bluuebunny/crossref_metadata_2025 huggingface dataset:
Hyperbilirubinemic Serum Is Cytotoxic and Induces Apoptosis in Murine Astrocytes
Authors: Kumral Abdullah , Genc Sermin , Genc Kursad , Duman Nuray , Tatli Mansur , Sakizli Meral , Özkan Hasan
Published: November 2004

Background: High levels of unconjugated bilirubin can be neurotoxic and gliotoxic. However, the effect of serum from patients with neonatal indirect hyperbilirubinemia on astrocyte viability has never been investigated. Objectives: In the present study, we searched for the possible toxic effect of hyperbilirubinemic serum on murine astrocytes. Methods: Heat-inactivated patient serum was added to astrocyte cultures at different concentrations varying from 1 to 20%, and cultures were incubated for 24, 48, and 72 h. Sera from healthy infants without hyperbilirubinemia were used as controls. Cytotoxicity was evaluated according to the release of lactate dehydrogenase in the culture medium. Apoptotic cell death was determined by anti-single-strand DNA immunostaining. Results: The results of the present study show that hyperbilirubinemic serum induces cytotoxicity and apoptotic astrocyte death in a concentration- and time-dependent manner. Conclusions: We conclude that serum from patients with neonatal indirect hyperbilirubinemia is cytotoxic to murine astrocytes.
Effects of Combined Estriol/Pravastatin Therapy on Intima-Media Thickness of Common Carotid Artery in Hyperlipidemic Postmenopausal Women
Authors: Yamanaka Yoshihiko , Matsuo Hiroya , Kurachi Osamu , Oki Noriyoshi , Nakago Satoshi , Takeuchi Kyousuke , Maruo Takeshi
Published: November 2004

Background: Several studies show that 17β-estradiol (E2) has protective effects on atherosclerosis in the arterial wall in postmenopausal women. Little information is, however, available regarding the effect of estriol (E3) on atherosclerosis. This study was conducted to investigate the effects of E3 alone and combined E3/pravastatin therapy on intima-media thickness (IMT) of common carotid artery in postmenopausal women. Methods: Thirty-three postmenopausal women were allocated to four groups: daily treatment with E3 (2 mg) alone (E3 group, n = 10), pravastatin (10 mg) alone (pravastatin group, n = 6), combined treatment with E3 (2 mg) and pravastatin (10 mg; E3/pravastatin group, n = 7) and untreated control group (n = 10). All women attended the Kobe University Hospital once a year for routine gynecological and ultrasonographic examinations for the evaluation of atherosclerosis. Results: A significant decrease in IMT was noted in the E3/pravastatin group compared with that in the untreated control group (p < 0.05), whereas there was no significant difference in the reduction rate of IMT in the pravastatin group, E3 group and untreated control group. Conclusions: The combined E3/pravastatin therapy appeared to retard the progression of atherosclerosis in postmenopausal women.
Increase in Collagen Turnover But Not in Collagen Fiber Content Is Associated with Flow-Induced Arterial Remodeling
Authors: Sluijter Joost P.G. , Smeets Mirjam B. , Velema Evelyn , Pasterkamp Gerard , de Kleijn Dominique P.V.
Published: November 2004

Background: Degradation and synthesis of collagen are common features in arterial geometrical remodeling. Previous studies described an association between arterial remodeling and an increase in collagen fiber content after balloon injury. However, this does not exclude that the association between collagen content and remodeling depends on arterial injury since the association of collagen fiber content and arterial remodeling, without arterial injury, has not been investigated. The aim of the present study was to study the relation between flow-induced arterial geometrical remodeling, without arterial injury, and collagen synthesis and degradation, collagen fiber content and cell-migration-associated moesin levels. Methods and Results: In 23 New Zealand White rabbits an arteriovenous shunt (AV shunt) was created in the carotid and femoral artery to induce a structural diameter increase or a partial ligation (n = 27 rabbits) to induce a diameter decrease. In both models, arterial remodeling was accompanied by increased procollagen synthesis, reflected by increased procollagen mRNA or Hsp47 protein levels. In both models, however, no changes were detected in collagen fiber content. Active MMP-2 and moesin levels were increased after AV shunting. Conclusions: Collagen synthesis and MMP-2 activation were associated with arterial remodeling. However, a change in collagen fiber content was not observed. These results suggest that, during flow-induced geometrical arterial remodeling, increases in collagen synthesis are used for matrix collagen turnover and cell migration but not to augment collagen fiber content.
Serum Amyloid A Protein Is a Useful Inflammatory Marker during Late-Onset Sepsis in Preterm Infants
Authors: Arnon Shmuel , Litmanovitz Ita , Regev Rivka , Bauer Sofia , Lis Monica , Shainkin-Kestenbaum Ruth , Dolfin Tzipora
Published: November 2004

