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1.
Hong Kong J Occup Ther ; 32(1): 62-68, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31217763

RESUMEN

OBJECTIVE: This study aimed to translate, culturally adopt and validate a Chinese version of the Disabilities of the Arm, Shoulder and Hand (DASH) for use in patients with upper extremity musculoskeletal diseases in Hong Kong. METHODS: We followed a standard five-stage process: forward translation, synthesis, backward translation, expert panel review and field-testing to achieve linguistic and conceptual equivalence. The version was officially known as Chinese (Queen Mary Hospital, Hong Kong version) DASH. (Chinese QMH,HK version DASH) (http://www.dash.iwh.on.ca/sites/dash/public/translations/DASH_Chinese_HK_2013.pdf). RESULTS: Its internal consistency was then evaluated with 138 participants suffering from upper extremity musculoskeletal conditions. The results were high in DASH-Disability/Symptom module (DASH-DS) (Cronbach alpha 0.97), DASH-Work module (DASH-W) (Cronbach alpha 0.97) and DASH-Sports / Performing Arts module (DASH-SM) (Cronbach alpha 0.99). The test-retest reliability was evaluated with a subgroup of participants who had completed the Chinese (QMH,HK version) DASH on two occasions, with a median interval of 6.5 days. The results were excellent among DASH-DS Intraclass Correlation Coefficient (ICC) = 0.98 and DASH-W (ICC = 0.90). Good test-retest reliability was found in DASH-SM (ICC = 0.89). Construct validity of DASH-DS showed good correlation with the sub-domains of physical functioning (r = -.564) and social functioning (r = -.544) of the Short Form 36 Health Survey (SF-36). Similarly, construct validity of DASH-W also showed good correlation with the sub-domains of physical functioning (r = -.510) and bodily pain (r = -.503) of SF-36. CONCLUSION: The Chinese (Queen Mary Hospital, Hong Kong version) Disabilities of the Arm, Shoulder and Hand is considered as a reliable and valid instrument that can provide a standardised measure of patient-centred outcomes for patients with upper extremity musculoskeletal disorders in Hong Kong.

3.
Bioresour Technol ; 140: 385-91, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23711944

RESUMEN

Cu, Ni and Fe oxides supported on ceria were investigated for their performance as oxygen carriers during the chemical looping combustion of biomass-derived syngas. A complex gas mixture containing CO, H2, CO2, CH4 and other hydrocarbons was used to simulate the complex fuel gas environment derived from biomass gasification. Results show that the transfer of the stored oxygen into oxidants for the supported Cu and Ni oxides at 800°C for the combustion of syngas was effective (>85%). The unsupported Cu oxide showed high oxygen carrying capacity but particle sintering was observed at 800°C. A reaction temperature of 950°C was required for the supported Fe oxides to transfer the stored oxygen into oxidants effectively. Also, for the complex fuel gas environment, the supported Ni oxide was somewhat effective in reforming CH4 and other light hydrocarbons into CO, which may have benefits for the reduction of tar produced during biomass pyrolysis.


Asunto(s)
Biocombustibles , Biomasa , Biotecnología/métodos , Cerio/química , Oxígeno/química , Reactores Biológicos , Rastreo Diferencial de Calorimetría , Calor , Oxidación-Reducción , Termogravimetría , Difracción de Rayos X
4.
Pathology ; 45(4): 382-7, 2013 06.
Artículo en Inglés | MEDLINE | ID: mdl-23635815

