bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum Antibodies in First-Degree Relatives of Patients with IBD: A Marker of Disease Susceptibility? A Follow-Up Pilot-Study after 7 Years
Authors: Török H.P. , Glas J. , Hollay H.C. , Gruber R. , Osthoff M. , Tonenchi L. , Brückl C. , Mussack T. , Folwaczny M. , Folwaczny C.
Published: September 2005

Introduction: Various disease-specific serum antibodies were described in patients with inflammatory bowel disease and their yet healthy first-degree relatives. In the latter, serum antibodies are commonly regarded as potential markers of disease susceptibility. The present long-term follow-up study evaluated the fate of antibody-positive first-degree relatives. Patients and Methods: 25 patients with Crohn’s disease, 19 patients with ulcerative colitis and 102 first-degree relatives in whom presence of ASCA, pANCA, pancreatic- and goblet-cell antibodies had been assessed were enrolled. The number of incident cases with inflammatory bowel disease was compared between antibody-positive and antibody-negative first-degree relatives 7 years after storage of serum samples. Results: 34 of 102 (33%) first-degree relatives were positive for at least one of the studied serum antibodies. In the group of first-degree relatives, one case of Crohn’s disease and one case of ulcerative colitis were diagnosed during the follow-up period. However, both relatives did not display any of the investigated serum antibodies (p = 1). Discussion: The findings of our pilot study argue against a role of serum antibodies as a marker of disease susceptibility in first-degree relatives of patients with inflammatory bowel disease. However, these data have to await confirmation in larger ideally prospective multicenter studies before definite conclusions can be drawn.
Increasing the Infliximab Dose Is Beneficial in Crohn’s Disease Patients Who Responded to a Lower Dose and Relapsed
Authors: Menachem Yoram , Avidan Benjamin , Lavy Alexandra , Lang Alon , Bardan Eytan , Fidder Herma , Bar-Meir Simon , Chowers Yehuda
Published: September 2005

Background: Relapse after an initial response to infliximab therapy poses a problem for maintenance treatment. Aim: To assess the effects of increasing the infliximab dosage in Crohn’s disease (CD) patients who initially responded but flared during maintenance therapy. Methods: This was an observational study. Twelve CD patients with both inflammatory and fistulizing manifestations were included. All patients initially responded to 5 mg/kg of infliximab, relapsed during maintenance therapy, and were treated with 10 mg/kg. The Harvey-Bradshaw index, the fistula activity, and steroid use were assessed before and after treatment with the increased dose of infliximab. Results: The mean Harvey-Bradshaw index score after flare-up during treatment with 5 mg/kg of infliximab was 13.5 ± 3.7. Treatment with 10 mg/kg, in a mean of 3.3 infusions, decreased the activity score to a mean of 8.8 ± 2.5. Two patients were weaned off prednisone, and a reduced dose was possible in the other steroid-treated patients. Conclusions: Increasing the infliximab dose may be beneficial in CD patients who initially responded to therapy, but relapsed during maintenance with the lower dosage.
Edkins and a Century of Acid Suppression
Authors: Modlin I.M. , Sachs G. , Wright N. , Kidd M.
Published: September 2005

In 1905, John Edkins (1863–1940) undertook the studies of gastrin that have subsequently formed the basis for a century of investigation into the physiological basis of acid secretion and led to the elucidation of a variety of acid-suppressive pharmacological agents that have revolutionized the management of acid peptic disease. Although his name is known to few, his contributions to the physiology of gastric secretion and his study of spiral organisms in the stomach were prescient and to this day remain models of insightful and rigorous research. As a mentor, his educational impact was exemplified by the fact that he was the first to teach physiology to women in the United Kingdom. Gastrin has evolved from an initially unaccepted phenomenon, to be recognized as an important hormone and a fundamental component of regulatory biology as well as a clinically relevant biomarker of disease. Its critical role in the modulation of acid secretion has become a sine qua non and has been extended to include a broad regulatory proliferative role in the mucosa of the gastrointestinal tract. The pivotal role of gastrin in gastric physiology, biology and clinical medicine is now well accepted and reflects the fundamental contributions that Edkins made to the identification of the agent and the elucidation of its function. As a result of the delineation of the neural and hormonal regulatory mechanisms of acid secretion, the scientific basis of acid peptic disease has become apparent. The identification of histamine receptors and proton pumps has led to the discovery of novel pharmacotherapeutic agents capable of producing acid suppression of such efficacy that surgery has become virtually obsolete in the treatment of the disease process. A century after the initial observations by Edkins of gastrin, the identification of Helicobacter pylori and the ability to eradicate it, as well as the use of the proton pump inhibitor class of drugs, have revolutionized the management of gastroduodenal ulceration and gastroesophageal reflux disease. Both patients and physicians owe a great debt to Edkins, whose seminal observations regarding gastrin initiated an era of gastrointestinal scientific, clinical and pharmacological advance that has culminated in the ability to treat and cure acid peptic disease.
Early Surgery for the Treatment of Toxic Megacolon
Authors: D’Amico Carmelo , Vitale Alessandro , Angriman Imerio , Ruffolo Cesare , D’Amico Francesco , Valente Domenico , Berto Maurizio , Vella Vincenzo , Scarpa Marco , D’Amico Davide Francesco
Published: September 2005

