bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential induction of CD94 and NKG2 in CD4 helper T cells. A consequence of influenza virus infection and interferon‐γ?
Authors: Graham Christine M. , Christensen Jillian R. , Thomas D. Brian
Published: February 2007

Influenza A virus causes worldwide epidemics and pandemics and the investigation of memory T helper (Th) cells that help maintain serological memory following infection is important for vaccine design. In this study we investigated CD94 and NKG2 gene expression in memory CD4 T‐cell clones established from the spleens of C57BL/10 (H‐2b) and BALB/c (H‐2d) mice infected with influenza A virus (H3N2). CD94 and NKG2A/C/E proteins form heterodimeric membrane receptors that are involved in virus recognition. CD94 and NKG2 expression have been well characterized in natural killer (NK) and cytotoxic T cells. Despite CD94 being potentially an important marker for Th1 cells involved in virus infection, however, there has been little investigation of its expression or function in the CD4 T‐cell lineage and no studies have looked at in‐vivo‐generated Th cells or memory cells. We show in this study that in‐vivo‐generated CD4 Th1 cells, but not Th2 cells, exhibited full‐length CD94 and NKG2A gene expression following activation with viral peptide. For NKG2A, a novel ‘short’ (possibly redundant) truncated isoform was detectable in a Th2 cell clone. Another member of the NK receptor family, NKG2D, but not NKG2C or E, was also differentially expressed in Th1 cells. We show here that CD94 and NKG2A may exist as multiple isoforms with the potential to distinguish helper T‐cell subsets.
Decrease and dysfunction of dendritic cells correlate with impaired hepatitis C virus‐specific CD4+ T‐cell proliferation in patients with hepatitis C virus infection
Authors: Della Bella Silvia , Crosignani Andrea , Riva Antonio , Presicce Pietro , Benetti Alberto , Longhi Renato , Podda Mauro , Villa Maria L.
Published: February 2007

Through the production of stimulatory and suppressive cytokines, dendritic cells (DCs) regulate virus‐specific immune responses that are crucial to virus eradication. To explore a possible role of DCs in the persistence of hepatitis C virus (HCV) infection, in this study we analysed peripheral blood DCs (PBDCs) in patients with chronic hepatitis C (CHC) compared with those in both healthy seronegative (HSN) controls and a group of subjects who had spontaneously resolved infection, defined as healthy HCV‐seropositive (HSP), and we evaluated the relationships between PBDCs and HCV‐specific CD4+ T‐cell reactivity. The number of PBDCs, their immunophenotype and expression of regulatory cytokines were evaluated by flow cytometry on whole‐blood samples. HCV‐specific CD4+ T‐cell activation, proliferation and cytokine production were evaluated in cultures of peripheral blood mononuclear cells (PBMCs) stimulated in vitro with HCV peptides. We found that PBDCs from CHC subjects were numerically reduced and showed lower interleukin‐12 (IL‐12) and higher IL‐10 expression than those from HSN controls. PBDCs from HSP subjects were similar to those from HSN controls. HCV‐specific CD4+ T‐cell proliferation was less frequent and vigorous in CHC than in HSP patients and was directly related to the number of PBDCs and their IL‐12 production but inversely related to their IL‐10 production. Taken together, these results seem to suggest that cytokines of DC origin contribute to the regulation of HCV‐specific immunity in CHC patients and indicate that PBDCs may represent a novel non‐invasive tool for immune monitoring of these patients.
Sealer area associated with cold lateral condensation of gutta‐percha and warm coated carrier filling systems in canals prepared with various rotary NiTi systems
Authors: Gulsahi K. , Cehreli Z.C. , Kuraner T. , Dagli F.T.
Published: February 2007

Aim  To compare the area of sealer surrounding root fillings completed by two coated carrier systems (Thermafil Obturator and System GT Obturator) and the cold lateral compaction technique, following root canal preparation with two different NiTi rotary systems (Profile ISO and System GT).

Methodology  Sixty extracted human mandibular premolars were instrumented with ProFile ISO 0.06 taper and System GT instruments (n = 30 each). The teeth were divided into four subgroups (n = 15) for filling as following: group 1: ProFile + Thermafil Obturator, group 2: ProFile + Cold Lateral Compaction, group 3: System GT + GT Obturator, and group 4: System GT + Cold Lateral Compaction. In all groups the canals were prepared to a final size of 40, 0.06 taper in accordance with the manufacturer's instructions and Topseal was used as a sealer. Horizontal sections were obtained every 1 mm up to 12 mm from the apical foramen. Sections were digitally photographed under a stereomicroscope and the images were transferred to an IBM‐compatible PC for image analysis. The cross‐sectional area of the root canal and the area filled by sealer were calculated for each section and compared statistically both at all levels and by grouping the data as apical, middle and coronal segments; using the Kruskal–Wallis test with Bonferroni correction and chi‐square tests (P = 0.05).

Results  In the apical third (1–4 mm), the GT Obturator (group 3) had significantly less area of sealer (P < 0.05), while the difference between groups 1 and 2 was not significant (P > 0.05). For the middle and coronal thirds, both coated‐carrier systems had significantly less area of sealer compared with their laterally compacted counterparts (P < 0.05).

