Immune regulation of 5T2 mouse multiple myeloma. II. Immunological treatment of 5T2 MM residual disease.

The transplantable murine 5T2 multiple myeloma (MM) has been shown to be sensitive to idiotype-specific immunity, provided the recipient mice were immunized before transplantation. In the present study, anti-idiotype treatment was initiated after inoculation of the mice with 5T2 MM cells. Since in MM the serum idiotype concentration is far too high for anti-idiotype antibodies to reach the target cells, reduction of the MM to a minimal residual disease should be performed before. Intravenous (i.v.) or intraperitoneal (i.p.) administration of allogeneic (BALB/c) monoclonal anti-5T2 MM idiotype antibodies 3 days after i.v. infusion of the 5T2 MM cells into the mice, i.e. before 5T2 MM idiotype was serologically detectable, prevented the development of 5T2 MM in the majority of the animals. All mice that had not been treated with the anti-idiotype antibody became seropositive for 5T2 MM idiotype after 6 weeks. When mice with clearly developed 5T2 MM were treated with cyclophosphamide in order to obtain substantial tumor reduction, subsequent i.v. treatment with anti-5T2 MM idiotype antibodies resulted in prevention of myeloma growth in most animals. Injection of the antibody i.p. was, however, less effective. All mice that had been treated with cyclophosphamide only became seropositive for 5T2 MM and died. The results of these experiments demonstrated that passive anti-idiotype treatment of 5T2 MM is successful if the tumor mass is very small. The effector mechanisms of this treatment has to be investigated.

Human monoblastoid cell line U-937 cultured in protein-free medium: immunophenotype, cytochemical and biochemical markers.

Human monoblastoid cell line U-937 was adapted to grow in protein-free (protein-free hybridoma--PFH) medium and cloned by limiting dilution. Resulting cell subline (U-937/PF) cultured in protein-free medium was characterized by immunological, cytochemical and biochemical techniques. There were no major differences in immunophenotype (determined by FACS analysis with monoclonal antibodies directed to HLA and CD antigens) and cytochemical markers between the U-937/PF cells cultured in protein-free cell culture medium and parental U-937 cell cultured in serum-supplemented medium. Maximal cell density was slightly decreased in protein-free culture as compared to the parental cell line in FCS-supplemented medium. Cell viability and cell DNA histograms (determined by propidium iodide cytofluorimetry) showed no major differences between parental U-937 and U-937/PF cells. Phorbol ester (TPA)-induction of differentiation-associated cell markers resulted in a proliferation arrest and accumulation of G0/G1 cells in both sublines. All-trans retinoic acid and, to a lesser extent, TPA-stimulated NBT reduction was higher in parental U-937 cells cultured in serum-supplemented medium as compared to U-937/PF cells. Quantitative differences in the expression and inducibility of some cytochemical markers (beta-glucuronidase, chloroacetate esterase) were found between both examined sublines. Described U-937/PF subline cultured in a protein-free cell culture medium (PFH) appeared as a potential tool for studies of in vitro inducing agents and serum components with differentiation promoting (or inhibiting) activities.

Ultrastructure of erythroblast mitochondria in mice treated with mixtures of radioprotectors.

Unirradiated mice were given i.p. a mixture of mexamine (20 mg/kg body weight) and AET (150 mg/kg body weight) or mexamine (20 mg/kg body weight) and cystamine (150 mg/kg body weight). Acute effects of these mixtures of radioprotective agents on the ultrastructure of basophilic and polychromatic bone marrow erythroblast mitochondria were studied. One hour after injecting mice with above-mentioned mixtures, statistically significant differences in the size of mitochondria were found between control mice and mice given a mixture of mexamine and cystamine. The differences in the number of dilated cristae per micron 2 of the mitochondrion area between control mice and both experimental groups given mixtures of radioprotective agents were also statistically significant. Thus it was proved that also mixtures of radioprotectors induced acute ultrastructural changes of mitochondria which were so far described only after treating mice with only one radioprotective agent.

