Agreement of specific IgE and skin prick test in an unselected cohort of two-year-old children

The objective of this study was to evaluate the agreement between specific IgE (sIgE) and skin prick test (SPT), and the possible association between total IgE concentration and allergy-related disorders, when performed in an unselected cohort of 353 two-year olds. Median total IgE was within the reference value for two-year-old children regardless of the presence or absence of allergy-related disorders. 18.7% of the children had one or more positive reactions to SPT and/or sIgE in a panel of 12 allergens. Agreement between SPT and sIgE was variable, being best for peanut and poorest for milk. Conclusion: In young children total IgE is of limited value when evaluating allergy-related disorder. The lack of agreement among the positive tests of the sIgE and SPT for some allergens imply that these tests should not be used interchangeably, and both tests should probably be used complementarily when diagnosing atopic sensitization in small children.     

The impact of hyaluronan on monocyte Toll-like receptor expression in term infant cord blood

Aim: To explore the possible effects of hyaluronan, an endogenous mediator of inflammation, on monocyte surface expression of Toll‐like receptors 2 and 4 in human umbilical cord blood ex vivo, and in a model mimicking Gram‐negative neonatal sepsis. Methods: Term infant cord blood was obtained after elective caesarean sections, n = 15. Both unstimulated and lipopolysaccharide‐stimulated (10 ng/mL) blood was incubated with 500 μg/mL high‐ or low‐molecular‐weight hyaluronan for 6 h. Expression of Toll‐like receptors 2 and 4 on monocytes was measured using flow cytometry, and plasma concentrations of proinflammatory cytokines and matrix metalloproteinase 9 were analysed. Results (mean ± SEM): We found a significant decrease in Toll‐like receptor 4 expression in the presence of high‐molecular‐weight hyaluronan (HMW HA) in unstimulated blood (median fluorescence intensity 141 ± 7.3 vs. 163 ± 9.8, p = 0.019). There were no significant changes in Toll‐like receptor 2 expression. Levels of cytokines and matrix metalloproteinase 9 increased in the presence of both forms of hyaluronan. Conclusions: Our results confirm that hyaluronan affects the neonatal immune response. The biological significance of these findings requires further clarification. More studies are needed to validate the possible down‐modulation of Toll‐like receptor 4 exerted by HMW HA.     

Pneumonia and bacteremia due to Kytococcus schroeteri

Kytococcus schroeteri, a saprophyte of the human skin, may cause serious infections in the immunocompromised host. Here, we describe a case of pneumonia and bacteremia due to Kytococcus schroeteri in an immunocompromised patient, successfully treated with linezolid and trimethoprim-sulfamethoxazole.     

Exercise thermoregulatory responses following a 28-day sleep-high train-low regimen

The potentiated exercise-sweating rate observed during acute hypoxia is diminished after a sleep-high train-low (SH-TL) regimen. We tested the hypothesis that this attenuation of the sweating response after SH-TL is compensated for by an increase in heat loss via vasodilatation. Nine male subjects participated in a 28-day SH-TL regimen. Before (pre-), and after (post-) the SH-TL protocol, they performed an $ \dot{V}{\text{O}}_{{ 2 {\text{peak}}}} $ test under normoxia and hypoxia. Additionally, pre- and post-SH-TL they completed three 30-min constant-work rate trials on a cycle ergometer. In one trial, the subjects inspired room air while exercising at 50?% of normoxic $ \dot{V}{\text{O}}_{{ 2 {\text{peak}}}} $ (CT). In the remaining trials, subjects exercised in hypoxia (F_IO₂ 12.5?%), either at the same absolute (HAT) or relative (50?% of hypoxic $ \dot{V}{\text{O}}_{{ 2 {\text{peak}}}} $ ) work rate (HRT) as in CT. Despite similar exercise core temperature responses between pre- and post-SH-TL trials, sweating rate was potentiated in HAT pre-SH-TL [CT: 1.97 (0.42); HRT: 1.86 (0.31); HAT: 2.55 (0.53)?mg?cm^?2?min^?1; p?<?0.05]. Post-SH-TL exercise sweating rate was increased for CT, and remained unchanged in HRT and HAT [CT: 2.42 (0.76); HRT: 2.01 (0.33); HAT: 2.59 (0.30)?mg?cm^?2?min^?1]. Pre-SH-TL, the forearm-fingertip skin temperature difference (Tsk_f?f) was higher in HAT than in CT and HRT by ~3.5°C (p?<?0.05). The inter-condition differences in Tsk_f?f were diminished post-SH-TL. In conclusion, the decrease in sweating rate during hypoxic exercise, following a SH-TL regimen, was countered by an increase in vasodilatation (reduced Tsk_f?f), whereas SH-TL enhanced the sweating response during normoxic exercise. The mechanisms underlying these SH-TL-induced alterations in thermoregulatory responses remain to be settled.     

