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Biomedical subjects

P K Gupta

Publications and source records attributed to P K Gupta.

At least 19 recordsLinked to original sources
PubMed2006

Imaging growth dynamics of tumour spheroids using optical coherence tomography.

Optical coherence tomography (OCT) was used to monitor the dynamics of tumour spheroid formation by the hanging drop method. In contrast to microscopy, the estimates obtained using OCT for the volume of the spheroid, were consistent with the measured changes in cell number as a function of time. The OCT images also revealed heterogeneous structures in the spheroids of approximately 200 microm diameter. These corresponded to the necrotic regions identified by fluorescence of propidium iodide stained cells.

Cell Count↗
PubMed2006

Multi-class classification algorithm for optical diagnosis of oral cancer.

We report development of a direct multi-class spectroscopic diagnostic algorithm for discrimination of high-grade cancerous tissue sites from low-grade as well as precancerous and normal squamous tissue sites of human oral cavity. The algorithm was developed making use of the recently formulated theory of total principal component regression (TPCR). The in vivo autofluorescence spectral data acquired from patients screened for neoplasm of oral cavity at the Government Cancer Hospital, Indore, was used to train and validate the algorithm. The diagnostic algorithm based on TPCR was found to provide satisfactory performance in classifying the tissue sites in four different classes - high-grade squamous cell carcinoma, low-grade squamous cell carcinoma, leukoplakia, and normal squamous tissue. The classification accuracy for these four classes was observed to be approximately 94%, 100%, 100% and 91% for the training data set (based on leave-one-out cross-validation), and was approximately 90%, 90%, 85% and 88%, respectively for the corresponding classes for the independent validation data set.

Adult↗
PubMed2006

Acquired von Willebrand's disease associated with gastrointestinal angiodysplasia: a case report.

Acquired von Willebrand syndrome (AVWS) is a rare and probably underestimated bleeding disorder which mimics most of the clinical symptoms and laboratory features of hereditary von Willebrand disease (VWD) in patients devoid of both personal and family history of bleeding diathesis. In this study, we present a case of 55 yrs male patient, presented with gastrointestinal bleeds since three years, diagnosed to have AVWS with inhibitors. From this study it is concluded that AVWS is rare and it is important to diagnose this bleeding disorder so that appropriate treatment with plasmapheresis and IV:Ig can effectively correct the haemostatic defect and manage severe bleeding in these patients.

Angiodysplasia↗
PubMed2006

A DNA vaccine that encodes rabies virus glycoprotein lacking transmembrane domain enhances antibody response but not protection.

Rabies virus (RV) glycoprotein (gp) consists of three domains: cytoplasmic, transmembrane and ectodomain. It occurs in a complete, membrane-bound form within the infected cell, but it is released from them in a deleted, secreted form lacking the transmembrane domain. This study was performed to test the importance of the transmembrane domain for the capability of the RV gp gene, introduced into mice via a recombinant plasmid (DNA vaccine), to induce immune response and protection against challenge. Although the antibody response to the secreted form of gp was higher than that to complete gp, the protective efficacy of the respective DNA vaccine against challenge was not better than that of the DNA vaccine inducing complete gp. This indicates that the transmembrane domain of RV gp is important for generating protection against rabies and should be present in RV DNA vaccines.

Animals↗
PubMed2006

Role of gel based technique for Coomb's test.

The direct (DAT) and indirect antiglobulin tests (IAT) are one of the most important diagnostic tools used in the investigation of immune mediated disorders. Recently, transfusion laboratories have seen the introduction of column technology in the form of the gel technology (GT). Aim of this study is to compare the conventional tube tests (CTT) and the GT for Coomb's test and to evaluate their sensitivity and specificity. 1656 samples were included in this study, in which 1054 samples were subjected to IAT and 602 samples were subjected to DAT Of the 602 samples tested for DAT, 587 (97.5%) showed concordant DAT results. DAT by the GT could detect 8.6% positivity as compared to 6.1% by CTT. The sensitivity and specificity of the GT was 100% and 97.3% respectively and its negative predictive value was 100%. Among the 1054 samples for IAT, 1041 (98. 8%) showed concordant results. The IAT by the GT showed 6.6% positivity as compared to 5.4% positivity by CTT The sensitivity, specificity and the positive and negative predictive value were 100%, 97.7%, 81.4% and 100% respectively. In conclusion, the GT is a better alternative to the CTT for both DAT and IAT. The GT is highly recommended to be implemented as a routine method of testing in all zonal / regional blood transfusion centers.

