Sleep quality in chronic kidney patients: a systematic review

The maintenance of sleep quality improves an individual’s quality of life and reduces the risk of death associated with disease, such as chronic kidney disease (CKD) (progressive and irreversible loss of kidney function). Poor sleep quality can negatively affect immunity, cognitive functions, and emotional manifestations. CKD patients have poor sleep quality in approximately 80% of cases. A systematic literature review was undertaken using online data bases. 73,734 studies were found, 21 of which met our inclusion criteria and were subject to detailed analysis. Although renal transplantation appears to be promising with regard to improving the quality of sleep of kidney patients, there is still a high prevalence of poor sleep even after the operation. Longitudinal studies are needed to understand better the risk factors that are involved and to indicate possible treatments that may improve the overall quality of life in this section of the population.     

The quality of the aquatic environment and macrophytes of karstic watercourses

The quality of the aquatic environment and macrophytes were surveyed in the case of the remarkable karstic river Ljubljanica s. lat. (Slovenia). It consists of seven intermittent and permanent surface watercourses, connected by groundwater flows. We assessed 11 parameters describing the land use beyond the riparian zone, the structure of the riparian zone and stream channel morphology, as well as the distribution and abundance of macrophytes. The intermittent watercourses exhibited a relatively high level of naturalness, because the variable water regime prevents intensive human activity. Greater influence of the human activity on the permanent watercourses resulted in a modified riverine environment. The share of different ecological groups of macrophytes, i.e. submerged, emerged and amphibious species, reflected the water regimes of the different watercourses. A total of 62 taxa of macrophytes were identified in about 100 km of length examined. Of these, amphibious macrophytes dominated as a consequence of intermittent water regime. The relationship between environmental parameters and macrophytes, and the effects of the intermittent hydrology were investigated. All environmental parameters explained 28% of the variance in the distribution of macrophytes in watercourses, as determined by canonical correspondence analysis. Completeness of the riparian zone, bank undercutting and sediment accumulation were found to be the most influential.     

Resting metabolic rate and its adjustments as predictors of risk protein-energy wasting in hemodialysis patients

Background: The purpose of the present study was to explore the association between resting metabolic rate (RMR) and protein-energy wasting (PEW) risk in Chinese hemodialysis patients by age and gender subgroup.Methods: RMR and body composition (body cell mass (BCM) and fat mass) of 774 patients undergoing hemodialysis were estimated by bio-electrical impedance analysis (BIA). Anthropometric data were collected by a standard measurement protocol, and the upper arm muscle circumference (AMC) was calculated. Biochemical nutritional and dialysis parameters were obtained. Linear regression analysis was used to analyze the relationship among RMR, body composition and nutritional factors.Results: The mean age was 54.96 ± 15.78 years. RMR level in patients was 1463.0 (1240.5, 1669.0) kcal/d. In multiple linear regression models, BCM, left calf circumference (LCC), fat mass were the determinants association with RMR (P<0.001). Among the patients in the sample, 133 (17.2%) had been diagnosed with PEW per International Society of Renal Nutrition and Metabolism (ISRNM) criteria and 363 (46.9%) were being at risk PEW. The area under the receiver-operating characteristic curve (AUC) of RMR for predicting risk PEW was greater than RMR/BCM and RMR/body surface area (BSA). When the cutoff of RMR was 1481 kcal/d it had the higher sensitivity and specificity (82 and 42%), and the AUC was 0.68 in elderly maintenance hemodialysis (MHD) patients (P<0.001). After adjustment for potential confounders, lowest RMR quartile level (<1239) increased the risk of PEW (OR = 4.71, 95% CI: 1.33–16.64, P=0.016) in all patients.Conclusions: Older patients with PEW have a lower RMR reduction. RMR and RMR/BCM may play the role in objective screening to detect risk PEW in MHD patients, especially in males.     

