EXTRAPONTINE MYELINOLYSIS AFTER CORRECTION OF CHRONIC HYPONATRAEMIA WITH ISOTONIC SALINE

SUMMARY Rapid correction of severe chronic hyponatraemia with hypertonic saline can cause central pontine myelinolysis. Less well appreciated are the dangers of rapid correction with isotonic saline. A case is reported in which correction of severe hyponatraemia by 11 mmol/l in 24 hours with isotonic saline produced extensive extrapontine myelinolysis, one of the manifestations of the osmotic demyelination syndrome.     

Oral lesions of HIV and AIDS in Asia: An overview

The magnitude of HIV infection in the Asian region is increasing dramatically. Oral disease represents an important health problem for HIV-infected individuals, because of its diagnostic, prognostic and therapeutic implications. The documentation and reporting of HIV infection and AIDS in most of the Asian countries has been superficial. Though the epidemiology of HIV infection in Asia has been studied by many investigators, few attempts have been made to summarise the data and assess the magnitude of the problem, the mode of transmission, the spread of infection and clinical pattern of illness. A review of the literature shows that there is hardly any published data on oral manifestations of HIV infection or AIDS from the Asian region. However, some preliminary information is available on the type of lesion presenting in patients from India and Thailand. These observations suggest that oral manifestations are common in HIV-infected and AIDS patients. The pattern of occurrence of various lesions reported appears to show variation from those reports from other parts of the world, but no definitive conclusion can be drawn from these preliminary observations. Further epidemiological studies are necessary to substantiate the present understanding of the nature of oral lesions found in Asian countries.     

Early onset of diabetic nephropathy

A 12 year old Asian girl with a four year history of poorly controlled insulin dependent diabetes mellitus developed overt diabetic nephropathy. There were no clinical features of Rabson-Mendenhall syndrome. Screening for microalbuminuria would have identified incipient diabetic nephropathy and highlighted the importance of good glycaemic control. Although screening for microalbuminuria is recommended after five years from diagnosis, it may be appropriate to undertake this annually in those with poor glycaemic control.     

Small bowel disease in children: diagnosis with CT

The computed tomographic (CT) scans of 22 children with small bowel disease and those of 110 children with no small bowel disease were analyzed by two observers who were blinded with respect to clinical history and final diagnoses in order to determine which CT findings reliably indicated neoplastic, inflammatory, or noninflammatory processes. Bowel-wall thickening was the most reliable sign of disease. Five of six patients (83%) with bowel-wall thickness greater than 1 cm had neoplastic disease. Nine of ten patients (90%) with bowel-wall thickness between 3 mm and 1 cm had inflammatory disease, while four of six patients (66%) with wall thickness less than 1 cm and increased attenuation of mesenteric fat or an increase in the number of mesenteric vessels had noninflammatory edema. The presence of mesenteric masses was not a helpful sign for differentiating various disease processes. The results of this retrospective study suggest that the identification and classification of small bowel disease in children is possible from the objective analysis of CT findings.     

Uracil misincorporation in human DNA detected using single cell gel electrophoresis

Poor folate status may be important in the aetiology of several epithelial cell malignancies including cancer of the uterine cervix. Folic acid is essential in the synthesis of purine nucleotides and the pyrimidine nucleoside thymidine and it is probable that imbalances in these DNA precursors negatively effect DNA stability and may ultimately lead to malignant transformation. The development of a modified 'comet assay' using the bacterial DNA repair enzyme uracil DNA glycosylase, to detect misincorporated uracil in human DNA is reported here. The effect of perturbing folic acid and deoxyuridine levels on uracil misincorporation in normal human lymphocytes and cultured human tumour cells was investigated using this assay. HeLa cells and peripheral human lymphocytes incubated as agarose-embedded nucleoids, with 1 unit of uracil DNA glycosylase per microg of DNA, contained low levels of uracil in their DNA. Both HeLa cells and stimulated human lymphocytes cultured in folate-deficient medium were growth arrested. Incubating human lymphocytes in folate-deficient medium significantly increased the level of uracil detected compared with control cells. HeLa cells showed an increase in non-specific DNA damage (strand breaks). Deoxyuridine (100 microM) significantly increased the level of uracil detected in the DNA of both folate-deficient and control HeLa cells. It appears that this modified comet assay specifically detects misincorporated uracil in single human cells. It should, therefore, prove valuable in determining the role of folic acid status in DNA instability and cancer.