Conclusions  With the combined use of ProFile + Thermafil Obturator and System GT + GT Obturator, significantly less area of sealer occurred than that achieved with both NiTi preparation systems followed by cold lateral compaction.
A comparison between two electronic apex locators: an ex vivo investigation
Authors: Venturi M. , Breschi L.
Published: February 2007

Aim  To compare ex vivo the performance of the Apex Finder and the Root ZX apex locators, with and without irrigant, in canals having different diameters.

Methodology  Sixty canals in 60 teeth were prepared using stainless steel hand files and 0.04 taper NiTi rotary instruments. During preparation the narrowest diameter of the canal was transported to the apical root surface. The canals were irrigated with RC‐Prep and 5% NaOCl solution. Six groups were obtained, each with 10 canals having the same diameter of foramen, either 0.15, 0.20, 0.25, 0.40, 0.60 and 0.80 mm. A size 15 K‐file was advanced into each canal until its tip was observed under ×10 magnification to reach the foramen and the corresponding length recorded. The measurements were performed to an accuracy of 0.25 mm as a base unit of length. The teeth were then fixed to a plastic bar suspended over a glass container filled with 0.9% NaCl solution. Each apex locator was tested when the K‐file was at the foramen, or 0.5, 1.0, 1.5 and 2.0 mm short; with the root apex immersed into the solution; with the canal dry or irrigated with NaCl. To evaluate the accuracy of both electronic apex locators (EALs) each electronically determined distance was compared with the actual length and the data analysed using the General Linear Model and the Student t‐test.

Results  Out of 2400 measurements 100 were electrically unstable, all with the Root ZX. In total, 521 measurements located the position of the file tip beyond the apex, in general, in high conductive conditions with the Root ZX and in low conductive conditions with the Apex Finder. No significant difference in terms of accuracy was found between the two EALs when the file tip was at the foramen (Root ZX mean +0.12 mm, SD 1.22 mm; Apex Finder mean +0.57 mm, SD 1.16 mm). Comparing all the measurements performed with the file tip within 2 mm of the foramen, in all the different conditions tested, the accuracy was affected (P < 0.025) by diameter of the foramen, type of EAL, distance to the apex, and by several interactions.

Conclusions  Under the different ex vivo conditions both EALs provided accurate measurements when the file tip was at the foramen. The accuracy of the Apex Finder was negatively influenced by high conductive conditions, whilst the Root ZX provided inaccurate and unstable measurements mostly in low conductive conditions.
Cytotoxicity of new resin‐, calcium hydroxide‐ and silicone‐based root canal sealers on fibroblasts derived from human gingiva and L929 cell lines
Authors: Eldeniz A. U. , Mustafa K. , Ørstavik D. , Dahl J. E.
Published: February 2007

Aim  To assess ex vivo the cytotoxic effects of five new root canal sealers (RC Sealer, Epiphany, EndoREZ, GuttaFlow and Acroseal) and three existing products (AH Plus, RoekoSeal and Apexit) using primary human gingival fibroblasts (HGF) and a mouse fibroblast cell line, L929.

Methodology  Eight samples of each sealer were fabricated in sterile cylindrical Teflon blocks, 4.4 mm diameter and 2 mm height and then divided into two groups, fresh and aged specimens. Extraction of fresh specimens was carried out after setting whilst aged specimens were placed in Petri dishes and kept in a humid chamber at 37 °C for 7 days before extraction in cell culture medium using the ratio 1.25 cm2 mL−1. Undiluted eluates were used for the dimethylthiazol diphenyltetrazolium bromide (MTT) assay with HGF and L‐929. Morphology of HGF cells was also examined by an inverted microscope using undiluted eluates of the sealers. The results were analysed using a two‐tailed t‐test (α = 0.05) between groups.

Results  Resin‐based (Epiphany and EndoREZ) and calcium hydroxide‐based (Apexit and Acroseal) sealers were significantly more cytotoxic than other sealers (P < 0.05). However, L929 cells were more sensitive to Apexit and EndoREZ than HGF cells. RC Sealer showed mild cytotoxicity to HGF at both setting times. AH Plus did not exert any cytotoxic effect to HGF and aged specimens appeared to induce cellular proliferation. RoekoSeal and GuttaFlow also demonstrated mild cytotoxicity. GuttaFlow was slightly more cytotoxic to both cultures, especially when tested fresh.

Conclusions  Toxicity varied but RC Sealer and GuttaFlow were the least toxic new sealers.
The impact of predator control on lapwing Vanellus vanellus breeding success on wet grassland nature reserves
Authors: BOLTON MARK , TYLER GLEN , SMITH KEN , BAMFORD ROY
Published: February 2007

Whilst the widespread declines in breeding grassland waders in many parts of Europe have been associated with changes in agriculture, there is concern that predation may compromise recovery of wader populations, even in situations where habitat is suitable, such as nature reserves managed for breeding waders.

An 8‐year cross‐over experiment was used to examine the effect of red fox Vulpes vulpes and carrion crow Corvus corone control on breeding performance and population trends of lapwing Vanellus vanellus on 11 lowland wet grasslands.

Predator densities in the absence of control measures were highly variable among sites, and consequently the numbers of predators removed were similarly variable. Overall, predator control measures resulted in a 40% decline in adult fox numbers and a 56% reduction in territorial crows.

