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Biomedical subjects

F Mauro

Publications and source records attributed to F Mauro.

At least 91 records · Page 5Linked to original sources
PubMed1969

Variations in sulfhydryl, disulfide, and protein content during synchronous and asynchronous growth of HeLa cells.

The cellular contents of protein-bound and nonprotein sulfhydry (-SH) and disulfide (-SS-) groups were measured in both asynchronous and synchronous HeLa S3 cultures. About 90% of these groups are associated with proteins, the majority in the -SH form. The content of protein-bound groups, and hence the total content of -SH and -SS- groups (28 x 10(-15) moles/cell, or 1.1 x 10(-6) moles/g protein on average), changes in parallel with the protein content (which varies between 2 and 4 x 10(-10) g/cell) as asynchronous populations pass from the lag through the exponential to the stationary phase of growth. The concentration of nonprotein -SH groups, in contrast, increases 10-fold during lag phase and decreases in stationary phase; it follows the protein concentration closely during the exponential phase, at a level of about 2.8 x 10(-15) moles/cell. In synchronous cultures the protein content doubles during the cell cycle, possibly in an exponential fashion. The total -SH and -SS- content also doubles, but the rate of increase appears to fluctuate. The concentrations of the protein-bound groups show 2- to 3-fold fluctuations per unit protein: protein-bound -SH groups and mixed -SS- linkages rise to maxima while protein-bound -SS- groups fall to a minimum at the G(1)/S transition, and fluctuations in these groups occur again during G(2). In addition, the protein-bound -SH concentration falls continuously during the S phase. The nonprotein -SH concentration undergoes the largest (relative) fluctuations, dropping from 4 x 10(-15)moles/cell in early G(1) to about 0.4 x 10(-15) moles/cell (of standard protein content) at the end of G(1), and then rising to 30 times this value by the end of S.

Arginine↗
PubMed1969

Age response to x-radiation of murine lymphoma cells synchronized in vivo.

Cells of a transplantable murine lymphoma line were partially synchronized in vivo by administration of a single dose of 0.5 mg of hydroxyurea per lymphoma-bearing mouse. At various times after administration of hydroxyurea, the femurs of the lymphomatous mice were X-irradiated, and the number of lymphoma colony-forming units per femur were then assayed by the spleencolony technique. A well-defined age response to irradiation of the lymphoma cells in vivo, similar to that of HeLa cells in vitro, was observed.

Aging↗
PubMed1967

Sulfur mustard and x-rays: differences in expression of lethal damage.

Before or after treatment with sulfur mustard, simple changes in the incubation conditions of cultured Chinese hamster cells lead to changes as great as a factor of 6 in survival-curve slopes. With x-ray treatment, changes are similar but much smaller in magnitude. These results suggest that the modes of action of these agents are not entirely the same.

Animals↗
PubMedDate not supplied

Changes of phenotypic characteristics of variants derived from Lewis lung carcinoma during long-term in vitro growth.

Two cultured cell clones derived from Lewis lung carcinoma (3LL), which have been shown to differ in their metastatic potential, were studied for their phenotypic stability in vitro. Several growth properties (lag-phase duration, doubling time, saturation density, cell shedding, plating efficiency) have been monitored for more than three years. The ability to induce primary tumors and metastasis, together with the response of cultured cells to adriamycin and bleomycin, have also been evaluated over the same period. The results show that the pattern of metastatic heterogeneity of the two clones is maintained during the serial passages in vitro, although the most actively metastatic clone (C108) displayed a reduced lung colony-forming ability at late passages. Furthermore, both clones exhibited an increasing sensitivity to adriamycin, while no changes were observed in the response to bleomycin. The present data suggest a phenotypic instability of tumor clones adapted to tissue culture conditions and, in particular, that the inherent chemosensitivity of tumor cells may change during long-term culture.

Animals↗
PubMedDate not supplied

Association of near-diploid DNA content and N-myc amplification in neuroblastomas.

Seventeen neuroblastomas at different clinical stages were analysed for their N-myc copy number and flow cytometrically determined DNA content. Aneuploidy was found in 11 patients (65 per cent), whereas the remaining were near-diploid. N-myc amplification was found significantly (P less than 0.05) confined to near-diploid tumors (3 out of 6 cases). This finding indicates a very selective mechanism of oncogene amplification which is independent of gross chromosomal imbalance and limited to specific loci in the human genome. Association of near-diploidy and age at diagnosis older than 24 months was also demonstrated (P less than 0.05). Thus, flow cytometric analysis of DNA content together with N-myc gene dosage allowed us to distinguish two different subsets of neuroblastoma tumors: the first one aneuploid, with single-copy N-myc, usually observed in patients younger than 24 months with localized or IV-S clinical stages; the second one near-diploid, with frequent N-myc amplification, usually observed in patients older than 24 months with advanced clinical stages.

