Congenital cardiac malformations in Adams-Oliver syndrome

Whole genomic hprt clones were used in Southern analysis to screen the integrity of the hprt gene in a family that includes a patient with HPRT enzyme deficiency causal to Lesch-Nyhan syndrome. A 5 kb DNA sequence deletion was found to have its endpoints in the first and third introns. The probes identified the carrier status of female family members, aided by an RFLP carried by the mother's normal X-chromosome.     

1-Methylnicotinamide stimulates cell growth and inhibits hemoglobin synthesis in differentiating murine erythroleukemia cells

Exposure of murine erythroleukemia cells (MELCs) to nicotinamide (NA) or its synthetic analog N′-methylnicotinamide (N′-MN) reduces cell growth and induces terminal differentiation, marked by increased heme and globin accumulation. On the contrary, 1-methylnicotinamide (1-MN), the primary metabolite of excess NA, was found to stimulate cell growth and reduce spontaneous differentiation of cultured MELCs. Log phase MELCs exhibited up to 50% higher cell density above untreated cells when cultured for up to 96 h with 2.5 mM 1-MN. When combined with NA or several chemically-unrelated inducers of hemoglobin synthesis in cultured MELCs, 1-MN reduced the globin mRNA levels and heme accumulation by 40–80%. 1-MN was able to inhibit heme production if present during only the first 24–48 h after NA exposure. Pre-treatment with 1-MN could not confer resistance of cells to effects of NA, suggesting the inhibition is reversible. Commitment to differentiate in semisolid medium by the most potent inducer, 5 mM N′-MN, was inhibited up to 95% by 2.5 mM concentrations of 1-MN. It appears that 1-MN has opposing effects on growth and induction of differentiation than those seen in MELC cultures exposed to NA or N′-MN.     

RP－HPLC法测定复合维生素B片中维生素B_1、B_2、B_6和烟酰胺的含量

用ＲＰ－ＨＰＬＣ法（固定相为μＢｏｎｄｐａｋ Ｃ１８柱，流动相为己烷磺酸钠冰醋酸液，紫外检测波长为２８０ｎｍ）同时测定出复合维生素Ｂ片中四个组分的含量，方法专属性强，省时；维生素Ｂ１、Ｂ２、Ｂ６和烟酰胺的平均回收率和平均相对标准偏差分别为１００．５％，２．０％；９８．０％，１．９％；１０１．８％，１．１％；１００．１％，２．１％（ｎ＝３）。     

The coenzyme nicotinamide adenine dinucleotide (NADH) improves the disability of Parkinsonian patients

Summary The coenzyme nicotinamide adenine dinucleotide (NADH) has been used in an open label trial as novel medication in 34 patients with Parkinson's disease, using an intravenous administration technique. In all patients a beneficial clinical effect was observed. 21 patients (61.7%) showed a very good (better than 30%) improvement of disability, 13 patients (38.3%) a moderate (up to 30%) improvement. Concomitant with the improvement of the disability the urine level of homovanillic acid (HVA) increased significantly in all patients (in some patients by more than a 100%). The daily on phases of the patients could be increased from 2 up to 9 hours in the individual patients by NADH administration.     

Biochemical characterization of I-Ak proteins from mutant antigen-presenting B-cell--B-lymphoma hybridomas

Chemically induced mutants of an I-Ak,d expressing antigen-presenting B-cell--B-lymphoma hybridoma have recently been generated by immunoselection in vitro and were found to possess alterations in some of their serologically and functionally defined I-Ak region dependent functions. In order to identify at the structural level the origin of the differences in serological and functional properties of these mutants, I-Ak molecules from several of these mutant hybridomas were compared biochemically to wild-type I-Ak polypeptides by two-dimensional gel electrophoresis and high-pressure liquid chromatographic tryptic peptide analyses. Two-dimensional gel electrophoresis indicated that no major structural alterations, resulting in changes in mol. wt or charge, had occurred in the Ak alpha or Ak beta polypeptides from the mutant cells. Likewise, Ak alpha peptide maps of the mutants were indistinguishable from the normal Ak alpha peptide maps. However, two of the three mutants studied did exhibit one additional peptide in their Ak beta peptide maps. These results suggest that the major deficiencies in T-cell-activating functions of these mutants are a result of a limited alteration in the Ak beta polypeptide primary structure.     

