Urine Lactate Research Articles

A Multi-Target Pharmacological Correction of a Lipoyltransferase LIPT1 Gene Mutation in Patient-Derived Cellular Models.

Mutations in the lipoyltransferase 1 (LIPT1) gene are rare inborn errors of metabolism leading to a fatal condition characterized by lipoylation defects of the 2-ketoacid dehydrogenase complexes causing early-onset seizures, psychomotor retardation, abnormal muscle tone, severe lactic acidosis, and increased urine lactate, ketoglutarate, and 2-oxoacid levels. In this article, we characterized the disease pathophysiology using fibroblasts and induced neurons derived from a patient bearing a compound heterozygous mutation in LIPT1. A Western blot analysis revealed a reduced expression of LIPT1 and absent expression of lipoylated pyruvate dehydrogenase E2 (PDH E2) and alpha-ketoglutarate dehydrogenase E2 (α-KGDH E2) subunits. Accordingly, activities of PDH and α-KGDH were markedly reduced, associated with cell bioenergetics failure, iron accumulation, and lipid peroxidation. In addition, using a pharmacological screening, we identified a cocktail of antioxidants and mitochondrial boosting agents consisting of pantothenate, nicotinamide, vitamin E, thiamine, biotin, and α-lipoic acid, which is capable of rescuing LIPT1 pathophysiology, increasing the LIPT1 expression and lipoylation of mitochondrial proteins, improving cell bioenergetics, and eliminating iron overload and lipid peroxidation. Furthermore, our data suggest that the beneficial effect of the treatment is mainly mediated by SIRT3 activation. In conclusion, we have identified a promising therapeutic approach for correcting LIPT1 mutations.

Glycolytic lactate in diabetic kidney disease.

Lactate elevation is a well-characterized biomarker of mitochondrial dysfunction, but its role in diabetic kidney disease (DKD) is not well defined. Urine lactate was measured in patients with type 2 diabetes (T2D) in 3 cohorts (HUNT3, SMART2D, CRIC). Urine and plasma lactate were measured during euglycemic and hyperglycemic clamps in participants with type 1 diabetes (T1D). Patients in the HUNT3 cohort with DKD had elevated urine lactate levels compared with age- and sex-matched controls. In patients in the SMART2D and CRIC cohorts, the third tertile of urine lactate/creatinine was associated with more rapid estimated glomerular filtration rate decline, relative to first tertile. Patients with T1D demonstrated a strong association between glucose and lactate in both plasma and urine. Glucose-stimulated lactate likely derives in part from proximal tubular cells, since lactate production was attenuated with sodium-glucose cotransporter-2 (SGLT2) inhibition in kidney sections and in SGLT2-deficient mice. Several glycolytic genes were elevated in human diabetic proximal tubules. Lactate levels above 2.5 mM potently inhibited mitochondrial oxidative phosphorylation in human proximal tubule (HK2) cells. We conclude that increased lactate production under diabetic conditions can contribute to mitochondrial dysfunction and become a feed-forward component to DKD pathogenesis.

Urine tricarboxylic acid cycle metabolites and risk of end stage kidney disease in patients with type 2 diabetes.

Metabolites in tricarboxylic acid (TCA) pathway have pleiotropic functions. To study the association between urine TCA cycle metabolites and the risk for chronic kidney disease (CKD) progression in individuals with type 2 diabetes. A prospective study in a discovery (n = 1826) and a validation (n = 1235) cohort of type 2 diabetes in a regional hospital and a primary care facility. Urine lactate, pyruvate, citrate, alpha-ketoglutarate, succinate, fumarate and malate were measured by mass spectrometry. CKD progression was defined as a composite of sustained eGFR below 15 ml/min/1.73 m2 , dialysis, renal death or doubling of serum creatinine. During a median of 9.2 (IQR 8.1-9.7) and 4.0 (3.2-5.1) years of follow-up, 213 and 107 renal events were identified. Cox regression suggested that urine lactate, fumarate and malate were associated with an increased risk (adjusted hazard ratio, aHR [95% CI] 1.63 [1.16-2.28], 1.82 [1.17-2.82] and 1.49 [1.05-2.11], per SD), while citrate was associated with a low risk (aHR 0.83 [0.72-0.96] per SD) for the renal outcome after adjustment for cardio-renal risk factors. These findings were reproducible in the validation cohort. Noteworthy, fumarate and citrate were independently associated with the renal outcome after additional adjustment for other metabolites. Urine fumarate and citrate predict the risk for progression to ESKD independent of clinical risk factors and other urine metabolites. These two metabolites in TCA cycle pathway may play important roles in the pathophysiological network underpinning progressive loss of kidney function in patients with type 2 diabetes.

