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1.
J Clin Med ; 11(11)2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35683376

RESUMO

Primary hepatic angiosarcoma (PHA) is a rare malignant tumor of the liver, and data on patient outcome after surgical treatment are scarce. The aim of this study was to evaluate postoperative morbidity and overall survival (OS) of patients who underwent hepatectomy for PHA. This is a bicentric retrospective analysis of all consecutive patients who underwent liver resection in curative intent for PHA between 2012 and 2019 at the University Hospital of Muenster and the University Hospital of Bern. Nine patients (five female, four male) were included from both centers. Median age was 72 years (44-82). Most lesions (77.8%) were larger than 5 cm, and mean size of the biggest lesion was 9.4 ± 4.5 cm. Major hepatectomy was performed in four (44.4%), and radical resection (R0) was achieved in six (66.7%) patients. Postoperative complication rate was 88.8%, including 44.4% higher than 3a in the Clavien-Dindo classification. OS survival rates at 1, 2, and 3 years were 44.4%, 22.2%, and 12.5%, respectively, and median OS was 5 months. OS was significantly better after radical resection (R0: 15 months vs. R1: 0 months, p = 0.04), whereas presentation with tumor rupture at diagnosis was associated with the worst OS (0 months vs. 15 months, p = 0.005). Disease recurrence occurred in three patients (33.3%) between three and seven months after surgery. Radical resection remains the only potentially curative treatment option for PHA. However, postoperative morbidity is high, and the overall prognosis remains poor. Multimodal therapy options and management strategies are urgently needed and could improve the prognosis of patients suffering from PHA in the future.

2.
J Clin Med ; 11(7)2022 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-35407514

RESUMO

Surgery has become well established for patients with colorectal and neuroendocrine liver metastases. However, the value of this procedure in non-colorectal and non-neuroendocrine metastases (NCRNNELMs) remains unclear. We analyzed the outcomes of patients that underwent liver surgery for NCRNNELMs and for colorectal liver metastases (CRLMs) between 2012 and 2017 at our institution. Prognostic factors of overall and recurrence-free survival were analyzed, and a comparison of survival between two groups was performed. Seventy-three patients (30 NCRNNELM and 43 CRLM) were included in this study. Although the mean age, extrahepatic metastases, and rate of reoperation were significantly different between the groups, recurrence-free survival was comparable. The 5-year overall survival rates were 38% for NCRNNELM and 55% for CRLM. In univariate analysis, a patient age of ≥60 years, endodermal origin of the primary tumor, and major complications were negative prognostic factors. Resection for NCRNNELM showed comparable results to resection for CRLM. Age, the embryological origin of the primary tumor, and the number of metastases might be the criteria for patient selection.

3.
Diabetes Res Clin Pract ; 173: 108691, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33549675

RESUMO

AIMS: Systemic inhibition of dipeptidyl peptidase 4 (DPP4) showed a protective effect in several transplant models. Here we assessed the specific role of extrarenal DPP4 in renal transplant rejection. METHODS: Kidneys from wildtype (wt) F344 rats were either transplanted in wt Dark Agouti or congenic rats not expressing DPP4. The remaining, not transplanted donor kidney served as healthy controls. To investigate early inflammatory events rats were sacrificed 3 days after transplantation and kidneys were evaluated for inflammatory cells, capillary rarefaction, proliferation, apoptosis and myofibroblasts by immunohistochemistry. RESULTS: Capillary ERG-1-positive endothelial cells were significantly more abundant in renal cortex when transplanted into DPP4 deficient compared to wt recipients. In contrast, TGF-ß and myofibroblasts were reduced by more than 25% in kidneys transplanted into DPP4 deficient compared to wt recipients. Numbers of CD161a-positive NK-cells were significantly lower in allografts in DPP4 deficient compared to wt recipients. Numbers of all other investigated immune cells were not affected by the lack of extrarenal DPP4. CONCLUSION: In early transplant rejection extrarenal DPP4 is involved in the recruitment of NK-cells and early fibrosis. Beneficial effects were less pronounced than reported for systemic DPP4 inhibition, indicating that renal DPP4 is an important player in transplantation-mediated injury.


Assuntos
Actinas/metabolismo , Dipeptidil Peptidase 4/metabolismo , Transplante de Rim/métodos , Células Matadoras Naturais/metabolismo , Músculo Liso/metabolismo , Miofibroblastos/metabolismo , Subfamília B de Receptores Semelhantes a Lectina de Células NK/metabolismo , Doença Aguda , Animais , Modelos Animais de Doenças , Masculino , Ratos , Regulação para Cima
4.
Vet Comp Oncol ; 17(3): 211-220, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30719836

RESUMO

Canine oral malignant melanoma (COMM) is a potentially lethal cancer disease. We established primary cell lines from mostly amelanotic primary COMM and metastases and assessed lesions and derived cells for Melan A, PNL2 and CD146 expression. Then, migration and invasion of CD146-enriched vs -depleted COMM cells were analysed. Epithelial-to-mesenchymal transition (EMT) was addressed by Vimentin-staining and MMP2/MMP9 zymography. Phagocytic behaviour was analysed by histopathological examination and phagocytosis assay. While Melan A- and PNL2-staining yielded inconsistent data, 100% of COMM sections and primary cells showed CD146 expression, suggesting that this protein may serve as a prognostic marker. An overall correlation between CD146-expression and migration/invasion was not observed. All primary cell lines consistently expressed Vimentin and secreted biologically active MMP2, indicating that they had undergone EMT. Importantly, COMM sections exhibited cell-in-cell structures, and all primary cell lines exhibited phagocytic activity, supporting the concept that cell cannibalism may have a role in COMM progression.


