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Biomedical subjects

W Schmidt

Publications and source records attributed to W Schmidt.

At least 271 records · Page 15Linked to original sources
PubMed1996

[The German Alzheimer Family Groups. An assessment of current status].

Counselling the relatives of psychiatric patients is becoming increasingly important. This includes the relatives of patients with Alzheimer's disease. Since little is known about the organization and function of support groups for family caregivers of Alzheimer patients, in 1994 we wrote to all such groups known to us and asked them to fill in a questionnaire. The response rate was 85% (84/99), and 66 of the forms could be used for further analysis. The results were as follow: Most groups for relatives of Alzheimer patients admitted new members at any time. 69% had existed for more than 1 year and 19% for more than 5 years. 81% consisted of 6-15 participants. 73% of the groups met once in a month. Health professionals organized the groups in 65% of cases. The main topics were trading information about the disease and support as well as daily care requirements. 73% of the groups were associated with health institutions or nationwide support organizations. Public relations were managed by personal contacts and press reports; did the groups rarely advertise. Based on a review of the literature, the impact of structure upon the function of groups is discussed.

Activities of Daily Living↗
PubMed1996

Determination of aliphatic and alicyclic amines in water by gas and liquid chromatography after derivatization by chloroformates.

Two new methods were developed for the analysis of aliphatic (n-propylamine, pentylamine, hexylamine, heptylamine, octylamine) and alicyclic (pyrrolidine, morpholine, piperidine, piperazine) amines in water samples after derivatization and liquid-liquid-extraction. The carbamate-derivatives formed were determined by GC/MS (trichloroethyl carbamates) as well as by HPLC/fluorescence detection (9-fluorenylmethyl carbamates) in a concentration range between 0.05 and 1.0 microg/l suitable for drinking water analysis. Applications to German rivers and sewage plants show that both new methods produce corresponding results in analysing aliphatic and alicyclic amines in surface waters as well as in waste water samples.

Journal Article↗
PubMed1996

Hemodynamic and hormonal effects of quinaprilat in patients with congestive heart failure.

OBJECTIVE: To assess the pharmacodynamic activity and safety of rising single and multiple doses of intravenous quinaprilat compared with placebo in patients with New York Heart Association (NYHA) class III and IV congestive heart failure who were receiving digitalis or diuretic therapy or both. METHODS: Patients were randomly assigned to three treatment groups to receive low (0.5 to 1.0 mg), medium (1.0 and 2.5 mg), or high (5.0 and 10.0 mg) single intravenous doses of quinaprilat or placebo on day 1. On the basis of responses observed on day 1, the three treatment groups received stable multiple intravenous doses of either quinaprilat or placebo every 6 hours on days 2 and 3. Hemodynamic measurements, hormonal assessments, and safety were evaluated before and at specified intervals during the study. RESULTS: Compared with placebo, single and multiple doses of quinaprilat increased cardiac index and reduced pulmonary capillary wedge pressure, mean arterial pressure, systemic vascular resistance, and right atrial pressure in a dose-related manner. No clinically important change in heart rate was observed. Hemodynamic changes after multiple-dose quinaprilat administration were similar to those observed after single doses and were generally sustained during the 6-hour dosing interval. Relative to placebo, quinaprilat reduced plasma angiotensin converting enzyme (ACE) activity, angiotensin II concentration, and aldosterone concentration and increased plasma renin activity; no prominent changes in plasma catecholamine and atrial natriuretic peptide concentrations were observed. There were no clinically important drug-related changes in the safety parameters. CONCLUSIONS: Single and multiple intravenous doses of 0.5 to 10 mg quinaprilat are well-tolerated and produce favorable dose-dependent hemodynamic effects and hormonal changes consistent with those expected of an ACE inhibitor in patients with NYHA class III and IV congestive heart failure.

Adult↗
PubMed1996

The effect of chromatin condensation (aniline blue staining) and morphology (strict criteria) of human spermatozoa on fertilization, cleavage and pregnancy rates in an intracytoplasmic sperm injection programme.

