血小板α颗粒膜蛋白140检测在“病”与“证的”特异性联系

应用血小板α颗粒膜蛋白１４０（ＧＭＰˉ１４０）为血小板活化指标，测定了７４例糖尿病、３６例心血管疾病、５３例肾脏疾病患者的血浆ＧＭＰˉ１４０浓度，并分别按病种及按是否有血瘀证分组比较了各组间的ＧＭＰˉ１４０测定值。结果表明：ＧＭＰˉ１４０在各疾病组患者均较正常人升高，三组间则无明显差异；而在血瘀及非血瘀证明之间则有明显差异。认为ＧＭＰˉ１４０有可能作为诊断血瘀证的一项实验室指标。     

杀莠素A对兔软骨细胞增殖和产生NO的影响

研究杀莠素Ａ对ＩＬ－１抑制软骨细胞增殖和诱导ＮＯ产生的作用。方法：ＩＬ－１单独或与杀莠素Ａ共育于软骨细胞,用结晶紫染色法测定软骨细胞增殖,Ｇｒｉｅｓｓ法测定ＮＯ的产生。结果：ＩＬ－１抑制软骨细胞增殖,杀莠素Ａ剂量依赖地逆转ＩＬ－１的作用。杀莠素Ａ还能剂量依赖地抑制ＩＬ－１诱导软骨细胞产生ＮＯ。结论：杀莠素Ａ逆转ＩＬ－１换制软骨细胞增殖的作用可能是通过ＮＯ介导的。     

Retinol status of newborn infants with congenital diaphragmatic hernia

The etiology of congenital diaphragmatic hernia (CDH) is not yet known. Studies in the literature from 1941 have reported that nutritional deficiency of vitamin A during pregnancy could lead to CDH, associated or not with other malformations in young rats. More recently, possible correlations between expression patterns of cellular retinoid-binding protein and retinoic-acid receptors and morphologic effects of vitamin A deficiency have been suggested. The purpose of this study was to verify in human newborns the possible link between vitamin A deficiency and CDH previously observed in experimental animals. Blood samples were obtained during the first hours after birth from 11 term CDH newborns and 11 healthy controls matched for gestational age, and also from 7 mothers in each group, for a total of 7 newborn-mother pairs of matched CDH-controls. Plasma retinol was measured by high-performance liquid chromatography and retinol-binding protein (RBP) by nephelometry. In the 11 matched CDH-control newborns, plasma retinol and RBP levels in CDH newborns were 50% less than control values (P< 0.0002 and <0.006, respectively); in contrast, retinol levels in CDH mothers were significantly higher than those of control mothers (P < 0.005). The observation that the plasma concentrations of retinol and RBP are low in infants with CDH relative to controls may be clinically very relevant and may help to elucidate the mechanism of development of this congenital anomaly.     

Evaluation of the MTHFR C677T allele and the MTHFR gene locus in a German spina bifida population

A number of recent studies have demonstrated that the occurrence and recurrence risk of neural tube defects (NTD) is reduced by folic acid supplementation before and during pregnancy. Epidemiological studies have shown low plasma folate and raised plasma homocysteine in women with spina bifida aperta (SB) children suggesting an abnormal folate metabolism. The 5,10-methylenetetrahydrofolate reductase (MTHFR) variant C677T, resulting in a decreased activity of the enzyme, has been associated with the development of NTD. Several studies demonstrated that homozygosity for the C677T mutation occurs at a higher frequency in patients with SB phenotype than in control individuals. The SB risk is strongest if both the mother and her child have the mutation in the homozygous state. In the present study we compared the frequency of the C- and T-alleles in healthy German individuals (n=153) with German SB patients (n=137). Our study groups reveal no significant difference in C/T-allele frequencies and genotype distributions. A family based association study, the transmission disequilibrium test, confirms the absence of an association between T-allele and SB. In 9 of 40 families we were able to exclude linkage to the MTHFR locus (1p36.3) employing different inheritance models. Conclusion Our data show no evidence for an association between the C677T mutation and the occurrence of the SB phenotype. Therefore we cannot support the hypothesis that the MTHFR variant does account for a significant genetic predisposition to the SB phenotype in the studied German patients. Received: 11 June 1997 / Accepted in revised form: 3 November 1997     

