The value of quantitative contrast-enhanced ultrasonography analysis in evaluating central retinal artery microcirculation in patients with diabetes mellitus: comparison with colour Doppler imaging

AIM

To compare the efficacy of quantitative contrast-enhanced ultrasonography (CEUS) analysis and colour Doppler ultrasound (CDU) in evaluating central retinal artery (CRA) microcirculation in patients with diabetes mellitus (DM).

MATERIALS AND METHODS

In this prospective study, a total of 55 patients (98 eyes) with DM were enrolled as the study group. They were compared to 46 age-matched healthy volunteers (92 eyes) who were selected as the control group. Each patient underwent CDU and subsequent CEUS examination. CDU and quantitative CEUS parameters were evaluated. The diagnostic efficiency of the diagnostic performance of CEUS and CDU was evaluated and compared, and the scale thresholds of predictive indicators for the diagnosis of proliferative diabetic retinopathy (PDR) were evaluated using receiver operating characteristics (ROC) curve analyses.

RESULTS

Group pairwise comparisons showed that the end diastolic velocity (EDV) and arrival time (AT) of CRA were significant predictors for PDR by CDU and by quantitative CEUS analysis, respectively (all p<0.05). The ROC curve analysis showed that the area under the curve value of AT was significantly higher than that of EDV (0.875 versus 0.634, p=0.0002). Accordingly, an AT cut-off value of 1.07 seconds resulted a sensitivity of 90.62 % and a specificity of 79.31 %.

CONCLUSION

Quantitative CEUS analysis can improve the accuracy of clinical staging of diabetic retinopathy for the patients with DM, and the AT showed the best diagnostic efficiency.

[Wine-processed Chuanxiong Rhizoma enhances efficacy of aumolertinib against EGFRmutant non-small cell lung cancer xenografts in nude mouse brain]

OBJECTIVE

To investigate the effect of wine-processed Chuanxiong Rhizoma (WCR) for enhancing the efficacy of aumolertinib against xenografts of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) in the brain of nude mice.

METHODS

In a co-culture system of hCMEC/D3 and PC9 NSCLC cells, the effect of aqueous extract of WCR (2 mg/mL) combined with aumolertinib (10 and 20 μmol/L) on apoptosis of PC9 cells was investigated using flow cytometry. The effects of WCR extract (0.5, 1, and 2 mg/mL) on transmembrane transport of 8 μmol/L aumolertinib was examined in ABCB1-MDCK monolayer cells. Western blotting was used to detect the expressions of the tight junction proteins related with blood- brain barrier integrity. A nude mouse model bearing NSCLC xenograft in the brain was established to observe the inhibitory effect of WCR (1 mg/g) combined with aumolertinib (10 mg/kg) on tumor growth.

RESULTS

Compared with aumolertinib (20 μmol/L) alone, WCR extract (2 mg/mL) combined with aumolertinib significantly increased the apoptosis rate of PC9 cells by 21% (P < 0.01). The combined treatment with WCR (0.5, 1, 2 mg/mL) obviously increased apical-basolateral transport of aumolertinib in ABCB1-MDCK monolayer cells (P < 0.05) and significantly lowered the expression levels of zonula occludens-1, claudin-5 and P-glycoprotein (P < 0.05). In the tumor-bearing mice, compared with aumolertinib alone, the combined treatment with WCR and aumolertinib produced stronger inhibitory effect on tumor growth, improved weight loss, and prolonged the survival time of the nude mice (P < 0.05). Pathological examination showed that the combined treatment obviously increased the apoptosis rate of the tumor cells and alleviated neural injuries in the brain. Immunohistochemistry revealed that WCR treatment significantly reduced the expressions of ZO-1 and claudin-5 in the brain of the mice.

CONCLUSION

WCR combined with aumolertinib shows stronger inhibitory effects against tumor xenografts of EGFR-mutant NSCLC possibly due to the effect of WCR in facilitating the transmembrane transport of aumolertinib by downregulating ZO-1, claudin-5 and P-glycoprotein expression.

Biocrust diazotrophs and bacteria rather than fungi are sensitive to chronic low N deposition

Anthropogenic long-term nitrogen (N) deposition may dramatically impact biocrusts due to the overarching N limitation of soil biota in deserts. Even low levels of N may reach a critical loading threshold altering biocrust constituents and function. To identify the impact of chronic and continuous low levels of N deposition on biocrusts, we created a realistic gradient mirroring anthropogenic N addition rate (2:1 NH₄ ⁺ : NO₃ ^- rates: 0.3, 0.5, 1.0, 1.5, 3 g N m^-2  yr^-1 ) and measured the response of bacteria and fungi within cyanobacterial-dominated biocrusts over 8 years in a temperate desert, the Gurbantunggut Desert, China. We found that once N deposition reached 1.5 g N m^-2  yr^-1 biocrust bacterial communities, including diazotrophs, were altered while no such tipping point existed for fungi. Above the threshold, bacterial richness was enhanced, the relative abundance of Chloroflexi, FBP and Gemmatimonadetes was elevated, and diazotrophs shifted from being dominated by Nostocaceae and Scytonemataceae (Cyanobacteria) to free-living Bradyrhizobiaceae (Alphaproteobacteria). Alternatively, the relative recovery of a few fungal species within the Lecanorales, Pleosporales and Verrucariales became either enriched or diminished due to N deposition. The chronic addition of N resulted in a dense and interconnected bacterial co-occurrence network that accentuated a functional shift from networks dominated by phototrophic species within the Nostocaceae, Xenococcaceae, Phormidiaceae and Scytonemataceae (Cyanobacteria) to ammonia-oxidizing species within the Nitrosomonadaceae (Betaproteobacteria) and nitrifying bacteria [i.e. Nitrospiraceae (Nitrospirae)]. Based on structural equation models, the effects of N additions on biocrust constituents were imposed through indirect effects on pH, soil electrical conductivity and ammonium concentrations. In summary, biocrust constituents are generally insensitive to chronic low levels of N depositions until rates reach above 1.5 g N m^-2  yr^-1 with diazotrophs being the most sensitive biocrust constituents followed by bacteria and finally fungi. Ultimately once the threshold is reached N deposition favours biocrust constituents utilizing inorganic N and other C sources over relying on phototrophic and/or N-fixing cyanobacteria for C and N.

[Therapeutic mechanism of emodin for treatment of rheumatoid arthritis: a network pharmacology-based analysis]

OBJECTIVE

To investigate the therapeutic mechanism of emodin in the treatment of rheumatoid arthritis (RA) using a network pharmacology-based method and validate this mechanism in a fibroblast-like synovial cell line.