The main purpose of this study was to determine the possible relationship between chromatin condensation (Aniline Blue staining), the morphology of spermatozoa according to strict criteria, and the fertilization, cleavage and pregnancy rate in an intracytoplasmic sperm injection (ICSI) programme. A total of 60 patients were divided into two groups (27 versus 34) according to sperm stainability by Aniline Blue. The first group involved patients having a positive Aniline Blue staining test with 0-29% stained. The fertilization rate in this group was 60.8%, cleavage rate 54.4% and pregnancy rate 18.5%. In the second group in which > 29% spermatozoa were positively stained, the fertilization rate was 62.1%, cleavage rate 62.0% and pregnancy rate 35.3%. There was no statistically significant difference between the two groups. Furthermore, the influence of morphology according to strict criteria after Papanicolaou staining on successful fertilization, cleavage and pregnancy was studied in 85 patients who were divided into two groups according to the percentage of morphologically normal sperm. The fertilization, cleavage and pregnancy rates were 44.21, 63.37, and 39.47% respectively in the first group (< 4%), the corresponding values for the second group (> 4%) were 56.50, 46.04 and 21.21%. There was no significant correlation between the fertilization (P = 0.722), cleavage (P = 0.519) and pregnancy (P = 0.096) rates in either group. This study demonstrates that neither chromatin condensation (Aniline Blue staining) nor morphology could assess the fertilization potential, cleavage and pregnancy rate in an ICSI programme.

Aniline Compounds↗
PubMed1996

Stool viruses, coinfections, and diarrhea in HIV-infected patients. Berlin Diarrhea/Wasting Syndrome Study Group.

To examine the prevalence of stool viruses and their role in the pathogenesis of diarrhea in HIV infection, we evaluated biopsies and repeated stool samples of 256 HIV-infected patients undergoing diagnostic endoscopy because of diarrhea (n = 136) or other symptoms (n = 120) for bacterial, protozoal, and viral enteropathogens. In 70% of the patients with diarrhea, at least one potential enteropathogen was detected. Stool virus was detected by electron microscopy in 17% (44 of 256), adenovirus in 6.6% (17 of 256), and coronavirus in 11.3% (29 of 256) of the patients. Adenovirus and coronavirus were detected more frequently in patients with diarrhea than in patients without diarrhea [adenovirus 10% (13 of 136) vs. 3.3% (4 of 120), p = 0.0129; coronavirus 15% (21 of 136) vs. 6.6% (8 of 120), p = 0.0142]. Sixty-one percent of patients harboring stool virus were coinfected by another enteropathogen. Pathogens other than stool virus were detected more frequently in patients harboring adenovirus (82%) than in patients without stool virus (48%, p < 0.025). Adenovirus and coronavirus are frequently detected in stools of HIV- infected patients and may contribute to diarrhea. Adenovirus infection may facilitate the occurrence of other intestinal pathogens. Due to frequent coinfections, detection of stool viruses reduces the rate of diarrhea of unknown origin only by approximately 5%.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Glycerol enhancement of ligand-polylysine/DNA transfection.

Primary human fibroblasts and a series of cell lines (A549, BNL CL.2, H225, NIH 3T3 and Rat-1) are efficiently transfected by using positively charged complexes of plasmid DNA and transferrin-polylysine or polylysine in the presence of glycerol (1 molar to 1.8 molar, depending on the cell type). An increase in gene expression of up to several-hundredfold (compared to complexes without glycerol) is obtained if the transfection mixture is incubated with the cells for 3-4 h at 37 degrees C. This simple method has been used for transient expression of luciferase, beta-galactosidase and interleukin-2, and also for the generation of stably transfected cells.

Animals↗
PubMed1996

Quality Determining Parameters of Balloon Angioplasty Catheters.

The investigations carried out on balloon angioplasty catheters using a parameter test unit allow an objective comparison and a qualitative assessment of catheter brands with respect to their stenosis passability. The design of the test unit allows the measure of other parameters important for clinical practice, such as pushability and trackability. Altogether 8 over-the-wire and 10 monorail-catheters from 7 different manufacturers were investigated by our study. Between modern over-the-wire and monorail systems there exists no fundamental difference in passage capability. In some brands of catheter the stenosis model shows no increase in the amount of thrust required, even after repeated inflation; this is accountable to the good folding properties of the balloon. Angioplasty balloons made of less overstretchable or thinner material yielded the best results. The fact that changes in balloon quality may result from pre-inflation should carry weight in discussions concerning the reuse of catheters. The measurement results are useful for the correct selection of a catheter appropriate to the therapy task at hand.

Journal Article↗
PubMed1996

Characterization of the factor VIII defect in 147 patients with sporadic hemophilia A: family studies indicate a mutation type-dependent sex ratio of mutation frequencies.

