bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cytochrome c folds through a smooth funnel
Authors: Panda Markandeswar , Benavides‐Garcia Maria G. , Pierce Michael M. , Nall Barry T. 
Published: October 2010

AbstractA dominant feature of folding of cytochrome c is the presence of nonnative His‐heme kinetic traps, which either pre‐exist in the unfolded protein or are formed soon after initiation of folding. The kinetically trapped species can constitute the majority of folding species, and their breakdown limits the rate of folding to the native state. A temperature jump (T‐jump) relaxation technique has been used to compare the unfolding/folding kinetics of yeast iso‐2 cytochrome c and a genetically engineered double mutant that lacks His‐heme kinetic traps, H33N, H39K iso‐2. The results show that the thermodynamic properties of the transition states are very similar. A single relaxation time τobs is observed for both proteins by absorbance changes at 287 nm, a measure of solvent exclusion from aromatic residues. At temperatures near Tm, the midpoint of the thermal unfolding transitions, τobs is four to eight times faster for H33N, H39K iso‐2 (τobs ∼ 4–10 ms) than for iso‐2 (τobs ∼ 20–30 ms). T‐jumps show that there are no kinetically unresolved (τ < 1–3 mus t‐jump dead time) “burst” phases for either protein. using a two‐state model, the folding (kf) and unfolding (ku) rate constants and the thermodynamic activation parameters ΔG‡f G‡u H‡f H‡u S‡f S‡u are evaluated by fitting the data to a function describing the temperature dependence of the apparent rate constant kobs (= τ−1obs−1) = kf + ku. The results show that there is a small activation enthalpy for folding, suggesting that the barrier to folding is largely entropic. In the “new view,” a purely entropic kinetic barrier to folding is consistent with a smooth funnel folding landscape.
Direct evidence by H/D exchange and ESI‐MS for transient unproductive domain interaction in the refolding of an antibody scFv fragment
Authors: Jäger Marcus , Plückthun Andreas 
Published: October 2010

AbstractThe refolding kinetics of a single‐chain Fv (scFv) fragment, derived from a stabilized mutant of the phosphorylcholine binding antibody McPC603, was investigated by H/D exchange and ESI‐MS and compared with the folding kinetics of its constituting domains VH and VL. Both VH and VL adopt essentially native‐like exchange protection within the dead time of the manual‐mixing H/D exchange experiment (10 s) and in the case of VL, which contains two cis‐prolines in the native conformation, this fast protection is independent of proline cis/trans isomerization. At the earliest time point resolvable by manual mixing, fewer deuterons are protected in the scFv fragment than in the two isolated domains together, despite the fact that the scFv fragment is significantly more stable than VL and VH. Full H/D exchange protection in the scFv fragment is gained on a time scale of minutes. This means that the domains in the scFv fragment do not refold independently. Rather, they associate prematurely and in nonnative form, a kinetic trap. Unproductive domain association is observed both after equilibrium‐ and short‐term denaturation. For the equilibrium‐denatured scFv fragment, whose native structure formation is dependent on a cis conformation of an interface proline in VL, this cis/trans isomerization reaction proceeds about one order in magnitude more slowly than the escape from the trap to a conformation where full H/D exchange protection is already achieved. We interpret these data in terms of a general kinetic scheme involving intermediates with and without domain association.
Oxygen binding by α(Fe2+)2β(Ni2+)2 hemoglobin crystals
Authors: Bruno Stefano , Bettati Stefano , Manfredini Michele , Mozzarelli Andrea , Bolognesi Martino , Deriu Daniela , Rosano Camillo , Tsuneshige Antonio , Yonetani Takashi , Henry Eric R. 
Published: October 2010

