Low-dose hexavalent chromium induces mitophagy in rat liver via the AMPK-related PINK1/Parkin signaling pathway.

Hexavalent chromium (Cr(VI)) is a hazardous metallic compound commonly used in industrial processes. The liver, responsible for metabolism and detoxification, is the main target organ of Cr(VI). Toxicity experiments were performed to investigate the impacts of low-dose exposure to Cr(VI) on rat livers. It was revealed that exposure of 0.05 mg/kg potassium dichromate (K2Cr2O7) and 0.25 mg/kg K2Cr2O7 notably increased malondialdehyde (MDA) levels and the expressions of P-AMPK, P-ULK, PINK1, P-Parkin, and LC3II/LC3I, and significantly reduced SOD activity and P-mTOR and P62 expression levels in liver. Electron microscopy showed that CR(VI) exposure significantly increased mitophagy and the destruction of mitochondrial structure. This study simulates the respiratory exposure mode of CR(VI) workers through intratracheal instillation of CR(VI) in rats. It confirms that autophagy in hepatocytes is induced by low concentrations of CR(VI) and suggest that the liver damage caused by CR(VI) may be associated with the AMPK-related PINK/Parkin signaling pathway.

Biomechanical effects of different instrumented segments and trunk shifts on distal adjacent segments after congenital scoliosis posterior hemivertebrectomy: Preliminary results of a single case.

Objective: The present study aims to discuss the biomechanical effects of the sagittal vertical axis and different instrumented segments on distal adjacent segments after congenital scoliosis posterior hemivertebrectomy. Method: A case of congenital scoliosis caused by hemivertebra was selected for the reconstruction of the preoperative and postoperative 3D computed tomography data of the full spine. A finite element model of different fusion lengths and postoperative trunk shift (TS) values was established using the finite element method to compare the biomechanical effects of different models on the distal adjacent segment. Result: In the L1-L3 and T12-L1-L3-L4 fusion modes, the horizontal shift of the 1st vertebra below the lowest instrumented vertebra (LIV) increased with the trunk shift (TS) expansion after operation, and the imbalance between the left and right vertical stress of the 1st intervertebral disc below the LIV increased. With the decrease in fused segments in cases of TS = 10 mm and TS = 5 mm, the 1st vertebra below the LIV was subjected to a greater unbalanced force in the horizontal direction, and the 1st intervertebral disc below the LIV was subjected to a smaller imbalance between the left and right vertical stress after operation. Conclusion: When treating congenital scoliosis with hemivertebrectomy and pedicle screw fixation, fused segments can be properly extended and the postoperative TS shortened with a view of reducing the imbalance between the left and right stress of the 1st intervertebral disc below the LIV as well as the horizontal shift of the 1st vertebra below the LIV.

[Effects of PM2.5 and O3 sub-chronic combined exposure on ATP amount and ATPase activities in rat nasal mucosa].

OBJECTIVE: To evaluate the effects of fine particle matter (PM2.5) and ozone (O3) combined exposure on adenosine triphosphate (ATP) amount and ATPase activities in nasal mucosa of Sprague Dawley (SD) rats. METHODS: Twenty male SD rats were divided into control group (n=10) and exposure group (n=10) by random number table method. The rats were fed in the conventional clean environment and the air pollutant exposure system established by our team, respectively, and exposed for 208 d. During the exposure period, the concentrations of PM2.5 and O3 in the exposure system were monitored, and a comprehensive assessment of PM2.5 and O3 in the exposure system was conducted by combining self-measurement and site data. On the 208 d of exposure, the core, liver, spleen, kidney, testis and other major organs and nasal mucosal tissues of the rats were harvested. Each organ was weighed and the organ coefficient calculated. The total amount of ATP was measured by bioluminescence, and the activities of Na+-K+ -ATPase and Ca2+ -ATPase were detected by spectrophotometry. The t test of two independent samples was used to compare the differences among the indicator groups. RESULTS: From the 3rd week to the end of exposure duration, the body weight of the rats in the exposure group was higher than that in the control group (P < 0.05), and there was no significant difference in organ coefficients between the two groups. The average daily PM2.5 concentration in the exposure group was (30.68±19.23) µg/m3, and the maximum 8 h ozone concentration (O3-8 h) was (82.45±35.81) µg/m3. The chemiluminescence value (792.4±274.1) IU/L of ATP in nasal mucosa of the rats in the exposure group was lower than that in the control group (1 126.8±218.1) IU/L. The Na+-K+-ATPase activity (1.53±0.85) U/mg in nasal mucosa of the rats in the exposure group was lower than that in the control group (4.31±1.60) U/mg (P < 0.05). The protein content of nasal mucosa in the control group and the exposure group were (302.14±52.51) mg/L and (234.58±53.49) mg/L, respectively, and the activity of Ca2+-ATPase was (0.81±0.27) U/mg and (0.99±0.73) U/mg, respectively. There was no significant difference between the groups. CONCLUSION: The ability of power capacity decreased in the rat nasal mucossa under the sub-chronic low-concentration exposure of PM2.5 and O3.

