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1.
Eur J Endocrinol ; 186(4): 441-455, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35113805

RESUMO

BACKGROUND: Chronic wounds (e.g. diabetic foot ulcers) reduce the quality of life, yet treatments remain limited. Glucocorticoids (activated by the enzyme 11ß-hydroxysteroid dehydrogenase type 1, 11ß-HSD1) impair wound healing. OBJECTIVES: Efficacy, safety, and feasibility of 11ß-HSD1 inhibition for skin function and wound healing. DESIGN: Investigator-initiated, double-blind, randomized, placebo-controlled, parallel-group phase 2b pilot trial. METHODS: Single-center secondary care setting. Adults with type 2 diabetes mellitus without foot ulcers were administered 400 mg oral 11ß-HSD1 inhibitor AZD4017 (n = 14) or placebo (n = 14) bi-daily for 35 days. Participants underwent 3-mm full-thickness punch skin biopsies at baseline and on day 28; wound healing was monitored after 2 and 7 days. Computer-generated 1:1 randomization was pharmacy-administered. Analysis was descriptive and focused on CI estimation. Of the 36 participants screened, 28 were randomized. RESULTS: Exploratory proof-of-concept efficacy analysis suggested AZD4017 did not inhibit 24-h ex vivoskin 11ß-HSD1 activity (primary outcome; difference in percentage conversion per 24 h 1.1% (90% CI: -3.4 to 5.5) but reduced systemic 11ß-HSD1 activity by 87% (69-104%). Wound diameter was 34% (7-63%) smaller with AZD4017 at day 2, and 48% (12-85%) smaller after repeat wounding at day 30. AZD4017 improved epidermal integrity but modestly impaired barrier function. Minimal adverse events were comparable to placebo. Recruitment rate, retention, and data completeness were 2.9/month, 27/28, and 95.3%, respectively. CONCLUSION: A phase 2 trial is feasible, and preliminary proof-of-concept data suggests AZD4017 warrants further investigation in conditions of delayed healing, for example in diabetic foot ulcers. SIGNIFICANCE STATEMENT: Stress hormone activation by the enzyme 11ß-HSD type 1 impairs skin function (e.g. integrity) and delays wound healing in animal models of diabetes, but effects in human skin were previously unknown. Skin function was evaluated in response to treatment with a 11ß-HSD type 1 inhibitor (AZD4017), or placebo, in people with type 2 diabetes. Importantly, AZD4017 was safe and well tolerated. This first-in-human randomized, controlled, clinical trial found novel evidence that 11ß-HSD type 1 regulates skin function in humans, including improved wound healing, epidermal integrity, and increased water loss. Results warrant further studies in conditions of impaired wound healing, for example, diabetic foot ulcers to evaluate 11ß-HSD type 1 as a novel therapeutic target forchronic wounds.


Assuntos
11-beta-Hidroxiesteroide Desidrogenase Tipo 1/antagonistas & inibidores , Diabetes Mellitus Tipo 2/complicações , Pé Diabético/tratamento farmacológico , Niacinamida/análogos & derivados , Piperidinas/uso terapêutico , Pele/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Pé Diabético/patologia , Método Duplo-Cego , Epiderme/efeitos dos fármacos , Epiderme/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Niacinamida/uso terapêutico , Projetos Piloto , Qualidade de Vida , Pele/patologia , Pele/fisiopatologia , Resultado do Tratamento
2.
mBio ; 12(2)2021 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-33653882

