An effective moisture interference correction method for maize powder NIR spectra analysis

The detection of maize starch content is of great significance for maize processing industry and near-infrared spectroscopy (NIRS) is an ideal rapid detection technology. However, the interference of moisture in maize is a bottleneck problem that affects the accuracy of NIRS quantitative analysis. In this study, we proposed methods based on external parameter orthogonalization (EPO) combined with wavelength selection algorithms to bring more accurate analytical results. Two groups of maize starch samples with different moisture content distributions were investigated to compare the predictive performance of NIRS models. The results showed that the model built using EPO combined with the synergy interval partial least squares (EPO-siPLS) algorithm exhibited the superior prediction accuracy, whose RMSEP/RMSEPck is improved by 9.7 % compared with that of siPLS model, 25.3 % compared with that of EPO-PLS, and 45.8 % compared with that of the PLS model. This study provides a more accurate and robust new method for rapid detection of maize starch and offers new insights for its application.

Rapid and accurate determination methods based on data fusion of laser-induced breakdown spectra and near-infrared spectra for main elemental contents in compound fertilizers

Compound fertilizer occupies a dominant position in the structure of fertilizer products in China. The contents of nitrogen, phosphorus and potassium are the key indicators affecting the fertilization efficiency and the price of compound fertilizers. Laser-induced breakdown spectroscopy (LIBS) and near-infrared spectroscopy (NIRS) are two rapid analytical techniques suitable for online monitoring of the above components in compound fertilizer. However, accurate LIBS analysis needs to overcome matrix effects and interference from environmental elements, and NIRS also has the limitation of not being able to directly detect inorganic components in compound fertilizers. The combination of LIBS and NIRS techniques, namely LIBS-NIRS data fusion, has the potential to reduce interferences in the detection of single spectroscopic techniques and further improve the analysis accuracy. This study compared the LIBS-NIRS data fusion methods under different optimization conditions, and found that CARS-OPF (competitive adaptive reweighted sampling combined with outer product fusion) and CARS-EWF (competitive adaptive reweighted sampling combined with equal weight fusion) are two effective intermediate data fusion methods which can achieve better quantitative analysis results than single spectroscopic methods. The root mean square errors of prediction (RMSEP) for nitrogen, phosphorus, and potassium contents in compound fertilizers by using CARS-OPF are 0.901, 0.693, and 1.52, respectively, and the RMSEP for those indicators by using CARS-EWF are 0.934, 0.719, and 1.60, respectively. In these two methods, the LIBS and NIRS characteristic variables of compound fertilizers are firstly screened by CARS algorithm, and then intermediate data fusion was carried out by using equal weight fusion or outer product fusion. Redundant variables in the original data can be well removed in the data fusion process to ensure the accuracy of the analysis. Therefore, the combined methods of LIBS-NIRS based on CARS-OPF and CARS-EWF could be well applied to the rapid and accurate detection of main elemental contents in compound fertilizers.

Biomimetic mineralization by confined diffusion with viscous hyaluronan network: Assembly of hierarchical flower-like supraparticles

Biomolecules-mediated biomimetic mineralization has been extensively investigated and applied to fabricate nano-assemblies with unique hierarchical architectures and salient properties. The confined-source ion diffusion plays a key role in the biomineralization process, but little investigative efforts have focused on it. Here, we developed a simple method to mimic the in vivo condition by a confined diffusion method, and hydroxyapatite nanoflower assemblies (HNAs) with exquisite hierarchical architectures were obtained. The HNAs were assembled from needle-like hybrid nanocrystals of hydroxyapatite and hyaluronan. The results revealed that the strong interactions between ions and hyaluronan led to the nucleation of hydroxyapatite and the following aggregation. The combination of the external diffusion field and the internal multiple interactions induced the self-assembling processes. Additionally, HNAs with colloid stability and excellent biocompatibility were proved to be a promising cargo carrier for intranuclear delivery. This work presents a novel biomimetic mineralization strategy based on confined diffusion system for fabricating delicate hydroxyapatite, which offers a new perspective for the development of biomimetic strategies.

