Urine Collection Research Articles

The effect of supplementary selenium source on apparent and true absorption, retention, performance, and selenium status in lactating Holstein cows

Selenium is an essential trace mineral for dairy cattle and can be provided in the diet in various forms that may differ in bioavailability. The objective of this study was to determine how source of Se affects animal performance, Se status, retention, and apparent and true absorption. Multiparous Holstein cows (n = 24; 597 ± 49 kg body weight) were blocked by days in milk (DIM; 161 ± 18) and randomly assigned to receive 0.3 mg Se/kg of dry matter (100% of NASEM requirements) of either organic Se (ORG; selenized yeast) or inorganic Se (INO; sodium selenite). The Se premix was top-dressed on a common total mixed ration fed daily and mixed into the top 15 cm directly before feeding. Following an 11-wk adaptation period, cows received simultaneous infusions of an intraruminal isotope dose of 77Se in the same chemical form as the premix, and an intravenous dose of 82Se in an inorganic form. Infusions were followed by a 4-d period of blood and rumen fluid sampling, and total collection of feces, urine, and milk. Daily dry matter intake (23 ± 0.6 kg), milk yield (35 ± 1.2 kg), and serum Se (0.11 ± 0.003 µg/g) were not different between treatments during the adaptation period, but milk Se concentrations were greater for ORG compared with INO. Serum 77Se maximum concentration (Cmax) and area under the curve (AUC) were not different between treatments for 72 h following infusion, but rumen fluid 77Se AUC was higher for ORG than INO. Apparent absorption (64 ± 1.4%), and retention (44 ± 1.5%) of the 77Se dose did not differ between treatments. True absorption was calculated using 82Se enrichment in serum and feces and was determined to be 69 ± 1.3% and did not differ between treatments. Fecal excretion of the 77Se dose was not different between treatments (36 ± 1.4%), but ORG had lower urinary excretion and higher milk excretion compared with INO. These results indicate that organic Se resulted in greater Se concentration of milk and lower urinary Se excretion into the environment, but absorption, Se status, and performance of the cow were not affected by Se source at this supplementation level.

A multicomponent LC-MS/MS method for drugs of abuse testing using volumetric DBS and a clinical evaluation by comparison with urine

BackgroundDrug testing commonly use urine as a specimen and immunoassays for screening. The need for supervised urine collection has led to an interest in alternative specimens and a need for using mass spectrometry methods already for screening. In addition, mass spectrometry methods allow for broad multipanel screening which of great value because of the increased number of substances that needs to be covered has increased over time. One alternative specimen of interest for drugs of abuse testing is dried blood spots (DBS) and this work aimed at developing multipanel screening methods based on selected reaction monitoring liquid chromatography - mass spectrometry for both urine and dried finger blood as specimens. Materials and MethodsThe urine method comprised 37 analytes and utilised salted out liquid/liquid extraction in 96-well format, respectively, and the blood method comprised 35 analytes, a 10 µL volumetric DBS device and a two-step solvent extraction procedure. In both cases stable isotope labelled internal standards were used for almost all analytes. ResultsThe methods were validated according to forensic standard. The lowest reporting limits were generally set at 100 ng/mL for urine and 1 ng/mL for blood and the accuracy and imprecision were within limits of 15 and 20%. The methods were applied in a clinical study on patients receiving methadone maintenance treatment for opioid dependence. Methadone was detected in all urine and DBS samples, for urine sometimes below the commonly applied screening cutoff limit of 300 ng/mL. In 20 out of 99 cases no other drug was detected in any specimen. The most commonly other detected substances were pregabalin, amphetamine, alprazolam, zopiclone and THCCOOH. Findings in urine and DBS generally agreed well but more positives were detected in DBS. ConclusionMultipanel methods using liquid chromatography – mass spectrometry suitable for clinical drug screening were successfully developed for urine and blood collected by finger-pricking and stored as DBS.

Review of clinical guidelines for the diagnosis, treatment and prevention of urinary tract infection in children

Urinary tract infection (UTI) is one of the most common bacterial diseases in childhood. The difficulty of diagnosis and timely administration of adequate therapy is associated with differences in the clinical course of the disease in different age groups, localization of the infectious process (upper and lower urinary tract), methods of urine collection and interpretation of the obtained results. The possibility and amount of instrumental diagnostics also varies depending on the region and the specifics of the organization of the healthcare system. The problem of increasing resistance of microorganisms is aggravated by the often-excessive prescription of antimicrobial chemotherapy drugs, which leads to a narrowing of the range of available drugs and the possibility of their use in appropriate age groups. All of the above explains the lack of uniform approaches and the existence of many international and local clinical recommendations on the problem of UTI. This review highlights the features of urine collection in non- and toilet-trained children and also discusses the assumptions and limitations of using screening methods for urinalysis. Indications for urine culture and differences in the interpretation of results depending on the method of obtaining a urine sample are presented, as well as data on modern instrumental diagnostic methods and strategies for their use in practice. A comparative description of current international clinical recommendations for the diagnosis, treatment and prevention of UTIs in children is provided.

