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1.
Rev Sci Instrum ; 92(4): 043712, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243490

RESUMO

To study matter at extreme densities and pressures, we need mega laser facilities such as the National Ignition Facility as well as creative methods to make observations during timescales of a billionth of a second. To facilitate this, we developed a platform and diagnostic to characterize a new point-projection radiography configuration using two micro-wires irradiated by a short pulse laser system that provides a large field of view with up to 3.6 ns separation between images. We used tungsten-carbide solid spheres as reference objects and inferred characteristics of the back-lighter source using a forward-fitting algorithm. The resolution of the system is inferred to be 15 µm (using 12.5 µm diameter wires). The bremsstrahlung temperature of the source is 70-300 keV, depending on laser energy and coupling efficiency. By adding the images recorded on multiple stacked image plates, the signal-to-noise of the system is nearly doubled. The imaging characterization technique described here can be adapted to most point-projection platforms where the resolution, spectral contrast, and signal-to-noise are important.

2.
Phys Rev E ; 103(3): L031201, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33862680

RESUMO

Achieving a high conversion efficiency into relativistic electrons is central to short-pulse laser application and fundamentally relies on creating interaction regions with intensities ≫10^{18}W/cm^{2}. Small focal length optics are typically employed to achieve this goal; however, this solution is impractical for large kJ-class systems that are constrained by facility geometry, debris concerns, and component costs. We fielded target-mounted compound parabolic concentrators to overcome these limitations and achieved nearly an order-of-magnitude increase to the conversion efficiency and more than tripled electron temperature compared to flat targets. Particle-in-cell simulations demonstrate that plasma confinement within the cone and formation of turbulent laser fields that develop from cone wall reflections are responsible for the improved laser-to-target coupling. These passive target components can be used to improve the coupling efficiency for all high-intensity short-pulse laser applications, particularly at large facilities with long focal length optics.

3.
Phys Rev Lett ; 125(15): 155003, 2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33095614

RESUMO

The implosion efficiency in inertial confinement fusion depends on the degree of stagnated fuel compression, density uniformity, sphericity, and minimum residual kinetic energy achieved. Compton scattering-mediated 50-200 keV x-ray radiographs of indirect-drive cryogenic implosions at the National Ignition Facility capture the dynamic evolution of the fuel as it goes through peak compression, revealing low-mode 3D nonuniformities and thicker fuel with lower peak density than simulated. By differencing two radiographs taken at different times during the same implosion, we also measure the residual kinetic energy not transferred to the hot spot and quantify its impact on the implosion performance.

4.
Phys Rev E ; 101(3-1): 031201, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32289929

RESUMO

Relativistic electron temperatures were measured from kilojoule, subrelativistic laser-plasma interactions. Experiments show an order of magnitude higher temperatures than expected from a ponderomotive scaling, where temperatures of up to 2.2 MeV were generated using an intensity of 1×10^{18}W/cm^{2}. Two-dimensional particle-in-cell simulations suggest that electrons gain superponderomotive energies by stochastic acceleration as they sample a large area of rapidly changing laser phase. We demonstrate that such high temperatures are possible from subrelativistic intensities by using lasers with long pulse durations and large spatial scales.

5.
Neuroradiol J ; 24(2): 235-41, 2011 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-24059613

RESUMO

We investigated the alteration of dopaminergic system in striata of Parkinson's disease (PD) at different stages using positron emission tomography (PET), [(11)C]2ß-carbomethoxy-3ß-(4-fluorophenyl)tropane (CFT) for dopamine transporter (DAT), and [(11)C]raclopride (RAC) for dopamine D2 receptor (D2R). We studied eight elderly healthy volunteers (Group A), 13 drug naïve patients with PD (Group B), and seven advanced PD patients with mild dyskinesia (Group D). Six patients in Group B were re-examined after antiparkinsonian therapy (Group C). Regions of interest were drawn on the cerebellar hemisphere, head of the caudate nucleus (CN), and anterior (AP) and posterior putamen (PP) in the PET images. We calculated uptake ratio index (URI), asymmetry index (AI) and presynapse-to-postsynapse ratio (PPR) to evaluate dopaminergic function. DAT was smaller in the three PD groups than the Group A. URI of RAC in the PP was significantly larger in Group B than in Groups A and C. AI of CFT in the putamen was larger in the PD groups than in normal subjects, and AI of RAC in the PP was the largest in the Group B. PPRs in the AP and PP were smaller in the three PD groups than in Group A. DAT decreased with disease progression in patients with PD. Binding of RAC was largest in the putamen of drug-naïve PD patients, but the enhanced binding could not be detected in the therapeutic patients with PD because of weak D2R affinity of RAC.

