Collagen is a major structural protein in the matrix of animal cells and the most widely distributed and abundant functional protein in mammals. Collagen’s good biocompatibility, biodegradability and biological activity make it a very valuable biomaterial. According to the source of collagen, it can be broadly categorized into two types: one is animal collagen; the other is recombinant collagen. Animal collagen is mainly extracted and purified from animal connective tissues by chemical methods, such as acid, alkali and enzyme methods, etc. Recombinant collagen refers to collagen produced by gene splicing technology, where the amino acid sequence is first designed and improved according to one’s own needs, and the gene sequence of improved recombinant collagen is highly consistent with that of human beings, and then the designed gene sequence is cloned into the appropriate vector, and then transferred to the appropriate expression vector. The designed gene sequence is cloned into a suitable vector, and then transferred to a suitable expression system for full expression, and finally the target protein is obtained by extraction and purification technology. Recombinant collagen has excellent histocompatibility and water solubility, can be directly absorbed by the human body and participate in the construction of collagen, remodeling of the extracellular matrix, cell growth, wound healing and site filling, etc., which has demonstrated significant effects, and has become the focus of the development of modern biomedical materials. This paper firstly elaborates the structure, type, and tissue distribution of human collagen, as well as the associated genetic diseases of different types of collagen, then introduces the specific process of producing animal source collagen and recombinant collagen, explains the advantages of recombinant collagen production method, and then introduces the various systems of expressing recombinant collagen, as well as their advantages and disadvantages, and finally briefly introduces the application of animal collagen, focusing on the use of animal collagen in the development of biopharmaceutical materials. In terms of application, it focuses on the use of animal disease models exploring the application effects of recombinant collagen in wound hemostasis, wound repair, corneal therapy, female pelvic floor dysfunction (FPFD), vaginal atrophy (VA) and vaginal dryness, thin endometritis (TE), chronic endometritis (CE), bone tissue regeneration in vivo, cardiovascular diseases, breast cancer (BC) and anti-aging. The mechanism of action of recombinant collagen in the treatment of FPFD and CE was introduced, and the clinical application and curative effect of recombinant collagen in skin burn, skin wound, dermatitis, acne and menopausal urogenital syndrome (GSM) were summarized. From the exploratory studies and clinical applications, it is evident that recombinant collagen has demonstrated surprising effects in the treatment of all types of diseases, such as reducing inflammation, promoting cell proliferation, migration and adhesion, increasing collagen deposition, and remodeling the extracellular matrix. At the end of the review, the challenges faced by recombinant collagen are summarized: to develop new recombinant collagen types and dosage forms, to explore the mechanism of action of recombinant collagen, and to provide an outlook for the future development and application of recombinant collagen.

Hearing loss is one of the common radiotherapy-induced complications of head and neck tumors, including nasopharyngeal carcinoma. These side reactions can be classified into acute or delayed types, which affect all structures of the auditory organs, resulting in conductive, sensorineural or mixed hearing loss. Up to 40% of patients develop acute middle ear side effects during radical radiotherapy, while approximately 1/3 develop late sensorineural hearing loss. The total radiation dose and tumor site appear to be the most important factors associated with the risk of hearing loss. The mechanisms of conductive and sensorineural hearing impairment are different. New radiotherapy techniques (three-dimensional conformal radiotherapy, intensity modulated radiotherapy, proton therapy) enable better dose distribution, lower dose to non-target organs, and gradually increase the feasibility of protecting normal tissues. The present article illustrates recent progress in radiotherapy-induced hearing loss, specially focusing on the occurrence, the mechanisms and related factors of ear toxicity, detection and diagnosis, and treatment.

Dysphagia is the main complication of chemoradiotherapy for head and neck cancer. Recently, the advancement of multidisciplinary treatment has achieved a higher tumor control rate, but also a higher incidence of late radiation-induced dysphagia in head and neck cancer. Radiation-induced dysphagia leads to prolonged unnatural feeding, nutritional deficiency, weight loss, and also has a major risk for silent aspiration and aspiration pneumonia, which significantly reduces the quality of life of patients. Besides, late radiation-induced dysphagia is the main reason for limiting the intensity of treatment. Therefore, it is of great significance to deeply understand the pathogenesis of radiation-induced dysphagia and actively explore effective prevention and treatment measures to improve the survival rate and quality of life in head and neck cancer. This paper summarizes the pathogenesis, occurrence, risk factors of radiation-induced dysphagia in head and neck cancer, as well as the progress in the measurement and reporting methods, prevention and treatment strategies.

