Yes-associated protein nuclear translocation promotes anabolic activity in human articular chondrocytes.

OBJECTIVE: Yes-associated protein (YAP) has been widely studied as a mechanotransducer in many cell types, but its function in cartilage is controversial. The aim of this study was to identify the effect of YAP phosphorylation and nuclear translocation on the chondrocyte response to stimuli relevant to osteoarthritis (OA). DESIGN: Cultured normal human articular chondrocytes from 81 donors were treated with increased osmolarity media as an in vitro model of mechanical stimulation, fibronectin fragments (FN-f) or IL-1ß as catabolic stimuli, and IGF-1 as an anabolic stimulus. YAP function was assessed with gene knockdown and inhibition by verteporfin. Nuclear translocation of YAP and its transcriptional co-activator TAZ and site-specific YAP phosphorylation were determined by immunoblotting. Immunohistochemistry and immunofluorescence to detect YAP were performed on normal and OA human cartilage with different degrees of damage. RESULTS: Chondrocyte YAP/TAZ nuclear translocation increased under physiological osmolarity (400 mOsm) and IGF-1 stimulation, which was associated with YAP phosphorylation at Ser128. In contrast, catabolic stimulation decreased the levels of nuclear YAP/TAZ through YAP phosphorylation at Ser127. Following YAP inhibition, anabolic gene expression and transcriptional activity decreased. Additionally, YAP knockdown reduced proteoglycan staining and levels of type II collagen. Total YAP immunostaining was greater in OA cartilage, but YAP was sequestered in the cytosol in cartilage areas with more severe damage. CONCLUSIONS: YAP chondrocyte nuclear translocation is regulated by differential phosphorylation in response to anabolic and catabolic stimuli. Decreased nuclear YAP in OA chondrocytes may contribute to reduced anabolic activity and promotion of further cartilage loss.

Acute embolic stroke with large-vessel occlusion: does contact aspiration thrombectomy show superiority?

AIM: To compare the efficacy between contact aspiration thrombectomy and stent retriever thrombectomy in the treatment of acute embolic stroke patients with large vessel occlusion. MATERIALS AND METHODS: Between January 2019 and June 2020, data from consecutive acute ischaemic stroke patients who underwent either endovascular contact aspiration or stent retriever thrombectomy were analysed at one institution. The primary outcome was the full 90-day modified Rankin Scale (mRS) score. Ordinal logistic regression analysis was used to assess the association between thrombectomy approach and functional outcomes. RESULTS: A total of 156 patients were analysed. Among them, 57 (36.5%) patients underwent primary aspiration thrombectomy, while 99 (63.5%) patients underwent primary stent retriever thrombectomy. The median procedure time was significantly shorter in patients treated with aspiration (37 versus 56 minutes; p<0.001). Compared with those of patients who underwent stent retriever thrombectomy, successful recanalisation rates and favourable functional outcome rates were higher in patients who underwent the aspiration approach (94.7% versus 77.8%, p=0.006; 49.1% versus 27.3%, p=0.006, respectively). Ordinal logistic regression analysis showed that aspiration thrombectomy was independently associated with a good functional outcome (adjusted common odds ratio, 0.30, 95% confidence interval: 0.16-0.60, p<0.001). CONCLUSION: Among the specific patients with large vessel occlusion in acute embolic stroke, the use of aspiration thrombectomy compared with stent retriever thrombectomy resulted in a greater likelihood of favourable neurological outcomes; however, because of study limitations, these findings should be interpreted as preliminary and require further study to confirm these results.

Non-negligible clinical relevance of haemorrhagic transformation after endovascular thrombectomy with successful reperfusion in acute ischaemic stroke.

