bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of Immobilized Lipase on Hydrophobic Superparamagnetic Microspheres To Catalyze Esterification
Authors: Guo Zheng , Sun Yan 
Published: April 2004

AbstractA novel immobilized lipase (from Candida rugosa) on hydrophobic and superparamagnetic microspheres was prepared and used as a biocatalyst to catalyze esterification reactions in diverse solvents and reaction systems. The results showed that the immobilized lipase had over 2‐fold higher activities in higher log P value solvents. An exponential increase of lipase activity against log P of two miscible solvent mixtures was observed for the first time. Both free and immobilized lipase achieved its maximum activity at the range of water activity ( aw) 0.5–0.8 or higher. At aw 0.6, the immobilized lipase exhibited markedly higher activities in heptane and a solvent‐free system than did the native lipase. In multicompetitive reactions, the alcohol specificity of the lipase showed a strong chain‐length dependency, and the immobilized enzyme exhibited more preference for a longer‐chain alcohol, which is different from previous reports. The immobilized lipase showed higher specificities for butyric acid and the medium‐chain‐length fatty acids (C8–C12). Then, the immobilized lipase was extended to solvent‐free synthesis of glycerides from glycerol and fatty acids. Recovered by magnetic separation, the immobilized lipase exhibited good reusability in repeated batch reaction, indicating its promising feature for biotechnology application.
Purification and Characterization of a Novel Mannitol Dehydrogenase from Lactobacillus intermedius
Authors: Saha Badal C. 
Published: April 2004

AbstractMannitol 2‐dehydrogenase (MDH) catalyzes the pyridine nucleotide dependent reduction of fructose to mannitol. Lactobacillus intermedius(NRRL B‐3693), a heterofermentative lactic acid bacterium (LAB), was found to be an excellent producer of mannitol. The MDH from this bacterium was purified from the cell extract to homogeneity by DEAE Bio‐Gel column chromatography, gel filtration on Bio‐Gel A‐0.5m gel, octyl‐Sepharose hydrophobic interaction chromatography, and Bio‐Gel Hydroxyapatite HTP column chromatography. The purified enzyme (specific activity, 331 U/mg protein) was a heterotetrameric protein with a native molecular weight (MW) of about 170 000 and subunit MWs of 43 000 and 34 500. The isoelectric point of the enzyme was at pH 4.7. Both subunits had the same N‐terminal amino acid sequence. The optimum temperature for the reductive action of the purified MDH was at 35 °C with 44% activity at 50 °C and only 15% activity at 60 °C. The enzyme was optimally active at pH 5.5 with 50% activity at pH 6.5 and only 35% activity at pH 5.0 for reduction of fructose. The optimum pH for the oxidation of mannitol to fructose was 7.0. The purified enzyme was quite stable at pH 4.5–8.0 and temperature up to 35 °C. The Km and Vmax values of the enzyme for the reduction of fructose to mannitol were 20 mM and 396 μmol/min/mg protein, respectively. It did not have any reductive activity on glucose, xylose, and arabinose. The activity of the enzyme on fructose was 4.27 times greater with NADPH than NADH as cofactor. This is the first highly NADPH‐dependent MDH (EC 1.1.1.138) from a LAB. Comparative properties of the enzyme with other microbial MDHs are presented.
Purification, Immobilization, and Stabilization of a Lipase from Bacillus thermocatenulatus by Interfacial Adsorption on Hydrophobic Supports
Authors: Palomo J. M. , Segura R. L. , Fernández‐Lorente G. , Pernas M. , Rua M. L. , Guisán J. M. , Fernández‐Lafuente R. 
Published: April 2004

AbstractA lipase from Bacillus thermocatenulatus (BTL2) cloned in E. coli has been purified using a very simple method: interfacial activation on a hydrophobic support followed by desorption with Triton. Only one band was detected by SDS‐PAGE. The pure enzyme was immobilized using different methodologies. BTL2 adsorbed on a hydrophobic support (octadecyl‐Sepabeads) exhibited a hyperactivation with respect to the soluble enzyme, whereas the other immobilized preparations suffered a slight decrease in the expressed activity. The soluble enzyme was very stable, but all immobilized preparations were much more stable than the soluble enzyme, the octadecyl‐Sepabeads‐BTL2 preparation being the most stable one in all conditions (high temperature or in the presence of organic cosolvents), maintaining 100% of the activity at 65 °C or 30% of dioxane and 45 °C after several days of incubation. The glyoxyl preparation, the second more stable, retained 80% of the initial activity after 2 days, respectively. The adsorption of this thermophilic lipase on octadecyl‐Sepabeads permitted an increase in the optimal temperature of the enzyme of 10 °C.
Differential growth rates of the cerebellum and posterior fossa assessed by post mortem magnetic resonance imaging of the fetus: implications for the pathogenesis of the chiari 2 deformity
Authors: Griffiths P. D. , Wilkinson I. D. , Variend S. , Jones A. , Paley M. N. J. , Whitby E. 
Published: April 2004

