BACKGROUND:Effects of pedicle screw placement on fracture reduction or stability of mechanics are influenced by various factors. Pedicle screw fixation failure is mainly due to fracture, loosening and fatigue. The main influential factors for biomechanical stability of pedicle screw are length and diameter. The research on the depth is less. OBJECTIVE:To analyze the relationship between pedicle screw placement depth of vertebral body and the fixed stability based on the biomechanics. METHODS: A model of single vertebral compression fractures was made in 15 pigs aged 5 months on L2 vertebral specimen. According to the length of anteroposterior diameter, vertebral pedicle screws were inserted in different depths (80%, 90% and 100% of anteroposterior diameter). After fixation, specimens were loaded 10 000 times at the frequency of 0.5 Hz (340±125) N on a WDT-10KN type universal material testing machine. Ranges of motion at anteflexion, backward extension, left bending and right bending and the maximum axial pulout force were measured in each group, and the difference of intergroup data was compared. RESULTS AND CONCLUSION:(1) Ranges of motion at anteflexion, backward extension, left bending and right bending in each group were significantly smaler in the 100% and 90% groups than in the 80% group (P < 0.05), and above parameters were smaler in the 100% group than in the 90% group (P< 0.05). (2) After fatigue test, the maximum axial pulout force was significantly larger in the 100% and 90% groups than in the 80% group (P< 0.05), and above data were significantly larger in the 100% group than in the 90% group (P < 0.05). (3) Results indicate that the depth into the vertebral body was significantly associated with its fixed stability. The deeper the depth into the vertebral body, the stronger the vertebral stability was: 100% group > 90% group > 80% group.

Objective To detect the expression of type Ⅰ interferon in monocyte-derived dendritic cells(MoDCs)after Toll like receptor(TLR)3 triggered in patients with chronic hepatitis B(CHB),and to evaluate immune responses of CHB patients and its roles in the mechanisms of persistent infection of hepatitis B virus(HBV)and chronicity of hepatitis.Methods Peripheral blood mononuclear cells(PBMCs)were isolated and purified using magnetic beads(plasma was saved simultaneously)from 26 CHB patients and 18 healthy volunteers(HV).Dendritic cells(DCs)were induced and proliferated in a culture medium with recombinant human granulocyte macrophage colony stimulating factor(rhGM-CSF)and recombinant human interleukin(rhIL-4).EX3s were stimulated with Poly Ⅰ:C and the supernatants were collected at 0 h and 24 h after stimulation.Type Ⅰ interferon(IFN-α and IFN-β)in plasma and supernatants were examined by enzyme linked immunosorbent assay (ELISA).Results The levels of type Ⅰ interferon in plasma were not significantly different in groups of HV and CH B.IFN-α and IFN-β expressions in supernatants before Poly Ⅰ:C stimulation were(80.00±16.15)ng/L,(36.39±13.90)ng/L in CHB group and(76.76±15.90)ng/L,(37.14±13.68)ng/L in HV group,respectively.And there were no statistical differences between two groups(t=1.651,t=0.178;both P＞0.05).IFN-α expressions in supernatants at 24 h after stimulation in two groups were both higher than those before stimulation(at 0 h),but there were no statistical differences(t=1.534,t=1.243;both P＞0.05).IFN-β expressions in supernatants at 24 h after stimulation in HV group was(54.57±16.80)ng/L,which was significantly higher than that at 0 h(37.14±13.68)ng/L(t=4.061,P＜0.05).However,there was no significant difference at 24 h than tht at 0 h in CHB group(t=1.796,P＞0.05).At 24 h after stimulation.IFN-β level was(54.57±16.80)ng/L in HV group,which was significantly higher than that[(41.64±12.57)ng/L]in CHB group(t=2.921,P＜0.05).Conclusions Functions of MoDCs from CHB patients are impaired and MoDCs could not express type Ⅰ interferon normally.Expression of type Ⅰ interferon after TLR3 triggered in CHB patients is mainly IFN-β.

