bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Diabetes Mellitus on the Outcome of Patients with Resected Non-Small Cell Lung Carcinoma
Authors: Bartling Babett , Simm Andreas , Sohst Antonia , Silber Rolf-Edgar , Hofmann Hans-Stefan
Published: March 2011

Background: Both diabetes mellitus (DM) and non-small cell lung carcinoma (NSCLC) are age-related diseases and therefore occur simultaneously. DM and, in particular, diabetic nephropathy are associated with an increased modification of the extracellular tissue matrix with advanced glycation end-products (AGEs). Objective: As AGE-modified matrix impairs the invasive migration of lung carcinoma cells, our study aimed at the effect of DM on the NSCLC-related outcome. Methods:In a retrospective clinical study, we analyzed the time-dependent survival of NSCLC patients with DM compared to patients without DM, who had been treated for cancer by resection surgery. The age-matched study population (51–80 years) included 55 DM patients and 111 non-DM patients. Results: Comparative analyses between DM and non-DM patients did not find significant differences for NSCLC histology, tumor stage and stay in the hospital. Analyses of the mid-term (20-month) survival showed that the DM group had a significantly higher proportion of NSCLC patients being alive 20 months after tumor resection than the non-DM group (76 vs. 59%, p = 0.048). The DM-related increase in the mid-term survival rate was particularly observed for patients without lymph node metastasis (88%) and those patients also suffering from nephropathy (90%). In contrast to the mid-term survival, DM had no effect on the long-term (60-month) survival of NSCLC patients (35 vs. 32% in the non-DM group). Conclusion: Our study indicates that DM-associated changes mediate beneficial effects in terms of NSCLC progression, in which AGE modifications might play a critical role.
The Bidirectional Crosstalk between Human Dendritic Cells and Natural Killer Cells
Authors: Wehner Rebekka , Dietze Kristin , Bachmann Michael , Schmitz Marc
Published: March 2011

Dendritic cells (DCs) are professional antigen-presenting cells, which display an extraordinary capacity to induce T-cell responses. Recent findings revealed that DCs also play a crucial role in the activation of natural killer (NK) cells representing important effectors in the innate immune defense against viruses and tumors. Here, we summarize various studies investigating the bidirectional crosstalk between human DCs and NK cells. In this context, it has been reported that DCs efficiently enhance CD69 expression, proliferation, interferon (IFN)-γ secretion and cytotoxic activity of NK cells. Cell membrane-associated molecules as well as soluble factors such as interleukin-12, tumor necrosis factor-α and type I IFNs contributed to DC-mediated NK cell activation. Reciprocally, the ability of human NK cells to enhance the immunostimulatory capacity of DCs was shown. Thus, NK cells promoted the maturation of DCs and markedly augmented their capacity to produce proinflammatory cytokines and to stimulate T-cell responses. The NK cell-mediated effects on DCs were dependent on cell membrane-associated molecules such as NKp30 and soluble factors such as tumor necrosis factor-α and IFN-γ. In conclusion, the reciprocal activating interaction between human DCs and NK cells may play a pivotal role in the immune defense against viruses and tumors.
Role of Natural Killer Cells in Hematopoietic Stem Cell Transplantation: Myth or Reality?
Authors: Nguyen Stéphanie , Béziat Vivien , Roos-Weil Damien , Vieillard Vincent
Published: March 2011

Natural killer (NK) cells play a crucial role in the innate immune system and are responsible for the initial responses in the surveillance against malignant cells and virally infected cells. NK cells express their own repertoire of receptors, including activating and inhibitory receptors, which bind to major histocompatibility complex class I or class-I-related molecules. Binding of NK cell inhibitory receptors to their major histocompatibility complex class I ligands protects the target cells from NK cell-mediated cytotoxicity. NK cell alloreactivity has been put to use in allogeneic hematopoietic stem cell transplantation to reduce the rate of relapse and of graft-versus-host disease. A variety of findings have been observed in clinical studies, showing either beneficial or deleterious effects on clinical outcome. This article reviews the results of major clinical trials in relation to the model used to define NK cell alloreactivity.
Modulation of Natural Killer Cell Anti-Tumor Reactivity by Platelets
Authors: Placke Theresa , Kopp Hans-Georg , Salih Helmut Rainer
Published: March 2011

Natural killer (NK) cells may prevent tumor progression and metastasis. Apart from the direct interaction with their targets, NK cell activity is influenced by the reciprocal interplay with other hematopoietic cells. While the interaction of NK cells e.g. with dendritic cells or monocytes/macrophages is well characterized, knowledge regarding their crosstalk with platelets, another central component of the blood, is still fragmentary. However, studies in mice and men clearly document a strong dependence of tumor progression and metastasis on quantitatively and functionally normal platelets. In mice, metastasis is inhibited by thrombocytopenia, and this effect is reversed by additional NK cell depletion, indicating that platelets may ‘indirectly’ contribute to tumor dissemination by impairing NK cell anti-tumor reactivity. In humans, circumstantial evidence indicates that metastasizing malignant cells do not travel through the blood alone, but efficiently attract and get coated by platelets, thereby causing release of platelet granule content. Beyond this secretion of various growth factors and cytokines/chemokines, platelets may also influence NK cell function by immunoregulatory molecules expressed on the platelet surface. Here, we review the available data regarding tumor-platelet-NK cell interaction focusing on metastatic tumor spread and discuss the molecular mechanisms underlying this trilateral crosstalk.
Unplanned Staged Hybrid Management of Postmyocardial Infarction Ventricular Septal Defect
Authors: Avgerinos Dimitrios V. , Feldman Dmitriy N. , Salemi Arash
Published: March 2011

