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Biomedical subjects

M Reynes

Publications and source records attributed to M Reynes.

At least 91 records · Page 5Linked to original sources
PubMed1988

Epithelioid hemangioendothelioma of the liver. Diagnostic features and role of liver transplantation.

Five cases of epithelioid hemangioendothelioma of the liver are reported. This unusual type of vascular tumor is often difficult to diagnose; its angiogenic nature is not overt at the radiologic level and may be overlooked by conventional histologic examination. At imaging procedures, epithelioid hemangioendothelioma of the liver presents as multiple focal hypovascular areas, disseminated in both lobes. The combination of these imaging abnormalities with a peculiar set of demographic and clinical features, including young age, good general condition, and progressive course, is suggestive. However, the final diagnosis can be established only by histologic examination of appropriate material collected by guided liver biopsies and may be helped by immunohistochemistry and ultrastructural examination. The accurate diagnosis of epithelioid hemangioendothelioma of the liver is of clinical and therapeutic relevance. In view of its favorable clinical course, orthotopic liver transplantation may be considered for the treatment of this tumor when intrahepatic dissemination contraindicates partial hepatectomy and extrahepatic extension, excluded by exploratory laparotomy, is absent.

Adult↗
PubMed1988

Persistence of Trypanosoma cruzi antigens in the inflammatory lesions of chronically infected mice.

Different tissues and organs of mice infected with Trypanosoma cruzi trypomastigotes have been examined for the presence of parasites and parasitic antigens during both the acute and the chronic phases of infection. Specimens of skeletal and cardiac muscles, spleen, liver, brain and sciatic nerves were studied by histological and immunological methods. During the acute phase of infection, the parasites were commonly observed in these tissues. In the chronic phase of the experimental infection, pseudocysts filled with amastigotes were seen in less than 1% of the tissue sections, while immunohistological methods showed that T. cruzi antigens were present in 11% of the inflammatory infiltrates. These findings suggest that antigenic stimulation persists throughout the chronic phase, even though the parasites are not morphologically detectable.

Animals↗
PubMed1988

Relationship between the liver and lymphocytotoxic alloantibodies in inbred rats. Specific absorption by nonparenchymal liver cells.

Liver allografts have a privileged status with regard to hyperacute rejection. In this experimental study, we have used extracorporeal liver hemoperfusion in sensitized rats in order to analyze reactions between lymphocytotoxic antibodies and the liver. In sensitized BN rats, a donor-specific (Lewis) extracorporeal liver hemoperfusion can delay hyperacute rejection of heart allografts and reduce the level of lymphocytotoxic antibodies. The decrease in the level of antibodies could be due to massive absorption of antibodies by the liver or to release of major histocompatibility complex antigens in a soluble form. Immunofluorescent examination of the hemoperfused liver revealed important deposits of C3 on Kupffer cells and of IgG on sinusoidal cells. On the contrary, in control rats in which a third-party (DA) liver hemoperfusion was performed, heart allograft survival was less prolonged, the decrease in the level of lymphocytotoxic antibodies was not significant, and the deposits of IgG and C3 were much less evident. The level of circulating immune complexes was unchanged after a donor-specific or a third-party 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 on nonparenchymal liver cells.

Absorption↗
PubMed1986

LAV-like viral particles in lymph node germinal centers in patients with the persistent lymphadenopathy syndrome and the acquired immunodeficiency syndrome-related complex: an ultrastructural study of 30 cases.

The detection of LAV- or HTLV III-type viral particles in lymph node germinal centers from patients with the persistent lymphadenopathy syndrome (LAS) or the acquired immunodeficiency syndrome (AIDS)-related complex (ARC) is an important diagnostic factor in the prodromal stages of AIDS. These particles, the morphology of which is defined, are situated solely in the extracellular spaces delimited by cytoplasmic extensions of the dendritic reticular cells. Often few in number, they were found in 26 of the 30 lymph nodes studied, selected uniquely on the basis of light microscopic criteria (predominantly follicular lymphoid hyperplasia). The four negative nodes contained no, or fewer than two, germinal centers in the samples taken for ultrastructural study. The diagnosis of the LAS or the ARC was always confirmed clinically and biologically. Thus, lymph node biopsy and the corresponding ultrastructural study are important steps in the diagnosis of AIDS.

AIDS-Related Complex↗
PubMed1986

Non epidermotropic cutaneous lymphoma ending in leukemia. A case of adult T cell lymphoma (ATL) in France?

