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Biomedical subjects

R Gothe

Publications and source records attributed to R Gothe.

At least 19 recordsLinked to original sources
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↗
PubMed1991

[Babesiosis of dogs in Germany: epidemiologic case analysis].

Between January 1987 and February 1990 Babesia infections were detected in 320 dogs in Germany by means of microscopical and/or serological methods. It was found, that 316 dogs were infected with Babesia canis and 4 animals with Babesia gibsoni. Of the Babesia-canis-positive dogs 184 were abroad up to 4 months before diagnosis, mainly in France, Spain and Italy, but also in Hungary, Greece, Jugoslavia, Portugal, Morocco, Togo, Pakistan, Sri Lanka, Malaysia, Turkey, Romania, Austria and the Netherlands. For further 36 dogs the possible place of infection for Babesia canis could not be clarified geographically. 5 dogs each were simultaneously infested with Rhipicephalus sanguineus and Dermacentor reticulatus, respectively. The four dogs infected with Babesia gibsoni were previously in Sri Lanka (2), Brazil (1) or Algeria/Kenya (1). In 88 dogs from the Offenburg/Lahr/Freiburg area, which were not abroad, infections with Babesia canis were diagnosed from January to June as well as from September to December, however, most cases occurring in April and May. Of these dogs approximately 20% were found to be infested with Dermacentor reticulatus. These ticks were also collected on the vegetation in the Offenburg area. Therefore, an endemic focus of Babesia canis can be deduced in the area of Offenburg/Lahr/Freiburg and Dermacentor reticulatus as vector also in Germany.

Animals↗
PubMed1990

On the morphology and organization of the eye of unfed adult Rhipicephalus evertsi mimeticus (Acari: Ixodidae).

Investigations by scanning and transmission electron microscopy and freeze-etching revealed that eyes of adult Rhipicephalus evertsi mimeticus consist of a lens and photoreceptor cells, which are separated by an acellular layer and the hypodermis. The lens contains numerous pore channels, which open beneath the epicuticula of the outer portion, converge uninterrupted to the inner closure and end in approximately 420 pore fields. The inner closure of the lens is formed as a deep circular invagination. Beneath the hypodermis and perpendicular to the lens, a group of approximately 20 highly differentiated photoreceptor cells in a rosette-like arrangement is localized within the invagination of the lens. Each photoreceptor cell is characterized terminally by numerous, tightly packed and parallel-running microvilli, which are oriented perpendicularly to the lenticular pore channels.

Animals↗
PubMed1990

Eimeria infections of sheep in northwest Germany.

To investigate the incidence of ovine Eimeria spp. and seasonal dynamics in oocyst output, fecal samples of sheep from three different management systems were collected monthly over a 1-year period and examined for oocysts. A total of 10 species of Eimeria were observed. The most frequent species were E. bakuensis, E. ovinoidalis, E. weybridgensis/crandallis, E. parva and E. ahsata whereas E. faurei, E. granulosa, E. intricata and E. pallida were found less often. Lambs passed larger numbers of oocysts in their feces than either ewes or yearlings.

Animals↗
PubMed1990

[The frequency of coccidial infection in dog families of different husbandry and breeds in south Germany].

Oocysts and/or sporocysts were detected in 50 litters and 37 bitches of 100 coproscopically examined dog families in Southern Germany. Oocysts of Isospora spp. were excreted by 41 of the 50 positive litters, 36 and 16 litters shedding oocysts of Isospora ohioensis/burrowsi and I. canis, respectively. Sporocysts of Sarcocystis spp. and oocysts of Hammondia heydorni were detected in 12 and 7 litters, respectively. The excretion rates of the dams were arranged analogous to the detection of oocysts of Isospora spp. in 25 animals. Sporocysts of Sarcocystis and oocysts of H. heydorni were excreted by 19 and 6 dams, respectively. With regard to husbandry conditions distinct differences were established only for Isospora spp., because dog families kept in kennels always revealed higher excretion levels than dog mothers and their litters kept indoors. Excretion intensities increased directly proportional to the number of additional adult dogs and the number of litters born per year/stock, reaching maximum values of 80-100%. Analysis revealed no breed-related differences.

Animal Husbandry↗
PubMed1990

The detection and isolation of a paralysis toxin present in Argas (Persicargas) walkerae.

One-day-old leghorn chickens were used in a laboratory assay to determine the toxicity of crude extracts of the tick Argas (Persicargas) walkerae and of fractions obtained during the isolation procedure. Extracts of unfed and engorged larvae, nymphae and females were tested using this in vivo test system. Only extracts of replete A. (P.) walkerae larvae produced paralysis. A toxic fraction was isolated from replete larval extracts by gel-permeation and ion-exchange chromatography. This fraction with a pI of 4,5, showed 2 major bands corresponding to a Mr of 32 kDa and 60 kDa after SDS-polyacrylamide gel electrophoresis.

