A Compressed-Sensing Based Blind Deconvolution Method for Image Deblurring in Dental Cone-Beam Computed Tomography.

In cone-beam computed tomography (CBCT), reconstructed images are inherently degraded, restricting its image performance, due mainly to imperfections in the imaging process resulting from detector resolution, noise, X-ray tube's focal spot, and reconstruction procedure as well. Thus, the recovery of CBCT images from their degraded version is essential for improving image quality. In this study, we investigated a compressed-sensing (CS)-based blind deconvolution method to solve the blurring problem in CBCT where both the image to be recovered and the blur kernel (or point-spread function) of the imaging system are simultaneously recursively identified. We implemented the proposed algorithm and performed a systematic simulation and experiment to demonstrate the feasibility of using the algorithm for image deblurring in dental CBCT. In the experiment, we used a commercially available dental CBCT system that consisted of an X-ray tube, which was operated at 90 kVp and 5 mA, and a CMOS flat-panel detector with a 200-µm pixel size. The image characteristics were quantitatively investigated in terms of the image intensity, the root-mean-square error, the contrast-to-noise ratio, and the noise power spectrum. The results indicate that our proposed method effectively reduced the image blur in dental CBCT, excluding repetitious measurement of the system's blur kernel.

Higher risk of hepatocellular carcinoma in chronic hepatitis B vs chronic hepatitis C after achievement of virologic response.

It is unclear whether the achievement of virologic response modifies the risk of hepatocellular carcinoma (HCC) differently in chronic hepatitis B (CHB) and chronic hepatitis C (CHC). Our aim was to compare the risk of HCC between patients with CHB and CHC who achieved virological response. We analysed data from patients with CHB treated with entecavir (n=2000) or CHC treated with peg-interferon and ribavirin (n=733) at a tertiary hospital from 2004 to 2011. Virological response was defined as serum HBV DNA<15 IU/mL at 1 year of treatment for CHB or the achievement of sustained virologic response for CHC. Virological response was achieved in 1520 patients with CHB (76.0%) and 475 patients with CHC (64.8%). During the median follow-up period of 6 years, 228 patients with CHB (11.4%) and 59 patients with CHC (8.0%) developed HCC. Among patients with virological response, CHB was independently associated with a significantly higher incidence of HCC (hazard ratio, 2.17; 95% CI, 1.30-3.63; P=.003) than CHC. Among patients without virological response, there were no differences in HCC incidence between the two cohorts (P=.52). In patients with cirrhosis at baseline, the incidence of HCC did not differ between the two cohorts even after achieving virological response (P>.99). In conclusion, patients with CHB treated with entecavir were associated with a higher risk of HCC compared to patients with CHC treated with peg-interferon and ribavirin after achieving virological response. However, the risk of HCC did not differ between the two cohorts if the patients had cirrhosis at baseline, even if virological response was achieved.

Radiofrequency ablation as an alternative to hepatic resection for single small hepatocellular carcinomas.

BACKGROUND: This study aimed to investigate whether radiofrequency ablation (RFA) is an alternative to surgical resection for hepatocellular carcinoma (HCC) within the context of current guidelines. METHODS: This retrospective study included patients with normal portal pressure and serum bilirubin level who initially underwent liver resection or RFA for a single HCC of maximum size 3 cm. Between-group differences in cumulative rates of survival and recurrence specific for HCC were analysed in the entire cohort and in a propensity score-matched cohort. RESULTS: A total of 604 patients were enrolled, 273 in the liver resection group and 331 in the RFA group. The 5- and 10-year HCC-specific survival rates for the resection and RFA groups were 87·6 versus 82·1 per cent and 59·0 versus 61·2 per cent respectively (P = 0·214), whereas overall 5- and 10-year recurrence-free survival rates for the corresponding groups were 60·6 versus 39·4 per cent and 37·5 versus 25·1 per cent respectively (P < 0·001). In the propensity score-matched cohort (152 pairs), there were no differences in HCC-specific survival (hazard ratio (HR) 1·03 for RFA versus resection; P = 0·899), whereas recurrence-free survival again differed between the treatment groups (HR 1·75; P < 0·001). RFA was independently associated with poorer outcomes in terms of treatment-site recurrence-free survival (adjusted HR 1·66; P = 0·026), but not non-treatment-site recurrence-free survival (adjusted HR 1·15; P = 0·354). CONCLUSION: Although RFA carries a higher risk of treatment-site recurrence than hepatic resection, it provides comparable overall survival in patients with a single small HCC without portal hypertension or a raised bilirubin level.

