Real-Time Monitoring of Tyrosine Hydroxylase Activity with a Ratiometric Fluorescent Probe.

Parkinson's disease (PD) represents the second most widespread neurodegenerative disease, and early monitoring and diagnosis are urgent at present. Tyrosine hydroxylase (TH) is a key enzyme for producing dopamine, the levels of which can serve as an indicator for assessing the severity and progression of PD. This renders the specific detection and visualization of TH a strategically vital way to meet the above demands. However, a fluorescent probe for TH monitoring is still missing. Herein, three rationally designed wash-free ratiometric fluorescent probes were proposed. Among them, TH-1 exhibited ideal photophysical properties and specific dual-channel bioimaging of TH activity in SH-SY5Y nerve cells. Moreover, the probe allowed for in vivo imaging of TH activity in zebrafish brain and living striatal slices of mice. Overall, the ratiometric fluorescent probe TH-1 could serve as a potential tool for real-time monitoring of PD in complex biosystems.

Tetrahedral Framework Nucleic Acid-Loaded Retinoic Acid Promotes Osteosarcoma Stem Cell Clearance.

Metastatic osteosarcoma is a commonly seen malignant tumor in adolescents, with a five year survival rate of approximately 20% and a lack of treatment options. Osteosarcoma cancer stem cells are considered to be important drivers of the metastasis of osteosarcoma, and therefore their clearance is considered a promising strategy for treating metastatic osteosarcoma. In the relevant literature, retinoic acid (ATRA) is considered effective for eliminating osteosarcoma stem cells, but it has some inherent disadvantages, including poor solubility, difficulty in entering cells, and structural instability. Tetrahedral framework nucleic acids (tFNAs) are a type of nanoparticles that can carry small-molecule drugs into cells to exert therapeutic effects. Therefore, we designed and synthesized a nanoparticle named T-ATRA by using tFNAs to load ATRA and studied its effect in a nude mouse model. T-ATRA is more effective than ATRA in the clearance of osteosarcoma stem cells and in inhibiting osteosarcoma cell metastasis via the Wnt signaling pathway, thus prolonging the survival time of nude mice with osteosarcoma.

Rational Design of Near-Infrared Fluorescent Probes for Accurately Tracking Lysosomal Viscosity with Allyl Snchoring Si-Rhodamine.

The abnormal microenvironment parameter, viscosity, is closely connected with various diffusion processes, signal transduction, molecule interactions, and various diseases. It is greatly significant to design viscosity-dependent near-infrared (NIR) small molecule fluorescence probes for visualizing biological processes or diagnosing diseases. Herein, through the stepwise modulating structure of the silicon-rhodamine fluorophore (SR), we report three viscosity probes with allyl or methyl group as rotors, named SR-T-Al, SR-S-Al, and SR-T-Me. Among them, SR-T-Al demonstrates better viscosity responsibility from 1.0 to 1410.4 cP of viscosity. Therefore, the probe of SR-T-Al is successfully applied to sensitively monitor lysosome microscopic viscosity changes of living cells induced by oxygen stress. What's more, based on its advantages in NIR emission (669 nm) and large Stokes shift (201 nm), we also use it to image variations of viscosity in an acute hepatitis mouse induced by carbon tetrachloride. Both time and concentration-dependent induction models display the great ability of SR-T-Al to detect viscosity alteration. All the experimental results indicated that this allyl-rotor-based NIR viscosity probe could provide a general platform to monitor abnormal physiological processes and diseases relating to viscosity.

Clinical efficacy of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in the treatment of II° lumbar isthmic spondylolisthesis: A retrospective cohort study.

Minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) is not suitable for high-grade isthmic spondylolisthesis, whether MIS-TLIF can treat II° lumbar isthmic spondylolisthesis (IS) is still controversial. This retrospective cohort study compared the clinical efficacy of MIS-TLIF and open transforaminal lumbar interbody fusion (OPEN-TLIF) in the treatment of II° lumbar IS. From January 2017 to January 2023, 101 patients with II° lumbar IS were diagnosed in our hospital and underwent surgical treatment, of which 53 received MIS-TLIF surgery and 48 received OPEN-TLIF surgery. The operation time, blood loss and surgical complications were compared between the 2 groups. The pain, function, reduction rate and fusion rate of the patients were evaluated during follow-up. The amount of intraoperative blood loss, postoperative drainage, and postoperative hospital stay in the MIS-TLIF group were significantly lower than those in the OPEN-TLIF group were (P < .01). In the MIS-TLIF group, there were 1 case of dural sac injury and 3 cases of lower limb paralysis. The complication rate of MIS-TLIF was lower than the OPEN-TLIF group (P = .032). In the visual analog scale score of low back pain, the MIS-TLIF group was lower than the OPEN-TLIF group after operation and at the last follow-up. There were no significant differences in postoperative leg pain score, slippage rate, and fusion rate between the 2 groups. Compared with OPEN-TLIF, MIS-TLIF has the advantages of better low back pain relief, less trauma, less bleeding and faster recovery, and is worthy of clinical promotion.

[Application of n-HA/PA66 composite artificial vertebral body in anterior reconstruction of lower cervical spine fracture and dislocation].

OBJECTIVE: To initially evaluate the application of artificial vertebra of n-HA/PA66 in anterior reconstruction of lower cervical spine fracture and dislocation. METHODS: In this study, 84 patients with lower cervical spine fracture and dislocation received anterior cervical discectomy, spinal canal decompression or subtotal corpectomy, spinal canal decompression and reconstruction by n-HA/PA66 composite artificial vertebral body combined with plate instrumentation. Neurological function was followed up by improvement rate of Frankel and situations of the supporting body was observed by X ray and 3D-CT in 3, 12, 24 months postoperatively. The intervertebral height, physical arc (reflected by Cobb angle) and the locations and fusion rate of the supporting body were assessed in order to evaluate the stability of the cervical spine and alignment improvements. RESULTS: All the patients underwent operation successfully and were followed up for 6 to 24 months with an average of 12 months. The preoperative symptoms were improved to varying degrees. Imaging studies showed that in all cases graft fusion were achieved, and cervical alignments, intervertebral height, cervical spine stability and the locations of the artificial vertebral body were well maintained. No displacement and subsidence of the artificial vertebral body occurred. Postoperative immediate intervertebral height (2.4 ± 0.2) cm, preoperative intervertebral height (1.9 ± 0.1) cm, comparisons of the two groups was statistically significant (q = 2.48, P < 0.001). The immediate, 3 month, 1 year, 2 year period follow-up group intervertebral height was not statistically significant (P > 0.05). Preoperative Cobb angle was 9.8° ± 1.2°, postoperative immediate Cobb angle was 16.6° ± 1.2°, comparisons of the two groups was statistically significant (q = 14.25, P < 0.001). The immediate, 3 month, 1 year, 2 year period follow-up group Cobb angle was not statistically significant (P > 0.05). CONCLUSIONS: n-HA/PA66 artificial vertebral body can provide early cervical spine support and stability and effectively maintain the biological alignment and cervical intervertebral height. It has high rate of graft fusion and is convenient to observe by X-ray. Therefore, n-HA/PA66 can be taken as an ideal graft for anterior lower cervical spine fracture and dislocation operation, but further follow-up study is still required to evaluate the long-term effects.

Use of small interfering ribonucleic acids to inhibit the adipogenic effect of alcohol on human bone marrow-derived mesenchymal cells.

