Human mononuclear phagocyte differentiation: a study of the U-937 cell line by ultrastructural cytochemistry and surface antigen analysis

U-937 represents a well-established permanent human haematopoietic cell line, which exhibits characteristics of the monocyte/macrophage series. U-937 cells were investigated by peroxidase ultrastructural cytochemistry in order to determine the normal developmental stage to which they correspond. This study was performed in non- and TPA-stimulated cells, in conjunction with surface analysis by monoclonal antibodies. It is concluded: (1) peroxidase-positive U-937 cells are monoblasts and promonocytes involved in myeloperoxidase synthesis; (2) TPA-stimulation caricatures transformation of these cells into monocytes but not into resident macrophages, as far as peroxidase cytochemistry is concerned; (3) the reactivity of myeloperoxidase present in the endoplasmic reticulum of synthesizing cells is inhibited by glutaraldehyde fixation.

Mechanism of accessory cell requirement in inducing IL 2 responsiveness by human T4 lymphocytes that generate colonies under PHA stimulation

PHA-driven monoclonal colony formation by low concentrations of resting T4 lymphocytes in agar culture requires the presence of interleukin 2 (IL 2) and accessory cells. Using recombinant IL 2 and anti-Tac monoclonal antibody as a probe for the IL 2 receptor, we demonstrate that the requirement of accessory cells (here an irradiated B cell line) in inducing IL 2 responsiveness relies on their enhancing effect in functional IL 2 receptor expression by the T colony progenitors. Furthermore, it is shown that cell to cell interaction between accessory cells and colony progenitors results in IL 2 response, i.e., colony formation, when the IL 2 receptor density reaches a critical threshold. The asynchronism in IL 2 responsiveness expression by the T colony progenitors upon activation and the short-lived T cell-accessory cell interaction, due to accessory cell death, determine the 10% colony efficiency of the culture system. In addition, we demonstrate that the accessory function in IL 2 receptor and IL 2 responsiveness expression by the T colony progenitors can be supported by irradiated T lymphocytes as well as B cells. The absence of lineage restriction of the signal delivered by accessory cells, and the requirement of physical interaction between T colony progenitors and accessory cells, emphasize the necessity of cross-linking the activation-signal receptors in inducing IL 2 responsiveness by resting T4 cells.

Mechanism of accessory cell requirement in inducing IL 2 responsiveness by human T4 lymphocytes that generate colonies under PHA stimulation

PHA-driven monoclonal colony formation by low concentrations of resting T4 lymphocytes in agar culture requires the presence of interleukin 2 (IL 2) and accessory cells. Using recombinant IL 2 and anti-Tac monoclonal antibody as a probe for the IL 2 receptor, we demonstrate that the requirement of accessory cells (here an irradiated B cell line) in inducing IL 2 responsiveness relies on their enhancing effect in functional IL 2 receptor expression by the T colony progenitors. Furthermore, it is shown that cell to cell interaction between accessory cells and colony progenitors results in IL 2 response, i.e., colony formation, when the IL 2 receptor density reaches a critical threshold. The asynchronism in IL 2 responsiveness expression by the T colony progenitors upon activation and the short-lived T cell-accessory cell interaction, due to accessory cell death, determine the 10% colony efficiency of the culture system. In addition, we demonstrate that the accessory function in IL 2 receptor and IL 2 responsiveness expression by the T colony progenitors can be supported by irradiated T lymphocytes as well as B cells. The absence of lineage restriction of the signal delivered by accessory cells, and the requirement of physical interaction between T colony progenitors and accessory cells, emphasize the necessity of cross-linking the activation-signal receptors in inducing IL 2 responsiveness by resting T4 cells.

Successful treatment of a giant cystic craniopharyngioma. Case report

The Authors present a case of giant cystic craniopharyngioma in a child; the tumor, diagnosed by CT scan, was completely removed. The Authors consider this cyst as the biggest one reported in the literature of the last ten years.

