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Biomedical subjects

P K Kar

Publications and source records attributed to P K Kar.

At least 19 recordsLinked to original sources
PubMed2005

Genetic variability and genetic structure of wild and semi-domestic populations of tasar silkworm (Antheraea mylitta ) ecorace Daba as revealed through ISSR markers.

The genetic diversity in the wild and semi-domestic populations of Daba ecorace of Antheraea mylitta was studied to ascertain the distribution of variability within and among populations of semi-domestic bivoltine (DB), trivoltine (DT) and nature grown wild populations (DN) with inter-simple sequence repeat (ISSR) markers. A total of 138 markers were produced among 56 individuals of the three populations, of which 98% were polymorphic. For the individual populations, the percentage polymorphism was 58.69, 52.9 and 77.54 for DB, DT and DN, respectively. Average number of observed (1.791+/- 0.408) and effective alleles (1.389+/-0.348) was also high in the wild populations in comparison to the bivoltine and trivoltine semi-domestic populations. Genetic diversity (H(t)) in DB, DT and DN was 0.180+/- 0.033, 0.153+/- 0.032 and 0.235+/- 0.033, respectively and within-population genetic diversity (H(s)) ranged from 0.166 to 0.259 with a mean of 0.189. Mean gene differentiation (G(ST)) was found to be 0.25. Shanon's diversity index was 0.278, 0.237 and 0.361 for DB, DT and DN and overall it was 0.391. Gene flow (N(m)) among the populations was 1.509. The dendrogram produced by UPGMA with Dice's genetic distance matrices resulted in the formation of three major clusters separating the three populations. Considerable intra- and inter-population variability is found in all three populations. The population structure analysis further suggests that the semi-domestic populations of Daba ecorace are at the threshold of differentiating themselves. The high genetic variability present within wild Daba population of A. mylitta is of much importance for conservation as well as utilization in systematic breeding program.

Alleles↗
PubMed2001

NO nerves in trematodes, too! NADPH-diaphorase activity in adult Fasciolopsis buski.

The free radical nitric oxide (NO) is a unique molecule with an avidity to react with other molecules and is known to function as a neuronal messenger. This nitrergic transmitter with diverse functions in signal transduction, being a gas, is not stored in synaptic vesicles but is generated in various neuronal cells by a family of nitric oxide synthases (NOSs). The NADPH-d histochemical reaction is regarded as a selective marker for NOS in the neuronal tissue. With histochemical detection of NADPH-d, the presence of NOS is demonstrated in the digenetic trematode, Fasciolopsis buski. Strong NADPH-d staining was observed in the neuronal cell bodies in the two cerebral ganglia, the brain commissure and the nerve fibers in the main nerve cords. NADPH-d staining was also detectable in the innervation of the pharynx, the cirrus sac and the ventral sucker besides being observable sporadically in the nerve tributaries in the general parenchyma. NO released by the whole worm kept in PBS at 37 degrees C could also be measured biochemically. The NOS activity was assayed in the whole worm homogenate and also in the tissue homogenate containing only the anterior pre-acetabular part of the parasite body. The presence of NOS in this digenean parasite confirms that a nitrergic innervation occurs in the trematode group also as in other groups of exclusively parasitic helminths and that NO represents an old signal molecule in evolutionary scale.

Animals↗
PubMed2000

Chloroquine and desethylchloroquine concentrations in blood cells and plasma from Indian patients infected with sensitive or resistant Plasmodium falciparum.

The sensitivities of 61 Indian cases of Plasmodium falciparum malaria to chloroquine (CQ) were investigated using in-vitro and in-vivo methods. Concentrations of CQ and desethylchloroquine (DCQ) in blood cells and plasma from CQ-sensitive and -resistant cases were determined 2 and 7 days after initiation of treatment, by HPLC. On day 2, the mean CQ concentrations in the samples collected from the sensitive cases were higher than those in the samples from the resistant patients, in plasma (0.47 v. 0.32 microgram/ml; P < 0.02) and particularly in the blood cells (1.51 v. 0.46 micrograms/ml; P < 0.001). By day 7, however, the CQ concentrations in the two groups were similar. Although, on day 2, the mean ratio of the CQ to DCQ concentrations was significantly higher in the blood cells from the sensitive group than in those from the resistant cases (P < 0.01), the CQ/DCQ ratios for the plasma were similar for the two groups. Similarly, the mean ratio between the blood-cell concentration of CQ on day 2 and the concurrent plasma concentration (BPr) was also relatively high in the sensitive group (P < 0.001).

