Comparison of double chevron-cut and biplanar distal femoral osteotomy techniques: A biomechanical study

OBJECTIVE

This study aimed to compare the stability and mechanical properties of the double chevron-cut (DCC) and biplanar (BP) distal femoral osteotomy (DFO) techniques, along with analyzing their respective contact surface areas.

METHODS

Biomechanical testing was performed using sawbone and 3D modeling techniques to assess axial and torsional stability, torsional stiffness, and maximum torque of both osteotomy configurations. Additionally, 3D models of the sawbone femur were created to calculate and compare the contact surface area of the DCC, BP, and conventional single-plane DFO techniques.

RESULTS

Axial stiffness and maximum strength did not significantly differ between the two osteotomy techniques. However, in terms of torsional properties, the DCC technique exhibited superior torsional stiffness compared to the BP group (27 ± 7.7 Nm/° vs. 4.5 ± 1.5 Nm/°, p = 0.008). Although the difference in maximum torque did not reach statistical significance (63 ± 10.6 vs. 56 ± 12.1, p = 0.87), it is noteworthy that the DCC group sawbone model exhibited fracture in the shaft region instead of at the osteotomy site. Therefore, the actual maximum torque of the DCC construct may not be accurately reflected by the numerical values obtained in this study. The contact surface area analysis revealed that the BP configuration had the largest contact surface area, 111% larger than that of the single-plane configuration. but 60% of it relied on the less reliable axial cut. Conversely, the DCC osteotomy offered a 31% larger contact surface area than the single-plane configuration, with both surfaces being weight-bearing.

CONCLUSION

The DCC osteotomy exhibited superior mechanical stability, showing improved rotational stiffness and maximum torque when compared to the BP osteotomy. Although the BP osteotomy resulted in a larger contact surface area than the DCC osteotomy, both were larger than the conventional single-plane configuration. In clinical practice, both the DCC and BP techniques should be evaluated based on patient-specific characteristics and surgical goals.

A clinical observational study of effectiveness of a solid coupling medium in extracorporeal shock wave lithotripsy

This study aimed to investigate clinical effectiveness of stone disintegration by using isolation coupling pad (“icPad”) as coupling medium to reduce trapped air pockets during extracorporeal shock wave lithotripsy (ESWL). Patients underwent ESWL between Oct. 2017 and May 2018 were enrolled in this clinical observational study. An electromagnetic lithotripter (Dornier MedTech Europe GmbH Co., Germany) was used in this study. Patients were divided into icPad group P1, P2 and semi-gel group C by different coupling medium. The energy level and total number of shock wave (SW) for group P1 and C was set at level 2 and 3000 and group P2 at level 3 and 2500. The successful stone disintegration rate (SSDR) was determined to evaluate the treatment outcome. All patients were evaluated by KUB film and ultrasonography after 90 days. Complications during ESWL were recorded. A total of 300 patients satisfied the inclusion criteria. There were no significant differences in characteristics of patients and stone among three groups. The corresponding SSDRs for patients in group P1, P2 and C was 73.0%, 73.2% and 55.3%, respectively. The SSDR in group P1 was statistically higher than Group C. Comparing to semi-liquid gel, coupling medium using by icPad could achieve better treatment outcome of stone disintegration in ESWL.

[The clinical application of blood routine and liver and kidney function test in COVID-19 disease prediction]