47 Inclusion of black soldier fly (Hermetia illucens) larvae frass as an alternative protein source in the diet of Florida native yearling ewes.

Abstract The objective of the study was to evaluate the effects of partially replacing soybean meal (SBM) with black soldier fly larvae frass (BSFL) on nutrient digestibility, growth performance, and blood profile of ewes consuming diets with approximately 10% SBM on a DM basis. Six yearling Florida native ewes, averaging (mean ± SD) 44 ± 3 kg BW were enrolled in a replicated 3 × 3 Latin square design with 3 experimental periods of 21 d each (14 d adaptation + 4 d samples collection + 3 d washout). First 14 d of each period, ewes were housed in 7.4 × 1.8 m individual pens with rubber mats, one automatic waterer and two plastic feeders. During collection, ewes were moved to 1.4 × 0.7 m metabolic crates equipped with an individual waterer and feeder and two trays for the collection of feces and urine. Animals were fed TMR ad libitum twice daily at 0730 and 1530 h consisting of different levels of SBM replacement with BSFL, as follows: no replacement (CON), partial replacement of SBM with 25% BSFL (BSFL25) and 50% BSFL (BSFL50) on a DM basis. Data on DM and nutrient intake, excretion, and apparent digestibility, and also plasma concentrations of glucose and blood urea nitrogen (BUN), and urine concentrations of allantoin, urine blood nitrogen, and uric acid, were collected. Data were analyzed with SAS 9.4 evaluating orthogonal polynomial contrasts to determine linear and quadratic effects of SBM replacement with BSFL for each response variable. The intakes of DM, NDF, ADF, EE, and starch were greater for BSFL25 compared with control (Quadratic effect; P < 0.01) while no differences were observed between BSFL25 and BSFL50. Similarly apparent digestibilities of DM, NDF, ADF and starch was less for BSFL25 than CON (Quadratic effect; P ≤ 0.01). Intake of CP linearly increased (P < 0.01) with BSFL, while apparent digestibility of CP linearly decreased and that of EE increased, with inclusion of BSFL. There was a quadratic effect of BSFL on total feces excretion (P < 0.01) and water consumption (P < 0.01) being greater in BSFL25 compared with CON. Urine BUN (P < 0.01) and urine nitrogen (P < 0.01) linearly increased with BSFL inclusion. Results indicate that partial replacement of SBM with BSFL in the diet of yearling Florida native ewes may quadratically increase feed intake and decrease nutrient apparent digestibility. Further research is needed to explore the long-term implications of incorporating BSFL into animal diets, considering their impact on overall growth and performance.

Differences in Fluid, Electrolyte, and Energy Balance in C57BL/6J Mice (Mus musculus) in Metabolic Caging at Thermoneutral or Standard Room Temperatures.

The Guide for the Care and Use of Laboratory Animals recommends mice be pair or group housed and provided with nesting materials. These provisions support social interactions and are also critical for thermoregulatory behaviors such as huddling and burrowing. However, studies of fluid and electrolyte balance and digestive function may involve use of metabolic caging (MC) systems in which mice are housed individually on wire-mesh floors that permit quantitative collection of urine and feces. MC housing prevents mice from performing their typical huddling and burrowing behaviors. Housing in MC can cause weight loss and behavioral changes in rodents. Here, we tested the hypothesis that MC housing of mice at standard room temperature (SRT, 22 to 23 °C) exposes them to cold stress, which causes metabolic changes in the mice as compared with standard housing. We hypothesized that performing MC studies at a thermoneutral temperature (TNT, 30 °C) would minimize these changes. Fluid, electrolyte, and energy balance and body composition were assessed in male and female C57BL/6J mice housed at SRT or TNT in MC, static microisolation cages, or a multiplexed metabolic phenotyping system designed to mimic static microisolation cages (Promethion, Sable Systems International). In brief, as compared with MC housing at SRT, MC housing at TNT was associated with lower food intake and energy expenditure, absence of weight loss, and lower urine and fecal corticosterone levels. These results indicate that housing in MC at SRT causes cold stress that can be mitigated if MC studies are performed at TNT.