Background: Few studies demonstrated that serum amyloid A (SAA), a non-specific acute-phase reactant, could be used as a reliable early marker for the diagnosis of late-onset sepsis (LOS). Objectives: To evaluate the diagnostic value and the dynamics of SAA levels during the course of LOS and to compare it to those of other inflammatory markers. Methods: Levels of SAA, C-reactive protein (CRP) and IL-6 together with clinical variables, biochemical parameters and cultures retrieved from all preterm infants suspected of LOS were checked at the first suspicion of sepsis and after 8, 24, 48 and 72 h. Results were compared to healthy, matched infants. Results: One hundred and sixteen infants were included in the study, 38 in the sepsis and 78 in the non-sepsis group. High levels of SAA were observed at sepsis onset, with a gradual decline thereafter, while CRP levels increased only at 24 h after sepsis onset. In the sepsis group, levels of SAA returned faster to baseline than CRP levels. Receiver-operating characteristic analysis values revealed that SAA at 10 µg/ml had the highest sensitivity at 0, 8 and 24 h after sepsis onset (95, 100 and 97%, respectively) and a negative predictive value (97, 100 and 98%, respectively). Conclusions: SAA is an accurate acute-phase protein during LOS in preterm infants. Quick and reliable SAA kits can make this marker a useful tool in LOS in preterm infants.
Facial Expression and Experience of Emotions in Psychodynamic Interviews with Patients Suffering from a Pain Disorder
Authors: Merten Jörg , Brunnhuber Stefan
Published: November 2004

In clinical practice, it is often difficult to establish a positive relationship with patients suffering from psychogenic pain disorder. The present study addresses this maladaptive relationship pattern that is characterized by a mixture of disappointment and rejection. Facial expressions of emotions of 21 female patients in psychodynamic interviews were analyzed and compared to a control group of 11 healthy subjects. The assumption of a maladaptive relationship pattern is supported by an increase in negative facial expressions, especially contempt, on the side of the patients and the interviewer. These negative emotions indicate a disorder of self- and relationship regulation and are negatively correlated with the level of structural personality organization (as measured by the operationalized psychodynamic diagnostic). They also correlate with the emotional experience of shame and fear and are negatively correlated with the experience of joy. The results demonstrate how maladaptive relationship patterns are implemented at the level of involuntary emotional behavior. They can help to understand and improve the emotional quality of therapeutic relationships.
Interactive Regulation of Affect in Postpartum Depressed Mothers and Their Infants: An Overview
Authors: Reck Corinna , Hunt Aoife , Fuchs Thomas , Weiss Robert , Noon Andrea , Moehler Eva , Downing George , Tronick Edward Z. , Mundt Christoph
Published: November 2004

Specific patterns of interaction emerging in the first months of life are related to processes regulating mutual affects in the mother-child dyad. Particularly important for the dyad are the matching and interactive repair processes. The interaction between postpartum depressed mothers and their children is characterized by a lack of responsiveness, by passivity or intrusiveness, withdrawal and avoidance, as well as a low level of positive expression of affect. Thus, an impaired capability to regulate the child’s affect has been demonstrated in depressed mothers. Maternal aggression, neglect toward infants, infanticidal thoughts, as well as infanticidal behavior are mainly linked to severe postpartum depression, especially with psychotic symptoms. The findings on mother-child interaction reported in this paper are based on mothers with mild to moderate depressive disorders without psychotic symptoms. Considering the stability of interaction patterns in the course of depressive illness as well as the long-term consequences of these interactions, it seems surprising that there are still few systematic studies of depressed mothers interacting with their infants.In connection with an overview on these issues, treatment models forparent-infant psychotherapy are discussed.
Dissociative Symptoms in Schizophrenia: A Comparative Analysis of Patients with Borderline Personality Disorder and Healthy Controls
Authors: Brunner Romuald , Parzer Peter , Schmitt Regina , Resch Franz
Published: November 2004

The aim of this study was to investigate the occurrence of dissociative symptoms in patients with a schizophrenic disorder. The pattern of dissociative experiences was examined in a group of patients with a diagnosis of the schizophrenia spectrum disorder (n = 26; mean age 27.9 years), and a group of patients with a diagnosis of borderline personality disorder (n = 26; mean age 24.0 years) was compared with normal controls of the general population (n = 1,056; mean age 18.7 years). The degree of self-reported dissociative symptoms was measured using the German version of the Dissociative Experiences Scales. The dissociation scores were significantly higher among patients with a diagnosis of borderline personality disorder compared to the group of schizophrenic patients and to the control group. There was no difference in the degree of reported dissociative experiences between the group of schizophrenic patients and the normal volunteers. An analysis of the subdimensions (dissociative amnesia, absorption/imaginative involvement, depersonalization/derealization) of the scale revealed the same strong distinctions between the investigated groups. There was no evidence that dissociative symptoms reflect a specific vulnerability in young schizophrenic patients.
Different Perceived Foreign Accents in One Patient after Prerolandic Hematoma
Authors: Christoph D.H. , de Freitas G.R. , dos Santos D.P. , Lima M.A.S.D. , Araújo A.Q.C. , Carota A.
Published: November 2004

Foreign accent syndrome (FAS), a rare disorder characterized by the emergence of a new accent perceived as foreign by listeners, is usually reported with left brain damage. We here report the case of a 28-year-old native Brazilian who appeared, to the examiner, to show a North American accent during recovery from Broca’s aphasia. The lesion was due to a frontal hematoma. Without referring specifically to speech, we asked 10 independent observers to comment on a videotape of the patient’s interview. Seven reported that the patient had a foreign accent, while 3 simply noted a ‘strange’ accent. The observers did not agree on the origin of the accent, 5 identifying it as Spanish, 1 as German, and 1 as south Brazilian. These findings suggest that FAS is not due to the acquisition of a specific foreign accent, but to impairment of the suprasegmental linguistic abilities (tone, accent, pauses, rhythm, and vocal stress) that make it possible to distinguish native language.
Central Representation of Somatic Sensations in the Parietal Operculum (SII) and Insula
Authors: Bowsher David , Brooks Jonathan , Enevoldson Peter
Published: November 2004

