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Biomedical subjects

A Kundu

Publications and source records attributed to A Kundu.

At least 19 recordsLinked to original sources
PubMed2004

Use of RAPD-PCR for genetic analysis of Nicobari fowl of Andamans.

1. The present study was conducted to estimate genetic relatedness among Nicobari fowls (Brown, Black and White) and an exotic bird (White Leghorn) using random amplified polymorphic DNA (RAPD) polymorphism. 2. A total of 25 decamer primers were screened among all the breeds of which 24 primers amplified the genomic DNA, generating 2000 to 200 bp bands. Ten primers generated reproducible and distinct RAPD profiles and were used for further analysis. 3. A total of 94 bands were amplified and 30 polymorphic bands (32%) were produced. The number of polymorphic loci ranged from 1 to 5 with an average of 3.0. 4. Among the native breeds Brown Nicobari showed higher genetic similarity (0.85) than Black Nicobari (0.80) and White Nicobari fowl (0.82). 5. Brown Nicobari showed high genetic similarity with Black Nicobari (0.87 +/- 0.029); least similarity was between White Nicobari and White Leghorn (0.77 +/- 0.028). 6. The RAPD profile of all Nicobari fowls on amplification with the primers PBG5 and PBA12 showed specific bands of molecular size 1050 and 785 bp, respectively. 7. The native breeds showed the least genetic distance with each other while White Leghorn appeared to be most distant from the native breeds.

Animals↗
PubMed2000

Claisen rearrangement of allyl phenyl ether and its sulfur and selenium analogues on electron impact

The electron impact (EI) mass spectrum of allyl phenyl ether (1) includes an ion at m/z 106 that is formed mainly by the loss of CO from the molecular ion, as supported by high resolution and MS/MS data. The formation of the [M - CO](+) ion from 1 can be explained in terms of the Claisen rearrangement of 1 after ionization in the ion source of the mass spectrometer. Similarly, allyl phenyl sulfide (2) and allyl phenyl selenide (3) showed characteristic ions corresponding to [M - CH(3)](+), [M - XH](+) (X = S or Se) and [M - C(2)H(4)](+.), and the formation of these ions are explained via Claisen rearrangement of 2 and 3 in the ion source of the mass spectrometer resulting in a mixture of rearrangement products. The formation of molecular ions of 2-allyl thiophenol and 2-allyl selenophenol as intermediates, that cannot be isolated as the neutrals from the solution phase Claisen rearrangement of 2 and 3, respectively, is clearly indicated in the gas phase. The mass spectra of the rearrangement products obtained from the solution phase reaction were also consistent with the proposal of formation of these products in the ion source of the mass spectrometer. The formation of characteristic fragment ions attributed to the Claisen rearrangement products are also evident in the collision induced dissociation spectra of the corresponding molecular ions. Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1999

Mass spectral study of substituted allyl aryl and allyl alkyl selenides and some analogous sulfides

The electron impact (EI) mass spectra of allyl aryl selenides showed abundant molecular ions and many fragment ions containing the selenium atom. alpha-Cleavage is the dominant process in the fragmentation of selenides, and cleavage product ions are characteristic of the substituents. In the case of 3-methyl allyl and related aryl selenides, characteristic delta-hydrogen migration to the selenium atom is observed. A McLafferty-type rearrangement is found in benzyl allyl selenides and substituted alkyl allyl selenides. The charge on the rearrangement products preferably remains on the fragments containing the phenyl group. The [M - SeH](+), [M - CH(3)](+) and [M - C(2)H(4)](+) ions are found only in the EI mass spectrum of allyl phenyl selenide, and are attributed to a Claisen rearrangement in the source of the mass spectrometer. All structurally informative fragmentation processes are supported by collision induced dissociation spectra of molecular ions. The fragmentation patterns found in methane chemical ionization (CI) spectra of the selenides were significantly different from those observed in EI. The EI and CI mass spectra of analogous sulfides showed similar behaviour to that observed in the corresponding selenides. Copyright 1999 John Wiley & Sons, Ltd.

Journal Article↗
PubMed1999

Antibody response to sheep erythrocytes in Indian native vis-à-vis imported breeds of chickens.

1. A total of 433 birds (7 weeks old) of both sexes belonging to Indian native breeds, including, Aseel, Kadakanath, Naked Neck and Frizzle fowl along with the imported breeds Dahlem Red, White Leghorn, Synthetic dam line broiler (SDL) and Naked Neck broiler were utilised to test the primary antibody response to sheep erythrocytes by haemagglutination test. The effect of genotype (breed), sex and their interactions on antibody response were also studied. 2. The results revealed the presence of natural antibodies in all groups under study. 3. All groups except broilers showed the highest HA titre on day 5 post immunisation, which gradually declined until the end of the experiment (19th day post immunisation). In broilers, the peak HA titre was observed on day 12. 4. Dahlem Red showed the highest response throughout. The lowest antibody response was recorded for broilers except on day 19 post immunisation when it exceeded the White Leghorn value. 5. Amongst the native Indian breeds, the Naked neck had the highest titre on day 5 post immunisation but the Aseel titre was highest on days 12 and 19. 6. Males tended to have higher titres than females in Aseel, Kadakanath, Naked Neck, White Leghorn and Naked Neck broilers whereas Frizzle, Dahlem Red and SDL broilers showed the converse. 7. Statistical analysis revealed significant variation in HA response among the various genetic groups on different days post immunisation. The apparent differences between sexes were not significant. However, interactions between breed and sex were significant on day 5 and 19 post immunisation.

