GC-MS分析法在人参有机氯农药残留检测中的应用

以丙酮－饱和氯化钠溶液－石油醚的一步法提取分离技术制备样品溶液,采用ＧＣ－ＭＳ分析方法对人参中有机氯农药残留进行了测定。加标人参样品的测定结果表明：两个水平加标回收率：０．１０ｍｇ／ｋｇ添加水平时,除ＰＣＮＢ平均回收率为５８．３％,其它组分的平均回收率为７６．０％～９０．１％,相对标准差为９．３％～１５．０％;０．０５０ｍｇ／ｋｇ添加水平时,平均回收率为６２．３％～８７．２％,相对标准差为６．０％～２２．５％。应用本方法测定人参中有机氯农药残留,基本上满足了灵敏、快速、准确可靠的分析方法要求     

韶关市麻疹减毒活疫苗初始强化免疫的效果分析

为探讨初始强化免疫对控制和消除麻疹的效果,１９９８ 年６ ～７ 月份对韶关市所有６ 月龄至１５ 岁人群实施ＭＶ 初始强化免疫后进行血清学检测和流行病学观察。结果强免后麻疹总抗体阳性率从９０－８ ％ 升至９９－５ ％ ,ＧＭＲＴ 从８６１－８ 增长到４６６０－２ ,低抗体率从３１－０ 降至１－８ ％ ,免疫成功率高达９８－９ ％ ;强免后（１９９８ 年７ ～１２ 月、１９９９ 年１ ～５ 月） 麻疹发病报告分别为２７ 例和１ 例,比强免前（１９９８ 年１ ～６ 月２５２ 例） 大幅度下降。说明ＭＶ 初始强化免疫控制麻疹效果显著,是控制和消除麻疹的可取策略。     

UV spectrometric and DC polarographic studies on apigenin and luteolin

Remarks on polyphenolic compounds has been arisen since past few years. The flavonoids appears to be the important groups of compounds with their capability to inhibit DNA damage, lipid peroxidation, to quench free radicals and, at least, anticarcinogenic and antiproliferative effects. On the other hand, their mechanism of action is still unexplained. Apigenin and luteolin are the most wide-spread flavones and they exhibited to be useful in chemoprevention. UV spectrometric and DC polarographic studies on these two compounds have been carried out with regard to changing pH. The most significant changes were observed at basic pH. These results could aid to elucidation of their mechanism of action as pH is one of the important factors for bioprocesses passing in living organisms.     

Purification and characterization of Moran 20K fromMorus alba

A new glycoprotein was purified from the aqueous methanolic extract of the root bark ofMorus alba which has been used as a component of antidiabetic remedy in Oriental Medicine. SDS-PAGE result shows that the molecular weight of the glycoprotein was approximately 20 kDa. This new glycoprotein was named as Moran 20K. The protein lowered blood glucose level in streptozotocin-induced hyperglycemic mice model and it also increased the glucose transport in cultured epididymis fat cells. The amino acid composition of the protein was analyzed, and the protein contained above 20% serine and cysteine such as insulin. The actual molecular weight of the protein was determined as 21,858 Da by MALDI-TOF mass spectroscopy.     

Specific staining of the axon membrane at nodes of Ranvier with ferric ion and ferrocyanide

Ferric ion and ferrocyanide were used as stains for light and electron microscopy of peripheral nerves. In rat sciatic nerves, it was found that ferric ion preferentially binds to the cytoplasmic surface of the axon membrane at nodes of Ranvier but not at internodal regions. In myelinated axons in the electric organ of the gymnotid fish, Sternarchus albifrons, the small excitable nodes are similarly stained, but the larger inexcitable nodes are not stained by ferric ion. Staining of the inner surface of the nodal membrane appears to be related to a structural specialization of this membrane, rather than accessibility to stain. Our data thus show a chemical differentiation of the inner surface of the axon membrane between nodes and internodes in normal peripheral nerve fibers and between the inner surface of the axon membrane at active nodes, inactive nodes, and the internodes in the Sternarchus electrocyte axons.     

Atomic absorption spectrometry in pharmaceutical analysis

A short review of the principles of atomic absorption spectrometry (AAS) — sources, atomizers, background correction, instrumentation, sample preparation, sensitivity, limit of detection, etc. — is given. The technique can be applied for impurity tests for trace metals as well as for assay of various commonly occurring elements in pharmaceuticals. The application of AAS in pharmaceutical analysis is illustrated with 17 examples.     

