The low mutational flexibility of the EPSP synthase in Bacillus subtilis is due to a higher demand for shikimate pathway intermediates.

Glyphosate (GS) inhibits the 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase that is required for aromatic amino acid, folate and quinone biosynthesis in Bacillus subtilis and Escherichia coli. The inhibition of the EPSP synthase by GS depletes the cell of these metabolites, resulting in cell death. Here, we show that like the laboratory B.

Ether Oxidation by an Evolved Fungal Heme-Peroxygenase: Insights into Substrate Recognition and Reactivity.

Ethers can be found in the environment as structural, active or even pollutant molecules, although their degradation is not efficient under environmental conditions. Fungal unspecific heme-peroxygenases (UPO were reported to degrade low-molecular-weight ethers through an HO-dependent oxidative cleavage mechanism. Here, we report the oxidation of a series of structurally related aromatic ethers, catalyzed by a laboratory-evolved UPO (PaDa-I) aimed at elucidating the factors influencing this unusual biochemical reaction.

A Novel Way to Secure the Laryngeal Mask Airway During Oral Surgery Procedures.

The laryngeal mask airway (LMA) has been used successfully for an ever-increasing number of applications. Utilization in oral maxillofacial surgery has been hampered by surgical difficulties working around the device. In this case series, a novel device, the LMA-PROP, was used to determine whether it was possible to alleviate device-positioning concerns with third molar extraction cases.

Taking stock of medication wastage: Unused medications in US households.

Background: Despite the potential deleterious impact on patient safety, environmental safety and health care expenditures, the extent of unused prescription medications in US households and reasons for nonuse remain unknown.

Objective: To estimate the extent, type and cost of unused medications and the reasons for their nonuse among US households.

Methods: A cross-sectional, observational two-phased study was conducted using a convenience sample in Southern California.

Inhibition of hepatobiliary transporters by a novel kinase inhibitor contributes to hepatotoxicity in beagle dogs.

PF-022 (1) is a novel polycyclic benzothiophene kinase inhibitor selective for mitogen-activated protein kinase-activated protein kinase 2 (MK2). Compound 1 emerged as an inhibitor bearing submicromolar potency against MK2 (IC50 5 nM) and demonstrated projected human pharmacokinetics sufficient for oral dosing. However, following a single, oral administration of 1 to beagle dogs, animals experienced an acute liver injury characterized by increases in biomarkers associated with hepatotoxicity; particularly noteworthy was the reversible elevation in bile salts and total bilirubin.

N-(3,4-dimethoxyphenethyl)-4-(6,7-dimethoxy-3,4-dihydroisoquinolin-2[1H]-yl)-6,7-dimethoxyquinazolin-2-amine (CP-100,356) as a "chemical knock-out equivalent" to assess the impact of efflux transporters on oral drug absorption in the rat.

The utility of the diaminoquinazoline derivative CP-100,356 as an in vivo probe to selectively assess MDR1/BCRP-mediated drug efflux was examined in the rat. CP-100,356 was devoid of inhibition (IC(50) >50 microM) against major human P450 enzymes including P4503A4. In human MDR1-transfected MDCKII cells, CP-100,356 inhibited acetoxymethyl calcein (calcein-AM) uptake (IC(50) approximately 0.

Role of hepatic transporters in the disposition and hepatotoxicity of a HER2 tyrosine kinase inhibitor CP-724,714.

CP-724,714, a potent and selective orally active HER2 tyrosine kinase inhibitor, was discontinued from clinical development due to unexpected hepatotoxicity in cancer patients. Based on the clinical manifestation of the toxicity, CP-724,714 likely exerted its hepatotoxicity via both hepatocellular injury and hepatobiliary cholestatic mechanisms. The direct cytotoxic effect, hepatobiliary disposition of CP-724,714, and its inhibition of active canalicular transport of bile constituents were evaluated in established human hepatocyte models and in vitro transporter systems.

In vitro P-glycoprotein assays to predict the in vivo interactions of P-glycoprotein with drugs in the central nervous system.

Thirty-one structurally diverse marketed central nervous system (CNS)-active drugs, one active metabolite, and seven non-CNS-active compounds were tested in three P-glycoprotein (P-gp) in vitro assays: transwell assays using MDCK, human MDR1-MDCK, and mouse Mdr1a-MDCK cells, ATPase, and calcein AM inhibition. Additionally, the permeability for these compounds was measured in two in vitro models: parallel artificial membrane permeation assay and apical-to-basolateral apparent permeability in MDCK. The exposure of the same set of compounds in brain and plasma was measured in P-gp knockout (KO) and wild-type (WT) mice after subcutaneous administration.

Role of transporters in the disposition of the selective phosphodiesterase-4 inhibitor (+)-2-[4-({[2-(benzo[1,3]dioxol-5-yloxy)-pyridine-3-carbonyl]-amino}-methyl)-3-fluoro-phenoxy]-propionic acid in rat and human.

The role of transporters in the disposition of (+)-2-[4-({[2-(benzo[1,3]dioxol-5-yloxy)-pyridine-3-carbonyl]-amino}-methyl)-3-fluoro-phenoxy]-propionic acid (CP-671,305), an orally active inhibitor of phosphodiesterase-4, was examined. In bile duct-exteriorized rats, a 7.4-fold decrease in the half-life of CP-671,305 was observed, implicating enterohepatic recirculation.