AIM: To explore the association between haemorrhagic transformation (HT) subtypes and functional outcome in acute ischaemic stroke (AIS) patients with successful recanalization treated by endovascular thrombectomy (EVT). MATERIALS AND METHODS: Consecutive patients with AIS due to large-vessel occlusion in the anterior circulation, who were treated between January 2015 and June 2019 and achieved successful EVT, were enrolled in this retrospective study. HT was categorized according to the Heidelberg Bleeding Classification. Functional outcome was evaluated using the 90-day modified Rankin Scale (mRS) after stroke onset. Ordinal logistic regression analysis was performed to determine the association of HT subtypes with functional outcomes. RESULTS: A total of 243 patients were included for further analysis. Among them, 121 (49.8%) had HT. Ten (4.1%) patients were classified as haemorrhagic infarction (HI) subtype 1, 61 (25.1%) as HI subtype 2, 17 (7.0%) as parenchymal haematoma (PH) subtype 1, and 33 (13.6%) as PH subtype 2. Ordinal logistic regression analysis suggested that HI subtype 2 (adjusted common OR 0.357, 95% CI: 0.192-0.667), PH1 (adjusted common OR 0.254, 95% CI: 0.093-0.696) and PH subtype 2 (adjusted common OR 0.017, 95% CI: 0.006-0.051) were significantly associated with poor functional outcomes. CONCLUSION: The present study shows that HI subtype 2, PH subtype 1, and PH subtype 2 are independently associated with poor clinical outcomes in AIS patients with successful recanalization after EVT.

All-optical multilevel amplitude regeneration in a single nonlinear optical loop mirror.

We experimentally demonstrate all-optical amplitude regeneration of 4-level pulse amplitude modulated signals (PAM4) based on a single nonlinear optical loop mirror (NOLM). Four power-plateau regions are achieved using return-to-zero (RZ) pulses of narrow pulse-width, enabling large nonlinear phase shifts within the highly nonlinear fiber (HNLF). We quantify noise suppression characteristics at each amplitude level and obtain an overall EVM improvement of 0.92dB by optimizing input power and distortion strength. A theoretical analysis has been also carried out matching the experimental results and revealing the design characteristics of the regenerator's nonlinear transfer function.

Robust and tunable 16.375Gb/s dual-band optical OFDM transmissions over directly modulated VCSEL-based 200m OM2 MMFs.

Utilizing low-cost, 2.2GHz modulation bandwidth, uncooled and standalone directly modulated VCSEL (DM-VCSEL)-based real-time dual-band optical OFDM (OOFDM) transmitters, aggregated 16.375Gb/s transmissions of OOFDM signals having bandwidths approximately 3.8 times higher than the VCSEL manufacturer-specified modulation bandwidths, are experimentally demonstrated, for the first time, over 200m OM2 MMF links based on intensity modulation and direct detection. The aggregated signal transmission capacities of the aforementioned links vary by just 8% for various OM2 MMFs ranging from 100m to 500m, and by just 10% over a 1GHz passband carrier frequency detuning range. Such dual-band OOFDM adaptability-induced excellent performance robustness and large passband frequency tunability can significantly relax the requirements on VCSEL modulation bandwidth for achieving specific transmission performances for cost-sensitive application scenarios such as data centers.

Self-seeding-based 10Gb/s over 25km optical OFDM transmissions utilizing face-to-face dual-RSOAs at gain saturation.

Self-seeded passive optical networks (PONs) are currently attracting extensive research interest. In this paper, a novel self-seeded PON transmitter is, for the first time, proposed and experimentally demonstrated, which incorporates two face-to-face-positioned reflective semiconductor optical amplifiers (RSOAs) operating at their gain saturation regions: one RSOA directly driven by an upstream electrical signal and the other RSOA biased at a fixed current. Detailed experimental explorations are undertaken of the dynamic performance characteristics of the proposed transmitter. It is shown that, in comparison with previously reported self-seeded transmitters each employing a reflective mirror and a single electrical signal-driven RSOA, the proposed transmitter has a number of salient advantages including, considerably narrowed optical signal spectra, up to 16dB reduction in RINs of intensity-modulated optical signals, and residual intensity modulation crosstalk suppression as high as 10.7dB. The aforementioned features enable experimental demonstrations of real-time self-seeded 10Gb/s optical OFDM (OOFDM) transmitters. In particular, by making use of two low-cost RSOAs having their 3-dB modulation bandwidths as small as 1.125GHz, 10Gb/s over 25km adaptive OOFDM transmissions with power penalties of 0.6dB are experimentally achieved in the simple self-seeded IMDD PON systems.