Data fusion strategy based on ultraviolet-visible spectra and near-infrared spectra for simultaneous and accurate determination of key parameters in surface water

Chemical oxygen demand (COD), ammonia nitrogen (AN) and total nitrogen (TN) are the key parameters to reflect the degree of surface water pollution. Ultraviolet - visible (UV-Vis) spectroscopy and near - infrared (NIR) spectroscopy are ideal techniques for rapid monitoring of these indicators. In this study, a strategy based on the fusion of UV-Vis and NIR spectral data (UV-Vis-NIR) for water quality detection was proposed to further improve the quantitative analysis accuracy of spectroscopic methods. Seventy river samples with different levels of pollution were used for spectroscopic analysis. The UV-Vis-NIR fusion spectrum of each water sample was obtained by directly splicing sample's UV-Vis spectrum and NIR diffuse transmission spectrum. The UV-Vis-NIR fusion models were optimized through using different variable selection algorithms. The results show that the UV-Vis-NIR fusion models for surface water COD, AN and TN achieves better prediction results (the root mean square errors of prediction are 6.95, 0.195, and 0.466, respectively) than single-spectroscopic based models. Since better prediction performances were shown under different optimization conditions, the robustness of fusion models were also better than the single-spectroscopic based models. Therefore, the data fusion strategy proposed in this study has a promising application prospect for further accurate and rapid monitoring of surface water quality.

Serum uric acid to creatinine ratio as a risk factor for mortality among patients on continuous ambulatory peritoneal dialysis: a multi-center retrospective study

BACKGROUND

Serum uric acid to serum creatinine ratio (SUA/Scr) has emerged as a new biomarker, which is significantly associated with several metabolic diseases. However, no study has investigated the association between SUA/Scr and mortality among patients on continuous ambulatory peritoneal dialysis (CAPD).

METHODS

In this multicenter retrospective cohort study, we enrolled CAPD patients in eight tertiary hospitals in China from 1 January 2005 to 31 May 2021. Cox proportional hazard models were used to determine the relationship between SUA/Scr and mortality.

RESULTS

A total of 2480 patients were included; the mean age was 48.9 ± 13.9 years and 56.2% were males. During 12648.0 person-years of follow-up, 527 (21.3%) patients died, of which 267 (50.7%) deaths were caused by cardiovascular disease. After multivariable adjustment for covariates, per unit increase in SUA/Scr was associated with a 62.9% (HR, 1.629 (95% confidence interval (CI) 1.420-1.867)) and 73.0% (HR, 1.730 (95% CI 1.467-2.041)) higher risk of all-cause and cardiovascular mortality. Results were similar when categorized individuals by SUA/Scr quartiles. Compared with the lowest quartile of SUA/Scr, the highest and the second highest quartile of SUA/Scr had a 2.361-fold (95% CI 1.810-3.080) and 1.325-fold (95% CI 1.003-1.749) higher risk of all-cause mortality, as well as a 3.701-fold (95% CI 2.496-5.489) and 2.074-fold (95% CI 1.387-3.100) higher risk of cardiovascular mortality. Multivariable-adjusted spline regression models showed nonlinear association of SUA/Scr with mortality in CAPD patients.

CONCLUSIONS

Higher levels of SUA/Scr were associated with higher risk of all-cause and cardiovascular mortality in CAPD patients.

A Low Prognostic Nutritional Index Is a Risk Factor for High Peritoneal Transport Status in Patients Undergoing Peritoneal Dialysis

OBJECTIVES

A high peritoneal transport status is a risk factor for mortality and causes technical failure in patients on peritoneal dialysis (PD). High peritoneal transport status is associated with malnutrition and inflammation in patients with PD. The prognostic nutritional index (PNI) is a marker determined by the serum albumin level and lymphocyte count in the peripheral blood. The aim of this study is to investigate the association between PNI and high peritoneal transport status in patients with PD.

METHODS

We retrospectively investigated patients with PD from January 1, 2013 to May 31, 2020, in 4 PD centers. Patients with PD were divided into 2 groups according to PNI quartiles: the low PNI group (PNI ≤ 36.6) and the high PNI group (PNI > 36.6). The demographics and clinical and laboratory baseline data of the 2 groups were collected and compared. The association between PNI and high peritoneal transport status was analyzed by multivariate logistic regression analysis.

RESULTS

A total of 404 patients with PD were enrolled in our study. A total of 77 (19.06%) patients had high peritoneal transport status. After adjusting for age, sex, body mass index, hypertension, diabetes mellitus, residual urine volume, current smoking status, pre-existing cardiovascular disease, hemoglobin, white blood cell count, triglycerides, and intact parathyroid hormone, low PNI levels were significantly associated with high peritoneal transport status (odds ratio 3.42, 95% confidence interval 1.82-5.18, P = .0056). Subgroup analysis showed that there was no interaction among PNI and age, sex, diabetes, body mass index, pre-existing cardiovascular disease, or current smoking.

CONCLUSION

As a marker for malnutrition and inflammation, a low level of PNI is an independent risk factor for high peritoneal transport status in patients with PD.