RESUMO

Functional characterization of bacterial proteins lags far behind the identification of new protein families. This is especially true for bacterial species that are more difficult to grow and genetically manipulate than model systems such as Escherichia coli and Bacillus subtilis To facilitate functional characterization of mycobacterial proteins, we have established a Mycobacterial Systems Resource (MSR) using the model organism Mycobacterium smegmatis This resource focuses specifically on 1,153 highly conserved core genes that are common to many mycobacterial species, including Mycobacterium tuberculosis, in order to provide the most relevant information and resources for the mycobacterial research community. The MSR includes both biological and bioinformatic resources. The biological resource includes (i) an expression plasmid library of 1,116 genes fused to a fluorescent protein for determining protein localization; (ii) a library of 569 precise deletions of nonessential genes; and (iii) a set of 843 CRISPR-interference (CRISPRi) plasmids specifically targeted to silence expression of essential core genes and genes for which a precise deletion was not obtained. The bioinformatic resource includes information about individual genes and a detailed assessment of protein localization. We anticipate that integration of these initial functional analyses and the availability of the biological resource will facilitate studies of these core proteins in many Mycobacterium species, including the less experimentally tractable pathogens M. abscessus, M. avium, M. kansasii, M. leprae, M. marinum, M. tuberculosis, and M. ulceransIMPORTANCE Diseases caused by mycobacterial species result in millions of deaths per year globally, and present a substantial health and economic burden, especially in immunocompromised patients. Difficulties inherent in working with mycobacterial pathogens have hampered the development and application of high-throughput genetics that can inform genome annotations and subsequent functional assays. To facilitate mycobacterial research, we have created a biological and bioinformatic resource (https://msrdb.org/) using Mycobacterium smegmatis as a model organism. The resource focuses specifically on 1,153 proteins that are highly conserved across the mycobacterial genus and, therefore, likely perform conserved mycobacterial core functions. Thus, functional insights from the MSR will apply to all mycobacterial species. We believe that the availability of this mycobacterial systems resource will accelerate research throughout the mycobacterial research community.


Assuntos
Genes Bacterianos , Mycobacterium smegmatis/genética , Mycobacterium/genética , Pesquisa , Biologia Computacional , Biblioteca Gênica , Mycobacterium/classificação , Mycobacterium/patogenicidade , Mycobacterium smegmatis/crescimento & desenvolvimento
3.
Clin Radiol ; 75(9): 712.e13-712.e21, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32616296

RESUMO

AIM: To present the authors' experience of endovascular treatment of confirmed and presumed (microbiology negative) mycotic aortic aneurysms (MAA). MATERIALS AND METHODS: Patients undergoing endovascular aortic repair were identified retrospectively from 1998 using the radiology information system and an internally kept database until 2018. The primary aim was to assess the technical success and peri-operative morbidity and mortality. The secondary aim was to assess progression of infection, re-interventions, late mortality, and correlation to antibiotic duration pre- and post-procedure. RESULTS: Thirty-four endovascular aortic procedures were performed for MAA, excluding aorto-enteric fistulas, inflammatory aneurysms, and infected grafts without a new aneurysm. Seventy-six percent of these were thoracic and 24% abdominal. The technical success was 100%. Additional procedures were undertaken in four patients with two requiring a further endovascular procedure. There were two inpatient aneurysm-related mortalities and no inpatient conversions to open repair. The 30-day re-admission and re-intervention rate was 0%. Blood cultures were positive in 45%. There were no secondary graft infections. CONCLUSION: This is the largest European single-centre study. It supports endovascular management of MAA as a lower-risk alternative to open surgery with the majority of patients presenting acutely, later in life and requiring emergency management.


Assuntos
Aneurisma Infectado/cirurgia , Aneurisma Aórtico/cirurgia , Implante de Prótese Vascular/métodos , Procedimentos Endovasculares/métodos , Previsões , Stents , Idoso , Idoso de 80 Anos ou mais , Aneurisma Infectado/diagnóstico , Aneurisma Infectado/epidemiologia , Aneurisma Aórtico/diagnóstico , Feminino , Seguimentos , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Taxa de Sobrevida/tendências , Tomografia Computadorizada por Raios X , Ultrassonografia/métodos , Reino Unido/epidemiologia
4.
Bioinformatics ; 32(8): 1232-4, 2016 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-26704598

RESUMO

MOTIVATION: RNA interference (RNAi) technology is being developed as a weapon for pest insect control. To maximize the specificity that such an approach affords we have developed a bioinformatic web tool that searches the ever-growing arthropod transcriptome databases so that pest-specific RNAi sequences can be identified. This will help technology developers finesse the design of RNAi sequences and suggests which non-target species should be assessed in the risk assessment process. AVAILABILITY AND IMPLEMENTATION: http://rnai.specifly.org CONTACT: crobin@unimelb.edu.au.


