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.     

Cefepime/amikacin in the empirical antibacterial therapy for patients with hemoblastosis of different forms]

The results of the use of cefepime (Maxipime) combination with amikacin vs ceftriaxon combination with amikacin in the treatment of 80 patients with different forms of hemoblastosis are presented. Severe infectious complications in the patients were associated with prolonged and deep neutropenia during inductive or antirelapsing chemotherapy. All the patients in the trial were from the group of high risk of infectious complications with the blood neutrophil count under 100 cells/microliter. The duration of neutropenia averaged 12 days (7 to 15). The average period of the treatment with cefepime and amikacin equaled to 13 days (8 to 16). The treatment with cefepime + amikacin was successful in 38 out of 40 patients (95%). The average period of the treatment with ceftriaxon and amikacin equaled to 14 days (7 to 18). The efficacy of the treatment with ceftriaxon + amikacin was 60% (24 patients out of 40).     

Does maternal condition or predation risk influence small mammal population dynamics?

There is strong debate over whether the intrinsic traits of individuals or the extrinsic environment exert the greater influence on small mammal population dynamics. We test the roles of maternal effects (an intrinsic factor) and predation risk (an extrinsic factor) in the population dynamics of wild strain house mice using a 2-factor enclosure experiment. Pre-release supplemental feeding with a high-fat diet created female treatment founders that were 6–10% heavier than controls, a condition that we predicted would be passed on as a maternal effect. Predation risk was enhanced using regular application of predator (red fox Vulpes vulpes ) scats. Founder populations of six females and six males released into eight, 15×15 m enclosures showed near exponential population growth over 17 weeks (maximum 3 generations). But there were no responses to either treatment in terms of survival, inherited body weights, fecundity or population size. We suggest that elevated maternal condition may have only minor and transient intergenerational effects with little long-term consequence. We also suggest that the general significance of predator scats as a cue to predation risk to alter prey behaviour may have been overestimated. Hence our results question the role of either factor in causing long-term responses that influence condition to affect population processes.     

Neuronal Basis of Innate Olfactory Attraction to Ethanol in Drosophila

The decision to move towards a mating partner or a food source is essential for life. The mechanisms underlying these behaviors are not well understood. Here, we investigated the role of octopamine – the invertebrate analogue of noradrenaline – in innate olfactory attraction to ethanol. We confirmed that preference is caused via an olfactory stimulus by dissecting the function of the olfactory co-receptor Orco (formally known as OR83b). Orco function is not required for ethanol recognition per se, however it plays a role in context dependent recognition of ethanol. Odor-evoked ethanol preference requires the function of Tbh (Tyramine β hydroxalyse), the rate-limiting enzyme of octopamine synthesis. In addition, neuronal activity in a subset of octopaminergic neurons is necessary for olfactory ethanol preference. Notably, a specific neuronal activation pattern of tyraminergic/octopaminergic neurons elicit preference and is therefore sufficient to induce preference. In contrast, dopamine dependent increase in locomotor activity is not sufficient for olfactory ethanol preference. Consistent with the role of noradrenaline in mammalian drug induced rewards, we provide evidence that in adult Drosophila the octopaminergic neurotransmitter functions as a reinforcer and that the molecular dissection of the innate attraction to ethanol uncovers the basic properties of a response selection system.     

Stabilizing ER Ca2+ Channel Function as an Early Preventative Strategy for Alzheimer’s Disease

Alzheimer’s disease (AD) is a devastating neurodegenerative condition with no known cure. While current therapies target late-stage amyloid formation and cholinergic tone, to date, these strategies have proven ineffective at preventing disease progression. The reasons for this may be varied, and could reflect late intervention, or, that earlier pathogenic mechanisms have been overlooked and permitted to accelerate the disease process. One such example would include synaptic pathology, the disease component strongly associated with cognitive impairment. Dysregulated Ca²⁺ homeostasis may be one of the critical factors driving synaptic dysfunction. One of the earliest pathophysiological indicators in mutant presenilin (PS) AD mice is increased intracellular Ca²⁺ signaling, predominantly through the ER-localized inositol triphosphate (IP₃) and ryanodine receptors (RyR). In particular, the RyR-mediated Ca²⁺ upregulation within synaptic compartments is associated with altered synaptic homeostasis and network depression at early (presymptomatic) AD stages. Here, we offer an alternative approach to AD therapeutics by stabilizing early pathogenic mechanisms associated with synaptic abnormalities. We targeted the RyR as a means to prevent disease progression, and sub-chronically treated AD mouse models (4-weeks) with a novel formulation of the RyR inhibitor, dantrolene. Using 2-photon Ca²⁺ imaging and patch clamp recordings, we demonstrate that dantrolene treatment fully normalizes ER Ca²⁺ signaling within somatic and dendritic compartments in early and later-stage AD mice in hippocampal slices. Additionally, the elevated RyR2 levels in AD mice are restored to control levels with dantrolene treatment, as are synaptic transmission and synaptic plasticity. Aβ deposition within the cortex and hippocampus is also reduced in dantrolene-treated AD mice. In this study, we highlight the pivotal role of Ca²⁺ aberrations in AD, and propose a novel strategy to preserve synaptic function, and thereby cognitive function, in early AD patients.     

