bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical-Site Infection Following Spinal Fusion: A Case-Control Study in a Children's Hospital
Authors: Labbé Annie-Claude , Demers Anne-Marie , Rodrigues Ramona , Arlet Vincent , Tanguay Kim , Moore Dorothy L.
Published: March 2006

Objectives:

To determine the rates of surgical-site infections (SSIs) after spinal surgery and to identify the risk factors associated with infection.

Design:

SSIs had been identified by active prospective surveillance. A case-control study to identify risk factors was performed retrospectively.

Setting:

University-associated, tertiary-care pediatric hospital.

Patients:

All patients who underwent spinal surgery between 1994 and 1998. Cases were all patients who developed an SSI after spinal surgery. Controls were patients who did not develop an SSI, matched with the cases for the presence or absence of myelodysplasia and for the surgery date closest to that of the case.

Results:

There were 10 infections following 125 posterior spinal fusions, 4 infections after 50 combined anterior-posterior fusions, and none after 95 other operations. The infection rate was higher in patients with myelodysplasia (32 per 100 operations) than in other patients (3.4 per 100 operations; relative risk = 9.45;P< .001). Gram-negative organisms were more common in early infections andStaphylococcus aureusin later infections. Most infections occurred in fusion involving sacral vertebrae (odds ratio [OR] = 12.0;P= .019). Antibiotic prophylaxis was more frequently suboptimal in cases than in controls (OR = 5.5;P= .034). Five patients required removal of instrumentation and 4 others required surgical debridement.

Conclusions:

Patients with myelodysplasia are at a higher risk for SSIs after spinal fusion. Optimal antibiotic prophylaxis may reduce the risk of infection, especially in high-risk patients such as those with myelodysplasia or those undergoing fusion involving the sacral area.
Low Frequency of Fires From Alcohol-Based Hand Rub Dispensers in Healthcare Facilities
Authors: Boyce John M. , Pearson Michele L.
Published: March 2006

We administered a web-based questionnaire to SHEA, APIC, and EIN members to assess the frequency of fires associated with alcohol-based hand rub (ABHR) dispensers in healthcare settings. None of the 798 responding facilities using ABHRs reported a dispenser-related fire; 766 facilities had accrued an estimated 1,430 hospital-years of ABHR use.
Rethinking Sterilization Practices: Evidence for Event-Related Outdating
Authors: Webster Joan , Lloyd Wendy , Ho Ping , Burridge Christine , George Narelle
Published: March 2006

A prospective study was conducted during a 2-year period to evaluate the effectiveness of event-related outdating. Hospital-prepared sterilized items (n = 152) were shelved in wards and every 3 months, several articles were retrieved and microbiologically tested. During the 2-year period, all of the items tested were sterile.
Use of Pulsed-Field Gel Electrophoresis in Infection Control Issues ConcerningBurkholderia cepacia
Authors: Jenney Adam , Liolios Lisa , Spelman Denis , Russo Philip , Wilson John , Wesselingh Steven , Kotsimbos Tom
Published: March 2006

There was concern that nosocomial person-to-person transmission ofBurkholderia cepaciahad occurred when two patients with cystic fibrosis shared a bathroom. Pulsed-field gel electrophoresis demonstrated that the two isolates were unrelated. Subsequent testing of 34 stored isolates ofB. cepaciademonstrated that no particular clone predominated in our hospital.
Prediction Model to Identify Patients WithStaphylococcus aureusBacteremia at Risk for Methicillin Resistance
Authors: Lodise Thomas P. , McKinnon Peggy S. , Rybak Michael
Published: March 2006

Objectives:

To identify institution-specific risk factors for MRSA bacteremia and develop an objective mechanism to estimate the probability of methicillin resistance in a given patient withStaphylococcus aureusbacteremia (SAB).

Design:

A cohort study was performed to identify institution-specific risk factors for MRSA. Logistic regression was used to model the likelihood of MRSA A stepwise approach was employed to derive a parsimonious model. The MRSA prediction tool was developed from the final model.

Setting:

A 279-bed, level 1 trauma center.

Patients:

Between January 1, 1999, and June 30, 2001, 494 patients with clinically significant episodes of SAB were identified.

Results:

The MRSA rate was 45.5%. Of 18 characteristics included in the logistic regression, the only independent features for MRSA were prior antibiotic exposure (OR, 9.2; CI95, 4.8 to 17.9), hospital onset (OR, 3.0; CI95, 1.9 to 4.9), history of hospitalization (OR, 2.5; CI95, 1.5 to 3.8), and presence of decubitus ulcers (OR, 2.5; CI95, 1.2 to 4.9). The prediction tool was derived from the final model, which was shown to accurately reflect the actual MRSA distribution in the cohort.

Conclusion:

Through multivariate modeling techniques, we were able to identify the most important determinants of MRSA at our institution and develop a tool to predict the probability of methicillin resistance in a patient with SAB. This knowledge can be used to guide empiric antibiotic selection. In the era of antibiotic resistance, such tools are essential to prevent indiscriminate antibiotic use and preserve the longevity of current antimicrobials.
Duration of Empiric Antibiotics for Suspected Early-Onset Sepsis in Extremely Low Birth Weight Infants
Authors: Cordero Leandro , Ayers Leona W.
Published: March 2006

Objectives:

To study multicenter antibiotic practices for suspected early-onset sepsis (EOS) with negative blood cultures (NegBCs) and to identify opportunities for reduction of antimicrobial exposure.

