PubMed Health⌕ Search

Biomedical subjects

E Grassi

Publications and source records attributed to E Grassi.

At least 37 records · Page 2Linked to original sources

Effect of detergents on in vitro 7 alpha-hydroxycholesterol formation by rat liver microsomes.

Formation of 7 alpha-hydroxycholesterol by rat liver microsomes was quantitated using a gas chromatograph-mass spectrometer (GC/MS) operated in selected ion monitoring (SIM) mode. Microsomes from normal rat livers incubated for different periods were found to yield increased 7 alpha-hydroxycholesterol with time. This was also true when incubations contained Tween-80, but in this instance, the rate of 7 alpha-hydroxycholesterol production was lower and dependent on the concentration of Tween used. Similarly, Triton X-100, Renex-30, Kyro EOB, Cutscum, and Emulgen 911 all lowered the formation of 7 alpha-hydroxycholesterol by rat liver microsomes, whereas Triton WR-1339 stimulated its production. Analysis of data obtained from following the enzyme reaction over an extended period using an integrated Michaelis-Menten equation indicated the enzyme possesses a very significant affinity for the product (Ks greater than Kp). Similar analysis shows that Tween-80 is a noncompetitive inhibitor of the enzyme.

Animals↗

Measurement of cholesterol 7 alpha-hydroxylase activity with selected ion monitoring.

Formation of 7 alpha-hydroxycholesterol by rat liver microsomes was quantitated using a gas chromatograph-mass spectrometer operated in selected ion monitoring mode. This procedure measures the mass of 7 alpha-hydroxycholesterol formed and does not require addition of labeled cholesterol to monitor the reaction, since endogenous microsomal cholesterol serves as substrate for the enzyme cholesterol 7 alpha-hydroxylase. The method requires only the extraction of lipids from microsomal incubations and injection of a small fraction of this extract into the apparatus. Microsomes from normal rat livers incubated for different periods were found to yield increased 7 alpha-hydroxycholesterol with time.

Animals↗

Carrier detection in Duchenne muscular dystropy.

We investigated the number of echinocytes, the serum hemopexin level, and spectrin band II phosphorylation in the blood of normal subjects, patients, and carriers of Duchenne dystrophy. The patients and carriers exhibited quantitatively significant differences with respect to controls.

Erythrocytes, Abnormal↗

Deformed erythrocytes in muscular dystrophies.

Because of previous reports of a possible correlation between echinocytogenesis and muscular dystrophies, we investigated the time-dependent development of echinocytes in the blood of normal subjects, patients, and healthy carries of Duchenne dystrophy. There was a quantitatively significant increase of echinocytes in patients and carriers.

Adolescent↗

[Erythrocyte changes (echino- and stomatocytic) in muscular dystrophy: research on possible applications in diagnosis and eugenics].

The Authors, after a brief review of the factors which influence the echino and stomatocytic erythrocyte's deformations and of the biochemical basis of these alterations, report the comparative study of the echino-stomatocytogenesis in both normal subjects and myodystrophic patients. In order to investigate whether this phenomenon is more developed in pathological condition, the results confirm that between normal subjects and myodystrophic patients or healthy carriers there is a quantitative significant difference which can be utilized for diagnostic and eugenic purposes. To obtain reliable results, the evaluation should be made at regular intervals of time from the blood drawing and after the exclusion of the presence of other disease or echino-stomatocytogenetic factors (drugs, etc.).

Acanthocytes↗