RESUMO
WHAT IS KNOWN ON THE SUBJECT?: Recently, concerns have been raised about how well United Kingdom National Health Service nurses care for their patients and their level of compassion. Motivational interviewing (MI) is an established approach to helping people make positive behaviour changes, through directive, person-centred counselling within a collaborative relationship between clinician and recipient. Based on evidence that MI may influence nursing practice positively, an investigation into the feasibility of training nurses on mental health inpatient rehabilitation wards ('rehabilitation') in MI to improve patient experience was reported. WHAT THIS PAPER ADDS TO EXISTING KNOWLEDGE?: This pilot study demonstrates that training rehabilitation nurses in MI is feasible and provides preliminary evidence suggesting that a larger study to examine efficacy is warranted, including a calculation of sample size required to draw robust statistical conclusions. Nurses evaluated the training as highly relevant to their work. Patients responded well to interviews and focus groups with support from experts-by-experience; they were generally fairly satisfied with the rehabilitation ward and slight improvements in their experience were found following MI training for nurses but not at 6-month follow-up. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: Rehabilitation nurses may face conflicting demands between ensuring patients with severe difficulties meet their basic needs and working with them to develop greater independence. Qualitative findings question whether nurse-patient interactions are fully valued as nursing interventions in inpatient rehabilitation. Learning MI might be a useful way of helping nurses think in detail about their interactions with patients and how to improve communications with their patients. The principles of MI should be incorporated into pre-registration training. ABSTRACT: Introduction There is limited research addressing the experiences of patients in inpatient rehabilitation (rehabilitation), who often spend long periods in hospital, and the nursing approaches utilized. Aim Based on evidence that motivational interviewing (MI) may improve nursing practice, this was a pilot study evaluating the feasibility of training rehabilitation nurses in MI and measuring patient experience. Method Nurses underwent training and supervision focusing on MI spirit. Quantitative and qualitative measures were taken pretraining, 2 months post-training and 8 months post-training. Expert-by-experience research assistants facilitated patients' participation in the study. Results This study showed that training rehabilitation nurses in MI was feasible and relevant to their work. Patients participated in interviews and focus groups with support and potential improvements that require further empirical investigation in patient experience were found following the MI training. Discussion This pilot study establishes the feasibility of a larger study addressing efficacy. Tentative qualitative findings question whether interactions between nurses and patients are valued in rehabilitation and support MI as a promising skill set for rehabilitation nurses. Implications for practice Bringing MI into inpatient rehabilitation provoked reflection on nursing practice. Dilemmas for nurses about balancing safety with promoting autonomy and communicating constructively with patients emerged as important.
Assuntos
Entrevista Motivacional/métodos , Satisfação do Paciente , Enfermagem Psiquiátrica/educação , Reabilitação Psiquiátrica/métodos , Adulto , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos PilotoRESUMO
Traditional response criteria in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML) are based on bone marrow morphology and may not accurately reflect clonal tumor burden in patients treated with non-cytotoxic chemotherapy. We used next-generation sequencing of serial bone marrow samples to monitor MDS and AML tumor burden during treatment with epigenetic therapy (decitabine and panobinostat). Serial bone marrow samples (and skin as a source of normal DNA) from 25 MDS and AML patients were sequenced (exome or 285 gene panel). We observed that responders, including those in complete remission (CR), can have persistent measurable tumor burden (that is, mutations) for at least 1 year without disease progression. Using an ultrasensitive sequencing approach, we detected extremely rare mutations (equivalent to 1 heterozygous mutant cell in 2000 non-mutant cells) months to years before their expansion at disease relapse. While patients can live with persistent clonal hematopoiesis in a CR or stable disease, ultimately we find evidence that expansion of a rare subclone occurs at relapse or progression. Here we demonstrate that sequencing of serial samples provides an alternative measure of tumor burden in MDS or AML patients and augments traditional response criteria that rely on bone marrow blast percentage.