Mechanisms of phytoestrogen biochanin A-induced vasorelaxation in renovascular hypertensive rats

Background

The plant-derived estrogen biochanin A is known to cause vasodilation, but its mechanism of action in hypertension remains unclear. This study was undertaken to investigate the effects and mechanisms of biochanin A on the thoracic aorta in two-kidney, one clip (2K1C) renovascular hypertensive rats.

Methods

Hypertension was induced by clipping the left renal artery, and control age-matched rats were sham treated. Thoracic aortae were mounted in tissue baths to measure isometric tension.

Results

Biochanin A caused concentration-dependent relaxation in aortic rings from 2K1C hypertensive and sham-treated rats, which was greater in 2K1C rats than in sham rats. Biochanin A-induced relaxation was significantly attenuated by removing the endothelium in aortic rings from 2K1C rats, but not in sham rats. N^ω-Nitro-l-arginine methyl ester, a nitric oxide synthase inhibitor, or indomethacin, a cyclooxygenase inhibitor, did not affect the biochanin A-induced relaxation in aortic rings from 2K1C and sham rats. By contrast, treatment with glibenclamide, a selective inhibitor of adenosine triphosphate-sensitive K⁺ channels, or tetraethylammonium, an inhibitor of Ca²⁺-activated K⁺ channels, significantly reduced biochanin A-induced relaxation in aortic rings from both groups. However, 4-aminopyridine, a selective inhibitor of voltage-dependent K⁺ channels, inhibited the relaxation induced by biochanin A in 2K1C rats, whereas no significant differences were observed in sham rats.

Conclusion

These results suggest that the enhanced relaxation caused by biochanin A in aortic rings from hypertensive rats is endothelium dependent. Vascular smooth muscle K⁺ channels may be involved in biochanin A-induced relaxation in aortae from hypertensive and normotensive rats. In addition, an endothelium-derived activation of voltage-dependent K⁺ channels contributes, at least in part, to the relaxant effect of biochanin A in renovascular hypertension.

Pathogen inactivation efficacy of Mirasol PRT System and Intercept Blood System for non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma

BACKGROUND AND OBJECTIVES

This study was conducted to evaluate the efficacy of pathogen inactivation (PI) in non-leucoreduced platelet-rich plasma-derived platelets suspended in plasma using the Mirasol PRT System and the Intercept Blood System.

METHODS

Platelets were pooled using the Acrodose PL system and separated into two aliquots for Mirasol and Intercept treatment. Four replicates of each viral strain were used for the evaluation. For bacteria, both low-titre (45-152 CFU/unit) inoculation and high-titre (7·34-10·18 log CFU/unit) inoculation with two replicates for each bacterial strain were used. Platelets with non-detectable bacterial growth and platelets inoculated with a low titre were stored for 5 days, and culture was performed with the BacT/ALERT system.

RESULTS

The inactivation efficacy expressed as log reduction for Mirasol and Intercept systems for viruses was as follows: human immunodeficiency virus 1, ≥4·19 vs. ≥4·23; bovine viral diarrhoea virus, 1·83 vs. ≥6·03; pseudorabies virus, 2·73 vs. ≥5·20; hepatitis A virus, 0·62 vs. 0·76; and porcine parvovirus, 0·28 vs. 0·38. The inactivation efficacy for bacteria was as follows: Escherichia coli, 5·45 vs. ≥9·22; Staphylococcus aureus, 4·26 vs. ≥10·11; and Bacillus subtilis, 5·09 vs. ≥7·74. Postinactivation bacterial growth in platelets inoculated with a low titre of S. aureus or B. subtilis was detected only with Mirasol.

CONCLUSION

Pathogen inactivation efficacy of Intercept for enveloped viruses was found to be satisfactory. Mirasol showed satisfactory inactivation efficacy for HIV-1 only. The two selected non-enveloped viruses were not inactivated by both systems. Inactivation efficacy of Intercept was more robust for all bacteria tested at high or low titres.

