BACKGROUND: Oral squamous cell carcinoma (OSCC) is a prevalent type of cancer with a high mortality rate in its late stages. One of the major challenges in OSCC treatment is the resistance to epidermal growth factor receptor (EGFR) inhibitors. Therefore, it is imperative to elucidate the mechanism underlying drug resistance and develop appropriate precision therapy strategies to enhance clinical efficacy. METHODS: To evaluate the efficacy of the combination of the Ca 2+ /calmodulin-dependent protein kinase II (CAMK2) inhibitor KN93 and EGFR inhibitors, we performed in vitro and in vivo experiments using two FAT atypical cadherin 1 ( FAT1 )-deficient (SCC9 and SCC25) and two FAT1 wild-type (SCC47 and HN12) OSCC cell lines. We assessed the effects of EGFR inhibitors (afatinib or cetuximab), KN93, or their combination on the malignant phenotype of OSCC in vivo and in vitro . The alterations in protein expression levels of members of the EGFR signaling pathway and SRY-box transcription factor 2 (SOX2) were analyzed. Changes in the yes-associated protein 1 (YAP1) protein were characterized. Moreover, we analyzed mitochondrial dysfunction. Besides, the effects of combination therapy on mitochondrial dynamics were also evaluated. RESULTS: OSCC with FAT1 mutations exhibited resistance to EGFR inhibitors treatment. The combination of KN93 and EGFR inhibitors significantly inhibited the proliferation, survival, and migration of FAT1 -mutated OSCC cells and suppressed tumor growth in vivo . Mechanistically, combination therapy enhanced the therapeutic sensitivity of FAT1 -mutated OSCC cells to EGFR inhibitors by modulating the EGFR pathway and downregulated tumor stemness-related proteins. Furthermore, combination therapy induced reactive oxygen species (ROS)-mediated mitochondrial dysfunction and disrupted mitochondrial dynamics, ultimately resulting in tumor suppression. CONCLUSION Combination therapy with EGFR inhibitors and KN93 could be a novel precision therapeutic strategy and a potential clinical solution for EGFR-resistant OSCC patients with FAT1 mutations.
Humans ; ErbB Receptors/metabolism* ; Mouth Neoplasms/metabolism* ; Cell Line, Tumor ; Animals ; Drug Resistance, Neoplasm/genetics* ; Cadherins/metabolism* ; Carcinoma, Squamous Cell/metabolism* ; Mice ; Mutation/genetics* ; Mice, Nude ; Protein Kinase Inhibitors/therapeutic use* ; Cetuximab/pharmacology* ; Afatinib/therapeutic use* ; Cell Proliferation/drug effects* ; Signal Transduction/drug effects*

OBJECTIVE: To explore the effects of two methods of smear layer removal on the surface properties of dentin. METHODS: Sixty extracted sound third molars were collected in this study, and were prepared as uniform dentin specimens with smear layer. All specimens were randomly divided into three groups: Control group, ultrasonic treatment (UT) group and etched treatment (ET) group. Scanning electron microscope (SEM) were used to observe the surface micromorphology of all three groups. Then, the surface elements, mineral phases and functional groups were analyzed by energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD) and flourier transformed infrared spectrometer (FTIR) respectively. The mechanical properties, hydrophilicity and biocompatibility were also further evaluated. RESULTS: It was revealed that dentin tubules of UT and ET groups were exposed, but lots of dentin debris piled up on the surface of the control one which covered up dentin tubules on the surface. The EDX results should that the weaker peak value of calcium and phosphorus in ET group than control and UT groups. Characteristic peaks of hydroxyapatite could be seen by XRD in all of the three groups, but lower distinctive peaks of amide Ⅰ, Ⅱ and Ⅲ bands of collagen of the dentin surface in control group than in ET and UT groups. The microhardness results showed that ET group was lower than control and UT groups, the difference was significant (P < 0.05). Better hydrophilicity of ET group was investigated (P < 0.05) than control group and UT group. Cells could be observed to adhere normally to dentin surface of each group which meant that all of the three groups had good biocompatibility. CONCLUSION Both UT and ET could effectively remove the smear layer on the surface of dentin and had no adverse effect of the dentin micromorphology and biocompatibility. The ultrasonic removal of the smear layer did not influence the mineral structure, hydrophilicity and mechanical properties of dentin surface. Although ET can effectively improve the hydrophilicity of dentin but decreased mechanical properties and the content of calcium and phosphorus.
Dentin/ultrastructure* ; Humans ; Surface Properties ; Smear Layer ; Molar, Third ; Microscopy, Electron, Scanning ; Dental Etching/methods*

Objective:To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.