Design:

Retrospective study.

Setting:

Thirty academic hospitals (University HealthSystem Consortium) located in 24 states.

Methods:

Data were from a survey of 790 extremely low birth weight (ELBW) infants. Total antibiotic exposures (antibiotic-days per patient) were calculated.

Results:

On admission to the NICU, 94% of 790 ELBW infants had BCs performed and empiric antibiotics initiated. When PosBC and NegBC infants were compared, 47 patients with PosBCs were similar to 695 with NegBCs in birth weight, gestational age (GA), and mortality. Patients with suspected EOS but NegBCs given ampicillin/aminoglycosides were grouped by length of administration and GA. For GA of 26 weeks or younger, 170 infants given a short (≤ 3 days) and 157 given a long (≥ 7 days) course were similar regarding birth weight, mortality, antepartum history, and CRIB scores, but were different (P < .01) in number receiving a third antimicrobial (3% and 17%) and antibiotic-days (23 and 38). For GA of 27 weeks or older, 113 infants given a short and 77 given a long course differed (P < .01) in number receiving a third antimicrobial (2% and 23%) and antibiotic-days (19 and 30).

Conclusions:

Most suspected EOS infants with NegBCs are given antibiotics, but no antepartum historical risk factors or neonatal clinical signs explained prolonged administration. Discontinuing empiric antibiotics when BCs are negative in asymptomatic ELBW infants can reduce antimicrobial exposure without compromising clinical outcome.
Outcomes Associated With Vancomycin-Resistant Enterococci: A Meta-Analysis
Authors: Salgado Cassandra D. , Farr Barry M.
Published: March 2006

Background:

Because patients with vancomycin-resistantEnterococcusbacteremia (VREB) usually have a higher severity of illness, it has been unclear whether VREB is worse than vancomycin-susceptibleEnterococcusbacteremia (VSEB).

Methods:

Data on morbidity and case fatality rates and costs were pooled from studies comparing VREB and VSEB, identified by Medline (January 1986 to April 2002) and meeting abstracts. Heterogeneity across studies was assessed with contingency table chi-square. Multivariate analyses (MVAs) controlling for other predictors were evaluated.

Results:

Thirteen studies compared case-fatality rates of VREB and VSEB. VREB case fatality was significantly higher (48.9% vs 19%; RR, 2.57; CI95, 2.27 to 2.91; attributable mortality = 30%). Five studies compared VREB with VSEB when bacteremia was the direct cause of death; VREB case fatality was significantly higher (39.1% vs 21.8%; RR, 1.79; CI95, 1.28 to 2.5; attributable mortality = 17%). Four MVAs found significant increases in case-fatality rates (OR 2.10 to 4.0), 3 showed trends toward increase (OR, 1.74 to 3.34 with wide confidence intervals), and 3 with low statistical power found no difference. VREB recurred in 16.9% versus 3.7% with VSEB (P< .0001). Three studies reported significant increases in LOS, costs, or both with VREB.

Conclusion:

Most studies have had inadequate sample size, inadequate adjustment for other predictors of adverse outcomes, or both, but available data suggest that VREB is associated with higher recurrence, mortality, and excess costs than VSEB including multiple studies adjusting for severity of illness.
A triangulation of 𝐺𝐿(𝑛,𝐹)
Authors: Tupan Alexandru
Published: March 2006

Let

F
F

be a non-Archimedian field. We prove that each open and compact subset of

G
L

n

(
F
)

\mathrm {GL}_n(F)

can be decomposed into finitely many open, compact, and self-conjugate subsets. As a corollary, we obtain a short, elementary proof of a well-known theorem of I.M. Gelfand and D.A. Kazhdan.
Equilibria and Restoring Forces in Models of Vote Dynamics
Authors: McDonald Michael D. , Best Robin
Published: March 2006

Theories of voting tell us that party vote dynamics have two core components, long-run equilibria and more or less rapid returns to equilibria after short-run deviations. Statistical models used to represent these theories, however, tend to emphasize one component or the other. The unbalanced emphasis leaves the theoretical ideas underspecified and produces biased estimates of both long- and short-run components of vote dynamics. We specify the two components in the familiar form of an error correction model and demonstrate its advantages in terms of its theoretical consistency, simplicity, and precise prediction of whether something is wrong. We illustrate its usefulness by applying it to two sets of analyses reported in the literature and showing that it usually changes the conclusions reported in regard to both the equilibrium levels of party competition and the strength of restoring forces.
Word frequency analysis reveals enrichment of dinucleotide repeats on the human X chromosome and [GATA]nin the X escape region
Authors: McNeil John A. , Smith Kelly P. , Hall Lisa L. , Lawrence Jeanne B.
Published: March 2006

