Skin prick testing and peanut-specific IgE can predict peanut challenge outcomes in preschoolchildren with peanut sensitization.

BACKGROUND: The rise in peanut allergy is a source of considerable burden in the community. A growing number of preschoolchildren have been identified as peanut sensitized in the course of investigation of other allergic conditions. Although many have never knowingly ingested peanuts and their clinical reactivity is not known, it has been common practice to place these children on avoidance diets for many years. OBJECTIVE: To determine the utility of skin prick tests (SPT) and fluorescent-enzyme immunoassays (FEIA) for identifying either peanut allergy or tolerance in preschoolchildren with peanut sensitization. METHODS: Forty-nine preschoolchildren (<5 years of age) with peanut sensitization (SPT ≥ 2 mm or peanut-specific IgE ≥ 0.35 kU/L) but unknown clinical reactivity had graded open peanut challenges reaching a total of 11 g. A positive challenge was defined as an objective IgE-mediated reaction during challenge or the 2-h observation. RESULTS: Forty-nine percent (24/49) of children had positive challenges. An SPT of >7 mm on the day of challenge predicted a positive challenge with a sensitivity of 83% and a negative predictive value (NPV) of 84%. An FEIA of >2.0 kU/L showed a sensitivity of 79% and an NPV of 80%. Predicting challenge outcome from a combination of SPT and FEIA (SPT >7 and/or FEIA >2 is positive) increased sensitivity to 96% and NPV to 95%. CONCLUSION AND CLINICAL RELEVANCE: At least half of preschoolchildren with peanut sensitization and no antecedent history of peanut ingestion can tolerate peanuts. A SPT<7 mm and FEIA<2 kU/L identify children most likely to tolerate peanut, with only a 5% likelihood of failing an oral challenge. This study assists clinicians considering challenges in very young peanut-sensitized children.

Correlation of forced oscillation technique in preschool children with cystic fibrosis with pulmonary inflammation.

BACKGROUND: Lung disease in cystic fibrosis (CF) is established in early childhood with recurrent bacterial infections and inflammation. Using spirometry, the effect of this early lung damage cannot be measured until a child is 6 years of age when some irreversible lung damage may already have occurred. Techniques for measurement of lung function in infants and young children include raised volume rapid thoracic compression (RVRTC) and low frequency forced oscillation (LFFOT). The aim of this study was to investigate the role of inflammation and infection on a population of infants and young children with CF and to determine whether lung function in this population (measured by LFFOT) is affected by early lung disease. METHODS: Lung function was measured by LFFOT in 24 children undergoing bronchoalveolar lavage (BAL) on 27 occasions as part of an annual programme while still under general anaesthesia. Following lung function testing, three aliquots of saline were instilled into the right middle or lower lobe. The first aliquot retrieved was processed for the detection of microbes, and the remaining aliquots were pooled to assess inflammatory markers (cytology, IL-8, NE, LTB(4)). RESULTS: Inflammation (percentage and number of neutrophils) was significantly higher in children with infections (p<0.001, p = 0.04, respectively), but not in those with symptoms. Several markers of inflammation significantly correlated with LFFOT parameters (R, G, and eta). CONCLUSION: Infections and inflammation are established before symptoms are apparent. Inflammation is correlated with measures of parenchymal changes in lung function measured by LFFOT.

Purification and characterization of a putative fimbrial protein/receptor of Porphyromonas gingivalis.

Porphyromonas gingivalis has been implicated as a major aetiological agent in certain forms of periodontal disease, P. gingivalis is a Gram-negative, asaccharolytic bacterium that obtains energy from the fermentation of amino acids derived from the hydrolysis of host protein. Virulence factors of this bacterium include the capsule, fimbrial adhesins, cytotoxins and extracellular hydrolytic enzymes. A 43 kDa fimbrillin from P. gingivalis has been isolated and characterized. However, there is evidence that a second type of fimbria exists on the surface of P. gingivalis. A putative P. gingivalis fimbrial protein from a membrane preparation has been isolated and identified. This protein was shown to be reactive with sera from patients harbouring P. gingivalis. A 28 kDa protein fragment was purified by anion exchange, gel filtration and reversed-phase chromatography. N-terminal sequence analysis of the 28 kDa protein fragment revealed homology to the fimbrial precursor protein of Dichelobacter nodosus. A peptide corresponding to the N-terminal 26 amino acyl residues of the 28 kDa protein fragment was synthesized and used to raise antibodies to the protein. Western blot analysis after SDS-PAGE of a P. gingivalis membrane preparation using the antibodies raised to the synthetic peptide detected three proteins of 36, 41 and 67 kDa. When protease inhibitors were not included in the extraction procedure only the 36 and 41 kDa bands were detected. It would appear, therefore, that the intact protein has an M(r) of 67 kDa and that the 28, 36 and 41 kDa bands represent protein fragments produced by endogenous proteolytic activity. Based on sequence homology, the 67 kDa protein is possibly a sub-unit of a second P. gingivalis fimbrial type or a surface receptor.

