Demonstration of proteinase inhibitors cystatin A, B and C in breast cancer and in cell lines MCF-7 and ZR-75-1.

Polyclonal rabbit antibodies to endogenous natural inhibitors of cysteine proteinases (cystatins) were used for their immunohistochemical demonstration in samples of breast cancers and in two breast cancer derived cell lines (MCF-7 and ZR-75-1). The influence of estrogen stimulation on the expression of these inhibitors was also studied. The results showed that all cystatins tested can be found equally inside carcinomatous cells or in surrounding connective tissue, as well as in both cell lines examined. Further, the expression of inhibitors can be regulated by estrogen, and a certain role of cystatins in the regulation of the mitotic activity and differentiation of mammary cells can be supposed.

Radioimmunoscintigraphy of human malignant melanoma. I. Pharmacokinetics and localization of 125I-labeled monoclonal antibody RG-12 in thymectomized mice bearing renal melanoma xenotransplants.

The novel RG-12 monoclonal antibody (MoAb) recognizing a high-molecular-weight antigen of human melanoma cells was radioiodinated and its biodistribution and tumor imaging was determined in immunosuppressed mice bearing xenografted human malignant melanoma HMB-2. Control and tumor-bearing mice were injected with 6 micrograms of 125I-labeled RG-12 IgG (8.9 MBq 125I-IgG/animal). Clearance of the MoAb from plasma had a mean half life of 20.6 hours. At day 2 after injection, radiolabeled RG-12 IgG localized in the tumor was 1.43% of the injected dose bound per gram tissue (ID/g), whereas the localization in the healthy kidney was below 0.5%. Tumor to tissue ratio of MoAb accumulation was low for hepatic tissue (1.25) but high for spleen (3.30) and kidney (3.25), respectively. Scanning with a gamma camera localized tumor mass in the right kidney and implanted peritoneal metastases.

Ganglioside composition in experimental tumors with different growth properties.

The composition of gangliosides was studied in four fibrosarcomas (FL, FLA, FLB, FLC) induced in the Lewis rat by Ferridextran, and in two clones of a spontaneous Lewis rat mammary sarcoma (C-1-SAM LEW and C-2-SAM LEW) and two supertransformed clones (S-174 and S-271) derived from these clones, using the B77 virus. The malignancy of the Lewis tumors was tested in terms of their ability to outgrow the RT-5 barrier in LEW.1x rats and expressed as the loss-rate of LEW.1x rats. As for the Ferridextran-induced tumors, the FL was the only one to have been rejected in nearly 100% of the LEW.1x recipients. Following presensitization with FL the other tumors were also rejected, though not at a rate of 100%. The rat loss-rate was: FL--0%, FLC--23.5%, FLB--36.5%, and FLA--82.6%. As malignancy increased, the composition of gangliosides showed signs of progressive simplification indicating a step-by-step repression of ganglioside biosynthesis involving first the disialoganglioside and subsequently also the monosialoganglioside pathways. Some less distinct decrease (but significant at the 5% level of probability) of gangliosides of the disialoganglioside pathway and an increase of the simplest ganglioside (GM3) were observed between the C-1 clone of SAM LEW and its S-174 supertransformant. However, the changes, especially in the C-2 clone and its supertransformant, were not such as would suggest a marked defect in the biosynthesis of gangliosides.

Cathepsin B in cells of two rat sarcomas with different rates of spontaneous metastasis.

