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Biomedical subjects

M Marchetti

Publications and source records attributed to M Marchetti.

At least 19 recordsLinked to original sources
PubMed1995

Major changes in complex I activity in mitochondria from aged rats may not be detected by direct assay of NADH:coenzyme Q reductase.

We have investigated the respiratory activities and the concentrations of respiratory chain components of mitochondria isolated from the livers and hearts of two groups of rats aged 6 and 24 months respectively. In comparison with the adult controls (6 months), in aged rats there was a decline in total aerobic NADH oxidation in both tissues; only minor (non-significant) changes, however, were found in NADH:coenzyme Q reductase and cytochrome oxidase activities, and there was no change in ubiquinol-cytochrome c reductase activity. The coenzyme Q levels were slightly decreased in mitochondria from both organs of aged rats. The lowered NADH oxidase activity is not due to the slight decrease observed in the coenzyme Q levels, but is the result of decreased Complex I activity. Since the assay of NADH:coenzyme Q reductase requires quinone analogues, none of which can evoke its maximal turnover [Estornell, Fato, Pallotti and Lenaz (1993) FEBS Lett. 332, 127-131], its activity has been calculated indirectly by taking advantage of the relationship that exists between NADH oxidation and ubiquinol oxidation through the coenzyme Q pool. The results, expressed in this way, show a drastic loss of activity of Complex I in both the heart and the liver of aged animals in comparison with adult controls.

Aging↗
PubMed1995

Development of a mouse model of Helicobacter pylori infection that mimics human disease.

The human pathogen Helicobacter pylori is associated with gastritis, peptic ulcer disease, and gastric cancer. The pathogenesis of H. pylori infection in vivo was studied by adapting fresh clinical isolates of bacteria to colonize the stomachs of mice. A gastric pathology resembling human disease was observed in infections with cytotoxin-producing strains but not with noncytotoxic strains. Oral immunization with purified H. pylori antigens protected mice from bacterial infection. This mouse model will allow the development of therapeutic agents and vaccines against H. pylori infection in humans.

Animals↗
PubMed1995

Urinary gonadotropin peptide: collection of specimens and cutoff levels.

A low-molecular-weight form of human chorionic gonadotropin (hCG), urinary gonadotropin peptide (UGP), has been isolated from the urine of pregnant women and of patients with cancer, mainly of gynecological origin. The clinical value of UGP measurement in gynecological diseases is under investigation but a preliminary study is necessary in order to ascertain whether there is a circadian rhythm in UGP production, to clarify the best way to express the results, and to establish the cutoff and decisional values. In our work we demonstrated a significant correlation between the UGP output and the UGP excretion normalized for urinary creatinine. A very significant agreement was even found in 24-hr urine collections and UGP concentration of a single morning specimen from the same patients. No evident circadian rhythm was found, although some patients presented morning levels of UGP higher than in other collections. UGP postmenopausal levels were higher than premenopausal. The cutoff level, adopting the 95.0 percentile, was 200 pmol/mol creatinine.

Adolescent↗
PubMed1995

Cytokines in the viviparous reproduction of squamate reptiles: interleukin-1 alpha (IL-1 alpha) and IL-1 beta in placental structures of a skink.

Placental viviparity is known in many species of squamate reptiles. Among these, some scincids have developed an epithelio-chorial chorio-allantoic placenta which in the structure of its central ridged zone is similar to those of certain therian mammalian species. A broad range of immunoregulatory peptides, cytokines, has been identified at the maternofetal interface of several species of mammals, either with invasive or non-invasive types of placenta. Thus we began to study whether interleukin-1, which is considered to play a crucial role in mammalian pregnancy, might also be involved in the viviparity of reptilian species. Placentae of Chalcides chalcides L. were processed by immunohistochemistry and incubated in a culture medium for different times. A very strong immunoreactivity for interleukin-1 alpha (IL-1 alpha) and for interleukin-1 beta (IL-1 beta) was present in the chorial epiblast and in uterine epithelial cells, with varying degree and localization in different periods of pregnancy. IL-1 beta was also released into the medium at different amounts during incubation. In light of the mammalian data, our results suggest that the role of cytokines in pregnancy may represent a significant event in the evolution of placental viviparity.

