The basement membrane is a specialized extracellular matrix between the epithelium and the mesenchyme.In stratified epithelium,only the basal cells in contact with the basement membrane exhibit the apical-basal polarity,whereas the epithelial cells do being not in contact with the basement membrane do not exhibit the apical-basal polarity.The basement membrane plays an important role in epithelial cell polarization.It is an important extracellular matrix(ECM)structure in the multicellular organisms,is situated between the epithelium and the mesenchyme,and is produced jointly by the epithelial cells and mesenchymal cells.Its components mainly include Laminin,type Ⅳ collagen(Col-Ⅳ),nidogen(NDG),and heparan sulfate proteoglycans(HSPG),and each component plays the different role in influencing the epithelial cell polarity.The network scaffold formed by Col-Ⅳ and Laminin is the main structure of the basement membrane,and the integrity of the structure affects the epithelial cell polarization.This review summarizes the composition and structure of the basement membrane,focuses on its role in epithelial cell polarization and its mechanism,and compiles the current status of biomimetic basement membrane materials that promotes the epithelial cell polarization,and provides the theoretical foundation for further exploration of the establishment and maintenance of epithelial cell polarity.

Objective To investigate clinical characteristics and risk factors of different stages of urinary tract infection after kidney transplantation.Methods Clinical data of 209 kidney transplant recipients were retrospectively analyzed.According to time points of postoperative follow-up,all recipients were divided into 3 stages:within 1 month post-kidney transplantation,1-6 months post-kidney transplantation,and 7-12 months post-kidney transplantation.The incidence of urinary tract infection,urine culture results of recipients with urinary tract infection and drug resistance characteristics of common pathogens during different stages after kidney transplantation were analyzed.The strains of patients with recurrent urinary tract infection were identified.The risk factors of urinary tract infection and the effect of urinary tract infection on renal allograft function were analyzed.Results The urinary tract infection rate was 90.0％in the first stage,49.3％in the second stage and 22.5％in the third stage.The urinary tract infection rates of male recipients undergoing living-related organ donation in the second and third stages were lower than those of female recipients(both P＜0.05).Urine culture test yielded positive results in 60 cases,and 84 strains of pathogenic bacteria were detected,mainly Gram-negative bacteria,among which Klebsiella pneumoniae accounted for the highest proportion.Sixty-six recipients had recurrent urinary tract infection,and the detected pathogens included Klebsiella pneumoniae,Escherichia coli and Candida glabrata,etc.Univariate analysis showed that postoperative use of antithymocyte globulin was the risk factor for urinary tract infection in the first stage.Preoperative urinary tract infection and donor type were the risk factors for urinary tract infection in the second stage.Gender and age of the recipients were the risk factors for urinary tract infection in the third stage.Multivariate analysis revealed that postoperative use of antithymocyte globulin was the risk factor for urinary tract infection in the first stage.Gender and age of the recipients were the risk factors for urinary tract infection in the third stage(all P＜0.05).In the third stage,65 cases were cured and 38 cases were not cured.In the treated recipients,the serum creatinine level and white blood cell count were decreased after corresponding treatment than those before treatment(both P＜0.05).Conclusions Gram-negative bacteria are the main pathogens of urinary tract infection in kidney transplant recipients,and drug resistance is relatively high.Postoperative use of antithymocyte globulin,female and old age are the risk factors for urinary tract infection in kidney transplant recipients.