Background: Toxic megacolon (TM) is a potentially lethal complication of idiopathic inflammatory bowel disease or infectious colitis, characterized by total or segmental non-obstructive colonic dilatation of at least 6 cm associated with systemic toxicity. Methods: Overall, 15 patients had surgery for TM at our institutions over a 10-year period (1993–2003). In contrast to other studies that used medical therapy as the first-line treatment for TM, in our experience all patients underwent surgery as soon as possible after diagnosis of TM (early surgery). Results: 14 patients underwent subtotal colectomy with terminal ileostomy, while for 1 patient the surgical procedure consisted only in a decompressive cecostomy. Two major complications occurred consisting of 2 cases of multiple organ failure leading to death. No other major complications or deaths were reported. The overall mortality rate was therefore 13% (0% in patients <65 years). Conclusion: This study shows that early surgery has the potential to represent a valid therapeutic strategy for patients with TM resulting in a small number of TM-related complications and deaths. Elderly patients seem to have a high risk of multiple organ dysfunction syndrome and post-surgical death.
Increased Prevalence of Colorectal Adenomas in Women with Breast Cancer
Authors: Ochsenkühn Thomas , Bayerdörffer Ekkehard , Meining Alexander , Späth Lydia , Mannes Gerd Alexander , Wiebecke Baldur , Eiermann Wolfgang , Sackmann Michael , Göke Burkhard
Published: September 2005

Background: The frequency of colorectal adenomas and carcinomas was investigated in a large cohort of women with breast cancer in comparison with matched controls, since data on the occurrence of second tumors in women with breast cancer is controversial. Design: In a cohort study, 188 consecutive women (median age 57 years) with primary breast cancer and 376 age-matched women who served as controls were examined by total colonoscopy. Breast cancer patients and controls were compared for the frequency of colorectal adenomas and carcinomas. Results: Women with breast cancer showed a higher risk of colorectal adenomas than controls (14.9 vs. 9.3%, p = 0.047, OR 1.7, 95% CI 1.0–2.9). This increased prevalence resulted primarily from an increased prevalence in the age group 65–85 (31 vs. 10%, p = 0.004, OR 3.8, 95% CI 1.6–9.3). Colorectal carcinomas were found infrequently in both groups (2 in each group). Women with breast cancer receiving anti-estrogen therapy showed a trend towards a lower risk of adenomas compared to women without anti-estrogen therapy (3.7 vs. 17.2%, p = 0.053, OR 0.16, 95% CI 0.0–1.1). Conclusions: Women with breast cancer above the age of 65 years have an increased risk of colorectal adenomas compared to women without breast cancer. Women with a diagnosis of breast cancer should especially be encouraged to participate in colorectal cancer-screening programs which, in most countries, call for screening of all average-risk individuals over the age of 50 years.
IQGAP1 Regulates Reactive Oxygen Species–Dependent Endothelial Cell Migration Through Interacting With Nox2
Authors: Ikeda Satoshi , Yamaoka-Tojo Minako , Hilenski Lula , Patrushev Nikolay A. , Anwar Ghulam M. , Quinn Mark T. , Ushio-Fukai Masuko
Published: September 2005

Objective—

Endothelial cell (EC) migration is a key event for repair process after vascular injury and angiogenesis. EC migration is regulated by reorganization of the actin cytoskeleton at the leading edge and localized production of reactive oxygen species (ROS) at the site of injury. However, underlying mechanisms are unclear. We reported that IQGAP1, an actin binding scaffold protein, mediates VEGF-induced activation of gp91phox (Nox2)-dependent NAD(P)H oxidase and EC migration. We thus hypothesized that Nox2 and IQGAP1 may play important roles in ROS-dependent EC migration in response to injury.

Methods and Results—

Using a monolayer scratch assay with confluent ECs, we show that ROS production is increased at the margin of scratch area and Nox2 translocates to the leading edge, where it colocalizes and associates with both actin and IQGAP1 in migrating ECs. Knockdown of IQGAP1 using siRNA and inhibition of the actin cytoskeleton blocked scratch injury-induced H
2
O
2
production, Nox2 translocation and its interaction with actin, and EC migration toward the injured site.

Conclusions—

These suggest that IQGAP1 may function to link Nox2 to actin at the leading edge, thereby facilitating ROS production at the site of injury, which may contribute to EC migration.
Extending Reperfusion Therapy for Acute Ischemic Stroke
Authors: Molina Carlos A. , Saver Jeffrey L.
Published: September 2005

Background and Purpose—

Reperfusion is the most beneficial of all therapeutic strategies for acute ischemic stroke. However, the standard cerebral reperfusion treatment of the first decade of the reperfusion era, noncontrast computed tomography (CT)–guided, ≤3 hours, intravenous tissue plasminogen activator, has many limitations. This review surveys emerging strategies that have the potential to extend cerebral reperfusion therapy to larger numbers of patients.

Summary of Review—

Innovative intravenous pharmacological reperfusion strategies include novel fibrinolytic agents (tenecteplase, reteplase, desmetolplase, plasmin, and microplasmin), glycoprotein (GP) IIb/IIIa antagonists with platelet disaggregating effects (abciximab and tirofiban), combination therapies to improve efficacy of clot lysis (fibrinolytics and GP IIb/IIIa agents, and fibrinolytics and direct thrombin inhibitors), increase the time window for clot lysis (fibrinolytics and neuroprotectants), and reduce the frequency of hemorrhagic complications (fibrinolytics and vasoprotectants), and externally applied ultrasound to enhance enzymatic fibrinolysis. Promising intra-arterial pharmacological reperfusion approaches include novel fibrinolytic agents, combined intravenous and intra-arterial fibrinolysis, and combined fibrinolytics and GP IIb/IIIa agents. Emerging endovascular mechanical reperfusion strategies include intra-arterial thrombectomy (clot retrieval devices and suction thrombectomy devices), mechanical disruption (micro-guidewire passage, laser photoacoustic emulsification, and primary intracranial angioplasty), and augmented fibrinolysis by endovascular ultrasound. Multimodal imaging, with magnetic resonance (MR) or CT, can rapidly assess infarct core, penumbra, site of vessel occlusion, and tissue hemorrhagic propensity, enabling improved selection of patients for reperfusion therapy beyond any arbitrary fixed time window.

