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Biomedical subjects

W Haupt

Publications and source records attributed to W Haupt.

At least 55 records · Page 3Linked to original sources
PubMed1986

[Experimental studies on the course and consequences of infection with Graphidium strigosum (Nematoda, Trichostrongylidae) in Oryctolagus cuniculus (domestic rabbit)].

After oral infection of domesticated rabbits with 1,500 Graphidium strigosum-larvae III third-stage larvae were discovered in the stomach during the next 6 d, fourth-stage larvae from the 8th d and mature nematodes from the 34th d onwards. In 26 rabbits infected with 75...2,000 larvae III the prepatent period of Graphidium strigosum-infestation varied from 40 to 60, in most cases from 40 to 50 d. After one oral infection with 500...1,000 Graphidium strigosum-larvae III 3-month old domesticated rabbits showed no clinical symptoms, their performance was impaired but only insignificant and a population of 154 to 765 mature nematodes parasitizing in the stomach caused a gastritis catarrhalis chronica, partly a fibrosing gastritis.

Animals↗
PubMed1985

[Autologous replantation of spleen particles--an established procedure? An opinion].

Autologous splenic replantation after splenectomy for trauma is generally recommended in order to prevent postsplenectomy sepsis. Several aspects, however, make this method uncertain: The extent of splenosis induced is not to be predicted. Even if the whole spleen is replanted, the resulting mass may not exceed splenosis, which sometimes develops spontaneously after sole splenectomy. But patients with extended splenic regenerates do not differ from those without any splenosis, considering various immunologic parameters. Postoperative complications after splenic replantation (abscess, intestinal occlusion) are possible, although they may be rare. Fatal cases of postsplenectomy sepsis despite massive splenosis are known. The most important reasons apparently are the altered vascularity and scarring in splenic regenerates. There is no specific test for immunological splenic function. Therefore there is no test to judge the success of replantation, too. Overall, the preservation of the spleen and the vaccination of splenectomized individuals are the most important surgical intentions.

Bacterial Infections↗
PubMed1984

The influence of sequences adjacent to the recognition site on the cleavage of oligodeoxynucleotides by the EcoRI endonuclease.

We have investigated the influence of the nucleotide sequence adjacent to the recognition site on the rate of cleavage of DNA by the restriction endonuclease EcoRI. For this purpose two decadeoxynucleotides, d(G-G-G-A-A-T-T-C-T-T) (Ia) and d(A-A-G-A-A-T-T-C-C-C) (Ib) were synthesized. The duplex Ia X Ib is cleaved by EcoRI preferentially in the dA-rich strand (approximately 10 times over the dG-rich strand). The individual nucleotides Ia and Ib are also cleaved by EcoRI, Ib at a higher rate than Ia and both at a lower rate than Ia X Ib. The temperature dependence of the reaction rate shows that only double-stranded oligodeoxynucleotides are substrates for the EcoRI endonuclease. We have, furthermore, synthesized oligomers of d(G-G-A-A-T-T-C-C), which contain two, three and four EcoRI sites, respectively. These oligodeoxynucleotides are preferentially cleaved at the sites next to the 5' end, where the recognition site is only flanked by one dG X dC base pair, in contrast to the other sites which are flanked by three such pairs. These data indicate that sequences adjacent to the recognition site influence the rate of cleavage: dA X dT base pairs enhance and dG X dC base pairs slow down the hydrolytic activity of the EcoRI endonuclease.

Base Composition↗
PubMed1984

[Endoparasite infestation of the stomach and intestinal tract of feral rabbits from the Leipzig region].

Investigations on the infestation with endoparasites in stomach and gut of feral rabbits from the region of Leipzig. During the hunting periods in the years 1976 till 1979 the viscera of 122 wild rabbits shot in two different biotopes in the area of Leipzig were examined for endoparasites. 63.11% harboured Ctenotaenia ctenoides and Cittotaenia denticulata and 8.19% Cysticercus pisiformis. Graphidium strigosum was demonstrated in 36.88%, Trichostrongylus retortaeformis in 82.78%, Passalurus ambiguus in 13.11% and Trichuris leporis in 7.13% of the rabbits. 71.13% of the rabbits shed oocysts of six different species of intestinal coccidia in their faeces and Eimeria stiedai--infections were diagnosed in the livers of 1.63% of the rabbits. Regional differences were demonstrated in the frequency of Graphidium strigosum-, Passalurus ambiguus- and tapeworm infestations of the wild rabbits examined.