Objective:To investigate the correlation between paroxysmal slow-wave events (PSWEs) and cerebral small vessel disease (CSVD) and CSVD-related cognitive impairment.Methods:Patients with CSVD visited Weihai Municipal Hospital from March 2021 to April 2022 were included, and sex- and age-matched healthy controls were recruited for cross-sectional analysis. The patients with CSVD were further divided into cognitive impairment group and non-cognitive impairment group. The self-developed Python script was used to detect the PSWE parameters in electroencephalogram records. Montreal Cognitive Assessment (MoCA) and Mini-Mental State Examination (MMSE) were used to evaluate cognitive function. Multivariate logistic regression analysis was used to determine whether PWSE parameters were the independent related factors of CSVD and CSVD-related cognitive impairment. Multiple linear regression analysis was used to determine the correlation between the PSWE parameters and overall cognitive function (MoCA total score) in patients with CSVD. Results:A total of 76 patients with CSVD (including 41 patients with cognitive impairment and 35 patients without cognitive impairment) and 45 healthy controls were included. Compared with the healthy control group, PWSEs in the F3 (left frontal area) and O1 (left occipital area) regions of the CSVD group occurred more frequently and lasted longer (all P<0.05). Multivariate logistic regression analysis showed that the frequency (odds ratio [ OR] 1.080, 95% confidence interval [ CI] 1.023-1.140; P=0.005) and duration ( OR 1.006, 95% CI 1.001-1.011; P=0.023) of PWSEs in the left frontal area, as well as the frequency ( OR 1.052, 95% CI 1.010-1.095; P=0.014) and duration ( OR 1.003, 95% CI 1.000-1.006; P=0.028) of PWSEs in the left occipital region were the independent related factors for CSVD. The frequency ( OR 1.106, 95% CI 1.033-1.183; P=0.004) and duration ( OR1.010, 95% CI 1.003-1.017; P=0.004) of PWSEs in the left frontal area were the independent risk factors for cognitive impairment in patients with CSVD. Multiple linear regression analysis showed that the frequency ( β= –0.242, P=0.045) and duration ( β= –0.235, P=0.046) of PWSEs in the left frontal region were negatively correlated with the overall cognitive function score in patients with CSVD. Conclusions:The frequency and duration of PSWEs in some brain regions of patients with CSVD increase, and there is an independent correlation between PSWEs and cognitive impairment, suggesting that the damage of blood-brain barrier may participate in the pathogenesis of cognitive impairment in patients with CSVD.

Objective:To compare the efficacy of 3D-printed guide plate assisted versus freehand placement of cannulated screws for the treatment of Sanders type II and III calcaneal fractures.Methods:A retrospective cohort study was conducted to analyze the clinical data of 29 patients with Sanders type II and III calcaneal fractures admitted to Chonggang General Hospital from June 2020 to October 2022. Among them, there were 18 males and 11 females, with an age range of 22-69 years [(40.1±11.5)years]. Nineteen patients were treated with individualized 3D-printed guide plate assisted placement of cannulated screws (3D-printed group) and 10 were treated with freehand placement of cannulated screws (freehand group). The surgical time, fluoroscopy times, postoperative 6-month calcaneal morphology (length, width, height, B?hler angle and Gissane angle), and American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and Maryland functional score assessed at 3, 6 months after operation and at the final follow-up were compared between the two groups. The incision healing and complications were observed.Results:The patients were followed up for 6-24 months [(11.3±2.5)months]. The surgical time and fluoroscopy times in the 3D-printed group were (53.4±9.1)minutes and (7.3±1.1)times, respectively, which were shorter than (90.2±16.0)minutes and (16.0±3.2)times in the freehand group (all P<0.01). At 6 months after operation, there was no significant difference in calcaneal length between the two groups ( P>0.05); the calcaneal width, height, B?hler angle and Gissane angle in the 3D-printed group [(34.0±1.8)mm, (47.2±1.6)mm, (27.8±1.0)°, (129.2±2.8)°] were superior than those in the freehand group [(37.5±2.0)mm, (43.0±2.7)mm, (25.8±1.5)°, (125.9±2.5)°] (all P<0.01). At 3, 6 months after operation and at the final follow-up, the values of AOFAS ankle-hindfoot score in the 3D-printed group [(72.2±2.3)points, (79.7±2.3)points, (86.5±4.4)points] were higher than those in the freehand group [(64.2±6.9)points, (73.4±4.2)points, (81.8±3.1)points] (all P<0.05); the values of Maryland score in the 3D-printed group [(71.4±7.7)points, (84.7±2.6)points, (91.5±2.5)points] were higher than those in the freehand group [(65.2±5.6)points, (79.1±3.8)points, (87.1±2.9)points] (all P<0.05). All surgical incisions were healed in stage I. In the 3D-printed group, there were no complications regarding infection, iatrogenic vascular or nerve injury, or fixation failure after surgery. In the freehand group, one patient with lateral sural cutaneous nerve injury was resolved spontaneously without specific treatment. Conclusion:Compared with freehand placement of cannulated screws, 3D-printed guide plate assisted placement of percutaneous placement has the advantages of shorter surgical time, fewer fluoroscopy times, lower reduction loss, better ankle joint function recovery, and less complications in treating Sanders type II and III calcaneal fractures.