Adult↗
PubMed2000

Investigation of malaria prevalence at National Thermal Power Corporation, Shaktinagar, Sonbhadra District (Uttar Pradesh), India.

Malaria in industrial complexes is promoted by extensive mosquitogenic potential generated by excavations and importation of parasite through migratory labor. The National Thermal Power Corporation (NTPC), Shaktinagar, Sonbhadra district was surveyed for malariogenic conditions from 1994 to 1996. The major mosquito breeding sites were drains, storm-water drains, lakes, outside tanks, overhead tanks, sluice-valve chambers, ornamental tanks, wells, pit wells and water reservoirs, etc. Anopheles culicifacies was the major vector of malaria in this area. Sibling species identification of An. culicifacies revealed that species C predominated during the transmission season and responsible to transmit malaria. Insecticide susceptibility tests against An. culicifacies sl showed that An.culicifacies population was 100% susceptible to malathion, fenitrothorn and deltamethrin while it was found 44% resistant to DDT. The malaria cases recorded in 1994, 1995 and 1996 were 847, 590 and 409 respectively. In vitro study on P. falciparum cases showed that 41, 70, 50% of the isolates tested were resistant to chloroquine in 1994, 1995 and 1996 respectively while an in vivo follow-up study showed 20-30% P. falciparum cases resistant to chloroquine. An integrated approach involving alternate vector control measures along with judicious use of insecticides has been suggested to bring down malaria in industrial complexes.

Animals↗
PubMed1997

In-vivo and in-vitro sensitivity of Plasmodium falciparum to chloroquine in Chennai (Tamil Nadu), India.

In-vitro and in-vivo susceptibility of Plasmodium falciparum to chloroquine were conducted at Chennai city, India. Eighteen (60%) out of 30 cases showed resistance in in-vitro study. EC50 of resistant and sensitive cases were 0.40 and 0.24 mumol chloroquine/l blood respectively, while EC90 were 2.64 and 0.84 mumol chloroquine/l blood respectively. In-vivo tests identified 24 cases (40%) as resistant (23 RI and 1 RII) and 36 (60%) as sensitive out of 60 cases. Eight isolates which were found resistant with in-vitro tests showed sensitive behaviour to chloroquine treatment assessed by in-vivo studies.

Adolescent↗
PubMed1996

High-performance liquid chromatographic determination of primaquine and carboxyprimaquine concentrations in plasma and blood cells in Plasmodium vivax malaria cases following chronic dosage with primaquine.

A reversed-phase HPLC method using acetonitrile-methanol-1 M perchloric acid-water (30:9:1:95, v/v) at a flow-rate of 1.5 ml/min on a mu-Bondapak C18 column with UV detection at 254 nm was developed for the separation of primaquine, its major metabolite carboxyprimaquine and other metabolites such as N-acetylprimaquine, 4-hydroxyprimaquine, 5-hydroxyprimaquine, 5-hydroxy-6-methoxyprimaquine, demethylprimaquine and 6-methoxyprimaquine, and also other antimalarials. The calibration graphs were linear in the range 0.025-100 micrograms/ml for primaquine and 4-1000 micrograms/ml for carboxyprimaquine. The within-day and day-to-day coefficients of variation averaged 3.65 and 6.95%, respectively, for primaquine and 3.0 and 7.52%, respectively for carboxyprimaquine in plasma. The extraction recoveries for primaquine and carboxyprimaquine were 89 and 83%, respectively. The mean carboxyprimaquine concentration was much higher in plasma and blood cells of Plasmodium vivax patients than that in plasma from healthy subjects. The carboxyprimaquine level was also higher in blood cells than plasma whereas the primaquine concentration was the same in both cases.

Adolescent↗
PubMed1996

Chloroquine resistant Plasmodium vivax malaria in India.

In India, 1.2-1.5 million new cases of Plasmodium vivax occur each year. These cases are successfully treated with 600 mg chloroquine (adult dose). We report the results of malaria treatment of a 13-year-old girl from the Indian Oil Corporation (IOC), Mathura, India who contracted P. vivax infection. The infection failed to respond to 2 cycles of standard chloroquine therapy. The concentrations of chloroquine were monitored with high performance liquid chromatography (HPLC). The plasma and whole blood chloroquine concentrations were 260 and 106 micrograms/l respectively, while a 15 micrograms/l plasma concentration is considered lethal to P. vivax. Resistance in P. vivax to chloroquine was found at the IOC, Mathura.

