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1.
Arch. Soc. Esp. Oftalmol ; 98(3): 155-162, mar. 2023. tab, graf
Artigo em Espanhol | IBECS | ID: ibc-216823

RESUMO

Introducción Brolucizumab es un nuevo fármaco antifactor de crecimiento endotelial vascular (anti-VEGF) administrado con una pauta fija de ocho o 12 semanas que en los estudios HAWK y HARRIER demostró ser no inferior a aflibercept con respecto a la mejor agudeza visual corregida, bajo una menor carga de administración. El objetivo del análisis fue comparar los costes directos sanitarios de ambos anti-VEGF como tratamiento en pacientes con degeneración macular asociada a la edad neovascular. Material y métodos Se realizó un análisis de minimización de costes bajo un horizonte temporal de 25 años y considerando el coste farmacológico, de administración, de pruebas de seguimiento y del manejo de eventos adversos. El uso de recursos fue obtenido de literatura relacionada y validada por expertos clínicos. Se llevaron a cabo diversos análisis de escenarios para comprobar la robustez de los resultados. Resultados Brolucizumab resultó con un menor coste por paciente en comparación con aflibercept, considerando el número de inyecciones derivadas de los estudios HAWK y HARRIER. Este resultado se mantuvo en los diferentes escenarios analizados, excepto frente al número de inyecciones de la pauta flexible de aflibercept del estudio ARIES, ya que la menor discontinuación de tratamiento con brolucizumab conlleva mantener el tratamiento de más pacientes. Al considerar la misma discontinuación, brolucizumab mantuvo los resultados observados en el caso base del análisis. Conclusiones El presente estudio muestra como la pauta de administración fija de brolucizumab puede ayudar a disminuir la carga asistencial para los centros sanitarios y los pacientes (AU)


Introduction Brolucizumab is a novel anti-vascular endothelial growth factor (anti-VEGF) drug administered in a fixed regimen of 8 or 12 weeks which, in the HAWK and HARRIER studies, was shown not to be inferior to aflibercept with respect to the best corrected visual acuity, with a less burdensome treatment regimen. The aim of the analysis was to compare the direct healthcare costs of both anti-VEGF as a treatment in patients with neovascular age-related macular degeneration.Material and methods A cost minimization analysis was performed under a 25-year time horizon and considering the drug costs, administration, follow-up tests, and management of adverse events. Resource use was obtained from the related literature and validated by clinical experts. Various scenario analysis were carried out to check the robustness of the results. Results Brolucizumab resulted in a lower cost per patient compared with aflibercept, considering the number of injections derived from the HAWK and HARRIER studies. This result was maintained in the different scenarios analysed, except for the number of injections of the flexible aflibercept regimen of the ARIES study, since the lower discontinuation of treatment with brolucizumab implies maintaining the treatment of more patients. Considering the same discontinuation, brolucizumab maintained the results observed in the base case of the analysis. Conclusions This study shows how the fixed administration regimen of brolucizumab can help reduce both healthcare and patients’ burden (AU)


Assuntos
Custos e Análise de Custo , Inibidores da Angiogênese/economia , Custos de Medicamentos , Injeções Intravítreas
2.
Arch Soc Esp Oftalmol (Engl Ed) ; 98(3): 155-162, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36371053

RESUMO

INTRODUCTION: Brolucizumab is a novel anti-vascular endothelial growth factor (anti-VEGF) drug administered in a fixed regimen of 8 or 12 weeks which, in the HAWK and HARRIER studies, was shown not to be inferior to aflibercept with respect to the best corrected visual acuity, with a less burdensome treatment regimen. The aim of the analysis was to compare the direct healthcare costs of both anti-VEGF as a treatment in patients with neovascular age-related macular degeneration. MATERIAL AND METHODS: A cost minimization analysis was performed under a 25-year time horizon and considering the drug costs, administration, follow-up tests, and management of adverse events. Resource use was obtained from the related literature and validated by clinical experts. Various scenario analysis were carried out to check the robustness of the results. RESULTS: Brolucizumab resulted in a lower cost per patient compared with aflibercept, considering the number of injections derived from the HAWK and HARRIER studies. This result was maintained in the different scenarios analysed, except for the number of injections of the flexible aflibercept regimen of the ARIES study, since the lower discontinuation of treatment with brolucizumab implies maintaining the treatment of more patients. Considering the same discontinuation, brolucizumab maintained the results observed in the base case of the analysis. CONCLUSIONS: This study shows how the fixed administration regimen of brolucizumab can help reduce both healthcare and patients' burden.