Platelet-to-lymphocyte ratio and the first occurrence of peritonitis in peritoneal dialysis patients

BACKGROUND

Platelet-to-lymphocyte ratio (PLR) has been used as a potential biomarker of inflammation-related diseases, but its role in the peritoneal dialysis-related peritonitis (PDRP) is still uncertain. This study was aimed to investigate the association between PLR and the new-onset PDRP in peritoneal dialysis (PD) patients.

METHODS

In this multicenter retrospective study, 1378 PD Chinese PD patients were recruited from four centers, who were divided into the high PLR group (HPG) and the low PLR group (LPG) according to the cutoff value of PLR. The correlation between PLR and the new-onset PDRP was assessed using the Cox regression model analysis.

RESULTS

During follow-up, 121 new-onset PDRP events were recorded. Kaplan-Meier survival curve showed a higher risk of new-onset PDRP in the HPG (log-rank test, P < 0.001). After adjusting for confounding factors, the Cox regression model showed the risk of new-onset PDRP was higher in the HPG than that in the LPG (HR 1.689, 95%CI 1.096-2.602, P = 0.017). Competitive risk model analysis showed that significant differences still existed between the two PLR groups in the presence of other competitive events (P < 0.001).

CONCLUSION

PLR is independently associated with the new-onset PDRP in PD patients.

Genome-Wide Identification and Expression Analysis of m6A Writers, Erasers, and Readers in Litchi (Litchi chinensis Sonn.)

N6-methyladenosine (m6A) RNA modification is the most prevalent type of RNA methylation and plays a pivotal role in the development of plants. However, knowledge of the m6A modification in litchi remains limited. In this study, a complete analysis of m6A writers, erasers, and readers in litchi was performed and 31 litchi m6A regulatory genes were identified in total, including 7 m6A writers, 12 m6A erases, and 12 readers. Phylogeny analysis showed that all three of the kinds of litchi m6A regulatory proteins could be divided into three groups; domains and motifs exhibited similar patterns in the same group. MiRNA target site prediction showed that 77 miRNA target sites were located in 25 (80.6%) litchi m6A regulatory genes. Cis-elements analysis exhibited that litchi m6A regulatory genes were mainly responsive to light and plant hormones, followed by environmental stress and plant development. Expression analysis revealed litchi m6A regulatory genes might play an important role during the peel coloration and fruit abscission of litchi. This study provided valuable and expectable information of litchi m6A regulatory genes and their potential epigenetic regulation mechanism in litchi.

Biocompatible, bacteria-targeting resveratrol nanoparticles fabricated by Mannich molecular condensation for accelerating infected wound healing

Excessive reactive oxygen species (ROS) and long-term inflammation can delay wound healing and cause tissue damage, while bacterial infection aggravates the wound environment further. It is impossible to resolve all these thorny problems simultaneously with a wound dressing that has only one function. The antioxidative and anti-inflammatory properties of resveratrol (Res) have been proven. However, the effect of Res is non-selective, and high levels of Res can inhibit cell growth and promote oxidation. Res is also difficult to dissolve and possesses insufficient antibacterial properties, so its role is limited. In this study, Res was assembled via Mannich reaction into nanoparticles and functionalized by phenylboric acid, giving rise to targeting bacteria and solving the water-insoluble dilemma of Res. In comparison with Trolox, the assembled Res NPs performed better at scavenging ABTS and DPPH free radicals. Furthermore, Res NPs that targeted bacteria also showed high biocompatibility at concentrations five times higher than pure Res. The activities of Res NPs were comparable to free Res in downregulating the expression of inflammatory cytokines, and reducing intracellular excessive ROS. The gel embedded with Res NPs accelerated the formation of granulation tissue, collagen deposition, and re-epithelialization, facilitating wound healing. The present study suggests that functionalized polyphenol-based materials are preferably suited to the development of tissue engineering biomaterials.

Water-Recyclable Chitosan-Based Ion-Imprinted Thermoresponsive Hydrogel for Rare Earth Metal Ions Accumulation

The demand for rare earth metal increases rapidly in the modern high-tech industry and therefore the accumulation of rare earth metal ions from an aqueous environment becomes a significant concern worldwide. In this paper, a water-recyclable chitosan-based La³⁺-imprinted thermoresponsive hydrogel (CLIT) was prepared to accumulate La³⁺ from solution. The CLIT was characterized by DSC, FITR, Raman spectroscopy, XPS, and SEM, which revealed obvious reversible thermosensitivity and imprinted sites of La³⁺ ions. An adsorption capacity of 112.21 mg/g to La³⁺ ions was achieved on CLIT under its optimum adsorption conditions (pH 5, 50 °C, 60 min). The adsorption could be well illustrated by second-order kinetics and Freundlich isotherm models. The La³⁺-adsorbed CLIT could be recycled only by rinsing with 10 °C cold water, with a desorption rate of 96.72%. After ten cycles of adsorption-desorption, CLIT retained good adsorption capability. In the solution containing six ions, the adsorption coefficients k_La3+/Mn+ of CLIT were 2.04–3.51 times that of non-imprinted hydrogel, with k_La3+/Y3+, k_La3+/Gd3+, k_La3+/Al3+, k_La3+/Fe3+ and k_La3+/Cu2+ being 1.67, 2.04, 3.15, 2.72 and 4.84, respectively.

