Gastro-duodenal digestion products of the major peanut allergen Ara h 1 retain an allergenic potential

BACKGROUND: The process of gastro-duodenal digestion may play a role in determining the allergenic properties of food proteins. The sensitizing and allergenic potential of digestion products of highly degraded allergens, such as the major peanut allergen Ara h 1, is currently under debate. We evaluated the effect of in vitro gastro-duodenal digestion of Ara h 1 on T cell reactivity and basophil histamine release. METHODS: An in vitro model of gastro-duodenal digestion was used to investigate changes in the allergenic properties of Ara h 1 using in vitro assays monitoring T cell reactivity (proliferation, cytokine production) and histamine release of basophils from peanut allergic individuals. The digestion process was monitored using an SDS-PAGE gel. RESULTS: In vitro gastric digestion led to rapid degradation of Ara h 1 into small fragments M(r) L5600. Gastric digestion did not affect the ability of Ara h 1 to stimulate cellular proliferation. Gastro-duodenal digestion significantly reduced its ability to stimulate clonal expansion (P<0,05; Wilxocon's signed rank test). The Th-2 type cytokine polarization of T cells from peanut allergic donors (IFN-gamma/IL-13 ratio and IFN-gamma/IL-4 ratio of CFSE(low) CD4(+) T cells) remained unchanged regardless of the level of digestion. Histamine release of basophils from peanut allergic individuals was induced to the same extent by native Ara h 1 and its digestion products. CONCLUSION: Gastro-duodenal digestion fragments of Ara h 1 retain T cell stimulatory and IgE-binding and cross-linking properties of the intact protein.     

The effects of X monosomy on brain development: Monozygotic twins discorcant for Turner's syndrome

Monosomy for the X chromosome is the most frequent cause of Turner's syndrome, a common clinical syndrome associated with particular physical and neurobehavioral features. The results from comprehensive assessment of prepubertal monozygotic female twins discordant for X monosomy are presented. Zygosity was established with DNA Fingerprinting and no evidence of chromosomal mosaicism was seen in either child. Physical features in the affected twin were relatively mild with respect to the full spectrum of physical malformations and disabilities associated with Turner's syndrome. The neurobehavioral phenotypes of the twins were compared. Although both sisters scored in the superior range of intelligence, the affected twin's Performance IQ was 18 points less than her sister, whereas Verbal IQ showed only a 3-point difference between the sisters. Other relative differences were noted within the executive, visuospatial, and visuomotor domains of function. Behavioral evaluation indicated greater problems with attention, hyperactivity, and anxiety in the affected twin. Quantitative analysis of brain anatomy revealed evidence of both general and regional effects of X monosomy on neurodevelopment. Cerebrospinal fluid volume was increased by 25% in the affected twin compared with her sister with a corresponding decrease in gray matter volume. The right frontal, right parietal–occipital, and left parietal-perisylvian regions showed the greatest discrepancy between the sisters with respect to increased cerebrospinal fluid and decreased gray matter volumes in the twin with X monosomy. Differences in the posterior fossa were also noted with a 50% relative increase in the volumes of the fourth ventricle and cisterna magna and a 10 to 15% relative reduction in size of the cerebellar vermis, pons, and medulla in the affected twin. The association between the neurobehavioral and neuroanatomical findings in the affected twin is discussed. The unique nature of the naturally occurring genetic phenomenon seen in this twin pair provides an opportunity to more fully elucidate the neurobehavioral phenotype associated with X monosomy and Turner's syndrome.     

Elevated alpha-fetoprotein and a normal fetal sonogram: association with placental abnormalities

This report documents the outcome of 25 pregnancies with elevated serum alpha-fetoprotein levels on two separate samplings despite normal anatomic appearance of the fetus on a detailed "consultative" sonographic examination. Six of these also had elevated amniotic fluid alpha-fetoprotein. All fetuses in this series were anatomically normal at time of delivery; one aborted fetus was triploid. Of the 25 pregnancies, 16 had sonographically demonstrable placental hemorrhage, eight retroplacental and eight subchorionic. One had hydropic changes in the placenta associated with triploidy. Of the subgroup of six pregnancies in which both serum and amniotic fluid values were elevated, one had a retroplacental hemorrhage, one had a subchorionic hemorrhage, and one had diffuse hydropic changes in the placenta. A control group of 112 patients with normal alpha-fetoprotein levels yielded four with small (less than 2 cm3) subchorionic hemorrhage. The occurrence rate of placental hemorrhage in women with elevated alpha-fetoprotein and normal fetus was 64%, whereas the control group of patients with normal alpha-fetoprotein had a 3.6% occurrence rate of placental hemorrhage. Sonographically detectable placental abnormalities may be associated with elevated alpha-fetoprotein in serum and/or amniotic fluid samples. Such abnormalities may occur because of fetomaternal admixture associated with placental hemorrhage and/or intraamniotic bleeding resulting from subchorionic hemorrhage.     

