Analysis of glutathione peroxidase 1 gene polymorphism and Keshan disease in Heilongjiang Province, China.

Keshan disease (KD) is an endemic cardiomyopathy associated with selenium deficiency. Recent studies indicate that glutathione peroxidase 1 (GPx1) mutation decreases GPx activity in myocardial cells and increases the risk of KD. To further clarify the correlation between GPx1 polymorphism and KD, we analyzed GPx1 polymorphism, blood selenium levels and GPx activity in KD patients and healthy controls in Heilongjiang Province. Four and 24 new mutation loci in the promoter and the exon region, respectively, of the GPx1 gene were found in the subjects, in contrast with the previously reported loci. There were no significant differences in the mutation frequency of these loci between the KD group and controls (chi-square test; P > 0.05). However, the mutation frequency of exon 474 was higher in the KD group (7/36) than in controls (2/41), and GPx activity was lower in the mutation group (90.475 ± 23.757 U/L) than in the non-mutation group (93.947 ± 17.463 U/L). Further investigation is necessary to clarify a possible causality between GPx1 exon 474 mutation and KD.

Effect of low power laser irradiation on disconnecting the membrane-attached hemoglobin from erythrocyte membrane.

In our previous study we found that low power laser irradiation improved the erythrocyte deformability, but the mechanism is unclear. The membrane-attached hemoglobin (Hbm) may be one of the determining factors for the erythrocyte deformability. We report here for the first time, that laser irradiation can reduce the Hbm contents in pig's erythrocytes, providing the explanation for the improvement of erythrocyte deformability. The decrease of the Hbm was proportional to the irradiation dose, but the relative change of Hbm was saturated around 35%. The 532 nm laser was more efficient at lowering Hbm than the 632.8 nm laser, consistent with the absorption spectrum of Hbm.

[Chemical constituents of Phyllanthus urinaria L. and its antiviral activity against hepatitis B virus].

Studies on the chemical constituents of Phyllanthus urinaria and its antiviral activity against hepatitis B virus were completed. Eleven compounds have been isolated. Two of them are new compounds methyl ester dehydrochebulic acid and methyl brevifolin carboxylate. Antiviral experiments on HBsAg in vitro and liver damage caused by CCl4 have shown that. Phyllanthus urinaria possesses antiviral activities against HBV.

D2 dopamine receptor antisense increases the activity and mRNA of tyrosine hydroxylase and aromatic L-amino acid decarboxylase in mouse brain.

A D2 dopamine receptor antisense oligodeoxynucleotide was administered intracerebrovetricularly to mice twice on the first day and then once daily for 2 days. The animals were killed 2 h after the last injection, and tyrosine hydroxylase and aromatic L-amino acid decarboxylase activities assayed in the corpus striatum, olfactory tubercle and frontal cortex. Tyrosine hydroxylase activity increased in corpus striatum but not in the olfactory tubercle or in the frontal cortex, while the activity of aromatic L-amino acid decarboxylase increased in all three brain regions. The treatment with the antisense oligomer also elevated the mRNA levels for the two enzymes in the midbrain. In contrast, repeated injection of a vehicle or a random oligomer was without effect on enzyme activity or mRNA D2 antisense oligodeoxynucleotides appear to be selective tools to investigate the role of D2 dopamine receptors in brain.

Impaired recovery of alpha 1- and alpha 2-adrenergic receptors in brain tissue of aged rats.

The influence of age on the rate of recovery of alpha 1- and alpha 2-adrenergic receptors was determined in rat brain following their irreversible inhibition by phenoxybenzamine (PBZ). Fischer 344 rats (3- or 24-months old) were administered two doses of vehicle or PBZ at 12-hour intervals. At various times after the last dose of PBZ, alpha-adrenergic receptors were quantified in washed membranes of cerebral cortex and hypothalamus, using [3H]prazosin and [3H]rauwolscine to label alpha 1- and alpha 2-adrenergic receptors, respectively. Recovery of prazosin binding sites in cortex and hypothalamus and of rauwolscine binding sites in cortex was significantly delayed in aged versus young rats. Administration of [3H]PBZ to young and aged rats revealed no apparent differences in the concentration or rate of disappearance of PBZ or its metabolites that could account for these age-related changes. These data suggest that the synthesis of both alpha 1- and alpha 2-adrenergic receptors is impaired in brain tissue from aged rats.