Chilled Pacu (Piaractus mesopotamicus) fillets: Modeling Pseudomonas spp. and psychrotrophic bacteria growth and monitoring spoilage indicators by 1H NMR and GC-MS during storage.

This study aimed to assess the growth of Pseudomonas spp. and psychrotrophic bacteria in chilled Pacu (Piaractus mesopotamicus), a native South American fish, stored under chilling conditions (0 to 10 °C) through the use of predictive models under isothermal and non-isothermal conditions. Growth kinetic parameters, maximum growth rate (µmax, 1/h), lag time (tLag, h), and (Nmax, Log10 CFU/g) were estimated using the Baranyi and Roberts microbial growth model. Both kinetic parameters, growth rate and lag time, were significantly influenced by temperature (P < 0.05). The square root secondary model was used to describe the bacteria growth as a function of temperature. Secondary models, √µ = 0.016 (T + 10.13) and √µ =0.017 (T + 9.91) presented a linear correlation with R2 values >0.97 and were further validated under non-isothermal conditions. The model's performance was considered acceptable to predict the growth of Pseudomonas spp. and psychrotrophic bacteria in refrigerated Pacu fillets with bias and accuracy factors between 1.24 and 1.49 (fail-safe) and 1.45-1.49, respectively. Fish biomarkers and spoilage indicators were assessed during storage at 0, 4, and 10 °C. Volatile organic compounds, VOCs (1-hexanol, nonanal, octenol, and indicators 2-ethyl-1-hexanol) showed different behavior with storage time (P > 0.05). 1H NMR analysis confirmed increased enzymatic and microbial activity in Pacu fillets stored at 10 °C compared to 0 °C. The developed and validated models obtained in this study can be used as a tool for decision-making on the shelf-life and quality of refrigerated Pacu fillets stored under dynamic conditions from 0 to 10 °C.

Dapagliflozin cardiovascular effects on end-stage kidney disease (DARE-ESKD-2) trial: rationale and design.

Purpose: Sodium glucose co-transporter 2 inhibitors (SGLT2i) remarkably reduced the incidence of hospitalization for heart failure and cardiovascular death of conservatively managed chronic kidney disease. We hypothesized that adding SGLT2i to standard treatment would yield cardiovascular benefits also in end-stage kidney disease (ESKD) individuals on dialysis. Methods: The DARE-ESKD-2 Trial (NCT05685394) is an ongoing, single-center, open-label, controlled trial aimed at assessing the cardiovascular effects of dapagliflozin in ESKD on dialysis. Eligible patients are adults on renal replacement therapy for more than 3 prior to enrollment. Exclusion criteria encompass pregnancy, liver failure, and current use of a SGLT2i. After signing an informed consent form, participants are randomized 1:1 to either dapagliflozin 10mg PO plus standard treatment or standard treatment alone for 6 months. Echocardiogram, anthropometry, blood sample collection, 6-min walk test, gait speed, and Kansas City Cardiomyopathy Questionnaire (KCCQ), are performed at baseline and at study termination. Participants are contacted monthly during treatment for outcomes disclosure. The primary endpoint of our study is the between-groups differences in posttreatment changes in plasma levels of N-terminal pro-B natriuretic peptide. Secondary endpoints include the differences between groups in the changes of echocardiography measurements, cardiopulmonary tests performance, body composition. The incidence of safety endpoints will also be diligently compared between study arms. Conclusion: The DARE-ESKD-2 trial will provide unprecedented data on the cardiovascular safety and efficacy of SGLT2i in ESKD individuals on dialysis. This study will pave the grounds for improving clinical outcomes of dialysis recipients.

Simultaneous evaluation of benzotriazoles, benzothiazoles and benzenesulfonamides in water samples from the impacted urban Jacarepaguá Lagoon System (Rio de Janeiro, Brazil) by liquid chromatography coupled to electrospray tandem mass spectrometry.

