Inhaled allergen-driven CD1c up-regulation and enhanced antigen uptake by activated human respiratory-tract dendritic cells in atopic asthma

Background Dendritic cells (DC) mediate inflammation in rodent models of allergic airway disease, but the role played by human respiratory‐tract DC (hRTDC) in atopic asthma remains poorly defined. Recent data suggest that CD1 antigen presentation by hRTDC may contribute to asthma pathogenesis. Objective To investigate the influence of hRTDC on the balance between atopy and allergic asthma in human subjects and to determine whether CD1 expression by hRTDC is modulated during asthmatic inflammation. Methods Sputum cells were induced from steroid‐naïve, allergen‐challenged and allergen‐naïve subjects (atopic asthmatics, atopic non‐asthmatics and non‐atopic controls). hRTDC were identified using monoclonal antibody labelling and analysis by flow cytometry. Results hRTDC stained HLA‐DR⁺ (negative for markers of other cell lineages) were predominantly myeloid and comprised ∼0.5% of viable sputum cells. Sputum cells were potent stimulators of allogeneic CD4⁺ naïve T cells and enrichment/depletion experiments correlated stimulatory potency with DC numbers. Sputum contained cells that exhibited typical dendritic morphology when analysed by electron microscopy. Myeloid hRTDC were endocytically active, but uptake of FITC‐dextran was enhanced in cells from asthmatics (P<0.001). Despite their increased endocytic capacity, asthmatic myeloid hRTDC appeared mature and expressed increased levels of maturation markers (P<0.05–P<0.001), CD1c, CD1d and langerin (P<0.05). CD1c expression by asthmatic myeloid hRTDC was enhanced upon in vivo allergen challenge (three to ninefold within 24 h; P<0.05). CD11c⁻CD123^high hRTDC were only detected in asthmatic sputum and were increased in number following allergen challenge. Conclusion Despite limited cell numbers, it proved possible to analyse human RTDC in induced sputum, providing evidence that increased antigen uptake and enhanced CD1 presentation by activated hRTDC may contribute to allergic airway disease. CD1 presentation by hRTDC in atopic asthma may therefore constitute a novel target for future intervention strategies.     

Rehabilitation and education are underutilized for mild stroke and TIA sufferers

Purpose: Transient ischemic attack (TIA) and mild stroke represent a large proportion of cerebrovascular events, at high risk of being followed by recurrent, serious events. The importance of early education addressing risk management, secondary prevention and lifestyle modifications is the centerpiece of further stroke prevention. However, delivering education and rehabilitation to this population can be complex and challenging.

Methods: Via synthesis of a narrative review and clinical experience, we explore the unique and inherent complexities of rehabilitation management and education provision for patients following mild stroke and TIA.

Results: A considerable proportion of TIA/mild stroke survivors have ongoing rehabilitation needs that are poorly addressed. The need for rehabilitation in these patients is often overlooked, and available assessment tools lack the sensitivity to identify common subtle impairments in cognition, mood, language and fatigue. Active and accessible education interventions need to be initiated early after the event, and integrated with ongoing rehabilitation management. Priority areas in need of future development in this field are highlighted and discussed.

• Implications for rehabilitation

• Survivors of mild stroke and TIA have ongoing unmet rehabilitation needs and require a unique approach to rehabilitation and education.

• Rehabilitation needs are difficult to assess and poorly addressed in this cohort, where available assessment tools lack the sensitivity required to identify subtle impairments.

• Education needs to be initiated early after the event and involve active engagement of the patient in order to improve stroke knowledge, mood and motivate adherence to lifestyle modifications and secondary prevention.

• Rehabilitation physicians are currently an underutilized resource, who should be more involved in the management of all patients following TIA or mild stroke.

