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M Altwegg

Publications and source records attributed to M Altwegg.

At least 127 records · Page 7Linked to original sources
PubMed1986

The nucleotide sequence of two homogeneic Drosophila melanogaster tRNATyr isoacceptors: application of a rapid tRNA anticodon sequencing method using S-1 nuclease.

The nucleotide sequence of the two major Drosophila melanogaster tRNATyr isoacceptors was determined to be pC-C-U-U-C-G-A-U-A-m2G-C-U-C-A-G-D-D-G-G-acp3 U-A-G-A-G-C-m2(2)G-G-psi-G-G-A-C-U-G/Q-psi-A-m1G-A-Um-C-C-A-U-A-G-m7 G-D-C-G-C-U-G-G-U(T)-psi-C-A-m1A-A-U-C-C-G-G-C-U-C-G-A-A-G-G-A-A-C-C-AOH . The two isoacceptors differ by the presence of a G or a Q in the wobble position. Both contain a partial modification in position 54 (U/T). Thus, these tRNAs are transcribed from a single gene (or many genes with identical sequences). A fast and sensitive postlabeling method for sequencing tRNA anticodons is described. Nuclease S-1-treated tRNA is labeled with 5[32P]-pCp using T-4 RNA ligase. The tRNA fragments are then separated on 7 M urea/20% PAA gels. After autoradiography the RNA is eluted and digested with T-2 RNase. The nature of the labeled nucleotides is determined by two-dimensional thin-layer chromatography. The same method can be used to determine the 5' sequence of a tRNA by 3' labeling 5' tRNA halves with 5[32P]-pCp and subsequent chemical sequencing.

Animals↗
PubMed1985

Evaluation of a rapid, reliable, and inexpensive screening test for the serological diagnosis of human brucellosis.

In many laboratories the serological diagnosis of brucellosis is based on a tube agglutination test requiring incubation for two days and therefore causing delay in reporting of results. A slide agglutination test using an acidified, rose Bengal colored antigen that can be read after only 4 min was evaluated for its usefulness as a screening test for the presence of agglutinins in human sera. In sera of patients with culturally proven brucellosis or serological evidence for active infection the sensitivity of the slide agglutination test was 100%. Of 97 tube agglutination-negative sera none was positive in the slide test. From these results it was concluded that sera can be tested by the slide agglutination test which is quicker, easier to perform, and less expensive than the tube agglutination test. If positive, it is followed by a tube agglutination test which gives quantitative information and is necessary to follow the course of an infection.

Agglutination Tests↗
PubMed1985

Growth of Aeromonas spp. on cefsulodin-Irgasan-novobiocin agar selective for Yersinia enterocolitica.

Twenty-eight strains of Aeromonas spp. were analyzed for their ability to grow on two different kinds of cefsulodin-Irgasan (triclosan; Ciba-Geigy AG, Basel, Switzerland)-novobiocin (CIN) agar containing 15 or 4 mg of cefsulodin per ml and on inositol-bile salts-brilliant green (IBB) agar. Relative to blood agar, 68% of the strains were inhibited by more than 2 logs (i.e., less than 1% growth) at 37 degrees C (39% at 25 degrees C) on CIN I (high cefsulodin concentration), 7% were inhibited at either temperature on CIN II (low cefsulodin concentration), 4% were inhibited on IBB agar at 37 degrees C, and none were inhibited on IBB agar at 25 degrees C. These results reflect the MICs of cefsulodin on CIN Base: the MIC for 50% of the strains was 8 mg/liter at 37 and 25 degrees C, and the MICs for 90% of the strains were 16 mg/liter at 37 degrees C and 64 mg/liter at 25 degrees C. The MICs of Irgasan and novobiocin were far beyond the concentrations used in CIN media. We argue that CIN agar containing 4 mg of cefsulodin per ml (CIN II) can be used for the simultaneous detection of Aeromonas spp. and Yersinia spp.

Aeromonas↗
PubMed1983

The genes coding for 4 snRNAs of Drosophila melanogaster: localization and determination of gene numbers.