Real-World Effectiveness of Preventive Pharmacological Therapy in Patients With Urolithiasis: A Retrospective Cohort Study

Data supporting the efficacy of preventive pharmacological therapy (PPT) to reduce urolithiasis recurrence are based on clinical trials with composite outcomes that incorporate imaging findings and have uncertain clinical significance. This study evaluated whether the use of PPT leads to fewer symptomatic stone events. Retrospective cohort study. Medicare enrollees with urolithiasis who completed 24-hour urine collections that revealed hypercalciuria, hypocitraturia, low urine pH, or hyperuricosuria. PPT (thiazide diuretics for hypercalciuria, alkali for hypocitraturia or low urine pH, or uric acid lowering drugs for hyperuricosuria) categorized as (1) adherent to guideline-concordant PPT, (2) nonadherent to guideline-concordant PPT, or (3) untreated. Symptomatic stone event occurrence (emergency department [ED] visit or hospitalization for urolithiasis or stone-directed surgery). Cox proportional hazards regression. Among 13,942 patients, 31.0% were prescribed PPT. Compared with no treatment, concordant/adherent PPT use was associated with a significantly lower hazard of symptomatic stone events for patients with hypercalciuria (HR, 0.736 [95% CI, 0.593-0.915]) and low urine pH (HR, 0.804 [95% CI, 0.650-0.996]) but not for patients with hypocitraturia or hyperuricosuria. These associations were largely driven by significantly lower rates of ED visits after initiating PPT among the concordant/adherent group versus untreated patients. Patients with hypercalciuria had adjusted 2-year predicted probabilities of a visit of 3.8% [95% CI, 2.5%-5.2%%] and 6.9% [95% CI, 6.0%-7.7%] for the concordant/adherent PPT and no-treatment groups, respectively. Among patients with low urine pH, these probabilities were 4.3% (95% CI, 2.9%-5.7%) and 7.3% (95% CI, 6.5%-8.0%) for the concordant/adherent PPT and no-treatment groups, respectively. Potential bias from the possibility that patients prescribed PPT had more severe disease than untreated patients. Patients with urolithiasis and hypercalciuria who were adherent to treatment with thiazide diuretics as well as those with low urine pH adherent to prescribed alkali therapy had fewer symptomatic stone events than untreated patients. Despite multiple clinical trials demonstrating the efficacy of thiazide diuretics and alkali for secondary prevention of kidney stones, they are infrequently prescribed due in part to a lack of data about their effectiveness in real-world settings. We analyzed medical claims from older adults with kidney stones for whom urine chemistry data were available. We found that patients who took prescribed thiazide diuretics for elevated urine calcium levels or alkali for low urinary pH were less likely to experience symptomatic stone recurrences than untreated patients. This benefit was expressed as lower rates of emergency department visits after initiating therapy. Our findings should inform the prescription of and adherence to treatment with thiazide diuretics and alkali for the prevention of recurrent kidney stones.

Relationships between gastrointestinal permeability, heat stress, and milk production in lactating dairy cows

Heat stress (HS) is a global issue that decreases farm profits and compromises animal welfare. To distinguish between the direct and indirect effects of HS, 16 multiparous Holstein cows approximately 100 d in milk were assigned to one of 2 treatments: pair fed to match HS cow intake, housed in thermoneutral conditions (PFTN, n = 8) or cyclical HS (n = 8). All cows were subjected to 2 experimental periods. P1 consisted of a 4 d thermoneutral period with ad libitum intake. During P2, the HS cows were housed in cyclical HS conditions with a temperature humidity index (THI) ranging from 76 to 80 and the PFTN cows were exposed to a constant THI of 64 for 4 d. DMI of the PFTN cow was intake matched to the HS cows. Milk yield, milk composition, rectal temperature, and respiration rate were recorded twice daily, blood was collected daily via a jugular catheter, and cows were fed twice daily. On d 3 of each period, Cr-EDTA and sucralose were orally administered and recovered via 24 h total urine collection to assess gastrointestinal permeability (GIP). All data were analyzed using the GLIMMIX procedure in SAS. The daily data collected in P1 was averaged and used as a covariate if deemed significant in the model. HS decreased voluntary intake by 35% and increased rectal temperature and respiration rate (38.4 vs 39.4°C and 40 vs 71 respirations/min, respectively). HS reduced dry matter intake (DMI) by 35% which accounted for 66% of the decrease in milk yield. The yield, and not concentration, of milk protein, fat, and other solids were lower in the HS cows on d 4 of P2. Milk urea nitrogen (MUN) was higher and plasma urea nitrogen (PUN) tended to be higher on d 3 and d 4 of HS. Glucose was 7% lower in the HS cows and insulin was 71% higher in the HS cows than the PFTN cows on d 4 of P2. No difference in lipopolysaccharide binding protein (LBP) was observed. HS cows produced 7 L/d more urine than PFTN cows. No differences were detected in the urine concentration or percentage of the oral dose recovered for Cr-EDTA or sucralose. In conclusion, HS was responsible for 34% of the reduction of milk yield. The elevated MUN and the tendency for elevated PUN indicate a whole-body shift in nitrogen metabolism. No differences in GIP or LBP were observed. These results indicate that, under conditions of this experiment, activation of the immune system by gut derived lipopolysaccharide was not responsible for the decreased milk yield observed during HS.