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Evolução Clonal/genética , Epigênese Genética/efeitos dos fármacos , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/tratamento farmacológico , Síndromes Mielodisplásicas/genética , Idoso , Idoso de 80 Anos ou mais , Medula Óssea/patologia , Exoma , Feminino , Genes p53 , Sequenciamento de Nucleotídeos em Larga Escala , Inibidores de Histona Desacetilases/administração & dosagem , Humanos , Leucemia Mieloide Aguda/diagnóstico , Masculino , Pessoa de Meia-Idade , Mutação , Síndromes Mielodisplásicas/diagnóstico , Polimorfismo de Nucleotídeo Único , Indução de Remissão , Resultado do Tratamento , Carga TumoralAssuntos
Histocompatibilidade , Transplante de Células-Tronco de Sangue Periférico/métodos , Transplante Haploidêntico/métodos , Adulto , Idoso , Feminino , Antígenos HLA/análise , Humanos , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/terapia , Masculino , Pessoa de Meia-Idade , Transplante de Células-Tronco de Sangue Periférico/mortalidade , Estudos Retrospectivos , Análise de Sobrevida , Linfócitos T , Transplante Haploidêntico/mortalidade , Adulto JovemRESUMO
Allogeneic stem cell transplantation (allo-SCT) outcomes in patients with Hodgkin lymphoma (HL) remain poorly defined. We performed a meta-analysis of allo-SCT studies in HL patients. The primary endpoints were 6-month, 1-year, 2-year and 3-year relapse-free survival (RFS) and overall survival (OS). A total of 42 reports (1850 patients) was included. The pooled estimates (95% confidence interval) for 6-month, 1-year, 2-year and 3-year RFS were 77 (59-91)%, 50 (42-57)%, 37 (31-43)% and 31 (25-37)%, respectively. The corresponding numbers for OS were 83 (75-91)%, 68 (62-74)%, 58 (52-64)% and 50 (41-58)%, respectively. There was statistical heterogeneity among studies in all outcomes. In meta-regression, accrual initiation year in 2000 or later was associated with higher 6-month (P=0.012) and 1-year OS (P=0.046), and pre-SCT remission with higher 2-year OS (P=0.047) and 1-year RFS (P=0.016). In conclusion, outcomes of allo-SCT in HL have improved over time, with 5-10% lower non-relapse mortality and relapse rates, and 15-20% higher RFS and OS in studies that initiated accrual in 2000 or later compared with earlier studies. However, there is no apparent survival plateau, demonstrating the need to improve on current allo-SCT strategies in relapsed/refractory HL.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Doença de Hodgkin/mortalidade , Doença de Hodgkin/terapia , Aloenxertos , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Fatores de Risco , Taxa de SobrevidaAssuntos
Doença Enxerto-Hospedeiro/diagnóstico por imagem , Neoplasias Hematológicas , Pelve/diagnóstico por imagem , Transplante de Células-Tronco , Tomografia Computadorizada por Raios X , Doença Aguda , Adulto , Aloenxertos , Feminino , Doença Enxerto-Hospedeiro/etiologia , Neoplasias Hematológicas/diagnóstico por imagem , Neoplasias Hematológicas/terapia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Autologous hematopoietic cell transplantation (AutoHCT) is a potentially curative treatment modality for relapsed/refractory Hodgkin lymphoma (HL). However, no large studies have evaluated pretransplant factors predictive of outcomes of AutoHCT in children, adolescents and young adults (CAYA, age <30 years). In a retrospective study, we analyzed 606 CAYA patients (median age 23 years) with relapsed/refractory HL who underwent AutoHCT between 1995 and 2010. The probabilities of PFS at 1, 5 and 10 years were 66% (95% confidence interval (CI): 62-70), 52% (95% CI: 48-57) and 47% (95% CI: 42-51), respectively. Multivariate analysis for PFS demonstrated that at the time of AutoHCT patients with Karnofsky/Lansky score ⩾90, no extranodal involvement and chemosensitive disease had significantly improved PFS. Patients with time from diagnosis to first relapse of <1 year had a significantly inferior PFS. A prognostic model for PFS was developed that stratified patients into low-, intermediate- and high-risk groups, predicting for 5-year PFS probabilities of 72% (95% CI: 64-80), 53% (95% CI: 47-59) and 23% (95% CI: 9-36), respectively. This large study identifies a group of CAYA patients with relapsed/refractory HL who are at high risk of progression after AutoHCT. Such patients should be targeted for novel therapeutic and/or maintenance approaches post-AutoHCT.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Doença de Hodgkin/terapia , Modelos Teóricos , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Causas de Morte , Criança , Pré-Escolar , Terapia Combinada , Progressão da Doença , Intervalo Livre de Doença , Feminino , Seguimentos , Doença de Hodgkin/tratamento farmacológico , Doença de Hodgkin/mortalidade , Doença de Hodgkin/radioterapia , Humanos , Masculino , Segunda Neoplasia Primária/epidemiologia , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Terapia de Salvação , Transplante Autólogo , Adulto JovemAssuntos
