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Biomedical subjects

A Banerjee

Publications and source records attributed to A Banerjee.

At least 109 records · Page 6Linked to original sources
PubMed2000

Bronchoscopic photodynamic diagnosis and therapy for lung cancer.

Photodynamic diagnosis and therapy have exciting potential in lung cancer management. Fluorescence bronchoscopy enhances the detection of preinvasive lesions and early invasive carcinomas involving the central airways, whereas photodynamic therapy (PDT) provides an effective method for treating these lesions with preservation of lung tissue. However, the natural history of preinvasive lesions is poorly understood and so the value of treatment remains unclear. Although treatment for early invasive carcinomas'is not open to question, the possibility of undetected nodal disease means that PDT is unlikely to replace surgical resection in patients who are fit for thoracotomy. PDT also provides an effective method of palliating patients with advanced obstructing endobronchial tumors. Although it is considered superior to simple tumor debulking, its usefulness is limited by transient but potentially severe skin photosensitivity. There is therefore a need to develop new photosensitizing drugs with less severe side effects.

Bronchoscopy↗
PubMed2000

tert-butyl N-[2-[N-(N, N'-dicyclohexylureidocarbonylethyl)carbamoyl]prop-2-yl]carbamate.

The title compound, C(25)H(44)N(4)O(5), exhibits a turn with the main chain reversing direction, held together by an intramolecular N-H.O hydrogen bond. In the urea fragment, a notable amide C-N bond between the carboxyl C and the tertiary N atom shows marked single-bond character [1.437 (2) A]. The dihedral angle of the beta-alanyl residue, centrally located in the turn, is gauche [69.2 (2) degrees ]. The packing is mediated by two intermolecular hydrogen bonds and van der Waals contacts involving the methyl moieties and the cyclohexyl rings.

Crystallography, X-Ray↗
PubMed2000

Bench to bedside: tumor necrosis factor-alpha: from inflammation to resuscitation.

Proinflammatory mediators such as tumor necrosis factor-alpha (TNF) have been implicated in the pathophysiology in a number of acute disease states. Tumor necrosis factor-alpha can contribute to cell death, apoptosis, and organ dysfunction. Tumor necrosis factor-alpha can be generated with sepsis or ischemia-reperfusion by activation of cell mitogen-activated protein kinases and nuclear factor kappa B, leading to TNF production. A number of strategies to modulate TNF have been recently explored, including factors directed toward mitogen-activated protein kinases, TNF transcription, anti-inflammatory ligands, heat shock proteins, and TNF-binding proteins. However, TNF may also play an important role in the adaptive response to injury and inflammation. Control of the deleterious effects of TNF and other proinflammatory cytokines represents a realistic goal for clinical emergency medicine. The purpose of this article is to provide a background of relevance to emergency medicine academicians on the production and regulation of TNF, the acute effects of TNF on pathophysiology, and the rationale for therapeutic interventions directed toward TNF and the clinical experience with these strategies.

Apoptosis↗
PubMed2000

Effect of alpha-oligosaccharide phenotype of Neisseria gonorrhoeae strain MS11 on invasion of Chang conjunctival, HEC-1-B endometrial, and ME-180 cervical cells.

The genes encoding the glycosyltransferases responsible for the addition of the five sugars in the alpha-oligosaccharide (alpha-OS) moiety of lipooligosaccharide (LOS) have been identified. Disruption of these glycosyltransferase genes singly or in combination results in corresponding truncations in LOS. In the present work we show that sequential deletion of the terminal four sugar residues of gonococcal alpha-OS had no discernible effect on the invasion of human conjunctival, endometrial, and cervical cell lines. However, deletion of the proximal glucose, which resulted in the complete deletion of alpha-OS, significantly impaired invasion of the gonococci into all three cell lines. The effect of deleting alpha-OS on invasion was independent of and additive to the known invasion-promoting factor OpaA. These data suggest that the proximal glucose residue of the alpha-OS chain of LOS is required for efficient invasion of gonococci into host mucosa.

Cells, Cultured↗
PubMed2000

Laser palatoplasty: evaluation of patient benefit using the Glasgow benefit inventory.

Short-term results of laser palatoplasty have been encouraging. This study was undertaken to evaluate if there is a deterioration of benefit with time as seen in uvulopalatopharyngoplasty (UPPP). The Glasgow benefit inventory (GBI) was applied retrospectively by means of a postal questionnaire to measure the quality of benefit and to evaluate any deterioration in benefit with increasing post-operative time. Our results show that laser palatoplasty benefited 53 per cent of patients. With increasing post-operative time there was a decrease in the percentage of patients who felt the operation had made no difference, with a corresponding increase in the percentage of patients who felt worse. Although the number of patients who benefited remained fairly constant, there was deterioration in the quality of benefit in the first year, after which the benefit remained stable. This has implications in the pre-operative counselling of patients.

Adult↗
PubMed2000

Identification of a ubiquitination-Target/Substrate-interaction domain of cytochrome P-450 (CYP) 2E1.

