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Biomedical subjects

A Banerjee

Publications and source records attributed to A Banerjee.

At least 37 records · Page 2Linked to original sources

Hepatitis B virus genotype D infection among antenatal patients attending a maternity hospital in Calcutta, India: assessment of infectivity status.

A seroepidemiological study was conducted to determine the hepatitis B virus carrier rate and infectivity status among antenatal patients in Calcutta. Fifteen of 400 antenatal mothers (3.74%) were carriers of HBV genotype D. Four (1.0%) of them were positive for HBeAg with a high risk of transmitting infection to their babies. The presence of precore mutant HBV, which has been associated with transmission events from HBeAg mothers to their babies, was not detected in any of the HBeAg negative mothers.

Biomarkers↗

An in vitro investigation of microtensile bond strengths of two dentine adhesives to caries-affected dentine.

OBJECTIVES: To compare the micro-tensile bond strengths of two different adhesive systems (ABF (Clearfil Protect Bond), Kuraray Medical Inc., Tokyo, Japan) and Prime & Bond NT (PBNT, Dentsply, Konstanz, Germany) bonded to caries-affected dentine retained after chemo-mechanical caries removal using Carisolv gel, with that retained after excavation using conventional hand instrumentation. METHOD: Twenty, adult, human extracted carious teeth were used in this split tooth study with bur-cut cavities in sound dentine acting as controls. After clinical caries excavation, the occlusal cavities in each experimental group were restored with either bonding system plus composite. Matchstick-shaped samples through the bond interfaces were sectioned and microtensile bond strengths recorded. Scanning electron microscopy (SEM) was used to ascertain the mode of failure at the restoration-dentine interface. RESULTS: Statistical analysis of the bond strength data showed that for the ABF group, there was no difference in bond strengths between the controls and Carisolv group but these values were significantly higher than those for the hand-excavated samples. PBNT samples showed no significant differences in any of the three test groups, with wider ranging data sets. SEM analysis indicated a variety of failures at the interface including cohesive failures within the caries-affected dentine itself. CONCLUSIONS: From the data generated by this study it could be concluded that microtensile bond strengths of PBNT/composite restorations to caries-affected dentine in clinical cavities were statistically comparable to those to sound dentine. In the ABF/composite restored group (self-etched), the use of conventional hand excavation appeared to weaken the bond strength to the remaining caries-affected dentine. However, the use of Carisolv gel excavation did not compromise bond strengths to caries-affected dentine in either group tested.

Adhesiveness↗

Formation of finite antiferromagnetic clusters and the effect of electronic phase separation in Pr0.5Ca0.5Mn0.975Al0.025O3.

We report the first experimental evidence of a magnetic phase arising due to the thermal blocking of antiferromagnetic clusters in the weakened charge and orbital ordered system Pr0.5Ca0.5Mn0.975Al0.025O3. The third order susceptibility (chi(3)) is used to differentiate this transition from a spin- or cluster-glass-like freezing mechanism. These clusters are found to be mesoscopic and robust to electronic phase separation which only enriches the antiphase domain walls with holes at the cost of the bulk, without changing the size of these clusters.

Journal Article↗

Recording the retruded contact position: a review of clinical techniques.

The retruded contact position (RCP) is an important maxillomandibular relation in restorative dentistry. This review will describe RCP and consider its importance and use in the restorative dental treatment of the dentate and edentulous subject. A comparative account of the various mandibular guidance methods used to obtain a RCP record will be presented, followed by recommendations for fixed and removable clinical prosthodontic practice.

Centric Relation↗

What effect does isoflurane have upon ciliary beat pattern: an in vivo study.

The effect of anaesthetic gases given via laryngeal mask on nasal ciliary beat pattern and frequency has not been studied. Anaesthetic gases such as isoflurane, halothane and enflurane are known to reduce ciliary beat frequency, but it is unknown whether they also cause cilia to beat in a dyskinetic fashion. Brush biopsies of nasal mucosa were taken pre- and post-anaesthesia with isoflurane, given via a laryngeal mask, from patients undergoing nasal surgery. The samples were observed by light microscopy, and high-speed digital video recordings were made to determine ciliary beat frequency. Using slow-motion playback, the ciliary beat pattern was scored for dysmotility, and the proportion of immotile cilia in the sample was determined. We found that ciliary beat frequency decreased significantly (P < 0.01) after exposure to isoflurane (10.24 Hz compared to 9.20 Hz). However, isoflurane did not alter the ciliary beat pattern or the proportion of immotile cilia.

