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MBio Aug 2023Changes to gut environmental factors such as pH and osmolality due to disease or drugs correlate with major shifts in microbiome composition; however, we currently...
Changes to gut environmental factors such as pH and osmolality due to disease or drugs correlate with major shifts in microbiome composition; however, we currently cannot predict which species can tolerate such changes or how the community will be affected. Here, we assessed the growth of 92 representative human gut bacterial strains spanning 28 families across multiple pH values and osmolalities . The ability to grow in extreme pH or osmolality conditions correlated with the availability of known stress response genes in many cases, but not all, indicating that novel pathways may participate in protecting against acid or osmotic stresses. Machine learning analysis uncovered genes or subsystems that are predictive of differential tolerance in either acid or osmotic stress. For osmotic stress, we corroborated the increased abundance of these genes during osmotic perturbation. The growth of specific taxa in limiting conditions in isolation correlated with survival in complex communities and in an mouse model of diet-induced intestinal acidification. Our data show that stress tolerance results are generalizable and that physical parameters may supersede interspecies interactions in determining the relative abundance of community members. This study provides insight into the ability of the microbiota to respond to common perturbations that may be encountered in the gut and provides a list of genes that correlate with increased ability to survive in these conditions. IMPORTANCE To achieve greater predictability in microbiota studies, it is crucial to consider physical environmental factors such as pH and particle concentration, as they play a pivotal role in influencing bacterial function and survival. For example, pH is significantly altered in various diseases, including cancers, inflammatory bowel disease, as well in the case of over-the-counter drug use. Additionally, conditions like malabsorption can affect particle concentration. In our study, we investigate how changes in environmental pH and osmolality can serve as predictive indicators of bacterial growth and abundance. Our research provides a comprehensive resource for anticipating shifts in microbial composition and gene abundance during complex perturbations. Moreover, our findings underscore the significance of the physical environment as a major driver of bacterial composition. Finally, this work emphasizes the necessity of incorporating physical measurements into animal and clinical studies to better understand the factors influencing shifts in microbiota abundance.
Topics: Humans; Animals; Mice; Gastrointestinal Microbiome; Microbiota; Bacteria; Osmolar Concentration; Hydrogen-Ion Concentration
PubMed: 37432034
DOI: 10.1128/mbio.00753-23 -
Zebrafish Feb 2022The zebrafish is a teleost model species widely used in developmental genetics, biomedical studies, toxicology, and drug screening. Despite the interest of this species...
The zebrafish is a teleost model species widely used in developmental genetics, biomedical studies, toxicology, and drug screening. Despite the interest of this species in research, little is known through indirect observations about its blood osmolality, which is a key parameter for diverse experiments. In this study, we directly measured blood osmolality using nano-osmometry at different stages of zebrafish postembryonic development. We found that blood osmolality is close to 240 mOsm·kg in early larvae. It progressively increased to ∼270 mOsm·kg during the larval development before reaching ∼300 mOsm·kg after metamorphosis in juveniles and later in adults. These ontogenetic changes in blood osmolality illustrate the physiological changes in osmoregulation associated with postembryonic development, including metamorphosis. These values are of practical interest for adjusting the osmolality of fixatives and cell and tissue culture media for research using zebrafish as a model.
Topics: Animals; Larva; Osmolar Concentration; Zebrafish
PubMed: 35128940
DOI: 10.1089/zeb.2021.0075 -
BMJ Open Diabetes Research & Care Dec 2023This study aimed to evaluate the relationship between both low and high osmolarity and the risk of all-cause and cause-specific mortality in diabetic population.
AIMS
This study aimed to evaluate the relationship between both low and high osmolarity and the risk of all-cause and cause-specific mortality in diabetic population.
METHODS
All participants were included from the National Health and Nutrition Examination Survey 1999-2014. Baseline serum osmolality was determined from laboratory tests and cause of death from national death records. HRs and 95% CIs for all-cause mortality and cardiovascular mortality in diabetes were estimated using Cox proportional regression analysis. The non-linear relationship was explored using restricted cubic splines regression.