Assuntos
Doenças do Cão , Melanoma/veterinária , Células-Tronco Mesenquimais/fisiologia , Neoplasias Bucais/veterinária , Fagocitose/fisiologia , Animais , Antígeno CD146/genética , Antígeno CD146/metabolismo , Adesão Celular , Movimento Celular/fisiologia , Células Cultivadas , Cães , Regulação Neoplásica da Expressão Gênica/fisiologia , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Invasividade Neoplásica , Vimentina/genética , Vimentina/metabolismo
5.
Schizophr Bull ; 38(1): 167-77, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20513652

RESUMO

OBJECTIVE: While all second-generation antipsychotics (SGAs) are promoted for having a low risk of extrapyramidal side effects (EPS), clinical observations suggest differences between the various agents. Nevertheless, this question has never been examined in a systematic review and meta-analysis of head-to-head comparisons. METHODS: We searched the register of the Cochrane schizophrenia group (last search May 2007), supplemented by MEDLINE (last search July 2009) for randomized, blinded studies comparing the following SGAs in the treatment of schizophrenia or related disorders: amisulpride, aripiprazole, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone, and zotepine. At least 3 reviewers extracted the data independently. The primary outcome was "use of antiparkinson medication." The results were combined in a meta-analysis. RESULTS: We included 54 studies with 116 arms. Risperidone was associated with more use of antiparkinson medication than clozapine, olanzapine, quetiapine, and ziprasidone. Ziprasidone showed more use of antiparkinson medication than olanzapine and quetiapine and zotepine more than clozapine. There was no significant difference between amisulpride and its comparators (olanzapine, risperidone, or ziprasidone). Quetiapine showed significantly less use of antiparkinson medication than the 3 other SGAs it was compared with (olanzapine, risperidone, and ziprasidone). Scale-derived data (Barnes Akathisia Scale and Simpson Angus Scale) were limited. CONCLUSIONS: Our meta-analysis demonstrates that there are differences between the SGAs in their ability to induce EPS that clinicians consider warrant treatment with antimuscarinic drugs. Even though the differences were relatively small, they might be important for individual patients and should be taken into account in drug choice.


Assuntos
Acatisia Induzida por Medicamentos , Antipsicóticos/efeitos adversos , Antipsicóticos/uso terapêutico , Tratos Extrapiramidais/efeitos dos fármacos , Esquizofrenia/tratamento farmacológico , Determinação de Ponto Final , Humanos
6.
Cochrane Database Syst Rev ; (1): CD006626, 2011 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-21249678

RESUMO

BACKGROUND: In many countries of the industrialised world second-generation ("atypical") antipsychotics (SGAs) have become the first line drug treatment for people with schizophrenia. The question as to whether and if so how much the effects of the various SGAs differ is a matter of debate. In this review we examined how the efficacy and tolerability of risperidone differs from that of other SGAs. OBJECTIVES: To evaluate the effects of risperidone compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychosis. SEARCH STRATEGY: 1. Electronic searching We searched the Cochrane Schizophrenia Group Trials Register (April 2007) which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO.2. Reference searching We inspected the references of all identified studies for more trials.3. Personal contact We contacted the first author of each included study for missing information.4. Drug companies We contacted the manufacturers of all atypical antipsychotics included for additional data. SELECTION CRITERIA: We included all randomised, blinded trials comparing oral risperidone with oral forms of amisulpride, aripiprazole, clozapine, olanzapine, quetiapine, sertindole, ziprasidone or zotepine in people with schizophrenia or schizophrenia-like psychosis. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated risk ratio (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated mean differences (MD), again based on a random-effects model. MAIN RESULTS: The review currently includes 45 blinded RCTs with 7760 participants. The number of RCTs available for each comparison varied: four studies compared risperidone with amisulpride, two with aripiprazole, 11 with clozapine, 23 with olanzapine, eleven with quetiapine, two with sertindole, three with ziprasidone and none with zotepine. Attrition from these studies was high (46.9%), leaving the interpretation of results problematic. Furthermore, 60% were industry sponsored, which can be a source of bias.There were few significant differences in overall acceptability of treatment as measured by leaving the studies early. Risperidone was slightly less acceptable than olanzapine, and slightly more acceptable than ziprasidone in this regard.Risperidone improved the general mental state (PANSS total score) slightly less than olanzapine (15 RCTs, n = 2390, MD 1.94 CI 0.58 to 3.31), but slightly more than quetiapine (9 RCTs, n = 1953, MD -3.09 CI -5.16 to -1.01) and ziprasidone (3 RCTs, n = 1016, MD -3.91 CI -7.55 to -0.27). The comparisons with the other SGA drugs were equivocal. Risperidone was also less efficacious than olanzapine and clozapine in terms of leaving the studies early due to inefficacy, but more efficacious than ziprasidone in the same outcome.Risperidone produced somewhat more extrapyramidal side effects than a number of other SGAs (use of antiparkinson medication versus clozapine 6 RCTs, n = 304, RR 2.57 CI 1.47 to 4.48, NNH 6 CI 33 to 3; versus olanzapine 13 RCTs, n = 2599, RR 1.28 CI 1.06 to 1.55, NNH 17 CI 9 to 100; versus quetiapine 6 RCTs, n = 1715, RR 1.98 CI 1.16 to 3.39, NNH 20 CI 10 to 100; versus ziprasidone 2 RCTs, n = 822, RR 1.42 CI 1.03 to 1.96, NNH not estimable; parkinsonism versus sertindole 1 RCT, n = 321, RR 4.11 CI 1.44 to 11.73, NNH 14 CI 100 to 8). Risperidone also increased prolactin levels clearly more than all comparators, except for amisulpride and sertindole for which no data were available.Other adverse events were less consistently reported, but risperidone may well produce more weight gain and/or associated metabolic problems than amisulpride (weight gain: 3 RCTs, n = 585, MD 0.99 CI 0.37 to 1.61), aripiprazole (cholesterol increase: 1 RCT, n = 83, MD 22.30 CI 4.91 to 39.69) and ziprasidone (cholesterol increase 2 RCTs, n = 767, MD 8.58 CI 1.11 to 16.04) but less than clozapine (weight gain 3 RCTs n = 373, MD -3.30 CI -5.65 to -0.95), olanzapine (weight gain 13 RCTs, n = 2116, MD -2.61 CI -3.74 to -1.48), quetiapine (cholesterol increase: 5 RCTs, n = 1433, MD -8.49 CI -12. 23 to -4.75) and sertindole (weight gain: 2 RCTs, n = 328, MD -0.99 CI -1.86 to -0.12). It may be less sedating than clozapine and quetiapine, lengthen the QTc interval less than sertindole (QTc change: 2 RCTs, n = 495, MD -18.60 CI -22.37 to 14.83), produce fewer seizures than clozapine (2 RCTs, n = 354, RR 0.22 CI 0.07 to 0.70, NNT 14 CI 8 to 33) and less sexual dysfunction in men than sertindole (2 RCTs, n = 437, RR 0.34 CI 0.16 to 0.76, NNT 13 CI 8 to 33). AUTHORS' CONCLUSIONS: Risperidone seems to produce somewhat more extrapyramidal side effects and clearly more prolactin increase than most other SGAs. It may also differ from other compounds in efficacy and in the occurrence of other adverse effects such as weight gain, metabolic problems, cardiac effects, sedation and seizures. Nevertheless, the large proportion of participants leaving studies early and incomplete reporting of outcomes makes it difficult to draw firm conclusions. Further large trials, especially comparing risperidone with those other new drugs for which only a few RCTs are available, are needed.