Objective:To explore the clinical effects of early rehabilitation treatment after repair surgery of skin and soft tissue defects accompanied by extensor tendon injury on the back of hand.Methods:This study was a retrospective non-randomized controlled study. From February 2015 to February 2023, 24 patients (15 males and 9 females, aged 12-55 years) with skin and soft tissue defects accompanied by extensor tendon injury on the back of hand, who met the inclusion criteria and were repaired with flap transplantation and tendon grafting or tendon anastomosis, were admitted to the First Affiliated Hospital of Air Force Medical University. According to different intervention time for postoperative rehabilitation treatment of patients, the patients were divided into conventional rehabilitation group and early rehabilitation group, with 12 cases in each group. Patients in early rehabilitation group received rehabilitation treatment immediately after surgery under the rehabilitation guidance of specialized rehabilitation physicians based on the characteristics of different postoperative periods. Patients in conventional rehabilitation group began rehabilitation treatment from the third week after surgery, and their rehabilitation treatment was the same as that of patients in early rehabilitation group from the second week after surgery. The patients in 2 groups were treated in the hospital until the sixth week after surgery. The occurrence of flap vascular crisis and tendon rupture were observed within 6 weeks after surgery. After 6 weeks of surgery, the manual muscle test was used to measure the pinching force between the index finger and thumb, lateral pinching force, three-point pinching force, and grip force of the affected hand; the total action motion method was used to evaluate the finger joint range of motion of the affected hand, and the excellent and good ratio was calculated; the Carroll upper extremity function test was used to score and rate the function of the affected hand.Results:Within 6 weeks after surgery, only 1 patient in conventional rehabilitation group suffered from venous crisis, and the flap survived after the second surgical exploration and anastomosis of blood vessels; there was no occurrence of tendon rupture in patients of 2 groups. After 6 weeks of surgery, there were no statistically significant differences in pinching force between the index finger and thumb, lateral pinching force, three-point pinching force, or grip force of the affected hand between the two groups of patients ( P>0.05); the excellent and good ratio of the finger joint range of motion of the affected hand of patients in early rehabilitation group was 11/12, which was higher than 7/12 in conventional rehabilitation group, but there was no statistically significant difference ( P>0.05); the affected hand function score of patients in early rehabilitation group was 90±6, which was significantly higher than 83±8 in conventional rehabilitation group ( t=2.41, P<0.05); the function rating of the affected hand of patients in early rehabilitation group was obviously better than that in conventional rehabilitation group ( Z=2.04, P<0.05). Conclusions:Early rehabilitation treatment for patients with skin and soft tissue defects accompanied by extensor tendon injury on the back of hand after repair surgery can improve hand function, but it would not increase surgery related complications, which is worthy of clinical promotion and application.

Objective To compare the safety and efficacy of the da Vinci robot and thoracoscopic subxiphoid approach for the treatment of anterior mediastinal tumors. Methods The clinical data of patients who underwent anterior mediastinal tumor resection through the subxiphoid approach admitted to the same medical group in the Department of Thoracic Surgery of the First Hospital of Lanzhou University between June 2020 and April 2022 were retrospectively analyzed. According to the surgery approach, the patients were divided into a robot-assisted thoracoscopic surgery (RATS) group and a video-assisted thoracoscopic surgery (VATS) group. The perioperative data and the incidence of postoperative complications were compared between the two groups. Results A total of 79 patients were enrolled. There were 41 patients in the RATS group, including 13 males and 28 females, with an average age of 45.61±14.99 years. There were 38 patients in the VATS group, including 14 males and 24 females, with an average age of 47.84±15.05 years. All patients completed the surgery successfully. Hospitalization cost and operative time were higher or longer in the RATS group than those in the VATS group, and the difference was statistically significant (P<0.05). Intraoperative bleeding, postoperative hospital stay, postoperative water and food intake time, postoperative off-bed activity time, white blood cell count, neutrophil percentage and visual analogue scale (VAS) score on the first postoperative day, white blood cell count and neutrophil percentage on the third postoperative day, duration of analgesic pump use, the number of voluntary compressions of the analgesic pump, and mediastinal drainage volume were all superior to those in the VATS group (P<0.05). The differences in VAS scores on the third postoperative day, duration of drainage tube retention and postoperative complication rates were not statistically different between the two groups (P>0.05). Conclusion RATS subxiphoid anterior mediastinum tumor resection is a safe and feasible surgical method with less injury and higher safety, which is conducive to rapid postoperative recovery and has wide clinical application prospects.