Purpose: To evaluate post mortem magnetic resonance imaging of the fetus to provide data on the rate of growth of the cerebellum, bony posterior fossa, supratentorial bony compartment and cerebrum. Material and Methods: Twenty fetuses subsequently shown to have normal brain and spines on autopsy were studied using MRI post mortem. MRI from 20 normal pediatric brain examinations in children aged 6 years or younger were studied for comparison. Post mortem MRI was performed using a high‐resolution fast spin echo technique providing T2 weighted images. The area of the cerebellar vermis, posterior fossa, supratentorial skull cavity and cerebral hemispheres was measured in the sagittal plane in all cases. These measurements were compared over the age ranges studied. Results: We have shown that there are differences in the rate of growth and the apparent commencement of growth between the structures under study. The cerebellum appeared to start its significant growth at 16.5 weeks with a rate of 16 mm2/week throughout pregnancy, while the cerebral hemisphere appeared to commence significant growth at 13 weeks at a rate of 184 mm2/week throughout pregnancy. This is in contrast to the bony posterior fossa, whose growth paralleled the supratentorial bony compartment at all ages studied. Conclusion: We interpret our findings as showing relatively late commencement of cerebellar growth compared to the cerebral hemispheres, whereas the growth of the bony posterior fossa appears to be in advance and independent of cerebellar growth. Our results support the hypothesis that posterior fossa development depends on raised hydrostatic pressure in the CSF containing structures of the posterior fossa. When this mechanism fails, as in some cases of myelomeningocoele, a small posterior fossa is formed which characterizes the Chiari 2 malformation.
Computer‐assisted detection as a second reader in symptomatic asian women with palpable breast cancer
Authors: Chu W. C. W. , Lam W. W. M. , Pang A. L. M. , So N. M. C. , Tang A. P. Y. , Tse G. M. K. , Ahuja A. T. 
Published: April 2004

Purpose: To determine the potential role of a computer‐assisted detection (CAD) algorithm as a second reader for experienced and inexperienced radiologists in mammography reading in Asian women. Material and Methods: Two‐view mammograms performed in 124 consecutive patients who presented with palpable breast cancer masses were retrospectively evaluated by two experienced breast radiologists (7 and 10 years' experience). The original reports of the session radiologists with variable experience of reading mammograms (2 to more than 10 years) were also evaluated. The number of suspicious masses and microcalcification clusters detected in each patient by both groups of radiologists were recorded. The radiologists then re‐evaluated the films with the CAD system as a second reader. Any improvement in the detectability of breast pathology by either the experienced radiologists and/or by the session radiologists was then assessed. A total of 127 breasts had biopsy‐proven carcinoma; 74 breasts had mastectomy performed. All the imaging results were correlated with tru‐cut biopsy or mastectomy histology. Results: With CAD‐aided interpretation, there were altogether 95 visible masses and 77 suspicious microcalcification clusters in 109 mammographically detectable cancers correlated with histology results. There was a 7.4% (7/95) and 10.4% (8/77) increase in the number of masses and microcalcification clusters detected, respectively, by the experienced radiologists after application of CAD, whereas the increase was 13.7% (13/95) and 27.3% (21/77) for detection of masses and microcalcifications by the session radiologists, respectively. In 9 patients, a secondary focus detected by CAD was confirmed by histology. Three patients had contralateral breast tumors, 1 had a satellite invasive tumor while 5 had ductal carcinoma in situ on the same breast. Based on the biopsies and 74 mastectomies, the true‐positive and false‐positive detection rate of CAD was 92.6% and 31.8% for detection of carcinomas. The true‐positive and false‐positive detection rates were 100% and 58.8% for microcalcification clusters. Conclusion: The current generation CAD algorithm helped to improve the detection rate of carcinomas, calcifications and multifocality in Asian breasts.
Postnatal nicotine exposure does not further compromise hypoxia defense mechanisms in prenatally nicotine‐exposed lambs
Authors: Hafström O , Milerad J , Sundell HW 
Published: April 2004