Snížená hladina magnezia v moči po ileokolické resekci u pacientů s Crohnovou chorobou

Summary: Introduction: Urinary excretion of magnesium is an important preventive factor against nephrolithiasis by inhibiting several key processes in its pathogenesis. Patients with Crohn’s disease (CD) have an approximately 2-fold higher risk of lithiasis, especially those after ileocolic (IC) resection. The aim is to determine the magnesuria level in these patients and compare it with patients with CD and IC involvement without resection and then both groups with healthy controls. The secondary objective was to assess calciuria and other modifying factors. Methods: CD patients aged 18 years or older with IC resection (group 1) and terminal ileal involvement without resection (group 2) were enrolled in the study, with subjects without known bowel disease as controls (group 3). Exclusion criteria were citrate therapy, severe renal insufficiency (GFR < 30 ml/ min/ 1.73 m2), more than two bowel resections, ileostomy, colectomy, short bowel syndrome, acute urinary tract infection and evidence of CD relapse. Anamnestic data were collected by questionnaire, blood and fresh urine samples were collected, renal and gallbladder ultrasound was performed for the presence of lithiasis, and patients underwent 24-hour urine collection to determine oxaluria, citraturia, magnesuria and calciuria. Results: 107 subjects were included in the study, including 34 patients with IC resection, 42 with CD without resection and 31 healthy controls. 43% were women, mean age was 38 ± 11.5 years. There was a significant difference in magnesuria values between the resection and non-resection group (median 2.28 vs. 3.97 mmol/ l; P = 0.047) and especially between the resection group and healthy controls (median 2.28 vs. 4.31 mmol/ l; P = 0.0003). The group without resection vs. healthy controls did not reach a significant difference (median 3.97 vs. 4.31 mmol/ l; P = 0.455). Calciuria values did not differ significantly between groups (median 3.75 vs. 4.6 vs. 4.3 mmol/ l; P = 0.293). Conclusion: Magnesuria values of CD patients after IC resection were significantly lower compared to the group of CD patients with IC involvement without resection and healthy controls. The group without resection achieved results comparable to controls. Calciuria values were not significantly different between groups in our study. We hypothesize that patients with CD after IC resection at higher risk of urolithiasis might benefit from Mg supplementation to prevent concretion formation. However, confirmation of this thesis will require verification by further research. Key words: inflammatory bowel disease – Crohn’s disease – urolithiasis – magnesium – calcium oxalate

In vivo and in vitro metabolite profiling of nirmatrelvir using LC-Q-ToF-MS/MS along with the in silico approaches for prediction of metabolites and their toxicity.

Nirmatrelvir (NRV), a 3C-like protease or Mpro inhibitor of SARS-CoV-2, is used for the treatment of COVID-19 in adult and paediatric patients. The present study was accomplished to investigate the comprehensive metabolic fate of NRV using in vitro and in vivo models. The in vitro models used for the study were microsomes (human liver microsomes, rat liver microsomes, mouse liver microsomes) and S9 fractions (human liver S9 fractions and rat liver S9 fractions) with the appropriate cofactors, whereas Sprague-Dawley rats were used as the in vivo models. Nirmatrelvir was administered orally to Sprague-Dawley rats, which was followed by the collection of urine, faeces and blood at pre-determined time intervals. Protein precipitation was used as the sample preparation method for all the samples. The samples were then analysed by liquid chromatography-quadrupole time-of-flight tandem mass spectrometry (LC-Q-ToF-MS/MS) using an Acquity BEH C18 column with 0.1% formic acid and acetonitrile as the mobile phase. Four metabolites were found to be novel, which were formed via amide hydrolysis, oxidation and hydroxylation. Furthermore, an in silico analysis was performed using Meteor Nexus software to predict the probable metabolic changes of NRV. The toxicity and mutagenicity of NRV and its metabolites were also determined using DEREK Nexus and SARAH Nexus.

Screening for contamination levels of select organic environmental chemicals in medical supplies used for human specimen collection

Trace-level analysis of environmental chemicals in human specimens can be compromised by contamination introduced during sample collection and storage. Sampling devices and tools can be a source of contamination by plasticizers, additives and antimicrobials, which warrants the need for pre-screening of these products prior to use. In this study, we determined leaching of 121 environmental chemicals in 10% and 100% methanol from 24 types of human specimen collection and storage devices. Cryovials, serum tubes, cups, syringes, transfer pipettes, and gloves -commonly used for the collection of blood, urine, breast milk and stools - were screened for the presence of plasticizers, environmental phenols, and pesticides. Measurable levels of mono-ethyl phthalate (mEP) and triethyl phosphate (TEP) were leached from vials, plastic storage bags, gloves, and diapers, and parabens were leached from collection bottles, at amounts exceeding 100 ng/device. The amount leached from the devices varied depending on the lot numbers of the same product type. Storage time and temperature were found to influence the leaching rate of chemicals, with increased levels observed following prolonged storage and at high temperatures. The study underscores the importance of pre-screening for contamination in devices used for collection and storage of human specimens for biomonitoring studies.