Four subjects with small restricted cerebral cortical infarcts have been examined. One had a lesion confined to the parietal operculum (SII), while in the second the SII lesion also encroached on the posterior insula; in the third subject, both banks of the sylvian fissure and the dorsal insula were involved, while in the fourth the lesion involved the upper bank of the sylvian fissure. In all cases, the postcentral gyrus (SI) was intact. Subjects 1 and 2 had mild spontaneous pain, but subjects 3 and 4 had never had spontaneous pain. In the affected areas, none could feel mechanical (skinfold pinch) pain. The 2 subjects with spontaneous pain could not discriminate sharpness (pinprick), but this was unimpaired in the third and fourth subjects. Warmth, cold, and heat pain were impaired in the 2 subjects with spontaneous pain, but not in those without; however warm-cold difference was greater in the affected regions of all subjects. The possibility must nevertheless be considered that the presence of central pain in some way alters the cortical mechanisms for the perception of thermal stimuli. Certainly, as we had earlier observed, spontaneous pain only occurs when there is interference with thermal sensation. Functional MRI (fMRI) studies following thermal stimulation in subjects 1 and 2 showed these areas, particularly SII, to be concerned with the reception of innocuous and noxious thermal stimuli, mechanical (skinfold pinch) pain and sharpness (pinprick), implying that SI is principally concerned with the reception of low-intensity mechanical stimuli, although it was activated in 1 of our fMRI-studied subjects by innocuous cooling.
LMNA Mutations in Cardiac Transplant Recipients
Authors: Pethig Klaus , Genschel Janine , Peters Tina , Wilhelmi Mathias , Flemming Peer , Lochs Herbert , Haverich Axel , Schmidt Hartmut H.-J.
Published: November 2004

Lamin A and C are components of the nuclear envelope, located at the nucleoplasmatic surface of the inner nuclear membrane within cells. Recently, mutations within LMNA encoding lamin A/C have been associated with various disease entities including cardiomyopathy. We screened heart transplant recipients suffering from dilated cardiomyopathy (DCM) with a positive family history of LMNA mutations. Four index patients and one relative belonging to four unrelated families carrying LMNA mutations were identified. The mutations p.Q355X and p.S22L have not been reported before, whereas p.R190W has already been reported in other studied DCM cohorts. In the patients of the present study, the mean age at manifestation of heart disease was 37.6 years (range 30–45 years), with progression to end-stage heart failure requiring transplantation at a mean age of 45.8 years (range 35–54 years). Three patients presented initially with atrial fibrillation. These data confirm the involvement of LMNA mutations in patients with DCM and extend the mutational spectrum of LMNA. The p.R190W mutation has been reported in different populations and may therefore be useful for analyzing the impact of a specific LMNA mutation on the phenotype of muscle disease.
Mouse Models of Atopic Eczema Critically Evaluated
Authors: Gutermuth Jan , Ollert Markus , Ring Johannes , Behrendt Heidrun , Jakob Thilo
Published: November 2004

Atopic eczema (AE) is a chronic relapsing inflammatory skin disorder with increasing prevalence in Western societies. Even though we have made considerable progress in understanding the cellular and molecular nature of cutaneous inflammation, the precise pathomechanisms of AE still remain elusive. Experimental animal models are indispensable tools to study the pathogenic mechanisms and to test novel therapeutic approaches in vivo. For AE a considerable number of mouse models have been proposed and have been used to study specific aspects of the disease, such as genetics, skin barrier defects, immune deviations, bacteria–host interactions or the role of cytokines or chemokines in the inflammatory process. While some models closely resemble human AE, others appear to reflect only specific aspects of the disease. Here we review the currently available mouse models of AE in light of the novel World Allergy Organization classification of eczematous skin diseases and evaluate them according to their clinical, histopathological and immunological findings. The pathogenetic analogies between mice and men will be discussed.
The Major Histopathologic Characteristics in the Vulvar Vestibulitis Syndrome
Authors: Halperin Reuvit , Zehavi Sergei , Vaknin Zvika , Ben-Ami Ido , Pansky Moty , Schneider David
Published: November 2004

Objective: In order to better understand the etiology of the vulvar vestibulitis syndrome, we examined the histopathologic parameters in vestibular mucosa, and compared the findings in specimens obtained from women with vulvar vestibulitis with those obtained from the control group. Study Design: Specimens of vestibulitis were obtained from 24 patients, undergoing circumferential vestibulectomy under general anesthesia due to the symptoms and signs consistent with vulvar vestibulitis. Control specimens were obtained from 16 women, without symptoms or signs of vulvar vestibulitis, undergoing reconstructive introital surgery due to roomy vagina, rectocele or painful episiotomy. All vestibular tissue specimens were examined for intensity of inflammation, extension of inflammatory cells into the epithelium, vascular proliferation, the presence of mast cells and proliferation of peripheral nerve bundles. Results: No significant difference was found regarding the degree of inflammation, the extension of inflammatory cells into the epithelium, the vascular proliferation and the presence of mast cells while comparing the study and the control groups. The only histopathologic feature, differentiating the patients with vulvar vestibulitis from the control group, was the proliferation of peripheral nerve bundles found in 19 out of 24 (79.1%) specimens expressing vestibulitis and in none of 16 control specimens (p < 0.0001). Conclusion: Our results, therefore, support the existence of peripheral nerve hyperplasia in vestibular tissue obtained from patients with vulvar vestibulitis, and exclude the role of active inflammation or mast cells as probable etiologies for the vulvar vestibulitis syndrome.
Antihypertensive Effect of 5-HT1A Agonist Buspirone and 5-HT2B Antagonists in Experimentally Induced Hypertension in Rats
Authors: Shingala J.R. , Balaraman R.
Published: November 2004

