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Biomedical subjects

A Mohan

Publications and source records attributed to A Mohan.

At least 19 recordsLinked to original sources

Stem cell markers: ABCG2 and MCM2 expression in retinoblastoma.

BACKGROUND/AIM: The authors studied the expression of cancer stem cell surface marker, ABCG2, and neural stem cell marker, MCM2, in retinoblastoma and correlated clinicopathologically. METHODS: Among 39 retinoblastomas, 18 tumours were not subjected to preoperative/postoperative chemotherapy, 15 tumours underwent postoperative chemotherapy, and six tumours had preoperative chemotherapy. There were 20 tumours with no invasion and 19 tumours with invasion of choroid/optic nerve. ABCG2 and MCM2 expression was studied by immunohistochemistry. RESULTS: ABCG2 was positive in six of six and MCM2 was positive in five of six tumours that had recurred in the orbit or metastasised. ABCG2 was positive in 15/19 tumours with invasion. MCM2 was positive in 16/19 tumours with invasion. Invasive tumours showed higher expression of ABCG2 (p < 0.01) and MCM2 (p < 0.01) proteins. There was no correlation with differentiation and laterality of the tumours. Non-neoplastic retina was positive for ABCG2 and MCM2. CONCLUSION: ABCG2 and MCM2 were expressed more in invasive tumours. Further studies are needed to understand the significance of ABCG2 and MCM2 expression in retinoblastoma.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

Quality of life in newly diagnosed patients with lung cancer in a developing country: is it important?

There are no data regarding quality of life (QoL) assessments in lung cancer in developing countries like India. Quality of life was evaluated in 76 newly diagnosed lung cancer patients by using the World Health Organization Quality of Life questionnaire in Hindi (WHOQoL-Bref) (men 87%). The mean age was 55 years (SD = 10). Cough, dyspnoea, chest pain and haemoptysis were present in 83%, 72%, 66% and 43% of patients respectively. The median duration of symptoms was 5.9 months (range 1-13). Eighty-nine per cent had non-small cell lung cancer. The median pack-years smoked was 23 (range 0.5-88). Most patients (53%) had a Karnofsky's Performance Status (KPS) of 70 and 83% had stage III or IV disease. Quality of life did not correlate with age, gender, presence or duration of symptoms, histological type, stage of disease or degree of smoking. The physical and psychological domains of QoL correlated significantly with the KPS (P = 0.001 and P = 0.01 respectively). Patients with a KPS of 80 had better physical (P < 0.001), psychological (P < 0.01) and social (P < 0.05) QoL than those with a KPS of 70. In conclusion, patients with lung cancer in a developing country like India have an unsatisfactory QoL. The Karnofsky's Performance Scale is a simple and reliable surrogate marker for assessing QoL in these patients. Larger multi-centric studies may help in providing a more comprehensive evaluation of the effect of various demographic and clinical variables on QoL in this setting.

Carcinoma, Non-Small-Cell Lung↗

Predictors of development and outcome in patients with acute respiratory distress syndrome due to tuberculosis.

OBJECTIVE: To study the predictors of development and determinants of outcome in patients with acute respiratory distress syndrome (ARDS) due to tuberculosis (TB). METHODS: Retrospective case-control study of demographic, clinical and laboratory data of hospitalised adult patients with active TB. RESULTS: Of 2733 TB patients treated during 1980-2003, 29 (1.06%; 1.21 patients/year; mean age 31.6 +/- 10.9 years; 16 males) developed ARDS (cases). Seven had pulmonary TB and 22 had miliary TB (MTB); 298 (mean age 32.0 +/- 14.2 years; 110 males) who did not develop ARDS constituted controls. Presence of MTB (OR 4.6, 95%CI 1.2-17.8; P = 0.02), duration of illness beyond 30 days at presentation (OR 177.9, 95%CI 39-811.7; P < 0.001), absolute lymphocyte count < 1625/ mm3 (OR 4.5, 95%CI 1.1-19.3; P = 0.04) and serum ALT > 100 IU (OR 15.7, 95%CI 3.0-81.1, P < 0.001) were independent predictors of ARDS development. Twelve cases died (41.4%). Patients with APACHE II score >18; those with APACHE II score <18 in the presence of hyponatraemia and PaO2/FIO2 ratio <108.5 were likely to die. CONCLUSIONS: In patients with TB, prolonged illness, MTB, absolute lymphocytopaenia and elevated ALT are independently associated with ARDS development. APACHE II score, serum sodium and PaO2/FIO2 ratio are determinants of outcome.

