bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probing the role of oligomerization in the high thermal stability of Pyrococcus furiosus ornithine carbamoyltransferase by site‐specific mutants
Authors: Clantin Bernard , Tricot Catherine , Lonhienne Thierry , Stalon Victor , Villeret Vincent 
Published: March 2003

The Pyrococcus furiosus ornithine carbamoyltransferase (OTCase) is extremely heat stable and maintains 50% of its catalytic activity after 60 min at 100 °C. The enzyme has an unusual quaternary structure when compared to anabolic OTCases from mesophilic organisms. It is built up of four trimers arranged in a tetrahedral manner, while other anabolic enzymes are single trimers. Residues Trp21, Glu25, Met29 and Trp33 are located in the main interfaces that occur between the catalytic trimers within the dodecamer. They participate in either hydrophobic clusters or ionic interactions. In order to elucidate the role played by the oligomerization in the enzyme stability at very high temperatures, we performed mutagenesis studies of these residues. All the variants show similar catalytic activities and kinetic properties when compared to the wild‐type enzyme, allowing the interpretation of the mutations solely on heat stability and quaternary structure. The W21A variant has only a slight decrease in its stability, and is a dodecamer. The variants E25Q, M29A, W33A, W21A/W33A and E25Q/W33A show that altering more drastically the interfaces results in a proportional decrease in heat stability, correlated with a gradual dissociation of dodecamers into trimers. Finally, the E25Q/M29A/W33A variant shows a very large decrease in heat stability and is a trimer. These results suggest that extreme thermal stabilization of this OTCase is achieved in part through oligomerization.
Identification of the β‐dystroglycan binding epitope within the C‐terminal region of α‐dystroglycan
Authors: Sciandra Francesca , Schneider Martina , Giardina Bruno , Baumgartner Stefan , Petrucci Tamara C. , Brancaccio Andrea 
Published: March 2003

Dystroglycan is a receptor for extracellular matrix proteins that plays a crucial role during embryogenesis in addition to adult tissue stabilization. A precursor product of a single gene is post‐translationally cleaved to form two different subunits, α and β. The extracellular α‐dystroglycan is a membrane‐associated, highly glycosylated protein that binds to various extracellular matrix molecules, whereas the transmembrane β‐dystroglycan binds, via its cytosolic domain, to dystrophin and many other proteins. α‐ and β‐Dystroglycan interact tightly but noncovalently. We have previously shown that the N‐terminal region of β‐dystroglycan, β‐DG(654–750), binds to the C‐terminal region of murine α‐dystroglycan independently from glycosylation. Preparing a series of deleted recombinant fragments and using solid‐phase binding assays, the C‐terminal sequence of α‐dystroglycan containing the binding epitope for β‐dystroglycan has been defined more precisely. We found that a region of 36 amino acids, from position 550–585, is required for binding the extracellular region, amino acids 654–750 of β‐dystroglycan. Recently, a dystroglycan‐like gene was identified in Drosophila that showed a moderate degree of conservation with vertebrate dystroglycan (31% identity, 48% similarity). Surprisingly, the Drosophila sequence contains a region showing a higher degree of identity and conservation (45% and 66%) that coincides with the 550–585 sequence of vertebrate α‐dystroglycan. We have expressed this Drosophila dystroglycan fragment and measured its binding to the extracellular region of vertebrate (murine) β‐dystroglycan (Kd = 6 ± 1 µm). These data confirm the proper identification of the β‐dystroglycan binding epitope and stress the importance of this region during evolution. This finding might help the rational design of dystroglycan‐specific binding drugs, that could have important biomedical applications.
Protein‐bound conformation of a specific inhibitor against Candida albicans myristoyl‐CoA:protein N‐myristoyltransferase in the ternary complex with CaNmt and myristoyl‐CoA by transferred NOE measurements
Authors: Miura Takaaki , Klaus Werner , Ross Alfred , Sakata Kiyoaki , Masubuchi Miyako , Senn Hans 
Published: March 2003

