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Biomedical subjects

S C Das

Publications and source records attributed to S C Das.

At least 37 records · Page 2Linked to original sources
PubMed1997

Role of Anopheles culicifacies during an outbreak of malaria in Gorubandha P.H.C., Assam.

Entomological investigation during an outbreak of malaria in Gorubandha PHC in Sonitpur district revealed unusually high density of Anopheles culicifacies followed by An.minimus. Parity rates of both the species were very high, 65% and 62.2% respectively. An. culicifacies was incriminated as malaria vector. Sporozoite rate recorded was 0.63%. Both the species were found susceptible to DDT. This substantiates the epidemiological observation which yielded 98% Plasmodium falciparum malaria out of 35.2% malaria positive cases. Incrimination of An. culicifacies means adding one more malaria vector to this region.

Animals↗
PubMed1996

Evaluation of Methoprene (Altosid) and Diflubenzuron (Dimilin) for control of mosquito breeding in Tezpur (Assam).

Insect growth regulators (IGRs) namely, Isopropyl (E-E)-(RS)-11-methoxy-3,7,11-trimethyldodeca-2, 4-dinoate (Methoprene) and 1-(4-cyclophenyl)-3-(2,6-diflerobenzoyl) urea (Diflubenzuron) were evaluated against mosquito larvae in laboratory as well as in different breeding habitats in Tezpur, Assam. LC90 values of diflubenzuron against Culex quinquefasciatus and Aedes albopictus were 0.0022 and 0.0027 ppm respectively, while it was 0.0027 and 0.0022 ppm respectively in case of methoprene. However, LC50 values of both the IGRs were almost same in case of Ae. albopictus and Cx. quinquefasciatus (varies between 0.0009 and 0.0011 ppm). In case of methoprene, maximum mortality was observed in pupal stage though the exposure was given in all the cases to the III instar larvae. Field trials were conducted in cemented drains, small ponds and ditches. At 0.2 ppm (0.020 kg/ha) both diflubenzuron and methoprene were found to eliminate 92-96 per cent Culex and Anopheles larvae. Methoprene and diflubenzuron were found equally effective for control of mosquito breeding in different breeding habitats and provide better efficacy than conventional larvicides and biocides.

Aedes↗
PubMed1995

Endemic goiter in the Jos Plateau region of northern Nigeria.

This study is an endemic goiter survey of 3476 school children in 13 Local Government Councils (LGCs) and 1004 subjects in a whole community of one LGC, Plateau State, Northern Nigeria, to determine the prevalence of goiter as well as to identify some of the etiological agents involved. Results of the survey showed that the disease is highly endemic in the area with prevalence varying in places from 1 to 23% of these subjects. Females showed a markedly higher prevalence of goiter. Analysis of 729 urine samples indicated that iodine excretion ranged from 3.5 to 1.3 microgram/dl (32-154 microgram/g creatinine) and was similar to that in iodine deficient areas in the world, but no relation was observed between the prevalence of goiter and urinary iodine. Urinary thiocyanate levels were less than 0.5 mg/dl, suggesting that the role of the thiocyanate as a goitrogen is not important in the region. Thyroid hormone parameters in village subjects with goiter were similar to those in goiter endemia except serum thyroxine (T4). An interesting result found in village subjects was very high serum thyroxine binding globulin, which leads to an increase in serum T4. This study indicated that Northern Nigeria is an area of endemic goiter. Although some areas in Plateau State are iodine deficient zones, we could not conclude that the etiology of endemic goiter in this area is associated with iodine deficiency. There may be an interplay of multiple factors of etiological importance.

Adolescent↗
PubMed1994

Thyroid function profile and differential serum lipid and lipoproteins in Africans with endemic goitre.

