TaADF7, an actin-depolymerizing factor, contributes to wheat resistance against Puccinia striiformis f. sp. tritici.

The actin cytoskeleton is involved in plant defense responses; however, the role of the actin-depolymerizing factor (ADF) family, which regulates actin cytoskeletal dynamics, in plant disease resistance, is largely unknown. Here, we characterized a wheat (Triticum aestivum) ADF gene, TaADF7, with three copies located on chromosomes 1A, 1B, and 1D, respectively. All three copies encoded the same protein, although there were variations in 19 nucleotide positions in the open reading frame. Transcriptional expression of the three TaADF7 copies were all sharply elevated in response to avirulent Puccinia striiformis f. sp. tritici (Pst) infection, with similar expression patterns. TaADF7 regulated the actin cytoskeletal dynamics by targeting the actin cytoskeleton to execute actin binding/severing activities. When the TaADF7 copies were all silenced by virus-induced gene silencing, the growth of Pst hypha increased and sporadic urediniospores were observed, as compared with control plants, upon inoculation with avirulent Pst. In addition, the accumulation of reactive oxygen species (ROS) and the hypersensitive response (HR) were greatly weakened, whereas cytochalasin B partially rescued the HR in TaADF7 knock-down plants. Together, these findings suggest that TaADF7 is likely to contribute to wheat resistance against Pst infection by modulating the actin cytoskeletal dynamics to influence ROS accumulation and the HR.

[Role of insulin resistance and ß cell function in the development of newly diagnosed type 2 diabetes].

OBJECTIVE: To assess the possible role of insulin resistance (IR) and ß cell function in the pathophysiology of newly diagnosed type 2 diabetics (T2DM). METHODS: An oral glucose tolerance test was obtained at the health cohort baseline. Subjects with normal glucose tolerance (NGT, n = 269), impaired glucose regulation (IGR, n = 269) and newly diagnosed type 2 diabetics (T2DM, n = 269) were defined by ADA criteria. Subjects with NGT and IGR were selected from residents living in the same community of diabetic patients with the same gender and age (± 3 years old). The T2DM group was sub-classified as isolated fasting hyperglycemia (IFH), isolated post-challenge hyperglycemia (IPH) and combined hyperglycemia (CH). The IGR group was sub-classified as impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and combined glucose intolerance (CGI). Homeostasis model assessment of insulin resistance (HOMA-IR), ß cell function (HOMA-ß) and deposition index (DI) were to evaluate the insulin resistance or sensitivity, islet ß cell function and that when insulin compensated respectively. RESULTS: From NGT to T2DM, HOMA-IR increased while HOMA-ß and DI decreased significantly (P < 0.05). After the adjustment of age, gender, obesity and hypertension, IFG and CGI subgroup had statistically higher HOMA-IR and lower HOMA-ß and DI, and IGT subgroup only had lower HOMA-ß and DI than NGT subgroup (P < 0.05). Compared to IGT subgroup, IFG and CGI subgroup had significantly higher HOMA-IR and lower HOMA-ß and DI (P < 0.05). IFH and CH subgroup had statistically higher HOMA-IR and lower HOMA-ß and DI than IFH subgroup (P < 0.05), DI of CH subgroup significantly decreased than that of IPH subgroup (P < 0.05). IFH and CH subgroup had statistically higher HOMA-IR and lower HOMA-ß and DI than IFG and CGI subgroup respectively. HOMA-ß and DI decreased of IPH subgroup compared to IGT subgroup, and multiple linear regression analysis showed that HOMA-IR had significant influence on fasting plasma glucose (FPG) in NGT (P < 0.05), whereas two-hour plasma glucose and FPG were influenced by DI (P < 0.05) in the progression. CONCLUSIONS: Both basic ß cell dysfunction and IR exist in IFG and CGI, while only basic ß cell dysfunction exist in IGT. The basic ß cell dysfunction and IR are the primary features of fasting hyperglycemia, and basic ß cell dysfunction also contribute to post- challenge hyperglycemia.

