Seasonal resource selection of free-ranging Zhongwei goats in the semi-arid grassland.

Goats rarely move and forage randomly. They tend to move in ways generally influenced by biotic and abiotic factors, respectively. However, few studies have explored the foraging behaviour of goats in the absence of predation and human disturbance. Based on step selection function modelling framework, Normalised Difference Vegetation Index, vegetation surveys, and Global Positioning System tracking of 124 free-ranging domestic adult male Zhongwei goats over one year (2016-2017) were used to assess how biotic and abiotic environmental factors affected their spatiotemporal distribution, and developed a conceptual model to represent the goats' trade-off between forage quantity and preference at different seasons, in the semi-arid grassland of Loess Plateau of 1 178 hectare. The results showed that spatial distributions of goats responded to spatiotemporal variation of biotic factors rather than abiotic factors of elevation, slope and solar radiation, which indicated that biotic factors were of priority to abiotic factors in the foraging process for the goats. According to the season changing, the goats positively used areas with higher forage quantity in the spring and winter, areas of higher forage quantity and preferred species in summer, and areas of abundance of preferred species in autumn. We developed a model to describe the phenomenon that the goats selected areas with higher preferred species only when the forage quantity was plentiful, otherwise they selected areas with higher forage quantity. Better understanding of the patterns and drivers of spatiotemporal distribution of the goats can improve our ability to predict foraging behaviour of livestock in heterogeneous environment and lead to better management practices and policies for the sustainability of these semi-arid landscapes and associated ecosystem services.

The Accelerated Progression of Atherosclerosis Correlates with Decreased miR-33a and miR-21 and Increased miR-122 and miR-3064-5p in Circulation and the Liver of ApoE-/- Mice with Streptozocin (STZ)-Induced Type 2 Diabetes.

Atherosclerosis is a major risk factor for type 2 diabetes (T2D) mortality. We aim to investigate the changes in miR-21, miR-122, miR-33a and miR-3064-5p in circulation and the liver of ApoE-/- mice with streptozocin (STZ)-induced T2D. Twenty 5-week-old male ApoE-/- mice were randomly assigned to the control (n = 10) and T2D group (n = 10) and intraperitoneally injected with a citrate buffer and streptozotocin (STZ) (40 mg/kg BW) once a day for three consecutive days. The successfully STZ-induced T2D mice (n = 5) and control mice (n = 5) were then fed with a high-fat diet (HFD) for 34 weeks. Compared to the control mice, ApoE-/- mice with STZ-induced T2D had slower (p < 0.05) growth, increased (p < 0.05) total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C), decreased (p < 0.05) high-density lipoprotein cholesterol (HDL-C) in serum, reduced (p < 0.05) TC and sterol regulatory element-binding protein-2 (Srebp-2), elevated (p < 0.05) ATP-binding-cassette-transporter-A1 (Abca1) in the liver, aggravated (p < 0.05) atherosclerotic lesions in the aorta, downregulated (p < 0.05) miR-21 and miR-33a, and upregulated (p < 0.05) miR-122 and miR-3064-5p in serum and the liver. In addition, the aortic lesions showed a positive correlation with miR-122 (r = 1.000, p = 0.001) and a negative correlation with miR-21 (r = −1.000, p = 0.001) in ApoE-/- mice with T2D. In conclusion, T2D-accelerated atherosclerosis correlates with a reduction in miR-21 and miR-33a and an elevation in miR-122 and miR-3064-5p in circulation and the liver of ApoE-/- mice.

Prevalence and Factors Associated With Suicidal Ideation in Medical Students With Migraine.

