Enhanced diabetic wound healing using platelet-derived extracellular vesicles and reduced graphene oxide in polymer-coordinated hydrogels.

Impaired wound healing is a significant complication of diabetes. Platelet-derived extracellular vesicles (pEVs), rich in growth factors and cytokines, show promise as a powerful biotherapy to modulate cellular proliferation, angiogenesis, immunomodulation, and inflammation. For practical home-based wound therapy, however, pEVs should be incorporated into wound bandages with careful attention to delivery strategies. In this work, a gelatin-alginate hydrogel (GelAlg) loaded with reduced graphene oxide (rGO) was fabricated, and its potential as a diabetic wound dressing was investigated. The GelAlg@rGO-pEV gel exhibited excellent mechanical stability and biocompatibility in vitro, with promising macrophage polarization and reactive oxygen species (ROS)-scavenging capability. In vitro cell migration experiments were complemented by in vivo investigations using a streptozotocin-induced diabetic rat wound model. When exposed to near-infrared light at 2 W cm- 2, the GelAlg@rGO-pEV hydrogel effectively decreased the expression of inflammatory biomarkers, regulated immune response, promoted angiogenesis, and enhanced diabetic wound healing. Interestingly, the GelAlg@rGO-pEV hydrogel also increased the expression of heat shock proteins involved in cellular protective pathways. These findings suggest that the engineered GelAlg@rGO-pEV hydrogel has the potential to serve as a wound dressing that can modulate immune responses, inflammation, angiogenesis, and follicle regeneration in diabetic wounds, potentially leading to accelerated healing of chronic wounds.

Bioinspired and self-restorable alginate-tyramine hydrogels with plasma reinforcement for arthritis treatment.

Long-standing administration of disease-modifying antirheumatic drugs confirms their clinical value for managing rheumatoid arthritis (RA). Nevertheless, there are emergent worries over unwanted adverse risks of systemic drug administration. Hence, a novel strategy that can be used in a drug-free manner while diminishing side effects is immediately needed, but challenges persist in the therapy for RA. To this end, herein we conjugated tyramine (TYR) with alginate (ALG) to form ALG-TYR and then treated it for 5 min with oxygen plasma (ALG-TYR + P/5 min). It was shown that the ALG-TYR + P/5 min hydrogel exhibited favorable viscoelastic, morphological, mechanical, biocompatible, and cellular heat-shock protein amplification behaviors. A thorough physical and structural analysis was conducted on the ALG-TYR + P/5 min hydrogel, revealing favorable physical characteristics and uniform porous structural features within the hydrogel. Moreover, ALG-TYR + P/5 min not only effectively inhibited inflammation of RA but also potentially regulated lesion immunity. Once ALG-TYR + P/5 min was intra-articularly administered to joints of rats with zymosan-induced arthritis, we observed that ALG-TYR + P/5 min could ameliorate syndromes of RA joint. This bioinspired and self-restorable ALG-TYR + P/5 min hydrogel can thus serve as a promising system to provide prospective outcomes to potentiate RA therapy.

CRISPR/Cas9 as a therapeutic tool for triple negative breast cancer: from bench to clinics.

Clustered regularly interspaced short palindromic repeats (CRISPR) is a third-generation genome editing method that has revolutionized the world with its high throughput results. It has been used in the treatment of various biological diseases and infections. Various bacteria and other prokaryotes such as archaea also have CRISPR/Cas9 systems to guard themselves against bacteriophage. Reportedly, CRISPR/Cas9-based strategy may inhibit the growth and development of triple-negative breast cancer (TNBC) via targeting the potentially altered resistance genes, transcription, and epigenetic regulation. These therapeutic activities could help with the complex issues such as drug resistance which is observed even in TNBC. Currently, various methods have been utilized for the delivery of CRISPR/Cas9 into the targeted cell such as physical (microinjection, electroporation, and hydrodynamic mode), viral (adeno-associated virus and lentivirus), and non-viral (liposomes and lipid nano-particles). Although different models have been developed to investigate the molecular causes of TNBC, but the lack of sensitive and targeted delivery methods for in-vivo genome editing tools limits their clinical application. Therefore, based on the available evidences, this review comprehensively highlighted the advancement, challenges limitations, and prospects of CRISPR/Cas9 for the treatment of TNBC. We also underscored how integrating artificial intelligence and machine learning could improve CRISPR/Cas9 strategies in TNBC therapy.

