bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substituent effects on 15N NMR chemical shifts in selected N‐alkylthiohydroxamic acids. A comparative study
Authors: Przychodzeń Witold , Doszczak Leszek , Rachon Janusz 
Published: September 2004

AbstractThe 15N NMR spectra of three N‐alkyl‐δ‐carbomethoxyvalerothiohydroxamic acids (2) and six synthesized N‐isopropylbenzothiohydroxamic acids (3) were measured and compared with appropriate spectra of structurally similar hydroxylamines (1), benzohydroxamic acids (4), benzamides (5) and thiobenzamides (6). The analysis of the chemical shifts of the thiohydroxamic acids under investigation indicates that the inductive effect of the hydroxyl group rather than steric hindrance is responsible for non‐additivity of the effect of substituents. Additionally, N‐hydroxyl diminishes the effect of aromatic ring substituents on the 15N chemical shifts in the thiohydroxamic acids 3 which is approximately half that in the respective thiobenzamides 6. The chemical shift values correlate best with Brown's σ+ parameter. Copyright © 2004 John Wiley & Sons, Ltd.
Proteome analysis of Pseudomonas sp. K82 biodegradation pathways
Authors: Kim Seung Il , Kim Jin Young , Yun Sung‐Ho , Kim Jung‐Hyun , Leem Sun‐Hee , Lee Chulhyun 
Published: September 2004

AbstractPseudomonas sp. K82 is a soil bacterium that can degrade and use monocyclic aromatic compounds including aniline, 3‐methylaniline, 4‐methylaniline, benzoate and p‐hydroxybenzoate as its sole carbon and energy sources. In order to understand the impact of these aromatic compounds on metabolic pathways in Pseudomonas sp. K82, proteomes obtained from cultures exposed to different substrates were displayed by two‐dimensional gel electrophoresis and were compared to search for differentially induced metabolic enzymes. Column separations of active fractions were performed to identify major biodegradation enzymes. More than thirty proteins involved in biodegradation and other types of metabolism were identified by electrospray ionization‐quadrupole time of flight mass spectrometry. The proteome analysis suggested that Pseudomonas sp. K82 has three main metabolic pathways to degrade these aromatic compounds and induces specific metabolic pathways for each compound. The catechol 2,3‐dioxygenase (CD2,3) pathway was the major pathway and the catechol 1,2‐dioxygenase (β‐ketoadipate) pathway was the secondary pathway induced by aniline (aniline analogues) exposure. On the other hand, the catechol 1,2‐dioxygenase pathway was the major pathway induced by benzoate exposure. For the degradation of p‐hydroxybenzoate, the protocatechuate 4,5‐dioxygenase pathway was the major degradation pathway induced. The nuclear magnetic resonance analysis of substrates demonstrated that Pseudomonas sp. K82 metabolizes some aromatic compounds more rapidly than others (benzoate > p‐hydroxybenzoate > aniline) and that when combined, p‐hydroxybenzoate metabolism is repressed by the presence of benzoate or aniline. These results suggest that proteome analysis can be useful in the high throughput study of bacterial metabolic pathways, including that of biodegradation, and that inter‐relationships exist with respect to the metabolic pathways of aromatic compounds in Pseudomonas sp. K82.
Semi‐interpenetrating polymer networks composed of poly(N‐isopropyl acrylamide) and polyacrylamide hydrogels
Authors: Djonlagić Jasna , Petrović Zoran S. 
Published: September 2004

AbstractThree series of semi‐interpenetrating polymer networks, based on crosslinked poly(N‐isopropyl acrylamide) (PNIPA) and 1 wt % nonionic or ionic (cationic and anionic) linear polyacrylamide (PAAm), were synthesized to improve the mechanical properties of PNIPA gels. The effect of the incorporation of linear polymers into responsive networks on the temperature‐induced transition, swelling behavior, and mechanical properties was studied. Polymer networks with four different crosslinking densities were prepared with various molar ratios (25:1 to 100:1) of the monomer (N‐isopropyl acrylamide) to the crosslinker (methylenebisacrylamide). The hydrogels were characterized by the determination of the equilibrium degree of swelling at 25 °C, the compression modulus, and the effective crosslinking density, as well as the ultimate hydrogel properties, such as the tensile strength and elongation at break. The introduction of cationic and anionic linear hydrophilic PAAm into PNIPA networks increased the rate of swelling, whereas the presence of nonionic PAAm diminished it. Transition temperatures were significantly affected by both the crosslinking density and the presence of linear PAAm in the hydrogel networks. Although anionic PAAm had the greatest influence on increasing the transition temperature, the presence of nonionic PAAm caused the highest dimensional change. Semi‐interpenetrating polymer networks reinforced with cationic and nonionic PAAm exhibited higher tensile strengths and elongations at break than PNIPA hydrogels, whereas the presence of anionic PAAm caused a reduction in the mechanical properties. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3987–3999, 2004
The impact of cervical cancer and dysplasia: A qualitative, multiethnic study
Authors: Ashing‐Giwa Kimlin T. , Kagawa‐Singer Marjorie , Padilla Geraldine V. , Tejero Judith S. , Hsiao Evana , Chhabra Rajinder , Martinez Lucrecia , Tucker M. Belinda 
Published: September 2004