Animals↗
PubMed1995

Enhancement of rotavirus infectivity by saturated fatty acids.

The effect of different saturated fatty acids from 10 to 16 carbon atom chains and some derivatives on the infectivity of SA-11 rotavirus was examined. Both fatty acids and derivatives induced an increase of rotavirus infected LLC-MK2 cells when present during viral absorption to host cells. Capric acid and palmitic acid were the most effective with a dose-dependent relationship. These last lipids, in the same experimental conditions, failed to restore the susceptibility to infection of LLC-MK2 cells made resistant by neuraminidase treatment or to allow cell infection by non-infectious single-shelled viral particles. Results obtained suggest that the enhancing effect on viral infectivity by saturated fatty acids requires previous binding of rotaviral outer capsid proteins to sialic acid containing cell receptors.

Animals↗
PubMed1995

The efficiency of walking of paraplegic patients using a reciprocating gait orthosis.

A number of orthoses have been designed to restore stance and walking in paraplegic subjects. Among them, the reciprocating gait orthosis (RGO) appears to be one which is most widely adopted. The great energetic cost of orthotically aided walking is the main factor limiting the walking capability of paraplegic subjects. The purpose of the present research was to give a complete biomechanical evaluation of RGO locomotion in order to provide data that can be used for further improvements of the orthosis. From the whole body kinematics the mechanical work done to move the orthosis was estimated; by measuring the actual metabolic cost of RGO locomotion the efficiency was evaluated as the ratio between mechanical work and energy expenditure. It is found that RGO locomotion is a very demanding task in terms both of energy expenditure and of the mechanical work required. Furthermore, it is evident that the major determinant of this poor efficiency of RGO locomotion is the enormous amount of work required to move the orthosis which, in turn, reflects its poor mechanical characteristics. To accomplish the demand of real mobility, devices for transferring work from the upper to the lower portion of the body must be substantially improved. This technical aspect must be parelleled by suitable training programmes especially designed to improve the aerobic power of paraplegic subjects and their body composition (ie less fat and more muscle).

Adult↗
PubMed1995

The drinking action of Parkinson's disease subjects.

Using the ELITE system, a kinematic analysis was performed of the upper limb drinking action of nine Parkinson's disease patients and nine control subjects. The aim was to use a natural task to investigate the reported Parkinson's disease dysfunction in the performance of simultaneous and sequential movements. Subjects were required to reach 28 cm, grasp a half-filled glass and then take a sip of water. Dysfunction for simultaneous movements was supported by the finding that, in both absolute and relative terms, Parkinson's disease subjects often began to open the hand later than control subjects. Dysfunction for sequential movements was supported by the finding that Parkinson's disease subjects often showed a pause between the first ('reach-grasp') and second ('take-to-lips') parts of the drinking action. Despite these delays and pauses, the proportional organization of the action was similar for both groups. This suggested that Parkinson's disease subjects were able to compensate for the problem in activating the different components of the drinking action. The results are discussed in relation to the influence of the abnormal basal ganglia input to cortical motor regions.

Adult↗
PubMed1995

Role of the Helicobacter pylori virulence factors vacuolating cytotoxin, CagA, and urease in a mouse model of disease.

The pathogenic role of Helicobacter pylori virulence factors has been studied with a mouse model of gastric disease. BALB/c mice were treated orally with different amounts of sonic extracts of cytotoxic H. pylori strains (NCTC 11637, 60190, 84-183, and 87A300 [CagA+/Tox+]). The pathological effects on histological sections of gastric mucosae were assessed and were compared with the effects of treatments with extracts from noncytotoxic strains (G21 and G50 [CagA-/Tox-]) and from strains that express either CagA alone (D931 [CagA+/Tox-]) or the cytotoxin alone (G104 [CagA-/Tox+]). The treatment with extracts from cytotoxic strains induced various epithelial lesions (vacuolation, erosions, and ulcerations), recruitment of inflammatory cells in the lamina propria, and a marked reduction of the mucin layer. Extracts of noncytotoxic strains induced mucin depletion but no other significant pathology. Crude extracts of strain D931, expressing CagA alone, caused only mild infiltration of inflammatory cells, whereas extracts of strain G104, expressing cytotoxin alone, induced extensive epithelial damage but little inflammatory reaction. Loss of the mucin layer was not associated with a cytotoxic phenotype, since this loss was observed in mice treated with crude extracts of all strains. The pathogenic roles of CagA, cytotoxin, and urease were further assessed by using extracts of mutant strains of H. pylori defective in the expression of each of these virulence factors. The results obtained suggest that (i) urease activity does not play a significant role in inducing the observed gastric damage, (ii) cytotoxin has an important role in the induction of gastric epithelial cell lesions but not in eliciting inflammation, and (iii) other components present in strains which carry the cagA gene, but distinct from CagA itself, are involved in eliciting the inflammatory response.

