Involvement of programmed cell death in preimplantation embryo demise

Fragmentation is frequently observed in animal and human embryosobtained via in-vitro fertilization (IVF), and is known to beassociated with decreased pregnancy rates and poor survivalfollowing cryopreservation. We postulate that embryo fragmentationis a consequence of activated programmed cell death (PCD) andsubsequent apoptosis and discuss evidence of morphological,histological and biochemical features compatible with the occurrenceof PCD in preimplantation embryos. If PCD is an underlying causeof the high incidence of the fragmentation seen in human pre-embryos,it remains to be determined whether this is reflective of thenatural incidence of lethal chromo somes in the human populationor due to the IVF procedure and culture conditions.     

1999年至2001年贫困县农村居民主要死因及潜在减寿年数调查

目的：调查贫困县农村居民主要的死亡原因及潜在减寿年数(potential years of life lost，PYLL)。方法：采用整群抽样的方法抽取河南省睢县后台乡、尚屯乡和城隍乡，对其3a来死亡居民的情况进行回顾性调查。运用全死因和PYLL分析方法对死亡资料进行分析。结果：引起当地居民寿命损失的主要疾病为恶性肿瘤、脑血管病、呼吸系病、心脏病及损伤和中毒。其中损伤和中毒占死因构成的9．99％，占总PYLL的22．77％，恶性肿瘤、脑血管病、心脏病和呼吸系病这几种主要的慢性病的死亡率累积构成为65．07％，PYLL累计构成为36．95％。结论：以恶性肿瘤为主的慢性非传染性疾病成为当前贫困地区疾病控制工作的重点，损伤与中毒成为重要的公共卫生问题。     

Continuous recording of middle cerebral artery blood velocity in clinical neurosurgery

Summary Intracranial pressure, arterial blood pressure, and middle cerebral artery blood velocity were monitored for periods from 1 to 10 days in 30 neurosurgical intensive care patients. The recordings revealed rapid changes in the cerebral perfusion and gave insight into individual cerebral haemodynamic states.Twenty patients consistently showed CO₂ reactivity within normal limits, between 2.5 and 5% per mm Hg (19–38% per kPa). Severely impaired CO₂ reactivity, considerably below 1% per mm Hg (7.5% per kPa) was observed in four patients. Three of these patients died, while the fourth patient survived in a persistent vegetative state.Seven patients demonstrated pressure-passive blood velocity changes throughout the observed CPP range. The four patients with severely impaired CO₂ reactivity all belonged to this group. The recordings from three of the remaining 23 patients showed signs of MCA blood velocity autoregulation with a lower regulatory limit of about 40–45 mm Hg. This observation is in keeping with findings from electromagnetic flowmetry on brain arteries in the neurosurgical operating field, and supports blood velocity measurements as a relevant index of brain perfusion in clinical neurosurgery and neuro-intensive care settings.     

"脑死亡法"与我国肝脏移植

目前我国是世界上尚未通过脑死亡法的少数国家之一。经过几十年的努力，我国肝脏移植已经取得了很大的成绩，但因为我国没有实行脑死亡法，供肝主要来源于心脏死亡的供体，造成供肝质量较差，导致我国肝脏移植后的疗效不如国际先进水平。实施脑死亡法必将大大促进我国肝脏移植水平的提高。     

Primary Prevention of Sudden Cardiac Death in Heart Failure: Will the Solution Be Shocking?

Sudden cardiac death (SCD) may occur in as many as 40% of all patients who suffer from heart failure. This review describes the scope of the problem, risk factors for SCD, the effect of medications used in heart failure on SCD and the potential effect of the implantable cardioverter-defibrillator in primary prevention.     

Spatial and temporal pattern of purkinje cell degeneration in shaker mutant rats with hereditary cerebellar ataxia

Temporal-spatial patterns of surviving Purkinje cells were studied quantitatively in a rat mutant (shaker) with differential hereditary cerebellar ataxia and Purkinje cell degeneration. Shaker rat mutants are characterized behaviorally as mild if they are ataxic or as strong if they have ataxia and tremor. Purkinje cells degenerate in both mild and strong shaker mutants, but the temporal and spatial patterns of cell death are strikingly different. In mild shaker mutants, Purkinje cell death is temporally restricted, with 31-46% of the Purkinje cells in lobules I-IX dying by 3 months of age. Very few Purkinje cells degenerate after this age. Purkinje cell death is spatially random. In lobules I-IX, every second, third, or fourth Purkinje cell degenerates. Purkinje cells in lobule X do not degenerate. In strong shaker mutants, Purkinje cell degeneration is temporally protracted and spatially restricted. By 3 months of age, most Purkinje cells in lobules I-VIa, -b, and -d, and -d have degenerated. Numerous Purkinje cells in the paravermis of lobules VIIb-VIII have also degenerated. Surviving Purkinje cells in the vermis and lateral hemisphere of lobules VIIb-VIII are aligned in parasagittally oriented stripes or transversely oriented bands. Purkinje cells continue to degenerate in localized areas of the posterior lobe such that, by 18 months of age, surviving Purkinje cells are limited primarily to lobules VIc, VIIa, IXd, and X. Quantitative analysis indicates that none of the Purkinje cells in these lobules degenerate.