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Biomedical subjects

S Kabir

Publications and source records attributed to S Kabir.

At least 19 recordsLinked to original sources
PubMed2004

A study of functional endoscopic sinus surgery technique.

Endoscopic sinus surgery has become a widely accepted surgical procedure for the treatment of chronic inflammatory sinus diseases. In our study 100 patients were suffering from polyposis treated by functional endoscopic sinus surgery in MMCH. Out of 100 patients 53 patients were suffering from ethmoidal polyp and 47 patients were suffering from antrochoanal polyp between the ages 7 to 45 years. Among antrochoanal polyp 2 patients were found with inverted papilloma and came with recurrence. 40% of the patients came with a follow up visit up to 1 year. 7 out of 53 cases of ethmoidal patient came with recurrence requiring revision FESS. There was no history of patient suffering from asthma or aspirin intolerance. Overall success rate was observed in 91%. Four patients were found with periorbital haematoma and 5 with fat coming out from orbit due to injury of lamina papyraceae.

Adolescent↗
PubMed2003

Review article: clinic-based testing for Helicobacter pylori infection by enzyme immunoassay of faeces, urine and saliva.

Enzyme immunoassays have been used to detect Helicobacter pylori infection in human body materials such as faeces, urine and saliva. The stool antigen assay (HpSA), which uses polyclonal anti-H. pylori antibody as a capture reagent, has been widely used in the pre-treatment diagnosis of the infection in adults and children. Although the assay has the potential for monitoring eradication therapy, there are controversies over its use, especially at an early stage after treatment. The efficacy of the stool antigen assay can be modified by using monoclonal antibodies towards well characterized H. pylori faecal antigens. Two types of enzyme immunoassays (enzyme-linked immunosorbent assay [ELISA] and immunochromatography) have been used to detect antibodies to H. pylori in urine. Immunochromatography of urine is a rapid assay well suited for epidemiological studies. The salivary ELISA, used in a number of studies, has shown inconsistent results with less than optimum sensitivity and specificity. Urinary and salivary immunoassays may not distinguish between past and present infections, thus limiting their potential to monitor eradication therapy.

Enzyme-Linked Immunosorbent Assay↗
PubMed2003

Contrasting roles of a novel K+ channel blocker and a K+ channel opener on electro-mechanical activity in canine heart tissue.

We tested the effects of a potassium channel opener diazoxide on the action potential duration (APD) and contractile force changes in canine Purkinje tissue induced by a novel class III anti-arrhythmic agent (C3A), KCB-328 (0.5 microM) with 3,4-dimethoxyphenethyl ring structure (0.5 microM). KCB-328 shortened APD(25) by 8.3+/-2.1%, prolonged APD(50) and APD(90) by 31.2+/-5.3 and 50.0+/-7.1%, respectively. Diazoxide (0.1 mM) shortened APD at all levels by 58.3+/-8.1, 54.1+/-6.1, and 42.8+/-5.8%, respectively. In the presence of diazoxide, KCB-328 still prolonged APD(50) and APD(90) (12.5+/-3.8 and 26.8+/-5.9%, respectively). KCB-328 increased force of contraction in a dose-dependent manner. KCB-328 increased force less in the presence of diazoxide. Administration of diazoxide only, reduced force of contraction. We conclude that APD prolongation by KCB-328 may occur even in the presence of diazoxide. It is not sufficient for the restoration of already diminished contractile force and that such an APD prolongation may be unrelated to the restoration of force of contraction even though both are most often seen to occur simultaneously.

Action Potentials↗
PubMed2001

Detection of Helicobacter pylori in faeces by culture, PCR and enzyme immunoassay.

