Proceedings of the Western Pharmacology Society最新文献

Clopidogrel therapy is the standard for prevention of cardiovascular thrombotic events. Clopidogrel is converted to an active thiol by the cytochrome P450 CYP 3A4 and 2C19 enzymes. Recent studies suggest that statins metabolized by CYP3A4 attenuate the anti-aggregatory effect of clopidogrel. We evaluated the effect of CYP3A4-metabolized statins (atorvastatin, group 1) and partially-CYP3A4-metabolized statins (simvastatin, group 2) on platelet aggregation inhibition (PAI) when given concomitantly with clopidogrel as compared to patients who were statin naive (group 3). PAI was measured by PlateletWorks (Helena Laboratories ICHOR) using the platelet P2Y12 receptor agonist ADP (20 micromol). All patients were on clopidogrel therapy (75 mg/day). Non-responsiveness was defined as a PAI of < 35%. There was no statistical difference in mean PAI among groups; a higher prevalence of clopidogrel non-responders was noted in group 1 compared to group 3 (p=0.002). Multivariate analysis, adjusting for unequal presence of metabolic syndrome and hypertension, we found no statistical difference between groups. Our data suggests that statins, either fully or partially metabolized by CYP3A4, do not influence PAI when clopidogrel is used at 75 mg/day, even after adjusting for risk factors. We concluded that concomitant statins with clopidogrel therapy does not influence the effect of clopidogrel in PAI.

Adenosine is a neuromodulator which inhibits the synaptic release of neurotransmitters. However, only little is known of the effects of inhibitory neurotransmitters and modulators on adenosine release. We studied these effects with hippocampal slices from developing (7-day-old) and young adult (3-month-old) mice under normoxic and ishemic conditions. In normoxia, adenosine release was about 3-fold greater in adults than in developing mice. beta-Alanine and L-serine (both 0.1 mM) significantly reduced the release of [3H]adenosine in normoxia in developing mice. Glycine, beta-Alanine and L-serine (all 0.1 mM) had similar effects in ischemia. Taurine depressed concentration- dependently the release in developing mice but had no effect in adults. The simultaneous release of taurine and adenosine may constitute an important protective mechanism under ischemic conditions.

The aim of this pilot study was to compare the efficacy and tolerability of the non-steroidal anti-inflammatory drug (NSAID), diclofenac (2-(2,6-dichloranilino) phenylacetic acid), for treatment of acute pain originated by lower-limb fracture and surgery, with that of diclofenac plus B vitamins. This clinical trial was single-center, prospective randomized and double-blinded. After giving informed consent, patients with lower-limb closed fractures rated their pain on a 10-cm visual analog scale (VAS). Patients were then randomized to receive 75 mg diclofenac or 75 mg diclofenac plus B vitamins (thiamine, pyridoxine and cyanocobalamin) twice daily (all intramuscularly). Patient evaluations of pain intensity were recorded throughout two periods: twenty-four hours pre-surgically and twenty-four hours postsurgical. Twenty-four hours after the first drug administration, patients underwent elective lower-limb surgery. Standardized general anesthetic techniques were used for all patients. Fourteen patients completed the study. The subjects' assessments of limb pain on the visual analog scale showed a significant reduction from baseline values regardless of the treatment group when surveyed at 12, 24, 36 and 48 hr post operation. All treatments showed a similar profile in pain reduction. There were reports of pain in the administration site, but in general, all the regimens were well tolerated.

Wegener's Granulomatosis (WG) is a rare, Multisystem disease of the medium and small sized arteries and veins. It most commonly involves the upper respiratory tract, lungs, and kidneys and often presents as chronic fatigue, upper respiratory infection, sinusitis, and otitis media. Symptoms can include fever, weight loss and fatigue, though these are not usually the primary presenting complaints. development of the disease is highly skewed across ethnicities, with up to 98% of cases being reported in caucasians. We present the case of a 56-year-old African-American male who presented primarily with complaints of uncontrollable fever of unknown origin (FUO) for past two weeks with accompanying sore throat, nasal congestion, night sweats, malaise, and unexplained weight loss of 10 pounds over the past month. Treatment with antibiotics for one week prior to admission showed no relief of symptoms. Chest x-ray showed focal course markings in the right upper lobe. Urinalysis revealed microscopic hematuria and leukocyturia. Chest and abdominal CT scans revealed a right lower lobe pulmonary nodule and heterogeneous areas of enhancement in the spleen. Head CT revealed right mastoid opification. Labs revealed proteinase-3 antibody titer > 100, which is characteristic of WG. Steroids and cyclophosphamide were started with relief of presenting symptoms. Renal biopsy showed pauci-immune P-ANCA associated crescentic and focally necrotizing glomerulonephritis and vascilitis. This case is unique in that the patient presented with primary complaint of FUO. WG should be considered as a rule-out in cases of uncontrollable FUO, even if none of the classic triad of symptoms is present. Though rare, WG should be considered in cases involving non-Caucasian patients.

