[Progress in research and development of soft tissue three-dimensional bioprinting and its supporting equipment].

As a cutting-edge technology of tissue engineering, three-dimensional bioprinting can accurately fabricate biomimetic tissue, which has made great progress in the field of hard tissue printing such as bones and teeth. Meanwhile, the research on soft tissue bioprinting is also developing rapidly. This article mainly discussed the development progress in various bioprinting technologies and supporting equipment including printing software, printing hardware, supporting consumables, and bioreactors for soft tissue three-dimensional bioprinting, and made a prospect for the future research and development direction of soft tissue three-dimensional bioprinting.

[Efficacy of in-situ full-left/full-right split liver transplantation for adult recipients using the living donor liver transplantation technique:a single-center report of 25 cases].

Objective: To evaluate the efficacy of in-situ full size split liver transplantation(fSLT) for adult recipients using the living donor liver transplantation(LDLT) technique and to compare the characteristics of the left hemiliver graft (LHG) and the right hemiliver graft(RHG)transplantation. Methods: Deceased donor and recipient data of 25 consecutive cases of fSLT at Department of Hepatopancreatobiliary Surgery, Ningbo Medical Center Lihuili Hospital from March to December 2021 was retrieved and the patients divided into two groups:LHG group and RHG group. Among the 13 donors,11 were male and 2 were female,aged (M(IQR))38(19) years(range: 25 to 56 years),with height of 168(5) cm(range:160 to 175 cm) and weight of 65(9) kg(range: 50 to 75 kg). The median age of the 25 recipients was 52(14) years(range:35 to 71 years),17 were male and 8 were female,15 had primary liver cancer and 10 had benign end-stage liver disease,model for end-stage liver disease score was 10(9) points(range:7 to 23 points). Of the 25 recipients,10 recipients had previously undergone hepatobiliary surgery. The follow-up period was to January 2022. Demographic,clinicopathological,surgical outcomes and postoperative complications were evaluated and compared between the two groups. Continuous quantitative data were compared using Mann-Whitney U test. Classification data were expressed as frequencies,and were compared between groups using χ2 test or Fisher exact probability method. Results: Using LDLT technique,in-situ full-left/full-right liver splitting was performed and 13 viable pairs of hemiliver grafts were harvested with acquisition time of 230(53) minutes(range:125 to 352 minutes) and blood loss of 250(100) ml(range:150 to 1 000 ml). A total of 25 hemiliver grafts(13 LHG and 12 RHG) were allocated to patients listed for liver transplantation in our center by China Organ Transplant Response System. In the LHG group(13 cases),there were more females and more patients with benign end-stage liver disease than in the RHG group(12 cases)(P<0.05). The body weight and graft weight of recipients in the LHG group were lower than that in RHG group(both P<0.05). There were no significant differences in other baseline data between the two groups(all P>0.05). The graft to recipient weight ratio(GRWR) was 1.2(0.4)%(range:0.7% to 1.9%) for 25 recipients,1.1(0.5)%(range:0.7% to 1.6%)for the LHG group and 1.3(0.5)%(range:0.9% to 1.9%)for the RHG group. There was no significant difference between the two groups (P>0.05). Sharing patterns of hepatic vessels and the common bile duct are as follows:all the trunk of middle hepatic vein were allocated to the LHG group. The proportion of celiac trunk,main portal vein and common bile duct assigned to LHG and RHG was 10∶3 (P=0.009), 9∶4 (P>0.05) and 4∶9 (P=0.027),respectively. The vena cava of 12 donors in early stage retained in LHG and that of last one was shared between LHG and RHG (P<0.01). The median cold ischemia time of 25 hemiliver grafts was 240(90) minutes(range:138 to 420 minutes). For the total of 25 fSLT,the median anhepatic phase was 50(16) minutes(range:31 to 98 minutes) and the operation time was 474(138)minutes(range:294 to 680 minutes) with blood loss of 800(640) ml(range:200 to 5 000 ml). There were no significant differences in all of operation data between two groups. In the LHG group,3 patients with GRWR≤0.8% had postoperative small-for-size syndrome which improved after treatment. Postoperative Clavien-Dindo grade≥Ⅲ complications were observed in 6 cases(24.0%),4 cases(4/13) in the LHG group and 2 cases(2/12) in the RHG group,respectively. The difference was not statistically significant. Among them,5 cases improved after re-operation and intervention,1 case in LHG group died of secondary infection 2 weeks after operation,and the mortality was 4.0%. Analysis of serious postoperative complications and death has suggested that conventional caval interposition should not be used for LHG transplantation. Conclusion: Relying on accurate donor-recipient evaluation and the apply of LDLT technique,the morbidity and mortality of in-situ fSLT in adults is acceptable.

