Relación del volumen de agua corporal total, el extracelular, y preeclampsia. Revisión narrativa de la literatura / Relation of total and extracellular body water and preeclampsia. Literature review

RESUMEN La preeclampsia es una importante causa de mortalidad materna mundial, identificar de manera temprana las gestantes con riesgo de desarrollarla, es una medida preventiva de gran impacto. La medición del agua corporal se ha documentado desde 1994, y desde 2015 se demostró su relación con el riesgo de desarrollar preeclampsia. Por lo anterior se realizó una revisión de la relación del agua corporal y la preeclampsia hasta junio de 2019, con 17 artículos seleccionados. Producto de la revisión se concluyó que la medición del agua corporal en gestantes podría detectar la aparición de preeclampsia para establecer un seguimiento estricto temprano a las mujeres con mayor riesgo de presentarla. Estas mediciones se realizan con métodos sencillos, no invasivos y de bajo costo, como la impedancia eléctrica por análisis espectral. Sin embargo, se requieren estudios con mayor rigor metodológico para el estudio de una prueba diagnóstica como la que se propone. MÉD.UIS.2021;34(2): 49-60.

ABSTRACT Preeclampsia is an important cause of maternal mortality worldwide. Early identification of pregnant women at risk of developing it is a preventive measure of great impact. Body water measurement has been documented since 1994, and since 2015 it was stablished its relationship with risk of developing preeclampsia. Therefore, a review of the relationship between body water and preeclampsia was carried out until June 2019, with 17 papers selected. As a result of the review, it was concluded that the measurement of body water in pregnant women could detect the appearance of preeclampsia to establish a strict early follow-up of women with a higher risk of presenting it. These measurements are made with simple, non-invasive and low-cost procedure, such as electrical impedance by spectral analysis. However, studies with greater methodological rigor are required for the study of a diagnostic test such as the one proposed. MÉD.UIS.2021;34(2): 49-60.

Agua corporal total y composición corporal: efecto del ejercicio de 30 minutos y rehidratación con agua en adultos residentes permanentes de gran altitud, La Paz Bolivia / Total body water and body composition: effect of the 30 minute exercise and water rehydration in high altitude permanent resident adults, La Paz-Bolivia

PREGUNTA DE INVESTIGACIÓN: ¿Cuál será la composición corporal, el agua corporal total, y el agua extra e intracelular relacionados a los cambios después del ejercicio submáximo de 30 minutos y post rehidratación con agua pura en adultos residentes permanentes de gran altitud, La Paz, Bolivia, gestión 2019? OBJETIVO: Determinar la composición corporal, el agua corporal total, y el agua extra e intracelular relacionados a los cambios después del ejercicio submáximo de 30 minutos y post rehidratación con agua pura en adultos residentes permanentes de gran altitud, La Paz, Bolivia, gestión 2019. MATERIAL Y MÉTODOS: el trabajo de investigación fue tipo experimental, antes y después, sobre Fisiología de Altitud, en 29 jóvenes residentes de gran altitud (3600 m.s.n.m.). Se evaluó variables antes y después de realizar una prueba de ejercicio submáxima, de 30 minutos, y la rehidratación post ejercicio, tras el consumo de agua pura. Variables dependientes fueron: 1. Composición corporal, medida a través del análisis de impedancia bioeléctrica (AIB), 2. Volumen de agua corporal total, determinado por AIB. 3. Agua extra e intracelular evaluada por AIB y 4. Estado de rehidratación, evaluado por el cambio de peso post ejercicio, y mediante el AIB. Las variables independientes fueron el ejercicio a través de la prueba submáxima de 30 minutos y la rehidratación con agua pura. RESULTADOS: en jóvenes residentes de gran altitud, se estima que el porcentaje de agua corporal total en las mujeres está disminuida en relación a la referencia de poblaciones del nivel del mar. La masa grasa corporal está muy incrementada en las mujeres. La diferencia de agua basal versus el agua post ejercicio entre varones y mujeres no es significativa. La diferencia de agua del líquido extra e intracelular basal versus el agua post ejercicio entre varones y mujeres no es significativa. La diferencia en la distancia recorrida en 30 minutos de ejercicio de trote submáximo es estadísticamente significativa a favor de los varones (4424 vs. 3619 metros). La correlación del IMC y el porcentaje de masa grasa es muy baja (r=0.109). El IMC entre varones y mujeres no presenta diferencia estadísticamente significativa (26±3 vs 24±3 respectivamente). La frecuencia de exceso de grasa corporal evaluada por AIB, es del 55% en las mujeres y de 0% en varones. La presión arterial sistémica en varones (PS: 107±6 y PD:73± 4mmHg) y en mujeres (PS:104±8 y PD:70± 7mmHg), está disminuida en relación a referencia del nivel del mar. La frecuencia respiratoria esta incrementada tanto en varones (21±2) y mujeres (23±3). CONCLUSIONES: el método de AIB permite evaluar la composición corporal y el agua corporal total y por tanto la masa grasa, mismo que fue validado en altitud por el método estándar de referencia de dilución isotópica en estudios previos en altitud. El ejercicio de trote submáximo ejecutado, ha exigido más a los universitarios estudiados. Se verifica que en el mismo tiempo los varones han recorrido una mayor distancia que las mujeres. Se estima que en mujeres la masa grasa corporal (MGC) esta incrementada y que el exceso de grasa (obesidad) es del 55%. La diferencia del agua al momento basal y post ejercicio y el LEC y LIC entre varones y mujeres no es significativa. El IMC subestima en este grupo la frecuencia de obesidad, principalmente en mujeres. El uso de técnicas nucleares, ha permitido a través del análisis del deuterio estudiar el agua, la composición corporal, y se asocia fuertemente con determinaciones similares mediante el uso de la bioimpedancia eléctrica.

