Developmental effect of dimethyl sulfoxide on hypothalamo-neurohypophysial neurons in vitro

Primary dissociated cultures were established from diencephalic tissue of 14-day-old fetal rats. Neurons exhibiting immunocytochemical staining for neurophysin appeared in these cultures after 6 days of cultivation. Addition of dimethyl sulfoxide (DMSO) to the culture medium resulted in a slight decrease in total neuronal cell mass as assessed by immunocytochemistry and radio-immunometric quantitation of neuron-specific enolase. In contrast, in DMSO-treated cultures the number of neurophysin-immunoreactive neurons was more than doubled as compared to control cultures. [3H]Thymidine labeling and autoradiography in conjunction with immunocytochemistry for neurophysin showed that this was not due to a mitogenic effect of DMSO on precursor cells. Time-course analysis of the action of DMSO revealed a 6-day time lag between the initiation of treatment and the appearance of increased numbers of neurophysin-immunoreactive cells. These findings suggest that DMSO, which has previously been reported to have a differentiation-inducing effect on malignant transformed cells, may also modulate cellular processes that control differentiation in specific types of neurons in primary culture.     

细胞核受体RXRα在2,2',4,4'-四溴二苯醚神经毒性中的作用及其机制

目的：探讨视黄醛X受体（RXRs）为核心的多个核受体在2，2'，4，4'-四溴二苯醚（BDE-47）致神经细胞毒性中的相互作用，揭示受体介导的多溴二苯醚（PBDEs）神经毒性效应的分子机制。方法：构建人神经母细胞瘤细胞SK-N-SH的RXRα基因敲除细胞株及高表达细胞株（分别命名为RXR/KO-SK-N-SH和RXR/OE-SK-N-SH细胞）；CCK-8法分别检测SK-N-SH（野生型）、RXR/KO-SK-N-SH和RXR/OE-SK-N-SH细胞在BDE-47浓度分别为1、5、10、20、50、100、150、200 μmol/L处理12、24、48、72 h时的细胞增殖率；qPCR和Western blot法分别检测上述3种细胞中RXRα、TRα、TRβ、PPARα、PPARγ的mRNA和蛋白表达水平。结果：在染毒时间分别为12、24、48、72 h时，不同浓度BDE-47作用下3种细胞的增殖率比较，差异有统计学意义（P < 0.05）。BDE-47对RXR/KO-SK-N-SH细胞的IC₅₀是野生型和RXR/OE-SK-N-SH细胞的1/2。BDE-47处理3种细胞后，RXRα的mRNA和蛋白表达水平在野生型和RXR/OE-SK-N-SH细胞中显著升高，SK-N-SH细胞和RXR/OE-SK-N-SH细胞中TRα和PPARα的表达升高，此两种受体在RXR/KO-SK-N-SH细胞中表达降低。在本实验所采用的BDE-47处理浓度下，TRβ和PPARγ表达在3种细胞中均无明显变化。结论：RXRα在提高SK-N-SH细胞生存能力中发挥重要作用。RXRα可以介导TRα和PPARα的表达，而BDE-47并未激活或者抑制SK-N-SH细胞TRβ和PPARγ的表达。说明BDE-47对于SK-N-SH细胞的毒性主要是通过激活RXRα，进一步诱导TRα和PPARα的表达而介导的。     

Biodistribution of the photosensitizer dihaematoporphyrin ether

Prior investigations describing the biodistribution of haematoporphyrin derivative (HpD) failed to substantiate a tumour-specific localization. Earlier optimism that dihaematoporphyrin ether (DHE), the active component of HpD, would demonstrate tumour specificity has also failed to be substantiated. The major sites of deposition for DHE are the same as those for HpD (liver, kidney and spleen) while the remaining organs show varying accumulation of DHE, depending on the dose given. Smaller doses of DHE, however, result in biodistribution patterns similar to those for HpD. The pharmacokinetics suggest that DHE binds to plasma proteins and, to some extent, to tissue. The optimal time for photodynamic therapy appears to be between 48 and 72 hours since the greatest mean tumour:muscle concentrations are found during this period.     

干／湿相转换法制备聚芳醚砜致密皮层不对称膜

以聚芳醚砜为膜材料，采用干／湿相转换法．在非挥发性溶剂－挥发性添加剂以及挥发性溶剂／共溶剂－弱挥发性添加剂两种溶剂体系中研究了致密皮层不对称膜的制备和形成条件，并对它们的结构及氮、氢气体透过性能进行了测试。结果表明，采用前一种溶剂体系。虽然可以在一定范围内控制膜平均孔径的变化，却难以得到致密皮层不对称膜。而后一种溶剂体系，在控制铸膜液组成、适当的制膜条件下可以得到具有海绵状支撑结构的不对称气体分离膜。     

Re-evaluation of the relationship between catechol-O-methyl transferase and the binding of norepinephrine to brown adipocyte membranes.

