Hydrogen and oxygen stable isotope fractionation in body fluid compartments of dairy cattle according to season, farm, breed, and reproductive stage.

Environmental temperature affects water turnover and isotope fractionation by causing water evaporation from the body in mammals. This may lead to rearrangement of the water stable isotope equilibrium in body fluids. We propose an approach to detect possible variations in the isotope ratio in different body fluids on the basis of different homoeothermic adaptations in varying reproductive stages. Three different reproductive stages (pregnant heifer, primiparous lactating cow, and pluriparous lactating cow) of two dairy cattle breeds (Italian Friesian and Modenese) were studied in winter and summer. Blood plasma, urine, faecal water, and milk were sampled and the isotope ratios of H (2H/1H) and O (18O/16O) were determined. Deuterium excess and isotope-fractionation factors were calculated for each passage from plasma to faeces, urine and milk. The effects of the season, reproductive stages and breed on δ2H and δ18O were significant in all the fluids, with few exceptions. Deuterium excess was affected by season in all the analysed fluids. The correlations between water isotope measurements in bovine body fluids ranged between 0.6936 (urine-milk) and 0.7848 (urine-plasma) for δ2H, and between 0.8705 (urine-milk) and 0.9602 (plasma-milk) for δ18O. The increase in both isotopic δ values in all body fluids during summer is representative of a condition in which fractionation took place as a consequence of a different ratio between ingested and excreted water, which leads to an increased presence of the heavy isotopes. The different body water turnover between adult lactating cattle and non-lactating heifers was confirmed by the higher isotopic δ for the latter, with a shift in the isotopic equilibrium towards values more distant from those of drinking water.

Bioelectrical impedance analysis for assessment of fluid status and body composition in neonates--the good, the bad and the unknown.

BACKGROUND/OBJECTIVES: There is a critical need for improved technologies to monitor fluid balance and body composition in neonates, particularly those receiving intensive care. Bioelectrical impedance analysis meets many of the criteria required in this environment and appears to be effective for monitoring physiological trends. SUBJECT/METHODS: The literature regarding the use of bioelectrical impedance in neonates was reviewed. RESULTS: It was found that prediction equations for total body water, extracellular water and fat-free mass have been developed, but many require further testing and validation in larger cohorts. Alternative approaches based on Hanai mixture theory or vector analysis are in the early stages of investigation in neonates. CONCLUSIONS: Further research is required into electrode positioning, bioimpedance spectroscopy and Cole analysis in order to realise the full potential of this technology.

Manejo odontológico del paciente con enfermedad renal crónica terminal: revisión bibliográfica / Dental management of patients with chronic renal disease: a review

La enfermedad renal avanzada es la incapacidad de los riñones para excretar los productos de desecho del organismo, concentrar la orina y conservar los electrolitos, que trae como consecuencia manifestaciones sistémicas que provocan patologías bucales entre otras entidades. El objetivo de esta investigación es realizar una revisión bibliográfica destacando las manifestaciones bucales más importantes, el manejo y cuidados que debe tener el odontólogo al momento de atender a un paciente que presente este trastorno

Advanced renal disease is the inability of the kidneys to excrete waste products from the body, concentrate urine and conserve electrolytes, which results in systemic manifestations that cause oral pathologies among others. The objective of this research is to review literature highlighting the most important oral manifestations, management and care that should the dentist have when treating a patient with this disorder

Evaluation of bioimpedance spectroscopy for the measurement of body fluid compartment volumes in rats.

INTRODUCTION: Bioimpedance spectroscopy (BIS) has been used in human and large animal research to assess body fluid compartment volumes (BFC) such as total body water (TBW), extracellular fluid volume (ECFV), and intracellular fluid volume (ICFV). To date, the application of BIS for determination of BFC in small research animals has been limited. METHODS: We sought to evaluate the sensitivity and consistency of BIS for the determination of BFC in male SD rats. Thus, in separate series of experiments, we a) compared BFC values determined using BIS to BFC values obtained using radioisotope indicator dilution methods; b) examined day-to-day intra- and inter-rat BFC variability in small (267.8±5.4 g) and large (372.6±5.6 g) rats (n=8/group) as compared to empirical normative mammalian values; c) evaluated the sensitivity of BIS to detect time-dependent responses to repeated administration of a potent diuretic; and d) compared empirically generated BFC data to predicted osmotically-induced ECFV and ICFV shifts in response to i.v. administration of hypotonic (0.3%), isotonic (0.9%) or hypertonic (3.0%) saline (n=6/concentration). RESULTS: BFC values generated using radioisotope dilution agreed with those generated using BIS. BIS reliably detected differences between small and large rats (p<0.001), and was associated with low (<3.5%) day-to-day, intra-animal coefficient of variation (%=Standard Deviation/mean). BIS detected small reductions (~10%) in ECFV induced by as few as 2 days of the loop diuretic, furosemide, relative to vehicle treatment (70.8±1.5 ml vs. 84.0±1.5 ml; respectively, p<0.05). BIS rapidly detected shifts between ECFV and ICFV in response to osmotic saline challenge, and these responses were similar to physiologically predicted responses. DISCUSSION: The current studies support using BIS as a means of sensitively and reliably performing repeated measurements of BFC in rats of a) differing sizes, b) in response to therapeutic agents known to influence renal sodium handling and c) in response to osmotic challenge.

Estimation of salt intake by 24 h urinary sodium excretion in a representative sample of Spanish adults.

The present study reports the Na intake of a representative sample of Spanish young and middle-aged adults aged 18-60 years (n 418, 53·1 % women, selected from the capitals of fifteen provinces and the surrounding semi-urban/rural area), measured with a 24 h urinary Na excretion method. To validate the paper collection of 24 h urine, the correlation between fat-free mass determined by electrical bioimpedance (50·8 (sd 11·3) kg) and that determined via urinary creatinine excretion (51·5 (sd 18·8) kg) was calculated (r 0·633, P < 0·001). Urinary Na excretion correlated with systolic and dyastolic blood pressure data (r 0·243 and 0·153, respectively). Assuming that all urinary Na (168·0 (sd 78·6) mmol/d) comes from the diet, Na excretion would correspond with a dietary salt intake of 9·8 (sd 4·6) g/d, and it would mean that 88·2 % of the subjects had salt intakes above the recommended 5 g/d. Logistic regression analysis, adjusted for sex, age and BMI, showed male sex (OR 3·678, 95 % CI 2·336, 5·791) and increasing BMI (OR 1·069, 95 % CI 1·009, 1·132) (P < 0·001) to be associated with excreting >200 mmol/d urinary Na--a consequence of the higher salt intake in men and in participants with higher BMI. The present results help us to know the baseline salt intake in the Spanish young and middle-aged adult population, and can be used as the baseline to design policies to reduce salt consumption.