Enzyme immunoassay for tartrate-resistant acid phosphatase

An immunochemical method for quantitative analysis of the tartrate-resistant acid phosphatase (EC 3.1.3.2), band 5, is presented. This method involves precipitation of the enzyme from the serum by the antibody specific to band 5 and by sheep anti-rabbit immunoglobulin, followed by analysis of the enzyme activity in the precipitate. The precipitation procedure eliminates the interferences of the tartrate-sensitive phosphatase of all tissues, of the tartrate-resistant phosphatase of erythrocytes, and of unknown substances that interfere with the colorimetric method. We compare the present method with previously described colorimetric and electrophoretic methods.

Enzyme immunoassay for tartrate-resistant acid phosphatase

An immunochemical method for quantitative analysis of the tartrate-resistant acid phosphatase (EC 3.1.3.2), band 5, is presented. This method involves precipitation of the enzyme from the serum by the antibody specific to band 5 and by sheep anti-rabbit immunoglobulin, followed by analysis of the enzyme activity in the precipitate. The precipitation procedure eliminates the interferences of the tartrate-sensitive phosphatase of all tissues, of the tartrate-resistant phosphatase of erythrocytes, and of unknown substances that interfere with the colorimetric method. We compare the present method with previously described colorimetric and electrophoretic methods.

Systemic mast cell disease: a clinical and hematopathologic study of 26 cases

Systemic mast cells disease (SMCD) is an uncommon disorder that constitutes approximately 10% of all mastocytoses. Diagnosis requires a substantial degree of clinical suspicion, which may not be present if characteristic skin lesions of urticaria pigmentosa are not observed. Lack of well-defined histopathologic features for the disease have delayed or prevented the diagnosis of SMCD. An initial diagnosis of "myeloproliferative disorder," chronic granulocytic leukemia, or myelofibrosis is frequently made. Study of the clinical and pathologic features of 26 cases of SMCD indicated that affected patients are generally middle aged and may have had urticaria pigmentosa for many years. Gastrointestinal symptoms are common, and splenomegaly and hepatomegaly along with radiographic evidence of generalized bone disease are usually noted. Hematologic factors are highly variable. Characteristic histopathologic features of SMCD are described for bone marrow, lymph nodes, liver, and spleen. The authors consider tissue fixation and staining methods to help identify mast cell lesions.

Immunoperoxidase staining of bone marrow sections

Paraffin-embedded sections of bone marrow from 131 patients were studied. The specificity of the immunoperoxidase technique for detecting intracellular kappa and lambda light chains of immunoglobulin was first evaluated in 34 cases of typical multiple myeloma or macroglobulinemia. The monoclonal light chain detected in the bone marrow myeloma was identical to the result of immunoelectrophoresis of serum or urine. By use of the same method, 97 cases in which the diagnosis was difficult were examined; cases included those of bone marrow plasmacytosis, lymphocytosis, and morphologically unusual cells. All marrow cells with monoclonal immunoglobulin detected by immunoperoxidase stain eventually proved to be a B-cell neoplastic or potentially neoplastic process. This study confirms the specificity of the immunoperoxidase stain and demonstrates its value in solving clinical diagnostic problems, that is, the diagnosis of nonsecretory myeloma and unusual morphology, differentiating the monoclonal plasmaproliferative disorders from reactive plasmacytosis or lymphoma from lymphocytosis.

Comparison of the tartrate-resistant acid phosphatase in Gaucher's disease and leukemic reticuloendotheliosis

Tartrate-resistant acid phosphatase was isolated from serum and spleen of patients affected by Gaucher's disease. Electrophoretic and antigenic properties were compared to the enzyme isolated from hairy cells described in a previous study (9). The enzyme isolated from Gaucher serum has electrophoretic and antigenic properties identical to the acid phosphatase band 5b of hairy cells. The major tartrate-resistant acid phosphatase in the Gaucher spleen is band 5a. Bands 5a and 5b have identical protein structure indicated by their identical antigenicity. The removal of carbohydrate from band 5a by sialidase converted band 5a to 5b.

