RESUMO
The etiology and treatment of temporomandibular joint (TMJ) osteoarthritis (TMJOA) remain complex and unclear. Based on clinical observations, we hypothesized that low condylar bone quality is significantly correlated with TMJOA and explored this association in a cross-sectional study with human patients. A total of 254 postmenopausal female participants were included in this study. Radiographic findings from cone beam computed tomography (CBCT) and clinical symptoms were used to classify each TMJ data sample as healthy control ( n = 124) or TMJOA ( n = 130). Condylar bone mineral density (BMD) (computed tomography Hounsfield unit [CT HU]) and bone volume fraction (BV/TV) were measured and modeled as predictors of healthy control versus TMJOA status in multilevel logistic regression analyses. Both CT HU (adjusted odds ratio [AOR] = 0.9989, interquartile odds ratio [IOR] = 0.4206) and BV/TV (AOR= 0.8096, IOR = 0.1769) were negatively associated with TMJOA ( P = 0.049, 0.011, respectively). To assess the diagnostic performance of CT HU and BV/TV for identification of TMJOA, receiver operating characteristic (ROC) curves were plotted. The estimated areas under the curve (AUC) were 0.6622 for BV/TV alone, 0.6074 for CT HU alone, and 0.7136 for CT HU and BV/TV together. The model incorporating CT HU and BV/TV together had a significantly higher AUC than the models using BV/TV alone ( P = 0.038) or HU alone ( P = 0.021). In conclusion, we found that low condylar bone quality was significantly correlated with TMJOA development and that condylar CT HU and BV/TV can be used together as a potential diagnostic tool for TMJOA. Careful clinical evaluation of the condyle coupled with appropriate radiographic interpretation would thus be critical for the early detection of TMJOA.
Assuntos
Densidade Óssea , Côndilo Mandibular/diagnóstico por imagem , Côndilo Mandibular/patologia , Osteoartrite/diagnóstico por imagem , Osteoartrite/patologia , Transtornos da Articulação Temporomandibular/diagnóstico por imagem , Transtornos da Articulação Temporomandibular/patologia , Idoso , China , Tomografia Computadorizada de Feixe Cônico , Estudos Transversais , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa , Estudos RetrospectivosRESUMO
Pulsing (15)N(18)O onto an annealed 1% Mn(16)Ox/Ce(16)O2 catalyst resulted in very fast oxygen isotope exchange and (15)N2 formation at 295 K. In the 1st (15)N(18)O pulse, due to the presence of large number of surface oxygen defects, extensive (15)N2(18)O and (15)N2 formations were observed. In subsequent pulses oxygen isotope exchange dominated as a result of highly labile oxygen in the oxide.
RESUMO
BACKGROUND AND PURPOSE: Acute occlusion of the ICA is often associated with poor outcomes and severe neurologic deficits. This study was conducted to evaluate outcome of the occluded ICA and efficacy of recanalization under protective flow arrest. MATERIALS AND METHODS: Fifty consecutive patients who underwent endovascular treatment for acute ICA occlusion were identified from the prospectively collected data base. We assessed NIHSSo, occlusion type (cardioembolism vs atherosclerosis), occlusion level (supraclinoid-terminal, petrocavernous, or bulb-cervical), recanalization degree (TICI), and efficacy of recanalization (protective flow arrest vs nonprotection) leading to better outcome. RESULTS: Successful recanalization (TICI ≥ 2) was obtained in 90% of patients and good recovery (mRS ≤ 2) in 60% of patients. Good outcome was related to National Institutes of Health Stroke Scale score on admission (P < .001), TICI (P < .007), occlusion type (P = .022), and occlusion level (P = .038). Poor initial patient status, less recanalization, cardioembolism, and supraclinoid-terminal occlusion were associated with poor prognosis. Application of protective flow arrest led to better outcome in the distal ICA segment than in the bulb-cervical segment. CONCLUSIONS: In addition to the initial patient status and successful recanalization, the occlusion level or type of the occluded ICA could affect clinical outcome. In this study, treatment benefits of protective flow arrest were accentuated in patients with ICA occlusion above the bulb-cervical segment.