Objective:To explore the efficacy and safety of TiRobot combined with three-dimensional imaging in the minimally invasive surgery for pelvic fractures.Methods:A retrospective analysis was conducted of the 40 patients with pelvic fracture who had been treated by fixation with S1 and S2 sacroiliac screws at Department of Orthopaedics and Traumatology, Yangjiang People's Hospital from January 2019 to May 2021. They were divided into 2 groups according to their treatment methods. In the TiRobot group of 20 cases subjected to percutaneous sacroiliac screw fixation assisted by TiRobot combined with three-dimensional imaging, there were 13 males and 7 females with an age of (38.2 ± 8.8) years. In the manual group of 20 cases subjected to fixation with manual placement of sacroiliac screws under conventional C-arm fluoroscopy, there were 11 males and 9 females with an age of (37.3 ± 9.2) years. The 2 groups were compared in terms of fluoroscopy time for screw placement, guide needle adjustment, operation time, intraoperative blood loss, visual analogue scale (VAS) 72 hours after operation, postoperative hospital stay, time to ambulation, excellent to good rate of screw placement, complication rate, fracture union time, Majeed score at 6 months after operation, and excellent to good rate of functional evaluation.Results:There was no significant difference between the 2 groups in their preoperative general data, showing they were comparable ( P > 0.05). In the TiRobot group, fluoroscopy time for screw placement [(8.2 ± 2.9) s], guide needle adjustment [(0.4 ± 0.2) times], operation time [(67.4 ± 5.5) min], and intraoperative blood loss [(36.5 ± 8.0) mL] were significantly less than those in the manual group [(40.4 ± 4.5) s, (8.6 ± 0.7) times, (78.4 ± 7.2) min, and (41.6 ± 7.8) mL], postoperative VAS [3.0 (4.0, 5.0) points] was significantly lower than that in the manual group [4.0 (5.0, 6.0) points], the excellent to good rate of screw placement (100%, 40/40) was significantly higher than that in the manual group (85.0%, 34/40), and the complication rate (5.0%,1/20) was significantly lower than that in the manual group (35.0%, 7/20) (all P < 0.05). There was no significant difference between the 2 groups in postoperative hospital stay, time to ambulation, fracture union time, Majeed score, or excellent to good rate of functional evaluation ( P > 0.05). Conclusion:In the minimally invasive surgery for pelvic fractures, TiRobot combined with three-dimensional imaging leads to positive outcomes, because it can reduce operation time and radiation exposure, improve accuracy of screw placement, and increase safety.

Thrombotic thrombocytopenic purpura (TTP) is a rare hematological disease with typical clinical manifestations of thrombocytopenic purpura, microangiopathic hemolytic anemia, neurological symptoms, fever and kidney damage. Two patients with TTP-associated cerebral infarction complicated with microhemorrhage and their shared specific imaging findings manifestations were reported. The magnetic resonance imaging of the 2 patients showed multiple cerebral infarctions at different stages. Susceptibility-weighted imaging showed cerebral microbleeds in the infarcted area. This special imaging feature can provide important clues for early identification and diagnosis of TTP nervous system injury.