Assuntos
Inibidores da Angiogênese , Degeneração Macular , Humanos , Inibidores da Angiogênese/uso terapêutico , Injeções Intravítreas , Custos e Análise de Custo , Degeneração Macular/tratamento farmacológico
3.
Int J Clin Pract ; 68(10): 1181-9, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25269948

RESUMO

The aim of this study was to develop a user-friendly checklist for critical appraisal of indirect comparisons of drugs, considering clinical, methodological/statistical and quality aspects, mainly to be applied in drug evaluation in the decision-making context. After conducting a review of the literature, we used group consensus to establish the key points of the checklist, focusing mainly on indirect comparisons, but including topics related to network meta-analysis or multiple treatment comparisons. The coordinating group elaborated the first draft, which was reviewed by external experts, re-evaluated by the coordinating group and finally assessed by 23 drug evaluation experts trained in indirect comparisons, who applied the checklist to one study. The Kappa index of agreement was calculated and the final checklist was developed by group consensus including the external experts. The checklist has two parts. The first consists of three eliminatory key questions while the second includes 17 items: 5 regarding quality, 5 regarding clinical issues and 7 dealing with methodology/statistics. The median kappa values of the 23 evaluations were 0.83 (range 0.67-0.93), 0.61 (0.54-0.91) and 0.36 (0.22-1) with regard to quality, clinical aspects and methodology/statistics, respectively. A structured checklist was developed to facilitate critical appraisal of key issues in indirect comparisons, including comments for assessing the consequences of its application to drug evaluation in the decision-making context. Agreement between reviewers in clinical and quality items was good, but weaker in methodology/statistics ones.


Assuntos
Benchmarking , Lista de Checagem , Técnicas de Apoio para a Decisão , Medicina Baseada em Evidências/métodos , Medicina Baseada em Evidências/normas , Humanos
5.
Todo hosp ; (221): 634-639, nov. 2005.
Artigo em Espanhol | IBECS | ID: ibc-59738

RESUMO

Los Servicios de Farmacia hospitalaria han tenido y tienen un papel clave en la implantación y desarrollo de los procesos de selección de medicamentos, desarrollando sistemas y procedimientos de evaluación y selección. En este artículo se analiza el estado de la cuestión apuntando estrategias para la buena selección y dispensación de medicamentos en el hospital (AU)


The hospital pharmacy services have had and continue to have a key role in the introduction and development of medicine selection processes, developing evaluation and selection system and procedures. This article analyses the state of the question, indicating strategies for the good selection and dispensing of medicines in the hospital (AU)


Assuntos
Humanos , Masculino , Feminino , Serviço de Farmácia Hospitalar/classificação , Serviço de Farmácia Hospitalar/organização & administração , Serviço de Farmácia Hospitalar/provisão & distribuição , Avaliação Pré-Clínica de Medicamentos/métodos , Avaliação Pré-Clínica de Medicamentos/tendências , Preparações Farmacêuticas/classificação , Preparações Farmacêuticas/normas , Diagnóstico Medicamentoso/métodos , Diagnóstico Medicamentoso/tendências , Farmacologia/organização & administração , Farmacologia/tendências
6.
Farm. hosp ; 28(6): 419-425, nov.-dic. 2004. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-93373

