Introduction of an interface layer on hydroxyapatite whisker/poly(L-lactide) composite and its contribution for improved bioactivity and mechanical properties.

A hydroxyapatite whisker (w-HA) was synthesized via dissolution-precipitation by forming calcium-ethylene diamine tetra acetic acid (Ca-EDTA) complexing. The hydroxyapatite whisker was formed with precipitation of Ca2+ along the c-axis due to the space inhibition of Ca-EDTA complex during refluxing. The op-w-HA (oligomeric poly(lactic acid) modified w-HA), p-w-HA (poly(L-lactide) modified w-HA) and pc-w-HA (poly(L-lactide) and cyclodextrin modified w-HA) were obtained via the surface modification of w-HA. The particle size, surface charge and biocompatibility of theses modified w-HA particles were successfully adjusted. Among these materials, pc-w-HA exhibited nearly no toxicity, better adhesion to mesenchymal stem cells (MSCs) (5 times better than w-HA) and greater osteoinductivity among the obtained materials (40% of mineralized extracellular matrix higher than w-HA) due to better surface properties. Different kinds of powders (w-HA, p-w-HA and pc-w-HA) were blended with PLLA (poly(L-Lactide)) to form a composite material, respectively. The pc-w-HA/PLLA composite showed better mechanical properties (tensile strength of the pc-w-HA/PLLA composite was 22.3% higher than that of w-HA/PLLA), which could be attributed to mainly two factors including the structure preservation of w-HA bundles and pseudorotaxane linkage between PLA-cyclodextrin and PLLA. The MSCs adhesion of the pc-w-HA/PLLA composite was much better due to balanced hydrophilicity/hydrophobicity and surface roughness. This surface modification method could provide a new and effective strategy for the preparation of bioresorbable composite material with great bioactivity and mechanical property, which has great potential in the medical device industry.

Surgery of the Primary Tumor Offers Survival Benefits of Breast Cancer with Synchronous Ipsilateral Supraclavicular Lymph Node Metastasis.

BACKGROUND: Controversy exists around the locoregional management of the primary tumor for breast cancer associated with synchronous ipsilateral supraclavicular lymph node metastasis (sISLM) due to the rarity of the disease and limited available data. This study aimed to compare outcomes of patients in the Surveillance, Epidemiology, and End Results (SEER) database with sISLM who underwent surgical resection and radiation of the primary tumor with those who did not. METHODS: This population-based retrospective study included breast cancer patients with sISLM without distant metastases from 2004 to 2016 in the SEER database. In this study, patients had been stratified by operative management, and propensity score matching (PSM) had been successfully applied. RESULTS: A total of 1172 breast cancer patients with sISLM were included in the study: 863 (73.6%) of patients underwent the primary tumor resection, and 309 (26.4%) patients did not undergo surgery. The median survival time in the surgery group was longer compared to the nonsurgery group in the overall cohort and the PSM cohort. We concluded that the primary tumor resection was associated with improved survival. Subgroup analysis further demonstrated that local surgery was not inferior to radical surgery. CONCLUSION: For selected breast cancer patients with sISLM, surgery is a promising local intervention which may improve the survival.

Chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis promote chemoresistance by activating the NF-κB pathway in breast cancer cells.

