The cystathionine beta-synthase variant c.844_845ins68 protects against CNS demyelination in X-linked adrenoleukodystrophy

The clinical course of X-linked adrenoleukodystrophy (X-ALD) is of unexplained heterogeneity. Major X-ALD phenotypes are the progressive childhood cerebral form (CCALD) with early confluent cerebral demyelination and the adult-onset adrenomyeloneuropathy (AMN). Adult AMN may present with demyelinated foci of the CNS (adrenoleukomyeloneuropathy, ALMN) or without ("pure" AMN). Activated methionine is essential for CNS myelination, and methionine metabolism is important for glutathione synthesis, which may influence neurodegeneration. Cystathionine beta-synthase (CBS) is a key enzyme of methionine metabolism. The CBS variant c.844_845ins68 (p.-) may influence the availability of activated methionine as well as of glutathione. In this study, we analyzed this variant in genomic DNA samples of 86 X-ALD patients. We observed the allele carrying the insertion in 12 of 49 patients without CNS demyelination ("pure" AMN), but in none of the 37 patients with CNS demyelination (CCALD or ALMN; chi(2)=10.531; p=0.001). We conclude that the insertion allele of CBS c.844_845ins68 protected X-ALD patients against CNS demyelination in our study sample. These data suggest that the individual conditions in methionine metabolism may be a disease modifier of X-ALD. Since methionine metabolism can easily be influenced by vitamin and amino acid substitution, this observation could be a basis of novel treatment strategies in this yet untreatable disease. (c) 2006 Wiley-Liss, Inc.     

[35S]methionine interaction with rat liver tRNA and effect of chemical carcinogens

The interaction of [³⁵S]methionine with hepatic tRNA in normal, carcinogen-treated, and partially hepatectomized rats was studied. tRNA was preferentially labeled following [³⁵S]methionine (1.6 mCi, 25 mg/kg body wt) administration by intraperitoneal injection. The extent of [³⁵S]methionine-tRNA interaction was impaired by partial hepatectomy and by conditions having a carcinogenic potential.Presented at the Proceedings of the International Meetings on Normal and Neoplastic Growth in Hepatology, Bari, Italy, June 1989.Supported by CNR, Progetti Finalizzati Chimica Fine ed Oncologia     

药物性胆汁淤积型肝病的治疗研究

目的探讨药物性胆汁淤积型肝病的有效治疗方案。方法 217例患者符合药物性胆汁淤积型肝损害的诊断标准。分为SAM+H+UDCA组、SAM+H组、SAM+UDCA组、H+UDCA组、中药组。观察各组患者治疗前及治疗4周后的临床症状、体征,检测血清碱性磷酸酶(ALP)、转氨酶(AST、ALT)、总胆红素(TBil)、r-谷氨酰转肽酶(r-GT)、胆碱酯酶(CHE)等生化指标。采用配对设计t检验方法进行统计学分析。结果疗程满4周后,各组临床症状有明显改善,尤其是瘙痒症状评分明显下降。治疗后,各组主要生化指标血清TBil、ALT、AST、ALP、r-GT均下降,CHE升高。其中以血清TBil下降明显,差异有统计学意义(P0.05)。SAM+H+UDCA组和SAM+H组较其他治疗组总胆红素下降速度快、幅度大。但两组之间治疗后TBil水平差异无统计学意义(P0.05);加用激素组随治疗时间延长,使用激素的副作用发生率增加。结论腺苷蛋氨酸与激素联合应用是治疗药物性胆汁淤积型肝病的较好方法,但需注意激素引起的不良反应。     

HPLC柱前衍生法测定舒血宁注射液中四种氨酸的含量

[目的]建立舒血宁注射液中4种氨基酸(天门冬氨酸、苏氨酸、丙氨酸、甲硫氨酸)的高效液相色谱(HPLC)柱前衍生化法,为舒血宁注射液的质量控制提供方法。[方法]以异硫氰酸苯酯(PITC)为柱前衍生化试剂,采用C18色谱柱,乙腈-水(5∶1)-乙酸铵缓冲溶液(p H 6.5)为流动相,梯度洗脱,检测波长为254 nm,测定舒血宁注射液中天门冬氨酸、苏氨酸、丙氨酸、甲硫氨酸的含量。[结果]4种氨基酸的分离及线性关系良好,精密度,重复性,稳定性RSD均都小于5%,平均回收率在95.6%~98.9%之间且RSD小于5%。舒血宁注射液中4种氨基酸总含量为1 738.47μg/mL。其中甲硫氨酸含量最高,丙氨酸的含量最低。[结论]本方法简便、准确、可靠,适用于舒血宁注射液中氨基酸含量的测定。     

Electron microscopic localization of enkephalin in the median eminence and the adenohypophysis of the guinea-pig

By using different immunocytochemical methods, it has been possible to define the ultrastructural localization of enkephalins in the median eminence and in the adenohypophysis of the guinea-pig. In the median eminence the staining was essentially confined to the granules of nerve terminals in the palissade zone. When the immunocytochemical procedure occurred before embedding the tissue, the granules displayed several electron-dense dots revealing the presence of enkephalin. In addition this technique made it possible to observe a peripheral staining of the small vesicles. In the adenohypophysis three cell types bound antisera to leucine or methionine-enkephalins: the gonadogrophs, the thyrotrophs and the corticotrophs. In all three cases the reaction product was obtained on the granules.It is proposed that enkephalins might act on the pituitary secretions not only at the hypothalamic level but also at the pituitary level.     

