Artificial-Intelligence-Assisted Detection of Metastatic Colorectal Cancer Cells in Ascitic Fluid

Ascites cytology is a cost-effective test for metastatic colorectal cancer (CRC) in the abdominal cavity. However, metastatic carcinoma of the peritoneum is difficult to diagnose based on biopsy findings, and ascitic aspiration cytology has a low sensitivity and specificity and a high inter-observer variability. The aim of the present study was to apply artificial intelligence (AI) to classify benign and malignant cells in ascites cytology patch images of metastatic CRC using a deep convolutional neural network. Datasets were collected from The OPEN AI Dataset Project, a nationwide cytology dataset for AI research. The numbers of patch images used for training, validation, and testing were 56,560, 7068, and 6534, respectively. We evaluated 1041 patch images of benign and metastatic CRC in the ascitic fluid to compare the performance of pathologists and an AI algorithm, and to examine whether the diagnostic accuracy of pathologists improved with the assistance of AI. This AI method showed an accuracy, a sensitivity, and a specificity of 93.74%, 87.76%, and 99.75%, respectively, for the differential diagnosis of malignant and benign ascites. The diagnostic accuracy and sensitivity of the pathologist with the assistance of the proposed AI method increased from 86.8% to 90.5% and from 73.3% to 79.3%, respectively. The proposed deep learning method may assist pathologists with different levels of experience in diagnosing metastatic CRC cells of ascites.

Erratum: Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande [Phys. Rev. Lett. 130, 031802 (2023)]

This corrects the article DOI: 10.1103/PhysRevLett.130.031802.

Search for Cosmic-Ray Boosted Sub-GeV Dark Matter Using Recoil Protons at Super-Kamiokande

We report a search for cosmic-ray boosted dark matter with protons using the 0.37  megaton×years data collected at Super-Kamiokande experiment during the 1996-2018 period (SKI-IV phase). We searched for an excess of proton recoils above the atmospheric neutrino background from the vicinity of the Galactic Center. No such excess is observed, and limits are calculated for two reference models of dark matter with either a constant interaction cross section or through a scalar mediator. This is the first experimental search for boosted dark matter with hadrons using directional information. The results present the most stringent limits on cosmic-ray boosted dark matter and exclude the dark matter-nucleon elastic scattering cross section between 10^{-33}cm^{2} and 10^{-27}cm^{2} for dark matter mass from 1  MeV/c^{2} to 300  MeV/c^{2}.

Identification of distinct subgroups in moderately severe rheumatic mitral stenosis using data-driven phenotyping of longitudinal hemodynamic progression

Background

Rheumatic mitral stenosis (MS) is a significant cause of valvular heart disease. Pulmonary artery systolic pressure (PASP) reflects the hemodynamic consequences of MS and is used to determine treatment strategies. However, PASP progression and expected outcomes in patients with moderately severe MS remain unclear.

Purpose

We aimed to examine the impact of progression rate of PASP in moderately severe MS.

Methods

A cohort of 866 consecutive patients with moderately severe rheumatic MS (1.0 cm2.

Results

Data-driven phenotyping identified two distinct trajectories based on PASP progression: a rapid progression group (N=38, 8.7%) and a slow progression group (N=398, 91.3%). Patients in the rapid progression group were older and had more comorbidities than patients in the slow progression group, including diabetes, and atrial fibrillation (all P<0.05). The initial mean diastolic pressure gradient and PASP were higher in the rapid progression group than in the slow progression group (6.2±2.4 mmHg vs. 5.1±2.0 mmHg, P=0.001, and 42.3±13.3 mmHg vs. 33.0±9.2 mmHg, P<0.001, respectively). During a mean follow-up of 7.0±3.0 years, the event-free survival rate was significantly lower in the rapid progression group than in the slow progression group (log-rank P<0.001). Rapid PASP progression was a significant risk factor for composite outcomes even after adjusting for comorbidities (hazard ratio: 3.08, 95% confidence interval (CI): 1.68–5.64, P<0.001). Multivariate regression analysis revealed that PASP>40 mmHg was independently associated with the probability of rapid progression group allocation (odds ratio: 4.95, 95% CI: 2.08–11.99, P<0.001).

Conclusions

Two groups with distinct patterns of PASP progression were identified. Rapid PASP progression was associated with a significantly higher risk of the composite outcomes. The main independent echocardiographic predictor for rapid progression group allocation was initial PASP>40 mmHg.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): This study was supported by a Severance Hospital Research fund for Clinical excellence (SHRC) (C-2020-0041) and a faculty research grant of Yonsei University College of Medicine (6-2020-0156).

Prognostic value of liver stiffness in patients with tricuspid regurgitation

Background

It has been known that liver stiffness (LS) assessed by transient elastography is associated with right heart dysfunction and the severity of the tricuspid regurgitation. However, the predictive value of LS for adverse outcome in patients with tricuspid regurgitation (TR) is uncertain.

Objectives

The aim of this study was to identify the prognostic value of LS in patients with moderate or greater degree of TR.

Methods

A total of 257 patients with moderate or severe TR who underwent both echocardiography and liver transient elastography were retrospectively analysed. Patients who have congenital heart disease or chronic liver disease including, viral hepatitis, alcoholic liver disease, autoimmune hepatitis, hepatocellular carcinoma were excluded. Severe LS was defined as elevated kilopascal (kPa) ≥11 (High kPa). Primary outcome was defined as the composite of all-cause death and unplanned admission for heart failure.

Results

One hundred forty-one patients had moderate TR and 116 patients had severe TR. One hundred twenty-eight (50%) patients had severe liver stiffness. During a follow-up period (median 637 days, IQR 1317), 116 (45.1%) primary outcomes occurred. In Kaplan-Meier analysis, patients who had severe TR with high kPa showed the worst outcome. Moreover, patients who had high kPa were associated with worse clinical outcome both moderate TR group and severe TR group than patients with low kPa. In multivariate Cox regression analysis, severe liver stiffness was independently associated with primary outcomes (HR=1.66, 95% CI: 1.28–2.16), p<0.001).

Conclusions

LS is independently associated with adverse clinical outcomes in both patients with moderate and severe TR. The degree of liver fibrosis measured by transient elastography may be a useful marker of cardiac hepatopathy related to TR, and this may contribute to predict the prognosis of TR.

Funding Acknowledgement

Type of funding sources: None.

Risk factors for overcorrection of severe hyponatremia: a post hoc analysis of the SALSA trial

Background

Hyponatremia overcorrection can result in irreversible neurologic impairment such as osmotic demyelination syndrome. Few prospective studies have identified patients undergoing hypertonic saline treatment with a high risk of hyponatremia overcorrection.

