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M Reynes

Publications and source records attributed to M Reynes.

At least 73 records · Page 4Linked to original sources
PubMed1990

Graft-versus-host mortality induced by noncytolytic CD4+ T cell clones specific for non-H-2 antigens.

UNLABELLED: The relative contribution of individual non-H-2 Ag and of T cell subsets that initiate graft-vs-host reaction (GVHR) as well as the mechanism responsible for histopathologic lesions are still a matter of debate. To address these questions and to favor the selection of T cells primed in vivo against non-H-2 Ag important in GVHR we derived T cell clones from spleens of (DBA/2 x B10.D2)F1 (H-2d) mice developing this reaction after the graft of B10.D2 (H-2d) cells incompatible for numerous non-H-2 Ag plus Mlsa. The pattern of reactivity of eight selected clones against cells from different strains of mice including (BXD)RI strains indicated that one CD4+ clone is specific for Mlsa and seven additional clones (six CD4+ and one CD8+) are specific for four different non-H-2 Ag (Ag.I-IV) and proliferate in an H-2-restricted manner. The same series of experiments suggested that Ag.I and II are poorly polymorphic and allowed to propose the localisation of the genes controlling Ag.I (chromosome 1) and Ag.III (chromosome 4). All the clones show a triple (alpha, beta, gamma) mRNA transcript for TCR but at their surface they express the alpha/beta-heterodimer. The clone specific for Mlsa expresses V beta 6 and that specific for Ag.IV expresses V beta 8.1. Rapid mortality accompanied by clinical and histologic signs of severe GVHR was observed after administration of CD4+ clones (together with host-syngeneic bone marrow) derived early after grafting and specific for Ag.I and II but not after administration of: 1) CD8+ cytolytic clone derived early after grafting and specific for Ag.IV; 2) CD4+ clones derived late after grafting and specific for Ag.III; and 3) CD4+ clone specific for Mlsa. A clear correlation was established between the capacity of CD4+ clones to induce GVHR mortality, to mediate host-specific DTH and to release a high level of TNF. IN CONCLUSION: 1) the reaction against a single non-H-2 Ag is sufficient to provoke lethal GVHR; 2) the capacity to provoke GVHR mortality depends on antigenic specificity and functional properties of the responding clones; 3) the inflammatory process mediated by CD4+ clones may play a major role whereas the specific CD8+ T cell-mediated cytolytic activity is not necessarily lethal.

Animals↗
PubMed1990

Liver transplantation across ABO blood group barriers.

In a study of 234 liver transplants the 2-year graft survival for ABO-compatible elective (80%) or emergency (76%) liver transplants was significantly higher than that for ABO-incompatible emergency liver transplants (30%). The low survival of ABO-incompatible liver allografts was therefore not related to the emergency conditions. Among 17 patients who received ABO-incompatible liver allografts, primary humoral rejection, with haemorrhagic infiltration of portal tracts and deposition of IgM and fibrinogen on sinusoidal and endothelial cells, developed in 6. Other disadvantages of ABO-incompatible liver allografts were significantly higher frequencies of severe rejection crises, arterial thrombosis, and cholangitis. However, the 1-year survival rate of the patients who received ABO-incompatible grafts was 66%, so the use of ABO-incompatible liver grafts is justifiable in emergencies, when no other donor is available; such transplants may help to save the patient, even at the cost of retransplantation in half of the cases.

ABO Blood-Group System↗
PubMed1990

Idiopathic biliary ductopenia in adults: a report of five cases.

The clinical and pathological findings of five adult cases of idiopathic nonsyndromatic paucity of interlobular bile ducts are reported. Patients were 18-32 years old at the onset of the disease; four presented with pruritus and/or jaundice and one with bleeding of the esophageal varices. Two patients were siblings. Serum alkaline phosphatase counts ranged from 1 to 16 times the upper normal value, and total bilirubin counts ranged from 0.6 to 8.8 mg/dL (10 to 150 mumol/L). Initial liver biopsy showed portal and periportal fibrosis with cholangiolar proliferation and reduction in the number of interlobular bile ducts. Antimitochondrial antibodies were absent, and bile ducts were normal after opacification. The patients were observed for 3-11 years. Repeated liver biopsies in the five patients showed progression of the lesions, with development of biliary type cirrhosis in four. Two of the four patients with cirrhosis died of hepatic failure 3 and 11 years after onset of the disease. In the two other cases, liver transplantation was performed successfully. These cases suggest that chronic cholestasis with marked ductopenia resembling the nonsyndromatic paucity described in infancy and childhood may reveal itself at an adult age. This disorder, possibly familial, may rapidly progress to severe and even fatal liver disease and could be a new indication for liver transplantation.

Adolescent↗
PubMed1990

Serum hepatitis delta virus RNA in patients with delta hepatitis and in liver graft recipients.

