TH1-biased immunity induced by exposure to Antarctic winter

Relationship between Urinary Metabolomic Profiles and Depressive Episode in Antarctica

Antarctic expeditions have a high risk of participant depression owing to long stays and isolated environments. By quantifying the stress state and changes in biomolecules over time before the onset of depressive symptoms, predictive markers of depression can be explored. Here, we evaluated the psychological changes in 30 participants in the Japanese Antarctic Research Expedition using the Patient Health Questionnaire-9 (PHQ-9). Urinary samples were collected every three months for a year, and comprehensive urinary metabolomic profiles were quantified using liquid chromatography time-of-flight mass spectrometry. Five participants showed major depressive episodes (PHQ-9 ≥ 10) at 12 months. The urinary metabolites between these participants and the 25 unaffected participants were compared at individual metabolite and pathway levels. The individual comparisons showed the most significant differences at 12 months in 14 metabolites, including ornithine and beta-alanine. Data from shorter stays showed less significant differences. In contrast, pathway and enrichment analyses showed the most significant difference at three months and a less significant difference at longer stays. These time transitions of urinary metabolites could help in the development of urinary biomarkers to detect subjects with depressive episodes at an early stage.

Co-varying neighborhood analysis identifies cell populations associated with phenotypes of interest from single-cell transcriptomics

As single-cell datasets grow in sample size, there is a critical need to characterize cell states that vary across samples and associate with sample attributes, such as clinical phenotypes. Current statistical approaches typically map cells to clusters and then assess differences in cluster abundance. Here we present co-varying neighborhood analysis (CNA), an unbiased method to identify associated cell populations with greater flexibility than cluster-based approaches. CNA characterizes dominant axes of variation across samples by identifying groups of small regions in transcriptional space-termed neighborhoods-that co-vary in abundance across samples, suggesting shared function or regulation. CNA performs statistical testing for associations between any sample-level attribute and the abundances of these co-varying neighborhood groups. Simulations show that CNA enables more sensitive and accurate identification of disease-associated cell states than a cluster-based approach. When applied to published datasets, CNA captures a Notch activation signature in rheumatoid arthritis, identifies monocyte populations expanded in sepsis and identifies a novel T cell population associated with progression to active tuberculosis.

Changes in the clinical phenotype and behavior of pediatric luminal Crohn's disease at diagnosis in the last decade

BACKGROUND AND AIMS

The aims of this study were to describe the trends in the behavior of pediatric CD during the last decade and to describe the seasonal variation of disease presentation.

METHODS

Patients under 18 years old and diagnosed between 2009 and 2019 were included. The clinical, endoscopic, histological, and laboratory data were collected from the medical records. We analyzed the trends of these parameters according to the year and season of diagnosis.

RESULTS

654 patients were included in the study. The number of incident CD cases increased yearly. Patients diagnosed between 2015 and 2019 were younger at diagnosis (OR 2.53, p = 0.02), had more perianal diseases (OR: 2.30, p < 0.0001) and more granulomas (OR: 1.61, p = 0.003), but fewer eosinophils (OR: 0.35, p < 0.0001) and less chronic lymphoplasmacytic infiltrate (OR: 0.56, p = 0.008) as compared to the 2009-2014 cohort. There was fewer CD diagnosis during winter. Patients diagnosed in the fall had lower PCDAIs, less failure to thrive and less extensive digestive involvement. Colonic disease was significantly more frequent during summer and fall.

CONCLUSION

The clinical and histological phenotype of CD has changed over time and there are important seasonal trends in the frequency and severity on disease behavior suggesting possible disease triggers.

Immune sensitization during 1 year in the Antarctic high-altitude Concordia Environment

BACKGROUND

Antarctica is a challenging environment for humans. It serves as a spaceflight ground analog, reflecting some conditions of long-duration exploration class space missions. The French-Italian Concordia station in interior Antarctica is a high-fidelity analog, located 1000 km from the coast, at an altitude of 3232 m. The aim of this field study was to characterize the extent, dynamics, and key mechanisms of the immune adaptation in humans overwintering at Concordia for 1 year.

METHODS

This study assessed immune functions in fourteen crewmembers. Quantitative and phenotypic analyses from human blood were performed using onsite flow cytometry together with specific tests on receptor-dependent and receptor-independent functional innate and adaptive immune responses. Transcriptome analyses and quantitative identification of key response genes were assessed.

