Benthic habitats do show a significant latitudinal diversity gradient: A comment on Kinlock et al. (2018)

The latitudinal diversity gradient (LDG) has been investigated for decades, with hundreds of studies focusing on different organisms, regions and habitat types. Meta‐analysis may be considered, therefore, a useful tool to explore the generality and limitations of this remarkable macroecological pattern. The first meta‐analysis exploring variations in the LDG, published by Hillebrand in 2004, revealed that the latitudinal decline in species richness seems to be indeed a general phenomenon. However, Kinlock et al. (2018, Global Ecology and Biogeography, 27, 125–141) revisited recently the challenge of synthesizing individual LDGs and indicated that the phenomenon is not ubiquitous among habitats of the marine realm. More precisely, they indicated that the phenomenon is non‐significant in the benthic habitat. Here, we suggest that the marine habitat categories used by them (i.e., benthic, coral reefs, coastal, open ocean) are not independent and that reclassifying the studies significantly alters one of their main results. By assigning the studies into benthic and pelagic categories, and additionally into coastal or oceanic zones, we show that non‐ambiguous, evolutionarily meaningful marine habitats display a significant latitudinal decline in species richness.     

Possible prognostic significance of p53 and Ki 67 in inverted sinonasal papilloma

The aim of this study is to test the possible prognostic significance of p53 and Ki67 expression in inverted papilloma of the lateral nasal wall and adjacent sinuses regarding their malignant potential and recurrence. 49 biopsies of the lateral nasal wall and adjacent sinuses obtained from 41 patients from three hospitals were investigated. Immunohistochemically demonstrated p53 and Ki67 expression was measured and statistically evaluated. p53 immunoreactivity was demonstrated in most of papillomas with carcinomas but only in two benign papillomas, while Ki67 demonstrated stronger immunoreactivity in carcinomas and surrounding epithelium. Immunohistochemical staining of inverted sinonasal papillomas for p53 and Ki67 can give useful information concerning the existence of synchronous carcinoma and, in case of high Ki67, a hint toward possible recurrence.     

Mesenchymal stem cell‐derived extracellular vesicles reduce senescence and extend health span in mouse models of aging

Aging drives progressive loss of the ability of tissues to recover from stress, partly through loss of somatic stem cell function and increased senescent burden. We demonstrate that bone marrow‐derived mesenchymal stem cells (BM‐MSCs) rapidly senescence and become dysfunctional in culture. Injection of BM‐MSCs from young mice prolonged life span and health span, and conditioned media (CM) from young BM‐MSCs rescued the function of aged stem cells and senescent fibroblasts. Extracellular vesicles (EVs) from young BM‐MSC CM extended life span of Ercc1 ^−/− mice similarly to injection of young BM‐MSCs. Finally, treatment with EVs from MSCs generated from human ES cells reduced senescence in culture and in vivo, and improved health span. Thus, MSC EVs represent an effective and safe approach for conferring the therapeutic effects of adult stem cells, avoiding the risks of tumor development and donor cell rejection. These results demonstrate that MSC‐derived EVs are highly effective senotherapeutics, slowing the progression of aging, and diseases driven by cellular senescence.     

Mechanical role of intraluminal thrombus in aneurysm growth: A computational study

Biomechanics and Modeling in Mechanobiology - Models that seek to improve our current understanding of biochemical processes and predict disease progression have been increasingly in use over the...     

The Selective Antagonism of P2X7 and P2Y1 Receptors Prevents Synaptic Failure and Affects Cell Proliferation Induced by Oxygen and Glucose Deprivation in Rat Dentate Gyrus