Anemia, Hemolytic, Autoimmune↗
PubMed2006

Is seroprevalence of HTLV-I/II among blood donors in India relevant?

Human T-cell lymphotropic virus type I/II (HTLV-I/II) is associated with certain hematologic and neurologic disorders. Seroprevalence studies demonstrate that the distribution of HTLV-I/II is heterogeneous worldwide and not specific to one region. Because blood is one of the major routes of transmission of the virus, blood banks of several countries routinely screen all blood donations for HTLV-I/II. The aim of the present study was to assess the seroprevalence rate of HTLV-I/II antibodies among Indian blood donors and to confirm the positive rates by polymerase chain reaction (PCR). Between Jan 2004 to May 2005, consecutive blood samples of 10,000 blood donors were collected at the blood bank of Armed Forces Medical College, Pune. The samples were screened for HTLV-I/II by enzyme-linked immunosorbent assay (ELISA) method. Screening resulted in 18 (0.18%) positive samples, of which 14 (77.8%) samples were also positive by PCR. The prevalence of HTLV-I/II carriers in India seems to be negligible and is not a major public health hazard. Hence, routine screening of Indian blood donors for antibody to HTLV-I/II is not warranted due to its low prevalence in India.

Blood Donors↗
PubMed2005

Mapping of a major QTL for pre-harvest sprouting tolerance on chromosome 3A in bread wheat.

Quantitative trait loci (QTL) analysis was conducted for pre-harvest sprouting tolerance (PHST) in bread wheat for a solitary chromosome 3A, which was shown to be important for this trait in earlier studies. An inter-varietal mapping population in the form of recombinant inbred lines (RILs) developed from a cross between SPR8198 (a PHS tolerant genotype) and HD2329 (a PHS susceptible cultivar) was used for this purpose. The parents and the RIL population were grown in six different environments and the data on PHS were collected in each case. A framework linkage map of chromosome 3A with 13 markers was prepared and used for QTL analysis. A major QTL (QPhs.ccsu-3A.1) was detected on 3AL at a genetic distance of approximately 183 cM from centromere, the length of the map being 279.1 cM. The QTL explained 24.68% to 35.21% variation in individual environments and 78.03% of the variation across the environments (pooled data). The results of the present study are significant on two counts. Firstly, the detected QTL is a major QTL, explaining up to 78.03% of the variation and, secondly, the QTL showed up in all the six environments and also with the pooled data, which is rather rare in QTL analysis. The positive additive effects in the present study suggest that a superior allele of the QTL is available in the superior parent (SPR8198), which can be used for marker-aided selection for the transfer of this QTL allele to obtain PHS-tolerant progeny. It has also been shown that the red-coloured grain of PHS tolerant parent is not associated with the QTL for PHST identified during the present study, suggesting that PHS tolerant white-grained cultivars can be developed.

Chromosome Mapping↗
PubMed2005

N2 laser excited autofluorescence spectroscopy of formalin-fixed human breast tissue.

The paper reports results of an in vitro study on autofluorescence spectroscopy of fresh and formalin-fixed human breast tissue samples to investigate the effect of formalin fixation on the measured autofluorescence spectra. It also explores the applicability of the approach in discriminating cancerous from the uninvolved sites of the formalin-fixed breast tissues based on their autofluorescence spectra. A probability-based diagnostic algorithm, making use of the theory of relevance vector machine (RVM), a powerful recent approach for statistical pattern recognition, was developed for that purpose. The algorithm provided sensitivity values of up to 97% and specificity values of up to 100% towards cancer for both the independent validation data set as well as for the training data set based on leave-one-out cross-validation. These results suggest that autofluorescence spectroscopy may prove to be a valuable additional in vitro diagnostic modality in clinical pathology setting for discriminating cancerous tissue sites from normal sites.

