Search PubMed⌕ Search

Biomedical subjects

R Reuben

Publications and source records attributed to R Reuben.

At least 37 records · Page 2Linked to original sources
PubMed1993

Women and malaria--special risks and appropriate control strategy.

This paper reviews the factors which make non-immune pregnant women particularly vulnerable to falciparum malaria and examines the problems of adequately protecting them in relation to current control strategies. Women are most at risk in areas of high and continuous transmission, particularly during their first pregnancy, and also under conditions of unstable malaria which do not permit immunity to develop. Chemoprophylaxis is recommended for pregnant women in holoendemic and hyperendemic areas in Africa and Papua New Guinea. Chloroquine is safe, but drug resistance problems are beginning to limit its utility. Distribution is a formidable problem in rural areas with a poorly developed health care infrastructure, and research studies reveal widespread ignorance and lack of motivation. In countries in which primary health care systems are fairly well developed, and where malaria transmission is relatively less intense, the emphasis is on early diagnosis and treatment of cases. The assumption is made that women and men have equal access to medical facilities. The preponderance of reported cases among adolescent and adult males in some areas has been attributed solely to the well-known greater occupational risks in some traditionally male activities. Two recent studies, however, suggest that underprivileged women, weighed down by domestic chores, do not readily attend clinics at some distance from home, and therefore are liable to be missed in passive surveillance. It is essential that services within the village should be strengthened, but there are problems in implementation. Lacunae in existing knowledge are discussed.

Adolescent↗
PubMed1992

Evaluation of neem, Azadirachta indica, with and without water management, for the control of culicine mosquito larvae in rice-fields.

Applications of neem, Azadirachta indica (Meliaceae), to rice-fields were evaluated with the dual objective of controlling the culicine mosquito vectors of Japanese encephalitis virus (JEV) and enhancing the grain yield. Since crude neem products deteriorate under improper storage conditions, a laboratory bioassay was developed to screen neem cake powder against mosquito larvae, Culex quinquefasciatus. Only samples of neem giving over 90% bioassay mortality were used in field trials. When good quality neem cake powder was applied at the dose of 500 kg/ha, either alone or coated over urea, there was a striking reduction in the abundance of late instar culicine larvae and pupae. Only fourteen pupae were obtained over a period of 13 weeks in neem cake powder treated plots, and four in those treated with neem coated urea, compared with 101 in control plots. Both treatments were significantly less than the control, but on par with one another. In another field trial, neem cake coated urea was tested at 500 and 250 kg neem/ha in combination with water management practices. No reduction in efficacy was noted at the lower dose. Larval abundance in plots under water management alone did not differ significantly from the controls, but was significantly reduced when water management was combined with neem products. Two stable formulations, 'Neemrich-I' (lipid rich) and 'Neemrich-II' (azadirachtin rich), also gave good suppression of immature culicines. All the treatments with neem also gave higher grain yield than the control.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Mosquito blood feeding patterns as a factor in the epidemiology of Japanese encephalitis in southern India.

Determinations were made of the source of 16,330 bloodmeals from 10 species of Culex mosquitoes, including recognized vectors of Japanese encephalitis (JE) virus, in two epidemiologically distinct areas in southern India. In Madurai, where cases occurred sporadically and pigs were reared only in some villages, Cx. tritaeniorhynchus, Cx. pseudovishnui, and Cx. vishnui had fed predominantly on cattle (89.2-91%), but less frequently on humans (2.1-6.2%) and on pigs and ardeid birds (0-0.1%). In Nallur, which was endemic for JE and had a large pig population, 4.4-5.4% of the feedings were on these hosts. Cattle feedings accounted for 84.6-88% of the total feedings, human feedings for 2.4-6.2%, but there were no ardeid-positive feedings. Culex tritaeniorhynchus and Cx. vishnui showed a marked increase in the proportion of human feedings during the hot season, due to increased availability of humans sleeping outdoors to mainly exophagic mosquitoes. Feeding indices were corrected for spatial and temporal concurrence of hosts in each season, but these factors were found to require further elucidation. Discrepancies in the relative abundance of vectors as monitored by two different methods are discussed in the light of these observations.

Animals↗
PubMed1991

Evaluation of the water fern Azolla microphylla for mosquito population management in the rice-land agro-ecosystem of south India.