Presence of "prostatic" acid phosphatase in human neutrophils

The occurrence of natural substances with antigenic properties similar to those of the prostatic acid phosphatase was examined in one patient with neutrophilic leukemia and increased activity of serum acid phosphatase. The fraction responsible for the increased serum enzyme activity was tartrate sensitive and was identified as isoenzyme 2 by polyacrylamide gel electrophoresis. This isoenzyme originated from the leukocytes but had similar electromobility to that of the prostatic acid phosphatase isoenzyme 2. Immunohistochemical and counterimmunoelectrophoretic studies indicated that this leukocytic isoenzyme was present in the neutrophils and shared antigenic properties with the prostatic isoenzyme 2. Leukocytes from one patient with acute granulocytic leukemia, two patients with polycythemia vera with neutrophilia, and five normal subjects also contained this prostatic acid phosphatase like isoenzyme. Elevated serum "prostatic" acid phosphatase activity, therefore, may be found not only in prostatic cancer but also in granulocytic leukemia and perhaps other diseases.

A simple immunohistochemical method for the detection of prostatic acid phosphatase

A simplified immunohistochemical method was developed to identify prostatic cells in paraffin sections for the diagnosis of primary or metastatic prostatic carcinoma. By incubating each section with a specific antiserum, followed by incubation with a specific acid phosphatase isoenzyme of the prostate, the antibody binding site is visualized by staining for acid phosphatase activity in the glandular epithelial cells of the prostate and in the metastatic prostate carcinoma cells that involve the lymph node. The present method is simpler and more specific than the previously described indirect immunoperoxidase method.

Localization of the B and M polypeptide subunits of creatine kinase in normal and neoplastic human tissues by an immunoperoxidase technic

Measurements of the BB isoenzyme of creatine kinase in serum may be useful in the diagnosis or monitoring of patients who have some types of cancer, and the distribution of creatine kinase isoenzymes in homogenates of certain sarcomas has been evaluated as an aid in the morphologic diagnosis of these neoplasms. The cellular distribution of the B and M polypeptide subunits of creatine kinase in normal and neoplastic tissues were evaluated by an immunoperoxidase technic to determine whether the BB isoenzyme is present in neoplastic epithelial cells and whether immunoperoxidase stains for these polypeptides are useful in microscopic diagnosis. The results indicated that the B polypeptide is distributed very widely in epithelial cells and that normal and neoplastic ductal epithelia from many tissues contain the BB isoenzyme. Normal and neoplastic acinar epithelia contained varying amounts of the B polypeptide, but usually less than ductal epithelia of the same tissues. Large amounts of the B polypeptide were found in tissue sections from malignant fibrous histiocytomas, and of the M polypeptide in sections from an alveolar rhabdomyosarcoma.

Immunohistochemistry of prostatic acid phosphatase

The human prostatic acid phosphatase is a specific marker for the prostatic epithelial cells. By using an immunoperoxidase staining method for this enzyme, it is possible both to identify the prostatic epithelial cells and to recognize the prostatic origin of metastatic lesions of prostate cancer. Of the tissues containing prostatic epithelial cells from 120 patients, positive staining reaction was detected in 114 (95%), and negative in 6. In nonprostatic tissues from 242 patients, weak but positive staining reaction was detected in 8 (3.3%), including tissues from one renal cell carcinoma and 7 breast carcinomas. Of 27 patients in whom tumor tissues were tested at a time when tumor origin was unknown, the staining reaction was positive in 14 patients later found to have prostate cancer. It was negative in 6 patients with nonprostatic carcinoma and 7 patients with carcinoma of unknown primary. Although this immunohistochemical technique for prostatic acid phosphatase appears promising in diagnosing metastatic prostate cancer, its clinical significance and limitations remain unclear, and there are considerable technical problems yet to be solved. These problems are best approached by joint collaborative efforts of the various investigators interested in prostate cancer.

Immunohistochemical diagnosis of prostatic cancer with metastasis

An immunohistochemical method for detecting prostatic acid phosphatase is described for the diagnosis of metastatic prostatic carcinoma. The specific antiserum against prostatic acid phosphatase was prepared from rabbit by injection of acid phosphatase purified from seminal fluid. This method gives a selective staining of the cytoplasm of the glandular epithelial cells of prostatic tissue specimens on paraffin section. Most of the non-prostatic tissues were negative except for occasional weak staining in granulocytes, islet cells of pancreas, parietal cells of stomach, tubular epithelial cells of kidney, and liver cells. Also examined were 50 consecutive cases of metastatic tumor involving the bone marrow and 5 cases of metastatic prostatic carcinoma involving the lymph node or lung. All 20 cases with prostatic primary lesion showed positive staining. All other cases were negative, except 5 of the 14 cases of metastatic breast carcinoma in women showing weakly positive results. The method is fairly specific for identification of metastatic prostatic carcinoma. Occasional positive staining in breast tumor needs further study to establish whether the staining is due to the same isoenzyme or to certain cross immunoreactivity.

