Detection of apoptosis in keloids and a comparative study on apoptosis between keloids, hypertrophic scars, normal healed flat scars, and dermatofibroma.

Recent studies have suggested that the regulation of apoptosis during wound healing is important in scar establishment and the development of pathological scarring. In this study, we demonstrate that keloid fibroblasts can be identified as apoptotic cells because of their highly condensed chromatin and discrete nuclear fragments. To further reveal the phenomenon of apoptosis, we quantified the number of terminal deoxynucleotide transferase-mediated dUTP nick-end labeling (TUNEL)-positive cells in surgically resected tissues of keloids (N = 10), hypertrophic scars (N = 10), normal healed flat scars (N = 10), and dermatofibroma (N = 10). The number of TUNEL-positive cells was relatively low, but was significantly higher for the keloid group compared with the normally healed flat scar group (p = 0.004), suggesting reduced cell survival and increased apoptotic cell death in a subpopulation of keloid fibroblasts. Furthermore, the number of TUNEL-positive cells was significantly higher for the keloid group compared with the dermatofibroma group (p = 0.044), suggesting that a subpopulation of keloid fibroblasts may suppress tumorgenicity at a greater rate than dermatofibroma by undergoing cell death. Hypertrophic scars had significantly higher levels of apoptosis than normally healed flat scars (p = 0.033). Therefore, these results suggest that selected fibroblasts in keloids and hypertrophic scars undergo apoptosis, which may play a role in the process of pathological scarring.

Collagen alteration in vascular remodeling by hemodynamic factors.

The collagen alterations in the vascular wall remodeled by hemodynamic change were investigated by electron microscopy and immunohistochemistry. The left anterior descending coronary artery (LAD) without a myocardial bridge (MB) showed both lower matrix metalloproteinase-1 (MMP-1) expression and a smaller extent of spiraled collagen (SC) distribution than the LAD wall with MB, in which the intima was influenced by high shear stress. In the wall of the varicose great saphenous vein (GSV) the expression of MMP-1 was lower, while the expression of prolyl 4-hydroxylase was higher, than in the normal GSV. The extent of SC distribution in the intima and media of the varicose GSV was smaller than that in the normal GSV. An analogous difference in results was demonstrated between the portal vein (PV) of patients with liver cirrhosis and normal PV. However, the levels of expression of MMP-2, MMP-9 and tissue inhibitors of MMP (TIMPs) in these pathologic vessels were not different from those in the corresponding normal vessels. The results indicate that hemodynamic forces such as shear stress and increased intravascular blood pressure contribute to the collagen alterations in the vascular wall, which may lead to vascular wall remodeling.

Collagen and elastin degradation by matrix metalloproteinases and tissue inhibitors of matrix metalloproteinase in aortic dissection.

The degradation of collagen fibrils and elastic fibers in 21 cases of acute aortic dissection (AD) was ultrastructurally and immunohistochemically investigated; and the expression of the catabolic matrix metalloproteinases (MMPs)-1, -2, -3, and -9 and their inhibitors, the tissue inhibitors of matrix metalloproteinase (TIMPs)-1 and -2, was studied. The features of the entry site of the dissection (ES; 21 ascending aortas) were compared with those of fully remote sites (RS; 19 nondissected abdominal aortas) and the ascending aortas from 10 control cases. By electron microscopy, the medial layer at the ES and adjacent intact aortic wall demonstrated spirally thickened collagen fibrils with a typical banding pattern that were almost always colocalized with elastic lamellae, which often exhibited attenuation, fragmentation, or disruption. In addition, the basement membrane surrounding the smooth muscle cells (SMCs) comprising the media was frequently thinned or lost at the ES. These findings were rarely seen at the RS or in the aortas of controls. Immunohistochemically, the expression of MMP-1 was significantly in the cytoplasm of SMCs of both the intima and media at the ES and adjacent intact wall, and significant expression of MMP-2 and -9 was found in SMCs of the intima compared with the RS and controls. Significant expression of TIMP-1 and -2 was demonstrated in the cytoplasm of SMCs at the ES and adjacent intact wall compared with that at the RS and the control specimens. These findings suggest that the degradation of proteins associated with fibrosis and the occurrence of AD are not merely coincident, but rather that AD is induced by alterations of the extracellular matrix caused by changes of SMCs at a segment of the ascending aorta made vulnerable through hemodynamic stress, especially that caused by hypertension.

