The safety and efficacy of neoadjuvant immunochemotherapy following laparoscopic gastrectomy for gastric cancer: a multicenter Real-world clinical study.

BACKGROUND: The safety and efficacy of neoadjuvant immunochemotherapy (nICT) for locally advanced gastric cancer (LAGC) remain controversial. METHODS: Patients with LAGC who received either nICT or neoadjuvant chemotherapy (nCT) at 3 tertiary referral teaching hospitals in China between January 2016 and October 2022 were analysed. After propensity-score matching (PSM), comparing the radiological response, pathological response rate, perioperative outcomes, and early recurrence between the two groups. RESULTS: After PSM, 585 patients were included, with 195 and 390 patients comprising the nICT and nCT groups, respectively. The nICT group exhibited a higher objective response rate (79.5% versus [vs.] 59.0%; P<0.001), pathological complete response rate (14.36% vs. 6.41%; P=0.002) and major pathological response rate (39.49% vs. 26.15%; P=0.001) compared with the nCT group. The incidence of surgical complications (17.44% vs. 16.15%, P=0.694) and proportion of perioperative textbook outcomes (80.0% vs. 81.0%; P=0.767) were similar in both groups. The nICT group had a significantly lower proportion of early recurrence than the nCT group (29.7% vs. 40.8%; P=0.047). Furthermore, the multivariable logistic analysis revealed that immunotherapy was an independent protective factor against early recurrence (odds ratio 0.62 [95% CI 0.41-0.92]; P=0.018). No significant difference was found in neoadjuvant therapy drug toxicity between the two groups (51.79% vs. 45.38%; P=0.143). CONCLUSIONS: Compared with nCT, nICT is safe and effective, which significantly enhanced objective and pathological response rates, and reduced the risk for early recurrence among patients with LAGC. TRIAL REGISTRATION: Clinical Trials.gov.

Long-term survival outcomes of robotic total gastrectomy for locally advanced proximal gastric cancer: a prospective study.

BACKGROUND: Robotic gastrectomy is a safe and feasible approach for gastric cancer (GC); however, its long-term oncological efficacy remains unclear. We evaluated the long-term survival outcomes and recurrence patterns of patients with locally advanced proximal GC who underwent robotic total gastrectomy (RTG). METHODS: This prospective study (FUGES-014 study) enrolled 48 patients with locally advanced proximal GC who underwent RTG between March 2018 and February 2020 at a tertiary referral teaching hospital. Patients who underwent laparoscopic total gastrectomy (LTG) in the FUGES-002 study were enrolled in a 2:1 ratio to compare the survival outcomes between RTG and LTG. The primary endpoint of the FUGES-014 study was postoperative 30-day morbidity and has been previously reported. Here we reported the results of 3-year disease-free survival (DFS), 3-year overall survival (OS), and recurrence patterns. RESULTS: After propensity score matching, 48 patients in the RTG and 96 patients in the LTG groups were included. The 3-year DFS rates were 77.1% (95% confidence interval [CI] 66.1-89.9%) for the RTG and 68.8% (95% CI 60.1-78.7%) for the LTG groups ( P =0.261). The 3-year OS rates were not significantly different between the groups (85.4% vs. 74.0%, P =0.122). Recurrence occurred in nine patients (18.8%) in the RTG and 27 (28.1%) patients in the LTG groups ( P =0.234). Recurrence patterns and causes of death were similar between the groups ( P >0.05). CONCLUSIONS: The oncological outcome of RTG was non-inferior to that of LTG. Thus, RTG might be an alternative surgical treatment for locally advanced proximal GC.

Preparation and property analysis of antioxidant of carbazole derivatives.

Carbazole derivatives can be used as antioxidants in the lubricating oil industry. The alkylation of carbazole with 2-chloro-2-methylpropane and 2-bromopropane catalyzed by anhydrous aluminum chloride was studied. Initially, 3,6-di-iso-propylcarbazole and 3,6-di-tert-butylcarbazole were using dichloromethane and dibromomethane as solvents at room temperature, respectively. The synthesis conditions were optimized. Subsequently, the effects of reaction time, catalyst dosage, and molar ratio of carbazole to alkylating agent were investigated, and orthogonal experiments were performed. The structures of the carbazole derivatives were characterized by Fourier infrared spectroscopy (FT-IR), mass spectrum (MS) and nuclear magnetic resonance spectroscopy (NMR). The thermal stability of the synthesized carbazole derivatives was investigated by differential scanning calorimetry (DSC). The carbazole derivatives were added into the lubricating oil with a mass fraction of 0.8% and the miscibility, stability and oxidation resistance of the mixed system were evaluated by mechanical stirring and a rotary pressure vessel oxidation test (RPVOT). The DSC results showed that there was good thermal stability for the carbazole derivatives. The mechanical stirring method revealed good solubility and stability for the mixture of oil and carbazole derivatives. The RPVOT results showed that isopropyl carbazole derivatives could increase the oxidation induction period of lubricating oil to 1.39 times, and tert-butyl carbazole derivatives could increase the oxidation induction period of lubricating oil to 1.91 times. The antioxidant effect of tert-butyl carbazole derivatives was better than that of isopropyl carbazole derivatives.

