Biomedical subjects

P Boscolo

Publications and source records attributed to P Boscolo.

78 records · Page 5Linked to original sources

PubMedDate not supplied

Lymphocyte subpopulations of workers in a plant producing plastic materials (preliminary study).

Lymphocyte subpopulations were studied in 31 men working in a plant producing plastic materials in relation with control groups of similar age and smoking habit. 8 workers (group A) were exposed to solvents (mainly methylethylketone and dimethylformamide), 8 men (group B) to dust containing particles of calcium carbonate, polyvinylchloride, phtalates, unsaturated oils, paraffin wax, iron oxides, titanium bioxides, barium, zinc and lead and 15 men (group C), working in the same department as group B, were studied after a period of 16 months during which lead chromate was employed in the preparation of colors. The lymphocyte subpopulations were normal in group A, while in B there was a significant increase of HLA-DR + cells (monocytes, B and activated T lymphocytes). In group C, T helper/inducer lymphocytes (mainly CD4(+)-CD45RO- "virgin" lymphocytes), CD19+ B lymphocytes, CD3-HLADR+ and CD3-CD25+ (activated B lymphocytes and monocytes) were significantly reduced without changes of serum IgM, IgG and IgA. Highly significant correlation was found between B lymphocytes (reduced in the workers about 40%) and CD4(+)-CD45R0+ "memory" lymphocytes (reduced about 20%). Moreover, blood lead (correlated with urinary chromium) showed a highly significant negative correlation with the B lymphocytes. This study demonstrates that combined exposure to toxic agents produces specific modifications in the lymphocyte subsets without changes in immunoglobulins and confirms the results of previous researches showing that the exposure to lead or chromate induces reduction of lymphocytes in the peripheral blood.

Adult↗

PubMedDate not supplied

Vanadate and cardiovascular system.

Rats were given 1, 10, 40, or 100 ppm of vanadium in drinking water for seven months, while rabbits received 1 ppm of vanadium (as sodium metavanadate, NaVO3) in drinking water for twelve months. Rats developed arterial hypertension through complex effects of vanadium on central neurogenic pathways, central and periferal catecholaminergic mechanisms, specific autacoidal systems (kallikrein-kinin, reninangiotensin-aldosterone, enkephalin ones), and effectors (vessels and heart). The above effects of vanadium were in part confirmed in the rabbits which, however, did not show arterial hypertension since the increase of vascular resistance was counteracted by a reduction of both cardiac inotropism and cardiac output. Vanadium was accumulated in tissues as vanadyl; higher levels were found in the bone and in the kidney, but relevant amounts were determined in aorta, heart and brain. There was evidence, in the rabbits, that vanadium reduces synthesis and/or release of nitric oxide, the endothelium-derived vasodilating factor, likely through a reduced formation from bradykinin. The functional, analytical and morphological results obtained in this study show that chronic exposure to vanadium induces arterial hypertension by mechanisms only in part related to the levels and times of exposure, and to the species.

Animals↗

PubMedDate not supplied

[Immuno-histopathologic changes in the gastrointestinal mucosa in patients with nickel contact allergy].

The study concerns the histological and immunohistochemical findings of the gastrointestinal mucosa of 20 patients (group A) suffering from contact allergic dermatitis (CAD) to Ni, with symptom recrudescence due to food ingested Ni. Results were compared with those observed in 20 patients suffering from CAD to Ni (group B), without sensitivity to food ingested Ni, and in 20 normal subjects (controls). The sensitivity to food ingested Ni, as suggested by history, was demonstrated by placebo-controlled oral-Ni challenge. The biopsies for histological and immunohistochemical study were performed during endoscopy and obtained from the antrum and from the duodenal mucosa. In the biopsies obtained from 16 of group A patients there was evidence of inflammatory infiltrate of lymphocytes and plasma cells with oedema and vasodilation in the lamina propria. Slight flattening of the villi and enlongation of the crypts were concomitant. These findings were light in the 4 patients of group A and in 11 of group B and instead were absent in the remaining group B patients and in the controls. Immunohistochemically, lymphocytes in the lamina propria were prevalently CD20 + (B cells) and CD4 + (Th cells), some were CD45RO + (memory) and finally few CD8 + (Tc/s cells). CD45RO + cells was found in cluster in patients of group A and in 4 of group B, whereas in the others were isolated. Since some studies have shown that immunological pattern of skin reaction to Ni is characterized by increased CD45RO + cells, it may be hypothesized that in patients suffering from CAD to Ni, the sensitivity to food-ingested Ni may be induced by a type IV immunological reaction in the gut.