METHODS

The PubChem, Targetnet, SwissTargetPrediction, Genecards, OMIM, and DisGeNET databases were searched to obtain emodin targets and RA-related genes. A protein-protein interaction (PPI) network was constructed, and GO and KEGG pathway enrichment analyses were carried out to analyze the intersection genes. AutoDock4.2.6 software was used to simulate molecular docking between emodin and its candidate targets. In a cultured fibroblast-like synovial cell line (MH7A), the effects of different concentrations of emodin on proliferation of tumor necrosis factor-α (TNF-α)-induced cells were investigated using CCK-8 assay, cell scratch experiment and flow cytometry; the changes in the expressions of nuclear factor-κB (NF-κB) pathway proteins were detected using Western blotting, and the mRNA expressions of the hub genes were examined with RT-qPCR.

RESULTS

We identified 32 intersection genes of emodin and RA, and the key targets including CAPS3, ESR1, and MAPK14 involved mainly the NF-κB signaling pathway. Cell scratch experiment and flow cytometry demonstrated a strong inhibitory effect of emodin on MH7A cell proliferation. Treatment with TNF-α significantly increased the cellular expressions of the NF-κB pathway proteins, which were obviously lowered by treatment with 80 μmol/L emodin. The results of RT-qPCR showed that TNF-α treatment obviously up-regulated the expressions of the hub genes COX2 and P38MAPK, and emodin treatment significantly down-regulated the expressions of MAPK and PTGS2 and up-regulated the expression of CASP3.

CONCLUSION

The therapeutic effect of emodin on RA is mediated mainly through regulation of cell proliferation, apoptosis, and the NF-κB pathway.

A bias away from Th2 in amniotic fluid is involved in preeclampsia

Inflammatory cytokines contribute to the pathophysiology of preeclampsia. However, whether the imbalance of Th1/Th2 cytokines in amniotic fluid is associated with preeclampsia is not well defined. In the present study, we collected peripheral blood and amniotic fluid from normal pregnancy (n = 25) and preeclampsia (n = 22) at last trimester during cesarean section. The Th1/Th2 cytokine levels in amniotic fluid supernatant were detected by a bead-based immunoassay. The percentage of IFN-γ⁺CD4⁺ T cells, TNF-α⁺CD4⁺ T cells, IL-4⁺CD4⁺ T cells and IL-10⁺CD4⁺ T cells in peripheral blood was detected by flow cytometry. We found that in normal pregnancy, the IFN-γ/IL-4 and IFN-γ/IL-5 ratios were decreased in amniotic fluid supernatant compared to that in plasma, indicating a Th2 bias. However, IFN-γ/IL-4 (P = 0.014), IFN-γ/IL-5 (P = 0.005) and IFN-γ/IL-13 (P = 0.047) ratios in amniotic fluid supernatant was significantly increased in preeclampsia patients. The percentage of IFN-γ⁺CD4⁺ T cells (20.70 ± 7.61% vs 16.55 ± 4.96%, P = 0.041) and TNF-α⁺CD4⁺ T cells (31.78 ± 10.66% vs 19.47 ± 13.54%, P = 0.048) was significantly elevated in preeclampsia compared to normal pregnancy. Our finding demonstrates that a shift away from Th2 bias in amniotic fluid and circulating CD4⁺ T cells is involved in the pathogenesis of preeclampsia. This study suggests restoring the Th2 bias in amniotic fluid might be a therapeutic target of preeclampsia.

The safty profile of blood salvage applied for collected blood with amniotic fluid during cesarean section

BACKGROUND

The guidelines of National Health Service(NHS, the United Kingdom) recommended for use in obstetrics at increased risk of bleeding, requiring two suction devices to reduce amniotic fluid contamination, however, when comes to massive hemorrhage, it is may difficult to operate because the complex operation may delay time. The aim of the study was to detect the effect of amniotic fluid recovery on intraoperative cell salvage in obstetrics and provide evidence for clinical applications.

METHOD

Thirty-four patients undergoing elective cesarean section were randomly divided into two groups. In group 1, the cumulative blood from the operation field, including the amniotic fluid, was collected using a single suction device for processing. In group 2, after suctioning away the amniotic fluid using another suction device for the cumulative blood from the operation field. From each group, four samples were taken, including maternal venous blood (sample I), blood before washing (sample II), blood after washing (sample III) and blood after filtration with a leukocyte filter (sample IV), to detect serum potassium (K +), hemoglobin (Hb), white blood cell (WBC), fetal hemoglobin (HbF), alpha fetoprotein (AFP) and squamous cell (SC) levels.

RESULTS

The AFP, K + and WBC levels of sample III and sample IV were significantly lower than sample I in group 1 and group 2 (P < 0.05). Significantly more SCs were found in sample III than in sample I in group 1 and group 2 (P < 0.05), but SCs of sample IV had no statistical difference compared to sample I in group 1 and group 2 (P > 0.05). There was no significant difference in the K + , Hb, WBC, AFP and SC levels of sample IV between group 1 and group 2 (P > 0.05). The HbF levels of sample III and sample IV were significantly higher in group 1 than in group 2 (P < 0.05).

CONCLUSION

There is little or no possibility for AF contamination to enter the re-infusion system when used in conjunction with a leucodepletion filter. For maternal with Rh-negative blood, we recommend two suction devices to reduce HbF pollution.

TRIAL REGISTRATION

ChiCTR1800015684 , 2018.4.15.

Freeze-thaw cycles change the physiological sensitivity of Syntrichia caninervis to snow cover

Spring, especially the freeze-thaw season, is considered the key period for the growth and carbon sequestration of desert mosses. It is not clear how the change in environment water and temperature affects the physiological characteristics of desert mosses in freeze-thaw season. In this study, the effects of water and freeze-thaw cycles on the physiological characteristics of Syntrichia caninervis were assessed by manipulating the increase or removal of 65% snow and changes in the freeze-thaw cycles. The results showed that the changes in snow depth, freeze-thaw cycles, and their interaction significantly affected the plant water content, osmoregulatory substances content, antioxidant substance, and antioxidant enzyme activities. The contents of free proline, soluble sugar, ascorbic acid (AsA), reduced glutathione (GSH), and malondialdehyde (MDA), and superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities increased significantly with the decrease in snow depth and freeze-thaw cycles. POD and free proline were the most sensitive to the snow depth and freeze-thaw cycles, while SOD and CAT were the least sensitive. Therefore, compared with the increase in freeze-thaw cycles, the reduction in freeze-thaw cycles weakened the physiological sensitivity of S. caninervis to snow depth changes.