6.
Kyobu Geka ; 62(5): 417-21, 2009 May.
Artigo em Japonês | MEDLINE | ID: mdl-19425386

RESUMO

Adenocarcinoma of the thymus is a very rare malignant tumor. The standard treatment for advanced thymic carcinoma has not yet been established, and the prognosis is poor. We report a case of thymic carcinoma that involving the aortic arch and the innominate vein. A 78-year-old woman was admitted to our hospital complaining of hoarseness in April 2007. The computed tomography (CT) scan showed an anterior mediastinal tumor contiguous to the aortic arch and the innominate vein with swelling lymphnodes. Microspcopic examinations of specimens obtained by CT-guided needle biopsy revealed poorly differenciated adenocarcinoma. The carcinoembryonic antigen (CEA) level of serum elevated at 54.9 ng/ml. Thymic carcinoma was diagnosed. The chemoradiotherapy [concurrent, carboplatin (CBDCA) + paclitaxel(TXL)-->vinorelbine (NVB), 60 Gy] was performed, but the effect of the therapy was limited. The resection of the tumor with a part of aortic arch and other peripheral tissues was performed in Augast 2007. The postoperative course was uneventful and the CEA level of serum lowered to the normal. She was discharged 30 days after surgery.


Assuntos
Adenocarcinoma/patologia , Adenocarcinoma/cirurgia , Aorta Torácica/patologia , Neoplasias do Timo/patologia , Neoplasias do Timo/cirurgia , Adenocarcinoma/terapia , Idoso , Terapia Combinada , Feminino , Humanos , Invasividade Neoplásica , Neoplasias do Timo/terapia
7.
Acta Neurol Scand ; 117(4): 285-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18333957

RESUMO

(123)I-iomazenil SPECT is of value in determining an epileptogenic focus, however, transient uptake change has been rarely reported in epileptic disorders. A 78-year-old woman diagnosed as status epilepticus (SE) showed transient reduction in (123)I-iomazenil uptake within the epileptic foci on SPECT images during a couple of weeks. It suggests a seizure-related 'short-term' plasticity in the central benzodiazepine receptors and dynamic change in the regulatory mechanisms of inhibitory neurotransmitter system within the epileptic foci in patients with SE.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Plasticidade Neuronal , Receptores de GABA-A/metabolismo , Estado Epiléptico/diagnóstico por imagem , Estado Epiléptico/metabolismo , Idoso , Biomarcadores/análise , Biomarcadores/metabolismo , Encéfalo/fisiopatologia , Mapeamento Encefálico/métodos , Regulação para Baixo , Feminino , Flumazenil/análogos & derivados , Flumazenil/metabolismo , Humanos , Radioisótopos do Iodo/metabolismo , Imageamento por Ressonância Magnética , Inibição Neural , Valor Preditivo dos Testes , Estado Epiléptico/fisiopatologia , Transmissão Sináptica , Fatores de Tempo , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Ácido gama-Aminobutírico/metabolismo
8.
Kyobu Geka ; 59(2): 149-52, 2006 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-16482911

RESUMO

A 77-year-old woman with a previous history of median sternotomy and collagen disease, presented with chief complaints of resting dyspnea as a result of recurrent pericardial effusions or restrictive ventilatory impairment. She experienced significant symptom amelioration after undergoing pericardioperitoneal fenestration. We weighed the positive against the negative of various pericardial effusion drainage methods in this study. This operative procedure is not innovative, but favorable because it can be carried out conveniently and safely, enabling early rehabilitation without appreciable postoperative complications.


Assuntos
Derrame Pericárdico/cirurgia , Técnicas de Janela Pericárdica , Pericardite/cirurgia , Idoso , Doença Crônica , Feminino , Humanos , Peritônio/cirurgia , Resultado do Tratamento
9.
Acta Neurol Scand ; 112(2): 103-7, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16008536

RESUMO

OBJECTIVE: The objective of this study was to investigate the mapping of sigma1 receptors in Parkinson's disease (PD) using [11C]SA4503 and positron emission tomography (PET), and to assess whether sigma1 receptors are involved in the damaged dopaminergic system in PD patients. MATERIALS AND METHODS: We studied seven normal volunteers and six PD patients. The low density of dopamine transporters and the normal or high density of dopamine receptors were confirmed in the putamen of all patients using [11C]CFT and [11C]RAC PET. A dynamic series of PET data acquisition was performed with arterial blood sampling. We computed the binding potential (BP) of [11C]SA4503. RESULTS: In PD patients, the BP was significantly lower on the more affected than the less affected side of the anterior putamen, although there was no significant difference with respect to the BP between patients and controls. CONCLUSIONS: Release of dopamine is reduced asymmetrically in the putamen of early PD. [11C]SA4503 PET is an indicator of presynaptic dopaminergic damage in PD.


