Frequency analysis of cytotoxic T lymphocyte precursors in search for donors in bone marrow transplantation.

The usefulness of cytotoxic T lymphocytes precursors (CTLp) frequency analysis in the search for donors in bone marrow transplantation was studied. The frequency of anti-recipient CTLp was approached by limiting dilution assay in HLA matched unrelated, HLA partially matched related and HLA genotypically identical donors. The majority of patients examined were affected with different hematological malignancies. Alloreactive CTLp recognizing non-HLA gene products were not detected in pretransplant examination of two pairs of HLA identical siblings. However, an increased incidence of allospecific CTLp was identified in HLA matched MLC negative unrelated pairs. Thus, CTLp assay allowed to uncover the residual Class I incompatibilities that remained hidden in standard serotyping. In two matched unrelated pairs with high pretransplant CTLp frequency the severe acute graft-versus-host disease (GVHD) developed after bone marrow transplantation. Examination of other relatives in patients lacking an HLA identical sibling showed the importance of Class I incompatibility for CTLp generation as well. The lack of correlation between CTLp frequency and HLA-D disparity could suggest that Class II antigens do not participate in CTLp induction. With one exception we had good correlation between MLC and DNA analysis of Class II antigens demonstrating that MLC gives interpretable results even in unrelated pairs. Our results demonstrate the significance of CTLp frequency assay in detection of residual Class I incompatibilities in matched unrelated pairs and in assessment of Class I compatibility in related pairs. For that it should be used in the final selection of BMT donors.

Analysis of monoclonal immunoglobulin light chains in urine using two-dimensional electrophoresis.

High-resolution two-dimensional electrophoresis was used to analyze kappa-type monoclonal immunoglobulin light chains in urine of two patients with multiple myeloma. The patients were treated, remission lasted about 2.5 years. In the period of relapse of the disease, acid isoforms of kappa chains, pI < 4,95, which had not been present in the urine of these patients before, were found in urine of both patients. Kappa-type Bence-Jones protein in urine of one patient showed unusual behavior: It failed to precipitate in the range of 40-60 degrees C or on boiling.

Bacteremia and fungemia in cancer patients with venous catheters.

In 116 cancer patients with bacteremia and fungemia and neutropenia (71%) analysis for the cause was made with regard to the presence of venous catheter, previous therapy or prophylaxis, underlying disease and immunosuppression and etiology. The incidence of bacteremia in patients with catheter was 12x higher (8.25% vs. 0.76%) in comparison to those without catheter and the mortality in respective groups was 26.3% and 15%. Among 206 isolates, 128 (63%) were grampositive aerobes, 58 (27.5%) gramnegative aerobes and 20 (9.5%) fungi. The mortality was the highest in patients with catheter and fungemia (66.6%) and relatively higher in patients with catheter and gramnegative bacteremia.

Salvage chemotherapy for recurrent Ewing's sarcomas.

Metastatic disease tends to recur after remission of Ewing's sarcoma. The effectiveness of ifosfamide in patients with recurrent Ewing's sarcoma was reported in recent years. We administered IFOS combined with etoposide, pirarubicin, and cyclophosphamide to 4 Ewing's sarcoma patients with metastatic disease, and succeeded in inducing second remissions in all cases.

Early diagnosis of medullary thyroid carcinoma in a 13 years old girl.

Early stage of medullary thyroid carcinoma was diagnosed in a 13 years old girl from the family with incidence of MEN IIa. High level of calcitonin after pentagastrin stimulation was crucial for the diagnosis. Pentagastrin test as a regular screening for medullary thyroid carcinoma for all children over 3 years of families with MEN IIa is recommended.

Chronic myeloid leukemia: correlation between purine metabolism enzyme activities and membrane immunophenotype.

