The Three Hundred project: Contrasting clusters galaxy density in hydrodynamical and dark matter only simulations

Cluster number count is a major cosmological probe for the next generation of cosmological large scale-structure surveys like the one expected from the Euclid satellite mission. Cosmological constraints will be mainly limited by the understanding of the selection function (SF), which characterize the probability of detecting a cluster of a given mass and redshift. The SF can be estimated by injecting realistic simulated clusters into the survey and re-applying the detection procedure. For this purpose we intend to use The Three Hundreds project, a 324 cluster sample simulated with full-physics hydrodynamical re-simulations. In this paper we concentrate on the study of the distribution of member galaxies in the cluster sample. First, we study possible resolution effects by comparing low and high resolution simulations. Finally, accounting for the latter we derive the density profiles of the member galaxies and discuss their evolution with cluster mass and redshift.

Oral N-acetylcysteine decreases IFN-γ production and ameliorates ischemia-reperfusion injury in steatotic livers

Type 1 Natural Killer T-cells (NKT1 cells) play a critical role in mediating hepatic ischemia-reperfusion injury (IRI). Although hepatic steatosis is a major risk factor for preservation type injury, how NKT cells impact this is understudied. Given NKT1 cell activation by phospholipid ligands recognized presented by CD1d, we hypothesized that NKT1 cells are key modulators of hepatic IRI because of the increased frequency of activating ligands in the setting of hepatic steatosis. We first demonstrate that IRI is exacerbated by a high-fat diet (HFD) in experimental murine models of warm partial ischemia. This is evident in the evaluation of ALT levels and Phasor-Fluorescence Lifetime (Phasor-FLIM) Imaging for glycolytic stress. Polychromatic flow cytometry identified pronounced increases in CD45+CD3+NK1.1+NKT1 cells in HFD fed mice when compared to mice fed a normal diet (ND). This observation is further extended to IRI, measuring ex vivo cytokine expression in the HFD and ND. Much higher interferon-gamma (IFN-γ) expression is noted in the HFD mice after IRI. We further tested our hypothesis by performing a lipidomic analysis of hepatic tissue and compared this to Phasor-FLIM imaging using "long lifetime species", a byproduct of lipid oxidation. There are higher levels of triacylglycerols and phospholipids in HFD mice. Since N-acetylcysteine (NAC) is able to limit hepatic steatosis, we tested how oral NAC supplementation in HFD mice impacted IRI. Interestingly, oral NAC supplementation in HFD mice results in improved hepatic enhancement using contrast-enhanced magnetic resonance imaging (MRI) compared to HFD control mice and normalization of glycolysis demonstrated by Phasor-FLIM imaging. This correlated with improved biochemical serum levels and a decrease in IFN-γ expression at a tissue level and from CD45+CD3+CD1d+ cells. Lipidomic evaluation of tissue in the HFD+NAC mice demonstrated a drastic decrease in triacylglycerol, suggesting downregulation of the PPAR-γ pathway.

[Identification of serum peptide biomarker for ovarian cancer diagnosis by Clin-TOF-II-MS combined with magnetic beads technology]

