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Biomedical subjects

A Viti

Publications and source records attributed to A Viti.

At least 19 recordsLinked to original sources
PubMed1998

[Blood lead levels in a non-professionally-exposed population from six Tuscan provinces].

We report the results obtained in 1992 concerning the determination of blood lead levels (PbB) in 1321 subjects of the general population living in ten villages/towns of the Florence district characterised by the presence of artistic ceramic factories. We reported also the PbB values found in 2330 adults, 280 children, 39 pregnant women and their correspondent umbilical cords, who were examined during the second biological monitoring campaign against the risk of lead intoxication according to the DPR 496/82. Median PbB values were 92.5 micrograms/l (range 15-520 micrograms/l) for males and 62.5 micrograms/l (range 11-343 micrograms/l) for females. The lower PbB median values were found in the district of Livorno (76.25 micrograms/l and 48.25 micrograms/l in males and females, respectively) and Arezzo (80.5 micrograms/l and 52 micrograms/l in males and females, respectively). In comparison with the results obtained for the general Italian population during the previous biological monitoring campaign carried out in 1985-86 we observed PbB median values about 40% lower for both males and females and PbB median values about 55% lower for children. A significant statistic correlation (r = 0.53) was found between PbB of pregnant women and their umbilical cords.

Adolescent↗
PubMed1994

Responses of atrial natriuretic peptide and other fluid regulating hormones to long distance swimming in the sea.

The plasma hormonal response following a swimming competition in the sea (18 km) was evaluated in 12 top level male endurance swimmers. At the end of the effort, while plasma renin activity (PRA) and aldosterone concentration (ALDO) were unchanged, a significant increase in plasma atrial natriuretic peptide (ANP) and antidiuretic hormone (ADH) concentrations were recorded. These changes were associated with a decrease in haematocrit and an increase in Na+ and Cl- plasma concentrations. The individual variations of ANP (difference between the final and initial concentrations) were inversely correlated with the corresponding individual variations of PRA and ADH. The results suggest that, during prolonged swimming, ANP may exert an inhibitory effect on the PRA-ALDO axis and have a modulatory role with regard to ADH secretion.

Adolescent↗
PubMed1993

Intraocular pressure during mechanical ventilation with different levels of positive end-expiratory pressure.

OBJECTIVE: To determine the effect of positive end-expiratory pressure (PEEP) on intraocular pressure. DESIGN: Prospective, controlled, longitudinal, dual center study. In one group, patients served as their own control. In the second group, isolated determinations of intraocular pressure were made in mechanically ventilated patients receiving PEEP. SETTING: Adult intensive care units of two university hospitals. PATIENTS: Intraocular pressures were measured serially in eight patients during the recovery phase of different clinical conditions and in 22 patients receiving mechanical ventilation with PEEP > or = 10 cm H2O for > 24 hrs. INTERVENTIONS: Group A) In eight patients, a PEEP dose-response curve was established (PEEP 0, 5, 10, 15, and 0 cm H2O every 15 mins). Intraocular pressures were measured at the end of each period. Group B) In 22 patients, measurement of intraocular pressures were done while the patients received mechanical ventilation with PEEP > or = 10 cm H2O for at least > 24 hrs. MEASUREMENTS AND MAIN RESULTS: In both groups, there was a positive correlation between the PEEP level and the central venous pressure (p < .05 in group A, and p < .03 in group B). No relationships between intraocular pressure and PEEP or central venous pressure were observed. However, there was a correlation between intraocular pressure and length of PEEP therapy (p < .03). We found ocular hypertension in only one patient (right eye intraocular pressure = 26 mm Hg; left eye intraocular pressure = 24 mm Hg). CONCLUSIONS: Short-term therapy with PEEP of < or = 15 cm H2O does not present a clinically important significant risk for intraocular pressure increase in a population with normal basal ocular tonometry. During prolonged mechanical ventilation with PEEP, increments in intraocular pressure may occur, but these increments appear to not be of a clinically relevant magnitude.

Adult↗
PubMed1993

Atrial natriuretic peptide and acute myocardial infarction: critical reappraisal.

The present investigation was designed to assess the correlation of atrial natriuretic peptide (ANP) with the ordinary markers of acute myocardial infarction (AMI). In 15 patients with uncomplicated AMI, no remarkable variation in ANP plasma levels was found. On the other hand, serum myoglobin and cardiac enzymes behaved as usual. Our results show that ANP is not correlated with serum myoglobin, creatine-phosphokinase and its isoenzyme MB, being completely independent from these markers of myocardial injury. These observations suggest that the plasma ANP variations observed in AMI by other investigators are probably dependent on hemodynamic dysfunction.

Aged↗
PubMed1992

Changes in the exercise-induced hormone response to branched chain amino acid administration.