Various techniques such as culture, PCR and enzyme immunoassay have been used to detect Helicobacter pylori infection in human faecal specimens. Attempts to culture H. pylori have had limited success as the bacterium exists predominantly in a non-culturable (coccoid) form in the faeces. Several PCR protocols, differing from each other in the choice of genomic targets and primers, have been used to detect H. pylori infection. Substances in faeces that inhibit PCR have been removed by various pre-PCR steps such as filtration through a polypropylene membrane, biochemical separation by column chromatography and isolation of H. pylori with immunomagnetic beads, the former two techniques yielding results with a high degree of sensitivity and specificity. An enzyme immunoassay based on the detection of H. pylori antigen in faeces has become a convenient tool for the pre-treatment diagnosis of the infection. The stool antigen assay is convenient, especially for children, as it involves neither surgery nor the discomfort associated with the urea breath test. However, its applicability in monitoring eradication therapy has been controversial, as the assay can detect dead or partially degraded bacteria long after actual eradication, thus giving false positive results.

Adult↗
PubMed2000

Groundwater arsenic contamination in Bangladesh and West Bengal, India.

Nine districts in West Bengal, India, and 42 districts in Bangladesh have arsenic levels in groundwater above the World Health Organization maximum permissible limit of 50 microg/L. The area and population of the 42 districts in Bangladesh and the 9 districts in West Bengal are 92,106 km(2) and 79.9 million and 38,865 km(2) and 42.7 million, respectively. In our preliminary study, we have identified 985 arsenic-affected villages in 69 police stations/blocks of nine arsenic-affected districts in West Bengal. In Bangladesh, we have identified 492 affected villages in 141 police stations/blocks of 42 affected districts. To date, we have collected 10,991 water samples from 42 arsenic-affected districts in Bangladesh for analysis, 58,166 water samples from nine arsenic-affected districts in West Bengal. Of the water samples that we analyzed, 59 and 34%, respectively, contained arsenic levels above 50 microg/L. Thousands of hair, nail, and urine samples from people living in arsenic-affected villages have been analyzed to date; Bangladesh and West Bengal, 93 and 77% samples, on an average, contained arsenic above the normal/toxic level. We surveyed 27 of 42 districts in Bangladesh for arsenic patients; we identified patients with arsenical skin lesions in 25 districts. In West Bengal, we identified patients with lesions in seven of nine districts. We examined people from the affected villages at random for arsenical dermatologic features (11,180 and 29,035 from Bangladesh and West Bengal, respectively); 24.47 and 15.02% of those examined, respectively, had skin lesions. After 10 years of study in West Bengal and 5 in Bangladesh, we feel that we have seen only the tip of iceberg.

Arsenic↗
PubMed2000

The novel peptide composition of the seeds of Trichosanthes dioica Roxb.

The seeds of Trichosanthes dioica contain a large amount of peptides in the range of 2-8 kD. These peptides can be resolved in a discontinuous sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) system using Tricine as the trailing ion. The seed proteins contain a number of charge species as determined by isoelectric focusing (IEF) in polyacrylamide gels. The peptides were focused in the basic region as determined by two-dimensional electrophoresis involving IEF and SDS-PAGE. The seed peptides have the unique property of being resistant to the action of silver nitrate, a sensitive reagent commonly used to stain proteins. The seed contains haemagglutinating activity which is inhibited by galactose.

Amino Acids↗
PubMed1998

Jacalin: a jackfruit (Artocarpus heterophyllus) seed-derived lectin of versatile applications in immunobiological research.

Jacalin, the major protein from the jackfruit (Artocarpus heterophyllus) seeds, is a tetrameric two-chain lectin (molecular mass 65 kDa) combining a heavy alpha chain of 133 amino acid residues with a light beta chain of 20-21 amino acid residues. It is highly specific for the alpha-O-glycoside of the disaccharide Thomsen-Friedenreich antigen (Gal beta1-3GalNAc), even in its sialylated form. This property has made jacalin suitable for studying various O-linked glycoproteins, particularly human IgA1. Jacalin's uniqueness in being strongly mitogenic for human CD4+ T lymphocytes has made it a useful tool for the evaluation of the immune status of patients infected with human immunodeficiency virus (HIV)-1. The abundance of source material for the production of jacalin, its ease of purification, yield and stability have made it an attractive cost-effective lectin. It has found applications in diverse areas such as the isolation of human plasma glycoproteins (IgA1, C1-inhibitor, hemopexin, alpha2-HSG), the investigation of IgA-nephropathy, the analysis of O-linked glycoproteins and the detection of tumours.

