Late creation of vascular access increased post-hemodialysis mortality, hospitalization, and health-care expenditure: A population-based cohort study in Taiwan.

BACKGROUND/PURPOSE: The optimal timing of vascular access (VA) creation for hemodialysis (HD) and whether this timing affects mortality and health-care utilization after HD initiation remain unclear. Thus, we conducted a population-based study to explore their association. METHODS: We used Taiwan's National Health Insurance Research Database to analyze health-care outcomes and utilization in a cohort initiating HD during 2003-2013. We stratified patients by the following VA creation time points: >180, 91-180, 31-90, and ≤30 days before and ≤30 days after HD initiation and examined all-cause mortality, ambulatory care utilization/costs, hospital admission/costs, and total expenditure within 2 years after HD. Cox regression, Poisson regression, and general linear regression were used to analyze mortality, health-care utilization, and costs respectively. RESULTS: We identified 77,205 patients who started HD during 2003-2013. Compared with the patients undergoing VA surgery >180 days before HD initiation, those undergoing VA surgery ≤30 days before HD initiation had the highest mortality-15.92 deaths per 100-person-years, crude hazard ratio (HR) 1.56, and adjusted HR 1.28, the highest hospital admissions rates- 2.72 admission per person-year, crude rate ratio (RR) 1.48 and adjusted RR 1.32, and thus the highest health-care costs- US$31,390 per person-year, 7% increase of costs and 6% increase with adjustment within the 2-year follow-up after HD initiation. CONCLUSIONS: Late VA creation for HD can increase all-cause mortality, hospitalization, and health-care costs within 2 years after HD initiation. Early preparation of VA has the potential to reduce post-HD mortality and healthcare expenses for the ESKD patients.

Ultrasound-Driven Piezoelectrocatalytic Immunoactivation of Deep Tumor.

Tumor heterogeneity makes routine drugs difficult to penetrate solid tumors, limiting their therapy efficacies. Based on high tissue penetrability of hydrogen molecules (H2 ) and ultrasound (US) and the immunomodulation effects of H2 and lactic acid (LA), this work proposes a novel strategy of US-driven piezoelectrocatalytic tumor immunoactivation for high-efficacy therapy of deep tumors by piezoelectrocatalytic hydrogen generation and LA deprivation. A kind of US-responsive piezoelectric SnS nanosheets (SSN) is developed to realize US-triggered local hydrogen production and simultaneous LA deprivation in deep tumors. The proof-of-concept experiments which are executed on an orthotopic liver cancer model have verified that intratumoral SSN-medicated piezoelectrocatalytically generated H2 liberates effector CD8+ T cells from the immunosuppression of tumor cells through down-regulating PD-L1 over-expression, and simultaneous LA deprivation activates CD8+ T cells by inhibiting regulatory T cells, efficiently co-activating tumor immunity and achieving a high outcome of liver tumor therapy with complete tumor eradication and 100% mice survival. The proposed strategy of US-driven piezoelectrocatalytic tumor immunoactivation opens a safe and efficient pathway for deep tumor therapy.

microRNA-660 Enhances Cisplatin Sensitivity via Decreasing SATB2 Expression in Lung Adenocarcinoma.

Increasing evidence suggests that microRNAs' (miRNAs) abnormal expression is one of the main factors of chemotherapy resistance in various cancers. However, the role of miRNAs in lung adenocarcinoma (LUAD) resistance to cisplatin is still unclear. In this study, we analyzed a microarray dataset to investigate miRNAs related to cisplatin resistance in LUAD. The expression of miRNAs in LUAD tissues and cell lines was detected using real-time quantitative polymerase chain reaction (RT-qPCR). Special AT-Rich Sequence-Binding Protein 2 (SATB2) in LUAD cell lines was detected using RT-qPCR and Western blot. Cell proliferation was measured by CCK8 and colony formation assays, while cell cycle and apoptosis were measured by flow cytometry. A dual-luciferase reporter assay was performed to confirm that SATB2 is a target gene of microRNA-660 (miR-660). We showed that the expression of miR-660 was not only decreased in LUAD cells and tissues but also further decreased in the cisplatin-resistant A549 cell line. The overexpression of miR-660 increased cisplatin sensitivity in LUAD cells. In addition, we identified SATB2 as a direct target gene of miR-660. We also revealed that miR-660 increased cisplatin sensitivity in LUAD cells via targeting SATB2. In conclusion, miR-660/SATB2 axis is a key regulator of cisplatin resistance in LUAD.