Assuntos
Artéria Carótida Interna/diagnóstico por imagem , Revascularização Cerebral/métodos , Transtornos Cerebrovasculares/cirurgia , Transtornos Cerebrovasculares/terapia , Doença Aguda , Idoso , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Estenose das Carótidas/terapia , Angiografia Cerebral , Circulação Cerebrovascular , Transtornos Cerebrovasculares/diagnóstico por imagem , Terapia Combinada , Feminino , Humanos , Arteriosclerose Intracraniana/diagnóstico por imagem , Arteriosclerose Intracraniana/cirurgia , Arteriosclerose Intracraniana/terapia , Embolia Intracraniana/diagnóstico por imagem , Embolia Intracraniana/cirurgia , Embolia Intracraniana/terapia , Masculino , Pessoa de Meia-Idade , Trombectomia , Resultado do TratamentoRESUMO
Polyphenolic compounds present in green tea, particularly catechins, are known to have strong anti-influenza activity. The goal of this study was to determine whether green tea by-products could function as an alternative to common antivirals in animals compared to original green tea. Inhibition of viral cytopathic effects ascertained by neutral red dye uptake was examined with 50% effective (virus-inhibitory) concentrations (EC50)determined. Against the H1N1 virus A/NWS/33, we found the anti-influenza activity of green tea by-products (EC50 = 6.36 µg/mL) to be equivalent to that of original green tea (EC50= 6.72 µg/mL). The anti-influenza activity of green tea by-products was further examined in mouse and chicken influenza infection models. In mice, oral administration of green tea by-products reduced viral titers in the lungs in the early phase of infection, but they could not protect these animals from disease and death. In contrast, therapeutic administration of green tea by-products via feed or water supplement resulted in a dose-dependent significant antiviral effect in chickens, with a dose of 10 g/kg of feed being the most effective (P < 0.001). We also demonstrated that unidentified hexane-soluble fractions of green tea by-products possessed strong anti-influenza activity, in addition to ethyl acetate-soluble fractions, including catechins. This study revealed green tea by-product extracts to be a promising novel antiviral resource for animals.
Assuntos
Antivirais/administração & dosagem , Camellia sinensis/química , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H9N2/efeitos dos fármacos , Infecções por Orthomyxoviridae/veterinária , Extratos Vegetais/administração & dosagem , Administração Intranasal/veterinária , Administração Oral , Animais , Antivirais/química , Antivirais/farmacologia , Catequina/análogos & derivados , Catequina/química , Catequina/farmacologia , Linhagem Celular , Galinhas , Testes de Inibição da Hemaglutinação/veterinária , Camundongos , Camundongos Endogâmicos BALB C , Neuraminidase/antagonistas & inibidores , Vermelho Neutro/química , Infecções por Orthomyxoviridae/tratamento farmacológico , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária , Organismos Livres de Patógenos EspecíficosRESUMO
In this paper, micro gas sensor was fabricated using indium oxide nanowire for effective gas detection and monitoring system. Indium oxide nanowire was grown using thermal CVD, and their structural properties were examined by the SEM, XRD and TEM. The electric properties for microdropped indium oxide nanowire device were measured, and gas response characteristics were examined for CO gas. Sensors showed high sensitivity and stability for CO gas. And with below 20 mw power consumption, 5 ppm CO could be detected.
Assuntos
Monóxido de Carbono/análise , Condutometria/instrumentação , Eletroquímica/instrumentação , Gases/análise , Índio/química , Nanotubos/química , Transdutores , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Nanotubos/ultraestrutura , Sensibilidade e EspecificidadeRESUMO
Vertically well-aligned high quality ZnO nanowires were grown on GaN epilayer on c-plane sapphire via a vapor-liquid-solid (VLS) process by introducing an Au thin film (3 nm) as a catalyst. ZnO single nanowire device was ingenuously fabricated by combining conventional optical lithography and high resolution electron beam lithography and its current-voltage characteristics were measured with doing the post process to acquire reproducible performance as a chemical gas sensor. And its temperature dependent current-voltage characteristics were measured to investigate temperature dependant electrical transport. The ZnO nanowire device showed slightly non-ohmic current-voltage characteristics which may be due to back-to-back configuration of the diodes with the insulating contact barriers and showed an relatively small activation energy of 0.2 eV. To test our device as a chemical sensor, the NO2 gas response was reported at the elevated temperature.