There was no overall effect of predator control on the failure rate of 3139 lapwing nests. However, the effect of predator control varied significantly among sites, reflecting the variation in predator densities. Predator control measures were more likely to result in increased nest survival at sites where predator densities were high.

Nest‐temperature loggers deployed at seven sites indicated that 88% of nest predations occurred during darkness, suggesting nocturnal mammalian predators.

At seven sites predator control had no overall effect on chick survival, monitored by radio‐tracking 459 chicks, but there were differences in the effect of predator control among sites. Densities of predators were low during years without predator control measures at the majority of these sites.

At six further sites breeding success, assessed from the proportion of adults accompanied by young late in the season, was twice as high in years when predators were controlled.

There was no overall effect of predator control on lapwing population trends across the experimental sites.

Synthesis and applications. This study highlights the need for information on predator densities and the impact of predators on nest and chick survival, before embarking on predator control measures at a particular site. A decision tree for determining the circumstances in which fox and/or crow control may be both necessary and effective is recommended.
Personality disorders in people with learning disabilities: a community survey
Authors: Khan A. , Cowan C. , Roy A.
Published: February 2007

The prevalence of personality disorders has been determined by studies of both the general population and mental handicap hospitals. The present study attempts to determine the prevalence of personality disorders in a community sample and to check the implications for treatment A community sample of learning disability service users was surveyed by obtaining a rating from a good informant to establish demographic data, level of functioning and the nature of personality disorders, if any, using the ICD‐I0 version of the Standardized Assessment of Personality (SAP). Fifty per cent of the sample had personality abnormalities, and 31% had sufficient impairment of the social and occupational domains and personal distress to warrant a diagnosis of personality disorder. These findings are compared with previous studies. Paranoid, schizoid, impulsive and dissocial personality abnormalities were seen to be associated with a high referral rate to psychiatric services and needed considerable therapeutic input The prevalence of personality abnormalities in community populations with a learning disability is high. The SAP is a useful instrument for screening. This sub‐population makes significant demands on community psychiatric services.
A follow‐up study of prescribing for people with learning disabilities previously in National Health Service care in Leicestershire, England
Authors: Branford D.
Published: February 2007

A 6‐year follow‐up was undertaken of 486 people with learning disabilities who in 1990 had lived in institutional care. Despite changes to the nature of accommodation and an extensive drug review programme, the overall proportion of people receiving the different categories of psychotropic drugs remained similar in 1990 and 1996. Only the prescribing of antidepressants was markedly changed. Contrary to expectations the prevalence of prescribing of many psychotropic drugs rose in the community settings.
Comments on the Reiss Screen for Maladaptive Behaviour and its factor structure
Authors: Reiss S.
Published: February 2007

Sturmey's factor analysis of the Reiss Screen for Maladaptive Behaviour is based upon several significant errors, some of which are of general interest because misuse of factor analysis is common (Ford et al. 1986). In this commentary, the author discusses: the concept of factor robustness; appropriate samples for evaluating the factor structure of a dual diagnosis instrument; the differences between exploratory and confirmatory analyses; and how the Reiss Screen was intended to fulfill its purpose. In the Sturmey study, the Reiss Screen may have actually performed well under adverse conditions. The criteria for conducting valid factor analytic studies of dual diagnosis instruments are identified in order to encourage future research evaluating the Reiss Screen and other instruments.
Diagnosis of sensory impairment in people with intellectual disability in general practice
Authors: Evenhuis H. M. , Mul M. , Lemaire E. K. G. , de Wijs J. P. M.
Published: February 2007

The present authors have participated in the development of a Dutch consensus on the early detection, diagnosis and treatment of hearing and visual impairment in children and adults with intellectual disability. They argue that the early detection of sensory impairment in babies and children with intellectual disability should primarily be a responsibility of paediatricians and youth health physicians. General practitioners should be aware of the necessity of screening and should check whether this has been done when children visit the surgery. It is stressed that the general practitioner should play a more active role in the detection of age‐related sensory loss in older adults with intellectual disability, and the assessment of younger adults whose sensory functions have never or incompletely been evaluated. Annual sensory screening is certainly not necessary, but annual otoscopy to detect impacted earwax or unidentified middle ear infection, as well as checks of the proper use of glasses and hearing aids, are suggested. Most adults with mild or moderate intellectual disability can be assessed with methods that are normally used by general practitioners.

Uncooperative people should be referred for screening with specialized methods. A low‐threshold referral system (e.g. via district expert teams) has been outlined.
A population‐based health survey of maladaptive behaviours associated with dementia in elderly people with learning disabilities
Authors: Cooper S.‐A.
Published: February 2007

Maladaptive behaviours are known to present as a feature of dementia amongst people from the general population, but there has been little research to examine whether this has implications for people with learning disabilities who develop dementia. Out of 143 people with learning disabilities aged 65 years and over living in Leicestershire, England, 134 (93.7%) participated in the study. Twenty‐nine people diagnosed as having dementia were compared against 99 people without dementia; six people with possible dementia were excluded from the analysis. Comparisons were made on the results of a checklist of maladaptive behaviours. Seventeen out of the 22 maladaptive behaviours examined were found to be more prevalent amongst the people with dementia. The behaviours which were significantly more prevalent in the group with dementia included lack of energy, lack of sense of danger, sleep disturbance, agitation, incontinence, excessively uncooperative, mealtime/ feeding problem, irritability and aggression. Dementia is becoming more prevalent amongst people with learning disabilities because of their increasing life span. Maladaptive behaviours are commonly associated with dementia. This can cause a significant burden for individuals and their carers, which may influence the viability of a person's residential placement.
Measuring staff perceptions of challenging behaviour: the Challenging Behaviour Attributions Scale (CHABA)
Authors: Hastings R. P.
Published: February 2007