Assuntos
Bases de Dados Genéticas , Internet , Interferência de RNA , Transcriptoma , Animais , Biologia Computacional , Insetos , Medição de Risco , Especificidade da Espécie
5.
Phys Rev Lett ; 113(10): 105001, 2014 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-25238364

RESUMO

The linear stability of multiple coherent laser beams with respect to two-plasmon-decay instability in an inhomogeneous plasma in three dimensions has been determined. Cooperation between beams leads to absolute instability of long-wavelength decays, while shorter-wavelength shared waves are shown to saturate convectively. The multibeam, in its absolutely unstable form, has the lowest threshold for most cases considered. Nonlinear calculations using a three-dimensional extended Zakharov model show that Langmuir turbulence created by the absolute instability modifies the convective saturation of the shorter-wavelength modes, which are seen to dominate at late times.

6.
Br Med Bull ; 104: 21-39, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23080419

RESUMO

INTRODUCTION: Peripheral arterial disease (PAD) is a common vascular condition that affects both quality of life and life expectancy with an increased risk of cardiovascular events. SOURCES OF DATA: A literature search was carried out of Pub-Med, MEDLINE, the Cochrane Library and Google Scholar from the establishment of these databases up to February 2012. The search was performed by using the keywords 'peripheral arterial disease' and one of the following words: 'management', 'investigations', 'risk factors', 'epidemiology', 'revascularization', 'cryoplasty', 'atherectomy' and 'gene therapy'. Studies were limited to those published in English language. AREAS OF AGREEMENT: Aggressive risk factors modification is needed to reduce cardiovascular-related mortality in PAD patients. AREAS OF CONTROVERSY: Choice of endovascular or surgical intervention remains controversial in an ever-evolving field. GROWING POINTS: There is a rapid expansion of endovascular technologies aiming to improve the effectiveness of this modality. AREAS TIMELY FOR DEVELOPING RESEARCH: The advances in the fields of gene therapy and therapeutic angiogenesis mean these are potential future treatments. Tissue engineering is a developing area and aims to produce grafts with similar patency and infection profiles to those of autologous material. Further elucidation of the pathophysiology of atherosclerosis is required to provide new targets for pharmacotherapy.


Assuntos
Aterectomia , Ponte de Artéria Coronária , Revascularização Miocárdica/métodos , Doenças Vasculares Periféricas/cirurgia , Doenças Vasculares Periféricas/terapia , Humanos , Doenças Vasculares Periféricas/mortalidade , Fatores de Risco
7.
Br J Surg ; 99(1): 6-15, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22068822

RESUMO

BACKGROUND: Peripheral arterial disease remains a significant global health burden despite revolutionary improvements in endovascular techniques over the past decade. The durability of intervention for critical limb ischaemia is poor, and the condition is associated with high morbidity and mortality rates. To address this deficiency, alternative therapeutic options are being explored. Advances in the fields of gene therapy and therapeutic angiogenesis have led to these being advocated as potential future treatments. METHODS: Relevant medical literature from PubMed, Embase, the Cochrane Library and Google Scholar from the inception of these databases to June 2011 was reviewed. RESULTS: Encouraging outcomes in preclinical trials using a variety of proangiogenic growth factors have led to numerous efficacy and safety studies. However, no clinical study has shown significant benefit for gene therapy over placebo. CONCLUSION: Identifying the optimal site for gene delivery, choice of vector and duration of treatment is needed if gene therapy is to become a credible therapeutic option for peripheral arterial disease.


