bluuebunny/crossref_metadata_2025 huggingface dataset:
Monitoring red squirrelsSciurus vulgarisand grey squirrelsSciurus carolinensisin Britain
Authors: GURNELL J. , LURZ P. W. W. , SHIRLEY M. D. F. , CARTMEL S. , GARSON P. J. , MAGRIS L. , STEELE J.
Published: December 2004

1. In Britain, five indirect methods have been used to survey for the presence of redSciurus vulgarisand grey squirrelsS. carolinensisand to monitor population trends through time. These are: visual counts along line transects, the use of hair tubes, counts of dreys, cone line feeding transects in conifer forests and feeding signs on whole maize bait at feeding stations.

2. Drey counts and cone feeding transects cannot differentiate between red and grey squirrels and are not suitable for areas where both species may be present. Hair tubes require expertise and facilities to identify hairs to species, and the relationship between tube visits and animal density in different habitats is only known for red squirrels in Sitka sprucePicea sitchensisdominated plantations. Visual counts along line transects are the simplest method to do and require little equipment. However, in general, few squirrels are seen in a single count which leads to difficulties in estimating densities.

3. In this paper we present data from several studies carried out in Britain to illustrate the type of data that may be collected, and to evaluate their accuracy and precision with which they could detect population change. Hair tube lines and drey counts required the fewest number of samples to detect population change. When effort was also considered, visual transects and drey counts were more economical. However, none of the monitoring methods discussed is very precise and it may be best to monitor squirrels only in terms of relative changes in numbers or indices of numbers through time.

4. Our results for red and grey squirrels also illustrated that the number of samples required to detect population change is likely to differ according to the size of the survey area. Monitoring programmes should therefore be carefully planned in relation to spatial scale in order to be able to detect real population changes. Species‐specific, quantitative thresholds to determine the significance of detected declines may need to be established for threatened UK mammals and assessed in relation to what would constitute a significant decline and whether it requires management intervention.
An integrated monitoring programme for terrestrial mammals in Britain
Authors: HARRIS STEPHEN , YALDEN D. W.
Published: December 2004

We discuss how to monitor changes in the numbers of British terrestrial mammals, make specific recommendations for the most appropriate monitoring techniques for each species, and explain how these should be integrated into a co‐ordinated mammal monitoring programme.
IL‐16 expression in lymphocytes and microglia in HIV‐1 encephalitis
Authors: Zhao M.‐L. , Si Q. , Lee S. C.
Published: December 2004

IL‐16 is a natural ligand for the CD4 molecule and is known for its chemotactic and anti‐HIV‐1 activities. We determined IL‐16 expression in human brain tissue with HIV‐1 encephalitis by specific immunocytochemistry and showed that infiltrating lymphocytes and activated microglia express IL‐16. IL‐16 immunoreactivity was particularly pronounced in microglial nodules. In vitro, human foetal microglia and not astrocytes produce IL‐16, and HIV‐1 infection up‐regulates microglial IL‐16 release in a Nef‐dependent manner. These results support the notion that, in the brain, IL‐16 is a macrophage‐lineage specific modulator of the inflammatory response and HIV‐1 expression. Recruitment of IL‐16+ T cells and microglia/macrophages may represent an innate response to HIV‐1 infection in the central nervous system that counterbalances viral stimulatory factors.
Endogenous Growth: Estimating the Romer Model for the US and Germany*
Authors: Gong Gang , Greiner Alfred , Semmler Willi
Published: December 2004

By contrasting endogenous growth models with facts, one is frequently confronted with the prediction that levels of economic variables, such as R&D expenditures, imply lasting effects on the growth rate of an economy. As stylized facts show, the research intensity in most advanced countries has dramatically increased, mostly more than the GDP. Yet, the growth rates have roughly remained constant or even declined. In this paper we modify the Romer endogenous growth model and test our variant of the model using time series data. We estimate the market version both for the US and Germany for the time period January 1962 to April 1996. Our results demonstrate that the model is compatible with the time series for aggregate data in those countries. All parameters fall into a reasonable range.
Tests for a Break in Level when the Order of Integration is Unknown*
Authors: Harvey David I. , Leybourne Stephen J. , Newbold Paul
Published: December 2004

In this paper, we consider tests for a break in the level of a series at an unknown point in time. It is often the case that uncertainty exists concerning the order of integration of the series; consequently, we focus on tests that are applicable when the order of integration is not known. The size and power of existing tests are analysed, and a modification to one of the established sets of tests is proposed which offers improved performance in certain circumstances.
Nucleotide diversity in populations of balitorid cave fishes from Thailand
Authors: Borowsky R. L. , Vidthayanon C.
Published: December 2004

Genetic variabilities in four cave and eight surface species of balitorid freshwater fishes from Thailand were assessed using random amplified polymorphic DNA (RAPD). Cave species have consistently lower RAPD variation than surface species and it is hypothesized that this difference is a function of reduced population size in cave fishes. Indices of nucleotide diversity (π) were calculated from the RAPD data and are four to five times higher for the surface species than the cave species: 6.4 × 10−3 vs. 1.4 × 10−3. The π‐values for cave fishes are significantly lower than those for surface balitorids and those measured in other species using RAPD/amplified fragment length polymorphism data.
Evaluation of visible implant elastomer for individual marking of small perch and common bully
Authors: Goldsmith R. J. , Closs G. P. , Steen H.
Published: December 2004

