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F Smedts

Publications and source records attributed to F Smedts.

At least 55 records · Page 3Linked to original sources
PubMed1993

The usefulness of the lactate dehydrogenase macroreaction in autopsy practice.

The detection of recent myocardial damage by means of the macroscopic lactate dehydrogenase reaction (LDHr) linked to nicotinamide adenine dinucleotide diaphorase (NADHd), conducted in a liquid medium is greatly insensitive to postmortal autolysis. In 10 heart cones (i.e., cardiac ventricles severed underneath the coronary sulcus) stored at 6 degrees C for up to 114 h after death, no autolytic artifacts appeared on freshly cut apical surfaces of transverse myocardial slices. In 10 cones kept at room temperature for up to 95 h after death, no artifacts appeared in eight cases; in two cases the LDHr was impaired by postmortal bacterial spread and decomposition of the myocardium. Intravital perfusion of injured myocardium increases the sensitivity of the LDHr. Postmortal stand-still of circulation is decisive in preserving dehydrogenase activities in undamaged myocardium. An artificial decrease in enzyme activity always appeared on the nonrecent, basally facing cut surfaces of slices exposed to air and fluid oozing out of the myocardium for long periods, even if the exposed surface of the cone was kept at 6 degrees C and wrapped in plastic. In normal practice, when bodies are stored in a refrigerating unit, the LDHr may still indicate myocardial damage more than 114 h after death.

Adolescent↗
PubMed1992

Retrogastric versus antegastric routing and histology of the right gastroepiploic artery.

To maximize use of the right gastroepiploic artery in myocardial revascularization 11 cadavers were studied to determine the shortest route (retrogastric versus antegastric) of the right gastroepiploic artery from its origin to the recipient coronary artery. Any coronary artery could be reached with an in situ right gastroepiploic artery. There was no significant difference between the retrogastric and antegastric routes for any coronary artery, although the former generally is slightly shorter to the vessels on the posterior surface of the heart and the latter to vessels on the anterior surface of the heart. Histological examination of the right gastroepiploic artery in its proximal, mid, and distal segments showed a similar width of intima and media and invariably an almost purely muscular media. Based on the histological similarity of the right gastroepiploic artery to the coronary artery, some scepticism toward liberal use of the right gastroepiploic artery, especially if used as a free graft, is warranted until clinical studies on its long-term patency have been performed.

Aged↗
PubMed1992

Adeno-carcinoid or amphicrine tumors of the middle ear a new entity?

The clinicopathological, ultrastructural and immunohistochemical characteristics of four primary tumors of the middle ear are reported. These neoplasms showed a striking, heterogeneous aspect ranging from solid-trabecular (Type I) to tubulo-glandular (Type II) growth patterns. Secretory activity of the tumor cells was evaluated by immunohistochemistry and electron microscopy. Based on these procedures, three cell types were found, mainly limited to tumors with a tubulo-glandular (Type II) growth pattern. Most frequent were B-cells with an abundant pale cytoplasm containing neuroendocrine granules, both cytokeratin and vimentin as well as several endocrine marker substances. Less frequent were A-cells, which are slender, darkly staining and line the glandular lumina. They showed exocrine activity only and stained strongly with a polyclonal cytokeratin antibody. Finally, least frequent were amphicrine cells, which were characterized by both lumina and neuroendocrine granules in their cytoplasm and were interpreted as the link between A and B cells. Although this morphological description closely resembles that of carcinoids and adenocarcinoids of the respiratory tract and gut, the clinical behaviour of these middle ear tumors nevertheless seems different, with no recurrence or metastasis after a follow-up of 1 to 14 years (median 78 months). Therefore, some authors suggest that these tumors should be classified as middle ear adenomas or adenomatous tumors. However, we strongly feel that these tumours represent a distinct entity and can be classified as adenocarcinoids or amphicrine tumors, i.e. demonstrating both exocrine and endocrine activities. Further work is required to evaluate the exact proportion of neuroendocrine and amphicrine tumors in the heterogeneous group of adenomas and in the rarely described group of adenocarcinomas.