Causal attributions may interact with other variables to determine staff responses to challenging behaviour. Furthermore, staff perceptions of the causes of challenging behaviour are likely to change as a result of theoretical and practical training. However, there is no established simple method for measuring staff attributions that could facilitate research in these areas. The present paper describes the development and preliminary psychometric analysis of the Challenging Behaviour Attributions Scale (CHABA).
Psychological well‐being of staff working with people who have challenging behaviour
Authors: Jenkins R. , Rose J. , Lovell C.
Published: February 2007

The present survey explored stress in direct‐care staff working with people who have learning disabilities and challenging behaviour. A total of 78 (82.7% response rate) staff working in 14 small community houses participated. Houses were selected on the basis of ‘expert’ (Head of Psychology Services) knowledge of houses where residents were known to display challenging behaviour and houses where there was no known history of challenging behaviour. Residents were assessed by key workers for adaptive behaviour, challenging behaviour and mental health using partially validated questionnaires. Staff completed self‐report questionnaires on job demands, anxiety and depression, staff support, and information on the presence/absence of challenging behaviour in their home. Staff working in houses with residents who showed challenging behaviour were significantly more anxious than staff working in houses with no challenging behaviour; they also reported feeling significantly less supported, were less clear about the identification of risk situations and had lower job satisfaction. No differences were found on measures of job demands and depression. Regression analyses exploring the relationships between these variables are discussed along with the implications of the findings.
Intellectual and adaptive behaviour functioning in pantothenate kinase‐associated neurodegeneration
Authors: Freeman K. , Gregory A. , Turner A. , Blasco P. , Hogarth P. , Hayflick S.
Published: February 2007

Background  Pantothenate kinase‐associated neurodegeneration (PKAN), an extremely rare autosomal recessive disorder resulting in iron accumulation in the brain, has a diverse phenotypic expression. Based on limited case studies of one or two patients, intellectual impairment is considered part of PKAN. Investigations of cognitive functioning have utilized specific neuropsychological tests, without attention to general intellectual skills or adaptive behaviour.

Methods  Sixteen individuals with PKAN completed measures of global intellectual functioning, and participants or care providers completed measures of adaptive behaviour skills and day‐to‐day functional limitations. Clinicians provided global ratings of condition severity.

Results  Testing with standardized measures documented varied phenotypic expression, with general cognitive skills and adaptive behaviour ranging from high average to well below average. Age of disease onset correlated with measures of intellectual functioning, adaptive functioning and disease severity.

Conclusions  Findings support previously described clinical impressions of varied cognitive impairment and the association between age of onset and impairment. Further, they add important information regarding the natural history of the disease and suggest assessment strategies for use in treatment trials.
Age‐related change in the association between a polymorphism in the PER3 gene and preferred timing of sleep and waking activities
Authors: JONES KAY H. S. , ELLIS JASON , VON SCHANTZ MALCOLM , SKENE DEBRA J. , DIJK DERK‐JAN , ARCHER SIMON N.
Published: February 2007

The objective of this study was to investigate the effect of age on the association between preferred timing of sleep and waking activities and a coding‐region variable number tandem repeat (VNTR) polymorphism in the clock gene PER3. We have previously reported this polymorphism to associate with diurnal preference and delayed sleep phase syndrome (DSPS). Participants (n = 1590; 707 males and 883 females) completed the Horne–Östberg (HÖ) questionnaire for diurnal preference and provided a DNA sample. Overall HÖ scores were plotted against age. The 5% extremes and intermediates were selected for genotyping. Frequencies of the PER3 4‐ and 5‐repeat alleles were examined in separate age groups (18–29, 30–39, 40–49 and 50+ years of age). The 4‐repeat allele was significantly more frequent in evening types, and the 5‐repeat allele more frequent in morning types (Fisher's exact test, P = 0.016). Analysis in the four age groupings revealed that the strength of this association attenuated with age and was significant only in the youngest group (18–29 years). These results extend our previous finding of an association between the PER3 VNTR and diurnal preference. They also demonstrate that diurnal preference in young people is more closely associated with this polymorphism than it is in other age groups.
Stability of genetic influence on morningness–eveningness: a cross‐sectional examination of South Korean twins from preadolescence to young adulthood
Authors: HUR YOON‐MI
Published: February 2007