Radiobiological predictors of tumor and acute normal tissue response in radiotherapy for head and neck cancers.

Importance of two assay of the measurements of potential doubling time (Tpot.) and survival fraction at 2.0 Gy (SF2) and a method modifying acute radiation response of normal oral mucosa are discussed. Tumor clonogen repopulation accelerates around day 28 of treatment and the rate of repopulation is not constant but continuously increases from about 0.3 Gy/day to 1.0-1.3 Gy/day between day 28 and 65 of treatment. It may suggest that Tpot. values decrease respectively. The relevance of the Tpot. measurements prior to the treatment to clinical situations is discussed. The SF2 value reflects the intrinsic radiosensitivity of human tumors. The SF2 values are expected to be valuable as a predictors for tumor response to radiation. Variations in the SF2 values depending on tumor characteristics and assay methods are discussed in relation to the dose-response and tumor cure probability. The effect of modification of an accelerate repopulation in the oral mucosa by stimulation with 2% silver nitrate solution is presented. Although the presented prognosticators are different in their nature, they might provide a rational basis for selecting patients into optimal radiation treatment and might allow to modify radiation response of dose-limiting normal tissues.

Causes of breast cancer misdiagnosis at physical examination.

2740 consecutive breast cancers undergoing physical examination were reviewed. Ninety-two subclinical cancers detected at mammography were excluded from further evaluation and the study focused on palpable false benign cancers. The sensitivity of physical examination varied according to T category (TIS = 0.48, T1 = 0.70, T2 = 0.90, T3 = 0.89, T4 = 0.93), age (20-29 = 0.77, 30-39 = 0.58, 40-49 = 0.75, 50-59 = 0.84, 60-69 = 0.90, greater than 69 = 0.94) and operator (range 0.69-0.89), a significant difference being recorded in favor of more expert operators. Multivariate analysis (Cox) showed that T category, patient's age and operator experience are independent determinants of sensitivity. This study confirms that physical examination is not very sensitive, particularly for small tumors and in younger women and should always be performed by expert operators.

Recent trends in uterine cervix cancer in Slovakia, 1968-1987.

The temporal trends in the incidence and mortality of uterine cervix cancer in Slovakia were evaluated. Only highly reliable and complete data from 1968-1987 derived from the National Cancer Registry of Slovakia were used. Incidence rates have fallen in the first part of the period studied, but this trend has reversed and the incidence rates of this cancer site have risen since about 1976. The mortality rates showed continuous and unchanged increase over the whole mentioned period. The analysis of the age specific incidence rates indicated the responsibility of the youngest age groups of women for the overall recent increase of the uterine cervix cancer incidence in this country, while the age specific mortality rates increased in nearly all age groups. The relatively high incidence and mortality rates of uterine cervix cancer in Slovakia in comparison with the same rates in other countries as well as the recent increase of both indicators, together with low proportion of the in situ forms could be attributed mainly to the deficiencies in the organization and performance of the cervical screening.

Detection of single-strand breaks in DNA induced by mitoxantrone in experimental tumors after in vivo treatment.

The fluorometric assay of DNA alkaline unwinding [15] was applied to murine tumor DNA after in vivo treatment. Mitoxantrone (MX) whose cytostatic effect has been extensively investigated was tested as DNA damaging compound. The single-strand breaks of DNA (SSB) in ascitic tumors (EAT. P388) and in solid tumors (B16a, B16) were detected after intraperitoneal administrations of 1 and 10 mg/kg MX in the course of 1 to 96 hours. The maximal number of SSB was measured after 1 to 6 hours and DNA damage outlasted 24 to 96 hours in dependence on the dose of MX and on the type of tumor. A dependence of DNA damage induced by MX on the route of tumor implantation was found. Ascitic tumor P388 and EAT were more than 5 times more sensitive to the effects of MX than solid melanomas. The SSB correlated well with the intracellular concentration of MX in the EAT cells.