Peripheral blood or bone marrow of 24 patients with chronic myeloid leukemia (CML) were characterized for their surface membrane marker profiles using flow cytometry and fluorescence microscopy. Purine metabolism enzyme activities were compared with membrane immunophenotype and cytochemical stains. CML subtypes were correlated with the expression of surface membrane antigens detected by the monoclonal antibodies. On the basis of immunophenotyping we found the following characteristic marker profiles: In stable phase of CML (CML-SP)-CD15, CD11b, CDw65, CD13, in accelerated phase of CML (CML-AP)-CD15, CDw65, CD11b, CD13 and CD33, in myeloid blastic phase of CML(CML-BP-M)-CD13, CD33, HLA-DR, CD11b, CD15, CDw65, in myeloid and lymphoid (mixed) blastic phase of CML (CML-BP-M+L)-CD13, CD33, CD34, HLA-DR, CD11b, CD10 and in chronic myelomonocytic leukemia (CMML)-CD14, CDw65, CD11b, CD33 and HLA-DR. Analysis of purine metabolism enzyme activities showed that there was a correlation between the values of adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) and various types of CML. ADA levels in CML-SP, CML-AP and CMML were comparable with those in normal cells. In CML-BP-M, which represents proliferation of less mature myeloid cells (similar to less mature AML subtypes), ADA activity increased and PNP activity decreased. ADA activity was significantly different between control group and CML-BP-M (p < 0.01), between CML-SP and CML-BP-M (p < 0.05). The values of PNP activity were the highest in stable phase of CML (125 pkat. 10(-6) cells) and the lowest (23 pkat.10(-6) cells) in CML-BP-M+L. PNP activity in the other groups corresponded to control values. High ADA/PNP ratio was found in CML-BP-M and CML-BP-M+L (0.7 and 2.0, respectively) in comparison to CML-SP (0.2). It follows from our results that ADA/PNP ratio enables to discriminate between stable and blast phases of CML (p < 0.01). The level of the cytochemical enzymes (CHAE, MPO, SBB, ANAE and 5' NT) varied and reflected the degree of cell differentiation and maturation. CHAE and MPO were characteristic enzymes for CML, ANBE for CMML and 5' NT for CML-BP-lymphoid.

Activities of enzyme transducing extracellular signals--gamma glutamyltransferase and enzymes metabolizing glutathione in acute lymphoblastic and myeloid human leukemias.

The ectoenzyme gamma glutamyltransferase (GGT) a second messenger generating enzyme activity on the cytoplasmic membrane was biochemically analyzed in leukemic cells from patients with acute lymphoblastic and myeloid leukemias. The lower mean activity--0.594 IU/mg protein was noticed in patients with acute lymphoblastic leukemias (ALL), while the higher--0.956 IU/mg protein was found in acute myeloid leukemia patients (AML) in serum and 0.151 IU/mg protein in polymorphonuclear cells. The levels of the activity of glutathione reductase (GR) were increased but the activities of glutathione peroxidase (GSH Px) were significantly decreased in serum of leukemia patients.

Hormonal regulation of adenylate cyclase activity in circulating lymphocytes and its interrelationship with hormone sensitivity of tumor tissue in colorectal cancer patients.

The purpose of this study was to investigate the peculiarities of hormonal regulation of adenylate cyclase (AC) of blood lymphocytes in colorectal cancer patients and to compare these peculiarities with hormone sensitivity of AC of colorectal tumors and normal colonic mucosa. Basal and stimulated lymphocyte AC activity was studied in 51 healthy persons and 52 cancer patients (14 with colon cancer, 21 with rectal cancer and 17 with stomach cancer) aged 20-75 years. In 31 of 35 patients with colorectal cancer the AC activity was studied simultaneously in lymphocytes, tumor tissue and normal colonic mucosa. To evaluate basal and stimulated AC activity the measurement of c-AMP (Amersham kits) formed in the presence of ATP regenerating system was used. Basal and by VIP, pentagastrin and sodium fluoride stimulated AC activity in lymphocytes of gastrointestinal cancer patients was lower than in lymphocytes of healthy subjects of similar age. Stage dependence of the parameters under study was not found. There was a tendency for higher basal and stimulated lymphocyte AC activity in colon cancer patients as compared to stomach and rectal cancer patients. In colorectal cancer patients the peculiarities of lymphocyte AC reactions to stimulation were closer to those in tumor tissue but not to those in normal colonic mucosa. The reaction of lymphocyte AC to VIP and glucagon coincided more frequently with tumor AC reactions to the same hormones in case of hormone nonsensitive tumors. Thus, basal and stimulated lymphocyte AC activity in colorectal cancer patients was modified to some degree by tumor factors. Lymphocyte AC reactions to VIP and glucagon may be considered as indirect markers of hormone sensitivity of colonic tumors. Moreover, the probability of discovery of hormone nonsensitive tumors by this way is more reliable than hormone sensitive ones.

