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Biomedical subjects

D Roy

Publications and source records attributed to D Roy.

At least 37 records · Page 2Linked to original sources
PubMed2004

Genetic and morphological data supporting the hypothesis of adaptive radiation in the endemic fish of Lake Matano.

Adaptive radiation resulting from differential selection acting on functional features is believed to be an important source of biodiversity. In this study, morphometric measures and mitochondrial DNA are used to test for adaptive radiation within four fish genera (Glossogobius, Oryzias, Dermogenys and Telmatherina) endemic to an ancient island lake (Lake Matano, Sulawesi, Indonesia), using the framework proposed by Schluter (The Ecology of Adaptive Radiation, Oxford University Press, 2000). We demonstrate common ancestry and rapid divergence in one genus (Telmatherina) based on 560 bp of 16S sequence data. We found higher levels of variation in feeding-related traits (N = 8) for Telmatherina relative to the other genera, while no differences were found for sexual display traits (N = 8) or neutral morphological traits (N = 8). Telmatherina also had the highest number of distinct colouration patterns among the four genera. These data, combined with the very low productivity of the lake, are indicative of selection driving adaptive radiation. The morphometric divergence in the Telmatherina likely results from selection acting on feeding traits in this low productivity lake, leading to trophic specialization among closely related morphotypes. These results provide indirect but compelling data supporting the adaptive radiation of Telmatherina in this system.

Adaptation, Biological↗
PubMed2004

Trigeminal autonomic cephalgias and variants: clinical profile in Indian patients.

The present study summarizes the authors' experience of the clinical profile of short-lasting trigeminal autonomic cephalgias (TAC) in Indian patients. Over a period of 17 years a total of 41 cases of episodic cluster headache, seven cases of chronic cluster headache, six cases of variant cluster headache, three cases of paroxysomal hemicrania, and a single case of SUNCT syndrome were encountered. TACs appear to be rare in Indian patients and cluster headache seems to be exclusively a disease of men. The present report is to the best of our knowledge the first of its kind to be reported from India.

Adult↗
PubMed2004

Identification of the bacterial community of maple sap by using amplified ribosomal DNA (rDNA) restriction analysis and rDNA sequencing.

The bacterial community of maple sap was characterized by analysis of samples obtained at the taphole of maple trees for the 2001 and 2002 seasons. Among the 190 bacterial isolates, 32 groups were formed according to the similarity of the banding patterns obtained by amplified ribosomal DNA restriction analysis (ARDRA). A subset of representative isolates for each ARDRA group was identified by 16S rRNA gene fragment sequencing. Results showed a wide variety of organisms, with 22 different genera encountered. Pseudomonas and Ralstonia, of the gamma- and beta-Proteobacteria, respectively, were the most frequently encountered genera. Gram-positive bacteria were also observed, and Staphylococcus, Plantibacter, and Bacillus were the most highly represented genera. The sampling period corresponding to 50% of the cumulative sap flow percentage presented the greatest bacterial diversity according to its Shannon diversity index value (1.1). gamma-Proteobacteria were found to be dominant almost from the beginning of the season to the end. These results are providing interesting insights on maple sap microflora that will be useful for further investigation related to microbial contamination and quality of maple products and also for guiding new strategies on taphole contamination control.

Acer↗
PubMed2004

Role of "Ischemia modified albumin", a new biochemical marker of myocardial ischaemia, in the early diagnosis of acute coronary syndromes.

BACKGROUND: Diagnosis of cardiac ischaemia in patients attending emergency departments (ED) with symptoms of acute coronary syndromes is often difficult. Cardiac troponin (cTn) is sensitive and specific for the detection of myocardial damage but may not rise during reversible myocardial ischaemia. Ischemia Modified Albumin (IMA) has recently been shown to be a sensitive and early biochemical marker of ischaemia. METHODS AND RESULTS: This study evaluated IMA in conjunction with ECG and cTn in 208 patients presenting to the ED within three hours of acute chest pain. At presentation, a 12-lead ECG was recorded and blood taken for IMA and cardiac troponin T (cTnT). Patients underwent standardised triage, diagnostic procedures, and treatment. Results of IMA, ECG, and cTnT, alone and in combination, were correlated with final diagnoses of non-ischaemic chest pain, unstable angina, ST segment elevation, and non-ST segment elevation myocardial infarction. In the whole patient group, sensitivity of IMA at presentation for an ischaemic origin of chest pain was 82%, compared with 45% of ECG and 20% of cTnT. IMA used together with cTnT or ECG, had a sensitivity of 90% and 92%, respectively. All three tests combined identified 95% of patients whose chest pain was attributable to ischaemic heart disease. In patients with unstable angina, sensitivity of IMA used alone was equivalent to that of IMA and ECG combined. CONCLUSIONS: IMA is highly sensitive for the diagnosis of myocardial ischaemia in patients presenting with symptoms of acute chest pain.

Adult↗
PubMed2004

Mucormycosis--early diagnosis and treatment.