Four small nuclear RNAs (snRNAs) have been isolated from Drosophila melanogaster flies. They have been characterized by base analysis, fingerprinting, and injection into Axolotl oocytes. The size of the molecules and the modified base composition suggest that the following correlations can be made: snRNA1 approximately U2-snRNA; snRNA2 approximately U3-snRNA; snRNA3 approximately U4-snRNA; snRNA4 approximately U6-snRNA. The snRNAs injected into Axolotl oocytes move into the nuclei, where they are protected from degradation. The genes coding for these snRNAs have been localized by "in situ" hybridization of 125-I-snRNAs to salivary gland chromosomes. Most of the snRNAs hybridize to different regions of the genome: snRNA1 to the cytological regions 39B and 40AB; snRNA2 to 22A, 82E, and 95C; snRNA3 to 14B, 23D, 34A, 35EF, 39B, and 63A; snRNA4 to 96A. The estimated gene numbers (Southern-blot analysis) are: snRNA1:3; snRNA2:7; snRNA3:7; snRNA4:1-3. The gene numbers correspond to the number of sites labeled on the polytene salivary gland chromosomes.

Ambystoma↗
PubMed1983

Performance of two four-hour identification systems with atypical strains of Enterobacteriaceae.

Two four-hour systems (Rapid 20E and Micro-ID) for identification of Enterobacteriaceae were evaluated using 66 strains isolated from clinical specimens which could not be identified by conventional methods. API 20E was used as reference method. Both systems had an acceptable identification rate (84.8% for Rapid 20E and 74.2% for Micro-ID). After referral to API's computer facilities the identification rate of Rapid 20E rose to 92.4%. Micro-ID incorrectly identified 16.7% of the strains and Rapid 20E only 1.5%. On the other hand, no identification was achieved in 13.6% of the strains using Rapid 20E versus 6% using Micro-ID. On the basis of these findings Rapid 20E is considered the more suitable system for the rapid identification of Enterobacteriaceae strains which cannot be identified by conventional methods.

Bacteriological Techniques↗
PubMed1980

The nucleotide sequence of histidine tRNA gamma of Drosophila melanogaster.

The nucleotide sequence of D. melanogaster histidine tRNA gamma was determined to be: pG-G-C-C-G-U-G-A-U-C-G-U-C-psi-A-G-D-G-G-D-D-A-G-G-A-C-C-C-C-A-C-G-psi-U-G-U-G- m1G-C-C-G-U-G-G-U-A-A-C-C-m5C-A-G-G-U-psi-C-G-m1A-A-U-C-C-U-G-G-U-C-A-C-G-G-m5C -A-C-C-AOH. An additional unpaired G is found at the 5' end, and the T in the TpsiC loop is replaced by a U.

Animals↗
PubMed1980

The nucleotide sequence of glutamate tRNA4 of Drosophila melanogaster.

The nucleotide sequence of Drosophila melanogaster glutamate tRNA4 was determined to be: pU-C-C-C-A-U-A-U-G-G-U-C-psi-A-G-D-G-G-C-D-A-G-G-A-U-A-U-C-U-G-G-C (m) -U-U-U-C-A-C-C-A-G-A-A-G-G-C-C-C-G-G-G-T-psi-U-C-G-A-U-U-C-C-C-G-G-U-A-U-G-G-G-A-A-C-C-AOH. A partial modified C is found at position 32 in the anticodon loop.

Animals↗
PubMed1979

The nucleotide sequence of phenylalanine tRNA2 of Drosophila melanogaster: four isoacceptors with one basic sequence.

The nucleotide sequence of Drosophila melanogaster phenylalanine tRNA2 was determined to be: pG-C-C-G-A-A-A-U-A-M2G-C-U-C-A-G-D-D-G-G-G-A-G-A-G-C-m22G-psi-psi-A-G-A-C(m)-U-Gm-A-A-mlG-A-psi-C-U-A-A-A-G-m7G-U(D)-C-C-C-C-G-G-T-psi-C-A-mlA-U-C-C-G-G-G-U-U-U-C-G-G-C-A-C-C-AOH. Upon RPC-5 chromatography at pH 3.8 tRNA2Phe can be separated into four isoacceptors due to the partial modifications in positions 32 and 47. Thus the posttranscriptional modification of tRNA2Phe transcribed from one gene (or many genes with identical sequences results in four isoacceptors with the same basic sequence.

