血卟啉衍生物对人胃癌不同周期时相细胞线粒体及琥珀酸脱氢酶的光动力学作用

采用体外培养的人胃癌细胞,用高压N_2O方法及过量TdR的阻断与释放,制备出同步的G_1、s、G_2、M期细胞。各期细胞用血卟啉衍生物(HPD)加红光照射后,在0、24、36、60小时分别用罗丹明123显示活细胞线粒体,同时用细胞化学方法显示细胞内琥珀酸脱氢酶的动态变化。本研究结果表明,同步化各时相细胞在光照后立即观察,线粒体均模糊或消失,而琥珀酸脱氢酶反应并未完全消失,在光敏后24小时最弱,随着时间的推移,先是细胞内线粒体结构逐渐得到恢复,随后才是酶反应的恢复。4个时相细胞中,线粒体和琥珀酸脱氢酶恢复速度依次为s、G_2、G_1、M期,说明HPD对人胃癌细胞的作用有其周期特异性。本文还对HPD光动力学作用于不同周期时相细胞的线粒体损伤、琥珀酸脱氢酶的变化,及对细胞杀伤之间的关系进行了讨论。     

Single Photon Emission Computed Tomography (SPECT) Findings Using N-Isopropyl-p-[123I]iodoamphetamine (123I-IMP) in Schizophrenia and Atypical Psychosis

Abstract: As a basis for possible classification of schizophrenic psychoses into schizophrenia and atypical psychosis, we studied the brain functional differences among 16 schizophrenic patients, 16 atypical psychosis patients and 16 healthy volunteers by single photon emission computed tomography (SPECT) using N-isopropyl-p-[¹²³I]iodoamphetamine. As a result, schizophrenics showed hypofrontality. On the other hand, atypical psychotics had no such hypofrontality but showed a reduced uptake rate in the right thalamic region. No influence of sex, duration of illness and medication was confirmed by the findings. The results suggest that schizophrenics might have some lesions in the frontal regions, whereas atypical psychotics might have no such lesions, but dysfunction in the right thalamic region. Consequently, the SPECT findings at least indicate possibly different etiologies for schizophrenia and atypical psychosis.     

^123I-间碘苄胍显像对儿童神经母细胞瘤诊断和分期的临床价值

分析了１０９例初诊的神经母细胞瘤（ＮＢ）和节神经母细胞瘤（ＧＮＢ）患儿及５９例其它肿瘤患者的~（１２３）Ｉ－间磺苄呱（ＭＩＢＧ）显像结果，~（１２３）Ｉ－ＭＩＢＧ检出神经母细胞瘤的准确率是９２％，与其它影像学方法（ＣＴ、超声、Ｘ线）以及骨髓组织细胞学检查方法相比较，~（１２３）Ｉ－ＭＩＢＧ的灵敏度对原发瘤是９０％，对骨或骨髓转移是８３％，对于尿中儿茶酚胺含量正常的患者检出病灶的灵敏度是８０％，本研究证明~（１２３）Ｉ－ＭＩＢＧ作为一种高灵敏度，高特异性的示踪剂在神经母细胞瘤的诊断及分期中起着重要的作用。     

123/125I]RTI-55, an in vivo label for the serotonin transporter.

[123I]RTI-55, an iodinated derivative of the cocaine analog 3 beta-phenyltropane-2 beta-carboxylic acid methyl ester, was evaluated as an agent for in vivo labeling of the serotonin transporter. Labeling of the precursor of RTI-55 with I-123 was efficient and yielded a high specific activity product. After intravenous injection of [123I]RTI-55 into rats, the tracer accumulated in regions with high densities of serotonin and dopamine uptake sites. The distribution of [123I]RTI-55 binding in areas rich in serotonin uptake sites correlated with [3H]serotonin uptake measured in vitro in the same regions. Specific [123I]RTI-55 binding to serotonin uptake sites was inhibited by paroxetine but not by GBR 12,909. Treatment of rats with neurotoxic doses of fenfluramine caused decreases of 66% (in the hypothalamus) to 83% (in the superior colliculi) of specific [125I]RTI-55 binding in all areas except in the striatum and the olfactory tubercles (regions rich in dopamine transporters). These results indicate that [123/125I]RTI-55 binds, although not selectively, to the serotonin transporter in vivo. Furthermore, they suggest that [123I]RTI-55 holds promise as a SPECT imaging agent for the study of the serotonin transporter in humans in health and disease.     