Synergistic antitumor activity of tumor necrosis factor-alpha and lovastatin against MmB16 melanoma in mice.

Lovastatin, the drug introduced recently to treat hypercholesterolemia and displaying antiproliferative activity against tumor cells in vitro, was used for the local therapy of MmB16 melanoma in mice. Female B6D2F1 mice were injected with 1 x 10(6) of MmB16 melanoma cells into the right hind limb. On the 7th day after the injection of tumor cells mice were divided into four groups and were injected with: (a) saline solution (control group), (b) TNF-alpha alone, (c) lovastatin alone, and (d) a combination of TNF-alpha and lovastatin. Statistically significant inhibition of tumor growth was observed in mice treated with both TNF (5 micrograms/day) and lovastatin (200 micrograms/day). We also observed the prolongation of survival of tumor-bearing mice after combined therapy with both TNF-alpha (5 micrograms/day) and lovastatin (1 mg/day) in comparison to all other groups. Our data suggest that lovastatin may synergistically potentiate the antitumor activity of TNF-alpha.

The release of TNF-alpha (factor) by peritoneal macrophages of hamsters bearing transplantable melanomas.

The influence of two kinds of transplantable melanomas on the secretory function of peritoneal macrophages, and particularly the release of TNF-alpha has been studied. The results showed a statistically significant increase of protein content in the supernatants from 24 h cultured macrophages from melanoma-bearing hamsters in comparison with control macrophages. The release of TNF-alpha by control macrophages was higher than that by macrophages of hamsters with transplantable melanomas. The decrease in release of this factor was more prominent in case of macrophages from hamsters bearing amelanotic melanoma, it may suggest that biological features of melanomas can influence peritoneal macrophages to release the TNF-alpha at different level.

Brick mortar exposure and chronic lymphocytic leukemia.

A case-control study of 130 patients with chronic lymphocytic leukemia (CLL) and 130 controls matched with respect to sex, age (2 years), type of residence (urban-rural) and area of residence (according to the national per capita income) was carried out. Conditional logistic regression analysis showed that, apart of four risk factors already described in the literature (work in a hazardous industry, hair dye use, family history of leukemia and exposure to electromagnetic radiation), brick mortar exposure was also significantly related to CLL.

Evaluation of biometric parameters of Morris hepatoma after application of human recombinant tumor necrosis factor.

The effect of human recombinant tumor necrosis factor alpha (h rec TNF-alpha) on the growth of Morris hepatoma 5123 implanted in the skeletal muscles of the thigh of Buffalo rats was investigated. The cytokine was repeatedly given in an intratumor administration (i.t.) in dose of 1.5 x 10(4) U once a day in regimens of four or eight days. Comparative groups consisted of animals which were given saline i.t. Control groups included healthy rats subjected to local cytokine effect. The experiments revealed an inhibitory effects of the preparation on the growth of tumors. Biometric parameters of the tumors induced indicated that the inhibition of Morris hepatoma was most effective after the eighth dose of h rec TNF-alpha. The administration of fourfold dose resulted in an initial loss of body mass increase. However, when injected eight times, the factor produced a relative tolerance reflected in minor reduction of actual body mass. The estimation of survival time in rats injected i.t. with h rec TNF-alpha, compared to those given saline, revealed statistically significant differences at the eighth repeated dose.

Hepatic perfusion index in evaluating treatment effect of transcatheter hepatic artery embolization in patients with hepatocellular carcinoma.

We assumed the hepatic perfusion index (HPI) in patients with hepatocellular carcinoma (HCC) treated by transcatheter arterial embolization (TAE) and compared the results with the following CT findings. From September 1993 to February 1994, 15 patients with newly diagnosed HCC, proven by biopsy, were studied. Hepatic perfusion index (HPI) studies were performed before-TAE as well as on the 1st day and 7th day post-TAE, and CT scans were performed before and one month after the TAE. HPI at 1st-day post-TAE (HPI1) over HPI pre-TAE (HPIp) and HPI at 7th-day post-TAE (HPI7) over HPIp were calculated. The HPI7/HPIps were chosen to evaluate the efficacy of TAE because they had better correlation with the CT findings than HPI1/HPIps. CT scans performed one month after the TAE showed obvious reduction of tumor size in all 7 patients with a HPI7/HPI p < 0.85 but in only 2 of the 7 patients with a HPI7/HPI p > or = 0.85. The difference was significant, with a p-value of 0.01 by Fisher's exact test. We consider that the HPI with its characteristics of relative safety, convenience, low radiation exposure, and inexpense, may provide an useful modality for early prediction of the efficacy of hepatic artery embolization in the treatment of HCC.

