Comparison of radioiodine biokinetics following the administration of recombinant human thyroid stimulating hormone and after thyroid hormone withdrawal in thyroid carcinoma

Iodine kinetics were studied in patients with differentiated thyroid cancer while euthyroid under exogenous thyroid stimulating hormone (TSH) and while hypothyroid to detect differences in radioiodine uptake, distribution and elimination. Nine patients with total or near-total thyroidectomy on thyroid hormone suppressive therapy received two or three daily doses of 0.9 mg recombinant human TSH (rhTSH) followed by administration of a diagnostic activity of 2 mCi (74 MBq) iodine-131. After the biokinetics assessments had been performed, patients stopped taking thyroid hormones to become hypothyroid. A second 2 mCi (74 MBq) diagnostic activity of ¹³¹I was administered, followed by a second set of biokinetics assessments. One week later the patients underwent remnant ablation with a therapeutic activity of ¹³¹I. A comparison of the ¹³¹I kinetics in the patients while euthyroid and while hypothyroid showed major differences in the doses to the remnant as well as in residence times and radiation exposure to the blood. In the first diagnostic assessment the remnant dose was higher in eight of the nine patients and clearance of the activity from the blood was faster in all of them. The data from this study suggest that radioiodine administration is potent and safe when administered to euthyroid patients following rhTSH administration. Enhanced residence time in the remnant and decreased radiation exposure to the blood were noted when patients were euthyroid compared to when they were rendered hypothyroid. However, all patients received diagnostic activities in the same order: first while euthyroid, followed by hypothyroidism. It is quite possible that "stunning" from the radioiodine administered in the initial uptake study inhibited the subsequent uptake of radioiodine by the remnant lesions in the second uptake study.     

ETA receptor-mediated Ca2+ mobilisation in H9c2 cardiac cells

Expression and pharmacological properties of endothelin receptors (ETRs) were investigated in H9c2 cardiomyoblasts. The mechanism of receptor-mediated modulation of intracellular Ca(2+) concentration ([Ca(2+)](i)) was examined by measuring fluorescence increase of Fluo-3-loaded cells with flow cytometry. Binding assays showed that [125I]endothelin-1 (ET-1) bound to a single class of high affinity binding sites in cardiomyoblast membranes. Endothelin-3 (ET-3) displaced bound [125I]ET-1 in a biphasic manner, in contrast to an ET(B)-selective agonist, IRL-1620, that was ineffective. The ET(B)-selective antagonist, BQ-788, inhibited [125I]ET-1 binding in a monophasic manner and with low potency. An ET(A)-selective antagonist, BQ-123, competed [125I]ET-1 binding in a monophasic manner. This antagonist was found to be 13-fold more potent than BQ-788. Immunoblotting analysis using anti-ET(A) and -ET(B) antibodies confirmed a predominant expression of the ET(A) receptor. ET-1 induced a concentration-dependent increase of Fluo-3 fluorescence in cardiomyoblasts resuspended in buffer containing 1mM CaCl(2). Treatment of cells with antagonists, PD-145065 and BQ-123, or a phospholipase C-beta inhibitor, U-73122, abolished ET-1-mediated increases in fluorescence. The close structural analogue of U-73122, U-73343, caused a minimal effect on the concentration-response curve of ET-1. ET-3 produced no major increase of Fluo-3 fluorescence. Removal of extracellular Ca(2+) resulted in a shift to the right of the ET-1 concentration-response curve. Both the L-type voltage-operated Ca(2+) channel blocker, nifedipine, and the ryanodine receptor inhibitor, dantrolene, reduced the efficacy of ET-1. Two protein kinase C inhibitors reduced both potency and efficacy of ET-1. Our results demonstrate that ET(A) receptors are expressed and functionally coupled to rise of [Ca(2+)](i) in H9c2 cardiomyoblasts. ET-1-induced [Ca(2+)](i) increase is triggered by Ca(2+) release from intracellular inositol 1,4,5-trisphosphate-gated stores; plasma membrane Ca(2+) channels and ryanodine receptors participate in sustaining the Ca(2+) response. Regulation of channel opening by protein kinase C is also involved in the process of [Ca(2+)](i) increase.     