The floating water fern Azolla microphylla Kaulfess was evaluated as a biocontrol agent against mosquitoes breeding in rice fields in Tamil Nadu, South India. Anopheles subpictus Grassi, Culex pseudovishnui Colless and Culex tritaeniorhynchus Giles were the predominant species of mosquitoes, with peak densities of late instar larvae and pupae occurring during the second week after transplantation of rice seedlings of short-term (c. 80 days from transplantation to harvest) or medium-term (c. 95 days) varieties. Immature mosquito populations were reduced by mats of Azolla microphylla covering more than 80% of the water surface. However, since 80% coverage by Azolla was achieved only 13-14 days after rice transplantation, its usefulness for mosquito control was limited. Azolla may have a greater potential in an integrated control programme, or in areas where long-term varieties of rice are predominantly grown.

Agriculture↗
PubMed1991

Field efficacy of "Mosbar" mosquito repellent soap against vectors of bancroftian filariasis and Japanese encephalitis in southern India.

Deet-permethrin "Mosbar" soap was field tested for repellency against mosquitoes by volunteers in urban and rural localities in southern India. Eighty-nine to 100% reduction in man-vector contact was recorded for 8 mosquito species, including Culex quinquefasciatus and recognized vectors of Japanese encephalitis. The soap was highly acceptable to the community.

Adolescent↗
PubMed1991

Evaluation of a microgel droplet formulation of Bacillus sphaericus 1593 M (Biocide-S) for control of mosquito larvae in rice fields in southern India.

A new microgel droplet formulation of Bacillus sphaericus 1593 M (Biocide-S) was tested at 2 rates against culicine vectors of Japanese encephalitis and Anopheles subpictus. A single application just after transplantation of rice seedlings prevented the buildup of anopheline as well as culicine populations, and gave 83-100% reduction of pupal density at the lower rate (2.2 kg/ha) and 87-100% reduction at the higher dosage (4.3 kg/ha) for at least 5 weeks. During the last 3 wk before harvest, density was naturally very low and the efficacy of the treatment could not be assessed. This formulation has a potential for control of riceland mosquitoes, but a suitable delivery system is required before it can be considered for practical control.

Agriculture↗
PubMed1990

Space-spraying with malathion as a supplementary measure for operational malaria control.

Entomological studies showed that due to outdoor resting by the vector Anopheles culicifacies as well as poor spray coverage, indoor residual spraying with malathion was ineffective in malarious villages of the Thenpennai riverine tract in Tamil Nadu. Over a 4 yr period during which residual spraying was supplemented with ground applications of malathion space spraying, the slide positivity among patients with fever fell from 21.04 to 1.1 per cent. In mass blood surveys 0.7 per cent persons surveyed at the beginning of the study were positive for the malarial parasite, but no positives were detected in the last survey, in 1984. There was a rising trend in malaria incidence in riverine villages outside the programme.

Animals↗
PubMed1989

Ultra low volume (ULV) malathion application as a supplementary malaria control measure in two villages of South Arcot district, Tamil Nadu.

Ultra low volume (ULV) ground application of technical malathion as a supplementary malaria control measure was carried out in two riverine villages of South Arcot district, Tamil Nadu which had high persistent transmission since 1975. Malaria incidence was reduced to one fifth in villages under ULV malathion as against a 50% drop in the control village. The cost of ULV spray alone came to Rs. 1.07 per capita per year. ULV can be an effective supplementary measure in rural areas with specific problems.

Animals↗
PubMed1987

Intraglomerular T cells and monocytes in nephritis: study with monoclonal antibodies.

Intraglomerular T cells, monocytes, total leucocytes and other mononuclear subsets were sought in renal biopsies from patients with glomerulonephritis, using monoclonal antibodies and immunoperoxidase techniques. Twenty-four biopsies with no significant glomerular proliferation on optical microscopy, thirty-two with only endocapillary hypercellularity, and twenty-one with extra capillary crescentic glomerular disease were studied. Few intra-glomerular leucocytes were seen in the non-proliferative group. In contrast, when compared with this group, biopsies with glomerular hypercellularity and particularly those with crescents showed increased numbers of intra-glomerular total leucocytes and monocytes/macrophages, as well as an excess of T lymphocytes and T cytotoxic/suppressor cells; T helper/inducer lymphocytes were significantly increased only in the crescentic group. Only small numbers of B lymphocytes and NK cells were found in all groups. The numbers of total glomerular T-cells and monocytes per glomerular cross section were highly correlated in the crescentic group. Only idiopathic IgA nephropathy failed to show a significant increase in the numbers of intra-glomerular leucocytes, in comparison with the non-proliferative group, Henoch-Schönlein purpura biopsies in contrast had an excess of both monocytes and T cell subsets. The finding of T lymphocytes as well as monocytes in glomeruli of proliferative nephritis suggests that cellular immune mechanisms may play a role in their pathogenesis, especially when crescents are present.

