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1.
Chaos ; 31(1): 013134, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33754768

RESUMO

Considering in situ observations, chaos theory was taken as a basis to study the activity of anecic earthworms based on cast production from September 2016 to January 2018 in the Dong Cao watershed (Vietnam). To study this activity, the global modeling technique was used to obtain deterministic models of ordinary differential equations directly from observational time series. The obtained models show that the behavior of earthworms is chaotic; it is coupled to the dynamics of soil water content in a complex (integrative) way and can be interpreted as an habituation/sensitization process. However, this coupling is insufficient to explain the desynchronization of the cast production variations observed at different study sites. The retroaction of earthworm activity on soil is required to explain the spatiotemporal discrepancies.


Assuntos
Oligoquetos , Solo , Animais , Hidrologia
2.
Curr Microbiol ; 76(8): 962, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-29279979

RESUMO

The original version of this article unfortunately contained a mistake. The legends of Tables 2 and 3, Fig. 1 are incorrect. The corrected legends are given below.

3.
J Microsc ; 271(3): 315-324, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29926918

RESUMO

We report methods to generate three-dimensional maps of birefringence, its position and orientation in juvenile shells of the Atlantic hard clamshell (Mercenaria mercenaria). For measuring the retardance and optic axis orientation of curved shell surfaces in three dimensions, we developed enhanced acquisition and processing algorithms and combined results from conventional and light field imaging approaches to reconstruct the three-dimensional shell shape and its anisotropic optical properties. Our work represents the first successful attempt to generate such maps at a spatial resolution of about 2 µm and angular steps of about 9° in terms of the inclination angles of the optic axis. The maps of clamshell birefringence provide structural insights into the early mineralization during juvenile clamshell development.


Assuntos
Bivalves/anatomia & histologia , Imageamento Tridimensional/métodos , Microscopia de Polarização/métodos , Algoritmos , Animais , Biomineralização , Birrefringência , Bivalves/crescimento & desenvolvimento , Propriedades de Superfície
4.
Curr Microbiol ; 74(2): 203-211, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27942843

RESUMO

Extended-spectrum, ß-lactamase-producing Escherichia coli (ESBL-E) harboring the bla CTX-M-55-encoding plasmid (ESBL-E55) has been reported to be associated with urinary tract infection (UTI). The aims of this study were to clarify the prevalence of ESBL-E55 in pork meats and workers from the same wholesale market, as well as patients with UTI from a nearby hospital in Vietnam; we also investigated the plasmids encoding bla CTX-M-55. Sequencing analysis showed that 66.6% of the ESBL-E isolated from pork meats contained bla CTX-M-55, whereas the gene was present in 25.0% of workers and 12.5% of patients with UTI. Plasmid analysis showed that several sizes of plasmid encoded bla CTX-M-55 in ESBL-E55 isolated from pork meats, whereas ESBL-E55 isolated from workers and patients with UTI contained only 104-139 kbp of bla CTX-M-55-encoding plasmids. This indicates that the 104-139 kbp sizes of bla CTX-M-55-encoding plasmids were commonly disseminated in pork meats, wholesale market workers, and patients with UTI.


Assuntos
Portador Sadio/microbiologia , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/genética , Escherichia coli/enzimologia , Carne/microbiologia , Plasmídeos/análise , Infecções Urinárias/microbiologia , beta-Lactamases/genética , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/epidemiologia , Humanos , Epidemiologia Molecular , Prevalência , Análise de Sequência de DNA , Vietnã/epidemiologia
5.
Acta Anaesthesiol Scand ; 60(8): 1161-9, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27324187

