Clinical and radiological characteristics of COVID-19: a multicentre, retrospective, observational study.

BACKGROUND: Multicentre cohort investigations of patients with coronavirus disease 2019 (COVID-19) have been limited. We investigated the clinical and chest computed tomography characteristics of patients with COVID-19 at the peak of the epidemic from multiple centres in China. METHODS: We retrospectively analysed the epidemiologic, clinical, laboratory, and radiological characteristics of 189 patients with confirmed COVID-19 who were admitted to seven hospitals in four Chinese provinces from 18 January 2020 to 3 February 2020. RESULTS: The mean patient age was 44 years and 52.9% were men; 186/189 had ≥1 co-existing medical condition. Fever, cough, fatigue, myalgia, diarrhoea, and headache were common symptoms at onset; hypertension was the most common co-morbidity. Common clinical signs included dyspnoea, hypoxia, leukopenia, lymphocytopenia, and neutropenia; most lesions exhibited subpleural distribution. The most common radiological manifestation was mixed ground-glass opacity with consolidation (mGGO-C); most patients had grid-like shadows and some showed paving stones. Patients with hypertension, dyspnoea, or hypoxia exhibited more severe lobe involvement and diffusely distributed lesions. Patients in severely affected areas exhibited higher body temperature; more fatigue and dyspnoea; and more manifestations of multiple lesions, lobe involvement, and mGGO-C. During the Wuhan lockdown period, cough, nausea, and dyspnoea were alleviated in patients with newly confirmed COVID-19; lobe involvement was also improved. CONCLUSIONS: Among patients with COVID-19 hospitalised at the peak of the epidemic in China, fever, cough, and dyspnoea were the main symptoms at initial diagnosis, accompanied by lymphocytopenia and hypoxaemia. Patients with severe disease showed more severe lobe involvement and diffuse pulmonary lesion distribution.

Using magnetic resonance diffusion tensor imaging to evaluate renal function changes in diabetic patients with early-stage chronic kidney disease.

AIM: To investigate the clinical value of diffusion tensor imaging (DTI) in assessing renal function changes in diabetic patients with early-stage chronic kidney disease (CKD), and the relationship of DTI parameters with estimated glomerular filtration rate (eGFR) and urinary biomarkers. MATERIALS AND METHODS: Thirty-six patients with diabetes mellitus (DM; 30 CKD stage 1 and 6 CKD stage 2) and 26 healthy control subjects were enrolled. DTI was performed using a clinical 3 T MRI system. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) values were calculated from the renal cortex and medulla. The correlation of the DTI parameters with eGFR and urinary biomarkers was evaluated. RESULTS: FA values were significantly reduced in the renal cortex and medulla of DM group compared with the control group (cortical FA, Z=-2.834, p=0.005; medullary FA, t=2.768, p=0.007). In the DM group, FA values in the renal cortex and medulla were positively correlated with eGFR, while FA values in the medulla were negatively correlated with the urinary albumin/creatinine ratio, urinary alpha-1 microglobulin/creatinine ratio, and urinary transferring/creatinine ratio. ADC values in the renal cortex and medulla showed a trend towards an increase in the DM group compared with the control group. CONCLUSIONS: Renal DTI is a promising method for assessing early renal function changes in DM patients.

[The MRI analysis of 220 cases of placenta previa complicated with placenta accrete or not].

Objective: To investigate the diagnostic value of MRI for placenta previa complicated with placenta accreta or not. Methods: A total of 220 placenta previa patients were diagnosed by prenatal ultrasound and MRI in The Second Affiliated Hospital of Wenzhou Medical University from May 2014 to May 2017.The MRI images of 220 placenta previa patients suspicious of placenta previa were interpreted by two radiologists who majored on gynecological radiology. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of two radiologists in diagnosis of placenta accreta were calculated respectively. Kappa test were used to verify the consistency between two doctors, as well as their MRI diagnosis and pathological results. The diagnostic value of MRI and pathological were assessed by Chi-square test and receiver operating characteristic (ROC)curve. Results: The 220 patients were all confirmed with placenta previa by surgical pathology.Out of 220, 71 cases were diagnosed as placenta accreta, and 149 cases were diagnosed without placenta accreta. The sensitivity, specificity, accuracy, positive predictive value and negative predictive value with physician A and physician B were 90.1%/84.5%, 88.6%/89.9%, 89.1%/88.2%, 79.0%/80.0% and 95.0%/92.4%, respectively.The consistency between MRI diagnosis and pathological results was excellent in physician A (κ=0.759), and good in physician B (κ=0.734). However, the sensitivity, specificity and accuracy of diagnosis between two physicians had no significant difference (all P>0.05). The area under the curve (AUC) of ROC in physician A and B were 0.858 and 0.847 (P=0.980). Conclusion: MRI is feasible for patients with placenta previa, as the sensitivity, specificity and accuracy of MRI are high in assessing whether placenta previa complicated with placenta accreta or not.

