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Biomedical subjects

P Boscolo

Publications and source records attributed to P Boscolo.

At least 55 records · Page 3Linked to original sources
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↗
PubMed1977

[Urinary kallikrein and risk of lead poisoning].

Urinary kallikrein is an enzyme, probably originated in the kidney, which acts on plasma kininogen to produce kallidin, the decapeptide precursor of bradykinin, and appears to be implicated in various forms of arterial hypertension. It is significantly decreased in workers exposed to lead showing no hypertension or other clinical signs of lead poisoning. In respect to measurement of ALA or other heme precursors the determination of urinary kallikrein seems to be able to detect a different, and perhaps in certain cases earlier, effect of lead intoxication on enzyme functions.

Adult↗
PubMedDate not supplied

Effects of long-term cadmium exposure on the testis of rabbits: ultrastructural study.

Six male rabbits received for 9 months drinking water containing 20 micrograms/ml of cadmium (Cd). At the end of the treatment, the Cd contents of kidney and testis were 175 +/- 34 and 0.8 +/- 0.2 micrograms/g wet weight, respectively. Ultrastructural examination by transmission electron microscopy (EM) showed that, in the Sertoli cells, the size of the lysosomes was increased; spermatogenetic cells, vessels and Leydig cells showed no significant alterations. Observations with both transmission and scanning EM did not evidence changes in the blood-testis barrier, but our results do not exclude that male fertility may be affected by chronic exposure to cadmium.

Animals↗
PubMedDate not supplied

Neurobehavioral functions, serum prolactin and plasma renin activity of manganese-exposed workers.

Objective of this study was to assess effects of manganese (Mn) exposure on 56 workers employed in a Mn welding workshop of a machine building factory in Taiyuan (Shanxi Province, P.R. China) for a mean period of 16.1 years. The mean air Mn level in the workshop was 138.4 microg/m3. Neurobehavioral Core Test Battery (NCTB), including the Profile fo Mood States, (POMS), was performed. Blood pressure (BP) increase following immediate stand-up (BP-IS), serum prolactin (PRL) and plasma renin activity (PRA) in supine position were also determine. Most of the NCTB scores of the Mn-exposed workers were lower than those of controls, while the POMS scores were higher, indicating a Mn-induced impairment of neurophysiological functions and a deflection of mood towards negative emotion states. PRL values of the Mn-exposed workers were higher than those of the controls. BP-IS of Mn-exposed workers was significantly lower than that of the controls. PRA of the same workers was augmented more that 200%. In the Mn-exposed workers, the higher PRL values are possibly due to a reduced inhibitory effect on pituitary lactotrope cells by the tubero-infundibular dopamine system; the decreased BP-IS was referred to imbalance between the sympathetic and parasympathetic activities, whereas the higher basal PRA was thought to depend on neuroendocrine changes (including increased central sympathetic tone) and/or on a direct effect of Mn on renal juxta-glomerular cells. On the whole, this study demonstrates that occupational Mn exposure is responsible for neurobehavioral changes coexisting with alterations of neuroendocrine and humoral systems.

Adult↗
PubMedDate not supplied

Clastogenic but not apoptotic effects on human artery endothelial cells by concentrations of inorganic lead inhibiting their nitric oxide production.

