Evaluation of lipid peroxidation product, nitrite and antioxidant levels in newly diagnosed and two months follow-up patients with pulmonary tuberculosis.

This case-control study followed by a longitudinal cohort study was undertaken to evaluate the level of lipid peroxidation product malondialdehyde (MDA) and nitrite as an indirect measurement of nitric oxide vis-à-vis the levels of antioxidants vitamin C and vitamin E in pulmonary tuberculosis. Fifty-six sputum smear-positive cases of pulmonary tuberculosis based on Ziehl-Neelsen (ZN) staining and 50 healthy controls without any systemic disease were included in this study. Thirty-five cases were longitudinally followed up with standard antituberculosis chemotherapy (ATT) for two months. Serum levels of malondiadehyde (MDA), nitrite, and plasma levels of vitamins C and E were measured. The mean serum MDA level was significantly higher (8.1 +/- 1.61 nmoles/ml) in PTB patients before commencement of ATT as compared to healthy controls (3.45 +/- 1.7 nmoles/ml) (p=0.0001) and decreased significantly after 2 months of ATT (3.84 +/- 1.28 nmoles/ml) (p=0.0001). The mean serum nitrite level (47.19 +/- 18.44 micromol/l) was significantly elevated before ATT compared to healthy controls (32.89 +/- 11.94 micromoles/l) and decreased significantly after 2 months of ATT (27.71 +/- 11.97 micromoles/l) (p=0.0001). The mean plasma levels of vitamins C (0.88 +/- 0.33 mg/dl) and E (0.79 +/- 0.24 mg/dl) in PTB patients before commencement of ATT were lower than healthy controls (1.42 +/- 0.38 mg/dl) and (1.35 +/- 0.35 mg/dl), respectively (p=0.001). There was a significant increase in vitamin C levels after 2 months of ATT (1.19 +/- 0.40 mg/dl) compared to before ATT (0.83 +/- 0.31 mg/dl) (p=0.0001), but no significant change in mean plasma vitamin E level before and after 2 months on ATT was found. Elevated malondialdehyde and nitrite levels with concomitant depressed vitamin C and E levels are indicative of lipid peroxidation and oxidative stress. The decrease in levels of malondialdehyde and nitrite with subsequent increase in vitamin C levels after two months of follow-up indicate a good response to treatment with standard ATT. Hence, the extent of oxidative stress in PTB can be evaluated by analyzing lipid peroxidation product, antioxidant and nitric oxide levels.

Comparative study of cerebrospinal fluid adenosine deaminase activity in patients with meningitis.

Cerebrospinal fluid (CSF) adenosine deaminase (ADA) activity in tubercular meningitis (TBM) patients (n=20), non-tubercular meningitis (NTBM) patients (n=10) and non-tubercular non-meningitis (NTBNM) cases (n=15) were measured by the method based on Berthlot's reaction. The mean CSF ADA activity in TBM (13.62 +/- 8.45 IU/L) was found to be significantly higher as compared to NTBM (6.51 +/- 2.41 IU/ L, p<0.001) and NTBNM (2.35 +/- 1.16 IU/L, p<0.0001) respectively. The sensitivity and specificity of CSF ADA activity was 85.0% and 88.0% respectively at cut-off value of 6.97 IU/L to diagnose tubercular meningitis. The specificity and sensitivity of CSF ADA for TBM was found to be 85.0% and 70.0% as compared to NTBM and 85.0% and 100.0% as compared to NTBNM. We propose that estimation of that ADA activity in CSF of TBM patients, using a cut off value 6.97 IU/L can diagnose differentially tubercular meningitis. Since, most developing countries have the dubious distinction of having higher prevalence and incidence of tubeculosis and lack of well equipped laboratory services for proper diagnosis of tubercular meningitis, measurement of CSF ADA activity can be a better and reliable approach for the rapid diagnosis and management of tubercular meningitis vis a vis other types of meningitis.

Diagnostic utility of adenosine deaminase (ADA) activity in pleural fluid and serum of tuberculous and non-tuberculous respiratory disease patients.

