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Biomedical subjects

A B Dey

Publications and source records attributed to A B Dey.

At least 19 recordsLinked to original sources

Prevalence and causes of anemia among older adults in India: findings from wave 2 of the Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD).

Anemia among older adults aged&#x2009;&#x2265;&#x2009;60 years is a well-described risk factor that increases the risk of falls, cardiovascular diseases, and mortality. In India, objectively measured national estimates of anemia prevalence and the causes of anemia among older adults are lacking. The Harmonized Diagnostic Assessment of Dementia for the Longitudinal Aging Study in India (LASI-DAD) collected venous blood samples from a nationally representative sample of 3,252 individuals in wave 2 of the study. Out of these, 3,009 samples were used to estimate national prevalence and regional differences in anemia prevalence and its underlying causes. Anemia was defined as hemoglobin&#x2009;<&#x2009;13&#xa0;mg/dl in males and <&#x2009;12&#xa0;mg/dl in females and further categorized into nutritional and non-nutritional anemia based on several nutritional (ferritin, Vitamin B12, and folate), inflammatory (ferritin, C-reactive protein), and renal (serum creatinine) biomarkers. The overall national anemia prevalence was 49.92%. Anemia prevalence was significantly higher among women (53.9%) than men (45.8%). Among those with anemia, nutritional anemia was found in 63.5% of the respondents, with isolated iron deficiency anemia being the most common cause (51.8%). Among the non-nutritional category, anemia of chronic disease was the most common type (31.4%). About 10% of all anemia cases could not be classified into either category using the available data. Regional differences were seen with the highest prevalence of anemia in Assam, West Bengal, Jharkhand, and Odisha, and the lowest prevalence (<&#x2009;30%) in Jammu & Kashmir and Haryana. Multivariate adjustment showed that age, sex, and region of residence are independently associated with anemia status. The study provides valuable insights into the overall anemia prevalence among older adults in India, its underlying causes, and regional differences to lay a strong foundation for making informed decisions toward anemia control in India.

Humans↗

Dichotomy of cytokine profiles in patients and high-risk healthy subjects exposed to tuberculosis.

To better understand the role of cytokines in susceptible and resistant subjects exposed to Mycobacterium tuberculosis infection, intracellular gamma interferon (IFN-gamma) and interleukin-4 (IL-4) in ex vivo peripheral blood-derived CD4(+) T cells were examined by flow cytometry. Of the 37 individuals examined, 20 had clinical evidence of pulmonary tuberculosis and showed acid-fast bacilli in the sputum. Other individuals in close contact with these patients showed no evidence of disease. Patients had a higher number of CD4(+) T cells expressing IFN-gamma and IL-4 in unstimulated cultures compared to healthy subjects. Despite this, the ratio of IFN-gamma(+) to IL-4(+) CD4(+) T cells was similar in both groups. The Th1 response seen in CD4(+) T cells in patients was also observed in the overall pattern of IFN-gamma and IL-4 detected in control culture supernatants by enzyme-linked immunosorbent assay (ELISA). However, after in vitro stimulation of PBMC with heat-killed M. tuberculosis there was a significant reduction in the percentage of IFN-gamma(+) CD4(+) T cells (P < 0.001) in patients. This trend was reflected in the IFN-gamma ELISA assay with supernatants derived from stimulated cultures. However, the accumulated levels of IFN-gamma were higher than those for IL-4. The reduction of IFN-gamma(+) CD4(+) T cells resulted in the dominance of IL-4(+) CD4(+) T cells in 13 patients (P < 0.05). The elevated levels of IL-4(+) CD4(+) T cells seen in patients may contribute to the downregulation of IFN-gamma expression and the crucial effector function of CD4 T cells, leading to the persistence of disease and the immunopathology characteristically seen in patients. Preliminary data on the indicators of apoptosis in antigen-stimulated cultures in PBMC derived from patients are presented. Of the 17 high-risk healthy individuals examined, 11 differed in that, after mycobacterial-antigen stimulation, there was an enhancement in IFN-gamma(+) CD4(+) T cells.

Adult↗

Tuberculosis: a rare cause of splenic abscess.

Splenic abscess is a rare condition associated with septicemic conditions. Splenic abscess due to tuberculosis is still rarer, mostly diagnosed in immuno-compromised hosts. A case of tubercular splenic abscess without any underlying disease is reported.

Abscess↗

Identification of an immunogenic histone-like protein (HLPMt) of Mycobacterium tuberculosis.

