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PubMed1980

A new technique for the cytochemical examination of human hemopoietic cells grown in agar gel.

In this paper, a new technique for the cytochemical examination of human hemopoietic cells grown in agar gel is described. All colonies in the agar gel in a plastic dish can be observed as a whole plate preparation after being stained cytochemically. Granulocytes and monocytes/macrophages in a cluster or a colony were easily distinguished from each other by esterase activity in response to naphthol AS-D chloroacetate of alpha-naphthyl acetate. To illustrate this technique's possibilities a time course study on the formation of granulocyte and monocyte/macrophage clusters or colonies from normal marrow cells was performed.

Agar↗
PubMed1981

Inhibition of human sperm motility by inhibitors of choline acetyltransferase.

Human spermatozoa contain choline acetyltransferase (ChA), acetylcholinesterase and acetylcholine (ACh). There is no storage pool for ACh in spermatozoa. Therefore, ChA inhibitors should exhibit dramatic effects in the alteration of levels and turnover of ACh and sperm motility. The effects of two groups of ChA inhibitors, 2-benzoylethyltrimethylammonium (BETA) and related compounds and halogenoacetylcholines (cholinesters of iodo-, bromo- and chloroacetic acids; XACh, where X = l, Br or Cl), on the motility index of human ejaculated sperm were studied. These investigations gave the following results: 1) BETA was a potent inhibitor of ChA from monkey brain (I50, 4.8 x 10(-6) M), homogenates of rat spermatozoa (I50, 6.5 x 10(-5) M) and homogenates of human spermatozoa (I50, 5.6 x 10(-5) M). It decreased the motility index of human spermatozoa (I50, 8.5 x 10(-8) M) at concentrations higher than 10(-8) M after a contact time of 5 to 60 min. It decreased the motility index of human spermatozoa by about 80% after 5 min and by 95% after 1 hr at a concentration of 10(-6) M. 2) There was a positive relationship between the inhibition of ChA and the depression of the motility index of human spermatozoa among these inhibitors. Both the number of motile cells and the graded motility were decreased. 3) All ChA inhibitors studied are quaternary ammonium compounds that do not significantly cross membrane barriers. 4) Both human sperm cells and human sperm cell homogenates had the same ChA activity. 5) Seventy-five percent of ChA activity could be washed away from human spermatozoa. 6) The same amount of ChA inhibition was observed when BETA was added to the homogenate of sperm cells or whole sperm cells. All of these observations indicate that sperm cell ChA is accessible to BETA and related quaternary ammonium compounds. These studies indicate that ACh is possibly synthesized by the tail and is a local hormone in the coordination of contraction and relaxation cycles of spermatozoan flagella.

Acetylcholine↗
PubMed1995

[Acute myeloid leukemia (promyelocytic leukemia) with detection of virus particles in a boar. Histologic, histochemical and ultrastructural findings].

Acute myeloid leukemia is a rare finding in swine. A case of acute promyelocytic leukemia is described by light microscopy, enzyme- and immunohistochemistry as well as electron microscopy. Tumour cells can be demonstrated in bone marrow, lymph nodes, liver, spleen, kidneys, small intestine and myocardium. The tumorous neutrophil precursor cells are positive for naphthol-AS-D-chloroacetate esterase and lysozyme. They show ultrastructurally numerous granules as typical for promyelocytes. Virus particles of the oncorna-c-type can be demonstrated within the tumour cells.

Animals↗
PubMed1995

Establishment and characterization of a novel human immature megakaryoblastic leukemia cell line, M-MOK, dependent on fibroblasts for its viability.