Benzotriazoles, benzothiazoles, and benzenesulfonamides are emerging pollutants stable in aquatic media emitted by anthropogenic sources. Selected compounds of these classes were evaluated in the impacted urban Jacarepaguá Lagoon System (JLS) located in a tropical coastal region of Rio de Janeiro City, Brazil that has experienced a rapid expansion of urban occupation and environmental degradation in recent decades, and it represents a pioneering study of these compounds carried out in Brazilian areas. A method of solid phase extraction followed by ultra-performance liquid chromatography coupled to electrospray tandem mass-spectrometry was implemented to evaluate water samples collected in different water bodies (rivers, lagoons, and channels) of the JLS from March 2017 to May 2018. Limits of quantification (LOQs) ≤ 10.0 ng L-1, method linearity up to 1000 µg L-1, and recoveries between 62 and 121 % at three different levels were obtained. Individual concentrations varied from < LOQ to 5260 ng L-1 (benzotriazole, in May 2018) which also predominated in all river samples. 2-mercaptobenzothiazole predominated in samples taken in lagoons and channels in March 2017, and 2-aminobenzothiazole was never detected. River samples showed total concentrations up to 30 times larger in all sampling campaigns, except March 2017 when the sample taken at Tijuca Lagoon showed the largest total concentration of the compounds studied due to the largest concentration of 2-mercaptobenzothiazole (2505 ng L-1) found in this study. Principal component analysis (PCA) using only composition data was unable to distinguish samples from rivers, and lagoons and channels, but a PCA combining composition data and environmental parameters (pH, Eh, dissolved O2 concentration, temperature, salinity, and conductivity) discriminated the samples according to two groups: rivers and lagoons and channels. The Joá Channel flows directly to the open sea and our data allowed a (preliminary) estimation of the total mass flows of the studied compounds to the open sea, which would vary between 1702 g day-1 (March 2017) to 106 g day-1 (May 2018) and allowed a preliminary estimative based on the geometric mean of input of 87.9 kg year-1, indicating the importance of the drainage area to the contamination of the coastal area, and consequently to ocean pollution.

Rationale and design of the Brazilian diabetes study: a prospective cohort of type 2 diabetes.

BACKGROUND: Optimal control of traditional risk factors only partially attenuates the exceeding cardiovascular mortality of individuals with diabetes. Employment of machine learning (ML) techniques aimed at the identification of novel features of risk prediction is a compelling target to tackle residual cardiovascular risk. The objective of this study is to identify clinical phenotypes of T2D which are more prone to developing cardiovascular disease. METHODS: The Brazilian Diabetes Study is a single-center, ongoing, prospective registry of T2D individuals. Eligible patients are 30 years old or older, with a confirmed T2D diagnosis. After an initial visit for the signature of the informed consent form and medical history registration, all volunteers undergo biochemical analysis, echocardiography, carotid ultrasound, ophthalmologist visit, dual x-ray absorptiometry, coronary artery calcium score, polyneuropathy assessment, advanced glycation end-products reader, and ambulatory blood pressure monitoring. A 5-year follow-up will be conducted by yearly phone interviews for endpoints disclosure. The primary endpoint is the difference between ML-based clinical phenotypes in the incidence of a composite of death, myocardial infarction, revascularization, and stroke. Since June/2016, 1030 patients (mean age: 57 years, diabetes duration of 9.7 years, 58% male) were enrolled in our study. The mean follow-up time was 3.7 years in October/2021. CONCLUSION: The BDS will be the first large population-based cohort dedicated to the identification of clinical phenotypes of T2D at higher risk of cardiovascular events. Data derived from this study will provide valuable information on risk estimation and prevention of cardiovascular and other diabetes-related events. CLINICALTRIALS.GOV IDENTIFIER: NCT04949152.

Lower bone mass is associated with subclinical atherosclerosis, endothelial dysfunction and carotid thickness in the very elderly.

