Synthesis of biocompatible hydrophobic silica-gelatin nano-hybrid by sol-gel process.

Silica-biopolymer hybrid has been synthesised using colloidal silica as the precursor for silica and gelatin as the biopolymer counterpart. The surface modification of the hybrid material has been done with methyltrimethoxysilane leading to the formation of biocompatible hydrophobic silica-gelatin hybrid. Here we are reporting hydrophobic silica-gelatin hybrid and coating precursor for the first time. The hybrid gel has been evaluated for chemical modification, thermal degradation, hydrophobicity, particle size, transparency under the UV-visible region and morphology. FTIR spectroscopy has been used to verify the presence of CH(3) groups which introduce hydrophobicity to the SiO2-MTMS-gelatin hybrids. The hydrophobic property has also been tailored by varying the concentration of methyltrimethoxysilane. Contact angle by Wilhelmy plate method of transparent hydrophobic silica-gelatin coatings has been found to be as high as approximately 95 degrees . Oxidation of the organic group which induces the hydrophobic character occurs at 530 degrees C which indicates that the surface hydrophobicity is retained up to that temperature. Optical transmittance of SiO2-MTMS-gelatin hybrid coatings on glass substrates has been found to be close to 100% which will enable the hybrid for possible optical applications and also for preparation of transparent biocompatible hydrophobic coatings on biological substrates such as leather.

High prevalence of HTLV antibodies in wild-caught bonnet monkeys in southern India.

The prevalence of human T-lymphotropic virus (HTLV) type-1 antibodies was determined in the bonnet monkeys, living naturally, within about 30 km radius of Vellore (south India). Sera from 157 animals, collected between January 1982 and May 1993 were screened for the presence of HTLV-I infection by a particle agglutination test (PAT). When sera repeatedly reactive in PAT were subjected to indirect immunofluorescence and western blot tests, 63 (40%) were confirmed to be positive for HTLV-1 antibody. These findings are significant in the light of recent reports that HTLV infection is endemic to southern India.

Immune response to purified chick embryo cell culture rabies vaccine manufactured in India.

The immunogenic efficacy of the first batch of indigenous purified chick embryo cell culture grown (PCEC) rabies virus vaccine has been measured in ten subjects. All of them were immunologically naive to rabies virus, and were given 5 doses of the vaccine in the post-exposure regime of injections on days 0, 3, 7, 14 and 30. On day 7, four subjects had developed very low levels of rabies virus neutralizing antibody, as detected and measured in the suckling mouse neutralization test. On day 14, all subjects had protective levels of antibody, which were maintained or enhanced by day 30. With the limited data presented here, the immunogenic efficacy of this batch of vaccine appeared similar to that of a batch of imported PCEC vaccine investigated earlier.

Immune response to intradermally injected inactivated poliovirus vaccine.

Immune response to intradermal inoculation of a fractional dose of inactivated poliovirus vaccine (IPV) was measured in 8 adults and 10 children who were previously immune. A striking 4-fold to 1024-fold antibody booster response to all 3 poliovirus serotypes was found in 15 subjects and a similar response to 2 poliovirus serotypes occurred in the other 3 children. Induration and erythema of 3 mm diameter or above, indicative of a cell-mediated immune response, was seen in 12 subjects. Intradermal inoculation of IPV may be a useful technique for secondary immunisation programmes against polio and its use for primary immunisation merits investigation.

High incidence of subacute sclerosing panencephalitis in south India.

During 1983-7 a clinical diagnosis of subacute sclerosing panencephalitis (SSPE) was confirmed by the detection of measles virus haemagglutination inhibiting antibody in the cerebrospinal fluid (CSF) in 81 subjects resident in Tamilnadu. The antibody titre (reciprocol of the end-point dilution) in the CSF ranged from 2 to 32 and in the sera from 8 to 2048. The CSF:serum ratios of titres were 1:4-1:64 in 80 cases and 1:128 in one case. The median age at onset of SSPE was 10 years and 97% of cases were diagnosed at stage 2 and beyond. Based on the geographic distribution of 72 cases in an estimated population of 8.4 million, the annual incidence of SSPE was calculated to be 2.14 per million population, or 4.3 cases per million children below 20 years. Assuming that only 10% of all cases would have reached the level of laboratory diagnosis, the incidence may be as high as 21 cases per million population.

Coxsackie virus A 24 variant as the etiological agent of the acute haemorrhagic conjunctivitis epidemic at Vellore, in 1986.

Coxsackie virus A 24 variant (CA24v) was found to be the etiological agent of an epidemic of acute haemorrhagic conjunctivitis (AHC) in Vellore during the months of October and November in 1986. CA24v was isolated in 21 of 25 acutely ill patients. In addition, seroconversion was seen in 11 of the 16 patients from whom paired sera were collected.

Lack of relationship between viruses and human diabetes mellitus.

Antibodies titres against Coxsackie-B (CB) and mumps virus (MV) were determined in 180 normal subjects and two groups of diabetics, 236 with diabetes of recent onset (DRO) and 108 with diabetes of long duration (DLD). Positive antibody titres to these viruses were found more frequently in controls than in diabetics. In fact, the percentage of positive titres was significantly less than in controls in several instances particularly in juvenile onset diabetes of long duration. These data suggest that CB and MV are not causally related to human diabetes mellitus.