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U Müller

Publications and source records attributed to U Müller.

At least 253 records · Page 14Linked to original sources
PubMed1995

PKA activity in the antennal lobe of honeybees is regulated by chemosensory stimulation in vivo.

The involvement of cyclic nucleotide cascades has been suggested for chemosensory signal processing as well as synaptic plasticity. Cyclic AMP-dependent protein kinase (PKA) is a major mediator for transient changes in these second messengers. The objective of this study was to examine the role of PKA in the central processing of chemosensory information by the honeybee. Effects of chemosensory stimulation in vivo were detected in the first chemosensory neuropil of the honeybee brain, the antennal lobe (AL), by using a combination of shock freezing and specific determination of PKA activity. Mechanosensory or odor stimulation of the antennae had no effect on PKA activity. Brief application of aqueous solutions (pure water or sucrose solution) to an antenna caused a rapid and transient elevation of PKA activity in the ipsilateral AL. A series of such stimuli led to a graded increase in PKA activity followed by a rapid decrease during the first 10 s after the end of stimulation, but elevated levels of PKA activity were observed for as long as 1 min. These results suggest that PKA activity and its regulation contribute to central processing of chemosensory signals.

Animals↗
PubMed1995

Inhibitors of lipid peroxidation protect cultured neurons against cyanide-induced injury.

We tested the 21-aminosteroid U-74500A and the 2-methylaminochroman U-83836E, two potent inhibitors of lipid peroxidation, for their protective efficacy against cyanide- or Fe2+/Fe(3+)-induced damage of cultured neurons from chick embryo telencephalon. U-74500A (0.1-10 microM) as well as U-83836E (0.01-10 microM) reduced cyanide-induced neurotoxicity, indicating that lipid peroxidation plays an important role in the genesis of cyanide-induced neuronal injury. Both U-74500A and U-83836E, but not the NMDA antagonist dizocilpine (1 microM, prevented Fe2+/Fe(3+)-induced neuronal degeneration.

Animals↗
PubMed1995

[Frequency of antibiotics-associated colitis in hospitalized patients in 1974-1991 in "Comprehensive Hospital Drug Monitoring", Bern/St. Gallen].

In 3 divisions of internal medicine of teaching hospitals of the Comprehensive Hospital Drug Monitoring (CHDM) Foundation Bern/St Gallen, 42,920 patients consecutively admitted between 1974-1991 were investigated for adverse drug reactions. Of these 16,150 patients (38%) had received at least one systemically administered antibacterial drug during the hospital stay. Antibiotic-associated colitis included the following diagnoses: pseudomembranous colitis, hemorrhagic colitis and milder forms of colitis. We collected the data of these patients by searching for all diagnoses which might represent antibiotic-associated colitis (from the list of WHO adverse drug reaction terminology). 9 individual patients with one episode of probable antibiotic-associated colitis were found. In 5 of these cases, only one drug given during the hospital stay seemed to be implicated. An additional 32 patients were admitted with antibiotic-associated colitis in relation to treatment with the same groups of drugs before hospital admission. Based on the exposure pattern of the 9 patients with antibiotic-associated colitis compared to all patients exposed during hospital stay, we estimated the following frequencies related to the drug groups with at least 1,000 patients exposed: for all antibacterial chemotherapeutics 0.6/1000 (0.25-1.06); all penicillins 0.6/1000 (0.22-1.32), for benzyl-, phenoxy-, ureido-, isoxazolyl penicillins and methicillin 2.0/1000 (0.42-5.92) and aminopenicillin or analogues, with or without clavulanic acid 0.6/1000 (0.18-1.35). For cephalosporins the frequency is 1.4/1000 (0.17-5.12). Under sulfonamides combined with trimethoprim or related substances (5077 exposed patients) and fluoroquinolones (1043 exposed patients) no case was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

[Brain and gallbladder metastases 10 years after local excision of a cutaneous malignant melanoma].

A 52-year-old man had a generalized seizure resulting in fracture of two vertebrae 10 years after excision of a superficially spreading melanoma (Clark level III) on the left flank. Additional to pain on pressure over the right upper abdomen, the erythrocyte sedimentation rate was increased (41 mm) and the activity of the liver enzymes was raised. Neurological examination indicated a loss of short-term memory, signs of meningeal irritation, unsteady gait and falling tendency. Cerebrospinal fluid showed mild pleocytosis and cells suspicious of tumour. Upper abdominal ultrasonography revealed an enlarged gallbladder with contents of soft-tissue density. Magnetic resonance imaging showed numerous round lesions in the brain which looked nodular after contrast-medium injection. Cholecystectomy revealed metastases of a malignant melanoma. It was likely that the cerebral lesions also represented metastases. The confusional state increased in severity. Neither cytostatic drugs nor radiotherapy were administered, because of the poor prognosis. The patient, now fully disoriented, died 54 days after hospital admission.

