Prolonged efficacy of cefazolin in intraosseous regional prophylaxis for total knee arthroplasty: a rabbit model study.

BACKGROUND: A novel approach known as intraosseous regional administration (IORA) has emerged as a technique for delivering prophylactic antibiotics, and it results in higher tissue concentrations around the knee. It is hypothesized that IORA of cefazolin for antibiotic prophylaxis during total knee arthroplasty will result in sustained effective levels for a longer duration. The aim of the current study was to investigate temporal changes in peri-knee cefazolin blood concentrations after IORA of cefazolin. METHODS: Twelve rabbits were randomly divided into two groups, with six rabbits in each group. In control group a single intravenous bolus injection of cefazolin (10 mL, 100 mg) was administered into the marginal ear vein. In experimental groupexperimental group the same dose of cefazolin was injected into the left tibial marrow cavity after tourniquet inflation at the base of the left thigh. Blood samples were collected periodically at different timepoints, and cefazolin concentrations were determined. RESULTS: The intraosseous treatment resulted in significant differences in plasma cefazolin concentrations at all timepoints. Experimental group exhibited higher plasma cefazolin concentrations than control group. CONCLUSIONS: Cefazolin in intraosseous regional prophylaxis exhibits effectiveness in intraoperative antibiotic prophylaxis by maintaining concentrations above the minimum inhibitory concentration for extended durations, rather than relying solely on high concentrations.

Photo-induced imino functionalizations of alkenes via intermolecular charge transfer.

A catalyst-free photosensitized strategy has been developed for regioselective imino functionalizations of alkenes via the formation of an EDA complex. This photo-induced protocol facilitates the construction of structurally diverse ß-imino sulfones and vinyl sulfones in moderate to high yields. Mechanistic studies reveal that the reaction is initiated with an intermolecular charge transfer between oximes and sulfinates, followed by fragmentation to generate a persistent iminyl radical and transient sulfonyl radical. This catalyst-free protocol also features excellent regioselectivity, broad functional group tolerance and mild reaction conditions. The late stage functionalization of natural product derived compounds and total synthesis of some bioactive molecules have been demonstrated to highlight the utility of this protocol. Meanwhile, the compatibility of different donors has proved the generality of this strategy.

Nickel-catalyzed divergent Mizoroki-Heck reaction of 1,3-dienes.

Developing efficient strategies to realize divergent arylation of dienes has been a long-standing synthetic challenge. Herein, a nickel catalyzed divergent Mizoroki-Heck reaction of 1,3-dienes has been demonstrated through the regulation of ligands and additives. In the presence of Mn/NEt3, the Mizoroki-Heck reaction of dienes delivers linear products under Ni(dppe)Cl2 catalysis in high regio- and stereoselectivities. With the help of catalytic amount of organoboron and NaF, the use of bulky ligand IPr diverts the selectivity from linear products to branched products. Highly aryl-substituted compounds can be transformed from dispersive Mizoroki-Heck products programmatically. Preliminary experimental studies are carried out to elucidate the role of additives.

Prognostic factors associated with left ventricular non-compaction: A PRISMA-compliant meta-analysis.

