Characterization of somatomedin/insulin-like growth factor receptors and correlation with biologic action in cultured neonatal rat astroglial cells

The role of somatomedin/insulin-like growth factors (Sm/IGFs) in neural growth and development is not clearly defined. To characterize Sm/IGF receptors and to correlate binding with the biologic actions of Sm/IGFs in a homogeneous population of neural cells, we isolated and studied a nearly pure population of cultured astroglial monolayers derived from cerebral cortices of neonatal rats. Binding of radiolabeled Sm/IGFs was specific, saturable, and reversible, with 90% of the binding occurring within 6 hr of incubation at 4 degrees C. Competitive binding studies with Sm-C/IGF I yielded curvilinear Scatchard plots, while studies with IGF II and multiplication stimulating activity (MSA) yielded linear plots, suggesting that 125I-Sm-C/IGF I binds to more than 1 receptor species, and 125I-IGF II and 125I-MSA bind to one only. These findings were supported by affinity-labeling studies with radiolabeled Sm/IGFs using disuccinimidyl suberate as a cross-linking agent. Sm-C/IGF I appeared to bind to both type I and II Sm/IGF receptors, because cross-linked 125I-Sm-C/IGF I-receptor complexes with molecular weight (Mr) of greater than 300,000 (300K) and 130K (type I receptor) were observed under nonreducing and reducing conditions, respectively, as were 220 and 260K complexes (type II receptor) under the same respective conditions. 125I-IGF II and 125I-MSA, however, bound only to the Mr 220 and 260K moieties under nonreducing and reducing conditions, respectively, suggesting that these peptides bind only to the type II receptor. Competitive binding studies of the cross-linked moieties were consistent with this interpretation. In contrast, 125I-insulin bound poorly to astroglia (less than 0.5% specific binding), and cross-linking studies could not definitely distinguish among low-affinity binding to the type I Sm/IGF receptor, binding to a paucity of insulin receptors, or both. In addition, by combining autoradiography to localize 125I-Sm/IGFs binding on astroglial cells and immunocytochemistry with anti-glial fibrillary acidic protein to identify the cell type, we have demonstrated cell-surface binding and apparent internalization of radiolabeled Sm/IGFs. Concurrent studies of Sm/IGF stimulation of 3H-thymidine incorporation revealed that these cells were most sensitive to Sm-C/IGF I, followed by IGF II and MSA, and insulin. MSA and IGF II, however, were the most potent followed by Sm-C/IGF I and then insulin. Half-maximal stimulations of 3H-thymidine incorporation corresponded closely with half-maximal binding displacement for Sm-C/IGF I and less so for IGF II and MSA.(ABSTRACT TRUNCATED AT 400 WORDS)     

乳腺癌术后双肺及骨转移

疾病的正确诊断和合理治疗是患者和医务工作者共同的心愿。在广东省人民医院肿瘤中心，吴一龙教授指导临床医生应用循证医学理论进行肿瘤的多学科综合治疗，开展临床病例讨论。讨论会上各学科共同围绕一个病例或一个病种进行会诊，临床、病理、B超、放射影像等资料齐全。除相关科室提前准备的中心性发言外，到会人员各抒己见，气氛热烈。参会人员受益匪浅，提高了对疑难病例的诊治水平。为了将他们的诊治经验传播出去，让更多的临床医生获益，我刊开辟“循证病例讨论”栏目，希望广大医务工作者关注此栏目。[编者按]     

Retained intrahepatic stones: treatment with piezoelectric lithotripsy combined with stone extraction

Extracorporeal shock wave lithotripsy (ESWL) was performed in 11 patients with oriental cholangiohepatitis and intrahepatic stones associated with segmented strictures of intrahepatic ducts. All patients had previously undergone biliary surgery and basket extraction via a T-tube tract at the time of lithotripsy. The indication for ESWL was failure of, or anticipated difficulty with, basket extraction of the stones via a T-tube tract. A piezoelectric lithotriptor was used in all procedures. The average total number of shock waves administered was 29,756 (range, 10,000-61,395). The average number of treatment sessions was 3.1 (range, 1-6); the number of shock waves used in a single session ranged from 10,000 to 15,000 with a frequency of five shots per second and 30%-50% power. In six patients, the stones were successfully fragmented and completely removed; in three of the others of the stones were fragmented and removed. The overall success rate, including complete (54%) and incomplete (27%) success, was 82%. Difficulty in targeting stones, and severe strictures and deformities of intrahepatic ducts, were the factors responsible for failure. No significant complications were observed.     