NAD-Sepharose 6MB亲和胶的制备及在2,5-二酮基-D-葡萄糖酸还原酶纯化中的应用

目的制备NAD亲和胶,用于分离纯化2,5-二酮基-D-葡萄糖酸还原酶。方法将NAD通过丁二酸二酰肼与溴化氰活化的Sepharose6MB胶联结,制得NAD亲和胶。从棒杆菌细胞中提取的2,5-二酮基-D-葡萄糖酸还原酶粗酶液用NAD亲和胶进行亲和层析纯化。结果NAD的结合率为71．67％;亲和层析回收率为77．27％;酶的比活提高了1．1倍。结论以NAD为配基的亲和胶用于纯化以NADPH为辅酶的2,5-DKG还原酶行之有效。     

HPLC法测定烟酰胺片的含量

建立烟酰胺片含量的HPLC测定方法。色谱柱为KF -C18柱 ;流动相为乙腈 -三乙胺溶液 (0 0 2 5mol·L-1,用磷酸调节pH至 3 0 ) (8∶92 ) ,流速为 1 0ml·min-1;检测波长 2 6 1nm ;吡嗪酰胺为内标物。烟酰胺在 8～ 5 6 μg·ml-1范围内呈良好的线性关系 ,平均回收率为 99 4 7% ,RSD =0 4 2 % (n =9)。方法简便 ,可靠 ,快速 ,准确 ,可用于测定烟酰胺片的含量。     

吗啡对PC12细胞嘌呤核苷酸代谢相关酶基因表达的影响

目的：研究吗啡对神经细胞模型PC12嘌呤核苷酸补救合成酶与分解代谢关键酶基因表达的影响。方法：采用逆转录聚合酶链反应（RT-PCR）方法检测暴露于吗啡不同时间的PC12细胞次黄嘌呤-鸟嘌呤磷酸核糖转移酶（HGPRT）、腺苷激酶（AK）和腺苷脱氨酶（AD A）mRNA的表达水平。结果：与相应时段对照组相比，PC12细胞暴露于吗啡12及24 h时，HGPRT mRNA水平均明显增高(P<0.05)，作用48 h时HGPRT mRNA水平显著降低(P<0.05)，72 h后HGPRT mRNA水平再次升高(P<0.05)；吗啡处理的PC12细胞于12和24 h时，AK mRNA水平均明显降低(P<0.05)，作用48 h时AK mRNA水平升高(P<0.05)，72 h后AK mRNA水平恢复正常；ADA mRNA水平均表现为轻度降低，12 h差异有显著性(P<0.05)。结论：吗啡影响神经细胞嘌呤核 苷酸代谢，使细胞内腺苷酸及腺苷水平增高，这可能是吗啡依赖和耐受形成的机理之一 。     

高效液相色谱法测定六合维生素丸中3种B族维生素含量

目的:采用离子对反相高效液相色谱法测定六合维生素丸中烟酰胺、维生素B2、维生素B13种水溶性维生素的含量。方法:以C18为色谱柱,0.005mol/L庚烷磺酸钠溶液(含0.5%冰醋酸和0.05%三乙胺)-甲醇(72∶28)为流动相,流速为1ml/min,检测波长为260nm。结果:烟酰胺、维生素B2、维生素B1的线性范围分别为0.3154～15.7700μg、0.05227～2.6135μg、0.4474～22.3700μg;方法的回收率在97.5%～99.2%,RSD为1.3%～1.8%。结论:本法简便,快速,为六合维生素丸产品的质量控制及多维类药物中水溶性维生素含量的测定提供了可靠依据。