RESULTS

Dynamic immune activation and a two-step escalation/activation pattern were observed. The early phase was characterized by moderately sensitized global immune responses, while after 3-4 months, immune responses were highly upregulated. The cytokine responses to an ex vivo stimulation were markedly raised above baseline levels. These functional observations were reflected at the gene transcriptional level in particular through the modulation of hypoxia-driven pathways.

CONCLUSIONS

This study revealed unique insights into the extent, dynamics, and genetics of immune dysfunctions in humans exposed for 1 year to the Antarctic environment at the Concordia station. The scale of immune function was imbalanced toward a sensitizing of inflammatory pathways.

Age at onset is associated with the seasonal pattern of onset and exacerbation in inflammatory bowel disease

BACKGROUND

Environmental factors are suggested to affect the pathogenesis of several diseases, including inflammatory bowel disease (IBD). The seasonality of disease onset and exacerbation in IBD, however, are not well established. We herein aimed to clarify the disease seasonality and to investigate the underlying characteristics in IBD patients exhibiting seasonality of the disease course.

METHODS

This was a multicenter observational study comprising 20 institutions (Osaka Gut Forum) in Japan. Data were collected from November 2013 to August 2014 using survey forms for physicians and questionnaires for patients. Multivariate analysis was performed to clarify the independent factors affecting disease seasonality.

RESULTS

A total of 1055 patients, including 298 patients with Crohn's disease (CD) and 757 patients with ulcerative colitis (UC), were enrolled. The proportion of CD patients with disease onset in the summer was significantly larger than that in the other seasons, while UC patients exhibited no seasonality of disease onset. More than half of the IBD patients (51.1%) experienced seasonal exacerbation of IBD, and winter was the most common season for disease exacerbation in both CD and UC patients. Seasonality of disease onset and exacerbation was observed in young-onset patients (≤40 years old), but not in elderly-onset patients. Age at onset was independently associated with the seasonality of both disease onset and exacerbation.

CONCLUSIONS

Seasonality of disease onset and exacerbation was observed especially in young-onset IBD patients. Underlying pathophysiologic triggers for disease initiation and exacerbation may be influenced by age at disease onset.

Effects of isolation and confinement on humans-implications for manned space explorations

Human psychology and physiology are significantly altered by isolation and confinement. In light of planned exploration class interplanetary missions, the related adverse effects on the human body need to be explored and defined as they have a large impact on a mission's success. Terrestrial space analogs offer an excellent controlled environment to study some of these stressors during a space mission in isolation without the complex environment of the International Space Station. Participants subjected to these space analog conditions can encounter typical symptoms ranging from neurocognitive changes, fatigue, misaligned circadian rhythm, sleep disorders, altered stress hormone levels, and immune modulatory changes. This review focuses on both the psychological and the physiological responses observed in participants of long-duration spaceflight analog studies, such as Mars500 or Antarctic winter-over. They provide important insight into similarities and differences encountered in each simulated setting. The identification of adverse effects from confinement allows not only the crew to better prepare for but also to design feasible countermeasures that will help support space travelers during exploration class missions in the future.

Different adaptations of Chinese winter-over expeditioners during prolonged Antarctic and sub-Antarctic residence

Prolonged residence in Antarctica is characterized by exposure to isolated, confined, and extreme (ICE) environment. Winter-over expeditioners at research stations often exhibit a complex of psychophysiological symptoms, which varied by stations and sociocultural backgrounds. To understand the different patterns of psychophysiological responses provoked by environmental stress, we conducted a longitudinal assessment of mood and endocrine function in two groups of Chinese expeditioners who were deployed to sub-Antarctic (Great Wall Station, 62°S, N = 12) and Antarctic (Zhongshan Station, 66°S, N = 16) from December 2003 to 2005. Measures of mood, thyroid function, the levels of plasma catecholamine, and circulating interleukins were obtained at departure from China, mid-winter (Antarctica), end of winter (Antarctica), and return to China, respectively. The Zhongshan Station crew experienced significant increases in fatigue, anger, tension, confusion, and decrease in free thyroxine (FT4), norepinephrine (NE), and epinephrine (E) during the winter, increase in thyrotropin (TSH) and total triiodothyronine (TT3) when returning, whereas their counterparts at Great Wall Station only experienced increased TT3 after deployment. Moreover, compared with the Great Wall Station crew, the Zhongshan Station crew exhibited greater increase in anger, greater decrease in FT4, total thyroxine (TT4), NE and E over the winter, and greater increase in TSH when returning. Chinese expeditioners who lived and worked at the Antarctic station and the sub-Antarctic station for over a year showed different change patterns in mood and endocrine hormones. Negative mood and endocrine dysfunction were positively associated with the severity of environment. The study is a supplement to scientific knowledge on psychophysiological variation under ICE environment, which has certain applied value for the development of preventive countermeasures or interventions.