Injectable hyaluronic acid/hydroxyapatite composite hydrogels as cell carriers for bone repair

The natural polysaccharide/hydroxyapatite hydrogels are of great interest to bone tissue engineering, but the interfacial mismatch between rigid hydroxyapatite and soft polysaccharide phase in these hydrogels remains unsolved, which is unfavorable to achieving uniform dispersion of hydroxyapatite particles in the hydrogel matrices. Herein, hyaluronic acid (Hya), an extracellular matrix constituent, was chosen as the template for biological mineralization to synthesize Hya/hydroxyapatite hybrid particles (HAHs). The oxidized Hya/hydroxyapatite hybrid particles (OHAHs) were obtained by oxidating the Hya in the HAHs. These OHAHs were the ball-flower particles hybridized with ca. 22 % oxidized Hya. Then, different concentrations of OHAHs were introduced to prepare hydroxyapatite composite hydrogels (HCH) via Schiff-base reaction of oxidized Hya and carboxymethyl chitosan. The injectability and self-healing of HCH were evaluated and the introduction of OHAHs significantly increased the storage modulus. The gelation time of HCH showed a negative relation with the concentration of OHAHs while the storage modulus presented a positive correlation. MTT assays and live/dead staining of L929 cells co-cultured with HCH confirmed that the hydrogels had excellent cytocompatibility, and supported the adhesion and proliferation of cells under the three-dimension culture conditions. These injectable self-healing hydrogels suitable for cell encapsulation were potentially useful for bone defect repair.

Proteomics-based analysis of potential therapeutic targets in patients with peritoneal dialysis-associated peritonitis

BACKGROUND

Peritoneal dialysis-associated peritonitis (PDAP) is the most common complication in peritoneal dialysis patients. We propose screening for characteristic expressed proteins in the dialysate of PDAP patients to provide clues for the diagnosis of PDAP and its therapeutic targets.

METHODS

Dialysate samples were collected from patients with a first diagnosis of PDAP (n = 15) and from patients who had not experienced peritonitis (Control, n = 15). Data-independent acquisition (DIA) proteomic analysis was used to screen for differentially expressed proteins (DEPs). Co-expression networks were constructed via weighted gene co-expression network analysis (WGCNA) for detection of gene modules. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used for functional annotation of DEPs and gene modules. Hub proteins were validated using the parallel reaction monitoring (PRM) method.

RESULTS

A total of 142 DEPs in the dialysate of PDAP patients were identified. 70 proteins were upregulated and 72 proteins were downregulated. GO and KEGG analysis showed that DEPs were mainly enriched in cell metabolism, glycolysis/glycogenesis and hypoxia-inducible factor-1 signaling pathway. Subsequently, a co-expression network was constructed and four gene modules were detected. Myeloperoxidase (MPO) and myeloperoxidase (HP) were the key proteins of the blue and turquoise modules, respectively. Additionally, PRM analysis showed that the expression of MPO and HP was significantly upregulated in the PDAP group compared to the non-peritonitis group, which was consistent with our proteomics data.

CONCLUSION

MPO and HP were differentially expressed in the dialysate of PDAP patients and may be potential diagnostic and therapeutic targets for PDAP.

The association between diabetes coexisting with low levels of high-density lipoprotein cholesterol and peritoneal dialysis-related peritonitis

BACKGROUND

Low levels of high-density lipoprotein cholesterol (HDL-C) and diabetes are common in patients undergoing peritoneal dialysis (PD). The aim of this study was to investigate the association between the coexistence of diabetes with a low level of HDL-C and the first episode of peritoneal dialysis-related peritonitis (PDRP) in patients with PD.

METHODS

We retrospectively investigated patients with PD from January 1, 2003, to May 31, 2020, in four PD centers. Patients with PD were divided into four groups: no comorbidities, low HDL-C only, diabetes only, and diabetes plus low HDL-C. The clinical and laboratory baseline data of the four groups were collected and compared. The association between diabetes coexisting with low HDL-C levels and the first episode of PDRP was analyzed by multivariate Cox regression analysis.

