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Biomedical subjects

E Zimmermann

Publications and source records attributed to E Zimmermann.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Obstructive sleep apnea in older patients after the closure of a tracheostoma].

BACKGROUND AND OBJECTIVE: The closure of tracheostomies may postoperatively induce an obstructive sleep apnea (OSA) even in patients who never complained about sleep related breathing disorders before they underwent tracheotomy. The present study was designed to evaluate, whether OSA appears after the tracheostomy has been airtightly blocked and if so, whether there are typically illnesses predictive for OSA after operative closure of tracheostomies. PATIENTS AND METHODS: Twelve consecutive patients (3 male; 9 female; mean age 66 years), who addressed our clinic for operative closure of their tracheostomies were enrolled in this study over a period of 18 months. On basis of patient's history and clinical findings the patients were divided into two groups. Group A included 7 patients with laryngeal pathologies and group B included 5 patients with normal larynges. All patients underwent a 12-channel polysomnography (PSG) with airtightly blocked tracheostomies preoperatively. RESULTS: In 5 patients a mild OSA and in one patient a severe OSA was diagnosed by PSG. The patients of group A with laryngeal pathologies were older, had a lower Body Mass Index (BMI) and a higher Apnea-Hypopnea Index than patients of group B (p < 0.05). CONCLUSION: Laryngeal pathologies in the elderly might facilitate the development of OSA after operative closure of tracheostomies. Based on the results postoperative reevaluation is recommended for all elderly patients with laryngeal abnormalities after operative closure of the tracheostomy.

Aged↗
PubMed2000

Cimetidine absorption and elimination in rat small intestine.

The purpose of this study was to determine the characteristics of intestinal absorption and metabolism of cimetidine. The initial finding of the appearance of cimetidine sulfoxide in rat and human jejunum from cimetidine perfusions had prompted an isolation of mucosal membrane transport and enterocyte metabolism contributions in earlier membrane vesicle and microsomal studies, respectively. In this report, perfusion studies in rat small intestine detail regional differences in intestinal elimination. Cimetidine S-oxide appears to a significantly greater extent in the jejunum compared with the ileum. Jejunal metabolite appearance is shown to be a function of the pH-dependent intracellular uptake of cimetidine. Cimetidine permeability decreases with increasing perfusion concentration in both jejunum and ileum. Similar permeability magnitudes and concentration dependence are observed in both regions. Perfusion studies with inhibitors of cimetidine mucosal transport and inhibitors of microsomal S-oxidation provide an inhibition profile suggesting that jejunal cimetidine permeability decreases with increasing intracellular cimetidine concentration. The data support a reduction in paracellular cimetidine absorption as controlled by intracellular cimetidine. This inference is drawn on the basis of mass balance. Because significant appearance of cimetidine S-oxide was previously found in human jejunal perfusions, this region-dependent intestinal elimination process detailed in rats may be relevant to drug plasma-level double peaks observed in clinical studies. Saturation of jejunal metabolism at typical oral doses may limit paracellular absorption of cimetidine in the jejunum and contribute to the double peak phenomenon and to absorption variability.

Administration, Oral↗
PubMed1999

Regulation of paracellular absorption of cimetidine and 5-aminosalicylate in rat intestine.

PURPOSE: Isolating the relative contributions of parallel transcellular and paracellular transport to the intestinal absorption of small hydrophilic molecules has proven experimentally challenging. In this report, lumenal appearance of drug metabolite is utilized as a tool to assess the contribution of paracellular transport to the absorption of cimetidine and 5-aminosalicylate (5ASA) in rat small intestine. METHODS: Steady-state intestinal absorption and elimination of cimetidine and 5ASA were studied in single-pass intestinal perfusions in rats. RESULTS: Both drugs were metabolized in intestinal epithelia with subsequent metabolite secretion into the intestinal lumen. Jejunal cimetidine absorption decreased with increasing perfusion concentration while the ratio of lumenal metabolite to lumenal drug loss increased. Cimetidine uptake at perfusion concentrations above 0.4 mM resulted in over 80% drug elimination into the jejunal lumen. Inhibition of intracellular metabolism of cimetidine by methimazole did not alter epithelial uptake but totally abolished transepithelial cimetidine flux indicating an elevation of intracellular cimetidine. Similarly, co-perfusion of 5ASA with cimetidine and methimazole totally abolished 5ASA absorption but increased lumenal levels of N-acetyl 5ASA indicating an increase in intracellular uptake of 5ASA. CONCLUSIONS: Cimetidine and 5ASA absorption across rat jejunal epithelia are exclusively paracellular. Elevation of intracellular cimetidine, inferred from mass balance considerations, restricts paracellular transport of both drugs.

