Bactericidal activity of daptomycin versus vancomycin in the presence of human albumin against vancomycin-susceptible but tolerant methicillin-resistant Staphylococcus aureus (MRSA) with daptomycin minimum inhibitory concentrations of 1–2 μg/mL

This study explored the influence of vancomycin tolerance and protein binding on the bactericidal activity of vancomycin versus daptomycin (protein binding 36.9% vs. 91.7%, respectively) against four vancomycin-tolerant methicillin-resistant Staphylococcus aureus (MRSA) [minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) = 0.5/16, 1/32, 2/32 and 1/32 μg/mL for vancomycin and 1/1, 1/2, 2/2 and 2/4 μg/mL for daptomycin]. Killing curves were performed with vancomycin/daptomycin concentrations equal to serum peak concentrations (C_max) (65.70/98.60 μg/mL) and trough concentrations (C_min) (7.90/9.13 μg/mL) in the presence and absence of a physiological human albumin concentration (4 g/dL), controlled with curves with the theoretical free drug fraction of vancomycin/daptomycin C_max (41.45/8.18 μg/mL) and C_min (4.98/0.76 μg/mL). Vancomycin C_max and C_min concentrations, regardless of the media, showed a bacteriostatic profile not reaching a reduction of 99% or 99.9% of the initial inocula during the 24-h experimental time period. Daptomycin antibacterial profiles significantly differed when testing C_max and C_min. C_max was rapidly bactericidal (≤4 h) with >5 log₁₀ reduction in the initial inocula for all strains, regardless of the presence or not of albumin or the use of concentrations similar to free C_max. C_min exhibited similar final colony counts at 0 h and 24 h in curves with albumin, but with >3 log colony-forming units (CFU)/mL reduction at ≤4 h for strains with an MIC of 1 μg/mL and ca. 2 log CFU/mL reduction at ≤6 h for strains with an MIC of 2 μg/mL. This activity was significantly higher than the activity of the free C_min fraction. The results of this study reinforce the idea that pharmacodynamics using concentrations calculated using reported protein binding are unreliable. Daptomycin exhibited rapid antibacterial activity against vancomycin-tolerant MRSA isolates even against those with high daptomycin MICs in the presence of physiological albumin concentrations.     

Skin Laser Treatments Enhancing Transdermal Delivery of ALA

Drug delivery across skin has been limited due to barrier properties of the skin, especially those of the stratum corneum (SC). Use of the laser radiation has been suggested for the controlled removal of the SC. The purpose of this study was to study in vitro the influence of infrared radiation from the erbium:yttrium–aluminum–garnet (Er:YAG) laser (λ = 2940 nm), and visible from the 2nd harmonic of a neodymium:yttrium–aluminum–garnet (Nd:YAG) laser (λ = 532 nm) on transdermal delivery of 5-aminolevulinic acid (ALA). Pinna skin of the inner side of rabbit ear was used for skin permeation. The light sources were an Er:YAG laser (Key III Plus KaVo) and a Q-switched Nd:YAG laser (Lotis TII SL-2132). Permeation study, morphological and structural skin examination by histology and differential scanning calorimetry (DSC) were carried out. Permeation profiles and histological observations obtained after irradiation with infrared and visible laser radiation differed due to different biophysical effects on irradiated skin. Wavelength of 2940 nm required lower energy contribution to produce the same level of permeation than visible radiation at 532 nm. Structural analysis by DSC shows a selective impact on the lipidic structure. Laser pretreatment enhanced the delivery of ALA trough the skin by SC ablation.     

