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Biomedical subjects

B Suter

Publications and source records attributed to B Suter.

49 records · Page 3Linked to original sources
PubMed1994

[Does acupuncture modify skin circulation via the autonomic nervous system?].

It has been postulated and there are indications that acupuncture affects the cardiovascular system via the autonomic nervous system. The blood vessels of the hand skin have sympathetic constrictor nerves only. Therefore, the possible effect of acupuncture on the ANS can be investigated by measurements of microvascular perfusion and thermoregulation of the hands. Knowing the physiological effects of acupuncture may help to improve acceptance of this unconventional medical approach.

Acupuncture Therapy↗
PubMed1991

Requirement for phosphorylation and localization of the Bicaudal-D protein in Drosophila oocyte differentiation.

In the Drosophila female the product of the germline stem cell, the cystoblast, gives rise to 16 interconnected cystocytes. One of them differentiates into the oocyte, while the 15 others become polyploid nurse cells. Bic-D is required for the differentiation of an oocyte and hence for fertility. Recessive mutations in Bic-D block the oocyte-specific accumulation of its own and other RNAs. Based on its properties and distribution, the Bic-D protein appears to be a component of a cytoskeletal transport or anchoring system. Additional results suggest that the phosphorylation of the Bic-D protein is essential for its accumulation in the pro-oocyte and that this process leads to the gradual localization to the pro-oocyte of factors required for oocyte differentiation.

Alleles↗
PubMed1989

Bicaudal-D, a Drosophila gene involved in developmental asymmetry: localized transcript accumulation in ovaries and sequence similarity to myosin heavy chain tail domains.

The Bicaudal-D (Bic-D) gene is essential for the differentiation of the oocyte in Drosophila. Dominant gain-of-function mutations result in the formation of double abdomen embryos. The Bic-D gene was cloned and identified using restriction fragment length polymorphisms, Northern analysis, and transformation rescue. Bic-D RNA accumulates in the oocyte during the earliest stages of oogenesis and is localized anteriorly in later stages. The predicted protein contains several extended amphipathic helices, and its similarity to myosin heavy chain tails, paramyosin, and kinesin suggests a similar type of coiled-coil protein interaction.

Amino Acid Sequence↗
PubMed1988

Identification of an amber nonsense mutation in the rosy516 gene by germline transformation of an amber suppressor tRNA gene.

Seven xanthine dehydrogenase and cross-reacting material negative Drosophila melanogaster rosy stocks were screened for amber and ochre nonsense mutations. Amber and ochre nonsense suppressors were created by site-directed mutagenesis starting from a wild-type tRNA(Tyr) gene. The suppressor tRNA genes were subcloned into a pUChsneo transformation vector providing heat-shock controlled neomycin resistance. The seven rosy stocks were germline transformed with amber and ochre tDNA(Tyr), and the G1 generation was screened for Geneticin resistance. Surviving rosy516 flies transformed with the amber suppressor showed an eye colour intermediate between the original ry516 stock and the wild-type, suggesting that ry516 is an amber nonsense mutant. This was confirmed by sequencing the relevant part of the ry516 gene; the analysis revealed a C-to-T transition in a CAG glutamine codon at nucleotide 1522 of the wild-type rosy gene.

Animals↗
PubMed1988

tRNA(Tyr) genes of Drosophila melanogaster: expression of single-copy genes studied by S1 mapping.

Six Drosophila melanogaster tRNA(Tyr) genes have been isolated and sequenced. They contained introns of different sequences and two size classes: 20 or 21 base pairs (bp) (five genes) and 113 bp (one gene). However, the sequences coding for the mature tRNA(Tyr) were identical in all six genes. The 113-bp intron-containing gene was a single-copy gene. Hence, its primary transcript could be traced by S1 mapping. The gene was turned on during embryogenesis and continually expressed to various degrees during the following developmental stages. Thus, S1 mapping is a feasible method to follow the transcriptional activity of individual genes with identical mature products, provided that their primary transcripts are unique. The six genes were organized in two clusters of three and two genes, respectively (each containing a 20- or a 21-bp intron; cytological localization, 85A), and a single-copy gene (113-bp intron; cytological localization, 28C). We show that four of the six tRNA(Tyr) genes characterized were localized in putative 5' control regions of developmentally controlled genes transcribed by polymerase II.

Animals↗
PubMed1988

Pseudouridine modification in the tRNA(Tyr) anticodon is dependent on the presence, but independent of the size and sequence, of the intron in eucaryotic tRNA(Tyr) genes.

