Acute effects of resistance exercise on arterial compliance.

Decreased central arterial compliance is an emerging risk factor for cardiovascular disease. Resistance training is associated with reductions in the elastic properties of central arteries. Currently, it is not known whether this reduction is from one bout of resistance exercise or from an adaptation to multiple bouts of resistance training. Sixteen healthy sedentary or recreationally active adults (11 men and 5 women, age 27 +/- 1 yr) were studied under parallel experimental conditions on 2 separate days. The order of experiments was randomized between resistance exercise (9 resistance exercises at 75% of 1 repetition maximum) and sham control (seated rest in the exercise room). Baseline hemodynamic values were not different between the two experimental conditions. Carotid arterial compliance (via simultaneous B-mode ultrasound and applanation tonometry) decreased and beta-stiffness index increased (P < 0.01) immediately and 30 min after resistance exercise. Immediately after resistance exercise, carotid systolic blood pressure increased (P < 0.01), although no changes were observed in brachial systolic blood pressure at any time points. These measures returned to baseline values within 60 min after the completion of resistance exercise. No significant changes in these variables were observed during the sham control condition. These results indicate that one bout of resistance exercise acutely decreases central arterial compliance, but this effect is sustained for <60 min after the completion of resistance exercise.     

Comparison of identity by descent and identity by state for detecting genetic regions under selection in a sorghum pedigree breeding program

Seventy sorghum inbred lines which formed part of the Queensland Department of Primary Industries (QDPI) sorghum breeding program were screened with 104 previously mapped RFLP markers. The lines were related by pedigree and consisted of ancestral source lines, intermediate lines and recent releases from the program. We compared the effect of defining marker alleles using either identity by state (IBS) or identity by descent (IBD) on our capacity to trace markers through the pedigree and detect evidence of selection for particular alleles. Allelic identities defined using IBD were much more sensitive for detecting non-Mendelian segregation in this pedigree. Only one marker allele showed significant evidence of selection when IBS was used compared with ten regions with particular allelic identities when IBD was used. Regions under selection were compared with the location of QTLs for agronomic traits known to be under selection in the breeding program. Only two of the ten regions were associated with known QTLs that matched with knowledge of the agronomic characteristics of the ancestral lines. Some of the other regions were hypothesised to be associated with genes for particular traits based on the properties of the ancestral source lines.     

Do effects of ultraviolet radiation on microbial films have indirect effects on larval attachment of the barnacle Balanus amphitrite?

We have examined the indirect effects of UV-A and UV-B on cypris attachment of the barnacle Balanus amphitrite Darwin through their effects on microbial films. Specifically, we tested the hypothesis that both UV-A and UV-B radiation can indirectly affect the larval attachment of barnacles by altering the microbial film bioactivity. Microbial films were developed from mid-intertidal region (∼1 m above Mean Low Water Level) for 6 days and subjected to ambient levels of ultraviolet radiation. Response of cyprids to untreated and UV-treated microbial films was investigated using double-dish still water choice bioassay. Results showed that both UV-A and UV-B caused a decrease in the percentage of respiring bacterial cells in microbial films and this effect increased with UV energy. With the same UV energy, UV-B caused a greater decrease in respiring bacterial cells than UV-A. However, despite strong UV radiation, the bioactivities of microbial films (i.e., stimulation of cypris attachment) remain unchanged. Results of this study suggest that increased UV radiation, which might occur due to ozone depletion, may not significantly affect the barnacle recruitment by means of affecting the inductive larval attachment cues of microbial films.     

Stability study on the nitrile hydratase of Nocardia sp. 108: From resting cells to crude enzyme preparation

In recent years nitrile hydratases (NHases) have drawn increasing attention due to their critical roles in organic synthesis. In the present paper an extensive investigation on the stability and activity of NHase from Nocardia sp. 108, which has succeeded in industrial application in China, was conducted by bioconversion of acrylonitrile to acrylamide in a batch manner. A study of cultivation demonstrated that biosynthesis of NHase changed significantly with the time of the culture, and the optimal NHase biosynthesis phase was 45 h after inoculation with NHase activity of a biomass of 1209.8 U/g. A stability study indicated that both crude enzyme preparations exhibited a good stability when exposed to a pH 7.2 tris-HCl buffer at 4°C for 4 h. The text was submitted by the authors in English.     