Assuntos
Técnicas Biossensoriais/instrumentação , Nanotecnologia/instrumentação , Nanofios/química , Óxido de Zinco/química , Cristalização , Eletricidade , Eletroquímica/métodos , Microscopia Eletrônica de Varredura , Modelos Químicos , Nanotubos/química , Óptica e Fotônica , Semicondutores , Temperatura , Difração de Raios X , Zinco/químicaRESUMO
BACKGROUND: The transplantation of isolated islets is believed to be an attractive approach for cure of diabetes mellitus. Heat-shock protein (HSP70), which plays a vital role in cellular protection, has been detected in various tissues subjected to stress. Glutamine (GLN) is an important cellular fuel and an essential precursor for the antioxidant glutathione (GSH). It is believed to enhance cellular survival against a variety of stressful stimuli through HSP70. Thus, we performed this study to examine the hypothesis that preoperative GLN administration induces HSP70 and GSH expression before islet transplantation attenuating ischemic damage to rat islets. METHODS: Adult male Sprague-Dawley (SD) rats were randomly divided into two groups according to the administration of GLN after islet isolation. Group A served as the controls, receiving no GLN. Group B islet cells were cultured with L-GLN (10 mmol/L) supplementation for 24 hours. The GSH levels were measured in islet cells. Both HSP70 and proteins related to apoptosis were analyzed in islet cells by Western blots. Isolated rat islets were cultured with interleukin (IL)-1beta. Nitrite production was measured using the Griess reagent. RESULTS: The GSH levels were significantly elevated in the glutamine-treated group. HSP70 expression in islets treated with GLN was markedly stronger compared with the control group. The basal Bcl-2 expression was markedly increased by GLN treatment. The GLN-treated group showed attenuated IL-1beta-induced injury in association with NO production. CONCLUSION: These results suggested that preoperative GLN administration induced HSP70 and GSH expressions before islet transplantation, thus attenuating IL-1beta-induced injury in association with NO production and apoptosis, which might be potential tool to mitigate the ischemic damage to islet cells and the early inflammation at the site of implantation through a self-protective mechanism.
Assuntos
Glutamina/farmacologia , Glutationa/biossíntese , Proteínas de Choque Térmico HSP70/biossíntese , Isquemia/prevenção & controle , Ilhotas Pancreáticas/fisiologia , Animais , Técnicas de Cultura de Células/métodos , Sobrevivência Celular/efeitos dos fármacos , Glucose/farmacologia , Temperatura Alta , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/patologia , Transplante das Ilhotas Pancreáticas/fisiologia , Masculino , Ratos , Ratos Sprague-DawleyRESUMO
Dengue fever is a significant health problem for international travelers to all endemic area. Dengue fever is characterized by a sudden onset of fever, headache, rash, myalgia, and joint pain. Infection with the dengue virus is detrimental to a immunosuppressed renal transplant patients. Herein we report a 29-year-old woman living-related renal transplant recipient returning from Southeast Asia with dengue fever presenting as acute colitis. The patient traveled to Southeast Asia for 1 week. She developed watery diarrhea in the second week after the onset of symptoms of dengue fever. Laboratory findings were leukopenia, thrombocytopenia, and elevated serum transaminase levels. Sigmoidoscopic features showed nonspecific acute colitis. She improved after 10 days of hospitalization with intensive supportive care and continuous tacrolimus monotherapy. Altered clinical symptoms are manifested in immunologically naïve adults. Manifestation of unusual symptoms does not exclude dengue virus infection in renal transplant recipients.
