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Biomedical subjects

V Silano

Publications and source records attributed to V Silano.

At least 37 records · Page 2Linked to original sources
PubMed1982

In vitro proliferation of lymphocytes from celiac children and their first-degree relatives in response to wheat gliadin-derived peptides.

Evidence is accumulating which indicates that immune reactions to gliadins are involved in the pathogenesis of celiac disease, as humoral- and cell-mediated immune responses to gliadins have been demonstrated in the jejunal mucosa and the peripheral blood of patients. An abnormal specific immunological response to gliadins is demonstrated not only in celiac children but also in their first-degree relatives. Seventy-eight percent of celiac patients, and 67, 87, and 100% of their fathers, siblings, and mothers, respectively, have a peripheral blood lymphocyte population reacting in vitro with a proliferation response to at least one of four peptide mixtures obtained from bread and durum wheat gliadins using a procedure simulating in vivo protein digestion. The specificity of this immunological hyperresponsiveness against wheat gliadins is shown by two sets of data: (a) Lymphocytes from celiac children and their relatives were much less sensitive to peptides from rice prolamin and not at all sensitive to peptides from wheat albumins. (b) Only 7% of 30 adult controls had a proliferative response of their peripheral lymphocytes to wheat gliadin peptides. It is not known at this time if healthy relatives of celiac patients mount an immune response against the intestine in vivo. However, it is possible that the presence of lymphocytes reactive to wheat gliadin peptides in apparently healthy relatives of celiac patients may explain why these relatives develop histologic evidence of celiac disease when their gluten intake is increased (Doherty M, Barry RF. Lancet 1981;1:517-20).

Albumins↗
PubMed1982

Effects of gliadin-derived peptides from bread and durum wheats on small intestine cultures from rat fetus and coeliac children.

Peptic-tryptic-cotazym (PTC) digests were obtained, simulating in vivo protein digestion, from albumin, globulin, gliadin and glutenin preparations from hexaploid (bread) wheat as well as from diploid (monococcum) and tetraploid (durum) wheat gliadins. The digest from bread wheat gliadins reversibly inhibited in vitro development and morphogenesis of small intestine from 17-day-old rat fetuses, whereas all the other digests (obtained both from nongliadin fractions and from gliadins from other wheat species) were inactive. The PTC-digest from bread wheat gliadins was also able to prevent recovery of and to damage the in vitro cultured small intestinal mucosa from patients with active coeliac disease (gluten-induced entheropathy). The PTC-digest from durum wheat gliadins caused a much less adverse effect on this human pathologic tissue culture system.

Animals↗
PubMed1981

Toxicology investigations with cell culture systems.

This review concerns some of the cell culture systems that are most frequently used in toxicology investigations. In particular, it sets out to evaluate the effectiveness of these cell culture systems in assessing the toxic potential of chemicals. Metabolic studies and general and specific toxicology investigations are highlighted. Specific toxicology investigations relate to the effects of the tests substances on the highly specialized functions typical of the cell systems chosen. The general toxicology investigations include most of the other studies where differentiated or undifferentiated cells have been used to evaluate the effects of the tested substances on common basic biochemical processes essential for life. Lastly, we have attempted to focus attention on the most promising applications of cell cultures in toxicology studies for the near future and to identify those areas where further research is needed. Because of the several excellent reviews that already exist, we have decided not to consider cell cultures utilized in screening potential mutagens and carcinogens. We have also excluded investigations of drug therapeutic effects and action mechanisms of drugs.

Animals↗
PubMed1980

Interaction of wheat monomeric and dimeric protein inhibitors with alpha-amylase from yellow mealworm (Tenebrio molitor L. larva).

The highly purified alpha-amylase from Tenebrio molitor L. larva (yellow mealworm) reversibly combines with two closely related homogeneous glycoprotein inhibitors, one dimeric (termed 'inhibitor 0.19') and one monomeric (termed 'inhibitor 0.28'), from wheat flour. As established by means of difference spectroscopy and kinetic studies, molar combining ratios for the amylase--inhibitor-0.19 and amylase-inhibitor-0.28 complexes were 1:1 and 1:2 respectively. Two amylase--inhibitor-0.19 complexes with slightly different retention volumes on Bio-Gel P-300 and only one amylase--inhibitor-0.28 complex were observed. Dissociation constants of the amylase--inhibitor-0.19 and amylase--inhibitor-0.28 complexes were 0.85 nM and 0.13 nM respectively. A strong tendency of both complexes to precipitate under an ultracentrifugal field was observed; the minimum molecular weight calculated for the two complexes under such conditions was approx. 95 000. The two complexes showed difference spectra indicating involvement of structurally related or identical tryptophyl side chains in the binding of inhibitors 0.28 and 0.19 to the amylase. A model summarizing the main features of the inhibition of the insect amylase by the two wheat protein inhibitors is proposed.

Animals↗
PubMed1979

Human health effects from accidental release of tetrachlorodibenzo-p-dioxin (TCDD) at Seveso, Italy.

This paper is a progress report of the epidemiologic work carried out under the supervision of the Lombardy Regional Authority during the two years elapsed from the accident in a TCP-producing factory (ICMESA) in Meda (Italy), which resulted in the contamination of several towns of a large, densely populated area called the Brianza di Seveso with a total population of 220,000 inhabitants. A wide follow-up program is in progress in the Seveso area; it includes a clinical screening of the population living in the contaminated area and longitudinal and systematic health control of different groups at risk; a long-term morbidity cohort study has been also undertaken. TCDD exposure following the ICMESA accident resulted in an increased chloracne frequency. Neurologic examinations showed both signs of idiopathic subclinical neurologic damage and cases of clinically detectable idiopathic polyneuropathy in adults. A limited percentage of idiopathic hepatomegaly was reported to be present on clinical investigation; no information, however, is given on the criteria by which the hepatomegaly was investigated. Some alterations were observed in some exposed people in one or more liver tests (mainly transaminases and gamma-GT). So far, immunologic investigations, cytogenetic examination and embryomorphology analysis on cases of therapeutical or spontaneous abortions have not given abnormal results.

Abortion, Spontaneous↗
PubMed1979

Toxicity of wheat flour proteins and protein-derived peptides for in vitro developing intestine from rat fetus.

A peptic-tryptic-cotazym (PTC) digest of a crude wheat gliadin preparation was obtained under experimental conditions simulating in vivo protein digestion and then fractionated into 10 peaks by ion-exchange chromatography. PTC-gliadin digest and one of its subfractions (coded as fraction 9 according to its elution pattern) were very active in inhibiting in vitro development and morphogenesis of small intestine from 17- and 18-day-old rat fetuses, whereas they were harmless for the culture of jejunum from 21-day-old fetuses. PTC-digest also induced extensive tissue degeneration and necrosis of in vitro cultured small intestinal mucosa from patients with active celiac disease (gluten-induced entheropathy), but did not cause any detectable effect on histologically normal human small intestinal mucosa. Some wheat albumin and gliadin fractions were also tested on in vitro developing small intestine from 17-day-old rat fetus. Among all the tested protein fractions, only one gliadin fraction (coded as alpha 10-gliadin from its gel electrophoretic mobility) exhibited a toxic effect; morphologic alterations induced by alpha 10-gliadin were similar to those induced by PTC-digest and fraction 9.

Albumins↗