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Biomedical subjects

G Orsini

Publications and source records attributed to G Orsini.

At least 73 records · Page 4Linked to original sources

Fractures of the limbs complicated by ischaemia due to lesions of the major vessels.

The authors present their case material of 68 patients who had substained fractures of the limbs complicated by arterial lesions. Orthopaedic and vascular surgery should be performed within the shortest possible period of time, preferably within 12 hours of injury, and in certain severe arterial injuries within 4 hours. Osteosynthesis was performed in all cases prior to the arterial repair; in the authors' opinion this brief prolongation of the period of ischaemia has no effect on the general outcome of treatment. In the light of the results obtained, they believe that osteosynthesis should be performed with intramedullary nails in preference to plates. They found that the least satisfactory results were obtained in fractures of the lower two thirds of the tibia and fibula with lesions of the tibial arteries which at this level show characteristics typical of terminal arteries.

Adolescent↗

Retrosternal dislocation of the clavicle. Observations on three cases.

The writers report three cases of retrosternal dislocation of the clavicle which exemplify the three fundamental anatomical variants and the consequent different therapeutic approach. A review of the literature indicates that this condition is extremely rare, although it may sometimes be related to severe and even fatal complications.

Adolescent↗

Hypolipidemic activity of some derivatives of 6H-dibenzo[b,d]pyran.

This paper describes the synthesis of 6-carboxy derivatives of 6H-dibenzo[b,d]pyran. These compounds are among the most rigid structures related to clofibrate ever synthesized, which means they have very few possible conformations of relative stability compared with the many for clofibrate. Compound 6H-2-chloro-6-methyl-dibenzo[b,d]pyran-6-carboxylic acid 3g showed very high hypolipidemic activity being 12 times more potent than clofibrate in reducing plasma cholesterol concentration in the hypercholesterolemic rat and 11 times more potent in reducing plasma triglyceride concentration in the normolipemic rat.

Animals↗

Free H-Y antigen induces in vitro testicular differentiation of human XX embryonic indifferent gonads.

In accordance with the anchorage site hypothesis, Daudi beta 2-microglobulin (-) HLA (-) human male Burkitt lymphoma cells are incapable of stably maintaining H-Y antigen on their plasma membrane; instead, they excrete it into the culture medium. The proposed testis-organizing function of Daudi H-Y antigen in solution, previously demonstrated in bovine ovarian embryonic cells, has been tested for the first time in human undifferentiated gonads. Cultured in the presence of Daudi excreted H-Y antigen, gonads obtained from early human embryos of 46, XX chromosomal constitution underwent precocious and complete testicular differentiation.

Cell Differentiation↗

Synthesis of 3-hydroxy-3-cyclohexylbutyric acid derivatives. 1. Cyclic homologues of 3-hydroxy-3-methylglutaric acid.

Z and E isomers of 3-methyl-3-(carboxymethyl)hexahydro-1 (3H)-isobenzofuranones (I), lactones of 3-hydroxy-3-(2-carboxycyclohexyl) butyric acids (II), were prepared and tested on cholesterol biosynthesis in vitro. Compound I of the Z series was prepared through its ethyl ester by hydrogenation, over Rh/Al2O3 catalyst, of the phenyl ring of 3-methyl-3-[(ethoxycarbonyl)methyl]-1(3H)-isobenzofuranone. Compound I of the E series was prepared, through its ethyl ester, by Reformatsky reaction from ethyl (E)-2-acetylcyclohexanecarboxylate. 3-Methyl-3-(carboxymethyl)-5,6,7,8-tetrahydro-1(3H)-isobenzofuranone, 3-methyl-3-ethyl-5,6,7,8-tetrahydro-1(3H)-isobenzofuranone, and 3-methyl-3-(carboxymethyl)-1(3H)-isobenzofuranone were also prepared and tested. The above compounds inhibited acetate incorporation in cholesterol and fatty acids in rat liver slices at 5 X 10(-3) M but lack specific inhibitory activity on HMG-CoA reductase.

Acetates↗

Synthesis of 3-hydroxy-3-cyclohexylbutyric acid derivatives. 2. Cyclic analogues of mevalonic acid.

The sodium salt of (Z)-3-hydroxy-3-(2-hydroxycyclohexyl)butyric acid (I) and its lactone (II) were prepared through the corresponding tert-butyl ester by hydrogenation, over Rh/Al2O3 catalyst, of the phenyl ring of tert-butyl 3-hydroxy-3-(2-hydroxyphenyl)butyrate (III). (Z)-3-Hydroxy-3-(2-methoxycyclohexyl)butyric acid was prepared similarly. (Z)-4-Methyloctahydro-2H-1-benzopyran-2-one was prepared by hydrogenation, over Rh/Al2O3 catalyst, of 4-methylcoumarine, prepared in turn from III by a one-pot procedure comprising hydrolysis, lactonization, and dehydration. The above compounds inhibit acetate incorporation in cholesterol and fatty acids in rat liver slices at 5 X 10(-3) M, but they lack specific inhibitory activity on HMG-CoA reductase.

Animals↗

Alpha-1-antitrypsin MZ phenotype and cryptogenic chronic liver disease in adults.

Intrahepatocytic inclusions of alpha-1-antitrypsin as markers of Z allele were searched by histochemical and immunohistochemical (peroxidase-antiperoxidase) methods in needle biopsy specimens from 80 consecutive cases of cryptogenic cirrhosis and chronic active hepatitis - HBsAg-negative - in adults. All positive cases and 26% of the negative ones were phenotyped in order to determine the frequency of heterozygous (MZ) deficiency. At variance with previous studies, no prevalence of heterozygous (MZ) deficiency could be demonstrated. This result indicates that further investigations are mandatory to establish if heterozygous (MZ) subjects are predisposed to chronic liver disease.

Alleles↗

Psychopharmacological study with K 8409, a 1H-naphtho[2,1-b]pyran 3-dialkylamino substituted derivative.

A 1H-naphtho[2,1-b]pyran derivative (K 8409) has undergone pharmacological investigation for psychotropic activity. The results show potential antidepressant action quantitatively similar to that of imipramine and amitriptyline, but due rather to MAO inhibition than to imipramine-like activity; interestingly enough, anti-MAO activity was particularly selective for the serotonin-converting enzyme, both centrally and peripherally. The outcome of the other tests suggests that the incidence of untoward effects is likely to be limited.

Animals↗

The renaturation of reduced chymotrypsinogen A in guanidine HCl. Refolding versus aggregation.

The refolding and reoxidation of fully reduced and denatured chymotrypsinogen A have been studied in the presence of low concentrations of guanidine HCl or urea. Renaturation yields of 60 to 70% were observed when the reoxidation was facilitated by mixtures of reduced and oxidized glutathione. Refolding occurred within a narrow range of denaturant concentration (1.0 to 1.3 M guanidine HCl and 2 M urea) in which the native protein was shown to be stable, and the reduced protein was shown to regain the correct disulfide pairing. Renatured chymotrypsinogen is indistinguishable from the native zymogen in chromatographic behavior, potential chymotryptic activity, sedimentation coefficient, and spectral properties. The kinetics of renaturation were determined. Some of the protein species obtained at various times of renaturation were characterized as incorrectly oxidized molecules which could be renatured by thiol-catalyzed interchange of disulfide bonds.

Chymotrypsinogen↗