Inhibition of hepatobiliary transport as a predictive method for clinical hepatotoxicity of nefazodone.

Treatment with the antidepressant nefazodone has been associated with clinical idiosyncratic hepatotoxicty. Using membranes expressing human bile salt export pump (BSEP), human sandwich hepatocytes, and intact rats, we compared nefazodone and its marketed analogs, buspirone and trazodone. We found that nefazodone caused a strong inhibition of BSEP (IC(50) = 9 microM), inhibition of taurocholate efflux in human hepatocytes (IC(50) = 14 microM), and a transient increase in rat serum bile acids 1 h after oral drug administration.

Metabolism and transporter-mediated drug-drug interactions of the endothelin-A receptor antagonist CI-1034.

CI-1034, an endothelin-A receptor antagonist was being developed for pulmonary hypertension. Drug-drug interaction studies using human hepatic microsomes were conducted to assess CYP1A2, CYP2C9, CYP2C19, CYP3A4 and CYP2D6 inhibition potential; CYP3A4 induction potential was evaluated using primary human hepatocytes. CI-1034 moderately inhibited CYP2C9 (IC(50) 39.

Differential interaction of 3-hydroxy-3-methylglutaryl-coa reductase inhibitors with ABCB1, ABCC2, and OATP1B1.

The present study examined the interaction of four 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (atorvastatin, lovastatin, and simvastatin in acid and lactone forms, and pravastatin in acid form only) with multidrug resistance gene 1 (MDR1, ABCB1) P-glycoprotein, multidrug resistance-associated protein 2 (MRP2, ABCC2), and organic anion-transporting polypeptide 1B1 (OATP1B1, SLCO21A6). P-glycoprotein substrate assays were performed using Madin-Darby canine kidney (MDCK) cells expressing MDR1, and the efflux ratios [the ratio of the ratio of basolateral-to-apical apparent permeability and apical-to-basolateral permeability between MDR1 and MDCK] were 1.87, 2.

Changes in brain pH, PO2, PCO2, cerebral blood flow, and blood gases induced by a hyperosmolar oxyreplete hemosubstitute during cardiopulmonary bypass.

Eleven goats (mean weight, 69 +/- 16 kg) underwent 5 hrs of normothermic nonpulsatile cardiopulmonary bypass (CPB) using as priming fluid either a Ringer's based crystalloid priming solution (CP, n = 5) of a hyperosmolar oxyreplete hemosubstitute (HS, n = 6). The HS contained 20% w/v perfluorocarbon (perfluorodecalin), its osmolarity was 800-900 mOsm/1, and the administered dose of perfluorocarbon was 30-50 ml/kg. Otherwise, the experimental procedure was identical for both groups.

Design of a physiologic pulsatile flow cardiopulmonary bypass system for neonates and infants.

Cardiopulmonary bypass surgical techniques that allow a surgeon to operate on the infant's heart use an extracorporeal circuit consisting of a pump, oxygenator, arterial and venous reservoirs, cannulae, an arterial filter, and tubing. The extracorporeal technique currently used in infants and neonates is sometimes associated with neurologic damage. We are developing a modified cardiopulmonary bypass system for neonates that has been tested in vitro and in one animal in vivo.

Value of intraoperative EEG changes during corpus callosotomy in predicting surgical results.

The intraoperative transformation of generalized epileptiform discharges (GED) to lateralized epileptiform activity during the course of corpus callosum sectioning for intractable epilepsy in 37 patients was correlated with percentage of decrease in atonic-tonic seizures with "drops" at mean follow-up of 26 months (range 12-86 months). Twenty-seven (73%) patients had intraoperative interictal discharges, and 21 (78%) showed varying degrees of lateralization of GED during corpus callosum sectioning (two thirds to total). All patients experienced > 80% reduction in atonic-tonic seizures with drops.

Ictus emeticus and the insular cortex.

A 30-year-old man had a long history of seizures that began with feelings of tightness in his throat and fear, followed by projectile vomiting and head and eye deviation to the left. These episodes were not completely controlled by antiepileptic medications. Video EEG monitoring confirmed his clinical description.

Valproic acid loading during intensive monitoring.

Of 35 patients who had generalized tonic-clonic seizures during antiepileptic drug therapy withdrawal, "loading" with valproic acid was effective in limiting these seizures in 32 patients. A loading dose of approximately 12.5 mg/kg was used.

Magnetic resonance imaging, electroencephalogram, and selected neuropsychological testing in staged corpus callosotomy.

A 21-year-old man with medically intractable secondarily generalized atonic seizures underwent a corpus callosotomy on Nov 5, 1981. Though improved, the falling seizures persisted. In January 1984, magnetic resonance imaging (MRI) documented that the anterior quarter of the corpus callosum remained intact.

Valproate and clonazepam comedication in patients with intractable epilepsy.

The efficacy and the potential risk of inducing convulsive or nonconvulsive status epilepticus with the combination of valproate (VPA) and clonazepam (CZP), with or without other anticonvulsant drugs, in 55 patients with intractable epilepsy was evaluated. The patients were treated with VPA and CZP concomitantly for from 3 to 72 months (mean 21.7 months).