[Research advances on the application of natural and recombinant collagen in wound repair].

Collagen is a macromolecular protein constituting the extracellular matrix of animal connective tissue, which has been widely used and developed in fields of biomedicine, tissue engineering, food, and cosmetics. Due to its advantages such as abundant sources and good biocompatibility, low immunogenicity, and degradability, collagen can be used as a dressing or tissue engineering scaffold for wound repair. According to the source of materials, collagen can be divided into natural collagen and recombinant collagen. Natural collagen is mainly extracted directly from mammals and fish; recombinant collagen is obtained based on genetic engineering technology, and its sources include recombinant expression systems of microorganisms, animals, and plants. This paper summarizes the sources of collagen, and the roles, advantages, and disadvantages of different sources of collagen in wound repair, the particularity and superiority of collagen combined with three-dimensional printing technology in wound repair, the impact of market norms of China's collagen industry on the field of wound repair, and explains the precautions for the development of collagen-related products, aiming to provide new ideas for selecting a suitable source of collagen for wound repair.

[mTOR signaling pathway-mediated autophagy involved in inhibition of osteoblast differentiation induced by cadmium in human bone marrow mesenchymal stem cells].

Objective: To investigate the role of autophagy mediated by mTOR signaling pathway in the inhibition of osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) induced by cadmium. Methods: HBMSCs were divided into 0, 2.5 or 5.0 µmol/L groups according to the exposure dose of cadmium chloride (CdCl2), and each group was treated for 1 day, 4 days and (or) 7 days. The ALP activity and mRNA and protein expression levels of osteogenesis markers (ALP, RUNX2 and OSTERIX), autophagy-related proteins (LC3 and Beclin-1) and mTOR signaling pathway related proteins (mTOR, p-mTOR and p-p70S6K) expression, alkaline phosphatase staining and alizarin red staining were detected. MHY 1485 was selected as the signaling pathway activator. The control group, CdCl2 group (5.0 µmol/L), MHY 1485 group and CdCl2+MHY 1485 combined treatment group were set. After 7 days of treatment, the expression levels of autophagy related proteins and mTOR signaling pathway related proteins of hBMSCs in each group were detected. Results: There was no significant difference in ALP activity between 0, 2.5 and 5.0 µmol/L groups on day 1 and 4 (P>0.05); On day 7, compared with the 0 µmol/L group, the ALP activity, expression of osteogenic markers (ALP, RUNX2, OSTERIX) and mTOR signaling pathway related proteins (mTOR, p-mTOR, p-p70S6K) expression decreased in the 2.5 and 5.0 µmol/L group (P<0.05). Compared with the 0 µmol/L group, the staining of the 2.5 and 5.0 µmol/L groups became lighter, and the formation of ALP and mineralized nodules was reduced. Compared with the CdCl2 group, the autophagy related protein expression in the CdCl2+MHY 1485 combined treatment group decreased, and the mTOR signaling pathway related protein expression increased. The difference was statistically significant (P<0.05). Conclusion: The inhibition of osteogenic differentiation of hBMSCs by cadmium may be related to autophagy mediated by mTOR signaling pathway.

Arthroscopic versus open disc repositioning and suturing techniques for the treatment of temporomandibular joint anterior disc displacement: 3-year follow-up study.