RESEARCH QUESTION: what will be the body composition, the total body water, and the extra and intracellular water related to the changes after submaximal exercise of 30 minutes and post rehydration with pure water in permanent resident adults of high altitude, La Paz, Bolivia, management 2019? OBJECTIVE: to determine the body composition, the total body water, and the extra and intracellular water related to the changes after submaximal exercise of 30 minutes and post rehydration with pure water in permanent residents of high altitude adults, La Paz, Bolivia, management 2019. MATERIAL AND METHODS: the research work was experimental, before and after, on Altitude Physiology, in 29 young residents of high altitude (3600 m.a.s.l.). Variables were evaluated before and after performing a 30-minute submaximal exercise test and post-exercise rehydration after consuming pure water. Dependent variables were: 1. Body composition, measured through bioelectrical impedance analysis (AIB), 2. Total body water volume, determined by AIB. 3. Extra and intracellular water evaluated by AIB and 4. Rehydration status, evaluated by post-exercise weight change, and by AIB. The independent variables were exercise through the 30-minute submaximal test and rehydration with pure water. RESULTS: in young residents of high altitude, it is estimated that the percentage of total body water in women is decreased in relation to the reference of sea level populations. Body fat mass is greatly increased in women. The difference in basal water versus post-exercise water between men and women is not significant. The difference in water from basal extra and intracellular fluid versus post-exercise water between men and women is not significant. The difference in distance covered in 30 minutes of submaximal jogging exercise is statistically significant in favor of men (4424 vs. 3619 meters). The correlation of BMI and the percentage of fat mass is very low (r = 0.109). The BMI between men and women did not present a statistically significant difference (26 ± 3 vs 24 ± 3 respectively). The frequency of excess body fat evaluated by AIB is 55% in women and 0% in men. The systemic blood pressure in men (PS: 107 ± 6 and PD: 73 ± 4mmHg) and in women (PS: 104 ± 8 and PD: 70 ± 7mmHg), is decreased in relation to the sea level reference. Respiratory rate is increased in both men (21 ± 2) and women (23 ± 3). CONCLUSIONS: the AIB method allows evaluating body composition and total body water and therefore fat mass, which was validated at altitude by the isotopic dilution reference standard method in previous studies at altitude. The submaximal trot exercise performed has demanded more from the university students studied. It is verified that in the same time the men have traveled a greater distance than the women. It is estimated that in women the body fat mass (FGM) is increased and that the excess fat (obesity) is 55%. The difference in water at baseline and post-exercise and the LEC and LIC between men and women is not significant. The BMI underestimates the frequency of obesity in this group, mainly in women. The use of nuclear techniques has allowed the analysis of deuterium to study water, body composition, and is strongly associated with similar determinations through the use of electrical bioimpedance.

Study on calculation method of internal and external fluid capacity of human cells based on bioimpedance spectroscopy / 生物医学工程学杂志

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.