Assuntos
Colite/etiologia , Dengue/complicações , Transplante de Rim/efeitos adversos , Doença Aguda , Adulto , Diarreia/etiologia , Feminino , Humanos , Falência Renal Crônica/cirurgia , Complicações Pós-Operatórias/virologia , ViagemRESUMO
Malignancy represents a leading cause of morbidity and mortality in patients with a long-term surviving graft. Carcinoid tumor is a common primary endocrine tumor in the general population that is rare in transplant recipients. Our present report focused on a 48-year-old man who received immunosuppressive therapy based on cyclosporine and steroids. Twelve years after renal transplantation, he suffered watery diarrhea and abdominal discomfort. Colonoscopy showed a hard, sessile mass at 5 cm from the anal verge; endoscopic ultrasound showed a 13-mm homogenous hypoechoic mass. Upon endoscopic biopsy, the histological examination revealed a carcinoid tumor. Immunosuppresion was reduced and we performed endoscopic mucosal resection of the rectum. His clinical course has been good with no demonstrated recurrence.
Assuntos
Tumor Carcinoide/diagnóstico , Transplante de Rim/efeitos adversos , Neoplasias Retais/diagnóstico , Tumor Carcinoide/diagnóstico por imagem , Tumor Carcinoide/patologia , Tumor Carcinoide/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Resultado do Tratamento , UltrassonografiaRESUMO
Viruses are the most common cause of opportunistic infections, important complications of transplantation. Mumps infection in renal transplant recipients is uncommon. This report focused on a 23-year-old woman who received immunosuppressive therapy based on tacrolimus, prednisolone, and mycophenolate mofetil for renal transplantation. Sixteen months after transplantation, she was admitted with pain and swelling in both infra-auricular areas. Laboratory findings demonstrated positive mumps IgM and IgG antibodies and an increased serum amylase level. Computed tomography revealed both parotid glands to be diffusely enlarged. After the diagnosis of mumps parotitis, the patient's immunosuppression was reduced and the clinical course was satisfactory.
Assuntos
Imunossupressores/uso terapêutico , Transplante de Rim/efeitos adversos , Caxumba/diagnóstico , Complicações Pós-Operatórias/virologia , Adulto , Quimioterapia Combinada , Feminino , Humanos , Terapia de Imunossupressão/efeitos adversos , Imunossupressores/efeitos adversos , Falência Renal Crônica/cirurgia , Caxumba/imunologiaRESUMO
A 51-year-old man was admitted with microscopic hematuria at 10 years after living donor renal transplantation. In order to distinguish between acute tubular necrosis and acute rejection, a graft biopsy was performed under ultrasound guidance at 1 month posttransplantation. Doppler sonography revealed 3 pulsatile cystic masses and an arteriovenous fistula (AVF) in the lower kidney pole. Selective transplant renal angiography revealed 3 pseudoaneurysms with an AVF supplied by a lobular artery in the lower pole. The diagnosis was AVF with pseudoaneurysm, which developed secondary to percutaneous renal allograft biopsy. Interventional treatment was performed because of the high risk for pseudoaneurysm rupture. The AVF and pseudoaneurysms were treated successfully by percutaneous transluminal embolization; renal function remained stable after embolization.
Assuntos
Falso Aneurisma/diagnóstico por imagem , Fístula Arteriovenosa/diagnóstico por imagem , Embolização Terapêutica , Transplante de Rim/patologia , Complicações Pós-Operatórias/diagnóstico por imagem , Falso Aneurisma/terapia , Fístula Arteriovenosa/terapia , Biópsia , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/terapia , Fatores de Tempo , Transplante Homólogo/patologia , Ultrassonografia DopplerRESUMO
INTRODUCTION: Cytomegalovirus (CMV) and polyoma virus BK (BKV) may both establish latency following primary infection. Frequent reactivation of these viruses can occur in the kidney transplant recipients. BKV may induce CMV gene expression by stimulating cellular regulator proteins or by its own gene regulator proteins. A high rate of concurrent CMV infections has been noted in kidney transplant recipients with polyoma virus-associated nephropathy (PVAN). METHODS: PVAN was identified in 10 of 191 patients who received kidney transplants between October 1998 and September 2003. PVAN was confirmed by allograft kidney biopsy. Four of the 10 patients were complicated by concurrent CMV infection. RESULTS: Two patients had only serological evidence of CMV infection and one patient had CMV gastritis. These three patients were treated with intravenous ganciclovir with good results. Disseminated ganciclovir-resistant CMV disease was demonstrated in the remaining patient. This 34-year-old kidney transplant recipient with PVAN died of multiorgan failure despite antiviral therapy with both ganciclovir and foscarnet. CONCLUSION: PVAN with concurrent CMV infection in kidney transplant recipients showed variable clinical courses including mortality. Further studies are needed to elucidate the influence of PVAN on the pathogenesis of CMV infection.