Assuntos
Terapia Genética , Neovascularização Fisiológica/efeitos dos fármacos , Doença Arterial Periférica/genética , Doença Arterial Periférica/terapia , Proteínas de Ligação ao Cálcio , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Moléculas de Adesão Celular , Ensaios Clínicos Controlados como Assunto , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Terapia Genética/métodos , Vetores Genéticos , Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neovascularização Fisiológica/genética , Plasmídeos , Projetos de Pesquisa , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo , Vírus
8.
Phlebology ; 27(5): 231-4, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22037281

RESUMO

PURPOSE: The subgroup of patients with venous ulcers requiring anticoagulation for co-morbid conditions has traditionally created a therapeutic dilemma. Perioperative management of anticoagulation can be costly and increase the risk of surgical complications. This group of patients is often elderly and shows poor compliance with compression hosiery. The aim of this study was to investigate the outcome of endovenous laser ablation (EVLA) of the great saphenous vein (GSV) in patients remaining on therapeutic anticoagulation. MATERIALS AND METHODS: Fifteen consecutive patients (CEAP [clinical, aetiological, anatomical and pathological elements] classification 5 or 6) were treated with standard GSV EVLA using tumescent anaesthesia and a diode 1470-nm radial laser fibre while maintaining international normalized ratio at therapeutic levels. Clinical and duplex follow-up at six weeks and three, six and 12 months were performed. RESULTS: The GSV was successfully occluded in 14/15 (93%) of patients. The remaining patient had a second successful treatment three months later. No significant complications requiring intervention were encountered. CONCLUSION: EVLA using the diode 1470-nm radial fibre is efficacious with minimal complications in patients therapeutically anticoagulated. This treatment should be added to the armamentarium in this problematic patient group.


Assuntos
Anticoagulantes/administração & dosagem , Terapia a Laser/métodos , Lasers Semicondutores/uso terapêutico , Úlcera Varicosa/terapia , Varfarina/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Humanos , Terapia a Laser/efeitos adversos , Masculino , Pessoa de Meia-Idade , Assistência Perioperatória , Estudos Prospectivos , Úlcera Varicosa/classificação , Úlcera Varicosa/patologia , Varfarina/efeitos adversos
9.
Int J Food Microbiol ; 149(1): 88-105, 2011 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-21763022

RESUMO

It has been shown that the gut microbiota regulates fat storage in the body and that disturbances in its composition can lead to the development of certain metabolic disease states. Bifidobacteria are found among the resident microbiota in the gastrointestinal tract (GIT) and their metabolic activities have been shown to beneficially influence the human host. It has been reported that they inhibit intestinal colonisation by pathogenic microorganisms and have anti-carcinogenic, immunostimulatory, and anti-diarrhoeal properties, as well as aiding in the alleviation of lactose intolerance and ability to lower serum cholesterol levels in humans. One particular health promoting property of bifidobacteria is bioactive fatty acid production, which when ingested, may confer health benefits on the host. A bioactive fatty acid produced by bifidobacteria is conjugated linoleic acid (CLA), of which cis-9, trans-11 (c9, t11) and trans-10, cis-12 (t10, c12) CLA are the main biologically active CLA isomers. The production of CLA by Bifidobacterium can also have a positive effect on the immune system of the human host leading to numerous health benefits. This is an example of the metabolic activities of an ingested bacterium being beneficial to the host, rather than the direct interaction of the bacterium with the host.