Can sodium and potassium measured in timed voids be used as reference instruments for validating self-report instruments? Results from a urine calibration study

BackgroundSodium and potassium measured in 24-h urine collections are often used as reference measurements to validate self-reported dietary intake instruments. ObjectivesTo evaluate whether collection and analysis of a limited number of urine voids at specified times during the day (“timed voids”) can provide alternative reference measurements, and to identify their optimal number and timing. MethodsWe used data from a urine calibration study among 441 adults aged 18–39 y. Participants collected each urine void in a separate container for 24 h and recorded the collection time. For the same day, they reported dietary intake using a 24-h recall. Urinary sodium and potassium were analyzed in a 24-h composite sample and in 4 timed voids (morning, afternoon, evening, and overnight). Linear regression models were used to develop equations predicting log-transformed 24-h urinary sodium or potassium levels using each of the 4 single timed voids, 6 pairs, and 4 triples. The equations also included age, sex, race, BMI (kg/m2), and log creatinine. Optimal combinations minimizing the mean squared prediction error were selected, and the observed and predicted 24-h levels were then used as reference measures to estimate the group bias and attenuation factors of the 24-h dietary recall. These estimates were compared. ResultsOptimal combinations found were as follows: single voids—evening; paired voids—afternoon + overnight (sodium) and morning + evening (potassium); and triple voids—morning + evening + overnight (sodium) and morning + afternoon + evening (potassium). Predicted 24-h urinary levels estimated 24-h recall group biases and attenuation factors without apparent bias, but with less precision than observed 24-h urinary levels. To recover lost precision, it was estimated that sample sizes need to be increased by ∼2.6–2.7 times for a single void, 1.7–2.1 times for paired voids, and 1.5–1.6 times for triple voids. ConclusionsOur results provide the basis for further development of new reference biomarkers based on timed voids. Clinical Trial Registryclinicaltrials.gov as NCT01631240.

The contribution of sodium reduction and potassium increase to the blood pressure lowering observed in the Salt Substitute and Stroke Study.

The Salt Substitute and Stroke Study (SSaSS) demonstrated significant reductions in systolic blood pressure (SBP), and the risk of stroke, major cardiovascular events and total mortality with the use of potassium-enriched salt. The contribution of sodium reduction versus potassium increase to these effects is unknown. We identified four different data sources describing the association between sodium reduction, potassium supplementation and change in SBP. We then fitted a series of models to estimate the SBP reductions expected for the differences in sodium and potassium intake in SSaSS, derived from 24-h urine collections. The proportions of the SBP reduction separately attributable to sodium reduction and potassium supplementation were calculated. The observed SBP reduction in SSaSS was -3.3 mmHg with a corresponding mean 15.2 mmol reduction in 24-h sodium excretion and a mean 20.6 mmol increase in 24-h potassium excretion. Assuming 90% of dietary sodium intake and 70% of dietary potassium intake were excreted through urine, the models projected falls in SBP of between -1.67 (95% confidence interval: -4.06 to +0.73) mmHg and -5.33 (95% confidence interval: -8.58 to -2.08) mmHg. The estimated proportional contribution of sodium reduction to the SBP fall ranged between 12 and 39% for the different models fitted. Sensitivity analyses assuming different proportional urinary excretion of dietary sodium and potassium intake showed similar results. In every model, the majority of the SBP lowering effect in SSaSS was estimated to be attributable to the increase in dietary potassium rather than the fall in dietary sodium.

Accuracy and precision of dried urine spot method for the detection of Schistosoma mansoni circulating cathodic antigens in resource-limited settings

