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J P Merlio

Publications and source records attributed to J P Merlio.

At least 37 records · Page 2Linked to original sources
PubMed2000

[One heat-induced antigen retrieval step allows the sequential detection of two antigens on the same slide of tissue fixed and enclosed in paraffin].

The heat-induced antigen retrieval (HIAR) procedure allows the immunohistochemical detection of various antigens on paraffin-embedded sections. The re-use of slides negative for the detection of a first set of antigens may be an interesting alternative in case of a limited number of slides. After HIAR, a series of Bouin's liquid-fixed tonsil sections was stained for Epithelial Membrane Antigen (EMA) which labelled epithelial cells and plasma cells. A second immunostaining for CD20 (L26) was performed on the same slides divided in two sets. The HIAR was repeated in the first set but not in the second one. A similar staining of follicular B-cells was observed in the two sets. However background staining was enhanced by repetition of HIAR. Analogous results were obtained using anti-cytokeratin (KL1) instead of anti-EMA. This was confirmed on slides for which three or four cycles of HIAR were performed prior immunostaining. Our data suggest that the renewal of the HIAR procedure must be avoided since it was found stable for at least 1 year.

Antigens↗
PubMed1999

Expression of neurotrophins and their receptors in human bone marrow.

The expression of neurotrophins and their receptors, the low-affinity nerve growth factor receptor (p75LNGFR) and the Trk receptors (TrkA, TrkB, and TrkC), was investigated in human bone marrow from 16 weeks fetal age to adulthood. Using reverse transcription-polymerase chain reaction, all transcripts encoding for catalytic and truncated human TrkB or TrkC receptors were detected together with trkAI transcripts, whereas trkAII transcripts were found only in control nerve tissues. Transcripts for the homologue of the rat truncated TrkC(ic113) receptor were identified for the first time in human tissue. Stromal adventitial reticular cells were found immunoreactive for all neutrophin receptors. In contrast, hematopoietic cell types were not immunoreactive for p75LNGFR but showed immunoreactivity for one or several Trk receptors. TrkA immunoreactivity was found in immature erythroblasts. Catalytic TrkB immunoreactivity was observed in eosinophilic metamyelocytes and polymorphonuclear cells. Truncated TrkB immunoreactivity was found in erythroblasts and megacaryocytes. Immunoreactivity for both catalytic and truncated TrkC receptor was observed in promyelocytes, myelocytes, some polymorphonuclear cells and megacaryocytes. Neutrophin transcript levels appeared higher at fetal than at adult stages, no variation in Trk family transcript levels was observed. The local expression of neurotrophin genes suggests a wide range of paracrine and/or autocrine mode of action through their corresponding receptors within the bone marrow.

Adult↗
PubMed1999

Differential expression of NGF receptors in human thymic epithelial tumors.

NGF receptor (TrkA and p75NGFR) expression was investigated in human thymuses, including normal thymuses, thymic hyperplasias, thymomas and thymic carcinomas. TrkAI but not TrkAII transcripts were demonstrated by RT-PCR. In normal thymuses, immunohistochemistry revealed a restricted TrkA-immunoreactivity to epithelial and interdigitated reticular cells, while only interdigitaded reticular cells were immunoreactive for p75NGFR. Thymocytes were negative for both receptors. A switch from the normal TrkA positive-p75NGFR negative phenotype to a TrkA negative-p75NGFR positive phenotype was found in histologically aggressive epithelial cell tumors, suggesting that NGF and its receptors are potentially involved in thymus stroma organogenesis and proliferation.

Antigens, Nuclear↗
PubMed1999

Meningeal involvement by a transformed mycosis fungoides following Hodgkin's disease.