Ventricular septal defect (VSD) is an uncommon but potentially deadly complication of transmural myocardial infarction (MI). Emergency surgical treatment has traditionally offered the best chance for survival. However, operative intervention is associated with high mortality and can be complicated by a recurrent VSD due to tissue friability around the infarcted area. Percutaneous catheter-based closure techniques can be used to treat these critically ill patients, offering a less invasive and less morbid technique. This case demonstrates the successful application of an unplanned, staged hybrid approach utilizing initial percutaneous and subsequent surgical repair after recovery of tissue integrity.
The Impossible Succession of Charcot – The Quest for a Suitable Heir
Authors: Tatu Laurent , Bogousslavsky Julien
Published: March 2011

With the death of Jean-Martin Charcot (1825–1893) in 1893 came the impossible task of finding a suitable successor. The clinical chair for nervous system diseases was temporarily entrusted to Édouard Brissaud (1852–1909). There were a number of potential successors, but only three were officially declared: Brissaud, Jules Déjerine (1849–1917) and Fulgence Raymond (1844–1910). In the final vote, Raymond was appointed as Charcot’s successor. Although this succession would prove too great a challenge for him, Raymond’s work in neurology, which is often unrecognised, made him one of the most important French neurologists of the early 20th century.
FP-CIT SPECT Does Not Predict the Progression of Motor Symptoms in Parkinson’s Disease
Authors: Hubbuch Magdalena , Farmakis Georgios , Schaefer Andrea , Behnke Stefanie , Schneider Susanne , Hellwig Dirk , Fassbender Klaus , Kirsch Carl-Martin , Dillmann Ulrich , Spiegel Joerg
Published: March 2011

Background/Aims: FP-CIT (fluoropropyl-2β-carbomethoxy-3β-4-iodophenyl-nortroptane) SPECT is a well-established nuclear medicine method to support the clinical diagnosis of Parkinson’s disease (PD). In this study, we examined the prognostic value of FP-CIT SPECT concerning the PD motor symptoms. Methods: All 38 PD patients (age 57 ± 7 years, Hoehn & Yahr stage 1.6 ± 0.8, mean ± SD) underwent a baseline visit and a follow-up visit 3–7 years (5.2 ± 1.3 years) after the baseline visit. Cerebral [123I]FP-CIT SPECT was performed only once at the baseline visit. At both visits the motor symptoms bradykinesia, rigidity, resting tremor, postural tremor and axial symptoms were quantified by means of the UPDRS motor scale. Results: There was no significant correlation between the initial striatal FP-CIT uptake and the annual progress of any motor symptom (= difference [(motor symptom at follow-up visit) – (motor symptom at baseline visit)]/time (in years) between assessments). Conclusion: The initial striatal FP-CIT SPECT does not predict the velocity of progress of PD motor symptoms within an interval of 3–7 years.
Renal Function Improvement with Pentavalent Antimonial Agents in Patients with Visceral Leishmaniasis
Authors: Daher Elizabeth F. , Rocha Natália A. , Oliveira Michelle J.C. , Franco Luiz F.L.G. , Oliveira Jobson L. , Silva Junior Geraldo B. , Abreu Krasnalhia Lívia S. , Henn Guilherme A.L. , Martins Alice M.C. , Libório Alexandre B.
Published: March 2011

Background: The aim of this study is to investigate tubular and glomerular function after visceral leishmaniasis (VL) treatment with pentavalent antimonials. Methods: This is a prospective study including 14 patients with VL diagnosis treated with pentavalent antimonials. Urine acidification and concentration tests were performed. Estimated glomerular filtration rate (eGFR), fractional excretion of sodium (FENa) and potassium (FEK) and free water clearance (CH2O) were measured to assess glomerular and tubular function. Results: The VL group had a significantly lower FEK, serum sodium and plasma osmolality (Posm). No significant differences were found regarding proteinuria, eGFR, FENa or CH2O. Patients in the VL group had lower urinary osmolality (Uosm) before DDAVP use when compared to the control group, as well as a lower U/Posm. The urinary pH before and after CaCl2 load was higher in the VL group. Conclusion: This study shows evidence of reversal of some tubular dysfunction in VL, but other dysfunctions may persist, especially urinary acidification capacity.
Stromal Vascular Fraction From Adipose Tissue Forms Profound Vascular Network Through the Dynamic Reassembly of Blood Endothelial Cells
Authors: Koh Young Jun , Koh Bong Ihn , Kim Honsoul , Joo Hyung Joon , Jin Ho Kyoung , Jeon Jongwook , Choi Chulhee , Lee Dong Hun , Chung Jin Ho , Cho Chung-Hyun , Park Won Seok , Ryu Ji-Kan , Suh Jun Kyu , Koh Gou Young
Published: March 2011

Objective—

Tremendous efforts have been made to establish effective therapeutic neovascularization using adipose tissue-derived stromal vascular fraction (SVF), but the efficiency is low, and underlying mechanisms and their interaction with the host in a new microenvironment are poorly understood.

Methods and Results—

Here we demonstrate that direct implantation of SVF derived from donor adipose tissue can create a profound vascular network through the disassembly and reassembly of blood endothelial cells at the site of implantation. This neovasculature successfully established connection with recipient blood vessels to form a functionally perfused circuit. Addition of vascular growth factors to the SVF implant improved the efficiency of functional neovasculature formation. In contrast, spheroid culture of SVF before implantation reduced the capacity of vasculature formation, possibly because of cellular alteration. Implanting SVF into the mouse ischemic hindlimb induced the robust formation of a local neovascular network and salvaged the limb. Moreover, the coimplantation of SVF prevented fat absorption in the subcutaneous adipose tissue graft model.

