bluuebunny/crossref_metadata_2025 huggingface dataset:
The sup-pf-2 mutations of Chlamydomonas alter the activity of the outer dynein arms by modification of the gamma-dynein heavy chain.
Authors: Rupp G , O'Toole E , Gardner L C , Mitchell B F , Porter M E
Published: May 2004

The sup-pf-2 mutation is a member of a group of dynein regulatory mutations that are capable of restoring motility to paralyzed central pair or radial spoke defective strains. Previous work has shown that the flagellar beat frequency is reduced in sup-pf-2, but little else was known about the sup-pf-2 phenotype (Huang, B., Z. Ramanis, and D.J.L. Luck. 1982. Cell. 28:115-125; Brokaw, C.J., and D.J.L. Luck. 1985. Cell Motil. 5:195-208). We have reexamined sup-pf-2 using improved biochemical and structural techniques and by the analysis of additional sup-pf-2 alleles. We have found that the sup-pf-2 mutations are associated with defects in the outer dynein arms. Biochemical analysis of sup-pf-2-1 axonemes indicates that both axonemal ATPase activity and outer arm polypeptides are reduced by 40-50% when compared with wild type. By thin-section EM, these defects correlate with an approximately 45% loss of outer dynein arm structures. Interestingly, this loss is biased toward a subset of outer doublets, resulting in a radial asymmetry that may reflect some aspect of outer arm assembly. The defects in outer arm assembly do not appear to result from defects in either the outer doublet microtubules or the outer arm docking structures, but rather appear to result from defects in outer dynein arm components. Analysis of new sup-pf-2 mutations indicates that the severity of the outer arm assembly defects varies with different alleles. Complementation tests and linkage analysis reveal that the sup-pf-2 mutations are alleles of the PF28/ODA2 locus, which is thought to encode the gamma-dynein heavy chain subunit of the outer arm. The sup-pf-2 mutations therefore appear to alter the activity of the outer dynein arms by modification of the gamma-dynein heavy chain.
Infection Control Measures for Operative Procedures in Severe Acute Respiratory Syndrome–related Patients
Authors: Chee Victor Wei Ter , Khoo Mark Li-Chung , Lee Sow Fong , Lai Yeow Choy , Chin Ngek Mien
Published: May 2004

Background

Singapore reported its first case of Severe Acute Respiratory Syndrome (SARS) in early March 2003 and was placed on the World Health Organization's list of SARS-affected countries on March 15, 2003. During the outbreak, Tan Tock Seng Hospital was designated as the national SARS hospital in Singapore to manage all known SARS patients. Stringent infection control measures were introduced to protect healthcare workers and control intrahospital transmission of SARS. Work-flow processes for surgery were extensively modified.

Methods

The authors describe the development of infection control measures, the conduct of surgical procedures, and the management of high-risk procedures during the SARS outbreak.

Results

Forty-one operative procedures, including 15 high-risk procedures (surgical tracheostomy), were performed on SARS-related patients. One hundred twenty-four healthcare workers had direct contact with SARS patients during these procedures. There was no transmission of SARS within the operating room complex.

Conclusions

Staff personal protection, patient risk categorization, and reorganization of operating room workflow processes formed the key elements for the containment of SARS transmission. Lessons learned during this outbreak will help in the planning and execution of infection control measures, should another outbreak occur.
Remifentanil Directly Activates Human N-methyl-d-aspartate Receptors Expressed in Xenopus laevis Oocytes
Authors: Hahnenkamp Klaus , Nollet Joke , Van Aken Hugo K. , Buerkle Hartmut , Halene Tobias , Schauerte Svenja , Hahnenkamp Anke , Hollmann Markus W. , Strümper Danja , Durieux Marcel E. , Hoenemann Christian W.
Published: May 2004

Background

Clinical studies suggest that intraoperative administration of the clinical remifentanil formulation Ultiva (GlaxoWellcome GmbH & Co, Bad Oldesloe, Germany) increases postoperative pain and postoperative analgesic requirements, but mechanisms remain unclear. N-methyl-D-aspartate (NMDA) receptors are thought to play a major role in development of postoperative pain and opiate tolerance. The authors hypothesized that Ultiva directly stimulates human NMDA receptors.

Methods

To test this hypothesis, the authors expressed human NR1A/NR2A and NR1A/NR2B NMDA receptors in Xenopus laevis oocytes by injection of messenger RNA prepared in vitro. After protein expression, they used a two-electrode voltage clamp to measure currents induced by NMDA receptor agonists and opioids.

Results

Noninjected cells were unresponsive to all compounds tested. Glutamate/glycine (1 nM-1 mM each) or Ultiva (0.01 pM-0.1 mM) stimulated NMDA receptors concentration dependently. NR1A/2A EC50 values were 8.0 microM/12 microM for glutamate/glycine and 3.5 nM for Ultiva, and NR1A/2B EC50 values were 3.9 microM/1.9 microM for glutamate/glycine and 0.82 microM for Ultiva. Glycine in combination with Ultiva showed no additive effect compared with Ultiva alone. Ultiva-induced currents were inhibited by MK-801 (pore blocker) but not by 7-CK (glycine antagonist), D-AP5 (glutamate antagonist), or naloxone. Fentanyl (10 microM) did not stimulate NMDA receptors.

