bluuebunny/crossref_metadata_2025_split huggingface dataset:
Homozygous SMN1 deletions in unaffected family members and modification of the phenotype by SMN2
Authors: Prior Thomas W. , Swoboda Kathryn J. , Scott H. Denman , Hejmanowski Ashley Q. 
Published: August 2004

AbstractSpinal muscular atrophy is a common autosomal recessive neuromuscular disorder caused by the homozygous loss of the SMN1 gene. The absence of the SMN1 gene has been shown to occur in all types of SMA, childhood and adult forms. In rare cases, asymptomatic family members have also been found with homozygous mutations in the SMN1 gene, suggesting a role for phenotypic modifiers. We describe three unrelated asymptomatic individuals, with family histories of SMA, who were shown to have the homozygous SMN1 deletion. Quantitative studies indicated that the three individuals all had increased SMN2 copy numbers. These cases not only support the role of SMN2 in modifying the phenotype, but our data also demonstrate that expression levels consistent with five copies of the SMN2 genes maybe enough to compensate for the absence of the SMN1 gene. Lastly, in cases similar to the ones described, the measurement of the SMN2 gene copy number may provide valuable prognostic information. © 2004 Wiley‐Liss, Inc.
Genome scan for loci involved in nonsyndromic cleft lip with or without cleft palate in families from West Bengal, India
Authors: Field L. Leigh , Ray Ajit K. , Cooper Margaret E. , Goldstein Toby , Shaw Diana F. , Marazita Mary L. 
Published: August 2004

AbstractIn order to identify genes or regions involved in nonsyndromic cleft lip with or without cleft palate (CL/P) in families from India, we analyzed 38 multiplex families (DNA from 272 individuals, 82 affected with CL/P, 190 unaffected) for 285 genome‐wide markers (average spacing 12.6 cM), including markers in six candidate loci or regions on chromosomes 2, 4, 6, 14, 17, and 19 that have been implicated in other studies of CL/P. LOD scores (two‐point and multipoint), and model‐free association (TDT) and linkage (NPL) statistics, were calculated between each of the markers and a hypothetical CL/P susceptibility locus. The most statistically significant two‐point linkage results were with markers on chromosome 7 (LOD = 1.89 with D7S435, 7p15, 47 cM), chromosome 5 (LOD = 1.76 with D5S407, 5q11, 65 cM), chromosome 15 (LOD = 1.55 with D15S652, 15q26, 90 cM), and chromosome 20 (LOD = 1.46 with STS155130, 20q13, 54 cM). The most significant multipoint linkage result was on chromosome 5q, again near D5S407 (HLOD = 1.40). Regions on chromosomes 1p, 1q, 7q, 12q, 16q, 18q, and Xp also had a LOD or HLOD ≥ 1.0. Of seven candidate markers and regions with previous positive reports in the literature (TGFA, MSX1, D4S175, F13A1, TGFB3, D17S250, and APOC2), none had a significant linkage result, but one (the APOC2 region) had a significant association result and three others (TGFA, MSX1, F13A1) had suggestive results. The results are consistent with the involvement of multiple loci in CL/P expression in this West Bengal population, which concurs with results found in other CL/P study populations. © 2004 Wiley‐Liss, Inc.
Lay people's understanding of and preference against the word “mutation”
Authors: Condit Celeste M. , Dubriwny Tasha , Lynch John , Parrott Roxanne 
Published: August 2004

AbstractLay understandings of the term “mutation” are explored using three methodologies and three population bases. A community based sample (n = 848) employing a written survey to assess knowledge and understanding indicated good lay understanding of the basic concept of mutation. However, lay people associated mutation with reproductive outcomes, but not with changes in genes across the life span. A student sample (n = 241) employed a written survey to assess connotations of the term mutation. It showed a strong negative response to mutation. A community based sample (n = 120) employing focus groups also showed strong negative reactions to the term mutation and rejection of use of the term mutation in public service announcements (PSAs). The term variation had better response and is recommended as an alternative in genetic counseling and public media. © 2004 Wiley‐Liss, Inc.
Control of hepatocyte metabolism by sympathetic and parasympathetic hepatic nerves
Authors: Püschel Gerhard P. 
Published: August 2004

