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At least 19 recordsLinked to original sources
PubMed2026

Microbial membrane transporters reveal trace metal niche adaptation in distinct water masses of the Southern Ocean.

BACKGROUND: Trace metals are co-factors for enzymes that are essential for microbial metabolism and the cycling of major elements. Membrane transporters allow microbes to sense and react to trace elements in the environment and to balance their uptake and export for the regulation of intracellular metal homeostasis. The acquisition and efflux of trace metals could lead to reciprocal feedbacks between microbes and the surrounding environment. Whether these processes vary among trace metals and across habitats is presently not known. We used membrane transporters into and out of the cell as indicators for the uptake and efflux of trace metals and provide a detailed picture of the distribution of the respective genes in distinct provinces in surface waters and in subsurface water masses across a transect in the Southern Indian Ocean. RESULTS: We observed marked spatial and vertical patterns in normalized gene abundances of transporters of iron (Fe), manganese (Mn), nickel (Ni) and copper (Cu). Changes in gene abundances were specific to the type of transporter and trace metal, and pronounced differences between surface and specific water masses emerged. We found an enrichment in genes related to efflux and homeostasis of Fe, Ni and Cu in two water masses of the deep ocean that are North Atlantic Deep Water (NADW) and Lower Circumpolar Deep Water (LCDW). This pattern was observed on the community level and for metagenome-assembled genomes (MAGs) affiliated with Alteromonadaceae and Burkholderiaceae that were abundant in these two water masses. CONCLUSIONS: The enrichment in trace metal efflux and resistance genes points to microbially mediated processes, exerted by homeostasis, with potential influence on the trace metal speciation and distribution in specific water masses in the deep ocean. The gene repertoire and distinct distribution pattern of the taxa identified as potential key players could reflect an adaptation to these old water masses with trace metals acting as selective driver. Video Abstract.

Membrane Transport Proteins↗
PubMed2024

Mendelian randomization analysis reveals higher whole body water mass may increase risk of bacterial infections.

BACKGROUND AND PURPOSE: The association of water loading with several infections remains unclear. Observational studies are hard to investigate definitively due to potential confounders. In this study, we employed Mendelian randomization (MR) analysis to assess the association between genetically predicted whole body water mass (BWM) and several infections. METHODS: BWM levels were predicted among 331,315 Europeans in UK Biobank using 418 SNPs associated with BWM. For outcomes, we used genome-wide association data from the UK Biobank and FinnGen consortium, including sepsis, pneumonia, intestinal infections, urinary tract infections (UTIs) and skin and soft tissue infections (SSTIs). Inverse-variance weighted MR analyses as well as a series of sensitivity analyses were conducted. RESULTS: Genetic prediction of BWM is associated with an increased risk of sepsis (OR 1.34; 95% CI 1.19 to 1.51; P = 1.57 × 10- 6), pneumonia (OR: 1.17; 95% CI 1.08 to 1.29; P = 3.53 × 10- 4), UTIs (OR: 1.26; 95% CI 1.16 to 1.37; P = 6.29 × 10- 8), and SSTIs (OR: 1.57; 95% CI 1.25 to 1.96; P = 7.35 × 10- 5). In the sepsis and pneumonia subgroup analyses, the relationship between BWM and infection was observed in bacterial but not in viral infections. Suggestive evidence suggests that BWM has an effect on viral intestinal infections (OR: 0.86; 95% CI 0.75 to 0.99; P = 0.03). There is limited evidence of an association between BWM levels and bacteria intestinal infections, and genitourinary tract infection (GUI) in pregnancy. In addition, MR analyses supported the risk of BWM for several edematous diseases. However, multivariable MR analysis shows that the associations of BWM with sepsis, pneumonia, UTIs and SSTIs remains unaffected when accounting for these traits. CONCLUSIONS: In this study, the causal relationship between BWM and infectious diseases was systematically investigated. Further prospective studies are necessary to validate these findings.