Conclusion

These data indicate that Ultiva but not fentanyl stimulates NMDA receptors of different subunit combinations (NR1A/2A, NR1A/2B). The mechanism seems to be allosteric activation of the NMDA receptor.
Differentiating among Hospitals Performing Physiologically Complex Operative Procedures in the Elderly
Authors: Wachtel Ruth E. , Dexter Franklin
Published: May 2004

Background

The authors previously showed how a statewide discharge abstract database could be used to quantify for stakeholders how surgical practices differ among hospitals. The two pediatric hospitals in Iowa differ from other hospitals in Iowa based on their providing a more diverse, comprehensive, and physiologically complex selection of procedures in younger patients. Physiologically complex surgery performed in children aged 0-2 yr has been regionalized to a few high-volume facilities.

Methods

The same inpatient discharge abstract database was used to quantify physiologically complex operative procedures performed throughout Iowa in patients aged 80 yr and older during January through June 2001.

Results

In contrast to earlier results with pediatric patients using the same database, hospitals performing physiologically complex procedures in the elderly could not readily be differentiated from one another based on the numbers and types of procedures performed (P < 0.001 when comparing geriatrics vs. pediatrics in terms of the distributions of numbers of procedures, the distributions of numbers of different types of procedures, or the distributions of numbers of rare procedures performed at different hospitals). Additional analyses showed that one hospital did perform relatively more rare procedures in geriatric patients and had a relatively larger percentage of patients who traveled beyond their local county to reach it.

Conclusions

Results observed for geriatric patients provide further evidence of the validity of these methods and the usefulness of discharge abstract data for comparing surgical practices among facilities. A hospital can use discharge abstract data to assist governmental agencies, charitable organizations, philanthropists, insurers, etc., in appreciating the unique contributions of individual hospitals to surgical care.
The dimerization domain of the HIV‐1 capsid protein binds a capsid protein‐derived peptide: A biophysical characterization
Authors: Garzón María T. , Lidón‐Moya María C. , Barrera Francisco N. , Prieto Alicia , Gómez Javier , Mateu Mauricio G. , Neira José L.
Published: May 2004

The type 1 HIV presents a conical capsid formed by ∼1500 units of the capsid protein, CA. Homodimer‐ization of CA via its C‐terminal domain, CA‐C, constitutes a key step in virion assembly. CA‐C dimerization is largely mediated by reciprocal interactions between residues of its second α‐helix. Here, we show that an N‐terminal‐acetylated and C‐terminal–amidated peptide, CAC1, comprising the sequence of the CA‐C dimerization helix plus three flanking residues at each side, is able to form a complex with the entire CA‐C domain. Thermal denaturation measurements followed by circular dichroism (CD), NMR, and size‐exclusion chromatography provided evidence of the interaction between CAC1 and CA‐C. The apparent dissociation constant of the heterocomplex formed by CA‐C and CAC1 was determined by several biophysical techniques, namely, fluorescence (using an anthraniloyl‐labeled peptide), affinity chromatography, and isothermal titration calorimetry. The three techniques yielded similar values for the apparent dissociation constant, in the order of 50 μM. This apparent dissociation constant was only five times higher than was the dissociation constant of both CA‐C and the intact capsid protein homodimers (10 μM).
Modulation of the structural integrity of helix F in apomyoglobin by single amino acid replacements
Authors: Picotti Paola , Marabotti Anna , Negro Alessandro , Musi Valeria , Spolaore Barbara , Zambonin Marcello , Fontana Angelo
Published: May 2004

The conformational features of native and mutant forms of sperm‐whale apomyoglobin (apoMb) at neutral pH were probed by limited proteolysis experiments utilizing up to eight proteases of different substrate specificities. It was shown that all proteases selectively cleave apoMb at the level of chain segment 82–94 (HEAELKPLAQSHA), encompassing helix F in the X‐ray structure of the holo form of the native protein; for example, thermolysin cleaves the Pro 88–Leu 89 peptide bond. These results indicate that helix F is highly flexible or largely disrupted in apoMb. Because helix F contains the helix‐breaking Pro 88 residue, we propose that helix F is kept in place in the native holo protein by a variety of helix–heme stabilizing interactions. To modulate the stability of helix F, the Pro88Ala and Pro88Gly mutants were prepared by site‐directed mutagenesis, and their conformational properties investigated by both far‐UV circular dichroism spectroscopy and limited proteolysis. The helix content of the Pro88Ala mutant was somewhat enhanced with respect to that of both native and Pro88Gly mutant, as expected from the fact that Ala is the strongest helix inducer among the 20 amino acid residues. The rate of limited proteolysis of the three apoMb variants by thermolysin and proteinase K was in the order native > Pro88Gly >> Pro88Ala, in agreement with the scale of helix propensity of Ala, Gly, and Pro. The possible role of the flexible/unfolded chain segment 82–94 for the function and fate of apoMb at the cellular level is discussed.
A novel and conserved pocket of human κ‐Fab fragments: Design, synthesis, and verification of directed affinity ligands
Authors: Carredano Enrique , Baumann Herbert , Grönberg Anna , Norrman Nils , Glad Gunnar , Zou Jinyu , Ersoy Oguz , Steensma Elles , Axén Andreas
Published: May 2004

