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1.
Nature ; 607(7917): 74-80, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35794267

RESUMO

Vortices are the hallmarks of hydrodynamic flow. Strongly interacting electrons in ultrapure conductors can display signatures of hydrodynamic behaviour, including negative non-local resistance1-4, higher-than-ballistic conduction5-7, Poiseuille flow in narrow channels8-10 and violation of the Wiedemann-Franz law11. Here we provide a visualization of whirlpools in an electron fluid. By using a nanoscale scanning superconducting quantum interference device on a tip12, we image the current distribution in a circular chamber connected through a small aperture to a current-carrying strip in the high-purity type II Weyl semimetal WTe2. In this geometry, the Gurzhi momentum diffusion length and the size of the aperture determine the vortex stability phase diagram. We find that vortices are present for only small apertures, whereas the flow is laminar (non-vortical) for larger apertures. Near the vortical-to-laminar transition, we observe the single vortex in the chamber splitting into two vortices; this behaviour is expected only in the hydrodynamic regime and is not anticipated for ballistic transport. These findings suggest a new mechanism of hydrodynamic flow in thin pure crystals such that the spatial diffusion of electron momenta is enabled by small-angle scattering at the surfaces instead of the routinely invoked electron-electron scattering, which becomes extremely weak at low temperatures. This surface-induced para-hydrodynamics, which mimics many aspects of conventional hydrodynamics including vortices, opens new possibilities for exploring and using electron fluidics in high-mobility electron systems.

2.
Brain Struct Funct ; 218(1): 59-72, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22246100

RESUMO

Diverse stress stimuli induce long-lasting cognitive deficits, but the underlying molecular mechanisms are still incompletely understood. Here, we report three different stress models demonstrating that stress-inducible increases in microRNA-132 (miR-132) and consequent decreases in its acetylcholinesterase (AChE) target are causally involved. In a mild model of predator scent-induced anxiety, we demonstrate long-lasting hippocampal elevation of miR-132, accompanied by and associated with reduced AChE activity. Using lentiviral-mediated suppression of "synaptic" AChE-S mRNA, we quantified footshock stress-inducible changes in miR-132 and AChE and its corresponding cognitive damages. Stressed mice showed long-lasting impairments in the Morris water maze. In contrast, pre-stress injected AChE-suppressing lentivirus, but not a control virus, reduced hippocampal levels of both miR-132 and AChE and maintained similar cognitive performance to that of naïve, non-stressed mice. To dissociate between miR-132 and synaptic AChE-S as potential causes for stress-inducible cognitive deficits, we further used engineered TgR mice with enforced over-expression of the soluble "readthrough" AChE-R variant without the 3'-untranslated region binding site for miR-132. TgR mice displayed excess AChE-R in hippocampal neurons, enhanced c-fos labeling and correspondingly intensified reaction to the cholinergic agonist pilocarpine. They further showed excessive hippocampal expression of miR-132, accompanied by reduced host AChE-S mRNA and the GTPase activator p250GAP target of miR-132. At the behavioral level, TgR mice showed abnormal nocturnal locomotion patterns and serial maze mal-performance in spite of their reduced AChE-S levels. Our findings attribute stress-inducible cognitive impairments to cholinergic-mediated induction of miR-132 and consequently suppressed ACHE-S, opening venues for intercepting these miR-132-mediated damages.


Assuntos
Acetilcolinesterase/metabolismo , Transtornos Cognitivos/etiologia , Cognição , Hipocampo/enzimologia , MicroRNAs/metabolismo , Estresse Psicológico/complicações , Regiões 3' não Traduzidas , Acetilcolinesterase/genética , Animais , Sítios de Ligação , Células Cultivadas , Cognição/efeitos dos fármacos , Transtornos Cognitivos/enzimologia , Transtornos Cognitivos/genética , Transtornos Cognitivos/prevenção & controle , Transtornos Cognitivos/psicologia , Regulação para Baixo , Eletrochoque/psicologia , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Regulação Enzimológica da Expressão Gênica , Hipocampo/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Atividade Motora , Agonistas Muscarínicos/farmacologia , Pilocarpina/farmacologia , Comportamento Predatório , Interferência de RNA , RNA Mensageiro/metabolismo , Estresse Psicológico/enzimologia , Estresse Psicológico/genética , Estresse Psicológico/psicologia , Sinapses/enzimologia , Transfecção , Regulação para Cima
3.
J Cardiovasc Surg (Torino) ; 52(5): 669-81, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21796091