RESUMO

BACKGROUND: The knowledge on the type and influence of visuospatial ability on sonography performance relevant for ultrasound-guided regional anaesthesia remains incomplete. The aim of this study was to determine whether four different factors of visuospatial ability are important in determining proficiency and procedure time of novices performing brachial plexus sonography. These factors were spatial visualisation, flexibility of closure, spatial relations and speed of closure. METHODS: Thirty-three ultrasound novices were recruited in this prospective, observational trial. Five cognitive tests, from a standardised battery that assesses all four visuospatial factors, were administered to each participant at the start of the study. Each novice then performed brachial plexus sonography on a human model at baseline and final exams, separated by a discovery learning session. Novices were examined in their sonography performance by blinded assessors who scored proficiency, technique, image quality, and time taken to perform at both baseline and final scans. RESULTS: Novices with intermediate and high visuospatial ability in spatial visualisation, spatial relations and speed of closure were significantly more proficient and efficient compared with their peers stratified into low-ability cohorts (P < 0.02). The Matrix Reasoning and the Mental Rotations Test-A were both correlated with sonography final exam scores (Spearman rank correlation ρ = 0.38 and 0.36, P = 0.03 and 0.04, respectively). CONCLUSIONS: Spatial visualisation, spatial relations and speed of closure, but not flexibility of closure, influence sonography performance. Visuospatial ability testing can identify novices who will require extra assistance in learning ultrasound relevant for regional anaesthesia. ( TRIAL REGISTRATION: Australian and New Zealand Clinical Trials Registry 12614000819628).


Assuntos
Anestesia por Condução/métodos , Plexo Braquial/diagnóstico por imagem , Ultrassonografia de Intervenção , Adulto , Feminino , Humanos , Masculino , Estudos Prospectivos
6.
Lett Appl Microbiol ; 60(6): 580-8, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25754534

RESUMO

Spore-forming bacterial strains were isolated from chicken gastrointestinal tracts to develop a heat-stable feed supplement that promotes weight gain in broilers. Seven Bacillus strains having more than 90% sporulation were screened from the isolates and identified to be closely related with Bacillus subtilis and Bacillus licheniformis. Of the seven strains, B. subtilis CH16 was selected to develop a feed supplement for broilers, because it formed 100% heat-stable spores, grew rapidly at 42°C and quickly formed a biofilm. In large-scale trials in broilers (n ≥ 1150 per group), the group fed CH16 (3 × 10(6) CFU g(-1) pellet) showed higher average daily gain (ADG = 61·16) and lower food conversion ratio (FCR = 1·696) than did the group fed B. licheniformis CH22 (ADG = 57·10 and FCR = 1·792), the group fed B. subtilis HU58 (ADG = 51·90 and FCR = 1·868), BioPlus group (ADG = 59·32 and FCR = 1·807) and the control group (ADG = 56·02 and FCR = 1·880). In conclusion, CH16 spores significantly increased ADG by 9·17% and reduced FCR by 9·79% in broilers. The result supports the use of B. subtilis CH16 of chicken intestinal origin as a feed supplement that promote weight gain in broilers. Significance and impact of the study: This study reports screening of Bacillus strains isolated from chicken gastrointestinal tracts for development of a feed supplement that promote weight gain in broilers. Of the seven Bacillus isolates with high sporulation efficiency (≥90%), Bacillus subtilis CH16 strain showed the best growth and biofilm formation at body temperature of broilers (42°C). In large-scale trials in broilers (n ≥ 1150 per group), CH16 spores induced a 9·17% increase in daily weight gain (ADG) and a 9·79% reduction in FCR while the commercial BioPlus(®) YC induced only a 5·89% increase in ADG and a 3·88% reduction in FCR.


Assuntos
Bacillus subtilis/genética , Galinhas/microbiologia , Probióticos/farmacologia , Esporos Bacterianos/metabolismo , Aumento de Peso/efeitos dos fármacos , Ração Animal/microbiologia , Animais , Bacillus subtilis/crescimento & desenvolvimento , Bacillus subtilis/isolamento & purificação , Sequência de Bases , Biofilmes/crescimento & desenvolvimento , DNA Girase/genética , DNA Bacteriano/genética , Suplementos Nutricionais/microbiologia , Trato Gastrointestinal/microbiologia , Carne , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
7.
Front Sports Act Living ; 5: 1109494, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36969962

RESUMO

The principal aim of the work presented here is to investigate and demonstrate that a forward tilted rowing blade would result in a more efficient and effective motion of the blade through the water that would result in a higher boat speed when an equal input power is provided. A 1:5 scaled rowing boat is used to determine the performance of rowing blades with different sizes and blade angles. This is used to validate the results of a previous study where the optimal blade angle of 15 ∘ with respect to the oar shaft was determined ( 1). The input power and speed of the rowing boat can be compared between original and modified oar blades. Measurements in a towing tank demonstrate that a modified rowing blade result in faster rowing by 0.4% at the same input power. Maintaining the same stroke rate, the improvement of the blade efficiency is compensated by using a 4-6% increased blade area to yield the same input power.

