Recurrent Kawasaki disease

We describe an infant who had recurrence of Kawasaki disease and responded to therapy with Intravenous Immune globulin (IVIG) and highlight the need for recognition of this vasculitis, which is being increasingly recognised in the Indian subcontinent.     

Retina is structured to process an excess of darkness in natural scenes

Retinal ganglion cells that respond selectively to a dark spot on a brighter background (OFF cells) have smaller dendritic fields than their ON counterparts and are more numerous. OFF cells also branch more densely, and thus collect more synapses per visual angle. That the retina devotes more resources to processing dark contrasts predicts that natural images contain more dark information. We confirm this across a range of spatial scales and trace the origin of this phenomenon to the statistical structure of natural scenes. We show that the optimal mosaics for encoding natural images are also asymmetric, with OFF elements smaller and more numerous, matching retinal structure. Finally, the concentration of synapses within a dendritic field matches the information content, suggesting a simple principle to connect a concrete fact of neuroanatomy with the abstract concept of information: equal synapses for equal bits.     

Synthesis and antimicrobial activities of N-chloroacetyl-2,6-diarylpiperidin-4-ones

An array of new N-chloroacetyl-2,6-diarylpiperidin-4-ones has been synthesised and their antibacterial activity against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa, and Salmonella typhi, and antifungal activity against Cryptococcus neoformans, Candida albicans, Rhizopus sp., Aspergillus flavus, and Aspergillus niger examined. Compounds 14 against P. aeruginosa, 15 against S. typhi, 16 against S. aureus, and 19 against B. subtilis showed marked antibacterial activity. Similarly, compounds 15 and 19 against A. niger and 19 against A. flavus exerted significant antifungal activities.     

Gunshot wounds in children under 10 years of age. A new epidemic

Before 1980 we had not treated any children with gunshot wounds who were younger than 10 years of age, but the number has increased dramatically each year since then. Thirty-four children younger than 10 years of age were treated for gunshot wounds from 1980 to 1987. Sociologic and epidemiologic data were assessed by a child-abuse team and police. Other studies have concluded that gunshot wounds in young children were usually caused by unintentional injury, child abuse, or neglect. From our present study we add a further, and very disturbing, category, that of attempted or intentional pediatric homicide. The children in this category were shot in retaliation for gang activities of their older siblings. This study demonstrates that the majority of our patients' childhood gunshot wounds were related to gang violence and retaliation, the availability of handguns in the home, and child neglect. The prevalence of childhood gunshot wounds in the inner city is increasing dramatically.     

Verbal autopsy of 48 000 adult deaths attributable to medical causes in Chennai (formerly Madras), India

Background

In the city of Chennai, India, registration of the fact of death is almost complete but the cause of death is often inadequately recorded on the death certificate. A special verbal autopsy (VA) study of 48 000 adult deaths in Chennai during 1995–97 was conducted to arrive at the probable underlying cause of death and to measure cause specific mortality rates for Chennai.

Methods

Trained non-medical graduates with at least 15 years of formal education interviewed the surviving family members or an associate of the deceased to write a report on the complaints, symptoms, signs, duration and treatment details of illness prior to death. Each report was reviewed centrally by two physicians independently. The reliability was assessed by comparing deaths attributed to cancer by VA with records in Vital Statistics Department and Chennai Cancer Registry.

Results

The VA reduced the proportion of deaths attributed to unspecified medical causes and unknown causes from 37% to 7% in early adult life and middle age (25–69 yrs) and has yielded fewer unspecified causes (only 10%) than the death certificate. The sensitivity of VA to identify cancer was 94% in the age group 25–69.

Conclusion

VA is practicable for deaths in early adult life or middle age and is of more limited value in old age. A systematic program of VA of a representative sample of deaths could assign broad causes not only to deaths in childhood (as has previously been established) but also to deaths in early adult life and middle age.     