BACKGROUND AND AIMS: Osteoporosis and coronary heart disease (CHD) are very common conditions among elderly people, and both represent a public health concern due to their prognostic consequences. Osteoporosis and CHD share many risk factors and pathophysiological mechanisms, such as calcification pathways. Clinical evidence associates lower bone mass with cardiovascular diseases and endothelial dysfunction. Hence, this study aims to investigate whether bone mass density is associated with subclinical atherosclerosis and/or endothelial dysfunction in the very elderly. METHODS: We performed a cross-sectional study of cohort enrolled individuals, ages 80 years or older (n = 208), who had never manifested cardiovascular diseases. Medical evaluation, blood tests, flow-mediated dilation (FMD), carotid intimal-media thickness (IMT), Dual Energy X-ray Absorptiometry (DEXA) and Coronary Calcium Score (CCS) were obtained. Odds Ratio (OR) was calculated by multivariate logistic regression models using CCS, FMD and IMT categories. Adjustments for covariates were done. RESULTS: Overall bone mass was independently and inversely associated with CCS categories [OR:1.68(1.16-8.85); p = 0.024] and IMT categories [OR:2.97(1.11-7.90); p = 0.030]. Conversely, overall bone mass was independent and directly associated with FMD categories [OR:2.73(1.36-70.39); p = 0.023]. CONCLUSIONS: This study indicates that overall bone mass is independently and inversely associated with subclinical atherosclerosis, endothelial dysfunction and thickness of carotid in the very elderly.

Predictive Factors of One-Year Mortality in a Cohort of Patients Undergoing Urgent-Start Hemodialysis.

BACKGROUND: Chronic kidney disease (CKD) affects 10-15% of adult population worldwide. Incident patients on hemodialysis, mainly those on urgent-start dialysis at the emergency room, have a high mortality risk, which may reflect the absence of nephrology care. A lack of data exists regarding the influence of baseline factors on the mortality of these patients. The aim of this study was to evaluate the clinical and laboratory characteristics of this population and identify risk factors that contribute to their mortality. PATIENTS AND METHODS: We studied 424 patients who were admitted to our service between 01/2006 and 12/2012 and were followed for 1 year. We analyzed vascular access, risk factors linked to cardiovascular disease (CVD) and mineral and bone disease associated with CKD (CKD-MBD), and clinical events that occurred during the follow-up period. Factors that influenced patient survival were evaluated by Cox regression analysis. RESULTS: The patient mean age was 50 ± 18 years, and 58.7% of them were male. Hypertension was the main cause of primary CKD (31.8%). Major risk factors were smoking (19.6%), dyslipidemia (48.8%), and CVD (41%). Upon admission, most patients had no vascular access for hemodialysis (89.4%). Biochemical results showed that most patients were anemic with high C-reactive protein levels, hypocalcemia, hyperphosphatemia, elevated parathyroid hormone and decreased 25-hydroxy vitamin D. At the end of one year, 60 patients died (14.1%). These patients were significantly older, had a lower percentage of arteriovenous fistula in one year, and low levels of 25-hydroxy vitamin D. CONCLUSIONS: The combined evaluation of clinical and biochemical parameters and risk factors revealed that the mortality in urgent-start dialysis is associated with older age and low levels of vitamin D deficiency. A lack of a permanent hemodialysis access after one year was also a risk factor for mortality in this population.

Peritoneal delivery of sodium pyrophosphate blocks the progression of pre-existing vascular calcification in uremic apolipoprotein-E knockout mice.