Plasma-Derived Nanoclusters for Site-Specific Multimodality Photo/Magnetic Thrombus Theranostics.

Traditional thrombolytic therapeutics for vascular blockage are affected by their limited penetration into thrombi, associated off-target side effects, and low bioavailability, leading to insufficient thrombolytic efficacy. It is hypothesized that these limitations can be overcome by the precisely controlled and targeted delivery of thrombolytic therapeutics. A theranostic platform is developed that is biocompatible, fluorescent, magnetic, and well-characterized, with multiple targeting modes. This multimodal theranostic system can be remotely visualized and magnetically guided toward thrombi, noninvasively irradiated by near-infrared (NIR) phototherapies, and remotely activated by actuated magnets for additional mechanical therapy. Magnetic guidance can also improve the penetration of nanomedicines into thrombi. In a mouse model of thrombosis, the thrombosis residues are reduced by ≈80% and with no risk of side effects or of secondary embolization. This strategy not only enables the progression of thrombolysis but also accelerates the lysis rate, thereby facilitating its prospective use in time-critical thrombolytic treatment.

Facilitated and Controlled Strontium Ranelate Delivery Using GCS-HA Nanocarriers Embedded into PEGDA Coupled with Decortication Driven Spinal Regeneration.

BACKGROUND AND PURPOSE: Strontium ranelate (SrR) is an oral pharmaceutical agent for osteoporosis. In recent years, numerous unwanted side effects of oral SrR have been revealed. Therefore, its clinical administration and applications are limited. Hereby, this study aims to develop, formulate, and characterize an effective SrR carrier system for spinal bone regeneration. METHODS: Herein, glycol chitosan with hyaluronic acid (HA)-based nanoformulation was used to encapsulate SrR nanoparticles (SrRNPs) through electrostatic interaction. Afterward, the poly(ethylene glycol) diacrylate (PEGDA)-based hydrogels were used to encapsulate pre-synthesized SrRNPs (SrRNPs-H). The scanning electron microscope (SEM), TEM, rheometer, Fourier-transform infrared spectroscopy (FTIR), and dynamic light scattering (DLS) were used to characterize prepared formulations. The rabbit osteoblast and a rat spinal decortication models were used to evaluate and assess the developed formulation biocompatibility and therapeutic efficacy. RESULTS: In vitro and in vivo studies for cytotoxicity and bone regeneration were conducted. The cell viability test showed that SrRNPs exerted no cytotoxic effects in osteoblast in vitro. Furthermore, in vivo analysis for new bone regeneration mechanism was carried out on rat decortication models. Radiographical and histological analysis suggested a higher level of bone regeneration in the SrRNPs-H-implanted groups than in the other experimental groups. CONCLUSION: Local administration of the newly developed formulated SrR could be a promising alternative therapy to enhance bone regeneration in bone-defect sites in future clinical applications.

Strontium ranelate-laden near-infrared photothermal-inspired methylcellulose hydrogel for arthritis treatment.

Rheumatoid arthritis (RA) is of foremost concern among long-term autoimmune disorders, as it leads to inflammation, exudates, chondral degeneration, and painful joints. Because RA severity often fluctuates over time, a local drug delivery method that titrates release of therapeutics to arthritis bioactivity should represent a promising paradigm of RA therapy. Given the local nature of RA chronic illnesses, polysaccharide-drug delivering systems have the promise to augment therapeutic outcomes by offering controlled release of bioactive materials, diminishing the required frequency of administration, and preserving therapeutic levels in affected pathological regions. Herein, an intra-articular photothermal-laden injectable methylcellulose (MC) polymeric hydrogel carrier incorporating strontium ranelate (SrR) and sodium chloride was investigated to resolve these issues. Physicochemical and cellular characteristics of the MC carrier system were thoroughly evaluated. The slow release of SrR, enhancement of the material mechanical strength, and the potential of the non-invasive near-infrared photothermal gel to improve blood circulation and suppress inflammation in a mini-surgical model of RA were examined. Biocompatibility and suppression of intracellular ROS-induced inflammation were observed. This multifunctional photothermal MC hydrogel carrier is anticipated to be an alternative approach for future orthopedic disease treatment.