Assuntos
Antipsicóticos/uso terapêutico , Risperidona/uso terapêutico , Esquizofrenia/tratamento farmacológico , Amissulprida , Antipsicóticos/efeitos adversos , Aripiprazol , Benzodiazepinas/uso terapêutico , Clozapina/uso terapêutico , Dibenzotiazepinas/uso terapêutico , Humanos , Imidazóis/uso terapêutico , Indóis/uso terapêutico , Olanzapina , Piperazinas/uso terapêutico , Fumarato de Quetiapina , Quinolonas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Risperidona/efeitos adversos , Sulpirida/análogos & derivados , Sulpirida/uso terapêutico , Tiazóis/uso terapêutico
7.
Cochrane Database Syst Rev ; (11): CD006633, 2010 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-21069690

RESUMO

BACKGROUND: Clozapine is an atypical antipsychotic demonstrated to be superior in the treatment of refractory schizophrenia which causes fewer movement disorders. Clozapine, however, entails a significant risk of serious blood disorders such as agranulocytosis which could be potentially fatal. Currently there are a number of newer antipsychotics which have been developed with the purpose to find both a better tolerability profile and a superior effectiveness. OBJECTIVES: To compare the clinical effects of clozapine with other atypical antipsychotics (such as amisulpride, aripiprazole, olanzapine, quetiapine, risperidone, sertindole, ziprasidone and zotepine) in the treatment of schizophrenia and schizophrenia-like psychoses. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Groups Register (June 2007) and reference lists of all included randomised controlled trials. We also manually searched appropriate journals and conference proceedings relating to clozapine combination strategies and contacted relevant pharmaceutical companies. SELECTION CRITERIA: All relevant randomised, at least single-blind trials, comparing clozapine with other atypical antipsychotics, any dose and oral formulations, for people with schizophrenia or related disorders. DATA COLLECTION AND ANALYSIS: We selected trials and extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) based on a random-effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated mean differences (MD) again based on a random-effects model. MAIN RESULTS: The review currently includes 27 blinded randomised controlled trials, which involved 3099 participants. Twelve randomised control trials compared clozapine with olanzapine, five with quetiapine, nine with risperidone, one with ziprasidone and two with zotepine. Attrition from these studies was high (overall 30.1%), leaving the interpretation of results problematic. Clozapine had a higher attrition rate due to adverse effects than olanzapine (9 RCTs, n=1674, RR 1.60 CI 1.07 to 2.40, NNT 25 CI 15 to 73) and risperidone (6 RCTs, n=627, RR 1.88 CI 1.11 to 3.21, NNT 16 CI 9 to 59). Fewer participants in the clozapine groups left the trials early due to inefficacy than risperidone (6 RCTs, n=627, RR 0.40 CI 0.23 to 0.70, NNT 11 CI 7 to 21), suggesting a certain higher efficacy of clozapine.Clozapine was more efficacious than zotepine in improving the participants general mental state (BPRS total score: 1 RCT, n=59, MD -6.00 CI -9.83 to -2.17), but not consistently more than olanzapine, quetiapine, risperidone and ziprasidone. There was no significant difference between clozapine and olanzapine or risperidone in terms of positive or negative symptoms of schizophrenia. According to two studies from China quetiapine was more efficacious for negative symptoms than clozapine (2 RCTs, n=142, MD 2.23 CI 0.99 to 3.48).Clozapine produced somewhat fewer extrapyramidal side-effects than risperidone (use of antiparkinson medication: 6 RCTs, n=304, RR 0.39 CI 0.22 to 0.68, NNT 7 CI 5 to 18) and zotepine (n=59, RR 0.05 CI 0.00 to 0.86, NNT 3 CI 2 to 5). More participants in the clozapine group showed decreased white blood cells than those taking olanzapine, more hypersalivation and sedation than those on olanzapine, risperidone and quetiapine and more seizures than people on olanzapine and risperidone. Also clozapine produced an important weight gain not seen with risperidone.Other differences in adverse effects were less documented and should be replicated, for example, clozapine did not alter prolactin levels whereas olanzapine, risperidone and zotepine did; compared with quetiapine, clozapine produced a higher incidence of electrocardiogram (ECG) alterations; and compared with quetiapine and risperidone clozapine produced a higher increase of triglyceride levels. Other findings that should be replicated were: clozapine improved social functioning less than risperidone and fewer participants in the clozapine group had to be hospitalised to avoid suicide attempts compared to olanzapine.Other important outcomes such as service use, cognitive functioning, satisfaction with care or quality of life were rarely reported. AUTHORS' CONCLUSIONS: Clozapine may be a little more efficacious than zotepine and risperidone but further trials are required to confirm this finding. Clozapine differs more clearly in adverse effects from other second generation antipsychotics and the side-effect profile could be key in the selection of treatment depending on the clinical situation and a patient's preferences. Data on other important outcomes such as cognitive functioning, quality of life, death or service use are currently largely missing, making further large and well-designed trials necessary. It is also important to take into account that the large number of people leaving the studies early limits the validity and interpretation of our findings.


Assuntos
Antipsicóticos/uso terapêutico , Clozapina/uso terapêutico , Esquizofrenia/tratamento farmacológico , Benzodiazepinas/uso terapêutico , Dibenzotiazepinas/uso terapêutico , Dibenzotiepinas/uso terapêutico , Humanos , Olanzapina , Piperazinas/uso terapêutico , Fumarato de Quetiapina , Ensaios Clínicos Controlados Aleatórios como Assunto , Risperidona/uso terapêutico , Tiazóis/uso terapêutico
8.
Cochrane Database Syst Rev ; (10): CD006628, 2010 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-20927748

