异常黑胆质成熟剂黄酮类化合物诱导HepG2细胞凋亡机制的研究

目的：观察异常黑胆质成熟剂中黄酮类化合物对人肝癌细胞株(HepG2)体外生长、凋亡及相关基因表达的调控作用,探讨异常黑胆质成熟剂黄酮类化合物诱导癌细胞凋亡及抗癌活性的物质基础及其作用机制。方法：采用四氮甲基唑蓝法(MTT)、琼脂糖凝胶电泳技术、流式细胞术及逆转录-多聚酶链式反应技术(RT-PCR)等,观察异常黑胆质成熟剂黄酮类化合物对HepG2生长、凋亡及凋亡基因调控的影响。结果：异常黑胆质成熟剂黄酮类化合物明显抑制HepG2细胞体外生长,HepG2细胞在sub-G₁期受到阻滞,并能诱导细胞发生凋亡,明显下调Bcl-2 mRNA表达水平,同时可上调p53,p21,Bax基因mRNA表达水平。结论：异常黑胆质成熟剂黄酮类化合物对癌细胞体外生长、凋亡及凋亡基因表达具有明显的调控作用。黄酮类化合物可能是异常黑胆质成熟剂发挥抗癌作用的主要活性成分,而抑制细胞生长、诱导细胞凋亡及调控凋亡基因表达等可能是其发挥抗癌活性的重要途径。     

止泻散敷脐治疗婴幼儿腹泻100例

0　引言　腹泻乃小儿最常见病 ,尤以 2岁以下婴幼儿最为常见 .年龄越小 ,发病率越高 ,且多在夏、秋季发病 .小儿患病后惧怕打针 ,服药以及输液 ,给治疗带来一些困难 . 12 a来 ,我们用自拟的止泻散敷脐治疗婴幼儿泄泻 ,效果良好 .1　对象和方法1.1　对象　 1998- 0 6 / 1999- 10婴幼儿腹泻发病高峰期门诊病例 10 0 (男 6 6 ,女 34 )例 ,年龄 2月龄～ 5岁 .肠炎 5 8例 ,单纯消化不良 42例 . 6 7例曾多次治疗 ,33例初诊 .凡接受治疗之患儿 ,一律停止用其他药物 .1.2　方法　药物组成 :川椒 12 g,干姜 12 g,小茴香 12 g,白芷 2 0 g,吴茱萸 5 g,…     

Synthesized MR images: comparison with acquired images

Synthesized and directly acquired spin-echo images were compared in order to assess the validity of magnetic resonance (MR) image synthesis as a method enabling retrospective formation of images by interactive manipulation of scan parameters. Synthetic images subjectively compared favorably in both accuracy and precision with acquired images when formed for the same values of echo (TE) and repetition times (TR) and for interpolated and extrapolated values of both TE and TR. Plots of synthetic and acquired signals within the same pixel sectors quantitatively showed comparable values for several regions of interest in the brain. Percent error and noise-normalized differences between acquired and synthetic images were tested as a quantitative measure of accuracy. Percent error was consistently less than 5% for brain parenchyma, and synthetic signals were accurate to within four times the noise level at acquisition. The apparent signal-to-noise ratio of synthetic images was comparable, superior, or inferior to similar acquired images, depending on the values of TE and TR. Total acquisition time required for synthetic formation of images for arbitrary values of TE and TR was equivalent to that of a single direct acquisition with a TR of 2,500 msec.     

