Seasonal variation in food allergy to apple

The aim of the study was to investigate the possibility of a seasonal variation in reactivity to apples in 27 birch pollen allergic patients. Before and during the birch pollen season 1998, the patients were subjected to double-blind, placebo-controlled food challenges (DBPCFCs) with grated fresh Golden Delicious apple followed by an open food challenge with whole fresh apple. The clinical reactions elicited during the challenges were evaluated both by the patients and the investigators. Moreover, the skin reactivity and the in vitro reactivity to apple were evaluated by skin prick test (SPT), leukocyte histamine release (HR), measurement of specific IgE, and immunoblotting experiments. The sensitivity of the DBPCFC, when compared with the result of the open challenge, was 0.74 (14/19) before the season and 0.80 (16/20) during the season. None of the patients reacted to the blinded challenge without a subsequent reaction to the open challenge. One placebo reaction was registered both before and in season, but not in the same patient. The patient scores of the first positive challenges, and the maximal scores of each combined blinded and open challenge session, were significantly increased during the pollen season (P<0.05). The scores of the open challenge were significantly higher than the scores of the DBPCFC both before the season and during the in-season challenges (P<0.05). Specific IgE against Golden Delicious increased during season (P<0.05), while neither SPT, HR, nor immunoblotting experiments could confirm an increase in reactivity. In conclusion, the results of the oral challenge tests indicated an increase in clinical reactivity to apples during the birch pollen season in birch pollen allergic individuals.     

Inhibitory effects of HgCl2 on excitation-secretion coupling at the motor nerve terminal and excitation-contraction coupling in the muscle cell

Summary 1. Indirect and direct twitch (0.1-Hz) stimulation of the rat phrenic nerve-diaphragm disclosed that the inhibitory effect of HgCl₂, 3.7 × 10^–5 M, on the neuromuscular transmission and in the muscle cell, was accelerated by 10-sec periods of 50-Hz tetanic stimulation every 10 min. This activity-dependent enhancement suggested an inhibitory mechanism of HgCl₂ related to the development of fatigue, like membrane depolarization or decreased excitability, decreased availability of transmitter, or interference with the factors controlling excitation-secretion coupling of the nerve terminal, i.e. (Ca²⁺)₀ or (Ca²⁺)_i, and excitation-contraction coupling in the muscle cell, i.e., (Ca²⁺)_i.2. During both indirect and direct stimulation, HgCl₂-induced inhibition was enhanced markedly by pretreatment with caffeine, which releases Ca²⁺ from endoplasmic and sarcoplasmic reticulum in the nerve terminal and muscle cell, respectively. This caffeine-induced enhancement was completely antagonized by dantrolene, which inhibits the caffeine-induced release. However, dantrolene alone did not antagonize the HgCl₂-induced inhibition.3. Since caffeine depletes the intracellular Ca²⁺ stores of the smooth endoplasmic reticulum, HgCl₂ probably inhibits by binding to SH groups of transport proteins conveying the messenger function of (Ca²⁺)_i. In the muscle cell this leads to inhibition of contraction. In the nerve terminal, an additional enhancement of the HgCl₂-induced inhibition, by inhibiting reuptake of choline by TEA and tetanic stimulation, suggested that HgCl₂ inhibited a (Ca²⁺)_i signal necessary for this limiting factor in resynthesis of acetylcholine.4. The (Ca²⁺)₀ signal necessary for stimulus-induced release of acetylcholine was not affected by HgCl₂. Hyperpolarization in K⁺-free solution antagonized the inhibitory effect of HgCl₂ at indirect stimulation, and Ca²⁺-free solution enhanced the inhibitory effect at direct stimulation. K⁺ depolarization, membrane electric field increase with high Ca²⁺, membrane stabilization with lidocaine, and half-threshold stimulation, did not change the inhibitory effect of HgCl CH₃HgCl, 1.85 × 10^–5 M, disclosed a synergistic interaction with caffeine during direct, but not during indirect, stimulation.     

Temporal relation of antigenaemia and loss of antibodies to core antigens to development of clinical disease in HIV infection.

A total of 276 sequential serum samples from 34 men with antibodies to the human immunodeficiency virus (HIV) followed up for two to seven years were analysed for HIV antigen and antibodies to the viral core and envelope proteins. Results were correlated with clinical outcome and CD4 T lymphocyte count. Both antigenaemia and the disappearance of antibodies to the core protein were associated with development of the acquired immune deficiency syndrome (AIDS) or AIDS related complex and depletion of CD4 cells. Thus AIDS or AIDS related complex developed in eight out of 16 patients with antigenaemia compared with one out of 18 patients without antigenaemia. Low counts of CD4 cells (less than 0.5 X 10(9)/l) were found in 14 of the 16 patients with antigenaemia and five of the 18 without antigenaemia. Nine patients seroconverted to HIV during the study; two of these developed antigenaemia 14 and 16 months after the estimated time of seroconversion. These results show that the late stages of HIV infection are characterised by increased production of antigen and a decrease in antibodies directed against the core protein. Antigenaemia indicates a poor prognosis; and as the antigen test is simple to do and interpret, it may therefore be useful for selecting patients for antiviral treatment.     

