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M Banerjee

Publications and source records attributed to M Banerjee.

At least 73 records · Page 4Linked to original sources
PubMed1997

Interpreting kappa values for two-observer nursing diagnosis data.

Reliability of nursing observations often is estimated using Cohen's kappa, a chance-adjusted measure of agreement between observer RNs. However, use of kappa as an omnibus measure sometimes can be misleading. In a study partly designed to describe the frequency and reliability of nursing diagnoses in long-term care facilities, 360 residents each were assessed independently by two registered nurses, and kappa and observed proportion of agreement were calculated as estimates of reliability. For some diagnoses we observed high proportions of agreement, yet paradoxically low kappa values. This article presents an in-depth statistical analysis to resolve this paradox. Results from our analysis also suggest means for planning improvements in the diagnostic performance of participating RNs. Consequently, our approach can be used in similar studies of diagnosis reliability to enhance nursing research, education, and practice.

Bias↗
PubMed1997

Genetic variation in Asiatic lions and Indian tigers.

Previous reports have suggested that Asiatic lions and tigers are highly inbred and exhibit very low levels of genetic variation. Our analyses on these species have shown much higher degrees of polymorphism than reported. Randomly amplified polymorphic DNA (RAPD) analysis of 38 Asiatic lions, which exist as a single population in the Gir Forest Sanctuary in India, shows an average heterozygosity of 25.82% with four primers. Sperm motility studies by our colleagues corroborate this data. In Indian tigers, microsatellite analysis of five CA repeat loci and multilocus fingerprinting using Bkm 2(8) probe on a population of 22 individuals revealed a heterozygosity of 22.65%. Microsatellite analysis of loci Fca 77 and Fca 126 revealed polymorphism amongst the Asiatic x African lion hybrids, which has enabled us to use these as markers to discriminate the pure Asiatic lions from the hybrids. A similar analysis was used to identify hybrids of Indian and Siberian tigers through polymerase chain reaction (PCR) amplification of hair samples. To ascertain the variation which existed before the population bottleneck at the turn of the present century, microsatellite analysis was performed on 50- to 125-year-old skin samples from museum specimens. Our results show similar levels of genetic variability as in the present population (21.01%). This suggests that low genetic variability may be the characteristic feature of these species and not the result of intensive inbreeding. DNA fingerprinting studies of Asiatic lions and tigers have helped in identifying individuals with high genetic variability which can be used for conservation breeding programs.

Animals↗
PubMed1997

Prognostic implications of a positive apical margin in radical prostatectomy specimens.

PURPOSE: We evaluated the prognostic implication of a positive surgical margin at the prostatic apex to define the risk of failure after radical prostatectomy. MATERIALS AND METHODS: Radical prostatectomy specimens of 590 patients operated on between 1990 and 1994 were reviewed by 2 uropathologists (D. G. and W. S.) to determine the percentage of patients with a positive margin at the apex in the absence of positive margins, extraprostatic extension or involvement of seminal vesicles and pelvic lymph nodes. In this group of 33 patients, the significance of a positive apex could be determined without the influence of any other stage related prognostic factors. Treatment failure was defined as prostate specific antigen greater than 0.4. All 33 patients have been followed between 3.5 and 65.5 months (median 38.7). RESULTS: Among 590 patients 236 (40%) had disease completely confined to the prostate. A total of 217 patients (37%) had either positive surgical margins (M+) or extraprostatic extension and of these, only 33 (5.5%) had an apical positive margin in an otherwise prostate confined tumor. Of 33 apical positive margin patients only 3 in whom surgery failed had progressively detectable prostate specific antigen 3.5 to 65.5 months after surgery. CONCLUSIONS: A positive surgical margin at the prostatic apex in the absence of positive margins or extraprostatic extension elsewhere does not confer a worse prognosis than organ confined disease. In this study the recurrence rate for patients with positive apical margins was the same as for those with confined disease.

Follow-Up Studies↗
PubMed1997

Incidence of urethral involvement in female bladder cancer: an anatomic pathologic study.

