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1.
Stud Mycol ; 90: 161-189, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29632417

RESUMO

Lophiostoma bipolare was taxonomically revised based on the morphological observations and phylogenetic analyses of molecular data from nuclear rDNA SSU-ITS-LSU, TUB, tef1, and rpb2 genes. Twenty-nine strains were morphologically similar to Lo. bipolare. A total of 174 sequences were generated from the Lo. bipolare complex. Phylogenetic analyses based on TUB sequence revealed 11 distinct species within the Lo. bipolare complex. Morphological features of the ascospores and the anatomical structure of the ascomata from both field collections as well as axenic culture, which have been reported previously as variable features at intraspecific levels, were compared to evaluate the taxonomic reliability of these features. To clarify the generic position of the 11 species, phylogenetic analyses were done on SSU-ITS-LSU-tef1-rpb2 gene sequences. The Lo. bipolare complex shared phylogenetic relationships with Pseudolophiostoma and Vaginatispora, and formed an additional five distinct clades from other members of Lophiostomataceae. According to its phylogenetic position, Lo. bipolare sensu stricto was distantly related to Lophiostoma s. str., and formed an independent clade within Lophiostomataceae. Lophiostoma bipolare s. str. could be distinguished from the other lophiostomataceous genera by the clypeus around the ostiolar neck and by the thin and uniformly thick peridium. A novel genus described as Lentistoma was established to accommodate this species, and the epitypification of Lentistoma bipolare (basionym: Massarina bipolaris) was proposed. Other lineages of the Lo. bipolare complex could not be separated on the basis of the ascospore size and sheath variations, but were distinguished based on ascomatal features, such as the existence of the clypeus, brown hyphae surrounding the peridium, and the contexture of the peridium, which were stable indicators of generic boundaries in Lophiostomataceae. Four additional new genera with five new species were recognised based on these morphological differences: Crassiclypeus (C. aquaticus), Flabellascoma (F. cycadicola and F. minimum), Leptoparies (Lep. palmarum), and Pseudopaucispora (Pseudop. brunneospora). Three new species were added to Pseudolophiostoma (Pseudol. cornisporum, Pseudol. obtusisporum, and Pseudol. tropicum) and two new species were added to Vaginatispora (V. amygdali and V. scabrispora). The re-evaluation of the validity of several previously recognised genera resulted in the introduction of two new genera with new combinations for Lophiostoma pseudoarmatisporum as Parapaucispora pseudoarmatispora and Vaginatispora fuckelii as Neovaginatispora fuckelii.

2.
Stud Mycol ; 87: 187-206, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28794574

RESUMO

The familial placement of four genera, Mycodidymella, Petrakia, Pseudodidymella, and Xenostigmina, was taxonomically revised based on morphological observations and phylogenetic analyses of nuclear rDNA SSU, LSU, tef1, and rpb2 sequences. ITS sequences were also provided as barcode markers. A total of 130 sequences were newly obtained from 28 isolates which are phylogenetically related to Melanommataceae (Pleosporales, Dothideomycetes) and its relatives. Phylogenetic analyses and morphological observation of sexual and asexual morphs led to the conclusion that Melanommataceae should be restricted to its type genus Melanomma, which is characterised by ascomata composed of a well-developed, carbonaceous peridium, and an aposphaeria-like coelomycetous asexual morph. Although Mycodidymella, Petrakia, Pseudodidymella, and Xenostigmina are phylogenetically related to Melanommataceae, these genera are characterised by epiphyllous, lenticular ascomata with well-developed basal stroma in their sexual morphs, and mycopappus-like propagules in their asexual morphs, which are clearly different from those of Melanomma. Pseudodidymellaceae is proposed to accommodate these four genera. Although Mycodidymella and Xenostigmina have been considered synonyms of Petrakia based on sexual morphology, we show that they are distinct genera. Based on morphological observations, these genera in Pseudodidymellaceae are easily distinguished by their synasexual morphs: sigmoid, multi-septate, thin-walled, hyaline conidia (Mycodidymella); globose to ovoid, dictyosporus, thick-walled, brown conidia with cellular appendages (Petrakia); and clavate with a short rostrum, dictyosporus, thick-walled, brown conidia (Xenostigmina). A synasexual morph of Pseudodidymella was not observed. Although Alpinaria was treated as member of Melanommataceae in a previous study, it has hyaline cells at the base of ascomata and pseudopycnidial, confluent conidiomata which is atypical features in Melanommataceae, and is treated as incertae sedis.

