bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inducible expression of Bcl‐XL restricts apoptosis resistance to the antibody secretion phase in hybridoma cultures
Authors: Jung Daniel , Côté Serge , Drouin Mathieu , Simard Carl , Lemieux Réal 
Published: October 2002

AbstractB‐cell hybridomas are widely used to produce monoclonal antibodies via large‐scale cell culture. Unfortunately, these cells are highly sensitive to apoptotic death under conditions of nutrient deprivation observed at the plateau phase of batch cultures. Previous work has indicated that constitutive high‐level expression of antiapoptotic genes in hybridoma cells could delay apoptosis, resulting in higher cell densities and prolonged viability. However, the constitutive high‐level expression of antiapoptotic genes has been shown to have detrimental effects on genomic stability of other types of cultured cells. Inducible gene expression may be used to avoid this problem. In the present study, we first constructed an expression vector in which the promoter of a mammalian metallothionein (MT) gene drives the expression of bcl‐XL in response to metal exposure. The vector was then used to exogenously control the expression of bcl‐XL in D5 hybridoma cells. Our data show that stably transfected D5 cells (4G1.D9) expressed high levels of Bcl‐XL following overnight exposure to ZnSO4 concentrations (50 to 100 μM) that did not affect control cells. The level of Bcl‐XL expressed after ZnSO4 induction was sufficient to prevent apoptosis experimentally induced by cycloheximide and allowed 4G1.D9 cells to grow at higher densities and remain viable for prolonged periods in suboptimal culture conditions. The use of inducible bcl‐XL expression permits extension of the viability of cultured B‐cell hybridomas during the antibody secretion phase without the adverse genetic effects associated with constitutive long‐term bcl‐XL expression. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 180–187, 2002.
Development of (R)‐4‐hydroxymandelonitrile synthesis in an aqueous–organic biphasic stirred tank batch reactor
Authors: Willeman W. F. , Neuhofer R. , Wirth I. , Pöchlauer P. , Straathof A. J. J. , Heijnen J. J. 
Published: October 2002

AbstractA relatively new hydroxynitrile lyase‐catalyzed reaction was optimized to be suitable for rapid and efficient development of a full‐scale production process. The conversion of 4‐hydroxybenzaldehyde into (R)‐4‐hydroxymandelonitrile, catalyzed by Prunus amygdalus hydroxynitrile lyase, was carried out in a biphasic system of aqueous buffer (pH 5.5) and methyl tert‐butyl ether and is described with a process model. The process model consists of a description of the reaction kinetics, mass transfer kinetics, and mass balances for both the aqueous and the organic phase. Values are determined for the equilibrium constant, the enzyme kinetic parameters, the lumped mass transfer coefficient for benzaldehyde, and the partition coefficients. By using estimated prices of enzyme and reactor use, the optimum aqueous phase volume fraction and required enzyme concentration were calculated at a temperature of 20°C for a batch‐operated stirred tank reactor. According to the process model it was possible to convert 90% of the 4‐hydroxybenzaldehyde into (R)‐4‐hydroxymandelonitrile with 95% enantiomeric excess. The price optimum for this reaction was found at an aqueous phase volume of 17% of the total volume. The required enzyme concentration to meet the targets was 28.6 g/L aqueous phase. At the predicted optimum, the synthesis was performed experimentally and the results were in accordance with the simulation regarding the extent of conversion and the enantiomeric excess. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 154–164, 2002.
Kinetics of benzene biotransformation under microaerophilic and oxygen‐limited conditions
Authors: Yerushalmi Laleh , Lascourreges Jean‐Francois , Guiot Serge R. 
Published: October 2002