Human coronary artery endothelial cells (HCAEC 5156) were cultured as monolayers and exposed to concentrations of lead (as acetate, Pb) in the culture medium similar or lower than those commonly found in the blood of human beings occupationally or environmentally exposed to this element. Only at the concentration of 200 ng/mL, Pb reduced growth rate of HCAEC 5156 cells starting from the 3rd day and up too the 5th day of incubation. On the other hand, Pb (0.2, 2 and 200 ng/mL) increased concentration-dependently micronuclei formation in binucleated HCAEC 5156 cells, as it was shown by the cytokinesis-blocked micronucleus assay (CMBN assay) carried out after 48 hours of exposure to the metal. However Pb was unable, at all the above concentrations to induce apoptosis in the HCAEC 5156 cells following a 48 hour-exposure, as shown by an electorphoretic apoptotic DNA fragmentation test. Moreover, Pb (2 and 200 ng/mL) reduced significantly the concentration of nitric oxide (NO, determined analytically as L-citrulline) in both culture medium and cytosol of HCAEC 5156 cells following a 7 day-exposure to the element. Results were discussed also in relation so evidences of other studies reporting genotoxic and/or apoptotic effects of Pb on various cell types at very elevated dosages of concentrations. The observed clastogenic effects of Pb were explained through a series of mechanisms involving interactions between oxygen reactive species and NO and/or reduced NO synthesis in the endothelium, thus leading to a depressed NO bioavailability. This research first shows that Pb is provided with clastogenic but not apoptotic effects on cultured human endothelial cells. It was emphasized that such effects are induced by Pb concentrations similar to those commonly found in blood and tissues of laboratory animals showing Pb induced cardiovascular and/or neuropsychological alterations.

Apoptosis↗
PubMedDate not supplied

Occupational asthma due to low molecular weight agents.

Occupational asthma is defined as variable airflow obstruction and airways hyperresponsiveness caused by exposure to agents present in the workplace. Low molecular weight agents such as isocyanates, aldehydes, anhydrides, colophony, dyes, persulphate, amines, acrylates and metals are steadily increasing as causative agents of occupational asthma. Isocyanates, aldehydes and anhydrides my cause sensitisation through an IgE mediated response in some workers. These agents act as haptens which combine with a carrier protein to form a complete antigen. Assays for the detection of specific IgE are standardized for very few agents and have a good specificity, but poor sensitivity. The diagnosis of occupational asthma relies not only on a suggestive hystory showing that asthma is caused or exacerbated specifically by work exposure, but in most cases needs to be confirmed by objective means. Combined monitoring of lung function parameters, such as peak expiratory flow rate at the work site and non specific bronchial hyperresponsiveness during and away from exposure, is necessary. The "gold standard" for confirming a diagnosis in an individual worker still remains the specific bronchoprovocation test, which has now reached a high degree of sensitivity, specificity and reproducibility for agents such a s isocyanates. In occupation asthma due to low molecular weight agents there are no individual risk factors which could predict the susceptibility to develop the disease. The primary prevention is based on appropriate interventions tn the workplace. The strict medical surveillance of workers may allow the early diagnosis and removal from further exposure in order to prevent morbidity and disability.

Adult↗
PubMedDate not supplied

"In vitro" comparative immune effects of different titanium compounds.

Exposure to Ti compounds is today an occupational and environmental health hazard. Object of this study was to determine "in vitro" effects of different Ti salts on cultured human peripheral blood mononuclear cells (PBMC) proliferation and cytokine release. 10(-4) and 10(-7) M Ti compounds did not modify spontaneous PBMC proliferation. Ti dioxide (a biocompatible material and sunscreen component) did not exert effects on phytoemagglutinin (PHA) stimulated PBMC proliferation and on PHA stimulated IFN-gamma and TNF-alpha release from PBMC. On the other hand, 10(-4) M Ti oxalate (with wide industrial applications) and Ti ascorbate (used mainly in agriculture) inhibited about 70% the PHA stimulate PBMC proliferation; both these Ti compounds at 10(-4) and 10(-7) M concentrations significantly inhibited TNF-alpha release, while only Ti oxalate inhibited that of IFN-gamma. Titanocene (used in chemotherapy) did no exert effects on PBMC proliferation but markedly inhibited IFN-gamma and TNF-alpha release. On the whole, this study demonstrates that Ti dioxide is not immunotoxic; Ti oxalate shows marked immunotoxicity; titanocene exerts selective toxicity on cytokine release but not on PBMC proliferation, while Ti ascorbate affects TNF-alpha release from PBMC but not iFN-gamma release. In conclusion, the data show that immunotoxicity fo Ti depends on speciation.

Adult↗