Algorithms↗
PubMed2005

Immunotherapeutic effects of mangiferin mediated by the inhibition of oxidative stress to activated lymphocytes, neutrophils and macrophages.

The effect of mangiferin, a naturally occurring xanthone glucoside on cyclophosphamide-induced immunotoxicity and its mode of action in the immune system were investigated. To induce immunotoxicity, adult male Wistar rats were injected weekly with cyclophosphamide intraperitoneally at 100 mg/kg bodyweight. Mangiferin was injected intraperitoneally at 10 and 20 mg/kg daily for 14 days. Levamisole (3 mg/kg, i.p., daily for 14 days), a known immunostimulant that acts in immunosuppressive conditions was used as a standard drug. The effect of mangiferin on the primary immune response to ovalbumin (200 microg/rat, s.c.) was assessed at weekly intervals by measuring the serum ovalbumin-specific IgM levels. The organ weights and cellularity of spleen, thymus and bone marrow, haematology, T and B cell-dependent mitogen stimulation of splenocytes were assessed for the cellular response. Oxidative changes in lymphocytes, neutrophils and macrophages were measured at the end of the study. As well, the in vitro effect of mangiferin on cytotoxicity caused by H2O2 in primary lymphocytes was studied. The decrease in the lymphoid organ weights, cellular responses and antigen-specific IgM levels by cyclophosphamide treatment were significantly increased by repeated intraperitoneal administration of mangiferin. The enhanced lipid peroxidation and decreased catalase and superoxide dismutase activities found in lymphocytes, polymorphonuclear cells (PMN) and macrophages from cyclophosphamide treated rats were significantly ameliorated in mangiferin treated groups. The tissue injury caused by cyclophosphamide treatment was significantly suppressed by mangiferin as shown by the decrease in serum creatine phosphokinase (CPK) activity. In vitro experiments showed that pretreatment of lymphocytes with mangiferin protected from the toxicity induced by H2O2, further confirming the in vivo findings. From this study, it is evident that mangiferin exhibits an immunoprotective role mediated through the inhibition of reactive intermediate-induced oxidative stress in lymphocytes, neutrophils and macrophages.

Adjuvants, Immunologic↗
PubMed2005

Structural characterization, expression analysis and evolution of the red/far-red sensing photoreceptor gene, phytochrome C (PHYC), localized on the 'B' genome of hexaploid wheat (Triticum aestivum L.).

Phytochromes are a family of red/far-red light perceiving photoreceptors. The monocot phytochrome family is represented by three members, PHYA, PHYB and PHYC. We have isolated and characterized the first PHY gene member (TaPHYC) from common wheat, Triticum aestivum var. CPAN1676. It codes for a species of the photoreceptor, phyC, which is known to be light-stable in all plants analyzed so far. A sequence of 7.2 kb has been determined, which includes 3.42 kb of coding region. This is the second full-length PHYC gene sequenced from a monocot (first was from rice). TaPHYC gene shares structural similarities with the rice PHYC containing four exons and three introns in the coding region. The 5' UTR is 1.0-kb-long and harbors an upstream open reading frame (URF) encoding 28 aa. Southern blot analysis of TaPHYC indicates that it represents single locus in the wheat genome, although the possibility of additional loci cannot be completely ruled out. Chromosomal localization using nullisomic-tetrasomic lines of Triticum aestivum var. Chinese Spring places TaPHYC on chromosome 4B. PHYC represents a constitutively expressed gene in all the organs tested and under light/dark conditions. However, PHYC was found to be developmentally regulated showing maximal expression in 3-day-old dark-grown seedlings, which declined thereafter. In silico analysis has also been done to compare TaPHYC gene with the partial sequences known from other wheat species and cultivars. The presence of a topoisomerase gene immediately downstream of the PHYC gene, both in rice and wheat genomes, presents yet another example of synteny in cereals and its possible significance has been discussed.