Objective: To explore the serum cyclic polypeptide biomarkers for ovarian cancer diagnosis. Methods: A total of 54 patients with epithelial ovarian cancer confirmed by pathology in Cancer Hospital, Chinese Academy of Medical Sciences from March 2018 to September 2018 were selected as the study subjects, and 40 healthy women with normal examination results in the cancer screening center were selected as the control. All of the samples were randomly divided into training set and validation set at the ratio of 1∶1 with a random number. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) combined with magnetic bead technology was used for detecting peptide profiling in serum samples to screen significantly differently expressed peptides between ovarian cancer group and control group of the training set (score>5). Receiver operating characteristic (ROC) curve analysis was used to screen differential peptide peaks with area under curve (AUC) ≥0.8, sensitivity and specificity>90% in the training set and validation set. Liquid chromatography-mass spectrometry (LC-MS/MS) was further used to determine the composition of differentially expressed peptides. Results: By comparing the peptide profiles of the two groups, 102 differential peptide peaks were initially detected in the mass-to-charge ratio range of 1 000 to 10 000. ROC curve analysis showed that there were 42 differential peptide peaks with AUC ≥0.8 in both training set and validation set, 19 of which were highly expressed in ovarian cancer group, and 23 were lowly expressed. There were 15 different peptide peaks in highly expressed ovarian cancer group with sensitivity and specificity over 90%. The mass-to-charge ratios were 7 744.27, 5 913.41, 5 329.87, 4 634.21, 4 202.02, 3 879.26, 3 273.35, 3 253.79, 3 234.34, 2 950.33, 2 664.51, 2 018.38, 1 893.37, 1 498.69 and 1 287.55. There were 15 different peptide peaks in lowly expressed ovarian cancer group with sensitivity and specificity over 90%, the mass-to-charge ratios were 9 288.46, 7 759.77, 5 925.24, 4 652.77, 4 210.42, 3 887.02, 3 279.90, 3 240.82, 2 962.15, 2 932.70, 2 022.42, 1 897.16, 1 501.69, 1 337.38 and 1 290.13. No protein composition was identified in 15 different peptide peaks in lowly expressed ovarian cancer group. The two protein compositions identified in 15 different peptide peaks in highly expressed ovarian cancer group were recombinant serglycin (SRGN) and fibinogen alpha chain (FGA), the mass-to-charge ratios of which were 1 498.696 and 5 913.417, respectively. The sensitivity and specificity of the two proteins for ovarian cancer diagnosis were 100%, 100% and 90.9%, 100%, respectively. Conclusion: SRGN and FGA are highly expressed in the serum of ovarian cancer patients, which may be potential diagnostic markers for ovarian cancer.

[Association of GMF-β expression with Ki-67 and its significance in the prognostic evaluation of astrocytoma]

Objective: To clarify the correlation of the expression of glia maturation factor-β (GMF-β) with Ki-67 in astrocytoma, and to investigate the prognostic implications of combined detection of GMF-β and Ki-67. Methods: One hundred and forty human astrocytoma samples (WHO Ⅱ-Ⅳ grade) were collected at Southwest Hospital, Army Medical University (the Third Military Medical University), China from 2006 to 2009. Clinicopathological information and 3-year follow-up data were collected. Expression of GMF-β and Ki-67 was detected by single and double immunohistochemical staining, then the association of GMF-β expression with Ki-67 and its significance in prognostic evaluation of astrocytoma were statistically analyzed. Results: GMF-β expression in astrocytoma cells was correlated to both tumor grade and Ki-67 (both P<0.05); Kaplan-Meier survival analysis showed that GMF-β and Ki-67 expression were negatively correlated to the 3 year-survival rates, respectively (both P<0.01). Further analysis demonstrated that the two factors were co-influenced on survival, showing a trend of "GMF-β^low Ki-67^low>GMF-β^high Ki-67^low>GMF-β^low Ki-67^high>GMF-β^high Ki-67^high" in 3-year survival rate with significant intergroup differences (P<0.05, P<0.01). Conclusions: GMF-β expression is positively associated with Ki-67 in astrocytoma. Combined detection of GMF-β and Ki-67 can predict prognosis of patients with glioma.

Cell-free DNA from bile outperformed plasma as a potential alternative to tissue biopsy in biliary tract cancer

BACKGROUND

Biliary tract cancers (BTCs) are rare and highly heterogenous malignant neoplasms. Because obtaining BTC tissues is challenging, the purpose of this study was to explore the potential roles of bile as a liquid biopsy medium in patients with BTC.

PATIENTS AND METHODS

Sixty-nine consecutive patients with suspected BTC were prospectively enrolled in this study. Capture-based targeted sequencing was performed on tumor tissues, whole blood cells, plasma, and bile samples using a large panel consisting of 520 cancer-related genes.