Characterization of a new monoclonal antibody (TR-19) against human transferrin receptor and its application in topographic study.

A new monoclonal antibody TR-19 (IgG2a) directed to the human transferrin receptor (CD71) was prepared after immunization of BALB/c mice with human non-T, non-B ALL cell line REH-6. This monoclonal antibody (mAb) reacted in immunofluorescence with all human cell lines tested. The reactivity with human peripheral blood leukocytes was observed only after stimulation with phytohemagglutinin (PHA). The protein precipitated by mAb TR-19 has an apparent molecular weight of 180 kDa under nonreducing and 90 kDa under reducing conditions. Sequential immunoprecipitation showed that mAb TR-19 recognizes the same antigen as the reference anti-transferrin receptor mAb OKT9. The mAb TR-19 coprecipitates the radioiodinated transferrin as a complex with its receptor. The mAb TR-19 with other three mAbs (OKT9, 5E9 and MEM-75) was used in the topographic study of the transferrin receptor. By competitive binding radioimmunoassay it was found that these mAbs recognize two distinct antigenic sites: One is specified by mAbs TR-19 and OKT9 and the second by mAbs 5E9 and MEM-75.

Flow cytometry analysis of ploidy and proliferation activity in classical and spermatocytic seminoma.

In a series of 49 cases of seminomas, namely 19 classical seminomas, 21 seminomas with syncytiotrophoblastic cells and 9 spermatocytic seminomas, DNA ploidy and S-phase cell fraction of the cell cycle were estimated in paraffin-embedded histopathological material. DNA aneuploidy was detected in 16/19 classical seminomas (84%), in all seminomas with syncytiotrophoblastic cells (100%) and in 6/9 spermatocytic seminomas (67%). In three cases two distinct aneuploid stemlines were detected, in four cases regional variations in ploidy level were observed, clearly proving cellular heterogeneity within the studied specimens. No significant differences in distribution of ploidy levels of aneuploid tumors were detected either between distinct groups of seminomas or in relation to the age of the patients. On the other hand, mean values of S-phase cell fractions in our material offer statistically highly significant differences between defined groups of tumors. Spermatocytic seminomas had the highest level of proliferation activity, which is in contrast with the clinicopathological observations (relatively slow growth, rare occurrence of metastases, local malignancy). The results of proliferation activity analysis and the relatively highest incidence of diploid tumors support the theory of different origin of spermatocytic seminomas in comparison with other germ cell tumors.

Induction of NK and LAK activities in human lymphocyte culture by a cytosol fraction from leukemic myeloblasts and by monoclonal antibody CD 3.

The stimulating effect of cytosol fraction (F3) isolated from human myeloblasts (m.w. ranging from 30 to 100 kDa) and monoclonal antibody CD 3 (MEM 57) was tested on NK and LAK cell activities in peripheral mononuclear cells (PMNC) of normal donors and leukemic patients. The F3 fraction added in 10% of the total volume of RPMI 1640 medium induced significantly increased lytic activity of normal lymphocytes or IL-2 activated lymphocytes against K 562 cells in 3-day culture. Similarly, the proliferation of both cell cultures was enhanced by F3. The effect of F3 on NK and LAK cell activities in culture of PMNC from leukemic patients was less pronounced and synergic action of F3 did not occur, whereas the proliferation of leukemic cells was significantly enhanced. MEM 57 increased the cytotoxicity and cell proliferation in 3-day culture of normal lymphocytes at concentrations ranging from 10 to 250 ng/ml. MEM 57 stimulated also NK cytotoxicity estimated in freshly isolated normal lymphocytes. The deficient NK cell activity observed in PMNC of leukemic patients was induced by MEM 57 or its combination with IL-2 in 3-day culture. These observations indicate that combination of more immunomodulating agents can lead to shortening of the incubation time necessary for correction of the NK cell defective activity in PMNC of leukemic patients.