Aims: To determine whether combined pre‐ and postnatal nicotine exposure compared with prenatal exposure alone results in more compromised postnatal hypoxia defense mechanisms and further alteration of the postnatal breathing pattern (reduced tidal volume and increased respiratory rate). Methods: Seven lambs exposed to nicotine prenatally (pN) (approximate maternal dose: 0.5 mg/kg/d) and seven lambs exposed to nicotine pre‐ and postnatally (ppN) (postnatal dose: 1.6–2 mg/kg/d) were studied without sedation at an average age of 5 d and 21 d during resting (room air) conditions, during exposure to 10% O2 and during a brief exposure to 100% O2. Results: Resting minute ventilation, occlusion pressure, effective impedance, heart rate and mean arterial blood pressure were similar in the two groups during wakefulness and quiet sleep. Resting tidal volume was significantly higher in ppN than in pN lambs during wakefulness (9.4 ±; 0.7 vs 7.7 ±; 1.4 ml/kg, p > 0.05) and quiet sleep (9.8 ±; 0.6 vs 7.6 ±; 1.5 ml/kg, p > 0.01) at 5 d and also at 21 d during wakefulness (7.7 ±; 1.0 vs 6.2 ±; 1.1 ml/kg, p > 0.05). The ventilatory, heart rate and blood pressure responses to hypoxia were comparable in the two groups during both activity states. Time to arousal from quiet sleep in response to hypoxia was equivalent in the two groups. The ventilatory response to hyperoxia was not significantly different in the two groups during either activity state.Conclusion: Continued postnatal nicotine exposure after prenatal exposure did not further compromise hypoxia defense mechanisms after birth.
Burst suppression on amplitude‐integrated electroencephalogram may be induced by midazolam: a report on three cases
Authors: ter Horst HJ , Brouwer OF , Bos AF 
Published: April 2004

Continuous amplitude‐integrated electroencephalogram (aEEG) recording with a cerebral function monitor is a useful tool to evaluate prognoses following perinatal asphyxia in term infants. Drugs may change the pattern of the conventional EEG. This report presents three infants treated with midazolam for status epilepticus and repetitive seizures who proved resistant to other anticonvulsants (phenobarbitone, lidocaine). The infants developed burst suppression patterns on aEEG concurrent with high serum levels of midazolam (900‐7093 μg l‐1). Following discontinuation of midazolam treatment, serum levels normalized and background patterns returned to normal voltage traces.Conclusion: These findings indicated that midazolam can cause burst suppression on aEEG. Therefore, the prognostic value of aEEG is limited in case of high serum levels of midazolam. Serum levels of midazolam should be measured in infants who have burst suppression patterns on aEEG during midazolam treatment.
Preterm male infants need more initial respiratory and circulatory support than female infants
Authors: Elsmén E , Pupp I Hansen , Hellström‐Westas L 
Published: April 2004

Aim: The aim of this study was to investigate possible gender‐related differences in clinical parameters during the first week of life that could explain the higher morbidity and mortality of preterm male infants. Methods: In total, 130 clinical variables were collected from 236 inborn infants (130 male and 106 female infants) with gestational age (GA) >29wk. A subgroup of 175 extremely low birthweight infants (ELBW) >1000 g (n= 86 males; n= 89 females) was analysed separately. Results: At 6 postnatal h, 60.8% of the male infants needed mechanical ventilation versus 46.2% of the females (p= 0.026). Chronic lung disease (CLD) developed in 36.2% of males versus 9.8% of female infants (p= 0.004). Inotrope support with dopamine was used in more than 50% of the infants; additional inotrope support to dopamine was needed by 19.4% of male and 9.7% of female infants (p= 0.041). The gender‐related difference in need for inotrope support was more evident among the ELBW infants; 67.1% of male infants needed inotrope support versus 50.6% of females (p= 0.028). At 12–24 h, male ELBW infants had lower minimum mean arterial blood pressure (mean (SD) 25(4) mmHg vs 28(6) mmHg, p= 0.004)) and lower minimum PaCO2 than females infants (4.3 (1.1) kPa vs 4.7 (0.9) kPa, p= 0.043).Conclusions: There are early gender‐related differences in need for ventilatory and circulatory support that may contribute to the worse long‐term outcome in prematurely born male infants.
Immediate and short‐term effects of pulmonary artery banding on left ventricular performance in foetal sheep
Authors: Sonesson S‐E , Fouron J‐C , Teyssier G , Skoll A , Chartrand C 
Published: April 2004