Objective: To explore the clinical application value of routine indicators such as blood routine and liver and kidney function in auxiliary diagnosis and prognosis of COVID-19 patients. Methods: SNK-q and other methods were used to retrospectively analyzed the differences of blood routine test, liver and kidney function and other inflammatory indexes of 30 patients with covid-19, 29 patients with other viral pneumonia, 35 patients with influenza A/B and 25 healthy persons from January 28 to February 14, 2020 in Xiangya Hospital of Central South University. Results: The neutrophils count increased gradually in COVID-19 group, influenza A/B group and other types of viral pneumonia group, and the difference between COVID-19 group and other viral pneumonia groups was statistically significant(H=-19.064,P<0.05); The lymphocyte count decreased gradually in the control group, influenza A/B group, other viral pneumonia group and COVID-19 group. In addition, DB, UA and GLU were also different among groups. Subgroup analysis showed that there were statistically significant differences in N(F=9.581,t=-0.152,P<0.05), N%(F=5.723,t=-0.600, P<0.05), NLR(F=4.773, t=-1.161, P<0.05), PCT(F=17.464, t=-1.477, P<0.05)and CRP(F=7.656, t=-1.973, P<0.05) between patients with lung involvement +-++ and patients with lung involvement +++-++++. There were statistically significant differences in NLR(F=63.931, t=-2.815, P<0.01), AST(F=15.704, t=-1.930, P<0.01), ALT(F=35.551, t=-2.199, P<0.01), LDH(F=7.715, t=-2.703, P<0.05) and GLU(F=6.306, t=-5.116, P<0.05) between the light+common subgroup and the heavy+critical subgroup of COVID-19 clinical classification. Correlation analysis showed that clinical stage and imaging credit period were significantly correlated with NLR (r=0.406, P=0.026; r=0.397, P=0.030), ALT (r=0.403, P=0.049; r=0.418, P=0.047), LDH (r=0.543, P<0.01; r=0.643, P<0.01) and GLU(r=0.750, P<0.01; r=0.471, P=0.042). A total of 5 principal components were extracted from all the included indicators, and the comprehensive information extraction rate was 82.86%. Indicators of a large load included Ur, PCT and CRP in PC1; ALT, AST and GLU in PC2; N%, L%, L and NLR in PC3. It indicated that the indicators of acute infection, liver function and blood routine had certein warning effect on disease surveillance. The results of ROC curve analysis showed that the combined detection of N+TB+Urea was the best practice to distinguish COVID-19 and other viral pneumonia, while the combined detection of N+L+UA was the most effective solution to make a distinction between COVID-19 and influenza A/B patients. In the aspect of disease evaluation, NL+LDH+GLU+ALT combined detection represent the best diagnostic performance to distinguish the clinical stage of light+common type and heavy+critical type, achieving the AUC (ROC) to 0.904, with the sensitivity 75% and the specificity 100% at the cut-off value of 0.477. Conclusion: In addition to etiology and imaging examination, doctors can also improve the routine laboratory tests such as blood routine test, liver and kidney function to assist diagnosis and disease prediction of patients with respiratory tract infection.

[Correlation between total cerebral small vessel disease score and retinal vessel diameters in patients with mild stroke]

Objective: To explore the relationship between the total cerebral small vessel disease (CSVD) score and retinal vessel diameters in patients with mild stroke. Methods: The patients with mild stroke who were hospitalized in the Second People's Hospital of Changzhou, Nanjing Medical University from March to December 2019 were continuously collected (National Institutes of Health Stroke Scale score≤3 points). All patients completed the head magnetic resonance imaging and retinal fundus photography examination, and then the retinal arteriovenous diameter was measured semi-automatically based on the pictures. According to the total CSVD score (0-4 points), the patients were divided into 5 groups. The baseline characteristics of the patients were compared. Moreover, the correlation of total CSVD with retinal blood vessel diameters were analyzed by spearman and linear regression. Results: A total of 206 patients were enrolled. There were 69, 51, 41, 30, and 15 patients with 0, 1, 2, 3, and 4 points, respectively. In CSVD subgroups, there were significant differences in age, duration of hypertension and diabetes (all P<0.05). The central retinal artery equivalent (CRAE), (CSVD scores 0-4 were (126±12) μm, (118±11) μm, (108±11) μm, (99±8) μm, (90±7) μm, P<0.001) and arteriole-to-venule ratio (AVR) (CSVD scores 0-4 were 0.65±0.05, 0.60±0.04, 0.56±0.04, 0.49±0.03, 0.44±0.02, P<0.001) were different in CSVD subgroups. With the increase of CSVD score, the diameter of artery and AVR became smaller. The total CSVD was significantly correlated with AVR by Spearman correlation analysis (r= 0.818, P<0.001). By constructing a linear regression equation model, the coefficient of determination of the total CSVD score (R²=0.694) was higher than that of lacunes, white matter hyperintensities, cerebral microbleeds and enlarged perivascular space. After adjusting for age, course of hypertension and diabetes, and different types of CSVD, further multiple linear regression analysis revealed that the total CSVD score was still an independent related factor of AVR (β=-0.039, P<0.001, 95%CI=-0.051--0.028). Conclusions: Total CSVD score is negatively correlated with retinal artery diameters and AVR. Additionally, the total CSVD score can better reflect the degree of cerebral microvascular lesions than single type CSVD.