Animals↗
PubMed1995

Inhibition of herpes simplex virus infection by negatively charged and neutral carbohydrate polymers.

Different natural and semisynthetic polysaccharides were evaluated for their inhibitory effect on in vitro replication of herpes simplex virus (HSV) types 1 and 2. Some neutral and negatively charged carbohydrates were able to inhibit viral infection by interfering mainly with the adsorption process showing a dose-dependent relationship. Their effect was shown within the concentration range of 200-0.8 micrograms/ml, and the inhibiting compounds were in order of action: dextran sulfate = scleroglucan = lambda carrageenan > glyloid sulfate 4324 > locust beam gum towards HSV-1 and dextran sulfate = glyloid sulfate 4324 = lambda carrageenan > scleroglucan > glycogen sulfate 4435 towards HSV-2. The data obtained indicate that the antiviral activity of polysaccharides was not only related to their electric charge. Other characteristics of the molecules such as the polymeric backbone, the carbohydrate moieties and the degree of polymerization could play a role in influencing their antiviral properties.

Animals↗
PubMed1994

Mitochondrial activities of rat heart during ageing.

Some analytical and functional parameters of rat heart mitochondrial have been investigated at six different periods of ageing from 2 to 26 months. The fatty acid composition of the mitochondrial membranes reveals a percentage increase of polyunsaturated fatty acids (20:4 n-6, 22:6 n-3) up to 12 months, followed by a decrease; however, fluorescence polarization of the membrane probe diphenylhexatriene is not changed, revealing that membrane fluidity is not significantly affected. No major change in ubiquinone-9 and in cytochrome content is apparent, indicating that the relative ratio of the respiratory chain components is unmodified. Nevertheless, significant changes in enzyme specific activities are detected: NADH cytochrome c reductase and cytochrome oxidase activities increase up to 12 months, then decrease at 18-26 months; ubiquinol cytochrome c reductase exhibits a peak at 18 months, followed by a decrease. All these activities follow a similar trend during the whole life span of the rat, even though the 'maximum' is different. No significant changes have been found in ATP synthase. Succinate-cytochrome c reductase steadily increases over the whole life span. The results, showing activity decreases in the respiratory enzymes having subunits encoded by mitochondrial DNA, are compatible with the 'mitochondrial' theory of ageing.

Aging↗
PubMed1994

Uptake and distribution of exogenous CoQ in the mitochondrial fraction of perfused rat liver.

The system of perfusing rat livers has been used to evaluate the uptake and incorporation of liposomal CoQ10 into mitochondria. After 90 minutes of perfusion the cells are strongly enriched in CoQ10 up to levels of the same order of magnitude as CoQ9. Heavy and light mitochondrial crude subcellular fractions, low in CoQ10 in control livers, contain high amounts of the quinone after perfusion; yet the purification of these fractions on a metrizamide gradient reveals that the exogenous quinone is mainly associated with the light mitochondrial subfraction, enriched in lysosomes. An increase of the NAD-dependent glutamate-malate oxidase activity is observed in CoQ10 perfused animals. As the total levels of CoQ9 + CoQ10 in these animals are not significantly modified by the CoQ10 incorporated, the observed higher activity is not ascribable to an integration of exogenous quinone into the ubiquinone pool. An antioxidant effect of extramitochondrial CoQ10 on mitochondrial functions is suggested.

Animals↗
PubMed1994

Risk factors for breast cancer. Case-control study results.

