Injury and repair of smaller muscular and elastic arteries

Summary Indirect immunoperoxidase staining for fibrinogen/fibrin and fibronectin was performed on normal and healing arterial tissue of muscular and smaller elastic arteries. Fibronectin was observed in the wall of the normal arteries, whereas fibrinogen/fibrin could not be demonstrated. Fibronectin was observed in the intima as well as the media deposited in a similar fashion in the femoral and carotid artery during repair. Apart from the early occurrence of fibrin/fibrinogen in the media of both arteries the distribution of fibrinogen/ fibrin and degradation products differed. In the femoral artery a progressively weakening positive reaction for fibrinogen/fibrin and degradation products towards the lumen was observed in the intima and the media 7 and 14 days after the lesion. By 28 days the reaction in the media was negative. No thrombus formation was observed. In contrast, all the specimens examined from the common carotid arteries were obliterated by luminal thrombi 28 days after the lesion. The thrombus as well as the damaged intimal thickening and the compressed media were loaded with fibrinogen/fibrin and degradation products. The deposition of fibronectin, fibrinogen, and degradation products in the carotid artery was similar to that previously reported in experimental aortic arteriosclerosis in rabbits as well as in giant cell arteritis.     

Injury and repair of smaller muscular and elastic arteries

Summary 26 rabbits of the Danish country strain were subjected to mechanical dilatation injury of the left femoral and carotid arteries with Fogarty's embolectomy catheters F2 and F3 respectively. The rabbits were killed 2, 7, 14 and 28 days after the dilatation injury and the arteries examined histologically. Initially both of the arteries exhibited necrosis of the media and infiltration of the vessel wall with neutrophils and mononuclear cells. From day 7, intimal thickening was observed in both types of arteries, progressing in thickness during the later stages. However, thrombosis occurred in the majority of the carotid arteries, whereas this was only infrequently seen in the femoral arteries. In all of the dilated arteries, the elastic laminas were stretched or fragmented and never regained their normal appearance. In the carotid artery, giant cells accumulated around the fragmented elastin and calcified areas, located primarily at the intima-medial border. These changes were never observed in the femoral artery. At the twenty-eight days stage, proliferation of the smooth muscle cells more or less led to restitution of the media in the femoral artery, whereas the carotid artery showed medial restitution only to a lesser extent. The similarities between the injured carotid artery and human temporal arteritis, and the utility of the model as an animal model for the study of temporal arteritis are underlined.     

The function of elastic fibers in the arteries: Beyond elasticity

The main components of elastic fibers, elastin and fibrillin-containing microfibrils play a structural and mechanical role in the arteries and their essential function is to provide elasticity and resilience to the tissues. However, through control of the quiescent contractile phenotype of arterial smooth muscle cells, elastin also acts as an autocrine factor and, via the binding of ‘latent transforming growth factor (TGF)-β binding protein (LTBP) – latency-associated peptide (LAP) – TGF-β’ complexes, fibrillins regulate the activation and availability of TGF-βs. These recent discoveries are detailed in this review.     

A primer of endometrial cytology with histological correlation

Cytology is an effective method for assessing benign endometrium and for discovering premalignant and malignant endometrial states. In addition, it is useful for diagnosing non-neoplastic abnormalities of the endometrium. This overview compares endometrial cytology to endometrial histology for a variety of benign, abnormal non-neoplastic, and neoplastic conditions; and, discusses both diagnostic criteria and pitfalls in the assessment of endometrial brushings specimens. It also makes an attempt to estimate levels of confidence in endometrial cytodiagnosis. When endometrial brushing is used in conjunction with other diagnostic techniques such as ultrasonography/sonohysterography or hysteroscopy, cytology becomes a sensitive case finding technique that shows good patient acceptance (because of a significant decrease in procedure-associated pain) and high diagnostic yield.     

Magnetic resonance microscopy of hamster olfactory bulb: A histological correlation

Background: Magnetic Resonance Imaging (MRI) has been widely used as a noninvasive diagnostic tool for obtaining morphological, metabolic, and functional information from tissue. However, its potential application in observing detailed structure comparable to that of the light microscope has not yet been fully explored. In order to evaluate the usefulness of MR microscopy, a high resolution three-dimensional (3-D) technique was applied to observe the laminar structure of the mammalian olfactory bulb (OB). Methods: Adult male hamsters (Mesocrecitus auratus) were used as an animal model. Hamster OB and the attached anterior olfactory nucleus were removed from the skull for the MRI examinations. The images were performed with a Bruker AMX-400 system equipped with microimaging accessories. T2 weighted 3-D spin echo sequence was used with a field of view of 9 mm and data matrix of 128*128*128. The in-plane resolution was 70*70*70 μm. Histological preparation, including vibratome sectioning at 40 μm and Nissl staining, were used for light microscopic evaluations and comparisons. Results: Five distinct layers from the superficial to the center of the OB were distinguished in the MR images of coronal, sagittal and horizontal slices. As compared to the histological sections at the corresponding cutting planes, the laminar structure of the OB displayed in the MR microscopic images correlated well with its counterparts. Conclusions: MR microscopy is capable of detecting cellular variation of unsectioned and unstained tissue. It can also be easily applied to obtain spatial information with good resolution. It appears to provide a great potential for diagnostic pathology. © 1995 Wiley-Liss, Inc.     