Antibodies of type IgG may be divided into two classes, called λor κ, depending on the type of light chain. We have identified a conserved pocket between the two domains CH1 and CL of human IgG κ‐Fab, which is not present in the λ type. This pocket was used as a target docking site with the purpose of exploring the possibilities of designing affinity ligands that could function as such even after immobilization to gel. The idea of the design arose mainly from the results of the saturated transfer difference (STD‐NMR) screening of 46 compounds identified by means of virtual docking of 60 K diverse compounds from the Available Chemicals Directory (ACD). Surface plasmon resonance (SPR) was used as an alternative method to monitor binding in solution. A total of 24 compounds belonging to a directed library were designed, synthesized, and screened in solution. They consist essentially of an amino acid condensed to a N,N′‐methylated phenyl urea. STD‐NMR results suggest that a small hydrophobic side chain in the condensed amino acid promotes binding, whereas a hydroxyl‐group–containing side chain implies absence of STD‐NMR signals. Three compounds of the directed library were immobilized and evaluated as chromatographic probes. In one case, using D‐Pro as the condensed amino acid, columns packed with ligand‐coupled Sepharose (Amersham Biosciences) retained two different monoclonal samples of κ‐Fab fragments with different variable regions, whereas a sample of monoclonal λ‐Fab fragments was not retained under similar chromatographic conditions.
The structure of Ski8p, a protein regulating mRNA degradation: Implications for WD protein structure
Authors: Madrona A. Yarrow , Wilson David K.
Published: May 2004

Ski8p is a 44‐kD protein that primarily functions in the regulation of exosome‐mediated, 3′→ 5′ degradation of damaged mRNA. It does so by forming a complex with two partner proteins, Ski2p and Ski3p, which complete a complex that is capable of recruiting and activating the exosome/Ski7p complex that functions in RNA degradation. Ski8p also functions in meiotic recombination in complex with Spo11 in yeast. It is one of the many hundreds of primarily eukaryotic proteins containing tandem copies of WD repeats (also known as WD40 or β‐transducin repeats), which are short ∼40 amino acid motifs, often terminating in a Trp–Asp dipeptide. Genomic analyses have demonstrated that WD repeats are found in 1%–2% of proteins in a typical eukaryote, but are extremely rare in prokaryotes. Almost all structurally characterized WD‐repeat proteins are composed of seven such repeats and fold into seven‐bladed β propellers. Ski8p was thought to contain five WD repeats on the basis of primary sequence analysis implying a five‐bladed propeller. The 1.9 Å crystal structure unexpectedly exhibits a seven‐bladed propeller fold with seven structurally authentic WD repeats. Structure‐based sequence alignments show additional sequence diversity in the two undetected repeats. This demonstrates that many WD repeats have not yet been identified in sequences and also raises the possibility that the seven‐bladed propeller may be the predominant fold for this family of proteins.
Implementation Studies: Time for a Revival? Personal Reflections on 20 Years of Implementation Studies
Authors: Barrett Susan M.
Published: May 2004

This paper presents a review of three decades of implementation studies and is constructed in the form of a personal reflection. The paper begins with a reflection upon the context within which the bookPolicy and Actionwas written, a time when both governments and policy analysts were endeavouring to systematize and improve the public decision‐making process and to place such decision‐making within a more strategic framework. The review ends with a discussion about how public policy planning has changed in the light of public services reform strategies. It is suggested that as a result of such reforms, interest in the processes of implementation have perhaps been superseded by a focus upon change management and performance targets. It is further argued that this has resulted in the reassertion of normative, top‐down processes of policy implementation. The paper raises points that are important ones and indeed are reflected throughout all four papers in the symposium issue. These are: (1) the very real analytical difficulties of understanding the role of bureaucratic discretion and motivation; (2) the problem of evaluating policy outcomes; and (3) the need to also focus upon micro political processes that occur in public services organizations. In conclusion, the paper emphasizes the continued importance of implementation studies and the need for policy analysts to understand what actually happens at policy recipient level.
A Model of Learned Implementation
Authors: Schofield Jill
Published: May 2004

The majority of the literature concerning the implementation of public policy assumes that public managers can carry out new policy initiatives regardless of the behavioural, cognitive or technical demands that the introduction of such policies may make upon them. There has been a tendency to assume that managers actually have the detailed technical knowledge by which to enact such new policies. The paper proposes that in effect, public managers have to learn a range of often new and detailed techniques in order to implement what are often ambiguous policy directives. Drawing on data gathered from the introduction of capital investment appraisal in the British National Health Service, a model of Learned Implementation is presented that describes one way in which public managers can learn to enact new policy initiatives. Using a mix of six organizational processes and variables, the model demonstrates how learning occurs and is used to solve the problems that are inherent in the introduction of new policy initiatives. The model further describes how the managers routinize these solutions into job tasks and procedures and hence a policy initiative is operationalized. The paper concludes with a discussion about the difficulties of predicting the operational consequences of new policy initiatives and raises questions about knowledge, ability and capability in the implementation of public policy.
Aspen lichens in agricultural and forest landscapes: the importance of habitat quality
Authors: Hedenås Henrik , Ericson Lars
Published: May 2004