The aim of this study was to evaluate the outcomes of temporomandibular joint (TMJ) arthroscopic and open disc repositioning procedures in the management of anterior disc displacement (ADD). All consecutive patients treated with arthroscopic (group I) or open (group II) disc repositioning between April 2014 and August 2018 were included prospectively. The patients were assessed clinically (1, 3, 6, 12, 24, and 36 months postoperative) and with magnetic resonance imaging (MRI). The statistical analysis was performed using IBM SPSS Statistics v.22.0; P < 0.05 was considered significant. A total of 177 patients (227 joints) were included: 104 patients (130 joints) in group I and 73 patients (97 joints) in group II. There were statistically significant improvements in pain score, clicking, quality of life, diet, and maximum inter-incisal opening when comparing pre- and postoperative clinical parameters within the two groups (P < 0.05 at all time-points for all clinical parameters); however, improvements occurred earlier in group I (at 1 month) than in group II (6 months). Postoperative MRI revealed an overall success rate of 98.1% in group I and 97.3% in group II. New bone formation was found in 70.2% in group I and 30.1% in group II. Arthroscopy may be a better choice for ADD patients, with the advantages of faster clinical improvement and recovery, minimal invasiveness, and better condylar remodelling.

Mitochondrial Damage due to Hypoxia and Its Forensic Significance.

ABSTRACT: Mitochondria are the special organelle in eukaryotic cells. Their main functions are to synthesize energy required for cell activity by oxidative phosphorylation. Most of the oxygen absorbed by the body is consumed in the mitochondria. The precise diagnosis of mechanical asphyxia is one of the difficulties in forensic pathology practice. Forensic pathologists have been trying to find a reliable and sensitive marker for the diagnosis of mechanical asphyxia. Mitochondria are very sensitive to hypoxic environments, and the markers of mitochondrion damage can be used as a basis for the diagnosis of mechanical asphyxia. The purpose of this paper is to review the research progress on mitochondrial damage in hypoxic environments and to explore the possibility of using markers of mitochondrion damage in forensic pathological practice.

[Advances in the research of cold atmosphere plasma in the treatment of chronic wounds].

Chronic wounds are characterized by complex pathogenesis, long course of disease, and occur mostly in middle-aged and elderly people. As the population ages, chronic wounds have gradually become significant burden on the affected patients and the healthcare system. In the past decade, cold atmosphere plasma (CAP) was found to have the effects of resisting infection and promoting wound healing. By reviewing recent researches on the treatment of chronic wounds and biological effects of CAP at home and abroad, this article summarizes the research progress of CAP in the treatment of chronic wounds, aiming at providing a reference for the treatment of chronic wounds.

WWOX regulates the Elf5/Snail1 pathway to affect epithelial-mesenchymal transition of ovarian carcinoma cells in vitro.

OBJECTIVE: Ovarian cancer is a highly invasive type of cancer. A previous study demonstrated that E-cadherin expression was upregulated in a human ovarian cancer cell line with a high expression of WW domain-containing oxidoreductase (WWOX), which is a tumor suppressor. Also, the migration and invasion ability of these cells was reduced. Snail family members are involved in the epithelial-to-mesenchymal transition (EMT) of ovarian cancer cells, and the expression of Snail family members is regulated by the transcription factor Elf5. The aim of the present research was to elucidate the role of WWOX in EMT of ovarian carcinoma cells through the Elf5/Snail pathway by gain and loss of function approaches in in vitro experiments. MATERIALS AND METHODS: First, a WWOX gene expressing plasmid was transfected into CD133+CD117+ HO8910 ovarian carcinoma cells, and an Elf5 shRNA plasmid was transfected into these cells to assess the changes in EMT-related factors, including Snail1, and the invasive ability of tumor cells ability. Second, the human ovarian carcinoma cell lines HO8910 and SKOV3 were divided into six groups to detect the same indicators. RESULTS: The results demonstrated that the high expression of WWOX resulted in an increased E-cadherin expression, decreased Snail1 activity, and decreased invasion ability in CD133+CD117+ HO8910 cells. Elf5 shRNA transfection did not affect the WWOX expression; however, it decreased the expression of E-cadherin and Elf5 activity, while increasing Snail1 activity and invasion ability in CD133+CD117+ HO8910 cells. It was also observed that WWOX overexpression in HO8910 and SKOV3 cells inhibited the expression of EMT-related proteins and inhibited cell migration and invasion. CONCLUSIONS: Taken together, the results of the present report suggest that WWOX can decrease Snail1 activity by enhancing the activity of Elf5, thus upregulating E-cadherin expression and eventually inhibiting EMT of ovarian carcinoma.

