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1.
Ann Oncol ; 28(11): 2761-2767, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-29112701

RESUMO

Background: Combination pertuzumab, trastuzumab, and docetaxel (D) is considered standard first-line treatment of human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. This post hoc, exploratory analysis of CLEOPATRA study data evaluated the clinical effects of D treatment duration within this regimen. The clinical benefits of pertuzumab and trastuzumab by different durations of D treatment were also evaluated. Patients and methods: Patients with HER2-positive metastatic breast cancer received trastuzumab and D plus pertuzumab or placebo. Clinical outcomes were analyzed by the number of D cycles that patients received (<6D, 6D, or >6D). Progression-free survival (PFS) and overall survival (OS) for each treatment arm within each D cycle group were estimated using the Kaplan-Meier approach. Time-dependent, multivariate Cox regression was applied to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for HER2-targeted therapy and D cycle groups. Results: Overall, 804 patients received <6D (n = 119), 6D (n = 210), or >6D (n = 475) cycles. After adjusting for pertuzumab benefits versus placebo (PFS HR = 0.61, 95% CI 0.51-0.74, P < 0.0001; OS HR = 0.60, 95% CI, 0.49-0.74, P < 0.0001), >6D versus 6D cycles was not associated with statistically significant improvements in PFS (HR = 0.80, 95% CI 0.63-1.01, P = 0.0640) or OS (HR = 0.88, 95% CI 0.69-1.12, P = 0.3073). Consistent improvements in PFS and OS were observed with pertuzumab versus placebo, irrespective of D duration. The HRs for PFS were 0.395, 0.615, and 0.633 for <6D, 6D, and >6D cycles, respectively (P < 0.05 for all D cycle groups). Corresponding HRs for OS were 0.577, 0.700, and 0.612, respectively (P < 0.05 for <6D and >6D). Conclusions: After accounting for pertuzumab benefits, more than six cycles of D treatment was not associated with significant improvements in either PFS or OS compared with six cycles. The addition of pertuzumab to trastuzumab improved clinical outcomes versus trastuzumab plus placebo, regardless of D treatment duration. ClinicalTrials.gov identifier: NCT00567190.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Docetaxel/uso terapêutico , Receptor ErbB-2/metabolismo , Trastuzumab/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama Masculina/tratamento farmacológico , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Placebos/administração & dosagem , Adulto Jovem
2.
Anal Chem ; 89(8): 4721-4728, 2017 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-28345869

RESUMO

A process for production of micrometer-sized particles composed of uranium oxide using aerosol spray pyrolysis is characterized with respect to the various production parameters. The aerosol is generated using a vibrating orifice aerosol generator providing monodisperse droplets, which are oxidized in a subsequent heat treatment. The final particles are characterized with microanalytical methods to determine size, shape, internal morphology, and chemical and structural properties in order to assess the suitability of the produced particles as a reference material for microanalytical methods, in particular, for mass spectrometry. It is demonstrated that physicochemical processes during particle formation and the heat treatment to chemically transform particles into an oxide strongly influence the particle shape and the internal morphology. Synchrotron µ-X-ray based techniques combined with µ-Raman spectroscopy have been applied to demonstrate that the obtained microparticles consist of a triuranium octoxide phase. Our studies demonstrate that the process is capable of delivering spherical particles with determined uniform size and elemental as well as chemical composition. The particles therefore represent a suitable base material to fulfill the homogeneity and stability requirements of a reference material for microanalytical methods applied in, for example, international safeguards or nuclear forensics.

3.
Cell Death Differ ; 22(9): 1413-24, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26160070

RESUMO

Huntington's disease (HD) is an inherited, neurodegenerative disorder caused by a single-gene mutation: a CAG expansion in the huntingtin (HTT) gene that results in production of a mutated protein, mutant HTT, with a polyglutamine tail (polyQ-HTT). Although the molecular pathways of polyQ-HTT toxicity are not fully understood, because protein misfolding and aggregation are central features of HD, it has long been suspected that cellular housekeeping processes such as autophagy might be important to disease pathology. Indeed, multiple lines of research have identified abnormal autophagy in HD, characterized generally by increased autophagic induction and inefficient clearance of substrates. To date, the origin of autophagic dysfunction in HD remains unclear and the search for actors involved continues. To that end, recent studies have suggested a bidirectional relationship between autophagy and primary cilia, signaling organelles of most mammalian cells. Interestingly, primary cilia structure is defective in HD, suggesting a potential link between autophagic dysfunction, primary cilia and HD pathogenesis. In addition, because polyQ-HTT also accumulates in primary cilia, the possibility exists that primary cilia might play additional roles in HD: perhaps by disrupting signaling pathways or acting as a reservoir for secretion and propagation of toxic, misfolded polyQ-HTT fragments. Here, we review recent research suggesting potential links between autophagy, primary cilia and HD and speculate on possible pathogenic mechanisms and future directions for the field.


