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Biomedical subjects

A Duprez

Publications and source records attributed to A Duprez.

At least 19 recordsLinked to original sources
PubMed1992

Host-donor interactions in healing of human split-thickness skin grafts onto nude mice: in situ hybridization, immunohistochemical, and histochemical studies.

The behavior of host and donor cell lines in human split-thickness skin grafts onto nude mice was studied by in situ hybridization (ISH) using genomic DNAs as probes, and immunohistochemically with species-specific or cross-species specific antibodies, at different stages ranging from day 3 to more than 1 year following grafting. Changes in the graft vascular and interstitial extracellular matrix were also assessed using species-specific or cross-species specific antibodies to human or murine type I, III, and IV collagens. Finally, transplant reinnervation was investigated using antibodies to various nerve cytoplasmic antigens and the thiocholine method to demonstrate acetylcholinesterase. Using these methods we were able to show the following: (1) the graft epidermis that is not replaced by mouse keratinocytes is progressively colonized by recipient Langerhans cells (LCs); (2) revascularization of the grafts begins soon by inoculation of the graft vessels with the host microcirculatory bed, and mouse endothelial cells growing into preexisting human capillary tubes produce a new basement membrane, prior to the replacement of the original one; (3) within 3-5 days following grafting, mouse fibroblasts migrate into the graft dermis. The density of the human and murine fibroblast populations then progressively increases. Characterization of the interstitial collagens identifies both human and murine type I and III collagens. Production of type III collagens decreases during the progression of fibrogenesis while human type I collagen becomes the predominant matrix protein; (4) transplant reinnervation is deficient, and neurites growing into severed graft nerve trunks were never detected.

Animals↗
PubMed1991

Human nerve xenografting in nude mouse: experimental study of graft revascularization.

In the nude mouse, the congenital absence of T lymphocytes makes it possible to implant human nerve grafts without rejection or iatrogenic modifications (by immunosuppression) of human and murine tissues. Medial antebrachial cutaneous nerves were harvested from human cadavers 1-18 hours after death. These nerve grafts were implanted using different techniques in nude mice. All the grafts were macroscopically and microscopically revascularized 3 days after implantation. The modifications in time of this vascularization could be studied with precision through the use of repeated biopsies. The absence of human blood group antigens on the neovessel endothelium suggested a murine origin for angiogenesis. In situ DNA hybridizations with human and mouse DNA confirmed this origin. The topography of the revascularization (maximal in the perineurium and endoneurium) and the almost complete absence of human cells other than Schwann cells in the grafts at the peak of angiogenesis (26 days after grafting) suggested that Schwann cells had a determining role in graft vascularization. The irradiation of the nerve grafts with a dose of 30 grays before implantation did not modify significantly their histologic appearance compared to the control group, whereas an irradiation of 60 grays led to massive lesions. The neurotization of murine axons led to chimerical structures of normal histologic appearance, with vascularization similar to that observed in nonneurotized nerves. Through chimerism (human Schwann cells, murine vessels and axons) this model makes it possible to dissociate the respective role of the host and of the nerve graft in angiogenesis and suggests the existence of growth factors produced by the human Schwann cells.

Adult↗
PubMed1991

[Helicobacter pylori gastritis: a new infectious disease. Reflections from personal experience].

To determine the relationship of microscopic chronic antral gastritis to Helicobacter pylori, 69 consecutive patients were studied. In a prospective longitudinal study, at least 2 successive gastroscopies with antral biopsies were performed (177 investigations on the whole). Sixty six of the 69 patients were treated with various therapeutic regimens i.e. antiulcer drugs and/or antibiotics. The type and intensity of inflammation (as based on whole inflammatory infiltrate density, polymorphonuclear cells presence or absence and IgA and IgM plasma cells counts) were correlated with H. pylori status (Giemsa staining and/or biopsy culture). The presence of the organism (Hp) and the gastritis were significantly correlated (high grade of whole inflammatory infiltrate Hp + ve: 98/109 90 p. cent, Hp-ve: 9/61 15 p. cent, p less than 0.001--presence of neutrophil PMNC Hp + ve: 80/109 73 p. cent, Hp-ve: 1/61 2 p. cent; p less than 0.001--IgA and IgM plasma cells respectively Hp + ve: 7.6 +/- 6.6, 10.6 +/- 7.1, Hp-ve 1.9 +/- 2.9, 4.2 +/- 4.5; p less than 0.005). Clearance and/or eradication of H. pylori after antibiotic treatment were associated with the disappearance of chronic gastritis activity and a statistically significant decrease of whole inflammatory infiltrate density (p less than 0.001) and IgA (p less than 0.005) and IgM (p less than 0.01) plasma cells counts. Mucosal inflammation was unchanged in case of H. pylori persistence and inflammation worsening occurred in case of infection relapse. H. pylori gastric mucosa colonization seemed to be responsible for the antral chronic inflammation associated with its presence. This study documents that antral chronic gastritis is a microbial disease associated with infection by H. pylori, against which there is an inflammatory response characterized by a significant mucosal infiltration with granulocytes and IgA and IgM secreting plasma cells.