A novel fibroblast-dependent human immature megakaryoblastic leukemia cell line (M-MOK) was established from the bone marrow of a girl with acute megakaryoblastic leukemia, and its growth was determined to be completely dependent on the presence of human embryonic lung-derived fibroblasts, HEL-O. Adhesive interaction between M-MOK and HEL-O was crucial for viability; once HEL-O was removed from the culture, mortality was total within a few days. On HEL-O cells, M-MOK could be passaged for more than 2 years. With regard to surface marker profile, the established cells were positive for CD11a, CD13, CD18, CD33, CD34, CD41b, CD42b, CD54, and c-kit antigens, but negative for HLA class II antigen and glycophorin. Histochemically, the cells were negative for myeloperoxidase, nonspecific esterase, and naphthol ASD chloroacetate esterase staining. Electron-microscope examination revealed the cells to be negative for platelet peroxidase (PPO). After induction of differentiation by a phorbol ester, however, the cells were demonstrated to be positive for PPO with a morphological change to megakaryocytes. From these results, M-MOK was considered to represent an immature cell line of megakaryocyte lineage. Studies of the mechanisms sustaining the HEL-O-dependent continuous in vitro growth of M-MOK cells revealed the following results: (1) M-MOK could grow even when separated from HEL-O by a nucleopore membrane; (2) conditioned medium (CM) from HEL-O supported the growth of M-MOK for more than 1 month without feeder cells; (3) the growth of M-MOK on HEL-O or CM supplement was nearly entirely inhibited by anti-GM-CSF (1 microgram/mL); (4) GM-CSF mRNA was detected in HEL-O cells; and (5) HEL-O was found to secrete GM-CSF into the culture medium. Taken together, the growth of M-MOK might therefore be driven by a soluble factor, that is, GM-CSF secreted from HEL-O cells. The presence of HEL-O, however, inhibited anti-GM-CSF-induced M-MOK death. Co-culture of M-MOK and HEL-O cells thus offers a useful experimental model for analysis of interactions between hematopoietic stem cells and stromal cells.

Base Sequence↗
PubMedDate not supplied

Fine needle aspiration cytology of extramedullary chronic myelogenous leukemia.

Chronic myelogenous leukemia (CML) shows extramedullary involvement in 10% of cases. We report the cytologic findings of fine needle aspiration (FNA) of recurrent CML in extramedullary sites in 11 patients with CML. The patients' ages ranged from 24 to 62 years (median, 38 years). There were seven male and four female patients. The aspiration sites were mostly lymph nodes (cervical in 7, retroperitoneal in 2, axillary in 1) and abdominal wall soft tissue (1). The numbers of blasts in the aspirates ranged from 27% to over 90%. Confirmation of the myeloid nature of the blasts was done using naphthol AS-D chloroacetate esterase in one case. Cytologic and flow cytometric immunotyping was done in eight cases. Two cases were based on cytomorphologic features only. Two of the eight immunophenotyped aspirates showed evidence of T-lymphoblastic differentiation. Another showed a mixed myeloid and T-cell phenotype. Blasts were seen in the peripheral blood and bone marrow in 4 of the 11 patients. We thus conclude that extramedullary involvement by CML in our series was associated with younger age, high incidence of cervical lymphadenopathy, increased blasts and frequent lack of bone marrow and peripheral blood involvement. T-cell phenotypes appeared to be higher in our series than reported in the literature. This suggests that there is a need for phenotyping some aspirates of recurrent extramedullary CML, mainly to evaluate the possibility of dedifferentiation and its possible impact on the behavior of the neoplasm.

Adult↗
PubMed1995

Extramedullary myeloid cell tumors. An immunohistochemical study of 29 cases using routinely fixed and processed paraffin-embedded tissue sections.

