Transient synovitis of the hip in children: role of US

Transient synovitis of the hip remains a common diagnostic problem for the clinician. The physical signs are not pathognomonic of the condition, and the classic technical examinations are of little help. Therefore, the authors retrospectively studied the value of hip arthrosonography in 46 children with clinical symptoms suggesting pathologic hip conditions. In 20 of the 21 patients with a final diagnosis of transient synovitis, articular effusion was detected on ultrasound (US). Conventional radiography showed an increased medial joint space in only eight of these patients. Increased echogenicity of the articular fluid was found in both transient synovitis and septic arthritis. The high sensitivity of US in detecting intraarticular fluid was demonstrated by cadaver studies.     

Mitochondrial DNA analysis of hybridization between sympatric white-tailed deer and mule deer in west Texas.

Sympatric populations of white-tailed deer and mule deer (Odocoileus virginianus and Odocoileus hemionus, respectively) on a west Texas ranch share a common mitochondrial DNA restriction map genotype. Phylogenetic analysis indicates that this genotype is more characteristic of O. virginianus than of O. hemionus. The genotype of west Texas deer differs from that of O. virginianus from South Carolina by five mutational events (1.3% sequence divergence), whereas it differs from that of O. hemionus from California by 17 events (5.5% divergence). We suggest that interspecies hybridization has occurred, primarily between mule deer bucks and white-tailed deer does, with preferential absorption of hybrid offspring into the mule deer gene pool. Introgressive hybridization may be involved in ongoing displacement of mule deer by white-tailed deer in west Texas.     

Renal artery stenosis: evaluation with intravenous digital subtraction angiography

The ability of diagnostic intravenous digital subtraction angiography (IVDSA) to demonstrate the degree of renal artery stenosis was compared with that of intraarterial angiography in 45 patients with 92 arteries. Stenotic lesions on both IVDSA and intraarterial studies were classified as normal (0% stenosis), minor (less than 50%), low grade (50%-80%), and high grade (80%-99%). There was agreement about the degree of stenosis in 90% of the cases. IVDSA grading was correct in 94% of atheromatous lesions and in 56% of the fibromuscular dysplastic lesions. In the high-grade atheromatous lesions, the degree of stenosis was slightly overestimated on IVDSA studies in 22.5% of the cases. In fibromuscular dysplasia, stenosis was underestimated in 33% of the cases.     

STREPTOCOCCAL ANTIBODY CROSS-REACTIVITY WITH HLA-DR4+VE B-LYMPHOCYTES. BASIS OF THE DR4 ASSOCIATED GENETIC PREDISPOSITION TO RHEUMATIC FEVER AND RHEUMATIC HEART DISEASE?

B-lymphocytes obtained from patients with either rheumatic feveror rheumatic heart disease and from normal subjects were reactedwith serum obtained from rabbits immunized with streptococcalcell wall antigen. The presence of cytotoxicity was sought usingan inverted phase microscope after differential uptake of eosindye. The serum was found to be significantly more cytotoxicto HLA-DR4 containing cells of both patients and normals comparedwith DR4 negative cells (P<0. 0001). KEY WORDS: Streptococcal cell wall antigen, Antiserum, Cytotoxicity     

Effects of Procainamide on the Excitable Gap Composition in Common Human Atrial Flutter

The composition of the excitable gap (EG) in common atrial flutter (AFI) was determined before and during infusion of procainamide (PA) in 9 patients (6 men and 3 women; age 70 ± 7 years). The EG was determined by introducing a premature stimulus after every 20th AFI complex detected using a quadripolar electrode catheter placed just above the tricuspid valve. Diastole was scanned in 2- to 4-ms decrements to the atrial effective refractory period (ERP). The relationship between the coupling interval and the return cycle length (CL) determined a reset-response curve (RRC), which described the EG. PA (15 mg/kg) was administered during AFl over 30 minutes and RRC was repeated at maximum AFI CL. PA prolonged AF1 CL from 227 ± 29 to 296 ± 62 ms (P < 0.01) but did not terminate AFI. ERP during AFl prolonged from 169 ± 24 to 219 ± 41 ms (P < 0.01). Control EG was 57 ± 16 ms or 25%± 6% of AFl CL and on PA EG was 77 ± 30 ms (P = 0.01), which was still 26%± 7% of the CL. Without drug, RRC was mixed in eight cases demonstrating an EG composed of fully excitable tissue (10 ± 4 ms or 19%± 10% of the EG) and partially refractory tissue (48 ± 18 ms), PA did not change the duration of the fully excitable region (13 ± 10 ms or 19%± 15% of EG). Peak PA plasma concentration was 47 ± 20 μmol/L. PA prolonged AFI CL, ERP, and EG duration but did not change the proportion of AFI CL occupied by the EG. The persistence of fully excitable tissue at the head of the wavefront in the presence of PA may largely explain its inefficacy in the acute termination of common AFl.     

胶原海绵复合新生大鼠原代心肌细胞构建工程化心肌组织

目的:探索以胶原海绵为支架、新生大鼠原代心肌细胞为种子细胞,于体外构建工程化心肌组织的方法。方法:实验于2005-12/2006-11在解放军第四军医大学西京医院心内科实验室完成。Ⅰ型胶原海绵剪切成方形片状(2.0cm×1.4cm×0.2cm),经60Co照射消毒,于DMEM培养液中水化1h左右。另取1d龄SD大鼠心脏,剪成小碎块,然后用2.5g/L胰蛋白酶于37℃中消化,吸取上清至含胎牛血清的DMEM中,重复消化四五次,用差速贴壁法除去大部分成纤维细胞,将细胞沉淀用DMEM培养液以2×109L-1的密度悬浮备用。将上述的心肌细胞悬液1mL缓慢滴注于玻璃模型中的胶原海绵上,然后置于细胞培养中培养。肉眼及显微镜主要观察工程化心肌组织在培养期间的自发收缩情况,包括收缩的部位、强度、频率、一致性以及收缩随时间变化的情况。苏木精-伊红染色观察工程化心肌组织内胶原纤维的变化,细胞形态,胞核的形状及细胞之间的连接。免疫组织化学染色和透射电镜观察工程化心肌组织片的形态和功能。结果:①细胞接种于胶原海绵上1d后,细胞/胶原复合物的凝胶化过程基本完毕,体积保持恒定,维持至培养结束,第3天细胞/胶原复合物局部出现点片状自发收缩,第5天整个细胞/胶原复合物出现同步化自发收缩,收缩频率61～199次/min。2周后37.5%的工程化心肌组织的自发收缩活动减弱,但75%的工程化心肌组织的自发收缩活动持续至培养结束。②苏木精-伊红染色、免疫组织化学染色和透射电子显微镜显示,工程化心肌组织内细胞间连接广泛存在,细胞多呈纵向分布,胞核呈长圆形,胞浆内α-肌节肌动蛋白阳性,胞内肌原纤维排列整齐,可见到心肌特异性的肌小节结构和Z线,多数细胞具有分化的心肌细胞表型。结论:用新生大鼠原代心肌细胞为种子细胞、以Ⅰ型胶原海绵为支架材料,构建出的工程化心肌组织,于体外可长时间持续自发收缩,该细胞/胶原复合物的形态结构与生理功能均类似于成熟大鼠心肌组织。