The clinical manifestation of hemophilia A is caused by a wide range of different mutations. In this study the factor VIII genes of 147 severe hemophilia A patients--all exclusively from sporadic families--were screened for mutations by use of the complete panel of modern DNA techniques. The pathogenous defect could be characterized in 126 patients (85.7 percent). Fifty-five patients (37.4 percent) showed a F8A-gene inversion, 47 (32.0 percent) a point mutation, 14 (9.5 percent) a small deletion, 8 (5.4 percent) a large deletion, and 2 (1.4 percent) a small insertion. Further, four (2.7 percent) mutations were localized but could not be sequenced yet. No mutation could be identified in 17 patients (11.6 percent). Sixteen (10.9 percent) of the identified mutations occurred in the B domain. Four of these were located in an adenosine nucleotide stretch at codon 1192, indicating a mutation hotspot. Somatic mosaicisms were detected in 3 (3.9 percent) of 76 patients, mothers, comprising 3 of 16 de novo mutations in the patients mothers. Investigation of family relatives allowed detection of a de novo mutation in 16 of 76 two-generation and 28 of 34 three-generation families. On the basis of these data, the male:female ratio of mutation frequencies (k) was estimated as k = 3.6. By use of the quotients of mutation origin in maternal grandfather to patients mother or to maternal grandmother, k was directly estimated as k = 15 and k = 7.5, respectively. Considering each mutation type separately, we revealed a mutation type-specific sex ratio of mutation frequencies. Point mutations showed a 5-to-10-fold-higher and inversions a >10-fold-higher mutation rate in male germ cells, whereas deletions showed a >5-fold-higher mutation rate in female germ cells. Consequently, and in accordance with the data of other diseases like Duchenne muscular dystrophy, our results indicate that at least for X-chromosomal disorders the male:female mutation rate of a disease is determined by its proportion of the different mutation types.

Base Sequence↗
PubMed1996

[Acute abdomen in extensive thrombosis in the inferior vena cava collateral circulation].

Variations of the inferior vena cava (IVC) because of either embryonal malformations or postthrombotic changes are not uncommon. The clinical symptoms include repetitive thrombotic events. We report on an atypical case of acute abdomen resulting from thrombotic occlusion of the IVC and the right renal vein as well as of the collateral vessels.

Abdomen, Acute↗
PubMed1996

Depletion of naive T cells of the peripheral lymph nodes abrogates systemic antitumor protection conferred by IL-2 secreting cancer vaccines.

It has been postulated that IL-2 secreting cancer vaccines establish antitumor immunity because the cytokine acting in a paracrine fashion would deliver a helper signal directly to the T cells making contact with the modified tumor cells at the site of vaccination. However, patterns of lymphocyte recirculation cannot be reconciled with the above direct interaction model: only primed memory T cells rather than naive T lymphocytes patrol the periphery, while naive T cells travel to the peripheral lymph nodes, where priming occurs. We have found that in vivo treatment of mice with the antibody MEL-14 directed against L-selectin, which is a molecule expressed at high levels on naive T cells, can completely abrogate protection against a mouse melanoma conferred by an IL-2 secreting vaccine. Since mouse memory CD4 and CD8 T cells are L-selectin-low, only migration of naive T cells is perturbed by the in vivo antibody blockade. Thus, priming of naive T cells in the draining lymph node is a critical step for the successful vaccination by IL-2 secreting cancer vaccines. Such priming is performed most efficiently by professional antigen presenting cells; consequently, these data also imply that allogeneic origin of tumor vaccines may not exclude successful vaccination.

Animals↗
PubMed1996

Devices for blood pressure self-measurement: present and future.

Presented are new developments over recent years for blood pressure meters for self-measurement, which increase the accuracy of measurement, improve the handling of instruments, reduce discomfort during the measurement, make the instrument more compact and easier to transport. Special attention is focused on new developments which can eliminate measurement errors, especially in the elderly.

Algorithms↗
PubMed1996

A third kidney transplant: cost-effective treatment for end-stage renal disease?

Given the organ donor shortage, some question whether a third kidney transplant can be justified. We studied the outcome of 51 third transplants (mean age 28 +/- 2 yr) done between 1 January 1985 and 31 December 1994. We compared hospital stay (mean +/- S.E.), cost, readmissions, readmission days, and outcome of third (vs. first and second) transplants. We found that patient survival for third transplants was equivalent to first and second transplants; graft survival was not as good. However, when third transplant recipients with recurrent disease (specifically, hemolytic uremic syndrome and focal sclerosis) were excluded from our analysis, we found no difference in 5-yr graft survival (vs. first or second transplant recipients). Of the 51 third transplant recipients, 41 had a cadaver donor transplant. Third cadaver transplant recipients tended to have a longer hospital stay (p = NS) than first cadaver transplant recipients but had no more readmissions or readmission days than first and second cadaver transplant recipients. Employment data are available for 28 third transplant recipients; 16 (57%) are currently working or going to school. Of the 21 recipients who responded to quality of life questionnaires, 17 (81%) reported being healthy and all 21 (100%) said transplantation was not a drawback to their health. We conclude that third transplants should be considered for selected patients with renal failure whose first and second transplants have failed. Such patients can often be successfully transplanted.

Actuarial Analysis↗
PubMed1996

[Hemodynamic and humoral effects of parenteral therapy with intravenously administered ACE inhibitor quinaprilat in patients with advanced heart failure].