RESUMO

Objetivo: Evaluar el impacto de una intervención farmacéutica en la aplicación de la terapia secuencial (TS) con fluoroquinolonas.Métodos: Estudio prospectivo comparativo de intervención farmacéutica en dos fases: fase observacional y fase de intervención para la promoción de la TS.Resultados: Se estudiaron 250 pacientes con terapia intravenosa con fluoroquinolonas (113 levofloxacino y 137 ciprofloxacino),siendo 76 y 70, respectivamente, candidatos a un programa de intervención farmacéutica para la promoción de la TS. La intervención farmacéutica mostró, para ambos medicamentos,una disminución de la duración del tratamiento intravenoso y aumento de la duración del tratamiento vía oral, así como una disminuciónde los costes de la medicación, todo ello de forma estadísticamente significativa.Discusión: La promoción de la TS es una oportunidad para expandir el papel clínico del farmacéutico hospitalario y optimizar el tratamiento con fluoroquinolonas, consiguiendo disminuir la terapia intravenosa y constituyendo una alternativa más coste efectiva.(AU)


Objective: To assess the impact of pharmaceutical intervention on the use of sequential therapy (ST) with fluoroquinolones.Methods: A prospective comparative study of pharmaceutical intervention in two stages: observational stage and interventionstage for ST promotion.Results: In all, 250 patients receiving intravenous therapy with fluoroquinolones (113 with levofloxacin and 137 with ciprofloxacin) were studied, with 76 and 70 patients, respectively,being eligible for a pharmaceutical intervention program to promoteST. Pharmaceutical intervention showed a decreased duration of intravenous therapy and increased duration of oral therapy for both drugs, as well as decreased medication-related costs, all in a statistically significant manner.Discussion: ST promotion provides an opportunity to expand the role of hospital pharmacists and to optimize fluoroquinolone-based therapy, which results in decreased intravenous treatments and provides a more cost-effective option (AU)


Assuntos
Humanos , Fluoroquinolonas/uso terapêutico , Assistência Farmacêutica/estatística & dados numéricos , Estudos Prospectivos , Prescrições de Medicamentos/estatística & dados numéricos , Uso de Medicamentos/estatística & dados numéricos , Ciprofloxacina/uso terapêutico , Ofloxacino/uso terapêutico , Administração Oral
7.
Farm. hosp ; 28(6): 426-432, nov.-dic. 2004. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-93374

RESUMO

Objetivo: Valoración clínica de la efectividad del intercambio terapéutico de glibenclamida a gliclazida en el medio hospitalario.Métodos: Estudio abierto, prospectivo y aleatorizado de dos grupos de pacientes: grupo referencia (pacientes que continúan durante el ingreso con el tratamiento ambulatorio de glibenclamida) y grupo intercambio (pacientes a los que se les sustituye glibenclamida por gliclazida según el protocolo de intercambio aprobado en el hospital).La variable de eficacia utilizada fue la glucemia de los 3 días y de los 6 días post-intervención. Se consideró como paciente clínicamente controlado aquel con niveles de glucemia < 200 mg/dL,y como diferencia clínicamente importante niveles de glucemia menor o mayor a 30 mg/dL.Resultados: Se aleatorizaron 116 pacientes. La glucemia del día previo a la intervención en el grupo referencia fue de 177,9mg/dL ± 63,4 vs 171,3 mg/dL ± 52,1 (p = 0,92) en el grupo intercambio. La media de glucemia de los 3 días siguientes a la intervención fue de 156,1 mg/dL ± 47,5 y 177,7 mg/dL ± 36,0(p = 0,14) en el grupo referencia y en el grupo intercambio; y la media de los 6 días fue 142,1 mg/dL ± 36,0 y 172,8 mg/dL ±28,2 respectivamente (p = 0,01). En el grupo referencia el análisis global de las glucemias muestra un mejor control respecto a los datos basales, lo que no se observa en el grupo intercambio, en el que los valores de glucemia se mantienen estables, siendo similares a los basales. En ningún caso, los valores de glucemia mediade 3 y de 6 días superaron los 200 mg/dL, lo que puede considerarse aceptable en un contexto hospitalario. Conclusiones: El intercambio puede realizarse de forma segura en los pacientes, sin que suponga un deterioro clínico en ningún caso, pero sin observarse el mejor control logrado en el grupo referencia (AU)