The antibacterial activity of the ethyl acetate extracts of seven marine sponges collected from the Tunisian Mediterranean coast (Monastir) were tested against eight human pathogenic bacteria and six human pathogenic fungi using the agar disk diffusion method. The results show that 90% of the sponge extracts present significant activity against at least one bacterial strain. Extracts of the sponges Agelas oroides and Axinella damicornis appeared to be quite promising due to their capacity to inhibit the growth of Pseudomonas aeruginosa and gentamycin resistant strains of Listeria monocytogenese and Enterococcus feacalis as well as broad spectrum activity against all the other bacteria. The antifungal activity of these sponge extracts is not so promising, in fact only three among 9 sponge extracts show moderate capacity of growth inhibition against fungi strains. Agelas oroides which shows interesting antibacterial activity, has moderate activity against fungi strains tested in this study. Our results with antibacterial and antifungal activity in vitro open the way for complementary investigation in order to purify and identify active molecules.

There is evidence that local peripheral administration of codeine and morphine produces antinociception through the activation of the ATP-sensitive K(+)-channel. Therefore we evaluated the participation of this channel in the antinociceptive action produced by nalbuphine in the formalin test. Female Wistar rats (160-200 g) were injected in the dorsal surface of the right hind paw with 50 microl of formalin (5%). Nociception was quantified as the number of flinches of the injected paw during 1 hr, whereas a reduction of the number of flinches was considered antinociception. Rats received a s.c. injection (50 microl) into the dorsal surface of the right hind paw of vehicle or increasing doses of nalbuphine (100-400 microg/paw) 20 min before formalin injection into the ipsilateral paw. To determine whether nalbuphine-induced peripheral antinociception was mediated by K(+)-channels, the effect of pretreatment (10 min before formalin injection) with the appropriate vehicle or the ATP-sensitive K(+)-channel inhibitor glibenclamide (25-100 microg/paw) on the antinociceptive effect induced by local peripheral nalbuphine (400 microg/paw) was assessed. Morphine was used as positive antinociceptive control. Local peripheral injection of nalbuphine produced a dose-dependent antinociception during both phases of the test. Local pretreatment with glibenclamide prevented nalbuphine-induced antinociception in a dose-dependent fashion in both phases of the test. Our data suggest that nalbuphine activates ATP-sensitive K(+)-channels in order to produce its peripheral antinociceptive effect.

Pathological as well as physiological angiogenesis is known to be regulated by such factors as nucleotides and Vascular Endothelial Growth Factor (VEGF). Activated P2Y nucleotide receptors have been observed to associate and transactivate VEGF Receptor 2 (VEGFR2), suggesting a cooperation between nucleotide and VEGF signaling in angiogenesis. P2YR mediated VEGFR2 signaling therefore may be important in describing the angiogenic signaling of nucleotides such as ATP. Here, we provide evidence that supports the notion of P2YR-VEGFR2 signaling. The significant angiogenic effect of P2Y1/2 receptor agonists (100 microM ATP and 10 microM 2MS-ATP) on endothelial cell tubulogenesis was suppressed back to near control levels upon addition of 1 microM SU1498 (specific VEGFR2 tyrosine kinase inhibitor). We believe that this P2YR-VEFGR2 signaling is an important component of pathological, as well as physiological angiogenesis.

