with xCRF-R1 was determined.

Amino Acid Sequence↗
PubMed1996

Faulty DNA polymerase delta/epsilon-mediated excision repair in response to gamma radiation or ultraviolet light in p53-deficient fibroblast strains from affected members of a cancer-prone family with Li-Fraumeni syndrome.

Dermal fibroblast strains cultured from affected members of a cancer-prone family with Li-Fraumeni syndrome (LFS) harbor a point mutation in one allele of the p53 tumor suppressor gene, resulting in loss of normal p53 function. In this study we have examined the ability of these p53-deficient strains to carry out the long-patch mode of excision repair, mediated by DNA polymerases delta and epsilon, after exposure to 60Co gamma radiation or far ultraviolet (UV) (chiefly 254 nm) light. Repair was monitored by incubation of the irradiated cultures in the presence of aphidicolin (apc) or 1-beta-D-arabinofuranosylcytosine (araC), each a specific inhibitor of long-patch repair, followed by measurement of drug-induced DNA strand breaks (reflecting non-ligated strand incision events) by alkaline sucrose velocity sedimentation. The LFS strains displayed deficient repair capacity in response to both gamma rays and UV light. The repair anomaly in UV-irradiated LFS cultures was manifested not only in the overall genome, but also in the transcriptionally active, preferentially repaired c-myc gene. Using autoradiography we also assessed unscheduled DNA synthesis (UDS) after UV irradiation and found this conventional measure of repair replication to be deficient in LFS strains. Moreover, both apc and araC decreased the level of UV-induced UDS by approximately 75% in normal cells, but each had only a marginal effect on LFS cells. We further demonstrated that the LFS strains are impaired in the recovery of both RNA and replicative DNA syntheses after UV treatment, two molecular anomalies of the DNA repair deficiency disorders xeroderma pigmentosum and Cockayne's syndrome. Together these results imply a critical role for wild-type p53 protein in DNA polymerase delta/epsilon-mediated excision repair, both the mechanism operating on the entire genome and that acting on expressed genes.

Cytarabine↗
PubMed1995

Effect of early lead exposure on children's postural balance.

This study investigated the effect of chronic exposure to lead on children's ability to maintain upright postural balance as a biological marker of lead-induced modifications of the neuromotor system. For this study, 162 six-year-old children, with a five-year geometric mean lead concentration in blood of 11.9 micrograms/dL (range 4.0-28.0 micrograms/dL), were tested for postural balance with a microprocessor-based force platform system. An increase in blood lead was significantly associated with an increase in the variable postural sway--implying poorer postural balance. This association was not influenced by socio-economic, racial or environmental factors. This simple, objective and quick technique may be useful for assessing gross motor functions in children who are at or below the United States Centers for Disease Control's class III category and/or for monitoring the effectiveness of medical interventions aimed at reversing lead-associated impairment of upright postural balance.

Child↗
PubMed1993

Aphidicolin and 1-beta-D-arabinofuranosylcytosine strongly inhibit transcriptionally active DNA repair in normal human fibroblasts.

Both aphidicolin and 1-beta-D-arabinofuranosylcytosine (araC) inactivate DNA polymerases alpha, delta and epsilon, and according block long-patch excision repair in mammalian cells. We report here that in normal human fibroblasts both compounds strongly inhibit the repair of damage induced by UV or 4-nitroquinoline-1-oxide in the transcriptionally active c-myc gene, as indicated by the appearance of DNA strand breaks in carcinogen-treated cultures that were subsequently incubated in the presence of either polymerase inhibitor. We further demonstrate that the repair of UV photoproducts in the c-myc gene can be monitored by photolysis (313 nm) of DNA repaired in the presence of bromodeoxyuridine (BrdUrd). In UV-irradiated cultures, the incidence of aphidicolin- or araC-accumulated strand breaks was approximately 70% of that detected by the BrdUrd photolysis assay. Our data therefore implicate a critical role for DNA polymerases alpha, delta and/or epsilon in gene-specific repair in human cells. The techniques described here may prove useful in the study of DNA repair in defined sequences of the human genome following exposure to a diverse array of physical and chemical genotoxic agents.

4-Nitroquinoline-1-oxide↗