Conclusions—

Therapeutic reperfusion is emerging as a treatment strategy of remarkable power and scope for rescuing patients experiencing acute brain ischemia, applicable within and beyond the 3-hour time window.
Polymorphisms in Transforming Growth Factor-β-Related Genes
ALK1
and
ENG
Are Associated With Sporadic Brain Arteriovenous Malformations
Authors: Pawlikowska Ludmila , Tran Mary N. , Achrol Achal S. , Ha Connie , Burchard Esteban , Choudhry Shweta , Zaroff Jonathan , Lawton Michael T. , Castro Richard , McCulloch Charles E. , Marchuk Douglas , Kwok Pui-Yan , Young William L.
Published: September 2005

Background and Purpose—

Mutations in endoglin (
ENG
) and activin-like kinase (
ALK1
) cause hereditary hemorrhagic telangiectasias, disorders characterized by pulmonary and brain arteriovenous malformations (BAVMs). We investigated whether polymorphisms in these genes are also associated with sporadic BAVM.

Methods—

A total of 177 sporadic BAVM patients and 129 controls (all subjects white) were genotyped for 2 variants in
ALK1
and 7 variants in
ENG
.

Results—

The
ALK1
IVS3-35A>G polymorphism was associated with BAVM: (AnyA [AA+AG] genotype: odds ratio, 2.47; 95% CI, 1.38 to 4.44;
P
=0.002). Two
ENG
polymorphisms,
ENG
−1742A>G and
ENG
207G>A, showed a trend toward association with BAVM that did not reach statistical significance.

Conclusions—

A common polymorphism in
ALK1
is associated with sporadic BAVM, suggesting that genetic variation in genes mutated in familial BAVM syndromes may play a role in sporadic BAVMs.
Losartan Metabolite EXP3179 Activates Akt and Endothelial Nitric Oxide Synthase via Vascular Endothelial Growth Factor Receptor-2 in Endothelial Cells
Authors: Watanabe Tetsu , Suzuki Jun , Yamawaki Hideyuki , Sharma Virendra K. , Sheu Shey-Shing , Berk Bradford C.
Published: September 2005

Background—

Recent studies suggest that angiotensin type 1 receptor (AT1R) blockers have vascular protective effects beyond blood pressure lowering. Because of the importance of endothelial nitric oxide synthase (eNOS) in vascular and platelet function, we hypothesized that losartan and its metabolites would stimulate eNOS and its upstream activators Akt and phosphatidylinositol 3-kinase (PI3K).

Methods and Results—

Losartan is metabolized into EXP3174 (AT1R-blocking metabolite) and EXP3179 (no AT1R-blocking properties). Treatment of endothelial cells (ECs) with losartan and both metabolites stimulated phosphorylation of Akt and eNOS in the absence of angiotensin II. However, the magnitude for EXP3179 was much greater than EXP3174, and the EC
50
was significantly lower (−logEC
50
, 8.2±0.1 versus 5.4±0.2 mol/L), suggesting an AT1R-independent effect. Inhibiting PI3K or vascular endothelial growth factor receptor 2 (VEGFR2) tyrosine phosphorylation abrogated EXP3179-induced eNOS phosphorylation. In endothelium of intact rat aorta, EXP3179 also stimulated Akt and eNOS phosphorylation. VEGFR2 activation was shown to be calcium and Src family kinase dependent by use of specific drug inhibitors and dominant negative kinase transfection. EXP3179 significantly inhibited tumor necrosis factor α–induced apoptosis by ≈60% (from 30.1±5.8% to 12.2±2.0% TUNEL-positive cells), which was abolished by pretreatment with the PI3K inhibitor LY294002. Cleaved caspase-3 was suppressed by 48% with EXP3179.

Conclusions—

The losartan metabolite EXP3179 stimulates eNOS phosphorylation and suppresses tumor necrosis factor α–induced EC apoptosis by activating the VEGFR2/PI3K/Akt pathway.
Arterial Distensibility in Adolescents
Authors: Whincup P.H. , Gilg J.A. , Donald A.E. , Katterhorn M. , Oliver C. , Cook D.G. , Deanfield J.E.
Published: September 2005

Background—

Atherosclerosis develops from childhood, but the determinants of this preclinical stage remain uncertain. We examined the relations of classic coronary risk factors, adiposity and its associated metabolic disturbances, to arterial distensibility (a marker of early arterial disease) in 13- to 15-year-olds, some of whom had previously been studied at ages 9 to 11 years.

Methods and Results—

Brachial artery distensibility was measured by a noninvasive ultrasound technique in 471 British children in whom measures of adiposity, blood pressure, fasting blood lipids, and insulin had been made. All adiposity measures showed strong graded inverse relationships with distensibility. Inverse associations with distensibility were also observed for insulin resistance (homeostasis model assessment), diastolic pressure, C-reactive protein, and the number of metabolic syndrome components present, which had a graded relation to distensibility. Total and LDL cholesterol levels were also inversely related to distensibility, but less strongly than adiposity; homocysteine had no relation to distensibility. Although the relations of total and LDL cholesterol and diastolic pressure to distensibility had been present at 9 to 11 years of age, those of adiposity and insulin resistance were only apparent at 13 to 15 years.