This study tested the potential of small interfering RNAs (siRNA) targeting human peroxisome proliferator activated receptor gamma (PPARγ) to repress the adipogenic effect of alcohol on human bone marrow-derived mesenchymal cells (hBMSCs). hBMSCs were cultured from hip replacement surgery patients (n = 10). PPARγ-siRNA was transiently transfected into hBMSCs cultured in ostogenic media containing 50 mM alcohol by using a liposome-based strategy. Oil red O staining was used to test the development of differentiated adipocytes, and Alizarin red staining was used to test mineral deposition. Marker genes of adipogenesis (PPARγ2 and aP2) and osteogenesis (Osf2/Cbfa1) were examined through real time RT-PCR and Western blot, respectively. Collagen type I, alkaline phosphatase and osteocalcin protein synthesis of cultures were also assayed. Data were presented as mean ± SD. Differences between the means of the treatment groups were determined with ANOVA. PPARγ-siRNA transfection resulted in significantly lower adipocyte number, increased matrix mineralisation, repressed adipogenic gene markers, up-regulated osteogenic gene marker and bone matrix protein synthesis in the PPARγ-siRNA group compared to controls (P < 0.05). PPARγ-siRNA is a useful strategy to inhibit the adipogenic effect and the osteogenic repression of alcohol on hBMSCs. This may be a novel therapeutic intervention for osteopenic disorders in alcoholism and other conditions.

Minimally invasive technique versus conventional technique of dynamic hip screws for intertrochanteric femoral fractures.

INTRODUCTION: Intertrochanteric fractures of femur are common in elderly patients. The compression hip screw has become the predominant method for osteosynthesis of intertrochanteric fractures. However, the conventional dynamic hip screws (CDHS) technique has some disadvantages. Recently, we have used a minimally invasive dynamic hip screws (MIDHS) technique to reduce these disadvantages. This prospective study is to compare curative effect of MIDHS with that of CDHS with open reduction on Evans type 1 intertrochanteric fractures. MATERIALS AND METHODS: All 97 fractures were classified according to the Evans systems. The MIDHS group included 47 patients with an average age of 68.7 years, and the CDHS group included 50 patients with an average age of 68.7 years. The Singh index was used as a measure of osteoporosis. RESULTS: Both groups were similar in injury mechanism, fracture types, mean Singh index and medical diseases (all P > 0.50). All fractures were healed within 4 months in both groups except three cases who were implant failure and nonunion in the CDHS group. The MIDHS group had significantly smaller wound size, shorter surgery time, less blood loss, lower blood transfusion rate, earlier active mobilization of fractured hip joint, shorter hospital stay, lower serious complication rate and higher Harris hip score than the CDHS group (all P < 0.05). The satisfactory reduction, adequate screw position, healing time and union rate was not significantly difference between two groups (all P > 0.05). CONCLUSION: When the fractures are treated adequately, either the MIDHS or the CDHS with open reduction is an effective and safe method, but the MIDHS is superior to the CDHS with open reduction for the treatment of Evans type 1 intertrochanteric fractures of femur.

[Change in distribution of pathogens and nosocomial antibiotic resistant Gram-negative Bacilli infection in intensive care units one month after an earthquake].

OBJECTIVE: To investigate the change in distribution of pathogens and nosocomial antibiotic resistant Gram-negative Bacilli infection in intensive care units one month after an earthquake. METHODS: A retrospective survey on the distribution of nosocomial Gram-negative bacilli infection in intensive care units before and one month after the Wenchuan Earthquake was conducted in the West China Hospital. MicroScan Walkaway 96SI or PHOENIX 100 Automatic System in combined with manual identification, was employed to identify the Gram-negative bacilli infection and antibiotic resistance. RESULTS: The proportion of wound infection increased from 7.9% to 20.2% one month after the earthquake, but infection in respiratory tract stayed the most common infection. The common pathogens included Acinetobacter spp. (36.2%), Pseudomonas aeruginosa (22.7%), and Klebsiella spp. (12.3%) before the earthquake. One month after the earthquake, Imipenem remained highly sensitive against Escherichia coli and Klebsiella. spp., while their resistance to ceftazidime increased. Amikacin became the most sensitive antibiotics against Pseudomonas aeruginosa. Acinetobacter spp. had increased resistance to imipenem, but was highly sensitive to gatifloxacin and cefoxitin. The prevalence of extended spectrum beta-lactamases (ESBLs) in Klebsiella spp. and Escherichia coli increased from 52.6% and 48.8% before the earthquake to 55.0% and 87.5% one month after the earthquake, respectively. CONCLUSION: There is a significant change in distribution of pathogens and nosocomial antibiotic resistant Gram-negative Bacilli infection in intensive care units one month after the Earthquake, which might be associated with a sudden increase in injured patients. It is essential to regularly monitor the resistant rate of bacilli to antibiotics.

