The contribution of the mouse spermatid micronucleus assay to the detection of germinal mutagens.
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Aneuploidy↗
Biomedical subjects
A Russo
Publications and source records attributed to A Russo.
Structural and ultrastructural study of the ovary in childhood leukemia after successful treatment.
Ovarian biopsy specimens from ten girls (three postmenarcheal) who had undergone antiblastic treatment for acute lymphoblastic leukemia (ALL) and were in complete remission were examined by light microscope. The biopsy specimens from four of these patients (three postmenarcheal) were also observed by electron microscope. The structural and ultrastructural analysis showed a reduction in the number of follicles which were otherwise normal. No follicles were found in the thin sections from two of the three postmenarcheal girls, whereas normal follicles were observed in the third. The cortical stroma showed moderate to severe signs of fibrosis and changes of capillaries. All of these alterations were more evident in patients where ALL was diagnosed at an older age and this finding suggests that they are at a higher risk for low fertility or early menopause.
Acute Disease↗
Sensitivity of different human lung cancer histologies to photodynamic therapy.
The relative sensitivities of different cancer histologies in a single site to photodynamic therapy (PDT) are unknown and methods to predict PDT sensitivity have not been described. The in vitro response to PDT of six established human lung cancer cell lines and one normal lung fibroblast cell line was studied using the clonogenic assay. Dose-response curves were determined for cells incubated in 25 micrograms/ml of Photofrin II for 2 h, followed by exposure to 630-nm light to total energies of 0-3150 J/m2. None of the cell lines were sensitive to sensitizer alone or light alone. Differences in inherent PDT sensitivities as evaluated by survival curve parameters n, Do, and light dose to yield 1% survival were observed among the cell lines. No clear correlation was found when inherent PDT sensitivity was compared with sensitizer uptake; however, a general association was noted between PDT sensitivity and the plating efficiency of the cell line. These data illustrate that differences in inherent PDT exist for in vitro systems. Such differences may explain some of the failures seen in clinical PDT.
Cell Line↗
Increase of plasma beta endorphins in vasodepressor syncope.
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Adolescent↗
Biologically active metal-independent superoxide dismutase mimics.
Superoxide dismutase (SOD) is an enzyme that detoxifies superoxide (O2.-), a potentially toxic oxygen-derived species. Attempts to increase intracellular concentrations of SOD by direct application are complicated because SOD, being a relatively large molecule, does not readily cross cell membranes. We have identified a set of stable nitroxides that possess SOD-like activity, have the advantage of being low molecular weight, membrane permeable, and metal independent, and at pH 7.0 have reaction rate constants with O2.- ranging from 1.1 x 10(3) to 1.3 x 10(6) M-1 s-1. These SOD mimics protect mammalian cells from damage induced by hypoxanthine/xanthine oxidase and H2O2, although they exhibit no catalase-like activity. In addition, the nitroxide SOD mimics rapidly oxidize DNA-FeII and thus may interrupt the Fenton reaction and prevent formation of deleterious OH radicals and/or higher oxidation states of metal ions. Whether by SOD-like activity and/or interception of an electron from redox-active metal ions they protect cells from oxidative stress and may have use in basic and applied biological studies.
Animals↗
Vinblastine and interferon-alpha-2a regimen in the treatment of metastatic renal cell carcinoma.
Thirteen patients with histologically proven advanced and/or metastatic renal cell carcinoma (RCC) were treated with vinblastine (Velbe, Eli Lilly, Sesto Fiorentino, Italy) and interferon-alpha-2a (Roferon-A, Roche, Milan). Eleven out of 13 patients were evaluable. Eighteen percent of patients had partial response, 46% stable disease (SD), and 36% progressive disease (PD). The mean survival of responders was 228+ days, whereas the patients showing SD and PD had a mean survival of 154+ and 107+ days respectively. Toxicity, including influenza-like syndrome, fever, neurological and gastrointestinal side effects, was generally mild. However, medication with paracetamol was required in 82% of cases. Our small study confirms that VBL and IFN-2a regimen is moderately active in RCC.
Adult↗
A concerted approach to the study of the aneuploidogenic properties of two chelating agents (EDTA and NTA) in the germ and somatic cell lines of Drosophila and the mouse.