The effects of a brief mindfulness exercise on state mindfulness and affective outcomes among adult daily smokers

Brief, single session mindfulness training has been shown to reduce emotional distress, craving, and withdrawal symptoms among smokers when they are nicotine-deprived. However, no research has examined the efficacy of brief mindfulness training for non-nicotine-deprived smokers, or explored its effects on smokers' ability to tolerate emotional distress. Smokers progress differently through various stages as they attempt to change their smoking behavior and evidence-based strategies are needed for smokers at all levels of nicotine deprivation. Therefore, the purpose of the current study was to examine the effects of a brief mindfulness exercise on state mindfulness, distress, distress tolerance, and smoking urges following a distressing laboratory task among 86 non-nicotine-deprived adult daily smokers (M_age = 46 years, 55% male, 74% African-American) who completed behavioral tasks and self-report measures before and after randomization to a 10-min mindfulness or control exercise. As hypothesized, the mindfulness exercise significantly increased state mindfulness [F = 14.24, p = 0.00, η²_partial = 0.15] and demonstrated a non-significant small to medium effect on decreased distress levels [F = 3.22, p = 0.08, η²_partial = 0.04]. Contrary to prediction, it was not associated with improvements in self-reported [F = 2.68, p = 0.11, η²_partial = 0.03] or behavioral distress tolerance [F(1) = 0.75, p = 0.39, η²_partial = 0.01], or smoking urges following a stressor [F = 0.22, p = 0.64, η²_partial = 0.00.] These findings suggest that brief mindfulness exercises successfully induce states of mindfulness in non-nicotine-deprived smokers. These exercises might also improve current moment levels of distress, but they do not appear to improve self-report or behavioral indices of distress tolerance.     

In vivo preliminary investigations of the effects of the benzimidazole anthelmintic drug flubendazole on rat embryos and fetuses

Flubendazole, in a new formulation with high systemic bioavailability, has been proposed as a macrofilaricide against filarial diseases.To investigate embryotoxic activity, the new flubendazole formulation was administered orally to Sprague Dawley rats at 2, 3.46, 6.32 mg/kg/day on gestation day (GD) 9.5 and 10.5. Embryos/fetuses were evaluated on GD 11.5, 12.5 or 20.At 6.32 mg/kg/day (C_max = 0.801 μg/mL after single administration), flubendazole initially induced an arrest of embryonic development followed by a generalized cell death that led to 100% embryolethality by GD 12.5.At 3.46 mg/kg/day (C_max = 0.539 μg/mL after single administration), flubendazole markedly reduced embryonic development by GD 12.5 without causing cell death. On GD 20, 80% of fetuses showed malformations.At 2 mg/kg/day (C_max = 0.389 μg/mL after single administration), it did not interfere with rat embryofetal development.     

Extended findings of brain metabolite normalization in MA-dependent subjects across sustained abstinence: A proton MRS study

ObjectiveThe goal of the present study was to extend our previous findings on long-term methamphetamine (MA) use and drug abstinence on brain metabolite levels in an expanded group of MA-dependent individuals.MethodsSeventeen MA abusers with sustained drug abstinence (1–5 years), 30 MA abusers with short-term drug abstinence (1–6 months) and 24 non-substance using controls were studied using MR spectroscopy (MRS). MRS measures of NAA/Cr, Cho/Cr and Cho/NAA were obtained in the anterior cingulate cortex (ACC) and in the primary visual cortex (PVC).ResultsACC-Cho/NAA values were abnormally high in the short-term abstinent group compared to controls [F(1,52) = 18.76, p < 0.0001]. No differences were observed between controls and the long-term abstinent group [F(1,39) = 0.97, p = 0.97]. New evidence of lower ACC-NAA/Cr levels were observed in the short-term abstinent MA abusers compared to controls [F(1,52) = 23.05, p < 0.0001] and long-term abstinent MA abusers [F(1,45) = 7.06, p = 0.01]. No differences were observed between long-term abstinent MA abusers and controls [F(1,39) = 0.48, p = 0.49].ConclusionsThe new findings of relative NAA/Cr normalization across periods of abstinence suggest that adaptive changes following cessation of MA abuse may be broader than initially thought. These changes may contribute to some degree of normalization of neuronal function in the ACC.     