[Effects of preoperative segmental mobility on the clinical and radiographic outcomes following one-level artificial cervical disc replacement]

Objective: To investigate the effects of preoperative segmental range of motion (ROM) on clinical and radiographical outcomes after artificial cervical disc replacement (ACDR) and explore whether ACDR could be indicated for patients with preoperative limited or excessive segmental ROM. Methods: From January 2008 to December 2017, patients who underwent Prestige-LP ACDR in West China Hospital were retrospectively reviewed. The preoperative and postoperative X-rays of the cervical spine were collected to measure the radiographic parameters, including cervical lordosis (CL), C(2-7) ROM, disc height (DH), disc angle (DA) and ROM at the arthroplasty level. Clinical outcomes were evaluated using the Japanese Orthopedic Association (JOA) and the Neck Disability Index (NDI) scores. The correlation between preoperative segmental ROM and postoperative clinical and radiographical outcomes were also analyzed. Results: A total of 161 patients were analyzed, with 73 males and 88 females. The mean age was (44±8) years, and the follow-up period was 34 months (12-120 months). JOA and NDI scores improved after ACDR (P<0.05). However, postoperative C(2-7) ROM and ROM at the arthroplasty level were comparable with preoperative counterparts (both P>0.05). Preoperative segmental ROM positively correlated with C(2-7) ROM and ROM at the arthroplasty segment (r=0.213、0.271, both P<0.05), but was negatively correlated with the change of ROM (r=-0.534, P<0.05). The segmental ROM was 4.0°±1.0° in the limited-ROM group (A) and 14.6°±1.3° in the excessive-ROM group (B), respectively. There were significantly more patients diagnosed with cervical spondylosis in group A than in group B (35.5% vs 10.7%, P<0.05). The level-distribution was statistically different between the two groups. C(5/6) and C(6/7) were prone to limited motion in group A, while C(4/5) and C(5/6) were predisposed to excessive motion in group B (all P<0.05). After surgery, C(2-7) ROM increased for 14.2°±16.8° in group A, while paradoxically decreased for 2.2°±14.4° in group B. However, C(2-7) ROM in group B was still larger than that in group A (P<0.05). Similarly, the ROM at the arthroplasty level increased by 3.1°±3.7° in group A, whereas the values decreased by 4.4°±4.2° in group B postoperatively. In addition, group A still had less segmental ROM than group B (P<0.05). The preoperative DH in group A was less than that in group B (P<0.05). The rates of ASD, HO, and high-grade HO in group A were all higher than those in group B but without significant differences (all P>0.05). Conclusion: Preoperative segmental ROM has no significant effects on clinical outcomes after ACDR; it has a positive correlation with postoperative global and segmental ROM while is negatively correlated with ROM change.

The prevalence and risk factors of high-altitude pulmonary hypertension among native Tibetans in Sichuan Province, China

Background

High-altitude pulmonary hypertension (HAPH) remains a concern due to its high mortality, however, studies evaluating its prevalence and risk factors are lacking.

Objective

To determine the prevalence of HAPH and its correlated factors among the highlanders living at 3200 metres above sea level in Ganzi Tibetan Automous Prefecture, Sichuan Province, China.

Methods

This was a single-center cross-sectional study involved 1129 subjects (mean age 46.6±14 years, 39% men). Native Tibetans with HAPH were defined as mean pulmonary artery pressure &gt;30mmHg achieved from transthoracic echocardiography.

Results

The crude prevalence of HAPH was 6.2%, and was more prevalent in men compared to women (8.6% vs 4.6%, P=0.005). The elder was more likely to develop HAPH (OR: 5.308, 95% CI: 2.562–10.993). Highlanders with HAPH had more severe metabolic abnormalities (including elevated blood pressure, blood glucose, blood lipids, BMI, etc. P value&lt;0.05) and significantly increased hemoglobin level (P=0.001). On multivariate logistic regression analysis, independent risk factors for HAPH were metabolic syndrome (OR: 3.128, 95% CI: 1.110–8.818), age (&gt;60 years vs &lt;40 years) (OR: 2.924, 95% CI: 1.282–6.669), and decreased SpO2 (OR: 1.072 per 1-unit decrease; 95% CI: 1.010–1.136).

Conclusion

It could be concluded that HAPH was prevalent among 6.2% native Tibetans in Sichuan Province, China. Increasing age, metabolic syndrome and decreased SpO2 were independent predisposing factors for HAPH

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): This study was funded by one Science and Technology Pillar Programs in Sichuan Province (Grant no. 2017SZ0008).

[Effect of high-titer plasma in pediatric patients with severe adenovirus pneumonia]

Objective: To explore the efficacy and safety of high-titer plasma in the treatment of pediatric patients with severe adenovirus pneumonia. Methods: The clinical data of 92 pediatric patients with severe adenovirus pneumonia admitted to pediatric intensive care unit (PICU) in Guangzhou Women and Children's Medical Center from January 2016 to October 2019 were retrospectively collected. According to the treatment with or without high-titer plasma, the patients were divided into plasma treatment group (n=41) and non-plasma treatment group (n=51). The 51 patients with chest radiograph showing more than half the lungs involved were divided into plasma treatment group (n=29) and non-plasma treatment group (n=22). According to fever duration before plasma treatment, patients were divided into early group (≤5 days, n=5), middle group (>5-10 days, n=14), and late group (>10 days, n=22). Baseline data, therapeutic effects, and prognosis of patients in each group were analyzed with t test, non-parametric rank sum test, one-way ANOVA and chi-square test. Results: Ninety-two patients were included. There were no significant differences in age, gender, body weight, fever duration, sequential organ failure assessment, and Murray lung injury score between plasma treatment group and non-plasma treatment group before admission (all P>0.05). The proportion of patients whose temperature drop to normal within 5 days was higher in plasma treatment group than that in non-plasma treatment group (88% (36/41) vs. 69% (35/51), χ(2)=4.745, P=0.029). However, there were no significant differences between the two groups in the proportions of invasive ventilator weaning within 14 days (63% (26/41) vs. 76% (39/51), χ(2)=1.868, P=0.172), transfer out from PICU within 14 days (49% (20/41) vs. 69% (35/51), χ(2)=3.724, P=0.054), discharge within 28 days (51% (21/41) vs. 61%(31/51), χ(2)=0.846, P=0.358) and survived patients (85% (35/41) vs. 76%(39/51), χ(2)=1.143, P=0.285). Among patients with severe chest radiograph, the proportions of patients whose temperature drop to normal within 5 days and survived patients were higher in plasma treatment group than those in non-plasma treatment group (86% (25/29) vs. 59% (13/22), χ(2)=4.843, P=0.028; 83% (24/29) vs. 55%(12/22), χ(2)=4.796, P=0.029, respectively). However, there were no significant differences between the two groups in the proportions of invasive ventilator weaning within 14 days (52% (15/29) vs. 59% (13/22), χ(2)=0.274, P=0.601), transfer out from PICU within 14 days (34% (10/29) vs. 45% (10/22), χ(2)=0.632, P=0.427), and discharge within 28 days (45% (13/29) vs. 45% (10/22), χ(2)=0.002, P=0.964). Among early, middle and late group, the proportions of invasive ventilator weaning within 14 days were 2/5, 13/14 and 50% (11/22), respectively, with statistically significant difference (χ(2)=8.119, P=0.017). There were no significant differences in the proportions of patients whose temperature drop to normal within 5 days (4/5, 14/14, 82% (18/22), χ(2)=2.965, P=0.227), transfer out from PICU within 14 days (2/5, 10/14, 36%(8/22), χ(2)=4.386, P=0.112), discharge within 28 days (2/5, 8/14, 50% (11/22), χ(2)=0.462, P=0.794) and survived patients (4/5, 13/14, 82% (18/22), χ(2)=0.966, P=0.617) in the three groups. Only one case with high-titer plasma therapy had rash in the course of infusing plasma and no other adverse reactions were observed. Conclusions: High-titer plasma can shorten the fever time and improve the proportion of survival patients in pediatric severe adenovirus pneumonia. The clinical effect of high-titer plasma is better in 5-10 days of fever course. High-titer plasma is an effective and safe treatment.

