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Biomedical subjects

M Miraglia

Publications and source records attributed to M Miraglia.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of allergenicity of genetically modified soybean protein extract in a murine model of oral allergen-specific sensitization.

BACKGROUND: With the development of genetically modified crop plants there has been a growing interest in the approaches available to assess the potential allergenicity of novel gene products. For additional assessment of the potential allergenicity of expressed proteins, informative data can be generated using animal models. Soybean is one of the major source of protein in human and animal nutrition, and has also been well characterized as a major allergenic source. Advances in biotechnology have resulted in an increasing number of genetically engineered foods, and among these soybean is one of the most widespread. OBJECTIVE: To develop and characterize a murine model of IgE-mediated soybean sensitization induced by intragastric immunization, in the presence of Cholera Toxin, with wild-type soybean extract (wt-SE) or with genetically modified soybean extract (gm-SE). METHODS: Balb/c mice born in our animal facilities, from females fed on soy-free food, were fed with the same soy-free food and used in all the experiments. Mice were sensitized by gavages with soybean extracts, and allergen-specific IgE and IgG responses were studied by direct ELISA and ELISA inhibition. Antigen-specific cell proliferation and cytokine production were evaluated in spleen cell cultures. Results Sensitization with both soybean extracts induced high levels of antigen-specific IgE and IgG1 and low levels of specific IgG2a. Both wt-SE and gm-SE were able to inhibit the binding of specific IgE from mice immunized with gm-SE to the same antigen used for the ELISA coating. A comparable proliferative response was obtained with the homologous as well as with the heterologous extracts. CONCLUSION: In sensitized mice, we observed a predominantly T-helper type 2 (Th2)-type immune response, with increased soybean-specific IgE and IgG1 antibodies and a concomitant increase of IL-4 and IL-5 production. RESULTS: obtained by specific IgE ELISA inhibition and by antigen-specific T cell proliferation demonstrated that wt-SE and gm-SE shared B and T epitopes. The present murine model of soybean sensitization established by the oral route should provide valuable information about risk assessment for food allergy from new proteins of genetically modified foods.

Administration, Oral↗
PubMed2005

The role of sampling in mycotoxin contamination: an holistic view.

The need to obtain a representative sample deserves particular consideration since a wrong sampling plan can greatly affect the reliability of the measured levels of mycotoxins. This can even result in legal disputes and barriers to trade. Reported here is an holistic view for an ideal sampling plan, which is based on two consecutive steps: (i) To establish 'why, where and when' sampling has to be performed by assessing the purpose, the appropriate time and the site for collecting the samples; (ii) To establish 'how' to draw samples by assessing practical ad hoc guidelines, considering that, for bulk goods in particular, mycotoxins are not at all homogeneously distributed in a lot. So far, step 1 is not yet covered by specific guidelines while for step 2, European regulations establish the procedures for the sampling of bulk and retail products potentially contaminated by mycotoxins.

Environmental Monitoring↗
PubMed2004

Detection and traceability of genetically modified organisms in the food production chain.

