Biomedical subjects
Publications and source records attributed to D L McLeod.
A 19-year-old man died of a disseminated herpesvirus infection. Microscopic examination of a peritoneal fluid specimen revealed cellular changes characteristic of a herpetic process, and an autopsy confirmed widespread herpes simplex virus type II infection. Viral infections may be diagnosed by cytologic examination of body fluid specimens.
Myeloproliferative disease may be associated with extramedullary hematopoiesis (EH). Clinically, however, the differential diagnosis of solid masses in these patients includes not only EH but also inflammatory lesions and malignant neoplasms, including granulocytic sarcoma. We report the fine-needle aspiration (FNA) cytology of extramedullary hematopoiesis in five patients with a history of myeloproliferative disease. All of the masses developed subsequent to the diagnosis of myeloproliferative disease. Two of the patients had chronic myelogenous leukemia, one had essential thrombocythemia, and two had an unspecified chronic myeloproliferative disorder. The patients ranged in age from 50 to 88 years, and all presented with solid masses involving the kidney (two aspirates), liver (one aspirate), and lymph nodes (three aspirates). One of the lymph node aspirates was from a paratracheal lymph node. Cytologically, the lesions were composed of varying numbers of hematopoietic cells from all three hematologic cell lines. The Diff-Quik stain was especially helpful in the recognition of the hematopoietic cells such as granulocytic precursors, eosinophils, and megakaryocytes. In several cases, the megakaryocytic component was particularly prominent. In one case, the Factor VIII immunoperoxidase stain was used to confirm the megakaryocytic lineage of the multinucleated cells. The cytologic differential diagnosis, which includes granulocytic sarcoma, inflammatory disorders, and other lesions containing multinucleated giant cells, is discussed.
Three spindle cell neoplasms were encountered in a series of 46 FNA of the adrenal performed between 1984 and 1991. These neoplasms included a recurrent undifferentiated adrenal cortical carcinoma (ACC) with a predominant spindle cell pattern, a pheochromocytoma (PC), and a metastatic desmoplastic malignant melanoma (DMM). Cytologically, the ACC was characterized by the presence of numerous microtissue fragments composed of spindle-shaped malignant cells with oval to spindle-shaped nuclei, one or more nucleoli, and bipolar cytoplasmic processes. In some areas the tumor cells were dissected by vascular channels. The background contained abundant metachromatic stroma as well as individually scattered tumor cells. The PC was composed predominantly of loosely cohesive spindle-shaped cells along with more polygonal shaped cells with delicate faintly staining granular cytoplasm. The tumor cells exhibited mild anisonucleosis. The tumor fragments were well vascularized by arborizing delicate capillary channels. The DMM was composed of microtissue fragments, interlacing fascicles and loose aggregates of spindle-shaped malignant cells with hyperchromatic nuclei, small nucleoli, and an absence of cytoplasmic pigment. In each case ancillary studies including immunocytochemistry and electron microscopy (EM) were helpful in the differential diagnosis. The ACC was negative for cytokeratins, neuron-specific enolase (NSE), and muscle-specific actin (HHF), but displayed strong positivity for vimentin as well as characteristic whorls of smooth endoplasmic reticulum by EM. The PC was positive for NSE and chromogranin with no EM performed. The DMM stained for S-100 and vimentin but was negative for HMB-45, cytokeratin, and HHF. EM examination revealed rare atypical premelanosomes.(ABSTRACT TRUNCATED AT 250 WORDS)
We reviewed 130 fine-needle aspiration (FNA) biopsies from 118 patients with a variety of benign and malignant hematopoietic lesions. There were 74 (57%) malignant, 45 (35%) benign, and 11 (8%) atypical diagnoses. Immunocytochemistry of the aspirated material was performed in 47 (36%) and electron microscopy in 4 (3%) of the cases. FNA cytology was utilized to make a primary hematopoietic malignant diagnosis in approximately half of the cases and to confirm recurrence in the remainder. The malignant cases included non-Hodgkin's lymphoma. Hodgkin's disease, medullary and extramedullary plasmacytoma, and granulocytic sarcoma. Forty-two malignant cases had either previous or follow-up surgical biopsy with no false-positive diagnoses. Of the 11 atypical cases, seven had surgical confirmation with five malignant and two benign diagnoses. The benign hematopoietic lesions correctly identified included acute and chronic lymphadenitis, granulomatous processes, and eosinophilic granuloma. Only 5 of the 45 benign FNA biopsies had surgical pathology follow-up, with no false-negative diagnoses. The most commonly aspirated sites were lymph nodes (71%), although hematopoietic lesions were correctly identified in a number of extranodal locations, including soft tissue (8%), abdominal viscera (6%), lungs (5%), mediastinum (2.5%), bone (3%), and thyroid, salivary gland, and breast (1.5% each). This study demonstrates the clinical utility and diagnostic accuracy of FNA cytology in the evaluation of benign and malignant hematopoietic disorders from multiple sites. Ancillary studies performed on the aspirated material aided in making a specific and accurate diagnosis.
