Die mycobakteriellen Adenylatcyclasen Rv1625c und Rv0386: Orthodoxe gegenüber unorthodoxer Katalyse

I report on two class III ACs of Mycobacterium tuberculosis which possess very different structural as well as catalytic characteristics: the mammalian-like membrane-anchored Rv1625c and the transcription-factor-attached Rv0386. As a complementary study to published data (Guo et al., 2001), additional point mutations were made which demonstrated the essential role of the six canonical amino acids for catalysis in Rv1625c. The cytosolic mutants of Rv1625c N372A, N372T and D300S were used to investigate dimerization with mammalian AC catalytic units. Rv1625c engineered to contain forskolin binding amino acids cannot be stimulated by the diterpene. The similarities in conformation and mechanisms of catalysis between ACs and GCs was confirmed through the formation of functional chimeras between Mycobacterium Rv1625c and a guanylyl cyclase of Paramecium. The versatility of the class III cyclase homology domains concerning their modular architectures and mechanisms of catalysis was demonstrated with the biochemical characterization of Rv0386. This enzyme has a substrate-defining mechanism distinctly different of that of mammalian ACs. In addition by using ATP as well as GTP as a substrate it is a unique AC isoform unknown so far. Mutational studies of the Rv0386 AC domain proved the essential role that is played by a glutamine and an asparagine instead of the canonical lysine and aspartate for recognition of ATP and GTP as substrates. Diffraction-quality crystals of this AC domain were obtained as a first step to decipher the molecular and structural particularities of its catalytic function. Sequence comparisons identified an ATPase, a HTH DNA-binding and a transcription factor domain in Rv0386. How these domains affect AC activity in a concerted regulatory mechanism remains a pressing question for future studies.Im Rahmen der vorliegenden Arbeit wurden zwei Klasse III ACn aus Mycobacterium tuberculosis mit unterschiedlicher strukturellen und katalytischen Eigenschaften untersucht: die Mammalia-ähnliche Rv1625c und die an einen Transkriptionsfaktor gebundene Rv0386. Als ergänzende Studien zu bereits publizierten Daten (Guo et al., 2001), wurden zur Überprüfung der wesentlichen Rolle der sechs kanonischen Aminosäuren, die bei Mammalia-ACn in der Katalyse beteiligt sind und die in Rv1625c konserviert und auch katalytisch relevant sind, zusätzliche Punktmutationen durchgeführt und getestet. Die Rv1625c Mutanten N372A, N372T und D300S, die einzeln inaktiv sind, wurden für Rekonstitutionsversuchen benutzt wobei die Bildung katalytisch aktiver Homodimere in Rv1625c nachgewiesen wurde. Punktmutationen in Rv1625c, die Forskolin-bindende Aminosäuren in Säugercyclasen betreffen, erfahren dennoch keine Stimulierbarkeit durch das Diterpen. Die Ähnlichkeiten in Struktur und katalytischem Mechanismus zwischen ACn und GCn wurden hier bestätigt, da Chimären zwischen Mycobacterium Rv1625c und einer Guanylatcyclase aus Paramecium aktive katalytische Zentren gebildet haben. Die Vielseitigkeit der Klasse-III Cyclase Homologie Domänen hinsichtlich ihres modularen Aufbaus und ihres katalytischen Mechanismus wurde hier durch die biochemische Charakterisierung von Rv0386 nachgewiesen. Dieses Enzym zeigte einen Mechanismus zur Erkennung des Substrates, der sich von dem der Mammalia-ACn deutlich unterscheidet. Dieser ermöglicht die Erkennung sowohl von ATP als auch GTP als Substrat und ist eine Eigenschaft, die bis jetzt in keiner anderen AC Isoform beobachtet wurde. Mutationen der AC Domäne beweisen die essentielle Rolle, die Glutamin und Asparagine statt dem kanonischen Lysin und Aspartat bei der Erkennung der Substrate ATP und GTP in Rv0386 spielen. Der Erhalt der ersten diffraktionsfähigen Kristalle der AC Domäne innerhalb dieser Arbeit ist ein erster Schritt zur Erkenntnis der Besonderheiten ihrer katalytischen Funktion. Die Suche nach Sequenz Ähnlichkeiten zeigte, dass Rv0386 zusätzlich zu der AC Domäne aus ATPase-, HTH DNA-bindungs- und Transkriptionsfaktor-Domänen besteht. Noch zu beantworten bleibt die Frage, wie die regulatorische Verbindung zwischen der AC Domäne und dem Transkriptionsregulator AC Aktivität und weitere unbekannte Regulationsmechanismen beeinflusst

Prescription errors in a primary care university unit: urgency of pharmaceutical care in Mexico