Animals↗
PubMed1999

Coupled nonlinear Schrödinger equations with cubic-quintic nonlinearity: Integrability and soliton interaction in non-Kerr media.

We propose an integrable system of coupled nonlinear Schrödinger equations with cubic-quintic terms describing the effects of quintic nonlinearity on the ultrashort optical soliton pulse propagation in non-Kerr media. Lax pairs, conserved quantities and exact soliton solutions for the proposed integrable model are given. The explicit form of two solitons are used to study soliton interaction showing many intriguing features including inelastic (shape changing or intensity redistribution) scattering. Another system of coupled equations with fifth-degree nonlinearity is derived, which represents vector generalization of the known chiral-soliton bearing system.

Journal Article↗
PubMed1998

Management of vulval pain--whose responsibility?

Vulval pain can be acute or chronic. Usually patients present to their general practitioner when the pain is acute but, when specialist advice is required, vulval pain can present a real dilemma over to whom to refer patients. Genitourinary medicine, gynaecology, dermatology and sexual dysfunction clinics all play an important part in the holistic management of this symptom. Consultation in a sympathetic environment with appropriate investigations and collaboration between different disciplines may provide a diagnosis and management.

Female↗
PubMed1997

Low-molecular-weight displacers for high-resolution protein separations.

The resolving power of displacement chromatography using low-molecular-weight displacers was investigated using a model mixture containing bovine and horse heart cytochrome c. The linear and nonlinear adsorption behavior of these two proteins was examined in cation-exchange chromatography and shown to be quite similar. Furthermore, an analysis of the dynamic affinity of these proteins indicated extremely similar affinities under displacement conditions. Despite the extreme similarities in the adsorption behavior, displacement chromatography using a protected amino acid displacer resulted in excellent separation of the proteins with both high yields and purity. These results indicate that displacement chromatography may be efficacious for a wide variety of difficult protein separation problems.

Adsorption↗
PubMed1996

Transmembrane domain of influenza virus neuraminidase, a type II protein, possesses an apical sorting signal in polarized MDCK cells.

The influenza virus neuraminidase (NA), a type II transmembrane protein, is directly transported to the apical plasma membrane in polarized MDCK cells. By using deletion mutants and chimeric constructs of influenza virus NA with the human transferrin receptor, a type II basolateral transmembrane protein, we investigated the location of the apical sorting signal of influenza virus NA. When these mutant and chimeric proteins were expressed in stably transfected polarized MDCK cells, the transmembrane domain of NA, and not the cytoplasmic tail, provided a determinant for apical targeting in polarized MDCK cells and this transmembrane signal was sufficient for sorting and transport of the ectodomain of a reporter protein (transferrin receptor) directly to the apical plasma membrane of polarized MDCK cells. In addition, by using differential detergent extraction, we demonstrated that influenza virus NA and the chimeras which were transported to the apical plasma membrane also became insoluble in Triton X-100 but soluble in octylglucoside after extraction from MDCK cells during exocytic transport. These data indicate that the transmembrane domain of NA provides the determinant(s) both for apical transport and for association with Triton X-100-insoluble lipids.

Amino Acid Sequence↗
PubMed1995

Interaction of Sendai viral F, HN, and M proteins with host cytoskeletal and lipid components in Sendai virus-infected BHK cells.

We have studied the interaction of Sendai viral fusion (F), hemagglutinin/neuraminidase (H/N), and matrix (M) proteins with host cytoskeletal and lipid components in Sendai virus-infected BHK cells using two nonionic detergents Triton X-100 (TX-100) and octyl glucoside (OG). Our results show that while M protein acquired resistance to both TX-100 and OG extraction, F and HN exhibited insolubility only to TX-100 but not to OG. Furthermore, in the presence of high salt (1 M NaCl), M, but not F or HN, became TX-100 soluble. Both type I (F) and type II (HN) viral glycoproteins acquired TX-100 insolubility at a late stage during exocytic transport as they acquired endo H resistance. In addition, TX-100 insoluble F and HN exhibited a lighter density compared to TX-100 resistant M by flotation analysis. Using recombinant vaccinia viruses that express Sendai virus HN, F, or M protein individually, we observed that each viral protein (F, HN, or M) was independently capable of acquiring TX-100 insolubility in the absence of other viral components. These results would indicate that while Sendai viral F and HN became bound to TX-100 insoluble lipids, M protein bound ionically to TX-100 insoluble cytoskeletal components and not to TX-100 insoluble lipids.

Animals↗