Transferred nuclear Overhauser enhancement (trNOE) experiments have been performed to study the bioactive conformation(s) of Ro09‐3472/000 derivatives in the ternary complex with Candida albicans myristoyl‐CoA: protein N‐myristoyltransferase (CaNmt) and myristoylCoA (MyrCoA). A critical step in the trNOE study is to identify ‘true’ trNOEs in the spectra. Nonspecific binding of ligands to target proteins and/or spin diffusion effects can give rise to ‘false’ trNOEs, which may lead to an incorrect conclusion if used to derive bound conformations. In this study for all ligands the observed trNOEs arose from specific binding interactions with the active site of CaNmt. This was shown by displacing the ligand with the known tightly binding active‐site inhibitor 1 [Devadas, B., Zupec, M.E., Freeman, S.K., Brown, D.L., Nagarajan, S., Sikorski, J.A., McWherter, C.A., Getman, D. P. & Gordon, J.I. (1995) J. Med. Chem.38, 1837–1840] and measuring the resonance linewidths in the NMR spectrum before and after addition of the competitive inhibitor. The compounds were also tested for nonspecific protein binding with bovine serum albumin (BSA) using the same method. Of the six compounds tested, Ro09‐3700/001 (racemate) and its optically pure enantiomers, Ro09‐4764/001(S) and Ro09‐4765/001(R), showed both specific binding to CaNmt and no interaction with BSA. The NMR data of these molecules in the ternary complex with CaNmt/MyrCoA could thus be used for a detailed structural analysis. Thereby, the conformation of the bound ligand was obtained from a conformational search using the observed trNOEs as a selection filter. The NMR‐determined conformations are in good agreement with the recently solved CaNmt‐bound X‐ray structures of two similar Ro09‐3472/000 derivatives.
Ferritin from the spleen of the Antarctic teleost Trematomus bernacchii is an M‐type homopolymer
Authors: Mignogna Guiseppina , Chiaraluce Roberta , Consalvi Valerio , Cavallo Stefano , Stefanini Simonetta , Chiancone Emilia 
Published: March 2003

Ferritin from the spleen of the Antarctic teleost Trematomus bernacchii is composed of a single subunit that contains both the ferroxidase center residues, typical of mammalian H chains, and the carboxylate residues forming the micelle nucleation site, typical of mammalian L chains. Comparison of the amino‐acid sequence with those available from lower vertebrates indicates that T. bernacchii ferritin can be classified as an M‐type homopolymer. Interestingly, the T. bernacchii ferritin chain shows 85.7% identity with a cold‐inducible ferritin chain of the rainbow trout Salmo gairdneri.The structural and functional properties indicate that cold acclimation and functional adaptation to low temperatures are achieved without significant modification of the protein stability. In fact, the stability of T. bernacchii ferritin to denaturation induced by acid or temperature closely resembles that of mesophilic mammalian ferritins. Moreover iron is taken up efficiently and the activation energy of the reaction is 74.9 kJ·mol−1, a value slightly lower than that measured for the human recombinant H ferritin (80.8 kJ·mol−1).
Models of reproductive skew: A review and synthesis (Invited Article)
Authors: Johnstone Rufus A. 
Published: March 2003

AbstractAnimal societies vary markedly in reproductive skew, the extent to which breeding is monopolised by dominant individuals. In the last few years, a large number of different models have been developed to explain this variation. Here, I review existing models of reproductive skew, distinguishing between two basic types. Transactional models focus on group stability and the constraints this places on the division of reproduction. Compromise models, by contrast, ignore issues of group stability and view the division of reproduction as the outcome of a conflict in which each group member has a limited or partial ability to enforce its own optimum. I go on to show, however, that the division between transactional and compromise models is somewhat artificial, and that both approaches may be combined in a single, synthetic treatment. Different models of reproductive skew are thus better seen as special cases of a general underlying theory, rather than alternative paradigms. I conclude with a brief discussion of the possibilities and problems of empirically testing this unified theory of skew, and the prospects for future theoretical advances.
Multiple Copulations and Post‐Copulatory Guarding in a Free‐Living Population of Sika Deer (Cervus nippon)
Authors: Endo Akira , Doi Teruo 
Published: March 2003