Histopathological lesions of the liver in hairy cell leukemia: a report of 14 cases

Pathological lesions of the liver were studied in 14 cases of hairy cell leukemia, a rare hematologic neoplasm involving numerous organs. Tumor infiltration of hepatic parenchyma was observed in all cases. Tumor cells were easily recognized by their cytological features, namely their "halo" appearance consisting of a clear rim of abundant cytoplasm surrounding uniform round or slightly indented nuclei. Portal infiltration was observed in all cases, associated with sinusoidal infiltration in 12 cases. A peculiar change of the sinusoids, i.e., the angiomatous lesions, was noted in 9 of 14 patients. Angiomatous lesions consisted of intralobular cavities without zonal predominance which were lined by tumor cells which replaced the normal sinusoidal wall and were filled with red blood cells and tumor cells. This pattern of involvement is different from hepatic localization of other blood malignancies and is highly suggestive of hairy, cell leukemia. It might reflect the unique phenotype of the tumor cells, which express lymphocytic and monocytic features. The angiomatous lesion strongly mimics peliosis hepatis and could be, as well as in peliosis, the consequence of modification of the sinusoidal barrier. In hairy cell leukemia, sinusoidal wall abnormalities might be secondary to infiltration of the sinusoids by tumor cells.

Immunoblastic lymphoma involving the bone marrow in a patient with alpha chain disease. Clinical and immunoelectron microscopic study

A patient is reported who had disseminated immunoblastic proliferation that emerged during the course of alpha chain disease. This proliferation was characterized by overt marrow invasion together with osseous and neurologic manifestations. On immunoelectron microscopic study, the malignant immunoblasts displayed varying degrees of cytoplasmic maturation and constituted a morphologic spectrum of alpha-chain-synthesizing cells, ranging from immature blasts without endoplasmic reticulum development to relatively mature plasmablasts; alpha chain was not expressed at the surface of these cells. The general features of the overt malignant stage of alpha chain disease are reviewed in reference to this unusual case. The implications of the cellular findings are discussed with regard to the maturation stage of malignant immunoblasts.

Separation of large quantities of mononuclear cells from human blood using a blood processor

A blood processor (IBM 2991) was used to separate lymphocytes from large volumes of blood. The procedure included the centrifugation of 200 ml whole blood on a density gradient. The results of this procedure were compared with those obtained with a manual procedure. Mononuclear cell (MNC) viability was preserved well in the two methods. But with the processor, recovery of MNC was better (63.5 +/- 2.5%) than with manual separation (26.5 +/- 4.1%). Monoclonal antibodies were used to identify the various cell subsets in the MNC fractions. No particular cell selection was observed when MNC fractions were obtained by the separator. In conclusion, the use of a cell separator provided an efficient technique for rapid isolation of large quantities of lymphocytes.

Heterogeneous accessory cell requirement for human peripheral blood T lymphocyte activation by PHA into IL-2-responsive colony-forming cells

Mitogen-driven T cell proliferation in liquid culture requires accessory cells that cooperate in interleukin 2 production. We have investigated the accessory cell requirement for human lymphocyte colony formation under PHA stimulation. Semisolid medium limits cell-to-cell contact emphasizing the role of cooperating cells both in growth factor production and in triggering events. Culturing at high T cell density demonstrates that accessory cells can be substituted for colony formation by exogenous IL-2. Culturing at low T cell density in the presence of IL-2 also demonstrates that accessory cells are required for activation of a subset of progenitors into IL-2 responsive colony-forming cells. Consequently, T colony progenitors, contained in the E-rosetting cell fraction of peripheral blood, are heterogeneous in their triggering signals: a minor subset is directly inducible by PHA, and a major subset is inducible by PHA in the presence of accessory cells. We found that monocytes and some leukemic B cells support effective accessory function in both colony growth factor production and colony progenitor sensitization.