The effects of canthaxanthin on porcine oocyte maturation and embryo development in vitro after parthenogenetic activation and somatic cell nuclear transfer.

The objective of this study was to examine the effects of canthaxanthin (Cx) treatment during in vitro maturation (IVM) of porcine oocytes on embryonic development after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT), on intracellular glutathione (GSH) and reactive oxygen species (ROS) levels in mature oocytes, and on gene expression in both PA- and SCNT-derived blastocysts. To determine the optimal effective concentration of Cx, porcine oocytes were cultured in IVM medium supplemented with various concentrations (0, 20, 40 and 80 µM) of Cx for 22 hr. Compared to other groups, supplementation with 40 µM Cx significantly improved blastocyst formation rates after PA (p < .05), but no significant differences were observed among groups in total blastocyst cell numbers. Subsequently, oocytes were cultured in IVM medium supplemented with or without 40 µM Cx. Oocytes treated with 40 µM Cx showed significantly increased cleavage and blastocyst formation rates after SCNT compared to the control group (p < .05). Moreover, significantly increased intracellular GSH and reduced ROS levels were observed in the Cx-treated group (p < .05). In addition, both PA- and SCNT-derived blastocysts from the 40 µM Cx-treated group showed significantly increased mRNA expression of Bcl2 and Oct4 and decreased Caspase3 expression level (p < .05), when compared with the control group. PA-derived blastocysts from the 40 µM Cx-treated group also exhibited significantly decreased expression of Bax (p < .05). Our results demonstrated that treatment with 40 µM Cx during IVM improves the developmental competence of PA and SCNT embryos. Improvement of embryo development by Cx is most likely due to increased intracellular GSH synthesis, which reduces ROS levels in oocytes, and it may also positively regulate apoptosis- and development-related genes.

[Effect of S-amlodipine nicotinate on the cerebral circulation in rats under conditions of ischemic and hemorrhagic brain injury].

We have performed a comparative study of the effects of S-amlodipine nicotinate and nimodipine on the local cerebral blood flow were studied in intact rats and those with model ischemic and hemorrhagic brain injury. It is established that S-amlodipine nicotinate produces a somewhat more pronounced enhancement of cerebral blood flow in rats with ischemic and hemorrhagic brain injury than in intact animals. In addition, S-amlodipine nicotinate significantly exceed nimodipine with respect to cerebrovascular activity in rats with brain pathology of both ischemic and hemorrhagic nature.

[Comparative study of the effect of S-amlodipine nicotinate and amlodipine benzylate on the arterial pressure of awake rats].

We have performed a comparative study of the effects of two calcium channel blockers, S-amlodipine nicotinate and amnlodipine benzylate, on the arterial pressure (AP) of awake rats measured in the tail artery. The results of experiments showed that both preparations produce a statistically significant long-term decrease in the AP of animals. In respect of both strength and duration of the hypotensive effect, S-amlodipine nicotinate somewhat exceeds amnlodipine benzylate.

Species-specific challenges in dog cloning.

Somatic cell nuclear transfer (SCNT) is now an established procedure used in cloning of several species. SCNT in dogs involves multiple steps including the removal of the nuclear material, injection of a donor cell, fusion, activation of the reconstructed oocytes and finally transfer to a synchronized female recipient. There are therefore many factors that contribute to cloning efficiency. By performing a retrospective analysis of 2005-2012 published papers regarding dog cloning, we define the optimum procedure and summarize the specific feature for dog cloning.