[Expression of Bcl-2 and Bax proteins in myocardial cells after Macleaya cordata alkaloids poisoning in rats].

OBJECTIVE: To observe the expression of Bcl-2 and Bax proteins in rat's myocardial cells after Macleaya cordata alkaloids poisoning, and to provide certain molecular biology references for the detection of Macleaya cordata alkaloids poisoning. METHODS: Experimental model of Macleaya cordata alkaloids poisoning was established, the expression levels of Bcl-2 and Bax proteins in these cells were detected by immunohistochemistry, and the results were analyzed by computer image system. RESULTS: The expression levels of Bcl-2 and Bax proteins in myocardial cells in poisoning groups were much greater than those in the control groups (P<0.05). CONCLUSION: If the clinical symptoms may not be obvious, the detection of Bcl-2 and Bax proteins level by immunohistochemistry still could be ancillary method.

[The crush syndrome patients combined with kidney failure after Wenchuan earthquake].

OBJECTIVE: To retrospectively analysis the treatment characteristics of the systemic situation in patients with crush syndrome after Wenchuan earthquake happened in May 12th, 2008. METHODS: Forty-nine patients with crush syndrome and subsequent acute renal failure (ARF) due to the earthquake were treated in West China Hospital. All of patients had been rescued from buildings that collapsed in Wenchuan earthquake. The major associated injuries were in the low extremities and upper extremities. 49 patients developed ARF with increased concentrations of serum creatinine (mean 64 022 U/L) had underwent haemodialysis. Hyperkalaemia was seen in 9 patients and four of them underwent haemodialysis. 49 patients were administered hemodialysis. RESULTS: No patient died. All patients who suffered from the ARF were weaned from hemodialysis after admitted 7 to 35 days. Forty-five extremities underwent amputations and 52 extremities had fasciotomy. CONCLUSIONS: Crush syndrome requires urgent recognition and prompt surgical treatment with simultaneous measures to control hyperkalemia and ARF. The authors believe that immediate intensive care therapy and multi-subjective coordination would have improved the survival rate.

Complications of Lumbar Disc Herniation Following Full-endoscopic Interlaminar Lumbar Discectomy: A Large, Single-Center, Retrospective Study.