Comparison of average,scaled average,and population bioequivalence methods for assessment of highly variable drugs: An experience with doxifluridine in beagle dogs

Several strategies for overcoming the challenge of establishing bioequivalence (BE) for highly variable drugs (HVDs; drugs having within-subject variability >0.3) have been considered in recent years. Within-subject variability of the area under the curve (AUC_4 h) and peak concentration (C_max) of doxifluridine in the minimal group (n = 24) were 0.444 and 0.491, respectively, meeting the criteria for an HVD. For the large group (n = 60), within-subject variability of the AUC_4 h and C_max were 0.431 and 0.493, respectively. The 90% confidence interval for the AUC_4 h and C_max of the ratio of the test drug to the reference drug exceeded the acceptable BE limits (0.80–1.25) of the ABE (average bioequivalence), in both the minimal and large groups. However, the 90% CI fell within the extended BE limits (0.61–1.64) of the SABE (scaled average bioequivalence), calculated using within-subject variability. The 95% CI of the AUC_4 h and C_max of the ratio of test to reference drug were within the extended BE limit (<1.73) of the PBE (population bioequivalence), calculated using total variance. Our results suggest that the SABE method may be useful for evaluating the BE of HVDs and for meeting the need for international guidelines for BE.     

Pilot toxicokinetic study and absolute oral bioavailability of the Fusarium mycotoxin enniatin B1 in pigs

The aim of present study was to reveal the toxicokinetic properties and absolute oral bioavailability of enniatin B1 in pigs. Five pigs were administered this Fusarium mycotoxin per os and intravenously in a two-way cross-over design. The toxicokinetic profile fitted a two-compartmental model. Enniatin B1 is rapidly absorbed after oral administration (T_1/2a = 0.15 h, T_max = 0.24 h) and rapidly distributed and eliminated as well (T_1/2elα = 0.15 h; T_1/2elβ = 1.57 h). The absolute oral bioavailability is high (90.9%), indicating a clear systemic exposure. After intravenous administration, the mycotoxin is distributed and eliminated rapidly (T_1/2elα = 0.15 h; T_1/2elβ = 1.13 h), in accordance with oral administration.     

Psychographic characteristics,tobacco, and alcohol use in a sample of young adults on the U.S./México border

Few studies using psychographic segmentation have been conducted; even fewer in minority samples. Study aims were to identify psychographic clusters and their relation to tobacco and alcohol use within a predominantly Hispanic (87%) young adult (ages 18–25) sample. Participants (N = 754; 72.5% female; M_age = 20.7 [2.2]) completed the following measures online: sociodemographics, tobacco use history, the Daily Drinking Questionnaire (Collins, Parks, & Marlatt, 1985), a social activities scale, a psychographic survey, a music preference item, the Brief Sensation Seeking Scale (Hoyle, Stephenson, Palmgreen, Lorch, & Donohew, 2002), and the Mini-International Personality Item Pool (Donnellan, Oswald, Baird, & Lucas, 2006). Two step cluster analysis identified two groups. ‘Popular Extroverts’ (49.3% of sample) reported higher: extroversion scores F(1, 652) = 40.03, sensation seeking scores F(1, 652) = 20.38, alcohol use (greater number of drinks per week [F(1, 652) = 9.69]; and past month binge drinking [χ² (1) = 12.80]), and lifetime tobacco use (χ² [1] = 10.61) (all ps ≤ 0.002). ‘Mainstream/Conventionals’ (50.7% of sample) reported greater intentions to smoke in the next month F(1, 284) = 11.81, p = 0.001. ‘Popular Extroverts’ may benefit from prevention/cessation messaging promoting peer support and intensity-oriented activities. For ‘Mainstream/Conventionals,’ messaging communicating negative attitudes toward smoking and the tobacco industry may be effective. Future directions include testing targeted messages which may be incorporated into mass media tobacco and alcohol interventions for young adults on the U.S./México border.     

