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Internal Medicine (Tokyo, Japan) Feb 1997
Topics: Acute Kidney Injury; Alcohol Drinking; Anti-Inflammatory Agents, Non-Steroidal; Dehydration; Ethanol; Humans
PubMed: 9099586
DOI: 10.2169/internalmedicine.36.80 -
Journal of Applied Physiology... Sep 2011The purpose of this study was to determine whether the reduction in stroke volume (SV), previously shown to occur with dehydration and increases in internal body...
The purpose of this study was to determine whether the reduction in stroke volume (SV), previously shown to occur with dehydration and increases in internal body temperatures during prolonged exercise, is caused by a reduction in left ventricular (LV) function, as indicated by LV volumes, strain, and twist ("LV mechanics"). Eight healthy men [age: 20 ± 2, maximal oxygen uptake (VO₂max): 58 ± 7 ml·kg⁻¹·min⁻¹] completed two, 1-h bouts of cycling in the heat (35°C, 50% peak power) without fluid replacement, resulting in 2% and 3.5% dehydration, respectively. Conventional and two-dimensional speckle-tracking echocardiography was used to determine LV volumes, strain, and twist at rest and during one-legged knee-extensor exercise at baseline, both levels of dehydration, and following rehydration. Progressive dehydration caused a significant reduction in end-diastolic volume (EDV) and SV at rest and during one-legged knee-extensor exercise (rest: Δ-33 ± 14 and Δ-21 ± 14 ml, respectively; exercise: Δ-30 ± 10 and Δ-22 ± 9 ml, respectively, during 3.5% dehydration). In contrast to the marked decline in EDV and SV, systolic and diastolic LV mechanics were either maintained or even enhanced with dehydration at rest and during knee-extensor exercise. We conclude that dehydration-induced reductions in SV at rest and during exercise are the result of reduced LV filling, as reflected by the decline in EDV. The concomitant maintenance of LV mechanics suggests that the decrease in LV filling, and consequently ejection, is likely caused by the reduction in blood volume and/or diminished filling time rather than impaired LV function.
Topics: Adolescent; Analysis of Variance; Bicycling; Biomechanical Phenomena; Body Temperature Regulation; Dehydration; Drinking; Echocardiography, Doppler, Pulsed; Exercise; Hemodynamics; Humans; Male; Rotation; Stroke Volume; Time Factors; Ventricular Function, Left; Young Adult
PubMed: 21700893
DOI: 10.1152/japplphysiol.00528.2011 -
Journal of Dairy Science Sep 2005We studied the influence of short-term changes in water intake in 4 lactating Holstein cows on diurnal fluctuation of packed cell volume (PCV), freezing point of blood...
We studied the influence of short-term changes in water intake in 4 lactating Holstein cows on diurnal fluctuation of packed cell volume (PCV), freezing point of blood (FPblood), freezing point of milk (FPmilk), and the relationship between changes in FPblood and FPmilk. The experiment lasted 108 h and was divided into 3 periods: 1) control (38 h); 2) dehydration/rehydration with 4 consecutive 12-h sequences: 8 h without water, 0.5-h access to water, 1.5 h without water, and 2-h access to water; and (3) 22 h for reconstitution. Cows were milked at 12-h intervals. Blood was sampled from the jugular vein hourly throughout the experiment, and at 0, 15, 30, 60, 90, 120, 150, 180, 210, and 240 min after initiated rehydration following the 8-h dehydration sequences. Intakes of free water and water in feed were recorded every hour. The PCV was negatively affected by water intake within the hour before sampling. Dehydration lowered FPblood steadily, whereas FPblood increased by 0.024 degrees C within 30 min following a large water intake in the rehydration period. The FPblood was not significantly influenced by actual water intake, but was highly correlated with the available water pool at time of blood sampling. The FPmilk correlated positively with the FPblood collected 1 h before milk sampling, indicating a delay in the transfer of water from plasma to milk. In summary, FPblood and FPmilk decrease during dehydration and increase during rehydration. Rehydration following a long dehydration period caused an increase in FPmilk within 1 h, but not above the initial level for FPmilk of the cow.