[Results analysis of occupational physical examination for major occupational hazards exposed laborer in 2018 in Guangzhou]

Objective: To analyze the results of occupational physical examination for major occupational hazard exposed laborer in 2018 in Guangzhou, to provide scientific basis for occupational health supervise. Methods: In January 2019, descriptive epidemiological methods were used as the data sources of the Occupational Disease and Occupational Health Information Surveillance System and the report data of Guangzhou Occupational Health Inspection Agency, collecting 2733 employers from 28 Occupational Health Inspection Organizations in 11 administrative regions of Guangzhou from January to December 2018, as well as the occupational health examination data of 97688 workers exposed to the occupational-disease-risk factors, to analyze the inspection of suspected occupational diseases and contraindications during the period of work of the workers who were monitored for the occupational hazard factors (silicon dust, welding fume, benzene, lead, Ethylene Dichloride, N-hexane, high temperature and hand-transmitted vibration) . Results: Total 128 cases of suspected occupational disease were detected, including 3 suspected silicosis, 8 suspected welder＇s pneumoconiosis, 17 suspected other pneumoconiosis, 10 suspected benzene poisoning, 1 suspected lead poisoning and 89 suspected noise deafness. There were 2061 cases of occupational contraindication, among which 550 cases were contraindication of high temperature, 261 cases were benzene and 1089 cases were noise. Conclusion: The Occupational Health Inspection Institution of this city should continuously monitor the occupational health status of the harmful workers during their work, do a good job of prevention, and strengthen the labor protection.

[Impact of artificial disc height on the morphology of cervical facet joint]

Objective: To investigate the impact of implant height on the morphology of cervical facet joints in artificial cervical disc replacement (ACDR). Methods: A finite element model of the cervical spine from C(2) to C(7) was constructed. The surgical processes of ACDR were simulated by insertion of 5 mm, 6 mm or 7 mm Prestige-LP artificial cervical discs. The morphological changes of cervical facet joints were recorded in terms of facet overlap distance, facet overlap area and facet angle. Results: The normal height Prestige-LP cervical disc could restore the natural status of the cervical spine. Compared with the intact condition, the model with ≥2 mm height implant would reduce the overall range of motion (ROM) by 19.2% in flexion, 19.4% in extension, 18.4% in lateral bending and 19.0% in axial rotation. Besides, the ROM at the surgical level reduced by 15.8% in flexion, 15.4% in extension and lateral bending and 19.0% in rotation. The upper and lower adjacent levels (C(4/5) and C(5/6)) showed more obvious changes in ROM, which reduced by 26.8% and 26.5% in flexion, 26.6% in extension, 26.5% and 26.4% in lateral bending, and 26.4% and 26.3% in rotation, respectively. The reduction of facet overlap distance, facet angle and facet overlap area with the ≥2 mm height artifact was 9.6%, 30.7%, and 17.9% respectively at the upper adjacent level, and 22.3%, 35.3% and 28.2% respectively at the surgical level, compared with the intact model.The morphology of facet joints at the lower adjacent level were slightly changed. Conclusion: The implant height selection in ACDR should be in accordance with the physiological intervertebral disc height. Artifact with ≥2 mm in height would obviously change the morphology of facet joints, thus should not be used in clinical practice.

Problems and challenges: development of blood transfusion services in Mainland China within the context of health-care system reform

OBJECTIVE

To evaluate the development of blood transfusion services in Mainland China within the context of health-care system reform.

BACKGROUND

China launched a health-care reform program in 2009 to redistribute health-care resources, which are currently over-concentrated in well-developed cities. A geographically equitable blood transfusion service is key to achieving this goal.

METHODS

Based on the national survey of blood establishments in July 2015, total blood collection, whole-blood donations per 1000 population and the supply and demand relationship were analysed at the administrative region level. Areas at different developmental levels were compared in terms of total blood collection and human resources.

RESULTS

In 2014, Mainland China's 31 provinces showed wide variation, with total blood collection in blood facilities ranging from about 1000 units to over 600 000 units (each 200 mL), and the whole-blood donation rate per 1000 population, ranging from 1·48 to 17·09. 69% of the country's total collection, was concentrated in 29 provincial capitals, and 31% was in 311 non-capital cities. Of 97 personnel with doctorates, 74 worked in 32 provincial blood establishments, whereas the remaining 23 worked at the other 318 blood stations. In most provinces, per permanent resident donation was within 2-4 mL, and blood volume per inpatient was 10-35 mL regardless of the development of the transfusion service.

CONCLUSION

In 2014, China had an imbalanced development and insufficient access to blood transfusion services. This service must be redeployed at the national level to facilitate health-care reform in China.

