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Biomedical subjects

C Müller

Publications and source records attributed to C Müller.

At least 901 records · Page 50Linked to original sources
PubMedDate not supplied

Autometallographic detection of mercury in testicular tissue of an infertile man exposed to mercury vapor.

A 25-year-old male patient presented with unexplained infertility. Semen analysis showed azoospermia or severe oligoasthenoteratospermia with elevated serum FSH. The history revealed that he had been employed in a chemical factory for 5 years working with chloralkali-electrophoresis. Mercury concentrations in hair, blood, and urine samples were considerably above levels of unexposed controls. Bilateral testicular biopsies revealed marked interstitial lymphatic infiltration. About 33% of the tubules analyzed showed a Sertoli-cell-only (SCO) syndrome and tubular atrophy. Fewer than 4% of tubules showed qualitatively intact spermatogenesis. Autometallographic (AMG) analysis of the biopsy material yielded silver-enhanced mercury grains, primarily in the interstitial Leydig cells. Sections from a control patient not exposed to mercury were devoid of mercury grains.

Adult↗
PubMedDate not supplied

Lack of correlation between cadmium in seminal plasma and fertility status of nonexposed individuals and two cadmium-exposed patients.

Cadmium concentrations were determined in semen samples of 12 men with proven fertility (group I) and 44 normozoospermic patients (group II) as well as 118 unselected patients of an infertility clinic (group III) and 2 industrial workers with occupational exposure to cadmium. Mean cadmium concentrations in seminal plasma for groups I, II, and III did not show significant differences: 0.38 +/- 0.64; 0.43 +/- 0.69; 0.44 +/- 0.73 (mean +/- SD, micrograms/L), but the two cadmium-exposed patients revealed exceptionally high cadmium levels: 3.46 micrograms/L and 2.99 micrograms/L, respectively. There was no significant correlation between seminal cadmium concentrations and conventional semen parameters or between cadmium concentration and the fertility status of the patients. However, mean cadmium concentrations in seminal plasma of normozoospermic patients were higher in the group of smokers (0.55 +/- 0.81 micrograms/L), compared with the group of nonsmokers (0.42 +/- 0.67 micrograms/L), and there was a weak correlation between cadmium concentration and number of cigarettes consumed per day.

Adult↗
PubMedDate not supplied

The prevalence of incipient tubular dysfunction, but not of glomerular dysfunction, is increased in patients with diabetes onset in childhood.

The study investigated the prevalence of incipient renal dysfunction in two cohorts with identical duration of type I diabetes but with childhood or adult onset of the disease. The pattern of glomerular (albumin, alb) and tubular (alpha(1)-microglobulin, alpha(1)-m, and N-acetyl-beta-D-glucosaminidase, NAG) urinary protein excretion was studied in 97 patients with diabetes onset before the age of 16 years and in 53 patients with manifestation of the disease after this age. Diabetes duration was comparable in both groups [9.0 years (1.5-40.0) versus 9.0 (1.0-34.0), p 30 microg/g creatinine), patients with diabetes onset in childhood showed significantly higher excretion of NAG compared to those with diabetes onset after the age of 16. The excretion of both tubular markers (alpha(1)-m and NAG) correlated significantly with HbA(1c)-values in both groups. In multiple regression analysis, tubular proteinuria (alpha(1)-m) and diabetes duration correlated significantly to microabuminuria (multiple R = 0.60, p < 0.001). These data suggest that there is no difference concerning the prevalence of incipient diabetic glomerulopathy between patients with an early or a late onset of diabetes. However, a more frequent impairment of tubular function was found in young patients with diabetes onset in childhood, which might be due to a non-optimal glycemic control in this population.

Acetylglucosaminidase↗
PubMedDate not supplied

[Supply of iodine during pregnancy--an inventory in Berlin, Germany].