Population genetic diversity of Puccinia striiformis f. sp. tritici on different wheat varieties in Tianshui, Gansu Province.

Population genetic diversity in Tianshui city was analyzed with SSR markers in 605 single-pustule isolates of the stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst), obtained from 19 varieties of wheat. Significant differences in genetic diversity among populations were defected. Genetic diversity was highest in population on Tian 863-13, a highly resistant variety, whereas genetic diversity was lowest in population on Huixianhong, a highly susceptible variety. Seven populations from seven varieties that carried the common Yr18 resistance gene were clustered as one sub-group at 0.88 similarity coefficient, which showed that resistance gene selection had close relation with pathogen's component. The results of present study can provide a theoretical basis for integrated management of wheat stripe rust and effective deployment of resistance genes in Pst over-summering zones in China.

Global COVID-19 childhood disability data coordination: A collaborative initiative of the International Alliance of Academies of Childhood Disability.

PURPOSE: The International Alliance of Academies of Childhood Disability created a COVID-19 Task Force with the goal of understanding the global impact of COVID-19 on children with disabilities and their families. The aim of this paper is to synthesize existing evidence describing the impact of COVID-19 on people with disabilities, derived from surveys conducted across the globe. METHODS: A descriptive environmental scan of surveys was conducted. From June to November 2020, a global call for surveys addressing the impact of COVID-19 on disability was launched. To identify gaps and overlaps, the content of the surveys was compared to the Convention on the Rights of the Child and the International Classification of Functioning, Disability and Health. RESULTS: Forty-nine surveys, involving information from more than 17,230 participants around the world were collected. Overall, surveys identified that COVID-19 has negatively impacted several areas of functioning - including mental health, and human rights of people with disabilities and their families worldwide. CONCLUSION: Globally, the surveys highlight that impact of COVID-19 on mental health of people with disabilities, caregivers, and professionals continues to be a major issue. Rapid dissemination of collected information is essential for ameliorating the impact of COVID-19 across the globe.

TaMCA4, a novel wheat metacaspase gene functions in programmed cell death induced by the fungal pathogen Puccinia striiformis f. sp. tritici.

Programmed cell death (PCD) is a physiological process to remove redundant or harmful cells, for the development of multicellular organisms, or for restricting the spread of pathogens (hypersensitive response). Metacaspases are cysteine-dependent proteases which play an essential role in PCD. Triticum aestivum metacaspase 4 (TaMCA4) is a type II metacaspase gene cloned from 'Suwon11' wheat, with typical structural features such as peptidase C14 caspase domain and a long linker sequence between the two subunits. Transient expression of TaMCA4 in tobacco leaves failed to induce PCD directly but enhanced cell death triggered by a mouse Bax gene or a candidate effector gene from Puccinia striiformis f. sp. tritici. Enhancement of PCD was also observed in wheat leaves co-bombarded with TaMCA4. When challenged with the avirulent race of P. striiformis f. sp. tritici, the expression level of TaMCA4 in wheat leaves was sharply upregulated, whereas the transcript level was not significantly induced by the virulent race. Moreover, knocking down TaMCA4 expression by virus-induced gene silencing enhanced the susceptibility of Suwon11 to the avirulent race of P. striiformis f. sp. tritici and reduced the necrotic area at infection sites.

Characterization of non-host resistance in broad bean to the wheat stripe rust pathogen.