The cysteine proteinase cathepsin B (EC 3.4.22.1) is believed to take part in biochemical processes underlying tumor metastasis. In the present study, the cellular localization, intracellular levels and extracellular release of cathepsin B activity were examined in vitro in cells of two rat sarcoma variants, LW13K2 and RPS, differing in their capacity to metastasize spontaneously to the lung of syngeneic LEW/CUB rats. The LW13K2 sarcoma metastasizes rarely, whereas the LW13K2-derived RPS variant produces a metastasis incidence of above 50%. Using fluorescent cytochemical staining, microgranular reaction centers of cathepsin B were observed in the cell cytoplasm, in some cellular processes, with apical localization in some of them, as well as at the extreme cell periphery in cells of both sarcoma variants. The appearance of this distribution of cathepsin B activity was delayed in the RPS variant. Biochemically, the intracellular level of cathepsin B activity was significantly higher in homogenates of LW13K2 cells than RPS cells. In contrast to the intracellular enzyme activity, RPS cells cultured in serum-free medium at pH 6.5 released a substantially higher amount of cathepsin B activity than LW13K2 cells into the extracellular environment; at pH 7.4 the initially higher release of cathepsin B activity from RPS cells later equalized with that from LW13K2 cells. Taken together, the results indicate that changes of pericellular pH can modulate the extracellular release of cathepsin B in both sarcoma cell variants and suggest that the rate of cathepsin B release under conditions of mildly acid pericellular pH could be related to the incidence of metastases observed in these rat sarcoma variants. Total intracellular cathepsin B activity did not exhibit positive correlation with the metastatic potential of the studied rat sarcoma variants.

Effect of inhibition of DNA synthesis on recovery of X-irradiated L5178Y-S cells, II. 9-beta-D-arabinofuranosyladenine.

The effects of 9-beta-D-arabinofuranosyladenine (araA) on radiosensitivity, postirradiation changes in the cell cycle distribution and DNA synthesis in mouse L5178Y-S lymphoma cells are described. Increase in the araA concentration (from 25 to 200 mumol/l) was is correlated with reduction in clonogenic survival except in the low concentration range. where resistance was observed. AraA treatment (200 mumol/l for 2 h) temporarily inhibited progression through the G1/S boundary. AraA (200 mumol/l applied immediately after X-irradiation (1 Gy) for 2 h gave a radiosensitizing effect with only slight changes in postirradiation cell cycle distribution; at higher doses (4 and 6 Gy) the effect was less pronounced. AraA slowed down progression through the cell cycle after irradiation and enhances the lethal effect of radiation. The phenomenon was dependent on the time between irradiation and araA treatment. The differences in dose-related radiosensitization created araA + X-ray survival curves with extrapolation numbers lower than 1. This may reflect the existence of relatively radioresistant and radiosensitive subpopulations in the araA-treated population.

Positive effect of direct current on cytotoxicity of human lymphocytes.

Normal or leukemic human lymphocytes treated with direct current (DC) showed enhanced antileukemic cytotoxicity. The enhancing effect of DC-treated lymphocytes was dependent on current density and time exposure. A desirable effect was achieved with current densities ranging from 5 to 10 mA/cm2 at a short exposition time (5--10s). Enhanced lymphocyte cytotoxicity occurred after a 48 h cultivation at 37 degrees C in a humidified atmosphere containing 5% CO2 and was proved by the increased number of trypan blue stained target cells, tumor-binding cells, and lymphocytes with activated nucleoli. Lymphocyte cytotoxicity measured immediately after DC-treatment was not enhanced. Furthermore, the cytotoxic effect was potentiated using media conditioned with interleukin-2 (IL-2) or cytosol fraction (F3) isolated from human leukemic cells. Such in vitro stimulated cytotoxic cells displayed reactivity against K 562 cells as well as fresh leukemic cells of allogeneic origin. Of considerable clinical interest is the observation that lymphocytes treated with DC in IL-2 or F3 conditioned media may enhance antileukemic cytotoxicity in peripheral lymphocytes of patients with hematological malignancies.

Study of differentiation of fresh human leukemic cells by low dose cytosine arabinoside (LD Ara-C) and 12-O-tetradecanoylphorbol-13-acetate (TPA).

The effect of LD Ara-C (10(-8) mol/l) (Ara-C), TPA (1.6 x 10(-7) mol/l) and 13-cis-retinoic acid (RA) (10(-6) mol/l) on the differentiation in liquid culture of bone marrow cells from 5 patients with acute lymphoblastic, 17 patients with acute myelogenous leukemia, 1 patient in myeloid and 1 in lymphoid crisis of chronic granulocytic leukemia was studied. Ara-C induced morphological and cytochemical differentiation into monocytic cells in 2 cases (M1, M5 type). TPA induced convincing morphological and cytochemical features of maturation into monocytic cells in 4 cases (two M1, one M2, and one M5 type) and into differentiated myeloid cells in 2 cases (M1, M4 type). RA in one case (M2 type) out of three AML studied induced cytochemical and immunocytochemical features of maturation. The results of the study indicate that although TPA is a better inducer of blast cell differentiation than Ara-C, however, neither is a potent differentiation agent of leukemic blasts in liquid culture. The heterogeneity of leukemic blasts within the same type of leukemia was confirmed by their different response to differentiating agents.

