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1.
J Ultrasound Med ; 38(2): 371-377, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30043460

RESUMO

OBJECTIVES: Ultrasound (US) is increasingly used in settings where commercial US gel is unavailable. This study evaluated noncommercial gel recipes compared to commercial gel. METHODS: A search for US gel formulations revealed 6 recipes. Half-strength commercial gel and a modified glucomannan recipe were also tested. Nine gels, including commercial gel, were tested in Liberia and the United States. In each session, 2 physician sonologists evaluated 9 gels on 2 models, obtaining videos from the hepatorenal space with a curvilinear transducer, the cardiac parasternal long view with a phased array transducer, and the left basilic vein with a linear transducer. The sonologists and models, who were blinded to gel identity, made independent quantitative and qualitative gel evaluations comparing the test gel to commercial gel. Two physician sonologists who were blinded to the gel identities and a US operator reviewed the images and rated their quality. An analysis of variance in repeated measures was performed to test for differences in the overall score, real-time quality, and other characteristics. Post hoc pairwise comparisons to commercial gel were performed with a Tukey-Kramer adjustment. Inter- and intra-rater reliability was calculated for the image review. RESULTS: Commercial gel earned a perfect score. Compared to commercial gel, xanthine gum gel scored highest, followed by half-strength commercial gel. Hot concentrated glucomannan and cold glucomannan gel were found to be significantly worse than commercial gel. No significant difference was found between images based on the gel used on the image review. CONCLUSIONS: No significant difference in image quality was found between commercial and noncommercial gels on US image review.


Assuntos
Géis/química , Géis/normas , Ultrassonografia/instrumentação , Braço/irrigação sanguínea , Braço/diagnóstico por imagem , Países em Desenvolvimento , Recursos em Saúde , Coração/diagnóstico por imagem , Humanos , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Libéria , Fígado/irrigação sanguínea , Fígado/diagnóstico por imagem , Reprodutibilidade dos Testes , Transdutores , Ultrassonografia/métodos , Estados Unidos
2.
Haemophilia ; 23(5): 784-792, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28662545

RESUMO

BACKGROUND: RUNX1 haplodeficiency is associated with thrombocytopenia, platelet dysfunction and a predisposition to acute leukaemia. Platelets possess three distinct types of granules and secretory processes involving dense granules (DG), α-granules and vesicles or lysosomes containing acid hydrolases (AH). Dense granules and granule deficiencies have been reported in patients with RUNX1 mutations. Little is known regarding the secretion from AH-containing vesicles. METHODS AND RESULTS: We studied two related patients with a RUNX1 mutation, easy bruising, and mild thrombocytopenia. Platelet aggregation and 14 C serotonin in platelet-rich plasma (PRP) were impaired in response to ADP, epinephrine, collagen and arachidonic acid. Contents of DG (ATP, ADP), α-granules (ß-thromboglobulin) and AH-containing vesicles (ß-glucuronidase, ß-hexosaminidase, α-mannosidase) were normal or minimally decreased. Dense granules secretion on stimulation of gel-filtered platelets with thrombin and divalent ionophore A23187 (4-12 µmol L-1 ) were diminished. ß-thromboglobulin and AH secretion was impaired in response to thrombin or A23187. We studied thromboxane-related pathways. The incorporation of 14 C -arachidonic acid into phospholipids and subsequent arachidonic acid release on thrombin activation was normal. Platelet thromboxane A2 production in whole blood serum and on thrombin stimulation of PRP was normal, suggesting that the defective secretion was not due to impaired thromboxane production. CONCLUSIONS: These studies provide the first evidence in patients with a RUNX1 mutation for a defect in AH (lysosomal) secretion, and for a global defect in secretion involving all three types of platelet granules that is unrelated to a granule content deficiency. They highlight the pleiotropic effects and multiple platelet defects associated with RUNX1 mutations.