BackgroundThe World Health Organization recommends the use of Schisto point-of-care circulating cathodic antigens (Schisto POC-CCA) for screening of Schistosoma mansoni as it offers better sensitivity than microscopy. However, there are limitation facing the use of this method including timely availability of the test cassettes. The aim of this study was to determine the reliability of dried urine spot (DUS) method for collection of urine and detection of S. mansoni using Schisto POC-CCA cassettes in a resource-limited settings.MethodsA cross-sectional study was conducted between October and November 2022 among 250 primary school children in Sengerema District, northwestern Tanzania. S. mansoni CCA was detected in filter paper-based DUS, liquid urine using DUS Schisto POC-CCA (index), and direct urine Schisto POC-CCA (comparator) methods respectively. S. mansoni eggs in stool were detected using duplicate Kato-Katz (KK) method. The measures of accuracy were computed and compared between the index and comparator methods. The strength of agreement between inter-raters precisions was tested using Cohen’s kappa (k).ResultsThis study revealed S. mansoni prevalence rates of 28.8%, 54.0% and 50.8% by duplicate KK, direct urine Schisto POC-CCA and DUS Schisto POC-CCA methods respectively. The mean intensity of infection among infected participants was 86.3 eggs per gram of stool (EPG) ranging from 12.0 EPG to 824.0 EPG. The sensitivity of DUS Schisto POC-CCA and direct urine Schisto POC-CCA was 94.44% (95% CI: 89.15–99.74%) and 97.22% (95% CI: 93.43–100.00%) respectively. The DUS Schisto POC-CCA method had slightly higher specificity (66.85%) than direct urine Schisto POC-CCA method (63.48%). The accuracy of the DUS Schisto POC-CCA was found to be slightly high (74.80%, 95% CI: 68.94–79.06%) compared to that of direct urine Schisto POC-CCA (73.20%, 95% CI: 67.25–78.59%). There was good agreement between two laboratory technologists who performed the DUS Schisto POC-CCA method on similar samples (k = 0.80, 95% CI: 0.59–0.95).ConclusionsThe DUS Schisto POC-CCA method had comparable S. mansoni detection accuracy to direct urine Schisto POC-CCA. This suggests that the method could be a potential alternative to direct urine Schisto POC-CCA for screening S. mansoni in resource-limited situations.Graphical

Sodium intake and public health -- methodological pitfalls in assessing the relationship between sodium intake and health outcomes

Background and aims The findings on the relationship between sodium intake and health outcomes such as cardiovascular disease and all-cause mortality have been controversial. Some studies found the relationship between sodium intake and all-cause mortality was linear while others found a U-shaped or J-shaped relationship. This study aimed to identify the methodological issues contributing to the conflicting findings. Methods and results The present study investigated methodological gaps in assessing the relationship between sodium intake and health outcomes (hypertension, cardiovascular disease, and all-cause mortality). The contradictory findings appear to stem from flawed methods used in the published studies: (1) Both spot and 24-h urinary sodium collection methods underestimate the adverse effects of low sodium intake and overestimate the harmful effects of high sodium intake, (2) the linear relationship between sodium intake and all-cause mortality appears to be a result of random chance due to small sample sizes, and (3) the divergent temporal trends of sodium consumption and hypertension prevalence indicate sodium intake was not the primary cause of the worldwide hypertension epidemic. Conclusion Considering, (1) sodium is an essential nutrient, (2) the adverse effects of low and high sodium intake appear to be under- and over-estimated, respectively, (3) large studies have found a U-shaped or J-shaped relationship between sodium intake and all-cause mortality, and (4) sodium consumption is unlikely to be the major driver behind the worldwide hypertension epidemic and has little effect on the blood pressure of most normotensive individuals, the recommendation for population-wide low sodium intake merits further evaluation.

Preventive Pharmacological Therapy and Risk of Recurrent Urinary Stone Disease.

Urinary stone disease is a prevalent condition associated with a high recurrence risk. Preventive pharmacological therapy has been proposed to reduce recurrent stone episodes. However, limited evidence exists regarding its effectiveness, contributing to its underutilization by physicians. This study aimed to evaluate the association between preventive pharmacological therapy (thiazide diuretics, alkali therapy, and uric acid-lowering medications) and clinically significant urinary stone disease recurrence. Using data from the Veterans Health Administration, adults with an index episode of urinary stone disease from 2012 through 2019 and at least one urinary abnormality (hypercalciuria, hypocitraturia, or hyperuricosuria) on 24-hour urine collection were included. The primary outcome was a composite variable representing recurrent stone events that resulted in emergency department visits, hospitalizations, or surgery for urinary stone disease. Cox proportional hazards regression was performed to estimate the association between preventive pharmacological therapy use and recurrent urinary stone disease while adjusting for relevant baseline patient characteristics. Among the cohort of patients with urinary abnormalities ( n =5637), treatment with preventive pharmacological therapy was associated with a significant 19% lower risk of recurrent urinary stone disease during the 12-36-month period after the initial urine collection (hazard ratio, 0.81; 95% confidence interval, 0.65 to 1.00; P = 0.0496). However, the effectiveness of preventive pharmacological therapy diminished over longer follow-up periods (12-48 and 12-60 months after the urine collection) and did not reach statistical significance. When examining specific urinary abnormalities, only alkali therapy for hypocitraturia was associated with a significant 26% lower recurrence risk within the 12-36-month timeframe (hazard ratio, 0.74; 95% confidence interval, 0.56 to 0.97; P = 0.03). When considering all urinary abnormalities together, this study demonstrates that the use of preventive pharmacological therapy is associated with a lower risk of clinically significant recurrent episodes of urinary stone disease in the 12-36 month timeframe after urine collection, although only the association with the use of alkali therapy for hypocitraturia was significant when individual abnormalities were examined.

