Design, synthesis and biological evaluation of novel 31-hexyloxy chlorin e6-based 152- or 131-amino acid derivatives as potent photosensitizers for photodynamic therapy.

This study aimed to improve the biological effectiveness and pharmacokinetic properties of chlorin e6, a second-generation photosensitizer (PS), for tumor photodynamic therapy (PDT). Herein, the novel 31-hexyloxy chlorin e6-based 152- or 131-amino acid derivatives 3a, 3b, 3c and 8 were synthesized and their photophysical properties and in vitro bioactivities such as phototoxicity against A549, HeLa and melanoma B16-F10 cells, reactive oxygen species (ROS) production and subcellular localization were evaluated. In addition, preferred target compounds were also investigated for their in vivo pharmacokinetic in SD rats and in vivo antitumor efficacies in C57BL/6 mice bearing melanoma B16-F10 cells. Apparently, simultaneous introduction of amino acid residue and n-hexyloxy chain in chlorin e6 made a significant improvement in photophysical properties, ROS production, in vitro and in vivo PDT efficacy. Encouragingly, all target compounds showed higher in vitro phototoxicity than Talaporfin, and that 3c (152-Lys) exhibited strongest phototoxicity and highest dark toxicity/phototoxicity ratio, followed by 8 (131-Asp), 3a (152-Asp) and 3b (152-Glu). Moreover, in vivo PDT antitumor efficacy of 3a, 3c and 8 was all better than that of Talaporfin, and that both 3c and 8 had stronger PDT antitumor efficiency than 3a. The overall results suggested that these novel 31-hexyloxy chlorin e6-based 152- or 131-amino acid derivatives, especially 3c and 8, might be potential antitumor candidate drugs for clinical treatment of melanoma by PDT.

Cementless arthroplasty with a distal femoral shortening for the treatment of Crowe type IV developmental hip dysplasia.

BACKGROUND: Severe developmental dysplasia of the hip is a surgical challenge. The purpose of this study is to describe the cementless arthroplasty with a distal femoral shortening osteotomy for Crowe type IV developmental hip dysplasia and to report the results of this technique. MATERIALS AND METHODS: 12 patients (2 male and 10 female) of Crowe type IV developmental hip dysplasia operated between January 2005 and December 2010 were included in the study. All had undergone cementless arthroplasty with a distal femoral shortening osteotomy. Acetabular cup was placed at the level of the anatomical position in all the hips. The clinical outcomes were assessed and radiographs were reviewed to evaluate treatment effects. RESULTS: The mean followup for the 12 hips was 52 months (range 36-82 months). The mean Harris hip score improved from 41 points (range 28-54) preoperatively to 85 points (range 79-92) at the final followup. The mean length of bone removed was 30 mm (range 25-40 mm). All the osteotomies healed in a mean time of 13 weeks (range 10-16 weeks). There were no neurovascular injuries, pulmonary embolism or no infections. CONCLUSION: Our study suggests that cementless arthroplasty with a distal femoral shortening is a safe and effective procedure for severe developmental dysplasia of the hip.

Effects of ifenprodil on morphine-induced conditioned place preference and spatial learning and memory in rats.

Drug addiction, as well as learning and memory, share common mechanisms in terms of neural circuits and intracellular signaling pathways. In the present study, the role of N-methyl-D-aspartate (NMDA) receptors, particularly those containing NR2B subunits, in morphine-induced conditioned place preference (CPP) and Morris water maze (MWM) learning and memory task was investigated. CPP was used as a paradigm for assessing the rewarding effect of morphine, and MWM was used to measure spatial learning and memory in male Sprague-Dawley rats. We found that ifenprodil, an antagonist highly selective for NR2B-containing NMDA receptors, dose-dependently blocked the development, maintenance and reinstatement of morphine-induced CPP, without evident impairment of the acquisition and retrieval of spatial memory in the MWM task. However, the consolidation of spatial memory was disrupted by a high dose (10 mg/kg) of ifenprodil. These results clearly demonstrate that NR2B-containing NMDA receptors are actively involved in addiction memory induced by morphine conditioning, but not in the acquisition and retrieval of spatial learning and memory. In conclusion, NR2B-containing NMDA receptors can be considered potential targets for the treatment of opiate addiction.

Dose- and time-dependent, context-induced elevation of dopamine and its metabolites in the nucleus accumbens of morphine-induced CPP rats.

The dopamine (DA) projections from the ventral tegmental area to the nucleus accumbens (NAc) are the key component of the brain reward circuitry. The encoded information by DA in reward-related memory within this circuit during opiate reinforcement requires further clarification. The present study was designed to explore the correlations between morphine dose, retention of morphine-induced conditioned place preference (CPP), morphine-induced changes in levels of DA and its metabolites in the NAc in expression and retention of CPP in Sprague-Dawley male rats. A dose-effect curve for morphine-induced CPP (0.01-10 mg/kg, i.p.) was obtained using 4-day conditioning sessions followed by a CPP test; the retention of morphine CPP was measured with CPP tests after the development of CPP. We found a dose-dependent effect of morphine (from 0.01 to 10.0 mg/kg, i.p.) on both the magnitude and the retention of CPP. During the retention of morphine-induced CPP, a morphine-dose- and time-dependent elevation of DA and its metabolites was observed in the NAc. These changes were absent if the same dose of morphine was injected outside of the conditioning environment (i.e., in the home cage). These results suggest that that the long-lasting elevation of DA and its metabolites in the NAc is attributable mainly to drug-associated context, rather than the residual effect of morphine.

Electroacupuncture reduces voluntary alcohol intake in alcohol-preferring rats via an opiate-sensitive mechanism.