Conclusion—

Freshly isolated SVF can effectively induce new vessel formation through the dynamic reassembly of blood endothelial cells and could be applied to achieve therapeutic neovascularization for relieving ischemia and preventing fat absorption in an autologous manner.
Pyripyropene A, an Acyl–Coenzyme A:Cholesterol Acyltransferase 2–Selective Inhibitor, Attenuates Hypercholesterolemia and Atherosclerosis in Murine Models of Hyperlipidemia
Authors: Ohshiro Taichi , Matsuda Daisuke , Sakai Kent , Degirolamo Chiara , Yagyu Hiroaki , Rudel Lawrence L. , Ōmura Satoshi , Ishibashi Shun , Tomoda Hiroshi
Published: March 2011

Objective—

Pyripyropene A (PPPA) of fungal origin is the first compound that has been found to strongly and selectively inhibit acyl–coenzyme A:cholesterol acyltransferase 2 (ACAT2) isozyme activity in vitro. The purpose of the present study was to investigate in vivo efficacy of the ACAT2-selective inhibitor in atherosclerosis.

Methods and Results—

PPPA treatment (10 to 100 mg/kg) caused 30.5±4.7% to 55.8±3.3% inhibition of the cholesterol absorption from the mouse intestine. When PPPA (10 to 50 mg/kg per day) was orally administered to apolipoprotein E–knockout mice for 12 weeks, the levels of plasma cholesterol, very-low-density lipoprotein (VLDL), and low-density lipoprotein (LDL) and hepatic cholesterol content were lowered. Furthermore, the ratio of cholesteryl oleate (exclusively synthesized in hepatic ACAT2) to cholesteryl linoleate in VLDL- and LDL-derived cholesteryl ester decreased, indicating that hepatic ACAT2 activity was inhibited by PPPA. PPPA-treated mice had reduced atherogenic lesion areas that were lowered by 26.2±3.7% to 46±3.8% in the aortae and by 18.9±3.6% to 37.6±6.0% in the hearts.

Conclusion—

Our findings indicate that ACAT2-selective inhibition in the intestine and the liver can be effective against atherosclerosis and that PPPA appears to be a potential antiatherogenic lead compound. This study is the first demonstration of the in vivo efficacy of PPPA, an ACAT2-selective inhibitor, in atherosclerosis. PPPA-treated atherogenic mice showed a decrease in intestinal cholesterol absorption and cholesterol and cholesteryl oleate levels in both LDL and VLDL, resulting in protection of atherosclerosis development.
Evidence of How rs7575840 Influences Apolipoprotein B–Containing Lipid Particles
Authors: Haas Blake E. , Weissglas-Volkov Daphna , Aguilar-Salinas Carlos A. , Nikkola Elina , Vergnes Laurent , Cruz-Bautista Ivette , Riba Laura , Stancakova Alena , Kuusisto Johanna , Soininen Pasi , Kangas Antti J. , Ala-Korpela Mika , Tusie-Luna Teresa , Laakso Markku , Pajukanta Päivi
Published: March 2011

Objective—

Recent genome-wide association studies identified a variant rs7575840 in the apolipoprotein B (APOB) gene region as associated with low-density lipoprotein (LDL) cholesterol. However, the underlying functional mechanism of this variant, which resides 6.5 kb upstream of APOB, has remained unknown. Our objective was to investigate rs7575840 for association with refined apoB-containing lipid particles, for replication in a Mexican population, and for its underlying functional mechanism.

Methods and Results—

Our data show that rs7575840 is associated with serum apoB levels (
P
=4.85×10
−10
) and apoB-containing lipid particles, very small very-low-density lipoprotein, intermediate lipoprotein, and LDL particles (
P
=2×10
−5
to 9×10
−7
) in the Finnish Metabolic Syndrome in Men study sample (n=7710). Fine mapping of the APOB region using 43 single-nucleotide polymorphisms replicated the association of rs7575840 with apoB in a Mexican study sample (n=2666,
P
=3.33×10
−5
). Furthermore, our transcript analyses of adipose RNA samples from 175 subjects in the Finnish Metabolic Syndrome in Men study indicate that rs7575840 alters expression of APOB (
P
=1.13×10
−10
) and a regional noncoding RNA (BU630349) (
P
=7.86×10
−6
) in adipose tissue.

Conclusion—

It has been difficult to convert genome-wide association study associations into mechanistic insights. Our data show that rs7575840 is associated with serum apoB levels and apoB-containing lipid particles, as well as influencing expression of APOB and a regional transcript BU630349 in adipose tissue. We thus provide evidence how a common genome-wide significant single-nucleotide polymorphism, rs7575840, may affect serum apoB, LDL cholesterol, and total cholesterol levels.
Impairment of the Programmed Cell Death-1 Pathway Increases Atherosclerotic Lesion Development and Inflammation
Authors: Bu De-xiu , Tarrio Margarite , Maganto-Garcia Elena , Stavrakis George , Tajima Goro , Lederer James , Jarolim Petr , Freeman Gordon J. , Sharpe Arlene H. , Lichtman Andrew H.
Published: March 2011

Objective—

Programmed cell death-1 (PD-1) is a member of the CD28 superfamily that delivers negative signals on interaction with its 2 ligands, PD-L1 and PD-L2. We studied the contribution of the PD-1 pathway to regulation of T cells that promote atherosclerotic lesion formation and inflammation.

