bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the abundance and subunit composition of GABAA receptor subtypes in the cerebellum of α1‐subunit‐deficient mice
Authors: Ogris Waltraud , Lehner Reinhard , Fuchs Karoline , Furtmüller Birgit , Höger Harald , Homanics Gregg E. , Sieghart Werner 
Published: November 2005

AbstractIn cerebellum, 75% of all GABAA receptors contain α1 subunits. Here, we investigated compensatory changes in GABAA receptor subunit expression and composition in α1 subunit‐knockout mice. In these mice the total number of cerebellar GABAA receptors was reduced by 46%. Whereas the number of receptors containing α6 subunits was unchanged, the total amount of α6 subunits was significantly elevated. RT‐PCR showed no increase of α6 mRNA levels, arguing against increased biosynthesis of these subunits. Elevated levels of α6 subunits in α1 ‐/‐ mice might thus have been caused by an increased incorporation of unassembled α6 subunits, replacing α1 subunits in α1α6βγ2 or α1α6βδ receptors, thus rescuing α6 subunits from degradation. Elevated levels of α3 and α4 subunits in the cerebellum of α1 ‐/‐ mice possibly can be explained similarly. Finally, a small amount of receptors containing no γ or δ subunits was identified in these mice. Results suggest a total loss of GABAA receptors in cell types where α1 was the only α subunit expressed and a partial compensation for receptor loss in cell types containing other α subunits. Our results do not support a significant compensatory synthesis of other GABAA receptor subunits in the cerebellum of α1 ‐/‐ mice.
Altered glycosylation of acetylcholinesterase in Creutzfeldt–Jakob disease
Authors: Silveyra María‐Ximena , Cuadrado‐Corrales Natividad , Marcos Alberto , Barquero María‐Sagrario , Rábano Alberto , Calero Miguel , Sáez‐Valero Javier 
Published: November 2005

AbstractChanges in the glycosylation pattern of brain proteins have been associated with Creutzfeldt–Jakob disease (CJD). We have investigated the glycosylation status of acetylcholinesterase (AChE) by lectin binding assay. Our data show that in lumbar CSF from definite and probable sporadic CJD cases AChE activity is lower compared with that in age‐matched controls. We also show, for the first time, that AChE glycosylation is altered in CJD CSF and brain. Unlike Alzheimer's disease, in which an alteration in both the glycosylation and levels of AChE molecular forms is observed, the abnormal glycosylation of AChE in CJD appears to be unrelated to changes in molecular forms of this enzyme. These findings suggest that altered AChE glycosylation in CJD may be a consequence of the general perturbation of the glycosylation machinery that affects prion protein, as well as other proteins. The diagnostic potential of these changes remains to be explored.
Cocaine‐induced alterations in nucleus accumbens ionotropic glutamate receptor subunits in human and non‐human primates
Authors: Hemby Scott E. , Tang Wenxue , Muly Emil C. , Kuhar Michael J. , Howell Leonard , Mash Deborah C. 
Published: November 2005

AbstractChronic cocaine and withdrawal induce significant alterations in nucleus accumbens (NAc) glutamatergic function in humans and rodent models of cocaine addiction. Dysregulation of glutamatergic function of the prefrontal cortical–NAc pathway has been proposed as a critical substrate for unmanageable drug seeking. Previously, we demonstrated significant up‐regulation of NMDA, (±)‐α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid (AMPA) and kainate receptor subunit mRNAs and protein levels in the ventral tegmental area (VTA), but not the substantia nigra, of cocaine overdose victims (COD). The present study was undertaken to examine the extent of altered ionotropic glutamate receptor (iGluR) subunit expression in the NAc and the putamen in cocaine overdose victims. Results revealed statistically significant increases in the NAc, but not in the putamen, of NMDA receptor subunit (NR)1 and glutamate receptor subunit (GluR)2/3 wit trends in GluR1 and GluR5 in COD. These results extend our previous finding and indicate pathway‐specific alterations in iGluRs in COD. In order to determine that changes were related to cocaine intake and not to other factors in the COD victims, we examined the effects of cocaine intravenous self‐administration in rhesus monkeys for 18 months (unit dose of 0.1 mg/kg/injection and daily drug intake of 0.5 mg/kg/session). Total drug intake for the group of four monkeys was 37.9 ± 4.6 mg/kg. Statistically significant elevations were observed for NR1, GluR1, GluR2/3 and GluR5 (p < 0.05) and a trend towards increased NR1 phosphorylated at serine 896 (p = 0.07) in the NAc but not putamen of monkeys self‐administering cocaine compared with controls. These results extend previous results by demonstrating an up‐regulation of NR1, GluR2/3 and GluR5 in the NAc and suggest these alterations are pathway specific. Furthermore, these changes may mediate persistent drug intake and craving in the human cocaine abuser.
Cloning of ad‐serine‐regulated transcriptdsr‐2from rat cerebral neocortex
Authors: Taniguchi Go , Yamamoto Naoki , Tsuchida Hideto , Umino Asami , Shimazu Dai , Sakurai Shin‐ichiro , Takebayashi Hironao , Nishikawa Toru 
Published: November 2005

