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P Oreste

Publications and source records attributed to P Oreste.

29 records · Page 2Linked to original sources
PubMed1991

An ultrastructural and biochemical analysis of the epithelial-mesenchymal interface of the ruminal mucosa during development.

The ultrastructure of fetal and adult bovine epithelial-mesenchymal interface of the ruminal mucosa was described and then correlated to the biochemical analysis for glycosaminoglycans (GAGs). During development a progressive undulation of the basement membrane, increase of connective tissue filamentous material, and folding of the cellular membrane of the basal epithelial cells were observed. Coincidently, a decrease in the relative composition of hyaluronic acid and an increase in chondroitin sulfate was observed. These results suggest a correlation between glycosaminoglycans composition and the expression of some cellular events resulting in morphological changes which operate during ruminal morphogenesis.

Animals↗
PubMed1986

Intimal plus medial thickness of the arterial wall: a direct measurement with ultrasound imaging.

A study in vitro of specimens of human aortic and common carotid arteries was carried out to determine the feasibility of direct measurement (i.e., not from residual lumen) of arterial wall thickness with B mode real-time imaging. Measurements in vivo by the same technique were also obtained from common carotid arteries of 10 young normal male subjects. Aortic samples were classified as class A (relatively normal) or class B (with one or more atherosclerotic plaques). In all class A and 85% of class B arterial samples a characteristic B mode image composed of two parallel echogenic lines separated by a hypoechoic space was found. The distance between the two lines (B mode image of intimal + medial thickness) was measured and correlated with the thickness of different combinations of tunicae evaluated by gross and microscopic examination. On the basis of these findings and the results of dissection experiments on the intima and adventitia we concluded that results of B mode imaging of intimal + medial thickness did not differ significantly from the intimal + medial thickness measured on pathologic examination. With respect to the accuracy of measurements obtained by B mode imaging as compared with pathologic findings, we found an error of less than 20% for measurements in 77% of normal and pathologic aortic walls. In addition, no significant difference was found between B mode-determined intimal + medial thickness in the common carotid arteries evaluated in vitro and that determined by this method in vivo in young subjects, indicating that B mode imaging represents a useful approach for the measurement of intimal + medial thickness of human arteries in vivo.

Adult↗
PubMed1986

Retention of antilipemic activity by periodate-oxidized non-anticoagulant heparins.

Heparin preparations with different anticoagulant and antilipemic (fat-clearing) activities were oxidized with periodate under conditions of cleavage of all the C(2)-C(3) bonds of non-sulfated uronic acid residues, while preserving the original molecular weight of the polysaccharide. Periodate-oxidised heparins (oxyheparins, O-HEP) and the corresponding borohydride-reduced products (reduced oxyheparins, RO-HEP) were compared with the original heparins for their content in trisulfated disaccharide sequences (as determined by 13C-nuclear magnetic resonance) and in active sites for antithrombin-III (as determined indirectly by affinity chromatography), and for their anticoagulant and antilipemic (lipoprotein lipase-releasing) activities. The drop of anticoagulant activity induced by periodate oxidation was paralleled by a substantial decrease of affinity for antithrombin, and is thought to arise from glycol splitting at the level of the D-glucuronic acid residue that is part of the active site for antithrombin. The trisulfated disaccharide sequences and the associated antilipemic activities were substantially unaffected by periodate oxidation. The residual anticoagulant activity of periodate-oxidized heparins obtained from preparations - such as those from beef lung - rich in trisulfated disaccharide sequences is discussed in terms of the influence of charge density on heparin-protease interactions not mediated by antithrombin.

Animals↗
PubMed1983

Correlation between structure, fat-clearing and anticoagulant properties of heparins and heparan sulphates.

Heparins and heparan sulphates from different organs, of high purity by accepted criteria, were characterized by chemical and physical (including electrophoretic and 13C-NMR spectroscopic) methods. The fat-clearing activity of these preparations was shown to be correlated with their content of the trisulphated disaccharide units I2S-ANS,6S (L-iduronic acid 2-O-sulphate-N-sulphated D-glucosamino 6-O sulphate). Species with low anti-lipemic activity contained significant proportions (greater than or equal to 30%) of nonsulphated uronic acids (especially D-glucuronic acid), and of D-glucosamino residues undersulphated at C-6, these latter residues being partially N-acetylated. Heparins from beef lung and sheep mucosa, predominantly consisting of trisulphated disaccharide units, displayed consistently higher antilipemic activity than the more heterogeneous pig mucosal heparins. The anticoagulant activity (as determined by the U.S.P., APTT and anti-Xa tests) was not a simple function of the measured physicochemical parameters. Trends were confirmed for pig mucosal heparins being more anticoagulant than beef lung preparations, and low molecular weight (usually undersulphated) species being more active in the anti-Xa test than in the U.S.P. and APTT tests.

