Protective effects of protocatechuic acid on growth performance, intestinal barrier and antioxidant capacity in broilers challenged with lipopolysaccharide

'Prohibition of the antibiotic uses' aggravates the problem of intestinal diseases in poultry, and nutritional regulation has become a research hotspot, such as supplementation with active ingredients derived from plants. This research was conducted to investigate the effects of protocatechuic acid (PCA) on growth, intestinal barrier, and antioxidant capacity of broilers injected with lipopolysaccharide (LPS). Four hundred and eighty 1-day-old yellow feather broilers were randomly allocated to four groups, each with six replicates of 20 broilers. The treatments were basal diet + saline injection (CON) or LPS injection (CON-LPS), and diets with 300 or 600 mg/kg PCA supplementation + LPS injection (P300, P600). Birds were injected intramuscularly on 17th and 19th day of age, then sampled on day 21. The LPS injection significantly decreased BW and average daily gain of broilers, and compared with birds in CON-LPS, PCA supplementation increased (P < 0.05) those variables; moreover, 300 mg/kg PCA also decreased the feed-to-gain ratio. No differences were observed in relative weights of immune organs (P > 0.05). LPS decreased the villus height/crypt depth ratio (V/C) in jejunum of broilers, while PCA (P300 and P600) increased (P < 0.05) the jejunal villus height and V/C compared with birds in CON-LPS. LPS challenge increased jejunal malondialdehyde (MDA) concentration and decreased total superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) activities in plasma (P < 0.05); compared with birds in CON-LPS, jejunal and plasmal GSH-Px activity (P300 and P600) and jejunal T-SOD activity (P300) were decreased (P < 0.05), and hepatic MDA concentration (P600) was increased (P < 0.05). LPS significantly decreased the transcript abundances of OCLN, ZO-1, JAM2, MUC2, SOD1, CAT and GPX in jejunal mucosa of birds, and supplementation with PCA attenuated the decrease in OCLN, JAM2, and MUC2 expression compared with birds in CON-LPS; moreover, 600 mg/kg PCA offset the deduction in SOD1, CAT and GPX expression. In conclusion, dietary supplementation with PCA could improve antioxidant status and attenuate the damage in intestinal barrier and loss in growth performance of LPS-challenged broilers, and 600 mg/kg PCA showed more improved effects on antioxidant capacity.

[Investigation of occupational noise exposure and hearing loss among automobile manufacturing workers]

Objective: To investigation the situation of occupational noise exposure and hearing loss among workers in automobile manufacturing enterprise during 2017-2019 in Wuhan. Methods: Workers in automobile manufacturing who underwent physical examination in Wuhan Hospital for the Prevention and Treatment of Occupational Diseases from 2017 to 2019 were included as subjects in the cross-sectional survey. Questionnaire survey, noise detection and pure tone threshold test were used. Excluding individuals with working time less than 3 years and information deficiency, 3 948 individuals were finally included in the study. Results: Among 3 948 workers, 128 workers had hearing loss and the rate of hearing loss was 3.24%, among which 101 workers had high-frequency hearing loss and 27 workers were diagnosed as occupational noise deafness. The prevalence of hearing loss among workers previously exposed to noise was significantly higher than that without prior exposure (12.10%, 0.96%, P<0.05) . The prevalence of hearing loss among workers with occupational noise exposure <80 dB (A) , 80~<85 dB (A) and ≥85 dB (A) was 1.83%, 2.69% and 5.09%, respectively. The prevalence of high frequency hearing loss was 1.60%, 2.05% and 3.71%, respectively. The prevalence of occupational noise deafness was 0.23%, 0.64% and 1.38%, respectively. The prevalence of hearing loss and high frequency hearing loss among workers exposed to different occupational noise was statistically significant (P<0.05) , while the prevalence of occupational noise deafness was not statistically significant (P>0.05) . There were statistically significant differences in the prevalence of hearing loss (2.88%, 4.45%) and occupational noise deafness (0.46%, 1.41%) between those who used protective equipment and those who did not (P<0.05) . Compared with workers exposed to occupational noise <80 dB (A) , workers exposed to occupational noise ≥85 dB (A) had A 3.16-fold increased risk of hearing loss (OR=3.16, 95%CI: 1.44~6.95, P<0.05) . Compared to workers using hearing protective equipment, the risk of hearing loss (OR=1.96, 95%CI: 1.25~3.06, P<0.05) and occupational noise deafness (OR=3.46, 95%CI: 1.51-7.96, P<0.05) significantly increased among those without using hearing protective equipment. Conclusion: The risk of hearing loss in automobile manufacturing workers is significantly associated with occupational noise exposure and the use of hearing protective equipment. Good hearing protection may reduce the risk of occupational noise-induced hearing loss and occupational noise deafness.

[Correlation analysis between Dx-pH monitoring and proton pump inhibitor test in the diagnosis of laryngopharyngeal reflux disease]

Objective: The consistency of 24-hour oropharyngeal Dx-pH monitoring and proton pump inhibitor(PPI) test in the diagnosis of laryngopharyngeal reflux disease (LPRD) was investigated. Methods: Sixty patients with laryngopharyngeal reflux (LPR) related symptoms who had never received PPI treatment were assessed by reflux symptom index (RSI) and reflux finding score (RFS) between October 2017 and October 2018, including 28 males and 38 females, aged from 16 to 72 years, with a medium age of 38 years. Prior to treatment, all patients were evaluated with 24 hours oropharyngeal Dx-pH monitoring(Restech). After empiric therapy with PPI twice-daily for 8 weeks, the efficacy was evaluated according to posttreatment RSI score.The data was analysed with Kruskal-Wallis test, Student Newman Keuls test and consistency check. Results: (1)Among all 60 patients,13 patients (21.7%) had pathologic Ryan score and all resulted responsive to PPI;27 patients (45.0%) with a negative Ryan score were unresponsive to PPI; 20 patients (33.3%) despite a negative Ryan score resulted responsive to PPI therapy. Considering responsiveness to PPI therapy as the gold standard for the diagnosis of LPRD, the sensitivity, specificity, positive predictive value and negative predictive value of Ryan score were 39.4%, 100%, 100% and 57.4% respectively. The Kappa value was 0.369 (P<0.01). (2)Among 34 patients (56.7%) with positive Dx-pH results (24-hour oropharyngeal acid reflux events≥ 3 times), 29 patients were positive and 5 patients were negative in PPI test. Among 26 patients with negative Dx-pH results (24-hour oropharyngeal acid reflux events<3 times), 4 patients were positive and 22 patients were negative in PPI test. Considering responsiveness to PPI therapy as the gold standard for the diagnosis of LPRD, the sensitivity, specificity, positive predictive value and negative predictive value of 24-hour oropharyngeal acid reflux events were 87.9%, 81.5%, 85.3% and 84.6% respectively. The Kappa value was 0.696(P<0.01). Conclusions: There is a positive correlation between 24-hour oropharyngeal Dx-pH monitoring positive results (24-hour oropharyngeal acid reflux events≥3 times) and PPI test in the diagnosis of LPRD. The 24-hour oropharyngeal Dx-pH monitoring can be a promising tool for the diagnosis of suspected LPRD patients, and more sensitive and accurate Dx-pH diagnostic index will be required in the clinic.