Animal Population Groups↗
PubMed1983

The perception of light direction and orientation responses in chloroplasts.

We may summarise what is known, in stationary cells, about perception of light direction. Cells have evolved three different mechanisms to transform light direction into an absorption gradient: light attenuation, light refraction, and dichroic orientation of the photoreceptors. Furthermore, these mechanisms can be combined and can cooperate in the same cell. With the photochromic pigment phytochrome, a regular change in dichroism upon photoconversion is an important improvement for effectively establishing an absorption gradient. However, perception of the direction of light, while a necessary condition, is not solely sufficient for a directional response. Equally important is a strongly localised transduction chain effecting localised control of the intracellular motor apparatus. Slowly-diffusing ions seem to fulfil this requirement, but further work needs to be done to elucidate the mechanisms completely.

Chlorophyta↗
PubMed1981

The effect of several nucleic acid binding drugs on the cleavage of d(GGAATTCC) and pBR 322 by the Eco RI restriction endonuclease.

The endonucleolytic action of the EcoRI restriction enzyme on the double-stranded oligonucleotide d(GGAATTCC) and the supercoiled plasmid DNA pBR 233 is inhibited by actinomycin D, ethidium bromide, proflavin, distamycin A and netropsin. Half-maximal inhibition is observed at around 100 microM concentrations for the intercalating drugs, and around 0.1 to 1 microM concentrations for netropsin and distamycin A. The inhibitory activity of these drugs can be correlated with their affinity to the oligonucleotide and the plasmid DNA. Since at high concentrations of the drugs a complete inhibition is observed, it is concluded that the effect of the drugs on the stereochemistry of the EcoRI site is such that recognition is excluded.

Circular Dichroism↗
PubMed1977

[Value of radiographic studies on the cervix uteri and internal uterine orifice with reference to irregular pregnancies (abortus--premature labor)].

The research concerning a decrease of premature births in the context of the efforts to reduce infant mortality resources an improvement of our knowledge about the causes of preterm delivery. This publication bases on more than 1000 hysterosalpingographies in order to prove the assumed causality between cervical insufficiency, cervix dilation, and the angle between the cervix and the corpus uteri, and uterushypoplasia. The influence of these facts dependent on menstrual rhythm and related to parity, especially the habitual form, is stated by numerical data. Concerning a retrospective analysis of abortions and premature births the x-ray photography of the uterus makes important statements possible and renders a specific and substantiate prophylactic therapy during the following pregnancies feasible.

Abortion, Habitual↗
PubMed1975

[Course of the parasite phase of development of Trichostrongylus axei (Cobbold, 1879) Railliet et Henry, 1909, in the domestic rabbit].

Rabbits of the New Zealand White and Small Chinchilla breeds were each infected at 3-4 months of age with 4-10 thousand invasive trichostrongyle larvae. Prepatent period of the infection was 22-32 days. Third-stage larvae were present up to the 6th day of infection, fourth-stage from the 8th day, fifth-stage from the 14th day and sexually mature trichostrongyles on the 18th day. The period of patency of the infection lasted for over a year, but only small numbers of eggs were passed in faeces, and food intake was not affected. Between 14 and 44% of the third-stage larvae developed into sexually mature nematodes, regardless of infection dose or duration of infection.

Animals↗
PubMed1975

[Course of Trichostrongylus retortaeformis (Zeder, 1800) Looss, 1905, infestation in the domestic rabbit (Oryctolagus cuniculus)].

Fifty Havanna, Small Chinchilla and crossbred rabbits were each infected at 3 to 4 months of age with a single dose of 5-20 thousand third-stage larvae of the trichostrongyle. After infection with 10 thousand larvae, third-stage larvae were present on the 1st and 2nd days, fourth-stage on the 4th-6th days, fifth-stage on the 7th and 8th days and sexually mature trichostrongyles on the 8th-10th days. Only a small proportion of third-stage and fourth-stage larvae failed to develop into sexually mature neamtodes. Prepatent period of infection was 9-10 days; patency lasted from a few weeks to 2-3 months. Single infection with 5000-7000 invasive larvae produced no clinical signs. A dose of 10 thousand larvae produced diarrhoea even during the prepatent period, and this was accompanied by expulsion of a considerable part of the parasite population. Infection with 20 thousand larvae produced a loss of weight in the experimental rabbits.

Animals↗