Methods and Results—

We show that compared with
Ldlr
−/−
control mice,
Pd1
−/−
Ldlr
−/−
mice developed larger lesions with more abundant CD4
+
and CD8
+
T cells and macrophages, accompanied by higher levels of serum tumor necrosis factor-α. Iliac lymph node T cells from
Pd1
−/−
Ldlr
−/−
mice proliferated more to αCD3 or oxidized low-density lipoprotein stimulation compared with controls. CD8
+
T cells from
Pd1
−/−
Ldlr
−/−
mice displayed more cytotoxic activity compared with controls in vivo and in vitro. Administration of a blocking anti-PD-1 antibody increased lesional inflammation in hypercholesterolemic
Ldlr
−/−
mice with more lesional T cells and more activated T cells in paraaortic lymph nodes. The changes in lesional T-cell content when PD-1 was absent or blocked were also observed in bone marrow chimeric
Ldlr
−/−
mice lacking PD-L1 and PD-L2 on hematopoietic cells.

Conclusion—

PD-1 has an important role in downregulating proatherogenic T-cell responses, and blockade of this molecule for treatment of viral infections or cancer may increase risk of cardiovascular complications.
Lack of Primary Cilia Primes Shear-Induced Endothelial-to-Mesenchymal Transition
Authors: Egorova Anastasia D. , Khedoe Padmini P.S.J. , Goumans Marie-José T.H. , Yoder Bradley K. , Nauli Surya M. , ten Dijke Peter , Poelmann Robert E. , Hierck Beerend P.
Published: March 2011

Rationale:

Primary cilia are cellular protrusions that serve as mechanosensors for fluid flow. In endothelial cells (ECs), they function by transducing local blood flow information into functional responses, such as nitric oxide production and initiation of gene expression. Cilia are present on ECs in areas of low or disturbed flow and absent in areas of high flow. In the embryonic heart, high-flow regime applies to the endocardial cushion area, and the absence of cilia here coincides with the process of endothelial-to-mesenchymal transition (EndoMT).

Objective:

In this study, we investigated the role of the primary cilium in defining the responses of ECs to fluid shear stress and in EndoMT.

Methods and Results:

Nonciliated mouse embryonic ECs with a mutation in Tg737/Ift88 were used to compare the response to fluid shear stress to that of ciliated ECs. In vitro, nonciliated ECs undergo shear-induced EndoMT, which is accompanied by downregulation of Klf4. This Tgfβ/Alk5-dependent transformation is prevented by blocking Tgfβ signaling, overexpression of Klf4, or rescue of the primary cilium. In the hearts of Tg737

orpk/orpk

embryos, Tgfβ/Alk5 signaling was activated in areas in which ECs would normally be ciliated but now lack cilia because of the mutation. In these areas, ECs show increased Smad2 phosphorylation and expression of α-smooth muscle actin.

Conclusions:

This study demonstrates the central role of primary cilia in rendering ECs prone to shear-induced activation of Tgfβ/Alk5 signaling and EndoMT and thereby provides a functional link between primary cilia and flow-related endothelial performance.
Carotid Plaque and Candidate Genes Related to Inflammation and Endothelial Function in Hispanics From Northern Manhattan
Authors: Gardener Hannah , Beecham Ashley , Cabral Digna , Yanuck Danielle , Slifer Susan , Wang Liyong , Blanton Susan H. , Sacco Ralph L. , Juo Suh-Hang Hank , Rundek Tatjana
Published: March 2011

Background and Purpose—

The genetic influence on carotid atherosclerotic plaque is mostly unknown. This study examines the association between carotid plaque and single nucleotide polymorphisms in selected genes implicated in inflammation and endothelial function.

Methods—

A total of 43 genes (197 single nucleotide polymorphisms) involved in inflammation and endothelial function were interrogated in 287 Dominicans from the Northern Manhattan Study (mean age, 64±7 years; 58% women) who had undergone high-resolution B-mode ultrasound for examination of carotid plaque. Using an additive genetic model, multiple logistic regression analyses were conducted, a within-gene haplotype analysis was performed, and interactions between genes were examined. Results were validated in an independent set of 301 Dominicans.

Results—

Carotid plaque was present in 143 (47%) participants. Nine genes had at least 1 single nucleotide polymorphism associated (
P
≤0.01) with carotid plaque phenotypes:
TNF
,
NOS2A
,
IL6R
,
TNFSF4
,
PPARA
,
IL1A
,
TLR4
,
ITGA2
, and
HABP2
. Single nucleotide polymorphisms
in TNFSF4
,
PPARA
,
TLR4
,
ITGA2
, and
HABP2
were also implicated with the same carotid phenotype in the validation analysis. Haplotype analysis revealed an additional gene of interest,
VCAM1
.

Conclusions—

We report novel associations between variations in 10 genes involved in inflammation and endothelial function and carotid plaque phenotypes in a Dominican sample, with replication for 5 genes in an independent Dominican sample.
Compromise of Brain Tissue Caused by Cortical Venous Reflux of Intracranial Dural Arteriovenous Fistulas
Authors: Sato Kenichi , Shimizu Hiroaki , Fujimura Miki , Inoue Takashi , Matsumoto Yasushi , Tominaga Teiji
Published: March 2011

Background and Purpose—

Cortical venous reflux (CVR) is a high risk factor for aggressive behavior of intracranial dural arteriovenous fistulas (DAVF). The pathological conditions in brain tissue affected by CVR were investigated by diffusion-weighted magnetic resonance imaging.