Allergy and Immunology↗
PubMed1995

Serum levels of interleukin-1, interleukin-6 and tumour necrosis factor-alpha in patients with gastric carcinoma.

The possible role of inflammation-associated cytokines such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-alpha) was investigated by measuring the levels of these cytokines in serum samples from 21 patients with advanced gastric carcinoma. These values were compared with those detected in 17 age-matched controls. The levels of IL-1 beta and IL-6 were significantly increased (approximately sixfold) in gastric cancer patients. While there was a modest increase (approximately twofold) in the level of IL-1 alpha, the circulating level of TNF-alpha was greatly reduced (approximately threefold) in the patient group.

Carcinoma↗
PubMed1995

The isolation and characterisation of jacalin [Artocarpus heterophyllus (jackfruit) lectin] based on its charge properties.

Jackfruit extracts contain a protein termed jacalin which possesses diverse biological properties. A detailed analysis of its charge properties has been lacking. The present investigation was initiated to study isoelectric properties of jacalin in detail and to isolate a single isoform of jacalin. Jacalin was isolated from jackfruit extracts by affinity chromatography on immunoglobulin-A immobilised to Sepharose 4B. Various techniques such as ion-exchange chromatography, isoelectric focusing (IEF) on polyacrylamide gels and preparative liquid IEF with the Rotofor cell were used. When analysed by IEF on thin layer polyacrylamide gels, jacalin was resolved into 35 bands over a pH range of 5.0-8.5. Upon SDS-PAGE in the second dimension all these charge species gave rise to only two-bands at 12 and 15.4 kDa. The lectin was mostly eluted with 50 and 100 mM sodium chloride when jackfruit extracts were fractionated on an anion-exchange column of DEAE-cellulose. In a single 6 hour run by preparative IEF with the Rotofor cell in the pH range of 3-9.5, it has been possible to isolate pure jacalin fractions containing fewer number of charged isomers. A single jacalin isoform was isolated by subjecting a Rotofor fraction containing fewer charged species to preparative IEF on thin layer polyacrylamide gel and eluting the band of interest from the gel. The isolated jacalin isoform was biologically active as it agglutinated erythrocytes. The study reveals the complexity of jacalin as it exists as multiple charge isomers over a broad pH range. By performing preparative IEF in solution as well as in thin layer polyacrylamide gels, it was possible to isolate a single jacalin isoform with the retention of biological activity.

Antiviral Agents↗
PubMed1995

The binding of jacalin with rabbit immunoglobulin G.

Rabbit immunoglobulin G (IgG) was subjected to affinity chromatography on a column of jacalin-Sepharose 4B. While the majority of IgG molecules did not bind, a small fraction, representing about 25% of the total IgG applied, bound to jacalin-Sepharose 4B. The binding of rabbit IgG to jacalin was further evidenced by ELISA performed on jacalin coated microtitre plates. While the jacalin-retained IgG fraction displayed strong binding, the unretained fraction did not demonstrate any detectable binding. Upon SDS-PAGE, both the jacalin retained and unretained rabbit IgG fractions displayed identical protein profiles. Upon protein blotting it was demonstrated that jacalin binding sites were located only on the heavy chain of IgG. These results suggest that rabbit IgG molecules are heterogeneous with respect to their glycosylation patterns. A small fraction of rabbit IgG molecules binds jacalin and the process is probably mediated through O-linked oligosaccharides present on the heavy chain of IgG.

Animals↗
PubMed1995

Maturation of immunoglobulin-A binding proteins in the seeds of jackfruit.

