bluuebunny/crossref_metadata_2025 huggingface dataset:
FINDING VALUE WHERE NONE EXISTS: PITFALLS IN USING ADJUSTED PRESENT VALUE
Authors: Booth Laurence
Published: April 2005

There are several conceptually “correct” methods for valuing firms and projects, including the weighted average cost of capital (WACC) approach, the flows to equity (FTE) method, and the adjusted present value (APV) or valuation‐by‐components method. The author examines the relative advantages of these frameworks and offers guidance as to when they are likely to be most useful. The key message is a caution to would‐be users of APV: it is frequently unreliable and should be used only in conjunction with more conventional valuation frameworks. It works best in transactions that involve structured financings, such as leveraged buyouts and project and real estate financings. Even in these cases, however, its usefulness depends on theoretical concepts that in practical applications have a wide margin of error.

In general, WACC is a robust and appropriate valuation framework as long as the firm has a target debt ratio. The FTE method is most relevant for acquisitions and very large projects. The author shows how APV and FTE can be formulated to be consistent with the WACC valuation. The issue, however, is not whether the techniques can be made consistent through relatively complex adjustments by sophisticated users, but rather what happens when they are used in everyday applications by practitioners unfamiliar with the somewhat arcane valuation issues involved.
Non-steroidal anti-inflammatory drugs and colorectal cancer prevention
Authors: Sangha S , Yao M , Wolfe M M
Published: April 2005

Colorectal cancer is the second leading cause of cancer deaths in the United States. Currently, the most effective strategy available for colon cancer prevention is endoscopic screening, with polypectomy or surgical resection for advanced lesions. This intervention carries with it many concerns regarding cost, patient acceptance, and the growing burden of surveillance colonoscopies for patients with polyps. Further improvements in the understanding of the multistep model of colorectal carcinogenesis will probably lead to the development of other primary and secondary prevention strategies. Data obtained from animal and epidemiological studies and most recently from randomised, placebo controlled trials, suggest that non-steroidal anti-inflammatory drugs may prove effective chemopreventive agents in different groups of people, from patients with familial adenomatous polyposis to those with sporadic adenomas.
Correlations of work, leisure, and sports physical activities and health status with socioeconomic factors: a national study in Israel
Authors: Kahan E , Fogelman Y , Bloch B
Published: April 2005

Objective

To evaluate levels of physical activities at work, leisure, and sports and to correlate them with socioeconomic and health factors.

Methods

Validated questionnaire administered to a random sample of 406 adults. Items covered demographic data, health status, smoking, and duration, frequency, intensity of physical activities. Indices of physical activity at work, leisure, and sports were analysed.

Results

Adults (both sexes) with poor self perceived health status and less than 13 years of education, regardless of their body mass index, perform no or few physical activities during their leisure time.

Conclusions

The correlations of physical activity with socioeconomic and health factors differ significantly for work, leisure, and sports. Physicians should differentiate physical activities by type and intensity during anamneses.
Angiogenesis: a curse or cure?
Authors: Gupta K , Zhang J
Published: April 2005

Angiogenesis, the growth of new blood vessels is essential during fetal development, female reproductive cycle, and tissue repair. In contrast, uncontrolled angiogenesis promotes the neoplastic disease and retinopathies, while inadequate angiogenesis can lead to coronary artery disease. A balance between pro-angiogenic and antiangiogenic growth factors and cytokines tightly controls angiogenesis. Considerable progress has been made in identifying these molecular components to develop angiogenesis based treatments. One of the most specific and critical regulators of angiogenesis is vascular endothelial growth factor (VEGF), which regulates endothelial proliferation, permeability, and survival. Several VEGF based treatments including anti-VEGF and anti-VEGF receptor antibodies/agents are in clinical trials along with several other antiangiogenic treatments. While bevacizumab (anti-VEGF antibody) has been approved for clinical use in colorectal cancer, the side effects of antiangiogenic treatment still remain a challenge. The pros and cons of angiogenesis based treatment are discussed.
Peritoneovenous shunting is an effective treatment for intractable ascites
Authors: Sooriakumaran P , McAndrew H F , Kiely E M , Spitz L , Pierro A
Published: April 2005

Aim and methods

A retrospective review was carried out of children undergoing peritoneovenous shunting for intractable ascites.

Results

11 children, aged 3 months to 12 years (median 31 months) underwent peritoneovenous shunting over the past 17 years. The duration of ascites ranged from one month to 2.5 years (median two months). The primary pathology consisted of previous surgery in eight (three neuroblastoma, one renal carcinoma, one hepatoblastoma, one adrenal teratoma, one renal artery stenosis, and one diaphragmatic hernia), and cytomegalovirus hepatitis, lymphatic hypoplasia, and lymphohistiocytosis in one patient each. All patients had failed to respond to previous treatment including peritoneal drainage in six patients, diuretics in five, and parenteral nutrition in five. There were no intraoperative problems. Postoperative complications included pulmonary oedema in three patients, shunt occlusion in three, infection in two, and wound leakage in one. Ascites resolved after shunting in 10 patients. Five shunts were removed one to three years after insertion without recurrence of ascites. Three others are free of ascites with shunts in place for less than one year postoperatively. Three children died from their underlying disease: two after resolution of ascites (neuroblastoma) and one in whom the ascites failed to resolve (lymphohisticytosis).

