As the most abundant and essential structural protein in the human body, collagen is ubiquitously present in the interstitium of nearly all solid organs, playing a crucial role in maintaining the structural integrity and functional stability of human tissues and organs. Disorders associated with collagen structure and metabolisms impose a significant burden on society and healthcare systems. Post-translational modifications (PTMs) are essential steps in collagen metabolism, and recent studies have indicated that aberrant regulation of PTMs plays a pivotal role in the pathogenesis and progress of collagen-related disorders, including liver, kidney, heart, lung, and skin fibrosis, as well as keloid. This review provides a comprehensive summary of the regulatory mechanisms of both traditional and novel PTMs in collagen metabolism and collagen-related diseases. Furthermore, we summarize the drugs that modulate PTMs and their effects, with the aim of elucidating the pathophysiology of collagen-related diseases and provide new insights for their diagnosis, prevention, and treatment.

Deep learning-based polyp image segmentation is helpful for assessing precancerous lesions. A colorectal polyp image segmentation model (RDG-Net) based on a dual-stage decoder is proposed to addresses the issues of poor segmentation performance due to unclear boundaries in colorectal polyp images and insufficient generalization ability for new samples. The model uses Res2Net-50 as the encoder to enhance the precision of image segmentation. The decoder has two stages:the first stage utilizes a 4-layer multi-scale feature aggregation module to integrate features extracted by the encoder at different stages,while the second stage enhances the image features output by the first stage of the decoder through a 3-layer parallel convolution fusion module and decodes them to a higher resolution as the model's final output. The model is trained using the CVC-ClinicDB and Kvasir-SEG training datasets,and tested using the CVC-ClinicDB and Kvasir-SEG test datasets,as well as the CVC300 and ETIS-LaribPolypDB datasets that are not involved in the training. The test results show that the proposed method has an average accuracy,precision,recall rate,Dice similarity coefficient,intersection over union and F2 score of 98.41％,94.25％,92.62％,93.42％,87.69％and 92.93％on the CVC-ClinicDB and Kvasir-SEG datasets,while 99.05％,87.79％,89.13％,88.39％,79.33％ and 88.82％ on the CVC300 and ETIS-LaribPolypDB datasets,respectively,demonstrating that RDG-Net model performs well in colorectal polyp region segmentation and has a high generalization performance on new datasets.

Objective:To investigate the correlation between serum growth differentiation factor 15 (GDF15) and the clinicopathological characteristics of patients with IgA nephropathy (IgAN), and further explore the relationship of GDF15 with the cardiac and renal prognosis of IgAN patients.Methods:It was a single-center retrospective cohort study. From January 2018 to December 2022, the relevant data were collected from patients who were diagnosed with primary IgAN at the Department of Nephrology, Beijing Anzhen Hospital Affiliated to Capital Medical University, and regularly followed up for at least 1 year. Serum samples were collected at admission and the baseline level of serum GDF15 was measured. Based on the median GDF15 level, IgAN patients were categorized into high-level GDF15 group and low-level GDF15 group, and their clinicopathological characteristics were compared. A multiple linear regression model was then constructed to identify independent factors associated with serum GDF15 level based on these comparisons. Subsequently, Kaplan-Meier survival analysis was performed to investigate the association between serum GDF15 level and the cardiorenal prognosis of IgAN patients.Results:A total of 104 IgAN patients were included in this study. The serum GDF15 level in these IgAN patients was 825.60 (556.84, 1 428.15) ng/L. Serum GDF15 level was positively correlated with 24 h urinary protein ( r=0.405, P<0.001), negatively correlated with estimated glomerular filtration rate (eGFR)( r=-0.606, P<0.001). The serum levels of GDF15 in patients with tubular atrophy or interstitial fibrosis (overall comparison among T0, T1, and T2, H=21.866, P<0.001), crescentic lesions (overall comparison among C0, C1, and C2, H=13.787, P=0.001), or intrarenal arteriolar lesions (overall comparison among none, mild, and moderate-to-severe, H=9.856, P=0.007) were significantly different. Compared with IgAN patients without tubular atrophy or interstitial fibrosis, those with Oxford classification T1 ( Z=-17.326, P=0.042) or