In Saccharomyces cerevisiae, pseudouridine formation in the middle position of the tRNA(Tyr) anticodon (psi 35) is dependent on the presence of the intron in the tRNA(Tyr) gene (Johnson and Abelson, Nature 302:681-687, 1983). Drosophila melanogaster tRNA(Tyr) genes contain introns of three size classes: 20 or 21 base pairs (bp) (six genes), 48 bp (one gene), and 113 bp (one gene). As in yeast, removal of the intron led to loss of psi 35 in the anticodon when transcription was assayed in Xenopus laevis oocytes. All Drosophila intron sizes supported psi 35 formation. The same results were obtained with the homologous X. laevis tRNA(Tyr) genes containing introns of 12 or 13 bp or with a deleted intron. The introns of yeast (Nishikura and DeRobertis, J. Mol. Biol. 145:405-420, 1981), D. melanogaster, and X. laevis tRNA(Tyr) wild-type genes, while they all supported psi 35 synthesis, did not share any consensus sequences. As discussed, these results, taken together, suggest that for appropriate function the psi 35 enzyme in the X. laevis oocyte needs the presence of an unqualified intron in the tRNA gene and a tRNA(Tyr)-like structure in the unprocessed tRNA precursor.

Animals↗
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

Queuosine modification of the wobble base in tRNAHis influences 'in vivo' decoding properties.

The 'in vivo' decoding properties of four tRNAHis isoacceptors, two from Drosophila melanogaster and two from brewer's yeast, were studied after their microinjection, along with turnip yellow mosaic virus (TYMV) coat protein mRNA, into Xenopus laevis oocytes. The two Drosophila isoacceptors are identical besides containing either a guanosine (G) or the hypermodified nucleoside queuosine (Q) in the wobble position. The brewer's yeast isoacceptors differ by four bases in the anticodon stem, and by one base in the amino acceptor stem. Our results show that, under competing 'in vivo' conditions, the Drosophila tRNAHis with the anticodon GUG clearly prefers the histidine codon CAC to the codon CAU, whereas little preference is observed for the tRNAHis with the anticodon QUG for the codon CAU, and no preference for either codon by the two yeast isoacceptors. Hence, it can be concluded that the presence of the Q-base clearly affects the choice of the codon. This is the first demonstration of an 'in vivo' codon preference by tRNA isoacceptors differing in the modification of the wobble base during the elongation step of protein synthesis. These results imply that one function of the Q-base is at the translational level.

Animals↗
PubMed1982

[Is the aorto-coronary bypass operation useful in patients with advanced coronary sclerosis and poor ventricular function?].

The prognosis and long term results in 56 patients with coronary artery disease and impaired left ventricular function (EF less than or equal to 40%) who underwent aortocoronary bypass surgery (all cases) and aneurysmectomy (26 cases) between 1972 and 1980 were compared with those in 47 equally ill patients treated medically. Survival was significantly higher in the surgical than in the non-surgical group, the survival rate being 80% and 58% respectively at 41 months after study entry (p = 0.012). No difference in survival was observed between grafted patients and patients in whom additional aneurysmectomy was performed. 26 patients were recatheterized postoperatively and this revealed an increase in left ventricular ejection fraction at rest from 33 +/- 5% to 44 +/- 11% (p less than 0.001) and a decrease in left ventricular end-diastolic pressure from 18 +/- 8 mm Hg to 14 +/- 8 mm Hg (p less than 0.025). Postoperatively the patients had less angina and physical working capacity increased. At restudy the average NYHA class had decreased in the surgical group from 2.9 +/- 0.7 to 2.1 +/- 0.9 (p less than 0.001) but was unchanged in the non-surgical group (2.6 +/- 0.6 and 2.6 +/- 0.7 respectively). It is concluded that aortocoronary bypass surgery improves survival, left ventricular function and symptoms in patients with coronary artery disease and severely impaired myocardial function.

Adult↗
PubMed1980

Effects of age, sex, and income level on sex-role differentiation in preschoolers.

Sex-role differentiation in 337 three-, four-, and five-year-old girls and boys, approximately equally divided into lower- and middle-income groups, was measured by five sex-role tests. A composite z score was also used for increased reliability. The study was replicated in order to investigate the reliability of the measures. The results showed that sex and, to a partial degree, age, had significant effects, but income level had little effect on sex-role differentiation. A factor analysis of the sex-role tests is also discussed.

Age Factors↗
PubMed1975

Masculinity-femininity in creative college women.

The possible relationship between masculinity and creativity in college women was investigated through a battery of masculinity-femininity scales that tapped both manifest and latent masculinity, factorially derived clusters, and an ipsative measure. Two samples (n = 45 each) of women who had scored above the 75th percentile and below the 25th percentile respectively on two measures of creativity were used. High creative subjects scored higher on activity and described themselves as more masculine; indications are that they possess a broader, less stereotyped sex-role identity.

Adolescent↗