Methods—

A retrospective review identified 56 patients with DAVFs who underwent diffusion-weighted imaging before treatment. Twenty patients had neurological symptoms corresponding to the brain area affected by CVR (Group I), 21 patients with CVR had no focal brain dysfunctions (Group II), and 15 patients had no CVR (Group III). Apparent diffusion coefficient (ADC) was measured for 11 brain areas predefined based on normal venous drainage patterns in the 56 patients and in 21 normal volunteers. The mean ADC ratio was calculated for each area by dividing the ADC value of patients by that of normal volunteers.

Results—

Areas affected by CVR in Group I showed a mean ADC-to-control ratio of 0.72, which was significantly lower than that of Group II (0.96,
P
<0.01). Follow-up studies demonstrated significantly increased ADC ratios in brain areas affected by CVR after the DAVFs were treated successfully. The mean ADC ratio of an affected area remained low, with persistent symptoms in 1 patient who underwent palliative treatment.

Conclusions—

Decreased ADC was observed in the brain parenchyma affected by CVR and was associated with regional brain dysfunction. Successful treatment of the DAVF increased the ADC toward normal levels. The ADC may be a useful indicator of the severity of CVR.
Angiogenic and Vasoprotective Effects of Adrenomedullin on Prevention of Cognitive Decline After Chronic Cerebral Hypoperfusion in Mice
Authors: Maki Takakuni , Ihara Masafumi , Fujita Youshi , Nambu Takuo , Miyashita Kazutoshi , Yamada Mahito , Washida Kazuo , Nishio Keiko , Ito Hidefumi , Harada Hiroshi , Yokoi Hideki , Arai Hiroshi , Itoh Hiroshi , Nakao Kazuwa , Takahashi Ryosuke , Tomimoto Hidekazu
Published: March 2011

Background and Purpose—

Although subcortical vascular dementia, the major subtype of vascular dementia, is caused by a disruption in white matter integrity after cerebrovascular insufficiency, no therapy has been discovered that will restore cerebral perfusion or functional cerebral vessels. Because adrenomedullin (AM) has been shown to be angiogenic and vasoprotective, the purpose of the study was to investigate whether AM may be used as a putative treatment for subcortical vascular dementia.

Methods—

A model of subcortical vascular dementia was reproduced in mice by placing microcoils bilaterally on the common carotid arteries. Using mice overexpressing circulating AM, we assessed the effect of AM on cerebral perfusion, cerebral angioarchitecture, oxidative stress, white matter change, cognitive function, and brain levels of cAMP, vascular endothelial growth factor, and basic fibroblast growth factor.

Results—

After bilateral common carotid artery stenosis, mice overexpressing circulating AM showed significantly faster cerebral perfusion recovery due to substantial growth of the capillaries, the circle of Willis, and the leptomeningeal anastomoses and reduced oxidative damage in vascular endothelial cells compared with wild-type mice. Vascular changes were preceded by upregulation of cAMP, vascular endothelial growth factor, and basic fibroblast growth factor. White matter damage and working memory deficits induced by bilateral common carotid artery stenosis were subsequently restored in mice overexpressing circulating AM.

Conclusions—

These data indicate that AM promotes arteriogenesis and angiogenesis, inhibits oxidative stress, preserves white matter integrity, and prevents cognitive decline after chronic cerebral hypoperfusion. Thus, AM may serve as a strategy to tackle subcortical vascular dementia.
Coffee Consumption and Risk of Stroke in Women
Authors: Larsson Susanna C. , Virtamo Jarmo , Wolk Alicja
Published: March 2011

Background and Purpose—

Coffee consumption has been inconsistently associated with stroke incidence and mortality in previous studies. We investigated the association between coffee consumption and stroke incidence in the Swedish Mammography Cohort.

Methods—

We prospectively followed of 34 670 women without a history of cardiovascular disease or cancer at baseline in 1997. Coffee consumption was assessed in 1997 using a self-administered questionnaire. Incident stroke cases were ascertained from the Swedish Hospital Discharge Registry.

Results—

During a mean follow-up of 10.4 years, we ascertained 1680 stroke events, including 1310 cerebral infarctions, 154 intracerebral hemorrhages, 79 subarachnoid hemorrhages, and 137 unspecified strokes. After adjustment for other risk factors, coffee consumption was associated with a statistically significant lower risk of total stroke, cerebral infarction, and subarachnoid hemorrhage but not intracerebral hemorrhage. The multivariable relative risks of total stroke across categories of coffee consumption (<1 cup/day, 1 to 2 cups/day, 3 to 4 cups/day, and ≥5 cups/day) were 1.00, 0.78 (95% CI, 0.66 to 0.91), 0.75 (95% CI, 0.64 to 0.88), and 0.77 (95% CI, 0.63 to 0.92, respectively;
P
for trend=0.02). The association between coffee consumption and cerebral infarction was not modified by smoking status, body mass index, history of diabetes or hypertension, or alcohol consumption.