Enhanced expression of caspase-3 in hypertrophic scars and keloid: induction of caspase-3 and apoptosis in keloid fibroblasts in vitro.

Recent studies have suggested that the regulation of apoptosis during wound healing is important in scar establishment and development of pathological scarring. To examine the phenomenon of apoptosis and its involvement in the process of pathological scarring, we immunohistochemically quantified differential levels of expression of caspase-3 and -2, which are activated during apoptosis in vitro, in surgical resected scar tissues. We divided 33 cases of normally healed flat scars and 18 cases of pathological scars (15 cases of hypertrophic scars and 3 cases of keloid) into three groups (S1 = <10 months' duration; S2 = 10 to 40 months' duration; and S3 = >40 months' duration) according to the duration of scar. In all three groups examined, the semiquantitative scores for caspase-3 staining were significantly higher for the combination of hypertrophic scars and keloid as a group compared with normally healed flat scars, suggesting reduced cell survival and increased apoptotic cell death in hypertrophic scars and keloid. Apoptosis and caspase proteolytic activities were examined in vitro using two flat scar-derived fibroblast lines (FSFB-1 and -2) and two keloid-derived fibroblast lines (KFB-1 and -2). After 24 hours of serum deprivation, apoptotic cells were significantly increased in both KFB lines, whereas serum deprivation of FSFB-1 cells did not result in a significant increase in apoptotic cell number. After serum deprivation, significant increases in caspase-3 proteolytic activities were detected in both KFB lines compared with both FSFB lines. In contrast, no significant differences with caspase-8 activity were observed between similarly treated KFB and FSFB lines. Furthermore, serum deprivation-induced apoptosis of KFB-2 cells was significantly inhibited by the caspase-3 inhibitor Ac-Asp-Glu-Val-Asp-fluoromethyl ketone (DEVD-FMK), indicating that caspase-3 is important for serum deprivation-induced apoptosis in KFB-2 cells. Considering the role of caspase-3 as a key effector molecule in the execution of apoptotic stimuli, our results suggested that enhanced expression of caspase-3 in hypertrophic scars and keloid induces apoptosis of fibroblasts, which may play a role in the process of pathological scarring.

An ACTH-producing pituitary carcinoma developing Cushing's disease.

An autopsy case of an ACTH-producing pituitary carcinoma in a 59-year-old man who developed Cushing's disease is reported. The surgically removed pituitary tumor was diagnosed as chromophobe adenoma, however, pulmonary metastases appeared 2 years after the operation. Autopsy revealed a residual pituitary tumor in the sella turcica with systemic metastases to the lungs, liver, pulmonary lymph nodes, hypothalamus, dura mater, and the subarachnoid space of the midbrain and spinal cord. Immunohistochemistry revealed ACTH positivity in the tumor cells. Further immunohistochemical study showed positive high expression of Ki-67 in the tumor removed at surgery as well as in the autopsied tumor. Ki-67 labeling index provided valuable information about the invasive and proliferative potential compared to noninvasive benign pituitary adenoma.

The effects of a myocardial bridge on coronary atherosclerosis and ischaemia.