Raman spectroscopy of human skin for kidney failure detection

The object of this paper is in vivo study of skin spectral-characteristics in patients with kidney failure by conventional Raman spectroscopy in near infrared region. The experimental dataset was subjected to discriminant analysis with the projection on latent structures (PLS-DA). Application of Raman spectroscopy to investigate the forearm skin in 85 adult patients with kidney failure (90 spectra) and 40 healthy adult volunteers (80 spectra) has yielded the accuracy of 0.96, sensitivity of 0.94 and specificity of 0.99 in terms of identifying the target subjects with kidney failure. The autofluorescence analysis in the near infrared region identified the patients with kidney failure among healthy volunteers of the same age group with specificity, sensitivity, and accuracy of 0.91, 0.84, and 0.88, respectively. When classifying subjects by the presence of kidney failure using the PLS-DA method, the most informative Raman spectral bands are 1315 to 1330, 1450 to 1460, 1700 to 1800 cm⁻¹. In general, the performed study demonstrates that for in vivo skin analysis, the conventional Raman spectroscopy can provide the basis for cost-effective and accurate detection of kidney failure and associated metabolic changes in the skin.     

Comaprative binding study of aluminum and chromium to human transferrin

The characteristics of aluminum and chromium binding to apotransferrin (apo-tf) have been investigated and compared. Both metal ions were taken up by human transferrin forming complexes with the maximum absorbances at 405 nm for chromium-transferrin (cr-tf) and 240 nm for aluminum-transferrin (Al-tf). In the presence of citric acid, chromium binding to transferrin is five times more than aluminum. The binding of aluminum or chromium to apo-transferrin was reduced by 18 and 22% in the presence of 200 ng/mL of iron. The binding of both metals to apo-tf appears to be pH dependent. In acidic pHs, less chromium and more aluminum binding occurred.     

Effect of creatine supplementation during rapid body mass reduction on metabolism and isokinetic muscle performance capacity

Well-trained subjects (n=6) were studied before and after losing a mean 3.0%–4.3% of body mass to determine whether muscle performance could be maintained or even enhanced by dietary creatine supplementation. During a 5-day period of loss of mass the subjects were randomly assigned to a creatine or placebo supplemented diet. All the subjects were measured before and after loss of mass on both supplements for isokinetic peak torque (PT) and work at peak torque (W _PT) of knee extensors, also for intermittent high intensity working capacity of the same muscle group. The latter test consisted of submaximal isokinetic knee extensions at an angular velocity of 1.57 rad · s⁻¹ for 45 s at the rate of 30 contractions each min (submaximal work, W _{s max} ) followed by 15-s maximal effort (maximal work, W _max ). Total duration of the test was 3 min. Haematocrit was measured and haemoglobin, ammonia, lactate, glucose and urea concentrations were analysed in blood samples obtained at rest and after cessation of muscle performance tests. The results indicated that creatine supplementation in comparison with placebo treatment during rapid body mass reduction may help to maintain muscle PT and W _PT at high angular velocities, not influencing W _max and the rate of fatigue development during W _max , but affecting adversely W _{s max} . Within the limitations of the present study the reasons for the partially detrimental effect of creatine administration remain obscure, but it is suggested that impaired creatine uptake in muscle during body mass loss as well as creatine induced changes in muscle glucose and glycogen metabolism may be involved. Accepted: 18 December 1997     

Blood lactate accumulation in intermittent supramaximal exercise

Blood lactate accumulation rate and oxygen consumption have been studied in six trained male runners, aged 20 to 30 years. Subjects ran on a treadmill at a rate representing 172 +/- 5% VO2max for four 45 s sessions, separated by 9 min rest periods. Oxygen consumption was measured throughout. Blood lactate was determined in samples taken from the ear and VO2 was measured at the end of each exercise session, and two, five and nine minutes later. After the fourth exercise session, the same measurements were made every five min for 30 min. 4 subjects repeated a single exercise of the same type, duration and intensity and the same measurements were taken. With repetitive intermittent exercise, gradual increases in blood lactate concentration [( LA]b) occurred, whereas its rate of accumulation (delta[LA]b) decreased. The amount of oxygen consumed during each 45 s exercise session remained unchanged for a given subject. After cessation of intermittent exercise, the half-time of blood lactate was 26 min, whereas it was only 15 min after a single exercise session. VO2 values, on the other hand, returned to normal after 15 to 20 min. All other conditions being equal, the gradual decrease in delta[LA]b during intermittent exercise could be explained if the lactate produced during the first exercise session is used during the second period, and/or if the diffusion space of lactate increases. The diffusion space seems to be multi-compartmental on the basis of half-time values noted for [LA]b after intermittent exercise, compared with those noted after a single exercise session.(ABSTRACT TRUNCATED AT 250 WORDS)     

