bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Therapeutic Strategy to Treat Brain Ischemia
Authors: Shimamura Munehisa , Sato Naoyuki , Oshima Kazuo , Aoki Motokuni , Kurinami Hitomi , Waguri Satoshi , Uchiyama Yasuo , Ogihara Toshio , Kaneda Yasufumi , Morishita Ryuichi
Published: January 2004

Background—

Although cerebral occlusive disease leads to cerebral ischemic events, an effective treatment has not yet been established. An ideal therapeutic approach to treat ischemia might have both aspects of enhancement of collateral formation and prevention of neuronal death. Hepatocyte growth factor (HGF) is a potent angiogenic factor that also acts as a neurotrophic factor. Thus, in this study, we examined the therapeutic effects of HGF on brain injury in a rat permanent middle cerebral artery occlusion model.

Methods and Results—

Gene transfer into the brain was performed by injection of human HGF gene with hemagglutinating virus of Japan–envelope vector into the cerebrospinal fluid via the cisterna magna. Overexpression of the HGF gene resulted in a significant decrease in the infarcted brain area as assessed by triphenyltetrazolium chloride staining, whereas rats transfected with control vector exhibited a wide area of brain death after 24 hours of ischemia. Consistently, the decrease in neurological deficit was significantly attenuated in rats transfected with the HGF gene at 24 hours after the ischemic event. Stimulation of angiogenesis was also detected in rats transfected with the HGF gene compared with controls. Of importance, no cerebral edema or destruction of the blood-brain barrier was observed in rats transfected with the HGF gene.

Conclusions—

Overall, the present study demonstrated that overexpression of the HGF gene attenuated brain ischemic injury in a rat model, without cerebral edema, through angiogenic and neuroprotective actions. In particular, the reduction of brain injury by HGF may provide a new therapeutic option to treat cerebrovascular disease.
G972R IRS-1 Variant Impairs Insulin Regulation of Endothelial Nitric Oxide Synthase in Cultured Human Endothelial Cells
Authors: Federici Massimo , Pandolfi Assunta , De Filippis Elena Anna , Pellegrini Giuliana , Menghini Rossella , Lauro Davide , Cardellini Marina , Romano Mario , Sesti Giorgio , Lauro Renato , Consoli Agostino
Published: January 2004

Background—

Impaired insulin-mediated vasodilation might contribute to vascular damage in insulin-resistant states. Little is known about insulin regulation of nitric oxide (NO) synthesis in insulin-resistant cells. The aim of this work was to investigate insulin regulation of NO synthesis in human umbilical vein endothelial cells (HUVECs) carrying the IRS-1 gene G972R variant, known to be associated with impaired insulin activation of the PI3-kinase (PI3-K) pathway in transfected cells.

Methods and Results—

HUVECs were screened for the presence of the G972R-IRS-1 (HUVEC-G972R) variant by restriction fragment length polymorphisms. After 24-hour exposure to 10
−7
mol/L insulin, endothelial NO synthase (eNOS) mRNA (reverse transcription–polymerase chain reaction), eNOS protein levels (Western blotting), and NOS activity (conversion of [
3
H]arginine into [
3
H]citrulline) were increased in wild-type HUVECs (HUVEC-WT), whereas they did not change from baseline in HUVEC-G972R. Compared with HUVEC-WT, in HUVEC-G972R after 2 and 10 minutes of insulin stimulation, IRS-1–associated PI3-K activity was reduced by 47% and 32%, respectively; Akt phosphorylation was decreased by 40% at both time points; and eNOS-Ser1177 phosphorylation was reduced by 38% and 51%, respectively. In HUVEC-WT, eNOS-Thr495 phosphorylation decreased after insulin stimulation. In contrast, in HUVEC-G972R, eNOS-Thr495 phosphorylation increased after insulin stimulation and was 40% greater than in HUVEC-WT.

Conclusions—

Our data demonstrate that genetic impairment of the (IRS)-1/PI3-K/PDK-1/Akt insulin signaling cascade determines impaired insulin-stimulated NO release and suggest that the G972R-IRS-1 polymorphism, through a direct impairment of Akt/eNOS activation in endothelial cells, may contribute to the genetic predisposition to develop endothelial dysfunction and cardiovascular disease.
Contribution of Hepatic Cytochrome P450 3A4 Metabolic Activity to the Phenomenon of Clopidogrel Resistance
Authors: Lau Wei C. , Gurbel Paul A. , Watkins Paul B. , Neer Charlene J. , Hopp Amy S. , Carville David G.M. , Guyer Kirk E. , Tait Alan R. , Bates Eric R.
Published: January 2004

Background—

Interindividual variability of platelet inhibition after aspirin or clopidogrel administration has been described. Additionally, aspirin resistance and clopidogrel resistance occur in some individuals. Because the prodrug clopidogrel is activated by hepatic cytochrome P450 (CYP) 3A4, we hypothesized that interindividual variability in clopidogrel efficacy might be related to interindividual differences in CYP3A4 metabolic activity.