Lessons learned from cloning dogs.

The aim of this article is to review dog cloning research and to suggest its applications based on a discussion about the normality of cloned dogs. Somatic cell nuclear transfer was successfully used for production of viable cloned puppies despite limited understanding of in vitro dog embryo production. Cloned dogs have similar growth characteristics to those born from natural fertilization, with no evidence of serious adverse effects. The offspring of cloned dogs also have similar growth performance and health to those of naturally bred puppies. Therefore, cloning in domestic dogs can be applied as an assisted reproductive technique to conserve endangered species, to treat sterile canids or aged dogs, to improve reproductive performance of valuable individuals and to generate disease model animals.

Eliminating artifacts in single-grid phase-contrast x-ray imaging for improving image quality.

In this study, we propose a modification to a single-grid phase-contrast x-ray imaging (PCXI) system using a Fourier domain analysis technique to extract absorption, scattering, and differential phase-contrast images. The proposed modification is to rotate the x-ray grid in the image plane to achieve spectral separation between the desired information and the moiré artifact, which is introduced by the superposition of the periodic image of the grid shadow and the periodic sampling by the detector. In addition, we performed some system optimization by adjusting distances between source, object, grid, and detector to further improve image quality. This optimization aimed to increase the spectral spacing between the primary spectrum (lower frequency) and the harmonics of the spectrum (higher frequency) used to extract the various image contrasts. The table-top setup used in the experiment consisted of a focused-linear grid with a 200-lines/inch strip density, a microfocus x-ray tube with a 55-µm focal spot size, and a CMOS flat-panel detector with a 49.5-µm pixel size. The x-ray grid was rotated at 27.8° with respect to the detector and the sample was placed as close as possible to the x-ray tube. Our results indicated that the proposed method effectively eliminated the PCXI artifacts, thus improving image quality.

Supplementation with spermine during in vitro maturation of porcine oocytes improves early embryonic development after parthenogenetic activation and somatic cell nuclear transfer.

Spermine plays an important role in protection from reactive oxygen species (ROS) in bacteria, yeast, and mammalian cells, but there are few studies on the effects of spermine on porcine oocyte maturation and subsequent embryo development. The aim of this study was to determine the effects of spermine on in vitro maturation (IVM) of porcine oocytes and their developmental competence after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT). We evaluated nuclear maturation, intracellular glutathione (GSH), and ROS levels in oocytes, and their subsequent embryonic development, as well as gene expression in mature oocytes, cumulus cells, and PA blastocysts. After treatment with various concentrations of spermine in IVM culture medium, there was no significant difference in nuclear maturation rate. However, spermine treatment groups (10- 500 µM) showed significantly increased intracellular GSH levels and decreased ROS levels compared to the control ( < 0.05). Furthermore, 10 µM spermine supported significantly higher blastocyst formation rates after PA than the control group ( < 0.05). According to the optimal condition from the PA results, we investigated the effects of 10 µM spermine on SCNT, and it also significantly improved blastocyst formation rates compared with the control group ( < 0.05). In evaluating the effects of 10 µM spermine on gene expression, there was significantly lower expression of a proapoptotic gene () and higher expression of an antiapoptotic gene () in cumulus cells ( < 0.05). was increased in spermine-treated oocytes. Levels of transcription for and were significantly increased in PA blastocysts. In conclusion, 10 µM spermine supplementation during IVM improved the development of porcine PA and SCNT embryos by increasing intracellular GSH, scavenging ROS levels, and regulating gene expression.

3D reconstruction based on compressed-sensing (CS)-based framework by using a dental panoramic detector.