[Epidemiological and pathogenic features of a bacillary dysentery outbreak in a boarding school caused by Shigella sonneri].

Objective: To investigate the etiologic and epidemiologic features of an infectious diarrhea outbreak in a boarding school in Fuyang city, Anhui province. Methods: Traceability hypothesis of this study was tested according to the epidemiological characteristics of the cases. Feces, anal swabs, water samples and food residues related to the patients and chefs were collected for pathogen isolation and detection. Biochemical identification, virulence gene detection, drug susceptibility test, PFGE and multilocus sequence typing were performed. Results: The incidence rate (3.41%) of different dormitory buildings within the water supply area by shallow wells was higher than that (0.98%) of the deep wells, with statistical significance (χ(2)=17.215, P<0.001). Sixteen strains belonged to the Shigella Sonneri family were isolated from the patient's samples, and all carrying the ipaH gene. Seven strains belonged to sen and ial genes. Set1 gene that did not appear in all the 16 strains were highly resistant to ampicillin, tetracycline, compound xinnomine, cefazoline, cefotaxime, gentamicin, naphthidinic acid and streptomycin, including 9 strains to doxycycline. The pulse field pattern of the 16 strains of Shigella sonneri appeared the same, with the ST type as ST152. Conclusion: When combined data from the etiological and epidemiological investigation, it was confirmed that Shigella sonneri was the pathogen of this outbreak, and water from the shallow wells might be responsible for the source of infection.

[Association between supporting child and elder abuse in China].

Objective: To examine the association between child-supporting from their folks and elder abuse in China so as to provide evidence for prevention and control of elder abuse. Methods: Based on the third survey on the Status of Chinese women, organized by the All-China Women's Federation and the National Bureau of Statistics, 7 159 residents aged 65 and older were included and general information on supporting child and elder abuse were gathered. Chi-square test and logistic regression were used to investigate the association between supporting child from elderly and elder abuse. Results: The overall prevalence of elder abuse was 6.71%. Risks of elder people being abused by family numbers varied from different supporting child situations. After adjusting for potential confounding factors, ORs for the elderly appeared as follows: OR=1.99 (95%CI: 1.56-2.54) for those who only providing support to male children; OR=2.07 (95%CI: 1.51-3.79) for those only providing support to the female offspring and OR=2.32 (95% CI: 1.72-3.13) for those who did not support their children regardless of their sex identity. Elderly who provided support to their children on both sexes were exposed to lower risk of being abused than those who only supporting their male offspring. There was no significant difference appearing on the risk of elder abuse between those elderly who only supporting the male (OR=1.00) or the female offspring (OR=1.04, 95% CI: 0.63-1.71), among all the participants in our study. However, such associations were different in urban and rural areas. Conclusions: High prevalence of abuse was seen in China. The pattern of supporting child was associated with risk of elder abuse. Elderly who showed poor support to their children were under higher risk of being abused by their family members.

[Genetic analysis and gene deduction of powdery mildew resistance in T. durum-Ae. squarrosa amphidiploids].

Eleven seedlings with resistance and two amphidiploids with disease resistance at all developmental stage were screened by using No. 15 isolate of E. graminis f. sp. tritici to inoculate 99 T. durum-Ae. squarrosa amphidiploids. The two amphidiploids with disease resistance at all developmental stage, M53 and M81, and their Ae. squarrosa parents were resistant to No. 15 isolate of powdery mildew payhogen, but their T. durum parents were susceptible. Therefore, the powdery mildew resistance of M53 and M81 were derived from Ae. squarrosa. Amphidiploid M74, which had the same durum parent as M53 but different Ae. squrrosa parent, was susceptible to No. 15 isolate in adult stage. M29 and M35, which had the same durum parent as M81 but different Ae. squarrosa parent were susceptible in all stage. These results were also proved that the powdery mildew resistance genes were derived from Ae. sqarrosa. Genetic analysis showed that powdery mildew resistance gene in M53 or M81 was a single dominant gene. A series of lines with known powdery mildew resistance genes and two unknown lines were used to test response patterns with 14 differential isolates of E. graminis f. sp. tritici. The response patterns in M53 and M81 were different from Pm1 to Pm21 and indicated that M53 and M81 conferred a new powdery mildew resistance gene respectively.

