Main Characteristics of Statistical Data and the Statistical System for Wood and Wood-processing Products in Vietnam

This paper describes the characteristics of data about wood and wood-processing products published in Vietnam. The characteristics include inconsistency of data published by major data sources, lack of necessary data, and irregular publication frequency. Reasons are identified for the existence of the above characteristics of data for the wood and wood-processing industries, including recent changes in the functions of state statistical organizations and unclear concepts of data published. These characteristics create difficulties for researchers and policy-makers working at the Ministry of Agriculture and Rural Development for analysing policies and establishing supply targets for the wood and wood-processing industries in 5-year economic plans. To improve the statistical system, co-operation between state organisations and the information network (e.g. computers and internet connection) requires strengthening.     

从害虫马尾松毛虫中提取甲壳素的初步研究

采用酸碱法对马尾松毛虫蛹中甲壳素的提取方法进行了初步研究。重点分析了N aOH不同处理条件对脱有机物质和甲壳素产率的影响,确定了从马尾松毛虫蛹中提取甲壳素的基本工艺:(1)脱矿物质:盐酸浓度为2.5%,浸泡时间为20 h,浸泡温度为30℃;(2)脱有机物质:N aOH浓度为6%,浸泡温度为75℃,浸泡时间为10 h;(3)脱色:双氧水浓度为9%,浸泡时间为2.5 h,浸泡温度为80℃。在此条件下,获得的甲壳素产品为白色粉状固体,其N含量为6.87%,灰分为1.19%,水分为8.37%。产率为29.97%。产品的N含量达到食品级甲壳素标准,灰分含量达到工业级甲壳素标准。实验有助于后续深入研究马尾松毛虫蛹中甲壳素的提取,也为今后进一步制备虫蛹壳聚糖打下了基础。     

Effect of a Single Dose of Cadmium on Pregnant Wistar Rats and their Offspring

Cadmium (Cd) is a well‐known toxicant targeting many organs, among them placenta. This heavy metal also has embryonary and foetal toxicity. This study was undertaken to analyse the effect of a single Cd dose administered at 4, 7, 10 or 15 days of gestation on the offspring of pregnant rats sacrificed at 20 days of gestation. Cadmium chloride was administered subcutaneously at 10 mg/kg body weight to Wistar pregnant dams; control animals received a proportionate volume of sterile normal saline by the same route. Maternal uteri, livers, kidneys and lungs, and foetuses were examined at necropsy. Samples of maternal organs and whole foetuses were collected for histopathologic examination, determination of Cd levels and staining by the Alizarin red S technique. Results revealed a clear embryotoxic and a teratogenic effect of this heavy metal, the former as a significant increase in the number of resorptions, and the latter as significant decrease of the gestational sac weight, and the size and weight of foetuses of Cd‐treated dams as well as induced malformations in skull bones, vertebrae and thoracic, and pelvian limbs. The deleterious effects found were similar to those previously reported for other animal models suggesting a high conservation of the pathogenic mechanisms of Cd. Additionally, many of the addressed aspects showed a slight dependence on the time of administration of the toxic that might be due to the accumulation of the metal in different organs, as we were able to demonstrate by the analysis of its concentration.     

Mice cloned by nuclear transfer from somatic and ntES cells derived from the same individuals

The current success rate of cloned mice from adult somatic cell nuclei is very low, whereas it is relatively high for cloned mice from ES cell nuclei. In this experiment, we examined whether the success rate of cloning from somatic cells could be improved via nuclear transfer embryonic stem cells (ntES cells) established from somatic cell nuclei. We obtained 11 cloned mice and 68 ntES cell lines from the somatic cell nuclei of 7 mice, and cloned 41 mice were cloned from the ntES cell nuclei. Unexpectedly, the overall success rate of cloning from ntES cell nuclei in this series was no better than when using somatic cell nuclei. Interestingly, full-term cloned mice were produced only via ntES cells from two individuals, but not by direct nuclear transfer from the somatic cells, and vice versa. Ultimately, we were able to obtain clone mice from 6 out of 7 individuals using either somatic cells or ntES cells. Thus, although ntES cells as donor nuclei do not absolutely assure a better success rate for mouse cloning than somatic cells, to preserve and clone valuable individuals, we recommend that ntES cell lines be established. These can then be used as an unlimited source of donor nuclei for nuclear transfer, and thus complement conventional somatic cell nuclear transfer cloning approaches.     

Molecular and Pathotype Analysis of the Rice Blast Fungus in North Vietnam

Rice blast caused by Pyricularia oryzae is a devastating disease worldwide. In Vietnam, rice blast is especially severe in the Red River Delta in the North. The genetic diversity of 114 P. oryzae isolates collected from rice in 2001 in the Red River Delta and nine additional Vietnamese P. oryzae isolates was analysed using Amplified Fragment Length Polymorphism (AFLP). DNA similarity and cluster analysis based on 160 polymorphic AFLP markers showed twelve different AFLP genetic groups among the 123 field isolates. Isolates collected from japonica hosts clustered separately from indica host isolates with at least 60% dissimilarity with little evidence for gene flow between the two populations. In the 2001 population originating from indica hosts, three genetic groups were predominant and represented 99% of the isolates sampled. One predominant clonal lineage represented 59% of the 2001 indica host population and was found in eleven provinces in the Red River Delta of North Vietnam. Significant genotype flow could be demonstrated between the indica population south of Red river and the indica population north of Red river. There was significant linkage disequilibrium between the AFLP loci within the indica population, indicating that this is not a random mating population. Pathogenicity tests of 25 isolates selected from the 12 AFLP groups on a set of 29 differential rice lines revealed two avirulent isolates and 23 pathotypes. Different combinations of known resistance genes were found to have potential for blast resistance breeding for North Vietnam. First two authors contributed equally     