Adult↗
PubMed1992

Basal-cell keratins in cervical reserve cells and a comparison to their expression in cervical intraepithelial neoplasia.

Expression of keratins 5, 14 and 17 in endocervical subcolumnar reserve cells was detected by means of immunohistochemical studies using polypeptide specific monoclonal antibodies. These particular keratins that were found among others in basal cells could also be detected to a variable extent in metaplastic and dysplastic cervical lesions. In some cases of immature squamous metaplasia all three keratin subtypes were expressed throughout the full thickness of the epithelium. In contrast, in mature squamous metaplasia a compartmentalization of these keratins was observed. Mature squamous metaplastic epithelium showed a keratin distribution pattern comparable to ectocervical squamous epithelium, with the exception of keratin 17, which was only sporadically found in the basal layer of ectocervical epithelium and was always present in the basal cells of mature squamous metaplastic epithelium. During progression of cervical intraepithelial neoplasia a clear increase in the expression of keratin 17 was observed. However, also keratins 5 and 14 were expressed. Our results demonstrate that a considerable number of premalignant lesions of the uterine cervix express the same keratins as found in the progenitor reserve cells. Lesions that lack expression of keratin 17 may form a distinct group, which are regressive in nature and do not progress into cervical cancer.

Cervix Uteri↗
PubMed1992

Keratin expression in cervical cancer.

Using a panel of 21 monoclonal and 2 polyclonal keratin antibodies, capable of detecting separately 11 subtypes of their epithelial intermediate filament proteins at the single cell level, we investigated keratin expression in 16 squamous cell carcinomas, 9 adenocarcinomas, and 3 adenosquamous carcinomas of the human uterine cervix. The keratin phenotype of the keratinizing squamous cell carcinoma was found to be most complex comprising keratins 4, 5, 6, 8, 13, 14, 16, 17, 18, 19, and usually keratin 10. The nonkeratinizing variety of the squamous cell carcinoma expressed keratins 6, 14, 17, and 19 in all cases, usually 4, 5, 7, 8, and 18, and sometimes keratins 10, 13, and 16. Adenocarcinomas displayed a less complex keratin expression pattern comprising keratins 7, 8, 17, 18, and 19, while keratin 14 was often present and keratins 4, 5, 10 and 13 were sporadically found in individual cells in a few cases. These keratin phenotypes may be useful in differential diagnostic considerations when distinguishing between keratinizing and nonkeratinizing carcinomas (using keratin 10, 13, and 16 antibodies), and also in the distinction between nonkeratinizing carcinomas and poorly differentiated adenocarcinomas, which do not express keratins 5 and 6. Keratin 17 may also be useful in distinguishing carcinomas of the cervix from those of the colon and also from mesotheliomas. Furthermore the presence of keratin 17 in a CIN I, II, or III lesion may indicate progressive potential while its absence could be indicative of a regressive behavior. Because most carcinomas express keratins 8, 14, 17, 18, and 19, we propose that this expression pattern reflects the origin of cervical cancer from a common progenitor cell, i.e., the endocervical reserve cell that has been shown to express keratins 5, 8, 14, 17, 18, and 19.

Adenocarcinoma↗
PubMed1991

Fulminant neonatal sepsis due to Haemophilus influenzae.

A case of fulminant neonatal Haemophilus influenzae sepsis is presented. A 29-year-old woman presented at 34 weeks gestation with premature labor but with intact membranes. The male infant died 8 h after delivery due to respiratory insufficiency. Ante-mortem blood cultures and post-mortem blood and lung cultures yielded H. influenzae (biotype II) which could not be serotyped. H. influenzae was cultured from the mother's cervix 5 days after delivery. This strain was of the same biotype and also nonserotypable. Serum obtained from the mother exhibited reduced bactericidal activity against the isolates. We suggest the use of selective media in routine cervix cultures from pregnant women to detect H. influenzae, which might be responsible for neonatal septicemia.