Assuntos
Transtornos Plaquetários/genética , Transtornos Plaquetários/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Haploinsuficiência , Hidrolases/metabolismo , Adulto , Ácido Araquidônico/metabolismo , Transtornos Plaquetários/sangue , Plaquetas/metabolismo , Estudos de Casos e Controles , Pré-Escolar , Feminino , Humanos , Masculino , Mutação , Fosfolipídeos/biossíntese , Contagem de Plaquetas , Vesículas Secretórias/metabolismo , Serotonina/metabolismo , Tromboxanos/biossíntese
3.
J Thromb Haemost ; 15(4): 792-801, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28075530

RESUMO

Essentials Platelet dense granule (DG) deficiency is a major abnormality in RUNX1 haplodeficiency patients. The molecular mechanisms leading to the platelet DG deficiency are unknown. Platelet expression of PLDN (BLOC1S6, pallidin), involved in DG biogenesis, is regulated by RUNX1. Downregulation of PLDN is a mechanism for DG deficiency in RUNX1 haplodeficiency. SUMMARY: Background Inherited RUNX1 haplodeficiency is associated with thrombocytopenia and platelet dysfunction. Dense granule (DG) deficiency has been reported in patients with RUNX1 haplodeficiency, but the molecular mechanisms are unknown. Platelet mRNA expression profiling in a patient previously reported by us with a RUNX1 mutation and platelet dysfunction showed decreased expression of PLDN (BLOC1S6), which encodes pallidin, a subunit of biogenesis of lysosome-related organelles complex-1 (BLOC-1) involved in DG biogenesis. PLDN mutations in the pallid mouse and Hermansky-Pudlak syndrome-9 are associated with platelet DG deficiency. Objectives We postulated that PLDN is a RUNX1 target, and that its decreased expression leads to platelet DG deficiency in RUNX1 haplodeficiency. Results Platelet pallidin and DG levels were decreased in our patient. This was also observed in two siblings from a different family with a RUNX1 mutation. Chromatin immunoprecipitation and electrophoretic mobility shift assays with phorbol ester-treated human erythroleukemia (HEL) cells showed RUNX1 binding to RUNX1 consensus sites in the PLDN1 5' upstream region. In luciferase reporter studies, mutation of RUNX1 sites in the PLDN promoter reduced activity. RUNX1 overexpression enhanced and RUNX1 downregulation decreased PLDN1 promoter activity and protein expression. RUNX1 downregulation resulted in impaired handling of mepacrine and mislocalization of the DG marker CD63 in HEL cells, indicating impaired DG formation, recapitulating findings on PLDN downregulation. Conclusions These studies provide the first evidence that PLDN is a direct target of RUNX1 and that its dysregulation is a mechanism for platelet DG deficiency associated with RUNX1 haplodeficiency.


Assuntos
Plaquetas/citologia , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Proteínas do Citoesqueleto/metabolismo , Haploinsuficiência , Fosfoproteínas/metabolismo , Vesículas Secretórias/metabolismo , Animais , Sítios de Ligação , Transtornos Plaquetários/genética , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Criança , Pré-Escolar , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Regulação para Baixo , Feminino , Regulação da Expressão Gênica , Síndrome de Hermanski-Pudlak/genética , Humanos , Lectinas/metabolismo , Masculino , Camundongos , Mutação , Proteínas do Tecido Nervoso/metabolismo , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Tetraspanina 30/metabolismo , Trombocitopenia/genética
4.
Trop Med Int Health ; 21(12): 1531-1538, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27758005

RESUMO

OBJECTIVE: We delivered a point-of-care ultrasound training programme in a resource-limited setting in Rwanda, and sought to determine participants' knowledge and skill retention. We also measured trainees' assessment of the usefulness of ultrasound in clinical practice. METHODS: This was a prospective cohort study of 17 Rwandan physicians participating in a point-of-care ultrasound training programme. The follow-up period was 1 year. Participants completed a 10-day ultrasound course, with follow-up training delivered over the subsequent 12 months. Trainee knowledge acquisition and skill retention were assessed via observed structured clinical examinations (OSCEs) administered at six points during the study, and an image-based assessment completed at three points. RESULTS: Trainees reported minimal structured ultrasound education and little confidence using point-of-care ultrasound before the training. Mean scores on the image-based assessment increased from 36.9% (95% CI 32-41.8%) before the initial 10-day training to 74.3% afterwards (95% CI 69.4-79.2; P < 0.001). The mean score on the initial OSCE after the introductory course was 81.7% (95% CI 78-85.4%). The mean OSCE performance at each subsequent evaluation was at least 75%, and the mean OSCE score at the 58-week follow up was 84.9% (95% CI 80.9-88.9%). CONCLUSIONS: Physicians providing acute care in a resource-limited setting demonstrated sustained improvement in their ultrasound knowledge and skill 1 year after completing a clinical ultrasound training programme. They also reported improvements in their ability to provide patient care and in job satisfaction.


