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1.
J Pharm Belg ; (2): 18-25, 2016 Jun.
Artigo em Francês | MEDLINE | ID: mdl-30281227

RESUMO

Objectives Assessing the impact of professional practices on a patient's course is an interesting way to optimize health care pathway. The aim of our study is to update and evaluate the compliance to the recommendations of the Societe de Pathologie Infectieuse de Langue Francaise with regards to professional practices and the route of patients admitted to the emergency department of a French military hospital for high urinary tract infection. Patients and methods A retrospective study was carried out on patients admitted to the emergency department and treated for high urinary tract infection from January 1st, 2015 to April 30th, 2015. Clinical and administrative data, medical exams, and antibiotic prescriptions were extracted from computerized patient medical files and from emergency medical files. Results Out of 91 medical cares, 57% were compliant with the recommendations. For 60% of the patients, blood cultures were not argued and in 70% of cases, imaging wasn't justified. Antibiotic prescriptions were not compliant in 31% of cases, mostly due to long prescription durations. Two third of patients received outpatient care. All hospitalizations were argued. Conclusions Drawing up a caring protocol, regularly raising awareness to the good use of antibiotics, as well as reinforcing a cross disciplinary approach will allow optimizing health care pathways for patients coming to the emergency department with high urinary tract infection.


Assuntos
Antibacterianos/uso terapêutico , Hospitais Militares/estatística & dados numéricos , Infecções Urinárias/tratamento farmacológico , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Infecções Urinárias/microbiologia , Adulto Jovem
2.
Radiography (Lond) ; 30(1): 340-352, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38141428

RESUMO

INTRODUCTION: A positive experience in mammography is essential for increasing patient attendance and reattendance at these examinations, whether conducted for diagnostic or screening purposes. Mammograms indeed facilitate early disease detection, enhance the potential for cure, and consequently reduce breast cancer mortality. The main objective of this review was to identify and map the strategies aiming to improve the patient experience in diagnostic and screening mammography. METHODS: This scoping review was performed following the JBI methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR). Searches were performed through databases of MEDLINE, Embase.com, CINAHL, APA PsycINFO, Cochrane Central Register of Controlled Trials, Web of Science, ProQuest Dissertation and Theses, and three clinical trial registries. This review considered studies evaluating the effect of interventions, occurring within the mammography department, on the patient experience. RESULTS: The literature search yielded 8113 citations of which 60, matching the inclusion criteria, were included. The strategies were classified into eight categories. The most represented one was breast compression and positioning, followed by relaxation techniques and analgesic care, communication and information, screening equipment, examination procedures, patient-related factors, physical environment, and finally staff characteristics. The studied outcomes related to patient experience were mainly pain, anxiety, comfort, and satisfaction. Other types of outcomes were also considered in the studies such as image quality, technical parameters, or radiation dose. Most studies were conducted by radiographers, on female patients, and none mentioned the inclusion of male or transgender patients. CONCLUSION: This review outlined a diversity of strategies to improve patient experience, although technique-based interventions were predominant. Further research is warranted, notably on psychological strategies, and on men and transgender people. IMPLICATIONS FOR PRACTICE: This scoping review provides guidance to healthcare providers and services for better patient/client-centered care.


Assuntos
Neoplasias da Mama , Mamografia , Satisfação do Paciente , Feminino , Humanos , Neoplasias da Mama/diagnóstico por imagem , Detecção Precoce de Câncer/psicologia , Mamografia/psicologia , Dor
3.
Obstet Gynecol ; 67(2): 187-90, 1986 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-3945427

RESUMO

Thirty-five patients with invasive cervical carcinoma discovered in a uterus removed for benign indications were evaluated and treated from 1961 through 1983. Although formal staging was not possible, patients with presumed stage IA disease had a 100% five-year survival rate regardless of the addition of adjuvant therapy. All patients with more advanced disease received radiation therapy. Patients with presumed stage IB disease had a corrected five-year survival rate of 78%, and those with presumed stage IIB disease had a corrected five-year survival rate of 67%. No patient in this series was thought to have disease more advanced than a stage IIB equivalent. The hysterectomy alone may have been adequate therapy for patients with presumed stage IA disease. Adjuvant radiation therapy appears to be effective treatment for patients with presumed stage IB or IIB disease.


