Differential Regulation of RGS-2 by Constant and Oscillating PTH Concentrations

PTH has diverse effects on bone metabolism: anabolic when given intermittently, catabolic when given continuously. The cellular mechanisms underlying the varying target cell response are not clear yet. PTH induces RGS-2, a member of the Regulator of G-protein Signaling protein family, via cAMP/PKA, and inactivates PKC-mediated signaling. To investigate intracellular signaling pathways with different PTH concentration-time patterns, we treated UMR 106-01 osteoblast-like cells in a perfusion system. PTH was administered intermittently (4 min/h, 10⁻⁷ M) or continuously at an equivalent cumulative dose (6.6 × 10⁻⁹ M). cAMP was measured using radioimmunoassay, mRNA levels using real-time rtPCR and ribonuclease protection assay, and protein levels using Western immunoblotting. A single PTH pulse transiently increased cAMP levels by 2000% ± 1200%. In contrast to continuous PTH exposure, cAMP induction remained unchanged with intermittent PTH, ruling out desensitization of the PTH receptor. In continuously perfused cells, RGS-2 abundance was three to five times higher than in cells intermittently exposed to PTH for up to 12 h. MKP-1 and -3 were significantly less induced with pulsatile PTH; exposure-mode-dependent differences in MMP-13 and IGFBP-5 were small. Pulsatile but not continuous PTH administration prevents PTHrP receptor desensitization and accumulation of RGS-2 in osteoblasts, which should preserve PKC-dependent signaling.     

后纵隔巨大甲状腺乳头状癌一例

患者女,48岁。两年前无明显诱因出现轻微进食梗噎感,抬头时加重,未予治疗。近半年,梗噎感加重,并出现胸闷、咳嗽,痰中带血,遂来我院就诊。胸部CT显示:左后纵隔食管后方见一长条形低密度影,密度不均,其上方见环形斑     

Stimulation of Alpha-Adrenoceptors Facilitates the Release of Growth Hormone-Releasing Hormone from Rat Hypothalamus in vitro

While extensive evidence suggests that adrenoceptors play an important role in the control of growth hormone in the rat, there are few studies involving the direct measurement of growth hormone-releasing hormone (GHRH). We have therefore developed a radioimmunoassay for rat GHRH, and used it to investigate the modulation of GHRH release by noradrenaline from incubated rat hypothalamus in vitro. The GHRH radioimmunoassay had no significant cross-reactivity with other hypothalamic or GHRH-related peptides, and was sensitive to 4 pg/tube; intra- and interassay coefficients of variation were 6% and 12% respectively. Single incubated rat hypothalami produced a stable and readily measurable output of GHRH in successive 20 min incubations after an initial 60 min preincubation; the release of GHRH was increased in the presence of 56 mM KCI, but did not respond to KCI-depolarization when calcium was excluded from the medium. Stimulated GHRH release was identical to synthetic rat GHRH(1–43) on high-performance liquid chromatography and Sephadex G-75 chromatography.
Noradrenaline stimulated GHRH secretion in a dose-dependent manner in the concentration range 10⁻¹⁰— 10⁻⁶M, with a plateau in response at 10⁻⁷M. Stimulation with noradrenaline 10⁻⁷M was blocked by idazoxan 10⁻⁵M and attenuated by thymoxamine 10⁻⁵M, but was unaffected by timolol 10⁻⁵M. Both the α₂-adrenoceptor agonist guanfacine, and the α₁-adrenoceptor agonist methoxamine, specifically stimulated GHRH secretion.
It is concluded that noradrenaline stimulates the release of GHRH at both α₁ and α₂-adrenoceptors.     

人参皂苷对人肝细胞HL-7702内性激素受体水平的影响

目的 观察人参皂苷（ginsenoside,GSS）对人肝细胞HL-7702内性激素受体水平的调节作用。方法 以四唑盐比色法（MTT）观察细胞生长以确定药物浓度，应用免疫组化法，免疫蛋白印迹法（Western blot）和RT PCR法分析人参皂苷对HL-7702细胞性激素受体蛋白和其mRNA水平的影响。结果 随GSS药物浓度增大，细胞内雌激素受体（estrogen receptor，ER）、孕激素受体（progesterone receptor，PR）、雄激素受体（androgen receptor，AR）蛋白及mRNA表达水平均逐渐增高，与溶剂对照组比较，差异有统计学意义（P<0.05），且细胞内性激素受体蛋白及mRNA表达呈剂量依赖性增加。结论 GSS可上调HL-7702细胞内性激素受体蛋白及mRNA的表达。     

Insular carcinomas of the thyroid exhibit poor prognosis and long-term survival in comparison to follicular and papillary T4 carcinomas