A novel HLA-A*31 allele, A*31:57, identified by sequence-based typing

The novel allele A*31:57 allele showed a single nucleotide difference with A*31:01:02 at nt 235 G>C in exon 2.

A large population genetic study of 15 autosomal short tandem repeat loci for establishment of Korean DNA profile database

Genotyping of highly polymorphic short tandem repeat (STR) markers is widely used for the genetic identification of individuals in forensic DNA analyses and in paternity disputes. The National DNA Profile Databank recently established by the DNA Identification Act in Korea contains the computerized STR DNA profiles of individuals convicted of crimes. For the establishment of a large autosomal STR loci population database, 1805 samples were obtained at random from Korean individuals and 15 autosomal STR markers were analyzed using the AmpFlSTR Identifiler PCR Amplification kit. For the 15 autosomal STR markers, no deviations from the Hardy-Weinberg equilibrium were observed. The most informative locus in our data set was the D2S1338 with a discrimination power of 0.9699. The combined matching probability was 1.521 × 10(-17). This large STR profile dataset including atypical alleles will be important for the establishment of the Korean DNA database and for forensic applications.

Mutational analysis of whole mitochondrial DNA in patients with MELAS and MERRF diseases

Mitochondrial diseases are clinically and genetically heterogeneous disorders, which make the exact diagnosis and classification difficult. The purpose of this study was to identify pathogenic mtDNA mutations in 61 Korean unrelated families (or isolated patients) with MELAS or MERRF. In particular, the mtDNA sequences were completely determined for 49 patients. From the mutational analysis of mtDNA obtained from blood, 5 confirmed pathogenic mutations were identified in 17 families, and 4 unreported pathogenically suspected mutations were identified in 4 families. The m.3243A>G in the tRNA(Leu(UUR))was predominantly observed in 10 MELAS families, and followed by m.8344A>G in the tRNA(Lys) of 4 MERRF families. Most pathogenic mutations showed heteroplasmy, and the rates were considerably different within the familial members. Patients with a higher rate of mutations showed a tendency of having more severe clinical phenotypes, but not in all cases. This study will be helpful for the molecular diagnosis of mitochondrial diseases, as well as establishment of mtDNA database in Koreans.

A new HLA-B*5124 variant, B*512402 allele, identified by sequence-based typing

A novel human leukocyte antigen-B allele, officially named B*512402, was identified in a Korean bone marrow donor. The B*512402 allele shows two nucleotide substitutions compared with B*512401 in exon 3 at codons 135 (GCG --> GCC) and 138 (ACC --> ACG) without any amino acid substitution.

Haplotypes for 12 Y-chromosomal STR loci in a Korean population (the central region)

Haplotypes and allele frequencies of 12 STR loci included in the PowerPlex Y system (DYS391, DYS389I, DYS439, DYS389II, DYS438, DYS437, DYS19, DYS392, DYS393, DYS390, and DYS385a/b) were obtained from a sample of 569 unrelated individuals living in the central region of Korea. A total of 473 haplotypes were observed in the 569 individuals studied, of which 426 (90.06%) were unique. The overall haplotype diversity for the 12 Y-STR loci was 0.9985, and the discrimination capacity was 0.8313. In DYS439, we found a new intermediate-sized allele that added an A at base 3 upstream from the repeat region's first GATA motif. The allele was named 11 (U3Ains) according to its sequence structure.

Population database on nine STR loci of the AmpFℓSTR Profiler kit in Koreans

Allele frequencies for nine STR loci included in the AmpFlSTR Profiler Kit (D3S1358, vWA, FGA, TH01, TPOX, CSF1PO, D5S818, D13S317 and D7S820), were obtained from a sample of 1206 unrelated individuals living in the central region of Korea.

Population genetics of nine STR loci: TH01, TPOX, CSF1PO, vWA, FESFPS, F13A01, D13S317, D7S820 and D16S539 in a Korean population

Allele frequencies for nine STR loci namely, TH01, TPOX, CSF1PO, vWA, FESFPS, F13A01, D13S317, D7S820 and D16S539 were obtained from a sample of 437 unrelated individuals living in Chungcheong-do, South Korea.