Liver-metastatic human colon carcinoma in immunosuppressed mice.

An experimental liver metastasis model using the HT-29 human colon carcinoma cell line is described. The tumor xenograft in immunosuppressed mice preserved the histological type as well as the human and gastrointestinal markers (HLA-I, CEA). This model seems to be suitable for the development of new therapeutic protocols as well as for the study of metastasizing of a frequent human tumor type.

Distribution of carbohydrate structures in individual maturation stages of myeloid leukemic cells.

The distribution of peanut agglutinin (PNA) receptors, nonspecific cross-reacting antigen (NCA) molecule and 3-fucosyl-N-acetyllactosamine (FAL) in myeloid leukemic cells isolated by density gradient centrifugation was compared using immunofluorescence test (IF). Patients with acute myelocytic leukemias (AML) type M2 and M5 showed low percentage of NCA+ and PNA+ cells. In chronic and acute phase of chronic myelocytic leukemias (CML) the number of NCA containing cells increased and the amount of PNA-binding cells decreased as more mature granulocytic fractions were isolated on Ficoll--Uropoline density gradient. In patients with myeloblastic crisis of CML (CML-BC) the number of cells expressing FAL structure did not change in relation to maturation stage of myeloid cells. Our results revealed that the expression of various markers could change in a different way during the differentiation of cells from myeloblasts to mature granulocytes.

Humoral leukocyte adherence inhibition (H-LAI) follow-up trials on malignant process in mice.

Humoral antitumor response of Lewis lung tumor-bearing mice was measured by humoral leukocyte adherence inhibition (H-LAI) test. The reactivity of serum against tumor antigens prepared from primary tumor and lung metastases could be revealed at the first day after injection of tumor cells. On the other hand, the macroscopical appearance of the primary tumors and lung metastases was observed after 5 and 11 days, respectively. These findings suggest that the immune reaction of the host could be detected by H-LAI test earlier than the tumor can manifest itself. The antigens prepared from primary tumors and metastases seemed to be very similar, however, the metastasis antigen had additional determinants as detected by the H-LAI technique. Comparison of two tumor lines, the original Lewis lung tumor (LLT) and its variant with high metastatic capacity (LLT-HH), showed high similarity between their antigens as tested in H-LAI system by cross-reaction probes.

Stimulation of thrombopoiesis in mice bearing experimental tumors.

Significant increase (p less than 0.05) in circulating platelet counts was observed in a wide spectrum of experimental tumors in mice. The mechanism of this abnormality was investigated in strain A mice bearing a transplantable ascites tumor, Sarcoma 180 (S 180). Thrombocytosis observed in the tumor hosts was not due to prolonged platelet surviva], as 51Cr platelet half-life was normal. On the other hand, stimulation of thrombopoiesis, expressed in terms of platelet 75Selenomethionine (75SeM) incorporation, appeared to be the primary reason for elevated platelet counts in the tumor-bearers. Evaluation of thrombopoietic activity in the femoral marrow and spleen by measuring organ uptake of 75SeM and megakaryocyte counts indicated that tumor-induced stimulation in thrombopoiesis may be attributed to enhancement in splenic activity. Pretreatment of normal mice with tumor ascites or tumor cell-conditioned medium resulted in enhancement in thrombopoiesis. The findings suggest the production of some factor(s) by the tumor cells which probably mediate the stimulation of platelet production in tumor hosts.

Notes to application of the V79 metabolic cooperation assay for detection of potential tumor promoters.