Methods

We conducted a post hoc analysis of a multicenter, prospective randomized controlled study, the SALSA trial, in 178 patients aged above 18 years with symptomatic hyponatremia (mean age, 73.1 years; mean serum sodium level, 118.2 mEq/L). Overcorrection was defined as an increase in serum sodium levels by >12 or 18 mEq/L within 24 or 48 hours, respectively.

Results

Among the 178 patients, 37 experienced hyponatremia overcorrection (20.8%), which was independently associated with initial serum sodium level (≤110, 110–115, 115–120, and 120–125 mEq/L with 7, 4, 2, and 0 points, respectively), chronic alcoholism (7 points), severe symptoms of hyponatremia (3 points), and initial potassium level (<3.0 mEq/L, 3 points). The NASK (hypoNatremia, Alcoholism, Severe symptoms, and hypoKalemia) score was derived from four risk factors for hyponatremia overcorrection and was significantly associated with overcorrection (odds ratio, 1.41; 95% confidence interval, 1.24–1.61; p < 0.01) with good discrimination (area under the receiver-operating characteristic [AUROC] curve, 0.76; 95% CI, 0.66–0.85; p < 0.01). The AUROC curve of the NASK score was statistically better compared with those of each risk factor.

Conclusion

In treating patients with symptomatic hyponatremia, individuals with high hyponatremia overcorrection risks were predictable using a novel risk score summarizing baseline information.

Differential characteristics associated with progression of mitral and aortic regurgitation in patients undergoing kidney transplantation

Background

Heart valve regurgitation is common in patients with end-stage renal disease (ESRD). However, there are no data on the fate of mitral regurgitation (MR) and aortic regurgitation (AR) after kidney transplantation (KT). In this study, we sought to investigate regression or progression rates of MR and AR after KT in patients with ESRD. Moreover, we aimed to explore clinical and echocardiographic factors associated with the progression of MR and AR in patients undergoing KT.

Methods

Among 1,734 patients who underwent KT from 2005 to 2018 at a single tertiary hospital, 674 patients (407 men; mean 48±12 years) who underwent both pre- and post-KT echocardiography were analyzed comprehensively. Pre-KT echocardiography was performed within three months of KT, and post-KT echocardiography was done between 6 months and 24 months after KT. Severities of MR and AR were graded as no/trivial, mild, moderate, and severe according to the current guidelines. Regression was defined if the severity decreased by one or more grades, while progression was defined if the severity increased by one or more grades.

Results

Figure 1 shows the regression or progression of MR and AR after KT. 78 (11%) patients showed MR regression, but 41 (6%) experienced MR progression. 13 (2%) revealed AR regression, while 23 (4%) presented AR progression. In patients with MR progression, there were more cases of receiving a second KT, having mitral annular calcification, and showing lesser reduction of left atrial volume after KT. Patients with AR progression showed a longer hemodialysis duration, persistent hypertension after KT, and aortic root dilatation. Factors related to the progression of MR and AR showed statistically meaningful predictive values in a stepwise manner (Figure 2)

Conclusions

In patients undergoing KT, MR and AR may progress in patients with certain distinct characteristics. Different clinical and echocardiographic characteristics before KT, and reduction of hemodynamic loads after KT determine the progression of MR and AR. Further echocardiographic surveillances after KT are needed in patients with clinical and echocardiographic factors for progression of valve regurgitation.

Funding Acknowledgement

Type of funding sources: None.

Factors determining mitral valve dysfunction in patients who underwent surgical mitral valve replacement with bio-prosthetic valves

Background

There is increasing Interest in bio-prosthetic MVD as recent advances in transcatheter MV interventions, but there is limited data.

Objectives

The aim of this study was to identify the factors determining mitral valve (MV) dysfunction (MVD) in patients who underwent MV replacement with bio-prosthetic valves. Also, we sought to investigate clinical outcomes in patients with bio-prosthetic MVD.

Methods

A total of 233 patients underwent surgical bio-prosthetic MV replacement between June 1996 and May 2015. Finally, 226 patients (mean age 66.9±11.5 years, 74.3% of women) were analyzed, excluding patients who followed-up for less than 5 years and patients whose baseline or follow-up echocardiography could not be analyzed. Clinical, echocardiographic, and laboratory data were collected early after the surgery and during follow-up. MVD was defined as an increase in mean gradient ≥5 mmHg with leaflet motion limitation and/or newly developed MV regurgitation during follow-up. Clinical outcome was defined as a composite of cardiovascular death, redo MV surgery or intervention, and hospitalization for heart failure.

Results

During a median of 102.0 months (interquartile range 72.0 to 132.0 months), 65 patients (28.8%) revealed MVD. 8 (12.3%) patients revealed predominant MV obstruction, and 57 (87.7%) showed predominant MV regurgitation. Factors associated with bio-prosthetic MVD by multivariate regression analysis were young age at operation (hazard ratio 0.97, 95% CI 0.95–0.99, p=0.001), end-stage renal disease (hazard ratio 4.29, 95% CI 1.45–12.71, p=0.007), elevated mean diastolic pressure gradient&gt;5.5 mmHg across the bio-prosthetic MV early after operation (hazard ratio 1.86, 95% CI 0.97–3.74, p=0.063) and anemia after operation (hazard ratio 0.84, 95% CI 0.74–0.95, p=0.007). However, the presence of hypertension, dyslipidemia, or porcine bio-prosthesis was not related to the bio-prosthetic MVD. Kaplan-Meier curves revealed significant differences in event-free survivals for the occurrence of bio-prosthetic MVD according to each factor (Figure 1). Patients with bio-prosthetic MVD showed significantly poor clinical outcomes compared with those without bio-prosthetic MVD (event-free survival 43.1% vs. 91.9%, log-rank p&lt;0.001) during the follow-up.

Conclusions

Young age at operation, end-stage renal disease, elevated mean pressure gradient early after the operation, and anemia after operation were associated with bio-prosthetic MVD in patients who underwent bio-prosthetic MV replacement.

Funding Acknowledgement

Type of funding sources: None.

Controlling the Structure of Carbon Deposit by Nitrogen Doping Catalytic Chemical Vapor Deposition Synthesis

Nitrogen doped multi-walled carbon nanotubes and other carbon nanoparticles were synthesized by catalytic chemical vapor deposition of tripropylamine and acetylene on CaCO₃-supported cobalt catalyst (5 wt%), prepared by impregnation, and various precursors. Each synthesis was performed by using either the pure nitrogenous organic compound or its mixture with acetone. Transmission electron microscopy studies revealed a significant difference both in the yield and the diversity of the carbon deposits. Every synthesis resulted in bamboo-like nanotubes, and nearly all of them also in onion-like structures. Electron energy loss spectroscopy studies of the samples indicated the presence of nitrogen and calcium (caused by the catalyst support). High-resolution transmission electron microscopy and X-ray diffraction measurements were also performed to characterize the samples.