3.
Persoonia ; 39: 51-73, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29503470

RESUMO

The family Lophiotremataceae (Pleosporales, Dothideomycetes) is taxonomically revised on the basis of morphological observations and phylogenetic analyses of sequences of nuclear rDNA SSU, ITS, and LSU regions and tef1 and rpb2 genes. A total of 208 sequences were generated from species of Lophiotremataceae and its relatives. According to phylogenetic analyses, Lophiotremataceae encompasses the genus Lophiotrema and five new genera: Atrocalyx, Crassimassarina, Cryptoclypeus, Galeaticarpa, and Pseudocryptoclypeus. These genera are characterised by ascomata with or without a slit-like ostiole and pycnidial conidiomata. Three new families, Aquasubmersaceae, Cryptocoryneaceae, and Hermatomycetaceae, are proposed. Two genera previously recognised as members of Lophiotremataceae, namely, Aquasubmersa having ascomata with a papillate ostiolar neck and pycnidial conidiomata and Hermatomyces possessing sporodochial conidiomata and dimorphic (lenticular and cylindrical) conidia, are included in Aquasubmersaceae and Hermatomycetaceae, respectively. Cryptocoryneum, characterised by the presence of stromatic sporodochia, cheiroid conidia, and conidial arms developed downward from the cap cells, is placed in Cryptocoryneaceae. Two new genera, Antealophiotrema and Pseudolophiotrema, are established, but their familial placements remain unresolved. Antealophiotrema bears ascomata morphologically similar to those of Lophiotrema, but is differentiated from the latter by having ascomata with a well-developed peridium and a monodictys-like asexual morph. Pseudolophiotrema is also similar to Lophiotrema, but can be distinguished by ascomata with a thin peridium. A total of three new families, seven new genera, eight new species, and two new combinations are described and illustrated.

4.
Stud Mycol ; 82: 75-136, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26955201

RESUMO

We here taxonomically revise the suborder Massarineae (Pleosporales, Dothideomycetes, Ascomycota). Sequences of SSU and LSU nrDNA and the translation elongation factor 1-alpha gene (tef1) are newly obtained from 106 Massarineae taxa that are phylogenetically analysed along with published sequences of 131 taxa in this suborder retrieved from GenBank. We recognise 12 families and five unknown lineages in the Massarineae. Among the nine families previously known, the monophyletic status of the Dictyosporiaceae, Didymosphaeriaceae, Latoruaceae, Macrodiplodiopsidaceae, Massarinaceae, Morosphaeriaceae, and Trematosphaeriaceae was strongly supported with bootstrap support values above 96 %, while the clades of the Bambusicolaceae and the Lentitheciaceae are moderately supported. Two new families, Parabambusicolaceae and Sulcatisporaceae, are proposed. The Parabambusicolaceae is erected to accommodate Aquastroma and Parabambusicola genera nova, as well as two unnamed Monodictys species. The Parabambusicolaceae is characterised by depressed globose to hemispherical ascomata with or without surrounding stromatic tissue, and multi-septate, clavate to fusiform, hyaline ascospores. The Sulcatisporaceae is established for Magnicamarosporium and Sulcatispora genera nova and Neobambusicola. The Sulcatisporaceae is characterised by subglobose ascomata with a short ostiolar neck, trabeculate pseudoparaphyses, clavate asci, broadly fusiform ascospores, and ellipsoid to subglobose conidia with or without striate ornamentation. The genus Periconia and its relatives are segregated from the Massarinaceae and placed in a resurrected family, the Periconiaceae. We have summarised the morphological and ecological features, and clarified the accepted members of each family. Ten new genera, 22 new species, and seven new combinations are described and illustrated. The complete ITS sequences of nrDNA are also provided for all new taxa for use as barcode markers.

