Response of microbial communities and biogeochemical cycling functions to sediment physicochemical properties and microplastic pollution under damming and water diversion projects.

Understanding the interactions among flow-sediment, microorganisms, and biogeochemical cycles is crucial for comprehending the ecological response mechanisms of dams and water diversion. This study focused on the spatial patterns of carbon, nitrogen, phosphorus, and sulfur (CNPS) cycle functional genes in the water resource for the middle route of the South-to-North Water Diversion Project in China, specifically the Danjiangkou Reservoir (comprising the Han and Dan reservoirs). The investigation incorporated sediment physicochemical properties and microplastic pollution. Numerous microbial species were identified, revealing that microbial communities demonstrated sensitivity to changes in sedimentary mud content. The communities exhibited greater ß diversity due to finer sediment particles in the Han Reservoir (HR), whereas in the Dan Reservoir (DR), despite having higher sediment nutrient content and MPs pollution, did not display this pattern. Regarding the composition and structure of microbial communities, the study highlighted that sediment N and P content had a more significant influence compared to particle size and MPs. The quantitative microbial element cycling (QMEC) results confirmed the presence of extensive chemolithotrophic microbes and strong nitrogen cycle activity stemming from long-term water storage and diversion operations. The denitrification intensity in the HR surpassed that of the DR. Notably, near the pre-dam area, biological nitrogen fixation, phosphorus removal, and sulfur reduction exhibited noticeable increases. Dam construction refined sediment, fostering the growth of different biogeochemical cycling bacteria and increasing the abundance of CNPS cycling genes. Furthermore, the presence of MPs exhibited a positive correlation with S cycling genes and a negative correlation with C and N cycling genes. These findings suggest that variations in flow-sediment dynamics and MPs pollution have significant impact the biogeochemical cycle of the reservoir.

Process Optimization, Structural Characterization, and Calcium Release Rate Evaluation of Mung Bean Peptides-Calcium Chelate.

To reduce grievous ecological environment pollution and protein resource waste during mung bean starch production, mung bean peptides-calcium chelate (MBP-Ca) was synthesized as a novel and efficient calcium supplement. Under the optimal conditions (pH = 6, temperature = 45 °C, mass ratio of mung bean peptides (MBP)/CaCl2 = 4:1, MBP concentration = 20 mg/mL, time = 60 min), the obtained MBP-Ca achieved a calcium chelating rate of 86.26%. MBP-Ca, different from MBP, was a new compound rich in glutamic acid (32.74%) and aspartic acid (15.10%). Calcium ions could bind to MBP mainly through carboxyl oxygen, carbonyl oxygen, and amino nitrogen atoms to form MBP-Ca. Calcium ions-induced intra- and intermolecular interactions caused the folding and aggregation of MBP. After the chelation reaction between calcium ions and MBP, the percentage of ß-sheet in the secondary structure of MBP increased by 1.90%, the size of the peptides increased by 124.42 nm, and the dense and smooth surface structure of MBP was transformed into fragmented and coarse blocks. Under different temperatures, pH, and gastrointestinal simulated digestion conditions, MBP-Ca exhibited an increased calcium release rate compared with the conventional calcium supplement CaCl2. Overall, MBP-Ca showed promise as an alternative dietary calcium supplement with good calcium absorption and bioavailability.

Effects of platelet-rich plasma on subchondral bone marrow edema and biomarkers in synovial fluid of knee osteoarthritis.