Conclusions

Peritoneovenous shunting is an effective treatment for symptomatic intractable ascites in children (10 of 11 successful cases in this series). Elective removal of the shunt after one year is recommended.
Autonomic dysreflexia: a medical emergency
Authors: Bycroft J , Shergill I S , Choong E A L , Arya N , Shah P J R
Published: April 2005

Autonomic dysreflexia is an important clinical diagnosis that requires prompt treatment to avoid devastating complications. The condition may present itself to all members of medical and surgical specialties, who may not be accustomed to treating it. It is the clinician’s responsibility to have a basic understanding of the pathophysiology of the condition and the simple steps required to treat it.
Role of surgery in the management of the adult patient with coarctation of the aorta
Authors: Ramnarine I
Published: April 2005

Adult patients with coarctation of the aorta have a range of clinical presentations. These include the presence of additional cardiovascular anomalies (predominantly aortic valve abnormality) and presentation with complications after coarctation repair in childhood (such as recurrent coarctation or aneurysm formation). Developments in endovascular technology over the past decade may potentially reduce the morbidity from open surgical repair. However, some cases are unsuitable for endovascular repair and open surgical techniques continue to play a part in the management of these patients. The number of adult patients with coarctation is very small and a trial comparing surgical and endovascular repair techniques would be difficult to arrange. A multidisciplinary team (consisting of cardiothoracic surgeon, interventional radiologist, cardiologist, and anaesthetist) is best equipped to manage the unique and complex problems that affect these patients. The current surgical options and factors governing the choice of approach are reviewed.
Darwin’s illness revealed
Authors: Campbell Anthony K , Matthews Stephanie B
Published: April 2005

After returning from the Beagle in 1836, Charles Darwin suffered for over 40 years from long bouts of vomiting, gut pain, headaches, severe tiredness, skin problems, and depression. Twenty doctors failed to treat him. Many books and papers have explained Darwin’s mystery illness as organic or psychosomatic, including arsenic poisoning, Chagas’ disease, multiple allergy, hypochondria, or bereavement syndrome. None stand up to full scrutiny. His medical history shows he had an organic problem, exacerbated by depression. Here we show that all Darwin’s symptoms match systemic lactose intolerance. Vomiting and gut problems showed up two to three hours after a meal, the time it takes for lactose to reach the large intestine. His family history shows a major inherited component, as with genetically predisposed hypolactasia. Darwin only got better when, by chance, he stopped taking milk and cream. Darwin’s illness highlights something else he missed—the importance of lactose in mammalian and human evolution.
Four gland parathyroidectomy without reimplantation in patients with chronic renal failure
Authors: Saunders R N , Karoo R , Metcalfe M S , Nicholson M L
Published: April 2005

Background

The optimal surgical management of patients in end stage chronic renal failure with secondary hyperparathyroidism is controversial. One approach advocated is four gland parathyroidectomy without reimplantation. The aim of this study was to review the medium term results of this procedure.

Methods

Fifty four consecutive patients with end stage chronic renal failure and secondary hyperparathyroidism who had a four gland parathyroidectomy without reimplantation were studied. The procedure was performed by a single surgeon with a median (range) follow up of 29 (0–70) months.

Results

Most patients (76%) developed postoperative hypocalcaemia but this was easily treated and doses of long term drugs necessary to prevent this were low. Pre-operative bone symptoms, hypercalcaemia, hyperphosphataemia, and an increased alkaline phosphatase were improved or resolved in most patients. Thirteen (24%) patients had an undetectable postoperative parathyroid hormone (PTH), (6 of 12 (50%) with a functioning renal transplant and 7 of 42 (17%) who required dialysis, p = 0.02). Median (range) postoperative PTH values in these groups were 0.1 (0.1–31) compared with 1.0 (0.1–24) pmol/l (p = 0.085) respectively. The remaining 41 of 54 (76%) patients had residual PTH secretion and postoperative hyperparathyroidism was identified in eight (15%) patients with only two requiring neck re-exploration.

Conclusion

Four gland parathyroidectomy without reimplantation produced good medium term biochemical and clinical results. Most patients had minor residual PTH secretion that may contribute to this and mitigate concerns regarding adynamic bone disease. Endogenous PTH secretion is only completely lost in a few patients but occurs more often in those with a functioning renal transplant. Bone densitometry is required to investigate the long term impact of this procedure.
Contaminants in common eiders (Somateria mollissima) of the Canadian Arctic
Authors: Mallory Mark L , Braune Birgit M , Wayland Mark , Gilchrist H Grant , Dickson D Lynne
Published: April 2005