Assuntos
Autofagia/fisiologia , Cílios/patologia , Doença de Huntington/patologia , Animais , Modelos Animais de Doenças , Humanos , Transdução de Sinais
4.
Nanoscale ; 6(15): 8919-25, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24966016

RESUMO

We report on PbS colloidal nanocrystals that combine within one structure solubility in physiological solvents with near-infrared photoluminescence, and magnetic and optical properties tuneable by the controlled incorporation of magnetic impurities (Mn). We use high magnetic fields (B up to 30 T) to measure the magnetization of the nanocrystals in liquid and the strength of the sp-d exchange interaction between the exciton and the Mn-ions. With increasing Mn-content from 0.1% to 7%, the mass magnetic susceptibility increases at a rate of ∼ 10(-7) m(3) kg(-1) per Mn percentage; correspondingly, the exciton g-factor decreases from 0.47 to 0.10. The controlled modification of the paramagnetism, fluorescence and exciton g-factor of the nanocrystals is relevant to the implementation of these paramagnetic semiconductor nanocrystals in quantum technologies ranging from quantum information to magnetic resonance imaging.

5.
Ann Oncol ; 24(10): 2630-2635, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23868905

RESUMO

BACKGROUND: The phase III CLEOPATRA study demonstrated that combining pertuzumab with trastuzumab plus docetaxel significantly improves progression-free and overall survival in previously untreated HER2-positive metastatic breast cancer. Here, we report health-related quality-of-life (HRQoL) results from CLEOPATRA. PATIENTS AND METHODS: Participants were randomly assigned to pertuzumab or placebo, each given with trastuzumab plus docetaxel every 3 weeks. Pertuzumab and trastuzumab were administered until progression and six or more docetaxel cycles were recommended. Time from randomization to a ≥ 5-point decrease in Trial Outcome Index-Physical/Functional/Breast (TOI-PFB) of the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire was analyzed as a prespecified secondary end point. A post hoc exploratory analysis investigated time to ≥ 2-point deterioration in Breast Cancer Subscale (BCS) score. RESULTS: Time to ≥ 5-point decline in TOI-PFB did not differ significantly between the pertuzumab and placebo arms [hazard ratio (HR), 0.97; P = 0.7161]. The median times to TOI-PFB deterioration were 18.4 and 18.3 weeks, respectively (approximately six cycles). The mean TOI-PFB declined slightly until week 18 and recovered thereafter. Pertuzumab increased time until BCS deterioration versus placebo (median 26.7 versus 18.3 weeks; HR, 0.77; P = 0.0061). CONCLUSIONS: Combining pertuzumab with trastuzumab and docetaxel had no adverse impact on HRQoL and may prolong time to worsening of breast cancer-specific symptoms.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Taxoides/uso terapêutico , Anticorpos Monoclonais Humanizados/efeitos adversos , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Biomarcadores Tumorais , Neoplasias da Mama/mortalidade , Intervalo Livre de Doença , Docetaxel , Método Duplo-Cego , Feminino , Humanos , Metástase Neoplásica/tratamento farmacológico , Placebos/administração & dosagem , Qualidade de Vida , Receptor ErbB-2/metabolismo , Inquéritos e Questionários , Sobrevida , Taxoides/efeitos adversos , Trastuzumab , Resultado do Tratamento
6.
Aliment Pharmacol Ther ; 38(3): 303-12, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23750991

