A 58-year-old man presented with the chief complaint of abdominal bloating and was incidentally found to have a liver tumor.As diagnostic imaging studies could not rule out malignancy,the patient underwent partial res...A 58-year-old man presented with the chief complaint of abdominal bloating and was incidentally found to have a liver tumor.As diagnostic imaging studies could not rule out malignancy,the patient underwent partial resection of segment 3 of the liver.The lesion pathologically showed eosinophilic proliferation,in addition to immunohistochemical positivity for human melanoma black 45 and Melan-A,thereby leading to the diagnosis of a hepatic perivascular epithelioid cell tumor(PEComa).A PEComa arising from the liver is relatively rare.Moreover,the name ‘PEComa' has not yet been widely recognized,and the same disease entity has been called epithelioid angiomyolipoma(EAML),further diminishing the recognition of PEComa.In addition,PEComa imaging findings mimic those of malignant liver tumors,and clinically,this tumor tends to enlarge.Therefore,a PEComa is difficult to diagnose.We conducted a systematic review of PEComa and EAML cases and discuss the results,including findings useful for differentiating perivascular epithelioid cell tumors from malignant liver tumors.展开更多
A new analytical solution for ground surface settlement induced by deep excavation is proposed based on the elastic half space Melan’s solution,and the analytical model is related to the physical and mechanical prope...A new analytical solution for ground surface settlement induced by deep excavation is proposed based on the elastic half space Melan’s solution,and the analytical model is related to the physical and mechanical properties of soil with the loading and unloading action during excavation process.The change law of earth pressure of the normal consolidation soil after the foundation pit excavation was analyzed,and elastic displacement calculation methods of analytic solution were further established given the influence of excavation and unloading.According to the change of stress state in the excavation process of foundation pit,the planar mechanical analysis model of the foundation excavation problem was established.By combining this model with the physical equations and geometric equations of plane strain problem with consideration of the loading and unloading modulus of soil,constitutive equation of the plane strain problem was also established.The loading and unloading modulus formula was obtained by using the parameter calculation method in Duncan-Chang curve model.The constitutive equation obtained from the model was used to calculate the soil stress state of each point to determine its loading and unloading modulus.Finally,the foundation pit displacement change after excavation was calculated,and thus the soil pressure distribution after retaining structure deformation.The theoretical results calculated by making corresponding programs were applied to engineering practice.By comparing the conventional calculation results with monitoring results,the practicability and feasibility of the calculation model were verified,which should provide a theoretical basis for similar projects.展开更多
Congenital melanocytic nevi(CMNs)are skin lesions characterized by benign melanocytic proliferations and present at birth or shortly thereafter.Large and giant CMNs,with a projected adult size≥20 cm and 40 cm in diam...Congenital melanocytic nevi(CMNs)are skin lesions characterized by benign melanocytic proliferations and present at birth or shortly thereafter.Large and giant CMNs,with a projected adult size≥20 cm and 40 cm in diameter respectively,are more likely to develop into malignant melanoma.In most cases,melanoma arising from congenital melanocytic nevus(CMN)is particularly aggressive.展开更多
The tRNA-derived fragments(tRFs)are small non-coding RNAs containing fewer than 50 nucleotides that are abundant in humans and have various biological functions.However,their roles and mechanisms in melanogenesis are ...The tRNA-derived fragments(tRFs)are small non-coding RNAs containing fewer than 50 nucleotides that are abundant in humans and have various biological functions.However,their roles and mechanisms in melanogenesis are unclear.In this study,we firstly investigated the change in the expres-sion profile of tRFs in melanocytes after UVB irradiation through tsRNA sequencing.UVB-induced melanogenesis led to the upregulation of 119 tRFs and the downregulation of 103 tRFs.展开更多
Melasma(chloasma)is a highly prevalent and cosmetically disfiguring pigmented skin disease that mainly manifests as bilateral irregular brown macules on sun-exposed areas of the face.[1]Although melasma causes no phys...Melasma(chloasma)is a highly prevalent and cosmetically disfiguring pigmented skin disease that mainly manifests as bilateral irregular brown macules on sun-exposed areas of the face.[1]Although melasma causes no physical discomfort,it poses a significant psychological burden on patients due to distressing cosmetic concerns.The sustained epidermal hypermelanization is a prominent pathological feature of melasma,which is usually considered to result from melanin overproduction by hyperactive melanocytes.[2]However,existing therapeutic interventions that suppress melanocytes and tyrosinase.展开更多
