Dialysis unphysiology was first discussed by Carl Kjellstrand in 1975 for the possible negative effects of the unphysiology of intermittent dialysis treatment. Current hemodialysis practices are still unphysiologic because they cannot keep blood chemistries within normal limits, both before and after dialysis. In addition, the discontinuous nature of hemodialysis causes saw-tooth volume fluctuations, and the extracellular fluid volume expansion during the interdialytic period may lead to hypertension and adverse cardiovascular consequences. Sodium, which is accumulated over the interdialytic period, may be divided into two fractions. The one is the fraction of osmotically active sodium which is mainly confined to the extracellular space, and the other is that of water-free (osmotically inactive) sodium which diffuses into the intracellular space. Both contribute to the pathogenesis of hypertension because the former may act to expand extracellular fluid volume and the latter may cause vasoconstriction in the long run by increasing cytosolic concentration of calcium in the vascular smooth muscle cells. Even in intensive hemodialysis, it may take several weeks to months for water-free sodium storage in the vascular smooth muscle cells to be relieved. This may be an explanation for the lag phenomenon, i.e., the delay of blood pressure decrease after normalization of extracellular fluid volume shown in the Tassin experience. Modest restriction of dietary sodium intake, the dialytic session length long enough to maintain a high ultrafiltration volume, and the reasonably low dialysate sodium concentration are required to avoid unphysiology of positive sodium balance in current hemodialysis practice.
Blood Pressure ; Calcium ; Cytosol ; Dialysis ; Extracellular Fluid ; Extracellular Space ; Hypertension ; Intracellular Space ; Muscle, Smooth, Vascular ; Renal Dialysis ; Sodium ; Sodium, Dietary ; Ultrafiltration ; Vasoconstriction

Bioelectrical impedance measurement technology is a non-invasive detection technology for extracting human physiological and pathological information. The analysis method of the relationship between bioimpedance and human physiological parameters is an important part of this technology. In order to calculate the internal and external liquid volume of human cells more accurately, based on the Moissl equation for calculating the internal and external fluid volume of human cells, a segmented human bioimpedance spectrum measurement model and an improved calculation method of intracellular and external fluid capacity were proposed. The measurement and calculation experiments of the intracellular and extracellular fluid volume before and after the human body's water intake were designed and compared with the Moissl calculation method. The results show that the improved calculation method can calculate the intracellular and extracellular fluid volumes more effectively, and the relative error is less than 5%, which may provide new ideas or more accurate methods for the analysis of human body components, facilitating the diagnosis and treatment of diseases.
Body Water ; Electric Impedance ; Extracellular Fluid ; Humans ; Intracellular Fluid

The proper intracellular Ca(2+) signaling is essential for normal cell functions and organ development, and the maintaining Ca(2+) homeostasis in cardiac myocytes is of functional importance for the intact heart. As the first functional organ in the vertebrate embryo, the heart is continuously remodeled and maintains its physiologic pumping function in response to increasing circulatory demands. The expressions of Ca(2+) handing proteins in the embryonic heart, however, are different from those in neonatal and adult hearts, which means that the regulation of Ca(2+) transients in embryonic cardiomyocytes is different from that in adult cardiac myocytes. Recent advances in molecular and cellular biology, as well as the application of embryonic stem cell differentiation system, have made progress in uncovering the regulation of Ca(2+) homeostasis during cardiomyogenesis. This paper briefly summarizes the Ca(2+) homeostasis during early development of cardiomyocytes and reviews current knowledge of the regulatory mechanisms controlling Ca(2+) homeostasis during cardiomyocyte development.
Calcium ; physiology ; Calcium Channels ; metabolism ; physiology ; Calcium Signaling ; Heart ; embryology ; Homeostasis ; physiology ; Humans ; Intracellular Fluid ; physiology ; Myocytes, Cardiac ; metabolism ; physiology