OBJECTIVE: Extramedullary myeloid cell tumors (EMCTs) may be unsuspected clinically and difficult to recognize histologically. Fresh or frozen tissue is often not available for analysis. We studied 29 cases of EMCT using routinely fixed and processed paraffin-embedded tissue, an immunohistochemical method, and a panel of antibodies. PATIENTS: We studied 29 patients with EMCTs: 22 males and 7 females, with a median age of 48 years (range, 5 to 80 years). Histologically, 9 tumors were well differentiated, 16 were poorly differentiated, and 4 were blastic. RESULTS: The Leder stain (napthol-ASD-chloroacetate esterase) was positive in 21 (77.7%) of 27 tumors. Immunohistochemically, the following antibodies reacted with the greatest number of cases: Leu-22 or MT1 (CD43) in 28 (96.6%) of 29, antilysozyme in 27 (96.4%) of 28, and antimyeloperoxidase (MP07) in 21 (91.3%) of 23 cases. Other myeloid lineage-associated antibodies were positive in a subset of cases: antineutrophil elastase (NP57) in 10 (62.5%) of 16, Leu-M1 (CD15) in 7 (46.6%) of 15, and Mac-387 in 6 (40.0%) of 15 cases. The well-differentiated EMCTs reacted with most myeloid-associated antibodies; poorly differentiated and blastic tumors were more often negative. The pan-leukocyte antibody LCA (CD45RB) reacted with 15 (60%) of 25 neoplasms. Three (16.6%) of 18 tumors contained numerous p53-positive cells, ranging from 10% to 50% of the tumor cell population. In 10 cases, exons 5 through 8 of the p53 gene were analyzed using the polymerase chain reaction and single-stranded conformational polymorphism analysis. Gel shifts consistent with mutations were identified in exon 8 of one tumor (10%) that exhibited abundant p53 immunostaining. CONCLUSIONS: Immunohistochemical studies using fixed, paraffin-embedded sections are very useful in the diagnosis of EMCTs. The most sensitive antibodies are anti-CD43, antilysozyme, and antimyeloperoxidase. Immunohistochemical methods are more sensitive than the Leder stain. We found p53 staining in a small subset of cases, in which we were able to confirm evidence of p53 gene mutation using the polymerase chain reaction and single-stranded conformational polymorphism analysis in one case; p53 gene mutations appear to be uncommon in EMCTs.

Adult↗
PubMed1993

Therapy-related myelodysplastic syndromes: FAB classification, bone marrow histology, and immunohistology in the prognostic assessment.

In this study we describe the morphologic and immunohistochemical evaluation of bone marrow biopsies from 14 patients with therapy-related myelodysplastic syndromes (t-MDS). We employed CD34, anti-HLA-Dr, anti-elastase, CD68, anti-glycophorin, CD61 monoclonal antibodies immunostaining, and enzyme histochemistry for chloroacetate esterase. Moreover, we used PC10, a MAb raised against the proliferating cell nuclear antigen, to study the proliferative capacity of these marrows. Our data suggest that diagnosis of refractory anemia with excess of blasts (versus chronic myelomonocytic leukemia), the abnormal localization of immature precursors, marrow fibrosis, and augmented CD34 expression in the bone marrow biopsy are ominous prognostic factors at a statistically significant level (p < 0.0005). A combined morpho-immunohistochemical analysis of bone marrow biopsy correctly classifies t-MDS cases according to the biologic and clinical aggressiveness.

Antibodies, Monoclonal↗
PubMed1994

Acute promyelocytic leukemia: morphological aspects.

Among AML with maturation, acute promyelocytic leukemia (APL) represents a distinct subtype which accounts for 5-10% of all the FAB variants. APL may be recognized by different cytological pictures: (i) Hypergranular APL, the most typical form, showing promyelocytes with cytoplasm packed with purple granules. Most of the primary granules may be incorporated into Auer rods, sometimes stacked in bundles of faggots. (ii) Microgranular APL, characterized by fine dust-like granulation in the cytoplasm; some promyelocytes may even appear agranular by light microscopy. Most of the cells show bilobed or folded nuclei, a picture which may simulate that of acute myelomonocytic leukemia. (iii) Hyperbasophilic form, characterized by cells with high N/C ratio, and strongly basophilic cytoplasm with either sparse or no granules. Conspicuous cytoplasmatic budding is usually present, recalling the feature of micromegakaryocytes. Strong positivity for myeloperoxidase, Sudan black B and chloroacetate esterase represents the typical cytochemical pattern of M3; usually a weaker reactivity may be observed in M3v. However, sometimes a degree of cytochemical heterogeneity of APL cells may be observed, as suggested by cases displaying a strong sodium fluoride-sensitive nonspecific esterase reaction. Recently a distinct entity associated with basophilic differentiation has been described. Differential diagnosis of this form with M2-baso subtype and with cases of MDS or AML with basophilia (M2, M4 with t(6;9) translocation) may be obtained by the use of cytochemistry, cytogenetic investigations, and electron microscopy.

