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Biomedical subjects

R Gothe

Publications and source records attributed to R Gothe.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effect of temperature and humidity on longevity of unfed adults and on oviposition of engorged females of Dermacentor reticulatus (Ixodidae).

The effect of ambient temperature and relative humidity on longevity of unfed adult ticks and on oviposition of engorged female ticks of Dermacentor reticulatus was examined. The 50% mortality time of unfed adult ticks, incubated at 5 degrees C, 10 degrees C, 20 degrees C and 27 degrees C and humidities of 15%, 50% and 100%, increased irrespective of their sex with rising relative humidity and decreasing temperature. It was longest at 5 degrees C and 100% r.h. being 617.8 days and shortest at 27 degrees C and 15% r.h. amounting only to 33.6 days. All unfed ticks survived an incubation of 150 days at -10 degrees C and 15%, 50% and 100% r.h. as well as an exposure of 180 days at 0 degrees C and 100% r.h. At 0 degrees C the percent survival was 75% for the males and 40% for the females at 50% r.h. but 100% for males and 95% for the females at 15% r.h. after exposure of 180 days. Oviposition of engorged females occurred at a temperature range of 10-27 degrees C, at 10 degrees C merely at 50% and 100% r.h. The percentage of ovipositioning females amounted to at least 80% apart from 10 degrees C and 50% r.h. being only 10%. The egg index and the egg conversion index as well as the larvae index and the larvae conversion index generally increased with rising temperature and relative humidity. The indices were lowest at 10 degrees C and 50% r.h. and were highest at 20 degrees C and 27 degrees C at 100% r.h. The reproduction capability of engorged female ticks, held at -10 degrees C, 0 degrees C and 5 degrees C and 15%, 50% and 100% r.h. and transferred to 20 degrees C and 95% r.h., persisted for 10 weeks at -10 degrees C and for 2 weeks at 0 degrees C at the most, but for at least 20 weeks at 5 degrees C. There were no significant differences of the preoviposition periods, egg indices and larvae indices as well as of the minimum embryonic developmental times and hatching rates with regard to the preceding incubation conditions and the length of the ticks' exposure.

Animals↗
PubMed1994

A shared epitope found in the major paralysis inducing tick species of Africa.

Cross-reactivity between all the paralysis inducing tick species of veterinary relevance in Africa was demonstrated, by using a monoclonal antibody directed against the paralysis inducing toxin of Rhipicephalus evertsi evertsi. Western blot results, together with amino acid composition studies indicated that this monoclonal antibody recognizes protein bands of similar molecular mass and amino acid composition in R. evertsi evertsi and Ixodes rubicundus. This suggests that the Karoo paralysis toxin of I. rubicundus is possibly also a trimer with a high degree of homology to the spring lamb paralysis toxin of R. evertsi evertsi. The conclusive identity of these protein bands of I. rubicundus could not be shown. Bio-assay studies performed on 1-day-old chickens suggested that the anti-spring lamb paralysis toxin monoclonal antibody also recognizes the paralysis toxin present in Argas (Persicargas) walkerae, by rendering some degree of protection against the effect of this toxin.

Africa↗
PubMed1994

[Eimeria leuckarti infections in foals and their mothers in upper Bavaria].

In this epidemiological study 30 mares and their foals from seven farms in Upper Bavaria were investigated. Eimeria-leuckarti-oocysts were found in 24 foals (80%), but only in one mare. Oocysts were first detected 28 days post partum at the earliest and 191 days post partum at the latest. In foals, excretion of oocysts usually occurred intermittently with coproscopically negative intervals of up to 15 weeks, and was most frequent in June (8 foals), July (17 foals), and August (10 foals). With the exception of two animals which had mild diarrhoea, the oocyst-shedding foals showed no clinical signs.

Animals↗
PubMed1994

[Hepatozoon canis: an important parasitic infection in dogs].