BACKGROUND: Chemotherapy is the primary established systemic treatment for patients with breast cancer, especially those with the triple-negative subtype. Simultaneously, the resistance of triple-negative breast cancer (TNBC) to chemotherapy remains a major clinical problem. Our previous study demonstrated that the expression levels of PTN and its receptor PTPRZ1 were upregulated in recurrent TNBC tissue after chemotherapy, and this increase was closely related to poor prognosis in those patients. However, the mechanism and function of chemotherapy-driven increases in PTN/PTPRZ1 expression are still unclear. METHODS: We compared the expression of PTN and PTPRZ1 between normal breast and cancer tissues as well as before and after chemotherapy in cancer tissue using the microarray analysis data from the GEPIA database and GEO database. The role of chemotherapy-driven increases in PTN/PTPRZ1 expression was examined with a CCK-8 assay, colony formation efficiency assay and apoptosis analysis with TNBC cells. The potential upstream pathways involved in the chemotherapy-driven increases in PTN/PTPRZ1 expression in TNBC cells were explored using microarray analysis, and the downstream mechanism was dissected with siRNA. RESULTS: We demonstrated that the expression of PTN and PTPRZ1 was upregulated by chemotherapy, and this change in expression decreased chemosensitivity by promoting tumour proliferation and inhibiting apoptosis. CDKN1A was the critical switch that regulated the expression of PTN/PTPRZ1 in TNBC cells receiving chemotherapy. We further demonstrated that the mechanism of chemoresistance by chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis depended on the NF-κB pathway. CONCLUSIONS: Our studies indicated that chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis play a critical role in chemoresistance, which suggests a novel strategy to enhance chemosensitivity in breast cancer cells, especially in those of the triple-negative subtype.

Image restoration method for longitudinal laser tomography based on degradation matrix estimation.

Target images captured by longitudinal laser tomography are usually degraded by nonuniform laser beams transmitting through inhomogeneous scattering mediums. An image restoration method with a total variation model is proposed for eliminating the main influence of inhomogeneous scattering mediums from degraded target images. Based on the physical signal relevance between the target layer and the scattering medium layer, the degradation matrix of the target image is approximately estimated by the specified backscattering images of the scattering mediums. Simulations and experiments are performed to verify the validity and feasibility of the proposed method, and all the results demonstrate that the proposed model works well and helps us to achieve the real target images, which represent the reflectivity distributions of the targets standing behind the inhomogeneous scattering mediums and which will benefit target recognition and identification.

Epoxidized Soybean Oleic Acid/Oligomeric Poly(lactic acid)-Grafted Nano-Hydroxyapatite and Its Role as a Filler in Poly(L-lactide) for Potential Bone Fixation Application.

One of the most effective strategies for modifying the surface properties of nano-fillers and enhancing their composite characteristics is through polymer grafting. In this study, a coprecipitation method was employed to modify hydroxyapatite (HAP) with epoxidized soybean oleic acid (ESOA), resulting in ESOA-HAP. Subsequently, oligomeric poly(lactic acid) (OPLA) was grafted onto the surface of ESOA-HAP, yielding OPLA-ESOA-HAP. HAP, ESOA-HAP, and OPLA-ESOA-HAP were comprehensively characterized. The results demonstrate the progressive grafting of ESOA and OPLA onto the surface of HAP, resulting in enhanced hydrophobicity and improved dispersity in organic solvent for OPLA-ESOA-HAP compared to HAP. The vitality and adhesion of Wistar rat mesenchymal stem cells (MSCs) were assessed using HAP and modified HAP materials. Following culture with MSCs for 72 h, the OPLA-ESOA-HAP showed an inhibition rate lower than 23.0% at a relatively high concentration (1.0 mg/mL), which is three times lower compared to HAP under similar condition. The cell number for OPLA-ESOA-HAP was 4.5 times higher compared to HAP, indicating its superior biocompatibility. Furthermore, the mechanical properties of the OPLA-ESOA-HAP/PLLA composite almost remained unaltered ever after undergoing two stages of thermal processing involving melt extrusion and inject molding. The increase in the biocompatibility and relatively high mechanical properties render OPLA-ESOA-HAP/PLLA a potential material for the biodegradable fixation system.

Angular velocity estimation from measurement vectors of star tracker.