Excretory urography with iohexol: evaluation in children

A multicenter clinical study was conducted using iohexol, a second-generation nonionic contrast medium, for excretory urography performed in 130 children. Doses of iohexol (300 mg iodine/ml) ranged between 150 and 660 mgI/kg (0.5 and 2.2 ml/kg). Iohexol was tolerated well, and no significant adverse reactions occurred. Sixty-five iohexol urograms were evaluated to determine the minimum dose for adequate visualization of the kidneys and collecting systems. A dose greater than 300 mgI/kg (1.0 ml/kg) always resulted in a urogram of diagnostic quality, while visualization was insufficient for diagnosis in 10% of studies done with doses of 150-300 mgI/kg (0.5-1.0 ml/kg). Another 65 iohexol urograms were compared in a blinded manner with a similar number of studies performed using iothalamate meglumine at comparable iodine concentration and dose. Visualization of calyces and pelvoinfundibular structures achieved with iohexol was rated better with statistical significance, but there was no difference in visualization of the renal parenchyma or ureters. Use of iohexol in excretory urography may be advantageous in children who are at greatest risk for an adverse reaction to contrast media or in those most likely to benefit from use of a low osmolality contrast agent.     

Regional blood flow to the canine vocal fold at rest and during phonation

Recent reports have suggested that blood flow to the vocal fold decreases during phonation. However, these studies relied on indirect measures of blood flow, such as tissue oxygen tension. Among the differing methods of measuring blood flow, one of the most sensitive is the microsphere surface technique. This technique has been effective in assessing the overall and regional blood flow to a number of different organs, including the cochlea. Employing an in vivo canine model, we injected microspheres into the left atrium. From there, they were distributed and became entrapped in the tissues in proportion to blood flow. We measured the blood flow to the entire vocal fold, as well as the lamina propria and muscularis layers. The results revealed a statistically significant (p less than .002) increase in blood flow on phonation. The increase, however, was due to increased flow to the muscularis layer. The flow to the lamina propria remained unchanged during phonation.     

Streptococcus pneumoniae associated with second-trimester chorioamnionitis. A case report

Streptococcus pneumoniae is found rarely in the normal vaginal flora but appeared to be the cause of chorioamnionitis and premature rupture of the membranes in a 16-week gestation. Both S pneumoniae and Ureaplasma urealyticum were recovered from cervical specimens, but only the Streptococcus grew from samples taken between the placental amnion and chorion.     

Research priorities in spasmodic dysphonia

OBJECTIVE: To identify research priorities to increase understanding of the pathogenesis, diagnosis, and improved treatment of spasmodic dysphonia. STUDY DESIGN AND SETTING: A multidisciplinary working group was formed that included both scientists and clinicians from multiple disciplines (otolaryngology, neurology, speech pathology, genetics, and neuroscience) to review currently available information on spasmodic dysphonia and to identify research priorities. RESULTS: Operational definitions for spasmodic dysphonia at different levels of certainty were recommended for diagnosis and recommendations made for a multicenter multidisciplinary validation study. CONCLUSIONS: The highest priority is to characterize the disorder and identify risk factors that may contribute to its onset. Future research should compare and contrast spasmodic dysphonia with other forms of focal dystonia. Development of animal models is recommended to explore hypotheses related to pathogenesis. Improved understanding of the pathophysiology of spasmodic dysphonia should provide the basis for developing new treatment options and exploratory clinical trials. SIGNIFICANCE: This document should foster future research to improve the care of patients with this chronic debilitating voice and speech disorder by otolaryngology, neurology, and speech pathology.     

Laryngeal modeling: Theoretical,in vitro,in vivo

Because the larynx is situated anatomically in an area which is difficult to measure and visualize, theoretical, in vitro, and in vivo models are used in laryngeal research. Vocal fold vibration was studied in anesthetized dogs, while electrically stimulating independently the superior and recurrent laryngeal nerves under conditions of constant airflow. Photoglottographic (PGG), electroglottographic (EGG), and subglottic pressure signals were obtained while stroboscopically photographing the larynx. Specific points along PGG, EGG, and subglottic pressure waveforms were correlated with laryngeal events which occurred during vibration. The canine larynx, in an experimentally produced phonatory mode, vibrates in a two mass (upper and lower margin) system and appears comparable to modal human voice production. The recorded glottogrophic waveforms from experimentally produced phonation in the canine are similar to signals recorded from humans. However, observed differences can be related to anatomic differences.