bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aortic and mitral regurgitation: Quantification using moving slice velocity mapping
Authors: Kozerke Sebastian , Schwitter Juerg , Pedersen Erik M. , Boesiger Peter 
Published: August 2002

AbstractComprehensive assessment of the severity of valvular insufficiency includes quantification of regurgitant volumes. Previous methods lack reliable slice positioning with respect to the valve and are prone to velocity offsets due to through‐plane motion of the valvular plane of the heart. Recently, the moving slice velocity mapping technique was proposed. In this study, the technique was applied for quantification of mitral and aortic regurgitation. Time‐efficient navigator‐based respiratory artifact suppression was achieved by implementing a prospective k‐space reordering scheme in conjunction with slice position correction. Twelve patients with aortic insufficiency and three patients with mitral insufficiency were studied. Aortic regurgitant volumes were calculated from diastolic velocities mapped with a moving slice 5 mm distal to the aortic valve annulus. Mitral regurgitant flow was indirectly assessed by measuring mitral inflow at the level of the mitral annulus and net aortic outflow. Regurgitant fractions, derived from velocity data corrected for through‐plane motion, were compared to data without correction for through‐plane motion. In patients with mild and moderate aortic regurgitation, regurgitant fractions differed by 60% and 15%, on average, when comparing corrected and uncorrected data, respectively. Differences in severe aortic regurgitation were less (7%). Due to the large orifice area of the mitral valve, differences were still substantial in moderate‐to‐severe mitral regurgitation (19%). The moving slice velocity mapping technique was successfully applied in patients with aortic and mitral regurgitation. The importance of correction for valvular through‐plane motion is demonstrated. J. Magn. Reson. Imaging 2001;14:106–112. © 2001 Wiley‐Liss, Inc.
Effect of windowing and zero‐filled reconstruction of MRI data on spatial resolution and acquisition strategy
Authors: Bernstein Matt A. , Fain Sean B. , Riederer Stephen J. 
Published: August 2002

AbstractStandard, MR spin‐warp sampling strategies acquire data on a rectangular k‐space grid. That method samples data from the “corners” of k‐space, i.e., data that lie in a region of k‐space outside of an ellipse just inscribed in the rectangular boundary. Illustrative calculations demonstrate that the data in the corners of k‐space contribute to the useful resolution only if an interpolation method such as a zero‐filled reconstruction is used. The consequences of this finding on data acquisition and data windowing strategies are discussed. A further implication of this result is that the spatial resolution of images reconstructed with zero‐filling (but without radial windowing) is expected to display angular dependence, even when the phase‐ and frequency‐encoded resolutions are identical. This hypothesis is experimentally verified with a slit geometry phantom. It is also observed that images reconstructed without zero‐filling do not display the angular dependence of spatial resolution predicted solely by the maximal k‐space extent of the raw data. The implications of these results for 3D contrast‐enhanced angiographic acquisitions with elliptical centric view ordering are explored with simulations. J. Magn. Reson. Imaging 2001;14:270–280. © 2001 Wiley‐Liss, Inc.
Hepatitis C virus infection and genotypes among human immunodeficiency virus high‐risk groups in Cameroon
Authors: Ndjomou Jean , Kupfer Bernd , Kochan Bettina , Zekeng Leopold , Kaptue Lazare , Matz Bertfried 
Published: August 2002

AbstractParenteral transmission of HCV is well established but other possible routes such as heterosexual transmission are still questioned. The Central African region is characterised by a high HCV endemicity without any evidence on the route of transmission. The information on HCV genotypes that circulate in this area is also limited and controversial. HIV infection is very frequent in this region and mostly acquired via the heterosexual route. The aim of this work was to investigate the trend of HCV infection and genotypes among HIV high‐risk groups from Cameroon. Four hundred eighty‐two patients including 229 tuberculosis clinic attendants, 184 sexually transmitted disease clinic attendants, and 69 HIV clinical suspects from another clinic were enrolled. All plasma samples were screened for antibodies to HCV and HCV RNA. Genotypes were assigned by sequencing a 5′UTR amplified fragment. The overall prevalence of HCV markers was 11.6% and a significant increasing trend with respect to age was observed. A proportion of 64.1% (34/53) of HCV antibody positive samples was viraemic. HCV RNA was found in 3 samples that were indeterminate in RIBA 3.0. One was negative in the antibody screening test and the two others were weakly positive. The data on HCV genotypes revealed that genotype 1 was involved in 57% of viraemias, genotype 2 in 24%, while genotypes 4 and 5a accounted for 16 and 3%, respectively. In contrary to the predominance of genotype 4 reported in some African countries and even the neighbouring countries, these data demonstrate clearly that HCV infection in Cameroon is dominated by genotypes 1 and 2. No association was found between the HCV markers and the presence of HIV infection. It is concluded, therefore, that the heterosexual route plays a minor role in HCV transmission in this country. J. Med. Virol. 66:179–186, 2002. © 2002 Wiley‐Liss, Inc.
In vitro antiviral activity of dermaseptins against herpes simplex virus type 1*
Authors: Belaid A. , Aouni M. , Khelifa R. , Trabelsi A. , Jemmali M. , Hani K. 
Published: August 2002

