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M Spanò

Publications and source records attributed to M Spanò.

47 records · Page 3Linked to original sources
PubMed1987

Flow cytometric analysis of the effects of 0.4 MeV fission neutrons on mouse spermatogenesis.

(C57Bl/Cne X C3H/Cne)F1 male mice were irradiated with single acute doses of 0.4 MeV neutrons ranging from 0.05 to 2 Gy, and testis cell suspensions were prepared for cytometric analysis of the DNA content 2-70 days after irradiation. Various cell subpopulations could be identified in the control histogram including mature and immature spermatids, diploid spermatogonia and spermatocytes, tetraploid cells and cells in the S-phase. Variations in the relative proportions of different cell types were detected at each dose and time, reflecting lethal damage induced on specific spermatogenetic stages. The reduction of the number of elongated spermatids 28 days after irradiation was shown to be a particularly sensitive parameter for the cytometrical assessment of the radiosensitivity of differentiating gonia. A D0 value of 0.13 Gy was calculated and compared with data obtained after X-irradiation, using the same experimental protocol. In the latter case a biphasic curve was obtained over the dose range from 0.25 to 10 Gy, possibly reflecting the existence of some cell population heterogeneity. RBE values were estimated at different neutron doses relative to the radiosensitive component of the X-ray curve, and ranged from 3.3 to 4, in agreement with data in the literature. Genotoxic effects were monitored 7 days after irradiation by a dose-dependent increase of the coefficient of variation (CV) values of the round spermatid peak, reflecting the induction of numerical and structural chromosome aberrations, and 14 or 21 days after irradiation by the detection of diploid elongated spermatids, probably arising from a radiation-induced complete failure of the first or second meiotic division.

Animals↗
PubMed1986

Considerations in the design of possible cell cycle effective drugs.

Antineoplastic agents are known to induce differential cytotoxic and cytostatic effects throughout the cell cycle. Many drugs have greater toxicity for cycling cells and act selectively at one or more phases of the cycle and may cause partial synchrony of surviving cells. However, these observations have been generally carried out on in vitro systems only and present a variety of complexities and pitfalls. Furthermore, human tumours are often characterized by a relatively low fraction of proliferating cells and present a large cellular heterogeneity as far as their cytogenetic, cytokinetic, and clonogenic features and their responses to drugs are concerned. Therefore, resistance to chemotherapy is due to various factors characterizing, in some instances, each individual tumour. In spite of the advent of technological advances such as flow cytometry, it is still difficult to design kinetic-orientated therapies especially for the treatment of solid tumours. Consequently, it is also difficult to design protocols based on cell cycle effective drugs. The possibility remains, at least for the moment, to stratify tumours according to their cellular heterogeneity. Different protocols could then be assigned to classes of tumours. Such an approach could be completed by further advances in the cellular monitoring of individual tumours.

Alkylating Agents↗
PubMed1984

Analysis of DNA synthesis rate of cultured cells from flow cytometric data.

The rate of DNA synthesis along S phase is estimated from flow cytometric histograms on the basis of a mathematical model of a cell population. In the absence of loss, the model expresses the population kinetics in terms of DNA synthesis rate, S-phase influx, and population size. A single histogram is sufficient to determine the DNA synthesis rate when the population is in balanced exponential growth. Two suitably chosen histograms are necessary if the S-phase influx is exponential in a time interval longer than the S-phase duration. The analysis procedure was tested on published autoradiographic data and applied to three cultured cell lines (CM-S, 3LL, and M14 cells) that show various patterns of DNA distribution. In each case the cell-cycle fractions, the DNA synthesis rate, and the S-phase duration were obtained.

Animals↗
PubMed1980

Multiple daily fractionation (MDF) radiotherapy in association with hyperthermia and/or misonidazole: experimental and clinical results.

Several modalities involving a Multiple Daily Fractionation (MDF) course in combination with hyperthermia and/or the hypoxic sensitizer misonidazole have been tested on a mouse tumor system and then applied, with the proper sequencing, to a group of patients with multiple (N2-N3) neck node metastases from H&N cancers. Different lesions of the same patients underwent different modalities. The clinical results indicate the effectiveness, in respect to a historical series of patients treated with conventional fractionation (200 rads/day, five days/week), of either MDF alone (200 + 150 + 150 rads/day, five days/week) or MDF + hyperthermia (500 MHz, 42-43 C, 45 min., after 2nd daily fraction, on day 1, 3, and 5 of each week) or MDF + misonidazole (1.2 g/m2 daily, 2 hours before 1st fraction, up to a maximum dose of 12 g/m2), or MDF + hyperthermia + misonidazole. The latter modality appears to be possibly the most effective at inducing a complete local tumor response lasting longer in time (follow-up to a minimum of four months). The pharmacology of misonidazole has been monitored in the patients to avoid undesired excessive drug plasma level. No neurological symptoms have been observed. Oropharyngeal mucositis has been observed only in patients treated with misonidazole and radiation through two cross-firing portals. The problem of selecting individual patients for a particular modality is discussed.

Animals↗
PubMedDate not supplied

Autosomal recessive congenital cerebellar atrophy. A clinical and neuropsychological study.

Congenital cerebellar atrophy associated with a non-progressive cerebellar syndrome and mild cognitive retardation is described in seven cases, four of them familial. Their occurrence is consistent with an autosomal recessive inheritance. Clinical and neuroimaging data seem to exclude supratentorial changes. Even though it is not possible to definitely rule out a possible role of the forebrain in determining the mental defect, the neuropsychological study supplies arguments stressing the relationship between cerebellar defect and cognitive development.

Acoustic Stimulation↗
PubMedDate not supplied

A longitudinal study of semen quality in pesticide spraying Danish farmers. The ASCLEPIOS Study Group.