BACKGROUND Melanotic Xp11-associated tumors are rare mesenchymal-derived tumors. So far,most primary melanotic Xp11-associated tumors have been reported in the kidney, and reports of this tumor in the gastrointestinal...BACKGROUND Melanotic Xp11-associated tumors are rare mesenchymal-derived tumors. So far,most primary melanotic Xp11-associated tumors have been reported in the kidney, and reports of this tumor in the gastrointestinal tract are rare.CASE SUMMARY Here we describe the case of a 25-year-old woman who presented with a melanotic Xp11-associated tumor in the sigmoid colon. Colonoscopy revealed a large mucosal bulge in the sigmoid colon, approximately 32 cm inside the anus.The surface was rough with local erosion. The tumor was brittle on biopsy and bled easily. Computed tomography revealed thickening of the rectal wall with edema. Postoperative pathology indicated the likelihood of a perivascular epithelioid cell tumor. Histologically, the tumor comprised plump epithelioid cells with abundant clear to lightly eosinophilic cytoplasm and round nuclei arranged in an alveolar or trabecular pattern. The tumor cells were strongly positive for HMB-45, Melan-A, Cathepsin K, and TFE3 but negative for vimentin,smooth muscle actin, S100 protein, CD10, CK20, and desmin. The tumor cells had a low Ki-67 labeling index(approximately 2%). Fluorescence in situ hybridization revealed TFE3 fracture. Based on these histologic and immunohistochemical features, a diagnosis of melanotic Xp11-associated tumor of the sigmoid colon was made.CONCLUSION In summary, we report the clinicopathological features of a primary tumor that is extremely rare in the sigmoid colon and review the clinicopathological characteristics of melanotic Xp11-associated tumors, compatible with the very rare tumor termed "melanotic Xp11 translocation renal cancer" in all aspects.展开更多
Primary urethral malignant melanoma is an extremely rare malignancy with early metastasis and often delayed diagnosis, resulted in poor prognosis. Literature on this entity, especially with regard to urinary cytology ...Primary urethral malignant melanoma is an extremely rare malignancy with early metastasis and often delayed diagnosis, resulted in poor prognosis. Literature on this entity, especially with regard to urinary cytology is limited. We report here an extremely rare case of primary urethral malignant melanoma (MM) developed in a 95-year-old Japanese woman. A urinalysis showed macrophages containing brown granular pigments, and the urinary cytology was positive for atypical cells containing brown pigments suggestive of MM. Pathological examination of the biopsy specimen from the tumor revealed MM of the urethra. Immunohistochemically, the tumor cells showed strong cytoplasmic reactivities against antibodies, HMB-45 and Malan-A. Melanoma cells were immunohistochemically positive for c-Kit in their cytoplasm and cell membrane, although mutations in BRAF V600E and N/K-RAS were not detected. The urinary cytology and immunohistochemistry were useful for the rapid and accurate diagnosis for the urethral MM.展开更多
文摘A 58-year-old man presented with the chief complaint of abdominal bloating and was incidentally found to have a liver tumor.As diagnostic imaging studies could not rule out malignancy,the patient underwent partial resection of segment 3 of the liver.The lesion pathologically showed eosinophilic proliferation,in addition to immunohistochemical positivity for human melanoma black 45 and Melan-A,thereby leading to the diagnosis of a hepatic perivascular epithelioid cell tumor(PEComa).A PEComa arising from the liver is relatively rare.Moreover,the name ‘PEComa' has not yet been widely recognized,and the same disease entity has been called epithelioid angiomyolipoma(EAML),further diminishing the recognition of PEComa.In addition,PEComa imaging findings mimic those of malignant liver tumors,and clinically,this tumor tends to enlarge.Therefore,a PEComa is difficult to diagnose.We conducted a systematic review of PEComa and EAML cases and discuss the results,including findings useful for differentiating perivascular epithelioid cell tumors from malignant liver tumors.
基金Project(41672290)supported by the National Natural Science Foundation of ChinaProject(2016J01189)supported by the Natural Science foundation of Fujian Province,China
文摘A new analytical solution for ground surface settlement induced by deep excavation is proposed based on the elastic half space Melan’s solution,and the analytical model is related to the physical and mechanical properties of soil with the loading and unloading action during excavation process.The change law of earth pressure of the normal consolidation soil after the foundation pit excavation was analyzed,and elastic displacement calculation methods of analytic solution were further established given the influence of excavation and unloading.According to the change of stress state in the excavation process of foundation pit,the planar mechanical analysis model of the foundation excavation problem was established.By combining this model with the physical equations and geometric equations of plane strain problem with consideration of the loading and unloading modulus of soil,constitutive equation of the plane strain problem was also established.The loading and unloading modulus formula was obtained by using the parameter calculation method in Duncan-Chang curve model.The constitutive equation obtained from the model was used to calculate the soil stress state of each point to determine its loading and unloading modulus.Finally,the foundation pit displacement change after excavation was calculated,and thus the soil pressure distribution after retaining structure deformation.The theoretical results calculated by making corresponding programs were applied to engineering practice.By comparing the conventional calculation results with monitoring results,the practicability and feasibility of the calculation model were verified,which should provide a theoretical basis for similar projects.
