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Biomedical subjects

A Menditto

Publications and source records attributed to A Menditto.

52 records · Page 3Linked to original sources
PubMed1994

The management of information: storage and retrieval of data.

Internationally harmonized and cost-effective control of chemicals marketed worldwide greatly depend both on the generation of and easy access to reliable and comparable experimental information. Stored data are of use only if information can be retrieved quickly in an understandable form. Some models and theories of information retrieval (e.g. fuzzy set theory, probabilistic approach, artificial intelligence) are briefly discussed first, then followed by applications (such as indexing and clustering techniques). Finally the structure of databases is briefly reviewed.

Database Management Systems↗
PubMed1993

Association of serum copper and zinc with serum electrolytes and with selected risk factors for cardiovascular disease in men aged 55-75 years. NFR Study Group.

Serum Cu (S-Cu) and Zn (S-Zn) levels were determined in 1468 out of 1856 male subjects aged 55-75 years living in the Rome area who participated, between 1989 and 1990, in the second examination in an epidemiological (New Risk Factors) survey. Mean S-Cu and S-Zn concentrations were 15.98 mumol/l (mean +/- 2SD: 10.38-21.58 +/- mumol/l) and 13.69 mumol/l (mean +/- 2SD: 8.94-18.44 mumol/l), respectively. S-Cu levels were directly related to serum calcium levels (S-Ca), serum magnesium levels (S-Mg), daily cigarette consumption, total cholesterol and age (years). S-Zn levels were directly related to S-Ca, S-Mg and cholesterol and inversely related to age. A weak inverse linear relationship existed between S-Zn and S-Cu. After adjustment for body mass index (BMI), smoking habit, alcohol consumption and blood biochemistry in a multiple linear regression model, the relationship of S-Cu (direct) and S-Zn (inverse) to age remained statistically significant.

Aged↗
PubMed1993

The quality of analytical determinations of copper and zinc in serum. A collaborative study in a sample of Italian laboratories.

An external quality assurance scheme for Cu and Zn analysis in serum was carried out in Italy between 1989 and 1990. It included: preparation of control materials by the organizing centre; distribution of control samples to the participants according to a random selection; elaboration of results and evaluation of laboratory performance. Inter-laboratory variability was 16.9% and 16.4%, at concentrations of 0.94 and 1.08 mg/l, for Cu and Zn, respectively. Laboratory performance in terms of percentage of results within the limits of acceptability, improved for Cu, but not for Zn analysis.

Blood Chemical Analysis↗
PubMed1992

Association of selected social, environmental and constitutional factors to blood lead levels in men aged 55-75 years.

Blood lead (B-Pb) levels were determined in 1802 out of 1856 non-occupationally exposed men aged 55-75 years living in the Rome area who participated, between 1989 and 1990, in an epidemiological survey for coronary heart disease (New Risk Factors Project). The median B-Pb level was 113 micrograms/l (10th-90th centiles: 74-180 micrograms/l) and only 0.7 per cent (n = 14) of the subjects had B-Pb values higher than 300 micrograms/l. B-Pb levels were significantly and positively associated to alcohol consumption. Moderate and heavy drinkers had median B-Pb level of 143 micrograms/l (10th-90th centiles: 92-233) and 165 micrograms/l (10th-90th centiles: 102-285) respectively, whereas non-drinkers had a median B-Pb level of 96 micrograms/l (10th-90th centiles: 66-143). The influence of smoking habits was less relevant. Subjects who never smoked and subjects smoking more than 20 cigarettes daily had median B-Pb levels of 103 and 133 micrograms/l, respectively. Individuals classified as habitual car-drivers had slightly higher Pb levels than non-drivers. Subjects classified as manual workers had higher B-Pb levels in comparison with non-manual workers and retired subjects. B-Pb levels were directly related to HDL-cholesterol (HDL-C, r = 0.2252) and gamma-glutamyltransferase (gamma-GT, r = 0.2207) serum levels. The alleged alcohol consumption was more related to B-Pb level (r = 0.3848) than to serum level of HDL-C (r = 0.2474) or gamma-GT (r = 0.2469). A significant correlation (r = 0.2409) also existed between B-Pb and blood cadmium levels (B-Cd). Subjects with a low Gaensler ratio, an index of respiratory function, had higher B-Pb levels. In multiple regression analyses alcohol intake was the most important predictor of B-Pb level, explaining more (14.27%) of the total variance than did B-Cd (4.98%), HDL-C (1.89%), driving habits (1.46%), gamma-GT (1.09%), skinfold thickness (0.96%), and Gaensler index (0.38%). The risk ratio of having B-Pb level higher than 180 micrograms/l (90th centile of B-Pb distribution in our subjects) was 5.3 (95% CI: 2.7-10.4) for drinkers versus non-drinkers and 1.9 (95% CI: 1.2-3.1) for current smokers versus subjects who had never smoked. B-Pb was, at least in our subjects, a more specific and sensitive objective index of alcohol consumption than gamma-GT and HDL-C.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1992

Iron-induced ascorbate oxidation in plasma as monitored by ascorbate free radical formation. No spin-trapping evidence for the hydroxyl radical in iron-overloaded plasma.