OBJECTIVES: To evaluate risk factors for urethral involvement in female patients undergoing cystectomy for bladder cancer and to define potential candidates for orthotopic continent urinary diversion. METHODS: From 1990 to 1996, 43 female patients underwent cystectomy for primary bladder malignancy. Bladder mapping studies were performed with special attention to tumor location, multifocality, pathologic stage and grade, presence of carcinoma in situ (CIS), and the relationship of these factors to urethral involvement. RESULTS: Of the 43 patients evaluated, 7 (16.3%) had urethral involvement by tumor. Two patterns of urethral invasion were identified: 5 patients had tumors in the vascular or lymphatic channels of the periurethral tissue, and 2 had tumors in the mucosa or submucosa. Three of the 12 patients with tumors located at the trigone and 4 of the 26 with CIS of the bladder had tumor in the urethra. Three of the 5 patients with vaginal involvement had tumor in the urethra. Only vaginal involvement was significantly associated with urethral involvement (P = 0.02). CONCLUSIONS: Vaginal involvement was the only preoperative factor that was associated with presence of tumor in the urethra. Five patients with urethral involvement had submucosal tumors without concomitant CIS of the urethra. Before the performance of orthotopic urinary diversions, intraoperative full-thickness bladder neck biopsies are needed to accurately evaluate the female urethra.

Cystectomy↗
PubMed1997

Localization of a 25 kDa human sperm surface protein: its role in in-vitro human sperm capacitation.

A human endometrial sialic acid-binding glycoprotein (SABP) binds specifically to a 25 kDa protein on the plasma membranes of human non-capacitated sperm heads. In-vitro labelling of the sperm surface sialoglycoconjugates and subsequent incubation with SABP, suggests removal of some sialoglycoconjugate moieties from the sperm surface upon interaction with SABP. SABP also induces the exposure of mannose ligand receptors on the sperm surface and increases the production of superoxide anion (O2-).

Binding Sites↗
PubMed1997

Presence of circulating prostate cells in the bone marrow of patients undergoing radical prostatectomy is predictive of disease-free survival.

PURPOSE: To determine whether the presence of circulating prostate cells in the bone marrow is associated with disease-free survival in patients undergoing radical prostatectomy. MATERIALS AND METHODS: We evaluated the bone marrow of 86 patients with clinically localized prostate cancer treated by radical prostatectomy for the presence of circulating prostate cells using reverse-transcriptase polymerase chain reaction (RT-PCR) amplification of prostate-specific antigen (PSA) mRNA. Follow-up duration ranged from 1 to 43 months (mean, 15.4). RESULTS: Two of 47 patients (4%) with negative RT-PCR PSA results and 10 of 39 patients (26%) with positive RT-PCR PSA results have had disease recurrence. Patients whose RT-PCR PSA results were positive had a significantly shorter disease-free survival period than those patients with negative RT-PCR PSA results (P = .004). RT-PCR status correlated significantly with serum PSA level (P = .001) and pathologic stage (P = .003). Based on Cox's proportional hazards models, RT-PCR status was found to be a significant predictor of disease-free survival. However, after controlling for PSA level, RT-PCR status was not significant in predicting disease-free survival. CONCLUSION: RT-PCR PSA of bone marrow may be a useful pretreatment prognostic test for patients undergoing radical prostatectomy. Currently, this test should not be used to determine if patients receive definitive local therapy.

Adenocarcinoma↗
PubMed1996

Polymerase chain reaction-based diagnosis of del (5q) in acute myeloid leukemia and myelodysplastic syndrome identifies a minimal deletion interval.

