PubMed Health⌕ Search

Biomedical subjects

A Ranjan

Publications and source records attributed to A Ranjan.

At least 19 recordsLinked to original sources
PubMed2005

Visceral leishmaniasis (kala-azar)--the Bihar (India) perspective.

From a hospital-based surveillance carried out in Rajendra Memorial Research Institute of Medical Sciences, Patna, Bihar, India, the socio-economic, demographic and treatment response information of 737 patients admitted with visceral leishmaniasis (VL) during January 2001-December 2003, were analysed. The disease was two times higher in males than in females because of several factors including clothing pattern, sleeping habits and occupation. In Bihar, the second poorest state in India, poverty plays a major role in perpetuation of the disease, contributing to malnutrition, illiteracy (60%), and poor housing (82%). Further, presences of peri-domestic animal shelters around houses (63%) and vegetations (77%) facilitate breeding of sand fly vector. Clinical and laboratory characteristics were similar in the age groups <12 years and >12 years. The increasing unresponsiveness of VL patients to conventional anti-leishmanial drugs, e.g. sodium antimony gluconate (SAG) and pentamidine, has definitely posed a major therapeutic challenge in combating the disease. Amphotericin B, though costly, is highly effective. Miltefosine is a highly promising new oral drug for VL.

Adolescent↗
PubMed2005

Usefulness of the direct agglutination test in the early detection of subclinical Leishmania donovani infection: a community-based study.

The value of a direct agglutination test (DAT) in the detection of subclinical infections with Leishmania donovani has recently been investigated in the Indian state of Bihar, after the sensitivity and specificity of the test had been determined. When used to screen sera from 108 parasitologically confirmed cases of visceral leishmaniasis, 50 patients with active, non-leishmanial infection, and 641 healthy controls living close to, or distant from, an endemic area, the test was found to be 91.7% sensitive and 100% specific if a titre of 1:800 was used as the threshold for seropositivity. During a longitudinal clinical study in a rural, VL-endemic area of the Indian state of Bihar, the test was used, with 1:800 set as the threshold titre, to determine the baseline prevalence of infection with L. donovani among villagers who, though showing no symptoms of VL, had recently been febrile for at least 2 weeks. The 234 subjects of this study were either VL-case contacts [i.e. members of households in which there were active or cured VL cases (N=78)] or the members of control households with no cases or history of the disease (N=156). The results of DAT at the start of the study indicated that 49 (20.9%) of the subjects--29 (37.2%) of the VL-case contacts and 20 (12.8%) of the other subjects--were seropositive and therefore probably had subclinical infections with L. donovani. During the subsequent 9 months of follow-up, however, only eight of the subjects found seropositive at the start of the study--seven (24.1%) of the seropositive case contacts but only one (5.0%) of the other seropositives--developed symptomatic VL, all by month 6 of the follow-up. Compared with their neighbours, therefore, individuals who shared households with active or cured cases of VL appeared at greater risk not only of L. donovani infection (indicating focal transmission) but also of developing symptomatic disease once infected. Curiously, among the seropositive case contacts, those from the households that harboured active cases of VL at the baseline survey were less likely to develop symptomatic VL during the 9 months of follow-up than those from households that harboured only cured cases (18.8% v. 30.8%). The wide-spread use of DAT could allow the detection and early treatment of latent L. donovani infections and so contribute to the elimination of VL, at least as a public-health problem, from India.

Agglutination Tests↗
PubMed2004

Evaluation of cholinesterase level in an endemic population exposed to malathion suspension formulation as a vector control measure.

The manuscript describes a study on the blood cholinesterase (ChE) level in an exposed population at different interval of time after spraying with malathion suspension (SRES) use for kala-azar vector control in an endemic area of Bihar, India. The toxicity of a 5% malathion formulation in the form of a slow release emulsified suspension (SRES) was assessed by measuring serum ChE levels in spraymen and in the exposed population. The study showed a significant decrease in ChE levels in the spraymen (p < 0.01) after one week of spraying and in exposed population one week and one month after of spraying (p < 0.01), but was still within the normal range of ChE concentration, one year after spraying, the ChE concentration in the exposed population was the same as prior to spraying (p > 0.01). On no occasion was the decrease in ChE level alarming. A parallel examination of the clinical status also showed the absence of any over toxicity or any behavioural changes in the exposed population. Hence, it may be concluded that 5% malathion slow release formulation, SRES, is a safe insecticide for use as a vector control measure in endemic areas of kala-azar in Bihar, India so long as good personal protection for spraymen is provided to minimize absorption and it can substitute the presently used traditional DDT spray.