The great importance of knowing the risk factors for breast pathology in order to reveal the risk categories is well known. In many geographical areas breast cancer is the most common female neoplasm. Recent Italian statistics point out that every year 83 women out of 100,000 develop breast cancer and that its incidence is increasing. Every year in Italy 10,000 women die of breast cancer. In our retrospective study 146 women suffering from breast cancer, treated in our Institute from 1970 to 1993, were enrolled. We excluded 4 patients, surgically treated in another Institute and 35 who presented a second or a third gynaecological cancer. We considered age, menarche, parity and menopausal age in all patients in order to evaluate the association of these risk factors with breast cancer development. The average age when neoplasm was first diagnosed was 53.07 years (between 30-84 years), with a 9.4% incidence in patients under 35 years old. In 41.1% of the cases, menarche was present under 12 years and in only 14.1% after 14 years, therefore confirming the reduction of mammary cancer risk in women with late menarche. Twenty one point five per cent of the patients were nulliparous. In our case series no protective factor seemed to be related with 1 or 2 pregnancies (43.9%). The menopausal average age was 50.2, with an average fertile life period of 37.1 years. Our study also considered the location of the primary neoplasia (60.7% in the upper-outer quadrant), the tumor size (3.08 cm average diameter) and the histological type (81.3% ductal form).(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
PubMed1994

Interaction among dietary vitamin B6, proteins and lipids: effects on liver lipids in rats.

Vitamin B6 is involved in protein and lipid metabolism. Yet the effect of pyridoxine deficiency has been studied in relation to separate dietary parameters, we aim to investigate the effect of pyridoxine deficiency associated with a high intake of proteins and/or low EFA content in the diet. Vitamin B6 and PLP contents, fatty acid compositions of lipids and phospholipids were determined in liver of groups of rats fed on diets with different amounts of proteins (20-40%) and EFA (2-35%). The results show a complex interaction among tested nutritional factors with a prevailing influence of dietary proteins on lipid content of liver and of low EFA intake and vitamin B6 on PUFA metabolism. The effects of pyridoxine deficiency on lipid metabolism were dependent on the EFA content of the diet.

Animals↗
PubMed1994

Surgical strategies in vulvar cancer.

The evolution of surgical strategies in vulvar cancer over thirty years of personal experience is considered. The knowledge of aggressiveness and risk factors of every tumor correlated with the patients' age allows today to perform adequate radical surgery even without the large multilations of the past. 5-year survival rate and incidence of relapses are the same while quality of life is highly improved. The Authors stress the new conservative trend in every field of oncological surgery.

Female↗
PubMed1992

Prolonged bleeding time in patients with lupus anticoagulant.

Platelet adhesion to collagen under flow conditions was studied in 18 patients with lupus anticoagulant, seven of which showed a prolonged bleeding time in the presence of a normal platelet count. The effect of patient plasma, IgG and purified anticardiolipin antibodies on platelet adhesion was also examined. We found a significant reduction of platelet adhesion in patients with lupus anticoagulant, which was more evident in patients with prolonged bleeding time. This platelet adhesion defect could be attributed to a plasma factor. In fact, patients' platelets regained normal adhesion when mixed with normal plasma, whereas controls' platelets showed abnormal adhesion in the presence of patient plasma. A causative role of antiphospholipid antibodies was demonstrated in experiments using purified immunoglobulins and anticardiolipin antibodies.

Adult↗
PubMed1992

SA-11 rotavirus binding to human serum lipoproteins.

An investigation of SA-11 rotavirus binding to human serum lipoproteins was carried out. Various subclasses of lipoproteins, purified by ultracentrifugal flotation, and apoproteins were tested for their activity in inhibiting viral infectivity and hemagglutination. All tested lipoprotein subclasses (very low, low and high density, lipoproteins; VLDL, LDL, HDL, HDL1) were shown to interact with SA-11 rotavirus: VLDL and LDL were the most active in preventing rotavirus replication, whereas HDL and HDL1 inhibited viral hemagglutination to a greater extent. Moreover, A1 and A2 apoproteins were effective towards both viral infectivity and hemagglutination. Results obtained are in agreement with a preferential interaction of VP7 or VP4 proteolytic products with low density lipoproteins and of VP8* with high density lipoproteins. Binding of SA-11 to lipoproteins or apoproteins was also quantified by an enzyme-linked immunosorbent assay procedure and lipoproteins-virus interaction was visualized by electron microscopy.

Animals↗