BACKGROUND: Left ventricular non-compaction (LVNC) is a rare disease with a poor prognosis. Efforts to improve prognosis are limited by the quality and scope of the available evidence on prognostic factors. METHODS: Pubmed, Embase, China National Knowledge Infrastructure, Cochrane Library, Wanfang, and Baidu Scholar were searched and all relevant studies that examined factors related to LVNC prognosis, published before January 2021, were retrieved. Study quality evaluation and data extraction were independently completed by two authors. Statistical analyses were performed using STATA 15.0 software. RESULTS: A total of 20 cohort studies were included in this study, with a total of 1910 patients. The results of the meta-analysis are as follows: New York Heart Function Association (NYHA) class III/IV (hazard ratio [HR] = 3.93, 95% confidence interval [CI]: 1.66-9.29), (NT-proBNP) increased (HR = 1.98, 95% CI: 1.10-3.58), left ventricular ejection fraction (LVEF) decreased (HR = 1.04, 95% CI: 1.03-1.06), left ventricular end-diastolic diameter (LVEDD) increased (HR = 1.03, 95% CI: 1.01-1.06) was an independent poor prognostic factor, and body mass index (HR = 0.80, 95% CI: 0.64-0.98) was an independent protective factor. Creatinine (CR) level (HR = 1.09, 95% CI: 0.95-1.25) and late gadolinium-enhanced (LGE) imaging (HR = 3.1, 95% CI: 0.85-11.31) has no statistical significance in the prognosis of LVNC. CONCLUSION: In LVNC patients, NYHA class III/IV, elevated N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, decreased LVEF, and increased LVEDD may lead to poor prognosis, and increased body mass index may improve the prognosis of LVNC. Further clinical research with large sample sizes and long-term follow-ups should be conducted. PROSPERO REGISTRATION NUMBER: 42020152706.

Bioinspired and Ligand-Regulated Unnatural Prenylation and Geranylation of Oxindoles with Isoprene under Pd Catalysis.

In nature, prenylation and geranylation are two important metabolic processes for the creation of hemiterpenoids and monoterpenoids under enzyme catalysis. Herein, we have demonstrated bioinspired unnatural prenylation and geranylation of oxindoles using the basic industrial feedstock isoprene through ligand regulation under Pd catalysis. Pentenylated oxindoles (with C5 added) were attained with high selectivity when using a bisphosphine ligand, whereas upon switching to a monophosphine ligand, selectivity toward geranylated oxindoles (with C10 added) was achieved. Moreover, the head-to-head product could be further isomerized to an internal skipped diene under Pd-H catalysis. No stoichiometric by-product was formed in the process.

Comparison of Early Clinical Results for Femoral Neck System and Cannulated Screws in the Treatment of Unstable Femoral Neck Fractures.

OBJECTIVE: To compare early clinical effects of the femoral neck system (FNS) and three cannulated screws for the treatment of patients with unstable femoral neck fractures. METHODS: A retrospective analysis with pair matching of 81 patients who received FNS or cannulated screw internal fixation for Pauwels type-3 femoral neck fracture in our hospital from January 2019 to December 2019 was conducted. Patients who received FNS were the test group, and those who received cannulated screws comprised the control group. Matching requirements were as follows: same sex, similar age, and similar body mass index (BMI). A total of 30 pairs were successfully matched at a 1:1 ratio, including 12 males and 18 females. The average age of the patients in the FNS group was 54.53 ± 6.71 years. In the cannulated screw group, the average age of the patients was 53.14 ± 7.19 years. The operation time, intraoperative blood loss, hospital stay, hospitalization cost, postoperative visual analog scale (VAS) score, time to walking without crutches, Harris score, femoral head necrosis rate, and complication rate were compared between the groups. RESULTS: Postoperative re-examination of radiographs showed satisfactory reduction in all patients, and all patients were followed up for 10-22 months. Those in the FNS group had lower postoperative VAS scores, earlier times to walking without crutches, higher Harris scores at the last follow-up, and lower complication rates (P < 0.05). VAS scores were lower in the FNS group (3.13 ± 1.07 scores) than in the cannulated screw group (3.77 ± 1.04 scores) (P = 0.018). Patients in the FNS group (5.23 ± 1.33 months) recovered to walking without crutches earlier than did those in the cannulated screw group (6.03 ± 1.45 months) (P<0.001). In addition, a statistically higher postoperative Harris score was detected in the FNS group (86.16 ± 7.26) than in the cannulated screw group (82.37 ± 7.52) (P = 0.039). Overall, a higher incidence of complications was observed in the cannulated screw group (9/30) than in the FNS group (2/30) (P = 0.042). However, intraoperative blood loss and hospitalization costs were greater in the FNS group (P < 0.05). Intraoperative blood loss was greater in the FNS group (99.73 ± 4.69) than in the cannulated screw group (30.27 ± 9.04) (P<0.001). In addition, patients in the FNS group (46976 ± 2270 ¥) spent more on hospitalization costs than did those in the cannulated screw group (15626 ± 1732 ¥) (P<0.001). No statistically significant difference in operation time, hospital stay, or femoral head necrosis rate was observed between the two groups (P > 0.05). CONCLUSION: For patients with unstable femoral neck fractures, FNS has better clinical efficacy than cannulated screws, though it is also more expensive.

