De novo mutations of STXBP1 in Chinese children with early onset epileptic encephalopathy

To detect syntaxin-binding protein 1 (STXBP1) mutations in Chinese patients with early onset epileptic encephalopathy (EOEE) of unknown etiology. Targeted next-generation sequencing was used to identify STXBP1 mutations in 143 Chinese patients with EOEE of unknown etiology. A filtering process was applied to prioritize rare variants of potential functional significance. Then Sanger sequencing was employed to validate the parental origin of the variants. Detailed clinical and genetic data were collected for 9 STXBP1-positive patients. Eight de novo heterozygous STXBP1 mutations were identified in 9 patients; 5 were novel mutations (c.1155delC, c.1030-1G>A, c.217G>C, c.268G>C, c.1480_1481 insT) and 3 were previously reported (c.1216C> T, c.1217G>A [2 cases], c.875G>A). Two patients had Ohtahara syndrome and 1 had West syndrome at onset, whereas the other 6 presented with EOEE that did not fit a specific recognized epilepsy syndrome. Six of these patients later evolved to West syndrome. All but 2 cases were prescribed more than 2 antiepileptic drugs (AEDs) plus other regimens. Four subjects showed good responses to levetiracetam (LEV) alone or in combination with other AEDs, and one case (1/3) achieved complete freedom from seizures with a ketogenic diet (KD). All patients exhibited severe to profound global developmental delay. Five novel heterozygous de novo STXBP1 mutations were discovered in patients with EOEE from China. STXBP1 mutational analysis should be performed in cases of EOEE of unknown etiology. LEV as monotherapy or adjunctive therapy with other regimens, as well as KD should be considered for management of this patient group.

Trends in drug-resistant tuberculosis in China: data from a clinical tuberculosis centre

OBJECTIVE

To describe the trends in prevalence of drug-resistant tuberculosis (TB) among in-patients in Beijing Chest Hospital, Beijing, China, using a 10-year retrospective study.

DESIGN

From 2005 to 2014, 18 310 in-patients with TB were recruited for the study, most of whom were referrals; no distinction was made between new and previously treated cases. Drug susceptibility testing (DST) was performed in culture-positive cases using the proportion method to determine multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB). Risk factors associated with drug resistance were identified.

RESULTS

A total of 5141 (28.0%) samples were culture-positive. DST results showed that 860 (16.7%) cases were MDR-TB and 176 (3.4%) were XDR-TB. MDR-TB and XDR-TB were detected in respectively 21.2% and 12.5% of new cases. The rate of MDR-TB and XDR-TB gradually increased from 2005, with MDR-TB reaching a peak in 2008 and XDR-TB in 2009. These data closely mirror national survey data on this region, patient age and occupation.

CONCLUSION

Trends in MDR-TB and XDR-TB prevalence during the past decade and their inflection points were determined, which complemented reports from previous national surveys. This information is useful for fighting TB in China.

Effects of fat supplementation on plasma glucose, insulin and fatty acid analysis in ponies maintained on a forage-based diet

The objective of this study was to observe how fat incorporated into an equine forage-based diet through supplementation altered levels of plasma glucose, insulin and fatty acids. Five Shetland/Hackney cross pony mares were fed alfalfa pellet diets top dressed with commercially available vegetable oil (blend of soya bean, canola and corn oils) at 0%, 5%, 10% or 15% of diet. Ponies were randomly assigned one of four diets to start, with a 14-day adjustment period between transitioning to another one of the four diets. Ponies were gradually adapted to the new diet within the 14-day period before a five-day trial period. Each pony received all four diets by the end of the study. Each trial was a five-day period with a three-day sample collection. Blood samples for each collection week were taken 0, 30, 60, 90, 120, 150, 180, 210, 240 and 270 min and at 5, 6, 7, 8, 9 and 10 hr post-feeding. Excess fat did not impact plasma glucose (p > .1), nor did it affect blood plasma insulin concentration. While there was no time alteration found for plasma fatty acid concentration (p > .1), C14:0 increased when ponies were fed 0% fat and C18:2 decreased when ponies were fed 0% fat. Plasma fatty acids (% of total FA) were higher in C18:0, C18:1, C18:2 and C20:1 in the added fat diets (p < .1). These findings suggest the amounts reported in this study of fat supplementation on a forage-based diet did influence the fatty acid analysis within the pony, but did not negatively impact blood glucose and insulin concentrations.