Animals↗
PubMed2004

Epidemiological, clinical & pharmacological study of antimony-resistant visceral leishmaniasis in Bihar, India.

BACKGROUND & OBJECTIVES: Sodium antimony gluconate (SAG) is reported to be losing its efficacy in Bihar as a first line drug for treatment of visceral leishmaniasis (VL). Concerned with the increasing incidence of antimony-resistant VL patients in Bihar, we undertook an epidemiological, clinical and pharmacological study to formulate a scientific basis for choosing a suitable first line drug for VL. METHODS: Consecutive, fresh and parasitologically confirmed patients of VL from different geographical areas of Bihar were considered for inclusion in the study. Parasites isolated from patients were tested in vitro to assess their response to sodium antimony gluconate (SAG) to 20 microg/ml, response to 20 mg/kg of SAG for 5 days in experimentally induced VL in BALB/c mice from those isolates, and response to SAG in patients treated with SAG for 28 days. Similarly response in culture (1 microg/ml) to amphotericin B (AMB) of all 282 isolates, (1 mg/kg body wt for 20 days) in patients and infected BALB/c mice (1 mg/kg body wt for 5 days) was determined. Antimony levels of plasma were determined at 2, 8 and 24 h after intramuscular injection of SAG. Patients unwilling for SAG treatment or relapsed after SAG treatment and withdrawn from SAG group because of toxicity were treated with AMB. Plasma antimony levels were estimated by atomic absorption spectrometer. RESULTS: Though antimony sensitive and resistant patient were distributed in all 14 districts of Bihar studied, there was a significant variation from district to district. Of the 123 patients included in the SAG treatment group, 19 were withdrawn due to development of toxicity and 2 died; 178 patients were treated with AMB. No patient in AMB group developed any toxicity or died. Only 47 (46%) of 102 patients, 106 (37.6%) of 282 infected macrophages, 90 (52.9%) of 170 experimental infections were cured with SAG. Mc Nemar's test on paired comparisons showed statistical significance difference (P<0.01) between infected macrophage and experimental infection. AMB cured all patients, infected mice and cleared parasites from all isolates. INTERPRETATION & CONCLUSION: Antimony resistant strains of L. donovani were wide spread over different geographical areas in Bihar. SAG cured lesser percentage of VL cases clinically compared to AMB and should be replaced by AMB as a first line drug.

Adult↗
PubMed2003

Two novel somatic mutations in the human interleukin 6 promoter region in a patient with sporadic breast cancer.

Two new single nucleotide mutations were observed within the promoter region of human interleukin-6 gene (IL-6) in the tumour sample of a patient with sporadic breast cancer, which was a somatic change. Both mutations, one at -125 (C > G) and the other at position -173 (G > T) from the translation start site, were transversions observed at new positions, not reported earlier. In addition to these two novel mutations in this patient, a known somatic polymorphism was also observed at position -174 (G > C) (from the transcription initiation site, redesignated as -236 from the translational initiation site as per the HUGO nomenclature). Further, a preliminary comparative analysis of the studied promoter region by the 'ConsInspector 3.0' program, where the mutated sequence (AF362378) was compared with the sequence existing in the database (Y00081), depicted the presence of the variations in putative binding sites for transcription factors such as glucocorticoid response element (GRE) and nuclear factor kappa-B (NFkappa-B), which could lead to differential expression of this gene.

Base Sequence↗
PubMed2001

Biochemical, biophysical, and functional characterization of bacterially expressed and refolded receptor binding domain of Plasmodium vivax duffy-binding protein.