Evaluation of a hospital based cytology screening programme for reduction in life time risk of cervical cancer.

Hospital based cytology screening is one of the suggested alternative strategies for the developing countries. The present communication attempts to estimate the reduction in lifetime risk of cervical cancer initiated through a hospital based single lifetime screening programme. The percent reduction in cumulative incidence of cervical cancer during lifetime in different age groups of women was calculated after estimating the number of incident cases in the absence as well as presence of screening. Our analysis revealed that by introducing the single life time cytology screening in the group of hospital attending population, an overall reduction in the cumulative incidence of cervical cancer during lifetime was found to be 10.2%. It was further estimated that the reduction was much less in the early age groups (2.4-10.2% in 20-34 years) as compared to later age groups (11.2-55.6% in 35+ years).

Electrophoretic analysis of microheterogeneity of paraproteins in a patient with IgD myeloma.

High-resolution two-dimensional polyacrylamide gel electrophoresis (2-DE) was used to analyze more precisely serum and urine specimens of a patient suffering from IgD myeloma associated with renal insufficiency. The application of 2-DE with immobilized pH gradient followed by immunoblotting revealed the presence of acidic monoclonal delta chains, hidden on 2-DE by albumin. This approach also enabled to detect two other forms of delta heavy chains expressing both reduced (45 kDa) and high (110 kDa) mol. weight. The analysis of urine specimen proved the presence of three acidic isoforms of monoclonal lambda light chains together with multiple monoclonal light chain fragments, which strongly suggests amyloidogenicity of these monoclonal light chains.

Sensitization and photodynamic therapy (PDT) of gastrointestinal tumors with 5-aminolaevulinic acid (ALA) induced protoporphyrin IX (PPIX). A pilot study.

5-Aminolaevulinic acid (ALA) is a promising agent for photodynamic therapy (PDT) sensitization as it can be given orally and only causes skin photosensitivity for 1-2 days. In fluorescence and photodynamic studies 26 patients with benign and malignant gastrointestinal tumors were given 30-60 mg ALA orally (single or divided doses) and biopsies were taken of tumor and normal tissue at 1-24 hours for fluorescence microscopy. With 30 mg/kg, highest protoporphyrin IX (PPIX) levels were seen in esophagus, duodenum and less in colon, but without tumor selectivity. Better tumor selectivity was seen in colon after 60 mg/kg (5:1). Six patients had transient rises in transaminases and five mild nausea. Sixteen patients were later treated (after further ALA) with red light (628 nm, bare or diffuser fibre, 50-100 J at 50 mW at each site). All but two showed subsequent necrosis, but only 0.5-1.5 mm of depth. PDT with ALA is simple, safe and promising for tumors in the gastrointestinal tract. Modification of treatment parameters may make it suitable for larger lesions.

Induction of single strand DNA breaks in workers professionally exposed to polycyclic aromatic hydrocarbons.

An epidemiological study was performed on 42 workers from coke works with the aim to evaluate the usefulness of monitoring single strand DNA breaks (SSBs) in human lymphocytes to assess exposure to polycyclic aromatic hydrocarbons (PAHs) as well as the usefulness of SSBs induction as an indicator of biological effects of PAHs. SSBs can be readily quantitated by a simple fluorometric assay of DNA unwinding. Compared with the control group, statistically significant increase in SSBs was observed in coke oven workers occupationally exposed to PAHs. These findings are in agreement with previous results obtained by a different method of measuring DNA damage in subjects exposed to high PAH levels. The findings confirmed that SSBs determination in human lymphocytes reflected the exposure to PAHs and the FADU method appears to be useful in the revelation of effects of occupational exposure to industrial air pollutants such as PAHs.