In this work, we propose a practical method that can combine the two functionalities of dental panoramic and cone-beam CT (CBCT) features in one by using a single panoramic detector. We implemented a CS-based reconstruction algorithm for the proposed method and performed a systematic simulation to demonstrate its viability for 3D dental X-ray imaging. We successfully reconstructed volumetric images of considerably high accuracy by using a panoramic detector having an active area of 198.4 mm × 6.4 mm and evaluated the reconstruction quality as a function of the pitch (p) and the angle step (Δθ). Our simulation results indicate that the CS-based reconstruction almost completely recovered the phantom structures, as in CBCT, for p≤2.0 and θ≤6°, indicating that it seems very promising for accurate image reconstruction even for large-pitch and few-view data. We expect the proposed method to be applicable to developing a cost-effective, volumetric dental X-ray imaging system.

Clinical characteristics of responders to intravitreal bevacizumab in central serous chorioretinopathy patients.

PURPOSE: To investigate factors associated with good response to intravitreal bevacizumab (IVB) in central serous chorioretinopathy (CSC) patients. METHODS: We retrospectively reviewed 42 eyes of CSC patients of symptom duration more than 3 months who received a single or multiple successive IVBs on an as-needed basis (0.05 ml, 1.25 mg). High responders (HRs) were defined as complete resolution of subretinal fluid (SRF) on spectral domain optical coherence tomography (SD-OCT). Moderate responders (MRs) were defined as SRF resolution of 50-99% of pretreatment volume and poor responders (PRs) as SRF resolution <50%. Clinical, SD-OCT, fluorescein, and indocyanine green angiography findings were analyzed to find factors associated with HR. Descriptive statistics for all demographic and clinical variables were calculated, and comparisons were made using Wilcoxon's matched-pairs signed-rank test, the Mann-Whitney U-test for means with continuous data, Pearson's χ(2) test, and Fisher's exact test for categorical data. RESULTS: The mean number of IVB was 1.9. At postoperative 1 month, there were 10 (24%) HRs, 18 (43%) MRs, and 14 (33%) PRs. At the last follow-up (the mean 8.6 months), there were 25 HRs (60%), 9 MRs (21%), and 8 PRs (19%). Thicker subfoveal choroid (P=0.036), smaller lesion diameter (P=0.019), and better baseline best-corrected visual acuity (P=0.002) predicted HRs at postoperative 1 month. HR at the last follow-up was associated with classic pattern fluorescein angiography finding. CONCLUSIONS: Suboptimal effects of IVB on persistent CSC suggest primary IVB on selective cases with better vision, smaller lesion, and thicker choroid at baseline.

Effect of dialysis modalities on gastric myoelectrical activity in end-stage renal disease patients.

Gastric motility is controlled by gastric myoelectrical activity, which propagates from the proximal body to the distal antrum at a frequency of 3 cycles/min. In uremic patients, dyspeptic symptoms are common. To investigate whether dialysis modality affects gastric myoelectrical activity in uremic patients, we performed electrogastrography (EGG) in 41 patients without diabetes with end-stage renal disease (ESRD) undergoing hemodialysis (HD; n = 22) and continuous ambulatory peritoneal dialysis (CAPD; n = 19). EGG was performed noninvasively using abdominal surface electrodes in the fasting state before and 4 hours after HD and at empty and 2 hours after CAPD with 2,000 mL of dialysate. There were no significant differences in age, sex, body weight, duration of dialysis, and percentage of patients with upper gastrointestinal (UGI) symptoms (63.6% versus 42.1%). CAPD patients had significantly lower serum albumin levels (3.4 +/- 0.4 versus 3.9 +/- 0.4 g/dL; P < 0.05), greater serum total-cholesterol levels (189 +/- 33 versus 157 +/- 36 mg/dL; P: < 0.05), and greater percentages of patient with early satiety (42.1% versus 13.6%; P < 0.05) than HD patients. Dominant power significantly increased after HD (251.3 +/- 157.5 versus 512.9 +/- 390.0 dB; P < 0.05) but seemed to decrease after CAPD without statistical significance (416.2 +/- 323.6 versus 283.8 +/- 280.7 dB). There was no difference in the normal slow-wave frequency (NSWF) between HD and CAPD patients (predialysis, 60.7% +/- 29.3% versus 52.2% +/- 36.7%; postdialysis, 56.3% +/- 32.0% versus 50.9% +/- 34.2%). Tachygastria significantly increased after CAPD (pre-CAPD, 2.35% +/- 4.3% versus post-CAPD, 10.0% +/- 14.8%; P < 0.05). There was a significant correlation between changes in tachygastria after CAPD and grade of early satiety in CAPD patients with UGI symptoms (r = 0.74; P: < 0.05). Changes in NSWF after CAPD significantly correlated with age (r = -0.51; P: < 0.05). In conclusion, dialysis modalities seem to have different effects on gastric myoelectrical activity in patients with ESRD.

