bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SUMMARYQuinoxyfen 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

SUMMARYThe 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

SummaryOwing 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

SummaryIt 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

SummaryC‐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

SummaryOur 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.