Most of the human genome encodes neither protein nor known functional RNA, yet available approaches to seek meaningful information in the “noncoding” sequence are limited. The unique biology of the X chromosome, one of which is silenced in mammalian females, can yield clues into sequence motifs involved in chromosome packaging and function. Although autosomal chromatin has some capacity for inactivation, evidence indicates that sequences enriched on the X chromosome render it fully competent for silencing, except in specific regions that escape inactivation. Here we have used a linguistic approach by analyzing the frequency and distribution of nine base-pair genomic “words” throughout the human genome. Results identify previously unknown sequence differences on the human X chromosome. Notably, the dinucleotide repeats [AT]n, [AC]n, and [AG]nare significantly enriched across the X chromosome compared with autosomes. Moreover, a striking enrichment (>10-fold) of [GATA]nis revealed throughout the 10-Mb segment at Xp22 that escapes inactivation, and is confirmed by fluorescence in situ hybridization. A similar enrichment is found in other eutherian genomes. Our findings clearly demonstrate sequence differences relevant to the novel biology and evolution of the X chromosome. Furthermore, they implicate simple sequence repeats, linked to gene regulation and unusual DNA structures, in the regulation and formation of facultative heterochromatin. Results suggest a new paradigm whereby a regional escape from X inactivation is due to the presence of elements that prevent heterochromatinization, rather than the lack of other elements that promote it.
Unravelling the multi‐stage burial history of the Swiss Molasse Basin: integration of apatite fission track, vitrinite reflectance and biomarker isomerisation analysis
Authors: Mazurek Martin , Hurford Anthony J. , Leu Werner
Published: March 2006

A complex basin evolution was studied using various methods, including thermal constraints based on apatite fission‐track (AFT) analysis, vitrinite reflectance (VR) and biomarker isomerisation, in addition to a detailed analysis of the regional stratigraphic record and of the lithological properties. The study indicates that (1) given the substantial amount of data, the distinction and characterisation of successive stages of heating and burial in the same area are feasible, and (2) the three thermal indicators (AFT, VR and biomarkers) yield internally consistent thermal histories, which supports the validity of the underlying kinetic algorithms and their applicability to natural basins. All data pertaining to burial and thermal evolution were integrated in a basin model, which provides constraints on the thickness of eroded sections and on heat flow over geologic time.

Three stages of basin evolution occurred in northern Switzerland. The Permo‐Carboniferous strike–slip basin was characterised by high geothermal gradients (80–100°C km−1) and maximum temperature up to 160°C. After the erosion of a few hundreds of metres in the Permian, the post‐orogenic, epicontinental Mesozoic basin developed in Central Europe, with subsidence triggered by several stages of rifting. Geothermal gradients in northern Switzerland during Cretaceous burial were relatively high (35–40°C km−1), and maximum temperature typically reached 75°C (top middle Jurassic) to 100°C (base Mesozoic). At least in the early Cretaceous, a stage of increased heat flow is needed to explain the observed maturity level. After erosion of 600–700 m of Cretaceous and late Jurassic strata during the Paleocene, the wedge‐shaped Molasse Foreland Basin developed. Geothermal gradients were low at this time (≤20°C km−1). Maximum temperature of Miocene burial exceeded that of Cretaceous burial in proximal parts (<35 km from the Alpine front), but was lower in more distal parts (>45 km). Thus, maximum temperature as well as maximum burial depth ever reached in Mesozoic strata occurred at different times in different regions. Since the Miocene, 750–1050 m were eroded, a process that still continues in the proximal parts of the basin. Current average geothermal gradients in the uppermost 2500 m are elevated (32–47°C km−1). They are due to a Quaternary increase of heat flow, most probably triggered by limited advective heat transport along Paleozoic faults in the crystalline basement.
Association between non‐Hodgkin lymphoma and haplotypes in the TNF region
Authors: Spink Charlotte F. , Keen Leigh J. , Mensah Fiona K. , Law Graham R. , Bidwell Jeff L. , Morgan Gareth J.
Published: March 2006

The cytokines tumour necrosis factor‐α (TNFα) and lymphotoxin‐α (LTα) are known to play key roles in B‐cell growth, differentiation and maturation. Genetic polymorphism within regulatory regions of these cytokine genes can alter expression levels and may be important in development of lymphoid malignancy. This study investigates a number of single nucleotide polymorphisms (SNPs) and microsatellite variants present within these genes in a large cohort of non‐Hodgkin lymphoma (NHL) cases including 211 cases of follicular lymphoma (FL) and 281 cases of diffuse large B‐cell lymphoma (DLBCL), and 478 unaffected controls. The study investigated whether particular alleles at these loci, or their combination across the TNF region in the form of haplotypes, may act as markers for predisposition and development of NHL. The study provided evidence for an influence of the TNF region in the susceptibility to NHL, whereby the loci −863, −857, TNFe and TNFd categorised five haplotype groups over which risk of both FL and DLBCL varied significantly. Prediction of disease risk was improved by the addition of loci to the haplotype, demonstrating the importance of considering the haplotype‐specific context of the loci in genetic risk assessment.
William Hewson (1739–74): the father of haematology
Authors: Doyle Derek
Published: March 2006

William Hewson has been called the father of haematology. Initially working alongside the Hunter brothers in London in the mid‐18th century, he advanced our knowledge of red and white cells (but mistakenly thought some red cells started as white cells and could not recognise different varieties of white corpuscles), showed that it was fibrinogen and not the cells that led to coagulation, greatly advanced our knowledge of the lymphatic system in humans, fishes and amphibians, explored the functions of the thymus and spleen and, investigated pneumothorax and surgical emphysema. His life, cut short at 35 years, was often intertwined with those of the Hunters, Alexander Monro secundus and Benjamin Franklin. This paper reviews his work, his relationships and his impact on a nascent science.
Impact of two independent bone marrow samples on minimal residual disease monitoring in childhood acute lymphoblastic leukaemia
Authors: van der Velden Vincent H. J. , Hoogeveen Patricia G. , Pieters Rob , van Dongen Jacques J. M.
Published: March 2006

