Detection of dynorphin 1-17 biotransformation fragments in human nasal polyps by UPLC-QTOF-MS.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a persistent inflammation of the sinonasal mucosa. CRSwNP treatments are associated with inconsistent efficacy and recurrence of symptoms. Dynorphin 1-17 (DYN 1-17) and its fragments have been shown to modulate the immune response in various inflammatory conditions. This study aimed to investigate the effect of different pH and degrees of inflammation on DYN 1-17 metabolism in human CRSwNP tissues. DYN 1-17 was incubated with grade 3 and grade 4 inflamed tissues of CRSwNP patients at pH 5.5 and pH 7.4 over a range of incubation periods. The resulting fragments were identified using an ultra-performance liquid chromatography (UPLC) system coupled to quadrupole-time of flight (QTOF) mass spectrometry based on their accurate mass. The rate of DYN 1-17 fragmentation was slower at pH 5.5 in comparison to pH 7.4. The extent and rate of metabolism of DYN 1-17 were much lower in grade 3 inflamed tissue (31-32 fragments) than in grade 4 (34-41 fragments). N-Terminal fragments (DYN 1-15, 1-11, 1-10, and 1-6) were metabolized slower at pH 5.5 as compared to pH 7.4. DYN 1-12, 1-8, 2-10, 4-10, 5-10, and 8-14 were only observed under the inflammatory pH while DYN 5-17 and 6-17 were only identified upon incubation with grade 4 CRSwNP tissues. DYN 1-17 metabolism was significantly affected by the pH level and the severity of the inflammation of CRSwNP tissues, indicating the potential roles of DYN 1-17 and its fragments in modulating the inflammatory response and their avenue as therapeutics in future studies.

Time-Dissociated Pharmacokinetic Pharmacodynamic Model of Cyclosporine Among Malaysian Renal Transplant Recipients.

BACKGROUND: Cyclosporine is an essential component of many immunosuppressive regimens. However, its pharmacokinetic and pharmacodynamic (PKPD) modeling has not been widely investigated. This study aims to develop a time-dissociated PKPD model of cyclosporine in renal transplant patients. METHODS: Medical records of renal transplant patients at Penang General Hospital were retrospectively analyzed. A time-dissociated PKPD model with covariate effects was developed using NONMEM to evaluate renal graft function response, quantified as estimated glomerular filtration rate (eGFR), toward the cyclosporine cumulative exposure (area under the concentration-time curve). The final model was integrated into a tool to predict the potential outcome. Individual eGFR predictions were evaluated based on the clinical response recorded as acute rejection/nephrotoxicity events. RESULTS: A total of 1256 eGFR readings with 2473 drug concentrations were obtained from 107 renal transplant patients receiving cyclosporine. An Emax drug effect with a linear drug toxicity model best described the data. The baseline renal graft level (E0), maximum effect (Emax), area under the concentration-time curve achieving 50% of the maximum effect, and nephrotoxicity slope were estimated as 12.9 mL·min-1·1.73 m-2, 50.7 mL·min-1·1.73 m-2, 1740 ng·h·mL-1, and 0.00033, respectively. The hemoglobin level was identified as a significant covariate affecting the E0. The model discerned acute rejection from nephrotoxicity in 19/24 cases. CONCLUSIONS: A time-dissociated PKPD model successfully described a large number of observations and was used to develop an online tool to predict renal graft response. This may help discern early rejection from nephrotoxicity, especially for patients unwilling to undergo a biopsy or those waiting for biopsy results.

Dynorphin 1-17 biotransformation peptides: properties, challenges and solutions for future therapeutics development.

It is well established that endogenously produced dynorphin 1-17 (DYN 1-17) is susceptible to enzymatic degradation, producing a variety of unique fragments in different tissue matrices and disease pathologies. DYN 1-17 and its major biotransformation fragments have significant roles in neurological and inflammatory disorders upon interacting with opioid and non-opioid receptors at both central and peripheral levels, thus highlighting their potential as drug candidates. Nevertheless, their development as promising therapeutics is challenged by several issues. This review aims to provide the latest and comprehensive updates on DYN 1-17 biotransformed peptides, including their pharmacological roles, pharmacokinetic studies and relevant clinical trials. Challenges in their development as potential therapeutics and proposed solutions to overcome these limitations are also discussed.