Seasonal variations in onset and exacerbation of inflammatory bowel diseases in children

BACKGROUND

Studies have suggested that inflammatory bowel diseases (IBD) follow a seasonal pattern with regard to their onset and exacerbations. The aim of this study is to determine if there is any seasonal pattern to the onset and exacerbation of IBD in the pediatric population and if the birth of children diagnosed with IBD follows a seasonal pattern.

METHODS

Patients between the ages of 1 and 21 years and with a diagnosis of IBD established between July 1992 and July 2012 were included. Their onset and exacerbations of IBD (year and season) were recorded. The birth dates of the patients were aggregated to determine whether a seasonal birth pattern existed amongst them.

RESULTS

A total of 170 children were included in this study; 34% of patients had their onset in the fall and 19% of them had their onset in the summer. The total number of documented exacerbations was 358 and the median number of exacerbations was two, with a range of 1-11. IBD exacerbations were generally uniformly distributed throughout the year. We did not observe any specific season where children with IBD tended to be born.

CONCLUSIONS

Our data suggests that the onset of symptoms of IBD tends to have a seasonal trend with the highest incidence in the fall. However, we did not observe any association between seasonality and exacerbations in the pediatric population. Moreover, there was no specific season in which children with IBD tended to be born in greater numbers.

Seasonal variation in onset and relapse of IBD and a model to predict the frequency of onset, relapse, and severity of IBD based on artificial neural network

BACKGROUND

Previous research has yielded conflicting data as to whether the natural history of inflammatory bowel disease follows a seasonal pattern. The purpose of this study was (1) to determine whether the frequency of onset and relapse of inflammatory bowel disease follows a seasonal pattern and (2) to establish a model to predict the frequency of onset, relapse, and severity of inflammatory bowel disease (IBD) with meteorological data based on artificial neural network (ANN).

METHOD

Patients with diagnosis of ulcerative colitis (UC) or Crohn's disease (CD) between 2003 and 2011 were investigated according to the occurrence of onset and flares of symptoms. The expected onset or relapse was calculated on a monthly basis over the study period. For artificial neural network (ANN), patients from 2003 to 2010 were assigned as training cohort and patients in 2011 were assigned as validation cohort. Mean square error (MSE) and mean absolute percentage error (MAPE) were used to evaluate the predictive accuracy.

RESULTS

We found no seasonal pattern of onset (P = 0.248) and relapse (P = 0.394) among UC patients. But, the onset (P = 0.015) and relapse (P = 0.004) of CD were associated with seasonal pattern, with a peak in July and August. ANN had average accuracy to predict the frequency of onset (MSE = 0.076, MAPE = 37.58%) and severity of IBD (MSE = 0.065, MAPE = 42.15%) but high accuracy in predicting the frequency of relapse of IBD (MSE = 0.009, MAPE = 17.1%).

CONCLUSION

The frequency of onset and relapse in IBD showed seasonality only in CD, with a peak in July and August, but not in UC. ANN may have its value in predicting the frequency of relapse among patients with IBD.

Changes in immunological and physiological parameters in urine duringAntarctic Scientific Expedition( Short Communication )

The aim of this study was to examine the effect of extreme climatic conditions on certain immunological and physiological parameters in urine in participants of the 9th Czech Antarctic Scientific Expedition, January – February 2015. The studied parameters were pH, number of leukocytes in 1 µl urine and the amount of proteins, nitrites, blood and haemoglobin in urine. A total of 45 urine samples were collected during 3 series of sampling (first pre-departure, second during the first 2 weeks of the stay in Antarctica, and third in the last 2 weeks of the stay). Paired t-test was used for comparison of the data from the Czech Republic and the Antarctica. We have found statistically significant decreases in pH and in the number of leukocytes in urine during the stay in Antarctica. The other parameters showed no changes. We conclude that several factors of the Antarctic environment (with lack of stress, pathogenic microorganisms and pollutants) may have positive effects on certain aspects of human health, and discuss the likely causes and mechanisms.