Assuntos
Bifidobacterium/metabolismo , Ácidos Linoleicos Conjugados/metabolismo , Probióticos , Colesterol/metabolismo , Ácidos Graxos/metabolismo , Trato Gastrointestinal/metabolismo , Trato Gastrointestinal/microbiologia , Humanos , Isomerismo , Ácidos Linoleicos Conjugados/química
10.
Eur J Vasc Endovasc Surg ; 40(2): 186-90, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20434374

RESUMO

OBJECTIVES: Single centre series have suggested that endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysms (rAAA) may reduce mortality versus open surgery. This has not been substantiated in the only randomized controlled trial, leading to suggestion that anatomical suitability for rEVAR may independently improve prognosis of rAAA. Our aim was to assess the outcome of open rAAA repair in patients dependant on their suitability for rEVAR on pre-operative computed tomography (CT) assessment. METHODS: A retrospective review of all ruptured aneurysms presenting to our unit since January 1998 was performed. Patients were grouped based on anatomical suitability for rEVAR by pre-operative CT. RESULTS: Of 118 patients presenting with rAAA, 48 underwent pre-operative CT. Of these 9 scans had been "culled" and were excluded. 16 patients were suitable for rEVAR and 23 unsuitable. The groups were well matched demographically with no difference in Glasgow Aneurysm Score between groups. There was a non-significant trend towards reduction in 30-day mortality for patients suitable for EVAR (suitable 6.9% versus unsuitable 30.4%; P = 0.066) with no difference in operative time, transfusion requirement, length of stay or in-hospital morbidity. CONCLUSIONS: Anatomical suitability for EVAR seems to beneficially affect outcome following open repair for ruptured AAA. Further study is required to confirm these findings.


Assuntos
Aneurisma Roto/mortalidade , Aneurisma Roto/cirurgia , Aneurisma da Aorta Abdominal/mortalidade , Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular , Idoso , Idoso de 80 Anos ou mais , Aneurisma Roto/diagnóstico por imagem , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Bromoexina , Feminino , Humanos , Masculino , Seleção de Pacientes , Prognóstico , Radiografia , Estudos Retrospectivos , Resultado do Tratamento
11.
Eur J Vasc Endovasc Surg ; 39(2): 134-8, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19939712

RESUMO

BACKGROUND: Attempts to stratify carotid plaques according to clinical risk using single longitudinal view (SLV) echomorphology have not been uniformly successful. We compared SLV grey scale median measurements (SLV-GSM) with a newer technique of multiple cross-sectional view echomorphology (MCSV-GSM) in carotid plaques from 3 patient groups (asymptomatic, ocular, and hemispheric symptoms). METHODS: SLV and MCSV images were obtained from 109 carotid stenoses (70-99%; 41 hemispheric, 17 ocular, 51 asymptomatic). SLV-GSM and MCSV-GSM(min) (lowest plaque MCSV image GSM) were determined to assess echolucency whilst MCSV-GSM(max-min) (highest minus lowest MCSV-GSM) assessed heterogeneity. RESULTS: Echolucency was greater (lower GSM) in plaques causing hemispheric symptoms versus asymptomatic plaques (MCSV-GSM(min), P = .002; SLV-GSM, P = .002). Only MCSV imaging detected differences in echolucency between asymptomatic plaques and those causing ocular symptoms (SLV-GSM, p = 0.84; MCSV-GSM(min), p = .003). Symptomatic plaques showed greater heterogeneity versus asymptomatic plaques, significantly in those causing ocular symptoms (hemispheric P = .126; AF P = .011). CONCLUSIONS: Both SLV and MCSV echomorphology confirm increased echolucency in plaques causing hemispheric symptoms. Plaques causing ocular symptoms could only be distinguished from asymptomatic plaques with MCSV assessment (increased echolucency and heterogeneity). This suggests that amaurosis fugax may be associated with a more focal plaque instability that is best detected with MCSV imaging.