BACKGROUND: The new surgical procedure of full-endoscopic interlaminar lumbar discectomy (FILD) has achieved favorable effects in the treatment of lumbar disc herniation (LDH). Along with the wide range of applications of FILD, a series of complications related to the operation has gradually emerged. OBJECTIVE: To describe the types, incidences, and characteristics of complications following FILD and to explore preventative and treatment measures. STUDY DESIGN: Retrospective, observational study. SETTING: A spine center affiliated with a large general hospital. METHOD: In total, 479 patients with LDH underwent FILDs that were performed by a single experienced spine surgeon between January 2010 and April 2013. Data concerning the complications were recorded. RESULTS: All 479 cases successfully underwent the procedure. A total of 482 procedures were completed. The mean follow-up time was 44.3 months with a range of 24 to 60 months. The average patient age was 47.8 years with a range of 16 to 76 years. Twenty-nine (6.0%) related complications emerged, including 3 cases (0.6%) of incomplete decompression in which the symptoms gradually decreased following 3 - 6 weeks of conservative treatment, 2 cases (0.4%) of nerve root injury in which the patients recovered well following 1 - 3 months of neurotrophic drug and functional exercise treatment, 15 cases (3.1%) of paresthesia that gradually improved following 1 - 8 weeks of rehabilitation exercises and treatment with mecobalamin and pregabalin, and 9 cases of recurrent herniation (1.9%). The latter condition was controlled in 4 cases with a conservative method, and 5 of these cases underwent reoperations that included 3 traditional open surgeries and 2 FILDs. Furthermore, the complication rate for the first 100 cases was 18%. This rate decreased to 2.9% for cases 101 - 479. The incidence of L4-5 herniation (8.2%) was significantly greater than that of L5-S1 (4.5%). LIMITATIONS: This is a retrospective study, and some bias exists due to the single-center study design. CONCLUSION: FILD is a surgical approach that has a low complication rate. Incomplete decompression, nerve root injury, paresthesia, and recurrent herniation were observed in our study. Some effective measures can prevent and reduce the incidence of the complications including strict indications for surgery, a thorough action plan, and a high level of surgical skill. Key words: Complication, lumbar disc herniation, lumbar discectomy, endoscopic, inter-laminar discectomy, minimally invasive spine surgery.

[Anterior decompression and fusion with n-HA/PA66 cage for the treatment of lower cervical fracture and dislocation].

OBJECTIVE: To explore the clinical effects of anterior decompression and fusion with a nano-hydroxyapatite/ polyamide 66 (n-HA/PA66) cage in treating lower cervical fracture and dislocation. METHODS: From January 2008 to December 2010, the clinical data of 42 patients with lower cervical fracture and dislocation were retrospectively analyzed. There were 29 males and 13 females aged from 20 to 65 years old. The mean age was 46.8 years. Five cases got injuried in C3, 14 cases in C4, 12 cases in C5, 7 cases in C6 and 4 cases in C7. According to Frankel grade, 4 cases were classified in grade A, 11 cases in grade B, 13 cases in grade C, 9 cases in grade D and 5 cases in grade F. Twenty-eight cases were treated with anterior corpectomy and fusion and 14 cases with anterior discectomy and fusion. Frankel grade was used to do neurologic assessment and visual analogue scale (VAS) was used to evaluate the improvement of clinical symptoms. Segmental height and sagittal lordosis were measured by radiographs and cage location. Cage appearance and fusion status were assessed by 3D-CT images. RESULTS: All patients were followed up for 3 to 5.2 years with an average of 4.1 years. Frankel grade had obviously improved than preoperative (Z = -4.845, P < 0.001). There were 2, 3, 11, 8, 11 cases classified in grade A, grade B, grade C, grade D and grade E respectively. At the third day after operation and latest follow-up,VAS was (2.6 +/- 1.8),(1.3 +/- 1.0) scores respectively. Both had improved than preoperative (P < 0.05). Up to the latest follow-up, there was only one patient (2.4%) with slight cage translocation (less than 2 mm), however, no cage prolapsed, or collapse, or breakage were found. Both segmental height and lordosis improved significantly after surgery (P < 0.001). And there was not significant difference in both parameters between each postoperative time points (P > 0.05). The mean distance of cage subsidence was 1.5 mm and the rate of cage subsidence (> 3 mm) was 4.8%. CONCLUSION: The n-HA/PA66 cage can not only restore and maintain the fusion segmental height and radian, but also promote the osseous fusion and profit the radiographic assessment after operation. Thus, it was an ideal material for prop graft.

Causes, treatment and prevention of esophageal fistulas in anterior cervical spine surgery.