RESUMO

BACKGROUND: In many parts of the world, particularly in industrialised countries, second generation (atypical) antipsychotic drugs have become first line treatment for people suffering from schizophrenia. The question as to whether the effects of various second generation antipsychotic drugs differ is a matter of debate. OBJECTIVES: To evaluate the effects of zotepine compared with other second generation antipsychotic drugs for people suffering from schizophrenia and schizophrenia-like psychoses. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group Trials Register (November 2009), inspected references of all identified studies for further trials and contacted authors of trials for additional information. SELECTION CRITERIA: We included only randomised clinical controlled trials that compared zotepine with any forms of amisulpride, aripiprazole, clozapine, olanzapine, risperidone, sertindole or ziprasidone in people suffering from only schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: SS and KK extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. For continuous data, we calculated weighted mean differences (MD) again based on a random-effects model. MAIN RESULTS: We included three studies (total n=289; 2 RCTs zotepine vs clozapine; 1 RCT zotepine vs clozapine vs risperidone (at 4 mg, 8 mg doses) vs remoxipride. All studies were of limited methodological quality. When zotepine was compared with clozapine, it was clozapine that was found to be more effective in terms of global state (n=59, 1 RCT, RR No clinically significant response 8.23 CI 1.14 to 59.17). Mental state scores also favoured clozapine (n=59, 1 RCT, MD average score (BPRS total, high = poor) 6.00 CI 2.17 to 9.83) and there was less use of antiparkinson medication in the clozapine group (n=116, 2 RCTs, RR 20.96 CI 2.89 to 151.90). In the comparison of zotepine and risperidone, mental state scoring found no significant difference between the groups (vs 4 mg: n=40, 1 RCT, MD average endpoint score (BPRS total, high=poor) 1.40 CI -9.82 to 12.62; vs 8 mg: n=40, 1 RCT, MD -1.30 CI -12.95 to 10.35) and use of antiparkinson medication was equivocal (vs 4 mg: n=40, 1 RCT, MD 1.80 CI -0.64 to 4.24; vs 8 mg: n=40, 1 RCT, MD 2.50 CI -0.05 to 5.05). Finally, when zotepine was compared with remoxipride, again no effect was found for mental state (n=58, 1 RCT, MD average endpoint score (BPRS total, high=poor) 5.70 CI -4.13 to 15.53) and there was no significant difference between the two groups in terms of use of antiparkinson medication (n=49, 1 RCT, RR 0.97 CI 0.41 to 2.29).Data on important other outcomes such as other adverse events, service use or satisfaction with care, quality of life were not available. AUTHORS' CONCLUSIONS: The evidence base around zotepine is insufficient to provide firm conclusions on its absolute or relative effects. This is despite it being in use in Austria, France, Germany, Japan and the UK.


Assuntos
Antipsicóticos/uso terapêutico , Dibenzotiepinas/uso terapêutico , Esquizofrenia/tratamento farmacológico , Antipsicóticos/efeitos adversos , Clozapina/efeitos adversos , Clozapina/uso terapêutico , Dibenzotiepinas/efeitos adversos , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Remoxiprida/efeitos adversos , Remoxiprida/uso terapêutico , Risperidona/efeitos adversos , Risperidona/uso terapêutico
9.
Schizophr Res ; 123(2-3): 225-33, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20692814

RESUMO

OBJECTIVE: The metabolic side effects of second-generation antipsychotics (SGA) are serious and have not been compared head to head in a meta-analysis. We conducted a meta-analysis of studies comparing the metabolic side effects of the following SGAs head-to-head: amisulpride, aripiprazole, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone, zotepine. METHOD: We searched the register of the Cochrane schizophrenia group (last search May 2007), supplemented by MEDLINE and EMBASE (last search January 2009) for randomized, blinded studies comparing the above mentioned SGA in the treatment of schizophrenia or related disorders. At least three reviewers extracted the data independently. The primary outcome was weight change. We also assessed changes of cholesterol and glucose. The results were combined in a meta-analysis. RESULTS: We included 48 studies with 105 relevant arms. Olanzapine produced more weight gain than all other second-generation antipsychotics except for clozapine where no difference was found. Clozapine produced more weight gain than risperidone, risperidone more than amisulpride, and sertindole more than risperidone. Olanzapine produced more cholesterol increase than aripiprazole, risperidone and ziprasidone. (No differences with amisulpride, clozapine and quetiapine were found). Quetiapine produced more cholesterol increase than risperidone and ziprasidone. Olanzapine produced more increase in glucose than amisulpride, aripiprazole, quetiapine, risperidone and ziprasidone; no difference was found with clozapine. CONCLUSIONS: Some SGAs lead to substantially more metabolic side effects than other SGAs. When choosing an SGA for an individual patient these side effects with their potential cause of secondary diseases must be weighed against efficacy and characteristics of the individual patient.


Assuntos
Antipsicóticos/efeitos adversos , Glicemia/efeitos dos fármacos , Colesterol/sangue , Esquizofrenia/tratamento farmacológico , Aumento de Peso/efeitos dos fármacos , Amissulprida , Antipsicóticos/administração & dosagem , Aripiprazol , Benzodiazepinas/efeitos adversos , Ensaios Clínicos como Assunto , Clozapina/efeitos adversos , Dibenzotiazepinas/efeitos adversos , Humanos , Imidazóis/efeitos adversos , Indóis/efeitos adversos , Olanzapina , Piperazinas/efeitos adversos , Fumarato de Quetiapina , Quinolonas/efeitos adversos , Risperidona/efeitos adversos , Sulpirida/efeitos adversos , Sulpirida/análogos & derivados , Tiazóis/efeitos adversos
10.
Cochrane Database Syst Rev ; (3): CD006654, 2010 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-20238348