Adult↗

A stepped approach for prediction of obstructive sleep apnea in overtly asymptomatic obese subjects: a hospital based study.

BACKGROUND AND PURPOSE: Prevalence of obstructive sleep apnea (OSA) is high in obese subjects, many of whom may not be overtly symptomatic. Polysomnography (PSG) is a costly and time-consuming investigation. Since it is not feasible to subject all obese individuals to PSG, it is useful to define predictors of OSA among these subjects. PATIENTS AND METHODS: One hundred and eighteen obese subjects [body mass index (BMI)> or =25 kg/m(2)] presenting to the hospital with non-sleep related complaints were included, of which 53 subjects with PSG evidence of OSA [apnea-hypopnea index (AHI)> or =15/h] were defined as cases and 65 subjects without any evidence of OSA (AHI<15/h) were defined as controls. Anthropometry, biochemical investigations, blood gas analysis, pulmonary function tests, and PSG were performed for all subjects. RESULTS: Waist hip ratio (WHR) (as percentage of a standard) [odds ratio (95% CI): 1.07 (1.00-1.14); P = 0.049] male gender [odds ratio (95% CI): 3.97 (0.99-15.81); P = 0.046] and neck circumference (NC) [odds ratio (95% CI): 1.23 (1.03-1.47); P = 0.023] were found to be independent predictors of OSA. Overnight oxygen desaturation data were evaluated in patients selected as having OSA on the basis of these clinical markers, and the best cut-off for level of desaturation (10%) was defined. The stepped approach had a specificity, sensitivity, positive and negative predictive value of 89.2, 88.5, 86.8 and 90.6%, respectively, for the diagnosis of OSA. CONCLUSIONS: Male gender, WHR and NC are independent predictors of OSA in overtly asymptomatic obese subjects. A stepped approach to diagnose OSA should be used, as it is accurate and cost-effective.

Adult↗

Extrapulmonary tuberculosis.

Extrapulmonary involvement can occur in isolation or along with a pulmonary focus as in the case of patients with disseminated tuberculosis (TB). The recent human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS) pandemic has resulted in changing epidemiology and has once again brought extrapulmonary tuberculosis (EPTB) into focus. EPTB constitutes about 15 to 20 per cent of all cases of tuberculosis in immunocompetent patients and accounts for more than 50 per cent of the cases in HIV-positive individuals. Lymph nodes are the most common site of involvement followed by pleural effusion and virtually every site of the body can be affected. Since the clinical presentation of EPTB is atypical, tissue samples for the confirmation of diagnostic can sometimes be difficult to procure, and the conventional diagnostic methods have a poor yield, the diagnosis is often delayed. Availability of computerised tomographic scan, magnetic resonance imaging laparoscopy, endoscopy have tremendously helped in anatomical localisation of EPTB. The disease usually responds to standard antituberculosis drug treatment. Biopsy and/or surgery is required to procure tissue samples for diagnosis and for managing complications. Further research is required for evolving the most suitable treatment regimens, optimal duration of treatment and safety when used with highly active antiretroviral treatment (HAART).

Adrenal Cortex Hormones↗

Multidrug-resistant tuberculosis.

Multidrug-resistant tuberculosis (MDR-TB) caused by Mycobacterium tuberculosis resistant to both isoniazid and rifampicin with or without resistance to other drugs is among the most worrisome elements of the pandemic of antibiotic resistance. Globally, about three per cent of all newly diagnosed patients have MDR-TB. The proportion is higher in patients who have previously received antituberculosis treatment reflecting the failure of programmes designed to ensure complete cure of patients with tuberculosis. While host genetic factors may probably contribute, incomplete and inadequate treatment is the most important factor leading to the development of MDR-TB. The definitive diagnosis of MDR-TB is difficult in resource poor low income countries because of non-availability of reliable laboratory facilities. Efficiently run tuberculosis control programmes based on directly observed treatment, short-course (DOTS) policy is essential for preventing the emergence of MDR-TB. Management of MDR-TB is a challenge which should be undertaken by experienced clinicians at centres equipped with reliable laboratory service for mycobacterial culture and in vitro sensitivity testing as it requires prolonged use of expensive second-line drugs with a significant potential for toxicity. Judicious use of drugs, supervised individualised treatment, focussed clinical, radiological and bacteriological follow up, use of surgery at the appropriate juncture are key factors in the successful management of these patients. In certain areas, currently available programme approach may not be adequate and innovative approaches such as DOTS-plus may have to be employed to effectively control MDR-TB.

