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Biomedical subjects

A Mohan

Publications and source records attributed to A Mohan.

At least 91 records · Page 5Linked to original sources

Video assisted thoracoscopic surgery (VATS) in the diagnosis of intrathoracic pathology: initial experience.

We report our experience with the use of video-assisted thoracoscopic surgery [VATS] in the diagnosis of intrathoracic disease of unknown origin. In the last two years, 32 patients (18 males) underwent this procedure for diagnostic purposes. Of them, 18 patients had lung pathology, eight mediastinal and six pleural disease. All attempts at achieving a tissue diagnosis were unrewarding. In all of them, diagnostic thoracotomy was being contemplated to procure tissue for histopathological diagnosis. Diagnostic thoracoscopy was successful in providing tissue diagnosis in all the patients with lung disease; seven of the eight patients with mediastinal pathology and five of the six patients with pleural lesions. Diagnostic thoracoscopy was associated with minimal morbidity, short hospital stay, better cosmetic result and quicker return to work as compared to conventional thoracotomy. We conclude that video-assisted thoracoscopy is an excellent diagnostic tool to confirm tissue diagnosis in patients with undiagnosed chest diseases.

Adolescent↗

Adrenocortical reserve and morphology in tuberculosis.

Ninety seven patients (63 males, mean age 31.8 years, SD 2.3) with various forms of tuberculosis were studied. All of them were HIV negative. Thirty normal control subjects (16 males, mean age 36.4 years, SD 1.8) were also studied. Fifty-eight of the 97 patients (59.8%) were malnourished (BMI < 18 kg/m2). The mean basal serum cortisol was lower in the TB group (n = 91) (351 nmol/1; SD 150) as compared to the normal control group (n = 8) (402 nmol/1; SD 93) but this difference did not attain statistical significance. Following administration of synthetic ACTH (cosyntropin), the 30 and 60 minutes mean serum cortisol values in the TB group were significantly lower as compared to the normal control group (p < 0.05). Forty five of the 91 patients (49.5%) who underwent the ACTH stimulation test had compromised adrenal reserve. Fourteen of the 86 patients (16.3%) in whom adrenal morphology was studied revealed adrenal gland enlargement on abdominal CT scan. ACTH stimulation was done in 12 of these 14 patients and eight of them had compromised adrenal reserve. Repeat ACTH stimulation done six months to one year after treatment in 13 patients revealed significantly increased 30 minutes (p < 0.05) and 60 minutes (p < 0.05) serum cortisol values. While nine of these 13 patients were negative responders before treatment, only three of them had evidence of compromised adrenal reserve after one year of antituberculosis treatment, (p < 0.05). Serum cortisol values in patients with drug-sensitive and drug-resistant tuberculosis did not differ significantly. Patients with drug-resistant tuberculosis had a higher prevalence of adrenal gland enlargement (7 of the 30) as compared to those with drug-sensitive tuberculosis (7 of the 56) (p = NS). Subclinical adrenal insufficiency is prevalent in a significant number of patients with both drug-sensitive and drug-resistant tuberculosis, and in some of these it is associated with adrenal gland enlargement. The compromised adrenal reserve and enlargement seem to reverse with therapy.

Adrenal Cortex Hormones↗

Association between isolated hypercholesterolemia, isolated hypertriglyceridemia and coronary artery disease in south Indian type 2 diabetic patients.

