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Biomedical subjects

B M Sharma

Publications and source records attributed to B M Sharma.

At least 19 recordsLinked to original sources
PubMed2005

Impact of land use practices on faunal abundance, nutrient dynamics and biochemical properties of desert pedoecosystem.

Increased dependence of resource-poor rural communities on soils of low inherent fertility are the major problem of desert agroecosystem. Agrisilviculture practices may help to conserve the soil biota for maintaining essential soil properties and processes in harsh climate. Therefore, the impacts of different land use systems on faunal density, nutrient dynamics and biochemical properties of soil were studied in agrisilviculture system of Indian desert. The selected fields had trees (Zizyphus mauritiana, Prosopis cineraria, Acacia nilotica) and crops (Cuminum cyminum, Brassica nigra, Triticum aestivum) in different combinations. Populations of Acari, Myriapoda, Coleoptera, Collembola, other soil arthropods and total soil fauna showed significant changes with respect to different land use practices and tree species, indicating a strong relation between above and below ground biodiversity. The Coleoptera exhibited greatest association with all agrisilviculture fields. The Z. mauritiana system indicated highest facilitative effects (RTE value) on all groups of soil fauna. Soil temperature, moisture, organic carbon, nitrate- and ammonical-nitrogen, available phosphorus, soil respiration and dehydrogenase activity were greater under tree than that of tree plus cropping system. It showed accumulation of nitrate-nitrogen in tree field and more utilization by crops in cultivated lands. Positive and significant correlation among organic carbon, nitrate- and ammonical-nitrogen, phosphorus, soil respiration and dehydrogenase activity clearly reflects increase in soil nutrients with the increase in microbial and other biotic activity. P. cineraria field was the best pedoecosystem, while C. cyminum was the best winter crop for cultivation in desert agroforestry system for soil biological health and soil sustainability. The increase in organic carbon, soil nutrients and microbial activity is associated with the increase in soil faunal population which reflect role of soil fauna in fertility building. This suggests that strategies may be developed for nurturing fertility-building soil fauna and managing degraded pedoecosystem in desert just by adopting suitable agricultural practices.

Agriculture↗
PubMed2005

Effects of of habitats and pesticides on aerobic capacity and survival of soil fauna.

OBJECTIVE: Faunal health is largely dependent on their soil environment and available litter quality. So the effects of different soil habitats and pesticides on citrate synthase (CS) activity of soil fauna and its population were studied. METHODS: The soil animals were collected from different pedoecosystems for habitat study. Whereas Vigna radiata based system was selected for pesticidal observations. The field was divided into five equal plots for control and treatment of gamma-BHC, quinalphos, carbaryl and cypermethrin. Soil fauna was collected by quadrat method and extracted by Tullgren funnel. Individuals of a species having similar sizes were collected for the estimation of CS activity. They were homogenized and fractions were obtained by differential centrifugation. The activity of CS was assayed spectrophotometrically. RESULTS: Citrate synthase (CS) activity of beetle (Rasphytus fregi), woodlouse (Porcellio laevis) and centipede (Scolopendra morsitans) varied significantly with respect to changes in different soil habitats. Though the CS activity of R. fregi, P. laevis, and S. morsitans differed among themselves but the highest activity of CS in these animals was in V. radiata and lowest in A. nilotica based pedoecosystem. The aerobic capacity of centipede was maximum followed by woodlouse and beetle. The treatment of gamma-BHC, quinalphos, carbaryl and cypermethrin significantly reduced the CS activity of these animals. Gamma-BHC showed maximum reduction in CS activity indicating highly toxic effect of organochlorine on aerobic metabolism of soil fauna. However, minimum reduction was observed in response to carbaryl (in beetle) or cypermethrin (in woodlouse/centipede) leading to impairment of aerobic capacity. The differences in pesticide effects might be assigned to the differences in chemical nature of pesticides and their interactions with below-ground fauna. Treatment of gamma-BHC and quinalphos reduced the population of Acari, Coleoptera, Collembola, other arthropods as well as total soil fauna. Acari was least affected by gamma-BHC and maximally affected (72%) in response to quinalphos. The effect of gamma-BHC was fairly similar on Coleoptera, Collembola, other arthropod and total soil fauna suggesting almost similar sensitivity to this pesticide. Likewise, quinalphos was similarly effective on Collemobola and other soil arthropods. Application of carbaryl decreased Acari and Coleoptera population but increased Collembola, other arthropods and total faunal populations. However, application of cypermethrin significantly reduced the population of Acari, Coleoptera, Collembola and total soil fauna and increased the population of other soil arthropods. In both the cases, acarine population was least affected. CONCLUSION: The observations show the habitat-specific variation in aerobic capacity of soil fauna. However, pesticide-dependent loss in population might be due to impairment of aerobic capacity of soil inhabiting animals in desert.

Animals↗
PubMed2005

Temperature related seasonal changes in Golgi complex of brain, heart and intestine of a teleost.

Impact of temperature related seasonal changes in density of Golgi complex were studied in brain, heart and intestine of the freshwater catfish, Clarias batrachus (Linnaeus). The density of Golgi complex was more in these organs of the fish acclimatized to a lower temperature (20 degrees C) than that to a higher temperature (29 degrees C). This suggests that lower temperature induces secretory activity in cells to cope up with the changes in surrounding environment. It could be a kind of histophysiological adaptation in poikilothermic animal.

Acclimatization↗
PubMed1996

Epithelial adherence of Candida albicans is enhanced by passage through rat small intestine.

Seven Candida albicans isolates (four from patients with diarrhoea and three from healthy persons) underwent two passages through rat ileal loop (RIL) to see the effect of consecutive passages on the adherence to rat intestinal epithelium. The isolates from patients with diarrhoea showed a significant enhancement in adherence after the first passage (1.95 x 10(4) cfu/cm2 versus 3.67 x 10(4) cfu/cm2). There was no further increase between the first passage (3.67 x 10(4) cfu/cm2) and the second one (3.61 x 10(4) cfu/cm2). A similar pattern was observed with the three nondiarrhoeal isolates. Animal passage of this fungus probably leads to better interactions between the cell surfaces causing the enhanced adherence.

Animals↗
PubMed1981

Study of dermatomycoses.

555 clinically suspected cases of dermatomycoses were studied for causative fungi and their detailed clinical manifestations. The fungi were demonstrated on routine KOH mount and/or by culture in 464 cases (83.6%). Tinea corporis was the predominant fungal infection (30.6%) and T. rubrum was the main etiologic agent. Favus (T. schoenleini) was found only in cases from Jammu and Kashmir valleys. There was a high incidence of tinea capitis among children. Trichophyton tonsurans was isolated in cases of tinea corporis, tinea cruris, and tinea pedis. Trichophyton ferrugineum and T. verrucosum were isolated from cases of tinea capitis; and Microsporum gypseum was isolated from tinea cruris infections.

Adolescent↗