BACKGROUND: The aim of the study was to investigate the effect of platelet-rich plasma (PRP) on subchondral bone marrow edema (BME) and the level of biomarkers in synovial fluid of the knee osteoarthritis. METHODS: Eighty-one patients with symptomatic knee osteoarthritis were randomly divided into two groups according to the number of inpatients. Forty-five cases were treated with intra-articular injection of PRP (PRP group), 36 cases were treated with sodium hyaluronate (SH group), and the clinical effects were evaluated using the Visual Analogue Scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores. The changes of subchondral BME were assessed by magnetic resonance imaging (MRI) before and after treatment. The levels of TNFα, IL-6, MCP-1, MMP-1, MMP-3, and MMP-9 in synovial fluid were also detected. RESULTS: All the patients completed the corresponding treatment and were followed up for 12 months without serious complications. After the treatment, the VAS and WOMAC scores of the two groups were significantly decreased, and the difference was statistically significant at different time points (P < 0.05). The VAS and WOMAC scores of the PRP group were better than those of the SH group (P < 0.05). MRI showed that the subchondral bone edema of the two groups were reduced in varying degrees, and the reduction was more noticeable in the PRP group (P < 0.05). The levels of TNFα, IL-6, MCP-1, MMP-1, MMP-3, and MMP-9 in two groups were decreased, and the difference was statistically significant at different time points (P < 0.05). However, the levels of TNFα, IL-6, MCP-1, MMP-1, MMP-3, and MMP-9 in the PRP group were significantly lower than those in the SH group (P < 0.05). CONCLUSIONS: Intra-articular injection of PRP can significantly reduce the subchondral BME and the level of biomarkers in synovial fluid of the symptomatic knee osteoarthritis.

Distribution of antibiotic resistance genes in the sediments of Erhai Lake, Yunnan-Kweichow Plateau, China: Their linear relations with nonpoint source pollution discharges from 26 tributaries.

Erhai Lake, a typical plateau deep water lake, experienced long-term nonpoint source (NPS) pollution discharge from 26 tributaries, which significantly affected the abundance and spread of resistance genes. In this study, 25 antibiotic resistance genes (ARGs), classified into six types, and NPS pollution discharges were investigated throughout around the Erhai basin. FCA (mexF) and sulfonamide resistance genes (sul1, sul2 and sul3) were the most common. Although the absolute overall abundance of ARGs there was low so far, the individual gene like sulfonamide resistance gene was high. Regression analysis using an ordinary least squares model (OLS) showed that the discharge of NPS pollution into Erhai Lake would have an obvious effect on the distribution of ARGs. And the relations between them were linear. Concretely speaking, the total nitrogen (TN) pollution input from tributaries could significantly correlated with the increasing of ARG abundance, while the total phosphorus (TP) pollution input showed the opposite correlation, and ultimately affect the distribution of ARGs. Moreover, the effect of TP on ARG distribution was more significant than TN. This study provides a geographical profile of ARG distribution in a subtropical deep lake on Yunnan-Kweichow Plateau. The results are beneficial for predicting the distribution characteristics of ARGs and controlling their pollution in plateau lakes.

PRP from Personal Blood Relieves Joint Fluid-Inducing Synovial Injury through NF-κB Pathway and Mitochondrial Apoptosis in Human Synovial Fibroblast Cells.

Background: Platelet-rich plasma (PRP) therapy is a new kind of biological therapy to retune the plasma concentrator into the patient's body for the treatment of osteoarthritis diseases. The present research aimsed to confirm the treatment effects of PRP against osteoarthritis injury and elucidate its potential mechanism via constructing a kind of cellular injury model of human synovial fibroblast cells (HSF cells) induced by synovial fluid from osteoarthritis patients. Materials and Methods: HSF cells wereas firstly treated with the different doses of synovial fluid from osteoarthritis patients, and evaluated for the cellular injury via cell morphology and MTT assay. And then, the protective effect of PRP against cellular injury were examined by cell morphology and MTT assay. Following, flow cytometry and western blot assay were employed to evaluate the effect of PRP on mitochondrial apoptosis. Finally, the effect of PRP on NF-κB pathway-associated inflammation wasere examined by Elisa ELISA assay and western blot. Results: The dilution ratio 1 : 5 of synovial fluid displayed an excellent injury effect against HSF cells and selected as the model condition. The data from cellular image and MTT assay showed that PRP with the doses 1 : 5 and 1 : 10 could alleviate the cellular mounts decrease in the damaged HSF cells. Flow cytometry, western blot, and Elisa ELISA assay displayed that PRP could relieve the cellular mitochondrial apoptosis and NF-κB pathway-associated inflammation in the damaged HSF cells. Conclusion: PRP might relieve HSF cells injury induced by synovial fluid from osteoarthritis patients through alleviating the mitochondrial apoptosis and NF-κB pathway-associated inflammation.