A streptomycete antagonist to Phellinus weirii, Fomes annosus, and Phytophthora cinnamomi

An actinomycete isolated from the rhizoplane of nitrogen-fixing nodules of Ceanothus velutinus was identified as a variety of Streptomyces griseoloalbus. Streptomyces griseoloalbus is a strong antagonist to three destructive root pathogens, Phellinus weirii, Fomes annosus, and Phytophthora cinnamomi, inhibiting all three on several culture media and preventing establishment of F. annosus on hemlock wood disks. The stability and longevity of the antimicrobial substance produced by it, its consistent effect on the pathogens on all substrates, its ability to colonize wood, and its ability to grow at 10 degrees C suggest biological control possibilities for this organism in the Pacific Northwest.

Carcinoid tumor of the thymus: a clinicopathologic report of seven cases with a review of the literature

Carcinoid tumor of the thymus is a rare neoplasm. Formerly confused with thymoma, a tumor of thymic epithelial cells, carcinoid tumor of the thymus has recently been shown to arise from cells of neuroendocrine origin that are normally present in the thymus. About half of the tumors are either functionally active (usually producing Cushing's syndrome) or are found in association with other endocrine tumors, as part of a multiple endocrine neoplasia syndrome. The remainder occur as symptomatic or asymptomatic anterior mediastinal masses, clinically indistinguishable from thymoma. At least 30% of thymic carcinoids are malignant on the basis of local invasion or metastasis or both. A protracted course, with late recurrence of tumor, is not uncommon. Aggressive surgical extirpation, followed by radiotherapy, offers the best hope for cure.

Immunological and biochemical evidence for identity of tartrate-resistant isoenzymes of acid phosphatases from human serum and tissues

We purified acid phosphatase isoenzyme 5b from a human spleen affected by leukemic reticuloendotheliosis and used it to produce a specific antiserum. The antiserum was used to show complete immunological identity among isoenzymes 5a and 5b in human serum, and 5b isolated from a giant-cell bone tumor and from the spleen of a case of Hodgkin's disease. Acid phosphatase 5b in a giant-cell bone tumor was isolated for biochemical characterization. Its pH optimum and substrate specificity were very similar to those of isoenzyme 5b from human spleen.

Immunological and biochemical evidence for identity of tartrate-resistant isoenzymes of acid phosphatases from human serum and tissues

We purified acid phosphatase isoenzyme 5b from a human spleen affected by leukemic reticuloendotheliosis and used it to produce a specific antiserum. The antiserum was used to show complete immunological identity among isoenzymes 5a and 5b in human serum, and 5b isolated from a giant-cell bone tumor and from the spleen of a case of Hodgkin's disease. Acid phosphatase 5b in a giant-cell bone tumor was isolated for biochemical characterization. Its pH optimum and substrate specificity were very similar to those of isoenzyme 5b from human spleen.

Malignant histiocytosis as a terminal condition in chronic lymphocytic leukemia

Chronic lymphocytic leukemia rarely develops an acute blastic phase as a terminal complication. When it does, the blastic phase is characterized by the appearance of large, immature cells with the same immunologic markers as the cells in the chronic phase of chronic lymphocytic leukemia; this coexistence of mature lymphocytes and blastic forms in chronic lymphocytic leukemia has been termed "Richter's syndrome." In a patient of ours with chronic lymphocytic leukemia, the development of a presumed large cell lymphoma was recognized on both bone marrow aspiration and biopsy examination, but later the condition was proved to be a true histiocytic neoplasm (malignant histiocytosis) by cytochemical and immunohistochemical techniques. We are unaware of another reported instance of malignant histiocytosis as a terminal complication of chronic lymphocytic leukemia and mimicking Richter's syndrome.