Background: The association between migraine and suicide ideation has been identified. However, the predictive factors of suicidal ideation are still controversial and whether migraine with aura can serve as an independent associated factor is uncertain. This manuscript studied the association between migraine with aura and suicidal ideation and explored the predictive factors for suicidal ideation. Methods: We surveyed 9,057 medical students and included 579 medical students with migraine into our study population. All students completed the General Situation Questionnaire, the Verified Headache Questionnaire, Hamilton Anxiety Scale (24 items), Hamilton Depression Scale (24 items), 36-item Health Survey Brief (SF-36), Headache Impact Text-6 (HIT-6), Test Anxiety Scale (TAS), and Pittsburgh Sleep Quality Index (PSQI). Suicidal ideation was measured by the Self-rating Idea of Suicide Scale (SIOSS). Results: Out of the 579 migraine medical college students, 562 (age 19.6 ± 1.6; 448 women and 114 men) were included in the final study. The positive rate of suicidal ideation was 13.7%. Compared with students suffering from migraine without aura, those having migraine with aura had higher suicidal ideation (p < 0.015). After adjusting for demographic factors and headache characteristics, migraine with aura was found to be independently associated with suicidal ideation. Other independent associated factors include anxiety, depression, test anxiety, sleep, headache, and quality of life. Among these various factors, high quality of life was found to play a protective role against suicidal ideation. Conclusions: Migraine with aura is independently associated with suicidal ideation. Furthermore, anxiety, depression, text anxiety, poor sleep quality, and headache frequency are associated with suicidal ideation among medical college students with migraine.

Novel combined method of biosorption and chemical precipitation for recovery of Pb2+ from wastewater.

A novel combined biosorption-precipitation process has been designed and applied to recycle Pb2+ from low concentration lead containing wastewater. Pb2+ was firstly removed selectively from wastewater by pyromellitic dianhydride (PMDA) modified sugarcane bagasse (SB) fixed-bed column, and then, it was desorbed into the concentrated eluate and recycled by adding chemical precipitant. Adsorption performance of the column and optimum desorption and precipitation condition for Pb2+ were investigated in detail. Results showed that the as-prepared column could efficiently remove Pb2+ from aqueous solution and optimum condition for Pb2+ precipitation in eluate was at pH 3.0 and molar ratio of precipitant to Pb2+ of 5:1 by using Na3PO4 as precipitant. Recovery experiment illustrated that Pb2+ was selectively removed from wastewater containing ions of Pb2+, Zn2+, Cd2+, Ca2+, K+, and Na+ through competitive substitution adsorption on the modified SB, and mass ratio of the five metal ions in eluate was 96.8:0.7:0.7:0.7:0.5:0.5. Pb2+ in this concentrated and purified eluate solution was recycled efficiently by adding Na3PO4. The combined method had great potential in application of heavy metal recovery from wastewater.

Facile synthesis of α-alkoxyl amides via scandium-catalyzed oxidative reaction between ynamides and alcohols.

A novel and efficient scandium-catalyzed oxidative reaction between ynamides and alcohols for the facile synthesis of various α-alkoxyl amides is reported in this paper. The reaction avoids the need for the use of α-diazo carbonyls which are unstable and may cause some safety concerns. Instead, by using alkynes as the starting materials, this protocol features readily available substrates, compatibility with a broad range of functional groups, simple procedure, mild reaction conditions, and high chemoselectivity.

Selective adsorption and recycle of Cu2+ from aqueous solution by modified sugarcane bagasse under dynamic condition.

Tetraethylenepentamine modified sugarcane bagasse was prepared and applied to test its feasibility in removing and recovering Cu2+ from wastewater under dynamic condition. Results showed that the Cu2+ could be selectively absorbed from wastewater by the modified SCB fixed bed column. To understand the adsorption mechanism, Cd2+ had been selected as the model interfering ion to investigate how co-ions influence the adsorption of Cu2+ on the sorbent. It was observed that the adsorption capacity of the sorbent for Cu2+ (0.26 mmol g-1) was significantly higher than that of Cd2+ (0.03 mmol g-1), even when the Cd2+ initial concentration was 100 times higher than that of Cu2+ in the binary system. This finding indicated that the presence of Cd2+ in the solution exerted negligible influence on the adsorption of Cu2+ on the modified SCB. The selectivity of the modified sorbent was further confirmed in the Cu/Cd/Mg/Pb/K quinary system. Further analysis to dynamic adsorption experiment illustrated that, due to the presence of amine groups, the modified SCB showed strong coordination ability to Cu2+, which allowed the other adsorbed ions (e.g., Cd2+) desorbed. This high adsorption selectivity toward Cu2+ suggested that this prepared sorbent would be a promising candidate for removing and recovering Cu2+ from wastewater.