Both labelling and traceability of genetically modified organisms are current issues that are considered in trade and regulation. Currently, labelling of genetically modified foods containing detectable transgenic material is required by EU legislation. A proposed package of legislation would extend this labelling to foods without any traces of transgenics. These new legislations would also impose labelling and a traceability system based on documentation throughout the food and feed manufacture system. The regulatory issues of risk analysis and labelling are currently harmonised by Codex Alimentarius. The implementation and maintenance of the regulations necessitates sampling protocols and analytical methodologies that allow for accurate determination of the content of genetically modified organisms within a food and feed sample. Current methodologies for the analysis of genetically modified organisms are focused on either one of two targets, the transgenic DNA inserted- or the novel protein(s) expressed- in a genetically modified product. For most DNA-based detection methods, the polymerase chain reaction is employed. Items that need consideration in the use of DNA-based detection methods include the specificity, sensitivity, matrix effects, internal reference DNA, availability of external reference materials, hemizygosity versus homozygosity, extrachromosomal DNA, and international harmonisation. For most protein-based methods, enzyme-linked immunosorbent assays with antibodies binding the novel protein are employed. Consideration should be given to the selection of the antigen bound by the antibody, accuracy, validation, and matrix effects. Currently, validation of detection methods for analysis of genetically modified organisms is taking place. In addition, new methodologies are developed, including the use of microarrays, mass spectrometry, and surface plasmon resonance. Challenges for GMO detection include the detection of transgenic material in materials with varying chromosome numbers. The existing and proposed regulatory EU requirements for traceability of genetically modified products fit within a broader tendency towards traceability of foods in general and, commercially, towards products that can be distinguished from each other. Traceability systems document the history of a product and may serve the purpose of both marketing and health protection. In this framework, segregation and identity preservation systems allow for the separation of genetically modified and non-modified products from "farm to fork". Implementation of these systems comes with specific technical requirements for each particular step of the food processing chain. In addition, the feasibility of traceability systems depends on a number of factors, including unique identifiers for each genetically modified product, detection methods, permissible levels of contamination, and financial costs. In conclusion, progress has been achieved in the field of sampling, detection, and traceability of genetically modified products, while some issues remain to be solved. For success, much will depend on the threshold level for adventitious contamination set by legislation.

Animals↗
PubMed1999

Serum levels of ochratoxin A in healthy adults in Tuscany: correlation with individual characteristics and between repeat measurements.

Ochratoxin A (OTA), a mycotoxin widely contaminating staple foods and beverages, has been classified as a "possible human carcinogen (Group 2B)" by the IARC. Serum levels of OTA were measured in a group of 138 healthy adults (age, 35-65 years) living in the area surrounding Florence (Tuscany, central Italy) and detected in all but four samples (97%). After the exclusion of one subject with a peak value of 57.2 ng/ml, OTA levels ranged between 0.12 and 2.84 ng/ml, with mean and median values of 0.56 and 0.48 ng/ml, respectively. OTA levels were significantly higher in men than in women (0.64 versus 0.50) and correlated positively with height. A strong association was found with the season in which blood samples were obtained, with summer values higher than autumn values. On the other hand, OTA levels tended to be negatively associated with blood pressure, either systolic or diastolic; no association was evident with age, weight, body mass index, and smoking history. The associations with height and season persisted in a multivariate regression analysis. A subgroup of subjects provided a repeat blood sample approximately 1 year later. The Spearman correlation coefficient between 68 pairs of original and repeat measurements was practically null (r = 0.05). Only two subjects (2.9%) had OTA levels of >1 ng/ml on both occasions. These results suggest that OTA contamination is widespread in foods consumed by this population, in agreement with previous reports from Italy and other countries. A strong seasonal variation, which possibly differs from year to year, was observed. OTA serum levels are a short-term biomarker with a high within-subject variability; therefore they have limited use at the individual level but can be used to characterize populations or subgroups of subjects. Additional analyses are needed to explore the dietary determinants of OTA levels in this population.

Adult↗
PubMed1996

Quality Assurance in Mycotoxin Analysis

Mycotoxin analysis in food and biological fluids is receiving more and more concern, in view also of increasing involvement by the European Union regarding legislation. Basically all the analytical steps regarding mycotoxin analysis have to be performed according to accurate criteria which are strictly connected to the quality of results in terms of reliability. The only rationale for reducing this difficulty is to apply quality assurance principles. Quality assurance principles define, in fact, the rules to be observed for performing this analysis with a degree of uncertainty that is as low as may be possible. In particular sampling techniques, if carried out improperly, give rise to uncertainty concerning the representativeness of samples that is so critical as to induce a dramatic source of errors in the final analysis. Therefore it seems appropriate to plan training courses for personnel on the various side-effects related to the available sampling and subsampling techniques depending on the commodity. Other contributions to the overall error derive from improper methodologies used by technicians in the pre-treatment step of the samples (incorrect use of glassware, standard solutions, etc.), and finally from the operations involved in the whole analytical procedure. In addition, the use of reference materials and certified reference materials together with the utilization of validated methods of analysis will be dealt with as concrete procedures for obtaining the certainty of final results of good quality. This aspect takes on a relevant outcome if applied to official control activities from authorized bodies acting at a national level.