Management of Nontraumatic Spontaneous Renal Hemorrhage (Wünderlich Syndrome) through Robotic-Assisted Laparoscopic Nephrectomy: A Case Series.

BACKGROUND Wünderlich syndrome (WS) is a rare diagnosis of nontraumatic spontaneous renal hemorrhage into the subcapsular, perirenal, or pararenal spaces. Prompt and effective intervention is necessary for an accurate pathological diagnosis and preservation of life. In the current literature, open surgery is the primary option when conservative treatment fails, but there can be serious trauma and corresponding consequences. Herein, we present 3 cases of Wünderlich syndrome managed by robot-assisted laparoscopic nephrectomy via a retroperitoneal approach. CASE REPORT Patient 1 was a 44-year-old woman with right flank pain for 6 h. Patient 2 was a 53-year-old woman with a history of diabetes who had pain in her right flank pain and nausea for 1 day. Patient 3 was a 45-year-old man with left flank pain for 1 day. All cases of WS were confirmed by CT. All 3 patients were treated with retroperitoneal robot-assisted nephrectomy after conservative treatment failed. Pathological examination confirmed that patient 1 had angiomyolipoma, and patients 2 and 3 had renal clear cell carcinoma. At the 9-month follow-up, renal function was good and no evidence of recurrence or metastasis has been detected. CONCLUSIONS These cases have highlighted the importance of the clinical history and imaging findings in the diagnosis of Wünderlich syndrome, and show that rapid management can be achieved using robot-assisted laparoscopic nephrectomy. However, it is crucial to have a skilled surgical team and adequate preoperative preparation.

Immune Regulation Patterns in Response to Environmental Pollutant Chromate Exposure-Related Genetic Damage: A Cross-Sectional Study Applying Machine Learning Methods.

Exposure to hexavalent chromium damages genetic materials like DNA and chromosomes, further elevating cancer risk, yet research rarely focuses on related immunological mechanisms, which play an important role in the occurrence and development of cancer. We investigated the association between blood chromium (Cr) levels and genetic damage biomarkers as well as the immune regulatory mechanism involved, such as costimulatory molecules, in 120 workers exposed to chromates. Higher blood Cr levels were linearly correlated with higher genetic damage, reflected by urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) and blood micronucleus frequency (MNF). Exploratory factor analysis revealed that both positive and negative immune regulation patterns were positively associated with blood Cr. Specifically, higher levels of programmed cell death protein 1 (PD-1; mediated proportion: 4.12%), programmed cell death ligand 1 (PD-L1; 5.22%), lymphocyte activation gene 3 (LAG-3; 2.11%), and their constitutive positive immune regulation pattern (5.86%) indirectly positively influenced the relationship between blood Cr and urinary 8-OHdG. NOD-like receptor family pyrin domain containing 3 (NLRP3) positively affected the association between blood Cr levels and inflammatory immunity. This study, using machine learning, investigated immune regulation and its potential role in chromate-induced genetic damage, providing insights into complex relationships and emphasizing the need for further research.

Polyoxometalate-Intercalated Tremella-Like CoNi-LDH Nanocomposites for Electrocatalytic Nitrite-Ammonia Conversion.

