PubMed Health⌕ Search

Biomedical subjects

A K Banerjee

Publications and source records attributed to A K Banerjee.

At least 109 records · Page 6Linked to original sources
PubMed1996

Prediction of optimum dimensions of colonic pouch reservoir.

PURPOSE: A mathematic model was developed to quantify colonic reservoir pouch capacity and to allow comparison with capacity of the parent colonic segment from which the pouch was fashioned. METHODS: Using geometry, pouch capacity was calculated and various capacities were enumerated. RESULTS: From this model, ideal pouch dimensions can be predicted, which are 6 to 7 cm of undistended bowel circumference with limb lengths of 8 to 10 cm. CONCLUSIONS: Such a pouch maximizes the pouch colon capacity ratio and has a calculated undistended capacity between 60 and 105 ml.

Colon↗
PubMed1996

Aseptic cerebral venous thrombosis associated with idiopathic ulcerative colitis: a report of two cases.

Two cases of cerebral venous thrombosis with ulcerative colitis with complete autopsy findings are reported. The diagnosis of cerebral venous thrombosis with ulcerative colitis was made during life in one case and at autopsy showed active chronic ulcerative colitis with recent cerebral venous thrombosis with cerebral infarction. In the other case active chronic ulcerative colitis and old cerebral venous thrombosis with cerebral infarction were diagnosed at autopsy. Although rare the importance of recognising cerebral venous thrombosis as a complication of ulcerative colitis has been emphasised in view of the high mortality of this complication.

Adult↗
PubMed1996

Expression of L protein of vesicular stomatitis virus Indiana serotype from recombinant baculovirus in insect cells: requirement of a host factor(s) for its biological activity in vitro.

The 241-kDa large (L) protein of vesicular stomatitis virus (VSV) Indiana serotype, a multifunctional catalytic subunit of the viral RNA polymerase, has been expressed in Spodoptera frugiperda cells infected with recombinant baculovirus BacPAK6-L containing the L gene under the control of a polyhedrin promoter. The recombinant L protein was biologically active and supported viral mRNA synthesis in vitro. When the expressed L protein was purified by phosphocellulose column chromatography, it eluted in two peaks, one at 0.4 M NaCl (peak I) and the second at 0.75 M NaCl (peak II). The L protein in peak I showed significant transcriptional activity in an in vitro transcription reconstitution experiment, whereas the L protein in peak II was inactive. Interestingly, the addition of cytoplasmic extract from uninfected Sf21 cells to peak II completely restored transcription in vitro, indicating the requirement of a host factor(s) for the activity of the L protein. This factor is relatively heat stable and is dissociable from the recombinant L protein. It is also present in BHK, COS, and HeLa cells in detectable levels. The role of the putative host protein(s) in the activation of the L protein is discussed.

Animals↗
PubMed1996

Reflux oesophagitis and Helicobacter pylori infection in elderly patients.

Helicobacter pylori is associated with gastritis, peptic ulcers and gastric malignancies. Little attention has been paid to the possibility that it may also have a role in the pathogenesis of reflux oesophagitis. This is especially true in elderly patients who have life-long infection and provide an ideal group to study the mucosal changes associated with the organism. The aim of this study was to determine if H pylori is associated with reflux oesophagitis in elderly patients. Consecutive gastroscopy patients were recruited. Multiple biopsies were taken from oesophagus, stomach, antrum and duodenum for histology and rapid urease tests. Patients also had IgG ELISA antibodies and 13C-urea breath tests performed. Patients with macroscopic or microscopic evidence of reflux oesophagitis were compared to patients with macroscopically normal upper gastrointestinal tracts and no microscopic evidence of reflux. A total of 114 patients were recruited, average age 78.9 years (+/- 5.4). There were 37 refluxers and 33 non-refluxers. We found no evidence for an association between the presence of H pylori and reflux oesophagitis in elderly patients. The high prevalence of H pylori in patients with reflux oesophagitis can be explained by the presence of incidental gastritis.

