Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Age Ageing ; 52(5)2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37247404

RESUMO

BACKGROUND: potentially harmful polypharmacy is very common in older people living in aged care facilities. To date, there have been no double-blind randomised controlled studies of deprescribing multiple medications. METHODS: three-arm (open intervention, blinded intervention and blinded control) randomised controlled trial enrolling people aged over 65 years (n = 303, noting pre-specified recruitment target of n = 954) living in residential aged care facilities. The blinded groups had medications targeted for deprescribing encapsulated while the medicines were deprescribed (blind intervention) or continued (blind control). A third open intervention arm had unblinded deprescribing of targeted medications. RESULTS: participants were 76% female with mean age 85.0 ± 7.5 years. Deprescribing was associated with a significant reduction in the total number of medicines used per participant over 12 months in both intervention groups (blind intervention group -2.7 medicines, 95% CI -3.5, -1.9, and open intervention group -2.3 medicines; 95% CI -3.1, -1.4) compared with the control group (-0.3, 95% CI -1.0, 0.4, P = 0.053). Deprescribing regular medicines was not associated with any significant increase in the number of 'when required' medicines administered. There were no significant differences in mortality in the blind intervention group (HR 0.93, 95% CI 0.50, 1.73, P = 0.83) or the open intervention group (HR 1.47, 95% CI 0.83, 2.61, P = 0.19) compared to the control group. CONCLUSIONS: deprescribing of two to three medicines per person was achieved with protocol-based deprescribing during this study. Pre-specified recruitment targets were not met, so the impact of deprescribing on survival and other clinical outcomes remains uncertain.


Assuntos
Desprescrições , Idoso Fragilizado , Idoso , Humanos , Feminino , Idoso de 80 Anos ou mais , Masculino , Instituição de Longa Permanência para Idosos , Método Duplo-Cego , Polimedicação , Avaliação de Resultados em Cuidados de Saúde , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Breast Cancer Res ; 20(1): 19, 2018 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-29566726

RESUMO

BACKGROUND: Early-onset breast cancer (EOBC) affects about one in 300 women aged 40 years or younger and is associated with worse outcomes than later onset breast cancer. This study explored novel serum proteins as surrogate markers of prognosis in patients with EOBC. METHODS: Serum samples from EOBC patients (stages 1-3) were analysed using agnostic high-precision quantitative proteomics. Patients received anthracycline-based chemotherapy. The discovery cohort (n = 399) either had more than 5-year disease-free survival (DFS) (good outcome group, n = 203) or DFS of less than 2 years (poor outcome group, n = 196). Expressed proteins were assessed for differential expression between the two groups. Bioinformatics pathway and network analysis in combination with literature research were used to determine clinically relevant proteins. ELISA analysis against an independent sample set from the Prospective study of Outcomes in Sporadic versus Hereditary breast cancer (POSH) cohort (n = 181) was used to validate expression levels of the selected target. Linear and generalized linear modelling was applied to determine the effect of target markers, body mass index (BMI), lymph node involvement (LN), oestrogen receptor (ER), progesterone receptor and human epidermal growth factor receptor 2 status on patients' outcome. RESULTS: A total of 5346 unique proteins were analysed (peptide FDR p ≤ 0.05). Of these, 812 were differentially expressed in the good vs poor outcome groups and showed significant enrichment for the insulin signalling (p = 0.01) and the glycolysis/gluconeogenesis (p = 0.01) pathways. These proteins further correlated with interaction networks involving glucose and fatty acid metabolism. A consistent nodal protein to these metabolic networks was resistin (upregulated in the good outcome group, p = 0.009). ELISA validation demonstrated resistin to be upregulated in the good outcome group (p = 0.04), irrespective of BMI and ER status. LN involvement was the only covariate with a significant association with resistin measurements (p = 0.004). An ancillary in-silico observation was the induction of the inflammatory response, leucocyte infiltration, lymphocyte migration and recruitment of phagocytes (p < 0.0001, z-score > 2). Survival analysis showed that resistin overexpression was associated with improved DFS. CONCLUSIONS: Higher circulating resistin correlated with node-negative patients and longer DFS independent of BMI and ER status in women with EOBC. Overexpression of serum resistin in EOBC may be a surrogate indicator of improved prognosis.