Objective:To investigate the effect of the possibility of sleep-disordered breathing (SDB) as assessed by the four-variable score on the platelet function and the risk of stroke recurrence in patients with acute ischemic stroke.Methods:Patients with acute ischemic stroke admitted to the Department of Neurology, Weihai Municipal Hospital from January 2020 to January 2021 were enrolled prospectively. Main inclusion criteria: admission within 24 h of onset; National Institutes of Health Stroke Scale score ≤3; Receiving aspirin + clopidogrel dual antiplatelet therapy. All patients were divided into a high possibility group and a low possibility group of SDB according to the four-variable score. 7±2 d after dual antiplatelet therapy, PL-12 multi-parameter platelet function analyzer was used to detect the maximum aggregation rate (MAR). The patients were followed up for 6 months after discharge and the recurrence of ischemic stroke was observed. The mediating effect model was established with the high possibility of SDB as the independent variable, MAR as the intermediary variable and stroke recurrence as the dependent variable. Firstly, MAR as the dependent variable and high probability of SDB as the independent variable were analyzed by linear regression; then, a binary logistic regression analysis was performed with ischemic stroke recurrence as the dependent variable and the high probability of SDB and MAR as independent variables. Results:A total of 213 patients were enrolled in the study. The average age of the patients was 62.70 ± 10.04 years old. There were 146 male (68.5%) and 121 patients (56.8%) were in the high possibility group (56.8%). During the follow-up period, 24 patients (11.3%) had stroke recurrence. Univariate analysis showed that arachidonic acid (AA) induced MAR (MAR-AA) and adenosine diphosphate (ADP) induced the MAR (MAR-ADP) in the high possibility group of SDB were significantly higher than those in the low possibility group (all P<0.05); MAR-AA and MAR-ADP in the recurrent group were significantly higher than those in the non-recurrent group (all P<0.05), and the proportion of high possibility of SDB in the recurrent group was significantly higher ( P=0.008). Binary logistic regression analysis showed that homocysteine (odds ratio 1.132, 95% confidence interval 1.048-1.223; P=0.002) and having high possibility of SDB (odds ratio 6.351, 95% confidence interval 1.134-35.566; P=0.035) were the independent risk factors for stroke recurrence in patients treated with dual antiplatelet therapy. Intermediary effect analysis showed that MAR had a significant intermediary effect on the risk of stroke recurrence in patients with high probability of SDB. Conclusion:The MAR and stroke recurrence rates in the high possibility group of SDB were significantly higher than those in the low possibility group, and its stroke risk was probably mediated by platelet hyperreactivity.

Objective:To discuss the clinical curative effect of the minimally invasive percutaneous suture technique of eight times for repairing closed injury extensor tendon zone I of finger.Methods:From February 2017 to January 2020, 12 patients (male 8, female 4) with mallet finger deformity were retrospectively studied, with an average age of 35 years (range, 18-50 years). And all the affected fingers were acute closed rupture of extensor tendon in zone I of single finger, 5 cases of the left finger and 7 cases of the right finger. There were 1 case of the thumb finger, 2 cases of the index finger, 3 cases of the middle finger, 4 cases of the ring finger and 2 cases of the little finger. 12 patients with fresh sputum mallet fingers were with 3-0 thread monofilament suture on extensor tendon zone I of finger in the minimally invasive percutaneous suture technique of eight times, and the distal end of the tendon was fixed to the base of the distal phalanx through the bone hole. Removal of the Kirschner wire 6-8 weeks, the brace was used to fix the affected finger in the dorsal extension. The flexion and extension of the affected finger was gradually strengthened. The function of the affected finger was evaluated according to the Crawford standard after operation and follow-up. The active flexion and extension range of motion of each joint of the affected finger and the contralateral healthy finger were measured, and the total action movement (TAM) of the finger were recorded. Finger function was evaluated according to TAM of the American Association of Hand Surgeons.Results:All operations were successfully completed, the operation time of the patients ranged from 18 to 25 min, with an average of 20.1±0.2 min. There was only a small amount of bleeding in the surgery. All 12 cases were followed up and the follow-up periods ranged from 6 to 14 months, with an average of 10.2±1.1 months. Mallet finger deformities were all corrected postoperatively; there were no knot exposure, skin necrosis and other complications. According to the Crawford standard, 9 cases were excellent, 2 cases were good, and 1 case was fair. The excellent and good rate was 91.7% (11/12). The mean active flexion of distal interphalangeal joints on the wounded finger and healthy finger were 82.11°±2.02° and 84.09°±2.01°, the mean active extension of distal interphalangeal joints on the wounded finger and healthy finger were -2.04°±3.01° and 0.02°±1.02°, there were significant differences between them ( t=2.447, 3.246; P=0.019, 0.004). The degrees of active joint activity of wounded finger were: 91.02°±4.01° of the metacar-pophalangeal joint, 94.04°±2.11° of the proximal interphalangeal joint, 83.01°±2.02° of the distal interphalangeal joint, and 265.05°±13.04° of total active activity; the degrees of active joint activity of healthy finger were: 93.01°±3.21° of the metacar-pophalangeal joint, 94.03°±3.07° of the proximal interphalangeal joint, 85.02°±2.01° of the distal interphalangeal joint, and 269.02°±12.10° of total active activity. The TAMs of the healthy side were 269.02°±12.10°, and the TAMs of the affected side were 265.05°±13.04°, there was no significant difference between them ( P>0.05). According to TAM system assessment criteria: excellent in 9 patients, good in 3 patients, and the excellent and good rate was 100% (12/12). Conclusion:The minimally invasive percutaneous suture technique of eight times can well repair closed injury extensor tendon zone I of finger, can have satisfactory treatment outcome in mallet finger with a simple procedure and good outcome. It is a simple, safe, effective method with minimal invasion.