Effects of N-carbamylglutamate and L-arginine on gonadotrophin-releasing hormone (GnRH) gene expression and secretion in GT1-7 cells

Recent studies have shown that N-carbamylglutamate (NCG) and arginine (ARG) supplementation improves reproductive performance in livestock. The objectives of the present study were to evaluate the effects of NCG and ARG on GT1-7 cell gonadotrophin-releasing hormone (GnRH) secretion, gene expression and cell proliferation. GT1-7 cells were treated in vitro with different concentrations of NCG (0-1.0mM) or ARG (0-4.0mM) in serum-free medium for 12 or 24h. For GnRH secretion and cell proliferation, GT1-7 cells were more sensitive to NCG than ARG. NCG treatment after 12h increased cell numbers and inhibited GnRH secretion in a dose-dependent manner (P<0.05), although there was no significant effect of NCG on these parameters after 24h culture. ARG treatment decreased GnRH secretion after 24h (P<0.05), whereas it had no effect after 12h. GT1-7 cells express GnRH, Kiss-1 metastasis-suppressor (Kiss1), G-protein coupled receptor 54 (GPR54), neuronal nitric oxide synthase (nNOS) and estrogen receptor α (ERα) genes. High concentrations of NCG (1.0mM) and ARG (4.0mM) inhibited (P<0.05) GnRH and nNOS mRNA abundance in GT1-7 cells. ARG treatment decreased Kiss1 and increased ERα mRNA abundance. Thus, high concentrations of NCG (1.0mM) and ARG (4.0mM) may act both directly and indirectly to regulate GnRH neuron function by downregulating genes related to GnRH synthesis and secretion to slow GnRH production while stimulating GT1-7 cell proliferation.

[Analysis of clinical early warning informations of severe preeclampsia before onset]

Objective: To explore the early warning informations of severepre-eclampsia before onset. Methods: The study was an observational case-control study. The study group consisted of 77 single-pregnancy preeclampsia pregnant women and the control group took 154 normal cases who were delivered to Tianjin Fifth Central Hospital (Peking University binhai Hospital) from January 2014 to December 2017 in the perinatal care referral system in Tianjin. To analyze changes in clinical indicators before the onset of severe pre-eclampsia with statistical methods. Results: Prehypertension, weight gain>0.85 kg/week, fetal growth restriction, edema and decline of plasma albumin, thrombocytopenia, poor compliance, perinatal examinations and examinations in tertiary hospitals were associated with severe pre-eclampsia (P<0.001). Multivariate regression analysis showed that the risk factors of severe preeclampsia were pre-hypertension, weight gain>0.85 kg/week, edema, thrombocytopeniaand poor compliance. The increase in the number of prenatal examinations in tertiary hospitals was a protective factor for severe preeclampsia. Conclusion: Prehypertension, weight gain during pregnancy (>0.85 kg/week), edema, thrombocytopenia, and poor compliance were warning informations of severe pre-eclampsia, and the increased number of prenatal examinations in tertiary hospitals was a protective factor for severe pre-eclampsia.

[Investigation of neck and shoulder pain among workers in an automobile plant]

Objective: To investigate the prevalence and risk factors of neck and shoulder pain (NSP) among automobile manufacturing workers and to provide a theoretical basis for prevention of NSP. Methods: From November 5 to November 19, 2017, a total 446 works who had worked for more than one year were recruited from an automobile plant by cluster sampling method. Chi square test and unconditional logistic regression were used to exam the relation between influencing factors and NSP. Results: The annual prevalence rate of NSP was 34.8%. Multifactor regression analysis showed that age、work fatigue、department staff shortages、lifting heavy objects in awkward positions、neck flexion foreword and prolong sitting position work were the risk factors of NSP (OR=2.18, 95%CI:1.49~3.18; OR=4.52, 95%CI:1.27~16.00; OR=1.66, 95%CI:1.04~26.68; OR=2.10, 95%CI:1.16~3.81; OR=2.25, 95%CI:1.39~3.66; OR=2.42, 95%CI:1.06~5.56) and work break was the benefit factors of NSP (OR=0.58, 95%CI:0.36~0.94) . Conclusion: The annual prevalence rate of NSP among automobile manufacturing workers was high. Lifing heavy objects、awkward working positions and unreasonable work arrangement were the major risk factors of NSP, and work break can effectively reduce the risk of NSP. Effective ergonomic intervention should be carried out to prevent the occurrence of NSP.

In vitro and in vivo antitumor activity of a novel chlorin derivative for photodynamic therapy

In presented paper, a new chlorin derivative 5,10,15,20-tetrakis[(5-N-morpholino)pentyl] chlorin (TMC) was investigated as a photosensitizer in photodynamic therapy (PDT). Cellular uptake, cytotoxicity, intracellular location, biodistribution and antitumor effects were studied using human esophageal cancer cells (Eca-109) and human cervical cancer cells (Hela) in vitro and an esophageal cancer model in BALB/c nude mice. Cellular uptake and biodistribution of TMC were measured by fluorescence spectrophotometer. Cytotoxicity of TMC against Eca-109 and Hela cells was determined by MTT assay. The intracellular location of TMC was detected with a confocal microscopy. It was showed that TMC could rapidly accumulate in tumor cells and localize in cytoplasm. TMC was found to be low-toxic in dark but extensively photosensitive in vitro. A fast clearance rate of TMC was observed in Eca-109-bearing mice. In particular, TMC could significantly inhibit the tumor growth and exhibit a notable antitumor efficacy for PDT in vivo.

[Influencing factors for reproductive health of female workers in petrochemical industry]

Objective: To investigate the reproductive health status of female workers in petrochemical industry, and to provide a reference for improving reproductive health status and developing preventive and control measures for female workers in petrochemical industry. Methods: A face-to-face questionnaire survey was performed from January to October, 2016. The Questionnaire on Women's Reproductive Health was used to investigate the reproductive health of female workers in petrochemical industry. The multivariate logistic regression model was used to identify the influencing factors for reproductive health of female workers in petrochemical industry. Results: Among the 7485 female workers, 1 268 (40.9%) had abnormal menstrual period, 1 437 (46.4%) had abnormal menstrual volume, 177 (28.5%) had hyperplasia of mammary glands, and 1 807 (24.6%) had gynecological inflammation. The reproductive system diseases in female workers in petrochemical industry were associated with the factors including age, marital status, education level, unhealthy living habits, abortion, overtime work, work shift, workload, video operation, occupational exposure, positive events, and negative events, and among these factors, negative events (odds ratio[OR]= 1.856) , unhealthy living habits (OR=1.542) , and positive events (OR=1.516) had greater impact on reproductive system diseases. Conclusion: Many chemical substances in the occupational environment of petrochemical industry can cause damage to the reproductive system, which not only affects the health of the female workers, but also poses potential threats to the health of their offspring. Occupational exposure, unhealthy living habits, overtime work, and work shift have great influence on reproductive system diseases in female workers.

