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Biomedical subjects

P Boscolo

Publications and source records attributed to P Boscolo.

At least 19 recordsLinked to original sources
PubMed1992

Zinc and copper in tissues of rats with blood hypertension induced by long-term lead exposure.

Male Sprague-Dawley rats received for 14 months 0, 15, 30 and 60 micrograms/ml of lead in drinking water. Both blood pressure and tissue lead were augmented with a dose-response effect, while cardiac inotropism was increased only in the rats treated with 60 ppm of lead. In the exposed animals, zinc and copper were unchanged in kidneys and testicles and augmented in the brain, while copper, but not zinc, was reduced in the heart. These data suggest a possible relation between the modifications of copper and zinc metabolism and the effects of lead on cardiovascular homeostasis.

Administration, Oral↗
PubMed1992

Renal mechanisms in the cardiovascular effects of chronic exposure to inorganic mercury in rats.

Male weanling Wistar rats received 200 micrograms/ml of mercury (Hg), as HgCl2, in drinking water for 180 days. At the end of the treatment, systemic arterial blood pressure was augmented, cardiac inotropism was reduced, and heart rate was unchanged. Light and electron microscopical studies of the kidney showed a mesangial proliferative glomerulonephritis in about 80% of the glomeruli. Tubular cells showed reduction of the acid phosphatase activity, which was related to functional abnormalities of the lysosomes. In the 24 hour urine samples of the Hg exposed rats, there was slight reduction of kallikrein activity, but evident proteinuria was not present in all samples. Plasma renin activity was reduced, that of angiotensin I-converting enzyme was augmented, and plasma aldosterone concentrations were unchanged. Mercury was accumulated mostly in the kidney of the Hg treated animals; and the content of Hg in the heart was higher than in the brain. These data show that chronic exposure to Hg acts on the kidney with complex mechanisms of toxicity; these contribute to modify systemic haemodynamics.

Animals↗
PubMed1988

Ultrastructure of the testis in rats with blood hypertension induced by long-term lead exposure.

Male Sprague-Dawley rats received 60 micrograms/ml of lead (as acetate) in drinking water for 18 months. Their blood pressure and cardiac inotropism were increased. Lead was augmented in blood, kidney and brain, but not in testis. Examination by light microscopy of the organs did not reveal alterations. Ultrastructural examination of the testis with both transmission and scanning electron microscopy (EM) did not evidence modifications in the external part of the seminiferous tubules, in the spermatogenetic cells and in the connective tissue including the Leydig cells; only Sertoli cells presented increased size of lysosomes.

Animals↗
PubMed1988

Neurohumoral blood pressure regulation in lead exposure.

Previous human studies demonstrated that lead exposure may modify the metabolism of catecholamines and of hormones controlled by the hypothalamo-pituitary axis and may affect the kallikrein-kinin system. This paper reports unpublished data on the plasma renin activity of lead-exposed workers; these results are in agreement with those of previous human and experimental studies suggesting that the synthesis or release of renin is increased after short and moderate exposure to inorganic lead and reduced whenever the exposure is prolonged. Previous experimental investigations demonstrated that lead may act on the cardiovascular system, with effects on the renin-angiotensin system, on the reactivity to stimulation of peripheral catecholaminergic receptors, on sympathetic and vagal tone, and on reactivity to the stimulation of baroreceptors. This paper reports the results of a study on male Sprague-Dawley rats that received 0, 15, 30, and 60 micrograms/mL of lead in drinking water for 18 months. Blood pressure was increased in the rats receiving 30 and 60 ppm of lead; cardiac inotropism was augmented only in those receiving the higher dose of the metal, and heart rate was not modified. Cardiovascular responses to agonists indicated that lead exposure affects the renin-angiotensin system and induces sympathetic hyperactivity by acting on central and peripheral sympathetic junctions increasing the responsiveness to stimulation of alpha 2-adrenoreceptors and by increasing the reactivity to stimulation of cardiac and vascular beta-adrenergic and dopaminergic receptors. The cAMP-dependent availability of Ca2+ for contractile mechanisms of the cardiovascular muscle cells was affected by lead.