AbstractStudy purpose: Cervical cancer (CCA) remains a health challenge nationally and globally. In the US, more than 12 000 women are diagnosed each year with invasive cervical cancer and more than 220 000 are living with a history of this diagnosis (ACS, 2003). This qualitative study aims to examine health related quality of life (HRQOL) from a culturally consistent framework.Methods: Key‐informant interviews (N=23) and focus group interviews (N=51) were conducted with a multiethnic sample of cervical cancer survivors (CCS) recruited from hospitals and clinics.Analyses and results: Content and theme analyses were conducted. Findings indicate that cultural and family factors often promote coping and well‐being, but may foster delay in care seeking and self‐deprecation, particularly among Latina and Asian CCS. Faith in God was relied on for comfort, strength and healing by many survivors, especially the African Americans and Latinas. Overall, our participants reported moderate HRQOL. However, persistent concerns included treatment side‐effects; difficulties accessing quality care; inadequate health insurance, barriers to good physician‐patient relationship such as language and doctors' time constraints; insufficient knowledge about CCA due to limited information from medical staff; lack of control over treatments; social support, family well‐being, functional and work issues; and sexuality and relationship concerns. Socioeconomic status, ethnicity, cultural beliefs and practices, age and family support dictated the level of cancer‐related burden.Conclusion: Invasive CCA is primarily a cancer of women who are economically disenfranchised. Women with a CCA diagnosis are disproportionately challenged by lack of resources including quality, affordable health care and psychosocial services. CCS experience persistent medical, psychological, social, and relational concerns. Information concerning CCS is needed, particularly in Spanish, Vietnamese and Korean. There is an urgent need for further research to understand the risk factors, and the social and cultural mediators of cancer‐related HRQOL for CCS. Copyright © 2004 John Wiley & Sons, Ltd.
The meaning of quality of life in patients being treated for advanced breast cancer: A qualitative study
Authors: Luoma Minna‐Liisa , Hakamies‐Blomqvist Liisa 
Published: September 2004

AbstractThe purpose of the present study was to investigate the meaning of advanced breast cancer patients' quality of life (QoL). A semi‐structured interview was used, and the phenomenological research method chosen to analyse the data.The findings show that limitations in physical functioning translate into dependency on others, leading to decreased autonomy. Patients tended to ensure their autonomy by participating in easier activities or changing their internal standards. Changes in appearance and decreased condition affected patients' ability to carry out roles and responsibilities, which led to changes in lifestyle and also affected patients' social functioning, often resulting in isolation. The meaning of being able to sustain reciprocal relationships was emphasized. Patients maintained control of to what extent their illness was recognized in social relationships, which was crucial to their feelings of autonomy. Close families were a main source of social support, but also a major source of concern. Meaning of emotional functioning was often expressed in terms of the ability to enjoy life day‐by‐day and of commitment to treatment. Patients' cognitive functioning was largely intact while their difficulties in cognitive functioning were more characteristic of anxiety. Global QoL was often expressed in terms of a normal life. In addition there were 3 meta themes which emerged from the data: the patients' ability to control the illness experience, personal growth and hope. Copyright © 2004 John Wiley & Sons, Ltd.
Analysis of data with multiple sources of correlation in the framework of generalized estimating equations
Authors: Shults Justine , Whitt Melicia C. , Kumanyika Shiriki 
Published: September 2004