Purinergic P2X and P2Y receptors are broadly expressed on both neurons and glial cells in the central nervous system (CNS), including dentate gyrus (DG). The aim of this research was to determine the synaptic and proliferative response of the DG to severe oxygen and glucose deprivation (OGD) in acute rat hippocampal slices and to investigate the contribution of P2X₇ and P2Y₁ receptor antagonism to recovery of synaptic activity after OGD. Extracellular field excitatory post-synaptic potentials (fEPSPs) in granule cells of the DG were recorded from rat hippocampal slices. Nine-min OGD elicited an irreversible loss of fEPSP and was invariably followed by the appearance of anoxic depolarization (AD). Application of MRS2179 (selective antagonist of P2Y₁ receptor) and BBG (selective antagonist of P2X₇ receptor), before and during OGD, prevented AD appearance and allowed a significant recovery of neurotransmission after 9-min OGD. The effects of 9-min OGD on proliferation and maturation of cells localized in the subgranular zone (SGZ) of slices prepared from rats treated with 5-Bromo-2′-deoxyuridine (BrdU) were investigated. Slices were further incubated with an immature neuron marker, doublecortin (DCX). The number of BrdU⁺ cells in the SGZ was significantly decreased 6 hours after OGD. This effect was antagonized by BBG, but not by MRS2179. Twenty-four hours after 9-min OGD, the number of BrdU⁺ cells returned to control values and a significant increase of DCX immunofluorescence was observed. This phenomenon was still evident when BBG, but not MRS2179, was applied during OGD. Furthermore, the P2Y₁ antagonist reduced the number of BrdU⁺ cells at this time. The data demonstrate that P2X₇ and P2Y₁ activation contributes to early damage induced by OGD in the DG. At later stages after the insult, P2Y₁ receptors might play an additional and different role in promoting cell proliferation and maturation in the DG.     

NOD2 and CCDC122-LACC1 genes are associated with leprosy susceptibility in Brazilians

Leprosy is a complex disease with phenotypes strongly influenced by genetic variation. A Chinese genome-wide association study (GWAS) depicted novel genes and pathways associated with leprosy susceptibility, only partially replicated by independent studies in different ethnicities. Here, we describe the results of a validation and replication study of the Chinese GWAS in Brazilians, using a stepwise strategy that involved two family-based and three independent case–control samples, resulting in 3,614 individuals enrolled. First, we genotyped a family-based sample for 36 tag single-nucleotide polymorphisms (SNPs) of five genes located in four different candidate loci: CCDC122-LACC1, NOD2, TNFSF15 and RIPK2. Association between leprosy and tag SNPs at NOD2 (rs8057431) and CCDC122-LACC1 (rs4942254) was then replicated in three additional, independent samples (combined OR_AA = 0.49, P = 1.39e?06; OR_CC = 0.72, P = 0.003, respectively). These results clearly implicate the NOD2 pathway in the regulation of leprosy susceptibility across diverse populations.     

Excessive Daytime Sleepiness and Body Composition: A Population-Based Study of Adults

Background

Excessive daytime sleepiness (EDS) is often associated with increased adiposity, particularly when assessed in the context of samples of sleep-disordered patients; however, it is unclear if this relationship is sustained among non-clinical, population-based cohorts. This study aimed to investigate the relationship between EDS and a number of body composition markers among a population-based sample of men and women.

Methods

This study assessed 1066 women aged 21–94 yr (median = 51 yr, IQR 35–66), and 911 men aged 24–92 yr (median = 60 yr, IQR 46–73) who participated in the Geelong Osteoporosis Study (GOS) between the years 2001 and 2008. Total body fat mass was determined from whole body dual-energy X-ray absorptiometry scans, and anthropometric parameters (weight, height, and waist circumference) were measured. Lifestyle and health information was collected via self-report. Sleepiness was assessed using the Epworth Sleepiness Scale (ESS). Scores of ≥10 were considered indicative of EDS.

Results

Women: After adjusting for age, alcohol intake, antidepressant medication use and physical activity, EDS was associated with greater waist circumference and body mass index (BMI). EDS was also associated with 1.5–1.6-fold increased odds of being overweight or obese. Men: After adjusting for age, alcohol use, physical activity and smoking status, EDS was associated with greater BMI. These findings were not explained by the use of sedative or antidepressant medication. EDS was also associated with 1.5-fold increased likelihood of being obese, independent of these factors. No differences in lean mass, %body fat, or %lean mass were detected between those with and without EDS for men or women.

Conclusions

These data suggest that EDS is associated with several anthropometric adiposity profiles, independent of associated lifestyle and health factors. Among women, symptoms of EDS are pervasive at both overweight and obese BMI classifications; suggesting a need for further clinical examination to assess possible temporal associations with underlying sleep pathology.     

SAR studies of non-zinc-chelating MMP-13 inhibitors: Improving selectivity and metabolic stability

SAR studies to improve the selectivity and metabolic stability of a class of recently discovered MMP-13 inhibitors are reported. Improved selectivity was achieved by modifying interactions with the S1′ pocket. Metabolic stability was improved through reduction of inhibitor lipophilicity. This translated into lower in vivo clearance for the preferred compound.