Cardiotoxicity is traditionally regarded as the late toxic side effect of radiotherapy. Classical radiobiology suggests that non-proliferative and highly-differentiated tissues, such as the heart, should exhibit robust resistance to ionizing radiation. However, in-depth analyses of radiation-induced heart disease (RIHD) have discovered that radiation can induce a range of physiological changes in the heart. These changes, which include endothelial dysfunction, inflammation, thrombosis, and cardiac fibrosis, may be significantly accelerated as radiation doses increase. At present, multidisciplinary team treatment modalities have substantially enhanced curative effects for cancer patients. However, the resulting prolongation of survival time exposes a larger patient population to the risks of treatment-related cardiotoxicity, establishing RIHD as a pressing research concern. This article offers a systematic review of recent insights into the incidence of RIHD, the relationship between radiotherapy and RIHD, methods for its detection and diagnosis, as well as its pathogenesis and potential treatment strategies.

Surgery, radiotherapy and chemotherapy are currently the principal modalities for oncological treatment. Approximately 70% of patients with malignant tumors require radiotherapy. However, the damage induced by radiation on normal human tissues remains an unavoidable issue in clinical practice. When radiotherapy is applied to abdominal and pelvic tumors such as liver cancer, colorectal cancer, cervical cancer, and prostate cancer, the anatomical proximity of these organs to the small intestine inevitably leads to some degree of intestinal damage. This type of injury, induced by radiotherapy, is referred as radiation-induced small intestine injury. Clinically, a high incidence of radiation-induced small intestine injury is observed among patients receiving pelvic and abdominal radiotherapy, which not only impacts the quality of life of cancer patients, but also limits the effectiveness of the treatment. This article reviews the research progress in radiation-induced small intestine injury.

Radiotherapy is one of the main treatment methods for malignant tumors, which can cause the radiation damage to normal tissues. Radiation-induced skin injury (RISI) is one of the main adverse reactions caused by radiotherapy. The main clinical manifestations of RISI are dermatitis, ulcer, erosion and necrosis, which seriously affect the quality of life and treatment effect of tumor radiotherapy patients, and even affect the overall survival of patients. The pathological mechanism of RISI is still unclear. Some studies have shown that inflammation and oxidative stress are the main causes of RISI. RISI can be divided into acute and chronic RISI according to the different onset time, and different treatment strategies can be formulated according to the severity of the injury. In this article, clinical manifestations, classification, pathogenesis, prevention and treatment of RISI are comprehensively summarized.

Objective:To analyze the distribution characteristics of plasma renin concentration (PRC) in patients with aldosterone-producing adenoma (APA) and its impact on diagnosis.Methods:In this retrospective case series, clinical data from 200 patients with APA (80 men and 120 women; mean age 45.6 years) in the First Affiliated Hospital of Chongqing Medical University from November 2013 to January 2022 were evaluated. PRC was determined by automated chemiluminescence immunoassay. The distribution characteristics of PRC were analyzed, and 8.2 mU/L was used as the low renin cutoff to evaluate whether renin was suppressed.Results:The median PRC was 1.6 mU/L (range, 0.4-41.5 mU/L). There were 116 patients with APA with PRC of ≤2 mU/L, 41 patients with 28.2 mU/L) in 8.0% (16/200) of the patients with APA. And PRC was not suppressed in 2.5% (5/200) of the patients with APA, resulting in a primary aldosteronism negative screening outcome.Conclusions:Although most patients with APA have low PRC, there are a small number (8%) of patients whose PRC has not been fully suppressed, which can lead to missed diagnoses during primary aldosteronism screening. While primary aldosteronism is highly suspected, further investigations are required to determine the diagnosis, even if PRC is not fully suppressed at screening.