[Evaluation of the tear film function in diabetic patients using the Keratograph 5M]

Objective: To evaluate the tear film function of diabetic patients using the Keratograph 5M and to analyze its related factors. Methods: Case-control study. A total of 89 inpatients (174 eyes) diagnosed with diabetes in the Department of Endocrinology at our hospital were recruited. According to the fundus fluorescein angiography results, subjects were divided into two groups, diabetic retinopathy (DR) group and none-DR group. All subjects were examined for duration of diabetes, glycosylated hemoglobin, creatinine, 24-hour urinary protein, and 24-hour urinary microalbumin/urinary creatinine, and by electromyography. The Keratograph 5M was used to obtain the first and average tear film break-up time (BUTf and BUTav), tear meniscus height, the upper and lower meibomian gland loss scores. The data were analyzed by SPSS. Results: Compared to the non-DR group, the BUTf and the BUTav in the DR group were shorter [(8.42±4.71) s vs. (10.24±5.32) s, (11.20±5.25) s vs. (12.67±5.52) s; P=0.000]. There was no significant difference in the tear meniscus height between the three groups (P=0.067). The tear meniscus height were negatively related with glycosylated hemoglobin, and not related with duration of diabetes, 24-hour urinary microalbumin/urinary creatinine, creatinine, 24-h urinary protein, and electromyography results. As the duration of diabetic longer, the upper and lower meibomian gland loss scores added(Z=19.514, 15.342, P<0.05). Patients with EMG abnormal, the lower meibomian gland loss scores added(Z=-2.312, P<0.05). Conclusions: The Keratograph 5M can directly evaluate the tear film condition of diabetic patients.Diabetic patients with retinopathy and higher glycosylated hemoglobin tend to suffer tear film dysfunction. (Chin J Ophthalmol, 2018, 54:762-766).

An experimental system for coiled tubing partial underbalanced drilling (CT-PUBD) technique

To improve the rate of penetration (ROP) in hard formations, a new high-speed drilling technique called Coiled Tubing Partial Underbalanced Drilling (CT-PUBD) is proposed. This method uses a rotary packer to realize an underbalanced condition near the bit by creating a micro-annulus and an overbalanced condition at the main part of the annulus. A new full-scale laboratory experimental system is designed and set up to study the hydraulic characteristics and drilling performance of this method. The system is composed of a drilling system, circulation system, and monitor system, including three key devices, namely, cuttings discharge device, rotary packer, and backflow device. The experimental results showed that the pressure loss increased linearly with the flow rate of the drilling fluid. The high drilling speed of CT-PUBD proved it a better drilling method than the conventional drilling. The experimental system may provide a fundamental basis for the research of CT-PUBD, and the results proved that this new method is feasible in enhancing ROP and guaranteeing the drilling safety.

[Stratified sampling survey of major human parasitic diseases in Henan province]

Objective: To understand the prevalence of major human parasitic diseases and related factors in Henan province. Methods: This stratified sampling survey was carried out according to the requirement of national survey protocol of major human parasitic diseases, 2014-2015. The prevalence of soil-transmitted helminths infection, taeniasis and intestinal protozoiasis were surveyed in 104 sites selected from 35 counties (districts) and the prevalence of clonorchiasis was surveyed in 62 sites selected from 37 townships. In each survey spot, 250 persons were surveyed. A total of 26 866 persons and 15 893 persons were surveyed. Modified Kato-Katz thick smear was used to detect the eggs of intestinal helminthes. Tube fecal culture was used to identify the species of hookworm. The Enterobius eggs were detected in children aged 3 to 6 years by using adhesive tape. The cyst and trophozoite of intestinal protozoa were examined with physiological saline direct smear method and iodine stain method. Results: The overall infestation rate of intestinal parasites was2.02% in Henan, and the worm infection rate was higher than protozoa infection rate. Fourteen kinds of intestinal parasites were found, including nematode (5 species), trematode (2 species), and protozoan (7 species). The infection rate of Enterobius vermicularis was highest, and Qinba Mountain ecological area had the highest infestation rate of intestinal parasites in 4 ecological areas of Henan. There was no significant difference in intestinal parasite infection rate between males and females (χ(2)=3.630, P=0.057), and the differences in intestinal parasite infection rate among different age groups had significance (χ(2)=124.783, P=0.000 1). The infection rate reached the peak in age group ≤9 years and the major parasite was Enterobius vermicularis. Furthermore the overall human infection rate of parasite showed a downward trend with the increase of educational level of the people (χ(2)=70.969, P=0.000 1), the differences had significance (χ(2)=120.118, P=0.000 1). For different populations, the infection rate of intestinal parasites was highest among preschool children. The infection of intestinal helminth was mainly mild, only 2 severe cases were detected. The infection rate of Clonorchis sinensis in urban residents was only 0.006%. Logistic regression analysis showed that being preschool children (χ(2)=15.765, P=0.000 1) and drinking well water (χ(2)=45.589, P=0.000 1) were the risk factors for intestinal parasite infection, and annual income per capita of farmers was the protective factor against intestinal parasite infection. The infection rates of protozoa and intestinal parasites decreased sharply compared with the results of previous two surveys, and the rate of intestinal helminth infection also dropped sharply compared with the second survey. The numbers of protozoa, helminth and intestinal parasites detected in this survey were all less than the numbers found in the previous two surveys. Conclusions: Compared the results of three surveys in Henan, the infection rate of protozoa and intestinal parasites showed a downward trend. The prevention and treatment of Enterobius vermicularis infection in children should be the key point of parasitic disease control in the future.

[The clinical study of olfactory dysfunction in IgG4-related disease]

Objective:IgG4-related disease is a newly recognized systemic disease, and its elucidation is progressing. However, little is known about its sinonasal manifestations.The aim of this study was to assess the olfaction of patients with IgG4-related disease.Method:Twenty-two patients with IgG4-related disease underwent the odor stick identification test to measure olfactory function.We analyzed the clinical features, including serum IgG4 levels, involved organs, and sinonasal computed tomography scores to explore the etiology of olfactory dysfunction.Result:Eleven patients with IgG4-related disease were found to have olfactory dysfunction. There were no differences in the clinical features between the olfactory dysfunction group and the normal group.Conclusion:There were no correlation between olfactory function and serum IgG4 level, involved organs or sinonasal computed tomography scores.We found that the prevalence of olfactory dysfunction was high in patients with IgG4-related disease and that it could be reversed.Olfactory dysfunction appears to be a novel important manifestation of IgG4-related disease.