Animals↗
PubMed1988

[Health status of journalists and organization of work in a national daily newspaper].

A multidisciplinary investigation was performed on 173 reporters (53 men and 20 women) of a newspaper. The microclimate and illumination conditions of the main seat, in which the use of VDT was beginning, were satisfactory, although not all the instruments were correctly adjusted. A very low percentage of reporters working in the main center was suffering from arterial hypertension indicating the presence of the "healthy worker effect". The values of plasma cortisol and arterial blood pressure of 10 reporters of the main seat, except two cases, changed normally during the evening hours. It is to point out that among the reporters there was significant correlation between spondylosis and astigmatism. The psychological investigation evidenced that the reporters were aggressive, eager of success and with constant attention. The EMG biofeedback demonstrated in the reporters with a more prolonged period of employment nervous tension and difficulty in relaxing. Particularly, in the reporters of the main center, the Stait-Trait Anxiety Inventory was more altered than in those of the peripheral seats.

Adult↗
PubMed1988

[Postoperative radiotherapy in the treatment of breast tumors. Evaluation of a 5-year case series].

Between January 1981 and December 1985, 364 female patients underwent surgical treatment for breast cancer in Mestre General Hospital. The pathological stage of the disease was stage I in 60 patients, stage II in 215 patients, stage III A in 30 patients, stage III B in 44 patients and stage IV in 15 patients. The patients with T1-T2 N0 lesions located in the outer quadrants received no additional treatment after surgery, while the others received adjuvant therapy. The patients with stage-IV disease (M+) were treated with chemo and/or hormonotherapy. All patients were followed for an average of 33 months up to December 1986 (range 1-71 months). Local-regional relapses developed in 17 patients, 15 on the chest wall and 2 in the drainage lymph nodes (only 7 within the previously-treated area). A 5-year actuarial survival rate was observed of about 78%, and 66% of relapse-free survival, in the whole group of patients (100% and 92% in stage I; 92.5% and 76% in stage II; 51% and 33% in stage III A; 32% and 19% in stage III B; 31% in stage IV, respectively). As far as our series of patients is concerned, the massive involvement of axillary lymph nodes seems to be the most adverse prognostic factor in survival rates. Even though the short follow-up does not allow definitive conclusions to be drawn, the authors believe such loco-regional treatments as surgery and radiation therapy to be extremely important in the local control of breast cancers, as well as in the patients' survival in the long run.

Adult↗
PubMed1986

Mechanisms of cardiovascular regulation in male rabbits chronically exposed to cadmium.

Male rabbits received 20 micrograms/ml of cadmium in drinking water for nine months. At the end of the treatment aortic vascular resistance was increased, whereas maximum rate of increase in left ventricular pressure, aortic blood flow, stroke volume, cardiac output, left ventricular minute work, and left ventricular stroke work were reduced. Arterial blood pressure, heart rate, and the index of myocardial oxygen consumption were not modified. The exposed rabbits also showed reduced pressor responses to vagotomy, increased cardiovascular responses to angiotensin I and II and isoprenaline, and lower responses to serotonin and guanethidine; the bradycardia induced by clonidine was augmented; the cardiovascular effects of bilateral carotid occlusion, hexamethonium, phenylephrine, histamine, acetylcholine, tyramine, papaverine and verapamil were unaltered. In the treated rabbits cadmium was appreciably higher in the kidney than in the heart; however, renal concentrations of cadmium were lower than those reported as critical for workers exposed to cadmium. Zinc was increased in the kidney but not in the heart, whereas copper remained unchanged in the examined organs. In rabbits treated with cadmium the increased aortic vascular resistance and the reduced myocardial contractility contribute to preserve a haemodynamic equilibrium without alteration of blood pressure and heart rate; the question of whether a similar condition may be present in people exposed to cadmium with normal cardiovascular parameters is discussed.