HLA antigens and bronchogenic carcinoma.

Twenty-one HLA-A and B antigens were determined in a study of 162 patients with lung cancer. Differences between antigen frequencies in cancer and control populations were determined by chi 2 analysis with Yates correction or Fisher's exact test. Cancer patients had a decreased frequency of the antigen HLA-B40 (pc = 0.003; relative risk = 0.21). In patients with differentiated types of the carcinoma and relatively better prognosis, decreased frequency of the antigen HLA-B40 was found (pc = 0.05; relative risk = 0.27). Our investigation was based on a thorough study of literary data.

Bone marrow necrosis in malignant diseases. A report on seven intravitally recognized cases.

Bone marrow necrosis (BMN) is a necrosis of the hemopoietic tissue including the fibrovascular medullary stroma. Most frequently, it is caused by failure of bone marrow microcirculation. It is a complication in a wide spectrum of diseases, most frequently of malignancies, and is only rarely diagnosed ante mortem. In 6 of our 7 intravitally diagnosed cases, BMN was recognized already at the cytological examination of the bone marrow and was verified by the histological examination of the biopsy specimens as well as at necropsy. All our patients suffered from various malignant diseases. Three had generalized gastric carcinoma, the remaining hematological neoplasias: Acute lymphoblastic leukemia, acute monocytic leukemia, blastic transformation of chronic granulomegakaryocytic myelosis and primary medullary centrocytic lymphoma. The survival varied from 4 to 14 weeks after the BMN diagnosis. Clinical, hematological and autopsy findings as well as the etiopathogenetic views and prognostic implications of the diagnosis are discussed.

Estrogen receptor content in nuclear pellet from adenocarcinoma corporis uteri biopsies.

Ninety-one patients with Stage I and II endometrial carcinoma were investigated. Biopsy material obtained prior to primary treatment was analyzed for contents of estrogen (ER) and progesterone (PgR) receptors, and the values of these were related to the degree of malignancy. ER content in the nuclear pellet was decreased at increased tumor anaplasia.

A simulation approach for estimating the loss of womanyears due to cervical cancer and probability of developing cervical cancer.

Using a simulation approach, the number of womanyears that can be saved by preventing cancer of the uterine cervix was estimated. Probabilities of developing cervical cancer in the lifetime were also estimated. The number of years saved varied from 42 in the women aged between 20 and 24 years to 2 years in women aged 70 years and above. Probabilities of developing cervical cancer in the lifetime varied from 5.2% in women aged between 20 and 24 years to 0.6% in women aged 70 years and above. The results indicate that a noticeable incidence starts only after 35 years of age and about 90% of the total years can be saved by preventing the disease in women aged between 35 and 64 years.

Comparison of some biochemical parameters of arabinosylcytosine and cyclocytidine in L1210 murine leukemia cells.

The basic biochemical characteristics of cyclocytidine hydrochloride (cC.HCl) and arabinosylcytosine (araC) were compared. It was demonstrated that despite different lipophilicity and different pK (4.15 for araC and 6.60 for cC.HCl), the mechanism of inhibition of DNA synthesis by both compounds is the same (ID50 for araC was 0.048 mumol/l and for cC. HCl 0.23 mumol/l). The compounds had a different mechanism of inhibition of RNA synthesis (ID50 for araC was 2.69 mmol/l and for cC.HCl 1.08 mmol/l) and showed a marginal effect on protein synthesis. Hydrolysis of the 0(2),2'-anhydro bond in cC.HCl and formation of araC in vivo was characterized by a Km = 280 mumol/l using HPLC. Deamination of araC in vivo was studied in healthy mice (Km = 247 mumol/l), 8.6% of arabinosyluracil 15 minutes after araC administration) and in mice with sensitive and araC resistant leukemia L1210 (15.5% and 8.5% of arabinosyluracil 15 minutes after araC administration, respectively). On the basis of different physico-chemical properties of cC.HCl and different mechanisms of inhibition of RNA synthesis it can be assumed that cC.HCl, when therapeutically used, may have its own mechanism of biological effect(s) and that its application may be therapeutically advantageous in some aspects as compared to araC.