Loss of all or part of the long arm of human chromosome 5 is a recurrent abnormality in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), especially after chemotherapy for a prior malignancy. It is one of the worst prognostic indicators in AML, associated with chemotherapy resistance and short survival. These deletions center at band 5q31, which has thus been proposed as the location of a tumor suppressor gene; this site is to be distinguished from that observed in 5q- syndrome, centering at 5q32. To define the molecular extent and the clinical prevalence of 5q31 deletions, we collected a series of AML and MDS cases of mixed karyotype, taking care to exclude MDS cases with 5q- syndrome. The samples were analyzed for loss of heterozygosity (LOH) using a panel polymerase chain reaction (PCR)-based microsatellite markers from 5q, comparing malignant cells with normal tissue derived from lymphoblastoid cell lines or buccal mucosa scrapings. Losses were detected in seven of 29 matched samples, including four of 17 with MDS, and three of 12 with AML; six of these seven also had a cytogenetically-visible del(5q) or -5. The one case without a cytogenetic deletion showed molecular loss of three contiguous markers, with retention of flanking markers interleukin-9 (IL-9) and D5S414, and thus contained a small deletion that is below cytogenetic resolution. PCR failed to detect 5q loss in two cases with large cytogenetic deletions, but both had been treated and contained low percentages of malignant cells in the samples. This study thus led to the identification of a case with a minimal deletion for the 5q31 tumor suppressor gene, specified by IL-9-D5S414, that is approximately 1 Mb (2 cM) in extent. Additionally, we demonstrate that PCR-based allelotyping is a reliable method for the detection of chromosomal deletion in myeloid malignancy, providing the specimens contain a high proportion of malignant cells. These studies will help to identify the tumor-suppressor gene at 5q31, and will help to develop molecular methods for diagnosis and monitoring of these disorders.

Acute Disease↗
PubMed1996

Soluble phospholipids enhance factor Xa-catalyzed prothrombin activation in solution.

Acidic phospholipids play an important but incompletely understood role in prothrombin activation. Here we report the effect of short-chain phosphatidylserine (dicaproylphosphatidylserine, C6PS) and the corresponding phosphatidylglycerol (C6PG) and phosphatidylcholine (C6PC) derivatives on the rate of prothrombin activation by factor Xa. The critical micellar concentrations of these short-chained phospholipids have been determined under a variety of conditions that we used for kinetic and structural studies. Under conditions for which these lipids exist in a soluble form, the results demonstrate that: (i) the rate of human prothrombin activation by human factor Xa was enhanced in a calcium-dependent fashion up to 60-fold by addition of C6PS, roughly 20% of the optimal enhancement seen with bovine phosphatidylserine/palmitoyloleoylphosphatidylcholine (25/75 PS/POPC) membranes; (ii) C6PS inhibited the rate of hydrolysis of synthetic factor Xa substrate (S-2765), an effect that was mimicked, but at much lower lipid concentrations, by PS/POPC membranes; (iii) there was no enhancement of prothrombin activation and much less inhibition of hydrolysis of S-2765 by factor Xa in the presence of C6PG or C6PC; and (iv) the thermal denaturation of prothrombin was altered in a calcium-independent but dose-dependent fashion by either C6PS or C6PG. These results have been interpreted in terms of the existence of (a) specific PS binding site(s) on factor Xa (Kd approximately 73 microM) that regulate(s) the activity of this serine protease. Our results do not rule out the possibility that the rate of prothrombin activation is also influenced by a weaker, calcium-independent, and less specific acidic lipid binding site on prothrombin, the occupancy of which results in conformational changes in this protein. The results clearly suggest that PS binding regulates the rate of prothrombin activation.

Animals↗
PubMed1996

c-myc oncogene expression and cell proliferation in mixed oligo-astrocytoma.

Mixed gliomas (oligo-astrocytomas) are brain tumours with an admixture of 2 different cell populations: astrocytes and oligodendroglia. On the basis of histological features and behaviour, these tumours are classified as low-grade mixed gliomas (MG) and malignant mixed gliomas (MMG). We have studied the relationship between c-myc protein expression and cellular proliferation in this class of tumours. Using antibody c-33 for c-myc and PC-10 for the proliferating cell nuclear antigen (PCNA), immunohistochemistry was performed on 14 MG and 9 MMG. PCNA was increased in MMG as compared to MG in both astrocytic and oligodendroglial areas. However, more c-myc-positive cells were seen only in the astrocyte areas of MMG. Analysis of the relationship of c-myc and PCNA suggests that the correlation of c-myc with cellular proliferation is dependent on tissue type and differentiation status.

Antibodies, Monoclonal↗
PubMed1996

The Mu strong gyrase-binding site promotes efficient synapsis of the prophage termini.

