Artifical Blood.

Elimination of unwanted side-effects, especially transfusion-transmitted diseases (HIV and hepatitis) and leucocyte-mediated allosensitisation, is an important goal of modern transfusion medicine. The problems and high cost factor involved in collecting and storing human blood and the pending world-wide shortages are the other driving forces contributing towards the development of blood substitutes. Two major areas of research in this endeavour are haemoglobin-based oxygen carriers (HBOCs) and perfluorochemicals. Even though they do not qualify as perfect red blood cell substitutes, these 'oxygen carrying solutions' have many potential clinical and non clinical usages. These can reach tissues more easily than normal red cells and can deliver oxygen directly. These are not without adverse effects, and extensive clinical trials are being conducted to test their safety and efficacy. New understandings on the mode of action of these products will help to define their utility and application. Only after successful clinical trials can they be used for patient management, after approval by the FDA.

Tracheal lymphoepithelioma-like carcinoma: a case report.

Lymphoepithelioma like carcinoma is rare in locations other than nasopharynx. We report the second case of this tumour in trachea, in a young female patient, who was managed with concomitent surgery, radiotherapy and chemotherapy. The patient is disease free in the one-year follow up. The tumour presented difficulties during intubation for general anaesthesia and during surgery. Association with Epstein-Barr virus was not found in our case.

DNA AMPLIFICATION OF A REPETITIVE SEQUENCE - IS 6110 IN THE EARLY DIAGNOSIS OF EXTRA PULMONARY TUBERCULOSIS.

DNA amplification by Polymerase Chain Reaction (PCR) of a repetitive sequence specific for Mycobacterium tuberculosis, from clinical samples of extra pulmonary origin were evaluated. The 123 base pair fragment of the insertion element IS 6110 in Mycobacterium tuberculosis was amplified. A total of 50 samples were analysed by PCR and compared with culture on Lowenstein-Jensen medium (LJ) and the clinical findings of the patient. Out of the total 26 samples were positive by PCR, while only seven grew the bacilli in culture. 24 samples were negative by PCR and culture. All the seven samples that grew the bacilli on culture were positive by PCR. In remaining 19 cases that were positive by PCR but did not grow the bacilli clinical features, radiological findings and Mantoux test were strongly suggestive of M. tuberculosis. All the amplification negative cases had no positive evidence of tuberculosis but were being followed up. When correlated with culture and clinical history the sensitivity of PCR for the diagnosis of active tuberculosis was 100%. However, the specifity was only 55.8% as culture on LJ (Gold Standard) was positive in only 7 samples out of 26 samples that were positive by PCR.