BACKGROUND:In the treatment of skin trauma with active repair,tissue engineering techniques are needed to generate new tissue to replace necrotic tissue.Skin scaffolds have a good application prospect in the field of wound repair.Skin scaffolds need to present three-dimensional porous structures with certain mechanical strength to meet the needs of cell proliferation and division.However,the mechanical strength of the currently used gelatin-based biomaterials is weak and cannot meet the requirements of the use of skin scaffolds. OBJECTIVE:To study the 3D printing process used in the preparation of tissue engineering skin scaffolds by gelatin/oxidized nanocellulose composites,and focus on the relationship between the porosity and mechanical strength of the scaffolds prepared under different process parameters. METHODS:Oxidized nanocellulose whiskers at 10%concentration were extracted from Humulus scandens and then compounded with 5%gelatin to obtain gelatin/oxidized nanocellulose composites.The elastic modulus of gelatin and gelatin/oxidized nanocellulose composite was determined.Skin scaffolds were prepared by 3D printing extrusion molding using gelatin/oxidized nanocellulose composite as the base material.Mechanical and rheological properties of the composite were tested to determine extrusion molding parameters(filling gap 1.5-2.5 mm,uniform distribution of 0.1 mm;air pressure of 160-200 kPa),and the skin scaffold with a three-dimensional porous structure was prepared.The compressive performance of the skin scaffold was tested and compared with the finite element analysis results.The relationship between the filling gap and the porosity and mechanical strength of the scaffold was demonstrated. RESULTS AND CONCLUSION:(1)The elastic modulus of 5%gelatin was increased by 8.84 times by adding 10%oxidized nanocellulose whisker.A gel filament with a diameter of 1 mm was obtained by extrusion at the air pressure of 160 kPa.When the filling gap increased from 1.5 mm to 2.5 mm,the theoretical porosity of the scaffold increased from 33%to 60%,but the compressive strength decreased from 230 000 Pa to 95 000 Pa.(2)These findings showed that the skin scaffold with theoretical porosity of 50%and elastic modulus of 160 000 Pa was prepared by using 2 mm filling gap.The scaffold had a clear three-dimensional porous structure.

Objective To observe changes of plain MR T1WI signal intensity of dentate nucleus in nasopharyngeal carcinoma patients after radiotherapy and multiple times of intravenous injection of gadolinium-based contrast agent(GBCA).Methods Fifty patients with pathologically confirmed nasopharyngeal carcinoma and received intensity-modulated radiotherapy were retrospectively enrolled as the nasopharyngeal carcinoma group,and 50 patients with other malignant tumors and without history of brain radiotherapy were retrospectively enrolled as the control group.All patients received yearly GBCA enhanced MR examinations for the nasopharynx or the head.T1WI signal intensities of the dentate nucleus and the pons on same plane were measured based on images in the year of confirmed diagnosis(recorded as the first year)and in the second to the fifth years.T1WI signal intensity ratio of year i(ranging from 1 to 5)was calculated with values of dentate nucleus divided by values of the pons(△SIi),while the percentage of relative changes of year j(ranging from 2 to 51 was calculated with △SIj compared to △SIi(Rchangej).The values of these two parameters were compared,and the correlation of △SI and GBCA injection year-time was evaluated within each group.Results No significant difference of gender,age nor △SI1 was found between groups(all P＞0.05).The second to the fifth year △SI and Rchange in nasopharyngeal carcinoma group were all higher than those in control group(all P＜0.05).Within both groups,△SI was positively correlated with GBCA injection year-time(both P＜0.05).Conclusion Patients with nasopharyngeal carcinoma who underwent radiotherapy and multiple times of intravenous injection of GBCA tended to be found with gradually worsening GBCA deposition in dentate nucleus,for which radiotherapy might be a risk factor.