Animals↗
PubMed1990

[Helminth infections in wild boars in enclosures in southern Germany: species spectrum and infection frequency].

To determine the helminth fauna of wild boars, 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 species composition revealed at least 13 species: Metastrongylus apri, M. salmi, M. pudendotectus, Physocephalus sexalatus, Hyostrongylus rubidus, Globocephalus longemucronatus, Ascaris suum, Trichuris suis, Oesophagostomum dentatum, O. quadrispinulatum, Fasciola hepatica, C. tenuicollis and Capillaria. The most frequently isolated species was M. salmi with 91.9%, followed by G. longemucronatus with 91.1%, M. apri with 88.7%, M. pudendotectus with 87.1%, P. sexalatus with 51.6%, O. dentatum with 46%, T. suis with 30.6%, H. rubidus with 14.5%, A. suum with 12.1% and O. quadrispinulatum with 8.1%. Differences in the prevalence of infection, determined for animals up to 1 year old, 1-2 year-old and adults, were minimal for Metastrongylus spp. and G. longemucronatus. P. sexalatus, T. suis and A. suum, however, occurred more often in 1 year old, whereas H. rubidus, O. dentatum and O. quadrispinulatum were isolated more often from adults. A correlation of the infection rate with the sex of the animals was not found.

Animals↗
PubMed1990

[Spectrum of species and infection frequency of endoparasites in bitches and their puppies in south Germany].

Toxocara canis, Toxascaris leonina, hookworms, Trichuris vulpis, Strongyloides, Hammondia heydorni, Sarcocystis spp., Isospora canis and Isospora ohioensis and/or Isospora burrowsi of at least 9 species were detected in 100 randomly selected dog families in Southern Germany. Examinations carried out 5 to 9 times at weekly intervals revealed a monoinfection in 37 litters, infection with two parasite species in 28 litters, with three species in 10 litters and with four species in 6 litters. During the investigation period, 29 of the examined litters did not excrete helminth eggs, and, of these, 19 also did not excrete oocysts/sporocysts. In order of decreasing frequency among the dog families, the excretion extent of the litters and their mothers was as follows: Toxocara canis 67% and 45%, Isospora ohioensis/burrowsi 36% and 24%, Sarcocystis spp. 12% and 19%, Isospora canis 16% and 8%, Hammondia heydorni 7% and 6%, hookworms 6% and 7% and Toxascaris leonina 3% and 8%, respectively. Trichuris vulpis and Strongyloides eggs were only detected in 6 and 3 of the bitches, respectively.

Animals↗
PubMed1990

[Toxocara canis: frequency of detection and extent of infection in bitches of various breeds and husbandry and their litters in South Germany].

Epidemiological investigations of 100 randomly selected dog families in Southern Germany revealed eggs of Toxocara canis in 67% of the litters and in 45% of the bitches. Eggs were isolated from litters at the earliest on the 16th day and at the latest on the 55th day post partum, in bitches on the 19th and 60th day respectively after giving birth. With regard to the coproscopically detected frequency of T. canis eggs in separate analyses of the dog breeds, only slight differences were found; very large breeds, however, revealed substantially a greater excretion extent. An evaluation exclusively concerned with the way the dog families were kept showed a higher percentage of 76.2% for litters from kennels than among those kept indoors, which amounted only to 51.4%. Relating the excretion extent to the number of additionally kept fully grown dogs/breeder, evident correlations were found, as the number of positive litters increased together with the number of additionally kept adult dogs/dog family. In comparison with dog families exclusively kept indoors, kennel dogs had a higher extent of excretion. Regarding the number of litters born per year/stock compared with excretion extent a positive correlation could be drawn for dog families up to 5 litters/year only. The number of litters born per bitch had no influence on the excretion extent of the litters. Correlations between the number of anthelminthic treatments of litters or bitches during and following pregnancy and the excretion extent of T. canis could not be deduced. The litters remained positive even after 5-8 treatments during the investigation period of 9 weeks and positive results continued after the puppies had been sold.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

[Demodicosis of dogs--a factorial disease?].

Demodex canis is a normal resident of the intact canine skin, being present in small numbers in virtually every dog. Most animals are only carriers of the mites and do not develop clinical symptoms, therefore, demodectic mange has already to be considered as a factorial disease. The modus operandi of transition of clinically inapparent colonization of the mites into a disease may be explained according to investigations so far published multifactorially and thereby essentially as consequences of primary or secondary immunodepression. A primary immunodepression is initially based most probably on a hereditary defect of T-cells and is subsequently reinforced by substances, which are presumably synthesized and liberated not only by mites but also by secondary bacterial agents. A secondary immunodepression operates as trigger mechanism of a clinical manifestation after corticosteroid or cytostatic therapy or in course of underlying diseases of potentially immunodepressive nature, i.e., malignant neoplasia, hepatopathies, hyperadrenocorticism and lymphosarcoma.

Animals↗