Biomedical subjects

L Vercruysse

Publications and source records attributed to L Vercruysse.

25 records · Page 2Linked to original sources

PubMed1995

Identification of 'renin'-containing cells in the choriodecidua.

Chorionic trophoblast, decidual cells, and macrophages have all been named as the site of renin in the placental membranes. To establish more clearly the nature of the renin-containing cells in the placental membranes, double immunostaining techniques were used to stain renin and specific cell markers in the same tissue sections. Cytokeratin was selected as an ectodermal cell marker and CD68 as a cytoplasmic macrophage marker. Cross-binding between antibodies was prevented by blocking species-related binding sites between the first and second sequence of the double-immunostaining procedures and by using highly selective immunostaining techniques in the second sequence. The results clearly show renin immunostaining in CD68-positive macrophages and not in cytokeratin-positive trophoblast. The anti-renal renin monoclonal antibody showed high affinity cross-reactivity with cathepsin D, another aspartic proteinase that can release angiotensin I from angiotensinogen. This should be seen in the context of earlier findings that only two of four anti-renal renin monoclonal antibodies showed staining in uterine and placental tissues and both cross-reacted with cathepsin D. The results indicate that differentiation between renin and cathepsin D and, possibly, other substances with shared properties and epitope homology deserves more attention than it has received thus far.

Chorion↗

PubMed1994

The endocrine pancreas in nonimmune hydrops fetalis.

OBJECTIVE: Our purpose was to compare the endocrine pancreas of hydropic infants of immune and nonimmune origin. STUDY DESIGN: A quantitative morphologic study was performed on the pancreas in 10 infants with immune and nonimmune hydrops. The volume density of the endocrine pancreas in the gland was calculated, as was the numerical density of the endocrine cells in the islets. The percentage of the different cell types was measured on immunohistochemical stained slides. Ten normal infants were used as controls. RESULTS: An increased amount of endocrine tissue and an increased total number of islet cells of immune and nonimmune origin is present in hydropic infants. However, an increased proportion of the insulin-producing B cells is not present. CONCLUSIONS: The endocrine pancreas in hydrops fetalis of immune and nonimmune origin is equal, excluding hemolysis as the stimulating factor for equilibrated islet overgrowth. Metabolic stimuli, as seen in infants of diabetic mothers, are probably not involved, because they preferentially stimulate the insulin-producing B cells.

Case-Control Studies↗

PubMed1993

Tibial shaft fractures with an intact fibula.

The effect of several factors on the healing rates of tibial shaft fractures with an intact fibula were examined. Those found to adversely affect healing rates included: 1. Open fractures; 2. Oblique or comminuted fractures; 3. High-velocity injuries; 4. Angulation in the sagittal plane; 5. Displacement. No other factors examined were associated with delayed union. The predictive values for delayed union are estimated for each of these factors in isolation and in combination.

Adolescent↗

PubMed1992

The intact fibula.

The notes and radiographs of 281 adult tibial shaft fractures were reviewed. In 17 per cent there was an intact fibula. Delayed union rates were lower when the fibula remained intact, thus confirming that this is a good prognostic indicator. This fracture is caused by less severe trauma than fractures where both bones are broken. It is rare over the age of 30 years.

Adolescent↗

PubMed1991

Placental bed spiral arteries in the hypertensive disorders of pregnancy.

OBJECTIVE: The investigation of the histology of the placental bed spiral arteries in normal pregnancy and in pregnancies complicated by hypertension, with or without proteinura. DESIGN: An observational study, based on women having caesarean sections for clinical reasons. SUBJECTS: 17 normal pregnant women, 43 with gestational hypertension, of whom 39 had proteinuria, 17 with chronic hypertension, of whom 6 had proteinuria, and 5 with unclassified hypertension. INTERVENTIONS: Placental bed biopsies obtained during caesarean section. MAIN OUTCOME MEASURES: Histological appearance of sections stained with haematoxylin and eosin PAS and Lendrum's MSB. RESULTS: Biopsies containing spiral arteries were obtained from 6 normotensive and 44 hypertensive women. Trophoblastic invasion was present in 5 of the 6 normotensive biopsies but absent in the majority of those with hypertension. Subintimal proliferation was seen in all the normotensive biopsies but in only 8 of 28 from those with gestational hypertension and proteinuria. Other features seen predominantly or only in the hypertensive biopsies, in order of frequency, were medial hyperplasia, fibrin deposits, acute atherosis, endothelial vacuolation and thrombosis. CONCLUSION: Absence of physiological changes may not be peculiar to preeclampsia but may be associated or even a result of various forms of hypertension in pregnancy. Spiral arteries show a spectrum of changes in hypertensive pregnancies that do not appear to bear a clear-cut relation to the clinical signs.

Arteries↗

PubMedDate not supplied

Thomas Huxley and the rat placenta in the early debates on evolution.

The 19th century debates on mammalian classification in the light of the new evolutionary thinking led to controversies between Thomas Huxley and Richard Owen concerning the value of the placenta as a representative key organ. As a main point in his argument, Huxley provided a detailed description of a sectioned rat placenta, highlighting the importance of decidualization of the uterus as an argument supporting an evolutionary relationship between rodents, insectivores and primates, an idea hotly contested by Owen. In addition, he illustrated and correctly interpreted the maternal blood supply from uterus to placenta in striking detail. During the succeeding decades the key role of trophoblast in placenta formation was discovered, and the decidua became neglected in later comparative studies. Nevertheless, at the present time trophoblast-decidual interaction is regarded as an extremely important feature of placental development in both primates and rodents, and Huxley can therefore rightfully be considered as an early pioneer in placental research.

Anatomy↗

PubMedDate not supplied

Mathias Duval on placental development in mice and rats.

Mathias Duval (1844-1907) was one of the pioneers in elucidating the intricate placental histology of different mammalian groups, notably the rodents. Using a well-dated series of mouse conceptuses, he described in detail the successive steps in placental development, and for confirmation he included observations on a (undated) collection of rat specimens. Not only was he able to identify correctly the different extra-embryonic cell layers, but he was also the first to recognize trophoblast invasion in rodents. Not all his interpretations are still valid, however. Re-reading his extensive and detailed work "Le placenta des rongeurs" (1890-1892) confronts us with still existing gaps in our present understanding of placental development, notably the morphogenesis of the different placental layers and the differentiation of invasive trophoblast. His understanding of uteroplacental blood flow was still limited, and he failed to recognize the complexity of the maternal decidua and its vasculature, which is essential for correctly understanding the pathways and extent of trophoblast invasion. Although Duval was active in promoting Darwin's evolutionary ideas, he refrained from extrapolating too quickly his findings in rodents to other mammalian groups including humans. In his view detailed histological studies on complete series of specimens had to come first, and thus provide a firm basis for a proper understanding of placental function and evolution.

Animals↗