Objective:To explore the clinical and imaging characteristics of patients with unruptured intracranial aneurysms accompanied by sentinel headache.Methods:Forty patients with unruptured intracranial aneurysms confirmed by DSA/CTA and accompanied by sentinel headache admitted to Department of Neurology, First Affiliated Hospital of Xiangnan University from January 2018 to August 2023 were selected as the study subjects; the clinical and imaging characteristics of these patients were summarized. Forty-four patients with unruptured intracranial aneurysms without sentinel headache and 40 patients with subarachnoid hemorrhage caused by ruptured intracranial aneurysms admitted to the hospital at the same period were selected as controls. The differences in aneurysm length (maximum diameter), morphology, tumor length (maximum diameter)/neck width (AR), and risk score for rupture of intracranial aneurysms (scores of population, hypertension, age, size of aneurysm, earlier aneurysm rupture, site of aneurysm [PHASES]) among the 3 groups were analyzed.Results:Among the 40 patients with unruptured intracranial aneurysms accompanied by sentinel headache, 20 (50%) presented with pain localized at the lateral frontal and orbital regions, 3 (7.5%) with pain at the posterior neck region, and 17 (42.5%) with irregular headache sites; 34 (85%) had new onset headache, and 6 (15%) had changes in headache nature besides chronic headache; 24 patients (60%) had posterior communicating artery aneurysm, 12 (30%) had internal carotid artery aneurysm, 1 (2.5%) had middle cerebral artery aneurysm, and 3 (7.5%) had vertebral artery dissection aneurysm; 36 (90%) had irregular aneurysm morphology. Compared with patients with unruptured intracranial aneurysms without sentinel headache, patients with unruptured intracranial aneurysms accompanied by sentinel headache and those with subarachnoid hemorrhage caused by ruptured intracranial aneurysms had larger aneurysm length (maximum diameter), higher proportion of irregular morphology, higher AR value, and higher PHASES scores, with significant differences ( P<0.05). Compared with patients with subarachnoid hemorrhage caused by ruptured intracranial aneurysms, patients with unruptured intracranial aneurysms accompanied by sentinel headache had larger aneurysm length (maximum diameter) and higher PHASES scores, with significant differences ( P<0.05). Conclusion:Sentinel headache is common in patients with unruptured posterior communicating artery aneurysms, and the relatively specific headache pattern is sudden periorbital pain or posterior neck pain; patients with unruptured intracranial aneurysms accompanied by sentinel headache have a higher rupture risk due to the larger size, more irregular shape, higher AR value of the aneurysm, therefore, same attention should be payed to these patients as those with ruptured aneurysms in clinical practice.

Objective: As a gate-keeper enzyme link, pyruvate dehydrogenase E1 subunit alpha (PDHA1) functions as a key regulator during glycolysis and the mitochondrial citric acid cycle, which has been reported in several tumors. Nevertheless, the effects of PDHA1 on biological behaviors and metabolism remain unclear in cervical cancer (CC) cells. The study aims to explore the PDHA1 effects on glucose metabolism in CC cells and its possible mechanism. Methods: We first determined the expression levels of PDHA1 and activating protein 2 alpha (AP2α) as a PDHA1 potential transcription factor. The effects of PDHA1 in vivo were evaluated through a subcutaneous xenograft mouse model. Cell Counting Kit-8 assay, 5-ethynyl-2′-deoxyuridine (EdU) labeling assay, Transwell invasion assay, wound healing assay, Terminal deoxynucleotidyl transferase dUTP nick end labeling assay and flow cytometry were performed in CC cells. Oxygen consumption rate (OCR) levels were determined to reflect aerobic glycolysis level in gastric cancer cells. Reactive oxygen species (ROS) level was measured with 2′, 7′-dichlorofluorescein diacetate kit. The relationship between PDHA1 and AP2α was examined by conducting chromatin immunoprecipitation assay and electrophoretic mobility shift assay. Results: In CC tissues and cell lines, PDHA1 was downregulated, while AP2α was upregulated. Overexpression of PDHA1 remarkedly inhibited the proliferation, invasion and migration of CC cells, and tumor growth in vivo, as well as promoted OCR, apoptosis and ROS production. Moreover, AP2α directly bound to PDHA1 within suppressor of cytokine signaling 3 promoter region to negatively regulate PDHA1 expression level. What is more, PDHA1 knockdown could effectively reversed the AP2α silencing-mediated suppressive effects on cell proliferation, invasion, migration, and the promotive effects of AP2α knockdown on OCR, apoptosis and ROS production. Conclusions Our findings demonstrate that AP2α negatively regulated PDHA1 via binding to PDHA1 gene promoter to promote malignant CC cell behaviors, which may provide a potential approach for CC therapeutics.