Evaluation of panels of Mycobacterium tuberculosis antigens for serodiagnosis of tuberculosis.

OBJECTIVE: To evaluate antibody responses to panels of Mycobacterium tuberculosis antigens for serological diagnosis of active tuberculosis (TB). DESIGN: We cloned, expressed and purified 10 M. tuberculosis recombinant proteins 38KD, MPT32 (M. tuberculosis protein 32), MPT64, EspC (ESX-1 secretion-associated protein), Mtb81, Rv3881, Rv3425, Rv0222, Rv3872 and CFP21 (culture filtrate protein 21), and obtained lipoarabinomannan (LAM) polysaccharide antigen from BEI Resources. The plasma immunoglobulin (Ig)G titre responses to the 11 antigens based on 45 patients with pulmonary TB (PTB) and 30 healthy controls (HCs) were first evaluated using enzyme-linked immunosorbent assays. Antigens with high sensitivities were then selected for further investigation in 200 PTB patients (121 smear- or culture-positive patients, 79 smear- or culture-negative patients) and 152 HCs. RESULTS: LAM, 38KD, MPT32, MPT64, EspC and Mtb81 were chosen. The LAM, 38KD, MPT32 and EspC IgG titres were significantly higher in Bacterium-negative TB patients than in HCs, except for MPT64 and Mtb81. The sensitivity of the individual antigens for detecting antibodies ranged from 21.5% to 67.0%, with 74.3-98.0% specificity. The sensitivity of MPT32 was higher than that of 38KD at a high level of specificity. The six-antigen combination reached a sensitivity of 69.6% in bacterium-negative TB patients, with 77.0% specificity. CONCLUSION: The combination panel had markedly improved sensitivity, but specificity requires further enhancement.

[Effect of data missing on population based viral load survey in HIV infected men who have sex with men sampled in 16 large cities, China].

Objective: To analyze the effect of missing data in population based viral load (PVL) survey in HIV infected men who have sex with men (MSM) sampled in 16 cities in China. Methods: The database of 3 virus load sampling survey conducted consecutively in HIV infected MSM population in 16 large cities (Beijing, Shanghai, Nanjing, Hangzhou, Wuhan, Chongqing, Kunming, Xi'an, Guangzhou, Shenzhen, Nanning, Urumuqi, Harbin, Changchun, Chengdu and Tianjin) during 2013-2015 was used. SPSS 17.0 software was used to describe distribution of the missing data and analyze associated factors. Results: A total of 12 150 HIV infected MSM were randomly selected for the surveys, in whom, 9 141 (75.2%) received virus load tests, while 3 009 (24.8%) received no virus load tests, whose virus load data missed. The virus load data missing rates in MSM with or without access to antiretroviral therapy (ART) were 11.5% (765/6 675) and 39.4% (2 060/5 223) respectively, and the virus load data missing rates were 21.9% (1 866/8 523) and 28.4% (959/3 374), respectively, in local residents and non-local residents (migrants). Conclusions: The analysis indicated that the data missing occurred in the virus load survey in HIV infected MSM population. ART status and census registering status were the main influencing factors. Data missing could influence the accurate evaluation of community viral load (CVL) and population viral load(PVL) levels in HIV infected MSM in China.

[Recombinant human tumor necrosis factor receptor type â ¡-IgG Fc fusion protein for treatment of occupational medicamentosa-like dermatitis induced by trichloroethylene].