BACKGROUND:Shujin Jiannao Prescription is an empirical formula for the treatment of cerebral palsy in Dongzhimen Hospital,Beijing University of Chinese Medicine,with clear clinical efficacy,but the specific mechanism needs to be elucidated. OBJECTIVE:To explore the possible mechanism of Shujin Jiannao Prescription in treating cerebral palsy. METHODS:Sixty-four 7-day-old Sprague-Dawley rats were randomly divided into a normal group(n=12)and a model group(n=52).An animal model was established by the Rice-Vannucci method.After successful modeling,52 model rats were randomly divided into control model group(n=12),minocycline group,and the low-,medium-,and high-dose groups of the Shujin Jiannao Prescription(n=10 per group).Rats in the minocycline group were given 40 mg/kg·d minocycline by gavage;rats in the low-,medium,and high-dose groups were given 4,8,and 16 g/kg·d Shujin Jiannao Prescription granules by gavage,respectively;and rats in the normal group and control model group were given an equal dose of normal saline by gavage.Medication in each group was given once a day for 1 week.The rats in each group were evaluated behaviorally using suspension test,abnormal involuntary movement score,and Bederson score.The pathological changes of the cerebral cortex were observed by hematoxylin-eosin staining.The levels of tumor necrosis factor α,interleukin 1β,and interleukin 10 in the cerebral cortex were determined using ELISA.The positive expressions of Janus kinase 2(JAK2),phosphorylated Janus kinase 2(p-JAK2),phosphorylated signal transducer and activator of transcription 3(p-STAT3)in the cerebral cortex were detected using immunohistochemistry.The protein expression levels of JAK2,p-JAK2,and p-STAT3 were detected using western blot. RESULTS AND CONCLUSION:Compared with the normal group,the suspension test score and involuntary movement score were decreased in the control model group(P＜0.01 or P＜0.05).The pathological results showed structural disruption of nerve cells,formation of large numbers of vacuoles,cell swelling,and increased intercellular space in the control model group.In addition,the expressions of tumor necrosis factor α and interleukin 1β in the cerebral cortex were significantly increased(P＜0.01),the expression of interleukin 10 was decreased(P＜0.05),and the protein expressions of JAK2,p-JAK2,and p-STAT3 in the cerebral cortex were significantly increased(P＜0.01)in the control model group compared with the normal group.Compared with the model group,minocycline and Shujin Jiannao Prescription at each dose could improve the behavioral indexes of rats(P＜0.01 or P＜0.05)and ischemic-hypoxic pathological changes were attenuated,with only a small amount of necrotic nerve cells and a few vacuoles,and reduced intercellular space.Moreover,the expressions of tumor necrosis factor α and interleukin 1β in the cerebral cortex were decreased in each drug group compared with the control model group(P＜0.05),while the protein expressions of JAK2,p-JAK2,and p-STAT3 in the cerebral cortex were significantly decreased(P＜0.01).The most obvious improvement was observed in the high-dose Shujin Jiannao Prescription group.To conclude,Shujin Jiannao Prescription can inhibit inflammation in the cerebral cortex of rats with hypoxic-ischemic brain injury.The mechanism may be related to the regulation of the JAK2/STAT3 signaling pathway.