RESULTS
Among 7622 individuals with diabetes, 1983 (12.4%) died during a total of 3.26 thousand person-years of follow-up. Compared with the reference category (281-284 mmol/kg), the multivariable-adjusted HRs and 95% CIs for all-cause mortality were 1.27 (1.16-1.40; p<0.001) in the lowest osmolality category (<201 mmol/kg) and 1.18 (1.09-1.28; p<0.001) in the highest osmolality category (>312 mmol/kg). Restricted cubic splines results showed that serum levels of osmolality had a U-shaped association with the risk of all-cause mortality, and L-shaped relationship with the risk of cardiovascular death.
CONCLUSIONS
Both low osmolality and high osmolality were predictive of increased all-cause mortality in patients with diabetes, supporting a U-shaped relationship. Also, a lower serum osmolality increased the risk of cardiovascular mortality.
Topics: Humans; Nutrition Surveys; Risk Factors; Diabetes Mellitus; Cardiovascular Diseases; Osmolar Concentration
PubMed: 38135453
DOI: 10.1136/bmjdrc-2023-003826 -
Journal of Veterinary Diagnostic... Jan 2020Urine specific gravity (USG), which is usually measured by refractometry, is an important indicator of renal concentrating ability. Few studies have evaluated...
Urine specific gravity (USG), which is usually measured by refractometry, is an important indicator of renal concentrating ability. Few studies have evaluated refractometers with separate scales for canine and feline urine. Variables such as protein content or storage time may influence the USG. We compared the effects of measuring USG with a refractometer with single or separate scales for canine and feline urine, investigated inter- and intra-observer variability, and measured agreement between whole urine and supernatant. We evaluated the correlation between USG and osmolality, the influence of urinary protein on USG and osmolality, and the impact of storage time up to 6 mo. We examined 252 canine and 126 feline samples. Bland-Altman analysis revealed higher USG values of the single-scale refractometer than the dual-scale refractometer, with a mean difference (bias) of < 0.001 for canine and 0.003 for feline specimens. Inter- and intra-observer variability were acceptable. Good agreement was shown between USG of whole urine and supernatant. Correlations between USG and osmolality were excellent (0.98-0.99, < 0.001). Proteinuria up to 1 g/L had no major impact on USG or osmolality. Storage time had no significant effect on USG. The difference between the refractometers is clinically irrelevant, and the use of a refractometer with separate feline and canine scales is unnecessary. Whole urine and supernatant stored up to 6 mo can both be used for USG measurement. The influence of proteinuria <1 g/L on USG and osmolality is negligible.
Topics: Animals; Cats; Dogs; Osmolar Concentration; Refractometry; Specific Gravity; Urinalysis
PubMed: 31876254
DOI: 10.1177/1040638719896785 -
International Journal of Molecular... Nov 2023Ensuring food security for the global population is a ceaseless and critical issue. However, high-salinity and high-alkalinity levels can harm agricultural yields... (Review)
Review
Ensuring food security for the global population is a ceaseless and critical issue. However, high-salinity and high-alkalinity levels can harm agricultural yields throughout large areas, even in largely agricultural countries, such as China. Various physical and chemical treatments have been employed in different locations to mitigate high salinity and alkalinity but their effects have been minimal. Numerous researchers have recently focused on developing effective and environmentally friendly biological treatments. Endophytes, which are naturally occurring and abundant in plants, retain many of the same characteristics of plants owing to their simultaneous evolution. Therefore, extraction of endophytes from salt-tolerant plants for managing plant growth in saline-alkali soils has become an important research topic. This extraction indicates that the soil environment can be fundamentally improved, and the signaling pathways of plants can be altered to increase their defense capacity, and can even be inherited to ensure lasting efficacy. This study discusses the direct and indirect means by which plant endophytes mitigate the effects of plant salinity stress that have been observed in recent years.
Topics: Endophytes; Salinity; Alkalies; Salt Tolerance; Salt-Tolerant Plants
PubMed: 38069239
DOI: 10.3390/ijms242316917 -
Scientific Reports Nov 2022Slime expelled by velvet worms entraps prey insects within seconds in a hardened biopolymer network that matches the mechanical strength of industrial polymers. While...