[Results analysis of occupational physical examination for silica dust, benzene and noise-exposed laborer in 2016 in Guangzhou City]

Objective: To analyze the results of occupational physical examination for silica dust, benzene and noise-exposed laborer in 2016 in Guangzhou, to provide basis for occupational health supervise. Methods: The data were derived from "occupational disease and health information surveillance system" and the summary data reported by all the occupational physical examination agencies, and analyzed by descriptive epidemiology method. Results: 77506 data from 21 agencies of 12 district were collected, and 63 suspected occupational disease were detected, which including 1 silicosis, 8 benzene poisoning, 54 noise deafness. Conclusion: Noise exposure was distributed widely, noise deafness had to be focused on, occupational chronic benzene poisoning and silicosis should be monitored continuously. Small, foreign economy and manufacturing industry should be supervised firstly.

Incidence of hepatitis B virus infection in young Chinese blood donors born after mandatory implementation of neonatal hepatitis B vaccination nationwide

This study was carried out to determine the incidence of hepatitis B virus (HBV) infection in the young generation born after mandatory implementation of hepatitis B vaccination since 1992. Repeat blood donors born between 1992 and 1997 were enrolled, who gave blood at least twice during the past 3 years. Donors were tested for HBV infection markers of HBsAg, anti-HBc, anti-HBs and viral DNA by immunoassays (EIAs) and nucleic acid tests (NAT). A total of 14 937 pre-donation screening qualified young repeat donors aged 18-23 years were tested with 9 (0.06%) being HBsAg by EIA and 10 (1:1494) HBV DNA positive by Ultrio NAT (10.4 IU/mL), respectively. HBV DNA was further detected in 1:192 (9/1732) anti-HBc+ repeat donors with Ultrio Plus NAT (3.4 IU/mL). Most cases were identified as occult HBV infection (OBI). Of 14 937 repeat donors, 20.9% were anti-HBc+ positive, while approximately 50% of 12 024 repeat donors were anti-HBs negative or had levels <100 IU/L. HBsAg+ or OBI strains were classified as wild type of genotype B or genotype C. Incident HBV infection in repeat donors was approximately 1:18.5 person-years (1.1%/year) but significantly less frequent in donors with confirmed HBV vaccination (2.4%-3.3%) than those unsure of vaccination status (10.5%; P = .0023). Hepatitis B virus vaccination appears largely protective of HBV infection, but incidence of infections increases in young adults with mostly undetectable or low anti-HBs or occasionally high anti-HBs. A boost of hepatitis B vaccine for adolescents prior to age 18 years may reduce HBV infection, and implementation of more sensitive NAT in blood donation screening may improve HBV safety in blood transfusion.

HBV/HCV co-infection is associated with a high level of HCV spontaneous clearance among drug users and blood donors in China

Understanding the biology of spontaneous clearance of hepatitis C virus (HCV) infection could lead to improved strategies to prevent the sequelae associated with chronic HCV infection. Chronic infections with hepatitis virus are very common in China, but the factors associated with spontaneous clearance of HCV have not been adequately studied. We evaluated the spontaneous clearance of HCV among 1918 drug users and 1526 HCV-seropositive blood donors in Guangzhou, China. Among participants who were co-infected with hepatitis B virus (HBV), 41.38% of drug users and 39.47% of blood donors had cleared their HCV infection without antiviral therapy compared to 9.41% of drug users and 16.73% of blood donors who were mono-infected with a single virus (P<.01). The proportion of subjects who had cleared their HCV infection was significantly greater in the co-infected subjects whose serum HBV DNA was greater than 2000IU/mL than those with lower levels. A multiple logistic regression analysis found female gender, IL28B rs8099917 TT genotype, HBV co-infection and blood donors (vs drug users) associated with increased spontaneous clearance of HCV infection. Although acute HCV infections are common in China, the incidence of chronic HCV may be reduced among the high prevalence of chronic HBV and IL28B genotypes associated with spontaneous clearance of HCV in Chinese populations.

Methylation-mediated loss of SFRP2 enhances invasiveness of non-small cell lung cancer cells

The malignancy of non-small cell lung cancer (NSCLC) largely results from its invasive manner. Secreted frizzled-related proteins (SFRPs) have been recently found to suppress the invasiveness of some cancers. On the other hand, the methylation of SFRPs increases protein degradation to reduce the activity of SFRPs, resulting in increased tumor cell invasion and cancer metastasis. However, the role of SFRPs in the invasion of NSCLC has not been reported. Here we analyzed the regulation of SFRPs in NSCLC cells and its effects on cell invasion. We found that SFRP2 mRNA was significantly decreased and methylation of SFRP2 gene was significantly increased in NSCLC tissue, compared to the paired adjacent nontumor tissue. Moreover, SFRP2 expression was significantly decreased in NSCLC cell lines. In NSCLC cell lines, the SFRP2 expression would be restored by the demethylation of SFRP2 gene with 5'-aza-deoxycytidine in NSCLC cell lines, at the levels of both mRNA and protein. Thus, the cell invasion would be suppressed. Furthermore, the demethylation of SFRP2 gene appeared to inhibit Zinc Finger E-Box Binding Homeobox 1 (ZEB1) and matrix metallopeptidase 9 (MMP9), two key factors that enhance NSCLC cell invasion. Thus, SFRP2 may inhibit NSCLC invasion by suppressing ZEB1 and MMP9, while its methylation promotes NSCLC invasion.

An integrated device with high performance multi-function generators and time-to-digital convertors

A highly integrated, high performance, and re-configurable device, which is designed for the Nitrogen-Vacancy (N-V) center based quantum applications, is reported. The digital compartment of the device is fully implemented in a Field-Programmable-Gate-Array (FPGA). The digital compartment is designed to manage the multi-function digital waveform generation and the time-to-digital convertors. The device provides two arbitrary-waveform-generator channels which operate at a 1 Gsps sampling rate with a maximum bandwidth of 500 MHz. There are twelve pulse channels integrated in the device with a 50 ps time resolution in both duration and delay. The pulse channels operate with the 3.3 V transistor-transistor logic. The FPGA-based time-to-digital convertor provides a 23-ps time measurement precision. A data accumulation module, which can record the input count rate and the distributions of the time measurement, is also available. A digital-to-analog convertor board is implemented as the analog compartment, which converts the digital waveforms to analog signals with 500 MHz lowpass filters. All the input and output channels of the device are equipped with 50 Ω SubMiniature version A termination. The hardware design is modularized thus it can be easily upgraded with compatible components. The device is suitable to be applied in the quantum technologies based on the N-V centers, as well as in other quantum solid state systems, such as quantum dots, phosphorus doped in silicon, and defect spins in silicon carbide.