RESUMEN

AIMS: To assess the significance of intra-luminal tumour cells (ILTC) within the fallopian tubes of patients with endometrial carcinoma, with emphasis on high grade histological subtypes. METHODS: Complete histological examination of fallopian tube tissue was performed in 36 low grade endometrioid adenocarcinomas and in a consecutive series of 226 high grade endometrial malignancies including 92 serous carcinomas, 64 grade 3 endometrioid carcinomas, 26 carcinosarcomas, 25 undifferentiated/dedifferentiated carcinomas, and 19 clear cell carcinomas. The presence of ILTC was correlated with peritoneal fluid cytology, histologically confirmed peritoneal tumour spread, and lymph node metastases. RESULTS: ILTC were identified in 26% and 3% of high and low grade carcinomas, respectively. The presence of ILTC correlated strongly with positive peritoneal fluid cytology and with peritoneal metastasis in high grade tumours (both p < 0.001), and there was also a correlation with lymph node metastasis (p = 0.049). ILTC were more common in serous and undifferentiated carcinomas (>30%) but the differences between the high grade tumour subtypes were not statistically significant. CONCLUSIONS: These findings suggest that ILTC associated with high grade endometrial cancers have the capacity to implant and invade the peritoneal cavity. Positive cytology in such cases may be more significant than in low grade tumours. Complete tubal examination may provide additional prognostic information in high grade endometrial carcinoma.


Asunto(s)
Adenocarcinoma/secundario , Líquido Ascítico/patología , Carcinosarcoma/secundario , Neoplasias Endometriales/patología , Trompas Uterinas/patología , Adenocarcinoma de Células Claras/secundario , Carcinoma Endometrioide/secundario , Cistadenocarcinoma Seroso/secundario , Femenino , Humanos , Ganglios Linfáticos/patología , Metástasis Linfática , Clasificación del Tumor , Invasividad Neoplásica , Neoplasias Peritoneales/secundario , Estudios Prospectivos
5.
Pathology ; 41(5): 454-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19900084

RESUMEN

AIMS: To investigate the frequency of microcystic, elongated and fragmented (MELF) pattern invasion in endometrial carcinoma and its association with other pathological findings. METHODS: The histology slides from 170 consecutively accessioned endometrial malignancies were reviewed to identify cases showing MELF type invasion. Histological subtype, tumour grade, presence of squamous and mucinous differentiation, and frequency of lymphovascular space invasion (LVSI) were compared in MELF positive and negative cases. Additional stains for cytokeratin and stromal mucin were performed in the MELF positive tumours and immunohistochemistry to demonstrate vascular endothelium was performed in 12 selected cases. RESULTS: There were 133 endometrioid adenocarcinomas (EEC) and 37 non-endometrioid carcinomas. MELF type invasion was identified in 27 cases (15.9%) all of which were FIGO grade 1 or 2 myoinvasive adenocarcinomas of endometrioid type. The histochemical and immunohistochemical stains were useful in demonstrating the relatively subtle invasive foci in some tumours. MELF positive cases more frequently showed focal mucinous differentiation and LVSI. CONCLUSIONS: MELF type invasion appears restricted to low grade, myoinvasive carcinomas of endometrioid type and is more common in tumours exhibiting focal mucinous differentiation. These associations suggest that MELF changes represent a specific tumour-stromal interaction rather than a degenerative process. Tumours exhibiting MELF pattern invasion should be carefully examined for LVSI. Ancillary techniques, in particular cytokeratin immunohistochemistry, are useful in diagnostic assessment.


Asunto(s)
Carcinoma/patología , Neoplasias Endometriales/patología , Diferenciación Celular , Femenino , Humanos
7.
Cancer Lett ; 277(1): 91-100, 2009 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-19138817

RESUMEN

Human hepatocellular carcinoma (HCC) has an elevated requirement for arginine in vitro, and pegylated recombinant human arginase I (rhArg-PEG), an arginine-depleting enzyme, can inhibit the growth of arginine-dependent tumors. While supplementation of the culture medium with ornithine failed to rescue Hep3B cells from growth inhibition induced by rhArg-PEG, citrulline successfully restored cell growth. The data support the roles previously proposed for ornithine transcarbamylase (OTC) in the arginine auxotrophy and rhArg-PEG sensitivity of HCC cells. Expression profiling of argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL) and OTC in 40 HCC tumor biopsy specimens predicted that 16 of the patients would be rhArg-sensitive, compared with 5 who would be sensitive to arginine deiminase (ADI), another arginine-depleting enzyme with anti-tumor activity. Furthermore, rhArg-PEG-mediated deprivation of arginine from the culture medium of different HCC cell lines produced cell cycle arrests at the G(2)/M or S phase, possibly mediated by transcriptional modulation of cyclins and/or cyclin dependent kinases (CDKs). Based on these results, together with further validation of the in vivo efficacy of rhArg-PEG against HCC, we propose that the application of rhArg-PEG alone or in combination with existing chemotherapeutic drugs may represent a specific and effective therapeutic strategy against HCC.