[Construction of RevS gene knock-out mutant of Streptococcus suis serotype 2].

OBJECTIVE: To construct a gene knock-out mutant of response regulator named RevS in Streptococcus suis serotype 2 virulent strain 05ZYH33, and to investigate the effects of its deletion on the biological characters of this pathogen and the pathogenesis to mice and piglets. METHODS: Recombinant gene knock-out vector consisting of Spc(r) cassette was constructed and flanking was constructed consisting of Spc(r) cassette with flanking homology regions to the RevS genes while the isogenic RevS-deficient mutant was screened by allelic replacement. The effects of RevS deletion on the basic biological characters of 05ZYH33 including growth stability, colonial morphology, haemolysis, Gram staining, growth curve and protein expression were examined in vitro. The mice and piglets were infected with 10(8) CFU wild virulent and mutant isolates. RESULTS: PCR analysis confirmed that the coding genes of RevS were replaced completely by Spc(r) cassette and the basic biological characters of 05ZYH33 did not undergo any apparent change. Balb/c mice infection assay indicated that RevS play a role in the pathogenesis of Streptococcus suis infections, while no remarkable difference was observed in the piglets' pathogenesis infection rates between mutant isolates deltaA05ZYH33 and wild-type isolates 05ZYH33. CONCLUSION: The mutant of Streptococcus suis 05ZYH33 response regulator was successfully constructed, while the mutation did not obviously affect the bacterial biological characters, while the knock-out mutant of RevS was shown to be attenuated in pathogenesis to mice and piglets.

[Study on molecular epidemiology of major pathogenic Streptococcus suis serotypes in middle part of Jiangsu province].

OBJECTIVE: To determine the prevalence of Streptococcus suis and major pathogenic serotypes in middle part of Jiangsu province. METHODS: Tonsillar specimens from 303 slaughtered pigs aged 6 to 8 months were investigated for the presence of Streptococcus suis and major pathogenic serotypes by polymerase chain reaction (PCR) method. Bacteriological examination compared with molecular genetics identification for three Streptococcus suis isolates were also done. RESULTS: The overall carrier rate of Streptococcus suis was up to 88.0%, with the percentages of serotype 1(14), 2(1/2), 7 and 9 were 9.6%, 8.5%, 11.3% and 29.5% respectively in 2005. While in 2006, the prevalence of Streptococcus suis was 82.5%, with capsular types 1 (14), 2 (1/2), 7 and 9 were accounted for 17.6%, 2.4%, 25.8% and 20.0% of all the specimens. All the three isolates belonged to Streptococcus suis serotype 2,named 2a, 2f and 14e, which exhibiting the virulent phenotype cps2+/gdh+/mrp-/lepf-/sly-/fbps+/orf2+/89k-, cps2+/lgdh+/mrp-/epf-/sly-/fbps-/orf2-/89k- and cps2+/gdh+/mrp-/epf-/sly-/fbps/orf2-/ respectively. These isolates were all susceptible to amoxicillin, ampicillin, penicillin and resistant to amikacin and tetraycline. Clinical signs were not noted in BALB/c mice and rabbit. CONCLUSION: Prevalence of the Streptococcus suis among the healthy herds in the areas was very high, with various capsule types of Streptococcus suis involved in the same herds, and the virulent phenotype of these 3 isolates were very different from those prevalent Streptococcus suis serotype 2 virulent isolates frequently discovered from the epidemic areas.

[Homologous analysis of Streptococcus suis srt gene and prokaryotic expression of srtA].