Dynamics of Detection of Anti-SARS-CoV-2 IgG/IgM and SARS-CoV-2 RNA in Respiratory Tract Specimens in 48 COVID-19 Patients.

BACKGROUND: The rapid spread of pneumonia caused by SARS-CoV-2 has seriously threatened people. In this study, we detected the expression of anti-SARS-CoV-2 IgG/IgM and respiratory tract SARS-CoV-2 RNA in patients with COVID-19 and explored the correlation and clinical significance between SARS-CoV-2 antibody and respiratory SARS-CoV-2 RNA. METHODS: From March 5, 2020 to April 28, 2020, 48 cases with COVID-19 diagnosed in Beijing Xiaotangshan Hospital were enrolled. SARS-CoV-2 RNAs were detected by real-time fluorescence RT-PCR method. Serum SARS-CoV-2 IgG/IgM antibodies were determined by colloidal gold immunochromatography. The statistical analysis was performed using chi-squared test. RESULTS: In all the patients, SARS-CoV-2 RNA among 270 upper respiratory tract (nasal or throat swabs) samples, 71 lower respiratory tract (sputum) samples, and anti-SARS-CoV-2 IgM/IgG antibodies in 123 serum samples were detected during the hospitalization period. The positive rate of anti-SARS-CoV-2 IgG was significantly higher than that of anti-SARS-CoV-2 IgM within the first week after symptom onset (p < 0.05). The positive rate of anti-SARS-CoV-2 IgG was also significantly higher than that of anti-SARS-CoV-2 IgM during day 8 - 30 after symptom onset (p < 0.01). The positive rate of SARS-CoV-2 RNA in the lower respiratory tract specimens (64.8%, 46/71) was significantly higher than that in the upper respiratory tract (46.7%, 126/270) (p < 0.05). The positive rate (100%, 4/4) of SARS-CoV-2 RNA detection in the lower respiratory tract specimens before IgG seroconversion was significantly higher than that of the positive rate (59.3%, 32/54) after IgG seroconversion (p < 0.01). The positive rate (72.2%, 57/79) of SARS-CoV-2 RNA detection in the upper respiratory tract specimens before IgG seroconversion was significantly higher than that of the positive rate (30.7%, 39/127) after IgG seroconversion (p < 0.01). CONCLUSIONS: Anti-SARS-CoV-2 IgG might be detected within the first week after symptom onset. The application of SARS-CoV-2 antibody (IgG/IgM) detection is important for the suspected cases of SARS-CoV-2 infection with negative SARS-CoV-2 RNA results. The positive rate of SARS-CoV-2 RNA detection in the lower respiratory tract specimens was significantly higher than that in the upper respiratory tract. Sputum detection is recommended for the detection of SARS-CoV-2 RNA. Using lower respiratory tract specimens may reduce the false negative PCR tests. The detection of SARS-CoV-2 RNA can be improved by investigating follow-up specimens over time.

Moderate vs. mild cases of overseas-imported COVID-19 in Beijing: a retrospective cohort study.

This study compared the differences in the clinical manifestations, treatment courses and clinical turnover between mild and moderate coronavirus disease 2019 (COVID-19). Clinical data of the patients with imported COVID-19 admitted to Beijing Xiaotangshan Designated Hospital between March 15 and April 30, 2020, were retrospectively analysed. A total of 53 COVID-19 patients were included, with 21 mild and 32 moderate cases. Compared with the mild group, the moderate group showed significant differences in breathing frequency, lymphocyte count, neutrophil percentage, neutrophil/lymphocyte ratio, procalcitonin, C-reactive protein, and dynamic erythrocyte sedimentation rate. In the moderate group, 87.5% exhibited ground-glass opacities, 14% exhibited consolidative opacities, 53.1% exhibited local lesions and 68.8% exhibited unilateral lesions. The proportion of patients who received antiviral or antibiotic treatment in the moderate group was higher than that in the mild group, and the number of cases that progressed to severe disease in the moderate group was also significantly higher (18.7% vs. 0%, p = 0.035). Compared with patients with mild COVID-19, those with moderate COVID-19 exhibited more noticeable inflammatory reactions, more severe pulmonary imaging manifestations and earlier expression of protective antibodies. The overall turnover of the moderate cases was poorer than that of the mild cases.

