Status of antioxidants in brain microvessels of monkey and rat

Levels of certain antioxidants namely reduced glutathione (GSH), ascorbic acid (Vit C), alpha-tocopherol (Vit E) and antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) were compared in monkey and rat brain microvessels which constitute the blood-brain barrier (BBB). The BBB of both the species contains appreciable amounts of the antioxidants to protect against oxidative damage. The level of protection in rat seems to be more efficient than monkey since rat microvessels contain higher concentrations of some of the bio-antioxidants. The comparative status of enzymatic and non-enzymatic protective system against oxidation in the brain microvessels has been discussed.

Allergic fungal sinusitis: incidence and clinical and pathological features of seven cases

Allergic fungal sinusitis, like allergic bronchopulmonary fungal disease, is a noninvasive inflammatory process. It manifests as recurrent nasal polyposis. Histologically the characteristic feature is the presence of thick mucin with dense collections of degenerating eosinophils and Charcot-Leyden crystals (allergic mucin). Demonstration of fungal hyphae in allergic mucin is diagnostic of the disease. We reviewed 85 cases of nasal polyposis operated upon during a period of four years. Allergic fungal sinusitis was diagnosed in seven (8.2%) cases on the basis of presence of allergic mucin and fungal hyphae. History of previous nasal polypectomy was present in four of the seven cases, and in six of the remaining 78. There were no clinical or radiological features that could distinguish the cases of allergic fungal sinusitis from the rest. Aspergillus fumigatus, Mucor and Cladosporium were cultured from one case each.

Evaluation of vanillic acid analogues as a new class of antifilarial agents

A number of vanillic acid analogues (1-14) have been synthesised and evaluated against experimental filarial infections using cotton rats (Sigmodon hispidus) infected with Litomosoides carinii, a primary screening model, at a dose of 30 mg/kg, ip for 5 days. Of the 8 compounds tested, 4 (5,7, 11 and 12) exhibited high micro- and macro-filaricidal activity with sterilization of surviving female worms. Compounds 5, 7, 12 showed remarkable adulticidal action (> 80%). Sterilization of the female worms by compounds 11 and 12 was highly significant (80-100%).

Alterations in free radical scavenging mechanisms following blood-brain barrier disruption

It has been reported earlier that rat microvessels which constitute the blood-brain barrier (BBB) are rich in free radical scavenging enzymes. In the present investigation, BBB of rat was disrupted by intravenous infusion of the hypertonic saline and changes in enzymes--namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR)--were evaluated in the brain microvessels at 30 min after the intravenous administration of hypertonic saline, being the time of peak effect. There was a significant increase in the activities of CAT (40%), GPx (26%), and SOD (16%) over the control values. In addition, within 90 min BBB was found to be reestablished and the levels of enzymes reverted to normal. Malondialdehyde (MDA) levels and activity of lactate dehydrogenase (LDH) remained unaltered during and following disruption, suggesting that there was no change in the membrane lipid environment. Similarly, there was no cell lysis. The results suggest that the disruption of BBB following hypertonic saline administration might be due to an increase in the generation of free radicals in the brain microvessels.

Phenotype of 49,XXYYY

A 7-year-old boy with 49,XXYYY karyotype is reported. Physical examination revealed facial dysmorphism, mild microcephaly, limitation of supination at the elbows, delayed bone age and moderate mental retardation.

Electrophysiologic basis of dynamic extensor splinting

The use of dynamic extension splinting in the rehabilitation of extensor tendon injuries is gaining interest because of its apparent ability to improve clinical results. With such splinting, the extensor musculature is theoretically quiescent during both active flexion and rubber band-mediated extension; the gliding produced thereby decreases adhesion formation. Our initial intent was to perform electromyographic studies on volunteers in dynamic extension splinting to test this electrophysiologic principle. It was found, however, that only 16% of normal volunteers have quiescent extensor digitorum communis muscle activity within the dynamic extension splint typically used in this type of rehabilitation. A second splint was developed with a dorsal hood to keep the metacarpophalangeal joints in approximately 15 degrees of flexion. In this splint, 18 of 19 volunteers (95%) showed no extensor activity. The explanation for this phenomenon is not yet clear, but it shows that splint design plays a more significant role than previously expected. The expected electrophysiologic principle of dynamic extension splinting for extensor tendon injuries has been validated, but only in a splint design that is not commonly used.