The genetic effects of nitrilotriacetic acid (NTA) and ethylenedinitrilotetraacetic acid (EDTA), two widely used chelating agents, were investigated by using a somatic mutation and recombination test (SMART) after treatment of larvae and the FIX test for aneuploidy after treatment of adult female Drosophila melanogaster. Chloral hydrate (CH) and 5-fluorodeoxyuridine (FdUr) were used as positive controls. Effectively absorbed amounts of the test compounds assayed in Drosophila were estimated at the single fly level by a method using 3H-leucine. NTA and EDTA were also assayed in tests for aneuploidy based on chromosome counting in mouse germ and somatic cells. We previously showed that NTA was able to induce aneuploidy (chromosomal gain) in the germ cells of both Drosophila and the mouse when tested at the exposure levels of 5 x 10(-2) M and 275 mg per kg body weight, respectively [Costa et al., Environ Mol Mutagen 12:397-407, 1988]. In the present experiments, EDTA was assayed at 2.5 x 10(-2) M and 7.5 x 10(-3) M in the FIX test adopting a three-stage brooding scheme. Significant increases (with respect to controls) in chromosomal loss were observed in the second brood and in the combined three-brood total for both exposure levels of EDTA. In the SMART test, treatments with EDTA in the same exposure range produced negative results over all end-points, whereas significant increases in the frequency of small single spots (possibly due to aneuploidy) were produced by NTA 5 x 10(-2) M. In the cytogenetic assays for aneuploidy both in the germ and somatic cells of the mouse, negative results were also obtained following the i.p. administration of 93 and 186 mg EDTA per kg b.w. The previously observed induction of germ cell aneuploidy by NTA (275 mg per kg b.w.) was confirmed in the present experiments on a different strain of mice. NTA (138-275 mg per kg b.w.) did not induce aneuploidy in somatic cells of the mouse [Russo et al., Mutat Res 226: 111-114, 1989], however. These results are compared and discussed with reference to the characteristics of the different test systems used and to the different chelating properties of NTA and EDTA.
Acetates↗
SOD-like activity of 5-membered ring nitroxide spin labels.
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Animals↗
Local hyperthermia for treatment of advanced prostatic carcinoma: preliminary results.
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Adolescent↗
Segregation analysis of 1885 DMD families: significant departure from the expected proportion of sporadic cases.
The proportion of sporadic cases of Duchenne muscular dystrophy has been estimated by classical segregation analysis in a pooled sample of 1885 sibships from 7 different countries. A significant departure from the theoretical expectations based on mutation-selection equilibrium is observed (segregation frequency = 0.439 +/- 0.017; frequency of sporadic cases = 0.229 +/- 0.026, at the maximum likelihood). The occurrence of germinal mosaicism in some of the mothers of Duchenne cases may account for this peculiar finding, although a possible role of inequality of mutation rates in the two sexes cannot be ruled out.
Chromosomes, Human↗
Origin of aneuploidy in relation to disturbances of cell-cycle progression. I. Effects of vinblastine on mouse bone marrow cells.
Vinblastine (VBL) was tested in the mouse for induction of chromosome malsegregation in bone marrow cells. The occurrence of aneuploidy and polyploidy was correlated with cell-cycle kinetics measured by DNA labelling with bromodeoxyuridine (BrdUrd). Sister-chromatid exchanges (SCE) were also detected. A dose-dependent lengthening of the cell cycle was induced in the dose range of 0.9-4.5 mg/kg body weight, up to a complete inhibition of cell-cycle progression (100% of metaphases were arrested before completion of the first mitotic division following a recovery time of 18 h, compared with 8% in the controls). Both aneuploidy and polyploidy were induced. Aneuploid metaphases were grouped into 2 classes, those with no more than 2 extra chromosomes and those with 3-10 extra chromosomes. The frequencies of cells with severe aneuploidy and polyploidy increased considerably when second-generation cells were sampled at a recovery time of 24 h. This observation suggested that gross chromosome imbalances occur preferentially after a period of mitotic arrest, probably as a consequence of multipolar spindles or failure of proper spindle assembly. Non-disjunction of single chromosomes arises independently of the mitotic block. A slight increase in SCE frequency was observed only at a recovery time of 18 h. This study may provide information on the kinetics and mechanisms of origin of VBL-induced numerical aberrations in vivo.