RESULTS

Of the 28 patients enrolled in this cohort, tumor tissues were available in eight patients, and plasma and bile were available in 28 patients. Somatic mutations were detected in 100% (8/8), 71.4% (20/28), and 53.6% (15/28) of samples comprising tumor tissue DNA, bile cell-free DNA (cfDNA), and plasma cfDNA, respectively. Bile cfDNA showed a significantly higher maximum allele frequency than plasma cfDNA (P = 0.0032). There were 56.2% of somatic single-nucleotide variant (SNVs)/insertions and deletions (indels) shared between bile and plasma cfDNA. When considering the genetic profiles of tumor tissues as the gold standard, the by-variant sensitivity and positive predictive value for SNVs/indels in bile cfDNA positive for somatic mutations were both 95.5%. The overall concordance for SNVs/indels in bile was significantly higher than that in plasma (99.1% versus 78.3%, P < 0.0001). Moreover, the sensitivity of CA 19-9 combined with bile cfDNA achieved 96.4% in BTC diagnosis.

CONCLUSION

We demonstrated that bile cfDNA was superior to plasma cfDNA in the detection of tumor-related genomic alterations. Bile cfDNA as a minimally invasive liquid biopsy medium might be a supplemental approach to confirm BTC diagnosis.

[Predicting postoperative recurrence of stage Ⅰ-Ⅲ renal clear cell carcinoma based on preoperative CT radiomics feature nomogram]

OBJECTIVE

To explore the preoperative radiomics features (RFs) and construct a nomogram for predicting postoperative recurrence of stage Ⅰ-Ⅲ clear cell renal carcinoma (ccRCC).

METHODS

The clinicopathological data and preoperative enhanced CT images collected from 256 patients with ccRCC were used as the training dataset (175 patients) and test dataset (81 patients). The enhanced CT images of the tumor were segmented using ITK-SNAP software, and the RFs were extracted using the PyRadiomics computing platform. In the training dataset, the RFs were screened based on Lasso-CV algorithm, and the Rad_score was calculated. The Clinic factors were screened by univariate and multivariate logistic regression analysis of the clinical and pathological factors and CT characteristics. The Rad_score, Clinic、Rad_score + Clinic nomograms were constructed and verified using the test dataset. The performance, discrimination power and calibration of the nomograms were compared, and their clinical value was evaluated using decision curve analysis.

RESULTS

Six RFs were retained to calculate the Rad_score. The Clinic factors included Rad_score, KPS score, platelet, calcification and TNM clinical stage. In terms of discrimination, the Rad_score + Clinic nomogram showed better performance (AUC=0.84 for training set; AUC=0.85 for test set) than the Rad_score nomogram (AUC=0.78 for training set, P=0.029; AUC=0.77 for Test set, P=0.025) and Clinic nomogram (AUC=0.77 for training set, P=0.014; AUC=0.77 for test set, P=0.011). In terms of calibration, the P value for goodness of fit test of the Rad_score+Clinic nomogram was 0.065 for the training set and 0.628 for the test set. Decision curve analysis showed a greater clinical value of the Rad_score+Clinic nomogram with Rad_score than the Clinic nomogram without Rad_score.

CONCLUSION

The nomogram based on preoperative CT RFs has a high value for predicting postoperative recurrence of stage Ⅰ-Ⅲ ccRCC to facilitate individualized treatment of RCC.

[Risk factors of occurrence and treatment failure of peritoneal dialysis-associated polymicrobial peritonitis: a multicenter retrospective study]

OBJECTIVE

To determine the risk factors of occurrence and treatment failure of peritoneal dialysis associatedperitonitis (PDAP) due to polymicrobial infections.

METHODS

We retrospectively collected the clinical data of patients with PDAP from the peritoneal dialysis (PD) centers in 4 general hospitals in Jilin Province from 2013 to 2019. The patients were divided, according to the results of peritoneal dialysate culture, into polymicrobial PDAP group and control group for comparison of the clinical data, treatment outcomes, and long-term prognosis. The independent risk factors of the occurrence and treatment failure of polymicrobial PDAP were explored using multivariate regression analysis.

