PubMed Health⌕ Search

Biomedical subjects

Walter Krause

Publications and source records attributed to Walter Krause.

At least 19 recordsLinked to original sources
PubMed2006

Skin diseases in consequence of endocrine alterations.

The skin is a target organ of several hormones. Specific diseases appear in consequence of hypo- or hypersecretion of endocrine organs, particularly in the elderly patient. There, knowledge of skin alterations is important not only for dermatologists, but also for endocrinologists and other physicians, because a clinical diagnosis of the underlying disease is often possible. In this review, a number of representative skin diseases having an endocrinological basis are described. These include acanthosis nigricans, diseases due to alterations of androgen metabolism, carcinoid syndrome, diseases due to alterations of corticosteroid metabolism, diseases in association with diabetes mellitus, diseases due to alterations of estrogen metabolism, genetic syndromes including dermatological and endocrine symptoms, the glucagonoma syndrome, diseases due to dysfunctions of growth hormone secretion, diseases in association with Merkel cells of the skin, diseases due to dysfunctions of the thyroid gland, diseases to alteration of vitamin D metabolism, and vitiligo and disorders of pigmentation.

Androgens↗
PubMed2006

Identification of evolutionary conserved mouse sperm surface antigens by human antisperm antibodies (ASA) from infertile patients.

PROBLEM: The presence of antisperm antibodies (ASA) in semen may impair sperm function leading to immunological infertility. The aim of the study was to identify the evolutionary conserved antigens on mouse sperm surface that react with human ASA in order to study the mechanism of autoimmune infertility. METHODS OF STUDY: The binding of human ASA to mouse sperm was investigated by means of indirect immunofluorescence. 2D-electrophoresis was applied to separate the biotin-labelled mouse membrane proteins using isoelectric focusing followed by polyacrylamide gel electrophoresis. Cognate antigens of ASA from seminal plasma of infertile patients were analysed by Western blotting. Performing avidin-blots it was detected which of the proteins recognized were sperm surface proteins. The spots of interest were analysed by means of mass spectrometry. RESULTS: ASA bound most frequently (36%) to the post-acrosomal region and to the midpiece of mouse spermatozoa. About 30% of ASA recognized apo lactate dehydrogenase (LDHC4) as a cognate antigen, 30% voltage-dependent anion channel (VDAC2). ASA of 20% bound to outer dense fibre protein and 20% of samples recognized glutathione S-transferase mu5. CONCLUSIONS: Human ASA bound to specific cognate antigens of mouse spermatozoa, offering the possibility to study their functional relevance in the mouse model.

Animals↗
PubMed2005

Stress reduction in male infertility patients: a randomized, controlled trial.

OBJECTIVE: To assess the impact of preparatory information about the fertility workup on the patients' well-being. DESIGN: Two-group, randomized controlled study. SETTING: An andrology clinic. PATIENT(S): Two hundred fifty men enrolled for fertility workup. INTERVENTION(S): A two-page leaflet with preparatory information about the fertility workup, which was mailed to half of the participants after they had made an appointment. MAIN OUTCOME MEASURE(S): Questionnaire score for infertility-related distress at clinic attendance, proportion of participants that still had not attended 6 months after the scheduled appointment. RESULT(S): Distress scores and the proportion of nonattendees were significantly reduced in the group receiving the leaflet. An additional analysis revealed that 55% of the receivers did not know that the andrology clinic has its own web site, which was mentioned in the leaflet several times. CONCLUSION(S): Although it is uncertain how many patients actually read a routinely sent leaflet, preparatory information in written form is beneficial, at least for a significant subgroup of men who consider undergoing fertility workup. Fertility services might reduce the number of nonattendees by sending out leaflets.

Adult↗
PubMed2005

Polymorphisms associated with the DAZ genes on the human Y chromosome.

The human Y chromosome is unique in that it does not engage in pairing and crossing over during meiosis for most of its length. Y chromosome microdeletions, a frequent finding in infertile men, thus occur through intrachromosomal recombination, either within a single chromatid or between sister chromatids. A recently identified polymorphism associated with increased risk for spermatogenic failure, the gr/gr deletion, removes two of the four Deleted in Azoospermia (DAZ) genes in the AZFc region on the Y-chromosome long arm. We found the likely reciprocal duplication product of gr/gr deletion in 5 (6%) of 82 males using a novel DNA-blot hybridization strategy and confirmed the presence of six DAZ genes in three cases by FISH analysis. Additional polymorphisms identified within the DAZ repeat regions of the DAZ genes indicate that sister chromatid exchange plays a significant role in the genesis of deletions, duplications, and polymorphisms of the Y chromosome.

Alleles↗
PubMed2005

Testosterone supplementation in the aging male: which questions have been answered?

PURPOSE: There is no consensus on possible benefits and risks of testosterone supplementation. Here we review various controlled studies of testosterone supplementation in aging males. METHODS: We performed a PubMed search using the terms "testosterone/therapeutic use" with the limits " > 65 years of age", "randomized controlled clinical trials", and "male gender", starting in 1999. RESULTS: Forty-three articles have been published since 1999. Some of these studies also included patients in middle-age or younger. Findings reported in these articles were not entirely consistent. After weighting studies by the number of patients, hints are found that testosterone supplementation increases bone mass, lean body mass, muscle mass and hematopoiesis, and improves sexual functioning and perhaps mood, but does not affect serum lipids, cardiovascular parameters, prostate-specific antigen level, or cognition. Considering studies including only men older than 65 years, and in which testosterone supplements were compared with placebo treatment, slightly different results are obtained. In these patient groups, testosterone does not improve sexual function or mood. CONCLUSION: The overall benefit of testosterone supplementation for the aging male remains unclear. Any supplementation in men with age-normal testosterone levels only on grounds of subjective symptoms is not advisable.