Asunto(s)
Antineoplásicos/farmacología , Arginasa/farmacología , Carcinoma Hepatocelular/tratamiento farmacológico , Ciclo Celular/efectos de los fármacos , Neoplasias Hepáticas/tratamiento farmacológico , Animales , Arginasa/uso terapéutico , Carcinoma Hepatocelular/enzimología , Carcinoma Hepatocelular/patología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Citrulina/metabolismo , Citrulinemia/epidemiología , Quinasa 2 Dependiente de la Ciclina/análisis , Ciclinas/análisis , Humanos , Neoplasias Hepáticas/enzimología , Neoplasias Hepáticas/patología , Ratones , Enfermedad por Deficiencia de Ornitina Carbamoiltransferasa/epidemiología , Proteínas Recombinantes/farmacología , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Cancer Lett ; 224(1): 67-80, 2005 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-15911102

RESUMEN

Hepatocellular carcinoma (HCC) is auxotrophic for the semi-essential amino acid arginine, depletion of which leads to tumor death. In humans, arginine is not an essential amino acid since many adult somatic cells can re-synthesize it from other sources, such as citrulline. Enzymes capable of depleting arginine in vitro include the urea cycle enzyme arginase, which is found in abundance in human liver. For over three decades, arginase has not been considered as a potential drug candidate because of its low substrate affinity, short circulatory half-life and sub-optimal enzymatic activity at physiological pH, though its in vitro anti-tumor activities in certain tumors have been amply reported. Arginine deiminase, a bacterial enzyme from Mycoplasma hominus has been shown to induce HCC remission through the mechanism of arginine depletion. We report here an innovative treatment approach for the treatment of locally advanced and metastatic HCC with transhepatic arterial embolisation (TAE) of the liver tumor with lipiodol and gel foam as a means of inducing a leakage of hepatic arginase from the liver into the circulation. Hepatic arginase released into the systemic circulation rapidly depleted plasma arginine. High-dose insulin was included to induce a state of hypoaminoacidaemia to augment arginine depletion. With this protocol, we have treated seven patients with locally advanced and/or metastatic HCC. Five patients achieved arginine depletion, ranging from 0 to 20 microM (normal plasma level 100-120 microM); all had varying degrees of tumor remission in their primary tumors and extra-hepatic sites in the lymph nodes, lungs and bones, suggesting systemic anti-cancer effect of arginine depletion. The two non-responders did not show significant reduction in plasma arginine. Based on our findings, we propose that the urea cycle enzyme, arginase, is a good drug candidate for the treatment of HCC.


Asunto(s)
Arginasa/metabolismo , Arginina/metabolismo , Arginina/farmacocinética , Carcinoma Hepatocelular/tratamiento farmacológico , Embolización Terapéutica , Hipoglucemiantes/farmacología , Hipoglucemiantes/uso terapéutico , Insulina/farmacología , Insulina/uso terapéutico , Neoplasias Hepáticas/tratamiento farmacológico , Adulto , Anciano , Femenino , Humanos , Hipoglucemiantes/administración & dosificación , Insulina/administración & dosificación , Hígado/química , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
9.
Gynecol Oncol ; 84(1): 53-7, 2002 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-11748976

