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Biomedical subjects

S Richter

Publications and source records attributed to S Richter.

At least 91 records · Page 5Linked to original sources
PubMed1999

[Continuous spinal anesthesia in very elderly patients with high anesthesia risk in traumatologic-orthopedic and general surgery interventions].

Continuous spinal anaesthesia (CSA) was carried out via a 28-gauge spinal catheter in 154 surgical patients at the Department of Anaesthesiology and Critical Care at Radeberg Asklepios-ASB Hospital between May 1992 and March 1999. The method was used preferably in patients aged over 70 (mean age 82.3 years) with high general risk during anaesthesia (ASA III-IV) who underwent orthopaedic or general surgery of the lower limb and hypogastrium. Remarkably, an anaesthetic level of between Th 8 and Th 10 was achieved with the low initial dose of 7.5 mg of 0.5% hyperbaric bupivacaine. Only minimal cardiovascular and respiratory side-effects were observed in comparison to single shot spinal and general anaesthesia. In the whole series, no anaesthesia-related complications were seen. Another benefit of CSA is the option of applying a second dose with longer duration of surgery to keep the optimal anaesthetic level. In addition, the method is suitable for postoperative analgesia over a period of 2 to 3 days.

Aged↗
PubMed1999

[Measuring residual urine by portable ultrasound scanner].

Urethral catheterization, the standard method of measuring residual urine, is uncomfortable and associated with risk of infection and trauma to the urethra. It has also been reported as inaccurate to a certain extent. We compared catheterization with ultrasound scanning in a prospective study of 52 men and 3 women. 100 measurements of postvoiding residual urine by portable ultrasound scanner, were each followed immediately by urethral catheterization (both procedures performed by an experienced nurse in our outpatient clinic). A difference of > 25 ml between measurements by scanner and by catheter was considered significant. The range of residual urine measured by scanner was 1-425 ml, and by catheter 1-410 ml. There was good matching between the 2 methods in 85 of 100 measurements (scanning accuracy 85%). In 30/85 matching was excellent while in 55 cases the mean difference was 8.5 +/- 6.2 ml, range 1-24 ml. The accuracy of scanning was 85%; there was perfect matching between the 2 methods in 30 cases. In the remaining 15 cases the mean difference was 41.8 +/- 13.6 ml (range 25-56). Each catheterization took 4-5 minutes and scanning 30 seconds. There were no complications after catheterization, but all reported discomfort and dysuria for 1-2 hours thereafter. Scanning was absolutely uneventful in all. The cost per catheterization, including medication, disposable materials and personnel time was approximately 80 NIS. Our 80-90 measurements of residual urine a month require annually about 80 hours and a budget of about NIS 80,000. Scanning requires only 8 hours, while the cost of the portable scanner is significantly less than NIS 80,000 and it can be used for more than a year. We conclude that measuring urine residual with the noninvasive scanner instead of by catheterization is easier, more accurate, and more cost-effective.

Adult↗
PubMed1999

Long-term incidence of acute myocardial infarction after open and transurethral resection of the prostate for benign prostatic hyperplasia.

PURPOSE: Acute myocardial infarction was found to be the main cause of increased long-term mortality in patients after transurethral compared to open prostatectomy in various retrospective studies. We performed a randomized prospective study to compare morbidity and incidence of acute myocardial infarction in patients after transurethral compared to open prostatectomy for benign prostatic hyperplasia. MATERIALS AND METHODS: We studied 365 patients who were assigned to transurethral (236) or open (129) prostatectomy only according to the size of the prostate and who were followed for 7 to 8 years. The clinical status of the patients in both groups before and after the operation was compared, and the rate of myocardial infarction and long-term mortality was studied. RESULTS: More patients with a history of cerebrovascular accident (5.4 versus 0.8%) and indwelling catheters (16.3 versus 7.6%) before the operation were in the open prostatectomy group. Among the 236 patients operated on transurethrally 31 were reoperated on (6 more than once) during followup compared to 4 of the 129 patients who underwent open prostatectomy. In 15 patients from the transurethral prostatectomy group myocardial infarction developed compared to 9 patients in the open prostatectomy group. This difference was not statistically significant. The rate of acute myocardial infarction after prostatectomy, no matter which approach was used, was greater than 6% and it appeared to be higher when compared to the rate of infarction in the general population of the same age group, which is approximately 2.5% in our county. There was no statistically significant difference in the overall mortality rate between the transurethral and open prostatectomy groups, which was 14.4 and 8.5% respectively. CONCLUSIONS: Open prostatectomy is more effective in overcoming urinary obstruction than the transurethral approach. No significant differences in myocardial infarction or overall mortality rates were found between the 2 groups.