Single photon emission computed tomography with123I-IMP in three cases of the neuroleptic malignant syndrome

Single photon emission computed tomography (SPECT) perfusion brain scans using¹²³I-N-isopropyl-p-iodoamphetamine (¹²³I-IMP) were performed in three patients with the neuroleptic malignant syndrome (NMS). In two accumulation was increased in the left basal ganglia and decreased in the right on the early images during the active phase of NMS; this asymmetry was not seen after recovery. In the third patient two examinations were performed during the active phase; on the first, increased accumulation of¹²³I-IMP in the left basal ganglia was found on the early images, but on the second, increased accumulation of tracer was found in the right basal ganglia on the delayed images. These abnormalities disappeared after improvement of the NMS. These results suggest that a disturbance in the basal ganglia is related to the development of NMS.     

Studies of rhodamine-123: Effect on rat prostate cancer and human prostate cancer cells in vitro

The effect of the lipophilic, cationic dye, Rhodamine-123 (Rh-123), on prostate cancer in rats, and on three tumor cell lines in vitro is reported here. The general toxicity of Rh-123 in mice has been found to be minimal. Lobund-Wistar (L-W) rats with the autochthonous prostate cancer of Pollard were treated for six doses with Rh-123 at a dose of 15 mg/kg subcutaneously every other day. Microscopic examination of the tumors revealed cellular and acinar destruction. The effectiveness of Rh-123 as a cytotoxic agent was tested by clonogenic and viability assays in vitro with three human prostate cancer cell lines. Severe (60-95%) growth inhibition was observed following Rh-123 exposure for 2–5 days at doses as low as 1.6 μg/ml in all three prostate cancer cell lines.     

Human Polyomavirus Is Associated With Earlier Onset of Upper Urinary Tract Urothelial Carcinoma in Patients After Kidney Transplantation

Objectives

Polyomavirus has been reported to be oncogenic due to viral integration into the human genome. A relatively high prevalence of upper urinary tract urothelial carcinoma (UTUC) was noted after kidney transplantation (KT) in Taiwan. However, little was known about the impact of polyomavirus on the urothelial cancer behavior. Therefore, the aim of this study is to analyze the characteristics of polyomavirus-related UTUC after KT.

High amino acid uptake in a low-grade desmoplastic infantile ganglioglioma in a 14-year-old patient

Amino acid uptake is higher in high-grade than in low-grade gliomas; this is the rationale for using radioactively labelled amino acids for the non-invasive grading of brain neoplasms. We present a 14-year-old boy with a low-grade desmoplastic infantile ganglioglioma (DIG) that exhibited marked contrast enhancement on magnetic resonance imaging (MRI), but no signs of infiltration and only minimal surrounding edema. In this benign neoplasm the relative uptake of the radioactively labelled amino acid I-123--methyl tyrosine (IMT), determined using single-photon emission computed tomography (SPECT), was 3.24; it was considerably higher than that of eleven other pretherapeutic low-grade gliomas where it ranged from 1.06 to 1.94 and also markedly above the average value of 2.37 found in 20 high-grade gliomas. This case report illustrates that results from emission tomography with radioactively labelled amino acids must be interpreted with caution, particularly when rare tumor entities are considered in view of uncommon clinical or radiological findings.     

Effect of 1-methyl-4-phenylpyridinium (MPP+) on mitochondrial membrane potential in cerebellar neurons: Interaction with the NMDA receptor

Summary The effect of MPP⁺, a dopaminergic neurotoxin, in mitochondrial membrane potential was investigated in dissociated cerebellar granule cells using rhodamine 123 and flow cytometry. MPP⁺ (1 mM) decreased the mitochondrial membrane potential by 30%. Antagonists of the NMDA receptor complex, such as MK-801 (IC₅₀ value of 20.92 ± 0.02 nM), 5,7-dichlorokynurenic acid (IC₅₀ value of 6.46 ± 1.06 M) and D-AP5 (IC₅₀ value of 8.29 ± 0.63 M), inhibited the action of MPP⁺. Neither NBQX, nor riluzole, nor desipramine modified the action of MPP⁺. Dibucaine restored the basal values of mitochondrial membrane potential altered by MPP⁺. Since, in the presence of NMDA, MPP⁺ antagonized the effect of this total agonist, it can be concluded that, in this preparation, MPP⁺ interacts with the NMDA receptor complex as a partial agonist. This interaction could be the result of an allosteric modulation of the NMDA receptor complex by MPP⁺. The decrease of mitochondrial membrane potential induced by MPP⁺ is antagonized by dibucaine, suggesting that this effect is mediated by an activation of phospholipase A₂.