Aim: To evaluate foetal left ventricular performance when its preload was increased by banding the pulmonary artery, a study design where a simultaneous change in left ventricular afterload is unlikely. Methods: Nine ovine foetuses were studied with real‐time images and Doppler echocardiography before, 3–4 and 6–8 d after surgery. Seven of these foetuses were also studied during the surgical intervention, immediately before and within 2 min after banding. Results: The immediate effects of a 90‐95% reduction of the pulmonary artery cross‐sectional area were: a 53 ±; 20% (mean ±; SD) decrease and a 38 ±; 10% increase of right (RvQ) and left ventricular output (LvQ), respectively. Comparing measurements before and 3–4 d after operation, there was a 64 ±; 16% decrease of RvQ and a 64 ±; 25% increase of LvQ. The increase in LvQ was due to an increase in both heart rate (19 ±; 10%) and stroke volume (38 ±; 18%). After an additional 3–4 postoperative days, heart rate remained increased to the same extent, but there was a more pronounced increase of LvQ (93 ±; 19%) and stroke volume (59 ±; 22%).Conclusion: The parallel foetal circulation has a capacity to handle a severely increased afterload for the right ventricle by immediately improving and maintaining an increased left ventricular performance. This improvement was in part accomplished by an increase in stroke volume.
Electron Tomographic Analysis of Somatic Cell Plate Formation in Meristematic Cells of Arabidopsis Preserved by High-Pressure Freezing[W]
Authors: Seguié-Simarro Joseé M. , Austin Jotham R. , White Erin A. , Staehelin L. Andrew 
Published: April 2004

AbstractWe have investigated the process of somatic-type cytokinesis in Arabidopsis (Arabidopsis thaliana) meristem cells with a three-dimensional resolution of ∼7 nm by electron tomography of high-pressure frozen/freeze-substituted samples. Our data demonstrate that this process can be divided into four phases: phragmoplast initials, solid phragmoplast, transitional phragmoplast, and ring-shaped phragmoplast. Phragmoplast initials arise from clusters of polar microtubules (MTs) during late anaphase. At their equatorial planes, cell plate assembly sites are formed, consisting of a filamentous ribosome-excluding cell plate assembly matrix (CPAM) and Golgi-derived vesicles. The CPAM, which is found only around growing cell plate regions, is suggested to be responsible for regulating cell plate growth. Virtually all phragmoplast MTs terminate inside the CPAM. This association directs vesicles to the CPAM and thereby to the growing cell plate. Cell plate formation within the CPAM appears to be initiated by the tethering of vesicles by exocyst-like complexes. After vesicle fusion, hourglass-shaped vesicle intermediates are stretched to dumbbells by a mechanism that appears to involve the expansion of dynamin-like springs. This stretching process reduces vesicle volume by ∼50%. At the same time, the lateral expansion of the phragmoplast initials and their CPAMs gives rise to the solid phragmoplast. Later arriving vesicles begin to fuse to the bulbous ends of the dumbbells, giving rise to the tubulo-vesicular membrane network (TVN). During the transitional phragmoplast stage, the CPAM and MTs disassemble and then reform in a peripheral ring phragmoplast configuration. This creates the centrifugally expanding peripheral cell plate growth zone, which leads to cell plate fusion with the cell wall. Simultaneously, the central TVN begins to mature into a tubular network, and ultimately into a planar fenestrated sheet (PFS), through the removal of membrane via clathrin-coated vesicles and by callose synthesis. Small secondary CPAMs with attached MTs arise de novo over remaining large fenestrae to focus local growth to these regions. When all of the fenestrae are closed, the new cell wall is complete. Few endoplasmic reticulum (ER) membranes are seen associated with the phragmoplast initials and with the TVN cell plate that is formed within the solid phragmoplast. ER progressively accumulates thereafter, reaching a maximum during the late PFS stage, when most cell plate growth is completed.
Composition and Structure of the Centromeric Region of Rice Chromosome 8[W]
Authors: Wu Jianzhong , Yamagata Harumi , Hayashi-Tsugane Mika , Hijishita Saori , Fujisawa Masaki , Shibata Michie , Ito Yukiyo , Nakamura Mari , Sakaguchi Miyuki , Yoshihara Rie , Kobayashi Harumi , Ito Kazue , Karasawa Wataru , Yamamoto Mayu , Saji Shoko , Katagiri Satoshi , Kanamori Hiroyuki , Namiki Nobukazu , Katayose Yuichi , Matsumoto Takashi , Sasaki Takuji 
Published: April 2004