Amino Acids↗
PubMed1981

The structure of heparin oligosaccharide fragments with high anti-(factor Xa) activity containing the minimal antithrombin III-binding sequence. Chemical and 13C nuclear-magnetic-resonance studies.

The chemical composition and the 13C n.m.r. spectra of heparin oligosaccharides (essentially octasaccharides), having high affinity for antithrombin III and high anti-(Factor Xa) activity, prepared by three independent approaches (extraction, partial deaminative cleavage with HNO2 and partial depolymerization with bacterial heparinase), leading to different terminal residues, have been studied and compared with those of the corresponding inactive species. Combined wit chemical data, the spectra of the active oligosaccharides and of their fragmentation products afforded information on composition and sequence. The three types of active oligosaccharides were shown to have the common hexasaccharide core I-Aa-G-As*-Is-As, where I and alpha-L-idopyranosyl-uronic acid, Aa = 2-acetamido-2-deoxy-alpha-D-glucopyranose, G = beta-D-glucopyranosyl-uronic acid, Is = alpha-L-idopyranosyluronic acid 2-O-sulphate, As = 2-deoxy-2-sulphamino-alpha-D-glucopyranose 6-O-sulphate. The fourth residue (As*) is an unusually substituted amino sugar resistant to mild deamination. The 13C spectra of the active species are characterized by signals from the above atypical amino sugar, the most evident of which is at 57.7 p.p.m. These signals, compared with those of appropriate synthetic model compounds, are compatible with the recently proposed 3-O-sulphation of the residue As* [Lindahl, Bäckström, Thunberg & Leder (1980) Proc. Natl. Acad. Sci. U.S.A. 77, 6551-6555].

Animals↗
PubMed1980

Glycosaminoglycans from pig duodenum.

A polysaccharide extract from pig duodenum, used in therapy as antilipemic, was shown by chromatographic and electrophoretic methods to be a mixture of the glycosaminoglycans (GAG) heparin (HEP), heparan sulfate (HS), dermatan sulfate (DeS), chondroitin sulfates (ChS) and hyaluronic acid (HA), in the ratio 24:31:23:9:13. The GAG mixture was fractionated with alkyl-ammonium salts, and, for DeS, with copper salts. Further purification of the fractions either by repeated complexation or by removal of residual impurities using specific enzymes or chemical reactions, permitted obtaining individual GAG more than 97% pure by electrophoretic and 1H-NMR analysis. These preparations will be used to assess the contribution of individual GAG to the biological activity of duodenal GAG extracts.

Animals↗
PubMedDate not supplied

Infections in haematologic neoplasms: autopsy findings.

BACKGROUND AND METHODS: Infections are the main cause of death in most haematologic malignancies. We studied 95 autopsies of patients who died from haematologic neoplasms in the period 1980-1989 at Niguarda Cà Granda Hospital. RESULTS AND CONCLUSIONS: Infections were the cause of death in 63% of patients. In this group of patients bacterial infections accounted for 43% of deaths; fungal infections were frequent too (28%), mainly among leukemic patients; viral (9%), mycobacterial (7%) and polymicrobic infections (11%) were also documented. Haemorrhages were less frequently fatal (12%) due to the availability of haemocomponents. A high number of fatal haemorrhages were associated with fungal infections. Neoplastic progression was the real cause of death in only a few cases, and cardiovascular and pulmonary complications were fatal in the great majority of the other patients.

Agranulocytosis↗
PubMedDate not supplied

Pulmonary and myocardial infarction secondary to arterial occlusion by Aspergillus fumigatus in ANLL.

UNLABELLED: Secondary invasive Aspergillosis is a well-recognized complication of the immunocompromised patient. This case concerned a 52-y.o. male patient affected by ANLL (FAB: M2). On day 10 after induction therapy the patient, previously apyretic and asymptomatic, had an episode of acute dyspnea with fever (39 degrees C). Chest X-ray and pulmonary scintigram were compatible with a diagnosis of pulmonary embolism, and the patient was started on heparin. On day 24 the patient had persistent anginal pain with an ECG compatible with myocardial infarction. The patient was transferred to the coronary unit and died on day 35 after a downhill course. Autopsy findings. Gross examination: multiple infarction involving the whole left lung, the septal and anterior myocardial walls, the left kidney and the spleen. HISTOLOGY: arterial occlusion due only to intravascular hypha growth (Aspergillus fumigatus). This case emphasizes how much astrary the clinical picture can be and how far the fungal dissemination can extend.

Arterial Occlusive Diseases↗