Anesthesia↗
PubMed1999

Calcium ketoglutarate versus calcium acetate for treatment of hyperphosphataemia in patients on maintenance haemodialysis: a cross-over study.

Since dietary restrictions and phosphorus removal by haemodialysis (HD) are not sufficient to control serum phosphate (s-phosphate) levels in dialysis patients the use of oral phosphate binders is mandatory. Calcium ketoglutarate (CaKE) is an analogue of glutamic acid exerting phosphate binding properties. Therefore we compared this substance to calcium acetate (CaAC) in a 24-weeks open cross-over trial in 28 maintenance HD patients. Medications and HD prescriptions were kept unchanged during the trial. Following 2 weeks of withdrawal of phosphate binders, patients were randomly assigned to one of the calcium salts for 12 weeks; after a second withdrawal of 2 weeks, all patients were shifted to the other treatment for another 12 weeks. All patients received equimolar doses of CaKE and CaAC with respect to the amount of prescribed elemental calcium. Treatment with CaAC and CaKE significantly reduced s-phosphate levels after 4 weeks (CaAC 1.95+/-0.6 vs. 2.4+/-0.53 mmol/l, P = 0.004; CaKE 1.95+/-0.4 vs. 2.47+/-0.63 mmol/l, P = 0.0001) reaching a virtually stable plateau over the remaining observation time without significant differences between the groups. The incidence of hypercalcaemia defined as a serum calcium level > or =2.8 mmol/l was significantly higher in CaAC than in CaKE treated patients (n = 8 vs. n = 1, P = 0.03). There were no significant differences in serum intact parathyroid hormone (PTH) bicarbonate, albumin or calcitriol levels between the groups after 12 weeks treatment. We conclude that CaKE is as effective as CaAC for treatment of hyperphosphataemia in chronic HD patients and may be particularly helpful in patients who are prone to develop hypercalcaemia.

Adult↗
PubMed1999

[Validating a 7-channel ambulatory polygraphy unit. 1: Operating instructions for the physician and patient].

PURPOSE: For some time, the ambulatory diagnosis of sleep-related breathing disorders has included the use of seven-channel recording units. One such unit is the POLY-MESAM (MAP, Martinsried, FRG). The first part of the present study prospectively investigated the handling of the system for physicians and patients, its technical reliability, reliability of the software used and the results in comparison to handscoring. METHODS: In all, 104 patients (95 males, 9 females) were studied for different severities of obstructive sleep-related breathing disorders. The first 51 patients were connected to the POLY-MESAM in the evening within the clinic. The patients then slept at home and returned the next day. Another 53 patients received only a short briefing in the clinic and connected themselves at home to the POLY-MESAM System. Each patient's status was monitored by means of a visual analogue scale. Automatic evaluation of the data was compared with the results of manual scoring. RESULTS: From the data recorded only 6% of the results were not usable. Patients acceptances of the system were very high (94.3%). On average each patient required 21 minutes for attaching and detaching the device. Scoring and instructing the patients required an average of 23 min. Regarding the apnea-hypopnea index (AHI), the correlation between automatic (AHI = 11.1) and manual (AHI = 11.3) evaluations was high. Analysis of snoring turned out to be insufficient. CONCLUSIONS: The POLY-MESAM proved to be reliable and user-friendly. Our findings show that the system can be recommended for outpatient screening of sleep-related breathing disorders, with patients able to manage the system without help. Validation by using simultaneous polysomnography is the subject of part two of the study.

Adult↗
PubMed1999

[Donation for medical care at the Vienna Civic Hospital in the 15th century. Responsibility for daily rounds].

The medical treatment in the city hospital of Vienna, which was attached to the University as a teaching facility, was not of the best quality in the 15th century. A report by an unknown author describes the medical treatment as tending to lead to death rather than recovery. In 1436 a donation was made by Nicolaus Aichberger de Fürstenfeld, a well known member of the Medical School of Vienna University, to engage a physician who had to visit the patients daily. The acceptance of the donation is not documented, but the research shows Michael Gruber, student of medicine, as possessor of the foundation. The obligation for daily medical treatment was a remarkable requirement for that time.