Causality↗

Uncommon manifestations of sarcoidosis.

OBJECTIVE: To study the uncommon manifestations in patients of sarcoidosis. METHODS: This is a prospective study of uncommon manifestations observed in 93 of the 210 biopsy proved patients (mean age 43.8 +/- 6.4 years; 58 males) of sarcoidosis seen by us over the last 22 years at the All India Institute of Medical Sciences, New Delhi. RESULTS: Clinical presentation of acute sarcoidosis in the form of Löfgren's syndrome (n = 5) was uncommonly observed. Rare pulmonary manifestations included seasonal dyspnoea with audible wheezing mimicking bronchial asthma (n = 30); narrowing of main bronchi, fixed upper airways obstruction (n = 1); pleural involvement (n = 7); bullous lung disease (n = 2); chronic respiratory failure (n = 2); and vocal cord involvement (n = 4). Other notable features were glaucoma (n = 4); digital clubbing (n = 3); sarcoid nephritis (n = 1); and sicca syndrome (n = 1). Uncommon neurological manifestations included bilateral sequential facial nerve palsy (n = 2); optic atrophy (n = 2); optic neuritis, proximal myopathy, multiple brainstem lesions, pituitary stalk lesion (one patient each). Cardiac involvement occurred in 15 patients. This included complete heart block (n = 2); congestive heart failure (n = 4); supraventricular ectopics (n = 6); ventricular ectopics (n = 2); and recurrent ventricular tachycardia requiring radiofrequency ablation (n = 1). Contrast-enhanced computerised tomographic scan (CECT scan) of the abdomen revealed intrabdominal lymphadenopathy (n = 5); infiltrates in the liver and spleen (n = 3). Portal hypertension was observed in four patients with grade IV (n = 2) and grade II oesophageal varices (n = 2). One of the patients with grade IV oesophageal varices had recurrent haematemesis and successfully underwent endoscopic sclerotherapy while another patient with grade IV varices succumbed to massive haematemesis. CECT scan was found to be useful in localising the lesions in patients with extrapulmonary sarcoidosis. CONCLUSION: Awareness regarding uncommon manifestations of sarcoidosis will facilitate early confirmation of diagnosis.

Adult↗

Laser bronchoscopy--current status.

The majority of patients with lung cancer have advanced disease with severe endobronchial symptoms such as cough, dyspnea, and hemoptysis for which palliation is required. Laser resection of endobronchial lesions located in the trachea, mainstem or proximal lower lobe bronchi provides significant and rapid improvement in the patient's symptoms. Neodymium:yttrium-aluminium-garnet (Nd:YAG) laser is gaining popularity due to efficient photocoagulation, good penetration and excellent hemostasis. Complications are rare and can be minimized by following standardized techniques and safety guidelines. Laser resection is equally effective with the rigid and flexible bronchoscope. The future may see combinations of laser with other palliative modalities to improve the chances of a symptom-free life for lung cancer patients.

Bronchoscopes↗

Scientific basis of directly observed treatment, short-course (DOTS).

The introduction of rifampicin, pyrazinamide and ethambutol ushered in the era of "short course chemotherapy". Multidrug resistance TB (MDR-TB) is threatening to destabilise the best efforts of TB control. Treatment of MDR-TB is difficult, expensive and toxic and is often unsuccessful. DOTS is an interventional strategy designed to effectively diagnose and treat TB. The fundamental principles in the DOTS strategy are: Polititical will, diagnosis by sputum microscopy, directly observed standardised short-course treatment, adequate supply of good quality drugs, systematic monitoring and accountability. Patients with HIV infection and TB disease respond well to antituberculosis treatment if they are given short-course chemotherapy in the programme of DOTS.

Antitubercular Agents↗

Does routine home visiting improve the return rate and outcome of DOTS patients who delay treatment?

Over a period of 6 months the effect of home visits on compliance with directly observed therapy, short course (DOTS), was studied on 480 new smear-positive tuberculosis patients who had delayed collecting their drugs on one occasion. Patients registered at 15 tuberculosis treatment centres in Baghdad, Iraq, were randomized to an intervention group (receiving home visits from trained personnel) or a control group. Home visits were highly effective in improving the return to treatment of patients who were late for treatment (231/240, 96.3%). The intervention group showed a higher treatment success rate (94.2% versus 76.7%), lower default rate (0.8% versus 10.0%) and higher smear conversion rate after the end of treatment (92.9% versus 75.0%) than controls. Home visiting by trained personnel significantly improves patient compliance with DOTS.

