The greener the living environment, the better the health? Examining the effects of multiple green exposure metrics on physical activity and health among young students

The sedentary and less active lifestyle of modern college students has a significant impact on the physical and mental well-being of the college community. Campus Green Spaces (GSs) are crucial in promoting physical activity and improving students' health. However, previous research has focused on evaluating campuses as a whole, without considering the diverse spatial scenarios within the campus environment. Accordingly, this study focused on the young people's residential scenario in university and constructed a framework including a comprehensive set of objective and subjective GSs exposure metrics. A systematic, objective exposure assessment framework ranging from 2D (GSs areas), and 2.5D (GSs visibility) to 3D (GSs volume) was innovatively developed using spatial analysis, deep learning technology, and unmanned aerial vehicle (UAV) measurement technology. Subjective exposure metrics incorporated GSs visiting frequency, GSs visiting duration, and GSs perceived quality. Our cross-sectional study was based on 820 university students in Nanjing, China. Subjective measures of GSs exposure, physical activity, and health status were obtained through self-reported questionnaires. The Generalized Linear Model (GLM) was used to evaluate the associations between GSs exposure, physical activity, and perceived health. Physical activity and social cohesion were considered as mediators, and path analysis based on Structural Equation Modeling (SEM) was used to disentangle the mechanisms linking GSs exposure to the health status of college students. We found that (1) 2D indicator suggested significant associations with health in the 100m buffer, and the potential underlying mechanisms were: GSs area → Physical activity → Social cohesion → Physical health → Mental health; GSs area → Physical activity → Social cohesion → Mental health. (2) Subjective GSs exposure indicators were more relevant in illustrating exposure-response relationships than objective ones. This study can clarify the complex nexus and mechanisms between campus GSs, physical activity, and health, and provide a practical reference for health-oriented campus GSs planning.

Single-cell transcriptome sequencing reveals aberrantly activated inter-tumor cell signaling pathways in the development of clear cell renal cell carcinoma

BACKGROUND

Aberrant intracellular or intercellular signaling pathways are important mechanisms that contribute to the development and progression of cancer. However, the intercellular communication associated with the development of ccRCC is currently unknown. The purpose of this study was to examine the aberrant tumor cell-to-cell communication signals during the development of ccRCC.

METHODS

We conducted an analysis on the scRNA-seq data of 6 ccRCC and 6 normal kidney tissues. This analysis included sub clustering, CNV analysis, single-cell trajectory analysis, cell-cell communication analysis, and transcription factor analysis. Moreover, we performed validation tests on clinical samples using multiplex immunofluorescence.

RESULTS

This study identified eleven aberrantly activated intercellular signaling pathways in tumor clusters from ccRCC samples. Among these, two of the majors signaling molecules, MIF and SPP1, were mainly secreted by a subpopulation of cancer stem cells. This subpopulation demonstrated high expression levels of the cancer stem cell markers POU5F1 and CD44 (POU5F1hiCD44hiE.T), with the transcription factor POU5F1 regulating the expression of SPP1. Further research demonstrated that SPP1 binds to integrin receptors on the surface of target cells and promotes ccRCC development and progression by activating potential signaling mechanisms such as ILK and JAK/STAT.

CONCLUSION

Aberrantly activated tumor intercellular signaling pathways promote the development and progression of ccRCC. The cancer stem cell subpopulation (POU5F1hiCD44hiE.T) promotes malignant transformation and the development of a malignant phenotype by releasing aberrant signaling molecules and interacting with other tumor cells.

Molecular screening of Entamoeba spp. (E. histolytica, E. dispar, E. coli, and E. hartmanni) and Giardia intestinalis using PCR and sequencing

A wide range of intestinal protozoan parasites inhabit the human gut. To establish a more comprehensive molecular screening, we designed PCR-sequencing screening methods for Entamoeba spp., including commensal species, and Giardia intestinalis, and performed such methods using 174 stool samples collected from Kenyan children. The prevalences of the target species were as follows: E. histolytica (2/174, 1.1%), E. dispar (20/174, 11.5%), E. coli (107/174, 61.5%), E. hartmanni (77/174, 44.3%), and G. intestinalis (54/174, 31.0%). PCR amplicons specific to G. intestinalis was differentiated to assemblages A (8/174, 4.6%) and B (46/174, 26.4%). PCR specificity for Entamoeba spp. was quite high, except for some cross-reactions between E. hartmanni detection primers and G. intestinalis, although the false-positive amplicons were discernible by the band size. The 18S rRNA PCR primers that was designed by Monis et al. in 1999 for G. intestinalis, have specificity issue, therefore amplicon sequencing was essential not only to determine assemblage classifications but also to confirm the positive results by eliminating potential non-specific reactions. The detection sensitivity of both the Entamoeba universal PCR and the G. intestinalis PCR was more than 100 copies of the target loci, which is sufficient for detecting a single trophozoite or cyst of both species.

Partial versus radical nephrectomy for the treatment of pT3aN0M0 renal cell carcinoma: A propensity score analysis

BACKGROUND

The survival benefit of partial nephrectomy (PN) in pT3a RCC patients is controversial. Here we aimed to explore the potential benefit of PN for pT3aN0M0 renal cell carcinoma (RCC).

MATERIAL AND METHODS

Data of patients with pT3aN0M0 RCC who were diagnosed between 2010 and 2012 in the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database were retrospectively collected. Overall survival (OS) and cancer specific survival (CSS) were compared using a Cox proportional hazards model between PN and radical nephrectomy (RN) in pT3aN0M0 RCC. Propensity score (-adjusted, -stratified, -weighted, and -matched) analyses were performed to control for imbalances in individual risk factors.

RESULTS

A total of 1277 patients with pT3aN0M0 RCC were identified, of whom 200 patients were treated with PN and 1077 patients were RN. PN showed favorable OS and CSS in 0-4 cm pT3aN0M0 RCC (P < 0.05), and similar OS and CSS in 4-7 cm pT3aN0M0 RCC, compared with RN using un-adjusted analyses. The Propensity score analyses further demonstrated the survival benefit of PN compared with the RN in 0-4 cm pT3aN0M0 RCC (P < 0.05).

