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Biomedical subjects

R L Rausch

Publications and source records attributed to R L Rausch.

At least 55 records · Page 3Linked to original sources
PubMed1981

The karyotype of Echinococcus multilocularis (Cestoda: Taeniidae).

The chromosomes of Echinococcus multilocularis Leuckart, 1863 have been described, based on components of cells from the adult stage and the larval stage of the cestode. Chromosomal complements of 2n = 18, n = 9 were confirmed. The fundamental number of chromosomal arms were 24. Karyograms are presented, in which the 18 elements are grouped according to arm-ratios and size. An idiogram of G-bands is included.

Animals↗
PubMed1981

Characteristics of the larval Echinococcus vogeli Rausch and Bernstein, 1972 in the natural intermediate host, the paca, Cuniculus paca L. (Rodentia: Dasyproctidae).

In Colombia, the natural intermediate host of Echinococcus vogeli Rausch and Bernstein, 1972 is the paca, Cuniculus paca L. (Rodentia: Dasyproctidae). The larval cestode develops in the liver of the host, where it usually is situated superficially, partly exposed beneath Glisson's capsule. The infective larva consists of a subspherical to asymmetrical, fluid-filled vesicle, up to 30 mm in diameter, enclosed by a thick laminated membrane. It typically contains numerous chambers, often interconnected, produced by endogenous proliferation of germinal and laminated tissue, within which brood capsules arise in an irregular pattern from the germinal layer. Invasive growth by means of exogenous proliferation, typical of infections in man, was not observed in the natural intermediate host. The development of the larval cestode is described on the basis of material from pacas, supplemented by observations on early-stage lesions in experimentally infected nutrias, Myocastor coypus (Molina) (Rodentia: Capromyidae). The tissue response is characterized for early-stage, mature (infective), and degenerating larvae in the comparatively long-lived intermediate host. In addition to previously reported differences in size and form of rostellar hooks, other morphologic characteristics are defined by which the larval stage of E. vogeli is distinguished from that of E. oligarthrus (Diesing, 1863). Pathogenesis by the larval E. vogeli in man, like that by the larval E. multilocularis Leuckart, 1863, is the consequence of atypical proliferation of vesicles attributable to parasite-host incompatibility.

Animals↗
PubMed1981

Echinococcus infections in Colombian animals.

The results of a survey involving more than 4,000 Colombian mammals, carried out to detect Echinococcus infections, are presented. Adult worms were found in 5 of 121 carnivores: E. oligarthrus in 1 of 11 ocelots, 2 of 9 jaguarundi cats and single puma; and E. vogeli in 1 of 15 domestic dogs. Although bush dogs were present, none could be examined. Polycystic larvae were found in 96 of 325 pacas (29.5%) and in 6 of 1,168 (0.5%) spiny rats, Proechimys spp. None of the 118 agouti showed hydatids but an infected heart was provided by hunters. The paca's infection rate increased with age but was not related to sex or geographic region. In 73 of 96 pacas the infection was due to E. vogeli, and the cysts were located in the liver. In 3 it was due to E. oligarthrus and the hydatids were extrahepatic, mainly attached to muscles. In the remaining 20, the species involved could not be determined. The parasites in two of the spiny rats, and in the agouti heart were E. oligarthrus. Although most of the infected animals were collected in the eastern plains, other records and verbal information indicate that, at least in Colombia where man has not exterminated pacas, agoutis, wild canids and felids, one still can find enzootic neotropical Echinococcus infection. The cycle of E. vogeli involves the bush dog and paca as hosts, and that of E. oligarthrus, the paca, agouti, spiny rat, and several species of wild felids.

Animal Population Groups↗
PubMed1980

Alveolar hydatid disease. A review of clinical features of 33 indigenous cases of Echinococcus multilocularis infection in Alaskan Eskimos.

