Biomedical subjects

M Marois

Publications and source records attributed to M Marois.

At least 19 recordsLinked to original sources

PubMed2001

Interleukin-1 receptor accessory protein is constitutively expressed in human endometrium throughout the menstrual cycle.

Interleukin-1 (IL-1) is one of the principal cytokines that participate in endocrine and local regulation of many endometrial and reproductive functions. The cellular response to IL-1 principally implicates receptor type 1 (IL-1R tI) and, according to recent data, an accessory protein (IL-1R-AcP) that seems to play an essential function in signal transduction. In the present study, we examined the expression of IL-1R-AcP in the endometrium of 39 normal fertile women throughout the menstrual cycle. As studied by immunohistochemistry, IL-1R-AcP was detected across endometrial tissue, but more noticeably in the glands and luminal epithelium. The intensity of IL-1R-AcP immunostaining was consistently high throughout the menstrual cycle, and this was confirmed by Western blot analysis of the protein and corroborated by reverse transcription-polymerase chain reaction analysis of the mRNA. To our knowledge, this is the first report showing that IL-1R-AcP is expressed in endometrial tissue, and without any noticeable variation throughout the menstrual cycle. This suggests that the accessory protein, whose co-expression is critical for IL-1R tI-mediated cell activation, is, in contrast to the functional receptor, constitutively expressed and not subject to similar cycle-dependent regulation.

Adult↗

PubMed1999

Immunohistochemical localization of insulin-like growth factor-binding protein-3 in eutopic and ectopic endometrial tissues.

OBJECTIVE: To evaluate the expression of insulin-like growth factor-binding protein-3 (IGFBP-3) in the eutopic endometrium and in endometriotic lesions. DESIGN: Retrospective immunohistochemical study. PATIENT(S): Twenty-five normal women and 39 women with endometriosis. INTERVENTION(S): Endometrial and endometriotic tissue biopsies obtained at laparoscopy. MAIN OUTCOME MEASURE(S): Expression of IGFBP-3 assessed by immunohistochemistry. RESULT(S): In the endometrium, positive immunostaining of IGFBP-3 was observed both in the stroma and the epithelial glands. The intensity of staining in the glands during the secretory phase was significantly higher in women with endometriosis compared with controls (P = .018). An increased expression of IGFBP-3 over controls was found in stages I and II of the disease (P = .018), whereas in stages III and IV, the difference between controls and women with endometriosis was not significant (P = .300). In endometriotic tissues, a much-marked immunostaining of IGFBP-3 was noted in 90% of the glands and 67% of the stroma without apparent differences related to cycle phase. CONCLUSION(S): These data show intense staining of IGFBP-3 in endometriosis lesions and increased expression of the protein in the endometrium of patients with endometriosis compared to controls. This marked expression of IGFBP-3 could be related to its previous finding in the peritoneal fluid and to its potential involvement in the pathophysiology of endometriosis.

Adult↗

PubMed1998

[Antioxidants, prostaglandins and prematurity].

Preterm labor could have very bad consequences for the new-born. Every method which maintain pregnancy till term deserves to be analyzed. Such an analysis could throw a light on the process of parturition and open therapeutic possibilities against prematurity. Once a food-stuff antioxidant, Diphenyl-p-Phenylene-Diamine (DPPD) given to pregnant rats, delays or prevents parturition. We confirm the results of Oser. The daily dose of 20 mg from the 17th day of pregnancy upsets parturition. If injected from the 14th day, the parturition never occurs on time. Under the same circumstances (from the 14th day) the daily dose of 40 mg, more effective than 20 or 30 mg prolongs the pregnancy duration, causes fetal resorptions and often prevents birth of living fetuses. 200 micrograms of prostaglandin F2 alpha given on the 21st day almost totally cancel the very toxic action of 40 mg of DPPD which has been injected daily from the 14th day. When an antioxidant lengthens the pregnancy duration of rats, prostaglandin F2 alpha reestablish parturition. Thus the parturition delaying action of an antioxidant may be stymied by prostaglandin F2 alpha. This delaying action might be due to an inhibition of the synthesis of prostaglandin. If applied against the threat of preterm birth, it will be necessary to test the innocuity, at the doses used, of the selected antioxidant and the absence of side effects for the mother and fetus.

