Using incognito standardised patients to evaluate quality of eye care in China.

BACKGROUND/AIMS: Few studies have objectively examined the quality of eye care in China. We assessed refractive care using the incognito standardised patient (SP) approach, a gold standard for evaluating clinical practice. METHODS: A total of 52 SPs were trained to provide standardised responses during eye examinations, and underwent automated and non-cycloplegic, subjective refraction by a senior ophthalmologist from Zhongshan Ophthalmologic Center, a national-level clinical and research centre. SPs subsequently received subjective refraction and eye exams at a randomly selected sample of 40 public hospitals and 93 private optical shops in Shaanxi, Northwestern China. Difference between expert and local refraction in the better-seeing eye was calculated by the vector diopteric method, and completeness of exams assessed against national standards. SP and provider demographic information and provider clinical experience were recorded. RESULTS: SPs (n=52, mean (range) age, 25.7 (22-31) years, 28.8% male) underwent 133 eye exams (mean total duration 15.0±11.7 min) by 133 local refractionists (24-60 years, 30.3% male). Only 93 (69.9%), 121 (91.0%) and 104 (78.2%) of local refractionists assessed vision, automated and subjective refraction, respectively. The median inaccuracy was -0.25 diopters (D), while 25.6% of results differed by an absolute value of ≥1.0 D and 6.0% by ≥2.0 D. Predictors of inaccurate refraction included spectacle power <-6.0 D (OR=2.66; 95% CI, 1.27 to 5.56), service at a public (vs private) hospital (OR=2.01; 95% CI, 1.11 to 3.63) and provider male sex (OR=2.03; 95% CI, 1.11 to 3.69). CONCLUSION: Inaccurate refractions are common in Northwestern China, particularly in public facilities. Important assessments, including subjective refraction, are frequently omitted.

Asymmetric dimethylarginine compartmental behavior during high-flux hemodialysis.

AIM: The accumulation of uremic toxins, such as asymmetric dimethylarginine (ADMA), has emerged as one of the major cardiovascular disease-related risk factors in patients with end-stage renal disease (ESRD). Based on the low molecular weight of ADMA, hemodialysis (HD) should theoretically effectively remove ADMA. In this study, we investigated the clearance behavior of ADMA during high-flux HD. METHODS: Eight HD patients without residual renal function were included. Blood samples were collected at 0, 30, 60, 120 and 240 min after dialysis started, as well as 1 h and 48 h after dialysis. ADMA level was detected by HPLC-MS/MS. Herein, the ADMA level in blood cells and the ADMA protein binding rate were measured. Accordingly, the dialyzer extraction ratio was also determined. RESULTS: The reduction ratio (RR) of ADMA (corrected for hemoconcentration) was significantly lower, at only 37.21 ± 6.44%, than that of urea and creatinine (p < .05). Interestingly, its clearance from plasma was precipitous early in dialysis and became slowly from 60 to 240 min. Additionally, a greater inlet erythrocyte than plasma concentration was found for ADMA. The dialyzer extraction ratio was comparable between ADMA and creatinine or urea (83 ± 5% for ADMA vs. 84 ± 3% and 88 ± 2% for creatinine and urea, respectively; both p>.05). Urea and creatinine had a slight rebound ratio of less than 10% at 1 h after the completion of HD. In contrast, considerable rebound of approximately 30% was detected in ADMA. CONCLUSION: This study suggests that ADMA may present a multicompartmental distribution that cannot be representatively reflected by the urea kinetics model.

[Association between the introducing time of complementary food and growth of infants and young children in poor rural areas in Shaanxi Province].

OBJECTIVE: To study the introducing time of complementary food in poor rural areas and its association with the growth of infants and young children. METHODS: In total of 1802 infants and young children aged 6-12 months from 11 poverty counties in southern Shaanxi Province were selected by stratified random cluster sampling. These infants were surveyed four times, and once every 6 months. Data on complementary feeding for children were collected through the questionnaires. Cognitive development was measured by BSID. Body weight and length for them were measured using standard gauges to generate height for age Z score( HAZ), weight for age Z score( WAZ) and weight for height Z score( WHZ). The analysis of variance was used to identify the association between the introducing time of complementary food and growth of children. RESULTS: at baseline, only 32. 93% of children were introduced complementary food at the age of 6 months. This study indicated that the introducing time of complementary food was significantly associated with the cognitive development in the longer run. The third and fourth survey showed that children with introducing complementary food after 6 months of age( mental development index were 81. 24 and78. 40 respectively) had significantly lower cognitive development ability( F = 11. 86, P<0. 05; F = 4. 24, P< 0. 05). There were no long-term significant correlation between the introducing time of complementary food and WAZ, HAZ and WHZ. CONCLUSION: There are still lots of children that were not feeding reasonably in poor rural China. The introducing time of complementary food is related to growth of infants and young children.