Role of Sialylglycoconjugate(s) in the Initial Phase of Metastasis of Liver-metastatic RAW117 Lymphoma Cells

To elucidate the early events of blood-borne metastasis under actual blood flow, real-time trafficking of RAW117 large cell lymphoma cells, namely parental RAW117-P and liver-metastatic RAW117-H10 cells, was investigated using positron emission tomography (PET). Both types of cells accumulated in the liver immediately after injection via the portal vein, and were eliminated from the liver time-dependently. The elimination rate of RAW117-H10 cells, however, was slower than that of RAW117-P cells, suggesting that RAW117-H10 cells interact more strongly with hepatic sinusoidal endothelium than the parental cells. This result correlated with the metastatic potential of these cells: RAW117-H10 cells metastasized in the liver to a greater extent than RAW117-P cells after injection via this route. To investigate the role of sialylglycoconjugates in the interaction of RAW117-H10 cells with the hepatic endothelium after injection via the portal vein, the trafficking of RAW117-H10 cells was examined after the cells had been treated with sialidase. The elimination rate of RAW117-H10 cells from liver was observed to be greatly accelerated by sialidase treatment. To elucidate what kind of sialylglycoconjugates is related to this phenomenon, we analyzed the distribution of sialyl Lewis A and sialyl Lewis X antigens of both sublines of RAW117 by using flow cytometry. RAW117-H10 cells were found to express a much higher level of sialyl Lewis A than RAW117-P cells, whereas the amount of sialyl Lewis X did not differ significantly. These findings suggest that some sialylglycoconjugates, perhaps sialyl Lewis A in particular, play an important role in the initial interaction of RAW117-H10 cells with the hepatic endothelium, leading to metastasis.     

Outbreak of nosocomialAcinetobacter baumannii bacteremia in a high risk ward

Acinetobacter baumannii is emerging as a major cause of nosocomial infections particularly in high risk patients. Being resistant to adverse environmental conditions, it can stay for prolonged periods in the hospital environment. We report an outbreak in the medical oncology ward where nine patients suspected of bacteraemia were blood culture positive forA. baumannii from the two samples each, one collected through the i.v. cannula and another through the peripheral venous puncture. The bacteria was also isolated from the environmental sources from the various samples collected. The biotype, antibiogram, cellular protein profiles on SDS-PAGE and the restriction enzyme analysis patterns of the patient isolates and the environmental isolates were similar. This points to the environment as a source of infection. With reinforcement of proper barrier nursing and use of disposable heparine ampoules it was possible to control the outbreak.     

Preclinical pharmacology of the natural product anticancer agent 10-hydroxycamptothecin, an inhibitor of topoisomerase I

Purpose: 10-Hydroxycamptothecin (HCPT) is an indole alkaloid isolated from a Chinese tree, Camptotheca acuminata, and has a wide spectrum of anticancer activity in vitro and in vivo mainly through inhibitory effects on topoisomerase I. HCPT has been shown to be more potent and less toxic than camptothecin and has recently undergone clinical trials. To determine how HCPT might be best used as an anticancer agent, preclinical studies of the pharmacokinetics, tissue distribution, metabolism and elimination of HCPT in rats were undertaken. Methods: HCPT was administered to rats by i.v. bolus injection at doses of 1, 3, and 10 mg/kg body weight. HCPT (lactone and carboxylate) and its metabolites in plasma, urine, feces, and various tissues were quantitated by reversed-phase HPLC. Pharmacokinetic parameters were then estimated. Results: Following i.v. administration at doses of 3 or 10 mg/kg, the plasma concentration-time profile for lactone HCPT could be best described by a three-compartment model, with terminal elimination half-lives of 140.4 and 428.6 min, respectively. A two-compartment model was used to fit the plasma concentration-time curve at 1 mg/kg, with a terminal elimination half-life of 30.5 min. Carboxylate HCPT had a longer half-life than the lactone form of HCPT. During the initial 6 h after dosing, urinary excretion was the major route of elimination, and fecal excretion became the major route of elimination thereafter. HCPT was widely distributed to various tissues including the enterohepatic system, kidney, and bone marrow. The lactone form of HCPT was detectable in various tissues examined up to 72 h after dosing at all the three test doses. HCPT glucuronides were present in plasma, urine, feces and various tissues. No significant toxicity was observed at doses of 1 or 3 mg/kg. Polyuria and hematuria were observed only during the initial 3 h after dosing at 10 mg/kg. Conclusions: Prolonged elimination of HCPT in vivo may have a significant impact on its therapeutic effects. HCPT is metabolized to its carboxylate form and glucuronides. Dose-dependent toxicity was observed with i.v. administration of HCPT. The results of this study should be useful in the design of future human trials with this anticancer drug. Received: 6 September 1996 / Accepted: 15 July 1997     