Studies on natural killer cells in chronic myeloid leukemia patients in remission.

In our earlier studies, the natural killer (NK) cell mediated cytotoxicity was found to be impaired in 55% of chronic myeloid leukemia (CML) patients in remission (low NK responders), while the rest exhibited normal range of cytotoxicity (normal NK responders). In the present investigations probable factors contributing to the impaired NK activity of low NK responder CML patients have been analyzed. Peripheral blood lymphocytes (PBL) from both low and normal NK responder CML patients possessed normal percentages of HNK-1+, CD3+ and CD8+ cells. The proportion of HNK-1+ cells and CD8+ cells in low density fractions (LDF) and high density fractions (HDF) respectively of Percoll separated PBL from low and normal NK responder CML patients and healthy donors was comparable. However, the NK activity of LDF cells of low NK responder CML patients was much lower. Also, HDF cells from low NK responder CML patients exhibited a regulatory effect on NK cytotoxicity of PBL from healthy donors. Therefore, it is likely that the presence of suppressor cells and perhaps an intrinsic inability of HNK-1+ cells may together contribute to the impaired NK cytotoxicity of low NK responder CML patients.

Alpha-2-macroglobulin is not synthesized by human urothelial cell lines in vitro.

We have analyzed 14 human urothelial cell lines in two different transformation grades for the production of a tumor-associated-alpha-2-macroglobulin. It has been shown in radioimmunoprecipitation and immunoblotting tests that human urothelial cells in vitro do not synthesize the wide-spectrum proteinase inhibitor alpha-2-macroglobulin. Four of the tested cell lines were additionally tested for the expression of specific mRNA which resulted in negative findings. The significance of the absence of alpha-2-macroglobulin in the human urothelial cells is discussed.

Hydroxyurea as a suppressor of the radioprotective effect of dextran sulfate on bone marrow hemopoietic stem cells in mice.

The changes in hemopoiesis of mice following intraperitoneal administration of dextran sulfate (DS) 24 h before irradiation, as well as the effect of injecting them with hydroxyurea (HU), were analyzed. DS increased the proliferation activity and number of hemopoietic stem cells (CFUs) in the bone marrow. The content of CFUs in the bone marrow and the number of endogenous spleen colonies (ESC) of hemopoietic tissue were higher after irradiation in mice treated with DS than in control groups. The survival rate following a lethal radiation dose was also higher. Injection with HU decreased the number of CFUs in animals injected with DS to the level of controls and suppressed its radioprotective effect.

Study of monomorphic determinants on DR molecules of HLA class II antigens.

The properties of monomorphic antigenic determinants on DR molecules of HLA class II antigens were analyzed with a panel of mouse monoclonal antibodies (mabs). Competition assays and immunoblottings showed that these mabs recognize three distinct antigenic sites. The cluster of antigenic determinants specified by mabs Bra30, Bra38, HL-39, MEM-12 and L243 belongs to the first antigenic site. The second antigenic site was demonstrated only with mab Bra20. The first two antigenic sites were detected only on DR molecules and they both depended on conformation and/or association of heavy and light chains of HLA class II molecules. Finally, the third cluster of antigenic determinants recognized by mabs Bra13, Bra22, Bra70, HL-38, and HL-40 is localized on light chains of both, DR and DP, molecules of HLA class II antigens. On the contrary to the mabs against the first two antigenic sites, reactivity of mabs with the third antigenic site was not affected by denaturation of HLA class II molecule.

A panel of monoclonal antibodies to keratin no. 7: characterization and value in tumor diagnosis.