Control of kidney size by sex hormones: possible involvement of glucosylceramide

Because androgenic hormones produce an increase in kidney size and the production of kidney glycosphingolipids and because the level of tissue glucosylceramide (GlcCer) has been implicated as a modulator of organ size, we measured the activities of two enzymes in mouse kidney that (in part) determine the level of this glycolipid. GlcCer synthase was found to rise in specific activity with age and increased kidney size, whereas GlcCer glucosidase was found to decrease with age; both enzyme changes act to elevate the level of kidney GlcCer and point to the level of this lipid as a determinant of kidney size. The increase in synthase was especially rapid in male kidney, consistent with the more rapid growth of male kidney. Testosterone injection into both males and females produced elevated levels of GlcCer synthase, decreased levels of the hydrolase, and more rapid growth. Injection of 17 beta-estradiol, which produced slow or negative kidney growth, caused the synthase activity to decrease in female mouse kidney and the glucosidase activity to rise in both sexes. Thus the changes in kidney size produced by the two hormones paralleled the changes in GlcCer level predicted by the hormone effects on the two enzymes. In liver, estradiol produced increases in both enzymes but only the male liver increased in size. Testosterone did not affect the liver. The testes grew with age but the activities of both enzymes decreased.

The effects of long-term non-fatiguing resistance exercise in subjects with post-polio syndrome

Measures of torque were used to evaluate changes in muscle strength and endurance in 17 patients with post-polio syndrome who did prescribed resistance exercise for up to 2 years. Exercise compliance averaged 75%, with 16 subjects increasing the weight lifted in training. Maximum torque was significantly increased in the exercised muscle compared to the control muscle; no difference was seen in muscle endurance. Individuals with post-polio syndrome can increase muscle strength by doing non-fatiguing resistance exercise, but they should undergo quantitative testing of muscle strength a minimum of every 3 months to guard against overwork weakness.

Spontaneous gastrointestinal perforation in the neonate

Twenty seven cases of spontaneous gastro-intestinal perforation were treated from 1981 to 1990. Four perforations were in the stomach, 17 in the small bowel and seven in the large bowel. One of them had dual perforation, one in the stomach and another in the duodenum. The exact etiology remained obscure. Various factors observed were maternal obstetric complications, prematurity and perinatal asphyxia. Stress should be laid on early diagnosis by following up 'at risk neonates' thus, giving a better overall survival rate.

Cytogenetic studies in Down syndrome

Cytogenetic studies were carried out in 645 patients with Down syndrome. Free trisomy of chromosome 21 was present in 600 cases (93%). Translocation karyotypes were observed in 26 cases (4%). Seventeen patients (2.6%) had mosaicism. Two (0.3%) patients had additional karyotypic abnormalities along with trisomy 21.

Gangliosides inhibit glucosylceramide synthase: a possible role in ganglioside therapy

Gangliosides stimulate the hydrolysis of glucosylceramide (GlcCer), their precursor, and therefore may lower the level of cellular GlcCer and exert a feedback control effect to slow the formation of gangliosides. Tests were made to see if a similar effect on GlcCer levels can be exerted by the action of gangliosides on GlcCer synthesis. Using a new assay procedure, we showed that gangliosides do inhibit the synthase in brain membranes quite effectively, the most active being those lipids with more sugar and sialic acid moieties. Mice injected with a mixture of brain gangliosides for 5 days were found to have a lower level of ceramide:UDP-Glc glucosyltransferase activity in brain, liver, and kidney. The inhibition seems to be exerted by competition for the active site and binding to effector site(s) on the enzyme. It is possible that the reported therapeutic actions of gangliosides on the nervous system are, in part, the result of lowered levels of GlcCer. Malignant tumors shed gangliosides into the extracellular fluid, which are believed to block the generation of antibodies by the host's immunodefense system; this effect also may be due, in part, to reduction in the GlcCer level of immunogenic cells. A new finding is that a ceramide containing phytosphingosine is a markedly better substrate for GlcCer synthase than one containing the more common base.

Rapid kidney changes resulting from glycosphingolipid depletion by treatment with a glucosyltransferase inhibitor

The ceramide analog, D-threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol, inhibits the glucosylation of ceramide and thus, by virtue of the normal catabolism of the higher glucosphingolipids, leads to a general depletion of cellular glucolipids. In a previous study with chronic administration of this inhibitor in mice, it was found that the kidneys and liver, particularly the former, grew more poorly than the organs of control mice. This study shows that the inhibitor produces rapid decreases in glucolipid concentration in kidney which are maintained for at least 5 days without noticeable harm. The changes were enhanced by inclusion of L-cycloserine in the injection scheme. Cycloserine blocks ketosphinganine synthase and thus slows the synthesis of all sphingolipids. However, sphingomyelin levels did not drop significantly in this study. The glucosyltransferase inhibitor also produced a small decrease in kidney beta-D-glucuronidase and distinct increases in the levels of glucocerebrosidase, galactocerebrosidase and sphingomyelinase. It also produced a small but distinct decrease in the level of glucosyltransferase, after a delay of a few hours, possibly because the inhibitor was metabolized to a covalently inactivating product. Comparison with kidney, liver and brain showed that the kidney was more sensitive to the action of the morpholino inhibitor.