BACKGROUND: Non-host resistance (NHR) confers plant species immunity against the majority of microbial pathogens and represents the most robust and durable form of plant resistance in nature. As one of the main genera of rust fungi with economic and biological importance, Puccinia infects almost all cereals but is unable to cause diseases on legumes. Little is known about the mechanism of this kind of effective defense in legumes to these non-host pathogens. RESULTS: In this study, the basis of NHR in broad bean (Vicia faba L.) against the wheat stripe rust pathogen, Puccinia striiformis f. sp. tritici (Pst), was characterized. No visible symptoms were observed on broad bean leaves inoculated with Pst. Microscopic observations showed that successful location of stomata and haustoria formation were significantly reduced in Pst infection of broad bean. Attempted infection induced the formation of papillae, cell wall thickening, production of reactive oxygen species, callose deposition and accumulation of phenolic compounds in plant cell walls. The few Pst haustoria that did form in broad bean cells were encased in reactive oxygen and callose materials and those cells elicited cell death. Furthermore, a total of seven defense-related genes were identified and found to be up-regulated during the Pst infection. CONCLUSIONS: The results indicate that NHR in broad bean against Pst results from a continuum of layered defenses, including basic incompatibility, structural and chemical strengthening of cell wall, posthaustorial hypersensitive response and induction of several defense-related genes, demonstrating the multi-layered feature of NHR. This work also provides useful information for further determination of resistance mechanisms in broad bean to rust fungi, especially the adapted important broad bean rust pathogen, Uromyces viciae-fabae, because of strong similarity and association between NHR of plants to unadapted pathogens and basal resistance of plants to adapted pathogens.

Histological and cytological characterization of adult plant resistance to wheat stripe rust.

UNLABELLED: Wheat cultivar Xingzi 9104 (XZ) possesses adult plant resistance (APR) to stripe rust caused by Puccinia striiformis f. sp. tritici (Pst). In this study, histological and cytological experiments were conducted to elucidate the mechanisms of APR in XZ. The results of leaf inoculation experiments indicated that APR was initiated at the tillering stage, gradually increased as the plant aged and highly expressed after boot stage. The histology and oxidative burst in infected leaves of plants at seedling, tillering and boot stages were examined using light microscopic and histochemical methods. Subcellular changes in the host-pathogen interactions during the seedling and boot stages were analyzed by transmission electron microscopy. The results showed that haustorium formation was retarded in the adult plants and that the differentiation of secondary intercellular hyphae was significantly inhibited, which decreased the development of microcolonies in the adult plants, especially in plants of boot stage. The expression of APR to stipe rust during wheat development was clearly associated with extensive hypersensitive cell death of host cells and localized production of reactive oxygen species, which coincided with the restriction of fungal growth in infection sites in adult plants. At the same time, cell wall-related resistance in adult plants prevented ingression of haustorial mother cells into plant cells. Haustorium encasement was coincident with malformation or death of haustoria. The results provide useful information for further determination of mechanisms of wheat APR to stripe rust. KEY MESSAGE: The expression of APR to stipe rust in wheat cultivar Xingzi 9104 (XZ) was clearly associated with extensive hypersensitive cell death of host cells and the localized production of reactive oxygen species.

Histological and molecular studies of the non-host interaction between wheat and Uromyces fabae.

Non-host resistance (NHR) confers plant species immunity against the majority of microbes. As an important crop, wheat can be damaged by several Puccinia species but is immune to all Uromyces species. Here, we studied the basis of NHR in wheat against the broad bean rust pathogen Uromyces fabae (Uf). In the wheat-Uf interaction, microscopic observations showed that urediospores germinated efficiently on wheat leaves. However, over 98% of the germ tubes failed to form appressoria over stomata. For the few that invaded through stomata, the majority of them failed to penetrate wheat mesophyll cells. At 96 hours after inoculation, less than 4% of the Uf infection units that had entered the mesophyll tissue formed haustoria. Attempted penetration by haustorium mother cells induced the thickening of cell wall and the formation of papillae in plant cells, which arrested the development or growth of Uf penetration pegs. For the Uf haustoria formed in wheat cells, they were encased in callose-like materials and did not elicit hypersensitive response. Localized accumulation of H(2)O(2) were observed in plant cell walls, papillae and encasement of haustoria during the wheat-Uf interaction. Furthermore, quantitative RT-PCR analysis showed that several genes involved in basal resistance and oxidative stress responses were up-regulated during Uf infection. In conclusion, our study revealed the cytological and molecular bases of NHR in wheat against the non-adapted rust fungus Uf, and highlighted the significance of papilla production in the prehaustorial NHR.