Assuntos
Adenocarcinoma/patologia , Carcinoma de Células Escamosas/patologia , Histerectomia , Neoplasias do Colo do Útero/patologia , Útero/cirurgia , Análise Atuarial , Adenocarcinoma/mortalidade , Adenocarcinoma/radioterapia , Adulto , Idoso , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/radioterapia , Feminino , Humanos , Pessoa de Meia-Idade , Invasividade Neoplásica , Recidiva Local de Neoplasia , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/radioterapia
4.
Carbohydr Res ; 243(2): 323-32, 1993 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-8348544

RESUMO

The hemicelluloses extracted from sunflower hulls by repeated alternating oxidative and alkaline treatments were purified by precipitation with Cetavlon and then ion-exchange chromatography on DEAE-trisacryl. The resulting fractions were examined by hydrolysis, methylation, GLC-MS, and NMR spectroscopy. The hemicelluloses are of the glucuronoxylan type with the following structure -->4)-beta-D-Xylp-(1-->4)-[4-O-Me-alpha-D-GlcpA-(1-->2)]-bet a-D-Xylp-(1-->. The polysaccharides differed in the amount of branching; the ratio of the main fraction 4-O-MeGlcA:Xyl was 1:8-9.


Assuntos
Helianthus/química , Polissacarídeos/química , Sementes/química , Configuração de Carboidratos , Sequência de Carboidratos , Cromatografia Gasosa-Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Metilação , Dados de Sequência Molecular , Polissacarídeos/isolamento & purificação , Espectrometria de Massas de Bombardeamento Rápido de Átomos
7.
Mol Microbiol ; 24(1): 203-16, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9140977

RESUMO

Aspergillus nidulans conidiospores contain high levels of the non-reducing disaccharide trehalose. We show that upon induction of conidiospore germination, the trehalose pool is rapidly degraded and a glycerol pool is transiently accumulated. A trehalase with an acidic pH optimum was purified from conidiospores. Characterization of the treA gene encoding this trehalase shows that it is homologous to Saccharomyces cerevisiae vacuolar acid trehalase, the product of the ATH1 gene, and to two related proteins of unknown function identified in Mycobacterium tuberculosis and Mycobacterium leprae. A. nidulans mutants that lack acid trehalase activity were constructed by gene replacement at the treA locus. Analysis of these mutants suggests that the treA gene product is localized in the conidiospore wall, is required for growth on trehalose as a carbon source, and is not involved in the mobilization of the intracellular pool of trehalose. Therefore, it is proposed that a cytoplasmic regulatory trehalase is controlling this latter process.


Assuntos
Aspergillus nidulans/enzimologia , Dissacaridases/genética , Proteínas Fúngicas/genética , Trealase/genética , Trealose/metabolismo , Sequência de Aminoácidos , Aspergillus nidulans/genética , Aspergillus nidulans/crescimento & desenvolvimento , Sequência de Bases , Carbono , DNA Fúngico , Dissacaridases/química , Dissacaridases/metabolismo , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Glicerol/metabolismo , Manitol/metabolismo , Dados de Sequência Molecular , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Solubilidade , Esporos Fúngicos/metabolismo , Trealase/química , Trealase/metabolismo , Trealose/farmacologia
8.
Health Lab Sci ; 13(4): 238-45, 1976 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-789292

RESUMO

The incidence of antibiotic-resistant fecal coliforms in raw and treated hospital and municipal wastes was investigated to determine whether such wastes may serve as reservoirs for the spread of resistant bacteria and resistance transfer factors. Multiple resistance occurred in 87.8% of isolates from hospital and 42.6% of isolates from municipal wastes. Antibiotic resistance was transferable to Escherichia coli and Salmonella cholerae-suis recipient strains from 62.3% of resistant isolates from hospital and 90.9% of resistant isolates from municipal wastes, and from 56.2% of all isolates from hospital and 45.9% of all isolates from municipal wastes. Numbers of multiply-resistant fecal coliforms decreased during passage through a sewage treatment plant, but their proportion did not change appreciably, although proportions exhibiting resistance to 3, 4, 5, 6, and 7 drugs decreased. A study of transfer in sewage indicated that transfer of resistance from donors present in sewage to pathogenic Salmonella strains can occur under appropriate conditions. The data suggest that both raw and treated wastes, and especially those from hospitals, may serve as reservoirs for the spread of antibiotic-resistant bacteria and transferable resistance in the environment.


