In silico and in vitro evaluation of two novel oximes (K378 and K727) in comparison to K-27 and pralidoxime against paraoxon-ethyl intoxication

Organophosphate (OP) poisoning is a major global health issue; while compounds from this group have been used intensively over the last century, an effective antidote is still lacking. Oxime-type acetylcholinesterase (AChE) reactivators are used to reactivate the OP inhibited AChE. Pralidoxime is the only US Food and Drug Administration approved oxime for therapeutic use but its efficacy has been disappointing. Two novel oximes (K378 and K727) were investigated in silico and in vitro and compared with an experimental oxime (kamiloxime; K-27) and pralidoxime. In silico the molecular interactions between AChE and oximes were examined and binding energies were assessed. LogP (predicted log of the octanol/water partition coefficient) was estimated. In vitro the intrinsic ability of the oximes to inhibit AChE (IC₅₀) and their reactivation potency (R₅₀) when used in paraoxon inhibited human RBC-AChE was determined. Molecular docking revealed that K378 and K727 bind to the peripheral site(s) with high binding energies in contrast to the central binding of K-27 and pralidoxime. LogP values indicating that the novel compounds are significantly less hydrophilic than K-27 or pralidoxime. IC₅₀ of K378 and K727 were comparable (0.9 and 1?µM, respectively) but orders of magnitude lower than comparators. R₅₀ values revealed their inability to reactivate paraoxon inhibited AChE. It is concluded that the novel oximes K378 and K727 are unlikely to be clinically useful. The in silico and in vitro studies described allow avoidance of unnecessary in vivo animal work and contribute to the reduction of laboratory animal use.     

Gastroprotective effects of amifostine in rats treated by T-2 toxin

Cytoprotector amifostine (AMI) was given in a dose of 50, 100 or 150?mg/kg ip in rats treated with several highly toxic doses of T-2 toxin. The best survival rate (24?h and 7?days after treatment) was obtained with AMI50 (50?mg/kg ip). After T-2 intoxication, a peak in the mean number of gastric lesions (petechiae and ulcerations) was reached on the third day (26.40?±?6.24). Administration of AMI50 reduced, almost completely, the total number of gastric lesions in rats acutely poisoned by 0.5 LD₅₀ T-2 (1.5?mg/kg sc), starting with day 1 after intoxication (5.60?±?3.42).     

Realistic Food-Based Approaches Alone May Not Ensure Dietary Adequacy for Women and Young Children in South-East Asia

Objectives Micronutrient deficiencies, in southeast Asia (SE Asia), remain a public health challenge. We evaluated whether promoting the consumption of locally available nutritious foods, which is a low-risk micronutrient intervention, alone can ensure dietary adequacy, for women of reproductive age and 6–23 m old children. Methods Representative dietary data from Cambodia, Indonesia, Lao PDR, Thailand and Vietnam were analysed using linear programming analysis to identify nutrients that are likely low in personal food environments (problem nutrients), and to formulate food-based recommendations (FBRs) for three to six target populations per country. Results The number of problem nutrients ranged from zero for 12–23 m olds in Indonesia, Thailand and Vietnam to six for pregnant women in Cambodia. The FBRs selected for each target population, if adopted, would ensure a low percentage of the population was at risk of inadequate intakes for five to ten micronutrients, depending on the country and target population. Of the 11 micronutrients modelled, requirements for iron, calcium and folate were most difficult to meet (≥ 10 of the 24 target populations), using FBRs alone. The number of individual FBRs selected per set, for each target population, ranged from three to eight; and often included meat, fish or eggs, liver/organ meats, vegetables and fruits. Conclusions for practice Intervention strategies need to increase access to nutritious foods, including products fortified with micronutrients, in SE Asia, when aiming to ensure dietary adequacy for most individuals in the population.