Eosinophilia in systemic mastocytosis

The diagnosis of systemic mastocytosis depends on the proper recognition of extensive mast cells infiltration in tissues. Accurate identification of the mast cells in tissues may be difficult when there is no clinical suspicion to initiate a special search for these cells. Four patients with atypical clinical features and eosinophilia in tissues and three with eosinophilia in blood had hematologic or histologic findings suggestive of myelofibrosis with myeloid metaplasia, and malignant lymphoma. It was the presence of blood and tissue eosinophilia in these patients that led to further investigation and recognition of the diagnosis of systemic mastocytosis. Methods for identification of the mast cells are examined. The combined use of Wright-Giemsa stain, toluidine blue, and aminocaproate esterase is preferred. The eosinophils are intimately related to the mast cells. In cases of eosinophilia of unknown etiology, systemic mastocytosis should be considered one of the possible etiologic factors.

Microproliferation of enterochromaffin cells and the origin of carcinoid tumors of the ileum: a light microscopic and immunocytochemical study

Using light microscopy, we studied the enterochromaffin (EC) cells in the intertumoral normal-appearing ileal mucosa in four cases of multiple ileal carcinoid tumors to investigate the mode of development of these tumors. There were 54 (39 mucosal, 15 submucosal) grossly invisible neoplastic microproliferations of cells with the attributes of EC cells, including immunocytochemical characteristics. No direct connection between these microproliferations and the intramucosal EC cells were demonstrated, nor was hyperplasia of EC cells found. Thus, we did not find a direct link between the intramucosal EC cells and carcinoid tumor.

Comparison of acid phosphatase isoenzymes of human seminal fluid, prostate, and leukocytes

We used ion-exchange column chromatography and electrophoresis on polyacrylamide gel to compare the acid phosphatase isoenzymes of prostate and leukocytes. The major isoenzyme of the prostate is band 2A; only a trace of band 2B was observed. However, the major isoenzymes of leukocytes are band 4 and band 2B, and only a small amount of band 2A was observed. The three isoenzymes isolated from leukocytes or prostate gland react to the antiserum prepared against the aicd phosphatase isoenzyme of seminal fluid. Acid phosphatases of leukocytes other than the three isoenzymes mentioned above did not interact with the antiserum.

Comparison of acid phosphatase isoenzymes of human seminal fluid, prostate, and leukocytes

We used ion-exchange column chromatography and electrophoresis on polyacrylamide gel to compare the acid phosphatase isoenzymes of prostate and leukocytes. The major isoenzyme of the prostate is band 2A; only a trace of band 2B was observed. However, the major isoenzymes of leukocytes are band 4 and band 2B, and only a small amount of band 2A was observed. The three isoenzymes isolated from leukocytes or prostate gland react to the antiserum prepared against the aicd phosphatase isoenzyme of seminal fluid. Acid phosphatases of leukocytes other than the three isoenzymes mentioned above did not interact with the antiserum.

Significance of "high" acid phosphatase activity in the serum of normal children

Serum acid phosphatase activity in normal children (newborn to 18 years) is several fold that in normal adults. Activity is age-related but not sex-related. The isoenzyme pattern in children is similar to that in adults and contains no prostatic fraction. Quantitatively, most of the enzyme activity in the serum of children is tartrate-resistant and correlates well with heat-labile fractions of alkaline phosphatase activity in serum, suggesting that the source of the higher acid phosphatase activity in children is bone. Significant tartrate-resistant acid phosphatase activity was demonstrated in the giant cells in three patients with giant-cell tumors, but not in the "osteoblasts" in six patients with osteogenic sarcomas and many other normal or abnormal tissues. This work suggests that the higher enzyme activity in the serum of children represents a normal physiological phenomenon resulting from their greater osteoclastic activity.

Significance of "high" acid phosphatase activity in the serum of normal children

Serum acid phosphatase activity in normal children (newborn to 18 years) is several fold that in normal adults. Activity is age-related but not sex-related. The isoenzyme pattern in children is similar to that in adults and contains no prostatic fraction. Quantitatively, most of the enzyme activity in the serum of children is tartrate-resistant and correlates well with heat-labile fractions of alkaline phosphatase activity in serum, suggesting that the source of the higher acid phosphatase activity in children is bone. Significant tartrate-resistant acid phosphatase activity was demonstrated in the giant cells in three patients with giant-cell tumors, but not in the "osteoblasts" in six patients with osteogenic sarcomas and many other normal or abnormal tissues. This work suggests that the higher enzyme activity in the serum of children represents a normal physiological phenomenon resulting from their greater osteoclastic activity.