Reactivity patterns of seven mouse monoclonal antibodies to human keratin 7 were compared using immunoblotting and immunohistochemistry on cultured cells and normal human and animal tissues. Differences in keratin specificities as determined by two-dimensional immunoblots and interspecies cross-reactivity data on 8 mammalian species suggest that at least six nonidentical epitopes of the keratin 7 molecule are recognized by this panel of reagents. Immunohistochemical examination of a panel of various human neoplasms with monoclonal antibodies monospecific for keratins 7, 18 and 19 revealed potential value of keratin subtyping in differential diagnosis of tumors in general and in subclassification of carcinomas in particular.

Vinblastine, cisplatin and bleomycin treatment of advanced nonseminomatous testicular tumors.

Between December 1979 and July 1986, 190 patients with nonseminomatous germ-cell testicular tumors were treated according to the modified Einhorn scheme. The response rate was 67.89%. The most favorable results were found in the embryonal histologic type (RR = 76.9%), in the biological marker (AFP, HCG) negative (RR = 97.43%) and in the minimal pulmonary extent group (RR = 94.12%).

Cytogenetic study of blood in women who had used oral contraceptives.

Changes in the number and structure of chromosomes in peripheral lymphocytes of 31 healthy women using oral contraceptives (OC) were studied. Blood samples were taken prior to and after one, two and three months of using oral contraceptives. No significant differences were found in evaluating numerical anomalies but highly significant differences were detected in structural aberrations and in structural aberrations without gaps.

Differentiation of human myeloid leukemia cell line ML-1 induced by retinoic acid and 1,25-dihydroxyvitamin D3.

Human myeloblastic leukemia cell line ML-1 was induced to differentiate by 1 mumol/l all-trans-retinoic acid (RA) or by 1,25-dihydroxyvitamin D3 (1,25(OH)2D3). After 4-6 days of the induction several differentiation-associated characteristics were observed: (1) Ability to stimulate respiration burst in the ML-1 induced cells as detected by nitroblue tetrazolium (NBT) test or by chemiluminescence (CL). (The percentage of the NBT-positive cells was up to 99% in the RA-induced cells and up to 85% in the 1,25(OH)2D3-induced cells.) (2) Substantially higher phagocytosis of colloid iron, latex or Staphylococcus particles was found in the induced cells. (3) The 1,25(OH)2D3-induced ML-1 cells expressed the monocytic enzyme NaF-inhibitable alpha-naphthyl butyrate esterase and the surface monocytic antigen CD-14. (4) A majority of the induced cells lost the morphological features of blast cells; while the 1,25(OH)2D3-treated cells acquired certain features of monocyte-macrophage differentiation, the RA-treated cells displayed several granulocytic characteristics. (5) Cytofluorometric DNA assay after treatment of the cells with colcemid showed that the decline observed in the growth rate of the induced cells was connected with their arrest in G1/G0 phase of the cell cycle. The obtained results indicate granulocytic differentiation of the RA-induced ML-1 cells and monocyto/macrophage differentiation of the 1,25-(OH)2-D3 induced cells.

Neuroendocrine features of adrenal pheochromocytomas: histological and immunocytochemical evaluation.

Neuroendocrine features of 30 surgically removed adrenal pheochromocytomas were evaluated combining conventional histochemistry and immunocytology. The reactivity for neuron-specific enolase (NSE), S-100 protein, vasoactive intestinal peptide (VIP), calcitonin and ACTH was tested according to the peroxidase anti-peroxidase (PAP) method using polyclonal antibodies. The neuroendocrine marker NSE was found in all cases. S-100 protein was present in satellite cells in 11 (36.6%) tumors. Rare immunoreactive cells for somatostatin were found in 16 (53.3%), for VIP in 8 (26.6%), for calcitonin in 7 (23%), and for ACTH in 3 (10%) cases. Our results proved the histological and functional heterogeneity of pheochromocytomas. The multiple synthetic activity is their inherent feature as in other neuroendocrine tumors.

A chloride activated alanine aminopeptidase from a melanoma cell line.