Zum Problem des Nachweises antithrombocytärer Autoantikörper

Zusammenfassung Blutproben von 161 Patienten (davon 63 Patienten mit einer Thrombocytopenie unter 90000/mm³ und 98 Patienten mit normalen Thrombocytenzahlen) wurden mit dem direkten und/oder indirekten Antiglobulin-Konsumptionstest (AGKT) und dem direkten und/oder indirekten Fluorescenz-Antiglobulintest (FT) under Verwendung von Thrombocyten untersucht. Ohne Berücksichtigung der klinischen Diagnose wurde gefunden, daß thrombocytopenische Patienten in 37% einen positiven dir. AGKT, in 18% einen positiven dir. FT, in 27% einen positiven indir. AGKT und in 28% einen positiven indir. FT aufwiesen. Bei Patienten ohne Thrombocytopenie betrug der Anteil positiver Ergebnisse für den dir. AGKT 30%, für den dir. FT 16%, für den indir. AGKT 7%, für den indir. FT 9%. — Mit Thrombocyten von gesunden Blutspendern waren die Ergebnisse fast ausnahmslos negativ. — Unsere Untersuchungen lassen vermuten, daß der Ausfall der Tests zum Nachweis von antithrombocytären Autoantikörpern stark von nicht-immunologischen Faktoren beeinflußt wird. Beziehungen zu den Plasmaeiweißverhältnissen spielen dabei wahrscheinlich eine wichtige Rolle.

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Summary The blood of 161 patients with different internal diseases was investigated with the direct and/or the indirect antiglobulin consumption test (AGCT) and with the direct and/or indirect fluorescence antiglobulin test (FT) on platelets. 63 patients revealed thrombocytopenia (platelets less than 90000 per mm³) in the course of various diseases, the remainder had normal platelet counts.Irrespective of clinical diagnosis positive results were found in the thrombocytopenic group in 37% with the direct AGCT, in 18% with the direct FT, in 27% with the indirect AGCT and in 28% with the indirect FT. Patients with normal platelet numbers showed positive tests in 30% (direct AGCT), in 16% (direct FT), in 7% (indirect AGCT) and in 9% (indirect FT). Control examinations on thrombocytes of healthy blood donors were almost regularly negative under the same conditions.These results suggest that the tests used for the detection of antiplatelet autoantibodies are severely influenced by non-immunologic factors. There seem to exist correlations between the results of the tests and the level of gammaglobulins in the plasma.

     

Comparison of modified Bordet-Gengou and modified Regan-Lowe media for the isolation of Bordetella pertussis and Bordetella parapertussis.

Culture and fluorescent-antibody methods for detection of Bordetella species were evaluated by two state public health laboratories. Field-inoculated plates of Regan-Lowe agar medium were most useful if incubation was initiated on the day of collection. Regan-Lowe and Bordet-Gengou media were comparable for subculturing nasopharyngeal specimens that were transported and enriched in half-strength Regan-Lowe agar. Maximum sensitivity was achieved when the media were used in parallel. Fluorescent-antibody-stained smears of nasopharyngeal specimens were more sensitive for detection of Bordetella pertussis than for detection of Bordetella parapertussis. The fluorescent-antibody method, however, was too insensitive for use without culture.     

The relative contribution of direct and indirect antigen recognition pathways to the alloresponse and graft rejection depends upon the nature of the transplant

In this study, we measured direct and indirect T-cell alloresponses mediated by CD4(+) and CD8(+) T cells in three mouse transplantation models: skin, cornea, and retina. We show that the contribution of direct and indirect antigen recognition pathways to the alloresponse to fully allogeneic grafts varies depending upon the nature of the tissue/organ transplanted. The implications of this finding for understanding the cellular mechanisms by which rejection is mediated in different transplant models are discussed.     