12-OR: Urine Lactate Is a Disease Biomarker for Diabetic Kidney Disease

As lactate (LA) elevation is associated with mitochondrial dysfunction, we examined the role of LA in diabetic kidney disease (DKD) progression. Urine LA (ULA) was measured in patients with type 2 diabetes (T2D) in three independent cohort studies (HUNT3, SMART2D, and CRIC). ULA and plasma LA (PLA) were also measured in patients with type 1 diabetes (T1D) following eu- or hyperglycemic clamp, in mouse kidney sections, and sodium-glucose cotransporter-2 (SGLT2)-deficient mice. Mitochondrial functional changes in human kidney proximal tubule (HK2) cells were assayed in response to exogenous LA. Subjects in HUNT3 with DKD (n=39) had elevated ULA levels compared to healthy controls (n=53, p=0.023) (Fig. 1). In subjects with T2D from SMART2D (n=230) and CRIC (n=889), the third tertile of ULA/creatinine ratio was associated with a greater estimated glomerular filtration rate (eGFR) decline [-1.63 mL/min/1.73m2/year, p=0.007, and -0.63 mL/min/1.73m2, p=0.042], relative to the first tertile. Acute hyperglycemia stimulated PLA (p<0.0001) and ULA (p=0.001) in patients with T1D (n=39), and in kidney sections incubated with high glucose. Compared to wild-type, SGLT2-deficient mice had lower ULA levels. LA above 2.5 mM inhibited oxygen consumption rate in HK2 cells. Elevated ULA/creatinine ratio inhibits mitochondrial function in diabetes and identifies subjects at risk of rapid renal decline independent of chronic glycemic control. Disclosure L.Kugathasan: None. L.Natarajan: None. S.Lim: None. S.Waikar: None. Y.M.Osman: None. J.He: None. V.Vallon: Research Support; NIH - National Institutes of Health, Gilead Sciences, Inc., Merck Sharp & Dohme Corp., Novo Nordisk, Maze Therapeutics, Boehringer-Ingelheim, Speaker's Bureau; AstraZeneca. S.Hallan: None. D.Cherney: Other Relationship; Boehringer Ingelheim-Lilly, Merck, AstraZeneca, Sanofi, Mitsubishi-Tanabe, Abbvie, Janssen, Bayer, Prometic, BMS, Maze, Gilead, CSL-Behring, Otsuka, Novartis, Youngene, Lexicon and Novo-Nordisk, Research Support; Boehringer Ingelheim-Lilly, Merck, Janssen, Sanofi, AstraZeneca, CSL-Behring and Novo-Nordisk. K.Sharma: Advisory Panel; Reata Pharmaceuticals, Inc., Otsuka America Pharmaceutical, Inc. Cric study investigators: n/a. M.Darshi: Employee; Janssen Research & Development, LLC. V.Srinivasan sridhar: Other Relationship; Merck & Co., Inc. V.Drel: None. J.Tumova: None. J.Liu: None. J.Wang: None. B.A.Perkins: Advisory Panel; Dexcom, Inc., Insulet Corporation, Novo Nordisk, Sanofi, Vertex Pharmaceuticals Incorporated, Other Relationship; Abbott, Medtronic, Sanofi, Research Support; Novo Nordisk, Bank of Montreal (BMO). Y.Lytvyn: None.

Urine lactate concentration as a non-invasive screener for metabolic abnormalities: Findings in children with autism spectrum disorder and regression.

There is increasing evidence that diseases caused by dysfunctional mitochondria (MD) are associated with autism spectrum disorder (ASD). A comprehensive meta-analysis showed that developmental regression was reported in half of the children with ASD and mitochondrial dysfunction which is much higher than in the general population of ASD. The aim of the present exploratory study was to determine lactate concentrations in urine of children with ASD, as a non-invasive large-scale screening method for metabolic abnormalities including mitochondrial dysfunction and its possible association with regression. First, clinical characteristics of MD were examined in 99 children (3-11 years) with ASD. Second, clinical characteristics of MD, severity of ASD and reported regression were compared between children with the 20% lowest lactate concentrations and those with the 20% highest lactate concentrations in urine. Third, clinical characteristics of MD and lactate concentration in urine were compared in children with (n = 37) and without (n = 62) reported regression. An association of urine lactate concentrations with mitochondrial dysfunction and regression could not be demonstrated in our large ASD cohort. However, since ASD children were reported by their parents to show a broad range of phenotypic characteristics of MD (e.g., gastro-intestinal and respiratory impairments), and lactate concentrations in urine are not always increased in individuals with MD, the presence of milder mitochondrial dysfunction cannot be excluded. Development of alternative biomarkers and their implementation in prospective studies following developmental trajectories of infants at elevated likelihood for ASD will be needed in the future to further unravel the association of ASD with mitochondrial dysfunction and eventually improve early detection.