Alanine aminopeptidase was partially purified from cultured human melanoma cells (Bowes) by gel filtration on Sephadex G-200 and DEAE Sepharose column chromatography. The molecular weight of the enzyme was about 52,000 as determined by gel filtration on Sephadex G-100. The enzyme hydrolyzed L-alanine beta-naphthylamide (NA), but not or slightly L-methionine-NA, L-leucine-NA, and L-arginine-NA. The Km value for L-alanine-NA was 0.17 mmol/l, pH optimum was 7.4. The enzyme was stable at 50 degrees C for 20 min, but lost about 50% of its activity at 60 degrees C within 20 min. It was markedly stimulated by chloride ions, and was inhibited by sulfhydryl blocking agents and EDTA. The activity was restored by the addition of Co2+ or Zn2+ after EDTA treatment. The enzyme is a metallo- and thiol-dependent and chloride-activated, low-molecular weight aminopeptidase.

Distribution and rearrangements of alleles of c-Ha-ras-1 protooncogene and their correlation with the development of lung, ovarian and thyroid cancers.

The protooncogene c-Ha-ras-1 locus in 84 cancer patients was examined for allelic restriction fragment length polymorphism. The distribution of four common c-Ha-ras-1 alleles (a1, a2, a3 and a4) in lung, ovarian and thyroid cancer patients was analyzed. In approximately half (8 out of 15) of lung and ovarian carcinomas possessing the a4 allele, alterations of the c-Ha-ras-1 locus (deletion of allele with the shorter fragment length, amplification of a4 allele, change of allele fragment length) were detected as compared to 2 cases of rearrangement out of 40 tumors lacking the a4 allele. An increased a4 allele frequency was found in individuals with lung and ovarian tumors as compared to controls presented in literary data and thyroid cancer patients. On the other hand, homozygosity for the a2 locus resulting from the deletion of another allele, and increased a2 allele frequency in thyroid cancer patients were observed. Thus the a4 and a2 alleles of c-Ha-ras-1 may perhaps be viewed as genetic markers of predisposition to lung, ovarian and thyroid cancer, respectively, in combination with other clinical parameters.

Index of light kappa/lambda and lambda/kappa chains in monoclonal gammopathies.

Concentrations of the light chains kappa and lambda were determined by simple radial immunodiffusion in the blood sera of 437 patients with monoclonal gammopathies. The kappa/lambda index was calculated in monoclonal gammopathies with the antigenic type of kappa light chains, while in monoclonal gammopathies with the antigenic type of lambda light chains the lambda/kappa index was calculated. The results obtained in malignant monoclonal gammopathies were compared with the results obtained in monoclonal gammopathies of undetermined significance for IgG and IgM paraproteinemias. Differences of high statistical significance were established (for IgG and IgA p less than 0.001, for IgM p less than 0.005) and thus the light-chain index can be used as another marker in differential diagnosis of monoclonal gammopathies.

Investigation of anti-D antibody dependent cell mediated cytotoxicity in patients with thyroid cancer.

Anti-D dependent cellular cytotoxicity (ADCC) of peripheral mononuclear blood cells was measured in 69 thyroid cancer patients belonging to one of the main subtypes, and in 11 age-matched controls with benign thyroid disease. Independently of cancer subtype, tumor status, previous operation, age and sex, no differences in ADCC were observed. Further studies are warranted to clarify the cause of the constant ADCC levels.

The SOS chromotest study on cisplatin: the genotoxicity evaluation and analytical determination in human urine.

Mechanism of action of cis-diamminedichloroplatinum (II) (cis-DDP) was studied using genetically manipulated bacteria Escherichia coli K-12, recombinant PQ 37 (so-called SOS chromotest). Basic characteristics, namely strength of cis-DDP genotoxicity, influence of chloride ions on genotoxicity and dependence of genotoxicity versus time of cis-DDP aquation reaction were tested. The rate constant has been found to be 0.91 +/- 0.03 x 10(-4)s-1. Possibilities of the use of SOS chromotest in the determination of cis-DDP were found. The detection limit has been 0.09 mg/l in water as well as in urine. The amount of cis-DDP was determined in urine of patients after drug treatment. Analysis of clinical samples have been completed without any preseparation.

Purine metabolism enzymes and immunological phenotype in chronic B-cell malignancies: chronic lymphocytic leukemia, prolymphocytic leukemia and hairy cell leukemia.