Many chemicals which promote tumorigenesis in vivo have been observed to inhibit metabolic cooperation between 6-thioguanine-resistant (6TGr) and sensitive (6TGs) Chinese hamster lung V79 cells. The apparent correlation between inhibition of metabolic cooperation in V79 cells in vitro and promotion of oncogenesis in vivo has led to the suggested utilization of the assay as a screen for tumor promoters. Several parameters concerning the V79 metabolic cooperation assay were investigated for an improved understanding of the usefulness and limitations of the assay in our laboratory conditions. We have found that the recovery of 6TGr cells were dependent upon the number of 6TGs cells plated, upon the generation time, passage number, and upon the co-cultivation period until the addition of selective agent. The ability of this assay to detect tumor promoters has been determined by the known tumor promoter phorbol ester TPA.

Estradiol and progesterone receptors in human cutaneous melanoma.

The presence of estradiol and progesterone receptors (ER and PR, respectively) was assessed in 24 removed cutaneous melanomas, adapting the routine procedure used for the detection of the presence of these steroid hormone receptors in breast cancers. The study included only those cases which were not subjected to any anticancer therapy before surgery. The ER and PR values were comparable to those found in breast cancer and the tumors thus investigated could be classified in the same four distinct groups, namely ER+PR+, ER+PR-, ER-PR+, and ER-PR-. Each group is expected to exhibit a specific rate of response to endocrine therapy. No relation was found between the presence of steroid receptors and the type of tumor tissues (benign and primary tumors, recurrences or metastases), or the sex of the patients. Because of the small number of cases in each age group we could not correlate the levels of ER+ and PR+ with the age of the patients. Saturation analysis, competition studies and Scatchard analysis were performed in order to determine the characteristics of ER. Our data suggest that cutaneous melanoma cytosols contain a saturable, high affinity and low capacity, specific binding component for estradiol. Further investigations are required to show that estrogen responsive tissues are functional in either melanocytes or melanomas from any species.

Cytotoxic chemotherapy-induced second primary neoplasms: clinical aspects.

The incidence of second malignancies was assessed by retrospectively analyzing data from previous studies in well-defined and closely followed patient cohorts. After a median follow-up of more than 6 years following MOPP (mechlorethamine/vincristine/procarbazine/prednisone) chemotherapy with or without radiotherapy, 5% of patients with Hodgkin's disease developed second primaries, 60% of which were leukemias. Melphalan caused a 3% leukemia rate among 1129 patients with ovarian cancer who were followed for a median period of 4 years. No leukemia was observed among 1132 breast cancer patients treated with adjuvant CMF (cyclophosphamide/methotrexate/5-fluorouracil) after a median follow-up of 7.5 years. Long-term, comprehensive studies are needed to improve the current knowledge and the prognosis of patients with second primary neoplasms.

Etiological factors in invasive corpus uteri carcinoma.

The case-control method was applied in order to test how various types of diet as well as past diseases, tobacco smoking and occupational exposure may affect the risk of incidence of corpus uteri cancer in the population of natives and among immigrant women. The highest risk of incidence was noted in the group of natives persistently using a diet rich in meat, animal fat, amylum meals and sugar but lacking raw vegetables. Such a high risk was not observed in the group of immigrant women what might be caused by more frequent change of the type of diet. Some past diseases (arterial hypertension, diabetes, diseases of organs of reproduction and urinary system) do affect a relatively high risk of corpus uteri carcinoma in both populations. However, no noteworthy results have been obtained in the risk of corpus uteri carcinoma as far as tobacco smoking and occupational exposure are concerned.

HPLC determination of polyamines in urine.

Determination of polyamines (putrescine, spermidine and spermine) in urine samples of patients was worked out using high performance liquid chromatography (HPLC) and pre-column derivatization. For HPLC separation, a method of reversed-phase chromatography with gradient elution of water-organic mobile phases, UV and fluorescence detection were applied. Special care was devoted to the preseparation step, the hydrolysis, derivatization and selective extraction of clinical samples. The optimal HPLC conditions were recommended for simultaneous determination of putrescine, spermidine and spermine in a minimal analysis time (about 15 min) and suitable chromatographic resolution values (Rij greater than 1.5). Detection limits for all polyamines were evaluated (40 pmol for putrescine, 25 pmol for spermidine and 20 pmol for spermine) for the analysis of polyamines in the urine. The urine samples of healthy people and the cancer patients were compared and the procedure or the complete analysis has been described.