RESUMO

The Endurant Stent-graft System (Medtronic Vascular, Santa Rosa, CA) is a next-generation device intended to expand the applicability of endovascular aortic repair (EVAR). To date, the Endurant has been evaluated in 9 short- and intermediate-term studies, several in patients presenting with challenging aneurysm anatomies. Consistently, the device in these studies has been shown to be safe and effective, with an excellent rate of deployment success and with very low rates of type I/III endoleaks and reinterventions. Single center experience with Endurant in challenging anatomies with short kinked necks and calcified angulated iliac arteries in patients unfit for open repair and challenging anatomies show promising early results with no difference in mortality, morbidity and reintervention rates, but need cautious application for EVAR outside of the device-specific IFU. The Endurant Stent-graft Natural Selection Global Postmarket Registry (ENGAGE) is a long-term 1266-patient 80-site worldwide prospective postmarket study initiated to augment the knowledge base (poolable and comparable) about EVAR in a real-world population implanted with the Endurant. Technical and clinical data for ENGAGE patients will be reported through the expected completion of 5-year follow-up for all ENGAGE registry patients in 2018. We discuss the evolving challenges for EVAR that the Endurant and other next-generation stent-grafts are designed to address and review outcomes published with the Endurant since the CE marking of the device in July 2008.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Procedimentos Endovasculares/instrumentação , Stents , Implante de Prótese Vascular/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Medicina Baseada em Evidências , Humanos , Seleção de Pacientes , Guias de Prática Clínica como Assunto , Desenho de Prótese , Medição de Risco , Resultado do Tratamento
4.
J Cardiovasc Surg (Torino) ; 51(4): 481-91, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20671632

RESUMO

AIM: The Endurant Stent Graft Natural Selection Global Postmarket Registry (ENGAGE) is a long-term 1200-patient multicenter prospective study initiated to augment the knowledge base (poolable and comparable) about endovascular aortic repair (EVAR) in a real-world population implanted with a single latest-generation stent graft system (Endurant). With enrollment ongoing at 80 high-volume sites, the registry has limited inclusion/exclusion criteria or procedural specification. Technical and clinical data will be reported through 5 years. METHODS: An interim analysis was performed on investigator-reported data for the first 180 patients enrolled. These patients were asymptomatic elderly males (92.1%) with considerable comorbidities. For 47.3% of the patients, the American Society of Anesthesiologists risk class was either III or IV. The Endurant stent graft was successfully deployed in 99.4% of patients for elective treatment of abdominal aortic aneurysm. RESULTS: Through 30 days, the rate of all-cause mortality was 1.7% (N=3), with all 3 deaths classified as procedure-related but not device-related. The rate of secondary endovascular procedures was 1.1%, and the rate of conversion to open repair was 0.6%. At postprocedure and at 30-day follow-up, there were no type I or type III endoleaks and no instances of stent graft kinking, thrombosis, or occlusion. ENGAGE represents the largest real-world registry for any single EVAR stent graft. CONCLUSION: The interim results through 30 days of the first 180 patients enrolled are promising. Longer-term follow-up for more patients will be reported.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Implante de Prótese Vascular/instrumentação , Prótese Vascular , Procedimentos Endovasculares/instrumentação , Vigilância de Produtos Comercializados , Sistema de Registros , Projetos de Pesquisa , Stents , Idoso , Idoso de 80 Anos ou mais , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/mortalidade , Aortografia/métodos , Austrália , Implante de Prótese Vascular/efeitos adversos , Implante de Prótese Vascular/mortalidade , Brasil , Procedimentos Cirúrgicos Eletivos , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/mortalidade , Europa (Continente) , Feminino , Humanos , Israel , Estimativa de Kaplan-Meier , Masculino , Estudos Prospectivos , Desenho de Prótese , Reoperação , Medição de Risco , Fatores de Risco , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do Tratamento
5.
Artigo em Inglês | MEDLINE | ID: mdl-19687142

