bluuebunny/crossref_metadata_2025_split huggingface dataset:
From Wolff's law to the Utah paradigm: Insights about bone physiology and its clinical applications
Authors: Frost Harold M. 
Published: August 2002

AbstractEfforts to understand our anatomy and physiology can involve four often overlapping phases. We studywhatoccurs, thenhow, then askwhy, and then seekclinical applications. In that regard, in 1960 views, bone's effector cells (osteoblasts and osteoclasts) worked chiefly to maintain homeostasis under the control of nonmechanical agents, and that physiology had little to do with anatomy, biomechanics, tissue‐level things, muscle, and other clinical applications. But it seems later‐discovered tissue‐level mechanisms and functions (including biomechanical ones, plus muscle) are the true key players in bone physiology, and homeostasis ranks below the mechanical functions. Adding that information to earlier views led to the Utah paradigm of skeletal physiology that combines varied anatomical, clinical, pathological, and basic science evidence and ideas. While it explains in a general way how strong muscles make strong bones and chronically weak muscles make weak ones, and while many anatomists know about the physiology that fact depends on, poor interdisciplinary communication left people in many other specialties unaware of it and its applications. Those applications concern 1.) healing of fractures, osteotomies, and arthrodeses; 2.) criteria that distinguish mechanically competent from incompetent bones; 3.) design criteria that should let load‐bearing implants endure; 4.) how to increase bone strength during growth, and how to maintain it afterwards on earth and in microgravity situations in space; 5.) how and why healthy women only lose bone next to marrow during menopause; 6.) why normal bone functions can cause osteopenias; 7.) why whole‐bone strength and bone health are different matters; 8.) why falls can cause metaphyseal and diaphyseal fractures of the radius in children, but mainly metaphyseal fractures of that bone in aged adults; 9.) which methods could best evaluate whole‐bone strength, “osteopenias” and “osteoporoses”; 10.) and why most “osteoporoses” should not have bone‐genetic causes and some could have extraosseous genetic causes. Clinical specialties that currently require this information include orthopaedics, endocrinology, radiology, rheumatology, pediatrics, neurology, nutrition, dentistry, and physical, space and sports medicine. Basic science specialties include absorptiometry, anatomy, anthropology, biochemistry, biomechanics, biophysics, genetics, histology, pathology, pharmacology, and cell and molecular biology. This article reviews our present general understanding of this new bone physiology and some of its clinical applications and implications. It must leave to other times, places, and people the resolution of questions about that new physiology, and to understand the many devils that should lie in its details. (Thompson D'Arcy,1917). Anat Rec 262:398–419, 2001. © 2001 Wiley‐Liss, Inc.
Expression of extracellular matrix metalloproteinase inducer and enhancement of the production of matrix metalloproteinases in rheumatoid arthritis
Authors: Tomita Tetsuya , Nakase Takanobu , Kaneko Motoharu , Shi Kenrin , Takahi Koichiro , Ochi Takahiro , Yoshikawa Hideki 
Published: August 2002

AbstractObjectiveTo investigate the expression of extracellular matrix metalloproteinase inducer (EMMPRIN) at sites of joint destruction in rheumatoid arthritis (RA) and to correlate it with the production of matrix metalloproteinases (MMPs).MethodsReverse transcription‐polymerase chain reaction was performed to study the existence of EMMPRIN in synovial tissue derived from RA and osteoarthritis (OA) patients. In situ hybridization with a human complementary DNA specific for EMMPRIN and immunohistochemistry were performed to characterize the EMMPRIN‐expressing cells at sites of joint destruction, including bone. Northern blot analysis was performed to detect the level of expression of EMMPRIN messenger RNA (mRNA) in synovial tissue. The production of MMP‐1 and MMP‐3 by synovial tissue from RA patients was examined by enzyme‐linked immunosorbent assay.ResultsExpression of EMMPRIN mRNA was detected in synovium from 9 of 11 patients with RA and 1 of 5 patients with OA. The presence of mRNA encoding EMMPRIN was recognized in the invasive synovium at sites of joint destruction in RA but not OA. Fibroblast‐like synovial cells and granulocytes were demonstrated to express EMMPRIN mRNA. MMP‐1 and MMP‐3 production by synovial tissue was correlated with levels of expression of EMMPRIN mRNA, as detected by Northern blotting.ConclusionThe expression of EMMPRIN stimulates the production of MMP‐1 and MMP‐3 in the synovial tissue of affected joints in RA. The results of this study suggest that EMMPRIN may be one of the important factors in progressive joint destruction in RA.
Declines in strength and balance in older adults with chronic knee pain: A 30‐month longitudinal, observational study
Authors: Messier Stephen P. , Glasser Julie L. , Ettinger Walter H. , Craven Timothy E. , Miller Michael E. 
Published: August 2002