Amino Acid Sequence↗
PubMed2005

Improved Norway spruce somatic embryo development through the use of abscisic acid combined with activated carbon.

The combination of abscisic acid (ABA) and activated carbon increased Norway spruce (Picea abies L., Karst.) cotyledonary somatic embryo yields, increased the number of genotypes forming cotyledonary embryos, caused embryos to form that exhibited improved maturation characteristics, and reduced embryo production costs. Somatic embryos increased in size, showed larger apical regions, became more zygotic-like in shape, and showed higher percentages of epicotyl development upon germination. Analyses of medium for free ABA in the presence of activated charcoal showed a rapid decrease within a few hours followed by a gradual decline over the next few days with little change from 2 to 6 weeks. Gelling agents strongly affected ABA adsorption, with agar decreasing the adsorption of ABA compared to gellan gum (Gelrite, Phytagel). Over 4,000 somatic seedlings from 20 clones were produced and established in a greenhouse using the methods discussed, and approximately 1,250 seedlings representing seven clones were established in a field setting.

Abscisic Acid↗
PubMed2005

Effect of mangiferin on hyperglycemia and atherogenicity in streptozotocin diabetic rats.

In the present study, the effect of mangiferin (a xanthone glucoside, isolated from the leaves of Mangifera indica) on the atherogenic potential of streptozotocin (STZ)-diabetes was investigated. In addition, the effect of mangiferin on oral glucose tolerance in glucose-loaded normal rats was also determined. The chronic intraperitoneal (i.p.) administration of mangiferin (10 and 20 mg/kg) once daily (o.d.) for 28 days exhibited antidiabetic activity by significantly lowering fasting plasma glucose level at different time intervals in STZ-diabetic rats. Further, mangiferin (10 and 20 mg/kg, i.p.) showed significant antihyperlipidemic and antiatherogenic activities as evidenced by significant decrease in plasma total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDL-C) levels coupled together with elevation of high-density lipoprotein cholesterol (HDL-C) level and diminution of atherogenic index in diabetic rats. In addition, the chronic administration of mangiferin (10 and 20 mg/kg, i.p.) for 14 days significantly as well as markedly improved oral glucose tolerance in glucose-loaded normal rats suggesting its potent antihyperglycemic activity. The accumulating evidences suggest that both pancreatic and extrapancreatic mechanisms might be involved in its antidiabetic or antihyperglycemic action. In conclusion, the present study demonstrates that mangiferin possesses significant antidiabetic, antihyperlipidemic and antiatherogenic properties thus suggesting its beneficial effect in the treatment of diabetes mellitus associated with hyperlipidemia and related cardiovascular complications.

Animals↗
PubMed2005

Disaster management for Nandira watershed district Angul (Orissa) India, using temporal Remote Sensing data and GIS.

NALCO--the largest exporter of aluminium in India has a power plant of 720 MW capacity in Nandira watershed in Angul district of Orissa. The power plant utilises local coal to generate thermal power and disposes of large amount of ash which accumulates in slurry form at nearby two ash ponds. These ash ponds were breached on 31 December 2000, causing ash accumulation for entire regime of the Nandira river. An attempt has been made towards preparation of recovery and rehabilitation plan for NALCO using temporal Remote Sensing data and GIS. Indian remote sensing satellite data for pre-breach condition 12 December 2000, during breach event 31 December 2000 and post-breach condition 4 and 6 January 2001 has been digitally analysed for Nandira watershed. The satellite data of coarse spatial resolution provides the absence and presence of fresh sediment deposition along Nandira watershed and Brahmani river pertaining to pre-breach and post-breach conditions respectively on regional scales. The temporal comparison of fine resolution has clearly highlighted the aerial extent of damage caused by the disaster for entire watershed on local scales. The GIS has helped in demarcation of freshly accumulated ash at interval of 500 m along the river length as well as in delineation of maximum ash accumulation across the river width. The study has clearly demonstrated the use of temporal Remote Sensing data in conjunction with GIS for disaster management in terms of recovery and rehabilitation plan preparation of the Nandira watershed.