Biological monitoring of isocyanates and related amines

Summary Five men were exposed to toluene diisocyanate (TDI) atmospheres for 7.5 h. The TDI atmospheres were generated by a gas-phase permeation method, and the exposures were performed in an 8-m3 stainless-steel test chamber. The mean air concentration of TDI was ca. 40 g/m³, which corresponds to the threshold limit value (TLV) of Sweden. The inhaled doses of 2,4- and 2,6-TDI were ca. 120 g. TDI in the test chamber air was determined by an HPLC method using the 9-(N-methyl-aminomethyl)-anthracene reagent and by a continuous-monitoring filter-tape instrument. After hydrolysis of plasma and urine, the related amines, 2,4- and 2,6-toluenediamine 2,4-, and 2,6-TDA), were determined as pentafluoropropionic anhydride (PFPA) derivatives by capillary gas-chromatography using selected ion monitoring (SIM) in the electron-impact mode. The urinary elimination of the TDAs showed a possible biphasic pattern, with rapid first phases for 2,4-TDA (mean t _1/2 for the concentration in urine, 1.9 h) and for 2,6-TDA (mean t _1/2 for the concentration in urine, 1.6 h). The cumulative amount of 2,4-TDA excreted in urine within 28 h ranged from 8% to 14% of the estimated dose of 2,4-TDI, and the cumulative amount of 2,6-TDA in urine ranged from 14% to 18% of the 2,6-TDI dose. The average urinary level of 2,4-TDA was 5 g/l in the 6 to 8-h sample (range 2.8–9.6 g/l), and the corresponding value for 2,6-TDA was 8.6 g/l (range, 5.6–16.6 g/l). Biological monitoring of exposure to 2,4- and 2,6-TDI by analysis of 2,4- and 2,6-TDA in urine is feasible.     

In vitro and in vivo uptake of nickel sulfides by rat lymphocytes

The uptake, the biological transformation and the interaction with cellular constituents of Ni₃S₂ and NiS have been studied in vitro and in vivo on rat lymphocytes. NiS crystals are phagocytized in vitro and no structural degradation is observed within the first 3 days of exposure. Energy dispersive spectrometry (EDS) reveals a slight dissolution characterized by the loss of sulfur. Ni₃S₂ is degraded in the extracellular space to minute particles (50–100 nm) covering the cell membrane. Smaller intracellular particles (10–30 nm) are found selectively bound to mitochondria, endoplasmic reticulum, Golgi vesicles, nuclear membranes, and the euchromatinic part of nuclei. EDS analyses reveal that the particles bound to cell membranes and euchromatin no longer contain sulfur but phosphorus and nickel as inorganic compounds. This observation suggests the formation of a Ni/P complex with the phosphate groups either of membranous phospholipids or of nuclear RNA or DNA. A similar uptake and transformation process of Ni₃S₂ is observed on lymphocytes after in vivo incubation. This leads us to consider lymphocytes as target cells, as compared with other cell types where the Ni₃S₂ uptake occurs only partially. The present findings show a difference of uptake and biological transformation between Ni₃S₂ and NiS. The identical results obtained after in vitro and in vivo bioassays enhance the in vitro experiments, at least for this cell type.     

The Pharmacokinetics and Metabolism of Human Relaxins in Rhesus Monkeys

Two forms of chemically synthesized human relaxin (hRlx and hRlx-2) were administered as 88 µg/kg intravenous bolus doses to pregnant and nonpregnant rhesus monkeys. No significant differences in pharmacokinetics were observed between pregnant and nonpregnant animals for either form of relaxin; however, clearance of hRlx (3.1–3.4 ml/min/kg) was significantly slower than clearance of hRlx-2 (6.2–6.5 ml/min/kg) in both pregnant and nonpregnant animals. Although the terminal half-lives for hRlx and hRlx-2 were similar (148–157 min), the initial and steady-state volumes of distribution were somewhat larger for hRlx-2 (71–85 and 398–418 ml/kg, respectively) than for hRlx (61–65 and 294–319 ml/kg, respectively). The metabolism of hRlx-2 was also investigated in pregnant and non-pregnant rhesus monkeys after iv bolus (0.44 mg/kg) or 60-min infusion (1.1 mg/kg) administration. Fast atom bombardment mass spectral analysis of the relaxin immunoreactivity isolated from the plasma indicated that hRlx-2 was partially degraded by removal of amino acids from the C terminus of the B chain. The percentage of intact material declined over a 60-min time course. At 60 min post-dose, intact hRlx-2 was 46–64% of the detected material. Degraded forms representing loss of one and four amino acids (hRlx) from the C terminus of the B chain were 11–13 and 19–34% of the detectable material, respectively.     

The “Scandinavian Star” ferry disaster 1990 -a challenge to forensic odontology

Summary With 158 victims, the fire on board the Scandinavian Star was one of the world's worst ferry disasters. A team of identification experts, including dentists, were employed to secure evidence for identification and to remove the victims from the ferry. Four parallel teams, each with 2 dentists, examined and autopsied the victims at the Institute of Forensic Medicine, University of Oslo. Using the INTERPOL Disaster Victim Identification forms and aided by computers, all victims were identified within 17 days. Dental identity could be established in 107 cases (68%).