AbstractA special microbial consortium adapted to degrade petroleum hydrocarbons at limited availability of oxygen, transformed benzene, a highly toxic and carcinogenic contaminant of groundwater and soil, at low initial dissolved oxygen (DO) concentrations of 0.05–2 mg/L. The employed initial concentrations of dissolved oxygen were considerably lower than the previously reported values. Under these conditions, the overall transformation of benzene ranged from 34% ± 1.7% to 100%, considerably higher than the theoretical predictions for complete mineralization of benzene based on the requirement of 3.08 mg oxygen/mg benzene. Unlike biotransformation that proceeded at the lowest examined DO concentration of 0.05 mg/L, the mineralization of benzene, defined by its conversion to CO2 and water, required a minimum DO concentration of 0.2 mg/L. The mineralization of benzene under microaerophilic conditions (DO < 2 mg/L), ranged from 0.83% ± 0.06% to 89% ± 1.3%, which was less than the theoretical predictions at any given initial DO concentration. The regulatory effects of dissolved oxygen concentration or its partial pressure on the activities of enzymes catalyzing the biotransformation of aromatic hydrocarbons was postulated to account for the reduced mineralization of benzene. The ratio between the transformed benzene and the consumed oxygen increased with the decrease of initial DO concentration, reaching a value of 2.8, considerably higher than the theoretical value of 0.33 obtained for a complete aerobic oxidation of benzene. Phenol was the major and the most stable intermediate metabolite during the biotransformation of benzene at low concentrations of DO. While benzene transformation stopped after the depletion of oxygen in the experimental system, phenol continued to accumulate under strictly anaerobic conditions, indicating its formation from an alternative carbon source, possibly biomass. © 2002 Government of Canada. Exclusive worldwide publication rights in this article have been transferred to Wiley Periodicals, Inc. Biotechnol Bioeng 79: 347–355, 2002.
Overexpression of an archaeal protein in yeast: Secretion bottleneck at the ER
Authors: Smith Jason D. , Robinson Anne Skaja 
Published: October 2002

AbstractArchaeal enzymes have great potential for industrial use; however, expressing them in their natural hosts has proven challenging. Growth conditions for many archaea are beyond typical fermentation capabilities, and to compound the problem, archaea generally achieve much lower biomass yields than Escherichia coli or Saccharomyces cerevisiae. To determine whether a eukaryotic host, S. cerevisiae, would be a suitable alternative for archaeal protein production, we examined the expression of the tetrameric β‐glucosidase from the hyperthermophilic archaeon Pyrococcus furiosus. We engineered the β‐glucosidase to facilitate secretion into the culture medium and have demonstrated the β‐glucosidase's secretion and activity. We determined the dependence of β‐glucosidase secretion on gene copy number and obtained a transformant capable of secreting ∼10 mg/L in batch culture. All transformants retained large intracellular fractions of β‐glucosidase, indicative of an intracellular bottleneck. Cell fractionation by sucrose density centrifugation and immunofluorescence identified the endoplasmic reticulum as the secretion bottleneck. Preliminary evidence indicates that the cause of this bottleneck is misfolding of the monomeric β‐glucosidase, rather than tetrameric association. Expression at moderately elevated temperatures (between 30 and 40°C) improved β‐glucosidase yields, suggesting that higher temperature expression may improve folding and secretion yields. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 713–723, 2002.
Jay Bailey as mentor—The students' perspective
Authors: Reardon Kenneth F. , Lee Kelvin H. , Wittrup K. Dane , Hatzimanikatis Vassily 
Published: October 2002

AbstractProfessor James E. Bailey was not only a world‐renowned leader and pioneer in biochemical engineering but also a mentor to the many graduate students and postdoctoral researchers in his group. To provide non‐“Bailey‐ites” with an impression of Jay as a mentor, we begin with a brief review of his career, focusing on the dynamics of the research group. Typical student experiences of being part of the Bailey group are then discussed, including the recognition of a particular research style and Jay's expectations for hard work. Finally, we provide some thoughts on Jay's mentoring style, which was marked by an ability to foster independence, a sense of quality, and passion for research. Jay's contributions as a mentor can perhaps be recognized as being as significant as his research achievements. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 484–489, 2002.
Inguinal canal ‘lipoma’
Authors: Heller C. Ann , Marucci Damian D. , Dunn Tirith , Barr Elizabeth M. , Houang Michael , Dos Remedios Cristobal 
Published: October 2002

