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F Smedts

Publications and source records attributed to F Smedts.

At least 37 records · Page 2Linked to original sources
PubMed1996

BCL-2 immunoreactivity increases with severity of CIN: a study of normal cervical epithelia, CIN, and cervical carcinoma.

The presence of the BCL-2 protein, a marker for inhibition of programmed cell death, was studied in a series of routinely processed cervical tissues, consisting of normal endocervical (n = 40) and ectocervical epithelium (n = 27), squamous metaplastic epithelium (n = 30), CIN (cervical intraepithelial neoplasia) lesions (n = 32), and cervical carcinomas (n = 13). BCL-2 was strongly expressed in the basal cell compartment of normal ectocervical squamous epithelium and in nearly all reserve cells, while in endocervical columnar cells it was moderately expressed. In immature squamous metaplastic epithelium, BCL-2 expression varied. Half of the cases showed only basal cell staining, while the other half showed staining also in suprabasal layers. BCL-2 could be detected in all premalignant lesions, showing a striking increase in the number of positive cells with increasing severity of CIN, in combination with a mild increase in staining intensity. All adenocarcinomas were positive (n = 5), while five of eight squamous cell carcinomas expressed BCL-2. Based on these results, it is hypothesized that both the larger number of cells staining with BCL-2 in higher grades of CIN and the increase in staining intensity imply an increasing protection of these neoplastic conditions against programmed cell death. This protection facilitates not only continuing proliferation, but also the induction of genetic instability in dysplastic epithelial cells; it may thus reflect the greater capacity of the more severe CIN lesions to evolve into cervical carcinoma.

Adenocarcinoma↗
PubMed1996

Immunoperoxidase staining for identification of Aspergillus species in routinely processed tissue sections.

AIMS: To evaluate the performance of an immunoperoxidase stain using the monoclonal antibody EB-A1 to detect Aspergillus species in formalin fixed, paraffin wax embedded tissue. METHODS: The monoclonal antibody EB-A1 directed against galactomannan was used to detect Aspergillus species in 23 patients with suspected or confirmed invasive aspergillosis. Immunostaining was performed on formalin fixed, paraffin wax embedded tissue using the streptavidin-biotin method and compared with conventional haematoxylin and eosin, periodic acid-Schiff, and Gomori-Grocott stains. Results of immunostaining were semiquantitatively analysed with regard to both intensity of staining and number of positively staining micro-organisms. Tissue sections from 16 patients with confirmed invasive mycoses due to Candida species, Apophysomyces elegans, Rhizopus oryzae, Pseudallescheria boydii and Histoplasma capsulatum were used as controls. RESULTS: In 19 (83%) of 23 cases invasive aspergillosis was confirmed by both histological examination and culture (18 Aspergillus fumigatus and one A flavus). Immunoperoxidase stains were positive in 17 (89%) of 19 cases including one case of disseminated infection due to A flavus. Furthermore, the immunoperoxidase stain was positive in a culture negative tissue section with histological evidence of mycelial development, indicating the presence of Aspergillus species. Some cross-reactivity was observed with the highly related fungus P boydii, although the number of mycelial elements that stained was low. CONCLUSIONS: Immunoperoxidase staining using the monoclonal antibody EB-A1 performs well on routinely processed tissue sections and permits detection and generic identification of Aspergillus species, although it was no better than conventional histopathology in identifying the presence of an infection. An additional advantage is that the immunostain may help to provide an aetiological diagnosis when cultures remain negative.

Adolescent↗
PubMed1995

Keratins 7 and 20 as diagnostic markers of carcinomas metastatic to the ovary.

The most common carcinomas metastatic to the ovary that mimic ovarian primaries are colonic adenocarcinomas and endometrial carcinomas. Conventional histochemical staining procedures, even in combination with additional immunohistochemical assays, are of limited value in distinguishing between these metastases and primary ovarian carcinomas. In this study we investigated whether the application of monoclonal antibodies against keratins 7, 8, and 20 could help in differentiating between these categories. The reactivity patterns of 40 carcinomas metastatic to the ovary were compared with those of their primary carcinomas on the one hand and with various primary ovarian carcinomas and mesotheliomas on the other. Colon cancer metastatic to the ovary was keratin 7 negative and keratin 20 positive in 94% of the cases; in contrast, all primary ovarian carcinomas were keratin 7 positive and keratin 20 negative, with the exception of two cases of mucinous cystadenocarcinoma. Ovarian metastases of gastric cancer usually contained keratins 7 and 20. Metastases of endometrial cancer to the ovary and primary ovarian carcinomas usually showed similar keratin expression. We propose that keratin 7 and 20 antibodies may be of help to distinguish between primary ovarian carcinomas and carcinoma metastases in the ovary.