Conclusions—

Adiposity and its metabolic consequences are associated with adverse changes in the arterial wall by the teenage years. The graded relation with increasing adiposity was stronger than that for cholesterol and was seen at body mass index levels well below those considered to represent “obesity.” This emphasizes the importance of population-based strategies to control adiposity and its metabolic consequences in the young.
Role of Angiogenesis in Cardiovascular Disease
Authors: Khurana Rohit , Simons Michael , Martin John F. , Zachary Ian C.
Published: September 2005

The role of angiogenesis in atherosclerosis and other cardiovascular diseases has emerged as a major unresolved issue. Angiogenesis has attracted interest from opposite perspectives. Angiogenic cytokine therapy has been widely regarded as an attractive approach both for treating ischemic heart disease and for enhancing arterioprotective functions of the endothelium; conversely, a variety of studies suggest that neovascularization contributes to the growth of atherosclerotic lesions and is a key factor in plaque destabilization leading to rupture. Here, we critically review the evidence supporting a role for angiogenesis and angiogenic factors in atherosclerosis and neointima formation, emphasizing the problems raised by some of the landmark studies and the suitability of animal models of atherosclerosis and neointimal thickening for investigating the role of angiogenesis. Because many of the relevant studies have focused on the role of vascular endothelial growth factor (VEGF), we consider this work in the wider context of VEGF biology and in light of recent experience from clinical trials of VEGF and other angiogenic cytokines for ischemic heart disease. Also discussed are recent findings suggesting that, although angiogenesis may contribute to neointimal growth, it is not required for the initiation of intimal thickening. Our assessment of the evidence leads us to conclude that, although microvessels are a feature of advanced human atherosclerotic plaques, it remains unclear whether angiogenesis either plays a central role in the development of atherosclerosis or is responsible for plaque instability. Furthermore, current evidence from clinical trials of both proangiogenic and antiangiogenic therapies does not suggest that inhibition of angiogenesis is likely to be a viable therapeutic strategy for cardiovascular disease.
Safety and Feasibility of Autologous Myoblast Transplantation in Patients With Ischemic Cardiomyopathy
Authors: Dib Nabil , Michler Robert E. , Pagani Francis D. , Wright Susan , Kereiakes Dean J. , Lengerich Rose , Binkley Philip , Buchele Diane , Anand Inder , Swingen Cory , Di Carli Marcelo F. , Thomas James D. , Jaber Wael A. , Opie Shaun R. , Campbell Ann , McCarthy Patrick , Yeager Michael , Dilsizian Vasken , Griffith Bartley P. , Korn Ronald , Kreuger Steven K. , Ghazoul Marwan , MacLellan W. Robb , Fonarow Gregg , Eisen Howard J. , Dinsmore Jonathan , Diethrich Edward
Published: September 2005

Background—

Successful autologous skeletal myoblast transplantation into infarcted myocardium in a variety of animal models has demonstrated improvement in cardiac function. We evaluated the safety and feasibility of transplanting autologous myoblasts into infarcted myocardium of patients undergoing concurrent coronary artery bypass grafting (CABG) or left ventricular assist device (LVAD) implantation. In addition, we sought to gain preliminary information on graft survival and any associated changes in cardiac function.

Methods and Results—

Thirty patients with a history of ischemic cardiomyopathy participated in a phase I, nonrandomized, multicenter pilot study of autologous skeletal myoblast transplantation concurrent with CABG or LVAD implantation. Twenty-four patients with a history of previous myocardial infarction and a left ventricular ejection fraction <40% were enrolled in the CABG arm. In a second arm, 6 patients underwent LVAD implantation as a bridge to heart transplantation, and patients donated their explanted native hearts for testing at the time of heart transplantation. Myoblasts were successfully transplanted in all patients without any acute injection-related complications or significant long-term, unexpected adverse events. Follow-up positron emission tomography scans showed new areas of glucose uptake within the infarct scar in CABG patients. Echocardiography measured an average change in left ventricular ejection fraction from 28% to 35% at 1 year and of 36% at 2 years. Histological evaluation in 4 of 6 patients who underwent heart transplantation documented survival and engraftment of the skeletal myoblasts within the infarcted myocardium.

Conclusions—

These results demonstrate the survival, feasibility, and safety of autologous myoblast transplantation and suggest that this modality offers a potential therapeutic treatment for end-stage heart disease.
Comprehensive Survey of Common Genetic Variation at the Plasminogen Activator Inhibitor-1 Locus and Relations to Circulating Plasminogen Activator Inhibitor-1 Levels
Authors: Kathiresan Sekar , Gabriel Stacey B. , Yang Qiong , Lochner Amy L. , Larson Martin G. , Levy Daniel , Tofler Geoffrey H. , Hirschhorn Joel N. , O’Donnell Christopher J.
Published: September 2005

Background—

Using a linkage disequilibrium (LD)–based approach, we sought to comprehensively define common genetic variation at the plasminogen activator inhibitor-1 (
PAI-1
) locus and relate common single nucleotide polymorphisms (SNPs) and haplotypes to plasma PAI-1 levels.