Animals↗

PubMed1997

Vascugraft polyurethane arterial prosthesis as femoro-popliteal and femoro-peroneal bypasses in humans: pathological, structural and chemical analyses of four excised grafts.

Following positive results obtained in in vitro studies and in vivo implantations in animals, a clinical trial using the Vascugraft polyurethane arterial prosthesis as a below-knee substitute was undertaken in 15 patients. Eight grafts became occluded during the first year, and segments from four of them were explanted and made available for pathological, structural and chemical investigations. The implantation periods ranged from 21 to 358 days. Failures were associated with kinking (one case), possible anastomotic mismatch between the graft and the artery (one case), and poor run-off (two cases). No organized collagenous internal encapsulation was noted; however, endothelial-like cells were observed at the anastomotic site of one graft. No significant structural degradation of the prostheses was observed in those grafts implanted for 21, 38 and 46 days. Some deteriorations in the fibrous structure were observed on the external surface of the prosthesis implanted for 358 days. High-resolution carbon C1s analysis by ESCA demonstrated a 60 to 80% decrease in carbonate content on the surface of all explanted prostheses. Chemical analyses of each polyurethane graft by IR, SEC and DSC revealed no significant chemical changes. The clinical performance of the Vascugraft prosthesis for below-knee implantation proved to be no more impressive than that of expanded polytetrafluorethylene, the currently accepted reference. The decision by B. Braun Melsungen AG to end this program is therefore to be regarded as highly professional.

Aged↗

PubMed1996

An albumin-coated polyester arterial graft: in vivo assessment of biocompatibility and healing characteristics.

The albumin-coated vascular graft (ACG) and its uncoated polyester substrate, the Vascular II (V-II), were evaluated in terms of biocompatibility and biofunctionality using two in vivo animal studies. Biocompatibility and immunoreactivity were assessed by implanting intraperitoneally in the rat small segments of the ACG and the V-II graft and harvesting them with their surrounding tissue 3d, 1, 2 and 4 weeks later. Cytofluorometric determination of total T cells (CD3), the ratio of CD4/CD8 subsets and the percentage of IL-2 receptor-positive T cells in the peripheral blood has revealed that no significant difference in any of the T cell populations was found between the ACG and the V-II graft. The cellular reactivity of the ACG in terms of acid phosphatase activity at the implant side was significantly greater at 3 d but not at longer periods. Biofunctionality was evaluated by implanting both grafts as a thoracoabdominal vascular bypass in dogs for 11 different periods ranging from 4 h to 6 months. The rate of albumin resorption was such that traces were still present at 1 month, but no longer observable at 2 months. Tissue incorporation into the graft wall was earlier for the V-II (2 weeks) than for the ACG (4 weeks), which showed complete encapsulation, tissue incorporation and endothelialization after 2 months in vivo. Only small differences were observed between both grafts in terms of platelet and fibrin uptake on the luminal surface. The prostacyclin/thromboxane A2 ratio increased to a level higher that 1.0 aorta within 1 month for the V-II and 4 months for the ACG. In conclusion, the Bard ACG has demonstrated excellent biocompatibility in terms of blood T cell behaviour and acid phosphatase activity at the implant site. Finally, its healing response is equivalent to that of the uncoated Dacron prosthesis once the albumin coating has been resorbed.

Acid Phosphatase↗

PubMed1995

Carbodiimide cross-linked gelatin: a new coating for porous polyester arterial prostheses.

The performance of a polyester arterial prosthesis impregnated with gelatin and cross-linked with carbodiimide (Uni-graft) was compared with its porous parent graft (Protegraft) using a canine thoraco-abdominal bypass model. The grafts were investigated in terms of their handling characteristics, imperviousness at implantation, surface thrombogenicity and healing behaviour. Prostheses 30 cm in length were implanted for the following periods: 4, 24 and 48 h, 1, 2 and 4 weeks, 2, 3, 4, 5 and 6 months. Both types of graft had good handling characteristics. The ready-to-use impregnated graft provided satisfactory haemostasis at implantation with no blood permeating through the wall after flow was restored. Both grafts exhibited low surface thrombogenicity, as determined by the uptake of labelled fibrin and platelets, and the healing sequence of the impregnated graft after resorption of the gelatin was equivalent to that of the preclotted control. Biodegradation of the gelatin was complete within 1 month of implantation with the subsequent development of a collagenous internal capsule at both anastomoses. Endothelial cells were observed between 4 and 6 months, but were confined to small islets distributed along the luminal surface. The prostacyclin/thromboxane A2 (PGI2/TXA2) ratio, which gives an indication of the level of endothelial cell activity, was greater than 1.0 after 1 week of implantation for the control graft. For the impregnated graft it reached 1.0 only after 3 months of implantation, but remained above 1.0 for periods of up to 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗

PubMed1995

Increased immunohistochemical expression of neutral metalloendopeptidase (enkephalinase; EC 3.4.24.11) in villi of the human placenta with pre-eclampsia.

The purpose of this study was to identify the presence of placental neutral metalloendopeptidase (NEP; enkephalinase; EC 3.4.24.11) in human normotensive and pre-eclamptic pregnancy. The localization of NEP in placentae from normotensive, chronic hypertensive and pre-eclamptic pregnancies was carried out on fresh frozen tissues by using a monoclonal primary antibody developed against human common acute lymphoblastic leukaemia antigen (CD10) together with the avidin-biotin-peroxidase method. In placentae from normotensive, chronic hypertensive and superimposed pre-eclamptic pregnancies, intense staining was found in the extravillous trophoblast, and also in fibroblasts of the chorionic plate and stem villi. Light to moderate staining was noted in the villous-associated trophoblast and in some cells from the villous core. In cases of pre-eclampsia, very intense staining was detected not only on the surface, but also in the cytoplasm of the villous-associated trophoblast. The increased expression of placental NEP in pre-eclampsia suggests that this enzyme may be involved in the regulation of the local concentration of circulating biologically active peptides at the fetomaternal interface, and thus could be implicated in the pathophysiological changes of this syndrome.

Adult↗

PubMed1994

The influence of the number of endoclips and of mesh incorporation on the strength of an experimental hernia patch repair.

The strength conferred to a mesh by fixing it with laparoscopic staples and the effects of tissue incorporation have never been quantified. Eighteen dogs were divided into three groups sacrificed at 2 days (5 dogs), 2 weeks (6 dogs), and 2 months (7 dogs). One 3.5- by 5-cm piece of abdominal wall was removed from each side through a median laparotomy, leaving the skin intact. A polypropylene mesh (5 by 7 cm) was fixed over one defect with four Endopath EMS staples (Ethicon Endo-surgery) and over the other with 16 EMS staples. At sacrifice, bursting strength (BS) was measured with an Instron tester and specimens were studied histologically. One-way analysis of variance and the Newmann-Keuls multiple-comparison test were used. BS tests showed that for each period studied, the strength of the repair performed with 16 staples was significantly higher than that obtained when four staples were applied. They also showed that tensile strength increased significantly in both groups as time elapsed. Light microscopy supported the conclusion that the initial strength of the repair was related to the number of clips and was significantly increased by cellular infiltration at 2 weeks and significantly more by collagen deposition at 2 months. At 2 months, BS was significantly higher in the 16-staples group, suggesting that initial fixation still plays a significant role.

Abdominal Muscles↗

PubMed1994

In vivo performance of the polyesterurethane Vascugraft prosthesis implanted as a thoraco-abdominal bypass in dogs: an exploratory study.

