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C Ortolani

Publications and source records attributed to C Ortolani.

At least 37 records · Page 2Linked to original sources
PubMed1999

Complete amino acid sequence determination of the major allergen of peach (Prunus persica) Pru p 1.

The major protein allergen of peach (Prunus persica), Pru p 1, has recently been identified as a lipid transfer protein (LTP). The complete primary structure of Pru p 1, obtained by direct amino acid sequence and liquid chromatography-mass spectrometry (LC-MS) analyses with the purified protein, is described here. The protein consists of 91 amino acids with a calculated molecular mass of 9178 Da. The amino acid sequence contains eight strictly conserved cysteines, as do all known LTPs, but secondary structure predictions failed to classify the peach 9 kDa protein as an 'all-alpha type', due to the high frequency of amino acids (nine prolines) disrupting alpha helices. Although the sequence similarity with maize LTP is only 63%, out of the 25 amino acids forming the inner surface of the tunnel-like hydrophobic cavity in maize ns-LTP 16 are identical and 7 similar in the peach homolog, supporting the hypothesis of a similar function.

Allergens↗
PubMed1998

Sensitization to the major allergen of Brazil nut is correlated with the clinical expression of allergy.

BACKGROUND: Only a few studies have investigated the clinical role of food allergens, especially the relationship between sensitization to a given allergen and occurrence of adverse reactions when eating the relevant food item. OBJECTIVE: This study evaluated the clinical role of the allergens of Brazil nut by comparing the patterns of IgE binding in sera from 11 patients with anaphylaxis after eating Brazil nuts with those from 10 subjects with no symptoms to this food item. Both groups had specific IgE to Brazil nut. METHODS: Allergens in the in-house extract of Brazil nut were identified by SDS-PAGE/immunoblotting, the major allergen was purified by HPLC, and its N-terminal sequence was determined by a protein sequencer. RESULTS: SDS-PAGE/immunoblotting detected a number of allergenic components with molecular weights ranging from 4 to 58 kd. All sera from symptomatic patients recognized a 9-kd allergen corresponding (as established by amino acid sequencing) to a 2S albumin already described as a major allergen of Brazil nut, whereas the other allergens each bound IgE from less than 50% of sera. No sera from asymptomatic subjects showed IgE binding to the 9-kd allergen, but they did recognize components from 25 to 58 kd, which are minor allergens. CONCLUSIONS: These findings indicate that the allergen underlying clinical reactions to Brazil nut is a 2S albumin of 9 kd and that in vitro reactivity to this allergen identifies subjects who react in vivo to ingestion of this food.

2S Albumins, Plant↗
PubMed1998

Identification of actinidin as the major allergen of kiwi fruit.

BACKGROUND: Allergic reactions to fruits and vegetables are among the most frequent food allergies in adults. Kiwi fruit (Actinidia chinensis) is commonly involved, causing local mucosal, systemic, or both types of symptoms by an IgE-mediated mechanism. In a previous study on 30 patients allergic to kiwi, we identified a major allergen of 30 kd against which all sera tested clearly reacted. Other allergens were detected at 12, 24, and 28 kd. OBJECTIVE: The aim of this study was to fully characterize the major kiwi fruit allergen of 30 kd. METHODS: Allergens were separated and purified by high-performance liquid chromatography with anion-exchange columns. The purity of the single proteins was checked by sodium dodecylsulfate-polyacrylamide gel electrophoresis, and their allergenicity was checked by immunoblotting with a pool of sera from patients allergic to kiwi. The allergens were characterized by isoelectrofocusing and amino acid sequencing, and periodic acid-Schiff stain was used to detect glycoproteins. RESULTS: Proteins of 30, 28, 24, and 17 kd were purified by high-performance liquid chromatography. IgE binding indicated the 30 kd protein, which showed an isoelectric point of 3.5, as the major allergen of kiwi. Determination of its partial amino acid sequence and comparison with the Swiss Protein Bank showed that this was actinidin, the main protein component of kiwi. The 24 and 28 kd proteins had the same N-terminal sequence, which did not correspond to any known protein. The 17 kd protein had a blocked N-terminal sequence. CONCLUSIONS: These results demonstrate that the major allergen of kiwi fruit, Act c 1, is actinidin, a proteolytic enzyme belonging to the class of thiol-proteases. Two other allergens of 24 and 28 kd appear identical on amino acid sequencing.