We have investigated the usefulness of serum hepatitis delta virus (HDV) RNA detection using a slot hybridization analysis of serum samples from ten patients with acute hepatitis and delta markers (group I), from 28 patients with chronic delta hepatitis (group II) and from seven liver graft recipients with hepatitis B virus (HBV) and HDV related cirrhosis or fulminant hepatitis (group III). The slot-blots were hybridized with both HDV-complementary DNA and single-stranded RNA probes. With the single-stranded RNA probe, HDV RNA was detected in the first serum sample available in 9/10 of the patients with acute hepatitis (group I). In addition, HDV RNA was detected in 8/9 and 7/8 of the samples obtained within and after 1 month of the onset of hepatitis. Five of the ten patients scored positive for HDV RNA and negative for hepatitis delta antigen (HDAg) while one was negative for HDV RNA and positive for HDAg. The same RNA probe enabled the detection of serum HDV RNA in 21/28 chronic hepatitis patients (liver HDAg and/or IgM anti-HD positive) (group II). Among the liver graft recipients (group III), 7/7 had a recurrent delta infection. Serum HDAg, liver HDAg and anti-HD IgM were identified in 3/7, 6/7 and 5/7 of the patients, respectively. HDV RNA was detected in the seven patients with either persistent (4/7) or transient (3/7) positivity. In addition, HBsAg and HBV RNA were persistently shown in 4/7 patients with continuous HDV replication. In the remaining three patients, HDV RNA was detectable despite the absence of HBsAg.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Persistent hepatitis B virus infection of mononuclear blood cells without concomitant liver infection. The liver transplantation model.

We have investigated the recurrence of Hepatitis B virus (HBV) in 30 patients treated by orthotopic liver transplantation and given high doses of anti-HBs immunoglobulin. The polymerase chain reaction (PCR) assay showed no evidence of HBV DNA sequences in the liver of 23/24 patients who remained serum HBsAg-negative during a mean follow-up of 13 months (2-24 months) after OLT. However, the liver scored positive in all the 6 individuals in whom HBsAG reappeared. The PCR assay identified HBV DNA sequences in the peripheral blood mononuclear cells of 7 of 11 subjects who were serum HBsAG-negative and liver HBV DNA-negative by PCR. Therefore, this application of the sensitive PCR assay demonstrates persistent infection of PBMC in the absence of liver HBV--thus OLT provides a model for studying the interaction between HBV, PBMC, and the liver.

DNA, Viral↗
PubMed1990

Specific absorption of lymphocytotoxic alloantibodies by the liver in inbred rats.

It has been suggested that liver allografts are less sensitive to lymphocytotoxic antibodies than other organ allografts. In this experimental study in sensitized inbred rat recipients, we have used extracorporeal liver hemoperfusion to study interactions between the liver and lymphocytotoxic antibodies. Donor-specific liver hemoperfusion can delay hyperacute rejection of heart allografts and reduce the level of lymphocytotoxic antibodies. Immunofluorescence examination of the hemoperfused liver revealed deposits of C3 on Kupffer cells and of IgG on sinusoidal cells. In control rats in which a third-party liver, a donor-specific splenic or renal hemoperfusion was performed, heart allograft survival was less prolonged. The decrease in antibody levels was not significant and the deposit of C3 and IgG was much less evident. Similarly, previous blockade of the Kupffer cells of the donor-specific hemoperfused liver by dextran sulfate suppressed the effect of liver hemoperfusion. These results support the hypothesis that resistance of the liver to hyperacute rejection might be due to a massive and nontoxic absorption of lymphocytotoxic antibodies onto nonparenchymal liver cells.

Animals↗
PubMed1990

Distribution of the MHC antigens after liver transplantation: relationship with biochemical and histological parameters.

The aim of this study was to analyse the change in tissue distribution of HLA class I and class II molecules in patients during the course of liver transplantation. Sixty-one liver biopsies were analysed in 24 patients with or without rejection (acute or chronic) episode. In 93% of cases with chronic rejection and in 48% of cases with acute rejection episodes, HLA class I antigens are expressed in the membrane and/or the cytoplasm of hepatocytes. The expression of these molecules was significantly correlated with the ASP (aspartate amino transferase), AP (alkaline phosphatase), the bile duct damage and the centrolobular lesions. In contrast, the expression of HLA class II molecules is not correlated with either the type of rejection, the biological or histological findings. A strong expression of HLA class I antigen on hepatocytes after day 60 may be one of the best signs of chronic rejection.

Graft Rejection↗
PubMed1989

Epithelioid hemangioendothelioma of the liver: an ultrastructural study.

Epithelioid hemangioendotheliomas are uncommon vascular tumors, mainly observed in lung and soft tissues. Liver involvement is infrequent and, in contrast to the extrahepatic localizations of the tumor, has not been subjected to detailed ultrastructural analysis. This prompted us to report the results of the ultrastructural study of three cases of epithelioid hemangioendothelioma of the liver. Neoplastic proliferation was heterogeneous. Most of neoplastic cells presented features suggestive of endothelial differentiation, including presence of Weibel-Palade bodies and evidence of vasoformative properties demonstrated by formation of both intra- and extracellular vascular channels resembling the normal structures successively observed during embryogenesis and tissue regeneration. A minor cell population, unreported so far, exhibited ultrastructural characters resembling those of pericytes and presented organoid relationship to neoplastic endothelial cells. Tumor spreading along sinusoids induced pseudopeliotic dilatations and led to a progressive disruption of normal liver architecture. In conclusion, the three cases of hepatic epithelioid hemangioendothelioma examined in this work assume many organoid features mimicking the successive steps of normal angioformation and indicative of a high degree of morphological differentiation.

Adult↗
PubMed1989

Regression of the malignant aspects of intraepithelial neoplasias following an LH-RH agonist treatment and detection of human papillomavirus by molecular hybridization.

Patients presenting genital intraepithelial neoplasia and/or flat condyloma were treated with DTrp6-LH-RH (triptorelin) to induce a transitory suppression of estrogens. This treatment led in some cases to a complete clinical and histological regression accompanied by a disappearance of human papillomavirus sequences as detected by molecular hybridization.

Antineoplastic Agents↗
PubMed1989

Squamous cell carcinoma in situ developing in dermoid cyst of the ovary. Report of a case with laminin immunohistochemical staining demonstrating basement membrane integrity.

Among malignancies arising in dermoid cyst of the ovary, squamous cell carcinoma in situ is very unusual and set a problem of diagnosis and prognosis. In fact this diagnosis is very difficult and here we report the case of a 30-year-old woman with a squamous cell carcinoma in a dermoid cyst of the right ovary for which laminin immunohistochemical staining allowed us to prove beyond any doubt the in situ character. This demonstration is of great importance because the prognosis of a squamous cell carcinoma in dermoid cyst depends on the degree of penetration of the tumor; so in this young patient a conservative surgery could be carried out. Four years later the very good evolution confirms the accuracy of the diagnosis of squamous cell carcinoma in situ in dermoid cyst and emphasizes the benefit of laminin labelling in order to rule out the possibility of invasive carcinoma.

Adult↗
PubMed1989

Improved survival with splenic autotransplantation and fibronectin therapy following endotoxin administration in rats.

The risk of overwhelming infections is greatly increased after splenectomy. In this experimental study in rats, we investigated whether the administration of fibronectinrich cryoprecipitate can improve the survival rate of splenectomized autotransplanted rats subjected to an intravenous challenge with endotoxin. Inbred Lewis rats were divided into four groups: A, splenectomy; B, splenectomy + splenic autotransplantation; C, splenectomy, splenic autotransplantation + fibronectin treatment, and D, sham. Five months after surgery, rats were challenged intravenously with Escherichia coli endotoxin. Immunoglobulin (IgG, IgM, IgA), complement and fibronectin levels were measured before surgery and endotoxin challenge, and 48 h after endotoxin challenge. The survival rate of splenectomized rats was not significantly improved by autotransplantation of splenic tissue, but was significantly (p less than 0.05) improved by autotransplantation and fibronectin treatment. The levels of fibronectin, immunoglobulins and/or complements were significantly decreased after endotoxin challenge in control and in autotransplanted fibronectin-treated rats. The survival improvement of autotransplanted rats treated by fibronectin is probably due to increased endotoxin phagocytosis and clearance.

Animals↗
PubMed1989

Extent of hepatectomy in the rat. Evaluation of basal conditions and effect of therapy.

In the present study, subtotal hepatectomy was evaluated as a model of acute liver failure in the rat. Sprague-Dawley rats, weighing 250-300 g, underwent hepatectomy under varying basal conditions of temperature and glucose administration. Rats operated and maintained postoperatively at ambient temperature (25 degrees C external environment) developed hypothermia with a rate of return to normal temperature which was related to the extent of hepatectomy and the availability of glucose postoperatively. However, no significant difference in survival was observed between groups maintained at ambient temperature and those whose core temperature was maintained at 37 degrees C by passive external warming. Severe hypoglycemia was observed in rats undergoing 90 and 95% hepatectomy without glucose postoperatively. With 20% glucose available in drinking water the mortality of 90% hepatectomy was reduced from 95 to 40% (p less than 0.0001). With increase of the hepatectomy to 95%, 90% mortality was observed despite glucose support. Transplantation of 4 x 10(7) isolated syngeneic hepatocytes intraperitoneally at the time of hepatectomy did not increase survival after 90 or 95% hepatectomy; addition of testosterone therapy did not improve survival either alone or with hepatocyte transplantation. In this study, hepatectomy exceeding 90% was lethal and did not respond to the supportive measures provided. Hepatocyte transplantation and testosterone pretreatment, both therapies which are thought to increase regeneration, were ineffective in improving survival in this resection model.

Animals↗