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Biomedical subjects

F Bersani

Publications and source records attributed to F Bersani.

32 records · Page 2Linked to original sources
PubMed1989

Extremely low frequency pulsed electromagnetic fields increase interleukin-2 (IL-2) utilization and IL-2 receptor expression in mitogen-stimulated human lymphocytes from old subjects.

The effects of the exposure of mitogen-stimulated human lymphocytes from aged subjects to low-frequency pulsed electromagnetic fields (PEMFs) were studied by measuring the production of interleukin-2 (IL-2) and the expression of IL-2 receptor. PEMF-exposed cultures that presented increased [3H]thymidine incorporation showed lower amounts of IL-2 in their supernatants, but higher percentages of IL-2 receptor-positive cells and of T-activated lymphocytes. Taken together, these data suggest that PEMFs were able to modulate mitogen-induced lymphocyte proliferation by provoking an increase in utilization of IL-2, most likely acting on the expression of its receptor on the plasma membrane.

Aged↗
PubMed1989

Extremely low frequency pulsed electromagnetic fields increase cell proliferation in lymphocytes from young and aged subjects.

The effect of the in vitro exposure to extremely low frequency pulsed electromagnetic fields (PEMFs) on the proliferation of human lymphocytes from 24 young and 24 old subjects was studied. The exposure to PEMFs during a 3-days culture period or during the first 24 hours was able to increase phytohaemagglutinin-induced lymphocyte proliferation in both groups. Such effect was greater in lymphocytes from old people which showed a markedly reduced proliferative capability and, after PEMF exposure, reached values of 3H-TdR incorporation similar to those of young subjects. The relevance of these data for the understanding and the reversibility of the proliferative defects in cells from aged subjects and for the assessment of risk related to the environmental exposure to PEMFs has to be considered.

Adult↗
PubMed1989

DNA repair after gamma irradiation in lymphocytes exposed to low-frequency pulsed electromagnetic fields.

The effect of exposure to extremely low-frequency pulsed electromagnetic fields (EMFs) on DNA repair capability and on cell survival in human lymphocytes damaged in vitro with gamma rays was studied by two different micromethods. In the first assay, which measures DNA repair synthesis (unscheduled DNA synthesis, UDS), lymphocyte cultures were stimulated with phytohemagglutinin (PHA) for 66 h and then treated with hydroxyurea (which blocks DNA replication), irradiated with 100 Gy of 60Co, pulsed with [3H]thymidine ([3H]TdR), and then exposed to pulsed EMFs for 6 h (the period in which cells repaired DNA damage). In the second assay, which measures cell survival after radiation or chemical damage, lymphocytes were first irradiated with graded doses of gamma rays or treated with diverse antiproliferative agents, and then stimulated with PHA, cultured for 72 h, and pulsed with [3H]TdR for the last 6 h of culture. In this case, immediately after the damage induced by either the radiation or chemicals, cultures were exposed to pulsed EMFs for 72 h, during which cell proliferation took place. Exposure to pulsed EMFs did not affect either UDS or cell survival, suggesting that this type of nonionizing radiation--to which humans may be exposed in the environment, and which is used for both diagnostic and therapeutic purposes--does not affect DNA repair mechanisms.

Adolescent↗
PubMed1988

Freiberg disease complicating unrelated trauma.

Freiberg's infraction is an avascular necrosis of the metatarsal head characterized by the development of disorderliness of chondrogenesis and osteogenesis in previously normal bone. Radiographic findings follow the pathological progression of bony changes. The presented cases document the development of avascular necrosis in a previously normal metatarsal that occurred after trauma or surgery elsewhere in the foot. It is suggested that infraction of the metatarsal head resulted from microfracture caused by abnormal stress.

Child↗
PubMed1981

[Ribosome crystallization in the in vitro differentiation of chick embryo epidermis].

Six day chick embryo thigh skin has been incubated for 2, 3 or 6 days in media containing either chick embryo extract or chick serum, than submitted to hypothermia for 36 hours to induce the formation of ribosome crystals. The results show that it is possible to relate the crystallization with the different degree of differentiation attained in each experimental condition.

Animals↗
PubMed1981

[Ribosomal crystallization in the in vitro differentiation of mesenchymal cells interacting with the epithelium].

Ribosomal crystallization of 6-day chick embryo thigh skin in vitro in two different nutrient media was studied. The embryo thigh skin has been incubated for 3 or 6 days in media containing either chick embryo extract or chick serum, than submitted to hypothermia for 36 hours to induce the formation of ribosome crystals. The crystals are present in almost all type of cells in E medium, while in the cells in CS medium only after 3 days; therefore it is possible to relate the crystallization with the different degree of differentiation attained in mesenchymal cells.

Animals↗
PubMed1979

[Presence of microtubular and filamentous structures in frequent association with ribosomal crystals].

The contact of tubular bodies and cytofilaments with ribosome microcrystals from chick embryos incubated at 5 degrees C, was investigated by negative staining. It is revealed that for a good observation the time of fixation in glutaraldehyde was a critical point. It is suggested that tubular bodies and cytofilaments are engaged in the transport of ribosomes and ribosome tetramers.

Animals↗
PubMed1979

[Obtaining ribosome crystals in homogenates].

Chick embryos are homogenized in order to analyse ribosome crystallization. Ribosome crystallization has been induced by hypothermic treatment in chick embryos homogenate. Tetramers and crystals were produced by gradually inducing the temperature over a span of 10 h to 4 degrees C. It has been observed that the concentration of KCl in the buffer is a critical point. It is suggested that the nuclear fraction is engaged in ribosome crystallization.

Animals↗
PubMedDate not supplied

Age-related increase of mitomycin C-induced micronuclei in lymphocytes from Down's syndrome subjects.

Peripheral blood lymphocytes from 7 patients with Down's syndrome (DS; trisomy 21) and 14 healthy age-matched controls were studied for the induction of micronuclei (MN) by the cytokinesis-block method. The spontaneous incidence of MN in lymphocytes from DS subjects was lower than that of control cultures. When lymphocytes were treated with mitomycin C (MMC) at the beginning of the culture period, an increase in MN formation was found in cells from both DS and control subjects. In DS subjects this increase was much more marked than in control donors. This effect had to be ascribed to cells from older DS subjects (37-55 years old), which showed an MMC-induced MN formation that was markedly and significantly higher than that observed in cells from younger (9-16 years old) DS subjects. These data indicate that age has to be considered a major variable when studies on the genetic instability of DS subjects are performed.

Adolescent↗