Embedding electronic perpetual motion into single-atom catalysts for persistent Fenton-like reactions.

In our quest to leverage the capabilities of the emerging single-atom catalysts (SACs) for wastewater purification, we confronted fundamental challenges related to electron scarcity and instability. Through meticulous theoretical calculations, we identified optimal placements for nitrogen vacancies (Nv) and iron (Fe) single-atom sites, uncovering a dual-site approach that significantly amplified visible-light absorption and charge transfer dynamics. Informed by these computational insights, we cleverly integrated Nv into the catalyst design to boost electron density around iron atoms, yielding a potent and flexible photoactivator for benign peracetic acid. This exceptional catalyst exhibited remarkable stability and effectively degraded various organic contaminants over 20 cycles with self-cleaning properties. Specifically, the Nv sites captured electrons, enabling their swift transfer to adjacent Fe sites under visible light irradiation. This mechanism accelerated the reduction of the formed "peracetic acid-catalyst" intermediate. Theoretical calculations were used to elucidate the synergistic interplay of dual mechanisms, illuminating increased adsorption and activation of reactive molecules. Furthermore, electron reduction pathways on the conduction band were elaborately explored, unveiling the production of reactive species that enhanced photocatalytic processes. A six-flux model and associated parameters were also applied to precisely optimize the photocatalytic process, providing invaluable insights for future photocatalyst design. Overall, this study offers a molecule-level insight into the rational design of robust SACs in a photo-Fenton-like system, with promising implications for wastewater treatment and other high-value applications.

Characterization changes and research waste in randomized controlled trials of global bariatric surgery over the past 20 years: cross-sectional study.

BACKGROUND: The results of several large randomized controlled trials (RCTs) have changed the clinical practice of bariatric surgery. However, the characteristics of global RCTs of bariatric surgery have not been reported internationally and whether there was research waste in these RCTs is unknown. METHODS: Search ClinicalTrials.gov for bariatric surgery RCTs registered between January 2000 and December 2022 with the keywords 'Roux-en-Y gastric-bypass' and 'Sleeve Gastrectomy'. The above analysis was conducted in January 2023. RESULTS: A total of 326 RCTs were included in this study. The number of RCTs registered for sleeve gastrectomy and gastric bypass surgery increased year by year globally. Europe has always accounted for the largest proportion, Asia has gradually increased, and North America has decreased. A total of 171 RCTs were included in the analysis of waste, of which 74 (43.8%) were published. Of the 74 published RCTs, 37 (37/74, 50.0%) were judged to be adequately reported and 36 (36/74, 48.6%) were judged to have avoidable design defects. In the end, 143 RCTs (143/171, 83.6%) had at least one research waste. Body weight change as the primary endpoint (OR: 0.266, 95% CI: 0.103-0.687, P =0.006) and enrolment greater than 100 (OR: 0.349, 95% CI: 0.146-0.832, P =0.018) were independent protective factors for research waste. CONCLUSIONS: This study for the first time describes the characteristic changes of the mainstream RCT of bariatric surgery globally in the last 20 years and identifies a high research waste burden and predictive factor in this area, which provides reference evidence for carrying out bariatric surgery RCTs more rationally.

Magnetic Resonance Imaging and Serum AFP-L3 and GP-73 in the Diagnosis of Primary Liver Cancer.