Journal Article↗
PubMed1996

Application of Biomarkers to Assessment of Risk to Human Health from Exposure to Mycotoxins

Mycotoxins, the toxic compounds produced by mold secondary metabolism, represent a relevant source of danger to humans through alimentary channels. Efforts have been made by researchers and by national authorities to assess mycotoxin incidence in food, but often results are to be considered approximate or inaccurate due to the huge difficulties posed by sampling procedures. More recently the evaluation of mycotoxins in biological fluids have been given increasing attention since the results may offer valuable indications, although general on the overall status of mycotoxin contamination in food and feed. The assessment of the degree of exposure to these contaminants in the population or in specific groups can also be pursued. Researches on mycotoxins in biological fluids greatly contribute to clarify the mechanism of health impairment attributable to these toxic compounds and to elucidate the dose-response relationship. Despite the considerable efforts devoted to mycotoxin research in the past few decades, improvements in methodology has to be achieved mainly in sampling procedures and in quality assurance of the laboratories involved in mycotoxin analysis, as well as in the selection of appropriate biomarkers.

Journal Article↗
PubMed1995

Ochratoxin A levels in human milk and related food samples: an exposure assessment.

Ochratoxin A (OA) is a mycotoxin detected in a variety of food and feeds mostly from countries with temperate or continental climate, because the fungi that produce it, mainly Aspergillus ochraceus, Penicillium verrucosum, and Penicillium viridicatum, can grow under a great variety of climate conditions. The aim of this article was, firstly, to confirm the occurrence of OA in human milk in Italy. Then, a preliminary calculation of OA intake via human milk was made, from ingested food. For this investigation, food and milk samples were collected, continuously for a week, from 4 lactating mothers. The obtained results revealed a significant exposure of sucklings and mothers to OA levels higher than the tolerable daily intake as estimated from animal models. On the basis of these data, a major effort in planning surveillance and research programs to control OA contamination in food, feed, and biological fluids should be pursued.

Beer↗
PubMed1991

Contamination of human milk with ochratoxin A.

Ochratoxin A is a mycotoxin frequently found as a contaminant both in food and in animal feed. It can reach humans through the food chain and can then be excreted in biological fluids, one of which is human milk; it can therefore be transmitted from mother to child during breast-feeding. This fact prompted us to carry out the present study, aimed at the determination of ochratoxin A in human milk in Italy, as done elsewhere. Fifty samples of human milk were collected randomly over one year and analysed by a high-performance liquid chromatography method. Nine samples were found to contain levels in the range of 1.7-6.6 ng/ml.

Chromatography, High Pressure Liquid↗
PubMed1987

Long-term administration of low doses of mycotoxins in poultry. 1. Residues of ochratoxin A in broilers and laying hens.

The occurrence and amount of residues of ochratoxin A (OA) in poultry tissues and organs were investigated in a trial aimed at measuring the effects of contamination approaching the patterns more frequently found in natural situations (i.e., small doses of OA in the diet for long periods). Hubbard male broilers and laying hens were treated with an OA-contaminated feed (50 ppb) from the 14th day of age onward. Both groups were further divided into subgroups, some of which underwent continual treatment (64 and 169 days, respectively) and others that were withdrawn from administration (maximum 28 and 82 days, respectively). Determination of residues was performed by high performance liquid chromatography. Residues in liver were higher in broilers (up to 11.0 ppb) than in hens (1.5 ppb), whereas the reverse occurred in kidney (up to .8 and 5.8 ppb, respectively). Residues (.8 ppb) were also in hen thigh muscle but not in breast muscle. Residues of OA in poultry appear to be of possible public health concern. Suggestions for monitoring are given.

