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Biomedical subjects

R Muller

Publications and source records attributed to R Muller.

At least 73 records · Page 4Linked to original sources

[A 5th filaria of the genus Dipetalonema, parasite of South American monkeys].

Description of D. freitasi n. sp., a parasite of Cebus capucinus: this species, close to D. caudispina, is distinguished by the slightly more complex structure of the vagina and right spicule, the lack of area rugosa on the tail and by the shorter microfilaria. Additional morphological data on the male of D. robini Petit et al., 1985 are given. A comparative table of 4 principal evolutive characters of the genus Dipetalonema (vagina, left and right spicules, epithelio-muscular body wall) is given. D. caudispina and D. freitasi n. sp. represent a small primitive group opposed to the more evolved one made up of D. robini, D. gracile and D. graciliformis.

Animals↗

Human cysticercosis and intestinal parasitism amongst the Ekari people of Irian Jaya.

A random sample of 242 people showed that 42 had palpable cysts of Taenia solium. Faecal examination recovered eggs of T. solium in seven (3%), while Trichuris (83%), Ascaris (83%), hookworms (76%), Strongyloides stercoralis (10%) and Strongyloides sp. (29%), Entamoeba histolytica (14%), Entamoeba coli (22%), Entamoeba hartmanni (7%), Entamoeba polecki (7%), Balantidium coli (9%) and Dientamoeba fragilis (21%) were the most common other intestinal parasites encountered. ELISA tests, using antigens prepared from adults and eggs of T. solium and from cysticerci of T. saginata were not very sensitive, the last diagnosing less than half of known positives while still retaining good specificity.

Adolescent↗

Optimization of culture conditions for the maintenance of Onchocerca gutturosa adult worms in vitro.

A series of experiments examined the effects of various media, serum supplements, gas phases and the incorporation of mammalian cell feeder layers on the survival of Onchocerca gutturosa adult worms in vitro. The survival of male worms was poor in all media tested that were not supplemented with inactivated foetal calf serum (IFCS), with improved but variable survival in media supplemented with 10-30% IFCS. Using a cell-free system in an atmosphere of 5% CO2 in air, good results were obtained in medium NCTC 135 + 10% IFCS (median survival time 39 days, range 25-41). Marginally better survival was obtained with the same medium in an atmosphere of 95% N2/5% CO2 (median 45 days, range 25-56) and with a 1:1 mixture of media NCTC 135 and IMDM + 10% IFCS (median 38 days, range 38-51). Survival was enhanced in culture systems which incorporated bovine kidney (MDBK) cells, bovine trachea (EBTR) cells and monkey kidney (LLCMK2) cells. Exceptionally long survival was obtained using medium MEM + 10% IFCS + LLCMK2 cells under a gas phase of 5% CO2 in air, in which male worms survived from approximately 6 to over 7 months. Under similar conditions, female worms were also maintained for periods of up to 6 months and 5 out of 18 specimens released microfilariae into the culture system. The long-term culture described in this study will be useful for basic biochemical, chemotherapeutic and immunological studies in vitro.

Animals↗

The trainee and the transfer case: why is this case different from all other cases?

Eighteen therapists-in-training working with outpatient transfer cases were interviewed by the author. Seven major factors which impacted upon the trainees' treatment of these cases were identified. Two case studies are presented to illustrate the interactive nature of these factors. The implications for supervision and future research are discussed.

Adult↗

Further studies on the resistance to Onchocerca microfilariae in CBA mice.

Various factors governing resistance to the microfilariae (mf) of Onchocerca lienalis in mice have been examined to provide baseline data for use of this model in immunological studies. The survival of mf during a primary infection followed a similar course in the skin from most anatomical regions of the body. Mice were highly resistant to secondary infections, manifested by parasite densities over the body that were reduced by 83-100% compared with controls. Recoveries of mf from the ears, used in later experiments, were a representative measure of parasite survival in other skin sites. The resistance to challenge induced by a primary infection was not dependent on the route of administration (intravenous, intraperitoneal, subcutaneous and intramuscular) of the latter and was apparently systemic. Primary infections of various durations that were chemically-abbreviated conferred maximum protection when of 15 days or longer (95-97%) and substantial resistance when of only 7 days (84%). Similar levels of protection were demonstrated in mice that were sensitized with single or multiply-divided mf doses, or challenged in a similar manner. Primary infections containing as few as 20 mf induced almost the same degree of protection (80%) as 50 to 10,000 mf (88-97%). Apparently, resistance to re-exposure with O. lienalis mf is mediated by a highly effective mechanism(s) in CBA mice.

Animals↗

Fulminant disseminated carcinomatosis arising from squamous cell carcinoma of the tongue.

Squamous cell carcinoma of the tongue tends to be an indolent disease. Tumors that present as small, localized lesions of the anterior tongue have a median five-year survival greater than 70 percent whether treated by irradiation or surgery. Distant metastases occur in only 7.5 percent. This report describes a well-differentiated T1N0M0 squamous cell carcinoma of the anterior tongue that progressed from diagnosis to death of the patient in less than nine months. At autopsy, the tumor had disseminated widely, including simultaneous metastases to all layers of the heart. It is concluded that factors other than morphology and anatomic extent at presentation may modify prognosis in squamous cell carcinoma of the tongue.

Carcinoma, Squamous Cell↗

Acquired immunodeficiency syndrome. Distinctive features of bone marrow biopsies.