Fungal laccase: properties and activity on lignin

The sources of ligninocellulose that occur in various forms in nature are so vast that they can only be compared to those of water. The results of several, more recent experiments showed that laccase probably possesses the big ability for "lignin-barrier" breakdown of ligninocellulose. The degradation of this compound is currently understood as an enzymatic process mediated by small molecules, therefore, this review will focus on the role of these mediators and radicals working in concert with enzymes. The fungi having a versatile machinery of enzymes are able to attack directly the "lignin-barrier" or can use a multienzyme system including "feed-back" type enzymes allowing for simultaneous transformation of lignin and carbohydrate compounds.

Influence of aromatic compounds on biodegradation of [14C]-labeled xylan and mannan by the white-rot fungus Phlebia radiata

Radiolabeled [14C]arabinoxylan from wheat meal and [14C]galactoglucomannan from red clover meal were prepared by using 14CO2 as a precursor. Twice as much mannan was mineralized than xylan after 14 days of incubation with Phlebia radiata. Low-molecular-weight phenolic compounds structurally related to lignin increased during mineralization of both hemicellulose fractions. Veratryl alcohol increased degradation of arabinoxylan by approximately 28.5%, whereas veratric acid increased it by only 9.0%. Vanillic acid and ferulic acid also stimulated degradation by 16.6% and 34.7%, respectively. Veratryl alcohol and ferulic acid increased degradation of galactoglucomannan by approximately 75%. Veratraldehyde in both cases repressed the degradation process (23.6% arabinoxylan, 43.8% galactoglucomannan). These results indicate that the degradation of hemicelluloses, e.g., xylan and mannan, by P. radiata is enhanced by addition of aromatic compounds.

Biodegradation of lignin by white rot fungi

A review is presented related to the biochemistry of lignocellulose transformation. The biodegradation of wood constituents is currently understood as a multienzymatic process with the mediation of small molecules; therefore, this review will focus on the roles of these small molecular compounds and radicals working in concert with enzymes. Wood rotting basidiomycetous fungi penetrate wood and lead to more easily metabolized, carbohydrate constituents of the complex. Having a versatile machinery of enzymes, the white rot fungi are able to attack directly the "lignin barrier." They also use a multienzyme system including so-called "feed back" type enzymes, allowing for simultaneous transformation of both lignin and cellulose. These enzymes may function separately or cooperatively.

Alterations of p53 gene in primary gastric cancer tissues

This study was conducted to investigate the p53 gene alterations in 25 surgically-resected gastric adenocarcinomas in the Korea Cancer Center Hospital by polymerase chain reaction single-strand conformation polymorphism analysis (PCR-SSCP) for exons 4-8 and immunohistochemical staining (IHCS) with anti-p53 antibody, DO-7. p53 mutations were detected in nine (36%) out of 25 cancer tissues by PCR-SSCP in exon 4-8: 0,1,1,6 and 1 mutations in exons 4,5,6,7 and 8, respectively. All tissues were also tested by IHCS, and positive staining was observed in 11 cases (44%). A discrepancy of the results between the two methods was observed in four cases. In one which showed positivity by PCR-SSCP a negative reaction by IHCS, the two base deletion was observed in exon 7. On the other hand, in three cases the mutation was detected only in IHCS but not in PCR-SSCP. The exact mechanism by which this discrepancy develops is not clear at present, although it may be due to the mutation of other exons not tested in this study or the relatively low sensitivity of the PCR-SSCP method. The incidence of p53 gene mutations was analysed according to pathologic stage and histological differentiation, but no significant difference was observed between the p53 alterations and these factors. By combined use of PCR-SSCP and IHCS, 48% of the 25 primary gastric cancer were considered to have mutations of the p53 gene. These results suggest that p53 mutation is not an infrequent event in primary gastric cancer and the p53 gene plays an important role in the carcinogenesis process of gastric cancer.