Abstract P5-21-04: Phase I/Ib study of the SERD LSZ102 alone or in combination with ribociclib in ER+ breast cancer

Background: LSZ102 is an orally bioavailable selective estrogen receptor degrader (SERD) that inhibits estrogen receptor (ER) gene transcription, induces receptor degradation, and blocks ER-dependent cell growth in preclinical models. This Phase I/Ib, open-label study is evaluating LSZ102 as a single agent and in combination with the CDK4/6 inhibitor ribociclib (LEE011) or the PI3K inhibitor alpelisib (BYL719) in patients (pts) with locally advanced/metastatic ER-positive (ER+) breast cancer (BC).

Methods: The primary objective is to characterize the safety and tolerability, and identify a recommended dose and regimen of LSZ102 alone (Arm A) or in combination with ribociclib (Arm B) or alpelisib (Arm C). Secondary objectives include evaluation of preliminary antitumor activity and pharmacokinetics (PK). Eligible pts (aged ≥18 yrs; ECOG PS 0-1) have histologically confirmed ER+ BC that has progressed after endocrine therapy.

Results: As of March 14, 2017, dose escalation evaluating 16 pts in Arm A (LSZ102 200 mg [n=4], 400 mg [n=6], and 600 mg [n=6]) had completed (median age 57.5 yrs; 81% ECOG PS 0; 63% received prior fulvestrant). Five pts (median age 59.0 yrs; 80% ECOG PS 0; 60% received prior fulvestrant) had enrolled in the first cohort of Arm B (LSZ102 200 mg QD + ribociclib 300 mg 3 weeks on/1 week off) with evaluation ongoing. Arm C (LSZ102 + alpelisib) had yet to open. As of March 14, 2017, 9/16 (56%) pts in Arm A had discontinued treatment, all due to progressive disease (PD); in Arm B all pts were still receiving treatment. There were no dose-limiting toxicities in either arm at the dose levels evaluated; dose escalation is ongoing. The most common drug-related adverse events (AEs) were diarrhea (Grade [Gr] 1: 7/16; Gr 2: 2/16 pts), nausea (Gr 1: 6/16; Gr 2: 2/16 pts), and vomiting (Gr 1: 3/16 pts) in Arm A, and hot flush, nausea, vaginal discharge (all Gr 1: 2/5 pts), thrombocytopenia (Gr 1: 1/5; Gr 2: 1/5 pts), and neutropenia (Gr 2: 1/5, Gr 3: 1/5 pts) in Arm B. There were no drug-related Gr 3/4 AEs reported in Arm A; in Arm B, Gr 3 neutropenia, leukopenia, and lymphopenia each occurred in 1/5 pts. Preliminary PK assessment showed single-agent LSZ102 exposure increased dose-proportionally from 200 to 600 mg QD. In combination with ribociclib, exposures were consistent with those of the single agent at the same dose. In Arm A, preliminary evidence of antitumor activity was observed. Efficacy data for Arms B and C were not available as of March 14, 2017. One pt, whose tumor harbored an ESR1 D538G mutation, had been treated with multiple prior therapies in the metastatic setting, including letrozole, exemestane, tamoxifen, exemestane + everolimus, and anastrozole, as well as fulvestrant for 120 days prior to PD, and letrozole + palbociclib for 94 days prior to PD. As of March 14, 2017, this pt had been on LSZ102 treatment (400 mg QD) for 167 days, with a best response of stable disease (14% reduction in sum of diameter of target lesions).

Conclusions: Oral single-agent LSZ102 appears well-tolerated, with a manageable safety profile. Preliminary data also suggest tolerability when combined with ribociclib. Preliminary evidence of single-agent antitumor activity was seen in heavily pretreated pts with ER+ BC in a post-fulvestrant setting.

Citation Format: Juric D, Curigliano G, Cresta S, Yap Y-S, Terret C, Duhoux FP, Takahashi S, Kundamal N, Bhansali S, Liao S, Crystal A, Jhaveri K. Phase I/Ib study of the SERD LSZ102 alone or in combination with ribociclib in ER+ breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-04.