Objective: To investigate the combined application value of magnetic resonance imaging (MRI) combined with serum alpha-fetoprotein (AFP)-L3 and Golgi protein (GP)-73 in the diagnosis of primary liver cancer. Methods: The data of 200 patients with suspected liver cancer admitted to our hospital from February 2020 to February 2021 were retrospectively analyzed, and they were randomly divided into an experimental group and a control group, with 100 cases in each group. The experimental group received a combined detection of MRI with serum AFP-L3 and GP-73, and the control group adopted traditional diagnostic methods (spiral computed tomography and serum AFP). The diagnostic yields of the two groups were compared. Surgical resection was performed after the diagnosis of primary liver cancer, and the correlation between the efficacy and combined detection of MRI with serum AFP-L3 and GP-73 levels was analyzed. Results: The two groups presented comparable general information (P >0.05). The surgical results showed 160 cases of primary liver cancer, including 75 cases in the experimental group and 85 cases in the control group, and 40 cases of benign liver lesions. The diagnostic accuracy of the experimental group (73/75, 95%) was significantly higher than that of the control group (76/85, 86%) (P < 0.05). The serum levels of AFP-L3, GP-73, and AFP in patients with primary liver cancer were remarkably decreased after surgery (P < 0.001). The preoperative and postoperative AFP-L3, GP-73, and AFP levels of patients with primary liver cancer were significantly higher than those of patients with benign liver lesions. The AUC (95% CI) for the combined detection of MRI and serum AFP-L3 and GP-73 levels in patients with surgically confirmed primary liver cancer was 0.747 (0.619-0.874). Conclusion: MRI combined with serum AFP-L3 and GP-73 presents favorable diagnostic efficiency in the diagnosis of primary liver cancer, which is worthy of clinical application.

[Expert consensus on the prevention and treatment of drowning in children].

Drowning is a leading cause of accidental injury in children and has a great impact on family and society. The prevention and treatment of drowning is of great importance for reducing mortality rate. This consensus reviews the literature on the epidemiology, rescue, resuscitation, and acute clinical management and prevention of drowning. The panel determines the score of available evidence according to the criteria of Oxford Centre for Evidence-Based Medicine and then makes recommendations on evidence based on such criteria, so as to provide a basis for further reducing the mortality and disability rates caused by drowning.

Developed a novel sensor based on fluorescent graft conjugated polymer for the determination of aristolochic acid in traditional Chinese medicine.

A novel fluorescent graft conjugated polymer (poly (2, 5-bis (Polyethylene glycol oxybutyrate)-1, 4-phenylethynylene-alt-1, 4-phenyleneethynylene, PPE-OB-PEG) has been designed and synthesized for the determination of aristolochic acid (AA). The detection conditions and detection characters of PPE-OB-PEG were systematically explored in this work. The fluorescence intensity of PPE-OB-PEG changes with the different concentration of AA. PPE-OB-PEG has a good linear range towards AA from 1.00 × 10-7 to 8.00 × 10-5 mol L-1 and the limit of detection (LOD) is 3.00 × 10-8 mol L-1 (S/N = 3). PPE-OB-PEG have been applied to detect AA in traditional Chinese medicine samples and the results are satisfactory. The experimental results show that PPE-OB-PEG can be used as a fluorescence probe for rapid and sensitive detection of AA.

Fluorescence chemical sensor for determining trace levels of nitroaromatic explosives in water based on conjugated polymer with guanidinium side groups.

A novel fluorescent conjugated polymer (poly(2-amino-N-(2-((4-ethynylphenyl) ethynyl) phenyl)-5-guanidinopentanamide)-1,4-phenylethynylene-1,4-phenyleneethynylene, PPE-Arg) was synthesized in this paper. We found that PPE-Arg could be quenched by picric acid (PA). Photoinduced electron transfer (PET) mechanism can be used to describe the fluorescence quenching of PPE-Arg. It could be speculated that the photo-induced electrons may be transferred from PPE-Arg to nitroaromatic explosives. In this paper, the experiment conditions and detection performance of PPE-Arg were systematically studied. The experiment results demonstrate PPE-Arg as a sensor for PA has a good linear range from 5 × 10-7 to 6 × 10-5 mol L-1 with the calculated limit of detection (LOD) to be 1.0 × 10-7 mol L-1. Meanwhile, reaction time between PPE-Arg and PA is less than 1 min. This proposed sensor was applied to rapidly detect nitroaromatic explosives in environmental water samples and satisfactory results were obtained.

Venomics reveals novel ion transport peptide-likes (ITPLs) from the parasitoid wasp Tetrastichus brontispae.