AbstractThis paper is motivated by a study of physical activity participation habits in African American women with three potential sources of correlation among study outcomes, according to method of assessment, timing of measurement, and intensity of physical activity. To adjust for the multiple sources of correlation in this study, we implement an approach based on generalized estimating equations that models association via a patterned correlation matrix. We present a general algorithm that is relatively straightforward to program, an analysis of our physical activity study, and some asymptotic relative efficiency comparisons between correctly specifying the correlation structure vs ignoring two sources of correlation in the analysis of data from this study. The efficiency comparisons demonstrate that correctly modeling the correlation structure can prevent substantial losses in efficiency in estimation of the regression parameter. Copyright © 2004 John Wiley & Sons, Ltd.
Discrete model of fish scale incremental pattern: a formalization of the 2D anisotropic structure
Authors: Smolyar Igor V. , Bromage Timothy G. 
Published: September 2004

Abstract
The structure of growth patterns on fish scales is characteristically anisotropic: the number of circuli and their widths significantly vary with the direction of measurement. We show, however, that because of anisotropy, fish scale growth rate variability can be described in fuzzy terms. The index of structural anisotropy is introduced, which serves as a measure of the fuzziness of growth-rate quantification. A discrete model of fish scale incremental pattern is proposed, which takes into account the incremental structure in 2D. This model is based on a representation of the fish scale pattern as a relay network, taking anisotropy in the form of discontinuities and convergences of incremental structural elements into account, and the widths of growth increments in different directions. The model is used to formalize procedures necessary for the quantification of fish scale growth rate. The capability of the model for analysing objects with similar structural attributes as found in fish scale incremental patterns, such as those found in coral, otoliths, shells, and bones, is demonstrated.
Daily egg production of anchovy in European waters
Authors: Somarakis Stylianos , Palomera Isabel , Garcia Alberto , Quintanilla Luis , Koutsikopoulos Constantin , Uriarte Andrés , Motos Lorenzo 
Published: September 2004

Abstract
Since the late 1980s, the Daily Egg Production Method (DEPM) has been applied to several anchovy stocks in European waters. DEPM surveys in the Bay of Biscay were well standardized and focused on providing fisheries-independent information for stock assessment purposes. Those targeting Mediterranean stocks were largely experimental and often opportunistic, with the main aim of developing and testing the method, rather than providing estimates of spawning stock biomass (SSB) for stock assessment. Consequently, the DEPM has been applied once, twice, or a maximum of three times in certain Mediterranean areas with no among-area standardization. Different techniques for several aspects of the method have been used in the Mediterranean, and the parameters estimated vary greatly among stocks and year of application. Evidence is provided that variability in biological production among sub-basins and/or years, a characteristic of Mediterranean Sea, may directly affect anchovy egg production. The daily specific fecundity of anchovy stocks can vary greatly among years, areas, or seasons in response to changing environmental and trophic regimes. When the correlation between regression-derived estimates of daily egg production and associated estimates of daily specific fecundity for anchovy in the Mediterranean, the Bay of Biscay, and upwelling areas are compared, a significant isometric relationship emerges for the Mediterranean and the Bay of Biscay, implying density-dependent use of spawning habitat. In upwelling areas, estimates of daily egg production are relatively high for a narrow range of generally low daily specific fecundities. There is a strong linear relationship between anchovy SSB and spawning area in European waters that does not differ significantly between the Bay of Biscay and the Mediterranean Sea.
Persistent HPV infection in postmenopausal age women
Authors: Smith E.M. , Johnson S.R. , Ritchie J.M. , Feddersen D. , Wang D. , Turek L.P. , Haugen T.H. 
Published: September 2004

ABSTRACTObjective: Persistence of human papillomavirus (HPV) is associated with an increased risk of developing cervical SIL and cancer in young women. Because this association in older, postmenopausal age women has received little attention, we evaluated persistence of HPV among women in this age group. Methods:Women (n=105) ages 45–64 were examined annually for 7 years to evaluate HPV in cervical cytologic specimens. PCR, dot blot hybridization and DNA sequencing were used to detect HPV types. Results:The cumulative prevalence of HPV was 34%, and 24% had HPV high‐risk oncogenic types which are associated with genital cancers. The most common oncogenic types were HPV‐16 (72%) and HPV‐31 (16%). The persistence rate of HPV infection was 16%. No specific risk factors were associated with repeat viral positivity. Conclusion:Postmenopausal women are infected with persistent oncogenic HPV at a substantial rate, supporting the need for continued screening in postmenopausal women to detect preneoplastic genital lesions.
Alterations in protein kinase C activity and processing during zinc-deficiency-induced cell death
Authors: CHOU Susan S. , CLEGG Michael S. , MOMMA Tony Y. , NILES Brad J. , DUFFY Jodie Y. , DASTON George P. , KEEN Carl L. 
Published: September 2004