Animals↗
PubMedDate not supplied

Aeromonas caviae: an enteric pathogen?

Of the Aeromonas spp. isolated routinely in our laboratory from human feces, about two thirds represent Aeromonas caviae. In contrast to Aeromonas hydrophila and Aeromonas sobria, this species has been considered to be of little enteropathogenic significance due to the absence of known virulence factors. The clinical data presented here suggest a clinical significance of A. caviae, at least in some cases. As yet nothing is known about the pathogenic mechanisms involved.

Adolescent↗
PubMedDate not supplied

Retroperitoneal abscess and bacteremia due to Mycoplasma hominis in a polytraumatized man.

We report a case of a retroperitoneal abscess due to Mycoplasma hominis in a young polytraumatized man who developed septicemia under treatment with rifampin and flucloxacillin. M. hominis was recovered from blood cultures as well as from the abscess near the left iliac spine. After 10 days of therapy with clindamycin the patient improved, and intraoperatively taken swabs were culture negative but still positive by PCR.

Abdominal Abscess↗
PubMedDate not supplied

Tropheryma whippelii DNA in saliva of patients without Whipple's disease.

Tropheryma whippelii is the causative agent of Whipple's disease, a difficult to diagnose systemic illness. Amplification of part of its 16S ribosomal RNA gene(s) has become a standard diagnostic method because of increased sensitivity as compared to classical histopathological analysis. Recently, we demonstrated the presence of T. whippelii DNA by PCR in duodenal biopsies and/or gastric juice of a considerable fraction of individuals without clinical signs of Whipple's disease. In this follow-up study, saliva and dental plaques of the same patients were screened for the presence of T. whippelii DNA. Six out of the 14 previously PCR-positive persons but none of the 17 controls had T. whippelii DNA in their saliva. Our results suggest that Whipple bacteria are ubiquitous environmental or commensal organisms causing Whipple's disease only in a particular subset of individuals, possibly those with an as yet uncharacterized immunological defect.

Actinobacteria↗
PubMedDate not supplied

Bacterial molecular epidemiology based on a nonradioactive probe complementary to ribosomal RNA.

The use of plasmid pKK3535 (a pBR322-derived plasmid containing a ribosomal RNA operon) is described for determining rRNA gene restriction patterns. The plasmid allowed the use of both radioactive as well as nonradioactive procedures and provided features that are necessary for the inclusion of internal and/or external standards that facilitate comparison of strains. The patterns generated are identical to those obtained by hybridization with 32P-labelled rRNA.

Bacteria↗
PubMedDate not supplied

rRNA gene restriction patterns and plasmid analysis as a tool for typing Salmonella enteritidis.

We have evaluated the usefulness of ribosomal RNA gene restriction patterns and of plasmid analysis for the typing of Salmonella serotype enteritidis isolates. Strains were isolated from single patients excreting the organism for up to about 4 months, as well as from clusters of patients who had probably been exposed to the same source of infection. The sensitivity of ribosomal DNA (rDNA) analysis was dependent on the restriction enzyme used; of 14 different enzymes, only SmaI and SphI showed different rDNA patterns. Differences were detected between clusters, but all strains belonging to a given cluster showed identical rDNA patterns. In one single strain (isolated at day 66), we observed an SphI pattern that was not identical to that of the original isolate from the same patient. Strains were also typed by plasmid analysis. All strains harboured a plasmid of approximately 55 kb with identical restriction patterns. Smaller plasmids of 4.5 and 4.3 kb were isolated from all the strains belonging to one and two clusters, respectively. We have demonstrated that the analysis of rRNA genes is a sensitive and useful method for epidemiological typing of Salmonella serotype enteritidis, which can be complemented by analysis of plasmids if such structures are present.

Chromatography, Gel↗