Assuntos
Competência Clínica , Educação , Exame Físico , Médicos , Sistemas Automatizados de Assistência Junto ao Leito , Ultrassonografia , Atitude do Pessoal de Saúde , Avaliação Educacional , Humanos , Satisfação no Emprego , Estudos Prospectivos , Ruanda
5.
Acta Crystallogr C ; 69(Pt 12): 1516-23, 2013 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-24311503

RESUMO

Two tosylate salts of an anticancer drug lapatinib, viz. a monotosylate [systematic name: ({5-[4-({3-chloro-4-[(3-fluorophenyl)methoxy]phenyl}amino)quinazolin-6-yl]furan-2-yl}methyl)[2-(methylsulfonyl)ethyl]azanium 4-methylbenzenesulfonate], C29H27ClFN4O4S(+)·C7H7O3S(-), (I), and a ditosylate [systematic name: 4-({3-chloro-4-[(3-fluorophenyl)methoxy]phenyl}amino)-6-]5-({[2-(methylsulfonyl)ethyl]azaniumyl}methyl)furan-2-yl[quinazolin-1-ium bis(4-methylbenzenesulfonate)], C29H28ClFN4O4S(2+)·2C7H7O3S(-), (II), were obtained during crystallization attempts for polymorphism. In both structures, the lapatinib cation is in a distorted U-like conformation and the tosylate anion is clamped between the aniline N atom and methylamine N atom through N-H···O hydrogen bonds, forming an R2(2)(15) ring motif. The 4-anilinoquinazoline ring system is essentially planar in (I), while it is twisted in (II), controlled by an intramolecular C-H···N interaction. In (I), alternating cations and anions are linked by N-H···O hydrogen bonds into C2(2)(6) chains. These chains are linked by cations in a helical manner. The presence of the additional tosylate anion in (II) results in the formation of one-dimensional tapes of fused hydrogen-bonded rings through N-H···O and C-H···O interactions. These studies augment our understanding of the role of nonbonded interactions in the solid state, which is useful for correlation to the physicochemical properties of drug products.


Assuntos
Antineoplásicos/química , Quinazolinas/química , Sais/química , Compostos de Tosil/química , Antineoplásicos/farmacologia , Cristalografia por Raios X , Ligação de Hidrogênio , Lapatinib , Quinazolinas/farmacologia , Sais/farmacologia , Compostos de Tosil/farmacologia
6.
Pak J Biol Sci ; 16(5): 219-25, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24175431

RESUMO

In this study of the recovery and purification of rapamycin from the culture broth of an actinomycetes strain MTCC 5681, we investigated various factors such as biomass separation, suitable solvents for extraction, normal phase and flash chromatographic conditions and selective precipitation to obtain rapamycin in substantially pure form of the product. Adsorption chromatography particularly with normal phase and flash chromatography, in combination with centrifugal decantation is found to be the most suitable for separation as well as purification of rapamycin. Centrifugal decantation technique is likely to emerge as an efficient, industrially scalable, high yielding and economical process for biomass separation. The purity of rapamycin obtained through the method described was 99.4% which has not been reported so far.


Assuntos
Actinobacteria/metabolismo , Cromatografia/métodos , Sirolimo/isolamento & purificação , Actinobacteria/química , Actinobacteria/crescimento & desenvolvimento , Biomassa , Meios de Cultura/química , Meios de Cultura/metabolismo , Fermentação , Sirolimo/química , Sirolimo/metabolismo
7.
Prep Biochem Biotechnol ; 43(6): 539-50, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23742086

RESUMO

The purpose of this investigation is to enhance the production of the immunosuppressant drug rapamycin by subjecting the strain CBS 773.23 to ultraviolet (UV) and N-methyl-N'-nitro-N-nitroso guanidine (NTG) mutations. Among all the mutants tested, MTCC 5681 (NRC-CM03/SH) obtained by NTG mutagenesis of strain CBS 773.72 showed the highest activity, 210 mg/L. The effect of different factors including medium composition, pH, temperature, and intensity of mixing on rapamycin production was studied. Based on the study, the optimal concentrations of soluble starch and dry yeast granules were found to be 50 g/L and 1.5 g/L, respectively. Furthermore, optimal values for pH, temperature, and shaking speed were found to be 6.0, 28°C, and 220 rpm, respectively. The production of rapamycin increased 1.6-fold, to 360 mg/L, in shake-flask culture using the optimal combination of factors observed compared with basal cultivation medium using MTCC 5681 mutant strain.