Assuntos
Dopamina/metabolismo , Vias Neurais/metabolismo , Doença de Parkinson/metabolismo , Putamen/metabolismo , Receptores sigma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Ligação Competitiva/fisiologia , Mapeamento Encefálico/métodos , Radioisótopos de Carbono , Proteínas da Membrana Plasmática de Transporte de Dopamina , Feminino , Lateralidade Funcional/fisiologia , Humanos , Masculino , Glicoproteínas de Membrana/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/metabolismo , Vias Neurais/diagnóstico por imagem , Vias Neurais/fisiopatologia , Nootrópicos/metabolismo , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/fisiopatologia , Piperazinas/metabolismo , Tomografia por Emissão de Pósitrons , Valor Preditivo dos Testes , Terminações Pré-Sinápticas/metabolismo , Putamen/diagnóstico por imagem , Putamen/fisiopatologia , Receptores Dopaminérgicos/metabolismo , Substância Negra/diagnóstico por imagem , Substância Negra/metabolismo , Substância Negra/fisiopatologia , Receptor Sigma-1
10.
J Neurol Neurosurg Psychiatry ; 76(2): 249-51, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15654042

RESUMO

AIM: To evaluate the reliability of [(123)I]meta-iodobenzylguanidine (MIBG) myocardial scintigraphy for diagnosing Parkinson's disease (PD). PATIENTS/METHODS: A series of 391 outpatients showing one or more parkinsonian-like symptoms was longitudinally followed up for accurate clinical diagnosis. MIBG scintigraphy was performed in the patients and 10 normal controls of similar age. The heart to mediastinum uptake ratio was calculated in each person, and the values were considered abnormal if they were greater than two standard deviations below the control mean. RESULTS: MIBG uptake was decreased in most patients with PD (87.7%), and was seen in all advanced cases with Hohen-Yahr stage III or more; the sensitivity and specificity of scintigraphy for detecting PD were 87.7% and 37.4%, respectively. Surprisingly, over half of the patients without PD (66.5%) also exhibited low uptake, resulting in considerable overlap in the ratios between PD and the other disorders. CONCLUSION: MIBG scintigraphy is a sensitive, but not specific, test for PD. Low MIBG uptake does not necessarily indicate PD, but is essential for diagnosing advanced PD.


Assuntos
3-Iodobenzilguanidina/farmacocinética , Coração/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Compostos Radiofarmacêuticos/farmacocinética , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Estudos Longitudinais , Masculino , Cintilografia , Sensibilidade e Especificidade
11.
Eur J Neurol ; 10(5): 593-6, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12940845

RESUMO

Most reports of micrographia associated with focal brain lesions have related this finding to damage in the left basal ganglia. Here we describe the case of a 68-year-old man presenting with reversible micrographia accompanied by hypophonia in the absence of extrapyramidal signs after cerebral infarction in the left subcortical region. At the time of the patient's admission, diffusion-weighted magnetic resonance imaging sequence showed the lesion to principally involve the corona radiata, with some involvement of the putamen. Neurologically, mild right-sided brachiofacial hemiparesis and grasp reflexes - a frontal lobe sign - were observed. As his micrographia and hypophonia improved, the patient's grasp reflexes improved in parallel. In addition, recovery of regional cerebral blood flow in the left frontal lobe was confirmed by single photon emission computed tomography (technetium-99 m HMPAO). The present case suggests the possibility that the function of frontal-subcortical circuit might also be involved in the production and improvement of micrographia and that micrographia and hypophonia may share a common pathophysiology.