基金funded by the National Natural Science Foundation of China(No.82204421 to Hanlin Zeng)the Innovative Research Team of High-Level Local Universities in Shanghai,China(No.SHSMU-ZLCX20211700 to Hanlin Zeng).
文摘Congenital melanocytic nevi(CMNs)are skin lesions characterized by benign melanocytic proliferations and present at birth or shortly thereafter.Large and giant CMNs,with a projected adult size≥20 cm and 40 cm in diameter respectively,are more likely to develop into malignant melanoma.In most cases,melanoma arising from congenital melanocytic nevus(CMN)is particularly aggressive.
基金supported by the National Natural Science Foundation of China(No.82103704)the Natural Science Foundation of Hunan Province(China)(No.2021JJ20089,2022JJ70148)+1 种基金Wisdom Accumulation and Talent Cultivation Project of the Third Xiangya Hospital of Central South Uni-versity,Hunan,China(No.YX202007)the Hunan Science and Technology Innovation Project(China)(No.2021RC3035).
文摘The tRNA-derived fragments(tRFs)are small non-coding RNAs containing fewer than 50 nucleotides that are abundant in humans and have various biological functions.However,their roles and mechanisms in melanogenesis are unclear.In this study,we firstly investigated the change in the expres-sion profile of tRFs in melanocytes after UVB irradiation through tsRNA sequencing.UVB-induced melanogenesis led to the upregulation of 119 tRFs and the downregulation of 103 tRFs.
基金National Natural Science Foundation of China(Nos.81972919,82273513)
文摘Melasma(chloasma)is a highly prevalent and cosmetically disfiguring pigmented skin disease that mainly manifests as bilateral irregular brown macules on sun-exposed areas of the face.[1]Although melasma causes no physical discomfort,it poses a significant psychological burden on patients due to distressing cosmetic concerns.The sustained epidermal hypermelanization is a prominent pathological feature of melasma,which is usually considered to result from melanin overproduction by hyperactive melanocytes.[2]However,existing therapeutic interventions that suppress melanocytes and tyrosinase.
基金Supported by The Key Research & Development and Transformation Project of Qinghai Province for 2018(No.2018-SF-113)
文摘BACKGROUND Melanotic Xp11-associated tumors are rare mesenchymal-derived tumors. So far,most primary melanotic Xp11-associated tumors have been reported in the kidney, and reports of this tumor in the gastrointestinal tract are rare.CASE SUMMARY Here we describe the case of a 25-year-old woman who presented with a melanotic Xp11-associated tumor in the sigmoid colon. Colonoscopy revealed a large mucosal bulge in the sigmoid colon, approximately 32 cm inside the anus.The surface was rough with local erosion. The tumor was brittle on biopsy and bled easily. Computed tomography revealed thickening of the rectal wall with edema. Postoperative pathology indicated the likelihood of a perivascular epithelioid cell tumor. Histologically, the tumor comprised plump epithelioid cells with abundant clear to lightly eosinophilic cytoplasm and round nuclei arranged in an alveolar or trabecular pattern. The tumor cells were strongly positive for HMB-45, Melan-A, Cathepsin K, and TFE3 but negative for vimentin,smooth muscle actin, S100 protein, CD10, CK20, and desmin. The tumor cells had a low Ki-67 labeling index(approximately 2%). Fluorescence in situ hybridization revealed TFE3 fracture. Based on these histologic and immunohistochemical features, a diagnosis of melanotic Xp11-associated tumor of the sigmoid colon was made.CONCLUSION In summary, we report the clinicopathological features of a primary tumor that is extremely rare in the sigmoid colon and review the clinicopathological characteristics of melanotic Xp11-associated tumors, compatible with the very rare tumor termed "melanotic Xp11 translocation renal cancer" in all aspects.
文摘Primary urethral malignant melanoma is an extremely rare malignancy with early metastasis and often delayed diagnosis, resulted in poor prognosis. Literature on this entity, especially with regard to urinary cytology is limited. We report here an extremely rare case of primary urethral malignant melanoma (MM) developed in a 95-year-old Japanese woman. A urinalysis showed macrophages containing brown granular pigments, and the urinary cytology was positive for atypical cells containing brown pigments suggestive of MM. Pathological examination of the biopsy specimen from the tumor revealed MM of the urethra. Immunohistochemically, the tumor cells showed strong cytoplasmic reactivities against antibodies, HMB-45 and Malan-A. Melanoma cells were immunohistochemically positive for c-Kit in their cytoplasm and cell membrane, although mutations in BRAF V600E and N/K-RAS were not detected. The urinary cytology and immunohistochemistry were useful for the rapid and accurate diagnosis for the urethral MM.