Transplante de Células-Tronco Hematopoéticas , Neoplasias Hepáticas/cirurgia , Linfoma de Células T/cirurgia , Neoplasias Esplênicas/cirurgia , Adolescente , Adulto , Idoso , Aloenxertos , Criança , Intervalo Livre de Doença , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Linfoma de Células T/mortalidade , Masculino , Pessoa de Meia-Idade , Neoplasias Esplênicas/mortalidade , Resultado do Tratamento , Adulto JovemAssuntos
Quimioterapia de Indução , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/terapia , Transplante de Células-Tronco , Adulto , Idoso , Aloenxertos , Autoenxertos , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
High-dose melphalan has been the standard conditioning regimen for auto-SCT in multiple myeloma (MM) for decades. A more effective conditioning regimen may induce deeper responses and longer remission duration. It is especially needed in the setting of second auto-SCT, which rarely achieves comparable results with the first auto-SCT using the same conditioning regimen. Here we conducted a phase II study to investigate the efficacy and safety of a conditioning regimen V-BEAM (bortezomib-BEAM) before second auto-SCT for multiple myeloma. Ten patients were enrolled from September 2012 to May 2013. The CR rate at day +100 after auto-SCT was 75%; all except for one patient remained in remission after a median follow-up of 6 months. Three patients developed Clostridium difficile infection. Two patients died within the first 30 days of auto-SCT from neutropenic colitis and overwhelming sepsis, respectively. Due to the high rate of morbidity and mortality, the study was terminated after 10 patients. In summary, although the conditioning regimen V-BEAM before second auto-SCT for MM provided promising responses, it was associated with unexpected treatment-related toxicity and should not be investigated further without modifications.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Ácidos Borônicos , Mieloma Múltiplo , Pirazinas , Transplante de Células-Tronco , Condicionamento Pré-Transplante , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Autoenxertos , Ácidos Borônicos/administração & dosagem , Ácidos Borônicos/efeitos adversos , Bortezomib , Carmustina/administração & dosagem , Carmustina/efeitos adversos , Citarabina/administração & dosagem , Citarabina/efeitos adversos , Feminino , Seguimentos , Humanos , Masculino , Melfalan/administração & dosagem , Melfalan/efeitos adversos , Pessoa de Meia-Idade , Mieloma Múltiplo/mortalidade , Mieloma Múltiplo/terapia , Podofilotoxina/administração & dosagem , Podofilotoxina/efeitos adversos , Pirazinas/administração & dosagem , Pirazinas/efeitos adversos , Condicionamento Pré-Transplante/efeitos adversos , Condicionamento Pré-Transplante/métodosAssuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Leucemia Mieloide Aguda/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Azacitidina/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Humanos , Lenalidomida , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Indução de Remissão , Talidomida/administração & dosagem , Talidomida/análogos & derivados , Adulto JovemRESUMO
BACKGROUND: Cytomegalovirus (CMV) infection is an important cause of morbidity and mortality after allogeneic hematopoietic stem cell transplant (HSCT). This pilot prospective randomized clinical trial compares valganciclovir (VGV) to ganciclovir (GCV) as pre-emptive therapy for CMV viremia in the post-allogeneic HSCT population. METHODS: Patients undergoing allogeneic HSCT who were at risk for CMV viremia were monitored post HSCT by weekly quantitative whole blood polymerase chain reaction. Pre-emptive therapy was delayed until the viral load (VL) was >10,000 copies/mL once, or >5000 copies/mL twice. Patients were randomized to either GCV 5 mg/kg twice a day (b.i.d.) for 7 days followed by daily GCV 5 mg/kg for up to 21 days, or VGV 900 mg b.i.d. for 7 days followed by 900 mg daily for up to 21 days. The primary endpoint was clearance of viremia (VL <5000 copies/mL) within 28 days of initiation of therapy. RESULT: In total, 37 patients were enrolled; 19 patients received treatment with VGV and 18 patients received treatment with GCV. The VGV was not inferior in efficacy to GCV as pre-emptive therapy, with rates of viral clearance at 28 days of 89.5% and 83%, respectively (P-value for non-inferiority = 0.030). Toxicities were similar between the 2 arms. No patients developed CMV disease. CONCLUSIONS: In this trial, the rates of clearance of viremia appear to be similar with VGV and GCV.