[Effect of umbilical cord mesenchymal stem cell transplantation on immune function and prognosis of patients with decompensated hepatitis B cirrhosis]

Objective: To investigate the effect of human umbilical cord mesenchymal stem cells (hUCMSCs) on the immune function and prognosis of patients with decompensated hepatitis B cirrhosis. Methods: A total of 65 patients with decompensated hepatitis B cirrhosis were divided into observation group and control group. The patients in the observation group were given intervention (via the proper hepatic artery or the portal vein) and intravenous infusion of 4×10⁸ hUCMSCs in two doses, as well as the same basic treatment as in the control group. The patients in the control group were given conventional medical treatment. ELISA as used to measure the serum levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNFα), interleukin-10 (IL-10), and transforming growth factor-β (TGFβ) in the observation group before surgery and at 1 week after surgery, as well as the serum levels of IL-6, TNFα, IL-10, and TGFβ in the control group on admission and at 1 week after admission. Flow cytometry was used to measure the percentage of lymphocyte subsets in the observation group before surgery and at 1 week after surgery, as well as that in the control group on admission and at 1 week after admission. In addition, the patients' prognosis and major complications during hospitalization were observed in both groups, and the patients were followed up for 24 weeks to record the number of deaths. The t-test was used for comparison of continuous data, and the chi-square test was used for comparison of categorical data which were expressed as percentages. Results: At 1 week after the transplantation of hUCMSCs, compared with the control group, the observation group had significant reductions in the serum levels of IL-6 and TNFα and significant increases in the serum levels of IL-10 and TGFβ (all P < 0.001), as well as significant increases in the percentages of T4 cells and Treg cells and significant reductions in the percentages of T8 cells and B cells (all P < 0.05). There were no significant differences in the changes in T3 cells and natural killer cells between the two groups (P > 0.05). Compared with the control group, the observation group had a significantly lower probability of progression to liver failure (6.45% vs 14.71%, P = 0.017). Conclusion: In the treatment of patients with decompensated hepatitis B cirrhosis, transplantation of UCMSCs can inhibit the proliferation of T cells and B cells and the differentiation of T8 cells, upregulate Treg cells, promote the secretion of immunosuppressive cytokines, and reduce the production of inflammatory cytokines. Therefore, it can alleviate liver inflammatory response and liver cell damage and reduce the probability of hepatic failure.

[Effect of fibroblast growth factor 1 on the proliferating cell nuclear antigen expression in submandibular gland of diabetic mice]

Objective: To examine the proliferating cell nuclear antigen (PCNA) expression in submandibular gland of diabetic mice and to investigate the influence of fibroblast growth factor 1 (FGF-1) on PCNA expression and its possible mechanism. Methods: Sixteen db/db diabetic male mice were randomly divided into diabetic group and diabetic-FGF-1 group (n=8). Eight age-matched db/m mice served as a control group. After FGF-1 was administered intraperitoneally to diabetic-FGF-1 group continuously for 16 weeks, blood glucose and body weight of each mouse in the three groups were detected at 0, 4, 8, 12, 16 weeks. Then the flow rate of saliva in three groups was compared at 0, 8, 16 weeks. At 16 week, bilateral submandibular glands were resected. Then HE staining was performed to observe the histological morphology of submandibular gland and PCNA expression was examined by immunohistochemical staining. Results: Four weeks after administration, the blood glucose in diabetic-FGF-1 group decreased markedly, close to the control group (P>0.05). Weight loss in diabetic-FGF-1 group was noticeable at 8 weeks after administration, but still higher than that in the control group (P<0.05). The flow rate of saliva in diabetic-FGF-1 group increased gradually after administration, which was higher at 8, 16 weeks ([260.1±43.3], [308.5±34.0] mg·min(-1)·kg(-1)) respectively than that in the diabetic group at the same time point ([181.8±37.5], [194.9±49.8] mg·min(-1)·kg(-1)) (P<0.05). Compared with the control group, submandibular glands in diabetic group significantly atrophied and the glandular atrophy in diabetic-FGF-1 group was alleviated. The submandibular gland index in the control group, diabetic group and diabetic-FGF-1 group were (7.45±0.63), (2.23±0.26), (3.97±0.15) mg/g, respectively (P<0.05). HE staining showed that the histological morphology of submandibular gland in diabetic-FGF-1 group was clearer, and acinar and ductal atrophy were less significant than diabetic group. Immunohistochemistry showed that the rate of PCNA-positive cells in the control group, diabetic group and diabetic-FGF-1 group were (45.23±7.78)%, (11.50±1.69)%, (36.98±6.53)% respectively (P<0.05). Conclusions: FGF-1 can up-regulate the expression of PCNA in submandibular gland of diabetic mice. This effect may be one of the important mechanisms of FGF-1 reversing the structural atrophy and dysfunction of submandibular gland caused by diabetes mellitus.

Yeast CUP1 protects HeLa cells against copper-induced stress

As an essential trace element, copper can be toxic in mammalian cells when present in excess. Metallothioneins (MTs) are small, cysteine-rich proteins that avidly bind copper and thus play an important role in detoxification. YeastCUP1 is a member of the MT gene family. The aim of this study was to determine whether yeast CUP1 could bind copper effectively and protect cells against copper stress. In this study,CUP1 expression was determined by quantitative real-time PCR, and copper content was detected by inductively coupled plasma mass spectrometry. Production of intracellular reactive oxygen species (ROS) was evaluated using the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) assay. Cellular viability was detected using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, and the cell cycle distribution of CUP1 was analyzed by fluorescence-activated cell sorting. The data indicated that overexpression of yeast CUP1 in HeLa cells played a protective role against copper-induced stress, leading to increased cellular viability (P<0.05) and decreased ROS production (P<0.05). It was also observed that overexpression of yeast CUP1 reduced the percentage of G1 cells and increased the percentage of S cells, which suggested that it contributed to cell viability. We found that overexpression of yeast CUP1 protected HeLa cells against copper stress. These results offer useful data to elucidate the mechanism of the MT gene on copper metabolism in mammalian cells.

Extracellular pH modulates GABAergic neurotransmission in rat hypothalamus

Changes in extracellular pH have a modulatory effect on GABAA receptor function. It has been reported that pH sensitivity of the GABA receptor is dependent on subunit composition and GABA concentration. Most of previous investigations focused on GABA-evoked currents, which only reflect the postsynaptic receptors. The physiological relevance of pH modulation of GABAergic neurotransmission is not fully elucidated. In the present studies, we examined the influence of extracellular pH on the GABAA receptor-mediated inhibitory neurotransmission in rat hypothalamic neurons. The inhibitory postsynaptic currents (IPSCs), tonic currents, and the GABA-evoked currents were recorded with whole-cell patch techniques on the hypothalamic slices from Sprague-Dawley rats at 15-26 postnatal days. The amplitude and frequency of spontaneous GABA IPSCs were significantly increased while the external pH was changed from 7.3 to 8.4. In the acidic pH (6.4), the spontaneous GABA IPSCs were reduced in amplitude and frequency. The pH induced changes in miniature GABA IPSCs (mIPSCs) similar to that in spontaneous IPSCs. The pH effect on the postsynaptic GABA receptors was assessed with exogenously applied varying concentrations of GABA. The tonic currents and the currents evoked by sub-saturating concentration of GABA ([GABA]) (10 μM) were inhibited by acidic pH and potentiated by alkaline pH. In contrast, the currents evoked by saturating [GABA] (1mM) were not affected by pH changes. We also investigated the influence of pH buffers and buffering capacity on pH sensitivity of GABAA receptors on human recombinant α1β2γ2 GABAA receptors stably expressed in HEK 293 cells. The pH influence on GABAA receptors was similar in HEPES- and MES-buffered media, and not dependent on protonated buffers, suggesting that the observed pH effect on GABA response is a specific consequence of changes in extracellular protons. Our data suggest that the hydrogen ions suppress the GABAergic neurotransmission, which is mediated by both presynaptic and postsynaptic mechanisms.

Current status of standardization of acupuncture and moxibustion in China

With the wide-spread and application of acupuncture and moxibustion, the demand of its standardization construction is increasingly prominent. On the basis of further investigation into the standards of acupuncture and moxibustion in China, this article summarize the research status of Chinese standardization of acupuncture and moxibustion, analyse some problems existing in current construction of acupuncture and moxibustion standardization, and put forward several strategies for moving forward, in order to show an overall and objective understanding of acupuncture and moxibustion standardization.