Minimal residual disease (MRD) diagnostics are used for risk group stratification in several acute lymphoblastic leukaemia (ALL) treatment protocols. It is, however, unclear whether MRD is homogeneously distributed within the bone marrow (BM) and whether this affects MRD diagnostics. We, therefore, analysed MRD levels in 141 paired BM samples (two independent punctures at different locations) from 26 ALL patients by real‐time quantitative polymerase chain reaction (PCR) analysis of immunoglobulin and T‐cell receptor gene rearrangements. MRD levels were comparable in 112 paired samples (79%), whereas two samples (both taken at day 15) had MRD levels that differed more than threefold. In the remaining 27 paired samples, MRD could be quantified or detected in one sample only. In four patients, MRD‐based risk group classification was dependent on the site of BM puncture. Repetition of MRD analyses using 10‐fold replicates instead of triplicates resolved most differences. In conclusion, MRD levels in paired BM samples were highly comparable, indicating that it is sufficient to analyse MRD in a single sample only. Nevertheless, MRD‐based risk group classification can differ between paired BM samples, mainly because of variation below the quantitative range of the PCR assay rather than to a different distribution of leukaemic cells within the BM.
Immunostimulation of larvae and juveniles of cod, Gadus morhua L.
Authors: Magnadottir B , Gudmundsdottir B K , Lange S , Steinarsson A , Oddgeirsson M , Bowden T , Bricknell I , Dalmo R A , Gudmundsdottir S
Published: March 2006

Cod larval culture is currently hampered by high mortalities in the first 2–3 weeks after hatching, often due to infectious diseases. The immune system of cod is not fully competent until 2–3 months after hatching. Conventional vaccination is, therefore, not of value before this time, and the larvae are wholly reliant on non‐specific parameters for their defence against infection. A range of substances, generally derived from bacterial, fungal or plant origin, can activate these non‐specific parameters. During three hatching seasons, 2001–2003, at the Marine Institute's Experimental Station, Stadur, Grindavik, Iceland, the effects of several immunostimulants on survival and disease resistance of cod larvae and juveniles were examined. Both bathing treatments and administration in the feed were used. One of these substances, lipopolysaccharide (LPS), isolated from the bacterium Aeromonas salmonicida (ssp. salmonicida or achromogenes), appeared in some instances to improve survival and have a beneficial effect on disease resistance. Other substances tested had limited effects. The results emphasize the need for further work in this field.
Diet, blood lipid profile and physical activity patterns in primary school children from a semi‐rural area of Greece
Authors: Magkos F. , Piperkou I. , Manios Y. , Papoutsakis C. , Yiannakouris N. , Cimponerio A. , Aloumanis K. , Skenderi K. , Papathoma A. , Arvaniti F. , Sialvera T. E. , Christou D. , Zampelas A.
Published: March 2006

Background  Risk factors for heart disease are becoming increasingly prevalent among young populations. The aim of this study was to assess the cardiovascular risk profile of young adolescents living in a semi‐rural area of mainland Greece, Volos.

Materials and methods  A total of 198 children (106 females and 92 males) aged 11.6 ± 0.4 years were randomly recruited.

Results  Mean body mass index was 20.4 ± 3.5 kg m−2, while 30.3% of children were overweight and 6.7% were obese; no differences were observed between boys and girls. Mean plasma cholesterol (4.93 ± 0.75 mmol L−1), low‐density lipoprotein‐cholesterol (3.29 ± 0.64 mmol L−1) and triglyceride (0.97 ± 0.31 mmol L−1) concentrations were above age‐specific recommended values. On the other hand, mean high‐density lipoprotein‐cholesterol was acceptable for 92.3% of the children. Self‐reported daily energy intake (8.37 ± 3.06 MJ) was adequate for age, but intake of fat was high (42.0 ± 9.2% of energy) and that of carbohydrate was relatively low (44.5 ± 10.0% of energy). Saturated fat consumption was elevated (15.6 ± 4.3% of energy), while polyunsaturated fat intake fell short (4.8 ± 1.6% of energy). The study participants spent 9.60 ± 6.44 h week−1 on moderate to vigorous physical activities, while they devoted 16.60 ± 8.81 h week−1 to sedentary activities. Boys spent significantly more time than girls on both physical (P < 0.001) and sedentary (P = 0.001) activities. No major gender differences were observed in anthropometric, dietary and plasma lipid parameters.

Conclusion  The findings from the present study support the worrisome trends that have been documented in Greek youngsters elsewhere, and predict an unfavourable cardiovascular risk profile for the Greek population in the foreseeable future.
A personalized snack‐based intervention for hip fracture patients: development, feasibility and acceptability
Authors: Price Rosemary J. G. , McMurdo Marion E. T. , Anderson Annie S.
Published: March 2006

Introduction  Undernutrition is common in older people admitted to hospital with hip fracture. Oral supplementation with sip feeds may be provided but compliance is a major problem.

Objective  To develop a personalized snack‐based intervention for practical implementation in hip fracture patients and to assess feasibility, adherence, acceptability and cost.

Participants and methods  Twenty‐three older hip fracture patients with a mean age (SD) 84.1 (6.3) were provided with three between‐meal snacks daily for 4 weeks following surgery. Dietary counselling, assessment of acceptability and feasibility were undertaken and costs of intervention calculated.