Methods and Results—

In reference pedigrees, we defined LD structure across a 50-kb genomic segment spanning the
PAI-1
locus via a dense SNP map (1 SNP every 2 kb). Eighteen sequence variants that capture underlying common genetic variation were genotyped in 1328 unrelated Framingham Heart Study participants who had plasma PAI-1 antigen levels measured. Regression analyses were used to examine associations of individual SNPs and of inferred haplotypes with multivariable-adjusted PAI-1 levels. Two genetic variants, SNP rs2227631 and the 4G/5G polymorphism, were strongly associated (
P
<0.0001) with PAI-1 levels. SNP rs2227631 is in tight LD (D′=0.97,
r
2
=0.78) with the 4G/5G polymorphism, which makes it difficult to distinguish which of these 2 polymorphisms is responsible for the association with PAI-1 levels. In stepwise analysis considering all polymorphisms tested, 3 SNPs, rs2227631 (or the correlated 4G/5G polymorphism), rs6465787, and rs2227674, each explained 2.5%, 1%, and 1%, respectively, of the residual variance in multivariable-adjusted PAI-1 levels (stepwise
P
<0.0001,
P
=0.04, and
P
=0.03, respectively). A single common haplotype, at 50% frequency among Framingham Heart Study participants, was strongly associated with higher PAI-1 levels (haplotype-specific
P
=0.00001). The susceptibility haplotype harbors the minor alleles of SNP rs2227631 and the 4G/5G polymorphism.

Conclusions—

Three sequence variants at the
PAI-1
locus, in sum, explain ≈5% of the residual variance in multivariable-adjusted PAI-1 levels. For quantitative cardiovascular traits such as circulating biomarkers, defining LD structure in a candidate gene followed by association analyses with both SNPs and haplotypes is an effective approach to localize common susceptibility alleles.
An Introduction to the Near–Real–Time QuikSCAT Data
Authors: Hoffman Ross N. , Leidner S. Mark
Published: September 2005

The NASA Quick Scatterometer (QuikSCAT) satellite carries the SeaWinds instrument, the first satellite-borne scanning radar scatterometer. QuikSCAT, which was launched on 19 June 1999, is designed to provide accurate ocean surface winds in all conditions except for moderate to heavy rain (i.e., except for vertically integrated rain rate >2.0 km mm h−1, the value used to tune the SeaWinds rain flag). QuikSCAT data are invaluable in providing high-quality, high-resolution winds to detect and locate precisely significant meteorological features and to produce accurate ocean surface wind analyses. QuikSCAT has an 1800-km-wide swath. A representative swath of data in the North Atlantic at 2200 UTC 28 September 2000, which contains several interesting features, reveals some of the capabilities of QuikSCAT. Careful quality control is vital for flagging data that are affected by rain and for flagging errors during ambiguity removal. In addition, an understanding of the instrument and algorithm characteristics provides insights into the factors controlling data quality for QuikSCAT. For example data quality is reduced for low wind speeds, and for locations either close to nadir or to the swath edges. The special data characteristics of the QuikSCAT scatterometer are revealed by examining the likelihood or objective function. The objective function is equal to the sum of squared scaled differences between observed and simulated normalized reflected radar power. The authors present typical examples and discuss the associated data quality concerns for different parts of the swath, for different wind speeds, and for rain versus no rain.
An Operational System for Predicting Hurricane-Generated Wind Waves in the North Atlantic Ocean*
Authors: Chao Yung Y. , Alves Jose-Henrique G. M. , Tolman Hendrik L.
Published: September 2005

A new wind–wave prediction model, referred to as the North Atlantic hurricane (NAH) wave model, has been developed at the National Centers for Environmental Prediction (NCEP) to produce forecasts of hurricane-generated waves during the Atlantic hurricane season. A detailed description of this model and a comparison of its performance against the operational western North Atlantic (WNA) wave model during Hurricanes Isidore and Lili, in 2002, are presented. The NAH and WNA models are identical in their physics and numerics. The NAH model uses a wind field obtained by blending data from NCEP’s operational Global Forecast System (GFS) with those from a higher-resolution hurricane prediction model, whereas the WNA wave model uses winds provided exclusively by the GFS. Relative biases of the order of 10% in the prediction of maximum wave heights up to 48 h in advance, indicate that the use of higher-resolution winds in the NAH model provides a successful framework for predicting extreme sea states generated by a hurricane. Consequently, the NAH model has been made operational at NCEP for use during the Atlantic hurricane season.
Operational Forecasting of Wind-Generated Waves by Hurricane Isabel at NCEP*
Authors: Tolman Hendrik L. , Alves Jose-Henrique G. M. , Chao Yung Y.
Published: September 2005

The accuracy of the operational wave models at the National Centers for Environmental Prediction (NCEP) for sea states generated by Hurricane Isabel is assessed. The western North Atlantic (WNA) and the North Atlantic hurricane (NAH) wave models are validated using analyzed wind fields, and wave observations from the Jason-1 altimeter and from 15 moored buoys. Both models provided excellent guidance for Isabel in the days preceding landfall of the hurricane along the east coast of the United States. However, the NAH model outperforms the WNA model in the initial stages of Isabel, when she was a category 5 hurricane. The NAH model was also more accurate in providing guidance for the swell systems arriving at the U.S. coast well before landfall of Isabel. Although major model deficiencies can be attributed to shortcomings in the driving wind fields, several areas of potential wave model improvement have been identified.
The Tropical Rainfall Potential (TRaP) Technique. Part I: Description and Examples
Authors: Kidder Stanley Q. , Knaff John A. , Kusselson Sheldon J. , Turk Michael , Ferraro Ralph R. , Kuligowski Robert J.
Published: September 2005