Abstractd‐Serine is now considered to be an endogenous co‐agonist of the NMDA receptor in mammalian brain. To obtain insight into the molecular mechanisms underlyingd‐serine metabolism and function, we explored transcripts that are responsive tod‐serine in the neocortex of the 8‐day‐old infant rat by a differential cloning technique, RNA arbitrarily primed PCR. We isolated a noveld‐serine inducible transcript,d‐serine‐responsive transcript‐2 (dsr‐2), that was exclusively expressed in the brain. Sequence analysis of the corresponding cDNAs to the transcript revealed that thedsr‐2mRNA consists of 7199 nucleotides with an open reading frame encoding 111 amino acids. Thedsr‐2gene was located on the reverse strand within an intron of the neurexin‐3α gene, mapped to rat chromosome 6q24‐31. The regional distribution of the basal expression ofdsr‐2and its ontogenic changes in the brain closely correlated with those of freed‐serine and of NMDA receptor R2B subunit mRNA, but were somewhat different from those of the neurexin‐3α transcript. These findings suggest thatdsr‐2may be involved ind‐serine metabolism and/or function, and in the interactions betweend‐serine, NMDA receptor and neurexin‐3α, in mammalian brain.
Do‐Not‐Resuscitate and Do‐Not‐Hospitalize Directives of Persons Admitted to Skilled Nursing Facilities Under the Medicare Benefit
Authors: Levy Cari R. , Fish Ronald , Kramer Andrew 
Published: November 2005

Objectives: To determine prevalence and factors associated with do‐not‐resuscitate (DNR) and do‐not‐hospitalize (DNH) directives of residents admitted under the Medicare benefit to a skilled nursing facility (SNF). To explore geographic variation in use of DNR and DNH orders.Design: Retrospective cohort study.Setting: Nursing homes in the United States.Participants: Medicare admissions to SNFs in 2001 (n=1,962,742).Measurements: Logistic regression was used to select factors associated with DNR and DNH directives and state variation in their use.Results: Thirty‐two percent of residents had DNR directives, whereas less than 2% had DNH directives. Factors associated with having a DNR or DNH directive at the resident level included older age, cognitive impairment, functional dependence, and Caucasian ethnicity. African‐American, Hispanic, Asian, and North American Native residents were all significantly less likely than Caucasian residents to have DNR (adjusted odds ratio (OR)=0.35, 0.51, 0.61, and 0.62, respectively) or DNH (adjusted OR=0.26, 0.41, 0.43, and 0.67, respectively) directives. In contrast, residents in rural and government facilities were more likely to have DNR or DNH directives. After controlling for resident and facility characteristics, significant variation between states existed in the use of DNR and DNH directives.Conclusion: Ethnic minorities are less likely to have DNR and DNH directives even after controlling for disease status, demographic, facility, and geographic characteristics. Wide variation in the likelihood of having DNR and DNH directives between states suggests a need for better‐standardized methods for eliciting the care preferences of residents admitted to SNFs under the Medicare benefit.
Assembly of the Hap2p/Hap3p/Hap4p/Hap5p-DNA Complex in
Saccharomyces cerevisiae
Authors: McNabb David S. , Pinto Inés 
Published: November 2005