T2 ( Z=-42.933, P<0.001) had higher serum GDF15 levels. Compared with IgAN patients without crescentic lesions, those with Oxford classification C2 had higher serum GDF15 levels ( Z=-45.929, P=0.001). Compared with IgAN patients without intrarenal arteriolar lesions, those with moderate-to-severe arteriolar sclerosis had higher serum GDF15 levels ( Z=-26.686, P=0.005). The median GDF15 was used as the cut-off value to divide IgAN patients into a high-level GDF15 group (≥825.60 ng/L, n=52) and a low-level GDF15 group (<825.60 ng/L, n=52). Compared to low-level GDF15 group, IgAN patients in high-level GDF15 group presented with a higher proportion of diabetes mellitus ( χ 2=9.420, P=0.002) and cardiovascular disease ( χ 2=7.792, P=0.005), a higher level of systolic blood pressure ( Z=-2.266, P=0.023), body mass index ( Z=-2.183, P=0.031), 24 h urinary protein ( Z=-3.485, P<0.001), blood total cholesterol ( Z=-2.002, P=0.045) and left ventricular mass index ( Z=-2.649, P=0.008), and a lower level of blood albumin ( Z=-3.053, P=0.002) and eGFR ( Z=6.480, P<0.001). Multiple linear regression analysis showed that serum GDF15 level was independently associated with systolic blood pressure (regression coefficient B=29.453, 95% CI 14.139–44.767, P<0.001), blood albumin ( B=-81.412, 95% CI -113.084–-49.740, P<0.001) and eGFR ( B=-9.797, 95% CI -17.554–-2.040, P=0.014). Moreover, IgAN patients in high-level GDF15 group exhibited significantly poorer cardiac and renal prognosis compared to low-level GDF15 group ( χ 2=9.955, P=0.002). Conclusion:High serum GDF15 level correlates with disease severity in IgAN, and high serum GDF15 level may suggest a poorer cardiorenal prognosis in IgAN patients.

Objective:To investigate the different clinical characteristics and prognosis of patients with diabetic nephropathy (DN) accompanied by IgA deposition diagnosed by renal biopsy.Methods:The study was a retrospective cohort study. Clinical and pathological data of patients diagnosed with DN through renal biopsy in Beijing Anzhen Hospital affiliated to Capital Medical University from January 1, 2010 to March 31, 2023 were retrospectively collected. The clinical and pathological characteristics and prognosis of DN patients with IgA deposition and DN control group patients without IgA deposition were compared. Immunofluorescence staining was used to detect the intensity of galactose-deficient IgA1 (Gd-IgA1) staining in renal tissue of DN patients with DN IgA deposition, and grouping was performed according to whether the staining intensity was≥2+. Enzyme linked immunosorbent assay was used to detect the serum level of Gd-IgA1 in patients. A 50% decrease in estimated glomerular filtration rate (eGFR) from baseline or progression to end-stage renal disease within 5 years was defined as a renal endpoint event, and Kaplan-Meier survival analysis and Log-rank test were used to compare the difference in cumulative incidence of renal endpoint events between two groups of patients.Results:A total of 101 DN patients were enrolled in this study, including 68 males (67.3%) and 33 females (32.7%), with age of (52.2±10.3) years and a median follow-up time of 13.5(4.8, 26.3) months. There were 44 patients with IgA deposition (43.6%) and 57 patients without IgA deposition (56.4%). Compared with DN control group, Kaplan-Meier analysis showed that DN patients with IgA deposition had a higher cumulative incidence of renal endpoint within 5 years ( χ2=6.473, P=0.011). The proportion of positive glomerular Gd-IgA1 (KM55) staining in the DN patients with IgA deposition was 54.5% (24/44), and immunofluorescence examination showed consistent distribution of Gd-IgA1 and IgA in the glomerular mesangial and capillary regions. The serum level of Gd-IgA1 in the glomerular Gd-IgA1 positive patients was significantly higher than that in those negative patients [(6 296.4± 1 535.4) μg/L vs. (4 057.4±1 082.0) μg/L, t=-3.037, P=0.010]. In DN patients with IgA deposition, the age of the subgroup with endpoint events was younger [(42.8±6.9) years vs. (53.3±9.4) years, t=-3.440, P=0.002], the duration of proteinuria was shorter [6.0(1.0, 22.0) months vs. 12.0(10.0, 36.0) months, Z=-2.150, P=0.032], and the proportion of patients with glomerular Gd-IgA1 staining intensity ≥2+ was higher [Fisher'exact test, 30.8%(4/13) vs. 0(0/20), P=0.017]. Kaplan-Meier survival analysis showed that patients with glomerular Gd-IgA1 staining intensity≥2+ had a significantly higher cumulative incidence of renal endpoint events ( χ2=4.846, P=0.028). Conclusion:DN patients with glomerular IgA deposition and Gd-IgA1 positivity may be associated with worse prognosis.