Search for Sub-eV Sterile Neutrinos at RENO

We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino (ν[over ¯]_{e}) disappearance taking place between six 2.8 GW_{th} reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor ν[over ¯]_{e} oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on sin^{2}2θ_{14} in the 10^{-4}≲|Δm_{41}^{2}|≲0.5  eV^{2} region, free from reactor ν[over ¯]_{e} flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at |Δm_{41}^{2}|≲0.002  eV^{2} using the ν[over ¯]_{e} disappearance channel.

P1248Characteristics and clinical significance of right ventricular involvement in patients with hypertrophic cardiomyopathy

Background

A few studies have demonstrated bi-ventricular hypertrophy in hypertrophic cardiomyopathy (HCM). However, clinical significance of HCM with right ventricular (RV) involvement has not been fully established. Therefore, we aimed to investigate the structural characteristics and clinical significance of RV hypertrophy in patients with HCM.

Methods

In a single center, large HCM registry, 256 patients with HCM who underwent both cardiac magnetic resonance (CMR) and transthoracic echocardiography within 6 months were retrospectively analyzed. RV involvement was defined as increased RV wall thickness >7 mm on CMR in any segments of RV free wall and apex. Patients who had evidence of significant RV pressure overload (RV systolic pressure >50mmHg) or had undergone septal myectomy were excluded. Cardiovascular outcomes were defined as the composite of cardiovascular death and hospitalization for cardiovascular disease.

Results

Among 256 patients, 41 (16%) showed RV involvement. During follow-up period (median 1099 days), 32 cardiovascular outcomes (3 cardiovascular death and 29 cardiovascular hospitalization) were occurred. Patients with RV involvement showed a significantly higher left ventricular (LV) thickness (23.8±5.8 vs. 21.2±5.0 mm, p=0.004), more advanced diastolic dysfunction, and larger left atrial volume index (LAVI, 48.5±20.3 vs. 40.2±14.9 mm/m2, p=0.016) compared to those without RV involvement. In multivariate cox regression analysis, presence of RV involvement (HR: 4.21, 95% CI: 1.99–8.90, p<0.001) and LV ejection fraction <50% (HR: 4.29, 95% CI: 1.37–13.43, p=0.012) were independently associated with cardiovascular outcomes. The Kapan-Meier curve showed that there was a significant decrease in probability of cardiovascular outcomes-free survival in patients with RV involvement (p=0.007) after using 1:1 propensity score matching (n=82) to adjust for age, sex, LV ejection fraction, LV maximal wall thickness, LAVI, and RV systolic pressure than patients without RV involvement (Figure 1).

Figure 1

Conclusion

RV involvement in patients with HCM were not rare (16%). Patients with RV involvement showed more advanced LV structure and dysfunction, suggesting an indicator of severe HCM. RV involvement in HCM has clinical significance related to cardiovascular outcomes.

Fuel-Composition Dependent Reactor Antineutrino Yield at RENO

We report a fuel-dependent reactor electron antineutrino (ν[over ¯]_{e}) yield using six 2.8 GW_{th} reactors in the Hanbit nuclear power plant complex, Yonggwang, Korea. The analysis uses 850 666 ν[over ¯]_{e} candidate events with a background fraction of 2.0% acquired through inverse beta decay (IBD) interactions in the near detector for 1807.9 live days from August 2011 to February 2018. Based on multiple fuel cycles, we observe a fuel ^{235}U dependent variation of measured IBD yields with a slope of (1.51±0.23)×10^{-43}  cm^{2}/fission and measure a total average IBD yield of (5.84±0.13)×10^{-43}  cm^{2}/fission. The hypothesis of no fuel-dependent IBD yield is ruled out at 6.6σ. The observed IBD yield variation over ^{235}U isotope fraction does not show significant deviation from the Huber-Mueller (HM) prediction at 1.3 σ. The measured fuel-dependent variation determines IBD yields of (6.15±0.19)×10^{-43} and (4.18±0.26)×10^{-43}  cm^{2}/fission for two dominant fuel isotopes ^{235}U and ^{239}Pu, respectively. The measured IBD yield per ^{235}U fission shows the largest deficit relative to the HM prediction. Reevaluation of the ^{235}U IBD yield per fission may mostly solve the reactor antineutrino anomaly (RAA) while ^{239}Pu is not completely ruled out as a possible contributor to the anomaly. We also report a 2.9 σ correlation between the fractional change of the 5 MeV excess and the reactor fuel isotope fraction of ^{235}U.

Measurement of Reactor Antineutrino Oscillation Amplitude and Frequency at RENO

The RENO experiment reports more precisely measured values of θ_{13} and |Δm_{ee}^{2}| using ∼2200 live days of data. The amplitude and frequency of reactor electron antineutrino (ν[over ¯]_{e}) oscillation are measured by comparing the prompt signal spectra obtained from two identical near and far detectors. In the period between August 2011 and February 2018, the far (near) detector observed 103 212 (850 666) ν[over ¯]_{e} candidate events with a background fraction of 4.8% (2.0%). A clear energy and baseline dependent disappearance of reactor ν[over ¯]_{e} is observed in the deficit of the measured number of ν[over ¯]_{e}. Based on the measured far-to-near ratio of prompt spectra, we obtain sin^{2}2θ_{13}=0.0896±0.0048(stat)±0.0047(syst) and |Δm_{ee}^{2}|=[2.68±0.12(stat)±0.07(syst)]×10^{-3}  eV^{2}.

Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) Associated with Mediastinal Schwannoma

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common cause of euvolemic hypo-osmotic hyponatremia. There are several etiologies of SIADH including neuroendocrine tumor, pulmonary disease, infection, trauma, and medications. Here, we report a case of SIADH associated with a schwannoma involving the mediastinum in a 75-year-old woman who presented with nausea, vomiting, and general weakness. Laboratory testing showed hypo-osmolar hyponatremia, with a serum sodium level of 102mmol/L, serum osmolality of 221mOsm/kg, urine osmolality of 382mOsm/kg, urine sodium of 55 mmol/L, and plasma antidiuretic hormone (ADH) of 4.40 pg/mL. Chest computed tomography identified a 1.5-cm-sized solid enhancing nodule in the right lower paratracheal area. A biopsy specimen was obtained by video-assisted thoracoscopic surgery, which was diagnosed on pathology as a schwannoma. The hyponatremia was completely resolved after schwannoma resection and plasma ADH level decreased from 4.40 pg/mL to 0.86 pg/mL. This case highlights the importance of suspecting and identifying the underlying cause of SIADH when faced with refractory or recurrent hyponatremia, and that on possibility is mediastinal schwannoma

Comparative Analysis of Frozen and Acellularized Vascular Xenografts

Background

We implanted frozen and acellularized porcine xenograft vessels as small-diameter arterial grafts in goats and comparatively analyzed the explanted grafts by gross observation and by light microscopy at predetermined periods.