Assuntos
Fermentação , Microbiologia Industrial/métodos , Sirolimo/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Concentração de Íons de Hidrogênio , Mutagênese , Mutagênicos/farmacologia , Mutação , Nitrogênio/metabolismo , Nitrosoguanidinas/farmacologia , Amido/metabolismo , Streptomyces/efeitos dos fármacos , Streptomyces/crescimento & desenvolvimento , Streptomyces/efeitos da radiação , Temperatura , Raios Ultravioleta , Leveduras
8.
J Thromb Haemost ; 2013 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-23574625

RESUMO

Light transmission aggregometry (LTA) is the most common method used to assess platelet function. However, there is no universal standard for its performance. The Platelet Physiology Subcommittee of the Scientific and Standardization Committee (SSC) of the International Society on Thrombosis and Haemostasis formed a working party of experts with the aim of producing a series of consensus recommendations for standardizing LTA. Due to a lack of investigations that directly compared different methodologies to perform LTA studies, there were insufficient data to develop evidence-based guidelines. Therefore, the RAND method was used, which obtains a formal consensus among experts about the appropriateness of health care interventions, particularly when scientific evidence is absent, scarce and/or heterogeneous. Using this approach, each expert scored as "appropriate", "uncertain" or "inappropriate" a series of statements about the practice of LTA, which included pre-analytical variables, blood collection, blood processing, methodological details, choice of agonists and the evaluation and reporting of results. After presentation and public discussion at SSC meetings, the assessments were further refined to produce final consensus recommendations. Before delivering the recommendations, a formal literature review was performed using a series of defined search terms about LTA. Of the 1830 potentially relevant studies identified, only 14 publications were considered to be actually relevant for review. Based upon the additional information, 6 consensus statements were slightly modified. The final statements were presented and discussed at the SSC Meeting in Cairo (2010) and formed the basis of a consensus document, which is the subject of the present report. This article is protected by copyright. All rights reserved.

9.
Int J Oncol ; 42(1): 168-78, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23151973

RESUMO

Imatinib mesylate is the first tyrosine kinase inhibitor developed and approved for the treatment of chronic myeloid leukemia (CML). In the past few years development of resistance towards imatinib mesylate has been reported. To overcome this problem a series of phenyl amino pyrimidine derivatives have been designed, prepared and evaluated for anti-proliferative activity against the BCR­ABL­positive leukemia cell line K562. Among these phenyl amino pyrimidine derivatives, NRC­AN­019 has been found to be a promising new lead compound for the therapy of imatinib mesylate-resistant chronic myeloid leukemia. In this communication, we describe the design, preparation and preclinical studies of NRC­AN­019.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Benzamidas/síntese química , Benzamidas/farmacologia , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Pirimidinas/síntese química , Pirimidinas/farmacologia , Animais , Linhagem Celular Tumoral , Humanos , Mesilato de Imatinib , Injeções Intraperitoneais , Camundongos , Camundongos Nus , Estrutura Molecular , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Taxa de Sobrevida
10.
Indian J Lepr ; 83(2): 81-6, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21972660

RESUMO

Bargarh district in the western Orissa had high leprosy burden and LEPRA India supported in control activities. Its main focus was on POD care with community participation. After motivation and capacity building, it transferred the responsibility of POD care to affected persons, family, community partners and GHS staff in 2006. The effectiveness of this approach was evaluated in 2009. With personal contact responses from 112 (17%) persons with disability and 18 stakeholders were obtained. Result shows 98% affected persons are staying with family; 92% are practicing self-care; 92% felt self-care is beneficial; 57% and 36% are using commercial and MCR footwear respectively. Surgical correction of deformity is maintained in 80% of cases. Difficulty in activity and in community participation was experienced in about one third of affected persons the latter is mostly due to self stigma. The facilitators were happy with their beneficiaries.