RESUMO

BACKGROUND: In many countries of the industrialised world second generation ("atypical") antipsychotics have become the first line drug treatment for people with schizophrenia. The question as to whether, and if so how much, the effects of the various second generation antipsychotics differ is a matter of debate. In this review we examined how the efficacy and tolerability of olanzapine differs from that of other second generation antipsychotics. OBJECTIVES: To evaluate the effects of olanzapine compared to other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychosis. SEARCH STRATEGY: 1. Electronic searching We searched the Cochrane Schizophrenia Group Trials Register (April 2007) which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO.2. Reference searching We inspected the reference of all identified studies for more trials.3. Personal contact We contacted the first author of each included study for missing information.4. Drug companies We contacted the manufacturers of all atypical antipsychotics included for additional data. SELECTION CRITERIA: We included all randomised trials that used at least single-blind (rater-blind) design, comparing oral olanzapine with oral forms of amisulpride, aripiprazole, clozapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine in people with schizophrenia or schizophrenia-like psychosis. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (WMD) again based on a random effects model. MAIN RESULTS: The review currently includes 50 studies and 9476 participants which provided data for six comparisons (olanzapine compared to amisulpride, aripiprazole, clozapine, quetiapine, risperidone or ziprasidone). The overall attrition from the included studies was considerable (49.2%) leaving the interpretation of results problematic.Olanzapine improved the general mental state (PANSS total score) more than aripiprazole (2 RCTs, n=794, WMD -4.96 CI -8.06 to -1.85), quetiapine (10 RCTs, n=1449, WMD -3.66 CI -5.39 to -1.93), risperidone (15 RCTs, n=2390, WMD -1.94 CI -3.31 to -0.58) and ziprasidone (4 RCTs, n=1291, WMD -8.32 CI -10.99 to -5.64), but not more than amisulpride or clozapine. This somewhat better efficacy was confirmed by fewer participants in the olanzapine groups leaving the studies early due to inefficacy of treatment compared to quetiapine (8 RCTs, n=1563, RR 0.56 CI 0.44 to 0.70, NNT 11 CI 6 to 50), risperidone (14 RCTs, n=2744, RR 0.78 CI 0.62 to 0.98, NNT 50 CI 17 to 100) and ziprasidone (5 RCTs, n=1937, RR 0.64 CI 0.51 to 0.79, NNT 17, CI 11 to 33).Fewer participants in the olanzapine group than in the quetiapine (2 RCTs, n=876, RR 0.56 CI 0.41 to 0.77, NNT 11 CI 7 to 25) and ziprasidone (2 RCTs, n=766, RR 0.65 CI 0.45 to 0.93, NNT 17 CI 9 to 100) treatment groups, but not in the clozapine group (1 RCT, n=980, RR 1.28 CI 1.02 to 1.61, NNH not estimable), had to be re-hospitalised in the trials.Except for clozapine, all comparators induced less weight gain than olanzapine (olanzapine compared to amisulpride: 3 RCTs, n=671, WMD 2.11kg CI 1.29kg to 2.94kg; aripiprazole: 1 RCT, n=90, WMD 5.60kg CI 2.15kg to 9.05kg; quetiapine: 7 RCTs, n=1173, WMD 2.68kg CI 1.10kg to 4.26kg; risperidone: 13 RCTs, n=2116, WMD 2.61kg CI 1.48kg to 3.74kg; ziprasidone: 5 RCTs, n=1659, WMD 3.82kg CI 2.96kg to 4.69kg). Associated problems such as glucose and cholesterol increase were usually also more frequent in the olanzapine group.Other differences in adverse effects were less well documented. Nevertheless, olanzapine may be associated with slightly more extrapyramidal side effects than quetiapine (use of antiparkinson medication (6 RCTs, n=1090, RR 2.05 CI 1.26 to 3.32, NNH 25 CI 14 to 100), but less than risperidone (use of antiparkinson medication 13 RCTs, n=2599, RR 0.78 CI 0.65 to 0.95, NNH 17 CI 9 to 100) and ziprasidone (use of antiparkinson medication 4 RCTs, n=1732, RR 0.70 CI 0.50 to 0.97, NNH not estimable). It may also increase prolactin somewhat more than aripiprazole, clozapine and quetiapine, but clearly less so than risperidone (6 RCTs, n=1291, WMD -22.84 CI -27.98 to -17.69). AUTHORS' CONCLUSIONS: Olanzapine may be a somewhat more efficacious drug than some other second generation antipsychotic drugs. This small superiority in efficacy needs to be weighed against a larger weight gain and associated metabolic problems than most other second generation antipsychotic drugs, except clozapine. These conclusions are tentative due to the large number of people leaving the studies early which possibly limits the validity of the findings. Further large, well-designed trials are necessary to establish the relative effects of different second generation antipsychotic drugs.


Assuntos
Antipsicóticos/uso terapêutico , Benzodiazepinas/uso terapêutico , Esquizofrenia/tratamento farmacológico , Amissulprida , Antipsicóticos/efeitos adversos , Aripiprazol , Clozapina/uso terapêutico , Dibenzotiazepinas/uso terapêutico , Humanos , Olanzapina , Piperazinas/uso terapêutico , Fumarato de Quetiapina , Quinolonas/uso terapêutico , Risperidona/uso terapêutico , Sulpirida/análogos & derivados , Sulpirida/uso terapêutico , Tiazóis/uso terapêutico
11.
Cochrane Database Syst Rev ; (1): CD006624, 2010 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-20091599

RESUMO

BACKGROUND: In many countries of the industrialised world second generation (atypical) antipsychotics have become first line drug treatments for people with schizophrenia. The question as to whether, and if so how much, the effects of the various second generation antipsychotics differ is a matter of debate. In this review we examine how the efficacy and tolerability of amisulpride differs from that of other second generation antipsychotics. OBJECTIVES: To evaluate the effects of amisulpride compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychoses. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group Trials Register (April 2007) which is based on regular searches of BIOSIS, CINAHL, EMBASE, MEDLINE and PsycINFO. SELECTION CRITERIA: We included randomised, at least single-blind, trials comparing oral amisulpride with oral forms of aripiprazole, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine in people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For continuous data we calculated weighted mean differences (MD), for dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. MAIN RESULTS: The review currently includes ten short to medium term trials with 1549 participants on three comparisons: amisulpride versus olanzapine, risperidone and ziprasidone. The overall attrition rate was considerable (34.7%) with no significant difference between groups. Amisulpride was similarly effective as olanzapine and risperidone and more effective than ziprasidone (leaving the study early due to inefficacy: n=123, 1 RCT, RR 0.21 CI 0.05 to 0.94, NNT 8 CI 5 to 50). Amisulpride induced less weight gain than risperidone (n=585, 3 RCTs, MD -0.99 CI -1.61 to -0.37) or olanzapine (n=671, 3 RCTs, MD -2.11 CI -2.94 to -1.29). Olanzapine was also associated with a higher increase of glucose (n=406, 2 RCTs, MD -7.30 CI -7.62 to -6.99). There was no difference in terms of cardiac effects and extra pyramidal symptoms (EPS) compared with olanzapine (akathisia: n= 587, 2 RCTs, RR 0.66 CI 0.36 to 1.21), compared with risperidone (akathisia: n=586, 3 RCTs, RR 0.80 CI 0.58 to 1.11) and compared with ziprasidone (akathisia: n=123, 1 RCT, RR 0.63, CI 0.11 to 3.67). AUTHORS' CONCLUSIONS: There is little randomised evidence comparing amisulpride with other second generation antipsychotic drugs. We could only find trials comparing amisulpride with olanzapine, risperidone and ziprasidone. We found amisulpride may be somewhat more effective than ziprasidone, and more tolerable in terms of weight gain and other associated problems than olanzapine and risperidone. These data, however, are based on only ten short to medium term studies and therefore too limited to allow for firm conclusions.


