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Biomedical subjects

M Coppo

Publications and source records attributed to M Coppo.

At least 37 records · Page 2Linked to original sources
PubMed1990

Sex related differences in platelet TxA2 generation.

Platelet lipid composition, c arachidonic acid (AA) metabolism by platelets (stimulated with thrombin), serum thromboxane (Tx)B2 production and plasma lipid composition were investigated in 53 healthy females (18-45 years) and 65 males (19-45 years) with similar dietary habits. In males, serum TxB2 production and cholesterol platelet membrane levels were found significantly higher (p less than 0.001 and p less than 0.05) than in females. No differences were observed between the two groups in the AA conversion through cyclo-oxygenase and lipoxygenase pathways or in the platelet phospholipid fatty acid composition. These findings indicate that in males the platelet proaggregatory capacity is greater than in females and the higher platelet TxB2 production does not depend on a larger AA availability or on enzyme activation for its conversion. The increased TxB2 production may be, at least in part, induced by functional differences such as a different membrane cholesterol content inducing, in its turn, an increased microviscosity and/or higher number of platelet receptors for thrombin.

8,11,14-Eicosatrienoic Acid↗
PubMed1990

Prostaglandins in squamous cell carcinoma of the larynx: tumor and peritumor synthesis.

Prostaglandin (PG) E2, 6ketoPGF1 alpha and Thromboxane B2 (TxB2) production by the tumor, peritumor and control tissue were investigated in specimens from patients (n = 11) with squamous cell carcinoma of the larynx, in relation to the extension and infiltration of the neoplasm and to the presence of inflammation, fibrosis and necrosis. In all specimens detectable amounts of 6ketoPGF1+ and TxB2 were found, but the predominant metabolite was PGE2. No differences in the levels of TxB2 and 6ketoPGF1 alpha were observed, but the only patient with lymphnodal involvement showed the lowest levels of 6ketoPGF1 alpha both in tumor and peritumor tissue. Higher amounts (p less than 0.05) of PGE2 were synthesized by peritumor tissues in comparison to control mucosa and tumor tissue independently of the occurrence of reactive infiltration. PGs synthesis did not correlate with inflammation, fibrosis, necrosis or staging of the neoplasm. However the two cases in stage T4 showed PGE2 generation at the highest levels both in neoplastic and perineoplastic tissue. These findings indicate that in squamous cell carcinoma of the larynx an increased production of PGE2 occurs, stemming not only from inflammatory cells but at least in part from neoplastic cells. This suggests that the study of arachidonic acid metabolism may contribute to characterization of the primary cancer and lead to better understanding of the mechanisms of tumor growth and diffusion.

6-Ketoprostaglandin F1 alpha↗
PubMed1989

Red blood cell lipid alterations in type II diabetes mellitus.

Alterations in blood rheological properties have been reported in diabetes mellitus. Changes in lipid composition of red blood cell (RBC) membranes resulting in an impairment of RBC deformability may play a role in the altered blood rheological pattern. The aim of this study was to investigate the lipid composition of RBC membrane in a group of patients affected by type II diabetes (age 21-45 years), selected on the basis of the absence of complications and good metabolic control, and in a group of suitable control subjects. Saturated fatty acid amounts in the different phospholipid fractions were significantly higher in diabetics than in controls (p less than 0.05), whereas polyunsaturated fatty acids were decreased (p less than 0.05). Cholesterol/phospholipid molar ratio was not altered. On the contrary, sphingomyelin/phosphatidylcholine ratio was higher in diabetics than in controls (1.10 +/- 0.08 vs 0.96 +/- 0.10, p less than 0.01) due specially to high levels of sphingomyelin. These alterations could account for the impairement of RBC deformability frequently reported in diabetes mellitus, independently of metabolic control and the presence of severe atherosclerotic lesions.

Adult↗
PubMed1989

[Behavior of alpha 1-acid glycoprotein in the premature infant].

The interest of clinicians has recently turned to the study of acute phase proteins whose determination, especially in the newborn, offers not only diagnostic information, but also information about prognosis. For many years we have been interested in the study of orosomucoid behaviour in newborn term babies and in low weight premature babies. For this purpose 113 patients were tested, divided into different gestational age groups, from which samples were taken immediately after birth, on the following days and before beginning any kind of treatment to show the behaviour of acid glycoprotein until normal average values were reached. Statistical processing of the data showed an average orosomucoid value in newborn term babies in perfect agreement with the literature. There was correlation among gestational age, weight at birth and orosomucoid concentration, which peaked more quickly the greater the gestational age and weight at birth. Thereafter, the concentration decreased until it stabilised at average term newborn values.