Close linkage between X-linked ectodermal dysplasia and a cloned DNA sequence detecting a two allele restriction fragment length polymorphism in the region Xp11-q12

Summary EDA (ectodermal dysplasia, anhidrotic) is an X-linked recessive disorder characterized by hypohidrosis, hypoor anodontia, and hypotrichosis. A possible linkage between the gene for EDA and a number of restriction fragment length polymorphisms (RFLPs) spread over the X chromosome was investigated in two Danish families segregating EDA. No recombination between the gene for EDA and our probe pTAK8, which detects a two allele polymorphism in the region Xp11-q12, was found in nine informative meiotic events (seven of which are phase known), giving a maximal lod score of 2.41 at a recombination fraction of 0.00. This juxtacentromeric location of the gene for EDA agrees well with the linkage data obtained with the other markers used in this study.     

Shoulder muscle load and muscle fatigue among industrial sewing-machine operators

Physiological responses to physical work were assessed for 29 female industrial sewing-machine operators during an 8-h working day under ordinary working conditions. During sewing-machine work, the average (left and right) static load in the trapezius muscle was 9% of the maximal electromyogram (EMG) amplitude (% EMG_max), while the average mean load was 15% EMG_max, and the average peak load was 23% EMG_max. The static load level was unrelated to the muscle strength of the sewing-machine operators, which for the group as a whole was within the normal range. The load levels remained unchanged during the working day, while changes in the EMG mean power frequency and zero crossing frequency rate occurred, both indicating the development of muscle fatigue in left and right trapezius muscle during the working day. In line with this, the rating of perceived exertion in the shoulder and neck region increased during. the working day. Dividing the group of sewing-machine operators into two groups, those with the highest frequency and those with the lowest frequency of shoulder/neck troubles showed that the former group had significantly lower muscle strength, despite the fact that no differences in the surface EMG during sewing were found between the two groups. It was concluded that industrial sewing-machine work involves a pattern of shoulder muscle activity which induces fatiguing processes in the shoulder and neck regions. Furthermore, since the static shoulder muscle load was independent of muscle strength, factors other than working posture may be of significance for the static shoulder muscle load.     

Interleukin-6 release from human skeletal muscle during exercise: relation to AMPK activity.

We tested the hypothesis that IL-6 release from muscle during exercise may be related to muscle activity of 5'-AMP-activated protein kinase (AMPK). Eight healthy, well-trained young men completed two 60-min trials on a bicycle ergometer at 70% of their peak oxygen uptake in either a glycogen-depleted or a glycogen-loaded state. IL-6 was released from the leg already after 10 min of exercise in the glycogen-depleted state, whereas no significant release was observed at any time in the loaded state. Nevertheless, plasma IL-6 increased similarly in the two trials from approximately 0.8 pg/ml at rest to approximately 4.5 pg/ml after 60 min of exercise. Activity of alpha1-AMPK (160%) and alpha2-AMPK (145%) was increased at rest in the glycogen-depleted compared with the loaded situation. During exercise, alpha1-AMPK activity did not change from resting levels in both trials, whereas alpha2-AMPK activity increased only in the glycogen-depleted state. After 60 min of exercise in the glycogen-depleted state, individual values of alpha2-AMPK activity correlated significantly (r = 0.87, P < 0.006) with individual values of IL-6 release as well as with average IL-6 release over the entire 60 min (r = 0.86, P < 0.006). The present data are compatible with a role for AMPK in IL-6 release during exercise or a role for IL-6 in activating AMPK. Alternatively, both AMPK and IL-6 are independent sensors of a low muscle glycogen concentration during exercise. In addition, leg release of IL-6 cannot alone explain the increase in plasma IL-6 during exercise.     