AbstractMore than any other organ, the liver contributes to maintaining metabolic equilibrium of the body, most importantly of glucose homeostasis. It can store or release large quantities of glucose according to changing demands. This homeostasis is controlled by circulating hormones and direct innervation of the liver by autonomous hepatic nerves. Sympathetic hepatic nerves can increase hepatic glucose output; they appear, however, to contribute little to the stimulation of hepatic glucose output under physiological conditions. Parasympathetic hepatic nerves potentiate the insulin‐dependent hepatic glucose extraction when a portal glucose sensor detects prandial glucose delivery from the gut. In addition, they might coordinate the hepatic and extrahepatic glucose utilization to prevent hypoglycemia and, at the same time, warrant efficient disposal of excess glucose. © 2004 Wiley‐Liss, Inc.
Innervation of immune cells: Evidence for neuroimmunomodulation in the liver
Authors: Neuhuber Winfried L. , Tiegs Gisa 
Published: August 2004

AbstractRecent studies have demonstrated a pronounced influence by the autonomic nervous system on immune‐mediated experimental hepatitis in the mouse. Adrenergic sympathetic neurons alleviate while capsaicin‐sensitive peptidergic primary afferent neurons aggravate liver injury. This was evidenced by recording morphological and functional parameters upon chemical sympathectomy and application of β‐adrenergic agonists, and capsaicin depletion of afferents, neurokinin receptor antagonists, and application of exogenous substance P, respectively. These phenomena are most likely based on close anatomical relationships between nerve fibers and various immune cells in the liver. Modulation of autonomic nervous system functions may open novel therapeutic strategies in immune and inflammatory liver diseases. © 2004 Wiley‐Liss, Inc.
Prognose der Dauerhaftigkeit mineralischer Außenputze mit Hilfe von beschleunigten Alterungstests
Authors: Bochen Jerzy , Nowak Henryk A. 
Published: August 2004

AbstractDer Beitrag stellt eine Methode für beschleunigte Alterungstests von verschiedenen Putzen vor. Für die Beschreibung der Dauerhaftigkeit wurden zwei Modelle entwickelt. Die Modelle beschreiben Veränderungen ausgewählter Eigenschaften, die infolge von Frostschäden und Auslaugung auftreten. Das erste Modell basiert auf der Veränderung der Masse und das zweite auf der Veränderung der Festigkeit. In den Modellen werden die wesentlichen Eigenschaften berücksichtigt, die die Dauerhaftigkeit beeinflussen, wie z. B. Festigkeit, Porosität, Dichtigkeit, Haftzugfestigkeit und agressive Umwelteinwirkungen. Beide Modelle ermöglichen die Prognose der Dauerhaftigkeit von Außenputzen.
Der sommerliche Wärmeschutz eines sanierten Wohngebäudes aus den 1950er Jahren unter Berücksichtigung des Nutzerverhaltens
Authors: Hoffmann Sabine , Geyer Christoph , Kornadt Oliver 
Published: August 2004

AbstractIn der voraussichtlich ab Herbst 2004 in Kraft tretenden Änderungsnovelle der Energieeinsparverordnung wird in Zukunft der Nachweis des sommerlichen Wärmeschutzes nach DIN 4108‐2: 2003‐7 gefordert, wodurch sich die Anforderungen an den sommerlichen Wärmeschutz von Wohngebäuden ändern. Am Beispiel eines sanierten Mehrfamilienhauses aus den 1950er Jahren werden die Auswirkungen untersucht, die sich auf die baulichen Anforderungen und das sich im Wohnraum einstellende Innenklima ergeben. Probleme des zusätzlichen Heizwärmebedarfs werden dabei ebenso berücksichtigt wie die Tageslichtverhältnisse im Raum. In einer thermischen Gebäudesimulation mit ESP‐r werden für verschiedene Nutzungsarten das Lüftungsverhalten und die sich ergebenden Überhitzungszeiten diskutiert.
Schallschutz mit schalldämmenden Lüftungsgittern
Authors: Eßer Georg , Sälzer Elmar 
Published: August 2004

AbstractSchalldämmende Lüftungsgitter werden bei Zu‐ oder Abluftöffnungen von Gebäuden, bei natürlich belüfteten Parkhäusern und zum Sichtschutz an lärmemittierenden Anlagen, bei denen gleichzeitig für die Luftführung die Luftdurchströmung sichergestellt werden muß, benötigt. Im Labor wurden die Schalldämmungen von verschiedenen Lüftungsgittern meßtechnisch untersucht. Für typische Lüftungsgitter wurde ein Nomogramm in Abhängigkeit von der Spaltlänge und ‐breite entwickelt, um das bewertete Schalldämm‐Maß von schalldämmenden Lüftungsgittern prognostizieren zu können. Abschließend werden Anhaltswerte für die heranzuziehenden Spektrum‐Anpassungswerte in Bezug auf die bewerteten Schalldämm‐ Maße genannt.
Dose‐response for retinoic acid‐induced forelimb malformations and cleft palate: A comparison of computerized image analysis and visual inspection
Authors: Campbell Jerry L. , Smith Mary Alice , Fisher Jeffrey W. , Warren D. Alan 
Published: August 2004