Assuntos
Pessoas com Deficiência/reabilitação , Hanseníase/reabilitação , Autocuidado , Adolescente , Adulto , Idoso , Criança , Participação da Comunidade , Feminino , Humanos , Índia , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Apoio Social , Fatores Socioeconômicos , Inquéritos e Questionários , Adulto Jovem
11.
Indian J Lepr ; 83(1): 31-5, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21638981

RESUMO

This paper indicates the responses of thickened nerve trunks in leprosy patients to MDT. Out of 1625 cases, 557 (34.2%) cases had thickened nerve trunks at the time of registration. From these cases, 175 (31.4%) were randomly selected and re-examined by personal visit about 5 years after RFT. Follow-up showed persistent thickening in 96 (54.8%) cases. Persistence of nerve thickening was higher in MB leprosy. Additional nerve thickening appeared in 8 (4.6%) cases. New disability developed in 6 (3.4%) cases after RFT but these persons did not come for check up voluntarily. Reaction occurred in 6 during follow-up. Both MB and PB considered together thickening continued in as high as 96 (54.8%) compared to persisting skin lesions in 24 (13.7%) cases. Persons with thickened nerve trunks require more counseling to report for check up at the earliest sign of nerve function deficit.


Assuntos
Hansenostáticos/uso terapêutico , Hanseníase/tratamento farmacológico , Nervos Periféricos/patologia , Pele/patologia , Adolescente , Adulto , Idoso , Quimioterapia Combinada , Feminino , Humanos , Hanseníase/patologia , Masculino , Pessoa de Meia-Idade
12.
Int J Oncol ; 39(3): 641-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21674127

RESUMO

Breast cancer is the second most frequently diagnosed tumor in women. Overexpression of human epidermal growth factor receptors (EGFRs) represents a biological subclass of breast cancer with distinct molecular alterations, clinical behavior and response to systemic therapy. In this study, we describe a novel compound (NRC-AN-019), which has better antitumor activity than Lapatinib. Here, we demonstrate that NRC-AN-019 is more effective in inhibiting angiogenic potential and proliferation of both MDAMB231 and HTB20/BT474 cells. FACS analysis shows that NRC-AN-019 treatment caused the accumulation of MDAMB231 and BT474 cells in the sub G0/1 phase in a dose-dependent manner and was accompanied by increased PARP cleavage, which is indicative of apoptosis. In addition, we observed inhibition of EGFR phosphorylation in both MDAMB231 and BT474 cells. From our animal studies using SCID mice implanted with BT474 cells, we observed dose-dependent inhibition of tumor growth in NRC-AN-019-treated animals compared to controls or Lapatinib-treated mice at comparable concentrations. The dose-dependent inhibition of EGFR phosphorylation was confirmed by immunohistochemical analysis of tumor sections. In vitro results demonstrate that NRC-AN-019 is superior to Lapatinib in EGFR-overexpressing cells and has strong anti-angiogenic, anti-proliferative and pro-apoptotic properties in an EGFR-overexpressing background (BT474). In vivo studies demonstrate that the antitumor activity of NRC-AN-019 is better over Lapatinib. These results suggest that NRC-AN-019 has greater therapeutic potential in the treatment of Her-2-positive breast cancer.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Feminino , Humanos , Lapatinib , Masculino , Camundongos , Camundongos Nus , Camundongos SCID , Fosforilação/efeitos dos fármacos , Quinazolinas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Acta Crystallogr C ; 67(Pt 1): o29-32, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21206080

RESUMO

Sorafenib, a drug that targets malignant cancer cells and cuts off the blood supply feeding the tumour, has been crystallized as the free base, 4-(4-{3-[4-chloro-3-(trifluoromethyl)phenyl]ureido}phenoxy)-N-methylpyridine-2-carboxamide, C(21)H(16)ClF(3)N(4)O(3), (I), and as a tosylate salt, 4-(4-{3-[4-chloro-3-(trifluoromethyl)phenyl]ureido}phenoxy)-2-(N-methylcarbamoyl)pyridinium 4-methylbenzenesulfonate, C(21)H(17)ClF(3)N(4)O(3)(+)·C(7)H(7)O(3)S(-), (II). In both structures, the sorafenib molecule is in an extended conformation. The pyridine-2-carboxamide group exhibits a syn conformation of the N atoms in (I), whereas an almost anti orientation is present in (II). In both crystal structures, the two terminal groups, viz. pyridine-2-carboxamide and the trifluorophenyl ring, are oriented differently to the conformations found in enzyme-bound sorafenib. The sorafenib molecules in (I) are linked into zigzag chains by N-H···O hydrogen bonds, whereas in (II) the presence of the additional tosylate anion results in the formation of chains of fused hydrogen-bonded rings. This study reveals the variations in the solid-state conformation of the sorafenib molecule in different crystalline environments.