Aged↗
PubMed1998

A chloroplast processing enzyme functions as the general stromal processing peptidase.

A highly specific stromal processing activity is thought to cleave a large diversity of precursors targeted to the chloroplast, removing an N-terminal transit peptide. The identity of this key component of the import machinery has not been unequivocally established. We have previously characterized a chloroplast processing enzyme (CPE) that cleaves the precursor of the light-harvesting chlorophyll a/b binding protein of photosystem II (LHCPII). Here we report the overexpression of active CPE in Escherichia coli. Examination of the recombinant enzyme in vitro revealed that it cleaves not only preLHCPII, but also the precursors for an array of proteins essential for different reactions and destined for different compartments of the organelle. CPE also processes its own precursor in trans. Neither the recombinant CPE nor the native CPE of chloroplasts process a preLHCPII mutant with an altered cleavage site demonstrating that both forms of the enzyme are sensitive to the same structural modification of the substrate. The transit peptide of the precursor of ferredoxin is released by a single cleavage event and found intact after processing by recombinant CPE and a chloroplast extract as well. These results provide the first direct demonstration that CPE is the general stromal processing peptidase that acts as an endopeptidase. Significantly, recombinant CPE cleaves in the absence of other chloroplast proteins, and this activity depends on metal cations, such as zinc.

Amino Acid Sequence↗
PubMed1998

Recombinant expression and biochemical characterization of an NADPH:flavin oxidoreductase from Entamoeba histolytica.

The gene encoding a putative NADPH:flavin oxidoreductase of the protozoan parasite Entamoeba histolytica (Eh34) was recombinantly expressed in Escherichia coli. The purified recombinant protein (recEh34) has a molecular mass of about 35 kDa upon SDS/PAGE analysis, exhibits a flavoprotein-like absorption spectrum and contains 1 mol of non-covalently bound FMN per mol of protein. RecEh34 reveals two different enzymic activities. It catalyses the NADPH-dependent reduction of oxygen to hydrogen peroxide (H2O2), as well as of disulphides such as 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) and cystine. The disulphide reductase but not the H2O2-forming NADPH oxidase activity is inhibitable by sulphydryl-active compounds, indicating that a thiol component is part of the active site for the disulphide reductase activity, whereas for the H2O2-forming NADPH oxidase activity only the flavin is required. Compared with the recombinant protein, similar activities are present in amoebic extracts. Native Eh34 is active in a monomeric as well as in a dimeric state. In contrast to recEh34, no flavin was associated with the native protein. However, both NADPH oxidase as well as DTNB reductase activity were found to be dependent on the addition of FAD or FMN.

Animals↗
PubMed1998

Normalization of fasting glycaemia by intravenous GLP-1 ([7-36 amide] or [7-37]) in type 2 diabetic patients.

Intravenous GLP-1 [7-36 amide] can normalize fasting hyperglycaemia in Type 2 diabetic patients. Whether GLP-1 [7-37] has similar effects and how quickly plasma glucose concentrations revert to hyperglycaemia after stopping GLP-1 is not known. Therefore, 8 patients with Type 2 diabetes (5 female, 3 male; 65+/-6 years; BMI 34.3+/-7.9 kg m(-2); HbA1c 9.6+/-1.2%; treatment with diet alone (n=2), sulphonylurea (n=5), metformin (n=1)) were examined twice in randomized order. GLP-1 [7-36 amide] or [7-37] (1 pmol kg(-1)min(-1) were infused intravenously over 4 h in fasted subjects. Plasma glucose (glucose-oxidase), insulin and C-peptide (ELISA) was measured during infusion and for 4 h thereafter. Indirect calorimetry was performed. Fasting hyperglycaemia was 11.7+/-0.9 [7-36 amide] and 11.3+/-0.9 mmol l(-1) [7-37]. GLP-1 infusions stimulated insulin secretion approximately 3-fold (insulin peak 168+/-32 and 156+/-47 pmol l(-1), p<0.0001 vs basal; C-peptide peak 2.32+/-0.28 and 2.34+/-0.43 nmol l(-1), p<0.0001, respectively, with GLP-1 [7-36 amide] and [7-37]). Four hours of GLP-1 infusion reduced plasma glucose (4.8+/-0.4 and 4.6+/-0.3 mmol l(-1), p<0.0001 vs basal values), and it remained in the non-diabetic fasting range after a further 4 h (5.1+/-0.4 and 5.3+/-0.4 mmol l(-1), for GLP [7-36 amide] and [7-37], respectively). There were no significant differences between GLP-1 [7-36 amide] and [7-37] (glucose, p=0.99; insulin, p=0.99; C-peptide, p=0.99). Neither glucose oxidation nor lipid oxidation (or any other parameters determined by indirect calorimetry) changed during or after the administration of exogenous GLP-1. In conclusion, GLP-1 [7-36 amide] and [7-37] normalize fasting hyperglycaemia in Type 2 diabetic patients. Diabetes therapy (diet, sulphonyl ureas or metformin) does not appear to influence this effect. In fasting and resting patients, the effect persists during administration of GLP-1 and for at least 4 h thereafter, without rebound. Significant changes in circulating substrate concentrations (e.g. glucose) are not accompanied by changes in intracellular substrate metabolism.

