Proteomic analysis of rat kidney under maleic acid treatment by SWATH-MS technology.

RATIONALE: Maleic acid is an industrial-grade chemical that is often used in adhesives, stabilizers, and preservatives. It is unknown whether long-term consumption of maleic acid modified starch is harmful to humans. However, many studies have indicated that maleic acid causes renal tubular damage in animal models, even as the associated pathways remain unclear. Sequential window acquisition of all theoretical fragment ion spectra (SWATH) is the most innovative of the label-free quantitative technologies which have better quantification performance. Therefore, SWATH technology was used to investigate the effect of maleic acid on the rat kidney proteome in this study. METHODS: Sprague-Dawley(SD) rats were treated with 0 mg/kg (control), 6 mg/kg (low-dose), 10 mg/kg (medium-dose), and 60 mg/kg (high-dose) of maleic acid. After kidney protein extraction, 28% SDS-PAGE was used, followed by in-gel digestion and desalting. Next, the samples were analyzed with ultra-performance liquid chromatography (UPLC) coupled with quadrupole time-of-flight mass spectrometry (Q-TOF MS), and data-dependent acquisition (DDA) and SWATH technology were also used. The gene ontology and pathway analysis were accomplished. Ultimately, these protein biomarkers were validated by using scheduled high-resolution multiple reaction monitoring (sMRMHR ). RESULTS: Comparisons of the control group with the other three groups revealed that 95, 130, and 103 proteins were expressed at significantly different levels in the control group and in the low-dose, medium-dose, and high-dose groups, respectively. According to the gene ontology analysis, the major processes that these proteins were involved in were metabolic processes, biological regulation, cellular processes, and responses to stimuli; the major functions that these proteins were involved in were binding, hydrolase activity, catalytic activity, and oxidoreductase activity; and the major cellular components hat they were involved in were the cytoplasm, extracellular region, membrane, and mitochondria. According to the KEGG pathway analysis, these proteins were involved in 35 pathways, five of which, the carbohydrate metabolism, folate biosynthesis, renal tubular resorption, amino acid metabolism, and Ras signaling pathways, are discussed in this study. Ultimately, 19 proteins involved in 12 important pathways were validated by sMRMHR . CONCLUSIONS: It was demonstrated that maleic acid caused insufficient energy production, which might lead to a decrease in the activity of the sodium-potassium ATP pump and hydrogen ion ATP pump, which could in turn have caused renal tubular resorption and hydrogen ion regulation to be blocked, thus leading to the accumulation of hydrogen ions in the renal tubules, which would then result in renal tubular acidification followed finally by Fanconi syndrome.

Sulforaphane prevents maleic acid-induced nephropathy by modulating renal hemodynamics, mitochondrial bioenergetics and oxidative stress.

Maleic acid (MA)-induced nephropathy that is characterized by proteinuria, glycosuria, phosphaturia and a deficient urinary acidification and concentration. Sulforaphane (SF) is an indirect antioxidant that shows nephroprotective effects. The aim of the present work was to test the pre-treatment with SF against the MA-induced nephropathy. Wistar rats (230-260 g) were separated in the following groups: control, MA (which received 400 mg/kg of MA), SF + MA (which received MA and 1 mg/kg of SF each day for four days) and SF (which only received SF). MA induced proteinuria, an increase in urinary excretion of N-acetyl-ß-d-glucosaminidase, and a decrease in plasma glutathione peroxidase activity, renal blood flow, and oxygenation and perfusion of renal cortex. All these impairments correlated with higher levels of oxidative damage markers and exacerbated superoxide anion production on renal cortex. Moreover, MA impaired mitochondrial bioenergetics associated to complex I, mitochondrial membrane potential and respiratory control index and increased the mitochondrial production of hydrogen peroxide. Further it disrupted mitochondrial morphology. SF prevented all the above-described alterations. In conclusion, the protective effect of SF against MA-induced nephropathy is associated with preservation of mitochondrial bioenergetics, amelioration of oxidative stress and improvement of renal hemodynamics and renal cortex oxygenation.

