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Biomedical Papers of the Medical... Dec 2014The aim of this study is to compare markers of glomerular filtration rate (GFR), estimated GFR (eGFR), and metabolic parameters between admission and recovery in 13...
AIM
The aim of this study is to compare markers of glomerular filtration rate (GFR), estimated GFR (eGFR), and metabolic parameters between admission and recovery in 13 patients of Tomas Bata hospital with methanol poisoning during methanol problems in the Czech Republic in 2012. The impact of methanol concentration and age on metabolic parameters were discovered at the time of admission to hospital.
MATERIALS AND METHODS
The serum osmolality, methanol, ethanol, creatinine, cystatin C, Troponin I, ALT, plasma pH and lactate were measured in these 13 patients. The eGFR from serum creatinine (creatnine eGFR) and from cystatin C (cystatin C eGFR) were also determined.
RESULTS
Increased serum osmolality and markers of metabolic acidosis are key indirect laboratory findings in patients with methanol poisoning. There were no significant changes in eGFR in our patients between admission and recovery. Increased serum troponin I concentration was confirmed as an indicator of myocardial necrosis in four patients. Two patients developed acute kidney injury (AKI) before admission.
CONCLUSIONS
We found statistically significant differences in serum osmolality concentration, plasma pH and lactate between admission and recovery. We found no changes in eGFR between admission and recovery. One patient had vision problems due to damage to the occipital lobes. Methanol poisoning may cause increase in markers of cardiac damage.
Topics: Acute Kidney Injury; Adult; Aged; Biomarkers; Czech Republic; Female; Glomerular Filtration Rate; Hospitalization; Humans; Kidney; Kidney Function Tests; Male; Methanol; Middle Aged; Osmolar Concentration
PubMed: 24085314
DOI: 10.5507/bp.2013.074 -
Scientific Reports Jul 2017We evaluated the bactericidal activity of Bdellovibrio bacteriovorus, strain HD100, within blood sera against bacterial strains commonly associated with bacteremic...
We evaluated the bactericidal activity of Bdellovibrio bacteriovorus, strain HD100, within blood sera against bacterial strains commonly associated with bacteremic infections, including E. coli, Klebsiella pneumoniae and Salmonella enterica. Tests show that B. bacteriovorus HD100 is not susceptible to serum complement or its bactericidal activity. After a two hour exposure to human sera, the prey populations decreased 15- to 7,300-fold due to the serum complement activity while, in contrast, the B. bacteriovorus HD100 population showed a loss of only 33%. Dot blot analyses showed that this is not due to the absence of antibodies against this predator. Predation in human serum was inhibited, though, by both the osmolality and serum albumin. The activity of B. bacteriovorus HD100 showed a sharp transition between 200 and 250 mOsm/kg, and was progressively reduced as the osmolality increased. Serum albumin also acted to inhibit predation by binding to and coating the predatory cells. This was confirmed via dot blot analyses and confocal microscopy. The results from both the osmolality and serum albumin tests were incorporated into a numerical model describing bacterial predation of pathogens. In conclusion, both of these factors inhibit predation and, as such, they limit its effectiveness against pathogenic prey located within sera.
Topics: Bdellovibrio bacteriovorus; Complement System Proteins; Humans; Male; Microbial Viability; Osmolar Concentration; Serum Albumin
PubMed: 28725056
DOI: 10.1038/s41598-017-06272-2 -
International Journal of Sport... Sep 2023First morning urine (FMU) assessment would be a practical and convenient solution for clinically acceptable detection of underhydration prior to competition/training,...