Materials and Methods

Porcine carotid arteries were harvested and immediately stored within a tissue preservation solution at −70°C in a freezer designated for frozen xenograft vessels. The acellularized xenograft vessels were prepared with NaCl-SDS solution and stored frozen until use. One pair of porcine xenograft vessels were used to compare the frozen and acellularized grafts in the bilateral carotid arteries in one goat. The grafts were implanted for one, 3, and 6 months in three animals. Periodic ultrasonographic examinations were performed during the observation period. Explanted grafts were analyzed by gross observation, and by light microscopy.

Results

All animals survived the experimental procedure without specific problems. Ultrasonographic examinations showed excellent patency in all grafts during the observation period. Gross observations revealed nonthrombotic patent smooth lumens. Microscopic examinations of the explanted grafts showed satisfactory cellular reconstruction to the 6-month stage. Although more inflammatory responses were observed in the early phase of implantation of frozen xenografts than of acellularized xenografts, there was no evidence of significant rejection of the frozen xenografts.

Conclusion

These findings suggest that porcine vessel xenografts, regardless of them being acellularized or simply frozen xenografts, can be acceptably implanted in goats as a form of small-diameter vascular graft.

Atypia of undetermined significance on thyroid fine needle aspiration - risk factors for malignancy

OBJECTIVES

This study is designed to determine the clinical predictors of malignancy in the atypia of undetermined significance (AUS) category resulted from thyroid fine needle aspiration (FNA).

DESIGN

Retrospective cohort study.

SETTING

Dong-A University Medical Center, Busan, Korea.

PARTICIPANTS

Sixty-two patients who underwent thyroid surgery from January 2010 to December 2013, following a diagnosis of AUS from preoperative thyroid FNA.

MAIN OUTCOME MEASURES

We investigated the age, gender, maximum size and site of the nodules, ultrasonographic findings, cytological features, BRAF gene mutation, surgical method, number of AUS on repeated FNA and final pathologic results.

RESULTS

Forty-one of sixty-two patients underwent total thyroidectomy and the rest had lobectomy. The final pathologic results were 41 malignancies and 21 benign diseases. Nodules less than 1.5 cm, ultrasonographic findings suggestive of malignancy were risk factors for malignancy on univariated analysis (P < 0.001). Multivariated analysis showed that nodules less than 1.5 cm, ultrasonographic findings suggestive of malignancy and more than 2 results of atypia from repeated FNAs were significant risk factors for malignancy (P < 0.001). A BRAF gene mutation analysis was performed in 38 patients, and 13 patients had the mutation. All patients with the BRAF gene mutation had been diagnosed with papillary thyroid cancer (P > 0.05).

CONCLUSIONS

We recommend close observation or diagnostic surgery in patients with nodules <1.5 cm and with two or more malignant ultrasound feature and a BRAF mutation, or with two or more AUS findings on repeated FNAs.

Effect of post-voiding urine volume on progression of renal function decline in patients with type 2 diabetes

Diabetic bladder dysfunction (DBD) is a common complication of type 2 diabetes mellitus (T2DM). The association between DBD and progression of diabetic nephropathy has not been clarified. In this study, we investigated the relationship between post-voiding residual urine (PVR) with decline in renal function in patients with type 2 diabetes. This retrospective study included 164 patients at a single center. We collected medical histories and laboratory findings of patients undergoing uroflowmetry from January 1, 2008 to October 30, 2013. Renal function was assessed by calculating the estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) study equation. We evaluated whether greater PVR was a risk factor for faster decline of GFR during a 1-year follow-up. The subjects' mean age was 65±12 years, duration of diabetes 12.8±8.8 years, baseline serum creatinine level 106.1±53.0 μmol/L, and eGFR was 64.6±25.2 mL/min/1.73 m(2). Mean PVR was 69.8±96.3 mL and in 17.7% of subjects, PVR>100 mL. In linear regression analysis, PVR was independently associated with GFR decrease (standardized β coefficient=0.2, P=0.009). Multiple logistic analysis showed that subjects with PVR>100 mL had a 2.8-fold higher risk of an eGFR change during 1 year higher than the median value of all subjects (95% confidence interval, 1.1-6.8; P=0.03). Increased PVR was independently associated with a more rapid decline in renal function in patients with type 2 diabetes.

Further morphological observations on hearts with twisted atrioventricular connections (criss-cross hearts)

A superior and anterior location of the tricuspid valve in the setting of malalignment between the atrial and ventricular septal structures was the characteristic unifying morphologic feature of seven autopsied hearts with twisted atrioventricular connections. The peculiar angiocardiographic appearances of this lesion could be readily explained by the findings of unusual recesses in the right atrium, in the right ventricle, and in the left ventricle. The recess in the morphologically left ventricle was seen in each case at the right posterior part (or, in the hearts with left-handed ventricles, at the left part) of the chamber. Displacement of the right-sided atrioventricular valve far from the inferior caval vein (vena cava) had produced the recess in the morphologically right atrium; this feature was most prominent in the heart in which the atrioventricular connections were discordant. The recess within the right ventricular outflow tract was seen in four hearts, in all of which the inlet and apical trabecular components of the right ventricle were hypoplastic.

The association between an abnormal post-voiding urine volume and a lower estimated glomerular filtration rate in patients with type 2 diabetes with no voiding symptoms

BACKGROUND/AIMS

Diabetic cystopathy is a frequent complication of diabetes mellitus. This study assessed the association between the post-voiding residual (PVR) urine volume and diabetic nephropathy in type 2 diabetics with no voiding symptoms.

METHODS

This study investigated 42 patients with type 2 diabetes who were followed regularly at our outpatient clinic between July 1, 2008 and June 30, 2009. No patient had voiding problems or International Prostate Symptom Scores (IPSSs) ≥ 12. An urologist performed the urological evaluations and the PVR was measured using a bladder scan. A PVR > 50 mL on two consecutive voids was considered abnormal, which was the primary study outcome.

RESULTS

The mean patient age was 60 ± 10 years; the IPSS score was 3.7 ± 3.3; and the diabetes duration was 11.9 ± 7.8 years. Seven of the 42 patients (16.7%) had a PVR > 50 mL. The presence of overt proteinuria or microalbuminuria was associated with an increased risk of a PVR > 50 mL (p < 0.01). Patients with a PVR > 50 mL had a significantly lower estimated glomerular filtration rate (eGFR) compared with those with a PVR ≤ 50 mL (59.2 ± 27.1 mL/min/1.73 m(2) vs. 28.7 ± 23.3 mL/min/1.73 m(2); p < 0.001). Multivariate logistic analysis revealed that a lower eGFR (odds ratio, 0.94; 95% confidence interval, 0.88 to 0.99; p = 0.04) was a significant risk factor for a PVR > 50 mL.