Objective To elucidate the expression of Toll-like receptor 3 (TLR3) on dendritic cells(DCs) in patients with chronic hepatitis B (CHB), and to explore the correlation between hepatitis B virus (HBV) persistent infection and TLR3 expression. Methods Sixty CHB patients (CHB group) and 20 healthy controls (control group) were enrolled. The peripheral blood mononuclear cells (PBMCs) were isolated and CD14~+ monocytes were sorted by immunomagnetic beads. Immature DCs (imDC) were induced and proliferated in vitro and mature DCs (mDC) were obtained after the poly I:C stimulation. The expression of intracellular TLR3 mRNA was detected by real-time polymerase chain reaction (PCR), and surface markers [CD80 and human leucocyte antigen (HLA)-DR] were determined by flow cytometry after 48 h of stimulation. The comparison of quantitative data was done using t test. The qualitative data were compared using chi-square test.Results The mean fluorescence intensities (MFI) of intracellular TLR3 of imDC before poly I:C stimulation in CHB group and control group were 1212.05 ± 250.80 and 1192.95 ± 301.40,respectively, which were not significantly different (t = 0. 280, P>0. 05). While after stimulation,those were 1352.98± 313.67 and 1593. 00± 349. 65, respectively, the latter was significantly higher than the former (t = 2. 880, P<0. 05). The levels of TLR3 mRNA inside mDCs in both groups were increased after poly I:C stimulation, which were 0. 1204 ±0.0267 and 0. 1780 ± 0.0664, respectively in CHB group and control group, and that in control group was significantly higher (t = 3. 909, P<0.05). Furtherly, patients in CHB group were divided into HBeAg(+ ) and HBeAg( -) subgroups.After stimulation, the MFI and mRNA of TLR3 inside mDC were greatly elevated in both subgroups,but there were no difference between these two subgroups (t = 0. 366, P>0. 05). Conclusions The intracellular expressions of TLR3 in mDC in CHB group and control group are obviously increased after the poly I:C stimulation, but the increased level in CHB group is lower than that in control group. The results suggest that the insufficiency of TLR3 synthesis may be related to the HBVpersistent infection.

BACKGROUND:The distal tibia shaft fracture is prone to be comminuted after trauma due to the absence of muscle covering and the thin soft tissue, and intraoperative reduction and fixation are difficult. Clinical efficacy is closely related to the type of fracture, degree of soft tissue injury, choice of therapy and internal fixation. Internal fixation is the main treatment for the distal tibia shaft fracture, and a microinvasive, strong fixation is the focus of tibial fracture treatment although many methods for internal fixation are present. ＜br> OBJECTIVE:To explore clinical efficacy of the treatment of distal tibia shaft fracture using percutaneous locking compression plate, interlocking intramedul ary nail and open reduction with internal fixation. ＜br> METHODS:A total of 180 patients with distal tibia shaft fracture were randomized into three groups, receiving internal fixation treatment using percutaneous locking compression plate, interlocking intramedul ary nail or open reduction. Al patients were fol owed up for 12-24 months. The clinical outcomes of the treated patients in three ＜br> groups were compared through the observations of incision length, operation time, intraoperative fluoroscopy time, intraoperative blood loss, complications after fixation. ＜br> RESULTS AND CONCLUSION:After excluding the loss of fol ow-up, 56 cases receiving percutaneous locking compression plate, 52 cases receiving interlocking intramedul ary nail and 48 cases receiving open reduction were involved in the final analysis. The incision length and intraoperative blood loss in the groups of percutaneous locking compression plate and interlocking intramedul ary nail were significantly better than that of open reduction (P＜0.05). Intraoperative fluoroscopy time in the group of percutaneous locking compression plate was significantly longer than that in other two groups (P＜0.05). The operation time showed no significant differences among three groups. The rate of complications was 11%in the group of percutaneous locking compression plate, and 27%in the groups of interlocking intramedul ary nail and open reduction with internal fixation. Percutaneous locking compression plate is a good choice for the distal tibia shaft fracture due to smal injury, good biomechanical stability, and no influence on blood supply at fracture end;interlocking intramedul ary nail is also a useful technique due to simple operations. Open reduction with internal fixation should be chosen careful y due to great dissection, great influence on blood supply and high complication rate.