Adolescent↗

PubMedDate not supplied

[Neurohumoral, autacoid and transductional mechanisms in the cardiovascular effects of vanadate: histochemical correlations].

Rabbits given 1 ppm of vanadate in drinking water for twelve months showed (a) increased plasma levels of catecholamines (b) reduction of the arterial concentration of nitric oxide (c) lower activity of urine kallikrein and higher activities of urine kininases I and II and enkephalinase (d) reduced cardiac inotropism and augmented total peripheral resistance, with unchanged blood pressure levels (e) accumulation of the metal in the aorta and cardiac ventricles. Monoaminooxidase and glucose-6-phosphate dehydrogenase activities were increased by vanadate in both kidney and liver and that of NADH-diaphorase in the kidney, in which NADPH-diaphorase activity was reduced. Some of the above results were also obtained in rats given 10 and 40 ppm of vanadate in drinking water for six-seven months; these animals showed arterial hypertension and reduced activity of Na, K-ATPase in the kidney. Vanadium appears to act on the cardiovascular function through selective neurohumoral, autacoidal and transductional mechanisms only in part depending on the species.

Animals↗

PubMedDate not supplied

[Trace elements in biological samples and immunologic parameters in environmentally exposed populations (preliminary study)].

In non-smoking policemen from a town of Central Italy, blood CD4+ lymphocytes were reduced and CD8+ were increased as compared with a control group. This immunological alteration was not evident in the smoking policemen. Urine lead (marker of exposure to toxic agents produced by traffic) and blood natural killer (NK) CD16+ lymphocytes as well as serum copper and HLA-DR+ cells (B, T, NK activated lymphocytes and monocytes) were significantly correlated in the whole group of 42 examined subjects. Another study was performed on 15 healthy men, occupationally not exposed to toxic agents and living in a suburban area. Their urine lead, was positively correlated with the serum IgA immunoglobulins and negatively correlated with blood CD5(+)-CD19+ (a B subset bearing the T CD5 antigen) lymphocytes. On the contrary, urine chromium was negatively correlated with serum IgA and positively correlated with CD16(+)-56+ NK and CD5(+)-CD19+ B lymphocytes as well as with HLA-DR+cells. Serum zinc was also correlated with total HLA-DR+and CD3-HLA+DR+ (activated B and NK lymphocytes and monocytes) cells. These later data suggest that only zinc and copper but also trivalent chromium (to which normal population is mainly exposed in ordinary environmental conditions) may play a role in the mechanisms regulating the immune response.

Air Pollutants, Occupational↗

PubMedDate not supplied

[Allergic contact dermatitis to nickel: modification of receptor expression on peripheral lymphocytes of women after oral provocation tests (preliminary data)].

Blood lymphocyte subset evaluation was performed before after oral challenge with 10 mg of Ni, in 9 healthy women and in 15 allergic to Ni. Following challenge, 7 allergic showed a flare up of eczema and/or urticaria. In the controls, CD4+ lymphocytes were modified 24 hours after Ni challenge: CD4+/CD44RO- "virgin" cells were reduced while CD4+/CD45RO+ "memory" cells increased. The allergic women, not sensitive to oral Ni, showed an increase of B lymphocytes after the test. On the contrary, the oral Ni reacting patients presented a reduction of monocytes 4 hours after Ni ingestion and marked reduction (ranging from 20 to 50%) of T and B lymphocytes after 24 hours. These significant T and B lymphocytes changes suggest a migration of the cells in peripheral tissues, likely skin and GUT mucosa.

Administration, Oral↗