RESUMO

Extensive horizontal gene transfer (HGT) among prokaryotes seems to undermine the tree of life (TOL) concept. However, the possibility remains that the TOL can be salvaged as a statistical central trend in the phylogenetic "forest of life" (FOL). A comprehensive comparative analysis of 6901 phylogenetic trees for prokaryotic genes revealed a signal of vertical inheritance that was particularly strong among the 102 nearly universal trees (NUTs), despite the high topological inconsistency among the trees in the FOL, most likely, caused by HGT. The topologies of the NUTs are similar to the topologies of numerous other trees in the FOL; although the NUTs cannot represent the FOL completely, they reflect a significant central trend. Thus, the original TOL concept becomes obsolete but the idea of a "weak" TOL as the dominant trend in the FOL merits further investigation. The totality of gene trees comprising the FOL appears to be a natural representation of the history of life given the inherent tree-like character of the replication process.


Assuntos
Modelos Genéticos , Filogenia , Evolução Biológica , Transferência Genética Horizontal , Metagenômica , Células Procarióticas
6.
J Gen Virol ; 90(Pt 10): 2525-2535, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19535502

RESUMO

Ourmia melon virus (OuMV), Epirus cherry virus (EpCV) and Cassava virus C (CsVC) are three species placed in the genus Ourmiavirus. We cloned and sequenced their RNA genomes. The sizes of the three genomic RNAs of OuMV, the type member of the genus, were 2814, 1064 and 974 nt and each had one open reading frame. RNA1 potentially encoded a 97.5 kDa protein carrying the GDD motif typical of RNA-dependent RNA polymerases (RdRps). The putative RdRps of ourmiaviruses are distantly related to known viral RdRps, with the closest similarity and phylogenetic affinity observed with fungal viruses of the genus Narnaviridae. RNA2 encoded a 31.6 kDa protein which, expressed in bacteria as a His-tag fusion protein and in plants through agroinfiltration, reacted specifically with antibodies made against tubular structures found in the cytoplasm. The ORF2 product is significantly similar to movement proteins of the genus Tombusviridae, and phylogenetic analysis supported this evolutionary relationship. The product of OuMV ORF3 is a 23.8 kDa protein. This protein was also expressed in bacteria and plants, and reacted specifically with antisera against the OuMV coat protein. The sequence of the ORF3 protein showed limited but significant similarity to capsid proteins of several plant and animal viruses, although phylogenetic analysis failed to reveal its most likely origin. Taken together, these results indicate that ourmiaviruses comprise a unique group of plant viruses that might have evolved by reassortment of genomic segments of RNA viruses infecting hosts belonging to different eukaryotic kingdoms, in particular, fungi and plants.


Assuntos
Vírus de Plantas/genética , Vírus Reordenados/genética , Sequência de Bases , Escherichia coli/metabolismo , Regulação Viral da Expressão Gênica/fisiologia , Genoma Viral , Dados de Sequência Molecular , Filogenia , Folhas de Planta/metabolismo , RNA Viral/genética , Nicotiana/metabolismo
7.
Proc Natl Acad Sci U S A ; 103(42): 15611-6, 2006 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-17030793

RESUMO

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.


Assuntos
Genoma Bacteriano , Genômica , Ácido Láctico/metabolismo , Lactobacillus/genética , Streptococcaceae/genética , Animais , Proteínas de Bactérias/classificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Evolução Biológica , Microbiologia de Alimentos , Transferência Genética Horizontal , Lactobacillus/classificação , Filogenia , Streptococcaceae/classificação
9.
BMC Evol Biol ; 1: 8, 2001 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-11734060