Wintering in Antarctica: impact on immune response of Indian expeditioners

The immune system is one of the major thrust areas in understanding the effects of adverse climatic conditions on human health. Exposure to the Antarctic environment, such as isolation, cold, UV radiations, magnetic field, blizzards, circadian biorhythms, and fear of the unknown, modify various components of the immune system. Members of Antarctic expeditions suffer significant emotional strain as a result of physical isolation and social deprivation. The present study was performed on winter team members of the 28th Indian Scientific Expedition. In this study, different immunological parameters, which mainly include cytokines (TNF-α, IFN-γ, TGF-β, and IL-4), chemokine MIP-1α, immunoglobulins (IgA, IgM and IgG), cortisol and netrin-1, were assayed in sera by ELISA. Results showed that TNF-α and MIP-1α levels were significantly increased in March, May and August while IFN-γ levels were increased in March and May while TGF-β levels showed a significant decrease in March and May. Serum IgA levels were significantly increased during the entire period of the stressful expedition. Therefore, the present study suggests that serum IgA could be a potential biomarker for extreme environmental conditions.

Serum levels of immunoglobulins (IgG, IgA, IgM) in Antarctic summer expeditioners and their relationship with seasickness

The Antarctic continent is full of environmental extremes like isolation, cold, UV exposure, and blizzards etc. The present study was conducted to analyze the effect of ship borne journey and the impact of Antarctic harsh environment on serum immunoglobulin (IgG, IgM, IgA) levels and their relationship with seasickness in Indian expeditioners. It was observed that one month onboard ship journey induced an increase in serum IgA levels and decrease in IgG levels while after being one month off board at the Indian research station Maitri, decreased levels of IgG and increased levels of IgA were found. IgM levels were not altered in comparison to the base line control. Moreover, serum IgG level showed a positive correlation while IgA level showed a negative correlation with seasickness. The stimulation of human peripheral blood mononuclear cells (PBMCs) with serum of expeditioner at different places showed that IgA at lower dose induces the release of pro-inflammatory IL-1β, and IL-6 cytokines from PBMCs while higher dose of IgA decreases proinflammatory cytokine production. The release of anti-inflammatory cytokines TGF-β1 and IL-10 was not significantly altered. Thus, the present study concluded that ship borne journey and Antarctic environment lead to increased serum IgA levels while decreased IgG levels. It also suggests that serum IgA level could be a possible biomarker for environmental stress.

Ship-borne journey induces Th1 cytokines level in antarctic summer expeditioners

It has become apparent that extreme environmental conditions of Antarctic continent alters many immune responses. The present study was conducted on 28th Indian Antarctic expeditioners. The investigations were carried out to explore the effect of multiple stresses like isolation, cold and UV exposure on human immunity. Thirty blood samples were collected between 6 and 7 AM, after an overnight fast at different stages of the expedition - viz. the pre-exposure sample was collected at Delhi on 25(th) October 2008. The expedition started its ship journey from Capetown, on 6(th) January, 2009 and on-board blood was collected on 31(st) January 2009. After 1 month stay at Maitri, blood was collected on 3(rd) March 2009. Different parameters studied included levels of cytokines, chemokines and cortisol. The ship-borne journey induced a dramatic increase in TNF-α, IFN-γ, and B cell activating factor (BAFF) levels and moderate decreases in TGF-β and cortisol levels. However, after being off board for 1 month at Maitri station, levels of above cytokines, cortisol and BAFF were decreased but MIP-1α was significantly increased. These data for the first time suggest that ship-borne journey to the Antarctic continent results in tremendous stress to the body, which eventually resulted in increased TH1-biased immunity.

Seasonality in flares and months of births of patients with ulcerative colitis in a Chinese population

BACKGROUND AND AIMS

Reports on seasonality in flares or months of births of inflammatory bowel disease patients have been inconsistent, but little data are available in a Chinese population. The aim of this study was to determine whether symptom flares and births of ulcerative colitis (UC) patients follow a seasonal pattern.

METHODS

Patients with a diagnosis of UC established between January 1990 and December 2007 were investigated according to the occurrence of flares of symptoms and months of births. The expected flares or births were calculated on a monthly basis over the study period, taking into consideration the difference in the number of days in the month in each year.