This paper reports on a case of hepatozoonosis of a dog imported from Italy to Germany. A survey of the biology and ecology of the causative agent as well as the pathogenesis, clinics, diagnosis, therapy and prophylaxis of Hepatozoon canis infection is presented.

Animals↗
PubMed1993

The localization of a paralysis toxin in granules and nuclei of prefed female Rhipicephalus evertsi evertsi tick salivary gland cells.

A monoclonal antibody directed against a paralysis toxin of Rhipicephalus evertsi evertsi ticks was used to localize the toxin in cytoplasmic granules and, surprisingly, chromatin of the nuclei of cells which resemble the "b" cell type in the salivary glands of Rhipicephalus appendiculatus, Boophilus microplus and Ixodes holocyclus. The association of toxin with chromatin indicates that the toxin may have a regulatory function. Evidence is provided to support the view that the toxin is made up of three identical sub-units, with only the trimeric form being toxic.

Amino Acids↗
PubMed1993

Investigations into lymphocyte transformation and histamine release by basophils in sheep repeatedly infested with Rhipicephalus evertsi evertsi ticks.

The immune response of a natural host of Rhipicephalus evertsi evertsi to feeding by this tick species was investigated with respect to the effects of tick salivary gland extracts on the transformation of peripheral blood lymphocytes and the release of histamine by basophils obtained from repeatedly infested sheep. The results indicated that there was no stimulation of lymphocyte transformation but that histamine release was elevated 10 fold after four infestations. Although this suggests a hypersensitivity reaction, believed to be a major factor in resistance to tick feeding, it was observed that ticks fed normally even after four infestations with 28 day intervals in between. These results emphasize the adaptation of ticks to feeding on their natural hosts.

Animals↗
PubMed1992

Morphology and structural organization of spiracles in female Argas (Persicargas) walkerae (Acari: Argasidae).

Scanning electron microscopical investigations of fractures and corrosion casts of the spiracles from female A. walkerae ticks revealed a four-part structure, consisting of spiracular plate, ostium and macula forming the external closure, followed by the subostial space and the vestibulum of regulable volume, as well as the atrial chamber as the innermost part from which the main tracheal trunks originate. On the average, the spiracular plate was 158 microns long and 188 microns at the broadest width. It consisted of a thin, highly perforated external and a thick internal layer, which enclosed the interpedicellar space with numerous stout pedicels. In its posterior region, the spiracular plate was covered by the macula, which was up to 80 microns in length and 110 microns in width. The interpedicellar cavity opened into the subostial space measuring 95.5 microns in length and 159.6 microns in width, which proceeded into the 112-microns long vestibulum. The roof of the vestibulum was flexible and could be everted and inverted. Inverted, the roof formed a quadratic bulge with numerous deep cuticular folds, which confined the lumen of the vestibulum either partially or completely. In corrosion casts, the roof was everted to a length of up to 89.3 microns. In the posterior part of the vestibulum, as well as in the initial fourth of the atrial chamber, numerous anvil-, cone- or drop-like cuticular projections were arranged in wedge-like fashion. The atrial chamber was almost spherical with a diameter of 138.4 microns. Five main tracheal trunks of different luminal diameter as well as numerous channels opened into the atrial chamber.

Animals↗
PubMed1992

[Trichomonad infections of the oral cavity in cats in south Germany].

In this investigation trichomonads were isolated from the oral cavity in 21 of 110 examined cats, and only from those which were simultaneously FeLV, FIV or FIP positive. By means of scanning electron microscopy the trichomonads were shown to be round or piriform parasites which were on average 7.9 microns long and 6.2 microns wide at maximum width. They had 4 anterior flagella, which were on average 9.4 microns long, an undulating membrane measuring 6.7 microns with no trailing flagellum as well as an axostyle extending on average 5.0 microns beyond the body, and therefore should be attributed to the genus Trichomonas.

Animals↗
PubMed1992

[Trichomonad infections of the oral cavity in horses in southern Germany].