Methods and Results—

Platelet aggregation was measured before and after clopidogrel treatment in 32 patients undergoing coronary artery stent implantation and in 35 healthy volunteers. The erythromycin breath test was used to measure CYP3A4 activity in vivo in 25 of the healthy volunteers. Individual platelet aggregation was studied in 10 healthy volunteers after the coadministration of clopidogrel and rifampin (a CYP3A4 inducer). Clopidogrel nonresponders, low responders, and responders were defined by a relative inhibition of adenosine diphosphate (20 μmol/L)–induced platelet aggregation of <10%, 10% to 29%, and ≥30%, respectively. Among patients, 22% were clopidogrel nonresponders, 32% were low responders, and 47% were responders. Among volunteers, 16% were nonresponders, 12% were low responders, and 72% were responders. Percent platelet aggregation after clopidogrel inversely correlated with CYP3A4 activity (
r
=−0.6,
P
=0.003). Improved platelet inhibition in volunteers resistant to clopidogrel was observed with the coadministration of clopidogrel and rifampin.

Conclusions—

Clopidogrel administration results in interindividual variability in platelet inhibition, which correlates with CYP3A4 metabolic activity. Measurement of antiplatelet drug efficacy with a point-of-care device and alternative antithrombotic strategies for aspirin or clopidogrel nonresponders and low responders could reduce the incidence of thrombotic events that continue to occur despite oral antiplatelet therapy.
Primary and Secondary Signaling Pathways in Early Preconditioning That Converge on the Mitochondria to Produce Cardioprotection
Authors: Murphy Elizabeth
Published: January 2004

Cardioprotective mechanisms such as acute or early preconditioning activate several primary signaling pathways that seem to converge on mitochondrial targets, leading to altered cell metabolism and inhibition of apoptosis. Acute preconditioning leads to generation of agonists, which bind to G protein–coupled receptors, and initiates a signaling cascade that involves activation of phosphoinositide-3-kinase, endothelial NO synthase, protein kinase C, glycogen synthase kinase 3β, mitogen-activated protein kinases, and other signaling pathways. Activation of these signaling pathways along with generation of reactive oxygen species leads to alterations in the activity of key mitochondrial proteins such as mitochondrial ATP-sensitive K
+
channels, the mitochondrial permeability transition pore, and bcl-2 family members. Alterations in these mitochondrial proteins results in altered metabolism and inhibition of cell death, thus resulting in cardioprotection.
Clopidogrel-Associated TTP
Authors: Zakarija Anaadriana , Bandarenko Nicholas , Pandey Dilip K. , Auerbach Amy , Raisch Dennis W. , Kim Benjamin , Kwaan Hau C. , McKoy June M. , Schmitt Brian P. , Davidson Charles J. , Yarnold Paul R. , Gorelick Philip B. , Bennett Charles L.
Published: January 2004

Background and Purpose—

Since the 1999 identification of clopidogrel-associated thrombotic thrombocytopenic purpura (TTP) through independent active surveillance, subsequent cases have been identified by pharmaceutical suppliers of clopidogrel and the Food and Drug Administration (FDA). For cases of clopidogrel-associated TTP reported between 1998 to 2002, we evaluated the quality and timeliness of data from 3 reporting systems-independent active surveillance (n=13), pharmaceutical suppliers (n=24), and the FDA (n=13)—and identified prognostic factors associated with mortality.

Methods—

This study assessed the completeness of information on TTP diagnosis, treatment response, and causality from the 3 reporting systems. In addition, predictors of mortality were identified through classification tree analysis.

Results—

Completeness, timeliness, and certainty of diagnosis were best for cases obtained by active surveillance, intermediate for cases reported to the pharmaceutical supplier, and poorest for cases reported directly to the FDA. Clopidogrel had been used for ≤2 weeks by 65%. The survival rate for patients with clopidogrel-associated TTP was 71.2%. Receipt of therapeutic plasma exchange within 3 days of onset of TTP increased the likelihood of survival (100% versus 27.3%,
P
<0.001).

Conclusions—

Compared with reports submitted by suppliers or the FDA, reports obtained through active surveillance provided timelier and more complete information. Clopidogrel-associated TTP often occurs within 2 weeks of drug initiation, occasionally relapses, and has a high mortality if not treated promptly.
Lipid rafts are necessary for tonic inhibition of cellular tissue factor procoagulant activity
Authors: Dietzen Dennis J. , Page Keith L. , Tetzloff Tina A.
Published: January 2004

A fraction of total cellular tissue factor procoagulant activity remains masked or “encrypted” in intact cells. Decryption of this activity partly involves the extracellular exposure of anionic phospholipids such as phosphatidylserine. Because of the potential association of tissue factor and phospholipid scramblase activity with lipid rafts, we have explored the role of lipid rafts in regulating factor VIIa/tissue factor activity. In HEK293 cells, tissue factor antigen was not stably associated with lipid rafts, yet disruption of rafts with methyl-β-cyclodextrin resulted in a 3-fold stimulation of tissue factor procoagulant activity. Treatment with methyl-β-cyclodextrin was not associated with cytotoxicity and did not result in the exposure of additional tissue factor antigen. Factor VIIa/tissue factor activity decrypted with methyl-β-cyclodextrin was quantitatively similar to that obtained by using lytic concentrations of octyl glucoside but more sensitive to inhibition by cell surface tissue factor pathway inhibitor and the phospholipid binding protein, annexin V. Partial decryption of tissue factor was achieved with methyl-β-cyclodextrin prior to complete disruption of lipid rafts, suggesting the role of an enzyme localized to lipid rafts in the transbilayer transport of phosphatidylserine. We conclude that lipid rafts are required for the maintenance of cellular tissue factor in an encrypted state. (Blood. 2004;103:3038-3044)
Reprogramming of human postmitotic neutrophils into macrophages by growth factors
Authors: Araki Hiroto , Katayama Naoyuki , Yamashita Yoshihiro , Mano Hiroyuki , Fujieda Atsushi , Usui Eiji , Mitani Hidetsugu , Ohishi Kohshi , Nishii Kazuhiro , Masuya Masahiro , Minami Nobuyuki , Nobori Tsutomu , Shiku Hiroshi
Published: January 2004

