Rates of asymptomatic respiratory virus infection across age groups.

Respiratory viral infections are a leading cause of disease worldwide. A variety of respiratory viruses produce infections in humans with effects ranging from asymptomatic to life-treathening. Standard surveillance systems typically only target severe infections (ED outpatients, hospitalisations, deaths) and fail to track asymptomatic or mild infections. Here we performed a large-scale community study across multiple age groups to assess the pathogenicity of 18 respiratory viruses. We enrolled 214 individuals at multiple New York City locations and tested weekly for respiratory viral pathogens, irrespective of symptom status, from fall 2016 to spring 2018. We combined these test results with participant-provided daily records of cold and flu symptoms and used this information to characterise symptom severity by virus and age category. Asymptomatic infection rates exceeded 70% for most viruses, excepting influenza and human metapneumovirus, which produced significantly more severe outcomes. Symptoms were negatively associated with infection frequency, with children displaying the lowest score among age groups. Upper respiratory manifestations were most common for all viruses, whereas systemic effects were less typical. These findings indicate a high burden of asymptomatic respiratory virus infection exists in the general population.

Probiotic supplementation in systemic nickel allergy syndrome patients: study of its effects on lactic acid bacteria population and on clinical symptoms.

AIMS: The study aimed to evaluate the effects of probiotic Lactobacillus reuteri DSM 17938 strain supplementation in patients suffering from systemic nickel allergy syndrome, in terms of modulation of faecal LAB population linked to a reduction of GI and cutaneous symptoms and to an increase of patient's quality of life. METHODS AND RESULTS: A preliminary double-blind randomized placebo-controlled study was planned and a culture-independent method based on denaturing gradient gel electrophoresis (DGGE) analysis coupled to the 16S rRNA gene sequencing was applied to investigate on the dynamics of faecal LAB communities before and during a low-Ni diet, supplemented with the probiotic strain. Moreover, the severity and the frequency of GI and cutaneous reactions as well as patient's clinical condition perception (VAS scores) were estimated by statistical analysis. PCR-DGGE fingerprinting obtained using LAB-specific primers revealed significant shift in faecal community with an increase in biodiversity in patients supplemented with probiotic Lact. reuteri strain. In addition, GI reactions such as symptoms related to meals and type of stools significantly improved only in patients treated with Lact. reuteri, while severity and frequency of cutaneous symptoms (urticaria, itch and eczema) and recurrent abdominal pain (RAP) as well as VAS scores statistically decreased in both groups. CONCLUSIONS: Our preliminary findings suggest that probiotic Lact. reuteri could be a useful supplementation during a low-Ni diet of patients with SNAS, to increase LAB population diversity, which could contribute to restore the intestinal homoeostasis conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: To date, no information is available on probiotics application and on their effects, in terms of intestinal microbiota modulation, on patients suffering from SNAS. Therefore, the identification of dominant LAB community and the study of its shift during the probiotic supplementation could enhance the knowledge of the SNAS syndrome.

Region-specific neural corticosterone patterns differ from plasma in a male songbird.

The adrenal hormone corticosterone (CORT) acts on brain to mediate physiology and behavior. In songbirds, behavioral effects of CORT vary across species, environmental conditions, and life history stage, with several mechanisms proposed to account for these divergent results. Although blood CORT levels are well characterized, few studies measure CORT within the brain itself. Here we used in vivo microdialysis to measure CORT in two regions of the zebra finch brain, the hippocampus (HP) and caudal nidopallium (cNp). Our results show that we can successfully measure physiological levels of CORT in brain within 15- to 30-minute intervals of dialysate collection. Moreover, we found that levels in the cNp were generally lower than levels in the HP. Surprisingly, whereas plasma CORT levels increased in response to a standard stressor, no stress-induced surge was detected in the HP or cNp. In addition, although a diel CORT rhythm was observed in plasma, the rhythm in brain was attenuated and only observed when levels were integrated over a 4-hour time period. Regional differences in brain CORT levels were reflected in local mRNA expression levels of the CORT-inactivating enzyme 11ß-hydroxysteroid dehydrogenase type 2 with levels elevated in the cNp relative to the HP. Region-specific CORT metabolism may therefore play a role in buffering the brain from CORT fluctuations.