Improving sublingual delivery of weak base compounds using pHmax concept: Application to propranolol

The purpose of the present work was to provide theoretical and experimental support in generating an optimal pH (pH_max) for a representative weak base compound (propranolol), that can lead to enhanced sublingual absorption. Initially equations for pH-solubility and pH-permeability profiles were derived and compared to the profiles obtained experimentally. Excellent correlation (R² = 0.999) of solubility profiles was obtained using non-linear regression, and the permeability profiles further predicted that at certain pH (pH_max), optimal mucosal permeation could be achieved. Subsequently, in a pharmacokinetics study, a buffered sublingual propranolol tablet, designed to achieve its pH_max (when dissolved in saliva), were compared to that from a marketed product (Inderal^® which could not achieve pH_max) in 8 healthy subjects. Each subject received the products sublingually for 15 min followed by swallowing the remaining drug–saliva. The plasma propranolol concentrations of AUC during first 30 min from the buffered tablet were significantly higher than that from the Inderal^® tablet (p < 0.05), and no significant differences in the remaining AUC were observed. These in vitro and in vivo results on propranolol provided experimental confirmation of the pH_max concept as well as its utility in sublingual drug delivery. Such an approach may be applicable to other similar compounds to improve sublingual drug delivery.     

Pig and guinea pig skin as surrogates for human in vitro penetration studies: A quantitative review

Both human and animal skin in vitro models are used to predict percutaneous penetration in humans. The objective of this review is a quantitative comparison of permeability and lag time measurements between human and animal skin, including an evaluation of the intra and inter species variability. We limit our focus to domestic pig and rodent guinea pig skin as surrogates for human skin, and consider only studies in which both animal and human penetration of a given chemical were measured jointly in the same lab. When the in vitro permeability of pig and human skin were compared, the Pearson product moment correlation coefficient (r) was 0.88 (P < 0.0001), with an intra species average coefficient of variation of skin permeability of 21% for pig and 35% for human, and an inter species average coefficient of variation of 37% for the set of studied compounds (n = 41). The lag times of pig skin and human skin did not correlate (r = 0.35, P = 0.26). When the in vitro permeability of guinea pig and human skin were compared, r = 0.96 (P < 0.0001), with an average intra species coefficient of variation of 19% for guinea pig and 24% for human, and an inter species coefficient of variation of permeability of 41% for the set of studied compounds (n = 15). Lag times of guinea pig and human skin correlated (r = 0.90, P < 0.0001, n = 12). When permeability data was not reported a factor of difference (FOD) of animal to human skin was calculated for pig skin (n = 50) and guinea pig skin (n = 25). For pig skin, 80% of measurements fell within the range 0.3 < FOD < 3. For guinea pig skin, 65% fell within that range. Both pig and guinea pig are good models for human skin permeability and have less variability than the human skin model. The skin model of choice will depend on the final purpose of the study and the compound under investigation.     

Safety and pharmacokinetics of oral delta-9-tetrahydrocannabinol in healthy older subjects: A randomized controlled trial

There is a great concern about the safety of THC-based drugs in older people (≥65 years), as most of THC-trials did not include such group. In this phase 1, randomized, double-blind, double-dummy, placebo-controlled, cross-over trial, we evaluated the safety and pharmacokinetics of three oral doses of Namisol^®, a novel THC in tablet form, in older subjects. Twelve healthy older subjects (6 male; mean age 72±5 years) randomly received a single oral dose of 3 mg, 5 mg, or 6.5 mg of THC or matching placebo, in a crossover manner, on each intervention day. The data for 11 subjects were included in the analysis. The data of 1 subject were excluded due to non-compliance to study medication. THC was safe and well tolerated. The most frequently reported adverse events (AEs) were drowsiness (27%) and dry mouth (11%). Subjects reported more AEs with THC 6.5 mg than with 3 mg (p=0.048), 5 mg (p=0.034) and placebo (p=0.013). There was a wide inter-individual variability in plasma concentrations of THC. Subjects for whom the C_max fell within the sampling period (over 2 h), C_max was 1.42–4.57 ng/mL and T_max was 67–92 min. The AUC_0–2 h (n=11) was 1.67–3.51 ng/mL. Overall, the pharmacodynamic effects of THC were smaller than effects previously reported in young adults. In conclusion, THC appeared to be safe and well tolerated by healthy older individuals. Data on safety and effectiveness of THC in frail older persons are urgently required, as this population could benefit from the therapeutic applications of THC.     