AbstractBACKGROUND: The objectives of this study were to (1) compare two techniques (computerized image analysis and visual morphological evaluation) for the assessment of fetal forelimb malformations and (2) increase the robustness of the dose‐response curve for forelimb and cleft palate malformations resulting from all‐trans retinoic acid (RA) exposure in GD 11 mice. METHODS: Pregnant CD‐1 mice were administered a single oral dose of all‐trans RA (0, 2.5, 10, 30, 60, or 100 mg/kg) on GD 11. GD 18 fetuses were examined for malformations using visual morphological scoring and computerized image analysis. RESULTS: Dose‐dependent changes occurred in the size and shape of the humerus, radius, and ulna based on both assessment methodologies. The most sensitive indicators for the lowest effect level (10 mg/kg) on forelimbs were roundness, a shape measurement determined by image analysis, and visual morphological scoring. For all other bone measurements (proximal and distal width, area, length, and perimeter), the lowest effect level was 30 mg/kg. The maximum effect for limb defects and total malformed fetuses was seen at 60 mg/kg and higher. Incidence of cleft palate increased over the entire range of administered doses reaching a maximum of 74% (100 mg/kg). CONCLUSIONS: Overall, results indicate that computerized image analysis was no more sensitive in detecting changes in the humerus, radius, and ulna than gross visual examination. Dose‐response modeling of developmental endpoints yielded comparable benchmark dose levels for long bones and cleft palate that ranged from 0.24 to 7.6 mg/kg all‐trans RA. Birth Defects Res B 71:289–295, 2004. © 2004 Wiley‐Liss, Inc.
Protein engineering of toluene 4‐monooxygenase of Pseudomonas mendocina KR1 for synthesizing 4‐nitrocatechol from nitrobenzene
Authors: Fishman Ayelet , Tao Ying , Bentley William E. , Wood Thomas K. 
Published: August 2004

AbstractAfter discovering that toluene 4‐monooxygenase (T4MO) of Pseudomonas mendocina KR1 oxidizes nitrobenzene to 4‐nitrocatechol, albeit at a very low rate, this reaction was improved using directed evolution and saturation mutagenesis. Screening 550 colonies from a random mutagenesis library generated by error‐prone PCR of tmoAB using Escherichia coli TG1/pBS(Kan)T4MO on agar plates containing nitrobenzene led to the discovery of nitrocatechol‐producing mutants. One mutant, NB1, contained six amino acid substitutions (TmoA Y22N, I84Y, S95T, I100S, S400C; TmoB D79N). It was believed that position I100 of the α subunit of the hydroxylase (TmoA) is the most significant for the change in substrate reactivity due to previous results in our lab with a similar enzyme, toluene ortho‐monooxygenase of Burkholderia cepacia G4. Saturation mutagenesis at this position resulted in the generation of two more nitrocatechol mutants, I100A and I100S; the rate of 4‐nitrocatechol formation by I100A was more than 16 times higher than that of wild‐type T4MO at 200 μM nitrobenzene (0.13 ± 0.01 vs. 0.008 ± 0.001 nmol/min·mg protein). HPLC and mass spectrometry analysis revealed that variants NB1, I100A, and I100S produce 4‐nitrocatechol via m‐nitrophenol, while the wild‐type produces primarily p‐nitrophenol and negligible amounts of nitrocatechol. Relative to wild‐type T4MO, whole cells expressing variant I100A convert nitrobenzene into m‐nitrophenol with a Vmax of 0.61 ± 0.037 vs. 0.16 ± 0.071 nmol/min·mg protein and convert m‐nitrophenol into nitrocatechol with a Vmax of 3.93 ± 0.26 vs. 0.58 ± 0.033 nmol/min·mg protein. Hence, the regiospecificity of nitrobenzene oxidation was changed by the random mutagenesis, and this led to a significant increase in 4‐nitrocatechol production. The regiospecificity of toluene oxidation was also altered, and all of the mutants produced 20% m‐cresol and 80% p‐cresol, while the wild‐type produces 96% p‐cresol. Interestingly, the rate of toluene oxidation (the natural substrate of the enzyme) by I100A was also higher by 65% (7.2 ± 1.2 vs. 4.4 ± 0.3 nmol/min mg protein). Homology‐based modeling of TmoA suggests reducing the size of the side chain of I100 leads to an increase in the width of the active site channel, which facilitates access of substrates and promotes more flexible orientations. © 2004 Wiley Periodicals, Inc.
Kinetic resolution of (R,S)‐sec‐butylamine using omega‐transaminase from Vibrio fluvialis JS17 under reduced pressure
Authors: Yun Hyungdon , Cho Byung‐Kwan , Kim Byung‐Gee 
Published: August 2004

