Idiotypic characterization of antibody-induced antibody responses

Anti-idiotypic antisera were produced in syngeneic (C57BL/6) mice against a monoclonal anti-Dextran B512 (Dex) antibody (38-13). In radioimmunoassays, anti-idiotypic antibodies were shown to react with the homologous idiotype, while failing to recognize another monoclonal anti-Dex antibody, independently derived from C57BL/6 mice (D-16). Plaque inhibition tests confirmed the specificity of the anti-idiotypic antibodies and revealed that the 38-13 idiotype is expressed by about half of all anti-Dex antibodies produced in C57BL/6, but not in CBA mice. Injection of normal (but not athymic) C57BL/6 mice with low doses of 38-13 monoclonal antibodies, contained culture supernatants or ascitic fluids, resulted in a 10-20 fold increase in the numbers of anti-Dex PFC detected in the spleen 5 days later, the majority of which carried the 38-13 idiotype.     

Sodium regulation of agonist and antagonist binding to β-adrenoceptors in intact and Ns-deficient membranes

Summary Agonist binding to various hormone receptors mediating adenylate cyclase inhibition is decreased by sodium ions. We studied the influence of Na⁺ on agonist and antagonist binding to -adrenoceptors in membrane preparations of guinea pig lung, S49 lymphoma wild-type cells (WT) and their N_s-deficient cyc^– variants by measuring binding of the antagonist, [¹²⁵I]iodocyanopindolol ([¹²⁵I]CYP). At 37° C, sodium decreased the receptor affinity for the agonist, isoproterenol, in all three membrane preparations. In lung and WT membranes, Na⁺ steepened the shallow agonist competition curves in a manner similar to and synergistic with guanine nucleotides. When binding was performend at 4° C, sodium regulation but not guanine nucleotide regulation of agonist binding was preserved. At the low temperature, [¹²⁵I]CYP affinity was reduced, and sodium increased [¹²⁵I]CYP binding in both N_s-containing and N_s-deficient membranes by increasing the antagonist affinity without significant change in total receptor number. Compared to Na⁺, Li⁺ and K⁺ were much less potent and efficient in decreasing agonist and increasing antagonist binding. Na⁺ and Mg²⁺ had opposite effects on agonist binding in the N_s-containing lung and WT membranes but not in the N_s-deficient cyc^– membranes. The data indicate that sodium not only regulates binding of inhibitory hormone receptors but also agonist and antagonist binding to the adenylate cyclase stimulatory -adrenoceptor. The finding that sodium regulation of -adrenoceptor binding is also observed in the N_{s 2} cyc^– membranes, furthermore, indicates that the target of sodium is not the -subunit of N_s but possibly a component common to both types of receptor systems regulating adenylate cyclase activity.     

改性壳聚糖基导电复合材料神经导管的体内降解及组织相容性观察

目的探讨改性壳聚糖基导电复合材料神经导管的体内降解及组织相容性，以期为组织工程神经构建提供新的支架材料。方法采用微乳液聚合法合成纳米聚吡咯（polypyrrole，PPy），与壳聚糖共混后注入定制的成管模型，冷冻干燥及脱酸后，制成改性纳米 PPy/壳聚糖复合材料导管（记作 CP 导管）；再经不同程度乙酰化（乙酰化反应时间分别为 30、60、90 min）改性，制备不同乙酰度的 CP 导管（记作 CAP1、CAP2、CAP3 导管）。各导管予红外光谱、扫描电镜进行表征，使用四探针电导仪测定电导率。取 30 只雌性 SD 大鼠，于背部左、右侧各制备 4 个皮下筋膜隧道，分别植入上述导管。术后 2、4、6、8、10、12 周取材，大体观察导管形态及完整性、扫描电镜观察导管微观结构、测量导管降解率，以观察导管体内降解性能；行 HE 染色及抗巨噬细胞免疫荧光染色，观察导管体内组织相容性。结果经表征证实乙酰化改性后的各导管 1 562 cm^–1左右的酰胺Ⅱ谱带增强，表示壳聚糖乙酰化改性成功。各导管均具备导电性能，组间电导率差异无统计学意义（P>0.05）。扫描电镜观察示各导管表面相对光滑、结构致密，无明显差异。导管植入体内后，随时间延长均出现一定程度塌陷，其中 CAP3 导管尤为明显；亦出现不同程度质量丢失，且乙酰化度越高，质量变化越大（P<0.05）。扫描电镜观察示植入 12 周后材料出现较多孔隙，且随着乙酰化度增加，孔隙呈增大趋势。组织学观察显示术后早期各导管均有较多巨噬细胞、淋巴细胞浸润，随着植入时间延长，淋巴细胞有所减少、成纤维细胞增多、胶原纤维增生明显。 结论不同乙酰度的改性壳聚糖基导电复合材料神经导管均有较好的体内生物相容性、可导电、可降解，且降解性与乙酰度相关，有望为组织工程神经构建提供一种新的支架材料。     

PTPRQ基因的内耳功能及突变致聋机制的研究进展

受体型蛋白酪氨酸磷酸酶Q(Receptor type protein tyrosine phosphatase Q,PTPRQ)作为一种蛋白酪氨酸磷酸酶,能催化不同的底物,参与多种细胞内的功能.PTPRQ基因突变可导致常染色体隐性和显性非综合征性耳聋DFNB84A型和DFNA73型耳聋的发生,两型耳聋的临床表型差异提示...     

超声S-Detect技术在乳腺肿块诊断中的价值

目的探讨超声S-Detect技术在乳腺肿块病灶诊断中的应用价值。方法采用S-Detect技术及常规超声对62例女性患者总计85个乳腺肿块进行诊断，以术后病理结果为金标准，对比分析常规超声与S-Detect技术的诊断效能。结果低年资医师常规超声诊断效能低于S-Detect技术（P < 0.05），中年资、高年资医师常规超声诊断效能与S-Detect技术无显著差异（P>0.05）。S-Detect技术与高年资医师诊断结果呈正相关（r=0.97）。S-Detect技术长轴切面和长轴垂直切面的诊断效能无显著差异（P>0.05）。中年资医师常规超声诊断直径≤20 mm乳腺肿块的效能优于S-Detect技术（P < 0.05），但诊断直径>20 mm乳腺肿块的效能低于S-Detect技术（P < 0.05）。结论S-Detect技术可用于乳腺良恶性肿块的鉴别诊断，其诊断效能可达到中、高年资医师BI-RADS分类的诊断水平，但在诊断直径不足20mm乳腺肿块时的效能并不十分理想。