Protein kinases C (PKCs) are a family of serine/threonine kinases that are critical for signal transduction pathways involved in growth, differentiation and cell death. All PKC isoforms have four conserved domains, C1–C4. The C1 domain contains cysteine-rich finger-like motifs, which bind two zinc atoms. The zinc-finger motifs modulate diacylglycerol binding; thus, intracellular zinc concentrations could influence the activity and localization of PKC family members. 3T3 cells were cultured in zinc-deficient or zinc-supplemented medium for up to 32 h. Cells cultured in zinc-deficient medium had decreased zinc content, lowered cytosolic classical PKC activity, increased caspase-3 processing and activity, and reduced cell number. Zinc-deficient cytosols had decreased activity and expression levels of PKC-α, whereas PKC-α phosphorylation was not altered. Inhibition of PKC-α with Gö6976 had no effect on cell number in the zinc-deficient group. Proteolysis of the novel PKC family member, PKC-δ, to its 40-kDa catalytic fragment occurred in cells cultured in the zinc-deficient medium. Occurrence of the PKC-δ fragment in mitochondria was co-incident with caspase-3 activation. Addition of the PKC-δ inhibitor, rottlerin, or zinc to deficient medium reduced or eliminated proteolysis of PKC-δ, activated caspase-3 and restored cell number. Inhibition of caspase-3 processing by Z-DQMD-FMK (Z-Asp-Gln-Met-Asp-fluoromethylketone) did not restore cell number in the zinc-deficient group, but resulted in processing of full-length PKC-δ to a 56-kDa fragment. These results support the concept that intracellular zinc concentrations influence PKC activity and processing, and that zinc-deficiency-induced apoptosis occurs in part through PKC-dependent pathways.
Binding of salivary agglutinin to IgA
Authors: LIGTENBERG Antoon J. M. , BIKKER Floris J. , DE BLIECK-HOGERVORST Jolanda M. A. , VEERMAN Enno C. I. , NIEUW AMERONGEN Arie V. 
Published: September 2004

SAG (salivary agglutinin), which is identical to gp-340 (glycoprotein-340) from the lung, is encoded by DMBT1 (deleted in malignant brain tumours 1). It is a member of the SRCR (scavenger receptor cysteine-rich) superfamily and contains 14 SRCR domains, 13 of which are highly similar. SAG in saliva is partially complexed with IgA, which may be necessary for bacterial binding. The goal of the present study was to characterize the binding of purified SAG to IgA. SAG binds to a variety of proteins, including serum and secretory IgA, alkaline phosphatase-conjugated IgGs originating from rabbit, goat, swine and mouse, and lactoferrin and albumin. Binding of IgA to SAG is calcium dependent and is inhibited by 0.5 M KCl, suggesting that electrostatic interactions are involved. Binding of IgA was destroyed after reduction of SAG, suggesting that the protein moiety is involved in binding. To pinpoint further the binding domain for IgA on SAG, a number of consensus-based peptides of the SRCR domains and SRCR interspersed domains were designed and synthesized. ELISA binding studies with IgA indicated that only one of the peptides tested, comprising amino acids 18–33 (QGRVEVLYRGSWGTVC) of the 109-amino-acid SRCR domain, exhibited binding to IgA. This domain is identical to the domain of SAG that is involved in binding to bacteria. Despite this similar binding site, IgA did not inhibit binding of Streptococcus mutans to SAG or peptide. These results show that the binding of IgA to SAG is specifically mediated by a peptide sequence on the SRCR domains.
Evaluation of angiotensin-converting enzyme (ACE), its homologue ACE2 and neprilysin in angiotensin peptide metabolism
Authors: RICE Gillian I. , THOMAS Daniel A. , GRANT Peter J. , TURNER Anthony J. , HOOPER Nigel M. 
Published: September 2004