A bi-phase core-shell structure of Mg-based bulk metallic glass for application in orthopedic fixation implants.

Mg-based bulk metallic glass (BMG) and its composites have been promising candidates for orthopedic fixation implants because of their biocompatibility, low degradation rate, and osteogenic potential. However, the amorphous state is affected by the cooling rate during the casting process. Solid, unstable structures combined with amorphous and crystalline structures are generated when an insufficient cooling rate is used. Here, we aimed to design and synthesize a novel core-shell structure comprising an amorphous shell and a crystalline core in order to overcome the material size limit imposed by the cooling rate effects. Our results show that the core-shell structure of Mg-based BMG does have a lower degradation rate and can maintain a more amorphous structure after six weeks of degradation. Moreover, the biocompatibility and osteogenic effects were similar between the core-shell and solid structures of Mg-based BMG. In conclusion, the core-shell structure of Mg-based BMG exhibits a lower degradation rate while still enhancing osteogenic potential in vitro. This core-shell structure of Mg-based BMG overcomes the cooling rate effects and provides a new structure for manufacturing Mg-based BMG.

Intermittent Parathyroid Hormone Injection Can Decrease Femoral Head Collapse in the Vascular Deprivation of Rat Femoral Head Model.

BACKGROUNDS: Intermittent parathyroid hormone (intermittent PTH) injection has been shown to improve osteogenesis. We hypothesized that intermittent PTH injection could stimulate osteogenesis during the early phase of vascular deprivation-induced femoral neck osteonecrosis in a rat model. MATERIALS AND METHODS: Eighteen Sprague-Dawley rats were divided into three groups (normal saline [CON], PTH 10 µg/kg [PTH-H], and PTH 1 µg/kg [PTH-L]) for 8 weeks by subcutaneous injection. All rats were sacrificed at postoperative 8 weeks, and all underwent a micro-computed tomography (µ-CT) examination for bone quality and quantity evaluation and histomorphometric analysis for microscopic histologic differences. RESULTS: Under µ-CT examination, both the PTH-H and PTH-L groups revealed less bone resorption than the control group. The PTH-H group had a better bone protective effect than the PTH-L group. Bone mineral density was increased in the PTH-H and PTH-L groups compared to the control group. The uninjured left femoral head was enlarged in both PTH groups. The histologic examination showed that both PTH groups had new bone and cartilage formation. The control group had only dead bone without any osteogenesis. CONCLUSION: Intermittent PTH injection could decrease bone resorption and improve bone density, compared to the control group, in vascular deprivation of the femoral head in a rat model. High-level intermittent PTH injection had a better effect than low-level intermittent PTH injection.

Biofunctional core-shell polypyrrole-polyethylenimine nanocomplex for a locally sustained photothermal with reactive oxygen species enhanced therapeutic effect against lung cancer.

BACKGROUND: Polymeric delivery systems have been elucidated over the last few years as an approach of achieving high therapeutic effect to the local site of malignant disease patients who have cancer. Polypyrrole (Ppy) is a potential organic conducting polymer which has long been recognized as a versatile material due to its excellent stability, conductive properties, and great absorbance in the range of near-infrared (NIR). It is tremendously versatile for use in various biomedical fields such as cancer therapy. NIR irradiation-activated treatment platform technologies are now being considered to be novel and exciting options in potential nanomedicine. However, the realistic photothermal use of Ppy-applied nanomaterials is yet in its early phase, and there are a few disadvantages of Ppy, such as its water insolubility. In the clinic, the common approach for treatment of lung cancer is the delivery of therapeutic active substances through intratumoral administration. Nevertheless, the tumor uptake, regional retention, mechanism of treatment, and tissue organ penetration regarding the developed strategy of this nanomaterial with photothermal hyperthermia are important issues for exerting effective cancer therapy. MATERIALS AND METHODS: In this study, we developed a cationic Ppy-polyethylenimine nanocomplex (NC) with photothermal hyperthermia to study its physicochemical characteristics, including size distribution, zeta potential, and transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared morphology. We also examined the cellular uptake effect on lung cancer cells, the photothermal properties, intracellularly generated reactive oxygen species (ROS), and cytotoxicity. RESULTS: The results suggested that this nanocarrier system was able to effectively attach onto lung cancer cells for subsequent endocytosis. The NCs taken up were able to absorb NIR and then converted the NIR light into local hyperthermia with its intracellular photothermal performance to provide local hyperthermic treatment. This regionally generated hyperthermia also induced ROS formation and improved the killing of lung cancer cells as a promising local photothermal therapy. CONCLUSION: This development of a nanocarrier would bring a novel therapeutic strategy for lung cancer in the future.

