BACKGROUND:Studies have shown that tibial plateau posterolateral fractures can be treated by posterolateral knee approach, however, there is no clear anatomical research to deeply evaluate and analyze this approach. OBJECTIVE:To evaluate the efficacy and safety of posterolateral knee inverted“L”shaped pathway in invloving tibial plateau posterolateral fractures. METHODS:Eight fresh frozen adult corpses, 16 knees side, were al dissected using posterolateral inverted“L”shaped pathway. During the dissection, the exposure range was observed and important parameters of anatomical structure were measured. RESULTS AND CONCLUSION:The pathway may be ful y exposed to the posterolateral aspect of tibial plateau and posterior cruciate ligament tibial insertions. The operations completed by out team did not create any obvious interference to superior tibiofibular joint, fibular head and posterolateral corner structure. The exposed mean length of common peroneal nerve in incision was 56.48 mm, with a mean angle of 14.7° tilt towards the axis of the fibula. The mean distance between the neck of the fibular and fibular head tip was 31.26 mm, an average of 42.18 mm to the joint line. The mean distance between the opening of the interosseous membrane and the articular surface was 48.78 mm. The divergence of the fibular artery from the posterior tibial artery was an average of 76.46 mm from articular surface. These results confirm that posterolateral inverted“L”shaped pathway met the requirements of anatomical reduction and buttress fixation for posterolateral tibial plateau fracture. Exposure of the common peroneal nerve can be minimized or even avoided by modifying the skin incision. Because the popliteal artery branches anterior tibial artery passed through interosseous membrane hole and peroneal artery and then separated from the posterior tibial artery, pathways dissection to distal deep area should be carried out careful y. Placement of a posterior buttressing plate carries a high vascular risk if the plate is implanted beneath these vessels.

Objective To study the value of flow cytometry in identifying metastatic CK positive and negative nonhematopoietic neoplasms in bone marrow. Methods Twenty-six cell lines representing ten epithelial neoplasms, one lymphoma cell line and one human T cell lymphoblast-like cell line were purchased from American Tissue Culture Collection. From July 2009 to June 2010, five nonhematopoietic neoplasms,fifteen hematopoietic neoplasms and fifteen control patients with complete remession after hematopoietic stem cell transplantation were collected in Beijing Daopei Hospital. Cryopreserved cell lines were thawed and cultured until they entered log phase. After permeabilization, cell lines were analyzed by staining with cytoplasmic CK-FITC antibody using four-color flow cytometer. The percent CK positivity was measured by comparing with negative control. Bone marrow samples were stained with membrane and cytoplasmic antibodies according to our routine methods. Based on lineage markers and blast markers as well as CK expression, the relevant hematopoietic diseases were diagnosed or excluded according to 2008 World Health Organization diagnosis standards. Results All epithelial neoplasm cell lines expressed CK, with average positive percentage 81.1%. All the lymphoid tumor cell lines didn't express CK. Two epithelial neoplasms were CK positive, 100. 0% in thyroid carcinoma and 98. 2% in lung carcinoma, respectively. Hematopoietic tumor and control samples didn't express CK. They expressed relevant hematopoietic markers, such as CD45 as well as lineage markers, or CD138 and cytoplasmic immunoglobulin light chain. Three nonepithelial nonhematopoietic neoplasms didn't express CK. CK positive or negative nonhematopoietic neoplasms didn't express hematopoietic markers such as CD45, HLA-ABC and HLA-DR DP DQ, as well as lineage specific markers. Besides, CK positive might be helpful to suggest epithelial origin. Conclusion Flow cytometry with hematopoietic markers and CK can effectively exclude hematopoietic tumor and identify metastatic CK positive and negative nonhematopoietic neoplasms in bone marrow.