The amount of aspen Populus tremula, has declined in the boreal forest landscape. This decline is especially marked in young and intermediate stands due to the lack of regeneration. Aspen regeneration is nowadays mainly restricted to abandoned agricultural land. The decrease of aspen is of particular concern as it has more host‐specific species than any other boreal tree species. The main question addressed is whether regenerating aspen stands in agricultural habitats can compensate for the deficiency of young stands in the forest. Data on epiphytic macrolichens show that cyanolichens increased, in number and frequency, with stand age in the forest landscape, and that there was a striking difference in species composition between stands in the two landscapes. Lichens with cyanobacterial and green‐algal photobionts dominated in the forest and agricultural stands, respectively. Notably, cyanolichens were not found in stands younger than 50 yr in the forest, and stands younger than 100 yr in the agricultural landscape. This difference between the landscapes cannot be explained by stand age, stand size or isolation. Instead, differences in habitat quality, due to differences in the physical environment associated with the presence of conifers in the older forest stands, appear to be involved. We suggest that in order to conserve cyanolichens that are confined to aspen, active management practices have to be adopted that promote the regeneration of aspen in the forest landscape, and the establishment of conifers in areas where aspen regeneration is confined to the agricultural landscape. In addition, until new aspen stands with appropriate physical environments have been established, these measures must be combined with the preservation of existing old‐growth stands, which can provide appropriate source populations.
Cathepsin L‐deficient mice exhibit abnormal skin and bone development and show increased resistance to osteoporosis following ovariectomy
Authors: Potts Wendy , Bowyer Jonathan , Jones Huw , Tucker David , Freemont Anthony J. , Millest Andrew , Martin Colin , Vernon Wendy , Neerunjun Diane , Slynn Gillian , Harper Fiona , Maciewicz Rose
Published: May 2004

The role of cathepsin L in normal physiological processes was assessed using cathepsin L homozygous knockout mice (B6;129‐Ctsltm1Alpk). These mice were generated using gene targeting in embryonic stem cells. Null mice fail to express mRNA and protein to cathepsin L. They developed normally and were fertile. The distinct phenotypic change exhibited was a progressive hair loss, culminating in extensive alopecia by 9 months of age. Histological analysis of the skin from homozygous mice revealed diffuse epithelial hyperplasia, hypotrichosis, hair shaft fragmentation and utricle formation. These findings provide evidence that cathepsin L is involved in the regulation of epithelial cell proliferation and differentiation in the skin. In addition, the role of cathepsin L in bone remodelling was evaluated. Using bone histomorphometric measurements, trabecular, but not cortical, bone volume was found to be significantly decreased in the cathepsin L heterozygote and homozygote mice compared to the wild‐type mice. Following ovariectomy, it was observed that loss of trabecular bone, the most metabolically active component of bone, occurred to a lesser extent in homozygote, and heterozygote mice, than was seen in wild‐type mice. These observations suggest that cathepsin L is likely to have a role in controlling bone turnover during normal development and in pathological states.
Reduced incidence of gastroduodenal ulcers associated with lumiracoxib compared with ibuprofen in patients with rheumatoid arthritis
Authors: Kivitz A. J. , Nayiager S. , Schimansky T. , Gimona A. , Thurston H. J. , Hawkey C.
Published: May 2004

Background : Lumiracoxib (Prexige; Novartis Pharma AG, Basel, Switzerland) is a cyclooxygenase‐2 selective inhibitor associated with improved gastrointestinal safety compared with nonsteroidal anti‐inflammatory drugs, in patients with osteoarthritis.

Aim : To compare the gastroduodenal safety of lumiracoxib with ibuprofen and celecoxib in patients with rheumatoid arthritis.

Methods : A total of 893 patients with rheumatoid arthritis were randomized to lumiracoxib 400 mg once daily, lumiracoxib 800 mg once daily, ibuprofen 800 mg three times daily or celecoxib 200 mg twice daily for 13 weeks, in a double‐blind randomised controlled clinical trial. The primary endpoint was the cumulative incidence of gastroduodenal ulcers over 13 weeks.

Results : The incidence of gastroduodenal ulcers ≥3 mm with lumiracoxib 400 mg once daily (2.8%) or lumiracoxib 800 mg once daily (4.3%) was significantly lower than with ibuprofen (13.6%, all P < 0.01) and not different from celecoxib (1.9%). The incidence of adverse events was similar for lumiracoxib 400, 800 mg and celecoxib (78, 75 and 77%, respectively) and higher with ibuprofen (86%). Discontinuation for adverse events was highest for ibuprofen (12.5% vs. 7.9–8.8% for the other groups).

Conclusions : Lumiracoxib demonstrated gastroduodenal safety superior to ibuprofen and similar to celecoxib in patients with rheumatoid arthritis.
Postoperative complications in the first 24 hours: a general surgery audit
Authors: Zeitz Kathryn , McCutcheon Helen , Albrecht Annette
Published: May 2004

Background.  Traditionally, the purpose of routine postoperative surveillance has been to detect postoperative complications. The literature reports well‐documented, procedure‐specific postoperative complication rates. However, there are no reports detailing the prevalence of postoperative complications in general surgical ward settings, where nurses care for patients following a variety of surgical procedures.

Aims.  This paper reports an audit of the frequency and type of postoperative complications in a general surgical population occurring in the first 24 hours postoperatively.

Method.  A patient record audit was undertaken for all postoperative patients who returned to two general surgical wards. This was conducted sequentially, involving a 4 week data collection phase in each participating ward during 2001.

Results.  The audit sample comprised 144 patient records with an average patient age of 54 years. Statistically significant results included the rate of postoperative nausea and vomiting of 37·5% (n = 54), and 17% (n = 25) of patients experiencing another ‘clinical event’.

Limitations.  The findings reflect only those complications recorded/documented in postoperative patients’ records, and cannot be generalized beyond the sample and setting.