A Gelatin Hydrogel-Containing Nano-Organic PEI⁻Ppy with a Photothermal Responsive Effect for Tissue Engineering Applications.

The introduction and designing of functional thermoresponsive hydrogels have been recommended as recent potential therapeutic approaches for biomedical applications. The development of bioactive materials such as thermosensitive gelatin-incorporated nano-organic materials with a porous structure and photothermally triggerable and cell adhesion properties may potentially achieve this goal. This novel class of photothermal hydrogels can provide an advantage of hyperthermia together with a reversibly transformable hydrogel for tissue engineering. Polypyrrole (Ppy) is a bioorganic conducting polymeric substance and has long been used in biomedical applications owing to its brilliant stability, electrically conductive features, and excellent absorbance around the near-infrared (NIR) region. In this study, a cationic photothermal triggerable/guidable gelatin hydrogel containing a polyethylenimine (PEI)⁻Ppy nanocomplex with a porous microstructure was established, and its physicochemical characteristics were studied through dynamic light scattering, scanning electronic microscopy, transmission electron microscopy, an FTIR; and cellular interaction behaviors towards fibroblasts incubated with a test sample were examined via MTT assay and fluorescence microscopy. Photothermal performance was evaluated. Furthermore, the in vivo study was performed on male Wistar rat full thickness excisions model for checking the safety and efficacy of the designed gelatin⁻PEI⁻Ppy nanohydrogel system in wound healing and for other biomedical uses in future. This photothermally sensitive hydrogel system has an NIR-triggerable property that provides local hyperthermic temperature by PEI⁻Ppy nanoparticles for tissue engineering applications. Features of the designed hydrogel may fill other niches, such as being an antibacterial agent, generation of free radicals to further improve wound healing, and remodeling of the promising photothermal therapy for future tissue engineering applications.

Genipin-crosslinked adipose stem cell derived extracellular matrix-nano graphene oxide composite sponge for skin tissue engineering.

Autologous skin grafts, which can cause donor site morbidity, are currently used to treat deep wounds. To improve the regeneration of poorly healing wounds, cell-derived extracellular matrix (ECM) scaffolds are garnering great research interest due to their associated lower risks of pathogen transfer and immune rejection. However, the mechanical properties of cell-derived ECM scaffolds are inferior when compared to those of tissue-derived ECM scaffolds. To overcome this drawback, different amounts (10, 20, 50, and 100 µg mL-1) of graphene oxide (GO) and genipin (1% w/v) were applied to adipose stem cell (ASC)-derived ECM sponges. There are still only a few studies employing cell-derived extracellular matrices as biomimetic scaffolds for biomedical applications. The aim of our study was to develop biocompatible, biodegradable, low immunogenic, and genipin-crosslinked ASC-derived ECM sponges containing a suitable amount of GO for skin-tissue engineering. Sponges were fabricated using cultures of ASCs, cell sheets, and decellularization of an ASC cell sheet, freeze-thawing, and crosslinking in a sequential manner. Scanning electron microscopic analyses of the sponges demonstrated a highly porous microstructure with a pore size of 71.22 ± 19.52 µm. The in vitro degradation rate was found to be significantly higher in the non-crosslinked ECM sponges and pure ECM sponges than in the genipin-crosslinked ECM sponges. During an in vivo study, we investigated the material feasibilities and degradability of the constructed ECM sponges as a suitable skin tissue-engineering scaffold in a xenogenic animal (rat) model for 4 weeks. After subcutaneous implantation, the ECM sponges containing a medium amount of GO showed appropriate biodegradation with a lower inflammatory reaction. Hence, the fabricated ECM sponges might be a suitable xenogenous skin substitute for full-thickness skin defects and in other future soft-tissue engineering applications, such as healing partial tears of the anterior cruciate ligament.

