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W Fischer

Publications and source records attributed to W Fischer.

At least 19 recordsLinked to original sources
PubMed1992

The structure of pneumococcal lipoteichoic acid. Improved preparation, chemical and mass spectrometric studies.

Pneumococcal lipoteichoic acid was extracted and purified by a novel, quick and effective procedure. Structural analysis included methylation, periodate oxidation, Smith degradation, oxidation with CrO3, and fast-atom-bombardment mass spectrometry. Hydrolysis with 48% (by mass) HF and subsequent phase partition yielded the lipid anchor (I), the dephosphorylated repeating unit of the chain (II) and a cleavage product of the latter (III). The proposed structures are: (I) Glc(beta 1----3)AATGal(beta 1----3)Glc(alpha 1----3)acyl2Gro, (II) Glc(beta 1----3)AATGal(alpha 1----4)GalNAc(alpha 1----3)GalNAc(beta 1----1)ribitol and (III) Glc(beta 1----3)AATGal(alpha 1----4)GalNAc(alpha 1----3)GalNAc, where AATGal is 2-acetamido-4-amino-2,4,6-trideoxygalactose, and all sugars are in the pyranose form and belong to the D-series. Alkaline phosphodiester cleavage of lipoteichoic acid, followed by treatment with phosphomonoesterase, resulted in the formation of II and IV, with IV as the prevailing species: [sequence: see text] The linkage between the repeating units was established as phosphodiester bond between ribitol 5-phosphate and position 6 of the glucosyl residue of adjacent units. The chain was shown to be linked to the lipid anchor by a phosphodiester between its ribitol 5-phosphate terminus and position 6 of the non-reducing glucosyl terminus of I. The lipoteichoic acid is polydisperse: the chain length may vary between 2 and 8 repeating units and variations were also observed for the fatty acid composition of the diacylglycerol moiety. Preliminary results suggest that repeating units II and IV are enriched in separate molecular species. All species were associated with Forssman antigenicity, albeit to a various extent when related to the non-phosphocholine phosphorus. Owing to its unique structure, the described macroamphiphile may be classified as atypical lipoteichoic acid.

Carbohydrate Sequence↗
PubMed1992

[The medical record at the center of medical informatics].

Several areas in medical institutions, particularly the technical and administrative ones have been governed by computers for a long time. The proper medical work field (diagnosis, treatment, follow-up, correspondence and billing) however has hitherto mostly been ignored by data processing. We describe an electronic medical record introduced 4 years ago. All aspects of medical practise and all the specialists involved in patient care are integrated in the electronic document. In the center is a medical base of knowledge adaptable to all specialties as well as an expert system for direct control of the data entered by all concerned persons.

Ambulatory Surgical Procedures↗
PubMed1992

Anticonvulsant and sodium channel blocking effects of ralitoline in different screening models.

Ralitoline, a thiazolidinone derivative chemically distinct from known antiepileptic drugs, possesses remarkable anticonvulsant properties as demonstrated in various animal models of epilepsy. The efficacy of this compound seems to be comparable or even better than that of conventional antiepileptics. In the present study, the activity of ralitoline was investigated in four seizure models in rodents in order to characterize the anticonvulsant profile of action further. In the maximal electroshock seizure test (mice), this compound showed marked anticonvulsant effects (ED50 2.8 mg/kg i.p.). The efficacy of clinically established anti-epileptics was significantly increased when ralitoline was given as co-medication. In the strychnine seizure test (mice), ralitoline (5 and 10 mg/kg) prolonged the latency of tonic seizures as well as the survival time. On the other hand, in the subcutaneous pentylenetetrazol seizure threshold test (mice), this drug revealed limited protective actions at higher doses and increased the effectiveness of ethosuximide. In unrestrained rats with chronically implanted electrodes, ralitoline (5 mg/kg) significantly reduced the duration of electrically-evoked hippocampal discharges and raised the focal stimulation threshold (10 mg/kg). In the rotorod ataxia test (mice), a TD50 value of 14.5 mg/kg i.p. was determined for ralitoline (protective index TD50/MES-ED50 5.2). With regard to the possible mode of action, whole-cell voltage-clamp experiments on cultured neonatal rat cardiomyocytes showed that ralitoline may act specifically on voltage-sensitive sodium channels. The compound inhibited the fast sodium inward current in a frequency- and voltage-dependent manner. In conclusion, the findings confirm the potent anticonvulsant effects of ralitoline, especially against generalized tonic-clonic and complex partial seizures. Moreover, in combination with antiepileptics, an additive synergism can be found at lower concentrations. Regarding the mode of action, this drug was capable of depressing the fast sodium inward current in cultured heart ventricular cells, suggesting that the local anesthetic properties may be important for the anticonvulsant activity of ralitoline.