Comparison of Extracellular and Intracellular Fluid Distribution Between Stomach Meridian or Gallbladder Meridian and Their Neighboring Tissues of Lower Leg in Healthy Volunteers / 针刺研究

OBJECTIVE: To compare differences of extracellular fluid impedance (Re) and intracellular fluid impedance (Ri) between the Stomach(ST) Meridian or Gallbladder(GB) Meridian and their neighboring non-meridian sites of the left lower leg at the same level, so as to explore the distribution characteristics of body fluid in the meridian. METHODS: Sixteen healthy volunteers were enrolled in the present study. The Re and Ri were detected by using Ag/AgCl electrodes and a digital lock-in amplifier. The measuring electrodes (at an interval of about 3 cm) were separately fixed to the skin sites covering the running courses of the ST Meridian (in the lateral interspace of the anterior tibial muscle)and the GB Meridian (in the interspace of the anterior edge of the fibula), and the excitation electrodes (at an interval of about 9 cm) respectively fixed to the skin sites covering the anterior tibial muscle and the interspace between the anterior tibial muscle and the tibia (about 2 cm and 5 cm lateral to the ST and GB meridians, and about 3－4 cm and 6－8 cm lateral to the ST and GB meridians, respectively). A 100 µA constant current with frequencies from 1 kHz to 100 kHz delivered via an excitation electrode was applied to the site (control spots of the ST Meridian), and signals of the voltage amplitude and phase difference of the tissues fed to the lock-in amplifier via the measuring electrode were collected, followed by measuring those of the GB Meridian and control sites. The circumference of the lower leg around the two excitation and measuring electrodes was measured. Then the cole-cole curve fitting was performed to calculate the Ri and Re, as well as the intracellular fluid resistivity (ρi) and extracellular fluid resistivity (ρe) of the ST and GB meridians, the related muscles and interspace lateral to ST or GB (ST/GB) meridians at the same level. RESULTS: The Ri and Re (Ω) values of the ST, GB, the muscle lateral to ST/GB and the interspace lateral to ST/GB were 19.1±1.3 and 28.3±1.4, 15.8±1.9 and 25.7±2.0, 19.6±1.3 and 31.3±1.6, and 19.4±1.2 and 32.4±1.6, respectively. The Re values were significantly lower at the ST and GB meridians than at the muscle lateral to and the interspace lateral to both meridians (P<0.05). The ρi and ρe values (Ω•cm) of the ST, GB, the muscle lateral to and the interspace lateral to ST/GB were 658.9±78.5 and 953.8±75.3, 528.0±90.1 and 833.9±101.7, 669.9±71.8 and 1 059.8±86.0, 655.9±64.8 and 1 099.3±93.3, respectively. The ρi and ρe values were significantly lower at the GB Meridian Than at the other three locntions, and the ρe value of ST Meridian was significantly lower than those of the muscle lateral to and the interspace lateral to ST/GB meridians (P<0.01)．. CONCLUSION: The Ri, Re, ρi and ρe values of the ST and GB meridians are significantly lower than those of their neighboring tissues at the same levels of the lower leg, suggesting a more extracellular fluid in the meridian running course and providing evidence for our speculation that the meridian is a hydraulic resistance channel.

Variables associated with lung congestion as assessed by chest ultrasound in diabetics undergoing hemodialysis / Variáveis associadas a congestão pulmonar avaliada por ultrassonografia em diabéticos submetidos a hemodiálise

Abstract Introduction: Ultrasound is an emerging method for assessing lung congestion but is still seldom used. Lung congestion is an important risk of cardiac events and death in end-stage renal disease (ESRD) patients on hemodialysis (HD). Objective: We investigated possible variables associated with lung congestion among diabetics with ESRD on HD, using chest ultrasound to detect extracellular lung water. Methods: We studied 73 patients with diabetes as the primary cause of ESRD, undergoing regular HD. Lung congestion was assessed by counting the number of B lines detected by chest ultrasound. Hydration status was assessed by bioimpedance analysis and cardiac function by echocardiography. The collapse index of the inferior vena cava (IVC) was measured by ultrasonography. All patients were classified according to NYHA score. Correlations of the number of B lines with continuous variables and comparisons regarding the number of B lines according to categorical variables were performed. Multivariate linear regression was used to test the variables as independent predictors of the number of B lines. Results: None of the variables related to hydration status and cardiac function were associated with the number of B lines. In the multivariate analysis, only the IVC collapse index (b = 45.038; p < 0.001) and NYHA classes (b = 13.995; p = 0.006) were independent predictors of the number of B lines. Conclusion: Clinical evaluation based on NYHA score and measurement of the collapsed IVC index were found to be more reliable than bioimpedance analysis to predict lung congestion.