Prediction of biochemical oxygen demand at the upstream catchment of a reservoir using adaptive neuro fuzzy inference system.

The aim of this study is to examine the potential of adaptive neuro fuzzy inference system (ANFIS) to estimate biochemical oxygen demand (BOD). To illustrate the applicability of ANFIS method, the upstream catchment of Feitsui Reservoir in Taiwan is chosen as the case study area. The appropriate input variables used to develop the ANFIS models are determined based on the t-test. The results obtained by ANFIS are compared with those by multiple linear regression (MLR) and artificial neural networks (ANNs). Simulated results show that the identified ANFIS model is superior to the traditional MLR and nonlinear ANNs models in terms of the performance evaluated by the Pearson coefficient of correlation, the root mean square error, the mean absolute percentage, and the mean absolute error. These results indicate that ANFIS models are more suitable than ANNs or MLR models to predict the nonlinear relationship within the variables caused by the complexity of aquatic systems and to produce the best fit of the measured BOD concentrations. ANFIS can be seen as a powerful predictive alternative to traditional water quality modeling techniques and extended to other areas to improve the understanding of river pollution trends.

Rapid and sensitive detection of carbapenemase activity in Acinetobacter baumannii using superficially porous liquid chromatography-tandem mass spectrometry.

BACKGROUND: The emergence and spread of carbapenem-resistant Acinetobacter baumannii poses a challenge for optimizing antibiotic therapies and preventing outbreaks. Traditional phenotypic assays such as the modified Hodge test (MHT) or polymerase chain reaction (PCR)-based detection of the carbapenemase genes are time-consuming and complicated. Therefore, new approaches for the efficient detection of carbapenemase-producing A. baumannii are urgently required. METHODS: In this study, we used the superficially porous liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay to measure carbapenem hydrolysis in a solution spiked with test strains of A. baumannii. The rate of carbapenem hydrolysis during incubation was expressed as the ratio of the carbapenem peak area of the test A. baumannii strains to the noncarbapenemase-producing A. baumannii ATCC 17978. This method can accurately measure the carbapenem hydrolysis rate and, therefore, can effectively identify carbapenemase-producing strains within 75 minutes. RESULTS: A total of 112 A. baumannii strains were used in this study, including 103 clinical isolates with 68 carbapenem-resistant strains and 35 carbapenem-susceptible strains, seven ATCC strains and two selected mutants. The results of the superficially porous LC-MS/MS assay showed higher detection sensitivity compared to the results of the MHT. CONCLUSION: Our results demonstrate the ability of the former method to routinely detect carbapenemase-producing A. baumannii.

Evaluating Osteogenic Potential of Ligamentum Flavum Cells Cultivated in Photoresponsive Hydrogel that Incorporates Bone Morphogenetic Protein-2 for Spinal Fusion.

Regenerative medicine is increasingly important in clinical practice. Ligamentum flava (LF) are typically removed during spine-related surgeries. LF may be a source of cells for spinal fusion that is conducted using tissue engineering techniques. In this investigation, LF cells of rabbits were isolated and then characterized by flow cytometry, morphological observation, and immunofluorescence staining. The LF cells were also cultivated in polyethylene (glycol) diacrylate (PEGDA) hydrogels that incorporated bone morphogenetic protein-2 (BMP-2) growth factor, to evaluate their proliferation and secretion of ECM and differentiation in vitro. The experimental results thus obtained that the proliferation, ECM secretion, and differentiation of the PEGDA-BMP-2 group exceeded those of the PEGDA group during the period of cultivation. The mineralization and histological staining results differed similarly. A nude mice model was utilized to prove that LF cells on hydrogels could undergo osteogenic differentiation in vivo. These experimental results also revealed that the PEGDA-BMP-2 group had better osteogenic effects than the PEGDA group following a 12 weeks after transplantation. According to all of these experimental results, LF cells are a source of cells for spinal fusion and PEGDA-BMP-2 hydrogel is a candidate biomaterial for spinal fusion by tissue engineering.

Differentiation Effects of Platelet-Rich Plasma Concentrations on Synovial Fluid Mesenchymal Stem Cells from Pigs Cultivated in Alginate Complex Hydrogel.