Chronic kidney disease (CKD) is generally associated with disturbances of mineral and bone metabolism. They contribute to the development of vascular calcification (VC), a strong, independent predictor of cardiovascular risk. Pyrophosphate (PPi), an endogenous inhibitor of hydroxyapatite formation, has been shown to slow the progression of VC in uremic animals. Since in patients with CKD treatment is usually initiated for already existing calcifications, we aimed to compare the efficacy of PPi therapy with that of the phosphate binder sevelamer, using a uremic apolipoprotein-E knockout mouse model with advanced VCs. After CKD creation or sham surgery, 12-week-old female mice were randomized to one sham group and four CKD groups (n = 18-19/group). Treatment was initiated 8 weeks after left nephrectomy allowing prior VC development. Uremic groups received either intraperitoneal PPi (high dose, 1.65 mg/kg or low dose, 0.33 mg/kg per day), oral sevelamer (3 % in diet), or placebo treatment for 8 weeks. Both intima and media calcifications worsened with time in placebo-treated CKD mice, based on both quantitative image analysis and biochemical measurements. Progression of calcification between 8 and 16 weeks was entirely halted by PPi treatment, as it was by sevelamer treatment. PPi did not induce consistent bone histomorphometry changes. Finally, the beneficial vascular action of PPi probably involved mechanisms different from that of sevelamer. Further studies are needed to gain more precise insight into underlying mechanisms and to see whether PPi administration may also be useful in patients with CKD and VC.

Is urinary density an adequate predictor of urinary osmolality?

BACKGROUND: Urinary density (UD) has been routinely used for decades as a surrogate marker for urine osmolality (Uosm). We asked if UD can accurately estimate Uosm both in healthy subjects and in different clinical scenarios of kidney disease. METHODS: UD was assessed by refractometry. Uosm was measured by freezing point depression in spot urines obtained from healthy volunteers (N = 97) and in 319 inpatients with acute kidney injury (N = 95), primary glomerulophaties (N = 118) or chronic kidney disease (N = 106). RESULTS: UD and Uosm correlated in all groups (p < 0.05). However, a wide range of Uosm values was associated with each UD value. When UD was ≤ 1.010, 28.4% of samples had Uosm above 350 mOsm/kg. Conversely, in 61.6% of samples with UD above 1.020, Uosm was below 600 mOsm/kg. As expected, Uosm exhibited a strong relationship with serum creatinine (Screat), whereas a much weaker correlation was found between UD and Screat. CONCLUSION: We found that UD is not a substitute for Uosm. Although UD was significantly correlated with Uosm, the wide dispersion makes it impossible to use UD as a dependable clinical estimate of Uosm. Evaluation of the renal concentrating ability should be based on direct determination of Uosm.

Hemodynamic behavior during hemodialysis: effects of dialysate concentrations of bicarbonate and potassium.

BACKGROUND/AIMS: Ultrafiltration that occurs during hemodialysis (HD) promotes profound alterations in a relatively short period of time. The dialysate content of bicarbonate (DBic) and potassium (DK) may have impact over intradialytic hemodynamics, which goes beyond ultrafiltration, and its impact was evaluated in a prospective cohort. METHODS: 30 patients under HD were submitted to hemodynamic assessment (HA) at the beginning and at the end of HD sessions, through a non-invasive method. Serum minus dialysate potassium concentration was expressed as K-Gap. Cardiac index (CI) and peripheral arterial resistance (PAR) variation (post-HD minus pre-HD) were expressed as ΔCI and ΔPAR. Dialysate content of sodium and calcium were expressed as DNa and DCa, respectively. RESULTS: Mean DNa, DK and DBic were, respectively, 136.4 ± 1.1, 2.1 ± 0.6 and 38.2 ± 2.1 mEq/L. In 15 patients, DCa was >1.5 mmol/L and in the other 15 patients ≤ 1.5 mmol/L. The K-Gap ranged from 1.4 to 5.1 mEq/l (median 3.0 mEq/L). There was a reduction in post-HD CI and systolic blood pressure (ΔCI = -0.72l/min/m(2) and -11.3±15.1mmHg, respectively, p<0.001 for both). Conversely, PAR increased (ΔPAR = 272dyn.s/cm(5), p<0.001). Lower post-HD CI was was associated to higher DBic (p=0.0013) and lower K-Gap (p=0.026). In multivariate analysis, ΔCI was dependent on DBic and K-Gap, whereas ΔPAR was dependent on dialysate calcium during HD. CONCLUSION: We confirmed that Na and Ca dialysate content exerts and important role on hemodynamic during HD. In addition, our findings pointed out that higher dialysate concentrations of bicarbonate and potassium promote lower cardiac performance at the end of hemodialysis session.