Contamination of the Arctic environment by persistent organic pollutants (POPs) and trace elements remains a key concern for local residents as well as wildlife and resource management organizations. The common eider (Somateria mollissima) is a large marine duck that forms an important component of the diet of many Arctic predators, including humans. Although various studies have been carried out to evaluate the role of a few contaminants thought to be of local concern, efforts to assess contaminant residues in eider tissues have not been comprehensive. In this review, we summarize the available information on POPs and trace elements in common eiders across the Canadian Arctic. With the exception of one adult bird collected near Qikiqtarjuaq, Nunavut, eiders had detectable but low concentrations of most POPs, in some cases markedly lower than European eiders, and in all cases far lower than POP levels found in sympatric marine birds. However, common eiders did have elevated concentrations of many trace elements, noticeably cadmium, selenium, and copper, but these were below levels associated with toxicological risk to marine birds. Although the collective evidence suggests that common eiders of the Canadian Arctic may carry elevated levels of some contaminants, there was no evidence that these levels posed a threat to wildlife health. Key words: common Eider, persistent organic pollutants, trace elements, Arctic Canada.
COMPOSITE MATERIALS FOR WIND POWER TURBINE BLADES
Authors: Brøndsted Povl , Lilholt Hans , Lystrup Aage
Published: April 2005

▪ Abstract  Renewable energy resources, of which wind energy is prominent, are part of the solution to the global energy problem. Wind turbine and the rotorblade concepts are reviewed, and loadings by wind and gravity as important factors for the fatigue performance of the materials are considered. Wood and composites are discussed as candidates for rotorblades. The fibers and matrices for composites are described, and their high stiffness, low density, and good fatigue performance are emphasized. Manufacturing technologies for composites are presented and evaluated with respect to advantages, problems, and industrial potential. The important technologies of today are prepreg (pre-impregnated) technology and resin infusion technology. The mechanical properties of fiber composite materials are discussed, with a focus on fatigue performance. Damage and materials degradation during fatigue are described. Testing procedures for documentation of properties are reviewed, and fatigue loading histories are discussed, together with methods for data handling and statistical analysis of (large) amounts of test data. Future challenges for materials in the field of wind turbines are presented, with a focus on thermoplastic composites, new structural materials concepts, new structural design aspects, structural health monitoring, and the coming trends and markets for wind energy.
Phosphodiesterase-5 Inhibition With Sildenafil Attenuates Cardiomyocyte Apoptosis and Left Ventricular Dysfunction in a Chronic Model of Doxorubicin Cardiotoxicity
Authors: Fisher Patrick W. , Salloum Fadi , Das Anindita , Hyder Haroon , Kukreja Rakesh C.
Published: April 2005

Background—

Sildenafil, a phosphodiesterase-5 inhibitor, induces cardioprotection against ischemia/reperfusion injury via opening of mitochondrial K
ATP
channels. It is unclear whether sildenafil would provide similar protection from doxorubicin-induced cardiotoxicity.

Methods and Results—

Male ICR mice were randomized to 1 of 4 treatments: saline, sildenafil, doxorubicin (5 mg/kg IP), and sildenafil (0.7 mg/kg IP) plus doxorubicin (n=6 per group). Apoptosis was assessed with the use of terminal deoxynucleotidyl transferase–mediated dUTP nick-end labeling and in situ oligo ligation methods. Desmin distribution was determined via immunofluorescence. Bcl-2 expression was analyzed by Western blot. Left ventricular function was assessed by measuring developed pressure and rate pressure product in Langendorff mode. ECG changes indicative of doxorubicin cardiotoxicity were also measured. For in vitro studies, adult ventricular cardiomyocytes were exposed to doxorubicin (1 μmol/L), sildenafil (1 μmol/L) with or without
N
G
-nitro-
l
-arginine methyl ester (L-NAME) (100 μmol/L), or 5-hydroxydecanoate (100 μmol/L) 1 hour before doxorubicin and incubated for 18 hours. Doxorubicin-treated mice demonstrated increased apoptosis and desmin disruption, which was attenuated in the sildenafil+doxorubicin group. Bcl-2 was decreased in the doxorubicin group but was maintained at basal levels in the sildenafil+doxorubicin group. Left ventricular developed pressure and rate pressure product were significantly depressed in the doxorubicin group but were attenuated in the sildenafil+doxorubicin group. ST interval was significantly increased in the doxorubicin group over 8 weeks. In the sildenafil+doxorubicin group, ST interval remained unchanged from baseline. Doxorubicin caused a significant increase in apoptosis, caspase-3 activation, and disruption of mitochondrial membrane potential in vitro. In contrast, sildenafil significantly protected against doxorubicin cardiotoxicity; however, this protection was abolished by both L-NAME and 5-hydroxydecanoate.

Conclusions—

Prophylactic treatment with sildenafil prevented apoptosis and left ventricular dysfunction in a chronic model of doxorubicin-induced cardiomyopathy.
Novel Cardioprotective Role of a Small Heat-Shock Protein, Hsp20, Against Ischemia/Reperfusion Injury
Authors: Fan Guo-Chang , Ren Xiaoping , Qian Jiang , Yuan Qunying , Nicolaou Persoulla , Wang Yang , Jones W. Keith , Chu Guoxiang , Kranias Evangelia G.
Published: April 2005

Background—

Heat-shock proteins (Hsps) have been shown to render cardioprotection from stress-induced injury; however, little is known about the role of another small heat-shock protein, Hsp20, which regulates activities of vasodilation and platelet aggregation, in cardioprotection against ischemia injury. We recently reported that increased expression of Hsp20 in cardiomyocytes was associated with improved contraction and protection against β-agonist–induced apoptosis.