Animals↗
PubMed1992

[Malunion of the distal radius and its treatment. Apropos of 122 radii].

We have reviewed 109 out of 122 operations performed for malunion of the distal radius. An excellent or good result was achieved in 80%, with 3% poor and 7% mediocre. Complications occurred in 12.6%. Accurate assessment of the frontal and sagittal angles of the articular surface of the distal radius was necessary in planning the operation, and correct realignment was required to achieve a proper result. Some cases in which an excellent correction was achieved did not produce a satisfactory outcome because of residual problems with soft tissue or ligaments. No patient with carpal instability had a good result. The morphology of the fracture and the sex or activity level of the patient did not influence the result.

Adolescent↗
PubMed1992

Heterogeneity of lipoteichoic acid detected by anion exchange chromatography.

A complex polydispersity became apparent when the poly(glycerophosphate) lipoteichoic acid of Enterococcus faecalis was chromatographed on DEAE-Sephadex. The chain length varied between 13 and 33 glycerophosphate residues per lipid anchor. In parallel, the extent of chain glycosylation increased from 0.2 to 0.4 diglucosyl residues per glycerophosphate unit. Substitution with D-alanine ester showed a reverse distribution dropping with increasing chain length from 0.53 to 0.23 mol D-alanine per mol phosphorus. Variations in the fatty acid composition were also observed. The results extent and modify the current picture of lipoteichoic acid biosynthesis. They further suggest that during infection the mammalian organism may be confronted particularly with long-chain less hydrophobic molecular species.

Carbohydrate Sequence↗
PubMed1992

Urinary metabolites of amitriptylinoxide and amitriptyline in single-dose experiments and during continuous therapy.

In a cross-over design, six healthy volunteers received 50 mg amitriptylinoxide (AT-NO) IV and orally and 50 mg amitriptyline (AT) IV. Urine was collected completely for 8 h and occasionally up to 48 h. In addition, five patients each under treatment with AT-NO or AT for tension headache collected 24-h urine samples. The following compounds were analysed by HPLC: AT-NO, E- and Z-10-hydroxy-AT-NO (E- and Z-10-OH-AT-NO), free and conjugated AT, E- and Z-10-OH-AT and their mono- and didemethylated analogues, and 2-OH-nortriptyline (2-OH-NT). Unchanged AT-NO in urine accounted for an average of 34% and 22% of the single IV and oral doses, respectively, and for 28% in continuous therapy, with a further 8-9% being excreted as E- and Z-10-OH-AT-NO. The remaining part was converted to the same metabolites as was AT. In the steady state the measured compounds accounted for 74% and 77% of the daily AT-NO and AT doses, respectively. The renal plasma clearance of AT-NO varied between 75 and 265 ml/min in the six volunteers. Tubular secretion must play an important part in the renal excretion of AT-NO.

Adult↗
PubMed1992

Hydrophobic interaction chromatography fractionates lipoteichoic acid according to the size of the hydrophilic chain: a comparative study with anion-exchange and affinity chromatography for suitability in species analysis.

Hydrophobic interaction chromatography fractionated the lipoteichoic acid of Enterococcus faecalis into species of decreasing poly(glycerophosphate) chain length and decreasing extent of substitution with alpha-kojibiosyl residues (Glcp alpha 1----2Glcp alpha 1----). The chain length varied between 14 and 33 glycerophosphate residues per lipid anchor, the extent of glycosylation between 0.18 and 0.44 mol of alpha-kojibiosyl residues per mole of phosphorus, and, accordingly, the number of alpha-kojibiosyl substituents per chain between 3 and 15. Almost identical values were obtained when the same lipoteichoic acid was chromatographed on DEAE-Sephadex and concanavalin A, which separate molecular species according to increasing number of phosphate groups and alpha-kojibiosyl residues, respectively. Species from all three columns, which were identical in chain length and glycosylation, also had similar fatty acid patterns. These results prove the suitability of all three procedures for species analysis. One advantage of hydrophobic interaction chromatography over the other two procedures lies in its broader applicability since it is not dependent on negative charges or specifically binding oligosaccharide structures. Another advantage is the capacity of hydrophobic interaction chromatography to separate molecular species differing in the number of fatty acids [W. Fischer, H.U. Koch, and R. Haas (1983) Eur. J. Biochem. 133, 523-530] and render them accessible to molecular analyses.

Chromatography, Affinity↗
PubMed1992

Alzheimer's disease: is the decrease of the cholinergic innervation of the hippocampus related to intrinsic hippocampal pathology?

