Estudio del uso de omeprazol en una farmacia comunitaria de la costa de Girona / Study of the Use of Omeprazole in a Community Pharmacy on the Coast of Girona

Antecedentes: En España se vendieron, durante el año 2007,50 millones de fármacos del grupo de los inhibidores de la bomba de protones (IBP), un 26% más que en el año 2006 según los datos de la empresa IMS Health España. Los IBP son fármacos de consumo elevado y en crecimiento progresivo en el Sistema Nacional de Salud. La elevada prevalencia de la dispepsia, su cronicidad y la potencia farmacológica del omeprazol justificarían, en principio, tan elevado consumo. Sin embargo, su utilización en la prevención gastrointestinal es muchas veces inadecuada, tanto por exceso cuando no están indicados, como por defecto en pacientes que deberían tomarlos. Método: Estudio observacional, descriptivo y transversal, realizado durante un periodo de 52 días (de mayo a junio de 2008). Se incluyó a los pacientes mayores de 18 años, que acudieron a la oficina de farmacia solicitando omeprazol, con o sin receta, y que aceptaron participar en el estudio. Los datos se procesaron mediante el programa SPSS V.15. Se estableció la significación estadística a partir de un valor de p <0,05, mediante las pruebas de la t de Student y la chi al cuadrado de Pearson. Resultados: Se incluyó un total de 82 pacientes, situándose la media de edad (± desviación estándar) en 60,8 ± 14,1 años (rango: 25-87), con diferencias significativas por sexos (p=0,048; intervalo de confianza [IC] del 95%: -12,24 a -0,04). El nivel cultural fue alto. La patología más prevalerte resultó ser la dispepsia funcional en un 36% de las solicitudes, la hernia de hiato en el 20,7% y la úlcera gastroduodenal en el 4,9% de la muestra. La demanda de omeprazol por tratamiento representó el 8% de las solicitudes, por prevención el 26% y por mantenimiento el 57%. Un 28% de la muestra no cumplía con los criterios de uso del omeprazol y un 8,5% se automedicaba. El 70,7% de los usuarios de omeprazol lo utilizaba de forma continua, y la duración media del tratamiento era de 4,65 ± 4,4 años (rango: 1-15). En el momento de la adquisición, el 86,6% de los pacientes no presentaba ningún síntoma, y el 91,5% de la muestra creía que el medicamento controlaba su problema de salud (AU)

Background: throughout the year 2007 in Spain, 50 million medicines of the group of proton pump inhibitors were sold, which according to data from the IMS1 is 26% more than in the year 2006. The consumption of these proton pump inhibitors (PPIs)in the Spanish National Health System is high, and is growing steadily. In principle, the high prevalence of dyspepsia, its chronic nature and the pharmacological potency of Omeprazole justify the above mentioned high consumption. However, in many cases its use for gastrointestinal prevention is inappropriate, due both toan excess in cases in which they are not recommended, as well as a lack in patients who should be taking them. Method: cross-sectional, descriptive, observational study, conducted over a period of 52 days (May-June 2008). The study included patients over the age of 18 years who went to the community pharmacy and requested Omeprazole with or without a prescription, and who agreed to participate in the study. The data was processed using SPSS V.15, establishing statistical significance at p<0.05, using Student's t and Pearson's chi-squaretests. Results: a total of 82 patients were included, with an average age of 60.8 years (SD: 14-1) (range of 25 to 87 years), with significant differences by gender (p= 0.048; CI: -12.24 to -0.04). The cultural level was high. The most prevalent pathology turned out to be Functional Dyspepsia, accounting for 36% of the requests; hiatal hernias accounted for 20.7% and gastroduodenal ulcers for 4.9% of the sample. The requests for Omeprazole as a treatment accounted for 8% of the requests, as preventionfor 26% and as maintenance for 57%. Of the total sample, 28% did not meet the criteria for use of Omeprazole3 and 8.5% was self-medicating. Of the Omeprazole users, 70.7% used it in a continuous manner, with an average treatment duration of 4.65 years (SD: 4.4) (range of 1 to 15 years). In 86.6% of the cases the patients did not show any symptoms at the time of acquisition, and 91.5% of the sample believed that the drug controlled their health problem (AU)

Optimization of culture medium and conditions for penicillin acylase production by Streptomyces lavendulae ATCC 13664.