Interleukin 3 (IL-3) stimulates several biochemical and biological responses in IL-3-dependent tissue culture cells. We examined the possibility that guanyl nucleotide regulatory (G) proteins may transduce signals from IL-3 receptors. We report here that pertussis toxin (PT), which can covalently modify a subclass of G proteins, is capable of inhibiting IL-3-stimulated proliferation in a dose-dependent fashion. PT inhibition of IL-3-stimulated proliferation could be overcome by using the Ca++ ionophore A23187 in conjunction with TPA. PT could also inhibit IL-3-stimulated hexose transport. In the absence of IL-3, hexose transport could be stimulated by introducing GTP-gamma S into intact cells. From these data we propose that IL-3 receptors transduce signals via a PT-sensitive G protein(s).
We have studied the behavior in culture of circulating restricted hemopoietic progenitor cells from patients with idiopathic myelofibrosis (IMF), polycythemia vera (PV), and essential thrombocytopenia (ET). We have found differences in circulating granulocyte-macrophage, erythroid, and megakaryocytic progenitors that appear to be specific for these chronic myeloproliferative disorders. In IMF, most affected were granulocyte-macrophage progenitor cells (CFU-C), which circulated in increased numbers and were heterogeneous in their sensitivity to the regulatory factor(s) present in phytohemagglutinin (PHA) stimulated T-lymphocyte conditioned medium (CM). Most CFU-C were either highly sensitive to, or independent from, stimulatory factors, while others showed normal sensitivity. In some IMF patients, circulating megakaryocytic progenitors (CFU-M) were present that were capable of giving rise to colonies in the absence of added CM or erythropoietin (EPO). In PV, we confirmed the presence of circulating erythroid progenitor cells that give rise to colonies in culture without the addition of EPO. The number of circulating CFU-C was normal and they responded normally to CM. In ET, failure to detect 7-day circulating restricted progenitor cells was a common observation; the level of other circulating restricted progenitors was in the low normal range. Thus, despite certain common features, including a primary lesion at the level of the pluripotential hemopoietic stem cell, the myeloproliferative disorders differ with respect to the behavior in culture of their circulating restricted progenitor cells. These results have led us to postulate a second regulatory lesion in the pluripotential stem cell that differs in these disorders and is expressed at the level of the respective restricted progenitor cells.
When mouse bone marrow cells are seeded in agar cultures containing erythropoietin or pokeweed mitogen stimulated spleen cell conditioned medium plus erythropoietin, megakaryocytes are found mixed with erythroid cells in approximately 40% of the erythropoietic bursts that develop in the cultures. Chromosome spreads of C-metaphases in such "megaerythro bursts" were prepared and stained in situ with a modification of the C-banding technique. In cultures seeded with mixtures of male and female cells, metaphases from individual megaerythro bursts were shown to be either all male of all female but not both. Moreover, tetraploid C-metaphases of megakaryocytes were found to be of the same sex as diploid C-metaphases of erythroid cells in the same megaerythro burst. These results provide evidence that in the mouse, a bipotential progenitor cell exists that has the capacity to give rise to cells of both the megakaryocytic and the erythrocytic lines of differentiation.
Erythropoietic bursts were produced in plasma cultures seeded with a mixture of male and female murine bone marrow cells. Chromosome spreads of C-metaphases were prepared and stained in situ with a modification of the C-banding technique. In cultures seeded with mixtures of male and female cells, homogeneity of male or female C-metaphases in erythropoietic bursts was established by the presence or absence of the Y-chromosome. These results provide evidence that each erythropoietic burst is a clone, and that the erythropoietic burst-forming unit (BFU-E) is a single cell.