CONCLUSIONS

Patients with diabetic nephropathy had a significantly higher PVR and a lower eGFR was associated with an abnormal PVR.

Quantitation of nanoparticle accumulation in flow using optimized microfluidic chambers

BACKGROUND

The vascular cell adhesion molecule-1 (VCAM-1) targeting peptide sequence, VHPKQHR, is a promising moiety for targeting atherosclerosis through incorporation into nanoparticles such as dendrimers and liposomes.

PURPOSE

We aim to develop VCAM-1-targeted nanoparticles that effectively accumulate on the endothelium under shear conditions and to develop robust microfluidic chambers able to house sufficient cells for flow cytometric measurements.

METHODS

Carboxyfluorescein-labeled monomeric VHP-peptide, tetrameric VHP-dendrimers (bisbidentate or radial architecture, with or without N-terminal acetylation) and VHP-peptide liposomes were prepared. Human umbilical vein endothelial cells were treated with nanoparticles under 0 or 2.9 dyne/cm(2) shear, and particle binding was quantified. Flow chambers cured at various temperatures, with or without glass backings were fabricated, characterized for deformation and applied in experiments.

RESULTS

Although liposomes accumulated with highest efficiency, dendrimers also demonstrated specific binding. N-terminal acetylation significantly reduced dendrimer binding, and despite shorter movement range, bisbidentate dendrimers outperformed radial dendrimers, suggesting multiple epitope presence within its estimated arm-span of 57 Å. Under shear, while liposome binding increased 300%, dendrimer binding to cells decreased 65%. Through higher temperature curing and glass backing insertion, polydimethylsiloxane flow chambers maintaining rectangular cross-section with aspect-ratio as low as 1:111 were achieved.

CONCLUSION

Optimized dendrimers and liposomal nanocarriers specifically accumulated onto cells within microfluidic chambers.

Adhesion mechanisms of the contact interface of TiO2 nanoparticles in films and aggregates

Fundamental knowledge about the mechanisms of adhesion between oxide particles with diameters of few nanometers is impeded by the difficulties associated with direct measurements of contact forces at such a small size scale. Here we develop a strategy based on AFM force spectroscopy combined with all-atom molecular dynamics simulations to quantify and explain the nature of the contact forces between 10 nm small TiO(2) nanoparticles. The method is based on the statistical analysis of the force peaks measured in repeated approaching/retracting loops of an AFM cantilever into a film of nanoparticle agglomerates and relies on the in-situ imaging of the film stretching behavior in an AFM/TEM setup. Sliding and rolling events first lead to local rearrangements in the film structure when subjected to tensile load, prior to its final rupture caused by the reversible detaching of individual nanoparticles. The associated contact force of about 2.5 nN is in quantitative agreement with the results of molecular dynamics simulations of the particle-particle detachment. We reveal that the contact forces are dominated by the structure of water layers adsorbed on the particles' surfaces at ambient conditions. This leads to nonmonotonous force-displacement curves that can be explained only in part by classical capillary effects and highlights the importance of considering explicitly the molecular nature of the adsorbates.

Production of human papillomavirus type 33 L1 major capsid protein and virus-like particles from Bacillus subtilis to develop a prophylactic vaccine against cervical cancer

We developed a bacterial expression system to produce human papillomavirus (HPV) type 33 L1 major capsid protein and virus-like particles from a recombinant Bacillus subtilis strain. For the first time, we have isolated self-assembled virus-like particles (VLPs) of HPV type 33 from B. subtilis, a strain generally recognized as safe (GRAS). The gene encoding the major capsid protein L1 of HPV type 33 was amplified from viral DNA isolated from a Korean patient and expressed in B. subtilis; a xylose-induction system was used to control gene activity. HPV33 L1 protein was partially purified by 40% (w/v) sucrose cushion centrifugation and strong cation exchange column chromatography. Eluted samples exhibited immunosignaling in fractions of 0.5-1.0 M NaCl. The HPV33 L1 protein was shown to be approximately 56 kDa in size by SDS-PAGE and Western blotting; recovery and purity were quantified by indirect immuno-ELISA assay. The final yield and purity were approximately 20.4% and 10.3%, respectively. Transmission electron microscopic analysis of fractions immunoactive by ELISA revealed that the L1 protein formed self-assembled VLPs with a diameter of approximately 20-40 nm. Humoral and cellular immune responses provoked by the B. subtilis/HPV33 L1 strain were approximately 100- and 3-fold higher than those of the empty B. subtilis strain as a negative control, respectively. Development of a VLP production and delivery system using B. subtilis will be helpful, in that the vaccine may be convenient production as an antigen delivery system. VLPs thus produced will be safer for human use than those purified from Gram-negative strains such as Escherichia coli. Also, use of B. subtilis as a host may aid in the development of either live or whole cell vaccines administered by antigen delivery system.

Radiosurgery for metastatic spinal tumors: follow-up MR findings

BACKGROUND AND PURPOSE

MR imaging is the primary tool for evaluation and monitoring of spinal tumors. We retrospectively analyzed the MR imaging findings before and after SRS for metastatic spinal tumors.

MATERIALS AND METHODS

We reviewed MR imaging findings on 79 metastatic spinal tumor lesions in 44 patients (29 male and 15 female)who had undergone radiosurgery between November 2003 and April 2008. Posttreatment MR imaging was evaluated retrospectively for 3 aspects: 1) changes in tumor volume; 2) changes in T2 signal intensity;and 3) changes in contrast enhancement patterns.

RESULTS

With regard to tumor volume on MR images, 32 lesions(40.5%) decreased in volume (group 1), 39 (49.4%) showed no change (group 2), and 8 (10.1%) increased in volume (group 3). T2 signal intensities were unchanged in 4 lesions (type 1), homogeneously increased in 3 (type 2), and changed to a homogeneously dark signal in 4 (type 4). The T2 signal intensity was increased and inter mixed with dark signal intensity (type 3) in 68 lesions. A decrease in contrast enhancement with or without non-enhancing foci was seen in 73 lesions. A persistent homogeneous enhancement pattern was seen in all 4 of the type 1 lesions, in 1 of the 3 type 2 lesions, and in 1 of the 68 type 3 lesions.

CONCLUSIONS

Main MR imaging features of locally controlled metastatic spinal tumors included no increase in tumor volume, increased T2 signal intensity with intermixed T2 dark signal intensity,and decreased contrast enhancement. Follow-up MR imaging also provided several patterns of tumor recurrence [corrected].