AIM: To elucidate the distribution of srt gene in the genome of S.suis 05ZYH33, prokaryotically express Sortase A and analyze its antigenicity. METHODS: Homologous genes encoding sortase family members were analyzed, and then the srtA gene of S.suis was cloned and sequenced. The recombinant protein was analyzed by SDS-PAGE and Western blot. The mice were immunized with recombinant protein and the antibody titer was determined by indirect ELISA. RESULTS: All the putative srt genes in the genome of 05ZYH33 were analyzed. Six genes were found to be homologous to srt of S.suis isolated in Japan. The predicted srtA and sortase-like proteins were members of Class A of sortase family while srtBCD and srtE belonged to Class B. Western blot analysis showed that the recombinant protein was reactive to with the serum from the rabbits infected with a virulent strain of S.suis Type 2. The antibody titer in blood serum reached 1:6 400 after immunization with recombinant protein four times. CONCLUSION: Compared with the isolated strain from Japan a new putative srt gene was found in 05ZYH33. The srtA gene was successfully expressed in prokaryotic system and the recombinant protein showed specific antigenicity, which is important for future research of the function of Sortase.

Early-phase endotoxic shock-induced myocardial injury increases iNOS and selectin expression in macaque primate.

BACKGROUND: Our previous study has established a macaque model with early-phase endotoxic shock. The present study further investigated myocardial and blood vessel injury in Macaques by examining the subsequent expression of ACP, selectins, iNOS, and cTnI in response to LPS treatment. METHODS: In an experiment with anaesthetised, instrumental macaques, eleven animals were randomised into: an En group (n=6), receiving a dose of 2.8 mg kg(-1) lipopolysaccharides (LPS) by i.v.; and a Co group (n=5), injected with normal saline of 1 ml kg(-1). Cytochemistry of acid phosphatase (ACPase) in heart was performed by electron microscope at 120 min following endotoxin injection. Three immunochemical stains, namely, L-selectin, P-selectin and iNOS protein in heart, were studied. In addition, cardiac troponin I (cTnI), L-selectin and P-selectin in plasma were detected. RESULTS: In the early phase of endotoxic shock, LPS caused myocardial lysosome damage. The data of immunochemical staining showed the thrombus formation in vessels and the increase of iNOS, L-Selectin and P-Selectin expression in heart, but LPS challenge did not change L-selectin, P-selectin and cTnI in plasma. CONCLUSION: The increase of iNOS, L-selectin and P-selectin protein expression following endotoxin administration may have caused vessel injury and myocardial damage in macaques.

[Study on expression of Streptococcus suis serotype 2 sly gene, purification and activity of its product].

OBJECTIVE: To clone and express Streptococcus suis serotype 2 (S. suis 2) sly gene for constructing an foundation on identification of S. suis 2 protective antigen. METHODS: The sly gene was amplified from S. suis 2 clinical isolate strain 05ZYH33 genome DNA by PCR. The gene fragment was inserted into the expression vector pET-30b(+) to build pET30b-sly. When recombinant vector pET30b-sly was identified by restriction enzyme cutting and DNA sequencing as a correct one, subsequently it was transformed to E. coli Rosetta for expression under IPTG induction. The obtained fusion protein was purified by Ni-NTA affinity chromatography. The immunologic and hemolysis activity of the purified protein was proved through Western blot and hemolysis assay respectively. RESULTS: The PCR product was around 1500 bp. The gene segment inserted into the recombinant vector was proven to be completely identical with the sly gene sequence in the total genome sequence of S. suis 2. The target protein expressed was up to 30% of the total somatic protein under IPTG induction. The protein purity reached above 80% after purification. The protein could be recognized by human serum infected with S. suis 2 and could dissolve swine erythrocytes with the Hemolytic titer as 256. CONCLUSION: The expression vector pET30b-sly was successfully constructed. The target protein could be over-expressed in E. coli and possessed its biological activity after purification.