Assuntos
Antibacterianos/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Resistência às Penicilinas , Esgotos , Ampicilina/farmacologia , Cefalotina/farmacologia , Colistina/farmacologia , Reservatórios de Doenças , Escherichia coli/efeitos dos fármacos , Hospitais , Canamicina/farmacologia , Neomicina/farmacologia , Salmonella/efeitos dos fármacos , Estreptomicina/farmacologia , Sulfatiazóis/farmacologia , Tetraciclina/farmacologia , Transformação Genética , Universidades
9.
Anal Biochem ; 199(2): 154-61, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1812780

RESUMO

The mass spectra of permethylated methyl 4,6-O-(1-carbomethoxyethylidene)-D-hexopyranoside and 1,5-anhydro-D-hexitol of glucose, galactose, and mannose and permethylated methyl 5,6-O-(1-carbomethoxyethylidene)-D-galactofuranoside and 1,4-anhydro-D-galactitol have been determined. The stability of each compound toward methanolysis and reductive cleavage is discussed. These techniques permit the identification of the acetalic linkages of pyruvic acid present in polysaccharides.


Assuntos
Bacillus/química , Klebsiella pneumoniae/química , Polissacarídeos Bacterianos/química , Piruvatos/análise , Acetilação , Sequência de Carboidratos , Galactose/química , Glucose/química , Manose/química , Espectrometria de Massas , Metanol , Metilação , Dados de Sequência Molecular , Oxirredução , Álcoois Açúcares/química
10.
Med Mycol ; 40(5): 455-64, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12462524

RESUMO

A 74 kDa beta(1-3)endoglucanase of Aspergillus fumigatus was recently isolated from a cell wall autolysate and biochemically characterized. In this study, we report the cloning and the disruption of the ENGL1 gene encoding this beta(1-3)endoglucanase. ENGL1 contains an open reading frame of 2181 bp encoding a polypeptide of 727 amino acids. Sequence analysis showed that ENGL1 is the first characterized member of a new family of beta(1-3)glucanases. Disruption of ENGL1, however, did not lead to a phenotype distinct from the parental strain, indicating that this cell wall-associated beta(1-3)endoglucanase does not play an essential role in constitutive cell growth.


Assuntos
Aspergillus fumigatus/enzimologia , Glucana Endo-1,3-beta-D-Glucosidase/genética , Sequência de Aminoácidos , Parede Celular/enzimologia , Glucana Endo-1,3-beta-D-Glucosidase/química , Glucana Endo-1,3-beta-D-Glucosidase/fisiologia , Dados de Sequência Molecular , Fenótipo
11.
J Bacteriol ; 179(10): 3154-63, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9150209