Laboratory Evolution Assays and Whole-Genome Sequencing for the Development and Safety Evaluation of Lactobacillus plantarum With Stable Resistance to Gentamicin.

The goal of this work was to use laboratory evolution assays and whole-genome sequencing to develop and test the safety of a probiotic, Lactobacillus plantarum, with high-level of resistance to gentamicin. The evolution of L. plantarum was evaluated under the selective pressure from gentamicin and subsequently when the selective pressure was removed. After 30 days of selective pressure from gentamicin, the minimum inhibitory concentration (MIC) of L. plantarum to gentamicin increased from 4 to 512 µg/mL and remained stable at this level. After removing the selective pressure, the resistance of L. plantarum to gentamicin decreased to 64 µg/mL after 20 days, and remained stable thereafter. Although the MIC declined it was still higher than the cut-off value recommended by EFSA, indicating that the acquisition of gentamicin-resistance was an irreversible process. Using whole-genome sequencing, gene mutations were identified in the strains that had undergone selection pressure from gentamicin as well as in the strains where the selection pressure was subsequently removed. Specifically, four non-synonymous mutations were detected including one single nucleotide polymorphism (SNP), one insertion, and two structural variants (SVs), of which the mutations in genes encoding the drug resistance MFS transporter and transcriptional regulator of AraC family were only detected in the strains under selective pressure from gentamicin. The results indicate that these mutations play an important role in increasing the resistant levels of L. plantarum to gentamicin. The mobility analysis of mutant genes confirmed that they were not located on mobile elements of the genome of highly resistant L. plantarum, indicating that horizontal gene transfer was not possible.

Whole-genome sequencing reveals the mechanisms for evolution of streptomycin resistance in Lactobacillus plantarum.

In this research, we investigated the evolution of streptomycin resistance in Lactobacillus plantarum ATCC14917, which was passaged in medium containing a gradually increasing concentration of streptomycin. After 25 d, the minimum inhibitory concentration (MIC) of L. plantarum ATCC14917 had reached 131,072 µg/mL, which was 8,192-fold higher than the MIC of the original parent isolate. The highly resistant L. plantarum ATCC14917 isolate was then passaged in antibiotic-free medium to determine the stability of resistance. The MIC value of the L. plantarum ATCC14917 isolate decreased to 2,048 µg/mL after 35 d but remained constant thereafter, indicating that resistance was irreversible even in the absence of selection pressure. Whole-genome sequencing of parent isolates, control isolates, and isolates following passage was used to study the resistance mechanism of L. plantarum ATCC14917 to streptomycin and adaptation in the presence and absence of selection pressure. Five mutated genes (single nucleotide polymorphisms and structural variants) were verified in highly resistant L. plantarum ATCC14917 isolates, which were related to ribosomal protein S12, LPXTG-motif cell wall anchor domain protein, LrgA family protein, Ser/Thr phosphatase family protein, and a hypothetical protein that may correlate with resistance to streptomycin. After passage in streptomycin-free medium, only the mutant gene encoding ribosomal protein S12 remained; the other 4 mutant genes had reverted to the wild type as found in the parent isolate. Although the MIC value of L. plantarum ATCC14917 was reduced in the absence of selection pressure, it remained 128-fold higher than the MIC value of the parent isolate, indicating that ribosomal protein S12 may play an important role in streptomycin resistance. Using the mobile elements database, we demonstrated that streptomycin resistance-related genes in L. plantarum ATCC14917 were not located on mobile elements. This research offers a way of combining laboratory evolution techniques and whole-genome sequencing for evaluating antibiotic resistance in probiotics.

Functional metabotropic glutamate receptors 1 and 5 are expressed in murine podocytes.