Analysis of Variance↗
The impact of whole-abdomen radiotherapy on survival in advanced ovarian cancer patients with minimal residual disease after chemotherapy.
Between March 1982 and March 1987, 26 patients with minimal residual epithelial ovarian cancer after cisplatin-based chemotherapy were treated with whole-abdomen irradiation [moving-strip technique (MST)] with or without pelvic boost. Prior to radiation residual disease was macroscopic (less than or equal to 0.5 cm) in 8 cases and microscopic (positive random biopsies) in 18 cases (8 diffuse, 10 localized). Eighty percent of patients completed the planned therapy, 34% with interruptions secondary to hematologic or gastrointestinal toxicity. With a median follow-up time from completion of radiotherapy of 24 months, 34.6% of patients remain alive. The 3-year survival rates (from the second-look procedure) are 50% for the patients with microscopic tumor and 25% for those with macroscopic residual disease. Progression-free intervals are statistically different in the two groups: 16.9 months for microscopic residuals and 6.16 months for macroscopic tumors (P = 0.037). All but two of the recurrences were in the irradiated field (pelvis and/or abdomen); one was distant (pleural) and one only retroperitoneal. Small bowel injury was the most limiting complication: 3.8% was registered as fatal acute enteritis and 19% as late obstruction or malabsorption syndrome, necessitating surgical intervention in 10% of treated cases.
Biopsy↗
Misonidazole hypoxic cytotoxicity and chemosensitization in two cell lines with different intracellular glutathione levels.
Nitroimidazoles such as misonidazole (Miso) or SR-2508 are known to be cytotoxic to hypoxic cells and, with preincubation under hypoxic conditions, to sensitize cells to certain chemotherapy drugs, notably melphalan. In addition, these nitroimidazoles afford hypoxic radiosensitization; however, high intracellular glutathione (GSH) levels have been shown to significantly reduce radiosensitization by some nitroimidazoles. Using two cell lines that have an 8-fold difference in cellular GSH content, we have investigated whether inherent GSH levels influence Miso-induced hypoxic cytotoxicity, hypoxic GSH depletion, or chemosensitization to melphalan. Hypoxic incubation with varying concentrations of Miso resulted in greater cytotoxicity in Chinese hamster V79 cells than in A549 human lung adenocarcinoma cells, which have much higher GSH levels. However, the rate of GSH depletion for three concentrations of Miso was the same in the two cell lines, despite the large difference in inherent GSH levels. While the inherent sensitivity to melphalan was markedly different between the cell lines, hypoxic preincubation with 2 mM Miso with subsequent aerobic exposure to melphalan resulted in similar levels of sensitization. These results indicate that the potentiation of melphalan cytotoxicity by hypoxic Miso preincubation can occur independent of intracellular GSH levels.
Animals↗
Fluorescent detection of rabbit endometrial implants resulting from monodispersed viable cell suspensions.
A model for early stage endometriosis was prepared in rabbits by intraperitoneal injection of monodispersed viable endometrial cells. With this model, we have found that DHE fluorescence increases the sensitivity of detection of endometrial tissue. The potential experimental and clinical significance of ectopic endometrial detection by porphyrin fluorescence is enhanced by the recent report of endometrial transplant destruction by PDT. Although caution must be exercised for extrapolation from animal experiments to human conditions, these results encourage further evaluation of photosensitization for the study and potential treatment of disorders involving endometrial tissue.
Animals↗
Oral tegafur in the treatment of gastrointestinal tract cancers: a phase II study.