Pharmacokinetics of Maleic Acid as a Food Adulterant Determined by Microdialysis in Rat Blood and Kidney Cortex.

Maleic acid has been shown to be used as a food adulterant in the production of modified starch by the Taiwan Food and Drug Administration. Due to the potential toxicity of maleic acid to the kidneys, this study aimed to develop an analytical method to investigate the pharmacokinetics of maleic acid in rat blood and kidney cortex. Multiple microdialysis probes were simultaneously inserted into the jugular vein and the kidney cortex for sampling after maleic acid administration (10 or 30 mg/kg, i.v., respectively). The pharmacokinetic results demonstrated that maleic acid produced a linear pharmacokinetic phenomenon within the doses of 10 and 30 mg/kg. The area under concentration versus time curve (AUC) of the maleic acid in kidney cortex was 5-fold higher than that in the blood after maleic acid administration (10 and 30 mg/kg, i.v., respectively), indicating that greater accumulation of maleic acid occurred in the rat kidney.

Comparison of the safety and efficacy of fixed-dose combination of arterolane maleate and piperaquine phosphate with chloroquine in acute, uncomplicated Plasmodium vivax malaria: a phase III, multicentric, open-label study.

BACKGROUND: Chloroquine has been the treatment of choice for acute vivax malaria for more than 60 years. Malaria caused by Plasmodium vivax has recently shown resistance to chloroquine in some places. This study compared the efficacy and safety of fixed dose combination (FDC) of arterolane maleate and piperaquine phosphate (PQP) with chloroquine in the treatment of uncomplicated vivax malaria. METHODS: Patients aged 13-65 years with confirmed mono-infection of P. vivax along with fever or fever in the previous 48 h were included. The 317 eligible patients were randomly assigned to receive FDC of arterolane maleate and PQP (n = 159) or chloroquine (n = 158) for 3 days. Primaquine was given as an anti-relapse measure on day 3 and continued for 14 consecutive days. Primary efficacy analysis included assessment of the proportion of aparasitaemic and afebrile patients at 72 h. Safety endpoints were analysis of adverse events, vital signs, laboratory data, and abnormalities on electrocardiograph. Patients participated in the study for at least 42 days. RESULTS: In per protocol population, the proportion of aparasitaemic and afebrile patients at 72 h was 100% (140/140) in the FDC of arterolane maleate and PQP group, and 99.3% (145/146) in the chloroquine group (Fisher, p > 0.9999). In intent to treat population, the corresponding value was reported to be 96.9% (154/159) in the FDC of arterolane maleate and PQP group and 98.7 % (156/158) in the chloroquine group (Fisher, p = 0.4479). The median parasite clearance time was 24 h in FDC of arterolane maleate and PQP group and 26 h in chloroquine group (Log-rank, p = 0.2264). Similarly, median fever clearance time was 24 h in both the groups (Log-rank, p = 0.7750). In PP population, day 28 cure rates were 100 % in both the groups (95% CI (96.52, 100.0 for FDC of arterolane maleate and PQP and 96.73, 100.0 in chloroquine group)). Incidence of adverse events was 82.4% in the FDC of arterolane maleate and PQP group and 85.4% in the chloroquine group. Most of the adverse events were mild to moderate in intensity. The commonly reported clinical adverse events in the FDC of arterolane maleate and PQP versus chloroquine group were vomiting (5.0 vs 5.1%), headache (1.3 vs 3.2%) and prolonged QT (1.9 vs 3.2%). No deaths were reported. The pharmacokinetic analysis indicates that arterolane maleate is well absorbed and has a relatively short t1/2 of 3.2 h. Piperaquine is also well absorbed after oral administration with a t1/2 of about 228.33 h. CONCLUSIONS: The study showed that FDC of arterolane maleate and PQP effectively cured vivax malaria and attained acceptable level of cure up to day 28. Both the groups showed similar safety profile. Trial Registration Clinical Trial Registry India: CTRI/2011/11/002129.

Toxicogenomic Screening of Replacements for Di(2-Ethylhexyl) Phthalate (DEHP) Using the Immortalized TM4 Sertoli Cell Line.