AbstractUnderstanding the organization of eukaryotic centromeres has both fundamental and applied importance because of their roles in chromosome segregation, karyotypic stability, and artificial chromosome-based cloning and expression vectors. Using clone-by-clone sequencing methodology, we obtained the complete genomic sequence of the centromeric region of rice (Oryza sativa) chromosome 8. Analysis of 1.97 Mb of contiguous nucleotide sequence revealed three large clusters of CentO satellite repeats (68.5 kb of 155-bp repeats) and &gt;220 transposable element (TE)–related sequences; together, these account for ∼60% of this centromeric region. The 155-bp repeats were tandemly arrayed head to tail within the clusters, which had different orientations and were interrupted by TE-related sequences. The individual 155-bp CentO satellite repeats showed frequent transitions and transversions at eight nucleotide positions. The 40 TE elements with highly conserved sequences were mostly gypsy-type retrotransposons. Furthermore, 48 genes, showing high BLAST homology to known proteins or to rice full-length cDNAs, were predicted within the region; some were close to the CentO clusters. We then performed a genome-wide survey of the sequences and organization of CentO and RIRE7 families. Our study provides the complete sequence of a centromeric region from either plants or animals and likely will provide insight into the evolutionary and functional analysis of plant centromeres.
An oral cancer information leaflet for smokers in primary care: results from two randomised controlled trials
Authors: Humphris G. M. , Field E. A. 
Published: April 2004

Abstract  – Objectives:  To investigate whether primary care patients who claim to smoke tobacco gain greater benefit of a patient information leaflet (PIL) on oral cancer than nonsmokers.Methods:  Two studies were conducted. Study 1 examined the research question initially, and Study 2 acted as a replication and inclusion of additional secondary outcome measures. The leaflet was designed and tested in an earlier study. Knowledge of oral cancer was assessed by a previously validated 36‐dichotomous‐item scale. A single‐item question ascertained self‐reported smoking status (kappa = 0.94). Study 1 participants were drawn from 14 practices (6 medical, 8 dental). A randomised control group design was adopted. The experimental group received the leaflet on attendance to the practice and then completed the questionnaire. The control group received the questionnaire only. Complete data were collected from 739 respondents. The design of Study 2 was identical; 786 new respondents from 16 practices (7 medical, 9 dental) were collected.Results:  Both studies confirmed that smokers knew less about oral cancer than nonsmokers (P < 0.05) when access to the leaflet had been denied. On receipt of the leaflet, there was no distinction in oral cancer knowledge between the smoking status categories of respondents. Evidence of reassurance about screening from leaflet exposure was supported by the second study.Conclusion:  This programmed research has demonstrated an effect of a brief PIL to offset the decrement in oral cancer knowledge observed in primary care patients who use tobacco in comparison to their nonsmoking counterparts. The leaflet reduced anxiety about oral health screening in smokers.
Demographic factors, denture status and oral health‐related quality of life
Authors: John Mike T. , Koepsell Thomas D. , Hujoel Philippe , Miglioretti Diana L. , LeResche Linda , Micheelis Wolfgang 
Published: April 2004

Abstract  – Objectives:  This study investigated the association between denture status, demographic factors, and oral health‐related quality of life (OHRQoL).Methods:  OHRQoL was measured using the German version of the Oral Health Impact Profile (OHIP‐G, 53 items), which was administered in a personal interview to 2050 subjects (60% of eligible subjects responded) 16–79 years of age in a national survey. Median regression was used to analyze the influence of denture status (no, removable, complete dentures), age, gender, education (less than 10 years of schooling, 10–12 years, more than 12 years), and residential area (rural, urban) on the OHIP‐G summary score.Results:  In bivariable analyses, compared to the base category, the OHIP‐G median increased 8.0 U for subjects with removable dentures, 20.0 U for subjects with complete dentures, 1.7 U for each 10‐year age period, 2.0 U for men, 3.0 U for less than 10 years of schooling (compared to ≥10 years.), and 1.0 U for urban areas (P < 0.05 for all effects except for residential area). In the multivariable analysis, compared to subjects without dentures, subjects with removable dentures had a 7.5 (95% CI: 5.2–9.8) higher OHIP‐G median and subjects with complete dentures had a 18.5 (95% CI: 14.7–22.4) higher median when demographic variables were controlled. No demographic variables were statistically significant except for residential area (P = 0.04).Conclusions:  Denture status was a stronger predictor for impaired OHRQoL than demographic variables and rendered age and education almost negligible in their influence on OHRQoL.