Very high prevalence rates of coronary artery disease have been reported among Indians. The aim of this study was to determine the relative importance of isolated hypercholesterolemia, isolated hypertriglyceridemia, isolated high low-density lipoprotein and isolated low high-density lipoprotein in coronary artery disease among South Indian type 2 diabetic subjects. The study group comprised of 17,885 type 2 diabetic patients attending our institute. A history of documented myocardial infarction was considered as the diagnostic criteria for coronary artery disease. Isolated hypercholesterolemia was defined as serum cholesterol over 200 mg/dL with normal serum triglyceride levels (< or = 200 mg/dL); isolated hypertriglyceridemia was defined as serum triglyceride level over 200 mg/dL with normal serum cholesterol levels (< or = 200 mg/dL). Isolated low high-density lipoprotein was defined as one below 35 mg/dL with normal serum triglyceride levels. Isolated high low-density lipoprotein cholesterol was defined as one over 150 mg/dL with normal serum triglyceride levels. Normolipidemia was defined as serum cholesterol and serum triglyceride both upto 200 mg/dL, high-density lipoprotein 35 mg/dL or above and low-density lipoprotein upto 150 mg/dL. The prevalence of coronary artery disease was significantly high among patients with isolated hypercholesterolemia (4.1%; p < 0.001), isolated high low-density lipoprotein (4.5%; p < 0.001) and isolated low high-density lipoprotein (3.9%; p = 0.005) compared to normolipidemic individuals (2.8%), but not in those with isolated hypertriglyceridemia (3.4%). The odds ratios for coronary artery disease increased with each quartiles of isolated cholesterol, isolated low-density lipoprotein cholesterol and total cholesterol to high-density lipoprotein ratio and reached statistical significance in the last quartile (p < 0.05). There was no significant increase in the odds ratios for coronary artery disease in relation to quartiles of isolated triglycerides. For isolated low high-density lipoprotein, when the last quartile was taken as the reference, the odds ratio for coronary artery disease in the first quartile reached statistical significance (p = 0.03). Multivariate regression analysis revealed age (odds ratio 1.06; p < 0.001), male sex (odds ratio 1.7; p < 0.001), hypercholesterolemia (odds ratio 1.26; p = 0.07) and high low-density lipoprotein levels (odds ratio 1.22; p = 0.043) to be strongly associated with coronary artery disease. Among South Indian type 2 diabetic subjects, serum isolated hypercholesterolemia and high low-density lipoprotein cholesterol but not isolated hypertriglyceridemia appear to be associated with coronary artery disease.

Adult↗

A prospective study of sensitivity and specificity of adenosine deaminase estimation in the diagnosis of tuberculosis pleural effusion.

We prospectively evaluated the usefulness of adenosine deaminase [ADA] estimation in the diagnosis of tuberculosis [TB] pleural effusion. Seventy five subjects with pleural effusion were studied. Forty eight of them had TB pleural effusion [M:F: 37:11; mean age 33 +/- 14.4 years range 17-76] and the remaining 27 had pleural effusion due to causes other than TB [non-TB group] [M:F: 19:8; mean age 47.3 +/- 16.5 years; range 17-75]. Pleural fluid [PF] ADA levels were significantly higher in TB (n=48; mean 95.8 +/- 57.5 IU/L) compared with non-TB group (n=27; mean 30.7 +/- 27.2 IU/L) [p<0.001]. Serum ADA [S-ADA] levels were also significantly higher in TB (n=45; mean 39.6 +/- 18.3 IU/L) compared with non-TB group (n=26; mean 18.0 +/- 13.7 IU/L) [p<0.001]. PF-ADA levels were higher compared to S-SDA in TB (p <0.001) and non-TB groups [p<0.01]. Using a cut off of 35 IU/L, the sensitivity and specificity of PF-ADA in the diagnosis of TB was computed to be 83.3% and 66.6% respectively. At a cut-off level of 100 IU/L, PF-ADA was found to have a sensitivity 40% and specificity 100%. From this study it is concluded that, using 100 IU/L as the cut-off, it is possible to avoid pleural biopsy to ascertain the diagnosis of TB in as much as 40% of the patients.

Adenosine Deaminase↗

Recognition of cyclooxygenase-2 (COX-2) active site by NSAIDs: a computer modelling study.

The energetics and models of COX-2 complexed with nonsteroidal anti-inflammatory drugs (NSAIDs) having different degrees of selectivity for two isoforms of COX (COX-2 and COX-1) have been studied using computer modelling approach. The models are obtained for complexes of NS398 (NS), a selective COX-2 inhibitor; indoprofen (Ind), a non-selective inhibitor; di-tert-butylbenzofurans (DHDMBFs) with substituents at the 5th position: CONH(CH2)2OMe (BF1), CONH-c-Pr (BF2), 3-methylene-gamma-butyrolactonyl (BF3) and oxicams namely, meloxicam (Mel), piroxicam (Pir) and tenoxicam (Ten). These were optimized using molecular mechanics (MM) and molecular dynamics (MD) techniques. The binding energies and structures were compared with pharmacological parameters and available results with COX-1. In case of NS a larger difference in the binding energies between COX-2 and COX-1 was noticed as compared to that of Ind. It also had stronger interaction with His90 and Tyr355 which is considered important for COX-2 selectivity. There was a difference in the compactness at the channel entrance between COX-2 selective and non-selective ligands. Models with DHDMBFs and oxicams showed a similar correlation. The results were used to design a peptide inhibitor, Tyr-Arg-Cys-Ala-delta Phe-Cys (Pept) which could fit better in the COX-2 cavity. As per our MD simulation results this peptide inhibitor showed both higher activity and COX-2 selectivity.

Anti-Inflammatory Agents, Non-Steroidal↗

Sleep disordered breathing in chronic obstructive pulmonary disease.