A cross‐sectional twin design was used to study the developmental nature of genetic and environmental influences on morningness–eveningness (M–E). A total of 977 South Korean twin pairs aged 9–23 years completed 13 items of a Korean version of the Composite Scale through the telephone interview. The total sample was split into three age groups: preadolescents, adolescents, and young adults. Twin correlations did not vary significantly with age, suggesting that genetic influences on M–E are stable throughout the developmental span. Results of model‐fitting analyses indicated that genetic and environmental factors explained, respectively, 45% and 55% of the variance in all three age groups. Environmental factors were primarily those factors that twins did not share as a consequence of their common rearing; family environmental factors in M–E were consistently near zero in all three age groups. The present study is the first to demonstrate genetic influences on M–E in preadolescent children as young as 9 years old. In spite of differences in culture and frequencies of genes between South Koreans and Caucasians, genetic and environmental influences on M–E found in the present sample were remarkably similar to those reported by previous studies on the basis of late adolescent and adult Caucasian twins.
The dynamics of neurobehavioural recovery following sleep loss
Authors: LAMOND NICOLE , JAY SARAH M. , DORRIAN JILLIAN , FERGUSON SALLY A. , JONES CHRISTOPHER , DAWSON DREW
Published: February 2007

Rate of recovery of daytime performance and sleepiness following moderate and severe sleep deprivation (SD) was examined when recovery opportunity was either augmented or restricted. Thirty healthy non‐smokers, aged 18–33 years, participated in one of three conditions: moderate SD with augmented (9‐h) recovery opportunities, moderate SD with restricted (6‐h) recovery opportunities, or severe SD with augmented recovery opportunities. Each participant attended the laboratory for 8–9 consecutive nights: an adaptation and baseline night (23:00–08:00 hours), one or two night(s) of wakefulness, and five consecutive recovery sleep opportunities (23:00–08:00 hours or 02:00–08:00 hours). On each experimental day, psychomotor vigilance performance (PVT) and subjective sleepiness (SSS) were assessed at two‐hourly intervals, and MSLTs were performed at 1000h. PSG data was collected for each sleep period. For all groups, PVT performance significantly deteriorated during the period of wakefulness, and sleepiness significantly increased. Significant differences were observed between the groups during the recovery phase. Following moderate SD, response speed, lapses and SSS returned to baseline after one 9‐h sleep opportunity, while sleep latencies required two 9‐h opportunities. When the recovery opportunity was restricted to six hours, neither PVT performance nor sleepiness recovered, but stabilised at below‐baseline levels. Following severe SD, sleepiness recovered after one (SSS) or two (physiological) 9‐h sleep opportunities, however PVT performance remained significantly below baseline for the entire recovery period. These results suggest that the mechanisms underlying the recovery process may be more complicated than previously thought, and that we may have underestimated the impact of sleep loss and/or the restorative value of subsequent sleep.
Maturation of the initial ventilatory response to hypoxia in sleeping infants
Authors: RICHARDSON HEIDI L. , PARSLOW PETER M. , WALKER ADRIAN M. , HARDING RICHARD , HORNE ROSEMARY S. C.
Published: February 2007

In infants most previous studies of the hypoxic ventilatory response (HVR) have been conducted only during quiet sleep (QS) and arousal responses have not been considered. Our aim was to quantify the maturation of the HVR in term infants during both active sleep (AS) and QS over the first 6 months of life. Daytime polysomnography was performed on 15 healthy term infants at 2–5 weeks, 2–3 and 5–6 months after birth and infants were challenged with hypoxia (15% O2, balance N2). Tests in AS always resulted in arousal; in QS tests infants either aroused or did not arouse. A biphasic HVR was observed in non arousing tests at all three ages studied. The fall in SpO2was more rapid in arousal tests at all three ages. At 2–5 weeks, in non‐arousing QS tests, there was a greater fall in respiratory frequency (f) despite a smaller fall in SpO2compared with 2–3 and 5–6 months. When infants aroused there was no difference in the HVR between sleep states or with postnatal age. However, when infants failed to arouse from QS, arterial desaturation was less in the younger infants despite a poorer HVR. We suggest that arousal in response to hypoxia, particularly in AS, is a vital survival mechanism throughout the first 6 months of life.
Daytime sleepiness, exercise, and physical function in older adults
Authors: CHASENS EILEEN R. , SEREIKA SUSAN M. , WEAVER TERRI E. , UMLAUF MARY GRACE
Published: February 2007

The purpose of this study was to describe the association between sleepiness, exercise, and physical function in older adults, testing the hypothesis that sleepiness predicts decreased exercise and impaired physical function in this population. We performed a secondary analysis of data from the National Sleep Foundation's Sleep in America Poll, comparing frequency of exercise and ability to perform functional tasks between sleepy and non‐sleepy subjects. Trained interviewers administered a scripted telephone survey. Participants (n = 1506) were community‐dwelling older Americans (55–84 years) randomly chosen from geographically representative households with listed telephone numbers. Sleepiness ‘so severe that it interferes with daytime activity’ was dichotomized as ‘daily/frequently’ or ‘never/rare’. Exercise frequency was scored 1–4 (‘less than once a week’ to ‘more than five times a week’). Responses to five questions (walk 0.5 mile, climb stairs, push/pull heavy object, stoop/crouch/or kneel, write, handle small objects), rated 1–5 (‘no difficulty’ to ‘unable to do’), were summed; a mean score of ≥2.5 was considered impaired physical function. Daytime sleepiness predicted low exercise frequency while controlling for age and body mass index (BMI) (OR = 1.40, 95% CI 1.031–1.897, P = 0.031). Frequent daytime sleepiness predicted impaired physical function (OR = 2.76, 95%CI = 0.237–0.553, P = 0.001) after controlling for age, BMI, income and number of co‐morbid conditions. The conclusion was that daytime sleepiness in older adults is associated with physical functional impairments and decreased exercise frequency. The findings suggest that sleepiness in older adults is not benign but has implications for continued physical decline and warrants attention.
In vivo immunization in combination with peg‐interferon for chronic hepatitis B virus infection
Authors: Sprengers D. , Van Der Molen R. G. , Binda R. , Kusters J. G. , De Man R. A. , Niesters H. G. M. , Schalm S. W. , Janssen H. L. A.
Published: February 2007