Elevation of Vδ1 T cells in peripheral blood and livers of patients with primary biliary cholangitis

Primary biliary cholangitis (PBC), hitherto called primary biliary cirrhosis, is a cholestatic liver disease of unclear aetiology with autoimmune features. Accumulating evidence revealed that γδ T cells were involved in the development of autoimmune diseases. As one of γδ T cells subsets, however, the role of Vδ1 T cells in the immunopathogenesis of PBC is poorly understood. We analysed peripheral blood Vδ1 T cells in PBC patients in active stage (ASP, n = 18), adequate responders (AR, n = 10) and inadequate responders (IAR, n = 4) to ursodeoxycholic acid (UDCA) and an age-matched healthy control group (n = 16) by flow cytometric analysis. The ASP group exhibited a significantly higher proportion and absolute number of Vδ1 T cells, which were also observed in immunofluorescence staining of liver biopsy specimens of PBC patients. Moreover, these Vδ1 T cells expressed a series of activation markers and intracellular cytokines, which may contribute to the immunopathogenesis of PBC. Our study will help to clarify the role of Vδ1 T cells in the development of PBC.

Taxonomic evaluation of species in the Streptomyces hirsutus clade using multi-locus sequence analysis and proposals to reclassify several species in this clade

Previous phylogenetic analysis of species of the genus Streptomyces based on 16S rRNA gene sequences resulted in a statistically well-supported clade (100 % bootstrap value) containing eight species that exhibited very similar gross morphology in producing open looped (Retinaculum-Apertum) to spiral (Spira) chains of spiny- to hairysurfaced, dark green spores on their aerial mycelium. The type strains of the species in this clade, specifically Streptomyces bambergiensis, Streptomyces cyanoalbus, Streptomyces emeiensis, Streptomyces hirsutus, Streptomyces prasinopilosus and Streptomyces prasinus, were subjected to multi-locus sequence analysis (MLSA) utilizing partial sequences of the housekeeping genes atpD, gyrB, recA, rpoB and trpB to clarify their taxonomic status. The type strains of several recently described species with similar gross morphology, including Streptomyces chlorus, Streptomyces herbaceus, Streptomyces incanus, Streptomyces pratens and Streptomyces viridis, were also studied along with six unidentified green-spored Streptomyces strains from the ARS Culture Collection. The MLSAs suggest that three of the species under study (S. bambergiensis, S. cyanoalbus and S. emeiensis) represent synonyms of other previously described species (S. prasinus, S. hirsutus and S. prasinopilosus, respectively). These relationships were confirmed through determination of in silico DNA-DNA hybridization estimates based on draft genome sequences. The five recently described species appear to be phylogenetically distinct but the unidentified strains from the ARS Culture Collection could be identified as representatives of S. hirsutus, S. prasinopilosus or S. prasinus.

Prevalence of hepatitis A viral RNA and antibodies among Chinese blood donors

Like other developing countries, China was reported to have a relatively high seroprevalence of anti-hepatitis A antibodies (anti-HAV). However, no studies have evaluated the prevalence of anti-HAV and HAV RNA among voluntary blood donors with or without elevated serum alanine transaminase (ALT) levels. Anti-HAV antibodies were detected using an enzyme-linked immunosorbent assay, and reverse transcription quantitative polymerase chain reaction was carried out for detection of HAV RNA. In the current study, we analyzed a total of 450 serum samples with elevated ALT levels (≥40 U/L) and 278 serum samples with non-elevated ALT levels. Seroprevalence rates of anti-HAV were 51.6% in donors with elevated ALT and 41.4% in donors with non-elevated ALT; however, none of the samples was positive for HAV RNA. The results of our study showed lower seroprevalence rates of anti-HAV in blood donors (irrespective of ALT levels) than those in published data on Chinese populations. Although donors with elevated ALT had statistically higher prevalence rates of anti- HAV than did those with non-elevated ALT, none of the serum samples had detectable levels of the active virus. In conclusion, our results demonstrate that the transmission of hepatitis A by blood transfusion will occur rarely.

Mid-infrared Photoconductive Response in AlGaN/GaN Step Quantum Wells

AlGaN/GaN quantum structure is an excellent candidate for high speed infrared detectors based on intersubband transitions. However, fabrication of AlGaN/GaN quantum well infrared detectors suffers from polarization-induced internal electric field, which greatly limits the carrier vertical transport. In this article, a step quantum well is proposed to attempt solving this problem, in which a novel spacer barrier layer is used to balance the internal electric field. As a result, a nearly flat band potential profile is obtained in the step barrier layers of the AlGaN/GaN step quantum wells and a bound-to-quasi-continuum (B-to-QC) type intersubband prototype device with detectable photocurrent at atmosphere window (3-5 μm) is achieved in such nitride semiconductors.

Regulation of the Heme Oxygenase-1/carbon monoxide system by hydrogen sulfide in murine coxsackievirus B3-induced myocarditis

To explore the impact of hydrogen sulfide (H2S) on the heme oxygenase&mdash;1 (HO&mdash;1)/carbon monoxide (CO) system in coxsackie virus B3 (CVB3)&mdash;induced myocarditis. A total of 80 Balb/c mice were divided randomly into four groups designated N, C, P and S. Group N served as the negative control while groups C, P, and S were infected with CVB3 to induce myocarditis. Group P was additionally treated with DL&mdash;propargylglycine (PAG) to inhibit the generation of H2S while Group S was treated with NaHS, an H2S donor. Ten days after infection, heart sections were scored for histopathology. We also measured carboxyhemoglobin (COHb) levels in the blood and HO&mdash;1 expression by immunohistochemistry. 1. Each CVB3&mdash;infected group (C, P, and S) exhibited increased pathology, COHb levels, and HO&mdash;1 expression compared to uninfected controls. 2. Regarding histopathology, the score of group P was worse, while that of group S was better, than that of group C. 3. The P group COHb level was lower than group C, while the S group COHb level was higher than group C. 4. Positive HO&mdash;1 expression was seen in group C with reduced expression in group P and increased expression in group S. 5. A positive correlation was observed between the COHb concentration and HO&mdash;1expression; alternatively, a negative correlation was found between the histopathologic scores and both the concentration of COHb and the expression level of HO&mdash;1. Modulation of H2S can play a regulatory role in the pathogenesis of VMC by impacting the HO&mdash;1/CO pathway.