Serum sclerostin is an independent predictor of mortality in hemodialysis patients.

BACKGROUND: Sclerostin (Scl) has recently emerged as a novel marker of bone remodeling and vascular calcification. However, whether high circulating Scl is also a risk factor for death is not well established. The purpose of this study was to test whether serum Scl would be associated with mortality. METHODS: we measured serum Scl in a hemodialysis patients' cohort, which was followed during a ten-year period. Competing risk regression models were applied, as during the follow-up, patients were exposed to both events kidney transplant and death. RESULTS: Ninety-one patients aged 42.3±18.8 years (55% of male gender, 15% of diabetes) were included. During the follow-up, 32 patients underwent kidney transplant and 26 patients died. Non-survivals presented higher FGF23, higher Scl and lower creatinine. There was an association between all-cause mortality and higher Scl (HR=2.2), higher age (HR=1.04) and presence of diabetes (HR=2.27), by competing risk analyses. Even including potential markers of mortality, as creatinine, FGF 23, and gender, Scl, age and diabetes remained significantly related to higher mortality. CONCLUSION: Serum Scl is an independent predictor of mortality in dialysis patients. However, whether clinical interventions to modulate Scl would be able to improve these patients survival needs to be determined.

Effects of pyrophosphate delivery in a peritoneal dialysis solution on bone tissue of apolipoprotein-E knockout mice with chronic kidney disease.

Vascular calcification (VC) is a risk factor for cardiovascular mortality in the setting of chronic kidney disease (CKD). Pyrophosphate (PPi), an endogenous molecule that inhibits hydroxyapatite crystal formation, has been shown to prevent the development of VC in animal models of CKD. However, the possibility of harmful effects of exogenous administration of PPi on bone requires further investigation. To this end, we examined by histomorphometry the bone of CKD mice after intraperitoneal PPi administration. After CKD creation or sham surgery, 10-week-old female apolipoprotein-E knockout (apoE(-/-)) mice were randomized to one non-CKD group or 4 CKD groups (n = 10-35/group) treated with placebo or three distinct doses of PPi, and fed with standard diet. Eight weeks later, the animals were killed. Serum and femurs were sampled. Femurs were processed for bone histomorphometry. Placebo-treated CKD mice had significantly higher values of osteoid volume, osteoid surface and bone formation rate than sham-placebo mice with normal renal function. Slightly higher osteoid values were observed in CKD mice in response to very low PPi dose (OV/BV, O.Th and ObS/BS) and, for one parameter measured, to high PPi dose (O.Th), compared to placebo-treated CKD mice. Treatment with PPi did not modify any other structural parameters. Mineral apposition rates, and other parameters of bone formation and resorption were not significantly different among the treated animal groups or control CKD placebo group. In conclusion, PPi does not appear to be deleterious to bone tissue in apoE(-/-) mice with CKD, although a possible stimulatory PPi effect on osteoid formation may be worth further investigation.

Disturbances of Wnt/ß-catenin pathway and energy metabolism in early CKD: effect of phosphate binders.