Adenocarcinoma↗
PubMed1995

Unexpected borderline malignant and malignant smooth muscle cell tumors of the uterine corpus in women treated with LH-RH analogues.

In this report, two cases of uterine smooth muscle cell tumors, one of uncertain malignant potential and one clearly malignant, are described in women treated for prolonged periods with luteinizing hormone-releasing hormone (LH-RH) analogues. Due to lengthy monitoring of LH-RH therapy, surgical intervention and histologic classification of these tumors was late in the course of disease, resulting in a delay in definite treatment. The risk to these women is discussed. The effects of LH-RH analogue therapy on fibroids is reviewed. Suggestions are put forward for monitoring LH-RH analogue therapy.

Adult↗
PubMed1995

Obstructive colitis: an analysis of 50 cases and a review of the literature.

Obstructive colitis is an ulcero-inflammatory and necrotizing condition that occurs in the colon proximal to benign or malignant stenosing lesions. it is the result of ischemia due to impairment of blood supply secondary to elevation of the endoluminal pressure, distension of the colonic wall and other factors which impair adequate perfusion. The incidence among patients with colonic obstruction is reported at between 1 and 7%. Of 50 patients with this condition in this series, 30 female and 20 male, 2/3rds were well over 70 yrs of age. Obstruction was most common in the rectosigmoid. In half the patients this was due to adenocarcinoma, 24 were due to benign obstruction and 15 were caused by diverticular disease. Type, extent and depth of ischemic lesions were highly variable and comprised early mucosal hemorrhage and edema, ulcero-hemorrhagic lesions and transmural necrosis. There was always an abrupt transition between affected and normal bowel. A segment of preserved mucosa was usually present on the proximal side of the stenosis. In 16 patients massive dilatation with stretching and thinning of the bowel wall, associated with a blow-out type of perforation or with transmural necrosis, was observed and was considered to have resulted from a rapid rise of endoluminal pressure to high levels. The microscopic and macroscopic features are described in detail and histological factors discussed in relation to the pathological lesions encountered. Emphasis is placed upon the range of appearances and similarities are shared with other inflammatory colonic diseases, particularly idiopathic inflammatory bowel disease. The importance of recognition of this disease entity, not only by pathologists but by surgeons dealing with the disease at operation, is stressed.

Aged↗
PubMed1995

p53 and human papilloma virus type 16 in cervical intraepithelial neoplasia and carcinoma.

A series of cervical biopsies and excision specimens representing normal cervical epithelium, metaplastic epithelium, cervical intraepithelial neoplasia and cervical carcinoma were examined for the presence of p53 in relation to the human papillomavirus type 16 (HPV 16). The results show that p53 accumulation in premalignant cervical lesions is almost identical to the low levels detected in normal endo- and ectocervical epithelia, reserve cells, immature and mature squamous metaplastic epithelium. p53 levels were low and seem to be independent of the grade in cervical intraepithelial neoplasia (CIN). However, carcinomas of the cervix contained high levels of immunohistochemically detectable p53. Apparently, a p53 mutation is not an early factor in cervical carcinogenesis. Furthermore, our studies demonstrate that alterations in p53 levels and the presence of HPV 16 are not mutually exclusive markers of cervical tumorigenesis. This contrasts with several reports in the literature and underlines the observation that p53 expression is probably an inadequate prognosticator for estimating progression or regression of CIN lesions.

DNA, Viral↗
PubMed1994

Detection of keratin subtypes in routinely processed cervical tissue: implications for tumour classification and the study of cervix cancer aetiology.

We investigated the expression of keratin subtypes 7, 8, 10, 13, 14, 17, 18 and 19 in the normal cervix, in cervical intraepithelial neoplasia (CIN) lesions and in cervical carcinomas, using a selected panel of monoclonal keratin antibodies, reactive with routinely processed, formalin fixed paraffin embedded tissue fragments. The reaction patterns derived for each keratin antibody were compared with known expression patterns of the various epithelia, previously examined in frozen tissues. Although the reactivity of the antibodies was generally acceptable, considerable modifications to the manufacturers' staining instructions were often necessary. For some antibodies, which were previously thought to be reactive with fresh frozen tissue only, we developed staining protocols rendering them reactive with routinely processed material. As with previous findings in frozen sections we observed increasing expression of keratins 7, 8, 17, 18 and 19 with increasing grade of CIN. In cervical carcinomas the differences in keratin detectability between the main categories were more pronounced than in frozen sections, probably due to fixation and processing. For routine pathology, keratin phenotyping of cervical lesions may be of value in classification. The fact that keratin 7 was detected for the first time in reserve cells, and that this keratin was also found to be expressed in a considerable number of CIN lesions and cervical carcinomas supports the suggestion that reserve cells are a common progenitor cell for these lesions.