RESUMEN

OBJECTIVES: The aim of this study was to assess the technique of en bloc resection of ovarian cancer with concomitant rectosigmoid colectomy, in relation to perioperative complication rates, and its impact on survival following the procedure. METHODS: A retrospective review was performed of the case notes of 129 consecutive procedures performed between 1989 and 2000 in a regional cancer center. RESULTS. Overall, 48.8% of patients suffered a major or minor complication. Complications relating to bowel anastomosis occurred in 2.4%. Perioperative mortality was 3.1%. Median survival for the group as a whole was 30.6 months. Patients who were optimally debulked had a significantly longer median survival time. CONCLUSION: En bloc resection of ovarian cancer with concomitant rectosigmoid colectomy allows a high rate of optimal debulking with acceptable morbidity, mortality, and survival.


Asunto(s)
Colectomía/métodos , Neoplasias Ováricas/cirugía , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Procedimientos Quirúrgicos Ginecológicos/métodos , Humanos , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Tasa de Supervivencia
10.
Appl Biochem Biotechnol ; 91-93: 515-24, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11963881

RESUMEN

Plastic wastes are considered to be severe environmental contaminants causing waste disposal problems. Widespread use of biodegradable plastics is one of the solutions, but it is limited by high production cost. Biologic wastewater treatment generates large quantities of biomass as activated sludge. Only a few reports focus on the potential of utilizing resident Bacillus species from activated sludge in polyhydroxbutyrate (PHB) production as well as the production of PHB from food wastes. They have attractive properties such as short generation time, absence of endotoxins, and secretion of both amylases and proteinases that can well utilize food wastes for nutrients, which can further reduce the cost of production of polyhydroxyalkanoates (PHAs). Two PHA-producing strains, HF-1 and HF-2, were isolated from activated sludge. HF-1 outperformed HF-2 in terms of growth and PHB production in hydrolyzed soy and malt wastes. The isolated bacteria was characterized by DNA sequence alignment. Cell extracts of HF-1 were also compared to Bacillus megaterium cell extracts on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The biopolymers accumulated were analyzed by gas chromatography, nuclear magnetic resonance, and Fourier transform infrared methods.


Asunto(s)
Bacillus/aislamiento & purificación , Bacillus/metabolismo , Biopolímeros/biosíntesis , Hidroxibutiratos/metabolismo , Poliésteres/metabolismo , Aguas del Alcantarillado/microbiología , Bacillus megaterium/metabolismo , Biodegradación Ambiental , Biomasa , Biopolímeros/química , Biopolímeros/aislamiento & purificación , Fermentación , Manipulación de Alimentos , Hidroxibutiratos/química , Hidroxibutiratos/aislamiento & purificación , Residuos Industriales , Poliésteres/química , Poliésteres/aislamiento & purificación
11.
Tech Hand Up Extrem Surg ; 5(1): 63-70, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16520650
12.
Appl Biochem Biotechnol ; 84-86: 381-90, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10849804

RESUMEN

Construction and comparison of recombinant Escherichia coli strains harboring the polyhydroxybutyrate (PHB) operon from Ralstonia eutropha using vectors possessing different promotors, as well as the production of PHB from soy waste by the recombinant strain, are reported. The lac promotor was the most efficient on expression of the phb operon among the three promotors studied: i.e., lac promotor, T7 promotor and the normal sigma 70 promotor. The pKS/PHB was the most efficient plasmid for phb operon expression among the three plasmids used: i.e., pKS-, pAED4, and pJM9131. It was observed that isopropyl-beta-D-thiogalactopyranoside was not required for the induction of the expression of phb operon. The cell dry wt and polyhydroxyalkanoate content by E. coli XL-1 Blue (pKS/PHB) were 3.025 g/L and 27.83%, respectively.