AbstractThe in vitro antiviral activity of dermaseptins (S1–S5) against herpes simplex virus type 1 (HSV1) was investigated. These peptides were incubated with the virus and its target cells under various conditions, and their effects were examined by the cytopathic effect inhibition assay or by reduction in virus yield in Hep‐2 cell cultures as well as by direct immunofluorescence. Dermaseptin S4 displayed the strongest antiviral effect against HSV1, at micromolar doses. Experiments including acyclovir as a reference antiviral agent were performed to investigate the mode of action of this dermaseptin. In contrast to acyclovir, dermaseptin S4 showed its inhibitory effect only when applied to the virus before, or during virus adsorption to the target cells. This suggested that the activity of this dermaseptin was exerted at a very early stage of the viral multiplication cycle, most likely at the virus‐cell interface. J. Med. Virol. 66:229–234, 2002. © 2002 Wiley‐Liss, Inc.
Single rapid TaqMan fluorogenic probe based PCR assay that detects all four dengue serotypes
Authors: Warrilow David , Northill Judith A. , Pyke Alyssa , Smith Greg A. 
Published: August 2002

AbstractPublic health laboratories require rapid diagnosis of dengue outbreaks for application of measures such as vector control. We have developed a rapid single fluorogenic probe‐based polymerase chain reaction assay for the detection of all four dengue serotypes (FUDRT‐PCR). The method employs primers and probe that are complementary to the evolutionarily conserved 3′ untranslated region of the dengue genome. The assay detected viral RNA of strains of all four dengue serotypes but not of the flaviviruses Japanese encephalitis virus, Murray Valley encephalitis virus, Kunjin, Stratford, West Nile, Alfuy or Yellow fever. When compared to an existing nested‐PCR assay for the detection of dengue on clinical samples, FUDRT‐PCR detected dengue 1 (100%, n = 14), dengue 2 (85%, n = 13), dengue 3 (64%, n = 14) and dengue 4 (100%, n = 3) with the indicated sensitivities. FUDRT‐PCR enables diagnosis of acute dengue infection in four hours from sample receipt. In addition, a single‐test procedure should result in a reduction in the number of tests performed with considerable cost savings for diagnostic laboratories. J. Med. Virol. 66:524–528, 2002. © 2002 Wiley‐Liss, Inc.
Molecular evidence of apoptotic death in malignant brain tumors including glioblastoma multiforme: Upregulation of calpain and caspase‐3
Authors: Ray Swapan K. , Patel Sunil J. , Welsh Cynthia T. , Wilford Gloria G. , Hogan Edward L. , Banik Naren L. 
Published: August 2002