The binding of labeled norepinephrine to brown adipose tissue intact microsomes or solubilized microsomal proteins was studied in vitro.The effects of incubation in oxygenated Krebs-Ringer bicarbonate buffer, pH 7.4, on the physicochemical state of norepinephrine was investigated. After 10 minutes of incubation, the recovery of norepinephrine (0.5 μM) by alumina adsorption technique was found to be only about 40 per cent and no oxidation was detected by polarography. The recovery could be increased to over 90 per cent by adding metal chelators to the Krebs-Ringer bicarbonate buffer or by incubation in a phosphate buffer, which suggests that contaminating metals can cause considerable complexation of the hormone. The assays with unmodified norepinephrine were therefore performed under the following conditions: 10 min incubation in 50 mM phosphate buffer, pH 7.4. 25°.In both intact microsomes and solubilized microsmal proteins, the binding of norephinephrine was found to be sensitive to substances affecting catechol-O-methyl transferase activity such as tropolone, normeta nephrine, dithiothreitol, Ca²⁺ and Ca²⁺ chelators; agents that inhibited catechol-O-methly transferase activity were shown to stimulate norepinephrine binding and vice versa.After separation of solubilized microsomal proteins by Ultrogel AcA 34 filtration, both norepinephrine binding and catechol-O-methly transferase activity were found in the same protein fraction. Separation by polyacrylamide gel electrophoresis revealed congruent migration of norepinephrine binding, catechol-O-methyl transferase activity and S-adenosyl methionine binding.     

Superoxide scavenging activity and transferrin-ceruloplasmin antioxidant system in rat serum during chronic emotional-painful stress and dimethyl sulfoxide treatment

Institute of Higher Nervous Activity, Academy of Sciences of the USSR. Institute of Physicochemical Medicine, Ministry of Health of the RSFSR, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 106, No. 8, pp. 159–160, August, 1988.     

DMSO和As2O3对人食管癌细胞增殖的抑制作用

目的 抑制肿瘤细胞生长是治疗肿瘤的重要基础。本文比较二甲基亚砜（ＤＭＳＯ）、三氧化二砷（Ａｓ２Ｏ３）和维甲酸对人食管癌细胞生长抑制的影响。方法 用生长曲线、剂量－效应曲线、＾３Ｈ－ＴｄＲ掺入、ＭＴＴ比色分析、细胞周期的流式术检测、ＰＣＮＡ及Ｃｙｃｌｉｎ Ｄ１免疫组化等多项指标反映细胞增殖改变。结果 二甲基亚砜和三氧化二砷对食管癌细胞株生长的抑制作用较传统的维甲酸效果更强。结论 本文强烈提示二甲基亚     

2,6-二甲基-4-(2-氯苯基)-1,4-二氢-3,5-吡啶二羧酸二甲酯的抗5-羟色胺作用在防治野百合碱性大鼠肺动脉高压中的意义

采用免疫组化,图像分析,细胞培养和细胞内游离钙离子浓度（［Ｃａ２＋］ｉ）测定等方法研究２,６－二甲基－４－（２－氯苯基）－１,４－二氢－３,５－吡啶二羧酸二甲酯（ＤＣＤＤＰ）防治野百合碱（ＭＣＴ）所致肺动脉高压的作用机理．结果发现每天ｉｐＤＣＤＤＰ５－５００μｇ·ｋｇ－１１次,连续２８ｄ,能够明显地减少ＭＣＴ（６０ｍｇ·ｋｇ－１ｓｃ）引起的大鼠肺组织中５－ＨＴ相对含量及其受体阳性细胞数目增多,对５－ＨＴ引起的肺动脉平滑肌细胞增生,收缩及其［Ｃａ２＋］ｉ增高都有显著的抑制作用．结果提示,抑制肺组织中５－ＨＴ含量及其受体数目的增加,对抗５－ＨＴ引起的血管平滑肌细胞增生及收缩,可能是ＤＣＤＤＰ防治ＭＣＴ性肺动脉高压的重要机理之一．     

Laser-assisted fluorescence detection of plaque

Selective fluorescence-marking of plaque offers new possibilities in cardiovascular diagnosis and therapy. Angioscopic investigations and spectrometry-assisted laser angioplasty will be simplified and more effective as compared with methods of today. It might help to make laser angioplasty a further promising interventional method to overcome, at least partially, the problems caused by atheromatous or atherosclerotic changes in the cardiovascular system.Fluorescence detection and imaging of markers is usually limited by the intrinsic fluorescence of tissue. Optical differential methods in combination with two-wavelength laser excitation and computer-assisted image processing, however, allow for discrimination of background-related signals and enable plaque detection and imaging at a high contrast.Plaque consists of either fibrotic, lipoid, or calcified depositions and is rather bradytrophic. For that reason in vitro experiments on human specimens post mortem seem to be justified and of clinical evidence. Due to intrinsically different fluorometric properties of plaque and normal vascular tissue imaging of marker-free plaque areas is possible. Additionally the specimens have been incubated with a haematoporphyrin-containing fluorescence marker at concentrations of 10–40g ml^–1 and incubation times of 60 min in order to obtain a corresponding increase in contrast. Lipoid depositions show the highest contrast because of lipophilic properties of the marker, while fibrotic and calcified plaque is slightly less effectively marked. The results, however, so far obtained indicate that fluorescence detection of plaque promises further progress in diagnosis and therapy of cardiovascular diseases.