In non-neuronal cells, glutamate is an extracellular signaling mediator. Since podocytes have glutamate-containing vesicles, we sought to determine glutamate receptor presence and action in glomerular cells. The metabotropic glutamate receptors (mGluR) 1, 5, 6, and 8 were found to be expressed in mouse brain and glomeruli; predominantly in podocytes. In two models of proteinuria (BalB/C mice with puromycin aminonucleoside- and doxorubicin-induced podocyte injury) we found that the selective mGluR1/5 agonist (S)-3,5-dihydroxyphenylglycine (DHPG) attenuated albuminuria and improved the expression of the podocyte marker WT-1. TUNEL staining showed that the number of podocytes undergoing apoptosis was inversely correlated with the number of WT-1-positive cells in glomeruli. When podocytes were treated with DHPG in vitro, they generated cyclic AMP and activated CREB (cyclic AMP response element binding protein). The selective mGluR1/5 antagonist (RS)-1-aminoindan-1,5-dicarboxylic acid, the adenylate cyclase inhibitor SQ22536, and RNA interference knockdown of mGluR1 or mGluR5 all prevented DHPG-induced cAMP generation and CREB activation. DHPG inhibited apoptosis and the decrease of aminonucleoside-induced mitochondrial membrane potential in podocytes but had no effect in the presence of SQ22536 with knockdown mGluR1 or mGluR5. Thus, functional mGluR1 and mGluR5 are expressed in podocytes and their activation protects against albuminuria and podocyte apoptosis, processes that are, at least in part, dependent on cAMP.

[Analysis of incidence and risk factor in hospitalized patients with acute kidney injury].

OBJECTIVE: To investigate the epidemiology and the risk factors of acute kidney injury (AKI) in hospitalized patients in order to help clinicians better understand and prevent AKI. METHODS: All patients hospitalized in Renji Hospital of Shanghai Jiao Tong University, which is a three-level General Hospital in Shanghai, during January to December of 2008 were screened by Lab Administration Network. Study group was comprised of the patients with full clinical data of AKI, as defined by Acute Kidney Injury Network (AKIN). The incidence, etiology and distribution characteristics of hospitalized patients with AKI were retrospectively analyzed. Logistic regression analysis was used to investigate the risk factors in severity of AKI. RESULTS: Nine hundred and thirty-four patients suffering from AKI for 1 001 episodes were enrolled. The incidence of AKI in hospitalized patients was 2.4% (934/38 734). The ratio of male to female was 1.88:1. The mean age was (60.82 ± 16.94) years old. Higher incidence was seen with an increase in age. Three hundred and thirty-one(35.4%) patients with AKI were found in medical department, 592(63.4%) patients in surgical department and 11(1.2%) patients in department of gynecologic and obstetrics. Analysis of the causes of AKI showed that pre-AKI accounted for 52.0%, followed by renal parenchyma AKI (44.7%) and postrenal AKI (3.3%). The most common reason for AKI was acute tubular necrosis (ATN, 37.5%), followed by absolute (33.6%) and relative inadequacy of blood volume (13.4%). Multivariate logistic regression analysis showed that chronic kidney disease (CKD) [odds ratio (OR)=2.085, 95% confidence interval (95%CI): 1.536-2.830,P<0.01], renal injurious drugs (OR=1.438, 95%CI: 1.087-1.901 ,P<0.05), and failure of organs other than kidney (OR=1.327, 95%CI: 1.014-1.737,P<0.05) were independent risk factors for stage II-III AKI. CONCLUSION: AKI is one of the most common clinical syndromes in hospitalized patients. With the increase of age, the incidence increases gradually. The most common reasons for hospitalized AKI are pre-AKI and ATN. CKD, renal injurious drugs and failure of other organs are independent risk factors of medium to serious AKI.

Metabolite profiling of hemodialysate using gas chromatography time-of-flight mass spectrometry.

Hemodialysis is an important alternative for renal replacement therapy to remove uremic retention solutes (URS) for the uremic syndrome. The metabolites in the hemodialysate directly reflect the efficiency of URS clearance. Here we report a highly sensitive and reliable metabolomic procedure for the measurement of small molecule metabolites in hemodialysate using gas chromatography coupled with time-of-flight mass spectrometry (GC/TOF/MS). The method was developed and evaluated through orthogonal experimental design using multivariate statistical analysis. The optimized method involves the use of methanol and water in the ratio of 3:1 (v/v) for dissolving the lyophilized solid of the hemodialysate after degradation of urea with urease (no less than 50U) for 10min. Validation of the method demonstrated a good linearity with regression coefficients greater than 0.99. Relative standard deviations of precision and stability of proposed method were less than 15%, and recoveries ranged from 71.8 to 115.8%. This method was successfully applied in the metabolite profiling of human hemodialysate samples which was able to differentiate the patients treated with high-flux hemodialysis from those with low-flux hemodialysis. The metabolomic results reveal a higher concentration of URS, and thus, better URS removal, from the patients under high-flux dialysis than those under low-flux dialysis.