PURPOSE: TGF-beta1 has been shown to rescue cultured neurons from excitotoxic and hypoxic cell death and to reduce infarct size after focal and global ischemia in rats and rabbits. The present study investigated the therapeutic effects of TGF-beta1 in hypoxic ischemic brain damage of neonatal rats. METHODS: Seven-day postnatal Sprague-Dawley rats underwent unilateral common carotid artery ligation and dissection followed thereafter by exposure to systemic hypoxia with 8% oxygen for 2 hours at 34 degrees C. In 19 rats, 0.05 microgram of TGF-beta1 was injected intracerebroventricularly just after hypoxia ischemia while the remaining 20 rats were injected with vehicle. Neuropathologic examination (Morphometric analyses of brain tissue specimens) were carried out at 30 days of postnatal age, and their brains were categorized as follow: 0=normal; 1=mild atrophy; 2=moderate atrophy; 3=atrophy with cystic cavitation <3 mm; 4=cystic cavitation >3 mm of the cerebral hemisphere ipsilateral to the carotid artery ligation. The width of the ipsilateral hemisphere also was determined on a posterior coronal section and compared with that of the contralateral hemisphere to ascertain the severity of cerebral atrophy/cavitation. RESULTS: Neuropathologic results showed that 1/19 (5.3%) rats treated with TGF-beta1 showed no brain damage compared with 2/20 (10%) controls. Mild and moderate brain damage occurred in 4 (21%) and 4 (21%) TGF-beta1 treated rats and 6 (30%) and 7 (35%) controls respectively. Cystic cavitation occurred in 10 (53%) TGF-beta1 treated rats and 5 (25%) controls. Interhemispheric diameter ratio in rats treated with TGF-beta1 is 0.66+/- 0.17 and 0.69+/-0.18 in controls. There was no statistically significant difference of brain damage and interhemispheric diameter ratio between TGF-beta1 treated and control rats. CONCLUSION: The results indicate that in neonatal rat model 0.05 microgram of TGF-beta1 treatment does not protect the hypoxic-ischemic brain damage.
Animals ; Anoxia ; Atrophy ; Brain* ; Carotid Arteries ; Carotid Artery, Common ; Cell Death ; Cerebrum ; Ischemia ; Ligation ; Models, Animal* ; Neurons ; Oxygen ; Rabbits ; Rats* ; Rats, Sprague-Dawley ; Transforming Growth Factor beta1 ; Transforming Growth Factors*

PURPOSE: Early detection and proper treatment of retinopathy of prematurity (ROP) is crucial. The postnatal age of 4-6 weeks has been considered the most optimal time to screen the high risk infants for ROP. However, ROP rarely appears even before this period of age and we experienced several cases ROP detected before 4 weeks of age at NICU of Kyungpook University Hospital. This study was conducted to evaluate the most optimal time of first ophthalmic examination for ROP screening. METHODS: A retrospective analysis of ROP screening records of 106 infants who admitted to the NICU of Kyungpook University Hospital from January 1996 to March 1999 was performed. Infants with a gestational age <34 weeks, birth weight <1,500 gm and perterm infants who exposed to supplemental oxygen were included in this study. ROP infants were grouped according to birth weight : Group I (birth weight > or =1,500 gm) and Group II (birth weight <1,500 gm). Ophthalmic examinations were commenced between 3 weeks and 6 weeks postnatal age and recorded using the International Classification of ROP. RESULTS: Out of 106 infants screened, 35 infants were found to have some degree of ROP in at least one eye on at least 1 occasion. Of 35 infants with ROP, 11 infants were screened before the postnatal age 4 weeks. Eight ROP, including one stage 3 ROP, were detected at this first ophthalmic examination. Review for the time of first detection of ROP by postconceptional age revealed that stage 3 ROP and threshold ROP did not develop before 34 weeks. Postnatally ROP developed and progressed earlier in Group I than in Group II. The time of onset and highest stage represented by postnatal age in Group I and II were 28+/-7 days, 57+/-19 days and 32+/-15 days, 69+/-26 days respectively. The time of onset and highest stage represented by postconceptional age in Group I and II were 35.4+/-2.3, 36.3+/-2.9 weeks and 36.0+/-1.6, 38.0+/-3.6 weeks respectively, revealed no significant difference between two groups. CONCLUSION: These data indicate that the time of onset and progression of ROP are correlated more closely with postconceptional age than with postnatal age. In other words, the postconceptional age is superior to postnatal age in determining when to initiate ROP examination. Our study suggests that screening infants at 34 weeks postconceptional age seems to reliable for early detection of severe ROP in larger, and more mature preterm infants.
Birth Weight ; Classification ; Gestational Age ; Gyeongsangbuk-do ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Mass Screening* ; Oxygen ; Retinopathy of Prematurity* ; Retrospective Studies