Effect of treatment protocol and sample time on the frequencies of micronucleated polychromatic erythrocytes in mouse bone marrow and peripheral blood

Studies were conducted to evaluate the effect of experimental protocol on the ability of benzidine (BZD), dimethylbenzanthracene (DMBA) and mitomycin C (MMC), administered by intraperitoneal injection, to induce micronuclei in polychromatic erythrocytes (PCE) of B6C3F1 mice. Three different treatment/sampling protocols were used, involving from one to three consecutive daily treatments and from three to one, respectively, consecutive daily samplings beginning 24 h after the last injection. DMBA and MMC elicited a significant micronucleus response in all three experimental protocols, while BZD induced a significant response only in the multiple injection protocols. Of the three protocols, the 3-day injection/single sample time protocol offers the greatest efficiency in minimizing the number of animals required in a study, in decreasing the time needed for scoring and in simplifying the statistical analysis. In addition, a comparison of the frequency of micronucleated PCE in peripheral blood and bone marrow following the treatment of mice with either BZD or DMBA suggests that, following a three injection protocol, either tissue can be used with equal efficacy.     

Creatine kinase activity associated with the contractile proteins of the guinea-pig carotid artery

Summary Activity and role of creatine kinase associated with contractile proteins of vascular smooth muscle have been investigated using skinned guinea-pig carotid artery rings. Membrane solubilization was performed with the detergent Triton X-100. Creatine kinase activity, isoenzyme profile as well as mechanics were performed on the Triton skinned carotid artery rings. Total creatine kinase activity was 47.3±9.3 IU g¹ ww and electrophoresis showed BB, MB, and MM isoforms (BB-CK being the predominant isoenzyme). One hour incubation with Triton X-100, produced predominantly BB-CK remaining with the myofibrils with some MB, representing 23% of the preskinned creatine activity. When relaxed carotid artery rings were exposed to pCa 9 in the presence of 250 M ADP, 0 ATP, and 12 mM phosphocreatine, tension was not significantly different from resting tension, but changing to pCa 4.5 caused the carotid artery rings to generate 49.5±4.5% of maximal tension. When a high-tension rigor state was achieved (250 M ADP, 0 ATP, 0 phosphocreatine, and pCa 9), the addition of 12 mM phosphocreatine effected significant relaxation. These observations implicate an endogenous form of creatine kinase, associated with the myofilaments, which is capable of producing enough ATP for submaximal tension generation and significant relaxation from rigor conditions. These results suggest co-localization of ATPase, MLCK, and creatine kinase on the contractile proteins of the carotid artery. Such an enzymic association may play a role in the energetic supply to the contractile apparatus of vascular smooth muscle.Recipient of INSERM/NIH Fogarty International Fellowship, TW01585-01.     

The effects of anti-hypertensive therapy on the structural,mechanical and metabolic properties of the rat aorta

The vascular system exhibits altered growth, calcium responses and metabolism during hypertension. To relate such changes, we compared histological, tension and metabolic responses in the aorta from 32-week-old spontaneously hypertensive rats (SHRs), normotensive Wistar–Kyoto (WKY) rats, and SHRs treated with Verapamil (V) and ACE-inhibitor, Trandolapril (T) as well as a combination of the two treatments (C). Vascular hypertrophy was apparent in the SHRs. Contractile responses induced by 50 mmol/l KCl and 2.5 mmol/l Ca²⁺ were significantly lower in the SHR (64.4 mN/mm² vs. 49.2 mN/mm²), but an associated increase in Ca²⁺-sensitivity (EC₅₀ of extracellular Ca²⁺ (mol/l): SHR, 456 vs. WKY, 616) normalised tension generating ability. All treatments led to significant decreases in blood pressure, although only T and C treated animals became normotensive with concomitant normalisation of vascular hypertrophy. An increase in oxygen consumption was apparent in the SHR aorta, which was associated with significant differences in the activities of key metabolic enzymes. Anti-hypertensive treatment normalised many of the metabolic parameters, with the C therapy being the most efficacious. We conclude that the treatment of hypertension by combined therapy leads to a better normalisation of structural, contractile, and metabolic parameters in the SHR, than either treatment alone and that metabolic changes with the pathology are resolved with appropriate therapy.