Serum total thyroxine (TT4), total triiodothyronine (TT3), thyrotrophine (TSH), thyroxine binding globulin (TBG), total lipids, triglycerides, total cholesterol, beta lipoprotein and beta lipoprotein cholesterol level were measured in 68 goitrous subjects and 4 agoitrous cretins by the techniques based on enzyme immunoassay (ELISA) (for thyroid parameters) and enzyme substrate principle (for lipid and lipoproteins) using commercial test kits (Boehringer Mannheim, W. Germany) and the results were matched with those derived from 59 clinically normal control subjects. The mean values of serum TT3, TBG, TSH and T3/T4 ratio showed positive correlations with the goitre size (r > 0.8, P < 0.005) while mean serum TT4 was negatively correlated (r > -0.9, P < 0.005). Typical biochemical features of hypothyroidism on serum lipid and lipoprotein profile were seen throughout, the changes being more marked in cretins. However, the serum lipid and lipoproteins were also, to some extent, found to be positively related to the thyroid size. In addition, a number of patients also showed variations in the serum lipid and lipoprotein levels appropriate to their compensated thyroid functional status in endemic goitre (as reflected by low TT4, raised TT3 and raised T3/T4 quotients).

Adolescent↗
PubMed1994

Immunogenic activity of viral polypeptides of an Indian isolate of infectious bursal disease virus.

An Indian isolate of infectious bursal disease virus, i.e. IBDV-P/AD/81, was analysed for immunogenic activity of its structural polypeptides. Virus was purified from infected bursal homogenate by sucrose density gradient centrifugation. It showed five different structural polypeptides of 75.8, 45, 40.7, 33.1 and 27 kDa molecular weights in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Anti infectious bursal disease virus (IBDV) antibodies were tested using enzyme-linked immunosorbent assay (ELISA) and neutralization test (NT). Polypeptide 40.7 kDa (VP2) was known to have neutralizing epitopes. However, polyclonal anti VP2 failed to neutralize the virus. It was interpreted that VP2 had labile neutralizing epitopes which get altered confirmationally by SDS. Surprisingly, polyclonal anti 33.1 kDa (VP3) had mild neutralizing activity.

Animals↗
PubMed1994

Laboratory and field evaluation of Bacillus thuringiensis and B. sphaericus against mosquito larvae.

Laboratory and field trials were carried out with two formulations of Bacillus thuringiensis and four strains of Bacillus sphaericus (B 42, B 64, B 87 and B 33) against mosquito larvae in different breeding habitats of Tezpur, Assam. LC90 of B. thuringiensis var israelensis (formulation Teknar) against Ae. albopictus, Cx. quinquefasciatus and Cx. gelidus were recorded as 0.443, 0.453 and 2.15 ppm respectively and LC90 of B. thuringiensis (Deltox: VCRC B-17) against Ae. albopictus, Cx. quinquefasciatus, Cx. gelidus and Cx. malayi were 8.414, 11.22, 5.24 and 6.761 ppm respectively. LC90 of B. sphaericus strains B 42, B 64, B 87 and B 33 against Cx. quinquefasciatus were 0.055, 0.115, 0.046 and 0.257 ppm respectively. At the dosage of 1 l/ha 87 per cent mortality was achieved after 24 hrs with Bti and it increased to 90-95 per cent at 1.5 l/ha. In polluted cemented drains 93-97 per cent kill of Cx. quinquefasciatus was observed at 2.5 l/ha. Out of four strains of B. sphaericus evaluated, strain B 87 was found to be the most effective as 87-96 per cent kill was achieved with only 0.1 kg/ha for Cx. quinquefasciatus, Cx. vishnui and A. vagus. For others 0.2 kg/ha dosage, eliminated 96-100 per cent Cx. vishnui gr. for B 42, 92-93 per cent for B 64 and 90-93 per cent for B 33 strain.

Aedes↗
PubMed1993

The "feto-maternal" thyroid function interrelationships in an iodine-deficient region in Africa--the role of T3 in possible fetal defence.