Lower dosing of enteric-coated mycophenolate sodium (Myfortic) can achieve target mycophenolic acid exposure rapidly in most Chinese renal transplant patients: a pilot study.

AIMS: There are few pharmacokinetic data for enteric-coated mycophenolate sodium (EC-MPS) in Chinese kidney transplant recipients. Previously, we demonstrated that patients with 540 mg EC-MPS reached target exposure on day 4 after transplantation. The aim of this study was further to confirm that mycophenolic acid (MPA) delivery with a daily total dose 1080 mg EC-MPS is adequate during the early-phase posttransplantation and preliminarily assess the pharmacokinetics after a single dose and multiple doses of EC-MPS in Chinese live-donor kidney transplant recipients. METHODS: Twelve patients (eight men and four women, mean age 41.3 ± 6.78 years) treated with EC-MPS, cyclosporine and corticosteroids were included in this study. Patients received a single oral dose of EC-MPS 540 mg, then 540 mg twice daily. MPA concentrations were measured by high-performance liquid chromatography. Twelve-hour pharmacokinetic profiles were obtained after the single oral dose and multiple doses on day 4 postoperation. The pharmacokinetic parameters were compared between a single dose and multiple doses. By using multiple stepwise regression analysis, we obtained two predictive equations of MPA systemic exposure. Bland-Altman analysis was developed to test agreement between the observed MPA area under the concentration-time curve (AUC) and the predicted MPA AUC. RESULTS: The mean (range) MPA AUC was 42 ± 14.67 (29.29-75.95) mg/l h after the first dose, and 44.72 ± 14.57 (32.06-80.79) mg/l h on day 4 after operation. MPA exposure provided by a single dose and multiple doses were similar (p > 0.05). The best equations obtained were the following: 20.003 + 1.181C6 h  + 7.22C8 h (r = 0.936) and 17.023 + 3.11C1 h  + 1.245 + 4.988C8 h (r = 0.964). These equation models showed an optimal agreement between the observed MPA AUC and the predicted MPA AUC. CONCLUSIONS: Lower dosing of EC-MPS, compared with the standard dose (720 mg twice daily), may provide enough MPA exposure for Chinese live-donor kidney transplant patients on day 4. Given that the MPA exposure by AUC correlates with the incidence of acute rejection episodes and transplant vasculopathy, the present findings may have clinical implications, and the optimum dose range of EC-MPS for patients in all ranges of body weight should also be determined.

[Multivariate analysis and construction and validation of a nomogram model from data of 1610 patients with non-tumor-related anastomotic stenosis after rectal cancer surgery].