The electrocatalytic reduction of NO2- (NO2RR) holds promise as a sustainable pathway to both promoting the development of emerging NH3 economies and allowing the closing of the NOx loop. Highly efficient electrocatalysts that could facilitate this complex six-electron transfer process are urgently desired. Herein, tremella-like CoNi-LDH intercalated by cyclic polyoxometalate (POM) anion P8W48 (P8W48/CoNi-LDH) prepared by a simple two-step hydrothermal-exfoliation assembly method is proposed as an effective electrocatalyst for NO2- to NH3 conversion. The introduction of POM with excellent redox ability tremendously increased the electrocatalytic performance of CoNi-LDH in the NO2RR process, causing P8W48/CoNi-LDH to exhibit large NH3 yield of 0.369 mmol h-1 mgcat-1 and exceptionally high Faradic efficiency of 97.0% at -1.3 V vs the Ag/AgCl reference electrode in 0.1 M phosphate buffer saline (PBS, pH = 7) containing 0.1 M NO2-. Furthermore, P8W48/CoNi-LDH demonstrated excellent durability during cyclic electrolysis. This work provides a new reference for the application of POM-based nanocomposites in the electrochemical reduction of NO2- to obtain value-added NH3.

Relationships between blood chromium exposure and liver injury: Exploring the mediating role of systemic inflammation in a chromate-exposed population.

Hexavalent chromium and its compounds are prevalent pollutants, especially in the work environment, pose a significant risk for multisystem toxicity and cancers. While it is known that chromium accumulation in the liver can cause damage, the dose-response relationship between blood chromium (Cr) and liver injury, as well as the possible potential toxic mechanisms involved, remains poorly understood. To address this, we conducted a follow-up study of 590 visits from 305 participants to investigate the associations of blood Cr with biomarkers for liver injury, including serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), and direct bilirubin (DBIL), and to evaluate the mediating effects of systemic inflammation. Platelet (PLT) and the platelet-to-lymphocyte ratio (PLR) were utilized as biomarkers of systemic inflammation. In the linear mixed-effects analyses, each 1-unit increase in blood Cr level was associated with estimated effect percentage increases of 0.82% (0.11%, 1.53%) in TBIL, 1.67% (0.06%, 3.28%) in DBIL, 0.73% (0.04%, 1.43%) in ALT and 2.08% (0.29%, 3.87%) in AST, respectively. Furthermore, PLT mediated 10.04%, 11.35%, and 10.77% increases in TBIL, DBIL, and ALT levels induced by chromate, respectively. In addition, PLR mediated 8.26% and 15.58% of the association between blood Cr and TBIL or ALT. These findings shed light on the mechanisms underlying blood Cr-induced liver injury, which is partly due to worsening systemic inflammation.

Cellular senescence mediates hexavalent chromium-associated lung function decline: Insights from a structural equation Model.

There is sufficient evidence suggesting that exposure to hexavalent chromium [Cr(VI)] can cause a decline in lung function and the onset of lung diseases. However, no studies have yet explored the underlying mechanisms of these effects from various perspectives such as systemic inflammation, oxidative stress, and cellular senescence, simultaneously. This cross-sectional study was conducted among 304 workers engaged in chromate production and processing in China. Urine was used for detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and 8-iso-prostaglandin F2α (8-iso-PGF2α), while RNA and DNA extraction from peripheral blood cells was used for detection of mRNA, telomere length, and ribosomal DNA copy numbers (rDNA CNs). A 2.7-fold elevation in blood chromate (Cr) corresponded to a 7.86% (95% CI: 2.57%, 13.42%) rise in urinary 8-OHdG and a 4.14% (0.02%, 8.42%) increase in urinary 8-iso-PGF2α, indicating that exposure to chromates can cause oxidative stress. Furthermore, strong correlations emerged between blood Cr concentration and mRNA levels of P16, P21, TP53, and P15 in the cellular senescence pathway. Simultaneously, a 2.7-fold elevation in blood Cr associated with a -5.47% (-8.72%, -2.1%) change in telomere length, while rDNA CNs (5S, 5.8S, 18S, and 28S) changed by -3.91% (-7.99%, 0.34%), -9.4% (-15.73%, -2.6%), -8.06% (-14.01%, -1.69%), and -5.86% (-10.67%, -0.78%), respectively. Structural equation model highlighted that cellular senescence exerted significant indirect effects on Cr(VI)-associated lung function decline, with a mediation proportion of 23.3%. This study provided data supporting for 8-iso-PGF2α, telomere length, and rDNA CNs as novel biomarkers of chromate exposure, emphasizing the significant role of cellular senescence in the mechanism underlying chromate-induced lung function decline.

A rapid identification method for soft tissue markers of dentofacial deformities based on heatmap regression.