     

The New Acetylcholinesterase Inhibitors PC‐37 and PC‐48 (7‐Methoxytacrine‐Donepezil‐Like Compounds): Characterization of Their Metabolites in Human Liver Microsomes,Pharmacokinetics and In Vivo Formation of the Major Metabolites in Rats

The objective of this study was to elucidate the pharmacokinetics and metabolite formation of newly developed non‐selective AChE/BChE 7‐MEOTA‐donepezil‐like inhibitors for potential therapeutic use in Alzheimer's disease (AD) patients. The chemical structures of metabolites were defined during incubation with human liver microsomes, and subsequently, the metabolization was verified in in vivo study. In vitro metabolic profiling revealed the formation of nine major metabolites in the case of PC‐37 and eight metabolites of PC‐48. Hydroxylation and the enzymatic hydrolysis of bonds close to the piperazine ring appeared to be the principal metabolic pathways in vitro. Of these metabolites, M1–M7 of PC‐37 and M1–M6 of PC‐48 were confirmed under in vivo conditions. Pilot pharmacokinetic experiments in rats were focused on the absorption, distribution and elimination of these compounds. Absorption after i.m. application was relatively fast; the bioavailability expressed as AUC_total was 28179 ± 4691 min.ng/mL for PC‐37 and 23374 ± 4045 min.ng/mL for PC‐48. Both compounds showed ability to target the central nervous system, with brain concentrations exceeding those in plasma. The maximal brain concentrations are approximately two times higher than the plasma concentrations. The relatively high brain concentrations persisted throughout the experiment until 24 hr after application. Elimination via the kidneys (urine) significantly exceeded elimination via the liver (bile). All these characteristics are crucial for new candidates intended for AD treatment. The principle metabolic pathways that were verified in the in vivo study do not show any evidence for formation of extremely toxic metabolites, but this needs to be confirmed by further studies.     

Multicenter Validation of the Revised Assessment of Bleeding and Transfusion (RABT) Score for Predicting Massive Transfusion

World Journal of Surgery - Massive transfusion (MT) is a lifesaving treatment for hemorrhaging patients. Predicting the need for MT is crucial to improve survival. The aim of our study was to...     

Inflammatory Markers and Risk of Hip Fracture in Older White Women: The Study of Osteoporotic Fractures

Hip fractures are the most devastating consequence of osteoporosis and impact 1 in 6 white women leading to a two‐ to threefold increased mortality risk in the first year. Despite evidence of inflammatory markers in the pathogenesis of osteoporosis, few studies have examined their effect on hip fracture. To determine if high levels of inflammation increase hip fracture risk and to explore mediation pathways, a case‐cohort design nested in a cohort of 4709 white women from the Study of Osteoporotic Fractures was used. A random sample of 1171 women was selected as the subcohort (mean age 80.1 ± 4.2 years) plus the first 300 women with incident hip fracture. Inflammatory markers interleukin‐6 (IL‐6) and soluble receptors (SR) for IL‐6 (IL‐6 SR) and tumor necrosis factor (TNF SR1 and TNF SR2) were measured, and participants were followed for a median (interquartile range) of 6.3 (3.7, 6.9) years. In multivariable models, the hazard ratio (HR) of hip fracture for women in the highest inflammatory marker level (quartile 4) was 1.64 (95% confidence interval [CI], 1.09–2.48, p trend = 0.03) for IL‐6 and 2.05 (95% CI, 1.35–3.12, p trend <0.01) for TNF SR1 when compared with women in the lowest level (quartile 1). Among women with 2 and 3–4 inflammatory markers in the highest quartile, the HR of hip fracture was 1.51 (95% CI, 1.07–2.14) and 1.42 (95% CI, 0.87–2.31) compared with women with zero to one marker(s) in the highest quartile (p trend = 0.03). After individually adjusting for seven potential mediators, cystatin‐C (a biomarker of renal function) and bone mineral density (BMD) attenuated HRs among women with the highest inflammatory burden by 64% and 50%, respectively, suggesting a potential mediating role. Older white women with high inflammatory burden are at increased risk of hip fracture in part due to poor renal function and low BMD. © 2014 American Society for Bone and Mineral Research.     