Repeated hyperthermia exposure increases circulating Brain Derived Neurotrophic Factor levels which is associated with improved quality of life,and reduced anxiety: A randomized controlled trial

ContextHyperthermia is known to be beneficial to patients affected by various diseases. Brain Derived Neurotrophic Factor (BDNF) is a marker of neuroplasticity usually increased as response to acute exposure to human body stressors. Little is known about BDNF changes after repeated exposure to hyperthermia.ObjectiveTo investigate the effect of a repeated hyperthermia exposure programme (HTC) on serum BDNF in healthy humans.Design, setting, participantsRandomized, single-blind, controlled trial in healthy humans conducted at Sechenov University Physiology Laboratory between December 2016 and November 2018. The treatment period was 10 weeks. Researchers analysing serum BDNF and questionnaires data were blinded to participants allocation.ParticipantsWere 34 healthy male (age 20.2 ± 1.6 years).InterventionRepeated Hyperthermia exposure programme, HTC, versus Light Intermittent Exercise, LIE, programme as control (10 weeks).Main outcome measureChange in BDNF from baseline to final visit three days after treatment completion.Results25 participants were analyzed. One participant withdrew before signing the informed consent and 8 participants (n = 3 in HTC and n = 5 in LIE) could not undertake the first assessment and were excluded. Mean change in BDNF was higher in HTC group vs LIE after both time points (after 12 and after 24 sessions). After 24 sessions BDNF was 30170 (SD 5268) pg/ml in HTC group a value that was significantly higher than 24104 (SD 2876) pg/ml measured in LIE group. BDNF concentrations were significantly higher than baseline values in HTC group only, 30170 (SD 5268) vs 26710 (SD 5437) pg/ml.ConclusionA 10-week programme consisting of repeated exposure to hyperthermia resulted in a significantly higher increase of circulating BDNF compared to a programme consisting of intermittent light intensity exercise.     

Slight phenotypic variation in predators and prey causes complex predator-prey oscillations

Predator-prey oscillations are expected to show a 1/4-phase lag between predator and prey. However, observed dynamics of natural or experimental predator-prey systems are often more complex. A striking but hardly studied example are sudden interruptions of classic 1/4-lag cycles with periods of antiphase oscillations, or periods without any regular predator-prey oscillations. These interruptions occur for a limited time before the system reverts to regular 1/4-lag oscillations, thus yielding intermittent cycles. Reasons for this behaviour are often difficult to reveal in experimental systems. Here we test the hypothesis that such complex dynamical behaviour may result from minor trait variation and trait adaptation in both the prey and predator, causing recurrent small changes in attack rates that may be hard to capture by empirical measurements. Using a model structure where the degree of trait variation in the predator can be explicitly controlled, we show that a very limited amount of adaptation resulting in 10–15% temporal variation in attack rates is already sufficient to generate these intermittent dynamics. Such minor variation may be present in experimental predator-prey systems, and may explain disruptions in regular 1/4-lag oscillations.     

The Role of Reticulocyte Hemoglobin Content for the Diagnosis of Functional Iron Deficiency in Hemodialyzed patients

The effectiveness of reticulocyte hemoglobin content (CHr) had been reported to detect early functional iron deficiency especially among Chronic kidney disease (CKD) patients. CHr is more superior to classic biochemical indices in reflecting transient iron-deficiency status, therefore improving diagnosis and treatment. This study was conducted to determine the sensitivity of CHr in the diagnosis of functional iron deficiency (FID) in hemodialyzed patients. One hundred hemodialyzed patients along with 60 healthy controls were recruited and blood specimens were collected. Venous blood was used for hematological and biochemical investigations collected via 3 ml lavender-top tubes for hematological tests including CBC, blood film, ESR and CHr, and red-top tube for biochemical tests including TIBC, SF and CRP. A statistically significant decrease was noted in CHr values between hemodialysis patients and the control group (24.8 ± 2.0 pg vs. 30.9 ± 1.3 pg, p<0.001). CHr values showed a significant correlations with RBCs, Hb- hemoglobin, Hct- hematocrit level, MCV- mean corpuscular volume, MCH- mean corpuscular hemoglobin, MCHC, RDW- red cell distribution width , SI-Serum Iron, TIBC- Total iron binding capacity and TSAT- Transferrin saturation. The present study showed that CHr in comparison to the conventional hematological and biochemical markers commonly used to diagnose iron deficiency.