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Biomedical subjects

A Becciolini

Publications and source records attributed to A Becciolini.

At least 73 records · Page 4Linked to original sources
PubMed1979

Post-irradiation enzyme activities of the rat small intestine: effects on circadian fluctuations.

The effects of ionizing radiations on circadian fluctuations in the activities of small bowel mucosal enzymes were studied. The fluctuations in activities of brush-border enzymes disappeared after irradiation coincidentally with changes in their activity. This change was particularly pronounced with leucinaminopeptidase. At longer periods after irradiation (50 and 74 hours) when the whole epithelium showed morphological changes, the activity of brush-border enzymes was very low. The activity of lysosomal enzymes (which do not show circadian fluctuations) increased when the epithelium showed marked morphological modifications and the stroma contained numerous inflammatory cells.

Animals↗
PubMed1977

In vivo absorption of carbohydrates in rats with gastro-intestinal radiation syndrome.

Absorption of glucose and sucrose by intestine from supralethally irradiated rats was investigated using an in vivo preparation. An activation of glucose absorption one day day after exposure is followed by a marked fall in glucose and sucrose absorption on day 3. Experiments under different conditions of loading indicate that at 20 hours active transport of glucose is already impaired although the maximum velocity is increased. After 3 days maximum velocity and active transport decrease markedly. Inverstase activity increases after 20 hours, but this is not accompanied by an increased sucrose absorption. The defect in sucrose absorption 72 hours after irradiation is paralleled by a decrease in invertase activity.

Animals↗
PubMed1977

Intestinal enzyme distribution after supralethal irradiation.

The activity of some intestinal enzymes has been studied after 2 kR irradiation. Brush border enzymes, maltase and leucineaminopeptidase (LAP) show an increase 20 hours after irradiation, while after 72 hours their activities are reduced to very low levels. Lysosomal enzymes show a completely different behaviour: acid phosphatase activity increases only 72 hours after irradiation, whereas beta glucuronidase increases significantly after 20 hours and reaches values two or three times higher than controls after 72 hours. The histologic picture at the first interval after irradiation shows gross alterations in the crypt region, but the villi appear nearly normal. Seventy-two hours after irradiation the whole epithelium is affected and very numerous leukocytes are present in the stroma.

Acid Phosphatase↗
PubMed1976

Water (electrolyte) balance after abdominal therapeutic treatment.

Total body water, plasma volume and Na space have been studied in 34 patients receiving external radiotherapy on the pelvic region. Determinations were made on the same patients before, and half-way treatment; in a few cases, some determinations were also repeated after the end of treatment. The results failed to show any appreciable modification of the different parameters studied.

Adult↗
PubMed1975

Behaviour of intestinal lactase after irradiation.

The behaviour of intestinal lactase has been studied in rats after irradiation. The significant increase of activity is not immediate, but slowly and progressively starting from 4 hrs after irradiation. The modifications of the activity are slow and gradual also during the reduction phase. This disaccharase does not show a return to normal values even after three weeks. We suggest that hypothesis that the increase could be due to a modification of the normal synthesis of enzymes caused by irradiation.

Animals↗
PubMedDate not supplied

A method for measuring microquantities of DNA.

Quantitative analysis of DNA content represents a critical step when only very small amounts of nucleic acids are available. The DNA content of a small RNA-free sample can be measured in a simple and precise way using a two-dimensional approach. DNA samples are spotted on the surface of an agarose gel containing ethidium bromide (EtBr) and the ultraviolet-induced low-light fluorescence emitted by EtBr molecules intercalated into the DNA is evaluated. The high sensitivity and reproducibility of this quantitative method has been obtained using an advanced analysis system capable of distinguishing low-light fluorescent patterns, as in the case of DNA stained with EtBr, from the background. Use of an internal standard is necessary because the intensity of the signal is due to the aperture of camera diaphragm and to gel conditions. Using this two-dimensional analysis system it is possible to obtain rapid and precise quantitation of as little as 2 ng of DNA.

Animals↗
PubMedDate not supplied

Labeling index in squamous cell carcinoma of the larynx.

Two cell kinetic parameters, the 3H-thymidine labeling index (TLI) and the mitotic index (MI), were studied in vitro on fragments of squamous cell carcinoma tissue of the larynx. They were evaluated to identify those elements able to characterize the growth of these solid tumors. The values of these parameters were analyzed as a function of the clinical stage and the involvement of the regional lymph nodes. Results showed a statistically significant increase in the TLI from stage T1 to T3. No statistically significant differences in the TLI values were observed between the patients with positive and negative lymph nodes.

Adult↗