Methods and Results—

To investigate whether overexpression of Hsp20 exerts protective effects in both ex vivo and in vivo ischemia/reperfusion (I/R) injury, we generated a transgenic (TG) mouse model with cardiac-specific overexpression of Hsp20 (10-fold). TG and wild-type (WT) hearts were then subjected to global no-flow I/R (45 minutes/120 minutes) using the Langendorff preparation. TG hearts exhibited improved recovery of contractile performance over the whole reperfusion period. This improvement was accompanied by a 2-fold decrease in lactate dehydrogenase released from the TG hearts. The extent of infarction and apoptotic cell death was also significantly decreased, which was associated with increased protein ratio of Bcl-2/Bax and reduced caspase-3 activity in TG hearts. Furthermore, in vivo experiments of 30-minute myocardial ischemia, via coronary artery occlusion, followed by 24-hour reperfusion, showed that the infarct region–to–risk region ratio was 8.1±1.1% in TG hearts (n=7), compared with 19.5±2.1% in WT hearts (n=11,
P
<0.001).

Conclusions—

Our data demonstrate that increased Hsp20 expression in the heart protects against I/R injury, resulting in improved recovery of cardiac function and reduced infarction. Thus, Hsp20 may constitute a new therapeutic target for ischemic heart diseases.
Mouse Model of
SCN5A
-Linked Hereditary Lenègre’s Disease
Authors: Royer Anne , van Veen Toon A.B. , Le Bouter Sabrina , Marionneau Céline , Griol-Charhbili Violaine , Léoni Anne-Laure , Steenman Marja , van Rijen Harold V.M. , Demolombe Sophie , Goddard Catharine A. , Richer Christine , Escoubet Brigitte , Jarry-Guichard Thérèse , Colledge William H. , Gros Daniel , de Bakker Jacques M.T. , Grace Andrew A. , Escande Denis , Charpentier Flavien
Published: April 2005

Background—

We have previously linked hereditary progressive cardiac conduction defect (hereditary Lenègre’s disease) to a loss-of-function mutation in the gene encoding the main cardiac Na
+
channel,
SCN5A
. In the present study, we investigated heterozygous
Scn5a
-knockout mice (
Scn5a
+/−
mice) as a model for hereditary Lenègre’s disease.

Methods and Results—

In
Scn5a
+/−
mice, surface ECG recordings showed age-related lengthening of the P-wave and PR- and QRS-interval duration, coinciding with previous observations in patients with Lenègre’s disease. Old but not young
Scn5a
+/−
mice showed extensive fibrosis of their ventricular myocardium, a feature not seen in wild-type animals. In old
Scn5a
+/−
mice, fibrosis was accompanied by heterogeneous expression of connexin 43 and upregulation of hypertrophic markers, including β-MHC and skeletal α-actin. Global connexin 43 expression as assessed with Western blots was similar to wild-type mice. Decreased connexin 40 expression was seen in the atria. Using pangenomic microarrays and real-time PCR, we identified in
Scn5a
+/−
mice an age-related upregulation of genes encoding Atf3 and Egr1 transcription factors. Echocardiography and hemodynamic investigations demonstrated conserved cardiac function with aging and lack of ventricular hypertrophy.

Conclusions—

We conclude that
Scn5a
+/−
mice convincingly recapitulate the Lenègre’s disease phenotype, including progressive impairment with aging of atrial and ventricular conduction associated with myocardial rearrangements and fibrosis. Our work provides the first demonstration that a monogenic ion channel defect can progressively lead to myocardial structural anomalies.
Differential Aspects of Endothelial Function of the Coronary Microcirculation Considering Myocardial Virus Persistence, Endothelial Activation, and Myocardial Leukocyte Infiltrates
Authors: Vallbracht Katja B. , Schwimmbeck Peter L. , Kühl Uwe , Rauch Ursula , Seeberg Bettina , Schultheiss Heinz-Peter
Published: April 2005

Background—

Viral cardiomyopathy resulting from myocardial virus persistence can be associated with inflammatory immune responses that involve the myocardium and coronary blood vessels. The aim of this study was to investigate the differential impact of myocardial virus persistence and inflammation on endothelial function of the coronary microcirculation.

Methods and Results—

In 71 patients with nonischemic cardiomyopathy, myocardial biopsies were examined for virus persistence (by polymerase chain reaction) and inflammation (by immunohistology). Endothelial function of the coronary microcirculation was examined during heart catheterization by measuring diameter (by quantitative coronary angiography) and velocity changes (by intracoronary Doppler) of the left anterior descending artery in response to acetylcholine. Coronary blood flow (CBF) was calculated. Endothelium-independent vasoreactivity to adenosine was assessed. Mean age of the patients (37 men, 34 women) was 43±13 years; mean ejection fraction was 64±11%. In 43 patients, adenovirus, enterovirus, parvovirus, or HHV-6 was detected; 28 had no virus. Endothelial function of the coronary microcirculation was significantly impaired in patients with myocardial virus persistence (V) compared with patients without virus (Co) (ΔCBF-V, 22±86%; ΔCBF-Co, 110±113%;
P
=0.001), which was confirmed in 51 patients with myocardial inflammation (MC) (32 with virus, 19 with no virus) (ΔCBF-MC-V, 12±89%; ΔCBF-MC-Co, 81±109%;
P
=0.034) and in 20 patients with normal immunohistology of the myocardial biopsies (Co) (11 with virus, 9 with no virus) (ΔCBF-Co-V, 51±72%; ΔCBF-Co-Co, 175±97%;
P
=0.006). Endothelial function of the coronary microcirculation was also significantly impaired in patients with myocardial inflammation/endothelial activation compared with patients without inflammatory immune response. Endothelium-independent vasodilation was not influenced significantly.