Brain Neoplasms↗
PubMed1995

Apolipoprotein E genotype in patients with Alzheimer's disease: implications for the risk of dementia among relatives.

Numerous studies have shown that the risk of Alzheimer's disease (AD) is associated with the dose of the epsilon 4 allele of apolipoprotein E (ApoE). However, more than one third of AD patients lack epsilon 4 and many persons having epsilon 4 survive cognitively intact to old age. We evaluated the lifetime risk of disease in 3,999 first-degree relatives of 549 probands who met the criteria for probable or definite AD and whose ApoE genotypes were known. ApoE genotypes for relatives were not determined. After age 65 the risk among relatives was proportional, as much as 7 to 10% at age 85, to the number of epsilon 4 alleles present in the proband. Risks to relatives of ApoE 2/2 and 2/3 probands were nearly identical at all ages to risks for relatives of ApoE 3/3 probands. The expected proportion of relatives having at least one epsilon 4 allele was calculated for each genotype group based on the distribution of parents, sibs, and offspring in the sample. Among relatives in the ApoE 3/3 group, the lifetime risk for AD by age 90 was three times greater than the expected proportion of epsilon 4 carriers, suggesting that factors other than ApoE contribute to AD susceptibility. Furthermore, the 44% risk of AD by age 93 among relatives of ApoE 4/4 probands indicates that as many as 50% of people having at least one epsilon 4 allele do not develop AD. We also found that among male relatives, risk of AD in the ApoE 3/4 group was similar to that for the ApoE 3/3 group but significantly less than the risk for the ApoE 4/4 group. In contrast, among female relatives the risk for the ApoE 3/4 group was nearly twice that for the ApoE 3/3 group and identical to the risk for the ApoE 4/4 group. These findings are consistent with a sex-modification effect of the E4 isoform on disease susceptibility.

Age of Onset↗
PubMed1995

Octopamine mediates rapid stimulation of protein kinase A in the antennal lobe of honeybees.

In the honeybee octopamine mediates mechanisms of arousal that interfere with the appetitive proboscis extension response to food-indicating chemosensory stimuli. This study demonstrates that injections of octopamine or cyclic adenosine monophosphate (cAMP) into the primary chemosensory neuropil of the honeybee, the antennal lobe, evokes a rapid and transient activation of cAMP-dependent protein kinase (PKA). Other monoamines detectable in the antennal lobe, dopamine and serotonin, do not affect the level of PKA activity. Stimulation of the bees' antenna with the appetitive stimulus water or sucrose solution in vivo also causes a short-term activation of PKA in the antennal lobe. The increased PKA activity can be detected immediately (0.5 s) after stimulation but reverts to the basal level within 3 s. This effect can be abolished by monoamine depletion with reserpine. Since octopamine is the only monoamine that stimulates PKA, it appears to mediate the PKA activation after sucrose stimulus and may contribute to the processing of this chemosensory input.

Animals↗
PubMed1995

Predisposition for cysteine substitutions in the immunoglobulin-like chain of FGFR2 in Crouzon syndrome.

Four cases of Crouzon syndrome, one familial and three sporadic, were investigated for mutations in exon B of the fibroblast growth factor receptor 2 (FGFR2) gene. In the familial case, a mutation was found at codon 340 that exchanged tyrosine for histidine. Mutations at codon 342, detected in the three sporadic cases, replaced a cysteine by another amino acid. While three of the mutations have been described before, the fourth mutation, a C-->G transversion at codon 342 in one of the sporadic cases, has not been recognized previously. Compilation of all exon B mutations in Crouzon syndrome described to date revealed that 6 of the 8 sporadic and 2 of the 9 familial cases have mutations in codon 342. These mutations caused the substitution of cysteine for another amino acid. Given that a mutation in codon 342 was found in 8 out of 17 cases and that in 9 cases the mutation occurred at five additional positions, codon 342 of exon B of the FGFR2 gene may be predisposed to mutations in Crouzon syndrome.

Base Sequence↗
PubMed1995

Identification and characterization of the Arabidopsis thaliana chloroplast DNA region containing the genes psbA, trnH and rps19'.