Summary.  Only in a minority of patients with chronic hepatitis B (CHB) will treatment with interferon (IFN)‐α or nucleoside analogues lead to sustained virological response. In vivo immunization (IVI) following virus suppression aims to optimize conditions for an effective immune response: following rapid and profound virus suppression by interferon–lamivudine combination therapy, lamivudine is withdrawn intermittently during continued interferon therapy. It is thought that withdrawal of lamivudine will lead to increased viral replication and increased antigen expression with subsequent immune stimulation. The aim of this prospective pilot study was to evaluate IVI as a therapeutic approach for CHB. Fourteen HBeAg‐positive CHB patients were treated for 42 weeks with a combination of pegylated interferon‐alpha 2b and lamivudine. After 12 weeks of combination therapy lamivudine was withdrawn intermittently for three consecutive periods of 4 weeks until it was permanently stopped on week 36. At the end of follow‐up (week 52) all patients had remained HBeAg positive and the median viral load was similar to baseline. During the initial 12 weeks of treatment, there was a reduction of both the hepatitis B virus (HBV)‐specific proliferation capacity of Th‐cells and the frequencies of IFNγ‐producing cells. During the lamivudine interruption‐cycle there was an inverse relation between the increase of HBV‐DNA, and the decrease in proliferation capacity and frequency of IFN‐γ‐producing cells. The intrahepatic fraction of CD8+ T‐cells increased during lamivudine withdrawal. In conclusion, IVI was able to transiently stimulate the HBV‐specific immune responsiveness of T‐cells, but the magnitude of the response was insufficient to cause a beneficial virological effect.
An hepatitis B virus surface antigen specific single chain of variable fragment derived from a natural immune antigen binding fragment phage display library is specifically internalized by HepG2.2.15 cells
Authors: Wen W.‐H. , Qin W.‐J. , Gao H. , Zhao J. , Jia L.‐T. , Liao Q.‐H. , Meng Y.‐L. , Jin B.‐Q. , Yao L.‐B. , Chen S.‐Y. , Yang A.‐G.
Published: February 2007

Summary.  Hepatitis B virus surface antigen (HBsAg), a specific antigen on the membrane of hepatitis B virus (HBV)‐infected cells, provides a perfect target for therapeutic drugs. In order to mediate successful targeted delivery of these therapies, it is essential to have antibodies that recognize HBsAg with high specificity and affinity. In this report, we constructed a natural immune antigen binding fragments (Fab) antibody phage display library against HBsAg and after three rounds of panning, five Fab fragments with significant HBsAg binding ability were selected and analysed. DNA sequencing revealed that all the light chains had the same sequence, while all the Fd genes exhibited different sequences. For further application, all of the Fab antibodies were reconstructed into single chain antibodies (scFvs) and expressed in Escherichia coli BL21 cells. Indirect enzyme‐linked immunosorbent assay analysis demonstrated that all five scFvs maintained a high affinity for HBsAg and could bind HBsAg on the membrane of HBV‐infected cells. Indirect fluorescent staining analysis revealed that one of the scFvs (scFv15) could be internalized into HBsAg‐positive HepG2.2.15 cells through clathrin‐mediated endocytosis pathway. The internalizing scFv15 antibody would have great potential for the targeted delivery of therapeutics to HBV‐infected cells.
Detecting shifts of transmission areas in avian blood parasites — a phylogenetic approach
Authors: HELLGREN OLOF , WALDENSTRÖM JONAS , PERÉZ‐TRIS JAVIER , SZÖLL ESZTER , SI Ö , HASSELQUIST DENNIS , KRIZANAUSKIENE ASTA , OTTOSSON ULF , BENSCH STAFFAN
Published: February 2007

We investigated the degree of geographical shifts of transmission areas of vector‐borne avian blood parasites (Plasmodium,HaemoproteusandLeucocytozoon) over ecological and evolutionary timescales. Of 259 different parasite lineages obtained from 5886 screened birds sampled in Europe and Africa, only two lineages were confirmed to have current transmission in resident bird species in both geographical areas. We used a phylogenetic approach to show that parasites belonging to the generaHaemoproteusandLeucocytozoonrarely change transmission area and that these parasites are restricted to one resident bird fauna over a long evolutionary time span and are not freely spread between the continents with the help of migratory birds. Lineages of the genusPlasmodiumseem more freely spread between the continents. We suggest that such a reduced transmission barrier ofPlasmodiumparasites is caused by their higher tendency to infect migratory bird species, which might facilitate shifting of transmission area. Although vector‐borne parasites of these genera apparently can shift between a tropical and a temperate transmission area and these areas are linked with an immense amount of annual bird migration, our data suggest that novel introductions of these parasites into resident bird faunas are rather rare evolutionary events.
Phylogeography of the rare Balkan endemic Martino's vole, Dinaromys bogdanovi, reveals strong differentiation within the western Balkan Peninsula
Authors: KRYSTUFEK BORIS , BUZAN ELENA V. , HUTCHINSON WILLIAM F. , HÄNFLING BERND
Published: February 2007