Acute lymphoblastic leukemia in children: immunologic, cytochemical, morphologic, and cytogenetic studies in relation to pretreatment risk factors

Thirty children with previously untreated acute lymphoblastic leukemia were studied prior to therapy to determine whether sheep erythrocyte (E)-receptor status correlated with clinical factors, cytochemical staining characteristics, FAB morphologic classification, and karyotype. Five patients (17%) with more than 50% E+ blasts had intense focal acid phosphatase staining and distinct clinical characteristics, including high leukocyte counts, mediastinal masses, and involvement of the central nervous system at diagnosis. Focal acid phosphatase activity was present in blasts of patients with greater than 20% E+ blasts, but this group had fewer poor risk factors. Morphologic and karyotypic features were not related to erythrocyte-receptor status, but the L2 morphologic appearance occurred more frequently in older patients (P less than 0.05). Erythrocyte receptors have both qualitative and quantitative clinical correlations in childhood acute lymphoblastic leukemia; however, E+ and E- groups are heterogeneous and E+ groups must be analyzed for other risk factors and relapse rates determined before firm conclusions can be made about erythrocyte rosetting as an independent risk variable.

Systemic mastocytosis with review of gastrointestinal manifestations

A 63-year-old man presented with fever, splenomegaly, steatorrhea, diarrhea, and weight loss. A tissue diagnosis of systemic mastocytosis was made. This case is unusual in that diarrhea and steatorrhea were present in the absence of skin lesions and because fever was a prominent symptom. Thus, systemic mastocytosis should be included in the differential diagnosis of intestinal malabsorption even when the skin shows no abnormalities. The gastrointestinal manifestations of systemic mastocytosis are reviewed.

Histochemical and immunohistochemical study of diffuse large-cell lymphomas

Ninety diffuse large-cell lymphomas (diffuse histiocytic lymphoma) were subclassified into B-cell, T-cell, and histiocytic types according to their enzyme histochemical and immunohistochemical characteristics. The B-cell type was characterized by presence of intracellular monoclonal immunoglobulin; negative or weakly positive diffuse acid phosphatase activity; and an occasional focal nodular pattern or preceding nodular lymphoma. The T-cell type was characterized by moderate, focal acid phosphatase activity; convoluted nuclear structure; and frequent preceding cutaneous manifestations. The histiocytic type was characterized by strong nonspecific esterases and diffuse acid phosphatase activity and presence of lysozyme and phagocytic activity. Most of the lesions (74 cases) were of the B-cell type. This group was further subdivided into follicular center cell type and B-cell immunoblastic sarcoma, according to the stage of cellular transformation. Preliminary clinical correlation suggests that the histiocytic type is most resistant to treatment. B-cell immunoblastic sarcomas were much more aggressive than neoplasms of the follicular center cell type.

The cytochemistry of tartrate-resistant acid phosphatase. Technical considerations

Cytochemical demonstration of tartrate-resistant acid phosphatase activity is essential for the diagnosis of leukemic reticuloendotheliosis. In order to perform this test correctly and to interpret the results propertly, it is necessary to understand the technical details of the cytochemical methods thoroughly. The method using naphthol--ASBI phosphoric acid--fast garnet GBC is recommended for this purpose, and factors crucial to the cytochemical study, such as fixation, substrate, coupler, pH and temperature of incubation buffer, counterstains, and mounting media are examined and discussed. Conventional methods for acid phosphatase in the presence and absence of L(+) tartaric acid are also critically examined. The naphthol--ASBI phosphoric acid--fast garnet GBC method is sensitive, technically simple and easily reproducible. Its reaction product is highly chromogenic and is most suitable for cytochemical demonstration of acid phosphatase and tartrate-resistant acid phosphatase activity in cytologic preparations. The naphthol--ASBI phosphoric acid--pararosaniline method is highly specific and is best for histochemical demonstration of acid phosphatase and tartrate-resistant acid phosphatase in tissue sections.

