Objective To investigate the involvement of Bcl-2 and Bax mRNA expressions in mitochondrial toxin 3-nitropropionic acid(3-NPA)induced ischemic tolerance to focal cerebral ischemia in rats.Methods Rats were administrated 3-NPA intraperitoneally at dose of 20 mg/kg 3 days prior to a 2 h middle cerebral artery occlusion followed by 1 h,6 h,12 h,24 h and 48 h of reperfusion.The Bcl-2 and Bax mRNA expressions were measured by reverse transcriptase polymerase chain reaction and compared to the sham operation group and ischemic reperfusion group.Results Compared to the sham operation group,the ischemic reperfusion and 3-NPA pretreated groups exhibited an increase in Bcl-2 and Bax mRNA after reperfusion every time point of focal cerebral ischemia(all(P

AIM: To investigate the relationship between astroglial activation state and ischemic tolerance induced by low dose of 3 nitropropionic acid (3 NPA) in gerbil hippocampus. METHODS: Transient forebrain ischemic model was induced by bilateral common carotid arteries occlution. HE staining and immunohistochemistry were used to identify neuronal and astrocyte response. RESULTS: Preconditioning with 3 NPA produced protective effects of CA 1neurons. The number of glial fibrillary acidic protein positive astrocyte in hippocampal CA 1 region increased slightly in control group, but increased significantly in preconditioning of the brain with 3 nitropropionic acid. CONCLUSION: The state of astroglial activation is related to neuronal survival in ischemic tolerance induced by low dose of 3 nitropropionic acid.

To examine the changes in erythropoietin (Epo) protein and its mRNA expression in rat brain subjected to focal ischemia and possible mechanism of the preconditioning of mitochondrial toxin 3-nitropropionic acid (3-NPA), rats were administrated either vehicle or 3-NPA at a dose of 20 mg/kg, intraperitoneally (ip), 3 days prior to a 2-h middle cerebral artery occlusion followed by 24-h reperfusion. Infarct volumes were measured by using 2, 3, 5 triphenylte trazolinm chloride (TTC) staining, and Epo protein and its mRNA levels were assessed by immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR), respectively. Our results showed that after reperfusion, Epo was found to be expressed extensively in the rat brain. It was most apparent in the basal nuclei and hippocampus, and was, to some extent, present in cortex. Preconditioning with 3-NPA caused a reduction in infarct volume. The expression of both Epo protein and mRNA increased significantly in the different brain areas in the 3-NPA pretreated group as compared with the non-pretreated ischemia model group. These results suggested that preconditioning with low dose 3-NPA could induce ischemic tolerance and neuro-protective effects by increasing the Epo expression in the ischemic and ischemia-related areas.

To examine the changes in erythropoietin (Epo) protein and its mRNA expression in rat brain subjected to focal ischemia and possible mechanism of the preconditioning of mitochondrial toxin 3-nitropropionic acid (3-NPA), rats were administrated either vehicle or 3-NPA at a dose of 20 mg/kg,intraperitoneally (ip), 3 days prior to a 2-h middle cerebral artery occlusion followed by 24- h reperfusion. Infarct volumes were measured by using 2, 3, 5 triphenylte trazolinm chloride (TTC)staining, and Epo protein and its mRNA levels were assessed by immunohistochemistry and reverse transcriptase polymerase chain reaction (RT-PCR), respectively. Our results showed that after reperfusion, Epo was found to be expressed extensively in the rat brain. It was most apparent in the basal nuclei and hippocampus, and was, to some extent, present in cortex. Preconditioning with 3-NPA caused a reduction in infarct volume. The expression of both Epo protein and mRNA increased significantly in the different brain areas in the 3-NPA pretreated group as compared with the non-pretreated ischemia model group. These results suggested that preconditioning with low dose 3-NPA could induce ischemic tolerance and neuro-protective effects by increasing the Epo expression in the ischemic and ischemia-related areas.