RESUMO

BACKGROUND: The availability of multiple complete genome sequences from diverse taxa prompts the development of new phylogenetic approaches, which attempt to incorporate information derived from comparative analysis of complete gene sets or large subsets thereof. Such attempts are particularly relevant because of the major role of horizontal gene transfer and lineage-specific gene loss, at least in the evolution of prokaryotes. RESULTS: Five largely independent approaches were employed to construct trees for completely sequenced bacterial and archaeal genomes: i) presence-absence of genomes in clusters of orthologous genes; ii) conservation of local gene order (gene pairs) among prokaryotic genomes; iii) parameters of identity distribution for probable orthologs; iv) analysis of concatenated alignments of ribosomal proteins; v) comparison of trees constructed for multiple protein families. All constructed trees support the separation of the two primary prokaryotic domains, bacteria and archaea, as well as some terminal bifurcations within the bacterial and archaeal domains. Beyond these obvious groupings, the trees made with different methods appeared to differ substantially in terms of the relative contributions of phylogenetic relationships and similarities in gene repertoires caused by similar life styles and horizontal gene transfer to the tree topology. The trees based on presence-absence of genomes in orthologous clusters and the trees based on conserved gene pairs appear to be strongly affected by gene loss and horizontal gene transfer. The trees based on identity distributions for orthologs and particularly the tree made of concatenated ribosomal protein sequences seemed to carry a stronger phylogenetic signal. The latter tree supported three potential high-level bacterial clades,: i) Chlamydia-Spirochetes, ii) Thermotogales-Aquificales (bacterial hyperthermophiles), and ii) Actinomycetes-Deinococcales-Cyanobacteria. The latter group also appeared to join the low-GC Gram-positive bacteria at a deeper tree node. These new groupings of bacteria were supported by the analysis of alternative topologies in the concatenated ribosomal protein tree using the Kishino-Hasegawa test and by a census of the topologies of 132 individual groups of orthologous proteins. Additionally, the results of this analysis put into question the sister-group relationship between the two major archaeal groups, Euryarchaeota and Crenarchaeota, and suggest instead that Euryarchaeota might be a paraphyletic group with respect to Crenarchaeota. CONCLUSIONS: We conclude that, the extensive horizontal gene flow and lineage-specific gene loss notwithstanding, extension of phylogenetic analysis to the genome scale has the potential of uncovering deep evolutionary relationships between prokaryotic lineages.


Assuntos
Bactérias/classificação , Bactérias/genética , Evolução Molecular , Genoma Bacteriano , Genômica/métodos , Filogenia , Sequência Conservada/genética , Ordem dos Genes/genética , Transferência Genética Horizontal , Genes Arqueais/genética , Genes Bacterianos/genética , Genoma Arqueal , Funções Verossimilhança , Células Procarióticas/metabolismo , Proteínas Ribossômicas/genética , Alinhamento de Sequência , Especificidade da Espécie
11.
Burns ; 27(8): 853-5, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11718990

RESUMO

Different types of injuries are described as caused by the use of microwave ovens. Four of 41 burns from microwave ovens, presented by an international survey in 1986, were due to exploding microwave-heated eggs. Careful review of the English language literature through a Medline search from 1966 to 2000 was performed, in search of burns caused by exploding eggs. Clinical information from the published articles was reviewed and missing information was completed by e-mail correspondence with authors. Our own case was added to the collected data, and a total of 13 cases were analyzed. The average age of patients was 24.3 years (range, 7-49 years). All patients suffered from superficial burns of the mid and upper face, namely the forehead, periorbital region, dorsum of nose and malar areas. All patients with information available complained of ocular disturbances, and three suffered long-term decrease in visual acuity. Long-term skin complications were not reported. In summary, the clinical presentation of a facial injury from an exploding microwave-heated egg is relatively constant and mild. Favorable outcome can be expected but a meticulous ophthalmologic evaluation and a close follow-up are mandatory for prevention of long-term sequelae.


Assuntos
Queimaduras/etiologia , Traumatismos Faciais/etiologia , Micro-Ondas/efeitos adversos , Adolescente , Adulto , Distribuição por Idade , Queimaduras/epidemiologia , Criança , Ovos , Queimaduras Oculares/epidemiologia , Queimaduras Oculares/etiologia , Traumatismos Faciais/epidemiologia , Traumatismos Faciais/terapia , Feminino , Humanos , Incidência , Escala de Gravidade do Ferimento , Israel/epidemiologia , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Fatores de Risco , Distribuição por Sexo
12.
J Vasc Surg ; 34(4): 594-9, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11668310