Assessment of baby disposable diapers application for urine collection and determination of phthalate metabolites

The baby disposable diapers were investigated as a sampling material for urine collection and validated for the evaluation of the exposure of children to xenobiotics. Phthalate metabolites detected in urine samples were chosen as proof-of-concept analytes. For the determination of phthalate metabolites in children’s urine samples, high performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) was used. Two sampling approaches were compared, namely sterile containers and baby disposable diapers. Thirty urine samples from infants and toddlers were analyzed by both methods in parallel and the results were compared. It was found that for diaper sampling, lower concentrations of the metabolites were observed, however, the general distribution for particular metabolites remains the same for both methods. For most of the metabolites high determination coefficients were obtained, namely 0.9929 for MEHHP, 0.9836 for MMP, 0.9796 for MECPP, and 0.9784 for 2-cx-MMHP. For MEOHP the determination correlation coefficient was 0.9154, while for MBP was – 0.7771 and MEHP was – 0.5228. In general, for diaper sampling an underestimation for 2-cx-MMHP and MEOHP was observed, while for MMP diaper-based approach provides overestimation. However, the proposed procedure confirms the possibility of using baby disposable diapers as a material for the collection of urine samples for biomonitoring purposes and fast screening of phthalates exposure.

Protein intake and its relationship with frailty in chronic kidney disease.

Patients with chronic kidney disease (CKD) are susceptible to frailty because of a range of nutrition-related factors. While protein restriction is commonly advised to preserve kidney function in patients with CKD, insufficient protein intake could potentially exacerbate frailty risk. This study aimed to elucidate the relationship between frailty and protein intake in patients with CKD. This cross-sectional study enrolled patients with CKD stage 3-5. Frailty and prefrailty were assessed using the Japanese version of the Cardiovascular Health Study (J-CHS) criteria. To estimate dietary protein intake, Maroni's formula based on 24-h urine collection was used. The potential association between frailty/pre-frailty and protein intake was investigated using a logistic regression analysis. Ninety-seven individuals with CKD were included in the study, with a median age of 73.0years (interquartile range: 67.0, 82.0). Among them, 34 were women (35.1%), and the estimated glomerular filtration rate (eGFR) was 36.3mL/min/1.73 m2 (interquartile range: 26.9, 44.1). Frailty and pre-frailty were identified in 13.4% and 55.7% of participants, respectively. Comparing the groups, protein intake in the frailty/pre-frailty group (0.83g/kgBW/day [0.72, 0.93]) was lower than that in the robust group (0.89g/kgBW/day [0.84, 1.19], p = 0.002). Upon logistic regression analysis, protein intake exhibited an independent association with frailty/pre-frailty (odds ratio: 0.72, 95% confidence interval: 0.59-0.89, p = 0.003). Reduced protein intake in patients with CKD is associated with frailty and pre-frailty. It is advisable to ensure that patients with CKD who are at risk of frailty consume an adequate amount of protein.

Magnetic resonance elastography resolving all gross anatomical segments of the kidney during controlled hydration.

Introduction: Magnetic resonance elastography (MRE) is a non-invasive method to quantify biomechanical properties of human tissues. It has potential in diagnosis and monitoring of kidney disease, if established in clinical practice. The interplay of flow and volume changes in renal vessels, tubule, urinary collection system and interstitium is complex, but physiological ranges of in vivo viscoelastic properties during fasting and hydration have never been investigated in all gross anatomical segments simultaneously. Method: Ten healthy volunteers underwent two imaging sessions, one following a 12-hour fasting period and the second after a drinking challenge of >10mL per kg body weight (60-75min before the second examination). High-resolution renal MRE was performed using a novel driver with rotating eccentric mass placed at the posterior-lateral wall to couple waves (50Hz) to the kidney. The biomechanical parameters, shear wave speed (cs in m/s), storage modulus (Gd in kPa), loss modulus (Gl in kPa), phase angle and attenuation (α in 1/mm) were derived. Accurate separation of gross anatomical segments was applied in post-processing (whole kidney, cortex, medulla, sinus, vessel). Results: High-quality shear waves coupled into all gross anatomical segments of the kidney (mean shear wave displacement: 163 ± 47μm, mean contamination of second upper harmonics <23%, curl/divergence: 4.3 ± 0.8). Regardless of the hydration state, median Gd of the cortex and medulla (0.68 ± 0.11kPa) was significantly higher than that of the sinus and vessels (0.48 ± 0.06kPa), and consistently, significant differences were found in cs, , and Gl (all p < 0.001). The viscoelastic parameters of cortex and medulla were not significantly different. After hydration sinus exhibited a small but significant reduction in median Gd by -0.02 ± 0.04kPa (p = 0.01), and, consequently, the cortico-sinusoidal-difference in Gd increased by 0.04 ± 0.07kPa (p = 0.05). Only upon hydration, the attenuation in vessels became lower (0.084 ± 0.013 1/mm) and differed significantly from the whole kidney (0.095 ± 0.007 1/mm, p = 0.01). Conclusion: High-resolution renal MRE with an innovative driver and well-defined 3D segmentation can resolve all renal segments, especially when including the sinus in the analysis. Even after a prolonged hydration period the approach is sensitive to small hydration-related changes in the sinus and in the cortico-sinusoidal-difference.