ObjectiveTo observe the effect of gene mutation on the effectiveness of arsenic-containing Chinese herbal compound formulas in the treatment of myelodysplastic syndromes （MDS） of different traditional Chinese medicine （TCM） patterns， so as to provide the basis for the clinical application. MethodsClinical data of 442 MDS patients who were treated with arsenic-containing herbal compound formulas were retrospectively collected， including the baseline demographic and clinical characteristics of the patients. Based on the TCM four examinations， the patients were divided into the spleen-kidney deficiency group as well as the qi-yin deficiency group， and according to the results of the next-generation sequencing （NGS） test， they were divided into the group with and without gene mutation respectively. The influence of gene mutation on the clinical effectiveness of patients with different TCM patterns was analyzed， the baseline demographic and clinical characteristics of the patients with different outcomes of the two TCM patterns were compared， and multivariate Logistic regression analysis was conducted on the influencing factors of the effective rate of MDS patients with gene mutation. ResultsA total of 190 cases were included in the spleen-kidney deficiency group （119 cases with gene mutation） and 43 cases in the qi-yin deficiency group （23 cases with gene mutation）. No statistically significant differences were noted in effectiveness assessment， total effective rate， and total response rate between the spleen-kidney deficiency group and the qi-yin deficiency group （P＞0.05）. In the spleen-kidney deficiency group， the total effective rate of MDS with gene mutation was 65.55% （78/119）， which was lower than 80.28% （57/71） of MDS without gene mutation， with statistical significance （P = 0.033）， while no statistical differences in effectiveness assessment and total response rate were noted （P＞0.05）. In the qi-yin deficiency group， no statistical differences were observed in effectiveness assessment， total effective rate， and total response rate of the patients in with or without gene mutation （P＞0.05）. In the spleen-kidney deficiency group with gene mutation， the rate of complex karyotype （P = 0.031） and the mutation rate of CBL gene （P = 0.032） in the ineffective population were higher than those in the effective population， while the mutation rate of DDX41 gene in the effective population was higher than that in the ineffective population （P = 0.033）. No statistically significant differences were found in other gene mutations， age， gender distribution， number of gene mutations， bone marrow hyperplasia degree， blast cell range， reticular fiber tissue proliferation or not， and prognosis of chromosomal abnormalities between the effective and ineffective populations （P＞0.05）. In the qi-yin deficiency group with gene mutation， no statistically significant differences were found in various items between populations with different outcomes （P＞0.05）. Multivariate Logistic regression analysis showed that complex karyotype， CBL mutation， and DDX41 mutation were independently associated with the effective rate of MDS with spleen-kidney deficiency and gene mutation （P＜0.05）. DDX41 mutation was an independent protective factor in the spleen-kidney deficiency group （OR＞1）， while complex karyotype and CBL mutation were independent risk factors （OR＜1）. ConclusionThe arsenic-containing TCM compound formulas exhibited better effectiveness in MDS with spleen-kidney deficiency pattern without mutation； and in MDS with spleen-kidney deficiency pattern without complex karyotypes， CBL mutation， and with DDX41 mutations. Furthermore， DDX41 mutation was an independent protective factor in the spleen-kidney deficiency group， while complex karyotype and CBL mutation were independent risk factors. In MDS with qi-yin deficiency pattern， gene mutation-related factors showed no significant impact on the effectiveness of arsenic-containing TCM compound formulas.