Adolescent↗

Molecular analysis of the microflora associated with dental caries.

Molecular techniques have revealed many novel, presumed unculturable, taxa in oral infections. The aim of this study was to characterize the bacterial community of the middle and advancing front of carious dental lesions by cultural and molecular analyses. Samples were collected with a hand excavator from five teeth with carious lesions involving dentine. Samples were cultured on blood agar and Rogosa agar incubated in air plus 5% CO(2) and on fastidious anaerobe agar anaerobically. DNA was also extracted directly from the samples and 16S rRNA genes were amplified by PCR with universal primers. PCR products were singularized by cloning, and the cloned inserts and cultured isolates were identified by 16S rRNA gene sequence analysis. We identified 95 taxa among the 496 isolates and 1,577 clones sequenced; 44 taxa were detected by the molecular method alone; 31 taxa were previously undescribed. Only three taxa, Streptococcus mutans, Rothia dentocariosa, and an unnamed Propionibacterium sp., were found in all five samples. The predominant taxa by anaerobic cultivation were the novel Propionibacterium sp. (18%), Olsenella profusa (14%), and Lactobacillus rhamnosus (8%). The predominant taxa in the molecular analysis were Streptococcus mutans (16%), Lactobacillus gasseri/johnsonii (13%), and Lactobacillus rhamnosus (8%). There was no significant difference between the compositions of the microflora in the middle and advancing front samples (P < 0.05, Wilcoxon matched pairs, signed ranks test). In conclusion, combined cultural and molecular analyses have shown that a diverse bacterial community is found in dentinal caries and that numerous novel taxa are present.

Adult↗

Subdural haematoma: a complication of cochlear implantation.

Cochlear implants have transformed the treatment of sensorineural hearing loss. They have few major complications. The authors describe the case of a man fitted with a cochlear implant who suffered a postoperative subdural haematoma. The haematoma is thought to have been caused by bleeding from emissary veins opened by the drill passages used to anchor the sutures for the receiver/stimulator. The authors have abandoned tie down sutures in cochlear implants, preferring an appropriately deep well with squared-off rims, which would secure the implant in place. They have had no further complications of this nature.

Cochlear Implantation↗

Surgical applications of organ preconditioning.

In 1986, Murry et al. reported that brief periods of antecedent ischemia in dogs paradoxically reduced (rather than exacerbated) the size of myocardial infarcts created by subsequent prolonged ischemia. This fortuitous discovery, now termed "preconditioning", stimulated further investigation of the inherent adaptive mechanisms present in a variety of tissues and organs. In addition to ischemia, it is now recognized that a protective response can be initiated by multiple means including lipopolysaccharide, heat stress, exercise, adrenergic drugs and even noise. Furthermore, preconditioning protects not only against cell death but also against postischemic contractile dysfunction, stunning and arrhythmias. Despite the preponderance of animal studies demonstrating the benefits of preconditioning, its clinical application has been hampered by clinicians' hesitancy to intentionally subject patients to a noxious stress prior to a planned intervention. However, many of the intracellular signals responsible for the protective effect of preconditioning have been delineated, and pharmacologic manipulation of these signals can accomplish the same benefits. The existence of preconditioning in humans has been demonstrated in vitro and in small clinical trials, and targeted strategies that exploit this endogenous protective mechanism promise to broaden the therapeutic potential of organ preconditioning.

Angioplasty, Balloon, Coronary↗

Acceptability of traditional healers as directly observed treatment providers in tuberculosis control in a tribal area of Andhra Pradesh, India.