Conclusions.  Postoperative patients cared for on general surgical wards experienced a high level of nausea and vomiting, while the occurrence of life‐threatening complications was small.
Women's experience of endometriosis
Authors: Denny Elaine
Published: May 2004

Background.  Endometriosis is a chronic disease affecting between 5% and 15% of women of reproductive age. Diagnosis can be delayed for many years, despite the existence of severe pain, and women often find that their experiences are not taken seriously by health professionals. Little research has been conducted into how endometriosis affects their lives.

Aim.  The aim of this paper is to report a study exploring women's experience of living with endometriosis.

Method.  A qualitative approach was used, in which women were asked to relate their stories starting from the first experience of symptoms that they associated with endometriosis. Key areas to be followed‐up during interviews were identified by women with endometriosis who were not participants. Fifteen semi‐focused interviews were conducted, and thematic and content analysis were carried out using the identified key areas, and themes elicited from initial analysis of the interview transcripts. From these two processes the final themes of delay in diagnosis, pain, dyspareunia, treatment, work and social relationships, the workplace, and the future emerged.

Findings.  Despite the existence of severe pain, often described as ‘intense’ or ‘overwhelming’, women experienced delay in receiving a diagnosis of endometriosis, and their symptoms were frequently trivialized or normalized. This, and the limited effectiveness of treatments, affected relationships with partners and family, work, and sexual relations, although individual experiences in each area were diverse.

Conclusion.  The experience of endometriosis pervades all aspects of a woman's life. This experience is compounded by the side effects of many treatments. Women with this disease need to be taken seriously, and not have their pain trivialized or normalized. Nurses are often well‐placed to assist patients in receiving sensitive and appropriate care.
Angiotensin‐converting enzyme inhibition studies by natural leech inhibitors by capillary electrophoresis and competition assay
Authors: Deloffre Laurence , Sautiere Pierre‐Eric , Huybrechts Roger , Hens Korneel , Vieau Didier , Salzet Michel
Published: May 2004

A protocol to follow the processing of angiotensin I into angiotensin II by rabbit angiotensin‐converting enzyme (ACE) and its inhibition by a novel natural antagonist, the leech osmoregulator factor (LORF) using capillary zonal electrophoresis is described. The experiment was carried out using the Beckman PACE system and steps were taken to determine (a) the migration profiles of angiotensin and its yielded peptides, (b) the minimal amount of angiotensin II detected, (c) the use of different electrolytes and (d) the concentration of inhibitor. We demonstrated that LORF (IPEPYVWD), a neuropeptide previously found in leech brain, is able to inhibit rabbit ACE with an IC50 of 19.8 µm. Interestingly, its cleavage product, IPEP exhibits an IC50 of 11.5 µm. A competition assay using p‐benzoylglycylglycylglycine and insect ACE established that LORF and IPEP fragments are natural inhibitors for invertebrate ACE. Fifty‐four percent of insect ACE activity is inhibited with 50 µm IPEP and 35% inhibition with LORF (25 mm). Extending the peptide at both N‐ and C‐terminus (GWEIPEPYVWDES) and the cleavage of IPEP in IP abolished the inhibitory activity of both peptides. Immunocytochemical data obtained with antisera raised against LORF and leech ACE showed a colocalization between the enzyme and its inhibitor in the same neurons. These results showed that capillary zonal electrophoresis is a useful technique for following enzymatic processes with small amounts of products and constitutes the first evidence of a natural ACE inhibitor in invertebrates.
Survey of the Botrytis cinerea chitin synthase multigenic family through the analysis of six euascomycetes genomes
Authors: Choquer Mathias , Boccara Martine , Gonçalves Isabelle R. , Soulié Marie‐Christine , Vidal‐Cros Anne
Published: May 2004

We describe a strategy for systematic amplification of chitin synthase genes (chs) in the filamentous ascomycetes plant‐pathogen Botrytis cinerea using PCR with multiple degenerate primers designed on specific and conserved sequence motifs. Eight distinct chs genes were isolated, named Bcchs I, II, IIIa, IIIb, IV, V, VI and VII. They probably constitute the entire chs multigenic family of this fungus, as revealed by careful analysis of six euascomycetes genomes. Bcchs I, IIIa, IIIb, IV and VI genes were subjected to DNA walking and their deduced amino acid sequences were compared by hydrophobic cluster analysis (HCA) to localize putative residues critical for CHS activity. HCA also enabled us to highlight three different transmembrane topologies of the CHS membranous isoenzymes. We found that the N‐terminal region of the BcCHSI isoenzyme, and its orthologues in other euascomycetes, probably contain folded peptide motifs with conserved tyrosine residues. Their putative role is discussed. The BcCHSVII isoenzyme appeared to belong to a new class of CHS orthologues that was demonstrated by phylogenetic study to branch apart from division 1 and 2 of CHS.
Covalent activation of heart AMP‐activated protein kinase in response to physiological concentrations of long‐chain fatty acids
Authors: Clark Hilary , Carling David , Saggerson David
Published: May 2004