In most spacecraft, there is a need to know the craft's angular rate. Approaches with least squares and an adaptive Kalman filter are proposed for estimating the angular rate directly from the star tracker measurements. In these approaches, only knowledge of the vector measurements and sampling interval is required. The designed adaptive Kalman filter can filter out noise without information of the dynamic model and inertia dyadic. To verify the proposed estimation approaches, simulations based on the orbit data of the challenging minisatellite payload (CHAMP) satellite and experimental tests with night-sky observation are performed. Both the simulations and experimental testing results have demonstrated that the proposed approach performs well in terms of accuracy, robustness, and performance.

Photodynamic therapy as salvage therapy for residual microscopic cancer after ultra-low anterior resection: A case report.

BACKGROUND: The rate of positive resection margins (R1) in patients with low rectal cancer is substantial. Recommended remedies such as extended resection or chemoradiotherapy have their own serious drawbacks. It has been reported that photodynamic therapy (PDT) as a remedial treatment for esophageal cancer. Colorectal cancer and esophageal cancer has many similarities, however, PDT as a salvage therapy for rectal cancer is rare. CASE SUMMARY: Here, we describe a 56-year-old man who was admitted to the hospital due to a 6-mo history of hemafecia, which had been aggravated for 1 mo. Colonoscopy revealed a 3 cm × 4 cm ulcerated mass in the rectum 4 cm from the anus. Preoperative pathological examination showed villous adenoma, moderate-to-high-grade dysplasia, good differentiation, and invasion of the mucosal muscle. The patient had R1 after ultra-low anterior resection, but he refused extended resection and experienced severe liver function impairment after 3 cycles of chemotherapy. Ultimately, the patient underwent PDT to remove R1. After five years of follow-up, there was no liver function impairment, recurrence, metastasis, sexual dysfunction, or abnormal defecation function. CONCLUSION: This is the first case worldwide in which R1 of rectal cancer were successfully treated by PDT.

[Laparoscopic partial gastrectomy: Analysis of 18 procedures].

OBJECTIVE: To explore the laparoscopic partial gastrectomy and the indications. METHODS: Eighteen patients who underwent laparoscopic partial gastrectomy from August 2005 to May 2006 were analyzed retrospectively. RESULTS: Sixteen patients (including 6 with gastric cancer, 9 with duodenal ulcer, and 1 with gastric multiple polyps) underwent laparoscopic partial gastrectomy. The other two patients underwent an open surgical procedure (1 patient with the tumor size large than 6 cm, and the other patient with bleeding after loosening one clip). The rate of intraoperative subcutaneous emphysema was 5.88% (1/17), and no death occurred. The operation time was (285+/-30)min on average, the estimated blood loss was (130+/-50)mL, and the hospitalization was (11+/-4)d. One case of obstruction of distal loop happened after the surgery, and the rate was 6.25% (1/16). The patients were followed up for 1 approximately 9 months postoperatively. Trocar puncture-site metastases occurred in one patient. CONCLUSION: Laparoscopic partial gastrectomy is safe and feasible with skillful laparoscopic technique and with restricted indications, and the surgical outcome may be similar to that of the open surgery.

Towards a full understanding of the nature of Ni(II) species and hydroxyl groups over highly siliceous HZSM-5 zeolite supported nickel catalysts prepared by a deposition-precipitation method.

Highly siliceous HZSM-5 zeolite supported nickel catalysts prepared by a deposition-precipitation (D-P) method were characterized by Fourier transform infrared (FT-IR), hydrogen temperature programmed reduction (H2-TPR), X-ray diffraction (XRD), N2-absorption/desorption, field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and (27)Al magic-angle nuclear magnetic resonance (MAS NMR) techniques. The results showed that the D-P of nickel species occurred predominantly on the internal surface of highly siliceous HZSM-5 zeolite, in which the internal silanol groups located on the hydroxylated mesopores or nanocavities played a key role. During the D-P process, nickel hydroxide was first deposited-precipitated via olation/polymerization of neutral hydroxoaqua nickel species over the HZSM-5 zeolite. With the progress of the D-P process, 1 : 1 nickel phyllosilicate was formed over the HZSM-5 via the hetero-condensation/polymerization between charged hydroxoaqua nickel species and monomer silicic species generated due to the partial dissolution of the HZSM-5 framework. The 1 : 1 nickel phyllosilicate could also be generated via the hydrolytic adsorption of hydroxoaqua nickel species and their subsequent olation condensation. After calcination, the deposited-precipitated nickel hydroxide was decomposed into nickel oxide, while the 1 : 1 nickel phyllosilicate was transformed into 2 : 1 nickel phyllosilicate. According to the above mechanism, Ni(ii) species were present both in the form of nickel oxide and 2 : 1 nickel phyllosilicate, which were mutually separated from each other, being highly dispersed over HZSM-5 zeolite.