It is generally recognized that postmitotic neutrophils give rise to polymorphonuclear neutrophils alone. We obtained evidence for a lineage switch of human postmitotic neutrophils into macrophages in culture. When the CD15+CD14- cell population, which predominantly consists of band neutrophils, was cultured with granulocyte macrophage–colony-stimulating factor, tumor necrosis factor-α, interferon-γ, and interleukin-4, and subsequently with macrophage colony-stimulating factor alone, the resultant cells had morphologic, cytochemical, and phenotypic features of macrophages. In contrast to the starting population, they were negative for myeloperoxidase, specific esterase, and lactoferrin, and they up-regulated nonspecific esterase activity and the expression of macrophage colony-stimulating factor receptor, mannose receptor, and HLA-DR. CD15+CD14- cells proceeded to macrophages through the CD15-CD14- cell population. Microarray analysis of gene expression also disclosed the lineage conversion from neutrophils to macrophages. Macrophages derived from CD15+CD14- neutrophils had phagocytic function. Data obtained using 3 different techniques, including Ki-67 staining, bromodeoxyuridine incorporation, and cytoplasmic dye labeling, together with the yield of cells, indicated that the generation of macrophages from CD15+CD14- neutrophils did not result from a contamination of progenitors for macrophages. Our data show that in response to cytokines, postmitotic neutrophils can become macrophages. This may represent another differentiation pathway toward macrophages in human postnatal hematopoiesis. (Blood. 2004;103:2973-2980)
Identification of quantitative trait loci that modify the severity of hereditary spherocytosis in wan, a new mouse model of band-3 deficiency
Authors: Peters Luanne L. , Swearingen Rebecca A. , Andersen Sabra G. , Gwynn Babette , Lambert Amy J. , Li Renhua , Lux Samuel E. , Churchill Gary A.
Published: January 2004

Defects in red blood cell (RBC) membrane skeleton components cause hereditary spherocytosis (HS). Clinically, HS varies significantly even among individuals with identical gene defects, illustrating the profound effects of genetic background on disease severity. We exploited a new spontaneous mouse model, wan, which arose on the inbred C3H/HeJ strain, to identify quantitative trait loci (QTL) that modify the HS phenotype. Homozygous wan mice have severe HS due to a complete deficiency of erythroid band 3. A QTL analysis of RBC count, hemoglobin, hematocrit, mean corpuscular volume (MCV), and mean corpuscular hemoglobin content (MCHC) was performed in wan/wan mice from an F2 intercross between C3H/HeJ+/wan and CAST/Ei+/+ F1 hybrids. Hematologic and survival data from C3H, CAST/Ei F2 wan homozygotes support the hypothesis that genetic modifiers significantly influence the band-3 null HS phenotype. Significant QTL were identified for the MCV trait only, suggesting that RBC membrane characteristics are a target for modifier gene action. The most significant quantitative trait locus, Hsm1 (hereditary spherocytosis modifier 1), localizes to mouse Chromosome 12 and is dominant. The peak LOD score was obtained with a marker for Spnb1 encoding erythroid β-spectrin, an obvious candidate gene. (Blood. 2004;103: 3233-3240)
Antigen-selected, immunoglobulin-secreting cells persist in human spleen and bone marrow
Authors: Ellyard Julia I. , Avery Danielle T. , Phan Tri Giang , Hare Nathan J. , Hodgkin Philip D. , Tangye Stuart G.
Published: January 2004

Plasma cells (PCs) represent the final stage of B-cell differentiation and are devoted to the production of immunoglobulin (Ig). Perturbations to their development can result in human disorders characterized by PC expansion and hypergammaglobulinemia. Ig-secreting cells (ISCs) have been identified in secondary lymphoid tissues and bone marrow (BM). Most ISCs in lymphoid tissue are short-lived; in contrast, ISCs that migrate to the BM become long-lived PCs and continue to secrete immunoglobulin for extended periods. However, a small population of long-lived PCs has been identified in rodent spleen, suggesting that PCs may persist in secondary lymphoid tissue and that the spleen, as well as the BM, plays an important role in maintaining long-term humoral immunity. For these reasons, we examined ISCs in human spleen and identified a population that appears analogous to long-lived rodent splenic PCs. Human splenic ISCs shared morphologic, cellular, molecular, and functional characteristics with long-lived PCs in BM, demonstrating their commitment to the PC lineage. Furthermore, the detection of highly mutated immunoglobulin V region genes in splenic ISCs suggested they are likely to be antigen-selected and to secrete high-affinity immunoglobulin. Thus, our results suggest that splenic ISCs have an important role in humoral immunity and may represent the affected cell type in some B-cell dyscrasias.
Leukemic transformation of hematopoietic progenitors by MLL-GAS7 in the absence of Hoxa7 or Hoxa9
Authors: So Chi Wai , Karsunky Holger , Wong Piu , Weissman Irving L. , Cleary Michael L.
Published: January 2004