RESULTS

We recruited a total of 625 patients from the 4 PD centers, among whom 1085 episodes of PDAP were recorded. Polymicrobial PDAP accounted for 7.6% of the total PDAP episodes, and this proportion increased from 5.3% in 2013-2016 to 9.4% in 2017-2019 (P= 0.012). Compared with the control group, polymicrobial PDAP group had higher proportions of elderly patients and patients with refractory PDAP, with greater white blood cell counts in the first-day dialysate and longer course of antibiotic treatment (P < 0.05). The risk of catheter removal and treatment failure (catheter removal or PDAP-related death) in polymicrobial PDAP group was 2.972 times (OR=2.972, 95% CI: 1.634-5.407, P < 0.001) and 2.692 times (OR=2.692, 95% CI: 1.578-4.591, P < 0.001) that in the control group, respectively. The risk of withdrawal from PD (technical failure + all-cause death) was 1.5- fold higher in polymicrobial PDAP group than that in the control group (OR=1.500, 95% CI: 1.085-2.074, P=0.014). Elderly patients (>65 years) had a 1.937-fold higher risk of experiencing polymicrobial PDAP than younger patients (OR=1.937, 95% CI: 1.207-3.109, P= 0.006). Diabetes mellitus (OR=5.554, 95% CI: 1.021-30.201, P=0.047), mixed fungal infeciton (OR=343.687, 95% CI: 21.554- 5480.144, P < 0.001), and Pseudomonas aeruginosa infection (OR=11.518, 95% CI: 1.632 to 81.310, P=0.014) were associated with increased risks of treatment failure by 4.554, 342.687 and 10.518 times, respectively.

CONCLUSION

The proportion of polymicrobial PDAP in the total PDAP cases tends to increase in recent years. Polymicrobial infection is an independent risk factor of both treatment failure and poor prognosis in patients with PDAP. An old age is an independent risk factor for polymicrobial PDAP, while diabetes mellitus and infections with mixed fungi or Pseudomonas aeruginosa are independent risk factors for treatment failure.

Arguments against the Requirement of a Biological License Application for Human Pancreatic Islets: The Position Statement of the Islets for US Collaborative Presented during the FDA Advisory Committee Meeting

The Food and Drug Administration (FDA) has been regulating human islets for allotransplantation as a biologic drug in the US. Consequently, the requirement of a biological license application (BLA) approval before clinical use of islet transplantation as a standard of care procedure has stalled the development of the field for the last 20 years. Herein, we provide our commentary to the multiple FDA's position papers and guidance for industry arguing that BLA requirement has been inappropriately applied to allogeneic islets, which was delivered to the FDA Cellular, Tissue and Gene Therapies Advisory Committee on 15 April 2021. We provided evidence that BLA requirement and drug related regulations are inadequate in reassuring islet product quality and potency as well as patient safety and clinical outcomes. As leaders in the field of transplantation and endocrinology under the "Islets for US Collaborative" designation, we examined the current regulatory status of islet transplantation in the US and identified several anticipated negative consequences of the BLA approval. In our commentary we also offer an alternative pathway for islet transplantation under the regulatory framework for organ transplantation, which would address deficiencies of in current system.

Minimizing Post-Infusion Portal Vein Bleeding during Intrahepatic Islet Transplantation in Mice

Although the liver is currently accepted as the primary transplantation site for human islets in clinical settings, islets are transplanted under the kidney capsule in most rodent preclinical islet transplantation studies. This model is commonly used because murine intrahepatic islet transplantation is technically challenging, and a high percentage of mice could die from surgical complications, especially bleeding from the injection site post-transplantation. In this study, two procedures that can minimize the incidence of post-infusion portal vein bleeding are demonstrated. The first method applies an absorbable hemostatic gelatin sponge to the injection site, and the second method involves penetrating the islet injection needle through the fat tissue first and then into the portal vein by using the fat tissue as a physical barrier to stop bleeding. Both methods could effectively prevent bleeding-induced mouse death. The whole liver section showing islet distribution and evidence of islet thrombosis post-transplantation, a typical feature for intrahepatic islet transplantation, were presented. These improved protocols refine the intrahepatic islet transplantation procedures and may help laboratories set up the procedure to study islet survival and function in pre-clinical settings.