Assuntos
Antipsicóticos/uso terapêutico , Esquizofrenia/tratamento farmacológico , Sulpirida/análogos & derivados , Amissulprida , Antipsicóticos/efeitos adversos , Benzodiazepinas/efeitos adversos , Benzodiazepinas/uso terapêutico , Humanos , Olanzapina , Piperazinas/efeitos adversos , Piperazinas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Risperidona/efeitos adversos , Risperidona/uso terapêutico , Sulpirida/efeitos adversos , Sulpirida/uso terapêutico , Tiazóis/efeitos adversos , Tiazóis/uso terapêutico
12.
Cochrane Database Syst Rev ; (1): CD006628, 2010 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-20091601

RESUMO

BACKGROUND: In many countries of the industrialised world, second generation (atypical) antipsychotic drugs have become first line treatment for people with schizophrenia. The question as to whether the effects of various second generation antipsychotic drugs differ is a matter of debate. In this review we examined how the efficacy and tolerability of zotepine differs from that of other second generation antipsychotic drugs. OBJECTIVES: To evaluate the effects of zotepine compared with other second generation antipsychotic drugs for people with schizophrenia and schizophrenia-like psychoses. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group Trials Register (April 2007) which is based on regular searches of BIOSIS, CENTRAL CINAHL, EMBASE, MEDLINE and PsycINFO. SELECTION CRITERIA: We included all randomised trials comparing oral zotepine with oral forms of amisulpride, aripiprazole, clozapine, olanzapine, risperidone, sertindole or ziprasidone in people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (MD) again based on a random effects model. MAIN RESULTS: The review currently includes data from two short term, ill reported trials (total n=109). Both studies compared zotepine with clozapine. 34% of people left early but there was no significant difference between groups. Zotepine was less effective than clozapine (no clinically significant response: n=59, 1 RCT, RR 8.23 CI 1.14 to 59.17, NNH 3 CI 2 to 8; average score (BPRS total) at endpoint (n=59, 1 RCT, MD 6.00 CI 2.17 to 9.83). Zotepine induced more movement disorders than clozapine (use of antiparkinson medication: n=59, 1 RCT, RR 18.75 CI 1.17 to 301.08, NNH 3 CI 2 to 5) and higher prolactin levels (n=59, 1 RCT, MD 33.40 CI 14.87 to 51.93). Data on important other outcomes such as other adverse events, service use or satisfaction with care were not available. AUTHORS' CONCLUSIONS: Zotepine may be less effective than clozapine and associated with more movement disorders and higher prolactin levels, but the evidence base is too small and prone to bias, making any practical recommendations impossible. There is no randomised evidence on the effects of zotepine compared to second generation antipsychotic drugs other than clozapine. More studies are possible to justify.


Assuntos
Antipsicóticos/uso terapêutico , Dibenzotiepinas/uso terapêutico , Esquizofrenia/tratamento farmacológico , Antipsicóticos/efeitos adversos , Clozapina/efeitos adversos , Clozapina/uso terapêutico , Dibenzotiepinas/efeitos adversos , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto
13.
Cochrane Database Syst Rev ; (1): CD006625, 2010 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-20091600

RESUMO

BACKGROUND: In many countries of the industrialised world second generation ('atypical') antipsychotic drugs have become the first line drug treatment for people with schizophrenia. It is not clear how the effects of the various second generation antipsychotic drugs differ. OBJECTIVES: To evaluate the effects of quetiapine compared with other second generation antipsychotic drugs for people with schizophrenia and schizophrenia-like psychosis. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group Trials Register (April 2007), inspected references of all identified studies, and contacted relevant pharmaceutical companies, drug approval agencies and authors of trials for additional information. SELECTION CRITERIA: We included all randomised control trials comparing oral quetiapine with oral forms of amisulpride, aripiprazole, clozapine, olanzapine, risperidone, sertindole, ziprasidone or zotepine in people with schizophrenia or schizophrenia-like psychosis. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (WMD) again based on a random-effects model. MAIN RESULTS: The review currently includes 21 randomised control trials (RCTs) with 4101 participants. These trials provided data on four comparisons - quetiapine versus clozapine, olanzapine, risperidone or ziprasidone.A major limitation to all findings is the high number of participants leaving studies prematurely (57.6%) and the substantial risk of biases in studies. Efficacy data favoured olanzapine and risperidone compared with quetiapine (PANSS total score versus olanzapine:10 RCTs, n=1449, WMD 3.66 CI 1.93 to 5.39; versus risperidone: 9 RCTs, n=1953, WMD 3.09 CI 1.01 to 5.16), but clinical meaning is unclear. There were no clear mental state differences when quetiapine was compared with clozapine or ziprasidone.Compared with olanzapine, quetiapine produced slightly fewer movement disorders (6 RCTs, n=1090, RR use of antiparkinson medication 0.49 CI 0.3 to 0.79, NNH 25 CI 14 to 100) and less weight gain (7 RCTs, n=1173, WMD -2.81 CI -4.38 to -1.24) and glucose elevation, but more QTc prolongation (3 RCTs, n=643, WMD 4.81 CI 0.34 to 9.28). Compared with risperidone, quetiapine induced slightly fewer movement disorders (6 RCTs, n=1715, RR use of antiparkinson medication 0.5 CI 0.3 to 0.86, NNH 20 CI 10 to 100), less prolactin increase (6 RCTs, n=1731, WMD -35.28 CI -44.36 to -26.19) and some related adverse effects, but more cholesterol increase (5 RCTs, n=1433, WMD 8.61 CI 4.66 to 12.56). Compared with ziprasidone, quetiapine induced slightly fewer extrapyramidal adverse effects (1 RCT, n=522, RR use of antiparkinson medication 0.43 CI 0.2 to 0.93, NNH not estimable) and prolactin increase. On the other hand quetiapine was more sedating and led to more weight gain (2 RCTs, n=754, RR 2.22 CI 1.35 to 3.63, NNH 13 CI 8 to 33) and cholesterol increase than ziprasidone. AUTHORS' CONCLUSIONS: Best available evidence from trials suggests that most people who start quetiapine stop taking it within a few weeks. Comparisons with amisulpride, aripiprazole, sertindole and zotepine do not exist. Most data that has been reported within existing comparisons are of very limited value because of assumptions and biases within them. There is much scope for further research into the effects of this widely used drug.