Correlation of urinary comprehensive genomic profile with risk of recurrence of BCG-unresponsive non-muscle invasive bladder cancer treated with atezolizumab in SWOG S1605.

529 Background: Radical cystectomy is recommended for patients with BCG-unresponsive (BU) non-muscle invasive bladder cancer (NMIBC) due to high risk of progression. Improved methods for assessing these risks would greatly facilitate the potential for bladder preservation. Here, we tested the capacity of the urinary comprehensive genomic profile (uCGP) to predict event-free survival (EFS) in patients with BU-NMIBC treated with atezolizumab in the single arm phase 2 trial SWOG S1605. Methods: Urine was collected from patients with BU NMIBC (CIS, Ta, T1) treated with at least one dose of intravenous atezolizumab at baseline and before the 5th cycle of therapy (3 months). The uCGP was assessed using UroAmp (Convergent Genomics). Risk scores for recurrence at baseline and at 3 months were calculated by a prespecified machine learning algorithm incorporating alterations in 60 genes and low pass whole genome sequencing, and categorized as high versus low. Molecular response was classified based on change in uCGP between the two time points. Risk scores and molecular response were submitted to SWOG for clinical correlation with EFS using a Cox model, adjusting for CIS status. Time to event was calculated from date of study entry (baseline risk) or from the 2nd collection time (3-month risk) to first high grade (HG) recurrence or persistent CIS at 3 months. Death unrelated to bladder cancer and patients last known to be alive without HG recurrence were censored at date of last visit. Results: Samples were provided at baseline in 89 patients and before the 5th cycle in 77; 68 had both samples available for paired analysis. The risk score at baseline was classified as high in 69% of samples (73% for CIS ±Ta/T1 and 62% for Ta/T1). At 12 and 18 months the EFS probabilities were 26% and 23% for high-risk and 67% and 51% for low-risk patients, respectively, with a HR of 2.82 (95% CI: 1.58, 5.03; p&lt;0.001). The risk score at the 3-month timepoint was classified as high in 81% of samples, and the EFS probabilities at 12 and 18 months after urine collection were 26% and 22% for high-risk and 80% and 72% for low-risk patients, respectively, with a HR of 3.39 (95% CI: 1.41, 8.13; p&lt;0.006). Molecular response to treatment was classified as complete (CR) in 8%, partial (PR) in 14%, stable (SD) in 25% and progression (PD) in 46%, with 7% having no detectable genomic abnormalities at both time points. Clinical recurrence was observed by 18 months in 0/6 patients with CR, 7/9 (78%) with PR, 11/14 (79%) with SD and 25/33 (76%) with PD by genomic profile. Conclusions: This study suggests that uCGP at baseline and after 4 cycles of treatment can identify genomic patterns associated with an increased risk of HG persistence, recurrence or progression in BU NMIBC treated with immune checkpoint inhibition. Future studies will determine if this can be used to guide early treatment intensification.

Isoniazid urine spectrophotometry for prediction of serum pharmacokinetics in adults with TB.

Isoniazid (INH) is an important drug in many TB regimens, and unfavorable treatment outcomes can be caused by suboptimal pharmacokinetics. Dose adjustment can be personalized by measuring peak serum concentrations; however, the process involves cold-chain preservation and laboratory techniques such as liquid chromatography (LC)/mass spectrometry (MS), which are unavailable in many high-burden settings. Urine spectrophotometry could provide a low-cost alternative with simple sampling and quantification methods. We enrolled 56 adult patients on treatment for active TB. Serum was collected at 0, 1, 2, 4, 6, and 8 h for measurement of INH concentrations using validated LC-MS/MS methods. Urine was collected at 0-4, 4-8, and 8-24 h intervals, with INH concentrations measured using colorimetric methods. The median peak serum concentration and total serum exposure over 24 h were 4.8 mg/L and 16.4 mg*hour/L, respectively. Area under the receiver operator characteristic curves for urine values predicting a subtherapeutic serum concentration (peak <3.0 mg/L) were as follows: 0-4 h interval (AUC 0.85, 95% CI 0.7-0.96), 0-8 h interval (AUC 0.85, 95% CI 0.71-0.96), and 0-24 h urine collection interval (AUC 0.84, 95% CI 0.68-0.96). Urine spectrophotometry may improve feasibility of personalized dosing in high TB burden regions but requires further study of target attainment following dose adjustment based on a urine threshold.