Asunto(s)
Escherichia coli/genética , Escherichia coli/metabolismo , Glycine max , Hidroxibutiratos , Residuos Industriales , Operón , Cupriavidus necator/genética , Escherichia coli/crecimiento & desarrollo , Plásmidos , Regiones Promotoras Genéticas , Recombinación Genética , Espectroscopía Infrarroja por Transformada de Fourier
13.
Protein Sci ; 9(5): 846-58, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10850794

RESUMEN

The solution structure and backbone dynamics of Cu(I) pseudoazurin, a 123 amino acid electron transfer protein from Paracoccus pantotrophus, have been determined using NMR methods. The structure was calculated to high precision, with a backbone RMS deviation for secondary structure elements of 0.35+/-0.06 A, using 1,498 distance and 55 torsion angle constraints. The protein has a double-wound Greek-key fold with two alpha-helices toward its C-terminus, similar to that of its oxidized counterpart determined by X-ray crystallography. Comparison of the Cu(I) solution structure with the X-ray structure of the Cu(II) protein shows only small differences in the positions of some of the secondary structure elements. Order parameters S2, measured for amide nitrogens, indicate that the backbone of the protein is rigid on the picosecond to nanosecond timescale.


Asunto(s)
Azurina/análogos & derivados , Cobre/química , Paracoccus/química , Amidas/química , Secuencia de Aminoácidos , Azurina/química , Azurina/metabolismo , Simulación por Computador , Cobre/metabolismo , Cristalografía por Rayos X , Concentración de Iones de Hidrógeno , Cinética , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Datos de Secuencia Molecular , Nitrógeno/química , Estructura Secundaria de Proteína , Temperatura
14.
Mech Dev ; 84(1-2): 17-30, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10473117

RESUMEN

The tail bud comprises the caudal extremity of the vertebrate embryo, containing a pool of pluripotent mesenchymal stem cells that gives rise to almost all the tissues of the sacro-caudal region. Treatment of pregnant mice with 100 mg/kg all-trans retinoic acid at 9.5 days post coitum induces severe truncation of the body axis, providing a model system for studying the mechanisms underlying development of caudal agenesis. In the present study, we find that retinoic acid treatment causes extensive apoptosis of tail bud cells 24 h after treatment. Once the apoptotic cells have been removed, the remaining mesenchymal cells differentiate into an extensive network of ectopic tubules, radially arranged around the notochord. These tubules express Pax-3 and Pax-6 in a regionally-restricted pattern that closely resembles expression in the definitive neural tube. Neurofilament-positive neurons subsequently grow out from the ectopic tubules. Thus, the tail bud cells remaining after retinoic acid-induced apoptosis appear to adopt a neural fate. Wnt-3a, a gene that has been shown to be essential for tail bud formation, is specifically down-regulated in the tail bud of retinoic acid-treated embryos, as early as 2 h after retinoic acid treatment and Wnt-3a transcripts become undetectable by 10 h. In contrast, Wnt-5a and RAR-gamma are still detectable in the tail bud at that time. Extensive cell death also occurs in the tail bud of embryos homozygous for the vestigial tail mutation, in which there is a marked reduction in Wnt-3a expression. These embryos go on to develop multiple neural tubes in their truncated caudal region. These results suggest that retinoic acid induces down-regulation of Wnt-3a which may play an important role in the pathogenesis of axial truncation, involving induction of widespread apoptosis, followed by an alteration of tail bud cell fate to form multiple ectopic neural tubes.


Asunto(s)
Proteínas de Homeodominio , Sistema Nervioso/embriología , Proteínas/metabolismo , Cola (estructura animal)/embriología , Factores de Transcripción , Tretinoina/farmacología , Animales , Apoptosis/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Diferenciación Celular , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Relación Dosis-Respuesta a Droga , Regulación hacia Abajo , Embrión de Mamíferos/efectos de los fármacos , Proteínas del Ojo , Femenino , Homocigoto , Masculino , Mesodermo/efectos de los fármacos , Mesodermo/metabolismo , Ratones , Ratones Endogámicos ICR , Mutación , Sistema Nervioso/efectos de los fármacos , Sistema Nervioso/metabolismo , Malformaciones del Sistema Nervioso/inducido químicamente , Malformaciones del Sistema Nervioso/embriología , Neuronas , Factor de Transcripción PAX3 , Factor de Transcripción PAX6 , Factores de Transcripción Paired Box , Embarazo , Proteínas/efectos de los fármacos , Proteínas Represoras , Cola (estructura animal)/citología , Cola (estructura animal)/efectos de los fármacos , Tretinoina/metabolismo , Proteínas Wnt , Proteína Wnt3 , Proteína Wnt3A
15.
Biochem J ; 321 ( Pt 3): 699-705, 1997 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-9032456

