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Biomedical subjects

P Jain

Publications and source records attributed to P Jain.

At least 37 records · Page 2Linked to original sources
PubMed2002

Detection of cyclin D1 in B cell lymphoproliferative disorders by flow cytometry.

AIMS: To describe and revise a flow cytometric assay for evaluating cyclin D1 overexpression in B cell lymphoproliferative disorders (B-LPDs). METHODS: Cyclin D1 expression was evaluated in 11 healthy controls and 51 patients with B-LPD by flow cytometry using the 5D4 monoclonal antibody. In 25 cases, experiments were repeated up to four times with mononuclear cells (MNC) fixed in ethanol for 1-120 days to evaluate the consistency of cyclin D1 expression. Flow cytometry results were compared with fluorescence in situ hybridisation (FISH) for the t(11;14) translocation in 19 patients and with immunohistochemistry (IHC) using the DCS-6 monoclonal antibody in nine patients. RESULTS: A mean fluorescence intensity ratio (MFIR) of 4.8 was defined as the cut off point for positivity based on cyclin D1 expression in healthy controls (mean + 3 SD). Ten patients overexpressed cyclin D1 by flow cytometry. These included five of eight patients with mantle cell lymphoma, four of 19 with chronic lymphocytic leukaemia, and one with follicular lymphoma. MFIR in the repeat experiments differed less than 25% in 20 of 25 patients and in no cases did it cross the cut off point. There was a good correlation between cyclin D1 expression by flow cytometry and FISH for t(11;14) in 15 of 19 patients and six of nine had concordant results with flow cytometry, FISH, and IHC. CONCLUSION: Cyclin D1 expression remains fairly stable once MNC are fixed in ethanol and the flow cytometric assay can be used for the routine screening of B-LPD. Further comparisons between flow cytometry, IHC, and FISH may be needed to ascertain the diagnostic value of the flow cytometric assay.

B-Lymphocytes↗
PubMed2002

DNA topoisomerase I from mycobacteria--a potential drug target.

DNA topoisomerases are ubiquitous group of enzymes altering the topology of DNA by concerted breakage and rejoining of the phosphodiester backbone of DNA. The enzymes are classified based on the pattern of DNA cleavage. Type IA enzymes found in all bacteria nick the DNA and attach themselves covalently to the 5' side of the nick during the first transesterification reaction. Most of the information on this group of enzymes comes from studies with E. coli topoisomerase I and III. Members of type IA group are single subunit Zn(++) metalloenzymes recognizing single stranded DNA without high degree of sequence specificity during relaxation reaction of negatively super coiled DNA. So far no inhibitors are known for this group of enzymes inspite of their important role in maintaining homeostasis of DNA topology. Molecular characterization of DNA topoisomerase I from mycobacteria has revealed some of the important features of type IA enzymes hitherto unknown and provide scope for identifying novel inhibitors. The present review describes the recent developments in the area summarizing the distinctive features of mycobacterial topoisomerase I. The enzyme has several properties not shared by either type IA or IB enzymes with respect to DNA binding, recognition, sequence specificity and interaction pattern. The physiological basis of the unusual features is discussed. The unique properties described would aid in developing the enzyme as a target molecule in pharmaceutical design. In addition, the findings lead to address some fundamental questions on the intracellular role of topoisomerase I in the biology of mycobacteria which are one of the most formidable group of pathogenic organisms.

Amino Acid Sequence↗
PubMed2002

Pegnology: a review of PEG-ylated systems.

Polyethylene glycol conjugation or linking with the system is called PEGylation. Many novel drug systems are used for the delivery of drugs and bioactive substances to particular sites in a controlled or sustained manner, but various side effects or shortcomings restrict their use for the intended purpose. The shortcomings such as RES uptake, drug leakage, immunogenicity, stability, hemolytic toxicity etc. can generally be overcome by PEGylation of novel drug delivery systems such as liposomes, proteins, enzymes, drugs, nanoparticles etc. In this article the whole aspect of PEGylation starting from activation and derivatisation of poly (ethylene glycol) to the linking and designing of systems and their purification and characterization is discussed. The various properties of Pegylated systems are also discussed.

Animals↗
PubMed2001

Polarized electromagnetic radiation from spatially correlated sources.

We consider the effect of spatial correlations in sources of polarized electromagnetic radiation. We evaluate the coherency matrix for a spatially extended three-dimensional source in order to obtain its dependence on the angular position of the observer in the far zone. We find a general condition on the source correlation matrix under which the polarization in the far zone shows no angular dependence. In general, however, we find that the polarization shows a rather striking dependence on the direction of observation. We illustrate this effect by considering some examples of monochromatic spatially correlated sources. The sources, assumed to be monochromatic, are constructed out of dipoles aligned along a line such that their orientation is correlated with their position. In one representative example, the dipole orientations are prescribed by a generalized form of the standard von Mises distribution for angular variables such that the azimuthal angle of dipoles is correlated with their position. In another example the tip of the dipole vector traces a helix around the symmetry axis of the source. Possible experimental observation of this effect, by considering an analog of the standard two-slit interference experiment, is also discussed. The effect may find useful applications in certain astrophysical sources.