Objective To evaluate the effect and potential risks of two types of materials ( taitanum versus polylevolactic acid,PLLA) screws on fixation of distal tibiofibular syndesmosis by a prospective randomized comparative clinical study.Methods From January 2007 to May 2008,48 patients with ankle fractures combined with a verified syndesmotic rupture were randomly allocated to receive either bioabsorbable PLLA (n =28 ) or titanium (n =20) screw fixation.The patients were assessed in aspects of radiography,function recovery and complication during follow-up.Results The total followup rate was 98％.The demographic information of the two groups showed no statistical difference ( P ＞0.05).After 1-2 years of follow-up,the indexes including Baird score,total score,and Baird grade were not statistically different between the two groups ( P ＞ 0.05).At the end of follow-up,there was significant difference in regard of joint motion between the injured and uninjured ankle in both groups ( P ＜0.05).Moderate rejection occurred in two patients and tibiofibular heterotopic ossification in two in PLLA group.Conclusions There is no significant difference between the bioabsorbable and metallic screws with regard to ankle function recovery,but the bioabsorbable screw fixation can avoid a second operation for taking out the screw.However,the complication risk of the bioabsorbable screws should not be ignored,such as rejection reaction,heterotopic ossification.

Polyethylene glycol (PEG) of different lengths were prepared to investigate their effects on oral absorption of nanostructured lipid carrier (NLCs).Three kinds of PEG-modified NLCs with different chain lengths, including polyethylene glycol (100) monostearate (S100), polyethylene glycol (55) monostearate (S55), polyethylene glycol (40) monostearate (S40), were prepared by film dispersion method.Coumarin 6 was chosen as a fluorescent probe to characterize the physicochemical properties of NLCs with different lengths.Meanwhile, the stability of NLCs in simulate buffer, the release behavior, cytotoxicity of NLCs, the uptake kinetics and cellular uptake mechanisms were evaluated. This work demonstrated that the thickness of the hydrated layer increased with the increase of PEG length. Of note, S100-modified NLCs (pNLC-EG100) exhibited higher cellular uptake efficiency compared with other formulations. Thus, S100 was optimized as the best molecular weight for PEG-modified NLCs on oral drug delivery system.

To construct nanostructured lipid carriers(NLCs)with different particle sizes but the same other physicochemical properties, central composite design was adopted. Coumarin-6(C-6)was selected as the model drug due to its high lipophilicity and high fluorescence intensity. Physicochemical properties of NLCs with 100 nm, 200 nm and 300 nm in particle size could remain stable during certain time in K-R solution and PBS. Release experiments in vitro showed that cumulative release of C-6 in NLCs was less than 7% after 24 h. The MTT assay indicated that both blank NLCs and C-6 loaded NLCs showed low toxicity. To confirm the integrity of NLCs in gastrointestinal tract, DiR-loaded NLCs were prepared and the distribution in vivo was monitored by fluorescence imaging. After 6 h oral administration, intact DiR-loaded NLCs could stiu be found, suggesting that NLCs could be used to characterize the uptake in gastrointestinal tract.

Objective:To explore the potential evidence of active peripheral nerve necrosis when n-hexane produces toxic effects on peripheral nerves.Methods:In May 2023, 36 SPF grade SD male rats with a body weight of 200-220 g were divided into 4 groups with 9 rats in each group and given normal saline and different doses of n-hexane (168, 675, 2 700 mg/kg) by gavage for 6 consecutive weeks (5 days/week). Three rats in each group were killed at the 2nd, 4th and 6th week, respectively. The spinal cord to sciatic nerve tissue was broken and the supernatant was extracted for SDS-PAGE protein isolation. The expression level of Sarm1 protein was analyzed with the β-Actin color strip of internal reference protein by Western blot. The expression of Sarm1 protein was analyzed by the gray ratio of the two. At the 6th week, the sciatic nerve sections of the each group were observed by light microscope and electron microscope.Results:The number of axons was obviously reduced by light microscopy. According to electron microscope, myelin lesions were mainly local disintegration, deformation, and different thickness. The deformation of axonal surface became smaller. The axons in the nerve bundle membrane showed degeneration and reduction. The gray ratio of Sarm1 protein and internal reference protein bands in each group had no significant change at the second week of exposure, and the ratio of SARM1 protein to internal reference protein bands was 1.47 in the high dose group at the fourth week, and 1.51 and 1.89 in the middle and high dose group at the sixth week, respectively.Conclusion:Waller's degeneration was observed in sciatic neuropathologic manifestations of n-hexane-poisoned rats, and the expression level of Sarm1 protein increased.