Background: Insulin is known to act as second effector that provides potassium transfer from extracellular fluid to intracellular fluid, thus causing hypokalemia and arrythmia. We evaluated the effect of magnesium sulfate treatment on hemodynamics and serum potassium concentration, induced by continuous infusion of regular insulin solution in rabbits. Method: Twenty-four rabbits were divided into four groups for the experiment. Group I was given intravenouse injection of 5 ml of normal saline and continuous dripping of 7.5 U of RI. Group II was pretreated with 30 mg/kg of magnesium sulfate, followed by continuous dripping of 7.5 U of RI. Group III was given 5 ml of normal saline and 15 U of RI. And Group IV was administered 15 U of RI after 30 mg/kg of magnesium sulfate pretreatment. Venouse blood sampling was done before pretreatment, and after 5, 30, 60 and 120 minutes respectively. Heart rate and arterial blood pressure were taken at the same intervals. Result: 1) There was no significant change in serum potassium concentration in groups injected with 7.5 units of RI respectively (groups I and II), regardless of magnesium pretreatment. But in groups injected with 15 units of RI, the group that was not pretreated with magnesium (Groups III) showed a decrease in serum potassium concentration from 3.39+/-0.57 Eq/L to 2.29+/-0.71 mEq/L, while the concentration in the pretreated group (Group IV) decreased more significantly from 3.35+/-0.50 mEq/L to 1.81+/-0.41 mEq/L. 2) Pulse rate did not change significantly in groups that received continuous infusion of 7.5 units of RI (groups I and II) regardless of magnesium pretreatment, but increased significantly in groups injected with 15 units of RI (groups III and IV), pretreated or not. The pretreated group (group IV) had a more significant rise in pulse rate compared with the group that was not pretreated (group III). 3) In all of the groups, those pretreated with magnesium (groups II and IV) and those not pretreated (groups I and III), there was no significant change in systolic and diastolic blood pressures. Nor was arrhythmia detected. Conclusion: The above results indicate that while magnesium sulfate pretreatment at 30 mg/kg with insulin infusion affects serum potassium concentration, has an antiarrhythmic effect, and may induce tachycardia, it does not have any significant effect on blood pressure.
Arrhythmias, Cardiac ; Arterial Pressure ; Blood Pressure ; Extracellular Fluid ; Heart Rate ; Hemodynamics* ; Hypokalemia ; Insulin ; Intracellular Fluid ; Magnesium Sulfate ; Magnesium* ; Potassium* ; Rabbits* ; Tachycardia

PURPOSE: Body composition is important to define and manage obesity and undernutrition. Obesity is a significant health problem with medical and psychological consequences for children and adolescents. Body composition analysis (BIA) is a simple, rapid, noninvasive, and reproducible technique. However, comparative analysis of body composition has not been done in young children below 7 years old. The aim of this study is to estimate antropometric data and body composition by BIA, and to investigate the correlation between anthropometric data and fat mass or fat percent in young children. METHODS: We measured height, weight, body mass index (BMI), fat mass, and fat percent by BIA in 1,376 children aged 3-6 years of whom 688 were males and 688 were females. RESULTS: Fat mass, fat percent, intracellular fluid, extracellular fluid, protein, and minerals were significantly higher in the obese group. A significant positive correlation exists between fat mass and BMI or weight. A significant positive linear correlation was also noted between fat percent and BMI. Protein, weight, fat mass, and fat percent were significantly different among groups. CONCLUSION: BIA is an objective, accurate method to estimate body fat in childhood obesity cases. Fat mass and fat percent data acquired by using BIA highly correlated with BMI. However, a large-scale study is needed to diagnose obesity in young children.
Adipose Tissue ; Adolescent ; Aged ; Body Composition ; Body Weight ; Child ; Electric Impedance ; Extracellular Fluid ; Female ; Humans ; Intracellular Fluid ; Male ; Malnutrition ; Minerals ; Obesity