Background Insular thyroid carcinoma was described as a tumor with aggressive behavior, and patients usually present themselves with an advanced tumor stage. Whether the insular component is an independent factor for poor prognosis remains unclear. Therefore, in the present study, we compared the survival of patients with advanced insular, follicular, and papillary thyroid cancer. Materials and methods The clinical behavior of tumors in three groups of patients with T4 thyroid carcinoma—8 patients with insular, 11 patients with follicular, and 21 patients with papillary thyroid carcinomas—was compared. Disease-free survival and disease-specific death were analyzed statistically. Cox regression analysis was used to evaluate the influence of histotype and other prognostic factors. Results At 3 years, survival was 37.5% (mean 26 months) among patients with insular thyroid carcinoma, 80% (mean 59 months) among those with follicular, and 89% (mean 126 months) among those with papillary thyroid carcinomas (p = 0.007). Disease-free survival in patients without initial distant metastasis was worst in patients with insular thyroid carcinoma (20%) compared to those with follicular (75%) and those with papillary thyroid carcinomas (71%). Conclusion Patients with advanced insular thyroid carcinoma have a poorer outcome in comparison to patients with similar advanced stage who have follicular or papillary thyroid carcinoma.     

舌异位甲状腺的诊断与治疗

目的 :探讨舌异位甲状腺诊治方法。方法 :将我院从 1992年 10月～ 2 0 0 0年 2月收治的 18例舌异位甲状腺患者的临床资料进行总结分析 ,其中异位甲状腺全切除术 5例 ,部分切除术 3例 ,次全切除加部分带蒂移植10例。结果 :1例异位甲状腺癌行全切除术后出现甲状腺功能低下 ,部分切除术后 2例复发 ,其余 15例情况良好。结论 :术前常规B超检查、同位素扫描、细胞学检查和冰冻切片对异位甲状腺的诊断有指导意义 ;治疗上 ,患者无症状 ,异位甲状腺无恶变 ,可不予治疗 ,如果出现临床症状 ,对于副甲状腺 ,可作全切除术 ,若为迷走甲状腺 ,则行次全切除加部分带蒂移植是很好的方法     

~(99)Tc~m扫描对甲状腺结节的诊断价值

目的 :评价99Tcm 核素甲状腺扫描对甲状腺结节的临床诊断价值。方法 :对 2 87例甲状腺结节患者行99Tcm 甲状腺扫描并行甲状腺手术 ,将扫描结果与术后病理诊断进行对比。结果 :扫描对各种甲状腺结节定位诊断准确 ,但各组甲状腺结节扫描定性诊断结果无差异 (P >0 .0 5 )。结论 :发现99Tcm 扫描对甲状腺结节的定位准确 ,但对甲状腺结节良恶性鉴别帮助不大。该方法快捷方便 ,病人所受辐射较少 ,尤其适用于儿童     

前列腺增生症证型与体内性激素水平的临床研究

目的:研究前列腺增生症中医证型与体内性激素水平的相关性.方法:选择500例患者,中医辨证分为血瘀下焦、膀胱湿热、肾阴亏虚、肾阳不足、肺热气闭,均在就诊次日上午抽空腹血4 mL,进行血清性激素测定.结果:T值以血瘀下焦、肾阴亏虚证较高,肾阳不足证明显偏低,两者比较差别有显著性(P＜0.01);膀胱湿热证和肺热气闭证居中,与血瘀下焦、肾阴亏虚证比较差别也具有显著性(P＜0.05).E2值以肾阳不足证明显偏高,血瘀下焦和膀胱湿热证次之,肾阴亏虚和肺热气闭证较低.各组间比较差别具有显著性(P＜0.01).结论:前列腺增生症各证型与血清性激素水平变化有一定规律可循,同时也为证型客观化、微观化提供了相应证据.     

超声引导下细针穿刺检测甲状腺乳头状癌 ret/PTC基因重组突变

目的了解ret／PTC基因突变与超声、病理诊断在甲状腺乳头状癌诊断中的关系。方法术前超声检查，并在超声引导下细针穿刺，活体取材进行病理诊断和逆转录聚合酶链（RT-PCR）方法检测ret／PTC基因突变。结果在34例超声与病理诊断的甲状腺乳头状癌（PTC）患者中，16例分子生物学检测发现ret／PTC基因突变（47％），其中8例为PTC-1基因突变（50％），2例PTC-2基因突变（12．5％），2例PCT-3基因突变（12．5％），3例PTC-1和PTC-2突变同时存在（18．75％），1例PTC-1和PTC-3突变同时存在（6．25％）。结论ret／PTC基因重组突变可存在于散发的甲状腺乳头状癌中，主要表现PTC-1型。应用超声引导下细针穿刺与甲状腺乳头状癌基因突变的检测相结合是早期诊断甲状腺乳头状癌的有效方法。