OBJECTIVE:At present,there are many reports on the related factors associated with the incidence of cervical spine instability in patients with rheumatoid arthritis,but there are problems such as small sample size and many confounding factors,and the research results of various studies on the same related factors are also different.This article analyzed the factors related to cervical spine instability in patients with rheumatoid arthritis by means of a systematic review. METHODS:Articles related to cervical spine instability in patients with rheumatoid arthritis were collected by searching both Chinese and English databases until March 2023.The outcome of cervical spine instability in patients with rheumatoid arthritis was used as the grouping criterion to abstract basic information,baseline patient characteristics,laboratory-related tests,medication use,and other relevant risk factors.Meta-analysis was done using Stata 14.0 software. RESULTS:(1)Sixteen relevant studies,all of moderate or above quality,were included,including seven studies with case-control studies and nine with cross-sectional studies.The overall incidence of cervical spine instability in patients with rheumatoid arthritis was 43.08%.(2)Meta-analysis showed:Related risk factors included female(OR=0.60,95%CI:0.44-0.82,P=0.002);age at disease onset(SMD=-0.52,95%CI:-0.86 to-0.18,P=0.003);duration of disease(SMD=0.58,95%CI:0.14-1.02,P=0.01);body mass index(OR=0.74,95%CI:0.63-0.88,P=0.001);rheumatoid factors positive univariate analysis subgroup(OR=1.33,95%CI:1.02 to 1.72,P=0.04),C-reactive protein(SMD=0.26,95%CI:0.16-0.35,P=0.00),erythrocyte sedimentation rate(SMD=0.15,95%CI:0.002-0.29,P=0.047),anti-cyclic-citrullinated peptide antibodies(OR=1.73,95%CI:1.19-2.51,P=0.004),28-joint Disease Activity Score(SMD=0.20,95%CI:0.04-0.37,P=0.02),destruction of peripheral joints(OR=2.48,95%CI:1.60-3.85,P=0.00),and corticosteroids(OR=1.91,95%CI:1.54-2.37,P=0.00)were strongly associated with the development of rheumatoid arthritis-cervical spine instability.Female and corticosteroid use were independently associated with the occurrence of rheumatoid arthritis-cervical spine instability. CONCLUSION:Based on clinical evidence from 16 observational studies,the overall incidence of rheumatoid arthritis-cervical spine instability was 43.08%.However,the incidence of cervical spine instability in rheumatoid arthritis patients varied greatly among different studies.Gender(female)and the use of corticosteroids were confirmed as independent correlation factors for the onset of cervical spine instability in patients with rheumatoid arthritis.The results of this study still provide some guidance for early clinical recognition,diagnosis,and prevention of rheumatoid arthritis-cervical spine instability.

Objective To conduct a network meta-analysis on the effectiveness of first-line immunotherapy on patients with brain metastases from advanced non-small cell lung cancer(NSCLC).Methods Two investigators conducted a computerized search of Pubmed,Embase,Cochrane,and other databases to screen the literature,extract the information,and assess the risk of bias of the included studies.The included clinical trials were statistically analyzed using R(4.1.3)software.For the study outcome indicators OS and PFS,the risk ratios(HRs),and the 95%confidence intervals(CIs)were extracted from the included studies and logarithmically transformed into effect analysis statistics.Results Six randomized controlled trials were finally included,including 327 patients with non-excludable NSCLC brain metastases.Network meta-analysis suggested that PD-1 inhibitor+CTLA-4 was more advantageous than the conventional chemotherapy for enhancing patients'OS(HR:0.13,95%CI:0.03-0.71),followed by PD-L1 inhibitor(HR:0.17,95%CI:0.04-0.74)and PD-1 inhibitor+chemotherapy(HR:0.36,95%CI:0.2-0.63).PD-1 inhibitor+CTLA-4 was also more advantageous(HR:0.37,95%CI:0.15-0.93)than the conventional chemotherapy for boosting patients'PFS,followed by PD-L1 inhibitor+chemotherapy(HR:0.44,95%CI:0.29-0.66)and PD-1 inhibitor(HR:0.48,95%CI:0.27-0.86).Conclusion Immune checkpoint inhibitor therapy improves the survival of patients with brain metastases from advanced NSCLC.In particular,the combination of PD-1 inhibitor and CTLA-4 inhibitor show excellent survival benefit.