N-methyladenosine (mA), a ubiquitous RNA modification, is installed by METTL3-METTL14 complex. The structure of the heterodimeric complex between the methyltransferase domains (MTDs) of METTL3 and METTL14 has been previously determined. However, the MTDs alone possess no enzymatic activity. Here we present the solution structure for the zinc finger domain (ZFD) of METTL3, the inclusion of which fulfills the methyltransferase activity of METTL3-METTL14. We show that the ZFD specifically binds to an RNA containing 5'-GGACU-3' consensus sequence, but does not to one without. The ZFD thus serves as the target recognition domain, a structural feature previously shown for DNA methyltransferases, and cooperates with the MTDs of METTL3-METTL14 for catalysis. However, the interaction between the ZFD and the specific RNA is extremely weak, with the binding affinity at several hundred micromolar under physiological conditions. The ZFD contains two CCCH-type zinc fingers connected by an anti-parallel β-sheet. Mutational analysis and NMR titrations have mapped the functional interface to a contiguous surface. As a division of labor, the RNA-binding interface comprises basic residues from zinc finger 1 and hydrophobic residues from β-sheet and zinc finger 2. Further we show that the linker between the ZFD and MTD of METTL3 is flexible but partially folded, which may permit the cooperation between the two domains during catalysis. Together, the structural characterization of METTL3 ZFD paves the way to elucidate the atomic details of the entire process of RNA mA modification.

Rectal cancer is one of the common cancers which poses a threat to the health of mankind. In recent years. Multi-modality treatment strategies for locally advanced rectal cancer improve the treatment efficiency. Accurate prediction of the treatment response after the neoadjuvant chemoradiotherapy (CRT) can guide more suitable treatment strategy. MERCURY study proved the prognostic value of post-CRT standard morphologic MRI(T2-weighted) assessment of tumor regression grade(TRG), and MRI assessment of circumferential resection margin can guide the definitive surgery. Compared with standard morphologic MRI (T2-weighted), functional MRI, including diffusion weighted imaging (DWI) and dynamic contrast enhanced (DCE) MRI, has shown more promising results for the prediction of therapeutic response in rectal cancer. The addition of diffusion-weighted images to T2-weighted images improves the accuracy of restaging examinations for determination of complete pathologic responders. DCE can reflect the tumor micro-vascular environment, and the change of perfusion in response to treatment. These images have the potential to improve the accuracy of therapeutic response in rectal cancer.
Chemoradiotherapy ; statistics & numerical data ; Contrast Media ; Diffusion Magnetic Resonance Imaging ; statistics & numerical data ; Humans ; Magnetic Resonance Imaging ; methods ; statistics & numerical data ; Margins of Excision ; Neoadjuvant Therapy ; statistics & numerical data ; Neoplasm Staging ; instrumentation ; methods ; statistics & numerical data ; Prognosis ; Rectal Neoplasms ; blood supply ; diagnostic imaging ; pathology

Objective To investigate the clinical effect of posterior pedicle screw fixation combined with anterior decompression and fusion for the treatment of thoracolumbar burst fractures.Methods The clinical data of 53 patients underwent posterior pedicle screw fixation and anterior decompression and fusion were retrospectively analyzed.The vertebral height,Cobb angle,vertebral tube volume,the Frankel gradient and Fugl -Meyer score were recorded and compared before and after treatment.Results 49 patients were followed up.At the last time of follow -up,the vertebral height,Cobb angle,vertebral tube volume all significantly improved (t =24.047,P <0.001;t =21.815,P <0.001;t =31.699,P <0.001).The Frankel gradient before treatment was:A 6 cases,B 18 cases,C 15 cases,D 10 cases,E 4 cases.After treatment,it came to 3 cases,8 cases,11 cases,17 cases,10 cases,respectively.There was significant difference before and after treatment (Z =2.997,P =0.003).There was significant difference in Fugl -Meyer score before and after treatment[(74.65 ±8.42)points,(90.26 ±9.17)points,respectively,P <0.001 ].Conclusion There is excellent effect on posterior pedicle screw fixation followed by anterior decompression and fusion for the treatment of thoracolumbar burst fractures.It is good for the recovery of motion and spinal function.