[Heat impact upon the infectivity of hepatitis B virus in serum].

OBJECTIVE: This article was to explore the impact of temperature on hepatitis B virus infectivity. METHODS: HBV positive serum with a HBV DNA titer of 1.33 × 10(8) copies/ml was aliquots into 23 Ep tubes with 1.5 ml, 100 µl in one tube.15 tubes were incubated at 37, 56 and 65°C for 0, 30, 60, 120 and 600 minutes, respectively. The other 8 tubes were incubated at 98°C for 0, 5, 10 and 30 minutes, respectively. Post-treated serum at all time points were selected to infect HepG-2 cell. When 18 hours after infection, these cells were extensively washed with phosphate buffered saline. Cells were harvested after the addition of fresh culture medium to culture cells for 48 hours. HBV DNA was detected by FQ-PCR. RESULTS: HBV DNA was detected in cells that were infected by serum at 37°C and 56°C for 30, 60, 120 and 600 minutes, respectively. The titers for the cells incubated at 37°C were (4.85 ± 1.71) × 10(5), (3.85 ± 1.76) × 10(5), (1.67 ± 0.67) × 10(5), (7.86 ± 1.03) × 10(4) copies/ml, and those for the cells incubated at 56°C were (4.01 ± 0.16) × 10(5), (9.77 ± 0.97) × 10(4), (6.36 ± 0.65) × 10(4), (5.05 ± 0.24) × 10(3) copies/ml at different incubation time points. For the cells incubated at 65°C for 60 and 120 minutes, HBV DNAs were (5.15 ± 7.28) × 10(3) and (7.56 ± 10.60) × 10(2) copies/ml, respectively, which were much lower than those in the controls cells ((6.79 ± 1.48) × 10(5) copies/ml). The results of HBV DNA were different (F = 104.4, P < 0.001) in groups treated with different temperature, and results of HBV DNA were also different (F = 144.0, P < 0.001) in groups processed for different period of time. Temperature and processing time had interaction (F = 23.6, P < 0.001). After heating at 98°C for 10 minutes and boiling for 5 minutes, the HBV DNA copy number ((3.02 ± 4.26) × 10(2), (4.31 ± 6.09) × 10(2) copies/ml) in infected cells decreased by about 10 folds than that in the control group ((6.79 ± 1.48) × 10(5) copies/ml). HBV DNAs were not detected in cells that were infected by serum which was heated at 98°C for 30 minutes and boiled for 10 minutes. CONCLUSION: The infectivity of HBV serum in vitro was relatively stable at low temperature, and it would lose its infectivity in short period of time at high temperature.

[Prevalence of overweight and its relationship with hyperglycaemia in adults of rural communities in Deqing County, China].

OBJECTIVE: To understand the prevalence of overweight and its relationship with hyperglycaemia in adults in rural Deqing county, China. METHOD: A cross-sectional study was carried out in four rural communities randomly sampled from Deqing county, Zhejiang province, China. A total of 5840 subjects aged 18 to 64 years participated in this study. General demographics and items related to health were collected and the length, weight, fast glucose etc of subjects were measured. EpiData 3.1 (Chinese version) was used to manage the data and SPSS 16.0 was used for statistical analysis. RESULT: The average BMI was 22.7 +/- 11.6 kg/m2, the crude prevalence of overweight was 25.1% (of obesity was 3.8%) and the age-gender-standardized prevalence of overweight was 21.8%. There was a significantly higher trend of overweight with age regardless of gender, especially after 35 years old (chi2(Trend) = 5.61, P = 0.018 for men; chi2(Trend) = 50.96, P < 0.001 for women; chi2(Trend) = 14.05, P < 0.001). The risk of impaired fasting glucose (IFG) and diabetes mellitus (DM) (adjusted OR = 1.8, 95% CI 1.34 - 2.37 and 3.7, 95% CI 2.42 -5.65, respectively) in subjects with overweight was significantly higher than that in subjects without overweight/obesity in the multinomial Logistic model; and the risk of IFG and DM was increased 14% and 24% respectively with the increase of one BMI unit (adjusted OR = 1.14, 95% CI: 1.10 - 1.20 and adjusted OR = 1.24, 95% CI 1.16 - 1.32, respectively). CONCLUSION: The prevalence of overweight in adults aged 18 to 64 years old was high in rural Deqing, which was significantly associated with IFG and DM.