Visible implant elastomer (VIE) was evaluated as a method for individual marking of small perch Perca fluviatilis and common bully Gobiomorphus cotidianus to use in capture–recapture studies. Growth, survival and mark retention was measured in 25 VIE marked and 15 unmarked fish of each species during a 125 day laboratory experiment. Marking had no effect on growth or survival of either species and mark retention in perch was 100%. Common bully mark retention was high for the initial 30 days but decreased to 72% by the end of the experiment. VIE marking provided an excellent method for individual identification of small perch over periods of at least 125 days, but improvements to common bully mark retention are necessary if VIE is to be used in capture–recapture studies >30 days.
Development and validation of methods for measuring multiple biochemical indices of condition in juvenile fishes
Authors: Weber L. P. , Higgins P. S. , Carlson R. I. , Janz D. M.
Published: December 2004

The investigation established and validated methods to measure multiple biochemical indices of condition (whole body total lipids, whole body triglycerides, muscle RNA : DNA ratio and muscle protein) simultaneously in the same individual juvenile fish. It also provided examples of their application using a species comparison (salmonids and cyprinids) of the degree of change in these indices after food deprivation. The results showed that juvenile rainbow trout Oncorhynchus mykiss were much more susceptible to a decline in all biochemical indices of condition than juvenile fathead minnows Pimephales promelas upon food deprivation. The combination of these techniques can be used to accurately assess condition and growth potential of individuals from wild fish populations.
Piscivory and prey selection of four predator species in a whitefish dominated subarctic lake
Authors: Kahilainen K. , Lehtonen H.
Published: December 2004

According to logistic regressions derived for pikeEsox luciusand burbotLota lota, the probability of ingesting fishes in Lake Muddusjärvi, northern Finland, was 50% at 19·3 and 22·1 cmLT, whereas Arctic charrSalvelinus alpinusand brown troutSalmo truttashifted to piscivory at the lengths of 25·7 and 26·4 cmLT. The specialist piscivores, pike and burbot, consumed more prey species and took a wider range of prey sizes than Arctic charr and brown trout. The prey length for all predators increased in relationship to predator length. WhitefishCoregonus lavaretuswas the dominant prey species in the lake and in the diet of all the piscivorous species. The whitefish population was divided into three forms, of which the slow‐growing, and the most numerous densely rakered whitefish form (DR), was selected by all predator species. This form also had the smallest average size and widest habitat range, utilizing both pelagic and epibenthic habitats. Two sparsely rakered whitefish forms (LSR and SSR) occupied only epibenthic habitats and had lower relative densities than DR. These forms, LSR and SSR, had a minor importance in the diet of predator species.
Condition of Barbus sclateri from semi‐arid aquatic systems: effects of habitat quality disturbances
Authors: Oliva‐Paterna F. J. , Vila‐Gispert A. , Torralva M.
Published: December 2004

This study investigated the relationships between fish condition and environmental variables in Barbus sclateri from semi‐arid freshwater ecosystems in the south‐eastern Iberian Peninsula. Two main habitats were studied: semi‐arid streams characterized by strong seasonal fluctuations in flow level (droughts and floods) and reservoirs (artificial ecosystems characterised by waters of high conductivity). The mass–length relationships were used to test differences in fish condition between nine stream populations and five reservoir populations of B. sclateri from the Segura River basin. The relationships between seven ecosystem variables (conductivity, oxygen concentration, water temperature, pH, seasonal water flow, submerged vegetation and sub‐basin location) and fish condition were analysed. The ecological variables that accounted for most of the variation in fish condition were seasonal water fluctuation and water conductivity. The condition of B. sclateri populations may be a good indicator of fish habitat quality in Mediterranean semi‐arid freshwater ecosystems and should be considered when such populations are subjected to sports fishing regulations, recovery plans or any other management programme.
Interleukin‐1β induces matrix metalloproteinase‐1 expression in cultured human gingival fibroblasts: role of cyclooxygenase‐2 and prostaglandin E2
Authors: Sakaki H , Matsumiya T , Kusumi A , Imaizumi T , Satoh H , Yoshida H , Satoh K , Kimura H
Published: December 2004

Objective:  Matrix metalloproteinases (MMPs) degrade extracellular matrices and are responsible for excessive connective tissue breakdown in inflammatory disorders. We investigated the mechanism of MMP‐1 expression in human gingival fibroblasts in response to the stimulation with interleukin‐1β (IL‐1β), and the role of inducible‐type cyclooxygenase‐2 (COX‐2) and prostaglandin E2 (PGE2) in the regulation of MMP‐1 expression.

Materials and methods:  We stimulated cultured human gingival fibroblasts with r(h)IL‐1β, and examined the expression of MMP‐1 mRNA and protein by quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay. The effect of indomethacin, dexamethasone, or cycloheximide (CHX) on the IL‐1β‐induced expression of MMP‐1 was examined. The expression of MMP‐1 in gingival fibroblasts stimulated with PGE2 was also examined.

Results:  IL‐1β stimulated the expressions of mRNA and protein for MMP‐1, in cultured fibroblasts, in time‐ and concentration‐dependent manners. Pretreatment of the cells with indomethacin or dexamethasone inhibited the IL‐1β‐induced MMP‐1 expression. CHX, a protein synthesis inhibitor, also suppressed the MMP‐1 expression. IL‐1β also induced COX‐2 expression in gingival fibroblasts, and PGE2, a major COX‐2 product, was found to enhance MMP‐1 expression.