Comparing 3-T multiparametric MRI and the Partin tables to predict organ-confined prostate cancer after radical prostatectomy

ObjectivesThe purpose of our study was to test our hypothesis that multiparametric magnetic resonance imaging (mpMRI) may have a higher prognostic accuracy than the Partin tables in predicting organ-confined (OC) prostate cancer and extracapsular extension (ECE) after radical prostatectomy (RP).Methods and materialsAfter institutional review board approval, we retrospectively reviewed 60 patients who underwent 3-T mpMRI before RP. mpMRI was used to assess clinical stage and the updated version of the Partin tables was used to calculate the probability of each patient to harbor OC disease. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of mpMRI in detecting OC and ECE were calculated. Logistic regression models predicting OC pathology were created using either clinical stage at mpMRI or Partin tables probability. The area under the curve was used to calculate the predictive accuracy of each model.ResultsMedian prostate-specific antigen level at diagnosis was 5 ng/ml (range: 4.1–6.7 ng/ml). Overall, 52 (86.7%) men had cT1 disease, 7 (11.7%) had cT2a/b, and 1 (1.6%) had cT3b at digital rectal examination. Biopsy Gleason score was 6, 3+4 = 7, 4+3 = 7, 8, and 9 to 10 in 28 (46.7%), 15 (25%), 3 (5%), 10 (16.7%), and 4 (6.6%) patients, respectively. At mpMRI, clinical stage was defined as cT2a/b, cT2c, cT3a, and cT3b in 11 (18.3%), 23 (38.3%), 21 (35%), and 5 (8.4%) patients, respectively. At final pathology, 38 men (63.3%) had OC disease, whereas 18 (30%) had ECE and 4 (6.7%) had seminal vesicle invasion.The sensitivity, specificity, PPV, and NPV of mpMRI in detecting OC disease were 81.6%, 86.4%, 91.2%, and 73.1%, respectively, whereas in detecting ECE were 77.8%, 83.4%, 66.7%, and 89.7%, respectively. At logistic regression, both the Partin tables–derived probability and the mpMRI clinical staging were significantly associated with OC disease (all P<0.01). The area under the curves of the model built using the Partin tables and that of the mpMRI model were 0.62 and 0.82, respectively (P = 0.04).ConclusionsThe predictive accuracy of mpMRI in predicting OC disease on pathological analysis is significantly greater than that of the Partin tables. mpMRI had a high PPV (91.2%) when predicting OC disease and a high NPV (89.7%) with regard to ECE. mpMRI should be considered when planning prostate cancer treatment in addition to readily available clinical parameters.     

Co-culture with NK-92MI cells enhanced the anti-cancer effect of bee venom on NSCLC cells by inactivation of NF-κB

In the present study we experimented on a multimodal therapeutic approach, such as combining chemotherapy agent (Bee venom) with cellular (NK-92MI) immunotherapy. Previously bee venom has been found to show anti-cancer effect in various cancer cell lines. In lung cancer cells bee venom showed an IC⁵⁰ value of 3 μg/ml in both cell lines. The co-culture of NK-92MI cell lines with lung cancer cells also show a decrease in viability upto 50 % at 48 h time point. Hence we used bee venom treated NK-92MI cells to co-culture with NSCLC cells and found that there is a further decrease in cell viability upto 70 and 75 % in A549 and NCI-H460 cell lines respectively. We further investigated the expression of various apoptotic and anti-apoptotic proteins and found that Bax, cleaved caspase-3 and -8 were increasing where as Bcl-2 and cIAP-2 was decreasing. The expression of various death receptor proteins like DR3, DR6 and Fas was also increasing. Concomitantly the expression of various death receptor ligands (TNFalpha, Apo3L and FasL) was also increasing of NK-92MI cells after co-culture. Further the DNA binding activity and luciferase activity of NF-κB was also inhibited after co-culture with bee venom treated NK-92MI cell lines. The knock down of death receptors with si-RNA has reversed the decrease in cell viability and NF-κB activity after co-culture with bee venom treated NK-92MI cells. Thus this new approach can enhance the anti-cancer effect of bee venom at a much lower concentration.     