The involvement of apoptosis in mitochondrial toxin 3-nitropropionic acid (3-NPA)-induced ischemic tolerance to transient focal cerebral ischemia in rats and the mechanism was investigated. 3-NPA at a dose of 20 mg/kg or vehicle control was intraperitoneally into the rats. Three days later, rats were exposed to 2 h of middle cerebral artery occlusion followed by 24 h of reperfusion. Infarct volumes were assessed by 2,3,5-triphenyltetrazolinm chloride (TTC) staining 24 h after reperfusion. Neural cell apoptosis in cerebral ischemic penumbra was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL) and flow cytometry methods (FCM). The results showed that as compared to the vehicle-treated group, pretreatment with 3-NPA could reduce the infarct volume by 23.3% and decrease the number of TUNEL-positive neural cells and apoptotic percentage by 47% (P<0.05) and 44.9% (P<0.01), respectively. It was concluded that the development of 3-NPA-induced ischemic tolerance in brain might be related to the decreases in neural cell apoptosis.
Animals ; Apoptosis ; drug effects ; Cerebral Cortex ; blood supply ; Cerebrovascular Circulation ; DNA Damage ; Infarction, Middle Cerebral Artery ; pathology ; Ischemic Attack, Transient ; chemically induced ; pathology ; Ischemic Preconditioning ; Male ; Middle Cerebral Artery ; pathology ; Nitro Compounds ; Propionates ; Rats ; Reperfusion Injury ; pathology

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.

Esophageal cancer is one of the top ten of the world's most common cancer. Although the incidence of esophageal squamous cell carcinoma (ESCC) in some high-risk areas in East Asia has being decreasing, it is still the most common histologic subtypes. A great many of patients with ESCC not only are diagnosed in an advanced stage but also have a high mortality rate. With the application of tumor immunotherapy in ESCC treatment in recent years, the prognosis of ESCC patients has been improved to a certain extent. This article intends to review the research progress of immunotherapy in esophageal squamous cell carcinoma.

Objective To analyze the current development of researches on biomarkers for predicting the efficacy of immunotherapy in non-small cell lung cancer and to provide reference for subsequent studies. Methods Studies on biomarkers for predicting the efficacy of immunotherapy for non-small cell lung cancer indexed in the Web of Science Core Collection from 2017 to 2021 were searched by computer. The annual distribution, journals, authors, countries, institutions, and keywords of studies were visualized and analyzed by CiteSpace. Results A total of 426 studies were collected, including 298 articles and 128 reviews. The average number of published studies was about 85, and increased year by year. PD-L1 expression, tumor mutational burden, tumor microenvironment and liquid biopsy were hot keywords in this field. Conclusion In the future, combination of biomarkers in the liquid biopsy and tumor microenvironment with radiomics analysis will be the research hotspot and frontier in this field for more accurate assessment with tumor-related signatures such as lymphocytic immune status and characteristics of tumor lesions in non-small cell lung cancer patients.

Objective To analyze the current research application status and hotspots of nanoparticles in the treatment of non-small cell lung cancer (NSCLC) and predict the future development trend. Methods The Web of Science database was searched for literatures on nanoparticles use in the treatment of NSCLC from inception to November 2022. CiteSpace, VOSviewer and literature measurement analysis online platform (https://bibliometric.com/) were used for the visual analysis of the number of documents, source journals, authors, organizations, countries and keywords. Results A total of 742 English literatures were included. The results showed that the number of published literatures increased year by year from 2011 and reached the peak in 2020. Researches on nanoparticles and NSCLC treatment were mainly concentrated in China, the United States, India and Japan. China is a major research country in this field, but it lacked cooperation with other countries and related institutions. Among numerous research institutions, the Chinese Academy of Sciences was the authoritative and backbone force in this research field, with the number of published literatures ranking first and the research achievements outstanding. The keyword analysis found that "poly lactic-co-glycolic acid nanoparticles (PLGA NPs)" and "photothermal therapy" had become the latest breakout words since 2018. Moreover, the occurrence frequency of related keywords such as "drug delivery" increased significantly, indicating that the application of PLGA NPs in photothermal therapy might be the current research hotspot and future development trend of NSCLC treatment. Conclusion Currently, the domestic research on the treatment of nanoparticles and NSCLC is in a leading position in the world. The organic combination of nanoparticles with different materials and other NSCLC therapies is expected to improve the prognosis of NSCLC patients. In the future, attempts to develop nanoparticles with different sources and structures and combined with photothermal therapy for the treatment of NSCLC may become a research hotspot of nanoparticles in the treatment of NSCLC.