Assuntos
Proteínas Sanguíneas/genética , Neoplasias da Mama/sangue , Proteômica , Resistina/sangue , Adulto , Biomarcadores Tumorais/sangue , Índice de Massa Corporal , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Resistência à Insulina , Linfonodos/patologia , Células Neoplásicas Circulantes/patologia , Prognóstico , Receptores de Estrogênio/genética , Receptores de Progesterona/genética
3.
Blood ; 124(20): 3101-9, 2014 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-25170122

RESUMO

B-cell receptor (BCR) signaling plays a key role in the behavior of chronic lymphocytic leukemia (CLL). However, cellular consequences of signaling are incompletely defined. Here we explored possible links between BCR signaling and the unfolded protein response (UPR), a stress response pathway that can promote survival of normal and malignant cells. Compared with normal B cells, circulating CLL cells expressed increased, but variable, levels of UPR components. Higher expression of CHOP and XBP1 RNAs was associated with more aggressive disease. UPR activation appeared due to prior tissue-based antigenic stimulation because elevated expression of UPR components was detected within lymph node proliferation centers. Basal UPR activation also correlated closely with surface immunoglobulin M (sIgM) signaling capacity in vitro in both IGHV unmutated CLL and within mutated CLL. sIgM signaling increased UPR activation in vitro with responders showing increased expression of CHOP and XBP1 RNAs, and PERK and BIP proteins, but not XBP1 splicing. Inhibitors of BCR-associated kinases effectively prevented sIgM-induced UPR activation. Overall, this study demonstrates that sIgM signaling results in activation of some components the UPR in CLL cells. Modulation of the UPR may contribute to variable clinical behavior, and its inhibition may contribute to clinical responses to BCR-associated kinase inhibitors.


Assuntos
Linfócitos B/imunologia , Imunoglobulina M/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Leucemia Linfocítica Crônica de Células B/imunologia , Proteínas Tirosina Quinases/imunologia , Receptores de Antígenos de Linfócitos B/imunologia , Resposta a Proteínas não Dobradas , Tirosina Quinase da Agamaglobulinemia , Linfócitos B/patologia , Humanos , Leucemia Linfocítica Crônica de Células B/patologia , Transdução de Sinais , Quinase Syk
4.
Br J Clin Pharmacol ; 82(3): 583-623, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27077231

RESUMO

AIMS: Deprescribing is a suggested intervention to reverse the potential iatrogenic harms of inappropriate polypharmacy. The review aimed to determine whether or not deprescribing is a safe, effective and feasible intervention to modify mortality and health outcomes in older adults. METHODS: Specified databases were searched from inception to February 2015. Two researchers independently screened all retrieved articles for inclusion, assessed study quality and extracted data. Data were pooled using RevMan v5.3. Eligible studies included those where older adults had at least one medication deprescribed. The primary outcome was mortality. Secondary outcomes were adverse drug withdrawal events, psychological and physical health outcomes, quality of life, and medication usage (e.g. successful deprescribing, number of medications prescribed, potentially inappropriate medication use). RESULTS: A total of 132 papers met the inclusion criteria, which included 34 143 participants aged 73.8 ± 5.4 years. In nonrandomized studies, deprescribing polypharmacy was shown to significantly decrease mortality (OR 0.32, 95% CI: 0.17-0.60). However, this was not statistically significant in the randomized studies (OR 0.82, 95% CI 0.61-1.11). Subgroup analysis revealed patient-specific interventions to deprescribe demonstrated a significant reduction in mortality (OR 0.62, 95% CI 0.43-0.88). However, generalized educational programmes did not change mortality (OR 1.21, 95% CI 0.86-1.69). CONCLUSIONS: Although nonrandomized data suggested that deprescribing reduces mortality, deprescribing was not shown to alter mortality in randomized studies. Mortality was significantly reduced when applying patient-specific interventions to deprescribe in randomized studies.


Assuntos
Desprescrições , Prescrição Inadequada/efeitos adversos , Prescrição Inadequada/mortalidade , Humanos , Polimedicação
5.
Vet Radiol Ultrasound ; 57(5): 467-74, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27377036

RESUMO

Tooth resorption is the most common dental disease in cats and can be a source of oral pain. The current clinical gold standard for diagnosis includes a combination of oral exam and dental radiography, however early lesions are not always detected. Computed tomography (CT) of the skull, including the dental arches, is a commonly performed diagnostic procedure, however the appearance of tooth resorption on CT and the diagnostic ability of CT to detect tooth resorption have not been evaluated. The purpose of this prospective, descriptive, diagnostic accuracy study was to characterize the CT appearance of tooth resorption in a sample of affected cats and to evaluate the sensitivity and specificity of CT for tooth resorption compared to the clinical gold standard of oral exam and intraoral dental radiography. Twenty-eight cat cadaver specimens were recruited for inclusion. Each specimen was evaluated using oral exam, intraoral dental radiography, and computed tomography (four different slice thicknesses). Each tooth was evaluated for the presence or absence of tooth resorption. Teeth with lesions and a subset of normal teeth were evaluated with histopathology. On CT, tooth resorption appeared as irregularly marginated hypoattenuating defects in the mineral attenuating tooth components, most commonly involving the root or cementoenamel junction. Sensitivity for CT detection of tooth resorption was fair to poor (42.2-57.7%) and specificity was good to excellent (92.8-96.3%). Findings from this study indicated that CT has high specificity but low sensitivity for detection of tooth resorption in cats.