Female↗
PubMed1988

Radioimmunoassay of thromboxane B2 in plasma: methodological modifications.

Thromboxane B2 (TxB2) determination is usually performed by using commercial 3H-RIA kits. However, the low amounts of TxB2 present in plasma are not detectable without previous extraction. The aim of this study is the evaluation of 1) plasma protein interferences on the binding and separation steps of bound from free analyte and 2) charcoal efficacy in different experimental conditions. Our results indicate that plasma proteins do not influence the antibody binding, but significantly reduce the efficacy of precipitation of kit dextran-charcoal, so that the supernate radioactivity rises with the protein amount increase (r = 0.99 p less than 0.001). Such greater number of counts in the samples determines a lower estimation of TxB2 concentration in plasma when the calibration curve is set up in buffer. Our findings suggest that, in order to measure low amounts of plasma TxB2 without extraction, it is useful: 1) to refer to a calibration curve set up in buffer-diluted plasma, 2) to use the uncoated charcoal concentration allowing the lowest stripping and 3) to perform all steps at 4 degrees C.

Charcoal↗
PubMed1988

Altered lipid composition and thromboxane A2 formation in platelets from patients affected by IIa hyperlipoproteinemia.

Platelets from patients with familial hypercholesterolemia (type IIa hyperlipoproteinemia), a condition associated with high prevalence of atherosclerosis and of its thrombotic complications, are known to be hyperresponsive to aggregating stimuli and to synthesize increased amounts of thromboxane A2 (TxA2) in comparison to platelets from normal subjects. In order to search if these functional alterations are linked to a different platelet lipid composition, we studied a group of young patients affected by IIa hyperlipoproteinemia and a group of suitable controls with similar dietary habits. Both cholesterol and phospholipid content of platelets were higher in patients than in controls with a significant increase of cholesterol/phospholipid molar ratio (at least p less than 0.05). The percent contents of the main platelet phospholipid fractions were not altered, while an increase in saturated fatty acids, both unesterified and esterified in different lipid fractions, was observed. Moreover, an increased TxA2 production by platelets and a significantly increased number of megathrombocytes occur in patients with respect to controls (p less than 0.001). Our results indicates that platelets from patients with IIa hyperlipoproteinemia have an altered lipid composition which could explain, at least in part, the enhanced platelet reactivity reported in these patients.

Adult↗
PubMed1987

[Internal medicine evaluation of the surgical risk in cirrhosis patients].

A personal case series triggers an examination of surgical risk in patients with uncomplicated cirrhosis of the liver. After a general introduction the conditions that increase surgical risk in cirrhotic patients are analysed. These include generally poor resistance, altered haemostasis, a tendency towards cholestasis, water retention and hepatic encephalopathy. The conditions most often requiring surgical treatment are then considered. They include associated pathologies (cholelithiasis, hernias, tooth extractions, bleeding haemorrhoids etc) and complications of cirrhosis variceal bleeding, intractable ascites, splenomegaly, hepatocytoma).

Blood Coagulation Disorders↗
PubMed1987

Ultrastructure of a two-cell human embryo.

A two-cell human embryo recovered from the Fallopian tube 82 h following the LH peak in plasma and 37 h after a single episode of intercourse was examined by transmission electron microscopy. At the time of recovery the embryo was denuded of cumulus cells, and both the zona pellucida and the two adjoining blastomeres were intact. The finding of two polar bodies in the perivitelline space, two nucleated blastomeres and remnants of the fertilizing sperm tail within the cytoplasm of one of them, were considered as evidences that the embryo was normally fertilized. Among the most conspicuous features found were the presence of very distinct desmosome-like structures between blastomeres, and the cytoplasmic cell organelles distribution in three areas referred as: a sub-cortical, a middle and a perinuclear bands. An outstanding feature was the extensive blebbing of the nuclear envelope. In general, the features seem to correspond to a normally developing two-cell embryo undergoing cleavage at a normal rate.

Blastomeres↗
PubMed1986

Trans-scapho-capitate perilunar dislocation of the carpus.

Trans-scapho-capitate perilunar dislocation of the carpus is a rare variety of perilunar dislocation. The characteristic feature of this lesion is that the head of the capitate is rotated 180 degrees. The capitate fracture occurs at the neck level and when the body is displaced dorsally with the perilunar dislocation, the unsupported head cannot remain in anatomical relationship with the lunate and thus rotates on itself. The authors report a case that was treated by conservative reduction, the result of which was far from satisfactory. They therefore advise that this lesion should be treated by immediate open reduction with osteosynthesis of the scaphoid.

Adult↗
PubMed1985

An electron microscopic study of sperm penetration into the human egg investments.