CONCLUSIONS

In this retrospective study, PN was associated with improved survival compared with RN in 0-4 cm pT3aN0M0 RCC. Moreover, survival was comparable between PN and RN in 4-7 cm pT3aN0M0 RCC. These data provided evidence that PN could be an alternative choice for T3aN0M0 RCC less than 7 cm. Particularly, patients with 0-4 cm pT3aN0M0 RCC might benefit from PN.

[Bioinformatics analysis and prokaryotic expression of Strongyloides stercoralis serine protease inhibitor 1]

OBJECTIVE

To predict the structure and antigenic epitope of the Strongyloides stercoralis serine protease inhibitor 1 (Ss-SRPN-1) protein using bioinformatics tools, and to construct prokaryotic expression plasmids for expression of recombinant Ss-SRPN-1 protein, so as to provide the basis for unraveling the function of the Ss-SRPN-1 protein.

METHODS

The amino acid sequence of the Ss-SRPN-1 protein was downloaded from the NCBI database, and the physicochemical properties, structure and antigenic epitopes of the Ss-SRPN-1 protein were predicted using bioinformatics tools, including ExPASy, SWISS-MODEL and Protean. Primers were designed according to the nucleotide sequences of Ss-SRPN-1, and the Ss-SRPN-1 gene was amplified, cloned and sequenced with genomic DNA extracted from the infective third-stage larvae of S. stercoralis as a template. The Ss-SRPN-1 protein sequence was cloned into the pET28a (+) expression vector and transformed into Escherichia coli BL21 (DE) cells for induction of the recombinant Ss-SRPN-1 protein expression. The recombinant Ss-SRPN-1 protein was then purified and identified using Western blotting and mass spectrometry.

RESULTS

Bioinformatics analysis showed that the Ss-SRPN-1 protein, which was composed of 372 amino acids and had a molecular formula of C₁₉₄₈H₃₀₄₆N₄₈₈O₅₇₅S₁₆, was a stable hydrophilic protein, and the subcellular localization of the protein was predicted to be extracellular. The Ss-SRPN-1 protein was predicted to contain 11 dominant B-cell antigenic epitopes and 20 T-cell antigenic epitopes. The Ss-SRPN-1 gene with a length of 1 119 bp was successfully amplified, and the recombinant plasmid pET28a (+)/Ss-SRPN-1 was constructed and transformed into E. coli BL21(DE) cells. The expressed recombinant Ss-SRPN-1 protein had a molecular weight of approximately 43 kDa, and was characterized as a Ss-SRPN-1 protein.

CONCLUSIONS

The recombinant Ss-SRPN-1 protein has been expressed successfully, and this recombinant protein may be a potential vaccine candidate against strongyloidiasis.

[Expression of CD47 and its ligands in pregnant mice infected with Toxoplasma gondii during pregnancy]

OBJECTIVE

To investigate the dynamic expression of cluster of differentiation 47 (CD47) and its ligands signaling regulatory protein α (SIRPα) and thrombospondin-1 (TSP-1) in mice infected with Toxoplasma gondii in the second and third trimesters.

METHODS

C57BL/6J mice (6 to 8 weeks old) were used for modeling T. gondii infection in the first trimester, and the pregnant mice were randomly divided into the normal control and infection groups, of 10 mice in each group. Pregnant mice in the infection group were intraperitoneally injected with 150 T. gondii tachyzoites on gestational day (Gd) 6.5, while pregnant mice in the normal control group were intraperitoneally injected with the same volume of physiological saline at the same time. The uterine and placental specimens were collected from all pregnant mice on Gd12.5 and Gd18.5, and the pregnant outcomes were recorded. The pathological damages of mouse uterine and placental specimens were observed using hematoxylin-eosin (HE) staining on Gd12.5 and Gd18.5. The relative expression of CD47, SIRPα, TSP-1, surface antigen 1 (SAG1), interferon-γ (IFN-γ), interleukin-2 (IL-2), IL-4 and IL-13 mRNA was quantified in mouse uterine and placental specimens using real-time fluorescence quantitative PCR (qPCR) assay, and the CD47, SIRPα, TSP-1 expression was determined in mouse uterine and placental specimens using immunohistochemical staining.

RESULTS

As compared with those in the normal control group, the pregnant mice in the infection group showed back arching, bristling, trembling and listlessness during pregnancy, and several mice presented virginal bleeding and abortion. Pathological examinations showed inflammatory cell infiltration, congestion and necrosis in uterine and placental specimens of pregnant mice in the infection group, a higher abortion rate of pregnant mice was seen in the infection group than in the normal control group on Gd12.5 (χ² = 20.405, P < 0.001) and Gd18.5 (χ² = 28.644, P < 0.001). qPCR assay showed significant differences in the expression of CD47, SIRPα, TSP-1, SAG1, INF-γ, IL-2, IL-4 and IL-13 genes in mouse placental specimens between the normal control and infection groups on Gd12.5 and Gd18.5 [F' (F) = 37.511, 29.337, 97.343, 53.755, 67.188, 21.145, 8.658 and 13.930, all P values < 0.001]. Higher CD47, SIRPα and TSP-1 gene expression was quantified in mouse placental specimens in the infection group than in the normal control group on Gd12.5 (all P values < 0.01), and lower CD47, SIRPα and TSP-1 gene expression was quantified in the infection group than in the normal control group on Gd18.5 (all P values < 0.001), while higher SAG1 gene expression was detected in placental specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (both P values < 0.01). In addition, higher INF-γ and IL-2 expression and lower IL-4 and IL-13 expression was detected in mouse placental specimens in the infection group than in the normal control group on Gd12.5 and Gd18.5 (all P values < 0.001), and there were significant differences in the CD47, SIRPα, TSP-1, SAG1, INF-γ, IL-2, IL-4 and IL-13 gene expression in uterine specimens of pregnant mice between the normal control and infection groups on Gd12.5 and Gd18.5 [H(F' and F) = 14.951, 25.977, 18.711, 48.595, 39.318, 14.248 and 15.468, all P values < 0.01], and higher CD47 and TSP-1 expression was detected in mouse uterine specimens in the infection group than in the control group on Gd12.5 and Gd18.5 (all P values < 0.01); however, no significant difference was found in the SIRPα expression (P > 0.05). Higher SAG1 expression was detected in uterine specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (both P values < 0.01), and higher INF-γ and IL-2 gene expression and lower IL-4 and IL-13 gene expression was found in the placental specimens of pregnant mice in the infection group than in the normal control group on Gd12.5 and Gd18.5 (all P values < 0.001). Spearman correlation analysis showed that the CD47 gene expression correlated positively with IFN-γ (r_s = 0.735, P < 0.05) and IL-2 (r_s = 0.655, P < 0.05) and negatively with IL-4 (r_s = -0.689, P < 0.05) and IL-13 expression (r_s = -0.795, P < 0.05) in the placental specimens of pregnant mice in the infection group on Gd12.5, and the CD47 gene expression correlated negatively with IFN-γ (r_s = -0.745, P < 0.05) and IL-2 expression (r_s = -0.816, P < 0.05) and positively with IL-4 (r_s = 0.704, P < 0.05) and IL-13 (r_s = 0.802, P < 0.05) in the placental specimens of pregnant mice in the infection group on Gd18.5. Immunohistochemical staining showed mild CD47, SIRPα and TSP-1 expression in uterine and placental specimens of pregnant mice in the normal control group on Gd12.5 and Gd18.5, strong CD47, SIRPα and TSP-1 expression in the placental specimens of pregnant mice in the infection group on Gd12.5 and strong CD47 and TSP-1 expression in the uterine specimens of pregnant mice in the infection group on Gd12.5.