Expression of BrpA in Streptococcus mutans is regulated by FNR-box mediated repression

Our previous studies showed that brpA in Streptococcus mutans, which encodes a member of the LytR-CpsA-Psr family of proteins, can be co-transcribed with brpB upstream as a bicistronic operon, and the intergenic region also has strong promoter activity. To elucidate how brpA expression is regulated, the promoter regions were analyzed using polymerase chain reaction-based deletions and site-directed mutagenesis and a promoterless luciferase gene as a reporter. Allelic exchange mutagenesis was also used to examine genes encoding putative trans-acting factors, and the impact of such mutations on brpA expression was analyzed by reporter assays. Multiple elements in the short brpA promoter (nucleotide -1 to -344 relative to start cordon ATG) were shown to have a major impact on brpA expression, including an FNR-box, for a putative binding site of an FNR-type of transcriptional regulator. When compared with the intact brpA promoter, mutations of the highly conserved nucleotides in FNR-box from TTGATgtttAcCtt to TTACAgaaaGtTac resulted in 1362-fold increases of luciferase activity (P < .001), indicative of the FNR-box-mediated repression as a major mechanism in regulation of brpA expression. When luciferase reporter was fused to the upstream brpBA promoter (nucleotides -784 to -1144), luciferase activity was decreased by 4.5-fold (P < .001) in the brpA mutant, TW14D, and by 67.7-fold (P < .001) in the brpB mutant, JB409, compared with the wild-type, UA159. However, no such effects were observed when the reporter gene was fused to the short brpA promoter and its derivatives. These results also suggest that brpA expression in S. mutans is auto-regulated through the upstream brpBA promoter.

[Prostaglandin-associated periorbitopathy]

Glaucoma is one of the leading causes of blindness in the world, second to cataract. The treatment of glaucoma mainly includes drugs, laser and operation, which can slow down the progress of the disease. Prostaglandin is the first-line medication at present. With the constant promotion of clinical application, the local side effects have been found, such as conjunctival congestion, lash lengthening, periorbital and iris pigment deepening, blepharitis and macular edema. As people pay more attention to appearance, periorbitopathy caused by prostaglandin has been reported in recent years, including upper eyelid ptosis and dermatochalasis, deepening of the upper eyelid sulcus, periorbital fat loss, enophthalmos and inferior scleral exposure. The mechanism, performance and treatment methods of these prostaglandin-associated periorbitopathies are reviewed. (Chin J Ophthalmol, 2017, 53: 637-640).

Quantitative structure-activity relationship study of amide mosquito repellents

A quantitative structure-activity relationship (QSAR) study on 43 amide repellents was carried out by the heuristic method in order to reveal the correlations between molecular parameters of these amides and their repellency against Aedes aegypti. Sketches and optimizations of molecular structures were achieved by the Gaussian software package. Generation and screening of molecular parameters were accomplished using CODESSA 2.7.10 software. The leave-one-out method was applied for the model validation. The results showed that a four-descriptor QSAR model with r² of 0.897 was obtained. The average r² values of the training set and test set of the QSAR model were 0.901 and 0.863, respectively, which suggested that the stability and predictability of the model were confirmed. Analysis of the implications of the descriptors that constitute the QSAR model indicated that all the descriptors were related to the charge distribution over the molecule and affect the dipole moment of the repellents.

Mediating effect of coping styles on the association between psychological capital and psychological distress among Chinese nurses: a cross-sectional study

WHAT IS KNOWN ON THE SUBJECT?: Studies show that psychological capital (PsyCap) is a protective factor against psychological distress, such as depressive symptoms. However, few have attempted to address the role of coping styles in the relationship between PsyCap and psychological distress. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: Our study found moderate levels of PsyCap among nurses in China. Among the subcategories of PsyCap, optimism and hope were most highly correlated with psychological distress. Psychological distress was positively associated with negative coping and negatively associated with positive coping. This study confirmed the partial mediating effect of coping styles in PsyCap and psychological distress among Chinese nurses. In other words, this study found direct and indirect effects of PsyCap on psychological distress mediated via coping styles. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The significant mediating effect of negative and positive coping styles between PsyCap and psychological distress has implications for hospital administrators, especially nurse leaders. Effective strategies should be implemented to improve PsyCap and coping styles among Chinese nurses, and alleviate psychological distress. Optimism and hope should be emphasized in PsyCap investment. Different styles of coping are influenced and modified by teaching and experience. Therefore, it is essential that nurse managers organize educational and training programmes to provide nurses with relative coping knowledge and techniques, and improve their coping ability. Several studies suggest that coping styles are affected by social support. Thus, nurse managers should assist nurses with social support and enhance coping strategies to reduce psychological distress.