ABSTRACT

The CCAAT-binding factor (CBF) is an evolutionarily conserved multimeric transcriptional activator in eukaryotes. In
Saccharomyces cerevisiae
, the CCAAT-binding factor is composed of four subunits, termed Hap2p, Hap3p, Hap4p, and Hap5p. The Hap2p/Hap3p/Hap5p heterotrimer is the DNA-binding component of the complex that binds to the consensus 5′-CCAAT-3′ sequence in the promoter of target genes. The Hap4p subunit contains the transcriptional activation domain necessary for stimulating transcription after interacting with Hap2p/Hap3p/Hap5p. In this report, we demonstrate that Hap2p, Hap3p, and Hap5p assemble via a one-step pathway requiring all three subunits simultaneously, as opposed to the mammalian CCAAT-binding factor which has been shown to assemble via a two-step pathway with CBF-A (Hap3p homolog) and CBF-C (Hap5p homolog) forming a stable dimer before CBF-B (Hap2p homolog) can interact. We have also found that the interaction of Hap4p with Hap2p/Hap3p/Hap5p requires DNA binding as a prerequisite. To further understand the protein-protein and protein-DNA interactions of this transcription factor, we identified the minimal domain of Hap4p necessary for interaction with the Hap2p/Hap3p/Hap5p-DNA complex, and we demonstrate that this domain is sufficient to complement the respiratory deficiency of a
hap4Δ
mutant and activate transcription when fused with the VP16 activation domain. These studies provide a further understanding of the assembly of the yeast CCAAT-binding factor at target promoters and raise a number of questions concerning the protein-protein and protein-DNA interactions of this multisubunit transcription factor.
Comparison of Cell Wall Localization among Pir Family Proteins and Functional Dissection of the Region Required for Cell Wall Binding and Bud Scar Recruitment of Pir1p
Authors: Sumita Toru , Yoko-o Takehiko , Shimma Yoh-ichi , Jigami Yoshifumi 
Published: November 2005

ABSTRACT

We examined the localization of the Pir protein family (Pir1 to Pir4), which is covalently linked to the cell wall in an unknown manner. In contrast to the other Pir proteins, a fusion of Pir1p and monomeric red fluorescent protein distributed in clusters in
pir1
Δ cells throughout the period of cultivation, indicating that Pir1p is localized in bud scars. Further microscopic analysis revealed that Pir1p is expressed inside the chitin rings of the bud scars. Stepwise deletion of the eight units of the repetitive sequence of Pir1p revealed that one unit is enough for the protein to bind bud scars and that the extent of binding of Pir1p to the cell wall depends on the number of these repetitive units. The localization of a chimeric Pir1p in which the repetitive sequence of Pir1p was replaced with that of Pir4p revealed the functional role of the different protein regions, specifically, that the repetitive sequence is required for binding to the cell wall and that the C-terminal sequence is needed for recruitment to bud scars. This is the first report that bud scars contain proteins like Pir1p as internal components.
A Chitin Synthase and Its Regulator Protein Are Critical for Chitosan Production and Growth of the Fungal Pathogen
Cryptococcus neoformans
Authors: Banks Isaac R. , Specht Charles A. , Donlin Maureen J. , Gerik Kimberly J. , Levitz Stuart M. , Lodge Jennifer K. 
Published: November 2005

ABSTRACT

Chitin is an essential component of the cell wall of many fungi. Chitin also can be enzymatically deacetylated to chitosan, a more flexible and soluble polymer.
Cryptococcus neoformans
is a fungal pathogen that causes cryptococcal meningoencephalitis, particularly in immunocompromised patients. In this work, we show that both chitin and chitosan are present in the cell wall of vegetatively growing
C. neoformans
yeast cells and that the levels of both rise dramatically as cells grow to higher density in liquid culture.
C. neoformans
has eight putative chitin synthases, and strains with any one chitin synthase deleted are viable at 30°C. In addition,
C. neoformans
genes encode three putative regulator proteins, which are homologs of
Saccharomyces cerevisiae
Skt5p. None of these three is essential for viability. However, one of the chitin synthases (Chs3) and one of the regulators (Csr2) are important for growth. Cells with deletions in either
CHS3
or
CSR2
have several shared phenotypes, including sensitivity to growth at 37°C. The similarity of their phenotypes also suggests that Csr2 specifically regulates chitin synthesis by Chs3. Lastly, both
chs3Δ
and the
csr2Δ
mutants are defective in chitosan production, predicting that Chs3-Csr2 complex with chitin deacetylases for conversion of chitin to chitosan. These data suggest that chitin synthesis could be an excellent antifungal target.
Functional Analysis of the Polyketide Synthase Genes in the Filamentous FungusGibberella zeae(AnamorphFusarium graminearum)
Authors: Gaffoor Iffa , Brown Daren W. , Plattner Ron , Proctor Robert H. , Qi Weihong , Trail Frances 
Published: November 2005