Objective: To investigate the efficacy and safety of the recombinant human tumor necrosis factor receptor Ⅱ-IgG Fc fusion protein (rhTNFR: Fc, etanercept) for the treatment of occupational medicamentosa-like dermatitis induced by trichloroethylene (OMLDT) . Methods: In September 2011 to February 2016, 12 patients with OMLDT were treated with etanercept 25 mg, subcutaneous injection, twice per week, doubling of first dose. The course of treatment was 6 weeks. The drug eruption area and severity index (DASI) score, the proportion of patients achieving a 50%, 75% and 90% reduction in DASI (DASI50, DASI75, DASI90) and the serum level of TNF-α were used to assess the efficacy at different times. Adverse reactions were also recorded and evaluated. The results were statistically analyzed by nonparametric Friedman test and repetitive measurement ANOVA using the software SPSS19.0. Results: After 4 weeks treatment, the DASI score decreased form 56.33±7.02 to 0.50±0.91 (P<0.01) . The DASI50, DASI75 and DASI90 were all increased to 12 (100%) . The serum level of TNF-α decreased form (43.74±41.62) pg/ml to (3.03±0.47) pg/ml (P<0.01) . Statistically significant difference was observed from the above indexes. There were no adverse reactions in clinical application. Conclusion: Recombinant human tumor necrosis factor receptor Ⅱ-IgG Fc fusion protein may be a safe and effective drug in the treatment of OMLDT.

[Effect of intranasal excision on nasal vestibular cyst under nasal endoscopy].

Objective: To observe the clinical effects of intranasal excision on nasal vestibular cyst under nasal endoscopy. Methods: Forty-two cases of nasal vestibular cyst diagnosed in the Department of Otorhinolaryngology Head and Neck Surgery, Tianjin Third Central Hospital between Feb. 2011 and Jan. 2016 were treated by intranasal excision under nasal endoscope. Results: All the 42 patients were cured without any complication. The rate of complete stripping was 78.6% (33/42), with operating time of (21.31±4.04) min and bleeding amount of (10.26±2.13) ml. During follow-up ranged from 6 months to 5 years, with the median follow-up time being 19.6 months, no post-operative recurrence and complication were found. Conclusion: Intranasal excision for nasal vestibular cyst under nasal endoscopy is an effective method, which can be widely used in hospitals.

CD137 is a Useful Marker for Identifying CD4+ T Cell Responses to Mycobacterium tuberculosis.

Upregulation of CD137 on recently activated CD8+ T cells has been used to identify rare viral and tumour antigen-specific T cells from the peripheral blood. We aimed to evaluate the accuracy of CD137 for identifying Mycobacterium tuberculosis (Mtb)-reactive CD4+ T cells in the peripheral blood of infected individuals by flow cytometry and to investigate the characteristics of these CD137+ CD4+ T cells. We initially enrolled 31 active tuberculosis (TB) patients, 31 individuals with latent TB infection (LTBI) and 25 healthy donors. The intracellular CD137 and interferon-γ (IFN-γ) production by CD4+ T cells was simultaneously detected under unstimulated and CFP10-stimulated (culture filtrate protein 10, a Mtb-specific antigen) conditions. In unstimulated CD4+ T cells, we found that the CD137 expression in the TB group was significantly higher than that in the LTBI group. Stimulation with CFP10 largely increased the CD4+ T cell CD137 expression in both the TB and LTBI groups. After CFP10 stimulation, the frequency of CD137+ CD4+ T cells was higher than that of IFN-γ+ CD4+ T cells in both the TB and LTBI groups. Most of the CFP10-activated IFN-γ-secreting cells were CD137-positive, but only a small fraction of the CD137-positive cells expressed IFN-γ. An additional 20 patients with TB were enrolled to characterize the CD45RO+ CCR7+ , CD45RO+ CCR7- and CD45RO- subsets in the CD137+ CD4+ T cell populations. The Mtb-specific CD137+ CD4+ T cells were mainly identified as having an effector memory phenotype. In conclusion, CD137 is a useful marker that can be used for identifying Mtb-reactive CD4+ T cells by flow cytometry.

[Establishment and evaluation of a rat model of diabetes comorbid depression and its expression of glial fibrillary acidic protein in the brain].