AbstractObjectivesTo document changes in lower extremity strength and balance over a 30‐month period in older adults with chronic knee pain, and to identify relationships among these variables that may prove useful in designing a subsequent clinical intervention trial.MethodsThis longitudinal, 30‐month, observational study was designed to examine the association of physical, psychological, social, and environmental factors with severity and progression of physical disability caused by chronic knee pain. This article will focus on 2 physical measures: strength and dynamic balance. The participants were a cohort of 480 adults 65 years of age or older with chronic knee pain. Measurements included: 1) force platform dynamic balance measure of the center of pressure excursion during a forward and subsequent backward lean, 2) isokinetic strength measures of concentric and eccentric knee flexion and extension, and concentric ankle plantar flexion and dorsiflexion, and 3) body mass index and a knee pain scale to measure obesity and knee pain, respectively.ResultsA maximum‐likelihood analysis revealed an overall significant decline in knee (P< 0.001) and ankle (P= 0.012) strength, and balance (P< 0.001) after a 30‐month followup period. Participants with greater knee strength at baseline had less expected decline in balance at followup than their weaker counterparts (4.2% versus 7.7% for the 75th versus 25th percentiles of strength;P= 0.023). However, the absolute decline in balance over 30 months was similar regardless of baseline ankle strength.ConclusionsAdults age ≥65 years with chronic knee pain experience significant declines in balance and lower extremity strength over a 30‐month period. Moreover, greater knee and ankle muscular strength is associated with better balance. Previous studies have shown that weight training is effective in improving balance in older adults with knee osteoarthritis. Taken together, these studies present a strong rationale for incorporating weight training into an exercise prescription for older adults with chronic knee pain.
Believe it or not: Factors influencing credibility on the Web
Authors: Wathen C. Nadine , Burkell Jacquelyn 
Published: August 2002

AbstractThis article reviews selected literature related to the credibility of information, including (1) the general markers of credibility, and how different source, message and receiver characteristics affect people's perceptions of information; (2) the impact of information medium on the assessment of credibility; and (3) the assessment of credibility in the context of information presented on the Internet. The objective of the literature review is to synthesize the current state of knowledge in this area, develop new ways to think about how people interact with information presented via the Internet, and suggest next steps for research and practical applications. The review examines empirical evidence, key reviews, and descriptive material related to credibility in general, and in terms of on‐line media. A general discussion of credibility and persuasion and a description of recent work on the credibility and persuasiveness of computer‐based applications is presented. Finally, the article synthesizes what we have learned from various fields, and proposes a model as a framework for much‐needed future research in this area.
Stochastic modeling of usage patterns in a web‐based information system
Authors: Chen Hui‐Min , Cooper Michael D. 
Published: August 2002