Mesocrystalline ZnS nanoparticles-augmented sonocatalytic full water splitting into H2/O2 for immunoactivating deep tumor.

Therapeutic gas molecules have high tissue penetrability, but their sustainable supply and controlled release in deep tumor is a huge challenge. In this work, a concept of sonocatalytic full water splitting for hydrogen/oxygen immunotherapy of deep tumor is proposed, and a new kind of ZnS nanoparticles with a mesocrystalline structure (mZnS) is developed to achieve highly efficient sonocatalytic full water splitting for sustainable supply of H2 and O2 in tumor, achieving a high efficacy of deep tumor therapy. Mechanistically, locally generated hydrogen and oxygen molecules exhibit a tumoricidal effect as well as the co-immunoactivation of deep tumors through inducing the M2-to-M1 repolarization of intratumoral macrophages and the tumor hypoxia relief-mediated activation of CD8+ T cells, respectively. The proposed sonocatalytic immunoactivation strategy will open a new window to realize safe and efficient treatment of deep tumors.

Escherichia coli FimH adhesins act synergistically with PapGII adhesins for enhancing establishment and maintenance of kidney infection.

BACKGROUND: FimH adhesin is proposed to enhance Escherichia coli kidney infection by acting with PapGII adhesin, but genetic epidemiology study and animal study have not been widely conducted to confirm this hypothesis. METHODS: We compared the prevalence of adhesin gene and their coexistent pattern between upper and lower urinary tract infection (UTI) strains. fimH mutant (EC114FM), papGII mutant (EC114PM) and fimH/papGII double mutant (EC114DM) were constructed from a pylonephritogenic strain (EC114). We compared among these strains for the infection ability in bladders and kidneys of female BALB/c mice challenged transurethrally with these bacteria and assessed 1, 3, and 7 days after inoculation. RESULTS: Strains carrying fimH-only genotype were significantly more prevalent in lower UTI (P < 0.001). Strains carrying the fimH/papGII, but not papGII-only, were significantly associated with upper UTI (P = 0.001). Incidence of kidney infection increased after inoculation with EC114 on days 1 and 3, at both low and high dose, as compared with EC114DM; and the effect was greater than the sum of individual effect of EC114PM and EC114FM. Geometric means of quantitative bacterial counts in the kidneys significantly decreased when challenged with EC114FM on days 3 and 7, EC114PM on day 3 and EC114DM on day 1 after inoculation at high dose, as compared with EC114 (all P < 0.05). CONCLUSIONS: We confirmed the advantage and synergistic action of FimH and PapGII for E. coli kidney infection and concluded that antagonists against FimH and PapGII adhesin may prevent kidney infection and enable its management.

Serum sclerostin levels are positively related to bone mineral density in peritoneal dialysis patients: a cross-sectional study.