Objective: To assess the risk factors affecting development of non-tumor- related anastomotic stenosis after rectal cancer and to construct a nomogram prediction model. Methods: This was a retrospective study of data of patients who had undergone excision with one-stage intestinal anastomosis for rectal cancer between January 2003 and September 2018 in Nanfang Hospital of Southern Medical University. The exclusion criteria were as follows: (1) pathological examination of the operative specimen revealed residual tumor on the incision margin of the anastomosis; (2) pathological examination of postoperative colonoscopy specimens revealed tumor recurrence at the anastomotic stenosis, or postoperative imaging evaluation and tumor marker monitoring indicated tumor recurrence; (3) follow-up time <3 months; and (4) simultaneous multiple primary cancers. Univariate analysis using the χ2 or Fisher's exact test was performed to assess the study patients' baseline characteristics and variables such as tumor-related factors and surgical approach (P<0.05). Multivariate analysis using binary logistic regression was then performed to identify independent risk factors for development of non-tumor-related anastomotic stenosis after rectal cancer. Finally, a nomogram model for predicting non-tumor-related anastomotic stenosis after rectal cancer surgery was constructed using R software. The reliability and accuracy of this prediction model was evaluated using internal validation and calculation of the area under the curve of the model's receiver characteristic curve (ROC). Results: The study cohort comprised 1,610 patients, including 1,008 men and 602 women of median age 59 (50, 67) years and median body mass index 22.4 (20.2, 24.5) kg/m². Non-tumor-related anastomotic stenosis developed in 121 (7.5%) of these patients. The incidence of non-tumor-related anastomotic stenosis in patients who had undergone neoadjuvant chemotherapy, neoadjuvant radiotherapy, and surgery alone was 11.2% (10/89), 26.4% (47/178), and 4.8% (64/1,343), respectively. Neoadjuvant treatment (neoadjuvant chemotherapy: OR=2.455, 95%CI: 1.148-5.253, P=0.021; neoadjuvant chemoradiotherapy, OR=3.882, 95%CI: 2.425-6.216, P<0.001), anastomotic leakage (OR=7.960, 95%CI: 4.550-13.926, P<0.001), open laparotomy (OR=3.412, 95%CI: 1.772-6.571, P<0.001), and tumor location (distance of tumor from the anal verge 5-10 cm: OR=2.381, 95%CI:1.227-4.691, P<0.001; distance of tumor from the anal verge <5 cm: OR=5.985,95% CI: 3.039-11.787, P<0.001) were identified as independent risk factors for non-tumor-related anastomotic stenosis. Thereafter, a nomogram prediction model incorporating the four identified risk factors for development of anastomotic stenosis after rectal cancer was developed. The area under the curve of the model ROC was 0.815 (0.773-0.857, P<0.001), and the C-index of the predictive model was 0.815, indicating that the model's calibration curve fitted well with the ideal curve. Conclusion: Non-tumor-related anastomotic stenosis after rectal cancer surgery is significantly associated with neoadjuvant treatment, anastomotic leakage, surgical procedure, and tumor location. A nomogram based on these four factors demonstrated good discrimination and calibration, and would therefore be useful for screening individuals at risk of anastomotic stenosis after rectal cancer surgery.

Ventral hernia repair with synthetic mesh in a contaminated field: a systematic review and meta-analysis.

PURPOSE: The use of mesh in ventral hernia repair becomes especially challenging when associated with a contaminated field. Permanent synthetic mesh use in this setting is currently debated and this discussion is yet to be resolved clinically or in the literature. We aim to systematically assess postoperative outcomes of non-absorbable synthetic mesh (NASM) used in ventral hernia repair in the setting of contamination. METHODS: A literature search of PubMed, Embase, Scopus, Cinahl, and Cochrane Library identified all articles from 2000-2020 that examined the use of NASM for ventral hernia repair in a contaminated field. Postoperative outcomes were assessed by means of pooled analysis and meta-analysis. Qualitative analysis was completed for all included studies using a modified Newcastle-Ottawa scale. RESULTS: Of 630 distinct publications and 104 requiring full review, this study included 17 articles published between 2007 and 2020. Meta-analysis demonstrated absorbable mesh was associated with more HR (OR 1.89, 1.15-3.12, p = 0.008), SSO (OR 1.43, 0.96-2.11, p = 0.087), SSI (OR 2.84, 1.85-4.35, p < 0.001), and unplanned reoperation (OR 1.99, 1.19-3.32, p = 0.009) compared to NASM. CONCLUSION: The use of NASM for ventral hernia repair in a contaminated field may be a safe alternative to absorbable mesh, as evidenced by lower rates of postoperative complications. This review counters the current clinical paradigm, and additional prospective randomized controlled trials are warranted.

Revealing time's secrets at the National Theatre of Costa Rica via innovative software for cultural heritage research.