Carboxylic Ester Hydrolases↗
PubMed1994

Skin involvement in myelogenous leukemia: morphologic and immunophenotypic heterogeneity of skin infiltrates.

A systematic morphological analysis of cutaneous infiltrates in acute myelogenous leukemia and myelodysplastic syndrome revealed that in many cases the infiltrating cells have a different phenotype from those in the bone marrow. This study sought to answer two questions: (a) How wide is the range of cytological features and immunoreactivity of the cutaneous infiltrates and what danger is there of misinterpretation? (b) What are the possible causes of the wide spectrum of differentiation of the cells infiltrating the skin? Skin biopsy specimens from 16 patients with myelogenous leukemia or myelodysplastic syndrome were investigated. The diagnosis was acute myelomonocytic leukemia (M4, according to the French-American-British/FAB system of classification of acute leukemias) in eight cases, acute monocytic leukemia (M5) in four cases, aleukemic leukemia cutis as a recurrence of M2 leukemia after treatment in one case, and myelodysplastic syndrome in three cases, including one case of myelodysplasia with an excess of bone marrow blasts (RAEB-T) and two cases of chronic myelomonocytic leukemia, one of which presented as aleukemic leukemia cutis. Reactivity with the macrophage-associated antibodies anti-CD68, Ki-M1p, and anti-lysozyme was the most consistent. However, the naphthol AS-D chloroacetate esterase reaction and staining with DAKO-M1, Ki-My2p, anti-neutrophil elastase, and anti-CD34 were found to be of little value for identifying the cutaneous infiltrate as myelogenous. Some antibodies (e.g., anti-S100 protein and MB2) even produced staining in a few cases that could have led to a mistaken diagnosis of histiocytic neoplasm or malignant lymphoma.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigen-Presenting Cells↗
PubMed1994

Renal interleukin-1 expression during endotoxemia and gram-negative septicemia in conscious rats.

Endotoxin-induced cytokines such as interleukin-1 (IL-1) and tumor necrosis factor (TNF) are thought to contribute to the proinflammatory effects of endotoxin in gram-negative infections. Using a conscious rat model of sepsis, induced by intravenous challenge with LD95 doses of endotoxin (n = 24) or live Escherichia coli (E. coli) (n = 24), we examined frozen sections of kidney at various intervals for evidence of IL-1 alpha and TNF alpha expression. A transient glomerular endothelial IL-1 alpha expression was demonstrated at 30 and 90 min after initiation of the sepsis in both endotoxin and E. coli-treated animals using immunohistochemistry. The endothelial IL-1 alpha expression as determined by immunohistochemistry occurred at the same time as IL-1 alpha mRNA expression, as determined by Northern blot analysis. The glomerular endothelial IL-1 alpha expression coincided with a slight but significant increase in the number of the glomerular polymorphonuclear leukocytes as identified by naphthol AS-D chloroacetate esterase enzyme histochemical reaction. Glomerular endothelial IL-1 alpha expression was virtually absent by 180 and 360 min. No TNF alpha expression was detected in the renal tissues at any time interval. Neither alpha-naphthyl acetate esterase-positive nor acid phosphatase-positive monocytes/macrophages were identified in the glomeruli. Our findings provide direct in vivo evidence that the IL-1 alpha gene product is expressed locally in the kidney by glomerular endothelial cells in this septic rat model.