Prophylactic administration of non‐organophosphate cholinesterase inhibitors before acute exposure to organophosphates: assessment using terbufos sulfone

Poisoning with organophosphorus compounds (OPCs) poses a serious threat worldwide. OPC‐induced mortality can be significantly reduced by prophylactic administration of reversible acetylcholinesterase (AChE) inhibitors. The only American Food and Drug Administration (FDA)‐approved substance for such pre‐treatment (to soman exposure) is presently pyridostigmine, although its efficacy is controversial. In search for more efficacious and broad‐spectrum alternatives, we have assessed in vivo the mortality‐reducing efficacy of a group of five compounds with known AChE inhibitory activity (pyridostigmine, physostigmine, ranitidine, tacrine and K‐27), when given in equitoxic dosage (25% of LD₀₁) 30 min before exposure to the OPC terbufos sulfone. Protection was quantified in rats by determining the relative risk of death (RR) using Cox analysis, with RR = 1 for animals given only terbufos sulfone, but no pre‐treatment. All tested AChE inhibitors reduced terbufos sulfone‐induced mortality significantly (p ≤ 0.05) as compared with the non‐treatment group (RR = 1: terbufos sulfone only). Best in vivo protection from terbufos sulfone‐induced mortality was achieved, when K‐27 was given before terbufos sulfone exposure (RR = 0.06), which was significantly (P ≤ 0.05) superior to the pre‐treatment with all other tested compounds, for example tacrine (RR = 0.21), pyridostigmine (RR = 0.28), physostigmine (RR = 0.29) and ranitidine (RR = 0.33). The differences in efficacy between tacrine, pyridostigmine, physostigmine and ranitidine were not statistically significant. Prophylactic administration of an oxime (such as K‐27) in case of imminent OPC exposure may be a viable option. Copyright © 2013 John Wiley & Sons, Ltd.     

Oxidative stress-mediated cytotoxicity and metabolism of T-2 toxin and deoxynivalenol in animals and humans: an update

Trichothecenes are a large family of structurally related toxins mainly produced by Fusarium genus. Among the trichothecenes, T-2 toxin and deoxynivalenol (DON) cause the most concern due to their wide distribution and highly toxic nature. Trichothecenes are known for their inhibitory effect on eukaryotic protein synthesis, and oxidative stress is one of their most important underlying toxic mechanisms. They are able to generate free radicals, including reactive oxygen species, which induce lipid peroxidation leading to changes in membrane integrity, cellular redox signaling, and in the antioxidant status of the cells. The mitogen-activated protein kinases signaling pathway is induced by oxidative stress, which also induces caspase-mediated cellular apoptosis pathways. Several new metabolites and novel metabolic pathways of T-2 toxin have been discovered very recently. In human cell lines, HT-2 and neosolaniol (NEO) are the major metabolites of T-2 toxin. Hydroxylation on C-7 and C-9 are two novel metabolic pathways of T-2 toxin in rats. The metabolizing enzymes CYP3A22, CYP3A29, and CYP3A46 in pigs, as well as the enzymes CYP1A5 and CYP3A37 in chickens, are able to catalyze T-2 toxin and HT-2 toxin to form the C-3′–OH metabolites. Similarly to carboxylesterase, CYP3A29 possesses the hydrolytic ability in pigs to convert T-2 toxin to NEO. T-2 toxin is able to down- or upregulate cytochrome P-450 enzymes in different species. The metabolism of DON in humans is region-dependent. Free DON and DON-glucuronide are considered to be the biomarkers for humans. The masked mycotoxin DON-3-β-d-glucoside can be hydrolyzed to free DON in the body. This review will provide useful information on the progress of oxidative stress as well as on the metabolism and the metabolizing enzymes of T-2 toxin and DON. Moreover, the literature will throw light on the blind spots of metabolism and toxicological studies in trichothecenes that have to be explored in the future.