[Effects of preoperative segmental mobility on the clinical and radiographic outcomes following one-level artificial cervical disc replacement]

Objective: To investigate the effects of preoperative segmental range of motion (ROM) on clinical and radiographical outcomes after artificial cervical disc replacement (ACDR) and explore whether ACDR could be indicated for patients with preoperative limited or excessive segmental ROM. Methods: From January 2008 to December 2017, patients who underwent Prestige-LP ACDR in West China Hospital were retrospectively reviewed. The preoperative and postoperative X-rays of the cervical spine were collected to measure the radiographic parameters, including cervical lordosis (CL), C(2-7) ROM, disc height (DH), disc angle (DA) and ROM at the arthroplasty level. Clinical outcomes were evaluated using the Japanese Orthopedic Association (JOA) and the Neck Disability Index (NDI) scores. The correlation between preoperative segmental ROM and postoperative clinical and radiographical outcomes were also analyzed. Results: A total of 161 patients were analyzed, with 73 males and 88 females. The mean age was (44±8) years, and the follow-up period was 34 months (12-120 months). JOA and NDI scores improved after ACDR (P<0.05). However, postoperative C(2-7) ROM and ROM at the arthroplasty level were comparable with preoperative counterparts (both P>0.05). Preoperative segmental ROM positively correlated with C(2-7) ROM and ROM at the arthroplasty segment (r=0.213、0.271, both P<0.05), but was negatively correlated with the change of ROM (r=-0.534, P<0.05). The segmental ROM was 4.0°±1.0° in the limited-ROM group (A) and 14.6°±1.3° in the excessive-ROM group (B), respectively. There were significantly more patients diagnosed with cervical spondylosis in group A than in group B (35.5% vs 10.7%, P<0.05). The level-distribution was statistically different between the two groups. C(5/6) and C(6/7) were prone to limited motion in group A, while C(4/5) and C(5/6) were predisposed to excessive motion in group B (all P<0.05). After surgery, C(2-7) ROM increased for 14.2°±16.8° in group A, while paradoxically decreased for 2.2°±14.4° in group B. However, C(2-7) ROM in group B was still larger than that in group A (P<0.05). Similarly, the ROM at the arthroplasty level increased by 3.1°±3.7° in group A, whereas the values decreased by 4.4°±4.2° in group B postoperatively. In addition, group A still had less segmental ROM than group B (P<0.05). The preoperative DH in group A was less than that in group B (P<0.05). The rates of ASD, HO, and high-grade HO in group A were all higher than those in group B but without significant differences (all P>0.05). Conclusion: Preoperative segmental ROM has no significant effects on clinical outcomes after ACDR; it has a positive correlation with postoperative global and segmental ROM while is negatively correlated with ROM change.

Epigenomic promoter alterations predict for benefit from immune checkpoint inhibition in metastatic gastric cancer

BACKGROUND

Utilization of alternative transcription start sites through alterations in epigenetic promoter regions causes reduced expression of immunogenic N-terminal peptides, which may facilitate immune evasion in early gastric cancer. We hypothesized that tumors with high alternate promoter utilization would be resistant to immune checkpoint inhibition in metastatic gastric cancer.

PATIENTS AND METHODS

Two cohorts of patients with metastatic gastric cancer treated with immunotherapy were analyzed. The first cohort (N = 24) included patients treated with either nivolumab or pembrolizumab. Alternate promoter utilization was measured using the NanoString® (NanoString Technologies, Seattle, WA, USA) platform on archival tissue samples. The second cohort was a phase II clinical trial of patients uniformly treated with pembrolizumab (N = 37). Fresh tumor biopsies were obtained, and transcriptomic analysis was carried out on RNAseq data. Alternate promoter utilization was correlated to T-cell cytolytic activity, objective response rate and survival.

RESULTS

In the first cohort 8 of 24 (33%) tumors were identified to have high alternate promoter utilization (APhigh), and this was used to define the APhigh tertile of the second cohort (13 APhigh of 37). APhigh tumors exhibited decreased markers of T-cell cytolytic activity and lower response rates (8% versus 42%, P = 0.03). Median progression-free survival was lower in the APhigh group (55 versus 180 days, P = 0.0076). In multivariate analysis, alternative promoter utilization was an independent predictor of immunotherapy survival [hazard ratio 0.29, 95% confidence interval 0.099-0.85, P = 0.024). Analyzing tumoral evolution through paired pre-treatment and post-treatment biopsies, we observed consistent shifts in alternative promoter utilization rate associated with clinical response.