AbstractOxygen binding by hemoglobin fixed in the T state either by crystallization or by encapsulation in silica gels is apparently noncooperative. However, cooperativity might be masked by different oxygen affinities of α and β subunits. Metal hybrid hemoglobins, where the noniron metal does not bind oxygen, provide the opportunity to determine the oxygen affinities of α and β hemes separately. Previous studies have characterized the oxygen binding by α(Ni2+)2β(Fe2+)2 crystals. Here, we have determined the three‐dimensional (3D) structure and oxygen binding of α(Fe2+)2β(Ni2+)2 crystals grown from polyethylene glycol solutions. Polarized absorption spectra were recorded at different oxygen pressures with light polarized parallel either to the b or c crystal axis by single crystal microspectrophotometry. The oxygen pressures at 50% saturation (p50s) are 95 ± 3 and 87 ± 4 Torr along the b and c crystal axes, respectively, and the corresponding Hill coefficients are 0.96 ± 0.06 and 0.90 ± 0.03. Analysis of the binding curves, taking into account the different projections of the α hemes along the optical directions, indicates that the oxygen affinity of α1 hemes is 1.3‐fold lower than α2 hemes. Inspection of the 3D structure suggests that this inequivalence may arise from packing interactions of the Hb tetramer within the monoclinic crystal lattice. A similar inequivalence was found for the β subunits of α(Ni2+)2β(Fe2+)2 crystals. The average oxygen affinity of the α subunits (p50 = 91 Torr) is about 1.2‐fold higher than the β subunits (p50 =110 Torr). In the absence of cooperativity, this heterogeneity yields an oxygen binding curve of Hb A with a Hill coefficient of 0.999. Since the binding curves of Hb A crystals exhibit a Hill coefficient very close to unity, these findings indicate that oxygen binding by T‐state hemoglobin is noncooperative, in keeping with the Monod, Wyman, and Changeux model.
NMR solution structure of the θ subunit of DNA polymerase III from Escherichia coli
Authors: Keniry Max A. , Berthon Hilary A. , Yang Ji Yeon , Miles Caroline S. , Dixon Nicholas E. 
Published: October 2010

AbstractThe catalytic core of Escherichia coli DNA polymerase III contains three tightly associated subunits (α, €, and θ). The θ subunit is the smallest, but the least understood of the three. As a first step in a program aimed at understanding its function, the structure of the θ subunit has been determined by triple‐resonance multidimensional NMR spectroscopy. Although only a small protein, θ was difficult to assign fully because approximately one‐third of the protein is unstructured, and some sections of the remaining structured parts undergo intermediate intramolecular exchange. The secondary structure was deduced from the characteristic nuclear Overhauser effect patterns, the 3JHNα coupling constants and the consensus chemical shift index. The C‐terminal third of the protein, which has many charged and hydrophilic amino acid residues, has no well‐defined secondary structure and exists in a highly dynamic state. The N‐terminal two‐thirds has three helical segments (Gln10‐Asp19, Glu38‐Glu43, and His47‐Glu54), one short extended segment (Pro34‐Ala37), and a long loop (Ala20‐Glu29), of which part may undergo intermediate conformational exchange. Solution of the three‐dimensional structure by NMR techniques revealed that the helices fold in such a way that the surface of θ is bipolar, with one face of the protein containing most of the acidic residues and the other face containing most of the long chain basic residues. Preliminary chemical shift mapping experiments with a domain of the € subunit have identified a loop region (Ala20‐Glu29) in θ as the site of association with €.
The sarcosine effect on protein stability: A case of nonadditivity?
Authors: Ibarra‐Molero Beatriz , Del Pino Isabel M. Plaza , Souhail Badredine , Hammou Hassan O. , Sanchez‐Ruiz Jose M. 
Published: October 2010

AbstractWe have used differential scanning calorimetry to determine the effect of low concentrations (C = 0–2 M) of the osmolyte sarcosine on the Gibbs energy changes (δG) for the unfolding of hen‐egg‐white lysozyme, ribonuclease A, and ubiq‐uitin, under the same buffer and pH conditions. We have also computed this effect on the basis of the additivity assumption and using published values of the transfer Gibbs energies for the amino acid side chains and the peptide backbone unit. The values thus predicted for the slope ∂ΔLG/∂C agree with the experimental ones, but only if the unfolded state is assumed to be compact (that is, if the accessibility to solvent of the unfolded state is modeled using segments excised from native structures). The additivity‐based calculations predict similar ∂ΔLG/∂C values for the three proteins studied. We point out that, to the extent that this approximate constancy of ∂ΔLG/∂C holds, osmolyte‐induced increases in denaturation temperature will be larger for proteins with low unfolding enthalpy (small proteins that bury a large proportion of apolar surface). The experimental results reported here are consistent with this hypothesis.
Infection of Arabidopsis thaliana by Phytophthora parasitica and identification of variation in host specificity
Authors: WANG YAN , MENG YULING , ZHANG MENG , TONG XINMENG , WANG QINHU , SUN YINYIN , QUAN JUNLI , GOVERS FRANCINE , SHAN WEIXING 
Published: October 2010