Objective:To explore the potential evidence of active peripheral nerve necrosis when n-hexane produces toxic effects on peripheral nerves.Methods:In May 2023, 36 SPF grade SD male rats with a body weight of 200-220 g were divided into 4 groups with 9 rats in each group and given normal saline and different doses of n-hexane (168, 675, 2 700 mg/kg) by gavage for 6 consecutive weeks (5 days/week). Three rats in each group were killed at the 2nd, 4th and 6th week, respectively. The spinal cord to sciatic nerve tissue was broken and the supernatant was extracted for SDS-PAGE protein isolation. The expression level of Sarm1 protein was analyzed with the β-Actin color strip of internal reference protein by Western blot. The expression of Sarm1 protein was analyzed by the gray ratio of the two. At the 6th week, the sciatic nerve sections of the each group were observed by light microscope and electron microscope.Results:The number of axons was obviously reduced by light microscopy. According to electron microscope, myelin lesions were mainly local disintegration, deformation, and different thickness. The deformation of axonal surface became smaller. The axons in the nerve bundle membrane showed degeneration and reduction. The gray ratio of Sarm1 protein and internal reference protein bands in each group had no significant change at the second week of exposure, and the ratio of SARM1 protein to internal reference protein bands was 1.47 in the high dose group at the fourth week, and 1.51 and 1.89 in the middle and high dose group at the sixth week, respectively.Conclusion:Waller's degeneration was observed in sciatic neuropathologic manifestations of n-hexane-poisoned rats, and the expression level of Sarm1 protein increased.

Objective:To analyze the clinical and laboratory characteristics of acute myeloid leukemia (AML) patients with NPM1 mutation, and to explore the prognostic factors.Methods:A total of 77 AML patients with NPM1 gene mutation admitted to Hebei Yanda Ludaopei Hospital from May 1st 2012 to December 31st 2021 were enrolled in the study, including 34 male and 43 female patients. The median age was 40 (3, 68) years old. Patients were selected and divided into 4 groups according to the morphological FAB classification. There were 29 cases (37.7%) of M1 type, 13 cases (16.9%) of M2 type, 23 cases (29.9%) of M4 type, and 12 cases (15.5%) of M5 type. The clinical characteristics, bone marrow/peripheral blood cell morphology, immunophenotype, cytogenetics, molecular biology and overall survival of different groups were retrospectively analyzed, and the risk factors affecting the prognosis of AML were also explored. Cox multivariate regression was used to analyze the clinical influencing factors of survival and prognosis.Results:The white blood cell counts were highest in M4 and M5 patients and lowest in M2 patients, while no significant difference in the red blood cell, hemoglobin, and platelet counts( P>0.05). Morphologically, there were significant differences in the percentage of blasts and blasts with cup-like nuclei on bone marrow (BM) and peripheral blood (PB). The proportion of blasts in BM and PB was the highest in M1 and the lowest in M2 ( P<0.001). The positive rate of blasts with cup-like nuclei was the highest in M1 and the lowest in M5 of BM ( P<0.001), while the highest in M2 and the lowest in M5 of PB ( P=0.006). The scores of myeloperoxidase and chloroacetate esterase were all the highest in M1 and the lowest in M5 ( P<0.001, 0.001, respectively). In terms of molecular biology, the occurence rate of blasts combined with DNMT3A mutation was the highest in M4 and the lowest in M2 ( P=0.044), while those combined with FLT3-ITD mutation was the highest in M4 and the lowest in M5 ( P=0.002). In immunophenotype, there were significant differences in the expression positivities of seven antigens including HLA-DR, CD56, CD11c, CD15, CD14, CD96 and cMPO ( P<0.05). Multivariate COX regression analysis showed that no recurrence after treatment ( P<0.001), complete remission after treatment ( P=0.015) and transplantation ( P<0.001) were correlated with overall survival (OS). No recurrence after treatment ( P=0.033), transplantation ( P=0.027), no mutation of FLT3-ITD ( P=0.040), and hemoglobin concentration ( P=0.023) were associated with relapse-free survival (RFS). Survival analysis by Kaplan-Meier curve showed that there was no significant difference in survival time between the M1, M2, M4 and M5 groups in OS and RFS. Conclusion:There were significant differences in the white blood count, the percentage of blasts and blasts with cup-like nuclear morphology, cytochemical staining (MPO integration, CE integration and percentage of NAS-DCE), gene mutation (DNMT3A and FLT3-ITD) and immunophenotypes (HLA-DR, CD56, CD11c, CD15, CD14, CD96 and cMPO) between the four groups. The multivariate analysis revealed that no recurrence after treatment and transplantation were independent prognostic factors in NPM1 mut AML patients. On the other hand, FLT3-ITD mutation and hemoglobin concentration were associated with RFS and complete remission after treatment was associated with OS in the entire NPM1 mut cohort.