Assuntos
Infarto Cerebral/patologia , Lobo Frontal/patologia , Escrita Manual , Idoso , Infarto Cerebral/complicações , Disartria/etiologia , Disartria/patologia , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino
12.
Acta Neurochir Suppl ; 86: 241-6, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14753444

RESUMO

BACKGROUND AND PURPOSE: To evaluate the feasibility of utilizing cerebral blood flow (CBF) index images, we attempted to investigate 1) whether CBF index images can reveal the resulting infracted area, 2) whether the CBF index can correlate other modality (SPECT). METHODS: DWI and DPI were obtained in 17 patients within 12 hours of stroke onset and follow up MRI. On three DPI delivered images, namely relative regional cerebral blood volume (rrCBV), uncorrected mean transit time (MTTu) and CBF index images, correlations between initial lesion volume of and follow up infarction volume of three images and rCBF images delivered with singular value decomposition (SVD) methods were assessed. Then 99mTc-ECD SPECT was taken immediately after MRI to correlate to MRI data. RESULTS: Among the three images, lesion volume of CBF index images against follow up infarct volume had the highest correlation (r = 0.995) to a linear fit and the slope was closest to 1.0 (0.91) and had identical accuracy to the regression coefficient of rCBF images. CBF index well correlated to SPECT delivered CBF. CONCLUSION: CBF index images can accurately predict final infarct volume. Evaluating CBF index images together with DWI can guide the initial assessment in the acute stage of cerebral ischemia.


Assuntos
Isquemia Encefálica/fisiopatologia , Circulação Cerebrovascular , Doença Aguda , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Infarto Cerebral/diagnóstico , Imagem de Difusão por Ressonância Magnética , Imagem Ecoplanar , Humanos , Angiografia por Ressonância Magnética , Prognóstico , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Exametazima , Tomografia Computadorizada de Emissão de Fóton Único
13.
Med Mycol ; 40(4): 435-7, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12230226

RESUMO

A strain of Fusarium solani was isolated from a dog showing many cutaneous and submucosal nodules and pyogranulomatous kidney lesions. Clinical isolates from this systemic infection were identified using microscopic examination and confirmed by molecular analysis.


Assuntos
Doenças do Cão/microbiologia , Fusarium/isolamento & purificação , Micoses/veterinária , Animais , Cães , Fusarium/genética , Fusarium/crescimento & desenvolvimento , Dados de Sequência Molecular , Micoses/microbiologia , RNA Ribossômico 28S/análise , RNA Ribossômico 28S/genética
14.
Jpn J Thorac Cardiovasc Surg ; 49(9): 581-3, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11577450

RESUMO

We experienced a rare case of ruptured left ventricular pseudoaneurysm penetrating into the left pleural cavity. A 77-year-old woman was first diagnosed with unstable angina due to sudden chest pain onset and abnormal electrocardiographic findings. In 2 days, massive left pleural effusion was recognized by chest X-ray, though subsequent computed tomographic scans did not show any aortic pathology. We observed her with left thoracentesis alone. Two days later, cardiac arrest suddenly occurred and emergency surgery was undertaken after resuscitation by percutaneous cardiopulmonary support. In surgery, a moderate amount of intrapericardial hematoma caused by rupture of a left ventricular pseudoaneurysm penetrating into the left pleural cavity was found and successfully repaired. This rare rupture of a left ventricular pseudoaneurysm penetrating into the left pleural cavity generated massive hemo-hydrothorax.


Assuntos
Falso Aneurisma/patologia , Aneurisma Cardíaco/patologia , Pleura/patologia , Idoso , Feminino , Ruptura Cardíaca , Ventrículos do Coração , Humanos
15.
Stroke ; 32(7): 1481-6, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11441189

RESUMO

BACKGROUND AND PURPOSE: Lipid and lipoprotein abnormalities have been implicated in the pathogenesis of ischemic cerebrovascular disease and atherosclerosis. Lipoprotein lipase (LPL) plays an important role in plasma lipoprotein metabolism. Several studies have recently reported the presence of a relationship between Ser447Stop mutation of LPL and coronary artery disease. Other polymorphisms (HindIII and PvuII) of the LPL gene have already been shown to correlate significantly with dyslipidemia. We investigated whether these polymorphisms are associated with increased risk of ischemic cerebrovascular disease (CVD). METHODS: We recruited 177 CVD patients (atherothrombotic infarction, n=71; cardioembolic infarction, n=30; lacunar infarction, n=76) and 177 healthy control subjects. Subjects were genotyped for the Ser447Stop mutation and for HindIII/PvuII restriction fragment length polymorphisms of the LPL gene, and the findings were investigated for associations with the clinical subtypes of CVD and with lipid levels. RESULTS: The Ser447Stop mutation correlated significantly with CVD (0.107 versus 0.158; P=0.035). For the CG+GG versus CC genotype, the odds ratio between control subjects and CVD patients with atherothrombotic infarction was 0.42 (95% CI, 0.18 to 0.99) (P=0.046). Serum HDL cholesterol and triglyceride levels did not correlate significantly with the Ser447Stop genotype. HindIII polymorphism correlated significantly with CVD (0.234 versus 0.169; P=0.031), but the frequency of PvuII polymorphism was not significantly different between groups. CONCLUSIONS: Our results suggest that the Ser447Stop mutation of the LPL gene is a novel genetic marker for low risk of atherothrombotic cerebral infarction.