Inland flooding caused by heavy rainfall from landfalling tropical cyclones is a significant threat to life and property. The tropical rainfall potential (TRaP) technique, which couples satellite estimates of rain rate in tropical cyclones with track forecasts to produce a forecast of 24-h rainfall from a storm, was developed to better estimate the magnitude of this threat. This paper outlines the history of the TRaP technique, details its current algorithms, and offers examples of its use in forecasting. Part II of this paper covers verification of the technique.
The Tropical Rainfall Potential (TRaP) Technique. Part II: Validation
Authors: Ferraro Ralph , Pellegrino Paul , Turk Michael , Chen Wanchun , Qiu Shuang , Kuligowski Robert , Kusselson Sheldon , Irving Antonio , Kidder Stan , Knaff John
Published: September 2005

Satellite analysts at the Satellite Services Division (SSD) of the National Environmental, Satellite, Data, and Information Service (NESDIS) routinely generate 24-h rainfall potential for all tropical systems that are expected to make landfall within 24 to at most 36 h and are of tropical storm or greater strength (>65 km h−1). These estimates, known as the tropical rainfall potential (TRaP), are generated in an objective manner by taking instantaneous rainfall estimates from passive microwave sensors, advecting this rainfall pattern along the predicted storm track, and accumulating rainfall over the next 24 h.

In this study, the TRaPs generated by SSD during the 2002 Atlantic hurricane season have been validated using National Centers for Environmental Prediction (NCEP) stage IV hourly rainfall estimates. An objective validation package was used to generate common statistics such as correlation, bias, root-mean-square error, etc. It was found that by changing the minimum rain-rate threshold, the results could be drastically different. It was determined that a minimum threshold of 25.4 mm day−1 was appropriate for use with TRaP. By stratifying the data by different criteria, it was discovered that the TRaPs generated using Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI) rain rates, with its optimal set of measurement frequencies, improved spatial resolution, and advanced retrieval algorithm, produced the best results. In addition, the best results were found for TRaPs generated for storms that were between 12 and 18 h from landfall. Since the TRaP is highly dependent on the forecast track of the storm, selected TRaPs were rerun using the observed track contained in the NOAA/Tropical Prediction Center (TPC) “best track.” Although some TRaPs were not significantly improved by using this best track, significant improvements were realized in some instances. Finally, as a benchmark for the usefulness of TRaP, comparisons were made to Eta Model 24-h precipitation forecasts as well as three climatological maximum rainfall methods. It was apparent that the satellite-based TRaP outperforms the Eta Model in virtually every statistical category, while the climatological methods produced maximum rainfall totals closer to the stage IV maximum amounts when compared with TRaP, although these methods are for storm totals while TRaP is for a 24-h period.
Further Improvements to the Statistical Hurricane Intensity Prediction Scheme (SHIPS)
Authors: DeMaria Mark , Mainelli Michelle , Shay Lynn K. , Knaff John A. , Kaplan John
Published: September 2005

Modifications to the Atlantic and east Pacific versions of the operational Statistical Hurricane Intensity Prediction Scheme (SHIPS) for each year from 1997 to 2003 are described. Major changes include the addition of a method to account for the storm decay over land in 2000, the extension of the forecasts from 3 to 5 days in 2001, and the use of an operational global model for the evaluation of the atmospheric predictors instead of a simple dry-adiabatic model beginning in 2001.

A verification of the SHIPS operational intensity forecasts is presented. Results show that the 1997–2003 SHIPS forecasts had statistically significant skill (relative to climatology and persistence) out to 72 h in the Atlantic, and at 48 and 72 h in the east Pacific. The inclusion of the land effects reduced the intensity errors by up to 15% in the Atlantic, and up to 3% in the east Pacific, primarily for the shorter-range forecasts. The inclusion of land effects did not significantly degrade the forecasts at any time period. Results also showed that the 4–5-day forecasts that began in 2001 did not have skill in the Atlantic, but had some skill in the east Pacific.

An experimental version of SHIPS that included satellite observations was tested during the 2002 and 2003 seasons. New predictors included brightness temperature information from Geostationary Operational Environmental Satellite (GOES) channel 4 (10.7 μm) imagery, and oceanic heat content (OHC) estimates inferred from satellite altimetry observations. The OHC estimates were only available for the Atlantic basin. The GOES data significantly improved the east Pacific forecasts by up to 7% at 12–72 h. The combination of GOES and satellite altimetry improved the Atlantic forecasts by up to 3.5% through 72 h for those storms west of 50°W.
A Reassessment of the Percentage of Tornadic Mesocyclones
Authors: Trapp Robert J. , Stumpf Gregory J. , Manross Kevin L.
Published: September 2005

A large set of data collected by numerous Weather Surveillance Radar-1988 Doppler (WSR-88D) units around the United States was analyzed to reassess the percentage of tornadic mesocyclones. Out of the 5322 individual mesocyclone detections that satisfied the relatively stringent WSR-88D Mesocyclone Detection Algorithm objective criteria, only 26% were associated with tornadoes. In terms of height or altitude of mesocyclone base, 15% of midaltitude mesocyclone detections were tornadic, and more than 40% of low-altitude mesocyclone detections (e.g., those with bases ≤ 1000 m above radar level) were tornadic. These results confirm that a low-altitude mesocyclone is much more likely to be associated with a tornado than is a midaltitude mesocyclone, and more generally, that the percentage of tornadic mesocyclones is indeed lower than previously thought.
Model Forecast Improvements with Decreased Horizontal Grid Spacing over Finescale Intermountain Orography during the 2002 Olympic Winter Games
Authors: Hart Kenneth A. , Steenburgh W. James , Onton Daryl J.
Published: September 2005