CONCLUSIONS

T. gondii infection in the first trimester may cause abnormal expression of CD47 and its ligands SIRPα and TSP-1 in the maternal-fetal interface of pregnant mice in the second and third trimesters, which may be associated with the immune escape of T. gondii at the maternal-fetal interface.

Abstract 5690: The landscape of homologous recombination repair gene mutations and prognosis in Chinese patients with clear cell renal cell carcinoma

Background: Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancer with poor prognosis. Mutations in homologous recombination repair (HRR) genes are associated with human tumorigenesis and response to DNA-damage-inducing therapeutics, such as platinum agents and PARP inhibitors. A better understanding of the genomic features of HRR pathway genes and its correlations with prognosis will facilitate precise personalized treatment selection.

Methods: Tumor tissues and matched blood were collected from 269 ccRCC patients at the 3rd Affilated Teaching Hospital of Xinjiang Medical University(Affiliated Tumor Hospital) from 2011 to 2017. A panel targeting 450 cancer-related gene test was performed at OrigiMed (Shanghai, China). Using targeted capture genomic sequencing, we assessed patients for germline and somatic mutations in 23 HRR related genes. Survival analysis was performed using a Cox proportional hazards model and the p-value was determined with a log-rank test.

Results: In total, 269 ccRCC patients, including 95 females and 174 males with a median age of 55 (range 21-87 years old), were recruited. Fifty patients developed distant metastases. The most frequently mutated genes were VHL (83%) and PBRM1 (38%). The median tumor mutational burden (TMB) of this cohort was 4 muts/Mb (0-43.9 muts/Mb), and 4.1% (11/269) of patients displayed high TMB (defined as ≥ 10 muts/Mb). HRR pathway gene mutations were detected in 90/269 patients (33.46%). The most frequently altered genes were BAP1(13.4%), ARID1A (5.2%), BRCA1 (3.72%), ATM (3.35%), and BRCA2 (1.86%). Truncation (23.05%) was the most common mutation type. 4.46% (12/269) of patients carried HRR-related germline mutations, and the most frequently mutated germline genes were RAD51C/D (33.33%,4/9) and BRCA (16.67%, 2/9). Patients with HRR pathway gene mutations were found to have a significantly higher TMB (median, 4.45 vs. 4 muts/Mb, p &lt; 0. 05). We additionally identified that mutations in HRR pathways were significantly associated with decreased relapse-free survival (RFS)( p &lt; 0.05). The 3-year RFS rate of the HRR-mutated group was significantly lower than the negative group (78.8% vs.90.6%, p&lt;0.01).

Conclusion: HRR gene alterations, associated with increased recurrence, occurred at a high frequency of 33.46% in Chinese ccRCC patients. Further studies regarding to therapeutic agents targeting the HRR pathway in this population should be considered in the future.

Citation Format: Peng Chen, Yuan Zhang, Xing Bi, Yue Niu, Fuerhaiti Shayiti, Shuai Yuan, Ting Pan, Yan Wang. The landscape of homologous recombination repair gene mutations and prognosis in Chinese patients with clear cell renal cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5690.

Temporal-spatial variation and the affecting factors of protected areas in Guizhou, China

The establishment of protected areas is the bottom line of ecological security for promoting the construction of ecological civilization and supporting economic and social development, which is an important strategy to realize sustainable development and maintain ecological security. In order to reveal the large spatial process of protected areas and its influencing factors, we used the methods of nearest neighbor index, kernel density, and standard deviational ellipse to analyze the temporal-spatial variation characteristics of the protected areas in Guizhou Province from 2002 to 2017, as well as the influencing factors combined with geo-detectors. The results showed that, during the study period, the number, area, and types of protected areas in Guizhou Province showed a diversified and rapid development, forming a protected area system with nature reserves, forest parks and scenic spots as the main body and wetland parks, geoparks and natural heritage sites as the supplement. The spatial cohesion of protected areas was strengthened, the scope of spatial distribution was expanding, and the speed of spatial movement was declining, forming a spatial pattern dominated by the northeast-southwest direction and gradually stable. The coalescence process in protected areas was strongly influenced by topography and vegetation distribution. The protected areas tended to cluster in gentle terrain around rivers and mountains and in areas of concentrated vegetation. The spatial differentiation of protected areas was jointly affected by multiple factors at different levels. The explanatory power of different factors to the spatial differentiation of protected areas was different. Among them, the normalized difference vegetation index, areas of forest and highway mileage were the common main factors affecting the spatial differentiation of the number and area of protected areas, and the explanatory power of different factors was significantly consolidated after interaction, characterized as nonlinear or bi-factor enhancement.

Cerebral Venous Thrombosis: MR Black-Blood Thrombus Imaging with Enhanced Blood Signal Suppression

BACKGROUND AND PURPOSE

The residual blood flow artifact is a critical confounder for MR black-blood thrombus imaging of cerebral venous sinus thrombosis. This study aimed to conduct a validation of a new MR black-blood thrombus imaging technique with enhanced blood signal suppression.