RESUMO

BACKGROUND: Guidelines recommend screening for hepatocellular cancer (HCC) with ultrasonography. The performance of ultrasonography varies widely. Computed tomography (CT) is less operator dependent. AIM: To compare the performance and cost of twice-a-year ultrasonography to once-a-year triple-phase-contrast CT for HCC screening in veterans. We hypothesised that CT detects smaller HCCs at lower overall cost. METHOD: One hundred and sixty-three subjects with compensated cirrhosis were randomised to biannual ultrasonography or yearly CT. Twice-a-year alpha-feto protein testing was performed in all patients. Contingency table analysis using chi-squared tests was used to determine differences in sensitivity and specificity of screening arms, survival analysis with Kaplan-Meier method to determine cumulative cancer rates. Multivariate logistic regression models were used to examine predictive factors. RESULTS: Hepatocellular cancer incidence rate was 6.6% per year. Nine HCCs were detected by ultrasonography and eight by CT. Sensitivity and specificity were 71.4% and 97.5%, respectively, for ultrasonography vs. 66.7% and 94.4%, respectively, for CT. Although 58.8% of screen-detected HCC were early stage (Barcelona Clinic Liver Cancer stage A), only 23.5% received potentially curative treatment despite all treatment options being available. HCC-related and overall mortality were 70.5% and 82.3%, respectively, in patients with screen-detected tumour. Overall costs were less for biannual ultrasonography than annual CT. CONCLUSIONS: Biannual ultrasonography was marginally more sensitive and less costly for detection of early HCC compared with annual CT. Despite early detection, HCC-related mortality was high. These data support the use of biannual ultrasonography for HCC surveillance in a US patient population (NCT01350167).


Assuntos
Carcinoma Hepatocelular/diagnóstico , Neoplasias Hepáticas/diagnóstico , Carcinoma Hepatocelular/diagnóstico por imagem , Feminino , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/economia , Tomografia Computadorizada por Raios X/métodos , Ultrassonografia/economia , Ultrassonografia/métodos , Estados Unidos
7.
Methods Mol Biol ; 989: 99-108, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23483390

RESUMO

The common procedures that are used to quantify cyclobutane pyrimidine dimers (CPD) comprise the extraction of cellular DNA followed by the detection of this nucleic acid modification by immunoblotting or electrophoretic methods. Consequently, these approaches provide an averaged damage intensity value of a whole population of cells and are not applicable to studies where a small subgroup such as somatic stem cells are intended to be investigated and the individual cellular damage is of interest. Here, we describe a strategy to isolate epidermal stem cells from minimum human epidermis samples and a subsequent immunocytochemical quantification of cellular CPDs. Besides the determination of the DNA damage status, this technique allows for the examination of cellular CPD intensity distributions.


Assuntos
Células Epidérmicas , Dímeros de Pirimidina/metabolismo , Células-Tronco/citologia , Dano ao DNA/efeitos da radiação , Humanos , Imuno-Histoquímica , Pele/citologia , Células-Tronco/efeitos da radiação , Raios Ultravioleta
8.
J Dermatol Sci ; 67(1): 44-50, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22475419

RESUMO

BACKGROUND: It has been shown for various organisms that expression of tropoelastin (TE) is high during fetal and neonatal growth and that it is reduced in adulthood by an unknown mechanism. OBJECTIVE: To highlight the process of TE mRNA repression in vivo, total RNA from human skin biopsies was analyzed and TE mRNA expression was compared in fetal and adult donors. METHODS: TaqMan Real-Time PCR, Poly(A) tail length assay, immunoblot. RESULTS: In this study a more than 30-fold reduction of mature TE mRNA was detected whereas the decline on pre-mRNA level was not pronounced. This finding supports the hypothesis that the repression of mature TE mRNA is for the most part due to posttranscriptional mechanisms. Since deadenylation-dependent mRNA destabilization is the major decay pathway for most mRNAs, poly(A) tail length of mature TE mRNA was analyzed in fetal and adult human skin, lung and uterus, showing a profound reduction of poly(A) tail length in the adult samples. While TE mRNA is repressed in adult tissues in vivo, TGF-ß(1) has been shown to induce expression of TE mRNA in vitro on the posttranscriptional level. To analyze the underlying mechanism, TE mRNA poly(A) tail length was analyzed in human dermal fibroblasts after treatment with TGF-ß(1)in vitro. Besides the expected increase in TE expression, TGF-ß(1) treatment resulted in a significant stabilization of TE mRNA poly(A) tail length. CONCLUSION: Our findings correlate for the first time TE expression level with poly(A) tail length and suggest that maintenance of poly(A) tail and deadenylation of TE mRNA might be general mechanisms involved in the regulation of TE expression.