Perilla (Perilla frutescens L.) is an important edible-medicinal oil crop, with its seed containing 46%-58% oil. Of perilla seed oil, α-linolenic acid (C18:3) accounts for more than 60%. Lysophosphatidic acid acyltransferase (LPAT) is one of the key enzymes responsible for triacylglycerol assembly in plant seeds, controlling the metabolic flow from lysophosphatidic acid to phosphatidic acid. In this study, the LPAT2 gene from the developing seeds of perilla was cloned and designated as PfLPAT2. The expression profile of PfLPAT2 gene was examined in various tissues and different seed development stages of perilla (10, 20, 30, and 40 days after flowering, DAF) by quantitative real-time PCR (qRT-PCR). In order to detect the subcellular localization of PfLPAT2 protein, a fusion expression vector containing PfLPAT2 and GFP was constructed and transformed into Nicotiana benthamiana leaves by Agrobacterium-mediated infiltration. In order to explore the enzymatic activity and biological function of PfLPAT2 protein, an E. coli expression vector, a yeast expression vector and a constitutive plant overexpression vector were constructed and transformed into an E. coli mutant SM2-1, a wild-type Saccharomyces cerevisiae strain INVSc1, and a common tobacco (Nicotiana tabacum, variety: Sumsun NN, SNN), respectively. The results showed that the PfLPAT2 open reading frame (ORF) sequence was 1 155 bp in length, encoding 384 amino acid residues. Functional structure domain prediction showed that PfLPAT2 protein has a typical conserved domain of lysophosphatidic acid acyltransferase. qRT-PCR analysis indicated that PfLPAT2 gene was expressed in all tissues tested, with the peak level in seed of 20 DAF of perilla. Subcellular localization prediction showed that PfLPAT2 protein is localized in cytoplasm. Functional complementation assay of PfLPAT2 in E. coli LPAAT mutant (SM2-1) showed that PfLPAT2 could restore the lipid biosynthesis of SM2-1 cell membrane and possess LPAT enzyme activity. The total oil content in the PfLPAT2 transgenic yeast was significantly increased, and the content of each fatty acid component changed compared with that of the non-transgenic control strain. Particularly, oleic acid (C18:1) in the transgenic yeast significantly increased, indicating that PfLPAT2 has a higher substrate preference for C18:1. Importantly, total fatty acid content in the transgenic tobacco leaves increased by about 0.42 times compared to that of the controls, with the C18:1 content doubled. The increased total oil content and the altered fatty acid composition in transgenic tobacco lines demonstrated that the heterologous expression of PfLPAT2 could promote host oil biosynthesis and the accumulation of health-promoting fatty acids (C18:1 and C18:3). This study will provide a theoretical basis and genetic elements for in-depth analysis of the molecular regulation mechanism of perilla oil, especially the synthesis of unsaturated fatty acids, which is beneficial to the genetic improvement of oil quality of oil crops.
Acyltransferases ; Cloning, Molecular ; Escherichia coli/metabolism* ; Fatty Acids ; Perilla frutescens/metabolism* ; Plant Oils ; Plant Proteins/metabolism* ; Saccharomyces cerevisiae/metabolism* ; Seeds/chemistry* ; Tobacco/genetics*

