Stevens-Johnson syndrome and toxic epidermal necrolysis in Hong Kong.

INTRODUCTION: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) [hereafter, SJS/TEN] are uncommon but severe mucocutaneous reactions. Although they have been described in many populations worldwide, data from Hong Kong are limited. Here, we explored the epidemiology, disease characteristics, aetiology, morbidity, and mortality of SJS/TEN in Hong Kong. METHODS: This retrospective cohort study included all hospitalised patients who had been diagnosed with SJS/TEN in Prince of Wales Hospital from 1 January 2004 to 31 December 2020. RESULTS: There were 125 cases of SJS/TEN during the 17-year study period. The annual incidence was 5.07 cases per million. The mean age at onset was 51.4 years. The mean maximal body surface area of epidermal detachment was 23%. Overall, patients in 32% of cases required burns unit or intensive care unit admission. Half of the cases involved concomitant sepsis, and 23.2% of cases resulted in multiorgan failure or disseminated intravascular coagulation. The mean length of stay was 23.9 days. The cause of SJS/TEN was attributed to a drug in 91.9% of cases, including 84.2% that involved anticonvulsants, allopurinol, antibiotics, or analgesics. In most cases, patients received treatment comprising either best supportive care alone (35.2%) or combined with intravenous immunoglobulin (43.2%). The in-hospital mortality rate was 21.6%. Major causes of death were multiorgan failure and/or fulminant sepsis (81.5%). CONCLUSION: This study showed that SJS/TEN are uncommon in Hong Kong but can cause substantial morbidity and mortality. Early recognition, prompt withdrawal of offending agents, and multidisciplinary supportive management are essential for improving clinical outcomes.

Analysis of DNA fragmentation of in vitro cultured bovine blastocysts using TUNEL.

Programmed cell death (apoptosis) characteristically affects the single cells of blastocysts whereas necrosis affects cluster of cells in both the inner cell mass (ICM) and the trophectoderm (TE). This study uses the trophectodermrminal deoxynucleotidyl transferase (TdT) mediated dUTP nick-end labeling (TUNEL) assay as a way of evaluating the proportion of apoptotic cells and, thus, bovine blastocyst quality during in vitro culture at Days 6,7, and 8. Furthermore, parthenogenetic blastocysts were compared to in vitro fertilized blastocysts at Day 7. Confocal microscopy was used to generate three-dimensional reconstructions of the blastocysts. Apoptosis was observed in both early (Day 6) and late (Day 8) developing blastocysts. The dead cell index (DCI, total number of apoptotic nuclei/total number of nuclei) tend to increase as the in vitro culture time increases, and apoptosis is proportionately higher in the ICM than in the TE. The ratio of ICM to TE cells remains relatively constant even as the blastocysts cell number increases (Day 6 = 11.9 +/- 2.2, Day 7 = 11.2 +/- 0.5, Day 8 = 11.7 +/- 0.4). The overall cell number is significantly reduced in parthenogenetic blastocysts compared to Day 7 in vitro produced blastocysts (P = 0.037). The parthenogenetic blastocysts also show an increase of apoptosis over Day 7 controls. The decrease in cell number in the parthenogenetic blastocysts may be due to the increase of apoptotic nuclei observed. Based on these results we found the TUNEL assay to be a useful method for evaluating in vitro culture conditions of pre-implantation bovine embryos.