5.
Int J Obes (Lond) ; 38(7): 954-8, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24451186

RESUMO

BACKGROUND/OBJECTIVES: Little information is available as to the cause of increased thickening of the intima-media of the carotid artery (cIMT) in the pediatric population. Therefore, cIMT was compared in obese adolescents and normal-weight controls, and associations between cIMT and lipid and non-lipid cardiovascular risk factors were assessed. SUBJECTS/METHODS: Subjects included 61 obese non-diabetic male and female volunteers aged 12-18 years inclusive with a body mass index (BMI) >95th percentile for age and 2-h blood glucose <200 mg dl(-1) matched to 25 normal-weight control volunteers with normal glucose levels. Each subject underwent a 2-h glucose tolerance test and measurement of hemoglobin A1c, ultrasensitive C-reactive protein, fasting insulin, blood lipids, visceral, subcutaneous abdominal and hepatic fat, and cIMT. RESULTS: Maximum cIMT was 0.647±0.075 mm in the obese subjects versus 0.579±0.027 mm in normal-weight controls (P<0.001). There was no difference in maximum cIMT between male and female subjects. There were significant correlations between maximum cIMT and BMI z-score, 2-h glucose, fasting insulin, homeostasis model assessment (HOMA), total low-density lipoprotein (LDL) cholesterol, very LDL cholesterol, high-density lipoprotein (HDL) cholesterol, HDL2 cholesterol, HDL3 cholesterol, triglycerides, remnant lipoprotein cholesterol, intermediate-density lipoprotein cholesterol, lipoprotein(a), apoprotein B100, abdominal subcutaneous fat volume, visceral fat volume and hepatic phase difference. On multiple regression analysis, visceral fat was the most significant predictor of maximum cIMT. Two-hour blood glucose, HOMA and systolic blood pressure were also significant predictors of maximum cIMT. CONCLUSIONS: cIMT was increased in the obese adolescents compared with the normal-weight-matched controls. Visceral fat was a key predictor of arterial wall thickening in these subjects. The results suggest that the focus of cardiovascular disease prevention in the adolescent obese should be visceral obesity, and not blood lipids or lipid subclasses.


Assuntos
Aterosclerose/etiologia , Espessura Intima-Media Carotídea/efeitos adversos , Resistência à Insulina , Gordura Intra-Abdominal/patologia , Obesidade Infantil/complicações , Adolescente , Aterosclerose/patologia , Aterosclerose/prevenção & controle , Glicemia/metabolismo , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Criança , Feminino , Teste de Tolerância a Glucose , Hemoglobinas Glicadas/metabolismo , Humanos , Insulina/sangue , Lipídeos/sangue , Masculino , Obesidade Infantil/patologia , Obesidade Infantil/prevenção & controle , Fatores de Risco
6.
J Appl Microbiol ; 116(2): 400-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24219582

RESUMO

AIMS: A fungal endophyte, Neotyphodium uncinatum, accumulates N-formylloline, which is toxic to Hemipteran insects, in Italian ryegrass. This study aimed to clarify the dynamics of N. uncinatum and N-formylloline in Italian ryegrass, and their relationship to insect resistance. METHODS AND RESULTS: Changes in the density and localization of N. uncinatum and N-formylloline in N. uncinatum-infected Italian ryegrass were examined by real-time PCR and gas chromatography, respectively. Neotyphodium uncinatum multiplied on pseudostems at the flowering stage, and then increased on inflorescences at the ripening stage. On the other hand, N-formylloline accumulated heavily in inflorescences and leaf blades, but lightly in pseudostems at the ripening stage. In field experiments, N. uncinatum-infected Italian ryegrass suppressed the occurrence of Stenotus rubrovittatus, which fed on the inflorescences, but was not effective to Laodelphax striatellus, which do not necessarily prefer a particular plant tissue. CONCLUSION: Localization of N. uncinatum and N-formylloline were discordant in Italian ryegrass. The N. uncinatum-infected Italian ryegrass was effective to only insects that prefer to feed on particular plant tissues containing N-formylloline. SIGNIFICANCE AND IMPACT OF STUDY: Our data implies that the relationship between insect habits and the dynamics of alkaloids in plants is important for the effective use of endophyte-infected crops.


Assuntos
Alcaloides/metabolismo , Endófitos/crescimento & desenvolvimento , Hemípteros , Lolium/microbiologia , Neotyphodium/metabolismo , Animais , Produtos Agrícolas , Flores/microbiologia , Hemípteros/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Estações do Ano
7.
J Oral Rehabil ; 40(10): 744-50, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23855718

RESUMO

Disuse atrophy of swallowing-related organs due to an excessive decrease in swallowing frequency is suspected to occur in patients with poor oral intake, especially elderly people. However, swallowing frequency in daily life has not previously been examined in the elderly. This study examined swallowing frequency in elderly people and compared these findings to those in a younger population and differences in the degree of activity in daily life. (i) We compared swallowing frequency in 20 elderly people (82·0 ± 8·3 year) and 15 healthy young people (26·5 ± 3·5 year). (ii) 20 elderly people were divided into two groups according to the degree of activity in daily life: a semi-bedridden group and bedridden group; the swallowing frequency was compared between these groups. (i) The swallowing frequency in the elderly people was 2-19 times per hour and the mean was 9·4 ± 4·9, and that in the healthy young people was 16-76 times per hour and the mean was 40·7 ± 19·5. Swallowing frequency in elderly people was significantly lower than that in young healthy people (P < 0·0001). (ii) The swallowing frequency in bedridden group was 2-11 times per hour and the mean was 6·8 ± 3·3, and that in semi-bedridden group was 3-19 times per hour and the mean was 11·9 ± 5·1. Swallowing frequency in bedridden group was significantly lower than that in semi-bedridden group (P < 0·05). These results indicate that in daily life, elderly people tend to swallow less frequently than young people. In addition, swallowing frequency was lower in elderly subjects with a low degree of activity in daily life.