Objective To understand the immune regulatory function of monocyte-derived dendritic cells (MoDC) in patients with chronic severe hepatitis B (CSHB) and its roles in the severe illness progression of chronic hepatitis B (CHB) by detecting surface phenotype of MoDC and expression level of cytokines in MoDC after polyl : C treatment. Methods The peripheral blood mononuclear cells (PBMC) were isolated by Ficoll density gradient separation from 37 patients with CSHB, 20 patients with CHB, and 20 healthy controls (NC). Purified PBMC were acquired using immunomagnetic anti-CD14-beads. Then PBMC were induced to immature dendritic cell (iDC) in vitro. PolyI : C was added to induce DC maturation. The mean fluorescence intensity (MFI) of the phenotype marker molecules including HLA-DR, CD83, CD86 and CD80 on surface of iDC and mature DC (mDC) were detected by flow cytometry. The supernatants of MoDC culture were collected at 12,24 and 48 h after polyI : C treatment, respectively and the release levels of interleukin (IL)-12, IL-6and tumor necrosis factor (TNF)-α were determined by enzyme linked immunosorbent assay (ELISA). Comparisons among groups were done by single factor analysis of variance and homogeneity of variance was tested. Results There were no significant differences of phenotype marker molecules on cell surface of iDC, including HLA-DR, CD83, CD86 and CD80 in CSHB, CHB and NC groups.However, the expressions of HLA-DR, CD83, CD86 and CD80 on cell surface of mDC in CSHB group were lower than those in CHB and NC groups (F=59.73, 13.95, 34.80 and 73.02, respectively; all P＜0. 05). The secretions of IL-12 at three time points of 12 h, 24 h and 48 h after polyI : C treatment in group NC were higher than those in CHB and CSHB groups (F= 151.34, 126.65 and 72.76, respectively; P＜0.05), and peaked at 24 h which were (48.2±7.6), (56.7±11.8) and (97.8±16.2) ng/L, respectively. The secretions of IL-6 at the above three time points were CSHB＞CHB＞NC (F=92.50, 86.89 and 64.57, respectively; all P＜0. 05) and peaked at 12 h which were (1698.3±340.4), (965.8±231.7), (697.8±213.6) ng/L, respectively. The secretions of TNF-αat the above three time points were CSHB＞CHB＞NC (F=58.66, 122.36 and 44.73, respectively;all P＜0. 05) and were (19 672. 7±4214. 7), (9946. 1 ± 2586 5), (6659. 2±955. 8) ng/L,respectively at 24 h after treatment. Conclusions MoDCs of CSHB patients show mature defection and abnormal cytokine secretion. The expression level of IL-12 which mediates cellular immune is low.Meanwhile, the productions of IL-6 and TNF-α which mediate inflammatory response are up-regulated. This may be one of the major factors which lead to exacerbation of liver inflammation and ultimately development of severe hepatitis.

From the status quo of medical and health services in rural areas,there exist the following problems:the insufficient number of clinicians,low quality of clinicians,the imbalance of the professional ranks and titles,and aging.Based on investigation and analysis of the rural community health technicians of Huzhou City,Zhejiang Province,the author put forward the new countermeasures of orientation training clinicians in rural communities according to the rural communities residents new demand for medical and health services.