RESUMO

OBJECTIVE: The purpose of this study was to examine the effect of aortoiliac tortuosity, as assessed by observers and 3-dimensional (3D) computer-based methods, on the conduct and outcome of endovascular repair of abdominal aortic aneurysms. METHODS: Infrarenal aortoiliac tortuosity was measured in 75 patients (mean follow-up, 14.8 +/- 10.4 months) who underwent endovascular repair of abdominal aortic aneurysms by using the following four methods: (1) grading by 2 experienced observers; (2) tortuosity index measured as the inverse radius of curvature (cm(-1)) at 1-mm intervals along the median luminal centerline (MLC) on 3D reconstructions of computed tomography (CT) angiograms and was calculated as the sum of values greater than 0.3 cm(-1); (3) MLC-straight line length ratio from renal to hypogastric arteries; (4) manual measurement of angles at points of angulation on anteroposterior and lateral projections of 3D CT reconstructions. In evaluating association between these measures, correlation between human observers was accepted as the gold standard. RESULTS: For rating of overall aortoiliac tortuosity, interobserver correlation (r = 0.67) was comparable with correlation of observers with tortuosity index (r = 0.67 and 0.56), whereas correlations of each observer with MLC-straight line ratio (r = 0.50 and 0.56) and cumulative angulation (r = 0.44 and 0.44) were significant but weaker. For determining the relative tortuosity of right and left aortoiliac access, agreement between observers and tortuosity index (54% and 58%; P < .05; kappa, 0.33 and 0.38) was not as good as between observers (68%; P < .001; kappa, 0.53). This difference was primarily related to evaluation of the aorta, where interobserver correlation (r = 0.71) was better than that between each observer and tortuosity index (r = 0.47 and 0.55), whereas correlations in the iliac arteries were comparable (r = 0.64 and 0.67) (all coefficients P < .01). Increased tortuosity was associated with a more complex endovascular repair, as reflected by longer fluoroscopy time (P = .05), use of more contrast material (P = .03), use of extender modules (P = .04), and more frequent use of arterial reconstruction (P = .01), but was not associated with a higher overall complication rate. Increased tortuosity, when it occurred in the aortic neck, was associated with predischarge endoleak (P = .03) but not with late endoleak, intervention, or aneurysm-related adverse events. CONCLUSION: Aortoiliac tortuosity is associated with increased complexity of endovascular aneurysm repair and with predischarge endoleak but does not appear to affect intermediate-term results. Computer-based 3D measurement of aortoiliac tortuosity is feasible and clinically meaningful. Its ultimate role in relation to human assessment must be further defined in future studies.


Assuntos
Angioplastia/métodos , Aneurisma da Aorta Abdominal/complicações , Aneurisma da Aorta Abdominal/cirurgia , Doenças da Aorta/complicações , Doenças da Aorta/diagnóstico por imagem , Arteriosclerose/complicações , Arteriosclerose/diagnóstico por imagem , Artéria Ilíaca , Imageamento Tridimensional/métodos , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X/métodos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Angioplastia/efeitos adversos , Doenças da Aorta/classificação , Arteriosclerose/classificação , Meios de Contraste , Estudos de Viabilidade , Seguimentos , Humanos , Imageamento Tridimensional/instrumentação , Imageamento Tridimensional/normas , Pessoa de Meia-Idade , Variações Dependentes do Observador , Seleção de Pacientes , Estudos Retrospectivos , Stents , Fatores de Tempo , Tomografia Computadorizada por Raios X/instrumentação , Tomografia Computadorizada por Raios X/normas , Resultado do Tratamento
13.
Isr Med Assoc J ; 3(9): 649-52, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11574979

RESUMO

BACKGROUND: Pseudoaneurysm occurring after catheterization of the femoral artery is associated with significant morbidity. Percutaneous ultrasound-guided thrombin injection has recently emerged as a potential first-line therapy. OBJECTIVES: To evaluate the efficacy of this treatment in eight patients with iatrogenic femoral artery pseudoaneurysm. METHODS: After attempted treatment with external compression had failed, eight patients with iatrogenic femoral artery pseudoaneurysm were treated with thrombin injection. Treatment performed between 2 and 9 days following arterial puncture. The study group comprised seven males and one female ranging in age from 23 to 89 years (median 70). Seven had undergone cardiac catheterization with or without intervention, and five were receiving antiplatelet and/or anticoagulant drugs. Arterial pseudoaneurysm resulted from femoral vein catheterization in one patient. Using a sterile technique and real-time Doppler ultrasound guidance, a dilute solution of bovine thrombin (average dose 250 units, range 100-600), was slowly injected directly into the pseudoaneurysm until cessation of flow was seen. Patients were allowed to walk within 2 hours of the procedure and were followed up clinically and by color Doppler ultrasound during the admission. RESULTS: Cardiac catheterization had been inadvertently performed via the superficial or profunda femoris arteries in four of the eight patients. Thrombin injection was initially successful in all eight patients without complication. Thrombosis occurred immediately in every case. Early recanalization of pseudoaneurysm occurred in one patient despite repeat thrombin injection and attempted ultrasound-guided compression. He eventually required surgical repair. The final success rate was 87.5% (7/8). CONCLUSION: Faulty puncture technique is an important risk factor for the development of post-catheterization femoral artery pseudoaneurysm. Ultrasound-guided thrombin injection is a safe, rapid, well-tolerated, inexpensive and successful therapy. If initial external compression with a sandbag fails to result in thrombosis of the pseudoaneurysm then thrombin injection should be considered as first-line therapy. If unsuccessful, it does not preclude the use of alternative treatment modalities. Further study is necessary to assess the long-term effects of thrombin injection.