Adenocarcinoma↗
PubMed1994

The applicability of a keratin 7 monoclonal antibody in routinely Papanicolaou-stained cytologic specimens for the differential diagnosis of carcinomas.

The monoclonal antibody OV-TL 12/30, which detects keratin 7, was tested for its usefulness in cytologic diagnosis by reincubating previously Papanicolaou-stained slides. For this purpose malignant effusions of 73 patients with histologically confirmed cancers of the colon, ovary, mesothelium, breast, lung, esophagus, pancreas, urinary bladder, stomach, kidney, and prostate were used. All malignant cells from ovarian adenocarcinomas were positive, whereas malignant cells from colonic adenocarcinomas and malignant mesotheliomas were negative. Adenocarcinomas of gastric, renal, pancreatic, esophageal, and mammary origin demonstrated variable staining. Transitional cell carcinomas were positive, whereas squamous and small cell lung carcinomas were negative. Because OV-TL 12/30 does not react with normal and atypical mesothelial cells in these preparations, this reagent is a valuable tool in distinguishing benign mesothelial cells and adenocarcinoma cells. The authors' results demonstrate that this antibody is an excellent tool in the differential diagnosis of malignant cells in effusions and can be used in routinely stained cytologic specimens to determine primary tumor localization. In addition to its ability to distinguish between ovarian and colonic adenocarcinomas, its negativity in mesotheliomas may prove helpful in several diagnostic considerations.

Antibodies, Monoclonal↗
PubMed1994

A 4-year-old boy with neurofibromatosis and severe renovascular hypertension due to renal arterial dysplasia.

A 4-year-old boy had severe hypertension, cardiac failure, and signs of neurofibromatosis. Arteriography disclosed renal artery stenosis in both kidneys with signs of ischemia, particularly in the right kidney. Because of insufficient response to antihypertensive therapy, a right-sided nephrectomy was performed. Histological examination of this kidney showed segmental stenosis in all branches of the renal artery. The vascular lesions were characterized by an intimal proliferation of spindle cells in a mucoid matrix with destruction of the internal elastic membrane frequently accompanied by loss or attenuation of the media and fibrosis of the adventitia. Occasionally, a nodular arrangement of the spindle cells at the interface between intima and media was observed. Immunohistochemical studies demonstrate a smooth-muscle cell origin for these cells.

Angiography↗
PubMed1993

Histological study of the internal mammary artery with emphasis on its suitability as a coronary artery bypass graft.

The internal mammary, musculophrenic, and superior epigastric arteries were unilaterally harvested from 11 individuals (aged 49 to 83 years; mean age, 67 years) and were examined histologically at 1-cm intervals. In 2 individuals the media of the entire internal mammary artery was elastic, whereas in the other 9 individuals we observed an alternating histological pattern in the media of the internal mammary artery, that of the proximal and distal segments being elastomuscular and that of the mid segment being elastic. In 4 of the latter 9 individuals the distal 10% to 20% of the media of the internal mammary artery was muscular with rare elastic lamellae. The media of the first 1 to 2 cm of the musculophrenic and superior epigastric arteries was elastomuscular or muscular with rare elastic lamellae, whereas more distally the media was purely muscular. The degree of intimal hyperplasia was significantly greater in arterial segments with a purely muscular media (25.6%) than in those with elastic (16.7%), elastomuscular (15.3%), and muscular (with rare elastic lamellae) (17.5%) types of media (p < 0.01). The mean cross-sectional luminal area of the elastic segment (1.9 mm2) and proximal and distal elastomuscular segments (1.9 and 1.2 mm2, respectively) of the internal mammary artery was significantly greater than that of the muscular segments of the musculophrenic artery (0.9 mm2) and the superior epigastric artery (0.7 mm2) (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

Intercostal artery: histomorphometric study to assess its suitability as a coronary bypass graft.

To assess potential suitability of the intercostal artery as a conduit in myocardial revascularization a histomorphometric study of the fifth intercostal artery (n = 11) and intercostal arteries other than the fifth (n = 9) was conducted. All arteries were harvested at autopsy in 11 individuals (mean age, 75 years). The length of the intercostal arteries varied from 22 to 35 cm (mean, 29.4 cm). Three combinations of histologic patterns were seen along the course of the intercostal artery: a proximal elastic segment followed by subsequent elastomuscular and muscular segments (n = 3), a proximal elastomuscular segment with the remainder of the artery being muscular (n = 6), and a completely muscular pattern (n = 2). The mean luminal diameter of the fifth intercostal arteries varied from 1.4 +/- 0.3 mm at the origin to 0.9 +/- 0.2 mm at 30 cm (30% to 40% decrease in diameter due to the flaccid state and rigor mortis). The mean intimal thickness at these locations was 54 +/- 38 microns and 25 +/- 16 microns and the mean thickness of the media was 205 +/- 38 microns and 70 +/- 45 microns. The histologic findings, mean luminal diameter, and mean diameter of the intima and the media were similar in the intercostal arteries other than the fifth. Our study demonstrates that the intercostal artery has a relatively thin intima and media, the latter being elastic or elastomuscular in the proximal segment in the majority of the investigated arteries, which are favorable properties with regard to its potential suitability as a coronary bypass conduit.