Age of Onset↗
PubMed1998

[Detection of monoclonal T-cells with TCR gamma PCR in mycosis fungoides].

The monoclonal dominant malignant T cells in mycosis fungoides (MF) carry identical TCR gamma rearrangements. Their detection is a useful diagnostic tool. Thus, in routine diagnosis we investigated the occurrence of monoclonal T cells in skin biopsy samples of MF-patients by TCR gamma-PCR, followed by temperature gradient gel electrophoresis (TGGE). In 188 out of 208 MF patients, at least one skin sample with sufficient DNA quality for PCR analysis was obtained. Applying a consensus PCR for the TCR gamma genes V gamma I and J gamma 1/2, we detected monoclonal T cells in 122 cases (65%). In the remaining 66 cases, we performed two multiplex-PCRs, covering rearrangements of the other TCR gamma genes. Here we found in 11 cases (6%) predominant clonal rearrangements of V gamma II-IV and J gamma 1/2 and in 2 (1%) those of V gamma I-IV and J gamma P 1/2. In patients with MF, detecting rearrangements of only V gamma I and J gamma 1/2 is sufficient for PCR screening analysis. In 53 of the patients (28%) the applied methods revealed no monoclonal T cells. This may be due to a low cell number, oligoclonal nature, chromosomal abberations or remaining of TCR in germline configuration.

Gene Rearrangement, gamma-Chain T-Cell Antigen Rec↗
PubMed1998

[Recurrent panuveitis. First manifestation of Behçet disease in childhood].

BACKGROUND: Behçet's disease is a rare systemic vasculitis of unknown etiology. The typical symptoms include recurrent oral and/or genital aphthous lesions, iridocyclitis (historically with hypopyon) and various skin lessions. The number of young adults and children which are diagnosed with Behçet-syndrome is increasing in recent years and the mean age of manifestation has decreased to 25 years in German patients. The disease is generally diagnosed later in German (48.5 months) than in Turkish patients (25.5 months). Ocular manifestation has been confirmed as a marker of severe prognosis. In 15-25% of affected patients it leads to blindness. PATIENT: We describe a 19-year-old Caucasian woman who has suffered from the typical symptoms (oral aphthous lesions, recurrent uveitis posterior, various skin lesions) since the 16th year of age. RESULTS: After three years the patient was finally be diagnosed with Behçet's disease (using the criteria of the "International Study Group for Behçet's Disease"). Visual acuity was stabilized with an immunosuppressive therapy, although there was no complete remission in disease activity. In addition a cerebral vasculitis was manifested. CONCLUSIONS: Ophthalmologists should be familiar with Behçet's disease. In cases of recurrent uveitis Behçet's disease should be included in the differential diagnosis because timely immunosuppressive therapy can prevent irrevocable changes in the corpus vitreum and retina and preserve complete visual acuity.

Adolescent↗
PubMed1998

The wingless gene is required for embryonic brain development in Drosophila.

We have studied the role of the wingless gene in embryonic brain development of Drosophila. wingless is expressed in a large domain in the anlage of the protocerebrum and also transiently in smaller domains in the anlagen of the deutocerebrum and tritocerebrum. Elimination of the wingless gene in null mutants has dramatic effects on the developing protocerebrum; although initially generated, approximately one half of the protocerebrum is deleted in wingless null mutants by apoptotic cell death at late embryonic stages. Using temperature sensitive mutants, a rescue of the mutant phenotype can be achieved by stage-specific expression of functional wingless protein during embryonic stages 9-10. This time period correlates with that of neuroblast specification but preceeds the generation and subsequent loss of protocerebral neurons. Ectopic wingless over-expression in gain-of-function mutants results in dramatically oversized CNS. We conclude that wingless is required for the development of the anterior protocerebral brain region in Drosophila. We propose that an important role of wingless in this part of the developing brain is the determination of neural cell fate.

Animals↗
PubMed1998

Unique organization of the dnaA region from Prochlorococcus marinus CCMP1375, a marine cyanobacterium.