ObjectiveTo investigate the mechanism of quercetin in regulating chondrocyte extracellular matrix metabolism and inflammatory response in knee osteoarthritis （KOA） from the perspective of autophagy. MethodChondrocytes were extracted and cultured， and the primary cells were identified by immunofluorescence staining with collagen Ⅱ. The chondrocytes induced by lipopolysaccharide （LPS） were divided into a control group （without any treatment）， a model group （10 mg·L^-1 LPS treatment for 48 h）， and low-， medium-， and high-dose quercetin group （10 mg·L^-1 LPS treatment for 48 h combined with 50， 100， and 150 mmol·L^-1 quercetin for 24 h）. The inhibitory effects of LPS （2.5， 5， 7.5， 10， 12.5 mg·L^-1） on the proliferation of chondrocytes for different periods （24， 48， 72 h） were detected by cell counting kit-8 （CCK-8）. The effects of quercetin （50， 100， 150， 200 mmol·L^-1） on the LPS-induced proliferation of chondrocytes for different periods （12， 24， and 48 h） were investigated. The expression of microtubule-associated protein 1 light chain 3Ⅱ （LC3Ⅱ） and ubiquitin-binding protein p62 was detected by Western blot. LPS-induced chondrocytes were treated with 3-methyladenine （3-MA）. The resultant cells were divided into a control group （without any treatment）， a model group （10 mg·L^-1 LPS）， a quercetin group （model group + 100 mmol·L^-1 quercetin）， a 3-MA group （model group + 100 μmol·L^-1 3-MA）， and a 3-MA + quercetin group （model group + 100 μmol·L^-1 3-MA + 100 mmol·L^-1 quercetin， specifically， LPS for 48 h， 3-MA for 2 h， and then quercetin for 24 h）. The content of interleukin （IL）-1β and tumor necrosis factor （TNF）-α was determined by enzyme-linked immunosorbent assay （ELISA）. The protein expression of matrix metalloproteinase 13 （MMP-13） and tissue inhibitor of metalloproteinase 1 （TIMP1） was detected by Western blot. ResultCollagen Ⅱ immunofluorescence staining showed that the extracted cells were consistent with the characteristics of chondrocytes. As revealed by CCK-8， the optimum concentration of LPS was 10 mg·L^-1 with an action time of 48 h， and the optimum concentration of quercetin was 100 mmol·L^-1 with an action time of 24 h. Western blot results showed that compared with the control group， the model group showed decreased expression of LC3Ⅱ （P<0.01） and increased expression of p62 （P<0.01）. The expression of LC3Ⅱ in the quercetin groups was higher than that in the control group （P<0.01）， especially in the medium-dose quercetin group. The p62 expression in the quercetin groups was lower than that in the control group （P<0.01）， especially in the medium-dose quercetin group. Compared with the control group， the model group showed increased expression of MMP-13 （P<0.05） and decreased expression of TIMP1 （P<0.01）. Compared with the model group， the quercetin groups and the 3-MA + quercetin group showed decreased expression of MMP-13 （P<0.05， P<0.01）， especially the quercetin groups， and increased expression of TIMP1 （P<0.01）， especially the quercetin groups. Morphological changes in chondrocytes under the inverted microscope showed that quercetin could restore the morphology of damaged chondrocytes. CCK-8 showed that compared with the control group， the model group showed inhibited chondrocyte proliferation （P<0.01）， and compared with the model group， the quercetin groups and the 3-MA + quercetin group showed promoted chondrocyte proliferation （P<0.01）， especially the quercetin groups. ELISA results showed that IL-1β and TNF-α levels in the model group were higher than those in the control group （P<0.01）， and the levels of IL-1β and TNF-α in the quercetin groups and the 3-MA + quercetin group were lower than those in the model group （P<0.05， P<0.01）， and the decrease in the quercetin groups was the most significant. ConclusionQuercetin can promote LPS-induced chondrocyte proliferation， regulate chondrocyte extracellular matrix synthesis and metabolic balance， inhibit the inflammatory response， and restore chondrocyte function. The mechanism may be related to the activation of autophagy by quercetin.