Forecasts produced for the 2002 Olympic and Paralympic Winter Games (23 January–25 March 2002) by a multiply nested version of the fifth-generation Pennsylvania State University–National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5) are examined to determine if decreasing horizontal grid spacing to 4 km improves forecast accuracy over the finescale topography of the Intermountain West. The verification is based on high-density observations collected by the MesoWest cooperative networks, including approximately 200 wind and temperature sites and 100 precipitation sites across northern Utah.

Wind and precipitation forecasts produced by the 4-km MM5 domain were more accurate (based on traditional measures) than those of its parent 12-km domain. The most significant improvements in wind speed forecasts occurred at night in valleys and lowland locations where the topography of the 4-km domain produced more accurate nocturnal flows. Wind direction forecast improvements were most substantial at mountain sites where the better topographic resolution of the 4-km domain more accurately reflected the exposure of these locations to the free atmosphere. The 4-km domain also produced quantitative precipitation forecasts that were either equally (small events) or more (large events) accurate than the 12-km domain. Precipitation bias errors varied substantially between the two domains since the representation of the region’s narrow, steeply sloped, basin-and-range topography improved dramatically at 4-km grid spacing.

Curiously, the overall accuracy of temperature forecasts by the 4-km domain was not significantly better than that of the 12-km domain. This was due to an inability of the MM5 to properly simulate nocturnal and persistent cold pools within mountain valleys and the lowlands upstream of the Wasatch Mountains. Paradoxically, the added resolution of the 4-km domain, coupled with the failure of this version of the MM5 to fully capture the nocturnal and persistent cold pools, resulted in poorer skill scores. At upper elevations, which are typically above the cold pools, the 4-km domain was substantially more accurate.

These results illustrate that decreasing horizontal grid spacing to less than 10 km does improve wind and precipitation forecasts over finescale Intermountain West topography. It is hypothesized that model improvements will ultimately enable the advantages of added model resolution to be fully realized for temperature forecasts over the Intermountain West.
Climatological Estimates of Daily Local Nontornadic Severe Thunderstorm Probability for the United States
Authors: Doswell Charles A. , Brooks Harold E. , Kay Michael P.
Published: September 2005

The probability of nontornadic severe weather event reports near any location in the United States for any day of the year has been estimated. Gaussian smoothers in space and time have been applied to the observed record of severe thunderstorm occurrence from 1980 to 1994 to produce daily maps and annual cycles at any point. Many aspects of this climatology have been identified in previous work, but the method allows for the consideration of the record in several new ways. A review of the raw data, broken down in various ways, reveals that numerous nonmeteorological artifacts are present in the raw data. These are predominantly associated with the marginal nontornadic severe thunderstorm events, including an enormous growth in the number of severe weather reports since the mid-1950s. Much of this growth may be associated with a drive to improve warning verification scores. The smoothed spatial and temporal distributions of the probability of nontornadic severe thunderstorm events are presented in several ways. The distribution of significant nontornadic severe thunderstorm reports (wind speeds ≥ 65 kt and/or hailstone diameters ≥ 2 in.) is consistent with the hypothesis that supercells are responsible for the majority of such reports.
The Heavy Rain Event of 29 October 2000 in Hana, Maui*
Authors: Lyman Ryan E. , Schroeder Thomas A. , Barnes Gary M.
Published: September 2005

On 29 October 2000, the Hana region of Maui received 700 mm of rain in 7 h. Radar analyses revealed that the storm consisted of seven cells that were initiated along the southeast slope of Haleakala volcano. One of these cells survived for nearly 4 h and was responsible for 80% of the volumetric rainout from the storm. The interaction of low-level flow distorted by the island of Hawaii located farther east, the passage of a trough, and the topographic forcing caused by Haleakala volcano were major factors responsible for the evolution of the storm.
An Objective Climatology of Carolina Coastal Fronts
Authors: Appel K. Wyat , Riordan Allen J. , Holley Timothy A.
Published: September 2005

This study describes a simple objective method to identify cases of coastal frontogenesis offshore of the Carolinas and to characterize the sensible weather associated with frontal passage at measurement sites near the coast. The identification method, based on surface hourly data from offshore and adjacent land stations, was applied to an 11-yr dataset (1984–94). A total of 379 coastal fronts was found, 70 of which eventually made landfall along the North Carolina coast; 112 that remained offshore, and 197 were termed diurnal since they remained offshore but disappeared during daylight hours.

Results show that most coastal and offshore sites experience a wind shift of about 40°–70° and a warming of about 2°–3°C during the hour of frontal passage. Exceptions include sites near colder waters where the rates are markedly reduced and frontal passage is often less discernible. Excluding diurnal fronts, just over half the cases were associated with cold-air damming (CAD) during the cold season of 16 October–15 April. Most of these winter cases linked with CAD were onshore fronts. During the warm season, most fronts were diurnal, but the association with CAD was still significant.