Assuntos
Antivirais/uso terapêutico , Infecções por Citomegalovirus/prevenção & controle , Ganciclovir/análogos & derivados , Ganciclovir/uso terapêutico , Transplante de Células-Tronco Hematopoéticas , Viremia/prevenção & controle , Administração Oral , Adolescente , Adulto , Antivirais/administração & dosagem , Citomegalovirus/efeitos dos fármacos , Infecções por Citomegalovirus/virologia , Relação Dose-Resposta a Droga , Feminino , Ganciclovir/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Reação em Cadeia da Polimerase , Estudos Prospectivos , Transplante Homólogo , Valganciclovir , Carga Viral/efeitos dos fármacos , Viremia/virologia , Adulto JovemRESUMO
Despite recent attempts at sub-categorization, including gene expression profiling into prognostically different groups of "germinal center B-cell type" and "activated B-cell type," diffuse large B-cell lymphoma (DLBCL) remains a biologically heterogenous tumor with no clear prognostic biomarkers to guide therapy. Whole genome, high resolution array comparative genomic hybridization (aCGH) was performed on four cases of chemoresistant DLBCL and four cases of chemo-responsive DLBCL to identify genetic differences that may correlate with response to rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) therapy. Array CGH analysis identified seven DNA copy number alteration (CNA) regions exclusive to the chemoresistant group, consisting of amplifications at 1p36.13, 1q42.3, 3p21.31, 7q11.23, and 16p13.3, as well as loss at 9p21.3 and 14p21.31. Copy number loss of the tumor suppressor genes CDKN2A (p16, p14) and CDKN2B (p15) at 9p21.3 was validated by fluorescence in situ hybridization and immunohistochemistry as independent techniques. In the chemo-sensitive group, 12 CNAs were detected consisting of segment gains on 1p36.11, 1p36.22, 2q11.2, 8q24.3, 12p13.33, and 22q13.2, as well as segment loss on 6p21.32. RUNX3, a tumor suppressor gene located on 1p36.11 and MTHFR, which encodes for the enzyme methylenetetrahydrofolate reductase, located on 1p36.22, are the only known genes in this group associated with lymphoma. Whole genome aCGH analysis has detected copy number alterations exclusive to either chemoresistant or chemoresponsive DLBCL that may represent consistent clonal changes predictive for prognosis and outcome of chemotherapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Hibridização Genômica Comparativa/métodos , Dosagem de Genes , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Adulto , Idoso , Variações do Número de Cópias de DNA , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Perfilação da Expressão Gênica , Genes p16 , Humanos , Hibridização in Situ Fluorescente , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos TestesRESUMO
The application of myeloablative Allo-SCT is limited by its associated morbidity and mortality. Reduced-intensity conditioning regimens attempt to diminish these, but are associated with a higher risk of disease relapse. Given the evidence of activity of clofarabine and cytarabine in myelodysplastic syndrome/acute myeloid leukemia (MDS/AML), we explored a novel reduced-intensity conditioning regimen based on this backbone. Patients received clofarabine 40 mg/m(2) i.v. on days -6 to -2, cytarabine 1 g/m(2) i.v. on days -6 to -2 and anti-thymocyte globulin (ATG) 1 mg/kg on day -4 and 2.5 mg/kg x 2 days on days -3 and -2. Seven patients were enrolled. Their median age was 54 years; three were with MDS and four with AML. The median duration of neutropenia was 14 days and that of thrombocytopenia was 22 days. Toxicities included hand-foot syndrome (57% grade 2), elevated alanine aminotransferase (ALT) (57% grade 3), elevated aspartate aminotransferase (AST) (86% grade 3) and hyperbilirubinemia (29% grade 3-5). No acute GVHD was observed. Enrollment to the trial was halted after three of the first seven patients expired on days +15, +26 and +32. Three of the four surviving patients have relapsed with a median TTP of 152 days. This regimen was not sufficiently immunosuppressive to ensure engraftment, and was associated with substantial morbidity and mortality.
