Crystal Structure of the PX Domain of SNX27

SNX27 is a component of the retromer complex essential for the recycling of transmembrane receptors. SNX27 contains the N-terminal Phox (PX) domain that binds inositol 1,3-diphosphate (Ins(1,3)P₂) and is important for the SNX27 localization. Here, we determined the crystal structure of human SNX27 PX domain by X-ray crystallography. We found that the sulfate ion is located in the positively charged lipid-binding pocket of the PX domain, which mimics the phospholipid recognition. In addition, we modelled the SNX27-PX-Ins(1,3)P₂ complex to better understand the mechanism of Ins(1,3)P₂ recognition by the PX domain of SNX27.

Synchrotron radiation micro-tomography for high-resolution neurovascular network morphology investigation

There has been increasing interest in using high-resolution micro-tomography to investigate the morphology of neurovascular networks in the central nervous system, which remain difficult to characterize due to their microscopic size as well as their delicate and complex 3D structure. Synchrotron radiation X-ray imaging, which has emerged as a cutting-edge imaging technology with a high spatial resolution, provides a novel platform for the non-destructive imaging of microvasculature networks at a sub-micrometre scale. When coupled with computed tomography, this technique allows the characterization of the 3D morphology of vasculature. The current review focuses on recent progress in developing synchrotron radiation methodology and its application in probing neurovascular networks, especially the pathological changes associated with vascular abnormalities in various model systems. Furthermore, this tool represents a powerful imaging modality that improves our understanding of the complex biological interactions between vascular function and neuronal activity in both physiological and pathological states.

3D Computed Tomography Mapping of Thoracolumbar Vertebrae Fractures

BACKGROUND Fractures of the thoracolumbar (TL) spine represent 90% of all spinal fractures, followed by cervical and lumbar spine fractures. This study aimed to create fracture maps of the traumatic thoracolumbar (TL) fracture vertebral body (T12-L2) through the use of CT mapping as a big data visualization method to reveal recurrent patterns and characteristics of traumatic TL fractures. MATERIAL AND METHODS A consecutive series of 174 fractured vertebrae (T12-L2) was used to create three-dimensional (3D) reconstruction images, which were superimposed and oriented to fit a model vertebral template by aligning specific bio-landmarks and reducing reconstructed fracture fragments. Fracture lines were found and traced to create a fracture map of the vertebral body. RESULTS Our study consisted of 165 patients with an average age of 47 years. A total of 174 fractured vertebrae were collected, consisting of 59 T12 vertebral fractures, 60 L1 vertebral fractures, and 55 L2 vertebral fractures. Two-dimensional (2D) maps, 3D maps, and heat maps showed that the fracture lines tended to be concentrated in the upper third and anterior third of the vertebral body, as well as being distributed in annular wedges along the anterior and lateral sides of the vertebral body. When compared with T12, the distribution of fracture lines in L1 and especially in L2 was more scattered and disorganized. CONCLUSIONS Fracture maps revealed recurrent patterns and characteristics of the traumatic TL fracture vertebral body, which improves understanding of TL fractures, as well as helping to increase opportunities for follow-up research and aid clinical decision-making.

Abstract PD1-08: Phase 1/1b study of novel oral selective estrogen receptor degrader (SERD) LSZ102 for estrogen receptor-positive (ER+) advanced breast cancer (ABC) with progression on endocrine therapy (ET)

Background: LSZ102 is an orally bioavailable SERD that inhibits ER gene transcription, induces receptor degradation, and blocks ER-dependent cell growth in preclinical models. This study is evaluating LSZ102 as a single agent and in combination with the CDK 4/6 inhibitor ribociclib (LEE011) or the PI3K inhibitor alpelisib (BYL719) in patients (pts) with ER+ ABC. The LSZ102 single agent data are presented below; combination data are not discussed.

Methods: In the dose-escalation phase evaluating single-agent LSZ102 (Arm A), pts (age ≥18 years; ECOG PS 0-1) with histologically confirmed ER+ ABC and progression on endocrine therapy (ET) received LSZ102. The starting dose was 200 mg once daily. The primary objective of Arm A was to characterize the safety and tolerability of LSZ102 and identify a recommended dose for expansion (RDE). Secondary objectives included preliminary antitumor activity and pharmacokinetics (PK).

