Search PubMed⌕ Search

Biomedical subjects

D I Grove

Publications and source records attributed to D I Grove.

At least 91 records · Page 5Linked to original sources

Serum microfilarial antibody titres before and after treatment of bancroftian microfilaraemia with diethylcarbamazine.

Eight Filipino patients with Wuchereria bancrofti microfilaraemia were treated with diethylcarbamazine. The intensity of microfilaraemia and titre of microfilarial agglutinating antibodies were measured over the ensuing six weeks. Nuclepore filtration of blood indicated clearing of microfilaraemia in five patients and a reduction in numbers in the other three. Several patterns of antibody response were observed. Five patients had high initial antibody titres; they did not change significantly after diethylcarbamazine therapy. Antibody was not detectable before treatment in three patients; elimination of microfilaraemia was associated with the appearance of antibody in two of the subjects, while microfilariae were not totally cleared and antibodies never appeared in the third patient. This study confirms that diethylcarbamazine is not always successful in the treatment of bancroftian microfilaraemia. It is consistent with, but does not prove, the hypothesis that the presence or absence of microfilariae and microfilarial antibodies depends upon the relative release of microfilariae into the bloodstream and the rate of synthesis of microfilarial antibodies.

Antibodies↗

Transfer by serum and cells of resistance to infection with Strongyloides ratti in mice.

C57Bl/6 mice were infected with Strongyloides ratti. Susceptibility to infection was ascertained by quantifying the numbers of larvae in the faeces 1 week after infection. Resistance to infection was transferred by pooled immune serum and mesenteric lymph node (MLN) cells obtained 2 and 3 weeks after infection. There was no additive effect when immune serum and MLN cells were given together. Protection was not conferred by MLN cells 1, 4 or 6 weeks after infection nor by spleen cells taken 1--6 weeks after infection. There was, however, a mild non-specific reduction in larval excretion after transfer of either normal or immune spleen cells. These data indicate that both humoral and cell-mediated immune responses may confer resistance to infection in murine strongyloidiasis.

Animals↗

Strongyloidiasis in Allied ex-prisoners of war in south-east Asia.

One hundred and sixty ex-servicemen who had been prisoners of war in south-east Asia during 1942-5 were investigated for infection with Strongyloides stercoralis. Larvae were found in 44 (27.5%) of the men, who had therefore been infected for 34-37 years. Direct microscopy of the faeces was the most successful diagnostic method, giving a positive result in 37 cases (84%); multiple examinations were often necessary. Faecal culture was positive in 30 cases (68%), but examination of duodenal fluid obtained with the string test gave a positive result in only 17 (39%). The mean blood eosinophil count and mean serum IgE concentration were higher in the infected men, though normal values were often found in individual cases. Clinical manifestations of isolated strongyloides infection were analysed by comparing the infected men with control groups of ex-prisoners in south-east Asia without proved strongyloidiasis and ex-prisoners in Europe. Twenty-nine infected men (66%) complained of non-specific urticaria, and 13 (30%) had pathognomonic larva currens. Gastrointestinal symptoms significantly more common in the infected group were diarrhoea, indigestion, lower abdominal pain, pruritus ani, and weight loss (p <0.05-p <0.0005).The study group was thought to be reasonably representative of Allied ex-servicemen imprisoned in south-east Asia during the second world war. Probably there are many thousands of infected persons in several countries. The worm has an unusual ability to multiply, and larvae may spread throughout the body in immunosuppressed subjects.

Aged↗

Q fever.

Q fever is endemic throughout much of Australia and is most frequently seen in abattoir workers, farmers and veterinarians. Initially, there is a febrile, influenza-like illness. The infection is usually self-limited within several weeks, but rarely patients may develop infective endocarditis or hepatitis. The diagnosis is usually confirmed by finding risings titres of antibodies specific for C. burneti. The infection is not very responsive to treatment, but if tetracycline is administered early, the duration of fever is shortened.

Abattoirs↗

Scanning electron microscopy of the penetration of newborn mouse skin by Strongyloides ratti and Ancylostoma caninum larvae.

The scanning electron microscopical appearances of infective larvae of Strongyloides ratti and Ancylostoma caninum have been described. Particularly noteworthy was the tail of S. ratti which was found to have a distal aperture surrounded by a row of eight projections. The penetration of larvae through newborn mouse skin was investigated. S. ratti larvae forced its way rapidly and directly through the stratum corneum. No larvae of A. caninum were observed in stages of partial penetration but the occasional empty sheath was seen.

Ancylostoma↗

Immunosuppression in bancroftian filariasis.

Immunological function in Filipino patients with bancroftian filariasis, manifested as either asymptomatic microfilaraemia or chronic obstructive disease, was compared with that found in healthy control subjects living in the same area. As a group, patients with filariasis had raised serum IgG levels, impairment of antibody responses to tetanus and typhoid vaccines, and suppression of delayed hypersensitivity skin reactions to heterologous antigens. This immunosuppression in filariasis may result from antigenic competition and may contribute to the development of secondary infections.

Antibody Formation↗

Brugia malayi microfilaraemia in mice: a model for the study of the host response to microfilariae.

