Pityriacitrin marine alkaloids as novel antiviral and anti-phytopathogenic-fungus agents.

BACKGROUND: Plant diseases have been gripping agricultural production, seriously affecting the growth and yields of crops. Marine natural products are an important source for novel drugs discovery. In this work, pityriacitrin marine alkaloids were selected as the parent structures. A series of pityriacitrin alkaloid analogues were rationally designed, synthesized and evaluated for their antiviral activities and fungicidal activities. RESULT: Most of these compounds were demonstrated to have higher antiviral activities than ribavirin. Particularly, compounds 3a, 3e, 8f, 8g, and 9g displayed higher anti-TMV activities than ningnanmycin at 500 µg·mL-1 . Mechanism research revealed that 3a could bind to TMV CP with an excellent affinity (Ka  = 8.67 × 106 L·mol-1 ), thus interfere with the assembly of virus particles. These alkaloids also showed broad-spectrum fungicidal activities against eight kinds of phytopathogenic fungi. Compound 5f with 1.43-3.84 µg·mL-1 EC50 value against three fungi emerged as a new fungicidal candidate. CONCLUSION: Pityriacitrin alkaloids and their derivatives were synthesized and evaluated for anti-TMV and fungicidal activities for the first time. Compounds 3a and 5f with excellent activities emerged as new candidates for antiviral research and fungicidal research, respectively. Current work provided a new idea for the molecular design and development of novel plant virus and fungi inhibitors in the future. © 2021 Society of Chemical Industry.

Treatment of Thoracolumbar Fractures Through Different Short Segment Pedicle Screw Fixation Techniques: A Finite Element Analysis.

OBJECTIVE: To compare the von Mises stresses of the pedicle screw system and the displacement of injured vertebrae using 3-D finite element analysis, and to evaluate the curative effect of the pedicle screw system. METHODS: Finite element methods were used for biomechanical comparison of four posterior short segment pedicle screw fixation techniques. The different pedicle screw models are traditional trajectory (TT), Universal Spine System (USS), cortical bone trajectory (CBT), and CBT at the cranial level and pedicle screw (PS) at the caudal level (UP-CBT). The stress distribution of the screws and connecting rods under different working conditions and the displacement of the injured vertebrae were compared and analyzed. RESULTS: After the pedicle screw system was fixed, the stress under vertical compression was mainly concentrated at the proximal end of the screw, while the stress was mainly concentrated on the connecting rod during flexion, extension, lateral flexion, and rotation. The TT group had the greatest stress during the flexion, extension, and left and right rotation. The UP-CBT group was most stressed when the left and right sides were flexed; the stress of the USS screw system was less than that of the other three models during flexion, lateral flexion, and rotation. The maximum von Mises stress values of pedicle screws in all exercise states were 556.2, 340.7, 458.1, and 533.4 MPa, respectively. In the USS group, the displacement of the injured vertebra was small in the flexion, and the left and right lateral flexion and the right rotation were higher than in the TT group and the CBT group. The maximum displacements of the injured vertebrae in all motion states were 1.679, 1.604, 1.752, and 1.777 mm, respectively. CONCLUSION: Universal Spine System pedicle screws are relatively less stressed under different working conditions, the risk of breakage is small, and the model is relatively stable; CBT screws do not exhibit better mechanical properties than conventional pedicle screws and USS pedicle screws.

Biocompatible Porous Tantalum Metal Plates in the Treatment of Tibial Fracture.

Fractures of the tibia represent a common class of injuries in orthopedics. The blood supply to the tibia is poor due to the small subcutaneous muscle tissues inside. Consequently, the tibia is prone to delayed fracture healing and nonunion of the fracture after surgery. In this case, we used porous tantalum metal plate to treat nonunion of a tibial fracture and achieved satisfactory therapeutic effects. For the first time in the field, we used 3D printing technology to fabricate porous tantalum metal plates for the treatment of tibial fractures. The resulting porous tantalum metal exhibited excellent mechanical and biological properties, and improved the therapeutic effects for the treatment of a tibial fracture nonunion. Porous tantalum metal plates have great application potential as a new implant material for internal fixation.

Decreased synovial fluid omentin-1 concentrations reflect symptomatic severity in patients with knee osteoarthritis.