Dimethyl sulfone in human cerebrospinal fluid and blood plasma confirmed by one-dimensional (1)H and two-dimensional (1)H-(13)C NMR

(1)H-NMR spectroscopy at 500 MHz was used to confirm that a previously unidentified singlet resonance at 3.14 ppm in the spectra of cerebrospinal fluid and plasma samples corresponds to dimethyl sulfone (DMSO(2)). A triple resonance inverse cryogenic NMR probe, with pre-amplifier and the RF-coils cooled to low temperature, was used to obtain an (1)H-(13)C HSQC spectrum of CSF containing 8 microM (753 ng/ml) DMSO(2). The (1)H-(13)C correlation signal for DMSO(2) was assigned by comparison with the spectrum from an authentic reference sample. In plasma and CSF from healthy controls, the concentration of DMSO(2) ranged between 0 and 25 micromol/l. The concentration of DMSO(2) in plasma from three of four patients with severe methionine adenosyltransferase I/III (MAT I/III) deficiency was about twice the maximum observed for controls. Thus, DMSO(2) occurs as a regular metabolite at low micromolar concentrations in cerebrospinal fluid and plasma. It derives from dietary sources, from intestinal bacterial metabolism and from human endogenous methanethiol metabolism.     

Subhepatotoxic exposure to arsenic enhances lipopolysaccharide-induced liver injury in mice

Exposure to arsenic via drinking water is a serious health concern in the US. Whereas studies have identified arsenic alone as an independent risk factor for liver disease, concentrations of arsenic required to damage this organ are generally higher than found in the US water supply. The purpose of the current study was to test the hypothesis that arsenic (at subhepatotoxic doses) may also sensitize the liver to a second hepatotoxin. To test this hypothesis, the effect of chronic exposure to arsenic on liver damage caused by acute lipopolysaccharide (LPS) was determined in mice. Male C57Bl/6J mice (4-6 weeks) were exposed to arsenic (49 ppm as sodium arsenite in drinking water). After 7 months of exposure, animals were injected with LPS (10 mg/kg i.p.) and sacrificed 24 h later. Arsenic alone caused no overt hepatotoxicity, as determined by plasma enzymes and histology. In contrast, arsenic exposure dramatically enhanced liver damage caused by LPS, increasing the number and size of necroinflammatory foci. This effect of arsenic was coupled with increases in indices of oxidative stress (4-HNE adducts, depletion of GSH and methionine pools). The number of apoptotic (TUNEL) hepatocytes was similar in the LPS and arsenic/LPS groups. In contrast, arsenic pre-exposure blunted the increase in proliferating (PCNA) hepatocytes caused by LPS; this change in the balance between cell death and proliferation was coupled with a robust loss of liver weight in the arsenic/LPS compared to the LPS alone group. The impairment of proliferation after LPS caused by arsenic was also coupled with alterations in the expression of key mediators of cell cycle progression (p27, p21, CDK6 and Cyclin D1). Taken together, these results suggest that arsenic, at doses that are not overtly hepatotoxic per se, significantly enhances LPS-induced liver injury. These results further suggest that arsenic levels in the drinking water may be a risk modifier for the development of chronic liver diseases.     

Maternal nutrient intake and fetal gastroschisis: A case‐control study

Fetal gastroschisis is a paraumbilical abdominal wall defect with herniation of the abdominal organs. This multifactorial malformation occurs in young pregnant women, and the underlying cause of the disease remains unknown; however, nutritional factors may play a role in its development. This case‐control study explored the association of maternal nutrient intake with the occurrence of gastroschisis. The gastroschisis group (GG) comprised 57 pregnant women with fetuses with gastroschisis, and the control group (CG) comprised 114 pregnant women with normal fetuses matched for maternal age, gestational age, and preconception body mass index classification. Nutritional assessments related to the preconception period were obtained using the food consumption frequency questionnaire, and nutrient intakes were calculated using nutrition programs. The median daily calorie intake was higher (2,382.43 vs. 2,198.81; p = .041) in the GG than in the CG. The median intake of methionine (763.89 vs. 906.34; p = .036) and threonine (1,248.34 vs. 1,437.01; p = .018) was lower in the GG than in the CG. Pregnant women with fetuses with gastroschisis have a diet characterized by higher calorie intake and lower levels of essential amino acids (methionine and threonine) during the preconception period than pregnant women with normal fetuses.