The pharmacokinetics and hypoglycaemic effect of sunitinib in the diabetic rabbits

BackgroundDiabetes is one of the most common metabolic diseases in the world, which may influence changes in the pharmacokinetics and pharmacodynamics of drugs. Sunitinib is a tyrosine kinase inhibitor (TKI) broadly used for treatment of numerous cancers, which exhibits the side hypoglycaemic effect. The aim of the study was a comparison of concentrations and pharmacokinetics of sunitinib after a single administration in rabbits with hyperglycaemia and normoglycaemia (control group). Additionally, the effect of sunitinib on glucose levels was investigated.MethodsThe research was carried out on a control group (n = 6) and a group of rabbits with diabetes (n = 6). The rabbits were treated with sunitinib in the oral dose of 25 mg. Plasma concentrations of sunitinib and its metabolite (SU12662) were measured with validated HPLC method with UV detection.ResultsThe comparison of the sunitinib C_max and AUC_0–∞ in the diabetic group with the control group gave the ratios of 1.63 [90% confidence interval (CI) [1.59; 1.66] and 2.03 [1.97; 2.09], respectively. Statistically significant differences between the analyzed groups were revealed for C_max (p = 0.006), AUC_0–∞ (p = 0.0088), and AUC_kel (p = 0.009). The maximum glycaemia drop of 14.4–69.6% and 15.4–33.5% was observed in the diabetic animals and in the control group, respectively. The glycaemia values returned to the initial values in 24 h after the administration of the drug.ConclusionsThe research proved the significant influence of diabetes on the pharmacokinetics of sunitinib and it confirmed the hypoglycaemic effect of the TKI in diabetic rabbits and in normoglycaemia.     

Evaluation of the in vitro activities of ceftobiprole and comparators in staphylococcal colony or microtitre plate biofilm assays

The aim of this study was to evaluate the in vitro efficacy of ceftobiprole and comparator antibiotics, either alone or in combination, in staphylococcal MBEC™ (minimum biofilm eradication concentration) and colony biofilm assays at dilutions of the maximum free-drug plasma concentration attained during clinical use (fC_max). Staphylococci tested included meticillin-susceptible and meticillin-resistant Staphylococcus aureus (n = 6) and Staphylococcus epidermidis (n = 2). Relative to no-drug controls, after 7 days of exposure ceftobiprole concentrations from 1/4 fC_max to fC_max generally decreased CFUs in MBEC or colony biofilms of S. aureus isolates by ca. 1.5 log₁₀ to ≥2.5 log₁₀. Gentamicin reduced colony biofilm CFUs by ≥1.4 log₁₀ at these concentrations with gentamicin-susceptible isolates. Following 7 days of exposure, vancomycin and rifampicin were ineffective as single agents or in combination in the colony model, but yielded CFU decreases from 0 to 5 log₁₀ in the MBEC model. Treatment of biofilms with rifampicin for 7 days yielded rifampicin-resistant mutants, and the selection of rifampicin resistance was inhibited by co-treatment with ceftobiprole. Thus, ceftobiprole alone or in combination demonstrated promising activity against biofilms of meticillin-susceptible and -resistant staphylococci at clinically relevant concentrations. In contrast, vancomycin and rifampicin, two agents used clinically for the treatment of biofilm infections, tested separately or together gave inconsistent results and generally had little impact on cell viability.     

Alteration of pharmacokinetics of proguanil in healthy volunteers following concurrent administration of efavirenz