The term myocardial bridge (MB) describes the surprisingly common situation in which part of the left anterior descending coronary artery (LAD), running in epicardial adipose tissue, is covered by a bridge of myocardial tissue. The presence of an MB may influence arterial tissue through the alteration of haemodynamic forces by the myocardial contraction of the bridge itself. Histopathologically and ultrastructurally, any manifestations of atherosclerosis elsewhere in the LAD are suppressed in the intima beneath the MB. By scanning electron microscopy, abrupt changes in endothelial cell morphology indicate that the intima beneath the bridge is protected by haemodynamic factors. Furthermore, the closer the bridge to the left coronary ostium, the greater the extent of proximal intimal thickening. In parallel with this, considering the occurrence of myocardial infarction in cases of proximal MB together with previous reports on relationships between MB and coronary ischaemia, it appears that anatomical characteristics such as the location, length, and thickness of the MB have a bearing on the effects of this abnormality. When the pathologist examines the heart at autopsy, this quite common condition should be borne in mind, in view of its potential but complex relationship to atherosclerosis and ischaemic heart disease.

Distribution and synthesis of apolipoprotein J in the atherosclerotic aorta.

The distribution of apolipoprotein (apo) J during the development of atherosclerosis in the human aorta was evaluated by immununohistochemical observation, together with the other apolipoprotein A-I, A-II, B, C-III, and E. Although apoJ was never observed in the normal aorta (ie, without any intimal lesions or intimal thickening), it was distributed not only in the intima but also in the media of aortas with diffuse, intimal thickening or atherosclerotic lesions. Double immunostaining with antibodies for apoJ and alpha-smooth muscle actin revealed apoJ deposition in smooth muscle cells (SMCs) or the aortic stroma in the vicinity of SMCs. The extent of apoJ distribution in the aortic wall increased with the degree of atherosclerosis development. In addition, the distribution pattern of apoJ was very similar to that of apoA-I and E. In situ hybridization with human apoJ cDNA demonstrated intense signals in cells scattered within the subendothelial space and medial SMCs of the aorta with advanced atherosclerosis but not in those of the normal aorta without intimal thickening. Furthermore, reverse transcriptase-polymerase chain reaction of the cultured human aortic SMCs revealed apoJ mRNA expression in these cells. The results indicate that apoJ in the aortic wall originates from not only apoJ circulated in the plasma but also apoJ produced by SMCs in the aortic wall. Considering the similarities of the distribution between apoJ and apo-A-I or E, we hypothesize that apoJ possibly has a protective role against human atherosclerosis by its involvement with cholesterol transport from the aortic wall to the liver.

Absence of atherosclerosis evolution in the coronary arterial segment covered by myocardial tissue in cholesterol-fed rabbits.

The evolution of atherosclerotic lesions is suppressed in the intima of the human coronary artery, beneath myocardial bridges. To elucidate the mechanism of the protective effect, we investigated morphological changes using the rabbit coronary artery as a model. Rabbit fed a 1%-cholesterol diet were killed at intervals up to 20 weeks. Two short segments of the left coronary arteries running in the epicardial adipose tissue (EpiLAD) and subsequently running in the myocardium (MyoLAD) were compared morphologically. The intima of the EpiLAD had flat endothelial cells with a polygonal shape, and demonstrated raised atherosclerotic lesions with increase in serum cholesterol level. In contrast, the intima of the MyoLAD was free of atherosclerotic lesions throughout the study, and the endothelial cells were spindle-shaped and engorged. While ferritin particles reached only the surroundings of the internal elastic lamina in the MyoLAD, they permeated into the media of the EpiLAD. We suggest that myocardial bridges suppress coronary atherosclerosis by an alteration of endothelial permeability, which may be due to changes in haemodynamic force tending towards a higher shear stress. The data provide an insight into the relationship between haemodynamics and the development of coronary atherosclerosis.

Spiraled collagen in the major blood vessels.