8.
Dalton Trans ; 50(26): 9037-9050, 2021 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-34160493

RESUMO

The development of full-visible-spectrum phosphors is essential for next-generation light-emitting devices with better light quality. Herein, we report on a novel broad-band-emitting phosphor based on single-composition Al-doped ZnO phosphors. Under the UV excitation of 325 nm, the ZnO : Al phosphor exhibits a full spectrum emission in the visible wavelength range from 400 to 800 nm with a CIE chromaticity coordinate of (0.42, 0.48), a quantum efficiency of 43%, a color rendering index (CRI) of 74, a correlated color temperature (CCT) value of 3873 K and an activation energy of 0.22 eV. A prototype of a UV-pumped warm WLED with a high CRI of 87 and a CCT of 4067 K has been achieved by using only this broad-band-emitting Al3+-doped ZnO phosphor. The obtained results indicate that the single-composition Al3+-singly doped warm white emitting phosphor is a promising candidate for UV-pump warm white light-emitting diodes.

9.
Anaesth Intensive Care ; 45(2): 202-209, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28267942

RESUMO

This prospective pilot study evaluated whether low preoperative cerebral tissue oxygen saturation is associated with unfavourable outcomes after major elective non-cardiac surgery. Eighty-one patients over 60 years of age, American Society of Anesthesiologists physical status 3 or 4, were recruited. Resting cerebral tissue oxygen saturation was recorded on room air, and after oxygen supplementation, using cerebral oximetry. The primary outcome was 30-day major adverse event of combined mortality or severe morbidity, and the secondary outcome was 30-day new disability. Eleven patients (13.6%) suffered a major adverse event, and 28 patients (34.6%) experienced new disability. Room air cerebral tissue oxygen saturation was significantly different between patients who had a major adverse event, 67% (95% confidence interval [CI] 65-70) versus unaffected, 71% (95% CI 70-72; P=0.04). No statistical difference was found between patients for new disability (range 70%-74%; P=0.73). Room air cerebral tissue oxygen saturation was significantly associated with major adverse events (odds ratio 1.36 (95% CI 1.03-1.79), P=0.03). Saturation levels ≤68% carried a positive likelihood ratio of 2.2 for death or severe morbidity, P=0.04. A definitive trial is required to confirm if cerebral oximetry can be used to stratify the cardiovascular risk of patients presenting for non-cardiac surgery.


Assuntos
Encéfalo/metabolismo , Doenças Cardiovasculares/etiologia , Oxigênio/metabolismo , Complicações Pós-Operatórias/etiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Fatores de Risco
10.
Invest Ophthalmol Vis Sci ; 41(12): 3871-7, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11053288

RESUMO

PURPOSE: To determine whether substance P (SP), a neuropeptide with proinflammatory properties, specifically interacts with human corneal epithelial cells to stimulate synthesis of the chemokines interleukin (IL)-8, monocyte chemo-attractant protein (MCP)-1, and regulated on activation normal T-cell expressed and secreted (RANTES) protein. METHODS: Primary cultures of human corneal epithelial cells were established from human corneas. Expression of the SP receptor neurokinin (NK)-1 was determined by both the reverse transcription-polymerase chain reaction (RT-PCR) and radiolabeled saturation binding experiments. Synthesis of chemokine-specific RNA in cells stimulated with SP was analyzed by RT-PCR, and quantitation of chemokine protein synthesis was achieved by enzyme-linked immunosorbent assay. RESULTS: Human corneal epithelial cells expressed NK-1 mRNA and bound SP with a K:(d) characteristic of NK-1. Exposure of cells to SP had no effect on IL-8-specific mRNA synthesis, whereas it increased the half-life of IL-8 transcripts by more than twofold, resulting in significant enhancement of IL-8 synthesis. The capacity of SP to bind to corneal epithelial cells and to induce IL-8 synthesis was abrogated in the presence of a specific NK-1 receptor antagonist. In contrast to IL-8, exposure of cells to SP did not stimulate synthesis of MCP-1 or RANTES. CONCLUSIONS: The results suggest that human corneal cells express NK-1 receptors that specifically bind SP and induce IL-8 synthesis by stabilizing the chemokine's transcripts.