[Composition and Distribution Characteristics of Microplastics in Danjiangkou Reservoir and Its Tributaries].

Microplastic pollution is a hot topic in environmental science. To explore the microplastics in Danjiangkou Reservoir, a national first-class water source protection area, we studied their types, abundance, and material characteristics using density flotation and micro-Raman spectroscopy. The spatial distribution characteristics of microplastics were also revealed according to the hydrologic and hydrodynamic conditions of the reservoir. The results showed that the main types of microplastics were fragments (84.2% of the total), granules, films, and fibers, of which 84.2% were fragments. The numbers of each type of microplastic were significantly different in different areas. A variety of colors were observed, with transparent and brown microplastic being most common. During the wet season, the average abundance of microplastics in the reservoir was 7248 n·m-3, which is higher than that observed in the Han Reservoir. The particle sizes of the microplastics in the research area ranged 75-4703 µm, of which 73.4% had a particle size of less than 500 µm; microplastic abundance was inversely related to particle size. Nylon was the most common form of microplastic in Danjiangkou Reservoir, accounting for 36.4% of the total, followed by polyethylene (PE) and polypropylene (PP).

Distribution and source of microplastics in China's second largest reservoir - Danjiangkou Reservoir.

Fresh water microplastic pollution is of pressing concern globally, but its distribution and sources in reservoirs are poorly documented. Danjiangkou Reservoir is the second largest reservoir in China and is divided into the Han Reservoir and Dan Reservoir. In this work, microplastic abundances and morphological characteristics of the reservoir were investigated. The microplastic abundance of 15 main tributaries of the reservoir was also measured. The vertical distribution (in water column and sediment), horizontal distribution (in Han Reservoir and Dan Reservoir) and source of microplastics were analyzed. Microplastics accumulated in the middle layer of the reservoir, and the size and color of the microplastic particles changed from the surface to the bottom, which implies that surveys of surface water are not enough to determine the microplastic contamination for deep water reservoirs. In the surface water, the microplastic abundance in the Han Reservoir was lower than that in the Dan Reservoir (p < 0.05), but microplastic abundance did not differ significantly in the intermediate and bottom water. Tributaries were one of the main sources of microplastics for Han Reservoir but not for Dan Reservoir. Agricultural cultivation in the hydro-fluctuation belt might be an important source of microplastics in the Dan Reservoir, which should be given additional attention. The results of this study can provide valuable information for developing microplastic sampling strategies in deep water reservoirs. Further studies are recommended to investigate the process through which microplastics in the hydro-fluctuation belt enter the reservoir and the sinking behavior of microplastics in the reservoir.

Tears of the Popliteomeniscal Fascicles of the Lateral Meniscus: An Arthroscopic Classification.

OBJECTIVE: To bring forward an arthroscopic classification of the popliteomeniscal fascicles of the lateral meniscus (PFLM) tears. DESIGN: Six fresh frozen knee joint samples of adult males were chosen, and the lateral meniscus at the popliteal hiatus region were measured to analyze their anatomic relationship. Patients who had received magnetic resonance imaging scan at knee joint before the surgery and diagnosed as PFLM tears by arthroscopy from April 2014 to October 2017 were selected. Data regarding the integrity of PFLM were prospectively recorded in a data registry. Tear morphology and treatment received were subsequently extracted by 2 independent reviewers from operative notes and arthroscopic surgical photos. RESULTS: The average length and thickness of the popliteal hiatus of the lateral meniscus were 2.09 ± 0.21 cm and 0.43 ± 0.08 cm, respectively. The average length of anterosuperior popliteomeniscal fascicle (APF) was 0.87 ± 0.18 cm, and the posterosuperior popliteomeniscal fascicle (PPF) was 0.72 ± 0.15 cm. A total of 36 PFLM tears in 36 patients were divided as type I (APF tear; n = 5, 13.9%), type II (PPF tear; n = 20, 55.6%), and type III (both APF and PPF tears; n = 11, 30.6%). All patients were treated with arthroscopic all-inside repair using a suture hook for the PFLM tears and follow-up for 21.1 months. All patients have done well with significantly improved Lysholm and International Knee Documentation Committee scores at the last follow-up relative to preoperative scores (P < 0.01). CONCLUSION: This study suggests to possibly classify the PFLM tears for clinical practice.