Animals↗
PubMed1995

Establishment and characterization of an immature human megakaryoblastic cell line, MEG-A2.

We have established a novel human megakaryoblastic cell line, designated as MEG-A2, from a patient with megakaryoblastic crisis of Philadelphia (Ph) chromosome positive chronic myelogenous leukemia. MEG-A2 cells showed positive phenotypes for periodic acid Schiff and alpha-naphthylbutyrate esterase reactions, but were negative for myeloperoxidase and naphthol ASD chloroacetate esterase reactions. Flow cytometric analyses of cell surface markers revealed that MEG-A2 cells had a low level of GP IIb/IIIa expression as well as apparent expressions of CD4, CD7, CD13, CD33 and CD34 antigens, but no expression of GP Ib nor glycophorin A. Stimulation with phorbol 12-myristate 13-acetate (PMA) dramatically increased the expression of megakaryocyte-related markers such as HPL-3, J15, Pit-1, Y2/51 and AN51 in MEG-A2 cells. The PMA-stimulation also induced expression of platelet peroxidase (PPO) in MEG-A2 cells on electromicroscopic observation. Proliferative responses to granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3) or erythropoietin were observed, and the expression of GP IIb/IIIa was increased by stimulation with GM-CSF, IL-3, erythropoietin and interleukin-6 (IL-6). Protein S mRNA expression was seen in cultured cells on Northern blot analysis. Expression of platelet factor 4 mRNA was induced in PMA-stimulated cells, and a marked accumulation of protein was observed in the culture medium. In conclusion, a new cell line, MEG-A2, belongs to the relatively immature megakaryocytic lineage and has markedly increased megakaryocytic characteristics with PMA stimulation.

Adult↗
PubMed1994

Avian myeloblastic cell lines transformed by two nuclear oncoproteins, P135gag-myb-ets and p61/63myc: a model of retinoic acid-induced differentiation not abrogated by v-erbA.

We previously demonstrated that the retroviral construct MHE226 transducing both the P135gag-myb-ets and p61/63myc nuclear proteins induces solid hemopoietic tumors in early chicken embryos. In the present paper, we report the characterization of two MHE226-transformed cell lines established from such hemopoietic tumors retrieved from the heart of a 13-day embryo. Cytological analysis indicated a myeloblastic phenotype. These MHE226 cell lines were positive for the MEP17 monoclonal antibody but were negative for the myeloblast-specific 51/2 monoclonal antibody. MHE226 cell lines displayed a doubling time of about 20-24 h and were maintained for at least 1 year. Contrary to E26 myeloblastic cell lines, MHE226 cell lines were independent of chicken myelomonocytic growth factor and could be maintained in serum-free medium. MHE226 cell lines could be induced to differentiate toward the monocytic lineage by retinoic acid. Retinoic acid inhibited proliferation of MHE226 cell lines as early as day 1. After 3 days, MHE226 cells displayed cytological, enzymatic (alpha-naphthyl acetate esterase and chloroacetate esterase), and functional (phagocytosis) characteristics of monocytic cells. The retinoic acid-induced differentiation of MHE226 cells could not be inhibited by v-erbA. Thus, MHE226-transformed cell lines represent a novel model of cell transformation by two nuclear oncoproteins. Furthermore, they provide a model to study molecular mechanisms implicated in the monocytic differentiation program.

Animals↗
PubMed1975

The synergistic binding of anions and Fe3+ by transferrin. Implications for the interlocking sites hypothesis.