Conclusions—

Myocardial virus persistence and myocardial inflammation/endothelial activation are associated with endothelial dysfunction of the coronary microcirculation. Endothelial dysfunction in patients with myocardial virus persistence can occur independently of myocardial inflammation/endothelial activation but is more pronounced in patients with concurrent inflammation.
Prognostic Value of Ambulatory and Home Blood Pressures Compared With Office Blood Pressure in the General Population
Authors: Sega Roberto , Facchetti Rita , Bombelli Michele , Cesana Giancarlo , Corrao Giovanni , Grassi Guido , Mancia Giuseppe
Published: April 2005

Background—

Studies in hypertensive patients suggest that ambulatory blood pressure (BP) is prognostically superior to office BP. Much less information is available in the general population, however. Obtaining this information was the purpose of the Pressioni Arteriose Monitorate e Loro Associazioni (PAMELA) study.

Methods and Results—

Office, home, and 24-hour ambulatory BP values were obtained in 2051 subjects between 25 and 74 years of age who were representative of the general population of Monza (Milan, Italy). Subjects were followed up for an average of 131 months, during which time cardiovascular and noncardiovascular fatal events were recorded (n=186). Office, home, and ambulatory BP values showed a significant exponential direct relationship with risk of cardiovascular or all-cause death. The goodness of fit of the relationship was greater for systolic than for diastolic BP and for night than for day BP, but its overall value was not better for home or ambulatory than for office BP. The slope of the relationship, however, was progressively greater from office to home and ambulatory BP. Home and night BP modestly improved the goodness of fit of the risk model when added to office BP.

Conclusions—

In the PAMELA population, risk of death increased more with a given increase in home or ambulatory than in office BP. The overall ability to predict death, however, was not greater for home and ambulatory than for office BP, although it was somewhat increased by the combination of office and outside-of-office values. Systolic BP was almost invariably superior to diastolic BP, and night BP was superior to day BP.
Near-Infrared Fluorescent Imaging of Matrix Metalloproteinase Activity After Myocardial Infarction
Authors: Chen Jiqiu , Tung Ching-Hsuan , Allport Jennifer R. , Chen Si , Weissleder Ralph , Huang Paul L.
Published: April 2005

Background—

We used a molecular probe activated by protease cleavage to image expression of matrix metalloproteinases (MMPs) in the heart after myocardial infarction.

Methods and Results—

We synthesized and characterized a near-infrared fluorescent (NIRF) probe that is activated by proteolytic cleavage by MMP2 and MMP9. The NIRF probe was injected into mice at various time points up to 4 weeks after myocardial infarction induced by ligation of the left anterior descending coronary artery. NIRF imaging of MMP activity increased in the infarct region, with maximal expression at 1 to 2 weeks, persisting to 4 weeks. Zymography and real-time polymerase chain reaction analysis showed that MMP9 expression is increased at 2 to 4 days, and MMP2 expression is increased at 1 to 2 weeks. Dual-label confocal microscopy showed colocalization of NIRF imaging with neutrophils on day 2, and flow cytometric analysis confirmed that NIRF signal is associated with leukocytes in the infarct zone.

Conclusions—

This study demonstrates that the activity of MMPs in the myocardium may be imaged by use of specific activity–dependent molecular probes.
Systematic Review of Combined Angiotensin-Converting Enzyme Inhibition and Angiotensin Receptor Blockade in Hypertension
Authors: Doulton Timothy W.R. , He Feng J. , MacGregor Graham A.
Published: April 2005

Some evidence suggests that long-term angiotensin-converting enzyme (ACE) inhibition may become less effective, thereby increasing angiotensin II levels, which could be inhibited by the addition of an angiotensin receptor blocker. We conducted a meta-analysis of randomized trials with searches of MEDLINE, EMBASE, and Cochrane databases. Overall, the combination of an ACE inhibitor and an angiotensin receptor blocker reduced ambulatory blood pressure by 4.7/3.0 mm Hg (95% confidence interval [CI], 2.9 to 6.5/1.6 to 4.3) compared with ACE inhibitor monotherapy and 3.8/2.9 mm Hg (2.4 to 5.3/0.4 to 5.4) compared with angiotensin receptor blocker monotherapy. Clinic blood pressure was reduced by 3.8/2.7 mm Hg (0.9 to 6.7/0.8 to 4.6) and 3.7/2.3 mm Hg (0.4 to 6.9/0.2 to 4.4) compared with ACE inhibitor and angiotensin receptor blocker, respectively. However, the majority of these studies used submaximal doses or once-daily dosing of shorter-acting ACE inhibitors and, when a larger dose of shorter-acting ACE inhibitor was given or a longer-acting ACE inhibitor was used, there was generally no additive effect of the angiotensin receptor blocker on blood pressure. Proteinuria was reduced by the combination compared with ACE inhibitor and angiotensin receptor blocker monotherapy, an effect that was independent of blood pressure in several studies, suggesting that the combination could have benefits in proteinuric nephropathies. None of the studies was of sufficient size and duration to determine whether there may be safety concerns. In conclusion, although there is a small additive effect on blood pressure with an ACE inhibitor-angiotensin receptor blocker combination, the routine use of this combination in uncomplicated hypertension is not recommended until more carefully controlled studies are performed.
Autosomal Genome Scan for Loci Linked to Blood Pressure Levels and Trends Since Childhood
Authors: Chen Wei , Li Shengxu , Srinivasan Sathanur R , Boerwinkle Eric , Berenson Gerald S.
Published: April 2005