Effect of fluid resuscitation on ryanodine receptor in macaques with endotoxic shock.

OBJECTIVE: Our recent study demonstrated that sodium bicarbonate improved cardiac function in macaque models with early-phase endotoxic shock. In the present study, we investigated further the ryanodine receptor/calcium release-channel (RyR) and calcium pump after fluid resuscitation of macaques with early-phase endotoxic shock. METHODS: Twenty-four anaesthetised macaques were assigned to four groups. Nineteen animals were given an intravenous dose of 2.8 mgkg(-1) lipopolysaccharide (LPS). Sixty minutes after the LPS challenge, the animals were given (i) 5 mLkg(-1) normal saline (Ns group, n = 6), (ii) 5 mLkg(-1) of 5% sodium bicarbonate (Sb group, n = 6) or (iii) 5 mLkg(-1) of 3.5% hypertonic sodium chloride (Hs group, n = 7). The control group (Co group, n = 5) received 1 mLkg(-1) normal saline and then with 5 mLkg(-1) normal saline 60 min later. RESULTS: Endotoxin produced a reduction of the density of RyR but did not alter the affinity of RyR. Compared with normal saline, sodium bicarbonate or hypertonic saline induced a restoration of density of RyR but did not influence the affinity of RyR and the calcium pump. CONCLUSION: Up-regulation of RyR performance in myocardium following administration of sodium bicarbonate contributes to the improvement of cardiac function in macaques in the early phase of endotoxic shock.

[Cloning and prokaryotic expression of truncated muramidase-released protein gene of human Streptococcus suis type 2].

AIM: To clone and express the truncated Habb mrp gene of human Streptococcus suis type 2 (S.suis 2) and detect its activity. METHODS: A pair of primers based on S.suis 2 mrp gene were schemed out. The turncated mrp (tmrp)gene of S.suis 2 strain Habb isolated from diseased person in Haian, Jiangsu province was cloned and analyzed. The prokaryotic expression plasmid pGEX4T-2-tmrp was constructed.The expression of recombinant protein with glutathione S-transferase (GST) was induced in E.coli TG1. The fusion protein (tMRP-GST) was purified by affinity chromatography, and the GST was cut from tMRP-GST with thrombin protease to gain the truncated MRP (tMRP) antigen. The activity of recombinant protein was analyzed by Western blot. RESULTS: Sequence analysis showed that the length of the truncated mrp was 957 bp. The prokaryotic expressed production was a fusion protein, whose molecular weight was about 61 kD, and the molecular weight of the purified tMRP protein was about 35 kD. Western blot analysis showed that tMRP-GST and tMRP were detected specifically by MRP antiserum on nitrocellulose membrane. CONCLUSION: The truncated mrp gene of human S.suis 2 strain Habb is successfully cloned, and the high expression of the functional recombinant protein is achieved in the prokaryotic system, which facilitates the further studies on the bio-function and immunology.

Endotoxic shock model with fluid resuscitation in Macaca mulatta.

These studies established a macaque model of early-phase endotoxic shock, and investigated the resuscitation effects of three different solutions. Twenty-four macaques were assigned to four groups. Nineteen animals were given an intravenous dose of 2.8 mg/kg lipopolysaccharide (LPS). At 60 min after LPS challenge, the animals were given (i) 5 mL/kg normal saline (Ns group, n=6), (ii) 5% of 5 mL/kg sodium bicarbonate (Sb group, n=6), (iii) hypertonic 3.5% sodium chloride of 5 mL/kg (Hs group, n=7). The control group (Co group, n=5) was first injected with 1 mL/kg Ns and with 5 mL/kg Ns 60 min later. Haemodynamic parameters and blood gases were measured during the experiment, and myocardial morphology was examined on termination of the experiment. Administration of LPS caused hypotension and decreases of the left ventricular work index (LVWI). In the Sb group, mean arterial pressure, cardiac index, systemic vascular resistance index, LVWI and right ventricular work index were significantly higher than those of the Ns group. Pathological changes of myocardium were identified in all of the LPS groups. The studies suggest that macaques are suitable models for studying endotoxic shock and potential fluid therapies.