First morning urine (FMU) assessment would be a practical and convenient solution for clinically acceptable detection of underhydration prior to competition/training, and for the general public. Thus, we thus sought to determine the diagnostic accuracy of FMU as a valid indicator of recent (previous 24 hr, 5 days average) hydration practices. For 5 consecutive days and one final morning, 67 healthy women (n = 38) and men (n = 29; age: 20 [1] years, body mass index: 25.9 [5.5]) completed 24-hr diet logs for total water intake (from beverages and foods, absolute and relative to body mass), 24-hr urine and FMU collection (last morning only) for osmolality (Osm), specific gravity (SG), and color (Col), and morning blood sampling for plasma osmolality and copeptin. Correlations determined significance and relationship strength among FMU and all other variables. Area under the receiver operating characteristic curves, sensitivity, specificity, and positive likelihood ratios were employed using previously reported values to indicate underhydration (total water intake < 30 ml/kg, osmolality > 500, and >800 mOsm/kg, specific gravity > 1.017, and copeptin > 6.93 pmol/L). FMU_Osm and FMU_SG were significantly correlated (p < .05) to all variables except the previous 5-day plasma osmolality. FMU_Col was only significantly correlated with other color time intervals and total water intake per gram. FMU_Osm held greatest utility (area under the receiver operating characteristic curve, sensitivity, and specificity >80%) overall, with the best outcome being FMU_Osm indicating a previous 24-hr osmolality threshold of 500 mOsm/kg (FMU_Osm criterion >710 mOsm/kg and positive likelihood ratio = 5.9). With less effort and cost restriction, FMU is a viable metric to assess underhydration.
Topics: Male; Humans; Adult; Female; Young Adult; Urinalysis; Drinking; Osmolar Concentration; Body Mass Index; Specific Gravity; Dehydration; Urine
PubMed: 37225169
DOI: 10.1123/ijsnem.2022-0203 -
Biomolecules Jun 2022Interactions between physical forces and membrane proteins underpin many forms of environmental sensation and acclimation. Microbes survive osmotic stresses with the...
Interactions between physical forces and membrane proteins underpin many forms of environmental sensation and acclimation. Microbes survive osmotic stresses with the help of mechanically gated ion channels and osmolyte transporters. Plant mechanosensitive ion channels have been shown to function in defense signaling. Here, we engineered genetically encoded osmolality sensors (OzTracs) by fusing fluorescent protein spectral variants to the mechanosensitive ion channels MscL from or MSL10 from . When expressed in yeast cells, the OzTrac sensors reported osmolality changes as a proportional change in the emission ratio of the two fluorescent protein domains. Live-cell imaging revealed an accumulation of fluorescent sensors in internal aggregates, presumably derived from the endomembrane system. Thus, OzTrac sensors serve as osmolality-dependent reporters through an indirect mechanism, such as effects on molecular crowding or fluorophore solvation.
Topics: Arabidopsis; Arabidopsis Proteins; Escherichia coli; Escherichia coli Proteins; Ion Channels; Membrane Proteins; Osmolar Concentration; Osmotic Pressure
PubMed: 35740912
DOI: 10.3390/biom12060787 -
ELife Sep 2021Water balance, tracked by extracellular osmolality, is regulated by feedback and feedforward mechanisms. Feedback regulation is reactive, occurring as deviations in...
Water balance, tracked by extracellular osmolality, is regulated by feedback and feedforward mechanisms. Feedback regulation is reactive, occurring as deviations in osmolality are . Feedforward or presystemic regulation is proactive, occurring when disturbances in osmolality are . Vasopressin (AVP) is a key hormone regulating water balance and is released during hyperosmolality to limit renal water excretion. AVP neurons are under feedback and feedforward regulation. Not only do they respond to disturbances in blood osmolality, but they are also rapidly suppressed and stimulated, respectively, by drinking and eating, which will ultimately decrease and increase osmolality. Here, we demonstrate that AVP neuron activity is regulated by multiple anatomically and functionally distinct neural circuits. Notably, presystemic regulation during drinking and eating are mediated by non-overlapping circuits that involve the lamina terminalis and hypothalamic arcuate nucleus, respectively. These findings reveal neural mechanisms that support differential regulation of AVP release by diverse behavioral and physiological stimuli.
