The Effect of Postnatal Dexamethasone Treatment on Hypoxic-Ischemic Brain Injury in Neonatal Rats

PURPOSE: Dexamethasone is frequently administered to prevent or treat chronic lung disease in human neonates who are also prone to hypoxic-ischemic(HI) insults. Recently, meta-analysis of the follow-up studies reveals a significantly increased odd ratio for the occurrence of cerebral palsy or an abnormal neurologic outcome, and there is conflicting evidence regarding the impact of dexamethasone exposure on HI brain injury. This study was conducted to explore the effect of post-HI dexamethasone administration on neuronal injury in neonatal rats. METHODS: HI was produced in seven-day-old rats by right carotid artery ligation followed by two hours of 8% oxygen exposure. At the end of HI, the animals were injected intraperitoneally either with dexamethasone(0.5 mg/kg) or saline. Neuronal injury was assessed seven days after the HI by the area of infarction, TUNEL reactivity, Bcl-2 and Bax expression in brain. RESULTS: Post-insult dexamethasone administration resulted in reduction of weight gain and a higher mortality rate during seven days after HI. Dexamethasone treatment revealed no effect on the size of brain infarction induced by HI. Bax protein expression increased in dexamethasone treated brain but Bcl-2 protein expression and TUNEL reactivity revealed no significant differences between dexamethasone treated and non treated brain. Increased Bax protein expression suggest upregulation of the apoptosis by dexamethasone. CONCLUSION: The result suggests the adverse role of Post-HI administration of dexamethasone in neonatal HI.

Urinary Tract Infection and Vesicoureteral Reflux in Children

Fine needle aspiration biopsy cytology (FNA) for diagnosis of a variety of breast tum- ors has been proven to be a simple, safe, and cost saving diagnostic methodology with high accuracy. Cytologic specimens from 1,029 fine needle aspirations of the breast during last 3-year period were reviewed and subsequent biopsies from 107 breast lesions were reevaluated for cytohistological correlation. FNA had a sensitivity of 81.6% and a specificity of 98.3%. One out of 107 cases bio- psied revealed a false positive result (0.9%) and the case was due to misinterpretation of apocrine metaplastic cells in necrotic backgound as malignant cells. A false negative rate was 8.4% (9 of 107 cases biopsied). Six of 9 false negative cases were resulted from insufficient aspirates for diagnosis, and remaining three of 9 false negative cases revealed extensive necrosis with no or scanty viable cells on smears. The results indicate that for reducing false positive and false negative rates of FNA, an experienced cytopathologist and a proficient aspirator are of great importance.

Clinical Significance of Simple Ventricular Septal Defect

PURPOSE: To investigate the clinical significance and frequency of simple VSD by location of the defect and hemodynamic severity. METHODS: We studied 482 cases who were diagnosed as simple VSD at department of Pediatrics, Kyung Pook University Hospital between December 1983 and July 1993. All cases were diagnosed by 2 dimensional echocardiography and cardiac catheterization was done in 256 cases. RESULTS: Overall VSD location was distributed as followings: Membranous 358(74.3%), subarterial 84(17.4%), muscular 33(6.8%) and malalignment 7(1.5%). According to the hemodynamic classification of Kidd and Keith, we categorized 256 cases who were undergone cardiac catheterization: Group I was 203 cases(79.3%), being membranous 145(71%), subarterial 50(25%) and muscular 8(4%), group II 17 cases(6.6%), being membranous 12(71%) and subarterial 5(29%), group III 12 cases(4.7%), being membranous 11(91%) and malalignment 1(8%), group IV 11 cases(4.3%), being membranous 5(45.4%), subarterial 3(27.3%) and malalignment 3(27.3%), group V 10 cases (3.9%), being membranous 7, subarterial 2 and muscular 1, and group VI 3 cases(1.2%), being subarterial 2 and malalignment 1. In 21 cases(4.4%), aortic valvular prolapses were developed, being subarterial 16 (76.2%), membranous 4(19%) and muscular 1(4.7%). In 6 cases categorized as group I, aortic regurgitation were developed, being membranous 4, subarterial 1 and muscular 1. There were 5 operative death, whom all were belong to group III or above. CONCLUSIONS: The location of VSDs was distributed as followings: Membranous 73.4%, subarterial 17.4%, muscular 6.8% and malalignment 1.5%. And subarterial and malalignment VSD were more frequently accompanied with poor prognostic result in terms of hemodynamic severity.