AbstractCell death in the core of human brain tumors is triggered by hypoxia and lack of nutrients, but the mode of cell death whether necrosis or apoptosis is not clearly defined. To identify the role of apoptosis in brain tumor cell death, we investigated macromolecular (RNA and protein) synthesis and activity in the central to peripheral region of benign [desmoplastic infantile ganglioglioma (DIG) and transitional meningioma (TMG)] and malignant [ependymoma (END), anaplastic astrocytoma (APA), and glioblastoma multiforme (GBM)] brain tumors derived from five patients who had not received previously radiotherapy or chemotherapy. Normal brain tissue (NBT) served as control. RT‐PCR analysis of tumor tissues covering central to peripheral regions detected mRNA overexpression of pro‐apoptotic gene bax in malignant tumors, indicating a commitment to apoptosis. The mRNA expression of calpain (a Ca2+‐dependent cysteine protease) and calpastatin (endogenous calpain inhibitor) was altered resulting in an elevated calpain/calpastatin ratio. Calpain content and activity were increased, suggesting a role for calpain in cell death. In the mitochondria‐dependent death pathway, caspase‐9 and caspase‐3 were also overexpressed in tumors. The increased caspase‐3 activity cleaved poly(ADP‐ribose) polymerase (PARP). Agarose gel electrophoresis detected a mixture of random and internucleosomal DNA fragmentation in malignant brain tumors. Overexpression of pro‐apoptotic bax, upregulation of calpain and caspase‐3, and occurrence of internucleosomal DNA fragmentation are now presented indicating that one mechanism of cell death in malignant brain tumors is apoptosis, and that enhancement of this process therapeutically may promote decreased tumor growth. © 2002 Wiley‐Liss, Inc.
Systemic administration of antisense p75NTR oligodeoxynucleotides rescues axotomised spinal motor neurons
Authors: Lowry K.S. , Murray S.S. , Coulson E.J. , Epa R. , Bartlett P.F. , Barrett G. , Cheema S.S. 
Published: August 2002

AbstractThe 75 kD low‐affinity neurotrophin receptor (p75NTR) is expressed in developing and axotomised spinal motor neurons. There is now convincing evidence that p75NTR can, under some circumstances, become cytotoxic and promote neuronal cell death. We report here that a single application of antisense p75NTR oligodeoxynucleotides to the proximal nerve stumps of neonatal rats significantly reduces the loss of axotomised motor neurons compared to controls treated with nonsense oligodeoxynucleotides or phosphate‐buffered saline. Our investigations also show that daily systemic intraperitoneal injections of antisense p75NTR oligodeoxynucleotides for 14 days significantly reduce the loss of axotomised motor neurons compared to controls. Furthermore, we found that systemic delivery over a similar period continues to be effective following axotomy when intraperitoneal injections were 1) administered after a delay of 24 hr, 2) limited to the first 7 days, or 3) administered every third day. In addition, p75NTR protein levels were reduced in spinal motor neurons following treatment with antisense p75NTR oligodeoxynucleotides. There were also no obvious side effects associated with antisense p75NTR oligodeoxynucleotide treatments as determined by behavioural observations and postnatal weight gain. Our findings indicate that antisense‐based strategies could be a novel approach for the prevention of motor neuron degeneration associated with injuries or disease. J. Neurosci. Res. 64:11–17, 2001. © 2001 Wiley‐Liss, Inc.
Cobalt chloride induces PC12 cells apoptosis through reactive oxygen species and accompanied by AP‐1 activation
Authors: Zou Weiguo , Yan Mingda , Xu Weijing , Huo Hairong , Sun Lanying , Zheng Zhongcheng , Liu Xinyuan 
Published: August 2002

AbstractReactive oxygen species (ROS) are supposed to play an important role in hypoxia‐ and ischemia/reperfusion‐mediated neuronal injury with the characteristics of apoptosis. There are many reports showing that cobalt chloride (CoCl2) could mimic the hypoxic responses in some aspects including production of ROS in cultured cells. The cytotoxicity of CoCl2 and its molecular mechanisms have yet to be elucidated. We report that CoCl2 triggered neuronal PC12 cells apoptosis in a dose‐ and time‐dependent manner. Apoptosis was demonstrated by morphological changes and DNA fragmentation, and was dependent on macromolecular synthesis. Apoptosis was also confirmed by the decrease of the expression of Bcl‐XL. To our knowledge, this is the first documentation of the apoptotic induction of CoCl2 on PC12 cells. Furthermore, ROS production in PC12 cells was increased during CoCl2 treatment. Antioxidants, which could inhibit ROS production, significantly blocked CoCl2‐induced apoptosis, suggesting that apoptosis is mediated by ROS production. We also observed a significant increase of the DNA‐binding activity of AP‐1 in response to CoCl2 and this increase was blocked by antioxidants, showing that CoCl2‐induced apoptosis is accompanied by ROS‐activated AP‐1. CoCl2‐treated PC12 cells may serve as an in vitro model for studies of molecular mechanisms in ROS‐linked neuronal disorders. J. Neurosci. Res. 64:646–653, 2001. © 2001 Wiley‐Liss, Inc.
Antecedents and consequences of basic versus career enrichment benefit satisfaction
Authors: Blau Gary , Merriman Kimberly , Tatum Donna Surges , Rudmann Sally V. 
Published: August 2002