OBJECTIVE: To evaluate the causes, treatment and prevention of esophageal fistulas after anterior cervical spine surgery. METHOD: Between January 2004 and December 2011, 5 of 2348 patients who underwent anterior cervical surgery in our hospital developed esophageal fistulas (three male and two female patients, average age 34 years). Their diagnoses were cervical injuries (three), cervical spondylosis (one) and cervical tuberculosis (one). Their esophageal fistulas were treated by debridement and exploratory surgery, primary suturing of the perforation and/or sternocleidomastoid myoplasty. If conservative treatment failed or esophageal fistula recurred, plate removal was offered. Postoperative treatment included esophageal rest, enteral nutrition, wound drainage, and antibiotics. Methylene blue was used to evaluate results. RESULT: An esophageal fistula was discovered during anterior cervical surgery in one patient and primary suturing performed. In four patients, fistulas were diagnosed after anterior cervical decompression and fusion. In one of these, only debridement and exploratory surgery were required. In another, a perforation was sutured during debridement and exploratory surgery. In the third, internal fixation was removed because of failure of prolonged conservative treatment. In the fourth, the esophageal fistula recurred repeatedly; he required removal of the hardware and reinforcement with a sternocleidomastoid muscle flap. At 6-48 months follow-up, all patients were in good condition, symptom free, and without cervical instability or infectious spondylitis. CONCLUSION: Successful management of esophageal fistula after anterior cervical spinal surgery depends on primary closure of the perforation with or without muscle flaps, surgical drainage, esophageal rest and nutritional support, and removal of hardware if necessary. Prevention consists of careful surgery and gentle tissue handling.

[Percutaneous screw fixation for pelvic fractures with fluoroscopy-based navigation].

OBJECTIVE: To investigate the applications of fluoroscopy-based navigation in pelvic fractures and related surgical considerations. METHODS: From May 2010 to December, 16 patients with pelvic fractures were treated with computerized navigation. There were 12 males and 4 females with an average age of 37 years (ranged from 20 to 54 years). Fractures were caused by traffic accident in 5 cases, crush injury in 5 cases and falling from height in 6 cases. Based on the Tile classification, there were 15 cases of Tile C type and 1 case of Tile B type. In these patients, 4 patients were treated with sacroiliac screw fixation; 2 patients were treated with sacroiliac screw fixation, screw fixation for pubic symphysis diastasis and pubic fractures; 8 patients were treated with sacroiliac screw fixation and screw fixation for pubic fractures; 2 patients were treated with screw fixation for pubic fractures. The index such as screw inserting time, accurance of inserting screws, intra-operative blood losing, injuries of nerve, vascular and other organs, reduction conditions were observed. RESULTS: A total of 36 screws were inserted. The average time was 20 min for each screw placement. The blood loss ranged from 10 to 20 ml. There were no wound infections, neurovascualr injuries and other organ injuries. The postoperative pelvic X-ray and three-dimensional CT showed that the fractures had good reduction and all the screws had good position. CONCLUSION: Percutaneous screw fixation of pelvic fractures with fluoroscopy-based navigation have advantages such as little trauma, less blood loss, little complication, reliable fixation and no blood transfusion, which can reconstruct the stability of the pelvic ring, but need adequate preoperative reperation and high requirements for the surgeon.

[Potential seeding cells for cartilage tissue engineering--bone marrow stromal stem cells].

OBJECTIVE: To review the recent research progress of bone-marrow stromal stem cells (BMSCs) in the conditions of culture in vitro, chondrogenic differentiation, and the application in cartilage tissue engineering. METHODS: Recent original articles related to such aspects of BMSCs were reviewed extensively. RESULTS: BMSCs are easy to be isolated and cultivated. In the process of chondrogenesis of BMSCs, the special factors and interaction between cells are investigated extensively. BMSCs have been identified to form cartilage in vivo. One theory is the committed chondrocyte from BMSCs is only a transient stage. CONCLUSION: BMSCs are the alternative seeding cells for cartilage tissue engineering. The conditions promoting mature chondrocyte should be further investigated.