The Arabidopsis anaphase-promoting complex/cyclosome subunit 1 is critical for both female gametogenesis and embryogenesis(F)

Anaphase-promoting complex/cyclosome (APC/C), a multisubunit E3 ligase, plays a critical role in cell cycle control, but the functional characterization of each subunit has not yet been completed. To investigate the function of APC1 in Arabidopsis, we analyzed four mutant alleles of APC1, and found that mutation in APC1 resulted in significantly reduced plant fertility, accumulation of cyclin B, and disrupted auxin distribution in embryos. The three mutant alleles apc1-1, apc1-2 and apc1-3 shared variable defects in female gametogenesis including degradation, abnormal nuclear number, and disrupted polarity of nuclei in the embryo sac as well as in embryogenesis, in which embryos were arrested at multiple stages. All of these defects are similar to those previously identified in apc4. The mutant apc1-4, in which the T-DNA was inserted after the transmembrane domain at the C-terminus, showed much more severe phenotypes; that is, most of the ovules were arrested at the one-nucleate female gametophyte stage (stage FG1). In the apc1 apc4 double mutants, the fertility was further reduced by one-third in apc1-1/+ apc4-1/+, and in some cases no ovules even survived in siliques of apc1-4/+ apc4-1/+. Our data thus suggest that APC1, an essential component of APC/C, plays a synergistic role with APC4 both in female gametogenesis and in embryogenesis.

Tunable radiation source by coupling laser-plasma-generated electrons to a periodic structure

Near-infrared radiation around 1000 nm generated from the interaction of a high-density MeV electron beam, obtained by impinging an intense ultrashort laser pulse on a solid target, with a metal grating is observed experimentally. Theoretical modeling and particle-in-cell simulation suggest that the radiation is caused by the Smith-Purcell mechanism. The results here indicate that tunable terahertz radiation with tens GV/m field strength can be achieved by using appropriate grating parameters.

Quasimonoenergetic proton bunch generation by dual-peaked electrostatic-field acceleration in foils irradiated by an intense linearly polarized laser

It is found that stable proton acceleration from a thin foil irradiated by a linearly polarized ultraintense laser can be realized for appropriate foil thickness and laser intensity. A dual-peaked electrostatic field, originating from the oscillating and nonoscillating components of the laser ponderomotive force, is formed around the foil surfaces. This field combines radiation-pressure acceleration and target normal sheath acceleration to produce a single quasimonoenergetic ion bunch. A criterion for this mechanism to be operative is obtained and verified by two-dimensional particle-in-cell simulation. At a laser intensity of ∼5.5×10(22)  W/cm(2), quasimonoenergetic GeV proton bunches are obtained with ∼100  MeV energy spread, less than 4° spatial divergence, and ∼50% energy conversion efficiency from the laser.

Comparison of biological activated carbon (BAC) and membrane bioreactor (MBR) for pollutants removal in drinking water treatment

Biological activated carbon (BAC) and membrane bioreactor (MBR) were systematically compared for the drinking water treatment from slightly polluted raw water under the same hydraulic retention time (HRT) of 0.5 h. MBR exhibited excellent turbidity removal capacity due to the separation of the membrane; while only 60% of influent turbidity was intercepted by BAC. Perfect nitrification was achieved by MBR with the 89% reduction in ammonia; by contrast, BAC only eliminated a moderate amount of influent ammonia (by 54.5%). However, BAC was able to remove more dissolved organic matter (DOM, especially for organic molecules of 3,000 approximately 500 Daltons) and corresponding disinfection by-product formation potential (DBPFP) in raw water than MBR. Unfortunately, particulate organic matter (POM) was detected in the BAC effluent. On the other hand, BAC and MBR displayed essentially the same capacity for biodegradable organic matter (BOM) removal. Fractionation of DOM showed that the removal efficiencies of hydrophobic neutrals, hydrophobic acids, weakly hydrophobic acids and hydrophilic organic matter through BAC treatment were 11.7%, 8.8%, 13.9% and 4.8% higher than that through MBR; while MBR achieved 13.8% higher hydrophobic bases removal as compared with BAC.

Over-expression of a flower-specific transcription factor gene AtMYB24 causes aberrant anther development

In plants, MYB transcription factors play important roles in many developmental processes and various defense responses. AtMYB24, as a member of R2R3-MYB gene family in Arabidopsis, was found mainly expressed in flowers, especially in microspores and ovules using Northern blots and in situ hybridization. It was further found that the expression of AtMYB24 was tightly regulated during anther development. Over-expression of AtMYB24 in transgenic plants resulted in pleiotropic phenotypes, including dwarfism and flower development defects, in particular, producing abnormal pollen grains and non-dehiscence anthers. Further analysis showed that the anther development of the AtMYB24-ox lines was retarded starting from the anther developmental stages 10-11. At stages 12 and 13, the septum and stomium cells of anthers would not break, and fewer or no fibrous bands were found in the endothecium and connective cells in the AtMYB24-ox plants. Similar aberrant anther phenotype was also observed in the AtMYB24-GR-ox lines treated with dexamethasone (DEX). Quantitative real-time PCR showed expression of genes involved in phenylpropanoid biosynthetic pathway, such as CHS and DFR, and AtGTP2 were altered in AtMYB24-ox lines. These results suggest an important role of AtMYB24 in the normal development of anthers in Arabidopsis.

Cloning, chromosomal localization and expression patterns of porcine Kruppel-like factors 4, -5, -7 and the early growth response factor 2

Kruppel-like factors (KLF) and the early growth response factor 2 (EGR2) are important zinc finger transcription factors in vertebrates. We have cloned the full length coding sequence (CDS) of porcine KLF5, KLF7 and EGR2, which are 1374, 909 and 1416 bp, respectively. KLF4, KLF5 and EGR2 were then chromosomally mapped to porcine 1q28-29, 11q13-14 and 14q23-25, respectively. Moreover, the tissue expression patterns of KLF4, KLF5, KLF7 and EGR2 imply their probable roles in specific tissues. This is the first report of the basic study of these zinc finger transcription factors in pigs; this information will be helpful for future functional studies.

Surface acceleration of fast electrons with relativistic self-focusing in preformed plasma

We report an observation of surface acceleration of fast electrons in intense laser-plasma interactions. When a preformed plasma is presented in front of a solid target with a higher laser intensity, the emission direction of fast electrons is changed to the target surface direction from the laser and specular directions. This feature could be caused by the formation of a strong static magnetic field along the target surface which traps and holds fast electrons on the surface. In our experiment, the increase in the laser intensity due to relativistic self-focusing in plasma plays an important role for the formation. The strength of the magnetic field is calculated from the bent angle of the electrons, resulting in tens of percent of laser magnetic field, which agrees well with a two-dimensional particle-in-cell calculation. The strong surface current explains the high conversion efficiency on the cone-guided fast ignitor experiments.