Slime expelled by velvet worms entraps prey insects within seconds in a hardened biopolymer network that matches the mechanical strength of industrial polymers. While the mechanic stimuli-responsive nature and building blocks of the polymerization are known, it is still unclear how the velvet worms' slime hardens so fast. Here, we investigated the slime for the first time, not only after, but also before expulsion. Further, we investigated the slime's micro- and nanostructures in-depth. Besides the previously reported protein nanoglobules, carbohydrates, and lipids, we discovered abundant encapsulated phosphate and carbonate salts. We also detected CO bubbles during the hardening of the slime. These findings, along with further observations, suggest that the encapsulated salts in expelled slime rapidly dissolve and neutralize in a baking-powder-like reaction, which seems to accelerate the drying of the slime. The proteins' conformation and aggregation are thus influenced by shear stress and the salts' neutralization reaction, increasing the slime's pH and ionic strength. These insights into the drying process of the velvet worm's slime demonstrate how naturally evolved polymerizations can unwind in seconds, and could inspire new polymers that are stimuli-responsive or fast-drying under ambient conditions.
Topics: Salts; Proteins; Biopolymers; Nanostructures; Osmolar Concentration
PubMed: 36357497
DOI: 10.1038/s41598-022-23523-z -
Clinical Chemistry and Laboratory... Nov 2022Automated machine learning (AutoML) tools can help clinical laboratory professionals to develop machine learning models. The objective of this study was to develop a...
OBJECTIVES
Automated machine learning (AutoML) tools can help clinical laboratory professionals to develop machine learning models. The objective of this study was to develop a novel formula for the estimation of urine osmolality using an AutoML tool and to determine the efficiency of AutoML tools in a clinical laboratory setting.
METHODS
Three hundred routine urinalysis samples were used for reference osmolality and urine clinical chemistry analysis. The H2O AutoML engine completed the machine learning development steps with minimum human intervention. Four feature groups were created, which include different urinalysis measurements according to the Boruta feature selection algorithm. Method comparison statistics including Spearman's correlation, Passing-Bablok regression analysis were performed, and Bland Altman plots were created to compare model predictions with the reference method. The minimum allowable bias (24.17%) from biological variation data was used as the limit of agreement.
RESULTS
The AutoML engine developed a total of 183 ML models. Conductivity and specific gravity had the highest variable importance. Models that include conductivity, specific gravity, and other urinalysis parameters had the highest R (0.70-0.83), and 70-84% of results were within the limit of agreement.
CONCLUSIONS
Combining urinary conductivity with other urinalysis parameters using validated machine learning models can yield a promising surrogate. Additionally, AutoML tools facilitate the machine learning development cycle and should be considered for developing ML models in clinical laboratories.
Topics: Humans; Specific Gravity; Urinalysis; Osmolar Concentration; Machine Learning; Algorithms
PubMed: 35778953
DOI: 10.1515/cclm-2022-0415 -
Nutrients Jan 2023The risk of dehydration in older adults with neurocognitive disorder (NCD) is controversial. The purpose of this study was to assess hydration status, its determinants,...
The risk of dehydration in older adults with neurocognitive disorder (NCD) is controversial. The purpose of this study was to assess hydration status, its determinants, and water intake sources in older adults with NCD. A sample of 30 participants (≥60 years) was included. Sociodemographic, clinical data and one 24-h urine sample were collected. Urinary osmolality, sodium, potassium, volume, and creatinine were quantified. Inadequate hydration status corresponded to urine osmolality > 500 mOsm/Kg, or a negative Free Water Reserve (FWR). Two 24-h food recalls were used to assess dietary intake and water sources. The adequacy of total water intake (TWI) was estimated according to EFSA. The contribution of food and beverages to TWI was calculated, and their associations with the urinary osmolality median were tested. Of the total number of participants, 30% were classified as having inadequate hydration status, with no differences between sexes. Regarding TWI, 68.4% of women and 77.8% of men did not reach the reference values. Water (23%), followed by soup (17%), contributed the most to TWI, while vegetables (2%) and alcoholic/other beverages (3%) contributed the least. According to the median urinary osmolality, there was no significant difference in sociodemographic/clinical characteristics. It is critical not to overlook hydration in this vulnerable population.