AbstractGroin dissection was performed in adult male post‐mortem subjects to establish the prevalence of inguinal canal ‘lipoma.’ Thirty‐six body halves (age range 24–92 years) were studied. Of these, 27 (75%) contained a discrete mass of fat within the inguinal canal. This mass was always continuous with the preperitoneal fat through the deep inguinal ring. Nineteen of these 27 masses (70%), displayed a characteristic pedunculated form with a bulbous distal end. Eighteen of the 36 dissections (50%), revealed a mass more than 4 cm in length. Six dissections showed extension of the mass beyond the superficial inguinal ring and three of these six (8% of the 36 groins studied) showed distortion of the proximal spermatic cord with a mass at the superficial inguinal ring. The masses submitted for histology comprised mature adipose tissue and all but two of these were reported as having an adherent capsule. No significant correlation was found between mass length and either subject age or body mass index (BMI) but a statistically significant correlation between the length of the fat mass on the left and right sides was shown. This study demonstrates that the inguinal canal ‘lipoma’ is a common feature in an adult male population and may be of sufficient size to cause clinical misdiagnosis. The high prevalence, characteristic location and appearance of the ‘lipoma’ suggest a developmental etiology. Clin. Anat. 15:280–285, 2002. © 2002 Wiley‐Liss, Inc.
Development of instructional software for the calculation of form stress concentration factors
Authors: Prater Glen , Shahhosseini Ali M. 
Published: October 2002

AbstractMechanical engineering curricula include a number of required courses in solid mechanics and machine design that involve the determination of stresses in components with geometric irregularities. This article documents the development of a Windows‐based computer program, ME‐StressCon, that allows rapid calculation of form stress concentration factors and nominal stresses for a wide variety of geometry and load cases. © 2002 Wiley Periodicals, Inc. Comput Appl Eng Educ 10: 1–10, 2002; Published online in Wiley InterScience (www.interscience.wiley.com.); DOI 10.1002/cae.10009
Potential goals for the dimensions of the pulmonary arteries and aorta with stenting after the Fontan operation
Authors: Tomita Hideshi , Yazaki Satoshi , Kimura Kohji , Ono Yasuo , Yamada Osamu , Ohuchi Hideo , Yagihara Toshikatsu , Echigo Shigeyuki 
Published: October 2002

AbstractThe purpose of this study was to clarify desired stent sizes for stenotic lesions in the post‐Fontan circulation. Using angiograms from 22 patients before and at late follow‐up (≥ 15 years) after the Fontan operation, we measured the maximum diameters of the proximal pulmonary arteries (PA) and the descending aorta. The diameters of the PA ipsilateral to the inferior vena cava, contralateral to the inferior vena cava, and descending aorta after the Fontan were 10.6–22.6 (15.8 ± 3.3), 8.0–19.1 (12.9 ± 3.1), and 12.1–18.9 (15.8 ± 2.0) mm, respectively, while the percent of normal predicted diameters (% N) were 55%–104% (70% ± 14%), 38%–99% (66% ± 17%), and 46%–74% (60% ± 7%), respectively. Despite somatic growth, the % N of all vessel diameters decreased significantly after the Fontan operation. In conclusion, smaller‐sized stents should be acceptable for both the pulmonary artery and descending aorta in the Fontan circulation. Cathet Cardiovasc Intervent 2002;56:246–253. © 2002 Wiley‐Liss, Inc.
Directional atherectomy of a calcified lesion using a new atherectomy device
Authors: Reimers Bernhard , Stankovic Goran , Prati Francesco , Sommariva Luigi , Karvouni Evangelia , Takagi Takuro , Albiero Remo , Angelini Annalisa , Di Mario Carlo , Thiene Gaetano , Colombo Antonio 
Published: October 2002

AbstractWe report on a case of directional atherectomy performed on a calcified coronary lesion using a novel device with a hardened titanium cutter. The successful removal of calcified plaque was documented by intravascular ultrasound assessment and confirmed by histopathological analysis of the obtained plaque specimen. Cathet Cardiovasc Intervent 2002;56:222–226. © 2002 Wiley‐Liss, Inc.
Intra‐atrial thrombolytic therapy for dissolution of chronic left atrial thrombi in patients undergoing balloon mitral commissurotomy
Authors: Chiang Cheng‐Wen , Chu Po‐Hsien , Hsu Long‐An 
Published: October 2002