RESUMEN

The pseudoazurin gene from Thiosphaera pantotropha has been cloned and sequenced. The deduced amino acid sequence showed that the protein contains an unusually alanine-rich signal peptide, 22 amino acid residues in length, which targets the protein to the periplasm. This pseudoazurin was expressed in large amounts in the periplasm of Escherichia coli when the gene with its native ribosome-binding site was placed downstream of the lac promoter. Removal of a putative hairpin-forming structure upstream of the ribosome-binding site increased the yield of the purified protein to approximately 80 mg/l. The recombinant protein is indistinguishable from that purified from its natural host. A primer extension study indicated that the pseudoazurin structural gene (pazS) is under the control of the Fnr/Nnr regulatory system, but no promoter-binding sequence could be recognized. The amino acid sequence of pseudoazurin from Paracoccus denitrificans is also reported.


Asunto(s)
Azurina/análogos & derivados , Genes Bacterianos/genética , Paracoccus/química , Secuencia de Aminoácidos , Azurina/química , Secuencia de Bases , Clonación Molecular , Cartilla de ADN , Electroforesis en Gel de Poliacrilamida , Escherichia coli/genética , Expresión Génica/genética , Datos de Secuencia Molecular , Paracoccus denitrificans/química , Paracoccus denitrificans/metabolismo , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Mapeo Restrictivo , Análisis de Secuencia
16.
Int Orthop ; 20(5): 305-10, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8930723

RESUMEN

The position of the patella in the Southern Chinese population is 15 to 20% higher than in Western populations, both in controls and in disease. Those with patellar dislocation and anterior knee pain have significantly higher patellae than the controls in both population groups, and this is confirmed in the 5 methods of measurement we have studied. Patella alta is more common in our region. The patella alta index described in this paper provides a reliable and reproducible measurement of patellar height. A value of more than 3.4 is abnormal in our population.


Asunto(s)
Rótula/anatomía & histología , Adolescente , Adulto , China , Humanos , Luxaciones Articulares/diagnóstico , Articulación de la Rodilla , Persona de Mediana Edad , Dolor/etiología , Rótula/diagnóstico por imagen , Rótula/lesiones , Radiografía , Valores de Referencia
17.
Nat Struct Biol ; 2(11): 975-82, 1995 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7583671

RESUMEN

The structure of pseudoazurin from Thiosphaera pantotropha has been determined and compared to structures of both soluble and membrane-bound periplasmic redox proteins. The results show a matching set of unipolar, but promiscuous, docking motifs based on a positive hydrophobic surface patch on the electron shuttle proteins pseudoazurin and cytochrome c550 and a negative hydrophobic patch on the surface of their known redox partners. The observed electrostatic handedness is argued to be associated with the charge-asymmetry of the membrane-bound components of the redox chain due to von Heijne's 'positives-inside' principle. We propose a 'positives-in-between' rule for electron shuttle proteins, and expect a negative hydrophobic patch to be present on both the highest and lowest redox potential species in a series of electron carriers.