Versatility of right gastroepiploic and gastroduodenal arteries for arterial reconstruction in adult living donor liver transplantation

BACKGROUND

In cases where there is severe intimal dissection in the recipient hepatic artery (HA), or if the HA has been used already and additional operations are needed due to graft rejection or arterial occlusion, an alternative is necessary. In the present study, we have reported the feasibility of using the right gastroepiploic artery (RGEA) and gastroduodenal artery (GDA) in various situations where the HA is not a feasible option.

METHODS

Among 463 patients who underwent primary adult-to-adult living donor liver transplantation from January 2002 to July 2010, eight subjects required alternative vessels. Four recipients displayed severe intimal injury associated with previous transarterial chemoembolization (TACE); two, required a salvage operation due to hepatic artery thrombosis (HAT); and two, retransplantations due to chronic rejection. The RGEA was used in five and the GDA in three patients.

RESULTS

Postoperative Doppler ultrasonography and three-dimensional computed tomography showed patent arterial flow in all patients. However, HAT recurred in one patient who underwent a salvage operation with the RGEA; she died 2 months later. Two other patients died due to wound infection and respiratory failure within 3 months despite intact hepatic arterial flow. Four patients had no further complications during follow-up (mean = 33 months).

CONCLUSION

Although there was a discrepancy in the diameter of the HA and the RGEA (or GDA), there was no problem with mobilization and microanastomosis. We therefore believe that these vessels can be good alternatives when the hepatic artery is unavailable.

Epiblepharon related to high body mass index in Korean children

PURPOSE

To evaluate the clinical manifestations of epiblepharon in Korean children and the relationship between this condition and body mass index.

METHODS

In a retrospective case-control study, 223 children 6 to 15 years of age treated surgically for epiblepharon were studied and compared with an age-matched control group of 264 children. Data on age, sex, weight, height, and recurrence were recorded.

RESULTS

Mean age of the patients was 8.63 ± 4.43 years. Lower eyelids were commonly involved bilaterally. Chief complaints included ocular discomfort, eye rubbing, visual disturbances, photophobia, and epiphora. Minimal resection of orbicularis oculi with full-thickness eyelid rotatory suture for epiblepharon was performed on 223 patients. The body mass index in girls 12 to 15 years old with epiblepharon was significantly higher than that in children without epiblepharon (P < .05). There was a statistically significant correlation between the incidence of epiblepharon and obesity with aging in girls (P < .05). Reoperation was performed on 12 patients (4.4%) because of recurrence of corneal irritation with inverted eyelashes. Clinical factors such as sex, age, and body mass index did not affect the rate of recurrence.

CONCLUSION

Epiblepharon is one of the most common eyelid abnormalities among Asian children. Obese Korean girls aged 12 to 15 years demonstrated symptomatic epiblepharon at a statistically significant level.

Tunable magnetic interaction at the atomic scale in oxide heterostructures

We report on a systematic study of a number of structurally identical but chemically distinct transition metal oxides in order to determine how the material-specific properties such as the composition and the strain affect the properties at the interface of heterostructures. Our study considers a series of structures containing two layers of ferromagnetic SrRuO₃, with antiferromagnetic insulating manganites sandwiched in between. The results demonstrate how to control the strength and relative orientation of interfacial ferromagnetism in correlated electron materials by means of valence state variation and substrate-induced strain, respectively.

The structure of graphite oxide: investigation of its surface chemical groups

The structure of graphite oxide (GO) has been systematically studied using various tools such as SEM, TEM, XRD, Fourier transform infrared spectroscopy (FT-IR), X-ray photoemission spectroscopy (XPS), (13)C solid-state NMR, and O K-edge X-ray absorption near edge structure (XANES). The TEM data reveal that GO consists of amorphous and crystalline phases. The XPS data show that some carbon atoms have sp(3) orbitals and others have sp(2) orbitals. The ratio of sp(2) to sp(3) bonded carbon atoms decreases as sample preparation times increase. The (13)C solid-state NMR spectra of GO indicate the existence of -OH and -O- groups for which peaks appear at 60 and 70 ppm, respectively. FT-IR results corroborate these findings. The existence of ketone groups is also implied by FT-IR, which is verified by O K-edge XANES and (13)C solid-state NMR. We propose a new model for GO based on the results; -O-, -OH, and -C=O groups are on the surface.

An optical and microPET assessment of thermally-sensitive liposome biodistribution in the Met-1 tumor model: Importance of formulation

The design of delivery vehicles that are stable in circulation but can be activated by exogenous energy sources is challenging. Our goals are to validate new imaging methods for the assessment of particle stability, to engineer stable and activatable particles and to assess accumulation of a hydrophilic model drug in an orthotopic tumor. Here, liposomes were injected into the tail vein of FVB mice containing bilateral Met-1 tumors and imaged in vivo using microPET and optical imaging techniques. Cryo-electron microscopy was applied to assess particle shape prior to injection, ex vivo fluorescence images of dissected tissues were acquired, excised tissue was further processed with a cell-digest preparation and assayed for fluorescence. We find that for a stable particle, in vivo tumor images of a hydrophilic model drug were highly correlated with PET images of the particle shell and ex vivo fluorescence images of processed tissue, R(2)=0.95 and R(2)=0.99 respectively. We demonstrate that the accumulation of a hydrophilic model drug is increased by up to 177 fold by liposomal encapsulation, as compared to accumulation of the drug at 24 hours.

Continuous venovenous hemodiafiltration versus hemodialysis as renal replacement therapy in patients with acute renal failure in the intensive care unit

OBJECTIVE

Hemodialysis (HD) and continuous venovenous hemodiafiltration (CVVHDF) have been adopted as forms of renal replacement therapy (RRT) in patients with acute renal failure (ARF). Although CVVHDF has many advantages, previous studies reported no definite improvement in survival rate compared to HD.

MATERIAL AND METHODS

In this retrospective study, 148 intensive care unit patients underwent HD (70 males, 25 females; mean age 45 +/- 17 years) or CVVHDF (42 males, 11 females; mean age 52 +/- 18 years). The severity of illness was estimated at the initiation of RRT and on the third day of RRT and presented using the APACHE III scoring system. The number of organ failures was checked at the initiation of RRT.

RESULTS

The survival rate was 46% in the HD group and 21% in the CVVHDF group (p = 0.002). CVVHDF was applied to the more severely ill patients, who had longer periods using a ventilator (p = 0.002) and/or vasopressor (p < 0.001), higher numbers of organ failures (p < 0.001) and higher initial APACHE III scores (p < 0.001). Among patients with APACHE III scores > 103, the survival rate was 13% in the CVVHDF group and 0% in the HD group. In patients with kidney failure and failure of two other organs, the survival rate was 9% in the HD group and 36% in the CVVHDF group (p = 0.035).