The finding that transferrin does not bind Fe3+ at the specific metal binding sites in the absence of carbonate and synergistic anions emphasizes the fundamental importance of the anion binding site to the chemistry of Fe3+-transferrin-CO32-. An important question regards the chemical and structural requirements for carbonate substitution. This has been, however, an area of some dispute in the literature. We have utilized four synthetic routes for the preparation of Fe3+-transferrin-anion complexes. The products have been examined with regard to spectral properties, and reaction with: (a) NaHCO3, (b) Fe3+-nitrilotriacetic acid in NaHCO3, and (c) sodium citrate under CO2-free conditions. The results provide information as to which anions are synergistic, and the basic properties of the Fe3+-transferrin-anion complexes that are formed. The 6 inorganic anions that were tested were all found to be nonsynergistic. Dihydroxyacetone and glyceraldehyde were also nonsynergistic. Dicarboxylic acids were found to form stable Fe3+-transferrin-anion complexes which were only slowly displaced by carbonate. Several monocarboxylic acids with proximal aldehyde, ketone, alcohol, amino, or thiol functional groups proved to be synergistic. CPK molecular model studies suggested the functional group and the carboxylic acid must be able to fit within a site between 6.3 and 7.0 A in maximal length. One large substituent could be accommodated by the site, however, two methylgroups on the alpha carbon to a carboxylate group could not be accommodated. Chloroacetate and monocarboxylic acids were nonsynergistic. The results are interpreted in terms of an interlocking sites hypothesis which envisions the synergistic anion as interacting with the protein via its its carboxyl group and bonding with the Fe3+ via its proximal functional group.

Alcohols↗
PubMed1994

Hematopoietic elements associated with adrenal glands. A study of the spectrum of change in nine cases.

We report nine cases of hematopoietic elements or myelolipomatous foci that were found in association with normal and neoplastic adrenal glands. A spectrum of change occurred that ranged from small clusters of purely erythroid or myeloid cells to microscopic myelolipomas that contained a mixture of hematopoietic elements. Recognition of the myeloid elements was facilitated with the use of the chloroacetate esterase (Leder) stain and a CD15 (myelomonocytic antigen) immunohistochemical stain. The majority (six of nine) of these cases were found in association with cortical adenomas in middle-aged women, but myelolipomatous foci were also found in association with an adrenocortical carcinoma, a pheochromocytoma, and a renal angiomyolipoma. The histogenesis of the foci remained speculative. However, the association with hormonally active neoplasms suggested that the hormonal microenvironment may have played a role in the development of the myelolipomatous foci.

Adrenal Gland Neoplasms↗
PubMed1994

Acute promyelocytic leukemia: morphological aspects.

Among AML with maturation, acute promyelocytic leukemia (APL) represents a distinct subtype which accounts for 5-10% of all the FAB variants. APL may be recognized by different cytological pictures: (i) Hypergranular APL, the most typical form, showing promyelocytes with cytoplasm packed with purple granules. Most of the primary granules may be incorporated into Auer rods, sometimes stacked in bundles of faggots. (ii) Microgranular APL, characterized by fine dustlike granulation in the cytoplasm; some promyelocytes may even appear agranular by light microscopy. Most of the cells show bilobed or folded nuclei, a picture which may simulate that of acute myelomonocytic leukemia. (iii) Hyperbasophilic form, characterized by cells with high N/C ratio, and strongly basophilic cytoplasm with either sparse or no granules. Conspicuous cytoplasmatic budding is usually present, recalling the feature of micromegakaryocytes. Strong positivity for myeloperoxidase, Sudan black B and chloroacetate esterase represents the typical cytochemical pattern of M3; usually a weaker reactivity may be observed in M3v. However, sometimes a degree of cytochemical heterogeneity of APL cells may be observed, as suggested by cases displaying a strong sodium fluoride-sensitive non-specific esterase reaction. Recently a distinct entity associated with basophilic differentiation has been described. Differential diagnosis of this form with M2-baso subtype and with cases of MDS or AML with basophilia (M2, M4 with t(6;9) translocation) may be obtained by the use of cytochemistry, cytogenetic investigations, and electron microscopy.

Basophils↗
PubMed1993

Reproductive risks from contaminants in drinking water.