Assuntos
Atividades Cotidianas , Repouso em Cama/efeitos adversos , Deglutição/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Fatores de Tempo , Adulto Jovem
8.
J Oral Rehabil ; 39(6): 411-20, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22489845

RESUMO

Disuse atrophy of swallowing-related organs is suspected when decreased swallowing frequency is seen in the elderly. However, swallowing frequency has not been examined in elderly people during daily life. We developed a swallowing frequency meter containing a laryngeal microphone that does not restrict the subject's ability to perform daily activities. In this study, the utility of the meter was assessed. Experiment 1: The ability of the meter to detect swallowing was examined. The subject was instructed to swallow saliva or foods at a voluntarily pace. During these procedures, swallowing events were simultaneously recorded by the meter, self-enumeration and videofluorography. As a result, all of the swallowing events identified by the meter coincided with the swallowing events identified by self-enumeration and videofluorography. Experiment 2: Swallowing sounds display various patterns both between and within individuals. Therefore, we examined the concordance rate between the number of swallowing events counted by the meter and that counted by self-enumeration in 15 subjects over a longer period than in experiment 1. The concordance rates calculated by two examiners between the meter and self-enumeration were 96·8 ± 4·5% and 98·9 ± 3·3% at rest and 95·2 ± 4·5% and 96·1 ± 4·1% during meals, respectively. Our findings indicate that this meter is useful for measuring the frequency of swallowing during daily situations.


Assuntos
Deglutição/fisiologia , Laringe , Monitorização Ambulatorial/instrumentação , Som , Adulto , Feminino , Fluoroscopia/métodos , Humanos , MP3-Player , Masculino , Reprodutibilidade dos Testes , Autorrelato , Gravação em Vídeo , Adulto Jovem
9.
Animal ; 15(3): 100174, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33610515

RESUMO

The phytol moiety in chlorophyll molecules acts as an agonist of peroxisome proliferator-activated receptor-α in monogastric animals. The current study aimed to clarify the effects of dietary supplementation with phytol on the plasma concentrations of formate and amino acids related to one-carbon (1C) donors and its effects on lipid metabolism in sheep. Four mature sheep were fed with a mixed ration (metabolizable energy, 10.7 MJ/kg DM; CP, 150 g/kg DM) comprising barley, rice bran, soybean meal, and oat hay at 1.5 times maintenance metabolizable energy for three consecutive 14-day experimental periods. The first and third periods served as controls without phytol supplementation, while in the second period, phytol was added to the mixed ration at 12 g/kg of dietary DM per day. In each period, feces, urine, and jugular blood samples were collected. Dry matter intake in relation to metabolic BW was slightly lower (P < 0.01) in the first period than the second and third periods but did not differ between the latter two periods. Dry matter digestibility was slightly reduced (P = 0.05) by the phytol treatment. Nitrogen (N) intake and retention showed similar trends to DM intake, but urinary N was unchanged among the periods. Plasma cholesterol and phospholipid concentrations decreased during the phytol treatment period, while triglyceride concentration increased (P < 0.05). In the phytol treatment period, the plasma concentrations of serine and glycine (1C donors) increased, but the glutamate level decreased (P < 0.01). Plasma concentrations of formate and methionine increased (P < 0.01) from the first control period to the phytol supplementation period, but homocysteine and cysteine (intermediate and by-product of the methionine cycle) levels were unchanged among the treatment periods. In conclusion, dietary phytol affects lipid metabolism as well as amino acid metabolism and 1C donors in sheep. These effects may be associated with the activity of phytol as an agonist of the nuclear receptors, although this needs further investigation.


Assuntos
Ração Animal , Digestão , Aminoácidos , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais , Formiatos , Lipídeos , Fitol , Plasma , Rúmen , Ovinos
10.
J Exp Med ; 181(6): 2229-35, 1995 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-7760008

RESUMO

Superantigens, in association with class II major histocompatibility complex (MHC) molecules, activate T cells bearing particular beta chain variable domains of the T cell receptor (TCR). Unlike conventional peptide antigens, superantigens bind as intact proteins to TCR and MHC molecules outside their peptide binding sites. To characterize these interactions at the molecular level, random point mutations were generated in the gene encoding toxic shock syndrome toxin 1, a bacterial superantigen associated with toxic shock syndrome. Functionally impaired mutants were identified based on their lack of murine and human T cell stimulatory activities, and experiments analyzing binding to human histocompatibility leukocyte antigen-DR molecules differentiated residues involved in MHC from TCR binding. The results showed that the great majority of mutations are clustered in two distinct regions of the toxic shock syndrome toxin 1 molecule. The class II MHC binding site is located in the hydrophobic region of the NH2-terminal domain, and the TCR binding site is primarily in the major central groove of the COOH-terminal domain. These studies provide insight into the interactions necessary for superantigen-mediated disease in humans.