Canine urinary lactate and cortisol metabolites in hypercortisolism, nonadrenal disease, congestive heart failure, and health.

Spontaneous hypercortisolism (HC) is a common endocrine disease of senior dogs, often overlapping in selected clinical signs and hematologic and blood biochemical abnormalities with nonadrenal diseases (NADs). HC and NAD could differentially affect cortisol metabolism, which is a complex 10-enzymatic pathway process. HC might also affect blood and urine lactate levels through its effects on mitochondrial function. We aimed to differentiate between HC and NAD via a urinary cortisol metabolites and lactate panel. We prospectively recruited 7 healthy dogs and 18 dogs with HC, 15 with congestive heart failure (CHF), and 9 with NAD. We analyzed urine by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. We normalized urinary lactate and cortisol metabolites to urine creatinine concentration, and then compared groups using a linear-mixed model and principal component (PC) analysis. A machine-learning classification algorithm generated a decision tree (DT) model for predicting HC. The least-squares means of normalized urinary 6β-hydroxycortisol and PC1 of the HC and CHF groups were higher than those of the healthy and NAD groups (p = 0.05). Creatinine-normalized urinary 6β-hydroxycortisol had better sensitivity (Se, 0.78; 95% CI: 0.55-0.91), specificity (Sp, 0.89; 95% CI: 0.57-0.99), and a likelihood ratio (LR; 7), than the Se (0.72; 95% CI: 0.49-0.88), Sp (0.89; 95% CI: 0.57-0.99), and LR (6.5) of PC1 for distinguishing HC from NAD. Lactate and dihydrocortisone had the highest decreasing node-weighted impurity value and were considered the most important features in the DT model; dihydrocortisol had no role in determining whether a dog had HC.

Bout duration in high-intensity interval exercise modifies hematologic, metabolic and antioxidant responses

Background/ObjectivesThis study compared hematologic, metabolic and antioxidant responses between three high-intensity interval exercise (HIIE) trials of different bout duration and a continuous exercise trial (CON), all with equal average intensity, total work, and duration. MethodsEleven healthy young males performed four trials involving 20 min of cycling, either continuously (49% of power at VO2max, PPO), or intermittently with 48 10-s bouts (HIIE10), 16 30-s bouts (HIIE30) or 8 60-s bouts (HIIE60) at 100% PPO, with a 1:1.5 work-to-recovery ratio at 15% PPO. Venous blood was obtained before, immediately after, and 1 h post-exercise to evaluate hematologic, metabolic and antioxidant responses. Blood lactate concentration was measured in capillary blood during exercise, while urine lactate was measured before and 1 h post-exercise. ResultsPost-exercise leukocyte count (mean ± SD; 9.7 ± 2.8 k μL−1), uric acid concentration (0.35 ± 0.10 mmol L−1), glucose concentration (6.56 ± 1.44 mmol L−1), and plasma volume change (−13.5 ± 4.4%) were greater in HIIE60 compared to all other trials (p < 0.05). One-hour post-exercise, lymphocytes decreased below pre-exercise values in all HIIE trials, and uric acid increased in the HIIE60 trial (p < 0.05). Urine lactate concentration 1 h post-exercise increased compared to pre-exercise only in HIIE60 (19-fold, p < 0.001), and this was related with the higher blood lactate concentration during exercise in that trial. ConclusionsThese findings highlight the importance of bout duration, given that shorter bouts of HIIE (30 s or 10 s) induce lower blood cell perturbations, metabolic stress, and antioxidant responses compared to the commonly used 1-min bouts, despite equal total work, duration, and work-to-recovery ratio.