Allergens↗
PubMed1997

Cytometric analysis of immunosenescence.

We have been studying the immune system of healthy centenarians for many years, and they provide the best example of successful aging. They are people who have escaped major age-related diseases and reached the extreme limit of human life in good clinical condition. In most cases, histories of centenarians reveal them to be free of cancer, dementia, diabetes, cardiovascular diseases, and cataracts. Moreover, in order to reach such an advanced age, they should be equipped with well preserved and efficient immuno- and defense mechanisms, and optimal combinations of an appropriate lifestyle and genetic background. Using this approach, several paradoxes emerged as far as the immune system of centenarians is concerned, regarding: i) humoral immunity (increase in plasma immunoglobulins and nonorgan-specific autoantibodies, decrease in B cell number and lack of organ-specific autoantibodies); ii) cellular immunity (well preserved number of "virgin" T cells, a relatively intact T cell repertoire despite a thymus involuting since puberty, increased number of cells with markers of NK activity); iii) decreased peripheral blood lymphocyte tendency to programmed cell death, associated with a well preserved mitochondria functionality and intracellular bcl-2 levels. An age-related increase in the levels of adhesion molecule present on lymphocyte plasma-membrane, accompanied by a complex reshaping of the cytokine network, must be added to this scenario. All our data fit the hypothesis that a complex, unpredicted remodeling of the immune system occurs with age. In the present review it is underlined how flow cytometry has been used to study most of the above mentioned aspects of immunosenescence, and to establish new age-related reference values.

Adult↗
PubMed1996

CD45 isoforms expression on CD4+ and CD8+ T cells throughout life, from newborns to centenarians: implications for T cell memory.

CD4+ and CD8+ peripheral blood T lymphocytes show mutually exclusive expression of CD45RA or CD45R0, two isoforms of the common leukocyte antigen that seem to recognize so-called virgin/unprimed and memory/activated T cells. The expression of these isoforms has been studied by three colour cytofluorimetric analysis on CD4+ or CD8+ peripheral blood CD3+ cells from 22 healthy centenarians, analyzed in a context of 202 healthy donors 0-110 years old. An age-related unbalance of virgin and memory cells was found between CD4+ and CD8+ subsets. As expected, at birgh 95-99% of the CD3+ lymphocytes expressed the CD45RA isoform. A rapid increase of CD45R0+ cells was observed in the first 2-3 decades of life, this phenomenon being much more pronounced on CD4+ cells. Subsequently, the increase of the 'memory' compartment was much less rapid, so that in centenarians a consistent reservoire of CD45RA+ among CD4+ cells was still present (about 20%). In these exceptional individuals the percentage of CD45RA+ cells among CD8+ T lymphocytes was even higher (about 50%), and only slightly lower than that of young donors (about 55-60%). Thus, the main changes occurred at a different rate in CD4+ (about 20%). In these exceptional individuals the percentage of CD45RA+ cells among CD8+ T lymphocytes was even higher (about 50%), and only slightly lower than that of young donors (about 55-60%). Thus, the main changes occurred at a different rate in CD4+ and in CD8+ T cells, at an age of between 0 and 30 years, when the thymus is still functionally active. Interestingly, no difference in the usage of CD45 isoforms was observed within T cells bearing four different V beta-T cell receptor (TCR). The significance of this age-related unbalance is unknown. However, the presence of a great number of CD45RA+ T lymphocytes within the CD4+ and the CD8+ T cell subsets even in the peripheral blood of centenarians poses the problem of their origin (thymus? extrathymic sites?), of their functional role and of their lifespan. Moreover, the data on centenarians suggest that they may represent a very selected population where a slowing of immunosenescence occurs.

Adolescent↗
PubMed1996

Identification of the allergenic components of kiwi fruit and evaluation of their cross-reactivity with timothy and birch pollens.