We prospectively studied sleep disordered breathing in 50 consecutive patients (39 males) with chronic obstructive pulmonary disease (COPD) with chronic respiratory failure (CRF) (n=33) and without CRF (n=17) by performing polysomnography. Patients with CRF had a lower mean nocturnal oxygen saturation (SaO2 %) (88.6+/-6.7 vs. 96.3+/-0.8; p=0.0001) and a lower minimal nocturnal SaO2 (73.6+/-12.0 vs. 84.3+/-7.3; p=0.002) compared to those without CRF, suggesting that patients with CRF tend to have more severe drops in nocturnal SaO2. Patients with CRF also had a lower FEV1 (% predicted) (p=0.01) and PEFR (% predicted) (p=0.031) compared to those without CRF suggesting an indirect relation to the oxygen saturation. Other pulmonary functions were comparable between both the groups. Among patients with and without CRF, the total sleep time (minutes); the rapid eye movement (REM) stage (% of total sleep time); the non-rapid eye movement (NREM) stage (% of total sleep time) were comparable (p=NS). Only three of the 50 patients with COPD had a significant (>5) apnea-hypopnea index (AHI) (total no. of apneas + total no. of hypopneas/ total sleep time [(hours) = AHI] and these three patients had a mean BMI = 27.7 which was higher than the mean BMI of the whole group (21.1). The AHI was comparable in patients with and without respiratory failure. Multiple regression analysis revealed a positive correlation between AHI and the neck circumference (r=0.41; p=0.005) and BMI (r=0.31; p=NS). There was a small but statistically insignificant negative correlation between AHI and neck length (r= -0.28; p=NS). We conclude that, BMI per se contributes to the AHI and nocturnal desaturation in patients with COPD.

Adult↗

Abdominal tuberculosis: diagnosis by laparoscopy and colonoscopy.

BACKGROUND: Histopathological confirmation in abdominal tuberculosis is difficult due to suboptimal noninvasive access to the involved area. Peritoneoscopy and colonoscopy provide semi-invasive access to the peritoneum, large intestine and ileocecal area. Information on the diagnostic yield of these two investigation in abdominal tuberculosis is scarce. OBJECTIVE: To evaluate the role of laparoscopy and colonoscopy in the diagnosis of abdominal tuberculosis. PATIENTS AND METHODS: Between January 1998 and July 2001, 34 patients were diagnosed to have abdominal tuberculosis on the basis of laparoscopy or colonoscopy. The case records of these patients were retrospectively reviewed to assess the usefulness of laparoscopy and colonoscopy in the diagnosis of abdominal tuberculosis. RESULTS: Laparoscopy was performed in 23 patients. Peritoneal tuberculosis was diagnosed in 19 of them, characterized by presence of ascites, multiple whitish tubercles, fibrous bands and adhesions, hyperaemic edematous bowel loops or dense adhesions without ascites. Multiple jejunoileal hyperemic short segments with serosal neovascularization was noticed in three patients. One patient had cecal mass with pericecal inflammatory adhesions. In three patients, laparoscopy was converted to open laparotomy due to bowel injury, extensive adhesions, and difficulty in assessing lymph nodal mass in one patient each. Peritoneal biopsy confirmed the diagnosis in 10 of the 15 (67%) patients. In one patient pericecal tissue biopsy confirmed the diagnosis. The remaining patients received therapeutic trial with anti tuberculosis treatment. All patients showed good response. Thus laparoscopy provided positive diagnosis of tuberculosis in 20/23 (87%) and positive histology in 10 of the 15 (67%) patients with peritoneal lesions. Thirteen patients underwent colonoscopy. Mucosal lesions involving terminal ileum, cecum and colon was noted in 11 patients. Colonoscopic biopsy confirmed the diagnosis in six of the 11 patients (54%). Non of these patients had any complication related to colonoscopy. CONCLUSION: Laparoscopy was safe and helped in the diagnosis of peritoneal as well as intestinal tuberculosis in 87% of patients. Colonoscopy is useful for colonic and terminal ileal lesion with a positive diagnostic yield of 54%.

Adolescent↗

Eosinophilic pleural effusion and presence of filariform larva of Strongyloides stercoralis in a patient with metastatic squamous cell carcinoma deposits in the pleura.

A 58-year-old, human immunodeficiency virus (HIV) negative, male farmer presented with a right-sided hemorrhagic, exudative, eosinophilic, rapidly reaccumulating pleural effusion. Pleural biopsy revealed secondary deposits from a squamous cell carcinoma. Wet mount film of pleural fluid unexpectedly showed filariform larvae of Strongyloides stercoralis. Our observation suggests that strongyloidiasis should be considered as the etiological cause for pleural effusion of obscure etiology. The threshold for suspicion should be high if the pleural effusion is exudative and eosinophil rich.