RESULTS

A total of 1013 patients with PD were included in our study. The mean age was 49.94 ± 14.32 years, and 597 (58.99%) patients were males. A total of 301 (29.7%) patients had their first episodes of PDRP, and low HDL-C levels coexisted with diabetes in 72 patients with PD. After adjusting for confounding factors, a low level of HDL-C coexisting with diabetes was significantly associated with the first episode of PDRP in our study (hazard ratio: 2.81, 95% CI 1.32 ~ 4.73, p = 0.005). The associations among HDL-C, diabetes and PDRP were consistent in the following subgroups: sex, age, and pre-existing CVD (all P interaction > 0.05).

CONCLUSIONS

Patients with both diabetes and low HDL-C levels were at higher risk for PDRP in patients with PD.

[Construction and application of home self-sampling processes for cervical human papillomavirus detection]

To construct and develop the home self-sampling processes of cervical human papillomavirus (HPV) detection and evaluate its application effect. An integrated HPV self-sampling detection platform is scheduled to include three terminals: a user terminal, a detection terminal and a medical terminal. It covers a wide range of functions of self-sampling kit acquisition of user, sample logistics tracking, inspection services, report query, medical consultation, health management, and follow-up tracking. A total of 8 053 users applied for self-sampling kits and all completed online user information registration from January to November 2020. The average age of users ranged from 17 to 84 with a median age of 42 years old. Registered users of the platform were distributed in Jiangsu, Jiangxi, Hebei, Shanxi, Shanghai, Ningxia, Anhui, Zhejiang, Inner Mongolia, Beijing and Xinjiang. 8 045 users completed self-sampling with a kit return rate of 99.9%. Six users lost the kits during the express delivery, and 2 users had the kits contaminated due to improper application; The amount of exfoliated cells collected from 8 045 cases in the sample kits were all within the endogenous internal standard of the nucleic acid kit, and the qualified rate of kits was 100%. The proportion of test report issued by the detection platform within 3 d accounts for 96.93% (7 799/8 054). Among the 763 positive users, 742 completed 6-month reexamination, with a reexamination rate of 97.25%. Unfortunately, 21 cases were lost to follow-up. Taken together, HPV home-based self-sampling is simple, convenient and efficient in use. It can expand the coverage of cervical cancer screening and may help promote HPV screening.

Ectopia cordis with a double outlet right ventricle, large ventricular septal defect, malposed great arteries and left ventricular hypoplasia

Ectopia cordis, defined as partial or complete displacement of the heart outside of the thoracic cavity, is a rare congenital malformation. If not surgically corrected during the early years of life, ectopia cordis can prove to be a fatal abnormality. However, due to the presence of multiple intracardiac and extracardiac malformations, a corrective surgery might not always be successful. The pathology of ectopia cordis with a double outlet right ventricle, large ventricular septal defect, malposed great arteries and left ventricular hypoplasia is discussed, highlighting the complexities involved in such a rare disorder.

Impact of donor cardiopulmonary resuscitation on pediatric heart transplant outcome

Mortality is the highest of any solid organ in pediatric patients awaiting heart transplantation. Strategies to increase the donor pool are needed if survival to transplant is to improve. There can be reluctance to accept pediatric hearts for transplantation if the donor has received cardiopulmonary resuscitation (CPR). This study asked if donor CPR impacts the survival of pediatric heart transplant recipients. Analysis of the UNOS database was performed for all cardiac transplants performed in patients aged 0-18 yr, with donors classified as to whether they received CPR (CPR+) or not (CPR-). We compared overall survival and survival at 30 days, one yr, and five yr between groups. Within the CPR+ group, the impact of duration of CPR on survival was compared. The need for inotropic support and ejection fraction was compared between donor groups as a measure of organ function. Overall survival and survival at 30 days, one yr, and five yr did not differ in the CPR+ compared to the CPR- group. Within the CPR+ group, duration of CPR was unrelated to post-transplant survival. The need for inotropic support at procurement was similar, and ejection fraction did not differ between the CPR+ and CPR- groups. Donor CPR does not have a negative impact on pediatric heart transplant survival.