BACKGROUND: Iodised salt was introduced in Germany in the early 1980s. A nation-wide study in 1996 showed that iodine levels among the population had improved since the introduction of the supplementation. The study did not separately investigate the iodine status of pregnant women. In our prospective study, we used three parameters to assess the iodine levels among pregnant women. PATIENTS AND METHODS: Between October 1999 and February 2000, we asked 109 German-speaking patients seeking prenatal care in our clinic to participate. Following informed consent, we measured goiter volume by ultrasound and collected venous blood (serum) and urine samples. We asked patients about any history of thyroid gland illnesses and about iodine supplementation which is generally given to pregnant patients in Germany. The blood and urine samples were stored at -18 degrees C until measurement. We used the iodine-creatinine-ratio to measure ioduria. Iodine was measured using the Cer-Arsenite-method (Dade-Behring). The thyroglobulin concentration in serum was measured using RIA. RESULTS: The mean iodine-creatinine ratio was 181 +/- 109 microg/g, 20.4 % of the patients had a ratio between 50 and 100 microg/g which is defined as iodine deficiency I degrees (WHO). 8.7 % of the patients had thyreoglobulin levels above the cut-off value of 50 ng/ml. 12.6 % of the patients had a goiter (volume > 18 ml). 58 % of the patients were taking iodine supplements. These patients had significantly higher iodine-creatinine ratio levels (204 microg/g vs. 148 microg/g, P = 0.007) and lower serum thyroglobulin levels (38.4 vs. 34.1 pmol/l, P = 0.06) than non-supplemented patients. CONCLUSIONS: The prevalence of goiter reflects an extended period of iodine deficiency. Using laboratory methods, up to 20.4 % of pregnant women were identified as having an iodine deficiency which indicates the need for a general iodine supplementation during pregnancy.

Adult↗
PubMedDate not supplied

[Randomised trial of acupuncture compared with conventional massage and "sham" laser acupuncture for treatment of chronic neck pain - range of motion analysis].

AIM: The aim of this study was to compare the effects of acupuncture on active motion of the cervical spine in patients with chronic neck pain with those of "sham" laser acupuncture and massage. MATERIAL AND METHODS: 177 patients with chronic neck pain were included in this prospective, randomized, placebo-controlled study. The patients were allocated by external randomization to five treatments over three weeks with acupuncture, massage and "sham" laser acupuncture. The range of active motion was measured by means of a 3D ultrasound real time motion analyzer. RESULTS: The analysis of cervical motion in three directions showed the largest increase in range of motion 14 days after acupuncture. Compared to massage, a significant improvement in total range of motion was seen in those patients treated by acupuncture immediately (p = 0,03) and one week (p = 0,03) weeks after therapy. There was no significant difference in those patients treated by sham laser acupuncture. CONCLUSION: The results of the study indicate that acupuncture is superior to conventional massage for improving active range of motion in patients with chronic neck pain. Because of its positive effects, its acceptance among patients and the lack of severe side effects, acupuncture can be recommended for the treatment of chronic neck pain, although there was no significant difference in results between "sham" laser acupuncture and acupuncture.

Acupuncture Therapy↗
PubMedDate not supplied

Effect of angiotensin converting enzyme (ACE) and angiotensins on human sperm functions.

The presence of components of the renin angiotensin system (RAS) and specific receptors of angiotensin II in the female and male reproductive tract supports the hypothesis that reproductive functions may be controlled by RAS. Therefore, the present study investigated the influence of ACE and angiotensins on sperm functions and the sperm-egg interaction. The experiments did not indicate direct effects of ACE on the capacitation process or acrosome reaction. Release of ACE from human spermatozoa during capacitation was not related to their ability to undergo acrosome reaction after stimulation with ionophore. Therefore, ACE release does not seem to be a useful clinical marker for human sperm capacitation. However, decreased binding of human spermatozoa to the oolemma of zonafree hamster oocytes after inhibition of ACE by captopril indicates that kininase II is involved in sperm-egg interactions. In contrast to other studies, incubation with captopril had no influence on sperm binding to the zona pellucida. Because effects of ACE on sperm-egg interactions but not on capacitation or acrosome reaction were observed, several experiments were performed to study the influence of substrates and products on the acrosome reaction. Angiotensin II induced the acrosome reaction dose-dependently, whereas angiotensin I had no effect on the acrosome reaction. The effect of angiotensin II on acrosome reaction seems to be calcium-dependent and mediated by protein kinases. Since a specific type 2 angiotensin II receptor inhibits the acrosome reaction induced by angiotensin II, this subtype of receptors may be present at the surface of sperm heads. Another clue for the presence of type 2 receptors on human spermatozoa is the finding that pertussis toxin did not inhibit the angiotensin II induced acrosome reaction. In contrast to type 1 angiotensin II receptors, type 2 receptors are known to be G-protein independent.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMedDate not supplied

Induction of acrosome reaction by low temperature is comparable to physiological induction by human follicular fluid.