AbstractMultiple copulations by females and post‐copulatory guarding by males, were studied in a free‐living sika deer population, on Nozaki, an island of the Goto Group, off the coast of Kyushu, Japan. In 1990, 1991, and 1993, observations were carried out mainly on open grassland in the central section of the island. It was found, that 10 of 22 females in estrus copulated more than once and five of them copulated with several males (multi‐male copulations), while the remainder copulated with a single male (repeated copulation). Almost all copulations were followed by guarding behavior. Dominant males (DMs) guarded significantly longer and more effectively than subordinate males (SMs). Guarding was interrupted in four of the SMs, when the guarding male was forcibly driven away from a female by higher ranked males (‘take‐over’) and in three cases when the female left the guarding male spontaneously (‘escape’). The only interruption of guarding of a DM was caused when a lower ranked male sneaked towards the guarded female and mated with her briefly (sneak). Interruptions of guarding initiated by females (escapes) occurred more when they were guarded by SMs than by DMs.Our results suggest that female sika deer indulge in multiple copulations to seek better genetic quality, rather than insuring fertility, enhancing genetic diversity, or avoiding harassment. The post‐copulatory guarding by DMs appears to be more effective in the prevention of additional copulations by females with other males than guarding by SMs. Moreover, SMs decrease the duration of the pre‐copulatory phase to achieve copulation before having to give way to DMs.
Viability of holm and cork oak seedlings from acorns sown in soils naturally infected with Phytophthora cinnamomi
Authors: Rodríguez‐Molina M. C. , Torres‐Vila L. M. , Blanco‐Santos A. , Núñez E. J. Palo , Torres‐Álvarez E. 
Published: March 2003

SummaryThe emergence and survival of pregerminated holm oak (Quercus ilex) and cork oak (Quercus suber) acorns from two ecologically different dehesas (Mediterranean open woodlands) were studied in two soils from these stands naturally infected with Phytophthora cinnamomi, and in the same soils previously sterilized in the autoclave. Phytophthora cinnamomi was consistently isolated from the radicles of all unemerged and all emerged but dead seedlings from the unsterilized substrates. Seedlings of holm oak were more susceptible to P. cinnamomi than those of cork oak. Mortality of holm oak seedlings was significantly different depending only on soil treatment (sterilized or unsterilized), and it was 100% in unsterilized soils, independent of acorn provenance and soil origin. Mortality of cork oak seedlings was significantly different depending on the acorn origin and soil treatment, and on the interactions acorn origin × soil origin and soil origin × soil treatment. The demonstrated high susceptibility of holm and cork oak young seedlings to P. cinnamomi could be a limiting factor in Mediterranean open woodlands (dehesas) not only in natural regeneration processes but also when reforestation by direct sowing is implemented.
Job satisfaction amongst nurses in an interim secure forensic unit in Wales
Authors: Burnard Philip , Morrison Paul , Phillips Ceri 
Published: March 2003

ABSTRACTAll grades of nursing staff in a recently established interim secure forensic unit completed the Index of Work Satisfaction (IWS; n = 40). High levels of job satisfaction were achieved on four of the IWS subscales: (i) professional status; (ii) interaction; (iii) doctor–nurse relationship; and (iv) autonomy. Moderate levels of satisfaction were found on two of the subscales, task requirements and administration, while the salary subscale was the major area of dissatisfaction across the group. The high level of overall satisfaction in this area of psychiatric nursing may be regarded as a significant achievement in the development of new clinical services in what is regarded as a stressful area of nursing. Measures of job satisfaction may be useful benchmarks for evaluating future changes and developments in the service and for monitoring and improving the clinical work environment.
Scoping practice issues in the Australian mental health nursing workforce
Authors: Clinton Michael , Hazelton Mike 
Published: March 2003

ABSTRACTThis is the third of four articles on the scoping study of the Australian mental health nursing workforce conducted on behalf of the Australian and New Zealand College of Mental Health Nurses (ANZCMHN) for the Australian Health Ministers Advisory Council (AHMAC) National Working Group on Mental Health (NWGMH). Its purpose is to focus on factors that significantly affect mental health nursing practice. The issues of advanced practice, regulation of nursing, accreditation, credentialling and demarcation with other disciplines are addressed.
THE SUCCESS OF MEN’S HEALTH NIGHTS AND HEALTH SESSIONS
Authors: Verrinder Adrian , Denner Bernard J. 
Published: March 2003