Factors influencing the potential establishment of the winter tick (Dermacentor albipictus) in Alaska.

The winter tick (Dermacentor albipictus) is not known to occur in Alaska. Survival and development of free-living (i.e., non-host-associated) stages of the tick were studied at three sites in central and southern Alaska. Female ticks survived, oviposited, and eggs hatched at all sites. Hatch success was low at one site where summer temperatures were low. Results suggest that establishment of winter ticks in Alaska following accidental translocation is possible, but several factors would affect such establishment.

Baseline body temperatures, heart rates, and respiratory rates of moose in Alaska.

Baseline body temperatures (BT), heart rates (HR) and respiratory rates (RR) were obtained from Alaskan moose (Alces alces gigas Miller) at the Moose Research Center (MRC), Alaska. Excitability, seasons and drugs influenced the values to varying degrees. Excitability was the most influential factor. Safe expected ranges were: BT 38.4 to 38.9 C, HR 70 to 91 beats/min (b/min), and RR 13 to 40 respirations/min (r/min). These ranges incorporated all seasons, a central nervous system depressant drug and a paralyzing drug. Values which may be considered critical and an indication that corrective action should be taken include: BT 40.2 C, HR 102 b/min, and RR 40 r/min. It is recommended that persons trained in monitoring vital signs be on hand during moose capture and immobilization procedures.

Comparison and assessment of drugs used to immobilize Alaskan gray wolves (Canis lupus) and wolverines (Gulo gulo) from a helicopter.

One hundred and three Alaskan gray wolves and 12 wolverines were immobilized in the Nelchina and upper Susitna River Basins of southcentral Alaska between March 1977 and May 1981. Sixty-five wolves were immobilized with a mixture of phencyclidine HCl and promazine HCl (PP/HCl); 38 wolves were immobilized with etorphine HCl (EHCl) and 12 wolverines were immobilized with EHCl or with a mixture of EHCl and xylazine HCl (XHCl). Phencyclidine HCl is no longer commercially available and an assessment of etorphine HCl as a replacement drug was made. Etorphine HCl dosage of 2.5 mg/wolf proved to be a suitable replacement for PP/HCl for immobilizing wolves while 0.7 mg EHCl with 50 mg XHCl appeared suitable for wolverines.

Beta-endorphin levels in blood from selected Alaskan mammals.

Blood samples were analyzed for beta-endorphin from 43 non-torpid black bear (Ursus americanus), 8 torpid black bear, 3 non-torpid brown bear (Ursus arctos), 14 moose (Alces alces), 6 mountain goats (Oreamnus americanus) and 30 Steller sea lions (Eumetopias jubatus). Beta-endorphin levels were detected in all species sampled and there were no significant differences in levels among non-torpid black bear, brown bear and sea lions. Also, no differences were detected between moose and mountain goats, but all other comparisons were significantly different (P less than 0.001). Torpid black bear had higher levels than all other groups. Moose and mountain goats had the lowest levels. The possibility of beta-endorphin influencing behavior and physiology of mammals is discussed.

Moose milk and hair element levels and relationships.

Milk was collected from 21 Alaskan moose (Alces alces gigas) at the Kenai Moose Research Center (MRC), Soldotna, Alaska nad analyzed by atomic absorption spectroscopy for Al, As, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Mo, Na, Ni, Pb, Se and Zn. Hair samples were collected from 100 moose at the MRC to correspond with the lactation period and serve as a metabolic indicator of mineral elements stored in tissue. Published analyses of bovine milk were compared to moose milk; Al, Fe, Se and Zn were higher in moose milk by factors of 1.6 to 290. Elements potentially influenced by nutrition and those determined genetically were also considered. Elements in moose milk and hair values were compared, since mineral element levels in hair potentially reflect the availability and intake of these elements. Calcium and Mg were the only values in hair lower than the values in milk (factors of 4.2 and 1.5 respectively). Moose, as well as domestic cattle, apparently are subjected to lactation stress by the genetically determined levels of Ca and Mg in milk.