CONCLUSION

The mortality rate in the CVVHDF group was higher than that in the HD group, which may have been because CVVHDF was applied to the more severely ill patients. In contrast, CVVHDF may give a chance of survival to patients with APACHE III scores > 103 and may be more useful than HD in patients with failure of three or more organs.

Decomposition of 1,4-dioxane by photo-Fenton oxidation coupled with activated sludge in a polyester manufacturing process

The cyclic ether 1,4-dioxane is a synthetic industrial chemical that is used as a solvent in producing paints and lacquers. The EPA and the International Agency for Research on Cancer(IARC) classified 1,4-dioxane as a GROUP B2(probable human) carcinogen. 1,4-dioxane is also produced as a by-product during the manufacture of polyester. In this research, a polyester manufacturing company (i.e. K Co.) in Gumi, Korea was investigated regarding the release of high concentrations of 1,4-dioxane (about 600 mg/L) and whether treatment prior to release should occur to meet with the level of the regulation standard (e.g., 5 mg/L in 2010). A 10 ton/day pilot-scale treatment system using photo-Fenton oxidation was able to remove approximately 90% of 1,4-dioxane under the conditions that concentrations of 2800 ppm H(2)O(2) and 1,400 ppm FeSO(4) were maintained along with 10 UV-C lamps (240 microW/cm(2)) installed and operated continuously during aeration. However, the effluent concentration of 1,4-dioxane was still high at about 60 mg/L where TOC concentration in the effluent had been moreover increased due to decomposed products such as aldehydes and organic acids. Thus, further investigation is needed to see whether the bench scale (reactor volume, 8.9 L) of activated sludge could facilitate the decomposition of 1,4-dioxane and their by-products (i.e., TOC). As a result, 1,4-dioxane in the effluent has been decreased as low as 0.5 mg/L. The optimal conditions for the activated sludge process that were obtained are as follows: DO, 3-3.5 mg/L; HRT, 24 h; SRT 15 d; MLSS, 3,000 mg/L. Consequently, photo-Fenton oxidation coupled with activated sludge can make it possible to efficiently decompose 1,4-dioxane to keep up with that of the regulation standard.

Magnesium metabolism

Magnesium is the second most common intracellular divalent cation. Magnesium balance in the body is controlled by a dynamic interplay among intestinal absorption, exchange with bone, and renal excretion. Intestinal magnesium absorption proceeds in both a passive paracellular and an active transcellular manner. Regulation of serum magnesium concentrations is achieved mainly by control of renal magnesium reabsorption. Only 20% of filtered magnesium is reabsorbed in the proximal tubule, whereas 60% is reclaimed in the cortical thick ascending limb (TAL) and another 5-10% in the distal convoluted tubule (DCT). The passive paracellular transport of magnesium in the TAL is closely related with the mutations in claudin-16/paracellin-1 and is responsible for familial hypomagnesemia with hypercalciuria and nephrocalcinosis. The active transcellular transport of magnesium in the DCT was similarly enhanced by the realization that defects in transient receptor potential melastatin 6 (TRPM6) cause hypomagnesemia with secondary hypocalcemia. This channel regulates the apical entry of magnesium into epithelia and alters whole-body magnesium homeostasis by controlling urinary excretion. TRPM6 is regulated at the transcriptional level by acid-base status, 17β-estradiol, and both FK506 and cyclosporine. The molecular identity of the protein responsible for the basolateral exit of magnesium from the epithelial cell remains unidentified.

Polymorphism in the promoter region of the klotho gene (G-395A) is associated with early dysfunction in vascular access in hemodialysis patients

BACKGROUND/AIMS

Vascular access dysfunction is an important cause of morbidity and mortality in hemodialysis (HD) patients. Recent studies have shown that a klotho gene mutation is related to endothelial dysfunction, thrombosis, and arteriosclerosis, which are regarded as causes of vascular access dysfunction. We investigated the relationship between the klotho G-395A polymorphism and early dysfunction in vascular access in HD patients.

METHODS

Patients who underwent vascular access operations between 1999 and 2002 were enrolled (n=126). Genotyping was performed by allelic discrimination using a 5'-nuclease polymerase chain reaction assay. Clinical data that could be relevant to access dysfunction were obtained from medical records. Early dysfunction of vascular access was defined as the need for any angioplastic or surgical intervention to correct or replace a poorly or nonfunctioning vascular access within 1 year and at least 8 weeks after initial access placement.

RESULTS

Of the 126 patients, the genotype frequency of G-395A was 72.2% for GG (n=91), 24.6% for GA (n=31), and 3.2% for AA (n=4), and the frequency of minor allele was 0.155. Clinical data were similar between the two groups, divided according to the status of the A allele. Early dysfunction occurred in 34 (27.0%) of patients, but it occurred at a significantly higher rate in A allele carriers (45.7%, 16/35) than in noncarriers (19.8%, 18/91; p=0.003).

CONCLUSIONS

Our results suggest that the klotho G-395A polymorphism could be a risk factor for early dysfunction of vascular access in HD patients.

Antiferromagnetic LaFeO(3) thin films and their effect on exchange bias

Antiferromagnetic (AFM) orthoferrites are interesting model systems for exploring the correlation between their crystalline and AFM domains and the resulting exchange bias when coupled to a ferromagnetic layer. In particular, LaFeO(3) (LFO) has a Néel temperature, T(N) = 740 K, which is the highest in the orthoferrite family. The recent developments of synchrotron radiation-based photoelectron emission microscopy (PEEM) have provided the possibility of studying AFM domain structures as well as the magnetic coupling between the AFM and the adjacent ferromagnetic (FM) layer, domain by domain. Thin films of LFO have proved excellent candidates for such studies because their AFM domains are well defined and large enough to be readily imaged by PEEM. This paper reviews the growth, structural and magnetic properties of LFO thin films as well as exchange coupling to a FM layer. The strong correlation between structural and AFM domains in this material allows us to investigate the exchange coupling as a function of the domain configuration, which can be changed by using different substrate material and substrate orientation. A significant increase of the exchange bias field by a factor of about 10 was obtained when LFO was diluted with Ni atoms in the volume part. In this sample, the structural domain boundary became corrugated due to substitutional defects. Our results indicate that the details of the precise domain boundary configuration strongly affect the exchange coupling.