Assuntos
Falso Aneurisma/tratamento farmacológico , Artéria Femoral/diagnóstico por imagem , Hemostáticos/uso terapêutico , Trombina/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Falso Aneurisma/etiologia , Cateterismo Cardíaco/efeitos adversos , Feminino , Hemostáticos/administração & dosagem , Humanos , Injeções Intra-Arteriais , Masculino , Trombina/administração & dosagem , Ultrassonografia
14.
Plast Reconstr Surg ; 108(2): 348-51, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11496173

RESUMO

Gynecomastia is a common deformity encountered by plastic surgeons. The appropriate location of the nipple-areola complex is a major determinant of the aesthetic success of the procedure. To study the natural location of the nipple-areola complex in the normally built male, 50 nonobese men with no evidence of gynecomastia and an average age of 27.9 years were examined. Three ratios were calculated and found to be relatively constant; they were the ratio between the height of the nipple and the height of the patient, the ratio between the distance between the nipples and chest circumference, and the ratio between the suprasternal notch-to-nipple distance and the height of the patient. Using these three parameters, a method of locating the nipple-areola complex on the male chest wall was devised. The method is advocated as a reliable, simple, and useful technique.


Assuntos
Mamilos/anatomia & histologia , Adolescente , Adulto , Antropometria , Estatura , Peso Corporal , Ginecomastia/cirurgia , Humanos , Masculino , Mamilos/cirurgia , Valores de Referência , Tórax/anatomia & histologia
15.
Trends Genet ; 17(8): 431-3, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11485800

RESUMO

Phylogenetic tree analysis shows that the accessory subunit animal mitochondrial DNA polymerase emerges as a result of horizontal transfer of the gene encoding glycyl-tRNA synthetase from a bacterium of the Thermus-Deinococcus group into the animal nuclear genome. This acquisition by a distinct eukaryotic lineage of a gene encoding a mitochondrial protein from a nonmitochondrial bacterial source underscores the contribution of different types of horizontal transfer event to the evolution of eukaryotes.


Assuntos
DNA Polimerase Dirigida por DNA/química , DNA Polimerase Dirigida por DNA/genética , Glicina-tRNA Ligase/genética , Mitocôndrias/enzimologia , Animais , Drosophila melanogaster , Evolução Molecular , Modelos Genéticos , Filogenia , Estrutura Terciária de Proteína , Xenopus laevis
16.
Nucleic Acids Res ; 29(14): 2994-3005, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11452024

RESUMO

PSI-BLAST is an iterative program to search a database for proteins with distant similarity to a query sequence. We investigated over a dozen modifications to the methods used in PSI-BLAST, with the goal of improving accuracy in finding true positive matches. To evaluate performance we used a set of 103 queries for which the true positives in yeast had been annotated by human experts, and a popular measure of retrieval accuracy (ROC) that can be normalized to take on values between 0 (worst) and 1 (best). The modifications we consider novel improve the ROC score from 0.758 +/- 0.005 to 0.895 +/- 0.003. This does not include the benefits from four modifications we included in the 'baseline' version, even though they were not implemented in PSI-BLAST version 2.0. The improvement in accuracy was confirmed on a small second test set. This test involved analyzing three protein families with curated lists of true positives from the non-redundant protein database. The modification that accounts for the majority of the improvement is the use, for each database sequence, of a position-specific scoring system tuned to that sequence's amino acid composition. The use of composition-based statistics is particularly beneficial for large-scale automated applications of PSI-BLAST.