Assuntos
Infecções por Citomegalovirus/epidemiologia , Transplante de Rim/patologia , Infecções por Polyomavirus/epidemiologia , Complicações Pós-Operatórias/virologia , Adulto , Citomegalovirus/genética , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/complicações , Feminino , Regulação Viral da Expressão Gênica , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Polyomavirus/genética , Polyomavirus/isolamento & purificação , Infecções por Polyomavirus/complicações , Estudos Retrospectivos , Doadores de Tecidos/estatística & dados numéricosRESUMO
A key question for the BaO-based NOx storage/reduction catalyst system is the morphological evolution of the catalyst particles during the uptake and release of NOx. Notably, because the formed product during NOx uptake, Ba(NO3)2, requires a lattice expansion from BaO, one can anticipate that significant structural rearrangements are possible during the storage/reduction processes. Associated with the small crystallite size of high-surface area gamma-Al2O3, it is difficult to extract structural and morphological features of Ba(NO3)2 supported on gamma-Al2O3 by any direct imaging method, including transmission electron microscopy. In this work, by choosing a model system of Ba(NO3)2 particles supported on single-crystal alpha-Al2O3, we have investigated the structural and morphological features of Ba(NO3)2 as well as the formation of BaO from Ba(NO3)2 during the thermal release of NOx, using ex-situ and in-situ TEM imaging, electron diffraction, energy dispersive spectroscopy (EDS), and Wulff shape construction. We find that Ba(NO3)2 supported on alpha-Al2O3 possesses a platelet morphology, with the interface and facets being invariably the eight [111] planes. Formation of the platelet structure leads to an enlarged interface area between Ba(NO3)2 and alpha-Al2O3, indicating that the interfacial energy is lower than the Ba(NO3)2 surface free energy. In fact, Wulff shape constructions indicate that the interfacial energy is approximately 1/4 of the [111] surface free energy of Ba(NO3)2. The orientation relationship between Ba(NO3)2 and the alpha-Al2O3 is alpha-Al2O3[0001]//Ba(NO3)2[111] and alpha-Al2O3(1-210)//Ba(NO3)2(110). Thus, the results clearly demonstrate dramatic morphology changes in these materials during NOx release processes. Such changes are expected to have significant consequences for the operation of the practical NOx storage/reduction catalyst technology.
RESUMO
Although protein C and/or S deficiency has frequently been associated with venous thromboembolic events, instances of arterial thromboses have been reported. However, the exact incidence of protein C and/or S deficiency in patients with peripheral arterial insufficiency has not been established. Furthermore, given the lack of adequate studies to define the natural history and angiographic findings of these patients, the treatment has not been well delineated. Therefore, we conducted a prospective study to investigate the prevalence, characteristic angiographic findings and optimal treatments in patients with peripheral arterial insufficiency associated with protein C and/or S deficiency. Between September 2000 and August 2004, 133 patients who presented with peripheral arterial insufficiency underwent hypercoagulability tests before the initiation of any treatments. Of these, 11 patients (8.3%) with protein C and/or S deficiency were included in this study. There were nine males and two females. The ages ranged from 38 years to 72 years (mean 57 years). All patients showed characteristic angiographic findings: long segment thrombotic occlusion of a main peripheral artery without evidence of atherosclerosis or with mild atherosclerotic changes in the aorta and other major arterial trees. Surgical or endovascular procedures were performed in nine patients: bypass graft in four, thrombectomy in four and catheter-directed thrombolysis in one. Conservative treatment with full anticoagulation was performed in two patients. All patients received pre- and post-operative anticoagulation. Except for one amputated case, clinical and vascular laboratory improvements were achieved in 10 patients. Mean follow-up period was 21 months (range 4-45 months). However, one patient, in whom re-vascularization surgery was performed successfully, discontinued warfarin therapy himself at 10 months after surgery, graft occlusion and limb loss occurred at 30 months after surgery. This initial experience suggests that protein C and/or S deficiency may be an independent risk factor for peripheral arterial insufficiency. Patients who present with peripheral arterial insufficiency and protein C and/or S deficiency demonstrate characteristic angiographic findings. Once the diagnosis of protein C and/or S deficiency is made, patients should be treated with life-long anticoagulation.