ABSTRACTMen’s health nights and men’s health sessions have proven to be remarkably successful in rural and some suburban regions of Victoria. In the rural regions, enough interest has been generated to run follow‐up health sessions on topics selected at the initial nights. Approximately 2000 men attended these events and 575 filled in questionnaires giving information such as age, occupation, health concerns and perceptions of health professionals. The results indicated that men’s health nights appeal to older men who are more likely to be professional or retired. These men saw cardiovascular disease, cancer and stress management as their main health concerns. The majority indicated that they would be interested in attending more men’s health sessions. The follow‐up sessions provide initial pathways by which men may address the issues of their own health. The data collected contributed to the development of the Men’s Awareness Network model for men’s health.
Demography and prognostic factors of ocular injuries in South India
Authors: Gothwal VK , Adolph S , Jalali S , Naduvilath TJ 
Published: March 2003

Purpose: To evaluate the extent of visual recovery after multi‐disciplinary approach of treatment in serious ocular injuries; to determine the prognostic factors associated with poor final visual outcome and suggest adequate precautionary measures. Methods: A retrospective analysis of 325 consecutive patients with direct ocular trauma who were examined and treated at a tertiary eye care centre in South India over a 3‐year period was undertaken. Results: Males (86.8%) outnumbered the females (13.2%) and children (<16 years) constituted 46.8% of the total affected population. Anterior segment was involved in 51.1%, the posterior segment in 8.9% and both anterior and posterior segments were involved in 31.4% of patients. Prompt and meticulous surgical treatment restored useful vision (better than or equal to 6/18) in 60.5% of patients. Post‐treatment, a reduction in blindness and visual impairment rates in the affected eye with respect to WHO classification was 66.7 and 54.1% respectively (P < 0.0001). Two eyes needed prompt enucleation. The factors associated with visual impairment (visual acuity less than 6/18) were poor initial visual acuity, full chamber hyphema, endophthalmitis, retinal detachment, and vitreous haemorrhage. Conclusions: Direct ocular trauma remains an important potentially preventable cause of ocular morbidity, but the advent of modern surgical techniques can often restore useful vision in such situations. Mandatory use of protective eye wear at work, public health education including awareness on the part of parents to the potential dangers of some childrens’ toys can to an extent help reduce ocular morbidity due to direct ocular trauma.
Predictors of 1-Year Outcome in Depression
Authors: Parker Gordon , Wilhelm Kay , Mitchell Philip , Gladstone Gemma 
Published: March 2003

Objective: We compared several different methods for assessing depression ‘recovery’ over a 1-year review interval, to determine the utility of the contrasting approaches. Second, we assessed baseline predictors of 1-year outcome and recovery status. Third, we examined the extent to which predictors showed consistency across the variable definitions of outcome and recovery. Methods: Twelve-month outcome was assessed in a sample of 182 subjects who at baseline assessment met DSM criteria for a major depressive episode. The contrasting methods involved a defined percentage reduction in Beck Depression Inventory self-rating scores, formalised change point definitions, no longer meeting DSM-IV major depression criteria, and clinical global improvement (CGI) ratings. Results: Sixty-one per cent reached formalised change point criteria for full remission or recovery when trajectories across the 12-month interval were examined. Other measures quantified recovery rates ranging from 43% to 70%. Those with a psychotic or melancholic depression were more likely to have achieved recovery status in some analyses. Non-recovery at 12 months was predicted most consistently by higher baseline levels of anxiety and depression; high trait anxiety and a lifetime anxiety disorder; disordered personality function; and having reported exposure to acute and enduring stressors at baseline assessment. Conclusions: While the CGI was the superior system in terms of number of significant discriminating predictors of outcome, the change point definitional approach provides much greater information across the follow-up interval, arguing for their complementary utility. As several currently identified baseline predictors of outcome (i.e. anxiety, disordered personality function) also predicted onset of depression, their relevance as both depression-inducing and depression-propagating variables is suggested.
PRIMARY MUCOSAL AND GLANS PENIS MELANOMAS: THE SYDNEY MELANOMA UNIT EXPERIENCE
Authors: Larsson K. B. M. , Shaw H. M. , Thompson J. F. , Harman R. C. , Mccarthy W. H. 
Published: March 2003