Urine Lactate after Continuous and Interval Cycling Exercise Bouts Eliciting Different Blood Lactate Concentrations

Post-exercise urine lactate (UL) has been suggested as a novel exercise biomarker of lactate production. The few studies examining the association between post-exercise peak blood lactate (BL) and UL have reported moderate to high linear correlations. However, these studies have not considered BL concentration during exercise. Also, the range of BL values was narrow (about 10 mmol/L), thus limiting the predictive value of UL. PURPOSE: To examine the association between UL and BL concentrations during continuous and interval exercise of equal mean power. METHODS: Eleven healthy young males performed four trials in random, counterbalanced order, one week apart. All trials included 20 min of cycling with equal mean power output, performed either continuously (CON) or in the form of interval training including 48 x 10 s (HIIT10), 16 x 30 s (HIIT30), or 8 x 60 s (HIIT60) bouts at a power output corresponding to 100% of VO2max. Recovery intervals during the HIIT trials included cycling at 15% of VO2max for 150% of the exercise bout time. Capillary BL concentration was measured at rest and every 5 min during exercise, and UL concentration was measured in urine samples obtained pre- and 1 hour post-exercise, with controlled hydration. BL and UL results were analyzed using 2-way ANOVA with repeated measures (trial x time). The association between incremental area under the blood lactate curve (BL-AUC) and UL concentration was determined using linear and exponential functions. RESULTS: BL increased compared with baseline in all trials from the first 5 min of exercise (p < 0.01). BL-AUC increased from CON to HIIT10, HIIT30 and HIIT60 (61.7 ± 21.2, 83.4 ± 29.0, 97.8 ± 34.0, 147.4 ± 44.2 mmol/L x min, respectively, p < 0.01). However, post-exercise UL increased from baseline only in HIIT60 (from 1.2 ± 1.0 to 22.5 ± 23.3 mmol/L, p < 0.001). Exercise BL ranged from 3.0 to 17.7 mmol/L, while post-exercise UL ranged from 0.2 to 76.4 mmol/L. The best function describing the BL-AUC and UL relationship was exponential (r = 0.68, p < 0.05). CONCLUSIONS: The lack of increase in UL despite an increase in BL and their exponential association suggest that there may be a threshold above which BL cannot be disposed within the body and is excreted by the kidneys.

520-P: Hyperglycemia-Induced Mitochondrial Dysfunction in Diabetic Kidney Disease May Be Mediated by Crabtree Effect in Kidney Proximal Tubule Epithelial Cells

Background: Recent studies indicate mitochondrial dysfunction is a dominant pathway in diabetic kidney disease (DKD), however underlying mechanisms are unclear. Here we examined if Crabtree effect by glucose is a cause of mitochondrial dysfunction in kidney. Methods: Lactate was measured by by YSI biochemistry analyzer. TCA cycle metabolites were measured by gas chromatography mass spectroscopy in urine samples of type 1 and type 2 DKD mouse models. Changes in oxygen consumption (OCR) and extracellular acidification i(ECAR) were analyzed on a Seahorse extracellular flux analyzer. Immunohistochemical analysis was performed on FFPE-embedded mouse kidney sections. Western blot analysis was performed on kidney cortical sections and HK2 cells. Results: Significantly increased urine and plasma lactate along with a decrease in several TCA cycle metabolites were observed in both type 1 and type 2 diabetic mice. Mitochondrial functional analysis in different kidney cells showed a profound respiratory inhibition and stimulation of lactate by glucose in proximal tubules, but not in mesangial cells and podocytes. Pyruvate at above physiological concentration reversed the glucose-induced inhibition of OCR. Western blotting of kidney cortical tissue sections showed a significant increase in phospho PDH in diabetic kidney tissues and in HK2 cells treated with high glucose. In normal conditions, phospho PDH was predominantly on distal tubules, however in diabetic conditions a significant increase in phospho PDH was noted in proximal tubule cells. Dichloroacetate, an inhibitor of PDK completely reversed the glucose induced respiratory inhibition in proximal tubule epithelial cells. Conclusions: Mitochondrial dysfunction in proximal tubule epithelial cells may potentially be due to high-glucose induced PDH phosphorylation resulting in limited pyruvate oxidation into mitochondria and enhanced lactate production. Disclosure M. Darshi: None. J.J. Kim: None. V. Drel: None. A.N. Murphy: Advisory Panel; Self; Cytokinetics Inc. Consultant; Self; Agilent Technologies. Funding JDRF; U.S. Department of Veterans Affairs

Urinary metabolites predict prolonged duration of delayed graft function in DCD kidney transplant recipients.