A 1887-nucleotide chloroplast-DNA region from Arabidopsis thaliana was analyzed. It contains the conserved genes psbA for the precursor of the D1 reaction-centre protein of photosystem II, trnH for tRNAHis, and rps19' for the 6.8-kDa protein of the small ribosomal subunit. Northern hybridization and RNase protection experiments suggest co-transcription of a minor RNA fraction over the full lengths of psbA and the preceding trnK-UUU gene, but not including downstream trnH sequences. In front of the mapped 5' end of the major 1.2-kb psbA transcript is a DNA region that shows the typical architecture of a psbA promoter, consisting of the prokaryotic-type '-35' and '-10' elements as well as the eukaryotic-type 'TATA' motif. The common 3' end of psbA transcripts seems to be located immediately after a stem-loop structure downstream from the coding region.

Arabidopsis↗
PubMed1995

A twelve-month comparative clinical investigation of two low-dose oral contraceptives containing 20 micrograms ethinylestradiol/75 micrograms gestodene and 20 micrograms ethinylestradiol/150 micrograms desogestrel, with respect to efficacy, cycle control and tolerance.

The aim of this study was to compare contraceptive reliability, cycle control and tolerance of an oral contraceptive containing 20 micrograms ethinylestradiol and 75 micrograms gestodene, with a reference preparation containing the same dose of estrogen combined with 150 micrograms desogestrel. This article presents interim data from centers in France and Austria, involving a total of 479 women and 4,991 cycles. Contraceptive reliability was good with both preparations. Two pregnancies occurred in the gestodene group, but neither were due to method failure. In the desogestrel group there were also two pregnancies, of which one was due to method failure. With respect to cycle control, there is a trend towards a lower incidence of intermenstrual bleeding in the gestodene group. The incidence of spotting (scanty bleeding) during the important first three cycles was 3.5% lower in the gestodene group, and over the first six cycles, it was 7.6% lower. Amenorrhea was similar in both groups, but the incidence of dysmenorrhea was significantly lower in the gestodene group (p=0.001). Adverse events were similar in both groups, with headache, breast tension and nausea the most frequently reported symptoms. Body weight remained relatively constant during treatment in both groups, and no hypertension was reported for any woman during the course of the study. In each treatment group, 19 women discontinued because of adverse events. It is concluded that both preparation are reliable and well tolerated oral contraceptives are reliable and well tolerated oral contraceptives; however, there is a more favourable effect on dysmenorrhea by the gestodene formulation.

Adolescent↗
PubMed1995

Spinocerebellar ataxia, type 3 (SCA3) is genetically identical to Machado-Joseph disease (MJD).

Spinocerebellar ataxia, type 3 (SCA3) and Machado-Joseph disease (MJD) are two clinically distinct representatives of the heterogeneous group of autosomal dominant cerebellar ataxias. Assignment of the disease genes to the same region of the long arm of chromosome 14 in both SCA3 and MJD suggested that these two disorders are genetically identical. The recent identification of a trinucleotide (CAG) repeat expansion in a gene underlying MJD facilitates assessment of this hypothesis. We analysed the MJD gene in members of a family with characteristic features of SCA3 and no symptoms typical of MJD. We found the same trinucleotide repeat expansion within the gene that was previously described in patients with MJD. The findings demonstrate that SCA3 and MJD are genetically identical in spite of their pronounced clinical differences. Furthermore, we demonstrate a striking variation in the copy number of the CAG repeat among affected members of the same family.

Chromosome Mapping↗
PubMed1995

Molecular genetics of neuronal adhesion.

Cell-cell and cell-matrix interactions are believed to play crucial roles in neural development. Cell adhesion molecules of the immunoglobulin and cadherin families, as well as integrin heterodimers and extracellular matrix glycoproteins, are widely expressed in the nervous system. The advent of gene targeting technology has heralded a new era for study of their function. Initial observations in 'knockout' mice have yielded some surprising results.

Animals↗
PubMed1995

Prolonged pretreatment with alpha-lipoic acid protects cultured neurons against hypoxic, glutamate-, or iron-induced injury.

The antioxidant dihydrolipoic acid has been shown to reduce hypoxic and excitotoxic neuronal damage in vitro. In the present study, we tested whether pretreatment with alpha-lipoic acid, which presumably allows endogenous formation of dihydrolipoic acid, can protect cultured neurons against injury caused by cyanide, glutamate, or iron ions, using the trypan blue exclusion method to determine neuronal damage. One hour of preincubation with dihydrolipoic acid (1 microM), but not with alpha-lipoic acid, reduced damage of neurons from chick embryo telencephalon caused by 1 mM sodium cyanide or iron ions. alpha-Lipoic acid (1 microM) reduced cyanide-induced neuronal damage when added 24 h before hypoxia, and pretreatment with alpha-lipoic acid for > 24 h enhanced this neuroprotective effect. Both the R- and the S-enantiomer of alpha-lipoic acid exerted a similar neuroprotective effect. Pretreatment with alpha-lipoic acid (1 microM) from the day of plating onward prevented the degeneration of chick embryo telencephalic neurons that had been exposed to Fe2+/Fe3+. alpha-Lipoic acid (1 microM) added to the culture medium the day of plating also reduced neuronal injury induced by 1 mM L-glutamate in rat hippocampal cultures, whereas 30 min of preincubation with alpha-lipoic acid failed to attenuate glutamate-induced neuronal damage. Our results indicate that neuroprotection by prolonged pretreatment with alpha-lipoic acid is probably due to the radical scavenger properties of endogenously formed dihydrolipoic acid.