Results  Sixteen of the 23 participants recruited completed the study. Mean estimated energy derived from the snacks provided 26% of daily energy requirements. Monitoring adherence proved problematic and stocktakes highlighted discrepancies. Although several participants reported that they did not usually eat between meals, overall the intervention was acceptable to participants. The cost of implementation was £21.29 per participant per week.

Conclusions  Although it proved feasible, practical difficulties were encountered with implementation and adherence due to timing. A more appropriate time to deliver such an intervention may be after the acute phase is over and patients are back home. The costs compared favourably with the alternative of providing sip feeds.
Reliability and validity of a maternal food frequency questionnaire designed to estimate consumption of common food allergens
Authors: Venter C. , Higgins B. , Grundy J. , Clayton C. B. , Gant C. , Dean T.
Published: March 2006

Background Maternal food intake during pregnancy may influence the development of food hypersensitivity (FHS) in the child. A food frequency questionnaire estimating the frequency with which some of the mains food allergens are consumed was designed and validated.

Materials and methods Pregnant women were recruited at the ante‐natal clinic of St. Mary's Hospital, Isle of Wight, UK. A food frequency questionnaire was developed and validated by comparing responses to information recorded in 7 days food diaries. The reliability of the food frequency questionnaire was evaluated by asking women to complete the questionnaire on two separate occasions at 30 and 36 weeks gestation.

Results Fifty‐seven women completed the validity study and 91 women completed the reliability study. For both validity and reliability, questions with dichotomous response categories showed the highest level of agreement. Frequency of intake of foods commonly ‘hidden’ in foods produced the lowest validity and reliability scores. In the validity study responses to the food frequency questionnaire identically matched information recorded in the food diaries 80% of the time, on average. In the reliability study, responses were identical on both questionnaires 85% of the time on average.

Conclusion In this study a food frequency questionnaire estimating the frequency with which some of the main food allergens are consumed during pregnancy was designed and validated. This food frequency questionnaire could be used in future studies to assess the role of maternal food intake in the development of FHS in the infant.
Reproduction Phase‐Related Expression of β‐Endorphin‐Like Immunoreactivity in the Nucleus Lateralis Tuberis of the Female Indian Major Carp Cirrhinus mrigala: Correlation with the Luteinising Hormone Cells‐Ovary Axis
Authors: Sakharkar A. J. , Singru P. S. , Mazumdar M. , Subhedar N.
Published: March 2006

The present study aimed to determine whether β‐endorphin immunoreactivity (bEP‐ir) in the neurones of the nucleus lateralis tuberis (NLT) is linked to the seasonal cycle and shows correlation with the number of luteinising hormone (LH) cells in the pituitary gland and ovaries in the teleost, Cirrhinus mrigala. Although LH cells were moderately immunostained during the resting phase (December to January), the morphological profile suggested increased synthetic and secretory activity during the preparatory (February to April) and prespawning (May to June) phases. However, LH immunoreactivity was greatly reduced (P < 0.001) in the spawning (July to August) phase, suggesting massive discharge of the hormone; this pool was partly replenished in the postspawning (September to November) phase. The ovaries grew rapidly in the preparatory and prespawning phases; maximal size was attained during spawning, when ovulation occurred. Thereafter, the ovaries regressed. The NLT of C. mrigala is divisible into the pars lateralis (NLTl) and medialis (NLTm). During the postspawning and resting phases, bEP‐ir was readily detectable in the NLTm as well as NLTl neurones. However, a steady reduction in the immunoreactivity was observed in the NLTm neurones during the preparatory through spawning phases (P < 0.001), suggesting a negative correlation with the LH cells‐ovary axis. Thus, the inhibitory influence of β‐endorphin on the gonadotrophin‐releasing hormone (GnRH)‐LH axis appears to be attenuated during the preparatory through spawning phases. This may be necessary for the rapid stimulation of the axis culminating in spawning. Neurones of the NLTl also showed a gradual reduction in bEP‐ir during the preparatory and prespawning phases (P < 0.01) and may therefore play a similar role. However, significant augmentation of the immunoreactivity was noticed in these neurones during the spawning phase (P < 0.001), the physiological significance of which is unknown. Although the present study demonstrated a temporal correlation between the β‐endorphin in the NLT, LH cells and the ovary, we suggest that the peptide in the NLTl and NLTm may show functional duality during the spawning phase.
Differential Effects of Acute and Chronic Social Defeat Stress on Hypothalamic‐Pituitary‐Adrenal Axis Function and Hippocampal Serotonin Release in Mice
Authors: Keeney A. , Jessop D. S. , Harbuz M. S. , Marsden C. A. , Hogg S. , Blackburn‐Munro R. E.
Published: March 2006

