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Biomedical subjects

A Tedeschi

Publications and source records attributed to A Tedeschi.

At least 127 records · Page 7Linked to original sources
PubMed1987

Effects of silybin on histamine release from human basophil leucocytes.

1. Effects of a naturally occurring flavonoid, silybin, on histamine release from human basophils were examined, in order to assess the potential utility in the treatment of allergic disorders. 2. The f-met peptide and anti-IgE-induced histamine release was significantly (P less than 0.05) inhibited in a concentration-dependent fashion. Conversely, no significant (P greater than 0.05) effect on calcium ionophore A23187-induced histamine secretion was documented. The inhibitory activity was significantly (P less than 0.05) reversed by elevating extracellular calcium concentrations. 3. The anti-allergic properties of silybin can be reasonably ascribed to a membrane-stabilizing activity, possibly related to an interference in calcium influx. These results indicate that an in vivo evaluation of the anti-allergic activity of silybin would be worthwhile.

Adult↗
PubMed1987

Effect of nitrendipine on histamine release from human basophil leukocytes.

The effect of the new calcium antagonist nitrendipine on in vitro basophil activation was evaluated in 10 subjects. The histamine release induced by calcium ionophore A23187, f-met peptide and anti-IgE was inhibited, in a dose-dependent fashion, by nitrendipine in the concentration range of 1-100 microM. The activity of this calcium antagonist seems complex and related to an interference with calcium at multiple sites. At concentrations higher than 200 microM, nitrendipine causes histamine release from basophil leukocytes. This histamine secretion is likely to be due to a cytotoxic effect, since it is associated with an increase in LDH levels in the cell supernatant.

Adult↗
PubMed1987

Behavior and clinical relevance of histamine and leukotrienes C4 and B4 in grass pollen-induced rhinitis.

The release kinetics of histamine and leukotrienes C4 (LTC4) and B4 (LTB4) were investigated in nasal secretions of 10 patients with hay fever after antigen challenge. High levels of biologically active histamine were found in nasal washes from asymptomatic allergic and normal subjects. With repeated lavages, the amount of histamine recovered dropped markedly. Grass pollen challenge was followed by a significant (p less than 0.05) dose-dependent and time-limited (5 min) increase in histamine level in 7 of 10 patients; these values, however, were lower than those found in basal conditions. In 8 of 10 patients with hay fever, antigen challenge induced a significant (p less than 0.05) dose-dependent increase in LTC4 level, which persisted for 30 min. The LTC4 generation was well correlated with the appearance of allergic symptoms; LTB4 production was found in 2 patients only. A different pattern of symptoms was observed after in vivo nasal stimulation with histamine and LTC4. Histamine caused sneezing, itching, rhinorrhea, and nasal obstruction; conversely, the main symptom induced by LTC4 was a more pronounced and longer lasting nasal obstruction.

Adult↗
PubMed1987

IgE-mediated food allergy.

The behaviour of some immunologic parameters was studied in order to explain the presence or the lack of symptomatology in subjects with IgE specific to foods. In particular, we compared the levels of serum and salivary IgA and IgE antibody specific to apple in 33 patients allergic to birch and with anti-apple IgE, of whom 24 had oral allergy syndrome after eating apple and nine were apple tolerants. We found no differences in the IgE-related parameters such as levels of anti-apple IgE antibody in serum and secretions, mean size of apple skin prick test, and number of patients with a positive histamine release from peripheral basophils stimulated by apple. Similarly, we detected no statistically significant differences in serum and salivary total IgG and total anti-apple IgA antibody of the two groups. We could, however, observe a significantly higher anti-apple salivary IgA/anti-apple serum IgE and anti-apple salivary IgA/anti-apple serum IgA ratios and a significant correlation between the same parameters in tolerant patients when compared with the intolerants. These results seem to suggest that the presence of appropriate levels of secretory anti-apple IgA associated to anti-apple IgE might be one of the factors playing a key role in the prevention of clinical symptoms in atopic subjects.

Food Hypersensitivity↗
PubMed1987

Study of mediators of anaphylaxis in nasal wash fluids after aspirin and sodium metabisulfite nasal provocation in intolerant rhinitic patients.

Nasal histamine (H), leukotriene C4 (I-LTC4) and SRS-A activity were studied in seven aspirin-(ASA)-intolerant patients (AIR) with rhinitis and in five ASA-tolerant control patients with chronic rhinitis after nasal provocation (NP) with a lysine acetylsalicylate solution. The same parameters were also studied after metabisulfite (MBS) NP in four sulfite-intolerant patients with rhinitis and in six control patients with chronic rhinitis. In six ASA-intolerant subjects and in four controls, we studied the PGD2 levels in nasal washes after ASA NP 0.2 mL of lysine acetylsalicylate solution (10 mg/mL) was sprayed intranasally in ASA-intolerant patients and controls and a 25-mg/mL MBS solution in sulfite intolerant patients and controls. Nasal wash fluids were obtained using 5 mL of 0.15 M saline before and 7 1/2, 15, 30, and 60 minutes after nasal provocation. The nasal provocation with ASA induced itching and sneezing in four out of seven intolerant subjects. In this subgroup histamine values in nasal wash fluids were significantly higher versus the remaining ASA-intolerant patients at 30 and 60 minutes (P less than .05 and P less than .01, respectively) and versus controls at 60 minutes (P less than .01). We found significantly higher I-LTC4 (P less than .01) and SRS-A levels in nasal washes collected from ASA-intolerant subjects versus controls at 60 minutes after nasal provocation. There was no significant increase in the mean PGD2 values in either the ASA-intolerant or control groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aspirin↗
PubMed1986

Effect of calcium antagonists on histamine release from human basophil leukocytes.