Assuntos
RNA Mensageiro/metabolismo , Pele/metabolismo , Tropoelastina/genética , Adulto , Fatores Etários , Biópsia , Western Blotting , Células Cultivadas , Regulação para Baixo , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Idade Gestacional , Humanos , Pulmão/embriologia , Pulmão/metabolismo , Masculino , Pessoa de Meia-Idade , Processamento Pós-Transcricional do RNA , Estabilidade de RNA , Reação em Cadeia da Polimerase em Tempo Real , Pele/embriologia , Fator de Crescimento Transformador beta1/metabolismo , Tropoelastina/metabolismo , Útero/embriologia , Útero/metabolismo
9.
J Surg Case Rep ; 2012(8): 18, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-24960776

RESUMO

Internal iliac artery aneurysms are rare, but with a mortality approaching 50% in those that rupture, prompt diagnosis is essential. Often presentation is nonspecific; a wide variety of symptoms and signs have been encountered, illustrating a challenge in identification. We report a case of ruptured internal iliac artery aneurysm presenting as urinary retention. The importance of maintaining a broad differential in cases of urinary retention is clearly highlighted.

10.
Diabetes Obes Metab ; 12 Suppl 2: 126-33, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21029309

RESUMO

Nitric oxide (NO) serves as a messenger molecule in a variety of physiological systems and also converts into toxic radical species that can damage cells through a process known as nitrosative stress. While the physiological roles of NO in blood vessel dilation, the nervous system and the immune system are well established, recent studies have begun to investigate the role of NO in metabolism and energy expenditure through modulation of mitochondria. NO appears to stimulate mitochondrial biogenesis in certain situations through activation of proteins such as peroxisome proliferator-activated receptor γ (PPARγ) co-activator 1α (PGC1-α). Because of this link between NO and mitochondrial biogenesis, the role of NO in certain aspects of metabolism, including exercise response, obesity, fat cell differentiation and caloric restriction, are the subject of increasing investigation. In addition to its role in mitochondrial biogenesis, NO also stimulates mitochondrial fragmentation, which can be caused by too much mitochondrial fission or inhibition of mitochondrial fusion and can result in bioenergetic failure. While the contribution of NO-mediated mitochondrial fragmentation to neurodegenerative diseases seems clear, the mechanisms by which NO causes fragmentation are uncertain and controversial. In this review, we discuss the role of NO in manipulation of mitochondrial biogenesis and dynamics and how these events contribute to human health- and age-related disease.


Assuntos
Envelhecimento/fisiologia , Mitocôndrias/fisiologia , Doenças Neurodegenerativas/metabolismo , Óxido Nítrico/fisiologia , PPAR gama/fisiologia , Humanos , Doenças Neurodegenerativas/fisiopatologia , Espécies Reativas de Oxigênio
13.
Biotechniques ; 32(4): 796, 798, 800 passim, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11962602

RESUMO

In addition to the originally described Tet transactivator tTA, several variants including transrepressors (tTRs) and reverse transactivators (rtTAs) have been constructed, which we employ here to establish a set of HeLa cell lines carrying different combinations of chromosomally integrated Tet transregulators. We first compare the regulatory properties of these lines using transient transfection of a luciferase reporter gene. Cell lines carrying rtTA-S2 or rtTA-M2 show reduced activity in the absence of dox and higher activation levels in its presence compared to an rtTA line. rtTA-M2 and its synthetic counterpart rtTA2S-M2 show the same regulation pattern. The replacement of the VP16 activation domain in rtTA-S2 or tTA by p65 leads to slightly reduced expression levels. Combination of an rtTA variant with the transrepressor tTR shows active repression of basal expression without affecting the activation level of the transiently transfected reporter gene. However, if the target gene is also chromosomally integrated, then tTR leads to a further reduction of basal expression and also of the maximal expression level. The results demonstrate that different regulatory windows can be achieved using various transregulators or combinations thereof. Thus, the most appropriate combination of regulators can be chosen depending on the application and cell line desired. We suspect that these properties would also allow the construction of transgenic organisms with preselected expression windows.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Tetraciclina/farmacologia , Proteínas Repressoras/genética , Transativadores/genética
14.
Biochem J ; 350 Pt 3: 693-9, 2000 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-10970781