The acrosome reaction was induced by means of low temperature or human follicular fluid (FF) in spermatozoa from 18 patients. Live acrosome-reacted spermatozoa were determined with the triple-stain technique. Both inducers of acrosome reaction had a highly significant correlation with the percentage of acrosome-reacted spermatozoa after induction of the acrosome reaction: (r = 0.9190; P < 0.0001) and the inducibility of AR (r = 0.8472; P < 0.0001). This might indicate that both the non-physiological (low temperature) and the physiological (FF) inducers use the same signal transduction pathway, and demonstrates the usefulness of low temperature induction for diagnostic purposes.

Acrosome↗
PubMedDate not supplied

Protein C activators from snake venoms and their diagnostic use.

Proteinases converting the zymogen protein C (PC) of vertebrates into activated PC have been detected in several snake venoms. Most PC activators have been purified from venom of snake species belonging to the genera of the Agkistrodon complex. Unlike the physiological, thrombin-catalyzed PC activation reaction which requires thrombomodulin as a cofactor, most snake venom activators directly convert the zymogen PC into the catalytically active form which can easily be determined by means of coagulation or chromogenic substrate techniques. Due to this feature, the fast-acting PC activator Protac from Agkistrodon contortrix contortrix (southern copperhead snake) venom has found a broad application in diagnostic practice for the determination of disorders in the PC pathway. Recently, screening assays for the PC pathway have been introduced, based on the observation that the PC pathway is probably the most important physiological barrier against thrombosis.

Agkistrodon↗
PubMedDate not supplied

Improvement of lung preservation -- from experiment to clinical practice.

BACKGROUND: Reperfusion injury represents a severe early complication following lung transplantation. Among the pathogenetic factors, the high potassium content of Euro-Collins(reg) solution is discussed. MATERIAL AND METHODS: In a pig model of orthotopic left-sided lung transplantation we investigated the effect of Euro-Collins solution (EC: n = 6) versus low potassium dextran (LPD: Perfadex: n = 6). Sham-operated (n = 6) animals served as control. Transplant function, cellular energy metabolism and endothelial morphology served as parameters. In a clinical investigation, 124 patients were evaluated following single (EC: n = 31; LPD n = 37) or double (EC: n = 17; LPD n = 39) lung transplantation, whose organs where preserved with EC (n = 48) or LPD (n = 76). Duration of ischemia, duration of ventilation and stay on ICU were registered. Primary transplant function was evaluated according to AaDO(2) values. Cause of early death (30 days) was declared. RESULTS: Experimental results: After flush with EC and 18 h ischemia, a reduction of tissue ATP content (p < 0.01 vs inital value and LPD) was noted. Endothelial damage after ischemia was severe (p < 0.05 vs control), paO(2) was significantly decreased. CLINICAL RESULTS: In the LPD group, duration of ischemia was longer for the grafts transplanted first (SLTx and DLTx: p = 0.0009) as well as second (2. organ DLTx: p = 0.045). Primary transplant function was improved (day 0: SLTx: p = 0.0015; DLTx: p = 0.0095, both vs EC). Duration of ventilation and stay on ICU were shorter (n.s.). Reperfusion injury-associated death was reduced from 8% (EC) to 0 (LPD). CONCLUSION: In experimental lung preservation, LPD lead to an improved graft function. These results were confirmed in clinical lung transplantation. Clinical lung preservation, therefore, should be carried out by use of LPD.

Adult↗
PubMedDate not supplied

Veno-occlusive disease in a fetus caused by pyrrolizidine alkaloids of food origin.