Suspended aggregates as an immobilization mode for high-density perfusion culture of HEK 293 cells in a stirred tank bioreactor

Cells of the human embryonic kidney cell line (HEK 293) grown in repeated suspension and perfusion systems were characterized and described. Cell aggregates that formed immediately after the HEK 293 cells were inoculated in stirred vessels in serum-containing Dulbecco's modified Eagle's medium (D-MEM)/F-12 medium. The mean diameter of the cell aggregates reflecting the aggregate size increased with culture time, shifting from 63 to 239 mum after 1 and 8 days of culture in spinner flasks, respectively. No significant differences in cell performance were observed between HEK 293 cell populations grown as suspended aggregates and those grown as anchored monolayers. Replacing the D-MEM/F-12 with CD 293 medium caused the compact spherical cell aggregates to dissociate into single cells and small irregular aggregates without any apparent effect on cell performance. Moreover, the spherical cell aggregates could reform from individual cells and small aggregates when exposed to the serum-containing D-MEM/F-12 dominant medium. Perfusion culture of HEK 293 cells grown as suspended aggregates in a 7.5-l stirred tank bioreactor for 17 days resulted in a maximum viable cell density of 1.2 x 10(7) cells ml(-1). These results demonstrate the feasibility and proof-of-concept for using aggregates as an immobilization system in large-scale stirred bioreactors because a small-scale culture can be used as easily as the inoculum for larger bioreactors.

Transient electrostatic fields and related energetic proton generation with a plasma fiber

We observe a hollow structure and a fine ring in the proton images from a petawatt scale laser interaction with a "cone-fiber" target. The protons related to the hollow structure are accelerated from the cone-tip surface and deflected later by a radial electric field surrounding the fiber. Those associated with the fine ring are accelerated from the fiber surface by this radial electric field. This field is found to decay exponentially within 3 ps from about 5 x 10(12) V/m. Two-dimensional particle-in-cell simulations produce similar proton angular distributions.

Demonstration of bulk acceleration of ions in ultraintense laser interactions with low-density foams

Ion acceleration inside low-density foams irradiated by ultraintense laser pulses has been studied experimentally and theoretically. It is found that the ion generation is closely correlated with the suppressed hot electron transport inside the foams. Particle-in-cell simulations suggest that localized electrostatic fields with multi peaks around the surfaces of lamellar layers inside the foams are induced. These fields inhibit hot electron transport and meanwhile accelerate ions inside the foams, forming a bulk acceleration in contrast to the surface acceleration at the front and rear sides of a thin solid target.

Engineering and functional evaluation of a single-chain antibody against HIV-1 external glycoprotein gp120

The HIV-1 envelope glycoprotein surface subunit gp120 is an attractive target for molecular intervention. This is because anti-HIV-1 gp120 neutralizing antibodies display the potential ability to inhibit HIV-1 infection. The present investigation describes the construction of a genetically engineered single chain antibody (scFv102) against HIV-1 gp120, its expression and functional evaluation. The parental hybridoma cell line (102) produces an immunoglobulin directed against the conserved CD4-binding region of gp120. cDNAs encoding the variable regions of the heavy (V(H)) and light (V(L)) chains were prepared by reverse transcription PCR and linked together with an oligonucleotide encoding a linker peptide (Gly(4)Ser)(3) to produce a single chain antibody gene. The resulting DNA construct was cloned into a prokaryotic expression vector (pET28) and recombinant scFv102 was expressed in Eserichia coli as an insoluble protein. The denatured scFv102 was refolded and purified by immobilized metal ion affinity chromatography. Purified scFv102 had the same specificity as the intact IgG in immuno-blotting assays and immuno-fluorescence (IF) detection, but ELISA analyses demonstrated the affinity of scFv102 to be 5-fold lower than that of the parental monoclonal antibody. In neutralization assays, scFv102 at concentrations lower than 40 microg/ml exhibited efficient interference with viral replication and inhibition of viral infection (90%) across a range of primary isolates of subtype B HIV-1. These results suggest that the constructed anti-HIV-1 gp120 scFv102 has good biological activity and can potentially be used for in vitro diagnostic and in vivo therapeutic applications.

Enhancement of energetic electrons and protons by cone guiding of laser light

Energetic electrons and protons are observed when a target consisting of a reentrant cone with a disk at the tip is irradiated by a petawatt (PW) laser at an intensity of approximately 10(19) W cm(-2). The angular distribution of the electrons and protons, dependent on the open angle of the reentrant cone, is found to differ from that in the case when a target with planar geometry is used. Two jet beams are observed, in directions parallel to the cone axis and normal to the cone-shaped wall. The number and cutoff energies of the generated protons are also related to the open angle of the cone. The efficiency of the generation of energetic electrons from the cone target is 2-3 times higher than that from a simple plane target. These results indicate a guiding of the PW laser beam in the cone geometry.

Plasma devices to guide and collimate a high density of MeV electrons

The development of ultra-intense lasers has facilitated new studies in laboratory astrophysics and high-density nuclear science, including laser fusion. Such research relies on the efficient generation of enormous numbers of high-energy charged particles. For example, laser-matter interactions at petawatt (10(15) W) power levels can create pulses of MeV electrons with current densities as large as 10(12) A cm(-2). However, the divergence of these particle beams usually reduces the current density to a few times 10(6) A cm(-2) at distances of the order of centimetres from the source. The invention of devices that can direct such intense, pulsed energetic beams will revolutionize their applications. Here we report high-conductivity devices consisting of transient plasmas that increase the energy density of MeV electrons generated in laser-matter interactions by more than one order of magnitude. A plasma fibre created on a hollow-cone target guides and collimates electrons in a manner akin to the control of light by an optical fibre and collimator. Such plasma devices hold promise for applications using high energy-density particles and should trigger growth in charged particle optics.

Trichomislin, a novel ribosome-inactivating protein, induces apoptosis that involves mitochondria and caspase-3

Trichomislin, a novel ribosome-inactivating protein, was cloned from the genome of Trichosanthes kirilowii Maxim. The gene was recombined to prokaryotic expression vector and the protein was purified by cation-exchange chromatography. The secondary structure of trichomislin was measured by circular-dichroism analysis and the ratios of alpha-helices and beta-sheets were calculated. Trichomislin could inhibit the synthesis of protein in rabbit reticulocyte lysate systems and its reaction mechanism was to inactivate ribosome as an rRNA N-glycosidase. Antitumor analyses indicated trichomislin induced the apoptosis and inhibited the growth of choriocarcinoma cells. Further investigation showed that trichomislin could bind to and enter choriocarcinoma cells, and then increase the caspase-3 activity in a time-dependent manner. At the same time, the concentration of cytochrome c in cytosol increased while that in mitochondria decreased. These results suggested that trichomislin induced apoptosis by releasing cytochrome c from mitochondria which then triggered the caspase family member activation.