We investigated the antihypertensive effect of 5-HT1A agonist (buspirone) and 5-HT2B antagonists (SB204741 and SB200646) in deoxycorticosterone acetate (DOCA)-salt-induced hypertensive rats. Experiments were divided into two sets: in the first set, sham-operated control and DOCA-treated hypertensive rats received buspirone (1 mg/kg/day p.o. for 4 weeks) and in the second set, in vivo and in vitro studies were carried out. In the case of in vivo studies, sham-operated control and DOCA-treated hypertensive rats received SB204741 or SB200646 (1 mg/kg/week i.v. for 4 weeks). Blood pressure was measured weekly by tail-cuff method. After completion of the treatment schedule, blood pressure and vascular reactivity to various agonists like 5-HT, noradrenaline and adrenaline were recorded. Chronic administration of buspirone, SB204741 and SB200646 produced a significant reduction in blood pressure and vascular reactivity to agonists in DOCA-salt hypertensive rats, implying an antihypertensive effect. However, chronic administration of the same drugs in sham control rats did not alter blood pressure and vascular reactivity to various agonists. For in vitro studies a similar treatment schedule was followed as in vivo studies and a cumulative concentration response curve of 5-HT was recorded on isolated thoracic aorta. Treatment with 5-HT2B antagonists shifted the concentration response curve of 5-HT to the right on isolated aorta. We conclude that 5-HT1A agonist and 5-HT2B antagonists possess an antihypertensive effect.
Mercury, Fish Oils, and Risk of Acute Coronary Events and Cardiovascular Disease, Coronary Heart Disease, and All-Cause Mortality in Men in Eastern Finland
Authors: Virtanen Jyrki K. , Voutilainen Sari , Rissanen Tiina H. , Mursu Jaakko , Tuomainen Tomi-Pekka , Korhonen Maarit J. , Valkonen Veli-Pekka , Seppänen Kari , Laukkanen Jari A. , Salonen Jukka T.
Published: November 2004

Objective—

Mercury has been suggested to have negative effects on cardiovascular health. We investigated the effects of high mercury content in hair on the risk of acute coronary events and cardiovascular and all-cause mortality in men from eastern Finland.

Methods and Results—

The population-based prospective Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD) cohort of 1871 Finnish men aged 42 to 60 years and free of previous coronary heart disease (CHD) or stroke at baseline was used. During an average follow-up time of 13.9 years, 282 acute coronary events and 132 cardiovascular disease (CVD), 91 CHD, and 525 all-cause deaths occurred. Men in the highest third of hair mercury content (>2.03 μg/g) had an adjusted 1.60-fold (95% CI, 1.24 to 2.06) risk of acute coronary event, 1.68-fold (95% CI, 1.15 to 2.44) risk of CVD, 1.56-fold (95% CI, 0.99 to 2.46) risk of CHD, and 1.38-fold (95% CI, 1.15 to 1.66) risk of any death compared with men in the lower two thirds. High mercury content in hair also attenuated the protective effects of high-serum docosahexaenoic acid plus docosapentaenoic acid concentration.

Conclusions—

High content of mercury in hair may be a risk factor for acute coronary events and CVD, CHD, and all-cause mortality in middle-aged eastern Finnish men. Mercury may also attenuate the protective effects of fish on cardiovascular health.
Protein Kinase C Pathway Is Involved in Transcriptional Regulation of C-Reactive Protein Synthesis in Human Hepatocytes
Authors: Ivashchenko Yuri , Kramer Frank , Schäfer Stefan , Bucher Andrea , Veit Kerstin , Hombach Vinzenz , Busch Andreas , Ritzeler Olaf , Dedio Jürgen , Torzewski Jan
Published: November 2004

Objective—C-Reactive protein (CRP) is the prototype acute phase protein and a cardiovascular risk factor. Interleukin-1β (IL-1β) and IL-6 stimulate CRP synthesis in hepatocytes. We searched for additional pathways regulating CRP expression.

Methods and Results—Primary human hepatocytes (PHHs) were treated with IL-1β, IL-6, and protein kinase C (PKC) activator phorbol 12,13-dibutyrate (PDBu). CRP was analyzed by quantitative RT-PCR and ELISA. PDBu significantly induced CRP transcription by 21.0±9.24-fold and protein release by 2.9±0.5-fold. Transcriptional regulation was studied in detail in hepatoma G2 (HepG2) cells stably transfected with the 1-kb CRP promoter (HepG2–ABEK14 cells). In these cells, PDBu significantly induced CRP transcription by 5.39±0.66-fold. Competetive inhibition with bisindolylmaleimide derivative LY333531 abolished PDBu-mediated promoter activation. Competetive inhibition with IκB kinase inhibitor I229 also inhibited PDBu effects. Importantly, IL-8 significantly induced CRP release in PHHs by 58.675±19.1-fold, which was blockable by LY333531.