Regional serotonin transporter availability and depression are correlated in Wilson’s disease

Summary. In patients with Wilsons disease (WD), depression is a frequent psychiatric symptom. In vivo neuroimaging studies suggest that depression and other neuropsychiatric disorders are associated with central serotonergic deficits. However, in vivo measurements of serotonergic neurotransmission have not until now been performed in patients with this copper deposition disorder. The present prospective study revealed that depressive symptomatology is related to an alteration of presynaptic serotonin transporters (SERT) availability as measured by [¹²³I]-2-carbomethoxy-3-(iodophenyl)tropane ([¹²³I]-CIT) and high-resolution single-photon emission computed tomography (SPECT). SERT imaging with [¹²³I]-CIT-SPECT could therefore become a useful tool for diagnosis and therapy monitoring in depressed WD patients.Received December 10, 2001; accepted March 24, 2003 Published online June 10, 2003     

The degree of depression in Hamilton rating scale is correlated with the density of presynaptic serotonin transporters in 23 patients with Wilson's disease

Objective: One of the most frequent psychiatric symptoms in patients with Wilson's disease (WD) is depression. It has been suggested that depression is associated with deficits in serotonergic neurotransmission, but, hitherto, no measurements have been performed in WD. Methods: We prospectively examined 23 adult patients (12 women, 11 men, mean age 40 years) with WD for symptoms of depression using the Hamilton rating scale for depression (HAMD). We correlated the data with the presynaptic serotonin transporter density (SERT density) in the thalamus–hypothalamus and the midbrain–pons regions measured with high resolution single-photon emission computed tomography (SPECT) 24 hours after the application of 180 MBq 2β-carbomethoxy-3β-(4 [¹²³I]iodophenyl)tropane ( [¹²³I]b-CIT). The regions of interest were determined by coregistration with a standard MRI dataset. Results: A significant negative correlation was found between HAMD and SERT density in the thalamus–hypothalamus region (r = −0.49, p = 0.02), but not in the midbrain–pons (r = −0.31, p = 0.15). Conclusions: We conclude that depression in patients with Wilson's disease is correlated with alterations of serotonergic neurotransmission in the thalamus–hypothalamus region. Received: 24 July 2002, Received in revised form: 20 November 2002, Accepted: 28 November 2002 Correspondence to Wieland Hermanns, MD     

Higher occupancy of muscarinic receptors by olanzapine than risperidone in patients with schizophrenia. A[123I]-IDEX SPECT study

RATIONALE: In vitro data have shown anticholinergic properties of the atypical antipsychotic drug olanzapine. Substantial occupancy of muscarinic receptors may be an explanation for the low incidence of extrapyramidal side effects induced by olanzapine. OBJECTIVES: To obtain an in vivo measurement of muscarinic receptor occupancy by olanzapine compared with risperidone in patients with schizophrenia stabilised on medication. METHODS: Five patients with schizophrenia treated with olanzapine and five patients treated with risperidone were studied. Muscarinic receptor occupancy in the striatum and cortex was studied in vivo with SPECT using [123I]-IDEX as a radioligand. SPECT data were compared with those of six healthy subjects. RESULTS: Patients stabilised on olanzapine showed significantly lower mean (+/-SD) striatal and cortical (1.50+/-0.21 and 1.51+/-0.22, respectively) muscarinic receptor binding ratios of [123I]-IDEX (reflecting higher levels of muscarinic receptor occupancy) than controls (3.91+/-0.61 and 3.65+/-0.70, respectively). Furthermore, [123I]-IDEX binding ratios in patients treated with risperidone were slightly lower than controls, reaching significance only in the striatum (2.99+/-0.27 versus 3.91+/-0.61, for risperidone and controls). CONCLUSIONS: The substantial occupancy of muscarinic receptors in the striatum and cortex by olanzapine may be an explanation for the low incidence and severity of extrapyramidal side effects of this antipsychotic drug. Furthermore, it may also explain the anticholinergic side effects of olanzapine.     