Assuntos
Toxinas Bacterianas , Enterotoxinas/metabolismo , Antígenos HLA-D/metabolismo , Antígenos de Histocompatibilidade Classe II/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Superantígenos/metabolismo , Linfócitos T/imunologia , Animais , Sequência de Bases , Sítios de Ligação , Clonagem Molecular , Primers do DNA , Enterotoxinas/biossíntese , Enterotoxinas/química , Humanos , Ativação Linfocitária , Camundongos , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação Puntual , Reação em Cadeia da Polimerase , Estrutura Secundária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Staphylococcus aureus/genética , Superantígenos/biossíntese
11.
QJM ; 113(5): 336-345, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31800058

RESUMO

BACKGROUND: Kimura's disease (KD) is known to be dominant among young Asian men, but it can also occur in middle- and advanced-aged people. The clinical characteristics of KD, especially by age, are not well known. AIM: This study was performed to investigate the effects of age on the clinical characteristics of KD. DESIGN: We conducted a case series study. METHODS: All case studies of patients diagnosed with KD were collected via a PubMed search of studies published until August 2018. The data were analyzed by age group. RESULTS: In total, 215 studies were reviewed (238 patients; mean age of 36 years). The male:female ratio was 4:1 overall, 17:1 in patients aged <20 years, 4:1 in patients aged 20-39 years and 2:1 in patients aged ≥40 years (P = 0.01). The percentage of patients with pruritus was 15.4% overall, 3.8% in patients aged <20 years, 15.5% in patients aged 20-39 years and 21.7% in patients aged ≥40 years (P = 0.02). The time to diagnosis was 5.3 years overall, 3.2 years in patients aged <20 years, 4.7 years in patients aged 20-39 years and 7.1 years in patients aged ≥40 years (P < 0.01). CONCLUSIONS: The proportion of female patients affected the incidence of pruritus, and the time to diagnosis increased as the patients' age increased. There were no significant age-related differences in region/race, complications, multiplicity, laterality, anatomical distribution, maximum size, eosinophil count, immunoglobulin E level, initial treatment, recurrence or outcomes. This may be useful information for the diagnosis of KD.


Assuntos
Doença de Kimura/diagnóstico , Doença de Kimura/fisiopatologia , Fatores Etários , Humanos , Doença de Kimura/terapia , Recidiva , Fatores Sexuais
12.
Science ; 243(4892): 792-4, 1989 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-2916125

RESUMO

A novel approach to the control of enzyme catalysis is presented in which a disulfide bond engineered into the active-site cleft of bacteriophage T4 lysozyme is capable of switching the activity on and off. Two cysteines (Thr21----Cys and Thr142----Cys) were introduced by oligonucleotide-directed mutagenesis into the active-site cleft. These cysteines spontaneously formed a disulfide bond under oxidative conditions in vitro, and the catalytic activity of the oxidized (cross-linked) T4 lysozyme was completely lost. On exposure to reducing agent, however, the disulfide bond was rapidly broken, and the reduced (non-cross-linked) lysozyme was restored to full activity. Thus an enzyme has been engineered such that redox potential can be used to control catalytic activity.


Assuntos
Dissulfetos , Muramidase/fisiologia , Engenharia de Proteínas , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Análise Mutacional de DNA , Modelos Moleculares , Proteínas Recombinantes , Relação Estrutura-Atividade , Fagos T/enzimologia
13.
Science ; 257(5072): 919-27, 1992 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-1323877

RESUMO

The x-ray structures of a murine MHC class I molecule (H-2Kb) were determined in complex with two different viral peptides, derived from the vesicular stomatitis virus nucleoprotein (52-59), VSV-8, and the Sendai virus nucleoprotein (324-332), SEV-9. The H-2Kb complexes were refined at 2.3 A for VSV-8 and 2.5 A for SEV-9. The structure of H-2Kb exhibits a high degree of similarity with human HLA class I, although the individual domains can have slightly altered dispositions. Both peptides bind in extended conformations with most of their surfaces buried in the H-2Kb binding groove. The nonamer peptide maintains the same amino- and carboxyl-terminal interactions as the octamer primarily by the insertion of a bulge in the center of an otherwise beta conformation. Most of the specific interactions are between side-chain atoms of H-2Kb and main-chain atoms of peptide. This binding scheme accounts in large part for the enormous diversity of peptide sequences that bind with high affinity to class I molecules. Small but significant conformational changes in H-2Kb are associated with peptide binding, and these synergistic movements may be an integral part of the T cell receptor recognition process.