MATERIALS AND METHODS

Twenty-six participants (13 volunteers and 13 patients) underwent conventional imaging methods followed by 2 randomized black-blood thrombus imaging scans, with a preoptimized delay alternating with nutation for tailored excitation (DANTE) preparation switched on and off, respectively. The signal intensity of residual blood, thrombus, brain parenchyma, normal lumen, and noise on black-blood thrombus images were measured. The thrombus volume, SNR of residual blood, and contrast-to-noise ratio for residual blood versus normal lumen, thrombus versus residual blood, and brain parenchyma versus normal lumen were compared between the 2 black-blood thrombus imaging techniques. Segmental diagnosis of venous sinus thrombosis was evaluated for each black-blood thrombus imaging technique using a combination of conventional imaging techniques as a reference.

RESULTS

In the volunteer group, the SNR of residual blood (11.3 ± 2.9 versus 54.0 ± 23.4, P < .001) and residual blood-to-normal lumen contrast-to-noise ratio (7.5 ± 3.4 versus 49.2 ± 23.3, P < .001) were significantly reduced using the DANTE preparation. In the patient group, the SNR of residual blood (16.4 ± 8.0 versus 75.0 ± 35.1, P = .002) and residual blood-to-normal lumen contrast-to-noise ratio (12.4 ± 7.8 versus 68.8 ± 35.4, P = .002) were also significantly lower on DANTE-prepared black-blood thrombus imaging. The new black-blood thrombus imaging technique provided higher thrombus-to-residual blood contrast-to-noise ratio, significantly lower thrombus volume, and substantially improved diagnostic specificity and agreement with conventional imaging methods.

CONCLUSIONS

DANTE-prepared black-blood thrombus imaging is a reliable MR imaging technique for diagnosing cerebral venous sinus thrombosis.

[The protective effect of pigment epithelial-derived factor modified human umbilical cord mesenchymal stem cells on rats with diabetic retinopathy]

Objective: To investigate the effect of pigment epithelial-derived factor (PEDF) gene-modified human umbilical cord mesenchymal stem cells (MSC) on rats with diabetic retinopathy (DR). Methods: Experimental study. Human umbilical cord MSC were transfected by lentivirus packaging PEDF-MSC-green fluorescent protein (GFP) and GFP-MSC plasmid vectors, and the expression of PEDF and vascular endothelial growth factor (VEGF) was measured in the cell culture medium. Fifty adult male Sprague-Dawley rats were randomly divided into five groups: normal control group (group A), DR control group (group B), phosphate-buffered saline (PBS) treated group (group C), GFP-MSC treated group (group D) and PEDF-MSC-GFP treated group (group E), with 10 rats in each group. Streptozotocin was intraperitoneally injected to make early DR models. After four-month intervention, groups D and E were given intravitreal injection of GFP-MSC and PEDF-MSC-GFP; group C was given intravitreal injection of phosphate-buffered saline; groups A and B did not receive special treatment. The changes of retina in different groups were detected by hematoxylin and eosin staining, and the thickness of inner plexiform layer, inner nuclear layer and outer nuclear layer was measured by computer-based image analytical system. Immunohistochemistry was applied to observe PEDF and VEGF. Real-time quantitative polymerase chain reaction was used to detect the expression of PEDF and VEGF mRNA. Results: The expression of CD105, CD73 and CD90 was positive, while the expression of CD34, CD45, CD11b, CD19 and HLA-DR was negative. ELISA results showed that after transfection PEDF protein expression in the supernatant of PEDF-MSC (84.09±7.07) μg/L was higher than the control group (9.03±0.14) μg/L (P<0.05). At 2 weeks after intravitreal injection, green fluorescence was observed in the rat vitreous of groups D and E under a fluorescence microscope; no obvious green fluorescence was found in the retina. After 2 months of intravitreal injection, the thickness of inner plexiform layer in group E was significantly decreased; the thickness of inner nuclear layer and outer nuclear layer was higher (P<0.05). Immunohistochemical staining showed that 2 months after intravitreal treatment, the average optical density values of PEDF were improved, but the average optical density values of VEGF were decreased in group E (P<0.05). Real-time polymerase chain reaction showed that 2 months after treatment, the expression level of PEDF mRNA in group E was improved, but the expression level of VEGF mRNA was decreased (P<0.05). Conclusions: Intravitreal injection of PEDF-MSC could up-regulate the expression of PEDF and down-regulate the expression of VEGF in diabetic rats and may represent a novel candidate resource for cell therapy of DR nerve damage. (Chin J Ophthalmol, 2017, 53, 540-547).

A combination of the modified Stoppa approach and the iliac fossa approach in treating compound acetabular fractures by using an anterior ilioischial plate

Most compound acetabular fractures involving both the anterior and posterior columns are caused by high-energy injuries. Patients with compound acetabular fractures are often in critical or poor condition and cannot tolerate major surgery. This study aims to investigate the effectiveness of an ilioischial plate in treating compound acetabular fractures. A consecutive series of 40 patients with complex acetabular fractures were surgically treated and retrospectively reviewed. A modified Stoppa approach in combination with an iliac fossa approach was used. In all of the cases, the anterior column was stabilized with reconstruction plates for the iliac wing and along the iliopectineal line to the pubis. The posterior column was fixed either with the newly developed ilioischial plate running from the ilium to the ischial ramus or with standard fixation techniques. These included either conventional posterior column screws or quadrilateral plate fixation. Patients were divided into an experimental group (ilioischial plate for posterior column fixation) and a control group (standard fixation techniques). In both groups, we found that 90% of all reductions were good to excellent. According to the modified Merle Aubigne and Postel scoring system, the percentage of good to excellent was 85% in the experimental group as compared to 80% in the control group. Compared with the control group, physical function (PF), role physical (RP) and social function (SF) were significantly better in the experimental group (P<0.05). Fracture healing was achieved in all patients. By using the modified Stoppa approach combined with the iliac fossa approach, the ilioischial plate can be directly fixed to the posterior column and the ilium to stabilize the posterior column in patients with complex acetabular fractures.

Clinical, neuroimaging and prognostic study of 127 cases with infarction of the corpus callosum

Background and purpose

The aim of this study was to retrospectively investigate clinical and neuroimaging characteristics in the largest sample size of patients with corpus callosum infarction to date and then to follow up these patients for 1 year to clarify the prognosis of this rare stroke entity.