Topics: Animals; Blood; Cattle; Cattle Diseases; Circadian Rhythm; Dehydration; Diet; Drinking; Female; Fluid Therapy; Hematocrit; Lactation; Milk; Osmolar Concentration; Time Factors; Transition Temperature
PubMed: 16107408
DOI: 10.3168/jds.S0022-0302(05)73001-0 -
International Journal of Molecular... Jun 2023Drought is among the most challenging environmental restrictions to tomatoes (Solanum lycopersi-cum), which causes dehydration of the tissues and results in massive loss...
Drought is among the most challenging environmental restrictions to tomatoes (Solanum lycopersi-cum), which causes dehydration of the tissues and results in massive loss of yield. Breeding for dehydration-tolerant tomatoes is a pressing issue as a result of global climate change that leads to increased duration and frequency of droughts. However, the key genes involved in dehydration response and tolerance in tomato are not widely known, and genes that can be targeted for dehydration-tolerant tomato breeding remains to be discovered. Here, we compared phenotypes and transcriptomic profiles of tomato leaves between control and dehydration conditions. We show that dehydration decreased the relative water content of tomato leaves after 2 h of dehydration treatment; however, it promoted the malondialdehyde (MDA) content and ion leakage ratio after 4 h and 12 h of dehydration, respectively. Moreover, dehydration stress triggered oxidative stress as we detected significant increases in HO and O levels. Simultaneously, dehydration enhanced the activities of antioxidant enzymes including peroxidase (POD), superoxide dismutase (SOD), catalase (CAT), and phenylalanine ammonia-lyase (PAL). Genome-wide RNA sequencing of tomato leaves treated with or without dehydration (control) identified 8116 and 5670 differentially expressed genes (DEGs) after 2 h and 4 h of dehydration, respectively. These DEGs included genes involved in translation, photosynthesis, stress response, and cytoplasmic translation. We then focused specifically on DEGs annotated as transcription factors (TFs). RNA-seq analysis identified 742 TFs as DEGs by comparing samples dehydrated for 2 h with 0 h control, while among all the DEGs detected after 4 h of dehydration, only 499 of them were TFs. Furthermore, we performed real-time quantitative PCR analyses and validated expression patterns of 31 differentially expressed TFs of NAC, AP2/ERF, MYB, bHLH, bZIP, WRKY, and HB families. In addition, the transcriptomic data revealed that expression levels of six drought-responsive marker genes were upregulated by de-hydration treatment. Collectively, our findings not only provide a solid foundation for further functional characterization of dehydration-responsive TFs in tomatoes but may also benefit the improvement of dehydration/drought tolerance in tomatoes in the future.
Topics: Transcription Factors; Transcriptome; Solanum lycopersicum; Dehydration; Hydrogen Peroxide; Gene Expression Profiling; Plant Leaves; Gene Expression Regulation, Plant; Stress, Physiological; Droughts; Plant Proteins
PubMed: 37298675
DOI: 10.3390/ijms24119725 -
Plant Physiology Jan 2022Dehydration damages the structural integrity of the chloroplast membrane and, consequently, the normal photosynthetic function of this organelle. Remodeling of...
Dehydration damages the structural integrity of the chloroplast membrane and, consequently, the normal photosynthetic function of this organelle. Remodeling of galactolipids by converting monogalactosyl-diacylglycerol (MGDG) to digalactosyl-diacylglycerol (DGDG) and oligo-galactolipids is an effective adaptation strategy for protecting against dehydration damage to the chloroplast membrane. However, detailed molecular mechanisms are missing. In this study, by performing molecular-level simulations of bi-lamellar membranes under various dehydration conditions, we find that MGDG-to-DGDG remodeling protects the chloroplast membrane in a unique manner by simultaneously dictating both the extent and the pattern of fusion stalks formed with the apposed membrane. Specifically, MGDG-rich membranes form elongated stalks at a moderate dehydration level, whereas DGDG-rich membranes form smaller, rounded stalks. Simulations of wild-type and mutant Arabidopsis (Arabidopsis thaliana) outer chloroplast membranes further confirm that the mutant membrane without galactolipid remodeling is more susceptible to membrane fusion due to its higher MGDG content. Our work reveals the underlying physical mechanisms that govern the pattern and extent of membrane fusion structures, paving the way for rational genetic engineering of crops with improved dehydration tolerance.
