A tidal ventilation model for oxygenation in respiratory failure

We develop tidal-ventilation pulmonary gas-exchange equations that allow pulmonary shunt to have different values during expiration and inspiration, in accordance with lung collapse and recruitment during lung dysfunction (Am. J. Respir. Crit. Care Med. 158 (1998) 1636). Their solutions are tested against published animal data from intravascular oxygen tension and saturation sensors. These equations provide one explanation for (i) observed physiological phenomena, such as within-breath fluctuations in arterial oxygen saturation and blood-gas tension; and (ii) conventional (time averaged) blood-gas sample oxygen tensions. We suggest that tidal-ventilation models are needed to describe within-breath fluctuations in arterial oxygen saturation and blood-gas tension in acute respiratory distress syndrome (ARDS) subjects. Both the amplitude of these oxygen saturation and tension fluctuations, and the mean oxygen blood-gas values, are affected by physiological variables such as inspired oxygen concentration, lung volume, and the inspiratory:expiratory (I:E) ratio, as well as by changes in pulmonary shunt during the respiratory cycle.     

新生儿高间接胆红素血症患儿凝血象的研究及临床意义

目的　探讨凝血因子、血小板和新生儿高间接胆红素血症的关系 ;方法　用散射比浊法测定新生儿高间接胆红素血症患儿 6 0例和正常足月新生儿 2 0例的凝血酶原时间 (PT)、激活的部分凝血活酶时间 (APTT) ,同时检查血小板计数和肝功能 ;结果　新生儿高间接胆红素血症患儿的PT、APTT比正常足月新生儿组明显升高 ,有显著性差异 ,P值均 <0 .0 5 ,而血小板计数和肝功能两组间比较 ,无显著性差异 ,P值 >0 .0 5 ;结论　新生儿高间接胆红素血症患儿临床上常出现脐部渗血、穿刺部位出血不止等表现与新生儿血小板数量无关 ,而与PT、APTT延长有关 ,可能由于母乳喂养的推广和生后没有进行常规维生素K预防。因此 ,我们建议在治疗新生儿高胆红素血症的同时 ,要注意预防维生素K的缺乏。     

Familial partial trisomy 5p resulting from segregation of an insertional translocation

A case of duplication of segment p13-p15 of the short arm of chromosome 5 as the result of an insertional translocation in a mentally retarded girl with congenital anomalies is reported. Some of the apparently balanced carriers of the inverted insertion showed minor congenital anomalies.     

Single-equation models for the tear film in a blink cycle: realistic lid motion.

We consider model problems for the tear film over multiple blink cycles that utilize a single equation for the tear film; the single non-linear partial differential equation that governs the film thickness arises from lubrication theory. The two models that we consider arise from considering the absence of naturally occurring surfactant and the case when the surfactant is strongly affecting the surface tension. The film is considered on a time-varying domain length with specified film thickness and volume flux at each end; only one end of the domain is moving, which is analogous to the upper eyelid moving with each blink. Realistic lid motion from observed blinks is included in the model with end fluxes specified to more closely match the blink cycle than those previously reported. Numerical computations show quantitative agreement with in vivo tear film thickness measurements under partial blink conditions. A transition between periodic and non-periodic solutions has been estimated as a function of closure fraction and this may be a criterion for what is effectively a full blink according to fluid dynamics.     

The effects of levetiracetam on objective and subjective sleep parameters in healthy volunteers and patients with partial epilepsy

Levetiracetam is a novel antiepileptic drug which has recently been released as an adjunctive treatment for partial epilepsy. In the two studies reported here we examined the objective and subjective effects of levetiracetam on sleep in 12 healthy volunteers and 17 patients [16 who could be evaluated for electroencephalogram (EEG) recordings] with a history of partial epilepsy on stable carbamazepine monotherapy. The studies were of a similar double-blind crossover placebo-controlled design with subjects' sleep being recorded in their own homes. The results from the two studies showed considerable similarities. In both, levetiracetam produced an increase in the time spent in stage 2 sleep, which in the patient study was accompanied by a decrease in the time spent in stage 4 sleep and in the volunteer study an increase in rapid eye movement (REM) latency. The subjective changes included reports that sleep was of a better quality with fewer awakenings and patients also reported that their sleep was more restful. Volunteers and patients did, however, feel less alert on waking in the morning. Therefore, both groups reported a decrease in awakenings after levetiracetam despite the finding from the EEG of no change in the actual number of awakenings. It may be concluded from both studies that levetiracetam does affect some indicators of subjective sleep perception, but does not influence objective sleep measures of sleep continuity. The results from the patient study during placebo add-on treatment also showed that patients on carbamazepine had a marked increase in SWS, an increase in stage 2 sleep and an increase in REM latency compared with healthy volunteers. Interestingly, levetiracetam also reduced bilateral epileptiform EEG activity, particularly in patients with more discharges.     