Differential gene expression in incompatible interaction between wheat and stripe rust fungus revealed by cDNA-AFLP and comparison to compatible interaction.

BACKGROUND: Stripe rust of wheat, caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important diseases of wheat worldwide. Due to special features of hexaploid wheat with large and complex genome and difficulties for transformation, and of Pst without sexual reproduction and hard to culture on media, the use of most genetic and molecular techniques in studying genes involved in the wheat-Pst interactions has been largely limited. The objective of this study was to identify transcriptionally regulated genes during an incompatible interaction between wheat and Pst using cDNA-AFLP technique RESULTS: A total of 52,992 transcript derived fragments (TDFs) were generated with 64 primer pairs and 2,437 (4.6%) of them displayed altered expression patterns after inoculation with 1,787 up-regulated and 650 down-regulated. We obtained reliable sequences (>100 bp) for 255 selected TDFs, of which 113 (44.3%) had putative functions identified. A large group (17.6%) of these genes shared high homology with genes involved in metabolism and photosynthesis; 13.8% to genes with functions related to disease defense and signal transduction; and those in the remaining groups (12.9%) to genes involved in transcription, transport processes, protein metabolism, and cell structure, respectively. Through comparing TDFs identified in the present study for incompatible interaction and those identified in the previous study for compatible interactions, 161 TDFs were shared by both interactions, 94 were expressed specifically in the incompatible interaction, of which the specificity of 43 selected transcripts were determined using quantitative real-time polymerase chain reaction (qRT-PCR). Based on the analyses of homology to genes known to play a role in defense, signal transduction and protein metabolism, 20 TDFs were chosen and their expression patterns revealed by the cDNA-AFLP technique were confirmed using the qRT-PCR analysis. CONCLUSION: We uncovered a number of new candidate genes possibly involved in the interactions of wheat and Pst, of which 11 TDFs expressed specifically in the incompatible interaction. Resistance to stripe rust in wheat cv. Suwon11 is executed after penetration has occurred. Moreover, we also found that plant responses in compatible and incompatible interactions are qualitatively similar but quantitatively different soon after stripe rust fungus infection.

Characterization of a pathogenesis-related thaumatin-like protein gene TaPR5 from wheat induced by stripe rust fungus.

Pathogenesis-related (PR) proteins, induced in plants in response to various biotic and abiotic stresses, have been assumed to play a role in plant defense system. Proteins of the PR5 family, also named thaumatin-like proteins (TLPs), have been detected in numerous plant species. In this research, a novel PR5 gene, designated as TaPR5, was isolated and characterized from wheat leaves (cv. Suwon 11) infected by the stripe rust pathotype CY23 (incompatible interaction) using the rapid amplification of cDNA ends (RACE). TaPR5 was predicted to encode a protein of 173 amino acids with an estimated molecular mass of 17.6 kDa and a theoretical pI of 4.64. The deduced amino acid sequence of TaPR5 showed a significant sequence similarity with PR5 and TLPs from barley and other plants and contained a putative signal peptide at the amino terminus. Southern blot analysis indicated that TaPR5 is coded by a single-copy gene. Quantitative real-time polymerase chain reaction (qRT-PCR) analyses revealed that TaPR5 transcript is significantly induced and upregulated in the incompatible interaction while in the compatible interaction a relative low level of the transcript was detected. TaPR5 was also induced by phytohormones (SA, JA and ABA) and stress stimuli (wounding, cold temperature and high salinity). Using an assay of onion epidermal cells indicated accumulation of TaPR5 protein in the apoplast. The immunocytochemical method showed that the TaPR5 protein was detected on cell walls of wheat leaves in the incompatible interaction at markedly higher labeling density compared with the compatible interaction.

