The total mass, number, and distribution of immune cells in the human body.

The immune system is a complex network of cells with critical functions in health and disease. However, a comprehensive census of the cells comprising the immune system is lacking. Here, we estimated the abundance of the primary immune cell types throughout all tissues in the human body. We conducted a literature survey and integrated data from multiplexed imaging and methylome-based deconvolution. We also considered cellular mass to determine the distribution of immune cells in terms of both number and total mass. Our results indicate that the immune system of a reference 73 kg man consists of 1.8 × 1012 cells (95% CI 1.5-2.3 × 1012), weighing 1.2 kg (95% CI 0.8-1.9). Lymphocytes constitute 40% of the total number of immune cells and 15% of the mass and are mainly located in the lymph nodes and spleen. Neutrophils account for similar proportions of both the number and total mass of immune cells, with most neutrophils residing in the bone marrow. Macrophages, present in most tissues, account for 10% of immune cells but contribute nearly 50% of the total cellular mass due to their large size. The quantification of immune cells within the human body presented here can serve to understand the immune function better and facilitate quantitative modeling of this vital system.

Patterns in Body Mass Index Changes in Children after Type 1 Diabetes Mellitus Diagnosis.

BACKGROUND: Pediatric patients with newly diagnosed type 1 diabetes mellitus (T1DM) are commonly treated with daily multiple insulin injections or an insulin pump. They tend to have higher body mass index-standard deviation scores (BMI-SDS) than non-diabetic children. OBJECTIVES: To identify patterns in the changes in BMI in the 3 years after T1DM diagnosis, and to discover factors that relate to excessive weight gain. METHODS: This retrospective study included clinical and laboratory data for 194 boys and girls aged 2-18 years at the time of diagnosis and at 1, 2, and 3 years after. Their BMI values were compared to non-diabetic children using BMI percentile and z-score (standard deviation) based on the U.S. Centers for Disease Control and Prevention (CDC) growth charts. RESULTS: Both males and females had low mean BMI-SDS at diagnosis (-0.4499 ± 1.38743 male, 0.3050 ± 1.29887 female) that increased after 1 year (-0.0449 ± 1.14772 male, 0.1451 ± 0.98893 female). Lower glycated hemoglobin (HbA1c) at 1 year correlated with higher BMI-SDS (r = -0.215, P = 0.011). No such correlation was found in the following 2 years. The daily dose of basal insulin correlated with higher BMI-SDS at 1 year (r = 0.183, P = 0.026) and 3 years (r = 0.297, P < 0.01). No association was found between the use of an insulin pump or continuous glucose monitoring and higher BMI-SDS. CONCLUSIONS: BMI-SDS of children with T1DM was lower than average at the time of diagnosis and rose higher than average in the 3 years following. Higher BMI-SDS was not significantly associated with sex or ethnicity. The most prominent increase happened in the first year.

Protective Characteristics of Human Breast Milk on Early Childhood Otitis Media: A Narrative Review.

Introduction: Human breast milk (HBM) contains a complex and dynamically changing variety of factors that contribute to the infant's developing immune system's ability to fight upper respiratory tract infections, including otitis media (OM). We sought to summarize the current evidence on the protective characteristics of HBM, through direct or donated feeding, toward early childhood OM. Methods: For this narrative review, we performed a literature search on OM in the context of HBM feeding in the PubMed, Embase, and Google Scholar databases, between January 1, 2008, and July 1, 2023. Results: Immunoglobulin A (IgA) provides a short-term immunity of 2-3 days against otopathogens causing OM. IgA-mediated immunity is effective against OM up to 7 months of age if breastfeeding continues. The role of transferred IgM and IgG in HBM is unclear. Although there is a potential protective value of microRNA, hormones, oligosaccharides, stem cells, and interleukins present in HBM, their role is unclear. Any duration of breastfeeding is superior to no breastfeeding in OM risk reduction, with a big variability among studies (odds ratio 0.23-0.81, depending on the duration). Duration of breastfeeding ≥6 months was found to be the most effective in OM risk reduction, but there was no evidence of continued benefits after 2 years of age. Expressed breastfeeding was not shown to be more beneficial. The protective values of donor HBM against OM are still undetermined. Conclusion: HBM has numerous components that contribute to protection against early childhood OM.

A novel perceptual trait: gaze predilection for faces during visual exploration.

Humans are social animals and typically tend to seek social interactions. In our daily life we constantly move our gaze to collect visual information which often includes social information, such as others' emotions and intentions. Recent studies began to explore how individuals vary in their gaze behavior. However, these studies focused on basic features of eye movements (such as the length of movements) and did not examine the observer predilection for specific social features such as faces. We preformed two test-retest experiments examining the amount of time individuals fixate directly on faces embedded in images of naturally occurring scenes. We report on stable and robust individual differences in visual predilection for faces across time and tasks. Individuals' preference to fixate on faces could not be explained by a preference for fixating on low-level salient regions (e.g. color, intensity, orientation) nor by individual differences in the Big-Five personality traits. We conclude that during visual exploration individuals vary in the amount of time they direct their gaze towards faces. This tendency is a trait that not only reflects individuals' preferences but also influences the amount of information gathered by each observer, therefore influencing the basis for later cognitive processing and decisions.