Extending kidney donor criteria, including donation after circulatory death (DCD), has resulted in increased rates of delayed graft function (DGF) and primary nonfunction. Here, we used Nuclear Magnetic Resonance (NMR) spectroscopy to analyze the urinary metabolome of DCD transplant recipients at multiple time points (days 10, 42, 180, and 360 after transplantation). The aim was to identify markers that predict prolonged duration of functional DGF (fDGF). Forty-seven metabolites were quantified and their levels were evaluated in relation to fDGF. Samples obtained at day 10 had a different profile than samples obtained at the other time points. Furthermore, at day 10 there was a statistically significant increase in eight metabolites and a decrease in six metabolites in the group with fDGF (N=53) vis-à-vis the group without fDGF (N=22). In those with prolonged fDGF (≥21days) (N=17) urine lactate was significantly higher and pyroglutamate lower than in those with limited fDGF (<21days) (N=36). In order to further distinguish prolonged fDGF from limited fDGF, the ratios of all metabolites were analyzed. In a logistic regression analysis, the sum of branched-chain amino acids (BCAAs) over pyroglutamate and lactate over fumarate, predicted prolonged fDGF with an AUC of 0.85. In conclusion, kidney transplant recipients with fDGF can be identified based on their altered urinary metabolome. Furthermore, two ratios of urinary metabolites, lactate/fumarate and BCAAs/pyroglutamate, adequately predict prolonged duration of fDGF.

Improved reliability of the urine lactate concentration under controlled hydration after maximal exercise

Context: Urine lactate may be a novel biomarker of lactate production capacity but its reliability has been unsatisfactory so far.Objective: To compare the reliability of urine lactate between controlled hydration and no hydration after maximal exercise.Material and methods: Athletes performed swimming exercise four times: two followed by consumption of 1 L of water and two followed by no water intake. Blood and urine lactate was measured.Results: The reliability of urine lactate was good and similar to that in blood only after controlled hydration. Blood and urine lactate were correlated under both hydration conditions.Discussion and conclusion: Controlled hydration after exercise provides satisfactory reliability of urine lactate.

Reliability of urine lactate as a novel biomarker of lactate production capacity in maximal swimming

Context: Postexercise urine lactate may be a novel biomarker of lactate production capacity during exercise.Objective: To evaluate the reliability and utility of the urine lactate concentration after maximal swimming trials between different training protocols (6 × 50 m and 3 × 100 m) and training states (active and nonactive swimmers).Materials and methods: Lactate and creatinine were determined by spectrophotometry in blood and urine.Results: Blood and urine lactate concentrations were correlated in-between training protocols and in participants of different training states. The reliability of the urine lactate concentration was moderate for one of the training protocols and good or moderate for the two training states. Additionally, it was lower than that of the blood lactate concentration, and did not improve after normalizing to the urine creatinine concentration.Discussion and conclusion: Although promising as a biomarker of lactate production capacity, urine lactate requires further research to improve its reliability.

The early diagnosis of acute kidney injury after liver transplantation by urine lactate dehydrogenase, cystatin C and neutrophil gelatinase-associated lipocalin

Objective To investigate the value of urinary lactate dehydrogenase(LDH),Cystatin C (Cys-C) and neutrophil gelatinase-associated lipocalin (NGAL) in early diagnosis of acute kidney injury after liver transplantation. Methods From January 2011 to October 2011,45 patients were recruited.Blood and urinary samples were collected before operation and the end of the operation,and used to determine serum creatinine (SCr),Cys-C,LDH,and total bilirubin,as well as urinary LDH,Cys-C and NGAL.All the patients were divided into AKI and non-AKI groups,according to the Acute Kidney Injury Network (AKIN) criteria of AKI.The statistics were used along ROC analysis to evaluate the diagnose value of selected biomarkers. Results There were no significant differences in clinical parameters between AKI and non-AKI groups while 20 of the 45 patients suffered AKI [ ( 140±54)vs (81±20),P＜0.05].Urine LDH,Cys-C and NGAL raised in all the samples,and the level of the 3 enzymes in AKI group increased significantly [ (6.50±2.86)vs (3.21±1.63),P＜0.05 ],[ ( 1.55±0.54)vs (0.86±0.31),P＜0.05 ],[ ( 107±59)vs (43±11 ),P＜0.05 ].ROC analysis revealed that (AUC 0.853,0.833,0.880) the 3 enzymes are capable of early diagnosis of AKI. Conclusions Urinary LDH,Cys-C and NGAL appear to be sensitive and specific biomarkers of AKI in liver transplant recipients,but further research are needed in the future for the clinical diagnosis. Key words: Liver transplantation; Acute kidney injury ; Lactate dehydrogenase ; Cystatin C; Neutrophil gelatinaseassociated lipocalin

Serum level of neutrophii gelatinase-associated lipocalin in preeclampsia with gestational diabetes mellitus