Hyperactivity of the hypothalamic‐pituitary‐adrenal (HPA) stress axis and disturbances in serotonin (5‐HT) neurotransmission have been implicated in the pathogenesis of depressive disorder. Repeated social defeat of male NMRI mice has been shown to induce increases in core body temperature and corticosterone, indicative of a state of chronic stress in subordinate animals. The present study further characterised the HPA axis response to social defeat stress, and also examined hippocampal extracellular 5‐HT release during the stress. Exposure to an acute social defeat elicits increases in plasma adrenocorticotrophic hormone and corticosterone levels, peaking at 15 and 30 min, respectively, and enhances corticotrophin‐releasing factor (CRF) mRNA, but not arginine vasopressin (AVP) mRNA within the medial parvocellular division of the hypothalamic paraventricular nucleus. A concomitant increase in hippocampal corticosterone and 5‐HT levels is observed. By contrast, although chronic social defeat is associated with greatly elevated corticosterone levels, the predominant drive appears to be via parvocellular AVP rather than CRF. Furthermore, subordinate animals allowed to recover for 9 days after chronic social defeat display an increase in immobility in the forced swimming model of depression, indicating that animals previously exposed to the homotypic defeat stress are sensitised to the behavioural effects of a novel stressor. These results demonstrate that social defeat induces prolonged activation of the HPA axis and alterations in 5‐HT neurotransmission that could be of relevance to some of the pathological abnormalities observed in clinical depression.
The large peculiar velocity of the cD galaxy in Abell 3653
Authors: Pimbblet Kevin A. , Roseboom Isaac G. , Doyle Marianne T.
Published: March 2006

We present a catalogue of galaxies in Abell 3653 from observations made with the 2-degree field (2dF) spectrograph at the Anglo-Australian Telescope. Of the 391 objects observed, we find 111 are bona fide members of Abell 3653. We show that the cluster has a velocity of cz= 32 214 ± 83 km s−1 (z= 0.10 738 ± 0.00 027), with a velocity dispersion typical of rich, massive clusters of σcz= 880+66−54. We find that the cD galaxy has a peculiar velocity of 683 ± 96 km s−1 in the cluster rest frame – some 7σ away from the mean cluster velocity, making it one of the largest and most significant peculiar velocities found for a cD galaxy to date. We investigate the cluster for signs of substructure, but do not find any significant groupings on any length scale. We consider the implications of our findings on cD formation theories.
Growth‐associated protein 43 in lesions and cerebrospinal fluid in multiple sclerosis
Authors: Teunissen C. E. , Dijkstra C. D. , Jasperse B. , Barkhof F. , Vanderstichele H. , Vanmechelen E. , Polman C. H. , Bö L.
Published: March 2006

Axonal damage in multiple sclerosis (MS) is correlated to disease progression. Early axonal damage may be compensated for by regenerative processes. Growth‐associated protein 43 (GAP‐43) is a marker for axonal growth and synaptogenesis in various neurodegenerative diseases. We investigated the expression of GAP‐43 in 48 MS grey and white matter lesions of different stages. Decreased GAP‐43 expression was found in 74% of the white matter lesions, independent of the lesion stage. In 19 out of 35 white matter lesions, areas of increased GAP‐43 expression were present immediately adjacent to the lesions. Increased or unaltered expression was observed in remyelinated lesions. GAP‐43 was expressed in neurofilament‐positive structures. GAP‐43 expression appeared unchanged in grey matter lesions. Macrophages were present in the areas of changed GAP‐43 expression. cerebrospinal fluid GAP‐43 levels were negatively correlated with magnetic resonance imaging measures of whole‐brain atrophy (r = −0.30). In conclusion, these results indicate that decreased GAP‐43 immunopositivity reflects axonal damage in MS lesions, which may again be reflected in decreased cerebrospinal fluid levels. The increased levels of GAP‐43 in remyelinated or nondemyelinated white matter close to MS lesions may reflect regenerative attempts by damaged axons.
Relationships in Alzheimer's disease between the extent of Aβ deposition in cerebral blood vessel walls, as cerebral amyloid angiopathy, and the amount of cerebrovascular smooth muscle cells and collagen
Authors: Tian J. , Shi J. , Smallman R. , Iwatsubo T. , Mann D. M. A.
Published: March 2006

The relationship between degree of cerebral amyloid angiopathy (CAA) and the amount of smooth muscle cells (SMCs) and deposition of collagen IV fibres (COL IV) was investigated in the frontal and occipital cortex of 70 patients with autopsy confirmed Alzheimer's disease (AD). The extent of CAA was significantly greater in occipital than in frontal cortex, although SMC loss was greater in frontal than in occipital cortex. COL IV staining was significantly higher in occipital than in frontal cortex. The degree of SMC loss correlated with CAA, as Aβ40 but not as Aβ42 or total Aβ, in frontal cortex, but not in occipital cortex. Leptomeningeal arteries within occipital cortex showed significantly greater external diameter, greater wall thickness and greater luminal area than those in frontal cortex. The degree of CAA correlated with thickness of blood vessel wall and external diameter in frontal cortex, whereas extent of SMC loss correlated with thickness of blood vessel wall in occipital cortex. There were significant negative correlations between duration of disease and thickness of vessel wall, external diameter and luminal area. In patients with disease durations exceeding 10 years, external vessel diameter and thickness of the vessel wall were both halved compared with patients with durations less than 5 years; luminal area was reduced by about 75%. Blood vessels in AD undergo degenerative changes involving deposition of Aβ and COL IV with loss of SMC. SMC loss may relate to increasing Aβ deposition in early stages of disease, but this relationship may be lost with disease progression.
Managing sulphur metabolism in plants
Authors: HAWKESFORD MALCOLM J. , DE KOK LUIT J.
Published: March 2006