RESUMO

Two exo-beta-1,3-glucanases (herein designated exoG-I and exoG-II) were isolated from the cell wall autolysate of the filamentous fungus Aspergillus fumigatus and purified by ion-exchange, hydrophobic-interaction, and gel filtration chromatographies. Molecular masses estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography were 82 kDa for the monomeric exoG-I and 230 kDa for the dimeric exoG-II. exoG-I and exoG-II were glycosylated, and N glycans accounted, respectively, for 2 and 44 kDa. Their pH optimum is 5.0. Their optimum temperatures are 55 degrees C for exoG-I and 65 degrees C for exoG-II. By a sensitive colorimetric method and high-performance anion-exchange chromatography for product analysis, two patterns of exo-beta-1,3-glucanase activities were found. The 230-kDa exoG-II enzyme acts on p-nitrophenyl-beta-D-glucoside, beta-1,6-glucan, and beta-1,3-glucan. This activity, which retains the anomeric configuration of glucose released, presented a multichain pattern of attack of the glucan chains and a decrease in the maximum initial velocity (Vm) with the increasing size of the substrate. In contrast, the 82-kDa exoG-I, which inverts the anomeric configuration of the glucose released, hydrolyzed exclusively the beta-1,3-glucan chain with a minimal substrate size of 4 glucose residues. This enzyme presented a repetitive-attack pattern, characterized by an increase in Vm with an increase in substrate size and by a degradation of the glucan chain until it reached laminaritetraose, the limit substrate size. The 82-kDa exoG-I and 230-kDa exoG-II enzymes correspond to a beta-1,3-glucan-glucohydrolase (EC 3.2.1.58) and to a beta-D-glucoside-glucohydrolase (EC 3.2.1.21), respectively. The occurrence and functions of these two classes of exo-beta-1,3-glucanases in other fungal species are discussed.


Assuntos
Aspergillus fumigatus/enzimologia , beta-Glucosidase/metabolismo , Aspergillus fumigatus/química , Aspergillus fumigatus/metabolismo , Cátions Bivalentes , Parede Celular/química , Parede Celular/enzimologia , Parede Celular/metabolismo , Ativação Enzimática , Glucana 1,3-beta-Glucosidase , Glucose/biossíntese , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Metais , Peso Molecular , Polissacarídeos/análise , Especificidade por Substrato , Temperatura , beta-Glucosidase/biossíntese , beta-Glucosidase/isolamento & purificação
12.
Eur J Biochem ; 243(1-2): 315-21, 1997 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-9030754

RESUMO

An endo-1,3-beta-glucanase was purified from a cell wall autolysate of Aspergillus fumigatus. This beta-glucanase activity was associated with a glycosylated 74-kDa protein. Using a sensitive colorimetric assay and a high-performance anion-exchange chromatography with a pulsed electrochemical detector for product analysis, it was shown that the endoglucanase hydrolysed exclusively linear 1,3-beta-glucan chains, had an optimum pH of 7.0 and an optimum temperature of 60 degrees C. A substrate kinetic study gave a Km value of 0.3 mg/ml for soluble (laminarin and laminari-oligosaccharides) and 1.18 mg/ml for insoluble (curdlan) 1,3-beta-glucan. Laminari-oligosaccharide degradation, analysed by HPLC, showed that the endoglucanase bind to the subtrate at several positions and suggested that the active site of the enzyme recognized five glucose units linked by a 1,3-beta bond. The association of the present endo-1,3-beta-glucanase with the cell wall of A. fumigatus suggests a putative role for this enzyme during cell-wall morphogenesis.


Assuntos
Aspergillus fumigatus/enzimologia , Glucana Endo-1,3-beta-D-Glucosidase/isolamento & purificação , beta-Glucanas , Parede Celular/enzimologia , Proteínas Fúngicas/isolamento & purificação , Glucana Endo-1,3-beta-D-Glucosidase/antagonistas & inibidores , Glucanos/metabolismo , Glicosilação , Concentração de Íons de Hidrogênio , Glicoproteínas de Membrana/isolamento & purificação , Peso Molecular , Polissacarídeos/metabolismo , Especificidade por Substrato , Temperatura
13.
Biochem J ; 347 Pt 3: 741-7, 2000 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-10769178

RESUMO

A new family of glycosylphosphatidylinositol-anchored beta(1-3)glucanosyltransferases (Gelp), recently identified and characterized in the filamentous fungus Aspergillus fumigatus, showed functional similarity to the Gas/Phr/Epd protein families, which are involved in yeast morphogenesis. Sequence comparisons and hydrophobic cluster analysis (HCA) showed that all the Gas/Phr/Epd/Gel proteins belong to a new family of glycosylhydrolases, family 72. We confirmed by site-directed mutagenesis and biochemical analysis that the two conserved glutamate residues (the putative catalytic residues of this family, as determined by HCA) are involved in the active site of this family of glycosylhydrolases.