Animals↗
PubMed1985

Metabolic fate and cardiovascular effects of arsenic in rats and rabbits chronically exposed to trivalent and pentavalent arsenic.

Male rats and female rabbits exposed for eighteen and ten months, respectively, to 50 micrograms/ml of trivalent arsenic (As III) in drinking water showed reduction of stroke volume (SV) and cardiac output (CO) and increase of vascular resistance (VR), while no cardiovascular change was observed in male rats receiving 50 micrograms/ml of pentavalent arsenic (As V) for eighteen months. The exposed animals showed specific alterations in some neurohumoral and effector mechanisms regulating cardiovascular function (CF). Elevated levels of urinary As were found in all treated groups. However, there were significant differences in the urinary levels of dimethylarsenic acid (DMA), monomethylarsenic acid (MMA) and inorganic As, which depended on both animal species and the valency state of As. Thus, As(III) was methylated to a greater extent than As(V) in rats, with less elimination of inorganic As, while rabbits had a lower capacity to methylate As and to retain As in tissues than rats. Either cardiovascular effects or metabolism of As seemed to depend on its valency state and animal species.

Animals↗
PubMed1985

Long-term exposure to cadmium and cardiovascular alterations in the rabbit.

Some mechanisms regulating cardiovascular function (CF) were investigated in male rabbits exposed for ten months to 20 micrograms/ml of cadmium (Cd) in drinking water. Cd reduced cardiac inotropism (CI), increased aortic vascular resistance (AVR) and altered cardiovascular reactivity by acting on renin-angiotensin, serotonin, sympathetic and vagal parasympathetic systems. Cd levels were higher in the aorta than in the heart. Renal Cd content was lower than that reported as critical for Cd-exposed workers. Zinc (Zn) was increased only in the kidney and copper (Cu) was unchanged in the organs studied. It was shown that humoral, neurogenic and metabolic mechanisms are involved in the Cd-induced alterations of CF.

Animals↗
PubMed1978

Urinary kallikrein activity of workers exposed to lead.

Two groups of men of different age ranges and with the same period of lead exposure were selected for study in a recently opened car-battery factory. Two other groups of age-matched men, not exposed to heavy metals in their work, were used as controls. Morning urines were collected from control and exposed groups for determination of urinary kallikrein activity, urinary delta-amino-levulinic acid (ALA) and lead levels. The environmental lead levels and the urinary ALA and lead values indicated that exposure in the factory was not heavy. The older group of lead-exposed workers showed greatly reduced urinary kallikrein activity compared with that of the age-matched controls. In contrast, the younger group did not show any significant alteration in urinary kallikrein excretion.

Adult↗
PubMed1978

Glucose-6-phosphate dehydrogenase in kidneys of lead-poisoned rats and adrenalectomized rats.

Glucose-6-phosphate dehydrogenase (G6PDH) activity, assayed biochemically, was significantly increased in kidney homogenates of lead-poisoned rats when compared with controls. Histochemically, G6PDH activity was greatly increased both in the distal tubules and the macula densa, but showed no significant changes in the proximal tubules. Biochemical assay of G6PDH in kidney homogenates of adrenalectomized rats was three times that in control animals. In this condition also, histochemical staining showed G6PDH activity to be increased in both macula densa and distal tubules. This demonstrates an increase in G6PHD in two completely different experimental conditions and suggests that the distal renal tubule in the rat might operate in functional unity with the macula densa.

Adrenalectomy↗
PubMed1978

[Urinary kallikrein in cadmium-exposed workers].

The urinary kallikrein activity was determined in a group of 20 young workers exposed to cadmium and to lower concentrations of lead and other toxic agents. Two of them were suffering from labile hypertension. The urinary kallikrein activity of exposed workers was found to be reduced by more than 80% in comparison with a control group.

Adult↗