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Biomedical subjects

M Marchetti

Publications and source records attributed to M Marchetti.

At least 91 records · Page 5Linked to original sources
PubMed1996

Endometrial adenocarcinoma and life expectancy in elderly women.

One hundred and six patients with endometrial adenocarcinoma, aged over 70 years, admitted to Gynaecologic Oncological department of Gynecology and Obstetrics Institute of Padua University, from 1/01/1974 to 31/12/1994, were studied. The life expectancy of these women was good, with a personalized abdominal or vaginal surgery, alone with or without lymphadenectomy, or, in advanced stages, associated with integrated therapies. In our case series an increasing frequency of this neoplasia in elderly women appears significant.

Adenocarcinoma↗
PubMed1996

Ki-67 expression in vulvar carcinoma. Preliminary results.

A proliferating cell nuclear antigen (Ki-67) expression was investigated in 73 cases of invasive vulvar cancer, to detect new diagnostic and prognostic factors. We individualized, like Hendriks (1994), two general patterns of reactivity: 1) diffused positivity in all tumoral tissue with a bad prognosis; 2) focal positivity, localized at the edge of tumoral aggregates. Moreover, within focal patterns, one group with positivity to MIB-l of 0.2-6% and another group of 7-9% with different prognoses (better in the first group). Histotype, lymph-nodal status, FIGO stage are strictly correlated with distribution of Ki-67; on the contrary, no correlation was found with grading and number of mitoses.

Adolescent↗
PubMed1996

Neoadjuvant chemotherapy in advanced ovarian cancer.

Eighty-eight patients out of 396 were treated for advanced ovarian cancer first by some cycles of chemotherapy--neoadjuvant chemotherapy-- and after by surgery. An improvement in the quality of surgery and disease-free period was observed while survival rate did not improve, compared with the patients treated by surgery before chemotherapy. It should be stressed that neoadjuvant chemotherapy was applied only in very advanced PS Figo stages. The results are the same in the three studied decades: even in the last one, when cases were selected following new protocols. In our case series all patients after chemotherapy underwent surgery and not only those with partial or complete response to chemotherapy.

Antineoplastic Agents↗
PubMed1996

Predictive value of proliferative cellular nuclear antigen (PCNA) and Ki-67 antigen in advanced stage serous papilliferous ovarian cancer.

The cell nuclear antigens PCNA (Proliferative cell nuclear antigen) and Ki-67 in selected advanced serous papilliferous ovarian cancers were evaluated by histochemical assays. PCNA and Ki-67 expression in primitive tumor cells appeared to be correlated with grading, stage and survival. High expression was found in G3 and in more advanced stages while in low expression survival rate was better.

Adult↗
PubMed1996

[Gallbladder carcinoma today: light and shadow].

On the basis of 30 clinical observations, the authors discuss the clinical and diagnostic features of carcinoma of the gallbladder, which is observed just in an advanced stage in the most part of cases. They also confirm its often poor prognosis. To-day echography and computed tomography play an important role in the preoperative diagnosis.

Aged↗
PubMed1995

Lack of major changes in ATPase activity in mitochondria from liver, heart, and skeletal muscle of rats upon ageing.

ATP hydrolase activity has been investigated in mitochondria from liver, heart, and skeletal muscle from adult (6 months) and aged (24 months) rats. No significant changes in total ATPase activity were observed in the three tissues, but the oligomycin sensitivity was slightly decreased in heart mitochondria of aged rats. The bicarbonate-induced stimulation of hydrolytic activity was somewhat decreased in mitochondria from aged rats, particularly in liver. No significant change was observed in ATPase activity after release of the endogenous inhibitor protein, IF1. It is concluded that no activity changes to be directly ascribed to the catalytic sector F1 of the enzyme occur upon ageing, but it cannot be excluded that changes in the membrane sector F0 occur as a consequence of mtDNA mutations.

Adenosine Triphosphatases↗
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

Correlation of bone mineral density and femoral neck hardness in bovine and human samples.

Bone mineral density (BMD) is a predictor of fracture risk. The purpose of this study was to determine whether a correlation exists between femoral neck BMD and an indicator of mechanical bone strength in human and bovine samples. Human proximal femurs were obtained from seven men and two women undergoing total hip arthroplasty (THA), mean age 60.3 years. Preoperative BMD measurements of the femoral neck were obtained (Lunar DPX). A 3 cm2 area of interest on each excised femoral neck corresponding to the preoperative BMD measurement site was carefully marked and BMD was remeasured postoperatively. Ten excised bovine femoral necks were also measured for BMD. A bicortical core, each cortex 2.8 cm2 in area, containing the center of the area of interest was removed from the human and bovine femoral necks, cut into multiple 7-mm thick, multiple cross-sectional discs, and measured for hardness by indent depth (Rockwell International Hardness Tester, Wilson Mechanical Instruments, New York, NY). In vivo human femoral neck BMD measurements correlated with in vitro BMD measurements (r = 0.99). BMD measurements of human femoral necks were significantly lower than BMD measurements of bovine femoral necks (P < 0.05). Inverse relationships were found between in vivo and in vitro human BMD measurements and indent depth (r = -0.58 and -0.59, respectively). Bovine BMD measurements and indent depth were also inversely related (r = -0.64).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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

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↗