Abscesses in Crohn disease: percutaneous drainage

Fifteen patients with Crohn disease underwent percutaneous catheter drainage of related abdominal abscesses. The abscesses were located in the right lower quadrant (five patients); in the quadratus lumborum and/or iliopsoas muscles (four patients); in the left paracolic gutter (two patients); and in the right gluteal muscles, the liver, the left subphrenic space, and the pelvis (one patient each). All abscesses were evacuated successfully (n = 15 of 15), and no patient required surgery for abscess drainage. Existing fistulas closed in four of seven patients; the other three patients underwent surgery for excision of diseased bowel and enteric fistulas. No patient developed an enterocutaneous fistula as a result of catheter drainage. Percutaneous abscess drainage is effective for abscesses related to Crohn disease and should be regarded as the procedure of choice. An operation for the abscess can be avoided, and early results suggest that bowel surgery may be obviated in selected patients.     

Nutrient intakes, vitamin-mineral supplementation, and intelligence in British schoolchildren

Children (227), aged 7-12 years, weighed and recorded all food and drink consumed for seven consecutive days. Each child completed tests of verbal and non-verbal intelligence, and was then randomly allocated to one of two groups after matching for age, sex, IQ and height. In a double-blind trial lasting for 28 d, one group received a vitamin-mineral supplement daily and the other group a placebo. On re-testing, there were no significant differences in performance between the two groups. Furthermore, there was no consistent correlations between test scores and micronutrient intakes based on the weighed records. Thus, we found no evidence that learning ability in a cross-section of British schoolchildren was limited by the quality of their diets.     

Relationship between pulse-wave velocity and arterial elasticity

Pulse wave velocity (PWV) was measuredin situ in 11 isolated canine common carotid arteries. Seven arteries exhibited a linear PWV/pressure function at pressures ranging from 0 to 200 mm Hg. Four arteries yielded a linear relationship between PWV and pressure between 1 and 100 mm Hg; for these vessels the relationship was nonlinear at higher pressures. Seven arteries (five from the group which was linear up to 200 mm Hg and two from the group which was linear up to 100 mm Hg) were excised and presure/volume measurements were madein vivo. Using pressure/volume data, the Moens-Korteweg equation was evaluated as a predictor of the PWV/pressure relationship over the linear region. An expression was developed to anable prediction of the pressure/volume relationship using the coefficients at the linear PWV/pressure function; these predictions were evaluated. We found that, for this range, the Moens-Korteweg equation provides a very good basis for predicting the increase in PWV with increasing bias pressure. In addition, we found that the pressure/volume relationship of common carotid arteries is well represented by an exponential of the form V/V_o=Ke^αf(P), which was derived as the inverse solution to the Moens-Korteweg equation.     

Estimation of halothane in tissues by gas chromatography

Halothane was extracted from tissues by n-heptane and estimated by gas-chromatography using an electron capture detector unit. Variation in halothane concentrations between adjacent pieces of tissue was found. The 95% confidence limits of a single estimation was +/- 10.8% of the mean for liver and +/- 6.1% for the muscle in pigs. The corresponding figures in rats were +/- 9.5% and +/- 3.0%.     

Variant Alzheimer's disease with spastic paraparesis and cotton wool plaques is caused by PS-1 mutations that lead to exceptionally high amyloid-beta concentrations

We describe 3 new families affected by Alzheimer's disease with spastic paraparesis. In affected individuals, including the earliest known patient with this clinical syndrome, neuropathological examination revealed large "cotton wool" plaques similar to those we have previously described in a Finnish family. In the families in which DNA was available, presenilin-1 mutations were observed. Transfection of cells with these mutant genes caused exceptionally large increases in secreted Abeta42 levels. Furthermore, brain tissue from individuals with this syndrome had very high amyloid-beta concentrations. These findings define the molecular pathogenesis of an important subgroup of Alzheimer's disease and have implications for the pathogenesis of the disease in general.     

The Chronaxie and Propagation Velocity of Canine Cervical Vagus Nerve Fibers In Vivo

A recent medical development is the stimulation of the left afferent vagus nerve to control seizures in man. It is well known that vagus nerves innervate the heart; however, when afferent fibers are stimulated so are efferent fibers. Basic to the understanding of afferent fiber stimulation is the fundamental excitability properties of the vagus nerve. In this study, we measured chronaxie, rheobase and propagation velocity in the intact dog cervical afferent vagus nerve. Five adult mongrel dogs of both sexes, weighing 22–29 kg, were sedated with thiopental sodium, intubated, and connected to an anesthesia machine delivering isoflurane and oxygen. The ventral side of the neck was dissected and two bipolar electrodes were then placed on the vagus nerve, as far from one another as possible, and data were collected in the form of the strength–duration curve using single rectangular current pulses. Two different fiber types, which we designated A and B, were identified electrophysiologically. The average values for chronaxie were 75.4 ± 24.5 s for A fibers and 82.3 ± 23.3 s for B fibers. Values for rheobase were 0.63 ± 0.18 mA for A fibers and 0.66 ± 0.22 mA for B fibers. Propagation velocities were 59.0 ± 9.6 m/s for A fibers and 43.4 ± 8.0 m/s for B fibers. With an effective electrode area of 5 mm², this yields current densities of 13.0 mA/cm² and 12.9 mA/cm² for A and B fibers respectively. We also identified fibers in the right vagus, which we called B_H, with propagation velocity of 5.75 ± 0.35 m/s, which appears to be responsible for cardiac slowing. Fibers with a high propagation velocity appeared to have a short chronaxie and fibers with a low propagation velocity appeared to have a long chronaxie; however, no definitive relationship between propagation velocity and chronaxie was found.     

非普通肌球蛋白的功能

目的:综合分析非普通肌球蛋白的结构和功能。资料来源:应用计算机检索Pubmed1990-01/2005-02有关非普通肌球蛋白结构和功能的文献,检索词“Unconventional Myosins,Function,Review”,并限定文章语言种类为English。资料选择:对检索到的有关非普通肌球蛋白结构和功能方面的相关信息进行整理,选取针对性强的文章。同一领域的文献则选择权威杂志的文章。资料提炼:共检索到42篇相关文献,其中20篇文章符合要求。排除22篇,其中19篇系重复同一研究,3篇为Meta分析。资料综合:非普通肌球蛋白是具有与肌肉收缩过程中的肌球蛋白相同的保守马达区域系列,尾部不能形成纤维的肌球蛋白类。根据头部区域序列对比,肌球蛋白家族成员分成不同的类,到目前为止共分为18类(Ⅰ～ⅩⅧ)。目前已经明确非普通肌球蛋白在许多细胞过程中起不同的作用,包括粒子的输运、细胞形状的控制、细胞迁移、肌动蛋白细胞骨架组织形成、(细胞)内吞、胞外分泌和信号传导等。结论:非普通肌球蛋白的结构和功能已基本肯定,有些新的肌球蛋白细胞功能已经研究得很清楚,明确了非普通肌球蛋白在许多细胞过程中起不同的作用。但如何确定准确的分子马达和每个个体肌球蛋白的细胞功能仍是一个挑战,要达到这个目标,将要解决若干问题:①它们的机械化学特性是什么。②它们直接相互作用的伙伴是什么。③它们的特性是怎样调节的。