Conclusion:  The IL‐1β‐induced MMP‐1 expression in gingival fibroblasts may be mediated, at least in part, by COX‐2 and its product PGE2.
Turnip vein‐clearing virus,from pathogen to host expression profile
Authors: Melcher Ulrich
Published: December 2004

Taxonomy:Turnip vein‐clearing virus(TVCV) is a member of subgroup 3 of theTobamovirusgenus and is thus a member of the alphavirus‐like supergroup of positive sense RNA‐containing viruses.

Physical properties:Virions, typical of tobamoviruses, are rod‐shaped and consist of a single species of four‐helix bundle capsid proteins of 17 kDa helically arranged around a 6.3 knt RNA which accounts for 5% of the virion mass. Virions are stable for years.

Hosts:Members of the crucifer family are excellent hosts. Particularly noteworthy is that hosts include the model plant for molecular genetics,Arabidopsis thaliana.No non‐mechanical vectors of transmission are known.
Real‐time analysis ofPolymyxa betaeGST expression in infected sugar beet
Authors: Kingsnorth Crawford S. , Kingsnorth Amanda J. , Lyons Paul A. , Chwarszczynska Daphne M. , Asher Michael J. C.
Published: December 2004

We have tested and developed protocols for both sequence‐independent and hybridization probe real‐time PCR for the detection ofPolymyxa betaeglutathione‐S‐transferase transcripts in infected sugar beet roots. When using the test onP. betae‐free plants, no signal above the level of the non‐template control was observed. Real‐time PCR analysis of both serially diluted zoospore suspensions and infected root material demonstrated a close relationship between the threshold cycle and the amount ofP. betae. Hybridization probe real‐time analysis of infected plants sampled sequentially over 20 days from sowing showed that the levels of the transcript rose steadily after initial infection to a peak and then declined. Comparative time‐course analyses of infection in susceptible plants and a resistant wildBetaspecies indicated that, whilst transcript levels in susceptible plants showed a continuing upward trend, in the resistant species they were detectable only at an extremely low level.
The nutrient supply of pathogenic fungi; a fertile field for study
Authors: Solomon Peter S. , Tan Kar‐Chun , Oliver Richard P.
Published: December 2004

Phytopathogenic fungi must feed on their hosts to propagate and cause disease. Their ability to access the rich nutrient supply offered by living plants is one of the most obvious properties that distinguish pathogens from saprophytes. Successful invasion by pathogens depends as much on their ability to utilize the available nutrient sources offered by plants as on their ability to penetrate plants and evade defensive mechanisms. Here, we review current knowledge on the nature of the nutrient supplies utilized by pathogens during infection.

The available evidence is rudimentary in most cases. There is much evidence to suggest that fungal metabolism can be divided into at least two phases. The first is based on lipolysis and occurs during germination and penetration of the host. The second phase uses glycolysis and predominates during the invasion of host tissue. We also propose, mainly on theoretical grounds, that a third phase of nutrition occurs late in infection during which new spores are produced.

Contrary to early assumptions, the nitrogen sources available to some pathogens appear to be abundant. The idea that nitrogen starvation is a cue that controls fungal gene expression during infection may need to be reassessed. Very little is known about the micronutrient (Fe, S, P) or vitamin supply. The knowledge gained from this research may enable the design of new antifungal strategies targeting potential weaknesses in fungal metabolism and will also impact on agronomic practices.
Variable leucine‐rich repeats of tomato disease resistance genes Cf‐2 and Cf‐5 determine specificity
Authors: Seear Paul J. , Dixon Mark S.
Published: December 2004

The tomato Cf‐2 and Cf‐5 genes confer race specific resistance to infection by the leaf mould pathogen Cladosporium fulvum. The encoded proteins induce a defence response upon recognition of the fungal Avr2 and Avr5 determinants, respectively. Each resistance protein is comprised largely of leucine‐rich repeats (LRRs) and the specificity of recognition is thought to occur through a particular domain. We have investigated this further using domain swaps between Cf‐2 and Cf‐5. Engineered chimeric genes containing portions of Cf‐2 and Cf‐5 were expressed and shown to be functional. The results clearly show that the specificity for the particular avirulence determinant is restricted to a region of each gene that encodes a subset of LRRs containing the highest level of intergenic variability. In addition, two non‐functional mutants of Cf‐5 were characterized and their significance discussed.
Quinoxyfen perturbs signal transduction in barley powdery mildew (Blumeria graminis f.sp. hordei)
Authors: Wheeler Ian E. , Hollomon Derek W. , Gustafson Gary , Mitchell Jon C. , Longhurst Chris , Zhang Ziguo , Gurr Sarah J.
Published: December 2004

Quinoxyfen is a protectant fungicide which controls powdery mildew diseases by interfering with germination and/or appressorium formation. Mutants of barley powdery mildew, Blumeria graminis f.sp. hordei, which are resistant to quinoxyfen produce fewer conidia, which germinate and form appressoria more promiscuously than do the prolific numbers of wild‐type spores. This suggests that resistance bypasses host recognition signals. RT‐PCR profiles of signal transduction genes, recorded during wild‐type germling morphogenesis, reveals that quinoxyfen alters the accumulation of Protein Kinase C (pkc), pkc‐like and catalytic subunit of Protein Kinase A (cpka) transcripts. Differential display‐reverse transcription PCR identified a gene transcript in wild‐type conidia that was absent, or much less abundant, in conidia from quinoxyfen‐resistant mutants. This mRNA was not detectable 24 h after wild‐type conidia were inoculated on to barley. It encodes a GTPase activating protein (GAP), which may interact with a small molecular weight Ras‐type GTP binding protein. In the presence of quinoxyfen, the gap mRNA remains throughout germling morphogenesis. The involvement of GAP in resistance suggests that quinoxyfen inhibits mildew infection by disrupting early cell signalling events.
Genetic and forma specialis diversity in Blumeria graminis of cereals and its implications for host‐pathogen co‐evolution
Authors: Wyand Rebecca A. , Brown James K. M.
Published: December 2004