Rat hearts were perfused for 1 h with 5 mm glucose with or without palmitate or oleate at concentrations characteristic of the fasting state. The inclusion of fatty acids resulted in increased activities of the α‐1 or the α‐2 isoforms of AMP‐activated protein kinase (AMPK), increased phosphorylation of acetyl‐CoA carboxylase and a decrease in the tissue content of malonyl‐CoA. Activation of AMPK was not accompanied by any changes in the tissue contents of ATP, ADP, AMP, phosphocreatine or creatine. Palmitate increased phosphorylation of Thr172 within AMPK α‐subunits and the activation by palmitate of both AMPK isoforms was abolished by protein phosphatase 2C leading to the conclusion that exposure to fatty acid caused activation of an AMPK kinase or inhibition of an AMPK phosphatase. In vivo, 24 h of starvation also increased heart AMPK activity and Thr172 phosphorylation of AMPK α‐subunits. Perfusion with insulin decreased both α‐1 and α‐2 AMPK activities and increased malonyl‐CoA content. Palmitate prevented both of these effects. Perfusion with epinephrine decreased malonyl‐CoA content without an effect on AMPK activity but prevented the activation of AMPK by palmitate. The concept is discussed that activation of AMPK by an unknown fatty acid‐driven signalling process provides a mechanism for a ‘feed‐forward’ activation of fatty acid oxidation.
Kinetic studies and molecular modelling attribute a crucial role in the specificity and stereoselectivity of penicillin acylase to the pair ArgA145‐ArgB263
Authors: Guncheva Maya , Ivanov Ivaylo , Galunsky Boris , Stambolieva Nicolina , Kaneti Jose
Published: May 2004

Kinetic experiments with a substrate series of phenylacetyl‐arylamides reveal that at least one polar group in the amine moiety is required for the proper orientation of the substrate in the large nucleophile‐binding subsite of penicillin acylase of Escherichia coli. Quantum mechanical molecular modelling of enzyme–substrate interactions in the enzyme active site shows that in the case of substrates lacking local symmetry, the productive binding implies two nonsymmetrical arrangements with respect to the two positively charged guanidinium residues of ArgA145 and ArgB263. This indicates a crucial role of the specified arginine pair in the substrate‐ and stereoselectivity of penicillin acylase.
The conformational stability of theStreptomyces coelicolorhistidine‐phosphocarrier protein
Authors: Neira José L. , Gómez Javier
Published: May 2004

Thermodynamic parameters describing the conformational stability of the histidine‐containing phosphocarrier protein fromStreptomyces coelicolor, scHPr, have been determined by steady‐state fluorescence measurements of isothermal urea‐denaturations, differential scanning calorimetry at different guanidinium hydrochloride concentrations and, independently, by far‐UV circular dichroism measurements of isothermal urea‐denaturations, and thermal denaturations at fixed urea concentrations. The equilibrium unfolding transitions are described adequately by the two‐state model and they validate the linear free‐energy extrapolation model, over the large temperature range explored, and the urea concentrations used. At moderate urea concentrations (from 2 to 3 m), scHPr undergoes both high‐ and low‐temperature unfolding. The free‐energy stability curves have been obtained for the whole temperature range and values of the thermodynamic parameters governing the heat‐ and cold‐denaturation processes have been obtained. Cold‐denaturation of the protein is the result of the combination of an unusually high heat capacity change (1.4 ± 0.3 kcal·mol−1·K−1, at 0 murea, being the average of the fluorescence, circular dichroism and differential scanning calorimetry measurements) and a fairly low enthalpy change upon unfolding at the midpoint temperature of heat‐denaturation (59 ± 4 kcal·mol−1, the average of the fluorescence, circular dichroism and differential scanning calorimetry measurements). The changes in enthalpy (mΔHi), entropy (mΔSi) and heat capacity (mΔCpi), which occur upon preferential urea binding to the unfolded state vs. the folded state of the protein, have also been determined. ThemΔHiand themΔSiare negative at low temperatures, but as the temperature is increased,mΔHimakes a less favourable contribution thanmΔSito the change in free energy upon urea binding. ThemΔCpiis larger than those observed for other proteins; however, its contribution to the global heat capacity change upon unfolding is small.
Sensitivity and specificity of serology in determining recent acute Campylobacter infection
Authors: Taylor B. V. , Williamson J. , Luck J. , Coleman D. , Jones D. , McGregor A.
Published: May 2004

Abstract

Background : The measurement of serum antibodies to Campylobacter spp. has been used to investigate links between prior Campylobacter infections and the development of Guillain−Barre syndrome and its variants. Little is known of the serum antibody response to acute infections in the short‐ or long‐term.

Aims : The aims of the present study were to investigate the normal serum response to an acute Campylobacter infection and the sensitivity and specificity of anti‐Campylobacter antibodies in determining recent Campylo­bacter infection.

Methods : An enzyme‐linked immunosorbent assay (ELISA) method was used to measure serum anti‐Campylobacter immunoglobulin G (IgG), IgA and IgM antibodies. Controls consisted of 420 blood donors without recent gastroenteritis, 25 patients with other gastrointestinal infections, 24 patients with neurological conditions not affecting the peripheral nerves and 19 patients with autoimmune disorders. Three patient groups were assessed: 99 patients with acute Campy­lo­bacter infections, all of whom were tested 3 weeks post‐infection; 69 of these patients tested 3−6 months later; and 74 additional patients tested>20 months post‐­infection. Western blot analysis was performed on controls and patients with high titre anti‐Campylobacter anti­bodies to assess for cross‐reactivity and specificity.

Results : Following acute infections, all antibody classes rose in the majority of but not in all patients, followed by decreasing titres that did not return to baseline levels. Sixteen per cent of enteritis cases did not demonstrate a rise in titres and 9% of cases had significant levels of antibodies>20 months post‐infection. The ELISA used was shown to be highly specific for the detection of Campylobacter antibodies.