Clinical outcomes of immediate full-volume exchange one year after peritoneal catheter implantation for CAPD.

OBJECTIVE: To evaluate actual risk of complications and 1-year catheter survival of immediate full-volume 2000-mL dialysate exchange after peritoneal catheter implantation. DESIGN AND SETTING: A prospective randomized comparative study in a university hospital kidney center. PATIENTS: The study included 59 end-stage renal disease patients entering into a continuous ambulatory peritoneal dialysis program between January 1996 and December 1997. INTERVENTIONS: In group 1 (n = 21), exchange volume was gradually increased from 500 mL per 3 hours to full-volume exchange over 13 days. In group 2 (n = 38), full-volume exchange per 6 hours was performed from the day of catheter implantation. Bed rest with minimal activity was recommended for the first 3 days in both groups. MAIN OUTCOME MEASURES: Occurrence of catheter-related complications such as dialysate leakage, drainage failure, malposition, infectious complications, and, ultimately, catheter loss were observed for 1 year. RESULTS: After straight Tenckhoff catheter implantation, pericatheter dialysate leaks occurred in 9.5% of group 1 and in 10.5% of group 2 patients (no significance, NS). Within 1 month of implantation, the incidences of tunnel or exit-site infection, catheter malposition, and outflow failure were not significantly different between the two groups. Abdominal discomfort was noted in 2 patients from group 2. Peritonitis occurred in 9.5% and 5.3% (NS) within 2 weeks of catheter implantation, and in 14.3% and 10.5% (NS) after more than 2 weeks in group 1 and group 2, respectively. Early catheter loss within 1 month occurred in 4.8% of patients in group 1 and 5.3% in group 2 (NS). The causes of loss were persistent leakage in group 1, and persistent leakage combined with tunnel infection and outflow failure in group 2. The duration of hospitalization from the day of catheter insertion to discharge was definitely shorter in group 2 compared to group 1 (9.9 +/-0.6 days vs 15.0 +/- 0.8 days, p < 0.001). For 1-year follow-up, the frequencies of peritonitis were 0.062 +/- 0.015/patient-month in group 1 and 0.076 +/- 0.018/patient-month in group 2 (NS). The actual 1-year catheter survival was 85.7% in group 1 and 84.2% in group 2 (NS). CONCLUSIONS: One-year catheter survival after immediate full-volume peritoneal dialysis exchange was 84.2%. This study did not show any evidence that immediate full-volume exchange causes more short- or long-term complications compared to the stepwise volume increment method.

Measurement of fluid shift in CAPD patients using segmental bioelectrical impedance analysis.