Resumo Introdução: A ultrassonografia é um método emergente e ainda raramente utilizado na avaliação da congestão pulmonar. A congestão pulmonar é um importante fator de risco para eventos cardíacos e óbito entre pacientes com doença renal terminal (DRT) em hemodiálise (HD). Objetivo: Foram investigadas as possíveis variáveis associadas a congestão pulmonar em indivíduos diabéticos com DRT em HD, utilizando a ultrassonografia torácica para detectar água extracelular nos pulmões. Métodos: Foram estudados 73 pacientes com diabetes como causa primária de DRT submetidos a HD regular. A congestão pulmonar foi avaliada pela contagem do número de linhas B detectadas por ultrassonografia torácica. O estado de hidratação foi avaliado por análise de bioimpedância e a função cardíaca por ecocardiografia. O índice de colabamento da veia cava inferior (VCI) foi medido por ultrassonografia. Todos os pacientes foram classificados segundo a escore da NYHA. Foram analisadas as correlações entre o número de linhas B e variáveis contínuas e as comparações entre o número de linhas B em relação às variáveis categóricas. Regressão linear multivariada foi utilizada para testar as variáveis enquanto preditores independentes do número de linhas B. Resultados: Nenhuma das variáveis relacionadas a estado de hidratação e função cardíaca apresentou associação com o número de linhas B. Na análise multivariada, apenas o índice de colabamento da VCI (b = 45,038; p < 0,001) e as classes da NYHA (b = 13,995; p = 0,006) foram preditores independentes do número de linhas B. Conclusão: A avaliação clínica baseada na classificação da NYHA e na medição do índice de colabamento da VCI foram mais confiáveis do que a análise de bioimpedância para predizer congestão pulmonar.

Serotoninergic Modulation of Basal Cardiovascular Responses and Responses Induced by Isotonic Extracellular Volume Expansion in Rats / Modulação Serotoninérgica de Respostas Cardiovasculares Basais e Induzidas pela Expansão Isotônica do Volume Extracelular em Ratos

Abstract Background: Isotonic blood volume expansion (BVE) induced alterations of sympathetic and parasympathetic activity in the heart and blood vessels, which can be modulated by serotonergic pathways. Objective: To evaluate the effect of saline or serotonergic agonist (DOI) administration in the hypothalamic paraventricular nucleus (PVN) on cardiovascular responses after BVE. Methods: We recorded pulsatile blood pressure through the femoral artery to obtain the mean arterial pressure (MAP), systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR) and the sympathetic-vagal ratio (LF/HF) of Wistar rats before and after they received bilateral microinjections of saline or DOI into the PVN, followed by BVE. Results: No significant differences were observed in the values of the studied variables in the different treatments from the control group. However, when animals are treated with DOI followed by BVE there is a significant increase in relation to the BE control group in all the studied variables: MBP (114.42±7.85 vs 101.34±9.17); SBP (147.23±14.31 vs 129.39±10.70); DBP (98.01 ±4.91 vs 87.31±8.61); HR (421.02±43.32 vs 356.35±41.99); and LF/HF ratio (2.32±0.80 vs 0.27±0.32). Discussion: The present study showed that the induction of isotonic BVE did not promote alterations in MAP, HR and LF/HF ratio. On the other hand, the injection of DOI into PVN of the hypothalamus followed by isotonic BVE resulted in a significant increase of all variables. Conclusion: These results suggest that serotonin induced a neuromodulation in the PVN level, which promotes an inhibition of the baroreflex response to BVE. Therefore, the present study suggests the involvement of the serotonergic system in the modulation of vagal reflex response at PVN in the normotensive rats.