Cataplexy is one of the most pathognomonic symptoms in narcolepsy. This study was designed to investigate the frequency of the HLA-DQB1 allele and cerebrospinal fluid (CSF) hypocretin levels in Korean narcoleptics with cataplexy as compared with those who do not have cataplexy. Seventy-two narcoleptics were selected based on polysomnography and multiple sleep latency test as well as their history and clinical symptoms at Sleep Disorders Clinic. The patients were divided into a narcolepsy with cataplexy group (n=56) and a narcolepsy without cataplexy group (n=16). All patients were subjected to HLA typing to determine the frequency of DQB1 allele and to spinal tapping to measure the level of CSF hypocretin. In cataplexy-positive patients, as compared with cataplexy-negative patients, the frequency of HLA-DQB1*0602 was found to be significantly high (89.3% vs. 50.0%) (p=0.003). On the other hand, the frequency of HLA-DQB1*0601 was found to be significantly low (0% vs. 43.8%) (p<0.001). In 48 of 56 cataplexy-positive patients (85.7 %), hypocretin levels were decreased (< or =110 pg/mL). However, only 6 of 16 cataplexy-negative patients (37.5%) exhibited a decreased hyopcretin level (p<0.001). The high frequency of HLA-DQB1*0602, low frequency of HLA-DQB1*0601 and low hypocretin levels in cataplexy-positive groups suggest that cataplexy-positive narcolepsy might be an etiologically different disease entity from the cataplexy-negative.
Sleep, REM ; Neuropeptides/*cerebrospinal fluid ; Narcolepsy/cerebrospinal fluid/*genetics ; Middle Aged ; Male ; Intracellular Signaling Peptides and Proteins/*cerebrospinal fluid ; Humans ; HLA-DQ Antigens/*genetics ; Female ; Child ; Cataplexy/cerebrospinal fluid/*genetics ; *Alleles ; Aged ; Adult ; Adolescent

PURPOSE: The product of the ob gene, leptin is an adipocyte specific hormone that might be involved in the regulation of food intake by the central neuroendocrine system. Recent studies reported that serum leptin concentrations were correlated with Body mass index(BMI) and other obesity measurements. The aims of this study were to evaluate leptin concentrations according to degree of obesity and to assess the relationship between serum leptin concentrations and other obesity parameters. METHODS: 84 children were included in this study. BMI was calculated and body compositions such as fat mass, protein, minerals, intracellular fluid and extacellular fluid were measured by bioelectrical impedance analysis. Serum lipid and insulin were measured after 12 hours overnight fasting. Serum leptin levels were estimated using DSL-23100 leptin coated tube Immunoradiometric assay kit. RESULTS: Serum leptin concentrations were 22.7 +/- 8.2 ng/mL in obese group, 16.7 +/- 8.4 ng/mL in high risk group. In control group, serum leptin concentrations were 3.8 +/- 2.9 ng/mL. Serum leptin concentrations were significantly increased in obese group and positively correlated with degree of obesity. Serum insulin levels were significantly increased in obesity group. Serum leptin concentrations were significantly correlated with body fat percent, fat mass, BMI, subscapular skinfold thickness, triceps skinfold thickness. CONCLUSIONS: Serum leptin and insulin levels were significantly increased in obese group and highly correlated with fat percent, fat mass, BMI, subscapular skinfold thickness and triceps skinfold thickness. Serum leptin levels will be importent predictor in obesity.
Adipocytes ; Adipose Tissue ; Body Composition ; Child* ; Eating ; Electric Impedance ; Fasting ; Humans ; Hyperinsulinism ; Immunoradiometric Assay ; Insulin ; Intracellular Fluid ; Leptin* ; Minerals ; Neurosecretory Systems ; Obesity ; Skinfold Thickness

OBJECTIVETo investigate the underlying mechanism for the selective modulation of the permeability of blood-tumor barrier (BTB) by small dose of bradykinin (BK).

METHODSC6 glioma cells were treated with BK, and changes of intracellular nitric oxide (NO) and intracellular calcium level were measured with fluorescent spectrophotometer.

RESULTSThe initial application of BK easily triggered extracellular calcium influx, which resulted in intracellular calcium store release in C6 glioma cells. The above mechanism was also named ryanodine mediated calcium induced calcium release (CICR). We also detected a long-lasting intracellular NO elevation in C6 glioma cells upon BK treatment. Further study showed that ryanodine mediated CICR contributed greatly to the secondary NO elevation induced by BK treatment.

CONCLUSIONThese results suggested that BK triggered CICR in C6 glioma cells and the associated NO generation might be the underlying mechanism for the selective modulation of BTB permeability by BK.