AbstractThe purpose of this study was to evaluate the solubility of left atrial thrombi to thrombolytics after failure of long‐term anticoagulant therapy in patient with mitral stenosis. One hundred and eighty‐one consecutive patients with mitral valve area ≤ 1.5 cm2 and without severe mitral regurgitation were screened with echocardiography; 30 were found to have left atrial thrombi. Follow‐up echocardiography performed 7.4 ± 5.6 months after warfarin therapy revealed that 8/30 of patients had complete dissolution and 3/30 had partial dissolution of the thrombi. Thirteen patients with residual isolated appendageal thrombi underwent balloon mitral commissurotomy and were randomized into four groups at the end of balloon mitral commissurotomy: group A, receiving intra‐atrial infusion of heparin and tissue plasminogen activator (t‐PA; n = 4); group B, heparin and streptokinase (n = 3); group C, heparin (n = 3); and group D, acting as control (n = 3). It was found that only two patients in the t‐PA group had their thrombi either completely or partially dissolved within 48 hr. Thus, this study suggests that t‐PA may have the potential of dissolving chronic left atrial thrombi. Cathet Cardiovasc Intervent 2002;56:460–465. © 2002 Wiley‐Liss, Inc.
Elderly patients have a favorable outcome after intracoronary radiation for in‐stent restenosis
Authors: Ajani Andrew E. , Waksman Ron , Cheneau Edouard , Cha Dong‐Hun , Pinnow Ellen , Pichard Augusto D. , Satler Lowell F. , Kent Kenneth M. , Lindsay Joseph 
Published: October 2002

AbstractIntracoronary radiation therapy (IRT) reduces recurrent in‐stent restenosis (ISR) by inhibition of smooth muscle cell proliferation. The ability of these cells to replicate is limited with age due to changes in the telomeres. The purpose of this study was to assess the effect of age on outcomes following IRT for ISR. We evaluated 1,088 patients with 6‐month clinical follow‐up who were enrolled in radiation trials for ISR using γ‐ and β‐emitters. Patients were analyzed within and between IRT (n = 861) or placebo therapy (n = 227) in four age groups (< 55, 55–65, 66–75, > 75 years). Baseline characteristics were similar within each age group of IRT patients, except elderly patients (> 75 years) had a lower rate of diabetes (28% in patients > 75 years; P = 0.008) and a higher rate of previous CABG (59% in patients > 75 years; P < 0.001). The rate of target lesion revascularization (TLR) was reduced in the elderly. TLR at 6 months was 18% in patients < 55 years, 21% in 55–65 years, 12% in 66–75 years, and 10% in patients > 75 (P = 0.009). The MACE rate at 6 months was 21% in patients < 55 years, 29% in 55–65 years, 26% in 66–75 years, and 17% in patients > 75 (P = 0.03). No effect of age was seen in placebo patients. IRT‐treated patients had reduced MACE compared to placebo in all age groups, driven by reduced target vessel revascularization. Age was an independent predictor of MACE at 6 months (OR = 0.8; CI = 0.70–0.93; P = 0.004). Angiographic restenosis was not clearly associated with need for TLR in patients > 75 years. In elderly patients (> 75 years) treated with IRT for ISR, the rate of TLR was significantly reduced compared to younger patients. However, this reduction in TLR was not associated with a reduction in angiographic restenosis, suggesting that TLR should not be used as a surrogate for angiographic evaluation. Cathet Cardiovasc Intervent 2002;56:466–471. © 2002 Wiley‐Liss, Inc.
Use of an adsorbed chiral selector in capillary LC‐MS
Authors: Törnkvist Anna , Sjöberg Per J.R. , Markides Karin E. , Heldin Eva 
Published: October 2002

AbstractLasalocid was utilized as a chiral selector adsorbed on porous graphitic carbon. Important parameters were identified for the use of the chiral selector in capillary liquid chromatography combined with MS detection. The influence on both retention and enantioselectivity as well as mass spectrometric performance was studied at lasalocid concentrations of up to 12 mg/l (20 μM). Moreover, the stability of retention factors and enantioselectivities was also evaluated at low selector concentration of 1 mg/l (2 μM). The results show that in order to optimize the MS performance the selector concentration should be kept at low μM. The chromatographic performance at reduced selector concentration (1 mg/l = 2 μM) was studied over a 10‐days period, showing satisfactory enantioselectivity and stable performance concerning enantioselectivity and retention. Chirality 14:653–658, 2002. © 2002 Wiley‐Liss, Inc.
Protein phosphorylation regulates actomyosin‐driven vesicle movement in cell extracts isolated from the green algae, Chara corallina
Authors: Morimatsu Miki , Hasegawa Satoshi , Higashi‐Fujime Sugie 
Published: October 2002