Resumo Fundamento: Expansão de volume extracelular (EVEC) promove alterações da atividade simpática e parassimpática no coração e vasos sanguíneos, os quais podem ser moduladas por vias serotoninérgicas. Objetivo: Avaliar o efeito da administração de salina ou agonista serotoninérgico (DOI) nos núcleos paraventriculares hipotalâmico (NPV) sobre respostas cardiovasculares após EVEC. Métodos: Foram obtidos registros da pressão arterial pulsátil, por meio da artéria femoral, para obtenção dos valores da pressão arterial média (PAM), sistólica (PAS), diastólica (PAD), frequência cardíaca (FC) e razão simpático-vagal (LF/HF) de ratos Wistar antes e após receberem microinjeções bilaterais no NPV de salina ou DOI seguida de EVEC. Resultados: Não foram observadas diferenças significativas dos valores das variáveis estudadas nos diferentes tratamentos do grupo controle. Entretanto, quando os animais são tratados com DOI seguida de EVEC ocorre aumento significativo em relação ao grupo controle com EVEC em todas as variáveis estudadas: PAM (114,42±7,85 vs 101,34±9,17), PAS (147,23±14,31 vs 129,39±10,70), PAD (98,01 ±4,91 vs 87,31±8,61), FC (421,02±43,32 vs 356,35±41,99) e LF/HF (2,32±0,80 vs 0,27±0,32). Discussão: O presente estudo mostrou que a indução de EVEC isotônica não promoveu alterações na PAM, PAD, PAS, FC e LF/HF. Por outro lado, os animais que receberam microinjeção de DOI no NPV seguida de EVEC apresentaram aumento significativo de todas as variáveis. Conclusão: Esses resultados sugerem que a serotonina exerce uma neuromodulação em nivel do NPV, e essa promove uma inibição da resposta barorreflexa frente à EVEC. Assim, o presente trabalho sugere o envolvimento serotoninérgico na neuromodulação no nivel do NPV na resposta reflexa vagal em ratos normotensos.

Artificial Pancreas: A Concise Review / 임상당뇨병

Artificial pancreas is a technique developed to automatically control blood glucose in people with diabetes by providing an endocrine function instead of a healthy pancreas. The technique was developed for the replacement of insulin secretion deficiencies among various exocrine and endocrine functions of the pancreas and is mainly used for people with type 1 diabetes or those who need intensive insulin treatment. This review briefly summarizes the working principles, components, recent clinical research, and future perspectives of artificial pancreas.

Evaluation of a Novel Glucose Area Under the Curve (AUC) Monitoring System: Comparison with the AUC by Continuous Glucose Monitoring

BACKGROUND: Management of postprandial hyperglycemia is a key aspect in diabetes treatment. We developed a novel system to measure glucose area under the curve (AUC) using minimally invasive interstitial fluid extraction technology (MIET) for simple monitoring of postprandial glucose excursions. In this study, we evaluated the relationship between our system and continuous glucose monitoring (CGM) by comparing glucose AUC obtained using MIET with that obtained using CGM for a long duration. METHODS: Twenty diabetic inpatients wearing a CGM system were enrolled. For MIET measurement, a plastic microneedle array was applied to the skin as pretreatment, and hydrogels were placed on the pretreated area to collect interstitial fluid. Hydrogels were replaced every 2 or 4 hours and AUC was predicted on the basis of glucose and sodium ion levels. RESULTS: AUC predicted by MIET correlated well with that measured by CGM (r=0.93). Good performances of both consecutive 2- and 4-hour measurements were observed (measurement error: 11.7%±10.2% for 2 hours and 11.1%±7.9% for 4 hours), indicating the possibility of repetitive measurements up to 8 hours. The influence of neither glucose fluctuation nor average glucose level over the measurement accuracy was observed through 8 hours. CONCLUSION: Our system showed good relationship with AUC values from CGM up to 8 hours, indicating that single pretreatment can cover a large portion of glucose excursion in a day. These results indicated possibility of our system to contribute to convenient monitoring of glucose excursions for a long duration.

Low-frequency hippocampal stimulation increases the extracellular γ-aminobutyrate level in the brain, inhibits the epileptic seizures and after discharges of the amygdala in pharmacoresistant temporal lobe epileptic rats / 中华神经科杂志