Disaster Planning↗
PubMed2005

Gene conversions are a common cause of von Willebrand disease.

von Willebrand disease (VWD), the most common inherited bleeding disorder, is very heterogeneous, both in its phenotype and genotype. One particular molecular mechanism of VWD is due to recombination events between the true gene and its pseudogene on chromosome 22. We assessed the frequency and extension of such events in 50 multi-ethnic index patients with severe VWD type 3 and in five index patients with VWD type 2M Vicenza. One additional unclassified patient had been diagnosed with possible VWD in Russia solely on a clinical basis. Gene conversions, previously thought to be rare events, were identified in >10% of our study population: in six multi-ethnic patients with severe VWD type 3, in one patient with VWD type 2M Vicenza and the Russian patient was finally diagnosed with VWD type 2B New York/Malmoe. Our results suggest a significant contribution of this particular molecular mechanism to the manifestation of VWD. The location of the gene conversions, their extension and their occurrence as homozygous, compound heterozygous or heterozygous mutations determines the resulting phenotype.

Cells, Cultured↗
PubMed2005

Wheat cytogenetics in the genomics era and its relevance to breeding.

Hexaploid wheat is a species that has been subjected to most extensive cytogenetic studies. This has contributed to understanding the mechanism of the evolution of polyploids involving diploidization through genetic restriction of chromosome pairing to only homologous chromosomes. The availability of a variety of aneuploids and the ph mutants (Ph1 and Ph2) in bread wheat also allowed chromosome manipulations leading to the development of alien addition/substitution lines and the introgression of alien chromosome segments into the wheat genome. More recently in the genomics era, molecular tools have been used extensively not only for the construction of molecular maps, but also for identification/isolation of genes/QTLs (including epistatic QTLs, eQTLs and PQLs) for several agronomic traits. It has also been possible to identify gene-rich regions and recombination hot spots in the wheat genome, which are now being subjected to sequencing at the genome level, through development of BAC libraries. In the EST database also, among all plants wheat ESTs are the highest in number, and are only next to those for human, mouse, Ciona intestinalis (a chordate), rat and zebrafish genomes. These ESTs and sequences of several genomic regions have been subjected to a variety of applications including development of perfect markers and establishment of microcollinearity. The technique of in situ hybridization (including FISH, GISH and McFISH) and the development of deletion stocks also facilitated the preparation of physical maps. Molecular markers are also used for marker-assisted selection in wheat breeding programs in several countries. Construction of a wheat DNA chip, which will also become available soon, may further facilitate wheat genomics research. These enormous resources, knowledge base and the fast development of additional molecular tools and high throughput approaches for genotyping will prove extremely useful in future wheat research and will lead to development of improved wheat cultivars.

Agriculture↗
PubMed2005

Comparative evaluation of whole blood D-dimer test to plasma D-dimer test for diagnosis of disseminated intravascular coagulation.

Three rapid D-dimer test methods were compared for the diagnosis of acute disseminated intravascular coagulation (DIC). These were (a) SimpliRED, an autologous red cell agglutination assay. (b) DIMERTEST latex agglutination assay, containing monoclonal antibody DD-3B6/22(6), and (c) D-DI latex agglutination assay containing mouse anti-human D-dimer monoclonal antibodies. The D-DI latex method having higher sensitivity (100%) and specificity (81%) in clinically acute DIC was postulated as the gold standard and compared with the other two methods. The results suggest that D-DI latex agglutination assay containing mouse anti-human D-Dimer monoclonal antibodies are the better assay methods amongst all the three kits analyzed. It is advisable to look for the nature of the antibody used to coat the latex particles in plasma based kits. In emergency setting RBC kits may be of some use as rapid diagnosis is advantageous.

Disseminated Intravascular Coagulation↗