Among the various prototype vascular prostheses that have been developed over recent years as small vessel substitutes, the Vascugraft polyurethane device produced by Braun-Melsungen AG has a number of attractive features. As well as having high mechanical compliance similar to that of the arterial tree, it has been manufactured from a specially synthesized poly(ester urethane) with improved biostability and its microfibrous structure provides a highly porous wall with open communicating pores. With a view to evaluating the in vivo biofunctionality and biostability of this prosthesis in the dog, 10 mm diameter grafts were implanted as thoraco-abdominal bypasses for prescheduled periods of 1 months and 12 months, and their performance monitored in terms of gross morphology, histology and the measurement of the chemical and physical properties of the explanted and cleaned specimens. Both grafts were patent at retrieval. Each had a smooth and glistening flow surface without organized mural thrombi and showed the development of a thin collagenous internal capsule with the presence of endothelial-like cells. Both grafts were well encapsulated externally and revealed a small distal bend or kink which is frequently observed by any thoraco-abdominal bypass in dogs. The fresh explanted prostheses were cleaned by a new enzyme treatment which provided specimens for microscopic, mechanical and thermal analyses, as well as studies of the surface and bulk chemistry. By comparing the results from the explanted and cleaned material with those of the virgin prosthesis, we have observed some deterioration in the integrity of the microfibrous structure, some loss in mechanical performance, marginal changes in molecular weight, and an apparent microphase separation of the hard and soft segment domains at a depth of a few microns. While the biofunctionality of a 10 mm calibre device has been demonstrated, additional in vivo studies are recommended to assess the biofunctionality at different diameters and the biostability over longer periods of implantation.

Abdomen↗

PubMed1993

Expanded polytetrafluoroethylene arterial prostheses in humans: histopathological study of 298 surgically excised grafts.

The expanded polytetrafluoroethylene vascular prosthesis is considered to be the best synthetic alternative for peripheral arterial reconstruction. Most studies on the healing characteristics of expanded polytetrafluoroethylene prostheses have been carried out on animals, and very few data are available on prosthesis implanted in humans long term. We implanted 298 expanded polytetrafluoroethylene grafts as arterial substitutes in humans. The mean duration of implantation was 523 d and the grafts were implanted mainly for infrainguinal or axillofemoral bypass. The cellular and collagen infiltration of the microporous expanded polytetrafluoroethylene structure was generally poor. Infiltration occurred mainly in the external region of the prosthetic wall and increased with the duration of implantation. The external reinforcement was not a major factor in limiting tissue infiltration. The luminal surfaces were covered with a thin, irregular layer of organized fibrin, interspersed with exposed expanded polytetrafluoroethylene areas. Mineral deposits were observed in five cases. Despite poor healing, the clinical performance of expanded polytetrafluoroethylene vascular prostheses is relatively good. Since the chief advantage of this material is good mechanical stability in vivo, any modifications of the graft to improve healing characteristics or thrombogenic properties should not be made at the expense of stability in vivo.

Adult↗

PubMed1992

T lymphocyte modification with the UTA microporous polyurethane vascular prosthesis: in vivo studies in rats.

Sequential quantification of blood T cell subsets by immunocytofluorometry was used to investigate the immune response of microporous polyurethane vascular prostheses after intraperitoneal implantation in rats. The experimental prosthesis, as developed by the University of Texas-Arlington group (UTA), and the Mitrathane prosthesis, as developed by Matrix Med., were implanted for 1, 2 and 6 weeks and compared with ePTFE and wounded rats without prostheses (control group). The implants were examined for histopathology by light microscopy. The percentages of CD4-(helper) and CD8-(suppressor) bearing cells of the PTFE group were significantly lower (p less than 0.05) than the control group 1 week post-implantation. The UTA and the Mitrathane grafts exhibited a significant decrease in both T cell subsets at 1 week, and CD4-bearing cells at 2 weeks. At 6 weeks, T cell subsets were similar among all groups. The ratio of CD4/CD8- cells was similar among all groups except for the PTFE group, which was lower than the control group after 1 week. Histological examination of Mitrathane and UTA grafts showed an acute phase of inflammation which lasted at least 2 weeks. Some foreign body giant cells (FBGC) were present 2 weeks post-implantation, and encapsulation was greater than that observed with PTFE grafts. On the other hand, PTFE grafts exhibited a different pattern of inflammation compared to polyurethane grafts. PTFE implants exhibited a moderate chronic inflammatory response for the first week, as shown by the formation of FBGC. At 2 and 6 weeks, the grafts were encapsulated by a thin layer of collagenous tissue and FBGC were still present around the implants, mostly located in contact with the reinforcing mesh.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1991

Carotid endarterectomy plaques: correlations of clinical and anatomic findings.

