bluuebunny/crossref_metadata_2025_split huggingface dataset:
Failure to Demonstrate Beneficial Effect of Prostacyclin (PGI2) Infusion on Red Blood Cell Deformability in Patients with Peripheral Vascular Disease: A Possible Role of the Leukocytes
Authors: Parise Pasquale , Berrettini Mauro , Grasselli Serenella , de Cunto Maria , Nenci Giuseppe Giorgio 
Published: November 2007

The effect of prostacyclin (PGI2) on red blood cell deformability is still con troversial. The authors have evaluated some hemorrheologic parameters during PGI2 infusion to patients with severe obstructive peripheral arterial disease not suitable for surgery and not responsive to other medical treatments. PGI2 infu sion resulted in a positive clinical effect in 12 of 16 patients, who experienced a significant improvement of their rest pain lasting from two days to more than seven months. Hematocrit, platelet count, and fibrinogen were not modified during PGI2 infusion whereas leukocyte count rose significantly. The evaluation of red blood cell filterability (VRBC) (volume of RBC filtered in one minute) by a whole blood filtration technique showed no significant changes during PGI 2 treatment. However, since whole blood filterability is nega tively correlated to leukocyte count, a specific regression line was elaborated to remove the potential negative influence of the increased leukocyte counts. VRBC values adjusted to a standard leukocyte number significantly increased during PGI2 treatment.
The Exchange Transfusion
Authors: Pochedly Carl 
Published: November 2007

The aims of an exchange transfusion— removal of sensitized red cells, removal of excessive bilirubin and Rh antibodies, and the correction of anemia—have not changed over the years. Morbidity and mortality rates are low, due primarily to better training of pediatricians and to advances in instrumen tation and technic. This article reviews basic principles and current technics in exchange transfusion.
Concomitant Rheumatic Fever and Acute Glomerulonephritis
Authors: Chandrasekhara M.K. , Cornfeld D. 
Published: November 2007

Concomitant rheumatic fever and acute post-streptococcal glomerulonephritis sometimes do occur simultaneously, with clinical features not notably different from those seen in children who have either disorder separately. Differential recognition presents a neat clinical challenge.
Factor VIII Related Antigen (von Willebrand's Factor) In Kawasaki Disease
Authors: Irazuzta Jose E. , Elbl Francisco , Rees Allan R. 
Published: November 2007

Kawasaki disease is a systemic vasculitis in which secondary development of coronary artery aneurysms can occur. Because Factor VIII related antigen has been found increased in other vasculiditides, VIII R:Ag was measured serially in patients with Kawasaki disease. Factor VIII related antigen was prospectively evaluated in the acute phase of ten patients with Kawasaki disease, all of whom showed increased values at this stage (p > 0001). In six children a second sample was drawn at the convalescent phase, and all were normal. Of the original ten patients, two developed coronary artery aneurysms. Acute Factor VIII related antigen levels were not higher nor did Factor VIII related antigen fail to return to baseline in these two patients. Based on our findings, Factor VIII related antigen is elevated in the acute phase of Kawasaki disease and returns to normal levels in the convalescent phase.
Antenatal Fetal Diagnosis and Maternal Transport Gastroschisis
Authors: Carlan Stephen J. , Knuppel Robert A. , Perez J. , Flasher Jackie 
Published: November 2007

Gastroschisis is a rare congenital birth defect of the abdominal wall that invariably is fatal if not managed appropriately. Early in utero diagnosis is now possible using maternal serum alpha-fetoprotein and ultrasound. As with other serious congenital disorders, antenatal diagnosis allows therapeutic options and time for preparation. Even if the diagnosis is made late, however, efforts to achieve prenatal maternal transport are still reasonable. The neonatal outcome of an unplanned delivery of an anomalous child requiring immediate attention is likely to be better if the delivery occurs in a tertiary center. These facilities generally have specialized services and teams available for critical care around the clock. The authors describe the maternal transport and delivery of a neonate with a serious disorder that required specialized attention at an hour when most hospitals are staffed with a skeleton crew. The necessary resources were available immediately, and the neonatal outcome was favorable. Although this report describes gastroschisis specifically, the concept of tertiary site delivery for potentially seriously ill neonates applies to any condition. With a late diagnosis, possible other anomalies, and a logistically unfavorable hour, the advantages of maternal transport are evident. This report also briefly reviews the area of antenatal ultrasound diagnosis and the newer mechanisms used to develop a perinatal care plan.
Late Holocene sea-level changes from grain-size data: evidence from the Gulf of Mexico
Authors: Tanner William F. 
Published: November 2007