A case of uncommon non Hodgkin malignant lymphoma with initial skin involvement is reported. The pathological pattern does not come under standard classifications. An aspect of non epidermotropic diffuse pleomorphic lymphoma is observed. In an immunological cell membrane study, the T-cell lineage of the malignant proliferation exhibited a very unusual pattern including the presence of the E rosette receptor and the expression of HLA-DR monomorphic determinant. This type of T cell malignant lymphoma can probably be included in the group of adult T cell leukemia/lymphoma (ATL) which is endemic in South Western Japan and occasionally observed in Western countries. The emergence of such cases in these countries raises important epidemiological questions.

Adult↗
PubMed1986

[Ultrastructural study of 36 lymph node sites of Hodgkin's disease].

The authors report their ultrastructural findings of 36 involved lymph-nodes in Hodgkin's disease (HD), before any treatment. More than 400 tumour cells were studied. An analytical study was carried out on the different aspects presented by the nuclei (uni or multi-lobated); the nucleoli (compact, reticulate or dispersed); and the cytoplasm (immunoblastic, complex, intermediate). No cellular structure evoking phagocytic activity with digestion, and consequently an eventual histiomonocytic origin, could be detected even on serial sections. The presence of lipid inclusions, sometimes of glycogen, as well as certain peculiar structures are described and discussed. The ultrastructural aspects could be easily correlated with the different types of tumour cell described in HD using light microscopy. The various kinds of cells which could could be detected in the same lymph node, may correspond to a real tumour cell lineage, consisting, firstly, of a cell of immunoblastic type with a mono- or bilobated nucleus, then an intermediate type with a bilobated or multisegmented nucleus, and finally a complex cell type with a multisegmented nucleus. The lacunar cells are characterised by a fragile hyaloplasm, without cellular organelles at their periphery, these being concentrated around the nucleus. This special organisation explains the aspects observed in light microscopy. However, no explanation could be offered to understand this particular aspect of the cytoplasm. The ultrastructural characteristics of the Reed-Sternberg cells and their variants did not allow a precise cellular origin to be proposed. The absence of phagolysosomes pleads against a histiocytic origin. However their similarity of the interdigitated reticular cells did not seem sufficient to propose this origin. The likeliness of the cytoplasm of cells with mono- or bilobated nuclei with that of immunoblasts, constitutes the most interesting morphological feature. This fact, associated with the appearance of immunoblasts similar to Reed-Sternberg cells of infectious mononucleosis, suggests a lymphoid origin. The study of the reactive cells around the tumor cells did not allow any consequences to be drawn. One could simply note that the Reed-Sternberg cells and their variants were surrounded by lymphocytes, forming a kind of crown. No etiological agent could be detected. These data are compared to those of other publications, and discussed. This ultrastructural study, therefore, does not offer the solution to most of the questions which still remain to be answered as to the origin of the Reed-Sternberg cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Biopsy↗
PubMed1985

Lymph node modification in patients with the acquired immunodeficiency syndrome (AIDS) or with AIDS related complex (ARC). A histological, immuno-histopathological and ultrastructural study of 45 cases.

The authors present the results of a histopathological study on the lymph-nodes taken from 45 subjects suffering from either an AIDS or from a chronic adenopathy corresponding to the definition of AIDS related complex (ARC). The various aspects observed were classed as type I to type IV. The lymph-node modifications observed in the 29 patients with an ARC could be divided into three principle groups: an extensive follicular hyperplasia associated with other elementary lesions or type IA (25 lymph-nodes from 23 patients); changes resembling a multicentric Castleman syndrome or type IB (1 case); angioimmunoblastic-like (AIL) lesions or type II (2 cases) and an association of lesions of type II (7 lymph-nodes from 6 patients). During AIDS, the adenopathy usually disappears, and the small lymph-nodes removed, especially on autopsy, show an extensive lymphoid depletion (type III) with systematic sclerosis (15 lymph-nodes from 14 patients). When adenopathy persists, it is due to infections complications (tuberculosis, cryptococcosis, avian mycobacteriosis and Whipple's disease like lesions). Of the 10 patients in whom a Kaposi's sarcoma was observed, only 6 showed lymph-node involvement, or type IV. The different histopathological lesions seem to appear according to an evolving succession, proven by certain association of lesions and by successive biopsies. In our series, 17% of subjects with an ARC evolved to AIDS. Lymph-node biopsy allows a possible ARC to be implicated on the association of the following simple lesions: follicular hyperplasia with partial or total destruction of the perifollicular lymphocytic cisterna, infiltration of the germinative centres by streams of small lymphocytes, evolving to an aspect of a "burst" germinative centre and various sinusal reactions with, in particular, the presence of neutrophilic polynuclear cells. The biopsy also allows the forms with bad prognosis to be recognized: those with AIL-like aspect or multicentric Castleman-like syndrome, which seems to represent a particular evolutive form. Finally, it also detects, in certain cases, the localization of a Kaposi syndrome, signalling the passage to AIDS. The immunopathological studies present a double interest. Firstly, they offer arguments in favour of the diagnosis: increase in the number of T8 lymphocytes in the germinative centres with the formation of small clusters and disruption of the network of dendritic reticular cells, and the inversion of the T4/T8 ratio in the extra-follicular cortical regions, by either a decrease in T4 lymphocytes or by an increase in T8 lymphocytes.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1985