ABSTRACT

Introduction PsyCap includes four categories namely self-efficacy, hope, optimism and resilience. Research has demonstrated that PsyCap and coping styles affect current psychological distress. Nevertheless, few studies have explored the role of coping styles in PsyCap and psychological distress. Aim This study investigated the role of coping styles as a mediator in PsyCap and psychological distress among Chinese nurses. Methods Participants included 538 nurses who completed self-report questionnaires assessing PsyCap, coping styles and psychological distress. Linear regression analyses were used to explore the role of coping styles. Results PsyCap, coping styles and psychological distress were significantly correlated. Among the subcategories of PsyCap, optimism and hope were most highly correlated with psychological distress. Coping styles is a partial mediator of PsyCap and psychological distress. Implications for mental health nursing The significant role of negative and positive coping styles in PsyCap and psychological distress has implications for hospital administrators, especially nurse leaders. Effective strategies should be implemented to improve PsyCap and coping styles among Chinese nurses, to alleviate psychological distress. Optimism and hope should be the focus of the improvement. Different styles of coping are developed from education and experience. Therefore, it is necessary for nurse managers to organize educational and training programmes to improve coping skills among nurses. Studies suggest that coping styles are affected by social support. Thus, nurse managers should also assist nurses with social support and enhance coping strategies to reduce psychological distress.

68 GROWTH AND MARKET QUALITY OF PIGS BORN FROM MAGNETIC NANOPARTICLE-TREATED BOAR SPERMATOZOA

Sperm ejaculates contain a heterogeneous population of nonviable and viable spermatozoal cells. Ejaculates with high concentrations of poor quality or damaged spermatozoa can greatly impair the overall fertility of males. Recently, a novel technique termed nanopurification has been developed (Feugang et al. 2015 IVF Reprod. Med. Genet. 3, 2) to noninvasively target and remove poor quality spermatozoa from boar semen. Such removal will enrich insemination doses with high quality spermatozoa to enhance fertility successes. However, effects associated with offspring born from nanopurified semen and possible meat quality assurance have yet to be extensively studied. The objective of this study was to measure the growth performance and market characteristics of pigs born from standard or nanopurified spermatozoa. Boar semen was obtained in insemination doses from a local stud and was mixed with (nanopurified) magnetic nanoparticles (iron-oxide) specifically designed to interact with acrosome-reacted and apoptotic spermatozoa. After incubation, mixed semen were placed under an electromagnetic field trapping moribund sperm to allow collection of intact and viable spermatozoa. Six gilts were bred with standard non-purified (control; n = 3) or nanopurified (n = 3) semen, with subsequent pregnancies leading to full-term birth of viable offspring. At weaning, pigs of equal sexes (5 male and 5 female) were randomly selected from control (n = 10) and nanopurified (n = 10) litters. Pigs were fed and measured until market weight, at which meat quality and carcass characteristics were assessed. Data (mean ± SEM) were analysed with Student’s t-test and SAS software (SAS Institute Inc., Cary, NC, USA). The threshold of significance was set as P < 0.05. Patterns of growth between groups were comparable up to market size (P > 0.05). Standard pork quality parameters (lean carcass weight, loin eye area, percentage of lean cuts, loin and ham colouring, etc.) revealed no significant differences between groups (P > 0.05). Dressing percentage was found higher in the nanopurified group compared with control, with a 1.5% increase (P < 0.05). Marbling score tended to be significantly higher in the nanopurified group (2.7 ± 0.15) when compared with the control (2.3 ± 0.15). Findings indicate that sperm nanopurification does not impair growth of offspring and could ultimately lead to a higher pork carcass quality. Additional research is being conducted to confirm current findings and identify further effects of nanopurification regarding offspring and carcass quality. This work was supported by USDA-ARS Grant #58–6402–3-018.