It was hypothesized that occupational exposure to pesticides during a spraying season causes changes in semen quality that might be detected in a longitudinal study. We analyzed the within-person changes in semen quality and reproductive hormones across a spraying season in groups of farmers using and not using pesticides. A total of 248 men collected two semen samples (participation rate: 32%). The median sperm concentration declined significantly from the first to the second sample in both groups, but there was no statistical difference in the decline between the two groups, unadjusted or adjusted. Only minor changes were found in sperm morphology, vitality, motility, sperm chromatin denaturation (SCSA), and reproductive hormones, and the differences in changes between the two groups were nonsignificant, or, in the opposite direction to the expected. There was no relation between the changes in sperm parameters in relation to pesticide exposure variables. In conclusion, use of pesticides by Danish farmers is not a likely cause of short-term effects on semen quality and reproductive hormones.

Adolescent↗
PubMedDate not supplied

Effects of L-acetylcarnitine (LAC) on the post-injury recovery of mouse spermatogenesis monitored by flow cytometry. 2. Recovery after hyperthermic treatment.

It has been demonstrated that L-acetylcarnitine (LAC) can enhance the recovery of spermatogonial cells after X-ray damage. In the present work, the effects of LAC on the recovery processes of mouse spermatogenesis after local acute hyperthermia (42 degrees C, 1 hour) was investigated. LAC was administered i.p. (100 mg/kg body weight) every other day for four weeks after heat treatment. At intervals of 8, 14, 21, 28, 35, 40, 45, and 60 days after hyperthermic treatment, testes were weighed and their DNA content analysed by flow cytometry; the round spermatid fraction was found to be higher at 45 days in the LAC-treated animals than in controls (P less than 0.01). Correspondingly, at the same experimental point, the animals without LAC administration showed a lower testicular weight (P less than 0.05). Combined with histological analysis, these results suggest a more rapid recovery of normal spermatogenesis after physical insult with LAC treatment.

Acetylcarnitine↗
PubMedDate not supplied

Flow cytometric and immunohistochemical correlations in high incidence human solid tumors.

475 patients with carcinoma at different sites (141 colon-rectum; 102 breast; 50 stomach; 48 kidney; 46 head and neck; 41 bladder; 47 other sites) submitted to surgery have been analyzed after histopathological staging and grading, by flow cytometry (monoparametric DNA content analysis) and immunohistochemistry (p53, c-erbB-2, and PCNA expression). In breast cancer patients the presence of receptors for estrogen (ER) and progesterone (PGR) has also been determined. Flow cytometry-derived parameters were DNA ploidy, fraction of cells in S-phase (SPF), and DNA content heterogeneity (multi-clonal stem cell lines with different DNA index and/or more than one subpopulations with different ploidy levels in different samples from the same tumor). Correlations of the results obtained by the different techniques have been attempted by the non-parametric Spearman's rank correlation approach. Significant associations (P < 0.05) were found between the histopathological, immunohistochemical and flow cytometric parameters considered in some anatomical regions, such as stomach (p53 vs DNA content aneuploidy and vs heterogeneity), colon-rectum (TNM vs p53 and vs heterogeneity), bladder (grading vs DNA content aneuploidy and vs heterogeneity). Tumor heterogeneity proved to be dependent on the number of tumor samples taken. The results of this preliminary assessment will subsequently be compared with the data obtained from a currently ongoing follow-up survey.

DNA, Neoplasm↗
PubMedDate not supplied

Orgotein as a radioprotector in normal tissues. Experiments on mouse skin and a murine adenocarcinoma.

The effects of Orgotein (a superoxide dismutase) on the radiation response of normal and malignant murine tissue in vivo were evaluated. The observations were made on the mouse hind leg bearing, in some cases, an adenocarcinoma. The following irradiation protocols were tested: 1) single dose (e.g., 35 and 53 Gy), 2) conventional fractionation (3 Gy/day, 5 days a week) and 3) multiple fractions per day (2 X 3 Gy/day, 3 h fractionation interval, 5 days a week). Radiation was either delivered alone or preceded by a subcutaneous injection of 20, 100 or 400 mg/kg Orgotein administered 1 or 2 h before the beginning of irradiation. No effects of Orgotein on tumor radiation response were detected. A protective effect on normal tissue was observed when radiation was delivered according to aggressive protocols and a relatively high dosage of Orgotein was administered. Furthermore, an accelerated trend of recovery of normal tissue was observed.

Adenocarcinoma↗
PubMedDate not supplied

Effects of L-acetylcarnitine (LAC) on the post-injury recovery of mouse spermatogenesis monitored by flow cytometry. 1. Recovery after X-irradiation.

L-acetylcarnitine plays a key role in sperm metabolism and in the whole spermatogenetic process. In the present work, the influence of L-acetylcarnitine, administered i.p. (100 mg/kg body weight), on the recovery processes of mouse spermatogenesis after local acute irradiation with 10 Gy X-rays has been investigated. The effects were monitored 28, 35, 40, 45, 50, 55, and 60 days after irradiation by flow cytometric analysis of cellular DNA content. In the LAC-treated animals, the fraction of tetraploid cells is higher at 28 (p less than 0.05) and 45 days (p less than 0.02). Corresponding with the timing of the stages of murine spermatogenesis, the round spermatid fraction is higher at 45 days (p less than 0.1) and the elongated spermatid fraction is higher at 50 days (p less than 0.1) after irradiation. In addition, the LAC-treated animals show a faster recovery throughout the maturation process, from tetraploid to round and elongated spermatids. These results indicate that the presence of exogenous LAC could enhance the recovery of spermatogonial cells.

Acetylcarnitine↗