The culture medium for Streptomyces lavendulae ATCC 13664 was optimized on a shake-flask scale by using a statistical factorial design for enhanced production of penicillin acylase. This extracellular enzyme recently has been reported to be a penicillin K acylase, presenting also high hydrolytic activity against penicillin V and other natural aliphatic penicillins such as penicillin K, penicillin F, and penicillin dihydroF. The factorial design indicated that the main factors that positively affect penicillin acylase production by S. lavendulae were the concentration of yeast extract and the presence of oligoelements in the fermentation medium, whereas the presence of olive oil in the medium had no effect on enzyme production. An initial concentration of 2.5% (w/v) yeast extract and 3 microg/mL of CuSO4 x 5H2O was found to be best for acylase production. In such optimized culture medium, fermentation of the microorganism yielded 289 IU/L of enzyme in 72 h when employing a volume medium/volume flask ratio of 0.4 and a 300-rpm shaking speed. The presence of copper, alone and in combination with other metals, stimulated biomass as well as penicillin acylase production. The time course of penicillin acylase production was also studied in the optimized medium and conditions. Enzyme production showed catabolite repression by different carbon sources such as glucose, lactose, citrate, glycerol, and glycine.

Cambios cognitivos en la esquizofrenia bajo tratamiento con olanzapina, risperidona o haloperidol / Cognitive changes in schizophrenic patients receiving olanzapine, rispridone or haloperidol

Se estudia el efecto diferencial de tres antipsicóticos (olanzapina, risperidona y haloperidol) sobre la semiología cognitiva de la esquizofrenia, tanto en el episodio agudo de la enfermedad como en los seis meses posteriores de evolución. Se plantea un diseño simple ciego con un número de 34 pacientes distribuidos aleatoriamente en tres grupos paralelos. Se evalúa la respuesta a través del cambio de las puntuaciones de una batería de tests cognitivos compuesta por el subtest clave de números del WAIS-R, el RAVLT, los tests del trazo A y B, el WCST, el TACP y el test del golpeteo rítmico. Estos tests se pasan en la visita basal, al alta del episodio psicótico agudo y a los 6 meses de evolución. El análisis estadístico se realiza mediante la prueba t de Student. Las dosis medias administradas son: olanzapina (14,6ñ9,4), risperidona (6,5ñ2,9) y haloperidol (18,7ñ8,3).De los resultados cabe destacar que en el grupo de pacientes tratados con olanzapina se producen, a los 6 meses, mejorías significativas del rendimiento en casi todos los tests, mientras que para risperidona solo mejora el rendimiento en el test del trazo A y para haloperidol no se producen variaciones significativas en ningún test. En la exploración correspondiente al alta la comparación entre los tres grupos farmacológicos resulta ventajosa para olanzapina, fenómeno que se repite, con mayor intensidad, a los 6 meses de evolución, no habiendo diferencias significativas entre risperidona y haloperidol (AU)

Biotechnological applications of penicillin acylases: state-of-the-art.

This review describes the most recent developments in the biotechnological applications of penicillin acylases. This group of enzymes is involved mainly in the industrial production of 6-aminopenicillanic acid and the synthesis of semisynthetic beta-lactam antibiotics. In addition, penicillin acylases can also be employed in other useful biotransformations, such as peptide synthesis and the resolution of racemic mixtures of chiral compounds. Particular emphasis is placed on advances in detection of new enzyme specificities towards other natural penicillins, enzyme immobilization, and optimization of enzyme-catalyzed hydrolysis and synthesis in the presence of organic solvents.

Optimization of 6-aminopenicillanic acid (6-APA) production by using a new immobilized penicillin acylase.

A new immobilized penicillin acylase (ECPVA) was obtained by covalent binding of penicillin acylase from Streptomyces lavendulae on Eupergit C. Enzymic hydrolysis of penicillin V catalysed by ECPVA was optimized using a 2(3) factorial design of experiments, and the selected parameters for this study were pH, temperature and substrate concentration. The immobilized enzyme showed an optimal pH value of 9.5-10.5, and an optimal temperature of 60 degrees C, whereas its soluble counterpart showed the same optimal pH value and a lower optimal temperature of 50 degrees C.