Effects of glucose, glucose plus branched-chain amino acids, or placebo on bike performance over 100km

Madsen, Klavs, Dave A. MacLean, Bente Kiens, and DirkChristensen. Effects of glucose, glucose plus branched-chain aminoacids, or placebo on bike performance over 100 km. J. Appl. Physiol. 81(6): 2644-2650, 1996.This studywas undertaken to determine the effects of ingesting either glucose(trial G) or glucose plusbranched-chain amino acids (BCAA; trialB), compared with placebo (trialP), during prolonged exercise. Nine well-trained cyclists with a maximal oxygen uptake of 63.1 ± 1.5 mlO₂ ^· min^{1 ·} kg¹performed three laboratory trials consisting of 100 km of cycling separated by 7 days between each trial. During these trials, the subjects were encouraged to complete the 100 km as fast as possible ontheir own bicycles connected to a magnetic brake. No differences inperformance times were observed between the three trials (160.1 ± 4.1, 157.2 ± 4.5, and 159.8 ± 3.7 min, respectively). Intrial B, plasma BCAA levels increased from339 ± 28 µM at rest to 1,026 ± 62 µM after exercise(P < 0.01). Plasma ammoniaconcentrations increased during the entire exercise period for allthree trials and were significantly higher intrial B compared withtrials G andP (P < 0.05). The respiratory exchange ratio was similar in the threetrials during the first 90 min of exercise; thereafter, it tended todrop more in trial P than intrials G andB. These data suggest that neitherglucose nor glucose plus BCAA ingestion during 100 km of cyclingenhance performance in well-trained cyclists.

     

Polyacrylamide gel electrophoretic analysis of herpes simplex virus type 1 immunoprecipitates obtained by quantitative immunoelectrophoresis in antibody-containing agarose gel.

Crossed immunoelectrophoresis was used to characterize herpes simplex virus type 1 (HSV-1) antigens produced by infected HEp-2 cells. We report on a method for analyzing the polypeptide content in individual antigen-antibody precipitates eluted from the second-dimensional agarose gel. Four glycoprotein antigens of HSV-1, Ag-8, Ag-11, Ag-6, and Ag-3, were isolated and analyzed for polypeptide content. The molecular weights of the polypeptides are presented.     

Immunocytochemical demonstration of somatotropin-like and prolactin-like activity in the brain of Calamoichthys calabaricus (Actinopterygii)

Summary Cellular binding of anti-bSTH and anti-oPRL IgG is demonstrated in the brain and the pituitary gland of the African freshwater fish Calamoichthys calabaricus by means of the unlabeled antibody enzyme method at the light microscopic level. In the brain, somatotropin and prolactin are demonstrated in separate neurons in the preoptic area. The somatotropinergic and prolactinergic perikarya are distinct from those of the hypothalamic-hypophysial neurosecretory neurons, i.e., those stainable with aldehyde fuchsin presumed to be vasotocinergic and isotocinergic. The somatotropinergic and prolactinergic neuronal perikarya give rise to separate beaded axons which pass either ventroposteriorly into the infundibulum, terminating in the neurohypophysis, or ventro-laterally through the wall of the preoptic recess, terminating near the superficial capillary bed covering this part of the brain surface. Moreover, coarse dendrite-like processes of both kinds of immuno-reactive neurons extend towards, and end in, the third ventricle. Binding sites in the brain to antisera against hLH, hFSH, hTSH and anti-(1–24) ACTH IgG, all reactive in the pituitary, are not observed in the neurons confined to the preoptic area.Supported by the Danish Natural Sciences Research CouncilThe authors wish to thank Professor Dr K.G. Wingstrand, University of Copenhagen, Denmark, for placing two series of C. calabaricus at their disposal. They would also like to thank the National Institute of Arthritis, Metabolism and Digestive Diseases, Bethesda, USA, for the generous gift of antisera against the subunits of human LH, TSH and FSH, and likewise Dr L. Hummer, Glostrup Hospital, Copenhagen, Denmark, for the gift of the anti-(1-24)ACTH IgG     

Oxygen uptake of carp,Cyprinus carpio,swimming in normoxic and hypoxic water

Synopsis Oxygen uptake (V_{o 2}) was measured in carp of approximately 40 cm length swimming at controlled variable oxygen tensions (P_{o 2}). At P_{o 2}> 120 mm Hg V_{o 2} increased with an increase in swimming speed from 5.6 to 11.3 cm · sec^–1. Extrapolation of V_{o 2} to zero activity at P_{o 2} = 140 mm Hg revealed a standard O₂ uptake of 36.7 ml O₂ · kg^–1 · h^–1 at 20° C. At the lowest swimming speed (5.6 cm · s^–1) the oxygen uptake increased when the water P_{o 2} was reduced. A near doubling in V_{o 2} was seen at P_{o 2} = 70 mm Hg compared to 140 mm Hg. At higher swimming speeds in hypoxic water V_{o 2} decreased relative to the values at low swimming speeds. As a result the slope of the lines expressing log V_{o 2} as a function of swimming speed decreased from positive to negative values with decreasing P_{o 2} of the water. pH of blood from the caudal vein drawn before and at termination of swimming at P_{o 2} = 70 mm Hg and 100 mm Hg did not show any decrease in relation to rest values at P_{o 2} = 140 mm Hg. Blood lactate concentration did not increase during swimming at these tensions.