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The sedimentation velocity profiles of the entities in mouse bone marrow responsible for erythropoietic burst formation (BFU-E) and for erythrocytic colony formation (CFU-E) have been studied under conditions designed to determine whether the values observed are real or result from cell interactions occurring during culture of the fractions. Bone marrow cells of adult C3Hf/Bi mice were subjected to unit gravity sedimentation in a bovine serum albumin gradient, and fractions were assayed in plasma culture. Because it was found that cell concentration affected the efficiency of erythropoietic burst formation in culture, aliquots were plated at two different cell concentrations, as well as at a fixed proportion of each fraction. The modal sedimentation velocity of the BFU-E population averaged 3.9 mm/hr and that of the CFU-E population, 6.4 mm/hr; both were found to be independent of cell concentration or method of dividing the fractions. Cells from fractions of different sedimentation velocity were mixed with one another or with unfractionated cells. No significant inhibition or stimulation of erythropoietic burst formation was seen. We concluded that the observed values represented the true modal sedimentation velocities of BFU-E and cfu-e in normal mice. To determine whether a change in the physiologic state of the animals affected the sedimentation velocities of BFU-E or CFU-E, marrow cells from mice hypertransfused with red cells were compared with those from controls. The modal sedimentation velocity of BFU-E was unaffected by hypertransfusion, nor was there any change in the number of BFU-E under these conditions. The number of CFU-E was substantially reduced without a significant change in modal sedimentation velocity.
Erythroid colonies could be produced without the addition of erythropeietin in plasma cultures seeded with bone marrow cells from normal C3Hf/Bi mice by exposure of the cells in vitro to medium from a cell line (IS) that continuously produces Friend leukemia virus in culture. The activity in the culture medium was viral rather than erythropoietin-like, since it was sedimentable by high-speed centrifugation and heat labile. Erythroid colonies did not develop when the bone marrow cells exposed to virus-containing medium were from mice genetically resistant to Friend virus. IS culture medium contained both Friend spleen focus-forming and XC-plaque-forming activities. No erythroid colonies were induced when genetically sensitive cells were exposed to a preparation from which the spleen focus-forming activity had been removed, but which contained XC plaque-forming activity in high concentration. Thus the spleen focus-forming component of Friend virus appeared to be responsible for inducing erythroid colony formation without erythropoietin in vitro. Some erythroid colonies were also found in control cultures to which neither virus nor erythropoietin had been added. Reduction in the concentration of fetal calf serum in the culture medium substantially decreased the number of these colonies but had only a minor effect on the number of virus-induced colonies. The number of erythroid colonies produced after 2 days of culture without erythropoietin or fetal calf serum was approximately proportional to the titer of Friend spleen focus-forming virus to whcih the bone marrow cells had been exposed. This system should prove useful for investigation in vitro of Friend virus--host cell interactions which lead to erythropoietin-independent erythropoiesis.
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A culture method has been developed in which erythroid colonies are produced in vitro from hemopoietic cells from the livers of 13-day fetuses of C3H(f)/Bi mice. Heme synthesis by the cultures was correlated with the presence of these colonies, and the hemoglobin produced was shown to be electrophoretically normal. The individual colonies were identified as erythroid since they were erythropoietin-dependent, positively stained by the histochemical "Lepehne" procedure for hemoglobin, and labeled by (59)Fe radioautography. Evidence is presented that the development of these colonies is under separate control from that of granulocytic colonies found in the same cultures.
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Replication of multipotential stem cells in long-term murine bone marrow cell culture is known to depend on the development of an adherent stromal cell layer. In these conditions, restricted haematopoietic progenitor cells have also been generated for up to several months1-3. However, maturation is observed only in the granulocyte/macrophage and megakaryocyte lineages; erythropoiesis appears to be blocked at the earliest burst-forming unit (BFU-E) stage. Addition of exogenous erythropoietin (Epo) or anaemic mouse serum results in full erythropoietic maturation, but it is transient. We describe here a culture system in which production of erythropoietic progenitor cells can be maintained for over 6 months in the absence of an adherent stromal layer and in the absence of added Epo, but in the presence of pokeweed mitogen-stimulated spleen cell conditioned medium (PWSCM). The data indicate that restricted erythroid progenitor cells exist which are capable of extensive self-renewal.