Objective To compare the effectiveness and mechanical differences in the dynamic hip screw (DHS), proximal femoral nail antirotation (PFNA), and proximal femoral internal fixator (PFI) for fixing complex unstable proximal intertrochanteric fractures by biomechanical testing. Methods Eighteen Synbones of the proximal femur were made to simulate complex unstable femoral intertrochanteric fracture models (Evans-Jensen TypeⅢ), which were fixed by DHS, PFNA, and PFI, respectively. The models were tested using a biomechanical testing machine, in order to compare their differences and advantages for fixing fractures. Results Under the compressive loads of 300, 600, and 1 200 N, the fracture displacement of the DHS was the maximum, with a significant difference compared with PFNA and PFI (P<0.05). There were no significant differences between PFNA and PFI (P>0.05). Under torsional loads of 300, 600, and 1 200 N, the torsional displacements of DHS and PFNA at the fracture ends were the maximum, with no significant difference (P>0.05). There were significant differences between PFI and PFNA as well as PFI and DHS (P<0.05). Conclusions For complex unstable proximal intertrochanteric fractures, the stability of the compression resistance of the PFI system is similar to that of the PFNA system. However, the torsional resistance of PFI is stronger than that of PFNA. The DHS system shows the least resistance with respect to compression and torsion.

Objective:To investigate the diagnostic accuracy of serological indicators and evaluate the diagnostic value of a new established combined serological model on identifying the minimal hepatic encephalopathy (MHE) in patients with compensated cirrhosis.Methods:This prospective multicenter study enrolled 263 compensated cirrhotic patients from 23 hospitals in 15 provinces, autonomous regions and municipalities of China between October 2021 and August 2022. Clinical data and laboratory test results were collected, and the model for end-stage liver disease (MELD) score was calculated. Ammonia level was corrected to the upper limit of normal (AMM-ULN) by the baseline blood ammonia measurements/upper limit of the normal reference value. MHE was diagnosed by combined abnormal number connection test-A and abnormal digit symbol test as suggested by Guidelines on the management of hepatic encephalopathy in cirrhosis. The patients were randomly divided (7∶3) into training set ( n=185) and validation set ( n=78) based on caret package of R language. Logistic regression was used to establish a combined model of MHE diagnosis. The diagnostic performance was evaluated by the area under the curve (AUC) of receiver operating characteristic curve, Hosmer-Lemeshow test and calibration curve. The internal verification was carried out by the Bootstrap method ( n=200). AUC comparisons were achieved using the Delong test. Results:In the training set, prevalence of MHE was 37.8% (70/185). There were statistically significant differences in AMM-ULN, albumin, platelet, alkaline phosphatase, international normalized ratio, MELD score and education between non-MHE group and MHE group (all P<0.05). Multivariate Logistic regression analysis showed that AMM-ULN [odds ratio ( OR)=1.78, 95% confidence interval ( CI) 1.05-3.14, P=0.038] and MELD score ( OR=1.11, 95% CI 1.04-1.20, P=0.002) were independent risk factors for MHE, and the AUC for predicting MHE were 0.663, 0.625, respectively. Compared with the use of blood AMM-ULN and MELD score alone, the AUC of the combined model of AMM-ULN, MELD score and education exhibited better predictive performance in determining the presence of MHE was 0.755, the specificity and sensitivity was 85.2% and 55.7%, respectively. Hosmer-Lemeshow test and calibration curve showed that the model had good calibration ( P=0.733). The AUC for internal validation of the combined model for diagnosing MHE was 0.752. In the validation set, the AUC of the combined model for diagnosing MHE was 0.794, and Hosmer-Lemeshow test showed good calibration ( P=0.841). Conclusion:Use of the combined model including AMM-ULN, MELD score and education could improve the predictive efficiency of MHE among patients with compensated cirrhosis.