BACKGROUND: Sclerostin, an antagonist of the Wingless-type mouse mammary tumor virus integration site (Wnt) pathway that regulates bone metabolism, is a potential contributor of chronic kidney disease (CKD)-mineral and bone disorder (MBD), which has various forms of presentation, from osteoporosis to vascular calcification. The positive association of sclerostin with bone mineral density (BMD) has been demonstrated in CKD and hemodialysis (HD) patients but not in peritoneal dialysis (PD) patients. This study assessed the association between sclerostin and BMD in PD patients. METHODS: Eighty-nine PD patients were enrolled; their sera were collected for measurement of sclerostin and other CKD-MBD-related markers. BMD was also assessed simultaneously. We examined the relationship between sclerostin and each parameter through Spearman correlation analysis and by comparing group data between patients with above- and below-median sclerostin levels. Univariate and multiple logistic regression models were employed to define the most predictive of sclerostin levels in the above-median category. RESULTS: Bivariate analysis revealed that sclerostin was correlated with spine BMD (r = 0.271, P = 0.011), spine BMD T-score (r = 0.274, P = 0.010), spine BMD Z-score (r = 0.237, P = 0.027), and intact parathyroid hormone (PTH; r = - 0.357, P < 0.001) after adjustments for age and sex. High BMD, old age, male sex, increased weight and height, diabetes, and high osteocalcin and uric acid levels were observed in patients with high serum sclerostin levels and an inverse relation was noticed between PTH and sclerostin. Univariate logistic regression analysis demonstrated that BMD is positively correlated with above-median sclerostin levels (odds ratio [OR] = 65.61, P = 0.002); the correlation was retained even after multivariate adjustment (OR = 121.5, P = 0.007). CONCLUSIONS: For the first time, this study demonstrated a positive association between serum sclerostin levels and BMD in the PD population.

Clinical and microbiological characteristics of peritoneal dialysis-related peritonitis caused by Escherichia coli in southern Taiwan.

Peritonitis is a serious complication and major cause of treatment failure in patients undergoing peritoneal dialysis (PD). Escherichia coli is the major pathogen in extraintestinal Gram-negative infections, including PD-related peritonitis. The outcomes of E. coli peritonitis in PD varied from relatively favorable outcomes to a higher incidence of treatment failure. The aim of this study was to investigate the impact of bacterial virulence and host characteristics on the outcomes of PD-related peritonitis caused by E. coli. From January 2000 to June 2016, a total of 47 episodes of monomicrobial and 10 episodes of polymicrobial E. coli PD-related peritonitis, as well as 89 episodes of monomicrobial Gram-positive (56 Staphylococcus spp. and 33 Streptococcus spp.) PD-related peritonitis cases, were retrospectively enrolled. Clinical features, E. coli bacterial virulence, and outcomes were analyzed. Compared to Streptococcus spp. peritonitis, E. coli peritonitis had a higher peritoneal catheter removal rate (38 versus 12%; P = 0.0115). Compared to the monomicrobial group, patients in polymicrobial group were older and had higher peritoneal catheter removal rate (80 versus 38%; P = 0.0324). Treatment failure of E. coli peritonitis was associated with more polymicrobial peritonitis and immunocompromised comorbidity, longer duration of PD therapy, and more antimicrobial resistance. E. coli isolates with more iron-related genes had higher prevalence of phylogenetic group B2 and papG II, iha, ompT, and usp genes. This study demonstrates the important roles of clinical and bacterial characteristics in the outcomes of monomicrobial and polymicrobial E. coli PD-related peritonitis.

Incidence and outcomes of encapsulating peritoneal sclerosis (EPS) and factors associated with severe EPS.