Antacids↗
PubMed1991

[Helicobacter pylori gastritis: a new infectious disease. Reflections from a personal experience].

To determine the relationship of microscopic chronic antral gastritis to Helicobacter pylori, 69 consecutive patients were studied. In a prospective longitudinal study, at least 2 successive gastroscopies with antral biopsies were performed (177 investigations on the whole). Sixty six of the 69 patients were treated with various therapeutic regimens i.e. antiulcer drugs and/or antibiotics. The type and intensity of inflammation (as based on whole inflammatory infiltrate density, polymorphonuclear cells presence or absence and IgA and IgM plasma cells counts) were correlated with H. pylori status (Giemsa staining and/or biopsy culture). The presence of the organism (Hp) and the gastritis were significantly correlated (high grade of whole inflammatory infiltrate Hp + ve: 98/109 90%, Hp-ve: 9/61 15%, p less than 0.001--presence of neutrophil PMNC Hp + ve: 80/109 73%, Hp-ve: 1/61 2%; p less than 0.001--IgA and IgM plasma cells respectively Hp + ve: 7.6 +/- 6.6, 10.6 +/- 7.1, Hp-ve 1.9 +/- 2.9, 4.2 +/- 4.5; p less than 0.005). Clearance and/or eradication of H. pylori after antibiotic treatment were associated with the disappearance of chronic gastritis activity and a statistically significant decrease of whole inflammatory infiltrate density (p less than 0.001) and IgA (p less than 0.005) and IgM (p less than 0.01) plasma cells counts. Mucosal inflammation was unchanged in case of H. pylori persistence and inflammation worsening occurred in case of infection relapse. H. pylori gastric mucosa colonization seemed to be responsible for the antral chronic inflammation associated with its presence.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1990

Sublocalisation of the X breakpoint in the translocation (X; 18)(p11.2; q11.2) primary change in synovial sarcomas.

A specific translocation between chromosomes X and 18 was identified in synovial sarcomas. From a girl with synovial sarcoma, we isolated two clones with t(X; 18)(p11.2; q11.2) and which had lost the normal X chromosome. Southern blot analysis of DNA from the tumor, the patient and her parents demonstrated that the normal X chromosome, lost in the tumor, was the paternal one. A somatic hybrid cell line was established by fusing tumor cells (after passages on athymic mice) to an HPRT deficient hamster cell line. By cytogenetic, in situ hybridization and molecular analysis, it was found to contain the derivative (X) chromosome in the absence of the der (18) chromosome. To determine the position of the breakpoint on the X chromosome, Southern blots of DNA from this hybrid were hybridized to [32P]-labelled X chromosome probes. DXS146 and DXS255 were retained in the hybrid cell line whereas GAPDP1, the ARAF1 and TIMP proto-oncogenes were not present, indicating that the breakpoint lies proximal to GAPD1, ARAF1 and TIMP and distal to DXS255 and DXS146. Results obtained from other authors are compared. Further studies will be necessary to determine the extent of variation of the breakpoint in different tumors.

Blotting, Southern↗
PubMed1990

[In situ hybridization: principles, methods and applications].

In situ hybridization is used to localize DNA or RNA sequences in tissue sections, single cells or chromosome preparations. The preparation and labeling of probes and the main steps of the technique are described and discussed together with its main applications.

Base Sequence↗
PubMed1990

[Cell proliferation in human cerebral tumors. In vivo study of 45 cases by incorporation of 5-iododesoxyuridine].