Assuntos
Doenças do Gato/diagnóstico por imagem , Tomografia Computadorizada por Raios X/veterinária , Reabsorção de Dente/veterinária , Animais , Doenças do Gato/etiologia , Gatos , Estudos Prospectivos , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos , Reabsorção de Dente/diagnóstico por imagem
6.
Blood ; 119(1): 170-9, 2012 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-22086413

RESUMO

Although long considered as a disease of failed apoptosis, it is now clear that chronic lymphocytic leukemia (CLL) cells undergo extensive cell division in vivo, especially in progressive disease. Signaling via the B-cell receptor is thought to activate proliferation and survival pathways in CLL cells and also has been linked to poor outcome. Here, we have analyzed the expression of the proto-oncoprotein MYC, an essential positive regulator of the cell cycle, after stimulation of surface IgM (sIgM). MYC expression was rapidly increased after sIgM stimulation in a subset of CLL samples. The ability of sIgM stimulation to increase MYC expression was correlated with sIgM-induced intracellular calcium fluxes. MYC induction was partially dependent on the MEK/ERK signaling pathway, and MYC and phosphorylated ERK1/2 were both expressed within proliferation centers in vivo. Although stimulation of sIgD also resulted in ERK1/2 phosphorylation, responses were relatively short lived compared with sIgM and were associated with significantly reduced MYC induction, suggesting that the kinetics of ERK1/2 activation is a critical determinant of MYC induction. Our results suggest that ERK1/2-dependent induction of MYC is likely to play an important role in antigen-induced CLL cell proliferation.


Assuntos
Membrana Celular/metabolismo , Imunoglobulina M/metabolismo , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/metabolismo , MAP Quinase Quinase 1/metabolismo , MAP Quinase Quinase 2/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Western Blotting , Ciclo Celular , Proliferação de Células , Humanos , Técnicas Imunoenzimáticas , Leucemia Linfocítica Crônica de Células B/genética , MAP Quinase Quinase 1/genética , MAP Quinase Quinase 2/genética , Proteína Quinase 1 Ativada por Mitógeno/genética , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/genética , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Células Tumorais Cultivadas
7.
Blood ; 119(9): 2106-9, 2012 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-22234701

RESUMO

IGHV1-69/51p1 is expressed by ∼ 30% of unmutated chronic lymphocytic leukemia (U-CLL) and combines with selected IGHD and IGHJ genes generating stereotypes if HCDR3 amino acid homology is > 60%. We had previously revealed stereotypic IGHV1-69/IGHJ6 rearrangements in normal naive B cells, thereby identifying potential counterparts of U-CLL. A different stereotypic IGHV1-69/IGHD3-16(RF2)/IGHJ3 rearrangement carrying the CAR(GGx)YD motif in the N1-region, recurrent in 6% IGHV1-69+ve CLL, is exceptionally sequence restricted, strongly suggestive of shared antigen recognition. We have now analyzed IGHV1-69/IGHJ3 rearrangements in circulating B cells of healthy individuals using several PCR-based approaches with IGHV1-69/IGHJ3 CLL sequences for reference. Stereotypes were found, but all were distinct from CLL. Remarkably, even a highly sensitive semi-nested PCR, specific for the CLL-expressed IGHV1-69/IGHD3-16(RF2)/IGHJ3 stereotype, failed to identify the CAR(GGx)YD sequence, although similar motifs were found. These highly specific B cells are not apparent in the accessible normal repertoire and may expand in response to rarely expressed antigens important in the pathogenesis of CLL.


Assuntos
Linfócitos B/metabolismo , Rearranjo Gênico de Cadeia Pesada de Linfócito B/genética , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Leucemia Linfocítica Crônica de Células B/genética , Recombinação V(D)J/genética , Sequência de Aminoácidos , Humanos , Alinhamento de Sequência
8.
Blood ; 119(7): 1726-36, 2012 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-22160382

RESUMO

B-cell receptor and microenvironment-derived signals promote accumulation of chronic lymphocytic leukemia (CLL) cells through increased proliferation and/or decreased apoptosis. In this study, we investigated the regulation of BIM, a proapoptotic BCL2-related protein, which is tightly regulated by phosphorylation. Surface IgM stimulation increased phosphorylation of 2 BIM isoforms, BIM(EL) and BIM(L), in a subset of CLL samples. In contrast, in normal B cells, anti-IgM triggered selective phosphorylation of BIM(EL) only. In CLL, anti-IgM-induced BIM phosphorylation correlated with unmutated IGHV gene status and with progressive disease. Strikingly, it was also associated with progressive disease within the mutated IGHV gene subset. BIM phosphorylation was dependent on MEK1/2 kinase activity, and we identified BIM(EL) serine 69, previously linked to pro-survival responses, as the major site of phosphorylation in CLL and in Ramos cells. BIM(EL)/BIM(L) phosphorylation was associated with release of the pro-survival protein MCL1. Coculture of CLL cells with HK cells, a model of the CLL microenvironment, promoted CLL cell survival and was associated with MEK1/2 activation and BIM(EL) phosphorylation. Hence, BIM phosphorylation appears to play a key role in apoptosis regulation in CLL cells, potentially coordinating antigen and microenvironment-derived survival signals. Antigen-mediated effects on BIM may be an important determinant of clinical behavior.


Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Anticorpos Anti-Idiotípicos/farmacologia , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/fisiologia , Proteína 11 Semelhante a Bcl-2 , Biomarcadores Tumorais/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Ativação Enzimática , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/fisiologia , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Fosforilação/efeitos dos fármacos , Prognóstico , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteólise/efeitos dos fármacos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/fisiologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
9.
J Am Med Dir Assoc ; 25(6): 104944, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38428832

RESUMO

OBJECTIVE: We aimed to explore medicines regimens charted for older people living in residential aged care facilities (RACFs). DESIGN: Repeated cross-sectional study using routinely collected data sampled in a cross-sectional manner at 11 time points (day of admission, then at 1, 3, 7, 14, and 30 days, and 3, 6, 12, 18, and 24 months post admission). SETTING AND PARTICIPANTS: The cohort is set in 34 RACFs managed by a single Australasian provider. People aged ≥65 years admitted to permanent care between January 1, 2017, and October 1, 2021, with medicines charted on the date of admission. METHODS: Medicines charted were evaluated for potentially suboptimal prescribing including number of medicines, high-risk prescribing (eg, potentially inappropriate medicines, anticholinergic burden), and potential underprescribing. RESULTS: The 3802 residents in the final cohort had a mean age of 84.9 ± 7.2 years at admission. At least 1 example of suboptimal prescribing was identified in 3479 (92%) residents at admission increasing to 1410 (97%) at 24 months. The number of medicines charted for each resident increased over time from 6.0 ± 3.8 regular and 2.8 ± 2.7 as required medicines at admission to 8.9 ± 4.1 regular and 8.1 ± 3.7 as required medicines at 24 months. Anticholinergic drug burden increased from 1.6 ± 2.4 at admission to 3.0 ± 2.8 at 24 months. Half the residents (2173; 57%) used at least 1 potentially inappropriate medicine at admission, which rose to nearly three-quarters (1060; 73%) at 24 months admission. CONCLUSION AND IMPLICATIONS: The total number of medicines charted for older adults living in RACFs increases with length of stay, with charted as required medicines nearly tripling. Effective interventions to optimize medicines use in this vulnerable population are required.


Assuntos
Prescrição Inadequada , Humanos , Estudos Transversais , Feminino , Masculino , Idoso de 80 Anos ou mais , Idoso , Prescrição Inadequada/estatística & dados numéricos , Instituição de Longa Permanência para Idosos/estatística & dados numéricos , Polimedicação , Lista de Medicamentos Potencialmente Inapropriados , Austrália , Casas de Saúde
10.
J Am Med Dir Assoc ; 25(3): 539-544.e2, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38307120

RESUMO

OBJECTIVES: The structured, clinically supervised withdrawal of medicines, known as deprescribing, is one strategy to address inappropriate polypharmacy. This study aimed to evaluate the costs and consequences of deprescribing in frail older people living in residential aged care facilities (RACFs) in Australia. DESIGN: A within-trial cost-consequence analysis of a deprescribing intervention-Opti-Med. The Opti-Med double-blind randomized controlled trial of deprescribing included 3 groups: blinded control, blinded intervention, and an open intervention group. SETTING AND PARTICIPANTS: Seventeen RACFs in Western Australia and New South Wales. Participants were 303 older people living in participating RACFs from March 2014 to February 2019. METHODS: Analysis was conducted from the health sector perspective. Health economic outcomes assessed include cost saved from deprescribed medicines and the incremental quality-adjusted life-years. Costs were presented in 2022 Australian dollars. RESULTS: The total cost of the Opti-Med intervention was $239.13 per participant. The costs saved through deprescribed medicines over 12 months after adjusting for mortality within the trial period was $328.90 per participant in the blinded intervention group and $164.00 per participant in the open intervention group. On average, the cost of the intervention was more than offset by the cost saved from deprescribed medicines. Extrapolating these findings to the Australian population suggests a potential net cost saving of about $1 to $16 million per annum for the health system nationally. The incremental quality-adjusted life-years were very similar across the 3 groups within the trial period. CONCLUSIONS AND IMPLICATIONS: Deprescribing for frail older people living in RACFs can be a cost-saving intervention without reducing the quality of life. Systemwide implementation of deprescribing across RACFs in Australia has the potential to improve health care delivery through the cost savings, which could be reapplied to further optimize care within RACFs.