Grain-size kurtosis of sand in the beach ridge plain of St. Vincent Island, Florida, is numerically reasonably uniform within any one ridge set, but changes at important set boundaries. Where these changes are found, there are also differences in air photo and field appearance and in measured ridge-set heights. Sets with low kurtosis (∼3.0) stand topographically high, and sets with higher values (∼3.6) stand low. Study of wave energy levels and beach sand grain-size kurtosis along modem Gulf of Mexico beaches shows that kurtosis is an inverse function of surf-zone energy density. Storms and storminess (for the study area) can be evaluated in the framework of the selective- transport model of May (1973); the actual data sequence is greatly different from what is required by the model, and therefore storms and storminess cannot be invoked to explain the history of the area. Instead, the data sequence matches results predicted by the model for small sea-level changes. Storms and tectonism do not have appropriate durations and rates of operation, hence did not cause changes in kurtosis across St. Vincent Island. Slow land elevation changes (warping, isostatic adjustment) do not take place repeatedly up and down like the granulometric parameters. Tidal effects, in the study area, are both much too small and too frequent to have been important. The changes in kurtosis therefore indicate water level changes, and provide a sea-level history, including three sea level drops and four rises, of 1-3 m each, since about 3000 BP. Similar results have been obtained elsewhere, so these results are not local.
The climate of the last 2000 years in southern Africa
Authors: Tyson P.D. , Lindesay J.A. 
Published: November 2007

Until recently, relatively little was known of the exact nature of climatic change in southern Africa over the past two millennia. New research based on oxygen isotope analyses of cave speleothems and mollusc remains in shell middens, together with foraminifera studies of inshore marine deposits, palynological and micromammalian research and earlier dendrochronological work, has allowed more reliable identification of the effects of the 'Little Ice Age' in the subcontinent. Cooling prevailed from 1300 to 1850 with a warm episode occurring between about 1500 and 1675. In addition, the generally warmer period from about 900 to 1300 may have been associated with the Medieval Warm Epoch. Earlier distinctive events appear to have been a variable period of cooling from 600 to 900, a warmer period from about AD 250 to 600 and a notable interval of cooling between AD 100 and 200. Much of the evidence for the 'Little Ice Age' in southern Africa suggests that in the summer rainfall region drier conditions prevailed during the period of cooling. At the same time the winter rainfall region became wetter. This supports a previous postulation that as the tropical easterlies of the general circulation of the atmosphere strengthen and become more perturbed over southern Africa over extended periods, so the climate becomes wetter over the summer rainfall area. As the circumpolar westerlies strengthen and expand northward, so the summer rainfall region becomes drier, while the coastal Mediterranean winter rainfall region becomes wetter.
An 8000-year record of sea-level change from grain-size parameters: data from beach ridges in Denmark
Authors: Tanner William F. 
Published: November 2007

The low-energy beach ridge system near the town of Jerup, in the extreme north of Denmark, was sampled at 154 sites, on a pattern of one per ridge (intervals of 50-51 years, starting about 7800 BP). None of these ridges was built by storm waves or by wind. They are not like high-energy ridges to the north, which differ in size, morphology, bedding and granulometry. In the low-energy system, sand grain-size kurtosis (inverted) is a reliable index of wave energy density in the surf zone, and also indicates an important component of settling. Kurtosis tends to be more-or-less constant in sets of 5-20 ridges, then to change abruptly at set boundaries, which therefore represent sea- level changes (1-5 m), centuries apart. The sixth moment measure (grain size) and ridge spacing also indicate sea-level change. Glacio-isostatic rebound has averaged 2 to 2.1 mm yr-1 for this system; the history of this rebound plots best on a semi-log diagram showing a decrease from about 4 mm yr-1 (at 6000 BP) to about 1.3 mm yr-1 (at 1000 BP). The Jerup sea-level curve matches the Gulf of Mexico curve as far back as the latter goes. Each provides sea level history in the 'Little Ice Age' (most recent millennium), and other changes since 3000 BP; the Jerup curve shows earlier fluctuations. The largest changes were in the range 3-5 m; maximum rates were about 1 cm yr-1 .
Long-term Treatment With Pravastatin Alone and in Combination With Gemfibrozil in Familial Type IIB Hyperlipoproteinemia or Combined Hyperlipidemia
Authors: Napoli Claudio , Lepore Stefano , Chiariello Paola , Condorelli Mario , Chiariello Massimo 
Published: November 2007