Effects of motion sickness on thermoregulatory responses in a thermoneutral air environment

Motion sickness (MS) has been identified as a non-thermal factor that can moderate autonomic thermoregulatory responses. It has been shown that MS exaggerates core cooling during immersion in cold (15°C) and luke-warm (28°C) water by attenuating cold-induced vasoconstriction. The aim of the present study was to investigate whether MS affects thermal balance in a thermoneutral air environment. Eleven subjects were exposed to rotation in two conditions, control (CN) and MS. In the CN condition subjects refrained from head movements, whereas in the MS condition they performed a sequence of maximal head movements (left, right, up, down) at 15-s intervals until they were very nauseous. Sweating rate, rectal temperature (T _re), the difference in temperature between the right forearm and tip of the second finger (T _ff) as an index of cutaneous vasomotor tone, perceived MS, thermal comfort and temperature perception were recorded before and during rotation, and during 90-min post-rotation. During the post-rotation period, T _re dropped and sweating rate increased in the MS but not in the CN condition. The T _ff response suggests that MS-induced peripheral vasodilatation which, together with the sweating resulted in increased heat loss. During rotation, subjects perceived temperature to be uncomfortably high, suggesting that MS may also affect thermoregulatory behaviour. It thus appears that also in a thermoneutral air environment MS may substantially affect thermal balance.     

Attachment of capsular polysaccharide to the cell wall in Streptococcus pneumoniae

Streptococcus pneumoniae protects itself from components of the human immune defense system by a thick polysaccharide capsule, which in most serotypes is covalently attached to the cell wall peptidoglycan. Members of the LytR-Cps2A-Psr (LCP) protein family have recently been implicated in the attachment of anionic polymers to peptidoglycan in Gram-positive bacteria, based on genetic evidence from Bacillus subtilis mutant strains and on the crystal structure of S. pneumoniae Cps2A containing a tightly bound polyprenol (pyro)phosphate lipid. Here, we provide evidence that Cps2A and its two pneumococcal homologs, LytR and Psr, contribute to the maintenance of normal capsule levels and to the retention of the capsular polysaccharide at the cell wall in the capsular type 2 S. pneumoniae strain D39. GFP fusions of all three LCP proteins showed enhanced localization at mid-cell, indicating a role in cell wall growth. Single cps2A or psr mutants produced a reduced amount of capsule. A cps2A lytR double mutant showed greatly impaired growth and cell morphology and lost approximately half of the total capsule material into the culture supernatant. We also present the crystal structure of the B. subtilis LCP protein YwtF and provide crystallographic evidence for the phosphotransferase activity of Cps2A, supporting an enzymatic function in the attachment of capsular polysaccharides to cell wall peptidoglycan.     

A cross-sectional study of the relationships between illness insight,internalized stigma,and suicide risk in individuals with schizophrenia

BackgroundSuicide is the major cause of premature death among individuals with schizophrenia. Ironically, one factor that heightens suicide risk is insight into mental illness. Little is known, however, about how insight contributes to suicidality. Recent evidence suggests that negative outcomes related to insight might depend on whether or not the individual accepts the stigmatizing beliefs about the mental illness.ObjectiveThe present study examined the interactive effects of insight and internalized stigma on suicide risk in individuals with schizophrenia. We hypothesized that insight into mental illness and internalized stigma would increase suicide risk and that internalized stigma would moderate the effect of insight on suicide risk.Design and participantsA cross-sectional design was used in this study. A convenience sample of 200 individuals with schizophrenia was recruited from an outpatient clinic in the Eastern catchment area in Alexandria, Egypt.MethodsEligible study participants were individuals with an illness duration not exceeding ten years, currently in outpatient treatment and follow-up, and post-acute or in a stable phase of their disorder. Individuals provided signed consent to participate and were interviewed to assess suicide risk, insight, internalized stigma of mental illness and depression.ResultsSlightly more than 38% of the study participants were classified as having a severe suicide risk. As predicted, suicide risk was positively associated with insight (r = .55, p < .001), internalized stigma (r = .79, p < .001), and depression (r = .78, p < .001). However, the influence of insight was not significant after controlling for covariates in the regression model (β = ?.02, ns). Internalized stigma and depression independently predicted suicide risk, explaining 74% of variance in suicide risk, F_change (6, 191) = 11.54, p < .001. Greater insight was significantly linked to increased levels of internalized stigma (r = .59, p < .001) and depression (r = .61, p < .001). Internalized stigma did not moderate the influence of insight on suicide risk.ConclusionThe present study draws attention to the robust influence of internalized stigma in increasing suicide risk and suggests clinical approaches for managing internalized stigma and suicide risk among individuals with schizophrenia.