Activation and stabilization of penicillin V acylase from streptomyces lavendulae in the presence of glycerol and glycols.

Penicillin V acylase (EC 3.5.1.11) from Streptomyces lavendulae showed both enhanced activity and stability in mixed water/glycerol and water/glycols solvents. The catalytic activity was increased up to a critical concentration of these cosolvents, but further addition of the latter led to a gradual protein deactivation. The highest stabilizing effect was achieved in the presence of glycerol. Thermal stability was increased proportionally to the concentration of glycerol and glycols in the reaction mixture only if the amount added is below the threshold concentration. Reaction conditions that allow simultaneously enhanced activity and stability in the hydrolysis of penicillin V catalyzed by penicillin V acylase from S. lavendulae could be established.

Use of protease inhibitors among persons with AIDS in Los Angeles County.

We evaluated the access to, and the factors associated with, protease inhibitor use among persons with AIDS in Los Angeles County. A population-based sample of adult persons with AIDS is routinely interviewed in Los Angeles County and includes a 30% random sample of men who have sex with men and all other persons reported with AIDS. Since May of 1996, all participants were asked if their physician had ever prescribed a protease inhibitor for their use. The possible association between protease inhibitor use and sociodemographic, temporal and health care factors was assessed for the 12-month period May 1996 through April 1997. Logistic regression was employed for multivariate analysis. Over the 12-month study period, 61.7% (209/339) persons interviewed reported that their physician had prescribed a protease inhibitor as part of their therapy. In bivariate analysis, treatment with protease inhibitor use was more common for whites (71.4%) and US-born Latinos (68.2%) than blacks (53.4%) and foreign-born Latinos (56.6%), among person of higher income (71.2%) than lower (< $10,000) income (50.3%), in those who reported having insurance (66.7%) than those uninsured (47%) and among persons receiving care at private clinics (86.4%) than at HMOs (63.4%) or public clinics (55.2%). An increasing trend of protease inhibitor use with higher educational level and declining CD4+ count was observed. A temporal increase was noted and this trend was most pronounced for persons receiving care at public clinics. In multivariate analysis, persons receiving care at private facilities (adjusted OR = 2.9, 95% CI 1.0, 8.2) and those with higher incomes (adjusted OR = 2.5, 95% CI 1.5, 4.3), were more likely to report that their physician had prescribed a protease inhibitor. The effect of facility type was modified by time. During the first six months of the study period (May 1996-October 1996) persons with AIDS receiving care at public facilities and HMO sites were substantially less likely to report having been offered a protease inhibitor (adjusted OR = 0.13, 95% CI 0.03, 0.58 and adjusted OR = 0.23, 95% CI 0.05, 1.2, respectively). However, no significant facility-specific differences were observed over the last six-month period (November 1997-April 1997) evaluated. Our findings suggest that substantial differences exist in the prescribing and use of protease inhibitors among persons with AIDS in Los Angeles County. Several factors, including facility of HIV care, calendar time, income, education level and level of immunosuppression were independently associated with protease inhibitor use and suggest the existence of important barriers to access. Efforts should be made to identify and remove barriers that will ensure the widest possible access to protease inhibitors for patients with a clinical indication for their use.

Enhanced production of penicillin V acylase from Streptomyces lavendulae.

A 28 degrees C, Streptomyces lavendulae produced high levels of penicillin V acylase (178 IU/l of culture) when grown on skim milk as the sole nutrient source for 275 h. The enzyme showed catabolite repression by glucose and was produced in the stationary phase of growth. Penicillin V was a good inducer of penicillin V acylase formation, while phenoxyacetic acid, the side-chain moiety of penicillin V, did not alter enzyme production significantly. The enzyme was stable between pH 6 and 11 and at temperatures from 20 degrees C to 55 degrees C. This extracellular enzyme was able to hydrolyse natural penicillins and unable to hydrolyse penicillin G.

Chemical mechanism of D-amino acid oxidase from Rhodotorula gracilis: pH dependence of kinetic parameters.