O objetivo deste trabalho foi avaliar a racionalidade das prescrições como também os erros mais comuns nas prescrições emitidas pelo Centro de Saúde de uma Universidade no México. Foi realizado um estudo retrospectivo de utilização de medicamentos que requeria prescrição médica. 370 expedientes médicos foram aleatoriamente selecionados e revisados, obtendo uma mostra estatísticamente representativa do total de consultas médicas realizadas no período de um ano. A validade da prescrição médica foi feita utilizando as seguintes variáveis: indicação, doses recomendada, via de administração, contra-indicações, interações, duplicação de medicamentos, medicamentos desnecessários ou faltantes. As prescrições médicas foram classificadas como: apropriada (se não foram encontrados erros nas prescrições) ou inapropriada (se foram encontradas ao menos um erro na prescrição). A razão risco-beneficio foi calculada para cada prescrição médica. O estudo revelou alta incidência de prescrições inapropriadas no Centro de Saúde da Universidade do México (58%), causada pelos erros nas doses recomendadas e na seleção do medicamento relacionado com a necessidade do paciente. Como resultado da análise chi2 , foi encontrado que as variáveis fármaco-terapêuticas escolhidas neste estudo para avaliar a prescrição médica, foram determinantes para classificar as prescrições como apropriadas. Nimesulide, ciprofloxacin, ranitidine, ketorolac e paracetamol representaram o maior número de medicamentos prescritos assim como a maior causa de erros encontradas nas prescrições. É importante que um farmacêutico valide os medicamentos prescritos no Centro de Saúde. Este estudo justifica o papel que os farmacêuticos mexicanos deveriam desempenhar para evitar erros na prescrição, como parte importante da equipe médica, assim como a urgência de implementar os cuidados farmacêuticos em todos os estabelecimentos dos Centros de Saúde no México.The purpose of this study was to assess prescription rationality and most common prescription errors at the primary care clinic of a Mexican university.A retrospective drug utilization review of indication-prescription type was carried out. A random sample of 370 medical records of patients assisted over a year period, were reviewed. Prescription appropriateness was evaluated according to the variables: indication, dosage regimen, administration route, contraindications, interactions, medication duplicity, unnecessary or missing medications. Prescriptions were rated as appropriate (no prescription errors found) or inappropriate (at least one prescription error found). The benefit-risk ratio was calculated for each prescription. This study revealed a 58% of inappropriate prescriptions in the Mexican primary care university clinic, mostly due to errors on dosage regimen and innapropiate drug selection. As a result of chi2 analysis, it was found that the pharmacotherapeutic variables chosen for the prescription assessment in this study, were determinant in prescription appropriateness rating. Nimesulide, ciprofloxacin, ranitidine, ketorolac and paracetamol were the most prescribed drugs as well as the most common cause of errors found. The prescription error rate revealed by this study addresses the need for strategies to improve prescription's quality. Introducing pharmacists as a key part of health care team is a mean proposed to prevent medication errors and to solve the urgency of pharmaceutical care implementation in all primary care facilities in Mexico

Análisis de fármacos en aguas residuales de tres hospitales de la ciudad de Puebla, México.

Artículo en revista indizadaMediante sus efluentes, los hospitales contribuyen a la ocurrencia de microcontaminantes emergentes como los fármacos, en el agua. Este trabajo cuantificó la presencia de nueve fármacos en las aguas residuales de tres hospitales privados de México con 66, 92 y 120 camas, respectivamente. Las muestras se caracterizaron fisicoquímicamente y, empleando cromatografía líquida de alta resolución acoplada a espectrometría de masas (UPLC-MS/MS), se reportaron las siguientes concentraciones máximas promedio: paracetamol (38740.11±33832.15 ng/L), naproxeno (6321.42±11074.86 ng/L), ketorolaco (1429.80±237.94 ng/L), ibuprofeno (249.46±143.68 ng/L), ranitidina (149.60±303.70 ng/L), hidrocortisona (96.72±57.21 ng/L), dexametasona (33.02±41.23 ng/L), esomeprazol (22.85±24.12 ng/L) y omeprazol (22.50±23.97 ng/L). En aguas tratadas se detectó una reducción del 67 al 100% en los niveles de hidrocortisona, naproxeno, paracetamol y ranitidina. Los resultados obtenidos informan la presencia de fármacos que no habían sido reportados previamente en efluentes hospitalarios mexicanos y demuestran el impacto de las plantas de tratamiento, contribuyendo a la evidencia existente para impulsar acciones de regulación, innovación tecnológica y monitoreo.Los autores agradecen al Consejo Nacional de Ciencia y Tecnología (CONACYT) de México por el apoyo para la realización de esta investigación dentro del marco del Proyecto No. PN 2016 - 3620. Esta investigación también fue parcialmente apoyada por la Vicerrectoría Académica de la UDLAP (proyecto de investigación interno 2019)