The accumulation of proteins in the jackfruit seeds was monitored by extracting seeds proteins at various stages of growth. The early developing seed had several protein bands distributed over a molecular weight range of 10-67 kDa. But the mature seeds contained fewer bands with two of them being prominent at 12 and 15.4 kDa. Upon isoelectric focusing, the mature seed proteins were resolved into several bands distributed over a pH range of 4-9. While the mature seed proteins contained powerful hemagglutinating activities, these were not detected in the early developing seed. In contrast, the early developing seed had immunoglobulin A (IgA) binding activity as determined by enzyme-linked immunosorbent assay (ELISA). By Western blotting it was found that the early developing seed contained a novel 10 kDa IgA binding protein that was not present in the mature seeds.

Carrier Proteins↗
PubMed1993

Identification of a novel 4 kDa immunoglobulin-A-binding peptide obtained by the limited proteolysis of jacalin.

Jacalin, an IgA-binding lectin from jackfruit (Artocarpus heterophyllus) seeds, was isolated by the passage of PBS extracts of seeds over an affinity matrix containing IgA-Sepharose-4B. It was further purified by HPLC. When analyzed by SDS-PAGE under both reducing and nonreducing conditions, the native jacalin was dissociated into two subunits of 12 and 15.4 kDa. Both the subunits could bind IgA. Peptide mapping performed with radioiodinated jacalin indicated that both the subunits were susceptible to proteolysis by Staphylococcus aureus V8 proteinase. One degradation product was a small peptide of 4 kDa. This small proteolytic fragment also bound IgA. The amino-termini of the two major IgA binding subunits, 12 and 15.4 kDa, were identical. The 4 kDa IgA-binding proteolytic fragment of jacalin had a different amino-terminal sequence, suggesting that the region of jacalin which binds IgA does not remain close to the amino-terminus of the peptide.

Amino Acid Sequence↗
PubMed1993

Simultaneous isolation of intestinal IgA and IgG from rabbits infected intraduodenally with Vibrio cholerae 01 by combined lectin affinity chromatography involving jacalin and protein A.

Immunoglobulins of IgA and IgG isotypes are formed in host intestines after enteric infections with bacteria such as Vibrio cholerae. A method has been developed for the separation of intestinal immunoglobulins from rabbits immunized intraduodenally with live V. cholerae cells by sequential affinity chromatography on immobilized jacalin and immobilized protein A. The jacalin-Sepharose 4B bound IgA was desorbed with 0.5 M galactose. The protein A-Sepharose 4B bound IgG was desorbed with 0.1 M citrate buffer. The quality of the isolated IgA and IgG was checked by immunodiffusion in agarose gels, enzyme-linked immunosorbent assay and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The procedure described here is rapid and convenient. It can be used to isolate intestinal IgA and IgG in pure form.

Animals↗
PubMed1993

Quantum chemical and molecular mechanics studies on the binding of stereoisomers of the oligopeptide antibiotics amidinomycin and noformycin to the minor groove of B-DNA.