Assuntos
Aspergillus fumigatus/enzimologia , Domínio Catalítico , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Glucana Endo-1,3-beta-D-Glucosidase/química , Glucana Endo-1,3-beta-D-Glucosidase/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Western Blotting , Sequência Conservada/genética , Proteínas Fúngicas/classificação , Proteínas Fúngicas/genética , Glucana Endo-1,3-beta-D-Glucosidase/classificação , Glucana Endo-1,3-beta-D-Glucosidase/genética , Ácido Glutâmico/genética , Ácido Glutâmico/metabolismo , Glicosilfosfatidilinositóis/metabolismo , Dados de Sequência Molecular , Família Multigênica/genética , Mutação/genética , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/classificação , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Alinhamento de Sequência
14.
Eur J Biochem ; 268(10): 3126-36, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11358533

RESUMO

A new allergen from horse dander, Equ c 5 has been purified. Its biochemical and biophysical properties have been characterized and compared with those of Equ c 1, Equ c 2 and Equ c 4. Their molecular masses, determined by mass spectrometry, were 22 kDa for Equ c 1, 16 kDa for Equ c 2, 18.7 kDa for Equ c 4 and 16.7 kDa for Equ c 5. Their pI values were between 3.8 and 5.25. Equ c 2 and Equ c 5 are not glycosylated, while Equ c 4 contains a tri-antennary tri-sialylated N-linked glycan. Linkages of terminal N-acetylneuraminic acid to galactose were: alpha-(2-->6) in Equ c 4, and both alpha-(2-->3) and alpha-(2-->6) in Equ c 1. Oligosaccharide portions of Equ c 1 or Equ c 4 were barely involved in IgE-immunoreactivity. Partial N-terminal sequence of Equ c 4 shares a significant sequence homology with the rat submandibular gland protein A. No matching was found for two internal peptides of Equ c 5. Surfactant properties of horse allergens as well as other proteins were investigated. In contrast to Equ c 2 and Equ c 3, solutions of Equ c 1, Equ c 4 and Equ c 5 significantly lowered the surface tension. Relationship between a property such as this, involving oriented hydrophobic patches of a molecule and allergenicity, is addressed.


Assuntos
Alérgenos/química , Alérgenos/metabolismo , Glicoproteínas/química , Glicoproteínas/metabolismo , Tensoativos/química , Sequência de Aminoácidos , Animais , Western Blotting , Relação Dose-Resposta a Droga , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Glicosilação , Cavalos , Humanos , Concentração de Íons de Hidrogênio , Imunoglobulina E/metabolismo , Focalização Isoelétrica , Cinética , Espectrometria de Massas , Dados de Sequência Molecular , Monossacarídeos/química , Oligossacarídeos/química , Ligação Proteica , Ratos , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos , Fatores de Tempo
15.
EMBO J ; 19(17): 4473-84, 2000 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-10970841

RESUMO

Several bacterial proteins are non-covalently anchored to the cell surface via an S-layer homology (SLH) domain. Previous studies have suggested that this cell surface display mechanism involves a non-covalent interaction between the SLH domain and peptidoglycan-associated polymers. Here we report the characterization of a two-gene operon, csaAB, for cell surface anchoring, in Bacillus anthracis. Its distal open reading frame (csaB) is required for the retention of SLH-containing proteins on the cell wall. Biochemical analysis of cell wall components showed that CsaB was involved in the addition of a pyruvyl group to a peptidoglycan-associated polysaccharide fraction, and that this modification was necessary for binding of the SLH domain. The csaAB operon is present in several bacterial species that synthesize SLH-containing proteins. This observation and the presence of pyruvate in the cell wall of the corresponding bacteria suggest that the mechanism described in this study is widespread among bacteria.