Redox-Divergent Construction of (Dihydro)thiophenes with DMSO.

Thiophene-based rings are one of the most widely used building blocks for the synthesis of sulfur-containing molecules. Inspired by the redox diversity of these features in nature, we demonstrate herein a redox-divergent construction of dihydrothiophenes, thiophenes, and bromothiophenes from the respective readily available allylic alcohols, dimethyl sulfoxide (DMSO), and HBr. The redox-divergent selectivity could be manipulated mainly by controlling the dosage of DMSO and HBr. Mechanistic studies suggest that DMSO simultaneously acts as an oxidant and a sulfur donor. The synthetic potentials of the products as platform molecules were also demonstrated by various derivatizations, including the preparation of bioactive and functional molecules.

Bipolar hemiarthroplasty compared with internal fixation for unstable intertrochanteric fractures in elderly patients.

BACKGROUND: The optimal treatment for unstable intertrochanteric fractures in elderly patients remains controversial. We aimed to compare internal fixation and bipolar hemiarthroplasty for the treatment of unstable intertrochanteric fractures in elderly patients. METHODS: 124 patients aged over 70 years were enrolled into this study (64 internal fixations, 60 bipolar hemiarthroplasties). Patients were followed for two years, and had a clinical, radiological, and functional review at three, six, and twelve months as well as two years. RESULTS: In the internal fixation group, the fracture reduction and internal fixation were regarded as satisfactory in 44 cases and unsatisfactory in 20 cases. Five patients in the internal fixation group (two with satisfactory results and three with unsatisfactory results) and three patients in the arthroplasty group died before the final two-year follow-up. Five patients in the internal fixation group who had unsatisfactory results suffered complications. At 24 months post-operation, patients who were treated satisfactorily with internal fixation had higher Harris scores, less pain, and better walking ability than those treated with hemiarthroplasty and unsatisfactory internal fixation. CONCLUSIONS: Internal fixation with good reduction and fixation quality should be the preferred therapeutic method for elderly unstable intertrochanteric fractures, even when severe osteoporosis is present.

[Experimental study on the expression of II type collagen and MMP-7 in acetabular cartilage of developmental dysplasia of hip].

OBJECTIVE: To detect the changes of expressions of II type collagen and matrix metalloproteinases-7 (MMP-7) of acetabular cartilage in early DDH (developmental dysplasia of hip) and to investigate the relevance between II type collagen and MMP-7 and the retrogression mechanism of acetabular cartilage. METHODS: The animal model of DDH was successfully established in 8 rabbits by applying the method of knee extension in which left lower extremity as experimental group and right one as control group. And the stains of HE and toluidine blue were applied on the samples of acetabular cartilage to observe the changes of chondrocytes and extracellular matrix (ECM). The techniques of immunohistochemical staining and Western blot were employed to respectively qualify and quantitate the expression of II type collagen and MMP-7. RESULTS: Pathohistological observation indicated the signs of retrogressive changes of acetabular cartilage in experimental group, including a loss of ECM in toluidine blue stain and a cluster of chondrocytes in HE stain. The positive numbers of II type collagen and MMP-7 by immunohistochemical staining in experimental group were both higher than that of control group. The quantitative amounts of II type collagen and MMP-7 by Western blot in experimental group were both higher than that of control group. Both significant differences existed between two groups (P < 0.05). CONCLUSION: The expression of II type collagen and MMP-7 is correlated to a retrogression of acetabular cartilage and increases obviously in early DDH. The amount and intensity of II type collagen and MMP-7 are probably the rationale of differential retrogression of cartilage.