BACKGROUND: Encapsulating peritoneal sclerosis (EPS) is a rare but serious complication of long-term peritoneal dialysis (PD). However, previous studies reported large variations in its mortality rates that may associate with a different degree of EPS severity. This study reports the incidence and outcomes of EPS and identifies the risk factors associated with severe EPS. METHODS: We retrospectively analyzed clinical data of EPS patients from 3 medical centers in Taiwan from January 1982 to September 2015, and classified patients as having mild/moderate or severe EPS. Patients with intractable intestinal obstruction/gut-related sepsis that needed surgical intervention or resulted in mortality were in severe EPS group. Follow-up for outcome was through December 31, 2015. Clinical characteristics, peritoneal dialysis (PD)-related parameters, biochemical and imaging results were analyzed and compared between groups. RESULTS: Fifty-eight of 3202 patients undergoing PD during the study period had EPS (prevalence 1.8%). The incidence of EPS increased for patients on PD for >6-8 years (≤6 yrs. vs. >6-8 yrs., 0.0% vs. 1.8%, p = 0.001). Relative to those on PD for >6-8 years, the risk of EPS significantly increased with PD duration longer than 10 years (>10-12 years vs. >6-8 years: OR: 5.5, 95% CI: 1.7-17.1, p < 0.01). Twenty-three patients fulfilled the criteria for severe EPS. The overall mortality rate of EPS was 35% (20/58), and was 74% (17/23) in the severe EPS group. The average serum levels of C-reactive protein (CRP) and intact-parathyroid hormone (i-PTH), which were checked every 3~6 months within one year before diagnosis of EPS, were higher in severe EPS group than in mild/moderate group (p = 0.02, p = 0.08, respectively). Multivariate analysis revealed severe EPS was independently associated with bowel tethering (based on CT), presentation with bloody ascites, diagnosis of EPS after withdrawal from PD, and i-PTH ≥ 384 pg/mL. Receiver operating characteristic analysis indicated that presentation with 2 or more of the 5 risk factors (EPS diagnosis after PD withdrawal, bloody ascites, bowel tethering, CRP ≥ 29 mg/L, and i-PTH ≥ 384 pg/mL) had a good accuracy (AUC = 0.80, p = 0.001) for prediction of severe EPS. CONCLUSIONS: The incidence of EPS increases with PD duration. Severe EPS has high mortality rate and is associated with bowel tethering, presentation of bloody ascites, diagnosis after PD withdrawal, and higher serum levels of i-PTH before EPS diagnosis. Having 2 or more of the 5 risk factors can provide a good accuracy for prediction of severe EPS.

Role of class II P fimbriae and cytokine response in the pathogenesis of Escherichia coli kidney infection in diabetic mice.

BACKGROUND: The role of class II P fimbriae (P fimbriae II) in diabetic kidney infections is uncertain, although some genetic and epidemiological studies suggest a lower prevalence of P fimbriae II genes in Escherichia coli strains isolated from diabetic patients with complicated kidney infections. METHODS: We inoculated a P fimbriae II deficient E. coli (DH5αT) or an isogenic P fimbriae II expressing transformant (DH5αTP) into the bladders of diabetic and non-diabetic BALB/C mice, and sacrificed them after 3 days. The incidence of bladder or kidney infection (≥103 CFU of E. coli per bladder or kidney), bacteremia (≥102 CFU of E. coli on blood culture plate), kidney pathological score, immunoreactive Histo-score (H-score), and corrected H-score (H-score adjusted for Log10 CFU of bacteria in the kidney) were compared among groups. RESULTS: Diabetic mice were more susceptible to bladder infection than non-diabetic mice with both transformants. The geometric mean of bacteria counts in kidneys was significantly increased only when the diabetic mice were infected with DH5αTP. Among the 4 groups of mice, diabetic mice infected with DH5αTP had the highest incidence of kidney infection and bacteremia, and the highest renal pathology scores. The IL-8 H-score and the corrected IL-6 and IL-8 H-score were significantly lower in diabetic than non-diabetic mice. CONCLUSION: We concluded that P fimbriae II contribute to the pathogenesis and severity of E. coli kidney infections in diabetic mice. An impaired cytokine response may also contribute to the increased incidence and severity of kidney infections in diabetic hosts.

Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Accelerates Pathogen Identification and May Confer Benefit in the Outcome of Peritoneal Dialysis-Related Peritonitis.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and conventional standard methods were compared for time to pathogen identification and impact on clinical outcomes in peritoneal dialysis-related peritonitis patients. The MALDI-TOF MS method identified the causative microorganisms earlier (average time saved, 64 h for all pathogens), and patients had a shorter hospital stay (mean ± standard deviation, 5.2 ± 4.8 days versus 8.2 ± 4.5 days, P = 0.001).

Clinical and microbiological characteristics of peritoneal dialysis-related peritonitis caused by Klebsiella pneumoniae in southern Taiwan.