OBJECTIVE: The purpose of this study was to construct a facial deformity dataset and a network model based on heatmap regression for the recognition of facial soft tissue landmarks to provide a basis for clinicians to perform cephalometric analysis of soft tissue. MATERIALS AND METHODS: A 34-point face marker detection model, the Back High-Resolution Network (BHR-Net), was constructed based on the heatmap regression algorithm, and a custom dataset of 1780 facial detection images for orthognathic surgery was collected. The mean normalized error (MNE) and 10% failure rate (FR10%) were used to evaluate the performance of BHR-Net, and a test set of 50 patients was used to verify the accuracy of the landmarks and their measurement indicators. The test results were subsequently validated in 30 patients. RESULTS: Both the MNE and FR10% of BHR-Net were optimal compared with other models. In the test set (50 patients), the accuracy of the markers excluding the nose root was 86%, and the accuracy of the remaining markers reached 94%. In the model validation (30 patients), using the markers detected by BHR-Net, the diagnostic accuracy of doctors was 100% for Class II and III deformities, 100% for the oral angle plane, and 70% for maxillofacial asymmetric deformities. CONCLUSIONS: BHR-Net, a network model based on heatmap regression, can be used to effectively identify landmarks in maxillofacial multipose images, providing a reliable way for clinicians to perform cephalometric measurements of soft tissue objectively and quickly.

How many cases are required to achieving early proficiency in purely off-clamp robot-assisted partial nephrectomy?

Background and purpose: Off-clamp robot-assisted partial nephrectomy (Offc-RAPN) is a technically challenging procedure that can effectively avoid renal ischemia owing to the absence of hilar vessel preparation and clamping. However, data on the learning curve (LC) for this technique are limited. The purpose of this study was to assess the LC of Offc-RAPN and compare the perioperative outcomes between different learning phases. Methods: This retrospective study included 50 consecutive patients who underwent purely Offc-RAPN between January 2022 and April 2023. Multidimensional cumulative sum (CUSUM) analysis method was used to assess LC. Spearman's correlation and LOWESS analysis were performed to analyze the continuous variables of perioperative outcomes. Baseline characteristics and perioperative outcomes were compared using χ2-test, t-test and U-test. Results: CUSUM analysis identified two LC phases: phase I (the first 24 cases) and phase II (the subsequent 26 cases). Phase II showed significant reductions in mean operative time (133.5 vs. 115.31 min; p = 0.04), mean console time (103.21 vs. 81.27 min; p = 0.01), and mean postoperative length of stay (5.33 vs. 4.30 days; p = 0.04) compared to phase I. However, no significant differences were observed in other perioperative outcomes or baseline characteristics between the two LC phases. Conclusions: Offc-RAPN performed by a surgeon with experience in laparoscopic and robotic surgeries achieved early proficiency in 24 cases. Moreover, Offc-RAPN alone is safe and feasible even in the initial phase of the LC for an experienced surgeon.

Immunological CD4+ T-cell recovery and prognostic influencing factors in elderly HIV/AIDS patients of different genders after antiviral therapy / 中国热带医学

@#Objective　To investigate the prognostic influencing factors and recovery of CD4+ T lymphocytes in elderly HIV/AIDS patients after antiviral therapy by analyzing basic data and clinical follow-up data of elderly HIV/AIDS patients. Methods　The clinical data of 3 618 elderly AIDS patients aged ≥50 yeas who received antiretroviral therapy (ART) at HIV ART sites in Liuzhou City from 2005-2015 were collected. The data, including basic information, CD4+ T cell count, WHO clinical stage, infection route and follow-up, were retrospectively analyzed. Kaplan-Meier method was used to compare the differences in patient survival, multivariate Cox regression to analyze the independent influencing factors influencing the risk of death, and to compare the recovery of CD4+ T cell counts during follow-up of patients of different genders. Results　During the follow-up period, the 5-year cumulative survival rate up to the observation endpoint was 0.82 (female) and 0.66 (male). Multivariate logistic regression analysis showed that the risk factors affecting the effect of antiviral treatment were age (OR=1.909, 95%CI:1.474-2.464, P<0.001), body mass index (BMI) (OR=0.744, 95%CI: 0.574-0.965, P=0.026), opportunistic infections (OI) (OR=1.223, 95%CI:1.028-1.454, P=0.023), gender (OR=0.692, 95%CI:0.503-0.952, P=0.023) and baseline CD4+ T lymphocytes count (OR=0.563, 95%CI:0.429-0.739, P<0.001). Recovery of CD4+ T lymphocyte counts showed when baseline CD4+ T lymphocyte counts were less than 200 cells/mm3, older women with HIV/AIDS had higher CD4+ T lymphocytes than men at all times of ART treatment (P<0.05). Conclusions　Older women have a higher survival rate than older men after five years of antiviral therapy. Age, BMI, gender, OI and baseline CD4+T lymphocyte count may be important indicators that affect the survival of elderly HIV/AIDS patients. Older women showed better recovery of CD4+ T lymphocytes than older men during the 4-year follow-up period after ART.