Alpha-1 antitrypsin suppresses macrophage activation and promotes islet graft survival after intrahepatic islet transplantation

Alpha-1 antitrypsin (AAT) has protective functions in animal islet transplantation models. While the therapeutic effect of AAT therapy is currently being tested in clinical trials, we investigated the mechanism of AAT protection in a clinically relevant marginal intrahepatic human islet transplantation model. In recipients receiving islets and AAT, 68.9% (20/29) reached normoglycemia, compared to 35.7% (10/28) in those receiving islets only, at 60 days posttransplant (PT). AAT-treated mice had lower serum levels of inflammatory cytokines immediately PT. Reduced M1 macrophages were observed in livers of AAT-treated recipients compared to controls as evidenced by flow cytometry and RNA-seq transcriptional profiling analysis. In vitro AAT suppressed IFN-γ-induced M1 macrophage activation/polarization via suppression of STAT1 phosphorylation and iNOS production. AAT inhibits macrophage activation induced by cytokines or dying islets, and consequently leads to islet cell survival. In a macrophage depletion mouse model, the presence of M1 macrophages in the liver contributed to graft death. AAT, through suppressing macrophage activation, protected transplanted islets from death and dysfunction in the human islet and NOD-SCID mouse model. The protective effect of AAT was confirmed in a major mismatch allogeneic islet transplantation model. Taken together, AAT suppresses liver macrophage activation that contributes to graft survival after transplantation.

[Treatment of lumbar degenerative diseases with recapping laminoplasty and nerve root canal's decompression preserving the continuity of supraspinous ligament]

Objective: To explore the clinical effect of lumbar discectomy and nerve root canal's enlargement preserving the continuity of supraspinous ligament in the treatment of lumbar degenerative disease. Methods: The data of patients with lumbar degenerative disease who underwent operation from 2016 to 2018 were analyzed retrospectively, and the patients were divided into two groups according to the different operation. The treatment group (17 cases) was treated with recapping laminoplasty, lumbar discectomy and nerve root canal's enlargement, and the control group (28 cases) was treated with total laminectomy, nerve root canal's enlargement, lumbar discectomy, interbody fusion and internal fixation (PLIF). All patients were followed up for 12 to 27 months (mean 17.8 months). Japanese Orthopaedic Association Scores(JOA) and visual analogue scale(VAS) of pain were used to evaluate the clinical effect before and after the operation, lumbar dynamical X-ray and Cobb angle were collecting for imaging evaluation, and the adjacent segment degeneration at the last follow-up was recorded. Results: There was no significant difference in preoperative JOA score, VAS score and Lumbar Cobb angle between the two groups (all P>0.05). The operation time in the treatment group was shorter than that in the control group, and the blood loss during operation in the treatment group was lower than that in the control group, the bed rest time of the treatment group after operation was shorter than that in the control group ((79±14) vs (118±17) min, (151±38) vs (324±70) ml and (3.4±0.7) vs (4.3±1.0) d,respectively; t=-8.508, -10.724, -3.244, all P<0.01). In addition, compared with the control group, the volume of postoperative drainage in the treatment group also decreased significantly (t=-5.637, P<0.01). There was no significant difference in JOA score between the two groups 1 year after the operation (P>0.05), but there was significant difference in VAS score between the two groups, the treatment group was better than the control group (P<0.05). Compared with the control group, the lumbar Cobb angle in the treatment group increased significantly one year after the operation (55.3°±3.2° vs 38.4°±6.2°, t=10.391, P<0.05). During the follow-up, no loosening or fracture of the implants was found in all patients. Conclusion: Treatment of lumbar degenerative diseases with recapping laminoplasty and nerve root canal's decompression preserving the continuity of supraspinous ligament by ultrasound osteotome has the same clinical effect as PLIF. It has the advantages of shortening operation time, less bleeding, better maintenance of lumbar lordosis after operation and reduction of adjacent segment degeneration.

[A novel trans-muscular approach for microsurgical bilateral decompression via unilateral approach for degenerative lumbar stenosis: a series study]