SUMMARYOomycete pathogens cause severe damage to a wide range of agriculturally important crops and natural ecosystems. They represent a unique group of plant pathogens that are evolutionarily distant from true fungi. In this study, we established a new plant–oomycete pathosystem in which the broad host range pathogen Phytophthora parasitica was demonstrated to be capable of interacting compatibly with the model plant Arabidopsis thaliana. Water‐soaked lesions developed on leaves within 3 days and numerous sporangia formed within 5 days post‐inoculation of P. parasitica zoospores. Cytological characterization showed that P. parasitica developed appressoria‐like swellings and penetrated epidermal cells directly and preferably at the junction between anticlinal host cell walls. Multiple haustoria‐like structures formed in both epidermal cells and mesophyll cells 1 day post‐inoculation of zoospores. Pathogenicity assays of 25 A. thaliana ecotypes with six P. parasitica strains indicated the presence of a natural variation in host specificity between A. thaliana and P. parasitica. Most ecotypes were highly susceptible to P. parasitica strains Pp014, Pp016 and Pp025, but resistant to strains Pp008 and Pp009, with the frequent appearance of cell wall deposition and active defence response‐based cell necrosis. Gene expression and comparative transcriptomic analysis further confirmed the compatible interaction by the identification of up‐regulated genes in A. thaliana which were characteristic of biotic stress. The established A. thaliana–P. parasitica pathosystem expands the model systems investigating oomycete–plant interactions, and will facilitate a full understanding of Phytophthora biology and pathology.
The health of hospitals and lessons from history: public health and sanitary reform in the Dublin hospitals, 1858–1898
Authors: Fealy Gerard M , McNamara Martin S , Geraghty Ruth 
Published: October 2010

Aims and objectives.  The aim was to examine, critically, 19th century hospital sanitary reform with reference to theories about infection and contagion.Background.  In the nineteenth century, measures to control epidemic diseases focused on providing clean water, removing waste and isolating infected cases. These measures were informed by the ideas of sanitary reformers like Chadwick and Nightingale, and hospitals were an important element of sanitary reform.Design.  Informed by the paradigmatic tradition of social history, the study design was a historical analysis of public health policy.Method.  Using the methods of historical research, documentary primary sources, including official reports and selected hospital archives and related secondary sources, were consulted.Results.  Emerging theories about infection were informing official bodies like the Board of Superintendence of Dublin Hospitals in their efforts to improve hospital sanitation. The Board secured important reforms in hospital sanitation, including the provision of technically efficient sanitary infrastructure.Conclusions.  Public health measures to control epidemic infections are only as effective as the state of knowledge of infection and contagion and the infrastructure to support sanitary measures.Relevance to clinical practice.  Today, public mistrust about the safety of hospitals is reminiscent of that of 150 years ago, although the reasons are different and relate to a fear of contracting antimicrobial‐resistant infections. A powerful historical lesson from this study is that resistance to new ideas can delay progress and improved sanitary standards can allay public mistrust. In reforming hospital sanitation, policies and regulations were established – including an inspection body to monitor and enforce standards – the benefits of which provide lessons that resonate today. Such practices, especially effective independent inspection, could be adapted for present‐day contexts and re‐instigated where they do not exist. History has much to offer contemporary policy development and practice reform and is a relevant method for health professionals.
Injuries, falls and accidents among adults with intellectual disabilities. Prospective cohort study
Authors: Finlayson J. , Morrison J. , Jackson A. , Mantry D. , Cooper S.‐A. 
Published: October 2010