[Cloning and transcriptional profiling of a cell division cycle gene PsCdc2 from stripe rust fungus during incompatible and compatible interaction between wheat and Puccinia striiformis f. sp. tritici].

OBJECTIVE: We cloned a cell division cycle PsCdc2 from Puccinia striiformis f. sp. tritici (Pst) and analyze its expression profile. METHODS: Using PCR and RT-PCR methods, we isolated the cDNA and genomic DNA sequences of PsCdc2. We analyzed the amino acid sequence of PsCdc2 using bioinformatic softwares. In addition, Real time RT-PCR was used to analyze the gene expression pattern of PsCdc2 at different time points after wheat inoculated. RESULTS: A 2279 bp DNA sequence of PsCdc2 was cloned and comprised of 11 extrons and 10 introns. The cDNA sequence of PsCdc2 included a complete 885 bp open reading frame and encoded a putative protein composed of 294 amino acids, with a molecular weight of 33.14 KDa and a pI of 6.26. PsCdc2 contained two conserved kinase domains and a transmembrane domain. Phylogenetic analysis indicated that PsCdc2 showed high similarity with Cdc2 from Puccinia graminis (73.1%), Cryptococcus neoformans (72.4%) and Ustilago maydis (70.4%), respectively. Real time RT-PCR analysis showed that in compatible interaction between Pst and wheat, PsCdc2 was up-regulated at early stage of infection. The maximum induction occurred at 12 hpi, at which transcripts were 1.62 fold over that in urediniospore. From 24 to 268 hpi, the accumulation of transcripts decreased steadily. The minimum accumulation occurred at 96 h, at which transcripts were only 0.07 fold of that in uredinisopore. During incompatible interaction between Pst and wheat, PsCdc2 was down-regulated and its accumulation was lower than that in urediniospore. The maximum induction occurred at 12 h, at which transcripts were 0.34 fold of that in urediniospore. The minimum accumulation occurred at 96 h, whose transcript was only 0.02 fold of that in urediniospore. CONCLUSION: PsCdc2 might be involved in primary hyphal growth and haustorium formation during early infection by regulating cell cycle of Pst. The present study would be helpful for understanding the essence of cell cycle control and provided basis for new chemical control of Pst.

[Relationship between tea-drinking and anaemia of rural reproductive married women in a community-based cross-sectional study in China].

OBJECTIVE: To determine the prevalence of anaemia and the relationship between tea-drinking and anaemia in reproductive married women in rural China. METHOD: A cross-sectional study was carried out in four rural communities in Deqing County, Zhejiang Province, China. A total of 1425 reproductive married women at the ages of 20 to 49 years participated in this study and had a satisfactory measure of hemoglobin. Their general information, health status and lifestyle behaviors were collected. Hemoglobin was tested by Drabkin Method. Chi-square test, and binary and multinomial Logistic regression models were used for statistical analysis in SPSS 11.0. RESULT: Among 1425 subjects, the average concentration of hemoglobin were 114.7 +/- 17.0 g/L, the prevalences of anaemia were 63.3%, and most were mild and moderate anaemia (Such prevalence were 63.5%, 63.2% and 63.4% respectively at the ages of 20-30 years, 31-40 years, and 41-49 years.). Subjects with tea-drinking were higher in average concentration of hemoglobin than those of no tea-drinking (t = 3.33, P = 0.001). There were significant associations between tea-drinking and anaemia OR was 0.56 (95% CI: 0.45, 0.73). Further, such protective effects of tea-drinking were observed among subjects with different anaemia [ORs were 0.57 (95% CI: 0.43, 0.75), 0.57 (95% CI: 0.43, 0.75), and 0.28 (95% CI: 0.11, 0.70)] in mild, moderate and severe anaemia, respectively. CONCLUSION: The prevalence of anaemia in reproductive married women in rural of China could be higher and tea-drinking could be a possible protective factor.