Assuntos
Desprescrições , Humanos , Idoso , Austrália , Idoso Fragilizado , Qualidade de Vida , Redução de Custos , Avaliação de Resultados em Cuidados de Saúde
11.
Blood ; 118(9): 2530-40, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21768293

RESUMO

The anti-CD20 mAb rituximab is central to the treatment of B-cell malignancies, but resistance remains a significant problem. We recently reported that resistance could be explained, in part, by internalization of rituximab (type I anti-CD20) from the surface of certain B-cell malignancies, thus limiting engagement of natural effectors and increasing mAb consumption. Internalization of rituximab was most evident in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL), but the extent of internalization was heterogeneous within each disease. Here, we show that the inhibitory FcγRIIb on target B cells promotes this process and is largely responsible for the observed heterogeneity across a range of B-cell malignancies. Internalization correlated strongly with FcγRIIb expression on normal and malignant B cells, and resulted in reduced macrophage phagocytosis of mAb-coated targets. Furthermore, transfection of FcγRIIb into FcγRIIb negative Ramos cells increased internalization of rituximab in a dose-dependent manner. Target-cell FcγRIIb promoted rituximab internalization in a cis fashion and was independent of FcγRIIb on neighboring cells. It became phosphorylated and internalized along with CD20:anti-CD20 complexes before lysosomal degradation. In MCL patients, high FcγRIIb expression predicted less durable responses after rituximab-containing regimens. Therefore, target-cell FcγRIIb provides a potential biomarker of response to type I anti-CD20 mAb.


Assuntos
Anticorpos Monoclonais Murinos/metabolismo , Anticorpos Antineoplásicos/metabolismo , Complexo Antígeno-Anticorpo/metabolismo , Antígenos CD20/metabolismo , Antígenos de Neoplasias/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linfócitos B/imunologia , Resistencia a Medicamentos Antineoplásicos/fisiologia , Endocitose/fisiologia , Linfoma de Célula do Manto/tratamento farmacológico , Receptores de IgG/metabolismo , Anticorpos Monoclonais Murinos/administração & dosagem , Anticorpos Monoclonais Murinos/imunologia , Anticorpos Antineoplásicos/administração & dosagem , Anticorpos Antineoplásicos/imunologia , Antígenos CD20/imunologia , Antígenos de Neoplasias/imunologia , Linfócitos B/metabolismo , Biomarcadores , Linhagem Celular Tumoral/imunologia , Linhagem Celular Tumoral/metabolismo , Humanos , Leucemia Linfocítica Crônica de Células B/imunologia , Leucemia Linfocítica Crônica de Células B/patologia , Linfoma de Células B/imunologia , Linfoma de Células B/patologia , Linfoma de Célula do Manto/patologia , Lisossomos/metabolismo , Macrófagos/fisiologia , Fagocitose , Fosforilação , Processamento de Proteína Pós-Traducional , Receptores de IgG/genética , Proteínas Recombinantes de Fusão/metabolismo , Rituximab , Transfecção , Resultado do Tratamento
12.
J Anim Ecol ; 82(3): 518-28, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23398603

RESUMO

1. Bighorn sheep mortality related to pneumonia is a primary factor limiting population recovery across western North America, but management has been constrained by an incomplete understanding of the disease. We analysed patterns of pneumonia-caused mortality over 14 years in 16 interconnected bighorn sheep populations to gain insights into underlying disease processes. 2. We observed four age-structured classes of annual pneumonia mortality patterns: all-age, lamb-only, secondary all-age and adult-only. Although there was considerable variability within classes, overall they differed in persistence within and impact on populations. Years with pneumonia-induced mortality occurring simultaneously across age classes (i.e. all-age) appeared to be a consequence of pathogen invasion into a naïve population and resulted in immediate population declines. Subsequently, low recruitment due to frequent high mortality outbreaks in lambs, probably due to association with chronically infected ewes, posed a significant obstacle to population recovery. Secondary all-age events occurred in previously exposed populations when outbreaks in lambs were followed by lower rates of pneumonia-induced mortality in adults. Infrequent pneumonia events restricted to adults were usually of short duration with low mortality. 3. Acute pneumonia-induced mortality in adults was concentrated in fall and early winter around the breeding season when rams are more mobile and the sexes commingle. In contrast, mortality restricted to lambs peaked in summer when ewes and lambs were concentrated in nursery groups. 4. We detected weak synchrony in adult pneumonia between adjacent populations, but found no evidence for landscape-scale extrinsic variables as drivers of disease. 5. We demonstrate that there was a >60% probability of a disease event each year following pneumonia invasion into bighorn sheep populations. Healthy years also occurred periodically, and understanding the factors driving these apparent fade-out events may be the key to managing this disease. Our data and modelling indicate that pneumonia can have greater impacts on bighorn sheep populations than previously reported, and we present hypotheses about processes involved for testing in future investigations and management.