Conclusions—This study describes a novel PKC-dependent transcriptional regulation of CRP gene expression, which, in analogy to the classical IL-1β and IL-6 pathways, is operational in hepatocytes only. It also identifies IL-8 as a potential physiological PKC activator. HepG2–ABEK14 cells may be useful for high throughput screening to identify inhibitors of CRP synthesis for the prevention of cardiovascular disease.
Role of ADAMTS-1 in Atherosclerosis
Authors: Jönsson-Rylander Ann-Cathrine , Nilsson Tina , Fritsche-Danielson Regina , Hammarström Anette , Behrendt Margareta , Andersson Jan-Olof , Lindgren Kerstin , Andersson Ann-Katrin , Wallbrandt Pia , Rosengren Birgitta , Brodin Peter , Thelin Anders , Westin Annika , Hurt-Camejo Eva , Lee-Søgaard Chung-Hyun
Published: November 2004

Objective—

We investigated the potential role of ADAMTS-1 (a disintegrin and metalloprotease with thrombospondin motif type I) in atherogenesis.

Methods and Results—

ADAMTS-1 is expressed at the highest levels in the aorta when compared with other human tissues examined. Immunolocalization studies in human aorta and coronary artery indicate that ADAMTS-1 expression is mainly seen at low levels in the medial layer, but upregulated in the intima when plaque is present. We found that ADAMTS-1 mRNA levels are significantly higher in proliferating/migrating cultured primary aortic vascular smooth muscle cells (VSMCs) compared with resting/confluent cells. Using the mouse carotid artery flow cessation model, we show that there are differences in vessel remodeling in ADAMTS-1 transgenic/apoE-deficient mice compared with apoE deficiency alone, particularly a significant increase in intimal hyperplasia. We show that ADAMTS-1 can cleave the large versican containing proteoglycan population purified from cultured human aortic VSMCs. Finally, using versican peptide substrates, we show data suggesting that ADAMTS-1 cleaves versican at multiple sites.

Conclusion—

We hypothesize that ADAMTS-1 may promote atherogenesis by cleaving extracellular matrix proteins such as versican and promoting VSMC migration.
Regulation of Transport of the Angiotensin AT2 Receptor by a Novel Membrane-Associated Golgi Protein
Authors: Wruck Christoph J. , Funke-Kaiser Heiko , Pufe Thomas , Kusserow Heike , Menk Mario , Schefe Jan H. , Kruse Marie L. , Stoll Monika , Unger Thomas
Published: November 2004

Objective—

Synthesis and maturation of G protein–coupled receptors are complex events that require an intricate combination of processes including protein folding, posttranslational modifications, and transport through distinct cellular compartments. Little is known concerning the regulation of G protein–coupled receptor transport from the endoplasmic reticulum to the cell surface.

Methods and Results—

Here we show that the cytoplasmatic carboxy-terminal of the angiotensin AT2 receptor (AT2R) acts independently as an endoplasmic reticulum–export signal. Using a yeast two-hybrid system, we identified a Golgi membrane–associated protein termed ATBP50 (for AT2R binding protein of 50 kDa) that binds to this motif. We also cloned ATBP60 and ATBP135 encoded by the same gene as ATBP50 that mapped to chromosomes 8p21.3. Downregulation of ATBP50 using siRNA leads to retention of AT2R in inner compartments, reduced cell surface expression, and decreased antiproliferative effects of the receptor.

Conclusion—

Our results indicate that ATBP50 regulates the transport of the AT2R to cell membrane by binding to a specific motif within its cytoplasmic carboxy-terminal and thereby enabling the antiproliferative effects of the receptor.
Peroxisome Proliferator–Activated Receptor α Induces NADPH Oxidase Activity in Macrophages, Leading to the Generation of LDL with PPAR-α Activation Properties
Authors: Teissier Elisabeth , Nohara Atsushi , Chinetti Giulia , Paumelle Réjane , Cariou Bertrand , Fruchart Jean-Charles , Brandes Ralf P. , Shah Ajay , Staels Bart
Published: November 2004

Peroxisome proliferator–activated receptors (PPARs) are nuclear receptors controlling lipid and glucose metabolism as well as inflammation. PPARs are expressed in macrophages, cells that also generate reactive oxygen species (ROS). In this study, we investigated whether PPARs regulate ROS production in macrophages. Different PPAR-α, but not PPAR-γ agonists, increased the production of ROS (H
2
O
2
and

) in human and murine macrophages. PPAR-α activation did not induce cellular toxicity, but significantly decreased intracellular glutathione levels. The increase in ROS production was not attributable to inherent prooxidant effects of the PPAR-α agonists tested, but was mediated by PPAR-α, because the effects were lost in bone marrow–derived macrophages from PPAR-α
−/−
mice. The PPAR-α–induced increase in ROS was attributable to the induction of NADPH oxidase, because (1) preincubation with the NADPH oxidase inhibitor diphenyleneiodinium prevented the increase in ROS production; (2) PPAR-α agonists increased

production measured by superoxide dismutase–inhibitable cytochrome c reduction; (3) PPAR-α agonists induced mRNA levels of the NADPH oxidase subunits p47
phox
, p67
phox
, and gp91
phox
and membrane p47
phox
protein levels; and (4) induction of ROS production was abolished in p47
phox−/−
and gp91
phox−/−
macrophages. Finally, induction of NADPH oxidase by PPAR-α agonists resulted in the formation of oxidized LDL metabolites that exert PPAR-α–independent proinflammatory and PPAR-α–dependent decrease of lipopolysaccharide-induced inducible nitric oxide synthase expression in macrophages. These data identify a novel mechanism of autogeneration of endogenous PPAR-α ligands via stimulation of NADPH oxidase activity.
Rain Enhancement and Fog Elimination by Seeding with Charged Droplets. Part I: Theory and Numerical Simulations
Authors: Khain A. , Arkhipov V. , Pinsky M. , Feldman Y. , Ryabov Ya
Published: November 2004