Objective: To compare clinical outcomes of microsurgical bilateral decompression via unilateral approach (MBDU) between trans longissimus and iliocostalis approach, a novel lateral paraspinal approach(LPA), and classic Wiltseapproach for single level degenerative lumbar stenosis. Methods: LPA approach was researched by imaging measurement and cadaver anatomy. Retrospective analysis of a total 124 cases(male/female 75/49, aged(55±14) years) received single-level MBDU due to degenerative lumbar stenosis from 2016 to 2018 in Beijing Tiantan Hospital. Patients were categorized into two groups according to spinal canal morphology. Group A: trefoil shape (n=48), received MBDU via LPA; Group B: round & oval shape (n=76), received MBDU via Wiltse approach. Clinical parameters, including visual analogue scale (VAS) of pain, OswestryDability Index (ODI), satisfaction rate were assessed before the operation and at the latest follow-up. The internal fixation and intervertebral fusion were evaluated by X-ray and CT.The data were compared with single sample t test between the two groups. Results: The feasibility of trans longissimus and iliocostalis approach was proved by imaging measurement and anatomic study. The tube's maximum tilt angle in LPA group was 65°, and it was 40°in Wiltse group. There was no significantly difference in the operating time, bleeding and drainage volume between the two groups((120±27) min vs (115±32) min, (104±31) ml vs (110±41) ml, (50±15) ml vs (47±18) ml, respectively, t=1.246,-1.917,1.730,all P>0.05). In both groups, VAS and ODI scores significantly improved at the latest follow-up when compared with those before the operation (all P<0.05), but those were all comparable between the two groups(all P>0.05). The excellent rate of subjective satisfaction for the clinical efficacy in group A and B was 89.6%(43/48) and 86.8%(66/76) respectively (χ(2)=0.208,P>0.05). Conclusions: LPA approachfor microsurgical bilateral decompression via unilateral approach (MBDU) in degenerative lumbar stenosis is safe and effective, it has advantages in direct vison of contralateral nerve root canal decompression for trefoil shaped spinal canal.

Single-site laparoscopic percutaneous extraperitoneal closure (SLPEC) of hernia sac high ligation using an ordinary taper needle: a novel technique for pediatric inguinal hernia

PURPOSE

Laparoscopic high ligation of the internal inguinal ring is an alternative procedure for treatment of pediatric inguinal hernia (PIH), with a major trend toward increasing use of extracorporeal knotting and decreasing use of working ports. We have utilized this laparoscopic technique to treat the entire spectrum of PIH (including incarcerated cases) for more than 17 years, and the technique continues to evolve and improve. We herein report our latest modification of this minimally invasive technique, namely single-site laparoscopic percutaneous extraperitoneal closure (SLPEC) of hernia sac high ligation using an ordinary taper needle, and evaluate its safety and efficacy.

METHODS

From July 2016 to July 2019, 790 children with indirect PIH were treated by laparoscopic surgery. All patients underwent high ligation surgery with a modified single-site laparoscopic technique mainly performed by extracorporeal suturing with an ordinary closed-eye taper needle (1/2 arc 11 × 34). The clinical data were retrospectively analyzed.

RESULTS

All surgeries were successful without serious complications. A contralateral patent processus vaginalis (CPPV) was found intraoperatively and subsequently repaired in 190 patients (25.4%). The mean operative time was 15 min (8-25 min) for 557 unilateral hernias and 21 min (14-36 min) for 233 bilateral hernias. The mean postoperative stay was 20 h. Minor complications occurred in five patients (0.63%) and were managed properly, with no major impact on the final outcomes. No recurrence was noted in the patients who were followed up for 6-42 months. No obvious scar was present postoperatively.

CONCLUSION

Modified SLPEC of hernia sac high ligation using an ordinary taper needle for repair of indirect PIH is a safe, reliable, and minimally invasive procedure with satisfactory outcome, with no special device being needed. It is easy to learn and perform and is worthy of popularization in the clinical setting.

Construction of a doxycycline inducible lentivirus that expresses stem cell-specific miR-302 cluster

INTRODUCTION

The polycistronic miR-302 cluster encodes five miRNA genes that have an important role in the regulation of embryonic stem cell function. Studies showed that the miR-302 cluster can reprogram both mouse and human fibroblasts to induced pluripotent stem cells (iPSCs) with high efficiency. The aim of this study was to generate an inducible lentivirus that expresses miR-302 cluster in order to further investigate somatic cell reprogramming by these miRNAs.

MATERIALS AND METHODS

The miR-302 cluster was amplified by polymerase chain reaction technique from human genomic DNA and was ligated into pTRIPz, an inducible lentiviral vector.