Assuntos
Estenose das Carótidas/diagnóstico por imagem , Ultrassonografia Doppler Dupla/métodos , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Estenose das Carótidas/patologia , Distribuição de Qui-Quadrado , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas
12.
Cells Tissues Organs ; 191(4): 307-15, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-19940435

RESUMO

The cranial suspensory ligament (CSL) is a fibromuscular structure anchoring the embryonic gonad to the posterior abdominal wall in male and female mammals. Its persistence in females is believed to be responsible for retaining the ovaries within the abdomen, while its regression in males permits testis descent. Embryonic loss of the CSL in males is believed to be an androgen-dependent event, and failure of this process has been proposed as a cause of cryptorchidism. The present study demonstrates that the nuclei of mesenchymal cells in the caudal part of the CSL are immunoreactively positive for androgen receptor. We examined the effects of exposure of the non-steroidal antiandrogen flutamide during the period from gestational day 10 to birth on the development of the CSL and on testis descent. Exposure of male Albino Swiss rats to the antiandrogen flutamide during this period resulted in feminization of the external genitalia and the suppression of growth of the testes and male reproductive tracts. In adulthood, testes were found to be located in diverse positions including normal scrotal (50%), intra-abdominal (10%) and ectopic suprainguinal (40%). The CSL of the testis persisted into adulthood in all flutamide-treated males, regardless of testis location. In all cases, the ligament consisted of bundles of smooth muscle fibres in the retroperitoneal fat of the posterior abdominal wall. These findings suggest that androgen blockade during embryonic development interferes with testicular descent, but that maldescent cannot be correlated with either the persistence of the CSL of the testis or its structure.


Assuntos
Criptorquidismo/embriologia , Testículo/embriologia , Animais , Criptorquidismo/metabolismo , Flutamida , Gônadas/embriologia , Gônadas/crescimento & desenvolvimento , Masculino , Microscopia Acústica , Ratos , Testículo/crescimento & desenvolvimento
13.
Bull Entomol Res ; 98(6): 599-603, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18631420

RESUMO

The four significant pest species in the Helicoverpa genus (H. armigera, H. assulta, H. punctigera and H. zea) are morphologically similar and can only be reliably distinguished through dissection of adult genitalia. Two partial regions of the mitochondrial DNA (mtDNA), the cytochrome oxidase subunit I (COI) and the cytochrome b (Cyt b) genes were amplified by PCR and digested with restriction endonucleases. The restriction patterns, generated by the endonucleases BstZ17I and HphI, demonstrated reliable differentiation of the four Helicoverpa pest species. This technique is fast, reliable and effective at distinguishing specimens irrespective of their life stages and offers support to conventional taxonomic differentiation based on morphological characters.


Assuntos
Mariposas/genética , Animais , Classificação/métodos , Citocromos b/química , Citocromos b/genética , DNA Mitocondrial/química , Complexo IV da Cadeia de Transporte de Elétrons/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Marcadores Genéticos , Haplótipos , Mariposas/anatomia & histologia , Mariposas/classificação , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Mapeamento por Restrição
14.
Br J Surg ; 95(5): 576-81, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18344184

RESUMO

BACKGROUND: Vascular endothelial growth factor (VEGF) promotes events favouring carotid plaque instability: inflammatory chemoattraction, thrombogenesis, and upregulation of matrix metalloproteinases and cell adhesion molecules. The aim of this study was to assess neovascularization, VEGF and its receptors in high-grade stable and unstable carotid plaques. METHODS: Immunohistochemical staining for CD34, VEGF, VEGF receptor (VEGFR) 1 and VEGFR2 was performed in 34 intact carotid endarterectomy specimens, and compared in sections demonstrating maximal histological instability (cap rupture/thinning) or, if stable, maximal stenosis. RESULTS: VEGF staining was increased in 12 unstable compared with 22 stable plaques (median (interquartile range, i.q.r.) plaque score 4.0 (4.0-4.0) versus 3.0 (2.0-3.0); P = 0.002) with upregulation of VEGFR1 (plaque score 4.0 (2.0-4.0) versus 2.0 (1.0-3.0); P = 0.016). In unstable plaques this was associated with increased microvessel density in the cap (median (i.q.r.) 12.1 (4.0-30.0) versus 1.1 (0.0-7.3) microvessels/mm(2); P = 0.017) and shoulder regions (7.7 (3.4-21.4) versus 3.1 (0.4-10.8) microvessels/mm(2); P = 0.176). CONCLUSION: Increased VEGF and receptor staining were seen in histologically unstable carotid plaques. Although these differences could reflect cytokine-driven inflammatory events accompanying plaque instability, VEGF and VEGFR1 could be key mediators.


