Allopurinol is the most commonly used drug for the treatment of hyperuricemia in people, and in view of the risks of fatal hypersensitivity in patients with renal dysfunction, doses based on the glomerular filtration rate are proposed. In veterinary medicine, allopurinol is used in the treatment of canine leishmaniasis (CanL) caused by Leishmania infantum owing to the drug action of inhibiting the parasite’s RNA synthesis. However, renal dysfunction frequently ensues from disease progression in dogs. The purpose of the present study was to standardize and validate a sensitive high-performance liquid chromatography-mass spectrometric (HPLC-MS/MS) method to determine the concentration of allopurinol and its active metabolite oxypurinol in canine urine for clinical pharmacokinetic investigation. Urine samples of eleven (11) dogs with naturally occurring CanL and in the maintenance phase of the treatment with alopurinol were used. For the chromatographic analysis of urine, the mobile phase consisted of a solution of 0.1 % formic acid (88 %) in 10 mM ammonium acetate. Separation of allopurinol and oxypurinol occurred in a flow of 0.8 mL/min on a C8 reverse phase column 5 μm, and acyclovir was the internal standard. selleck chemicals llc The HPLC-MS/MS method was validated by reaching the limits of detection and quantification, reproducibility and linearity. The lower limit of quantification achieved by the method was 10 μg/mL for both allopurinol and oxypurinol. Calibration curves were prepared in blank urine added with allopurinol at concentrations of 10-1000 μg/mL, and oxypurinol at 10-200 μg/mL. Coefficients of variation of less than 15 % between intracurrent and intercurrent accuracy values were observed for both allopurinol and oxypurinol. Urine test samples remained stable after being subjected to freeze-thaw cycles and remaining at room temperature for 4 h. The method proved to be adequate to quantify allopurinol and oxypurinol in urine samples from dogs under treatment. A novel analytical method is presented for 12 target pharmaceutical and personal care products (PPCPs), belonging to different classes like antibiotics, non-steroid anti-inflammatory drugs, parabens, UV-filters, plasticizer, and antibacterials. The method development comprises of solid-phase extraction (SPE) with lipophilic-hydrophilic material balanced Oasis HLB cartridge, followed by reverse-phase liquid chromatography interfaced to linear ion trap tandem mass spectrometry (LC-MS/MS) with electrospray ionization. Chromatographic separation was achieved with a gradient elution of 25 min run time using 5 mM ammonium acetate buffer with pH adjustment using acetic acid. In addition, cost effective organic solvent with buffer used together as the mobile phase with Chromatopak C18 column (150 mm × 4 mm, 5-μm,) in negative ionization mode. Recoveries ranged from 61.74 % to 119.89 % for most of the compounds. Matrix-matched calibration curves were used for counterbalancing the matrix effects for all the analytes, ast time to determine target analytes in surface water samples collected from Arkavathi river flowing across southern India’s Bengaluru city. PURPOSE To investigate the diagnostic performance of urothelial phase (UP) CT and identify the appropriate imaging criteria for assessment of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) in patients with bladder cancer. METHOD Seventy-three patients who underwent NAC and subsequent radical or partial cystectomy between January 2017 and July 2019 were retrospectively analyzed. UP CT findings after NAC were divided into five grades as follows grade 1, no wall thickening or inner-layer enhancement; grade 2, thin inner-layer enhancement without wall thickening; grade 3, inner-layer enhancement with low-attenuation wall thickening; grade 4, wall thickening with enhancement; and grade 5, nodular enhancement or enhanced soft tissue. Two radiologists independently evaluated these grades on the post-chemotherapy CT. The area under the ROC curve (AUC) was used to evaluate diagnostic performance for pCR. Inter-reader agreement was assessed using the κ coefficient. RESULTS Twenty-seven patients (37 %) were confirmed with pCR. The AUCs for the assessment of pCR on UP CT were 0.85-0.86 for the two readers. Using absent or thin inner-layer enhancement as features to predict pCR, the sensitivity, specificity, positive predictive value, and negative predictive value were 74.1-81.5 %, 80.4-84.8 %, 71.0-74.1 %, and 84.8-88.1 % for both readers. The inter-reader agreement for grades ≤2 was almost perfect (κ = 0.83). CONCLUSIONS Absent or thin inner-layer enhancement on UP CT demonstrated high diagnostic performance and high inter-reader agreement for assessment of pCR after neoadjuvant chemotherapy in bladder cancer, and evaluation of this feature could improve the predictive ability of preoperative imaging for assessing pCR. LOV2 (Light-Oxygen-Voltage) domain from Avena sativa phototropin 1 (AsLOV2) belongs to the superfamily of PAS (Per-Arnt-Sim) domains, members of which function as signaling sensors. AsLOV2 undergoes a conformational change upon blue-light absorption by its FMN cofactor. AsLOV2 wild type (wt) is intensively studied as a photo-switchable element in conjugation with various proteins. On the other hand, its variant AsLOV2 with replaced cysteinyl residue C450, which is critical for the forming a covalent adduct with FMN upon irradiation, forms a precursor for some recently developed genetically encoded photosensitizers. In the presented work, we investigated conformational properties of AsLOV2 wt and its variant C450A by circular dichroism, tryptophan and FMN fluorescence, and differential scanning calorimetry in dependence on pH and temperature. We show that both variants are similarly sensitive towards pH of solvent. On the other hand, the mutation C450A leads to a more stable AsLOV2 variant in comparison with the wild type. Thermal transitions of the AsLOV2 proteins monitored by circular dichroism indicate the presence of significant residual structure in thermally-denatured states of both proteins in the pH range from 4 to 9. Both pH- and thermal- transitions of AsLOV2 are accompanied by FMN leaching to solvent. Higher stability, reversibility of thermal transitions, and efficiency of FMN rebinding in the case of C450A variant suggest that the cofactor release may be modulated by suitable mutations in combination with a suitable physicochemical perturbation. These findings can have implications for a design of genetically encoded photosensitizers.