AbstractUsers move from one state (or task) to another in an information system's labyrinth as they try to accomplish their work, and the amount of time they spend in each state varies. This article uses continuous‐time stochastic models, mainly based on semi‐Markov chains, to derive user state transition patterns (both in rates and in probabilities) in a Web‐based information system. The methodology was demonstrated with 126,925 search sessions drawn from the transaction logs of the University of California's MELVYL® library catalog system (www.melvyl.ucop.edu). First, user sessions were categorized into six groups based on their similar use of the system. Second, by using a three‐layer hierarchical taxonomy of the system Web pages, user sessions in each usage group were transformed into a sequence of states. All the usage groups but one have third‐order sequential dependency in state transitions. The sole exception has fourth‐order sequential dependency. The transition rates as well as transition probabilities of the semi‐Markov model provide a background for interpreting user behavior probabilistically, at various levels of detail. Finally, the differences in derived usage patterns between usage groups were tested statistically. The test results showed that different groups have distinct patterns of system use. Knowledge of the extent of sequential dependency is beneficial because it allows one to predict a user's next move in a search space based on the past moves that have been made. It can also be used to help customize the design of the user interface to the system to facilitate interaction. The group CL6 labeled “knowledgeable and sophisticated usage” and the group CL7 labeled “unsophisticated usage” both had third‐order sequential dependency and had the same most‐frequently occurring search pattern: screen display, record display, screen display, and record display. The group CL8 called “highly interactive use with good search results” had fourth‐order sequential dependency, and its most frequently occurring pattern was the same as CL6 and CL7 with one more screen display action added. The group CL13, called “known‐item searching” had third‐order sequential dependency, and its most frequently occurring pattern was index access, search with retrievals, screen display, and record display. Group CL14 called “help intensive searching,” and CL18 called “relatively unsuccessful” both had third‐order sequential dependency, and for both groups the most frequently occurring pattern was index access, search without retrievals, index access, and again, search without retrievals.
Volatility analysis during the Asia crisis: a multivariate GARCH‐M model for stock returns in the U.S., Germany and Japan
Authors: Polasek Wolfgang , Ren Lei 
Published: August 2002

AbstractThe Asia crisis in the summer of 1997 triggered a negative shock to the world economy. But when did it hit the major stock markets? In this paper we analyse the daily stock returns in the U.S., Germany and Japan for a period of 2 years (June 21st, 1996 to June 22nd, 1998). We estimate a VAR‐GARCH in mean model to investigate the multivariate volatility effects between the time series. We are also interested in the question of whether or not the volatility of the 3 stock returns will feed back on the returns themselves. Using the marginal likelihood criterion for model selection of the stock returns we find a VAR(1)‐GARCH(2,2)‐M (1) model. The model is estimated using MCMC methods and the coefficients show quite a rich transmission pattern between the stock markets. Comparing the models before and after the Asia crisis we see that the dynamic structure of the VAR model has changed. Copyright © 2001 John Wiley & Sons, Ltd.
Estimation in integer‐valued moving average models
Authors: Brännäs Kurt , Hall Andreia 
Published: August 2002

AbstractThe paper presents new characterizations of the integer‐valued moving average model. For four model variants, we give moments and probability generating functions. Yule–Walker and conditional least‐squares estimators are obtained and studied by Monte Carlo simulation. A new generalized method of moment estimator based on probability generating functions is presented and shown to be consistent and asymptotically normal. The small sample performance is in some instances better than those of alternative estimators. Copyright © 2001 John Wiley & Sons, Ltd.
The corticostriatal junction: A crucial region for forebrain development and evolution
Authors: Molnár Zoltán , Butler Ann B. 
Published: August 2002