Bone marrow biopsies from 30 patients with acquired immunodeficiency syndrome (AIDS), diagnosed according to accepted clinical criteria, were studied in order to determine if characteristic histopathologic features were present. The biopsies were compared with 20 biopsy specimens submitted from patients with fever of unknown origin or with known neoplastic disease, including four biopsies from patients with a history of narcotics addiction being treated in the methadone clinic, and with biopsies from three homosexual men who did not have AIDS. Characteristic biopsy features were recognized in 31 (86%) of 36 biopsy specimens from AIDS patients. Nineteen of 36 patients (53%) showed a distinctive pattern of hypercellularity in which hematic cells (immature granulocytic cells, megakaryocytes, eosinophils, and large lymphocytes) separated, but did not efface, fat cells; these cells were designated as "AIDS-pattern." Twelve specimens showed a less complete (probable-AIDS) bone marrow change. Reticulin fibers were increased in 28 of 36 biopsies.

Acquired Immunodeficiency Syndrome↗

HBV-vaccination in recipients of kidney allografts.

Recipients of renal transplants were vaccinated with 20 ng hepatitis B surface antigen aluminium-adsorbed vaccine in order to gauge their resistance to hepatitis B infection, to which these patients are at high risk. The patients were given three 40 micrograms doses of the vaccine over a period of six months and their antibody titres were measured. Only 9% of patients developed antibodies to hepatitis B and it was established that if possible all patients should receive at least one injection of hepatitis B vaccine prior to surgery.

Hepatitis B↗

Immunity to onchocerca lienalis microfilariae in mice. I. Resistance induced by the homologous parasite.

The model of Onchocerca lienalis microfilariae injected into inbred CBA/HT6T6 mice has been examined for its value to study immunity to the skin-dwelling microfilariae in onchocerciasis. Mice injected with living microfilariae during primary or secondary infections exhibited a high level of resistance to challenge relative to normal controls (91-98% reduction in recoveries). The survival of microfilariae during a primary infection was significantly prolonged in T-cell deprived animals compared with immunologically intact mice. Serum and spleen cells transferred from donors 90 days after infection conferred significant protection in syngeneic recipients to challenge with microfilariae (59% reduction in recoveries compared with controls). Boostered injections with freeze-killed or fragmented microfilariae reduced parasite recoveries after challenge by 39-78%: none of 5 adjuvant preparations enhanced the protective effect. Mice exposed to living infective larvae or adult males of O. lienalis also exhibited lowered recoveries of microfilariae following a challenge infection. It is concluded that the mouse model offers potential for immunological studies on the microfilariae in onchocerciasis, which have hitherto been limited because of the lack of suitable laboratory hosts.

Adjuvants, Immunologic↗

Catastrophic uterine rupture.

Twenty-three cases of major rupture of the pregnant uterus in which the life of the mother and/or fetus were endangered are presented. Fourteen cases (61.3%) resulted from rupture of a previous cesarean section scar. Rupture of an intact pregnant uterus in nine cases (38.7%) was related to oxytocic drug administration, obstetric manipulation, labor disorders, or external trauma. These most devastating cases were associated with grande multiparity. Rupture of the intact uterus was characterized by increased blood loss and need for transfusion. When compared with rupture of the scarred uterus, however, operating times and mortality rates were similar. Fetal mortality was 35% (eight of 23) and there were no maternal deaths.

Adult↗

Excreta disposal facilities and intestinal parasitism in urban Africa: preliminary studies in Botswana, Ghana and Zambia.

The relationships between intestinal parasitism and excreta disposal technologies in Gaborone (Botswana), Ndola (Zambia) and Kumasi (Ghana) were investigated. Parasitic prevalence and intensity rates amongst groups of urban residents having similar socio-economic status and housing, but different excreta disposal technologies, were compared. In Gaborone, there was no evidence of a difference in intestinal parasitism between those using aqua privies and having access to public taps and those in identical houses enjoying flush toilets, in-house water connections and showers. In Ndola, the group with sewered aqua privies had larger houses, cleaner toilets, better water supplies, longer residence and more people in paid employment than the groups using pit latrines or communal flush toilets. Despite this, the sewered aqua privy users were not found to be different from the other groups with regard to hookworm and protozoal infection but had significantly higher Ascaris infection rates. In Kumasi, despite the differences in toilet type--from squalid communal aqua privies, through often fouled bucket latrines to well-maintained flush toilet systems--and despite also the differences in water provision, no evidence was obtained of any differences in intestinal parasitism between the groups studied. These findings suggest that the provision of superior water and sanitation facilities to a small cluster of houses, or to houses scattered through an area, may not protect those families from infection if the over-all level of faecal contamination of the environment is high. The sample sizes and response rates achieved in this study were low and follow-up studies, employing the same methodology but with larger samples, are recommended.

Adolescent↗

[Dermatoses in the spinning and weaving industry].

In order to detect cutaneous alterations among the workers of a textile industry, the authors proceeded to a dermatologic examination of 1207 persons, with special emphasis on skin conditions of the fingers and toes. The most noticeable and specific alteration related to the work was a linear hyperkeratosis of the lateral aspects of the first and second finger of the right hand--the fingers of prehension--submitted to repeated micro-traumas due to the manipulation of the threads. In second place in order of frequency were the intertriginous inflammation of the toes, due to the high level of temperature and humidity prevalent in some areas of the plant, besides the use of inadequate shoes and socks. Some suggestions are made for reducing the incidence of dermatologic risks.

Adolescent↗

A survey of parasites in primary school children in Dominica, West Indies.

A study of Dominican school children aged four to twelve years showed that infection with gastrointestinal parasites was very common. Trichuris was found in the stools in 92% of the children, Ascaris in 38%, Necator in 11%, Giardia in 18% and E. histolytica in 1%. In spite of the high prevalence of parasites, the general health of the children studied was remarkably good, and only 18 of the 1000 children were found to have a haemoglobin level below 10 g/dl.

Ascariasis↗