Child↗
PubMedDate not supplied

Health status and internal radiocontamination assessment in children exposed to the fallout of the Chernobyl accident.

The Chernobyl fallout caused release of radioisotope contaminants in a very large area that includes Belarus, the Ukraine, and the Russian Federation. In this study, the authors monitored the health status and level of internal contamination in 422 children who resided in the aforementioned areas and who were < or = 10 y of age at the time of the accident. The children came to Italy for a 1-mo period between 1991 and 1992. During this time, the children underwent pediatric checkups and biochemical, immunological, and thyroid analyses. All children underwent whole-body counter measurements, and urine radiotoxicological analysis was performed for 224 of them. The 24 children evacuated from Pripiat, a village very close to the Chernobyl reactor site, were selected for cytogenetic analysis. All of these children continue to have a detectable internal contamination of caesium radioisotopes. This condition is likely the result of ground and foodstuff contamination in the various areas. The children did not evidence overt pathologies related to ionizing radiation. However, minor alterations in immunological and thyroid parameters were observed in the group of the evacuated children. Traditional cytogenetic dosimetry was not possible, but the occurrence of acentric fragments was observed-indicating a persistent effect of continuous exposure to low doses of radiation.

Adolescent↗
PubMedDate not supplied

Flow cytometry and sizing for routine andrological analysis.

Flow fluorometry and Coulter type sizing analysis of sperm have been applied separately in order to improve human semen analysis. Different methods of sample preparation were evaluated and a protocol involving prestaining pepsin treatment of sperm samples is proposed for fluorometric analysis. The data obtained with fluorometry and sizing analysis result in different kinds of information: Coulter counting allows to automate sperm counting and fluorometry yields more detailed information about normozoospermia and oligozoospermia by determining the proportion of mature spermatozoa and immature germ-cells. These two methods, together with light microscopy, may help to explore the correlation of fertility and pathology of spermatozoa. The aim of these investigations is to yield the preconditions for simultaneous two-parameter analysis of DNA content and cellular size distributions.

DNA↗
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

Insulinlike growth factor 1 in controls and growth-retarded fetuses.

OBJECTIVES: To establish a reference range of insulinlike growth factor 1 (IGF-1) values in normal fetuses and to assess whether intrauterine growth retardation is associated with increased or decreased IGF-1 levels. METHODS: Retrospective analysis of blood samples collected from 64 fetuses who underwent blood sampling at 18-38 weeks' gestation was performed: 40 fetuses, who were considered controls, were appropriately grown for gestational age and were found unaffected by the condition for which they were tested; the remainder (n = 24) underwent fetal blood sampling to assess fetal karyotype and acid-base balance following ultrasonic diagnosis of intrauterine growth retardation. (In this group, 8 survived, and 16 died during the perinatal period). IGF-1 was measured using a radioimmunoassay after acid-ethanol extraction in order to avoid interference by the binding proteins. All samples from controls and growth-retarded fetuses were measured using the same batch, and the intra-assay coefficient of variation of the test ranged from 4.1 to 6.1%. RESULTS: In control fetuses, IGF-1 serum levels increased linearly with gestational age. In growth-retarded fetuses, IGF-1 levels were not significantly different from the reference range (median Z-score -0.3; range -4.4 to 291) and did not correlate with fetal size, hematocrit, and acid-base balance values. There was a significant difference in IGF-1 and pH values when the fetuses were divided into two groups based on the perinatal outcome: those who survived had values of IGF-1 mostly within the normal range, whereas the fetuses who died in utero or postnatally had significantly decreased pH and elevated IGF-1 values (median Z-score 2.1; 95% confidence interval 0.4-13.9; p = 0.04). CONCLUSIONS: This study confirms previous observations that IGF-1 levels parallel the increase in fetal size which occurs with advancing gestation. Increased levels of IGF-1 may indicate a terminal process in the fetal adaptation to placental failure.

Case-Control Studies↗
PubMedDate not supplied

Tumour response to heat and radiation: prognostic variables in the treatment of neck node metastases from head and neck cancer.

A total of 38 patients with 81 multiple neck node metastases from squamous cell carcinoma of head and neck were treated with radiotherapy alone or with radiotherapy plus hyperthermia. Irradiation was delivered following a three fractions per day schedule of 2 + 1.5 + 1.5 Gy/day, with 4 h intervals between fractions, up to a total dose of 60 Gy. Heat was applied by means of a 500 MHz apparatus. Temperature data were converted to equivalent minutes at 42.5 degrees (Eq 42.5). Initial complete response rates and local control distribution were compared for subgroups of tumour volume and thermal dose. The data indicated that the volume effect was less pronounced in the combined modality than in the radiation alone arm, suggesting that the addition of heat was more damaging to the large than to the small lesions. A striking thermal dose-response relationship was shown, although complete response rates increased only after a certain thermal dose was accumulated, clearly indicating the presence of a threshold dose.

Carcinoma, Squamous Cell↗