Quantitation of dolastatin-10 using HPLC/electrospray ionization mass spectrometry: application in a phase I clinical trial

A highly sensitive and specific assay for the quantitation of the anticancer agent dolastatin-10 (DOL-10) in human plasma is described. The method was based on the use of electrospray ionization-high-performance liquid chromatography/mass spectrometry (ESP-LC/MS). The analytical procedure involved extraction of plasma samples containing DOL-10 and the internal standard (DOL-15) with n-butyl chloride, which was then evaporated under nitrogen. The residue was dissolved in 50 μl mobile phase and 10 μl was subjected to ESP-LC/MS analysis using a C₁₈ microbore column. A linear gradient using water/acetonitrile was used to keep the retention times of the analytes of interest under 5 min. The method exhibited a linear range from 0.005 to 50 ng/ml with a lower limit of quantitation (LLQ) at 0.005 ng/ml. Absolute recoveries of extracted samples in the 85–90% range were obtained. The method's accuracy (≤5% relative error) and precision (≤10% CV) were well within industry standards. The analytical procedure was applied to extract DOL-10 metabolites from samples obtained following incubation of the drug with an activated S9 rat liver preparation. Two metabolic products were detected and were tentatively identified as a N-demethyl-DOL-10 and hydroxy-DOL-10. Structural assignments were made based on the fragmentation patterns obtained using the electrospray source to produce collision-induced dissociation (CID). The method was also applied to the measurement of DOL-10 in the plasma of patients treated with this drug. Preliminary investigation of the pharmacokinetics suggested that drug distribution and elimination may be best described by a three-compartment model with t_1/2α = 0.087 h, t_1/2β = 0.69 h and t_1/2γ = 8.0 h. Plasma clearance was 3.7 l/h per m². Received: 17 March 1997 / Accepted: 13 June 1997     

Somatic Mutations of the PTEN/MMAC1 Gene in Fifteen Japanese Endometrial Cancers: Evidence for Inactivation of Both Alleles

Loss of heterozygosity (LOH) of chromosome 10q is observed in approximately 40% of endometrial cancers. Mutations in PTEN/MMAC1 , a gene recently isolated from the 10q23 region, are responsible for two dominantly inherited neoplastic syndromes, Cowden disease and Bannayan-Zonana syndrome. Somatic mutations of this gene have also been detected in sporadic cancers of the brain, prostate and breast. To investigate the potential role of this putative tumor suppressor gene in endometrial carcinogenesis as well, we examined 46 primary endometrial cancers for LOH at the 10q23 region, and for mutations in the entire coding region and exon-intron boundaries of the PTEN/MMAC1 gene. LOH was identified in half of the 38 informative cases, and subtle somatic mutations were detected in 15 tumors (33%). Our results suggest that of the genes studied so far in endometrial carcinomas, PTEN/MMAC1 is the most commonly mutated one, and that inactivation of both copies by allelic loss and/or mutation, a pattern that defines genes as "tumor suppressors,'contributes to tumorigenesis in endometrial cancers.