This article studied the effects of platelet-rich plasma (PRP) on the potential of synovial fluid mesenchymal stem cells (SF-MSCs) to differentiate. The PRP and SF-MSCs were obtained from the blood and knees of pigs, respectively. The identification of SF-MSCs and their ability to differentiate were studied by histological and surface epitopes, respectively. The SF-MSCs can undergo trilineage mesenchymal differentiation under osteogenic, chondrogenic, and adipocyte induction. The effects of various PRP concentrations (0%, 20% and 50% PRP) on differentiation were evaluated using the SF-MSCs-alginate system, such as gene expression and DNA proliferation. A 50% PRP concentration yielded better differentiation than the 20% PRP concentration. PRP favored the chondrogenesis of SF-MSCs over their osteogenesis in a manner that depended on the ratios of type II collagen/type I collagen and aggrecan/osteopontin. Eventually, PRP promoted the proliferation of SF-MSCs and induced chondrogenic differentiation of SF-MSCs in vitro. Both PRP and SF-MSCs could be feasibly used in regenerative medicine and orthopedic surgeries.

Sustainable hydrogen production by ethanol steam reforming using a partially reduced copper-nickel oxide catalyst.

Hydrogen production through the use of renewable raw materials and renewable energy is crucial for advancing its applications as an energy carrier. In this study, we fabricated a solid oxide solution of Cu and Ni within a confined pore space, followed by a partial reduction, to produce a highly efficient catalyst for ethanol steam reforming (ESR). At 300 °C, EtOH is completely converted, a H2 yield of approximately 5 mol per mol is achieved, and CO2 is the main carbon-containing product. This demonstrates that H2 production from bioethanol is an efficient and sustainable approach. Such a highly efficient ESR catalyst is attributed to the ability of the metal-oxide interface to facilitate the transformation of CHx adspecies from acetaldehyde decomposition into methoxy-like adspecies, which are reformed readily to produce H2 and consequently reduce CH4 formation.

Shoulder hemiarthroplasty for proximal humeral fractures: comparisons between the deltopectoral and anterolateral deltoid-splitting approaches.

BACKGROUND: Shoulder hemiarthroplasty is a widely accepted method for treating complex proximal humeral fractures, and the deltopectoral approach is the most popular route for this procedure. The purpose of the current study was to define and compare outcomes of shoulder hemiarthroplasty when using deltopectoral or anterolateral deltoid-splitting approaches. MATERIALS AND METHODS: Two cohorts of patients were compared for clinical and radiographic outcomes at the same postoperative follow-up periods: a deltopectoral group (DP group) of 15 patients, from November 2004 to April 2007, and an anterolateral deltoid-splitting group (DS group) of 17 patients, from May 2007 to December 2009. Pain scores, goniometric measurements of the range of motion, and Constant scores were recorded for clinical assessment. Radiographic evaluations were recorded for stem osteolysis, tuberosity absorption, joint subluxation, and acromiohumeral distance. RESULTS: The 2 groups did not differ significantly in demographic data, preoperative fracture classification, surgical timing, early postoperative radiographic findings, and 2-year radiographic results. The DS group had less immediate postoperative pain (P = .025). At the 2-year follow-up assessment, the groups did not difference significantly in shoulder abduction and forward flexion. All prostheses survived until the 2-year assessment. CONCLUSION: When performing shoulder hemiarthroplasty for complex proximal humeral fractures, we found that the anterolateral deltoid-splitting approach provides an easier route for assessing posterior fracture fragments and managing rotator cuff tissue. The anterolateral deltoid-splitting approach was shown to be an acceptable alternative route for shoulder hemiarthroplasty than the standard deltopectoral approach.

Clinical results of all-inside meniscal repair using the FasT-Fix meniscal repair system.