High glucose-induced NF-kappaB activation occurs via tyrosine phosphorylation of IkappaBalpha in human glomerular endothelial cells: involvement of Syk tyrosine kinase

Activation of nuclear factor-kappaB (NF-kappaB) occurs by dissociation from IkappaB after serine or tyrosine phosphorylation of IkappaBalpha, but the way of NF-kappaB activation by high glucose has not been defined. High glucose is known to activate NF-kappaB via protein kinase C and reactive oxygen species (ROS). In this study, we investigated how high glucose activates NF-kappaB for CC chemokine ligand 2 production in cultured human glomerular endothelial cells. High glucose increased nuclear translocation of p65 and also increased NF-kappaB DNA binding activity. High glucose-induced NF-kappaB activation occurred without degradation of IkappaBalpha. In agreement with this, there was no increase in serine phosphorylation of IkappaBalpha, while tyrosine phosphorylation of IkappaBalpha was increased by high glucose. High glucose increased the generation of ROS, whereas both alpha-lipoic acid and N-acetylcysteine scavenged the ROS and decreased high glucose-induced tyrosine phosphorylation of IkappaBalpha, nuclear translocation of p65, and NF-kappaB DNA binding activity. Protein kinase C pseudosubstrate inhibited high glucose-induced ROS production, tyrosine phosphorylation of IkappaBalpha, and nuclear translocation of p65. Both BAY 61-3606, a specific inhibitor of Syk protein-tyrosine kinase, and small interfering RNA directed against Syk inhibited high glucose-induced tyrosine phosphorylation of IkappaBalpha as well as p65 nuclear translocation. High glucose increased tyrosine phosphorylation of Syk, while it was inhibited by alpha-lipoic acid and protein kinase C pseudosubstrate. In summary, high glucose-induced NF-kappaB activation occurred not by serine phosphorylation of IkappaBalpha. Our data suggest that ROS-mediated tyrosine phosphorylation of IkappaBalpha is the mechanism for high glucose-induced NF-kappaB activation, and Syk may play a role in tyrosine phosphorylation of IkappaBalpha.

A system for ubiquitous health monitoring in the bedroom via a Bluetooth network and wireless LAN

Advances in information technology have enabled ubiquitous health monitoring at home, which is particularly useful for patients, who have to live alone. We have focused on the automatic and unobtrusive measurement of biomedical signals and activities of patients. We have constructed wireless communication networks in order to transfer data. The networks consist of Bluetooth and Wireless Local Area Network (WLAN). In this paper, we present the concept of a ubiquitous-Bedroom (u-Bedroom) which is a part of a ubiquitous-House (u-House) and we present our systems for ubiquitous health monitoring.

Histopathologic changes of acellularized xenogenic carotid vascular grafts implanted in a pig-to-goat model

INTRODUCTION

The present study was designed to determine the in vivo patency and recellularization pattern of acellularized small-diameter xenogenic arterial grafts. We implanted acellularized porcine carotid arteries in bilateral carotid arteries of goats and microscopically analyzed the recellularization pattern of these grafts with the recipient's cells over time.

MATERIAL AND METHODS

Carotid arteries of pigs weighing 30-40 kg were harvested and decellularized with hypertonic saline followed by sodium dodecyl sulfate. Acellularized porcine carotid vascular xenografts (0.4-0.5 cm in diameter) were prepared into 4 cm-long segments and implanted bilaterally in the carotid arteries of 10 black-haired goats. The in vivo patency of the implanted acellularized xenogenic grafts was evaluated at regular intervals by color Doppler ultrasonography. The goats were sacrificed at predetermined intervals (1 week, 1 month, 3 months, 6 months, 12 months after implantation), two animals at each interval. Upon retrieval, visual inspections and histopathologic examinations of the grafts were performed. To identify smooth muscle cells and functioning endothelial cells, immunohistochemical staining for alpha-smooth muscle actin and von Willebrand factor were also performed.

RESULTS AND CONCLUSIONS

All experimental animals survived the observation period. Nineteen out of 20 implanted grafts showed patency with no thrombi. Microscopic analysis revealed that the grafts were completely covered with the hosts' endothelial cells, beginning from anastomotic sites. The grafts were gradually recellularized with recipients'cells including fibroblasts, myofibroblasts and smooth muscle cells. In conclusion, this study suggested that acellularized xenogenic vascular grafts can be a good alternative for the small-diameter vascular graft.

Hyponatremia: management errors

Rapid correction of hyponatremia is frequently associated with increased morbidity and mortality. Therefore, it is important to estimate the proper volume and type of infusate required to increase the serum sodium concentration predictably. The major common management errors during the treatment of hyponatremia are inadequate investigation, treatment with fluid restriction for diuretic-induced hyponatremia and treatment with fluid restriction plus intravenous isotonic saline simultaneously. We present two cases of management errors. One is about the problem of rapid correction of hyponatremia in a patient with sepsis and acute renal failure during continuous renal replacement therapy in the intensive care unit. The other is the case of hypothyroidism in which hyponatremia was aggravated by intravenous infusion of dextrose water and isotonic saline infusion was erroneously used to increase serum sodium concentration.

Percutaneous insertion of Zilver stent in malignant biliary obstruction

BACKGROUND

We evaluated the clinical efficacy and technical feasibility of the percutaneously inserted self-expandable nitinol stent (Zilver stent) for palliation of malignant biliary obstruction.

METHODS

Seventeen patients with malignant tumors involving the intra- or extrahepatic bile duct who presented with obstructive jaundice underwent percutaneous insertion of a self-expandable nitinol stent. We retrospectively reviewed the hospital records of patients and evaluated the technical feasibility on stent placement, complications, patient survival, and duration of stent patency.

RESULTS

Percutaneous biliary stenting with 27 Zilver stents was performed in 17 patients with malignant biliary obstruction. Technical success was 95%. Malposition of the stent was encountered in one patient. Minor technical problems were encountered in two patients: the introducer tip was broken during stent insertion, so endoscopic removal was done. Mean follow-up period for the 17 patients was 182 days (range 29-485 days): nine patients died of progressive disease at a mean follow-up of 151 days (range 61-371days) after stent insertion and eight patients remained alive at the final follow-up of 216 days (range 29-485 days). The median survival period for all patients was 277 days. The stent occlusion rate was 26% and the mean patency period was 280 days. In five patients, seven stents were obstructed by tumor ingrowth and overgrowth. Stent patency rates were 100%, 100%, 75%, 61%, and 41% at 1, 2, 3, 6, and 12 months, respectively. A late complication, erosive bleeding of the hepatic artery by the stent, developed in one patient.

CONCLUSION

Percutaneous biliary stenting using the nitinol stent is technically feasible and safe and clinically efficacious treatment for malignant biliary obstruction, even with a minor technical problem during stent insertion.

Growth of Single-Crystalline KNbO3 Nanostructures

This communication reports on the growth of highly uniform KNbO3 nanowires exhibiting a narrow diameter distribution around 60 nm and a length-to-width ratio up to 100. The nanowires were prepared by a hydrothermal route, which enables simple, gram-scale production. A systematic study of the synthesized nanowires in terms of the morphological and chemical characteristics was carried out by varying the temperature-pressure conditions and the composition of the starting mixture. The results indicate that highly uniform single-crystalline nanowires form within a narrow window of the ternary phase diagram of KOH-Nb2O5-H2O.