Efavirenz and proguanil are likely to be administered concurrently for the treatment of patients with HIV and malaria. The metabolism of proguanil is mediated principally by CYP2C19 while efavirenz is known to inhibit this enzyme. This study therefore investigated the effect of efavirenz on proguanil disposition. Fifteen healthy volunteers were each given 300 mg single oral doses of proguanil alone or with the 9th dose of efavirenz (400 mg daily for 11 days) in a crossover fashion. Blood samples were collected at pre-determined time intervals and analyzed for proguanil and its major metabolite, cycloguanil, using a validated HPLC method. Co-administration of proguanil and efavirenz resulted in significant increases (p < 0.05) in C_max, T_max, AUC_T and elimination half-life (T_1/2β) of proguanil compared with values for proguanil alone [C_max: 2.55 ± 0.24 mg/l vs 3.75 ± 0.48 mg/l; T_max: 2.80 ± 0.99 h vs 4.80 ± 0.99 h; AUC_T: 45.58 ± 12.75 mg h/l vs 97.00 ± 23.33 mg h/l; T_1/2β: 16.50 ± 4.55 h vs 23.24 ± 4.08 h]. Also, efavirenz caused a pronounced decrease in the AUC(metabolite)/AUC(unchanged drug) ratio of proguanil along with a significant decrease (p < 0.05) in C_max and AUC of the metabolite.These results indicate that efavirenz significantly alters the pharmacokinetics of proguanil. These suggest that the protection against malaria by proguanil may be decreased when the drug is co-administered with efavirenz and the antimalarial efficacy is dependent on cycloguanil plasma levels.     

Percutaneous absorption of herbicides derived from 2,4-dichlorophenoxyacid: Structure–activity relationship

Ethyl to octyl esters of 2,4-dichlorophenoxy-acetic acids (2,4DAA), 2,4-dichlorophenoxy-propionic acids (2,4DPA) or 2,4-dichlorophenoxy-butyric acids (2,4DBA) are present in the most commonly used herbicides. Their use involves a significant risk of skin exposure, but little is known about the percutaneous flux of these substances. Studies have shown that percutaneous transition of esters may be dependent on their hydrolysis by esterases present in the skin. In this study, we describe ex vivo percutaneous absorption of seven pure esters (methyl to decyl) with a 2,4DA structure for rats (n = 6) and humans (n = 7). Esters were applied at 50 μL cm⁻² to dermatomed skin (approximately 0.5 mm thick) for 24 h. The enzymatic constants for hydrolysis of each ester by skin esterases were determined in vitro using skin homogenates from both species. Structure–activity relationships linking the evolution of the ex vivo percutaneous flux of esters and the 2,4D structure with enzymatic (V_max; K_m) and/or physical parameters (molecular weight, molecular volume, size of the ester, log(k_ow)) were examined to develop a good flux estimation model. Although the percutaneous penetration of all of the esters of the 2,4D family are “esterase-dependent”, the decreasing linear relationship between percutaneous penetration and hyrophobicity defined by the logarithm for the octanol–water partition coefficient (log(k_ow)) is the most pertinent model for estimating the percutaneous absorption of esters for both species. The mean flux of the free acid production by the esterases of the skin is not the limiting factor for percutaneous penetration. The rate of hydrolysis of the esters in the skin decreases linearly with log(k_ow), which would suggest that either the solubility of the esters in the zones of the skin that are rich in esterases or the accessibility to the active sites of the enzyme is the key factor. The structure–activity relationship resulting from this study makes it possible, in humans and in rats, to make a good estimate of the ex vivo percutaneous fluxes for all pure esters of this family of herbicides.     

Endurance training increases exercise-induced prostacyclin release in young,healthy men – relationship with VO2max