Assuntos
Antígenos H-2/química , Proteínas Virais/química , Sequência de Aminoácidos , Animais , Sítios de Ligação , Antígenos H-2/metabolismo , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Vírus da Parainfluenza 1 Humana/metabolismo , Ligação Proteica , Conformação Proteica , Solventes , Vírus da Estomatite Vesicular Indiana/metabolismo , Proteínas Virais/metabolismo , Difração de Raios X
14.
Science ; 257(5072): 927-34, 1992 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-1323878

RESUMO

Class I major histocompatibility complex (MHC) molecules interact with self and foreign peptides of diverse amino acid sequences yet exhibit distinct allele-specific selectivity for peptide binding. The structures of the peptide-binding specificity pockets (subsites) in the groove of murine H-2Kb as well as human histocompatibility antigen class I molecules have been analyzed. Deep but highly conserved pockets at each end of the groove bind the amino and carboxyl termini of peptide through extensive hydrogen bonding and, hence, dictate the orientation of peptide binding. A deep polymorphic pocket in the middle of the groove provides the chemical and structural complementarity for one of the peptide's anchor residues, thereby playing a major role in allele-specific peptide binding. Although one or two shallow pockets in the groove may also interact with specific peptide side chains, their role in the selection of peptide is minor. Thus, usage of a limited number of both deep and shallow pockets in multiple combinations appears to allow the binding of a broad range of peptides. This binding occurs with high affinity, primarily because of extensive interactions with the peptide backbone and the conserved hydrogen bonding network at both termini of the peptide. Interactions between the anchor residue (or residues) and the corresponding allele-specific pocket provide sufficient extra binding affinity not only to enhance specificity but also to endure the presentation of the peptide at the cell surface for recognition by T cells.


Assuntos
Antígenos/metabolismo , Antígenos H-2/metabolismo , Antígenos de Histocompatibilidade Classe I/metabolismo , Peptídeos/metabolismo , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Animais , Antígenos/química , Sítios de Ligação , Antígenos H-2/química , Antígeno HLA-A2/química , Antígenos de Histocompatibilidade Classe I/química , Ligação de Hidrogênio , Camundongos , Modelos Moleculares , Dados de Sequência Molecular , Ovalbumina/química , Ovalbumina/metabolismo , Fragmentos de Peptídeos/química , Fragmentos de Peptídeos/metabolismo , Peptídeos/química , Conformação Proteica , Solventes , Vírus da Estomatite Vesicular Indiana/metabolismo , Proteínas Virais/química
15.
Ophthalmic Res ; 41(1): 53-8, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-18971589

RESUMO

PURPOSE: To determine how choroidal venous congestion alters the indocyanine green angiograms (ICGA) of monkeys. METHODS: Two vortex veins in each eye of 5 Japanese macaque monkeys were sutured and cauterized at their exit. ICGA and fluorescein angiography (FA) were performed immediately after the occlusions. The FA and ICGA findings were correlated with the histopathological changes. RESULTS: ICGA showed a delay in filling the choroidal arteries in the field of the occluded vortex veins, and the choroidal veins were filled retrogradely in a pulsatile manner. The fluorescence intensity of the larger veins was higher in the occluded area. The clearance of the indocyanine green dye was delayed by approximately 15 min. Histology showed that the choroidal veins in the occluded field were engorged with red blood cells. CONCLUSION: The ICGA findings in eyes with choroidal venous congestion are a delay in the filling of the choroidal arteries, reflux of venous blood flow, increase in fluorescence intensity of the choroidal veins, and delayed indocyanine green dye clearance.