Vascular spiraled collagen (SC) was investigated by electron microscopic and immunohistochemical means in anatomically corresponding pairs of the major arteries and veins under normal or morbid condition in 45 autopsies. The frequency and extent of SC were marked in the veins, compared with the arteries. SC was particularly noted in the left anterior descending coronary artery beneath a myocardial bridge, which had been free from atherosclerosis, in contrast to those sites in the nonbridged vessel, which is always involved by atherosclerosis. SC was similarly conspicuous in the normal great saphenous vein, when compared with the phlebosclerotic vessel. The diameters of SC increased with the age of the patient. Immunohistochemical examination of matrix metalloproteinases (MMP-1, -2, and -3) revealed significant expression of MMP-1 in smooth muscle cells (SMCs) of vascular wall in which SCs was abundant, whereas tissue inhibitor of MMP-1 was absent in SMCs regardless of the presence of SC. Together with the frequent spatial association of SC with degraded elastic fibers and contractile-type SMCs, the present results indicate that whereas normal collagen fibrils are unilaterally degraded at extracellular spaces by interstitial enzymes and are possibly followed by their assembly to form SC, SMCs remain stationary in cell activities during aging. We conclude that SC is formed preferentially in the normal blood vessels through a physiologic degradation of normal collagen fibrils.

Myocardial ischemia due to vascular systemic amyloidosis: a quantitative analysis of autopsy findings on stenosis of the intramural coronary arteries.

A case is reported of a 65 year old man who suffered myocardial ischemia resulting from extensive stenosis of the intramural coronary arteries secondary to systemic vascular involvement by primary amyloidosis. In the myocardium, there were multiple fibrotic foci scattered mainly in the subendocardial region of the ventricle. Intramural coronary arteries were stenotic or occlusive due to amyloid-induced luminal narrowing, but there was no significant stenosis of the epicardial coronary arteries. Quantitative analysis of amyloid deposits in the intramural coronary arteries demonstrated that occlusive arteries were predominant in the surrounding area of myocardial fibrosis, and the extent of coronary stenosis by amyloid deposition was significantly more severe than in hearts of the five control patients who had coronary amyloidosis without myocardial fibrosis. These results indicate that myocardial fibrosis originates from coronary ischemia due to vascular amyloid deposition. This is the first time that the relationship between myocardial lesions and coronary amyloid deposition has been elucidated using histopathologic quantitative analysis.

Concurrent pulmonary arterial dissection and saccular aneurysm associated with primary pulmonary hypertension.

We report concurrent pulmonary arterial dissection and saccular aneurysm resulting from primary pulmonary hypertension in a 26-year-old man. The pulmonary trunk was dissected 9 cm along its entire circumference, 3 cm above the pulmonary valvular cusps. In addition, a saccular aneurysm 3.5 cm in diameter had formed at the right pulmonary hilus. Histopathology revealed marked medical degeneration and fragmentation of the elastic laminae in the former lesion and a true aneurysm with attenuation and fragmentation of elastic laminae in the latter. The peripheral vasculature in the lungs showed evidence of increased pulmonary arterial pressure, including plexiform and angiomatoid lesions. We present this unique case and discuss the pathomorphogenesis of these lesions in conjunction with primary pulmonary hypertension.

Castleman's disease of the abdomen and pelvis: report of three cases and a review of the literature.

Three cases of Castleman's disease (CD) of the abdomen and pelvis are reported. Tumoral lesions were located in the lymph nodes of the head of the pancreas, the gastropancreatic fold, and around the left iliac artery. Histologically, all the tumoral lesions demonstrated the hyalinevascular type of CD. This unusual presentation made CD difficult to diagnose preoperatively, since these lesions more closely resembled malignant tumors on computed tomography and angiography. We discuss the problems of diagnosing and classifying CD, together with a review of the literature.

Severe mitochondrial cardiomyopathy and extra-neuromuscular abnormalities in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episode (MELAS).

An autopsy case of mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) in a 56 yr-old woman is reported. Histopathologic abnormalities are shown widely in the heart, liver, kidney, pancreas and thyroid gland, other than the central nervous system and skeletal muscles that had been so far emphasized in the cases of MELAS. Particularly in the myocardium, focal fibrosis and a disarray of myofibrils were demonstrated, which closely resembled that seen in idiopathic hypertrophic cardiomyopathy. In addition, unique mitochondrial abnormality exhibiting a central glycogen aggregation with surrounding multiple radiating cristae was noted in some cardiomyocytes, which has never been reported in previous cases of MELAS. Thus, in MELAS, various histopathological abnormalities including the mitochondrial abnormalities may involve tissues other than those of the neuromuscular system.