The grass powdery mildew fungus, Blumeria graminis is classified into eight formae speciales (ff.spp.) based on strict host specialization. However, evidence suggests that host ranges extend to more than one genus and are particularly diverse among samples from the Middle East, the proposed centre of origin and diversification of crop plants. This study investigated whether geographical origin, host species or both determine the genetic variation in B. graminis that is found in cereals, sampled from Europe, Asia and North America, and whether there is any evidence for co‐evolution between pathogen and host. Phylogenetic analysis of nucleotide sequence variation within the ribosomal DNA Internal Transcribed Spacer (ITS) regions and the β‐tubulin (tub2) gene gives rise to two dendrograms with different topologies. In both trees, isolates of B. graminis from cultivated cereals are grouped according to their principal host genus. This grouping was supported by amplified fragment length polymorphism (AFLP) analysis and cross‐infectivity tests. However, there was no evidence of co‐evolution. There was far greater divergence between ff.spp. in tub2 sequences than ITS regions and a faster rate of mutation of tub2, especially in the third base position of exons. It is proposed that variation in the rDNA‐ITS regions is constrained either by their functional role in the processing of rDNA precursor molecules or by concerted evolution, hence limiting their use in phylogenetic studies. AFLP data suggests an overall lack of correlation between geographical and genetic distances. This may be related to the long distance dispersal exhibited by B. graminis.
The Prognostic Significance of Subsyndromal Delirium in Elderly Medical Inpatients
Authors: Cole Martin , McCusker Jane , Dendukuri Nandini , Han Ling
Published: December 2004

OBJECTIVES: To determine the prognostic significance of subsyndromal delirium (SSD) presentations.

DESIGN: Cohort study.

SETTING: University‐affiliated primary acute care hospital.

PARTICIPANTS: One hundred sixty‐four elderly medical inpatients who did not meet Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM‐III‐R) criteria for delirium during the first week after admission were classified into three mutually exclusive groups. The first group, prevalent SSD, included those who had two or more of four core symptoms of delirium (clouding of consciousness, inattention, disorientation, perceptual disturbances) at admission. The second group, incident SSD, included those who did not meet criteria for prevalent SSD but displayed one or more new core symptoms during the week after admission. The third group had no prevalent or incident SSD. The three groups were followed up at 2, 6, and 12 months.

MEASUREMENTS: Outcomes (length of stay, symptoms of delirium (Delirium index), cognitive (Mini‐Mental State Examination) and functional status (instrumental activities of daily living), and mortality) were compared using univariate techniques and multivariate regression models that adjusted for age, sex, marital status, living arrangements before admission, comorbidity, clinical and physiological severity of illness, and dementia status and severity.

RESULTS: Patients with prevalent SSD had longer acute care hospital stay, increased postdischarge mortality, more symptoms of delirium, and a lower cognitive and functional level at follow‐up than patients with no SSD. Most of the findings for incident SSD were similar but not statistically significant. Patients with prevalent or incident SSD had risk factors for DSM‐defined delirium.

CONCLUSION: SSD in elderly medical inpatients appears to be a clinically important syndrome that falls on a continuum between no symptoms and DSM‐defined delirium.
Self‐Reported Disability and Its Association with Performance‐Based Limitation in Elderly Men: A Comparison of Three European Countries
Authors: Van Den Brink Carolien L. , Tijhuis Marja , Kalmijn Sandra , Klazinga Niek S. , Nissinen Aulikki , Giampaoli Simona , Kivinen Paula , Kromhout Daan , Van Den Bos Geertrudis A.M.
Published: December 2004

OBJECTIVES: To compare self‐reported disability and performance‐based limitation and their association in elderly men from three European countries.

DESIGN: Cross‐sectional data from a cohort study collected around 1990.

SETTING: Three cohorts from Finland, the Netherlands, and Italy.

PARTICIPANTS: One thousand one hundred sixty‐one men aged 70 and older.

MEASUREMENTS: Disability and functional limitation were measured in a standardized way in three countries. Self‐reported disability was estimated by questionnaire, assessing three domains of activities of daily living: instrumental activities of daily living, mobility, and activities of daily living (score 0–3). Functional limitation was measured by performance tests (score 0–16), with 0 indicated the healthiest score.

RESULTS: Self‐reported disability and performance‐based limitation scores differed between countries. Mean self‐reported disability score was worse in Italy (0.72) and the Netherlands (0.70) than in Finland (0.54). Italian men scored worst on the performance‐based tests (mean 4.80 vs 4.04 for Finland and 3.74 for the Netherlands). Differences in self‐reported disability remained after adjusting for performance scores: Dutch men reported more disabilities (odds ratio (OR) = 1.66, 95% confidence interval (CI) = 1.23–2.25) than men in Finland (reference group) and Italy (OR = 1.08, 95% CI = 0.77–1.53). Self‐reported disability was positively associated with performance‐based score (OR = 1.28, 95% CI = 1.21–1.35) and did not differ between countries.