Conformational coupling: the moving parts of an ion pump.

The Na,K-ATPase carries out the coupled functions of ATP hydrolysis and cation transport. These functions are performed by two distinct regions of the protein. ATP binding and hydrolysis is mediated by the large central cytoplasmic loop of about 430 amino-acids. Transmembrane cation transport is accomplished via coordination of the Na and K ions by side-chains of the amino-acids of several of the transmembrane segments. The way in which these two protein domains interact lies at the heart of the molecular mechanism of active transport, or ion pumping. We summarize evidence obtained from protein chemistry studies of the purified renal Na,K-ATPase and from bacterially expressed polypeptides which characterize these separate functions and point to various movements which may occur as the protein transits through its reaction cycle. We then describe recent work using heterologous expression of renal Na,K-ATPase in baculovirus-infected insect cells which provides a suitable system to characterize such protein motions and which can be employed to test specific models arising from recently acquired high resolution structural information on related ion pumps.

Expression of an active Na,K-ATPase with an alpha-subunit lacking all twenty-three native cysteine residues.

We have constructed a mutant Na,K-ATPase alpha1-subunit with all native cysteine residues replaced. Using the baculovirus system, this cysteine-less alpha1-subunit and wild-type beta1-subunit were expressed in High Five cells. After 3 days of infection, cells were fractionated, and endoplasmic reticulum, Golgi apparatus, and plasma membranes were isolated. The molecular activity of the cysteine-less mutant in the plasma membranes was close to the wild-type protein (8223 min(-)(1) versus 6655 min(-)(1)). Cation and ATP activation of Na,K-ATPase activities revealed that replacing all 23 cysteines resulted in only a 50% reduction of K(m) for Na(+), a 2-fold increase in K(m) for K(+), and no changes in K(m) for ATP. The distribution of alpha-subunits among the membranes showed a high percentage of cysteine-less protein in the endoplasmic reticulum and Golgi apparatus compared with the wild-type protein. Furthermore, the cellular stability of the alphabeta assembly appeared reduced in the cysteine-less mutant. Cells harvested after more than 3 days of infection showed extensive degradation of the cysteine-less alpha-subunit, which is not observed with the wild-type enzyme. Thus the Na,K-ATPase contains no cysteine residues that are critical for function, but the folding and/or assembly pathway of this enzyme is affected by total cysteine substitution.

Site-directed chemical labeling of extracellular loops in a membrane protein. The topology of the Na,K-ATPase alpha-subunit.

We have mapped the membrane topology of the renal Na,K-ATPase alpha-subunit by using a combination of introduced cysteine mutants and surface labeling with a membrane impermeable Cys-directed reagent, N-biotinylaminoethyl methanethiosulfonate. To begin our investigation, two cysteine residues (Cys(911) and Cys(964)) in the wild-type alpha-subunit were substituted to create a background mutant devoid of exposed cysteines (Lutsenko, S., Daoud, S., and Kaplan, J. H. (1997) J. Biol. Chem. 272, 5249-5255). Into this background construct were then introduced single cysteines in each of the five putative extracellular loops (P118C, T309C, L793C, L876C, and M973C) and the resulting alpha-subunit mutants were co-expressed with the beta-subunit in baculovirus-infected insect cells. All of our expressed Na,K-ATPase mutants were functionally active. Their ATPase, phosphorylation, and ouabain binding activities were measured, and the turnover of the phosphoenzyme intermediate was close to the wild-type enzyme, suggesting that they are folded properly in the infected cells. Incubation of the insect cells with the cysteine-selective reagent revealed essentially no labeling of the alpha-subunit of the background construct and labeling of all five mutants with single cysteine residues in putative extracellular loops. Two additional mutants, V969C and L976C, were created to further define the M9M10 loop. The lack of labeling for these two mutants showed that although Met(973) is apparently exposed, Val(969) and Leu(976) are not, demonstrating that this method may also be utilized to define membrane aqueous boundaries of membrane proteins. Our labeling studies are consistent with a specific 10-transmembrane segment model of the Na,K-ATPase alpha-subunit. This strategy utilized only functional Na,K-ATPase mutants to establish the membrane topology of the entire alpha-subunit, in contrast to most previously applied methods.