Consistent findings in the hippocampi of patients with Alzheimer's disease are the presence of neurofibrillary tangles in pyramidal neurons and the loss of choline acetyltransferase activity due to degeneration of hippocampal cholinergic terminals. The present study sought to clarify, in the brains of five patients with Alzheimer's disease and four controls, whether the loss of cholinergic terminals in the hippocampal stratum pyramidale in Alzheimer's disease is related to degenerative changes in hippocampal pyramidal cells. A polyclonal antibody to human choline acetyltransferase was employed to visualize immunohistochemically cholinergic terminals. Hippocampal neurons were stained with Cresyl Violet, neurofibrillary tangles with thioflavin S and a monoclonal antibody against phosphorylated neurofilament (RT97). Quantification of the stained structures was performed in CA4, CA1 and the subiculum, on five sections selected from the entire anteroposterior extent of each hippocampus. In the group of Alzheimer patients, the densities of cholinergic terminals were homogeneously diminished in the three hippocampal subregions in comparison with the controls (32-33%). In contrast, a significant loss of pyramidal neurons was found only in CA1, and the density of neurofibrillary tangles was markedly increased only in CA1 and the subiculum in Alzheimer's disease. These findings suggest that there is no relationship between the loss of cholinergic terminals and the degeneration of pyramidal cells in the hippocampus of patients with Alzheimer's disease.

Aged↗
PubMed1992

Plating of fresh clavicular fractures: results of 122 operations.

A total of 131 fractures of the clavicle were operated on in 129 patients. There was no bony infection or infected pseudarthrosis. Four clavicles refractured after removal of the plate and five operations led to pseudarthroses which were successfully treated by reoperation. Radiological and clinical results in the majority of the re-examined patients were excellent. Indications, operative technique and causes of poor results are described.

Adolescent↗
PubMed1992

1H-nuclear magnetic resonance (NMR) studies on the inclusion complex of prostaglandin E1 (PGE1) with alpha-cyclodextrin.

Prostaglandin E1 is currently marketed as a freeze-dried injectable inclusion complex with alpha-cyclodextrin for the treatment of peripheral arterial diseases. alpha-Cyclodextrin is used as a stabilizing agent and to improve the dissolution characteristics of prostaglandin E1. Upon dilution with the infusion medium, the inclusion complex dissociates almost completely as shown by NMR chemical shift measurements of the complexed and uncomplexed prostaglandin E1. Nuclear Overhauser effect (NOE) measurements of the interacting atoms of alpha-cyclodextrin and prostaglandin E1 provide insight into the structure of the complex.

Alprostadil↗
PubMed1992

Macrophage response to bacteria: induction of marked secretory and cellular activities by lipoteichoic acids.

Lipoteichoic acids (LTAs) from various bacterial species, including Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Enterococcus faecalis, and Listeria monocytogenes, were examined for the ability to induce secretory and cellular responses in a pure population of bone marrow-derived mononuclear phagocytes. Some of the highly purified LTAs, in particular LTAs from Bacillus subtilis, S. pyogenes, E. faecalis, and Enterococcus hirae, were able to affect each of the macrophage parameters measured, i.e., reductive capacity, secretion of tumor necrosis factor and nitrite, and tumoricidal activity. As after stimulation with whole organisms or other bacterial products, secretion of tumor necrosis factor induced by these LTAs reached its maximum within the first few hours of the interaction, while secretion of nitrite and tumoricidal activity required 24 to 36 h for full expression. Other purified LTAs, i.e., LTAs from Streptococcus sanguis, S. pneumoniae, and L. monocytogenes, as well as lipomannan from Micrococcus luteus affected only some of these parameters, while native LTA from S. aureus was inactive. There was no obvious correlation between biological activity and chain length, kind of glycosyl substituents, glycolipid structures, or fatty acid composition of LTAs. Deacylation of LTAs resulted in a complete loss of activity, and deacylated LTAs did not impair the activity of their acylated counterparts, suggesting that acyl chains may be essential for binding of LTA to the cell surface. The results demonstrate that some LTA species are potent inducers of macrophage secretory and cellular activities.

Animals↗
PubMed1992

[Plasma- and tissue concentrations following intramuscular administration of etofenamat. Pharmacokinetics of etofenamat and flufenamic acid in plasma, synovium, and tissues of patients with chronic polyarthritis after administration of an oily solution of etofenamat].