Humans↗
PubMed2026

Metabolomic differences in the Ophiura sarsii complex from the Yellow Sea Cold Water Mass and Bering Sea Cold Pool.

Metabolomics provides a functional readout of cellular physiology and can reveal metabolite-level differences associated with environmental and evolutionary contexts. Here, we used GC-MS- and LC-MS-based metabolomics to characterize metabolic profiles of the Ophiura sarsii complex from the Yellow Sea Cold Water Mass (YSCWM) and the Bering Sea Cold Pool (BSCP). This metabolomics analysis identified 398 LC-MS/MS and 87 GC-MS/MS differential metabolites (DEMs). Marked metabolic differences were observed between the two taxa, involving antioxidant-related metabolites, central carbon-related intermediates, osmolyte-associated compounds, and membrane lipid components. O. sarsii vadicola from the YSCWM showed higher levels of glutathione, glucose, citric acid, D-ribulose 5-phosphate, and unsaturated lipid-related metabolites, indicating differences in antioxidant-related and energy-associated metabolic profiles. By contrast, O. sarsii from the BSCP was characterized by higher levels of sugar alcohols, particularly myo-inositol, together with differences in membrane lipid-associated metabolites. These results provide metabolomics-based evidence for metabolite-level physiological differences between two members of the O. sarsii complex sampled from the Yellow Sea Cold Water Mass and the Bering Sea Cold Pool, while the relative contributions of lineage divergence and site-specific environmental variation remain to be tested experimentally.

Metabolomics↗
PubMed2026

Admixture and Selection Driven by El Niño-Southern Oscillation Events Shape the Genetic Structure of Octopus mimus-O. hubbsorum Complex Across the Humboldt and South Equatorial Current Transition Zone.

Marine transition zones, where contrasting water masses converge, can function as natural laboratories for studying admixture and early stages of speciation. The genomic structure of the eastern Pacific Octopus mimus-O. hubbsorum complex was investigated by analyzing whole-genome sequencing data from 67 individuals sampled along the west coast of the Americas, spanning Mexico and the Peruvian coast. This includes the South Equatorial Current, the transition zone, and the Humboldt Current System. The mitochondrial genomes fell into two major genetic clades that largely corresponded to the warm-water northern (O. hubbsorum) and cold-water southern (O. mimus) lineages. Analyses of the nuclear genomes revealed the same bipartite structure but also identified a broad admixture zone characterized by two different admixed clades (Admixed-Cold and Admixed-Warm). The results suggest that episodic relaxation of oceanographic barriers during El Niño-Southern Oscillation (ENSO) events promotes secondary contact and gene flow, resulting in admixed individuals recurrently during ENSO years. However, the survival of these admixed individuals depends on the adaptive genetic composition of each organism and the prevailing environmental conditions. Outlier SNP analysis supports these findings, where the Admixed-Cold cluster shares mainly the adaptive genetic component identified as outliers in O. mimus, while Admixed-Warm is linked to those in O. hubbsorum. The O. mimus-O. hubbsorum complex is currently occupying a gray zone of speciation, in which selection and climate-driven connectivity act in tandem to shape genomic divergence.

gene flow↗
PubMedDate not supplied

[Myxosporidia of the cartilaginous fish of the Patagonian shelf (shore of Argentina)].

5 species of myxosporidians of the genus Chloromyxum were found in the gall bladder of Chondrostei from the Pathagonian shelf (Argentina coast). 4 species of them are new ones. This indicates that the species Chloromyxum leydigi mentioned for all Chondrostei is a collective species which needs a revision. Caudal filaments and ribs of the valves of spores of myxosporidians are more developed in species parasitic in fishes getting food from water mass and predators and to a lesser extent in species getting food from the bottom.

Animals↗
PubMed1977

Total body water and lean body mass estimated by ethanol dilution.

Total body water (TBW) was determined on 35 subjects with a tritium (HTO) and an ethanol (ETH) dilution method, the latter using breath analyses for blood ethanol content. Lean body mass (LBM) was estimated by hydrostatic weighing. Mean values for water fraction (TBW/wt) were 0.618 +/- 0.05 with HTO and 0.603 +/- 0.06 with ETH. The difference was not significant. The correlation between the two methods was highly significant (r = 0.90, SEE = 3.5 liters, P less than 0.0001). High correlations were also found between TBW and LBM with either method for TBW (r = 0.94 with HTO, r = 0.91 with ETH). Mean values for TBW/LBM were 0.735 with HTO and 0.717 with ETH. The ETH method compares favorably with the HTO, it has the advantage that it is nonradioactive and can be repeated daily if necessary.

Body Composition↗
PubMed1979

Changes in fat, fat-free mass and body water in human normal pregnancy.

Measurements of body weight, total body water and total body potassium (40K) were made serially on three occasions during pregnancy and once post partum in 27 normal pregnant women. Skinfold thickness and fat cell diameter were also measured. A model of body composition was formulated to permit the estimation of changes in fat, lean tissue and water content of the maternal body. Total maternal body fat increased during pregnancy, reaching a peak towards the end of the second trimester before diminishing. Serial measurements of fat cell diameter showed poor correlation, whilst total body fat calculated from skinfold thickness correlated well with our estimated values for total body fat in pregnancy.

Adipose Tissue↗
PubMed1979

Body composition in hypopituitary dwarfs before and during human growth hormone therapy.

The clinical characteristics and body composition of eight hypopituitary dwarfs (10.2-21.6 yr) were analyzed before and after 6 and 12 mo of growth hormone therapy. 2 IU 3 times/wk. Before treatment, growth rate was 1.8 +/- 0.7 cm/yr, height age was 2.0-12.8 yr less, and bone age 2.0-11.1 yr less than chronologic age. Total body water (TBW), lean body mass (LBM), extracellular water (ECW), and intracellular water (ICW) were below normal for chronologic age, but normal for height. Muscle mass (MM) was below normal for age and height. During HGH therapy, growth rate was 7.1 +/- 1.6 cm/yr in the first 6 mo and 7.8 +/- 1.4 cm/yr during the next 6 mo; the ratio of change in height age to change in chronologic age was greater than or equal to 1.0 in all patients and the ratio of change in bone age to change in height age was 1.2 in one patient and less than or equal to 1.0 in the others. TBW, LBM, ECW, and ICW increased according to height increments; however, MM increased at a faster rate than expected from the height gains. Also, a relative or absolute loss of total body fat was recorded during the first 6 mo of therapy. It is suggested (1) that among the body composition parameters studied, muscle mass is the tissue most closely reflecting the lack of HGH and also its therapeutic benefits and (2) evaluation of body composition in hypopituitary dwarfs in response to HGH therapy shows striking changes not reflected by the determination of stature or weight alone.

Adolescent↗
PubMed1979

A review of body composition studies with emphasis on total body water and fat.

Tritiated water meausres a volume 4 to 15% body weight larger than that by desiccation, and, at present, only 0.5 to 2.0% of the overestimation can be explained by the exchange of hydrogen of tritiated water with those of the proteins and carbohydrates of the body. The remainder of the error is unexplained. Water in the lumen of the gut is an appreciable percentage of total body water (TBW) in many mammalian species, with the pig and the human as possible exceptions, and it should be considered an integral part of TBW. Consequently, the exclusion or inclusion of this transcellular water as part of TBW significantly affects the final TBW volume. As tritiated water exchanges with water in the gut, a comparison of the data from the indirect method with the data from the direct method can only be made when water in the gut is included in the desiccation method. Conceptually, the amount of water in lean body mass is a reflection of the actively metabolizing cell mass of the body. However, water in the gut is outside this cell mass, and if included, it significantly overestimates the water associated with the lean body mass compartment. The percentage of water in fat-free wet weight for most mature animals is estimated at 73.2%, although the mean values in the literature range from 63% for the beagle to 80% for the mouse, with the mean for the majority of species between 70 and 76%. If the percentage of water in fat-free wet weight lies between 70 and 76% for most species, then the error in calculating fat using the figure 73.2% in the equation (% fat = 100 - % TBW/0.732) is significant. In the application of this equation, the largest potential error lies in the estimation of TBW with tritiated water.

Adipose Tissue↗
PubMed1977

The analysis of organic water pollutants by gas chromatography and gas chromatography-mass spectrometry.

Four methods for the analysis of trace levels or organic compounds in water have been discussed: direct aqueous injection, vapor stripping, solvent extraction, and lipophilic adsorption. Table 6 presents a comparison of these techniques. Direct injection is applicable to compounds having a wide range of polarities and volatilities, but it is not a very sensitive technique. For applications in which low sensitivity is acceptable, direct injection offers a very rapid and potentially accurate means of measuring organics in water. Vapor stripping is a factor of 10(6) more sensitive than direct injection, but this is achieved at the expense of simplicity. This method is applicable to compounds of volatilities less than that of eicosane. A subtle operational problem with most vapor stripping techniques is that the contents of the trap are consumed with one analysis; if anything goes awry, the analysis of that trapped sample cannot be repeated. Solvent extraction has a respectable sensitivity (about 0.5 ppb) and operationally it is very simple. Furthermore, aliquots of the resulting extract can be analyzed many times with different techniques if necessary. Because of the evaporation step, very volatile compounds (greater than that of decane) cannot be measured effectively with solvent extraction. The introduction of a solvent into the water carries with it the potential for contamination. Thus, ultrapure solvents must be used and all glassware should be carefully cleaned [96]. Lipophilic adsorption has the unique property of sampling many hundreds of liters of water. Thus, the method is quite sensitive (potentially in the ppt range) and, in addition, it can provide several milligrams of an isolated component. This latter feature is of considerable advantage if one wants to complement GC-MS analyses with infrared or NMR for difficult structural identifications. As a solvent extraction, the evaporation of the final solvent limits the applicability of adsorption methods to compounds with volatilities greater than that of decane. Finally, the importance of avoiding contamination should be emphasized. Many of the compounds encountered in environmental samples are also common laboratory artifacts, for example plasticizers and antioxidants. When one finds such compounds in a water sample, it is absolutely essential to demonstrate that they are indeed present in the water and are not the result of laboratory contamination. The best such demonstration is procedural blank analyses that are indeed blank.

Chromatography, Gas↗
PubMed1979

[Studies to investigate the ecological importance of the mass development of Hydrodictyon reticulatum in infiltration basins for drinking water. III. Identification of the active components by the use of spectroscopic methods and gas chromatography (author's transl)].

Antibacterial substances from H. reticulatum, that was harvested from its natural habitat or grown under culture conditions, could be isolated by extraction with ethanol or by steam destillation from cells as well as from culture filtrate. The active substances were tested by gas chromatography, infrared spectroscopy and mass spectrometry and characterized as a fraction of saturated fatty acids. Its composition seems to depend on external circumstances or culture conditions, respectively, because it differed from experiment to experiment even in samples, harvested at the same day. The most effective acids, active, however, only against grampositive strains are the long chain unsaturated ones with 16 or 18 C-atoms, as shown by bioassay detection (Fig. 3). The C16 = 3-acid was only found in the strain LB236-1b.

Anti-Bacterial Agents↗
PubMed1979

Regional extravascular lung water in normal sheep.

We measured the regional distribution of pulmonary extravascular water to test our prediction that, because of higher vascular hydrostatic pressure in more dependent zones, the bottom of the lung would tend to be wetter than the top. We injected eight normal sheep under halothane anesthesia with 125I-labeled albumin and killed them 5 min later. We suspended the sheep in the prone position and froze them solid in dry ice. We sawed the thorax into horizontal slices, chipped the frozen lung from each, and determined extravascular lung water and hematocrit. Hematocrit was calculated from separately measured red blood cell (tissue hemoglobin) and plasma (125I-albumin) masses. We found regional extravascular water was constant throughout the lung. Regional hematocrit was significantly higher at the lung base than at the apex in these slowly frozen sheep after death. Calculation of extravascular water using a single blood mass marker (hemoglobin) underestimated lung water, more so at the base than at the apex, because blood mass was overestimated. Accurate measurement of blood mass is critical in the calculation of regional lung water.