AbstractUsing a sample of 250 medical technologists (MTs) over a four‐year time period, this study presents initial evidence for differentiating two different facets of benefit satisfaction—basic and career enrichment. Basic benefit satisfaction exhibited stronger relationships to subsequent general benefit satisfaction, organizational withdrawal intent, and turnover behavior, while career enrichment benefit satisfaction exhibited a stronger relationship to subsequent affective organizational commitment. Copyright © 2001 John Wiley & Sons, Ltd.
Snow cover in western Poland and macro‐scale circulation conditions
Authors: Bednorz Ewa 
Published: August 2002

AbstractThe aim of the study was to find out the connection between the nature of winters in the western part of Poland (excluding the Sudety mountains) and the fluctuation in the atmospheric circulation in the North Atlantic region determined by the North Atlantic Oscillation (NAO) index. An attempt was made to establish the correlation between the NAO index and specific meteorological parameters in Poznań. The strongest positive correlation was obtained for the mean winter temperature (December–March) and strong negative correlation was found for the number of days with snow cover. Winter precipitation in Poznań was least associated with the NAO. The correlation coefficient was small and not significant. In the next stage of the study, the area of western Poland was examined; however, only one parameter, i.e. the number of days with snow cover, was taken into consideration. At each of 29 stations distributed in the study area the number of days with snow cover was proved to be strongly negatively correlated with the NAO index. Finally, the frequency of air flow directions was taken into consideration and their association with the NAO was examined. A strong negative correlation was obtained for the frequency of northeasterly and easterly air flow directions and a strong positive correlation was calculated for the frequency of westerly and northwesterly airflow directions. Such findings are consistent with the westerly flow of air masses during the positive phase and with the northerly and easterly flows during the negative phase. The results lead to the conclusion that the positive phase of the NAO causes mild and less snowy winters, whereas the negative phase increases the probability of severe and snowy winters in western Poland. Copyright © 2002 Royal Meteorological Society.
Microstructural interpretations of modern and Pleistocene subglacially deformed sediments: the relative role of parent material and subglacial processes
Authors: Khatwa Anjana , Tulaczyk Slawek 
Published: August 2002

AbstractAnalysis of till micromorphology represents a relatively new technique that has been used most frequently to infer the importance of subglacial shear in till genesis. This study aims to calibrate the technique by comparing Pleistocene tills from United Kingdom with a modern till (the UpB till) from beneath Ice Stream B, West Antarctica. Despite the fact that all of the tills examined have been interpreted as deforming‐bed deposits, the modern till has significantly less abundant and diverse microstructures than those found in the Pleistocene tills. Seventeen examined thin‐sections of the UpB till contain recognisable microstructures over only 0–30% of individual thin‐section area. The most common microstructures are: (i) birefringent clay patterns that are interpreted as shear zones and (ii) adherent matrix structures, which we interpret as uncomminuted remnants of the parent glacial/glaciomarine diamictons. Fourteen thin‐sections of the Pleistocene tills were covered by microstructures in 10–95% of their area. The Pleistocene microstructures include birefringent clays and adherent matrix structures, as in the UpB till, but also laminations and deformed pods made of chalk and sorted sediments. We conclude that the same till‐forming process, i.e. subglacial deformation, may result in distinctly different till micromorphology. This is a consequence of the fact that microstructural characteristics are strongly influenced by factors other than shear deformation. We identify three controls that may be important for forming contrasting microstructural assemblages: (i) strain magnitude, (ii) the degree of heterogeneity of parent material, and (iii) relative importance of sediment sorting by flowing water in the subglacial environment. Thus till micromorphology is sensitive to multiple factors, which with proper calibration may enhance the existing capability to interpret past subglacial conditions from microstructures. Copyright © 2001 John Wiley & Sons, Ltd.
Approaches to improving the bioavailability and level of iron in rice seeds
Authors: Lucca Paola , Hurrell Richard , Potrykus Ingo 
Published: August 2002