To establish possible relationships between the structure of carotid plaque and neurologic symptoms, 187 consecutive endarterectomy specimens were studied prospectively. Each specimen was examined for gross and histopathological features. Intraplaque hemorrhage, although found infrequently, was closely correlated with the presence of symptoms. Plaque ulcerations were encountered more often when lesions were symptomatic. Calcifications were more frequently associated with asymptomatic lesions. Consistency of plaque was related to its morphological features (stenosis or ulceration) and symptoms. Soft plaques with predominant atheromatous grumous material and hemorrhage were associated more often with tightly stenotic, ulcerated, and symptomatic lesions. Consistency of atherosclerotic carotid plaques should be assessed and considered as an important element in the therapeutic decision.

Aged↗

PubMed1991

A pathological study of arterial prostheses surgically excised after overt clinical infection.

Infection caused regarding vascular grafts in vascular surgery still remains a major problem. To reduce this problem and the complications which follow, the surgeon must be able to apply the best surgical management and also be confident with the vascular substitute used. There are two important factors to be considered: the biomaterial must have low propensity to infection and good stability if and when infected. In an attempt to verify this problem, 93 vascular grafts surgically excised for overt infection were examined. Techniques used for examinations were gross morphology, histopathology and scanning electron microscopy (SEM) evaluation. There were 23 human umbilical vein (HUV) grafts, 51 Dacron grafts and 19 expanded polytetrafluoroethylene (ePTFE) grafts. Histopathological signs of infection were absent in 57% of the ePTFE and Dacron grafts and in 17.4% of the HUV grafts. The latter were more heavily histologically infected and in some cases the walls were destructed. Histopathological signs of infection were seen on all the prosthetic walls in 36% of all the specimens and were mainly on the external portion of the grafts for the remaining prostheses. Bacteria were seen in respectively 21.7, 15.7 and 20% of the HUV, Dacron and ePTFE grafts with the Gram stain and in 86.9, 84.3 and 94.7% with SEM. The implantation period was shorter for the bioprostheses compared to that of the synthetic grafts because of the site and the indication of implantation. The stability of the bioprostheses was lower compared to that of the synthetic grafts when infected, leading to a breakdown of the wall along the length of the graft. The infection was found on the external capsule of the grafts rather than on the luminal surface.

Arteries↗

PubMed1990

Human umbilical vein grafts as infrainguinal bypasses: long-term clinical follow-up and pathological investigation of explanted grafts.

This retrospective study examines 105 consecutive infrainguinal bypasses using human umbilical vein (HUV) grafts as blood conduits over a 9 year period. In addition, 39 segments of these grafts were harvested at reoperation and submitted for morphologic, histologic, and scanning electron microscopy examinations. Fifty-two below-knee femoro-popliteal and 53 femoro-distal bypasses were performed in 93 patients. Sixty-seven per cent of these bypasses were performed for either rest pain (18%) or gangrene (49%) and 29% were performed for acute ischemia. Primary and secondary patency rates were not statistically different and were 38% and 29% at 1 and 3 years respectively. Factors found to have a significant effect on patency were site of distal anastomosis, state of distal run-off, and indication for operation. Other complications requiring reoperation included aneurysm formation (8 cases), infection (6 cases), mural thrombus (2 cases), and stenosis (2 cases). Pathologic examination revealed a damaged luminal surface in 22 grafts, deep folds in 8 grafts and delamination of the graft wall in 16 cases. Bacteria were seen in the folds of the grafts and, in addition, the presence of bacteria was documented in 7 out of 26 clinically non-infected grafts. The combination of poor patency rates and pathologic evidence of biodegradative phenomena have led us to discontinue HUV as an arterial substitute.

Adult↗

PubMed1989

An histo-morphological evaluation of ninety surgically excised human umbilical vein grafts.

Morphological, histological, and scanning electron microscopy examinations were performed on 90 surgically excised human umbilical vein grafts. Most of the explanted grafts were removed because of thrombosis or infection and were removed typically from a patient in the mid 60s and after an average duration of implantation of 11 months. Multiple structural defects were found including deep folds, breaks on the luminal surface, and delamination. These areas as well as anastomotic sites represented potential areas for thrombotic accumulation. A higher incidence of infection was observed in grafts composed of 2 or 3 segments. Bacteria were often found in folds and could be seen invading the wall of the prosthesis. In addition, bacteremic colonization was often seen in noninfected grafts. The late aneurysmal formations were also of particular concern. The biodegradation of the wall and the disruption of the polyester mesh were the probable causes. The second generation Dardik Biograft aimed at reducing these formations. The success of this new processing remains to be evaluated.