The Endo-α(1,3)-Fucoidanase Mef2 Releases Uniquely Branched Oligosaccharides from Saccharina latissima Fucoidans

Fucoidans are complex bioactive sulfated fucosyl-polysaccharides primarily found in brown macroalgae. Endo-fucoidanases catalyze the specific hydrolysis of α-L-fucosyl linkages in fucoidans and can be utilized to tailor-make fucoidan oligosaccharides and elucidate new structural details of fucoidans. In this study, an endo-α(1,3)-fucoidanase encoding gene, Mef2, from the marine bacterium Muricauda eckloniae, was cloned, and the Mef2 protein was functionally characterized. Based on the primary sequence, Mef2 was suggested to belong to the glycosyl hydrolase family 107 (GH107) in the Carbohydrate Active enZyme database (CAZy). The Mef2 fucoidanase showed maximal activity at pH 8 and 35 °C, although it could tolerate temperatures up to 50 °C. Ca²⁺ was shown to increase the melting temperature from 38 to 44 °C and was furthermore required for optimal activity of Mef2. The substrate specificity of Mef2 was investigated, and Fourier transform infrared spectroscopy (FTIR) was used to determine the enzymatic activity (Units per μM enzyme: U_f/μM) of Mef2 on two structurally different fucoidans, showing an activity of 1.2 × 10⁻³ U_f/μM and 3.6 × 10⁻³ U_f/μM on fucoidans from Fucus evanescens and Saccharina latissima, respectively. Interestingly, Mef2 was identified as the first described fucoidanase active on fucoidans from S. latissima. The fucoidan oligosaccharides released by Mef2 consisted of a backbone of α(1,3)-linked fucosyl residues with unique and novel α(1,4)-linked fucosyl branches, not previously identified in fucoidans from S. latissima.     

Successful mouse cloning of an outbred strain by trichostatin A treatment after somatic nuclear transfer

Although the somatic cloning technique has been used for numerous applications and basic research of reprogramming in various species, extremely low success rates have plagued this technique for a decade. Further in mice, the "clonable" strains have been limited to mainly hybrid F1 strains such as B6D2F1. Recently, we established a new efficient cloning technique using trichostatin A (TSA) which leads to a 2-5 fold increase in success rates for mouse cloning of B6D2F1 cumulus cells. To further test the validity of this TSA cloning technique, we tried to clone the adult ICR mouse, an outbred strain, which has never been directly cloned before. Only when TSA was used did we obtain both male and female cloned mice from cumulus and fibroblast cells of adult ICR mice with 4-5% success rates, which is comparable to 5-7% of B6D2F1. Thus, the TSA treatment is the first cloning technique to allow us to successfully clone outbred mice, demonstrating that this technique not only improves the success rates of cloning from hybrid strains, but also enables mouse cloning from normally "unclonable" strains.     

A long-term observation for ecology of pathogenic Yersinia in wild rodents living in Fukushima Prefecture,Japan

From 2012 to 2021, prevalence of pathogenic Yersinia in wild rodents captured in Fukushima Prefecture, Japan was investigated twice a year to clarify the ecology of this pathogen in wild rodent populations. Pathogenic Yersinia enterocolitica O8 was isolated from 13 (1.7%) of 755 wild rodents. The Y. enterocolitica O8 isolates harbored three virulent genes (ail, fyuA, and virF). This pathogen was isolated repeatedly from wild rodents in April 2015, 2016, and 2017, in June and November 2020, and in April 2021, which was 6 of 19 times of observations. All Y. enterocolitica O8 isolates showed the same PFGE patterns. These results indicated that the same clone of pathogenic Y. enterocolitica O8 has been maintained in wild rodent populations in Fukushima Prefecture. Therefore, wild rodent populations contribute substantially to the continuous transmission of Y. enterocolitica O8 and its persistence in the ecosystem. This is the first report on the isolation of pathogenic Y. enterocolitica O8 in wild rodents in Fukushima Prefecture, Japan.     

Production of offspring from one-day-old oocytes stored at room temperature

To determine the feasibility of preserving oocytes without freezing, we stored mouse oocytes in several media at different temperatures for one day. Confocal microscopy of the metaphase-II spindle in these stored oocytes revealed gross abnormalities in both the spindle and the arrangement of chromosomes. The abnormal spindles could not be rescued by transplanting the aged spindle-chromosome complex into a fresh enucleated oocyte. A diploid parthenogenetic development showed that some of the oocytes stored at room temperature could still develop into blastocysts (10-57%). However, oocytes stored in a refrigerator (5%) or incubator (0%) lost the potential almost entirely. Fertilization of room-temperature-preserved oocytes with fresh spermatozoa by ICSI or IVF resulted in, respectively, 4 and 10%, full-term births. These results suggest that when oocytes are stored at room temperature for one day, most have irreversible damage not only to their cytoplasm but also to the spindle. However, since at least a few percent of stored oocytes retained the potential for full-term development, it may be possible to overcome these problems and develop a simple method for preserving mammalian oocytes without freezing.