Assuntos
Infarto Cerebral/genética , Embolia e Trombose Intracraniana/genética , Lipase Lipoproteica/genética , Polimorfismo de Nucleotídeo Único , Infarto Cerebral/sangue , Feminino , Frequência do Gene , Genes , Marcadores Genéticos/genética , Genótipo , Humanos , Embolia e Trombose Intracraniana/sangue , Japão , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Fatores de Risco
16.
J Neurol Neurosurg Psychiatry ; 71(1): 111-3, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11413275

RESUMO

The object was to assess alterations in CSF concentrations of monoamine metabolites during withdrawal of medication in patients with Parkinson's disease in relation to the presence or absence of episodes resembling neuroleptic malignant syndrome (NMS). This syndrome is a fatal condition developing after neuroleptic therapy, and a neuroleptic malignant-like syndrome (NMLS) may also occur after withdrawal of antiparkinsonian drugs in patients with Parkinson's disease. Previous biochemical assays showed that the CSF concentration of the dopamine metabolite homovanillic acid (HVA) is an independent prognostic factor for development of NMLS in patients with Parkinson's disease. In the present study, CSF concentrations of HVA, the noradrenaline (norepinephrine) metabolite 3-methoxy-4-hydroxyphenylethylene glycol, and the serotonin metabolite 5-hydroxyindole acetic acid were assayed using high performance liquid chromatography with electrochemical detection. The study population consisted of nine patients with Parkinson's disease with NMLS and 12 without NMLS, in whom metabolites were assayed during both withdrawal and remedicated periods. Concentrations of HVA in the CSF were significantly lower during the withdrawal period than the medicated period regardless of whether patients developed NMLS, and HVA concentrations were comparably increased after remedication in both groups. However, HVA concentrations were significantly lower in patients with NMLS than in those without NMLS during both withdrawal and medicated periods. Other metabolites showed no significant differences. The present data provide further biochemical evidence for extremely suppressed central dopaminergic activity during NMLS, which may indicate a narrow safety margin for medication withdrawal in patients with Parkinson's disease.


Assuntos
Ácido Homovanílico/líquido cefalorraquidiano , Síndrome Maligna Neuroléptica/líquido cefalorraquidiano , Doença de Parkinson/líquido cefalorraquidiano , Síndrome de Abstinência a Substâncias/líquido cefalorraquidiano , Idoso , Análise de Variância , Feminino , Humanos , Masculino
17.
Int J Syst Evol Microbiol ; 51(Pt 3): 1209-1213, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11411689

RESUMO

Ten strains which were characterized by the formation of ballistoconidia, the absence of xylose in whole-cell hydrolysates, the presence of Q-9 as the major ubiquinone isoprenologue, the inability to ferment sugars and positive diazonium blue B and urease reactions were isolated from plant samples collected in Thailand. These isolates were closely related to Bensingtonia phyllada based on the analysis of 18S rDNA sequences. On the basis of the morphological, physiological and chemotaxonomic properties, the 10 isolates were assigned to the genus Bensingtonia. DNA complementarity showed that these isolates were genetically distinct from known species of the genus Bensingtonia. The isolates are described as Bensingtonia thailandica sp. nov. The type strain is strain TY-138T (= JCM 10651T).


Assuntos
Basidiomycota/classificação , Filogenia , Folhas de Planta/microbiologia , Basidiomycota/genética , Basidiomycota/isolamento & purificação , Metabolismo dos Carboidratos , DNA Fúngico/genética , DNA Ribossômico/genética , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Tailândia , Clima Tropical
18.
Int J Syst Evol Microbiol ; 51(Pt 1): 231-235, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11211263

RESUMO

A ballistoconidia-forming yeast strain, CH 2.141T, isolated from a semi-dried leaf sample collected in Yunnan, China, was found to have Q-10(H2) as its major ubiquinone. Molecular phylogenetic analysis based on the nucleotide sequences of small subunit (18S) rDNA and the internal transcribed spacer region (including 5.8S rDNA) indicated that the strain was closely related to the two described Q-10(H2)-containing yeast species, Erythrobasidium hasegawianum and Sporobolomyces elongatus, with a closer relationship to the former. A DNA-DNA reassociation experiment showed that strain CH 2.141T represents a new yeast species, for which the name Sporobolomyces yunnanensis sp. nov. is proposed.