The clinical features of 33 cases of alveolar hydatid disease (AHD) in Alaskan Eskimos and a review of the surgical experience with this disease are presented. Among untreated patients, progression of the disease to a fatal outcome was observed in 70%. The primary hepatic lesion resembles cancer, and errors in diagnosis by both the surgeon and pathologist are common. Although surgical resection of the entire primary hepatic lesion offers the only proven curative treatment, only 26% of those explored were resectable. All seven patients resected for cure are alive 6-27 years post-operatively (average survival, 14.7 years). A 5-year experience with continuous mebendazole therapy in the management of five nonresectable cases of AHD indicates that a favorable effect of this drug is being observed. It now appears that Echinococcus infections are no longer the sole province of the surgeon. Although the role of medical therapy is not yet clearly defined, it must be considered in the management of all cases of AHD. The first reported locally-acquired case of AHD in the conterminous United States, and the widespread occurrence and expanding range of E. multilocularis in the north-central United States and south-central Canada, point to the increasing public health importance of alveolar hydatid disease.

Adolescent↗
PubMed1979

Alveolar hydatid disease in Minnesota. First human case acquired in the contiguous United States.

A 56-year-old woman from southwestern Minnesota underwent an extended left hepatic lobectomy to remove a large multinodular mass with a necrotic central cavity. The clinical, serological, and pathological findings led to the diagnosis of alveolar hydatid disease, and specific identification of Echinococcus multilocularis was achieved by growing mature larvas in voles inoculated intraperitoneally with tissue from the hepatic lesions. The patient probably acquired her infection some years previously from pet cats or dogs that had become infected by ingesting infected rodents. In North America E multilocularis is enzootic in the northern tundra zone of Alaska and Canada. Since 1964 the cestode has been recognized with increasing frequency in several north-central states, including Minnesota. The parasite may extend its range farther south, since suitable animal hosts occur throughout the United States.

Echinococcosis, Hepatic↗
PubMed1979

Echinococcus vogeli in man, with a review of polycystic hydatid disease in Colombia and neighboring countries.

Three cases of polycystic hydatid disease (PHD) from Colombia are reported and 11 others from the region are reviewed. When cysts from two patients were fed to a dog and an ocelot about 250 mature and gravid specimens of Echinococcus vogeli and two poorly developed strobilae, respectively, were recovered. These human cases constitute the first record of the larval stage of E. vogeli, previously known only from the strobilar stage in the type host, the bush dog (Speothos venaticus). Based on the morphological characteristics of the protoscolex rostellar hooks from other PHD cases (6 Colombian, 1 Ecuadorian, and 1 Panamanian), it was concluded that all were also due to E. vogeli, rather than to E. oligarthrus as had been previously suggested. Although E. oligarthrus is or may be present in the same areas, so far no human infection due to this parasite has been confirmed. Of the 14 cases reported, 13 were pathologically proven to be PHD. Clinically, eight had an undiagnosed tumor-like mass in or near the liver, one had a subcutaneous mass in the anterior sixth intercostal space, and in two the cysts were in the chest. Two were autopsy findings. In contrast to E. multilocularis, the cysts produced by E. vogeli were found to be relatively large and filled with fluid; brood capsules and protoscolices were numerous. Focal necrosis was commonly observed but large necrotic cavities were not seen. The main natural intermediate host is the paca (Cuniculus paca); man probably obtains the infection by contamination from feces of infected hunting dogs.

Adolescent↗
PubMed1978

Brucellosis in reindeer, Rangifer tarandus L., inoculated experimentally with Brucella suis, type 4.

An investigation of brucellosis caused by Brucella suis, type 4, in reindeer, Rangifer tarandus L., and other ungulates inoculated experimentally with virulent isolates was undertaken to observe the course of infection, follow titres of serum agglutins, and determine the extent to which intraspecific and interspecific transmission might occur among confined animals. Titres rose to maximum levels within 1 to 2 months following inoculation, decreased during the next 4 months, and persisted at low levels thereafter. Titres in uninoculated associates of these animals followed the same pattern, but at lower levels. Abortion occurred in reindeer that received large numbers of organisms; females receiving smaller numbers at an earlier stage of gestation produced normal fawns. Possible explanations for the holarctic distribution of B. suis, type 4, in reindeer are considered.

Animals↗
PubMed1978

A clinical trial of mebendazole in the treatment of alveolar hydatid disease.