Conclusion : The use of Campylobacter‐specific antibody levels as the sole marker of prior infection is an unreli­able method of determining the association between Campylobacter infection and neurological disease. (Intern Med J 2004; 34: 250−258)
Can patients with dementia be assessed at a distance? The use of Telehealth and standardised assessments
Authors: Loh P.K. , Ramesh P. , Maher S. , Saligari J. , Flicker L. , Goldswain P.
Published: May 2004

Abstract

Background : Telehealth could be a medium for the provision of cognitive assessments to distant sites.

Aims : The aims of the present study were to determine the interrater reliability of the Standardized Mini Mental State Exam (SMMSE) and the Geriatric Depression Scale (GDS) through Telehealth as compared to face‐to‐face administration.

Methods : Duplicate interviews of subjects with cross‐over of interview modality were carried out. Twenty patients were interviewed between two sites 11 km apart. Subjects were persons older than 65 years (mean age 82 years) who consented to Telehealth assessments. The outcome measures were the differences in assessment scores between the two media.

Results : The average SMMSE score by remote assessment was 24.0 (range 11.0−30.0) and by direct assessment was 24.3 (range 9.0−30.0). The correlation between direct and remote SMMSE scores was 0.90. The mean difference between direct and remote SMMSE scores was −0.3 (95% confidence interval (CI): −4.6 to 4.0). In 8 of 20 participants (40%) the difference between Telehealth and direct assessments was two points or more on the SMMSE. The average GDS by remote assessment was 6.1 (range 1.0−14.0) and by direct assessment was 5.8 (range 2.0−13.0). The correl­ation between direct and remote GDS scores was 0.78. The mean difference between direct and remote GDS assessment was 0.3 (95% CI: −3.8 to 4.4).

Conclusion : Remote assessments with SMMSE and GDS using Telehealth methods yielded similar results to direct assessments. However, there was a moderate ­difference between face‐to‐face and Telehealth assessments in some subjects, which could influence clinical ­decision‐making. (Intern Med J 2004; 34: 239−242)
New concepts in breast cancer therapy
Authors: Snyder R. D.
Published: May 2004

Abstract

Breast cancer is a common disease in the community. Its incidence is increasing but its mortality is falling. New therapeutic approaches based on a biological understanding of the disease are being investigated to improve the outcome. These include the areas of chemo­prevention and therapy in the adjuvant and advanced settings, and some derive from a better understanding of the biology of breast cancer. New prognostic indicators are being studied to enable adjuvant chemotherapy to be directed towards those most likely to benefit. Trastuzumab was the first of the new targeted therapies to be introduced into routine practice. Several other agents targeting a variety of receptors and cell pathways, such as the epidermal growth factor receptor, the vascular epithelial growth factors and various intracellular tyrosine kinase mediated pathways, are under investigation. Increasing attention is being placed on evidence‐based supportive care, both for control of symptoms such as hot flushes and for psychosocial problems such as anxiety and depression. (Intern Med J 2004; 34: 266−269)
Kennedy's disease: pathogenesis and clinical approaches
Authors: Greenland K. J. , Zajac J. D.
Published: May 2004

Abstract

Kennedy's disease, also known as spinal and bulbar muscular atrophy, is a progressive degenerative con­dition affecting lower motor neurons. It is one of nine neurodegenerative disorders caused by a polyglutamine repeat expansion. Affecting only men, Kennedy's disease is the only one of these conditions that follows an X‐linked mode of inheritance. The causative protein in Kennedy's disease, with a polyglutamine expansion residing in the first N‐terminal domain, is the androgen receptor. Research in this field has made significant advances in recent years, and with the increased understanding of pathogenic mechanisms, feasible approaches to treatments are being investigated. In Kennedy's disease research, the most significant issue to emerge recently is the role of androgens in exacerbating the disease process. On the basis of animal experiments, a viable hypothesis is that higher circulating levels of androgens in men could trigger the degeneration of motor neurons causing this disease, and that lower levels in heterozygous and homozygous women are protective. This is a major issue, as treatment of individuals affected by Kennedy's disease with testosterone has been con­sidered a reasonable therapy by some neurologists. The rationale behind this approach relates to the fact that Kennedy's disease is accompanied by mild androgen insensitivity. It was therefore believed that treatment with high doses of testosterone might compensate for this loss of androgen action, with the added benefit of preventing muscle wasting. The current review provides an overview of recent advances in the field of Kennedy's disease research, including approaches to treatment. (Intern Med J 2004; 34: 279−286)
Assessment and management of inpatients with acute diabetes‐related foot complications: room for improvement
Authors: Lawrence S. M. , Wraight P. R. , Campbell D. A. , Colman P. G.
Published: May 2004

Abstract

Background:  Australian data are currently lacking regarding management guidance, resource usage and outcomes of patients with diabetes requiring hospitali­zation for management of acute foot complications.

Aims:  The aims of the present study were to review hospital admissions for diabetes‐related foot complications and current assessment and management of these complications, and to formulate recommendations for future models of care.

Methods:  A retrospective review of patient records from 1 July 1999 to 30 June 2000 was carried out. Recorded assessment, investigations, management, amputation rates, referral rates and length of hospital stay were reviewed.