Adult↗
PubMed2005

The role of antisperm antibodies during fertilization and for immunological infertility.

Antisperm antibodies (ASA) occur in men and in women. In the male they may cause an autoimmune disease, 'immune infertility'. In order to understand the functional relevance of ASA it is necessary to characterize the cognate antigens of ASA by different methods. In the literature, several immunologically characterized sperm proteins--as cognate antigens of naturally occurring ASA or of artificially produced antibodies--are quoted with respect to different sperm functions in the course of fertilization: cervix mucus penetration, zona binding, zona penetration, oolemma binding, and pronucleus formation. In a number of these functions, sperm proteins were already identified as cognate antigens of ASA. As practical consequences of the research on ASA-related sperm proteomics those ASA will be identified, which decrease male fertility by inhibiting sperm functions that are essential for fertilization.

Animals↗
PubMed2003

Characterization of spermatozoa surface antigens by antisperm antibodies and its influence on acrosomal exocytosis.

PROBLEM: Antisperm antibodies (ASA) are the main cause of immunological infertility, they impair sperm functions by binding to the sperm membrane. The aim of this study was to characterize highly enriched sperm membrane proteins by 2-D-electrophoresis and to identify membrane antigens binding ASA and to evaluate the influence of ASA on the acrosome reaction (AR). METHOD OF STUDY: Sperm membrane proteins were separated by 2-D-electrophoresis and antigens were identified by immunoblotting with ASA from seminal plasma samples of infertile men. The influence of ASA on the AR were observed and determined by means of flowcytometry. RESULTS: A total of 18 antigens were identified by using ASA from seminal plasma. Six of the recognized proteins were analyzed by means of mass spectrometry and peptide matching: HSP70 and HSP70-2, disulfide-isomerase-ER60, caspase-3 and two subunits of the proteasome (component-C2 and zeta-chain). ASA from seminal plasma are able to enhance the AR in donor-spermatozoa. CONCLUSION: The biochemical identification of these proteins will be helpful to understand the mechanism by which ASA impair sperm function and the fertilization process. Spermatozoa, in which the AR was prematurely induced by ASA, will not be able to fertilize anymore.

Acrosome Reaction↗
PubMed2003

Immune infertility: towards a better understanding of sperm (auto)-immunity. The value of proteomic analysis.

Antisperm antibodies (ASA) in the male cause an autoimmune disease 'immune infertility'. It has to be clarified whether each antibody binding to an antigen, which is identified on the sperm surface, also influences sperm function. In the past, the clinical interest in ASA was hampered by the fact that a standardized assay for the detection of ASA was lacking. There are several methods to characterize the cognate antigens of ASA. In the following article, reports from the recent literature of immunologically characterized sperm proteins-as cognate antigens of naturally occurring ASA or of artificially produced antibodies-will be quoted with respect to different sperm functions. As a practical consequence of the research on ASA-related sperm proteomics, those ASA that decrease male fertility by inhibiting sperm functions essential for fertilization will be identified.

Antibodies↗
PubMed2002

Seasonal variations in human seminal parameters.

OBJECTIVES: To obtain data on seasonal variations of sperm parameters in an andrology laboratory. STUDY DESIGN: Semen parameter values and hormone values of 2454 patients attending our infertility clinic between 1990 and 1997 were analysed. Seasonal trends were calculated using the method of Edwards [Ann. Hum. Genet. 25 (1961) 83]. RESULTS: The total group of mean sperm count did not show a significant variation, but a significant circannual trend occurred of patients born in the groups 1950-1954, 1955-1959 and 1965-1969. A significant variation of acrosin activity occurred with a maximum in March. The other parameters did no show significant variations. CONCLUSIONS: The knowledge on circannual variation of semen parameters and hormone values may be of value in diagnostic and therapeutic decisions in reproductive medicine.

Acrosin↗
PubMed2002

Serum levels of inhibin B and follicle-stimulating hormone may predict successful sperm retrieval in men with azoospermia who are undergoing testicular sperm extraction.

To evaluate the predictive power for sperm retrieval in testicular sperm extraction of inhibin B and FSH levels in the peripheral blood in association with the testicular histology. Clinical study. Departments of andrology and urology at a university hospital.Fifty-two patients with azoospermia. Determination of serum levels of FSH and inhibin B in men with azoospermia. Testicular incision and histological investigation as well as testicular sperm extraction (TESE) followed by intracytoplasmic sperm injection were performed. Comparison of hormone levels with different histological features of seminiferous tubules (normospermatogenesis, hypospermatogenesis, and Sertoli cell-only syndrome) and TESE outcome.With respect to the histological proof of spermatozoa, the sensitivity of the FSH levels >10 mU/mL was 82%, and of inhibin B levels, <79 pg/mL, 78%; the specificity was 80% for both hormone levels. With respect to the successful sperm extraction in the TESE procedure, the sensitivity of the FSH levels was 58% and the specificity was 50%; and the sensitivity of inhibin B levels was 52.5% and the specificity was 60%. Inhibin B and FSH levels are correlated with spermatogenetic activity. The combination of the two parameters is currently the best predictor for the presence of sperm, which may be found in TESE. However, the prediction is not absolutely reliable: TESE can be also successful when both hormone levels are outside the threshold levels.

Follicle Stimulating Hormone↗