64 EFFECTS OF NANOPURIFIED BOAR SEMEN FOR ARTIFICIAL INSEMINATION ON PROTEIN DETECTION IN SWINE OFFSPRING MUSCLE AND FAT TISSUE

Standard extended semen contains both viable and non-viable spermatozoa. Magnetic nanoparticles have proven to be effective in the purification of boar semen by targeting nonviable spermatozoal cells (Feugang et al. 2015 IVF Reprod. Med. Genet. 3, 2), allowing potentially greater efficiency within the pork production industry. Previous research lacks data regarding the biochemical effects on offspring produced from such nanopurified semen. Here, we aim to determine whether there is a difference in protein expression between offspring produced with standard and nanopurified semen. Myoglobin (MYO) and fatty acid synthase (FAS) were chosen as the protein markers for this study because they are often studied in reference to meat quality. Myoglobin provides meat its red colour, and FAS assembles fatty acids contributing to tenderness and palatability. The results produced here will provide a baseline for further research in the meat quality and the safety of consuming meat produced with this nanopurification method. Six sows maintained on our experimental farm were inseminated with standard (CTRL) and nanopurified (NANO) boar semen, leading to the birth of viable full-term piglets. At weaning, 10 pigs (5 male and 5 female) were randomly selected from each group and allowed to grow to market weight. Samples of longissimus muscle and SC back fat were then collected from each pig and prepared for protein analyses. Western immunoblotting and immunofluorescence of tissue samples were performed using anti-MYO and anti-FAS antibodies. Images were appropriately captured and quantified (ImageJ). Data (mean ± SEM) were analysed (ANOVA/Wilcoxon) with P < 0.05 set as threshold of significance. Western immunoblotting confirmed the specificity of each antibody. Myoglobin and FAS proteins were highly detected in muscle and fat tissues, respectively, and there were no differences between groups for each protein. Compared with the CTRL group, immunofluorescence signals of MYO in fat tissues and FAS in muscle tissues were significantly reduced in NANO group pigs, irrespective of the sex. However, MYO immunofluorescence levels in fat tissues and FAS levels in all tissues were significantly reduced in females of the NANO group compared with their counterparts in the CTRL group. In conclusion, MYO and FAS proteins were confirmed as good markers for muscle and fat tissues, respectively, with similar immunofluorescence levels between CTRL and NANO groups. Current preliminary data also show that sperm nanopurification (1) may decrease FAS protein expression in muscle tissue with the possibility to affect meat quality and (2) mainly affected females in this study. Further studies are needed for confirmation of these early findings.

Ethnicity as an independent predictive factor for the results of computed tomography pulmonary angiography and ultrasonography of the lower limbs

BACKGROUND

Asians, Pacific Islanders and Maori have significantly lower rates of venous thromboembolism (VTE) compared to Europeans, but its clinic implication regarding diagnosis and prevention is unclear.

AIMS

To investigate if ethnicity affects the yield of computed tomography pulmonary angiography (CTPA) and ultrasonography of the lower limbs.

METHODS

Data previously collected for 523 patients from another study were used to analyse the effect of ethnicity on the results of CTPA; 1587 consecutive ultrasonography of lower limbs was retrospectively analysed according to ethnicity. The Wells score was retrospectively calculated to determine the pretest probability of VTE.

RESULTS

The positive rates of CTPA were 23.3% for European patients and 9.3% for non-European patients. The rate ratio was 2.50 (confidence interval [CI] 1.27-4.95). European patients were 2.5 times more likely to have a positive scan result than non-Europeans, given same pretest probability. There was a larger difference among patients with low and moderate pretest probability with a rate ratio of 4.27 (CI 1.62-11.3). The positive rates of ultrasound scans (USS) among European patients were 16.6 and 9.0% for non-European patients. Rate ratio was 1.85 (CI 1.27-4.95). The difference was also more significant amongst patients with low and moderate pretest probability. The rate ratio was 2.31 (CI 1.38-3.86) for European patients compared to non-European patients.

CONCLUSION

Given the same pretest probability according to the Wells score, European patients had significantly higher positive rates of CTPA and ultrasonography of the lower limbs than non-European patients. Further prospective studies are required to confirm our findings and establish an appropriate pretest assessment tool for non-European patients.

[Effects of autologous adipose-derived stromal vascular fraction on erectile dysfunction of hypertensive rats]

OBJECTIVE

To study the effect of autologous adipose stromal vascular fraction (SVF) injection into corpora cavernosa on the hypertension-associated erectile dysfunction (ED) in rats and its possible mechanism.

