[Comparison of therapeutic effects of arthroscopic popliteal cyst internal drainage and capsular wall resection].

OBJECTIVE: To investigate efficacy between arthroscopic popliteal cyst drainage and arthroscopic popliteal cyst resection. METHODS: From January 2013 to June 2021, 54 patients with popliteal cyst (Rausching-Lindgren gradeⅠto Ⅲ) were treated with arthroscopic surgery. There were 24 males and 30 females. The age ranged from 44 to 72 years old, with a mean of (62.67±6.08) years old. The course of the disease ranged from 1 to 72 months, with a mean of(15±14) months. Twenty-four patients (group A) were underwent arthroscopic internal drainage of popliteal cyst. Thirty patients (group B) were underwent arthroscopic resection of popliteal cyst. Preoperative main symptoms included knee pain, swelling, walking pain, popliteal swelling, popliteal mass and so on. After 1, 3, 6 months and 1, 2 years of surgery, routine outpatient follow-up was conducted to observe and compare the surgical time, bleeding volume, preoperative and postoperative visual analog scale (VAS), knee Lysholm score, and complications between two groups. RESULTS: All incisions healed at one stage after operation. All 54 patients were followed up, and the duration ranged from 6 months to 2 years, with an average of (13.89±4.29) months. There was no intraoperative vascular or nerve injury. Operation time and intraoperative blood loss of the two groups:group A of (62.08±9.55) min and (8.00±1.69) ml, group B of (69.50±6.99) min and (8.70±2.00) ml. Popliteal pain, swelling, limitation of flexion and extension were significantly relieved after operation. VAS before and one month after operation between two groups:group A of 5.38±1.21 and 2.63±0.71, group B of 5.60±1.26 and 2.80±0.81. Lysholm scores of knee joint before and 6 months after operation:group A of 62.59±4.99 and 89.74±2.90, group B of 63.87±3.23 and 89.02±2.35. Knee joint function improved significantly in both groups. In group A, 4 cases had popliteal cyst at 3 months after operation, and 2 cases had small isolated cyst at 1 year after operation. There was no recurrence of cyst in group B. CONCLUSION: The results between two arthroscopic treatments of popliteal cyst are satisfactory, and there is no significant difference in the amount of blood loss, safety, postoperative pain VAS score and knee function recovery. It is suggested that arthroscopic resection of the cyst wall should be performed when the technique is mature, especially for large cysts and septal cysts.

[Locking compression plate combined with medial buttress plate for the treatment of osteoporotic comminuted proximal humerus fractures].

OBJECTIVE: To explore clinical effect of lateral locking compression plate combined with medial buttress plate in treating osteoporotic comminuted fractures of proximal humerus. METHODS: From May 2017 to December 2021, 12 patients with osteoporotic comminution of proximal humerus were treated by lateral locking compression plates combined with medial buttress plates, including 5 males and 7 females, aged from 55 to 78 years old, bone mineral density(BMD) less than -2.5 g/cm3, the time from injury to operation was from 2 to 6 days. According to Neer classification, 7 patients were type Ⅲ, 4 patients were type Ⅳ and 1 patient was type Ⅵ. Postoperative complications, fracture healing and internal fixation were observed and Constant-Murley score of shoulder joint was used to evaluate clinical effects at 6 months after operation. RESULTS: Postoperative wound healed well at stage I. All patients were followed up from 6 to 18 months. Humeral head collapse and necrosis occurred in 1 patient and humeral head varus in 1 patient. No impact of shoulder joint, internal fixation loosening occurred. Constant-Murley score at 6 months ranged from 45 to 90 points, and 6 patients got excellent result, 3 good, and 3 poor. CONCLUSION: Locking compression plate combined with medial buttress plate could effectively reconstruct medial humeral column support and enhance fracture stability, and receive satisfactory clinical results. However, no control group was established in this study, and function of shoulder joint has not been evaluated many times after operation, so it cannot dynamically reflect changes of shoulder joint function.

[Identifying Nitrate Sources in a Typical Karst Underground River Basin].