Objective:To investigate the incidence of postoperative complications in Chinese patients with gastric or colorectal cancer, and to evaluate the risk factors for postoperative complications.Methods:This was a national, multicenter, prospective, registry-based, cohort study of data obtained from the database of the Prevalence of Abdominal Complications After Gastro- enterological Surgery (PACAGE) study sponsored by the China Gastrointestinal Cancer Surgical Union. The PACAGE database prospectively collected general demographic characteristics, protocols for perioperative treatment, and variables associated with postoperative complications in patients treated for gastric or colorectal cancer in 20 medical centers from December 2018 to December 2020. The patients were grouped according to the presence or absence of postoperative complications. Postoperative complications were categorized and graded in accordance with the expert consensus on postoperative complications in gastrointestinal oncology surgery and Clavien-Dindo grading criteria. The incidence of postoperative complications of different grades are presented as bar charts. Independent risk factors for occurrence of postoperative complications were identified by multifactorial unconditional logistic regression.Results:The study cohort comprised 3926 patients with gastric or colorectal cancer, 657 (16.7%) of whom had a total of 876 postoperative complications. Serious complications (Grade III and above) occurred in 4.0% of patients (156/3926). The rate of Grade V complications was 0.2% (7/3926). The cohort included 2271 patients with gastric cancer with a postoperative complication rate of 18.1% (412/2271) and serious complication rate of 4.7% (106/2271); and 1655 with colorectal cancer, with a postoperative complication rate of 14.8% (245/1655) and serious complication rate of 3.0% (50/1655). The incidences of anastomotic leakage in patients with gastric and colorectal cancer were 3.3% (74/2271) and 3.4% (56/1655), respectively. Abdominal infection was the most frequently occurring complication, accounting for 28.7% (164/572) and 39.5% (120/304) of postoperative complications in patients with gastric and colorectal cancer, respectively. The most frequently occurring grade of postoperative complication was Grade II, accounting for 65.4% (374/572) and 56.6% (172/304) of complications in patients with gastric and colorectal cancers, respectively. Multifactorial analysis identified (1) the following independent risk factors for postoperative complications in patients in the gastric cancer group: preoperative comorbidities (OR=2.54, 95%CI: 1.51-4.28, P<0.001), neoadjuvant therapy (OR=1.42, 95%CI:1.06-1.89, P=0.020), high American Society of Anesthesiologists (ASA) scores (ASA score 2 points:OR=1.60, 95% CI: 1.23-2.07, P<0.001, ASA score ≥3 points:OR=0.43, 95% CI: 0.25-0.73, P=0.002), operative time >180 minutes (OR=1.81, 95% CI: 1.42-2.31, P<0.001), intraoperative bleeding >50 mL (OR=1.29,95%CI: 1.01-1.63, P=0.038), and distal gastrectomy compared with total gastrectomy (OR=0.65,95%CI: 0.51-0.83, P<0.001); and (2) the following independent risk factors for postoperative complications in patients in the colorectal cancer group: female (OR=0.60, 95%CI: 0.44-0.80, P<0.001), preoperative comorbidities (OR=2.73, 95%CI: 1.25-5.99, P=0.030), neoadjuvant therapy (OR=1.83, 95%CI:1.23-2.72, P=0.008), laparoscopic surgery (OR=0.47, 95%CI: 0.30-0.72, P=0.022), and abdominoperineal resection compared with low anterior resection (OR=2.74, 95%CI: 1.71-4.41, P<0.001). Conclusion:Postoperative complications associated with various types of infection were the most frequent complications in patients with gastric or colorectal cancer. Although the risk factors for postoperative complications differed between patients with gastric cancer and those with colorectal cancer, the presence of preoperative comorbidities, administration of neoadjuvant therapy, and extent of surgical resection, were the commonest factors associated with postoperative complications in patients of both categories.

Objective To investigate the clinical efficacy of arthroscopic simple repair technique and en-hanced repair technique in the treatment of chronic lateral ankle instability(CLAI).Methods Forty-one cases of CLAI treated in the General Hospital of Northern Theater Command of PLA from January 2018 to January 2019 were selected and conducted arthroscopic lateral ankle ligament repair or enhanced repair treatment.The follow up data in 39 cases were complete.Among them,18 cases conducted the anterior talofibular ligament repair with wire anchor under arthroscopy and were included in the repair group,while 21 cases conducted the arthroscopic enhanced repair with linear anchors and knots free anchors and were included in the enhanced re-pair group.The postoperative follow up lasted for 12 months.The VAS score and AOFAS ankle-hind foot score before operation and in postoperative,3,6,12 months were compared between the two groups.The effi-cacies of treating CLAI by the two operation modes were evaluated.Results The preoperative VAS score and AOFAS ankle-hind foot score had no statistical differences between the two groups(P＞0.05).The VAS score at postoperative time points had no statistical difference between the enhanced repair group and repair group(P＞0.05).The AOFAS ankle-hind foot score in the enhanced repair group was higher than that in the repair group,and the difference was statistically significant(P＜0.05).No serious complications occurred in the grouped patients during the follow up period.Conclusion In terms of pain and ankle function,the effect of arthroscopic enhanced repair in treating CLAI is better than that of simple repair.