AbstractIron deficiency is estimated to affect about 30% of the world population, making iron by far the most deficient nutrient worldwide. Iron supplementation in the form of tablets and food fortification has not been successful in developing countries, and iron deficiency is still the most important deficiency related to malnutrition. Here we present experiments that aim to increase the iron content in rice endosperm and to improve its absorption in the human intestine by means of genetic engineering. We first introduced a ferritin gene from Phaseolus vulgaris into rice grains, increasing their iron content up to twofold. To increase iron bioavailability, we introduced a thermotolerant phytase from Aspergillus fumigatus into the rice endosperm. In addition, as cysteine peptides are considered a major enhancer of iron absorption, we overexpressed the endogenous cysteine‐rich metallothionein‐like protein. The content of cysteine residues increased about sevenfold and the phytase level in the grains about 130‐fold, giving a phytase activity sufficient to completely degrade phytic acid in a simulated digestion experiment. However, the fungal protein did not retain its activity after rice cooking. Therefore a further attempt to specifically reduce the phytic acid in the inner part of the rice endosperm, the tissue eaten after the milling of rice grains, is discussed and biochemical analyses of the transgenic rice seeds are now in progress.© 2001 Society of Chemical Industry
Effects of Botrytis cinerea infection on Champagne wine foaming properties
Authors: Marchal Richard , Tabary Isabelle , Valade Michel , Moncomble Dominique , Viaux Laurence , Robillard Bertrand , Jeandet Philippe 
Published: August 2002

AbstractQualitative effects of Botrytis cinerea infection were studied by comparing the foaming properties of Champagnes obtained from healthy grapes with those from grapes infected by B cinerea. This is of particular interest when it is considered that the foaming properties of Champagne wines are important in terms of product attractiveness for the consumer. Experiments using artificial viewing equipment clearly showed the dramatic effects on Champagne foam characteristics when grape berries were highly infected. The speed at which liquid separated from the foam (expressed as liquid height LS) in the glass depended largely on the level of infection for Chardonnary and Pinot noir wines (+268% for Chardonnary wines at 40% infection and +627% for Pinot noir wines at 20% infection). B cinerea infection reduced the time (LT) at which liquid first appeared in the glass; for Pinot noir wines an infection level of 20% caused very rapid drainage. The time of pouring (PT, ie the time to fill the glass under controlled conditions) also diminished considerably at an infection level of 20% for both Pinot noir and Pinot meunier wines (−74 and −58% respectively). Mouldiness considerably altered the foam height observed 80 s (H80) after the start of pouring (−83% for Pinot noir and −89% for Pinot meunier at 20% infection). Champagne foamability was also quantified using a sparging technique to standardise effervescence. Foamability suffered considerably (−60 to −65%) when the B cinerea infection level was 20% as compared to control Champagnes. All wines studied had low and very similar protein contents. Differences in the concentrations of these compounds, which are generally implicated in the formation of foam in sparkling wines, could not explain the differences in Champagne foaming properties observed here.© 2001 Society of Chemical Industry
Comparison of matrix metalloproteinase expression between primary tumors with or without liver metastasis in pancreatic and colorectal carcinomas
Authors: Matsuyama Yoshito , Takao Sonshin , Aikou Takashi 
Published: August 2002

AbstractBackground and ObjectivesMatrix metalloproteinases (MMPs) are known to play an important role in carcinoma cell invasion and hematogenous metastasis by mediating the degradation of the extracellular matrix.MethodsWe investigated the relationship between MMP‐2 and ‐9 enzymatic activities and liver metastases in human pancreatic and colon carcinomas, using xenograft tumors in nude mice.ResultsWe found that type IV collagenase activity in pancreatic and colon carcinomas with liver metastases was significantly higher than in pancreatic and colon carcinomas without liver metastases. Gelatin zymography showed the presence of gelatinolytic activity bands at Mr 92,000 and 72,000, indicating MMP‐9 and MMP‐2, respectively. MMP‐2 and ‐9 expression levels in pancreatic and colon carcinomas with liver metastases were higher than in pancreatic and colon carcinomas without liver metastases. TIMP‐2 levels in pancreatic and colon carcinomas with liver metastases were also higher than in those without liver metastases.ConclusionsMMP‐2 and MMP‐9 expression in primary tumors is associated with liver metastases in pancreatic and colon carcinomas. In addition, the balance of activity between MMP‐2, MMP‐9, and TIMP‐2 may be relevant to carcinoma invasion and metastasis, including liver metastases in pancreatic and colon carcinoma. J. Surg. Oncol. 2002;80:105–110. © 2002 Wiley‐Liss, Inc.