Electroacupuncture (EA) has been shown to modify the effects of various drugs of abuse, including alcohol. Inbred P rats were trained to drink alcohol voluntarily and then subjected to two periods of alcohol deprivation lasting 3 days. During the second deprivation, the rats received either EA or sham EA. The rats were pretreated with naltrexone (5 mg/kg) or saline 30 min before each of the EA or sham EA sessions. Approximately 6 h after the last naltrexone or saline treatment, the alcohol tubes were returned and alcohol and water intakes were recorded later at 2, 4, 6, and 24 h. Only EA led to a decrease in alcohol intake, which was most prominent at 6 and 24 h, and this inhibitory effect of EA was blocked by naltrexone, suggesting that activation of the endogenous opiate system may be responsible for EA's effects on alcohol intake in the alcohol-dependent iP rats.

NR2B-containing NMDA receptor is required for morphine-but not stress-induced reinstatement.

Glutamate receptors are known to be densely distributed in the forebrain rewarding circuits, and glutamatergic transmission is actively involved in the regulation of rewarding and reinstating effects of drugs of abuse. Here we investigated the possible involvement of the N-methyl-D-aspartate (NMDA) receptors in the reinstatement of extinguished morphine conditioned place preference (CPP) in rats. We found that previously extinguished morphine (3 mg/kg, i.p.) CPP was markedly reinstated by a priming injection of morphine (2 mg/kg, i.p.) or an acute environmental stressor (forced swim for 10 min), but not by the stress induced by a 24-h food deprivation. Parallel with this, protein levels of the NMDA receptor 2B subunit (NR2B) were elevated in the nucleus accumbens (NAc) and the hippocampus, but not the prefrontal cortex, of reinstated rats. Systemic administration of an NR2B selective antagonist ifenprodil (1, 3, 10 mg/kg, i.p.) attenuated the reinstatement induced by a priming morphine injection, although not by the forced swim. Ifenprodil (2.0 microg/rat) directly injected into the NAc shell or the CA1 region of the dorsal hippocampus produced a similar effect. These results indicate that the NR2B-containing NMDA receptors in the NAc and the dorsal hippocampus play a significant role in mediating the reinstatement of rewarding responses to morphine.

The role of NR2B containing NMDA receptor in place preference conditioned with morphine and natural reinforcers in rats.

It has been reported that N-methyl-D-aspartate (NMDA) receptor is implicated in drug addiction and antagonists of the NMDA receptor complex can inhibit the development and expression of conditioned place preference (CPP) induced by several addictive drugs, implying that this class of compounds might be considered as candidate for the treatment of substance abuse. To explore this possibility, it is important to evaluate whether the inhibitory effect of NMDA receptor antagonists would be confined to behaviors produced by drugs of abuse only, but not by natural reinforcers. According to the quantitative changes of NMDA receptor subunits, including NR1, NR2A, and NR2B, induced by diverse types of reinforcers, we chose NR2B subunit as the target of research. Experimental results showed that (1) an augmented expression of NR2B subunit was revealed by Western blotting in the nucleus accumbens (NAc) and the hippocampus in rats with CPP induced by morphine, but not by natural rewards such as food, novel environment and social interaction. (2) Ifenprodil, an antagonist highly selective for NR2B subunit of the NMDA receptor, produced a dose-dependent reduction in CPP induced by morphine and novel environment, but not that by food consumption and social interaction. Taking together, these findings suggested that NR2B containing NMDA receptor may be more involved with morphine reward rather than natural rewards, and that antagonism of NR2B may have a potential for the treatment of morphine abuse.

[Inhibitory effect of doxazosin on the growth of transplanted tumor of prostate cancer cell PC-3 in nude mice].

OBJECTIVE: To investigate the effects of alpha1 adrenoceptor antagonist doxazosin on the growth of androgen-independent prostate cancer cell PC-3 transplanted in nude mice. METHODS: PC-3 cells xenografts were transplanted (s.c.) in nude mice, and thirty xenografts were established successively. They were then randomly divided into 5 groups: A (control group), B (doxazosin 3 mg/kg), C (doxazosin 10 mg/kg), D (doxazosin 30 mg/kg), and E (doxazosin 100 mg/kg). Seven days after implantation, doxazosin was administered in sterile water by oral gavage, and the volumes of the transplanted tumors were measured during the therapy twice a week. All the mice were sacrificed after two weeks of doxazosin administration; the tumors were resected to do the following research. Immunohistochemistry of Ki67 and terminal deoxynucleotidyl transferase-mediated dUTP biotin nick end labeling (TUNEL) was done to study the effects of doxazosin on the proliferation and apoptosis of prostate cancer cells; moreover, we also used Western blotting to study the protein expression of Smad-4 and IkappaB alpha. RESULTS: Nude mouse experiments showed that the in vivo doxazosin administration induced a notable decrease in the volumes of prostate cancer xenografts compared with the control group, and the tumor weights were also decreased. Interestingly enough, administration of doxazosin at higher concentrations (10, 30, 100 mg/kg) did not have further effect on tumor suppression. The percentage of PC-3 TUNEL positive cells was significantly higher than that of the control group; while the doxazosin treated groups and the control group did not have statistical difference on the percentage of Ki67 positive cells. In doxazosin treated groups Smad-4 and IkappaB alpha expressions were higher than that of the control group. CONCLUSION: Doxazosin can inhibit the growth of the prostate xenografts in the nude mice by inducing apoptosis without affecting the cell proliferation. Activation of transforming growth factor beta1 (TGF-beta1) signaling pathway may be the mechanism underlying doxazosin-mediated apoptosis.