It was the aim of the present experiment to detect possible effects of branched-chain amino acids (BCAA) on the endocrine response to 1 h of continuous running. Blood samples were collected from 14 long-distance runners (age 24-42 years) in two different trials performed at 1-week intervals. In both trials (E and P) blood samples were collected at the following times: 9 a.m. (basal values sample), 10.30 a.m. (sample 90), 11.30 a.m. (sample 150), 12.30 p.m. (sample 210); the athletes performed 1 h of running at a constant predetermined speed between samples 90 and 150. Following the basal sample a mixture containing BCAA (E trial), or not containing BCAA (P trial) was ingested. In both trials no hormone basal concentrations, except insulin, were changed before exercise. In P trial, following exercise (sample 150), human growth hormone (HGH), prolactin (PRL), adrenocorticotropic hormone (ACTH) and cortisol (C) increased, while testosterone (T) decreased. In sample 210, after 1 h of rest, while ACTH, PRL and HGH had recovered to basal concentrations, C remained elevated and T displayed a further decrease. In the E trial a similar pattern of change was observed in sample 150 for HGH, PRL, ACTH and C; in sample 210 HGH and PRL displayed significantly lower values than in the corresponding P trial samples. The T was not modified by the running exercise and increased during the recovery period. It is, therefore, suggested that BCAA administration before exercise affects the response of some anabolic hormones, mainly HGH and T.

Adrenocorticotropic Hormone↗
PubMed1990

In vivo stimulation of lung collagen synthesis by collagen derived peptides.

In the present work we examined the "in vivo" effects of collagen breakdown products derived from elastase digestion on lung collagen synthesis in rabbits. It was found that i.v. injection of collagen peptides greatly enhances the collagen synthesis rate while does not affect the synthesis of non collagenous proteins. The increase of incorporation of 3H-proline in lung collagen parallels that of prolyl hydroxylase activity. The collagen synthesis, expressed as fractional rate (% day), amounted to 15% day in treated animals, resulting in a significant increase with respect to controls (11.7% day). The observations reported provide evidence that collagen breakdown products stimulate lung collagen synthesis and may play a role in collagen homeostasis.

Animals↗
PubMed1990

Development of interstitial lung fibrosis by long-term treatment with collagen breakdown products in rabbits.

We recently demonstrated that collagen breakdown products derived from elastase digestion (CDP) can stimulate "in vivo" lung collagen synthesis. The present work deals with the morphological and biochemical characteristics of an experimental model of lung fibrosis developed in rabbit by long-term treatment with CDP. Stimulation of collagen synthesis by CDP resulted in a significant thickening of alveolar septa due to accumulation of fibroblasts and a marked deposition of collagen fibrils as revealed by light as well as electron microscopy. Biochemical analysis confirmed the increase in lung collagen deposition. Total collagen content as determined by hydroxy-proline analysis was increased in CDP-treated animals of about 56% in respect to control animals. A relative increase of type I collagen in respect to type III was also observed. An additional interesting observation was a progressive hyperplasia of type II pneumocytes. Unlike other experimental models of lung fibrosis, the collagen deposition in our condition is not preceded or associated with inflammatory or degenerative processes. This fact renders this model very suitable to study matrix-cell interactions in pulmonary fibrogenesis.

Analysis of Variance↗
PubMed1989

Hormonal changes after supine posture, immersion, and swimming.

This study was undertaken to evaluate the effects of the supine posture, immersion, and swimming on hormones involved in the regulation of hydrosaline equilibrium. Plasma levels of atrial natriuretic peptide (ANP), arginine vasopressin (AVP), plasma renin activity (PRA), and aldosterone (ALDO) were measured by radioimmunoassay in eight untrained young subjects (five males and three females). Blood samples were collected on different days: control morning samples in a relaxed standing posture before each test; after 20 min in a supine position; after 20 min of horizontal immersion in water at 28 degrees C; after 20 min of backstroke swimming (speed about 1 m/s). No changes occurred in AVP levels after each test. ALDO and PRA increased significantly only after swimming and were directly correlated. ANP increased significantly after immersion, but no further increase was observed after swimming. The hematocrit, which increased after swimming, was inversely correlated with ANP levels in the post-exercise samples. These data show that while ALDO and PRA increase only in response to swimming, even at moderate intensity, ANP probably requires more prolonged and intense exercise to reach a significantly higher level than in immersion.

Adult↗
PubMed1988

Korsakoff's psychosis due to massive beer intake provoked by diabetes insipidus.

Posttraumatic diabetes insipidus, acute pancreatitis, and Wernicke's encephalopathy and Korsakoff's psychosis in a 33-year-old white male alcohol abuser resulted in near-fatal cardiovascular collapse. The Wernicke's encephalopathy and Korsakoff's psychosis resulted from drinking massive quantities of beer to satisfy the thirst induced by diabetes insipidus. Although the diabetes insipidus was controlled with vasopressin, and the need for vasopressin resolved two months after diagnosis, the Wernicke-Korsakoff syndrome had not resolved by six months.

Acute Disease↗
PubMed1987

DNA synthesis and interferon release by human peripheral lymphocytes exposed to high potassium medium.