Resolution and analysis of genes encoding components of the pathways of primary sulphur assimilation have provided the potential to elucidate how sulphur is managed by plants. Individual roles for members of gene families and regulatory mechanisms operating at gene, cellular and whole plant levels have been recognized. Sulphur is taken up and transported around the plant principally as sulphate, catalysed for the most part by a single gene family of highly regulated transporters. Additional regulation occurs in the pathway of reduction of sulphate to sulphide and its incorporation into cysteine, which occurs principally within the plastid. Cellular and whole‐plant regulation of uptake, and the assimilatory pathway attempt to balance supply with demand for growth and include mechanisms for re‐mobilization and redistribution of sulphur. Furthermore, optimization of sulphur assimilation requires coordination with carbon and nitrogen pathways, and multiple processes have been proposed to contribute to this balance. Present studies on cis and trans elements are focusing on transcriptional regulation, but this regulation still needs to be linked to apparent metabolite sensing. Whilst the components of the assimilatory pathways have been resolved after many years of controversy, uncertainties remain concerning roles of individual genes in gene families, their sub‐cellular localization and their significance in balancing sulphur flux to sulphur demand of the plant for growth under variable environmental conditions.
Brassinosteroids and plant function: some clues, more puzzles
Authors: HAUBRICK L. L. , ASSMANN S. M.
Published: March 2006

The role of brassinosteroids (BRs) in plant function has been intensively studied in the last few years. Mutant analysis has demonstrated that the ability to synthesize, perceive and respond to BRs is essential to normal plant growth and development. Several key elements of BR response have been identified using both genetic and biochemical approaches, and molecular models that parallel Wingless (Wnt), transforming growth factor β (TGFβ) and receptor tyrosine kinase (RTK) signalling in animals have been proposed. Many studies have demonstrated the role of BRs, alone and in interaction with other plant hormones, in processes such as cell elongation and seed germination. In contrast, little is known about how the sensing of BRs is connected to specific physiological responses such as stress resistance. There remain many open questions about how these connections are made.
Transgenic approaches to manipulate the environmental responses of the C3 carbon fixation cycle
Authors: RAINES CHRISTINE A.
Published: March 2006

The limitation to photosynthetic CO2 assimilation in C3 plants in hot, dry environments is dominated by ribulose 1·5‐bisphosphate carboxylase/oxygenase (Rubisco) because CO2 availability is restricted and photorespiration is stimulated. Using a combination of genetic engineering and transgenic technology, three approaches to reduce photorespiration have been taken; two of these focused on increasing the carboxylation efficiency of Rubisco either by reducing the oxygenase reaction directly or by manipulating the Rubisco enzyme by concentrating CO2 in the region of Rubisco through the introduction of enzymes of the C4 pathway. The third approach attempted to reduce photorespiration directly by manipulation of enzymes in this pathway. The progress in each of these areas is discussed, and the most promising approaches are highlighted. Under saturating CO2 conditions, Rubisco did not limit photosynthesis, and limitation shifted to ribulose bisphosphate (RuBP) regeneration capacity of the C3 cycle. Transgenic analysis was used to identify the specific enzymes that may be targets for improving carbon fixation, and the way this may be exploited in the high CO2 future is considered.
Functional dynamics of plant growth and photosynthesis – from steady‐state to dynamics – from homogeneity to heterogeneity
Authors: SCHURR U. , WALTER A. , RASCHER U.
Published: March 2006

Plants are much more dynamic than we usually expect them to be. This dynamic behaviour is of paramount importance for their performance under natural conditions, when resources are distributed heterogeneously in space and time. However, plants are not only the cue ball of their physical and chemical environment. Endogenous rhythms and networks controlling photosynthesis and growth buffer plant processes from external fluctuations. This review highlights recent evidence of the importance of dynamic temporal and spatial organization of photosynthesis and of growth in leaves and roots. These central processes for plant performance differ strongly in their dependence on environmental impact and endogenous properties, respectively. Growth involves a wealth of processes ranging from the supply of resources from external and internal sources to the growth processes themselves. In contrast, photosynthesis can only take place when light and CO2 are present and thus clearly requires ‘input from the environment’. Nevertheless, growth and photosynthesis are connected to each other via mechanisms that are still not fully understood. Recent advances in imaging technology have provided new insights into the dynamics of plant–environment interactions. Such processes do not only play a crucial role in understanding stress response of plants under extreme environmental conditions. Dynamics of plants under modest growth conditions rise from endogenous mechanisms as well as exogenous impact too. It is thus an important task for future research to identify how dynamic external conditions interact with plant‐internal signalling networks to optimize plant behaviour in real time and to understand how plants have adapted to characteristic spatial and temporal properties of the resources from their environment, on which they depend on.
Conformation of the Equine Skull: A Morphometric Study
Authors: Evans K. E. , McGreevy P. D.
Published: March 2006

There is a lack of an established method for quantifying equine skull morphology. This study proposes a method that is valid for use on both live and deceased horses. A total of nine head measurements (skull length, cranial length, nasal length, ratio of cranial:nasal length, cranial width, zygomatic width, mandibular depth, nasal profile area, cranial profile area) and six indices (skull index, cranial index, nasal index, mandibular index, nasal profile index, cranial profile index) were recorded from 30 horses from a variety of breeds whilst the soft tissues of the head were intact. A line was drawn level with the palpable notches caudal to the caudal lacrimal process of each orbit to estimate the suture line of the nasal and frontal bones and distinguish between the neurocranium and splanchnocranium. There were positive correlations between many of the head measurements. This method also illustrated significant differences in the skull morphology of three breeds (Arabians, thoroughbreds and standardbreds).
Morphological Study of the Transition of Haematopoietic Sites in the Developing Mouse During the Peri‐natal Period
Authors: Tada T. , Widayati D. T. , Fukuta K.
Published: March 2006