Adult↗
PubMed1993

Prevention of adhesion formation around the internal mammary artery pedicle by Gore-Tex surgical membrane. An experimental study in goats.

The effects of wrapping the internal mammary artery in Gore-Tex surgical membrane on the formation of adhesions were investigated. In seven goats both internal mammary arteries were dissected free from the thoracic wall. In six goats the internal mammary arteries were wrapped in Gore-Tex surgical membrane. In the remaining animal both arteries were removed and used as controls. After 6 months the goats were reoperated and it was found that the wrapped segments of all arteries were completely free of adhesions, whereas the non-wrapped segments showed severe adhesion formation. Histologic examination could not detect differences between the wrapped arteries and the controls. One of the 12 wrapped arteries was occluded by a longer existing thrombus, which is attributed to the surgical technique and the fact that postoperatively no anticoagulation was given. The beneficial effect of the use of Gore-Tex surgical membrane on the prevention of adhesion formation is excellent and this implies that it could be used in coronary artery bypass operations, thus reducing the chance of damage to the bypass in case of reoperation.

Animals↗
PubMed1993

Expression of keratins 1, 6, 15, 16, and 20 in normal cervical epithelium, squamous metaplasia, cervical intraepithelial neoplasia, and cervical carcinoma.

Expression of keratins 1, 6, 15, 16, and 20 was examined in normal cervical epithelia, squamous metaplasia, various grades of cervical intraepithelial neoplasia, and both squamous cell carcinomas and adenocarcinomas of the cervix with monospecific antibodies. Ectocervical epithelium contains all of these keratins except keratin 20. They show a heterogeneous distribution, with a basally restricted detection of keratin 15. Endocervical columnar cells were found to contain significant amounts of keratin 16, whereas the subcolumnar reserve cells expressed considerable amounts of keratin 15 and 16, and frequently keratin 6. These reserve cell keratins were also found in immature and mature squamous metaplastic epithelium. In the cervical intraepithelial neoplastic lesions they were generally found with increasing intensity as the severity of the lesion progressed. In the keratinizing variety of squamous cell carcinoma of the cervix, these three keratins seem to constitute an important part of the intermediate filament cytoskeleton, whereas in nonkeratinizing squamous cell carcinoma, they occur to a much lesser extent. Surprisingly, these keratins were also occasionally found in adenocarcinomas. From these data we conclude that the keratin phenotype of reserve cells and endocervical columnar cells is more complex than previously suggested. In particular, the keratins occurring in reserve cells are also present in most of the premalignant and in a considerable number of the malignant lesions of the cervix. The differentiation features of the various carcinoma types are, however, reflected in their specific keratin filament composition.

Adenocarcinoma↗
PubMed1993

The dynamics of keratin expression in malignant transformation of cervical epithelium: a review.

OBJECTIVE: To review basic and clinical aspects of cytoskeletal keratin expression in normal cervical epithelia as well as in preneoplastic and malignant epithelia of the uterine cervix. DATA SOURCES: The results of extensive studies from our group and other groups on keratin phenotyping in normal premalignant and malignant cervical epithelia were summarized. METHODS OF STUDY SELECTION: All studies involving keratin expression in the cervix were reviewed, as were general studies on keratin expression in which the cervix was mentioned and studies relevant to understanding cervical cancer etiology (36 studies). DATA EXTRACTION AND SYNTHESIS: From these studies, keratin phenotypes of the various epithelia were derived. The phenotypes were correlated to existing theories on the development of cervical carcinoma. CONCLUSIONS: It is possible to distinguish the various epithelial types in the normal cervix based on their keratin expression patterns. Reserve cells display a bidirectional keratin pattern, comprising keratins typical of both squamous and simple types of differentiation, reflecting the bipotential nature of these cells. Cervical intraepithelial neoplasia can be divided into two subpopulations, one characterized by the reserve cell keratin phenotype and the other by a keratin phenotype typical of nonkeratinizing squamous epithelia. The first population also contains the simple keratins, the relative percentage of which increases with increasing degree of dysplasia. We therefore suggest that these lesions are progressive in nature. Carcinomas show a differentiation-related keratin expression pattern in addition to the basic reserve cell keratin phenotype. Adenocarcinomas also have been shown to express most of the reserve cell keratins. The latter observation indicates a common progenitor for both carcinoma types.

Carcinoma in Situ↗