Radiosensitizer AK-2123 as modulating agent in the chemotherapy of experimental metastases.

Therapeutic effect of Cyclophosphamide (CPA) and radiosensitizer AK-2123 (AK) combination versus CPA alone in the same doses was investigated on transplanted LL carcinoma and B 16 melanoma. Antimetastatic efficacy of different doses of CPA and combined therapy was evaluated. Our data demonstrate that the effect of combined treatment by CPA at low uneffective doses (60 mg/kg, 40 mg/kg, 20 mg/kg at the 3rd and the 7th day after transplantation) and AK at low daily doses (1 mg/kg and 0.1 mg/kg for 3-9 days after transplantation) is equal or superior to the effect of CPA alone at the therapeutic dose (120 mg/kg).

Action of retinoic acid on human glioblastoma-astrocytoma--14 cells in culture.

Monolayer and agar culture techniques were used to examine the antiproliferative activities and morphological alterations of glioblastoma-astrocytoma (G1-As-14) cells induced by 20 mumol retinoic acid (RA). RA treated cells assumed flattened appearance and formed multilayers no longer. Most of the cells formed cross-bridges with one another. RA treatment caused time-dependent, dose-dependent and cell seeding-dependent reduction of growth in both monolayer and in agar cultures. RA-induced growth inhibition was also affected by concentration of fetal bovine serum in the culture medium. All these effects could be reversed within 48 h after withdrawal of RA from the growth medium. The results demonstrated that the respective cell line was sensitive to RA-induced growth inhibition and morphological alterations which were generally associated with reduced expression of malignant phenotype.

Evaluation of the anticancer property of a new alpha-methylene-gamma-lactone derivative of phthalimide.

The anticancer property of a new alpha-methylene-gamma-lactone derivative of phthalimide (2, NSC 640168) was evaluated in two murine ascitic tumors namely Ehrlich ascites carcinoma (EAC) and sarcoma-180 (S-180) by in vivo screenings and in a battery of human tumor cell lines by in vitro screening. It was found that the compound has exhibited marginal to moderate in vivo activity in EAC and S-180, respectively, and significant in vitro cytotoxicity in SF-268, a human CNS tumor cell line. The compound, however, has not reached the criteria of significant anti-HIV activity.

Lung toxicity of chemotherapeutic agents detected by TC-99m DTPA radioaerosol inhalation lung scintigraphy.

We investigated the lung toxicity of chemotherapeutic drugs in patients with breast cancer by means of Tc-99m DTPA aerosol scintigraphy. Thirty three patients who underwent surgical resection for breast cancer were divided into two groups, those who received a combination of adjuvant chemotherapy and those who did not. Group 1 consisted of 19 patients who received adjuvant chemotherapy and group 2 consisted of 14 patients who did not received adjuvant chemotherapy. Chemotherapeutic agents included 5-fluorouracil 1000 mg, endoxan 1000 mg and MTX 50 mg, all given intravenously. Aerosol lung scintigraphy was performed in all patients, in the supine position. The degree of lung damage was presented as the half clearance time (T 1/2) in minutes from the dynamic lung images. Only the right lung was used to analyze clearance, in order to avoid interference from stomach activity on the left side. The results show T 1/2 times of 68.18 +/- 20.04 min and 94.46 +/- 34.78 min, over the right lung, for groups 1 and 2, respectively. The difference is significant, with a p-value of 0.016, using the Mann-Whitney U test. We conclude that some chemotherapeutic drugs such as MTX, may result in pulmonary damage and that aerosol lung scintigraphy can provide an objective mean for early detection of pulmonary damage during cytotoxic chemotherapy.

Normobaric oxygen as a sensitizer in radiotherapy for advanced head and neck cancer.