Methods

A total of 127 patients with acute callosal infarction out of 5584 acute ischaemic stroke patients were included in this study. The recruited patients were divided into a pure callosal infarction group and a complex callosal infarction group (coupled with other infarct locations simultaneously), and clinical and neuroimaging features were analyzed. Some of the patients were followed up for 1 year to evaluate recurrence rate and mortality.

Results

The incidence of acute callosal infarction was 2.3%. Most patients presented with advanced neurological dysfunction with or without mild to moderate motor or sensory disorders on admission. The negative rate of computed tomography scan was still 76.4% even at >24 h after onset. Large‐artery atherosclerosis was the most common etiological type. Compared with complex callosal infarction, the pure callosal infarction group had more mental disorders (P = 0.030). Compared with common basal ganglia infarction, the pure callosal infarction group had better short‐term recovery (P = 0.016) but higher 1‐year mortality (P = 0.037). Age and mental disorders were independent risk factors for death in callosal infarction.

Conclusions

Callosal infarction is a white matter stroke that occurs with low incidence. Elderly patients with vascular risk factors showed sudden mental or cognitive disorders and callosal infarction could not be excluded. More attention should be paid to the early diagnosis and secondary prevention of callosal infarction because of its poor long‐term outcome.

[Reliability and validity of the Chinese version on Comprehensive Scores for Financial Toxicity based on the patient-reported outcome measures]

Objective: To evaluate the reliability and validity of the Chinese version on comprehensive scores for financial toxicity (COST), based on the patient-reported outcome measures. Methods: A total of 118 cancer patients were face-to-face interviewed by well-trained investigators. Cronbach's α and Pearson correlation coefficient were used to evaluate reliability. Content validity index (CVI) and exploratory factor analysis (EFA) were used to evaluate the content validity and construct validity, respectively. Results: The Cronbach's α coefficient appeared as 0.889 for the whole questionnaire, with the results of test-retest were between 0.77 and 0.98. Scale-content validity index (S-CVI) appeared as 0.82, with item-content validity index (I-CVI) between 0.83 and 1.00. Two components were extracted from the Exploratory factor analysis, with cumulative rate as 68.04% and loading>0.60 on every item. Conclusion: The Chinese version of COST scale showed high reliability and good validity, thus can be applied to assess the financial situation in cancer patients.

[Correlation of 41 loci of single nucleotide polymorphisms with testicular germ cell tumor]

OBJECTIVE

To identify genetic susceptibility genes and the loci of their single nucleotide polymorphisms (SNPs) in patients with testicular germ cell tumor (TGCT) and provide some new ideas for the prediction, diagnosis and treatment of TGCT.

METHODS

We identified 41 SNP loci of TGCT-related genetic susceptibility genes from the literature published abroad. Using the iMLDRTM genotyping technique, we examined the SNP loci of the genetic susceptibility genes in the blood samples from 76 TGCT patients (aged 16－68 years) and 148 healthy men (aged 22－61 years) in China and analyzed their correlation with TGCT.

RESULTS

In China, TGCT was found to be correlated with the SNP loci rs2978381, rs10146204, rs12435857 and rs1256063 of the ESR2 gene, rs9397080 of the ESR1 gene, rs11202586 of the PTEN gene, rs2606345 and rs4646903 of the CYP1A1 gene, and rs1456432 of the CYP19A1 gene.

CONCLUSIONS

The results of our study indicated some difference in the positive SNP loci of the TGCT patients between Chinese and foreign cohorts as well as in different groups in China.

CCAAT enhancer binding protein β promotes tumor growth and inhibits apoptosis in prostate cancer by methylating estrogen receptor β

The CCAAT enhancer binding protein β (C/EBPβ) is overexpressed at late stages in carcinogenesis of prostate cancer (PCa), suggesting that it could potentially contribute to progression of PCa. Estrogen receptor beta (ERβ) is a tumor suppressor gene in PCa. However, whether C/EBPβ could regulate ERβ by promoter methylation is still poorly understood.In this study, expression levels of C/EBPβ and ERβ in two PC lines (LNCap and PC-3), prostatic epithelial cell line (RWPE-1), forty-eight paired non-cancerous and cancerous peripheral blood samples were examined via qRT-PCR, western blotting and methylation-specific PCR. In addition, PCa cell line was infected with pCDH-C/EBPβ and pLKO.1-C/EBPβ and expression levels of C/EBPβ, ERβ and DNA methyltransferases were detected. Finally, the role of C/EBPβ in proliferation and apoptosis of PCa cell lines was examined by MTT and flow cytometer assay. Our results show a higher frequency of promoter methylation of ERβ levels in blood samples from PCa patients (16 of 48 cases) compared with that from healthy controls (3 of 48). Besides, elevated expression levels of C/EBPβ were found in PCa patients and two PCa lines (LNCap and PC-3) compared to non-cancerous cases or prostatic epithelial cell line (RWPE-1), while opposite expression levels of ERβ were found. Overexpression of C/EBPβ could regulate ERβ expression, DNA methyltransferases expression, cell proliferation and apoptosis. Our results support the conclusion that C/EBPβ down-regulated ERβ expression through increasing its promoter methylation, and then regulated proliferation and apoptosis in PCa.

[The protective effect of human umbilical cord mesenchymal stem cells-induced neural stem cells in the vitreous on the blood-retinal barrier in diabetic rats]

Objective: To investigate the effect of intravitreal injection of neural stem cells (NSC) induced from human umbilical cord mesenchymal stem cells, and to provide a theoretical basis for the clinical treatment of blood-retinal barrier damage due to diabetic retinopathy (DR). Methods: Experimental study. Sixty male Sprague-Dawley rats were randomly divided into control group, DR group and NSC group. Diabetic rats were induced by injection of streptozotocin, and the control rats were injected with an equal volume of solvent. Three months after the establishment of diabetic models, the NSC group was injected with 2 μl of NSC in the right vitreous, and the DR group was injected with 2 μl of phosphate-buffered saline. One month later, all the rats were sacrificed. The retinal vessels and leakage were examined with flat-mounted retinas. Vascular permeability was quantified by analyzing albumin leakage using the Evans blue (EB) method. Retina was examined by hematoxylin and eosin staining. Results: Retinal blood vessels of the control rats were normal, with no EB leakage outside the vessels. The background fluorescence was enhanced and focal leakage and focal dilated vessels were detected in the DR group. In the NSC group, background fluorescence was enhanced slightly and EB leakage area decreased significantly compared with the DR group. The average EB in control group, DR group and NSC group were (9.91±1.53), (24.67±2.26) and (12.85±2.58)μg/g, The EB leakage in the NSC group decreased significantly compared with the DR group (q=9.748, P<0.05). Pathological hematoxylin and eosin staining showed that the retinal layer structure was normal and clear in the control group, the retina was thin, the cell arrangement was in disorder and the nucleus was swelling in the DR group, the status of the NSC group was between the other two groups. Conclusions: Transferring human umbilical cord mesenchymal stem cells-induced NSC in vitro to diabetic rat models by intravitreal injection could reduce leakage of blood vessels and attenuate blood-retinal barrier breakdown induced by diabetes. (Chin J Ophthalmol, 2017, 53: 53-58).