The spatial genetic structure of Martino's vole, a rare palaeoendemic species of the western Balkans, was investigated using DNA isolated from archived museum samples. The study was based on partial sequencing (555 bp) of the mitochondrial cytochrome b gene for 63 specimens from 20 different localities throughout the species’ range. Three highly divergent allopatric phylogenetic lineages (Northwestern, Central and Southeastern) were recognized among 47 haplotypes, suggesting three independent glacial differentiation centres within the western Balkans. The Northwestern lineage, which showed the highest divergence from all other samples (mean sequence divergence of 6.64% ± 1.10), comprised samples collected from northwest of the Neretva River in Croatia, western Bosnia and Herzegovina. The Central and Southeastern lineages were separated by an average sequence divergence of 2.95% ± 0.66 and were geographically divided by the Drim River (the Kosovo Basin in Serbia). Overall, haplotype diversity decreased from the Northwestern lineage to the Central and subsequently the Southeastern lineage, in a geographical pattern consistent with a stepping stone colonization. The observed distribution indicates a gradual southerly expansion with subsequent allopatry across the Neretva River and Drim River approximately 1 and 0.3 million years ago, respectively. Such a scenario is concordant with palaeontological evidence. Several highly divergent sublineages within the Northwestern and Central lineages showed no significant geographical structuring, suggesting secondary contact of allopatrically evolved lineages. We hypothesize that the topographical complexity of the Balkans promoted allopatry and isolation on a small geographical scale during interglacial periods, with secondary contact during glacial maxima. Furthermore, the three main lineages should be regarded as evolutionary significant units with important implications for conservation. Ecological data show that the Northwestern lineage in particular fulfils all criteria for a highly endangered, evolutionarily significant unit.
Introgression in the genusSalmovia allotriploids
Authors: CASTILLO A. G. F. , BEALL E. , MORAN P. , MARTINEZ J. L. , AYLLON F. , GARCIA‐VAZQUEZ E.
Published: February 2007

Hybridization between sympatric species is not uncommon in the wild. Wild allotriploids (individuals with two chromosome sets from a species + one chromosome set from another species) are generally the result of a backcross between interspecific hybrids that produce unreduced gametes and one of the parental species. In animals, allotriploids are commonly sterile, except for some vertebrate species complexes in which allotriploids reproduce by parthenogenesis, gynogenesis and/or hybridogenesis, producing generally clonal or hemiclonal gametes; nuclear DNA introgression between hybridizing species is considered to be extremely rare. Employing species‐specific molecular markers, we show genetic introgression between the chromosomally well‐differentiated salmonids Atlantic salmon (2n = 58) and brown trout (2n = 80) through spontaneous bisexual reproduction of allotriploids leading to salmon‐like offspring bearing some brown trout genes. Although introgression between theseSalmospecies can occur via allotriploids, we hypothesize that extinction of parental species can be discarded based on very low survival of allotriploid offspring.
Host islands within the California Northern Channel Islands create fine‐scale genetic structure in two sympatric species of the symbiotic ectomycorrhizal fungusRhizopogon
Authors: GRUBISHA LISA C. , BERGEMANN SARAH E. , BRUNS THOMAS D.
Published: February 2007

We have examined fine‐scale genetic structure of the symbiotic ectomycorrhizal fungiRhizopogon occidentalisandR. vulgarison two of the California Channel Islands using five and six microsatellite loci, respectively. BothRhizopogonspecies are sympatric on Santa Cruz and Santa Rosa Islands and are ectomycorrhizal with bishop pine (Pinus muricata) on both islands or Santa Rosa Island Torrey pine (P. torreyanassp.insularis) on Santa Rosa. The combination of disjunct pine host distributions and geographic barriers within and among the islands have created highly structuredRhizopogonpopulations over very short distances (8.5 km on Santa Cruz Island;FST = 0.258,FST = 0.056,R. occidentalisandR. vulgaris, respectively). Both species show similar patterns of genetic differentiation as a result of limited dispersal between host populations as revealed by a significant isolation by distance relationship (r = 0.69,P < 0.04;r = 0.93,P < 0.001,R. occidentalisandR. vulgaris, respectively) and Bayesian clustering analyses, and is most likely a function of the small foraging range of the few mammals that disperseRhizopogonon these islands and the enormous spore bank characteristic ofRhizopogonspecies.
Molecular function of WhiB4/Rv3681c of Mycobacterium tuberculosis H37Rv: a [4Fe−4S] cluster co‐ordinating protein disulphide reductase
Authors: Alam Md. Suhail , Garg Saurabh K. , Agrawal Pushpa
Published: February 2007