Adult↗

PubMed1989

In vivo evaluation of hydrophobic and fibrillar microporous polyetherurethane urea graft.

Mitrathane hydrophobic and fibrillar microporous prosthesis was implanted as infrarenal arterial substitute in dogs; it was evaluated in terms of patency rates, healing characteristics and biostability. Segments of grafts were implanted in duplicate for a period of implantation of 24 h, 1 wk, 1 month and 6 month. Two control grafts from the Ontario Research Foundation were implanted: one for 1 month, the other for six month. All except the two Mitrathane grafts implanted for 6 month were patent at death. The Mitrathane grafts showed kinking at one and 6 month post-implantation. The ORF graft implanted for 1 month was found crinkled in its mid-section and the external capsule was ruptured in the graft implanted for 6 month, without crinkling. Histological studies showed fibrin deposits on the flow surface and infiltration of blood elements into the wall of the Mitrathane grafts implanted for 24 h and 1 wk. A thin internal capsule was present on the graft flow surface of both types of graft tested 1 month post-implantation; scanning electron microscopy revealed the presence of endothelial-like cells on the luminal surface, particularly in the vicinity of the anastomoses. At 6 month, the Mitrathane grafts were occluded by a thick thrombus originating from the anastomoses, while the ORF graft showed infiltration of collagen through the polyurethane fibrillar structure of the wall with an endothelial-like lining covering the flow surface in the vicinity of both anastomoses.

Animals↗

PubMed1989

Effect of diabetes on the healing process of synthetic grafts implanted in dogs: a preliminary study.

The deleterious effects of diabetes in peripheral vascular surgery and blood access are generally considered to be associated with the greater failure rate of vascular prostheses. To understand better these phenomena, we investigated the healing characteristics of an ePTFE graft in dogs. The animals were made diabetic after total pancreatectomy and the grafts implanted for scheduled periods of 24 h, 48 h, 1 wk and 1 month, either as thoracic (series I) or abdominal (series II) aortic substitutes. The same implantations were performed in non-diabetic dogs used as controls. The luminal surfaces of grafts implanted in diabetic dogs, either as thoracic or abdominal bypasses, proved to be more invaded by platelets as a result of the blood's increased platelet aggregation properties. The presence of endothelial-like cells spreading over the pannus after 1 month implantation was strikingly different in diabetic versus non-diabetic dogs. In the first group, the cells were fragile and less abundant, whereas in the second they were more adhesive, elongated and orientated in the direction of the blood flow.

Animals↗

PubMed1989

In vivo evaluation of four chemically processed biological grafts implanted as infrarenal arterial substitutes in dogs.

Four chemically processed grafts implanted as arterial substitutes in dogs were evaluated as blood conduits in terms of patency rates, healing characteristics and biostability. Omniflow, Biopolymeric, Dardik-Biograft of the second generation and BIMA grafts were implanted as infrarenal aortic substitutes for 4, 24 and 48 h (short-term), 1, 2 and 4 wk (medium-term), 3 and 6 month (long-term), each type of graft being implanted for a complete series. The explanted grafts were evaluated macroscopically and processed for light and scanning electron microscopy. One Omniflow graft was occluded at 6 months and two Dardik-Biografts were thrombosed, one at 24 h and one at 1 month. All explanted grafts in the Biopolymeric series and in the BIMA were patent at the animals' death. Histological studies revealed frequent subintimal fibrosis in the Biopolymeric and Omniflow grafts. A peripheral inflammatory reaction was present in most grafts explanted. Scanning electron microscopy showed an aggravation of flow surface irregularities, after implantation of Omniflow, Biopolymeric and Dardik-Biograft, compared to virgin prostheses. These grafts presented an internal capsulae on the graft flow surface along the anastomoses. The capsulae slightly extended towards the centre of the graft after long-term implantation, (6 month) and corresponded to the pannus. Endothelial-like cells covered this pannus. The BIMA graft performed the most satisfactorily and retained its blood compatibility best, that is, the luminal surface was smooth with only minor thrombotic deposits and a thin pannus along the anastomotic lines.

Animals↗