ABSTRACTPolyketides are a class of secondary metabolites that exhibit a vast diversity of form and function. In fungi, these compounds are produced by large, multidomain enzymes classified as type I polyketide synthases (PKSs). In this study we identified and functionally disrupted 15 PKS genes from the genome of the filamentous fungusGibberella zeae. Five of these genes are responsible for producing the mycotoxins zearalenone, aurofusarin, and fusarin C and the black perithecial pigment. A comprehensive expression analysis of the 15 genes revealed diverse expression patterns during grain colonization, plant colonization, sexual development, and mycelial growth. Expression of one of the PKS genes was not detected under any of 18 conditions tested. This is the first study to genetically characterize a complete set of PKS genes from a single organism.
Highly Efficient Tandem Affinity Purification of Trypanosome Protein Complexes Based on a Novel Epitope Combination
Authors: Schimanski Bernd , Nguyen Tu N. , Günzl Arthur 
Published: November 2005

ABSTRACT

Tandem affinity purification (TAP) allows for rapid and efficient purification of epitope-tagged protein complexes from crude extracts under native conditions. The method was established in yeast and has been successfully applied to other organisms, including mammals and trypanosomes. However, we found that the original method, which is based on the TAP tag, consisting of a duplicate protein A epitope, a tobacco etch virus protease cleavage site, and the calmodulin-binding peptide (CBP), did not yield enough recovery of transcription factor SNAPc (for small nuclear RNA-activating protein complex) from crude trypanosome extracts for protein identification. Specifically, the calmodulin affinity chromatography step proved to be inefficient. To overcome this problem, we replaced CBP by the protein C epitope (ProtC) and termed this new epitope combination PTP tag. ProtC binds with high affinity to the monoclonal antibody HPC4, which has the unique property of requiring calcium for antigen recognition. Thus, analogous to the calcium-dependent CBP-calmodulin interaction, ProtC-tagged proteins can be released from immobilized HPC4 by a chelator of divalent cations. While this property was retained, epitope substitution improved purification in our experiments by eliminating the inefficiency of calmodulin affinity chromatography and by providing an alternative way of elution using the ProtC peptide in cases where EGTA inactivated protein function. Furthermore, HPC4 allowed highly sensitive and specific detection of ProtC-tagged proteins after protease cleavage. Thus far, we have successfully purified and characterized the U1 small nuclear ribonucleoprotein particle, the transcription factor complex TATA-binding protein related factor 4 (TRF4)/SNAPc/transcription factor IIA (TFIIA), and RNA polymerase I of
Trypanosoma brucei
.
How do writers view usability information? A case study of a developing documentation writer
Authors: Sullivan Patricia A. , Porter James E. 
Published: November 2005

As Dieli (1989) notes, writers sometimes have trouble focusing their concerns into questions that usability groups can test. As teachers of future documentation writers, we have observed that writers also have trouble turning the results of those usability tests into strategies for document revision. Our first investigation into these issues—see Sullivan & Porter (1990)—described a class of fifteen professional writing students employing usability information to write computer documentation. That study indicated that the writer's use of information is guided by that writer's rhetorical orientation, particularly his/her view of the audience/user. Though all the writers in the study conducted the same type of usability test (modeled after Atlas' “user edit”—see Atlas, 1981), they interpreted their test results in different ways.
This investigation continues the Sullivan & Porter (1990) study using a longitudinal case study of one professional writer, called “Max.” This follow-up study aims to probe how the writer's rhetorical orientation guides that writer's interpretation of usability test results.

We take a slightly uncommon view of usability. We have opted to focus on the writer's view of users' actions—both what is noticed and how it is interpreted. Typically, usability studies have examined the interaction between texts/systems and readers/users (see McDonald & Schvaneveldt, 1988; Ramey, 1988; Rubens & Rubens, 1988), subordinating the important variable of how the writer interprets and uses results. Although both Sullivan (March, 1985) and Schriver (1987) suggest that writers can be trained to successfully use user information in revising documents they do not author, usability studies still have not examined how writers view the findings from usability studies run
on their own work
.

Our study examines how, and to what degree, one writer's rhetorical orientation filters results from usability tests.

what is his rhetorical orientation?

what value does he place on, and how does he classify and apply, usability test information?
The role of indexing in technical communication
Authors: Northrop Mary Jane 
Published: November 2005

The success of a technical document depends heavily on the index. The task of indexing a technical document often cannot begin until insufficient time remains to do a good job. However, for many users of the document, a good index is mandatory to its usability.
A good index is especially crucial for technical documents because readers tend to look up specific topics instead of reading the document from cover to cover. A poor index often frustrates readers and taints their view of the entire document.
To create a good index, you have to know what makes a good index, understand the indexing tools available, and follow the steps to producing a good index. Additionally, you must make many process decisions that affect the quality of the final index you produce. The skills and processes for creating a good index are similar to those required for most technical communication projects: methodical approach, knowledge of the users' needs, collaboration with colleagues, and testing.
This paper discusses how to create a good index and how to make decisions about using personal computer word-processing tools to create an index. It also discusses the feasibility of creating maintainable indexes using these tools.
User-centeredness, situatedness, and designing the media of computer documentation
Authors: Johnson Bob 
Published: November 2005

User-centeredness has become a concept of much interest in a number of fields. Systems engineering, architecture, usability research and computer documentation, to name a few, are all areas of study which have, to one degree or another, adopted the terminology of user-centered philosophy in order to come to grips with the problem of how to design for users' needs.
While there is much positive to be said about applying user-centered concepts to any discipline that wishes to pursue it, there is also a danger that the concept and philosophy of user-centered design could become, at best, empty rhetoric, and, at worst, fuel for lip service that could serve to undermine the humanitarian goals of a user-centered ethic.
One concept which has already suffered a similar fate is that of “problem-solving.” Problem-solving has become, essentially, a hollow term when used by certain disciplines or institutions. For example, it is commonplace to hear representatives of business and industry refer to the need for 'good problem-solvers' in the world of business.
One answer to this call has been the adoption of the terminology of problem-solving by the business curricula of many college and university business schools. At least one critic of current business school curricula has mentioned that theories of problem-solving have been diluted by the time they reach students (1). My own experience in teaching business writing at two universities has shown similar characteristics. Many of the business majors want to refer to themselves as “good problem-solvers” in their job application letters, but when asked to elaborate on or give an example of this, they often have simplified or inaccurate ideas of what should constitute an understanding of rich and powerful strategies.
Certainly, the research and theory-building of Simon and Newell (2), or G. Polya (3) is applicable to the academic and workplace settings of business, but somehow the terminology of the theory lost its relevance during the translation.
My purpose in this article is to discuss how user-centered computer documentation can avoid a similar fate. At present I fear our direction is veering in the direction of such a fate, and that one step toward correcting our course is to develop a clear theoretical understanding of what user-centeredness means to documentation. This means that although there may be a tacit theory which underlies current applications, it is important to make the theory visible, and thereby illuminate the gaps that may exist.
In addition, my focus will also be upon the contribution that user-centered theory can bring to our understanding of how to design for the different media of computer documentation. As we all know, online and hypermedia documentation is becoming a central charge of our profession, and user-centered theory can go a long way in helping us understand the similarities and differences among the different media.
Putting a local information system online using pre-packaged software
Authors: Dautermann Jennie 
Published: November 2005

Many small organizations have the need for information storage and retrieval systems which they dream of putting on-line for ease of access. Such a project designed with modest equipment and pre-packaged software can achieve three important objectives:

allow users to design their own access tools

clarify the information needs of a community

improve information access.

These goals may be sufficient in themselves in many situations, but they may also become interim steps which prepare users for involvement in larger institutional projects at some later time by enabling them to think through their information needs in concrete and manageable terms.
During an information management project with the nursing department of a Midwest community hospital, a standard PC data base became the vehicle for introducing each of these benefits to the department and for preparing the department to participate in a larger main frame project already in progress in their hospital.