The aim of this study was to evaluate radiosensitizing effect of normobaric oxygen breathing in radiotherapy for advanced head and neck cancers. Forty seven patients with advanced squamous cell carcinomas of the head and neck (7% in Stage III and 93% in Stage IV) were entered in the study. Breathing the pure, normobaric oxygen was given for 15-20 min in the treatment room. Irradiation started immediately after oxygen breathing. Conventional, megavoltage radiotherapy to the total doses in the range of 46-67.5 Gy was used. The control group was 46 patients with the same diagnosis and stage treated by radiotherapy alone. Locoregional tumor control was 36% in the study group compared to 15% in the control (p < 0.05). Mean survival time was 15.8 and 11.8 months, and 3-year survival was 19% and 2%, respectively (p < 0.05). Survival depended on total tumor dose and total nodal dose. No significant influence of the tumor location on local control and importance of the size of dose per fraction and overall treatment time were found. The most common failure in both groups was persistent tumor. Mean recurrence time was 5 months in the study group and 8 months in the control. Present results suggest that the use of normobaric oxygen breathing prior to irradiation could increase effectiveness of conventional radiotherapy for advanced squamous cell carcinomas of head and neck.

Treatment of advanced esophageal cancer by means of irradiation, cisplatinum and 5-fluorouracil.

In the years 1985-1990, 30 patients with locally advanced and/or disseminated cancer of the esophagus (Stages III and IV) were treated by radiotherapy (RT) and chemotherapy (ChT) containing cisplatinum and 5-fluorouracil (5-FU). The median survival of the patients was 8 months (range 2.5-39 months); 13 Stage III patients survived 3-36 months respectively (median 11 months), while 17 Stage IV patients survived 2.5-27 months, respectively (median 6.5 months). The survival depended statistically significantly (p < 0.05) only on the presence or absence of residual tumor after therapy and not on other parameters observed. Clinical response to treatment was evaluated in 16/30 patients as follows: CR was obtained in 4 patients, PR in two, and NR in 10 patients. Median survival of 4 patients with CR was 31 months; relatively high rate of CR (4/16) could be explained by the small number of patients. However, favorable survival results in individual patients may be expected even in larger series, though the rate responders may be somewhat lower than that obtained in our study.

Differences in cancer incidence between parts with different socio-economic structure within a Swedish big-city area.

Two subareas with different socio-economic structure in the same big-city area were compared with respect to cancer incidence. Pulmonary cancer was overrepresented in the low socio-economic area. Smoking was more common in the same area, which may be a main contributory factor for the increased incidence of pulmonary cancer in that area. The results indicate that useful information, to be used as a base for local preventive measures, can be obtained from cancer statistics on the community level.

Malignant tumors in family members of colorectal cancer patients.

A case-control study comprised 286 colorectal cancer (CRC) patients and the same number of hospital controls individually matched by age, sex and place of residence. Both CRC and other malignant tumors were more frequent among first and second degree relatives of cases as compared to controls. The odds ratio (and 95% confidence interval) for CRC was 6.67 (2.34-19.01) and for cancers of other sites 1.6 (0.97-2.62).

Differential effect of protein kinase inhibitors (staurosporine and CGP 41,251) on TPA-induced homotypic aggregation and cell surface adhesion antigen expression in human monoblastoid cell line U-937.

The phorbolester (TPA)-induced homotypic aggregation of human monoblastoid U-937 cells was completely abolished by staurosporine, but not by a new selective protein kinase C inhibitor, benzoylated staurosporine derivative CGP 41,251, a compound with known anti-tumor and drug resistance modulating activity. Staurosporine, a protein kinase inhibitor with broad profile of inhibitory activity on diverse protein kinases, but not CGP 41,251 substantially inhibited the TPA-induced up-regulation of intercellular adhesion molecule-1 (ICAM-1, CD54) and to a lesser extent also its ligand CD11a. These results suggest that protein kinase C-independent mechanisms, inhibited by staurosporine but not by the selective PKC inhibitor CGP 41,251 are involved in the TPA-induced homotypic adhesion and modulation of cell surface adhesion antigens in the human monoblastoid cell line U-937.

Glutathione S-transferase isoenzymes and glutathione in renal cell carcinoma and kidney tissue.

Many studies have established the role of the glutathione S-transferases (GSTs) and glutathione (GSH) in the neoplastic process and the drug resistance of tumor. Using isoelectric focusing we separated different forms of GSTs in 28 renal cell carcinomas (RCCs) and in morphologically unchanged adjacent kidney. In addition we determined in RCCs and adjacent kidney the level of GSH and the activities of enzymes participating in synthesis and uptake of this thiol compound. We found higher activity of acidic GSTs and higher level of GSH in RCCs versus kidney. Therefore we suggest that both parameters may play the significant role in the well known phenomenon of intrinsic cytostatic drug resistance of RCC. We also observed the elevation of GSH synthetase activity in tumor tissues in comparison to the kidneys. It may indicate that GSH synthetase, catalysing the final step in GSH synthesis, may participate in the elevation of GSH concentration in RCCs. In this work we also compared the tested parameters in RCCs in relation to the size and local extent of primary tumor (T). We found significantly lower activity of gamma-glutamyl transpeptidase (GGT) as well as GSH synthetase in the group of T3 and T4 tumors than in T2 tumors. However, no substantial differences in GSH concentrations were observed between these distinguished groups.