Assuntos
Surtos de Doenças/veterinária , Pneumonia/veterinária , Doenças dos Ovinos/mortalidade , Carneiro da Montanha , Fatores Etários , Animais , Conservação dos Recursos Naturais , Feminino , Masculino , Noroeste dos Estados Unidos/epidemiologia , Pneumonia/epidemiologia , Pneumonia/microbiologia , Pneumonia/mortalidade , Dinâmica Populacional , Estações do Ano , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/microbiologia
13.
Proc Natl Acad Sci U S A ; 107(43): 18587-92, 2010 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-20937880

RESUMO

Surface Ig (sIg) of follicular lymphoma (FL) is vital for tumor cell survival. We found previously that the Ig in FL is unusual, because the variable region genes carry sequence motifs for N-glycan addition. These are introduced by somatic mutation and are tumor specific. Unexpectedly, added glycans terminate at high mannose, suggesting a potentially important interaction of FL cells with mannose-binding lectins of the innate immune system. We have now identified mannosylated IgM at the surface of primary lymphoma cells. Recombinant lectin domains of the mannose receptor (MR) or DC-SIGN bind mannosylated Igs in vitro and bind to FL cells, signaling sIgM-associated increases in intracellular Ca(2+). Lectins also bind to normal B cells but fail to signal. In contrast, anti-Ig signaled similarly in both FL and normal B cells. Mannosylation patterns were mimicked by FL Ig-derived single-chain Fvs (scFv), providing probes for potential receptors. Mannosylated scFv bound specifically to the lectin domains of the MR and DC-SIGN and blocked signaling. Mannosylated scFv also bound to DC-SIGN on the surface of dendritic cells. This unique lymphoma-specific interaction of sIg with lectins of innate immunity reveals a potential route for microenvironmental support of tumor cells, mediated via the key B-cell receptor.


Assuntos
Lectinas/imunologia , Linfoma Folicular/imunologia , Receptores de Antígenos de Linfócitos B/metabolismo , Linfócitos B/imunologia , Moléculas de Adesão Celular/antagonistas & inibidores , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/imunologia , Técnicas de Silenciamento de Genes , Glicosilação , Humanos , Imunidade Inata , Imunoglobulina M/química , Imunoglobulina M/metabolismo , Técnicas In Vitro , Lectinas Tipo C/antagonistas & inibidores , Lectinas Tipo C/genética , Lectinas Tipo C/imunologia , Linfoma Folicular/etiologia , Linfoma Folicular/genética , Manose/química , Receptor de Manose , Lectina de Ligação a Manose/imunologia , Lectinas de Ligação a Manose/imunologia , Modelos Imunológicos , Receptores de Antígenos de Linfócitos B/química , Receptores de Antígenos de Linfócitos B/genética , Receptores de Superfície Celular/antagonistas & inibidores , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/imunologia , Transdução de Sinais/imunologia , Anticorpos de Cadeia Única/química , Anticorpos de Cadeia Única/metabolismo , Hipermutação Somática de Imunoglobulina
14.
J Med Case Rep ; 17(1): 444, 2023 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-37803426

RESUMO

BACKGROUND: Here we report the only formally documented case in the United Kingdom, to our knowledge, of a cerebral fat embolism secondary to non-iatrogenic trauma through a Tarlov cyst. This case demonstrates the pathology clearly giving an excellent opportunity to demonstrate a rarely seen pathology as well as illustrating the importance of the patient history to guiding further management. CASE PRESENTATION: A middle-aged patient was admitted on the acute medical take complaining of severe headache with photophobia, having just returned after a skiing holiday. Computerised tomography scan of the head showed fat within the anterior horn of both lateral ventricles, and within the subarachnoid space. Re-discussion with the patient and subsequent MRI (Magnetic Resonance Imaging) of the spine identified the pathogenesis of her symptoms: a sacral insufficiency fracture through a Tarlov cyst, causing subarachnoid fat embolism and symptoms of a low-pressure headaches due to a dural leak. Patient was medically managed and discharged with planned follow-up. Due to the Coronavirus pandemic and resolution of the patient's symptoms, they declined further follow up imaging. CONCLUSIONS: The case demonstrates a rarely seen pathology as cause of a common presenting problem, headache. Emphasizing the importance of history taking and appropriate investigations in medical cases that do not conform to the usual diagnosis.


Assuntos
Embolia Gordurosa , Transtornos da Cefaleia , Fraturas da Coluna Vertebral , Cistos de Tarlov , Pessoa de Meia-Idade , Feminino , Humanos , Cistos de Tarlov/complicações , Cistos de Tarlov/diagnóstico , Fraturas da Coluna Vertebral/complicações , Fraturas da Coluna Vertebral/diagnóstico por imagem , Embolia Gordurosa/diagnóstico por imagem , Embolia Gordurosa/etiologia , Cefaleia/etiologia
15.
Aust J Gen Pract ; 52(4): 173-180, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-37021442

RESUMO

BACKGROUND: Deprescribing is an integral part of patient care. The term 'deprescribing' may be new to some, but the concept is not. Deprescribing refers to the planned withdrawal of medicines that are causing harm or not helping an individual. OBJECTIVE: This article collates the latest evidence on deprescribing to guide general practitioners (GPs) and nurse practitioners on how to deprescribe for their elderly patients. DISCUSSION: Deprescribing is a safe and effective method of reducing polypharmacy and high-risk prescribing. The challenge for GPs in deprescribing medicines for older people is to avoid adverse drug withdrawal events. Strategies to deprescribe confidently in partnership with patients include incorporating a 'stop slow, go low' approach and careful consideration of the medicine withdrawal plan.