In the present study, we evaluated the effect of 5 weeks of moderate-intensity endurance training on the basal and exercise-induced systemic release of prostacyclin (PGI2), as assessed by plasma 6-keto-PGF_1α concentration. Twelve physically active young men with the following characteristics participated in this study (the mean ± SD): age, 22.7 ±2.0 years; body mass, 76.8 ±8.9 kg; BMI, 23.48 ± 2.17 kg x m^-2; and maximal oxygen uptake (VO2_max), 46.1 ± 4.0 ml x kg^-1 x min^-1. Plasma 6-keto-PGF1_a concentrations were measured in venous blood samples taken prior to the exercise and at exhaustion (at VO_2max) before and after completing the training protocol. On average, the training resulted in a significant increase in VO_2max (p = 0.03), power output at VO_2max (p = 0.001) and a significant increase (p = 0.05) in the net-exercise-induced increase in plasma 6-keto-PGF_1α concentration (Δ6-keto-PGF_1α i.e., the difference between the end-exercise and pre-exercise 6-keto-PGF_1α concentrations). No effect of training on the basal PGI₂ concentration was found. Interestingly, within the study sample (n = 12), two subgroups could be defined with a differential pattern of response with respect to Δ6-keto-PGF_1α concentrations. In one subgroup (n = 7), a significant increase in Δ6-keto-PGF_1α concentration after training was found (p < 0.02) (responders). This enhancement in the exercise-induced PGI₂ release was accompanied by a significant (p < 0.05) increase in VO_2max after training. In contrast, in another subgroup (n = 5), there was no observed effect of training on the Δ6-keto-PGF1_a concentration and the VO_2max after training (non-responders). In both of these subgroups, training did not influence the basal PGI₂ concentration.In conclusion, the endurance training resulted in the adaptive augmentation of the systemic release of PGI2 in response to exercise, which plays a role in the training-induced increase in VO2_max in young, healthy men. The impairment of the training-induced augmentation of PGI₂ release in response to exercise demonstrated in the non-responders subgroup may predispose them to increased cardiovascular risk during vigorous exercise.     

A novel mifepristone-loaded implant for long-term treatment of endometriosis: In vitro and in vivo studies

The objective of this study was to prepare a novel mifepristone-loaded PCL/Pluronic F68 implant to achieve long-term treatment of endometriosis. PCL/Pluronic F68 compound (90/10, w/w) with viscosity average molecular weight of 65,000 was successfully synthesized. The end-capped Pluronic F68 was incorporated in PCL matrixes as molecular dispersion without forming a copolymer. The mifepristone-loaded implant made of PCL/Pluronic F68 compound was a cylindrical capsule with an outer diameter of 2.5 mm and an inner diameter of 2.2 mm. The surface of PCL/Pluronic F68 compound appears porous because Pluronic F68 which is water soluble could leach out due to the water phase. Drug loading of 0.75-, 1.5- and 3.0-cm length implants was 3.05 ± 0.18, 6.06 ± 0.41 and 11.87 ± 0.39 mg, respectively. A sustained mifepristone release rate without obvious initial burst and later decline over a period of 180 d was observed. The cumulative drug release showed a linear relationship with time, indicating that mifepristone release from the implants followed zero-order kinetics (R² > 0.99). The data showed that the C_max and AUC_0–inf were proportional to imlant length and dose, and all groups reached plasma C_max at about the same time (approximately 7 d) and had similar T_1/2 (approximately 150 d) and MRT (approximately 220 d). There were obvious inhibitory effects on the growth of endometrial explants in Wister rats in a dose-dependent manner after administration of mifepristone-loaded implants with implant length from 1.5 to 9.0 cm for 1–3 months. However, mifepristone-loaded implants with implant length of 12.0 cm had no better inhibitory effects on the growth of endometrium when compared with the implants with implant length of 9.0 cm (P > 0.05). In conclusion, subcutaneous implantation of mifepristone-loaded PCL/Pluronic F68 capsules was proven an effective means for long-term treatment of chronic endometriosis.     

Exposure of mice to benzo(a)pyrene impairs endometrial receptivity and reduces the number of implantation sites during early pregnancy

Benzo(a)pyrene (BaP) is a ubiquitous environmental pollutant. Studies have demonstrated it to be an endocrine-disrupting chemical that can cause adverse effects on the female reproductive system. However, the effect of BaP on early pregnancy has not been reported. We investigated the effect of BaP on endometrial receptivity and embryo implantation. Pregnant mice were dosed with BaP at 0.2, 2 and 20 mg/kg/day from day 1 (D1) to day 5 (D5) of gestation. Exposure to BaP impaired the morphology of the endometrium and decreased the number of implantation sites (p_0.2 = 0.006, p₂ = 0.167, p₂₀ = 0.003). Levels of estrodiol (p < 0.001, for three treatment group compare with control group) and progesterone-4 in plasma were elevated in BaP-treatment groups (p_0.2 < 0.001, p₂ < 0.001, p₂₀ = 0.032). Expression of estrogen receptor-α was up-regulated (p_0.2 = 0.002, p₂ = 0.131, p₂₀ = 0.024) whereas expression of the progesterone receptor was down-regulated (p_0.2 < 0.001, p₂ = 0.064, p₂₀ = 0.021). Levels of receptivity-related genes HoxA10 (p_0.2 < 0.001, p₂ = 0.135, p₂₀ < 0.001) and E-cadherin (p_0.2 = 0.002, p₂ = 0.624, p₂₀ = 0.137) were changed by BaP. These results revealed that BaP can disrupt the balance of estrogen and progesterone, influence expression of their receptors and downstream related genes, lead to changes in endometrium receptivity, and reduce of the number of implantation sites.     