Adolescent↗
PubMed1994

A clinicopathological study of multidrug therapy in borderline tuberculoid leprosy.

A study was undertaken to evaluate the efficacy of multidrug therapy as per WHO recommendation in 50 fresh cases (46 males and 4 females) suffering from borderline tuberculoid leprosy. All were given multidrug therapy consisting of rifampicin 600 mg once a month and dapsone 100 mg daily for 6 months. At the end of 6 months all were evaluated clinically and histopathological examinations of the lesions were studied. The lesions were still active in 60% of patients clinically; 32% cases receiving multidrug therapy had shown marked improvement. Histologically lymphocytic infiltration in skin still persisted in all the slides examined and nerve infiltration was still present in 68% of cases at the end of 6 months after receiving multidrug therapy. The study shows that treatment with multidrug regimen for 6 months may not be sufficient to treat borderline tuberculoid leprosy cases.

Adolescent↗
PubMed1994

Evaluation of psoralen with solar ultraviolet light (puvasol) and adjunctive topical tar therapy in psoriasis.

Fifty patients having psoriasis were studied with a view to assess the efficacy of 'puvasol' (Oral psoralen with sun-rays exposure) alone and in combination with topical tar therapy and were placed in 2 groups, each group being consisted of 25 patients. At the end of 8 weeks, out of 25 patients (Group 1) receiving 'Puvasol' in combination with topital tar therapy 15 patients (60%) showed complete clearance, marked improvement of lesions were seen in 4 cases (16%) and deterioration in one case (4%). Out of 25 patients (Group I) receiving 'Puvasol' alone 8 cases (32%) showed complete clearance of lesions and 11 patients (44%) showed marked im-provement of lesions. It is found that topical tar therapy when used as an adjunct to 'Puvasol' was more effective than 'Puvasol' alone.

Administration, Cutaneous↗
PubMed1993

Prevalence of lymphatic nodule in a bancroftian endemic population.

Prevalence and clinical manifestation of lymphatic nodule in natural course of bancroftian filariasis was evaluated in a representative population of 2837 of a defined endemic community of Orissa. Detailed clinical and parasitological examination of study subjects revealed high disease (35.6%) and mf rate (15.8%) and mean microfilariae density (GM: 15.3 +/- 5.1 per 60 mm3 of blood) in the community. Lymphatic filarial nodule was manifested in 216 (7.6%) subjects in different spectrum of filarial infection including endemic normals and asymptomatic mf carriers. Significant proportion of cases with acute filarial disease in the community manifested nodule. Significant proportion of cases with nodule had microfilaraemia (33.3%) as compared to that of community. However highest frequency of nodule was observed amongst microfilaraemics with lowest density of microfilaraemia in the community (P < 0.05.). This possibly indicates microfilariae clearance from circulation as a consequence of death of adult parasite. The above observations suggest that lymphatic nodules may manifest as an early and/or the only clinical sign of bancroftian filariasis. This might have been mediated through either the attempt of the immuno-competent host to kill the adult parasite in a similar fashion that is effected through DEC or by death of the mature parasite in its natural process of attrition.

Acute Disease↗
PubMed1993

In-vivo and in-vitro sensitivity of Plasmodium falciparum to chloroquine at Indian Oil Corporation, Mathura (U.P.).

In vivo and in vitro susceptibility of Plasmodium falciparum to chloroquine were conducted at Indian Oil Corporation (IOC), Mathura, India. 18 out of 31 cases showed resistance [minimum inhibitory concentration (MIC) 8 pmol] in in vitro study. EC50 and EC90 values estimated from log-probit analysis for resistant isolates were 0.66 and 1.44 microM/litre, and for sensitive isolates 0.28 and 0.96 microM/litre blood respectively. In vivo tests identified 13 cases (40.62%) as resistant and 19 cases (59.73%) as sensitive out of 32 cases. All the cases belonged to IOC, Mathura complex, or its vicinity.

Animals↗
PubMed1993

Clinical filarial disease in two ethnic endemic communities of Orissa, India.