[Detection of virulence-associated factors of Streptococcus suis by multiplex PCR assay].

OBJECTIVE: To rapidly and sensitively detect the four virulence-associated factors of Streptococcus suis, a multiplex PCR was developed. METHODS: In the process of this reaction, four distinct DNA targets were amplified. One target was based on the serotype 2 (and 1/2) specific cps gene and the others were based on Streptococcus suis mrp, epf (epf*) and sly gene, encoding the MRP, EF(EF*) and Sly proteins of Streptococcus suis. 72 isolates, which including 48 strains of Streptococcus suis and 24 strains of negative control, and 49 clinical specimens were detected by the multiplex PCR assay. RESULTS: All PCR products were detected by electrophoresis on 1.2% agarose gels. With the 48 Streptococcus suis strains, the positive detection rates of cps2+, mrp+, epf+, epf*+ and sly+ were 16/48, 14/48, 12/48, 3/48 and 26/48,respectively. The results were confirmed by bacteriological examination. There were no specific amplification products including 49 clinical specimens and 24 negative control strains. CONCLUSION: The results demonstrated that multiplex PCR was a highly specific and sensitive diagnostic tool for the detection of virulence-associated factors of streptococcus suis.

[Screening and identification of mimic epitopes of monoclonal antibodies against hantaan virus using phage display technique].

AIM: To obtain mimic epitopes of monoclonal antibody (mAb) against Hantaan virus, and identify preliminarily their immunological characteristics. METHODS: Group-specific mAbs F3 and B11 were used as selective molecules for biopanning. After biopanning, the positive phages were identified by ELISA and DNA sequencing. Among the positive phages, F3-8, B11-18, B11-20 and B11-24 were selected to immunize BALB/c mice three times, respectively. The antiserum was then titered and confirmed by sandwich ELISA and competition ELISA. RESULTS: After 3 to 4 rounds of effective screening, the majority of the selected clones were found able to react to mAb F3 or B11 in a dose-dependent manner, but not to BSA, rHBsAg or other unrelated mAbs. The amino acid sequences of the clones binding to mAb F3 contained an identical sequence MHGPTKNQMWHT, which had higher homology to 750-759 amino acids between a pair of cysteines within glycoprotein G2 of HTNV/SEOV, while those of clones binding to mAb B11 had no evident homologous regions within HTNV/SEOV proteins. The specific antibodies increased significantly following immunization with phage peptides, which indicated that the phage-displayed peptides had not only good antigenicity, but also strong immunoreactivity. CONCLUSION: The phage-displayed peptides could mimic the epitope of HFRSV antigen, which would provide the potential for preparing more effective epitope-based vaccines and specific diagnostic reagents.

[Antimicrobial susceptibility in vitro of 32 drugs against pig Streptococcus isolates in China].

A number of 65 Streptococcus species isolated from diseased pigs were surveyed for in vitro minimal inhibitory concentration (MIC) to 32 drugs by microdilution test. Clinical categorization of isolates as susceptible or resistant was based on MIC interpretative standards of the National Committee for Clinical Laboratory Standards(NCCLS). None of the strains were susceptible to all antimicrobial compounds tested and most strains (96.6%) were multidrug-resistant. High level resistance to streptomycin was also detected. Resistance to sulfonamides (92.3% - 98.3%), aminoglycosides (70.8% - 78.5%), lincosamides (66.2% - 64.6%), tetracyclines (72.3%) and macrolides (53.8% - 67.7%) were most frequent, then beta-lactam (18.5% - 56.9%) and quinolones (36.9% - 78.5%) resistance, while all strains were susceptible to florfenicol, 78.5% strains were susceptible to Taimulin. All resistant strains to beta-lactam were tested for beta-lactamase production and the results were negative.