How do hosts react to endosymbionts? A new insight into the molecular mechanisms underlying the Wolbachia-host association

Wolbachia is an intracellular bacterium that has aroused intense interest because of its ability to alter the biology of its host in diverse ways. In the two-spotted spider mite, Tetranychus urticae, Wolbachia can induce complex cytoplasmic incompatibility (CI) phenotypes and fitness changes, although little is known about the mechanisms. In the present study, we selected a strain of T. urticae, in which Wolbachia infection was associated with strong CI and enhanced female fecundity, to investigate changes in the transcriptome of T. urticae in Wolbachia-infected vs. uninfected lines. The responses were found to be sex-specific, with the transcription of 251 genes being affected in females and 171 genes being affected in males. Some of the more profoundly affected genes in both sexes were lipocalin genes and genes involved in oxidation reduction, digestion and detoxification. Several of the differentially expressed genes have potential roles in reproduction. Interestingly, unlike certain Wolbachia transinfections in novel hosts, the Wolbachia-host association in the present study showed no clear evidence of host immune priming by Wolbachia, although a few potential immune genes were affected.

Incidence and factors associated with nosocomial infections in a neonatal intensive care unit (NICU) of an urban children's hospital in China

OBJECTIVE

The study's aim was to assess incidence and epidemiologic profile of nosocomial infection (NI) in a NICU of China, and to identify main risk factors of NIs.

MATERIALS AND METHODS

Chi square test for discrete variables and independent t-test for continuous variables to examine the association with NI. Univariate regression model was applied to the variables to predict the NI status. Finally the multivariate model was utilized with stepwise methods included all variables in the univariate model to extrapolate the independent variables to NI.

RESULTS

Infection rate in NICU during the study period was 6.2 episodes per 100 patients. Infection density was 4.2 episodes per 1,000 patient-days. Infection rate of ventilation-related pneumonia was 3.4 episodes per 1,000 mechanical ventilation (MV) days. Central line-associated bloodstream infection rate was 5.4 episodes per 1,000 central line days. Gestational age < 32 weeks, with congenital malformation, twins or triplets, gastric tube feeding, operation, duration of prophylaxis antibiotic use, duration of probiotic use, duration of parenteral nutrition were the risk factors associated with NI in NICU. We discussed the association between intrinsic factors of infants and health care procedures with NI.

CONCLUSION

This study provided information for prevention strategies of NI, that will ultimately improve the healthcare service level.

Classification of Streptomyces phylogroup pratensis (Doroghazi and Buckley, 2010) based on genetic and phenotypic evidence, and proposal of Streptomyces pratensis sp. nov

The Streptomyces phylogroup pratensis (Doroghazi and Buckley, 2010) contains isolates obtained from grassy fields, as well as Streptomyces flavogriseus ATCC 33331 and strain CGMCC 4.1868. This latter strain was received as Streptomyces griseoplanus but was subsequently found to be mislabeled, and S. flavogriseus ATCC 33331 (=IAF-45-CD) was shown to be clearly distinct from the type strain S. flavogriseus ATCC 25452(T) (=CGMCC 4.1884(T)). In order to evaluate the taxonomic position of phylogroup pratensis further, sequences of the 16S rRNA gene and five protein-coding housekeeping genes (atpD, gyrB, recA, rpoB and trpB) were determined for six strains of the phylogroup and type strains of 19 related species, which were selected by a BLAST search based on the sequences of the phylogroup. The 16S rRNA gene sequences for the phylogroup were identical to those of eight species belonging to cluster I of the S. griseus clade. However, in all the individual protein-coding gene and MLSA phylogenies, the phylogroup strains without exception formed an obviously distinct cluster that could be equated with a new species status. The phylogenetic evidence for the new species assignment was also supported by corresponding DNA-DNA hybridization values and by phenotypic characteristics. It is therefore proposed that the phylogroup should be classified as Streptomyces pratensis sp. nov., and the type strain is ch24(T) (=CGMCC 4.6829(T)=NRRL B-24916(T)).

Femtoliter-scale patterning by high-speed, highly scaled inverse gravure printing

Pattern printing techniques have advanced rapidly in the past decade, driven by their potential applications in printed electronics. Several printing techniques have realized printed features of 10 μm or smaller, but unfortunately, they suffer from disadvantages that prevent their deployment in real applications; in particular, process throughput is a significant concern. Direct gravure printing is promising in this regard. Gravure printing delivers high throughput and has a proven history of being manufacturing worthy. Unfortunately, it suffers from scalability challenges because of limitations in roll manufacturing and limited understanding of the relevant printing mechanisms. Gravure printing involves interactions between the ink, the patterned cylinder master, the doctor blade that wipes excess ink, and the substrate to which the pattern is transferred. As gravure-printed features are scaled, the associated complexities are increased, and a detailed study of the various processes involved is lacking. In this work, we report on various gravure-related fluidic mechanisms using a novel highly scaled inverse direct gravure printer. The printer allows the overall pattern formation process to be studied in detail by separating the entire printing process into three sequential steps: filling, wiping, and transferring. We found that pattern formation by highly scaled gravure printing is governed by the wettability of the ink to the printing plate, doctor blade, and substrate. These individual functions are linked by the apparent capillary number (Ca); the printed volume fraction (φ(p)) of a feature can be constructed by incorporating these basis functions. By relating Ca and φ(p), an optimized operating point can be specified, and the associated limiting phenomena can be identified. We used this relationship to find the optimized ink viscosity and printing speed to achieve printed polymer lines and line spacings as small as 2 μm at printing speeds as high as ∼1 m/s.

Streptomyces atacamensis sp. nov., isolated from an extreme hyper-arid soil of the Atacama Desert, Chile

The taxonomic position of a Streptomyces strain isolated from an extreme hyper-arid soil sample collected from the Atacama Desert was determined using a polyphasic approach. The strain, isolate C60T, had chemical and morphological features typical of members of the genus Streptomyces and formed a distinct phyletic line in the Streptomyces 16S rRNA gene tree, together with the type strain of Streptomyces radiopugnans . The two strains were distinguished readily using a combination of phenotypic properties and by a DNA–DNA relatedness value of 23.17 (±0.95) %. On the basis of these genotypic and phenotypic data, it is proposed that isolate C60T ( = CGMCC 4.7018T = KACC 15492T) be classified in the genus Streptomyces as Streptomyces atacamensis sp. nov.