Clinical comparison of patients with benign urachal masses versus urachal carcinomas

The clinical features of 17 patients with benign urachal masses and 30 patients with urachal carcinoma treated at Sun Yat-sen University Cancer Center were analyzed retrospectively. Univariate analysis indicated that seven parameters differed significantly between the two groups. Binary logistic regression analyses showed that the rate of gross hematuria was significantly higher (P = 0.042, Exp[B] = 7.889) and the rate of fatty infiltration of the Retzius space was significantly lower (P = 0.006, Exp[B] = 0.028) in patients with urachal carcinoma than in those with benign urachal masses. Gross hematuria and fatty infiltration of the Retzius space may be indications of malignant and benign urachal masses, respectively.

Bilateral pelvic lymph node dissection for Chinese patients with penile cancer: a multicenter collaboration study

BACKGROUND

Current guidelines recommend pelvic lymphadenectomy (PLND) for patients with pelvic lymph node metastasis and special state. However, these data and recommendations do not distinguish the role of PLND in different patient groups and confirm the final benefits. The aim of this study was to confirm the efficacy of pelvic lymphadenectomy (PLND) for the different groups of patients.

METHODS

Data obtained from 7 centers were retrospectively analyzed. Of the patients, 190 pN2-3 penile carcinoma patients confirmed by bilateral inguinal lymph node excision were included in this study. Sixty-nine and 121 of these patients did and did not undergo bilateral PLND, respectively. The baseline differences from the patients were matched by propensity score analysis.

RESULTS

In this study, the Kaplan-Meier estimated disease-specific survival (DSS) was not significantly different between the PLND and no-PLND groups (P = 0.796). According to the propensity score matching for T stage, N stage, grade, adjuvant therapies, and lymph node stage (number of inguinal lymph node metastasis and extranodal extension), 48 patients were selected for each group. Among the pN2 patients, the PLND group showed higher DSS rates than the no-surgery group (P = 0.030). However, even after matching, survival did not differ between the PLND and no-PLND patients among all patients (P = 0.609) and pN3 patients (P = 0.417) with comparable DSS.

CONCLUSION

Bilateral PLND may improve survival in pN2 patients. Men with pN3 may not benefit from bilateral PLND.

[The normative values of vestibular evoked myogenic potentialin different age-groups]

Objective:To obtain the normative values of vestibular evoked myogenic potential(VEMP),i.e.the threshold,latency,latency-interval,amplitude of healthy population in Tianjin medical university General hospital.These values will help clinical diagnosis.Method:Seventy-five healthy individuals (39 males and 36 females,age from 21 to 70 years)were enrolled in this study.They were divided into 3 groups according to age:group 1(21-30 years),group 2(>30-50 years),group 3(>50-70 years).oVEMP and cVEMP were performed and the normative values were obtained.SPSS 19.0 was used to analyze the data.Result:The response rate was 77.3% and 85.3% of oVEMP and cVEMP respectively in all subjects.The values of oVEMP:in group 1 response rate was 100%,amplitude was(8.29±1.25)μV and threshold value was(83.65±4.10) dBnHL.In group 2 response rate was 85.4%,amplitude was(6.32±1.21)μV and threshold value was(89.24±4.18) dBnHL.In group 3 response rate was 46%,amplitude was(4.26±1.20) μV,threshold value was(95.13±4.21) dBnHL.The values of cVEMP: in group 1 response rate was 100%,amplitude was(108.87±19.10)μV and threshold value was(84.54±4.35) dBnHL.In group 2 response rate was 83.3%,amplitude was(84.10±20.02)μV and threshold value was (90.33±4.29)dBnHL.In group 3 response rate was 72.0%,amplitude was(64.18±19.22)μV and threshold value was (95.19±4.30)dBnHL.The statistical analysis show significant difference in oVEMP/cVEMP response rate,threshold and amplitude among different age-groups(P<0.05).No significant difference was found in N1,P1 latency and latency-interval among different age-groups(P>0.05).Conclusion:The normative values of VEMP of healthy population in Tianjin medical university General hospital were obtained in this research.These VEMP data were used for the diagnosis of related diseases.

Association of FokⅠ polymorphism in vitamin D receptor gene with risk of gastric cancer in a Xinjiang Uygur population

AIM: To investigate whether the FokⅠ polymorphism in the vitamin D receptor gene is associated with risk of gastric cancer.

METHODS: A total of 147 Uygur patients with gastric cancer (group A) were randomly selected from March 2013 to May 2015 in the Tumor Hospital of Xinjiang Medical University, and 151 healthy Uygur people (group B) were used as controls. The FokⅠ polymorphism in the vitamin D receptor gene was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, followed by an intergroup comparison. By PCR-RFLP test, all the patients with gastric cancer were divided into an FF group (a) and an Ff + ff group (b) according to whether the patient carried the allele f. The D-dimer level of the two groups was then compared.

RESULTS: The frequency of the allele f in gastric cancer patients was higher than that in the control group (57.8% vs 47.4%, P < 0.05). Multivariate logistic regression analysis showed that the study subjects carrying the allele f (Ff + ff) had a higher gastric cancer risk than those without (FF) (OR = 2.85). The D-dimer level in the Ff + ff group was significantly elevated compared with the FF group (2.79 ± 1.21 vs 1.09 ± 0.65, P < 0.05). As the differentiation of gastric cancer worsened, the percentage of patients only carrying the allele F (FF) decreased gradually (P < 0.05).