A study was made of the interaction of plasma ascorbate and ascorbate free radical (AFR) with exogenously added iron. The quantitative determination of AFR has the advantage that transient increases in ascorbate oxidation can be directly monitored by e.p.r. spectroscopy. An AFR signal was found in the plasma of all donors and was unaffected by superoxide dismutase, catalase and the strong iron chelator deferoxamine. These findings and the rapid decrease in AFR under a nitrogen atmosphere suggest that plasma AFR is probably a result of air auto-oxidation. Iron loading of plasma did not affect the intensity of the AFR signal until the iron concentration approached or exceeded the plasma latent iron-binding capacity. In iron-overloaded plasma, the intensity of the AFR signal increased to about 10 times the normal level before decreasing rapidly to undetectable levels after 15-20 min. Determination of plasma ascorbate showed that the disappearance of AFR was due to a complete loss of the vitamin. When 50 microM-ascorbate was loaded with iron in iso-osmotic phosphate buffer there was an increase in the AFR signal, independent of the iron concentration, which was stable at least for 15 min. Thus the rate of ascorbate loss in the iso-osmotic phosphate buffer was considerably lower than in iron-overloaded plasma. The addition of different iron chelators produced comparable effects on the intensity of the AFR signal in both iron-overloaded plasma and ascorbate solution. These results suggest that the characteristic behaviour of plasma AFR after iron loading is due to its specific iron-binding capacity and to plasma ferroxidase activity. The ferroxidase activity of plasma is important to promote the transfer of Fe2+ into transferrin without a transient ascorbate oxidation. Spin-trapping studies with 5,5-dimethyl-1-pyrroline N-oxide and N-t-butyl-alpha-phenylnitrone revealed that iron-overloaded plasma was unable to produce spin-trap adducts even in the presence of 50-300 microM-hydrogen peroxide or 100 microM-azide. Evidence of OH. radical formation was obtained only after the addition of EDTA. Therefore, iron-overloaded plasma itself does not produce a Fenton reaction and, if ascorbate does indeed have a free-radical-mediated pro-oxidant role, it is not detectable in plasma by spin-trapping experiments.

Ascorbic Acid↗
PubMed1992

[Prevalence of some cardiovascular risk factors in a sample of the aged population].

The distribution of some cardiovascular risk factors in a cohort of elderly population is reported. The study population consisted of 427 males aged 71-91, examined in 1991 and belonging to the Italian rural section of the Seven Countries Study on Cardiovascular Diseases. Systolic blood pressure shows an increasing trend with age, with mean levels greater than 160 mmHg in each quinquennium, while the prevalence of hypertension ranges between 60 and 75%. Other risk factors considered such as serum cholesterol, triglycerides, weight, height and smoking habit show decreasing levels with ageing. This trend is clear also for fasting glucose from the age group 76-80.

Age Factors↗
PubMed1989

Calcium uptake in human spermatozoa: characterization and mechanisms.

Basal 45Ca2+ influx was analyzed in human seminal spermatozoa using a method that allows these highly reactive cells to be easily and safely handled. The uptake was a time-dependent process, with its maximum at 400 s. The kinetics of 45Ca2+ transport was saturating as a function of extracellular Ca2+ concentration with a Km of 429 microM and a Vmax of 1.6 nmol 45Ca2+/mg protein/2.5 min. Depolarizing conditions and the calcium channel blocker verapamil did not affect the uptake; based on this, the presence of operating calcium channels in seminal spermatozoa is excluded. The independence of 45Ca2+ uptake on external concentration of both Na+ and Ca2+ suggests that Na+/Ca2+ exchange does not occur in these cells. The anticalmodulin drug trifluoperazine, the mitochondrial inhibitor antimycin A, and the SH reagents N-ethylmaleimide and mersalyl all inhibited the ion transport. A calmodulin-regulated, energy-requiring, proteinaceous Ca2+ transporter seems to be the main operating mechanism of calcium uptake in human seminal gametes.

Antimycin A↗
PubMed1989

Zinc uptake in human seminal spermatozoa: characterization and effects on cell membranes.

Human ejaculated spermatozoa take up zinc in a time- and concentration-dependent manner. The kinetics of 65Zn2+ uptake is suggestive of an at least partly carrier-mediated transport. The lack of effect of the respiratory chain inhibitor antimycin A could mean that mitochondrial ATP is not required as an energy source for the uptake. The failure of nonpermeant SH reagent mersalyl to modify zinc uptake indicates that functional membrane sulfhydryl groups are not involved in the process. A dose-dependent inhibition of 65Zn2+ uptake was induced by the "anticalmodulin" drug trifluoperazine, suggesting that the calcium-binding protein calmodulin could have a role in zinc transport. In in vitro experiments this cation brought about a powerful effect in protecting the spermatozoa from being damaged by hypo-osmosis.

Antimycin A↗
PubMed1987

Identification of calcitonin receptors in human spermatozoa.