The transition of fetal haematopoietic sites in mice was examined histologically from 12.5‐day embryos (E12.5) until 10 days of age (D10), and the expression of the adhesive molecules VCAM‐1 and fibronectin was examined immunohistologically. Erythropoiesis occurred in the liver (E12.5–18.5), spleen (E18.5–D4) and bone marrow (D6–10), in that sequence. Even at D10, some erythropoiesis occurred in the liver, and more so in the spleen, although the active haematopoietic site was the bone marrow. Similarly, granulopoiesis of neutrophils occurred in the liver, spleen and bone marrow in turn. Granulopoiesis still occurred in the spleen at D10, but no neutrophils were found in the liver after D4. VCAM‐1 appeared in the liver, spleen and bone marrow in parallel with active erythropoiesis and granulopoiesis. The co‐expression of VCAM‐1 and fibronectin was recognized in the endothelial cells of the sinus at the onset of haematopoiesis. This study showed that haematopoiesis in the liver, spleen and bone marrow overlapped peri‐natally, although it shifted sequentially. VCAM‐1 appears to be closely associated with erythropoiesis and granulopoiesis, and the co‐expression of VCAM‐1 and fibronectin plays a role in inducing haematopoietic stem cells to move to the tissues.
Components of Partial Disease Resistance in Wheat Detected in a Detached Leaf Assay Inoculated with Microdochium majus using First, Second and Third Expanding Seedling Leaves
Authors: Browne R. A. , Mascher F. , Golebiowska G. , Hofgaard I. S.
Published: March 2006

The use of first, second and third expanding seedling leaves of wheat (L1, L2 and L3 respectively), inoculated with conidial suspensions of Microdochium majus (syn. Microdochium nivale var. majus) in a detached leaf assay, for detecting components of partial disease resistance (PDR) was investigated across a range of wheat cultivars. Incubation periods (period from inoculation to first appearance of symptoms; a dull grey–green water‐soaked lesion) and latent periods (period from inoculation to the first appearance of sporodochia) were longest and lesions smallest on L3. The expression of PDR components on L2 was intermediate to those on L1 and L3. The longer latent periods on L3 typically occurred after leaf senescence contrasting with latent periods on L1 and L2 where sporulation most frequently occurred on relatively green leaf tissue. Cultivar differences in the first appearance of symptoms, incubation period, which occurred before any leaf senescence was observed, correlated significantly across all leaf positions. Similarly cultivar differences in latent period were correlated for L1 and L2. However, latent periods on L3, which were the least consistent between cultivars across experiments, were not correlated with those of L1 or L2 in any experiment. The results indicate that due to the delay in sporulation until after leaf senescence, observations on latent period in L3 are less representative of what occurs in the whole plant where infection of living tissue is of greatest interest. This work indicates that the selection of the first or second expanding leaf of wheat is optimal for the use in the detached leaf assay using M. majus for studying components of PDR.
Development of a Rapid RT‐PCR Test for the Detection of Peach Latent Mosaic Viroid, Pear Blister Canker Viroid, Hop Stunt Viroid and Apple Scar Skin Viroid in Fruit Trees from Tunisia
Authors: Fekih Hassen I. , Roussel S. , Kummert J. , Fakhfakh H. , Marrakchi M. , Jijakli M. H.
Published: March 2006

A reverse transcription polymerase chain reaction was developed to investigate the occurrence of ‘peach latent mosaic viroid’ (PLMVd), ‘pear blister canker viroid’ (PBCVd), ‘hop stunt viroid’ (HSVd) and ‘apple scar skin viroid’ (ASSVd) on fruit trees (peach, pear, almond and apple) in Tunisia. The test was initially performed with total RNA preparations from selected isolates and then applied to total RNA preparations from leaf or bark tissues of fruit trees collected in the north of Tunisia and the Sahel. PLMVd was found to occur in peach and pear trees, HSVd in pear, peach and almond trees, and PBCVd in pear trees. Mixed PBCVd–HSVd and PLMVd–HSVd infections occurred naturally in pear trees. ASSVd was not detected in any samples from apple trees. The identity of the detected viroids was confirmed by comparing their sequences with those of other previously characterized isolates. The test was then simplified by direct use of diluted crude plant extracts. The results obtained from crude sap extracts of leaves or bark tissues and from total RNA preparations were identical. This improved test is thus quick and useful for large‐scale routine analysis. It can be used in a certification programme to contribute to prevention of the occurrence and spread of PLMVd, HSVd, PBCVd and ASSVd in Tunisia.
Rosellinia aquilaAmong Fungi on Branches of Sessile Oak with Symptoms of Decline
Authors: Kwaśna H. , ŁAkomy P.
Published: March 2006

Rosellinia aquilawas found for the first time in crowns of sessile oaks,Quercus robur(Mattuschka) Liebl., with symptoms of decline. The fungus occurred mostly on diseased branches but also colonized twigs with healthy appearance. Its anamorph and teleomorph stages were produced abundantly on dead branches after long incubation in moist conditions. Colonization of oak trees byR. aquilawas likely to have been facilitated by higher humidity and temperature in the oak stands.