CONCLUSION: The FokⅠ polymorphism in the vitamin D receptor gene is associated with susceptibility to gastric cancer. The allele f may be one of the risk factors for gastric cancer, whereas the allele F may be a protective factor. Moreover, the levels of D-dimer in patients with gastric cancer carrying the allele f (Ff, ff) are significantly higher than those only carrying the allele F (FF), suggesting that the allele f may be a regulator of D-dimer and thus influences the onset or prognosis of gastric cancer in Uygur people.

Evaluation of Vitronectin Expression in Prostate Cancer and the Clinical Significance of the Association of Vitronectin Expression with Prostate Specific Antigen in Detecting Prostate Cancer

PURPOSE

To detect the expression of vitronectin (VTN) in the tissues and blood serum of prostate cancer (PCa) patients, and evaluate its clinical significance and to evaluate the significance of the combined assay of VTN and prostate specific antigens (PSA) in PCa diagnosis.

MATERIALS AND METHODS

To detect the expression of VTN as a potential marker for PCa diagnosis and prognosis, immunohistochemistry was performed on the tissues of 32 patients with metastatic PCa (PCaM), 34 patients with PCa without metastasis (PCa), and 41 patients with benign prostatic hyperplasia (BPH). The sera were then subjected to Western blot analysis. All cases were subsequently examined to determine the concentrations of PSA and VTN in the sera. The collected data were collated and analyzed.

RESULTS

The positive expression rates of VTN in the tissues of the BPH and PCa groups (including PCa and PCaM groups) were 75.61% and 45.45%, respectively (P = .005). VTN was more highly expressed in the sera of the BPH patients (0.83 &plusmn; 0.07) than in the sera of the PCa patients (0.65 &plusmn; 0.06) (P &lt; .05). It was also more highly expressed in the sera of the PCa patients than in the sera of the PCaM patients (0.35 &plusmn; 0.08) (P &lt; .05). In the diagnosis of BPH and PCa, the Youden indexes of PSA detection, VTN detection, and combined detection were 0.2620, 0.3468, and 0.5635; the kappa values were 0.338, 0.304, and 0.448, respectively, and the areas under the receiver operating characteristic curve were 0.625, 0.673, and 0.703 (P &lt; .05), respectively.

CONCLUSION

VTN levels in sera may be used as a potential marker of PCa for the diagnosis and assessment of disease progression and metastasis. The combined detection of VTN and PSA in sera can be clinically applied in PCa diagnosis.&nbsp.

Effect and clinical significance of fast-track surgery combined with laparoscopic radical gastrectomy on the plasma level of vascular endothelial growth factor in gastric antrum cancer

This study discusses the effect and clinical significance of fast-track surgery (FTS) combined with laparoscopic radical surgery on the plasma level of vascular endothelial growth factor (VEGF) in locally advanced gastric antrum cancer. Plasma VEGF levels were detected in 63 cases of locally advanced gastric antrum cancer by using double-antibody sandwich Avidinbiotincomplex-ELISA before and after operation. The pure laparoscopic surgery group (group A) comprised 30 cases, and the combined FTS group (group B) consisted of 33 cases. Results of the two groups were obtained at similar time points and then compared. The VEGF levels were not significantly different between the two groups on the first day before the operation and on the first day, third day, and sixth month after the operation (P > 0.05). However, the differences were significant on the seventh day and first month after the operation (P < 0.05). The postoperative eating time, anal exhaust time, and hospital stay of the patients were statistically significantly different between the two groups (P < 0.05). Nevertheless, no significant differences were detected in terms of wound healing time and complications (P > 0.05). The 3-year survival rate significantly differed between the two groups (P < 0.05). FTS combined with laparoscopic surgery can decrease the postoperative VEGF level compared with pure laparoscopic surgery. The combined approach improved postoperative recovery without prolonging the wound healing time or increasing the incidence of postoperative complications. The 3-year survival rate also increased. Thus, FTS combined with laparoscopic surgery can improve the prognosis in gastric antrum cancer.

Effect of different luteal support schemes on clinical outcome in frozen-thawed embryos transfer cycles

OBJECTIVE

To evaluate the clinical outcome of frozen-thawed embryo transfer (FET) when using different luteal support schemes.

STUDY DESIGN

Retrospective analysis of FET cycles was performed from June 2013 and December 2013. Infertile women, who underwent FET cycles utilizing embryos cryopreserved on day 3 post-insemination following an initial fresh IVF cycle. Patients were divided into three groups according to the luteal support scheme. Grade A (oral administration of progesterone, n=156), Group B (vaginal administration of progesterone, n=345), Group C (dissolved progesterone in oil with intramuscular infection, n=885), and group C was divided into two subgroups according to with (subgroup Cl, n=521) or without (subgroup C2 ,n=364) human chorionic gonadotrophi (hCG) injected intramuscularly. The authors compared patients' characteristics and the pregnancy outcomes of each group.

RESULTS

There was no difference in the patient characteristics of each group. There was no difference in the implantation rate or clinical and ongoing pregnancy rate among oral, vaginal, and intramuscular progesterone groups. The abortion and ectopic pregnancy rates were not significantly different among the three groups.

CONCLUSION

Oral progesterone in the FET cycles is convenient and has similar pregnancy outcomes compared with intramuscular or vaginal administration.

Shear stress regulates endothelial cell autophagy via redox regulation and Sirt1 expression

Disturbed cell autophagy is found in various cardiovascular disease conditions. Biomechanical stimuli induced by laminar blood flow have important protective actions against the development of various vascular diseases. However, the impacts and underlying mechanisms of shear stress on the autophagic process in vascular endothelial cells (ECs) are not entirely understood. Here we investigated the impacts of shear stress on autophagy in human vascular ECs. We found that shear stress induced by laminar flow, but not that by oscillatory or low-magnitude flow, promoted autophagy. Time-course analysis and flow cessation experiments confirmed that this effect was not a transient adaptive stress response but appeared to be a sustained physiological action. Flow had no effect on the mammalian target of rapamycin-ULK pathway, whereas it significantly upregulated Sirt1 expression. Inhibition of Sirt1 blunted shear stress-induced autophagy. Overexpression of wild-type Sirt1, but not the deacetylase-dead mutant, was sufficient to induce autophagy in ECs. Using both of gain- and loss-of-function experiments, we showed that Sirt1-dependent activation of FoxO1 was critical in mediating shear stress-induced autophagy. Shear stress also induced deacetylation of Atg5 and Atg7. Moreover, shear stress-induced Sirt1 expression and autophagy were redox dependent, whereas Sirt1 might act as a redox-sensitive transducer mediating reactive oxygen species-elicited autophagy. Functionally, we demonstrated that flow-conditioned cells are more resistant to oxidant-induced cell injury, and this cytoprotective effect was abolished after inhibition of autophagy. In summary, these results suggest that Sirt1-mediated autophagy in ECs may be a novel mechanism by which laminar flow produces its vascular-protective actions.

