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In human in-vitro fertilization (IVF)-embryo transfer, the in-vitro culture environment differs from in-vivo conditions in that the oxygen concentration is higher, and in such conditions the mouse embryos show a higher concentration of reactive oxygen species (ROS) in simple culture media. ROS are believed to cause damage to cell membranes and DNA fragmentation in somatic cells. This study was conducted to ascertain the level of H2O2 concentration within embryos and the morphological features of cell damage induced by H2O2. A total of 62 human oocytes and embryos (31 fragmented, 15 non-fragmented embryos, 16 unfertilized oocytes) was obtained from the IVF-embryo transfer programme. The relative intensity of H2O2 concentrations within embryos was measured using 2',7'-dichlorodihydrofluorescein diacetate by Quanti cell 500 fluorescence imaging and DNA fragmentation was observed with transmission electron microscopy and an in-situ apoptosis detection kit. The H2O2 concentrations were significantly higher in fragmented embryos (72.21 +/- 9.62, mean +/- SEM) compared to non-fragmented embryos (31.30 +/- 3.50, P < 0.05) and unfertilized oocytes (30.75 +/- 2.67, P < 0.05). Apoptosis was observed only in fragmented embryos, and was absent in non-fragmented embryos. Electron microscopic findings confirmed apoptotic bodies and cytoplasmic condensation in the fragmented blastomeres. We conclude that there is a direct relationship between increased H2O2 concentration and apoptosis, and that further studies should be undertaken to confirm these findings.   相似文献   
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Rademaker KJ, Groenendaal F, Jansen GH, Eken P, de Vries LS. Unilateral haemorrhagic parenchymal lesions in the preterm infant: shape, site and prognosis. Acta Pædiatr 1994;83:602–8. Stockholm. ISSN 0803–5253 In a prospective cranial ultrasound study of 544 infants with a gestational age of 32 weeks or less, 20 (3.6%) infants were diagnosed as having a unilateral parenchymal lesion (PL). Based on the shape of the PL and the evolution on ultrasound, the infants were divided into three groups: group I consisted of 11 infants, in whom the PL was triangular/fan-shaped and separate from the ventricle. The PL evolved into small cystic lesions; group II comprised 3 infants who had a PL with a similar shape, but partially communicating with the ventricle; group III consisted of 6 infants who had a globular-shaped lesion in communication with the ventricle. In groups II and III, the PL evolved into one porcncephalic cyst. The PL was considered to be due to venous infarction in all cases with intraventricular haemorrhage preceding the PL in 7 cases. Sixteen infants survived. A postmortem was performed in 2 of the 4 infants who died, confirming the diagnosis of venous infarction. Neurologicdl sequelae were present in only 2 cases in the first group, while all 6 survivors of the other two groups developed mild to severe hemiplegia. Long-term follow-up was not always available and 4 of the 18 survivors were still less than 18 months when last seen. In 9 of the 11 infants in group I, the PL was localized in the frontoparietal region, while in 8 of the 9 infants in group II or III, the PL was beyond the trigone in the occipital region. The outcome of the unilateral PL is not always unfavourable. It was evident that not only the shape of the lesion and whether or not there was communication with the lateral ventricle, but also the site of the lesion (whether or not it extended into the occipital periventricular white matter) appeared to be important with regard to neurodevelopmental outcome.  相似文献   
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OBJECTIVE: During pulmonary resections for non-small cell lung cancer, the pulmonary vein is traditionally interrupted first to prevent seeding of malignant cells and consequently decrease metastatic implantation. This hypothesis was never confirmed scientifically. The aim of the present study was to determine whether the sequence of vessel interruption during lobectomy (lobar vein or lobar artery first) affects disease recurrence. METHODS: A historical prospective study was performed of 279 consecutive patients with complete follow-up, who survived lobectomy for non-small cell lung cancer during 1992 to 1998, in a single center. Pre-, intra-, and postoperative variables were collected from the medical records; recurrence and vital status were obtained from follow-up files, central population registry, and personal confirmation, updated to December 2000. Comparison of recurrence rates by sequence of ligation and other independent variables was assessed by univariate and multivariate logistic regression analyses. RESULTS: A total of 133 patients (48%) had vein interruption before the artery (V-first) and 146 (52%) had artery interruption first (A-first). The distribution of demographic, clinical, and other characteristics was similar between the 2 groups, except for the operated side and performing surgeons. The morbidity, blood requirement, and length of stay were equal for both groups. The total recurrence rate (A-first, 53%; V-first, 51%) was similar. Multivariate analysis (controlling for the effect of the performing surgeon) revealed elevated risk for recurrence among patients with high disease stage (odds ratio = 2.54), male gender (odds ratio = 1.59), intraoperative lung manipulation (odds ratio = 2.72), and blood transfusion (odds ratio = 1.49). Sequence of vessel interruption was not found as a risk factor for recurrence (odds ratio = 1.29; 95% 0.73 to 2.29, P =.4). CONCLUSIONS: Our results did not show that sequence of vessel interruption during lobectomy plays a role in tumor recurrence. A prospective study with randomization in selection of method as well as surgeons for each patient is needed to confirm these results.  相似文献   
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