     

Hydrogen Peroxide in Exhaled Breath Condensate (EBC) vs Eosinophil Count in Induced Sputum (IS) in Parenchymal vs Airways Lung Diseases"

We compared exhaled breath condensate (EBC) and induced sputum (IS) for assessing inflammation in pulmonary diseases in patients with obstructive lung disease (n = 20), persistent cough >6 months (n = 20), interstitial lung disease (n = 25) and controls (n = 10). EBC was collected by suspending a Teflon perfluoroalkoxy tube installed in an ice-filled container and connected to a polypropylene test tube. IS was recovered after 20’ inhalation of 3% saline with an ultrasonic nebulizer, and 300 cells were differentially counted in cytospin Giemsa-stained slides. H₂0₂ was measured by a method based on oxidation of phenolsulfonphthalein (phenol red) mediated by horseradish peroxidases and H₂0₂. Pulmonary function tests were performed by conventional methods. H₂0₂ levels in EBC and % eosinophils in IS were significantly different between groups. A positive and significant correlation was found between % eosinophils in IS and the levels of H₂0₂ in EBC for each group and for all patients combined.     

Pathogenesis of small-intestinal mucosal lesions in chronic diarrhea of infancy: I. A light microscopic study

In an effort to increase our understanding of the pathogenesis of chronic protracted diarrhea in infants, we examined 44 jejunal mucosal specimens. Only 3 of the 44 specimens showed a normal mucosa (grade 1). Partial villous atrophy was seen in 17 mucosal specimens (grade 2) with marked patchiness in all of the specimens. Subtotal or total villous atrophy (grade 3) was found in the remaining 24 mucosal biopsies. Plasma cells and macrophages were variably increased and intraepithelial lymphocytes were moderately increased in grades 2 and 3. Eight of ten mucosal biopsy specimens embedded in plastic material and cut at 1-2-mm thickness, showed bacteria of unidentified nature, situated either above the microvillous layer or on the mucosal surface. Both adherent and nonadherent bacteria could be identified in the same specimen. We concluded that severe pathological mucosal changes are common in young infants with protracted diarrhea and that the presence of bacteria may be more common than has previously been documented.     

Allometric scaling and maximum efficiency in physiological eigen time

General optimization results from physics indicate that maximum efficiency of a process, in the sense of minimum overall entropy production, is achieved when the rate of entropy production is constant over time, however not in ordinary clock time but on an, in general varying, "eigen time" scale, intrinsic to the system. We identify the eigen time of a biological system with "physiological time," which generally scales with the 1/4 power of body mass, M(1/4), over a vast range of species. Since it is equally well established that metabolic rate scales as M(3/4), it follows that organisms produce entropy at the same intrinsic rate, fulfilling a necessary condition for maximum efficiency, and are all, furthermore, equally efficient on the physiological eigen time scale.     

Contribution of villous atrophy to reduced intestinal maltase in infants with malnutrition

BACKGROUND: It has been known for many years that small intestinal maltase activities are reduced in malnourished infants and in other patients with villous atrophy. The recent availability of human maltase-glucoamylase cDNA provides the opportunity to test the hypothesis that villous atrophy accounts for the reduced maltase enzyme activity in malnourished infants. METHODS: Mucosal biopsy specimens obtained for clinical evaluation of malnourished infants with poor responses to refeeding were examined by quantitative methods for enzyme activity and mRNA levels. RESULTS: Maltase activity and maltase-glucoamylase mRNA were reduced (approximately 45% of normal). When maltase-glucoamylase message was normalized to villin message, a structural protein expressed only in enterocytes, a preservation of maltase messages in surviving enterocytes was documented. The luminal glucose transporter-villin message was also preserved. CONCLUSIONS: The loss of maltase-glucoamylase message paralleled the reduction in villin message and degree of villous atrophy. The reduced maltase-glucoamylase message also paralleled sucrase-isomaltase message, previously found to be decreased in proportion to villous atrophy of malnourished infants. The data directly demonstrate, for the first time, that the terminal steps of starch 1-4 starch digestion and sucrase-isomaltase 1-6 starch digestion are decreased in malnourished infants, secondary to villous atrophy. These data in prior and present reports suggest that mechanisms underlying the chronic villous atrophy of malnutrition should be a priority for investigations in malnourished infants with slower than expected weight gain during refeeding.