AbstractThe kinetic resolution of (R,S) sec‐butylamine with the ω‐transaminase (TA) from Vibrio fluvialis JS17 was performed under reduced pressure (e.g., 150 torr) to selectively remove an inhibitory product (2‐butanone). The evaporation kinetics of 2‐butanone at 150 torr in the buffer solution followed the first‐order rate law, and the evaporation rate constant was 2.19 1/h, and independent of pH, while the evaporation kinetics of sec‐butylamine is dependent on pH. A simple mathematical model of the evaporation of sec‐butylamine allowing the estimation of its concentration in the reaction media was developed. The evaporation rate constant of its free amine form and the protonated amine form were 1.00 1/h, and nearly zero, respectively. Although the optimum pH of the ω‐TA activity for sec‐butylamine is 9.0, the optimal pH of the enzyme reaction under reduced pressure was pH 7.0, due to the higher evaporation rate of sec‐butylamine at higher pH above 7.0. Using the recombinant Escherichia coli BL21 overexpressing ω‐TA, 400 mM racemic sec‐butylamine was resolved successfully to 98% ee of (R)‐sec‐butylamine with 53% conversion at 150 torr and pH 7.0. © 2004 Wiley Periodicals, Inc.
Accelerating whole‐cell biocatalysis by reducing outer membrane permeability barrier
Authors: Ni Ye , Chen Rachel R. 
Published: August 2004

AbstractWhole‐cell biocatalysts are preferred in many biocatalysis applications. However, due to permeability barriers imposed by cell envelopes, whole‐cell catalyzed reactions are reportedly 10–100‐fold slower than reactions catalyzed by free enzymes. In this study, we accelerated whole‐cell biocatalysis by reducing the membrane permeability barrier using molecular engineering approaches. Escherichia coli cells with genetically altered outer membrane structures were used. Specifically, a lipopolysaccarides mutant SM101 and a Braun's lipoprotein mutant E609L were used along with two model substrates that differ substantially in size and hydrophobicity, nitrocefin, and a tetrapeptide N‐succinyl‐Ala‐Ala‐Pro‐Phe‐p‐nitroanilide. The reduction of the outer membrane permeability by genetic methods led to significant increases (up to 380%) in reaction rates of whole‐cell catalyzed reactions. The magnitude of increase in biocatalysis rates was dependent on the substrates and on the nature of mutations introduced in the outer membrane structure. Notably, mutations in outer membrane can render the outer membrane completely permeable to one substrate, a barrierless condition that maximizes the reaction rate. The impact of the mutations introduced on the permeability barrier of the membranes was compared to the impact of polymixin B nonapeptide, a known potent permeabilizer acting on lipopolysaccharides. Our results suggest that genetic modifications to enhance the permeability of hydrophilic molecules should target the Lipid A region. However, strategies other than reduction of Lipid A synthesis should be considered. As we have demonstrated with tetrapeptide, membrane engineering can be much more effective in reducing a permeability barrier than are exogenous permeabilizers. This work, to our knowledge, is the first use of a molecular membrane engineering approach to address substrate permeability limitations encountered in biocatalysis applications. © 2004 Wiley Periodicals, Inc.
Photosynthetically oxygenated salicylate biodegradation in a continuous stirred tank photobioreactor
Authors: Muñoz Raul , Köllner Claudia , Guieysse Benoit , Mattiasson Bo 
Published: August 2004