Despite substantial advances in uncovering constituents of parasitoid venoms due to their potential applications as insecticides and pharmaceuticals, most of these studies are primarily restricted to braconid and ichneumonid wasps. Little information is available regarding virulent factors from venom of Eulophidae. In order to provide insight into the venom components of this family and parasitoid venom evolution, a venom protein repertoire (venomics) of the endoparasitoid wasp, Tetrastichus brontispae was deciphered using a proteomic approach. A large number of diverse venom proteins/peptides were identified, including novel proteins and those proteins commonly found in the venoms of other parasitoids such as serine protease, esterase, dipeptidyl peptidase IV, acid phosphatase, major royal jelly protein, superoxide dismutase, and venom allergen 3/5. Three ion transport peptide-likes (ITPLs) were abundantly detected in T. brontispae venom. Of these, two of them are reported as a novel form for the first time, with the characteristics of lengthened amino acid sequences and additional cysteine residues. These venom ITPLs are obviously apart from other general members within the crustacean hyperglycemic hormone/ion transport peptide (CHH/ITP) family. It implies that they would evolve unique functions essential for parasitism success.

Residue analysis of tetracyclines in milk by HPLC coupled with hollow fiber membranes-based dynamic liquid-liquid micro-extraction.

A novel hollow fiber membranes-based dynamic liquid-liquid micro-extraction (HF-DLLME) coupled with HPLC-UV detection has been developed for the residue analysis of tetracyclines in milk samples without deproteinization and degreasing. The influences of experimental parameters were investigated and optimized. The method showed a good performance. The limits of detection (LOD) are in the range of 0.95-3.6µg/L. The recoveries in spiked samples range from 92.38 to 107.3%. The relative standard deviations (RSDs) are lower than 8.66%. The advantages of this method are simple operation, high efficiency, absence of sample carryover and low cost.

A prospective multicenter clinical study of extralevator abdominoperineal resection for locally advanced low rectal cancer.

BACKGROUND: Recent studies have shown that extralevator abdominoperineal resection has the potential for reduced circumferential resection margin involvement, intraoperative bowl perforation, and local recurrence rates; however, it has been suggested that extended resection may be associated with increased morbidity because of the formation of a larger perineal defect. OBJECTIVE: This study was undertaken to demonstrate the feasibility and complications of extralevator abdominoperineal resection for locally advanced low rectal cancer in China. DESIGN: This was a prospective cohort study. SETTING: The study was conducted at 7 university hospitals throughout China. PATIENTS: A total of 102 patients underwent this procedure for primary locally advanced low rectal cancer between August 2008 and October 2011. MAIN OUTCOME MEASURES: The main outcome measures comprised circumferential resection margin involvement, intraoperative perforation, postoperative complications, and local recurrence. RESULTS: The most common complications included sexual dysfunction (40.5%), perineal complications (23.5%), urinary retention (18.6%), and chronic perineal pain (13.7%). Chronic perineal pain was associated with coccygectomy (p < 0.001), and the pain gradually eased over time. Reconstruction of the pelvic floor with biological mesh was associated with a lower rate of perineal dehiscence (p = 0.006) and overall perineal wound complications (p = 0.02) in comparison with primary closure. A positive circumferential margin was demonstrated in 6 (5.9%) patients, and intraoperative perforations occurred in 4 (3.9%) patients. All circumferential margin involvements and intraoperative perforations were located anteriorly. The local recurrence was 4.9% at a median follow-up of 44 months (range, 18-68 months). LIMITATIONS: This was a nonrandomized, uncontrolled study. CONCLUSIONS: Extralevator abdominoperineal resection performed in the prone position for low rectal cancer is a relatively safe approach with acceptable circumferential resection margin involvement, intraoperative perforations, and local recurrences. Reconstruction of the pelvic floor with biological mesh might lower the rate of perineal wound complications (see Video, Supplemental Digital Content 1, http://links.lww.com/DCR/A161).

[Clinical characteristics of childhood leukemia with EVI1 gene and BCR/ABL gene co-expression].