Aged↗
PubMed1996

Primary pulmonary malignant teratoma with yolk sac element associated with hematologic neoplasia.

We describe the unique case of a primary pulmonary malignant teratoma with yolk sac elements, associated with hematologic neoplasia. This 20-year-old male was admitted with complaints of fever, right-sided chest pain, dry cough, and hemoptysis. Necropsy revealed a mass in the right middle and upper lobe which microscopically was a malignant teratoma with yolk sac element. The associated hematologic neoplasia was a myelofibrosis, cellular phase, with myeloid metaplasia in liver, spleen, hilar lymph nodes, left adrenal gland, and lower lobe of the right lung.

Adult↗
PubMed1996

Lack of association between helicobacter pylori and gastric atrophy or intestinal metaplasia in elderly patients.

Helicobacter pylori (Hp) is associated with gastritis and peptic ulcers. It may also induce gastric atrophy (GA) and intestinal metaplasia (IM), and these changes may be the precursors of gastric carcinoma. The aim of this study was to determine if GA or IM is associated with Hp infection in elderly patients. Consecutive patients admitted for gastroscopy were recruited. Multiple biopsies were taken for histology and rapid urease (CLO) tests along with IgG enzyme-linked immunosorbent assay antibodies and (13)C-urea breath tests. Statistical analysis was by chi(2) tests. 114 patients were recruited, the average age was 78.9 + or - 5.4 years. Histology was available on 105 patients, 80 (76.2%) had gastritis, and 61/80 (76.25%) had evidence of definite current Hp infection. Seven patients had reflux gastritis, and these were excluded from the analysis described below. 20 patients had GA and 24 IM. The relationship between Hp and GA or IM was investigated by dividing patients into four groups: Group 1 patients (n = 57) were taken to be definitely currently infected (GA 7 patients, IM 11, both 1). Group 2 patients (n = 18) had old infection (GA 2, IM 4, both 3). Group 3 patients (n = 16) have never been infected previously (GA 1, IM 1, both 3). Group 4 patients (n = 4) had a poor immunological response to Hp (GA 1, IM 1, both 0). There were no significant differences in the numbers of patients with GA or IM in any group as compared with any other, with the exception of less patients with histological evidence of combined GA and IM among patients with definite current infection as compared with those with either previous infection (p = 0.04) or 'never' infection (p = 0.03). We conclude that the mucosal changes of GA or IM are not consistently associated with Hp infection in the elderly.

Aged↗
PubMed1996

Prospective study of the proctographic and functional consequences of transanal endoscopic microsurgery.

A prospective study of clinical, manometric and proctographic results in 36 patients presenting for transanal endoscopic microsurgery was performed. Anorectal manometry showed no difference in maximal squeeze pressure before and 12 months after operation, but resting pressures were lower after surgery (mean(s.e.m.) preoperative 86.1(27.6) mmHg versus postoperative 67.2(23.2) mmHg, P < 0.05). The rectoanal inhibitory reflex was lost in a significant group of patients (reflex present in 34 of 36 patients before operation and in 27 of 36 12 months after operation, P < 0.05). Proctography, manometry and questionnaire showed preserved function of most modalities 12 months after operation such that if objective function was impaired clinical function was adequate.

Adult↗
PubMed1996

Eye changes in non-specific aorto-arteritis.

Non-specific aorto-arteritis or Takayasu's arteritis is fairly common and has been reported from all parts of India. The disease presents with various eye symptoms such as transient or permanent blindness, headache and signs including neovascularisation, retinal anastomosis, rubeosis iridis, cataracts. Eye manifestations depend on stage of disease and degree of involvement of cervical arteries. This review consists of an indepth impression of eye involvement in non-specific aorto-arteritis.

Eye Diseases↗
PubMed1995

Role of cellular casein kinase II in the function of the phosphoprotein (P) subunit of RNA polymerase of vesicular stomatitis virus.