Objetivo: To clinically assess effectiveness of therapeutic interchange from glibenclamide to gliclazide in the hospital setting.Methods: An open-label prospective, randomized study with two groups of patients: a reference group (patients stillreceiving their previous outpatient regimen of glibenclamide)and an interchange group (patients with gliclazide substituted for glibenclamide according to a hospital-approved interchange protocol).The efficacy end point used was blood glucose at 3 and 6 dayspost-intervention. A patient with blood glucose < 200 mg/L was considered clinically controlled, and blood glucose changes < or >30 mg/dL were considered significant.Results: One hundred and sixteen patients were randomized.Blood glucose on the day before the intervention was 177.9mg/dL ± 63.4 in the reference group versus 171.3 mg/dL ±52.1 in the interchange group (p = 0.92). Mean blood glucoseduring the first 3 days post-intervention was 156.1 mg/dL ± 47.5and 177.7 mg/dL ± 36.0 (p = 0.14) in the reference and interchange groups, respectively; and mean values for the first 6 dayspost-intervention were 142.1 mg/dL ± 36.0 and 172.8 mg/dL ±28.2, respectively (p = 0.01). The overall analysis of blood glucose levels showed a better control in the reference group versus baseline values, which was not seen in the interchange group,where blood glucose remained stable and similar to baseline. In nocase were 3-day and 6-day blood glucose mean levels above 200mg/dL, which may be considered acceptable within the hospitalsetting. Conclusions: Therapeutic interchange may be safely performed with no clinical impairment, but better controls were achieved in the reference group (AU)


Assuntos
Humanos , Compostos de Sulfonilureia/uso terapêutico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Intercambialidade de Medicamentos , Estudos Prospectivos , Gliclazida/uso terapêutico , Índice Glicêmico
8.
Neurosci Lett ; 304(1-2): 37-40, 2001 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-11335049

RESUMO

Increased amounts of phosphorylated neurofilaments (pNF-H and pNF-M) are found in postmortem brains of opioid addicts. Because of the potential relevance of aberrant pNF in opioid addiction (alterations of neuronal cytoskeleton and associated functions), the effects of opiate drugs on pNF-H were investigated in rat brain. Acute morphine (30 mg/kg, 2 h) induced a marked increase in the immunodensity of pNF-H in the cerebral cortex (93%). Chronic morphine (10-100 mg/kg for 5 days) followed by opiate withdrawal resulted in a time-dependent decline in pNF-H (induction of tolerance). Thus, 2 h after the last dose of morphine, the abundance of pNF-H was still increased (27%), which was followed (6-24 h) by down-regulation of pNF-H (5% increase at 6 h; 5% decrease at 12 h, and 29% decrease at 24 h). The acute (10 mg/kg for 2 h) and chronic (2 x 10 mg/kg for 14 days) treatments with naloxone, an opioid receptor antagonist, did not alter pNF-H in the cerebral cortex, suggesting that the opioid receptors (probably the mu-type) modulating the phosphorylation state of NF-H are not tonically activated by endogenous opioids. The results indicate that morphine addiction is associated with an aberrant hyperphophorylation of NF-H in the rat brain.


Assuntos
Morfina/farmacologia , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Entorpecentes/farmacologia , Proteínas de Neurofilamentos/efeitos dos fármacos , Animais , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Masculino , Proteínas de Neurofilamentos/metabolismo , Fosforilação/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
10.
J Neurochem ; 70(3): 1249-57, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9489748

RESUMO

The effects of opiate drugs (heroin, morphine, and methadone) on the levels of G protein-coupled receptor kinase 2 (GRK2) were studied in rat and human brain frontal cortices. The density of brain GRK2 was measured by immunoblot assays in acute and chronic opiate-treated rats as well as in opiate-dependent rats after spontaneous or naloxone-precipitated withdrawal and in human opiate addicts who had died of an opiate overdose. In postmortem brains from human addicts, total GRK2 immunoreactivity was not changed significantly, but the level of the membrane-associated kinase was modestly but significantly increased (12%) compared with matched controls. In rats treated chronically with morphine or methadone modest increases of the enzyme levels (only significant after methadone) were observed. Acute treatments with morphine and methadone induced dose- and time-dependent increases (8-22%) in total GRK2 concentrations [higher increases were observed for the membrane-associated enzyme (46%)]. Spontaneous and naloxone-precipitated withdrawal after chronic morphine or methadone induced a marked up-regulation in the levels of total GRK2 in the rat frontal cortex (18-25%). These results suggest that GRK2 is involved in the short-term regulation of mu-opioid receptors in vivo and that the activity of this regulatory kinase in brain could have a relevant role in opiate tolerance, dependence, and withdrawal.