Assuntos
Antipsicóticos/uso terapêutico , Dibenzotiazepinas/uso terapêutico , Esquizofrenia/tratamento farmacológico , Antipsicóticos/efeitos adversos , Benzodiazepinas/efeitos adversos , Benzodiazepinas/uso terapêutico , Clozapina/efeitos adversos , Clozapina/uso terapêutico , Dibenzotiazepinas/efeitos adversos , Humanos , Adesão à Medicação/estatística & dados numéricos , Olanzapina , Piperazinas/efeitos adversos , Piperazinas/uso terapêutico , Fumarato de Quetiapina , Ensaios Clínicos Controlados Aleatórios como Assunto , Risperidona/efeitos adversos , Risperidona/uso terapêutico , Tiazóis/efeitos adversos , Tiazóis/uso terapêutico
14.
Cochrane Database Syst Rev ; (4): CD006569, 2009 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-19821375

RESUMO

BACKGROUND: In many countries of the industrialised world second generation (atypical) antipsychotics have become first line drug treatments for people with schizophrenia. The question as to whether, and if so how much, the effects of the various second generation antipsychotics differ is a matter of debate. In this review we examine how the efficacy and tolerability of aripiprazole differs from that of other second generation antipsychotics. OBJECTIVES: To evaluate the effects of aripiprazole compared with other atypical antipsychotics for people with schizophrenia and schizophrenia-like psychoses. SEARCH STRATEGY: We searched the Cochrane Schizophrenia Group Trials Register (March 2007) which is based on regular searches of BIOSIS, CENTRAL, CINAHL, EMBASE, MEDLINE and PsycINFO. SELECTION CRITERIA: We included all randomised trials comparing oral aripiprazole with oral forms of amisulpride, clozapine, olanzapine, quetiapine, risperidone, sertindole, ziprasidone or zotepine in people with schizophrenia or schizophrenia-like psychoses. DATA COLLECTION AND ANALYSIS: We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis based on a random-effects model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (MD) again based on a random-effects model. MAIN RESULTS: The review currently includes four trials with 1404 participants on two out of eight possible comparisons - aripiprazole versus olanzapine and aripiprazole versus risperidone. The overall number of participants leaving the studies early was considerable (38.5%), limiting the validity of the findings, but with no significant differences between groups. Aripiprazole was less efficacious than olanzapine in terms of the general mental state (PANSS total score: n=794, 2 RCTs, MD 4.96 CI 1.85 to 8.06), but it was associated with fewer side-effects such as cholesterol increase, weight gain, sedation and prolactin associated side-effects. Compared with risperidone there was no difference in efficacy (PANSS total score: n=372, 2 RCTs, MD 1.50 CI -2.96 to 5.96). Dystonia, QTc abnormalities, prolactin and cholesterol increase were less frequent in the aripiprazole group, while tremor was more frequent in the aripiprazole group compared with those allocated risperidone. AUTHORS' CONCLUSIONS: Aripiprazole may be somewhat less effective than olanzapine, but more tolerable in terms of metabolic effects and sedation. There is no evidence for a difference in efficacy compared to risperidone, but for better tolerability in terms of dystonias, cholesterol prolactin increase and QTc prolongation. Randomised evidence comparing aripiprazole with other second generation antipsychotic drugs is currently not available.


Assuntos
Antipsicóticos/uso terapêutico , Piperazinas/uso terapêutico , Quinolonas/uso terapêutico , Esquizofrenia/tratamento farmacológico , Aripiprazol , Benzodiazepinas/uso terapêutico , Humanos , Olanzapina , Ensaios Clínicos Controlados Aleatórios como Assunto , Risperidona/uso terapêutico
15.
Am J Psychiatry ; 166(2): 152-63, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19015230

RESUMO

OBJECTIVE: Whether there are differences in efficacy among second-generation antipsychotics in the treatment of schizophrenia is a matter of heated debate. The authors conducted a systematic review and meta-analysis of blinded studies comparing second-generation antipsychotics head-to-head. METHOD: Searches of the Cochrane Schizophrenia Group's register (May 2007) and MEDLINE (September 2007) were conducted for randomized, blinded studies comparing two or more of nine second-generation antipsychotics in the treatment of schizophrenia. All data were extracted by at least three reviewers independently. The primary outcome measure was change in total score on the Positive and Negative Syndrome Scale; secondary outcome measures were positive and negative symptom subscores and rate of dropout due to inefficacy. The results were combined in a meta-analysis. Various sensitivity analyses and metaregressions were used to examine bias. RESULTS: The analysis included 78 studies with 167 relevant arms and 13,558 participants. Olanzapine proved superior to aripiprazole, quetiapine, risperidone, and ziprasidone. Risperidone was more efficacious than quetiapine and ziprasidone. Clozapine proved superior to zotepine and, in doses >400 mg/day, to risperidone. These differences were due to improvement in positive symptoms rather than negative symptoms. The results were rather robust with regard to the effects of industry sponsorship, study quality, dosages, and trial duration. CONCLUSIONS: The findings suggest that some second-generation antipsychotics may be somewhat more efficacious than others, but the limitations of meta-analysis must be considered. In tailoring drug treatment to the individual patient, small efficacy superiorities must be weighed against large differences in side effects and cost.


Assuntos
Antipsicóticos/uso terapêutico , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Antipsicóticos/efeitos adversos , Humanos , Escalas de Graduação Psiquiátrica , Ensaios Clínicos Controlados Aleatórios como Assunto , Esquizofrenia/diagnóstico , Resultado do Tratamento
16.
J Chem Theory Comput ; 4(11): 1949-58, 2008 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-26620337

RESUMO

The ability to measure scalar coupling constants across hydrogen bonds ((3h)JNC') from high-resolution NMR experiments allows the characterization of detailed structural properties of biomolecules. To analyze those, a parametrized model based on the linear combination of atomic orbitals relates H-bond geometries with the measured (3h)JNC' coupling magnitude. In the present study the dependence of calculated (3h)JNC' coupling constants on force field parameters is assessed. It is shown that increased polarity of the hydrogen bond improves the calculated (3h)JNC' coupling constants and shifts the conformational ensemble sampled from the molecular dynamics (MD) simulations toward the experimentally measured one. Increased charges lead to more narrow distance and angle distributions and improve the agreement between calculated and measured (3h)JNC' couplings. However, different secondary structures are better represented by different magnitudes of electrostatic interactions-different atomic partial charges in the present work-as indicated by root-mean square deviations (rsmds) between observed and calculated coupling constants (3h)JNC'. The parametrization of the empirical formula is found to be meaningful and robust, but the parameter values are not universal across different proteins and different secondary structural elements (α-helices, ß-sheets and loops). Using standard and slightly increased CHARMM charges, predictions for the as-yet unknown scalar coupling constants for the V54A and I6A mutants of protein G are made.