Synergistic action of human fetal liver cells and growth hormone on stimulation and inhibition of myelopoiesis.

Human fetal hepatocytes from midtrimester fetuses were studied in their ability to support pluripotent hemopoietic progenitor cells (GEMM-CFU) and myeloid progenitor cells (GM-CFU). We compared the activity of fetal liver stroma to stimulate hemopoiesis of mixed and myeloid lineages without hormonal additional and by influence of human pituitary growth hormone (hGH). Colony-forming assays in a double-layer semisolid agar system were used. This study shows that addition of hGH to the fetal liver stroma has enhancing activity upon formation of myeloid colonies. It seems that this activity is not mediated through liver macrophages but by releasing other hepatocyte-derived factors, perhaps by somatomedins. A model of such regulation is proposed. Further, there were observed small, lymphocyte-like cells close to the germinal center of colonies. They are supposed to be the first maturated cells in myeloid colony cell population and to exert inhibitory role on pluripotent stem cell (PSC) self-renewal by direct cell-to-cell contact.

Dipyrone enhances intracellular accumulation and cytotoxicity of adriamycin in human chronic myeloid leukemia cells.

The cytotoxicity induced by dipyrone alone, or in combination with adriamycin (ADR) was studied in human chronic myeloid leukemia (CML) cells. The inhibition of 3H-thymidine incorporation into DNA was taken as a measure of cytotoxicity. While dipyrone alone indicated marginal inhibition, its combination with ADR demonstrated a potentiating effect (p less than 0.001), which was found to be irreversible. The enhanced cytotoxicity of the combination was a result of an increased drug accumulation as studied by the uptake of 14C-adriamycin. Observations indicate that dipyrone can be used to enhance the cytotoxicity of ADR in human CML patients.

Circumvention of drug resistance of P388/R cells by the combination of adriamycin and mitoxantrone with hyperthermia (42 degrees C).

P388/R, the adriamycin (ADR) resistant subline of murine P388 lymphocytic leukemia was cross-resistant to the drug mitoxantrone (MTN). One hour hyperthermia at 42 degrees C (HT) was employed along with ADR (10 micrograms/ml) and MTN (10 micrograms/ml) for circumventing the drug resistance of P388/R cells in in vitro-in vivo bioassays. Inhibition in the incorporation of tritiated thymidine into cellular DNA was measured to check the in vitro cytotoxic effect. Hyperthermia, ADR and MTN alone could not bring about significant degree of inhibition of DNA biosynthesis whereas the combination of ADR and MTN along with HT resulted in a synergistic cytotoxic action (p less than 0.001 and 0.01, respectively). The cells were treated with the drugs in vitro and inoculated into BDF1 mice. It was observed that ADR, MTN or HT pretreatment of the cells resulted in an increase of the life-span of the mice by 4.0-25.0%, 10-20% and 44-50%, respectively, whereas the pretreatment of cells with the combination of ADR and MTN with HT resulted in an increase by 104-125% and 212-220% in life-span of the mice, respectively. Studies revealed that the combination ADR-HT and MTN-HT resulted in circumvention of resistance of P388/R cells to ADR and MTN.

Monitoring of effects of cis-diamminedichloroplatinum (II). Part V. Comparison of in vitro Pt-cytostatic effect on blastic transformation of human and murine cells.