Assuntos
Estenose das Carótidas/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Idoso , Idoso de 80 Anos ou mais , Antígenos CD34/metabolismo , Estenose das Carótidas/metabolismo , Estenose das Carótidas/fisiopatologia , Feminino , Humanos , Imuno-Histoquímica , Macrófagos/metabolismo , Masculino , Microcirculação , Pessoa de Meia-Idade , Neovascularização Fisiológica/fisiologia , Variações Dependentes do Observador , Receptores de Fatores de Crescimento do Endotélio Vascular/metabolismo
15.
Eur J Vasc Endovasc Surg ; 28(2): 115-23, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15234690

RESUMO

OBJECTIVES: To determine risk factors for the development of hyperperfusion and intra-cerebral haemorrhage following carotid endarterectomy and formulate potential protocols for prevention. METHODS: MEDLINE database search of the English language literature (1966-2002) was performed using the words 'cerebral haemorrhage', 'intracranial haemorrhage' and 'carotid endarterectomy'. Other articles were cross-referenced by hand. RESULTS: There are no data from randomised trials confirming the significance of any single risk factor. The evidence suggests that the following may have a role: pre-operative hypertension, recent ipsilateral non-haemorrhagic stroke, previous ischaemic cerebral infarction, surgery for a > 90% ipsilateral internal carotid artery (ICA) stenosis, impaired cerebrovascular reserve, intra-operative haemodynamic or embolic ischaemia, post-operative hypertension, an ipsilateral increase of > or =175% in peak middle cerebral artery velocity (MCAV) and/or a > or =100% increase in pulsatility index. CONCLUSIONS: A critical ICA stenosis with impaired cerebrovascular reserve resulting in maximal intracerebral vasodilatation and post-operative hyperperfusion (impaired autoregulation) appear to be central to the development of ICH. Appropriate pre-operative screening and post-operative monitoring in high risk patients might identify those who would benefit from manipulation of the haemodynamic events that appear to promote ICH.


Assuntos
Hemorragia Cerebral/etiologia , Endarterectomia das Carótidas/efeitos adversos , Pressão Sanguínea , Artéria Carótida Interna/patologia , Estenose das Carótidas/cirurgia , Hemorragia Cerebral/fisiopatologia , Circulação Cerebrovascular , Humanos , Monitorização Intraoperatória , Medição de Risco , Fatores de Risco , Vasodilatação
16.
Phys Rev Lett ; 93(26 Pt 1): 265001, 2004 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-15697984

RESUMO

Propagating filaments of enhanced plasma density, or blobs, observed in 3D numerical simulations of a diverted, neutral-fueled tokamak are studied. Fluctuations of vorticity, electrical potential phi, temperature Te, and current density J parallel associated with the blobs have a dipole structure perpendicular to the magnetic field and propagate radially with large E x B drift velocities (>1 km/s). The simulation results are consistent with a 3D blob dynamics model that incorporates increased parallel plasma resistivity (from neutral cooling of the X-point region), blob disconnection from the divertor sheath, X-point closure of the current loops, and collisional physics to sustain the phi, Te, J parallel dipoles.

18.
Phys Rev Lett ; 87(15): 155001, 2001 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-11580704

RESUMO

A diffraction-limited laser interacts with a plasma whose conditions are uniform on the scale of the focused laser spot. Two distinct, narrow waves are observed in the backscattered spectrum with phase velocities of v(phi)/v(e) = 1.4+/-0.08 and 4.2+/-0.1, where v(e) is the electron thermal speed. The high-velocity wave is ordinary stimulated Raman scattering (SRS) from a Langmuir wave. The low-velocity wave corresponds to stimulated scattering from an electron-acoustic wave (SEAS), and implies strong electron trapping. Previous SRS data from low-density plasmas are reinterpreted in terms of SEAS.