Results: As of January 22, 2018, 57 pts were enrolled to Arm A (LSZ102 200 mg, n=4; 400 mg, n=6; 450 mg fasted, n=15; 450 mg with food, n=6; 600 mg, n=20; 900 mg, n=6). Median age was 60 years, 75% (n=43) of pts had an ECOG PS of 0, 56% (n=32) had received prior fulvestrant, and 58% (n=33) had received prior CDK4/6 inhibitors; median number of prior lines of therapy (all settings) was 6. At data cut-off, 48 pts had discontinued treatment, most (n=45, 94%) due to disease progression. Dose-limiting toxicities across treatment groups included diarrhea (2 pts in the 900-mg group), vomiting (1 pt in the 600-mg group), and AST and ALT elevation (1 pt in the 450-mg with food group). The most common treatment-related adverse events (AEs) in the treatment period were diarrhea (60%), nausea (56%), and vomiting (30%). In the treatment period, treatment-related grade 3 AEs (12%) were infrequent, and there were no such grade 4 events. Six pts (11%) required dose reduction due to AEs (nausea, vomiting or diarrhea); 4/6 of the dose reductions occurred at 900 mg. Preliminary PK assessment showed rapid absorption and dose-proportional increases in LSZ102 exposure; trough concentrations were above the predicted tumorostatic concentrations at doses of ≥400 mg. Based on PK results for the 450-mg fasted and fed cohorts, LSZ102 exposure does not appear to be affected by dosing with a regular meal. Evidence of ER modulation by immunohistochemistry was observed in paired baseline and on-treatment biopsies. 18F-fluoroestradiol positron emission tomography (FES-PET) analysis (n=6) demonstrated abrogation of FES-PET signal for pts in the 450-mg and 600-mg dose groups. Seventeen pts (29.8%) had a best response of stable disease, and 1 pt, who happened to be in the 600-mg group, achieved a partial response.

Conclusion: In heavily pretreated pts, LSZ102 was well tolerated, demonstrated antitumor activity, and achieved effective exposure levels based on PK and pharmacodynamics. Food intake did not appear to significantly alter the PK profile of LSZ102. Dose escalation for LSZ102 in combination with ribociclib or alpelisib is ongoing and will be reported in a future analysis. An update on the recommended single agent dose and schedule will be presented.

Citation Format: Jhaveri K, Curigliano G, Yap Y-S, Cresta S, Duhoux FP, Terret C, Takahashi S, Ulaner GA, Kundamal N, Baldoni D, Liao S, Crystal A, Juric D. Phase 1/1b study of novel oral selective estrogen receptor degrader (SERD) LSZ102 for estrogen receptor-positive (ER+) advanced breast cancer (ABC) with progression on endocrine therapy (ET) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD1-08.

Abstract OT1-03-01: Phase 1/1b study of novel oral selective estrogen receptor degrader (SERD) LSZ102 in combination with alpelisib (BYL719) in estrogen receptor-positive (ER+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC) with progression on endocrine therapy (ET)

Background: Although ET remains the basis of therapy for ER+, HER2– ABC, treatment resistance frequently occurs. Novel strategies to target the receptor and/or alternative pathways to overcome therapeutic resistance are under investigation. LSZ102 is a novel, orally bioavailable, nonsteroidal SERD. Preclinically, LSZ102 inhibits ER gene transcription, induces receptor degradation, blocks ER-dependent cell growth, and has synergistic activity with the phosphoinositide 3-kinase (PI3K)-alpha inhibitor alpelisib (BYL719). The present study is evaluating the safety and tolerability of LSZ102 plus alpelisib in patients with ER+, HER2– ABC with progression on ET.