Genetic loci influencing the long-term levels and trends of blood pressure over time were investigated using 775 white siblings, ages 13 to 43 years, enrolled in the Bogalusa Heart Study, and 357 microsatellite markers on the 22 autosomal chromosomes. Subjects had been examined serially 2 to 12 times with 4365 serial observations over an average of 22 years from childhood to adulthood. Total and incremental area under the curve was calculated based on a cubic growth curve and used as long-term levels and trends, respectively. After adjusting for age, sex, and body mass index, heritability estimates of total area were 0.66 for systolic and 0.68 for diastolic blood pressure. Heritability of incremental area was 0.38 for systolic and 0.46 for diastolic blood pressure. Significant linkage to the total area of diastolic blood pressure (peak logarithm of odds [LOD]=3.9 at 73 cM) was observed on chromosome 2, with a region spanning from 44 cM to 103 cM showing supporting linkage evidence of LOD >3.0. In addition, suggestive linkage for total area of systolic (LOD=1.6 at 182 cM) and diastolic blood pressure (LOD=2.0 at 36 cM) on chromosome 4 and diastolic blood pressure incremental area (LOD=2.2 at 28 cM) on chromosome 18 was noted. Several hypertension candidate genes such as α-adducin, β-adducin, sodium bicarbonate co-transporter, and G protein-coupled receptor kinase 4 are located in these regions. Linkage evidence found in this community-based study indicates that regions on these chromosomes harbor genetic loci that affect the propensity for development of hypertension from childhood.
High-Salt Diet Inhibits Expression of Angiotensin Type 2 Receptor in Resistance Arteries
Authors: Gonzalez Magdalena , Lobos Lorena , Castillo Felipe , Galleguillos Lorna , Lopez Nandy C. , Michea Luis
Published: April 2005

Recent studies suggested that type 2 angiotensin receptor (AT2R) could contribute to regulation of blood pressure and/or vascular remodeling. A key question relates to the effects of potential modulators of vascular AT2R expression. In the present work, we evaluated if high salt intake (70 mmol/L NaCl in drinking water) could modulate rat mesenteric artery AT2R function and expression. Angiotensin II dose-response curves were studied in rat perfused pressurized small-diameter arteries in the presence of losartan (AT1R antagonist). Arteries were precontracted with phenylephrine, yielding ≈30% decrease in resting diameter. AT2R activation by angiotensin-induced dose-dependent relaxation of precontracted arteries (60.1±9.1% of phenylephrine-induced contraction,
P
<0.05). In contrast, AT2R-dependent relaxation was not observed in arteries obtained from rats on high-salt diet. Semi-quantitative reverse-transcription polymerase chain reaction experiments demonstrated reduced amount of AT2R mRNA in arteries of rats on high-salt diet (65.5±7.5% of control levels,
P
<0.05). Western blot studies demonstrated decreased AT2R in mesenteric artery protein fractions of high-salt diet rats (60.0±18.0 of control levels,
P
<0.05). In a second set of experiments, adrenalectomy (4 days) blunted AT2R-mediated vasorelaxation and decreased AT2R mRNA (72.0±11.0% of control levels,
P
<0.05). AT2R abundance in protein fractions of mesenteric arteries of ADX rats was also diminished (64.0±13% of control levels,
P
<0.05). Both, AT2R mRNA and protein downregulation were prevented by mineralocorticoid replacement therapy. Finally, physiological concentrations of aldosterone caused a dose-dependent increase in AT2R mRNA of small diameter mesenteric artery explants. The results are consistent with aldosterone-mediated upregulation AT2R.
A New Transgenic Rat Model of Hepatic Steatosis and the Metabolic Syndrome
Authors: Qi Nathan R. , Wang Jiaming , Zidek Vaclav , Landa Vladimir , Mlejnek Petr , Kazdová Ludmila , Pravenec Michal , Kurtz Theodore W.
Published: April 2005