19.
Pharm Res ; 18(2): 166-70, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11405286

RESUMO

PURPOSE: To determine the pharmacokinetics and absolute bioavailability of risedronate after single-dose oral administration of 30 mg risedronate as a tablet and an aqueous solution, and 0.3 mg risedronate as an intravenous infusion. METHODS: This study was a randomized, three-treatment, four-period, partial replicate crossover study involving 33 healthy volunteers. Treatments were administered 7 weeks apart, and the third treatment was repeated during the fourth period. Serum and urine were collected over 72 hours and 672 hours, respectively. RESULTS: Following intravenous administration, renal clearance accounted for 87% of total clearance, with 65% of the dose excreted within 24 hours and 85% of the dose excreted within four weeks. The absolute bioavailability was approximately 0.62% after both oral formulations, and the relative bioavailability of the tablet compared with the oral solution was 104%. The rate and extent of absorption from the two formulations were bioequivalent based on the range proposed for highly variable drugs. Intrasubject variability following oral administration was 50-80%, and was primarily associated with absorption. CONCLUSION: The majority of the total clearance after intravenous administration of risedronate was renal clearance, indicating that only a small percentage of a systemic dose is potentially incorporated, or "cleared," into bone. The absolute bioavailability of orally administered risedronate is approximately 0.6%, and is independent of formulation. Variability in the pharmacokinetics following oral administration is primarily associated with intrasubject variability in absorption.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacocinética , Ácido Etidrônico/análogos & derivados , Ácido Etidrônico/farmacocinética , Administração Oral , Adulto , Análise de Variância , Área Sob a Curva , Estudos Cross-Over , Feminino , Humanos , Infusões Intravenosas , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Ácido Risedrônico
20.
Cell Mol Life Sci ; 58(2): 165-78, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11289299

RESUMO

Prokaryotic nitrate reduction can serve a number of physiological roles and can be catalysed by a number of biochemically distinct nitrate reductases. Three distinct nitrate reductase classes can be indentified in prokaryotes, NAS, NAR and NAP. NAS is located in the cytoplasmic compartment and participates in nitrogen assimilation. NAR is usually a three-subunit complex anchored to the cytoplasmic face of the membrane with its active site located in the cytoplasmic compartment and is involved in anaerobic nitrate respiration. NAP is a two-subunit complex, located in the periplasmic compartment, that is coupled to quinol oxidation via a membrane anchored tetraheme cytochrome. It shows considerable functional flexibility by participating in anaerobic respiration or redox energy dissipation depending on the organism in which it is found. The members of all three classes of enzymes bind the bis-molybdopterin guanine dinucleotide cofactor at the active site, but they differ markedly in the number and nature of cofactors used to transfer electrons to this site. Analysis of prokaryotic genome sequences available at the time of writing reveals that the different nitrate reductases are phylogenetically widespread.


Assuntos
Nitrato Redutases/metabolismo , Sequência de Aminoácidos , Archaea/enzimologia , Archaea/genética , Azotobacter vinelandii/enzimologia , Azotobacter vinelandii/genética , Bacillus subtilis/enzimologia , Bacillus subtilis/genética , Cianobactérias/enzimologia , Cianobactérias/genética , Evolução Molecular , Genes Arqueais , Genes Bacterianos , Variação Genética , Klebsiella/enzimologia , Klebsiella/genética , Dados de Sequência Molecular , Família Multigênica , Nitrato Redutase , Nitrato Redutases/química , Nitrato Redutases/genética , Paracoccus/enzimologia , Paracoccus/genética , Células Procarióticas/enzimologia , Subunidades Proteicas , Homologia de Sequência de Aminoácidos
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