Liver lesions found at colectomy in ulcerative colitis: correlation between histological findings and biochemical parameters.

AIMS--To classify lesions discovered at colectomy in patients with ulcerative colitis; to assess the importance of histological findings by correlating them with biochemical parameters. METHODS--Liver tissue specimens taken at colectomy from 59 patients with chronic ulcerative colitis were studied using light microscopy. The findings were compared with results of biochemical liver function tests. RESULTS--Abnormal laboratory findings were found in 12 patients with liver histology consistent with primary sclerosing cholangitis. Non-specific reactive hepatitis was observed in six patients, eight had fatty liver, and three minor non-specific parenchymal changes. Twenty nine patients had normal liver histology. The highest cholestatic serum enzyme activities were seen in two patients with sclerosing cholangitis. Cholangiography in these patients also revealed changes in the extrahepatic bile ducts. However, identical histological changes were also present in patients with only slightly abnormal or even normal liver enzyme activities. CONCLUSION--Biochemical tests of liver function do not reliably indicate the extent or severity of bile duct damage in ulcerative colitis, the assessment of which requires liver biopsy.     

A rare case of plexiform fibromyxoma in stomach: FNA diagnosis with histological correlation and differential diagnoses

Plexiform angiomyxoma (PF) is a rare benign mesenchymal neoplasm that arises in the antrum and pyloric region of the stomach. To the best of our knowledge, there are only two prior endoscopic ultrasound guided fine needle aspiration cytology examples have been reported. We report a case of PF which was diagnosed via EUS FNA and later confirmed on resection specimen. Differential diagnoses of this tumor are discussed. Although diagnosis of plexiform fibromyxoma on FNA specimen is difficult, a good FNA specimen with subsequent careful morphological evaluation and immunohistochemical staining work-up makes this task possible.     

Expression of metallothionein in lung carcinoma: correlation with histological type and grade

AIMS: Over-expression of cellular metallothionein occurs frequently in human tumours but the underlying mechanism remains unknown. The aim of this study was to assess metallothionein expression in cases of lung carcinoma and to correlate it with histopathological parameters. METHODS AND RESULTS: Tumour tissue samples from 89 patients with lung carcinoma were immunostained by the streptavidin-biotin-peroxidase technique, using a monoclonal antibody against both metallothionein-1 and -2 isoforms. Positive matallothionein immunostaining was prominent in 44 out of 89 (49%) and negative in 45 out of 89 (51%) cases of lung carcinoma examined. Metallothionein positivity was prominent in 32 out of 43 (74%) cases of squamous cell lung carcinoma, and in 12 out of 35 (34%) cases of adenocarcinoma, while it was negative in all 11 cases of small-cell lung carcinoma examined, presenting a statistically significant difference between the different histological types. The intensity of metallothionein staining revealed a statistically significant difference between the squamous cell and adenocarcinoma cases examined. The pattern and extent of metallothionein staining in tumour cells and the expression of metallothionein in stromal cells were not correlated with histopathological parameters (type and grade) in metallothionein-positive cases of lung carcinoma examined. No association was found between metallothionein expression and lymph node status in the examined cases of lung carcinoma. CONCLUSIONS: Our findings indicate that expression of metallothionein was evident in squamous cell lung carcinoma and adenocarcinoma, but absent in small-cell lung carcinoma, supporting evidence for participation of this protein in the biological mechanisms underlying the carcinogenic evolution in the lung.     

Nondestructive quantification of leakage at the tooth–composite interface and its correlation with material performance parameters

Current methods to determine debonding/leakage at the tooth–composite interface are qualitative or semi-quantitative. Our previous work introduced a 3D imaging technique to determine and visualize leakage and its distribution at the interface of cavity wall and composite restoration in model cavities. In this study, an automated program was developed to quantify leakage in terms of area and volume. 3D leakage distribution obtained via the image analysis program was shown to have excellent agreement with leakage visualized by dye penetration. The relationship between leakage and various material performance parameters including processability, shrinkage, stress, and shrinkage strain-rate was determined using a series of experimental composites containing different filler contents. Results indicate that the magnitude of leakage correlated well with polymerization stress, confirming the validity of the common approach utilizing polymerization stress to predict bonding durability. 3D imaging and image analysis provide insight to help understand the relations between leakage and material properties.     