The phosphorylation of the P protein of vesicular stomatitis virus by cellular casein kinase II (CKII) is essential for its activity in viral transcription. Recent in vitro studies have demonstrated that CKII converts the inactive unphosphorylated form of P (P0) to an active phosphorylated form P1, after phosphorylation at two serine residues, Ser-59 and Ser-61. To gain insight into the role of CKII-mediated phosphorylation in the structure and function of the P protein, we have carried out circular dichroism (CD) and biochemical analyses of both P0 and P1. The results of CD analyses reveal that phosphorylation of P0 to P1 significantly increases the predicted alpha-helical structure of the P1 protein from 27 to 48%. The phosphorylation defective double serine mutant (P59/61), which is transcriptionally inactive, possesses a secondary structure similar to that of P0. P1, at a protein concentration of 50 micrograms/ml, elutes from a gel filtration column apparently as a dimer, whereas both P0 and the double serine mutant elute as a monomer at the same concentration. Interestingly, unlike wild-type P1 protein, the P mutants in which either Ser-59 or Ser-61 is altered to alanine required a high concentration of CKII for optimal phosphorylation. We demonstrate here that phosphorylation of either Ser-59 or Ser-61 is necessary and sufficient to transactivate L polymerase although alteration of one serine residue significantly decreases its affinity for CKII. We have also shown that P1 binds to the N-RNA template more efficiently than P0 and the formation of P1 is a prerequisite for the subsequent phosphorylation by L protein-associated kinase. In addition, mutant P59/61 acts as a transdominant negative mutant when used in a transcription reconstitution assay in the presence of wild-type P protein.

Amino Acid Sequence↗
PubMed1995

Human parainfluenza virus type 3 phosphoprotein: identification of serine 333 as the major site for PKC zeta phosphorylation.

The human parainfluenza virus type 3 P protein is an RNA polymerase subunit involved in both transcription and replication during the life cycle of the virus. Our laboratory has recently shown that the P protein is phosphorylated both in vitro and in vivo by the cellular protein kinase C (PKC) isoform zeta and that this phosphorylation is essential for viral replication. To identify the site(s) of phosphorylation, we have used CNBr cleavage, phosphoamino acid analysis, and two-dimensional tryptic peptide mapping of the in vitro and in vivo phosphorylated P protein. We demonstrate that when bacterially expressed unphosphorylated P is labeled in vitro with either commercial PKC or purified recombinant PKC zeta P protein has one major phosphorylation site. By site-directed mutagenesis of PKC consensus sites in the P protein, the primary phosphorylation site is found to be Ser 333. The same site appeared to be modified when viral P protein was phosphorylated in vitro by the PKC packaged within the virion and in the P protein of progeny virion labeled in vivo.

Amino Acid Sequence↗
PubMed1995

Involvement of cellular casein kinase II in the phosphorylation of measles virus P protein: identification of phosphorylation sites.

The phosphoprotein P gene of measles virus (Edmonston strain) has been cloned in the Escherichia coli expression vector pET-3a with a histidine tag at the C-terminal end. The expressed protein was soluble, unphosphorylated, and constituted 10 to 20% of total cellular protein. Recombinant P protein purified by Ni-affinity chromatography was found to be efficiently phosphorylated in vitro by recombinant casein kinase II (CKII) or by the CKII activity present in the uninfected cell extract. A comparison of phosphopeptide analyses between the in vivo- and the in vitro-32P-labeled P proteins revealed that both proteins share common phosphorylation sites. In an attempt to identify the exact site of the CKII-mediated phosphorylation, we altered specific serine residues located within the CKII consensus motif to alanine by site-directed mutagenesis. The results indicate that Ser 86, Ser 151, and Ser 180 located within the N-terminal half of the P protein are involved in the CKII-mediated phosphorylation of the P protein.

Alkaloids↗
PubMed1995

Interaction between the nucleocapsid protein and the phosphoprotein of human parainfluenza virus 3. Mapping of the interacting domains using a two-hybrid system.