The thyroid status was investigated in 26 pregnant African women at term delivery in an iodine-deficient region (Jengere) of Nigeria, West Africa including the measurement of serum T4, T3, TSH, thyroxine binding capacity, TBG, free thyroxine index (FT4I) and the results were matched with those obtained in a corresponding group of 46 women at delivery in Jos, the non-iodine-deficient region which was used as a control. Corresponding cord-blood samples were obtained from all the neonates of the two groups. Twenty-three urinary samples in the former and 14 in the latter group were analysed for iodide levels to ascertain the degree of iodine deficiency. The results demonstrate that compared to the values seen in the Jos group the maternal serum T4, T3 and FT4I levels were significantly reduced in the iodine-deficient group, while TSH, TBG and thyroxine binding capacity were elevated. Cord serum samples showed a corresponding fall in T4 and FT4I levels in the group from the iodine-deficient region, while the T3 levels were significantly elevated with a concurrent significant rise in TSH and TBG levels. Significant correlations were found between the maternal and cord serum T4, TSH, TBG, thyroxine binding capacity and FT4I levels, but not T3. From these findings we suggest that fetal T3 plays an important defensive role against the danger of long-standing environmental iodine deficiency.

Adolescent↗
PubMed1993

Aberrations in serum proteins and thyroid size in Nigerians on the Jos Plateau and their relation to thyrometabolic function.

Controlled serum protein and thyroid function studies were carried out among 208 African patients with endemic goitre. The changes seen in the serum protein constituents were studied and evaluated in relation to thyroid hormone levels, goitre grade and the clinical state of the patient. Mean serum TBG and thyroglobulin values rose sharply in the early phase of goitre, and remained elevated throughout. Although the mean serum total T4 was statistically and significantly higher in endemic goitre compared with the normal subjects (t = 3.72. P = 0.005), the free thyroxine index was significantly lower and serum T4 fell progressively (r = 0.975) with increasing thyroid grade. In contrast, mean serum T3 rose continuously (r = 0.910) but appeared inflated due to a proportionate increase in TBG in several cases, giving a misleading picture of T3--thyrotoxicosis in otherwise clinically normal subjects. An increase in T3/T4 ratio and consequently in thyroid function, therefore occurs with advancing thyroid size. Inconsistent binding of T4 to TBG causes wide variations in thyroxine index. Mean serum albumin and betalipoprotein appeared inversely related to thyroid function. These changes imply that in order to evaluate a patient with endemic goitre accurately a detailed biochemical investigated of the thyroid may be necessary.

Blood Proteins↗
PubMed1993

Persistence of leech repellents on cloth.

Trials on persistence of repellent properties of N, N-diethyl phenyl acetamide (DEPA), N,N-diethyl-m-toluamide (DEET), 3acetyl2(2-6-dimethyl-5-heptenyl)oxazolidine(Citronyl) , dimethyl phthalate (DMP) and N-benzoyl piperidine (NBP) on cloth were conducted against land leeches in evergreen rain and deciduous forests of Assam. Results obtained were compared with volatile oil of Zanthoxylum armatum DC. syn. Z. alatum Roxb (Timur) to evaluate its efficacy as leech repellent. DEPA and DEET were found to be the best. Timur oil was at par with Citronyl and exhibited better results than DMP and NBP.

Acetamides↗
PubMed1991

Anticonceptive and estrogenic effects of a seed extract of Ricinus communis var. minor.

An ether-soluble fraction of a methanol extract of Ricinus communis var. minor seeds administered subcutaneously to adult female rats and rabbits at doses up to 1.2 g/kg and 600 mg/kg, respectively, in divided doses showed anti-implantation and anticonceptive activities. Laparotomy performed on Day 10 and Day 15 of pregnancy on mated female rats and rabbits treated with the extract did not reveal any uterine implantation sites. The animals were protected against pregnancy for over three gestation periods and among those that later delivered, there was no evidence of abnormality in the pups. In ovariectomized young female rats as well as in immature mice, the extract dose-dependently increased uterine wet weight. Furthermore, the extract induced premature opening of the vagina, increased the number of epithelial cells and cornified cells and decreased the leucocyte number in the vaginal smear. The estrogen-like activities exhibited by the extract were dose-dependent and the anticonceptive effect may be due at least in part to such estrogenic action.

Animals↗
PubMed1991

Mosquito survey in Tripura.