Animals↗
PubMed1987

Distribution of ceftriaxone in the tissues of the female genital system.

Twenty-nine patients, hospitalized in order to undergo gynaecological surgery involving organ removal, were treated with a single intramuscular administration of 1 g ceftriaxone before surgery. The tissue levels of the drug determined in the organs considered: uterus, ovary, fallopian tubes, vagina, proved to be comparable and to guarantee its satisfactory and uniform penetration into the tissues of the female genital system at a slowly decreasing rate. The high levels observed 12 h and 24 h after administration (2.24 +/- 0.74 mcg/g; 3.58 +/- 0.60 mcg/g; 0.70 +/- 0.45 mcg/g; 1.20 +/- 0.57 mcg/g in the ovaries and myometrium respectively) suggest a possible application of ceftriaxone in presurgical prophylaxis also in cases of female genital surgery.

Adolescent↗
PubMed1983

Circulating levels of testosterone, 17 beta-oestradiol, luteinising hormone and prolactin in postmenopausal breast cancer patients.

Serum testosterone, 17 beta-oestradiol, luteinising hormone (LH) and prolactin were measured in 28 postmenopausal breast cancer patients after mastectomy and in 30 postmenopausal normal controls. In the patient group, mean levels of oestradiol, LH and prolactin did not differ significantly from those of the control group. Mean testosterone levels were higher in breast cancer patients than in normal controls, either considering the overall groups (P less than 0.001) or dividing them into subgroups according to years since menopause. Breast cancer patients were divided into 2 subgroups according to time since mastectomy: 19 patients had been examined within a year of mastectomy and 9 patients some years after mastectomy. Testosterone, but not oestradiol, LH or prolactin values in each subgroup were still significantly higher (P less than 0.001 and P less than 0.02, respectively) than in normal controls. Years since menopause were significantly correlated with testosterone (r = 0.533, P less than 0.01) but not with the other hormones in the cancer group. These results confirm our previous findings of increased urinary testosterone values in postmenopausal breast cancer patients and support the hypothesis that androgens may play a role in the development of breast cancer.

Aged↗
PubMed1983

Increased urinary androgen levels in patients with carcinoma in situ of the breast with onset while taking oral contraceptives.

Urinary testosterone, androstanediol, ethiocolanolone, and androsterone glucuronide were determined by use of gas chromatography in four patients with carcinoma in situ of the breast. In all the patients, one or more of these hormones were higher than normal. This finding supports previous reports from our laboratory of increased androgen excretion in patients with fibrocystic disease or infiltrating carcinoma of the breast. Carcinoma in situ arose while the four patients were taking oral contraceptives. The progestational component of the pill, a nonderivative of testosterone, may carry with it some androgenic properties. This fact and the discovery of increased androgen excretion levels in these four patients led us to suppose that androgens could play a role in the development of breast cancer.

Adolescent↗
PubMedDate not supplied

HPLC determination of the total content of aflatoxins in naturally contaminated eggs in free and conjugate forms.

A study was undertaken to evaluate the total aflatoxin content in naturally contaminated eggs. Two pools of eggs from laying hens were collected after 2 and 7 days of treatment with aflatoxin B1 (AFB1). An HPLC method has been developed for the determination of AFB1, aflatoxin M1 (AFM1), aflatoxin B2a (AFB2a) and aflatoxicol (Ro) both in free form and after release from water-soluble conjugates. The bound form was cleaned up after acid hydrolysis of the aqueous phase. Eggs collected after 2 days of treatment revealed residues of AFB1, AFB2a and Ro in the organic phase, but none in the aqueous portion. After 7 days of treatment both AFB1 and its hydroxy derivative were found in the organic phase but the aqueous portion showed only hydroxylated metabolites accounting for 35% of the total aflatoxin content.

Aflatoxins↗