OBJECTIVE: To establish and evaluate a rat model of diabetes comorbid depression, and observe alterations in expression of glial fibrillary acidic protein (GFAP) in several cerebral regions. METHODS: Eighteen Wistar rats were randomly divided into three groups, the control group (group CON, n=6), the diabetes mellitus group (group DM, n=6), and the diabetes comorbid depression group (group DD, n=6). Rats of group DM and group DD were injected intraperitoneally with STZ (64 mg/kg), the control rats received sham injections of citrate buffer alone. Group DD was then exposed to chronic unpredictable mild stress for 28 days. All rats were submitted to the open-field test and Morris water maze test immediately after the CUMS procedure. After brain tissue collection, the expression of GFAP in bilateral frontal cortex, hippocampus and hypothalamus were measured by immunohistochemistry. RESULTS: Rats of group DD and group DM exhibited classic diabetic signs of weight loss, hyperphagia, polydipia, gloomy hair and increasing urine and stool, group DD showed mental fatigue and slow response.The STZ-treated groups showed high blood glucose level (>33.3 mol/L) compared to the control group throughout the study. Group DD ((176± 11), (157±8), (154± 12)g)and group DM ((176±10), (161±8), (160±13)g)showed decline on body weight, whereas group CON ((245±14), (276±21), (314±25)g)showed continuously elevated body weight 0, 14, 28 days after CUMS.In behavioral tests, group DD ((4.1±3.1), (115±73), (26±13))showed reduced total traveling distance, activity time and times of locomotion compared to group CON ((9.3±3.2), (200±53), (40±11), P<0.05). Throughout the probe trial of Morris water maze test, group DD and group DM ((0.5±0.5), (0.5±0.6))performed less times of crossing the former platform area compared to group CON ((2.6±2.2), P<0.05). The mean optical density (MOD) of GFAP positive cells in frontal cortex, hippocampus and hypothalamus of group DD ((0.18±0.03), (0.19±0.02), (0.21±0.02)) were decreased compared with group DM ((0.26±0.03), (0.27±0.03), (0.30±0.04), P<0.01), but increased compared with group CON ((0.13±0.04), (0.15±0.02), (0.16±0.03), P<0.05 or P<0.01). CONCLUSION: Combination of intraperitoneally STZ injection and proper CUMS procedure can successfully build a rat model of diabetes comorbid depression. The expression of GFAP in bilateral frontal cortex, hippocampus and hypothalamus of group DD is significant different form group DM and group CON, which is helpful for understanding the pathogenesis of diabetes comorbid depression.

[Diffusion-weighted imaging characteristics of uterine leiomyomas with different pathological subtypes at 3.0 T].

OBJECTIVE: To investigate the imaging features of uterine leiomyomas with different pathological subtypes on DWI. METHODS: Clinical records and MR images of pathologically confirmed uterine leiomyomas were retrospectively collected from the Second Affiliated Hospital of Wenzhou Medical University from June 2012 to April 2015. A total of 60 uterine leiomyomas were found and evaluated.All the patients were divided into three groups according to different pathological types, which included 17 cases of cellular leiomyomas, 10 cases of degenerated leiomyomas and 33 cases of ordinary leiomyomas.The DWI signal and ADC values in cellular portion of the lesions and adjacent normal myometrium (the control group) were measured. RESULTS: (1) Most cellular leiomyomas showed hyperintensity on DWI (15/17), while degenerated leiomyomas manifested hypointensity, isointensity or hyperintensity signal on DWI, and most ordinary leiomyomas displayed isointensity signal on DWI (57.6%, 19/33). (2) The ADC values of cellular leiomyomas, degenerated leiomyomas and ordinary leiomyomas were (1.01±0.14)×10(-3) mm(2)/s, (1.73±0.49)×10(-3) mm(2)/s and (1.38±0.22)×10(-3) mm(2)/s respectively.The ADC values of adjacent normal myometrium (the control group) were (1.35±0.16)×10(-3) mm(2)/s.There were no significant statistical differences in the ADC values between ordinary leiomyomas and adjacent normal myometrium (P=0.623). There were significant statistical differences in the ADC values among other groups(all P<0.05). (3)The ROC curve showed that the diagnostic threshold for cellular leiomyomas was 1.11×10(-3) mm(2)/s, the sensitivity and specificity were 88.2%and 93.0% respectively. CONCLUSION: The signal intensity on DWI and the ADC values are different in uterine leiomyomas with different pathological subtypes.Combination of these two parameters in clinical practice may be helpful to reflect the histopathological characteristics of uterine leiomyomas.