Assuntos
Basidiomycota/classificação , Filogenia , Ubiquinona/metabolismo , Basidiomycota/química , Basidiomycota/genética , Basidiomycota/fisiologia , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Dados de Sequência Molecular , Folhas de Planta/microbiologia , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
19.
Antonie Van Leeuwenhoek ; 80(3-4): 317-23, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11827218

RESUMO

A new species of the genus Rhodotorula was isolated from a tubeworm (Lamellibrachia sp.) collected at a depth of 1156 m in Sagami Bay, Japan. Strain SY-89 had physiological properties quite similar to R. aurantiaca. Two phylogenetic trees, one based on internal transcribed spacer (ITS) regions and 5.8S rDNA sequences and the other based on the D1/D2 region of the large subunit (26S) rDNA sequences, united strain SY-89 to the type strain of Sakaguchia dacryoides through a considerable evolutionary distance. Strain SY-89 was differentiated from S. dacryoides by the G+C content of the nuclear DNA and differences in the ability to utilize specific carbon and nitrogen compounds. The low complementarity of strain SY-89 DNA to that of the type strain of S. dacryoides confirmed that this strain was genetically unrelated to previously known species. The tubeworm isolates are described as R. lamellibrachii sp. nov. The type strain of R. lamellibrachii is strain SY-89 (= JCM 10907). R. lamellibrachii formed a cluster with Erythrobasidium hasegawianum, R. lactosa, S. dacryoides and Sporobolomyces elongatus on the ITS and 5.8S rDNA phylogenetic tree. These five species shared a signature sequence in 26S rDNA, although this relationship was not supported by phylogeny based on the D1/D2 region of 26S rDNA.


Assuntos
Poliquetos/microbiologia , Rhodotorula/classificação , Rhodotorula/isolamento & purificação , Animais , DNA Fúngico/genética , DNA Ribossômico/genética , Japão , Biologia Marinha , Filogenia , RNA Fúngico/genética , RNA Ribossômico/genética , RNA Ribossômico 5,8S/genética , Rhodotorula/genética , Especificidade da Espécie
20.
Antonie Van Leeuwenhoek ; 80(2): 101-10, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11759043

RESUMO

We isolated 99 yeast strains, including 40 red yeasts, from benthic animals and sediments collected from the deep-sea floor in various areas in the northwest Pacific Ocean. Comparing the yeast isolates from animals and sediments collected from shallow locations, the proportion of red yeasts differed considerably, comprising 81.5% and 10.6% of the isolates from animals and sediments, respectively. All of the red yeast isolates belonged to the genera Rhodotorula and Sporobolomyces. On the basis of morphological and physiological characteristics, the isolates were identified as R. aurantiaca, R. glutinis, R. minuta and R. mucilaginosa of the genus Rhodotorula, and S. salmonicolor and S. shibatanus of the genus Sporobolomyces. Only R. glutinis and R. mucilaginosa were isolated from sediments. All of the others were isolated from animal sources. Phylogenetic analyses based on internal transcribed spacer (ITS) regions and 5.8S rRNA gene sequences allowed us to establish the precise taxonomic placement of each of the isolates and thereby investigate the intraspecific relationships among the isolates. Twenty-two strains identified as members of R. glutinis, which showed a wide distribution in the deep-sea, and five isolates identified as R. minuta, which were isolated only from benthic animals, showed substantial heterogeneity within the species. The isolates phenotypically identified as Sporobolomyces species and R. mucilaginosa phylogenetically occupied the placements corresponding to these species. Some strains assigned to known species on the basis of phenotypic features should be regarded as new species as suggested by the results of molecular analysis.


Assuntos
Rhodotorula/classificação , Água do Mar/microbiologia , Ascomicetos/classificação , Basidiomycota/classificação , Geografia , Fungos Mitospóricos/classificação , Nitratos/metabolismo , Oceano Pacífico , Filogenia , Rhodotorula/isolamento & purificação
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