Phenotype study of fresh and cultured hairy cells with the use of immunologic markers and electron microscopy

The phenotype of fresh and cultured leukemic cells from patients with hairy cell leukemia was studied using a panel of monoclonal antibodies in addition to the detection of peroxidase activity under electron microscopy. In fresh samples, the leukemic cells from 11 patients displayed predominantly a B phenotype, as judged by their reactivity with the B1 monoclonal antibody and surface immunoglobulin expression. Ultrastructural peroxidase activity, characteristic of hairy cells, was observed in all cases studied. When hairy cells were cultured in the presence of phytohemagglutinin and irradiated T cells, their phenotype converted from surface Ig+, B1+, OKT3-, OKT11- to surface Ig-, B1+, OKT3-, OKT11+. In contrast, the peroxidase activity remained unchanged. Some hairy cells were also OKM1+, but no conclusion could be made about the MO2 antigen, a more specific marker of monocytes. The variability of the phenotype in vivo and in vitro indicates that reliable markers are required for identifying hairy cells. When studied together, the staining by B1 monoclonal antibody and the ultrastructural detection of peroxidase, enable the identification of hairy cells with certainty.

Immunological characterization of the leukemic megakaryocytic line at light and electron microscopic levels

Twenty cases of leukemia involving platelet precursors have been identified by a panel of monoclonal and polyclonal antiplatelet antibodies and by the ultrastructural demonstration of platelet peroxidase (PPO). The two techniques were in close agreement both for identification and for the quantitation of the blast cells except in three cases where PPO was present in the absence of the immunological markers. The immunological appearance of the leukemic megakaryocytic precursors was identical to that of their normal counterparts; the cells were positive with J 15 (anti GP IIb-IIIa complex), C 17 (anti GP IIIa), J 2 (anti GP 26,000) AN 51 (anti GP Ib). A diffuse cytoplasmic labelling was observed with anti factor VIII vwF and anti platelet factor 4 (PF 4). In addition, the leukemic maturation was quite similar to normal megakaryocyte differentiation since in micromegakaryocytes the expression of Gp Ib was strong and an intense granular pattern of labelling with anti factor VIII vwF and anti PF 4 was observed. In no case was the leukemic megakaryocytic series labelled by anti-erythroid antibodies, anti myeloid antibodies or J 5, B 1, OKT 11 antibodies. Using ultrastructural immunoferritin with J 15 it was possible to demonstrate that labelling with this antibody only occurred on PPO-positive cells. Immunogold or peroxidase labelling with AN 51 at the EM level in cases of mixed leukemia showed that Gp Ib was absent from proerythroblasts and myeloblasts. Therefore, in no case were specific platelet markers expressed in the leukemias of other cell lineages.

Adult T-cell lymphoma leukemia in Western countries

A new T-cell disorder has recently emerged: the so-called adult T-cell lymphoma leukemia (ATLL) initially described in Japan. Subsequently, ATLL cases were recognized in patients from the Caribbean. We summarize the clinical and hematological features of 19 published cases from Western countries, in addition to a new case we encountered. The leukemic cells display characteristic morphological features and a T3+T4+T8-T6- surface antigenic phenotype. Overall survival is of short duration, but remission could be obtained in our case despite a subsequent relapse in skin and CNS. Geographic clusters of ATLL cases have led to the discovery of the possible role of a new retrovirus, HTLV, in the genesis of this rare malignancy.

Phenotype study with monoclonal antibodies of T lymphocyte colonies in normal individuals and in patients with chronic OKT8+ lymphocytic leukaemia

The lymphocyte colony forming capacity of peripheral blood mononuclear cells from normal controls and from two patients with chronic OKT8+ lymphocytic leukaemia was determined in agar culture under PHA stimulation. The number and size of the colonies in patients were reduced compared to normal. The lymphocytic phenotype of colony cells was studied with monoclonal antibodies in colonies harvested from agar culture and in colonies expanded in liquid culture in the presence of TCGF. This study was performed in individual colonies and in pooled colonies. Colonies from normal controls contained a mixture of the OKT4+ and OKT8+ lymphocyte subsets. In contrast, colonies from the two patients contained essentially OKT4+ lymphocytes. The data indicate that, in the patients, progenitors of the OKT8+ subset are unresponsive to normal proliferative and/or differentiative stimuli under the present culture conditions.