CONCLUSION: Cross‐cultural variation was noted in self‐reported disability adjusted for performance score. These differences may be due to sociocultural and physical environmental factors. Self‐reported disability was consistently associated with performance‐based limitation in Finland, the Netherlands, and Italy.
Hypertension in Older Urban Native‐American Primary Care Patients
Authors: Rhoades Dorothy A. , Buchwald Dedra
Published: December 2004

OBJECTIVES: To examine hypertension and its management in a population of older urban American Indians and Alaska Natives (AI/ANs).

DESIGN: Retrospective cohort study using medical record review.

SETTING: Urban health clinic serving predominantly AI/ANs in the Pacific Northwest.

PARTICIPANTS: Five hundred twenty‐four AI/ANs aged 50 and older seen between 1994 and 1995.

MEASUREMENTS: Frequency of diagnosed hypertension, undiagnosed hypertension, comorbid conditions, hypertension treatment, control, and quality of care.

RESULTS: The prevalence of diagnosed hypertension was 38%, and the prevalence of possible undiagnosed hypertension was 23%. Patients with diagnosed hypertension were more likely to be obese (age‐adjusted odds ratio (OR) = 3.5), have diabetes mellitus (DM) (OR = 2.2), depression (OR = 1.7), heart disease (OR = 3.8), or renal disease (OR = 5.6) than patients without hypertension. Undiagnosed hypertension was inversely associated with number of health problems (OR = 0.8). Eighty‐one percent of diagnosed patients were treated pharmacologically, but no factors associated with nontreatment were identified. Diuretic and beta‐blocker usage was low. Patients with DM used angiotensin‐converting enzyme inhibitors more frequently than patients without DM (OR = 2.4). Blood pressure was well controlled in 37%, with men being less well controlled than women (OR = 0.5). Serum cholesterol, creatinine, and retinal screening were performed more often than urinalyses or electrocardiograms. Lifestyle‐modification counseling was uncommon. Number of health problems was the most common factor associated with screening tests for end‐organ disease.

CONCLUSION: Few studies have examined the care of older urban AI/ANs. Improvements are needed in adherence to recommendations for the detection, management, and monitoring of hypertension and its complications in older urban AI/ANs.
The Association Between Time Since Last Meal and Blood Pressure in Older Adults: The Cardiovascular Health Study
Authors: Smith Nicholas L. , Psaty Bruce M. , Rutan Gale H. , Lumley Thomas , Yanez David , Chaves Paulo H. M. , Kronmal Richard A.
Published: December 2004

OBJECTIVES: To demonstrate a postprandial hypotensive (PPH) phenomenon in older adults.

DESIGN: Observational, prospective cohort study composed of baseline and nine follow‐up visits.

SETTING: Cardiovascular Health Study, an epidemiological study of risk factors for cardiovascular disease in older adults.

PARTICIPANTS: Five thousand eight hundred eighty‐eight community‐dwelling adults aged 65 and older.

MEASUREMENTS: Blood pressure and time since last meal were recorded synchronously at baseline and at follow‐up clinic visits. Generalized estimating equations were used to estimate associations between time since last meal and blood pressure and to adjust variance estimates to account for repeated blood pressure measures within subjects across fasting times.

RESULTS: Mean systolic and diastolic blood pressures were lower in the first hour after the last meal and were progressively higher through the fourth hour after the last meal than blood pressures measured immediately after the last meal (0 hour: 133.7/68.8 mmHg; 1st hour: 130.1/66.6 mmHg; 4th hour: 136.5/71.1 mmHg). Changes were significant for systolic and diastolic measures (P < .001 for both). Exploratory analyses suggested that the systolic PPH association was more pronounced in women. Little evidence was found that the degree of systolic or diastolic PPH varied by age, race, prevalent cardiovascular disease, heart rate, ejection fraction, treated hypertension or diabetes mellitus, or body mass index.

CONCLUSION: These data support previous observations that there is a significant drop in blood pressure within 1 hour after a meal in older adults. Time since last meal may be an important factor to consider when measuring blood pressure in older adults, and perhaps national standards need to be set.
Reducing Fear of Falling in Seniors Through Education and Activity Programs: A Randomized Trial
Authors: Brouwer Brenda J. , Walker Cathy , Rydahl Sarah J. , Culham Elsie G.
Published: December 2004

OBJECTIVES: To determine the relative effect of education and activity programs on fear of falling, balance, strength, and health status.

DESIGN: A randomized intervention trial with two groups (education and activity); evaluators were blind to group allocation.

SETTING: Motor performance laboratory at Queen's University.

PARTICIPANTS: Thirty‐eight community‐dwelling seniors who reported a fear of falling and activity restriction but were free of neurological and mobility‐limiting orthopedic conditions.

INTERVENTIONS: Programs designed to reduce fear of falling were delivered weekly to groups of three to five seniors for 8 weeks, each session lasting 1 hour. The activity program included low‐resistance exercises and weight‐shifting activities. Education focused on identifying and reducing risk factors for falls.

MEASUREMENTS: Balance confidence, activity level, limits of stability (LOS), isokinetic strength, and health status were measured twice preintervention (baseline), postintervention, and 6 weeks later.

RESULTS: Both programs reduced fear of falling (P < .006) as ascertained from the balance confidence scores. Differential effects were observed in LOS (P < .05); activity improved balance, whereas education led to modest declines. Gains in perception of health status were limited to physical health for the activity group and mental health for the education group. Benefits were generally sustained at follow‐up.

CONCLUSION: Improved balance confidence is not intervention‐specific, but associated changes in physical ability and health status are a function of the composition of the intervention program.
Is a Fall Just a Fall: Correlates of Falling in Healthy Older Persons. The Health, Aging and Body Composition Study
Authors: De Rekeneire Nathalie , Visser Marjolein , Peila Rita , Nevitt Michael C. , Cauley Jane A. , Tylavsky Frances A. , Simonsick Eleanor M. , Harris Tamara B.
Published: December 2004

OBJECTIVES: To identify factors associated with falling in well‐functioning older people.

DESIGN: Cross‐sectional analyses of report of falls over the past 12 months using baseline data from the Health, Aging and Body Composition Study.

SETTING: Clinic examinations in Pittsburgh, Pennsylvania, or Memphis, Tennessee.

PARTICIPANTS: Three thousand seventy‐five high‐functioning black and white elderly aged 70 to 79 living in the community.

MEASUREMENTS: Physical function assessed using self‐report and performance measures. Health status indicators included diseases, medication use, and body composition measures.

RESULTS: Almost one‐quarter (24.1%) of women and 18.3% of men reported at least one fall within the year before the baseline examination. Fallers were more likely to be female; white; report more chronic diseases and medications; and have lower leg strength, poorer balance, slower 400‐meter walk time, and lower muscle mass. In men, multivariate logistic regression models showed white race (adjusted odds ratio (OR) = 1.4, 95% confidence interval (CI) = 1.2–1.6), slower 6‐meter walk speed (OR = 1.1, 95% CI = 1.0–1.3), poor standing balance (OR = 1.2, 95% CI = 1.0–1.4), inability to do 5 chair stands (OR = 1.7, 95% CI = 1.3–1.9), report of urinary incontinence (UI) (OR = 1.5, 95% CI = 1.1–2.0), and mid‐quintile of leg muscle strength (OR = 0.6, 95% CI = 0.4–0.9) to be independently associated with report of falling. In women, benzodiazepine use (OR = 1.6, 95% CI = 1.0–2.6), UI (OR = 1.5, 95% CI = 1.2–1.9), and reported difficulty in rising from a chair (OR = 1.4, 95% CI = 1.2–1.6) were associated with past falls.

CONCLUSION: Falls history needs to be screened in healthier older adults. Even for well‐functioning older persons, specific correlates of falling can be identified to define those at risk.
Role of CD4+ T helper 2‐type cells in cutaneous inflammatory responses induced by fluorescein isothiocyanate
Authors: Dearman R. J. , Kimber I.
Published: December 2004

Owing to its skin‐sensitizing and fluorochromatic properties, fluorescein isothiocyanate (FITC) is employed frequently as an experimental hapten in mechanistic studies of contact allergy, particularly in the context of the role of migration and activation of Langerhans' cells. In this study we demonstrated that topical exposure of mice to FITC results in the selective development of activated lymph node cells (LNC) expressing a preferential type 2 cytokine‐secretion profile, with high levels of interleukin (IL)‐4 and IL‐10, but low levels of interferon‐γ (IFN‐γ). Negative selection (complement depletion) identified CD4+ T helper (Th)2‐type cells as the primary source in activated LNC of the type 2 cytokines IL‐4 and IL‐10, whereas the low levels of IFN‐γ produced were derived exclusively from CD8+ T cytotoxic (Tc) 1‐type cells. A biphasic pattern of cutaneous inflammatory reactions was elicited by exposure to FITC, the early phase of which could be transferred passively with serum (presumably immunoglobulin E [IgE] antibody), whereas adoptive transfer experiments demonstrated that Th2‐type CD4+ cells were responsible for the delayed‐type component of the dermal hypersensitivity reaction. In contrast with contact allergic reactions induced by other sensitizing haptens, which are considered to be largely Th1/Tc1‐mediated immune processes regulated by Th2‐type cells, these results suggest therefore that the skin lesions provoked in mice by FITC are primarily a result of the activation of Th2‐type cells.
Anti‐T‐cell humoral and cellular responses in healthy BALB/c mice following immunization with ovalbumin or ovalbumin‐specific T cells
Authors: Zhang Xiao‐Yu , Liu Xiang‐Guo , Wang Wei , Wang Wen‐Chao , Gao Xiao‐Ming
Published: December 2004

It is known that T‐cell vaccination (TCV) elicits cellular immune responses against the immunizing T cells in vivo. However, it is still unclear whether similar anti‐T‐cell responses are also induced in individuals responding to foreign antigen (Ag) challenge. This study was undertaken to characterize and compare anti‐T‐cell cellular and humoral responses of BALB/c mice after ovalbumin (OVA) immunization or TCV. Splenocytes from OVA‐primed BALB/c mice proliferated in response to stimulation with a syngeneic OVA‐specific T‐cell clone, OVA‐T3, and secreted interferon‐γ (IFN‐γ) but not interleukin‐4 (IL‐4). Cytotoxic T‐lymphocyte (CTL) activity against the T‐cell clone was also observed. Serum samples from these animals discriminated between activated and resting murine T cells, as determined by indirect immunofluorescence staining. Vaccination of BALB/c mice with OVA‐T3 cells induced similar, but stronger, cellular and humoral responses. TCV‐induced antibodies were not only able to distinguish between activated and resting syngeneic T cells but also positively stained allogeneic T cells from BXSB mice. Furthermore, TCV resulted in hyporesponsiveness of BALB/c mice to subsequent Ag challenge, and antisera from the immunized animals inhibited T‐cell proliferation in vitro. Our data suggest that anti‐T‐cell antibodies, and CD4+ and CD8+ regulatory T lymphocytes may form a complex and co‐ordinated regulatory network that plays an important role in regulating the adaptive immune responses in vivo. Implications of this observation for our understanding of the immunoregulation and peripheral tolerance are discussed.
Overexpressed nuclear factor‐κB can participate in endogenous C‐reactive protein induction, and enhances the effects of C/EBPβ and signal transducer and activator of transcription‐3
Authors: Agrawal Alok , Cha‐Molstad Hyunjoo , Samols David , Kushner Irving
Published: December 2004