基于椭圆方程的三维心脏超声图像的位移场估计

三维超声心动图技术能使医生直观地看到心脏整体和各部分的运动，在临床得到重视。在三维超声心动图技术中，如何定量的描述心脏中某个组织的运动状况极具临床意义。本研究提出了一种基于椭圆偏微分方程的二尖瓣三维运动估计方法。该方法直接在三维超声图像的位移场上进行了运动估计，避免了传统运动估计方法，如光流法，需要标定的缺点。本研究首先建立一个二次误差指标函数，然后利用变分法导出了三维空间下的一组椭圆型偏微分方程。这类方程有着比较成熟的数值解法，利用了有限差分法，对多个三维超声数据立方体进行了计算，结果证明这类方法是有效的。     

Interstitial deletion of band q12 of chromosome 5

A six-months-old girl is presented with psychomotor retardation and multiple congenital malformations. The karyotype done on peripheral blood lymphocytes and skin fibroblasts was found to be 46,XX del(5)(411q13). The parents are consanguineous. Their karyotypes were normal.
The genes for Arylsulphatase B and Hexosaminidase B are not located in band 5q12.     

Trisomy 6qter

A previously reported patient with trisomy for the distal part of 6q was shown by R-banding to be trisomic for 6q26qter, due to a t(6;22)(q26;p12) mat. Altogether nine patients with 6qter trisomy have been reported. The main features of the 6qter trisomy syndrome are: severe mental and growth retardation; acrocephaly and brachycephaly; a carp-shaped mouth; micrognathia; a very short neck with unusual anterior webbing; joint contractures; the absence of severe inner organ malformations; and survival into adulthood.     

Partial trisomy 3q syndrome inherited from familial t(3;9)(q26.1; p23)

A five-year-old girl was referred to prometaphase chromosome analysis because of mental retardation, facial dysmorphic features suggestive of Cornelia de Lange syndrome, cleft palate and additional minor congenital malformations of the cardiac system and fingers and toes. A familial balanced translocation (3;9)(q26.1; p23) was found. The karyotype of the proposita was 46,XX,der(9),t(3;9)(q26.1;p23). Thus the patient was trisomic for 3q26.1-qter and monosomic for 9p23-pter. The unbalanced chromosome constitution was not detected by standard Q-banding analysis shortly after birth. The karyotype was misdiagnosed as 46,XX,9(p+) in the proposita and her mother, and thought to be a normal variant of chromosome 9. The repeated cytogenetic study led to the diagnosis of the translocation and to the possibility of prenatal diagnosis in the translocation carriers. A survey of 22 published cases of dup(3q) showed that nearly 60% were secondary to familial balanced rearrangements with an excess of maternally derived abnormal chromosomes 3. Red blood cell galactose-1-phosphate-uridyltransferase (GALT) activity was normal in the patient, consistent with previous assignment of the gene locus for GALT to 9p13 (Shih et al. 1982).     

桡侧腕短伸肌腱部分移位修复第一腕掌关节脱位的应用解剖与手术设计

目的:为桡侧腕短伸肌腱部分移位修复第一腕掌关节脱位提供解剖学依据。方法:30侧成人上肢标本,将桡侧腕短伸肌腱分为上、中、下3部分,进行形态学测量。结果:桡侧腕短伸肌腱长度为(15.3±1.9)cm(10～22.5cm),其宽度:上段为(15.4±5.2)mm(5.3～23.8mm),中段(10.0±3.0)mm(4.2～18.5mm),下段(5.5±0.6)mm(3.7～9.6mm);厚度:上段为(0.6±0.3)mm(0.1～1.4mm),中段为(1.8±0.7)mm(0.7～3.0mm),下段为(2.1±1.2)mm(0.8～3.1mm)。结论:桡侧腕短伸肌腱部分转位有足够的长度以修复第一腕掌关节脱位。