The variation of kinetic parameters of d-amino acid oxidase from Rhodotorula gracilis with pH was used to gain information about the chemical mechanism of the oxidation of D-amino acids catalysed by this flavoenzyme. d-Alanine was the substrate used. The pH dependence of Vmax and Vmax/Km for alanine as substrate showed that a group with a pK value of 6.26-7.95 (pK1) must be unprotonated and a group with a pK of 10.8-9.90 (pK2) must be protonated for activity. The lower pK value corresponded to a group on the enzyme involved in catalysis and whose protonation state was not important for binding. The higher pK value was assumed to be the amino group of the substrate. Profiles of pKi for D-aspartate as competitive inhibitor showed that binding is prevented when a group on the enzyme with a pK value of 8.4 becomes unprotonated; this basic group was not detected in Vmax/Km profiles suggesting its involvement in binding of the beta-carboxylic group of the inhibitor.

Chemical modification of histidyl residues in D-amino acid oxidase from Rhodotorula gracilis.

D-Amino acid oxidase was inactivated by DEP at 30 degrees C and pH 7.5. The reaction followed pseudo-first-order kinetics with a second-order rate constant of 0.254 mM-1.min-1. The pH dependence of the inactivation showed the involvement of a group with a pK of 6.6. The presence of substrate or benzoate protected the enzyme against inactivation. Difference spectra at 242 nm and the reversal of the inactivation in the presence of 1 M hydroxylamine or 0.1 M NaOH pointed to the modification of histidine residues. The statistical analysis of the residual fractional activity versus the number of modified histidine residues led to the conclusion that one histidine residue is essential for the enzyme activity.

New insights on the specificity of penicillin acylase.

In contrast with the general thought that penicillin G acylases (PGAs) were only able to hydrolyse amides or esters of higly hydrophobic acids, we have demonstrated that the PGA from Kluyvera citrophila catalysed the hydrolysis of 4-nitrophenyl esters of acetic, propionic, butyric and valeric acids. Values of kcat. and kcat./Km were greatest for the first compound and less than values for benzylpenicillin by factors of 30 and 7, respectively. 4-Nitrophenyl acetate was hydrolysed faster than 2-nitrophenyl acetate but slower than phenyl acetate. The pH dependence of the reaction was similar to that of benzylpenicillin. Several experiments showed that hydrolysis of 4-nitrophenyl acetate was not catalysed by contaminating esterase activity. The implications for the structural basis of substrate binding are discussed. These substrates open, for the first time, a way to investigate the kinetic parameters of PGA at the presteady-state and provides a new perspective about the role of PGA in nature.

Chemical modification of beta-glucosidase from Trichoderma reesei QM 9414.

The inhibition of beta-glucosidase from Trichoderma reesei QM 9414 by several specific reagents was studied. Diethylpyrocarbonate (DEP) nearly abolished the enzyme activity at concentrations above 10 mM. The presence of substrate or analogs protected the enzyme against inactivation. The reaction followed pseudo-first order kinetics with a second-order rate constant of 0.02 mM-1.min-1. The pH-dependence of the inactivation showed the involvement of a group with a pK of 5.2. Difference spectra at 242 nm and the reversal of the inactivation in the presence of 1 M hydroxylamine indicated the modification of histidine residues. Statistical analysis of residual fractional activity versus the number of modified histidine residues indicated that one histidine residue is essential for catalysis. p-Hydroxymercuribenzoate completely inhibited the enzyme at concentrations of the reagent above 2 mM. Substrate or analogs protected the enzyme against inactivation. The reaction followed pseudo-first order kinetics with a second-order rate constant of 0.002 mM-1.min-1. Treatment of the modified enzyme with 5,5'-dithio-bis(2-nitrobenzoic acid) (DTNB) showed that one cysteine residue was essential for activity. At pH 5.0 2-ethoxy-1-ethoxy-carbonyl-1,2-dihydroquinoline (EEDQ) inactivated the enzyme according to pseudo-first order kinetics with a second-order rate constant of 0.12 min-1. The pH-dependence of the inactivation showed the involvement of a group with a pK of 5.64, indicating the modification of a carboxyl group essential for activity.

Mode of action of endoglucanase III from Trichoderma reesei.