Enhanced green fluorescence protein tracks trichosanthin in human choriocarcinoma cells as a feasible and stable reporter

Trichosanthin (TCS) is a ribosome-inactivating protein (RIP) which can inhibit the growth of human choriocarcinoma (JAR) cells. There are no clear mechanisms to discover the interaction pathway and cytotoxicity of TCS in JAR cells. In this paper, we showed the distribution and transport of endogenously expressed TCS in JAR cells. Enhanced Green Fluorescence Protein (EGFP), fused with TCS, was applied as a reporter to track the behavior of TCS in JAR cells. Firstly, we investigated the expression stability of EGFP and physiological effects on JAR cells. A stable cell line expressing EGFP was created, which could reproduce and express EGFP even if transplanted into nude mice. Based on the proved stability and feasibility of EGFP in cultured cells and in vivo, the fusion gene of EGFP and TCS was constructed and transfected into JAR cells by liposome. The fluorescence microscopy showed that TCS-EGFP fusion gene was expressed in JAR cells in 24 to 48 hours and the fluorescence spread in cytoplasm mainly and in nucleus partially, which could trace the distribution and transport of TCS-EGFP in JAR cells. Most of fluorescent cells died after 48 hours for the cytotoxicity of expressed TCS-EGFP. These results first reported a stable expression and tracing method by EGFP in JAR cells, and provided theoretical basis to apply TCS in cancer therapy.

Algal degradation of a known endocrine disrupting insecticide, alpha-endosulfan, and its metabolite, endosulfan sulfate, in liquid medium and soil

The role of algae in the persistence, transformation, and bioremediation of two endocrine disrupting chemicals, alpha-endosulfan (a cyclodiene insecticide) and its oxidation product endosulfan sulfate, in soil (incubated under light or in darkness) and a liquid medium was examined. Incubation of soil under light dramatically decreased the persistence of alpha-endosulfan and enhanced its transformation to endosulfan sulfate, over that of dark-incubated soil samples, under both nonflooded and flooded conditions. This enhanced degradation of soil-applied alpha-endosulfan was associated with profuse growth of indigenous phototrophic organisms such as algae in soil incubated under light. Inoculation of soil with green algae, Chlorococcum sp. or Scenedesmus sp., further enhanced the degradation of alpha-endosulfan. The role of algae in alpha-endosulfan degradation was convincingly demonstrated when these algae degraded alpha-endosulfan to endosulfan sulfate, the major metabolite, and endosulfan ether, a minor metabolite, in a defined liquid medium. When a high density of the algal inoculum was used, both metabolites appeared to undergo further degradation as evident from their accumulation only in small amounts and the appearance of an endosulfan-derived aldehyde. Interestingly, beta-endosulfan was detected during degradation of alpha-endosulfan by high density algal cultures. These algae were also capable of degrading endosulfan sulfate but to a lesser extent than alpha-endosulfan. Evidence suggested that both alpha-endosulfan and endosulfan sulfate were immediately sorbed by the algae from the medium, which then effected their degradation. Biosorption, coupled with their biotransformation ability, especially at a high inoculum density, makes algae effective candidates for remediation of alpha-endosulfan-polluted environments.

Inhibition of type A GABA receptors by L-type calcium channel blockers

Modulation of type A GABA receptors (GABAA) by L-type Ca++ channel blockers was investigated. The dihydropyridines nifedipine and nitrendipine, and the phenylalkylamine verapamil inhibited recombinant rat alpha1beta2gamma2 receptors recorded from human embryonic kidney (HEK) 293 cells; nifedipine at low concentrations also elicited modest stimulatory effects on GABA-gated current. The IC50 for GABA current inhibition was lowest for nitrendipine (17.3 +/- 1.3 microM), so subsequent studies were focused on further exploring its mechanism and possible site of action. When co-applied with GABA, nitrendipine had minimal effects on initial current amplitude, but significantly enhanced current decay rate. Nitrendipine-mediated inhibition was subunit-selective, as its IC50 was 10-fold lower in alpha1beta2 receptors. Nitrendipine's effect in recombinant human alpha1beta2gamma2 receptors was similar (IC50=23.0 +/- 1.3 microM) to that observed in rat receptors of the same configuration, indicating the site of action is conserved in the two species. The inhibitory effects were dependent on channel gating, were independent of transmembrane voltage, and were also observed in GABAA receptors recorded from hypothalamic brain slices. The pharmacologic mechanism of inhibition by nitrendipine was non-competitive, indicating it does not act at the GABA binding site. Nitrendipine block was retained in the presence of the benzodiazepine antagonist flumazenil, indicating it does not interact at the benzodiazepine site. The actions of nitrendipine were not affected by a mutation (beta2T246F) that confers resistance to the channel blocker picrotoxin, and they were not altered in the presence of the picrotoxin site antagonist alpha-isopropyl-alpha-methyl-gamma-butyrolactone, demonstrating nitrendipine does not act at the picrotoxin site of the GABAA receptor. Possible interaction of nitrendipine with the Zn++ site was also eliminated, as mutation of beta2 H267 to A, which confers resistance to Zn++, had no effect on nitrendipine-mediated inhibition. Our data suggest some of the central effects of dihydropyridines may be due to actions at GABAA receptors. Moreover, the effects may be mediated through interaction with a novel modulatory site on the GABAA receptor.

High-energy electrons produced in subpicosecond laser-plasma interactions from subrelativistic laser intensities to relativistic intensities

The characteristics of the forward hot electrons produced by subpicosecond laser-plasma interactions are studied for different laser polarizations at laser intensities from subrelativistic to relativistic. The peak of the hot electron beam produced by p-polarized laser beam shifts to the laser propagation direction from the target normal direction as the laser intensity reaches the relativistic. For s-polarized laser pulse, hot electrons are mainly directed to the laser axis direction. The temperature and the maximum energy of hot electrons are much higher than that expected by the empirical scaling law. The energy spectra of the hot electrons evolve to be a single-temperature structure at relativistic laser intensities from the two-temperature structure at subrelativistic intensities. For relativistic laser intensities, the forward hot electrons are less dependent on the laser polarization under the laser conditions. The existing of a preplasma formed by the laser amplified spontaneous emission pedestal plays an important role in the interaction. One-dimensional particle-in-cell simulations reproduce the most characteristics observed in the experiment.

Energetic electrons emitted from ethanol droplets irradiated by femtosecond laser pulses

We investigate the angular distribution and the energy spectrum of hot electrons emitted from ethanol droplets irradiated by linearly polarized 150-fs laser pulses at an intensity of 10(16) W/cm(2). Two hot electron jets symmetrically with respect to the laser propagation direction are observed within the polarization plane. This is due to the spherical geometry of droplets in the intense laser field. The maximum energy of the hot electrons is found to be more than 600 keV. Particle-in-cell simulations suggest that the resonance absorption is the main mechanism for hot electron generation.

Safety assessment for genetically modified sweet pepper and tomato

The coat protein (CP) gene of cucumber mosaic virus (CMV) was cloned from a Chinese CMV isolate, the CaMV promoter and NOS terminator added and the gene construct was transformed into both sweet pepper and tomato plants to confer resistance to CMV. Safety assessments of these genetically modified (GM) plants were conducted. It was found that these two GM products showed no genotoxicity either in vitro or in vivo by the micronucleus test, sperm aberration test and Ames test. Animal feeding studies showed no significant differences in growth, body weight gain, food consumption, hematology, blood biochemical indices, organ weights and histopathology between rats or mice of either sex fed with either GM sweet pepper or tomato diets compared with those with non-GM diets. These results demonstrate that the CMV-resistant sweet pepper and tomato are comparable to the non-GM counterparts in terms of food safety.