Phthalate plasticizers such as di(2-ethylhexyl) phthalate (DEHP) are being phased out of many consumer products because of their endocrine disrupting properties and their ubiquitous presence in the environment. The concerns raised from the use of phthalates have prompted consumers, government, and industry to find alternative plasticizers that are safe, biodegradable, and have the versatility for multiple commercial applications. We examined the toxicogenomic profile of mono(2-ethylhexyl) phthalate (MEHP, the active metabolite of DEHP), the commercial plasticizer diisononyl cyclohexane-1,2-dicarboxylate (DINCH), and three recently proposed plasticizers: 1,4-butanediol dibenzoate (BDB), dioctyl succinate (DOS), and dioctyl maleate (DOM), using the immortalized TM4 Sertoli cell line. Results of gene expression studies revealed that DOS and BDB clustered with control samples while MEHP, DINCH and DOM were distributed far away from the control-DOS-BDB cluster, as determined by principle component analysis. While no significant changes in gene expression were found after treatment with BDB and DOS, treatment with MEHP, DINCH and DOM resulted in many differentially expressed genes. MEHP upregulated genes downstream of PPAR and targeted pathways of cholesterol biosynthesis without modulating the expression of PPAR's themselves. DOM upregulated genes involved in glutathione stress response, DNA repair, and cholesterol biosynthesis. Treatment with DINCH resulted in altered expression of a large number of genes involved in major signal transduction pathways including ERK/MAPK and Rho signalling. These data suggest DOS and BDB may be safer alternatives to DEHP/MEHP than DOM or the commercial alternative DINCH.

Dimethyl fumarate induces necroptosis in colon cancer cells through GSH depletion/ROS increase/MAPKs activation pathway.

BACKGROUND AND PURPOSE: Dimethyl fumarate (DMF) is a newly approved drug for the treatment of relapsing forms of multiple sclerosis and relapsing-remitting multiple sclerosis. Here, we investigated the effects of DMF and its metabolites mono-methylfumarate (MMF and methanol) on different gastrointestinal cancer cell lines and the underlying molecular mechanisms involved. EXPERIMENTAL APPROACH: Cell viability was measured by the MTT or CCK8 assay. Protein expressions were measured by Western blot analysis. LDH release, live- and dead-cell staining, intracellular GSH levels, and mitochondrial membrane potential were examined by using commercial kits. KEY RESULTS: DMF but not MMF induced cell necroptosis, as demonstrated by the pharmacological tool necrostatin-1, transmission electron microscopy, LDH and HMGB1 release in CT26 cells. The DMF-induced decrease in cellular GSH levels as well as cell viability and increase in reactive oxygen species (ROS) were inhibited by co-treatment with GSH and N-acetylcysteine (NAC) in CT26 cells. DMF activated JNK, p38 and ERK MAPKs in CT26 cells and JNK, p38 and ERK inhibitors partially reversed the DMF-induced decrease in cell viability. GSH or NAC treatment inhibited DMF-induced JNK, p38, and ERK activation in CT26 cells. DMF but not MMF increased autophagy responses in SGC-7901, HCT116, HT29 and CT26 cancer cells, but autophagy inhibition did not prevent the DMF-induced decrease in cell viability. CONCLUSION AND IMPLICATIONS: DMF but not its metabolite MMF induced necroptosis in colon cancer cells through a mechanism involving the depletion of GSH, an increase in ROS and activation of MAPKs.

Synthesis and therapeutic effect of styrene-maleic acid copolymer-conjugated pirarubicin.