Assuntos
Desprescrições , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Medicina Geral , Clínicos Gerais , Humanos , Idoso
16.
Arch Gerontol Geriatr ; 105: 104849, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36399891

RESUMO

OBJECTIVE: To describe medicines regimens used by older people living in residential aged care facilities (RACFs). MATERIALS AND METHODS: This cross-sectional study presents baseline data from a randomised controlled trial in seventeen Australian RACFs that recruited residents aged 65 years and older at the participating facilities. The main outcome measures were to evaluation of medicines utilisation, including the number of medicines, medicine regimen complexity, potential under-prescribing and high-risk prescribing (prescribing cascades, anticholinergic or sedative medicines or other potentially inappropriate medicines) with data analysed descriptively. RESULTS: Medicines regimens were analysed for 303 residents (76% female) with a mean age of 85.0 ± 7.5 years, of whom the majority were living with dementia (72%). Residents were prescribed an average of 10.3 ± 4.5 regular medicines daily. Most participants (85%) had highly complex regimens. Most residents (92%) were exposed to polypharmacy (five or more medicines). Nearly all, 302 (98%) residents had at least one marker of potentially suboptimal prescribing. At least one instance of potential under-prescribing was identified in 86% of residents. At least one instance of high-risk prescribing was identified in 81% of residents including 16% of participants with at least one potential prescribing cascade. CONCLUSION(S): Potentially suboptimal prescribing affected almost all residents in this study, and most had highly complex medicines regimens. If generalisable, these findings indicate most older people in RACFs may be at risk of medicines-related harm from suboptimal prescribing, in addition to the burden of administration of complex medicines regimens for facility staff and residents.


Assuntos
Estudos Transversais , Feminino , Humanos , Idoso , Idoso de 80 Anos ou mais , Masculino , Austrália
17.
Arch Gerontol Geriatr ; 107: 104910, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36565605

RESUMO

BACKGROUND: Deprescribing is an intervention to address the high prevalence of inappropriate polypharmacy in older people living in residential aged care facilities (RACFs). Many deprescribing interventions are complex and involve several stages including initial pharmacist recommendation, subsequent acceptance of the recommendations by a prescriber and the patient, and then actual implementation. OBJECTIVES: This study aimed to investigate pharmacist deprescribing recommendations for residents within RACFs, general practitioner (GP) acceptance, and the actual implementation of the accepted recommendations at 12-month. METHODS: The intervention occurred as part of a randomised controlled trial and comprised a pharmacist-led medication review using an evidence-based algorithm, with the focus on identifying medications to potentially deprescribe. Consent to participate was obtained from residents (or surrogate decision-makers), RACF nursing staff and the resident's GP. Deprescribing recommendations were reviewed by GPs before implementation as part of the intervention and control arms of the trial, although control group participants continued to receive their usual medications in a blinded manner. RESULTS: There were 303 participants enrolled in the study, and 77% (941/1222) of deprescribing recommendations suggested by the pharmacists were accepted by GPs. Of the recommendations accepted by GPs, 74% (692/ 941) were successfully implemented at the end of the follow-up visit at 12 months. The most common reason for deprescribing was because medications were no longer needed (42%, 513/ 1231). CONCLUSION: Pharmacist-led deprescribing recommendations arising from an algorithm-based medication review are acceptable to doctors and can have a significant impact on reducing the number of inappropriate medications consumed by older people in RACFs. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12613001204730.


Assuntos
Desprescrições , Clínicos Gerais , Idoso , Humanos , Farmacêuticos , Austrália , Instituição de Longa Permanência para Idosos , Polimedicação
18.
Infect Immun ; 80(1): 369-80, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22025512

RESUMO

Enterohemorrhagic Escherichia coli O157:H7 (EHEC O157) is an important cause of food and waterborne illness in the developed countries. Cattle are a reservoir host of EHEC O157 and a major source of human exposure through contaminated meat products. Shiga toxins (Stxs) are an important pathogenicity trait of EHEC O157. The insertion sites of the Stx-encoding bacteriophages differentiate EHEC O157 isolates into genogroups commonly isolated from cattle but rarely from sick humans (bovine-biased genotypes [BBG]) and those commonly isolated from both cattle and human patients (clinical genotypes [CG]). Since BBG and CG share the cardinal virulence factors of EHEC O157 and are carried by cattle at similar prevalences, the infrequent occurrence of BBG among human disease isolates suggests that they may be less virulent than CG. We compared the virulence potentials of human and bovine isolates of CG and BBG in newborn conventional pig and weaned Dutch Belted rabbit models. CG-challenged piglets experienced severe disease accompanied by early and high mortality compared to BBG-challenged piglets. Similarly, CG-challenged rabbits were likely to develop lesions in kidney and intestine compared with the BBG-challenged rabbits. The CG strains used in this study carried stx2 and produced significantly higher amounts of Stx, whereas the BBG strains carried the stx2c gene variant only. These results suggest that BBG are less virulent than CG and that this difference in virulence potential is associated with the Stx2 subtype(s) carried and/or the amount of Stx produced.