Topics: Animals; Arginine Vasopressin; Female; Hypothalamus; Male; Mice; Neurons; Osmolar Concentration; Osmotic Pressure; Vasopressins; Water-Electrolyte Balance
PubMed: 34585668
DOI: 10.7554/eLife.66609 -
Journal of Cellular Biochemistry Feb 2010Osmotic stress is a potent regulator of the normal function of cells that are exposed to osmotically active environments under physiologic or pathologic conditions. The... (Review)
Review
Osmotic stress is a potent regulator of the normal function of cells that are exposed to osmotically active environments under physiologic or pathologic conditions. The ability of cells to alter gene expression and metabolic activity in response to changes in the osmotic environment provides an additional regulatory mechanism for a diverse array of tissues and organs in the human body. In addition to the activation of various osmotically- or volume-activated ion channels, osmotic stress may also act on the genome via a direct biophysical pathway. Changes in extracellular osmolality alter cell volume, and therefore, the concentration of intracellular macromolecules. In turn, intracellular macromolecule concentration is a key physical parameter affecting the spatial organization and pressurization of the nucleus. Hyper-osmotic stress shrinks the nucleus and causes it to assume a convoluted shape, whereas hypo-osmotic stress swells the nucleus to a size that is limited by stretch of the nuclear lamina and induces a smooth, round shape of the nucleus. These behaviors are consistent with a model of the nucleus as a charged core/shell structure pressurized by uneven partition of macromolecules between the nucleoplasm and the cytoplasm. These osmotically-induced alterations in the internal structure and arrangement of chromatin, as well as potential changes in the nuclear membrane and pores are hypothesized to influence gene transcription and/or nucleocytoplasmic transport. A further understanding of the biophysical and biochemical mechanisms involved in these processes would have important ramifications for a range of fields including differentiation, migration, mechanotransduction, DNA repair, and tumorigenesis.
Topics: Animals; Cell Nucleus; Humans; Osmolar Concentration; Osmosis; Osmotic Pressure; Signal Transduction
PubMed: 20024954
DOI: 10.1002/jcb.22437 -
Kidney International Nov 1985The effect of regular dialysis and isolated ultrafiltration on plasma osmolality, plasma colloid osmotic pressure (COP), plasma volume, and vascular refilling rate was... (Clinical Trial)
Clinical Trial
The effect of regular dialysis and isolated ultrafiltration on plasma osmolality, plasma colloid osmotic pressure (COP), plasma volume, and vascular refilling rate was evaluated in maintenance dialysis patients. Nineteen patients underwent regular dialysis and 11 isolated ultrafiltration. Blood samples from these subjects were obtained from arterial or venous dialysis system ports and peripheral veins. For any decrease in plasma volume, there was an increment in COP with each procedure in both venous and arterial ports and the presence of a progressive decrease of plasma osmolality was observed only during regular dialysis. Second, five additional patients underwent 2 hrs of regular dialysis and isolated ultrafiltration in separate sessions removing comparable amounts of fluid (approximately 2.5 liter); after 2 hrs, there were no differences in the changes of plasma volume and COP, but again plasma osmolality decreased only during regular dialysis. These studies demonstrate that moderate changes in plasma osmolality do not affect COP. Furthermore, the ability of the plasma to recruit fluid and generate vascular refilling (as assessed by COP) is similar during regular dialysis and isolated ultrafiltration, provided the rates of ultrafiltration are the same.
Topics: Adult; Blood; Blood Proteins; Blood Vessels; Humans; Middle Aged; Osmolar Concentration; Osmotic Pressure; Plasma Volume; Renal Dialysis; Ultrafiltration
PubMed: 4087695
DOI: 10.1038/ki.1985.202 -
European Journal of Pharmaceutical... May 2022It was recently shown that osmolality-dependent fluid movement is a significant factor causing the clinically observed apple juice (AJ)-atenolol interaction. Here we...
It was recently shown that osmolality-dependent fluid movement is a significant factor causing the clinically observed apple juice (AJ)-atenolol interaction. Here we examined whether osmolality-dependent fluid movement may also explain the AJ volume dependence of the AJ-atenolol interaction. In Wistar rats, the luminal fluid volume after administration of different volumes of purified water (0.5 and 1.0 mL) gradually reduced to a similar steady-state level, while that after administration of different volumes of AJ (0.5 and 1.0 mL) increased and attained different apparent steady-state levels. It was hypothesized that osmolality-dependent fluid secretion would account for the volume dependence of the apparent steady-state. Indeed, the luminal concentration of FD-4, a non-permeable compound, after administration in AJ was attenuated depending upon the ingested volume, whereas that after administration in purified water was independent of the ingested fluid volume. An in vivo pharmacokinetic study in rats showed that co-administration of AJ and hyperosmotic solution (adjusted to the osmolality of AJ) with atenolol volume-dependently reduced the AUC and C of atenolol significantly. These results show that osmolality-dependent variations in luminal fluid volume may indirectly influence the absorption characteristics of drugs, and can account for the observed volume dependence of beverage-drug interactions.