Differential expression of Hox genes is associated with normal hematopoiesis, whereas inappropriate maintenance of Hox gene expression, particularly Hoxa7 and Hoxa9, is a feature of leukemias harboring mixed-lineage leukemia (MLL) mutations. To understand the pathogenic roles of Hox genes in MLL leukemias, we assessed the impact of Hoxa7 or Hoxa9 nullizygosity on hematopoietic progenitor compartments and their susceptibility to MLL-induced leukemias. Selective reductions in the absolute numbers of committed progenitors, but not of hematopoietic stem cells, distinguished Hoxa7- and Hoxa9-deficient mice. Megakaryocytic/erythroid progenitor (MEP) reductions in Hoxa7-/-mice correlated with reticulocytosis and thrombocytopenia without anemia. Conversely, Hoxa9-/- mice displayed marked lymphopenia and substantial reductions of common lymphoid progenitors (CLPs) and lymphoid precursors, in addition to significant reductions of common myeloid progenitors (CMPs) and granulocyte/monocyte progenitors (GMPs). In retroviral transduction/transplantation assays, Hoxa7- and Hoxa9-deficient progenitors remained susceptible to transformation by MLL-GAS7, which activates MLL through a dimerization-dependent mechanism. However, Hoxa7-/- or Hoxa9-/-progenitors were less efficient in generating transformed blast colony-forming units (CFUs) in vitro and induced leukemias with longer disease latencies, reduced penetrance, and less mature phenotypes. Thus, Hoxa7 and Hoxa9 contribute to hematopoietic progenitor homeostasis but are not necessary for MLL-GAS7–mediated leukemogenesis, yet they appear to affect disease latency, penetrance, and phenotypes consistent with their critical roles as downstream targets of MLL fusion proteins. (Blood. 2004;103:3192-3199)
The effect of oral N-acetylcysteine on lung glutathione levels in idiopathic pulmonary fibrosis
Authors: Meyer A , Buhl R , Magnussen H
Published: January 2004

Idiopathic pulmonary fibrosis (IPF) is characterized by an increased oxidant burden and by a deficiency of glutathione, a major antioxidant, in the lung epithelial lining fluid (ELF). Therefore, a rational therapeutic approach is to reverse the imbalance between oxidants and antioxidants in the lung by enhancing the antioxidant screen. With this background, the aim of our study was to evaluate oral N-acetylcysteine (NAC) as a strategy to augment lung glutathione levels in patients with IPF. Concentrations of total glutathione in bronchoalveolar lavage fluid (BALF) were quantified spectrophotometrically, before and following oral therapy with 3 x 600 mg NAC per day for 5 days, in 17 nonsmoking patients with biopsy-proven IPF. The volume of ELF recovered by BAL was determined using the urea method. Pretherapy, total glutathione levels in ELF in IPF patients were significantly less than normal (187 +/- 36 vs 368 +/- 60 microM), in contrast to levels in BALF (0.99 +/- 0.12 vs 1.18 +/- 0.19 microM). Following therapy with oral NAC, glutathione levels in BALF were 1.54 +/- 0.24 microM (a significant increase compared to pretherapy), whereas the increase in ELF levels (319 +/- 92 microM) did not reach significance. The therapy was well-tolerated, and all routine clinical and bronchoscopic parameters remained unchanged. It is thus feasible and safe to augment deficient lung glutathione levels in patients with IPF; thereby, potentially augmenting pulmonary antioxidant protection.
Oral immunization with bacterial extracts for protection against acute bronchitis in elderly institutionalized patients with chronic bronchitis
Authors: Orcel B , Delclaux B , Baud M , Derenne JP
Published: January 2004

Acute bronchitis is a major source of morbidity in elderly patients. The purpose of this study was to assess the preventive effects of oral immunisation with a bacterial extract. Three hundred and fifty four patients with chronic bronchitis, living in institutions for the elderly (aged > 65 yrs), were included in a randomized, placebo-controlled, double-blind study. The purpose of the study was to assess preventive effects of OM-85 BV (an immunostimulating agent consisting of lyophilized fractions of eight of the most common pathogens isolated in respiratory tract infections) against acute lower respiratory tract infections. Two hundred and ninety patients completed the study (143 taking placebo and 147 taking OM-85 BV). There was a 28% reduction in the number of lower respiratory tract infections in the patients treated with OM-85 BV; this was entirely due to 40% reduction in the number of episodes of acute bronchitis (p < 0.01), with no difference in the number of episodes of pneumonia and bronchopneumonia. A larger number of patients in the OM-85 BV group were free of acute bronchitis throughout the 6 month study period (96 vs 69) and there was a 28% reduction in the number of antibiotic prescriptions in the OM-85 BV treated group. These results suggest that OM-85 BV has a protective effect against acute bronchitis in elderly patients living in institutions.
Reduced endogenous nitric oxide in the exhaled air of smokers and hypertensives
Authors: Schilling J , Holzer P , Guggenbach M , Gyurech D , Marathia K , Geroulanos S
Published: January 2004