OBJECTIVE: The aim of this retrospective study was to analyse the data of patients with rhino-orbital-cerebral mucormycosis for predisposing factors, diagnosis, treatment and survival rate. The role of frozen section in early diagnosis and use of nasal endoscopy in diagnosis, treatment and follow-up of patients has also been examined. DESIGN: Retrospective case series. SETTING: University Teaching Hospital. METHODS: The case notes of 9 patients with diagnosis of mucormycosis who presented from 1973 to 2001 were examined. The data for predisposing factors, signs/symptoms, histological diagnosis, radiological intervention, medical and surgical treatment and final outcome was analysed. RESULTS: There were 9 patients with mucormycoses. Early diagnosis was made by endoscopic examination and frozen section in 5 patients, which was later confirmed by histology. Treatment included parental and/or local amphotericin, hyperbaric oxygen and debridement either by endoscopic or external approach, with or without orbital exenteration. This resulted in an overall survival of 5 patients. CONCLUSION: Frozen section diagnosis allows for early therapy since successful treatment depends on systemic amphotericin, surgical debridement and treatment of underlying predisposing factors. Nasal endoscopy is useful in diagnosis, endoscopic debridement and follow up of patients.

Adult↗
PubMed2003

Endovascular stenting of the transverse sinus in a patient presenting with benign intracranial hypertension.

The authors present a 37-year-old lady with symptoms and signs suggestive of benign intracranial hypertension (BIH). Routine CT and MRI scans were normal. Further investigations were performed with magnetic resonance venography (MRV) and cerebral venography. These revealed obstruction of the right transverse sinus with high pressure (40 mmHg) proximal to the obstruction and low pressure (15 mmHg) distally. She was treated by transvenous stent deployment with resolution of her symptoms and the bilateral papilloedema. Evaluation of the cerebral venous system with MRV and or with formal cerebral venography should be included in routine investigations of patients with suspected BIH.

Adult↗
PubMed2003

Water quality characterization and mathematical modeling of dissolved oxygen in the East and West Ponds, Jamaica Bay Wildlife Refuge.

The current study was undertaken to characterize the East and West Ponds and develop a mathematical model of the effects of nutrient and BOD loading on dissolved oxygen (DO) concentrations in these ponds. The model predicted that both ponds will recover adequately given the average expected range of nutrient and BOD loading due to waste from surface runoff and migratory birds. The predicted dissolved oxygen levels in both ponds were greater than 5.0 mg/L, and were supported by DO levels in the field which were typically above 5.0 mg/L during the period of this study. The model predicted a steady-state NBOD concentration of 12.0-14.0 mg/L in the East Pond, compared to an average measured value of 3.73 mg/L in 1994 and an average measured value of 12.51 mg/L in a 1996-97 study. The model predicted that the NBOD concentration in the West Pond would be under 3.0 mg/L compared to the average measured values of 7.50 mg/L in 1997, and 8.51 mg/L in 1994. The model predicted that phosphorus (as PO4(3-)) concentration in the East Pond will approach 4.2 mg/L in 4 months, compared to measured average value of 2.01 mg/L in a 1994 study. The model predicted that phosphorus concentration in the West Pond will approach 1.00 mg/L, compared to a measured average phosphorus (as PO4(3-)) concentration of 1.57 mg/L in a 1994 study.

Animals↗
PubMed2003

Experiments using microarray technology: limitations and standard operating procedures.

Microarrays are a powerful method for the global analysis of gene or protein content and expression, opening up new horizons in molecular and physiological systems. This review focuses on the critical aspects of acquiring meaningful data for analysis following fluorescence-based target hybridisation to arrays. Although microarray technology is adaptable to the analysis of a range of biomolecules (DNA, RNA, protein, carbohydrates and lipids), the scheme presented here is applicable primarily to customised DNA arrays fabricated using long oligomer or cDNA probes. Rather than provide a comprehensive review of microarray technology and analysis techniques, both of which are large and complex areas, the aim of this paper is to provide a restricted overview, highlighting salient features to provide initial guidance in terms of pitfalls in planning and executing array projects. We outline standard operating procedures, which help streamline the analysis of microarray data resulting from a diversity of array formats and biological systems. We hope that this overview will provide practical initial guidance for those embarking on microarray studies.

Animals↗
PubMed2003

Intrathyroidal thyroglossal duct cyst presenting as a thyroid nodule.

A 50-year-old woman presented with a lateral neck swelling, clinically indistinguishable from solitary thyroid nodule. A right hemithyroidectomy was performed and microscopy revealed an intrathyroidal thyroglossal cyst. Intrathyroidal thyroglossal cyst should be considered in the differential diagnosis of a thyroid nodule.

Diagnosis, Differential↗
PubMed2002

Adenocarcinoma of the stomach in Fanconi's anemia.

A case of Fanconi's anemia presenting for the first time at the age of 23 years is described. He died of adenocarcinoma of the stomach 4 months later. As far as the authors are aware, this is the second case of adenocarcinoma of the stomach occurring in Fanconi's anemia. As Fanconi's anemia is known to predispose to malignancy, all patients need detailed evaluation of the gastrointestinal tract by endoscopy as well as radiology for the early detection of gastrointestinal lesions.