Reproductive toxicity is a complex subject which, besides birth defects or sterility, includes adverse effects which may be less readily observed but more relevant to chronic low-level exposures (e.g., impaired functional development of target organs or systems, secretion of toxic chemicals in maternal milk). Sodium chlorite, when present at high concentration, may be related to impaired reproduction; among water chlorination by-products, further research is required on the developmental toxicity of chloroacetic acid and dichloro- and trichloro acetonitrile. Among the water pollutants which may pose significant developmental hazards, risk assessments have been performed for nitrates/nitrites, fluorides and lead. Molinate (a herbicide), dibromochloropropane (a nematocide) and the halogenated contaminants ethylene dibromide and epichlorohydrin show an almost selective male reproductive toxicity, although they are likely to pose a risk mainly at occupational exposure conditions. Ethylene thiourea, an environmental metabolite of some fungicides is markedly teratogenic in the rat: however, other toxic effects are induced at levels of exposure significantly lower than the teratogenic ones. Such poorly water-soluble compounds as TCDD or hexachlorobenzene also need to be considered, because of their remarkable potentials for reproductive toxicity. Finally, it should be noted that the data on reproductive toxicity for a number of chemicals do not allow a risk assessment at present: this holds true also for some substances which might pose concerns on the basis of their levels in drinking water (e.g. tetrachloroethylene, nickel). Another area which deserves more attention is the investigation of the possible interactions of several contaminants present together at low levels.

Animals↗
PubMed1993

Mast cells in human optic nerve.

PURPOSE: Mast cells are classically found in ocular tissues within the conjunctiva, choroid, and iris. The aim of this study was to examine their distribution in the optic nerve and its meninges. METHODS: Sixty-six human optic nerves were studied from normal subjects at autopsy, fetuses aborted for chromosomal abnormalities, and from enucleation specimens of patients with a variety of inflammatory, traumatic, neoplastic, and vascular disorders. Mast cells were identified using a stain for the enzyme chloroacetate esterase, and confirmed using toluidine blue, revealing metachromatic cytoplasmic granules. RESULTS: Mast cells were found scattered in the meninges of almost all optic nerves examined, frequently in perivascular locations, with densities up to 2325 mast cells/mm3 (mean 269.7 +/- 64.1 cells/mm3 in normal nerves). Mast cells were found in the optic nerve parenchyma in nerves from four eyes that had severe abnormality, often associated with neovascularization. Normal nerves, as well as nerves from fetuses aborted for congenital defects, had significantly fewer meningeal mast cells than those from eyes with inflammatory or vascular diseases. Degranulation of mast cells was observed more often in eyes with recent severe trauma. CONCLUSIONS: Based on their work and the work of others suggesting an association between mast cells and nervous system autoimmune disorders, the authors hypothesize a role for optic nerve mast cells in certain ocular inflammatory conditions.

Adult↗
PubMed1996

Extramedullary myeloid cell tumors arising in the setting of chronic myelomonocytic leukemia. A report of two cases.

We report two cases of extramedullary myeloid cell tumor that arose in patients with chronic myelomonocytic leukemia. In both cases, the tumors were difficult to recognize histologically because the neoplasms lacked cytological evidence of granulocyte maturation, such as cytoplasmic granulation or eosinophilic myelocytes, and the Leder stains for chloroacetate esterase were negative. Immunohistochemical studies were necessary to establish the correct diagnosis. The neoplastic cells in both tumors expressed myeloperoxidase, lysozyme, and CD43 and were negative for B-cell, T-cell, and other nonhematopoietic antigens tested. We report these cases to emphasize that extramedullary myeloid cell tumors may rarely precede transformation to acute myeloid leukemia in patients with chronic myelomonocytic leukemia. Extramedullary myeloid cell tumors of monocytic lineage may be difficult to recognize in routine and Leder-stained sections, and immunohistochemical studies may be essential for establishing the diagnosis.

Aged↗