We report the occurrence of veno-occlusive disease in a preterm neonate who was symptomatic with hepatomegaly and ascites and was delivered by caesarean section for threatening fetal asphyxia and died shortly afterwards. Post mortem examination revealed veno-occlusive disease typical for pyrrolizidine alkaloid poisoning. The content of pyrrolizidine alkaloids in the liver could be confirmed. Analysis of a herbal mixture which was used for cooking in the family revealed high amounts of the respective alkaloids clarifying the source of the poison and the causal relationship.

Female↗
PubMedDate not supplied

The intestinal immune system and its relation to disease.

The essential protective structure against the heavy enteric antigenic burden, the gut mucosa, prevents penetration of noxious agents, but allows a minimal exchange of large molecules and particles between the gut lumen and the 'milieu intérieur' of the body. M cells in the follicle-associated epithelium of the gut, ideal gateways for the presentation of enteric antigens to the cells of the gut-associated lymphoid tissue (GALT), are also weak links in the mucosal barrier, and may provide access for various microorganisms. The afferent limb of the GALT consists of distinct aggregates of lymphoid cells located in Peyer's patches, the vermiform appendix and the solitary lymphatic follicles, and of the mesenteric lymph nodes. The efferent limb subsumes the diffusely scattered mucosal leukocytes, mainly lymphocytes and plasma cells. Intraepithelial and mucosal T lymphocytes are instrumental in launching local immune responses, producing lymphokines, and in the specific lysis of virally infected cells. Antigenic stimulation of the GALT results in local secretion of antibodies, or in suppression of systemic immunologic responses to ingested antigens ('oral tolerance'). Poorly controlled mucosal immune responses result in organ-specific diseases. Extranodal lymphomas that mimic structures of the GALT may arise on a background of inflammatory or immunologic (autoimmune) disorders.

Appendix↗
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Immunohistochemical localization of 11-hydroxysteroid dehydrogenase in rat kidney with monoclonal antibody.

Monoclonal antibody (MAb) against 11-hydroxysteroid dehydrogenase (11-HSD) has been raised by immunization of female balb/c mice. 11-HSD from solubilized rat renal microsomal protein could be bound in a modified ELISA using antimouse IgG and MAb against 11-HSD. On Western blots of solubilized rat renal microsomes the MAb recognized a single protein band of an approximate molecular weight of 35 kD. Immunohistochemical staining of rat renal tissue with the above MAb and the APAAP staining technique displayed a heterogenous reginal and subcellular distribution: glomeruli and arterioles were practically devoid of specific staining, as were epithelial cells in inner and outer medulla. Intense immunostaining was observed in PCT and particularly in PST, appearing granular with highest density around the nuclei. Here the enzyme bound to intracellular membranes may exert an autocrine function such as signal inactivation. In contrast to cortex, staining of interstitial cells was observed in renal medulla. The latter localization is compatible with the concept of a paracrine function of 11-HSD which might prevent corticosterone from gaining access to collecting duct cells.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

The non-mevalonate isoprenoid biosynthesis of plants as a test system for new herbicides and drugs against pathogenic bacteria and the malaria parasite.

Higher plants and several photosynthetic algae contain the plastidic 1-deoxy-D-xylulose 5-phosphate/2-C-methyl-D-erythritol 4-phosphate pathway (DOXP/MEP pathway) for isoprenoid biosynthesis. The first four enzymes and their genes are known of this novel pathway. All of the ca. 10 enzymes of this isoprenoid pathway are potential targets for new classes of herbicides. Since the DOXP/MEP pathway also occurs in several pathogenic bacteria, such as Mycobacterium tuberculosis, and in the malaria parasite Plasmodium falciparum, all inhibitors and potential herbicides of the DOXP/MEP pathway in plants are also potential drugs against pathogenic bacteria and the malaria parasite. Plants with their easily to handle DOXP/MEP-pathway are thus very suitable test-systems also for new drugs against pathogenic bacteria and the malaria parasite as no particular security measures are required. In fact, the antibiotic herbicide fosmidomycin specifically inhibited not only the DOXP reductoisomerase in plants, but also that in bacteria and in the parasite P. falciparum, and cures malaria-infected mice. This is the first successful application of a herbicide of the novel isoprenoid pathway as a possible drug against malaria.

Animals↗