Observation of early clinical efficacy of unilateral biportal endoscopy technique in the treatment of lumbar postoperative adjacent segmental diseases / 中国骨伤

OBJECTIVE@#To investigate early clinical efficacy of unilateral biportal endoscopy technique for the treatment of lumbar postoperative adjacent segmental diseases.@*METHODS@#Fourteen patients with lumbar postoperative adjacent segmental diseases were treated with unilateral biportal endoscopy technique from June 2019 to June 2020. Among them, there were 9 males and 5 females, aged from 52 to 73 years old, and the interval between primary and revision operations ranged from 19 to 64 months. Adjacent segmental degeneration occurred after lumbar fusion in 10 patients and after lumbar nonfusion fixation in 4 patients. All the patients received unilateral biportal endoscopy assisted posterior unilateral lamina decompression or unilateral approach to the contralateral decompression. The operation time, postoperative hospital stay and complications were observed. The visual analogue scale (VAS) of low back pain and leg pain, Oswestry Disability Index (ODI), modified Japanese Orthopaedic Association (mJOA) score were recorded before operation and at 3 days, 3 months, and 6 months after operation.@*RESULTS@#All procedures were successfully completed. Surgical duration ranged from 32 to 151 min. Postoperative CT showed adequate decompression and preservation of most joints. Out of bed walking 1 to 3 days after surgery, postoperative hospital stay was 1 to 8 days, and postoperative follow-up was 6 to 11 months. All 14 patients returned to normal life within 3 weeks after surgery, and VAS, ODI, and mJOA scores improved significantly at 3 days and 3, 6 months after surgery. One patient occurred cerebrospinal fluid leak after operation, received local compression suture, and the wound healed after conservative treatment. One patient occurred postoperative cauda equina neurologic deficit, which was gradually recovered about 1 month after rehabilitation therapy. One patients advented transient pain of lower limbs after surgery, and the symptoms were relieved after 7 days of treatment with hormones, dehydration drugs and symptomatic management.@*CONCLUSION@#Unilateral biportal endoscopy technique has a good early clinical efficacy in the treatment of lumbar postoperative adjacent segmental diseases, which may provide a new minimally invasive, non-fixation option for the treatment of adjacent segment disease.

The application of system epidemiology theory and methodology in occupational epidemiology / 中国职业医学

@#Abstract: Occupational epidemiology aims to explore the effect of occupational hazards on the health of workers and understand ， their mechanisms. It plays an important role in occupational health and occupational medicine.Currently occupational ， ， exposures in the workplace are complex and diverse and multiple factors affect workers´ health at the same time. Therefore it is important to elucidate the pathogenesis of occupational disease caused by occupational hazards and implement early - - intervention. System epidemiology collects data on multi level exposure and multi omics information to conduct network analysis - on the relationship amongrisk factors. and to study the mechanisms of exposures and health outcomes based on multi level data. ， ， ， ， Using the study design of system epidemiology occupational environmental lifestyle and social factors are combined as a ， system to evaluate the health of workers which can better evaluate the adverse health effects caused by occupational hazards. - ， ， The studies base on multi omics design will explore the pathogenesis of occupational diseases at the molecular cellular and tissue levels to evaluate the impact of occupational hazards on workers´ health and to explore interventions from multiple - perspectives to reduce the occurrence of occupational or work related diseases.