BACKGROUND/PURPOSE(S): Gram-negative peritonitis is a frequent and serious complication of peritoneal dialysis (PD). No previous reports have focused on Klebsiella pneumoniae infection. The aim of this study was to investigate the host and bacterial factors associated with K. pneumoniae PD-related peritonitis. METHODS: We retrospectively studied K. pneumoniae PD-peritonitis cases treated at a university hospital in southern Taiwan during 1990-2011, and analyzed the clinical features and outcomes and bacterial characteristics of serotypes, hypermucoviscosity (HV), and virulence-associated genes such as wabG, uge, and rmpA in K. pneumoniae PD-related peritonitis. Fifty-four isolates of K. pneumoniae-related community-acquired urinary tract infection (UTI) and 76 morphologically different nonpathogenic K. pneumoniae isolates from healthy adults were used as controls. RESULTS: K. pneumoniae was the second most common monomicrobial pathogen causing Gram-negative PD-related peritonitis (n = 13, 2.7%), and the most common pathogen involved in polymicrobial peritonitis (16/43, 37.2%) and associated with high catheter removal rate (7/16, 43.8%). Compared with Escherichia coli peritonitis cases, patients with monomicrobial K. pneumoniae peritonitis also had insignificantly higher incidence of sepsis/bacteremia [n = 5 (38%), p = 0.11] and a higher mortality rate [n = 3 (23%), p = 0.36]. The prevalence of K1/K2 (n = 1, 7.7%) serotypes was low, but there was a higher prevalence of serotype K20 (n = 3, 23.1%) in K. pneumoniae isolates derived from monomicrobial PD-related peritonitis compared with control groups. HV phenotype (p < 0.001) and rmpA genotype (p = 0.007) were absent in the peritonitis group. CONCLUSION: This is the first study focused on clinical and microbiological characteristics of K. pneumoniae PD-related peritonitis. K. pneumoniae was a common Gram-negative pathogen causing monomicrobial and polymicrobial PD-related peritonitis in southern Taiwan. The bacterial characteristics with low percentage of capsular serotype K1/K2, no significant HV, and absence of rmpA suggest a different pathogenesis in K. pneumoniae PD-related peritonitis compared with that in UTI and liver abscess.

Rapid identification of bacteria and Candida pathogens in peritoneal dialysis effluent from patients with peritoneal dialysis-related peritonitis by use of multilocus PCR coupled with electrospray ionization mass spectrometry.

PCR coupled with electrospray ionization mass spectrometry (PCR/ESI-MS) was compared with culture for pathogen detection in peritoneal dialysis (PD)-related peritonitis. Of 21 samples of PD effluent, PCR/ESI-MS identified microorganisms in 18 (86%) samples, including Mycobacterium tuberculosis in 1 culture-negative sample. Of 15 double-positive samples, PCR/ESI-MS and culture reached levels of agreement of 100% (15/15) and 87.5% (7/8) at the genus and species levels, respectively. PCR/ESI-MS can be used for rapid pathogen detection in PD-related peritonitis.

Bacterial characteristics and glycemic control in diabetic patients with Escherichia coli urinary tract infection.

BACKGROUND: Patients with diabetes mellitus have an increased risk of infection. The roles of bacterial characteristics and glycemic control in diabetic patients with Escherichia coli infection have not been well investigated. The aims of this study were to examine the bacterial characteristics and glycemic control in diabetic patients with E. coli infections arising in the urinary tract. METHODS: A total of 271 E. coli isolates were collected from urine and bloodstream. Phylogenetic groups, the presence of virulence genes, and antimicrobial susceptibility of E. coli isolates were determined. RESULTS: There were few differences in E. coli bacterial characteristics between 190 diabetic and 81 nondiabetic patients. In diabetic patients with urosepsis, there was a higher hemoglobin A(1C) level, and the related E. coli strains had more neuA, papG II, afa and hlyA genes, and a lower prevalence of antimicrobial resistance to cephalosporins and fluoroquinolones than those with asymptomatic bacteriuria and urinary tract infection. Multivariate logistic regression analysis revealed that increased hemoglobin A(1C) and presence of papG II and afa genes were independent factors associated with development of urosepsis in diabetic patients. CONCLUSION: This study demonstrated that more virulent E. coli isolates, especially with papG II and afa genes, and poorer glycemic control were important determinants for development of urosepsis in diabetic patients.