SETTING: Vizianagaram district of Andhra Pradesh, India, where 9% of the population is tribal. OBJECTIVE: To 1) examine traditional healers' (THs) diagnostic and treatment practices for tuberculosis (TB); 2) understand health-seeking behaviour for TB amongst tribal groups; 3) evaluate the acceptability of THs to public health workers; and 4) assess how THs can collaborate with the TB Programme. METHODS: In-depth interviews with 120 THs, 37 exit interviews and four focus group discussions with TB patients; interviews with eight non-governmental organisations (NGOs) and 38 public health staff. RESULTS: There were 18 THs per 1000 population. Of the 120 THs interviewed, 15 (13%) claimed to be TB specialists. Of the 72 healers aware of TB, 65 (90%) considered prolonged cough an important symptom and 53 (74%) believed that TB could be cured with allopathic drugs. THs felt collaboration was possible by directly observed treatment (DOT) providers (49, 68%), referring symptomatic individuals (54, 75%) and offering treatment for side effects (18, 25%). CONCLUSION: Involvement of THs in the TB Control Programme may improve services as they are a major health service provider in tribal areas and are acceptable as DOT providers to patients, public health providers and NGO workers.

Attitude of Health Personnel↗

Role of some factors on the breeding of JE vector Culex vishnui group.

Vector of JE, Culex vishnui group, prefer to breed in rice field. During the present study, roles of some factors like irrigation, manuring, pesticide application, rainfall, temperature and pH of the breeding water, depth of breeding water and height of paddy plants on breeding of Culex vishnui group larvae have been studied. It is evident from the study that besides striking role of the factors like manuring and pesticide application, other factors have also some role on the breeding of JE vectors at their breeding sites.

Agriculture↗

Chromosomal aberrations and sister chromatid exchanges in individuals exposed to arsenic through drinking water in West Bengal, India.

Arsenic contamination in groundwater has become a worldwide problem. Currently an unprecedented number of people in West Bengal, India and Bangladesh are exposed to the ubiquitous toxicant via drinking water in exposure levels far exceeding the maximum recommended limit laid down by WHO. This arsenic epidemic has devastated nine districts of West Bengal encompassing an area of 38,865 km(2) leading to various clinical manifestations of chronic arsenicosis. We conducted a human bio-monitoring study using chromosomal aberrations (CA) and sister chromatid exchanges (SCE) as end points to explore the cytogenetic effects of chronic arsenic toxicity in the population of North 24 Parganas, one of the arsenic affected districts in West Bengal. Study participants included 59 individuals residing in this district where the mean level (+/-S.E.) of arsenic in drinking water (microg/l) was 211.70+/-15.28. As age matched controls with similar socio-economic status we selected 36 healthy, asymptomatic individuals residing in two unaffected districts--Midnapur and Howrah where the mean arsenic content of water (microg/l) was 6.35+/-0.45. Exposure was assessed by standardized questionnaires and by detecting the levels of arsenic in drinking water, nails, hair and urine samples. In the exposed group the mean arsenic concentrations in nails (microg/g), hair (microg/g) and urine (microg/l) samples were 9.04+/-0.78, 5.63+/-0.38 and 140.52+/-8.82, respectively, which were significantly high (P<0.01) compared to the corresponding control values of 0.44+/-0.03, 0.30+/-0.02 and 5.91+/-0.49, respectively. Elevated mean values (P<0.01) of the percentage of aberrant cells (8.08%) and SCEs per cell (7.26) were also observed in the exposed individuals in comparison to controls (1.96% and 5.95, respectively). The enhanced rates of CAs and SCEs among the residents of North 24 Parganas are indicative of the cytogenetic damage due to long term exposure to arsenic through consumption of contaminated water.

Adolescent↗

Severe hypokalaemia and weakness due to Nurofen misuse.

Nephrotoxicity from non-steroidal anti-inflammatory drugs (NSAID) is well recognized. We report a case of severe hypokalaemia and weakness due to renal tubular acidosis in a young woman who was taking 40-60 tablets per day of Nurofen Plus (ibuprofen 200 mg and codeine phosphate 12.8 mg). Proprietary brands of ibuprofen are freely available to the public and those containing codeine may be potentially subject to abuse. This case highlights the need to be aware of this potential and of the life-threatening electrolyte and acid-base disturbances that might be encountered with the widespread availability of these types of NSAID.

Acidosis, Renal Tubular↗

Computed tomography in suppurative ear disease: does it influence management?