RESULTS

MRC5 fibroblasts and HEK293 (human embryonic kidney) cells were infected with pTRIPz-302 cluster lentivirus and the family of 302 miRNAs were strongly expressed in HEK293 cells but lowly expressed in MRC5 fibroblasts. When cultured in hESC conditions, MRC5 cells expressed only low levels of DNMT3B, Nanog, Oct4 and Lin28 and failed to show stem cell induction. The red fluorescent expression seen in the majority of MRC5 cells, indicated that the rate of infection by lentivirus was efficient.

DISCUSSION

The efficiency of reprogramming may be improved perhaps by either using a different cell type or a high expression vector with a different type of promoter.

[Clinical safety and efficiency of ultrasonic bone curette used in anterior cervical discectomy and fusion surgery]

Objective: To investigate the safety and efficiency of ultrasonic bone curette used in anterior cervical discectomy and fusion surgery. Methods: As a retrospective study, we collected and analyzed the clinical data of 47 patients receiving anterior cervical discectomy and fusion surgery in Luohe Central Hospital from January 2014 to January 2017, there were 26 males and 21 females with a mean age of (52±9) years. According to the different surgical tools used in the process of decompression by resecting osteophytes or bone like an inverted Chinese character "" located at the posterior margin of the vertebral body, the patients were divided into two groups: ultrasonic bone curette group (group A) and traditional tools group (group B). The operating time, volume of intraoperative blood losing, complications, Japanese Orthopedic Association (JOA) score before and after the operation and improvement rate were recorded in the two groups. The t test was used to compare the data between the two groups. Results: In group A, the operating time was (47±7) min, blood loss was (49±4) ml, 1 case experienced urinary tract infection and there was no cerebrospinal fluid leakage or spinal cord injury. In group B, the operating time was (54±12) min and the blood loss was (117±16) ml, cerebrospinal fluid leakage occurred in 2 patients and the incision healed one-stage by local compression, hoarseness happened in 1 case and it disappeared after 2 weeks, 2 patients had swallowing discomfort and recovered in one month, no spinal cord injury occurred in this group. The operating time and blood loss in group A were lower than those in group B (t=2.691, 20.704, both P<0.05). And the incidence of complications in group A were lower than that in group B (χ(2)=4.157, P=0.041). The JOA score of group A at 3 days after surgery was improved for 39.0% when compared with that before the surgery, and it was improved for 71.6% at one year after the surgery. The JOA score in group B at 3 days after surgery was elevated for 38.7% from that before the surgery, and it increased for 69.4% at one year after the surgery. There was no significant different in JOA score before the surgery, 3 days and one year after the surgery between the two groups (t=0.611, 1.076, 0.061, all P>0.05). Conclusion: In the process of decompression by resecting osteophytes or bone located at the posterior margin of the vertebral body in the anterior cervical discectomy and fusion surgery, ultrasonic bone curette is safe and effective, and it can effectively shorten the operating time, decrease the blood loss and cut down the incidence of complications.

Comparison of hand-sewn versus modified coupled arterial anastomoses in head and neck reconstruction: a single operator's experience

Microvascular coupler devices have gained wide acceptance as an alternative to the traditional hand-sewn technique in reconstructive surgery. However, no study has directly compared the efficacy of the coupler and hand-sewn techniques in arterial anastomosis during head and neck reconstruction surgery. A total of 123 patients who underwent surgery performed by a single surgeon between 2016 and 2018 were included in this retrospective study. The patients were divided into the coupler group and the hand-sewn group according to the technique of arterial anastomosis used. Patients in the coupler group underwent a special procedure including arterial bifurcation to enlarge the recipient artery diameter. Of the 123 free flap surgeries performed, 56 were done using a coupler and 67 with the standard suture technique. One flap in the coupler group failed due to simultaneous arterial and venous thromboses. One flap in the hand-sewn group was lost due to venous compromise. The overall flap survival rate was 98.4% (n=121). There was a significant decrease in anastomotic time when a coupler was used (P<0.001). The complication and flap loss rates were similar in the coupler and hand-sewn groups. The application of the coupler helped to decrease the anastomotic time and achieved satisfactory vessel patency.

