Dual inhibition of cyclooxygenase and lipoxygenase enzymes by human cerebrospinal fluid

Thromboxane A₂ (TXA₂) formed in damaged brain tissue and after thromboembolism and subarachnoid haemorrhage is responsible for cerebral vasospasm. In the present study, we examined the effect of human cerebrospinal fluid (CSF) on the production of thromboxane-A₂ (TXA₂) and 12-hydroxy-eicosatetraenoic acid (12-HETE) by human blood platelets. CSF was drawn by lumbar puncture from normal healthy volunteers (n = 17) and samples judged to be normal after routine examination in the clinical laboratories and were used fresh. We found that CSF inhibited the production of TXA₂ and 12-HETE by blood platelets incubated with C¹⁴ labelled arachidonic acid (AA) in a concentration-related manner. Further biochemical analysis using proteolytic enzymes, gel filtration and membrane partition chromatography showed that the inhibitory activity was peptidic in nature and associated with a peptide of low molecular weight (1,400 Da). This study is the first to demonstrate that human CSF contains a dual inhibitor of cyclooxygenase (COX) and lipoxygenase enzymes in CSF.     

Population pharmacokinetics of gliclazide in normal and diabetic rabbits

Gliclazide is a second‐generation sulphonylurea drug widely used in the treatment of type 2 diabetes. However, there is no single report to describe the population pharmacokinetics of gliclazide in animal models. This study was aimed to evaluate the population pharmacokinetics (PK) of gliclazide in normal and alloxan‐induced diabetic rabbits using nonlinear mixed effects modeling. A total of 90 New Zealand white rabbits were administered with three doses (4.13, 8.27 and 16.53 mg/kg b.wt) of gliclazide by an oral route. Blood samples were collected up to 24 hr and the gliclazide concentrations in rabbit were determined using the HPLC method. The non‐compartmental and classical compartmental PK analyses were performed using Phoenix WinNonlin. Population PK analysis of gliclazide was performed using nonlinear mixed‐effects model software NONMEM and Phoenix NLME considering the weight, age, sex, health and dose as covariates. The final population values for clearance (CL), volume of distribution (V) and the absorption rate constant (k_a) were 5270 ml/hr, 55700 ml and 0.708 hr^?1, respectively. The inter‐individual variability in gliclazide CL, V and k_a was 16.3%, 14.9% and 26.5%, respectively. There was no significant difference between NONMEM and Phoenix NLME pharmacokinetic results. The visual predictive check and bootstrap analysis confirmed the predictive ability, model stability and precision of the parameter estimates from this model. This population PK model demonstrated that gliclazide pharmacokinetics is best described by one‐compartment model with first‐order absorption in rabbits. Body weight is a covariate that significantly influences gliclazide kinetic disposition in rabbits.     

Frequency and features of nocturnal enuresis in Pakistani children aged 5 to 16 years based on ICCS criteria: a multi-center cross-sectional study from Karachi,Pakistan

Background

Nocturnal enuresis (NE) is a common symptom in children worldwide. International Children’s Continence Society (ICCS) defines enuresis as either mono-symptomatic, NE with lower urinary tract symptoms and NE with co-morbid conditions. The objectives of this study were to determine the frequencies and types of NE and associated symptoms and conditions in children aged 5 to 16?years based on ICCS criteria.

Methods

A multi-center cross sectional study was conducted between November 2012 and December 2013 in the primary care clinics of four hospitals in Karachi. Children aged five to fifteen years were included through consecutive sampling. Informed consent was obtained from the parents and a pre-coded semi-structured questionnaire was used to obtain the information. Data was entered on SPSS version 20.0 and multivariable logistic regression analysis was used for data analysis.

Results

Out of 429 children aged between five and sixteen years, 243(56.9%) were boys and the remaining 186(43.1%) were girls. One hundred and eighty three children (43%) had nocturnal enuresis (NE). Forty four (10.3%), had mono-symptomatic NE, 57(31.1%) had associated lower urinary tract symptoms (NE-LUTS), whereas 30 (16.3%) had NE with a co-morbid condition. Fifty two (28.4%) NE’s had at least one of both LUTS and a co-morbid condition. Out of the 246(57%) non-enuretic’s, 31(12.6%) had a LUTS, 95(38.6%) had a co-morbid condition and 57(23.2%) had at least one of both LUTS and a co-morbid condition. The remaining 63 (25.6%) were symptom free. Increased voiding frequency, urgency, dysuria, suprapubic pain and daytime incontinence were the LUTS significantly associated with NE. Co-morbid conditions significantly associated with NE included constipation, congenital defects, developmental delay, and learning and sleep problems.

Conclusion

Although NE can be an only symptom, it is often associated with lower urinary tract symptoms like dysuria, urgency, suprapubic pain, and daytime incontinence. Children presenting with NE often have co-morbid conditions like constipation, urinary tract infection, sleep disorders, and developmental delay. Many children presenting with these conditions as the primary complaint may also have NE. It should be addressed as unrecognized and untreated NE can cause additional morbidity and distress.

     

Antimicrobial and antileishmanial activities of hypocrellins A and B

Hypocrellins A and B were evaluated for in vitro antimicrobial and antileishmanial activities. Hypocrellin A exhibited promising activity against Candida albicans and moderate activity against Staphylococcus aureus, methicillin-resistant S. aureus, Pseudomonas aeruginosa, and Mycobacterium intracellulare. Hypocrellin B showed weak antimicrobial activities. Hypocrellin A exhibited potent antileishmanial activity, while hypocrellin B was only moderately active. These results of promising antifungal and antileishmanial activity of hypocrellin A may be useful for further structure-activity relationship and in vivo studies.