Adenosine deaminase activity (ADA) was assayed in pleural fluid and serum of 42 subjects with pleural effusion. Twenty-nine of them had TB pleural effusion and the remaining 13 had pleural effusion due to non-TB respiratory diseases. Serum adenosine deaminase activity were also measured in 32 pulmonary tuberculosis patients without pleural effusion and equal numbers of healthy controls without systemic diseases for comparative analysis. The patients attending the medicine out-patient department (MOPD) of the B. P. Koirala Institute of Health Sciences, Dharan, Nepal were taken as study subjects. Serum and pleural fluid ADA activities were assayed spectrophotometrically by the method of Guisti and Gallanti. The mean serum ADA activity was significantly increased in patients with tubercular pleural effusion (34.53 +/- 10.27 IU/l) compared to pulmonary tuberculosis patients without pleural effusion (26.54 +/- 4.76 IU/l), (p = 0.004), those with non-TB respiratory disease (16.71 +/- 5.16 IU/l), (p = 0.0001) and healthy controls (15.53 +/- 4.4 IU/l) (p = 0.0001). The mean ADA in the pleural fluid of tubercular pleural effusion patients (90.29 +/- 54.80 IU/l) was significantly higher compared to those with non-TB respiratory disease (24.43 +/- 9.28 IU/l) (p = 0.0001). Using the lowest cutoff value for enzyme activity in the serum of patients with TB pleural effusion (25 IU/l), a test sensitivity of 72.41% and specificity of 81.53% were obtained. Using the lowest cutoff value for enzyme activity in pleural fluid of patients with TB pleural effusion (45 IU/l) the sensitivity and specificity for diagnosis were 76.10% and 100%, respectively. Therefore, the measurement of ADA in tubercular pleural effusion has a utility in the diagnosis of tuberculosis when other clinical and laboratory tests are negative.

Primary pulmonary lymphoma presenting as lung mass.

The commonest cause of lung mass in an elderly patient is bronchogenic carcinoma. We are reporting an unusual case of lung mass that was diagnosed following exploratory thoracotomy and pneumonectomy. Sputum examination, bronchoscopy and percutaneous fine needle aspiration cytology were inconclusive. On histopathology, a diagnosis of non-Hodgkin's lymphoma (NHL) was made. There was no involvement of any other site on detailed work up. The patient was advised chemotherapy.

Non-invasive ventilation: current status.

Mechanical ventilation is being increasingly used in many disciplines by specialists who manage critically ill patients. Non-invasive ventilation (NIV) refers to the method of providing assisted ventilation without endotracheal intubation. This technique requires a positive-pressure ventilator, connected by a tubing to an interface device that directs intermittent positive pressure through the upper airway and actively assists ventilation. The use of NIV is increasing for patients with acute and chronic respiratory failure, because of its convenience, lower cost and minimal complications. The greatest advantage of NIV is that endotracheal intubation is not required. Although it is an extremely useful technique, it cannot be used in all patients and correct patient selection is important. It has been extensively used in patients with chronic obstructive pulmonary disease with acute or acute-on-chronic respiratory failure. It has also been found to be useful in acute respiratory distress syndrome, acute cardiogenic pulmonary oedema and acute severe asthma. All patients with respiratory failure need to be considered for NIV if they fulfil the requisite criteria. Patients who are unable to protect the upper airway, those with severe life-threatening hypoxaemia, or major associated organ dysfunction are unlikely to benefit from this technique. Despite these limitations, NIV can be useful in many conditions that lead to respiratory failure. NIV is a relatively new technique and has not found a place in all intensive care units. It is expected that this modality will be used more frequently in the near future.

Outdoor air pollution and emergency room visits at a hospital in Delhi.

Several reports from large metropolitan cities have indicated significant association between acute morbidity and mortality from cardio-respiratory disorders and daily levels of major pollutants in the ambient air. Despite the wide-spread public concern about the adverse health effects of air pollution, there is substantial uncertainty regarding the effects of these pollutants at a concentration typical of Delhi, which is one of the ten most polluted cities in the world and the most polluted city in India. This study was undertaken to correlate the daily levels of various pollutants with the number of patients visiting the All India Institute of Medical Sciences (AIIMS, New Delhi) casualty for aggravation of certain defined cardiorespiratory disorders. Daily counts of patients visiting the emergency room of the AIIMS for acute asthma, acute exacerbation of chronic obstructive airway disease (COAD) and acute coronary event was obtained in prospective manner from January 1997 to December 1998. Daily mean levels of ambient CO, NOx and SO2 were monitored along with temperature and humidity. Data was analysed using one day time lag for events of interest. Time series analysis was undertaken using Poisson regression and population averaged general estimation equation, correcting for auto-correlation, days of the weak and season. The ambient levels of pollutants exceeded the national air quality standards on most of the days, over the two year period. Further, emergency room visits for asthma, COAD and acute coronary events increased by 21.30%, 24.90% and 24.30% respectively on account of higher than acceptable levels of pollutants. It is concluded that there is considerable burden of cardiorespiratory diseases in Delhi due to high levels of ambient air pollution.