Previously, we prepared a pirarubicin (THP)-encapsulated micellar drug using styrene-maleic acid copolymer (SMA) as the drug carrier, in which active THP was non-covalently encapsulated. We have now developed covalently conjugated SMA-THP (SMA-THP conjugate) for further investigation toward clinical development, because covalently linked polymer-drug conjugates are known to be more stable in circulation than drug-encapsulated micelles. The SMA-THP conjugate also formed micelles and showed albumin binding capacity in aqueous solution, which suggested that this conjugate behaved as a macromolecule during blood circulation. Consequently, SMA-THP conjugate showed significantly prolonged circulation time compared to free THP and high tumor-targeting efficiency by the enhanced permeability and retention (EPR) effect. As a result, remarkable antitumor effect was achieved against two types of tumors in mice without apparent adverse effects. Significantly, metastatic lung tumor also showed the EPR effect, and this conjugate reduced metastatic tumor in the lung almost completely at 30 mg/kg once i.v. (less than one-fifth of the maximum tolerable dose). Although SMA-THP conjugate per se has little cytotoxicity in vitro (1/100 of free drug THP), tumor-targeted accumulation by the EPR effect ensures sufficient drug concentrations in tumor to produce an antitumor effect, whereas toxicity to normal tissues is much less. These findings suggest the potential of SMA-THP conjugate as a highly favorable candidate for anticancer nanomedicine with good stability and tumor-targeting properties in vivo.

[A randomized, double-blind, double-dummy, controlled, multicenter study of entecavir maleate versus entecavir for treatment of HBeAg-negative chronic hepatitis B: results at week 48].

OBJECTIVE: To evaluate the efficacy and safety of entecavir (ETV) maleate versus ETV in Chinese patients with hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB). METHODS: This was a randomized, double-blind, double-dummy, controlled, multicenter study. Patients were randomly assigned to receive 48 weeks of treatment with 0.5 mg/day ETV (group A; n = 26) or 0.5 mg/day ETV maleate (n = 31). Hepatitis B virus (HBV) DNA levels were measured at weeks 12, 24, and 48 by the Roche Cobas Ampliprep/Taqman PCR assay. Adverse events (AE) were recorded. RESULTS: Baseline characteristics were similar between the two groups. At weeks 12, 24, and 48, the mean HBV DNA level had similarly decreased from baseline in both groups (A: by 4.24, 4.61 and 4.88 log10 IU/mL vs. B: 4.01, 4.50 and 4.99 log10 IU/mL, respectively; all P more than 0.05). Patients who achieved undetectable levels of serum HBV DNA (less than 20 IU/mL) at week 48 were similar in the two groups (A: 69.23% vs. B: 80.65%; P more than 0.05). Both groups achieved similar normalization of ALT at week 48 (A: 96.00% vs. B: 83.87%; P more than 0.05). The overall AE incidence was similar for the two groups (A: 22.22% vs. B: 9.38%; P more than 0.05). CONCLUSION: Entecavir maleate and entecavir showed similar efficacy and safety in patients with HBeAg-negative CHB.

Pharmacokinetic comparison of the maleate and free base formulations of LB80380, a novel nucleotide analog, in healthy male volunteers.

OBJECTIVE: LB80380, a dipivoxil ester prodrug of LB80331, is a novel antiviral agent for the treatment of chronic hepatitis B. The aim of this study was to compare the pharmacokinetic differences after single oral administrations of the free base and maleate formulations of LB80380 in healthy male subjects. METHODS: An open-label, single- dose, randomized-sequence, 2-treatment crossover study was conducted in 32 Korean male volunteers. Subjects received either a combination of 60 and 90 mg tablets of the free base LB80380 formulation or a 183 mg (150 mg as a free base) tablet of the maleate LB80380 formulation. Then, after a 14- day washout period, each subject received the other formulation. Plasma and urine concentrations of LB80331 and LB80317 (active metabolites of LB80380) were measured by validated liquid chromatographytandem mass spectrometry assays. A safety assessment, which included vital signs, adverse events, electrocardiograms and clinical laboratory tests, was performed for each subject. RESULTS: A total of 32 healthy subjects was enrolled, and 26 subjects completed the study. Single oral administrations of LB80380 maleate tablets did not result in clinically significant differences in the safety profile compared to the LB80380 free base tablets. The 90% confidence intervals (CIs) for the geometric mean ratios of Cmax and AUClast for LB80331 of the two treatments (maleate versus free base formulation) were 0.986 - 1.1240 and 0.9848 - 1.0533, respectively. The 90% CIs for the geometric mean ratios of Cmax and AUClast for LB80317 were 0.8379 - 0.9696 and 0.7224 - 0.9196. CONCLUSIONS: In healthy male subjects, the 183 mg LB80380 maleate tablet was pharmacokinetically equivalent to the 60 and 90 mg LB80380 free base tablets.