A two-hybrid system was used to study interaction in vivo between the nucleocapsid protein (NP) and the phosphoprotein (P) of human parainfluenza virus type 3 (HPIV-3). Two plasmids, one containing the amino terminus of P fused to the DNA-binding domain of the yeast transactivator, GAL4, and the other containing the amino terminus of NP fused to the herpesvirus transactivator, VP16, were transfected in COS-1 cells along with a chloramphenicol acetyltransferase (CAT) reporter plasmid containing GAL4 DNA-binding sites. A specific and high-affinity interaction between NP and P was observed as measured by the activation of the CAT gene. Mapping of the domains in P (603 amino acids) involved in the association with NP revealed that NH2-terminal 40 and COOH-terminal 20 amino acids are important for such association. Interestingly, a stretch of NH2-terminal amino acids as short as 63-403 interacted with NP more than the wild type, reaching greater than 2.5-fold as measured by the CAT assay. These results suggest that a domain is present in P that negatively regulates its interaction with NP. Deletion of NH2-terminal 40 and COOH-terminal 160 amino acids of NP reduced the CAT activity by more than 95%. These results underscore the important differences between negative strand RNA viruses with respect to interactions between these two viral proteins involved in gene expression.

Animals↗
PubMed1995

Cellular protein kinase C isoform zeta regulates human parainfluenza virus type 3 replication.

Phosphorylation of the P proteins of nonsegmented negative-strand RNA viruses is critical for their function as transactivators of the viral RNA polymerases. Using unphosphorylated P protein of human parainfluenza virus type 3 (HPIV3) expressed in Escherichia coli, we have shown that the cellular protein kinase that phosphorylates P in vitro is biochemically and immunologically indistinguishable from cellular protein kinase C isoform zeta (PKC-zeta). Further, PKC-zeta is specifically packaged within the progeny HPIV3 virions and remains tightly associated with the ribonucleoprotein complex. The P protein seems also to be phosphorylated intracellularly by PKC-zeta, as shown by the similar protease digestion pattern of the in vitro and in vivo phosphorylated P proteins. The growth of HPIV3 in CV-1 cells is completely abrogated when a PKC-zeta-specific inhibitor pseudosubstrate peptide was delivered into cells. These data indicate that PKC-zeta plays an important role in HPIV3 gene expression by phosphorylating P protein, thus providing an opportunity to develop antiviral agents against an important human pathogen.

Animals↗
PubMed1995

Efficient interaction of the vesicular stomatitis virus P protein with the L protein or the N protein in cells expressing the recombinant proteins.

Specific in vivo interaction between the phosphoprotein (P) and the large polymerase protein (L) from the Indiana serotype of vesicular stomatitis virus was studied using a two-hybrid system. Transfection of CHO cells with plasmids encoding GALPIND and VPLIND fusion proteins resulted in an easily detectable level of CAT activity, indicating that PIND and LIND associate in vivo in the absence of other viral proteins. Mutational studies of PIND demonstrated that both domains I and II of PIND are important for PIND-LIND association. In addition, casein kinase II (CKII)-mediated phosphorylation within domain I of PIND was necessary for efficient association with LIND. We have also used the two-hybrid system to show PIND interaction with NIND in vivo. PIND and NIND associated more strongly than PIND and LIND. A similar strong association was observed in heterologous interaction studies between Indiana and New Jersey serotype P and N proteins. Mutational studies of PIND demonstrated that, unlike what was found for PNJ-NNJ association, only the C-terminal region of the P protein was important for efficient association with NIND. Like PNJ, CKII-mediated phosphorylation within domain I of PIND was not required for P-N association and, like NNJ, the C-terminal five amino acids of the NIND protein were critical for P association with N. These results demonstrate the importance of phosphorylation and specific domains of the P protein in its interaction with the L and N proteins, which are necessary for viral transcription and replication, respectively.

Amino Acid Sequence↗