Invasion of erythrocytes by malaria parasites is mediated by specific molecular interactions. Plasmodium vivax is completely dependent on interaction with the Duffy blood group antigen to invade human erythrocytes. The P. vivax Duffy-binding protein, which binds the Duffy antigen during invasion, belongs to a family of erythrocyte-binding proteins that also includes Plasmodium falciparum sialic acid binding protein and Plasmodium knowlesi Duffy binding protein. The receptor binding domains of these proteins lie in a conserved, N-terminal, cysteine-rich region, region II, found in each of these proteins. Here, we have expressed P. vivax region II (PvRII), the P. vivax Duffy binding domain, in Escherichia coli. Recombinant PvRII is incorrectly folded and accumulates in inclusion bodies. We have developed methods to refold and purify recombinant PvRII in its functional conformation. Biochemical, biophysical, and functional characterization confirms that recombinant PvRII is pure, homogeneous, and functionally active in that it binds Duffy-positive human erythrocytes with specificity. Refolded PvRII is highly immunogenic and elicits high titer antibodies that can inhibit binding of P. vivax Duffy-binding protein to erythrocytes, providing support for its development as a vaccine candidate for P. vivax malaria. Development of methods to produce functionally active recombinant PvRII is an important step for structural studies as well as vaccine development.

Amino Acid Sequence↗
PubMed2001

Neurocutaneous melanosis: a case of primary intracranial melanoma with metastasis.

Neurocutaneous melanosis is a rare disorder characterized by the presence of large or multiple congenital melanocytic naevi and benign or malignant pigment cell tumours of the leptomeninges. Distant metastasis is unusual in primary leptomeningeal/intracranial melanomas. We present the case history of an adult male who had multiple primary intracranial melanomas associated with neurocutaneous melanosis (naevus of Ota) in the ophthalmic division of the left trigeminal nerve. Excision of the intracranial tumours was carried out in two stages, but the patient died 2 days after the second operation. Autopsy showed multiple metastatic deposits in the liver. Symptoms and signs of raised intracranial pressure, the presence of Ota's naevus, and a dural-based mass or masses should alert the treating physician to suspect a primary leptomeningeal/intracranial melanoma.

Adult↗
PubMed2001

Seasonal and nocturnal landing/biting behaviour of Phlebotomus argentipes (Diptera: Psychodidae).

The nocturnal activity of Phlebotomus argentipes (Diptera: Psychodidae), the main vector of Leishmania donovani in India, was studied throughout a year, with monthly collections, between 18.00 and 06.00 hours, of the sandflies landing on 15 humans and 15 cows in the village of Bahapur, Patna district. The cattle appeared to be better as bait, since more than five female P. argentipes were caught on them for each one caught on the human bait. Overall, although P. argentipes were caught during each collection hour from 18.00--06.00 hours, the numbers caught landing/biting peaked at 23.00--24.00 hours. There were, however, slight seasonal variations in the timing of this peak in activity. The numbers of P. argentipes caught/collection night also varied with season, being significantly higher during the summer than during the rainy season or winter (P < 0.01 for each), and apparently inversely correlated with rainfall. Male P. argentipes were caught in much higher numbers than the females of this species, with female:male ratios of 1:8 for the flies caught on human bait and of 1:13 for those collected from cattle. If the probability of a female P. argentipes being infected with L. donovani does not vary with season, peak transmission of this parasite to humans probably occurs between February and May, at the middle of night.

Animals↗
PubMed2001

A randomized clinical trial of low dosage combination of pentamidine and allopurinol in the treatment of antimony unresponsive cases of visceral leishmaniasis.

OBJECTIVES: A randomized clinical trial of low dosage combination of pentamidine and allopurinol was carried out with objectives to assess the efficacy and toxicity as compared to full dosage of pentamidine in antimony unresponsive visceral leishmaniasis (VL) patients. METHODS: Using a randomized control clinical trial, a total of 158 antimony unresponsive patients of VL were randomly allocated into two treatment groups. Patients in one group (n=80) received half the dosage of pentamidine i.e. 2 mg/kg body weight by IM route on alternate day and allopurinol in dose of 15 mg/kg body weight in three divided dosages for 30 days; patients in the second group (n=78) received pentamidine in dose of 4 mg/kg body weight by IM route on alternate day for 15 injections in 30 days. The efficacy and safety of the two regimens were compared. RESULTS: Apparent cure i.e. clinical and pathological cure at the end of therapy, in 78 (97.5%) and 67 (86%), and ultimate cure i.e. clinical and parasitological cure at the end of follow-up of six months, in 73 (91.25%) and 58 (74.35%) patients was observed in the combination regimen and single regimen group respectively. The difference of the ultimate cure between two groups of the patients was statistically significant (p < 0.01). In single regimen group, 11 (14%) patients showed primary unresponsiveness (with no response during treatment) and nine (13%) relapse (after six months of follow-up) respectively, where as in combination regimen group, two (2.5%) patients showed primary unresponsiveness and five (6.4%) relapse respectively. By the end of the treatment, the incidence of injection-related toxicity, such as rigor and fever, was same in both groups. No hyperglycemia was observed in combination therapy probably due to reduced dose of pentamidine and three patients in single regimen developed hyperglycemia and one of them developed irreversible hyperglycemia. CONCLUSIONS: The study showed that the combination of pentamidine (half dose) and allopurinol is more effective in achieving ultimate cure with an added advantage of reduced toxicity in unresponsive cases as compared to full pentamidine dose.