Endoglucanase III (EG III) was purified to homogeneity from the culture medium of Trichoderma reesei QM 9414. It has a molecular mass of 48 kDa, and an isoelectric point of 5.1. Maximal activity was observed between pH4 and 5. Celloligosaccharides and their chromophoric derivatives were used as substrates, and the reaction products were analysed by quantitative h.p.l.c. Nucleophilic competition experiments (between methanol and water) allowed unequivocal assessment of cleavage sites. EG III preferentially released cellobiose (or the corresponding glycoside) from the reducing end of the higher cellodextrins. A putative binding model containing five subsites is proposed. The pH-dependence of 4'-methylumbelliferyl beta-cellotrioside hydrolysis indicates the presence of a protonated group with a pK 5.5 in the reaction mechanism, and the possible involvement of a carboxy group is corroborated by a temperature study (delta Hion = -15.9 J/mol). This, together with independent evidence from affinity-labelling experiments [Tomme, Macarrón and Claeyssens (1991) Cellulose '91, New Orleans, Abstr. 32] and n.m.r. studies [Gebbler, Gilkes, Claeyssens, Wilson, Béguin, Wakarchuk, Kilburn, Miller, Warren and Withers (1992) J. Biol. Chem. 267, 12559-12561], favours the assumption of a lysozyme-type (retention of configuration, two essential carboxy groups) mechanism for this family A cellulase.

Mechanisms of thermoinactivation of endoglucanase I from Trichoderma reesei QM 9414.

The mechanism of irreversible thermoinactivation of endoglucanase I from Trichoderma reesei has been determined at 70 degrees C at the pH of maximum enzyme activity. The time-course of thermoinactivation did not follow first-order kinetics and kinetic constants of the process were dependent on enzyme concentration, suggesting that aggregation was the main process leading to irreversible inactivation. The enzyme was extremely resistant to urea, which in fact seemed to stabilize it against temperature. Disulphide exchange, deamidation and hydrolysis of peptide bonds were also responsible for the loss of enzyme activity at 70 degrees C.

Chemical mechanism of beta-glucosidase from Trichoderma reesei QM 9414. pH-dependence of kinetic parameters.

The variation of kinetic parameters of beta-glucosidase from Trichoderma reesei QM 9414 with pH was used to gain information about the chemical mechanism of the reaction catalysed by this enzyme. The pH-dependence of Vmax. and Vmax./Km for p-nitrophenyl beta-D-glucopyranoside showed that a group with a pK value of 4.3 must be unprotonated and a group with a pK value of 5.9 must be protonated for activity. Temperature and solvent-perturbation studies indicated that these groups are a histidine residue and a carboxy group respectively. Profiles of pKi for maltose as competitive inhibitor showed that binding is prevented when a group on the enzyme with a pK value of 4.5 becomes protonated.

Kinetic mechanism of beta-glucosidase from Trichoderma reesei QM 9414.

beta-Glucosidase is a key enzyme in the hydrolysis of cellulose to D-glucose. beta-Glucosidase was purified from cultures of Trichoderma reesei QM 9414 grown on wheat straw as carbon source. The enzyme hydrolyzed cellobiose and aryl beta-glucosides. The double-reciprocal plots of initial velocity vs. substrate concentration showed substrate inhibition with cellobiose and salicin. However, when p-nitrophenyl beta-D-glucopyranoside was the substrate no inhibition was observed. The corresponding kinetic parameters were: K = 1.09 +/- 0.2 mM and V = 2.09 +/- 0.52 mumol.min-1.mg-1 for salicin; K = 1.22 +/- 0.3 mM and V = 1.14 +/- 0.21 mumol.min-1.mg-1 for cellobiose; K = 0.19 +/- 0.02 mM and V = 29.67 +/- 3.25 mumol.min-1.mg-1 for p-nitrophenyl beta-D-glucopyranoside. Studies of inhibition by products and by alternative product supported an Ordered Uni Bi mechanism for the reaction catalyzed by beta-glucosidase on p-nitrophenyl beta-D-glucopyranoside as substrate. Alternative substrates as salicin and cellobiose, a substrate analog such as maltose and a product analog such as fructose were competitive inhibitors in the p-nitrophenyl beta-D-glucopyranoside hydrolysis.