New and emerging cosmetic allergens.

Human skin is exposed to a large variety of cosmetic allergens. Most allergic contact dermatitis occurs after exposure to fragrance, preservatives, and hair dyes. Such reactions can often be occult. As a result, a high index of suspicion is needed in assessing the patient with facial or cosmetic dermatitis. This contribution looks at why such a large number of chemicals are in everyday usage, at how dermatologists monitor trends in allergy to cosmetics, and at a number of new and emerging allergens to consider in the assessment of suspected cosmetic allergy.

Renal cortical albumin gene induction and urinary albumin excretion in response to acute kidney injury.

This study evaluated the potential utility of albuminuria as a "biomarker" of acute kidney injury (AKI) and tested whether AKI induces renal expression of the normally silent albumin gene. Urine albumin concentrations were measured in mice with five different AKI models (maleate, ischemia-reperfusion, rhabdomyolysis, endotoxemia, ureteral obstruction). Albumin gene induction in renal cortex, and in antimycin A-injured cultured proximal tubular cells, was assessed (mRNA levels; RNA polymerase II binding to the albumin gene). Albumin's clinical performance as an AKI biomarker was also tested (29 APACHE II-matched intensive care unit patients with and without AKI). Results were contrasted to those obtained for neutrophil gelatinase-associated lipocalin (NGAL), an established "AKI biomarker" gene. The experimental and clinical assessments indicated albumin's equivalence to NGAL as an AKI biomarker (greater specificity in experimental AKI; slightly better receiver-operating curve in humans). Furthermore, experimental AKI markedly induced the albumin gene (mRNA/RNA polymerase II binding increases; comparable to those seen for NGAL). Albumin gene activation in patients with AKI was suggested by fivefold increases in RNA polymerase II binding to urinary fragments of the albumin gene (vs. AKI controls). Experimental AKI also increased renal cortical mRNA levels for α-fetoprotein (albumin's embryonic equivalent). A correlate in patients was increased urinary α-fetoprotein excretion. We conclude that AKI can unmask, in the kidney, the normally silent renal albumin and α-fetoprotein genes. In addition, the urinary protein data independently indicate that albuminuria, and perhaps α-fetoprotein, have substantial utility as biomarkers of acute tubular injury.

Indacaterol maleate for the treatment of chronic obstructive pulmonary disease.

IMPORTANCE OF THE FIELD: Chronic obstructive pulmonary disease (COPD) is a partially reversible, progressive obstructive disorder. Bronchodilators are the mainstay of treatment since they improve lung function and patient-reported outcomes and reduce acute exacerbations. Long-acting inhaled bronchodilators (at present including the once-daily antimuscarinic tiotropium, and the twice-daily beta(2)-agonists formoterol and salmeterol) are recommended as first-line treatment for patients with persistent symptoms. Indacaterol maleate has been developed as a new once-daily inhaled beta(2)-selective agonist. AREAS COVERED IN THIS REVIEW: This article reviews the published literature on the pharmacologic properties and the Phase II and III trials that have evaluated the safety and efficacy of this new agent. WHAT THE READER WILL GAIN: The reader will obtain an appreciation of the safety and efficacy of indacaterol and the role that it might play in the future management of COPD of varying severity. TAKE HOME MESSAGE: Indacaterol is a new, once-daily beta(2)-agonist with an onset of action within 5 min and a duration of bronchodilation of at least 24 h. In doses of 150 and 300 microg, it has sustained benefits over 6 - 12 months with respect to both bronchodilation and patient-reported outcomes and is well-tolerated with an acceptable safety profile.

Topographic and radiographic profile assessment of dental erosion. Part II: effect of citrus fruit juices on human dentition.