Underground rivers are an important source of groundwater in karst area. Recently, nitrate pollution of underground rivers has become a serious issue. To identify the sources of nitrate in Guancun typical karst underground river basin, stable isotope techniques (δ15N-NO3-, δ18O-NO3-, and δ18O-H2O) were applied in this study. The contribution rates of different nitrate sources in groundwater were quantitatively identified based on the stable isotope analysis in R (SIAR) model, and the influence of land use type on nitrate distribution and source in watershed water was clarified. The results showed that ① nitrate mainly came from fertilizers, soil organic nitrogen, and manure/sewage based to the isotopic composition of nitrate nitrogen and oxygen isotopes. It was revealed that non-point sources significantly contributed to nitrate in waters of the Guancun underground river basin. ② Nitrification dominated the formation process of nitrate in groundwater, and the initial values of nitrogen and oxygen isotopes were not affected by fractionation. ③ Based on SIAR, the contribution of different sources to nitrate in water in the basin varied seasonally, and the contributions of fertilizer, soil organic nitrogen, and manure/sewage to nitrate were 57.07%, 34.06%, and 8.87% in the wet season and 34.14%, 33.02%, and 32.84% in the dry season, respectively. Overall, the present study quantitatively evaluated the temporal variations of nitrate sources in a typical karst groundwater river basin and provided a theoretical foundation for prevention and control management of non-point source pollution and watershed management in karst areas.

[Analysis of Nitrate Sources in Different Waters of a Karst Basin].

To identify the sources and transformation processes of nitrate in surface water and groundwater in a karst basin, water samples were collected in the Songbai Mountain Reservoir basin during the normal and dry seasons. The spatio-temporal distribution, sources, and transformation processes of nitrate in the waters were analyed using a hydrochemical and stable isotopic (δ15N-NO3-, δ18O-NO3-, and δ18O-H2O) multi-tracing approach. The contribution rates of different nitrate sources in surface and groundwater were estimated based on the SIAR model. The results showed that NO3--N and NH4+-N were the main species of dissolved inorganic nitrogen in the waters. The over standard rate of NO3--N in groundwater was 7.89% in the normal season and 16.67% in the dry season. Temporally, the nitrate concentrations of waters in the dry season were higher than those in the normal season. Spatially, the nitrate concentrations of groundwater around dryland areas (from the Kailun River to the Songbai Mountain Reservoir) were higher than those of paddy fields (Ganhe River), and the nitrate concentrations of surface water in dryland and construction sites (Kailun River) were generally high. Nitrification was the dominant process in the waters. The nitrate in the waters mainly came from soil organic nitrogen, manure/sewage, and chemical fertilizers; their contribution rates to nitrate were 36.7%, 34.7%, and 28.6% for surface water and 39.9%, 34.9%, and 25.2% for groundwater, respectively. Nitrate pollution in the waters was mainly affected by agricultural activities and the discharge of sewage; appropriate control measures such as water and fertilizer regulation for farmland and treatment of rural sewage should be strengthened.

[Temporal Response of Subterranean Karst Stream Hydrochemistry to Urbanization].

The hydrochemical responses of underground rivers to urbanization were studied using a 25-year groundwater observation dataset and remote sensing. We found that as urbanization progresses, the mineralization degree of underground rivers gradually increases; time-series data for dominant hydrochemical indicators changed from HCO3·SO4-Ca·Mg during the dry season and HCO3-Ca·Mg during flood season to HCO3·Cl-Ca, HCO3·SO4-Ca, HCO3-Ca, and HCO3·SO4-Ca·Mg. Influenced by surface precipitation input, the groundwater chemistry of underground rivers varies greatly during the dry season and the flood season. Prior to urbanization,[Mg2+]/[Ca2+] and[HCO3-]/[SO42-] molar ratios are affected by water-rock interactions, agricultural activities, and acid rain infiltration, the average values of which were 0.86 and 29.34, respectively. After urbanization, agricultural activities and the contribution from acid rain decreased gradually. During the periods 1990-1995, 1996-2010, and 2011-2015, the main sensitive geochemical cations were Ca2+, Mg2+, Na+, and NH4+, and the main anions were HCO3-, HCO3-, and SO42-, and Cl-. The hydrochemical response of underground rivers to urbanization was characterized by clear temporal phases.