Topics: Chloroplasts; Dehydration; Membrane Fusion; Membrane Lipids; Plant Physiological Phenomena
PubMed: 34730798
DOI: 10.1093/plphys/kiab512 -
BMJ Open Jun 2021To examine the prevalence of dehydration without diarrhoea among admitted children aged 1-59 months and to describe fluid management practices in such cases. (Observational Study)
Observational Study
OBJECTIVES
To examine the prevalence of dehydration without diarrhoea among admitted children aged 1-59 months and to describe fluid management practices in such cases.
DESIGN
A multisite observational study that used routine in-patient data collected prospectively between October 2013 and December 2018.
SETTINGS
Study conducted in 13 county referral hospitals in Kenya.
PARTICIPANTS
Children aged 1-59 months with admission or discharge diagnosis of dehydration but had no diarrhoea as a symptom or diagnosis. Children aged <28 days and those with severe acute malnutrition were excluded.
RESULTS
The prevalence of dehydration in children without diarrhoea was 3.0% (2019/68 204) and comprised 15.9% (2019/12 702) of all dehydration cases. Only 55.8% (1127/2019) of affected children received either oral or intravenous fluid therapy. Where fluid treatment was given, the volumes, type of fluid, duration of fluid therapy and route of administration were similar to those used in the treatment of dehydration secondary to diarrhoea. Pneumonia (1021/2019, 50.6%) and malaria (715/2019, 35.4%) were the two most common comorbid diagnoses. Overall case fatality in the study population was 12.9% (260/2019).
CONCLUSION
Sixteen per cent of children hospitalised with dehydration do not have diarrhoea but other common illnesses. Two-fifths do not receive fluid therapy; a regimen similar to that used in diarrhoeal cases is used in cases where fluid is administered. Efforts to promote compliance with guidance in routine clinical settings should recognise special circumstances where guidelines do not apply, and further studies on appropriate management for dehydration in the absence of diarrhoea are required.
Topics: Child; Dehydration; Diarrhea; Fluid Therapy; Hospitals; Humans; Infant; Kenya; Prevalence
PubMed: 34145005
DOI: 10.1136/bmjopen-2020-042079 -
Revue Medicale de Liege Nov 2014The stratum corneum materializes the interface between the body and its environment. Such a structure is influenced by the climate and seasons. A series of... (Review)
Review
The stratum corneum materializes the interface between the body and its environment. Such a structure is influenced by the climate and seasons. A series of physicochemical parameters are involved in this relationship. Among them, the relative humidity, the dew point, the insensible loss of water and the concepts of water-as-ice and the higgledy-piggledy-water.
Topics: Antimony; Atmosphere; Climate Change; Dehydration; Humans; Skin Diseases; Skin Physiological Phenomena; Water
PubMed: 25796775
DOI: No ID Found -
PloS One 2024Pressure ulcers and dehydration are common conditions among residents of long-term care facilities that result in negative health effects. They have been associated with...
Pressure ulcers and dehydration are common conditions among residents of long-term care facilities that result in negative health effects. They have been associated with signs of neglect and increased 30-day mortality among LTC residents. However, they are both preventable and with proper care can be effectively managed and treated. We conducted a retrospective cohort study to examine factors associated with pressure ulcers and dehydration among long-term care residents in the province of Ontario, Canada. Results indicated that close to one-fifth of residents were dehydrated (17.3%) or had a pressure ulcer (18.9%) during the study period. Advanced age was significantly associated with the presence of pressure ulcers and dehydration for both men and women. However, men were more likely to present with a pressure ulcer while women were more likely to exhibit symptoms of dehydration. Study findings also demonstrate the presence of both conditions being higher in municipal and not-for-profit homes compared to for-profit homes. The significant differences observed in relation to home ownership which require further investigation to identify the most relevant factors in explaining these differences. Overall, pressure ulcers and dehydration are preventable conditions that warrant attention from policymakers to ensure quality of care and resident safety are prioritized.
Topics: Male; Humans; Female; Long-Term Care; Ontario; Pressure Ulcer; Retrospective Studies; Dehydration
PubMed: 38295099
DOI: 10.1371/journal.pone.0297588 -
American Journal of Physiology.... Mar 2020Maintenance of the volume and osmolality of body fluids is important, and the adaptive responses recruited to protect against osmotic stress are crucial for survival....