cDNA sequence and predicted primary structure of the gamma subunit from the ATP synthase from Chlamydomonas reinhardtii

The 1701-base nucleotide sequence (not including the poly(A) tail) of a cDNA for the gamma subunit of the ATP synthase from Chlamydomonas reinhardtii was determined. A start translation sequence, 23 bases in from the 5' end, initiates an 1074-base-long open reading frame. The sequence of the first 21 amino acids at the amino-terminal end of the mature gamma subunit from C. reinhardtii was determined and compared to the deduced amino acid sequence of the open reading frame. From this it was determined that the mature protein contains 323 amino acids, with the first 35 amino acids probably being part of the transit peptide. The length of the mature protein is the same as that for the mature gamma subunit from spinach, for which only a few of the amino acids of the transit peptide are known. The similarity of the two mature proteins at the nucleotide level is 56% while at the amino acid level it is 77%. In addition, the 3 cysteines, which in spinach are involved in the energy-linked catalytic functions of the ATP synthase, are conserved in the predicted amino acid sequence for the gamma subunit from C. reinhardtii. In contrast, the mature C. reinhardtii gamma subunit contains 3 additional cysteine residues not found in the spinach gamma subunit.     

Regulation of glutaminase by exogenous glutamate,ammonia and 2-oxoglutarate in synaptosomal enriched preparation from rat brain

Phosphate activated glutaminase in synaptosomal enriched preparation from rat brain is very sensitive to inhibition by low concentration of glutamate, ammonia and 2-oxoglutarate when added to the incubation medium at pH 7.6. By increasing the concentration of either of these compounds up to 0.5 mM a pronounced initial inhibition is followed by little or no further effect when the concentration is increased beyond this level. By lowering the pH of the reaction mixture to 7.0, the inhibition by glutamate is almost abolished and that of ammonia reduced. Glutamate inhibits mainly the N-ethylmaleimide-sensitive fraction of glutaminase which previously is suggested to be localized to the outer phase of the mitochondrial inner membrane, whereas ammonia inhibits both the N-ethylmaleimidesensitive and-insensitive fraction. Evidence has been produced to show that the inhibition by 2-oxoglutarate is caused by glutamate formation by aminotransferase reactions. Since 2-oxoglutarate is produced by the tricarboxylic acid cycle, the operation of this cycle may regulate the glutaminase reaction by controlling glutamate formation via the aminotransferase reactions.Abbreviations used NEM N-ethylmaleimide - PAG phosphate activated glutaminase - AOA aminooxyacetic acid     

Hydrophobia, lectin binding, and molecular order in the stratum corneum of adult and neonatal rats and in human breast cells in culture.

A search for differences due to ANS staining (hydrophobia), Con A and PNA binding capacity, and birefringence was carried out on stratified epithelia of rat skin and human breast cells (HBC) in culture. Microfluorimetric measurements confirm that the ANS fluorescence of the stratum corneum from adults is higher than that of newborns. HBC exhibited an unexpected deep ANS-fluorescence. Differences in the binding capacity of the epithelial layers to Con A and PNA were detected with advancing age. Retardation measurements revealed that the form birefringence of the stratum corneum is higher in adult animals specially as revealed by the fact that its form birefringence curve branch from n = 1.414 to n = 1.479 is steeper, i.e. depict higher values. The strong birefringence of the cytoplasmic tonofilaments presented by cultured human breast cells was considered an unexpected finding and attributed to changes that the cells underwent following the in vitro conditions.