A strong DNA gyrase-binding site (SGS) is located midway between the termini of the bacteriophage Mu genome and is required for efficient replicative transposition. We have proposed that the SGS promotes the efficient synapsis of the Mu prophage ends (an obligate early step in replicative transposition), and that it does so by helping to organize the prophage DNA into a supercoiled loop with the SGS at the apex of the loop and the prophage termini at the base. The positioning of the synapsing termini equidistant from the SGS is a key element in the proposed model. To test this proposal, we have constructed prophages with a second, internal right end and asked whether the natural, external right end or the internal right end is used for synapsis with the left end in the presence and absence of the SGS. In the presence of the central SGS, the natural, or outside, right end was used exclusively and very efficiently. In the absence of the central SGS, the internal right end was used preferentially and inefficiently: the efficiency of transposition decreased with increasing distance between the internal right end and the left end. Repositioning the SGS midway between the left end and an internal right end allowed highly efficient use of the internal right end. These results support a model in which gyrase can influence long-range DNA interactions to promote efficient synapsis of Mu prophage ends.

Bacteriolysis↗
PubMed1996

A novel Ty1-mediated fragmentation method for native and artificial yeast chromosomes reveals that the mouse steel gene is a hotspot for Ty1 integration.

We have developed a powerful new tool for the physical analysis of genomes called Ty1-mediated chromosomal fragmentation and have used the method to map 24-retrotransposon insertions into two different mouse-derived yeast artificial chromosomes (YACs). Expression of a plasmid-encoded GAL1:Ty1 fusion element marked with the retrotransposition indicator gene, ade2AI, resulted in a high fraction of cells that sustained a single Ty1 insertion marked with ADE2. Strains in which Ty1ADE2 inserted into a YAC were identified by cosegregation of the ADE2 gene with the URA3-marked YAC. Ty1ADE2 elements also carried a site for the endonuclease I-DmoI, which we demonstrate is not present anywhere in the yeast genome. Consequently, I-DmoI cleaved a single chromosome or YAC at the unique site of Ty1ADE2 insertion, allowing rapid mapping of integration events. Our analyses showed that the frequency of Ty1ADE2 integration into YACs is equivalent to or higher than that expected based on random insertion. Remarkably, the 50-kb transcription unit of the mouse Steel locus was shown to be a highly significant hotspot for Ty1 integration. The accessibility of mammalian transcription units to Ty1 insertion stands in contrast to that of yeast transcription units.

Animals↗
PubMed1996

Nitric oxide and nitroglycerin reversal of pulmonary vasoconstriction induced by alpha-activation during exercise.

We have previously shown in sheep that pulmonary vascular resistance decreases rapidly after the onset of constant exercise, followed by a slower and smaller second vasodilation. The second phase is partly regulated by alpha- and beta-adrenoceptor activation. We examined the effect of inhaled nitric oxide (NO; 40 ppm) and intravenous nitroglycerin on beta-adrenergic blockade-induced pulmonary vasoconstriction during exercise. In paired studies, we exercised eight sheep at a constant rate of 4 miles per hour for 4 min on a treadmill and measured the hemodynamic response during beta-blockade (propranolol, 1 mg i.v.) with and without 40 ppm inhaled NO or continuous infusion of nitroglycerin (3.2-4.0 micrograms.kg-1.min-1). beta-Blockade resulted in a higher pulmonary vascular resistance during steady-state exercise (40-240 s) than in the unblocked state; reduction in pulmonary vascular resistance during the second phase of exercise was smaller with beta-blockade (13-16%) than with control exercise (26-30%). Inhaled NO and nitroglycerin reversed the beta-blockade-related pulmonary vasoconstriction to the levels of control exercise. Inhaled NO and intravenous nitroglycerin also reversed the pulmonary vasoconstriction produced by intravenous phenylephrine at rest. We conclude that exogenous NO, delivered by gas inhalation or via nitroso compounds, opposes and fully reverses alpha-receptor-activated pulmonary vasoconstriction during exercise in sheep.