A 58-year-old man had long-standing lesions of presumed large plaque parapsoriasis. Following treatment for nodal Hodgkin's disease (HD), these became more infiltrated, with a diagnosis of mycosis fungoides (MF). A few months later, nodules appeared on the right leg, which was lymphoedematous after inguinal irradiation for HD. Histopathological examination showed CD3+, CD30-, CD15- large pleomorphic lymphocytes, leading to the diagnosis of transformed MF. The cutaneous lesions were successfully treated with topical nitrogen mustard and interferon alfa-2b then methotrexate, but his general health worsened with depression and malaise, without specific neurological symptoms or extracutaneous spreading of the lymphoma. Cerebral computed tomographic scan revealed a cerebellar subdural collection, arachnoid cyst and quadriventricular hydrocephaly, initially considered to be non-specific. After a few weeks, clinical symptoms of intracranial hypertension appeared, and a cerebrospinal fluid (CSF) examination revealed meningeal involvement by the lymphoma. These cells were CD3-negative and the diagnosis was confirmed by polymerase chain reaction (PCR) study, which revealed an identical clonal rearrangement of the T-cell receptor gamma gene between cutaneous biopsies and the CSF. Repeated intrathecal injections of methotrexate and cranial irradiation were performed and the patient was still alive after 13 months. This case illustrates the possible meningeal involvement of MF that may be preceded by atypical and mild neurological or psychiatric symptoms, which may be dissociated from the evolution of the cutaneous lesions. Moreover, PCR study may be useful for both diagnosis and monitoring.

Follow-Up Studies↗
PubMed1999

The Spectrum of Cutaneous Lymphomas in HIV infection: a study of 21 cases.

We studied 21 HIV-associated lymphomas with cutaneous presentation to determine whether they showed features of primary cutaneous lymphoma arising fortuitously or whether they represented the cutaneous involvement of AIDS systemic lymphoma. Besides rare mycosis fungoides (n = 3), which shared typical clinicopathologic lesions, nonepidermotropic large-cell lymphomas (n = 18) were predominant. They frequently presented as a solitary nodule or tumor. Seven of the eight large T-cell lymphomas had a CD30-positive (CD30+) phenotype but did not express ALK protein. Overexpression of p53 protein was observed in six cases. Although EBV-EBER transcripts were detected in two of them, LMP1 protein was absent. Except for their original prevalence, the features of these T-cell CD30+ cutaneous lymphomas were the same as in immunocompetent patients. The 10 B-cell cutaneous lymphoma were immunoblastic or centroblastic lymphomas, with a differential expression of BCL-6 and Syndecan. Four of them expressed CD30, EBER-EBV transcripts, and LMP1 and p53 proteins. This B-cell CD30+ EBV+ phenotype contrasts with cutaneous lymphoma in immunocompetent patients. Human herpesvirus 8 was not involved in lymphomagenesis since its sequences were detected in a single patient with Kaposi's sarcoma and Castleman's disease. These lymphomas occurred in severely immunocompromised patients with a low CD4 count. Death was due to immunodepression rather than to lymphoma spread, suggesting avoiding aggressive immunosuppressive treatment in such patients.

Adult↗
PubMed1998

Characterization of t(2;5) reciprocal transcripts and genomic breakpoints in CD30+ cutaneous lymphoproliferations.

NPM-ALK chimeric transcripts, encoded by the t(2;5), lead to an aberrant expression of ALK by CD30+ systemic lymphomas. To determine if t(2;5) is involved in cutaneous lymphoproliferative disorders, we studied 37 CD30+ cutaneous lymphoproliferations, 27 mycosis fungoides (MF), and 16 benign inflammatory disorders (BID). NPM-ALK transcripts were detected by nested reverse transcription-polymerase chain reaction (RT-PCR) in 1 of 11 lymphomatoid papulosis (LyP), 7 of 15 CD30+ primary cutaneous T-cell lymphoma (CTCL), 3 of 11 CD30+ secondary cutaneous lymphoma, 6 of 27 MF, and 1 of 16 BID. However, the expression of NPM-ALK transcripts was not associated with ALK1 immunoreactivity in MF, LyP, or BID cases. Only 1 CD30+ primary CTCL and 3 CD30+ secondary cutaneous lymphoma were ALK1 immunoreactive. The ALK1+ cases were also characterized by amplification of tumor-specific genomic breakpoints on derivative chromosome 5. These cases, except for 1 secondary cutaneous lymphoma, were also characterized by reciprocal breakpoints on derivative chromosome 2, leading to the expression of reciprocal ALK-NPM transcripts. Amplification of chromosomal breakpoints on both derivative chromosomes could represent an alternative to conventional cytogenetics for the diagnosis of t(2;5) and seems to be more reliable than the detection of cryptic NPM-ALK transcripts by nested RT-PCR.