AbstractBackground  Injuries are among the leading causes of death and disability in the world and a major public health concern. Falls are a common cause. Young persons with intellectual disabilities (ID) have a higher rate and different pattern of injuries than the general population, but little is known regarding adults.Methods  The aim of this study was to determine the incidence and types of injuries experienced by a community‐based cohort of adults with ID (n = 511) in a 12‐month period. Face‐to‐face interviews were conducted with participants 2 years after they had first been recruited into a longitudinal study.Results  Incidence of at least one injury in a 12‐month period was 20.5% (105), of which 12.1% (62) was because of falls. Incident injury was predicted by having epilepsy and not having autism. Incident fall injury was predicted by urinary incontinence, while Down syndrome reduced risk.Conclusions  Adults with ID do experience a higher rate of injuries and falls when compared with the general population. The results of this study highlight this, and hence the need to work towards the development of interventions for injury and falls prevention in this population.
The effect of configuration on VSWM performance of Down syndrome individuals
Authors: Carretti B. , Lanfranchi S. 
Published: October 2010

AbstractBackground  Recent studies have demonstrated that individuals with Down syndrome (DS) are poorer than controls in spatial‐simultaneous tasks, but not in spatial‐sequential tasks. To explain this finding, it has been suggested that the simultaneous visuo‐spatial working memory deficit of individuals with DS could be due to the request for processing more than one item at a time. The present study examines the possibility of reducing the difficulties encountered by DS individuals on spatial‐simultaneous tasks by proposing a task that uses structured material.Method  Two tasks were administered to 20 children and adolescents with DS, and 20 controls matched for verbal mental age. The tasks involved memorising and recalling filled‐cell positions in a series of matrices in which an increasing number of cells (1–7) were filled. In the structured condition the filled cells were displayed to form a pattern, whereas in the random condition they were randomly arranged.Results and Conclusions  Results showed that individuals with DS are able to take advantage of structured material for raising their performance, but to a less extent than typically developing children.
Fulminant Clostridium difficile toxic megacolon in a pediatric heart transplant recipient
Authors: Patel Angira , Gossett Jeffrey J. , Benton Tara , Rowell Erin , Russell Hyde , Cham Elaine , Pahl Elfriede 
Published: October 2010

Patel A, Gossett JJ, Benton T, Rowell E, Russell H, Cham E, Pahl E. Fulminant Clostridium difficile toxic megacolon in a pediatric heart transplant recipient.  Pediatr Transplantation 2010: : E30–E34. © 2010 John Wiley & Sons A/S.Abstract:  CD can be a cause of diarrhea in pediatric heart transplant recipients. Fulminant colitis can develop in immunocompromised patients with CD and progress to toxic megacolon. We report a case of a 10‐yr‐old girl who developed CD diarrhea and subsequently fulminant colitis with clinical signs and symptoms of abdominal compartment syndrome. She was taken to the operating room emergently and found to have toxic megacolon. She underwent a sub‐total abdominal colectomy and end‐ileostomy, and made a rapid recovery. Rapid recognition of the severity of the disease in the post‐operative transplant patient is imperative as abdominal compartment syndrome may develop requiring surgical management. In pediatric heart transplant patients with diarrhea, we recommend a heightened clinical awareness with aggressive treatment given the risk of progression to fulminant CD and toxic megacolon.
Immunohistochemical Localization of Oestrogen Receptor Alpha in the Various Cell Categories of Chick Embryo Ovary
Authors: Civinini A. , Chimenti C. , Gallo V. P. 
Published: October 2010

With 2 figuresSummaryThe immunohistochemical (IHC) localization of oestrogen receptor alpha (ERα) was studied in the developing left ovary of 14.5‐day‐old chick embryos. The study was focused in particular on distinguishing in cortex and medulla the different cell categories that proved positive to the reaction, in order to gain further understanding of gonadal cell interactions during ovarian development. Immunostained cells were observed in both the cortex and medulla, but the reactivity for ERα was discontinuous, probably due to variable cell requirements. In the cortex, positivity was observed in cells of the ovarian surface epithelium, in germ cells and in prefollicular cells. In the medulla, positivity was found in the following cell categories: interstitial cells, poorly differentiated somatic cord cells, including those delimiting lacunae, germ cells and their accompanying cells of epithelial origin. Furthermore, the IHC results showed that the intracellular localization of the antigen was cytoplasmic, nuclear, or both. The significance of ERα presence and intracellular localization was discussed in relation and as supplementary to previous research by various Authors. In particular, as regards the unusual cytoplasmic immunoreactivity, a gradual shift of ERα localization from cytoplasmic to nuclear during the embryonic period is suggested.
Uterine Fibrosarcoma in a Warmblood Mare
Authors: Govaere J , Maes S , Saey V , Blancke W , Hoogewijs M , Deschauwer C , Smits K , Roels K , Vercauteren G , de Kruif A 
Published: October 2010