In the RAS (renin–angiotensin system), Ang I (angiotensin I) is cleaved by ACE (angiotensin-converting enzyme) to form Ang II (angiotensin II), which has effects on blood pressure, fluid and electrolyte homoeostasis. We have examined the kinetics of angiotensin peptide cleavage by full-length human ACE, the separate N- and C-domains of ACE, the homologue of ACE, ACE2, and NEP (neprilysin). The activity of the enzyme preparations was determined by active-site titrations using competitive tight-binding inhibitors and fluorogenic substrates. Ang I was effectively cleaved by NEP to Ang (1–7) (kcat/Km of 6.2×105 M−1·s−1), but was a poor substrate for ACE2 (kcat/Km of 3.3×104 M−1·s−1). Ang (1–9) was a better substrate for NEP than ACE (kcat/Km of 3.7×105 M−1·s−1 compared with kcat/Km of 6.8×104 M−1·s−1). Ang II was cleaved efficiently by ACE2 to Ang (1–7) (kcat/Km of 2.2×106 M−1·s−1) and was cleaved by NEP (kcat/Km of 2.2×105 M−1·s−1) to several degradation products. In contrast with a previous report, Ang (1–7), like Ang I and Ang (1–9), was cleaved with a similar efficiency by both the N- and C-domains of ACE (kcat/Km of 3.6×105 M−1·s−1 compared with kcat/Km of 3.3×105 M−1·s−1). The two active sites of ACE exhibited negative co-operativity when either Ang I or Ang (1–7) was the substrate. In addition, a range of ACE inhibitors failed to inhibit ACE2. These kinetic data highlight that the flux of peptides through the RAS is complex, with the levels of ACE, ACE2 and NEP dictating whether vasoconstriction or vasodilation will predominate.
A novel retinoic acid-response element requires an enhancer element mediator for transcriptional activation
Authors: HARRIS Laura R. , KAMARAINEN Olli-Pekka , SEVAKIVI Minna , MILLER Gwen C. , CLARKE James W. , POTTER Jennifer L. , BRIDGEWATER Laura C. 
Published: September 2004

The Col11a2 gene codes for α2(XI), a subunit of type XI collagen that is a critical component of the cartilage extracellular matrix. The 5′ regulatory region of Col11a2 was subjected to deletional analysis to detect any regulatory element in addition to the two known chondrocyte-specific enhancer elements B/C and D/E. Deletion of the region from −342 to −242 bp reduced transcriptional activity to less than 50% of wild-type, but the sequence showed no independent ability to increase transcription from a minimal promoter. When cloned downstream of the D/E enhancer, however, a subsection of the sequence nearly doubled transcriptional activity and produced an additional 3-fold activation in response to RA (retinoic acid). A 6-bp direct repeat, separated by 4 bp (a DR-4 element) near the 5′-end of this region, was found to be essential for its activity, and was further shown to bind the RA X receptor β in electrophoretic mobility-shift assays. The present study has revealed a novel RA-response element in Col11a2 that does not interact directly with the promoter, but instead requires the D/E enhancer to mediate transcriptional activation. Proteins bound at the enhancer, therefore, would be expected to affect the transcriptional response to RA. Such a system of regulation, particularly if found to be operating in other cartilage genes, could explain the conflicting responses RA produces in chondrocytes under different experimental conditions.
Tetracycline-regulated expression enables purification and functional analysis of recombinant connexin channels from mammalian cells
Authors: KOREEN Irina V. , ELSAYED Wafaa A. , LIU Yu J. , HARRIS Andrew L. 
Published: September 2004

Intercellular coupling mediated by gap junction channels composed of connexin protein underlies numerous physiological processes, such as cellular differentiation, tissue synchronization and metabolic homoeostasis. The distinct molecular permeability of junctional channels composed of different connexin isoforms allows cellular control of coupling via regulation of isoform expression. However, the permeability properties of most connexin isoforms have not been well characterized due to the difficulty of manipulating and measuring the diffusible concentrations of cytoplasmic messenger molecules and metabolites, and to a lack of control over channel isoform composition, in vivo. Here we present a method to express and purify active connexin hemichannels of a single isoform or a consistent ratio of two isoforms from cultured cells using the Tet-On inducible expression system and one-step anti-haemagglutinin immunoaffinity purification. The procedure yields 10–20 μg of pure connexin protein from 2.5×108 HeLa cells. The purified channels are shown to be useful for in vitro permeability analysis using well established techniques. This method has substantial advantages over existing methods for heterologous connexin expression, such as the ease of co-expression of two isoforms at a constant ratio, consistently high expression levels over many passages, and the ability to study channel properties in situ as well as in purified form. Furthermore, the generic cloning site of the new pBI-GT vector and the commercial availability of anti-haemagglutinin (clone HA-7)–agarose make this affinity tagging and purification procedure easily applicable to other proteins.