To explore the synoptic-scale environment, composite maps for the cold season were generated for all three frontal subtypes from NCEP–NCAR reanalysis data. Results show a strong surface anticyclone centered north of the region of frontogenesis for all three composites. However, several features in the synoptic-scale regimes appear to differentiate the three frontal types. For example, cyclogenesis in the Gulf of Mexico and onshore southeasterly low-level flow along the southeast Atlantic coast accompanied by warm advection distinguish onshore fronts from the other two types. The offshore fronts are accompanied by more nearly zonal flow aloft and a surface anticyclone that stalls near the New England coastline. Finally, the diurnal type is associated with much weaker pressure and height fields and an east–west elongated surface anticyclone centered much farther south than in the other cases.
Warm Season Lightning Distributions over the Northern Gulf of Mexico Coast and Their Relation to Synoptic-Scale and Mesoscale Environments
Authors: Smith Jessica R. , Fuelberg Henry E. , Watson Andrew I.
Published: September 2005

Cloud-to-ground lightning data from the National Lightning Detection Network are used to create a warm season (May–September) lightning climatology for the northern Gulf of Mexico coast for the 14-yr period 1989–2002. Each day is placed into one of five flow regimes based on the orientation of the low-level flow with respect to the coastline. This determination is made using the vector mean 1000–700-hPa wind data at Lake Charles and Slidell, Louisiana. Flash densities are calculated for daily, hourly, and nocturnal periods.

Spatial patterns of composite 24-h and nocturnal flash density indicate that lightning decreases in an east-to-west direction over the region. Flash densities for the 24-h period are greatest over land near the coast, with relative maxima located near Houston, Texas; Lake Charles, Baton Rouge, and New Orleans, Louisiana; Biloxi, Mississippi; and Mobile, Alabama. Flash densities during the nocturnal period are greatest over the coastal waters.

Lightning across the northern Gulf coast is closely related to the prevailing low-level synoptic flow, which controls the sea breeze, the dominant forcing mechanism during the warm season. Southwest flow, the most unstable and humid of the five regimes, exhibits the most flashes. In this case, sea-breeze-induced convection is located slightly inland from the coast. Northeast flow, the driest and most stable of the regimes, exhibits the least amount of lightning. The large-scale flow restricts the sea breeze to near the coastline.

Geographic features and local mesoscale circulations are found to affect lightning across the region. Geographic features include lakes, bays, marshes, swamps, and coastline orientations. Thermal circulations associated with these features interact with the main sea breeze to produce complex lightning patterns over the area.
A Multiscale Examination of the 31 May 1998 Mechanicville, New York, Tornado
Authors: LaPenta Kenneth D. , Bosart Lance F. , Galarneau Thomas J. , Dickinson Michael J.
Published: September 2005

On 31 May 1998, an F3 tornado struck Mechanicville, New York, injuring 68 people and causing $71 million in damage. The tornado was part of a widespread, severe weather outbreak across the northeast United States. The synoptic conditions that caused the outbreak and the mesoscale and storm-scale environments that produced the tornado are discussed.

The coupling of two strong upper-level jets and a very strong low-level jet, in association with an unseasonably strong surface cyclone, created a synoptic-scale environment favorable for severe weather. As the result of these jet interactions, a very warm, moist air mass was transported into the Northeast with an associated increase in the wind shear in the lower troposphere. A terrain-channeled low-level southerly flow up the Hudson Valley may have created a mesoscale environment that was especially favorable for tornadic supercell development by increasing storm-relative helicity in the low levels of the atmosphere and by transporting warm, moist air northward up the valley, leading to increased instability.

A broken line of locally severe thunderstorms moved eastward across New York several hours prior to the tornado. The storm that produced the Mechanicville tornado developed over central New York ahead of this line of storms. As the line of storms moved east, it intensified into a solid line and bowed forward down the Mohawk Valley of New York. These storms were moving faster than the isolated supercell to the east and overtook the supercell where the eastern end of the Mohawk Valley opens into the Hudson Valley. Based on limited observational evidence and the results of simulations of idealized quasi-linear convective systems reported elsewhere in the literature, it is hypothesized that backed low-level flow ahead of a bookend vortex at the northern end of the bowing line of storms over the Mohawk Valley may have contributed to the tornadogenesis process as the squall line overtook and interacted with the intensifying supercell.
Cloud-to-Ground Lightning Production in Strongly Forced, Low-Instability Convective Lines Associated with Damaging Wind
Authors: van den Broeke Matthew S. , Schultz David M. , Johns Robert H. , Evans Jeffry S. , Hales John E.
Published: September 2005

During 9–11 November 1998 and 9–10 March 2002, two similar convective lines moved across the central and eastern United States. Both convective lines initiated over the southern plains along strong surface-based cold fronts in moderately unstable environments. Both lines were initially associated with cloud-to-ground (CG) lightning, as detected by the National Lightning Detection Network, and both events met the criteria to be classified as derechos, producing swaths of widespread damaging wind. After moving into areas of marginal, if any, instability over the upper Midwest, CG lightning production ceased or nearly ceased, although the damaging winds continued. The 9 March 2002 line experienced a second phase of frequent CG lightning farther east over the mid-Atlantic states. Analysis of these two events shows that the production of CG lightning was sensitive to the occurrence and vertical distribution of instability. Periods with frequent CG lightning were associated with sufficient instability within the lower mixed-phase region of the cloud (i.e., the temperature range approximately between −10° and −20°C), a lifting condensation level warmer than −10°C, and an equilibrium level colder than −20°C. Periods with little or no CG lightning possessed limited, if any, instability in the lower mixed-phase region. The current Storm Prediction Center guidelines for forecasting these convective lines are presented.