RESULTS

A total of 409 UC patients were included in the study, and 1030 flares of symptoms were determined. The peak number of flares occurred during the spring and summer, especially in June, while the nadir occurred in the winter, especially in January (chi(2) ((11 df))=32.74304, P<0.005). The symptom flares also occurred more frequently in the spring-summer period than in the autumn-winter period (chi(2) ((3 df))=22.1269, P<0.001). There was no statistical difference in birth distribution on a monthly or seasonal (spring, summer, autumn, winter) basis. However, the births of UC patients occurred more frequently in the autumn-winter period than in the spring-summer period when the data were merged into these two seasonal components (chi(2) ((1 df))=5.255607, P<0.025).

CONCLUSIONS

The data indicate that the symptom flares of UC occurred more frequently in the spring and summer, while the births of UC patients occurred more often in the autumn and winter. Environmental recurring factors may be associated with the symptom flares of UC, and these factors during pregnancy or postpartum may be associated with susceptibility to UC later in life.

Vitamin D supplementation during Antarctic winter

BACKGROUND

Persons with limited exposure to ultraviolet B light, including space travelers, may not receive enough vitamin D. Recent studies indicate that optimal serum 25-hydroxyvitamin D [25(OH)D] should be > or = 80 nmol/L.

OBJECTIVE

This study was designed to evaluate the effectiveness of 3 doses of vitamin D to raise and maintain 25(OH)D to a concentration >80 nmol/L in persons with limited ultraviolet B light exposure.

DESIGN

This was a 5-mo, prospective, randomized, double-blind study of vitamin D supplementation. It was conducted during winter in Antarctica at the McMurdo Station, when ultraviolet B radiation levels are essentially zero. The 55 subjects were randomly divided into 3 groups for vitamin D supplementation: 2000 IU/d (n = 18), 1000 IU/d (n = 19), and 400 IU/d (n = 18). An additional 7 subjects did not take supplements or took supplements of their own choosing. Blood samples were collected about every 2 mo during the winter.

RESULTS

About 5 mo after supplementation started, 25(OH)D increased to 71 +/- 23 nmol/L in the 2000-IU/d group, 63 +/- 25 nmol/L in the 1000-IU/d group, and 57 +/- 15 nmol/L in the 400-IU/d group and decreased to 34 +/- 12 nmol/L in the group not taking supplements.

CONCLUSIONS

These data will enable us to provide space crews with evidence-based recommendations for vitamin D supplementation. The findings also have implications for other persons with limited ultraviolet light exposure, including polar workers and the elderly.

The effect of season on cytokine expression in multiple sclerosis and healthy subjects

We measured the levels of IFNgamma, TNFalpha, Il-4 and Il-10 produced by mitogen-stimulated peripheral blood mononuclear cells (PBMC) from healthy people, and those with the relapse/remitting form of multiple sclerosis. Blood was taken in summer and winter. Healthy people had a summer excess of Il-4, Il-10 and TNFalpha, and a winter excess of IFNgamma. Untreated MS cases had a summer excess of Il-10, whereas those treated with Interferon-beta had lower levels of all cytokines, and displayed no seasonal effect.

Immune system changes during simulated planetary exploration on Devon Island, high arctic

Background

Dysregulation of the immune system has been shown to occur during spaceflight, although the detailed nature of the phenomenon and the clinical risks for exploration class missions have yet to be established. Also, the growing clinical significance of immune system evaluation combined with epidemic infectious disease rates in third world countries provides a strong rationale for the development of field-compatible clinical immunology techniques and equipment. In July 2002 NASA performed a comprehensive immune assessment on field team members participating in the Haughton-Mars Project (HMP) on Devon Island in the high Canadian Arctic. The purpose of the study was to evaluate the effect of mission-associated stressors on the human immune system. To perform the study, the development of techniques for processing immune samples in remote field locations was required. Ten HMP-2002 participants volunteered for the study. A field protocol was developed at NASA-JSC for performing sample collection, blood staining/processing for immunophenotype analysis, whole-blood mitogenic culture for functional assessments and cell-sample preservation on-location at Devon Island. Specific assays included peripheral leukocyte distribution; constitutively activated T cells, intracellular cytokine profiles, plasma cortisol and EBV viral antibody levels. Study timepoints were 30 days prior to mission start, mid-mission and 60 days after mission completion.