Adult↗
PubMed1990

Cytokeratin expression in chondroblastomas.

The present study is based on the histopathological and immunohistochemical examination of seven chondroblastomas, including one lung metastasis occurring 9 years after treatment. Chondroblastomas were shown to co-express vimentin, S-100 protein, neuron-specific enolase, and the epithelial markers recognized by CAM 5.2, EMA and a polyclonal cytokeratin antibody. The cytokeratins present in the tumour cells of the lung metastasis were characterized as cytokeratins 8, 18, 19 and, to a lesser extent, cytokeratin 7. The results suggest aberrant cytokeratin expression in chrondroblastomas.

Adolescent↗
PubMed1990

Changing patterns of keratin expression during progression of cervical intraepithelial neoplasia.

The expression of keratins in normal cervical epithelia, metaplastic epithelium, and cervical intraepithelial neoplasia (CIN) grades I, II, and III is investigated with a panel of keratin polypeptide-specific monoclonal antibodies. This approach allowed the detection of individual keratins 4, 7, 8, 10, 13, 14, 18, and 19 at the single-cell level. By using an antibody recognizing keratins 5 and 8 (RCK 102) and two antibodies specific for keratin 8 (CAM 5.2 and M 20), it was also possible to derive information on the distribution of keratin 5. Our results show that during immature squamous metaplasia there is an acquisition of keratins typical of squamous epithelium, ie, keratins 4, 5, 13, and 14. This process continues during further differentiation to mature squamous metaplasia. In premalignant lesions the expression pattern of the progenitor reserve cells and immature squamous metaplastic epithelium is partly conserved. However, in most cases an induction in the expression of the keratins 4, 13, and 14 was observed. Furthermore, CIN III shows a more extensive expression of keratins typical of simple epithelia, ie, keratins 8 and 18, as compared to CIN I and CIN II.

Adult↗
PubMed1990

Comparative anatomic studies of various arterial conduits for myocardial revascularization.

Comparison was made between the morphologic condition of the left anterior descending artery and four arterial conduits: the internal mammary, right gastroepiploic, inferior epigastric, and radial arteries, harvested from 17 patients (aged 15 to 85 years, mean 64 years) who had died of nonvascular diseases. Proximal, mid, and distal segments were examined microscopically. The internal mammary artery was elastic, but the others were muscular. In all four conduits, atherosclerosis was absent to mild, the internal elastic lamina showed only minimal defects, and the vasa vasorum were confined to the adventitia. In all cases the left anterior descending artery showed mild to severe atherosclerosis and substantial defects in the internal elastic lamina with penetration of the vasa vasorum into the media and intima. Comparison of the mean distance (+/- standard deviation) from the lumen to the outermost portion of the media for the left anterior descending artery (320 +/- 63 microns) with the four conduits gave comparable values for the internal mammary artery (350 +/- 92 microns); p = not significant) and the right gastroepiploic artery (291 +/- 109 microns; p = not significant), versus 529 +/- 52 microns; p less than 0.002) for the radial artery and 249 microns (+/- 87 microns) (p less than 0.04) for the inferior epigastric artery (Kruskal-Wallis and Mann-Whitney U tests). The relatively scanty presence of smooth muscle cells in the thin-walled media of the internal mammary artery combined with a well-formed internal elastic lamina, even at advanced age, may be an important cause for its low susceptibility to atherosclerosis and a major determinant in its superior long-term patency as a coronary artery bypass graft. This finding emphasizes the justification of continued use of the ideally matching internal mammary artery, either as in situ or free graft, in coronary artery bypass grafting. In contrast to the thick-walled radial artery, which may be relatively prone to ischemia, an acceptable long-term patency of the inferior epigastric artery and right gastroepiploic artery, if harvested as pedicled grafts, is anticipated.

Adolescent↗