The aim of this study was to measure omentin-1 concentrations in serum and synovial fluid (SF) of knee osteoarthritis (OA) patients and to investigate their correlation with patient-reported symptomatic severity. We enrolled 263 knee OA patients and 62 healthy controls. We collected Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores from OA patients and measured omentin-1 concentrations in serum and SF by enzyme-linked immunosorbent assay (ELISA). Our results demonstrated that omentin-1 concentrations in SF but not serum were independently and negatively correlated with self-reported greater pain and physical disability in OA patients. Omentin-1 in SF might serve as a potential biomarker for reflecting the symptomatic severity of OA.

[Treatment of non-traumatic avascular talar necrosis by transposition of vascularized cuneiform bone flap plus iliac cancellous bone grafting].

OBJECTIVE: To evaluate the outcome of cancellous bone grafting plus iliac cancellous bone in the treatment of non-traumatic avascular talar necrosis. METHODS: Twenty patients, 14 males and six females, eight at stage II, ten at stage III and three at stage IV according to the modified Ficat & Arlet necrosis classification system, were treated with vascularized bone flap from January 2000 to June 2005. RESULTS: All patients were followed up for a mean of 37 months (range: 14 to 68 months). The clinical function outcome evaluated by Kenwright criteria were excellent in 8 cases, good in 10 cases, fair in 1 case and poor in 1 case. Clinical symptom was completely or partially relieved. The necrotic area was filled with newly formed bone and the excellent-to-good rate was 90%. CONCLUSION: Transposition of vascularized cuneiform bone flap plus iliac cancellous bone grafting may be an ideal therapeutic method for non-traumatic avascular talar necrosis. And the clinical outcome is satisfactory.

[Evaluation of hemodynamic changes by digital subtraction angiography after treatment of avascular osteonecrosis of femoral head with vascularized bone flaps].

OBJECTIVE: To evaluate the effect of digital subtraction angiography (DSA) in evaluation of the hemodynamic changes after treatment of avascular osteonecrosis of femoral head with vascularized bone flaps. METHODS: Fifty-four patients, 33 males and 21 females, 33 hips being at the stage II and 21 hips being at the stage III, were treated with vascularized bone flaps, including iliac bone flaps pedicled with ascending branch of lateral femoral circumflex artery for 23 hips, greater trochanter bone flaps pedicled with gluteal muscle branch of ascending branch of lateral femoral circumflex artery for 13 hips, greater trochanter bone flaps pedicled with transverse branch of ascending branch of lateral femoral circumflex artery for 9 hips, and greater trochanter bone flaps pedicled with gluteal muscle branch and transverse branch of ascending branch of lateral femoral circumflex artery for 9 hips. Selective DSA was performed on all 54 patients pre-operatively and on 19 patients 6-24 months post-operatively. RESULTS: DSA before operation demonstrated abnormal vascularization in all 54 patients. Six months after operation reconstruction of blood supply on the femoral head was seen in 48 cases. Six patients showed poor filling or failure of filling of the vessel pedicles in transplanted bone flaps 6 months post-operatively and DSA conducted 8 months postoperatively showed satisfactory filling in one of the 6 cases. The clinical success rate of this group was 91%, and the radiological success rate was 85%. CONCLUSION: Selective DSA is effective in evaluation of the postoperative hemodynamic changes in the necrotic femoral head. Significant blood supply in the bone flap is the key point in the success of treatment of ONFH.

[Conservative methods for osteonecrosis of the femoral head: the review of 1005 cases].

OBJECTIVE: To research on the conservative methods used to preserve the femoral head of patients with osteonecrosis of the femoral head. METHODS: In these series surgical procedures the osteonecrotic lesion was removed and various vascularized bone blocks or periosteal flaps with its nutrient vessels were transferred to regain sphericity of the femoral head and reinforce the sequestrum. The current study assessed 1005 patients (1226 hips) operated on from 1989 to 2002 with an average follow-up of 5.1 years (range, 1.5-15 years). The mean age of the patients was 37.4 years (range, 17-65 years). RESULTS: Sixty-one hips (57 patients) had conversion surgery to a total hip arthroplasty because of progressive collapse or severe pain, or both. In the patients without failure, postoperative Harris hip score improved significantly. Of the 1174 reconstructions that were in situ, 1041 (89.4%) were clinically successful, and 878 (75.4%) were radiologically successful. In relation to the stage of necrosis according to the classification system of Ficat and Alert, good results were achieved in 95.3% of the patients with stages II disease, 87.9% with stages III and 60.8% with stages IV. CONCLUSIONS: Conservative methods of vascularized bone block or periosteal flap transfer should be considered in active symptomatic patients to preserve the femoral head. In addition, the earlier the stages of the disease the better outcome could be obtained.