Objective:To investigate the different clinical characteristics and prognosis of patients with diabetic nephropathy (DN) accompanied by IgA deposition diagnosed by renal biopsy.Methods:The study was a retrospective cohort study. Clinical and pathological data of patients diagnosed with DN through renal biopsy in Beijing Anzhen Hospital affiliated to Capital Medical University from January 1, 2010 to March 31, 2023 were retrospectively collected. The clinical and pathological characteristics and prognosis of DN patients with IgA deposition and DN control group patients without IgA deposition were compared. Immunofluorescence staining was used to detect the intensity of galactose-deficient IgA1 (Gd-IgA1) staining in renal tissue of DN patients with DN IgA deposition, and grouping was performed according to whether the staining intensity was≥2+. Enzyme linked immunosorbent assay was used to detect the serum level of Gd-IgA1 in patients. A 50% decrease in estimated glomerular filtration rate (eGFR) from baseline or progression to end-stage renal disease within 5 years was defined as a renal endpoint event, and Kaplan-Meier survival analysis and Log-rank test were used to compare the difference in cumulative incidence of renal endpoint events between two groups of patients.Results:A total of 101 DN patients were enrolled in this study, including 68 males (67.3%) and 33 females (32.7%), with age of (52.2±10.3) years and a median follow-up time of 13.5(4.8, 26.3) months. There were 44 patients with IgA deposition (43.6%) and 57 patients without IgA deposition (56.4%). Compared with DN control group, Kaplan-Meier analysis showed that DN patients with IgA deposition had a higher cumulative incidence of renal endpoint within 5 years ( χ2=6.473, P=0.011). The proportion of positive glomerular Gd-IgA1 (KM55) staining in the DN patients with IgA deposition was 54.5% (24/44), and immunofluorescence examination showed consistent distribution of Gd-IgA1 and IgA in the glomerular mesangial and capillary regions. The serum level of Gd-IgA1 in the glomerular Gd-IgA1 positive patients was significantly higher than that in those negative patients [(6 296.4± 1 535.4) μg/L vs. (4 057.4±1 082.0) μg/L, t=-3.037, P=0.010]. In DN patients with IgA deposition, the age of the subgroup with endpoint events was younger [(42.8±6.9) years vs. (53.3±9.4) years, t=-3.440, P=0.002], the duration of proteinuria was shorter [6.0(1.0, 22.0) months vs. 12.0(10.0, 36.0) months, Z=-2.150, P=0.032], and the proportion of patients with glomerular Gd-IgA1 staining intensity ≥2+ was higher [Fisher'exact test, 30.8%(4/13) vs. 0(0/20), P=0.017]. Kaplan-Meier survival analysis showed that patients with glomerular Gd-IgA1 staining intensity≥2+ had a significantly higher cumulative incidence of renal endpoint events ( χ2=4.846, P=0.028). Conclusion:DN patients with glomerular IgA deposition and Gd-IgA1 positivity may be associated with worse prognosis.

Deep learning-based polyp image segmentation is helpful for assessing precancerous lesions. A colorectal polyp image segmentation model (RDG-Net) based on a dual-stage decoder is proposed to addresses the issues of poor segmentation performance due to unclear boundaries in colorectal polyp images and insufficient generalization ability for new samples. The model uses Res2Net-50 as the encoder to enhance the precision of image segmentation. The decoder has two stages:the first stage utilizes a 4-layer multi-scale feature aggregation module to integrate features extracted by the encoder at different stages,while the second stage enhances the image features output by the first stage of the decoder through a 3-layer parallel convolution fusion module and decodes them to a higher resolution as the model's final output. The model is trained using the CVC-ClinicDB and Kvasir-SEG training datasets,and tested using the CVC-ClinicDB and Kvasir-SEG test datasets,as well as the CVC300 and ETIS-LaribPolypDB datasets that are not involved in the training. The test results show that the proposed method has an average accuracy,precision,recall rate,Dice similarity coefficient,intersection over union and F2 score of 98.41％,94.25％,92.62％,93.42％,87.69％and 92.93％on the CVC-ClinicDB and Kvasir-SEG datasets,while 99.05％,87.79％,89.13％,88.39％,79.33％ and 88.82％ on the CVC300 and ETIS-LaribPolypDB datasets,respectively,demonstrating that RDG-Net model performs well in colorectal polyp region segmentation and has a high generalization performance on new datasets.