Assuntos
Angiofluoresceinografia/métodos , Verde de Indocianina , Oclusão da Veia Retiniana/diagnóstico , Oclusão da Veia Retiniana/fisiopatologia , Animais , Modelos Animais de Doenças , Macaca fascicularis
16.
Clin Exp Immunol ; 154(2): 285-93, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18782326

RESUMO

(NZW x BXSB)F1 mice (W/BF1 mice) have been reported to be a type of autoimmune-prone mice, showing symptoms of proteinuria, anti-DNA antibodies and anti-platelet antibodies. In this paper, we report that W/BF1 mice show hyperproduction of tumour necrosis factor (TNF)-alpha, responding to lipopolysaccharide (LPS) in comparison with normal mice, resulting in induction of death. In normal mice, monocytes/macrophages (Mo/MØ) are the main producer of TNF-alpha, while both Mo/MØ and dendritic cells (DCs) produce TNF-alpha in W/BF1 mice. Because the number of DCs is higher in W/BF1 mice, the main producers of TNF-alpha in W/BF1 mice are thought to be DCs. Moreover, administration of anti-TNF-alpha antibodies rescued the W/BF1 mice from death induced by LPS, suggesting that TNF-alpha is crucial for the effect of LPS. Although there is no significant difference in the expression of Toll-like receptor-4 (TLR-4) on DCs between B6 and W/BF1 mice, nuclear factor kappa b activity of DCs from W/BF1 mice is augmented under stimulation of LPS in comparison with that of normal mice. These results suggest that the signal transduction from TLR-4 is augmented in W/BF1 mice in comparison with normal mice, resulting in the hyperproduction of TNF-alpha and reduced survival rate. The results also suggest that not only the quantity of endotoxin, but also the host conditions, the facility to translate signal from TLR, and so on, could reflect the degree of bacterial infections and prognosis.


Assuntos
Doenças Autoimunes/imunologia , Células Dendríticas/imunologia , Lipopolissacarídeos/toxicidade , Fator de Necrose Tumoral alfa/biossíntese , Animais , Relação Dose-Resposta Imunológica , Feminino , Lipopolissacarídeos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Transdução de Sinais/imunologia , Baço/imunologia , Análise de Sobrevida , Receptor 4 Toll-Like/metabolismo , Fator de Necrose Tumoral alfa/imunologia
17.
Clin Exp Immunol ; 152(3): 432-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18422733

RESUMO

Mikulicz's disease (MD) is gaining acceptance as an immunoglobulin G4 (IgG4)-related disease characterized by bilateral lacrimal and salivary gland swelling. The aetiology of MD and other IgG4-related diseases is still unclear. The present work was performed to study the clonality of infiltrating IgG4-positive plasma cells in lacrimal glands and circulating peripheral blood cells in patients with MD, and compare the clonal relationship between infiltrating and circulating IgG4 positive cells. Total cellular RNA was extracted from the lacrimal glands and peripheral blood in five MD patients. Reverse transcription polymerase chain reaction was performed with primers specific for activation-induced cytidine deaminase (AID) and for Ig VH and IgG4. Sequences of Ig VH were compared with the structure of Ig VH of the lacrimal glands and the peripheral blood cells. AID was expressed to varying degrees in lacrimal glands of all MD patients. Most IgG4-positive cells infiltrating lacrimal glands and in peripheral blood were polyclonal, although several clonally related pairs were detected. In one patient, two of the circulating IgG4 VH4-59 clones shared identical CDR3 sequences with the clones within the lacrimal glands. In conclusion, while most tissue-infiltrating and circulating IgG4-positive cells in MD are polyclonal, some clonally related IgG4 positive cells exist between lacrimal gland and peripheral blood, accounting for the clinical features of MD as an IgG4-related disease involving multiple organs.


Assuntos
Imunoglobulina G/análise , Aparelho Lacrimal/imunologia , Subpopulações de Linfócitos/imunologia , Doença de Mikulicz/imunologia , Plasmócitos/imunologia , Idoso , Sequência de Aminoácidos , Células Clonais/imunologia , Regiões Determinantes de Complementaridade/genética , Citidina Desaminase/metabolismo , Feminino , Genes de Cadeia Pesada de Imunoglobulina , Humanos , Aparelho Lacrimal/enzimologia , Masculino , Pessoa de Meia-Idade , Doença de Mikulicz/enzimologia , Doença de Mikulicz/genética , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Hipermutação Somática de Imunoglobulina
18.
Arch Oral Biol ; 53(3): 257-60, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18036508

RESUMO

OBJECTIVE: Gum arabic is a natural polysaccharide exudate from Acacia senegal and other related African species of Acacia. Gum arabic is considered to have an ability to enhance remineralization, because of its high concentration of Ca(2+). However, the caries preventive capacity of gum arabic has been scarcely investigated. We evaluated the cariostatic activities of gum arabic using histopathological methods to determine its effects on remineralization. DESIGN: Following incubation in demineralization solution, human third molars were exposed to 10 mg/ml of gum arabic, sodium fluoride at 1000 ppm (NaF), or double distilled water (DW, negative control), then subjected to demineralization-remineralization cycles. Before and after demineralization-remineralization cycles, contact microradiographs of each sample were taken and mineral distribution quantities were calculated. RESULTS: The remineralization ratio of the molars exposed to gum arabic was similar to that of those exposed to NaF, while the ratios of both were significantly greater than that of those exposed to DW. CONCLUSIONS: Gum arabic enhanced the remineralization of caries-like enamel lesions in vitro, suggesting its inhibitory effects towards dental caries.