Assuntos
Antineoplásicos/química , Antineoplásicos/uso terapêutico , Benzenossulfonatos/química , Benzenossulfonatos/farmacologia , Benzenossulfonatos/uso terapêutico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/uso terapêutico , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/uso terapêutico , Piridinas/química , Piridinas/farmacologia , Piridinas/uso terapêutico , Compostos de Tosil/química , Compostos de Tosil/farmacologia , Cristalografia por Raios X , Humanos , Ligação de Hidrogênio , Conformação Molecular , Estrutura Molecular , Niacinamida/análogos & derivados , Compostos de Fenilureia , Sorafenibe
14.
J Thromb Haemost ; 9(2): 383-91, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21129147

RESUMO

BACKGROUND: Platelet factor 4 (PF4) is an abundant protein stored in platelet α-granules. Several patients have been described with platelet PF4 deficiency, including the gray platelet syndrome, characterized by a deficiency of α-granule proteins. Defective granule formation and protein targeting are considered to be the predominant mechanisms. We have reported on a patient with thrombocytopenia and impaired platelet aggregation, secretion, and protein phosphorylation, associated with a mutation in the transcription factor RUNX1. Platelet expression profiling showed decreased transcript expression of PF4 and its non-allelic variant PF4V1. OBJECTIVES: To understand the mechanism leading to PF4 deficiency associated with RUNX1 haplodeficiency, we addressed the hypothesis that PF4 is a transcriptional target of RUNX1. METHODS/RESULTS: Chromatin immunoprecipitation and gel-shift assays with phorbol 12-myristate 13-acetate-treated human erythroleukemia (HEL) cells revealed RUNX1 binding to RUNX1 consensus sites at -1774/-1769 and -157/-152 on the PF4 promoter. In luciferase reporter studies in HEL cells, mutation of each site markedly reduced activity. PF4 promoter activity and PF4 protein level were decreased by small interfering RNA RUNX1 knockdown and increased by RUNX1 overexpression. CONCLUSIONS: Our results provide the first evidence that PF4 is regulated by RUNX1 and that impaired transcriptional regulation leads to the PF4 deficiency associated with RUNX1 haplodeficiency. Because our patient had decreased platelet albumin and IgG (not synthesized by megakaryocytes) levels, we postulate additional defects in RUNX1-regulated genes involved in vesicular trafficking. These studies advance our understanding of the mechanisms in α-granule deficiency.


Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core/genética , Regulação da Expressão Gênica/fisiologia , Fator Plaquetário 4/deficiência , Transcrição Gênica/fisiologia , Adulto , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Ensaio de Desvio de Mobilidade Eletroforética , Técnicas de Silenciamento de Genes , Haplótipos , Humanos , Masculino , RNA Interferente Pequeno
15.
J Hosp Infect ; 69(2): 177-80, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18485531

RESUMO

Antimicrobial resistance is a major problem in present-day therapy. Despite the advent of newer antimicrobial agents with a broad spectrum of activity, multiple antibiotic resistant pathogens are difficult to eliminate from infected sites. The present study was carried out to develop an approach, using citric acid as a sole antimicrobial agent, for the treatment of chronic wound infections caused by multiresistant Escherichia coli (MAREC). A total of 34 cases of chronic wound infections yielding MAREC isolates on culture were studied. The antibacterial effect of citric acid against MAREC was evaluated in vitro by broth dilution method. Three percent citric acid gel was applied to each wound once daily until it healed completely. All 34 isolates were inhibited by citric acid with minimum inhibitory concentrations in the range of 1500-2000 microg/ml. Topical application of 3% citric acid to wounds 7-42 times resulted in elimination of MAREC from infected sites and successful healing of wounds in all 34 patients. This treatment modality was simple, reliable, non-toxic and effective. Hence, the use of citric acid for the cost-effective treatment of wound infections caused by MAREC is recommended.