Objective To establish a multi-drug resistant model of temporal lobe epilepsy and observe the effect of hippocampal stimulation on pharmacoresistant epileptic rats and its possible mechanism with the use of indexes including after discharges (AD) of the amygdalae,the stimulus-induced seizures and the extracellular levels of γ-aminobutyrate (GABA).Methods Totally,120 Wistar rats were used for the amygdaloid kindled model of epilepsy by chronic stimulation of amygaloid basal lateral nucleus.Based on the successful kindled model of epilepsy,we selected the pharmacoresistant and pharmacosensitive epileptic rats according to their response to phenobabital and phenytoin.We then divided the pharmacoresistant epileptic rats into the hippocampal stimulation group and control group,with 8 rats in each group.Low-frequency stimulus was conducted for two weeks in the hippocampal stimulation group.The hippocampus extracellular fluid collected by microdialysis was then used to determine the levels of GABA by a high performance liquid chromatography method after hippocampal stimulation.Results The stimulus-induced seizures were inhibited significantly,and the frequency of the AD was decreased,as well as the amplitude,compared with the control group.The extracellular level of GABA in the 8:00-9:00 am and the 8:00-9:00 pm was (32.69 ± 7.80) and (35.76 ± 6.27) μg/ml,respectively,both significantly increased as compared with the control ((26.58 ± 6.87) μg/ml,t =-21.45,P =0.000 ; (31.50 ± 4.87) μg/ml,t =-15.74,P =0.000).Conclusions The low-frequency hippocampal stimulation inhibits the seizures of the kindled model of epilepsy and decreases the frequency,the amplitude,as well as the duration of the amygdale AD in the pharmacoresistant epileptic rats,which may be contributed to the increased GABA content in extracellular fluid of the brain after stimulation.

Establishment of a rat model of trigeminal neuralgia induced by photochemical nerve injury / 中国药理学通报

Aim To investigate the behavioral changes of the pain related neuromodulation and neurotransmission in peripheral and central nervous systems in rats with trigeminal neuralgia (TN)and provide a disease relevant animal model for mecha-nism study of TN.Methods The male SD rats were randomly divided into sham operation group and TN surgical group.The latter group was further divided into model group and gabapentin group (100 mg · kg-1 ). TN was induced by intravenous erythrosine B injection and laser irradiation.The pain behavior of rats was evaluated using mechanical pain threshold measured with Von Frey hairs.Fluorescence quantitative PCR technique was deployed to study the change of Tac1 mRNA expressions in trigeminal ganglia.Utilizing microdialysis technique followed by high performance liquid chromatography fluorescence detection (HPLC-FLD),the extracellular striatum fluid was collected and glutamate(Glu)concentration was determined.Results In the model group,the average mechanical pain threshold in facial ar-ea innervated by the trigeminal nerve remained below 4g after 7 days post surgery.The mechanical threshold of the model group (1.63 ±1.27)g was significantly lower (P<0.01)than the control group (24.17 ±4.49)g on day10 post surgery.In gen-eral,the mechanical withdraw threshold was decreased from the preoperative value of 26g to the postoperative value of (1.60 ± 1.74)g (P<0.01),and maintained stable at (0.71 ±1.24) g during the whole dynamic monitoring period from day7 to day60.The successful rate of this model was 63%.After sur-gery,Tac1 mRNA expression in trigeminal ganglia and extracel-lular Glu levels in striatum were significantly up-regulated (P<0.05 ) in the model group. Animals receiving Gabapentin showed significant improvement in pain symptoms,as well as re-ductions of Tac1 mRNA expression in trigeminal ganglia and ex-tracellular Glu concentration in striatum (P<0.05 ).Conclu-sions The above described photochemically induced TN rat model can partially mimic the clinical TN symptoms and its pathophysiology.Considering its overall high stability,it is very likely that this model could be used in preclinical mechanism study or drug screening of TN.

The Influence of Exogenous Fat and Water on Lumbar Spine Bone Mineral Density in Healthy Volunteers

PURPOSE: Changes in human body composition can affect the accuracy of spine bone mineral density (BMD) measurements. The purpose of this study was to evaluate whether fat and water in the soft tissue of the abdomen influence lumbar spine BMD measurements obtained using dual energy X-ray absorptiometry (DXA). MATERIALS AND METHODS: Duplicate BMD measurements were carried out on healthy volunteers (10 men and 10 women) and the Hologic anthropomorphic spine phantom had on the same day before and after placement of following 3 materials in the abdominal area: lard 900 g, 1.5 cm thick; oil 1.4 liters in a vinyl bag; and water 1.2 liters in a vinyl bag. RESULTS: In the case of human participants, following the placement of exogenous water to mimic extracellular fluid (ECF), there was a significant decrease in lumbar spine BMD (-0.012 g/cm2, p=0.006), whereas the placement of exogenous lard and oil to mimic abdominal fat produced a slight increase in lumbar spine BMD (0.006 g/cm2, p=0.301; 0.008 g/cm2, p=0.250, respectively). The average percentage of lumbar spine BMD change with and without exogenous lard, oil, and water showed increase of 0.51%, and 0.67%, and decrease of 1.02%, respectively. Using the phantom, BMD decreased with the placement of both lard (-0.002 g/cm2, p=0.699) and water (-0.006 g/cm2, p=0.153); however, there was no difference in BMD after oil placement. CONCLUSION: These results suggest that in cases where changes in fat and ECF volume are similar, ECF exerts a greater influence than fat on DXA lumbar BMD measurements.