BL-1020: A novel antipsychotic drug with GABAergic activity and low catalepsy,is efficacious in a rat model of schizophrenia

Reduced brain γ-amino-butyric acid (GABA) participates in the pathogenesis of schizophrenia. GABA scarcely penetrates the brain. We evaluated the pharmacological properties of BL-1020, a novel GABA ester of perphenazine. Oral BL-1020 or perphenazine were assessed in acute and subchronic schizophrenia rat models. Catalepsy, serum prolactin, receptor binding profile and cortical (PFC), hippocampal (Hip) and dopamine (DA) levels were determined. Radioactive [¹⁴C] labeled BL-1020 was used for pharmacokinetics (PK). Acute and subchronic treatment with BL-1020 antagonized amphetamine-induced hyperactivity, with significantly lower catalepsy and sedation compared to equimolar perphenazine. At the same time, BL-1020 increased DA release in the PFC and Hip. BL-1020 and perphenazine stimulated prolactin secretion equally. BL-1020 displayed strong DA and serotonin (5HT) receptor inhibition (D_2L K_iz = 0.066 nM, D_2S K_i = 0.062 nM, 5-HT_2A K_i = 0.21 nM). PK data revealed that BL-1020 penetrated the brain. Conclusions: The advantages of BL-1020 for treatment of schizophrenia stem from its being a DA/5HT antagonist and a GABAergic agsonist that releases cortical DA and antagonizes amphetamine-induced hyperactivity with reduced catalepsy and sedation     

Human urotensin II in internal mammary and radial arteries of patients undergoing coronary surgery

AimsInternal mammary (IMA) and radial artery (RA) have different incidence of vasospasm and long-term patency rates in arterial grafting. We compared the vasoreactivity of human urotensin II (hU-II) and its receptor with mechanism investigations in IMA and RA.MethodsIMA and RA taken from patients undergoing coronary bypass surgery were studied in organ baths. Urotensin receptor expression was determined by RT-PCR.ResultshU-II contracted IMA with pD₂ of 8.57 ± 0.41 and 45.4 ± 9.1% E_max of contraction to 100 mM KCl, whereas caused less contractile responses in RA (pD₂:8.30 ± 0.79, E_max:20.4 ± 4.8%, p < 0.05). Nifedipine inhibited hU-II-contraction in IMA. In U₄₆₆₁₉-precontraction, hU-II elicited comparable relaxation in IMA (pD₂:8.39 ± 0.43, E_max:56.1 ± 4.0%) and RA (pD₂:9.03 ± 0.46, E_max:65.2 ± 7.1%). The relaxation was abolished by endothelium denudation and by indomethacin, oxadiazoloquinoxalinone or N^ω-nitro-l-arginine, oxyhemoglobin, and Ca²⁺-activated K⁺ channel (K_Ca) blockers. Urotensin receptor mRNA was detected in both arteries.ConclusionshU-II is an important spasmogen in arterial grafts with receptors expressed in IMA and RA. hU-II elicits stronger contraction in IMA than in RA and a moderate endothelium-dependent relaxation attributable to nitric oxide, prostacyclin, and endothelium-derived hyperpolarizing factor with involvement of K_Ca activation. The relaxant response of endothelium-intact IMA and RA to hU-II demonstrates the importance of preservation of endothelium in these grafts.