Monitoring peanut allergen in food products by measuring Ara h 1

BACKGROUND: Peanut allergy is an important health problem in the United States, affecting approximately 0.6% of children. Inadvertent exposure to peanut is a risk factor for life-threatening food-induced anaphylaxis. OBJECTIVE: The purpose of this investigation was to develop an immunoassay for a major peanut allergen, Ara h 1, to detect peanut allergen in foods so that the risk of inadvertent exposure can be reduced. METHODS: A specific 2-site monoclonal antibody-based ELISA was developed to measure Ara h 1 in foods. The sensitivity of the assay was 30 ng/mL. Ara h 1 was measured in foods (n = 83) with or without peanut and in experiments to optimize allergen yield and to determine peanut contamination in spiked foods. RESULTS: Ara h 1 levels in food products ranged from less than 0.1 microg/g to 500 microg/g. Ara h 1 measured in ng/mL was transformed to microg/g for food products. Peanut butter contained the highest amounts of Ara h 1. Peanut extracts contained from 0.5 to 15 mg Ara h 1/g of peanut depending on the extraction conditions. Optimal extraction of Ara h 1 was obtained by using phosphate buffer with 1 mol/L NaCl and Tween at 60 degrees C. Ara h 1 was not always detected in presence of chocolate under the extraction conditions tested. Spiking experiments showed that the assay could detect approximately 0.1% Ara h 1 contamination of food with ground peanut. There was an excellent correlation between Ara h 1 levels and peanut content measured by using a commercial polyclonal antibody-based ELISA (r = 93, n = 31, P <.001). CONCLUSION: A new sensitive and specific monoclonal antibody-based ELISA was used to monitor Ara h 1 content in food products. This assay should be useful for monitoring peanut contamination in the food manufacturing and processing industry and in developing thresholds for sensitization or allergic reaction in persons with peanut allergy.     

Predictive value of normal sperm morphology: a structured literature review

The aim of the study was to conduct a structured review of theliterature published on the use of normal sperm morphology,as an indicator of male fertility potential in the in-vitrofertilization (IVF) situation, and to establish the universalpredictive value of this semen parameter. Published literaturein which normal sperm morphology was used to predict fertilizationand pregnancy, during the period 1978-1996, was reviewed. Atotal of 216 articles were identified by the sourcing methodology,but only 49 provided data that could be tabulated and analysed.Of these, only 18 provided sufficient data for statistical analysis.Fifteen studies used the strict criteria to evaluate sperm morphology,two used World Health Organization (WHO) guidelines and oneused both the strict criteria and the WHO guidelines. All thestudies (n=10) using the 5 and 14% normal sperm morphology thresholds(strict criteria) produced positive predictive values for IVFsuccess. In the prediction of pregnancy, 82% (9/11) and 75%(6/8) of the studies produced positive predictive values whenusing the 5% and 14% thresholds respectively. Aggregating thedata produced around the 5% normal sperm morphology threshold(strict criteria), the overall fertilization rates were 59.3%(1979/3337; per oocyte) for the 4% group and 77.6% (10345/13327;per oocyte) for the >4% group, and the overall pregnancyrates were 15.2% (60/395; per cycle) and 26.0% (355/1368; percycle) respectively. The no-transfer rates across the 5% thresholdwere 24.0% (86/359; per cycle) in the 4% group compared to 7.4%(80/1088; per cycle) in the >4% group. The inclusion of anaccurately evaluated normal sperm morphology count as an integralpart of the standard semen analysis makes this analysis stillthe most cost-effective means of evaluating the male factor.     

Quantitative pharmacological characterization of beta-receptors and two types of alpha-receptors mediating sympathomimetic smooth muscle response in the human Fallopian tube at various cyclic stages

The dissociation constants for adrenoceptor-antagonist complexes (KB) were determined in vitro in circular and longitudinal smooth musculature from the ampullary and isthmic regions of the human Fallopian tube. High extracellular potassium concentrations were used to eliminate the spontaneous contractile activity. Neuronal and extraneuronal amine uptake mechanisms were blocked. The parallel shift of the log dose-response curves was secured in Arunlakshana-Schild plots. KB for the beta-receptor, mediating sympathomimetic relaxation, were determined during alpha-receptor blockade: the values for propranolol were the same (approximately 10(-6) M) in all preparations and at all cyclic stages, as determined from plasma estradiol and progesterone levels. KB for the complex between the alpha-receptor (mediating contraction) and phentolamine were determined during beta-receptor blockade. The values were the same in all types of smooth musculature, but varied with cyclic stage: they were around 7 x 10(-8) M when plasma estradiol and progesterone were both minimum, and around 2 x 10(-7) M when these steroid levels were moderate to high, suggesting that the properties of the contractile receptors of the human Fallopian tube are modified during the menstrual cycle.     

Differential expression of cdk inhibitors p16, p21cip1, p27kip1, and cyclin E in cervical cytological smears prepared by the ThinPrep method

Our objective was to correlate p16, p21cip1, p27kip1, and cyclin E protein expression with the degree of dysplasia on ThinPrep Papanicolaou (Pap) smears using a modified immunoperoxidase staining. Smears read as normal, atypical squamous cells of undetermined significance (ASC-US), low-grade squamous intraepithelial lesion (LSIL), or high-grade SIL (HSIL) were identified and tested for high-risk human papillomavirus (HR-HPV). Additional smears were processed for immunoperoxidase for p16, p21cip1, p27kip1, and cyclin E. Thirty-four smears were satisfactory for study. The p16 was positive in all nine HSIL, in four of nine LSIL, and in one of seven ASC-US. The p27kip1 was positive in all nine HSIL, in eight of nine LSIL, and in one of seven ASC-US. The p21cip1 was positive in all nine HSIL, in one of nine LSIL, and in one of seven ASC-US. Cyclin E was positive in seven of nine HSIL and in one of nine LSIL and in none of the ASC-US smears. Normal smears were negative for all the antigens. There was poor correlation of protein expression and HR-HPV infection. We concluded that p16, p21cip1, p27kip1, and cyclin E can be demonstrated on Pap smears and they are expressed differentially in dysplastic cells, with highest expression in HSIL. The p21cip1 and cyclin E showed the greatest correlation with HSIL.     

Comparison of the receptors for IgE of various rat basophilic leukaemia cell lines. I. Receptors isolated by IgE-sepharose and IgE and anti-IgE

REceptors for IgE of rat basophilic leukaemia (RBL) cells, maintained in different laboratories were isolated by means of IgE-Sepharose or IgE and anti-IgE, and characterized by SDS-polyacrylamide gel electrophoresis. All cell lines were found to be associated with a receptor molecule (R) which could be isolated either with IgE-Sepharose or IgE and anti-IgE and a second receptor (H) which could only be isolated with the aid of IgE-Sepharose. The relative amounts of these two molecules, as isolated from surface iodinated cells, varied from the RBL cell line to the other and their apparent molecular weights were not identical on all cell lines. Since comparisons were made on the same gel using receptors isolated from cells labelled with different isotopes of iodine, differences in molecular weight must be considered as being intrinsic and not due to methodological variations. These results provide an explanation why differences were observed among receptors for IgE as characterized in various laboratories. In spite of the fact that the various RBL cell lines originated from the same chemically-induced tumour they have, over the years, undergone changes which are reflected in the receptors for IgE.