METHODS

Healthy male spontaneously hypertensive rats (SHR) at 30-week (n=40) and homologous rats with normal blood pressure (WKY) (n=20) were selected. Noninvasive blood pressure meter was used to measure the systolic blood pressure (SBP) at the tail. Cervical subcutaneous injection of apomorphine was applied to test penile erectile function. The rats with ED were divided into hypertension-associated ED rats treated with autologous SVF injection into corpora cavernosa (ED-SHR-SVF group) (n=8) and hypertension-associated ED rats treated with phosphate buffered saline (PBS) injection into corpora cavernosa (ED-SHR-PBS group) (n=8). The intracavernosal pressure (ICP) was measured in each group. Western blot and RT-PCR were conducted to test protein and mRNA expressions of endothelial nitric oxide synthase (eNOS) in corpora cavernosa.

RESULTS

The tail SBP in SHR rats was significantly higher than that in WKY rats ((197.47±6.82) mmHg vs (125.23±4.65) mmHg, P<0.05). The erectile rate in SHR rats was 60% (24/40), and that in WKY rats was 100% (20/20). After 5 V electrical stimulation, the ICP in the ED-SHR-SVF group was significantly higher than in the ED-SHR-PBS group ((83.42±3.21) mmHg vs (52.37±3.11) mmHg, P<0.05). The protein and mRNA expressions of eNOS in the ED-SHR-SVF group were significantly higher than in the ED-SHR-PBS group (0.43±0.03 vs 0.18±0.05, 0.92±0.05 vs 0.41±0.06, both P<0.05).

CONCLUSIONS

High blood pressure can cause ED in rats, which could be mitigated by autologous SVF injection. The mechanism may be related to up-regulation of eNOS expression in corpus cavernosa.

151 COMPARATIVE ANALYSIS OF FRESH AND CRYOPRESERVED BOAR SPERMATOZOA USING RNA SEQUENCING

Fertility of cryopreserved spermatozoa is significantly reduced compared with that of their fresh counterparts, which is certainly due to the inflicted sublethal damage to spermatozoa that is observed at various molecular and cellular levels. The identification and characterisation of this damage will help us better understand sperm cryobiology and therefore develop suitable media and procedures to improve sperm cryopreservation and fertility outcomes, especially in swine. Here, we present our preliminary assessment of RNA pools of fresh and frozen‐thawed spermatozoa using RNA-sequencing technology. Semen ejaculates of 8 fertile boars were harvested and divided into 2 fractions for each ejaculate. Fraction 1 was freshly extended in commercial diluent (FD) and fraction 2 was frozen in 5-mL plastic straws (FT). Both specimens were shipped to our laboratory for analyses. The samples were purified through Percoll gradient centrifugation and resulting motile spermatozoa were washed in cold PBS. Pelleted spermatozoa were used for total RNA extraction, followed by an in-column DNase digestion. Purity and integrity of RNA samples were checked and rRNA depleted. After random priming, 40 million short cDNA reads were produced using Illumina RNA-Seq technology (Illumina Inc., San Diego, CA, USA). All reads were aligned to the pig reference genome and the produced genome-scale transcription maps consisted of both the transcript structure and the expression level of each gene mapped. Analysis of FD sperm RNA revealed a total of 18 357 sequence tags that were successfully mapped to all pig chromosomes and the mitochondrial genome. Frozen‐thawed spermatozoa showed only 16 864 sequence tags. In both FD and FT samples, chromosomes 1, 2, 6, 7, and 13 contained, in total, the highest density of mapped transcripts (>42%). Chromosome Y and mitochondrial RNAs had the lowest sequence tags mapped (<0.08%). A comparative analysis of FD and FT datasets revealed a net decrease in the total number of sequence tags (1493) with each chromosome being affected, except mitochondria. Chromosomes of FT samples showed a strong (>10%; 17, 7, 4, Y, and X) to moderate (10 to 5%) or weak (≤5%) reduction in RNA numbers. Structural annotation revealed a diverse population of sperm transcripts comprising both coding (mRNA) and noncoding (rRNA, snRNA, and mtRNA) RNAs. In both FD and FT samples, noncoding RNAs were among the most abundant sequence tags. Approximately 12 355 of sequence tags in FD v. 10 948 in FT spermatozoa were annotated with ENSEMBL and the selected genes are under investigation for comparative analyses using RT-PCR. In conclusion, mature boar spermatozoa contain a large pool of coding and non-coding RNAs that can be affected by the freezing-thawing procedure. Inflicted damage affects RNAs of all chromosomes with a great effect being seen on chromosome X. Generated datasets have the potential to lead to further study of the cryo-damage associated with reduced fertility of cryopreserved spermatozoa. Study was supported by USDA-ARS Biophotonics initiative grant # 58-6402-3-0120 and MAFES-SRI grants.