Human lung tumours: a correlation of antigenic profile with histological type

Fifty-four human lung tumours have been immunostained with a large panel of monoclonal antibodies including reagents against cytokeratins, prekeratins, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA) and neural antigens. These results have been compared with the histological types of tumour using the current WHO classification scheme. The most striking finding of this study was the considerable overlap of antigenic profile between different histological types of tumour. This suggests that there may be a greater underlying similarity between different histological categories of lung tumour than has hitherto been assumed. Secondly it was evident that immunostaining highlighted areas of different morphology within many tumours emphasizing the heterogeneous differentiation patterns seen in lung cancers. The present study supports the viewpoint that lung tumours arise from a common stem cell and that these neoplasms represent a single tumour with a tendency to differentiate along one or more pathways.     

Immunohistochemical metallothionein expression in thymoma: correlation with histological types and cellular origin

Metallothioneins (MTs) are low molecular weight and cysteine-rich intracellular proteins involved in metal homeostasis and detoxication. They are found in certain normal tissues, and are overexpressed in various tumours with correlation to more aggressive behaviour in certain tumours. Since the histopathological types of thymoma have unpredictable invasive potential, MT over-expression was investigated as a possible marker of the invasive potential of thymomas. We studied immunohistochemical MT expression in 27 non-invasive thymomas, 20 micro-invasive thymomas, and 23 macro-invasive thymomas with a mouse monoclonal anti-MT antibody E9 on formalin-fixed paraffin-embedded tissues. MT expression was significantly different among the three groups of thymomas ( P  = 0.02) with a stronger expression in invasive thymomas ( P  = 0.003). However, MT expression was not exclusively limited to invasive thymomas. Therefore, it could not be used as a marker of aggressive potential in individual thymomas. Analysis of MT expression according to the histological types of the thymomas revealed that eight of nine spindle cell thymomas, none of 10 small polygonal cell thymomas, four of 14 mixed thymomas, seven of 29 large polygonal cell thymomas, and seven of eight squamoid thymomas significantly expressed MT. There was a statistically significant difference in MT expression among different histological types of thymomas ( P  = 0.000). The strongest and most consistent expression was observed in spindle cell thymoma and squamoid thymoma. Since spindle cell thymoma was usually non-invasive and squamoid thymoma was more aggressive, MT expression does not correlate with the invasive potential of different histological types of thymomas. But because medullary epithelial cells of the thymus were positive for MT, our results suggest that both spindle cell thymoma and squamoid thymoma might derive from the medullary compartment of the thymus.     

A histological, ultrastructural and immunohistochemical study of superficial temporal arteries and middle meningeal arteries in moyamoya disease.

Pathologic changes in superficial temporal arteries (STA) and middle meningeal arteries (MMA) biopsied from 15 patients with moyamoya disease (MD) who had undergone cerebro-temporal arterio-synangiosis were studied histologically, ultrastructurally and immunohistochemically. The main pathologic features were: proliferation of smooth muscle cells (SMCs) and thickening of the intima, degeneration and destruction of SMCs in the media and intima, and the presence of condensed organelles in necrosed SMCs or the interstitium among SMCs, or both outside and within the elastica interna (EI). The EI had become thin, porous, fragmented and was even absent in some segments. These changes are different from those of other forms of angiopathy, but identical with those at the ends of internal carotid arteries (ICA) reported by us previously, being pathognomonic for MD. These changes in the STA and MMA reveal that MD involves not only the ICA but also the intra- and extracranial branches of external carotid arteries. The medial necrosis of SMCs seems to be the primary injury of the arterial wall in MD. STA tissue blocks from two cases of MD were stained immunohistochemically. By electron microscopy, IgG-, IgM-, and C3-positive granules were observed on the ER of endothelial and intimal cells. Further studies on more cases are needed to determine whether an immunoreaction has occurred in these arteries.     

Becker muscular dystrophy: correlation of deletion type with clinical severity.

Molecular deletion screening with cDNA probes from the dystrophin gene was undertaken in patients with Becker muscular dystrophy from 58 separate families. Deletions were found in 41 (71%) of these families. Thirty-four (83%) of the deletions started in the same intron near the centre of the gene, and although there was no precise correlation between clinical severity and deletion pattern, the commonest deletion pattern, which was present in 49% of all deletion families, is associated with a mild phenotype.