Topics: Male; Humans; Female; Aged; Water; Drinking; Eating; Biomarkers; Neurocognitive Disorders; Osmolar Concentration; Dehydration
PubMed: 36771256
DOI: 10.3390/nu15030548 -
Nutricion Hospitalaria Sep 2022Water is an essential nutrient for health. Inadequate water intake induces states of dehydration and hypovolemia,causing an increase in plasma osmolality proportional to...
Water is an essential nutrient for health. Inadequate water intake induces states of dehydration and hypovolemia,causing an increase in plasma osmolality proportional to the decrease in body water. Restricting water intake can have harmful effects on cardiovascular health by affecting endothelial function and increasing the viscosity of blood, haematocrit and fibrinogen. Adequate hydration is associated with lower risk of deadly coronary heart disease. Obesity and diabetes are risk factors for cardiovascular disease. Hypohydration is linked to weight gain and obesity. An association between adequate water intake and healthier body composition has been evidenced, there is an inverse relationship between water consumption and weight, body fat and waist circumference. In addition, water consumption decreases the risk of hyperglycemia and typ 2 diabetes. Regarding the composition of water, a positive association between the level of calcium and magnesium and cardiovascular health has been observed. On the other hand, hydration also affects cognitive ability. Decreased fluid intake and dehydration have a negative impact on cognitive performance (attention, memory, learning and executive functions), improving cognitive function with rehydration.
Topics: Cognition; Dehydration; Drinking; Humans; Obesity; Osmolar Concentration; Water
PubMed: 36039990
DOI: 10.20960/nh.04304 -
Journal of Ocular Pharmacology and... 2022Dry eye disease (DED) is classified as aqueous deficient, evaporative, or mixed. We investigated the therapeutic effect of the novel anti-inflammatory drug...
Dry eye disease (DED) is classified as aqueous deficient, evaporative, or mixed. We investigated the therapeutic effect of the novel anti-inflammatory drug phosphosulindac (PS) in rabbit models of DED encompassing its pathogenesis, and its transition to chronicity. We treated three rabbit models of DED with PS (hydrogel formulation) or vehicle topically applied 1 × /day. We induced aqueous-deficient DED (acute and chronic) by injecting Concanavalin A into lacrimal glands; evaporative DED by injecting into the upper eyelid inactivated in complete Freund's adjuvant; and mixed DED through desiccative stress, induced by holding open the eye for 3 h. We determined corneal sensitivity, tear break-up time (TBUT), Schirmer's tear test (STT), tear osmolality, and fluorescein staining of the ocular surface. PS reversed all abnormal DED parameters. In acute DED, PS dose dependently normalized corneal sensitivity and tear osmolality; and improved TBUT, STT, and fluorescein staining. PS normalized corneal sensitivity and improved all other parameters in chronic aqueous-deficient DED. In evaporative DED, PS normalized corneal sensitivity and improved TBUT and fluorescein staining (osmolality and STT were not significantly changed in this model). In the desiccative stress model, PS improved TBUT and fluorescein staining but had no effect on STT or tear osmolality. PS rapidly reversed almost all DED parameters in its three subtypes. The normalization of the suppressed corneal sensitivity suggests the possibility of marked symptomatic relief by PS. The hydrogel formulation allows once-daily dosing. PS merits further development as a potential treatment for DED.
Topics: Animals; Anti-Inflammatory Agents; Delayed-Action Preparations; Disease Models, Animal; Dry Eye Syndromes; Hydrogels; Lacrimal Apparatus; Organophosphorus Compounds; Osmolar Concentration; Rabbits; Sulindac; Tears
PubMed: 34964663
DOI: 10.1089/jop.2021.0050