T. Lialiaris

Cytogenetic study in cultured human lymphocytes treated with three commonly used preservatives.

Potassium sorbate, sodium benzoate and potassium nitrate have been tested for their genotoxic, cytostatic and cytotoxic potential in human peripheral blood cells in vitro. Potassium nitrate has shown no activity in the test system. When potassium sorbate and sodium benzoate were used at concentrations of 2.0, 0.2 and 0.02 mM no cytostatic activity was detected. However, concentrations of 4 and 8 mM have shown a weak cytostaticity. Additionally, a genotoxic activity using the SCE methodology has been observed at 8 mM of sodium benzoate and at 4 and 8 mM of potassium sorbate. No cytotoxic activity has been induced by the three preservatives. Data demonstrate that the preservatives at low concentrations can be considered as non genotoxic under conditions tested.

Cytogenetic study for possible mutagenic activity induced by ice-nucleation bacteria or their metabolic products in human lymphocytes in vitro

A means for eliminating ice-nucleation-active (INA) bacteria, the microorganisms responsible for frost damage to plants at mild freezing temperatures, is the use as competitors of other naturally occurring, non-nucleating strains. Inactive mutants (INA-) of INA bacteria have been produced by genetic or chemical methods and proposed for biological control of INA populations. Since, however, the application of these INA- mutants in the field may create health hazards to animals, we have studied the possible mutagenic activity of the INA- mutants by examining chromosome aberrations, sister-chromatid exchange (SCE) frequencies, and proliferation kinetics of human lymphocyte cultures. These cultures were treated with: (a) a naturally occurring INA- bacterium (p 767), (b) 2 parental strains (cit 7 and cit 13) of INA bacteria isolated from Citrus orchards, and (c) 2 INA- mutant strains (cit 7 del 1b and cit 13-12), produced, respectively, by chemical modification and by deletion of the corresponding parental strains. Neither whole bacteria nor infiltrates of bacterial growth media, in which toxic metabolic bacterial products might have been released, induced elevation of either chromosome aberrations and SCEs or a cell-division delay. Negative results were also obtained when sonicated bacteria were tested for possible intracellular mutagenic components.

Enhancement of cytogenetic damage by chloropromazine in human lymphocytes treated with alkylating antineoplastics and caffeine

In cultured human lymphocytes chlorpromazine (CPZ) was found to induce cell division delays and to have no effect on sister-chromatid exchanges (SCEs) or on mitotic indices (MIs). CPZ induces cytotoxic effects in combination with caffeine (CAF) and alkylating agents. In combination with CAF it induced cell division delays and suppression of MIs. In combination with melphalan (MEL) and CAF, CPZ synergistically induced SCEs, caused cell division delay and suppressed MIs. In combination with chlorambucil (CBC) and CAF, CPZ produced synergism on induction of SCEs, enhanced cell division delays and reduced MIs.

Enhancement and attenuation of cytogenetic damage by vitamin C in cultured human lymphocytes exposed to Thiotepa or L-ethionine

Vitamin C (vit C) at 2 mM enhanced sister chromatid exchange (SCE) frequencies induced by Thiotepa (THIO) or L-ethionine (L-ETH) in cultured human lymphocytes. However, when vit C was tested at 0.02 mM and 0.2 mM a rather protective effect on SCE rates induced by THIO or L-ETH was identified. Vit C (2 mM) caused a cell division delay in cultures treated with THIO or L-ETH. Division delays caused by THIO or L-ETH were reversed in the presence of 0.02 mM or 0.2 mM vit C. Mitotic indices (MIs) in cultures treated with THIO or L-ETH continued to be suppressed in the presence of 2 mM vit C. However, vit C at 0.02 mM reversed suppression of MIs caused by L-ETH or THIO. These findings illustrate the complexity of the interactions of vit C in biological systems and indicate that with different concentrations vit C can cause or prevent genetic toxicity.