In order to study DNA replication control elements in cyanobacteria we cloned and sequenced the dnaA gene from the marine cyanobacterium Prochlorococcus marinus. The dnaA gene is ubiquitous among bacteria and encodes the DNA replication initiation factor DnaA. The deduced amino acid sequence of the P. marinus DnaA protein shows highest similarity to the DnaA protein from the freshwater cyanobacterium Synechocystis sp. PCC6803. Using a solid-phase DNA binding assay we demonstrated that both cyanobacterial DnaA proteins specifically recognize chromosomal origins, oriC, of Escherichia coli and Bacillus subtilis in vitro. The genetic environment of dnaA is not conserved between the two cyanobacteria. Upstream of the P. marinus dnaA gene we identified a gene encoding a putative ATP-binding cassette (ABC) transport protein. The gor gene encoding glutathione reductase lies downstream of dnaA. Comparison of the genetic structure of dnaA regions from 15 representative bacteria shows that the pattern of genes flanking dnaA is not universally conserved among them.

Amino Acid Sequence↗
PubMed1998

Does the narrow operating field in perineal radical prostatectomy lead to more positive surgical margins?

AIMS: To assess the risk of leaving cancer-positive surgical margins in the perineal approach for radical prostatectomy as compared to the retropubic approach. METHODS: Seventy-six patients with clinically organ-confined prostate cancer (stage T1-2 NoMo) underwent radical prostatectomy. The 57 patients who underwent retropubic prostatectomy were compared to 19 patients in whom the perineal approach was undertaken. The two groups were compared for pre-operative PSA levels, clinical stage, biopsy Gleasson score, and any correlation between pre- and post-operative stage and grade of the disease and rate of cancer-positive surgical margins. RESULTS: Although there were no significant differences in the rate of organ-confined diseases and specimen Gleasson score in the two groups, the rate of positive surgical margins in the perineal approach was significantly lower (15.7 vs 29.8%) and the rate of extracapsular disease with negative margins was significantly higher (15.7 vs 7%). CONCLUSIONS: The narrow surgical field in the perineal approach for radical prostatectomy does not pose a higher risk for positive surgical margins and it might be the procedure of choice in stage T1C prostate cancer with a Gleasson score of below 7.

Aged↗
PubMed1998

The cyanobacterium Synechocystis sp. strain PCC 6803 expresses a DNA methyltransferase specific for the recognition sequence of the restriction endonuclease PvuI.

By use of restriction endonucleases, the DNA of the cyanobacterium Synechocystis sp. strain PCC 6803 was analyzed for DNA-specific methylation. Three different recognition sites of methyltransferases, a dam-like site including N6-methyladenosine and two other sites with methylcytosine, were identified, whereas no activities of restriction endonucleases could be detected in this strain. slr0214, a Synechocystis gene encoding a putative methyltransferase that shows significant similarities to C5-methylcytosine-synthesizing enzymes, was amplified by PCR and cloned for further characterization. Mutations in slr0214 were generated by the insertion of an aphII gene cassette. Analyses of chromosomal DNAs of such mutants demonstrated that the methylation pattern was changed. The recognition sequence of the methyltransferase was identified as 5'-CGATCG-3', corresponding to the recognition sequence of PvuI. The specific methyltransferase activity was significantly reduced in protein extracts obtained from mutant cells. Mutation of slr0214 also led to changed growth characteristics of the cells compared to wild-type cells. These alterations led to the conclusion that the methyltransferase Slr0214 might play a regulatory role in Synechocystis. The Slr0214 protein was also overexpressed in Escherichia coli, and the purified protein demonstrated methyltransferase activity and specificity for PvuI recognition sequences in vitro. We propose the designation M.Ssp6803I [corrected] (Synechocystis methyltransferase I) for the slr0214-encoded enzyme.

Amino Acid Sequence↗
PubMed1998

Transcriptional analysis and mutation of a dnaA-like gene in Synechocystis sp. strain PCC 6803.

Transcription of the dnaA gene of the cyanobacterium Synechocystis sp. strain PCC 6803 is light dependent and yields a monocistronic mRNA, as determined by Northern analysis. Surprisingly, mutants with inactivated dnaA were viable. In batch cultures under standard conditions, the mutants grew like the wild type and did not show an aberrant phenotype. We conclude that, unlike the situation in other bacteria, dnaA of Synechocystis sp. cannot have an essential function, such as initiation of DNA replication.

Bacterial Proteins↗
PubMed1998

One step direct detection of recurrent mutations in the breast cancer susceptibility gene, BRCA1.