Objective:To investigate the correlation between serum growth differentiation factor 15 (GDF15) and the clinicopathological characteristics of patients with IgA nephropathy (IgAN), and further explore the relationship of GDF15 with the cardiac and renal prognosis of IgAN patients.Methods:It was a single-center retrospective cohort study. From January 2018 to December 2022, the relevant data were collected from patients who were diagnosed with primary IgAN at the Department of Nephrology, Beijing Anzhen Hospital Affiliated to Capital Medical University, and regularly followed up for at least 1 year. Serum samples were collected at admission and the baseline level of serum GDF15 was measured. Based on the median GDF15 level, IgAN patients were categorized into high-level GDF15 group and low-level GDF15 group, and their clinicopathological characteristics were compared. A multiple linear regression model was then constructed to identify independent factors associated with serum GDF15 level based on these comparisons. Subsequently, Kaplan-Meier survival analysis was performed to investigate the association between serum GDF15 level and the cardiorenal prognosis of IgAN patients.Results:A total of 104 IgAN patients were included in this study. The serum GDF15 level in these IgAN patients was 825.60 (556.84, 1 428.15) ng/L. Serum GDF15 level was positively correlated with 24 h urinary protein ( r=0.405, P<0.001), negatively correlated with estimated glomerular filtration rate (eGFR)( r=-0.606, P<0.001). The serum levels of GDF15 in patients with tubular atrophy or interstitial fibrosis (overall comparison among T0, T1, and T2, H=21.866, P<0.001), crescentic lesions (overall comparison among C0, C1, and C2, H=13.787, P=0.001), or intrarenal arteriolar lesions (overall comparison among none, mild, and moderate-to-severe, H=9.856, P=0.007) were significantly different. Compared with IgAN patients without tubular atrophy or interstitial fibrosis, those with Oxford classification T1 ( Z=-17.326, P=0.042) or T2 ( Z=-42.933, P<0.001) had higher serum GDF15 levels. Compared with IgAN patients without crescentic lesions, those with Oxford classification C2 had higher serum GDF15 levels ( Z=-45.929, P=0.001). Compared with IgAN patients without intrarenal arteriolar lesions, those with moderate-to-severe arteriolar sclerosis had higher serum GDF15 levels ( Z=-26.686, P=0.005). The median GDF15 was used as the cut-off value to divide IgAN patients into a high-level GDF15 group (≥825.60 ng/L, n=52) and a low-level GDF15 group (<825.60 ng/L, n=52). Compared to low-level GDF15 group, IgAN patients in high-level GDF15 group presented with a higher proportion of diabetes mellitus ( χ 2=9.420, P=0.002) and cardiovascular disease ( χ 2=7.792, P=0.005), a higher level of systolic blood pressure ( Z=-2.266, P=0.023), body mass index ( Z=-2.183, P=0.031), 24 h urinary protein ( Z=-3.485, P<0.001), blood total cholesterol ( Z=-2.002, P=0.045) and left ventricular mass index ( Z=-2.649, P=0.008), and a lower level of blood albumin ( Z=-3.053, P=0.002) and eGFR ( Z=6.480, P<0.001). Multiple linear regression analysis showed that serum GDF15 level was independently associated with systolic blood pressure (regression coefficient B=29.453, 95% CI 14.139–44.767, P<0.001), blood albumin ( B=-81.412, 95% CI -113.084–-49.740, P<0.001) and eGFR ( B=-9.797, 95% CI -17.554–-2.040, P=0.014). Moreover, IgAN patients in high-level GDF15 group exhibited significantly poorer cardiac and renal prognosis compared to low-level GDF15 group ( χ 2=9.955, P=0.002). Conclusion:High serum GDF15 level correlates with disease severity in IgAN, and high serum GDF15 level may suggest a poorer cardiorenal prognosis in IgAN patients.