The value of high resolution computerized tomography (CT) prior to routine mastoid surgery for cholesteatoma remains controversial. Doubts about sensitivity and specificity, in detecting the extent of underlying pathology and in predicting asymptomatic complications, prevent widespread adoption. This retrospective study looks at the influence of pre-operative scanning on the surgical management of chronic suppurative otitis media over an 18-month period. The radiological findings determined the choice of surgical approach, but contributed less to the decision to operate and the prediction of potential hazards. CT is of most value when the otologist can be flexible in surgical technique, tailoring it to imaging findings.

Cholesteatoma↗

Annual risk of tuberculous infection in Khammam a tribal district of Andhra Pradesh.

A tuberculin survey to estimate annual risk of tuberculosis was conducted in Khammam tribal district during 2001-2002. A total of 8637 children were test-read--2991 without BCG scar and 5442 with BCG scar. The tests were performed using ITU PPD RT23 and the maximum size of induration was recorded at about 72 hours after the test. Based on the frequency distribution of reaction size, cut-off point for infection with tubercle bacilli was considered at 12 mm. Using this criterion, the prevalence of infection was estimated at 11.8% among children without BCG scar and 10.6% among children with BCG scar. This difference was found to be statistically insignificant. ARTI rates computed from the prevalence estimates among children without and with BCG scar were 1.6% and 1.5% respectively. It was computed as 1.5% from the prevalence in the combined group i.e. irrespective of BCG scar status.

Child↗

The nitrile-degrading enzymes: current status and future prospects.

Nitrile-converting enzymes are becoming commonplace in the synthesis of pharmaceuticals and commodity chemicals. These versatile biocatalysts have potential applications in different fields including synthetic biocatalysis and bioremediation. This review attempts to describe in detail the three major classes of nitrile-converting enzymes, namely nitrilases, nitrile hydratases and amidases. Various aspects of these enzymes including their occurrence, mechanism of action, characteristics and applicability in different sectors have been elaborately elucidated. Cloning of genes related to nitrile-converting enzymes is also discussed.

Amidohydrolases↗

Enhanced frequency of micronuclei in individuals exposed to arsenic through drinking water in West Bengal, India.

In West Bengal, India arsenic in ground water has been found to be above the maximum permissible limit in seven districts covering an area of 37,493km2. In the present study, evaluation of the micronuclei (MN) formation in oral mucosa cells, urothelial cells and peripheral blood lymphocytes was carried out in the symptomatic individuals exposed to arsenic through drinking water. Forty five individuals with cutaneous signs of arsenicism from four affected districts (368.11 microg/l of As in drinking water) were considered as the exposed group and 21 healthy individuals with no symptoms of arsenic poisoning and residing in two unaffected districts (5.49 microg/l of As) were considered as controls. The exposed and control groups had similar age distribution and socioeconomic status. Standardised questionnaires were utilised and medical examination was conducted to ascertain exposure history, sociodemographic characteristics, diet, health, medication, addiction and chief symptoms in the study participants. Arsenic exposure was confirmed by measuring the arsenic content in the drinking water, nails, hair and urine samples from the volunteers. Arsenic contents in the urine, nail and hair in the exposed group were 24.45 microg/l, 12.58 and 6.97 microg/g, respectively which were significantly high in comparison to corresponding control group values of 4.88 microg/l, 0.51 and 0.34 microg/g, respectively. Exposed individuals showed a statistically significant increase in the frequency of MN in oral mucosa, urothelial cells and lymphocytes (5.15, 5.74 and 6.39/1000 cells, respectively) when compared with the controls (0.77, 0.56 and 0.53/1000 cells, respectively). Thus, the above results indicate that the symptomatic individuals exposed to arsenic through drinking water in this region have significant cytogenetic damage.

Adolescent↗

Audit of stapedectomy results in a district general hospital.

We report a series of 100 stapes operations performed for otosclerosis. The problems in reporting the results of stapedectomies are discussed. The audit showed a difference in the measured results between two consultants. As a result, the consultant with the worse outcome chose to stop operating on patients with otosclerosis. The advantages and disadvantages of a single surgeon performing all the cases are discussed. We advocate a central registry of all surgeons performing stapes surgery to allow periodic national comparative audits.

Bone Conduction↗