Assuntos
Bases de Dados Factuais , Proteínas/genética , Alinhamento de Sequência/métodos , Software , Algoritmos , Aminoácidos/genética , Animais , Biologia Computacional/métodos , Biologia Computacional/estatística & dados numéricos , Humanos , Armazenamento e Recuperação da Informação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
17.
J Bacteriol ; 183(16): 4823-38, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11466286

RESUMO

The genome sequence of the solvent-producing bacterium Clostridium acetobutylicum ATCC 824 has been determined by the shotgun approach. The genome consists of a 3.94-Mb chromosome and a 192-kb megaplasmid that contains the majority of genes responsible for solvent production. Comparison of C. acetobutylicum to Bacillus subtilis reveals significant local conservation of gene order, which has not been seen in comparisons of other genomes with similar, or, in some cases closer, phylogenetic proximity. This conservation allows the prediction of many previously undetected operons in both bacteria. However, the C. acetobutylicum genome also contains a significant number of predicted operons that are shared with distantly related bacteria and archaea but not with B. subtilis. Phylogenetic analysis is compatible with the dissemination of such operons by horizontal transfer. The enzymes of the solventogenesis pathway and of the cellulosome of C. acetobutylicum comprise a new set of metabolic capacities not previously represented in the collection of complete genomes. These enzymes show a complex pattern of evolutionary affinities, emphasizing the role of lateral gene exchange in the evolution of the unique metabolic profile of the bacterium. Many of the sporulation genes identified in B. subtilis are missing in C. acetobutylicum, which suggests major differences in the sporulation process. Thus, comparative analysis reveals both significant conservation of the genome organization and pronounced differences in many systems that reflect unique adaptive strategies of the two gram-positive bacteria.


Assuntos
Clostridium/genética , Genoma Bacteriano , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sequência de Bases , Cromossomos Bacterianos/genética , Clostridium/metabolismo , Sequência Conservada , Enzimas/genética , Genes Bacterianos , Modelos Biológicos , Dados de Sequência Molecular , Óperon , Filogenia , Plasmídeos , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Solventes/metabolismo
18.
Mil Med ; 166(7): 637-40, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11469038

RESUMO

An earthquake striking a highly populated area is likely to cause a mass casualty situation for even the most advanced trauma center. If the local medical teams are injured and the hospitals are damaged beyond immediate repair, external intervention is needed. In the Turkish earthquake crisis, Israel was one of many states to deploy a field hospital to the crisis site. This was set up in Adapazari, the second most severely hit city in terms of the amount of damage. The hospital provided advanced surgical and medical facilities, including laparotomy, cesarean section, and intensive care surveillance. These facilities require sophisticated laboratory and radiology services, including hematology, chemistry, microbiology, and blood bank. The speed with which the hospital must be assembled and transported to be efficient and the basic conditions of a field hospital dictate specific considerations regarding diagnostic auxiliary equipment. Considerations in choosing this equipment, problems encountered during installation, and recommendations for the future are presented.


Assuntos
Equipamentos para Diagnóstico , Hospitais de Emergência/organização & administração , Desastres , Humanos , Israel , Turquia
19.
J Am Coll Cardiol ; 37(7): 1839-45, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11401120

