Dengue maculopathy: a case report

INTRODUCTION

Dengue fever is endemic in many countries of South East Asia. In spite of the occasional epidemics, dengue maculopathy remains a rare entity.

CASE HISTORY

A 31-year-old gentleman was admitted with a 6-day history of fever, generalised rash, headache and myalgia after a trip to Malaysia. There were no bleeding manifestations. The lowest platelet count was 71 x 10,000/ml, the haematocrit was 42.7%, and dengue serology was positive. On the 8th day of illness, he complained of bilateral blurred vision. Detailed visual examination showed visual acuity of right eye 6/30 and left eye 6/50. Fundoscopy revealed dilated veins, hyperaemic optic discs, flame and blot haemorrhages, soft exudates and macular ischaemia. After a course of high-dose steroids, the visual acuity as well as colour vision improved markedly.

DISCUSSION

The pathology of maculopathy is not obvious in this case, but an immunological reaction is suspected. There is a risk of residual visual impairment, and there is no definitive treatment. The use of high-dose steroids seemed to improve visual acuity and colour vision. However, it is not known whether immunosuppression improves the prognosis. Time for resolution is from 8 weeks to 4 months. Since there is an increase in the incidence of dengue fever in our region, coupled with rising international travel, one could postulate that global incidence of dengue-related maculopathy may become significant.

CONCLUSION

Ocular complications associated with dengue fever are rare but may result in permanent visual impairment. Dengue fever should be suspected in travellers, particularly those returning from endemic areas, and they should be systematically screened for maculopathy when visual disturbances arise.

Plasmid-electroporated primary hepatocytes acquire quasi-physiological secretion of human insulin and restore euglycemia in diabetic mice

We describe the durable correction of streptozotocin-induced murine diabetes by in vivo implantation of primary mouse hepatocytes electroporated ex vivo with a human proinsulin cDNA plasmid construct controlled by glucose and zinc regulatory elements. Transfected hepatocytes increased insulin transgene transcription and secretion within 10-20 min of exposure to 25 mM glucose or 60 microM zinc. Insulin release did not occur from secretory granules. Electroporated Rosa26 hepatocytes ( approximately 8 x 10(5) viable cells) were implanted in C57BL/6J diabetic mice in one of three sites: unresected liver, regenerating liver or mesentery. Control diabetic mice were implanted with untransfected hepatocytes. At 30 days after implantation, 8/15 control mice were alive, while 19/19 treated mice were alive. The ratio of body weight on day 30/nadir body weight was significantly higher for all treated groups compared with controls. All eight surviving control mice were hyperglycemic 30 days post-implantation, while 16/19 treated diabetic mice remained normoglycemic. Treated mice had lower mean glucose values (P< or =0.001) without fasting hypoglycemia and better glucose tolerance (P< or =0.0003) than untreated controls. All (6/6) diabetic mice implanted in regenerating liver and 71% (5/7) implanted in unresected liver were alive 77 days after implantation. Engrafted hepatocytes were identified, mainly around central veins, by staining for beta-galactosidase activity and with anti-human insulin antibody.

Evaluation of live renal donors with three-dimensional contrast-enhanced magnetic resonance angiography in comparison to catheter angiography

BACKGROUND

Catheter angiography is traditionally used to determine renal arterial anatomy in live renal donors. Three-dimensional (3D) contrast-enhanced magnetic resonance imaging (MRA) has been suggested as a noninvasive replacement. We assessed the possibility of using MRA in live renal donors in Malaysia.

METHODS

Twenty-six consecutive live renal donors were recruited from 2000 to 2002. All potential donors underwent evaluation of the renal arteries using both techniques. Angiographic findings from both modalities were subsequently compared with surgical findings at the time of donor nephrectomy. The total number and diameter of the arteries and the presence of early branching and renal abnormalities were noted.

RESULTS

Both angiographic modalities were able to detect multiple renal arteries with catheter angiography having a sensitivity of 100% and MRA a sensitivity of 97%. MRA missed one 1-mm artery due to a low index of suspicion. Renal artery caliber measurements were not significantly different between the two methods. However, both techniques tended to overestimate the caliber of the renal arteries when compared with measurements taken at surgery. Early branching was found in two arteries at the time of surgery, but only one was detected by both techniques. Renal cysts seen on MR were not detected by catheter angiography.

CONCLUSIONS

Our findings suggest that noninvasive MRA is a promising substitute for catheter angiography to evaluate the renal arteries of live donors.

Comparison of oxidative damage in Malaysian end-stage renal disease patients with or without non-insulin-dependent diabetes mellitus

BACKGROUND

Comparisons of oxidative indices and total antioxidant status between end-stage renal disease (ESRD) patients with or without diabetes is scant, especially in the Asian population.

METHOD

The assays were carried out according to known established protocols.

RESULT

The present study showed that ESRD patients with or without non-insulin-dependent diabetes mellitus (NIDDM) did not have any significant differences in antioxidant enzyme activities, advanced glycated end products (AGE), advanced oxidized protein products (AOPP) and ferric reducing ability of plasma (FRAP), indicating that hyperglycemia does not exacerbate oxidative damage in ESRD. The regulation of catalase and glutathione peroxidase is also altered in ESRD. Elevated FRAP was observed in both ESRD groups (with and without NIDDM). The dialysis process did not alter the antioxidant enzyme activities but decreased AGEs and FRAP and increased AOPP levels.

CONCLUSION

Oxidative stress is present in ESRD but this is not significantly exacerbated by hyperglycemia. The contribution of components in the pathology of renal failure towards oxidative stress exceeds that of hyperglycemia.

QF-PCR-based prenatal detection of aneuploidy in a southeast Asian population

OBJECTIVES

We have investigated the efficacy of using quantitative fluorescent polymerase chain reaction (QF-PCR) for the prenatal recognition of aneuploidy in chromosomes 13, 18, 21, X and Y. A total of 1115 samples, from mainly southeast Asian patients, were analysed and compared in a blind trial to the results previously obtained cytogenetically.

METHODS

A multiplex PCR involving 15 short tandem repeat (STR) sequences was used. The probability of two or more of these markers being informative was calculated, and this required the multiplex PCR to be modified.

RESULTS

The QF-PCR and previous cytogenetic results concurred, except for two products of conception (POC). One of these may be a case of complete uniparental disomy that was not recognized cytogenetically. The other was tetraploid, and as such appeared normal using QF-PCR. A mosaic trisomy 18 was correctly identified. The population sample was of a mainly Chinese, ethnic origin, and the allele frequency, size and heterozygosity appeared more restricted than the population groups analysed hitherto.

CONCLUSION

The QF-PCR methodology is an efficient cost-effective method of screening for major chromosome aneuploidy, and, for certain referral categories, could be used alone. It also appears to be applicable to patients of different ethnic origins.