Background: Pravastatin inhibits 3-hydroxy-3-methylglutaryl-coenzyme A reductase. It pre vents mevalonate synthesis, reducing endogenous cholesterol production, and reduces cholesterol content in the liver, thus resulting in a down-regulation of low-density lipoprotein receptor production. Gemfibrozil reduces very low-density lipoprotein production and low- density lipoprotein-cholesterol level and increases very low-density lipoprotein catabolism. Therefore, it was suggested that combination therapy with both drugs could effect greater reduction of cholesterol levels as compared to pravastatin alone. The present study was car ried out to evaluate the efficacy and safety of pravastatin as a monotherapy or in combination with gemfibrozil in the treatment of patients with familial type IIb hyperlipoproteinemia or familial combined hyperlipidemia. Methods and Results: Forty-one patients were included in the study. All patients initially followed 6 weeks of hypolipidemic diet; subsequently they were randomized and received either 20 mg once daily of pravastatin alone (n = 13) or 20 mg of pravastatin together with 600 mg of gemfibrozil twice daily (n = 14). As a control, 14 patients were treated with diet only. The treatment lasted 24 months and clinical evaluation and laboratory tests were done at given time points. Both groups of treated patients showed an early reduction (3 months) of total (about 30% P < .0 vs controls), low-density lipoprotein (about 35%, P < .0 vs con trols) and very low-density lipoprotein cholesterol levels (about 18%, P = NS). In contrast, high-density lipoprotein cholesterol levels increased significantly in patients treated with pravastatin and gemfibrozil (about 20%, P < .05 vs controls). Pravastatin treatment alone reduced the level of serum triglycerides as efficiently as in combination with gemfibrozil. Data showed a sustained normalization of lipid profile until 24 months. However, this effect was achieved in patients that had rather low levels of triglycerides. During the treatment we did not observe any difference in the incidence of possible drug-related side effects. Severe myopathy or rhabdomyolysis was not observed at the doses of the drugs used in our study. Conclusions: Therapy with pravastatin alone and in combination with gemfibrozil resulted in significant and sustained normalization of lipid profile in high-risk patients with familial type lib hyperlipoproteinemia or familial combined hyperlipidemia.
Modulation of the Electrophysiologic Actions of E-4031 and Dofetilide by Hyperkalemia and Acidosis in Rabbit Ventricular Myocytes
Authors: West Paul D. , Martin Donald K. , Bursill Jane A. , Wyse Kenneth R. , Campbell Terence J. 
Published: November 2007

Background: E-4031 and dofetilide are new class III antiarrhythmic agents that inhibit the rapid component of the delayed rectifier potassium channel (IKr); however, the effectiveness of many antiarrhythmic drugs in ischemic conditions is uncertain. Methods and Results: We modeled two components of ischemia, hyperkalemia (9.6 mM) and acidosis (pH 6.8), in voltage-clamped single rabbit ventricular myocytes to help deter mine the effect of ischemia on the action of these two drugs. In physiologic solution both E- 4031 and dofetilide blocked IKr and significantly reduced total outward current. In hyper kalemic solution, both E-4031 and dofetilide showed significantly reduced blockade of IKr, while in acidotic solution dofetilide showed significantly reduced blockade of IKr and E-4031 showed a trend to reduced blockade. Neither drug significantly reduced total outward current in hyperkalemic or acidotic solutions. Conclusions: In these conditions, E-4031 and dofetilide demonstrate reduced blockade of I Kr, resulting in loss of class III effect. Furthermore, the complete loss of blocking effect on total outward current during simulated ischemia suggests increases of other repolarizing cur rents also contribute to loss of class III effect.
Atorvastatin, a New HMG-CoA Reductase Inhibitor, Does Not Affect Glucocorticoid Hormones in Patients with Hypercholesterolemia
Authors: Isaacsohn Jonathan L. , Bakker-Arkema Rebecca G. , Fayyad Rana , Whitcomb Randall , Black Donald M. 
Published: November 2007