Objective To investigate the relationship of serum neutrophil gelatinase associatedlipocalin (NGAL) levels among preeclamptic women with or without gestational diabetes mellitus (GDM),GDM and healthy pregnant controls. Methods This study included 263 singleton pregnant women who visited the antenatal chinics in Guangdong Women and Children's Hospital and Health Instutite Affiliated to Guangzhou Medical College from December 2009 to November 2010,77 healthy pregnant women,77 women with preeclampsia,77 women with GDM and 32 women complicated with both preeclampsia and GDM.Blood pressure,height and body weight of all subjects were measured.Peripheral blood samples were collected to detect serum NGAL,parameters of glycolipid metabolism,24-hour urine protein content,uric acid,creatinine and lactate dehydrogenase.Maternal levels of serum NGAL were quantified by enzyme-linked immunosorbent assay.Meanwhile,body mass index (BMI) and homeostasis model assessment for insulin resistance (HOMA-IR) were calculated. Data under normal distribution were analyzed with one-way ANOVA and Student's t test,and those under abnormal distribution were compared with Kruskal-Wallis H or Mann-Whitney U test. Results The preeclampsia with GDM group had higher serum NGAL level [(70.82±20.02) ng/ml] as compared with preeclampsia group [(56.17 ±18.22) ng/ml],GDM group [(43.99 ± 14.82) ng/ml] and healthy pregnant control group [(17.80±5.78) ng/ml],t=3.65,5.97,14.76,P＜0.01,respectively.The NGAL levels in preeclampsia group without GDM were higher than in GDM group (t=5.90,P＜0.01).In both the preeclampsia with and without GDM groups,NGAL levels in patients with severe preeclampsia were higher than in the mild ones [(76.44±28.06) ng/ml or(60.15±25.86) ng/ml,t=2.82,P＜0.05; (61.61±37.14) ng/ml or (46.30±13.97) ng/ml,t=4.74,P＜0.01].After adjusted by gesrational weeks and maternal age,NGAL level was positively correlated with BMI before pregnancy (r=0.335,P＜0.01),BMI after pregnancy (r=0.427,P＜0.01),systolic blood pressure (r=0.648,P＜0.01),diastolic blood pressure (r=0.664,P＜0.01),fasting blood glucose (r=0.320,P＜0.01),fasting insulin level (r=0.381,P＜0.01),HOMA-IR (r=0.399,P＜0.01),triglyceride level (r=0.405,P＜0.01),total cholesterol (r=0.145,P＜0.05),free fatty acids (r=0.335,P＜0.01),uric acid (r =0.292,P＜0.01),creatinine (r =0.226,P ＜ 0.01),and 24-hour urine protein content (r =0.436,P＜0.01),and negatively correlated with high density lipoprotein-cholesterol (r=-0.189,P =0.008).Stepwise regression analysis showed that systolic blood pressure (β =0.251,P ＜ 0.01),diastolic blood pressure (β=0.351,P＜0.01),HOMA-IR (β=0.265,P＜0.01) and 24-hour urine protein content (β=0.140,P=0.011) were independent factors of NGAL. Conclusions Serum NGAL levels increase significantly in patients with preeclampsia or GDM,and are correlated with parameters of glycolipid metabolism end endothelial dysfunction,which might play a role in the pathogenesis of preeclampsia and GDM. Key words: Pre-eclampsia; Diabetes, gestational; Acute-phase proteins; Proto-oncogene proteins; Lipocalins

Dihydrolipoamide dehydrogenase (DLD) deficiency in a Spanish patient with myopathic presentation due to a new mutation in the interface domain

We present a 32-year-old patient who, from age 7 months, developed photophobia, left-eye ptosis and progressive muscular weakness. At age 7 years, she showed normal psychomotor development, bilateral ptosis and exercise-induced weakness with severe acidosis. Basal blood and urine lactate were normal, increasing dramatically after effort. PDHc deficiency was demonstrated in muscle and fibroblasts without detectable PDHA1 mutations. Ketogenic diet was ineffective, however thiamine gave good response although bilateral ptosis and weakness with acidosis on exercise persisted. Recently, DLD gene analysis revealed a homozygous missense mutation, c.1440 A>G (p.I480M), in the interface domain. Both parents are heterozygous and DLD activity in the patient's fibroblasts is undetectable. The five patients that have been reported with DLD-interface mutations suffered fatal deteriorations. Our patient's disease is milder, only myopathic, more similar to that due to mutation p.G229C in the NAD(+)-binding domain. Two of the five patients presented mutations (p.D479V and p.R482G) very close to the present case (p.I480M). Despite differing degrees of clinical severity, all three had minimal clues to DLD deficiency, with occasional minor increases in α-ketoglutarate and branched-chain amino acids. In the two other patients, hypertrophic cardiomyopathy was a significant feature that has been attributed to moonlighting proteolytic activity of monomeric DLD, which can degrade other mitochondrial proteins, such as frataxin. Our patient does not have cardiomyopathy, suggesting that p.I480M may not affect the DLD ability to dimerize to the same extent as p.D479V and p.R482G. Our patient, with a novel mutation in the DLD interface and mild clinical symptoms, further broadens the spectrum of this enzyme defect.