A new method of droplet collision acceleration, with the purpose of rain enhancement and fog elimination, is proposed. According to the method, some fraction of the droplets is taken from clouds (or fog) themselves, charged, and then injected back into clouds (or fog). To verify the efficiency of the method, a novel model has been developed, allowing simulation of droplet spectrum evolution by collision in case a certain fraction of the droplets in a droplet spectrum is charged. Simulations of droplet spectra evolution include several steps: (a) The forces arising between charged and neutral droplets, as well as between charged droplets, are calculated as the function of the value of the charges, droplet size, and distance between droplets. It is shown that because of the induction effect, significant attraction forces arise between charged and neutral droplets. (b) The results obtained have been used to calculate the collision efficiencies between charged and neutral, as well between charged droplets. As a result, a “four dimensional” table of the collision efficiencies (the collision efficiency is the function of the droplet size and charge) was calculated. The collision efficiencies between charged and neutral droplets turn out to be significantly higher than the pure gravity-induced values. (c) To accomplish these simulations, a novel numerical method of solving the stochastic collision equation has been developed. Cloud droplets are described by a two-dimensional size distribution function in which droplets are characterized by both their mass and charge. (d) This model, with the implemented table of the collision efficiencies, has been used to simulate droplet spectra evolution in clouds and fog in case some fraction of these droplets was charged. Simulations of the effects of seeding by charged droplets have been performed. Evolution of initially narrow droplet size spectra (typical of extremely continental clouds in highly smoky air), in the case of seeding and under natural conditions, has been simulated. It was shown that although a natural droplet spectrum does not develop and no raindrops are formed, the injection of just a small fraction of charged particles rapidly triggered the collision process and lead to raindrop formation a few minutes after the injection. Significant acceleration of raindrop formation has been found in the case of a maritime wide-droplet spectrum. Simulations of fog seeding were conducted using droplet spectra distributions of typical fog. Seeding by charged fog droplets of one or both polarities was simulated. In both cases a significant increase in fog visibility was found. The advantages of the seeding method proposed are discussed.
Turbulent Transfer Coefficients and Calculation of Air Temperature inside Tall Grass Canopies in Land–Atmosphere Schemes for Environmental Modeling
Authors: Mihailovic D. T. , Alapaty K. , Lalic B. , Arsenic I. , Rajkovic B. , Malinovic S.
Published: November 2004

A method for estimating profiles of turbulent transfer coefficients inside a vegetation canopy and their use in calculating the air temperature inside tall grass canopies in land surface schemes for environmental modeling is presented. The proposed method, based on K theory, is assessed using data measured in a maize canopy. The air temperature inside the canopy is determined diagnostically by a method based on detailed consideration of 1) calculations of turbulent fluxes, 2) the shape of the wind and turbulent transfer coefficient profiles, and 3) calculation of the aerodynamic resistances inside tall grass canopies. An expression for calculating the turbulent transfer coefficient inside sparse tall grass canopies is also suggested, including modification of the corresponding equation for the wind profile inside the canopy. The proposed calculations of K-theory parameters are tested using the Land–Air Parameterization Scheme (LAPS). Model outputs of air temperature inside the canopy for 8–17 July 2002 are compared with micrometeorological measurements inside a sunflower field at the Rimski Sancevi experimental site (Serbia). To demonstrate how changes in the specification of canopy density affect the simulation of air temperature inside tall grass canopies and, thus, alter the growth of PBL height, numerical experiments are performed with LAPS coupled with a one-dimensional PBL model over a sunflower field. To examine how the turbulent transfer coefficient inside tall grass canopies over a large domain represents the influence of the underlying surface on the air layer above, sensitivity tests are performed using a coupled system consisting of the NCEP Nonhydrostatic Mesoscale Model and LAPS.
Oblique, Stratified Winds about a Shelter Fence. Part II: Comparison of Measurements with Numerical Models
Authors: Wilson John D.
Published: November 2004