Perioperative renal failure in pediatric heart transplant recipients: outcome and risk factors

PRF is encountered in 10-13% of adult heart transplants. Only one study of a single center's experience with PRF has been reported in pediatric patients. This study examines the effect of PRF on pediatric heart transplant outcome using the UNOS database. A total of 3598 patients met inclusion criteria, of whom 254 (7%) had PRF. The PRF group comprised 31 recipients requiring PRE and 223 recipients requiring POST. Compared with No-PRF patients, PRE patients had similar survival rate and POST patients had decreased survival rate at 30 days, one, five, and 10-yr post-transplant (p < 0.001). PRF patients also had significantly lower graft survival at one, five, and 10 yr (p < 0.001). Risk factors for developing PRF included ECMO, ventilator, and inotropic support at listing and CHD as the listing diagnosis. PRF increased the duration of hospital stay and the incidence of chronic severe renal dysfunction. PRF that requires POST (whether or not it began pretransplant) has a significant negative impact on pediatric heart transplant outcome. Specific characteristics identify patients at particular high risk of developing PRF.

Low donor-to-recipient weight ratio does not negatively impact survival of pediatric heart transplant patients

A major limitation to success in pediatric heart transplantation is donor organ shortage. While the use of allografts from donors larger than the recipient is accepted, the use of undersized donor grafts is generally discouraged. Using the UNOS database, we wanted to evaluate whether using smaller donor hearts affects the short- and long-term survival of pediatric heart transplant patients. A retrospective analysis of data entered into the UNOS database from April 1994 to May 2008 was performed. Pediatric heart transplant recipients (ages 0-18 yr) with DRWR <2.0 were identified and divided into two groups: Low-DRWR (<0.8) and Ideal-DRWR (0.8-2.0). Patients' demographics, pretransplant diagnoses, age at transplantation, severity of pretransplant condition, and rate of complications prior to hospital discharge after transplantation were noted. Fisher's exact, chi-square, and Wilcoxon rank sum tests were used to compare patients' baseline characteristics. Kaplan-Meier curves and Cox proportional hazard regression were used to compare patients' survival and to identify independent risk factors for outcomes. There were 3048 patients (204 with Low- and 2844 with Ideal-DRWR). The Low-ratio group patients were older (8.3 vs. 6.9 yr; p = 0.001), there was a slight male predominance in the Low-DRWR group (p = 0.055). The Low-DRWR group had longer transplant wait time than the Ideal-DRWR group (97 vs. 85 days; p = 0.04). The groups did not differ in race, primary diagnoses, severity of pretransplant condition (medical urgency status, need for ventilation, inotropic support, ECMO, nitric oxide, or dialysis, the PVR for those with bi-ventricular anatomy), or post-transplant complications (length of stay, need for inotropic support, dialysis, and rate of infections). The Low-DRWR patients had less episodes of acute rejection during the first-post-transplant month. Infants with DRWR 0.5-0.59 had lower 30-day survival rate (p = 0.045). There was no difference in short- and long-term survival between the patients with DRWR 0.6-0.79 and DRWR 0.8-2.0. Use of smaller allografts (DRWR 0.6-0.8) has no negative impact on the short- and long-term survival of pediatric heart transplant patients.

Echocardiographic evaluation of pressure gradient across the stent in patients treated for coarctation of the aorta

OBJECTIVE

Stent placement has become a widely used method of treatment for coarctation of the aorta (COA). Our goal was to find echocardiographic indices that would correlate best with directly measured gradients across the coarctation stent.

MATERIAL AND METHODS

Pediatric patients with COA who underwent intra-aortic stent placement were evaluated. Patients with more than mild aortic insufficiency were excluded. Aortic pressures above and below the coarctation site were directly measured in the catheterization laboratory. Echocardiography was performed the next morning. Continuous and Pulse Doppler systolic velocity profiles proximal and distal to the stent were recorded. Statistical analysis included Pearson's correlation coefficients and linear regression between the directly measured pressure gradient and strongest correlated factor.

RESULT

Thirty-four patients (F : M = 15 : 19) were included in the study. The directly measured gradients (DPG) had only weak positive correlations with Doppler peak velocities (r = 0.38, P= .027) or pressure gradients (r = 0.37, P= .03) across the stent. However, there was a strong positive correlation of the directly measured gradients with the continuous wave peak systolic velocity half-time indexed to heart rate (T) (r = 0.62, P= .03), and with the squared early diastolic velocity (V(d) (2)) (r = 0.073, P < .0001). When these two parameters were combined, a linear regression equation DPG = 0.06T + 1.58 V(d) (2)- 8.05 showed very strong relations (r = 0.81, P < .0001). A simplified equation DPG = 1.98V(d) (2)+ 0.77 also accurately described the relations between the directly measured gradients and squared Doppler-measured early diastolic velocity (r = 0.71, P= .0002).

