Usefulness of stereotactic biopsy and neuroimaging in management of HIV-1 Clade C associated focal brain lesions with special focus on cerebral toxoplasmosis.

BACKGROUND: Focal brain lesions (FBL) in HIV/AIDS frequently pose a diagnostic dilemma as the etiology varies from infective (tuberculoma, toxoplasmosis and tuberculous abscesses) to neoplastic lesions like lymphoma. For determining etiology, advanced neuroimaging techniques, serological and molecular biological tests have been evolved with varying sensitivities/specificities. Stereotactic biopsy (STB) of the lesions is reserved for lesions unresponsive to appropriate therapy. OBJECTIVE AND METHODS: In this study, the diagnostic yield of neuroimaging [cranial CT (n=25), MRI (n=24), and Th201/99Tc SPECT scan (n=18)] is compared with histopathological diagnosis obtained by STB (n=21) or autopsy (n=4) in 25 HIV-1 subtype C seropositive individuals with FBL identified by neuroimaging with special reference to cerebral toxoplasmosis in an eighteen month study period (2006-2007). RESULTS AND CONCLUSION: Cerebral toxoplasmosis was the most frequent cause of FBL (21/25, 84%), followed by one case each of tuberculoma, progressive multifocal leukoencephalopathy (PML), primary central nervous system lymphoma (PCNSL) and measles inclusion body encephalitis (MIBE), the last two diagnosed at autopsy. Of the 21 cases of cerebral toxoplasmosis, definitive diagnosis with histopathological confirmation was available in 14/21 (66.6%), with indirect evidence suggesting probable toxoplasmosis in seven, all of whom responded to antitoxoplasma therapy. CT and MRI had comparable specificities (75%), while MRI had marginally higher sensitivity (85% versus 80.9%) in detecting multiple lesions. The positive predictive value of both CT and MRI was identical (94.4%), suggesting that CT maybe a cost effective screening tool in resource restricted settings, for evaluating FBL. Sensitivity of 99Tc SPECT scan for diagnosing inflammatory lesions was 75% but failed to differentiate PCNSL from toxoplasmosis. This study is the first of its kind from India analyzing FBL with specific focus on cerebral toxoplasmosis in the setting of HIV-1 subtype C.

Development of meat-bone separator for small scale fish processing.

The belt and drum type meat-bone separator was developed for small-scale fish processing and evaluated using Tilapia fish (Oreochromis mossambicus) in terms of capacity, yield, percentage yield, bone content, colour and power consumption. It consists of a perforated drum (3 mm), single phase electric motor, speed reduction gear box and drive system. The machine was evaluated using two food grade belt viz., natural rubber (Belt A-35 shore) and canvas belt (Belt B-65 shore) for three drum speeds. The machine capacity was in the range of 45.59 to 68.54 kg h(-1) for belt A with a yield of 1.148, 1.069 and 1.066 kg, and 49.13 to 78.13 kg h(-1) for belt B with a yield of 1.253, 1.312 and 1.269 kg at drum speeds of 14, 20 and 24 rpm, respectively. For belt A, the highest yield (1.148 kg) was obtained at 14 rpm drum speed which was 63.78% on dressed weight basis and for belt B, the highest yield (1.312 kg) was obtained at 20 rpm drum speed which was 72.89% on dressed weight basis. The increased number of passes for meat recovery increased the chances of insertion of bone fragments into minced meat and decreased the colour values (L-a-b). The total energy consumption did not vary significantly.