Assuntos
Encéfalo/enzimologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Morfina/farmacologia , Entorpecentes/farmacologia , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Adolescente , Adulto , Animais , Encéfalo/efeitos dos fármacos , Feminino , Quinase 2 de Receptor Acoplado a Proteína G , Humanos , Masculino , Metadona/farmacologia , Naloxona/farmacologia , Antagonistas de Entorpecentes/farmacologia , Ratos , Ratos Sprague-Dawley , Síndrome de Abstinência a Substâncias/metabolismo , Fatores de Tempo , Quinases de Receptores Adrenérgicos beta
11.
Neuroreport ; 8(7): 1561-5, 1997 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-9189892

RESUMO

NEUROFILAMENT (NF) proteins, the major components of the neuronal cytoskeleton, have been shown to represent previously unknown targets for the chronic effects of morphine in rats. This study was designed to evaluate the abundance of immunoreactive NF-L (68 kDa) proteins in post-mortem brains of chronic opiate addicts who had died of a heroin or methadone overdose. Levels of NF-L proteins were assessed by immunoblotting techniques. Levels of immunoreactive NF-L proteins were markedly decreased (47%, n = 17) in the frontal cortex. The reduced abundance of brain NF-L proteins was not related to the post-mortem delay or to the plasma concentrations of opiates, suggesting that the observed changes represent a specific long-term effect of opiate drugs. Because of the functions associated with NF proteins (e.g. axonal transport), this finding suggests that opiate drugs may induce neuronal damage after chronic abuse in humans.


Assuntos
Córtex Cerebral/metabolismo , Proteínas de Neurofilamentos/metabolismo , Transtornos Relacionados ao Uso de Opioides/metabolismo , Adulto , Western Blotting , Overdose de Drogas , Feminino , Heroína/intoxicação , Humanos , Masculino , Metadona/intoxicação , Peso Molecular
12.
Naunyn Schmiedebergs Arch Pharmacol ; 355(4): 491-500, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9109366