Objective:To investigate the clinical and imaging features of spontaneous convexal subarachnoid hemorrhage (cSAH) with acute cerebral infarction.Methods:Nine patients with cSAH complicated with acute cerebral infarction, admitted to our hospital from January 2018 to October 2021, were selected. The clinical data and efficacy of these patients were retrospectively analyzed.Results:The time from cSAH to the onset of acute cerebral infarction was 5-144 h, with median time of 2 d. The most common bleeding site of cSAH was the parietal lobe ( n=6); cSAH in the ipsilateral side of acute cerebral infarction was noted in 4 patients. Six patients had middle cerebral artery stenosis or occlusion, and 2 patients had anterior cerebral artery stenosis or occlusion. Hypertension ( n=7) was the most common primary disease; 7 patients were treated with antiplatelet drugs, anticoagulants and/or stents. The follow-up at 3 months after cSAH showed that 6 patients had good prognosis and one had poor prognosis. Conclusions:The cSAH often occurs 2 d after acute cerebral infarction; intracranial artery stenosis or occlusion may be the main cause of the disease. In patients complicated with cSAH, active antiplatelet, anticoagulation and/or stent therapy do not increase the risk of bleeding, and the prognosis is good.

In the original publication, the label of Fig. 2C should be read as "GFAP/lectin/DAPI" not "DMP1/GFAP/lectin/DAPI".

Studies have found that a variety of tumors continue to activate PD-1(programmed cell death protein 1, PD-1)/PD-L1(programmed cell death-ligand 1)signaling pathway by up-regulating PD-L1 expression in tumor cells and microenvironment. The dysfunction of T cells leads to the occurrence of tumor immune escape. Several PD-1/PD-L1 monoclonal antibodies have been marketed to achieve significant clinical efficacy. However, because of the high production cost, the harsh conditions for storage and transportation, and the potential immunogenicity of monoclonal antibody, the seeking for PD-1/PD-L1 small molecule inhibitors has become a hot spot in the development of new drugs. In this paper, the biological mechanisms of PD-1/PD-L1 was introduced in detail. Based on the structural classification, the research progress of PD-1/PD-L1 small molecule inhibitors was reviewed, with a prospect of the development of small molecule inhibitors.

Objective? To explore the effects of structured hypothermia intervention program in elderly intestinal cancer patients with frailty. Methods? From November 2017 to July 2018, we selected 96 patients with surgery for intestinal cancer scored more than two points in Fried frailty assessment for the aged before surgery at the First Affiliated Hospital of Hu'nan Normal University & People's Hospital of Hu'nan Province by cluster sampling. All of the patients were divided into experimental group (n=48) and control group (n=48) with the method of random number table. Experimental group carried out the structured management model, formulated and implemented the structured hypothermia intervention program, while control group provided warm nursing based on nursing routine. We compared the respiration, blood pressure, heart rate and blood oxygen saturation before, during and after surgery as well as temperature, incidence of hypothermia and related indicators (extubation time, retention time in resuscitation room, urine volume and intraoperative blood loss) at each time points during surgery. Results were analyzed with the repeated measure variance analysis, t test and χ2 test. Results? There were interactions between time and groups in temperature, blood pressure, heart rate, respiration and blood oxygen saturation (P＜ 0.05). The fluctuation with time of the above vital signs in the experimental group was lower than that of control group. In experimental group, the incidence of hypothermia was lower than that in control group; the extubation time and retention time in resuscitation room were shorter than those in control group; the intraoperative blood loss was less than that in control group and the urine volume was more than that in control group;the differences were all statistically significant (P＜ 0.01). Conclusions? The application of structured hypothermia intervention program in elderly intestinal cancer patients with frailty can effectively maintain the stable intraoperative vital signs, shorten the time anesthesia resuscitation, reduce the incidences of hypothermia and related complications, standardize preventive measures for intraoperative hypothermia and guarantee patient intraoperative safety among elderly intestinal cancer patients with frailty.