Case-control study on intrasacrospinal muscular approach and posterior midline approach for the treatment of far lateral lumbar disc herniation / 中国骨伤

<p><b>OBJECTIVE</b>To compare the clinical outcomes of intrasacrospinal muscular approach and posterior midline approach in treating far lateral lumbar disc herniation.</p><p><b>METHODS</b>The clinical data of 32 patients with far lateral lumbar disc herniation underwent transforaminal lumbar interbody fusion from January 2004 to January 2011 were retrospectively analyzed. The patients were divided into intrasacrospinal muscular approach group (11 males and 6 females ) and posterior midline approach group (10 males and 5 females). All patients were followed up from 12 to 18 months with an average of 15.3 months. Operative time, blood loss, postoperative draining volume were recorded and pre-and post-operative visual analog scale (VAS) and Oswestry Disability Index (ODI) were compared between two groups.</p><p><b>RESULTS</b>Operative time, blood loss, postoperative draining volume in intrasacrospinal muscular approach group was less than that of posterior midline approach group (P < 0.05). There was no significant difference in VAS at final follow-up between two groups (P > 0.05); and the mean ODI in intrasacrospinal muscular approach group was less than that of posterior midline approach group (P < 0.05).</p><p><b>CONCLUSION</b>For the treatment of far lateral lumbar disc herniation, intrasacrospinal muscular approach has less injury for paraspinal muscle and more satisfactory clinical outcome and is better method than posterior midline approach.</p>

The role of capsaicin-sensitive primary afferents in experimental sciatic pain / 中华外科杂志

<p><b>OBJECTIVES</b>To determine the effect of destroying capsaicin-sensitive primary afferents (CSPA) fibers on paw withdrawal mechanical threshold (PWMT) induced by the direct compression of L5 nerve root with autologous disc.</p><p><b>METHODS</b>The procedure used autologous disc of the rats from the coccygeal intervertebral discs to apply direct pressure to the L5 dorsal root. PWMT was measured at the different time points post-surgery and pre-surgery. The changes in spatial expression pattern of c-fos protein in the spinal cord were also determined at 3 weeks when PWMT decreased to the peak.</p><p><b>RESULTS</b>The pretreatment with capsaicin produced a complete prevention of mechanical hyperalgesia induced by disc compression. The direct compression of L5 nerve root produced an obvious expression of fos-like immunoreactivity neurons in the dorsal horn of the spinal cord, which was significantly decreased by pretreatment with capsaicin.</p><p><b>CONCLUSIONS</b>The study shows that CSPA fibers, which mainly terminated in superficial layers of dorsal horn, may play a key role in mechanical hyperalgesia in the new sciatica model.</p>

Effect on synthesis of nitric oxide in myocardium by local cryoablation / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To study the effect on synthesis of nitric oxide in myocardium by local cryoablation and to investigate its mechanism.</p><p><b>METHODS</b>Myocardium was cryoablated locally by a probe cooled to -60 degrees C and rewarmed by normal salt solution, nitric oxide and its synthesis enzyme were measured before and after cryoablation. L-arginine or methylene blue was added before and during cryoablation and the effect of these drugs on synthesis of nitric oxide was studied.</p><p><b>RESULTS</b>Nitric oxide and its synthesis enzyme decreased after cryoablation; L-arginine preserved the synthesis of nitric oxide and methylene blue inhibited the synthesis of nitric oxide. However, nitric oxide in serum did not change.</p><p><b>CONCLUSION</b>Nitric oxide and its synthesis enzyme in myocardium decrease after cryoablation.</p>

Mechanism of radiculopathy induced by experimentally herniated nucleus pulposus in rats / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the effects of the autologous nucleus pulposus on the pain-related behaviors of hind paws in rats.</p><p><b>METHODS</b>The nucleus pulposus harvested from autologous coccygeal vertebra was applied beside the unilateral L4 and L5 nerve roots without compression. The mechanical withdrawal threshold of both paws were measured in different times after surgery. And hematoxylin and eosin (HE) staining was applied to observe the changes of nucleus pulposus and nerve roots.</p><p><b>RESULTS</b>Mechanical sensitivity of the operated side in paws obviously increased after application of autologous nucleus pulposus beside the lumbar nerve roots without compression. And HE staining showed obviously inflammatory changes in the nucleus pulposus and vacuolation in the nerve roots.</p><p><b>CONCLUSIONS</b>Inflammation resulted from nucleus pulposus may contribute to the development of mechanical hyperalgesia. The results suggest that in addition to mechanical compression, inflammation may be an important factor in the pathogenesis of sciatica.</p>