RESUMO

We have studied the effect of an internal load on the movement of actin filaments over a bed of heavy meromyosin (HMM) in the in vitro motility assay. Immobilized alpha-actinin can bind to actin filaments reversibly and ultimately stop the filaments from moving. Above a critical concentration of alpha-actinin, thin filament velocity rapidly diminished to zero. The fraction of thin motile filaments decreased linearly to zero with increasing alpha-actinin concentration. The concentration of alpha-actinin needed to stop all filaments from moving (0.8 microg/ml with actin) was very consistent both within and between experiments. In the present study we have defined the 'index of retardation' as the concentration of alpha-actinin needed to stop all filament movement, and we propose that this index is a measure of the isometric force exerted by HMM on actin filaments. When we measured the effect of immobilized alpha-actinin on motility in the presence of 10 mM P(i) we found that the index of retardation was 0.62+/-0.07 (n=3) times that in the absence of P(i). This observation is in agreement with the reduction of isometric tension in chemically-skinned muscle due to P(i). In a series of comparative experiments we observed that tropomyosin and troponin increase the index of retardation and that the degree of increase depends upon the tropomyosin isoform studied. The index of retardation of actin is increased 1.8-fold by skeletal-muscle tropomyosin, and 3-fold by both cardiac-muscle and smooth-muscle tropomyosin. In the presence of troponin the index of retardation is 2.9-3.4-fold greater than that of actin with all tropomyosin isoforms.


Assuntos
Actinas/fisiologia , Miosinas/fisiologia , Tropomiosina/fisiologia , Troponina/fisiologia , Animais , Contração Muscular , Músculo Esquelético/fisiologia , Coelhos
15.
South Med J ; 93(7): 698-702, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10923959

RESUMO

Intrahepatic nonparasitic cystic disease is rare and may be of congenital or neoplastic origin. The most frequent symptoms and signs are nonspecific and include pain, nausea, fullness, increased girth, and palpable mass. Interventional therapy is reserved for symptomatic patients, which usually corresponds to cysts >5 cm in diameter. Retrospective analysis revealed 26 cases of intrahepatic cystic disease over 15 years at our institution. We discuss the case of a patient who had bilobular biliary cystadenomatous disease, a rare, benign variant of intrahepatic nonparasitic cystic disease.


Assuntos
Adenoma de Ducto Biliar/diagnóstico , Neoplasias dos Ductos Biliares/diagnóstico , Ductos Biliares Intra-Hepáticos/patologia , Cistadenoma/diagnóstico , Dor Abdominal/diagnóstico , Idoso , Doenças dos Ductos Biliares/diagnóstico , Cistos/diagnóstico , Diagnóstico Diferencial , Feminino , Seguimentos , Humanos , Náusea/diagnóstico
16.
J Mol Cell Cardiol ; 32(8): 1489-98, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10900175

RESUMO

The properties of mutant contractile proteins that cause hypertrophic cardiomyopathy (HCM) have been investigated in expression studies and in mouse models. There is growing evidence that the precise isoforms of both the mutated protein and its interacting partners can qualitatively influence the effects of the mutation. We therefore investigated the functional effects of two HCM mutations in alpha -tropomyosin, Asp175Asn and Glu180Gly, in the in vitro motility assay using recombinant human alpha -tropomyosin, expressed with an N-terminal alanine-serine extension (AStm) to mimic acetylation in vivo, and purified native human cardiac troponin. The expected switching off of reconstituted filament movement at pCa9, and switching on at pCa5, was observed with no difference in fraction of filaments motile or filament velocity, between wild-type and mutant filaments. However, we observed increased Ca(2+)sensitivity of fraction of filaments motile using the mutant tropomyosin compared to wild-type (DeltaEC(50)+0.082+/-0. 019 pCa units for Asp175Asn and +0.115+/-0.021 for Glu180Gly). Indirect measurements using immobilized alpha -actinin to retard filament movement showed that filaments reconstituted with mutant AStm produced the same force as wild-type filaments. The results using human cardiac regulatory proteins reveal different effects of the HCM mutations in tropomyosin compared to studies using heterologous systems. By performing parallel experiments using either human cardiac or rabbit skeletal troponin we show that the cardiac-specific phenotype of HCM mutations in alpha -tropomyosin is not the result of more marked functional changes when interacting with cardiac troponin.


Assuntos
Cardiomegalia/genética , Cardiomiopatias/genética , Miocárdio/metabolismo , Tropomiosina/genética , Troponina/metabolismo , Animais , Asparagina/química , Ácido Aspártico/química , Cálcio/metabolismo , Movimento Celular , Relação Dose-Resposta a Droga , Ácido Glutâmico/química , Glicina/química , Coração/fisiologia , Humanos , Microscopia de Fluorescência , Fibras Musculares de Contração Rápida/metabolismo , Músculo Esquelético/metabolismo , Mutagênese , Coelhos , Proteínas Recombinantes/metabolismo , Troponina/genética
17.
Circ Res ; 86(11): 1146-52, 2000 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-10850966

