Enzyme-linked immunosorbent-assay for antigen detection in tuberculous meningitis.

Two systems of Competitive Enzyme linked immunosorbent assay (ELISA) were developed to detect Mycobacterial antigen in cerebrospinal fluid (CSF) for the diagnosis of tuberculous meningitis (TBM)--one by using indigenously prepared Anti-M.tuberculosis H37Rv-Penicillinase conjugate (Method I) and another by using commercially available Anti M. bovis BCG-Horse Radish Peroxidase (HRP) conjugate--(Method II). The tests were used to analyse CSF of 148 patients clinically confirmed as having TBM and 278 control subjects. By using > or = 10 ng/ml as the cut-off value for Method I and > or = 1 ng/ml as that for Method II, the specificity for both were 100% and positivity was 79.73% and 67.57% respectively. A follow up study in 26 TBM cases after 2 weeks (16 cases), 4 weeks (13 cases) and 4-12 months (10 cases) of antituberculous treatment revealed that mycobacterial antigen persisted in the majority of cases even after 4 weeks of the treatment.

Diagnosis of peripheral arterial occlusive diseases using impedance plethysmography.

Impedance plethysmographic observations have been compared with arteriographic findings in 216 patients with peripheral arterial occlusive diseases. Impedance plethysmographic diagnosis in these patients was obtained by Parulkar's method without apriori knowledge of arteriographic diagnosis. But for minor discrepancy in the anatomical location of the block in few patients, impedance plethysmographic observations correlated very well with arteriographic findings. Impedance plethysmographic diagnosis was found to be correct in 312, wrong in 53, false negative in 8 limbs respectively, yielding a sensitivity of 97.5% and specificity of 98.1% of this technique.

Diagnosis of aortic occlusive diseases using impedance plethysmography.

Impedance plethysmographic observations have been correlated with aortographic observations in 57 patients suspected of aortic occlusive diseases. Aortic occlusions have been characterised by marked decrease in blood flow index and significant increase in differential pulse arrival time at thigh level bilaterally. Atherosclerotic affection of the aorta has been featured by a bilateral decrease in the value of blood flow index as well as differential pulse arrival time at thigh level. Leriche's syndrome, however, has been found to decrease the blood flow index moderately at thigh in both the legs without any significant change in differential pulse arrival time. Aortography in all the patients has confirmed the diagnosis made by impedance plethysmography.