Comparison of the clinical manifestations between different age groups of patients with overseas imported COVID-19.

The current study investigated the clinical manifestations and outcomes of different age groups of patients with overseas imported COVID-19. In total, 53 COVID-19 patients admitted to the designated Beijing Xiaotangshan Hospital between March 16 and April 15 of 2020 were included. Based on the percentage of disease aggravation during hospital stay according to CT, the patients were divided into two groups: ≤40 years (group A; n = 41) and >40 years (group B; n = 12). The demographic data, epidemiological history, disease courses, potential complications, clinical symptoms, lab indices, chest CT outcomes, treatment protocols and turnovers of the two groups were compared. According to clinical typing, compared with group A, group B had a significantly greater proportion of the common type of COVID-19 (P<0.05) and greater comorbidity of type 2 diabetes (P<0.001). The two groups presented significantly different lab indices. Group B showed significantly more frequent CT abnormalities, with greater proportions of multiple lesions and bilateral lung involvement (P<0.05). During hospitalization, group B had a greater proportion of disease aggravation according to CT (P<0.01). Compared with group A, group B received a significantly greater proportion of antiviral therapy and presented a significantly greater occurrence of adverse drug reactions (P<0.05). The two groups did not significantly differ in time from admission to clinical symptom improvement or from disease onset to negative outcomes according to nucleic acid testing, the appearance of IgG or the appearance of IgM. They also did not significantly differ in length of stay. Older imported COVID-19 patients, particularly those with type 2 diabetes, showed a broader pulmonary extent and faster development of the disease, more severe pathogenetic conditions and a greater risk of developing a critically severe type. Increased attention should be given to this population in clinical practice.

Platelet-Rich Plasma-Incorporated Autologous Granular Bone Grafts Improve Outcomes of Post-Traumatic Osteonecrosis of the Femoral Head.

BACKGROUND: To investigate the effects of platelet-rich plasma (PRP)-incorporated autologous granular bone grafts for treatment in the precollapse stages (Association of Research Circulation Osseous stage II-III) of posttraumatic osteonecrosis of the femoral head. METHODS: A total of 46 patients were eligible and enrolled in the study. Twenty-four patients were treated with core decompression and PRP-incorporated autologous granular bone grafting (treatment group), and 22 patients were treated with core decompression and autologous granular bone grafting (control group). During a minimum follow-up duration of 36 months, X-ray and computed tomography were used to evaluate the radiological results, and the Harris hip score (HHS) and visual analog scale were chosen to assess the clinical results. RESULTS: Both the treatment and control groups had a significantly improved HHS (P < .001). The minimum clinically important difference for the HHS was reached in 91.7% of the treatment group and 68.2% of the control group (P < .05). The HHS and visual analog scale in the treatment group were significantly improved than that in the control group at the last follow-up (P < .05). Successful clinical and radiological results were achieved 87.5% and 79.2% in the treatment group compared with 59.1% and 50.0% in the control group (P < .05), respectively. The survival rates based on the requirement for further hip surgery as an endpoint were higher in the treatment group in comparison to those in the control group (P < .05). CONCLUSION: PRP-incorporated autologous granular bone grafting is a safe and effective procedure for treatment in the precollapse stages (Association of Research Circulation Osseous stage II-III) of posttraumatic osteonecrosis of the femoral head.