Assuntos
Aldeído-Cetona Transferases/metabolismo , Bacillus anthracis/metabolismo , Proteínas de Bactérias/metabolismo , Parede Celular/enzimologia , Bacillus anthracis/enzimologia , Bacillus anthracis/genética , Sequência de Bases , Isótopos de Carbono , Primers do DNA , Mutação , Ressonância Magnética Nuclear Biomolecular , Prótons
16.
Microbiol Immunol ; 39(4): 237-42, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7651237

RESUMO

Capsular polysaccharides (CPSs) from six representative strains of Acetobacter diazotrophicus were isolated and fractionated by gel filtration and anion-exchange chromatography. Purified CPSs obtained in the non-adsorbed fraction of a DEAE-Sephadex A-25 column were qualitatively and quantitatively analyzed for sugar composition. Uronic acid and amino sugars were not detected in all purified CPSs. Basically the CPSs of A. diazotrophicus are composed of rhamnose, mannose, galactose and glucose. The presence of fucose was only observed in the CPS of strains PR2 and PAL3. Based on these results, the six strains of A. diazotrophicus could be divided into four groups according to the sugar content of their capsules: (i) fucose-containing capsules (PR2 and PAL3, localized in roots), (ii) mannose-rich capsule (PAL5, localized in root), (iii) capsules with a high ratio of hexose to rhamnose (PR4 and PR20, localized in stems) and (iv) capsules with a low ratio of hexose to rhamnose (PR14, localized in rhizosphere). For all CPSs, sodium dodecy sulfate-polyacrylamide gel electrophoresis showed diffuse bands of slow mobility in silver-stained gels. The different CPS migration patterns could not be correlated with sugar composition. The purified CPS of strain PAL3 was found to be immunogenic and immunochemically similar to the CPS of strain PR2. The serological specificity to CPS of strains PAL3 and PR2 correlated well with the presence of focuse, indicating that this deoxyhexose is immunodominant.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Acetobacter/química , Acetobacter/classificação , Cápsulas Bacterianas/química , Plantas/microbiologia , Polissacarídeos Bacterianos/isolamento & purificação , Acetobacter/isolamento & purificação , Animais , Western Blotting , Cromatografia em Gel , Cromatografia por Troca Iônica , Reações Cruzadas , Eletroforese em Gel de Poliacrilamida , Hexoses/análise , Imunodifusão , Polissacarídeos Bacterianos/análise , Polissacarídeos Bacterianos/imunologia , Coelhos
17.
C R Seances Soc Biol Fil ; 169(1): 113-7, 1975.
Artigo em Francês | MEDLINE | ID: mdl-52387

RESUMO

The constant estrus induced by neonatal androgenization in the female rat may be disrupted following a drug-induced change of the monoamine levels in the preoptic area and arcuate nucleus of the median eminence. The most precise effect is obtained with 5-HT. This is in favour of a predominant alteration of the serotonergic system which seems to be involved in the sexual differentiation of the brain.


Assuntos
Adrenérgicos/farmacologia , Estro/efeitos dos fármacos , Fenclonina/farmacologia , Neurotransmissores/farmacologia , Testosterona/farmacologia , Animais , Animais Recém-Nascidos , Dopamina/farmacologia , Implantes de Medicamento , Feminino , Hidroxidopaminas/farmacologia , Hipotálamo , Norepinefrina/farmacologia , Gravidez , Área Pré-Óptica , Ratos , Reserpina/farmacologia , Serotonina/farmacologia
18.
J Biol Chem ; 271(43): 26843-9, 1996 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-8900166

RESUMO

Cell wall transferases utilizing beta-(1-3)-glucan chains as substrates may play important roles in cell wall assembly and rearrangement, as beta-(1-3)-glucan is a major structural component of the cell wall of many fungi. A novel beta-(1-3)-glucanosyltransferase was purified to apparent homogenei ty from an autolysate of the cell wall of Aspergillus fumigatus. The enzyme had a molecular mass of 49 kDa and contained approximately 5 kDa of N-linked carbohydrate. The enzyme catalyzed an initial endo-type splitting of a beta-(1-3)-glucan molecule, followed by linkage of the newly generated reducing end to the nonreducing end of another beta-(1-3)-glucan molecule. Laminarioligosaccharides of size G10 and greater were donor substrates for the transferase. Laminarioligosaccharides of size G5 and greater formed acceptors. The enzyme was able to reuse initial transferase products as donors and acceptors in extended incubations, resulting in the formation of increasingly larger transferase products until they became insoluble. The major initial products from an incubation of the transferase with borohydride-reduced G11 (rG11) were rG6 and rG16. 1H NMR analysis of the rG16 transferase product showed it was a laminarioligosaccharide, indicating that the enzyme forms a beta-(1-3)-linkage during transfer. The enzyme may have a key function in vivo by allowing the integration of newly synthesized glucan into the wall and promoting cell wall expansion during cell growth.