The chronic lymphocytic leukemia, the prolymphocytic leukemia and the hairy cell leukemia of B-cell immunophenotype are closely related disorders, but differ in their cytomorphological and clinical features. In an attempt to differentiate further among these forms of leukemia some immunological and cytochemical markers were studied. Simultaneously we measured adenosine deaminase and purine nucleosidephosphorylase activities by a method of paper radiochromatography in peripheral blood/bone marrow leukemic cells from 23 patients with chronic lymphocytic leukemia, 5 patients with prolymphocytic leukemia, one with prolymphocytoid transformation of chronic lymphocytic leukemia and 15 patients with hairy cell leukemia. The mosaic of immunological and cytochemical markers based on the sum of positive and negative features allowed for the correct diagnosis in a majority of cases. From the number of 43 investigated cases we found the typical enzyme patterns in 39 of them. On the basis of purine enzyme activity we were able to differentiate between chronic lymphocytic leukemia versus prolymphocytic and hairy cell leukemia. In one patient with chronic lymphocytic leukemia we could detect very early stage of prolymphocytoid transformation by increased activity of purine nucleosidephosphorylase activity. There were only two patients with chronic lymphocytic leukemia who were assigned to the prolymphocytic leukemia on the basis of purine nucleosidephosphorylase activity and two patients with hairy cell leukemia with atypical enzyme pattern attributable to the nonrepresentative number of pathological cells in the peripheral blood. Our study showed that purine nucleosidephosphorylase activity in leukemia cells may be useful as an additional parameter in the distinction of prolymphocytic from lymphocytic leukemia and that it may represent an enzymatic marker for early detection of prolymphocytoid transformation of chronic lymphocytic leukemia. Characteristic purine enzyme pattern was found also for diagnostic confirmation of hairy cell leukemia.

Clinical significance of standard CD assessment in acute leukemia.

The data of detailed studies of immunophenotype of blast cells in 426 patients with acute leukemias are presented. Diagnostic and prognostic significance of different marker expression has been evaluated in groups of patients with ALL and AML. Frequency distribution of T1, T2, T3, pre-B, B, common, Ia and null subvariants identified according to immunoclassification of Baryshinkov et al. was studied in 250 children with ALL. These subvariants differed both in duration of disease (p = 0.0015) and in duration of first complete remission (p = 0.0031). The use of monoclonal antibodies of VI-series in 90 patients with ALL allowed to describe an immunophenotype of the subvariants in detail. The mosaic expression of myeloid antigens CD11, CD14, CD15, CDw65 identified by MoAbs VIM-12, VIM-13, VIM-D5 and VIM-2, respectively, on blast cells of patients with AML was shown. The expression of CD11 (ICO-GM1) or CD15 (ICO-G2) was prognostically unfavorable in children with AML (p = 0.0028). The expression of T-cell markers (E-receptor, CD7, reactivity with anti-T-cell serum) on blasts was prognostically favorable in children with AML (p = 0.003). So the data of immunophenotyping are of great value for accurate diagnosis and prognosis of acute leukemias.

Plasminogen activator (PA) in Guerin epithelioma. Additional PA inhibitor in plasma of rats bearing the epithelioma.

The presence of plasminogen activator (PA) with a Mr of about 35,000 was detected by SDS-PAGE in extract from Guerin epithelioma. The activator, which is a serine proteinase, was partially purified on Sephadex G-50 followed by Lys-Sepharose. Rat plasma, both of healthy and epithelioma-bearing animals, inhibited the activity of such isolated PA. However, the difference between these plasmas in their antiactivator action was observed after inactivation of plasma proteinase inhibitors. In such conditions, the control plasma lost the ability to inhibit the examined PA, whereas the plasma of epithelioma bearing rats retained this ability.

Occurrence rate of the HLA-identical pair donor-recipient for bone marrow transplantation.

HLA antigens and MLC reactivity were ascertained in 69 families, having altogether 198 children, with the aim to find genotypically identical donors for patients suffering from some type of leukemia or aplastic anemia. HLA identical, MLC negative sibling donors were found for 29 patients, i.e. 42.03%. In 55 leukemic patients the frequency of HLA antigens and haplotypes was calculated. No significant differences were found as compared to the healthy population. One recombination between HLA-A and HLA-B and one between HLA-B and HLA-D/DR loci were observed.