Germ-line mutations of the BRCA1 gene have been linked to 85% of hereditary breast and ovarian cancers. More than one hundred mutations have been reported, including several which are over represented within the Ashkenazi Jewish (185delAG) and Irish families (1294del40). These recurrent mutations are cost-effective targets for presymptomatic screening of cancer susceptibility. Most current techniques such as single strand conformation polymorphism, heteroduplex analysis, DNA sequencing, and protein translation termination assays are multistep, time consuming methods and require radioactive isotopes for mutation detection. As an alternative, we have developed a single step, non-radioactive allele specific oligonucleotide (ASO) PCR assay designed to target any known mutation. Its application to detection of the BRCA1 185delAG and 1294del40 mutations is described here. The ASO PCR is efficient, highly sensitive, non-radioactive, specific for individual mutations, performed in a single step, and is amenable to large-scale screening for other known mutations.

Alleles↗
PubMed1998

[Nursing knowledge and attitude of day care personnel towards health promotion of babies].

Currently it is more acceptable that women work. Besides women who are obliged to work to contribute to the income of their families, a large number of women work due to a need for social stimulation. While their mothers are at work during the day, the babies are left in substitute care out of necessity. Health promotion of babies is necessary and is the duty of the substitute caregiver. These women, however, do not always have the knowledge of, or positive attitude towards, health promotion. The purpose of this study, was to determine the knowledge and skills that the day mother should have in order to promote the health of babies (age 0-12 month). The qualititative research approach was used, within which a descriptive study had been done. A comprehensive literature study had initially been done regarding the health promotion of babies in substitute care. A programme had been compiled regarding the knowledge and skills that a day mother must possess in order to promote the health of babies. This program was then submitted to a group of selected experts for evaluation according to the Delphi technique. According to the data, it is quite clear that the day mother should be knowledgeable and skilled in order to satisfy the baby's physiological, security and affiliation needs as well as the need for appreciation and self-actualization.

Attitude of Health Personnel↗
PubMed1997

Removal of hydrogen peroxide by the 29 kDa protein of Entamoeba histolytica.

The 29 kDa protein of Entamoeba histolytica (Eh29), as well as a truncated variant of this protein, which lacks a cysteine-rich N-terminal region of 40 amino acid residues (Eh29mut), were recombinantly expressed in Escherichia coli and purified to homogeneity. Both recombinant proteins (recEh29, recEh29mut) were found to have hydrogen peroxide (H2O2)-removing activity, but recEh29 was twice as active as recEh29mut. For the consumption of exogenous H2O2, activity was dependent on the presence of reducing equivalents, such as dithiothreitol (DTT), indicating that Eh29 constitutes a thiol-dependent peroxidase. DTT was not required to remove H2O2 by recEh29 or recEh29mut when H2O2 was generated enzymically by the E. histolytica NADPH:flavin oxidoreductase. This enzyme produces H2O2 under aerobic conditions and simultaneously serves as a hydrogen donor for Eh29. Peroxidase activity of the recombinant proteins was further supported by complementation of an E. coli strain that lacks the entire alkyl hydroperoxide reductase locus. The high sensitivity of these bacteria against cumene hydroperoxide was significantly reduced by the introduction of the genes encoding recEh29 or recEh29mut. Using antisera raised against the recombinant proteins, native Eh29 was localized within the cytoplasm of the amoebae. In addition, the antisera reacted with proteins of E. histolytica lysates with apparent molecular masses of 35 kDa and 160-300 kDa. All of them exhibited thiol-peroxidase activity.

Animals↗
PubMed1997

[Intracavitary afterloading therapy as a new technique of boost irradiation in anal canal carcinoma].

PURPOSE: There are different techniques of boost irradiation in the treatment of patients with anal carcinoma. A new system of applicators is presented, which can be used for an intracavitary afterloading therapy. MATERIAL AND METHODS: Three different applicators are available, the first with a central catheter (K1), a second with 5 semicircular fixed catheters (K2) and an eccentric shield, a third with 8 circular fixed catheters and a central shield (K3). RESULTS: The adequate choice of applicator and catheters takes into consideration the individual localisation and extension of anal carcinoma in planning therapy. Thus, in circular growing tumors, an irradiation of the whole circumference of the anal canal is possible. In non-circular growing tumors, the dose applied in the non-affected part of the anal canal can be reduced to a quarter of the dose applied at the tumor. CONCLUSION: The new system of intracavitary afterloading therapy is a good alternative to previous techniques of boost irradiation in the treatment of anal carcinoma. By means of this technique, irradiation can be highly individualized, the tumor better included and non-affected sections of the anal canal saved.

Anus Neoplasms↗