The effect of oxoplatinum on blastic transformation of human peripheral blood mononuclear cells (PBMC) was monitored following phytohemagglutinin (PHA) stimulation. The results were compared with those published in part III of the present work as well as with the effect of cisplatinum and carboplatinum on the blastic transformation of human cells. In addition, the influence of three Pt-cytostatics on blastic transformation (BT) of PHA pretreated murine splenic cells was studied, and a comparison of sensitivity to cytostatics was made between the murine splenic and human peripheral cells. Cisplatinum demonstrated the highest toxicity, and carboplatinum showed minimum toxicity. The highest inhibitory effect was noted when cytostatics were applied either simultaneously with, or 48 h after PHA, i.e., at the stage of maximum proliferating activity. The murine spleen cells showed higher susceptibility to the effect of Pt-cytostatics in blastic transformation test than human peripheral cells. The murine spleen nuclear cells revealed deeper BT inhibition at the same concentration of substance than the human PBMC.

Some electrochemical characteristics of synthetic analogs of nucleic acid components. III. Derivatives of 5-fluorouridine. An attempt to find correlation between some of their characteristics.

The polarographic reduction and parameter tg alpha of a series of synthetic 5-fluorouracil derivatives (various 5'-modified nucleosides) were studied. The studied compounds were compared with analogous nucleosides of the uridine series. It was confirmed that the value of tg alpha which may suggest a potential carcinogenic activity of the compound studied, is dependent upon the reducibility of the compound and is associated with the cleavability of the nucleoside bond, i.e. with the ability to liberate fluorouracil. It was found that Ftorafur, an antitumor agent widely used in clinical practice, displayed a very high value of tg alpha. In the group of polyaromates such high tg alpha values had been found in compounds which are known to have carcinogenic activity.

Ascitic tumor cell cycle metabolism and energetics.

Data are presented on Ehrlich ascitic tumor cells energetic metabolism, activities of the glycolytic enzymes and the pentose phosphate pathway enzymes, contents and synthesis rates of the macromolecules at various cell cycle stages. An attempt was made to correct the direct measurement by taking into consideration a systematic error introduced in the experiment by incomplete cells synchronization. Cell metabolism activation sharply increased at two mitotic cycle stages. At the first stage (end of G1-period, beginning of S-period) the processes associated with the preparation to reduplication and DNA synthesis were activated. The second activation wave (end of S-period, G2-period) was connected with cell preparation of mitosis. The coordination of cell metabolism variations during the cell cycle is shown.

Monoclonal antibodies to two adhesive cell surface antigens (CD43 and CD59) with different distribution on hematopoietic and non-hematopoietic tumor cell lines.

Two new murine monoclonal antibodies were prepared by hybridoma technique after immunization with the immature pluripotent leukemia cell line K562. The monoclonal antibody Bra10G (IgG2b) reacted in a non-lineage pattern with all examined hematopoietic neoplastic cell lines and peripheral blood cells (granulocytes, lymphocytes, erythrocytes) of healthy donors, with the exception of monoblastoid cell line U-937 and B lymphoma cell line Daudi. This monoclonal antibody immunoprecipitated an 18-20 kDa cell surface protein expressed also on the cell surface of examined non-hematopoietic (malignant glioma, melanoma and breast carcinoma) cell lines. These properties and the efficient inhibition of Bra10G binding to the cell surface of K562 cells by the reference CD59 monoclonal antibody (MEM-43) indicated that Bra10G belongs to the CD59 cluster of monoclonal antibodies which identify the human protectin molecule. The monoclonal antibody Bra7G (IgM) reacted with a 95 kDa cell surface protein expressed on hematopoietic cells (with the exception of erythrocytes) and was absent on the examined non-hematopoietic neoplastic cell lines. These data together with a partial inhibition of Bra7G binding by the reference CD-43 monoclonal antibody suggested the CD43 (leukosialin, sialophorin) specificity of this monoclonal antibody.

Monitoring of patients with non-seminomatous germ cell tumors of the testis by determination of alpha-fetoprotein and beta-human chorionic gonadotropin levels and by computed tomography.