We report the identification of the first histone-like protein of Mycobacterium tuberculosis (MTB) (HLPMt). The T cell blot assay was used to identify antigens of MTB associated with human immune response in healthy contacts. Fraction 21 corresponding to proteins in the molecular weight range of approximately 30 kDa were found to be immunogenic in tuberculin reactors. None of the fractions were found to be immunogenic by this assay in non-reactors to tuberculin. All sera, irrespective of the source, showed reactivity with MTB antigen(s) over a wide molecular weight range (205-->16 kDa). In the present study fraction 21 was processed for the generation of murine polyclonal sera and amino acid sequencing. The sequence of a 16-amino acid long peptide showed a 100% homology with an open reading frame (ORF) in the translated sequence of cosmid cY349 (Sanger Centre, Cambridge, UK). The ORF was predicted to code for a protein of 214 amino acids. Oligonucleotide primers were synthesized based on the nucleotide sequence located at the 5' and 3' regions of the gene. The gene encoding the predicted protein was PCR-amplified, cloned, sequenced and expressed in Escherichia coli as a protein of 28 kDa. The expressed HLPMt protein was shown to react with the polyclonal murine sera originally raised against fraction 21. Human immune response to the recombinant HLPMt protein was demonstrated by its ability to induce lymphoproliferation in peripheral blood derived mononuclear cells, and the presence of anti-HLPMt antibodies in pooled patient sera by immunoblot. The recombinant HLPMt protein elicited a vigorous lymphoproliferative response especially in healthy tuberculin reactors compared to non-reactors and patients of tuberculosis, (P < 0.05). The protein has unique dual domains with homology to both bacterial histone-like proteins (HU) and eukaryotic histone H1. Homology to prokaryotic and eukaryotic deoxyribonucleic acid (DNA)-binding proteins suggested that HLPMt could bind DNA. DNA-binding properties were confirmed by South-Western analysis strongly suggesting an interaction between HLPMt and the MTB chromosome.

Amino Acid Sequence↗

The impact of a dedicated "syncope and falls" clinic on pacing practice in northeastern England.

This study examined whether the increased demand for pacemaker implants for carotid sinus syndrome (CSS) at the Regional Pacing Service in northeastern England was related to the establishment of a dedicated "syncope and falls" clinic or to the publication of NASPE and BPEG guidelines for pacing symptomatic bradycardia. To this end, pacemaker rates for various indications at this institution were compared with those of a comparable region (Liverpool), as well as with BPEG's national pacemaker database. Findings indicate a distinct impact of the Newcastle syncope and falls clinic on recognition and pacemaker treatment of CSS.

Accidental Falls↗

Cardiovascular syncope is the most common cause of drop attacks in the elderly.

Drop attacks are defined as a sudden loss of postural tone without loss of consciousness. The mechanism is often unknown. This report examines findings in consecutive elderly patients with drop attacks referred to a dedicated "syncope and falls" center. Thirty-five patients were included. A diagnosis was established in 25 (71%); cardioinhibitory cartoid sinus syndrome (CSS) or mixed CSS in 15, vasodepressor CSS in 3, orthostatic hypotension in 5, vasovagal syncope in 1, and gait imbalance in 1. In 21%, more than one pathological diagnosis was present. In conclusion, absence of a history of syncope is unreliable in elderly patients, and these individuals should be routinely investigated for hemodynamic changes during carotid massage and standing.

Accidental Falls↗

Infections in the elderly.

Ageing of the immune system is a complex process involving both humoral and cell mediated immunity. Along with decline in immunity, morphological changes in various organ makes the elderly especially vulnerable to infection. In clinical practice, infections of respiratory tract and urinary tract, endocarditis, septicaemia and tuberculosis are commonly encountered in elderly subjects Atypical clinical presentation, slow response to treatment and high mortality are hall marks of infection in order patients. Antibiotic therapy in elderly needs to be early, empirical and broad spectrum through parenteral route, with early change over to oral therapy. Aminopenicillins and cephalosporins are safer drugs in old age as compared to aminoglycosides. Pneumococcal and influenza vaccines are recommended in elderly subjects with medical conditions with higher risk of mortality and complications.

Aged↗

Malignant fibrous histiocytoma of the mediastinum.

A case of malignant fibrous histiocytoma of the mediastinum presenting with unusual features of fever and leucocytosis is reported. This is the youngest patient reported in the literature who had this tumour in the mediastinum.

Adolescent↗

Constipation.

Constipation is a common problem in day-to-day practice. As there are wide variations in normal bowel habits, there is no standard definition. Altered colonic transit and disorders of the anorectal mechanism are the essential abnormalities in patients who experience this symptom. While there are several organic causes, functional disorders are by far the commonest cause of constipation. Clinical assessment should include a careful history, eliciting information on lifestyle, diet and personality. Extensive investigations are seldom warranted. Reassurance and long term treatment with a wide range of laxatives provide symptomatic relief.

Constipation↗

Mycoplasma pneumoniae and community-acquired pneumonia.