17.
J Mol Biol ; 374(5): 1270-85, 2007 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-17988687

RESUMO

Cyclic diguanosine monophosphate is a bacterial second messenger involved in a lifestyle switch from single cells to biofilm formation. Atomistic simulations are used to characterize inhibited diguanylate cyclase (DGC) PleD with emphasis on the feedback inhibition mechanism. Normal-mode calculations show a rigidification particularly in both the inhibition site and the active site of the protein upon ligand binding. Extensive molecular dynamics simulations in explicit solvent and analysis of the dynamical cross-correlation maps suggest two distinct coupling pathways between the active and the inhibition site: direct information transfer either through the beta-strands beta2 and beta3 of the DGC domain (pathway I) or via the disordered regions connecting domains D2 and DGC (pathway II). In addition, dynamical cross-correlation maps show differences in the correlation between neighboring domains upon ligand binding and upon the point mutation R390A. The correlated motions between domains D1 and D2, which form the dimerization interface, are stronger for free PleD. Complementary to the experimentally observed short-range interactions in ligated PleD, the present work also characterizes the long-range, delocalized interactions between domains that are important for understanding activation and allosteric control of the protein. Based on the results, experimental characterization of the point mutant R353 and of the double mutant N357/H394 is proposed to differentiate between pathways I and II.


Assuntos
Proteínas de Bactérias/química , GMP Cíclico/química , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , GMP Cíclico/metabolismo , Dimerização , Ligantes , Modelos Moleculares , Mutação Puntual , Ligação Proteica , Estrutura Secundária de Proteína
18.
J Am Chem Soc ; 129(18): 5898-903, 2007 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-17429967

RESUMO

NMR-observable scalar couplings across hydrogen bonds in nucleic acids and proteins present a quantitative measure for the geometry and--by the implicit experimental time averaging--dynamics of hydrogen bonds. We have carried out in-depth molecular dynamics (MD) simulations with various force fields on three proteins: ubiquitin, the GB1 domain of protein G, and the SMN Tudor domain, for which experimental h3JNC' scalar couplings of backbone hydrogen bonds and various high-resolution X-ray structures are available. Theoretical average values for h3JNC' were calculated from the snapshots of these MD simulations either by density functional theory or by a geometric parametrization (Barfield, M. J. Am. Chem. Soc. 2002, 124, 4158-4168). No significant difference was found between the two methods. The results indicate that time-averaging using explicit water solvation in the MD simulations improves significantly the agreement between experimental and theoretical values for the lower resolution structures ubiquitin (1.8 A), Tudor domain (1.8 A), and protein G (2.1 A). Only marginal improvement is found for the high-resolution structure (1.1 A) of protein G. Hence, experimental h3JNC' values are compatible with a static, high-resolution structural model. The MD averaging of the low-resolution structures moves the averages of the rHO distance and the H...O=C angle theta closer to their respective values in the high-resolution structures, thereby improving the agreement using experimental h3JNC' data. In contrast, MD averaging with implicit water models deteriorates the agreement with experiment for all proteins. The differing behavior can be explained by an artifactual lengthening of H-bonds caused by the implicit water models.


Assuntos
Proteínas/química , Ligação de Hidrogênio , Conformação Proteica , Água/química
19.
J Biol Chem ; 281(42): 32015-24, 2006 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-16923812

RESUMO

Cyclic di-guanosine monophosphate is a bacterial second messenger that has been implicated in biofilm formation, antibiotic resistance, and persistence of pathogenic bacteria in their animal host. Although the enzymes responsible for the regulation of cellular levels of c-di-GMP, diguanylate cyclases (DGC) and phosphodiesterases, have been identified recently, little information is available on the molecular mechanisms involved in controlling the activity of these key enzymes or on the specific interactions of c-di-GMP with effector proteins. By using a combination of genetic, biochemical, and modeling techniques we demonstrate that an allosteric binding site for c-di-GMP (I-site) is responsible for non-competitive product inhibition of DGCs. The I-site was mapped in both multi- and single domain DGC proteins and is fully contained within the GGDEF domain itself. In vivo selection experiments and kinetic analysis of the evolved I-site mutants led to the definition of an RXXD motif as the core c-di-GMP binding site. Based on these results and based on the observation that the I-site is conserved in a majority of known and potential DGC proteins, we propose that product inhibition of DGCs is of fundamental importance for c-di-GMP signaling and cellular homeostasis. The definition of the I-site binding pocket provides an entry point into unraveling the molecular mechanisms of ligand-protein interactions involved in c-di-GMP signaling and makes DGCs a valuable target for drug design to develop new strategies against biofilm-related diseases.


Assuntos
GMP Cíclico/química , Sítio Alostérico , Motivos de Aminoácidos , Sequência de Aminoácidos , Sítios de Ligação , Celulose/química , Cristalografia por Raios X , Escherichia coli/enzimologia , Proteínas de Escherichia coli , Retroalimentação Fisiológica , Dados de Sequência Molecular , Diester Fosfórico Hidrolases/química , Fósforo-Oxigênio Liases/química , Salmonella enterica/enzimologia , Transdução de Sinais
20.
Nanomedicine (Lond) ; 1(3): 373-8, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17716170

RESUMO

One of the predominant aims of insulin therapy for diabetes is to appropriately mimic physiological insulin secretion levels and their correlation with glucose concentration in healthy individuals. This report outlines current methods and their limitations in glycemic control and their possible relationship to insufficient knowledge about the structure and dynamics of the insulin hormone itself. Based on recent experimental and computational work, a possible approach to less-invasive insulin administration is sketched.


Assuntos
Insulina/uso terapêutico , Nanomedicina/métodos , Animais , Simulação por Computador , Dimerização , Humanos , Insulina/química , Insulina/farmacocinética , Modelos Moleculares , Nanomedicina/tendências , Nanopartículas/química
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