Journal Article↗
PubMed2001

Spectral dependence of polarized radiation due to spatial correlations.

We study the polarization of light emitted by spatially correlated sources. We show that, in general, polarization acquires a nontrivial spectral dependence due to spatial correlations. The spectral dependence is found to be absent only for a special class of sources where the correlation length scales as the wavelength of light. We further study cross correlations between two spatially distinct points that are generated due to propagation. It is found that such cross correlation leads to a sufficiently strong spectral dependence of polarization which can be measured experimentally.

Journal Article↗
PubMed2001

Relationship between V3 sequences of HIV type 1 from plasma, T cells, and dendritic cells suggests that plasma virus may arise from different cell sources.

Nucleotide sequences of HIV-1 from plasma virus RNA and proviral DNA extracted from blood dendritic cells (DCs) and from T cells were analyzed to determine whether blood DCs may harbor a restricted population of virus variants. The sequence of the V3 loop and 51 bases from the 3' flanking region were determined in four patients not receiving antiviral therapy. There was no evidence of a unique or more restricted population of variants in DCs for any of the four patients studied. However, for one patient there was evidence of differences between plasma virus and virus in the T cell population, with virus in the plasma showing a closer relationship to DC-derived sequences.

Amino Acid Sequence↗
PubMed2001

Burkitt's lymphoma of stomach: A case report and review of literature.

Primary gastrointestinal non-Hodgkin's lymphoma is a distinct clinicopathological entity. This is the commonest site of all extranodal lymphomas. Non-endemic Burkitt's lymphoma (high-grade, small non-cleaved lymphocytic type) is rare in non-HIV adult population. We hereby report Burkitt's lymphoma of stomach in a non-HIV adult. Gastric and lymph node biopsy confirmed the diagnosis. Patient was treated using a third generation chemotherapy protocol without any surgical resection. The patient relapsed within 3 months of completion of primary treatment and died of progressive disease.

Adult↗
PubMed2001

Ammonia chemical ionization tandem mass spectrometry in structural determination of alkaloids. II. Tetraponerines from pseudomyrmecine ants.

Chemical ionization tandem mass spectrometry (CI-MS/MS) of alkaloids with ammonia reagent gas and collision-activated dissociation as well as EI-MS/MS were applied to the tetraponerine alkaloids in extracts from six pseudomyrmecine ants of the genus Tetraponera. The MS/MS techniques along with gas chromatography Fourier transform infrared (GC/FTIR) spectra allowed identification in two extracts of seven of the eight known tetraponerines. The EI-MS/MS fragmentations proved diagnostic for the ring system and the CI-MS/MS patterns for the C-8 or C-9 substitution, while the Bohlmann bands in FTIR spectra were diagnostic for the C-8 or C-9 configurations. An Indian ant (T. allaborans) had T-2, T-4 and T-8, while a Chinese ant (T. binghami) had T-5, T-6, T-7 and T-8. Four other ants, T. rufonigra (India), T. penzigi (Africa), T. clypeata (Africa) and T. sp. cf. emeryi (Africa), had no tetraponerines.

Alkaloids↗
PubMed2001

Variation in random amplified polymorphic DNA (RAPD) profiles specific to fluconazole-resistant and -sensitive strains of Candida albicans.

Random amplified polymorphic DNA analysis was used to detect genotype relatedness among clinical fluconazole-resistant and -sensitive strains of Candida albicans recovered from twenty HIV-infected patients having oropharyngeal candidiasis. Sensitive strains were obtained from a local hospital and were from patients that had not been treated with azole drugs while resistant strains were recovered from patients in different parts of Europe and their resistance was a consequence of drug-treatment given to the patients. On amplification with different arbitrary sequence decamer primers, the results demonstrated a homogeneous banding pattern for all sensitive strains that was distinct from that obtained in case of the resistant strains. The DNA profiles of strains were thus broadly clustered into two major groups of resistant and sensitive strains. The RAPD technique may be useful in differentiating fluconazole-resistant strains from the -sensitive ones for early identification of resistant isolates from AIDS patients.

AIDS-Related Opportunistic Infections↗
PubMed2001

Structure of alkaloid 275A, a novel 1-azabicyclo[5.3.0]decane from a dendrobatid frog, Dendrobates lehmanni: synthesis of the tetrahydrodiastereomers.

The principal alkaloid 275A in skins of the Colombian poison frog Dendrobates lehmanni has been identified as the pyrrolo[1,2-a]azepane (1), the first occurrence in nature of this "izidine" system. Tetrahydro-1 proved identical to one of the four synthetic diastereomers, 2a--2d, thereby establishing that 1 has the 5Z,10E relative stereochemistry. Alkaloid 1 is often accompanied by other congeners, in particular a 5Z,10Z diastereomer 15, a dihydro analogue 16, and a ketone 17. Such izidines in frogs may arise from dietary ants, as do other classes of izidines.