Systematic Review of Biomarkers of Brain Injury in Term Neonatal Encephalopathy

Although neonatal hypoxic-ischemic encephalopathy is a common cause of childhood developmental disability, its timing, duration, and outcomes are poorly defined. Biomarkers serve as surrogates for disease injury, evolution, and outcome, but no tissue biomarker in routine clinical use can help predict outcomes in term newborn encephalopathy. We reviewed biomarkers in human term neonatal encephalopathy, to determine if current biomarkers are strong enough for clinical use as predictors of outcomes. A comprehensive search of databases identified 110 publications that met our inclusion criteria, i.e., (1) newborns at >36 weeks; (2) neonatal encephalopathy as defined by the American College of Obstetrics and Gynecology; (3) the use of a serum, urine, or cerebrospinal fluid biomarker; and (4) reported outcomes beyond age 12 months. Of those 110 publications, 22 reported outcomes beyond age 12 months. In single reports, urine lactate (P < 0.001), first urine S100 (P < 0.0001), cord-blood interleukin-6 (P = 0.02), serum nonprotein-bound iron (P < 0.001), serum CD14 cell NFkappaB activation (P = 0.014), serum interleukin-8 (P = 0.03), and serum ionized calcium (P = 0.001) were potential predictors of death or abnormal outcomes. A meta-analysis identified serum interleukin-1b (P = 0.04, n = 3), serum interleukin-6 (P = 0.04, n = 2), cerebrospinal fluid neuron-specific enolase (P = 0.03, n = 3), and cerebrospinal fluid interleukin-1b (P = 0.003, n = 2) as putative predictors of abnormal outcomes in survivors, when measured before age 96 hours. Several serum, urine, and cerebrospinal fluid biomarkers of term neonatal encephalopathy may provide important information regarding long-term outcomes. None, however, were studied extensively enough to warrant routine clinical use. Validation of these markers, either alone or in combination, is required in the development of viable therapeutic interventions.

Renal responses to acute lead waterborne exposure in the freshwater rainbow trout ( Oncorhynchus mykiss)

The possible nephrotoxic effects of waterborne lead exposure (as Pb(NO 3) 2) were investigated in the freshwater rainbow trout ( Oncorhynchus mykiss). Kidney lead accumulation was time-dependent, increasing upon exposure to 0.57 ± 0.01 mg dissolved Pb L −1 for up to 96 h with a significantly higher burden occurring in the posterior kidney compared to the anterior segment. Urine analyses in trout exposed to 1.20 ± 0.09 mg dissolved Pb L −1 revealed a significant increase in urinary lead excretion rate throughout 96 h of exposure. Urine flow rate and glomerular filtration rate (GFR) were not impacted with the exception of a significant decrease in GFR from 84 to 96 h in lead-exposed trout. Urine pH decreased significantly over time in lead-exposed fish. Correspondingly, urine ammonia excretion rate showed a marked increase from 48 h onwards. In experimental fish, urine glucose excretion was significantly greater by 96 h while urine lactate, urea and protein excretion were not significantly altered by lead exposure. The urine excretion rate of Ca 2+ increased significantly by approximately 43% after only 24 h of lead exposure, and was maintained at a higher rate than controls for up to 96 h. Magnesium excretion increased in a time-dependent fashion, reaching a two- to three-fold rise by 96 h. In contrast, rates of Na + and Cl − excretion were decreased in experimental fish by approximately 30% by 48 h, this trend continuing for the duration of lead-exposure. There were no changes in any of these parameters in similarly treated control fish. Clearance ratio analyses indicated progressive decreases in the net reabsorption efficiencies of the renal system for Ca 2+, Mg 2+, Pb, and glucose, suggesting that the active tubular transport mechanisms for these substances were inhibited by lead exposure, while Na +, K +, Cl −, lactate, and protein reabsorptions were unaffected. Net ammonia secretion increased. We conclude that changes in renal function both reflect and help to minimize some of the associated disturbances in systemic physiology. Lead-induced ionoregulatory toxicity in rainbow trout, particularly the disturbance of Ca 2+ homeostasis, is not exclusively a branchial phenomenon, but is in part a result of disruption of ionoregulatory mechanisms at the kidney. This action of lead outside the gills is critical to consider when developing guidelines for water quality.