Asunto(s)
Azurina/análogos & derivados , Transporte de Electrón , Azurina/química , Azurina/metabolismo , Cristalografía por Rayos X , Grupo Citocromo c/química , Grupo Citocromo c/metabolismo , Citocromos/química , Citocromos/metabolismo , Bacterias Gramnegativas Quimiolitotróficas/química , Modelos Moleculares , Nitrito Reductasas/química , Nitrito Reductasas/metabolismo , Conformación Proteica
18.
Gene ; 154(1): 1-6, 1995 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-7867934

RESUMEN

A defective prophage vector, phi 105MU331, for high-level protein overproduction in Bacillus subtilis, was derived by random insertion of a lacZ reporter gene. The site of insertion not only provided efficient inducible transcription of heterologous genes, but also prevented lysis of the host cell. The region of the insertion in phi 105MU331 lies close to the right cohesive end of phi 105. DNA sequence analysis revealed that this region of phi 105 somewhat resembles the lysis cassette of various phages, including lambda. The site of insertion lies in a possible 'holin' gene, which could explain the block in host cell lysis. Dual promoters apparently responsible for the strong inducible transcription lie in an untranslated region just upstream from the putative holin gene. This region is probably equivalent to the site of the major late promoter and antiterminator of the lambdoid phages. The sequence features could, thus, account for the useful properties of the phi 105MU331 vector system.


Asunto(s)
Fagos de Bacillus/genética , Bacillus subtilis/virología , Bacteriólisis , Regulación Viral de la Expresión Génica , Vectores Genéticos/genética , Mutagénesis Insercional , Secuencia de Aminoácidos , Fagos de Bacillus/química , Fagos de Bacillus/fisiología , Secuencia de Bases , Clonación Molecular/métodos , Genes Reporteros , Datos de Secuencia Molecular , Regiones Promotoras Genéticas , Estructura Terciaria de Proteína , Transcripción Genética
19.
Biochem J ; 299 ( Pt 3): 671-8, 1994 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-7910734

RESUMEN

Two Glu-166 mutants of beta-lactamase I from Bacillus cereus 569/H were constructed: one with a lengthened side chain (E166Cmc, the S-carboxymethylcysteine mutant) and the other with the side chain shortened and made non-polar (E166A). Their kinetic properties were studied and compared with those of the wild-type and the E166D mutant (with a shortened side chain) previously made by Gibson, Christensen and Waley (1990) (Biochem. J. 272, 613-619). Surprisingly, with good penicillin substrates, Km, kcat. and kcat./Km of the two conservative mutants (E166Cmc and E166D) are similar to those of the non-conservative mutant E166A. Their kcat. values are 3000-fold lower than that of the wild-type enzyme, showing that Glu-166 is a very important residue. The acylenzyme intermediate of E166A and a good substrate, penicillin V, was trapped by acid-quench and observed by electrospray ionization mass spectrometry, suggesting that Glu-166 is more important in catalysing the deacylation step than the acylation step. The beta-lactamase I E166A mutant is about 200-fold more active than the Bacillus licheniformis E166A mutant with nitrocefin or 6 beta-furylacryloyl-amidopenicillanic acid as substrate. This suggested that other groups in the active site of the beta-lactamase I mutant may activate the catalytic water molecule for deacylation.


Asunto(s)
Glutamatos/metabolismo , Mutagénesis Sitio-Dirigida , Penicilinasa/metabolismo , Secuencia de Aminoácidos , Bacillus cereus/enzimología , Secuencia de Bases , Sitios de Unión , Glutamatos/genética , Ácido Glutámico , Cinética , Espectrometría de Masas , Datos de Secuencia Molecular , Oligodesoxirribonucleótidos , Penicilinasa/genética , Penicilinasa/aislamiento & purificación , Procesamiento Proteico-Postraduccional
20.
Aust N Z J Obstet Gynaecol ; 33(2): 216-7, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8216132

RESUMEN

This report discusses the limitations of using the serum tumour marker CA 125 in the preoperative evaluation of a woman presenting with a pelvic mass. We present 2 cases of benign struma ovarii which were associated with elevated levels of CA 125.


Asunto(s)
Antígenos de Carbohidratos Asociados a Tumores/sangre , Neoplasias Ováricas/diagnóstico , Estruma Ovárico/diagnóstico , Anciano , Ascitis/complicaciones , Femenino , Humanos , Persona de Mediana Edad , Neoplasias Ováricas/complicaciones , Estruma Ovárico/complicaciones
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