Alkaloids↗
PubMed2001

Spiral CT for lung cancer screening: is it ready for prime time?

Low-dose spiral computed tomography (CT) shows promise as a screening test for lung cancer, as it detects many more malignant pulmonary nodules than does standard plain radiography of the chest. Yet until more data are available we need to temper our enthusiasm. No studies have yet determined if using low-dose spiral CT as a screening test will lead to lower mortality rates. This paper reviews the issue of lung cancer screening and low-dose spiral CT.

Aged↗
PubMed2001

Compensatory hyperparathyroidism following high fluoride ingestion - a clinico - biochemical correlation.

OBJECTIVE: To evaluate the effect of varying ingestion of drinking water containing high fluorides and its effect on serum parathyroid hormone. DESIGN: Cross sectional clinical study. SETTING: S.M.S. Medical College, Jaipur. SUBJECT: 200 children were selected from four areas (50 from each area) consuming water containing 2.4, 4.6, 5.6 and 13.5 mg/l of fluoride. All children were in an age group of 6 to 12 years. METHODS: All children were graded for clinical, radiological and dental fluorosis and biochemical estimations were made for serum calcium, serum and urinary fluoride and serum parathyroid hormone. RESULTS: Serum calcium levels were well within normal range in the patients of all areas but an increase in serum parathyroid levels (S. PTH) was noted. The increased S. PTH was well correlated with increase in fluoride ingestion. The severity of clinical and skeletal fluorosis was observed to increase with increase in S. PTH concentration. CONCLUSIONS: High Fluoride ingestion has a definite relationship with increased parathyroid hormone secretion, which may be responsible for maintaining serum calcium levels and may have a role in toxic manifestations of fluorosis.

Child↗
PubMed2000

Granular acute lymphoblastic leukemia with hypereosinophilic syndrome.

A four-year-old boy presented with marked peripheral blood eosinophilia (absolute eosinophil count of 54 x 10(9)/1), features of hypereosinophilic syndrome, and acute lymphoblastic leukemia (ALL-L2), the latter characterized by the presence of granular blasts. Blasts were negative for myeloperoxidase, non-specific esterase, acid phosphatase, periodic-acid Schiff stain, and toluidine blue. They exhibited an early pre-B immunophenotype (TdT, CD19, CD10, CD20 and CD22 positive) and stained negative for T (CD7, CD2, CD5 and CD3) and myeloid markers (MPO, CD33 and CD13). Chromosomal analysis revealed a normal karyotype. To the best of our knowledge, this case represents the first report of the coexistence of granular ALL and hypereosinophilic syndrome.

Child, Preschool↗
PubMed2000

Testosterone supplementation for erectile dysfunction: results of a meta-analysis.

PURPOSE: To our knowledge a causal relationship between altered levels of androgens and erectile dysfunction has not yet been established. We reviewed the literature to assess the usefulness of androgen replacement for erectile dysfunction. MATERIALS AND METHODS: Meta-analysis was chosen as the method of evaluating the literature. Study inclusion criteria were testosterone given as the only therapy for erectile dysfunction and a clearly stated definition of response for evaluating treatment success or failure. RESULTS: We evaluated 73 articles obtained by a MEDLINE search of 1966 to 1998 and included 16 in our study. The overall response rate was 57%. In the 9 series with response rate by etiology patients with primary versus secondary testicular failure had a response rate of 64% versus 44% (p <0.001). Intramuscular and oral methods of delivery were equivalent with a response rate of 51.3% and 53.2%, respectively. However, the response to transdermal therapy was significantly different from that of intramuscular and oral treatment (80.9% versus 51.3% and 53.2%, respectively, p <0.001). The mean confidence level response for testosterone treatment was 16. 7% in the placebo and 65.4% in the treated group (p <0.0001). CONCLUSIONS: Our meta-analysis of the usefulness of androgen replacement therapy for erectile dysfunction indicates that the response rate for a primary etiology was improved over that for a secondary etiology, transdermal testosterone therapy was more effective than intramuscular or oral treatment, and intramuscular and oral treatments were equivalent. In addition, there was a statistically significant difference in favor of testosterone over placebo, implying a role for supplementation in select groups.

Administration, Oral↗
PubMed2000

Metastatic carcinoma in hepatic hemangioma.

Metastasis into the hepatic hemangioma is a rare occurrence. We report a unique case of metastasis of intestinal carcinoma into hepatic hemangioma in a case of 65 year old male who presented with anorexia, weakness and headache. The postmortem examination revealed adenocarcinoma in the ileocaecal region. The liver showed a subcapsular hemangioma of 1.5 cms. diameter which on microscopic examination revealed metastasis of adenocarcinoma. The is the first documentation of metastasis in hepatic hemangioma. Such cases may pose problems of diagnostic difficulties and thus may result in mismanagement.

Aged↗