In July 1974, mebendazole was reported to be effective against the larval stage of Echinococcus granulosus in experimentally infected mice. A clinical trial of mebendazole was initiated in December 1974 in 4 patients with far advanced, nonresectable lesions caused by Echinococcus multilocularis. A daily dose of 40 mg of the drug per kg of body weight was administered to the 4 patients for more than 3 years. No evidence of toxicity or adverse reactions has been observed. Detectable plasma mebendazole concentrations were achieved with high-dose mebendazole therapy. Serum concentrations of IgE increased and decreased early in therapy. There was no evidence that the larval cestode was killed. The metastatic lesions appeared to be stabilized or diminished, and over-all clinical results were encouraging. Progressively enlarging thoracic metastases in 2 patients regressed during therapy, and symptomatic improvement was observed in all 4 patients. Mebendazole, a highly effective antihelmintic in enteric infections, is poorly absorbed by the gastrointestinal tract. Resulting low serum concentrations limit treatment of the massive, scirrhous lesions characteristic of E. multilocularis infections. Nevertheless, encouraging clinical responses observed with mebendazole therapy suggest that a more soluble form of this or a related drug might prove highly effective in the medical management of hydatid disease in humans.

Administration, Oral↗
PubMed1978

Discrimination of the larval stages of Echinococcus oligarthrus (Diesing, 1863) and E. vogeli Rausch and Bernstein, 1972 (Cestoda: Taeniidae).

Rostellar hooks of protoscolices from known larval stages of Echinococcus oligarthrus (Diesing, 1863) and E. vogeli Rausch and Bernstein, 1972 were compared to determine whether morphologic differences could be defined. The large and small hooks, respectively, of the two species were found to differ significantly in length (P = less than 0.0001) as well as in relative proportions. Host-related variation in lengths of hooks was not observed. Dimensions of the rostellar hooks were found to provide means for the discrimination of the larval stages of E. oligarthrus and E. vogeli, of which the latter is the cause of polycystic hydatid disease in man in South and Central America. The defined criteria were used in the identification of larvae from wild rodents and man.

Echinococcus↗
PubMed1977

Detection of the Echinococcus granulosus diagnostic arc 5 in sera from patients with surgically-confirmed E. multilocularis infection.

The Echinococcus granulosus diagnostic arc 5 was revealed by sera from an Alaskan and a Swiss patient with surgically confirmed E. multilocularis infections. The possibility of each patient harboring a concurrent infection with both parasites may be disregarded on the basis of radiologic, scintillographic and surgical data. This conclusion is compatible with ecologic and epidemiologic considerations. These observations suggest that the immunoelectrophoresis test based on arc 5 positivity is not E. granulosus-specific as originally described.

Adult↗
PubMed1977

Aploparaksis borealis sp. n. (Cestoda: Hymenolepididae) from passeriform and charadriiform birds in Chukotka and Alaska.

Aploparaksis borealis sp. n. (Cestoda: Hymenolepididae), from the long-tailed jaeger, Stercorarisu longicaudus Vieillot, on the Seward Peninsula, Alaska, and from the red-throated pipit, Anthus cervinus (Pallas), and the Lapland longspur, Calcarius lapponicus (Linnaeus), in Chukotka, northestern Siberia, is described. This cestode is distinguished by the structure of the cirrus and other morphologic characters from other species of Aploparaksis Clerc 1903 in which there are 10 rostellar hooks and the vitelline gland is aporal to the ovary. A. borealis is the first species of Aploparaksis to be reported from birds representing 2 orders (Passeriformes and Charadriiformes).

Alaska↗
PubMed1977

Monoecocestus thomasi sp. n. (Cestoda: Anoplocephalidae) from the northern flying squirrel, Glaucomys sabrinus (Shaw), in Oregon.

Monoecocestus thomasi sp. n. (Cestoda: Anoplocephalidae), from the northern flying squirrel, Glaucomys sabrinus (Shaw), in Oregon, is described and distinguished from its congeners. Monoecocestus thomasi is the sixth species of Monoecocestus to be described from nearctic rodents, and the first from a member of the family Sciuridae. Our comparisons of taxonomic characters of the nominal species of Monoecocestus in North American rodents have shown that M. giganticus Buhler 1970 is a synonym of M. americanus (Stiles 1895), both from the porcupine, Erethizon dorsatum (Linnaeus). Insemination in Monoecocestus ssp. is discussed, with the conclusion that it takes place only by way of the vagina in early immature segments.

Animals↗