Assuntos
Epitélio Corneano/efeitos dos fármacos , Interleucina-8/biossíntese , Substância P/análogos & derivados , Substância P/farmacologia , Células Cultivadas , Quimiocina CCL2/biossíntese , Quimiocina CCL2/genética , Quimiocina CCL5/biossíntese , Quimiocina CCL5/genética , Primers do DNA/química , Ensaio de Imunoadsorção Enzimática , Epitélio Corneano/citologia , Epitélio Corneano/metabolismo , Expressão Gênica/efeitos dos fármacos , Meia-Vida , Humanos , Interleucina-8/genética , Antagonistas dos Receptores de Neurocinina-1 , RNA Mensageiro/biossíntese , Receptores da Neurocinina-1/biossíntese , Receptores da Neurocinina-1/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Substância P/antagonistas & inibidores
11.
Invest Ophthalmol Vis Sci ; 37(6): 987-96, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8631642

RESUMO

PURPOSE: To determine whether human corneal epithelial cells and keratocytes produce chemokines regulated upon activation, normal T-cell expressed and secreted (RANTES) protein and monocyte chemotactic protein-1 (MCP-1) after exposure to proinflammatory cytokines interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha). METHODS: Pure cultures of human corneal epithelial cells and keratocytes were exposed to increasing concentrations of either human recombinant IL-1 alpha or TNF-alpha. At selected time intervals after exposure, culture supernatants were removed and assayed for RANTES and MCP-1 by the enzyme-linked immunosorbent assay. Total RNA was extracted from the cell cultures, and steady state mRNA levels were measured by reverse transcriptase-polymerase chain reaction. RESULTS: Exposure to keratocytes to either IL-1 alpha or TNF-alpha resulted in > 100-fold increases in RANTES protein secretion and > 150-fold increases in MCP-1 protein secretion, as well as in rapid sustained increases in intracellular levels of their corresponding mRNAs. Exposure of corneal epithelial cells to IL-1 alpha and TNF-alpha did not stimulate MCP-1 secretion nor intracellular levels of MCP-1 mRNA. Epithelial cells also failed to secrete RANTES protein even through the two inducing cytokines did stimulate increased expression of RANTES mRNA. CONCLUSIONS: These results suggest that RANTES and MCP-1 gene expression in human keratocytes differs markedly from their expression in human corneal epithelial cells and that the stroma of the cornea may be more important than the epithelium in recruitment of mononuclear leukocytes responsible for cell-mediated immunity.


Assuntos
Quimiocina CCL2/biossíntese , Quimiocina CCL5/biossíntese , Córnea/metabolismo , Interleucina-1/farmacologia , Fator de Necrose Tumoral alfa/farmacologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Sequência de Bases , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL5/genética , Quimiocinas/biossíntese , Córnea/citologia , Córnea/efeitos dos fármacos , Citocinas/farmacologia , Primers do DNA/química , Ensaio de Imunoadsorção Enzimática , Células Epiteliais , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Feminino , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Regulação da Expressão Gênica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA/isolamento & purificação , RNA Mensageiro/análise , Proteínas Recombinantes/farmacologia
12.
Clin Ther ; 10(4): 381-7, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-3079006

RESUMO

The safety of naproxen suspension was assessed in an open study in children with juvenile rheumatoid arthritis. Fifty-eight patients aged 1 to 13 (mean, 4.5 years) were studied. Based on the patient's condition, naproxen was prescribed at dosages ranging from 9 to 20 mg/kg/day. Follow-up assessments were made during regular clinic visits, as often as deemed necessary by the physician. Forty-four patients completed a minimum of six months' treatment. One patient was lost to follow up and 13 were withdrawn early: three because of unsatisfactory therapeutic response, one because of disease remission, five because of taste complaints, and four because of other side effects. The side effects were mostly gastrointestinal and were mild to moderate in severity. Investigators' subjective evaluations indicated that 84% of the patients who completed six months' treatment had good or excellent therapeutic responses at termination. The study results demonstrated that naproxen suspension is a well-tolerated anti-inflammatory agent for young children with juvenile rheumatoid arthritis.