The genome sequence of Mycobacterium tuberculosis H37Rv revealed the presence of seven whiB‐like open reading frames. In spite of several genetic studies on whiB genes, the biochemical properties of WhiB proteins are poorly understood. All WhiB‐like proteins have four conserved cysteine residues, out of which two are present in a CXXC motif. We report for the first time the detailed biochemical and biophysical properties of M. tuberculosis WhiB4/Rv3681c and demonstrate the functional relevance of four conserved cysteines and the CXXC motif. UV‐visible absorption spectra of freshly purified mWhiB4 showed the presence of a [2Fe−2S] cluster, whereas the electron paramagnetic resonance (EPR) spectra of reconstituted protein showed the presence of a [4Fe−4S] cluster. The iron–sulphur cluster was redox sensitive but stably co‐ordinated to the protein even in the presence of high concentration of chaotropic agents. Despite primary sequence divergence from thioredoxin family proteins, the apo mWhiB4 has properties similar to thioredoxins and functions as a protein disulphide reductase, whereas holo mWhiB4 is enzymatically inactive. Apart from the cysteine thiol of CXXC motif the distantly placed thiol pair also contributes equally to the enzymatic activity of mWhiB4. A functional model of mWhiB4 in redox signaling during oxidative stress in M. tuberculosis has been presented.
Rapamycin‐mediated G1 arrest involves regulation of the Cdk inhibitor Sic1 in Saccharomyces cerevisiae
Authors: Zinzalla Vittoria , Graziola Michele , Mastriani Andrea , Vanoni Marco , Alberghina Lilia
Published: February 2007

The rapamycin‐sensitive (TOR) signalling pathway in Saccharomyces cerevisiae controls growth and cell proliferation in response to nutrient availability. Rapamycin treatment causes cells to arrest growth in G1 phase. The mechanism by which the inhibition of the TOR pathway regulates cell cycle progression is not completely understood. Here we show that rapamycin causes G1 arrest by a dual mechanism that comprises downregulation of the G1‐cyclins Cln1‐3 and upregulation of the Cdk inhibitor protein Sic1. The increase of Sic1 level is mostly independent of the downregulation of the G1 cyclins, being unaffected by ectopic CLN2 expression, but requires Sic1 phosphorylation of Thr173, because it is lost in cells expressing Sic1T173A. Rapamycin‐mediated Sic1 upregulation involves nuclear accumulation of a more stable, non‐ubiquitinated protein. Either SIC1 deletion or CLN3 overexpression results in non‐cell‐cycle‐specific arrest upon rapamycin treatment and makes cells sensitive to a sublethal dose of rapamycin and to nutrient starvation. In conclusion, our data indicate that Sic1 is involved in rapamycin‐induced G1 arrest and that deregulated entrance into S phase severely decreases the ability of a cell to cope with starvation conditions induced by nutrient depletion or which are mimicked by rapamycin treatment.
The molecular basis of selective promoter activation by the σS subunit of RNA polymerase
Authors: Typas Athanasios , Becker Gisela , Hengge Regine
Published: February 2007

Different environmental stimuli cause bacteria to exchange the sigma subunit in the RNA polymerase (RNAP) and, thereby, tune their gene expression according to the newly emerging needs. Sigma factors are usually thought to recognize clearly distinguishable promoter DNA determinants, and thereby activate distinct gene sets, known as their regulons. In this review, we illustrate how the principle sigma factor in stationary phase and in stressful conditions in Escherichia coli, σS (RpoS), can specifically target its large regulon in vivo, although it is known to recognize the same core promoter elements in vitro as the housekeeping sigma factor, σ70 (RpoD). Variable combinations of cis‐acting promoter features and trans‐acting protein factors determine whether a promoter is recognized by RNAP containing σS or σ70, or by both holoenzymes. How these promoter features impose σS selectivity is further discussed. Moreover, additional pathways allow σS to compete more efficiently than σ70 for limiting amounts of core RNAP (E) and thereby enhance EσS formation and effectiveness. Finally, these topics are discussed in the context of sigma factor evolution and the benefits a cell gains from retaining competing and closely related sigma factors with overlapping sets of target genes.
Sck1 activator coordinates glucose transport and glycolysis and is controlled by Rag8 casein kinase I in Kluyveromyces lactis
Authors: Neil Helen , Hnatova Martina , Wésolowski‐Louvel Micheline , Rycovska Adriana , Lemaire Marc
Published: February 2007

Casein kinases I (CKI) are ubiquitous in eukaryotic cells and are crucial factors for nutrient‐signalling pathways in yeasts. In Kluyveromyces lactis, the KlRgt1 repressor represses the expression of the glucose transporter RAG1 gene in absence of glucose, but in response to glucose availability, Rag8 CKI cooperates with the Rag4 glucose sensor to inactivate KlRgt1. The SCK1 gene, a rag8 mutation suppressor, encodes a bHLH activator required for maximal expression of the RAG1 and glycolytic genes in the presence of glucose. We investigated further the function of Sck1 and its relationship to Rag8. We demonstrated that Sck1 regulates the RAG1 and glycolytic genes by directly binding to their promoter. We also found that SCK1 gene expression was induced by glucose and repressed by KlRgt1. In addition, we showed that (i) Sck1 was phosphorylated in vivo, (ii) Sck1 was phosphorylated in vitro by Rag8, and (iii) Sck1 was rapidly degraded in a rag8 mutant. We therefore suggest that Sck1 coordinates glucose import and glycolysis in K. lactis and that Rag8 controls this transcription factor by transcriptional and post‐translational regulations.