BACKGROUND: Only a few food allergens have as yet been identified, mainly because of the difficulty of obtaining a sufficient number of patients who are clinically sensitized to a given food. This is more feasible in the case of the oral allergy syndrome (OAS), a common form of food allergy, which is especially prevalent in patients with pollinosis. OBJECTIVE: We designed a study to identify the allergens of kiwi fruit (Actinidia chinensis) by analyzing the sera of patients with OAS for kiwi and to examine the cross-reactivity of these allergens with timothy and birch pollen allergens. METHODS: Twenty-seven patients with OAS for kiwi, a positive skin prick test response and serum IgE antibody to kiwi, and a positive open kiwi challenge test result and three patients who had OAS with severe systemic symptoms, which excluded a challenge test, were included in this study. The different polypeptide components of an extract of fresh kiwi were separated by sodium dodecylsulfate-polyacrylamide gel electrophoresis and analyzed by IgE immunoblotting with sera from these patients. Cross-reactivity with the two pollen extracts was assessed by inhibition of the immunoblots with pooled and individual patients' sera. RESULTS: Twelve IgE-binding components with molecular weights ranging from 12 to 64 kd were identified in the kiwi extract, but only a 30 kd component acted as major allergen, being recognized by sera of 100% of these patients. Inhibition of kiwi immunoblots with timothy and birch pollen extracts demonstrated strong cross-reactivity with some of the kiwi allergens, suggesting complete identity between certain food and pollen allergens; whereas others, particularly the 30 kd allergen, were only partially inhibited, suggesting much weaker cross-reactivity. CONCLUSIONS: Kiwi fruit contains a large number of allergens widely cross-reacting with allergens in grass and birch pollen extracts. Nevertheless, the major allergen at 30 kd appears to be specific for kiwi.

Allergens↗
PubMed1995

Studies on the relationship between the level of specific IgE antibodies and the clinical expression of allergy: I. Definition of levels distinguishing patients with symptomatic from patients with asymptomatic allergy to common aeroallergens.

BACKGROUND: The detection of specific IgE antibodies to environmental allergens does not always coincide with a diagnosis of clinically evident allergic disease, because some patients with positive skin and/or in vitro test results have no symptoms related to the allergen or allergens that induced the antibodies. OBJECTIVE: In a multicenter study the optimal cutoff values for specific IgE antibody levels and skin test results that could discriminate between patients with symptomatic and those with asymptomatic allergy were determined. METHODS: IgE antibodies specific for a panel of common aeroallergens were assayed with the Pharmacia CAP System (Pharmacia, Uppsala, Sweden) in two groups of patients, a group of 267 patients with symptomatic allergy and a group of 232 with asymptomatic allergy--both with positive skin prick test results--and in a group of 243 healthy, nonallergic control subjects. The cutoff values were established by receiver operating characteristic analysis. RESULTS: A significantly higher mean specific IgE antibody value was found in patients with symptomatic allergy compared with patients with asymptomatic allergy (p < 0.001) and in patients with symptomatic allergy compared with healthy control subjects (p < 0.001). The optimal CAP System cutoff value between patients with symptomatic and those with asymptomatic allergy was 11.7 kU/L, and when seasonal allergens were compared with perennial allergens, the cutoffs were 10.7 kU/L and 8.4 kU/L, respectively. The optimal cutoff value for the skin prick test was a wheel area of 32 mm2 for seasonal allergens and 31 mm2 for perennial allergens. The skin test had a lower diagnostic value (sum of sensitivity and specificity) than the CAP System. CONCLUSIONS: Cutoff values for specific serum IgE antibody levels are likely to be useful in clinical practice to distinguish symptomatic from asymptomatic allergy in patients with positive skin test results.

Adolescent↗
PubMed1995

Massive activation of immune cells with an intact T cell repertoire in acute human immunodeficiency virus syndrome.

In 8 patients with symptomatic, acute primary infection with human immunodeficiency virus (HIV), a dramatic and persistent decrease in CD4+ lymphocytes was seen, accompanied by a marked increase in activated/memory CD8+ T cells (CD38+, CD45R0+, HLA-DR+, with high amounts of cell adhesion molecules), which represented most circulating lymphocytes, but no gross alterations in V beta T cell repertoire. Extremely high plasma levels of proinflammatory cytokines were observed. Three patients were followed for 2-3 years: The number of CD4+ cells, extremely low at first, increased significantly in a few months but decreased rapidly after a short stable period. Cytotoxic T lymphocytes bearing markers of immunologic activation/memory could play an important role in the earliest phases of the disease. It remains to be established how such a dramatic onset could determine the rapid progression of the infection that seems characteristic of patients with acute HIV syndrome.

Acquired Immunodeficiency Syndrome↗