Clinical and microbiological characteristics of community-acquired Staphylococcus lugdunensis infections in Southern Taiwan.

Most Staphylococcus lugdunensis strains (49/59, 83%) were related to clinical infections, were susceptible to most antimicrobial agents with an overall oxacillin-resistant rate of 5% (3/58), and carried relatively great genetic diversity. Community-acquired infections (41/49, 84%) were dominant, often developed in patients with comorbidity, and had rather benign clinical courses without mortality.

Emergence of uncommon emm types of Streptococcus pyogenes among adult patients in southern Taiwan.

BACKGROUND: Streptococcus pyogenes isolated from adult patients during a 12-year period in southern Taiwan were analyzed to estimate the distribution of emm types and their correlation with disease manifestations and patient age. METHODS: Three hundred thirty-four invasive and noninvasive isolates collected from patients older than 20 years between 1997 and 2008 at National Cheng Kung University Hospital were included for emm typing. A correlation between emm type, disease manifestations, and patient ages was analyzed. RESULTS: The nine most prevalent types were emm11, emm12, emm4, emm1, Sp9458/VT8, emm81, emm106, emm13, and emm75. Formerly rare emm types, including emm11, emm81, and emm102, emerged dramatically after 2004 in southern Taiwan. Type emm11 was significantly associated with both superficial infections and cellulitis. In addition, types emm13, emm81, and emm106 were more prevalent in patients older than 50 years and significantly associated with specific invasive disease manifestation. CONCLUSION: These results suggest new emm types (emm11, emm81, and emm102) of S pyogenes were introduced into the adult population in southern Taiwan after 2004. The rarely reported emm types, including emm13, emm81, and emm106, caused invasive diseases more often in adult patients.

Association of arterial stiffness indexes, determined from digital volume pulse measurement and cardiovascular risk factors in chronic kidney disease.

BACKGROUND: Progression of atherosclerosis with increased arterial stiffness is associated with increased cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD). Compliance index (CI) derived from digital volume pulse (DVP), measuring the relationship between volume and pressure changes in fingertip, can evaluate the local arterial stiffness. The purpose of this study was to measure the stiffness of different arteries and determine the relationships of CI-DVP with clinical characteristics and renal function in CKD patients. METHODS: This cross-sectional pilot study included 186 CKD and 46 healthy subjects. Evaluation of different arterial stiffness was performed by DVP using dual-channel photoplethysmography and measured as CI (CI-DVP) and pulse wave velocity (PWV)-DVP. RESULTS: CKD patients had lower CI-DVP and higher PWV-DVP than that in the healthy group. There was a trend of stepwise decrease in CI-DVP and increase in PWV-DVP related to the advance of CKD from early to late stage. Decrease of CI-DVP was associated with the increase in number of cardiovascular risk factors. Multivariate linear regression analysis revealed that CI-DVP (B = 4.59, P < 0.01) was independently associated with estimated glomerular filtration rate (eGFR). Male gender, eGFR, and systolic blood pressure (BP) were independent determinants for CI-DVP (B = -0.25, P = 0.01; B = 0.007, P = 0.03; and B = -0.03, P < 0.0001; whole model R(2) = 0.28, P < 0.0001). CONCLUSIONS: Our data demonstrate a significant association between CI-DVP, a new surrogate marker of arterial stiffness different from PWV, and renal function and cardiovascular risk factors in CKD patients.

Comparative outcomes between hemo- and peritoneal dialysis patients with acute intracerebral hemorrhage.