Streptomyces chlorus sp. nov. and Streptomyces viridis sp. nov., isolated from soil

Two actinomycete strains, BK125(T) and BK199(T), isolated from a hay meadow soil sample were investigated to determine their taxonomic position using a polyphasic approach. The isolates produced greenish-yellow and light green aerial mycelium on oatmeal agar, respectively. They contained anteiso-C15 : 0, iso-C15 : 0 and C16 : 0 as the major fatty acids, and MK-9 (H6) and MK-9 (H8) as the predominant isoprenoid quinones. Phylogenetic analysis of the 16S rRNA gene sequences showed that the isolates formed distinct phyletic lines towards the periphery of the Streptomyces prasinus subclade. Analysis of DNA-DNA relatedness between the two isolates showed that they belonged to different genomic species. The organisms were also distinguished from one another and from type strains of species classified in the S. prasinus subclade using a combination of genotypic and phenotypic properties. On the basis of these data, it is proposed that the isolates be assigned to the genus Streptomyces as Streptomyces chlorus sp. nov. and Streptomyces viridis sp. nov. with isolates BK125(T) ( = KACC 20902(T) = CGMCC 4.5798(T)) and BK199(T) ( = KACC 21003(T) = CGMCC 4.6824(T)) as the respective type strains.

Taxonomic evaluation of the Streptomyces hygroscopicus clade using multilocus sequence analysis and DNA-DNA hybridization, validating the MLSA scheme for systematics of the whole genus

Streptomyces hygroscopicus and related species are the most well known candidate producers of antibiotics and many other industrially and agronomically important secondary metabolites in the genus Streptomyces. Multilocus sequence analysis (MLSA) has shown to be a powerful and pragmatic molecular method for unraveling streptomycete diversities. In this investigation, a multilocus phylogeny of 58 representatives of the S. hygroscopicus 16S rRNA gene clade including S. violaceusniger and related species was examined. The result demonstrated that the MLSA data were helpful in defining members of the S. hygroscopicus clade, providing further evidence that the MLSA scheme of five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) is a valuable alternative for creating and maintaining operational protocols for the Streptomyces species assignment. DNA-DNA hybridization (DDH) between strains with representative MLSA evolutionary distances, combined with previous data from S. griseus and S. albidoflavus clades, revealed a high correlation between MLSA and DDH, and sustains that the five-gene nucleotide sequence distance of 0.007 could be considered as the species cut-off for the whole genus. This significant correlation thus makes the MLSA scheme applicable to construction of a theory-based taxonomy for both ecology and bioprospecting of streptomycetes. Based on the MLSA and DDH data, as well as phenotypic characteristics, 10 species and three subspecies of the S. hygroscopicus clade are considered to be later heterotypic synonyms of eight genomic species, and Streptomyces glebosus sp. nov., comb. nov. (type strain CGMCC 4.1873(T)=LMG 19950(T)=DSM 40823(T)) and Streptomyces ossamyceticus sp. nov., comb. nov. (type strain CGMCC 4.1866(T)=LMG 19951(T)=DSM 40824(T)) are also proposed.

Azilsartan treatment improves insulin sensitivity in obese spontaneously hypertensive Koletsky rats

AIM

Hypertension often coexists with insulin resistance. However, most metabolic effects of the antihypertensive agents have been investigated in nomotensive animals, in which different conclusions may arise. We investigated the metabolic effects of the new angiotensin II type 1 receptor blocker azilsartan using the obese Koletsky rats superimposed on the background of the spontaneously hypertensive rats.

METHODS

Male Koletsky rats were treated with azilsartan (2 mg/kg/day) over 3 weeks. Blood pressure was measured by tail-cuff. Blood biochemical and hormonal parameters were determined by enzymatic or ELISA methods. Gene expression was assessed by RT-PCR.

RESULTS

In Koletsky rats, azilsartan treatment lowered blood pressure, basal plasma insulin concentration and the homeostasis model assessment of insulin resistance index, and inhibited over-increase of plasma glucose and insulin concentrations during oral glucose tolerance test. These effects were accompanied by decreases in both food intake and body weight (BW) increase. Although two treatments showed the same effect on BW gain, insulin sensitivity was higher after azilsartan treatment than pair-feeding. Azilsartan neither affected plasma concentrations of triglyceride and free fatty acids, nor increased adipose mRNA levels of peroxisome proliferator-activated receptor (PPAR)γ and its target genes such as adiponectin, aP2. In addition, azilsartan downregulated 11β-hydroxysteroid dehydrogenase type 1 expression.

CONCLUSIONS

These results show the insulin-sensitizing effect of azilsartan in obese Koletsky rats. This effect is independent of decreases in food intake and BW increase or of the activation of adipose PPARγ. Our findings indicate the possible usefulness of azilsartan in the treatment of metabolic syndrome.

Streptomyces herbaceus sp. nov., Streptomyces incanus sp. nov. and Streptomyces pratens sp. nov., isolated from the soil of a hay meadow

The taxonomic positions of three streptomycetes isolated from a soil sample from a hay meadow were determined using a polyphasic approach. The isolates had chemical and morphological properties typical of the genus Streptomyces and, in phylogenetic analyses based on 16S rRNA gene sequences, formed a distinct subclade that was most closely related to the Streptomyces prasinus subclade. DNA-DNA relatedness studies showed that the novel strains belonged to three different genomic species. The novel strains could be distinguished from one another and from the type strains of the species classified in the S. prasinus subclade using a combination of genotypic and phenotypic properties. On the basis of these data, it is proposed that the novel strains be assigned to the genus Streptomyces as Streptomyces herbaceus sp. nov., Streptomyces incanus sp. nov. and Streptomyces pratens sp. nov., with BK119(T) ( = KACC 21001(T)  = CGMCC 4.5797(T)), BK128(T) ( = KACC 21002(T)  = CGMCC 4.5799(T)) and BK138(T) ( = KACC 20904(T)  = CGMCC 4.5800(T)) as the respective type strains.

Fluorescence in situ hybridization on plant extended chromatin DNA fibers for single-copy and repetitive DNA sequences

The compactness of plant chromosomes and the structure of the plant cell wall and cytoplasm provide a great obstacle to fluorescence in situ hybridization (FISH) for single-copy or low-copy DNA sequences. Consequently, many new methods for improving spatial resolution via chromosomal stretching have been employed to overcome this technical challenge. In this article, a technique for extracting cell-wall free nuclei at mitotic interphase, then using these nuclei to prepare extended DNA fibers (EDFs) by the method of a receding interface, whereby slide-mounted chromatin produces EDFs in concert with gravity-assisted buffer flow, was adopted as a result of the low frequency of EDF damage produced by this procedure. To examine the quality of these EDFs, we used single-copy gene encoding S-locus receptor kinase and multi-copy 5S rDNA (ribosomal DNA) as probes. The resulting EDFs proved suitable for high-resolution FISH mapping for repetitive DNA sequences, and the localization of a single-copy locus.