Assuntos
Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Escherichia coli O157/patogenicidade , Animais , Animais Recém-Nascidos , Bovinos , DNA Bacteriano/genética , Modelos Animais de Doenças , Escherichia coli O157/genética , Escherichia coli O157/isolamento & purificação , Genótipo , Humanos , Prófagos/genética , Coelhos , Toxinas Shiga/genética , Análise de Sobrevida , Suínos , Virulência
19.
Blood ; 115(1): 71-7, 2010 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-19887677

RESUMO

The cell of origin of chronic lymphocytic leukemia (CLL) has long been sought, and immunoglobulin gene analysis provides new clues. In the unmutated subset (U-CLL), there is increased usage of the 51p1-related alleles of the immunoglobulin heavy chain variable 1-69 gene, often combined with selected genes and with immunoglobulin heavy chain diversity IGHJ6. Stereotypic characteristics of the HCDR3 result and suggest antigen selection of the leukemic clones. We have now analyzed 51p1/IGHJ6 combinations in normal blood B cells from 3 healthy persons for parallel sequence patterns. A high proportion (33.3% of sequences) revealed stereotypic patterns, with several (15.0%) being similar to those described in U-CLL. Previously unreported CLL-associated stereotypes were detected in 4.8%. Stereotypes (13.6%) not detected in CLL also were found. The HCDR2-IGHJ6 sequences were essentially unmutated. Junctional amino acids in normal B cells were heterogeneous, as in cases of stereotyped CLL. Phenotypically, normal B cells expressing 51p1-derived immunoglobulin M were naive. This snapshot of the naive B-cell repertoire reveals subsets of B cells closely related to those characteristic of CLL. Conserved patterns in the 51p1-encoded immunoglobulin M of normal B cells suggest a restricted sequence repertoire shaped by evolution to recognize common pathogens. Proliferative pressure on these cells is the likely route to U-CLL.


Assuntos
Linfócitos B/imunologia , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/imunologia , Mutação/genética , Idoso , Alelos , Sequência de Aminoácidos , Sequência de Bases , Doadores de Sangue , Regiões Determinantes de Complementaridade/química , Regiões Determinantes de Complementaridade/genética , Regiões Determinantes de Complementaridade/imunologia , Feminino , Rearranjo Gênico de Cadeia Pesada de Linfócito B/imunologia , Humanos , Cadeias Pesadas de Imunoglobulinas/química , Cadeias Pesadas de Imunoglobulinas/imunologia , Região Variável de Imunoglobulina/química , Região Variável de Imunoglobulina/imunologia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Fenótipo
20.
Blood ; 115(21): 4198-205, 2010 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-20237321

RESUMO

Surface IgM (sIgM) has a key influence on the clinical behavior of chronic lymphocytic leukemia (CLL). We now report that it exists in 2 forms with different N-glycosylation patterns in the mu-constant region. One glycoform is similar to normal B cells in bearing mature complex glycans common to most cell-surface glycoproteins. The other is an immature mannosylated form more characteristic of mu chains in the endoplasmic reticulum. Unmutated CLL (U-CLL) expresses a higher proportion of mannosylated surface mu chains than mutated CLL. Normal B cells express only the mature glycoform but can express the immature form after persistent engagement of sIgM, suggesting that glycan modification is a consequence of antigen exposure. CLL cells express variable proportions of the mannosylated form and can revert to the mature form after incubation in vitro. Both glycoforms are able to signal after sIgM engagement in vitro, leading to enhanced tyrosine phosphorylation. These findings support the concept that CLL cells are continuously exposed to antigen in vivo, driving the N-glycosylation pattern of expressed sIgM toward a mannosylated form, especially in U-CLL. Strikingly, this is reminiscent of follicular lymphoma, where mannosylated Ig is expressed constitutively via N-glycosylation sites in the variable region, suggesting a functional asset for this glycoform.


Assuntos
Imunoglobulina M/química , Imunoglobulina M/metabolismo , Leucemia Linfocítica Crônica de Células B/imunologia , Receptores de Antígenos de Linfócitos B/química , Receptores de Antígenos de Linfócitos B/metabolismo , Apresentação de Antígeno , Linfócitos B/imunologia , Estudos de Casos e Controles , Glicosilação , Humanos , Imunoglobulina M/genética , Cadeias mu de Imunoglobulina/química , Cadeias mu de Imunoglobulina/genética , Cadeias mu de Imunoglobulina/metabolismo , Leucemia Linfocítica Crônica de Células B/genética , Modelos Imunológicos , Mutação , Polissacarídeos/química , Polissacarídeos/genética , Prognóstico , Receptores de Antígenos de Linfócitos B/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA