bluuebunny/crossref_metadata_2025 huggingface dataset:
Investigation into the exploitation of Object-Oriented features
Authors: Kanmani S. , Uthariaraj V. Rhymend , Sankaranarayanan V. , Thambidurai P.
Published: July 2004

This paper discusses the results arrived at employing Object-Oriented (OO) measures on the small-sized programs developed by the Under Graduate (UG) students during the study of C++ laboratory course. The metric values computed reflect the experience/knowledge of the developer in various mechanisms (inheritance, coupling and cohesion) in developing the modules (classes). We propose six hypotheses to validate the measures. For this experiment, the number of attributes and number of methods defined in the class are correlated with the metric values. The result of the experiment shows that the programs used inheritance and cohesion properties appropriately in the design of the class level attributes.
Some research on componentware frameworks based on mobile agent technology
Authors: Lu Jian
Published: July 2004

With the development of mobile agent technology and the applications of componentware, the requirements for a new componentware framework based on mobile agent technology are increasing. These requirements include requirements from programming methodology, requirements from componentware, and requirements from mobile agent technology. According to these requirements and after analyzing the limitations of "traditional" component software, this paper presents some ideas about what the mobile agent technology can do to overcome these limitations. Then based on the above analysis and the mobile agent technology, this paper proposes three new conceptual componentware frameworks. They include an adjustable componentware framework, a smart componentware framwork, and a flexible framework. These new frameworks provides much more flexibility than the traditional componentware frameworks and more suitable to the open environment of Internet. In order to support previously proposed new conceptual componentware frameworks based on mobile agent technology, some issues about the infrastructure, methodology and technical challenge are also discussed in this paper. Our goal is to build a new componentware framework based on mobile agent technology, overcome the limitations of the current approaches, and further popularize the Internet by giving people greater access to it with less effort.
Dealing with architectural issues
Authors: Terekhov Andrey A.
Published: July 2004

This paper describes an effort to recover and improve software architecture in a large-scale industrial project. We describe our motivation for architecture recovery and present a summary of its results. We also attempt to generalize our findings by arguing that the current level of understanding of software architecture is not sufficient to determine in advance which factors will be important (i.e., "architectural") for a software product in the long term.
Product family testing
Authors: Tevanlinna Antti , Taina Juha , Kauppinen Raine
Published: July 2004

In this paper we discuss the current state of product family testing. Testing, unlike other areas of software development, has received only little attention in this context despite the problems directly rising from scale, reuse and variability. We present the current approaches to product family testing methodology and processes. We also evaluate the current state-of-the-art in product family testing and highlight problems that need to be addressed in the future.
6th ICSE Workshop on Component-Based Software Engineering
Authors: Crnkovic Ivica , Schmidt Heinz , Stafford Judith , Wallnau Kurt
Published: July 2004

This report gives an overview of the 6th ICSE Workshop on Component-Based Software Engineering held at 25
th
International Conference on Software Engineering. The workshop brought together researchers and practitioners from three communities: component technology, software architecture, and software certification. The primary goal of the workshop was to continue clarifying the concepts, identifying the main challenges and findings of predictable assembly of certifiable software components. This report gives a comprehensive summary of the position papers, of the workshop, its findings, and its results.
An approach to modelling and applying mobile agent design patterns
Authors: Lima Emerson F. A. , Machado Patrícia D. L. , Sampaio Fláavio R. , Figueiredo Jorge C. A.
Published: July 2004

Mobile agent design patterns represent solutions to specific problems of implementing mobile agent-based applications that have evolved over time. The use of design patterns can increase productivity, promote reuse and reduce complexity when developing applications. However, most of the mobile agent design patterns presented in the literature are difficult to apply in practice due to the lack of a suitable approach to identify, document and apply them. Also, they are usually related to a specific mobile agent platform. We present an approach for modelling and applying patterns independently of specific platforms along with their counterparts in specific platforms. Also, we show that an adequate platform independent view can be constructed to be used as a guide to implement the pattern in different platforms.
A study to investigate the impact of requirements instability on software defects
Authors: Javed Talha , Maqsood Manzil e , Durrani Qaiser S.
Published: July 2004

Software development is a dynamic process and is characterized by change. Software projects often begin with unclear, ambiguous, and incomplete requirements which give rise to intrinsic volatility. Constant change in requirements is one of the main causes of software defects and a major issue faced by the software industry. This paper describes the findings of our research-based study that investigates the impact of both the pre-release and post-release requirements changes on overall defects by defining measures, collecting data against those measures and analyzing the collected data through statistical techniques. Our findings, based on industry data from 4 software projects consisting of 30 releases, all in e-commerce domain, indicate that there is a significant relationship between pre/post release change requests initiated by the client and software defects. In addition, our data analysis indicates that changes in the design of the system at the later stages of software development i.e., during coding, testing and after release have a significant impact on the high severity defects that affect the major functionality of the system. Also, we found that insufficient time spent on the design phase and inadequate communication with the client could be some of the causes of requirements changes and consequently software defects.
Pattern hybridization
Authors: Janaki Ram D. , Jithendra Kumar Reddy P. , Rajasree M. S.
Published: July 2004

Class or object interactions form the basis of object-oriented design. However, design pattern interaction can be viewed as a higher level of abstraction for system design. The typical interactions among the patterns are a pattern uses another pattern to solve one of its sub problem, and a pattern combines with another pattern for completeness. This paper proposes a mechanism called pattern hybridization for breeding new patterns from the pattern interactions which solve more specialized problems than the original patterns do. Rules for generating hybrid patterns are also mentioned in the paper. This paper also views design pattern interactions for system design.
Computer science education in business schools
Authors: Chand Donald R.
Published: July 2004

In 1969, the Business School of Georgia State University (GSU) initiated a new program of study leading to the degree Master of Business Information Systems (MBIS). The program has gone through a series of refinements in order to better fulfill its primary objective of developing business systems designers and information analysts who would be responsible for designing, implementing and evaluating computer based information systems in organizations. The lack of a model that may be used for constructing a suitable curriculum led the author to the development of a goal oriented approach for designing curricula. It provides a systematic way of designing a curriculum for an evolving multidimensional field like computer science. This paper describes the factors that led to the development of this approach and its practical advantages.
Iterations on an instructional method for utilizing the computer in the classroom
Authors: Miller James E.
Published: July 2004

The recent advent of reasonably priced semiportable and portable computer systems has opened up a fascinating array of opportunities for bringing the computer into the classroom. This article reports on two approaches that have been used with considerable success at the University of West Florida in the Introduction to Data Processing course. These two approaches are considered to be iterations on the instructional methods reported by Richard Cheng in the February 76 Joint Bulletin of SIGCUE and SIGCSE, where he presented the use of an on-line large screen display system.
The computer science minor, a description and a proposal
Authors: Linder William H.
Published: July 2004

Along with undergraduate and graduate degree programs in computer science, the Department of Mathematics and Computer Science at the University of South Carolina (USC) offers a computer science minor. The recommended computer science minor at USC consists of the first four courses of the undergraduate computer science degree program. A survey of the graduates of 1977 from the College of Science and Mathematics at USC shows that there was a surprisingly low number of students completing the computer science minor. Several reasons are given for this, and a proposal is presented for modifications in the computer science minor.The Computer Science Minor at USC
COMPI
Authors: Pangratz Heinrich
Published: July 2004

A computer model for illustrating basic computer functions is presented. The model offers 16 instructions including a subroutine jump, indirect addressing, and 64 words of memory. Instruction and data entry is simplified by mnemonics and the use of a dedicated keyboard. Arrangement and lettering of the keys make the model self-explanatory without additional operating instructions. Contents of registers and memory are displayed on a screen. Programs may be executed in a "slow"-mode, where data transfers are illustrated by moving the information on the screen from one location to another. For the student the model combines hands-on experience on a computer console with the illustrative power of a film.
Another experiment with teaching of programming languages
Authors: Mavaddat Farhad
Published: July 2004

The key issue in successful teaching is that of keeping the interest of students alive. In a first course on computer programming, this can be achieved by presenting interesting problems of reasonable complexity early in the course. This is often a difficult task, as most of the common programming languages used for instruction are intangible and therefore cumbersome to master before any serious programming may start.Here a simple and tangible programmable machine is introduced. It is shown that important programming concepts can be defined and exercised in terms of possible operations on this machine. It is also shown that a seemingly difficult problem can be solved by novice programmers within the first few sessions of an introductory course.
Experiences with a continuing education seminar
Authors: Leigh William E.
Published: July 2004

An ongoing, evening seminar concerning the selection and use of computers in small business is described. The factors affecting the attendee response to each of the five offerings and the course format as currently evolved are discussed.Under the titles of "Small Business Computers: Potentials and Pitfalls" and "Computers for Small Business: What, why, and How?", this short seminar has attracted over 80 participants. The objective of the seminar is to help a small business person decide if a computer is a feasible solution to his problem, and, if so, how to go about using the computer. The course emphasizes the failures as well as the successes that can be anticipated in trying to install a computer in a small business. Case studies and "war stories" have been found to be some of its best received features.All offerings of the seminar have been publicized primarily through the enclosure of a leaflet in the monthly mailing of the local chamber of commerce organizations (Cincinnati, Ohio, and Northern Kentucky). Under the heading of "Who Should Attend", the leaflet states:This seminar will be of interest to small business owners and operators concerned with computer acquisition and use. Others with interest but no job related need in the field are also encouraged to participate.
Jackson techniques for elementary data processing
Authors: Molluzzo John C.
Published: July 2004

Although useful in solving elementary data processing problems, the program design techniques of M. A. Jackson are virtually unknown in elementary courses. The basic principles of Jackson's techniques are introduced and used to solve two common elementary data processing problems.
Personal computers in the undergraduate curriculum
Authors: Kelsh James P. , Hansen John C.
Published: July 2004

The authors will show how off-the-shelf personal computers can be used in a variety of ways and at a number of levels to enrich the study of computers at small colleges. It is not our intent to suggest that personal computers replace larger mainframes in computer science courses. Rather, we intend to show how these computers can be used to give small colleges the ability to teach meaningful courses in subjects which until recently could be taught only at universities fortunate enough to possess large computer laboratories and their own hardware experts.
Practical computer logic classes for computer science students
Authors: Coey W. A. , Fay D. Q. M.
Published: July 2004

Undergraduate students in our Computer Science Honours degree course are introduced to logic analysers and other test equipment in a series of hardware experiments taken during their third year. This paper describes our approach and details of three of these experiments which use logic analysers.
An office automation course
Authors: Juell Paul L.
Published: July 2004

At the University of Wyoming a course was developed on office automation. This course attempts to expose the student to a number of the software tools being used in the "automated office". The exposure is both in the lecture format and by having the students use the software tools available at this installation.There are three parts to the course.The first part discussed text editors. The editors used are the UCSD text editor, and the CYBER's text editor, XEDIT.The second part discussed text processors. The text processors used are TEXTJAB, and RNF, both of which are available on our CYBER computers.The last part discussed other topics of interest including: utility programs, electronic mail, data base management systems and some of the effects of technology on office operations.The use of the computer as an information processing tool was emphasized by its use all phases of the class. For example, all materials that would normally be distributed in handouts were placed on-line on the computer and the students had to obtain copies of the material from the machine.
Articulation
Authors: Gorsline G. W.
Published: July 2004

Arguments are presented supporting a freshman-level course to assist students entering a post-secondary computer science program to acquire the very basic fundamentals of the subject that may not have been available to them during their secondary school experience. We believe that most colleges, universities, and community colleges have increased the rigor of their versions of the Curriculum 78 course CS 1 to the extent that prerequisite knowledge and skills would be very helpful to a large number of students. While it is suggested that these fundamentals can best be learned in a pre-college setting, for those students lacking such a background (currently the vast majority), it is argued that an articulation course must be available. It is strongly suggested that an excellent prescription for the necessary course materials is given in the ACM ES
3
report by Rogers and Austing (7). It must be noted that many colleges currently offer and require an equivalent course or courses.
A practical training in software engineering methodology
Authors: Wu B. F.
Published: July 2004

This paper reports the application of large-scale software engineering methodology to small software projects. These projects were part of the curriculum of the recently launched Motorola Entry Level Training Program For Software Engineers, for college graduates. The results indicated that large scale software engineering methodology can be applied successfully to small projects. In addition, our results support most of Barry Boehm's findings in a similar study. The "deadline effect," as observed by Boehm holds especially true in our software projects and can be used to help manage software development.Contrary to Boehm's results, however, we found that programming including debugging is the dominant activity in small software product development. Possible reasons are given to explain this difference.
An outline of a capacity planning course
Authors: Conner William M.
Published: July 2004

An outline of a capacity planning course is presented which SIGCSE members may find useful for designing an entire performance evaluation course or a component of an operating systems or modeling course. Topics referenced in the outline include: workload characterization and forecasting, performance prediction, tuning, measurement monitors, and commercially available tools.
Structured design methodology for a course on computer science in engineering
Authors: Medsker Larry R.
Published: July 2004

The design of a course in computer science for engineers is being guided by techniques of instructional technology that facilitate the development of an efficient and effective course. An overview of the methodology and its application to this particular course are described.
A "realistic" approach for educating systems programmers
Authors: Spence J. Wayne , Guynes Steve
Published: July 2004

Educating systems programmers to handle real world problems can be very difficult. Each step in the translation process from perception to production has the potential of inducing errors into the production system as a result of the complexity and abstractness of the "real world" system. The task involves developing a system of personnel, procedures, equipment, and computer programs which together emulate the "real world" system.
The impact of fourth generation programming languages
Authors: Tharp Alan L.
Published: July 2004

Fourth generation programming languages are affecting the way in which software is developed. This paper describes what they are and their impact on industry, computer science education and the demand for programmers. The focus of the paper is on whether and/or where fourth generation programming languages should be included in a computer science curriculum.
Training the trainers
Authors: Kushner Jeffrey
Published: July 2004

High quality education involves a lot of time and effort on the part of all involved in the process of facilitating learning. If the time and effort can be invested, there will be a good return realized. Unfortunately, this luxury is not always available. The ultimate problem is that the one who loses out most is the one seeking new knowledge.This article presents the perceptions of difference in course development and, more importantly, preparation of the one who will deliver the information sought by the learners: the instructor.
A problem of integration
Authors: Lyster Norman C.
Published: July 2004

Many programming courses tend to be taught in isolation. Isolation from real world applications and isolation internally from their parts. COBOL, as a significant business oriented language that is extensively utilized, lends itself to integration as easily as any language and more easily than most. This integration is important as COBOL is extensively utilized in a variety of business applications. Still, COBOL frequently suffers from being taught isolated segment by isolated segment. It is also frequently taught in isolation from its world of applications. This paper will suggest some techniques for overcoming this tendency toward disjointed segmentation in an introductory COBOL class.
A method for introducing schemas
Authors: Mugridge Warwick B. , Hosking John G.
Published: July 2004

A simple file schema system is described which is useful for introducing undergraduate students to the concepts and uses of database schemas. Practical exercises using the system provide valuable reinforcement to the formal lessons.
A survey of CIS graduates from the University of Florida, College of Engineering
Authors: Brownsmith Joseph D.
Published: July 2004

This paper presents the results of a survey of recent graduates of the University of Florida, College of Engineering who majored in Computer and Information Sciences. The survey requested employment information, e.g. Company, job title, job activities (type of activity, percent of time spent on activity). The survey also asked for feedback on the relevance of the curriculum to their present employment.The results indicate that 95% are presently employed in a computer related field, and that 67% employed by computer vendors or engineering/technology companies. also, 38% have the word "engineer" in their job title. 86% engage in programming and spend an average of 44% of their time on it.This survey was conducted as part of an ABET accreditation.
The role of a comparative programming languages course in the computer science curriculum
Authors: Pagan Frank G.
Published: July 2004

It is proposed that the programming languages aspect of the undergraduate curriculum for computer science be designed around a course in Comparative Programming Languages. The advantages and implications of such a scheme are outlined.
A student-use
Authors: Germano Frank , Higgenbotham Stephen
Published: July 2004

The use of Data Base Management Systems as a teaching tool in Data Management classes is described. Several alternate student-use DBMS are evaluated including GPLAN, IDBS, WAND, and DL/S. DL/S, developed at Temple University, is a limited subset of IMS designed for classroom use. However, the limitations do not prevent the student from learning how to interface with a DBMS during the implementation of a course project. An overview of the DL/S data definition language (DDL) and data manipulation language (DML) is presented along with a discussion of its implementation and associated limitations.
A data base course for business students
Authors: Stern Myles
Published: July 2004

In order to outline what business students need to know about data base management (DBM), this paper first identifies the four most pertinent DBM concepts: (1) characteristics and benefits of DBM, (2) design of data base schemas, (3) set-theoretic queries, and (4) the transition to DBM. Next, the paper discusses four secondary concepts and the reasons for not stressing them. Finally, the need for further co-ordination between DBM instructors and faculty members in the functional areas of business administration is described.
Using captioned slides to teach computer operations
Authors: Murray Bob , Policano Tom , Sweeney John
Published: July 2004

A demonstration of a typical media package designed to faciliate group instruction in computer operations will be presented. The package consists of slides, captions stored on a filmstrip, and an illustrated workbook. Detailed sequential procedures can be shown to the students through a slide presentation thus saving expensive computer time. The media packages can also be used by individual students who wish to review the laboratory exercises. Each slide presentation closely follows the steps of a sequential laboratory procedure. This new captioning system allows verbal explanations and cueing techniques such as circles and arrows used to enhance the meaning of the visuals. The workbook is closely correlated with the slide presentation and is illustrated with prints of selected slides. This system allows revision of captions, workbook, or slides without revision of the entire instruction unit.
Low-cost, adaptable tool integration policies for integrated environments
Authors: Garlan David , Ilias Ehsan
Published: July 2004

An important requirement for successful integrated programming environments is support for implicit tool invocation; rather than force a user to explicitly invoke each tool, mechanisms in the environment can take responsibility for guaranteeing that the right tools are invoked at the right times. However, these mechanisms typically intertwine policies of when and how the tools are invoked, with what the tools do when they are invoked. Consequently, adapting the environment to achieve different tool interactions is often difficult without modifying the code that implements the environment or the tools. In this paper we describe a simple, low-cost mechanism that solves this problem. Specifically, we show how tool integration based on selective broadcast can be adapted to allow dynamically configurable policies of tool interaction. We describe an implementation of these mechanisms, and show how it supports multiple levels of users.
Managing software processes in the environment MELMAC
Authors: Gruhn Volker
Published: July 2004

In this paper we introduce an approach to software process modeling and execution based on the distinction between an application level (oriented towards a comprehensive representation of software process models) and an intermediate level representation of software process models (oriented towards uniform and executable description of software process models). The application level representation of software models identifies various entities of software process models. For describing different entities of software process models different views are used. The entities specified within all the views are uniformly represented on the intermediate level by FUNSOFT nets. FUNSOFT nets are high-level Petri nets which are adapted to the requirements of software process management. A mechanism for coping with software process model modifications raised in software process execution is introduced. This mechanism is based on modification points. Moreover, we discuss the architecture of the environment MELMAC which supports software process modeling as well as software process execution.
Taurine increases glucose sensitivity of UCP2-overexpressing β-cells by ameliorating mitochondrial metabolism
Authors: Han Jin , Bae Jae Hoon , Kim So-Yeon , Lee Hyun-Young , Jang Byeong-Churl , Lee In-Kyu , Cho Chi-Heum , Lim Jeong-Geun , Suh Seong-Il , Kwon Taeg-Kyu , Park Jong-Wook , Ryu Shin Young , Ho Won-Kyung , Earm Yung-E , Song Dae-Kyu
Published: July 2004

A low-taurine diet during fetal or early postnatal life causes abnormal pancreatic β-cell development. Tissue and plasma taurine concentrations can also be low in diabetic patients. We examined the effect of taurine on impaired glucose responses in diabetic rat β-cells adenovirally overexpressing uncoupling protein (UCP)2, which is upregulated in obesity-related type 2 diabetes. We found that taurine pretreatment restored the ATP-to-ADP (ATP/ADP) ratio and glucose-stimulated insulin secretion in UCP2-infected islets. ATP-sensitive K+ channel sensitivity to dihydroxyacetone, another insulin secretagogue, was similar in both UCP2-infected and control β-cells. In freshly isolated mitochondria from UCP2-overexpressing insulin-secreting (INS)-1 β-cells, methyl pyruvate-mediated mitochondrial Ca2+ increase was significantly ameliorated by taurine. A mitochondrial Ca2+ uniporter blocker, ruthenium red, inhibited the action of taurine. This study suggests that taurine enhances the glucose sensitivity of UCP2-overexpressing β-cells, probably by increasing mitochondrial Ca2+ influx through the Ca2+ uniporter, thereby enhancing mitochondrial metabolic function and increasing the ATP/ADP ratio.
Gonadotropin-releasing hormone and TGF-β activate MAP kinase and differentially regulate fibronectin expression in endometrial epithelial and stromal cells
Authors: Luo Xiaoping , Ding Li , Chegini Nasser
Published: July 2004

Gonadotropin-releasing hormone analog (GnRHa) is used for medical management of endometriosis and premature luteinizing hormone surge during controlled ovarian stimulation. Human endometrium expresses GnRH receptors, and GnRHa alters the expression of transforming growth factor-β (TGF-β) and receptors in endometrial cells. Because the diverse biological actions of GnRHa and TGF-β are mediated in part through the MAPK pathway, we determined whether utilization of MAPK/ERK and transcriptional activation of immediate early genes c- fos and c- jun result in differential regulation of fibronectin, known as key regulator of embryo implantation and endometriosis progression. Using endometrial stromal cells (ESC) and the endometrial epithelial cell line HES, we demonstrated that GnRHa and TGF-β, in a dose-, time-, and cell-dependent manner, increased the level of phosphorylated ERK1/2 (pERK1/2). GnRH antagonist Antide also increased pERK1/2 induction in ESC and HES, whereas pretreatment reduced GnRHa-induced pERK2 in ESC but not in HES. Cotreatments with GnRHa plus TGF-β1 did not have an additive or an inhibitory effect on pERK1/2 induction compared with GnRHa or TGF-β1 action alone. TGF-β1 and GnRHa increased ERK1/2 nuclear accumulation and inversely regulated the expression of c- fos and c- jun and that of fibronectin in a cell-specific manner. Pretreatment with U-0126, a MEK1/2 inhibitor, blocked basal, as well as GnRHa- and TGF-β1-induced pERK1/2; however, it differentially affected c- fos, c- jun, and fibronectin expression. In conclusion, the results indicate that GnRHa and TGF-β signaling through MAPK/ERK results in differential regulation of fibronectin expression in endometrial cells, a molecular mechanism where short- and long-term GnRHa therapy and locally expressed TGF-β could influence embryo implantation and endometriosis implants, respectively.
Dopamine recruits D1Areceptors to Na-K-ATPase-rich caveolar plasma membranes in rat renal proximal tubules
Authors: Trivedi Meghna , Narkar Vihang A. , Hussain Tahir , Lokhandwala Mustafa F.
Published: July 2004

Activation of dopamine D1Areceptors in renal proximal tubules causes inhibition of sodium transporters (Na-K-ATPase and Na/H exchanger), leading to a decrease in sodium reabsorption. In addition to being localized on the plasma membrane, D1Areceptors are mainly present in intracellular compartments under basal conditions. We observed, using [3H]SCH-23390 binding and immunoblotting, that dopamine recruits D1Areceptors to the plasma membrane in rat renal proximal tubules. Furthermore, radioligand binding and/or immunoblotting experiments using pharmacological modulators showed that dopamine-induced D1Areceptor recruitment requires activation of cell surface D1-like receptors, activation of adenylyl cyclase, and intact endocytic vesicles with internal acidic pH. A key finding of this study was that these recruited D1Areceptors were functional because they potentiated dopamine-induced [35S]GTPγS binding, cAMP accumulation, and Na-K-ATPase inhibition. Interestingly, dopamine increased immunoreactivity of D1Areceptors specifically in caveolin-rich plasma membranes isolated by a sucrose density gradient. In support of this observation, coimmunoprecipitation studies showed that D1Areceptors interacted with caveolin-2 in an agonist-dependent fashion. The caveolin-rich plasma membranes had a high content of the α1-subunit of Na-K-ATPase, which is a downstream target of D1Areceptor signaling in proximal tubules. These results show that dopamine, via the D1-like receptor-adenylyl cyclase pathway, recruits D1Areceptors to the plasma membrane. These newly recruited receptors couple to G proteins, increase cAMP, and participate in dopamine-mediated inhibition of Na-K-ATPase in proximal tubules. Moreover, dopamine-induced recruitment of D1Areceptors to the caveolin-rich plasma membranes brings them in close proximity to targets such as Na-K-ATPase in proximal tubules of Sprague-Dawley rats.
Effect of thiazide on renal gene expression of apical calcium channels and calbindins
Authors: Lee Chien-Te , Shang Shuhua , Lai Li-Wen , Yong Kim-Chong , Lien Yeong-Hau H.
Published: July 2004

Thiazide diuretics are specific inhibitors of the Na-Cl cotransporter in the distal convoluted tubule (DCT). In addition to producing diuresis and natriuresis, they have a hypocalciuric effect. Recently, two apical calcium channels have been identified, transient receptor potential vanilloid 5 (TRPV5) and TRPV6; both are expressed in the DCT. We studied the effects of thiazides on mouse renal calcium handling and renal gene expression of TRPV5 and TRPV6, as well as calbindin-D28kand calbindin-D9k, both of which are calcium transport facilitators located in the DCT. Upregulation of renal TRPV5 was found 4 h after intraperitoneal injection of chlorothiazide (CTZ) at both 25 and 50 mg/kg, but not at 100 mg/kg. Chronic treatment with CTZ at 25 mg/kg twice daily for 3 days, with or without salt supplementation of 0.8% NaCl and 0.1% KCl in the drinking water, caused hypocalciuria, but the gene expression patterns were different. Without salt supplementation, mice developed volume contraction and there were no changes in gene expression. When volume contraction was prevented by salt supplementation, there was a significant increase in gene expression of TRPV5, calbindin-D28k, and calbindin-D9k. Salt supplementation alone also induced significant upregulation of TRPV5, TRPV6, and both calbindins. The upregulation of TRPV5 by CTZ and salt supplementation and salt alone was further confirmed with immunofluorescent staining studies. Our studies suggest that thiazides induce hypocalciuria through different mechanisms depending on volume status. With volume contraction, increased calcium reabsorption in the proximal tubule plays the major role. Without volume contraction, hypocalciuria is probably achieved through increased calcium reabsorption in the DCT by the activation of a transcellular calcium transport system and upregulation of apical calcium channel TRPV5, calbindin-D28k, and calbindin-D9k.
Vascular Actions of Calcitonin Gene-Related Peptide and Adrenomedullin
Authors: Brain Susan D. , Grant Andrew D.
Published: July 2004

This review summarizes the receptor-mediated vascular activities of calcitonin gene-related peptide (CGRP) and the structurally related peptide adrenomedullin (AM). CGRP is a 37-amino acid neuropeptide, primarily released from sensory nerves, whilst AM is produced by stimulated vascular cells, and amylin is secreted from the pancreas. They share vasodilator activity, albeit to varying extents depending on species and tissue. In particular, CGRP has potent activity in the cerebral circulation, which is possibly relevant to the pathology of migraine, whilst vascular sources of AM contribute to dysfunction in cardiovascular disease. Both peptides exhibit potent activity in microvascular beds. All three peptides can act on a family of CGRP receptors that consist of calcitonin receptor-like receptor (CL) linked to one of three receptor activity-modifying proteins (RAMPs) that are essential for functional activity. The association of CL with RAMP1 produces a CGRP receptor, with RAMP2 an AM receptor and with RAMP3 a CGRP/AM receptor. Evidence for the selective activity of the first nonpeptide CGRP antagonist BIBN4096BS for the CGRP receptor is presented. The cardiovascular activity of these peptides in a range of species and in human clinical conditions is detailed, and potential therapeutic applications based on use of antagonists and gene targeting of agonists are discussed.
Bone Density and Insertion Torque as Predictors of Anterior Cruciateligament Graft Fixation Strength
Authors: Järvinen Teppo L. N. , Nurmi Janne T. , Sievänen Harri
Published: July 2004

Background

Bone mineral density and interference screw insertion torque are thought to be useful predictors of anterior cruciate ligament graft fixation strength.

Hypothesis

Bone mineral density and insertion torque are reliable predictors of anterior cruciate ligament graft fixation strength.

Study Design

Randomized experimental study.

Methods

The volumetric bone mineral density, maximum insertion torque, and initial fixation strength (determined both as cyclic-loading-induced displacement and yield load) were recorded on 21 pairs of anterior cruciate ligament reconstructions. To assess the accuracy of bone mineral density and insertion torque in predicting the fixation strength, half of the specimens were first used to determine the regression equations between the variables, and then the data from the remaining specimens were used to validate the prediction equations.

Results

Despite the relatively high group correlations, the ability of bone mineral density and insertion torque to predict the strength of graft fixation was poor. Errors ranging from –150% to 92%, –22% to 50%, –56% to 121%, and –23% to 50% were observed when bone mineral density and insertion torque were used to predict individual cyclic-loading-induced displacement and yield load, respectively.

Conclusions

Neither bone mineral density nor insertion torque provides a sufficiently accurate prediction of the fixation strength of an individual soft tissue anterior cruciate ligament graft.

Clinical Relevance

Bone mineral density and insertion torque cannot be used to estimate the strength of interference screw fixation in anterior cruciate ligament reconstruction.
The Effect of a Proprioceptive Balance Board Training Program for the Prevention of Ankle Sprains
Authors: Verhagen Evert , van der Beek Allard , Twisk Jos , Bouter Lex , Bahr Roald , van Mechelen Willem
Published: July 2004

Background

Ankle sprains are the most common injuries in a variety of sports.

Hypothesis

A proprioceptive balance board program is effective for prevention of ankle sprains in volleyball players.

Study Design

Prospective controlled study.

Methods

There were 116 male and female volleyball teams followed prospectively during the 2001-2002 season. Teams were randomized by 4 geographical regions to an intervention group (66 teams, 641 players) and control group (50 teams, 486 players). Intervention teams followed a prescribed balance board training program; control teams followed their normal training routine. The coaches recorded exposure on a weekly basis for each player. Injuries were registered by the players within 1 week after onset.

Results

Significantly fewer ankle sprains in the intervention group were found compared to the control group (risk difference = 0.4/1000 playing hours; 95% confidence interval, 0.1-0.7). A significant reduction in ankle sprain risk was found only for players with a history of ankle sprains. The incidence of overuse knee injuries for players with history of knee injury was increased in the intervention group. History of knee injury may be a contraindication for proprioceptive balance board training.

Conclusions

Use of proprioceptive balance board program is effective for prevention of ankle sprain recurrences.
A Prospective Video-Based Analysis of Injury Situations in Elite Male Football
Authors: Arnason Arni , Tenga Albin , Engebretsen Lars , Bahr Roald
Published: July 2004

Background

The mechanisms for football injuries are largely unknown.

Aim

To describe the characteristics of injury situations in elite male football using a video-based method called football incident analysis.

Study Design

Prospective cohort study.

Methods

During the 1999 season, videotapes from 52 matches in the Icelandic elite football league were reviewed. Incidents (N = 95) were recorded when the match was interrupted by the referee because of a suspected injury. Team physical therapists recorded injuries prospectively (N = 28 time-loss injuries).

Results

Duels caused 84 of the incidents, mostly tackling duels (n = 54). The exposed player's attention appeared to be focused away from the opponent in 93% of the cases. The 3 main mechanisms observed were (1) breakdown attacks, tackling from the side or the front, attention focused on the ball (24%); (2) defensive tackling duels, attention focused on the ball or low ball control (20%); and (3) heading duels, attention focused on the ball in the air (13%).

Conclusion

Most incidents and injuries occurred during breakdown attacks and when a player was involved in tackling duels. Player attention appeared to be focused mainly on the ball, not on the opponent challenging him to gain ball possession.
Interspecies Variation in the Fibroblast Distribution of the Anterior Cruciate Ligament
Authors: Murray Martha Meaney , Weiler Andreas , Spindler Kurt P.
Published: July 2004

Background

The future of the treatment of a ruptured anterior cruciate ligament is likely to involve cell-based therapies. These therapies are intrinsically dependent on the cellular distributions in the ligament. Thus, when selecting an animal model for testing of these new treatment methods, it is important to select a model that has similar cellular distributions to that of the normal human anterior cruciate ligament.

Hypothesis

There are interspecies differences in the histology of the anterior cruciate ligament.

Study Design

A descriptive histological study comparing the cell and vessel distribution of normal human anterior cruciate ligaments with that of 3 animal models and anterior cruciate ligaments from osteoarthritic human knees.

Methods

The histology of each of the anterior cruciate ligament sources was quantified in terms of cell number density, expression of α-smooth muscle actin, blood vessel density, and cell nuclear morphology using standardized histomorphometric techniques.