Prescription errors in a primary care university unit: urgency of pharmaceutical care in Mexico Erros de prescrição no Centro de Saúde de uma Universidade: urgência de implementar Atenção Farmacêutica no México

The purpose of this study was to assess prescription rationality and most common prescription errors at the primary care clinic of a Mexican university.A retrospective drug utilization review of indication-prescription type was carried out. A random sample of 370 medical records of patients assisted over a year period, were reviewed. Prescription appropriateness was evaluated according to the variables: indication, dosage regimen, administration route, contraindications, interactions, medication duplicity, unnecessary or missing medications. Prescriptions were rated as appropriate (no prescription errors found) or inappropriate (at least one prescription error found). The benefit-risk ratio was calculated for each prescription. This study revealed a 58% of inappropriate prescriptions in the Mexican primary care university clinic, mostly due to errors on dosage regimen and innapropiate drug selection. As a result of chi2 analysis, it was found that the pharmacotherapeutic variables chosen for the prescription assessment in this study, were determinant in prescription appropriateness rating. Nimesulide, ciprofloxacin, ranitidine, ketorolac and paracetamol were the most prescribed drugs as well as the most common cause of errors found. The prescription error rate revealed by this study addresses the need for strategies to improve prescription's quality. Introducing pharmacists as a key part of health care team is a mean proposed to prevent medication errors and to solve the urgency of pharmaceutical care implementation in all primary care facilities in Mexico.<br>O objetivo deste trabalho foi avaliar a racionalidade das prescrições como também os erros mais comuns nas prescrições emitidas pelo Centro de Saúde de uma Universidade no México. Foi realizado um estudo retrospectivo de utilização de medicamentos que requeria prescrição médica. 370 expedientes médicos foram aleatoriamente selecionados e revisados, obtendo uma mostra estatísticamente representativa do total de consultas médicas realizadas no período de um ano. A validade da prescrição médica foi feita utilizando as seguintes variáveis: indicação, doses recomendada, via de administração, contra-indicações, interações, duplicação de medicamentos, medicamentos desnecessários ou faltantes. As prescrições médicas foram classificadas como: apropriada (se não foram encontrados erros nas prescrições) ou inapropriada (se foram encontradas ao menos um erro na prescrição). A razão risco-beneficio foi calculada para cada prescrição médica. O estudo revelou alta incidência de prescrições inapropriadas no Centro de Saúde da Universidade do México (58%), causada pelos erros nas doses recomendadas e na seleção do medicamento relacionado com a necessidade do paciente. Como resultado da análise chi2 , foi encontrado que as variáveis fármaco-terapêuticas escolhidas neste estudo para avaliar a prescrição médica, foram determinantes para classificar as prescrições como apropriadas. Nimesulide, ciprofloxacin, ranitidine, ketorolac e paracetamol representaram o maior número de medicamentos prescritos assim como a maior causa de erros encontradas nas prescrições. É importante que um farmacêutico valide os medicamentos prescritos no Centro de Saúde. Este estudo justifica o papel que os farmacêuticos mexicanos deveriam desempenhar para evitar erros na prescrição, como parte importante da equipe médica, assim como a urgência de implementar os cuidados farmacêuticos em todos os estabelecimentos dos Centros de Saúde no México

Analysis of Adverse Drug Reactions in Pediatric Patients with Epilepsy: An Intensive Pharmacovigilance Study

Epilepsy is a chronic neurological disease characterized by the presence of spontaneous seizures, with a higher incidence in the pediatric population. Anti-seizure medication (ASM) may produce adverse drug reactions (ADRs) with an elevated frequency and a high severity. Thus, the objective of the present study was to analyze, through intensive pharmacovigilance over 112 months, the ADRs produced by valproic acid (VPA), oxcarbazepine (OXC), phenytoin (PHT), and levetiracetam (LEV), among others, administered to monotherapy or polytherapy for Mexican hospitalized pediatric epilepsy patients. A total of 1034 patients were interviewed; 315 met the inclusion criteria, 211 patients presented ADRs, and 104 did not. A total of 548 ASM-ADRs were identified, and VPA, LEV, and PHT were the main culprit drugs. The most frequent ADRs were drowsiness, irritability, and thrombocytopenia, and the main systems affected were hematologic, nervous, and dermatologic. LEV and OXC caused more nonsevere ADRs, and PHT caused more severe ADRs. The risk analysis showed an association between belonging to the younger groups and polytherapy with ADR presence and between polytherapy and malnutrition with severe ADRs. In addition, most of the severe ADRs were preventable, and most of the nonsevere ADRs were nonpreventable