The prevalence of food allergy: a meta-analysis

BACKGROUND: There is uncertainty about the prevalence of food allergy in communities. OBJECTIVE: To assess the prevalence of food allergy by performing a meta-analysis according to the method of assessment used. METHODS: The foods assessed were cow's milk, hen's egg, peanut, fish, shellfish, and an overall estimate of food allergy. We summarized the information in 5 categories: self-reported symptoms, specific IgE positive, specific skin prick test positive, symptoms combined with sensitization, and food challenge studies. We systematically searched MEDLINE and EMBASE for publications since 1990. The meta-analysis included only original studies. They were stratified by age groups: infant/preschool, school children, and adults. RESULTS: A total of 934 articles were identified, but only 51 were considered appropriate for inclusion. The prevalence of self-reported food allergy was very high compared with objective measures. There was marked heterogeneity between studies regardless of type of assessment or food item considered, and in most analyses this persisted after age stratification. Self-reported prevalence of food allergy varied from 1.2% to 17% for milk, 0.2% to 7% for egg, 0% to 2% for peanuts and fish, 0% to 10% for shellfish, and 3% to 35% for any food. CONCLUSION: There is a marked heterogeneity in the prevalence of food allergy that could be a result of differences in study design or methodology, or differences between populations. CLINICAL IMPLICATIONS: We recommend that measurements be made by using standardized methods, if possible food challenge. We need to be cautious in estimates of prevalence based only on self-reported food allergy.     

Hepatic-Intestinal Disposal of Endogenous Human Alpha Atrial Natriuretic Factor99-126 in Patients with Cirrhosis

Hepatic-intestinal disposal of endogenous human alpha atrial natriuretic factor99-126 (ANF) was assessed in 13 patients with cirrhosis (six Child-Turcotte class A, five class B, and two class C) and eight control subjects. The Fick principle was applied during hepatic vein catheterization. Arterial ANF concentration in patients with cirrhosis [11.1 +/- 1.6 (SEM) pmol/L] was not significantly different from that of the control subjects (14.9 +/- 4.2 pmol/L, NS). Arteriohepatic venous extraction ratio of ANF (0.43 +/- 0.05 in cirrhosis vs 0.37 +/- 0.09 in controls, NS), hepatic-intestinal clearance (274 +/- 46 vs 237 +/- 46 ml/min, NS) and removal rate (2.9 +/- 0.88 vs 3.1 +/- 0.77 pmol/min, NS) were closely similar in patients and controls. The present results give no indication that significantly reduced hepatic-intestinal disposal of ANF has a role in causing altered circulating plasma levels of this peptide in cirrhosis. This is in keeping with the presence of vascular clearance receptors and peptidases for ANF degradation independent of hepatocellular function.     

Malaria PCR Detection in Cambodian Low-Transmission Settings: Dried Blood Spots versus Venous Blood Samples

In the context of malaria elimination, novel strategies for detecting very low malaria parasite densities in asymptomatic individuals are needed. One of the major limitations of the malaria parasite detection methods is the volume of blood samples being analyzed. The objective of the study was to compare the diagnostic accuracy of a malaria polymerase chain reaction assay, from dried blood spots (DBS, 5 μL) and different volumes of venous blood (50 μL, 200 μL, and 1 mL). The limit of detection of the polymerase chain reaction assay, using calibrated Plasmodium falciparum blood dilutions, showed that venous blood samples (50 μL, 200 μL, 1 mL) combined with Qiagen extraction methods gave a similar threshold of 100 parasites/mL, ∼100-fold lower than 5 μL DBS/Instagene method. On a set of 521 field samples, collected in two different transmission areas in northern Cambodia, no significant difference in the proportion of parasite carriers, regardless of the methods used was found. The 5 μL DBS method missed 27% of the samples detected by the 1 mL venous blood method, but most of the missed parasites carriers were infected by Plasmodium vivax (84%). The remaining missed P. falciparum parasite carriers (N = 3) were only detected in high-transmission areas.     

Effect of Pentagastrin, secretin, and cholecystokinin on gastric secretion of pepsin in man

In eight volunteers the effect of pentagastrin (0.15, 1.0 and 6.0 microgram/kg body weight/h), secretin (0.5 and 1.0 clinical units/kg b.w./h), and cholecystokinin (CCK) (0.5 and 1.0 Ivy dog units/kg b.w./h) on the gastric secretion of pepsin was investigated to ascertain whether interaction occurred. A high intraindividual variation was found, and also a significant washout of pepsin in the initial period after stimulation. Pepsin secretion was stimulated after pentagastrin (50% above basal level) and even more after secretin (75%-200% above basal level), whereas no stimulation but a tendency for depression was seen after CCK. With the doses of gastrointestinal hormones used in this investigation, no interaction between secretin and CCK on gastric secretion of pepsin in man was demonstrated.     