Albumins↗
PubMed1979

[Nutritional status in critically ill patients. Relationship with mortality (author's transl)].

Plasma proteins, triglyceridemia, body composition and delayed hypersensitivity were determined in 154 critically ill patients after admission. Plasma proteins levels were significantly increased in patients that were subsequently discharged vs. those that died: albumin: 33 +/- 6 g/l vs 28 +/- 6 g/l (p < 10(-6)); transferrin 2,18 +/- 0,65 g/l vs. 1,54 +/0 0,55 g/l (p < 10(-7)); prealbumin: 14,32 +/- 7,79 mg/100 ml vs. 7,28 +/-5,36 mg/100 ml (p < 10(-7)) and triglyceridemia was decreased: 1,07 +/- 0,38 g/l vs. 1,66 +/- 1,12 g/l (p not equal to 10(-3)). Body weight, fat weight and lead body mass were not correlated to subsequent mortality. Muscle cell mass was decreased (-17%, p < 10(-2)) and extracellular water was increased (+14%, p < 10(-4)), in patients who subsequently died. Total body water and visceral cell mass did not change. Initial anergy (tested with 3 antigens: candidin, tuberculin, varidase) did correlate with mortality: 35/62 died when delayed hypersensitivity was negative vs. 13/71 when it was positive (p < 10(-4)). Mortality was associated with decreased total lymphocyte count: 884 +/- 1025 vs. 1270 +/- 870 (p < 0,02) and serum iron: 51 +/- 40 micrograms/100 ml vs. 74 +/- 45 micrograms/100 ml (p < 10(-2)). Sepsis correlated with mortality (p < 10(-3)) and could produce these changes. These results suggest that critically ill paients have a protein-calorie malnutrition syndrom marktly different from that observed in simple starvation. Nutritional therapy must be, in this group of patients, adapted to this concept.

Adolescent↗
PubMed1979

Body water compartments with human aging using fat-free mass as the reference standard.

Forty-five healthy men and women aged 16-39 and 59-89 yr were studied for total body water (TBW) and extracellular water (ECW); intracellular water (ICW) was calculated as the difference (ICW = TBW - ECW). An independent measurement of total body fat by inert gas uptake provided a value (+/- 2%) for fat-free mass (FFB is wt minus body fat). Results agreed with observations by others that TBW and ICW are lower in the aged and lower in women, whether expressed as absolute volumes or per unit of weight, surface area, or height. However, with FFB as the reference standard very different aging trends appeared. TBW/FFB remained constant to our oldest measured subjects (704 +/- 7 ml/kg). ICW/FFB was slightly lower at advanced age, but the 4-5% decrease for each sex was within statistical variability. With age ECW increased slightly and its proportion within the fat-free body (ECW/FFB) was significantly higher. Based upon FFB, the distribution, proportions, and aging trends of body water compartments were similar for men, women, and male rats. Although its potential limitations must be appreciated, the FFB appears widely useful as a reference standard. The stability of ICW volume and of fat-free mass in aging man does not support the hypothesis that cellular mass is lost by healthy mammals with age.

Adipose Tissue↗
PubMed1979

Behavioral effects of strong 60-Hz electric fields in rats.

Eight individually housed male Long Evans rats were raised, beginning at age 30 days, for six weeks in an electric field exposure apparatus. During five of the six weeks, the animals were exposed to a 25 kV/m, 60-Hz electric field. A similar population of rats housed in an identical environment, except for the absence of the high voltage field, were used as control animals. Differences between the two groups in body mass, food and water intake, and exploratory activity were studied. Statistical analysis shows the high voltage fields to have no significant effects on the above parameters.

Animals↗