Results

The protocol developed for immune sample processing in remote field locations functioned properly. Samples were processed on Devon Island, and stabilized for subsequent analysis at the Johnson Space Center in Houston. The data indicated that some phenotype, immune function and stress hormone changes occurred in the HMP field participants that were largely distinct from pre-mission baseline and post-mission recovery data. These immune changes appear similar to those observed in astronauts following spaceflight.

Conclusion

The immune system changes described during the HMP field deployment validate the use of the HMP as a ground-based spaceflight/planetary exploration analog for some aspects of human physiology. The sample processing protocol developed for this study may have applications for immune studies in remote terrestrial field locations. Elements of this protocol could possibly be adapted for future in-flight immunology studies conducted during space missions.

Chromatin remodeling at the Th2 cytokine gene loci in human type 2 helper T cells

The differentiation of mouse naïve CD4 T cells into type 2 helper (Th2) cells is accompanied by chromatin remodeling at the nucleosomes associated with the IL-4, IL-13 and IL-5 genes. However, little is known about how chromatin remodeling of these Th2 cytokine gene loci occurs in human Th2 cells. We herein established an in vitro culture system in which both Th1 and Th2 cells are efficiently differentiated from human peripheral blood naïve CD4 T cells. This system allowed us to investigate the chromatin status at the Th2 cytokine gene loci and the IFNgamma locus in human Th2 and Th1 cells, respectively. In typical individuals, the chromatin remodeling indicated by the induction of hyper-acetylation of histone H3 lysine 9 and hyper-methylation of histone H3 lysine 4 was induced at the whole Th2 cytokine gene loci in developing Th2 cells. We more precisely assessed the methylation status of histone H3 lysine 4 at the Th2 cytokine gene loci (IL-5 exon 3, IL-5 promoter, IL-5/RAD50 intergenic region, RAD50 promoter, CGRE, CNS1, IL-13 promoter, IL-4 promoter, and VA enhancer regions) and the IFNgamma locus in developing Th1 and Th2 cells prepared from 20 healthy volunteers. Th2-cell specific chromatin remodeling was induced at most of the Th2 cytokine gene loci. In parallel with the induction of chromatin remodeling, GATA3 mRNA was preferentially expressed in developing Th2 cells, whereas T-bet, HLX and ROG mRNA was selectively expressed in developing Th1 cells.

Seasonal variations in onset of symptoms in Crohn's disease

BACKGROUND

Seasonal variations in onset of symptoms have been reported in ulcerative colitis but not in Crohn's disease. AIM.: To investigate whether our inflammatory bowel diseases patients presented seasonal variations in onset of symptoms.

PATIENTS AND METHODS

Patients with a diagnosis of inflammatory bowel diseases established between 1995 and May 2004, and consecutively observed from June 2003 to May 2004, were included in the study. Onset of symptoms (year, season and month) was recorded. Expected onsets with a uniform distribution during the year were calculated and compared to observed onsets.

STATISTICAL ANALYSIS

chi-square test, odds ratio (95% confidence interval).

RESULTS

Overall 425 inflammatory bowel diseases patients were enrolled. Onset of symptoms (year and season) was established in 353/425 patients (83%; 150 Crohn's disease; 203 ulcerative colitis). Onset of symptoms in inflammatory bowel diseases patients as a whole occurred more frequently in spring-summer compared to autumn-winter (odds ratio 1.39; 95% confidence interval 1.03-1.87; p<0.03). This variation was observed in Crohn's disease (odds ratio 1.59; 95% confidence interval 1.00-2.51; p<0.05) and a similar trend, although not significant, was observed in ulcerative colitis (odds ratio 1.27; 95% confidence interval 0.86-1.88; p=0.27).

CONCLUSIONS

These data indicate that onset of Crohn's disease symptoms occurred more frequently during spring-summer. A similar trend was observed in ulcerative colitis. Environmental factors, such as associated infections, smoking, use of drugs and seasonal changes in immune function may be responsible for triggering the clinical onset of inflammatory bowel diseases.

Considerations for non-invasive in-flight monitoring of astronaut immune status with potential use of MEMS and NEMS devices

The dynamics of how astronauts' immune systems respond to space flight have been studied extensively, but the complex process has not to date been thoroughly characterized, nor have the underlying principles of what causes the immune system to change in microgravity been fully determined. Statistically significant results regarding overall immunological effects in space have not yet been established due to the relatively limited amount of experimental data available, and are further complicated by the findings not showing systematically reproducible trends. Collecting in vivo data during flight without affecting the system being measured would increase understanding of the immune response process. The aims of this paper are to briefly review the current knowledge regarding how the immune system is altered in space flight; to present a group of candidate biomarkers that could be useful for in-flight monitoring and give an overview of the current methods used to measure these markers; and finally, to further establish the need and usefulness of incorporating real-time analytical techniques for in-flight assessment of astronaut health, emphasizing the potential application of MEMS/NEMS devices.