Conclusions—

These findings suggest that low or no coffee consumption is associated with an increased risk of stroke in women.
A Satellite-Based Summer Convective Cloud Frequency Analysis over the Southeastern United States
Authors: Gambill Laci D. , Mecikalski John R.
Published: March 2011

A convective cloud (CC) analysis is performed over the southeastern United States (SEUS) during June, July, and August 2006 and 2007, using data from the Geostationary Operational Environmental Satellite (GOES) visible and infrared sensors as processed by a satellite-based convection cloud mask and initiation algorithm. Six 5–7-day periods are analyzed between the times 1500 and 1900 UTC, representative of summertime conditions in the SEUS. The ~8.7 × 108pixel database contains information on nonprecipitating CCs possessing various satellite-estimated attributes of cloud size, based on whether they meet set thresholds in eight infrared “interest fields.” CCs at ~1 km × 1 km pixel size in the GOES projection are evaluated in comparison with the land cover classes, elevation gradients, and normalized difference vegetation indices (NDVIs) beneath the CCs. The goals are to relate the frequency of occurrence of CCs to land surface properties, attempting to determine which of these three properties are most correlated with CCs. CCs are more likely to form over forests and dense vegetation and over higher gradients in elevation. Although forest cover classes are not the most common over the SEUS, CC occurrence increases disproportionately where steeply sloped topography and forests are coincident across large regions of the SEUS. Also, as NDVI increases, the percentage of CCs per land class also increases. Analysis of landscape heterogeneity (combining local variability in land classes, topography, and NDVI) shows that as it increases CC development is more widespread. Thus, lakes among forests and hilly topography intermingled with agricultural lands appear most conducive to high CC frequency.
LES Analysis of the Aerodynamic Surface Properties for Turbulent Flows over Building Arrays with Various Geometries
Authors: Nakayama Hiromasa , Takemi Tetsuya , Nagai Haruyasu
Published: March 2011

This paper describes aerodynamic roughness properties for turbulent flows over various building arrays that represent realistic urban surface geometries. First, building morphological characteristics such as roughness density λf and building height variability Vh, defined respectively as the ratio of total frontal area of roughness elements to the total surface area and the ratio of standard deviation in building height to the average building height of the study site, were investigated. Next, large-eddy simulations (LESs) of turbulent flows over building arrays were performed with various surface geometries characterized by a wide range of values for both λf and Vh, based on this building morphological analysis. Third, aerodynamic roughness parameters such as roughness length z0 and drag coefficient were evaluated for the central Tokyo area from the values of z0 and Vh using the LES results. The values of z0 and as a function of both λf and Vh were comparable to those found in earlier studies. The values of z0 and evaluated by a conventional method using only λf were underestimated, particularly for densely built-up areas. This indicates that the present approach to estimating aerodynamic roughness parameters, taking account of both roughness density and building height variability, is more appropriate than conventional approaches when applied to actual urban areas. The roughness aerodynamic parameters as a function of λf and Vh obtained from the LES results will be useful in incorporating urban effects into weather forecasting models.
Artificial Cloud Seeding Using Liquid Carbon Dioxide: Comparisons of Experimental Data and Numerical Analyses
Authors: Seto Jinichiro , Tomine Kikuro , Wakimizu Kenji , Nishiyama Koji
Published: March 2011

An artificial seeding experiment was carried out over the Genkai Sea, Japan, using liquid carbon dioxide. The seeded cloud was followed by an aircraft and radar at Kyushu University. A radar-echo intensity of 19 dBZ was formed in the seeded cloud where no radar echo was observed previously. The results of the experiment are analyzed using a numerical model [Weather Research and Forecasting Model (WRF), version 3.1] to evaluate the effects of the artificial seeding. The numerically simulated radar echo has a slightly stronger intensity and wider area than that observed. The results of the experiments were similar to those produced by the numerical model, however. Evaporation of cloud liquid water; growth of snow particles that is due to deposition, autoconversion, aggregation, and collection; and convection caused by released latent heat are shown in the numerical results as effects of the seeding experiment. The falling snow particles cause downward flow, which is compensated for by upward flow that causes the formation of new cloud liquid water as a secondary effect of seeding, although this secondary effect is confirmed only in the numerical results.
Investigation of GOSAT TANSO-CAI Cloud Screening Ability through an Intersatellite Comparison
Authors: Ishida Haruma , Nakjima Takashi Y. , Yokota Tatsuya , Kikuchi Nobuyuki , Watanabe Hiroshi
Published: March 2011

In this work, the Greenhouse Gases Observing Satellite (GOSAT) Thermal and Near-infrared Sensor for Carbon Observation–Cloud and Aerosol Imager (TANSO-CAI) cloud screening results, which are necessary for the retrieval of carbon dioxide (CO2) and methane (CH4) gas amounts from GOSAT TANSO–Fourier Transform Spectrometer (FTS) observations, are compared with results from Aqua/Moderate Resolution Imaging Spectroradiometer (MODIS) in four seasons. A large number of pixels, acquired from both satellites with nearly coincident locations and times, are extracted for statistical comparisons. The same cloud screening algorithm was applied to both satellite datasets to focus on the performance of the individual satellite sensors, without concern for differences in algorithms. The comparisons suggest that CAI is capable of discriminating between clear and cloudy areas over water without sun glint and also may be capable of identifying thin cirrus clouds, which are generally difficult to detect without thermal infrared or near-infrared bands. On the other hand, cloud screening over land by CAI resulted in greater cloudy discrimination than that by MODIS, whereas detection of thin cirrus clouds tended to be more difficult over land than water, resulting in incorrect identification of thin cirrus as clear. The amount of missed thin cirrus had a seasonal variation, with the maximum occurring in summer. The cloudy tendency of CAI over half vegetation is caused by lack of an effective threshold test that can be applied to MODIS. The statistical results of the comparison clarified the important points to consider when using the results of CAI cloud screening.
Severe Ice Conditions in the Bohai Sea, China, and Mild Ice Conditions in the Great Lakes during the 2009/10 Winter: Links to El Niño and a Strong Negative Arctic Oscillation
Authors: Bai Xuezhi , Wang Jia , Liu Qinzheng , Wang Dongxiao , Liu Yu
Published: March 2011