Genotoxic, cytostatic, antineoplastic and apoptotic effects of newly synthesized antitumour steroidal esters

In this study, we have investigated the genotoxic, cytostatic, antineoplastic and apoptotic effects of three newly synthesized modified steroidal esters, having as alkylating agent p-N,N-bis(2-chloroethyl) aminophenyl butyrate (CHL) or p-N,N-bis(2-chloroethyl) aminophenyl acetate (PHE) esterified with the steroidal nucleus modified in the B- and D-ring. The genotoxic and cytotoxic effects of the compounds were investigated both in vitro, in lymphocyte cultures obtained from blood samples of healthy donors and in vivo, in ascites cells of P388 leukemia obtained from the peritoneal cavity of DBA/2 mice. Preparations were scored for sister-chromatid exchange (SCE) and proliferation-rate indices (PRI). The newly synthesized compounds were also studied for antineoplastic activity against lymphocytic P388 and lymphoid L1210 leukemias in mice, by calculating the mean of the median survival of the drug-treated animals (T) versus the untreated control (C) (T/C%). The activity of caspase-2 and caspase-3, indicators of apoptosis, was assessed biochemically in primary cultures of human lymphocytes. Our results show that the newly synthesized compounds caused severe genotoxic effects by significantly increasing the frequency of SCE and decreasing the PRI values in cultures of peripheral lymphocytes in vitro and in ascites cells of lymphocytic P388 leukemia in vivo. A significant correlation was also observed in both the in vitro and in vivo experiments: the higher the SCE frequency the lower the PRI value (r=-0.65, P<0.001 and r=-0.99, P<0.01, respectively). The measured antileukemic potency was statistically increased by all test compounds in both types of tumours, while the activity of caspase-2 and caspase-3 showed a statistically significant increase after two periods of exposure. The genotoxic (increase of SCE), cytostatic/cytotoxic (decrease of PRI) and antileukemic effects (increase of T/C%) in combination with the induction of apoptosis (activation of caspase-2 and caspase-3) caused by the newly synthesized compounds, lead us to propose them as agents with potentially antineoplastic properties.

Chromosome instability in patients with chronic renal failure.

OBJECTIVE The aim of this study was to investigate the frequency of sister chromatid exchanges (SCEs), the presence of cytostaticity, cytotoxicity, and therefore, the possible genetic instability in patients with chronic renal failure (CRF) in human cultured peripheral blood lymphocytes. METHODS Peripheral blood lymphocytes were cultured from 32 patients with CRF (average 55.2 years) and 18 healthy blood donors (average 44.6 years), and the SCE method was applied afterward. The increase in SCE frequency was evaluated as an immediate DNA damage index, while the reduction in the values of the proliferating rate indices was evaluated as a cytostatic index and the mitotic indices as a cytotoxic index was also measured. RESULTS A significant increase in the SCE frequencies along with a significant reduction in mitotic indices was observed in patients with CRF compared with the controls. It is notable that there was no significant difference in SCE levels among patients with CRF and cancer, and patients with CRF alone. CONCLUSIONS This study illustrates increased genetic instability in patients with CRF. These results could also be of a great importance in early diagnosis to prognosticate a possible generation of neoplasm in the future.

The angiogenetic effect of intramuscular administration of b-FGF and a-FGF on cardiac muscle: The influence of exercise on muscle angiogenesis

Abstract Although angiogenetic therapy using recombinant growth factors holds much hope for the treatment of ischaemic diseases, there are still many unanswered questions, including the method of administration, the correct dose of these factors, and the duration of the therapeutic approach. Exercise has also been suggested to induce neovascularizaiton in muscles. We evaluated the angiogenetic effects of the intramuscular administration of basic-fibroblast growth factor (b-FGF) and acidic-fibroblast growth factor (a-FGF) in rat heart, compared with rats who exercised daily. In conclusion, both the intramuscular administration of b-FGF and exercise increased significantly angiogenesis in the heart in contrast to the intramuscular administration of a-FGF, which was ineffective.