The present study was designed to assess the antinociceptive efficacy and gastroprotective activity of the mixture of diclofenac and misoprostol and its comparison with celecoxib in rats. The effect of diclofenac/misoprostol and celecoxib was assessed in the 1% formalin test. Female Wistar rats were fasted 12 hr before experiments and diclofenac (10 and 50 mg/kg), misoprostol (100 microg/kg), celecoxib (30 and 100 mg/kg), saline and the combination of diclofenac (50 mg/kg) plus misoprostol (25, 50 and 100 microg/kg) were administered orally. Nociceptive behavior was assessed during the following hr. Diclofenac and celecoxib dose-dependently reduced formalin-induced nociception reaching similar maximal effects. Moreover, misoprostol did not produce antinociception, but increased diclofenac-induced antinociception. Animals were sacrificed 3 hr following drug administration and stomachs examined to assess gastric damage. Misoprostol did not produce any damage to the stomach. However, diclofenac, but not celecoxib, produced significant gastric damage (number of stomach ulcers) in a dose-dependent fashion. Misoprostol dose-dependently reduced diclofenac-induced ulcers. Data show that diclofenac and celecoxib lead to similar antinociception, with diclofenac being more active to produce gastric damage. However, diclofenac-induced gastric damage can be markedly reduced by misoprostol. In addition to its gastroprotective effect, misoprostol showed a synergic effect on diclofenac-induced anti-nociception. Considering the cardiovascular effects of COX-2 selective inhibitors, the combination of diclofenac and misoprostol could represent a safer and effective alternative for patients with pain.

Parkinson's disease is a progressive neurological disorder associated with selective degeneration of nigrostriatal dopaminergic neurons. It is the most common of the neurodegenerative movement disorders, affecting approximately 1% of the population over age 65. Though the exact cause of the neurodegeneration is unknown, it has been shown that environmental factors can contribute to the onset of Parkinson's disease. Parkinsonian symptoms are seen following exposure to the herbicide paraquat, and the fungicide maneb. Furthermore, evidence clearly shows that neurodegeneration develops in environments where workers are co-exposed to paraquat and maneb. These neurotoxins cause a pesticide-induced loss of dopaminergic neurons, inducing a Parkinsonian phenotype. The specific mechanisms by which these environmental neurotoxins affect the nigral dopaminergic neurons are unknown. This gap in mechanistic understanding raises a need for further examination of their cytotoxic effects. Despite advances in pharmacotherapy that have improved quality of life, the mortality rate among Parkinson's disease sufferers remains largely unchanged. There is need for a proactive treatment strategy that could provide neuroprotection or neurorestoration. Since evidence has shown that environmental neurotoxins play an important role in nigral degeneration, there is obviously a need to take a closer look at such toxins since a greater understanding could aid in development of novel pharmacological agents with anti-parkinson and neuroprotective effects. In this review, we intend to examine the role of environmental toxins, namely paraquat and maneb, in the neurotoxicity that leads to dopamine depletion.

N,N-Diethyl-2-[4-(phenylmethyl)phenoxy]ethanamine (DPPE, tesmilifene), a potent chemopotentiating drug currently in Phase III clinical trials of metastatic breast cancer, increases cytotoxicity of anthracyclines and taxanes in a variety of multi-drug resistance expressing (MDR+) tumor cell lines in vitro; inhibits binding of histamine to CYP3A4, a lipid/prostanoid-regulatory P450; and modulates serum levels of HDL/LDL cholesterol and phospholipids in vivo. Since increased exposure of phosphatidylserine (PS) on the outer cell membrane leaflet is associated with apoptosis, increased clearance of dead cells by phagocytes and inhibition of the P-glycoprotein pump, the effect of DPPE on PS synthesis was assessed in vitro in a human breast cancer cell line. MCF-7 cells were incubated with 5 microM DPPE for 24 hr or 5 days, followed by addition of [1-(14)C]arachidonic acid for 4 hr; or [3H]serine for 8 hr. Compared to untreated cells, a 27-42% (p < 0.05) increase in [1-(14)C]arachidonic acid incorporated into all phospholipids, including a 1.9-fold increase (p < 0.05) in PS was observed in DPPE-treated cells. [3H]Serine incorporation into PS was elevated 37%, while the pool size of PS was elevated 23% (p < 0.05) in DPPE-treated cells, indicating elevated de novo PS biosynthesis. Annexin-5 binding studies indicated an elevation in exposure of PS on the surface of the plasma membrane in DPPE-treated cells. DPPE-treatment also resulted in N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine accumulation indicative of phospholipidosis-inducing potential. Thus, the chemopotentiating effect of DPPE may be due to its phospholipidosis-inducing potential and stimulation of PS synthesis leading to an increased exposure of PS on the cell surface which could potentially enhance cancer cell clearance by phagocytes.