Antibodies, Monoclonal↗
PubMed1987

Abnormal podocyte CR-1 expression in glomerular diseases: association with glomerular cell proliferation and monocyte infiltration.

The expression of CR-1 complement receptors on glomerular epithelial cells, was studied in 77 renal biopsies from patients with (74) or without (3) glomerular diseases, employing an anti-CR-1 monoclonal antibody, and an indirect immunoperoxidase technique. Four patterns of CR-1 expression were recognised: normal (18); generally decreased (6); focal/segmental partial loss (44); and complete loss (9). Normal expression was detected in all three biopsies with non-glomerular diseases, and in glomerular diseases with normal glomeruli on light microscopy, but also in several glomerulonephritic biopsies (13), including diffuse proliferative lupus nephritis (1 of 7) and idiopathic membranous nephritis (5 of 14). However, the majority of biopsies from patients with glomerular diseases showed abnormal CR-1 expression (59 of 74), most evident in proliferative biopsies (43 of 49), with or without crescent formation (respectively, 18 of 20 and 25 of 29). Complete loss of CR-1 expression was almost restricted to crescentic biopsies (8 of 9). The abnormal CR-1 expression was unrelated to the presence of capillary immune deposits of Ig or C. More intraglomerular monocytes, assessed by monoclonal antibodies, were encountered in glomerulonephritic biopsies with partial CR-1 loss (median 6.2, P less than 0.05) or complete loss (median 14, P less than 0.03), than in biopsies with normal receptor expression (median 1.4). Thus, changes in glomerular CR-1 expression are frequently seen in many glomerular diseases and are associated with glomerular proliferative changes and monocyte infiltration, but not with the presence of capillary immune deposits.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Monoclonal↗
PubMed1985

Glomerular thrombi in renal allografts associated with cyclosporin treatment.

We have found glomerular capillary thrombi or afferent arteriolar thrombosis in eight renal biopsy specimens from seven renal allograft recipients. All patients were receiving cyclosporin and prednisolone. Biopsies were performed either routinely one and four weeks after transplantation or during periods of renal dysfunction. None of the patients whose biopsy material contained glomerular thrombi was considered, in retrospect, to have been undergoing rejection at the time of biopsy. Thrombi consisted of finely granular material partially obstructing glomerular capillaries. By light microscopy the staining characteristics of the thrombi were compatible with platelet-fibrin aggregates, and this was confirmed by immunoperoxidase examination. Such thrombi have not previously been seen in biopsy material from patients treated with prednisolone and azathioprine, except rarely associated with acute vascular injection. In none of these patients was there haematological evidence of the haemolytic uraemic syndrome as has been reported in bone marrow recipients treated with cyclosporin.

Adult↗
PubMed1985

Glomerular C3b receptor loss in renal allografts.

There is almost no data from the glomeruli of allografted kidneys with respect to changes in the CR-1 (C3b) receptor expressed on glomerular podocytes. We studied 22 renal graft biopsies from rejecting and stable allografts, using a panel of monoclonal antibodies. We found that the CR-1 expression was decreased in a focal and segmental fashion in some biopsies, particularly in rejecting kidneys. These changes correlated with the intensity of glomerular mononuclear cell infiltration, but in contrast no correlation was seen with peripheral capillary wall deposition of complement (C3). Thus, some active process is occurring in the glomeruli of rejecting grafts which affects the expression of the CR-1 receptor.

Graft Rejection↗
PubMed1985

Interstitial foam cells in the nephrotic syndrome belong to the monocyte/macrophage lineage.

Interstitial foam cells are occasionally seen in patients with the nephrotic syndrome. In a group of patients with the nephrotic syndrome we were able to demonstrate that these cells express markers characteristic of the monocyte/macrophage lineage. Their presence was related to the previous duration of proteinuria, but they had no apparent influence on the subsequent evolution of renal function. The mechanisms leading to their presence are unknown.

Adult↗