Assuntos
Antibacterianos/uso terapêutico , Ácido Cítrico/uso terapêutico , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Escherichia coli/efeitos dos fármacos , Infecção dos Ferimentos/tratamento farmacológico , Ácido Cítrico/farmacologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli/isolamento & purificação , Géis/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Resultado do Tratamento
16.
J Thromb Haemost ; 5(1): 146-54, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17059412

RESUMO

We have reported on a patient with thrombocytopenia, impaired platelet aggregation, secretion, phosphorylation of pleckstrin and myosin light chain (MLC), and GPIIb-IIIa activation, associated with a heterozygous mutation in transcription factor CBFA2 (core binding factor A2, RUNX1 or AML1). To obtain insights into the abnormal platelet mechanisms and CBFA2-regulated genes, we performed platelet expression profiling in four control subjects and the patient using the Affymetrix U133 GeneChips. In the patient, 298 probe sets were significantly downregulated at least 2-fold. MLC regulatory polypeptide (MYL9 gene) was decreased approximately 77-fold; this is an important finding because agonist-stimulated MLC phosphorylation is decreased in patient platelets. Genes downregulated > or = 5-fold include those involving calcium binding proteins (CABP5), ion transport (sodium/potassium/Ca exchanger, SLC24A3), cytoskeletal/microtubule proteins (erythrocyte membrane protein band 4.1-like 3, EPB41L3; tropomyosin 1, TPM1; tubulin, alpha 1, TUBA1), signaling proteins (RAB GTPase activating protein 1-like, RABGAP1L; beta3-endonexin, ITGB3 BP) and chemokines (platelet factor 4 variant 1, PF4V1; chemokine CXCL5, CXCL5). These and other downregulated genes are relevant to the patient's platelet defects in function and production. These studies provide the first proof of concept that platelet expression profiling can be applied to obtain insights into the molecular basis of inherited platelet defects.


Assuntos
Plaquetas/metabolismo , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Perfilação da Expressão Gênica , Mutação , Cadeias Leves de Miosina/metabolismo , Ativação Plaquetária , Trombocitopenia/metabolismo , Adulto , Análise por Conglomerados , Regulação para Baixo , Humanos , Immunoblotting , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Trombocitopenia/genética , Trombocitopenia/fisiopatologia
17.
J Thromb Haemost ; 4(12): 2678-86, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16995904

RESUMO

BACKGROUND: Galphaq (Gene GNAQ) plays a major role in platelet signal transduction but little is known regarding its transcriptional regulation. OBJECTIVES: We studied Galphaq promoter activity using luciferase reporter gene assays in human erythroleukemia (HEL) cells treated with phorbol 12-myristate 13-acetate (PMA) for 24 h to induce megakaryocytic transformation. METHODS AND RESULTS: PMA-treated HEL cells showed enhanced Galphaq expression. Reporter (luciferase) gene studies on 5' upstream construct (up to -116 bp from ATG) revealed a negative regulatory site at -238/-202 and two positive sites at -203/-138 and -1116/-731. The positive regulatory region -203/-138 contained overlapping Sp1/AP-2/EGR-1 consensus sites. Gel shift studies on Galphaq oligonucleotides 1 (-203/-175) and 2 (-174/-152) using HEL cell extracts demonstrated protein binding that was due to early growth response factor EGR-1 at two sites. Mutations in either EGR-1 site markedly decreased the gene activity, indicating functional relevance. Mutation of consensus E-Box motif (-185/-180) had no effect. Reduction in the expression of endogenous EGR-1 with antisense oligonucleotide to EGR-1 inhibited PMA-induced Galphaq transcription. Correspondingly, Egr-1 deficient mouse platelets also showed approximately 50% reduction in the Galphaq expression relative to wild-type platelets. CONCLUSIONS: These studies suggest that Galphaq gene is regulated during PMA-induced megakaryocytic differentiation by EGR-1, an early growth response transcription factor that regulates a wide array of genes and plays a major role in diverse activities, including cell proliferation, differentiation and apoptosis, and in vascular response to injury and atherosclerosis.