Human follicular dendritic cells express CR1, CR2, and CR3 complement receptor antigens.

The expression of complement receptors by human follicular dendritic cells (FDC) was investigated by immunohistochemical techniques by using polyclonal and monoclonal antibodies to antigenic determinants of CR1, CR2, and CR3. Upon optical immunohistochemical examination of frozen sections from human reactive lymph nodes and tonsils by a three-step immunoperoxidase technique, a strong staining of cell bodies and cytoplasmic extensions of FDC was observed in germinal centers with anti-CR1 and anti-CR2 antibodies. Staining for these antigens was also found on cytoplasmic extensions of FDC in the mantle zone and on the plasma membrane of B cells in the entire follicles. Staining of FDC with anti-CR2 antibody was more intense than that of B lymphocytes. Monoclonal antibodies directed against epitopes of the alpha-chain of CR3 weakly stained FDC in follicles in a similar pattern to that which was observed on adjacent sections with mouse monoclonal antibody KIM4 that only recognizes FDC in human lymph nodes. Immunoelectron-microscopy was performed on frozen sections of a lymph node involved with a centroblastic centrocytic B malignant lymphoma and a reactive tonsil with the use of rabbit F(ab')2 anti-CR1 antibodies and mouse monoclonal anti-CR2 antibody. All the plasma membrane of the cell body and cytoplasmic extensions of FDC in germinal centers and in the mantle zones homogeneously stained for CR1 and CR2 antigens. Fibroblastic reticulum cells were negative. The plasma membrane of tumoral B lymphocytes strongly stained with anti-CR1 and weakly stained with anti-CR2 antibodies. The presence of CR1, CR2, and CR3 on FDC is a unique surface characteristic of these cells that should optimally allow the cells to bind antigen/antibody complexes bearing any type of C3 fragment.

Antibodies, Monoclonal↗
PubMed1984

Immunoelectronmicroscopic profile of intracytoplasmic immunoglobulins in B non Hodgkin's malignant lymphomas. Comparison with the normal pattern of B lymphoid cells.

An immunoelectronmicroscopic method using Fab fragment of anti human IgG (H + L) has been employed to study the localization of cytoplasmic immunoglobulins in the tumoral cells of 12 B non Hodgkin's malignant lymphomas (B-M.L.). A comparison with normal homologous B lymphoid cells was performed on 10 non tumoral reactive lymph nodes. Immunostaining was observed in PNC, RER and Golgi complex. The criterions of differentiation were discussed in the different B-M.L.. Because of a granular hyaloplasmic immunostaining in normal and tumoral centroblasts and immunoblasts, monospecific antibodies against gamma, mu, alpha heavy chains were used to rule out a non specific uptake. Presence of mu heavy chain was discussed as an argument for immunoglobulin free ribosomal synthesis.

B-Lymphocytes↗
PubMed1984

[Cervical intraepithelial neoplasms and flat condylomata. Study of 165 cases].

205 cervix biopsies and diagnostic conisations performed among 165 women with dysplasias and carcinomas in situ (CIS) where revised with actual concepts of flat condylomata (FC) and cervical intraepithelial neoplasias (CIN). Usual statistical tests were used to analyse the signification of the average age of the different group (FC alone, FC + CIN, CIN alone) and according to the different grades of CIN. The association between FC and the different grades of CIN was studied with the X2 test. In 66.8% of the cases, FC was present, associated or not with CIN. That ends up to a modification of the diagnosis in 37.6% of the cases (reduction of a grade of CIN, substitution of a mild dysplasia CIN I by a FC). In 33.8% of the cases, FC was associated with CIN. In this work, the average age between CIN associated with FC was 8 years less than CIN alone. The X2 test applied to the frequency of association between FC and CIN according to the grade of CIN have shown that it exists a statistically valid difference between the grades. More the grades is high, more the morphological characters of the FC are rare. These observations suggest an integration of the viral genome in the host genome as it has been proved for the shope papilloma and the verruciformis epidermodysplasia.

Adult↗