Lymphocytes have their membrane potential changed during transition from the resting to the active state. On these grounds, we investigated the response of human peripheral lymphocytes to a depolarizing high-potassium (102.7 mM) medium, by assaying cellular incorporation of labeled thymidine and interferon (IFN) release in the culture medium. The greatest effect is evident 3-4 days after preincubation for 120 min in high K+ medium. A temporal correlation has been observed between rate of DNA synthesis and IFN production. The IFN activity is shown to be gamma-type.

Cells, Cultured↗
PubMed1986

Hormonal and metabolic effects following a football match.

Hormonal and metabolic parameters were studied for two teams after a football match. Blood samples were collected before the start, at half-time, at the end, and 45 and 90 min after the end of the game. In the first team, ACTH, cortisol, and lactate levels increased significantly during the whole match to resume basal levels in the fourth sample (45 min after the end of play). HGH, prolactin, and blood glucose were found to be increased only at half-time. The second team had an intense and long warm-up period before the match and the lactate concentrations were already elevated in the first sample. All the other parameters, except ACTH and glucose, displayed a pattern similar to that of the first team. The differences in the time courses of the hormonal and metabolic values are discussed.

Adrenocorticotropic Hormone↗
PubMed1985

Androgen levels following a football match.

In 18 trained football players, blood samples were collected before a football match, at half-time, at the end, and 45 and 90 min after the end of the match. The testosterone (T) level showed a decrease in the rest period. Dihydrotestosterone (DHT) increased during the match, but returned to initial levels in the last samples. The T/DHT ratio decreased, reached the minimal value at the end of the exercise, and returned to basal levels in the rest period. Cortisol and androstenedione levels increased during the match, but returned to control levels 45 and 90 min after the end of the match, respectively. It is suggested that during this type of exercise anabolic and catabolic hormones may be simultaneously activated.

Adult↗
PubMed1985

Effect of exercise on plasma interferon levels.

The effect of exercise on plasma interferon activity was studied on eight male subjects before and after exercise on a bicycle ergometer for 1 h at 70% of their maximal O2 consumption (VO2 max). Acid-labile interferon, alpha-type according to immunological characterization, rose significantly from a preexercise value of 3 +/- 1 to 7 +/- 2 IU/ml postexercise. Negligible changes were recorded for plasma protein, lipid, and glucose concentrations, whereas blood lactate slightly increased only at the end of exercise. According to hematocrit and plasma protein values before and after exercise, hemoconcentration did not occur. These data provide evidence that plasma interferon activity increased following a bout of submaximal exercise.

Adult↗
PubMed1985

The physiologic interferon response. VI. Interferon activity in human plasma after a meal and drinking.

Interferon activity in plasma was found negligible in the morning and slightly increased in the afternoon. However, because of the wide variability of the results, the difference was not statistically significant even though the existence of a circadian rhythm appears possible. The afternoon increase of IFN activity could be at least in part due to increased abdominal lymphatic drainage following digestion and absorption. In fact, it has been shown that there is a significant transient increase in IFN plasma level 2 hours after a fat-rich meal or drinking 700 ml of water. IFN activity was due to acid-labile IFN-alpha. This is another, yet indirect, indication of the existence of the physiologic IFN response that entails a localized production of lymphomonokines with limited spillover in the circulation.

Adult↗
PubMed1979

Early increase of cyclic adenosine monophosphate level induced by erythropoietin on rabbit bone marrow cell suspensions.

The effects of an erythropoietin (Ep)-rich plasma fraction and of a commercial preparation of purified Ep (Step I) on the cyclic adenosine monophosphate (cAMP) levels of suspended rabbit bone marrow cells at different incubation times (up to 10 min) were investigated. Both Ep preparations caused an early increase in cAMP concentration: using the plasma fraction a significant increase was found at the 6th, 7th, 9th and 10th min of incubation, whereas the purified Ep produces a significant increase at all incubation times, starting from 1 min. No effect was observed following incubation with fluorescein isothiocyanate (FITC)-inactivated Ep. These findings are discussed and possible role of cAMP as the intracellular messenger for Ep action is suggested.

Animals↗
PubMed1975

Responses of spinal neurons to iontophoretically applied prostaglandin E1 in the frog.

Prostaglandin E1 (PGE1) has been tested by microiontophoresis on interneurons and motoneurons in the isolated spinal cord of the frog. PGE1 action was almost exclusively excitatory, regardless of the cell type and the test condition used. In general, the excitatory response had rapid onset and termination, and was susceptible to tachyphylaxis. Responsive interneurons were scattered throughout the tissue, and the incidence of responses showed no obvious relation to the mono- vs. polysynaptic connection of cells to primary afferents and descending fibers of the lateral funiculus. PGE1-sensitive interneurons were encountered more often in preparations from summer than from winter animals. These findings, coupled with the demonstration of prostaglandin biosynthesis and catabolism in the tissue, suggest that PGE1 plays a role in the normal function of spinal neurons. The intimate mechanism of PGE1 action remains to be elucidated.

Animals↗