Antitubercular Agents↗

Sarcoidosis: global scenario & Indian perspective.

Sarcoidosis is now recognised as a member of a large family of granulomatous disorders and has been reported from all parts of the world. Current evidence points to genetic predisposition and exposure to yet unknown transmissible agent(s) and/or environmental factors as etiological agents. Depending on the organ systems involved, patients with sarcoidosis present themselves to various specialities; pulmonary involvement is by far the commonest and occurs in about 90 per cent of the patients. The diagnosis is based on a compatible clinical and/or radiological picture, histopathological evidence of non-caseating granulomas in tissue biopsy specimens and exclusion of other diseases capable of producing similar clinical or histopathological appearances. Sarcoidosis is an underdiagnosed disease in India. However, owing to the increasing awareness, it is being diagnosed more frequently than a few decades ago. Most Indian patients with sarcoidosis are males and present in the fourth or fifth decade of life. The disease runs a benign course with spontaneous remission of the activity though some degree of residual pulmonary function abnormality persists. Only a minority of the patients develop complicated disease. Corticosteroids remain the mainstay of treatment. For asymptomatic patients with pulmonary sarcoidosis, no therapy is required. Corticosteroid treatment should be considered in symptomatic patients with evidence of radiological or pulmonary function deterioration. Treatment under close clinical monitoring should be tailored to suit the needs of the individual patient. Sometimes steroid-sparing alternative treatments may be beneficial. In this review, the current understanding of the global scenario and Indian perspective of sarcoidosis are critically reviewed.

Adrenal Cortex Hormones↗

A synthetic, structural, magnetic, and spectral study of several [Fe[tris(pyrazolyl)methane]2](BF4)2 complexes: observation of an unusual spin-state crossover.

The complexes [Fe[HC(3,5-Me2pz)3]2](BF4)2 (1), [Fe[HC(pz)3]2](BF4)2 (2), and [Fe[PhC(pz)2(py)]2](BF4)2 (3) (pz = 1-pyrazolyl ring, py = pyridyl ring) have been synthesized by the reaction of the appropriate ligand with Fe(BF4)2.6H2O. Complex 1 is high-spin in the solid state and in solution at 298 K. In the solid phase, it undergoes a decrease in magnetic moment at lower temperatures, changing at ca. 206 K to a mixture of high-spin and low-spin forms, a spin-state mixture that does not change upon subsequent cooling to 5 K. Crystallographically, there is only one iron(II) site in the ambient-temperature solid-state structure, a structure that clearly shows the complex is high-spin. Mössbauer spectral studies show conclusively that the magnetic moment change observed at lower temperatures arises from the complex changing from a high-spin state at higher temperatures to a 50:50 mixture of high-spin and low-spin states at lower temperatures. Complexes 2 and 3 are low-spin in the solid phase at room temperature. Complex 2 in the solid phase gradually changes over to the high-spin state upon heating above 295 K and is completely high-spin at ca. 470 K. In solution, variable-temperature 1H NMR spectra of 2 show both high-spin and low-spin forms are present, with the percentage of the paramagnetic form increasing as the temperature increases. Complex 3 is low-spin at all temperatures studied in both the solid phase and solution. An X-ray absorption spectral study has been undertaken to investigate the electronic spin states of [Fe[HC(3,5-Me2pz)3]2](BF4)2 and [Fe[HC(pz)3]2](BF4)2. Crystallographic information: 2 is monoclinic, P2(1)/n, a = 10.1891(2) A, b = 7.6223(2) A, c = 17.2411(4) A, beta = 100.7733(12) degrees, Z = 2; 3 is triclinic, P1, a = 12.4769(2) A, b = 12.7449(2) A, c = 13.0215(2) A, alpha = 83.0105(8) degrees, beta = 84.5554(7) degrees, gamma = 62.5797(2) degrees, Z = 2.

Crystallography↗

Ehlers-Danlos syndrome with bladder diverticula.

We describe an Indian man with the unusual association of classical cutaneous features of Ehlers-Danlos syndrome, a marfanoid habitus, bladder diverticula and multiple emphysematous bullae.

Diverticulum↗