Trial Design: This phase 1/1b, open-label study is enrolling ˜18-30 patients (men and women of any menopausal status) in Arm C of the dose-escalation part of the study, which investigates the combination of LSZ102 and alpelisib; additional study arms will investigate LSZ102 as a single agent or in combination with ribociclib. Enrollment in Arm C started after identification of a safe and tolerable single-agent dose for LSZ102. Alpelisib dosing began at 200 mg/day and will not be escalated beyond the maximum tolerated dose (MTD) determined in the alpelisib single-agent arm of study CBYL719X2101 (400 mg/day). Dose escalation of alpelisib in combination with LSZ102 is guided by BLRM and integrates Cycle 1 DLT rates, lower grade and later cycle AE, PK, PD and preliminary activity to identify a recommended dose for expansion (RDE). Patients will receive treatment until disease progression, unacceptable toxicity, or withdrawal of consent. For inclusion in the study, patients must have histologically confirmed ER+, HER2– ABC and disease progression after ET for ABC or recurrence on/within 12 months of completion of adjuvant ET. In the escalation part of the study, patients are eligible regardless of PIK3CA status. Premenopausal women must receive concomitant treatment with a gonadotropin-releasing hormone agonist. Eligible patients must have adequate bone marrow and organ function, Eastern Cooperative Oncology Group performance status of 0 or 1, and have completed and recovered from acute toxicities of radiotherapy and/or prior anticancer therapy. Exclusion criteria include symptomatic central nervous system metastases, clinically significant cardiac disease or impaired cardiac function (including a QT interval corrected for heart rate using Fridericia's formula [QTcF] >460 ms in women or >450 ms in men), uncontrolled diabetes mellitus type II (or type I), and prior treatment with a PI3K inhibitor. The primary objectives are characterization of safety and tolerability for the combination and identification of a recommended dose. Secondary objectives include characterization of pharmacokinetic properties and pharmacodynamic effects. Recruitment for Arm C is ongoing. NCT02734615

Citation Format: Curigliano G, Cresta S, Yap Y-S, Juric D, Duhoux FP, Terret C, Takahashi S, Layman RM, Kundamal N, Baldoni D, Liao S, Crystal A, Jhaveri K. Phase 1/1b study of novel oral selective estrogen receptor degrader (SERD) LSZ102 in combination with alpelisib (BYL719) in estrogen receptor-positive (ER+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC) with progression on endocrine therapy (ET) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-03-01.

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.

Three-dimensional visualization and pathologic characteristics of cartilage and subchondral bone changes in the lumbar facet joint of an ovariectomized mouse model

BACKGROUND CONTEXT

Low back pain (LBP) is more prevalent among postmenopausal women than men. Ovariectomy (OVX) is an established animal model that mimics the estrogen deficiency of postmenopausal women. Little is known about the three-dimensional (3D) morphologic properties of cartilage and subchondral bone changes in the lumbar facet joint (LFJ) of an OVX mouse model.

PURPOSE

The purpose of this study was to characterize the 3D morphologic change of cartilage and subchondral bone in the LFJ of an OVX mouse model.

STUDY DESIGN

Three-dimensional visualization and a histologic study on degenerative changes in cartilage and subchondral bone in the LFJ of an OVX mouse model were conducted.

MATERIALS AND METHODS

Ovariectomy is performed to mimic postmenopausal changes in adult female mice. We present an imaging tool for 3D visualization of the pathologic characteristics of cartilage and subchondral bone changes LFJ degradation using propagation-based phase-contrast computed tomography (PPCT). The samples were further dissected, fixed, and stained for histologic examination.

RESULTS

Propagation-based phase-contrast computed tomography imaging provides a 3D visualization of altered cartilage with a simultaneous high detail of the subchondral bone abnormalities in an OVX LFJ model. A quantitative analysis demonstrated that the cartilage volume, the surface area, and thickness were decreased in the OVX group compared with the control group (p<.05). Meanwhile, these decreases were accompanied by an obvious destruction of the subchondral bone surface and a loss of trabecular bone in the OVX group (p<.05). The delineation of the 3D pathologic changes in the PPCT imaging was confirmed by a histopathologic method with Safranin-O staining. Tartrate-resistant acid phosphatase staining revealed an increased number of osteoclasts in the subchondral bone of the OVX mice compared with that of the control group.

CONCLUSIONS

These results demonstrated that a mouse model of OVX-induced LFJ osteoarthritis (OA)-like changes was successfully established and showed a good resemblance to the human OA pathology. Propagation-based phase-contrast computed tomography has great potential to becomea powerful 3D imaging method to comprehensively characterize LFJ OA and to effectively monitor therapeutics. Moreover, degenerative LFJ possesses a severe morphologic change in the subchondral bone, may be the source of postmenopausal LBP, and has the potential to be a novel therapeutic target for LBP treatment.