Novel Elastic Syndesmosis Hook Plate Fixation Versus Routine Screw Fixation for Syndesmosis Injury.

Unstable external-rotation type ankle fractures with concomitant syndesmosis injury commonly occur. Syndesmosis screw fixation has long been regarded as a reference standard treatment for syndesmosis injury. However, its complications and biomechanical disadvantages have become controversial; thus, we designed a novel elastic syndesmosis hook plate (ESHP) that combines the features of both rigidity and flexibility. The purpose of the present study was to introduce this new method and compare its clinical outcomes with those of routine screw fixation. We randomized 25 patients to the screw fixation group and ESHP group. The average follow-up period was 12 months. The clinical outcomes included malreduction or loss of reduction, overall complications, and function. During the follow-up period, 3 cases (25%) of malreduction were found in screw fixation group on postoperative computed tomography. In the ESHP group, only 1 patient (7.69%) had a narrowed anterior gap between the distal tibia and fibula. However, the difference in the malreduction rate between the 2 groups was not significant statistically (p = .32). The overall complication rate in the ESHP group was lower than that in the screw group, although no significant differences were found between the 2 groups. The mean visual analog scale scores in the ESHP and screw groups were 1.46 ± 1.33 and 2.42 ± 2.07, respectively. The average dorsiflexion range of motion in both groups was satisfactory (14.77° versus 12.83°; p = .16). However, a statistically significant difference was found in the plantarflexion range of motion between the 2 groups (p < .05). In addition, the ESHP group had an earlier time to return to work (p < .05). The ESHP fixation construct can stably fix syndesmosis, retain the physiologic micromotion function of the syndesmosis, and results in fewer complications compared with routine syndesmosis screw fixation for syndesmotic instability. In conclusion, our results have shown ESHP to be a viable method for treatment of syndesmosis instability.

A Special Tear Pattern of Anterior Horn of the Lateral Meniscus: Macerated Tear.

BACKGROUND: We describe a special, interesting phenomenon found in the anterior horn of the lateral meniscus (AHLM): most tear patterns in the AHLM are distinctive, with loose fibers in injured region and circumferential fiber bundles were separated. We name it as macerated tear. The goal of this study was to bring forward a new type of meniscal tear in the AHLM and investigate its clinical value. MATERIALS AND METHODS: AHLM tears underwent arthroscopic surgery from January 2012 to December 2014 were included. Data regarding the integrity of AHLM were prospectively recorded in a data registry. Tear morphology and treatment received were subsequently extracted by 2 independent reviewers from operative notes and arthroscopic surgical photos. RESULTS: A total of 60 AHLM tears in 60 patients (mean age 27.1 years) were grouped into horizontal tears (n = 15, 25%), vertical tears (n = 14, 23%), complex tears (n = 6, 10%), and macerated tears (n = 25, 42%). There were 6 patients with AHLM cysts in macerated tear group and one patient in vertical tear group. 60 patients were performed arthroscopic meniscus repairs and were followed-up with averaged 18.7 months. Each group had significant postoperative improvement in Lysholm and IKDC scores (p < 0.05). However, the macerated tear group showed least functional recovery of Lysholm and IKDC scores compared to other groups (p < 0.05). In addition, there were no differences in postoperative range of motion, return to work, or return to sport/other baseline activities between the four groups (p > 0.05). CONCLUSIONS: This study demonstrated that the macerated tear is common in the tear pattern of AHLM. However, feasibility of the treatment of this type of meniscal tear, especially the meniscus repairs still requires further study.

[Development of a New Type Elastic Syndesmosis Hook Plate].

OBJECTIVE: To design a kind of internal fixation device to treat the syndesmosis injury. METHODS: The elastic syndesmosis hook plate is made of medical stainless steel alloy, which is consisted of locking or common screw fixing hole of the tibial side for the head, tridentate fork like arc anatomical fibula side plate for the tail and serpentine elastic connecting body. By reduction of the joint of the lower tibia and fibula, the steel plate tail is fixed at the side of the fibula and the head is fixed at the side of the tibia for fixing the symphysis. RESULTS: The design of elastic syndesmosis hook plate is reasonable, and the operation is convenient. There is no need to penetrate the substantia ossea and the plate has elastic micro-movement feature, the problem of internal fixation breakage and loosening is avoid in huge degree, so it is safe and reliable. CONCLUSION: The elastic syndesmosis hook plate is a new type medical apparatus of internal fixation of the symphysis, which is worthy of clinical popularization and application.