Establishing affordable, efficient, accessible, innovative, and multidisciplinary methodologies to the diagnosis of the conservation state of an artwork is key to carry out appropriate strategies of conservation and consequently to the creation of modern public policies on cultural heritage. Limited access to large-format paintings is a challenge to restoration scientists seeking to obtain information quickly, in a non-destructive and non-invasive manner, and identify regions of interest. Therefore, we put forward two unique software tools based on multispectral imaging techniques, with the long-term aim to assess the artist's intentions, creative process, and colour palette. This development paves the way for a comprehensive and multidisciplinary understanding of the mysteries encompassed in each pictorial layer, through the study of their physical and chemical characteristics. We conducted the first ever study on Musas I and Musas II, two large-format paintings by Italian artist Carlo Ferrario, located in the National Theatre of Costa Rica. In this study, we used our novel imaging techniques to choose regions of interest in order to study sample layers; while also assessing the works' state of conservation and possible biodeterioration. We explored the applications of our two versatile software tools, RegionOfInterest and CrystalDistribution, and confirmed paint stratigraphies by means of microscopy and spectroscopy analyses (OM, SEM-EDX, Fluorescent microscopy, FTIR-ATR and micro-Raman). In a pilot study, we identified the artist's main colour palette: zinc white, lead white, chrome yellow, lead read, viridian, along with artificial vermilion and ultramarine pigments. We were able to identify artificial vermilion and ultramarine and distinguish them from the natural pigments using CrystalDistribution to map the average size and diameter of the pigment crystals within the paint layers. This study demonstrated that software-based multidisciplinary imaging techniques are novel in establishing preventive and non-invasive methods for historical painting conservation studies, in addition, this study provides tools with great potential to be used in the future in applications such as virtual restoration.

Systematic review with meta-analysis: combination treatment of regimens based on pegylated interferon for chronic hepatitis B focusing on hepatitis B surface antigen clearance.

BACKGROUND: The seroclearance of hepatitis B surface antigen (HBsAg) in patients with chronic hepatitis B (CHB) is considered to be associated with favourable clinical outcomes. AIMS: This meta-analysis was performed to establish the proportion of HBsAg loss rates among CHB patients who received combination treatment based on pegylated interferon (PegIFN). Four combination strategies have been studied with the aim of improving HBsAg loss: "de novo," "NA-experienced," "switch-to" and "add-on." This meta-analysis was performed to determine which, if any, of these combination strategies was more effective. METHODS: Medline, Web of Science and Embase databases were searched from inception to December 2017. The proportion of patients who achieved HBsAg loss after combination therapy was pooled using a random-effects model. RESULTS: Twenty-four studies fulfilled the meta-analysis criteria. The overall pooled proportion suggested that the rate of HBsAg loss could be increased to 9% (95% CI: 7%-12%) based on the combination treatment in CHB patients. Compared with "de novo" strategy (8%, 95% CI: 6%-10%), the "nucleos(t)ide analogues-experienced" (11%, 95% CI: 8%-15%) was found to be more likely (P = 0.036) to achieve a response. Compared with the "add-on" strategy (8%, 95% CI: 5%-13%), the "switch-to" (14%, 95% CI: 9%-20%) was found to be more likely (P = 0.012) to achieve HBsAg loss. CONCLUSION: The "nucleos(t)ide analogues-experienced" strategy was more effective than the "De novo" strategy in achieving HBsAg loss for CHB patients. Combination treatment using regimens based on Peg-IFN may be useful to help nucleos(t)ide analogues-treated patients, who have experienced at least 48 weeks of nucleot(s)ide analogue, achieve HBsAg seroclearance.

[A clinical analysis of micafungin treatment of pulmonary invasive fungal infection in pediatric patients with acute leukemia or post hematopoietic stem cells transplantation].