Background: Melanomas that arise on mucosal surfaces and the glans penis are rare. Methods: A retrospective study of the Sydney Melanoma Unit experience with 69 patients treated since 1956 for these types of melanomas was undertaken to determine primary lesion site, sex, age at diagnosis, symptoms, clinical stage at first presentation, histopathology, treatment and outcome. Results: Primary lesion sites were: nasal cavity (n = 9), oral cavity (n = 16), vulva/vagina (n = 25), anus/rectum (n = 13) and glans penis (n = 6). At diagnosis, 55 patients had local disease only, eight had regional lymph node metastases and six had widespread disease. Local recurrence as the first sign of relapse developed in 15 of the 55 stage I patients (three‐stage system). Prognosis for the entire group was poor, only 10% being disease free 3 years after diagnosis and overall 3‐ and 5‐year actuarial survival being 40% and 23%, respectively. The only statistically significant factor influencing survival was stage of disease at diagnosis (P = 0.002). Conclusions: Possible reasons for poor survival include: (i) non‐specific symptoms resulting in late presentation; (ii) locally advanced disease not being recognized by a clinician as a rare form of melanoma, resulting in a delay in treatment; (iii) anatomical constraints precluding surgery with generous margins and consequently resulting in a high incidence of local recurrence. Also, rich vascularity and multiple lymphatic drainage pathways may mean a predisposition to early dissemination. Prompt diagnosis and referral to a specialist unit for treatment and follow up are essential. Adequate surgery remains the cornerstone of treatment for these types of melanoma until more effective systemic therapies become available.
CLINICAL PATHWAY MANAGEMENT OF TOTAL KNEE ARTHROPLASTY: A RETROSPECTIVE COMPARATIVE STUDY
Authors: Pearson Sue , Moraw Irene , Maddern Guy J. 
Published: March 2003

Background: Clinical pathways facilitate the management of defined patient groups using interdisciplinary plans of care. The aim of the present study was to evaluate the effectiveness of a clinical pathway in improving a range of selected outcome measures in patients who have undergone total knee arthroplasty (TKA). Methods: The present study was conducted at Queen Elizabeth Hospital, Adelaide. Using a retrospective comparative study design, 119 TKA patients who were managed on a clinical pathway from July 1997 to January 1998 (group 2) were compared with a retrospective group of 58 patients who underwent the same procedure from July 1996 to January 1997 (group 1) prior to the pathway’s implementation. The following outcomes were measured: length of hospital stay; postoperative complications; readmissions and emergency service visits within 6 months of discharge; day of transfer to the convalescent unit; convalescent unit utilization and admission and discharge times. Results: There was a significant reduction in the median length of stay in group 2 patients (9 vs 7 days; P < 0.0001). In addition there was a 66% increase in the proportion of patients in group 2 who were admitted on the day of surgery (P < 0.0001) and a 19.6% increase in the number of patients discharged within 8 postoperative days (P < 0.01). There were no significant differences between the groups with respect to the occurrence of postoperative complications. Although there was a trend toward a reduction in emergency service utilization and readmissions within 6 months of discharge for patients managed on the pathway, this was not significant. Conclusions: The development and implementation of a TKA clinical pathway resulted in a significant reduction in length of stay and improved streamlining of admission, discharge and transfer processes without adversely affecting patient outcomes.
Surgical resection for pulmonary metastases from colorectal cancer
Authors: Moore K. H. , Mccaughan B. C. 
Published: March 2003

Background: Isolated pulmonary metastases from colorectal cancer are rare. The present study reports on the 15‐year experience of the Royal Prince Alfred Unit and discusses means of improving survival outcomes. Methods: This was a retrospective review, over a 15‐year period, of 41 patients who had resectable pulmonary metastases of colorectal origin. Results: Most were asymptomatic at the time of diagnosis. Seventy‐two per cent had solitary metastases. The most common procedure performed was a lobectomy. Median follow up was 21 months. Five‐year survival was 24%. There were no significant prognostic indicators except for the ability to achieve clear surgical margins. Conclusion: Morbidity and mortality have not altered significantly over time. But an improved selection process such as the use of preoperative positron emission tomography will potentially improve survival outcomes.