BACKGROUND: Community-acquired pneumonia is an important cause of mortality and hospitalization in all age groups. In temperate climates, Mycoplasma pneumoniae is a common respiratory pathogen causing pneumonia. Information on human Mycoplasma infection in India is scarce. METHODS: We aimed to determine the frequency of Mycoplasma pneumoniae infection among patients with community-acquired pneumonia in a prospective cross-sectional study. The assessment included clinical and radiological evaluation followed by microbiological evaluation for the specific pathogen. Microbiological investigations included aerobic and anaerobic blood culture, anti-Mycoplasma IgM antibody detection by gelatin particle agglutination test and ELISA, culture of respiratory tract secretions for Mycoplasma pneumoniae and other organisms, and detection of specific Mycoplasma pneumoniae antigen by indirect immunofluorescence. RESULTS: Sixty-two patients (42 men and 20 women; mean age 41.7 years) with community-acquired pneumonia were investigated prospectively. They included 42 immunocompetent and 20 immunocompromised patients. Six patients had definitive evidence of Mycoplasma pneumoniae infection and an additional 16 patients had a probable diagnosis. In all, 22 (35.5%) patients with pneumonia had Mycoplasma pneumoniae infection. Of these, 12 patients belonged to the immunocompromised group and 10 to the immunocompetent group. Patients with Mycoplasma pneumoniae infection also had secondary bacterial infection as evidenced by organisms isolated from blood in 50% and from respiratory tract secretions in 68%. CONCLUSION: Community-acquired pneumonia has a polymicrobial aetiology, of which the prevalence of Mycoplasma pneumoniae is 35%. The study has two implications: (i) Mycoplasma pneumoniae infection is frequently associated with secondary bacterial infection; and (ii) initial empirical antibiotic therapy for community-acquired pneumonia in India must include antibiotics with activity against Mycoplasma pneumoniae.

Adolescent↗

The use of diagnostic bronchoscopy in lung cancer.

BACKGROUND: The role of fibreoptic bronchoscopy in the diagnosis of bronchogenic carcinoma is well established. However, in developing countries, where the burden of illness is large and diagnostic facilities are limited, only a small number of patients are diagnosed at a stage when they might benefit from operation. We felt it would be desirable to identify subsets of patients suspected of harbouring lung cancers, in whom bronchoscopy would have not only a high diagnostic yield but also provide useful information which might influence treatment, the patient's quality of life and duration of survival. METHOD: We analysed the records of 588 patients, who had been bronchoscoped for suspected lung cancer, over a period of 8 years at a tertiary referral centre in north India. The patients were divided into different clinical subgroups on the basis of their clinical and radiological presentation, and the diagnostic yield from bronchoscopy in each group was calculated. A decision analysis model was constructed and the expected value of clinical information was determined for each group. RESULTS: A tissue diagnosis was established by bronchoscopy in 177 (30%) patients and by additional investigations in 43 (7.3%) patients. A positive tissue diagnosis was obtained most often in patients with clinical and radiological evidence of pulmonary collapse (50%) and mass lesions (38-42%). Only 12% of patients with malignancy underwent resection and 70% of them belonged to the above two groups. The expected value of clinical information was greatest in patients with collapse (0.077) or mass lesions (0.067-0.065). CONCLUSIONS: A diagnostic work-up including fibreoptic bronchoscopy is indicated early in patients with collapse or mass lesions of the lung. Patients with non-resolving pneumonia, pleural effusion, metastatic disease and non-specific lesions on chest X-ray should receive a low priority for bronchoscopy.

Adolescent↗

Bronchial adenoma--an eleven-year experience.

Thirteen patients with bronchial adenoma were investigated. Most of these were young males and had recurrent hemoptysis and chest infection. Radiographs of the chest were abnormal in 11 patients. The tumor was visualized by fiberoptic bronchoscopy in all but one patient. The procedure was safe and none of the patients had massive hemoptysis following bronchoscopic biopsy. Limited follow-up revealed good results following surgery.

Adult↗

Fiberoptic bronchoscopy in patients with haemoptysis and normal chest roentgenograms.

Over the last 10 years, 53 patients with hemoptysis, but with a normal chest radiograph underwent diagnostic fiberoptic bronchoscopy. Forty-three patients did not show any abnormal findings, the site of bleeding could be localised in five and non-specific mucosal changes were seen in the remaining five patients. Thirty-two patients were followed up clinically for a 3-18 months period. One patient on follow-up developed tubercular pleural effusion. Bronchogenic carcinoma was not detected in any of these patients during the procedure or at follow up. A review of literature revealed a 3 per cent incidence of bronchogenic carcinoma and the risk factors associated with higher incidence were age above 40 years, cigarette smoking and a longer duration of hemoptysis. We conclude that fiberoptic bronchoscopy has little role in this relatively benign condition (hemoptysis) especially when the risk factors are absent.

Adult↗