BACKGROUND: The meniscus plays a key role in the functioning of the knee. At the present time, meniscal repair has becomes the main treatment for meniscal tear. Compared to open surgery, arthroscopic meniscal repair has become popular because of shorter time need for the operation, the smaller wound, and better accessibility to the tear portion, which is particularly difficult during open surgery. Three arthroscopic techniques are widely used, namely inside-out, outside-in, and all-inside. Arthroscopy all inside meniscal repair has the lowest neurovascular injury rate. METHODS: This study prospectively evaluated 31 consecutively treated patients to determine the effectiveness/safety of arthroscopic meniscal repair using the FasTFix repair system. The inclusion criteria for this study were: vertical fullthickness tear> 10 mm in length; location of the meniscal tear < 6 mm from the meniscocapsular junction; repair of the meniscus solely with the FasTFix system; no former meniscus surgery; and no evidence of arthritis during arthroscopy. Anterior cruciate ligament (ACL) deficient knees were reconstructed using a hamstring autograft at the time of the meniscal repair. Follow-up examinations consisted of Lysholm knee score, Tegner activity score and radiographic evaluation. RESULTS: After an average of 3 years follow-up, no symptoms of meniscal tears were found in 30/31 of the cases. For patients with isolated meniscal repair or concurrent ACL reconstruction, the Lysholm and Tegner activity scores had significantly improved postoperatively. No neurovascular or other major complications were directly associated with the use of the device. CONCLUSIONS: Arthroscopic all-inside repair using the FasT-Fix device appears to be a safe and effective procedure.

Cost feasibility of a pre-checking medical tourism system for U.S. patients undertaking joint replacement surgery in Taiwan.

BACKGROUND: Medical tourism is a relatively recent global economic and political phenomenon that has assumed increasing importance for developing countries, particularly in Asia. In fact, Taiwan possesses a niche for developing medical tourism because many hospitals provide state-of-the-art medicine in all disciplines and many doctors are trained in the United States (US). Among the most common medical procedures outsourced, joint replacements such as total knee replacement (TKR) and total hip replacement (THR) are two surgeries offered to US patients at a lower cost and shorter waiting time than in the US. METHODS: This paper proposed a pre-checking medical tourism system (PCMTS) and evaluated the cost feasibility of recruiting American clients traveling to Taiwan for joint replacement surgery. Cost analysis was used to estimate the prime costs for each stage in the proposed PCMTS. Sensitivity analysis was implemented to examine how different pricings for medical checking and a surgical operation (MC&SO) and recovery, can influence the surplus per patient considering the PCMTS. Finally, the break-even method was adopted to test the tradeoff between the sunk costs of investment in the PCMTS and the annual surplus for participating hospitals. RESULTS: A novel business plan was built showing that pre-checking stations in medical tourism can provide post-operative care and recovery follow-up. Adjustable pricing for hospital administrators engaged in the PCMTS consisted of two main costs: US$3,700 for MC&SO and US$120 for the hospital stay. Guidelines for pricing were provided to maximize the annual surplus from this plan with different number of patients participating in PCMTS. The maximal profit margin from each American patient undertaking joint surgery is about US$24,315. CONCLUSIONS: Using cost analysis, this article might be the first to evaluate the feasibility of PCMTS for joint replacement surgeries. The research framework in this article is applicable when hospital administrators evaluate the feasibility of outsourced medical procedures other than TKR and THR.

Lidar ratio and depolarization ratio for cirrus clouds.

We report on studies of the lidar and the depolarization ratios for cirrus clouds. The optical depth and effective lidar ratio are derived from the transmission of clouds, which is determined by comparing the backscattering signals at the cloud base and cloud top. The lidar signals were fitted to a background atmospheric density profile outside the cloud region to warrant the linear response of the return signals with the scattering media. An average lidar ratio, 29 +/- 12 sr, has been found for all clouds measured in 1999 and 2000. The height and temperature dependences ofthe lidar ratio, the optical depth, and the depolarization ratio were investigated and compared with results of LITE and PROBE. Cirrus clouds detected near the tropopause are usually optically thin and mostly subvisual. Clouds with the largest optical depths were found near 12 km with a temperature of approximately -55 degrees C. The multiple-scattering effect is considered for clouds with high optical depths, and this effect lowers the lidar ratios compared with a single-scattering condition. Lidar ratios are in the 20-40 range for clouds at heights of 12.5-15 km and are smaller than approximately 30 in height above 15 km. Clouds are usually optically thin for temperatures below approximately -65 degrees C, and in this region the optical depth tends to decrease with height. The depolarization ratio is found to increase with a height at 11-15 km and smaller than 0.3 above 16 km. The variation in the depolarization ratio with the lidar ratio was also reported. The lidar and depolarization ratios were discussed in terms of the types of hexagonal ice crystals.