Biochemical properties of tartrate-resistant acid phosphatase in serum of adults and children

Spectrophotometry of total acid phosphatase activity in children's sera showed an average value of 22.4 +/- 2.9 and 7.4 +/- 0.8 U/liter, for the hydrolysis of p-nitrophenyl phosphate and alpha-naphthyl phosphate, respectively. Analyses of "band 5b", after electrophoresis on acrylamide gel, gave even higher values. The values for children's sera were much higher than those for sera from adults. The multiplicity of acid phosphatases in sera of children and adults was studied by electrophoresis on acrylamide gel and by chromatography on CM-Sepharose. Both methods showed the major acid phosphatase in children's sera to be an acid pyrophosphatase, band 5b. Its catalytic properties are indistinguishable from the enzyme previously isolated from the spleen of leukemic reticuloendotheliosis.

Biochemical properties of tartrate-resistant acid phosphatase in serum of adults and children

Spectrophotometry of total acid phosphatase activity in children's sera showed an average value of 22.4 +/- 2.9 and 7.4 +/- 0.8 U/liter, for the hydrolysis of p-nitrophenyl phosphate and alpha-naphthyl phosphate, respectively. Analyses of "band 5b", after electrophoresis on acrylamide gel, gave even higher values. The values for children's sera were much higher than those for sera from adults. The multiplicity of acid phosphatases in sera of children and adults was studied by electrophoresis on acrylamide gel and by chromatography on CM-Sepharose. Both methods showed the major acid phosphatase in children's sera to be an acid pyrophosphatase, band 5b. Its catalytic properties are indistinguishable from the enzyme previously isolated from the spleen of leukemic reticuloendotheliosis.

Pulmonary processes of mature-appearing lymphocytes: pseudolymphoma, well-differentiated lymphocytic lymphoma, and lymphocytic interstitial pneumonitis

Patients with pseudolymphoma, well-differentiated lymphocytic lymphoma, and lymphocytic interstitial pneumonitis were studied. Diagnoses were confirmed by recently developed immunochemical staining techniques. Radiographic findings in pseudolymphoma were different from those in well-differentiated lymphocytic lymphoma, and clinical findings in lymphocytic interstitial pneumonitis were different from those in the other two types of lesions. The interstitial infiltrate of lymphocytic interstitial pneumonitis had two patterns: basilar with an alveolar component and diffuse with associated honeycombing. Pseudolymphoma and lymphocytic interstitial pneumonitis are being polyclonal inflammatory processes without malignant potential. Well-differentiated lymphocytic lymphoma, a monoclonal neoplasm, often has an indolent course.

Malignant lymphoma of plasmablastic identity. A neoplasm with both "immunoblastic" and plasma cellular features

A solitary extramedullary lymphoid neoplasm had characteristics of plasma cell precursors or plasmablasts. Conventional microscopic study classified this tumor as a diffuse large cell lymphoma of "immunoblastic sarcoma" type. Immunologic cell surface markers could not be detected, but cytoplasmic immunoglobulin G (IgG)-kappa was demonstrated by immunoperoxidase technic, and IgG was present in the supernatant of the tumor tissue culture. The distinction between lymphoid and plasma cellular neoplasms is made.

Histogenesis of splenic lesions in Hodgkin's disease

Histochemical markers were used to identify the various cellular and structural components of the human spleen, and to investigate the histogenesis of the splenic lesions of Hodgkin's disease. The early lesions appear in areas near the central artery (periarterial lymphatic sheath) in the white pulp. The white pulp becomes hypertrophic. The lesions enlarge, extend into the red pulp, and compress the sinuses and the cords of Billroth. The derivations of various "histiocytes" contained with the lesions are differentiated by using cytochemical stains for lysosomal enzymes and for granulocytes. The epithelioid cells in the granulomas are rich in those lysosomal enzymes typically seen in phagocytic histiocytes, suggesting that they are indeed true histiocytes. The malignant "histiocytes," including the mononuclear Hodgkin cells, the binucleated Sternberg-Reed cells, and the multinucleated giant cells, do not contain significant amounts of lysosomal enzymes and more closely resemble stimulated lymphocytes. The splenic lesions in Hodkin's disease may be the result of a lymphocytic and histiocytic cellular response to an unknown agent, which reaches the spleen through the central artery in the white pulp.

Blastic phase of agnogenic myeloid metaplasia simulating malignant lymphoma

A patient with angogenic myeloid metaplasia in blastic transformation with unusually prominent lymphadenopathy simulating lymphoma is described. Interestingly, the initial evidence of myeloblastic transformation was present in the lymph nodes but not in the marrow. Serial bone marrow biopsies showed fibrosis throughout the course of the disease, in spite of a gradual increase in the percentage of peripheral blood myeloblasts. Aneuploidy with a marker chromosome and a Philadelphia-like chromosome was present in the lymph node, bone marrow, and peripheral blood cells. The literature is reviewed regarding the incidence of prominent lymphadenopathy and chromosome abnormalities in agnogenic myeloid metaplasia and other myeloproliferative disorders.