A method to study the proliferation of human brain tumors, is presented. Non radioactive 5-Iododeoxyuridine (2.4 gr) infused over a 24 hours period is detected in situ on histologic section by an immunological technique (peroxidase-anti-peroxidase) using a specific anti-Iododeoxyuridine antibody. This exploration utilised in 45 patients is easy, reliable and harmless. All cells which enter in S phase of cellular cycle during the infusion are labelled. So the cellular kinetics of all the brain tumor cells (malignant cells, inflammatory stroma reaction cells, reactive astrocytes, endothelial and muscular cells of the vessels) are detected on the same histological section, as well as all the others proliferative cells of the body (leukocytes, primitive tumor of the metastatic brain localisation...) if multiples biopsies are done. 8 of 9 gliomas of low histological malignancy (grade I and II) have a slow cellular kinetic. The 23 astrocytomas of different histological malignancy (grade III and IV) have variable proliferative speed (7 very fast, 8 fast and 8 slow). Only the large cells of the pinealoma are very proliferative, the lymphoid stroma is quiescent. The 5 metastasis have a slow to very fast kinetic without correlation with the cellular differentiation except in one case (important differentiation and slow cellular proliferation). The 5 lymphoma cells kinetics are well correlated with the histologic differentiation (3 large cells poor differentiated lymphomas and very fast kinetic, 2 better differentiated and slower proliferation). The 2 meningiomas proliferate slowly. The biochemical and histopathological grounds of the presented method and the limits of quantification are discussed. This method is compared with this using Bromodeoxyuridine. The correlation between proliferation and histologic malignancy is analysed. The use of cytokinetic results for therapeutic and prognosis need further statistical anatomoclinical studies.

Adult↗
PubMed1989

[In vivo study of human tumor cell proliferation, by histo-immunodetection of 5-iododeoxyuridine incorporated into DNA].

5 Iododeoxyuridine (IDU) was administered, (2.4 g by continuous infusion for 24 hrs.) without adverse effect, to 18 patients bearing thoracic tumours. 5 microns tissue sections were incubated with a monoclonal anti-IDU antibody. Cells that had incorporated IDU were identified immunohistochemically. The labelled cells number and situation vary from one tumor cell type to an other, from patient to patient and from territory to territory. The stroma components cells (inflammatory reaction, fibrosis...) were seldom labelled except for neovascularization. Normal tissues have different labelling indexes with their origin.

Adult↗
PubMed1989

[Man-nude mouse tissue chimera: characterization of cell population by in situ hybridization].

In situ hybridization with biotinated probes to total genomic DNAs as well as to the sequences ALu was performed on 13 cutaneous and 19 tumoral human grafts into nude mice. The dermis of cutaneous grafts is progressively overgrown by murine fibroblasts. Primary revascularization took place by development of anastomoses between the human and murine capillary beds. Well-differentiated human neurilemnal sheaths persisted in the grafts until the 6th month. Murine mononuclear cells, resembling Langerhans cells, penetrated the human epidermis. The cells of the fibrous capsules that enclosed the tumors were of mouse origin. Finally, transplantation of human tumors to mice resulted in the replacement of the endothelial and fibroblastic stromal human components by their murine counterparts.

Animals↗
PubMed1988

Experimental and clinical study of fast absorption cutaneous suture material.

Fast Absorption Vicryl was irradiated with gamma rays. The experimental study on 14 mice grafted with human skin showed a constant rupture of the sutures on the 12th day, with the development of a moderate macrophage reaction. Injection of isotonic saline around the suture material did not accelerate the process of resorption. The clinical study with 27 children operated on the limbs showed rupture of the sutures between the 12th and 16th days, without inflammatory reaction, infection or wound dehiscence. Simply wiping the wound with a compress removes the stitches painlessly. This is appreciated by the young subject and his or her family. Since we began to use FAV systematically we have not needed to conduct dressing under anesthesia. The long term results of healing (follow-up: 11.3 months) are similar to those obtained with conventional non-absorbable suture material. The tolerance, the rapid resorption, the comfort of the patient and the cost advantage make FAV the suture material of choice.

Absorption↗
PubMed1988

[Histologic study of the outcome of components of nerves of human corpses grafted in nude mice (a model of chimeric intercellular communication)].

Human corpse nerves are microsurgically grafted in nude mouse and biopsied from 1 to 152 days after graft. Schwann cells ever survived and probably produce angiogenic factors stimulating mice vessels. Others nerves are grafted end to end with mouse sciatic nerve. Mouse's neurites invading grafts are surrounded by human Schwann cells and set up normal chimeric nerve.

Adult↗
PubMed1987

[Histo-immunolocalization of human and murine type I and III collagens in human cancers grafted to congenital athymic mice].

Seven human carcinomas and five sarcomas are microsurgically grafted to the nude mouse. We demonstrate with antibodies to human and murin Type I and III collagens that the capsule of the grafted human tumors and the intratumoral perivascular collagen are always of murin origin. Mouse Type I and III collagens take progressively the place of their human counterparts in the extracellular matrix of carcinoma. In contrast the intratumoral collagens of sarcomas are ever of human nature. The murin collagen, probably induced by the tumors, is perhaps one of the factors which prevents in the nude mouse the metastasis of the human grafted tumors.

Animals↗