Histological evolution of caecal lesions in experimental amoebiasis

Histopathological studies in guinea-pigs infected intracaecally with Entamoeba histolytica were carried out longitudinally on days 3, 7, 11, 15, 20 and 35 after infection. Three characteristic modes of development of caecal lesions were observed. These in order of their prevalence were the classical inflammatory cellular infiltration, lymphoid hypertrophy and necrotizing colitis. Occasional amoeboma formation was observed in progesterone-treated animals. This is the first time that histological lesions which mimic the human intestinal amoebiasis have been described in the experimental animal.     

Antibodies to respiratory syncytial virus in a normal community in Chandigarh area, northern India

A survey for the presence of respiratory syncytial (RS) virus antibodies has been carried out in 346 sera from a healthy community in northern India. The results showed that 19.6% of the sera were positive and had a titre of 16 or more. The higher titres were observed more frequently in the younger age groups. There is, therefore, serological evidence for the occurrence of RS virus infection in India.     

Macrophage functions in aging: effects of vitamin C deficiency

Groups of young adult and senescent guinea pigs were fed normal and vitamin C deficient diets for 4 weeks and tested for their peritoneal macrophage functions. Serum levels of vitamin C in deficient animals indicated a progressive state of ascorbic acid deficiency and correlated well with the clinical signs and symptoms of scurvy. Fewer macrophages were obtained from the peritoneal cavities of deficient animals and morphologically they were smaller in size. Adverse effects of vitamin C deficiency were enhanced in aged animals. Significantly greater number of aged animals died by 4 weeks of deficiency. Deficient senescent animals had greater decline in macrophage random migration and bactericidal capacity. Following phagocytic stimuli, superoxide anion generation also significantly decreased. Data suggest that vitamin C deficiency might affect macrophage functions in the aged more profoundly and could compromise parameters of host defenses effective against microbial infections.     

Serological response to cholera revaccination in a semi-closed community in Calcutta

Serological response to cholera revaccination has been studied in a semi-closed community consisting of individuals mostly in the 2-20-years age-group. The subjects had been inoculated against cholera every year at the beginning of the local epidemic season. Pre- and post-vaccination sera were obtained from 29 subjects inoculated with cholera vaccine (test group) and 28 from subjects inoculated with TAB vaccine (control group). These sera were tested for vibriocidal and agglutination titres. The geometrical means of the vibriocidal and agglutination titres of the post-vaccination sera in the test group rose by 490% and 463% respectively. This booster effect was observed mostly in individuals in the 2-14-years age-group, who had low titres (vibriocidal ≤320 and agglutination ≤40) in their prevaccination samples. Revaccination, therefore, appears to be useful as a booster for individuals having low titres.     

Anti-tremor action of C10Dichol, a peripheral acetylcholine synthesis inhibitor.

1 Anti-tremor action of decamethylene bis-(hydroxyethyl)-dimethylammonium bromide (C10Dichol), a peripheral acetylcholine synthesis inhibitor, was investigated. 2 C10Dichol inhibited tremor induced by oxotremorine, nicotine and physostigmine and afforded partial protection from physostigmine-induced mortality in mice. 3 In non-paralysing doses, C10Dichol antagonized the neuromuscular effects of oxotremorine, nicotine and physostigmine. 4 Prior administration of C10Dichol failed to prevent tremor and neuromuscular paralysis induced by harmine and arecoline. 5 In the absence of any antimuscarinic property of C10Dichol, its neuromuscular effects appeared to be casually related to its anti-tremor action. 6 This study reveals a possibility for the development of peripherally acting anti-Parkinson drugs.     

Polymerization of N-vinylearbazole with vanadium compounds. Part I. Polymerization with vanadium pentoxide and metal vanadates

Bulk polymerization of N-Vinylcarbazole (NVC) has been carried out using vanadium pentoxide as the contact catalyst. The rate of polymerizatlon has been found to depend upon catalyst to monomer ratio. A cationic mechanism has been suggested and the role of V₂O₅ surface in the polymerization has been tentatively analyzed. The π-acid characteristies of V^5⊕ ion is believed to be involved in initiating the polymerization. The effect of a number of additives on the polymerization rate has been studied, which endorses the cationic mechanism. The catalytic efficiency of a number of metal vanadates for the polymerization of NVC has also been studied. A fairly good correlation between the activity and electronegativity of the metallic moiety has been established.     

A novel in situ gel for sustained drug delivery and targeting

The objective of this study was to develop a novel chitosan-glyceryl monooleate (GMO) in situ gel system for sustained drug delivery and targeting. The delivery system consisted of 3% (w/v) chitosan and 3% (w/v) GMO in 0.33M citric acid. In situ gel was formed at a biological pH. In vitro release studies were conducted in Sorensen's phosphate buffer (pH 7.4) and drugs were analyzed either by HPLC or spectrophotometry. Characterization of the gel included the effect of cross-linker, determination of diffusion coefficient and water uptake by thermogravimetric analysis (TGA). Mucoadhesive property of the gel was evaluated in vitro using an EZ-Tester. Incorporation of a cross-linker (glutaraldehyde) retarded the rate and extent of drug release. The in vitro release can further be sustained by replacing the free drug with drug-encapsulated microspheres. Drug release from the gel followed a matrix diffusion controlled mechanism. Inclusion of GMO enhanced the mucoadhesive property of chitosan by three- to sevenfold. This novel in situ gel system can be useful in the sustained delivery of drugs via oral as well as parenteral routes.