RESUMO

The abundance of protein kinase C-alpha and beta isoforms (PKC-alphabeta), PKC-alpha messenger (m) RNA and guanine nucleotide-binding G protein subunits (G alpha(i1/2), G alpha(o), and G beta) were quantitated in the rat cerebral cortex after acute and chronic treatments with various opiate drugs. Acute (100 mg/kg for 2 h) and chronic (10 to 100 mg/kg for 5 days) treatment with morphine decreased similarly the immunoreactivity of PKC-alphabeta (28% and 32%, respectively). Acute (2 h) and chronic treatment (5 days) with other mu-agonists heroin (30 mg/kg and 10 to 30 mg/kg) and methadone (30 mg/kg and 5 to 30 mg/kg) also induced similar decreases of PKC-alphabeta (acute: 25% and 23%; chronic: 28% and 18%). After the chronic treatments, spontaneous (48 h) or naloxone (2 mg/kg)-precipitated opiate withdrawal (2 h) resulted in up-regulation of PKC-alphabeta above control levels (30-38%), and in the case of morphine withdrawal in a concomitant marked increase in the expression of PKC-alpha mRNA levels (2.3-fold). Acute (2 h) treatments with pentazocine (80 mg/kg, mixed kappa/delta-agonist and mu-antagonist), spiradoline (30 mg/kg, selective kappa-agonist) and [D-Pen2, D-Pen5] enkephalin (14 nmol i.c.v., selective delta-agonist) induced significant decreases of PKC-alphabeta (19-33%). Chronic (5 days) treatment with pentazocine (10 to 80 mg/kg), but not spiradoline (2 to 30 mg/kg), also induced a similar decrease of PKC-alphabeta (35%). In pentazocine- or spiradoline-dependent rats, naloxone (2 mg/kg) did not induce up-regulation of brain PKC-alphabeta. Acute (10 mg/kg for 2 h) and chronic (2x10 mg/kg for 5 and 14 days) treatment with naloxone did not alter PKC-alphabeta immunoreactivity. Chronic, but not acute, treatment with mu-agonists (morphine, heroin and methadone) increased the immunoreactivities of G alpha(i1/2) (33-37%), G alpha(o), (25-41%) and G beta (10-33%) protein subunits. In heroin- and methadone-dependent rats naloxone (2 mg/kg)-precipitated withdrawal (2 h) did not modify the up-regulation of these G proteins induced by chronic mu-opiate treatment. In marked contrast to mu-agonists, chronic treatment with high doses of pentazocine and spiradoline or acute treatment with [D-Pen2, D-Pen5] enkephalin did not result in up-regulation of these G protein subunits. After chronic treatment with mu-agonists, significant negative correlations were found when the percentage changes in immunoreactivity of PKC-alphabeta were related to the percentage changes in immunoreactivity of G alpha(i1/2), (r = -0.53, n = 29) and G beta (r = -0.41, n = 24) in the same brains. PKC-alphabeta abundance did not correlate significantly with the density of G alpha(o) (r = -0.21, n = 28). Together the results indicate that the brain PKC-alphabeta system may play a major regulatory role in opiate tolerance and dependence. Moreover, the possible in vivo cross-communication between this regulatory enzyme and specific inhibitory G proteins may also be of relevance in the cellular and molecular processes of opiate addiction.


Assuntos
Encéfalo/efeitos dos fármacos , Proteínas de Ligação ao GTP/efeitos dos fármacos , Morfina/farmacologia , Entorpecentes/farmacologia , Proteína Quinase C/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Imuno-Histoquímica , Masculino , Metadona/farmacologia , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
13.
Brain Res Mol Brain Res ; 45(1): 154-8, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9105684

RESUMO

Opiate withdrawal has been associated with up-regulation of alpha 2-adrenoceptors (mainly the alpha 2A-subtype) in brain. The modulation of these inhibitory receptors regulating norepinephrine release appears to be a relevant mechanism by which the opiate abstinence syndrome might be counteracted. The aim of this study was to investigate possible changes in alpha 2a-adrenoceptor gene expression as the molecular mechanism underlying the opiate withdrawal-induced up-regulation of alpha 2A-adrenoceptors. In morphine-dependent rats (10-100 mg/kg for 5 days), naloxone (2 mg/kg)-precipitated withdrawal induced a rapid (2 h) and marked up-regulation (111%, P < 0.001) in the expression of alpha 2a-adrenoceptor mRNA (Northern and dot-blot analyses) in the cerebral cortex. Acute and chronic morphine treatments did not alter significantly the expression of cortical alpha 2a-adrenoceptor mRNA. The results indicate that the opiate abstinence syndrome is associated with a transcriptional activation of the alpha 2a-adrenoceptor mRNA which can explain the up-regulation of brain alpha 2A-adrenoceptors during opiate withdrawal.


Assuntos
Encéfalo/metabolismo , Dependência de Morfina/metabolismo , Morfina/farmacologia , Naloxona/farmacologia , Receptores Adrenérgicos alfa 2/biossíntese , Transcrição Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Animais , Northern Blotting , Encéfalo/efeitos dos fármacos , Cinética , Masculino , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley , Síndrome de Abstinência a Substâncias , Fatores de Tempo
14.
Neurosci Lett ; 226(1): 29-32, 1997 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-9153634