Genome-Wide Analysis of Simple Sequence Repeats and Efficient Development of Polymorphic SSR Markers Based on Whole Genome Re-Sequencing of Multiple Isolates of the Wheat Stripe Rust Fungus.

The biotrophic parasitic fungus Puccinia striiformis f. sp. tritici (Pst) causes stripe rust, a devastating disease of wheat, endangering global food security. Because the Pst population is highly dynamic, it is difficult to develop wheat cultivars with durable and highly effective resistance. Simple sequence repeats (SSRs) are widely used as molecular markers in genetic studies to determine population structure in many organisms. However, only a small number of SSR markers have been developed for Pst. In this study, a total of 4,792 SSR loci were identified using the whole genome sequences of six isolates from different regions of the world, with a marker density of one SSR per 22.95 kb. The majority of the SSRs were di- and tri-nucleotide repeats. A database containing 1,113 SSR markers were established. Through in silico comparison, the previously reported SSR markers were found mainly in exons, whereas the SSR markers in the database were mostly in intergenic regions. Furthermore, 105 polymorphic SSR markers were confirmed in silico by their identical positions and nucleotide variations with INDELs identified among the six isolates. When 104 in silico polymorphic SSR markers were used to genotype 21 Pst isolates, 84 produced the target bands, and 82 of them were polymorphic and revealed the genetic relationships among the isolates. The results show that whole genome re-sequencing of multiple isolates provides an ideal resource for developing SSR markers, and the newly developed SSR markers are useful for genetic and population studies of the wheat stripe rust fungus.

Induction of umbilical cord blood mesenchymal stem cells into neuron-like cells in vitro.

Mesenchymal stem cells (MSCs) in human umbilical cord blood are multipotent stem cells that differ from hematopoietic stem cells. They can differentiate in vitro into mesenchymal cells such as osteoblasts and adipocytes. However, differentiation into nonmesenchymal cells has not been demonstrated. Here, we report the isolation, purification, expansion, and differentiation of human umbilical cord blood MSCs into neurocytes in vitro. Cord blood samples were allowed to drain from the end of the cord into glass bottles with 20 U/mL preservative-free heparin. MSCs were isolated from human umbilical cord blood, purified, and expanded in Mesencult medium. Surface antigens of MSCs were analyzed by fluorescence-activated cell sorting (FACS). MSC passages 2,5, and 8 were induced to differentiate into neuron-like cells. Neurofilament (NF) and neuron-specific enolase (NSE) were detected by immunohistochemistry staining. Special Nissl bodies were observed by histochemical analysis. The results showed that 6.6 x 10(5) primary MSCs were expanded for 10 passages to obtain 9.9 x 10(8) MSCs, an increase of approximately 1.5 x 10(3)-fold. FACS results showed that the MSCs did not express antigens CD34, CD11a, and CD11b and expressed CD29 and CD71, an expression pattern identical to that of human bone marrow-derived MSCs. Induction results indicated that approximately 70% of the cells exhibited a typical neuron-like phenotype. Immunohistochemistry staining suggested that induced MSCs of different passages expressed NF and NSE. Special Nissl bodies were obvious in the neuron-like cells. These results suggest that MSCs in human umbilical cord blood are capable of differentiating into neuron-like cells in vitro.

[Teratosis and damage of viscera induced by microcystin in SD rat fetuses].

OBJECTIVE: To study the teratogenicity and traumatic effect of microcystin LR (MCLR) on pregnant SD rats and their fetuses. METHODS: Sixty pregnant SD rats were divided into four groups, 16 in each group: three experimental groups in which MCLR was injected into the abdominal cavity at the doses of 4 microgram/kg, 16 microgram/kg, and 62 microgram/kg respectively for 10 days, and control group injected with normal saline. Twenty days after, the pregnant rats were killed. The development, teratosis, and histology of viscera of the fetuses were examined. RESULTS: Deformities were found in the fetuses of the 62 microgram/kg group and 16 microgram/kg group with the teratogenic rate of 11.70 per thousand (2/172) and 6.76 per thousand (1/155). Petechial hemorrhage and severe hydropic degeneration in liver and maldevelopment of glomeruli and renal medulla were found in 62 microgram/kg group. Mild granular degeneration was found in the liver of fetuses in 4 microgram/kg group. CONCLUSION: MCLR passes through the placental barrier and causes damage in kidney and liver, which may be the basis of high incidence of liver cancer microgram in the fetus phase.

