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Biomedical subjects

B Caillou

Publications and source records attributed to B Caillou.

At least 109 records · Page 6Linked to original sources
PubMed1986

Ectopic hematopoiesis in peritoneal tumor nodules induced by the myeloproliferative sarcoma virus in DBA/2 mice.

Tumor nodules composed of fibroblasts, large undifferentiated cells, granulocytes, and small lymphocytes develop in the spleens of adult DBA/2 mice infected with the myeloproliferative sarcoma virus (MPSV). They spread thereafter in the organism, and at the terminal stage of the disease they are especially numerous on the peritoneal membrane. The present study, performed on those tumor nodules to avoid contamination by exogenous hematopoietic cells, demonstrated that they were sites of granulopoiesis, which may have occurred via the local differentiation of granulomacrophage precursor cells (GM-CFC) and perhaps also from pluripotent hematopoietic stem cells, since these two populations were present in the tumor nodules (25 +/- 11 and 13 +/- 10, respectively, per 5-10(5) cells). Almost all (88%) those GM-CFC were able to clone in vitro without added colony-stimulating factor. A comparative study with the Moloney murine sarcoma virus-induced tumor indicated that the local production of hematopoiesis-stimulating factors was not sufficient to allow such ectopic granulopoiesis. These results imply the presence of a specific hematopoietic microenvironment in the MPSV-induced tumor nodules.

Animals↗
PubMed1986

Phenotypic characterization of the thymus microenvironment study of the human thymus architecture.

Phenotypic characterization of the human thymic microenvironment shows the heterogeneity of the epithelial component. Using monoclonal antibody L191, we define here a new antigen common to the flat epithelial cells lining up the thymic capsule and septum, stellate epithelial cells from the subcapsular area and the medulla (M), but lacking on stellate epithelial cells from the inner cortex. Thus, this cell population can be characterized by a series of antigens (TE-4 and P19--shared with HTLV--previously described by B. Haynes et al.) which reflect a common differentiation program--including neuroendocrine specialization--with remarkable differences in the expression of these antigens, occurring during ontogeny and after birth. Another Ab we obtained shows particularities in the cytoskeletal organization of this cell population. Finally the organization of the mesenchymal component was also investigated with a third, anticollagen, antibody. A striking observation we made, using these antibodies, was the relationship between the thymic septum and flat epithelial cells with medullary and Hassal's body (HB) epithelial cells: septae deeply penetrate the medulla so that flat epithelial cells come into direct contact with medullary epithelial cells; in addition, HB are in close contact with the deepest portion of the septae, often separated solely by a single stellate cell. This architectural organization might be related to the differentiation--regeneration process of the thymic epithelium.

Antibodies, Monoclonal↗
PubMed1985

Long-term results and prognostic factors in patients with differentiated thyroid carcinoma.

A multivariate analysis of the prognostic factors was carried out on a series of 546 differentiated thyroid cancers followed for 8 to 40 years. For survival, the highest risk factor was associated with age; tumors diagnosed in patients younger than 45 years had higher relapse-free survival (RFS) and total survival (TS) rates and a slower growth rate. In children, although the RFS and TS at 15 years were high, they decreased later. The second independent prognostic factor was histology. There was no difference between papillary and follicular well-differentiated (FWD) tumors, but follicular moderately differentiated (FMD) had lower TS and RFS. Among FMD cancers, relapses occurred earlier and the interval between relapse and death was shorter. The third factor was sex. Tumors tended to disseminate more in male than in female patients. The survival rate after relapse was the same, however, suggesting that the growth rates are not different. The presence of palpable lymph nodes also had a significant independent impact on both TS and RFS. Patients treated after 1960 have a better outcome than patients treated earlier, although they did not differ in age distribution, histologic characteristics, sex ratio, or incidence of palpable lymph nodes. The distribution of time intervals between treatment and relapse was not compatible with an exponential failure time model but fit with a log-logistic model. Relapses can occur as late as 30 years or more after initial treatment. Elevated levels of circulating thyroglobulin have been observed in about 12% of the patients who had been in complete remission for longer than 20 years.

Adolescent↗
PubMed1985

Reproducibility and prognostic value of different non-Hodgkin's lymphoma classifications: study based on the clinicopathologic relations found in the EORTC trial (20751).

In the EORTC trial 20751, six pathologists belonging to five different centers classified tumoral lymph nodes from 406 untreated patients with non-Hodgkin's lymphoma (NHL) into three different NHL classifications. NHL were most easily and reliably subdivided according to the growth pattern (the rate of consensus being 93%). Classification according to growth pattern proved to be of prognostic significance. The rate of consensus of classifying cases in the different NHL classifications ranged from 74% for the Rappaport, through 70% for the Kiel to 67% for the international working formulation. It is concluded that NHL are reliably classified according to their growth pattern, and that this subdivision is of primary prognostic significance.

Humans↗
PubMed1985

Fine structural localization of acetylcholinesterase activity in rat submandibular gland.

Using the indirect thiocholine method, the ultrastructural localization of acetylcholinesterase (AChE) activity in the normal rat submandibular gland was studied. Cytochemical demonstration of AChE is based on coupling the hydrolysis of acetylthiocholine iodide to the precipitation of heavy metal salts. AChE-associated reaction product was selectively revealed in the perinuclear space and in the endoplasmic reticulum of the intercalated duct cells, in some cells of granular convoluted tubules, and in the striated duct epithelium, as well as in the myoepithelial cells. Although AChE activity generally occurred inside the cells, electron-dense precipitates were shown in intercellular space and in the stroma of the gland. Fine localization of AChE activity was also found in nerve bundles, predominantly between axons and between axons and Schwann cell. Our observations indicate that AChE is synthesized in the epithelium of the ducts and in the myoepithelial cells of the salivary gland. It is not known yet whether this enzyme is released from the intracytoplasmic membrane system into the extracellular space and then transported to the regions of the gland innervation. Conceivably AChE synthesized in the submandibular gland cells could also be considered an inhibitory modulator of the regulatory functions of biologically active polypeptides.

Acetylcholinesterase↗
PubMed1985

Acetylcholinesterase in human thymus cells.

Acetylcholinesterase (AChE) was long thought to be an enzyme found specifically at the sites of nerve synapses and neuromuscular junctions. It has also been found to occur, however, in cells that are not involved with neurotransmission. This study presents the ultrastructural localization of AChE activity in human thymus cells, using the indirect thiocholine method. Cytochemical demonstration of the enzyme was based on the coupling of acetylthiocholine iodide hydrolysis to the precipitation of heavy metal salts. AChE activity was selectively revealed in the perinuclear cisternae, within the endoplasmic reticulum, and in the Golgi complex of thymic lymphocytes and epithelial cells. Evidence of the presence of reaction product in the latter cells was also found in vesicles that opened into the extracellular space. This is the first demonstration of AChE in human thymus cells. Its possible physiologic role in the thymus gland is discussed.

Acetylcholinesterase↗
PubMed1985

[A case of Torre's syndrome: association of a meibomian adenocarcinoma with a cecal tumor].

The authors report a case of sebaceous adenocarcinoma of the eyelid developed in meibomian glands. This tumor grew slowly for several years and was diagnosed three years after an intestinal adenocarcinoma was discovered in the same patient. This case is part of a Torre's syndrome (association of a sebaceous neoplasm and a visceral malignancy). Such an association represents an original example of multiple tumors and shows that the discovery of a sebaceous tumor, benign or malignant, indicates a careful search of an internal malignancy.

Adenocarcinoma↗
PubMed1984

[Value of immunohistochemistry in the study of medullary cancer of the thyroid. Implications of the results for the concept of the APUD system and of apudomas].

Immunohistochemical studies in medullary thyroid carcinoma demonstrate the presence of C cells secreting calcitonin but also of other cells secreting other peptides or proteins. These different cells exist in the tumor as well as in metastases. These results and other reported in the literature suggest a common ultimobranchial and endodermal origin for these cells.

APUD Cells↗
PubMed1984

[Multiple endocrine neoplasia type 2b. Clinical, diagnostic and therapeutic aspects].

Multiple Endocrine Neoplasia type 2b (MEN 2b) is a rare syndrome. The principal features are: medullary thyroid carcinoma (MTC), dysmorphism, a ganglioneuromatosis and pheochromocytomas. Eight cases of MEN 2b have been observed at the Institute Gustave Roussy, between 1968 and 1983. Seven involved children under 15 years of age. Eight had a bilateral MTC; six had dysmorphism; six had mucosal tongue neuromas. Six were troubled with visceral ganglioneuromatosis of whom two had intestinal obstruction and one urinary chronic retention. One patient had pheochromocytoma with hypertension. From this experience and other data it appears that: the dysmorphism is frequently poorly interpreted; the visceral ganglioneuromatosis is an early and severe feature; it is important to examine the patient for pheochromocytoma; the MTC must be detected by calcitonin dosage after stimulation, and requires total thyroidectomy; familial screening must be done. To improve the poor prognosis of MEN 2b, early diagnosis and aggressive treatment are necessary.

Adolescent↗
PubMed1984

[Immunoscintigraphy with emission tomography in cancers of the thyroid].

Immunoscintigraphy (IS) consists of in vivo body structure imaging using a specific labelled antibody to an antigen concentrated in the structure under study. Technically, the image contrast is better when IS is performed with a computerized emission tomography system. High concentrations of carcinoembryonic antigen (CEA) have been reported in medullary thyroid carcinoma and thyroglobulin (Tg) is a marker for differentiated thyroid carcinoma. We used injections of 131-I labelled monoclonal antibodies to CEA and Tg to detect thyroid tumours. A feasibility trial using anti-CEA antibodies gave very encouraging results. However, only tumours larger than 10 cm3 could be detected. Contradictory results were obtained using anti-Tg antibodies but this data must be considered as preliminary. Various means of improving the method and the concept of accessibility of the antigen to the antibody in vivo are discussed. This study shows IS to be a promising experimental technique. Further studies are required to define its clinical indications before it can be advocated for routine use.

Animals↗
PubMed1984

[Immunohistochemical and ultrastructural studies of thyroid cancer].

The results of immunohistochemical and ultrastructural studies have improved our understanding and provide a better method of classifying thyroid carcinoma. These techniques have also enabled identification of tumours with composite cell populations. These tumours pose clinical, diagnostic and therapeutic problems, and pose fundamental questions such as the relationship between vesicular and C cells. In addition, these techniques are the only available method of determining in situ within the tumour tissue the exact location of different antigens. This information may contribute to the study of the function of the molecules in question and of their accessibility to antibodies in vitro or in vivo.

Fluorescent Antibody Technique↗
PubMed1984

A novel human leukocyte differentiation antigen: monoclonal antibody anti-D44 defines a 28 Kd molecule present on immature hematologic cells and a subpopulation of mature T cells.

Anti-D44 is a cytotoxic IgG2b monoclonal antibody (MAb), which reacts with two polypeptides of 28 and 30 Kd from human peripheral T cells after western blotting. The antigen is present in low density on bone marrow cells from the myeloid lineage, probably including most CFU-GM; the antigen is present on megakaryocytes but is not detectable on erythroid cells as well as pre-B and B cells. Growth of BFU-E appears to be partially inhibited after treatment with anti-D44 + complement, an effect that should be due to bone marrow T cells rather than to BFU-E destruction. With maturation, the antigen is barely detectable on mature polymorphonuclear neutrophils, and is not detectable on platelets and monocytes. In contrast, cells from the thymic cortex carry a high density of this molecule; medullary thymocytes carry a low density. Large thymocytes ("thymoblasts") distinct from epithelial or interdigitating cells also bear a high density of the antigen. In the periphery, a subpopulation of T cells displays a high density of D44 molecules. D44 antigenic density is not linked to cell growth or to T cell activation. Double labeling and cell sorting experiments have shown that 40% of E rosette-forming cells are D44(+)-CD4+, 10% are CD8(+)-D44+ and 10% are CD4(-)+CD8-, CD2+. In an accompanying report, correlation is shown between expression of the D44 defined molecule on T cell subpopulations and the function they exert. Immunoperoxidase studies of skin, brain, and kidney tissues, facilitated by the fact that the antigen is resistant to inclusion in Epon, which permits staining of semi-thin sections, have not revealed any positive nonhematologic cell.

Animals↗
PubMed1984

Effect of alkylating agents on hematopoiesis in myelofibrosis. 4 case report.

Four patients presenting with myelofibrosis (2 primary myelofibrosis and 2 postpolycythemic myeloid metaplasia) were treated with alkylating agents. For three patients (one treated with busulfan and two treated with chlorambucil) the treatment was a success: the general condition improved, the splenomegaly decreased or disappeared, and the blood picture returned to normal. Moreover, for two cases, a trend towards polycythemia was observed under treatment. For the fourth patient, treated with chlorambucil, there was no improvement: a life-threatening, pancytopenic phase developed at the end of the treatment, but it disappeared after 2 months. For the three successfully treated cases, a redistribution of hematopoiesis from spleen to bone marrow was shown by ferrokinetics, 59Fe scans, and bone marrow biopsies. In addition, in the case treated with busulfan, a decrease in the bone marrow granulopoietic pool at the expense of the erythropoietic one was observed. No redistribution was seen in the patient for whom the treatment was a failure. In this case, the spleen remained the major site of active hematopoiesis. Studies on blood granulomonocytic-colony forming cells (GM-CFC's) helped to discriminate the successfully treated patients from the unsuccessfully treated one. In the successfully treated patients, the GM-CFC concentrations dropped to normal values and increased again within weeks following the treatment interruption; this increase involved mainly high density GM-CFC's (greater than 1.060). In the unsuccessfully treated patient, GM-CFC concentrations decreased only after 5 weeks of intensive treatment. The mean density of the GM-CFC's was 1.064 before treatment, shifted towards 1.060 during the neutropenic phase and returned to 1.064 during the recovery.

Alkylating Agents↗
PubMed1984

[Soft tissue clear cell sarcomas. Reevaluation of clear cell sarcomas of the tendons and the aponeuroses in 14 cases].

A retrospective study is realized including 14 cases of clear cell sarcomas of tendons and aponeuroses, found in the files of Institut Gustave-Roussy (1969-1983). The main microscopic features are emphasized. In comparison with other soft tissue sarcomas, clear cell sarcomas are clinically characterized by a great frequency of local lymph node metastases (4 of 14 cases). The prognosis is usually particularly poor. The exact histogenesis remains obscure, but the results of special stains, support origin from migrated neural crest cells: melanin is visualized in 2 out of 12 tumors in which Fontana-Masson is performed. S 100 protein, a neuroectodermal marker, is positive by immunoperoxidase technique (PAP) in 6 of 10 tested cases. A better diagnostic approach is allowed with the help of ultrastructural study performed in 3 cases. These tumors must be separated from synovialosarcomas. Because the histogenesis is not actually sure, it is preferable to call them "soft tissue clear cell sarcomas".

Adolescent↗