To evaluate Reynolds-averaged Navier–Stokes (RANS) models of disturbed micrometeorological winds, steady-state computations using a second-order closure are compared with observations (see Part I) in which the surface layer wind was disturbed by a long, thin porous fence (height h = 1.25 m; thickness dx ≈ 1 mm). Starting with the case of neutral stratification and normal incidence, it is shown that low-resolution RANS simulations (streamwise grid interval Δx/h = 1) produce reasonably good transects of mean wind speed, though with an ambiguity (or nonuniqueness) of at least 10%–15% of the amplitude of the relative wind curve, mainly arising from sensitivity to the choice of the solution mesh. For nearly perpendicular flows, the measured influence of stratification (stable or unstable) is to diminish the amplitude of the relative wind curve (i.e., windbreak is less effective), an effect that is replicated very well by the simulations. Obliquity of the incident wind, like stratification, also correlates with poorer shelter, but the computed response of the relative wind curve to obliquity is excessive. As for higher-order wind statistics, computed transects of velocity standard deviations compare poorly to those observed. Therefore, if this disturbed flow may be taken as representative, then caution must be recommended should it be thought that RANS-type models might be suitable (i.e., accurate, as well as convenient) for computing the disturbed wind statistics (typically mean velocity, shear stress tensor, and turbulent kinetic energy dissipation rate) that are needed to “drive” modern dispersion models in the complex wind regimes that must be confronted in such contexts as urban dispersion, or the wind migration of pollen.
Results of Sun Photometer–Derived Precipitable Water Content over a Tropical Indian Station
Authors: Ernest Raj P. , Devara P. C. S. , Maheskumar R. S. , Pandithurai G. , Dani K. K. , Saha S. K. , Sonbawne S. M. , Tiwari Y. K.
Published: November 2004

A compact, hand-held multiband sun photometer (ozone monitor) has been used to measure total precipitable water content (PWC) at the low-latitude tropical station in Pune, India (18°32′N, 73°51′E). Data collected in the daytime (0730–1800 LT) during the period from May 1998 to September 2001 have been used here. The daytime average PWC value at this station is 1.13 cm, and the average for only the clear-sky days is 0.75 cm. PWC values between 0.75 and 1.0 cm have the maximum frequency of occurrence. There is a large day-to-day variability due to varied sky and meteorological conditions. Mainly two types of diurnal variations in PWC are observed. The one occurs in the premonsoon summer months of April and May and shows that forenoon values are smaller than afternoon values. The other type occurs in November and December and shows a minimum around noontime. There is a diurnal asymmetry in PWC in which, on the majority of the days, the mean afternoon value is greater than the forenoon value. This asymmetry is more pronounced in the summer and southwest monsoon months (i.e., March–June). Monthly mean PWC is highest in September and lowest in December. The increase in PWC from the winter (December–February) to summer (March–May) seasons is about 50% and from the summer to southwest monsoon seasons (June–September) is almost 98%. Sun photometer–derived PWC shows a fairly good relationship with surface relative humidity and radiosonde-derived PWC, with a correlation coefficient as high as 0.80.
The Diurnal Cycle of Convection and Atmospheric Tides in an Aquaplanet GCM
Authors: Woolnough S. J. , Slingo J. M. , Hoskins B. J.
Published: November 2004

The diurnal cycle of tropical convection and its relationship to the atmospheric tides is investigated using an aquaplanet GCM.

The diurnal and semidiurnal harmonics of precipitation are both found to contribute significantly to the total diurnal variability of precipitation in the model, which is broadly consistent with observations of the diurnal cycle of convection over the open ocean. The semidiurnal tide is found to be the dominant forcing for the semidiurnal harmonic of precipitation. In contrast the diurnal tide plays only a small role in forcing the diurnal harmonic of precipitation, which is dominated by the variations in shortwave and longwave heating. In both the diurnal and semidiurnal harmonics, the feedback onto the convection by the humidity tendencies due to the convection is found to be important in determining the phase of the harmonics. Further experiments show that the diurnal cycle of precipitation is sensitive to the choice of closure in the convection scheme.

While the surface pressure signal of the simulated atmospheric tides in the model agree well with both theory and observations in their magnitude and phase, sensitivity experiments suggest that the role of the stratospheric ozone in forcing the semidiurnal tide is much reduced compared to theoretical predictions. Furthermore, the influence of the cloud radiative effects seems small. It is suggested that the radiative heating profile in the troposphere, associated primarily with the water vapor distribution, is more important than previously thought for driving the semidiurnal tide. However, this result may be sensitive to the vertical resolution and extent of the model.
Dryline Bulge Evolution in a Two-Dimensional Mixed-Layer Model
Authors: Auslander Glenn M. , Bannon Peter R.
Published: November 2004

This study examines the diurnal response of a mixed-layer model of the dryline system to localized anomalies of surface heat flux, topography, mixed-layer depth, and inversion strength. The two-dimensional, mixed-layer model is used to simulate the dynamics of a cool, moist layer east of the dryline capped by an inversion under synoptically quiescent conditions. The modeled domain simulates the sloping topography of the U.S. Great Plains. The importance of this study can be related to dryline bulges that are areas with enhanced convergence that may trigger convection in suitable environmental conditions.

All anomalies are represented by a Gaussian function in the horizontal whose amplitude, size, and orientation can be altered. A positive, surface-heat-flux anomaly produces increased mixing that creates a bulge toward the east, while a negative anomaly produces a westward bulge. Anomalies in topography show a similar trend in bulge direction with a peak giving an eastward bulge, and a valley giving a westward bulge. Anomalies in the initial mixed-layer depth yield an eastward bulge in the presence of a minimum and a westward bulge for a maximum. An anomaly in the initial inversion strength results in a westward bulge when the inversion is stronger, and an eastward bulge when the inversion is weak. The bulges observed in this study at 1800 LT ranged from 400 to 600 km along the dryline and from 25 to 80 km across the dryline.

When the heating ceases at night, the entrainment and eastward movement of the line stops, and the line surges westward. This westward surge at night has little dependence on the type of anomaly applied. Whether a westward or eastward bulge was present at 1800 LT, the surge travels an equal distance toward the west. However, the inclusion of weak nocturnal friction reduces the westward surge by 100 to 200 km due to mechanical mixing of the very shallow leading edge of the surge.