Study on the distribution of nodularin in tissues and cell level in mice.

OBJECTIVES: To study the tissue distribution of nodularin in mice and the cellular location of nodularin in the target organs. METHODS: The nodularin was labeled with radioactive isotope (125)I and then was given to mice via oral, intraperitoneal and intravenous administration. The distribution of nodularin in target organs and the cellular location of nodularin were studied by radioisotope and autoradiography techniques. RESULTS: The radioisotope study results showed that nodularin was mainly distributed in the kidney and liver in mice. Further autoradiography study indicated that nodularin was distributed in the renal cell nuclei and liver cell nuclei. CONCLUSION: The kidney and liver are the two main target organs for nodularin in mice.

[The acute toxic effects of microcystin LR in SD rats].

OBJECTIVE: To assess Microcystin LR (MCLR)-induced acute toxic effects in male Sprague-Dawley rats. METHODS: The rats were injected with MCLR intraperitoneally in different doses for different days. The organs and serum with rats were collected at 1 and 7 days after injection, and 7 days after the final injection (total 14 days). Pathological and enzymatic changes were observed. RESULTS: The rats injected with 122 microg/kg MCLR showed myocardial cells damage including pyknosis, plasma dissolve and myofibrilla (pls check with dictionary) necrosis in the heart muscles after 24 hours. At the same time, the activities of serum glutamate-oxaloacetate transaminase (GOT), lactate dehydrogenase (LDH) and creatine phosphonase (CPK) were higher than these in the other groups (P < 0.01). The kidney was also damaged, kidney cell degeneration, and the increase of blood creatine (BCr) and blood urea nitrogen (BUN) were also seen. In liver pathological study, liver cell hemorrhage, degeneration and/or necrosis was observed. In serum the activities of glutamate-pyruvate transaminase (GPT), alkaline phosphatase (LDH) and GOT were higher than these in the other groups (P < 0.01). CONCLUSION: These results suggested that MCLR can injure the heart, kidney and the liver in SD rats, and there is a dose-response relationship between MCLR and the toxic effect.

Glycerol-3-phosphate metabolism in wheat contributes to systemic acquired resistance against Puccinia striiformis f. sp. tritici.

Glycerol-3-phosphate (G3P) is a proposed regulator of plant defense signaling in basal resistance and systemic acquired resistance (SAR). The GLY1-encoded glycerol-3-phosphate dehydrogenase (G3PDH) and GLI1-encoded glycerol kinase (GK) are two key enzymes involved in the G3P biosynthesis in plants. However, their physiological importance in wheat defense against pathogens remains unclear. In this study, quantification analysis revealed that G3P levels were significantly induced in wheat leaves challenged by the avirulent Puccinia striiformis f. sp. tritici (Pst) race CYR23. The transcriptional levels of TaGLY1 and TaGLI1 were likewise significantly induced by avirulent Pst infection. Furthermore, knocking down TaGLY1 and TaGLI1 individually or simultaneously with barley stripe mosaic virus-induced gene silencing (BSMV-VIGS) inhibited G3P accumulation and compromised the resistance in the wheat cultivar Suwon 11, whereas the accumulation of salicylic acid (SA) and the expression of the SA-induced marker gene TaPR1 in plant leaves were altered significantly after gene silencing. These results suggested that G3P contributes to wheat systemic acquired resistance (SAR) against stripe rust, and provided evidence that the G3P function as a signaling molecule is conserved in dicots and monocots. Meanwhile, the simultaneous co-silencing of multiple genes by the VIGS system proved to be a powerful tool for multi-gene functional analysis in plants.