Austria↗
PubMed1998

Sex-specific usage patterns of sleeping sites in grey mouse lemurs (Microcebus murinus) in northwestern Madagascar.

Sleeping sites are a potentially important resource for grey mouse lemurs since they are confronted with high daily temperature fluctuations and a high predation pressure. In order to determine the existence and degree of resource competition, sleeping site characteristics, locations, and usage patterns as well as sleeping group compositions were investigated in a 3 month field study in a dry deciduous forest of northwestern Madagascar. The daily sleeping sites of females were on average better insulated and safer than those of males. Males used more sleeping sites and changed the site more often than females. During the whole study, males slept alone, whereas the females formed stable sleeping groups in on average 83.7% of the days. Sex-specific differences in usage patterns might be explained by intersexual resource competition and female dominance and could possibly be related to differential parental investment of the sexes. The underlying study indicates that sleeping sites may be a restricted and defendable resource for grey mouse lemurs. The investigation gives new insights into the distribution patterns and social organization of this species.

Animals↗
PubMed1998

Comparison of the genetic diversity of wild and captive groups of Microcebus murinus using the random amplified polymorphic DNA method.

Continued survival of most animal species depends on population management and active protection. It is generally agreed that, in order to avoid extinction of endangered species, ex situ and in situ conservation must be developed in tandem. However, even though many recommendations have been put forward to promote the survival of captive populations, some rapidly become extinct due to loss of genetic diversity (drift effect). Genetic markers, such as random amplified polymorphic DNA (RAPD) markers, can be applied to rapid testing of many individuals. They also permit analysis of very small amounts of DNA, when small species such as mouse lemurs (Microcebus) are to be tested. Using RAPD markers, we compare genetic diversity in four captive groups of Microcebus murinus to that in a sample of 70 wild mouse lemurs. Following the principles of Mendelian inheritance, each amplified fragment of DNA may be considered as a 'locus' (or an amplifying site). The series of bands amplified by a particular primer in any individual is referred to as the individual's 'profile'. We tested 5 primers, or, in the above terms, we studied 98 different 'loci'. Results showed that the captive groups had lost genetic information with respect to the wild sample. Among the four captive groups, the loss of genetic diversity varied according to their number of founders and/or the management of their captive reproduction. Our study of polymorphism permitted us to establish tools for the genetic management of captive breeding, and for the determination of paternity which frequently give better results than behavioural studies; and simulation of introductions or departures of individuals in one very monomorphic group permitted estimation of future increases in its genetic diversity.

Amino Acid Sequence↗
PubMed1998

Acoustically dimorphic advertisement calls separate morphologically and genetically homogenous populations of the grey mouse lemur (Microcebus murinus).

Sexual advertisement calls of male mouse lemurs from two neighbouring demes in a dry deciduous forest of western Madagascar were recorded during the breeding season. Demes were located about 1.5 km apart with no geographic barrier between them. They were characterised morphometrically and genotyped by RAPD fingerprinting. According to univariate and multivariate statistical analysis, demes differed neither in body measurements, nor in the banding patterns produced by RAPD fingerprinting. The acoustic pattern of the advertisement call, however, showed significant differences: Six variables of the frequency and time domain differed between the demes. Discriminant function analysis revealed that one variable, total call duration, was sufficient to classify more than 89% of the calls correctly to the corresponding deme. We postulate that these differences are comparable to dialects in birds, because demes were morphologically and genetically indistinguishable and no barrier prevented genetic exchange between them. Possible explanations for the emergence of dialects in a prosimian species are outlined.

Acoustics↗
PubMed1998

Recent bacterial and viral infection is a risk factor for cerebrovascular ischemia: clinical and biochemical studies.