Microfilariae of Brugia malayi were obtained from the peritoneal cavities of infected gerbils and were then injected intravenously into mice. A sub-periodic, nocturnal microfilaraemia was produced. The level of microfilaraemia was proportional to the number of parasites injected, with approximately 1-3% of microfilariae being found in the peripheral circulation. The duration of microfilaraemia was proportional to the number of parasites injected; it subsided by 30 days after injection of 104 microfilariae but was still present at a low level 120 days after injection of 2 x 105 microfilariae. A transient splenomegaly developed after injection of microfilariae. Histopathological examination revealed large numbers of microfilariae free in the lumens of pulmonary small blood vessels and without any accompanying inflammatory reaction. Lesser numbers of microfilariae were seen in the cardiac blood and hepatic and renal blood vessels for the first few days after injection. There was cellular proliferation in the splenic white pulp and vascular congestion of the red pulp. Microfilariae labelled with 51Cr were injected intravenously; 57% of radioactivity was found in the lungs, 8.5% in the liver and 2.9% in the spleen. Mice developed immediate hypersensitivity reactions to B. malayi antigen by 4 weeks after injection, but Arthus and delayed hypersensitivity reactions were not seen at any time. when mice which had been injected 5 months previously were challenged with a 2nd injection of microfilariae, there was an accelerated clearance of parasites over 2 weeks and a marked peripheral blood eosinophilia developed. In contrast with natural infections, in which the continuous production of microfilariae complicates assessment, this model provides a system in which factors controlling the circulation of microfilariae in the bloodstream can be studied independently.

Animals↗

Bancroftian filariasis in a Philippine village: entomological findings.

Bancroftian filariasis in an isolated Philippine village has been intensively investigated; this paper reports the entomological findings. Surveys were carried out six months apart in the driest and wettest months. Significant transmission was demonstrated only during the wet season. Aedes poicillius was the major vector of Wuchereria bancrofti. Ae. poicilius accounted for 58% of larvae found in the axils of banana plants and 31% of those in abaca axils; negligible numbers of larvae of this species were found in pandanus and gabi axils. Mosquitoes were collected from indoor harbourages twice weekly for five weeks during the wet season; 615 mosquitoes were caught of which 80% were Ae. poicilius and 9% were Culex quinquefasciatus. 11% of the former and 13% of the latter contained filariae; whereas all stages of development were seen in Ae. poicilius, no development beyond the first stage was seen in Cx. quinquefasciatus. Human bait trapping was used for 110 manhours; 371 mosquitoes were caught of which 58% were Ae. poicilius and 24% were Culex summorosus. Filarial larvae were seen only in Ae. poicilius; 3.7% of mosquitoes were positive and all stages of filarial development were seen. The mean landing/biting rate between 1900 and 0500 hours was 3.37 mosquitoes per man-hour with a maximum of almost seven mosquitoes per man-hour at midnight. Overall, 2.26% of vectors collected in the human studies were infective. There was an average of 3.38 third-stage larvae per infective mosquito. The efficiency of transmision was estimated as 6.1 x 10-5, or one new case of microfilaraemia for every 16, 400 bites by infective mosquitoes in the village population. In contrast to the human studies, large numbers of mosquitoes were caught by animal bait trapping in both the wet and dry seasons. The distribution of mosquito species was similar in the two seasons. Ae. poicillius represented only 1.0-1.5% of all mosquitoes seen. No filarial larvae were seen. It was concluded that transmission of filariasis in the village was inefficient and postulates were advanced to explain the increased intensity and severity of filariasis inmen as compared to women.

Animals↗

The Schistosoma japonicum egg granuloma. II. Cellular composition, granuloma size, and immunologic concomitants.

Studies of granulomatous hypersensitivity to Schistosoma japonicum eggs were performed at various time periods up to 20 wk after the induction of light infections in mice. Cell populations which were determined in granulomas isolated from the livers revealed a maximum in the total number of cells at 6 wk with a decline of 36% by 20 wk. Large mononuclear cells were predominant at all time periods, with eosinophils being the second most common cell. Measurements of granuloma diameters around single viable eggs in the livers also revealed peak size at 6 wk with a decline of 51% between 16 and 24 wk. Immunodiffusion analysis demonstrated the presence of precipitating antibodies as early as 7 wk after infection. Investigations of lymphocyte blastogenesis revealed a profound depression in response to T-cell mitogens by 8 wk of infection. Studies of footpad swelling to soluble S. japonicum egg antigens revealed massive immediate reactions starting at 6 wk. but no delayed reactivity over a period from 3 to 20 wk. All of these results are related to differences in the biology of S. japonicum in comparison with S. mansoni with respect to the earlier onset of egg production, the much larger numbers of eggs produced, and the possibility of differences in the antigens emitted by the eggs.

Animals↗

Serological diagnosis of bancroftian and malayan filariasis.

A study was undertaken to define the sensitivity and specificity of serological tests in bancroftian and malayan filariasis and correlate the findings with clinical disease. Sera were collected from subjects on three different islands in the Philippines: one endemic for bancroftian filariasis, another endemic for malayan filariasis and the third without endemic filariasis. Antibodies were measured, using rugia malayi as the source of antigen. Antibodies against adult worms measured by indirect immunofluorescence were found at a titer of 1:8 or greater in all patients with bancroftian or malayan filariasis but not in the control subjects. There was no relationship of antibody titer to clinical status. Antibodies against microfilariae were measured by indirect immunofluorescence and microfilarial agglutination. A high correlation was observed between the two methods. These antibodies were found in only one quarter, approximately, of patients with filariasis. Microfilarial antibodies were found more commonly in those patients with chronic lymphatic obstruction. It is concluded that measurement of antibodies to adult worms is a useful indicator of infection while microfilarial antibodies are correlated with disease.

Agglutination Tests↗