Spinal Peripheral Primitive Neuroectodermal Tumors: A Radiological Analysis of Ten Cases

AIM

To summarize the imaging features of spinal peripheral primitive neuroectodermal tumor (spPNET) patients.

MATERIAL AND METHODS

The computed tomography and magnetic resonance imaging features of 10 spPNET patients, four men and six women, were retrospectively analyzed, and their clinicopathological data were reviewed.

RESULTS

The mean age of the patients was 24.7 years (range, 3-44 years). Ten spPNET lesions were found in the ten patients, including six extradural and four intradural extramedullary lesions. Radiologically, spPNET typically presented as heterogeneous isointense lesions with a heterogeneously enhanced pattern. A "vault wall-like growth" pattern, a linear enhancement pattern, and vertebral bone involvement tended to be found in the extradural lesions, whereas a ring enhancement pattern was found in the extramedullary intradural lesions. Positive Ki-67 expression might be related to necrosis, bone destruction, and hemorrhage.

CONCLUSION

A well-defined spinal mass showing isointensity/attenuation with heterogeneous enhancement accompanied by other imaging features may be suggestive of spPNET and should be added to the list of differential diagnosis.

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.

The 3D characteristics of post-traumatic syringomyelia in a rat model: a propagation-based synchrotron radiation microtomography study

Many published literature sources have described the histopathological characteristics of post-traumatic syringomyelia (PTS). However, three-dimensional (3D) visualization studies of PTS have been limited due to the lack of reliable 3D imaging techniques. In this study, the imaging efficiency of propagation-based synchrotron radiation microtomography (PB-SRµCT) was determined to detect the 3D morphology of the cavity and surrounding microvasculature network in a rat model of PTS. The rat model of PTS was established using the infinite horizon impactor to produce spinal cord injury (SCI), followed by a subarachnoid injection of kaolin to produce arachnoiditis. PB-SRµCT imaging and histological examination, as well as fluorescence staining, were conducted on the animals at the tenth week after SCI. The 3D morphology of the cystic cavity was vividly visualized using PB-SRµCT imaging. The quantitative parameters analyzed by PB-SRµCT, including the lesion and spared spinal cord tissue area, the minimum and maximum diameters in the cystic cavity, and cavity volume, were largely consistent with the results of the histological assessment. Moreover, the 3D morphology of the cavity and surrounding angioarchitecture could be simultaneously detected on the PB-SRµCT images. This study demonstrated that high-resolution PB-SRµCT could be used for the 3D visualization of trauma-induced spinal cord cavities and provides valuable quantitative data for cavity characterization. PB-SRµCT could be used as a reliable imaging technique and offers a novel platform for tracking cavity formation and morphological changes in an experimental animal model of PTS.

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).

WITHDRAWN: 3D visualization and pathological characteristics of cartilage and subchondral bone changes in the lumbar facet joint of an Ovariectomized mouse model

The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.spinee.2017.11.009. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

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.

Three Dimensional Quantification of Microarchitecture and Vessel Regeneration by Synchrotron Radiation Microcomputed Tomography in a Rat Model of Spinal Cord Injury

A full understanding of the mechanisms behind spinal cord injury (SCI) processes requires reliable three-dimensional (3D) imaging tools for a thorough analysis of changes in angiospatial architecture. We aimed to use synchrotron radiation μCT (SRμCT) to characterize 3D temporal-spatial changes in microvasculature post-SCI. Morphometrical measurements revealed a significant decrease in vascular volume fraction, vascular bifurcation density, vascular segment density, and vascular connectivity density 1 day post-injury, followed by a gradual increase at 3, 7, and 14 days. At 1 day post-injury, SRμCT revealed an increase in vascular tortuosity (VT), which reached a plateau after 7 days and decreased slightly during the healing process. In addition, SRμCT images showed that vessels were largely concentrated in the gray matter 1 day post-injury. The maximal endothelial cell proliferation rate was detected at 7 days post-injury. The 3D morphology of the cavity appears in the spinal cord at 28 days post-injury. We describe a methodology for 3D analysis of vascular repair in SCI and reveal that endogenous revascularization occurs during the healing process. The spinal cord microvasculature configuration undergoes 3D remodeling and modification during the post-injury repair process. Examination of these processes might contribute to a full understanding of the compensatory vascular mechanisms after injury and aid in the development of novel and effective treatment for SCI.