TaALMT1 promoter sequence compositions, acid tolerance, and Al tolerance in wheat cultivars and landraces from Sichuan in China.

Previous genetic studies on wheat from various sources have indicated that aluminum (Al) tolerance may have originated independently in USA, Brazil, and China. Here, TaALMT1 promoter sequences of 92 landraces and cultivars from Sichuan, China, were sequenced. Five promoter types (I', II, III, IV, and V) were observed in 39 cultivars, and only three promoter types (I, II, and III) were observed in 53 landraces. Among the wheat collections worldwide, only the Chinese Spring (CS) landrace native to Sichuan, China, carried the TaALMT1 promoter type III. Besides CS, two other Sichuan-bred landraces and six cultivars with TaALMT1 promoter type III were identified in this study. In the phylogenetic tree constructed based on the TaALMT1 promoter sequences, type III formed a separate branch, which was supported by a high bootstrap value. It is likely that TaALMT1 promoter type III originated from Sichuan-bred wheat landraces of China. In addition, the landraces with promoter type I showed the lowest Al tolerance among all landraces and cultivars. Furthermore, the cultivars with promoter type IV showed better Al tolerance than landraces with promoter type II. A comparison of acid tolerance and Al tolerance between cultivars and landraces showed that the landraces had better acid tolerance than the cultivars, whereas the cultivars showed better Al tolerance than the landraces. Moreover, significant difference in Al tolerance was also observed between the cultivars raised by the National Ministry of Agriculture and by Sichuan Province. Among the landraces from different regions, those from the East showed better acid tolerance and Al tolerance than those from the South and West of Sichuan. Additional Al-tolerant and acid-tolerant wheat lines were also identified.

Upregulation of DLX2 confers a poor prognosis in glioblastoma patients by inducing a proliferative phenotype.

The human Distal-less Homeobox (DLX) gene family encodes homeobox transcription factors involved in the control of morphogenesis and tissue homeostasis, which is primarily expressed in embryonic development. Recently, DLX gene family was reported to have essential roles in carcinogenesis. We have profiled whole genome expressed genes in 83 glioblastoma multiforme (GBM) patients from the Chinese Glioma Genome Atlas (CGGA) Group. Two major groups of samples were identified in mRNA expression profiles (referred to as Cluster 1 (C1) and Cluster 2 (C2)). We identified 7 out of the top 10 Gene Ontology terms in the C1 group were associated with differentiation and development of neuronal cell. The most significant prognostic gene was DLX2 (P < 0.001, OR = 1.744); overexpression of DLX2 indicated poor survival in the 83 GBM patients (low DLX2 vs high DLX2, 77.6 vs 44.7 weeks, P < 0.001). Annotation of mRNA profiling data on GBM from The Cancer Genome Atlas and MD Anderson Cancer Center showed the proneural and neural subtypes highly correlated with low and high DLX2 expression, respectively. Knocking down of DLX2 in GBM cell line-LN229 results in decreased cyclin D1 expression and cell proliferation. Collectively, these data identified high expression of DLX2 as a poor prognostic marker to GBM patients.

Assessment of in vivo estrogenic response and the identification of environmental estrogens in the Yangtze River (Nanjing section).