Assuntos
Nucleotídeos de Adenina/administração & dosagem , Soro Antilinfocitário/administração & dosagem , Antimetabólitos Antineoplásicos/administração & dosagem , Arabinonucleosídeos/administração & dosagem , Citarabina/administração & dosagem , Imunossupressores/administração & dosagem , Leucemia Mieloide Aguda/terapia , Síndromes Mielodisplásicas/terapia , Transplante de Células-Tronco , Condicionamento Pré-Transplante/métodos , Nucleotídeos de Adenina/efeitos adversos , Adulto , Idoso , Soro Antilinfocitário/efeitos adversos , Antimetabólitos Antineoplásicos/efeitos adversos , Arabinonucleosídeos/efeitos adversos , Clofarabina , Citarabina/efeitos adversos , Intervalo Livre de Doença , Feminino , Humanos , Imunossupressores/efeitos adversos , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/mortalidade , Taxa de Sobrevida , Fatores de Tempo , Transplante HomólogoRESUMO
Currently, granulocyte colony stimulating factor (G-CSF) remains the standard mobilizing agent for peripheral blood stem cell (PBSC) donors, allowing the safe collection of adequate PBSCs from the vast majority of donors. However, G-CSF mobilization can be associated with some significant side effects and requires a multi-day dosing regimen. The other cytokine approved for stem cell mobilization, granulocyte-macrophage colony stimulating factor (GM-CSF), alters graft composition and may reduce the development of graft-versus-host disease, but a significant minority of donors fails to provide sufficient CD34+ cells with GM-CSF and some experience unacceptable toxicity. AMD3100 is a promising new mobilizing agent, which may have several advantages over G-CSF for donor mobilization. As it is a direct antagonist of the interaction between the chemokine stromal-derived factor-1 and its receptor CXCR4, AMD3100 mobilizes PBSCs within hours rather than days. It is also well tolerated, with no significant side effects reported in any of the clinical trials to date. Studies of autologous and allogeneic transplantation of AMD3100 mobilized grafts have demonstrated prompt and stable engraftment. Here, we review the current state of stem cell mobilization in normal donors and discuss novel strategies for donor stem cell mobilization.
Assuntos
Fator Estimulador de Colônias de Granulócitos/farmacologia , Mobilização de Células-Tronco Hematopoéticas/métodos , Benzilaminas , Transplante de Medula Óssea , Ciclamos , Fator Estimulador de Colônias de Granulócitos/efeitos adversos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/efeitos adversos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Mobilização de Células-Tronco Hematopoéticas/efeitos adversos , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Compostos Heterocíclicos/efeitos adversos , Compostos Heterocíclicos/farmacologia , Humanos , Proteínas Recombinantes , Segurança , Doadores de Tecidos , Transplante HomólogoRESUMO
Individuals affected with neurofibromatosis 1 (NF1) harbor increased numbers of GFAP-immunoreactive cerebral astrocytes and develop astrocytomas that can lead to blindness and death. Mice heterozygous for a targeted Nf1 mutation (Nf1+/-) were employed as a model for the human disease to evaluate the hypothesis that reduced NF1 protein (neurofibromin) expression may confer a growth advantage for astrocytes, such that inactivation of only one NF1 allele is sufficient for abnormal astrocyte proliferation. Here, we report that Nf17+/- mice have increased numbers of cerebral astrocytes and increased astrocyte proliferation compared to wild-type littermates. Intriguingly, primary Nf1+/- astrocyte cultures failed to demonstrate a cell-autonomous growth advantage unless they were cocultured with C17 neuronal cells. This C17 neuronal cell-induced Nf1+/- increase in proliferation was blocked by MEK inhibition (PD98059), suggesting a p21-ras-dependent effect. Furthermore, mice heterozygous for a targeted mutation in another GAP molecule, p120-GAP, demonstrated no increases in cerebral astrocyte number. These findings suggest that reduced NF1 expression results in a cell context-dependent increase in astrocyte proliferation that may be sufficient for the development of astrocytic growth abnormalities in patients with NF1.
Assuntos
Astrócitos/citologia , Genes da Neurofibromatose 1 , Neurônios/citologia , Proteínas/genética , Proteínas/metabolismo , Animais , Astrócitos/fisiologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Técnicas de Cocultura , Inibidores Enzimáticos/farmacologia , Flavonoides/farmacologia , Proteína Glial Fibrilar Ácida/análise , Heterozigoto , Humanos , Camundongos , Camundongos Mutantes , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neurofibromatose 1/genética , Neurofibromatose 1/patologia , Neurofibromina 1 , Neurônios/fisiologiaRESUMO
Multiple pharmacologic agents were used in attempt to relieve a constant and severe headache in a 47-year-old patient following craniotomy for removal of an acoustic neuroma. Possible etiologies for the unremitting headache are presented. Response to various pharmacologic agents are listed and discussed. During the postoperative course of two surgeries on this patient, it was possible to propose an etiology for the headache by analyzing the mechanisms of each therapeutic agent, along with the patient's response. Divalproex sodium provided complete relief, suggesting the headache is attributable to cell membrane instability.