CONCLUSIONS

A simple echocardiographic index DPG = 1.98V(d) (2)+ 0.77, where DPG is the pressure gradient across the stent, and V(d) is the early Doppler diastolic velocity, accurately describes relations between the gradient across the stent and echocardiographic data and should be used for evaluation of patients with stent-corrected COA.

Intermediate follow-up following intravascular stenting for treatment of coarctation of the aorta

BACKGROUND

We report a multiinstitutional study on intermediate-term outcome of intravascular stenting for treatment of coarctation of the aorta using integrated arch imaging (IAI) techniques.

METHODS AND RESULTS

Medical records of 578 patients from 17 institutions were reviewed. A total of 588 procedures were performed between May 1989 and Aug 2005. About 27% (160/588) procedures were followed up by further IAI of their aorta (MRI/CT/repeat cardiac catheterization) after initial stent procedures. Abnormal imaging studies included: the presence of dissection or aneurysm formation, stent fracture, or the presence of reobstruction within the stent (instent restenosis or significant intimal build-up within the stent). Forty-one abnormal imaging studies were reported in the intermediate follow-up at median 12 months (0.5-92 months). Smaller postintervention of the aorta (CoA) diameter and an increased persistent systolic pressure gradient were associated with encountering abnormal follow-up imaging studies. Aortic wall abnormalities included dissections (n = 5) and aneurysm (n = 13). The risk of encountering aortic wall abnormalities increased with larger percent increase in CoA diameter poststent implant, increasing balloon/coarc ratio, and performing prestent angioplasty. Stent restenosis was observed in 5/6 parts encountering stent fracture and neointimal buildup (n = 16). Small CoA diameter poststent implant and increased poststent residual pressure gradient increased the likelihood of encountering instent restenosis at intermediate follow-up.

CONCLUSIONS

Abnormalities were observed at intermediate follow-up following IS placement for treatment of native and recurrent coarctation of the aorta. Not exceeding a balloon:coarctation ratio of 3.5 and avoidance of prestent angioplasty decreased the likelihood of encountering an abnormal follow-up imaging study in patients undergoing intravascular stent placement for the treatment of coarctation of the aorta. We recommend IAI for all patients undergoing IS placement for treatment of CoA.

Procedural results and acute complications in stenting native and recurrent coarctation of the aorta in patients over 4 years of age: a multi-institutional study

BACKGROUND

We report a multi-institutional experience with intravascular stenting (IS) for treatment of coarctation of the aorta.

METHODS AND RESULTS

Data was collected retrospectively by review of medical records from 17 institutions. The data was broken down to prior to 2002 and after 2002 for further analysis. A total of 565 procedures were performed with a median age of 15 years (mean=18.1 years). Successful reduction in the post stent gradient (<20 mm Hg) or increase in post stent coarctation to descending aorta (DAo) ratio of >0.8 was achieved in 97.9% of procedures. There was significant improvement (P<0.01) in pre versus post stent coarctation dimensions (7.4 mm+/-3.0 mm vs. 14.3+/-3.2 mm), systolic gradient (31.6 mm Hg+/-16.0 mm Hg vs. 2.7 mm Hg+/-4.2 mm Hg) and ratio of the coarctation segment to the DAo (0.43+/-0.17 vs. 0.85+/-0.15). Acute complications were encountered in 81/565 (14.3%) procedures. There were two procedure related deaths. Aortic wall complications included: aneurysm formation (n=6), intimal tears (n=8), and dissections (n=9). The risk of aortic dissection increased significantly in patients over the age of 40 years. Technical complications included stent migration (n=28), and balloon rupture (n=13). Peripheral vascular complications included cerebral vascular accidents (CVA) (n=4), peripheral emboli (n=1), and significant access arterial injury (n=13). Older age was significantly associated with occurrence of CVAs. A significant decrease in the technical complication rate from 16.3% to 6.1% (P<0.001) was observed in procedures performed after January 2002.

CONCLUSIONS

Stent placement for coarctation of aorta is an effective treatment option, though it remains a technically challenging procedure. Technical and aortic complications have decreased over the past 3 years due to, in part, improvement in balloon and stent design. Improvement in our ability to assess aortic wall compliance is essential prior to placement of ISs in older patients with coarctation of the aorta.

Copper transportion of WD protein in hepatocytes from Wilson disease patients in vitro

AIM

To study the effect of copper transporting P-type ATPase in copper metabolism of hepatocyte and pathogenesis of Wilson disease (WD).