Fatty liver is extremely common in insulin-resistant patients with either obesity or lipodystrophy and it has been proposed that hepatic steatosis be considered an additional feature of the metabolic syndrome. Although insulin resistance can promote fatty liver, excessive hepatic accumulation of fat can also promote insulin resistance and could contribute to the pathogenesis of the metabolic syndrome. We sought to create a new nonobese rat model with hypertension, hepatic steatosis, and the metabolic syndrome by transgenic overexpression of a sterol-regulatory element-binding protein (SREBP-1a) in the spontaneously hypertensive rat (SHR). SREBPs are transcription factors that activate the expression of multiple genes involved in the hepatic synthesis of cholesterol, triglycerides, and fatty acids. The new transgenic strain of SHR overexpressing a dominant-positive form of human SREBP-1a under control of the phosphoenolpyruvate carboxykinase (PEPCK) promoter exhibited marked hepatic steatosis with major biochemical features of the metabolic syndrome, including hyperglycemia, hyperinsulinemia, and hypertriglyceridemia. Both oxidative and nonoxidative skeletal muscle glucose metabolism were significantly impaired in the SHR transgenic strain and glucose tolerance deteriorated as the animals aged. The SHR transgenic strain also exhibited reduced body weight and reduced adipose tissue stores; however, the level of hypertension in the transgenic SHR was similar to that in the nontransgenic SHR control. The transgenic SHR overexpressing SREBP-1a represents a nonobese rat model of fatty liver, disordered glucose and lipid metabolism, and hypertension that may provide new opportunities for studying the pathogenesis and treatment of the metabolic syndrome associated with hepatic steatosis.
African American Women Principals’ Reflections on Social Change, Community Othermothering, and Chicago Public School Reform
Authors: Loder Tondra L.
Published: April 2005

Emphasizing the salience of social and historical contexts in understanding contemporary urban school leadership, this article presents reflections from a subset of African American women principals who came of age during the Civil Rights era and assumed leadership subsequent to the enactment of the Chicago School Reform Act of 1988. The main finding being reported is that the unique race, gender, and generational statuses of these principals made them especially vulnerable to the impact of governance reforms that rearranged long-standing authority relationships between African American principals and parents. Implications for urban school leadership research and policy are discussed.
This Test is Unfair
Authors: Walpole Marybeth , McDonough Patricia M. , Bauer Constance J. , Gibson Carolyn , Kanyi Kamau , Toliver Rita
Published: April 2005

This qualitative study explored the perceptions of, knowledge regarding, and preparation for standardized college admissions exams of 227 urban African American and Latino high school students. Findings include the students’lack of information about the test and their reliance on their relatively uninformed and unavailable school officials for information, preparation strategies, strategies for achieving high scores, stress level due to the necessity of high test scores, and beliefs that the tests are an unfair obstacle. Students’knowledge of and strategies for preparing and taking the tests are conceptualized as cultural capital and habitus utilizing a Bourdieuian framework.
A Meta-Analysis of the Relation of Parental Involvement to Urban Elementary School Student Academic Achievement
Authors: Jeynes William H.
Published: April 2005

This meta-analysis of 41 studies examines the relationship between parental involvement and the academic achievement of urban elementary school children. Analyses determined the effect sizes for parental involvement overall and subcategories of involvement. Results indicate a significant relationship between parental involvement overall and academic achievement. Parental involvement, as a whole, was associated with all the academic variables by about 0.7 to 0.75 of a standard deviation unit. This relationship held for White and minority children and also for boys and girls. The significance of these results is discussed.
City Size in Late Postclassic Mesoamerica
Authors: Smith Michael E.
Published: April 2005

This article assembles archaeological and documentary evidence on the sizes of cities in Mesoamerica on the eve of Spanish conquest. Out of several hundred documented Late Postclassic urban centers, eighty-seven have reliable archaeological data on the area of the total city and/or the area of the central administrative zone (called the epicenter). The median urban area is 90 hectares (ha), and the median epicenter is 2.0 ha. These data are analyzed in terms of geographical zone, political type, population size and density, and rank-size distributions. The results suggest that political and administrative factors were the primary determinants of city size, with geographical zone having only a minor influence.
The Use of Water and its Regulation in Medieval Siena
Authors: Kucher Michael
Published: April 2005

The Tuscan hill town of Siena, Italy, has been supplied by a system of gravity-fed fountains since at least the twelfth century. Medieval statutes and surviving physical evidence reveal that the city maintained the purity of its urban water supply by a combination of physical and legal structures. The urban water supply embodied the provisions of that legislation in the physical arrangements of the fountain complexes. Laws and architecture imposed a hierarchy whereby those uses of water with greater potential for contamination were kept downstream from the uses that required a supply of pure water. Although not unique to Siena, the city’s hierarchal division of water provides a powerful and useful model for allocating contemporary water resources.
A Line Drawn in the Water
Authors: Myllyntaus Timo
Published: April 2005

Historians tend to lack an integral view of the major factors of the physical world. The separation of phenomena according to disciplinary traditions is a general custom. Usually, historians pay attention to the interplay between technology and the physical environment only when something extraordinary takes place or when things do not work in an expected way. This article examines the significance of water in human history and past interactions between technology and water issues. Humanity has used technology to govern, control, and subdue water. Nevertheless, water and the environment in general have not yielded entirely to human domination. It is claimed that the maltreatment of the natural world contains a risk of environmental backlash. Some droughts, floods, salinization, and waterborne diseases are examples of human-induced environmental problems. Water-related environmental issues illustrate the close connection between environmental history and the history of technology, which are as interconnected as the two sides of a coin.
Seasonal Variation in the Environmental Effects of Toll Collection
Authors: Peters Jonathan R. , Kramer Jonathan K.
Published: April 2005