Environmental estrogens in the aquatic environment have been shown to be responsible for the feminization of fish. The estrogenic content of the Yangtze River (Nanjing section--referred to as the studied area herein) was assessed using a combination of bioassay and chemical analysis. The in vivo bioassay was conducted by exposing adult male goldfish (Carassius auratus) to different concentrations of river water (25%, 50% and 100%) sampled from three representative sections of the studied area. Chemical analysis of estrogens in water from the three representative sections was conducted using solid phase extraction-gas chromatograph (SPE-GC) detection. The assay showed significant serum vitellogenin (VTG) and 17beta-estradiol (E2) induction and gonad atrophy in the treated fish. The strength of in vivo estrogenic responses in the three representative sections is in the order of Jiangxinzhou section>Daqiao section>Sanchahe section. The result is consistent with the levels of water estrogens determined from the chemical analysis. Steroidal estrogens were the major causal agents responsible for the estrogenic responses in the Jiangxinzhou and Daqiao sections, while phenolic estrogens were the main contributors in the Sanchahe section. The results of these in vivo bioassay and chemical analysis demonstrate that fish in the Yangtze River are exposed to environmental estrogens and are at a risk of feminization.

Molecular characterization of novel low-molecular-weight glutenin genes in Aegilops longissima.

Extensive genetic variations of low-molecular-weight glutenin subunits (LMW-GS) and their coding genes were found in the wild diploid A- and D-genome donors of common wheat. In this study, we reported the isolation and characterization of 8 novel LMW-GS genes from Ae.longissima Schweinf. & Muschl., a species of the section Sitopsis of the genus Aegilops, which is closely related to the B genome of common wheat. Based on the N-terminal domain sequences, the 8 genes were divided into 3 groups. A consensus alignment of the extremely conserved domains with known gene groups and the subsequent cluster analysis showed that 2 out of the 3 groups of LMW-GS genes were closely related to those from the B genome, and the remaining was related to those from A and D genomes of wheat and Ae. tauschii. Using 3 sets of gene-group-specific primers, PCRs in diploid, tetraploid and hexaploid wheats and Ae. tauschii failed to obtain the expected products, indicating that the 3 groups of LMW-GS genes obtained in this study were new members of LMW-GS multi-gene families. These results suggested that the Sitopsis species of the genus Aegilops with novel gene variations could be used as valuable gene resources of LMW-GS. The 3 sets of group-specific primers could be utilized as molecular markers to investigate the introgression of novel alien LMW-GS genes from Ae. longissima into wheat.

Length variations of i-type low-molecular-weight glutenin subunit genes in diploid wheats.

Allelic variation of the low-molecular-weight glutenin subunit (LMW-GS) is associated with the significant differences of dough quality in bread and durum wheat, and has been widely evaluated at protein level in wheat and its relatives. In this study, a PCR primer set, targeting the high variable repetitive domains, was employed to assay the length variation of i-type LMW-GS genes in the A-genomes of diploid wheats, the diploid progenitors of tetraploid and hexaploid wheat. A total of 71 accessions of diploid wheats, belonging to two wild and one cultivated species, were investigated. The higher variations of repetitive length in i-type LMW-GS genes were found in diploid wheats with Nei's genetic variation index (H) of 0.834. The two wild species, T. boeoticum and T. urartu, were found to possess the similar degree of variability, with the Nei's genetic variation index of 0.806 and 0.783, respectively. Less variations were detected in T. monococcum (H = 0.680), a cultivated species domesticated from T. boeoticum. The sufficient variations found in this study could be used as valuable sources for the enrichment of the genetic variations and the alteration of flour-processing properties of the cultivated wheat. To our knowledge, it was the first time that an analysis of length variation targeting a particular group of genes of LMW-GS complex multigene families was conducted.

Characterization of alpha-gliadin genes from diploid wheats and the comparative analysis with those from polyploid wheats.

To carry out the comparative analysis of alpha-gliadin genes on A genomes of diploid and polyploid wheats, 8 full-length alpha-gliadin genes, including 3 functional genes and 5 pseudogenes, were obtained from diploid wheats, among which 2, 2 and 4 alpha-gliadin genes were isolated from T. urartu, T. monococcum and T. boeoticum, respectively. The results indicated that higher number of alpha-gliadin pseudogenes have been present in diploid wheats before the formation of polyploid wheats. Amino acid sequence comparative analysis among 26 alpha-gliadin genes, including 16 functional genes and 10 pseudogenes, from diploid and polyploid wheats was conducted. The results indicated that all alpha-gliadins contained four coeliac toxic peptide sequences (i.e., PSQQ, QQQP, QQPY and QPYP). The polyglutamine domains are highly variable, and the second polyglutamine stretch is usually disrupted by the lysine or arginine residue at the fourth position. The unique domain I is the most conserved domain. There are 4 and 2 conserved cysteine residues in the unique domains I and II, respectively. Comparative analysis indicated that the functional alpha-gliadin genes from A genome are highly conserved, whereas the identity of pseudogenes in diploid wheats are higher than those in hexaploid wheats. Phylogenetic analysis indicated that all the analyzed functional alpha-gliadin genes could be clustered into two major groups, among which one group could be further divided into 5 subgroups. The origin of alpha-gliadin pseudogene and functional genes were also discussed.