We wanted to determine whether the production of endogenous nitric oxide (NO) is affected by cigarette smoking and various pathological conditions. Endogenously produced NO was measured by chemiluminescence in the exhaled air of 81 healthy volunteers (21 nonsmoking females (NSF), 12 smoking females (SF), 24 nonsmoking males (NSM) and 24 smoking males (SM)) and 38 patients (10 with hypertension, 10 intra- and 10 postoperative, 5 with renal failure and 3 with sepsis) entered the protocol. Subjects inspired from a NO-free air supply, which was also used to calibrate the NO-analyser. Endogenous NO production of volunteers was 18 +/- 8 per billion (ppb) depending on smoking habits. In exhaled air of NSF, NO concentration was 21 +/- 7 ppb, in SF 16 +/- 6 ppb, in NSM 19 +/- 8 ppb and in SM 15 +/- 6 ppb. Differences between smokers and nonsmokers were significant. Increased diastolic blood pressure was noted in SM compared to NSM (86 +/- 7 versus 78 +/- 7 mmHg). Patients with documented and treated hypertension (systolic and diastolic blood pressure: 141 +/- 18 and 82 +/- 9 mmHg) exhaled 13.7 +/- 5.3 ppb NO; hypertensive males 10 +/- 2 ppb NO and females 17 +/- 5 ppb NO. In patients with renal failure NO concentration in exhaled air was 20.2 +/- 6.8 ppb before and 19.8 +/- 6.4 ppb one hour after the onset of dialysis. In patients undergoing major surgery NO concentration was 5.6 +/- 2.5 ppb intra- and 10.3 +/- 3.5 ppb postoperatively. In three mechanically ventilated patients with documented septic syndrome, exhaled NO was 29.3 +/- 24 ppb.(ABSTRACT TRUNCATED AT 250 WORDS)
Relationship between cotinine levels, household and personal smoking habit and season in 9-14 year old children
Authors: Ronchetti R , Bonci E , de Castro G , Signoretti F , Macri F , Ciofetta GC , Villa MP , Indinnimeo L , Martinez FD
Published: January 2004

The aim of this study was to determine the relationship of salivary cotinine levels with individual and household smoking habits and with the season in a sample (n = 146) of Italian schoolchildren aged 9-14 yrs. Active smoking and environmental tobacco smoke were measured by means of a confidential standardized interview with each participating child and by a self-reported questionnaire administered to the parents. Saliva samples were obtained twice: during winter from all children and during spring from a randomly selected subgroup. "Active smokers" were significantly more likely to be males and to live with smoking family members. Frequency of detectable cotinine both in "nonsmokers" and "active smokers" was significantly correlated with the number of cigarettes smoked by household members. However, for any level of smoking by parents detectable cotinine was more likely to be found in "active smokers" than in "nonsmokers". In "nonsmokers", the proportion of subjects with detectable cotinine decreased significantly in spring compared to winter, a finding not observed in "active smokers". In conclusion, we have demonstrated that passive smoking produces most effect in winter, and is linked to the amount and style of the parents' smoking, mainly related to smoking in presence of children. Conversely, salivary cotinine detected in spring appears to be derived mainly from active smoking.
Gender difference in smoking effects on adult pulmonary function
Authors: Xu X , Li B , Wang L
Published: January 2004

Data on 1,618 male and 1,669 female adults aged 40-69 yrs, from China in the Beijing Respiratory Health Study, were analysed to investigate the gender differences in effects of smoking on pulmonary function. Smoking was characterized by total smoking-years, smoking status (former, transitional and constant), smoking type (cigarette, cigar and others). The effects of smoking on height-standardized forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) were assessed by multiple regressions adjusting for age, education level, use of an indoor coal stove for heating, passive smoking, occupational dust and gas/fume exposure, and residence. Prediction equations were derived from nonsmoking asymptomatic subjects. As compared to women, men had a much higher smoking prevalence (78 vs 35%) but a lower quitting rate (14 vs 23%). Female lifetime nonsmokers had greater mean percentage predicted lung function values than male lifetime nonsmokers, whilst female cigarette smokers had lower values than their male counterparts. In both sexes, the highest mean percentage predicted lung function values were found in lifetime nonsmokers, whilst the lowest values were found among former smokers, the second lowest among transitional smokers, and constant smokers actually had greater values than both former and transitional smokers. These findings were confirmed by sex-specific regression analyses. A global test on the interactions between smoking and sex was highly significant. This study suggests that adverse smoking effects on pulmonary function were greater in women than in men.(ABSTRACT TRUNCATED AT 250 WORDS)
Measurement of bronchial responsiveness by forced oscillation technique in occupational epidemiology
Authors: Pairon JC , Iwatsubo Y , Hubert C , Lorino H , Nouaigui H , Gharbi R , Brochard P
Published: January 2004

The performance of the forced oscillation technique (FOT) in the assessment of bronchial responsiveness on the methacholine challenge test was compared with that of forced expiratory volume in one second (FEV1) in 119 active workers with normal baseline pulmonary function. Changes in resistance (delta R0%), frequency dependence of resistance (delta P) and resonant frequency (delta F%) determined by the FOT were compared to the delta FEV1%. Receiver operating characteristic (ROC) curves were established to determine values of the changes in FOT parameters which corresponded to the best sensitivity and specificity for classifying the subjects as hyperresponsive or nonresponsive on the methacholine challenge test. Significant correlations were observed between delta FEV1% and delta R0%, delta P and delta F% respectively. The ROC curves showed the following cut-off values of FOT parameters to be the best values for classifying the subjects according to the presence or absence of 20% fall in FEV1: a 65% increase in R0 (sensitivity 75%; specificity: 76%); a decrease of 65 x 10(-3) hPa.l-1.s2 in P (sensitivity 58%; specificity 83%); a 50% increase in F (sensitivity 75%; specificity 62%). Our results suggest that the FOT is a useful test for assessment of bronchial hyperresponsiveness when compared to spirometry, and can be applied to epidemiological studies of a bronchial challenge test in normal active working populations.
A comparison of asthma deaths and near-fatal asthma attacks in South Australia
Authors: Campbell DA , McLennan G , Coates  , Frith PA , Gluyas PA , Latimer KM , Luke CG , Martin AJ , Roder DM , Ruffin RE , et al.
Published: January 2004