The allergy epidemic extends beyond the past few decades

BACKGROUND

Increased prevalence of allergic diseases in western societies has been described as an epidemic. The precise turning point for the epidemic and the antigens responsible for it remain obscure.

OBJECTIVE

To evaluate how the prevalence of atopic disease has changed in terms of detectable sensitization to aeroallergens and dietary allergens in a cross-sectional comparison of subjects from birth cohorts more than 60 years apart.

METHODS

We studied four groups of 100 subjects each (at ages 7, 27, 47 and 67 years), representing those born in 1990, 1963-66, 1943-46 and in 1923-26, respectively. Serum total and specific IgE concentrations against aeroallergens and dietary allergens were determined. A questionnaire elicited information on symptoms, allergic diseases and medication.

RESULTS

The proportion of subjects with detectable IgE antibodies against aeroallergens increased consistently from the oldest to the youngest birth cohorts; chi2 trend=56.809, P<0.0001. Similar progression was not seen in sensitization to dietary allergens. The proportion of those with diagnosed asthma differed significantly (chi2=13.45, P=0.004) across the birth cohorts. The lowest prevalence of asthma and sensitization to dietary allergens was detected in those born in 1943-46, i.e. during or immediately after World War II.

CONCLUSION

Prevalence of sensitization to airborne allergens, unlike that to dietary allergens, has increased over a long period of time. Our results support the concept of the immune function being programmed by external factors early in life. They also call for caution when interpretations of the pace and possible causes of the allergy epidemic are made on the basis of short-term studies.

Effect of relocating to areas of reduced atmospheric particulate matter levels on the human circulating leukocyte count

A high level of atmospheric particulate matter induces an increase in circulating polymorphonuclear leukocyte (PMN) counts and an increase in serum inflammatory cytokine levels. The particulate level in Antarctica is extremely low compared with that in industrial countries. We hypothesized that this low level would reduce circulating leukocyte counts and serum inflammatory cytokine levels in people visiting Antarctica from industrial countries. The number density of particulates with aerodynamic diameters of <10.0 μm was measured in Japan and in Antarctica during the 41st Japanese Antarctic Research Expedition. Circulating leukocyte counts, granulocyte colony-stimulating factor and interleukin-6 levels, and pulmonary function were determined at regular intervals in 39 expedition members. The particulate number density was <1% of that measured in Japan. Total leukocytes, segmented and band-formed PMN, monocyte counts, and serum interleukin-6 levels decreased in Antarctica compared with the initial values measured in Japan. Pulmonary function parameters did not change except for maximal voluntary ventilation. Particulate matter levels had more significant effects on segmented PMN, band-formed PMN, and monocyte counts than cigarette smoking and the type of work. Exposure to reduced atmospheric particulates is considered to be a major factor for decreasing circulating leukocyte counts and serum cytokine levels.

Advances in asthma, allergy and immunology series 2004: basic and clinical immunology

This review highlights some of the most significant advances in basic and clinical immunology that were published from August 2002 to December 2003, focusing on manuscripts that appeared in the Journal. Articles selected were those considered most relevant to Journal readers. With regard to basic immunology, this report includes articles describing FcepsilonRI expression in mucosal Langerhans cells and type II dendritic cells, mechanisms of TH1 and TH2 regulation, the role of Foxp3 in the development of CD4+CD25+ regulatory T cells, and the increasing importance of Toll receptors in immunity. Articles related to clinical immunology that were selected include the first report of lymphocyte subsets values from a large cohort of normal children; the description of new genetic defects in primary immunodeficiencies; a description of the complications of gene therapy for X-linked severe combined immunodeficiency; a report of 79 patients with hyper-IgM syndrome; a report of the mechanism of action and complications of intravenous immunoglobulin; a report of new approaches for immunotherapy; and an article on advances in HIV infection and management, including a report of defensins, small molecules with anti-HIV properties. Also summarized is an article that studied the immune system during a prolonged stay in the Antarctic, a model for human studies on the effect of environmental conditions similar to space expeditions.