Objective: To investigate the efficacy and safety of micafungin (MCF) for pulmonary invasive fungal disease (PIFD) in pediatric patients with acute leukemia or post hematopoietic stem cells transplantation. Method: Twenty-five neutropenic PIFD children with acute leukemia or post hematopoietic stem cells transplantation in Sun Yat-sen Memorial Hospital of Sun Yat-sen University were selected from January 2012 to June 2015, including 12 males and 13 females, age range 2-15 (average 6.2±2.0) years. There were 12 cases of acute leukemia (AL) after chemotherapy, 4 cases of acute leukemia (AL) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) and 9 cases of ß-thalassemia major after allo-HSCT. All children received MCM for the treatment of PIFD, the dosage of MCM was 3-4 mg/ (kg·d) , once a day. The children received 2 to 6 courses of treatment, individually with a course of 7 days. 1, 3-ß-D glucan assay (G test), galactomannan antigen test (GM test), high-resolution CT and the biochemical indexes for organ functions were closely monitored. Result: Twenty-five cases were diagnosed as PIFD, including 2 patients diagnosed as proven, 6 as probable and 17 as possible. Of the 25 cases, 1 was confirmed aspergillus by biopsy pathology and 1 was candida albicans by blood culture. The G and GM test with positive results was 5 and 2 respectively. Chest CT scans of the 25 cases had obvious lesions: air crescent sign and cavitation in 4 cases, diffuse ground glass change in 9 cases, double lung scattered patchy, small nodules and cord like high density shadow in 7 cases, unilateral or bilateral chest wall wedge-shaped consolidation edge in 5 cases and pleural effusion in 5 patients. The effective rate of MCF in treatment of PIFD was 68% (17/25), including 13 cases cured, 4 cases improved, 4 cases were improved clinically and in 4 cases the treatment was ineffective. Eight cases were effective in MCF monotherapy group (12 cases) and nine were effective in MCF combined therapy group(13 cases), respectively. Side-effects including allergies, gastrointestinal side effects, electrolyte disturbances, impairment of liver and kidney function, and myelosuppression were not found in those children treated with MCF. Conclusion: Micafungin is effective and safe in the treatment of pulmonary invasive fungal disease in pediatric patients with acute leukemia or post hematopoietic stem cell transplantation.

Design and development of novel antibacterial Ti-Ni-Cu shape memory alloys for biomedical application.

In the case of medical implants, foreign materials are preferential sites for bacterial adhesion and microbial contamination, which can lead to the development of prosthetic infections. Commercially biomedical TiNi shape memory alloys are the most commonly used materials for permanent implants in contact with bone and dental, and the prevention of infections of TiNi biomedical shape memory alloys in clinical cases is therefore a crucial challenge for orthopaedic and dental surgeons. In the present study, copper has been chosen as the alloying element for design and development novel ternary biomedical Ti‒Ni‒Cu shape memory alloys with antibacterial properties. The effects of copper alloying element on the microstructure, mechanical properties, corrosion behaviors, cytocompatibility and antibacterial properties of biomedical Ti‒Ni‒Cu shape memory alloys have been systematically investigated. The results demonstrated that Ti‒Ni‒Cu alloys have good mechanical properties, and remain the excellent shape memory effects after adding copper alloying element. The corrosion behaviors of Ti‒Ni‒Cu alloys are better than the commercial biomedical Ti‒50.8Ni alloys. The Ti‒Ni‒Cu alloys exhibit excellent antibacterial properties while maintaining the good cytocompatibility, which would further guarantee the potential application of Ti‒Ni‒Cu alloys as future biomedical implants and devices without inducing bacterial infections.

Screening on binary Ti alloy with excellent mechanical property and castability for dental prosthesis application.

In the present study, the microstructure, mechanical property, castability, corrosion behavior and in vitro cytocompatibility of binary Ti-2X alloys with various alloying elements, including Ag, Bi, Ga, Ge, Hf, In, Mo, Nb, Sn and Zr, were systematically investigated, in order to assess their potential applications in dental field. The experimental results showed that all binary Ti‒2X alloys consisted entirely α-Ti phase. The tensile strength and microhardness of Ti were improved by adding alloying elements. The castability of Ti was significantly improved by separately adding 2 wt.% Bi, Ga, Hf, Mo, Nb, Sn and Zr. The corrosion resistance of Ti in both normal artificial saliva solution (AS) and extreme artificial saliva solution (ASFL, AS with 0.2 wt.% NaF and 0.3 wt.% lactic acid) has been improved by separately adding alloying elements. In addition, the extracts of studied Ti‒2X alloys produced no significant deleterious effect to both fibroblasts L929 cells and osteoblast-like MG63 cells, indicating a good in vitro cytocompatibility, at the same level as pure Ti. The combination of enhanced mechanical properties, castability, corrosion behavior, and in vitro cytocompatibility make the developed Ti‒2X alloys have great potential for future stomatological applications.