ContentsThis paper describes a case of uterine fibrosarcoma in an 18‐year‐old Warmblood mare. The mare had exhibited bloody fluid accumulation inside the uterus and vaginal haemorrhagic discharge since the previous foaling. The mare was euthanized, and on pathological examination, in addition to the uterine neoplasia, multiple metastases were found in the lungs, liver and spleen. The histological and immunohistochemical examination determined that the tumour was a fibrosarcoma. To our knowledge, this is the first paper to describe a uterine fibrosarcoma in a mare.
Multimedia patient education to assist the informed consent process for knee arthroscopy
Authors: Cornoiu Andrei , Beischer Andrew D. , Donnan Leo , Graves Stephen , de Steiger Richard 
Published: October 2010

AbstractBackground:  In contemporary clinical practice, the ability for orthopaedic surgeons to obtain true ‘informed consent’ is becoming increasingly difficult. This problem has been driven by factors including increased expectations of surgical outcome by patients and increasing complexity of surgical procedures. Surgical pamphlets and computer presentations have been advocated as ways of improving patient education, but evidence of their efficacy is limited. The aim of this study was to compare the efficacy of a computer‐based multimedia (MM) presentation against standardized verbal consent and information pamphlets for patients considering knee arthroscopy surgery.Methods:  A randomized, controlled prospective trial was conducted, comparing the efficacy of three methods of providing preoperative informed consent information to patients. Sixty‐one patients were randomly allocated into MM, verbal consent or pamphlet groups 3–6 weeks prior to knee arthroscopy surgery. Information recall after the initial consent process was assessed by questionnaire. Retention of this information was again assessed by questionnaire at the time of surgery and 6 weeks after surgery.Results:  The MM group demonstrated a significantly greater proportion of correct responses, 98%, in the questionnaire at the time of consent, in comparison with 88% for verbal and 76% for pamphlet groups, with no difference in anxiety levels. Information was also better retained by the MM group up to 6 weeks after surgery. Patient satisfaction with information delivery was higher in the MM group.Conclusion:  MM is an effective tool for aiding in the provision and retention of information during the informed consent process.
The acute surgical unit: improving emergency care
Authors: Von Conrady Dora , Hamza Saud , Weber Dieter , Kalani Koorush , Epari Krishna , Wallace Marina , Fletcher David 
Published: October 2010

AbstractBackground:  Acute care surgical teams are a new concept in the provision of emergency general surgery. Juggling emergency patients around the surgeons' and staffs' elective commitments resulted in semi‐emergency procedures routinely being delayed. In an era of increasing financial pressure and the recent introduction of ‘safe work hours’ practices, the need for a new system which optimized available resources became apparent.Methods:  At Fremantle Hospital we developed a new system in a concerted effort to minimize the waiting time for general surgical referrals in the Emergency Department, as well as to move semi‐urgent operating from the afterhours to the daytime. To analyse the impact of the ASU, data were collected during February, March, and April 2009 and compared with data from the same period in 2008.Results:  Although most referrals were received afterhours, over 85% of operations were performed during working hours compared with 72% in the 2008 period. The time from referral to review decreased from an average of 3.2 h in 2008 to 2.1 h. The mean duration of stay in 2009 was 3 days, which was a reduction from 4.2 days in 2008. An increase in weekend discharge rates was seen after the introduction of the ASU.Conclusion:  Despite an increased workload, more referrals were seen and more operations performed during working hours and the time from referral to review was reduced. Higher discharge rates and reduced length of stays increased the availability of beds. We have demonstrated a successful new model which continues to evolve.