Maintenance of the volume and osmolality of body fluids is important, and the adaptive responses recruited to protect against osmotic stress are crucial for survival. The objective of this work was to compare the responses that occur in aging male and female rats during water deprivation. For this purpose, groups of male and female Wistar rats aged 3 mo (adults) or 18 mo (old) were submitted to water deprivation (WD) for 48 h. The water and sodium (0.15 M NaCl) intake, plasma concentrations of oxytocin (OT), arginine vasopressin (AVP), corticosterone (CORT), atrial natriuretic peptide (ANP), and angiotensin II (ANG II) were determined in hydrated and water-deprived animals. In response to WD, old male and female rats drank less water and saline than adults, and both adult and old females drank more water and saline than respective males. Dehydrated old animals displayed lower ANG II plasma concentration and CORT response compared with the respective normohydrated rats. Dehydrated adult males had higher plasma ANP and AVP as well as lower CORT concentrations than dehydrated adult females. Moreover, plasma OT and CORT levels of old female rats were higher than those in the dehydrated old male rats. Relative expression of ANG II type 1 receptor mRNA was decreased in the subfornical organ of adult and old male rats as well as adult female rats in response to WD. In conclusion, the study elucidated the effect of sex and age on responses induced by WD, altering the degree of dehydration induced by 48 h of WD.
Topics: Age Factors; Animals; Arginine Vasopressin; Behavior, Animal; Dehydration; Drinking; Female; Male; Rats, Wistar; Sex Factors; Sodium Chloride; Subfornical Organ; Water Deprivation
PubMed: 31967852
DOI: 10.1152/ajpregu.00303.2019 -
The Cochrane Database of Systematic... Jul 2006Dehydration associated with gastroenteritis is a serious complication. Oral rehydration is an effective and inexpensive treatment, but some physicians prefer intravenous... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Dehydration associated with gastroenteritis is a serious complication. Oral rehydration is an effective and inexpensive treatment, but some physicians prefer intravenous methods.
OBJECTIVES
To compare oral with intravenous therapy for treating dehydration due to acute gastroenteritis in children.
SEARCH STRATEGY
We searched the Cochrane Infectious Diseases Group Specialized Register (March 2006), CENTRAL (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to March 2006), EMBASE (1974 to March 2006), LILACS (1982 to March 2006), and reference lists. We also contacted researchers, pharmaceutical companies, and relevant organizations.
SELECTION CRITERIA
Randomized and quasi-randomized controlled trials comparing intravenous rehydration therapy (IVT) with oral rehydration therapy (ORT) in children up to 18 years of age with acute gastroenteritis.
DATA COLLECTION AND ANALYSIS
Two authors independently extracted data and assessed quality using the Jadad score. We expressed dichotomous data as a risk difference (RD) and number needed to treat (NNT), and continuous data as a weighted mean difference (WMD). We used meta-regression for subgroup analyses.
MAIN RESULTS
Seventeen trials (1811 participants), of poor to moderate quality, were included. There were more treatment failures with ORT (RD 4%, 95% confidence interval (CI) 1 to 7, random-effects model; 1811 participants, 18 trials; NNT = 25). Six deaths occurred in the IVT group and two in the ORT groups (4 trials). There were no significant differences in weight gain (369 participants, 6 trials), hyponatremia (248 participants, 2 trials) or hypernatremia (1062 participants, 10 trials), duration of diarrhea (960 participants, 8 trials), or total fluid intake at six hours (985 participants, 8 trials) and 24 hours (835 participants, 7 trials). Shorter hospital stays were reported for the ORT group (WMD -1.20 days, 95% CI -2.38 to -0.02 days; 526 participants, 6 trials). Phlebitis occurred more often in the IVT group (NNT 50, 95% CI 25 to 100) and paralytic ileus more often in the ORT group (NNT 33, 95% CI 20 to 100, fixed-effect model), but there was no significant difference between ORT using the low osmolarity solutions recommended by the World Health Organization and IVT (729 participants, 6 trials).
AUTHORS' CONCLUSIONS
Although no clinically important differences between ORT and IVT, the ORT group did have a higher risk of paralytic ileus, and the IVT group was exposed to risks of intravenous therapy. For every 25 children (95% CI 14 to 100) treated with ORT one would fail and require IVT.
Topics: Administration, Oral; Child; Dehydration; Fluid Therapy; Gastroenteritis; Humans; Infusions, Intravenous; Randomized Controlled Trials as Topic; Rehydration Solutions
PubMed: 16856044
DOI: 10.1002/14651858.CD004390.pub2