METHODS

WD copper transporting properties in some organelles of the cultured hepatocytes were studied from WD patients and normal controls.These cultured hepatocytes were incubated in the media of copper 15 mg x L(-1) only, copper 15 mg x L(-1) with vincristine (agonist of P-type ATPase) 0.5mg x L(-1), or copper 15 mg x L(-1) with vanadate (antagonist of P-type ATPase) 18.39 mg x L(-1) separately. Microsome (endoplasmic reticulum and Golgi apparatus), lysosome, mitochondria, and cytosol were isolated by differential centrifugation. Copper contents in these organelles were measured with atomic absorption spectrophotometer, and the influence in copper transportion of these organelles by vanadate and vincristine were comparatively analyzed between WD patients and controls. WD copper transporting P-type ATPase was detected by SDS-PAGE in conjunction with Western blot in liver samples of WD patients and controls.

RESULTS

The specific WD proteins (M(r)155,000 lanes) were expressed in human hepatocytes, including the control and WD patients. After incubation with medium containing copper for 2 h or 24 h, the microsome copper concentration in WD patients was obviously lower than that of controls, and the addition of vanadate or vincristine would change the copper transporting of microsomes obviously. When incubated with vincristine, levels of copper in microsome were significantly increased, while incubated with vanadate, the copper concentrations in microsome were obviously decreased. The results indicated that there were WD proteins, the copper transportion P-type ATPase in the microsome of hepatocytes. WD patients possessed abnormal copper transporting function of WD protein in the microsome, and the agonist might correct the defect of copper transportion by promoting the activity of copper transportion P-type ATPase.

CONCLUSION

Copper transportion P-type ATPase plays an important role in hepatocytic copper metabolism. Dysfunction of hepatocytic WD protein copper transportion might be one of the most important factors for WD.

Modeling of fugitive dust emission for construction sand and gravel processing plant

Due to rapid economic development in Taiwan, a large quantity of construction sand and gravel is needed to support domestic civil construction projects. However, a construction sand and gravel processing plant is often a major source of air pollution, due to its associated fugitive dust emission. To predict the amount of fugitive dust emitted from this kind of processing plant, a semiempirical model was developed in this study. This model was developed on the basis of the actual dust emission data (i.e., total suspended particulate, TSP) and four on-site operating parameters (i.e., wind speed (u), soil moisture (M), soil silt content (s), and number (N) of trucks) measured at a construction sand and gravel processing plant. On the basis of the on-site measured data and an SAS nonlinear regression program, the expression of this model is E = 0.011.u2.653.M-1.875.s0.060.N0.896, where E is the amount (kg/ton) of dust emitted during the production of each ton of gravel and sand. This model can serve as a facile tool for predicting the fugitive dust emission from a construction sand and gravel processing plant.

Robotically assisted video-enhanced-endoscopic coronary artery bypass graft surgery

Since 1988, through fierce industry-driven competition and patients' preference for minimally invasive procedures, widely diffused through the media, laparoscopic cholecystectomy was universally adopted and rapidly became the "gold standard" for symptomatic cholelithiasis. Robotically assisted video enhanced-endoscopic coronary artery bypass surgery (RAVE-CABG) will most likely follow suit with its similar developmental processes for symptomatic coronary artery disease. Since 1998, there are currently two surgical robotic systems that have been used in a clinical setting for endoscopic coronary artery bypass (ECABG): the da Vinci and the ZEUS system. Although each has separate learning curves to overcome, as with any new technology, both offer the promise to contribute in the interests of reduced hospital days, earlier return to normal activity, less pain, better cosmesis, and the rethinking of surgical dogma such as wide exposure.

Daily rhythms in a complex operant: targeted percentile shaping of run lengths in rats

Daily rhythms in response output and accuracy were examined when reinforcement for a complex operant was uncoupled from accuracy of performance. Rats housed in operant conditioning chambers earned their daily ration of food under a targeted percentile procedure for responding on two levers. The targeted pattern was a series of consecutive responses on the left lever (a "run"), followed by a single response on the right lever. The targeted run length was either "O" (i.e., undefined, under the nondifferential baseline), 6, 12 or 24. Under baseline, a random third of all trials ended in pellet delivery; under the percentile conditions, trials with runs closer to the target than two-thirds of the runs from the most recent 24 trials ended in pellet delivery. This contingency shaped run lengths while ensuring that approximately one-third of all trials produced pellets. Responding tracked the target value well, with mean obtained run lengths equal to 90% of the target or better. Daily rhythms were clearly evident in measures of overall output, with subjects responding primarily 3-7 h into the dark period. The only substantial light-period responding observed in all subjects occurred during the 2 h after noon, when the chambers were serviced. No systematic variation in this pattern was observed as a function of target. Run length was much less variable across the daily cycle than was response output, with only a suggestion under the longest target that response accuracy was lower during periods removed from the period of peak activity.