Trichomonads of the oral cavity were found in 9 of 60 investigated horses. Apart from dental tartar, the oral cavity showed no clinical signs in all positive horses. The clinical investigation of these horses additionally revealed colic in 4 and coughing in 4 horses as well as lumbago in 1 animal. By means of scanning electron microscopy the trichomonads were shown to be round or piriform with an average length of 7.6 microns and greatest width of 6.3 microns. They had 4 anterior flagella with an average length of 8.3 microns, an undulating membrane measuring 8.7 microns with no trailing flagellum as well as an axostyle extending on average 7.8 microns beyond the body, and therefore have to be placed into the genus Trichomonas.

Animals↗
PubMed1992

[Fauna and incidence of endoparasites in kittens and their mothers from different husbandry situations in south Germany].

In this epidemiological study 100 litters of Southern Germany were investigated. 70 litters were kept on farms and 30 litters originated from mother cats kept indoors. At least 9 species were detected in litters from farms, 77.1% of these litters were infected with T. cati, 1.4% with hookworms, 10% with Capillaria, 10% with H. taeniaeformis, 67.1% with I. felis, 48.6% with I. rivolta, 17.1% with Toxoplasma/Hammondia, 4.3% with C. parvum and 1.4% with Giardia. In litters kept indoors only 5 species were established. 3.3% were infected with T. cati, 46.6% with I. felis, 33.3% with I. rivolta, 6.6% with Giardia and 3.3% with C. parvum. Analogous differences as regards to the keeping conditions existed also for the mother cats.

Animal Husbandry↗
PubMed1991

On the reaction of adult Rhipicephalus evertsi mimeticus and Hyalomma truncatum to horizontally incidenting optical radiation of various wavelengths ranges and different irradiances and to optical radiation of a sun-simulating wavelength spectrum.

The valence of horizontally incidenting light/optical radiation for host-seeking-inclined ixodid ticks was investigated by exposing male and female adults of Rhipicephalus evertsi mimeticus and Hyalomma truncatum to narrow-band monochromatic radiation in the wavelength range of 300-801 nm at irradiances corresponding to an overcast to clear sunny day, a cloudy day and a full-moon night as well as to optical radiation of a sun-simulating wavelength spectrum of 190-2600 nm within a test chamber from which other stimuli were excluded. It was demonstrated that independent of sex, adult ticks of R. e. mimeticus and H. truncatum responded to a wide wavelength spectrum in the visible and UV range, even at irradiances corresponding to a full-moon night. Interspecific differences existed in the degree and extent of the response as well as in the spectral sensitivity. Ticks of H. truncatum consistently showed a faster and stronger response and reacted phototactically positively in higher percentages than adults of R. e. mimeticus. Independent of wavelength range and irradiance, predominantly only few R. e. mimeticus ticks were stimulated to positive phototaxis, whereas at least 33.3% (in most cases, 50%) and maximally greater than 80% of H. truncatum adults reacted phototactically positively. Spectral sensitivity maxima were demonstrated at the yellow and red light and at the UV-A waveband width for R. e. mimeticus and at the violet, blue, green and yellow light wavelength for H. truncatum. With decreasing irradiance, the spectral sensitivity shifted to the blue wavelength range.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Investigations on the host seeking and finding of Argas (Persicargas) walkerae (Ixodoidea: Argasidae).

In investigations concerning the influence of stimuli emitted by chickens on the host-finding behaviour of hungry female adult Argas walkerae ticks, we found that 92.5% of the ticks migrated to the stimulus source following their simultaneous exposure to odours and to a CO2 gradient increasing in the direction of the chicken, as opposed to 67.5% following their exposure to kairomones of chickens in the absence of CO2. Migration of the ticks toward the stimulus source was precipitated by a wide range of CO2 concentrations (varying from 0.06 to 1 vol% within the odour mixture) but always required an increasing CO2 gradient in the direction of the chicken, whereby differences in concentration of 0.01 vol% over a distance of 2.5 cm were sufficient. During exclusive confrontation with either CO2 or heat in a gradient otherwise analogous to that emitted by a chicken, only 27.5% and 55% of the female ticks migrated to the stimulus source, respectively. Accordingly, odours emitted by chickens are considered to represent an essential stimulus modality, whereas body heat and CO2 are regarded merely as secondary, non-specific stimulatory agents. Investigations involving the exposure of ticks to a habitat similar to a chicken roost revealed that host seeking and finding are not influenced by gravity and occur only in darkness and that the portion of host-finding ticks diminishes with increasing distance from the blood donor.