Objective:To construct a new reporter mycobacteriophage, ΦFN, based on a nanoluciferase (Nluc) reporter system, and to analyze its ability to detect drug resistance in Mycobacterium tuberculosis ( Mtb). Methods:A Nluc reporter system controlled by P furAma promoter was constructed and integrated into Mycobacterium smegmatis ( Msm) genome to assess its reporting ability in mycobacteria. Then the P furAma- nluc reporter system was integrated into TM4 mycobacteriophage genome to construct a new phage termed ΦFN. A rapid procedure for detecting drug resistance in mycobacteria using ΦFN was established by adjusting conditions such as drug exposure time and time of infection. The susceptibility of 52 clinical isolates of Mtb with known drug resistance to three first-line anti-tuberculosis drugs were tested in 96-well plates. Results:The recombinant Msm mc 2155 expressing P furAma- nluc repoerter system could generate luminescence signal at a low limit of 100 colony-forming unit (CFU), which was lower than the previously reported nluc system controlled by Pleft promoter. The detection limit of ΦFN for mycobacteria reached 100 CFU within 24 h by luminescent microplate reader. After 48 h of antibiotic exposure and 24 h of phage incubation, no luminescence signal could be detected when susceptible strains were below 10 5 CFU, which could effectively distinguish susceptible strains and rapidly detect drug resistance. The drug susceptibility of 52 clinical isolates of Mtb to rifampin, isoniazid and streptomycin was tested using ΦFN, and the accuracy was 51/52, 48/52 and 49/52, respectively, by using the conventional drug susceptibility test, Lwenstein-Jensen culture medium assay, as reference. Conclusions:The new recombinant luminescent reporter phage, ΦFN, showed high accuracy in detecting the drug susceptibility of Mtb to rifampicin, isoniazid and streptomycin and it only took three days. It is expected to be a new simple assay for the rapid detection of drug susceptibility of Mtb.

Objective:To investigate the clinical characteristics of de novo malignancies (DNMs) after liver transplantation (LT) and to study the clinical management strategies.Methods:Adult LT recipients who were regularly followed-up in the Organ Transplantation Center, the Affiliated Hospital of Qingdao University from January 2005 to April 2021 were enrolled in this study. The clinical characteristics of DNMs were retrospectively analyzed. Of 601 LT recipients, there were 105 females and 496 males, aged (51.4±9.6) years old. They were divided into the DNMs group ( n=26) and the non-DNMs group ( n=575) according to whether there were DNMs on followed-up. Clinical data including age, sex, basic diseases before LT and operation time were collected. These patients were follow-up in outpatient clinics. Results:Twenty-six patients were diagnosed to develop DNMs after LT, but there were 28 DNMs (of which 2 patients were diagnosed to have DNMs twice). The incidence of DNMs after LT was 4.3% (26/601), the median time from LT to DNMs was 42 (20, 70) months, and the cumulative incidence rates of DNMs were 0.5%, 2.0%, 6.3%, 21.0% and 34.5% at 1, 3, 5, 10 and 15 years after LT, respectively. Among the 28 DNMs, digestive system tumors were most common, with 17 lesions (60.7%), followed by 3 lesions (11.1%) of lung cancer, 2 lesions (7.4%) of lymphoproliferative diseases, and 1 lesion (3.7%) of cervical cancer, thyroid cancer, soft palate cancer, eyelid cancer, laryngeal cancer, and prostate cancer. The follow-up time of 55.9 (36.6, 102.5) months in the DNMs group after LT was longer than the 33.4 (18.5, 58.9) months in the non-DNMs group ( P<0.001). The 1, 5, and 10 year survival rates of patients with DNMs after LT were 96.3%, 83.5%, and 49.8%, respectively. The 1, 5, and 10 year survival rates of patients with non-DNMs after LT were 94.5%, 77.7%, and 75.4%, respectively. There was no significant difference in the cumulative survival rates between the two groups (log rank=0.402, P=0.526). Conclusion:The incidence of DNMs in LT recipients was 4.3%. The majority of them were digestive system tumors. Early diagnosis and treatment of DNMs significantly improved the prognosis and quality of life of these patients.

Hepatocellular carcinoma is a common malignant disease in clinical practice, and portal vein tumor thrombosis (PVTT) is one of the important factors affecting the prognosis of hepatocellular carcinoma. PVTT has strong oncologic characteristics and is highly susceptible to extrahepatic metastasis, complicating portal hypertension, leading to gastrointestinal bleeding or liver failure and causing death. In this paper, we review the formation mechanism of hepatocellular carcinoma combined with PVTT in terms of local anatomy, hemodynamics, molecular biology and tumor microenvironment to provide effective reference for clinical treatment.