The effect of calcium antagonists on basophil activation was investigated in 14 subjects. Verapamil, methoxyverapamil and diltiazem, in a concentration range of 1-100 microM, exert a concentration-dependent inhibition on the human basophil histamine release induced by calcium ionophore A23187, zymosan activated human serum and grass pollen allergens. This inhibitory effect is highly variable from subject to subject and from drug to drug. At concentrations higher than 200 microM, verapamil, methoxyverapamil and diltiazem induce a calcium independent histamine secretion from basophil leukocytes. This mediator release is associated with an increase in LDH levels in the cell supernatant and seems to be due to a cytotoxic effect.

Adult↗
PubMed1986

Functional evaluation of the basophil/IgE system in the cord blood.

Basophil releasability was studied in 24 cord blood samples from normal-term deliveries. The histamine content in cord blood basophils was similar to that of adult blood basophils. The response to IgE-independent degranulating stimuli such as calcium ionophore A23187 and zymosan-activated human serum was overlapping with that of normal adults. Conversely, a reduced releasability was observed after challenge with anti-IgE, even after sensitization with an IgE-rich serum. The IgE-dependent degranulation seems to be hampered by the low concentrations of circulating and cell-bound IgE antibodies. The number of IgE molecules bound to the specific receptors in cord blood basophils is significantly lower than in adult blood basophils.

Adult↗
PubMed1985

[Monolateral autoimmune exophthalmos in an euthyroid woman].

So-called "endocrine" ophthalmopathy may arise even in the absence of thyroid disorders since although these two nosographic and clinical conditions are both linked to closely inter-related organ-specific auto-immune responses, they may also present independently. After a review of the two clinical conditions, the case of an autoimmune ophthalmopathy unaccompanied, at least during a long observation period, by demonstrable functional thyroid alterations is reported. The case was also unusual because only one eye was affected.

Adult↗
PubMed1985

Reliability and usefulness of random fecal alpha 1-antitrypsin concentration: further simplification of the method.

The reliability of random fecal alpha 1-antitrypsin (FA-1-AT) concentration has been evaluated by comparing FA-1-AT values on random specimens and on concomitant 24-72 h fecal collections. In order to simplify the method, FA-1-AT data derived from lyophilized fecal samples were compared with those obtained from 37 degrees C heat-dried fecal samples. Random FA-1-AT concentration was assayed in 80 children with various gastrointestinal illnesses and 36 healthy age-matched controls. There was a close relationship between FA-1-AT values obtained from random samples and 1-day or 3-day collections. There was also a significant relationship between FA-1-AT values derived from the two different ways of drying the stools. Mean FA-1-AT values were statistically different when compared to the controls in the following groups of disorders: untreated and after-gluten-challenge celiac disease, post-enteritis syndrome, and cow's milk intolerance. The possible meanings of the abnormal FA-1-AT concentration in the various disorders are discussed. We conclude that FA-1-AT is a simple and reliable test for enteric protein loss. The simplification of the method proposed by us should reduce the cost of the test and moreover make it feasible in all laboratories.

Adolescent↗
PubMed1985

Complement anaphylatoxins in idiopathic mixed cryoglobulinemia.

Basophil activation, observed in patients with idiopathic mixed cryoglobulinemia, has been related to the complement anaphylatoxins C4a, C3a and C5a. In the present study the plasma levels of the complement anaphylatoxins have been evaluated in 21 patients affected with idiopathic mixed cryoglobulinemia. The plasma concentration of C3a desArg was significantly higher in the patients than in the healthy controls; conversely the plasma values of C4a desArg were significantly lower. C5a desArg was not detectable in plasma from any subject. The high plasma level of C3a desArg in our patients may suggest a role for C3a anaphylatoxin in 'in vivo' basophil activation. No correlation was found between the plasma concentrations of C3a desArg or C4a desArg, the amount of cryoprecipitate and the clinical activity of the disease.

Adult↗
PubMed1985

Characterization of T cell subsets in patients with atopic dermatitis using OKT monoclonal antibodies.

The distribution of T cell subsets has been studied by means of OKT monoclonal antibodies in 19 children with atopic dermatitis. In these patients a decreased percentage of circulating OKT4+ cells has been observed, while no difference has been found between atopic and normal subjects, regarding the percentages of circulating OKT8+ and OKT11+ cells. An increased OKT4+/OKT8+ ratio has been detected only in three children with a particularly severe and extensive atopic eczema.

Adolescent↗
PubMed1985

Influence of bromocriptine on plasma prolactin, human placental lactogen, beta-HCG and steroid hormones in early human pregnancy.

To study the role of prolactin in the regulation of the production of 17 beta-oestradiol, HPL, beta-HCG, progesterone, testosterone, delta 4-androstenedione and 5 alpha-dihydrotestosterone, 20 healthy women were given 5 mg of bromocriptine daily for two weeks between 7-9 weeks of normal pregnancy. Plasma HPRL, HPL, HCG, oestradiol, progesterone, testosterone, delta 4-androstenedione and 5 alpha-dihydrotestosterone levels were measured before and one and two weeks after the start of bromocriptine-application, and they were compared with those examined in control groups (18 women). Bromocriptine induced a significant HPRL depression at one week and two weeks. Other hormones, except progesterone, showed no significant differences between two groups. These data suggest that neither maternal hypoprolactinemia nor bromocriptine during normal early human pregnancy interfere with the normal synthesis of sex steroids.

Adolescent↗