Animals↗
PubMed1995

The thrombosed popliteal aneurysm with distal arterial occlusion--successful therapy by interdisciplinary management.

Aneurysms of the popliteal artery are rare. Their rate of incidence is reported from 0.1% up to 2.8%. Whereas surgical treatment in an asymptomatic stage bears no problems, the symptomatic stage in a high percentage of patients leads to extremity loss due to thrombosis or embolism. In these cases, amputation rates are reported from 16 to 69%. In the period 1981 - 1994 we saw 39 patients suffering from 58 popliteal aneurysms: 53.4% of these aneurysms were symptomatic. 24.1% of the popliteal aneurysms angiographically showed an occlusion of the popliteal and peripheral outflow tract with concomitant critical limb ischemia. By applying a preoperative local catheter fibrinolysis the outflow tract could be reopened in 13 ischemic extremities and a receiving segment could be recanalized for reconstruction. Following this procedure, in spite of the high number symptomatic cases we gained very good postoperative results in 70.7% of the treated extremities after a maximum follow-up time of 62 months. An aneurysm is commonly seen as a contraindication for the application of lytic therapy. But in the presence of critical extremity ischemia due to a thrombosed or embolizing popliteal aneurysm, preoperative catheter fibrinolysis can often help to save the extremity.

Adult↗
PubMed1995

Integrin alpha 8 beta 1 promotes attachment, cell spreading, and neurite outgrowth on fibronectin.

The integrin alpha 8 subunit, isolated by low stringency hybridization, is a novel integrin subunit that associates with beta 1. To identify ligands, we have prepared a function-blocking antiserum to the extracellular domain of alpha 8, and we have established by transfection K562 cell lines that stably express alpha 8 beta 1 heterodimers on the cell surface. We demonstrate here by cell adhesion and neurite outgrowth assays that alpha 8 beta 1 is a fibronectin receptor. Studies on fibronectin fragments using RGD peptides as inhibitors show that alpha 8 beta 1 binds to the RGD site of fibronectin. In contrast to the endogenous alpha 5 beta 1 fibronectin receptor in K562 cells, alpha 8 beta 1 not only promotes cell attachment but also extensive cell spreading, suggesting functional differences between the two receptors. In chick embryo fibroblasts, alpha 8 beta 1 is localized to focal adhesions. We conclude that alpha 8 beta 1 is a receptor for fibronectin and can promote attachment, cell spreading, and neurite outgrowth on fibronectin.

Amino Acid Sequence↗
PubMed1995

Anti-IgE autoantibodies and bee-sting allergy.

Serum anti-IgE autoantibodies (aaIgE) were investigated by dot immunobinding assay in bee-allergic patients in comparison with nonallergic beekeepers, healthy blood donors, and atopic subjects. Elevated serum levels of aaIgE--either free or combined with IgE--were found in both bee-allergic patients and atopic subjects as compared with beekeepers and healthy donors. With regard to a possible significance of aaIgE for the protective mechanism induced by specific allergen immunotherapy, we estimated aaIgE in bee-allergic patients before, during, and after bee-venom immunotherapy (BVIT) in relation to the outcome of a provocation test with a living bee (PT). During the first year of BVIT, there was no significant change in either free or combined aaIgE, but aaIgE decreased during protracted BVIT over 3-7 years. By using two monoclonal anti-IgE antibodies with different epitope specificity (Le27 and BSW17), we were able to detect two kinds of IgE/aaIgE immune complexes. Our data show that during and after BVIT the levels of one kind of IgE-aaIgE immune complex (the non-BSW17 type) tended to decrease in PT-negative patients but stayed elevated in PT-positive patients. The levels of the other kind of immune complex (the non-Le27 type) were similar in treatment failures and successfully treated patients. These data suggest that there are various kinds of aaIgE with different in vivo functions related to their epitope specificity. Some of them (non-BSW17 type) might be associated with BVIT failure.

Adult↗