Studies on Plasma and Tissue Concentrations of Etofenamate following Intramuscular Application/Pharmacokinetics of etofenamate and flutenamic acid in plasma, synovia and tissues of patients with chronic polyarthritis after application of oily etofenamat solution Pharmacokinetics of etofenamate (ETO, CAS 30544-47-9; Rheumon i.m.) and flufenamic acid (FLU, CAS 530-78-9) were investigated in plasma, synovial fluid, and tissues after single intramuscular application of etofenamate to patients with rheumatoid arthritis. 62 patients with indicated operative procedure in the knee-joint received a single dose of etofenamate dissolved in oil before operation. At definite times between 1.5 and 48 h post injectionem samples from 6 patients of each time group were collected. Samples of plasma, synovial fluid, synovial membrane, muscle, bone, hyaline cartilage, and fat tissue and in some cases meniscus cartilage were taken. Concentrations of ETO and its active metabolite, FLU, were determined by HPTLC. In all tissues investigated, concentration/time courses of ETO and FLU were observed. ETO and FLU were measured first in all matrices 1.5 h at the latest 3 h post injectionem. Pharmacokinetics in tissues follows that in plasma. Rate-limiting step is the liberation of drug from the oil depot. For a long period pharmacokinetics of ETO and FLU is mainly determined by the constant liberation from the oil depot (zero order kinetics of liberation). Zero order kinetics is deduced from the linear ascent of the cumulated AUC (in percent) vs. time plot. It is directly related to the liberation of drug from the galenical formulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Continuity and discontinuity of psychopathology: a study of patients examined as children and as adults. I. Antecedents of adult schizophrenic disorders].

The demographical stability of the Canton of Geneva made it possible for us to do a prospective study of all the children who had consulted the Child Psychiatry Service between 1963 and 1967 and who later consulted the public adult psychiatry services. On the basis of the adult diagnoses, wo looked for specific clinical "clusters" in childhood which would allow us to differentiate statistically the groups of children. We present here the results of the group of children who developed schizophrenia in adulthood. We found a specific childhood "cluster" which clearly distinguishes these children from the others. It includes: serious relational disorders, neurodevelopmental impairment, attention deficit and school learning disorders.

Adolescent↗
PubMed1992

Problems in performing a double-blind multicenter study using a hypnotic in private practice.

1. The procedure described--the immediate data transfer and entry system (ITES)--is suitable to improve the quality of data collected in multicentre studies in private practice. 2. The results of the study show that regarding influence on sleep quality and daytime well-being the non-benzodiazepine Z is significantly superior to placebo and slightly superior to the benzodiazepines F and T. 3. The advantage of Z treatment is the better daytime well-being after taking the hypnotic for sleep induction the night before. 4. This study shows that a quality standard equal to that in clinical practice may be achieved in private practice.

Adolescent↗
PubMed1992

[The question of oral sedation using midazolam in outpatient dental surgery].

The aim of the present study was to evaluate the effect of one tablet of midazolam (Dormicum 7.5 mg) used as a premedicant for minor oral surgery and to assess the potential risk of hypoventilation. In all of the patients no significant drop in arterial oxygen saturation could be observed, but on the other hand, no real anxiolytic or amnestic effects either. With the little therapeutic use observed with the given premedication, a more widespread application of the substance in this dosage cannot be recommended, particularly when taking into account the possibility of complications and the loss of the patients's fitness to drive for the next twelve hours.

Anesthesia, Dental↗
PubMed1992

[Histomorphology of pelvic floor muscles in women with urinary incontinence].

Success of urinary incontinence surgery so far depended primarily on the intensity and quality of preoperative diagnosis, the resulting choice of techniques, suture material, and the surgeon's skills. The role played by tissue available from the patient herself, however, had not been adequately considered, although such an assessment would have been of major relevance to all methods using autogenic tissue. Preliminary histological-histochemical and morphometric investigations of pubococcygeal muscles of ten patients revealed unambiguous right-left differences with regard to muscle quality and fibre typing, mean cross-section area of muscle fibres, and connective tissue response up to degeneration and also concerning replacement of striated muscles by smooth muscles. Further studies into collagen metabolism are likely to enable more reliable prognosis of operations for urinary incontinence.

Adult↗
PubMed1992

[Treatment of stress incontinence].

This is an introducing survey at the symposium "New techniques in gynaecology and obstetrics" held 25th and 26th of October, 1990, in Rostock. Surgery of urinary incontinence is not sufficient despite improving choice of methods. Therefore each new solution is welcome. In our times suprapubic colposuspension operations are the most interesting ones. Using fibrin sealing could be advantageous, if it would be possible, to limit sealing area and following tissue consolidation to the pubourethral ligaments. Sealing of fascial sutures and avoiding of vaginal adhesions in cases of vaginal repair would be imaginable. As alternative mobile vaginal suspension by means of fascial strips is demonstrated.

Adult↗