Effect of trypan blue on the activity of lysosomal enzymes, tumor growth and cell ultrastructure in B16 melanotic melanoma in mice.

Trypan blue is known to act as a lysosome membrane destabilizer. We investigated the effect of this dye on the activity of cathepsin D, acid phosphatase and arylsulfatase in tissue homogenates of B16 melanotic melanoma, transplanted subcutaneously in C57BL/6J black male mice. We also examined the tumor growth and the ultrastructure of its cells. The mice were given subcutaneous injections of the suspension of B16 cells (10(6)), and then received the trypan blue solution intraperitoneally in four divided doses, reaching the total does of 0.1 mg/g b.w. (group I) or 0.4 mg/g b.w. (group II). The dye was administered each other day after the tumor transplantation. The control mice were injected with melanoma cells only. The animals were killed 2 weeks after the beginning of the experiment. We found that the activity of lysosome hydrolases was increased by 30% to 50% in groups I and II, respectively, as compared to the control animals. The tumor growth in groups I and II was accelerated, and some ultrastructural changes in the melanoma cells were observed. These included irregular shape of the nucleus, uneven dispersion of the chromatin, increased number of premelanosomes and Golgi structures. The number of lysosomes, however, remained unaltered. We postulate that the trypan blue promotes tumor growth through the enhancement of the activity of lysosomal hydrolases; this may be due to the increased permeability of lysosome membranes caused by the trypan blue.

Iron-responsive element-binding protein mRNA levels during erythroid differentiation of murine erythroleukemia cells.

The levels of iron-responsive element-binding protein (IRE-BP I) mRNA throughout the course of erythroid differentiation were investigated in several lines of murine erythroleukemia (MEL) cells (Friend 745, 707 and Fw cells). Fw cells are not inducible for ferrochelatase activity and heme synthesis. Cytoplasmic ferrochelatase mRNA and transferrin receptor (TfR) mRNA levels are only insignificantly increased in Fw cells after induction. We have found increased levels of (IRE-BP 1) mRNA during erythroid differentiation of MEL cells of all lines investigated. Run-on transcription reactions using isolated nuclei from Friend 707 cells showed increased (IRE-BP 1) gene transcription following induction of erythroid differentiation with 5 mmol hexamethylenebisacetamide (HMBA). The increase in (IRE-BP 1) gene transcription is only about 2-fold in comparison with 8-fold increase in the level of (IRE-BP 1) mRNA during 96 hours of Friend 707 cells induction. These findings indicate that the stability of (IRE-BP 1) mRNA might also play a role in the increase of (IRE-BP 1) mRNA levels after Friend 707 cells induction. The possible role of increased (IRE-BP) mRNA levels in the elevation of TfR numbers during erythroid differentiation is discussed.

Organomercury (II) complexes with anti-carcinogenic agents. I. Synthesis and characterization.

A few organomercury (II) complexes involving anti-carcinogenic ligands have been synthesized. The compounds are of the type p-MeOC6H4HgL1 (I), p-NO2C6H4HgL2 (II), p-MeOC4H4HgL3 (III) and p-MeC6H4HgL4 (IV) (HL1-6-mercaptopurine, HL2-6-thioguanine, HL3-5-fluorouracil, L4-phenyldithiocarbazate). Their composition has been determined from elemental analysis. Thin layer chromatography (TLC) studies demonstrate that the compounds are pure. Conductance measurement reveal that these derivatives are non-electrolytes. From IR and UV spectral studies the bonding modes of the ligands to the mercury (II) ion have been elucidated. The stoichiometry of the compounds has been confirmed on the basis of 1H and 13C NMR spectra. Some preliminary results of anti-neoplastic activity are reported.