Microstructure, mechanical properties, castability and in vitro biocompatibility of Ti-Bi alloys developed for dental applications.

In this study, the microstructure, mechanical properties, castability, electrochemical behaviors, cytotoxicity and hemocompatibility of Ti-Bi alloys with pure Ti as control were systematically investigated to assess their potential applications in the dental field. The experimental results showed that, except for the Ti-20Bi alloy, the microstructure of all other Ti-Bi alloys exhibit single α-Ti phase, while Ti-20Bi alloy is consisted of mainly α-Ti phase and a small amount of BiTi2 and BiTi3 phases. The tensile strength, hardness and wear resistance of Ti-Bi alloys were demonstrated to be improved monotonically with the increase of Bi content. The castability test showed that Ti-2Bi alloy increased the castability of pure Ti by 11.7%. The studied Ti-Bi alloys showed better corrosion resistance than pure Ti in both AS (artificial saliva) and ASFL (AS containing 0.2% NaF and 0.3% lactic acid) solutions. The concentrations of both Ti ion and Bi ion released from Ti-Bi alloys are extremely low in AS, ASF (AS containing 0.2% NaF) and ASL (AS containing 0.3% lactic acid) solutions. However, in ASFL solution, a large number of Ti and Bi ions are released. In addition, Ti-Bi alloys produced no significant deleterious effect to L929 cells and MG63 cells, similar to pure Ti, indicating a good in vitro biocompatibility. Besides, both L929 and MG63 cells perform excellent cell adhesion ability on Ti-Bi alloys. The hemolysis test exhibited that Ti-Bi alloys have an ultra-low hemolysis percentage below 1% and are considered nonhemolytic. To sum up, the Ti-2Bi alloy exhibits the optimal comprehensive performance and has great potential for dental applications.

Development of biodegradable Zn-1X binary alloys with nutrient alloying elements Mg, Ca and Sr.

Biodegradable metals have attracted considerable attentions in recent years. Besides the early launched biodegradable Mg and Fe metals, Zn, an essential element with osteogenic potential of human body, is regarded and studied as a new kind of potential biodegradable metal quite recently. Unfortunately, pure Zn is soft, brittle and has low mechanical strength in the practice, which needs further improvement in order to meet the clinical requirements. On the other hand, the widely used industrial Zn-based alloys usually contain biotoxic elements (for instance, ZA series contain toxic Al elements up to 40 wt.%), which subsequently bring up biosafety concerns. In the present work, novel Zn-1X binary alloys, with the addition of nutrition elements Mg, Ca and Sr were designed (cast, rolled and extruded Zn-1Mg, Zn-1Ca and Zn-1Sr). Their microstructure and mechanical property, degradation and in vitro and in vivo biocompatibility were studied systematically. The results demonstrated that the Zn-1X (Mg, Ca and Sr) alloys have profoundly modified the mechanical properties and biocompatibility of pure Zn. Zn-1X (Mg, Ca and Sr) alloys showed great potential for use in a new generation of biodegradable implants, opening up a new avenue in the area of biodegradable metals.

Local projections of GABAergic neurons in the dentate gyrus and CA1 region in the rat hippocampal formation.