BACKGROUND/AIMS: The optimal mode of dialysis for end-stage renal disease (ESRD) patients with spontaneous intracerebral hemorrhage (ICH) remains controversial. We compared the outcomes of ESRD patients who received continuous peritoneal dialysis (CPD) or extended hemodialysis (EHD) after ICH, and investigated the factors determining prognosis. METHODS: We incorporated our ICH patients with ESRD, requiring dialysis from January 2005 to December 2009. Patients were allocated to the CPD or EHD group according to the dialysis mode after ICH. We compared the 30-day mortality rate and modified Rankin Scale (mRS) of the two groups and analyzed the factors associated with mortality. RESULTS: There were 40 patients with 16 episodes in CPD and 27 episodes in EHD group, without significant differences in baseline demographic data. The 30-day mortality rate and mRS were not different between the two groups. The patients who died within 30 days had higher ICH scores (4 +/- 1 vs. 1 +/- 1, p < 0.001) and outcome scores (5 +/- 2 vs. 1 +/- 1, p < 0.001). Dialysis-related complications occurred more frequently in the PD group (p = 0.07), but were unrelated to mortality. CONCLUSION: Among ESRD patients with ICH, EHD had a similar 30-day mortality rate and 30-day mRS to those receiving CPD. The mortality was significantly related to the severity of ICH.

Separation and structure determination of nicardipine photoproducts by LC-ESI-MS.

A sample of 0.104 M nicardipine in methanol was photoirradiated with a Philips 400 W UV lamp for 3 h in a photochemical chamber. A total of four major photoproducts were found from the HPLC chromatogram. The same sample was used for taking LC-MS, while eight major photoproducts were observed and the structures elucidated by analyzing the CID patterns of their respective mass spectra. A reaction scheme of nicardipine is proposed that the photochemical reactions occur mainly via oxidation of 1,4-dihydropyridine moiety, following the stepwise photo-reduction of the m-nitro group and demethylation of the ester group at 5-position of the pyridine ring.

Identification of flurbiprofen and its photoproducts in methanol by gas chromatography-mass spectrometry.

A sample of 10 mM flurbiprofen in methanol (or ethanol) was photoirradiated with sixteen 8 W low-pressure quartz mercury lamps irradiated at 306 nm in a Panchum PR-2000 photochemical reactor. In total, four major photoproducts derived from each sample were observed from the HPLC chromatogram. The photoproducts were separated and their structures elucidated by various spectroscopic methods. Alternatively, using GC-MS, 11 major photoproducts were observed. A reaction scheme of flurbiprofen in methanol is proposed: the photochemical reaction routes occur mainly via esterification and decarboxylation, followed by oxidation with singlet oxygen to produce a ketone, alcohols and other derivatives.

Clinical characteristics and outcomes of new uremic patients with extreme azotemia in southern Taiwan.

Serum creatinine (SCr) had been considered to be an important predictor of mortality in end-stage renal disease (ESRD) patients at the start of renal replacement therapy (RRT). However, the data were limited about initially extreme azotemia (EA), exclusively defined as blood urea nitrogen (BUN) > or = 300 mg/dL, SCr > or = 30 mg/dL, or both. This retrospective study was conducted to clarify the characteristics and outcome in our EA patients. We had 1682 new ESRD patients from July 1988 to December 1996. With frequency match for age, gender, and starting RRT in the same period, 20 EA patients and 60 controls were included. Fifty percent of our EA patients had unknown etiology. The EA patients had significantly lower prevalence of underlying diabetic nephropathy, and comorbid hypertension. All the EA patients had late referral to nephrologists within 4 weeks before the initiation of RRT, and 90% of them had taken Chinese herbals. The EA group had significantly higher BUN, SCr, and iron storage as well as a higher prevalence of severe anemia, hyperkalemia, hypocalcemia, and acidemia. However, the similar prevalence of cardiomegaly and left ventricular hypertrophy as well as the similar early mortality rate and long-term survival were noted. Age over 40 years, comorbid diabetes mellitus, and hypoalbuminemia were independent predictors of poor survival. Our EA patients had different initial presentations from other uremic ones at the start of RRT. However, the short-term and long-term mortality rates were similar. The lower prevalence of underlying diabetic nephropathy and comorbid hypertension among the EA patients might contribute to their fair outcome.