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Biomedical subjects

M Marchetti

Publications and source records attributed to M Marchetti.

At least 109 records · Page 6Linked to original sources
PubMed1995

Radical scavenger activity of bendazac, an anticataract non-steroidal anti-inflammatory agent.

Oxidative damage to lens components is associated with cataract formation and reactive oxygen species (ROS) overproduction at inflammation sites is thought to lead to the development of inflammatory disorders. Bendazac is a non-steroidal anti-inflammatory drug able to delay the cataractogenic process. Aim of the present study is to characterize, both chemically and biologically, the activity of this anticataract agent as a radical scavenger. Bendazac has been shown to be a strong reacting substrate in a chemical oxidizing system, which mimics a physiological pathway of hydroxy radical generation. In the Fenton-Cier reaction the drug rapidly forms a mixture of hydroxylated derivatives, among which 5-hydroxybendazac, bendazac's main metabolite, being a hydroxy radical scavenger itself. Moreover, by means of a rapid and sensitive flow cytometric method able to determine reactive oxygen intermediate production, bendazac and its 5-hydroxy derivative were shown to inhibit oxidative burst activation in polymorphonuclear neutrophil leukocytes (PMNLs).

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↗
PubMed1995

Epithelial ovarian tumors in young women under 35 years.

The aim of this study was to investigate the clinical-pathological pattern of primary malignant epithelial ovarian tumors in women under 35 years old. We have retrospectively analyzed data from 545 patients with these tumors, identifying 49 patients under age 35. We found a higher frequency of borderline tumors and early-stage tumors in young women than in those over 35. The influence of age as a factor in survival was evaluated by comparing the outcome in young patients and in women over 35. The 5-year survival rate, according to stage and aggressiveness factors, was significantly better in young patients. These findings support the concept of a preclinical phase of epithelial carcinoma and show that young women may be selected for conservative surgery, allowing a good quality of life.

Adolescent↗
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↗
PubMed1994

Protective effect of exogenous coenzyme Q against damage by adriamycin in perfused rat liver.

We have investigated the effect of rat liver perfusion with adriamycin on mitochondrial activities. Although the perfusion treatment per se induces some decline of respiratory activities, adriamycin strongly potentiates this effect; moreover the coenzyme Q9 content of the mitochondrial membrane is significantly lowered by the antibiotic. Coaddition of coenzyme Q10 in the perfusate significantly protects the mitochondria, not only from loss of respiratory activities but also of the endogenous CoQ9 content. Exogenous CoQ10 fails to enhance respiratory activities in control rats, not treated with adriamycin, even though CoQ concentration has been proven not to be kinetically saturating in the respiratory chain under physiological conditions. Thus, the beneficial effect of CoQ10 in the perfusate does not appear to be the result of its role in the respiratory chain but is a consequence of its antioxidant action.

Animals↗
PubMed1994

Rotavirus and poliovirus co-infection in HT-29 cells.

The effect of a mixed poliovirus-rotavirus infection in HT-29 cells, a gut tumour derived cell line highly susceptible to both viruses, has been analyzed. The obtained results showed an increase of poliovirus multiplication in cells super-infected or co-infected with rotavirus, whereas the pre-infection with poliovirus had an interfering effect on rotavirus replication.

Antigens, Viral↗
PubMed1994

Ovarian teratomas. An analysis of 134 cases.

All ovarian teratomas observed from 1979 to 1989 in the Institute of Pathology University of Padua are revised. Mature and immature teratomas are analyzed separately because of their different prognoses.

Adolescent↗
PubMed1994

Invasiveness of Shigella flexneri in poliovirus infected HT-29 cells.

In this paper we report the effect in HT-29 cells of mixed infections with poliovirus type 1 and Shigella flexneri serotype 5 strain M90T and derivative strains differing in adhesive as well as invasive properties. HT-29 epithelial intestinal cells derived from a human colon adenocarcinoma are a good model for coinfection studies because they are susceptible both to poliovirus replication and to S. flexneri invasion. The results show that 48 h after infection by poliovirus the invasiveness of wild-type S. flexneri M90T and of its adherent and invasive derivative M90T (pIL22) is increased. However, the alterations produced in HT-29 cells at the later stage of poliovirus infection are not sufficient to promote the internalization of simply non invasive, or non invasive but adherent, isogenic derivative bacterial strains.

Bacterial Adhesion↗
PubMed1994

Cancer procoagulant in the human promyelocytic cell line NB4 and its modulation by all-trans-retinoic acid.

Acute promyelocytic leukemia (APL) cells express different types of procoagulant activity (PCA), including tissue factor (TF), and cancer procoagulant (CP). The aim of this study was to investigate whether the NB4 cell line, the first ever isolated human APL line, with the typical t(15;17) chromosomal balance translocation, possess CP as well as the cells freshly isolated from APL patients. Secondly, since the NB4 line is maturation inducible by all-trans-retinoic acid (ATRA), we wanted to verify whether CP, if present, was affected by ATRA treatment. The NB4 cells were able to shorten the recalcification assay of normal human plasma (total PCA). To distinguish CP in the assay for clotting activity, two criteria were used, the independence from factor VII to trigger blood coagulation and the sensitivity to cysteine proteinase inhibitors. Forty-seven per cent of total PCA of cell extracts was found to be FVII-independent PCA. A similar proportion of FVII-independent activity (42%) was detected in the cell serum-free supernatants. The activity was significantly decreased by cysteine proteinase inhibitors, including HgCl2, lodoacetic acid and Z-Ala-AlaCHN2. Additionally CP was directly identified and quantified by an immunocapture enzyme assay. The mean +/- SD concentration of CP detected by this assay in the NB4 cells, before any treatment, was 1.89 +/- 0.5 microgram/mg protein. Treatment of NB4 cells with 10(-6) M ATRA for 5 days significantly decreased the expression of CP, which became virtually undetectable by the clotting assay, and was 64% less than the untreated control by the immunocapture enzyme assay. This study provides the first evidence that the human promyelocytic cell line NB4 possess CP. The expression of this procoagulant is modulated by ATRA.

Blood Coagulation Factors↗