Using retrograde transport of wheat germ agglutinin conjugated colloidal gold (WGA-gold) combined with immunoreactivity for glutamate decarboxylase (GAD), a specific synthesizing enzyme for gamma-aminobutyric acid (GABA), local projections of GABAergic neurons in the dentate gyrus and CA1 were examined. In the hilus of the dentate gyrus, it was found that GABAergic neurons in the granule cell layer projected to the ipsilateral upper leaf of the molecular layer, with a mediolateral extension of more than 1.2 mm and a rostrocaudal extension of over 0.8 mm. Non-GABAergic neurons in nearly the entire hilar area were found to project to the ipsilateral upper leaf of the molecular layer. In the dorsal CA1 region, GABAergic neurons in the stratum pyramidale and radiatum converged onto the ipsilateral stratum pyramidal/oriens, with a mediolateral extension of over 1 mm and a rostrocaudal extension of over 0.7 mm. These results provide direct evidence that in both the dentate gyrus and CA1, GABAergic interneurons from a fairly large field converge onto a very small target area. This suggests that the output signals from GABAergic neurons in the dentate gyrus and CA1, and non-GABAergic neurons in the dentate gyrus, may propagate beyond the anatomical limits contained in conventional slice preparations of the hippocampal formation.

Merocyanine 540-sensitized photoinactivation of leukemia cells: effects of dose fractionation.

The differential sensitivity to merocyanine 540 (MC540)-sensitized photoirradiation of leukemia cells, selected solid tumor cells, and normal pluripotent hematopoietic stem cells has been successfully exploited for the extracorporeal purging of simulated autologous remission bone marrow grafts. In this communication, we compare the effects of fractionated vs continuous irradiation upon the MC540-sensitized photoinactivation of L1210 and K562 leukemia cells. Exposure to MC540 (15 micrograms/mL) and fractionated doses of white light inactivated fewer in vitro clonogenic cells than exposure to an equivalent dose of continuous irradiation, provided the irradiation doses were small (8.1-16.2 kJ/m2) and spaced 1-2 h apart. The dye-sensitized photoinactivation of leukemia cells was enhanced when cells were stored at 4 degrees C instead of 37 degrees C between irradiation periods, most likely in part because the cells were unable to repair sublethal photodynamic damages at the lower temperature. These data suggest that cells can recover from sublethal damage inflicted by the plasma membrane-active photosensitizer, MC540.

Limited cell-cycle dependence of the merocyanine 540-sensitized photoinactivation of L1210 leukemia cells.

L1210 leukemia cells were synchronized by a double thymidine block technique and then characterized with regard to their susceptibility to merocyanine 540 (MC540)-sensitized photoinactivation. Cells harvested 5 (G2/M phase) h after release from the second thymidine block were most susceptible to MC540-sensitized photoinactivation followed, in order of decreasing sensitivity, by cells harvested 2 (S phase) h and by cells harvested 7 (G1 phase) h after release from the second block. The expression of dye-binding sites changed very little during the cell cycle.

Ti-Ga binary alloys developed as potential dental materials.

In this study, the microstructure, mechanical properties, castability, electrochemical behaviors and cytotoxicity of as-cast Ti-Ga alloys with pure Ti as control were systematically investigated to assess their potential application in dental field. The results of OM and XRD showed that the microstructure of all experimental as-cast Ti-Ga alloys exhibited single α-Ti phase at room temperature. Mechanical tests indicated that the tensile strength, Young's modulus, microhardness and wear resistance were improved monotonically with the increase of Ga content. The castability test showed that Ti-2Ga alloy increased the castability value of pure Ti by 14.2(±3.8)% (p<0.05). The electrochemical behaviors in both artificial saliva solutions indicated that the studied Ti-Ga alloys showed better corrosion resistance than pure Ti. The cytotoxicity test suggested that the studied Ti-Ga alloys produced no significant deleterious effect to L929 fibroblast cells and MG63 osteosarcoma cells, similar to pure Ti, indicating an excellent in vitro biocompatibility. The cell morphology test showed that both L929 and MG63 cells process excellent cell adhesion ability on all experimental materials. Considering all these results, Ti-2Ga alloy exhibits the optimal comprehensive performance and has potential for dental applications.