Background: Atorvastatin calcium (Lipitor) is a new 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor. The present study was conducted to examine the effect of pronounced cholesterol lowering on adrenal function in patients with severe hypercholes terolemia. Methods and Results: Adrenal function was examined under basal conditions and following adrenal corticotropin hormone stimulation in 40 patients (36 with heterogeneous familial and 4 with polygenic hypercholesterolemia). The study was part of a larger study comparing the efficacy and safety of atorvastatin, colestipol, atorvastatin + colestipol, and simvastatin + colestipol treatment over a 1-year period. Maximum doses of all agents were studied: 80 mg atorvastatin once daily, 40 mg simvastatin once daily, and 20 g/day colestipol. At the end of the 1-year treatment period, reductions in low-density lipoprotein cholesterol were 57%, 54%, and 49% for the atorvastatin, colestipol + atorvastatin, and colestipol + simvastatin groups, respectively. No clinically significant changes in basal serum cortisol levels were seen in any treatment group during the 1-year treatment period. Mean serum cortisol concen trations and area under the curve for cortisol concentration versus time data following adrenal corticotropin hormone stimulation were not clinically different during treatment compared with values obtained at baseline for any of the treatment groups. Conclusions: Treatment with maximum doses of atorvastatin for 1-year did not have any adverse effects on adrenal function under basal conditions or during maximum stimulation. Similarly, colestipol therapy alone and in combination with either atorvastatin or simvastatin did not appear to affect adrenal function.
Frequency-dependent Cardiac Electrophysiologic Effects of Tedisamil: Comparison With Quinidine and Sotalol
Authors: Németh Miklós , Varró András , Virág László , Hála Ottó , Thormählen Dirk , Gyula Papp Julius 
Published: November 2007

Background: Tedisamil is a potent bradycardic/antiischemic drug known to lengthen car diac repolarization by blocking various potassium channels. Recent in vivo experiments revealed that it is an antiarrhythmic agent. It was therefore of interest to compare the cellu lar electrophysiologic effects of tedisamil with those of quinidine and sotalol in isolated car diac preparations. Methods and Results: The conventional microelectrode technique was applied in isolated dog cardiac Purkinje and ventricular muscle fibers and in rabbit left atrial muscle. Tedisamil (1 μM) and sotalol (30 μM) lengthened, while quinidine (10 μM) shortened action potential duration in dog Purkinje fibers. The phase 1 repolarization was delayed by tedisamil and quinidine and not changed by sotalol. In dog ventricular muscle and in rabbit atrial muscle, all three drugs studied lengthened repolarization. In dog Purkinje fiber, tedisamil and sotalol lengthened action potential duration more at slow than at high stimulation frequency (reverse use-dependence). In dog ventricular muscle fibers, the effect of the drugs was not clearly fre quency dependent. In rabbit atrial muscle fibers, the quinidine-evoked repolariration length ening was most pronounced at intermediate cycle lengths (500-1000 ms). Tedisamil and quinidine but not sotalol depressed the maximal rate of depolarization (Vmax), which depended on the stimulation frequency (use-dependence). The nature of the use-dependent Vmax block differed between quinidine and tedisamil. Quinidine decreased Vmax at a relatively wide range of stimulation frequencies while tedisamil decreased Vmax largely at high rate of stimulation. Tedisamil and quinidine prevented or decreased the pinacidil-evoked action potential shortening in dog ventricular muscle, suggesting block of the ATP-dependent potas sium channels (IKATP), while with sotalol such effect was not observed. Conclusions: Although tedisamil, quinidine. and sotalol are known to lengthen the QT inter val, their cellular electrophysiologic effects substantially differ. Tedisamil lengthens repolar ization and prevents pinacidil-evoked action potential duration shortening, suggesting IK(ATP) blockade. Its effect on the Vmax is limited mostly to fast heart rate. These electrophysiologic effects of tedisamil resemble those of chronic amiodarone treatment.
Review : Recent Advances in the Prevention of Coronary Artery Disease: Focus on Primary Prevention
Authors: Sudhir Krishnankutty 
Published: November 2007

Background: Several new strategies for prevention of coronary artery disease have emerged. This review examines the various approaches to primary prevention, and some aspects of secondary prevention. Methods and Results : The role of aspirin, beta-blockers, exercise, diets, fish intake, vitamin E, and folic acid are discussed. The potential role of chlamydia in atherosclerosis, the pro tective effect of alcohol consumption, and the benefits of female sex hormones are also examined. An update on lipid-lowering therapy, and a summary of the recent major clinical trials establishing the use of 3-hydroxy-3-methylgluataryl-coenzyme A reductase inhibitors in primary and secondary prevention of coronary artery disease, are provided. Conclusions: An aggressive approach to medical management of coronary artery disease a substantial reduction in risk.
Mechanisms of Impaired Endothelial Function Associated with Insulin Resistance
Authors: Miller Allison Winecoff , Hoenig Margarethe E. , Ujhelyi Michael R. 
Published: November 2007