This study sought to monitor changes in the topography, morphology, and radiographic profiles of human permanent teeth that had been exposed to citrus fruit juices. The effect of long-term exposure was monitored for a prolonged duration of 20 weeks according to set criteria. Topographic and morphologic changes were observed at weekly intervals following challenge by test fluids (orange, lemon, and grapefruit juices) and compared with control fluids (acetic acid and water). The qualitative changes in the specimens' topography and the morphology of citrus fruit juices and control fluids are described as a function of time, in specific details. The digitized radiographic images obtained at four-week intervals were analyzed and the changes were assessed. The results indicated that orange juice specimens demonstrated the mildest changes, while lemon juice specimens displayed the most severe damage to the coronal segments of the teeth. This damage manifested as loss of cusp height, cervical enamel, and coronal radius, as well as reduction of enamel cap height. Of the tested and control fluids, lemon juice displayed the most eros ion, followed by acetic acid, grapefruit juice, orange juice, and water, which had no effect. Continued immersion in the four acidic fluids led to varying degrees of enamel loss progression.

Dicaprylyl maleate--an emerging cosmetic allergen.

Dicaprylyl maleate (DCM) has been reported rarely as a cause of allergic contact dermatitis. The objectives of this study were to identify patients from multiple centres with allergy to DCM in cosmetic products confirmed by patch testing and, in addition, to investigate the effect of testing with aged DCM. This is an international multicentre study of 22 patients with 26 reactions to products containing DCM. Patch testing was carried out to ingredients including DCM obtained from the manufacturer. Further testing was carried out with deliberately aged DCM in a sample of patients. 22 patients had clinical and positive patch test reactions at 4 days to a total of 26 cosmetic products containing DCM. 5 patients did not react to DCM prepared by the manufacturer from concurrent factory stock but did have positive reactions to a deliberately aged batch of DCM. DCM is an emerging cosmetic allergen. Testing with aged material yields a greater number of positive results. Co-operation between cosmetics manufacturers and clinicians is important in the identification of new allergens.

Clinical evaluation of a resin composite and bonding agent in Class I and II restorations: 2-year results.

OBJECTIVE: The purpose of this study was to evaluate the clinical performance and longevity of Tetric Ceram and Syntac Sprint restorations in stress-bearing areas performed in general practice. METHOD AND MATERIALS: The light-curing resin composite Tetric Ceram in combination with the bonding material Syntac Sprint were used as restorative materials in three public dental health clinics. All the restorations were done by general practitioners in an ordinary patient pool attending a public health clinic. Before starting, the general practitioners were instructed and trained in performing the restorations according to a standardized clinical procedure, and the evaluations were done according to United States Public Health Service criteria. One hundred forty-eight restorations (27 Class I, 121 Class II) were done in 123 patients. After 2 years, 140 restorations (95%) could be assessed. Color slides and bitewings were taken to supplement the clinical evaluations of color match, marginal discoloration, secondary caries, and marginal adaptation. Wear of the restorations was evaluated according to the Leinfelder method. RESULTS: After 2 years, 7 out of 148 restorations had failed, giving a failure rate of 5% of the tested materials. Five restorations failed due to hypersensitivity, one to secondary caries, and one to fracture. The wear rate was low (mean 37 microm) and did not result in any replacement. CONCLUSION: This 2-year study showed that clinically satisfactory results could be obtained using resin composite Class I and II restorations in stress-bearing areas done in general practice on an ordinary clientele when the clinical procedure is standardized.

Polyelectrolyte complex films derived from polyethyleneoxide-maleic acid copolymer and chitosan: preparation and characterization.

Polyelectrolyte complex films were prepared with polyethyleneoxide-maleic acid copolymer and chitosan using a casting/solvent evaporation method. The films were examined in terms of their IR spectra, surface and cross-section morphologies, cytotoxicity, and swelling behavior at different pH levels. To assess the potential of these films as a biomedical device, the profiles of the release of model drug from the CS/PEOMA films were examined at pH 4.8. The surface morphology of the films was quite smooth and uniform, and the cross-sectional morphology was dense and homogeneous. The swelling behaviors of CS/PEOMA films were found to depend on the pH of the solution as well as on the CS/PEOMA composition. Drug release from different CS/PEOMA films at pH 4.8 was found to be dependent on film composition. The results showed the potential applicability of CS/PEOMA film as a drug delivery vehicle.