Assuntos
Doenças Vasculares Periféricas/etiologia , Deficiência de Proteína C/complicações , Deficiência de Proteína S/complicações , Trombose/etiologia , Adulto , Idoso , Anticoagulantes/uso terapêutico , Feminino , Artéria Femoral/diagnóstico por imagem , Artéria Femoral/patologia , Humanos , Artéria Ilíaca/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Doenças Vasculares Periféricas/diagnóstico por imagem , Doenças Vasculares Periféricas/terapia , Estudos Prospectivos , Deficiência de Proteína C/tratamento farmacológico , Deficiência de Proteína S/tratamento farmacológico , Radiografia , Fatores de Risco , Trombose/diagnóstico por imagem , Trombose/terapia , Resultado do TratamentoRESUMO
An organism, identified as Mycobacterium phlei GTIS10, was isolated based on its ability to use dibenzothiophene (DBT) as a sole source of sulfur for growth at 30-52 degrees C. Similar to other biodesulfurization-competent organisms, M. phlei GTIS10 converts DBT to 2-hydroxybiphenyl (2-HBP), as detected by HPLC. The specific desulfurization activity of the 50 degrees C M. phlei GTIS10 culture was determined to be 1.1+/-0.07 micromol 2-HBP min(-1) (g dry cell)(-1). M. phlei GTIS10 can also utilize benzothiophene and thiophene as sulfur sources for growth. The dszABC operon of M. phlei GTIS10 was cloned and sequenced and was found to be identical to that of Rhodococcus erythropolis IGTS8. The presence of the R. erythropolis IGTS8 120-kb plasmid pSOX, which encodes the dszABC operon, has been demonstrated in M. phlei GTIS10. Even though identical dsz genes are contained in both cultures, the temperature at which resting cells of R. erythropolisIGTS8 reach the highest rate of DBT metabolism is near 30 degrees C whereas the temperature that shows the highest activity in resting cell cultures of M. phlei GTIS10 is near 50 degrees C, and activity is detectable at temperatures as high as 57 degrees C. In M. phlei GTIS10, the rate-limiting step in vivo appears to be the conversion of DBT to dibenzothiophene sulfone catalyzed by the product of the dszC gene, DBT monooxygenase. The thermostability of individual desulfurization enzymes was determined and 2-hydroxybiphenyl-2-sulfinate sulfinolyase, encoded by dszB, was found to be the most thermolabile. These results demonstrate that the thermostability of individual enzymes determined in vitro is not necessarily a good predictor of the functional temperature range of enzymes in vivo.
Assuntos
DNA Bacteriano/genética , Mycobacterium/isolamento & purificação , Tiofenos/metabolismo , DNA Bacteriano/química , Temperatura Alta , Mycobacterium/genética , Mycobacterium/metabolismo , Oxirredutases/química , Oxirredutases/genética , Oxigenases/química , Oxigenases/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNARESUMO
Four new coumarin monoterpene ethers, artekeiskeanols A-D (1-4), and three known coumarins, isofraxidin, fraxidin, and daphnoretin, were isolated from the whole plants of Artemisia keiskeana. All structures were determined from spectral data, and that of artekeiskeanol A (1) was confirmed by synthesis.