Adolescent↗
PubMed2001

Effect of immunization with lipid associated polysaccharide antigen and anti CD-2 antibodies on class II MHC expression and cellular immune response in BALB/C mice infected with Leishmania donovani.

In a bid to characterize the antigens and immunization mechanisms which may be used to produce a protective response against L. donovani, role of lipid associated polysaccharide (LPS) antigen and whole antigen was evaluated. BALB/C mice were immunized with whole or LPS antigen in combination with one of three putative adjuvents (anti CD-2 antibody/FIA/0.85% Saline). LPS antigen emulsified in anti CD-2 antibody was found to induce significant antibodies in mice on day 28 against challenge with lethal dose of L. donovani. Immunoprophylactic properties of LPS and whole antigen was investigated on day 40 through cytokine elicitation (IL-2), MIF) in culture supernatants of spleen cells, but before that MHC-II expressed on macrophage was studied. The LPS antigen in combination with anti CD-2 antibody was found to be most immuno-reactive inducing higher MHC-II expression on macrophages which was associated with substantial rise in the level of MIF and IL-2. It coincided with decline in antibody titre in 100% mice immunized with LPS antigen while Leishmania injected as whole antigen failed to induce specific macrophage and T-cell response with all the above formulations. We surmise from our data that lipid associated polysaccharide antigen linked to anti CD-2 antibody has potential for eliciting protective immunity against Leishmania.

Animals↗
PubMed2000

Relevance of direct agglutination test in seroepidemiological survey of Kala-azar in epidemic foci of Bihar.

The performance of direct agglutination test (DAT) was evaluated under field conditions in three endemic districts of Bihar. In three villages of these districts, 197 households were surveyed with a population of 1167 individuals. Out of 1167 individuals, 603 were clinically examined for VL and blood samples of each examined individual were collected for DAT. The proportion of DAT positivity in both males (32.33%) and females (32.94%) was statistically not significant (p > 0.05). The proportion of DAT positivity in all age groups was observed to be similar (p > 0.05). The GMRT was observed highest in active VL cases. Out of 20 DAT positive individuals having fever, 5 were examined parasitologically (bone marrow aspiration) and in three cases positivity was observed. This showed the relevance of DAT in early diagnosis of visceral leishmaniasis and usefulness of DAT in field conditions.

Adolescent↗
PubMed1999

Mapping regions containing binding residues within functional domains of Plasmodium vivax and Plasmodium knowlesi erythrocyte-binding proteins.

Invasion of erythrocytes by malaria parasites is mediated by specific molecular interactions. Whereas Plasmodium vivax and Plasmodium knowlesi use the Duffy blood group antigen, Plasmodium falciparum uses sialic acid residues of glycophorin A as receptors to invade human erythrocytes. P. knowlesi uses the Duffy antigen as well as other receptors to invade rhesus erythrocytes by multiple pathways. Parasite ligands that bind these receptors belong to a family of erythrocyte-binding proteins (EBP). The EBP family includes the P. vivax and P. knowlesi Duffy-binding proteins, P. knowlesi beta and gamma proteins, which bind alternate receptors on rhesus erythrocytes, and P. falciparum erythrocyte-binding antigen (EBA-175), which binds sialic acid residues of human glycophorin A. Binding domains of each EBP lie in a conserved N-terminal cysteine-rich region, region II, which contains around 330 amino acids with 12 to 14 conserved cysteines. Regions containing binding residues have now been mapped within P. vivax and P. knowlesi beta region II. Chimeric domains containing P. vivax region II sequences fused to P. knowlesi beta region II sequences were expressed on the surface of COS cells and tested for binding to erythrocytes. Binding residues of P. vivax region II lie in a 170-aa stretch between cysteines 4 and 7, and binding residues of P. knowlesi beta region II lie in a 53-aa stretch between cysteines 4 and 5. Mapping regions responsible for receptor recognition is an important step toward understanding the structural basis for the interaction of these parasite ligands with host receptors.