[Biochemical and molecular characterization of gliadins].

Gliadins account for about 40-50% of the total proteins in wheat seeds and play an important role on the nutritional and processing quality of flour. Usually, gliadins could be divided into alpha- (alpha/beta-), gamma- and omega-groups, whereas the low-molecular-weigh (LMW) gliadins were novel seed storage proteins. The low-molecular-weight glutenin subunits (LMW-GSs) were also designated as gliadins in a few literatures. The genes encoding gliadins were mainly located on the short arms of group 6 and group 1 chromosomes, and not evenly distributed. Repetitive sequences covered most of un-coding regions, which attributed greatly to the evolution of wheat genome. Primary structure of each gliadin has been divided into several domains, and the long repetitive domains consisted of peptide motifs. Conserved cysteine residues mainly formed intramolecular disulphide bonds. The rare potential intermolecular disulphide bonds and the long repetitive domains played an important role in the wheat flour quality. There was a general idea that gliadin genes, even prolamin genes, have a common origin and subsequent divergence lead to the gene polymorphism. The gamma-gliadins have been considered to be the most ancient of the wheat prolamin family. Several elements in the 5'-flanking (e.g. CAAT and TATA box) and the 3'-flanking sequences had been detected, which had been shown necessary for the proper expression of gliadins.

Genetic diversity of Triticum turgidum L. based on microsatellite markers.

Using microsatellite (SSR) markers, the genetic diversity and genetic relationships among 48 Triticum turgidum L. accessions, including 30 Triticum turgidum L. ssp. turgidum, 7 Triticum turgidum L. ssp. durum, 4 Triticum turgidum L. ssp. carthlicum, 3 Triticum turgidum L. ssp. paleocolchicum, 2 Triticum turgidum L. ssp. turanicum and 2 Triticum turgidum L. ssp. polonicum accessions, were investigated. A total of 97 alleles were detected on 16 SSR loci. At each locus, the number of alleles ranged from 2 to 14, with an average of 6.1. The Genetic similarity (GS) value ranged from 0.20 to 0.92, with the mean of 0.59. In cluster analysis, it was found the 48 Triticum turgidum L. accessions could be distinguished easily by SSR markers, whereas the 6 subspecies taxonomic entities of T. turgidum L. could not differentiate with each other, indicating that the morphological differences present among the 6 subspecies could not be reflected by the SSR markers. These results suggested that SSR markers had the superiority in detecting the genetic diversity of T. turgidum L., while it was not good for the studies of the phylogenic relationships among the subspecies of T. turgidum L.

Identification of LMW glutenin-like genes from Secale sylvestre host.

Three low-molecular-weight (LMW) glutenin-like genes (designated as Ssy1, Ssy2 and Ssy3) from Secale sylvestre Host were isolated and characterized. The three genes consist of a predicted highly conservative signal peptide with 20 amino acids, a short N-terminal region with 13 amino acids, a highly variable repetitive domain and a less variable C-terminal domain. The deduced amino acid sequences of the three genes were the LMW-m type due to a methionine residue at the N-terminus. The phylogenic analysis indicated that the prolamin genes could be perfectly clustered into five groups, including HMW-GS, LMW-GS, alpha/beta-, gamma- and omega-prolamin. The LMW glutenin-like genes of S. sylvestre were more orthologous with the LMW-GS genes of wheat and B hordein genes of barley, which also had been confirmed by the homology analysis with the LMW-GS of wheat at Glu-A3, Glu-B3 and Glu-D3 loci. These results indicated that a chromosome locus (designated as Glu-R3) might be located on the R genome of S. sylvestre with the functions similar to the Glu-3 locus in wheat and its related species.