All model runs exhibit peaks in the mixed-layer depth along the dryline at 1800 LT caused by enhanced boundary layer convergence and entrainment of elevated mixed-layer air into the mixed layer. These peaks appear along the section of the dryline that is least parallel to the southerly flow. They vary in amplitude from 4 to 9 km depending on the amplitude of the anomaly. However, the surface-heat-flux anomalies generally result in peaks at the higher end of this interval. It is hypothesized that the formation of these peaks may be the trigger for deep convection along the dryline in the late afternoon.
Are the Northern Hemisphere Winter Storm Tracks Significantly Correlated?
Authors: Chang Edmund K. M.
Published: November 2004

In this study, the correlation between the Northern Hemisphere winter Pacific and Atlantic storm tracks is examined using the NCEP–NCAR reanalysis and the 40-yr ECMWF Re-Analysis (ERA-40), as well as unassimilated aircraft observations. By examining month-to-month variability in the 250-hPa meridional velocity variance, the correlation between the two storm track peaks is found to be as high as 0.5 during the winters between 1975/76 and 1998/99. Here, it is shown that the correlation between the two storm tracks can be clearly detected from the aircraft data. Further analyses of the reanalysis data show that the correlation can also be seen in other eddy variance and covariance statistics, including the poleward heat flux at the 700-hPa level.

The correlation between the two storm tracks, as seen in both reanalysis datasets, is shown to be much weaker during the period 1957/58–1971/72, suggesting a possible regime transition from largely uncorrelated storm tracks to highly correlated storm tracks during the 1970s. However, during this earlier period, the number of aircraft observations is insufficient to verify the low correlation seen in the reanalyses. Thus, low biases in the reanalyses during the earlier period cannot be ruled out.

An ensemble of four GCM simulations performed using the GFDL GCM forced by global observed SST variations between 1950 and 1995 has also been examined. The correlation between the two storm tracks in the GCM simulations is much lower (0.18) than that observed, even if the analysis is restricted to the GCM simulations from the period 1975/76–1994/95. A Monte Carlo test shows that the observed correlation and the GCM correlation are statistically distinct at the 1% level.

Correlations between the Southern Hemisphere summer Pacific and Atlantic storm tracks have also been examined based on the reanalyses datasets. The results suggest that the amplitude of the SH summer Pacific and Atlantic storm tracks are not significantly correlated, showing that seeding of the Atlantic storm track by the Pacific storm track does not necessarily lead to significant correlations between the two storm tracks.
Biennial and Lower-Frequency Variability Observed in the Early Summer Climate in the Western North Pacific
Authors: Tomita Tomohiko , Yoshikane Takao , Yasunari Tetsuzo
Published: November 2004

Early summer climate in the western North Pacific is largely represented by the baiu phenomenon. The meridional fluctuations of the baiu front on interannual time scales and the associated large-scale circulations are examined using the empirical orthogonal function (EOF) analysis and composite or correlation analyses based on the EOF time coefficients.

The first EOF mode indicates a 5- or 6-yr low-frequency fluctuation (LF mode) appearing south of 35°N. The development is concurrent with horseshoe sea surface temperature anomalies (SSTAs) in the entire tropical Pacific that are associated with the El Niño–Southern Oscillation (ENSO). SSTAs in the western North Pacific control the anomalous southward expansion of the baiu front through a modification of the convection at around 20°–35°N. The LF mode is negatively correlated with the south-southeast Asian summer monsoon.

The second EOF mode is characterized by a meridional seesawlike fluctuation with a node at around 28°N and a time scale of biennial oscillation (BO mode). The horseshoe SSTAs again control the anomalous meridional circulations, but with a different spatial phase through a convection off the Philippines. The spatial phase difference between the two horseshoe patterns is about 90° in both the zonal and meridional directions. The BO mode is negatively correlated with the tropical western North Pacific monsoon.

SSTAs associated with the BO mode tend to be confined to the tropical western Pacific, while the signals of the LF mode extend rather broadly in the tropical Pacific–Indian Ocean sector, suggesting that the tropical BO is an aborted ENSO in the tropical central–western Pacific. The spatial phase of horseshoe SSTAs adjusts the interannual variability of the meridional fluctuation of the baiu front in the western North Pacific.
Numerically Converged Solutions of the Global Primitive Equations for Testing the Dynamical Core of Atmospheric GCMs
Authors: Polvani L. M. , Scott R. K. , Thomas S. J.
Published: November 2004

Solutions of the dry, adiabatic, primitive equations are computed, for the first time, to numerical convergence. These solutions consist of the short-time evolution of a slightly perturbed, baroclinically unstable, midlatitude jet, initially similar to the archetypal LC1 case of Thorncroft et al. The solutions are computed with two distinct numerical schemes to demonstrate that they are not dependent on the method used to obtain them.

These solutions are used to propose a new test case for dynamical cores of atmospheric general circulation models. Instantaneous horizontal and vertical cross sections of vorticity and vertical velocity after 12 days, together with tables of key diagnostic quantities derived from the new solutions, are offered as reproducible benchmarks. Unlike the Held and Suarez benchmark, the partial differential equations and the initial conditions are here completely specified, and the new test case requires only 12 days of integration, involves no spatial or temporal averaging, and does not call for physical parameterizations to be added to the dynamical core itself.