Animals↗
PubMed1997

Involvement of host factors in transcription from baculovirus very late promoters -- a review.

The baculovirus expression vector system has emerged as the system of choice for the expression of a number of heterologous genes of both prokaryotic and eukaryotic origin. This system utilizes the baculovirus very late, hyperactive polyhedrin and p10 promoters to drive the transcription of foreign genes. Regulation of transcription from these promoters is presently not well understood even though a number of viral gene products that may be important for transcription have been identified. Fresh insight into host-virus interactions during baculovirus pathogenesis is now offered by the identification of insect host factors that interact with transcriptionally essential motifs of these promoters as well as cis-acting enhancer-like elements upstream from the promoter.

Base Sequence↗
PubMed1996

Expression and functional characterisation of the clpC gene of Mycobacterium leprae: ClpC protein elicits human antibody response.

This paper reports the expression of a previously described gene [Nath and Laal, Nucleic Acids Res. 18 (1990) 4935], currently identified as the clpC gene of Mycobacterium leprae, using an in vitro rabbit reticulocyte lysate-coupled transcription/translation system. The produced protein moved as a 95-kDa band on SDS-PAGE. An additional band of 79 kDa was seen which may have resulted from a GTG codon downstream to the initiating ATG in the clpC sequence. A threefold increase in synthesis of the 95-kDa protein was achieved by altering the translation codon context sequence of the ATG start codon. The ClpC (caseinolytic protease C) amino acid sequence, which contained two nucleotide-binding sites, exhibited in vitro ATP binding. Of functional significance was its immunoreactivity in human subjects with mycobacterial infection. Leprosy and tuberculosis patients with active disease had antibodies which recognised ClpC in dot ELISA.

Adenosine Triphosphate↗
PubMed1996

Symptomatic subdural hygroma as a complication of foramen magnum decompression for hindbrain herniation (Arnold-Chiari deformity).

Pseudomeningocele is a well known complication of foramen magnum decompression. Symptomatic subdural hygroma has not previously been described. We discuss a case of Arnold Chiari malformation type 1 in a 55-year-old Caucasian woman who underwent foramen magnum and upper cervical decompression and who developed a symptomatic subdural hygroma 2 weeks following surgery. This complication was most likely due to a technical error during surgery. It responded favourably to conservative therapy.

Arachnoid↗
PubMed1995

Influence of codon usage and translational initiation codon context in the AcNPV-based expression system: computer analysis using homologous and heterologous genes.

Codon usage by all the known gene sequences from Autographa californica nuclear polyhedrosis virus (AcNPV) was compared with that of firefly luciferase (luc) and the beta subunit of human chorionic gonadotropin (beta hCG) expressed to contrasting levels in the baculovirus system. The highly expressed luc gene showed a codon usage similar to AcNPV genes, as reflected by a very low D-squared statistic value (0.78) and a similar G/C usage (45%) at wobble positions. However, the underexpressed beta hCG gene displayed a high D-squared value (7.3) and G/C usage (82.5%) at the wobble base position. Alignment of the 20 nucleotides around the initiation codon of 23 AcNPV genes identified a novel consensus translation initiation sequence aag/ta/tat/aa/cAAaATGaa/ct/ag/aAan, which was quite different from the Kozak consensus sequence (GCC)GCCA/GCCATGG. An extension of these analyses to a sample of other heterologous genes overexpressed and underexpressed in BEVS suggested similar trends. These theoretical analyses have important implications for heterologous gene expression in this system.

Animals↗
PubMed1995

Intracerebellar melanotic schwannoma: a case report.

Neuro-axial melanotic schwannoma is a rare entity. We report the clinical, CT and pathological features of a solitary, cellular intracerebellar melanocytic schwannoma in a 65-year-old woman. The probable origin of this type of tumour is discussed.

Aged↗