Visual pathways for object-oriented action and object recognition: functional anatomy with PET

The purpose of this study was to identify the functional anatomy of the mechanisms involved in visually guided prehension and in object recognition in humans. The cerebral blood flow of seven subjects was investigated by positron emission tomography. Three conditions were performed using the same set of stimuli. In the 'grasping' condition, subjects were instructed to accurately grasp the objects. In the 'matching' condition, subjects were requested to compare the shape of the presented object with that of the previous one. In the 'pointing' condition (control), subjects pointed towards the objects. The comparison between grasping and pointing showed a regional cerebral blood flow (rCBF) increase in the anterior part of the inferior parietal cortex and part of the posterior parietal cortex. The comparison between grasping and matching showed an rCBF increase in the cerebellum, the left frontal cortex around the central sulcus, the mesial frontal cortex and the left inferior parietal cortex. Finally, the comparison between matching and pointing showed an rCBF increase in the right temporal cortex and the right posterior parietal cortex. Thus object-oriented action and object recognition activate a common posterior parietal area, suggesting that some kind of within-object spatial analysis was processed by this area whatever the goal of the task.      

Rescue of implantation potential in embryos with poor prognosis by assisted zona hatching

The effect of the assisted zona hatching (AZH) procedure was investigated on 135 cycles with a poor prognosis of pregnancy due to: (i) maternal age > or = 38 years (45 cycles); (ii) three or more failed in-vitro fertilization (IVF) attempts (70 cycles), and (iii) patients possessing both inclusion criteria (20 cycles). The control groups (113 cycles) included patients possessing the same characteristics (42, 53 and 18 cycles respectively) and who did not undergo the AZH procedure. A total of 505 embryos was treated with AZH before transfer, resulting in: 14, 25 and 6 clinical pregnancies. The percentage of clinical pregnancies per cycle was significantly higher than controls for the first (31 vs 10% in control 1, P < 0.05) and second groups (36 vs 17% in control 2, P < 0.05). No significant difference in percentage of clinical pregnancies was found for the third group (30 vs 6%). Similarly, higher rates of implantation were obtained (11.5, 15 and 11%) compared to the respective controls (4%, P < 0.02; 6.3%, P < 0.01; and 1.5%). The rate of miscarriage in the AZH groups was similar to that obtained in the controls (22 vs 21%). Finally, the morphological analysis of the embryos transferred revealed that the poor prognosis condition is associated to a significantly slower rate of development and a higher rate of fragmentation. The present results indicate that AZH procedure improves pregnancy and implantation rates in patients with a poor prognosis of pregnancy by facilitating the hatching process in embryos which would otherwise be trapped inside the zona pellucida.      

Age at breast feeding start and postneonatal growth and survival

Colostrum has important anti-infective properties. It may also somehow promote the development of the child's immunological system. Discarding colostrum, as practised in some cultures, could thus have adverse health consequences beyond the neonatal period. To test this hypothesis, the age at breast feeding start of 734 healthy newborns in urban Guinea-Bissau was ascertained. The children were then prospectively followed up to 3 years of age. Eighty nine deaths occurred during the study. The probability of death in the age interval 28 days to 3 years was about 20%. The child's age at breast feeding start had no statistical impact on postneonatal growth or survival. As a single measure, early breast feeding start is not likely to make much difference for the long term growth or survival of children living under material poverty conditions.     

CYP2D6和GST在白种人晚期肾病中的遗传变异

目的生物转化酶细胞色素P4502D6(CYP2D6)和谷胱苷肽转移酶-M1(GST-M1)、谷胱苷肽转移酶-T1(GST-T1)共同代谢内源性和外源性毒素,一部分人群由于相应基因变异导致这些酶缺乏表达,我们检测白种人群中晚期肾病(ESRD)病人这些酶的基因多态性是否比健康者有较高的频率.方法从列克星顿及周围地区征募330名晚期肾病病人和303名健康者,均为白种人,给予他们进行CYP2D6和GST-M1和T1基因分型.结果在ESRD病人中CYP2D6和GST-M1和GST-T1以及CYP2D6和GST-M1或GST-T1都缺乏分别为2.1%和4.2%;而在健康者中均为0.3%(P<0.01).结论CYP2D6和GST-M1和/或GST-T1酶缺乏在ESRD病人中有较高的频率,提示这些酶缺乏可以预计慢性肾病进展的可能性.