Vector survey carried out in Tripura revealed the presence of 17 species of anophelines with a density of 92.39 per trap night. Major malaria vector encountered was Anopheles philippinensis which formed 30% of the total collection and is exophagic in nature. Another efficient malaria vector An. minimus which formed 5% of the total collection prevails equally both indoors and outdoors. The high parity rate of An. philippinensis (59%) and An. minimus (63.9%) gives a strong indication about their vectorial status in Tripura.

Animals↗
PubMed1990

Central cretinism in four successive siblings.

A study of four successive siblings, age 9, 12, 14 and 16 years with cretinism associated with congenitial central hypothyroidism (central cretinism), born to a mother in the endemic goitre region of the Jos Plateau, Nigeria, is presented. Biochemically, the defects were characterized by abnormally low basal thyroxine, triiodothyronine and thyroid stimulating hormone, as well as refractory TSH response to thyrotrophin releasing hormone and gross hyperlipidaemia. Clinically, the intellectual, physical and neurological impairment varied from moderate in the youngest to very severe in the oldest. Contrasting clinical pictures of cretinism, which appeared related to age and previous treatment were found with a spectrum ranging from predominantly myxoedematous in the youngest to predominantly neurological in the 16 year old male. Response to adequate treatment was dramatic, with restoration of severe gait disturbance occurring almost completely, but the imprints of thyroid hormone deficiency on mental defects and intellectual performance remained almost unaltered. The parents and two older sisters were normal with normal thyroid function.

Adolescent↗
PubMed1990

Active malaria transmission in South Mizoram.

Anopheles dirus was incriminated as malaria vector with 1.12% sporozoite rate in Tlabong (Demagiri) subdivision, Mizoram. High parity rate of A. dirus (33.69%) and A. minimus (52.87%) further confirmed their vectorial status. Both the vectors were found highly susceptible to 4% DDT.

Animals↗
PubMed1989

Serum and thyroid tissue lipids in patients with thyroid tumors in euthyroidism.

Plasma lipids of 24 euthyroid subjects with thyroid adenoma and non-toxic primary differentiated thyroid carcinoma (papillary and follicular types) were assessed and compared with a similar investigation conducted on 20 normal subjects. A parallel study with thyroid tumor tissues examined the lipid changes which occurred in the same group of patients. These were compared with the picture seen in 5 normal thyroids. The investigations examined the changes in total lipids; total, free and esterified cholesterol; total phospholipids; lecithin; cephalin and sphingomyelin; triglycerides and free fatty acids in both serum and thyroid tissue. Compared with normal subjects, the serum lipids were almost identical except for the concentration of free fatty acids which showed significantly lower values in the group with neoplastic changes. Tissue analysis of the cancerous thyroid however revealed a marked rise in virtually all lipid fractions but the cholesterol seemed to dominate the picture. The differential studies of total phospholipids for thyroid tissue membrane lipids further revealed a significant increase in the lecithin and sphingomyelin components of total phospholipids as well as the esterified cholesterol fraction in thyroid carcinoma. The changes in thyrophospholipids were more marked in females normal thyroids than males. An attempt has been made through evaluation of the results derived from differential lipid studies to elucidate the role of some of the various fractions determined and the possible effect of the changes described on thyroid hormone metabolism.

Adenocarcinoma↗
PubMed1989

Studies on malaria and filariasis vectors in Kamorta and Great Nicobar Islands.

A total of 1401 adult mosquitoes mainly dominated by Anopheles sundaicus (40.18%) and Culex quinquefasciatus (57.31%) were collected from Kamorta and Great Nicobar Islands. It was revealed from human bait collection that both species prevailed almost all through the night (density 8.1/man hour) with a peak around midnight. Mixed breeding of A. sundaicus with A. vagus, Cx. quinquefasciatus, Cx. bitaeniorhynchus and Cx. tritaeniorhynchus was observed at many places. Adult A. sundaicus were found highly susceptible to DDT and larvae to Temephos (Abate). Cx. quinquefasciatus was resistant to DDT (31% mortality). High parity of A. sundaicus (40.42%) is an indication of the vectorial potential of this species to sustain malaria transmission in these islands.

Animals↗