Parallel enzyme-linked immunosorbent assay screening for human immunodeficiency virus among blood donors in five Chinese blood centres: a retrospective analysis

AIMS

To evaluate the strategy of parallel screening with different enzyme-linked immunosorbent assays (ELISA) among Chinese blood donors.

BACKGROUND

Parallel screening with ELISA has been the main strategy to detect human immunodeficiency virus (HIV) in blood donations in China for more than a decade. The performance of the strategy should be analysed.

METHODS

A total of 821,927 donations collected from five Chinese blood centres in 2008-2010 were tested using two third-generation ELISAs by different manufacturers licenced and confirmed by the Western blot (WB) in this study. The confirmatory positive predictive values (PPV), false positive rates (FPR), false negative rates (FNR) and potential risks for transfusion resulting from single or sequential ELISA screening were evaluated.

RESULTS

A total of 5318 (0·647%) of donations screened HIV reactive and were discarded. WB confirmatory results on 1668 available samples suggested that PPVs for dual ELISA, one round ELISA reactive and grey zone samples were 75·1, 0·7 and 0·5%, respectively. Eight out of 1124 one round ELISA reactive and 1 out of 195 grey zone samples were WB confirmed positive. All but one ELISA assay displayed comparable PPVs but variable FPRs and FNRs that differed by blood centre.

CONCLUSIONS

In the absence of nucleic acid testing (NAT), parallel ELISA screening prevented a substantial number of HIV infected donations from entering the Chinese blood supply. However, the loss of false positive donors should be re-evaluated especially given the frequently reported blood supply shortage in China.

Two-year outcome of first-line antiretroviral therapy among HIV-1 vertically-infected children in Hanoi, Vietnam

A retrospective analysis of 86 HIV-1 vertically-infected Vietnamese children with a follow-up period >24 months after initiating antiretroviral therapy (ART) was performed from 2008 to 2012, to assess the outcome of first-line ART in resource-limited settings. Of the 86 children, 68 (79.1%) were treated successfully (plasma HIV-1 viral load [VL] <1000 copies/ml), and 63 (73.3%) had full viral suppression (VL <400 copies/ml) after 24 months of ART. No significant difference between successfully treated patients and failure groups was observed in VL, CD4(+) T-cell count or clinical stage at baseline; age at ART start; or ART regimen. All 14 children with VL >5000 copies/ml, one of four children with VL 1000-5000 copies/ml and none with VL <1000 copies/ml developed reverse transcriptase inhibitor (RTI)-resistance mutations by 24 months of ART. Y181C and M184V/I were the most dominant non-nucleoside and nucleoside RTI-resistance mutations, respectively (13/15, 86.7%). These findings suggest that VL testing after 24 months of ART can be used to efficiently differentiate ART failures among HIV-1 vertically-infected children in resource-limited settings.

Inhibition of farnesyl pyrophosphate synthase prevents angiotensin II-induced cardiac fibrosis in vitro

Farnesyl pyrophosphate synthase (FPPS)-catalysed isoprenoid intermediates are important for the activation of Ras homologue gene family, member A (RhoA) in angiotensin (Ang) II-induced cardiac fibrosis. This study was designed to investigate the specific role of FPPS in the development of cardiac fibrosis. We demonstrated that FPPS expression was elevated in both in-vivo and in-vitro models of Ang II-mediated cardiac fibrosis. FPPS inhibition by zolendronate and FPPS knock-down by a silencing lentivirus decreased the expression of cardiac fibrosis marker genes, including collagen I, collagen III and transforming growth factor (TGF)-β1. FPPS inhibition was reversed by geranylgeraniol (GGOH) and mimicked by RhoA knock-down with siRhoA. The antagonistic effect of GGOH on the zolendronate-mediated modulation of RhoA activation in Ang II-stimulated cardiac fibroblasts was demonstrated by a pull-down assay. Furthermore, FPPS knock-down also prevented RhoA activation by Ang II in vitro. In conclusion, FPPS and RhoA may be part of a signalling pathway that plays an important role in Ang II-induced cardiac fibrosis in vitro.

Repair of critical-sized bone defects with anti-miR-31-expressing bone marrow stromal stem cells and poly(glycerol sebacate) scaffolds

The repair of critical-sized defects (CSDs) is a significant challenge in bone tissue engineering. Combining the use of progenitor cells with gene therapy represents a promising approach for bone regeneration. MicroRNAs play important roles in most gene regulatory networks, regulate the endogenous expression of multiple growth factors and simultaneously modulate stem cell differentiation. Our previous study showed that knocking down miR-31 promotes the osteogenesis of bone marrow stromal stem cells (BMSCs). To investigate the therapeutic potential of cells engineered to express anti-miR-31 for CSD repair, lentiviral vectors encoding negative control, miR-31 precursor and anti-sense sequences were constructed and transduced into osteo-inductive BMSCs. The expression of osteogenic-specific genes, alkaline phosphatase activity and Alizarin Red S staining were investigated to evaluate the effects of miR-31 on the cell fate of BMSCs over a 3-week period. In addition, miR-31-modified BMSCs seeded on poly(glycerol sebacate) (PGS) scaffolds were used to repair 8 mm critical-sized calvarial defects in rats. The results showed that miR-31 suppression significantly increased the expression of osteogenic-specific genes in vitro at the mRNA and protein levels, and that robust new bone formation with high local bone mineral density was observed in the anti-miR groups in vivo. Moreover, the PGS scaffolds carrying anti-miR-31-expressing BMSCs exhibited good biocompatibility and a high regeneration rate (~60%) within in vivo bone defects. Our results suggest that miR-31 gene delivery affects the potential of BMSCs for osteogenic differentiation and bone regeneration and that PGS is a potential substrate for genetically modified, tissue-engineered bone in the repair of large bone defects.