Influence of dietary myoinositol on nerve conduction and inositol phospholipids in normal and diabetic rats

Observations have been made on motor conduction velocity in the tibial nerve of rats given 35% myoinositol in the diet. Comparison between the values before and with up to nine weeks of dosing revealed no alteration in conduction velocity. In such animals, the free myoinositol content in the sciatic nerve was increased; there was no detectable alteration in the lipid inositol concentration. In a second series of experiments, tibial motor nerve conduction velocity in rats with streptozotocin-induced diabetes was compared with conduction velocity in diabetic animals given 1% supplementary dietary myoinositol, and with a control group of nondiabetic rats. Conduction velocity was reduced in the diabetic animals, but no influence from the added dietary myoinositol was detected. No statistically significantly difference in sciatic nerve myoinositol was demonstrated, but the sorbitol and fructose concentrations were increased. Those animals fed the myoinositol supplement had a significantly lower lipid inositol content. The significance of these findings is discussed.

Circulating T-cell numbers and their mitogenic potential in leprosy--correlation with mycobacterial load

The effect of treatment and mycobacterial load on circulating T-cell numbers and their functional ability was investigated in forty-one patients with leprosy. Both early binding T cells and their responses to phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM) were profoundly and uniformly depressed in untreated, and partially treated, bacilleferous lepromatous leprosy (LL) patients as compared with normal subjects and tuberculoid patients. On elimination of mycobacteria, subsequent to chemotherapy, LL patients regain normality in T-cell numbers and their functions. On the other hand, the specific response of lymphocytes to M. leprae did not alter with decrease in mycobacterial load. It appears that the decrease in T-cell numbers and the deficit in their mitogenic potential is a secondary consequence of disease and is related to the antigenic load in patients with lepromatous leprosy.

Peripheral nerve fiber size in experimental diabetes

Serial morphometric observations were made on the tibial nerves of mature rats before and five weeks after the induction of diabetes by streptozotocin. Maximum and average myelinated fiber diameter did alter, neither did the relationship between myelin sheath thickness and axon circumference. This confirms previous observations suggesting that the reduced nerve conduction velocity that is known to occur in experimental diabetes is likely to depend on metabolic alterations rather than on structural changes.

Peripheral nerve abnormalities related to galactose administration in rats

Electrophysiological, biochemical, and morphometric observations were made on the peripheral nerves of rats after galactose feeding. Motor nerve conduction velocity was found to be reduced. This was associated with an accumulation of galactitol in the peripheral nerves and a diminution in their myoinositol content. An increased water content and fascicular area, taken in conjunction with a probable increase in the area of the endoneurial spaces, indicated overhydration of the peripheral nerves. Morphometric observations on the myelinated fibre population in the tibial nerve showed no loss of fibres and although both the maximal and the average diameter of the myelinated fibres was slightly less than in age-matched controls, this was insufficient to explain the reduction in conduction velocity. Segmental demyelination was not detected and the relationship between myelin thickness and axon circumference was not altered. Electron microscope observations revealed no ultrastructural changes in the myelinated fibres and, in particular, no abnormalities at the nodes of Ranvier or indication of abnormal hydration of the Schwann cells. The relevance of these findings to the peripheral nerve changes in human and experimental diabetes is discussed.

Comparative studies on different small intestinal oligosaccharidase activities in some vertebrates and invertebrates like molluscs

Oligosaccharidase activities of the small intestinal mucosal homogenates were measured in vertebrates viz fish, toad, garden-lizard (calotes), pigeon, rat and some invertebrates viz, molluscsa. Maximum activities of the enzymes Lactase, Sucrase and Maltase were found in the mammalian species rat, whereas much less activities were found in the non-mammalian vertebrates among which toad shows the highest values and garden lizard the lowest. Among the invertebrates Pila globosa shows higher values of all the enzymes than Achatina fulica. The results obtained have been discussed in the lights of phylogeny and diet habits.

Studies on the effect of penicillin, streptomycin and isonicotinic acid hydrazide on small intestinal oligosaccharidase

Studies have been done on the effect of Penicillin, Streptomycin and Isonicotinic Acid hydrazide on small intestinal oligosaccharidase and it was observed that the drug penicillin inhibited the enzyme lactase and sucrase by 62.7% and 34.7% respectively, whereas I.N.H. inhibited the enzyme sucrase and maltase by 57.1% and 56.14% respectively. Streptomycin did not show any inhibitory effect on those enzymes. Lactose tolerance test showed impairment of lactose absorption in case of penicillin. Fasting serum sugar level was diminished both in penicillin and streptomycin and the absorption capacity was increased after oral administration of streptomycin.

Peripheral nerve regeneration in experimental diabetes

Observations have been made on the regeneration of myelinated fibres in the sural nerve of streptozotocin-induced diabetic rats and age-matched non-diabetic control animals at 3, 6 and 18 weeks after a localized crush lesion. Morphometric studies on the regenerated fibres revealed no differences in the total fibre count, size-frequency distribution or average diameter at 18 weeks after injury. The degree of myelination was assessed by relating the number of myelin lamellae to axon circumference. The relationship was found to be approximately linear. There was a possible slight lag in myelination at 3 weeks after injury in the diabetic animal, but no difference was detectable at 6 and 18 weeks after injury.

Oesophageal Perforation

NA