Animals↗
PubMed1991

Morphology and structural organization of Haller's organ during postembryonic development of Argas (Persicargas) walkerae (Ixodoidea: Argasidae).

Scanning-electron-microscopic investigations of Haller's organ in larvae, nymphs I, II, III and IV, and male and female adult Argas (Persicargas) walkerae ticks showed that morphology and structural organization change during postembryonic development. Stage-dependent differences existed regarding setal numbers of the anterior pit as well as formation and reticulation of cuticular projections in the capsule cavity. The anterior pit increased in size in the course of postembryonic development. It contained only seven setae in larvae, one conical, setiform and grooved seta each as well as two porose and fine setae. Nymphs I, II, III and IV adult ticks had equal numbers of setae; however, one additional unilaterally serrate and grooved seta each were present. Setal length increased continuously during postembryonic development and attained maximum values in adult ticks. The capsule consisted of roof and cavity and was located distinctly lateral in larvae, slightly lateral in nymphs I and II, and in all other stages directly on the longitudinal axis of tarsus. The capsule roof showed a reticular structure. The slit-like main aperture was located peripherally and arranged transversally to the longitudinal axis of tarsus I in larvae. Nymphs and adult ticks had a central, circular main aperture. Stage-dependent cuticular projections of varying form protruded into the capsule cavity. Larvae had only single, free-standing projections which ramified slightly and communicated with each other. Projections were more heavily reticulated in nymphs I and II. In nymphs III and IV as well as male and female adult ticks, a long centrally situated tube of reticular appearance was seen, which was supported by a large number of radially organized and interlocking pillars and communicated with the capsule roof. In all tick stages there were always four porose setae present, arranged on the capsule floor.

Animals↗
PubMed1991

[Helminth infections in wild boars kept in enclosures in southern Germany: severity of infections and fecal intensity].

To determine the intensity of helminth infection and egg output with regard to age and sex of wild boar, stomachs and intestines of 124, lungs of 62, and livers of 39 animals from 5 enclosures in Southern Germany were examined. The evaluation of the intensity of infection showed 579.4 worms per animal for Hyostrongylus rubidus, 510.4 for Globocephalus longemucronatus, 476.9 for Oesophagostomum dentatum, 476.9 for O. quadrispinulatum, 254.2 for Metastrongylus pudendotectus, 176.9 for M. salmi, 140 for Physocephalus sexalatus, 56.9 for M. apri, 45.4 for Trichuris suis, and 3.3 for Ascaris suum. 33.6 liver flukes per infected wild boar were also found. Additionally 2 metacestodes of Taenia hydatigena on the serous liver coat of an adult sow were found. The worm burden with respect to age of the animals showed no or only minimal age related differences, whereas a large number of O. dentatum and O. quadrispinulatum was found in adults compared to younger wild boars. The evaluation of the intensity of infection with regard to sex of the animals showed higher values only for H. rubidus, O. dentatum, O. quadrispinulatum and P. sexalatus in males compared to female wild boars. The egg output intensity in the samples taken from the rectum was in average 3300 EpG for A. suum, 450.4 EpG for Oesophagostomum, 445.9 EpG for Globocephalus, 220 EpG for Trichuris, 207.9 EpG for Metastrongylus, 190.8 EpG for Hyostrongylus and 67 EpG for Capillaris. The egg output with respect to age showed higher values in younger wild boars than in adults.

Age Factors↗