Assuntos
Cumarínicos/isolamento & purificação , Éteres/isolamento & purificação , Plantas Medicinais/química , Terpenos/isolamento & purificação , Alcaloides/química , Alcaloides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Cumarínicos/química , Éteres/química , Coreia (Geográfico) , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta , Terpenos/químicaRESUMO
AIMS: To develop molecular tools and examine inducible and constitutive gene expression in Thermus thermophilus. METHODS AND RESULTS: Two plasmid promoter probe vectors and an integrative promoter probe vector were constructed using a promoterless thermostable kanamycin nucleotidyltransferase (KmR) cassette. Three expression vectors were constructed based on a constitutive promoter J17, that functions in both Thermus and Escherichia coli. An inducible expression vector was constructed using the heat-shock inducible promoter (70 to 85 degrees C) from the dnaK gene of T. flavus, and the malate dehydrogenase gene (mdh) from T. flavus was cloned and expressed in both E. coli and T. thermophilus HB27. CONCLUSION: This report describes the construction and use of improved promoter probe and expression vectors for use in Thermus species. The mdh gene can be used as a high temperature (85 degrees C) reporter gene for Thermus sp. The dnaK promoter is thermo-inducible. SIGNIFICANCE AND IMPACT OF THE STUDY: The expression vectors and molecular tools described here are significant improvements over previously reported vectors for Thermus sp. The mdh gene and the thermo-inducible dnaK promoter will facilitate high temperature studies employing Thermus species.
Assuntos
Proteínas de Escherichia coli , Regulação Bacteriana da Expressão Gênica , Vetores Genéticos/genética , Thermus thermophilus/genética , Proteínas de Choque Térmico HSP70/genética , Malato Desidrogenase/genética , Plasmídeos/genética , TemperaturaRESUMO
Eleven new briarane-type diterpene lactones, designated milolides (1--8, 10--12), together with four known diterpene lactones (9, 13--15), were isolated from the Micronesian octocoral Briareum stechei collected at Yap, Federated States of Micronesia. One aspect of the stereochemistry of one of the known compounds, solenolide C (9), is revised. Structures of the new compounds were determined from spectral data.
Assuntos
Cnidários/química , Diterpenos/química , Animais , Espectroscopia de Ressonância Magnética , Micronésia , Conformação Molecular , Espectrofotometria InfravermelhoRESUMO
A new extended-spectrum beta-lactamase with an isoelectric point (pI) of 6.2 was detected in Klebsiella pneumoniae F161 that was isolated from a patient with infection. This strain was highly resistant to the third or fourth generation cephalosporins such as ceftazidime, ceftriaxone, cefoperazone, and cefpirome. Analysis of this strain by the double disk diffusion test showed synergies between amoxicillin-clavulanate (AMX-CA) and cefotaxime, and AMX-CA and aztreonam, which suggested that this strain produced a extended-spectrum beta-lactamase (ESBL). Genetic analysis revealed that the resistance was due to the presence of a 9.4-kb plasmid, designated as pKP161, encoding for new beta-lactamase gene (bla). Sequence analysis showed that a new bla gene of pKP161 differed from bla(TEM-1) by three mutations leading to the following amino acid substitutions: Val84 --> Ile, Ala184 --> Val, and Gly238 --> Ser. These mutations have not been reported previously in the TEM type beta-lactamases produced by clinical strains. The novel beta-lactamase was overexpressed in E. coli and purified by ion exchange chromatography on Q-Sepharose and CM-Sepharose, and then further purified by gel filtration on Sehadex G-200. The catalytic activity of the purified beta-lactamase was confirmed by the nitrocefin disk.
Assuntos
Cefalosporinas/metabolismo , Klebsiella pneumoniae/enzimologia , Plasmídeos , beta-Lactamases/fisiologia , Sequência de Aminoácidos , Humanos , Hidrólise , Focalização Isoelétrica , Klebsiella pneumoniae/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , beta-Lactamases/química , beta-Lactamases/genéticaRESUMO
Two new sesquiterpenes, pelorol (1) and 5-epi-smenospongine (2), and seven known ones (3-9) were isolated from the sponge Petrosaspongia metachromia, collected from Yap, Federated States of Micronesia. Their structures were determined from spectral data. Pelorol (1) possesses a new carbon skeleton.