Fifty patients affected by histologically confirmed gastrointestinal tract cancer (GTC) were treated with oral tegafur (TG) 1,000 mg m-2 p.o. on days 1-14 repeated after a 14 day interval. Out of 42 evaluable patients seven patients had a partial response (PR. 17%) with a median duration of 20.5 weeks, three had a minimal response (7%) with a median duration of 23.7 weeks, nine showed a stabilisation which lasted a median of 31.3 weeks, and 23 progressed (55%). No response was obtained in patients affected by carcinoma of the pancreas and the hepatobiliary system. All PRs were achieved in patients with metastatic disease to the liver. No response was seen in patients with bone, lung or nodal metastasis. Three PRs were obtained in patients resistant to 5-fluorouracil. The difference in survival between patients who achieved PR and those who had a stabilisation was not statistically significant. On the other hand the survival of patients with PR was significantly longer than that of patients who progressed. Oral TG was well tolerated by most patients. WHO grade 1-2 gastrointestinal and neurological toxicities were seen respectively in 36% and 25% of cases. Five patients had grade 3 nausea/vomiting and one had grade 3 diarrhoea. Our data suggest that oral TG is effective in the treatment of stomach and colorectal cancers.
Administration, Oral↗
Reconstitution of simian virus 40 DNA replication with purified proteins.
Replication of plasmid DNA molecules containing the simian virus 40 (SV40) origin of DNA replication has been reconstituted with seven highly purified cellular proteins plus the SV40 large tumor (T) antigen. Initiation of DNA synthesis is absolutely dependent upon T antigen, replication protein A, and the DNA polymerase alpha-primase complex and is stimulated by the catalytic subunit of protein phosphatase 2A. Efficient elongation of nascent chains additionally requires proliferating cell nuclear antigen, replication factor C, DNA topoisomerase I, and DNA polymerase delta. Electron microscopic studies indicate that DNA replication begins at the viral origin and proceeds via intermediates containing two forks that move in opposite directions. These findings indicate that the reconstituted replication reaction has many of the characteristics expected of authentic viral DNA replication.
Antigens, Polyomavirus Transforming↗
A phase I-II study on the toxicity and therapeutic efficacy of 5-fluorouracil in combination with leucovorin and cisplatinum in patients with advanced colorectal carcinoma.
5-Fluorouracil (5-FU) has been the treatment of choice for colorectal carcinoma with an overall response rate of about 20%. Recent studies have shown that folate (LV) can increase 5-FU therapeutic efficacy, achieving about a 40% response rate without a clear impact on survival. Cisplatinum (CDDP) is usually inactive in colorectal carcinoma, but the association with 5-FU results in a synergistic antineoplastic effect. A phase I-II study was done to assess the maximally tolerated dose (MTD) of CDDP in association with 5-FU + LV. The MTD for CDDP was 20 mg/m2/wk in association with 5-FU 400-500 mg/m2/wk and LV 500 mg/m2/wk. WHO criteria were used for evaluation of both toxicity and response. In the phase I part we found that the main side-effect in 27 evaluable patients (pts) was gastrointestinal toxicity, mainly in the form of nausea/vomiting (92%) and diarrhea (70%) which caused one therapy-related death. Renal (26%) and marrow (59%) toxicity were acceptable. In the phase II part of the study 1 out of 19 evaluable pts (5%) had a complete response of 309 days, 3 pts achieved a partial response (16%) with a median duration od 410 days, 2 pts had a minimal response (10%) with a median duration of 261 days, and 8 pts experienced no change (42%) with a mean duration of 196 + days. In our opinion the 21% response rate obtained in this series is not satisfactory. Nevertheless the very high number of minimal response + no change patients together with the interesting impact on survival in responders may suggest further phase II-III studies.
Adult↗
Protection by indomethacin against acute radiation esophagitis.
The mechanism of radiation induced damage to the mucosal lining of the gastrointestinal tract, as well as mucositis, is not fully characterized. Prostaglandins may partially mediate the inflammatory response to radiation damage. The effect of the prostaglandin synthetase inhibitor indomethacin on radiation induced esophagitis, pneumonitis, and tumor response was evaluated in the C3H mouse. The effects of indomethacin on radiation induced damage to the esophagus was determined by evaluation of weigh lost, survival, and histologic findings at doses of 28-34 Gy. Although there is a clear difference that supports the use of indomethacin for the prevention of esophagitis, the radiation dose response for esophagitis is steep and likewise, the therapeutic index for the indomethacin amelioration of radiation esophagitis is narrow. Since the tumor response to radiation is unchanged and since indomethacin clearly lessens radiation induced esophagitis in the mouse, this study suggests that indomethacin should be studied in humans for lessening radiation mucositis without jeopardizing the therapy of tumors.
Acute Disease↗