Background: The insulin-resistant (IR) syndrome is causally related to hypertension and cardiovascular events; however, the underlying mechanism remains elusive. The current study was designed to determine (1) whether the IR syndrome causes vascular dysfunction and (2) whether insulin resistance alters the activity of the individual endothelium-derived relaxing factors. Methods and Results: Insulin resistance was induced in Sprague-Dawley rats by a 4-week fructose-rich diet. Subsequently, mesenteric arteries (~250 μM) were removed from control and 1R rats, and intraluminal diameter was used to assess vascular response to pharmaco logical probes. Studies with sodium nitroprusside showed that vascular relaxation did not differ between IR and control groups. In contrast, maximal vascular relaxation to acetylcho line (10 -9 to 10-4 mol/L) in phenylephrinc preconstricted arteries was decreased in the IR group (44 ± 4%) versus control (89 ± 5%) ( P < .01). N-nitro-L-arginine (LNNA) pretreat ment further impaired acetylcholine-induced maximal relaxation in the IR group from 44 ± 4% to 12 ± 3%; P < .01. In control rats, maximal relaxation was only slightly impaired by the addition of LNNA (89 ± 5% to 68 ± 6%; P <.05). The addition of indomethacin to ace tylcholine did not affect maximal relaxation in either group. When potassium chloride (KCl) was used for preconstriction, relaxation to acetylcholine in the IR group was similar to that found with phenylephrine preconstriction (41 ± 4% v 44 ± 4%, respectively); how ever, KCl preconstriction significantly decreased acetylcholine-induced relaxation in con trol rats (89 ± 5% to 43 ± 5%; P > .01). Conclusion: Insulin resistance impairs endothelium-dependent relaxation in small mesen teric arteries. It appears that insulin resistance transforms the primary relaxant factor from endothelial-derived hyperpolarizing factor to nitric oxide. These findings suggest that hyper tension and atherosclerosis associated with the IR syndrome are caused, at least in part, by endothelial dysfunction.
Risk Factors for Tachycardia Events Caused by Antiarrhythmic Drugs: Experience From the ESVEM Trial
Authors: Sharma Param P. , Ott Peter , Hartz Vernon , Mason Jay W. , Marcus Frank I. 
Published: November 2007

Background: In the Electrophysiology Study versus Electrocardiographic Monitoring (ESVEM) trial, up to seven antiarrhythmic drugs were randomly assigned to 486 patients with a history of sustained ventricular arrhythmia. At baseline, all the patients had inducible sustained ventricular tachycardia (VT) and had ≥10 premature ventricular beats (PVBs) per hour on 48-hour Holter monitoring. A total of 1,229 drug trials were performed. Antiar rhythmic drugs were discontinued during hospitalization because of ventricular tachy arrhythmias thought to be a proarrhythmic effect of the antiarrhythmic drugs in 96 of 479 patients (20%) who received drugs. Proarrhythmic effects were defined as sustained VT, ventricular fibrillation or arrhythmic death, torsade de pointes, or distinct intolerable wors ening of the baseline arrhythmia after at least three doses of the drug. Methods and Results: Eighteen baseline characteristics were analyzed for factors that would predict a higher incidence of proarrhythmia. These included type of heart disease, previous myocardial infarction, symptom activity scale, gender, type of arrhythmia, VT/ ventricular fibrillation, age, left ventricular ejection fraction (LVEF), PVB frequency, heart rate, QRS duration, and QT interval. Multiple logistic regression analysis identified increased mean PVB frequency ( P = .003) and increased heart rate ( P = .026) as significant predic tors of proarrhythmia. Decreased LVEF (<25%) exhibited only a trend toward significance ( P = .073). When proarrhythmia was redefined as sustained VT, cardiac arrest or arrhyth mic death, or torsade de pointes (n = 59), PVB frequency ( P = .003) and heart rate ( P = .034) were still the only significant baseline predictors. Conclusion: In the ESVEM study, higher PVB frequency and higher heart rate were signif icant predictors of drug-induced proarrhythmia.