The Correlation and Accuracy of Glucose Levels between Interstitial Fluid and Venous Plasma by Continuous Glucose Monitoring System / 당뇨병

BACKGROUND: Clinical experience with the continuous glucose monitoring systems (CGMS) is limited in Korea. The objective of this study is to evaluate the accuracy of the CGMS and the correlation between interstitial fluid and venous plasma glucose level in Korean healthy male subjects. METHODS: Thirty-two subjects were served with glucose solution contained same amount of test food's carbohydrate and test foods after separate overnight fasts. CGMS was performed over 3 days during hopitalization for each subjects. Venous plasma glucose measurements were carried out during 4 hours (0, 0.25, 0.5, 0.75, 1, 2, 4 hours) just before and after glucose solution and test food load. The performance of the CGMS was evaluated by comparing its readings to those obtained at the same time by the hexokinase method using the auto biochemistry machine (Hitachi 7600-110). Also, correlations between glucose recorded with CGMS and venous plasma glucose value were examined. RESULTS: CGMS slightly underestimated the glucose value as compared with the venous plasma glucose level (16.3 +/- 22.2 mg/dL). Correlation between CGMS and venous plasma glucose values throughout sensor lifetime is 0.73 (regression analysis: slope = 1.08, intercept = 8.38 mg/dL). Sensor sensitivity can deteriorate over time, with correlations between venous blood glucose and CGMS values dropping from 0.77 during 1st day to 0.65 during 2nd and 3rd day. CONCLUSION: The accuracy of data provided by CGMS may be less than expected. CGMS sensor sensitivity is decreased with the passage of time. But, from this study, CGMS can be used for glucose variability tendency monitoring conveniently to the Korean.

Relationship between Serum N-Terminal Pro-Brain Natriuretic Peptide Level and Left Ventricular Dysfunction and Extracellular Water in Continuous Ambulatory Peritoneal Dialysis Patients

This study inquired the relationship between serum N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and left ventricular (LV) dysfunction and extracellular water in continuous ambulatory peritoneal dialysis (CAPD) patients. We conducted a cross-sectional study of 30 CAPD patients. Each patient was admitted to the department of internal medicine, Chosun University Hospital between February and October, 2006. Echocardiography was performed using HDI 5000, allowing M-mode, two-dimensional measurement. A multifrequency bioimpedance analyzer was used; extracellular water was calculated as a percentage of total body water and was understood as the index of volume load of CAPD patients. The mean age was 47+/-12 years. Underlying causes of renal failure were 14 with diabetes mellitus, 7 with hypertension, and 9 with chronic glomerulonephritis. The mean serum NT-proBNP level was 14236.56 (83-35,000) pg/mL. LV mass index and LV ejection fraction were 151.67+/-42.5 g/m2 and 57.48+/-12.9%, respectively. The mean extracellular water was 35.97+/-1.04%. Serum NT-proBNP levels correlated positively with LV mass index (r=0.768, p=0.01) and extracellular water (r=0.866, p=0.01) and negatively with LV ejection fraction (r= -0.808, p=0.01). Serum NT-proBNP levels significantly correlated with LV mass index, LV ejection fraction, and extracellular water. Therefore, serum NT-proBNP levels can be a clinical predictive marker for LV hypertrophy, LV dysfunction, and volume status in CAPD patients.

Change of Body Composition Analyzed by Bioelectrical Impedance Analysis (BIA) in Renal Transplant Recipients / 대한신장학회지