异三聚体G蛋白在NAA诱导的拟南芥根生长发育中的作用

以拟南芥的野生型(ws)、异三聚体G蛋白α亚基基因GPA1缺失突变体(gpa1-1,gpa1-2)和超表达突变体(wGα,cGα)为材料,通过施加不同浓度(0~0.2 mg/L)的NAA处理,对拟南芥根生长发育的一些形态指标进行了观测比较.结果表明:(1)随着培养基中NAA浓度的不断升高,5种基因型主根的伸长生长均受到抑制,且抑制作用随浓度升高而增强;4种突变体和野生型主根的生长在相同浓度NAA处理下,无明显差异;(2)NAA在一定浓度范围内,对拟南芥侧根的生长发育起促进作用;在NAA诱导的侧根生长中,G蛋白超表达突变体比野生型更敏感,缺失突变体则不敏感.初步证明G蛋白不参与主根生长发育的调节,而在侧根生长发育中可能起正调节作用.     

One-step enzymatic synthesis of blue pigments from geniposide for fabric dyeing

In this study, we describe a one-step chemoenzymatic reaction for the production of natural blue pigments, in which the geniposide from Gardenia extracts is transformed by glycosidases to genipin. Genipin is then allowed to react with amino acids, thereby generating a natural blue pigment. The β-glycosidases, most notably isolase (a variant of β-glucanase), recombinant β-glucosidase, Cellulase T, and amylases, were shown to hydrolyze geniposide to produce the desired pigments, whereas the α-glycosidases did not. Among the 20 tested amino acids, glycine and tyrosine were associated with the highest dye production yields. The optimal molar ratio of geniposide to glycine, two reactants relevant to pigment production, was unity. The natural blue pigments produced in this study were used to dye cotton, silk, and wool. The color yields of the pigments were determined to be significantly higher than those of other natural dyes. Furthermore, the color fastness properties of these dyes were fairly good, even in the absence of mordant.     

New and reassessed species of Strobilanthes (Acanthaceae) in the flora of China

Several problems in Strobilanthes Blume (Acanthaceae: Ruelliae) are clarified as a result of collaboration between Chinese and western botanists. Examination of pollen has permitted clear delimitation of four morphologically similar species, Strobilanthes szechuanica (Batalin) J. R. I. Wood & Y. F. Deng, S. labordei H. Lév., S. wakasana Wakasugi & Naruhashi and S. wilsonii J. R. I. Wood & Y. F. Deng, the latter described for the first time in this paper, although first collected more than a hundred years ago. A key is provided to help distinguish these species. The globose, echinulate pollen found in several species from China and Japan and assigned to the genus Championella by Bremekamp is shown by SEM photography to be distinct from other pollen hitherto regarded as the same. Three new species, S. abbreviata Y. F. Deng & J. R. I. Wood, S. lihengiae Y. F. Deng & J. R. I. Wood and S. vallicola Y. F. Deng & J. R. I. Wood are described. S. austinii C. B. Clarke ex W. W. Sm. is lectotypified to show that it is conspecific with S. lamiifolia (Nees) T. Anderson, a species demonstrating trans-Himalayan links. New combinations are made for four species as the authors recognize only a single genus, Strobilanthes within the Strobilanthinae as defined by Bremekamp. S. gongshanensis Tsui and S. aenobarba W. W. Sm. are shown to be only varieties of S. inflata T. Anderson. Illustrations are provided for all new species.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 369–390.     

