PubMed Health⌕ Search

Biomedical subjects

W Prinz

Publications and source records attributed to W Prinz.

At least 37 records · Page 2Linked to original sources
PubMed1995

Synchronizing actions with events: the role of sensory information.

Tasks requiring the subject to tap in synchrony to a regular sequence of stimulus events (e.g., clicks) usually elicit a response pattern in which the tap precedes the click by about 30-50 msec. This "negative asynchrony" was examined, first, by instructing subjects to use different effectors for tapping (hand vs. foot; Experiments 1 and 2), and second, by administering extrinsic auditory feedback in addition to the intrinsic tactile/kinesthetic feedback (Experiment 2). Experiment 3 controlled whether the results observed in Experiment 2 were due to purely sensory factors within the auditory modality. Results suggest that taps are synchronized with clicks at the central level by superimposing two sensory codes in time: the tactile/kinesthetic code that represents the tap (the afferent movement code) and the auditory code that represents the click (the afferent code that results from the guiding signal). Because the processing times involved in code generation are different for these two central codes, the tap has to lead over the click.

Adult↗
PubMed1993

Mutation of monofunctional 6-phosphofructo-2-kinase in yeast to bifunctional 6-phosphofructo-2-kinase/fructose 2,6-bisphosphatase.

We have shown previously that 6-phosphofructo-2-kinase in yeast has negligible fructose-2,6-bisphosphatase activity even though resembling in part of its C-terminal sequence the phosphatase domain of the bifunctional liver enzyme. Here we show that exchanging Ser-404 to His-404 in the yeast peptide creates a bifunctional enzyme with a fructose-2,6-bisphosphatase activity involving a phosphoprotein intermediate. Like mammalian bifunctional enzymes, the His-404 mutant protein is readily phosphorylated by fructose 2,6-P2 with a half-saturation of 0.4 microM, the same Km value as for its fructose-2,6-bisphosphatase activity. Protein phosphorylation by the C-subunit of cAMP-dependent protein kinase, presumably at a C-terminal consensus site, increases the Km value to 1.5 microM. The newly created fructose-2,6-bisphosphatase is inhibited competitively by its product fructose 6-P with a K(i) of 0.6 mM. No effect of the His-404 mutation was found on 6-phosphofructo-2-kinase activity, in line with the mutant yeast enzyme having independent kinase and phosphatase domains, like its mammalian wild-type counterparts. The results would fit with the evolution of the PFK26 gene having involved fusion between kinase and phosphatase genes--as proposed for the mammalian enzyme--but with accompanying or later silencing of the fructose-2,6-bisphosphatase activity.

Animals↗
PubMed1988

Comparison of the gastric antisecretory and antiulcer potencies of telenzepine, pirenzepine, ranitidine and cimetidine in the rat.

In different rat models, the antisecretory and antiulcer effects of the M1-antimuscarinics telenzepine and pirenzepine, the nonselective antimuscarinic atropine, and the H2-blockers ranitidine and cimetidine were compared to each other. Intravenous telenzepine proved to be more potent in inhibiting gastric acid secretion in the Ghosh-Schild rat (carbachol-stimulated), the chronic fistula rat (basal secretion), or, both intravenously and orally, in the modified Shay rat, as compared to pirenzepine, cimetidine or ranitidine. After intravenous administration, only atropine was equally potent to telenzepine in all three models, but it was less potent than telenzepine after oral administration in the modified Shay rat. Gastric mucosal lesions induced by pylorus ligation plus acetylsalicyclic acid or acetylsalicyclic acid plus HCl were best inhibited by telenzepine and atropine, with pirenzepine, ranitidine and cimetidine being less potent, their relative potencies depending on the particular experimental model used. Thus, among the antiulcer drugs tested, telenzepine was the most potent one with respect to both antisecretory and antiulcer activity. Moreover, the duration of the antiulcer effect of telenzepine proved to be significantly longer than that of pirenzepine in the modified Shay rat.

Animals↗
PubMed1984

[The course of labor following cesarean section with special reference to peridural anesthesia].

In a retrospective study the mode of delivery by 565 pregnant women who had previously undergone Caesarean section, was explored on the basis of their medical records. Particular attention was paid to the problem of PDA. Primary Caesarean section was performed in about 25% of the cases and secondary Caesarean section 22%. 57% of the women who had previously delivered via Caesarean section, now delivered vaginally. 71,4% of these patients had peridural anaesthesia during labour. In 17 cases laparotomy following vaginal delivery was necessary because of suspected rupture of the uterus due to rupture of the uterine scar. In 10 cases this diagnosis was confirmed. The authors come to the conclusion that previous Caesarean section is no indication for a repeat Caesarean section. Under exactly controlled conditions the authors were able to clarify that PDA can be safely applied in patients with previous Caesarean section.

Anesthesia, Epidural↗
PubMed1983

[Morphologic findings in the placenta in intrauterine fetal growth retardation].

