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Biomedical subjects

A Martelli

Publications and source records attributed to A Martelli.

At least 145 records · Page 8Linked to original sources
PubMed1982

Early effects of chemical carcinogens as compared to induced cell proliferation. I. Flow microfluorimetry.

Acridine orange-stained rat liver cells have been analyzed by flow microfluorimetry either after i.p. injection of 0.6 and 5.4 mg/kg of dimethylnitrosamine or 18 hr after partial hepatectomy. Treatment with dimethylnitrosamine induced a marked increase in the fraction of cells with higher green fluorescence intensity which can be related to a greater number of chromatin primary binding sites, and a decrease in the fraction of cells with higher red fluorescence intensity corresponding to a lower amount of cellular RNA. Contrary to the carcinogen-induced early changes towards a more relaxed uncoiled structure, as well as an apparent uncoupling between chromatin-DNA structural alterations and total RNA synthesis, could be first events in the carcinogenetic process.

Acridine Orange↗
PubMed1981

[Effect of treatment with Triton X-100 on DNA integrity and DNA:RNA: protein ratio of rat liver nuclei].

A procedure is described that gives clean nuclei with intact DNA from a rat liver cell suspension. Cytoplasmic contamination is removed by successive treatments with a non ionic detergent, Triton X-100 (0.75%, v/v). We found that with ratios DNA:RNA: protein of 1:0.09:3.29 (2 Triton X-100 steps) the integrity of DNA is preserved: further decrease in RNA and protein content (3 Triton X-100 steps) causes DNA breakage, probably because of extraction of nuclear proteins. In order to estimate DNA integrity, its viscosity was determined by the use of a new oscillating crucible viscometer; this method makes possible the evaluation of extremely small levels of DNA damage as that induced by 0.067 mg/kg of DMNA injected i.p.

Animals↗
PubMed1981

[Staining with naphthol yellow S. 1. Evaluation of the Keq of the protein-dye binding reaction].

A histochemical technique, using acid dye NY-S, for quantitative determination of proteins was tested using cultured cells fixed in a fixative mixture of methanol, acetic acid, formalin (85:5:10, v/v) and stained with increasing ratios of [Dye-]/[R-HN+3] for times up to 30 min. We attempted to evaluate the Keq of the binding reaction of NY-S to proteins. Using a Microphotometer Leitz M PV 2; we have not found the saturation level. We think that this is due either to the presence of secondary binding sites between dye and proteins and stacking phenomena of the dye, or to factors affecting measurements.

Animals↗
PubMed1981

[Staining with naphthol yellow S. 2. Study of the reversibility of the protein-dye binding reaction].

In the present work we studied the reversibility of the binding reaction of Naphthol Yellow S to proteins using a Testing Automatic System Leitz. We presently think that the NY-S staining procedure, can be used as a reliable quantitative method for the determination of nuclear and cytoplasmic proteins only under standardized conditions: the ratio R = [Dye-] / [R-NH+3] must be more greater than 10; for staining periods shorter than 45 min, the slides, at equilibrium, must be mounted in dyeing solution; for quantitative determinations using irreversible bound dye, the staining period must be significantly longer than 45 min (see above) and differentiated in running water for several hours.

Animals↗
PubMed1981

[Viscosimetric evaluation of DNA fragmentation induced in vivo by alkylating agents].

A sensitive viscosimetric approach for measuring DNA single-strand breaks induced by low doses of alkylating agents is presented. The assay is based on the breaks-induced increasing rate of strand separation of rat liver DNA in alkaline solution (pH 12,5; 22 C). Because of the strong dependence of viscosity on DNA unwinding, measurement of time-course of viscosity increase can be used to detect small breakage of DNA. The kinetics of DNA denaturation has been also studied under two different alkaline conditions.

Alkylating Agents↗
PubMed1981

Acetohydroxamic acid therapy in infected renal stones.

The use of acetohydroxamic acid at different dosages is recommended in the treatment of renal lithiasis secondary to urease-producing bacteria. The effects of this drug are directed to urinary ammonium and urinary pH reduction and to potentiation of antibiotic therapy.

Adolescent↗
PubMed1981

Urease inhibitor therapy in infected renal stones.

The strict dependence of struvite and carbonate apatite renal stones on the urease-producing germs confirm the need to combine bacterial urease inhibitor drugs with antibiotic treatment. Of the two antiurease drugs used the better results were obtained with acetohydroxamic acid, both for its minimum side effects and its more powerful urease-inhibitor capacity. Thus stone recurrence was avoided even in patients with urinary infection not responding to specific antibiotic treatment.

Adolescent↗
PubMed1980

Aneurysms of the vein of Galen in children: CT and angiographic correlations.

An aneurysm of the vein of Galen is a rare midline arteriovenous malformation. The clinical signs and the prognosis strictly depend on age of presentation and on the amount of blood shunted into the malformation. In the newborn, cardiac failure is the most common presenting sign. In order children hydrocephalus, headache, focal neurological signs and subarachnoid bleeding may be the reason for admission. At the Hospital for Sick Children six patients with an aneurysm of the vein of Galen were studied by angiography and CT. Four of them were newborn in cardiac failure. Angiography was essential for the accurate demonstration of all the feeding vessels to the malformation and their exact location. Computed tomography also added useful information on associated hydrocephalus and ischemic brain damage. The dilated vein of Galen, straight sinus and torcular were clearly seen. Abnormal arterial vessels feeding the malformation were also recognized.

Arteriovenous Malformations↗
PubMed1979

Pelvic lipomatosis: a nonsurgical diagnosis.

Pelvic lipomatosis is rare in Europe. Preoperative diagnosis is seldom reached and subsequent explorative procedures are necessary. Typical roentgenographic findings are presented. The possibility of an early presurgical diagnosis is emphasized.

Adult↗