RESUMO

OBJECTIVES: The goal of this study was to investigate the nature of the association between silent ischemia and postoperative myocardial infarction (PMI). BACKGROUND: Silent ischemia predicts cardiac morbidity and mortality in both ambulatory and postoperative patients. Whether silent stress-induced ischemia is merely a marker of extensive coronary artery disease or has a closer association with infarction has not been determined. METHODS: In 185 consecutive patients undergoing vascular surgery, we correlated ischemia duration, as detected on a continuous 12-lead ST-trend monitoring during the period 48 h to 72 h after surgery, with cardiac troponin-I (cTn-I) measured in the first three postoperative days and with postoperative cardiac outcome. Postoperative myocardial infarction was defined as cTn-I >3.1 ng/ml accompanied by either typical symptoms or new ischemic electrocardiogram (ECG) findings. RESULTS: During 11,132 patient-hours of monitoring, 38 patients (20.5%) had 66 transient ischemic events, all but one denoted by ST-segment depression. Twelve patients (6.5%) sustained PMI; one of those patients died. All infarctions were non-Q-wave and were detected by a rise in cTn-I during or immediately after prolonged, ST depression-type ischemia. The average duration ofischemia in patients with PMI was 226+/-164 min (range: 29 to 625), compared with 38+/-26 min (p = 0.0000) in 26 patients with ischemia but not infarction. Peak cTn-I strongly correlated with the longest, as well as cumulative, ischemia duration (r = 0.83 and r = 0.78, respectively). Ischemic ECG changes were completely reversible in all but one patient who had persistent new T wave inversion. All ischemic events culminating in PMI were preceded by an increase in heart rate (delta heart rate = 32+/-15 beats/min), and most (67%) of them began at the end of surgery and emergence from anesthesia. CONCLUSIONS: Prolonged, ST depression-type ischemia progresses to MI and is strongly associated with the majority of cardiac complications after vascular surgery.


Assuntos
Infarto do Miocárdio/etiologia , Isquemia Miocárdica/complicações , Complicações Pós-Operatórias/etiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Isquemia Miocárdica/fisiopatologia , Fatores de Tempo , Procedimentos Cirúrgicos Vasculares/efeitos adversos
20.
J Vasc Surg ; 33(5): 921-6, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11331829

RESUMO

PURPOSE: The purpose of this study was to determine the long-term functional outcome after unilateral hypogastric artery occlusion during endovascular stent graft repair of aortoiliac aneurysms. METHODS: During a 41-month period, 157 consecutive patients underwent elective endovascular stent graft repair of aortoiliac aneurysms with the Medtronic AneuRx device. Postoperative computed tomography scans were compared with preoperative scans to identify new hypogastric artery occlusions. Twenty-three (15%) patients had unilateral hypogastric occlusion, and there were no cases of bilateral occlusions. Telephone interviews about past and current levels of activity and symptoms were conducted, and pertinent medical records were reviewed. All 23 (100%) patients were available for the telephone interview. A disability score (DS) was quantitatively graded on a discrete scale ranging from 0 to 10 corresponding to "virtually bed-bound" to "greater-than-a-mile" exercise tolerance. Worsening or improvement of symptoms was expressed as a difference in DS between two time points (-, worsening/+, improving). RESULTS: Among the 23 patients, two groups were identified: 10 patients (43%) had planned and 13 patients (57%) had unplanned or inadvertent occlusions. The patients in the two groups did not differ significantly in the mean age (73.4 vs 73.7 years), sex (male:female, 9:1 vs 10:3), and duration of follow-up (15.6 vs 14.4 months). Nine (39%) of the 23 patients, five patients in the planned and four patients in the unplanned group, reported significant symptoms of hip and buttock claudication ipsilateral to their occluded hypogastric arteries. The mean decrement from baseline of these nine patients in their DS postoperatively was -3.3. The symptoms were universally noted on postoperative day 1. Although most patients improved (89%), one (11%) never got better. Among those whose symptoms improved, the mean time to improvement was 15 weeks, but with a plateau thereafter resulting in a net decrement of DS of -2.3 from baseline. Finally, when questioned whether they would undergo the procedure again, all 23 patients unanimously answered, "Yes." CONCLUSIONS: A significant number (39%) of patients who sustain hypogastric artery occlusion after endovascular aneurysm repair have symptoms. Although most patients with symptoms have some improvement, none return to their baseline level of activity. Despite this, all patients in retrospect would again choose endovascular repair over conventional open repair.


Assuntos
Aneurisma da Aorta Abdominal/cirurgia , Embolização Terapêutica , Aneurisma Ilíaco/cirurgia , Artéria Ilíaca/patologia , Complicações Pós-Operatórias , Stents , Idoso , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Nádegas/irrigação sanguínea , Embolização Terapêutica/efeitos adversos , Feminino , Quadril/irrigação sanguínea , Humanos , Aneurisma Ilíaco/diagnóstico por imagem , Artéria Ilíaca/cirurgia , Imageamento Tridimensional , Isquemia/diagnóstico , Isquemia/etiologia , Masculino , Stents/efeitos adversos , Tomografia Computadorizada por Raios X , Grau de Desobstrução Vascular
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