Adenocarcinoma↗
PubMed2002

Dimethyl sulfoxide blocks herpes simplex virus-1 productive infection in vitro acting at different stages with positive cooperativity. Application of micro-array analysis.

BACKGROUND: Dimethyl sulfoxide (DMSO) is frequently used at a concentration of up to 95% in the formulation of antiherpetic agents because of its properties as a skin penetration enhancer. Here, we have analyzed the effect of DMSO on several parameters of Herpes Simplex Virus replication. METHODS: Productive infection levels of HSV-1 were determined by plaque assay or by reporter gene activity, and its DNA replication was estimated by PCR. Transcript levels were evaluated with HSV-specific DNA micro-arrays. RESULTS: DMSO blocks productive infection in vitro in different cell types with a 50% inhibitory concentration (IC50) from 0.7 to 2% depending upon the multiplicity of infection. The concentration dependence exhibits a Hill coefficient greater than 1, indicating that DMSO blocks productive infection by acting at multiple different points (mechanisms of action) with positive cooperativity. Consistently, we identified at least three distinct temporal target mechanisms for inhibition of virus growth by DMSO. At late stages of infection, DMSO reduces virion infectivity, and markedly inhibits viral DNA replication. A third mode of action was revealed using an oligonucleotide-based DNA microarray system for HSV. These experiments showed that DMSO reduced the transcript levels of many HSV-1 genes; including several genes coding for proteins involved in forming and assembling the virion. Also, DMSO markedly inhibited some but not all early transcripts indicating a previously unknown mode for inhibiting the early phase of HSV transcription-replication cycle. CONCLUSION: These observations suggest that DMSO itself may have a role in the anti-herpetic activity of formulations utilizing it as a dispersant.

Animals↗
PubMed2002

Optimization of galacto-oligosaccharide production by Bifidobacterium infantis RW-8120 using response surface methodology.

Oligosaccharide (OS) production, cell concentration (2 x 10(9) colony-forming unit/ml), lactose concentration (25% wt/vol), reaction time (6 h), and temperature (50 degrees C) were chosen as the central condition of the central composite design (CCD) for optimizing the production process using Bifidobacterium infantis RW-8120 in skim milk. Statistical analysis (P<0.01) revealed that the most relevant variable concerning OS production and yield was the lactose concentration. The coefficient of determination (R(2)) is good for the second-order OS production model (0.92) and fairly good for the second-order nonlinear OS yield model (0.816). An increase of lactose concentration and temperature resulted in a higher OS production. The optimal values for OS production appear to be near the area associated with the central points of the modeling design except for the lactose concentration, which was 40% (wt/vol) of the final volume.

Bifidobacterium↗
PubMed2002

Endoscopic marsupialization of congenital nasolacrimal duct cyst with dacryocoele.

A congenital nasolacrimal duct cyst is an uncommon condition in the newborn usually treated by ophthalmologists. Prolapse or expansion of the cyst into the nose may lead to respiratory distress and difficulty in feeding as newborns are obligate nose breathers, which needs the involvement of the Otolaryngologist in diagnosis and management. The authors report a series of 8 children presenting with a congenital nasolacrimal duct cyst and dacryocoele and highlight the importance of endoscopic nasal examination of newborns presenting with respiratory problems. Diagnostic studies included intranasal endoscopy and CT scanning of the nasolacrimal system and nose. All the patients were treated by endoscopic marsupialization of the cyst. Nasolacrimal duct abnormality should be considered in the differential diagnosis of neonatal respiratory distress and nasal obstruction. Nasal endoscopy is essential in the work-up of all children with nasal obstruction and respiratory distress. CT scanning is the investigative method of choice. Endoscopic marsupialization followed by lacrimal duct irrigation is effective in the treatment of congenital nasolacrimal duct cyst and results in complete resolution of symptoms.

Cysts↗
PubMed2002

Amiodarone reduces procedures and costs related to atrial fibrillation in a controlled clinical trial.

BACKGROUND: Atrial fibrillation is the most common sustained cardiac arrhythmia, and engenders significant health care costs. The impact of various treatment options for atrial fibrillation on hospital costs has not been evaluated in a randomized trial. METHODS: We analysed 1-year follow-up data on 392 patients randomized to low dose amiodarone (200 mg. day(-1)) or alternative first-line therapy (sotalol or propafenone) in a multicentre trial (Canadian Trial of Atrial Fibrillation, CTAF). RESULTS: Patients in the amiodarone group had fewer electrical cardioversions (65 vs 109 for patients in the sotalol/propafenone group, P<0.0001), and pacemaker insertions (4 vs 11, P=0.07). The average amiodarone patient spent fewer days in hospital (0.47 vs 0.97, P=0.01), and incurred lower costs ($532 vs $898, P=0.03), for admissions where atrial fibrillation was the admitting diagnosis. Average total hospital costs per patient for all admissions, as well as average combined hospital and physician costs per patient, showed wide variations within the treatment arms and were not significantly different between groups. CONCLUSION: For patients in whom antiarrhythmic drug therapy is indicated, low dose amiodarone significantly reduces atrial fibrillation-related costs by reducing the number of atrial fibrillation-related procedures.

Aged↗