Base Sequence↗
PubMed1998

Expression of NGF receptors in normal and pathological human thymus.

The expression of NGF receptors was investigated in normal human thymus and in thymic hyperplasias, thymomas and thymic carcinomas. By RT-PCR, we detected TrkAI transcripts encoding for the high-affinity NGF receptor. Western blot analysis showed the presence of both TrkA and p75NGFR proteins. In normal thymuses, epithelial subcapsular and medullar cells were TrkA immunoreactive. Interdigitated medullar cells were stained for both TrkA and p75NGFR. While epithelial cells of normal thymuses or benign thymomas exhibited a TrkA positive-p75NGFR negative phenotype, a switch to a TrkA negative-p75NGFR positive phenotype was observed in malignant epithelial cell tumours and was associated with cell proliferation-associated MIB1 expression. Our results argue for a local role of NGF and its receptors on thymic stromal cells both in normal and neoplastic conditions.

Adolescent↗
PubMed1998

Low prevalence of monoclonal B cells in Helicobacter pylori gastritis patients with duodenal ulcer.

We have studied the prevalence of B-cell clonality among a large group of 320 patients with Helicobacter pylori gastritis and duodenal ulcer. These patients underwent endoscopic examination with multiple gastric biopsies at diagnosis and were followed 2 and 12 months after therapy. Histopathologic examination of 809 sets of biopsy specimens showed lymphoid gastritis with lymphoid aggregates or follicles, but without lymphoepithelial lesion, in 302 samples corresponding to initial biopsy specimens (n=130) or to posttreatment biopsy specimens (n=172). DNA extracted from fresh antral specimens allowed the amplification of Helicobacter pylori DNA in all cases before therapy. The arrangement of the immunoglobulin heavy chain gene was studied by polymerase chain reaction (PCR) in the 302 selected lymphoid gastritis samples. Single or dominant bands were seen only in four specimens from three patients (1.3%), whereas a polyclonal pattern was seen in the other 298 samples. The detection threshold of our PCR technique was approximately 3% of clonal B cells diluted in a polyclonal population. This threshold appeared to be a reliable cutoff between polyclonal gastritis and clonal MALT lymphoma. In our experience, Helicobacter pylori lymphoid gastritis appeared mainly as a benign polyclonal condition.

Adult↗
PubMed1998

Statistical evaluation of diagnostic and prognostic features of CD30+ cutaneous lymphoproliferative disorders: a clinicopathologic study of 65 cases.

Several clinical and histopathologic features of 65 CD30+ cutaneous lymphoproliferations were evaluated for their diagnostic value between CD30+ primary versus secondary cutaneous lymphomas and for their prognostic significance. Primary cutaneous disease, spontaneous regression, and absence of extracutaneous spreading (but not age < or =60 years) were associated with a better prognosis. Epithelial membrane antigen, BNH9, CD15 or CBF.78 antigen were expressed in all types of cutaneous lymphoproliferations. However, epithelial membrane antigen immunoreactivity was more frequently expressed in CD30+ secondary cutaneous large-cell lymphoma. Among CD30+ primary cutaneous large-cell lymphoma, CD15 expression was only seen in localized skin lesions. P53 expression was not associated with spontaneous regression, extracutaneous spreading, or survival. Nested reverse transcriptase-polymerase chain reaction allowed the detection of NPM-ALK transcripts in 10 of 26 CD30+ primary and in 3 of 11 secondary cutaneous large-cell lymphomas. The ALK protein was detected in only 1 of 50 primary and in 4 of 15 secondary cutaneous CD30+ lymphoproliferations. In CD30+ primary cutaneous lymphoproliferation, NPM-ALK transcripts might be expressed by very rare normal or tumoral cells that are undetectable by immunohistochemistry. However, the expression of either NPM-ALK transcripts or ALK-protein was not correlated with prognosis or age in CD30+ cutaneous lymphoproliferations.

Biomarkers, Tumor↗
PubMed1998

Primary cardiac lymphoma in an immunocompetent woman.

We report a fatal primary cardiac non-Hodgkin's lymphoma in a 62 years old immunocompetent woman presenting with tamponade and complete atrioventricular block. CT-scan, echocardiography and autopsy examination showed a tumor largely infiltrating the heart without extracardiac involvement. A surgical biopsy revealed high grade B-cell non-Hodgkin's lymphoma with a misleading myelomonocytic CD68 (KPI) expression. Polymerase Chain Reaction analysis revealed a clonal rearrangement of the immunoglobulin heavy chain gene and confirmed the B-cell origin of the lymphoma. Our report also emphasizes the role of immunohistochemical and molecular techniques in the diagnosis.

Antigens, CD↗
PubMed1997

Distribution of NGF receptors in normal and pathologic human lymphoid tissues.

To identify nerve growth factor (NGF) target cells in normal and pathologic human lymphoid tissues, we have studied the expression of the low-affinity NGF receptor (p75LNGFR) and the high-affinity tropomyosin-related kinase NGF receptor (TrkA). A RNAse protection assay revealed the expression of trk transcripts in thymus, spleen, palatine tonsils and lymph nodes. TrkA immunoreactivity was shown in thymic epithelial cells, cryptic tonsillar epithelium and several monocyte-derived cells including epithelioid and multinucleated Langhans' cells, follicular dendritic cells and interdigitated reticular cells. TrkA immunoreactivity was rarely observed in normal T- and B-lymphocytes, but was intense in lymphoma cells of several B-cell lymphoma subtypes, anaplastic large cell lymphomas and Reed-Sternberg cells. Western blot analysis revealed the presence of p75LNGFR and of p80Trk and glycosylated Trk isoforms (gp110, gp140). p75LNGFR immunoreactivity was detected in epithelial Hassal's bodies, follicular dendritic cells, interdigitated reticular cells, periarteriolar macrophages, endothelial sinusal cells and nerve endings. The broad expression of NGF receptors may be an indicator of neurotrophin activity in lymphoid tissues and suggests their implication in inflammatory or lymphoproliferative disorders.

Antibodies, Monoclonal↗
PubMed1997

Telomerase activity in human thyroid carcinomas originating from the follicular cells.

Telomerase activity is known to be absent from most normal and well-differentiated tissues, although being detectable in the vast majority of malignant tumors. An increasing number of reports demonstrate that telomerase may be activated in benign tumors, such as adenomas. We have investigated a series of normal and neoplastic thyroid tissues for the presence of telomerase activity. As expected, all normal thyroid tissues (n = 20) had no display of telomerase activity. Amongst cancers, the incidence of telomerase activity varied with the histological subtypes. Telomerase activity was present in only 3/15 cases (20%) of papillary carcinomas. Telomerase activity was more frequently detected in follicular (4/6) and in undifferentiated (2/3) carcinomas. Unexpectedly, one case (1/12) of adenoma contained high levels of telomerase activity. Taken together, these results indicate that telomerase may play some role in the pathogenesis of thyroid tumors, in particular in follicular and undifferentiated carcinomas that are known to have the most aggressive behavior.

Adenocarcinoma, Follicular↗
PubMed1997

Intrasinusoidal bone marrow involvement by splenic lymphoma with villous lymphocytes: a helpful immunohistologic feature.

Splenic lymphoma with villous lymphocytes (SLVL) is a chronic monoclonal B-cell lymphoproliferative disorder characterized by massive splenomegaly and typical villous lymphocytes in the peripheral blood (PB). The diagnosis of SLVL relies on blood smear examination, phenotypic features, and marginal zone involvement of the spleen. The histologic pattern of bone marrow (BM) involvement has not been well characterized. We report four cases associated with a peculiar intrasinusoidal BM involvement. This intrasinusoidal pattern was highlighted by immunostaining that also showed the cytoplasmic projections of villous lymphocytes within routinely fixed and decalcified BM biopsy specimens. Therefore, a simple immunohistochemical analysis of BM involvement would help to identify SLVL. Combined with cytologic and immunophenotypic evaluation of marrow and blood smears, this intravascular pattern might be helpful in differentiating SLVL from hairy cell leukemia and its variant. Whether this peculiar intravascular pattern combined with cytologic evaluation represents a practical alternative to the diagnostic splenectomy must be confirmed by extensive studies focusing on this immunohistochemical criterion.

Aged↗