Animals↗

Non small cell lung cancer (NSCLC): current status and future prospects.

The incidence of lung cancer is rising dramatically and it is now the commonest cause of mortality and morbidity not only in the industrialised countries, but in developing nations like India as well. Tobacco smoking has consistently been demonstrated to be an important aetiological factor, though lung cancer occurs in non-smokers also. In spite of great advances in radiological and molecular diagnostic techniques, the ideal screening marker for early detection of lung cancer has still not been found. Histological diagnosis and staging is essential for selecting the mode of therapy in patients with lung cancer. Stages I and II are amenable to surgery. However, advanced stage III and IV need an individualised combination of surgery, chemotherapy and radiotherapy. With a better understanding of the cellular mechanisms operating in carcinogenesis, newer target specific modalities are being developed and tested in order to stem this disease, which threatens to assume epidemic proportions.

Carcinoma, Non-Small-Cell Lung↗

Unilateral pulmonary agenesis: an uncommon cause of lower zone lung opacity.

Congenital abnormalities of the lung are rare and are often misdiagnosed. We report the case of a young girl who was initially diagnosed to have pleural effusion with collapse. After detailed evaluation including computerised tomographic (CT) scan and fiberoptic bronchoscopy, a final diagnosis of unilateral pulmonary agenesis was made. This condition must be suspected in differential diagnosis in a young person presenting with features of lung collapse.

Adolescent↗

Clinical and echocardiographic findings in patients with myocardial toxicity due to scorpion sting.

BACKGROUND: Myocardial toxicity following a sting by the Indian red scorpion (Mesobuthus tamulus) is a life-threatening medical emergency. A perusal of the published literature suggests that this problem has seldom been studied systematically. METHODS: We retrospectively studied the clinical presentation and echocardiographic findings in 24 patients (mean [SD] age 23.2 [11.7] years; 19 males) with myocardial toxicity caused by the sting of an Indian red scorpion (Mesobuthus tamulus). They were treated with inotropic support and diuretics depending on the requirement. At admission, oral L-carnitine was administered in a dose of 1980 mg/day in three divided doses till the left ventricular (LV) function normalized. None of the patients received digitalis, prazosin, hydrocortisone or antivenin. RESULTS: Extreme anxiety and severe pain at the site of sting were present in all the patients. Hypotension (n = 19), pulmonary oedema (n= 15) and acute renal failure (n=8) were the other presenting features. Chest X-ray revealed cardiomegaly in 8 and pulmonary oedema in 13 patients. Serum creatinine phosphokinase levels were elevated more than two times the upper limit of normal (200 IU/L) in 22 patients (92%). The mean duration of hospitalization was 5 days (range 3- 11 days). L-carnitine treatment resulted in significant reduction in the LV diameter (mm) in diastole (47.6 [6.2] v. 42 [6.1], p < 0.01) and systole (42 [7.1] v. 28.2 [4], p<0.001); end-diastolic volume (ml) (108.7 [31.9] v. 81 [26.7], p <0.01) and end-systolic volume (ml) (81.3 [30.9] v. 31.1 [10.7], p < 0.001); and significant improvement in the stroke volume (ml) 27.8 [13.2] v. 61.7 [6.2], p<0.001) and ejection fraction (%) (25.5 [12.8] v. 61.2 [6.5], p<0.001). All the patients responded well to treatment and none died. CONCLUSION: Our initial observations suggest a potential benefit with additional oral L-carnitine treatment in patients with myocardial toxicity caused by scorpion sting presenting with hypotension and severe LV dysfunction. These findings merit further study.

Adolescent↗

Cardiac sarcoidosis: an uncommon presentation of sarcoidosis in India.

Cardiac involvement in sarcoidosis is uncommon. The manifestations of cardiac sarcoidosis are protean and vary from benign ectopics to life threatening ventricular tachycardias. High index of suspcion and early aggressive intervention is required for the diagnosis and treatment of this condition. Early diagnosis is essential since ventricular tachycardia is the most common terminal event in these patients if left untreated. Corticosteroids are needed early in these patients which along with other antiarrhythmic management strategies including intracardiac defibrillator form the backbone of treatment. We describe four patients who were diagnosed to have pulmonary and cardiac sarcoidosis. Their varied presentations highlight the difficulties that may occur in the diagnosis. Furthermore, the need for proper management is stressed, as a delay in diagnosis may be fatal.

Adult↗