OBJECTIVE: To determine, using segmental bioelectrical impedance analysis (BIA), the characteristics of fluid shift of each body segment in continuous ambulatory peritoneal dialysis (CAPD) patients during and after peritoneal dialysis (PD) solution exchange. DESIGN: Observational study with repeated measurements of bioelectrical impedance, which is inversely related to tissue fluid content. PATIENTS: Thirteen clinically stable CAPD patients. METHODS: Bioelectrical impedance was measured at frequencies of 5, 50, 250, and 500 kHz in each body segment four times: (1) before and (2) after drainage of dialysate, and (3) at 1 hour and (4) at 2 hours after exchange of new 1.5% dextrose PD solution. RESULTS: Impedance of both arms was significantly increased at 1 hour post exchange at all frequencies. In the trunk, impedance at all frequencies increased significantly after drainage, decreased significantly at 1 hour post exchange, and then increased again for the next hour without significance. Impedance of both legs showed a decreasing tendency at all frequencies during and after exchange. Net calculated water volume changes between the time before drainage and 2 hours post exchange were -0.5 L in the trunk, -0.25 L in both arms, +0.47 L in both legs, -0.28 L in total. The change in body weight between the time before drainage and 2 hours post exchange was -0.21 kg, on average, and significantly correlated with total net calculated water volume change (p = 0.009). CONCLUSIONS: Each body segment of the CAPD patient has its own characteristic pattern of fluid shift in response to PD solution exchange or dwell. Segmental BIA may be a useful tool for understanding the physiological changes in fluid shift in CAPD patients.

Effect of peritoneal glucose load on plasma leptin concentration in continuous ambulatory peritoneal dialysis patients.

This study was performed to investigate the effect of peritoneal glucose load on plasma leptin concentrations in the continuous ambulatory peritoneal dialysis (CAPD) performed on 13 non-diabetic ESRD patients. Plasma leptin and insulin concentrations were measured for 2 hours during a single 2 liter exchange of 1.5% glucose-based dialysate (SPD, n = 6), for 7 days of daily peritoneal dialysis (DPD, n = 7). In DPD, standard full volume (2,000 ml x 4 times/day) exchange was performed immediately after operation. In SPD, plasma leptin and insulin concentrations remained unchanged during the study. In DPD, the plasma leptin concentration increased significantly after CAPD on the first day (PD1) (11.2 +/- 5.4 to 17.0 +/- 6.0 ng/mL, p < 0.05) and this elevation seemed to persist until 7 days after operation. After CAPD, there was no significant day-to-day variation in peritoneal glucose absorption (391-465 cal). Oral intake seemed to decrease on operation day (PD0) and PD1 and then increased slowly. Plasma insulin and glucose concentrations did not significantly change after CAPD. Changes of leptin concentration were significantly correlated with the changes of peritoneal glucose absorption at PD1. In conclusion, continuous peritoneal glucose load may affect plasma leptin concentrations in CAPD patients.

A case of living-related kidney transplantation in Bartter's syndrome.

Bartter's syndrome is a renal tubular disorder characterized by hypokalemia, metabolic alkalosis, increased urinary excretion of potassium and prostaglandins, a relative vascular resistance to the pressor effects of exogenous angiotensin II, and hyperplasia of the juxtaglomerular apparatus. In most patients, the glomerular filtration rate is normal and chronic renal failure does not develop. We report here on a case of living-related kidney transplantation in Bartter's syndrome, in which a non-steroidal anti-inflammatory drug is suspected to be the cause of the end-stage renal disease.

The influence of seasonal factors on the incidence of peritonitis in continuous ambulatory peritoneal dialysis in the temperate zone.