Biochemical Properties of Human Prostatic Acid Phosphatase

The electrophoretic pattern (in polyacrylamide gel) for acid phosphatases in the prostate gland was compared with that for other tissues. Isoenzyme 2 predominates in the prostate. The isoenzyme was isolated from the prostate and its biochemical properties were compared with those of acid phosphatases isolated from spleen. Isoenzyme 2 has a molecular weight of about 100,000. Its optimum pH is between 5 and 7, unlike other lysosomal enzymes. Its substrate specificity is not very much different from those of the most active isoenzymes of acid phosphatase in other tissues. Our results contraindicate the use of a specific substrate in the analysis of prostatic acid phosphatases. Determination of the isoenzyme pattern is a new approach in the specific analysis of prostatic acid phosphatases.

Esterases in human leukocytes

The esterases of human leukocytes were studied both by cytochemical methods and by polyacrylamide gel electrophoresis. The aim of the study was to clarify the specificity of various cytochemical methods and to establish specific methods for demonstrating the various types of esterases in the blood cells. Nine bands of isoenzymes were separable by polyacrylamide gel electrophoresis at pH 4.0. Bands 1, 2, 7, 8 and 9 were best demonstrated by naphthol AS-D chloroacetate and represented the activity of chloroacetate esterase as demonstrated by cytochemical methods in the granulocytes. Bands 3, 4, 5 and 6 were best demonstrated by naphthyl esters and represented "nonspecific esterases" as demonstrated by cytochemical methods in the monocytes, platelets and plasma cells. "Aminocaproate esterase" or "trypsin-like enzyme" was demonstrated only in the human mast cells. Its exact location in the gel system is unknown since pure human mast cell preparation was not available for study. These three groups of esterases had a substantial but not absolute substrate specificity. They can be specifically demonstrated in the various types of human blood cells only under properly controlled staining conditions.

Histochemical characterization of cellular and structural elements of the human spleen

Several histochemical methods were applied to identify the various cellular and structural elements of the human spleen. These included naphthol AS acetate esterase and reticulin stain for the sinuses, fluoride-resistant esterase for macrophages, alkaline phosphatase for vascular structures, chloroacetate esterase for neutrophils, cyanide-resistant peroxidase and chlorazol fast pink for eosinophils, toluidine blue for basophils and pseudoperoxidase for erythrocytes and erythroblasts. The methods are simple, sensitive and readily reproducible and are best used in combination, so that several types of cells can be identified simultaneously. The location of these cells in the spleen and the interaction between these cells are readily appreciated. These methods can be used to study the morphologic changes of spleen in various hematologic disorders.

Ultrastructural cytochemical demonstration of tartrate-resistant acid phosphatase isoenzyme activity in "hairy cells" of leukemic reticuloendotheliosis

The pathognomonic "hairy cell" of leukemic reticuloendotheliosis was studied for ultrastructural localization of tartrate-resistant acid phosphatase activity. The enzyme activity could not be demonstrated by Gomori's method, but it was readily demonstrated in the cytoplasmic vesicles and Golgi saccules of the hairy cell by substitution of naphthol AS-BI phosphoric acid for Na-beta-glycerophosphate of Gomori's medium. This apparent substrate specificity may be used as a marker for electron microscopic identification of the hairy cell, and may facilitate the study of histogenesis of leukemic reticuloendotheliosis.

Ultrastructural characteristics of the "hairy cells" of leukemic reticuloendotheliosis

The pathognomonic neoplastic reticulum cells, or "hairy cells" of leukemic reticuloendotheliosis from 6 patients were studied with the electron microscope. These cells demonstrated characteristic ultrastructural features which were distinctly different from those of lymphocytes, monocytes, or histiocytes. In 3 patients a distinctive ribosome-lamella complex was found. The biologic significance of this unusual cytoplasmic inclusion is still unknown. Its frequent presence in leukemic reticuloendotheliosis and its rarity in other neoplastic diseases suggest a substantial yet unexplained relationship between this complex and leukemic reticuloendotheliosis.