[Difference in expression of VEGF, bFGF and their receptors between the young and postmenopausal women with breast cancer].

OBJECTIVE: To study the difference in the expression of VEGF, bFGF and their receptors between young and postmenopausal women with breast cancer. METHODS: The expression of VEGF, FLK-1, bFGF and FLG in 40 young and 30 postmenopausal women with breast cancer was studied by immunohistochemical method (SABC), with its relation with axillary lymph node metastasis and the clinical and pathologic characteristics. The expression index between these two groups was compared. RESULTS: The positive axillary lymph node rate and the mean expression of VEGF, bFGF in the young group were higher than postmenopausal group (P < 0.01 and P < 0.05), respectively. The mean expression of VEGF, bFGF, FLK-1 and FLG of axillary lymph node positive patients was higher than the negative ones both in young and postmenopausal women groups (P < 0.05 and P < 0.01). There was also a significant difference in VEGF, bFGF, FLK-1, FLG and MVC between the stage 0 - II and stage III - IV (P < 0.05 and P < 0.01) in both groups. CONCLUSION: Breast cancer angiogenesis, characterized by the high expression of VEGF and bFGF, is directly correlated with the high tumor aggressiveness in the young women.

X-ray repair cross-complementing group 1(XRCC1) genetic polymorphisms and thyroid carcinoma risk: a meta-analysis.

A number of studies have been conducted to explore the association of XRCC1 polymorphisms with thyroid cancer risk, but the results have been inconsistent. Thus we performed the present meta-analysis to clarify this issue based on all of the evidence available to date. Relevant studies were retrieved by searching PubMed and statistical analysis conducted using Stata software. Nine studies were included in this meta-analysis (1,620 cases and 3,557 controls). There were 6 studies (932 cases and 2,270 controls) of the Arg194Trp polymorphism, 7 studies (1432 cases and 3356 controls) of the Arg280His polymorphism and 9 studies (1,620 cases and 3,557 controls) for the Arg399Gln polymorphism. No association of XRCC1 Arg194Trp, Arg280His and Arg399Gln polymorphism with thyroid cancer risk was observed in the overall analysis. However, subgroup analysis revealed: 1) an elevated risk in aa vs AA analysis (OR=2.03, 95%CI= 1.24-3.31) and recessive genetic model analysis (OR=1.93, 95%CI= 1.20-3.08) in the larger sample size trials for XRCC1 Arg194Trp polymorphism; 2) a decreased thyroid cancer risk on subgroup analysis based on ethnicity in Aa vs AA analysis (OR=0.84, 95%CI= 0.72-0.98) and in a dominant genetic model (OR=0.84, 95%CI= 0.72-0.97) in Caucasian populations for the XRCC1 Arg399Gln polymorphism; 3) a decreased thyroid cancer risk on subgroup analysis based on design type in Aa vs AA analysis (OR=0.72, 95% CI= 0.54-0.97) among the PCC trials for the Arg399Gln polymorphism. Our results suggest that the XRCC1 Arg399Gln polymorphism may be associated with decreased thyroid cancer risk among Caucasians and XRCC1 Arg194Trp may be associated with a tendency for increased thyroid cancer risk in the two larger sample size trials.