AbstractMost parts of the brain are conserved across reptiles and birds (sauropsids) and mammals. Two major qualitative differences occur in the upper part, or pallium, of the telencephalon, the most rostral part of the brain. Mammals have a six‐layered neocortex and also exhibit a different morphological organization in the lateral half, or sector, of their pallium than do sauropsids. These differences of lateral pallial construction may derive from small but crucial differences in migration patterns of neuronal precursors generated at or above the corner of the lateral ventricle, the corticostriatal junction (CS). Sauropsids have a large structure, the dorsal ventricular ridge, that is proliferated from this region, and its anterior part (ADVR) receives ascending projections from the dorsal thalamus. Mammals have multiple structures in this same region—the lateral part of neocortex, amygdala, and claustrum‐endopiriform formation. We propose here that, as the degree of development of structures that form the deeper tier of the pallium varies across the stages of embryology and across phylogeny, mutations may have occurred during evolution at the origin of mammals that had profound consequences for the fate of neural populations generated in the region of the CS and its neighboring pallial germinal zone. BioEssays 24:530–541, 2002. © 2002 Wiley Periodicals, Inc.
Enzymatic degradation of carboxymethyl cellulose hydrolyzed by the endoglucanases Cel5A, Cel7B, and Cel45A from Humicola insolens and Cel7B, Cel12A and Cel45Acore from Trichoderma reesei
Authors: Karlsson Johan , Momcilovic Dane , Wittgren Bengt , Schülein Martin , Tjerneld Folke , Brinkmalm Gunnar 
Published: August 2002

AbstractEnzymatic hydrolysis of carboxymethyl cellulose (CMC) has been studied with purified endoglucanases Hi Cel5A (EG II), Hi Cel7B (EG I), and Hi Cel45A (EG V) from Humicola insolens, and Tr Cel7B (EG I), Tr Cel12A (EG III), and Tr Cel45Acore (EG V) from Trichoderma reesei. The CMC, with a degree of substitution (DS) of 0.7, was hydrolyzed with a single enzyme until no further hydrolysis was observed. The hydrolysates were analyzed for production of substituted and non‐substituted oligosaccharides with size exclusion chromatography (SEC) and with matrix‐assisted laser desorption/ionization mass spectrometry (MALDI‐TOF‐MS). Production of reducing ends and of nonsubstituted oligosaccharides was determined as well. The two most effective endoglucanases for CMC hydrolysis were Hi Cel5A and Tr Cel7B. These enzymes degraded CMC to lower molar mass fragments compared with the other endoglucanases. The products had the highest DS determined by MALDI‐TOF‐MS. Thus, Hi Cel5A and Tr Cel7B were less inhibited by the substituents than the other endoglucanases. The endoglucanase with clearly the lowest activity on CMC was Tr Cel45Acore. It produced less than half of the amount of reducing ends compared to Tr Cel7B; furthermore, the products had significantly lower DS. By MALDI‐TOF‐MS, oligosaccharides with different degree of polymerization (DP) and with different number of substituents could be separated and identified. The average oligosaccharide DS as function of DP could be measured for each enzyme after hydrolysis. The combination of techniques for analysis of product formation gave information on average length of unsubstituted blocks of CMC. © 2002 John Wiley & Sons, Inc. Biopolymers 63: 32–40, 2002
Protein unfolding during reversed‐phase chromatography: II. Role of salt type and ionic strength
Authors: McNay Jennifer L. M. , O'Connell John P. , Fernandez Erik J. 
Published: August 2002