Results:  There were 69 admission episodes in 12 months (total patients n = 50). The mean age was 64 years, with 44 male patients (64%) and 25 female patients (36%). The mean diabetes duration was 11 years (range <1−47 years). The majority of patients had type 2 dia­betes. Assessment for known risk factors for ulceration and amputation was variable with history of previous ulcer/amputation recorded for 24 (35%) admissions, results of neurological assessment recorded for 11 (16%) and assessment of pedal pulses documented for 51 (74%). Glycated haemoglobin was performed during 35 (51%) admissions. Patients were admitted under one of 11 different inpatient units and the average interdepartmental referral rate was one referral per patient per admission. The average length of stay was 17 days, with total bed days occupied 1163 days. Minor amputation was performed in 25 (36%) cases and major amputation in 8 (11%).

Conclusions:  Clinical assessment, investigation and management of this population are highly variable. This has a significant impact on the final clinical outcome, and changes to current processes are required to overcome the substantial burden of diabetic foot disease. (Intern Med J 2004; 34: 229−233)
Coxsackie B virus serology and Type 1 diabetes mellitus: a systematic review of published case‐control studies
Authors: Green J. , Casabonne D. , Newton R.
Published: May 2004

Background  Enteroviruses, in particular Coxsackie B4, have been implicated in the aetiology of Type 1 diabetes mellitus, but the epidemiological evidence has not been systematically evaluated.

Methods  Systematic review of evidence from published controlled studies of the relationship between Coxsackie B virus serology and incident or prevalent Type 1 diabetes mellitus. Studies were identified through a Medline search (1966 to 2002), supplemented by references from identified papers and hand search of relevant journals. All studies (full papers, abstracts or letters) with data adequate for calculation of unadjusted odds ratios (with 95% confidence intervals) for Type 1 diabetes mellitus in relation to Coxsackie B virus serology were included.

Results  The review included 26 case‐control studies; no cohort study met the inclusion criteria. Odds ratios for Type 1 diabetes mellitus in serology‐positive vs. serology‐negative subjects ranged from 0.2 to 22.3. For Coxsackie B (any serotype) 7/13 studies had point estimates significantly greater than 1.0 (P < 0.05). For Coxsackie B3, Coxsackie B4 and Coxsackie B5‐specific assays, 1/11, 6/17 and 1/11 studies, respectively, had point estimates significantly greater than 1.0. Summary odds ratios were not calculated because of doubts about the validity of individual study estimates, heterogeneity between studies, and the possibility of publication bias.

Conclusions  The results of these studies are inconsistent and do not provide convincing evidence for or against an association between Coxsackie B virus infection and Type 1 diabetes mellitus. Better designed studies using effective assays are needed to resolve this important issue.
Patients and nurses determine variation in adherence to guidelines at Dutch hospitals more than internists or settings
Authors: Dijkstra R. F. , Braspenning J. C. C. , Huijsmans Z. , Peters S. , Van Ballegooie E. , Ten Have P. , Casparie A. F. , Grol R. P. T. M.
Published: May 2004

Aims  To measure adherence to recently developed diabetes guidelines at Dutch hospital outpatient clinics and distinguish determinants for variations in care on hospital, internist and patient levels.

Methods  Thirteen general hospitals with 58 internists recruited 1950 diabetic patients. Data were extracted from medical files (n = 1915) and from patient questionnaires (n = 1465). Multilevel logistic regression analysis was performed to explain differences in adherence rates to the guidelines.

Results  Adherence to process measures was high, except for the examination of feet, calculation of the body mass index and patient education activities (the mean of 12 process measures was 64%). Adherence to intermediate outcome indicators was moderate. The mean percentage of patients with HbA1c < 7.0% was 23%. Adherence variation on a hospital level was very small (0.6–7.9%), on an internist level moderate (0.4–18.8%) and on a patient level high (74.4–98.8%). Adherence to all process measures and most of the intermediate outcome indicators was highest in the patients seen by a diabetes specialist nurse.

Discussion  More focus on patient involvement in diabetic care and the contribution of diabetes specialist nurses may be important factors in improving the quality of diabetes care.
Decreased stiffness at the ankle joint in patients with long‐term Type 1 diabetes
Authors: Nielsen J. F. , Andersen H. , Sinkjær T.
Published: May 2004

Aims  To evaluate contractile and reflex properties of the soleus muscle together with ankle joint stiffness in long‐term Type 1 patients.

Methods  Stretch reflex and muscle function of the soleus muscle was tested in 15 Type 1 diabetes mellitus patients and 15 controls. M‐wave amplitude and maximal twitch torque was elicited by supramaximal stimulation of the tibial nerve. The stretch reflex was elicited by a 4° rotation of the ankle.

Results  Rise time and fall time of the maximal twitch torque were increased compared with controls. The amplitude of the short latency stretch reflex was significantly reduced in patients at contraction levels of 5–30 Nm. At a contraction level of 5 Nm the median stretch reflex threshold was 10°/s in patients and 6°/s in controls (P = 0.03). Stiffness was decreased in diabetic patients, especially at lower contraction levels. There was no significant correlation between the clinical neuropathy score and stiffness. In contrast, high neuropathy score was correlated with low amplitude of the reflex amplitude (ρ = −0.51, P = 0.05).

Conclusions  We demonstrate altered contractile properties, a decrease in stretch reflex of the soleus muscle, and a reduced stiffness at the ankle joint in patients with long‐term Type 1 diabetes. These changes may cause delayed muscle contraction and impaired reflex modulation which could contribute to gait disturbances and increased number of falls in diabetic patients.