Deposition of pigment in the intestinal mucosa is commonly observed by the endoscopist, especially within the colon, and particularly during investigations for constipation. Pigment may also be detected in the small i...Deposition of pigment in the intestinal mucosa is commonly observed by the endoscopist, especially within the colon, and particularly during investigations for constipation. Pigment may also be detected in the small intestine. Although labeled as melanosis, electron microscopy and X-ray analytical methods have provided evidence that this pigment is not melanin at all, but lipofuscin. Often, herbal remedies or anthracene containing laxatives are often historically implicated, and experimental studies in both humans and animal models have also confirmed the intimate relationship with these pharmacological or pseudo-pharmacological remedies. The appearance of melanosis coli during colonoscopy is largely due to pigment granule deposition in macrophages located in the colonic mucosa. The pigment intensity is not uniform, being more intense in the cecum and proximal colon compared to the distal colon. Possibly, this reflects higher luminal concentrations of an offending agent in the proximal compared to distal colon, differential absorption along the length of the colon, or finally, differences in macrophage distribution within the colon. Mucosal lymphoid aggregates normally display a distinct absence of pigment producing a "starry sky" appearance, especially in the rectosigmoid region. Interestingly, some focal, usually sessile, colonic mucosal neoplastic lesions, rather than submucosal lesions, may be better appreciated as pigment deposition may be absent or limited. If detected, removal and further histopathologic analysis of the polyp may be facilitated.展开更多
In biology,redox reactions are essential and sometimes harmful,and therefore,iron metabolism is tightly regulated by cuproproteins.Since the state of copper in iron overload syndromes remains unclear,we investigated w...In biology,redox reactions are essential and sometimes harmful,and therefore,iron metabolism is tightly regulated by cuproproteins.Since the state of copper in iron overload syndromes remains unclear,we investigated whether copper metabolism is altered in these syndromes.Eleven patients with iron overload syndromes participated in this study.The clinical diagnoses were aceruloplasminemia (n=2),hemochromatosis (n=5),ferroportin disease (n=2),and receiving excess intravenous iron supplementation (n=2).Liver specimens were analyzed using a light microscope and transmission electron microscope equipped with an X-ray analyzer.In addition to a large amount of iron associated with oxygen and phosphorus,the iron-rich hemosiderins of hepatocytes and Kupffer cells contained small amounts of copper and sulfur,regardless of disease etiology.Two-dimensional imaging clearly showed that cuproproteins were distributed homogenously with iron complexes within hemosiderins.Copper stasis was unlikely in noncirrhotic patients.The enhanced induction of cuproproteins by excess iron may contribute to copper accumulation in hemosiderins.In conclusion,we have demonstrated that copper accumulates in hemosiderins in iron overload conditions,perhaps due to alterations in copper metabolism.展开更多
目的:探讨中枢神经系统表面铁沉积(superficial siderosis of the central nervous system,SSCNS)的发病机制、病因、临床和影像学特点及治疗方法。方法:报道1例经临床、影像学及活检病理确诊的SSCNS病例,通过检索CNKI、万方、维普数据...目的:探讨中枢神经系统表面铁沉积(superficial siderosis of the central nervous system,SSCNS)的发病机制、病因、临床和影像学特点及治疗方法。方法:报道1例经临床、影像学及活检病理确诊的SSCNS病例,通过检索CNKI、万方、维普数据库,对国内报道的62例SSCNS患者的临床资料进行分类统计。结果:本文报道的患者主要表现为双耳感音性听力减退、小脑性共济失调、认知减退及锥体束征,MRI具有典型中枢神经系统表面低信号改变,病理活检普鲁士蓝染色阳性,最终诊断为病因不明的经典型幕下铁沉积。检索出的病例也多以听力下降(52/62例)、共济失调(55/62例)、锥体束征(40/62例)等典型SSCNS三联征为主要表现,影像学上均有相应改变,大多数病因不明(43/62例),其中9例行驱铁治疗,6例行手术治疗,转归差异较大。结论:SSCNS是一种罕见的变性疾病,典型临床表现结合MRI磁敏感序列检查是目前的主要诊断手段,活检病理有助于确诊,但目前尚无明确有效治疗方法。展开更多
