2-甲基-5-取代苯氧基伯氨喹的合成及其抗疟活性

为寻找高效低毒的间日疟根治药,合成了7个2-甲基-5-取代苯氧基伯氨喹Ⅱ_1～7,以与强效的4-甲基取代类似物比较,探索构效关系。初步生物评价结果表明,化合物Ⅱ_1～7对鼠疟Plasmodium berghei的抑制性治疗作用及对鼠疟P.yoelii的病因性预防作用均明显弱于其4-甲基对应物,略低于伯氨喹。     

Work in progress: hybrid temporal-energy subtraction in digital fluoroscopy

Initial clinical results using a digital fluoroscopic implementation of the combined time-energy ("hybrid") subtraction technique are described, with emphasis on carotid and renal imaging. Where patient motion artifacts are due to soft-tissue motion alone, hybrid subtraction can remove them. Due to the need for a finite separation time between high- and low-energy pairs, however, the present implementation of the hybrid technique is not completely immune to soft-tissue motion. The intrinsic signal-to-noise ratio of hybrid imaging is less than that of conventional temporal subtraction. However, since the low-energy temporal subtraction images are included in the hybrid data set, the diagnostic quality of the examination is not compromised.     

Traumatic brain stem injury: MR imaging

Eighty-seven patients with acute (n = 70) or chronic (n = 17) head injuries were prospectively studied with magnetic resonance (MR) imaging and computed tomography (CT) to characterize the frequency and nature of traumatic brain stem injury (BSI). Forty-eight traumatic lesions were identified in 36 patients. Of 36 patients, 35 had neurologic findings that corroborated the radiographic impression of BSI. T1- and T2-weighted MR images demonstrated a significantly higher number of lesions than did CT. Patients with BSI had a significantly higher frequency of corpus callosum and diffuse axonal "shear" lesions. The number of cortical contusions and extraaxial hematomas was similar in both groups. The mean Glasgow Coma Scale (GCS) scores at admission were significantly lower in patients with evidence of BSI on MR images. Patients with primary BSI had lower initial GCS scores, a longer duration of coma, more diffuse axonal "shear" lesions, and a higher frequency of corpus callosum injury than patients with secondary BSI. The location of primary and secondary lesions was significantly different. Overall, MR imaging was more helpful than CT in detecting, localizing, and characterizing BSI.     

Fibrin and poly(lactic-co-glycolic acid) hybrid scaffold promotes early chondrogenesis of articular chondrocytes: an <Emphasis Type="Italic">in vitro</Emphasis> study

Background  

Synthetic- and naturally derived- biodegradable polymers have been widely used to construct scaffolds for cartilage tissue engineering. Poly(lactic-co-glycolic acid) (PLGA) are bioresorbable and biocompatible, rendering them as a promising tool for clinical application. To minimize cells lost during the seeding procedure, we used the natural polymer fibrin to immobilize cells and to provide homogenous cells distribution in PLGA scaffolds. We evaluated in vitro chondrogenesis of rabbit articular chondrocytes in PLGA scaffolds using fibrin as cell transplantation matrix.     

Rapid Rh D genotyping by polymerase chain reaction-based amplification of DNA

Rh (rhesus) D is the dominant antigen of the Rh blood group system. Recent advances in characterization of the nucleotide sequence of the cDNA(s) encoding the Rh D polypeptide allow the determination of the Rh D genotype at the DNA level. This can be of help in cases in which red blood cells are not available for phenotyping, eg, when in concerns a fetus. We have tested three independent DNA typing methods based on the polymerase chain reaction (PCR) for their suitability to determine the Rh D genotype. DNA derived from peripheral blood mononuclear cells from 234 Rh-phenotyped healthy donors (178 Rh D positive and 56 Rh D negative) was used in the PCR. The Rh D genotypes, as determined with a method based on the allele-specific amplification of the 3' noncoding region of the Rh D gene described by Bennett et al (N Engl J Med 329:607, 1993), were not concordant with the serologically established phenotypes in all cases. We have encountered 5 discrepant results, ie, 3 false-positive and 2 false-negative (a father and child). Rh D genotyping with the second method was performed by PCR amplification of exon 7 of the D gene with allele-specific primers. In all donors phenotyped as D positive tested so far (n = 178), the results of molecular genotyping with this method were concordant with the serologic results, whereas a false-positive result was obtained in one of the D-negative donors (also false-positive in the first method). Complete agreement was found between genotypes determined in the third method, based on a 600-bp deletion in intron 4 of the Rh D gene described by Arce et al (Blood 82:651, 1993), and serologically determined phenotypes. The Rh blood group system is complex, and unknown polymorphisms at the DNA level are expected to exist. Therefore, although genotypes determined by the method of Arce et al were in agreement with serotypes, it cannot yet be regarded as the golden standard. More experience with this or other methods is still needed.     

细胞角蛋白20检测在大肠癌微转移中的临床意义

近年来随着微转移在肿瘤研究领域中的广泛开展,人们开始研究大肠癌微转移,以期获得更准确,更早期的转移信息,为临床分期及预后判断、辅助治疗提供更多的依据．随着分子生物学、分子免疫学的迅速发展．使大肠癌的淋巴结、血液、骨髓及各脏器等用常规组织学难以诊断的癌细胞微转移灶的检测成为可能．细胞角蛋白20(cytokeratin-20,CK20)是新近发现的一种多肽,局限在胃肠上皮细胞,具有严格的组织特异性,几乎所有大肠癌都明显表达,优于其他标志物,尤其实用于检测大肠癌微转移．通过检测大肠癌患者淋巴结、血液、骨髓中CK20 mRNA的表达来诊断微转移,对指导临床大肠癌的分期、判断预后复发、指导治疗显示出较高的临床应用价值．微转移是一项独立的预后指标．其价值优于 Dukes分期和肿瘤分级．现综述细胞角蛋白20 检测在大肠癌微转移中的临床应用及意义研究进展．     

Value of rectosigmoidoscopy with biopsies for diagnosis of inflammatory bowel disease in children

BACKGROUND: In children with inflammatory bowel disease (IBD), treatment depends on the type and extent of disease. Therefore, maximal effort should be made to provide a correct diagnosis. The aim of this study was to assess the value of a histologic diagnosis made on the basis of either ileal and colonic or rectosigmoid biopsies. METHODS: In 42 children with a known diagnosis of IBD, biopsies from rectum and sigmoid were reassessed by an expert, blinded pathologist. This histologic diagnosis was compared with the diagnosis based on (ileo)colonic biopsies and the final diagnosis. RESULTS: In patients with IBD, diagnostic accuracy of rectosigmoid histology was 0.4524. For (ileo)colonic biopsies, diagnostic accuracy was 0.7619. CONCLUSIONS: Histology on biopsies from rectum and sigmoid is insufficient for a correct diagnosis of Crohn's disease or ulcerative colitis in children. At initial presentation, an ileocolonoscopy with biopsies should therefore be performed in all children.