内皮素及其A受体在兔颅脑创伤后脑血流量变化中的作用及意义

目的:了解内皮素(ET)及其A受体在颅脑创伤后脑血流量变化中的作用及意义.方法:130只家兔致以左额顶叶为着力部位的加速性撞击伤,动态观察脑组织内皮素含量变化、内皮素A受体mRNA表达和定位变化,内皮素A受体拮抗剂BQ123的作用及上述变化对脑血流量变化的影响.结果:脑创伤后血浆、脑脊液和局部脑组织内皮素含量显著升高;内皮素A受体mRNA主要分布于脑血管内皮细胞,表达显著增强;创伤后局部脑血流量显著降低,应用BQ123治疗的动物,血流量下降被明显抑制.结论:内皮素通过其A受体的调节在颅脑创伤后脑缺血的形成中有重要作用;应用内皮素A受体拮抗剂可以防治颅脑创伤后脑缺血.     

非毒性甲状腺肿~(131)Ⅰ治疗临床疗效分析

目的:评价131Ⅰ治疗非毒性甲状腺肿临床疗效。方法:非毒性甲状腺肿患者49例(12例甲减),经131Ⅰ(剂量3.7～7.4 Mbq/g投药)治疗6个月,ECT测量甲状腺大小,观察甲状腺缩小情况。结果:非毒性甲状腺肿经131Ⅰ治疗6个月后甲状腺体积明显缩小。甲状腺质量由治疗前(69.3±21.7)g缩小到(37.5±11.6)g(P<0.01)。随访60个月新发甲状腺功能减退35.1%(13/37例);最长随访10年无甲状腺癌等严重并发症出现。结论:131Ⅰ治疗非毒性甲状腺肿安全,简便,有效。     

种植材料生物学特性对牙种植体生物相容性的影响

牙种植体材料主要分为：钛及其合金、生物活性陶瓷、碳和高分子材料。文章从这几种材料的生物学特性入手，介绍了这几种材料的优点及存在的问题；探讨了种植体表面形态、种植体的长度和直径对应力分布的影响；证实了种植体表面的涂层、种植体的生物力学对种植体材料的生物相容性都发挥着不同程度的作用。     

Effects of cigarette smoking on iodine 123 N-isopropyl-p-iodoamphetamine clearance from the lung

Iodine 123 N-isopropyl p-iodoamphetamine (¹²³I-IMP), originally developed as a brain scanning agent, is also taken up by the lung. To evaluate the effects of cigarette smoking on the kinetics of IMP in the lung, we studied ¹²³I-IMP clearance from the lung in 18 volunteers (8 non-smokers and 10 smokers). After the injection of 111 MBq of ¹²³I-IMP into the medial cubital vein, the time-activity curve for 60 min and the regional activity using 1 frame per minute and a 64 × 64 matrix were obtained. The ¹²³I-IMP clearance curve was described as follows: C (t) = A ₁e^–k ₁ t+ A ₂e^–k ₂ t (A1, A ₂: intercepts, and k ₁, k ₂: slopes of the exponential components). ¹²³I-IMP clearance was delayed in smokers, and k ₂ was smaller in smokers. Also, a correlation between k ₁, k ₂, and the number of cigarettes smoked per day was found (r = –0.65, r = –0.74, respectively, P<0.01). In conclusion, this study suggests that the delayed clearance and retention of ¹²³I-IMP in the lung indicate lung metabolic disorders due to cigarette smoking.Offprint requests to: K. Kato     

193 nm氟化氩激光应用于屈光性角膜切削的精确性及预测性

1975年有学者发现了准分子激光并将它应用于角膜屈光性手术，使屈光手术有了重大突破，成为现代眼科学中发展最快的领域之一。波长为193 nm的氟化氩激光可以使角膜组织分子气化，故准确度非常高，而且对于被照射部位旁边的组织不产生热效应，对角膜的构造不会产生不良的效应。目前准分子激光已成功应用于角膜放射状切开术、准分子激光屈光角膜切削术、准分子激光原位角膜磨镶术、准分子激光角膜上皮瓣下磨镶术及机械法准分子上皮下角膜磨镶术等。随着对准分子激光认识的不断深入，以及临床经验的不断积累，新的、精确度高的、预测性好的准分子激光屈光性角膜手术方式将不断涌现。