Indomethacin-induced mitochondrial dysfunction and oxidative stress in villus enterocytes

Nonsteroidal anti-inflammatory drugs (NSAIDs) are known to cause small intestinal damage but the pathogenesis of this toxicity is not well established. Intestinal epithelial cells are thought to be affected by these drugs in the course of their absorption. These cells are of different types, viz. villus, middle and crypt cells. There is little information on which of these cells, if any, are particularly vulnerable to the effects of NSAIDs. This paper aimed to study the effects of indomethacin, an NSAID commonly used in toxicity studies, on different populations of enterocytes. Effects of the drug were assessed in terms of oxidative damage, mitotic activity, mitochondrial function and lipid composition in enterocytes isolated from the small intestine of rats that had been orally administered indomethacin. In addition, the effects of arginine and zinc in protecting against such changes were assessed. Cell viability, tetrazolium dye (MTT) reduction and oxygen uptake were significantly reduced in villus tip cells from rats dosed with the drug. Thymidine uptake was higher in the crypt cell fraction from these rats. Similarly, products of lipid peroxidation were elevated in the villus tip cells with a corresponding decrease in the level of the anti-oxidant, alpha-tocopherol. In isolated mitochondrial preparations from various enterocyte fractions, significant functional impairment and altered lipid composition were seen mainly in mitochondria from villus cells. Arginine and zinc pre-treatment were found to protect against these effects. These results suggest for the first time that the villus tip cells are more vulnerable to the damaging effects of indomethacin and that oxidative stress is possibly involved in this damage.     

Heat preconditioning prevents enterocyte mitochondrial damage induced by surgical manipulation

BACKGROUND: The small intestine is susceptible to free radical-induced damage and our earlier work has shown that surgical manipulation of the intestine results in generation of oxygen free radicals, leading to mucosal damage. Heat preconditioning has been shown to offer protection against various stresses including oxidative stress and this study looked at the effect of heat preconditioning on surgical manipulation-induced intestinal mitochondrial alterations. METHODS: Control and rats pretreated with heat were subjected to surgical manipulation by opening the abdominal wall and handling the intestine as done during laparotomy. Mitochondria were prepared from isolated enterocytes and structural and functional alterations were assessed. RESULTS: Surgical manipulation of the intestine resulted in mitochondrial alterations as seen by ultrastructural changes and altered lipid composition. Mitochondria were functionally impaired as evidenced by altered calcium flux, decreased respiratory control ratio, and increased tetrazolium dye reduction and swelling. Along with this, biochemical alterations such as increased lipid and protein oxidation were seen following surgical manipulation. Mild heat preconditioning of the animal prevented these damaging effects. CONCLUSIONS: These studies suggest that stress in the small intestine due to surgery can affect enterocyte mitochondrial structure and function and these effects can be prevented by mild whole body hyperthermia prior to surgery.     

Surgical manipulation of the small intestine and its effect on the lung

BACKGROUND: Surgical manipulation of the intestine results in generation of oxygen free radicals leading to mucosal damage as evidenced by ultrastructural and biochemical changes. It is likely that the gut-derived mediators can bring about damage to distant organs such as the lung. METHODS: Surgical manipulation of the gut was performed by opening the abdominal wall and handling the intestine. Lung damage was assessed by histology, markers of oxidative stress, and protein content in bronchoalveolar lavage fluid. Protection offered by pretreatment with various compounds such as allopurinol, L-arginine, quinacrine, and indomethacin was also studied. RESULTS: Gut manipulation resulted in neutrophil infiltration, oxidative stress, and permeability changes in the lung and these changes were maximum 30 and 60 min following surgical manipulation, which recovered with time and reversed to normal by 24 h. Prior treatment with inhibitors of xanthine oxidase, phospholipase A(2), or cyclooxygenase showed a protective effect against lung damage. CONCLUSION: This study has shown that laparotomy and intestinal handling result in distant organ (lung) damage which is probably brought about by neutrophil infiltration and oxidative stress on the lung. This is likely mediated by compounds generated in the intestine and transported into the systemic circulation since inhibition of generation of chemical mediators in the intestine offers protection against lung damage.