Ab initio calculations (Hartree-Fock) using the 6-31G basis set have been performed on two chiral oligopeptide antitumor antibiotics amidinomycin 5 and noformycin 6. The latter are DNA minor groove binding agents related to the A.T recognizing netropsin 4 and distamycin 3 but, unlike the latter, bear stereocenters (two for 5 and one for 6) that may be expected to affect binding to the B-DNA receptor. Geometry optimized conformations, energies and distribution of electrostatic charges within the molecules were derived. The rotational barrier for bond C3-C6 in 6 was calculated to be ca. 6 kcal.mole-1 and the dipole moment for 6 was 7.69D and for 5 was 5.58D. The ab initio derived parameters of the geometry optimized conformations of the different possible stereoisomeric forms of 5 and 6 were used to interpret their different interactions with the minor groove of DNA at both A.T and G.C sequences and the results were compared with molecular mechanics calculations. The order of binding of the four stereoisomers of 5 at the preferred (A.T)n sequences by both ab initio and molecular mechanics calculations is 1S,3R > RR > RS > SS. The predicted energy differences for complexation with DNA of the other stereoisomers from that of 1S,3R are: RR (4.2%); RS (6.7%) and SS (21.5%). In the case of noformycin the 4R structure binds more effectively than the enantiomer. Considerations of phasing in the computed distances between hydrogen bond donating sites in the DNA-bound antibiotics provide further insight into the binding processes. In the complexes of noformycin 6 the N-N1-N4 and N1-N5 distances (9.05 and 9.15 A respectively for 4R-6 and 9.23 and 9.26 A respectively for 4S-6) are close to the optimum value of 9.1 A for effective binding. In the case of amidinomycin 5 the best agreement with the optimum value occurs with the strongest binding diastereomer 1S,3R (N1-N3 = 8.91, N1-N4 = 9.41 A). The unexpected result, consistent in both ab initio and molecular mechanics treatments, is that, in contrast to the cases of kikumycin 1 and anthelvencin 2, the natural 3S configuration of 5 and 4S of 6 do not confer maximal binding efficiency. This suggests that biogenetic factors in the generation of the oligopeptide antibiotics lead to maximum DNA binding in the cases of kikumycin and anthelvencin but not in the cases of amidinomycin and noformycin.

Anti-Bacterial Agents↗
PubMed1991

Production and characterisation of monoclonal antibodies to outer-membrane-protein antigens of Vibrio cholerae O1.

Monoclonal antibodies (MAbs) were raised against the major, 46-48-Kda outer-membrane proteins of Vibrio cholerae O1. The hybridoma clones were screened by enzyme-linked immunosorbent assay (ELISA) with cell-surface proteins of V. cholerae O1 as the coating antigen. Four hybridomas, which secreted anti-V. cholerae cell-surface-protein antibodies, were subcloned by limiting dilution and obtained as ascites in vivo. A MAb of the IgG1 subclass was isolated in good yield from the murine ascites by affinity chromatography with recombinant protein G-Sepharose 4B. It gave positive reactions, as determined by ELISA, against cell-surface proteins prepared from both biotypes (classical and El Tor) and both serotypes (Ogawa and Inaba) of V. cholerae O1. The MAb did not have any reactivity towards V. cholerae lipopolysaccharide preparations. Immunoblotting studies were performed on cell-surface proteins separated by one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (1D SDS-PAGE) and also by two-dimensional (2D) electrophoresis with iso-electric focusing in the first dimension followed by SDS-PAGE in the second dimension. When proteins were separated by 1D SDS-PAGE, only one band at 46-48 Kda reacted with the MAb. This protein appeared to consist of two narrowly-spaced and cross-reactive bands when a nitrocellulose blot, obtained by 2D SDS-PAGE, was exposed to the MAb.

Animals↗
PubMed1989

Multiple charge isomers of human recombinant interleukin-1 beta.

Human interleukin-1 beta (rhuIL-1 beta), obtained by DNA recombinant technology, was radiolabelled. Its isoelectric properties were determined by various analytical techniques such as high-voltage ultrathin layer isoelectric focusing (IEF) and chromatofocusing. The rhuIL-1 beta molecule had a molecular mass of 18 kDa, as determined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. When examined by IEF on a polyacrylamide gel of 1 mm thickness in the pH range of 3.5-9.5, it was resolved into two broad bands appearing in the pH range of 6.2-5.8 and 5.5-5.2. Each of the two bands was further resolved into multiple bands when electrofocused on (i) a thinner gel of 0.5 mm thickness and (ii) a narrower pH range of 5-8. Upon chromatofocusing in a liquid column, it was possible to isolate various charged components of rhuIL-1 beta. However, all these components reacted to the antiserum to rhuIL-1 beta and displayed a molecular mass of 18 kDa suggesting the charge heterogeneity of rhuIL-1 beta.

Chromatography, Affinity↗