The hemodynamic and neurohumoral effects of single and multiple doses of intravenous quinaprilat were assessed and compared with placebo in a double-blind design. The study group included 50 patients aged between 33 and 76 years with NYHA Class III and IV heart failure. The patients were randomized into three treatment groups to receive low (0.5 and 1.0 mg), medium (1.0 and 2.5 mg), or high (5.0 and 10.0 mg) intravenous doses of quinaprilat or placebo on day 1, and, based on the responses, q6h on two further days. The hemodynamic parameters were determined by right-heart catheterization. Quinaprilat is the active metabolite of quinapril, an ACE inhibitor with high affinity for the angiotensin converting enzyme, which is formulated for oral application. Compared with placebo, single and multiple doses of quinaprilat increased cardiac index by 25% (p < 0.05) and simultaneously decreased both peripheral vascular resistance by 25% (p < 0.05) and left ventricular filling pressures by 33% (p < 0.05). There was a dose-related decrease in mean right atrial pressure by 47% (p < 0.05) without significant heart rate changes (-3-5 bpm). The mean artery pressure showed a dose-related maximum decrease of 4-9 mm Hg 45-60 min after single-dose quinaprilat and of 7-10 mm Hg (p < 0.05) after repetitive dosing. Maximum changes were observed 15-90 min after drug application. The hemodynamic changes after multiple-dose quinaprilat were similar to those observed following single doses and generally persisted during the total observation period of 6 h. Compared with placebo, quinaprilat reduced ACE activity and angiotensin II and aldosterone concentrations, and increased plasma renin activity. There were no significant changes with regard to plasma catecholamines and the atrial natriuretic factor, although a slight decrease could be observed. The study results obtained in patients with advanced heart failure support both the safety and favorable hemodynamic and neurohumoral effects of intravenous quinaprilat over an observation period of 3 days.

Adult↗
PubMed1996

Adenovirus-enhanced receptor-mediated transferrinfection for the generation of tumor vaccines.

Cancer vaccines are genetically modified tumor cells that, by cytokine secretion or by expression of costimulatory molecules, are capable of mobilizing the host's immune system to destroy tumor cells. We have used adenovirus-enhanced transferrinfection (AVET) for the generation of cancer vaccines. This is a highly efficient method to deliver various genes into a large proportion of tumor cells, making further selection unnecessary. We found in the mouse M-3 melanoma model that two consecutive vaccinations with transfected cells secreting IL-2 protect animals from tumor development by a subsequent challenge, and result in long-lasting tumor-specific immunity dependent on both CD4+ and CD8+ T cells. Patterns of lymphocyte recirculation and the need for CD4+ T cells indicated that the role of IL-2 is not merely local 'replacement of help', as has been proposed before. Instead, our findings suggest a three-stage process for the generation of effector T cells after vaccination with IL-2 secreting tumor cells: (1) tumor antigen uptake and processing at the site of injection by APCs, (2) migration of APCs into the regional draining lymph nodes where T-cell priming occurs, and (3) recirculation of activated cytotoxic T cells, that recognize and eliminate distant tumor cells. This model also implies that allogeneic tumor cells or synthetic tumor antigens may be used with success in future cancer vaccines.

Adenoviridae↗
PubMed1995

[Percutaneous extracorporeal circulation in cardiogenic shock caused by combined poisoning with methyldigoxin, nifedipine and indapamide].

HISTORY AND FINDINGS: A 38-year-old man with endogenous depression was found comatose and with gasping respiration. Empty packets of tablets pointed to poisoning with methyldigoxin, nifedipine and indapamide. Pupils reacted slowly to light and no peripheral blood pressure could be measured. TREATMENT AND COURSE: Routine resuscitation measures (intubation, mechanical ventilation, external cardiac massage and drugs) were undertaken during transport to hospital where, in addition to further symptomatic treatment, digoxin antibodies were administered, but without noticeable effect. Percutaneous cardiopulmonary bypass was therefore undertaken. It achieved a cardiac output of 3.2l and a systolic pressure of 80 mm Hg: a stable rhythm and circulation were obtained within 15 hours indicating that electromechanical uncoupling had for the time being been overcome. The EEG suggested a midbrain syndrome. After another 18 hours of mechanical ventilation and symptomatic treatment asystole suddenly occurred. Renewed resuscitation procedures were not undertaken because of the very poor neurological state and prognosis. CONCLUSION: Although haemodynamic stabilization was only temporarily achieved and the patient's death could not be prevented because of adverse pretreatment conditions, the application of percutaneously implantable, transportable heart-lung machine appears to be justified in cases of intoxication with cardio- and vasodepressive substances.

Adult↗