OBJECTIVE: To study the clinical characteristics of ecotopic viral integration site-1 (EVI1) and BCR/ABL positive childhood leukemia. METHODS: Clinical data of four children with EVI1 and BCR/ABL positive leukemia and eight children with BCR/ABL positive but EVI1 negative chronic myeloid leukemia (CML) were retrospectively analyzed. RESULTS: In the four children with EVI1 and BCR/ABL positive leukemia, two were initially diagnosed with chronic phase of CML, one with accelerated phase of CML and one with high-risk acute lymphoblastic leukemia (ALL). There were no significant differences in clinical characteristics at diagnosis between the patients with EVI1 and BCR/ABL positive leukemia and BCR/ABL positive but EVI1 negative leukemia. CD33 and CD38 were highly expressed and t(9;22) abnormality was present in all patients with EVI1 and BCR/ABL positive leukemia. Two of the 3 children with EVI1 and BCR/ABL positive CML achieved complete remission one or three months after treatment. Acquired negative status conversion occurred for EVI1 but not BCR/ABL in one CML case. The 3 children with EVI1 and BCR/ABL positive CML survived 20, 13 and 14 months, respectively, without recurrence. The child with EVI1 and BCR/ABL positive ALL failed to achieve complete remission after the first course of treatment and discontinued further treatment. CONCLUSIONS: Co-expression of EVI1 and BCR/ABL fusion gene can be found in childhood CML and ALL. The relatively rare leukemia has not significant difference respect to clinical characteristics. Prognosis of the disease needs to be determined by clinical studies with a larger sample size.

[Clinical and biological characteristics of childhood acute myeloid leukemia with EVI1 gene positive expression].

OBJECTIVE: To study the expression of ecotropic viral integration site (EVI1) gene in childhood acute myeloid leukemia (AML) and the clinical features of EVI1-positive children with AML. METHODS: The clinical data of EVI1-positive children with AML were collected and analyzed. RT-PCR and real-time quantitative PCR were used for qualitative and quantitative analysis of expression of EVI1. Flow cytometry (FCM) was used for determining the immunophenotypes of bone marrow cells. Multiparameter FCM was used for monitoring minimal residual disease. The karyotypes were determined. RESULTS: Of 241 children with AML, 33 (13.7%) were positive for EVI1 expression. There were no significant differences in age at first visit as well as the white blood cell count, hemoglobin level, and platelet count in peripheral blood between EVI1-positive and EVI1-negative children with AML (P>0.05), but EVI1-positive children had a significantly increased proportion of females compared with EVI1-negative children (P<0.05). The change in EVI1 expression was not synchronous with clinical remission and the change of MRD: some children had clinical remission or negative conversion of MRD before negative conversion of EVI1, while some had negative conversion of EVI1 before clinical remission or while MRD showed positive. EVI1 gene was usually co-expressed with other fusion genes. CD33 (100%), CD38 (88%), and HLADR (76%) were highly expressed in EVI1-positive children with AML. Abnormal chromosome structure or number was found in 15 patients. Compared with EVI1-negative children, EVI1-positive children had significantly lower complete remission rates after the first course of treatment (P<0.05). CONCLUSIONS: EVI1-positive children with AML have a poor short-term prognosis. In the development of AML, the activation of EVI1 gene is not isolated, but the result of interactions with other genes or chromosome abnormalities, and the mechanism of activation and its function need further study.

Retrospective analysis of 119 cases of pediatric acute promyelocytic leukemia: Comparisons of four treatment regimes.

Clinical trials have demonstrated that pediatric acute promyelocytic leukemia (APL) is highly curable. Small-scale studies have reported on the treatment of APL using one or two treatment regimes. Here, we report a multiple center-based study of 119 cases of pediatric APL treated with four regimes based on all-trans-retinoic acid (ATRA). We retrospectively analyzed the clinical characteristics, laboratorial test results and treatment outcome of the pediatric APL patients. Regime 1 used an in-house developed protocol, regime 2 was modified from the PETHEMA LPA99 protocol, regime 3 was modified from the European-APL93 protocol, and regime 4 used a protocol suggested by the British Committee for Standards in Haematology. The overall complete remission rates for the four regimes were 88.9, 87.5, 97.1 and 87.5%, respectively, which exhibited no statistical difference. However, more favorable results were observed for regimes 2 and 3 than regimes 1 and 4, in terms of the estimated 3.5-year disease-free survivals, relapse rates, drug toxicity (including hepatotoxicity, cardiac arrhythmia, and differentiation syndrome) and sepsis. In conclusion, the overall outcomes were more favorable after treatment with regimes 2 and 3 than with regimes 1 and 4, and this may have been due to the specific compositions of regimes 2 and 3.

A report about treatment refusal and abandonment in children with acute lymphoblastic leukemia in China, 1997-2007.