We performed a case-control study to investigate the role of recent infection as stroke risk factor and to identify pathogenetic pathways linking infection and stroke. We examined 166 consecutive patients with acute cerebrovascular ischemia and 166 patients hospitalized for nonvascular and noninflammatory neurologic diseases. Control subjects were individually matched to patients for sex, age, and season of admission. We assessed special biochemical parameters in subgroups of stroke patients with and without recent infection (n = 21) who were similar with respect to demographic and clinical parameters. Infection within the preceding week was a risk factor for cerebrovascular ischemia in univariate (odds ratio [OR] 3.1; 95% confidence interval (CI), 1.57 to 6.1) and age-adjusted multiple logistic regression analysis (OR 2.9; 95% CI, 1.31 to 6.4). The OR of recent infection and age were inversely related. Both bacterial and viral infection contributed to increased risk. Infection elevated the risk for cardioembolism and tended to increase the risk for arterioarterial embolism. Stroke patients with and without preceding infection were not different with respect to factor VII and factor VIII activity, fibrin monomer, fibrin D-dimer, von Willebrand factor, C4b-binding protein, protein S, anticardiolipin antibodies, interleukin-1 receptor antagonist, soluble tumor necrosis factor-alpha receptor, interleukin-6, interleukin-8, and neopterin. In conclusion, recent infection is an independent risk factor for acute cerebrovascular ischemia. Its role appears to be more important in younger age groups. The pathogenetic linkage between infection and stroke is still insufficiently understood.

Adult↗
PubMed1997

Are the characteristics of betanidin glucosyltransferases from cell-suspension cultures of Dorotheanthus bellidiformis indicative of their phylogenetic relationship with flavonoid glucosyltransferases?

Uridine 5'-diphosphoglucose:betanidin 5-O- and 6-O-glucosyltransferases (5-GT and 6-GT; EC 2.4.1) catalyze the regiospecific formation of betanin (betanidin 5-O-beta-glucoside) and gomphrenin I (betanidin 6-O-beta-glucoside), respectively. Both enzymes were purified to near homogeneity from cell-suspension cultures of Dorotheanthus bellidiformis, the 5-GT by classical chromatographic techniques and the 6-GT by affinity dye-ligand chromatography using UDP-glucose as eluent. Data obtained with highly purified enzymes indicate that 5-GT and 6-GT catalyze the indiscriminate transfer of glucose from UDP-glucose to hydroxyl groups of betanidin, flavonols, anthocyanidins and flavones, but discriminate between individual hydroxyl groups of the respective acceptor compounds. The 5-GT catalyzes the transfer of glucose to the C-4' hydroxyl group of quercetin as its best substrate, and the 6-GT to the C-3 hydroxyl group of cyanidin as its best substrate. Both enzymes also catalyze the formation of the respective 7-O-glucosides, but to a minor extent. Although the enzymes were not isolated to homogeneity, chromatographic, electrophoretic and kinetic properties proved that the respective enzyme activities were based on the presence of single enzymes, i.e. 5-GT and 6-GT. The N terminus of the 6-GT revealed high sequence identity to a proposed UDP-glucose: flavonol 3-O-glucosyltransferase (UF3GT) of Manihot esculenta. In addition to the 5-GT and 6-GT, we isolated a UF3GT from D. bellidiformis cell cultures that preferentially accepted myricetin and quercetin, but was inactive with betanidin. The same result was obtained with a UF3GT from Antirrhinum majus and a flavonol 4'-O-glucosyltransferase from Allium cepa. Based on these results, the main question to be addressed reads: Are the characteristics of the 5-GT and 6-GT indicative of their phylogenetic relationship with flavonoid glucosyltransferases?

Amino Acid Sequence↗
PubMed1997

[Qualifying the contribution of school health service to school achievement].

School as a place of learning and living for children has also recognised the responsibility for children's health. For effectively supporting the schools in health promotion, it will be necessary to assist and expand. Special need of development exists in the health care of school beginners. Therefore, three initial phases in school health care for school beginners are suggested. Recent reform policy in primary schools has been taken into consideration. Especially the dialogue between teachers and school physicians must be promoted. Focus is also on the "Jugendsprechstunde" (youth consulting hours) in secondary schools. Guidelines for youth consulting in school are reported. This part of school health care cannot be successful without considering the interests and needs of school children. To achieve the goals of development School Health Service receive support by the present national "KJGD-Campaign"): In addition small-scale service organisations should assist each other. Questioning of schools may also stimulate further development. Demands made by teachers on school health care development are therefore reported.

Achievement↗
PubMed1996

A nuclear RNA-binding cyclophilin in human T cells.