Direct investigation of current transport in cells by conductive atomic force microscopy

Currents play critical roles in neurons. Direct observation of current flows in cells at nanometre dimensions and picoampere current resolution is still a daunting task. In this study, we investigated the current flows in hippocampal neurons, PC12 cells and astrocytes in response to voltages applied to the cell membranes using conductive atomic force microscopy (CAFM). The spines in the hippocampal neurons play crucial roles in nerve signal transfer. When the applied voltage was greater than 7.2 V, PC12 cells even show metallic nanowire-like characteristics. Both the cell body and glial filaments of astrocytes yielded CAFM test results that reflect different electrical conductance. To our best knowledge, the electrical characteristics and current transport through components of cells (especially neurons) in response to an applied external voltage have been revealed for the first time at nanometre dimensions and picoampere current levels. We believe that such studies will pave new ways to study and model the electrical characteristics and physiological behaviours in cells and other biological samples.

Oral vaccination with the porcine circovirus type 2 (PCV-2) capsid protein expressed by Lactococcus lactis induces a specific immune response against PCV-2 in mice

AIMS

Porcine circovirus type 2 (PCV2) can cause postweaning, multisystemic wasting syndrome in pigs, which leads to enormous losses in the swine industry worldwide. Here, a genetically engineered Lactococcus strain expressing the main protective antigen of PCV2, the Cap protein, was developed to act against PCV2 infection as an oral vaccine.

METHODS AND RESULTS

Expression of the Cap protein was confirmed via western blot, ELISA and fluorescence microscopy. Over 90% of the recombinant pAMJ399-Cap/MG1363 survived a simulated gastrointestinal transit. It also survived the murine intestinal tract for at least 11 days. Then, the safety and immunogenicity of pAMJ399-Cap/MG1363 in orally immunized mice was evaluated. The levels of the sIgA, IgG and cytokines (IL-4 and IFN-γ) obtained from the mice immunized with pAMJ399-Cap/MG1363 were significantly higher than those in the control groups.

CONCLUSIONS

pAMJ399-Cap/MG1363 can survive in the gastrointestinal transit and effectively induce mucosal, cellular and humoral immune response against PCV2 infection via oral administration.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates the potential of the genetically engineered Lactococcus lactis as a candidate for an oral vaccine against PCV2.

Long-term culture and characterization of patient-derived primary hepatocytes using conditional reprogramming

Cultivation of primary human hepatocytes (PHHs) often faces obstacles including failure of long-term in vitro culture, weak proliferation ability, rapid loss of liver-specific function and morphology, and tendency of fibrosis. Previous research focused on immortalization methods, such as telomerase and viral, to culture immortalized primary human hepatocytes, which may lose some of the normal properties. However, non-immortalized PHHs often fail to maintain long-term viability and functionality. These highlight the urgent need for developing new culture strategy for PHHs. In the present study, we isolated PHHs from fresh human liver tissues representing different liver diseases and age groups. We used conditional reprogramming, without permanent immortalization, for long-term in vitro primary human hepatocytes cultivation and characterization. For functional characterization, we assessed CYP3A4, 1A1 and 2C9 activities and measured the mRNA expression of albumin , s100a4 , krt8 , krt18 , cyp1a1 , cyp3a4 , cyp2b6 , cyp2c8 , cyp2c9 , and cyp2d6 . Additionally, we compared the DNA fingerprint of the cells against their original liver tissues using short tandem repeat (STR) analysis. We found that PHHs-derived from young patients can survive for more than three months, while the lifespan of primary human hepatocytes derived from adult patients ranges from two to three months, which is longer than most commercial primary hepatocytes. Importantly, the cells at early passages retain strong CYP3A4, 1A1 and 2C9 activities and the DNA fingerprints are identical with their original tissues. Through conditional programming, we achieved, for the first time, a high level of success rate in the long-term in vitro cultivation of primary human hepatocytes-derived patients representing diverse liver disease. Moreover, the conditional programming cell culture technology reported in this paper requires neither co-culture with additive cells, nor complex and expensive components, such as collagen sandwich or spheroid culture. We thus believe that the patient-derived PHHs cultivation using conditional programming may provide a viable and valuable cell model to study liver disease-related mechanisms.