C‐reactive protein (CRP), the prototypical human acute phase protein, is produced primarily by hepatocytes. Its expression is modestly induced by interleukin (IL)‐6 in Hep3B cells while IL‐1, which alone has no effect, synergistically enhances the effects of IL‐6. In previous studies of the proximal CRP promoter, we found that signal transducer and activator of transcription‐3 (STAT3) and C/EBPβ ‐mediated IL‐6‐induced transcription and that Rel p50 acted synergistically with C/EBPβ, in the absence of p65, to enhance CRP transcription. Neither a requirement nor a binding site for the classic nuclear factor (NF)‐κB heterodimer p50/p65 were found. The current studies were undertaken to determine whether similar novel transcription factor interactions might regulate the endogenous CRP gene. Transiently overexpressed p50 or p65 induced CRP mRNA accumulation in Hep3B cells. The heterodimer p50/p65 was markedly more effective than p50 or p65 homodimers. Co‐overexpression of p50 or p65 with C/EBPβ or STAT3 synergistically enhanced CRP expression. Maximal expression was observed with overexpression of all four transcription factors; comparable effects were observed with IL‐1β treatment of cells overexpressing STAT3 + C/EBPβ. Data from the Human Genome Project revealed 13 potential κB sites in the first 4000 bases of the CRP promoter, only one of which, centred at −2652, bound nuclear p50/p65 heterodimer activated by IL‐1β. Our findings indicate that classical NF‐κB activation can participate in endogenous CRP induction, and that activated NF‐κB may synergistically enhance the effects of C/EBPβ and STAT3. They raise the possibility, not as yet established, that NF‐κB activation may be responsible for the synergistic effect of IL‐1β on IL‐6‐induced CRP expression.
Antibody response to influenza infection of mice: different patterns for glycoprotein and nucleocapsid antigens
Authors: Sealy Robert , Surman Sherri , Hurwitz Julia L. , Coleclough Christopher
Published: December 2004

Our previous studies of C57BL/6 mice intranasally infected with influenza virus (A/PR8) revealed a spike of virus‐specific immunoglobulin A (IgA)‐secreting antibody‐forming cells (AFC) in the mediastinal lymph node (MLN) 7 days post‐infection. Here we show that these AFC are directed only against viral glycoprotein, and not nucleocapsid antigens. The early IgA spike associates with a decline in glycoprotein‐specific AFC during week 2 post‐infection. In contrast to the glycoprotein‐specific AFC, nucleocapsid‐specific, IgA‐secreting AFC develop gradually in the MLN and persist for more than 3 weeks post‐infection. As peripheral lymph node reactions wane, the nucleocapsid‐specific AFC appear as long‐sustained populations in the bone marrow. Microanatomical examination of the respiratory tract in infected mice shows foci of infection established in the lung 2 days post‐infection, from which virus spreads to infect the entire lining of the trachea by day 3. At this time, viral haemagglutinin can be seen within the MLN, probably on projections from infected dendritic cells. This feature disappears within a day, though viral antigen expression continues to spread throughout the respiratory tract. Total IgA‐ and IgG‐secreting AFC appear histologically in large numbers during the first week post‐infection, significantly preceding the appearance of germinal centres (revealed by peanut agglutinin staining in week 2). To explain these results, we suggest that the initial immunogenic encounter of B cells with viral antigens occurs about 3 days post‐infection in the MLN, with antigens transported by dendritic cells from airway mucosa, the only site of viral replication. Viral glycoproteins expressed as integral membrane components on the surface of infected dendritic cells [probably in the absence of cognate T helper (Th) cells] promote members of expanding relevant B‐cell clones to undergo an IgA switch and terminal local plasmacytoid differentiation. Anti‐glycoprotein specificities are thus selectively depleted from progeny of activated B‐cell clones which are channelled to participate in germinal centre formation (perhaps by cognate T helper cells when they become sufficiently frequent). One product of the germinal centre reaction is the long‐sustained, bone marrow‐resident population, which is accordingly rich in anti‐nucleoprotein, but not anti‐glycoprotein specificities. Of note, we find that AFC responses toward influenza virus and Sendai virus differ, even though viral replication is limited to the airway mucosa in each case. The response towards Sendai virus exhibits neither the early appearance of anti‐glycoprotein AFC expressing IgA in draining lymph nodes, nor the subsequent relative deficit of this specificity from bone marrow AFC populations.
Pre‐assembly of the extracellular domains of CD40 is not necessary for rescue of mouse B cells from anti‐immunoglobulin M‐induced apoptosis
Authors: Ellmark Peter ,   CHRISTINA,   FUREBRING, Borrebaeck Carl A. K.
Published: December 2004