Assuntos
Artrite Juvenil/tratamento farmacológico , Naproxeno/uso terapêutico , Adolescente , Criança , Pré-Escolar , Ensaios Clínicos como Assunto , Feminino , Humanos , Lactente , Masculino , Naproxeno/administração & dosagem , Naproxeno/efeitos adversos , Suspensões , Tolmetino/efeitos adversos
13.
Pharmacotherapy ; 21(7): 797-806, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11444576

RESUMO

PURPOSE: Coenzyme Q10 (CoQ10) has a pathophysiologic role in many disease states. The purpose of this review is to provide recommendations regarding the safety, efficacy, and dosing of CoQ10 in the management of chronic heart failure (CHF), angina, and hypertension. DATA SOURCES: Literature pertaining to the safety and efficacy of CoQ10 specifically in cardiovascular indications was reviewed. We used relevant clinical trials, articles, reviews, and letters that were selected from a literature search of the MEDLINE database (1974-2000), Micromedex Healthcare Series, and the Natural Medicines Comprehensive Database. FINDINGS: Coenzyme Q10 administered orally has favorable actions in the described cardiovascular conditions and appears to be safe and well tolerated in the adult population. Issues concerning optimum target dosages, potential interactions, monitoring parameters, and the role of CoQ10 as a monotherapeutic agent need to be investigated further. Favorable effects of CoQ10 on ejection fraction, exercise tolerance, cardiac output, and stroke volume are demonstrated in the literature; thus, the use of CoQ10 as adjuvant therapy in patients with CHF may be supported. CONCLUSIONS: Coenzyme Q10 therapy in angina and hypertension cannot be substantiated until additional clinical trials demonstrate consistent beneficial effects. However, CoQ10 may be recommended as adjuvant therapy in selected patients with CHE At this time, CoQ10 should not be recommended as monotherapy or first-line therapy in any disease state.


Assuntos
Angina Instável/tratamento farmacológico , Antioxidantes/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Hipertensão/tratamento farmacológico , Ubiquinona/análogos & derivados , Ubiquinona/fisiologia , Ubiquinona/uso terapêutico , Angina Instável/enzimologia , Animais , Antioxidantes/química , Antioxidantes/farmacocinética , Doença Crônica , Ensaios Clínicos como Assunto/estatística & dados numéricos , Coenzimas , Insuficiência Cardíaca/enzimologia , Humanos , Hipertensão/enzimologia , Ubiquinona/química , Ubiquinona/farmacocinética
14.
Toxicology ; 41(1): 61-73, 1986 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3750338

RESUMO

High-dose methotrexate (MTX) toxicity is reduced by a non-toxic dose of 5-fluorouracil (FU) when these agents are used in combination. Changes in the hematopoietic system (platelets, erythrocytes, leukocytes, hemoglobin, and hematocrit), ileal tissue, body weight, and mean survival were used as parameters to assess toxicity. For all parameters studied, there were no significant differences between the scheduling of MTX (245 mg/kg) after a priming dose of FU (25 mg/kg), simultaneous MTX and FU, FU alone, and control. However, sequential treatment with MTX followed by FU, and MTX alone resulted in: a marked decrease in the hematopoietic parameters; significant morphological changes in ileal tissue; a reduction of body weight; and increased mortality of animals. Hence, this study suggests that FU, a cytotoxic agent, may protect against MTX toxicity and improve its therapeutic index when FU administration precedes MTX or when these agents are given simultaneously.


Assuntos
Fluoruracila/farmacologia , Metotrexato/antagonistas & inibidores , Animais , Peso Corporal/efeitos dos fármacos , Contagem de Eritrócitos/efeitos dos fármacos , Hematócrito , Hemoglobinas/análise , Contagem de Leucócitos/efeitos dos fármacos , Leucopenia/induzido quimicamente , Masculino , Metotrexato/efeitos adversos , Camundongos , Contagem de Plaquetas/efeitos dos fármacos , Fatores de Tempo
15.
J Immunol ; 164(8): 4307-12, 2000 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10754330