Results

The normal human anterior cruciate ligament was similar to the canine anterior cruciate ligament and the anterior cruciate ligament from patients with osteoarthritis with respect to cell density, blood vessel density, and cell nuclear shape. The normal anterior cruciate ligament had significantly fewer vessels than the bovine anterior cruciate ligament and rounder cells than the bovine and ovine anterior cruciate ligaments.

Conclusions

There is significant interspecies variation in the histology of the anterior cruciate ligament, with the canine anterior cruciate ligament most similar to the human anterior cruciate ligament.

Clinical Relevance

This finding may have an effect on the accuracy of testing of new, cell-based treatments for the ruptured anterior cruciate ligament, such as guided tissue regeneration.
Follow-Up of Osteochondral Plug Transfers in a Goat Model
Authors: Lane John G. , Massie Jennifer B. , Ball Scott T. , Amiel Michael E. , Chen Albert C. , Bae Won C. , Sah Robert L. , Amiel David
Published: July 2004

Background

Osteochondral transfer procedures are increasingly used to resurface full-thickness articular cartilage defects. There has not been long-term assessment/description of autogenous donor and recipient sites.

Hypothesis

The healing process occurs at the donor/host cartilage and bone interfaces.

Study Design

Histologic, biochemical, and biomechanical changes were assessed 6 months after an osteochondral transfer in a goat model.

Methods

Eight adult goats were studied. In the 6 osteochondral transfer goats, 2 autogenous plugs were transferred from the femoral trochlea to defects in the weightbearing portion of the medial femoral condyle. The goats were allowed free range for 6 months. Randomly assigned plugs were assessed.

Results

Knees of the sacrificed animals had preservation of the joint space with mild chondromalacic changes in both transfer and contralateral control groups. Histologically, no evidence of cartilage (host/donor) healing was seen. Subchondral bone of the plug was contiguous with the surrounding recipient bone. Cellular viability in the autogenous osteochondral plug was seen, and 35SO4 uptake of the articular cartilage was not statistically different from the contralateral control condyle. The indentation stiffness of the transfer plug (mosaicplasty) and the contralateral donor site were similar—much stiffer than normal cartilage including surrounding condylar cartilage. Large structural stiffness of transferred cores and donor sites appeared to be related to their thinner cartilage layer.

Conclusions

At 6-month follow-up, a cleft between host and transferred articular regions remained, with no integration between the two.

Clinical Relevance

Autogenous transplantation of osteochondral plugs is possible with integration of subchondral bone and preservation of chondral viability.
Adult Burkitt leukemia and lymphoma
Authors: Blum Kristie A. , Lozanski Gerard , Byrd John C.
Published: July 2004

The World Health Organization Classification of Lymphoid Neoplasms identifies Burkitt lymphoma/leukemia as a highly aggressive mature B-cell neoplasm consisting of endemic, sporadic, and immunodeficiency-associated variants. These subtypes share many morphologic and immunophenotypic features, but differences exist in their clinical and geographic presentations. All of these subtypes possess chromosomal rearrangements of the c-myc oncogene, the genetic hallmark of Burkitt lymphoma that contributes to lymphomagenesis through alterations in cell cycle regulation, cellular differentiation, apoptosis, cellular adhesion, and metabolism. Brief-duration, high-intensity chemotherapy regimens containing aggressive central nervous system prophylaxis have had remarkable success in the treatment of this disease, with complete remission rates of 75% to 90% and overall survivals reaching 50% to 70% in adults. Although Burkitt lymphoma cells are extremely chemosensitive, biologically targeted therapies should be developed because current treatment options are suboptimal for patients with poor prognostic features or in the setting of relapsed disease.
Conserved CTL epitopes on the adenovirus hexon protein expand subgroup cross-reactive and subgroup-specific CD8+ T cells
Authors: Leen Ann M. , Sili Uluhan , Vanin Elio F. , Jewell Alan M. , Xie Weidong , Vignali Dario , Piedra Pedro A. , Brenner Malcolm K. , Rooney Cliona M.
Published: July 2004

Adenoviruses often cause lethal infections in immunocompromised individuals. Adoptive transfer of immune T cells offers a therapeutic option, but this strategy has been hindered by the paucity of information on molecular targets of cellular immunity and by the immunologic heterogeneity of the 51 human adenoviruses, which are grouped from A to F on the basis of genome size, composition, homology, and organization. Clonal analysis of the adenovirus-specific cytotoxic T lymphocyte (CTL) responses of seropositive individuals identified 5 novel CD8+ T-cell epitopes, all located in conserved regions of the capsid protein hexon. Reactive T cells were cross-reactive between 2 to 4 groups, while no T cells specific for a single subgroup were detected. Thus, by exploiting these peptide targets, it is possible to prepare a T-cell population capable of reacting with most adenoviruses that cause disease in immunocompromised patients.