文摘Deposition of pigment in the intestinal mucosa is commonly observed by the endoscopist, especially within the colon, and particularly during investigations for constipation. Pigment may also be detected in the small intestine. Although labeled as melanosis, electron microscopy and X-ray analytical methods have provided evidence that this pigment is not melanin at all, but lipofuscin. Often, herbal remedies or anthracene containing laxatives are often historically implicated, and experimental studies in both humans and animal models have also confirmed the intimate relationship with these pharmacological or pseudo-pharmacological remedies. The appearance of melanosis coli during colonoscopy is largely due to pigment granule deposition in macrophages located in the colonic mucosa. The pigment intensity is not uniform, being more intense in the cecum and proximal colon compared to the distal colon. Possibly, this reflects higher luminal concentrations of an offending agent in the proximal compared to distal colon, differential absorption along the length of the colon, or finally, differences in macrophage distribution within the colon. Mucosal lymphoid aggregates normally display a distinct absence of pigment producing a "starry sky" appearance, especially in the rectosigmoid region. Interestingly, some focal, usually sessile, colonic mucosal neoplastic lesions, rather than submucosal lesions, may be better appreciated as pigment deposition may be absent or limited. If detected, removal and further histopathologic analysis of the polyp may be facilitated.
文摘In biology,redox reactions are essential and sometimes harmful,and therefore,iron metabolism is tightly regulated by cuproproteins.Since the state of copper in iron overload syndromes remains unclear,we investigated whether copper metabolism is altered in these syndromes.Eleven patients with iron overload syndromes participated in this study.The clinical diagnoses were aceruloplasminemia (n=2),hemochromatosis (n=5),ferroportin disease (n=2),and receiving excess intravenous iron supplementation (n=2).Liver specimens were analyzed using a light microscope and transmission electron microscope equipped with an X-ray analyzer.In addition to a large amount of iron associated with oxygen and phosphorus,the iron-rich hemosiderins of hepatocytes and Kupffer cells contained small amounts of copper and sulfur,regardless of disease etiology.Two-dimensional imaging clearly showed that cuproproteins were distributed homogenously with iron complexes within hemosiderins.Copper stasis was unlikely in noncirrhotic patients.The enhanced induction of cuproproteins by excess iron may contribute to copper accumulation in hemosiderins.In conclusion,we have demonstrated that copper accumulates in hemosiderins in iron overload conditions,perhaps due to alterations in copper metabolism.
文摘目的:探讨中枢神经系统表面铁沉积(superficial siderosis of the central nervous system,SSCNS)的发病机制、病因、临床和影像学特点及治疗方法。方法:报道1例经临床、影像学及活检病理确诊的SSCNS病例,通过检索CNKI、万方、维普数据库,对国内报道的62例SSCNS患者的临床资料进行分类统计。结果:本文报道的患者主要表现为双耳感音性听力减退、小脑性共济失调、认知减退及锥体束征,MRI具有典型中枢神经系统表面低信号改变,病理活检普鲁士蓝染色阳性,最终诊断为病因不明的经典型幕下铁沉积。检索出的病例也多以听力下降(52/62例)、共济失调(55/62例)、锥体束征(40/62例)等典型SSCNS三联征为主要表现,影像学上均有相应改变,大多数病因不明(43/62例),其中9例行驱铁治疗,6例行手术治疗,转归差异较大。结论:SSCNS是一种罕见的变性疾病,典型临床表现结合MRI磁敏感序列检查是目前的主要诊断手段,活检病理有助于确诊,但目前尚无明确有效治疗方法。