RESUMO

Calcitonin gene-related peptide (CGRP), a neuropeptide with proinflammatory activities, is released from termini of corneal sensory neurons in response to pain stimuli. Because neutrophil infiltration of the clear corneal surface is a hallmark of corneal inflammation in the human eye, we determined whether CGRP can bind to human corneal epithelial cells (HCEC) and induce expression of the neutrophil chemotactic protein IL-8. It was found that HCEC specifically bound CGRP in a saturable manner with a Kd of 2.0 x 10-9 M. Exposure of HCEC to CGRP induced a significant increase in intracellular cAMP levels and enhanced IL-8 synthesis nearly 4-fold. The capacity of CGRP to stimulate cAMP and IL-8 synthesis was abrogated in the presence of the CGRP receptor antagonist CGRP8-37. CGRP stimulation had no effect on the half-life of IL-8 mRNA while increasing IL-8 pre-mRNA synthesis >2-fold. In contrast to IL-8, CGRP did not induce monocyte chemotactic protein-1 or RANTES synthesis, nor did the neuropeptide enhance detectable increases in steady state levels of mRNA specific for these two beta-chemokines. The results suggest that HCEC possess CGRP receptors capable of initiating a signal transduction cascade that differentially activates expression of the IL-8 gene but not the genes for monocyte chemotactic protein-1 or RANTES. The capacity of CGRP to stimulate IL-8 synthesis in HCEC suggests that sensory neurons are involved in induction of acute inflammation at the eye surface.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/fisiologia , Epitélio Corneano/imunologia , Epitélio Corneano/metabolismo , Interleucina-8/biossíntese , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Células Cultivadas , Quimiocina CCL2/biossíntese , Quimiocina CCL2/genética , Quimiocina CCL5/biossíntese , Quimiocina CCL5/genética , AMP Cíclico/biossíntese , Epitélio Corneano/citologia , Regulação da Expressão Gênica/imunologia , Humanos , Interleucina-8/genética , Neurônios Aferentes/imunologia , Neurônios Aferentes/metabolismo , RNA/biossíntese , Receptores de Peptídeo Relacionado com o Gene de Calcitonina/biossíntese
16.
Antimicrob Agents Chemother ; 43(7): 1578-83, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10390206

RESUMO

A previously unrecognized penicillin binding protein (PBP) gene, pbpF, was identified in Staphylococcus aureus. This gene encodes a protein of 691 amino acid residues with an estimated molecular mass of 78 kDa. The molecular mass is very close to that of S. aureus PBP2 (81 kDa), and the protein is tentatively named PBP2B. PBP2B has three motifs, SSVK, SSN, and KTG, that can be found in PBPs and beta-lactamases. Recombinant PBP2B (rPBP2B), which lacks a putative signal peptide at the N terminus and has a histidine tag at the C terminus, was expressed in Escherichia coli. The purified rPBP2B was shown to have penicillin binding activity. A protein band was detected from S. aureus membrane fraction by immunoblotting with anti-rPBP2B serum. Also, penicillin binding activity of the protein immunoprecipitated with anti-rPBP2B serum was detected. These results suggest the presence of PBP2B in S. aureus cell membrane that covalently binds penicillin. The internal region of pbpF and PBP2B protein were found in all 12 S. aureus strains tested by PCR and immunoblotting.


Assuntos
Proteínas de Bactérias , Proteínas de Transporte/genética , Genes Bacterianos , Hexosiltransferases , Muramilpentapeptídeo Carboxipeptidase/genética , Peptidil Transferases , Staphylococcus aureus/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas de Transporte/química , Proteínas de Transporte/imunologia , Clonagem Molecular , Dados de Sequência Molecular , Muramilpentapeptídeo Carboxipeptidase/química , Muramilpentapeptídeo Carboxipeptidase/imunologia , Penicilina G/metabolismo , Proteínas de Ligação às Penicilinas , Testes de Precipitina
17.
Virology ; 244(1): 74-8, 1998 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-9581780

RESUMO

Nanogram amounts of the proinflammatory cytokine interleukin-1alpha (IL-1alpha) were detected in uninfected cultures of human corneal epithelial cells (HCEC). Although HSV-1 replicated >10(4)-fold in these cells and caused extensive cytopathic effects, virus infection was not accompanied by significant extracellular release of IL-1alpha. Additional studies showed that release of radiolabeled cytosolic proteins from virus-infected HCEC was no greater than that released by mock-infected cells. These findings indicate that HSV-1 infection of HCEC does not result in IL-1alpha release because newly formed virus progeny can escape infected cells without disrupting cell membranes.


Assuntos
Córnea/fisiologia , Córnea/virologia , Células Epiteliais/fisiologia , Células Epiteliais/virologia , Herpesvirus Humano 1/fisiologia , Interleucina-1/metabolismo , Membrana Celular/fisiologia , Permeabilidade da Membrana Celular , Córnea/metabolismo , Células Epiteliais/metabolismo , Humanos , Líquido Intracelular , Substâncias Macromoleculares
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