Assuntos
Aspergillus fumigatus/enzimologia , Transferases/metabolismo , Parede Celular/enzimologia , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Especificidade por Substrato , Transferases/isolamento & purificação
19.
Mol Microbiol ; 32(3): 471-83, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10320571

RESUMO

A cAMP-activatable Ca2+-dependent neutral trehalase was identified in germinating conidia of Aspergillus nidulans and Neurospora crassa. Using a PCR approach, A. nidulans and N. crassa genes encoding homologues of the neutral trehalases found in several yeasts were cloned and sequenced. Disruption of the AntreB gene encoding A. nidulans neutral trehalase revealed that it is responsible for intracellular trehalose mobilization at the onset of conidial germination, and that this phenomenon is partially involved in the transient accumulation of glycerol in the germinating conidia. Although trehalose mobilization is not essential for the completion of spore germination and filamentous growth in A. nidulans, it is required to achieve wild-type germination rates under carbon limitation, suggesting that intracellular trehalose can partially contribute the energy requirements of spore germination. Furthermore, it was shown that trehalose accumulation in A. nidulans can protect germinating conidia against an otherwise lethal heat shock. Because transcription of the treB genes is not increased after a heat shock but induced upon heat shock recovery, it is proposed that, in filamentous fungi, mobilization of trehalose during the return to appropriate growth is promoted by transcriptional and post-translational regulatory mechanisms, in particular cAMP-dependent protein kinase-mediated phosphorylation.


Assuntos
Aspergillus nidulans/metabolismo , Neurospora crassa/metabolismo , Trealase/genética , Trealase/metabolismo , Trealose/metabolismo , Sequência de Aminoácidos , Aspergillus nidulans/genética , Cálcio/metabolismo , Carbono/metabolismo , AMP Cíclico/metabolismo , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Engenharia Genética , Resposta ao Choque Térmico , Dados de Sequência Molecular , Mutação , Homologia de Sequência de Aminoácidos , Esporos Fúngicos/fisiologia
20.
J Bacteriol ; 174(11): 3612-20, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1592815

RESUMO

Amylose-defective mutants were selected after UV mutagenesis of Chlamydomonas reinhardtii cells. Two recessive nuclear alleles of the ST-2 gene led to the disappearance not only of amylose but also of a fraction of the amylopectin. Granule-bound starch synthase activities were markedly reduced in strains carrying either st-2-1 or st-2-2, as is the case for amylose-deficient (waxy) endosperm mutants of higher plants. The main 76-kDa protein associated with the starch granule was either missing or greatly diminished in both mutants, while st-2-1-carrying strains displayed a novel 56-kDa major protein. Methylation and nuclear magnetic resonance analysis of wild-type algal storage polysaccharide revealed a structure identical to that of higher-plant starch, while amylose-defective mutants retained a modified amylopectin fraction. We thus propose that the waxy gene product conditions not only the synthesis of amylose from endosperm storage tissue in higher-plant amyloplasts but also that of amylose and a fraction of amylopectin in all starch-accumulating plastids. The nature of the ST-2 (waxy) gene product with respect to the granule-bound starch synthase activities is discussed.


Assuntos
Amilopectina/genética , Amilose/genética , Chlamydomonas reinhardtii/genética , Sintase do Amido/genética , Alelos , Amilopectina/metabolismo , Amilose/metabolismo , Animais , Chlamydomonas reinhardtii/metabolismo , Cloroplastos/metabolismo , Cloroplastos/ultraestrutura , Cinética , Mutação , Seleção Genética , Amido/química
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