Administration, Inhalation↗
PubMed1996

PGF2 alpha causes bronchoconstriction and pulmonary vasoconstriction via thromboxane receptors in rat lung.

We determined the vascular and airway effects of PGF2 alpha and its mechanism of action on isolated-perfused lungs of rats were isolated and perfused at 50 ml/kg/min with Krebs-Henseleit bicarbonate buffer solution containing 3% bovine serum albumin. The lungs were ventilated with 21% O2 and 5% CO2 at a tidal volume of 2 ml. frequency of 60 per minute and positive end expiratory pressure of 3 cmH2O. Following injection of 50 micrograms PGF2 alpha into the afferent pulmonary catheter, there was a marked rise in pulmonary arterial pressure (Ppa) and in resistance to airflow across the lung (RL) and a fall in dynamic lung compliance (Cdyn). Double vascular occlusion technique revealed that 29% of the rise in Ppa was due to an increase in upstream and 71% to downstream resistance. N omega-nitro-L-arginine, 100 microns, a NO synthase inhibitor potentiated the Ppa response two-fold with significant change in airway mechanics. Rat atrial natriuretic factor (r-ANF), 40 micrograms quickly reversed the changes in Ppa, RL and Cdyn. Infusion of r-ANF prior to PGF2 alpha attenuated the Ppa response by 38%, RL by 44% and Cdyn by 12%. SQ 29548, a thromboxane receptor blocker and Cl, a protein kinase C (PKC) inhibitor, fully blocked both the vascular and airway responses to PGF2 alpha. PGF2 alpha is a constrictor of pulmonary vessels and airways in rat lungs via thromboxane SQ 29548 receptors, thansduced by intracellular PKC.

Animals↗
PubMed1995

Infrequent alteration of the c-myc gene in human glial tumours associated with increased numbers of c-myc positive cells.

Twenty five human glial tumours of different grades of malignancy were examined by Southern blotting and polymerase chain reaction (PCR) for alterations (rearrangements, amplification and deletions) in the c-myc gene. Number of c-myc positive cells per thousand cells were also counted in all the tumours after immunohistochemical staining for c-myc protein was done on fixed sections of the tumours. No tumours exhibited any amplification of the gene, as found by Southern blotting. One astrocytoma and one mixed glioma showed some rearrangements in the 3' end of the gene, as detected by Southern blotting and hydridization. These two tumours had higher number of c-myc positive cells than in other tumours of the same histopathological groups. Deletion in the first promoter region, as determined by PCR, was seen in only one astrocytoma. However, the number of c-myc positive cells in that tumour did not show any deviation from that found in other astrocytomas. In light of present literature, it is speculated that the 3' rearrangements may be the cause of increased number of c-myc immunopositive cells in those tumours by disrupting the 3' end of the gene leading to increased c-myc mRNA stability. Such a mechanism may play a part in small subset of glial and possibly other tumours.

Base Sequence↗
PubMed1995

Induction of capacitation in human spermatozoa in vitro by an endometrial sialic acid-binding protein.

A Ca(2+)-dependent sialic acid-binding protein (SABP) of human endometrium, which specifically bound to human sperm head plasma membrane in vitro, was found to increase the percentage motility and acrosome-reacted pattern of uncapacitated spermatozoa. The protein was synthesized in the endometrium and secreted into the uterine fluid. This intra-uterine factor, which is apparently advantageous in vitro in inducing human sperm capacitation, may play a significant role in promoting the post-release maturation of ejaculated spermatozoa by enhancing 45Ca uptake into spermatozoa by a pathway which is insensitive to calcium-channel blockers. However, the 45Ca uptake could be enhanced on exposure to the divalent cation ionophore A23187 and inhibited in the presence of the calmodulin inhibitor trifluoperazine. The SABP also induces an increase in intracellular Ca2+ in spermatozoa, as seen by FURA-2 AM studies. Furthermore, overlay studies show human SABP to be a Ca(2+)-binding protein. The data presented here suggest that SABP induces in-vitro sperm capacitation and the subsequent acrosome reaction by increasing intracellular Ca2+ concentration.

Agglutinins↗