AbstractA consortium consisting of a Chlorella sorokiniana strain and a Ralstonia basilensis strain was able to carry out sodium salicylate biodegradation in a continuous stirred tank reactor (CSTR) using exclusively photosynthetic oxygenation. Salicylate biodegradation depended on algal activity, which itself was a function of microalgal concentration, light intensity, and temperature. Biomass recirculation improved the photobioreactor performance by up to 44% but the results showed the existence of an optimal biomass concentration above which dark respiration started to occur and the process efficiency started to decline. The salicylate removal efficiency increased by a factor of 3 when illumination was increased from 50–300 μE/m2·s. In addition, the removal rate of sodium salicylate was shown to be temperature‐dependent, increasing from 14 to 27 mg/l·h when the temperature was raised from 26.5 to 31.5°C. Under optimized conditions (300 μE/m2·s, 30°C, 1 g sodium salicylate/l in the feed and biomass recirculation) sodium salicylate was removed at a maximum constant rate of 87 mg/l·h, corresponding to an estimated oxygenation capacity of 77 mg O2/l·h (based on a BOD value of 0.88 g O2/g sodium salicylate for the tested bacterium), which is in the range of the oxygen transfer capacity of large‐scale mechanical surface aerators. Thus, although higher degradation rates were attained in the control reactor, the photobioreactor is a cost‐efficient process which reduces the cost of aeration and prevents volatilization problems associated with the degradation of toxic volatile organic compounds under aerobic conditions. © 2004 Wiley Periodicals, Inc.
Bioprocess‐centered molecular design (BMD) for the efficient production of an interfacially active peptide
Authors: Morreale Giacomo , Gyo Lee Eun , Jones Daniel B. , Middelberg Anton P.J. 
Published: August 2004

AbstractThe efficient expression and purification of an interfacially active peptide (mLac21) was achieved by using bioprocess‐centered molecular design (BMD), wherein key bioprocess considerations are addressed during the initial molecular biology work. The 21 amino acid mLac21 peptide sequence is derived from the lac repressor protein and is shown to have high affinity for the oil–water interface, causing a substantial reduction in interfacial tension following adsorption. The DNA coding for the peptide sequence was cloned into a modified pET‐31(b) vector to permit the expression of mLac21 as a fusion to ketosteroid isomerase (KSI). Rational iterative molecular design, taking into account the need for a scaleable bioprocess flowsheet, led to a simple and efficient bioprocess yielding mLac21 at 86% purity following ion exchange chromatography (and >98% following chromatographic polishing). This case study demonstrates that it is possible to produce acceptably pure peptide for potential commodity applications using common scaleable bioprocess unit operations. Moreover, it is shown that BMD is a powerful strategy that can be deployed to reduce bioseparation complexity. © 2004 Wiley Periodicals, Inc.
NAD‐sensitive hydrogel for the release of macromolecules
Authors: Tang M. , Zhang R. , Bowyer A. , Eisenthal R. , Hubble J. 
Published: August 2004

AbstractA hydrogel membrane containing immobilized ligands and receptors was synthesized and investigated for the controlled diffusion of test proteins (cytochrome C and hemoglobin). Both Cibacron blue (ligand) and lysozyme (receptor) were covalently linked to dextran molecules that were subsequently crosslinked to form a gel. The resulting stable hydrogels contained both covalent and affinity crosslinks such that their intrinsic porosities were sensitive to competitive displacers of the affinity interaction between lysozyme and Cibacron blue. Transport experiments in a twin chamber diffusion cell showed that as NAD was added to the donor side, the dissociation of the binding sites between the Cibacron blue and the lysozyme led to an increase in protein diffusion through the hydrogel. The results showed that addition of NAD caused a saturable concentration‐dependent increase in the transport of both cytochrome C and hemoglobin. This effect was shown to be both specific and reversible. © 2004 Wiley Periodicals, Inc.
Stimulation of growth factor synthesis in skin wounds using tissue extract (G‐90) from the earthworm Eissenia foetida
Authors: Grdiša M. , Popović M. , Hrženjak T. 
Published: August 2004

AbstractGrowth factors are biologically‐active mediators that bind to specific receptors on target cells and regulate genes involved in cell growth, wound healing and regeneration. In the case of wound healing, a proper wound dressing is needed to cover the wound area, protect the damaged tissue, and if possible to activate cell proliferation and stimulate the healing process. In this study we examined the efficacy of a glycolipoprotein tissue homogenate extract from Eisenia foetida (G‐90) to activate signal transduction pathways, leading to wound healing. We measured the activation of EGF and FGF in healthy skin, in wounds with physiological healing and in wounds treated with G‐90. The activation of EGF and FGF was measured during the first 24 h of wound healing under both physiological conditions and treatment with G‐90. In both cases an increased concentration of EGF and FGF was observed 6 h after wounding. In comparison with healthy skin, the concentration of EGF increased 10‐fold and FGF five‐fold in wounds treated with G‐90 (10 ng ml−1). Healing in physiological conditions resulted in a two‐fold increase of EGF and 1.5‐fold of FGF. Copyright © 2004 John Wiley & Sons, Ltd.