Studies seeking to identify factors predictive of asthma mortality have relied on information obtained from relatives, other close acquaintances, and doctors who cared for the deceased. We wanted to determine whether asthmatics who have suffered a near-fatal asthma attack (NFA) are similar to asthmatics who have died of asthma with respect to important features, because studies of NFA asthmatics may provide a better insight into causes of asthma death. Such studies would avoid the difficulties associated with seeking information secondhand from proxy informants. Two groups were studied: asthmatics who had suffered a near-fatal asthma attack resulting in a visit to the accident and emergency departments of teaching hospitals (n = 154), and asthmatics certified as dying of asthma who, following panel review, were confirmed to have died from this disease (n = 80). For each case in the two groups, an interview questionnaire was administered to a close acquaintance (household or family member) and to the general practitioner. Both groups shared many important characteristics. Similarities related to: frequency of symptoms; frequency of hospital and intensive care unit admissions for asthma; use of asthma crisis plans; compliance with prescribed medications; quality of personal asthma management; and asthma severity. The two groups also showed similar psychiatric profiles, and similar use of asthma medications on a regular basis and with increased symptoms. However, NFA cases tended to be younger, were more likely to be male, and less likely to have concurrent medical conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
Prescribed drug therapy and near-fatal asthma attacks
Authors: Burgess C , Pearce N , Thiruchelvam R , Wilkinson R , Linaker C , Woodman K , Crane J , Beasley R
Published: January 2004

Inhaled fenoterol has been associated with an increased risk of death in severe asthmatics, when compared to other adrenoceptor agonists. It is plausible that fenoterol may also increase the risk of near-fatal attacks. We have conducted a case-control study to investigate this hypothesis. The cases comprised Intensive Care Unit (ICU) admissions for asthma in the Wellington region during 1977-1988. For each of these cases, two age-matched controls were selected from asthma admissions to the same hospital during the same period. For the 155 cases and 305 controls, information on prescribed drug therapy was collected from the hospital admission records. The relative risk of a near-fatal asthma attack in patients prescribed inhaled fenoterol was 2.00 (95% confidence interval (CI) 1.35-2.97). An increased risk was also observed for oral theophylline (odds ratio (OR) = 1.88; 95% CI 1.26-2.79). For the 65 cases and 104 controls who had a previous admission for asthma in the previous 12 months, information relating to the previous admission was also collected; an increased risk was once again observed for inhaled fenoterol (OR = 2.18; 95% CI 1.10-4.33) and for oral theophylline (OR = 1.18; 95% CI 0.99-3.57). No other asthma drugs showed significantly increased risks. Although the ICU admission cases had generally been prescribed more asthma drugs than the hospital admission controls, and appeared to have more severe asthma, it is possible that the findings reported here are influenced by confounding by severity. We nevertheless estimate that our findings are consistent with the hypothesis that fenoterol increases the risk of near-fatal asthma attacks, and that they complement previous findings on fatal asthma attacks.(ABSTRACT TRUNCATED AT 250 WORDS)
Measurement of the internal size of bronchi using high resolution computed tomography (HRCT)
Authors: Seneterre E , Paganin F , Bruel JM , Michel FB , Bousquet J
Published: January 2004

Computed tomography (CT) of the lungs makes it possible to study individual airways. A technique using high-resolution-CT (HRCT) has been developed to measure the internal size of the bronchi. Five normal subjects had a conventional HRCT scan at full, deep inspiration. The internal size of the airways from segmental to the sixth generation bronchi was measured using an original method of data analysis. The size of the airways ranged 0.5-50 mm2 (approximately 0.8-8 mm in diameter. The technique was found to be highly reproducible, making it possible to study the variation in airways calibre after provocative challenge or administration of bronchodilator in asthma.
Input respiratory impedance to estimate airway hyperreactivity in children: standard method versus head generator
Authors: Marchal F , Mazurek H , Habib M , Duvivier C , Derelle J , Peslin R
Published: January 2004

We previously found that a significant underestimation of respiratory mechanical impedance (Zrs) at high frequency may result from the upper airway artefact in children, when pressure is directly varied at the mouth. To determine the importance of this artefact in estimating lung response to bronchomotor agents with the forced oscillation technique, input respiratory mechanical impedance was measured using 6-32 Hz pseudorandom pressure oscillations applied directly to the mouth (standard generator (SG)) and around the subject's head (head generator (HG)) in 35 children aged 2.5-13 yrs. Changes in resistance were generally larger with HG than SG. The mean +/- SEM changes in resistance of the respiratory system (Rrs) at 20 Hz induced by acetylcholine or allergen challenge were 15 +/- 4% for SG and 67 +/- 12% for HG, and changes induced by bronchodilators were -25 +/- 2% for SG, and -46 +/- 4% for HG (p < 0.01). Challenge induced negative frequency dependence of Rrs with SG and positive frequency dependence with HG. There was significant increase in inertance after salbutamol with SG, but no significant change occurred with HG. With both methods, respiratory compliance decreased significantly after challenge. Computer simulations showed that the difference in change in Rrs induced by airway challenge with HG and SG could be explained by the effect of the upper airway wall impedance (Zuaw). Zuaw could also account for the change in inertance and compliance observed with SG, but not for the change in compliance with HG. The latter could be reproduced by simulating unequal distribution of mechanical time constants within the lung, increased peripheral lung resistance with compliant central airways.(ABSTRACT TRUNCATED AT 250 WORDS)
GRK6 deficiency is associated with enhanced CXCR4-mediated neutrophil chemotaxis in vitro and impaired responsiveness to G-CSF in vivo
Authors: Vroon Anne , Heijnen Cobi J , Raatgever Roel , Touw Ivo P , Ploemacher Rob E , Premont Richard T , Kavelaars Annemieke
Published: January 2004

The stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) signaling pathway is thought to play an important role in the induction of neutrophil mobilization from the bone marrow in response to granulocyte-colony stimulating factor (G-CSF) treatment. CXCR4 belongs to the family of G protein-coupled receptors. Multiple members of this receptor family are desensitized by agonist-induced G protein-coupled receptor kinase (GRK)-mediated phosphorylation. Here, we demonstrate that in vitro SDF-1-induced chemotaxis of bone marrow-derived neutrophils from GRK6-deficient mice is significantly enhanced and that desensitization of the calcium response to SDF-1 is impaired in GRK6−/− neutrophils. CXCR4 activation by SDF-1 provides a key retention signal for hematopoietic cells in the bone marrow. It is interesting that we observed that in the absence of GRK6, the G-CSF-induced increase in circulating neutrophils is profoundly impaired. Three days after injection of pegylated-G-CSF, significantly lower numbers of circulating neutrophils were observed in GRK6−/− as compared with wild-type (WT) mice. In addition, early/acute neutrophil mobilization in response to G-CSF (3 h after treatment) was also impaired in GRK6−/− mice. However, blood neutrophil levels in untreated GRK6−/− and WT mice were not different. Moreover, the percentage of neutrophils in the bone marrow after G-CSF treatment was increased to the same extent in WT and GRK6−/− mice, indicating that neutrophil production is normal in the absence of GRK6. However, the increased chemotactic sensitivity of GRK6−/− neutrophils to SDF-1 was retained after G-CSF treatment. In view of these data, we suggest that the impaired G-CSF-induced neutrophil mobilization in the absence of GRK6 may be a result of enhanced CXCR4-mediated retention of PMN in the bone marrow.
Neutrophil chemoattractant genes KC and MIP-2 are expressed in different cell populations at sites of surgical injury
Authors: Armstrong David A , Major Jennifer A , Chudyk Alison , Hamilton Thomas A
Published: January 2004

KC and macrophage-inflammatory protein-2 (MIP-2) are CXC chemokines that exhibit distinct temporal patterns of expression in the skin following surgical injury. In situ hybridization analysis demonstrates that these two chemokines are expressed by distinct cell types at different times following injury. Dermal fibroblasts and endothelial cells are primarily responsible for KC expression in the skin 6 h following surgery. In contrast, MIP-2 production appears to be restricted to infiltrating inflammatory leukocytes including neutrophils and monocytes, which appear later in the response. This cell type-specific pattern of chemokine expression is recapitulated in vitro using isolated primary- and long-term-cultured cell types. Primary dermal fibroblasts stimulated with interleukin-1α express predominantly KC and very little MIP-2, and peritoneal exudate neutrophils produce as much or more MIP-2 as KC following stimulation in vitro. Although a collection of exogenous stimuli can induce expression of KC and MIP-2, the quantitative ratio for expression reflects the cell type and not the stimulus. The selective expression of KC over MIP-2 in endothelial cells results from markedly greater KC gene transcription and not from alterations in the rate of mRNA decay. These results demonstrate that distinct CXC chemokines show restricted expression in myeloid versus nonmyeloid cell types and that patterns of chemokine expression at sites of inflammation in vivo reflect the temporally ordered contribution of these distinct cell types.
The receptor tyrosine kinase MerTK activates phospholipase C γ2 during recognition of apoptotic thymocytes by murine macrophages
Authors: Todt Jill C , Hu Bin , Curtis Jeffrey L
Published: January 2004

Apoptotic leukocytes must be cleared efficiently by macrophages (Mø). Apoptotic cell phagocytosis by Mø requires the receptor tyrosine kinase (RTK) MerTK (also known as c-Mer and Tyro12), the phosphatidylserine receptor (PS-R), and the classical protein kinase C (PKC) isoform βII, which translocates to Mø membrane and cytoskeletal fractions in a PS-R-dependent manner. How these molecules cooperate to induce phagocytosis is unknown. As the phosphatidylinositol-specific phospholipase (PI–PLC) γ2 is downstream of RTKs in some cell types and can activate classical PKCs, we hypothesized that MerTK signals via PLC γ2. To test this hypothesis, we examined the interaction of MerTK and PLC γ2 in resident, murine peritoneal (P)Mø and in the murine Mø cell line J774A.1 (J774) following exposure to apoptotic thymocytes. We found that as with PMø, J774 phagocytosis of apoptotic thymocytes was inhibited by antibody against MerTK. Western blotting and immunoprecipitation showed that exposure to apoptotic cells produced three time-dependent changes in PMø and J774: tyrosine phosphorylation of MerTK; association of PLC γ2 with MerTK; and tyrosine phosphorylation of PLC γ2. Cross-linking MerTK using antibody also induced phosphorylation of PLC γ2 and its association with MerTK. A PI–PLC appears to be required for phagocytosis of apoptotic cells, as the PI–PLC inhibitor Et-18-OCH3 and the PLC inhibitor U73122, but not the inactive control U73343, blocked phagocytosis without impairing adhesion. On apoptotic cell adhesion to Mø, MerTK signals at least in part via PLC γ2.
Combined activation of innate and T cell immunity for recognizing immunomodulatory properties of therapeutic agents
Authors: Rose Bettina , Herder Christian , Löffler Heike , Kolb Hubert , Martin Stephan
Published: January 2004