Topics: Animals; Beverages; Drug Interactions; Intestinal Absorption; Osmolar Concentration; Pharmaceutical Preparations; Rats; Rats, Wistar
PubMed: 35121020
DOI: 10.1016/j.ejps.2022.106136 -
The British Journal of Nutrition Apr 2024The weight, urine colour and thirst (WUT) Venn diagram is a practical hydration assessment tool; however, it has only been investigated during first-morning. This study...
The weight, urine colour and thirst Venn diagram is an accurate tool compared with urinary and blood markers for hydration assessment at morning and afternoon timepoints in euhydrated and free-living individuals.
The weight, urine colour and thirst (WUT) Venn diagram is a practical hydration assessment tool; however, it has only been investigated during first-morning. This study investigated accuracy of the WUT Venn diagram at morning and afternoon timepoints compared with blood and urine markers. Twelve men (21 ± 2 years; 81·0 ± 15·9 kg) and twelve women (22 ± 3 years; 68·8 ± 15·2 kg) completed the study. Body mass, urine colour, urine specific gravity (USG), urine osmolality (U), thirst and plasma osmolality (P) were collected at first-morning and afternoon for 3 consecutive days in free-living (FL) and euhydrated states. Number of markers indicating dehydration levels were categorised into either 3, 2, 1 or 0 WUT markers. Receiver operating characteristics analysis calculated the sensitivity and specificity of 1, 2 or 3 hydration markers in detecting dehydration or euhydration. Specificity values across morning and afternoon exhibited high diagnostic accuracy for USG (0·890-1·000), U (0·869-1·000) and P (0·787-0·990) when 2 and 3 WUT markers were met. Sensitivity values across both timepoints exhibited high diagnostic accuracy for USG (0·826-0·941) and U (0·826-0·941), but not P in the afternoon (0·324) when 0 and 1 WUT markers were met. The WUT Venn diagram is accurate in detecting dehydration for WUT2 and WUT3 based off USG, U and P during first-morning and afternoon. Applied medical, sport and occupational practitioners can use this tool in field settings for hydration assessment not only at various timepoints throughout the day but also in FL individuals.
Topics: Male; Humans; Female; Dehydration; Thirst; Color; Osmolar Concentration; Urinalysis; Urine
PubMed: 38012859
DOI: 10.1017/S000711452300274X -
Kidney International Nov 2005The role of osmolality of contrast media (CM) in the pathogenesis of contrast-induced nephropathy (CIN) has been suggested by studies comparing high osmolality CM (>1500... (Review)
Review
BACKGROUND
The role of osmolality of contrast media (CM) in the pathogenesis of contrast-induced nephropathy (CIN) has been suggested by studies comparing high osmolality CM (>1500 mOsm/kg) with low-osmolality CM (550-850 mOsm/kg), and by the results of a recent comparison of a CM isotonic to plasma (iodixanol, 290 mOsm/kg) with a low-osmolality CM (iohexol, 844 mOsm/kg) in high-risk patients undergoing cardiac or peripheral angiography.
METHODS
Using prospectively defined search criteria, we performed a systematic overview of prospective, randomized, controlled studies of CIN in renally impaired patients receiving intra-arterial doses of iodixanol or low-osmolality, nonionic CM, and conducted a systematic review of the data from those studies to determine whether the osmolality of CM was predictive of CIN incidence.
RESULTS
Seventeen primary studies met the selection criteria, for a total of 1365 patients. Overall, the incidence of CIN was 16.8%. A multivariate logistic regression model showed that the risk of CIN is similar with the iso-osmolality iodixanol and the low-osmolality iopamidol (796 mOsm/kg). The risk of CIN was significantly lower with iodixanol and iopamidol compared to iohexol. The incidence of CIN with iohexol was also significantly higher than with iopamidol, despite their similar osmolalities.
CONCLUSION
These data suggest that factors other than osmolality play a significant role in the pathogenesis of CIN, at least for agents with osmolalities of 800 mOsm/kg or less.
Topics: Acute Kidney Injury; Contrast Media; Humans; Incidence; Iohexol; Kidney Failure, Chronic; Osmolar Concentration; Risk Factors; Triiodobenzoic Acids
PubMed: 16221227
DOI: 10.1111/j.1523-1755.2005.00684.x