AbstractIn Characean cells endoplasmic streaming stops upon membrane depolarization accompanied by Ca2+ entry. We investigated the mechanism of this cessation of endoplasmic streaming by reconstituting the vesicle movement in vitro. In a living cell of Chara corallina, there are a number of vesicles moving along actin cables. Vesicles in the endoplasm squeezed out of the cell into a medium containing Mg‐ATP showed directional movements under a dark field microscope. When the extracted endoplasm was treated with 20 nM okadaic acid, vesicles showed only movements like the Brownian motion. When it was treated with 50 nM staurosporine, directional movements of vesicles were activated. These movements were analyzed by image processing of videomicroscopic records. Vesicle movements along F‐actin filaments were also observed by merging both images of the same field by dark field microscopy and fluorescence microscopy, indicating that myosin on the vesicle surface was responsible for vesicle movements. We also examined the effects of okadaic acid and staurosporine on in vitro sliding of F‐actin on Chara myosin. When Chara myosin was treated with 20 nM okadaic acid in the cell extract, the number of sliding F‐actin filaments was greatly reduced. In contrast, it increased when Chara myosin was treated with 50 nM staurosporine. In addition, Chara myosin treated with protein kinase C greatly diminished its motility. These results suggest that inactivation of Chara myosin via its phosphorylation is responsible for cessation of endoplasmic streaming. Cell Motil. Cytoskeleton 53:66–76, 2002. © 2002 Wiley‐Liss, Inc.
Human osteosarcoma expresses specific ephrin profiles
Authors: Varelias Antiopi , Koblar Simon A. , Cowled Prudence A. , Carter Christopher D. , Clayer Mark 
Published: October 2002

AbstractBACKGROUNDThe molecular mechanisms underlying malignancy of osteosarcoma are unknown. It has been reported that eph receptor protein tyrosine kinases and their ligands, ephrins, are associated with increased tumorigenicity in patients with breast carcinoma and melanoma. The expression and role of eph/ephrins in human osteosarcoma has not yet been characterized.METHODSEphrin‐A1, ephrin‐A3, ephrin‐A4, ephrin‐A5, ephrin‐B1, ephrin‐B2, and ephrin‐B3 mRNA expression was examined by reverse transcription polymerase chain reaction analysis in nine specimens of human osteosarcoma tissue and five human osteosarcoma cell lines. Ephrin‐B1 protein expression was detected immunohistochemically in human osteosarcoma tissue. Clinicopathologic correlation was made between the osteosarcoma specimens and their ephrin expression profiles.RESULTSNormal bone specimens, osteosarcoma tissue specimens, and osteosarcoma cell lines expressed a distinct mRNA profile of ephrin‐A1, ephrin‐A4, and ephrin‐B2. A second mRNA profile that included ephrin‐A3, ephrin‐A5, and ephrin‐B1 was expressed by a subset of tumors. The expression of ephrin‐B1 was correlated with a poorer clinical prognosis. Ephrin‐B1 protein was expressed by osteosarcoma cells and blood vessels.CONCLUSIONSThe results of this study suggest that ephrin‐B1 expressed by osteosarcoma may be a poor prognostic marker through increased tumorigenicity. Cancer 2002;95:862–9. © 2002 American Cancer Society.DOI 10.1002/cncr.10749
Complementary and layered expression of Ephs and ephrins in developing mouse inner ear
Authors: Pickles James O. , Claxton Christina , Van Heumen Walter R.A. 
Published: October 2002

AbstractThe distributions of the Eph‐class receptors EphA4 and EphB1, and their ligands ephrin‐A2, ephrin‐B1, and ephrin‐B2, were analysed by immunostaining in the mouse inner ear. Complementary patterns of EphA4 and its potential ligand ephrin‐A2 were found, with ephrin‐A2 in many of the structures lining the cochlear duct and within the cochlear nerve cells, and EphA4 in the deeper structures underlying the cochlear duct and in the cells lining the nerve pathway. EphB1 and its potential ligands ephrin‐B1 and ephrin‐B2 showed a segregated layered expression in the lateral wall of the cochlear duct (the external sulcus), which together with EphA4 expressed in the area, form a four‐layered structure with an alternating pattern of receptors and ligands in the different layers. This arrangement gives the potential for different bidirectional Eph‐mediated interactions between each of the layers. The results suggest that the Eph system in the cochlea may have a role in maintaining cell segregation during phases of cochlear development. J. Comp. Neurol. 449:207–216, 2002. © 2002 Wiley‐Liss, Inc.