Complex syndromes such as atherosclerosis and type 2 diabetes are disorders that are associated with inflammatory processes involving innate and adaptive immunity. Emerging knowledge about the pathological consequences of immune imbalances in a wide range of disease settings is expected to help to identify novel therapeutic targets. However, current test systems for immunomodulatory drugs tend to be too simplistic, as they rely only on cells of the innate- or the adaptive-immune system, or they are complex, in vivo models, which are not suitable for screening purposes. Using a modified mixed lymphocyte culture (MMLC) assay for combined analysis of innate and adaptive immunity, we show that this assay is very sensitive for the presence of low concentrations of immunomodulatory agents. Low-dose lipopolysaccharide stimulation of cells from two unrelated donors yields a strong cytokine response including interleukin (IL)-12 and IL-18, which induce interferon-γ as a potential analysis parameter. As the MMLC assay is based on the mutual interaction of cells of the innate and adaptive immunity, it enables the monitoring of cytokine release under almost physiological conditions and might be of interest for the characterization of known and novel drugs concerning their immunomodulatory potency.
Multivariable nonlinear model reference control of cement mills
Authors: Efe Mehmet önder
Published: January 2004

This paper presents a method for model reference control of a cement milling circuit that has previously been studied several times. The approach presented is based on an experimentally justified model of a cement milling circuit. We derive the form of the control vector with the goal of driving the response of the system to that of a desired model in a noisy operating environment. The paper demonstrates the selection of the reference dynamics and the derivation of the control laws. The approach is based on the Lyapunov theory, and the results observed justify the tracking and stability claims of the paper.
Experimental and model-assisted investigation of activities in a water supply system
Authors: Eker Ilyas , Kara Tolgay
Published: January 2004

This paper presents experimental and model-assisted investigation of activities in a water supply system to manage water transfer using some experiments that are performed on the real system, and simulations obtained from a nonlinear model of the system. The physical system consists of a sequence of pumping stations that deliver water through pipelines to intermediate storage reservoirs. The nonlinear model is obtained using dominant system variables that represent active and passive dynamical elements. The hydraulic models include nonlinear coupling between flow rates and reservoir heads. Validation of the nonlinear model is accomplished through comparing with system observations and using data validation and face validity approaches. The results demonstrate the dynamical behaviour of the system regarding flow stability, water heads in the reservoirs, head losses and measure of the friction at different sections of the water supply system.
The validity of questionnaire measures for assessing depression after stroke
Authors: Lincoln N B , Nicholl C R , Flannaghan T , Leonard M , Van der Gucht E
Published: January 2004

Objective: Depression has been reported to occur frequently after stroke. The aim of the study was to assess the validity of questionnaire measures for screening for depression after stroke.

Design: Cross-sectional correlational study between questionnaire measures of mood and psychiatric interview.

Setting: Hospital and community.

Participants: Stroke patients were recruited from hospital wards and from a randomized controlled trial of cognitive behavioural therapy.

Main measures: Beck Depression Inventory, Wakefield Depression Inventory, General Health Questionnaire 28 and Schedules for Clinical Assessment in Neuropsychiatry.

Results: Poor agreement was found between psychiatric diagnosis and questionnaire measures of mood. The sensitivity of the questionnaire measures was high, but specificity was low. No cut-off points with satisfactory sensitivity and specificity could be identified from ROC curves.

Conclusions: Although questionnaire assessments of depression provide a satisfactory screening method, specificity values are too low to provide a basis for the diagnosis of depression. Measures need to be developed with higher specificity to facilitate screening for depression after stroke.
A post-discharge quality of life outcome measure for lower limb amputees: test–retest reliability and construct validity
Authors: Callaghan B G , Condie M E
Published: January 2004

Objective: To adapt the Patient Generated Index (PGI) quality of life measure for use with lower limb amputees and to conduct a test–retest reliability and construct validity study on the adapted measure.

Design: Repeat questionnaire interviews with a four-week interval administered by trained peers.

Setting: Participants' homes.

Subjects: Forty-two unilateral lower limb transfemoral amputees, 16 years of age or older and fluent in English, fitted with a prosthesis and discharged into the community for at least one year following postoperative rehabilitation therapy.

Main results: An intraclass correlation coefficient of 0.48 ( p < 0.001) was achieved for the index reliability analyses. Intraclass correlation (ICC) values for the seven most commonly mentioned areas of life affected by the amputation and its treatment ranged from 0.40 to 0.92. Comparing the PGI with the SF-12 Health Survey physical and mental component summaries gave Pearson's correlation coefficients of 0.12 ( p < 0.5) and 0.56 ( p < 0.001) respectively. Multiple linear regression analysis showed the SF-12 physical and mental component scores explained 31.5% of the variability in PGI scores, however, the mental component scores alone explained 31.2%.

Conclusions: The PGI was adapted and found to be moderately reliable in terms of repeatability during successive follow-up interviews. Testing its construct validity supported a stronger relationship between mental health and quality of life than between physical health and quality of life.