Eicosanoids in acute and chronic psoriatic lesions: leukotriene B4, but not 12-hydroxy-eicosatetraenoic acid, is present in biologically active amounts in acute guttate lesions

The biochemical changes underlying the clinical manifestations of psoriasis are unknown. Certain chemotactic eicosanoids derived from arachidonic acid metabolism have been suggested to play important roles in psoriasis, because of their presence in lesional psoriatic skin and their ability to elicit skin inflammation and to stimulate epidermal proliferation. The purpose of the present study was to elucidate which eicosanoids might be involved in the early phases of the inflammatory processes of psoriasis. Eicosanoids were analyzed in scale and in lesional skin without scale both in acute guttate and chronic plaque psoriatic lesions. Methods for identification of eicosanoids included reversed-phase high-performance liquid chromatography combined with radioimmunoassay. Leukotriene B4 was present in both acute guttate and chronic plaque skin lesions in biologically active amounts (acute guttate lesions: 18.7 +/- 7.1 ng/g wet tissue in scale and 3.2 +/- 1.5 ng/g wet tissue in lesional skin without scale; chronic plaque lesions: 33.1 +/- 9.7 ng/g wet tissue in scale and 5.3 +/- 2.0 ng/g wet tissue in lesional skin without scale). 12- and 15-hydroxy-eicosatetraenoic acid (HETE) reached biologically active concentrations only in scale of chronic plaque lesions (1,512 +/- 282 and 1,441 +/- 411 ng/g wet tissue, respectively). The level of prostaglandin E2 in chronic plaque lesions was similar to the level in normal skin, while the level in acute guttate lesions was increased twofold (71.0 +/- 14.8 ng/g wet tissue). These results demonstrate that leukotriene B4, but not 12-HETE, is present in acute guttate psoriatic skin lesions in concentrations able to exert biologic effects. Leukotriene B4 may therefore participate in inflammatory changes of acute psoriasis.     

Quantitation of Passive Cutaneous Anaphylaxis (PGA) by Using Radiolabelled Antigen

The major problem of detecting reaginic antibody by passive cutaneous anaphylaxis IPCA) is the quantitation of the dye reaction. Radiolabelled antigen was used in an attempt to quantitate the PCA reaction (Radio-PCA). Antisera containing reaginic antibody against human serum albumin (HSA) were produced in rabbits. These antisera were injected into normal rabbit skin in different dilutions. Twenty-four hours later BSA was injected intravenously either with Evans Blue or as 125-1-HSA. Radioactivity found in antibody-containing skin was significantly higher than in control specimens containing saline or normal rabbit serum, as low as antiserum dilutions of 1:1,000. Compared with the Evans Blue technique Radio-PCA was able to distinguish quantitatively between different antiserum dilutions at a higher level of statistical significance.     

Acute, subacute toxicity and genotoxic effect of Bio-Quinone Q10 in mice and rats

In the present study, the acute, subacute and genetic toxicity of Coenzyme Q10 (CoQ10) in the form of Bio-Quinone (Pharma Nord, Denmark) was assessed. LD(50) of CoQ10 by oral treatment was greater than 20g/kg body weight in both female and male mice. Genotoxicity was assessed in mice by Ames test in Salmonella typhimurium strains TA97, TA98, TA100 and TA102, by bone marrow micronucleus test and sperm abnormality. Thirty-day subacute toxicity was conducted with oral daily dose at 0, 0.56, 1.13 and 2.25g/kg body weight in rats. No significant changes in body weight, food intake, behavior, mortality, hematology, blood biochemistry, vital organ weight, sperm abnormality, mutagenicity and micronucleus formation were observed and no clinical signs or adverse effects were detected by administration of CoQ10. These results support the safety of CoQ10 for oral consumption.     

One hundred and twenty-seven cultured human tumor cell lines producing tumors in nude mice.

One hundred and twenty-seven cultured human tumor cell lines produced tumors after sc inoculation of 1-20 million cells into nude mice. They included 56 carcinoma lines, 14 sarcoma lines, and 57 lines from miscellaneous tumors and were all glucose-6-phosphate dehydrogenase type B. Twenty-nine percent of the lines produced tumors of 1 cm3 size within 1 month and 41% in the second month after inoculation. The histopathology correlated with the human tumor of origin in all cases.     

Encouraging early clinical experience with deliberately delayed temporary fetoscopic tracheal occlusion for the prenatal treatment of life-threatening right and left congenital diaphragmatic hernias

OBJECTIVE: In order to assess the effect of deliberately delayed percutaneous fetoscopic tracheal occlusion on survival of fetuses with life-threatening congenital diaphragmatic hernia. METHODS: Eight fetuses with life-threatening congenital diaphragmatic hernia underwent fetoscopic tracheal balloon occlusion between 29 + 0 and 32 + 4 weeks of gestation. Delayed occlusion was chosen in order to minimize potentially negative pulmonary effects from premature delivery as a result of fetal surgery. In addition, we wanted to become able to provide all available postnatal intensive care treatment means in these patients. RESULTS: Six of the 8 fetuses survived to discharge from hospital. CONCLUSION: Delayed fetoscopic tracheal balloon occlusion may be rewarded with lung growth sufficient to allow survival of fetuses with life-threatening congenital diaphragmatic hernia.