Many factors contribute to the development of continuous ambulatory peritoneal dialysis (CAPD) peritonitis. The role of climate in CAPD peritonitis has received relatively little attention. We retrospectively analyzed the incidence of CAPD peritonitis according to temperature and relative humidity. Data from 80 patients were examined. The monthly mean temperature and relative humidity during study period varied between -3.4 degrees C and 25.4 degrees C and between 61% and 81%, respectively. In 1123 patient-months, 53 cases of peritonitis occurred. The occurrence of peritonitis paralleled temperature and relative humidity, being the highest (0.180 episodes/patient-month) in July (mean temperature, 24.6 degrees C; relative humidity, 81%) and lowest (0.013 episodes/patient-month) in November (mean temperature, 6.6 degrees C; relative humidity, 66%). Significant correlations were seen between the monthly frequency of CAPD peritonitis and temperature (r = 0.53, p < 0.05) and relative humidity (r = 0.59, p < 0.05). The incidence was higher in the warm season (months with a mean temperature > or = 15 degrees C, that is, May-September) than in the cold season (months with a mean temperature < 15 degrees C, that is, October-April), at 0.074 episodes/patient-month versus 0.024 episodes/patient-month, p < 0.05. We also found a tendency for gram-negative peritonitis to occur uniformly throughout the year, but for gram-positive peritonitis to increase during hot and humid months, especially the rainy month of July. Gram-positive organisms caused 50% of peritonitis from March to August, but just 17.7% from September to February. Gram-negative organisms caused 7.3% and 29.4% of peritonitis during the same periods (p < 0.05). The results indicate a clear seasonal change in the rate of CAPD peritonitis and in the causative micro-organisms. The observation that CAPD peritonitis increases in the season of high temperature and high humidity suggests the influence of climate on CAPD peritonitis in the temperate zone.

Effectiveness of slow freezing and vitrification for long-term preservation of mouse ovarian tissue.

This study was conducted to evaluate the interaction between cryo-damage and ART outcome after cryopreservation of mouse ovarian tissues with different methods. Either a vitrification or a slow freezing was employed for the cryopreservation of B6CBAF1 mouse ovaries and follicle growth and the preimplantation development of intrafollicular oocytes following parthenogenesis or IVF were monitored. Both cryopreservation protocols caused significant damage to follicle components, including vacuole formation and mitochondrial deformities. Regardless of the cryopreservation protocols employed, a sharp (P < 0.0001) decrease in follicle viability and post-thaw growth was detected. When IVF program was employed, significant (P < 0.05) decrease in cleavage and blastocyst formation was notable in both modes of cryopreservation. However, such retardation was not found when oocytes were parthenogenetically activated. In the IVF oocytes, slow freezing led to better development than vitrification. In conclusion, a close relationship between cryopreservation and ART methods should be considered for the selection of cryopreservation program.

Assessment of total body water from anthropometry-based equations using bioelectrical impedance as reference in Korean adult control and haemodialysis subjects.

BACKGROUND: Several indirect prediction equations to estimate total body water (TBW) with simple demographic and anthropometric data are commonly used by researchers and dialysis units. These equations are largely based on observations in subjects of the Western hemisphere. The purpose of this study was to investigate the possible application of anthropometry-based TBW equations to a Korean adult control population and maintenance haemodialysis (HD) patients using multifrequency bioelectrical impedance analysis (BIA) as reference. METHODS: We performed BIA and anthropometric measurements in 67 healthy adults and 101 HD patients. Four anthropometry-based equations were used: 58% of actual body weight (TBW-58), the Watson formula (TBW-W), the Hume formula (TBW-H), and the Chertow formula (TBW-C). Multifrequency BIA was performed at fasting state in controls and after HD. RESULTS: TBW-BIA was 34.6+/-6.9 l in control and 29.9+/-5.1 l in HD patients. TBW-58 and TBW-C gave significantly greater TBWs than TBW-BIA in both control and HD subjects. The correlation coefficients of TBW-BIA with calculated TBWs were lowest in TBW-58 (0.754 in control and 0.856 in HD subjects), and highest in TBW-C (0.944 in control and 0.916 in HD subjects). Mean prediction error was greatest in the Chertow formula for control and HD patients. Mean prediction error, limits of agreement, and root mean square error were lowest between TBW-BIA and TBW-H in control and between TBW-BIA and TBW-W in HD subjects. The correlation coefficient in the Bland-Altman plot was closer to zero and parallel with TBW-W than TBW-H in control and HD subjects. CONCLUSION: Currently available TBW equations overestimate TBW in both Korean normal control subjects and HD patients. Among them, the Watson formula appears to be the closest to TBW and to have the least bias. Based on this analysis, it is reasonable to use the Watson formula for the calculation of TBW in Korean adult control and HD subjects until an Asian-based TBW equation is available.