A characteristic pharmacological action of ‘Yang-invigorating’ Chinese tonifying herbs: Enhancement of myocardial ATP-generation capacity

In order to investigate the pharmacological basis of ‘Yang-invigorating’ action, the effect of oral treatment with the methanolic extract of ‘Yang-invigorating’ herbs on ATP-generation capacity was examined, using heart homogenates prepared from herb-pretreated mice. Tonifying (i.e., health-promoting) herbs of other functional categories were also included for comparison. The results indicated that ‘Yang-invigorating’ Chinese tonifying herbs could invariably enhance myocardial ATP-generation capacity, with the extent of stimulation varying among the herbs. In contrast, ‘Yin-nourishing’ herbs either did not stimulate or even decreased myocardial ATP-generation capacity. While ‘Qi-invigorating’ herbs produced variable effects on myocardial ATP-generation capacity, most of the ‘blood-enriching’ herbs did not cause any significant changes. The results obtained from studies using myocardial mitochondrial fractions isolated from herb-pretreated mice suggest that ‘Yang-invigorating’ herbs might speed up ATP generation by increasing mitochondrial electron transport. The ensemble of results has provided evidence for the first time to support the pharmacological basis of ‘Yang invigoration’ in Chinese medicine.     

Hypoglycemic activity of polysaccharide, with antioxidation, isolated from cultured Cordyceps mycelia

Cordyceps sinensis, a well-known traditional Chinese medicine, possesses anti-tumor, immunostimulant and antioxidant activities; however, the identities of active components have not been determined. In our previous study using antioxidant activity-guided fractionation [Li et al., 2003. A polysaccharide isolated from Cordyceps sinensis, a traditional Chinese medicine, protects PC12 cells against hydrogen peroxide-induced injury. Life Sci. 73, 2503-2513], a polysaccharide of molecular weight approximately 210kDa was isolated from cultured Cordyceps mycelia by ion-exchange and sizing chromatography. The isolated polysaccharide, named CSP-1, which has strong anti-oxidation activity, contains glucose, mannose and galactose in the ratio of 1:0.6:0.75. In the present study, we demonstrated the hypoglycemic effect of CSP-1 on normal and alloxan-diabetic mice and streptozotocin (STZ)-diabetic rats. The basal glucose level did not differ significantly among the normal mice. CSP-1 (at 200 and 400mg/kg body wt./day for 7 days, p.o.), however, significantly reduced the blood glucose level by 12.0+/-3.2% and 22.5+/-4.7% in normal mice, respectively (p<0.05). When administered at a dose of higher than 200mg/kg body wt. daily for 7 days, CSP-1 produced a significant drop in blood glucose level in both STZ-induced diabetic rats and alloxan-induced diabetic mice. The serum insulin levels in diabetic animals were also increased by administration of CSP-1 (p<0.05). CSP-1 with hypoglycemic properties increased circulating insulin level in diabetic animals, which suggests that CSP-1 may stimulate pancreatic release of insulin and/or reduce insulin metabolism.     

Hypoglycemic effects of the wood of Taxus yunnanensis on streptozotocin-induced diabetic rats and its active components

Hypoglycemic effects of the H(2)O and MeOH extracts of the wood of Taxus yunnanensis were examined in streptozotocin (STZ)-induced diabetic rats. The H(2)O extract significantly lowered the fasting blood glucose level by 33.7% at a 100mg/kg dose on intraperitoneal administration. From the active H(2)O extract of the wood, three lignans, i.e., isotaxiresinol (1), secoisolariciresinol (2) and taxiresinol (3), were isolated as major components. These lignans were further tested for their hypoglycemic effects on the same experimental model. At a dose of 100mg/kg (i.p.), isotaxiresinol (1) reduced the fasting blood glucose level of diabetic rats by 34.5%, while secoisolariciresinol (2) and taxiresinol (3) reduced by 33.4% and 20.9%, respectively. The blood glucose lowering effects of 1 and 2 were stronger than the mixture of tolbutamide (200mg/kg) and buformin (1mg/kg) used as a positive control, which lowered fasting blood glucose level by 24.0%.