Isolated pulmonary giant cell vasculitis.

An autopsy case of granulomatous vasculitis confined to the pulmonary vasculature in a 40-year-old woman with widespread ovarian carcinoma is reported. Although gross lesions were not identified in the lungs other than a few metastatic tumor nodules, vascular lesions were demonstrated microscopically throughout both lungs. Histopathologically, granulomatous vasculitis was present only in the large and medium-calibered pulmonary arteries of elastic type and in pulmonary veins. Granulomas were distributed mainly in the media and adventitia. The lumina of arteries and veins were free from any occlusion or dilatation. In the granulomas, multinucleated giant cells of both foreign body and Langhans' types containing asteroid body often appeared with slight infiltration by T-lymphocytes. Fibrinoid necrosis was absent in the granulomatous lesions, and neutrophils and eosinophils were also not present. The pulmonary granulomatous vasculitis in this case is distinctly different from the other pulmonary necrotizing and granulomatous vasculitides previously reported.

A case of basaloid-squamous carcinoma of the esophagus: immunohistochemical and ultrastructural studies.

A case of basaloid-squamous carcinoma of the esophagus in an 83 year old man is reported. The esophageal tumor showed a fungating growth at the junction of the middle and lower esophagus and was composed microscopically of submucosal multiple nests with solid and cribriform-like patterns accompanied with a small focus of squamous cell carcinoma adjacent to the overlying esophageal epithelium. The structural features closely resembled those of basaloid-squamous carcinoma. The submucosal tumor cells were immunohistochemically positive for epithelial membrane antigen, wide spectral keratin, alpha actin and S-100 protein. By electron microscopy, the tumor cells had microvilli, desmosomes and bundles of myofilaments, and replicated basement membranes were frequently observed adjacent to the nests. The positive immunoreaction of S-100 protein and alpha actin and the existence of bundles of myofilaments indicated that the present tumor did not correspond well with basaloid-squamous carcinoma. In addition, there was no evidence of true glandular lumina in the tumor nests, a finding which was inconsistent with that of adenoid cystic carcinoma. From the immunoreactivity of S-100 protein and ultrastructural features, it was considered that the present submucosal tumor had originated from undifferentiated pluripotential primitive cells, which differentiated to myoepithelial cells.

Cardiac pseudoaneurysm caused by mitral ring calcification.

A case of left ventricular pseudoaneurysm caused by mitral ring calcification (MRC) in a 71-year-old woman is reported. MRC was initially detected by two-dimensional echocardiography. Two months later, rupture of the posterior wall and pseudoaneurysm formation were diagnosed. Mitral value replacement and reconstructive surgery of the myocardial wall were performed. The patient died 46 days after the operation. At autopsy, there was no histopathological evidence of myocardial infarction, infective endocarditis, or other conditions affecting the cardiac endomyocardium. Pseudoaneurysm apparently resulted from left atrial and ventricular tears caused by MRC.

Multiple penetrating colonic ulcers in secondary amyloidosis caused by rheumatoid arthritis.

An autopsy case of multiple penetrated colonic ulcers with secondary amyloidosis caused by rheumatoid arthritis in a 61 year old woman is reported. Amyloid deposition was conspicuous in the transverse colon with numerous penetrating ulcers that were circumferentially scattered. Deposition was mainly in the small vessel walls of the submucosal layers. In the quantitative comparison of the histological components between the colonic segments affected by severe and mild ulcer formation, occlusive vascular amyloid deposition was revealed more frequently in the severe involved portion than in the mild involved portion. In addition, submucosal fibrosis that tended to appear around ulcers was more extensive and thicker in the former than in the latter. The complete vascular occlusion caused by amyloid deposition was particularly concentrated in the submucosal layer adjacent to the ulcer. These findings indicate that peripheral circulatory disturbance by amyloid deposition in the small vascular walls leads to ulcer formation in the colon.