PURPOSE: To investigate the changes of body fluid status after kidney transplantation (KT) and to find out the associated factors. METHODS: Forty-five patients who had received KT were classified into hemodialysis (n=32), peritoneal dialysis (n=5), and preemptive (n=8) groups by dialysis modality. %TBW, %ECF, %ICF, and edema index which were examined by bioelectrical impedance analysis as well as clinical parameters were prospectively measured before KT and 1st month, 3rd month, 6th month after KT. RESULTS: Before KT, there were no significant differences in all of the parameters listed above among the three groups. Mean %TBW and %ICF were not different compared to those of before KT. In contrast, mean %ECF markedly decreased within 1st month (before KT 21.13+/-3.04 L/kg, 1st month 20.03+/-2.37 L/kg, 3rd month 19.61+/-2.18 L/kg, 6th month 18.32+/-5.02 L/kg: p=0.007, p<0.001, p=0.001, respectively). Edema index also decreased from 1st month (1st month 0.354+/-0.014, 3rd month 0.352+/-0.011, 6th month 0.348+/-0.014: p=0.016, p=0.012, respectively). Only edema index was higher at 1st and 3rd month in hemodialysis group. Serum creatinine and 24 hour urine total protein were positively correlated with %ECF at 1st and 3rd month, and with %TBW at 3rd month. CONCLUSION: The recovery of body water distribution after KT starts with reduction of ECF within the 1st month. Serum creatinine and proteinuria are related to the recovery. No significant difference according to dialysis modality was found. Further study with larger sample size is necessary to confirm these findings.

Effects of pH on Vascular Tone in Rabbit Basilar Arteries

Effects of pH on vascular tone and L-type Ca2+ channels were investigated using Mulvany myograph and voltage-clamp technique in rabbit basilar arteries. In rabbitbasilar arteries, high K+ produced tonic contractions by 11+/-0.6 mN (mean+/-S.E., n=19). When extracellular pH (pHo) was changed from control 7.4 to 7.9 ([alkalosis]o), K+-induced contraction was increased to 128+/-2.1% of the control (n=13). However, K+-induced contraction was decreased to 73+/-1.3% of the control at pHo 6.8 ([acidosis]o, n=4). Histamine (10 micrometer) also produced tonic contraction by 11+/-0.6 mN (n=17), which was blocked by post-application of nicardipine (1 micrometer). [alkalosis]o and [acidosis]o increased or decreased histamine-induced contraction to 134+/-5.7% and 27+/-7.6% of the control (n=4, 6). Since high K+- and histamine-induced tonic contractions were affected by nicardipine and pHo, the effect of pHo on voltage-dependent L-type Ca2+ channel (VDCCL) was studied. VDCCL was modulated by pHo: the peak value of Ca2+ channel current (IBa) at a holding of 0 mV decreased in [acidosis]o by 41+/-8.8%, whereas that increased in [alkalosis]o by 35+/-2.1% (n=3). These results suggested that the external pH regulates vascular tone partly via the modulation of VDCC in rabbit basilar arteries.

Microdialysis and its application in neurointensive care / 医学研究生学报

Microdialysis, a technique for sampling the biochemical substances of extracellular fluid in vivo, has been widely utilized for physiological, pharmacological and pathological research. The principles and methodology of microdialysis and its applications in neurointensive care was reviewed.

Fluid distribution abnormalities and influence of hemodialysis on fluid distribution in patients on maintenance hemodialysis / 北京大学学报(医学版)

Objective: To study the fluid distribution abnormalities in patients on hemodialysis and fluid shift between intracellular and extracellular compartment during hemodialysis (HD).Methods: Eighty stable end stage renal disease patients on maintenance hemodialysis were selected. Conventional low flux dialyses at dialysate sodium concentration of 138 mmoL/L were performed for all of the patients. Fresenius polysulphons or Gambro hemophon dialyzers were used. All of the patients showed no clinical signs of over ultrafiltration during HD sessions and dry body weights were considered adequate. Intracellular water (ICW), extracellular water (ECW) and total body water (TBW) were measured and standardized by body weight (nICW, nECW, nTBW) before and after HD sessions. Sixty-seven cases of sex, age and body weight matched normal individuals were used as controls. Bio-impedance spectrum (BIS) analysis (Xitron, Technolo gies, San Diego, CA, USA) was used in body fluid measurement. Pre and post HD nICW, nECW, and nTBW were compared with these of the controls.Results: There were no differences in age, post-dialysis body weight and body mass index between patients on hemodialysis and the controls. Patients on hemodialysis had less nICW [male (0.28?0.05) vs (0.33?0.04), P

Changes of extracellular and intracellular free amino acid levels in patients with chronic renal failure / 中华肾脏病杂志

Objective To investigate the extracellular and intracellular free amino acid concentrations in healthy subjects and its changes in chronic renal failure(Car) .Methods The free amino acid concentrations in the plasma, in the erythrocytes and in the skeletal muscle of 15 patients with CRF were compared with those in ten healthy subjects.Results In healthy subjects, there was little ~difference between the concentrations in erythrocytes and in plasma for most amino acids; but in ~erythrocytes the concentrations of Asp, Glu, Ser were higher than those in plasma (P