AbstractWhile reversed‐phase chromatography (RPC) may be a powerful method for purification of proteins at the analytical scale, both preparative and analytical applications have been hindered by the complex chromatographic behavior of proteins compared to small molecules. Further, preparative applications have been limited because of poor yields caused by the denaturing conditions involved. One means for modulating both the stability and chromatographic behavior of proteins is through the use of added salt. In this investigation, we show how salt type and ionic strength affect protein conformation on RPC surfaces. Exposure of amide groups of adsorbed BPTI was monitored using nuclear magnetic resonance (NMR) spectroscopy and hydrogen–deuterium isotope exchange. Sodium chloride, sodium acetate, and ammonium sulfate were studied at ionic strengths up to I = 0.375, with adsorption hold times being 5 min and 2 h. We found that increasing ionic strength decreased exposure of the exchange reporter groups in essentially all cases. However, even at the same ionic strength the level and distribution of residue protection varied with salt type and hold time. NaCl does not protect certain reporter groups at all, while those that it does protect to some degree at short hold times can exchange slightly more at longer times. The pattern and level of protection for NaAc at short times is similar to that for NaCl, but at longer times more uniform protection is seen as the reporter groups completely exposed at short times become more protected. For (NH4)2SO4 the pattern of protection at short hold time is similar to those of the other salts, although it protects all groups much more. This would be expected from the Hofmeister series. However, at longer times the level of protection with (NH4)2SO4 decreases below that of the other salts, while it uniquely protects all groups to nearly the same level. Such subtle variations in the protein structure would not have been detected without the measurements and analysis used here. Chromatographic retention times and peak shapes were obtained for the above systems. Variations of behavior were seen that could not be correlated with any of the above protection patterns and levels or even with heuristics such as the Hofmeister series. This suggests further conformational changes upon elution may be critical to the retention process. However, an excellent correlation was found between peak width at half‐height and the average degree of unfolding, as indicated by the average level of isotopic exchange. Thus, while further studies are needed to definitively determine the connection between protein unfolding and retention, use of this correlation may improve designing and screening for chromatographic conditions that minimize protein unfolding. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 76: 233–240, 2001.
Metabolic control of recombinant monoclonal antibody N‐glycosylation in GS‐NS0 cells
Authors: Hills Anna E. , Patel Ashvin , Boyd Paul , James David C. 
Published: August 2002

AbstractVariable N‐glycosylation at Asn297 in the Fc region of recombinant therapeutic immunoglobulin G (IgG) molecules, specifically terminal galactosylation and sialylation, may affect both pharmacokinetic behavior and effector functions of recombinant therapeutic antibodies. We investigated the hypothesis that IgG Fc glycosylation can be controlled by manipulation of cellular nucleotide‐sugar metabolism. In control cultures, N‐glycans associated with the Fc domain of a recombinant humanized IgG1 produced by GS‐NS0 cells in culture were predominantly biantennary, variably β‐galactosylated (average 0.3 mol galactose complex N‐glycan−1) structures with no bisecting N‐acetylglucosamine residues, sialylation, or α1,3‐linked galactosylation evident. However, a variable proportion (5% to 15%) of high‐mannose (Man5 to Man9) oligosaccharides were present. To manipulate the cellular content of the nucleotide sugar precursor required for galactosylation, UDP‐Gal, we included either 10 mM glucosamine or 10 mM galactose in the culture medium. In the case of the former, a 17‐fold increase in cellular UDP‐N‐acetylhexosamine content was observed, with a concomitant reduction (33%) in total UDP‐hexose, although the ratio of UDP‐Glc:UDP‐Gal (4:1) was unchanged. Associated with these alterations in cellular UDP‐sugar content was a significant reduction (57%) in the galactosylation of Fc‐derived oligosaccharides. The proportion of high‐mannose‐type N‐glycans (specifically Man5, the substrate for N‐acetylglucosaminyltransferase I) at Asn297 was unaffected. In contrast, inclusion of 10 mM galactose in culture specifically stimulated UDP‐Gal content almost five‐fold. However, this resulted in only a minimal, insignificant increase (6%) in β1,4‐galactosylation of Fc N‐glycans. Sialylation was not improved upon the addition of the CMP–sialic acid (CMP‐SA) precursor N‐acetylmannosamine (20 mM), even with an associated 44‐fold increase in cellular CMP‐SA content. Analysis of recombinant IgG1 Fc glycosylation during batch culture showed that β1,4‐linked galactosylation declined slightly during culture, although, in the latter stages of culture, the release of proteases and glycosidases by lysed cells were likely to have contributed to the more dramatic drop in galactosylation. These data demonstrate: (i) the effect of steric hindrance on Fc N‐glycan processing; (ii) the extent to which alterations in cellular nucleotide‐sugar content may affect Fc N‐glycan processing; and (iii) the potential for direct metabolic control of Fc N‐glycosylation. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 239–251, 2001.