ObjectiveMyelodysplastic syndromes （MDS） is a group of clonal hematopoietic stem cell disorders，and this study aims to investigate the expression of hypoxia-inducible factor-1α（HIF-1α） in the bone marrow cells of patients with MDS and its correlation with the clinical features of MDS，the therapeutic efficacy of arsenic-containing Chineseherbal compound，and the survival prognosis. MethodAccording to the inclusion and exclusion criteria，27 MDS patients treated with arsenic-containing Chinese herbal compound in the Department of Hematology，Xiyuan Hospital，China Academy of Chinese Medical Sciences from January 2022 to September 2022 were included，and their bone marrow samples were collected by myelotomy. HIF-1α expression level in bone marrow cells was detected by real-time polymerase chain reaction （PCR） to analyze its correlation with clinical features，and logistic and Cox regression was used to analyze the risk factors affecting the efficacy and prognostic survival of MDS patients. ResultThe HIF-1α mRNA expression level was lower in bone marrow cells of MDS patients than in healthy subjects. HIF-1α was positively correlated with the degree of myelodysplasia（r=0.384，P<0.05） and bone marrow granulocytic system%（G%）（r=0.560，P<0.01）. Logistic regression showed that HIF-1α was a risk factor for the prognosis in the follow-up of the efficacy of treatment（P<0.05）and Cox regression showed that HIF-1α was an independent factor affecting the survival prognosis of MDS patients ［odds ratio（OR）=398.968，95% confidence interval（CI）（1.281，116 858.743），P<0.05］. ConclusionThe level of HIF-1α expression in bone marrow cells of MDS patients was closely related to the degree of clinical myelodysplasia and G%，and HIF-1α was a risk factor for the efficacy for and survival prognosis of MDS patients.

BACKGROUND:After the internal fixation of cannulated screws in femoral neck fractures,because the affected limb is often unable to bear weight in the short term and the implants with high stiffness have a stress shielding effect on the fracture end,it is easy to cause osteoporosis of the affected limb and changes in the biomechanical distribution of the proximal femur,the incidence of osteonecrosis of the femoral head is high after surgery.At present,few studies have been conducted on the biomechanical effects of osteoporosis at the proximal end of the femur occurring after femoral neck fracture surgery on femoral neck fracture treated with cannulated screws. OBJECTIVE:Using finite element analysis,to investigate the biomechanical effects of osteoporosis occurring after femoral neck fracture surgery on femoral neck fracture treated with cannulated screws and explore the role of biomechanical factors in osteonecrosis of the femoral head. METHODS:Based on the obtained CT scan data of the femur in a patient with a femoral neck fracture,a proximal femoral model for internal fixation for femoral neck fracture was established by Mimics 19.0,3-Matic,UG 11.0,Hypermesh 14.0,and Abaqus software.One finite element model of the proximal femur without osteoporosis and three finite element models of the proximal femur with osteoporosis were analyzed using Abaqus software.The stress,contact pressure,displacement peak and cloud map under different components of the four models were measured and analyzed,and the internal stress changes and distribution of the femoral head were compared and analyzed. RESULTS AND CONCLUSION:The stresses and contact pressures of the femoral head and lower anterior cannulated screws varied more with the degree of osteoporosis.The peak displacement of the four models increased slowly with the degree of osteoporosis.By one-way analysis of variance,there was no significant effect of the degree of osteoporosis on the peak stress,contact pressure,and displacement of the different components.The internal stress distribution of the femoral head changed with the degree of osteoporosis.Changes in the biomechanical environment of the proximal femur have an important impact on osteonecrosis of the femoral head.