This is a summary of published articles on the important roles of dynorphin 1-17 and its fragments in several disease pathologies, including neurological and inflammatory disorders. Dynorphin 1-17, which consists of 17 amino acids, is a substance produced in the human body that is easily degraded by the body's enzymes, producing a shorter chain of amino acids. For the past few decades, researchers have attempted to utilize these substances to treat the above-mentioned conditions. However, upon introduction, these substances are rapidly degraded by the enzymes, which hinder the molecules from reaching the site of action. Therefore, many studies have focused on addressing the degradation issue in order to benefit from the important role of dynorphin 1-17 and its fragments in treating respective diseases. Previous researchers have attempted structural modification of these substances by either changing the terminals of the amino acid chains or attaching them to other agents to increase the resistance of dynorphin 1-17 and its fragments toward enzymatic breakage. These substances were also incorporated into nano-sized delivery systems, which have been shown to protect the molecules while improving their delivery to different parts of the body. These results showed that the structurally modified dynorphin 1-17 and its fragments and their nano-sized delivery system could improve the stability of the molecules and allow them to be used to treat many conditions.

Biocompatible magnesium-doped biphasic calcium phosphate for bone regeneration.

Autologous bone grafting remains the gold standard for almost all bone void-filling orthopedic surgery. However, autologous bone grafting has several limitations, thus scientists are trying to identify an ideal synthetic material as an alternative bone graft substitute. Magnesium-doped biphasic calcium phosphate (Mg-BCP) has recently been in the spotlight and is considered to be a potential bone substitute. The Mg-BCP is a mixture of two bioceramics, that is, hydroxyapatite (HA) and ß-tricalcium phosphate (ß-TCP), doped with Mg2+ , and can be synthesized through chemical wet-precipitation, sol-gel, single diffusion gel, and solid state reactions. Regardless of the synthesis routes, it is found that the Mg2+ preferentially accommodates in ß-TCP lattice instead of the HA lattice. The addition of Mg2+ to BCP leads to desirable physicochemical properties and is found to enhance the apatite-forming ability as compared to pristine BCP. In vitro results suggest that the Mg-BCP is bioactive and not toxic to cells. Implantation of Mg-BCP in in vivo models further affirmed its biocompatibility and efficacy as a bone substitute. However, like the other bioceramics, the optimum physicochemical properties of the Mg-BCP scaffold have yet to be determined. Further investigations are required regarding Mg-BCP applications in bone tissue engineering.

Risk factors for mortality among COVID-19 patients.

AIMS: COVID-19 is a current global pandemic. However, comprehensive global data analyses for its mortality risk factors are lacking. The current investigation aimed to assess the predictors of death among COVID-19 patients from worldwide open access data. METHODS: A total of 828 confirmed cases of COVID-19 with definite outcomes were retrospectively identified from open access individual-level worldwide data. Univariate followed by multivariable regression analysis were used to evaluate the association between potential risk factors and mortality. RESULTS: Majority of the patients were males 59.1% located in Asia 69.3%. Based on the data, older age (adjusted odds ratio (aOR), 1.079; 95% confidence intervals (95% CI), 1.064-1.095 per year increase), males (aOR, 1.607; 95% CI, 1.002-2.576), patients with hypertension (aOR, 3.576; 95% CI, 1.694-7.548), diabetes mellitus (aOR, 12.234; 95% CI, 4.126-36.272), and patients located in America (aOR, 7.441; 95% CI, 3.546-15.617) were identified as the risk factors of mortality among COVID-19 patients. CONCLUSIONS: Males, advanced age, hypertension patients, diabetes mellitus patients, and patients located in America were the independent risk factors of death among COVID-19 patients. Extra attention is required to be given to these factors and additional studies on the underlying mechanisms of these effects.

Population Pharmacokinetic Modeling of Cyclosporine Among Malaysian Renal Transplant Patients: An Evaluation of Methods to Handle Missing Doses in Conventional Drug-Monitoring Data.

Cyclosporine is a primary drug in transplant immunosuppression regimens. It has a narrow therapeutic index and variable pharmacokinetic behavior. This study aimed to develop a population pharmacokinetic model of cyclosporine in Malaysian renal transplant recipients as well as to evaluate the performances of different methodsfor handling missing doses. A total of 2804 concentrationts predose and 2 hours after doses were collected retrospectively from 113 renal transplant patients on cyclosporine in Penang General Hospital. Model structure and pharmacokinetic parameters were estimated using nonlinear mixed-effects modeling software. Missing doses were handled using different methods to evaluate their performance. Covariate analysis was performed using stepwise forward addition (P < .05) followed by backward elimination (P < .001). Prediction-corrected visual predictive check and sampling-importance resampling methods were used to validate the final model. A 1-compartment model with first-order absorption and elimination best fitted the data. All methods to handle missing doses performed well with the missing dose method being superior to other methods and thus was applied in the final model. Cyclosporine clearance (CL/F) was estimated as 15.1 L/h, and volume of distribution (V/F) was 108 L. Postoperative time, sex, and calcium channel blockers were identified as significant covariates on CL/F, whereas sex and cholesterol level were identified as significant covariates on V/F. This is the first population pharmacokinetic model developed in Malaysian renal transplant patients using a large sample with an evaluation of different methods to handle missing doses in less informative conventional therapeutic drug-monitoring data.