Cyclophilins (CyPs) are binding proteins for the immunosuppressive drug cyclosporin A (CsA). CyPs are evolutionarily highly conserved proteins present in both pro- and eukaryotes as well as in different subcellular locations. CyPs possess enzymatic activity, namely peptidyl-prolyl cis-trans isomerase (PPIase) activity; CyPs are involved in cellular protein folding and protein interactions. To date, only cyclosporins and proteins are known to interact with CyPs. Here we describe a novel nuclear cyclophilin (hCyP33) from human T cells with an additional RNA-binding domain. This combines for the first time RNA binding and protein folding in one protein.

Amino Acid Isomerases↗
PubMed1996

Experimental and clinical evaluation of laryngeal chondrosynthesis.

The aim of this study was to investigate and develop techniques for stabilization and reconstruction of laryngeal defects with a method similar to osteosynthesis. In an anatomical study, 400 extrusion forces of sutures and various screws (Howmedica) were measured in the thyroid cartilage of fresh cadavers. A new screw was then especially designed for cartilage and a new technique was developed for stabilizing cartilage, using a screw-nut made out of bone. To date, 30 patients have undergone chondrosynthetic reconstruction of the larynx. Measurements of extrusion forces were found to depend on the degree of calcification present in the area of the laryngeal skeleton examined and the type of fixation device used. Good clinical results were achieved in all 30 patients studied and depended on stabilization of the two sides of the thyroid cartilage after thyrotomies, bridging of laryngeal defects and splinting of laryngeal fractures. Besides the increased extrusion forces the advantages of chondrosynthesis lay within the possibilities of axial stabilization and exact bridging of defects with or without implants.

Adolescent↗
PubMed1996

Castration affects the emission of an ultrasonic vocalization in a nocturnal primate, the grey mouse lemur (Microcebus murinus).

Male primates have evolved particular displays to advertise male fitness. In nocturnal prosimians it was assumed that such displays (vocal advertisement, marking behaviour) are hormonally dependent and influenced by olfactory cues of a receptive female. To test this assumption mouse lemur males of different gonadal status (males castrated as adults, normal males), or of varying olfactory input (males vomeronasalectomized or bulbectomized as adults) were paired with intact "stimulus" preoestrous females and vocalization, vocal rates, and marking behaviours were monitored. The vocal rate of only one particular vocalization, the "trill" advertisement call, was sexually dimorphic and changed depending on gonadal status. Vocalization rate declined significantly in sexually experienced, castrated males as did their marking behaviour. There was however no significant correlation between either calling rate or marking behaviour and plasma testosterone levels in gonadally intact males. Neither vomeronasalectomy nor bulbectomy had a significant effect on trill calling rate or marking behaviour. Results imply that testicular hormones have a greater impact on advertisement calling and marking motivation than olfactory information of preoestrous females. In contrast to rodents, ultrasonic calling rate seems to be not only dependent on gonadal status, but also on social experience.

Animals↗
PubMed1996

Long-term treatment with calcium-alpha-ketoglutarate corrects secondary hyperparathyroidism.

Calcium-alpha-ketoglutarate (Ca-ket) is known as a highly effective phosphate (P) binder in hemodialysis (HD) patients. In addition, alpha-ketoglutarate has been shown to improve metabolic alterations. We investigated the effect of long-term P-binding therapy with Ca-ket to determine whether P accumulation is the main reason of secondary hyperparathyroidism (HPT) in HD patients or not. Ca-ket was prescribed to 14 HD patients as a soluble preparation in a mean dosage of 4.5 g/day (0.975 g elemental Ca) for a period of 36 months. Serum P continuously dropped from prestudy 2.6 +/- 0.1 (mean +/- SEM) to 1.9 +/- 0.07 mmol/l (p < 0.001), whereas serum Ca increased from 2.2 +/- 0.1 to 2.47 +/- 0.08 mmol/l (p < 0.05). Thus, Ca/P ratio in serum converted significantly from 0.91 +/- 0.02 (prestudy) to 1.28 +/- 0.01 (p < 0.001). Intact parathyroid hormone (iPTH) continuously normalized in all patients from 29 +/- 5 to 8 +/- 2 pmol/l (p < 0.001). The present data show that long-term treatment with Ca-ket normalizes secondary HPT by simultaneously P binding and correcting Ca/P ratio in serum without vitamin D treatment.

Follow-Up Studies↗