To evaluate the possible role of ethnicity in susceptibility to filarial infection, a comparative study of the prevalence of filarial infection was initiated in an endemic village inhabited by two ethnic populations of mainlanders and tribals. An age and sex matched sampled population of 591 mainlanders and 106 tribals was studied by detailed clinical and parasitological (60 mm3 blood) examinations. Sera collected from both population groups (26 each) matched for clinical stage of infection were analysed for humoral immune responses such as antifilarial IgG, circulating filarial antigen and immune complex level. The overall prevalences of clinical disease and infection in both mainlanders (34.18 and 14.4%) and tribals (25.47 and 17.9%) were comparable. However, both annual average adenolymphangitic attack rate (1.77 year-1) and the prevalence of chronic filarial disease (22.6%) amongst tribals were significantly lower. No true elephantiasis was observed in tribals. No significant difference was observed in their humoral immune response, although the antifilarial antibody of IgG class in all stages of filarial infection was lower in tribals than in mainlanders. The results did not reveal any difference in susceptibility to filarial infection in the ethnic groups. The paucity of progressive lesions observed in tribals possibly reflects a difference in the anatomy of lymphatics or genetic or immunoregulatory mechanisms, that needs further study.

Acute Disease↗
PubMed1992

Tissue tonometry: a useful tool for assessing filarial lymphedema.

A tissue tonometer was used to assess peripheral lymphedema in patients with filariasis in a Bancroftian endemic community. Matched populations of 34 patients with Grade II and 29 patients with Grade III unilateral lower limb edema and 26 healthy subjects were assessed for leg tissue compressibility and circumference. Tonometry was performed at three fixed points on the leg using three weight levels (70, 140, and 210 gms). The mean value of compressibility for each weight level and points measured in the edematous leg were significantly less compared with the contralateral non-edematous leg in the filarial patients and the legs of healthy subjects. Patients with Grade III lymphedema were more resistant to compression than Grade II patients throughout the leg but especially at the foot. The least mean square analyses of circumference and compressibility differential values of edematous compared with non-edematous legs revealed a positive correlation at the foot in Grade II and the proximal and distal parts of Grade III lymphedema; moreover, the slopes were significantly different from zero. These findings support progressive tissue changes of edema and fibrosis first in the foot and later in the more proximal portions of the leg which correspond to progressive volume expansion with protein-rich fluid. Tissue tonometry appears to be a sensitive measure for assessing progression of both edema and fibroplasia in patients with peripheral lymphedema associated with filariasis, and, therefore, may be a useful tool to measure the efficacy of drugs commonly used to treat this condition.

Acute Disease↗
PubMed1990

Peripheral lymph node tuberculosis: a review of 80 cases.

One hundred and ninety-two patients with peripheral lymphadenopathy were screened and 80 patients with tubercular lymphadenitis were studied. Their ages ranged from 1 to 65 years; most were younger than 30 years and there was a slight female preponderance (1.2:1). Seventy per cent of patients were of low socioeconomic status. Of the 80 patients, 56 had affected cervical nodes, seven had inguinal nodes, five had axillary nodes and 12 had multiple sites of lymph node involvement. All had enlarged nodes which were matted in 44 cases and discrete in 18 cases, while the rest had either an abscess or a discharging sinus. Fifty-nine cases (74 per cent) showed a positive Mantoux test and four cases (5 per cent) had associated pulmonary tuberculosis. Fine needle aspiration cytology gave a positive diagnosis in 66 cases (83 per cent). Fifty-two cases showed a positive culture for Mycobacterium tuberculosis of human type in Lowenstein-Jensen medium. Short-term chemotherapy (9 months) consisting of rifampicin, isoniazid and ethambutol gave an excellent result. Surgery was not required in any of the cases.

Adolescent↗
PubMed1990

Isolation, partial purification and pharmacodynamics of a slow contractile substance in the venom sac extract of the wasp Vespa cincta Fabr.

The venom of V. cincta contains acetylcholine (ACh), histamine and 5-hydroxytryptamine (5-HT). Blockers of these agonists did not block completely the hypotensive and smooth muscle contractile activity of venom. On smooth muscle, there was a residual slow contraction. The active substance which produced this slow contraction was separated by solvent extraction, gel filtration and TLC. The purified material (which has been provisionally designated "Vecikinin") lowered cat, rat and guinea pig blood pressure, increased amplitude of cardiac contraction, and increased capillary permeability. Vecikinin contracted several smooth muscle preparations (rat uterus, rat ascending colon, guinea pig ileum, guinea pig colon and rat ileum), while relaxing rat duodenum. Its contractile activity was not lost on boiling, but acid or alkali-boiling reduced its contractile activity. It was inactivated on incubation with chymotrypsin and carboxypeptidase but not with trypsin, pepsin or leucine aminopeptidase. It is a peptide, appears to be of low molecular weight, and could be distinguished from substance P, angiotensin, bradykinin and hornet or wasp kinin.

Animals↗