Assuntos
Cárie Dentária/tratamento farmacológico , Goma Arábica/uso terapêutico , Incisivo/diagnóstico por imagem , Remineralização Dentária , Humanos , Técnicas In Vitro , Incisivo/efeitos dos fármacos , Microrradiografia , Fluoreto de Sódio/uso terapêutico , Água
19.
Transplant Proc ; 50(5): 1538-1543, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29705279

RESUMO

BACKGROUND: Liver transplantation from donors after cardiac death (DCD) provides a solution to the donor shortage. However, DCD liver grafts are associated with a high incidence of primary graft nonfunction. We investigated the effectiveness of subnormothermic porcine liver perfusion, before transplantation from DCD, on graft viability. METHODS: Landrace pigs (25-30 kg) were randomly allocated to 3 groups (5 per group): heart-beating (HB) graft, transplanted after a 4-hour period of cold storage (CS); DCD graft, retrieved 20 minutes after apnea-induced cardiac arrest (respiratory withdrawal) and transplanted after a 4-hour period of CS; and subnormothermic ex vivo liver perfusion (SELP) graft, retrieved in the same manner as the DCD graft but perfused with a subnormothermic oxygenated Krebs-Henseleit buffer (21-25°C, 10-15 cm H2O) for 30 minutes in a simplified dripping manner, without a machine perfusion system, after the 4-hour period of CS, and subsequently transplanted. RESULTS: Although all animals in the HB group survived for >7 days, all animals in the DCD group died within 12 hours after transplantation. In the SELP group, 2 recipients survived for >7 days and another 2 recipients were killed on day 5. The survival rate was significantly better for SELP than for DCD grafts (P = .0016). The values of tumor necrosis factor α were not significantly different between the SELP and HB groups. Preserved structure of the parenchyma was observed in the SELP group on histologic examination. CONCLUSIONS: A simplified subnormothermic perfusion before liver transplantation is expected to improve graft viability and survival.


Assuntos
Criopreservação/métodos , Transplante de Fígado/métodos , Fígado , Preservação de Órgãos/métodos , Coleta de Tecidos e Órgãos/métodos , Animais , Morte , Sobrevivência de Enxerto , Masculino , Perfusão , Suínos , Doadores de Tecidos
20.
J Clin Invest ; 105(5): 567-75, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10712428

RESUMO

Hepatoma-derived growth factor (HDGF) is the first member identified of a new family of secreted heparin-binding growth factors highly expressed in the fetal aorta. The biologic role of HDGF in vascular growth is unknown. Here, we demonstrate that HDGF mRNA is expressed in smooth muscle cells (SMCs), most prominently in proliferating SMCs, 8-24 hours after serum stimulation. Exogenous HDGF and endogenous overexpression of HDGF stimulated a significant increase in SMC number and DNA synthesis. Rat aortic SMCs transfected with a hemagglutinin-epitope-tagged rat HDGF cDNA contain HA-HDGF in their nuclei during S-phase. We also detected native HDGF in nuclei of cultured SMCs, of SMCs and endothelial cells from 19-day fetal (but not in the adult) rat aorta, of SMCs proximal to abdominal aortic constriction in adult rats, and of SMCs in the neointima formed after endothelial denudation of the rat common carotid artery. Moreover, HDGF colocalizes with the proliferating cell nuclear antigen (PCNA) in SMCs in human atherosclerotic carotid arteries, suggesting that HDGF helps regulate SMC growth during development and in response to vascular injury.


Assuntos
Substâncias de Crescimento/farmacologia , Peptídeos e Proteínas de Sinalização Intercelular , Músculo Liso/efeitos dos fármacos , Animais , Aorta/embriologia , Apoptose/efeitos dos fármacos , Arteriosclerose/metabolismo , Divisão Celular/efeitos dos fármacos , Células Cultivadas , Imunofluorescência , Regulação da Expressão Gênica no Desenvolvimento , Substâncias de Crescimento/biossíntese , Hemaglutininas/genética , Humanos , Mitógenos/farmacologia , Músculo Liso/metabolismo , Proteínas Nucleares/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , RNA Mensageiro/metabolismo , Ratos , Fase S , Transfecção , Células Tumorais Cultivadas
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