RESUMO

To assess the status of opioid receptors in the human brain during the process of opiate addiction, the abundance of immunoreactive mu-opioid receptors was quantitated in postmortem brains of chronic opiate addicts who had died of a heroin or methadone overdose. The immunoreactive levels of the associated enzyme protein kinase C (PKC-alpha and zeta isoforms) and G proteins (G alpha(i1/2) subunits) were also assessed in the same brains. In the frontal cortex of opiate addicts, the abundance of mu-opioid receptors was not different from that obtained in matched controls. The level of Ca2+-dependent PKC-alpha was decreased (25%), whereas that of the atypical PKC-zeta remained unchanged. The density of G alpha(i1/2) proteins also was found to be increased (40%). The results indicate that opiate addiction in humans does not appear to be associated with a reduced density of brain mu-opioid receptors. The sustained down-regulation of PKC-alpha in the brain of opiate addicts would allow the up-regulation of G alpha(i1/2) proteins aimed at compensating the postulated desensitization of the mu-opioid receptor system.


Assuntos
Lobo Frontal/imunologia , Proteína Quinase C/metabolismo , Receptores Opioides mu/metabolismo , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Adolescente , Adulto , Feminino , Humanos , Imuno-Histoquímica , Masculino
15.
Brain Res ; 710(1-2): 28-34, 1996 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-8963671

RESUMO

In the postmortem human brain (20 specimens of frontal cortex, Brodmann area 9) the abundance of immunoreactive protein kinase C (PKC-alpha beta) and the activity of PKC (calcium, phosphatidylserine, and phorbol ester-dependent enzymes) were determined to study the effect of aging (range 1 month to 89 years) on this regulatory enzyme. Also, the abundance of immunoreactive G protein subunits (G alpha i1/2, G alpha i3, G alpha o, G alpha s and G beta) were assessed in parallel to investigate possible relationships with PKC-alpha beta. The abundance of PKC-alpha beta was positively correlated with aging (r = 0.62, n = 20, P < 0.005). Moreover, PKC activity also showed a significant positive correlation with the age of the subject at death (r = 0.55, n = 14, P < 0.05). Because of the known in vitro modulatory role of PKC-alpha beta on G(i) proteins, the existence of an in vivo effect of brain PKC-alpha beta on various G proteins was assessed through correlation analyses. In the brain of the same subjects, there were significant negative correlations between the immunoreactivity of PKC-alpha beta and the immunoreactivities of G alpha i1/2 (r = -0.78, n = 13, P < 0.005) and G alpha i3 (r = -0.58, n = 15, P < 0.005). In the same brains, similar negative, although non-significant, correlations were found between the levels of PKC-alpha beta and those of G alpha o, G alpha s and G beta. The results demonstrate an up-regulation of brain PKC-alpha beta with aging and suggest the existence of a relevant in vivo modulatory role of this regulatory enzyme on inhibitory Gi proteins in the human brain during the process of aging.


Assuntos
Envelhecimento/metabolismo , Encéfalo/enzimologia , Isoenzimas/metabolismo , Proteína Quinase C/metabolismo , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Proteínas de Ligação ao GTP/metabolismo , Humanos , Immunoblotting , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade
16.
Neuroreport ; 7(2): 509-12, 1996 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-8730817

RESUMO

The aim of this study was to quantitate imidazoline receptors in postmortem brains of heroin addicts who died of an opiate overdose. The density of I2-imidazoline receptors ([3H]idazoxan binding in the presence of adrenaline) and the immunoreactivity of the related 29/30 kDa imidazoline receptor protein were decreased (39% and 28%, respectively) in the frontal cortex. The density of brain I2-imidazoline receptors was also decreased in heroin-dependent rats (27%). This novel finding indicates that opiate addiction induces down-regulation of I2-imidazoline receptors in astrocytes, and presumably down-regulation of the functions associated with these receptors.


Assuntos
Química Encefálica/efeitos dos fármacos , Dependência de Heroína/metabolismo , Receptores de Droga/efeitos dos fármacos , Adolescente , Adulto , Animais , Regulação para Baixo/fisiologia , Feminino , Heroína/intoxicação , Humanos , Idazoxano/metabolismo , Receptores de Imidazolinas , Immunoblotting , Técnicas In Vitro , Cinética , Masculino , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Tubulina (Proteína)/metabolismo
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