Anterior transposition of the inferior oblique muscle for a snapped inferior rectus muscle following functional endoscopic sinus surgery.

A 55-year-old woman was referred with a 4-month history of diplopia following functional endoscopic ethmoidectomy for chronic sinusitis. She had right hypertropia of 14 prism diopters in the primary position that increased to 30 prism diopters in down gaze. Her right eye showed a moderate limitation of motion in down gaze. Orbital imaging demonstrated a snapped right inferior rectus muscle. The inferior oblique muscle was transposed as an initial treatment for the snapped inferior rectus muscle. After surgery, the patient was orthophoric and obtained fusion in the primary position.     

医学生营养知识与膳食状况调查

①目的了解医学生营养知识的掌握情况及对教育传播方式的需求意见，以加强营养知识教育，改善大学生的健康素质。②方法对762名在校大学生进行问卷调查。③结果医学院在校生对营养知识及常识掌握深度和广度都不够，但渴求得到营养知识的欲望比较高，对营养知识的重要性认识正确。有73．6％的学生认为营养知识对生活很重要。87．2％的学生愿意接受营养知识的教育，对营养知识教育的传播方式也表现出特有的需求意向。大学生的膳食结构不够合理，奶类、薯类、鱼虾禽类、豆制品摄入不足。④结论应加强医学生营养知识教育，使医学生做到科学合理的安排膳食，改善饮食行为，促进身体健康。     

Mechanisms of protective action of radix Salviae miltiorrhizae (RSM) against experimental hepatic injury in rats]

The results indicated that RSM could significantly inhibit the lipid peroxidation of normal livers and cultured hepatocytes of rats, induce liver microsomal cytochrome P450 in normal rats, increase nucleic acids, proteins, urea and cerolloplasmin of damaged cultured hepatocytes of rats, relieve ultrastructural damage of cultured hepatocytes induced by CCl4. The pharmacological actions mentioned above should be considered as important mechanisms of RSM against liver injury.     

Large French-Canadian family with Lewy body parkinsonism: exclusion of known loci.

The identification of rare, large families with Parkinson's disease (PD) has provided important clues that have contributed to our understanding of this complex disorder. We have identified a large French-Canadian kindred that spans five generations consisting of more than 90 individuals. A total of 65 individuals now have been examined, had venous blood drawn, and DNA extracted. Two-point and multipoint linkage analysis was performed to assess linkage to known PD genes or loci. Within the third and fourth generations of this family there are 10 living, plus 3 deceased members with well-documented levodopa responsive parkinsonism. Autopsy results on 1 member demonstrated the loss of pigmented neurons in the substantia nigra and the presence of alpha-synuclein positive Lewy bodies. Four of the PD patients have prominent postural and kinetic tremors that preceded their parkinsonism by up to 10 years. Two other individuals within the family have prominent isolated postural and kinetic tremors without parkinsonism. The alpha-synuclein(4q21.3-23), Parkin(6q25.2-27), PARK3 (2p13), PARK4, and ubiquitin carboxy terminal hydrolase-L1 (4p14-16.3) and PARK6 and PARK7 (1p35-36) loci were excluded in this kindred using closely linked markers. The clinical and pathological features of this family are consistent with the diagnosis of PD. This family further demonstrates the known genetic heterogeneity in PD and is large enough that a genome-wide screen has been undertaken in an effort to identify a novel PD gene.