BACKGROUND: Mineral bone disorder (MBD) is an early complication of chronic kidney disease (CKD), with complex interactions in the bone-kidney-energy axis. These events lead to impaired bone remodelling, which in turn is associated with cardiovascular disease. Recently, we reported on a positive effect of phosphate binder treatment on bone remodelling markers and a reduction in serum FGF-23 levels in predialysis-CKD patients. The goal of the present study of this trial was to examine the effects of phosphate binders on energy-regulating hormones and Wnt pathway. METHODS: In this present post hoc analysis of the above randomized, open-label, 8-week trial, which compared the effects of increasing doses of sevelamer-HCl or calcium acetate on various CKD-MBD parameters in 40 normophosphatemic CKD Stage 3-4 patients, we measured serum sclerostin, Dickkopf-1, leptin, adiponectin and serotonin concentrations. RESULTS: Serum sclerostin, Dickkopf-1 and leptin were elevated at baseline despite normal calcium, phosphorus levels and daily urinary phosphorus excretion. There were significant and positive correlations between sclerostin and FGF-23, as well between leptin and Dickkopf-1. Treatment with both phosphate binders led to a significant decrease in phosphate overload. However, sevelamer-HCl, but not with calcium acetate, led to a significant decrease in serum FGF-23, sclerostin and leptin, and to a significant increase in bone alkaline phosphatase levels. CONCLUSIONS: Early stages of CKD are associated with an impairment of the Wnt pathway, as reflected by elevated sclerostin, and a dysregulation of energy-regulating hormones. Many of these disturbances can be ameliorated by phosphate binder treatment, more with sevelamer-HCl than with calcium acetate.

Fibroblast growth factor 23 in hemodialysis patients: effects of phosphate binder, calcitriol and calcium concentration in the dialysate.

BACKGROUND: Fibroblast growth factor 23 (FGF23) concentrations increase early in chronic kidney disease (CKD), and the influence of current CKD-mineral and bone disorder (MBD) therapies on serum FGF23 levels is still under investigation. METHODS: In this post-hoc analysis of a randomized clinical trial, phosphate binders and calcitriol were washed out of 72 hemodialysis patients who were then submitted to bone biopsy, coronary tomography and biochemical measures, including FGF23. They were randomized to receive sevelamer or calcium acetate for 1 year and the prescription of calcitriol and the calcium concentration in the dialysate were adjusted according to serum calcium, phosphate and PTH and bone biopsy diagnosis. RESULTS: At baseline, bone biopsy showed that 58.3% had low-turnover bone disease, whereas 38.9% had high-turnover bone disease, with no significant differences between them with regard to FGF23. Median baseline FGF23 serum levels were elevated and correlated positively with serum phosphate. After 1 year, serum FGF23 decreased significantly. Repeated measures ANOVA analysis showed that the use of a 3.5-mEq/l calcium concentration in the dialysate, as well as the administration of calcitriol and a calcium-based phosphate binder were associated with higher final serum FGF23 levels. CONCLUSIONS: Taken together, our results confirm that the current CKD-MBD therapies have an effect on serum levels of FGF23. Since FGF23 is emerging as a potential treatment target, our findings should be taken into account in the decision on how to manage CKD-MBD therapy.

Early control of PTH and FGF23 in normophosphatemic CKD patients: a new target in CKD-MBD therapy?

BACKGROUND AND OBJECTIVES: Levels of parathyroid hormone (PTH) and the phosphaturic hormone FGF23, a fibroblast growth factor (FGF) family member, increase early in chronic kidney disease (CKD) before the occurrence of hyperphosphatemia. This short-term 6-wk dose titration study evaluated the effect of two phosphate binders on PTH and FGF23 levels in patients with CKD stages 3 to 4. DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS: Patients were randomized to receive over a 6-wk period either calcium acetate (n = 19) or sevelamer hydrochloride (n = 21). RESULTS: At baseline, patients presented with elevated fractional excretion of phosphate, serum PTH, and FGF23. During treatment with both phosphate binders there was a progressive decline in serum PTH and urinary phosphate, but no change in serum calcium or serum phosphate. Significant changes were observed for FGF23 only in sevelamer-treated patients. CONCLUSIONS: This study confirms the positive effects of early prescription of phosphate binders on PTH control. Prospective and long-term studies are necessary to confirm the effects of sevelamer on serum FGF23 and the benefits of this decrease on outcomes.