Laminin chain expression suggests that laminin-10 is a major isoform in the mouse hippocampus and is degraded by the tissue plasminogen activator/plasmin protease cascade during excitotoxic injury

Laminins are important components of the extracellular matrix, and participate in neuronal development, survival and regeneration. The tissue plasminogen activator/plasmin extracellular protease cascade and downstream laminin degradation are implicated in excitotoxin-induced neuronal degeneration. To determine which specific laminin chains are involved, we investigated the expression of laminins in the hippocampus, and the cell types expressing them. Reverse transcription-PCR demonstrated that the messenger RNAs for all laminin chains could be detected in the hippocampus. To determine the localization of laminin chain expression, immunostaining was used. This method showed that alpha5, beta1 and gamma1 are most highly expressed in the neuronal cell layers. Immunoblotting confirmed the hippocampal expression of the chains alpha5, beta1 and gamma1, and RNA in situ hybridization showed a neuronal expression pattern of alpha5, beta1 and gamma1. At early time points following intrahippocampal injection of kainate, alpha5, beta1 and gamma1 chain immunoreactivities were lost. In addition, tissue plasminogen activator-deficient mice, which are resistant to kainate-induced neuronal death, show no significant change in laminins alpha5, beta1 and gamma1 after intrahippocampal kainate injection. Taken together, these results suggest that laminin-10 (alpha5-beta1-gamma1) comprises a major neuronal laminin in the mouse hippocampus, and is degraded before neuronal death during excitotoxic injury by the tissue plasminogen activator/plasmin protease cascade. By identifying a neuronal laminin (laminin-10) that participates in neuronal degeneration after excitotoxic injury, this study clarifies the molecular definition of the extracellular matrix in the hippocampus and further defines a pathway for mechanisms of neuronal death.

Propagation of hot electrons through high-density plasmas

Propagation of hot electrons through high-density plasmas generated by femtosecond laser pulses is investigated using three types of target configurations: Al-coated glass, Al and glass separated by a vacuum gap, and Al foil alone. Collimated ionization tracks lasting for 60 ps and extending 150-300 microm in length and 8 microm in cross section are observed via optical probing. For the Al-foil-alone target, a narrow plasma jet is formed at the rear surface in line with the laser. The collimation of the hot electrons may be attributed to a strong self-generated magnetic field in the target.

Third-order harmonic generation by self-guided femtosecond pulses in air

Strong third-order harmonic (TH) emission is observed with a conversion efficiency higher than 10(-3) from a plasma channel formed by self-guided femtosecond laser pulses propagating in air. The main characteristics of TH emission in various conditions and the phase-matching condition between the fundamental and the TH wave are investigated. An optimized condition is found, under which the TH conversion efficiency is maximized. Our experimental results show that radiation of the emission in ultraviolet wavelength range makes a major attribution to TH emission, whereas the effects of self-phase modulation are not important when intense laser pulses interact with gaseous media.

Sequence-specific assignments of proton NMR resonance peaks and analysis of secondary structural elements of LC1, a novel antibacterial polypeptide

LC1 is a type of novel antibacterial polypeptide secreted by a Bacillus subtilis strain. It consists of 47 residues. Using bioengineering, LC1 was expressed in E.coli DH5alpha by using recombinant plasmid PBVAB16. By means of two-dimensional DQF-COSY, TOCSY and NOESY spectroscopies, protons of all 47 residues are identified. The studies show that the secondary structures of LC1 are principally anti-parallel beta sheets and extended conformations. It was speculated that there may be a hydrophobic core around Trp(23) in its three-dimensional structure.

Capillary electrophoresis and circular dichroism study of trichosanthin and its mutants

The type-I ribosome-inactivating protein trichosanthin (TCS) has a broad spectrum of biological and pharmacological activities, including abortifacient, anti-tumor and anti-human-immunodeficiency-virus (anti-HIV). In this study, circular dichroism (CD) and capillary electrophoresis were used for the first time to study TCS and its two TCS mutants of Y55G TCS (tyrosine 55 converted to glycine) and FYY140-142GSA TCS (tripeptide phenylalanine-tyrosine-tyrosine 140-142 converted to glycine-serine-alanine). The results indicated that the substitution of amino acids changed the secondary structures and the hydrophobility of TCS. Moreover, both Y55G TCS and FYY140-142GSA TCS demonstrated attenuated cytotoxicity and reactive oxygen species (ROS) production in human choriocarcinoma cells (JAR cells) as compared to natural TCS and wild-type TCS. Our results demonstrated the cytotoxicity of TCS on JAR cells and TCS-induced production of ROS might be TCS-conformational related, suggesting that CD and capillary electrophoresis study might throw new insight into the anti-tumor and anti-HIV mechanism of TCS.

Jasplakinolide reversibly disrupts actin filaments in suspension-cultured tobacco BY-2 cells

Jasplakinolide is potentially a useful pharmacological tool for the study of actin organization and dynamics in living cells, since it induces actin polymerization in vitro and, unlike phalloidin, is membrane permeative. In the present work, the effect of jasplakinolide on the actin cytoskeleton of living suspension-cultured Nicotiana tabacum 'Bright Yellow 2' cells was investigated. Actin filaments in the living cells were disrupted by jasplakinolide. The effect of jasplakionlide on the actin cytoskeleton was concentration and time dependent. When cells were treated with a moderate concentration (150 nM) of jasplakinolide, cortical actin filaments were disrupted preferentially, whereas actin aggregated at the perinuclear region. With concentrations higher than 400 nM and exposure times longer than 30 min, actin filaments in the cell disappeared completely. The effect of jasplakinolide on the actin cytoskeleton was reversible even at high concentration. Actin bundles appeared first in the perinuclear region within 5 min, and the cortical actin array was reestablished in 15 min, suggesting that actin filaments might be organized at this region.

[Callus induction and regeneration from mature seeds of indica rice minghui 63 and anti-fungal assay of transgenic rice plants]

A large number of callus from mature seeds of indica rice minghui 63 were obtained through pre-induction on medium with 2 mg/L 2,4-D but without inorganic and organic components for 9 days. Trichosanthin gene was transferred into indica rice minghui 63 by using agrobacterium with the help of bombardment and the transgenic plants were obtained by inducing regeneration. Southern and Western blot analysis showed that the trichosanthin gene had been transferred into genome of minghui 63 and expressed in rice plants. The anti-fungal assay suggested that transgenic rice plants enhanced resistance to infection of Pyricularia oryzae.

A new multiflorane triterpenoid ester from Momordica cochinchinensis Spreng

A new triterpenoid ester 3,29-di-O-(p-methoxy)benzoylmultiflora-8-ene-3 alpha,29-diol-7-one from the seeds of Momordica cochinchinensis Spreng has been isolated. Its structure was elucidated by spectroscopic evidence and confirmed by X-ray crystallography.

Crystallization and preliminary crystallographic studies of antibacterial polypeptide LCI expressed in Escherichia coli

LCI is a type of novel antibacterial polypeptide secreted by a Bacillus subtilis strain. It consists of 47 residues with a molecular weight of 5468 Da. Using bioengineering, LCI was expressed in Escherichia coli DH5alpha with recombinant plasmid pBVAB16. It was crystallized using PEG 4000 as a precipitant. The crystal belongs to space group P6(2)22 or P6(4)22, with unit-cell parameters a = b = 29.30, c = 187.09 A, and diffracts to 2.44 A. A set of diffraction data to 2.8 A was collected.