This study investigates the causes of severe ice conditions over the Bohai Sea, China, and mild ice cover over the North American Great Lakes under the same hemispheric climate patterns during the 2009/10 winter with a strong negative Arctic Oscillation (AO) and an El Niño event. The main cause of severe ice cover over the Bohai Sea was the strong negative AO. Six of seven winters with severe ice were associated with a strong negative AO during the period 1954–2010. The Siberian high (SH) in the 2009/10 winter was close to normal. The influence of El Niño on the Bohai Sea was not significant. In contrast, the mild ice conditions in the Great Lakes were mainly caused by the strong El Niño event. Although the negative AO generally produces significant colder surface air temperature (SAT) and heavy ice cover over the Great Lakes, when it coincided with a strong El Niño event during the 2009/10 winter the El Niño–induced Pacific–North America (PNA)-like pattern dominated the midlatitudes and was responsible for the flattening of the ridge–trough system over North America, leading to warmer-than-normal temperatures and mild ice conditions over the Great Lakes. This comparative study revealed that interannual variability of SAT in North America, including the Great Lakes, is effectively influenced by El Niño events through a PNA or PNA-like pattern whereas the interannual variability of SAT in northeastern China, including the Bohai Sea area, was mainly controlled by AO and SH.
Maximizing the Statistical Diversity of an Ensemble of Bred Vectors by Using the Geometric Norm
Authors: Pazó Diego , Rodríguez Miguel A. , López Juan M.
Published: March 2011

It is shown that the choice of the norm has a great impact on the construction of ensembles of bred vectors. The geometric norm maximizes (in comparison with other norms such as the Euclidean one) the statistical diversity of the ensemble while at the same time it enhances the growth rate of the bred vector and its projection on the linearly most unstable direction (i.e., the Lyapunov vector). The geometric norm is also optimal in providing the least fluctuating ensemble dimension among all the spectrum of norms studied. The results are exemplified with numerical integrations of a toy model of the atmosphere (the Lorenz-96 model), but these findings are expected to be generic for spatially extended chaotic systems.
Climate Variability and Radiocarbon in the CM2Mc Earth System Model
Authors: Galbraith Eric D. , Kwon Eun Young , Gnanadesikan Anand , Rodgers Keith B. , Griffies Stephen M. , Bianchi Daniele , Sarmiento Jorge L. , Dunne John P. , Simeon Jennifer , Slater Richard D. , Wittenberg Andrew T. , Held Isaac M.
Published: March 2011

The distribution of radiocarbon (14C) in the ocean and atmosphere has fluctuated on time scales ranging from seasons to millennia. It is thought that these fluctuations partly reflect variability in the climate system, offering a rich potential source of information to help understand mechanisms of past climate change. Here, a long simulation with a new, coupled model is used to explore the mechanisms that redistribute 14C within the earth system on interannual to centennial time scales. The model, the Geophysical Fluid Dynamics Laboratory Climate Model version 2 (GFDL CM2) with Modular Ocean Model version 4p1(MOM4p1) at coarse-resolution (CM2Mc), is a lower-resolution version of the Geophysical Fluid Dynamics Laboratory’s CM2M model, uses no flux adjustments, and is run here with a simple prognostic ocean biogeochemistry model including 14C. The atmospheric 14C and radiative boundary conditions are held constant so that the oceanic distribution of 14C is only a function of internal climate variability. The simulation displays previously described relationships between tropical sea surface 14C and the model equivalents of the El Niño–Southern Oscillation and Indonesian Throughflow. Sea surface 14C variability also arises from fluctuations in the circulations of the subarctic Pacific and Southern Ocean, including North Pacific decadal variability and episodic ventilation events in the Weddell Sea that are reminiscent of the Weddell Polynya of 1974–76. Interannual variability in the air–sea balance of 14C is dominated by exchange within the belt of intense “Southern Westerly” winds, rather than at the convective locations where the surface 14C is most variable. Despite significant interannual variability, the simulated impact on air–sea exchange is an order of magnitude smaller than the recorded atmospheric 14C variability of the past millennium. This result partly reflects the importance of variability in the production rate of 14C in determining atmospheric 14C but may also reflect an underestimate of natural climate variability, particularly in the Southern Westerly winds.
First Observations of Microbaroms with Single Absolute Barometers
Authors: Subramanian Ganesh K. , Muschinski Andreas
Published: March 2011

The first observations of microbaroms with single absolute barometers are presented and discussed. Microbaroms are pulses of atmospheric infrasound emitted by ocean surface waves. They can propagate over thousands of kilometers through the atmosphere, and they can reach altitudes well into the upper atmosphere before they are refracted down to the earth’s surface. Typical microbarom periods are 5 s, typical wavelengths are 1.5 km, and typical surface amplitudes are 100 mPa (1 μbar). The data presented here were collected during the 2-week period from 26 February through 10 March 2008 in Amherst, Massachusetts, which is located about 150 km away from the Atlantic Ocean. The authors report for the first time, to the best of their knowledge, an f−5 microbarom frequency spectrum, which is consistent with Phillips’s f−5 ocean surface wave equilibrium spectrum.
On Domain Localization in Ensemble-Based Kalman Filter Algorithms
Authors: Janjić Tijana , Nerger Lars , Albertella Alberta , Schröter Jens , Skachko Sergey
Published: March 2011

Ensemble Kalman filter methods are typically used in combination with one of two localization techniques. One technique is covariance localization, or direct forecast error localization, in which the ensemble-derived forecast error covariance matrix is Schur multiplied with a chosen correlation matrix. The second way of localization is by domain decomposition. Here, the assimilation is split into local domains in which the assimilation update is performed independently. Domain localization is frequently used in combination with filter algorithms that use the analysis error covariance matrix for the calculation of the gain like the ensemble transform Kalman filter (ETKF) and the singular evolutive interpolated Kalman filter (SEIK). However, since the local assimilations are performed independently, smoothness of the analysis fields across the subdomain boundaries becomes an issue of concern.