CD40 is a tumour necrosis factor receptor (TNFR) family member of central importance for the adaptive immune system. To elucidate the functional role of the different extracellular domains of CD40, we have created a set of truncated CD40 molecules where domains, or parts of domains, have been removed. These CD40 proteins, which contain a peptide tag in the N‐terminal end, have been expressed in a murine B‐cell line, WEHI 231. It was found that ligation of these engineered CD40 proteins via the peptide tag, was sufficient to rescue as well as to promote proliferation of apoptotic WEHI 231 cells, even when all the extracellular domains of CD40 were absent. Our results suggest that pre association of CD40 in the cell membrane plays no critical role for the CD40 signalling pathway. Furthermore, our data imply that conformational changes initiated in the extracellular domains of CD40 are not essential for signal transduction.
Human immunodeficiency virus receptor and coreceptor expression on human uterine epithelial cells: regulation of expression during the menstrual cycle and implications for human immunodeficiency virus infection
Authors: Yeaman Grant R. , Howell Alexandra L. , Weldon Sally , Demian Douglas J. , Collins Jane E. , O'Connell Denise M. , Asin Susana N. , Wira Charles R. , Fanger Michael W.
Published: December 2004

Human immunodeficiency virus‐1 (HIV‐1) is primarily a sexually transmitted disease. Identification of cell populations within the female reproductive tract that are initially infected, and the events involved in transmission of infection to other cells, remain to be established. In this report, we evaluated expression of HIV receptors and coreceptors on epithelial cells in the uterus and found they express several receptors critical for HIV infection including CD4, CXCR4, CCR5 and galactosylceramide (GalC). Moreover, expression of these receptors varied during the menstrual cycle. Expression of CD4 and CCR5 on uterine epithelial cells is high throughout the proliferative phase of the menstrual cycle when blood levels of oestradiol are high. In contrast, CXCR4 expression increased gradually throughout the proliferative phase. During the secretory phase of the cycle when both oestradiol and progesterone are elevated, CD4 and CCR5 expression decreased whereas CXCR4 expression remained elevated. Expression of GalC on endometrial glands is higher during the secretory phase than during the proliferative phase of the menstrual cycle. Because epithelial cells line the female reproductive tract and express HIV receptors and coreceptors, it is likely that they are one of the first cell types to become infected. The hormonal regulation of HIV receptor expression may affect a woman's susceptibility to HIV infection during her menstrual cycle. Moreover, selective coreceptor expression could account for the preferential transmission of R5‐HIV‐1 strains to women. In addition, these studies provide evidence that the uterus, and potentially the entire upper reproductive tract, are important sites for the initial events involved in HIV infection.
X‐chromosome‐linked immune‐deficient mice have B‐1b cells
Authors: Riggs J. , Howell K. , Matechin B. , Matlack R. , Pennello A. , Chiasson R.
Published: December 2004

The B lymphocyte subsets of X‐chromosome‐linked immune‐deficient (XID) mice were examined by flow cytometric analyses of spleen and peritoneal cells. As shown in prior studies, young adult XID mice had reduced representation of the CD5+ (B‐1a) subset in their peritoneal cavity. However, the CD11b+ (B‐1b) B‐cell subset was present and exhibited the IgMhi CD45lo CD23− phenotype characteristic of most B‐1 cells. Although present at a lower frequency than that found in their normal counterparts, B‐1b cells were evident in CBA/N and (XD2J)F1 male mice. With increasing age, B‐1b cell number increased and in the oldest XID mice were present as B‐cell chronic lymphocytic leukaemia. These results show that XID mice do have B‐1 cells, particularly the B‐1b subset.
TRAF6‐NF‐κB pathway is essential for interleukin‐1‐induced TLR2 expression and its functional response to TLR2 ligand in murine hepatocytes
Authors: Matsumura Takayuki , Degawa Takahiro , Takii Takemasa , Hayashi Hidetoshi , Okamoto Takashi , Inoue Jun‐ichiro , Onozaki Kikuo
Published: December 2004

We have previously reported that the expressions of TLR2 and TLR4 mRNA are differentially regulated in mouse liver and in the parenchymal cells. In the present study, we investigated the mechanism of the up‐regulatory effects of interleukin‐1α (IL‐1α), tumour necrosis factor‐α (TNF‐α), lipopolysaccharide (LPS), or bacterial lipoprotein (BLP) on TLR2 mRNA expression in primary cultured murine hepatocytes. Although TLR2 mRNA stability was not affected, these treatments enhanced NF‐κB activity and TLR2 gene transcription simultaneously. The up‐regulation of TLR2 transcription in response to these reagents was completely inhibited by blocking the NF‐κB activation pathway, demonstrating a pivotal role of NF‐κB activation in the regulation of hepatocyte TLR2 transcription. The expression of TLR2 protein by hepatocytes was also remarkably up‐regulated by IL‐1α and, to a lesser extent, by TNF‐α as well, but not by LPS or BLP. In addition, pretreatment of mice with IL‐1α markedly increased the BLP (a ligand for TLR2)‐induced serum level of serum amyloid A (SAA), an acute‐phase protein predominantly produced by hepatocytes, indicating that IL‐1α may also up‐regulate functional TLR2 in vivo. These results demonstrate that IL‐1α, through activating the TRAF6‐NF‐κB pathway, serves as the most potent inducer for TLR2 up‐regulation, and plays an important role in the regulation of hepatocyte functions by augmenting the hepatocyte response to bacteria or bacterial products.