Multilayered pore-closed PLGA microsphere delivering OGP and BMP-2 in sequential release patterns for the facilitation of BMSCs osteogenic differentiation.

Bone tissue regeneration may be more effectively administrated by controlled release of multiple biofactors, given that bone healing comprises a cascade of biological events controlled by numerous cytokines and growth factors (GFs). Here, we propose a novel microcarrier with the capability to sequentially deliver dual biofactors for better controlling the bone regeneration process. First, osteogenic growth peptide (OGP) was incorporated in porous poly(lactic-co-glycolic) acid (PLGA) microspheres by a simple solution dipping method and subsequent pore-closing treatment. Then, a multilayered polyelectrolyte coating ((HA-CS)2 -Hep-BMP-2-Hep-(CS-HA)2 ) was prepared on the surface of such OGP-loaded pore-closed PLGA microspheres by layer-by-layer assembly. Results showed that the OGP release was minimal (<17.1%) in the first 15 days but accelerated remarkably thereafter, while at least 60.3% of the bone morphogenetic protein-2 (BMP-2) load was released in the first 15 days and only very slow release was observed subsequently. Further in vitro cell experiments showed that the dual-biomolecule-loaded microspheres elicited more cells with extremely elongated cellular morphology, much higher alkaline phosphatase level and upregulated expression of osteocalcin. Such a dual loading of OGP and BMP-2 had a more positive impact on bone marrow mesenchymal stem cells proliferation and osteogenic differentiation compared with either OGP or BMP-2 alone, suggesting potential synergistic benefit of the sequential release of multiple peptide-based biofactors in a coordinated manner. Overall, this dual delivery system may provide a therapeutic strategy sequentially targeting multiple events (or mechanisms) during bone healing, which is believed to benefit the regenerative repair of bone defects. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 95-105, 2018.

Enhanced osteogenesis of multilayered pore-closed microsphere-immobilized hydroxyapatite scaffold via sequential delivery of osteogenic growth peptide and BMP-2.

Since many complex physiological processes are controlled by multiple biomolecules, comprehensive regulation of bone tissue regeneration may be more effectively achieved by administering more than one type of biofactor. Thus, we propose a novel bone tissue engineering scaffold incorporating a multiple peptide-based drug delivery vehicle for accelerated bone regeneration. Pore-closed poly(lactic-co-glycolic acid) (PLGA) microspheres with a surface structure of multilayer polyelectrolytes ((Ha-Cs)2-Hep-BMP-2-Hep-(Cs-Ha)2) were prepared as multi-barrier microcarriers for osteogenic growth peptide (OGP). In addition, BMP-2 loading was achieved via a pore-closing process and layer-by-layer (LbL) assembly technique, followed by immobilization on the surface of a highly interconnected porous hydroxyapatite (HA) scaffold. On the basis of such a construction, sequential delivery of OGP and BMP-2 occurred in a coordinated manner through an orchestrated sequence of spatial changes, targeting different bone healing stages. The in vitro studies showed that OGP release was minimal (<11.7%) in the first 15 d but accelerated remarkably thereafter, while at least 56.3% of BMP-2 payload was released at this time and subsequent release was only marginal. In addition, scaffolds carrying dual-biofactor exhibited a stronger ability to induce bone marrow mesenchymal stem cell (BMSC) differentiation toward osteoblasts than those incorporating OGP or BMP-2 alone and factor-free scaffolds in terms of alkaline phosphatase (ALP) activity and osteogenic gene and protein (Runx2, COL I, and OCN) expression. The results of in vitro cell culturing demonstrated the roles of BMP-2 in osteogenic differentiation early as well as the effect of OGP on accelerated proliferation and maturation of osteoblast precursors at a later stage. Further in vivo osteogenesis studies also revealed that the dual biofactor-loaded scaffold manifested the best repair efficacy due to a potential synergistic effect of BMP-2 and OGP. Collectively, our findings suggested that such a dual delivery system may provide a therapeutic strategy sequentially targeting multiple events or mechanisms during bone healing and was proved to be a promising therapeutic scaffold for future use in bone tissue regeneration.