BACKGROUND: To analyze the causes and consequence of treatment refusal and abandonment in childhood acute lymphoblastic leukemia (ALL) treated in Wuhan Union Hospital of China. METHODS: We collected recorded data and interviewed families of the children with ALL diagnosed between January 1997 and August 2007, who refused or abandoned treatment. RESULTS: 323 patients were diagnosed with ALL. 173 patients (173/323, 53.6%) refused therapy and 35 (35/323, 10.8%) cases abandoned treatment. 191 (191/208, 91.8%) of these children were telephone/mail-visited. Different people had different reasons for refusal or abandonment. Financial difficulty and belief of ALL incurability were the main reasons for abandonment. Transportation difficulties and fear of severe side effects were also important reasons. Of the 173 patients who refused treatment, 13 patients lost follow-up. 160 parents were interviewed and 1 (6.3%) child was still alive at the date of last follow-up. Of the 35 patients who abandoned treatment, 4 patients lost follow-up. 31 parents were interviewed and 2 (6.5%) children were still alive at the date of last follow-up. CONCLUSION: Medical insurance and a systemic health education are extremely required for childhood ALL in low middle income countries.

[Simulation of timber-harvesting area in Xiao Xing' anling Mountains under climate change].

By using the spatially explicit forest landscape model (LANDIS 6.0 PRO), the percentages of timber-harvesting area in Xiao Xing' anling Mountains under current harvesting scenario and under 11 harvesting scenarios with alternating harvesting intensities (alternating time was 10, 20 and 30 years, respectively) in 2000-2400 under climate change were simulated. Alternating harvesting intensity could increase the harvesting area. Comparing with current harvesting scenario, the simulated scenarios could increase the harvesting area by 3%-5% at short term (10-30 years), 2.5%-7% at medium term (40-60 years), and 3.5%-8% at long term (70-100 years). On the whole, the current total harvesting area was still high. Alternating harvesting-intensity could increase the harvesting area within a definite term, but the effect would be unsustainable. To have a sustainable development of forestry in the study area, it is necessary to reduce the harvesting intensity and change the forest management policy.

[Therapeutic effects of a combination of high-dose immunoglobulin and cyclosporine A in children with aplastic anemia].

OBJECTIVE: To evaluate the therapeutic effects of a combined immunotherapy, high-dose immunoglobulin (HDIG) plus cyclosporine A (CsA) plus prednisone (P), in children with aplastic anemia (AA) and to explore the association of peripheral blood lymphocyte subsets, peripheral blood cells and marrow CD34+ cells with therapeutic effects in AA. METHODS: The clinical data of 46 children with AA and who received the combined immunotherapy of HDIG + CsA + P were retrospectively studied. RESULTS: Of the 46 children with AA, 31 (67.4%) were responded to the combined immunotherapy. The binary logistic regression analysis showed low absolute neutrophil count (B=4.703, p<0.05), low percentage of peripheral blood CD4+ cells (B=0.142, p<0.05) and low ratio of peripheral blood CD4+/CD8+ (B=2.945, p<0.05)were associated with poor therapeutic effects. The ratio of CD34+/karyocytes of bone marrow in children with AA was lower than that in normal individuals, but it was not significantly related to the therapeutic effect. CONCLUSIONS: The combined immunotherapy (HDIG+CsA+P) was effective in children with AA. The absolute neutrophilcount, the percentage of peripheral blood CD4+ and the ratio of peripheral blood CD4+/CD8+ were important prognostic factors in AA.

[Effects of intrathecal ouabain and tizanidine injection for treatment of neuropathic pain in rats].

OBJECTIVE: To investigate the effects of intrathecal ouabain and tizanidine injection for treatment of neuropathic pain in rats. METHODS: Male SD rats weighing 250-300 g were randomly divided into 5 groups (n = 6), namely the control group, ouabain group, tizanidine group, combined ouabain and tizanidine injection group, and the antagonist group. Intrathecal catheter was implanted 7 days before spinal nerve ligation to establish the neuropathic pain model. Mechanical withdrawal threshold (MWT) before and after intrathecal administration of the agents was recorded in the rats. Isobolographic analysis was performed to evaluate the interactions between the agents. RESULTS: Intrathecal injection of ouabain (0.25-5 microg) or tizanidine (0.5-5 microg) alone produced dose-dependent analgesic effect against the neuropathic pain (P < 0.05). Isobolographic analysis revealed a synergistic interaction between ouabain and tizanidine. Intrathecal pretreatment with atropine (5 microg) or yohimbine (20 microg) antagonized the effects of ouabain and tizanidine administered alone or in combination (P < 0.05). CONCLUSION: Intathecal injection of ouabain or tizanidine produces dose-dependent analgesic effects against neuropathic pain, and their synergistic effect after combined injection probably involves the cholinergic transmission and alpha2 receptor.