Protective Effect of the Ethanol Extract of the Roots of Brassica rapa on Cisplatin-Induced Nephrotoxicity in LLC-PK1 Cells and Rats

A study was conducted to determine whether the ethanol extract of the roots of Brassica rapa (EBR) ameliorates cisplatin-induced nephrotoxicity in terms of oxidative stress, as characterized by lipid peroxidation, reactive oxygen species (ROS) production, and glutathione (GSH) depletion in LLC-PK1 cells. Pretreatment of cells with EBR prevented cisplatin-induced decreases in cell viability and cellular GSH content. The effect of EBR was then investigated in rats given EBR for 14 d before cisplatin administration. A single dose of cisplatin (7 mg/kg, i.p.) caused kidney damage manifested by an elevation in blood urea nitrogen (BUN), serum creatinine, and urine lactate dehydrogenase (LDH) levels. Also, renal tissue from cisplatin-treated rats showed a significant increase in malondialdehyde (MDA) production, and in the activities of aldehyde oxidase (AO) and xanthine oxidase (XO). Moreover, a significant decrease in the activities of antioxidant enzymes, such as, glutathione peroxidase (GPx), superoxide dismutase (SOD) and catalase (CAT) was observed in cisplatin-treated rats versus saline-treated normal group. In contrast, rats given EBR showed lower blood levels of BUN and creatinine, and of urinary LDH. Moreover, EBR prevented the rise of MDA production and the induction of AO and XO activities. This extract also recovered the reduced activities of GPx, SOD and CAT. Taken together, our data indicate that the ethanol extract of the roots of Brassica rapa (EBR) has a protective effect against cisplatin-induced nephrotoxicity because it attenuates oxidative stress.

Metabolomic approaches to mitochondrial disease: correlation of urine organic acids

In order to examine correlations which might be useful in ascertaining or confirming the diagnosis of mitochondrial disease, a retrospective analysis of urine organic acids was performed. Among 3646 analyses from randomly selected samples referred to our laboratory, there were 258 specimens from 67 patients with various known disorders of mitochondrial oxidative function, most of whom were known to have chronic and persistent elevations of blood lactic acid, and 176 samples from 21 patients with diagnosed organic acidemia. Urine lactate was not a useful discriminator; only 7.6% of results from infants with mitochondrial disease fell the 95th percentile for patients without mitochondrial disease. Most of the Krebs cycle intermediates were also not useful in discriminating patients with mitochondrial disorders. Interestingly, there was strikingly poor correlation among most of those analytes in all patient groups, but fumarate and malate were uniquely well correlated (r 2=0.840). Fumarate and malate were also the most useful in distinguishing patients with mitochondrial disease and organic acidemia from the pool of unselected or undiagnosed patients, although the utility was somewhat limited. Using a cutoff value of approximately 90 mmol/mol creatinine for fumarate or malate at age <1 year, or a cutoff of approximately 25 for older patients, 25ndash;30% of mitochondrial disease patients can be distinguished with a 5% false positive rate. Further refinements to this approach may better characterize the metabolomic profile and may improve the diagnostic utility of quantitative organic acid analysis in mitochondrial disease.

Urinary L-lactate excretion is increased in renal Fanconi syndrome.

Measurement of l-lactate in body fluids is an established clinical tool to identify disorders of cellular respiration. However, there is very little known about the clinical value of urinary lactate measurements. We investigated urinary lactate excretion in children with renal Fanconi syndrome. Freshly voided urine samples were obtained from children with Fanconi syndrome and controls both with and without renal disease. Urine lactate was estimated by conversion to pyruvate in the presence of lactate dehydrogenase and NAD. The NADH produced was measured photometrically. Urine lactate was factored for urine creatinine. Children with Fanconi syndrome had a significantly higher urine lactate/creatinine ratio [mean: 84 x 10(-2) mmol/mmol; 95% confidence interval (CI): 40.8-127.1 x 10(-2) mmol/mmol] than healthy controls (mean: 1.3 x 10(-2) mmol/mmol; CI: 1.1-1.5 x 10(-2) mmol/ mmol) and those with a variety of renal diseases (mean: 3.1 x 10(-2) mmol/mmol; CI: 1.8-4.5 x 10(-2) mmol/mmol). Urinary lactate is increased in Fanconi syndrome. The increase is likely to be due to reduced lactate co-transport in the proximal tubule. Urinary lactate/creatinine has clinical utility as a sensitive test of disordered proximal renal tubular function.