The results of a 7-year monitoring of 230 patients with non-seminomatous testicular tumors are reported with respect to the employment of radioimmunoanalysis of alpha-fetoprotein and beta-human chorionic gonadotropin levels and CT examinations of retroperitoneum and lungs. Prior to orchiectomy, elevated levels of at least one of these markers were found in 79% of patients. After orchiectomy, tumor marker levels were in 70.4% of patients in agreement with the results of CT examinations. After the completion of chemotherapy, in more than a half of patients normal tumor marker levels and positive CT findings were observed. These results were most often due to the presence of mature teratoma. In Stage I patients the advantages of tumor marker determinations and CT examinations in the early detection of tumor progression have fully been confirmed.

In vitro effect of indomethacin on mitogen-induced lymphoproliferative response in lung cancer patients.

There is some evidence that prostaglandin (PGE)-secreting cells may have a role in immunosuppression in cancer patients. In this work we investigated the effects of indomethacin--a PGE synthesis inhibitor, on PHA-induced lymphoproliferative response in vitro. Twenty patients with lung cancer before therapy were included in this study. When compared to controls, the patients had significant decrease of T cell number and proliferative response to PHA (p less than 0.001) and increased number of mononuclear phagocyting cells (p less than 0.001). The degree of depression of lymphocyte response did not correlate with the number of mononuclear phagocytes. The presence of indomethacin in the culture induced significant (p less than 0.01) improvement of the reactivity in high percentage (75%) of patients with diminished lymphoproliferative response to PHA. In the patients with normal lymphocyte response, indomethacin did not change reactivity to PHA. These results indicate that PGE-secreting cells may contribute to the immune depression in lung cancer patients, and that indomethacin may have therapeutical potential in some patients.

The protective activity of Thymex L against radiotherapeutically-induced cellular immunodepression in lung cancer patients.

In order to prevent the radiotherapeutically-induced aggravation of initial immunodeficiency, a thymic preparation (Thymex L) was given to lung cancer patients simultaneously with irradiation. The parameters of both cellular and humoral nonspecific immunity were evaluated in two groups of patients: one was treated with radiotherapy only (60 Gy in 30 fractions); the other one received Thymex L (100 mg 3 times a week, total dose 1800 mg, i.m.) simultaneously with radiotherapy. The significant decrease of B and T cell number, and decreased lymphoproliferative response to PHA were found in all patients before therapy; the number and phagocyting capacity of blood monocytes, as well as the concentrations of circulating IgG, IgA and immunocomplexes, were all significantly increased. Immediately after irradiation the patients had even lower number of T and B cells, diminished reactivity to PHA and higher number of mononuclear phagocytes when compared to the values before therapy. In patients treated with Thymex L, the number of B and T cells and PHA-induced proliferative response were significantly higher than in those treated with radiotherapy only. No effect of this therapy was seen on active T cells, on high number and function of mononuclear phagocytes and on elevated concentrations of serum immunoglobulins and immune complexes. Our results indicate that Thymex L can successfully prevent the harmful effect of radiation therapy on cellular immunity in a majority of lung cancer patients.

Evaluation of squamous cell carcinoma antigen (SCC-Ag) in the diagnosis and follow-up of patients with non-small cell lung carcinoma.

The usefulness of squamous cell carcinoma (SCC) antigen as a tumor marker was investigated in 72 patients with histologically verified non-small cell lung carcinoma (NSCLC). Increased level of SCC-Ag was observed in 41%, mostly in patients with squamous cell carcinoma (69%). Positive serum SCC-Ag was correlated with lymph node metastases and with the stage of disease. The positive rate of SCC-Ag observed in patients without and with nodal metastases was 52.9% and 84.2%, respectively. Positive SCC-Ag level was observed in 50% of Stage I, 71.4% of Stage II and 78.9% of Stage III patients with squamous cell carcinoma of the lung. The study proved that preoperative SCC-Ag determination in patients with squamous cell carcinoma of the lung and the course of levels of this marker during postoperative follow-up was of importance. A high preoperative and postoperative SCC-Ag value suggested a worse prognosis.