Production of succinic acid from sugarcane molasses supplemented with a mixture of corn steep liquor powder and peanut meal as nitrogen sources by Actinobacillus succinogenes

The potential of using corn steep liquor powder (CSLP), peanut meal (PM), soybean meal (SM), cotton meal (CM) and urea as the substitute of yeast extract (YE) as the nitrogen source was investigated for producing succinic acid (SA). Actinobacillus succinogenes GXAS137 was used as the fermenting bacterium and sugarcane molasses was used as the main substrate. None of these materials were able to produce SA as high as YE did. The CSLP could still be considered as a feasible and inexpensive alternate for YE as the yield of SA produced using CSLP was second only to the yield of SA obtained by YE. The use of CSLP-PM mixed formulation (CSLP to PM ratio = 2·6) as nitrogen source produced SA up to 59·2 g l(-1) with a productivity of 1·2 g l(-1) h(-1). A batch fermentation using a stirred bioreactor produced up to 60·7 g l(-1) of SA at the same formulation. Fed-batch fermentation that minimized the substrate inhibition produced 64·7 g l(-1) SA. These results suggest that sugarcane molasses supplemented with a mixture of CSLP and PM as the nitrogen source could be used to produce SA more economically using A. succinogenes. Significance and impact of the study: Succinic acid (SA) is commonly used as a platform chemical to produce a number of high value derivatives. Yeast extract (YE) is used as a nitrogen source to produce SA. The high cost of YE is currently the limiting factor for industrial production of SA. This study reports the use of a mixture of corn steep liquor powder (CSLP) and peanut meal (PM) as an inexpensive nitrogen source to substitute YE. The results showed that this CSLP-PM mixed formulation can be used as an effective and economic nitrogen source for the production of SA.

The mitochondrial thioredoxin is required for liver development in zebrafish

Thioredoxins (Trxs) are a class of small molecular redox proteins that play an important role in scavenging abnormally accumulated reactive oxygen species (ROS). Thioredoxin 2 (Trx2) is one member of this family located in mitochondria. Trx2 protects cells from increased oxidative stress and has anti-apoptosis function. Knockout of Trx2 in mice led to early embryonic lethality. However, the essential role of Trx2 during embryogenesis remains unclear. To further investigate the role of Trx2 during embryonic development, we performed Trx2 knockdown in zebrafish and investigated the regulation role of Trx2 during embryonic development. Our results indicate that Trx2 had a high expression in early zebrafish embryos and its knockdown in zebrafish led to defective liver development mainly due to increased hepatic cell death. The increased ROS and the imbalance of members of the Bcl-2 family were involved in cell death induced by Trx2 suppression in zebrafish. The dysregulation of Bax, puma and Bcl-xl promoted the reduction of mitochondrial trans-membrane potential and the mitochondria membrane permeabilization (MMP), which initiated the mitochondrial apoptosis pathway. Additionally, we found that the increase of relocated GAPDH in mitochondria may be another factor responsible for the mitochondrial catastrophe.

Review on ultrasonic fabrication of polymer micro devices

Fabrication of micro devices from thermoplastic polymers by ultrasonic processing has become a promising new technology in recent years. Microstructures are generated on polymer surfaces with cycle times of a few seconds and are tightly sealed in even shorter times. Investment costs and energy consumption are comparatively low and processes are very flexible enabling economic fabrication even for small-scale production. For large-scale production role-to-role fabrication has been shown reducing costs even more. A variety of micro devices have been introduced up to now mostly for microfluidic applications. Besides this, electronic circuit boards are fabricated by ultrasonic processing.