RESUMO

Familial hypertrophic cardiomyopathy (HCM) is caused by mutations in at least 8 contractile protein genes, most commonly beta myosin heavy chain, myosin binding protein C, and cardiac troponin T. Affected individuals are heterozygous for a particular mutation, and most evidence suggests that the mutant protein acts in a dominant-negative fashion. To investigate the functional properties of a truncated troponin T shown to cause HCM, both wild-type and mutant human cardiac troponin T were overexpressed in Escherichia coli, purified, and combined with human cardiac troponins I and C to reconstitute human cardiac troponin. Significant differences were found between the regulatory properties of wild-type and mutant troponin in vitro, as follows. (1) In actin-tropomyosin-activated myosin ATPase assays at pCa 9, wild-type troponin caused 80% inhibition of ATPase, whereas the mutant complex gave negligible inhibition. (2) Similarly, in the in vitro motility assay, mutant troponin failed to decrease both the proportion of actin-tropomyosin filaments motile and the velocity of motile filaments at pCa 9. (3) At pCa 5, the addition of mutant complex caused a greater increase (21.7%) in velocity of actin-tropomyosin filaments than wild-type troponin (12.3%). These data suggest that the truncated troponin T prevents switching off of the thin filament at low Ca(2+). However, the study of thin filaments containing varying ratios of wild-type and mutant troponin T at low Ca(2+) indicated an opposite effect of mutant troponin, causing enhancement of the inhibitory effect of wild-type complex, when it is present in a low ratio (10% to 50%). These multiple effects need to be taken into account to explain the physiological consequences of this mutation in HCM. Further, these findings underscore the importance of studying mixed mutant:wild-type preparations to faithfully model this autosomal-dominant disease.


Assuntos
Cardiomiopatia Hipertrófica/genética , Miocárdio/metabolismo , Troponina T/genética , Troponina T/fisiologia , Actinas/fisiologia , Cálcio/metabolismo , Cálcio/fisiologia , Ativação Enzimática/fisiologia , Escherichia coli/metabolismo , Humanos , Mutação/fisiologia , Subfragmentos de Miosina/metabolismo , Miosinas/antagonistas & inibidores , Miosinas/metabolismo , Fragmentos de Peptídeos/genética , Proteínas Recombinantes/metabolismo , Tropomiosina/fisiologia , Troponina/genética , Troponina/fisiologia , Troponina T/química
18.
Health Serv Manage Res ; 13(2): 127-32, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-11184010

RESUMO

Visits to physicians (MDs), physician assistants (PAs) or nurse practitioners (NPs) by residents of a rural county in the upper-middle west of the United States were analysed in this study. A telephone survey yielded 250 responses. The dependent variable was the natural logarithm of the number of times the respondent had seen a health professional (MD, PA or NP) in the past two years. Predisposing, enabling and medical need variables were tested as potential predictors of visits. Self-rated health status, being unable to perform usual activities, and feeling upset or 'down in the dumps' proved to be important predictors, as was having a usual source of care. Health insurance coverage and family income was not, however. Unexpectedly, smokers also reported more visits. The implications for policy and future research are discussed.


Assuntos
Nível de Saúde , Visita a Consultório Médico/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Serviços de Saúde Rural/estatística & dados numéricos , Adulto , Coleta de Dados , Feminino , Pesquisa sobre Serviços de Saúde , Humanos , Iowa/epidemiologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Autoavaliação (Psicologia)
20.
J Appl Microbiol ; 82(2): 267-72, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12452604

RESUMO

Variable germination and outgrowth occurred when Bacillus subtilis NCTC 8236 spores were inoculated into nutrient broth prepared with distilled water. More reproducible findings were achieved when the medium was prepared with Elgastat water and the greatest reproducibility occurred with Elgastat water as vehicle combined with a rigorous acid-washing of all glassware. This combined procedure also produced optimum and reproducible results for the synchronous growth of two B. subtilis 168 strains in casein medium supplemented with appropriate amino acids, a technique of value in monitoring the development of resistance to antibacterial agents during sporulation. The levels of aluminium in distilled water were higher than those of other elements; however, the incorporation of aluminium sulphate into broth prepared with Elgastat water had no effect on germination, and outgrowth was reduced (but not eliminated) only at high concentrations of this salt.


Assuntos
Bacillus subtilis/fisiologia , Esporos Bacterianos/crescimento & desenvolvimento , Água/química , Aminoácidos/metabolismo , Bacillus subtilis/efeitos dos fármacos , Caseínas/metabolismo , Meios de Cultura/química , Meios de Cultura/farmacologia , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/fisiologia
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