Early response to chemotherapy as a prognostic factor in Hodgkin's disease

In 164 patients with Hodgkin's disease staged between 1973 and 1979 the response to the 3 initial cycles of multiagent chemotherapy was evaluated as a prognosticator of survival. Treatment of localized disease (Stages I, II, III1) consisted of 3 cycles of chemotherapy followed by subtotal nodal irradiation, including the splenic area in non splenectomized patients. Treatment of extended disease (Stage III2 and IV) consisted of 6 cycles followed by low-dosage radiotherapy of initial bulky disease. Five-year actuarial survival was 88% in Stage I, 80% in II, 100% in III1, 45% in III2 and IV. Chemotherapy-induced complete remission after 3 cycles (CH leads to CR) was associated with a favorable prognosis. Five-year survival of Stage III2 and IV patients was better in those who reached CH leads to CR than in those who did not (75% versus 25%; P less than 0.01). This relationship between CH leads to CR and five-year survival was confirmed in patients with localized disease, as shown in Stage II patients (respectively 97% versus 63%; P less than 0.05). Therefore the response to initial chemotherapy provides a new prognostic factor that may serve to delineate a "high-risk" group of patients. The latter deserve aggressive therapy while those in the favorable group would benefit from a less aggressive combined regimen that would minimize long-term complications.

[Multiple myeloma with high tumoral mass. Treatment combining melphalan, cyclophosphamide, vincristine, CCNU and prednisone. 35 cases]

The results of a combination chemotherapy trial (melphalan, CCNU, vincristine, cyclophosphamide) involving 28 patients with stage III (n = 21) or stage II (n = 7) multiple myeloma suggest a high response rate, with a mean 71% malignant cell destruction in 78.5% of the patients. A longer survival in responsive stage III patients as compared with patients treated with alkylating agents seems likely, but this can only be established by a randomized trial. Despite haematological side-effects, this combination therapy may be used in high risk patients, especially those resistant to a single alkylating agent and in whom the frequency, intensity and duration of responses appears to be the same as in previously untreated patients. In contrast, only one of the 7 patients treated for relapse after previous response to a single alkylating agent responded to the combination chemotherapy.

Expression of an accessory cell phenotype by hairy cells during lymphocyte colony formation in agar culture

Human T lymphocytes require the cooperation of accessory cells to generate lymphocyte colonies in agar culture under PHA stimulation. Various hairy cell enriched fractions, as well as normal monocytes, have been found to be able to initiate colony formation by normal lymphocytes. Leukemic monocytes from CMML patients were also effective, but not the leukemic lymphocytes from CLL patients. The phenotype expressed by HC in agar colonies was further studied using cell surface and enzymatic markers. We have concluded that HC in agar culture in the presence of both normal T lymphocytes and PHA lose the B phenotype that they express in vivo and function like an accessory cell in contrast to normal or leukemic B lymphocytes.

Lytic enzyme activity in autolysing mycelium of Aspergillus niger

We have studied changes in the activity of some lytic enzymes contained in mycelium of Aspergillus niger in cultures relative to the autolytic phase of growth. Acid phosphatase, polygalacturonidase and alpha-amylase activity reached its highest level (40.7, and 8 U/sample, respectively) at the initiation of the autolytic phase of growth. 1.3-beta-Glucanase and beta-N-acetylglucosaminidase reached its highest level (3.5 and 2 U/sample, respectively) during the first days of autolysis. Alkaline phosphatase, cellulase, invertase, esterase, chitinase and proteolytic activity is also present in autolysing mycelium of A. niger, though comparatively low. Their maximum activity coincided with the beginning of the autolytic phase of growth. In all enzymes studied here, as autolyis proceeded, enzyme activity decreased by about 90%. Only esterase activity remained nearly constant throughout the whole period of autolysis described here.

Cell wall degradation in the autolysis of filamentous fungi

A systematic study on autolysis of the cell walls of fungi has been made on Neurospora crassa, Botrytis cinerea, Polystictus versicolor, Aspergillus nidulans, Schizophyllum commune, Aspergillus niger, and Mucor mucedo. During autolysis each fungus produces the necessary lytic enzymes for its autodegradation. From autolyzed cultures of each fungus enzymatic precipitates were obtained. The degree of lysis of the cell walls, obtained from non-autolyzed mycelia, was studied by incubating these cell walls with and without a supply of their own lytic enzymes. The degree of lysis increased with the incubation time and generally was higher with a supply of lytic enzymes. Cell walls from mycelia of different ages were obtained. A higher degree of lysis was always found, in young cell walls than in older cell walls, when exogenous lytic enzymes were present. In all the fungi studied, there is lysis of the cell walls during autolysis. This is confirmed by the change of the cell wall structure as well as by the degree of lysis reached by the cell wall and the release of substances, principally glucose and N-acetylglucosamine in the medium.

The ultrastructural localization of immunoglobulins in human b cells of immunoproliferative diseases

The cellular distribution of immunoglobulins in human malignant and normal B cells was investigated by immunoelectron microscopy by direct incubation of fixed cells with electron microscopy by direct incubation of fixed cells with peroxidase-coupled antibody. These conjugates penetrated into the cell, resulting in the simultaneous detection of surface and cytoplasmic immunoglobulins. The latter were seen as specific intracisternal staining of the perinuclear space and endoplasmic reticulum and occasionally of the Golgi complex. Plasma cells were frequently characterized by a heterogeneity of reactivity of the endoplasmic reticulum. Minute amounts of cytoplasmic immunoglobulin were demonstrated in cells without developed secretory organelles, such as lymphoma cells and lymphocytes from chronic lymphocytic leukemia (CLL). The method allowed us to define several subsets of cells according to the expression of surface and cytoplasmic immunoglobulins and thus to determine the stage of maturation of cells involved in monoclonal proliferation.

[Diagnostic value of computed tomography in blood diseases (author's transl)]

Study of a series of 108 patients with blood disease explored by computer tomography showed that this is a reliable method for investigating retroperitoneal lymph node lesions, and that the cost and irradiation level was equivalent to conventional radiological examination. The scanner can also explore the liver, spleen, and lymph node chains, not revealed by the latter. Computer tomography, which is easily accepted by the patient, can be proposed, therefore, for initial and follow-up examinations of these patients.

Detection of surface immunoglobulins of human lymphoid cells: a comparative study of live and fixed cells using a direct immunoperoxidase procedure

Surface immunoglobulins (Ig) of normal and malignant lymphoid cells were detected on prefixed, smeared (method A) and live (method B) cell suspensions; the results were compared with regard to staining patterns, specificity and sensitivity. In both methods surface Ig were detected by a direct immunoperoxidase procedure using conjugated purified antibody. Although method A has practical advantages, method B is more sensitive. The reasons for this discrepancy are discussed in relation to surface Ig denaturation and redistribution.

Myelofibrosis and acute megakaryoblastic leukemia in a child: topographic relationship between fibroblasts and megakaryocytes with an alpha-granule defect

In a child with acute megakaryoblastic leukemia--severe thrombocytopenia and myelofibrosis, EM studies on bone marrow showed a strict topographic relationship between the presence of clusters of abnormal megakaryocytes and the increased number of fibroblasts and extracellular fibers. Megakaryocytes and platelets lacked alpha-granules while the plasma thromboglobulin level was three times the normal level. This suggested that the alpha-granular proteins were synthesized but not retained in alpha-granules. If this occurs, the increased marrow levels of platelet-derived growth factor and factor 4 would favor the proliferation of fibroblasts and the synthesis of collagen, and thereby promote myelofibrosis. After therapy-induced remission, the number of marrow megakaryocytes decreased, the alpha-granules were normally produced, the plasma beta-thromboglobulin level was normal and the myelofibrosis disappeared. These observations suggest that during acute megakaryoblastic leukemia, an acquired gray-platelet syndrome occurs and that the local excretion of alpha-granule proteins triggers the myelofibrosis.

Unusual intracytoplasmic immunoglobulin inclusions in chronic lymphocytic leukaemia

Unusual intracytoplasmic immunoglobulin inclusions were found by immunofluorescence in three patients with chronic lymphocytic leukaemia. The inclusions contained the same immunoglobulin chains as those detected on the plasma membrane, except for delta chains which were expressed on the cell surface and not in the cytoplasmic inclusions. The cytoplasmic staining persisted throughout culture for 8 or more days. An initial study of patients 1's cells showed that the inclusions contained only mu chains, and kappa chains gradually became apparent after in vitro culture. In a second study, the fresh lymphocytes contained both mu and and kappa chains. Initially, biosynthetic experiments showed production of mu chains which polymerized in the cytoplasm and were not secreted. Subsequently there was synthesis of heavy and light chains which assembled into monomeric subunits that were retained and secretion of free light chains. The apparent molecular weight of these immunoglobulin chains was larger than that of their secretory counterparts. Immunoelectronmicroscopy revealed cytoplasmic mu chains in strands of endoplasmic reticulum. In the two other patients, immunofluorescence displayed unusual staining patterns of bright networks in perinuclear areas.

Acute myelodysplasia with myelofibrosis: a report of eight cases

Eight patients with acute myelodysplasia and myelofibrosis are described. Four cases were secondary to long-term therapy with cytotoxic agents and four were idiopathic. All cases presented with an abrupt onset of the illness, absence of organomegaly and severe pancytopenia. Bone marrow aspirate yielded adequate material in four cases and showed myelodysplasic features. Study of histological sections indicated that the bone marrow was cellular in every case, including numerous dystrophic megakaryocytes, erythroblasts, immature cells of the granulocytic series and blast cells which were difficult to identify. The reticulin network was always increased. In each case the disease was rapidly fatal. No improvement was noted with chemotherapy. In three cases an overt leukaemia developed with marked pleomorphism of blast cells. The nosology of this syndrome is discussed.

Detection of J chain in lymphomas and related disorders

Lymph node specimens from 125 patients with malignant lymphomas and related disorders were studied by immunoperoxidase procedure for the presence of intracytoplasmic immunoglobulin (CIg) and J chain CIg staining was present in 22/24 cases of lymphoplasmacytic-lymphoplasmacytoid lymphomas, and in 10/10 cases of extramedullary plasmacytomas and myelomas. In the majority of these cases J chain could be demonstrated in plasmacytoid or neoplastic plasma cells. In 21/36 cases of immunoblastic lymphomas, intracytoplasmic Ig staining was present. In only two of the 36 cases were the lymphomatous cells stained positively for J chain. J chain was not detected in other lymphomas such as lymphocytic lymphomas, follicular lymphomas, lymphoblastic lymphomas or in Reed-Sternberg cells or hairy cells. J chain was demonstrated in mature plasma cells and immunoblastic cells in hyperplastic lymph nodes, and in angioimmunoblastic lymphadenopathy. These findings show that J chain is not detectable in all B cell lymphomas even in the presence of CIg synthesis, irrespective of class.

Acute blast crisis in a patient with chronic lymphocytic leukemia. Immunoperoxidase study

Using a case study of a blastic crisis supervening on chronic lymphocytic leukemia, we were able to determine that the cells in question were B cells derived from the same clone by using immunofluorescence and immunoperoxidase techniques. The immunoperoxidase technique provided excellent morphological details and enhanced the phenotype study.

Primary leiomyosarcoma of bone

A primary tumor of bone, the light microscopic features of which were suggestive of malignant fibrous histiocytoma, proved to be a primary leiomyosarcoma upon electron microscopic examination. Ultrastructurally the tumor cells were smooth muscle cells having all the characteristic features, such as cytoplasmic filaments, cytoplasmic and sarcolemmal dense bodies, and pinocytotic vesicles, with a basal lamina surrounding the cells. This example emphasizes the importance of electron microscopy in diagnostic pathology. This is the second ultrastructural report of a primary leiomyosarcoma of bone.

Immunoperoxidase detection of immunoglobulins in cells of immunoproliferative diseases. A comparison between conjugate and nonconjugate (PAP) procedures

Two immunoperoxidase procedures, direct conjugate and peroxidase-antiperoxidase (PAP) nonconjugate, were compared by studying surface and cytoplasmic immunoglobulins in identical smeared or embedded material from patients having various conditions involving B-cell proliferation. The direct procedure was carried out with affinity-purified antibodies; the PAP procedure was carried out with commercially available antisera and in some experiments by also using purified antibodies as a primary layer. This study confirms the feasibility of both procedures for staining human B cells, although surface immunoglobulins were not visualized in tissue sections. By comparing the phenotypes obtained with both procedures, this study also emphasizes the need for highly specific reagents and the possible shortcoming represented by contaminating specificities present in the first serum layer of the PAP procedure. Diluting primary antiserum was effective in eliminating such unwanted specificities, but at the same time could alter the genuine phenotype of cells. This study emphasizes the need for highly specific reagents such as solid-phase immunoadsorbed antibodies.

Lytic enzymes in the autolysis of Schizophyllum commune with special reference to 1,3-alpha-glucanase

In the autolytic phase of growth Schizophyllum commune lost 62% of its dry weight in 70 days of incubation. The variations in the activity of some lytic enzymes were studied in the culture fluid and mycelial extracts during growth and autolysis of this fungus. The enzymes 1,3-beta-glucanase (exoglucanase), 1,3(4)-beta-glucanase (endoglucanase), alpha-amylase, and invertase behaved in the same way in culture fluid and mycelial extract, but their activities were much higher in the culture fluid. The enzyme activities increased during autolysis, but then decreased at the end of this period except in the case of alpha-amylase which remained high. It was only possible to detect 1,6-beta-glucanase, cellulase, and polygalacturonase activities at certain times during the autolytic phase of growth. The enzyme chitinase was not detected and 1,3-alpha-glucanase (S-glucanase) occurred in the mycelial extract at a higher concentration than in the culture fluid. A decrease in the activity of this enzyme in the mycelial extract and an increase in the culture fluid occurred during autolysis. The enzyme 1,3-alpha-glucanase exhibited two optima pH, one at 6.0 and the other at 8.0. The Km value for the latter was 0.02 M at pH 5.5 in borate-citrate-phosphate buffer.

Acute non myeloid leukaemia in adults. Prognostic factors in 92 patients

An analysis of prognostic factors was performed on a series of 92 adult patients with acute non-myeloid leukaemia (ANML). Four factors were shown to be correlated with a poor short-term prognosis: (1) Neuropathy involving a single cranial nerve (numbness of the chin) as a presenting feature. (2) A low percentage blast cell infiltration of bone marrow (less than 55%). (3) Cytological L2 type or L3 type of cells according to FAB classification proposals. (4) Increased age. Two factors were shown to be correlated with a poor long-term prognosis: 1) A high level of circulating blast cells; 2) A high tumour burden, as in childhood ANML. These two long-term prognostic factors were interrelated. In addition, our results suggested that myelofibrosis could be a poor long-term prognosis factor as well.

[Malignant myelofibrosis. One case (author's transl)]

In a 75-year-old man, the rapid development of a pancytopenia as a result to total marrow failure, in the absence of tumour or extramedullary myelopoiesis, but with a histological appearance of the marrow identical to that seen in agnogenic myeloid metaplasia led to a diagnosis of malignant myelofibrosis. The patient died 7 months after the apparent onset of the disease. The 48 other published cases are discussed. Only 17 are considered to be true cases of malignant myelofibrosis.

Failure of naloxone to alter growth hormone and prolactin levels in acromegalic and in hyperprolactinaemic patients

We examined the effects of high-dose intravenous naloxone administration in four acromegalic patients (mean serum growth hormone level 72 ng/ml) and in seven hyperprolactinaemic women (mean serum prolactin level 59 ng/ml), in order to assess whether this opiate antagonist would be effective in lowering growth hormone and prolactin levels. No effect was observed. This lack of effect suggests that an opioid pathway is not involved in the maintenance of elevated growth hormone or prolactin secretion in these patients. However, conclusions regarding the possible role of endogenous opioids in regulation of pituitary function in normal individuals cannot be drawn from this study.

Immunoelectron microscopy and immunocytochemistry in pathology, with special reference to immunoglobulin-producing cells

The advantage of immunoelectron microscopy (immuno-EM) is that it allows the simultaneous detection of surface and internal cell components. The immunoperoxidase method is often more suitable than immunoferritin. There are no major difficulties in staining surface antigens by immuno-EM, provided sufficient amounts of pure antibodies are available for coupling to peroxidase. Prior fixation of cells, with faxatives that preserve the antigenicity of surface components, avoids ligand-induced alterations of the surface components. It is believed that, unlike the surface, intracellular antigens are difficult to stain by immuno-EM because of the poor penetration of conjugates into fixed cells; thus, various technical approaches have been proposed by workers involved in tissue immuno-EM. In fact, the method that we initially devised for the surface staining of fixed cell suspensions has proved to detect specifically intracellular immunoglobulins in B cells obtained from patients with proliferative diseases. Thus, conjugates do penetrate into fixed cells, although by an unknown mechanism. On this basis, it is possible to study both surface and intracellular immunoglobulins at the EM level and to determine the precise localization synthesis.