The placentas of 105 small-for-dates infants and 190 newborns of normal birth weight were investigated morphologically. Each of these two groups consists of premature newborns and mature newborns. Macroscopic and microscopic data were evaluated by means of a so called data bank. --The weight and the area of attachment were determined. The histologic findings were classified in two groups: 1. Disturbances of placental maturation, 2. Morphologic changes in consequence of reduced uteroplacental blood flow. A marked increase of hypoplastic placentas was found among immature and mature small-for-dates infants. Retarded placental maturity was found more frequently among mature small-for-dates infants then among prematures. Among these, placentas with signs of a reduced uteroplacental perfusion were found more frequently. --It is assumed that the pathogenetic course is different in placentas of premature and mature small-for-dates infants.

Female↗
PubMed1982

[The placental polyp, a cause of late puerperal hemorrhage (author's transl)].

9.062 deliveries took place from 1975 to 1979 at the Department of Obstetrics and Gynecology, University of Ulm. In 33 patients (0,36%) a curettage had to be performed because of late puerperal hemorrhage. Clinically mostly a placental polyp was suspected. In 10 cases (0,11%) histologic examination revealed trophoblastic tissue, in 17 cases (0,19%) decidua only and in 6 cases (0,066%) endometrium of different stages of proliferation. No correlation could be found between the mode of delivery or the placental stage and the occurrence of late puerperal hemorrhages. Also no correlation could be demonstrated between the bleedings and the number of earlier pregnancies, former curettings or uterine surgery for malformations. Comparison with earlier reports in the literature shows that the rate of late puerperal hemorrhages can be diminished by an active procedure during the placental stage. It must be pointed out that in all cases in which placental tissue can not be demonstrated histologically the term "placental polyp" should be avoided and be replaced by the term "decidual polyp".

Decidua↗
PubMed1981

[Cytologic studies after insertion of intrauterine contraceptive devices (IUD) (author's transl)].

Cervical smears of 554 women using IUDs were examined. The following criteria were evaluated: 1. Age distribution, 2. maturation index of the vaginal epithelium, 3. vaginal flora, 4. cytologic criteria of inflammation, 5. period of time between insertion of the IUD and the cytological examination, 6. final cytologic diagnosis. 554 women without IUD and normal gynaecological status served as a control group. It was the goal of the study to find out, firstly if IUDs in situ produce typical and specific changes in the cytologic pattern and secondly if the rate of suspicious and positive findings is increased: In IUD using women the rate of cases with unphysiologic vaginal flora is increased, the rate of inflammatory cytologic specimen is also higher than in the control group. The rate of inflammatory smears decreases with the increasing interval of time between insertion and cytological examination. IUD typical changes could be observed only in so far as in this group the cytologic signs of chronic cervicitis were increased. Inflammatory alterations are the reason for the higher rate of "suspicious" smears in the group of IUD-users. There was no higher rate of praecancerous lesions among the IUD users. The importance of these results for the clinical management are pointed out.

Adult↗
PubMed1980

A systematic study of the effect of vitamin C supplementation on the humoral immune response in ascorbate-dependent mammals. I. The antibody response to sheep red blood cells (a T-dependent antigen) in guinea pigs.

We have investigated the humoral immune response to Sheep Red Blood Cells (S.R.B.C.--a T-dependent cellular antigen) in two groups of random-bred guinea pigs. A control group of animals was maintained on "minimal" ascorbate intake, while the test group animals received supplementary vitamin C in their drinking water. Serum haemolytic antibody levels were monitored at various intervals subsequent to immunization with S.R.B.C. The primary antibody response of the ascorbate-supplemented animals differed statistically significantly from that of the controls in two respects. The peak antibody titre was both higher and occurred earlier in the test animals. No significant difference in the antibody response to a secondary injection of antigen was manifest. Our observations suggest that vitamin C stimulates the elaboration of Ig M-type antibodies in particular.

Animals↗
PubMed1980

[Variations of placental enzymes in hypoxia (author's transl)].

Tissue of normal-term placentas, after normal pregnancy and spontaneous delivery, was incubated under normoxic and hypoxic conditions. Placental tissue samples were taken under sterile conditions, immediately after delivery, and incubated six hours in a medium to which six per cent or 26 per cent oxygen were supplied. After incubation, the tissue was homogenised, and the following enzymes were determined in the supernatant: aldolase, lactate-dehydrogenase, alkaline phosphatase, acid phosphatase, and glucose-6-dehydrogenase. - The activities of aldolase, glucose-6-dehydrogenase, and acid phosphatase increased and those of lactate-dehydrogenase and acid phosphatase decreased under conditions of oxygen deficit. Such changes in enzyme activity seem to suggest that in hypoxia anaerobic glycolysis is likely to increase, while maternal-foetal exchange drops, all accompanied by beginning compensatory proliferation of the trophoblast.

Acid Phosphatase↗