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Biomedical subjects

R Verna

Publications and source records attributed to R Verna.

32 records · Page 2Linked to original sources
PubMed1983

Na+/K+ ATPase and cell growth: effect of epidermal growth factor on the enzymatic activity in chick embryo epidermis during the embryonal development.

1. The behaviour of ATPase activity during embryonic development of chick embryo epidermis has been studied in the absence or presence of a single inoculation of EGF at the fifth day from fertilization (0-day). 2. EGF strongly decreases ATPase activity by affecting Na+/K+ ATPase. This effect occurs only if begun at 0-day. 3. This effect is due to the EGF induced decrease of -SH groups that are active part of Na+/K+ ATPase.

Animals↗
PubMed1983

Na+/K+ ATPase and cell growth--III: Enzymatic activity in cultured and EGF stimulated HeLa cells.

1. The behaviour of Na+/K+ ATPase during the growth of ectodermal tumoral cells (HeLa) has been investigated. 2. Besides spontaneously growing cells, also samples stimulated with EGF have been tested. 3. The content of--SH groups in the homogenates of both the untreated and the EGF stimulated samples has been tested. 4. Results show a decrease of enzymatic activity during the culture of neoplastic cells and an enhancement of this behaviour in the EGF stimulated cells due to the action of the hormone on--SH groups.

Cell Division↗
PubMed1980

Effects of prazosin on the cAMP system in the spontaneously hypertensive rat (SHR) aorta.

3',5'-adenosine monophosphate (cAMP), adenylate cyclase and cAMP-phosphodiesterase (PDE) activity were measured in aorta homogenates from normal and spontaneously hypertensive rats (SHR) during treatment with prazosin, an antihypertensive drug. cAMP levels were lower in SHR than in normal rats. In SHR prazosin treatment induced marked inhibition of PDE activity thus causing an increase in cAMP levels; adenylate cyclase activity remained unaffected. This effect was only present for the first 32 days of drug administration.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1975

Hormone responsiveness of plasma membrane-bound enzymes in normal and regenerating rat liver.

The hormonal responsiveness of plasma membrane-bound enzymes (Na-+-K-+)-ATPase and adenylate cyclase has been investigated in normal and regenerating rat liver. (Na-+-K-+)-ATPase basal activity is not affected by surgery and only slightly affected by partial hepatectomy; its response to epinephrine and cyclic AMP is decreased only 15 h after hepatectomy. Adenylate cyclase activity of plasma membranes from untreated animals is stimulated by parathyroid hormone and thyroxine; partial hepatectomy increased basal activity as well as the stimulation exerted by the aforementioned hormones, when glucagon and epinephrine sensitivity is essentially unaltered.

Adenosine Triphosphatases↗
PubMedDate not supplied

Na+/K+ ATPase and cell growth IV: a metabolic marker of human brain tumors?

The activity of total, Mg++ dependent and Na+/K+ ATPase as well as the content of cAMP and cGMP in homogenates of human brain tumors have been investigated. Results are compared to values obtained from normal cortices. Na+/K+ ATPase and cAMP are decreased with a close relationship with the degree of malignancy, while Mg++ dependent activity is lower than in normal cortex but with no differences between the various tumors, and cGMP is unaffected. We conclude with a discussion on the metabolism of brain tumors and the suggestion of Na+/K+ ATPase activity as a marker of the malignancy of neoplastic growth.

Astrocytoma↗
PubMedDate not supplied

[Invasive thermometry and prognostic thermometry in radiological hyperthermia].

The term radiological hyperthermia is used to describe the exposure of biological tissues to temperatures just above physiological ones, namely between 42 and 45 degrees C. A machine for hyperthermia (SAPIC SV03 produced by Aeritalia, Caselle, Turin) is been experimentally used at the authors' institute. The present study aims to analyse the technical and qualitative aspects of temperature control using invasive and previsional thermometry. The term invasive thermometry is used to describe the insertion of small teflon catheters into the biological body through which thermometric probes are introduced to control deep temperature. Previsional thermometry is the phrase used to describe the computer simulation of hyperthermic treatment, starting from knowledge of the tissue to be heated and the type of applicator used. The simulated treatment and the real temperature measured are then compared in order to optimize the treatment used.

Equipment Design↗