Synthesis of a peroxidase activity by the cells of hairy cell leukemia: a study by ultrastructural cytochemistry

The nature of cells present in the blood, marrow, and spleen of patients with hairy cell leukemia is largely debated. These cells have been tentatively categorized on the basis of either monocytic or lymphocytic markers, and the accumulating data points to the fact that they share some characteristics of both cell types. Although hairy cells are known to lack myeloperoxidase-positive granules, present in normal human monocytes, we investigated the possible presence of other peroxidase activities differing from the granule-bound myeloperoxidase. The study was carried out with several methods based on the incubation of fixed and unfixed cells in the presence of diaminobenzidine and hydrogen peroxide. A peroxidase activity was found in hairy cells, located always in the endoplasmic reticulum but not in the Golgi apparatus or in any granule. By its cytochemical characteristics it appears to be closely related to that of tissue macrophages, activated blood monocytes, and other nonlymphocytic hematopoietic cells. This peroxidase is not found in lymphocytes with B or T phenotypes.

The blast crisis of chronic granulocytic leukaemia: megakaryoblastic nature of cells as revealed by the presence of platelet-peroxidase--a cytochemical ultrastructural study

The origin of cells in the blast crisis of some cases of chronic granulocytic leukaemia (CGL) remains controversial. Difficulties arise from the lack of cytochemical characteristics of differentiation. This report concerns the nature of cells in the blast crisis of a case of CGL in which blast cells exhibited an undifferentiated or lymphoid appearance by light and electron microscopy. The majority (90%) of such cells contained a peroxidase in the endoplasmic reticulum distinct from myeloperoxidase. In addition, some micromegakaryocytes could be recognized among the peroxidase reactive cells, by the presence of typical granules and demarcation membranes. Since this peroxidase exhibited identical characteristics to that of normal megakaryocytic precursors, these blast cells could be identified as megakaryoblasts. These data emphasize the possible megakaryoblastic nature of cells occurring in other cases of CGL blast crisis.

Binding of antibodies to acetylcholine receptors in Electrophorus and Torpedo electroplax membranes

Antisera against purified acetylcholine receptors from the electric tissues of Torpedo californica and of Electrophorus electricus were raised in rabbits. The antisera contain antibodies which bind to both autologous and heterologous receptors in solution as shown by an immunoprecipitation assay. Antibodies in both types of antisera bind specifically to the postjunctional membrane on the innervated surface of the intact electroplax from Electrophorus electric tissue as demonstrated by an indirect immunohistochemical procedure using horseradish peroxidase conjugated to anti-rabbit IgG. Only anti-Electrophorus receptor antisera, however, cause inhibition of the receptor-mediated depolarization of the intact Electrophorus electroplax. The lack of inhibition by anti-Torpedo receptor antibodies, which do bind, suggests that the receptor does not undergo extensive movement during activity. The binding of anti-Torpedo antibodies to receptor-rich vesicles prepared by subcellular fractionation of Torpedo electric tissue was demonstrated by both direct and indirect immunohistochemical methods using ferritin conjugates. These vesicles can be conveniently collected and prepared for electron microscopy on Millipore filters, a procedure requiring only 25 micrograms of membrane protein per filter. In addition, it was possible to visualize the binding of anti-Torpedo receptor antibodies directly, without ferritin. These anti-Torpedo receptor antibodies, however, do not inhibit the binding of acetylcholine or of alpha-neurotoxin to receptor in Torpedo microsacs but do inhibit binding of alpha-neurotoxin to Torpedo receptor in Triton X-100 solution. It is likely that the principal antigenic determinants on receptor are at sites other than the acetylcholine-binding sites and that inhibition of receptor function, when it occurs, may be due to a stabilization by antibody binding of an inactive conformational state.