The toll collection process creates pollution beyond what would be produced by an automobile transiting at normal highway speeds. Research shows that electronic toll collection (ETC) produces less pollution than manual toll collection. However, many toll collection systems are subject to seasonal fluctuations in demand. As a result, the percentage of road users taking advantage of ETC changes throughout the year. Any decrease in the ETC participation rate will increase the amount of pollution created. This article quantifies the pollution effects of this seasonality. The authors use the Garden State Parkway (GSP) in New Jersey as a case study. Because of seasonal changes in ETC participation rates, they find that the quantity of pollution created by toll collection on the GSP increases significantly during the summer months. Unfortunately for the state of New Jersey, that is the time of year when it is historically in noncompliance with the Clean Air Act.
Transportation Policy in the European and American Unions Compared
Authors: Gordon Cameron
Published: April 2005

This is an article about two intertwined topics: federalism and transportation. It is also an article about two intertwined unions (in a political, economic, and cultural sense at least): the European Union and the United States of America. Transportation policy making in the two “unions” is compared and some potential lessons about how to best organize central government transportation policy are drawn out.
Revisiting Transportation Planning
Authors: Ankner William D.
Published: April 2005

Transportation planning in most states and cities is failing to plan for multi modal transportation systems and is often politically driven. Planners are continuing to do project planning. This essay proposes a new direction for transportation planning based on transportation trip purpose(s) and market sheds/corridors. The five trip purposes:journey to work, goods movement, tourism, economic generators and community travel. Understanding travel purposes in the market sheds will allow transportation planners to integrate these purposes into transportation systems, irrespective of mode, to meet the market needs. Our transportation infrastructure is a costly investment. We need to make smarter transportation investment decisions. We can no longer remain intolerant to our customer’s purpose(s) for transportation. We need to understand the market and its relationship to economic and social goals to better plan our transportation system.
Public Participation
Authors: Tennille Cheryl L.
Published: April 2005

The combination of government process, ownerships rights, and violation of land use turns public participation into city rights versus citizens rights. When citizens experience the exploitive manner of incompatible development and irreversible expansion, contrary to the dictates of historic preservation law according to the Home Rule Act of the District of Columbia, they rightfully expect a recourse and fair review process from its regulatory agencies, legislative branch, and executive branch of city government. Citizens coalesce, divide into task groups, and create a record of evidence supporting their opposition and a record of city procedures. When this monitoring and scrutiny uncovers suspicions of political patronage and underhandedness, an applicant to build digs in its heels. The opposition stiffens, and the court seems the likely arbiter to enforce appropriate standards of conduct among the city’s regulatory agencies. Enforcement then sets a citywide precedent for lawful accountable land use for all parts of the District of Columbia.
Are NBA Fans Becoming Indifferent to Race? Evidence From the 1990s
Authors: Burdekin Richard C. K. , Hossfeld Richard T. , Smith Janet Kiholm
Published: April 2005

Previous work found the racial composition of NBA teams to be positively correlated with the racial composition of their metropolitan markets in the 1980s. We find continued evidence of this relationship during the 1990s, with accompanying revenue gains from the inclusion of White players on teams located in whiter areas. And, as the number of White players declined significantly throughout the decade, the revenue product of a White player actually increased on the margin. The tendency for top-performing White players in the NBA to locate in cities with larger White populations also is consistent with their higher marginal value in such locations.
Big-Time Pigskin Success
Authors: Tucker Irvin B.
Published: April 2005

This article uses a combination of measures of big-time football success not examined in previous studies. Using updated data between 1990 and 2002 and adjusting for key academic variables, this article tested whether there is statistical evidence that SAT scores are influenced by success in a high-quality football program. Contrary to other publications that found a weak advertising effect or no advertising effect before 1990, the finding of this research is that there is a robust statistically significant positive impact for successful football teams during recent years on the quality of incoming freshmen, beginning with the incoming freshmen class of 1996. Hence, a strong athletic success advertising effect or positive externality does indeed exist for football after the formation of the bowl alliance in 1995.
When Is the Honeymoon Over? National Basketball Association Attendance 1971-2000
Authors: Leadley John C. , Zygmont Zenon X.
Published: April 2005

This article uses a Tobit analysis to test for the presence of a honeymoon effect for National Basketball Association (NBA) arenas using a pooled cross-section time series sample from 1971 to 2000. No previous NBA attendance-demand or attendance-related study tested for such an effect. The honeymoon effect increases attendance demand 15% to 20% in the first 4 years of the operation of a new arena, an increase that is similar in magnitude to recently constructed Major League Baseball stadiums. The effect is nonlinear and diminishes relatively quickly with the steady state established after Year 10. Because many NBA arenas are subsidized, the effect has public policy implications if revenue projections for a new arena ignore or overestimate the effect.
Overtime! Rules and Incentives in the National Hockey League
Authors: Easton Stephen T. , Rockerbie Duane W.
Published: April 2005

We construct a simple 2-period game model to determine the effects of recent National Hockey League rule changes on team incentives to win. The effects differ depending on the relative quality of the contestants and whether the contestants compete in the same conference. The model predicts that the average number of points during a season will rise, yet the average point differential among clubs within the same conference will fall. The model also predicts that the expected value of points per contest will be higher when playing nonconference opponents but lower when playing conference opponents. Because only a small percentage of contests are nonconference, we predict that more effort will be devoted to conference contests, particularly by lesser-talented clubs. The result is more competitive and exciting conference games requiring fewer overtime periods and potential ties. Empirical data support these hypotheses.