Distribution of ABO and Rh blood groups in Greece: an update

The aim of this study was to investigate and evaluate the frequency of the antigens classifying the ABO and Rh blood groups in the Greek population. In this study the 3.5% were first generation immigrants with both their parents immigrants from countries of the USSR, while 1.2% had only one immigrant parent, while the other one was Greek. We compared the frequency of distribution of blood groups ABO and Rh to previous studies conducted at a time before Greece became destination for refugees and immigrants from East and Northeast countries. Blood samples were collected from first year medical students. The frequency of distribution of the ABO and Rh blood groups was slightly differentiated in comparison to previous relevant studies. Significant increase was recorded with respect to the emergence of blood group B in the population investigated, and a considerable reduction was noted in blood group O. In reference to the remaining blood groups, no statistically significant difference was documented. The genetic pool and the genetic inventory of the population residing in Greece have been modified during the last years potentially due to the first generation immigrants. The results of this study could contribute significantly to the National Health System in aiding the prediction of percussions of certain diseases related to blood groups, as well as the requirement for certain blood groups within the blood donation program.

Frequency of genetic diseases and health coverage of children requiring admission in a general pediatric clinic of northern Greece

BackgroundIn order to estimate the causes of pediatric morbidity in our area, with particular emphasis on diseases with a genetic background, we retrospectively categorized the admissions of all children hospitalized in the Department of Pediatrics of the University General Hospital of Alexandroupolis, in the area of Evros, Thrace, Greece over the three year period 2005-2007. Finally, in order to guide health care administrators to improve the delivery of pediatric health care services, we estimated the percentage of hospitalized children who were uninsured and the type of health insurance of those who had medical coverage.Patients and MethodsThe causes of admission, as recorded in the medical records were categorized in terms of the major organ and/or system involved and/or the underlying pathology, with emphasis on diseases with a genetic background. Duplicate admissions, i.e., admissions of the same child for the same underlying disease were excluded. Additional information recorded was age, sex, and type of health insurance of all admitted children. Distribution of the causes of admission by study year was compared by chi-square. A p value < 0.05 was considered significant.ResultsOver the study period, there were 4,947 admissions in 2,818 boys and 2,129 girls. Respiratory diseases were the most common accounting for 30%, while infectious diseases followed with 26.4%. The frequency of chromosomal abnormalities among the hospitalized children was only 0.06%. However, if we consider diseases with an underlying genetic background, this percentage rises to 5%. Approximately 10.3% of the admitted children had no health insurance.ConclusionsThe percentage of children hospitalized in our area due to a disease with an underlying genetic background was 5%. This percentage pertains to a Department of Pediatrics that has no inpatient subspecialty units and which is located within a General hospital, because hospitalizations for genetic diseases are more frequent in specialized pediatric hospitals, with competence in clinical genetics. The double figure of uninsured children is worrisome and dictates the need for governmental efforts for universal pediatric health coverage in our country.

Cytogenetic and antineoplastic effects of modified steroidal alkylators.

INTRODUCTION The aim of this study was to design new potentially antineoplastic agents by combining nitrogen mustard with steroidal skeleton, in an effort to improve specificity and simultaneously to reduce systemic toxicity. The steroidal part is aimed to act as a biological platform enabling the alkylating moiety to approach its site of action by altering its physicochemical properties. MATERIALS AND METHODS The compounds tested have, as alkylating agents, either p-N,N-bis(2-chloroethyl)aminophenyl-butyrate or p-N,N-bis(2-chloroethyl)aminophenyl-acetate esterified with a modified steroidal nucleus. The four newly synthesized compounds were compared on a molar basis, regarding their ability to induce sister chromatid exchanges and modify proliferation rate indices in cultured human lymphocytes. Life span of BDF1 mice inoculated with L1210 leukemia was also estimated (antileukemic activity). RESULTS A compound having p-N,N-bis(2-chloroethyl)aminophenyl-acetate as the alkylator and two ketone groups in the steroidal part demonstrated the highest statistically significant enhancement of sister chromatid exchanges and suppression of proliferation rate indices, and also caused significant antineoplastic activity. The other compounds proved less active. CONCLUSION These results suggest that cytogenetic and antileukemic activity of alkylating steroidal esters depends on the configuration of the whole molecule and the appropriate combination of the alkylator with the steroidal molecule.