The ultrastructure of human spermatozoa located in the cumulus cells and the zona pellucida of a pro-nuclear egg, and in the zona pellucida of a two-cell egg, both fertilized in-vivo, has been analysed in order to understand how the human spermatozoon penetrates the investing coats of the oocyte. Among the 36 spermatozoa found in the cumulus cells, 31 were phagocytosed by cumulus cells and 5 were wedged in the matrix between the cells. These spermatozoa were acrosome-reacted and their equatorial segment was intact. Six of the seven spermatozoa found in the zona pellucida (four spermatozoa in the pronuclear egg and three in the two-cell egg) had lost the equatorial segment, while the other one was partially reacted. The sperm heads were located in slits with sharp edges. From these findings it was concluded that in the human (1) only few and normal spermatozoa seem to reach the cumulus cells after natural insemination, (2) the acrosome reaction probably occurs sometime before the spermatozoa reach the vicinity of the corona cells, (3) the reaction of the equatorial segment seems to occur during or before the initial phase of zona penetration, since the spermatozoa located in the matrix of the zona pellucida had no equatorial segment. No evidence of the presence of spermatozoa with an intact acrosome in the matrix of cumulus cells or with an intact equatorial segment in the zona pellucida were found.

Female↗
PubMed1985

The Estes operation (transposition of one ovary to the uterine cavity): its results in the rabbit model.

Pregnancies have been reported after the Estes procedure (EP). These results have not been duplicated in modern attempts. The recent report of intrauterine fertilization in humans gives support to the feasibility of this procedure as a possible alternative to in vitro fertilization. An animal model is needed to evaluate the outcome of this operation. Consequently, 14 mature New Zealand white rabbits had one ovary placed in the uterine cavity after contralateral oophorectomy and bilateral salpingectomy. One month later, the animals were mated with a fertile buck. Fourteen to 16 days after that, the outcome was evaluated. Twenty-five to 75% of the ovarian surface was exposed to the uterine lumen, and no evidence of ovulation or implantation was found. The lack of pregnancies was attributed to an ovulatory dysfunction. Anovulation after the EP may also occur in the clinical situation, as suggested by one histologic study. The ovulatory function of these patients has not been characterized in the literature. Documentation of a successful intrauterine fertilization with delivery of a term baby supports the theoretical feasibility of the EP; however, anovulation incurred by our procedure appears to be the major drawback.

Animals↗
PubMed1984

Ultrastructure of the cumulus cell mass surrounding a human egg in the pronuclear stage.

The cumulus cell mass enclosing a penetrated human egg was studied. The egg, recovered from the Fallopian tube approximately 80 h after luteinizing hormone peak and 35 h after insemination, was surrounded by a large, expanded and dissociated cumulus. Dispersions of the outermost cumulus cell layers occurred during processing, the innermost cell layers remained attached enclosing the egg. The photomicrographs showed that the follicular cells were embedded in an intercellular matrix and contact via gap-junction-like structures between neighboring cells existed. Cumulus cell processes traversing the zona pellucida were not found. Two types of follicular cells coexisted within the cumulus, light and dark cells. These cellular types, were different in morphology and size. Light cells displayed cytoplasmic organelles normally associated with protein synthesis and steroidogenesis. Dark cells with long cytoplasmic processes were involved in sperm phagocytosis. It is suggested from the characteristics of the cytoplasmic organelles that dark cells seem to be modified light follicular cells.

Female↗
PubMed1984

The functional potential of the rabbit fimbria.

The ability of the normal rabbit fimbria to retrieve eggs after progressive reduction of its mucosal surface was tested on 16 New Zealand white rabbits. Group 1 had a small fimbrial resection; group 2 had a large one. The resected tissue was weighed, and in both groups the contralateral fimbria (internal control) was cut and sutured without resection. Four weeks later the animals were mated, and 12 hours afterwards the ovulation sites on each ovary were counted and both tubes excised. In vivo observations of the transport of cumulus surrogates by the experimental fimbria were made before tubal excision in group 2 animals. The natural eggs retrieved by the fimbria were recovered by flushing the resected tubes with saline. The infundibulum and fimbria were cut from the ampulla and weighed to calculate the amount of fimbrial resection achieved. In group 1 the experimental side retrieved 82% of the eggs; in group 2 the experimental side retrieved 72%. In vivo observations revealed the presence of a spontaneously formed neofimbria that transported cumulus surrogates in a normal pattern and at a normal rate. The fimbria appeared dispensable, a fimbrialike structure formed spontaneously, the functional results were optimal, and the number of ovulation after surgery was unchanged. Some similarities can be observed in women.

Animals↗