Cytochrome P-450 (CYP) 2E1, the alcohol-inducible form of CYP, metabolizes a wide variety of endogenous substrates, therapeutic agents, protoxicants, and procarcinogens. CYP2E1 levels are post-transcriptionally elevated in response to certain xenobiotic inducers (e.g., pyridine), and proposed mechanisms include increased translational efficiency and protection of the enzyme from ubiquitin-dependent proteolysis. Molecular modeling of a predicted cytosolic domain of CYP2E1 resulted in identification of a putative ubiquitination-target/substrate-interaction structure (residues 317-340). An affinity-purified antibody reactive to this domain quenched CYP2E1 ubiquitination in a concentration-dependent manner in a rabbit reticulocyte lysate-based ubiquitination assay. The same antibody also inhibited rat liver microsomal chlorzoxazone 6-hydroxylase activity, a marker of CYP2E1 catalytic activity, in an equivalent concentration-dependent manner. These two observations suggest an association between the CYP2E1 cytosolic domain involved in catalysis and its serving as a target for ubiquitination. Thus, these results provide a plausible mechanistic explanation for the observation that substrate binding shields the CYP2E1 protein from turnover by the ubiquitin-proteasome-dependent machinery.

Amino Acid Sequence↗
PubMed2000

Screening tuberculosis suspects using two sputum smears.

SETTING: Ntcheu district hospital, Malawi. OBJECTIVE: To assess a screening strategy for tuberculosis (TB) suspects using two sputum smears. DESIGN: A strategy of screening all TB suspects with two sputum smears for 6 months (1 July-31 December 1998) was compared with the period 1 January to 30 June 1998 during which the strategy of screening TB suspects with three sputum smears was in use. All chest radiographs of patients with negative sputum smears were assessed, and in those with pulmonary cavities and extensive disease a third sputum smear was examined. Data were collected from the laboratory sputum register and the TB register. The two 6-month periods were compared. RESULTS: In the laboratory register, using a two-sputum strategy, 186 (16%) of 1152 TB suspects were smear-positive, a result that was no different than when the three-sputum strategy was used, where 173 (16%) of 1106 TB suspects were smear-positive. The clinical pattern of TB using the different screening strategies was similar, with 58% of registered patients smear-positive with the two-sputum strategy and 54% smear-positive with the three-sputum strategy. In the first 6 months 3177 sputum smears were examined compared to 2266 smears in the second 6 months, a 29% reduction in the number of smears examined. The cost of consumables using the strategy of three sputum smears was USD $731 compared with USD $521 using the strategy of two sputum smears. C O N C L U S I O N S: Screening TB suspects using two sputum smears is as effective as screening using three sputum smears, and is associated with less laboratory work and savings in costs.

Cost Control↗
PubMed2000

Viability of stored sputum specimens for smear microscopy and culture.

A laboratory study was performed to determine how long sputum specimens from smear-positive tuberculosis patients can be stored at room temperature or in the refrigerator and retain a positive acid-fast bacilli (AFB) smear or a positive mycobacterial culture. Sputum samples from 30 patients were examined up to 4 weeks and samples from 13 patients examined up to 8 weeks. Provided samples had not dried out, all sputum smears remained AFB positive up to 4 and 8 weeks. In both patient groups, at 4 weeks 37-39% of specimens at room temperature grew mycobacteria compared with 54-67% of specimens stored in the refrigerator. These results have implications for tuberculosis programme policy.

Bacteriological Techniques↗
PubMed2000

Care seeking behaviour and diagnostic processes in patients with smear-positive pulmonary tuberculosis in Malawi.

SETTING: Government hospitals in five districts in Malawi. OBJECTIVE: To determine care seeking behaviour and diagnostic processes in patients newly diagnosed with smear-positive pulmonary tuberculosis (PTB). DESIGN: Structured questionnaires completed by interview between January to September 1998. RESULTS: During the study period 1,518 patients were registered with PTB, of whom 1,099 (72%) were interviewed. The median delay between onset of cough and diagnosis was 8 weeks. There was a variable pattern of care seeking behaviour, with 70% of patients initially visiting a place of orthodox medical care and 30% visiting traditional healers, grocery shops, etc. Of these, 867 (79%) patients had one or more subsequent contacts for help, with these visits targeted more to orthodox medical care. At all stages, antibiotics resulted in symptomatic improvement in up to 40% of cases. There was a median time of 7 weeks between cough and first submission of sputum specimens. Almost all patients received sputum smear results after a median length of 4 days; 474 (43%) of patients were only aware of their diagnosis at the time of receiving smear results, this observation being significantly associated with lack of schooling and not knowing another person with TB. CONCLUSION: More needs to be done to educate communities and non-orthodox care providers about the diagnosis and treatment of TB.

Adolescent↗
PubMed2000

Evaluation of a unified treatment regimen for all new cases of tuberculosis using guardian-based supervision.