Deficiency of PdxR in Streptococcus mutans affects vitamin B6 metabolism, acid tolerance response and biofilm formation

Streptococcus mutans, a key etiological agent of the human dental caries, lives primarily on the tooth surface in tenacious biofilms. The SMU864 locus, designated pdxR, is predicted to encode a member of the novel MocR/GabR family proteins, which are featured with a winged helix DNA-binding N-terminal domain and a C-terminal domain highly homologous to the pyridoxal phosphate-dependent aspartate aminotransferases. A pdxR-deficient mutant, TW296, was constructed using allelic exchange. PdxR deficiency in S. mutans had little effect on cell morphology and growth when grown in brain heart infusion. However, when compared with its parent strain, UA159, the PdxR-deficient mutant displayed major defects in acid tolerance response and formed significantly fewer biofilms (P < 0.01). When analyzed by real-time polymerase chain reaction, PdxR deficiency was found to drastically reduce expression of an apparent operon encoding a pyridoxal kinase (SMU865) and a pyridoxal permease (SMU866) of the salvage pathway of vitamin B6 biosynthesis. In addition, PdxR deficiency also altered the expression of genes for ClpL protease, glucosyltransferase B and adhesin SpaP, which are known to play important roles in stress tolerance and biofilm formation. Consistently, PdxR-deficiency affected the growth of the deficient mutant when grown in defined medium with and without vitamin B6 . Further studies revealed that although S. mutans is known to require vitamin B6 to grow in defined medium, B6 vitamers, especially pyridoxal, were strongly inhibitory at millimolar concentrations, against S. mutans growth and biofilm formation. Our results suggest that PdxR in S. mutans plays an important role in regulation of vitamin B6 metabolism, acid tolerance response and biofilm formation.

Antibacterial dental composites with chlorhexidine and mesoporous silica

One of the leading causes for the failure of dental composite restorations is secondary caries. Effectively inhibiting cariogenic biofilms and reducing secondary caries could extend the service life of composite restorations. Dental composites releasing antibacterial agents such as chlorhexidine (CHX) have shown biofilm-inhibitory efficacy, but they usually have poor physical and mechanical properties. Herein, we present a study of a new method to encapsulate and release CHX from dental composite using mesoporous silica nanoparticles (MSNs). SBA-15 MSNs were synthesized according to a reported procedure. CHX (62.9 wt%) was encapsulated into dried MSN from 0.3 M CHX ethanol solution. The dental composites containing 0% (control), 3%, 5%, and 6.3% CHX or the same amounts of CHX entrapped in MSN (denoted as CHX@MSN) were fabricated with methacrylate monomers and silanized glass fillers (CHX or CHX@MSN + glass filler particle = 70 wt%). The monomer mixture consisted of bisphenol A glycidyl methacrylate (BisGMA), hexanediol dimethacrylate (HDDMA), ethoxylated bisphenol A dimethacrylate (EBPADMA), and urethane dimethacrylates (UEDMA) at a weight ratio of 40:30:20:10. The composites were tested for CHX release and recharge, flexural strength and modulus (at 24 hr and 1 mo), surface roughness, in vitro wear, and antibacterial activity against Streptococcus mutans and Lactobacillus casei (in both planktonic growth and biofilm formation). The results showed that the composites with CHX@MSN largely retained mechanical properties and smooth surfaces and showed controlled release of CHX over a long time. In contrast, the composites with directly mixed CHX showed reduced mechanical properties, rough surfaces, and burst release of CHX in a short time. The composites with CHX either directly mixed or in MSN showed strong inhibition to S. mutans and L. casei. This research has demonstrated the successful application of MSNs as a novel nanotechnology in dental materials to inhibit oral biofilm without sacrificing materials' mechanical properties and surface integrity.

Green synthesis of reduced graphene oxide and its reinforcing effect on natural rubber composites

A green and facile approach to produce graphene using an environmentally friendly reagent, namely proanthocyanidin (PC) as a reducing agent was developed. The obtained graphene (PC-rGO) was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis and X-ray photoelectron spectroscopy, confirming the effective reduction of GO. With the incorporation of PC-rGO into natural rubber (NR) latex, NR/PC-rGO composites were then prepared by an ultrasonically assisted latex mixing and the co-coagulation. The results show that PC-rGO presents a good dispersion and exfoliation in the NR matrix, contributing to an increase in the mechanical performance. Compared with neat NR, the tensile strength, modulus at 300%, and tear strength for NR composites containing 0.9 phr PC-rGO were increased by 50.2%, 154.9% and 65.2%, respectively. With increasing PC-rGO loading, cross-link density and storage modulus of NR composites increase because of the formation of cross-link points and physical interaction between PC-rGO and the matrix.