Reconstruction of Traumatic Bone Defect With In Situ Implantation of Dropped Traumatic Segmental Bone Fragments.

This study was conducted to determine whether in situ implantation of a dropped traumatic segmental bone fragment is safe and whether the authors' method would reduce the incidence of infectious and related complications. The authors retrospectively reviewed 16 patients with open fractures, including 11 with Gustilo-Anderson type IIIA fractures and 5 with Gustilo-Anderson type IIIB fractures who had a dropped traumatic segmental bone fragment between January 2002 and January 2012. Mean patient age was 35.4 years (range, 19-47 years). There were 10 femurs and 6 tibias. Average postoperative follow-up was 26.8 months (range, 12-60 months). The dropped traumatic segmental bone fragments were cleaned with 3% hydrogen peroxide, placed in separate sterile cups, and soaked in 1% iodophor for 30 minutes. Initial treatment included surgical debridement, wound irrigation, in situ implantation of the dropped traumatic segmental bone fragment, and temporary external fixation. Approximately 4 to 8 weeks later, after successful reconstruction of the soft tissue envelope, minimally invasive plate osteosynthesis was performed. Mean duration of treatment was 8 weeks (range, 6-14 weeks). All patients had fracture union at final follow-up. Mean healing time was 21.8 weeks (range, 14-48 weeks). One patient did not achieve primary union and required bone grafting. One patient with a Gustilo-Anderson type IIIB fracture had deep infection and removal of the dropped traumatic segmental bone fragment and bone grafting. According to the Klemm and Börner classification, 11 patients had excellent results, 3 had good results, and 2 had poor results. With adequate soft tissue coverage, this method was acceptable for the management of open fractures with bone defects.

Anterior versus posterior approach for four-level cervical spondylotic myelopathy.

The purpose of this study was to compare the results of 2 surgical strategies for 4-level cervical spondylotic myelopathy: a hybrid procedure using anterior cervical diskectomy and fusion (ACDF) combined with segmental corpectomy versus posterior laminectomy and fixation. Between 2002 and 2010, fifty-one patients with consecutive 4-level cervical spondylotic myelopathy were treated surgically, with 27 patients undergoing the hybrid procedure and 24 undergoing posterior laminectomy and fixation. Radiologic data were compared between the 2 groups, including cervical curvature and cervical range of motion (ROM) in the sagittal plane. Pre- and postoperative neurological status was evaluated using the Japanese Orthopaedic Association (JOA) scoring system and the Nurick grading system. Mean ROM at last follow-up was not significantly different between the 2 groups (P>.05). In the hybrid group, mean JOA score and Nurick grade improved from 9.6±1.4 and 2.74±0.45 respectively, preoperatively, to 13.9±1.3 and 0.86±0.38 respectively, postoperatively. In the fixation group, mean JOA score and Nurick grade improved from 9.4±1.2 and 2.81±0.42 respectively, preoperatively, to 13.1±1.5 and 1.32±0.36 respectively, postoperatively. The JOA scores and Nurick grades at last follow-up were significantly different between the 2 groups (P<.05). In patients with preoperative cervical kyphosis, preoperative JOA score and Nurick grade were not significantly different between the 2 groups (P>.05); however, JOA scores and Nurick grades at last follow-up showed better improvement in the hybrid group than in the fixation group (P<.01). In patients with preoperative cervical lordosis, the preoperative and last follow-up JOA score and Nurick grade were not significantly different between the 2 groups (P>.05).

Results of a bone splint technique for the treatment of lower limb deformities in children with type I osteogenesis imperfecta.