CONCLUSION

A substantial proportion of metastatic gastric cancers utilize alternate promoters as a mechanism of immune evasion, and these tumors may be resistant to anti-PD1 immune checkpoint inhibition. Alternate promoter utilization is thus a potential mechanism of resistance to immune checkpoint inhibition, and a novel predictive biomarker for immunotherapy.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT#02589496.

Developing a reading concentration monitoring system by applying an artificial bee colony algorithm to e-books in an intelligent classroom

A growing number of educational studies apply sensors to improve student learning in real classroom settings. However, how can sensors be integrated into classrooms to help instructors find out students' reading concentration rates and thus better increase learning effectiveness? The aim of the current study was to develop a reading concentration monitoring system for use with e-books in an intelligent classroom and to help instructors find out the students' reading concentration rates. The proposed system uses three types of sensor technologies, namely a webcam, heartbeat sensor, and blood oxygen sensor to detect the learning behaviors of students by capturing various physiological signals. An artificial bee colony (ABC) optimization approach is applied to the data gathered from these sensors to help instructors understand their students' reading concentration rates in a classroom learning environment. The results show that the use of the ABC algorithm in the proposed system can effectively obtain near-optimal solutions. The system has a user-friendly graphical interface, making it easy for instructors to clearly understand the reading status of their students.

Effects of bone morphogenetic protein-6 on periodontal wound healing in a fenestration defect of rats

BACKGROUND

Bone morphogenetic proteins (BMPs) may play significant roles in bone formation. The ability of BMP-6 to promote wound healing has been chosen as the subject of this investigation. In this study, a synthetic rat BMP-6 polypeptide was applied to a periodontal fenestration defect in rats to elucidate the effects of BMP-6 on periodontal wound healing.

MATERIAL AND METHODS

Following surgery to create a bony window on the buccal aspects of mandibular molar roots, 24 male Sprague Dawley rats were divided into four groups according to BMP application (0, 1, 3 and 10 microg, respectively). Animals were killed after 28 days and the mandible taken for histological examination. Histometric measurements were performed on sections selected from three levels (coronal, middle and apical levels; with 240 microm apart from the central) of the defect. New bone and cementum formation (including area and thickness) were analyzed and compared.

RESULTS

In general, minimal new bone was observed on the surgically created defects in the non-BMP group, whereas a complete osseous healing occurred in all BMP-6 treated animals. New bone formation (both in area and thickness) was significantly influenced by both the dosage and the examining level, whereas new cementum formation was affected by dosage only. An increase in bone and cementum formation was noted in all three BMP groups when compared with the control group at all examined levels. Among the BMP groups, greatest new bone and cementum formation were noted in the 3 microg group. New cementum thickness increased on the cementum surfaces of the defects compared with the dentinal surfaces in all study groups.

CONCLUSION

An increase in new bone and cementum formation was noted after applying a synthetic BMP-6 polypeptide to a periodontal fenestration defect in rats. Therefore, we suggest that BMP-6 may play a certain role in periodontal regeneration.

Development of extended release dosage forms using non-uniform drug distribution techniques

Development of an extended release oral dosage form for nifedipine using the non-uniform drug distribution matrix method was conducted. The process conducted in a fluid bed processing unit was optimized by controlling the concentration gradient of nifedipine in the coating solution and the spray rate applied to the non-pareil beads. The concentration of nifedipine in the coating was controlled by instantaneous dilutions of coating solution with polymer dispersion transported from another reservoir into the coating solution at a controlled rate. The USP dissolution method equipped with paddles at 100 rpm in 0.1 N hydrochloric acid solution maintained at 37 degrees C was used for the evaluation of release rate characteristics. Results indicated that (1) an increase in the ethyl cellulose content in the coated beads decreased the nifedipine release rate, (2) incorporation of water-soluble sucrose into the formulation increased the release rate of nifedipine, and (3) adjustment of the spray coating solution and the transport rate of polymer dispersion could achieve a dosage form with a zero-order release rate. Since zero-order release rate and constant plasma concentration were achieved in this study using the non-uniform drug distribution technique, further studies to determine in vivo/in vitro correlation with various non-uniform drug distribution dosage forms will be conducted.