SETTING: Ntcheu District, Malawi, using an oral antituberculosis treatment regimen. OBJECTIVE: To determine whether directly observed treatment (DOT) during the initial phase of treatment supervised either in hospital, at health centres or by guardians in the community, was associated with 1) satisfactory 2-month and 8-month treatment outcomes, and 2) with a reduction of in-patient hospital-bed days. DESIGN: Prospective data collection of all tuberculosis (TB) patients registered between 1 April 1996 and 30 June 1997, with 2-month and 8-month treatment outcomes, sputum smear conversion in smear-positive pulmonary TB patients (PTB) and in-patient hospital-bed days. RESULTS: Among the 600 new patients, 302 had smear-positive PTB, 150 smear-negative PTB and 148 extrapulmonary TB (EPTB). Eight-month treatment completion was 65% for smear-positive PTB patients, which was significantly higher than in patients with smear-negative PTB (45%) and EPTB (54%), due mainly to high 8-month mortality rates. The site of the intensive phase was determined in 596 patients: 178 (30%) received DOT from guardians, 115 (19%) from a health centre and 303 (51%) in hospital. At 2 months, mortality rates were significantly higher in hospitalised patients. Two-month treatment outcomes (including sputum smear conversion rates in smear-positive PTB patients) were similar between patients receiving DOT at health centres or from guardians. Decentralised DOT resulted in a 25% reduction in hospital-bed days in patients alive at 2 months compared with that predicted using the old regimens. CONCLUSION: Decentralising DOT to health centres and to guardians during the intensive phase is associated with satisfactory treatment outcomes.

Administration, Oral↗
PubMed2000

Palliative balloon pulmonary valvuloplasty in tetralogy of fallot: echocardiographic predictors of successful outcome.

Although balloon pulmonary valvuloplasty (BPV) has been advocated as a means of palliating patients with tetralogy of Fallot (TOF), the results of this procedure were not uniformly good in this patient population. The purpose of this study was to review our institutionOs experience with BPV in patients with TOF, and to determine whether echocardiographic criteria exist that may be used to identify patients likely to derive prolonged benefit from this procedure. Between 1991 and 1999, nine patients with TOF, ages 0. 4Eth 26.1 weeks (mean, 7.4 +/- 7.6 weeks) underwent BPV due to cyanosis and other associated medical conditions (e.g., coronary artery anomalies, small size) that rendered immediate surgical intervention undesirable. Data from the catheterization and pre-BPV echocardiograms were analyzed. All patients had at least transient improvement in oxygen saturation. However, 4 patients (Group 1) required intervention (1 open-heart repair, 3 palliative shunts) within 5 weeks of BPV due to recurrent desaturation. In the remaining 5 patients (Group 2), open-heart repair was delayed 8Eth 36 weeks (mean, 23 +/- 13 weeks). Groups 1 and 2 did not differ regarding pulmonary valve annulus, main pulmonary artery or branch pulmonary artery diameter. However, the diastolic diameter of the right ventricular outflow tract (RVOT) was significantly smaller in Group 1 (18.3 +/- 3.5 mm/m2 versus 24.4 +/- 4.1 mm/m2 in Group 2; p < 0.05). Four out of five patients with a RVOT diameter < 23 mm/m2 were in Group 1, and all patients with RVOT diameter greater than 25 mm/m2 were in Group 2. We conclude that BPV can effectively palliate patients with TOF whose RVOT diastolic diameter is > 25 mm/m2. However, patients with a diastolic RVOT diameter < 23 mm/m2 are unlikely to have sustained improvement following BPV.

Cardiac Catheterization↗
PubMed2000

Gender differences in relation to sputum submission and smear-positive pulmonary tuberculosis in Malawi.

OBJECTIVE: To examine gender differences in sputum submission and sputum smear positivity. METHODS: Laboratory registers in all diagnostic units in eight districts in Malawi were examined for the years 1995 and 1996. RESULTS: During a 12-month period (averaged between 1995 and 1996), 26,624 new TB suspects submitted sputum samples, 3282 of which (12.3%) were smear-positive. Significantly more males submitted sputum (52%) compared with females (48%), and significantly more males (53%) were smear-positive compared with females (47%, P < 0.05). Rates of sputum submission per 100,000 adults were also significantly higher for males (1203) than females (1032). CONCLUSION: In Malawi, fewer females are submitting sputum samples and are being diagnosed with smear-positive TB compared with males.

Adolescent↗
PubMed2000

Local perceptions of tuberculosis in a rural district in Malawi.

SETTING: Ntcheu district, Malawi. OBJECTIVE: To determine 1) the number of patients treated by traditional healers, 2) the type of diseases managed by them, 3) the perceived causes of these disease, and 4) how both patients and healers looked at tuberculosis (TB). DESIGN: In-depth interviews and structured questionnaires with traditional healers, and focus group discussions with TB patients and their guardians. RESULTS: Traditional healers recognized four main causes of disease, related to why the patient is sick rather than what the patient is suffering from. Two hundred and seventy-six traditional healers saw approximately 4600 patients a week, managing a variety of diseases, mainly of a chronic nature. Twenty-four per cent of patients seen by traditional healers had a cough, including patients with TB. Traditional healers believe they can cure TB, and have therefore been briefed on the infectious form of TB (smear-positive cases). The possibility of including traditional healers in early diagnosis has been explored. CONCLUSION: There is a need to address local beliefs in health education and possibly find ways of involving healers in supervision of treatment.

Focus Groups↗