BACKGROUND: Children with osteogenesis imperfecta (OI) can suffer from frequent fractures and limb deformities, resulting in impaired ambulation. Osteopenia and thin cortices complicate orthopedic treatment in this group. This study evaluates the clinical results of a bone splint technique for the treatment of lower limb deformities in children with type I OI. The technique consists of internal plating combined with cortical strut allograft fixation. MATERIALS AND METHODS: We prospectively followed nine children (five boys, four girls) with lower limb deformities due to type I OI, who had been treated with the bone splint technique (11 femurs, four tibias) between 2003 and 2006. The fracture healing time, deformity improvement, ambulation ability and complications were recorded to evaluate treatment effects. RESULTS: At the time of surgery the average age in our study was 7.7 years (range 5-12 years). The average length of followup was 69 months (range 60-84 months). All patients had good fracture healing with an average healing time of 14 weeks (range 12-16 weeks) and none experienced further fractures, deformity, or nonunion. The fixation remained stable throughout the procedure in all cases, with no evidence of loosening or breakage of screws and the deformity and mobility significantly improved after surgery. Of the two children confined to bed before surgery, one was able to walk on crutches and the other needed a wheelchair. The other seven patients could walk without walking aids or support like crutches. CONCLUSIONS: These findings suggest that the bone splint technique provides good mechanical support and increases the bone mass. It is an effective treatment for children with OI and lower limb deformities.

Weak link of tendon-bone healing and a control experiment to promote healing.

OBJECTIVE: This study aims to observe the mechanical weak point and histological features of tendon-bone interface after anterior cruciate ligament reconstructive surgery and to explore the tendon-bone healing effects of the platelet-rich gel (PRG) + deproteinized bone (DPB) compound. METHODS: A total of 48 New Zealand white rabbits were randomly divided into normal group, model (without embedding), experimental (embedded with the PRG + DPB compound), and control (embedded with DPB) groups. The rabbits were executed at 2, 4, 8, and 12 weeks after the operation. Then, micro-computed tomography scan and uniaxial tensile test were conducted. The fractured specimens were subjected to histological observation. RESULTS: At 4, 8, and 12 weeks after the operation, the bone density of the tendon-bone bound section of the experimental group was higher than that of the other groups (P < 0.05). At 4 and 8 weeks, the maximum tensile load of the experimental group was obviously higher than that of the control and model groups (P < 0.05). Histological observation indicated that the tendon-bone interface in the experimental group had more cartilage and bone tissue growing toward the internal tendon, but the fracture layer mainly occurred in the non-ankylosed part. CONCLUSION: The mechanical weak point of the early tendon-bone interface was in the immature fibrous tissue. The PRG + DPB compound can effectively trigger tendon-bone healing by promoting the maturation and ossification of the tendon-bone tissue. This compound improved the tensile strength of the healing interface and reduced bone tunnel enlargement.

MicroRNA-34a inhibits human osteosarcoma proliferation by downregulating ether à go-go 1 expression.

Aberrant expression of MicroRNAs (miRNAs) has been implicated in several types of cancer. As a direct target gene of p53, miR-34a has been suggested to mediate the tumor suppressor function of p53. Ether à go-go 1 (Eag1) channel is overexpressed in a variety of cancers and plays important roles in cancer progression. However, the link between miR-34a and Eag1 in cancer is unclear. In this study, we used human osteosarcoma as the model to demonstrate that miR-34a was significantly downregulated in osteosarcoma tissues and cell lines compared with normal brain tissues and osteoblastic cell line. Next we evaluated the role of miR-34a in the regulation of osteosarcoma cell proliferation by CCK-8 and colony formation assays. The results showed that overexpression of miR-34a inhibited the proliferation of MG-63 and Saos-2 cells. Furthermore, xenograft nude mice model showed that miR-34a inhibited osteosarcoma growth in vivo. Mechanistically, we found that overexpression of miR-34a led to decreased Eag1 expression in osteosarcoma cells while inhibition of miR-34a increased Eag1 expression. Taken together, our results suggest that miR-34a could inhibit osteosarcoma growth via the down regulation of Eag1 expression.