Assuntos
Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/metabolismo , Megacariócitos/metabolismo , Transcrição Gênica , Animais , Sequência de Bases , Sítios de Ligação , Plaquetas/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proteína 1 de Resposta de Crescimento Precoce/genética , Ensaio de Desvio de Mobilidade Eletroforética , Subunidades alfa Gq-G11 de Proteínas de Ligação ao GTP/genética , Deleção de Genes , Genes Reporter , Humanos , Luciferases , Substâncias Luminescentes , Megacariócitos/citologia , Megacariócitos/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Dados de Sequência Molecular , Oligonucleotídeos/genética , Oligonucleotídeos/metabolismo , Regiões Promotoras Genéticas/genética , RNA Mensageiro/metabolismo , Acetato de Tetradecanoilforbol/análogos & derivados , Acetato de Tetradecanoilforbol/farmacologia , Transfecção
18.
Haemophilia ; 12 Suppl 3: 128-36, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16684008

RESUMO

The bleeding problems associated with common and rare inherited platelet disorders illustrate the importance of platelets to normal haemostasis. At sites of injury, platelets normally adhere, undergo activation, secretion and aggregate formation, and they provide the membrane surface for the assembly of coagulation to generate thrombin. The causes of inherited disorders that alter platelet haemostatic functions are quite diverse, ranging from defects in receptors critical to platelet adhesion and aggregation, to defects in signalling molecules or in transcription factors important for production of functional platelets. The mechanisms of impaired platelet function are largely unknown for the more common disorders that alter platelet activation, secretion and the secondary wave of platelet aggregation. The diagnostic evaluation of congenital platelet disorders has been challenging as some 'platelet-type' bleeding symptoms, such as bruising, are quite common in the general population. Moreover, the diagnostic tests used by clinical laboratories to evaluate disorders of platelet function have not been standardized. In individuals recognized to have an inherited defect in platelet function, therapy is important for controlling and preventing bleeding episodes. Presently, there are a number of choices to consider for the management of bleeding symptoms, including menorrhagia. This paper reviews the causes, diagnostic evaluation and therapies for common and rare congenital platelet disorders.


Assuntos
Transtornos Plaquetários/congênito , Transtornos Plaquetários/diagnóstico , Transtornos Plaquetários/terapia , Plaquetas/fisiologia , Humanos , Adesividade Plaquetária , Agregação Plaquetária
19.
J Thromb Haemost ; 4(2): 312-9, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16420557

RESUMO

BACKGROUND: Closure time (CT), measured by platelet function analyzer (PFA-100) device, is now available to the clinical laboratory as a possible alternative or supplement to the bleeding time test. AIM: On behalf of the Platelet Physiology Subcommittee of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis (ISTH-SSC), a working Group was formed to review and make recommendations on the use of the PFA-100 CT in the evaluation of platelet function within the clinical laboratory. METHODS: The Medline database was searched to review the published information on the PFA-100 CT in the evaluation of platelet disorders and platelet function. This information, and expert opinion, was used to prepare a report and generate consensus recommendations. RESULTS: Although the PFA-100 CT is abnormal in some forms of platelet disorders, the test does not have sufficient sensitivity or specificity to be used as a screening tool for platelet disorders. A role of the PFA-100 CT in therapeutic monitoring of platelet function remains to be established. CONCLUSIONS: The PFA-100 closure time should be considered optional in the evaluation of platelet disorders and function, and its use in therapeutic monitoring of platelet function is currently best restricted to research studies and prospective clinical trials.


Assuntos
Transtornos Plaquetários/diagnóstico , Testes de Função Plaquetária/instrumentação , Transtornos Plaquetários/sangue , Transtornos Plaquetários/congênito , Plaquetas/efeitos dos fármacos , Plaquetas/fisiologia , Ponte Cardiopulmonar/efeitos adversos , Doença das Coronárias/sangue , Hemorragia/sangue , Hemorragia/terapia , Humanos , Hepatopatias/sangue , Inibidores da Agregação Plaquetária/farmacologia , Contagem de Plaquetas , Uremia/sangue
20.
J Thromb Haemost ; 3(9): 2098-101, 2005 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16102118

RESUMO

Proteomic technology has the potential to transform the way we analyze platelet biology, through the determination of platelet protein composition and its modification upon stimulation and with disease. We are a considerable way from achieving these goals, however, because of significant limitations in current methodology. It is therefore important to consider the extent to which these aims can be met and the way that proteomic data should be presented and used. These issues are discussed in the present paper by the Platelet Physiology Subcommittee of the ISTH Scientific Standardisation Committee (SSC). It is recommended that proteomic information be combined with data from other experimental approaches to establish a database on protein expression and function in platelets.


Assuntos
Plaquetas/química , Proteoma , Bases de Dados de Proteínas , Guias como Assunto , Humanos , Proteômica/métodos
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