To address the problem of smoothness, an algorithm is introduced that uses domain localization in combination with a Schur product localization of the forecast error covariance matrix for each local subdomain. On a simple example, using the Lorenz-40 system, it is demonstrated that this modification can produce results comparable to those obtained with direct forecast error localization. In addition, these results are compared to the method that uses domain localization in combination with weighting of observations. In the simple example, the method using weighting of observations is less accurate than the new method, particularly if the observation errors are small.

Domain localization with weighting of observations is further examined in the case of assimilation of satellite data into the global finite-element ocean circulation model (FEOM) using the local SEIK filter. In this example, the use of observational weighting improves the accuracy of the analysis. In addition, depending on the correlation function used for weighting, the spectral properties of the solution can be improved.
Accounting for Observational Uncertainty in Forecast Verification: An Information-Theoretical View on Forecasts, Observations, and Truth
Authors: Weijs Steven V. , van de Giesen Nick
Published: March 2011

Recently, an information-theoretical decomposition of Kullback–Leibler divergence into uncertainty, reliability, and resolution was introduced. In this article, this decomposition is generalized to the case where the observation is uncertain. Along with a modified decomposition of the divergence score, a second measure, the cross-entropy score, is presented, which measures the estimated information loss with respect to the truth instead of relative to the uncertain observations. The difference between the two scores is equal to the average observational uncertainty and vanishes when observations are assumed to be perfect. Not acknowledging for observation uncertainty can lead to both overestimation and underestimation of forecast skill, depending on the nature of the noise process.
The VDAC Technique: A Variational Method for Detecting and Characterizing Convective Vortices in Multiple-Doppler Radar Data
Authors: Potvin Corey K. , Shapiro Alan , Biggerstaff Michael I. , Wurman Joshua M.
Published: March 2011

The vortex detection and characterization (VDAC) technique is designed to identify tornadoes, mesocyclones, and other convective vortices in multiple-Doppler radar data and retrieve their size, strength, and translational velocity. The technique consists of fitting radial wind data from two or more radars to a simple analytical model of a vortex and its near environment. The model combines a uniform flow, linear shear flow, linear divergence flow (all of which comprise a broad-scale flow), and modified combined Rankine vortex. The vortex and its environmental flow are allowed to translate. A cost function accounting for the discrepancy between the model and observed radial winds is evaluated over space and time so that observations can be used at the actual times and locations they were acquired. The model parameters are determined by minimizing this cost function.

Tests of the technique using analytically generated, numerically simulated, and one observed tornadic wind field were presented by Potvin et al. in an earlier study. In the present study, an improved version of the technique is applied to additional real radar observations of tornadoes and other substorm-scale vortices. The technique exhibits skill in detecting such vortices and characterizing their size and strength. Single-Doppler experiments suggest that the technique may reliably detect and characterize larger (>1-km diameter) vortices even in the absence of overlapping radar coverage.
Digital Expression Among Urban, Low-Income African American Adolescents
Authors: Baker Christina M. , Staiano Amanda E. , Calvert Sandra L.
Published: March 2011

Digital production is a means through which African American adolescents communicate and express their experiences with peers. This study examined the content and the form of the digital productions of 24 urban, low-income African American adolescents who attended a summer academic program. The content of student digital productions focused on academic experiences and friendships. Their production styles revealed that youth used perceptually salient production features, such as rapid scene changes and loud rap music. The results suggest that when placed in a supportive, academic environment and provided with digital production resources, students who traditionally face barriers due to cultural and economic inequalities digitally express to their peers an interest in academics and positive peer relationships, and that these youth communicate their experiences through a shared production style that reflects their broader cultural experiences.
Chronic Restraint Stress in Oral Squamous Cell Carcinoma
Authors: Rivera C.A. , Droguett D.A. , Kemmerling U. , Venegas B.A.
Published: March 2011

Pathogenic processes have been identified that could associate chronic stress and cancer, but these findings have not been observed in oral cancer. This study examined the role of chronic restraint stress on the incidence and severity of OSCC induced with 4-nitroquinoline-1-oxide (4-NQO) in the tongues of CF-1 mice. One hundred twenty CF-1 male mice were divided into 4 groups: (A) received two treatments — restraint stress and induction of chemical carcinogenesis (n = 50); (B) induction of chemical carcinogenesis, without restraint stress (n = 50); (C) restraint stress (n = 10); and (D) control (n = 10). After 30 weeks, tongues were dissected and analyzed by conventional histopathology. The severity of OSSC was analyzed according to the International Histological Classification of Tumors and Bryne’s Multifactorial Grading System for the Invasive Tumor Front (ITF). Chronic stress induction was confirmed by plasma corticosterone levels. Results showed that chronic stress was induced with movement restriction (p ≤ 0.05, Mann-Whitney U-test). However, chronic stress did not increase the incidence (p > 0.05, Chi-square) or severity (p > 0.05, Mann-Whitney U-test) of the 4-NQO-induced OSSC in the tongues of CF-1 mice. These results suggest that there is no relationship between chronic stress (induced in mice by restraint) and the incidence and severity of OSSC.