Calcitonin (CT) is a powerful hypocalcemic hormone which regulates calcium balance in cells. The presence of CT and CT receptors has been demonstrated in many extrathyroidal tissues, including the male genital tract. CT immunoreactivity has also been found in human seminal fluid, and an inhibitory effect of salmon CT on human sperm motility in vitro was recently reported. In this study the presence of specific binding sites for synthetic salmon CT in intact human spermatozoa was investigated using [125I]salmon CT. Binding experiments demonstrated a CT-sperm interaction involving a receptor-mediated mechanism. The binding was very rapid and minimally reversible, with the maximal site saturation occurring at approximately 2 nM labeled peptide. The dissociation of the CT-receptor complex was only slightly influenced by the addition of unlabeled hormone. Increasing concentrations of unlabeled salmon, eel, and human CT produced a dose-dependent inhibition of [125I]salmon CT binding. These data fulfill the major criteria for demonstration of specific receptors for salmon CT in human spermatozoa. Owing to the key role of calcium ions in regulating sperm motility and the onset of the acrosomal reaction, CT receptors could be important in male gamete physiology.

Binding, Competitive↗
PubMedDate not supplied

[Macrophage-colony stimulating factor and ovarian cancer].

BACKGROUND: In this study the use of macrophage-colony stimulating factor (M-CSF) as tumor marker for ovarian cancer is evaluated. METHODS: Serum samples were obtained from 74 patients, 43 of these were affected by ovarian carcinoma and 31 by benign ovarian tumors. The M-CSF levels were assayed with an ELISA method and compared with those of 148 healthy women. CA 125 levels were also evaluated. RESULTS: In healthy women the M-CSF levels were 770.4 +/- 145.9 U/ml, the upper limit of normal level was considered 1056 U/ml. Serum M-CSF levels were significantly high in patients with ovarian cancer (1425.3 +/- 1007.1 U/ml; p < 0.001) and in 29 of the 43 patients exceeded the limit of 1056 U/ml. No differences were observed among the histologic types. There were no significant differences between patients with benign ovarian pathology and healthy women. No definite relationship was found with CA 125, but evaluating at the same time M-CSF and CA 125 positive results were found in 95.3% of cases. CONCLUSIONS: Therefore M-CSF can be considered a marker for ovarian cancer, and the assay of its serum levels can be particularly useful in association with those of CA 125.

Adenocarcinoma↗
PubMedDate not supplied

[Obstetric conduct in IUGR].

Purpose of the study is to identify the correct attitude that the obstetrician must engage in the management of pregnancy and birth in case of IUGR. Different methods of diagnosis and therapy of IUGR and the formalities of assistance to the birth have been examined and compared. Accurate clinical examinations of the mother, the study of fetal kariotype and ultrasonography, are essential for the diagnosis of IUGR. The genetic study could be performed by collecting chorionic villi, amniocentesis, cordocentesis or placenta biopsy. Ultrasonography identifies the cases of IUGR, and distinguishes early IUGR from late IUGR. Color Doppler identifies the pathology of the flow in the umbilical artery, in the abdominal aorta and in the middle cerebral artery. After the 26th week, the follow-up of the fetus with IUGR is done with cardiotocography with or without acoustic stimulation or oxytocin. The amelioration of maternal conditions is obtained by avoiding the cigarette smoking, preferring to rest in bed and a balanced feeding; the hyperoxygenation doesn't find unanimous consent. The treatment off IUGR can consist of abdominal decompression, intra-abdominal infusion of amniotic liquid, or use of aspirin. The birth is carried out in the hospital, when the fetus has reached a sufficient maturity. The management of IUGR requires an accurate follow-up and an adequate antepartum therapy. The goal is a birth with less risk.

Counseling↗
PubMedDate not supplied

[Estimate of uncertainty of measurements in clinical laboratories and in environmental, occupational, and preventive medicine].

According to recently issued (UNI CEI EN ISO/IEC 17025, UNI CEI ENV 13005 and prEN ISO 15189) standards, to assure the quality of analytical results and their comparability in time and in different places, testing and clinical laboratories must demonstrate to use validated methods, guarantee the traceability of their measurements and state the measurement uncertainty associated with each result. For some SI quantities, such as the mass, the traceability to SI and the estimate of measurement uncertainty are warranted by established methods. In the clinical laboratory and especially in preventive, environmental and occupational laboratory medicine, specific difficulties arise to warrant the traceability to the mole. On one hand, the whole concept of measurement uncertainty is new in laboratory medicine, on the other hand, its application faces practical difficulties, because of the wideness and the complexity of the analytical repertory, the lack of officially validated methods and matrix-specific reference materials traceable to SI. In this paper we discuss briefly the concept of measurement uncertainty and its meaning in comparison with other parameters used to define the performance of analytical methods. In addition, we describe the procedures recommended by international organisations for estimating measurement uncertainty and interpreting analytical results with an associated measurement uncertainty in comparison with limit values.

Clinical Laboratory Techniques↗