Animals ; Bradykinin ; pharmacology ; Calcium ; metabolism ; Cell Line, Tumor ; Glioma ; pathology ; Intracellular Fluid ; drug effects ; Nitric Oxide ; metabolism ; Rats ; Ryanodine ; pharmacology ; Spectrometry, Fluorescence ; methods ; Time Factors

BACKGROUND: In ESRD patients, malnutrition and atherosclerosis are strongly associated with inflammation resulting in MIA (Malnutrition-Inflammation-Atherosclerosis) syndrome. As compared with atherosclerosis, arteriosclerosis or arterial stiffening is another important cardiovascular risk factor. Therefore, we speculated on the presence of new MIA syndrome, which is composed of malnutrition, inflammation and arteriosclerosis, and evaluated causal relations among them in 70 chronic hemodialysis patients (age 53+/-13 years, male 53%, diabetes 40%). METHODS: As an indicator of arterial stiffness, brachial-ankle pulse wave velocity (PWV) was measured using a plethysmography. PWV index (measured PWV/nomogram based theoretical PWV) was then calculated to adjust confounding effects of age, blood pressure, and gender by using the PWV nomogram obtained in nonuremic population with same age, blood pressure, and gender. Nutritional status was assessed by serum albumin level, subjective global assessment (SGA) and normalized protein catabolic rate (nPCR). Extracellular fluid and intracellular fluid volume ratio (ECF/ICF) were determined using bioimpedance analysis. The presence of an inflammation was assessed by serum high sensitivity C-reactive protein (CRP) level. RESULTS: PWV index correlated positively with log transformed CRP (LnCRP) level, ECF/ICF and negatively with SGA, nPCR and serum albumin level. Serum albumin level correlated positively with nPCR, BUN, hemoglobin level and negatively with LnCRP level, age and ECF/ICF. Diabetic patients had higher PWV index and lower albumin level than non-diabetic patients. In multiple regression analysis, only LnCRP level was a significant common determinant of the both PWV index (R2=0.419; p >0.001) and serum albumin level (R2=0.543; p<0.001). CONCLUSION: Increased CRP levels are independently associated with arterial stiffening and hypoalbuminemia. Inflammation might be a linking mechanism of arterial stiffening and malnutrition in chronic hemodialysis patients.
Arteriosclerosis ; Atherosclerosis ; Blood Pressure ; C-Reactive Protein ; Extracellular Fluid ; Humans ; Hypoalbuminemia ; Inflammation* ; Intracellular Fluid ; Kidney Failure, Chronic ; Male ; Malnutrition* ; Nomograms ; Nutritional Status ; Plethysmography ; Pulse Wave Analysis ; Renal Dialysis* ; Risk Factors ; Serum Albumin ; Vascular Stiffness*

PURPOSE: Obesity is associated with disturbances of ventilatory functions in adults. But few studies have evaluated the pulmonary complications of obesity in the pediatric population. The purpose of this study is to clarify the effects of obesity on pulmonary function and body composition in obese children. METHODS: Forty seven obese children whose ages ranged from nine to twelve years were evaluated for their body composition (intracellular fluid, extracellular fluid, protein mass, mineral mass, soft lean mass, fat mass, percent body fat, fat distribution) by bioelectrical impedance analysis. Hemoglobin, serum glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol and triglycerides were measured. Pulmonary function test was performed by spirometer. RESULTS: Intracellular fluid, protein mass, fat mass, percent body fat and fat distribution were significantly higher in severely obese children with an obesity index of more than 150 percent compared with those with an index of less than 150 percent. Peak expiratory flow rate (PEFR) was significantly lower in severely obese children with obesity index of more than 150 percent compared with those with less than 150 percent (241.7+/-14.6 L/sec vs 276.8+/-64.3 L/sec). PEFR, forced expiratory flow 25 percent (FEF25), mid expiratory flow rate (MEFR), forced expiratory flow 50 percent (FEF50), forced expiratory volume in 1st second (FEV1) and forced vital capacity (FVC) were decreased in 37.0 percent, 14.8 percent, 14.8 percent, 11.1 percent, 3.7 percent and 3.7 percent of obese children, respectively. CONCLUSION: PEFR was significantly decreased in obese children. Pulmonary function test must be performed in severely obese children and more extended study is needed in other age groups.
Adipose Tissue ; Adult ; Alanine Transaminase ; Aspartate Aminotransferases ; Blood Glucose ; Body Composition* ; Child* ; Cholesterol ; Electric Impedance ; Extracellular Fluid ; Forced Expiratory Volume ; Humans ; Intracellular Fluid ; Obesity ; Peak Expiratory Flow Rate ; Respiratory Function Tests* ; Triglycerides ; Vital Capacity