Objective:To investigate the correlation between heart rate variability (HRV) and cerebral small vessel disease (CSVD) in patients with obstructive sleep apnea (OSA).Methods:Patients with OSA received polysomnography and brain MRI examination in Weihai Municipal Hospital from July 2019 to July 2020 were consecutively collected for cross-sectional analysis. The 5 min HRV before sleep (awake state) was analyzed. The patients were divided into CSVD group and non-CSVD group according to the overall burden of CSVD. The demographic data, clinical data, polysomnography parameters and HRV time domain and frequency domain parameters were compared between the two groups. Multivariate logistic regression analysis was used to determine the correlation between the HRV parameters and CSVD in patients with OSA. Results:A total of 100 patients with OSA were enrolled, including 79 males (79.0%), aged 52.36±8.66 years, apnea hypopnea index (AHI) 38.70±24.65/h. There were 46 patients (46.0%) in the CSVD group and 54 (54.0%) in the non-CSVD group. Univariate analysis showed that there were significant differences in age, AHI, oxygen desaturation index (ODI), percentage of blood oxygen saturation <90% in total sleep time (T90), square root of the mean of the sum of the squares of the difference between adjacent RR intervals (RMSSD), power in high frequency range (HF), power in low frequency range (LF) to HF ratio (LF/HF) between the CSVD group and the non-CSVD group (all P<0.05). Multivariate logistic regression analysis showed that after adjusting for age, body mass index, systolic blood pressure, AHI, ODI, and T90, RMSSD (odds ratio 0.625, 95% confidence interval 0.389-0.981; P=0.041) and LF/HF ratio (odds ratio 1.429, 95% confidence interval 1.011-2.020; P=0.043) were the independent influencing factors of CSVD in patients with OSA. Conclusion:Increased LF/HF and decreased RMSSD in OSA patients with CSVD suggest that the increased sympathetic excitability and decreased vagus function, which may be one of the pathophysiological mechanisms of occurring CSVD in patients with OSA.

Objective:To investigate the distant metastasis after primary treatment of papillary thyroid cancer (PTC) in children and adolescents.Methods:A retrospective analysis of 180 cases (54 boys and 126 girls, with an age range of 6-18 years) with PTC treated at the Chinese Medical Academy Cancer Hospital and Zhejiang Cancer Hospital from January 1, 2001 to December 31, 2014 was performed. Patients’ clinical and pathological data were collected. The follow-up results were statistically analyzed. The distant metastasis rate during the follow-up period was analyzed by the Kaplan-Meier method. Log-Rank test was used for univariate analysis and Cox regression model was established in multivariate analysis.Results:Twenty-four cases (13.3%) had distant metastases during following-up with a median of 92 months. The Log-Rank test showed that the younger age ≤15 years old (χ 2=11.803, P=0.001), the larger tumor diameter >20 mm (χ 2=5.776, P=0.016), multifocal (χ 2=11.205, P=0.001), bilateral tumor distribution (χ 2=19.804, P=0.001), invaded capsule (χ 2=10.808, P=0.001), and bilateral lymph nodes metastasis (χ 2=6.278, P=0.012) were risk factors for distant metastasis after initial treatment. The Cox regression analysis showed that age ≤15 years (hazard ratio [95% confidence interval]: 4.08[1.504-11.111], P=0.006) and bilateral tumor distribution (hazard ratio [95% confidence interval]: 4.77[1.903-11.966], P=0.001) were independent risk factors for distant metastasis after initial treatment. The risk factors for local recurrence and distant metastasis were similar, but the local recurrence could not be a significant predictor for distant metastasis. It was indicated that distant metastasis rate was lower in patients with total thyroidectomy in multifocal lesions groups (χ 2=5.891, P=0.015). Conclusions:Age, tumor size, invaded capsule, bilateral lymph nodes metastasis, multifocal and bilateral lesions are factors for predicting distant metastasis after primary treatment of PTC in children and adolescents. Total thyroidectomy is recommended for patients with multifocal and bilateral lesions.