Regulation of oxygen delivery during induced polycythemia in exercising dogs.

Previous studies have concluded that polycythemia decreases oxygen delivery primarily because of a large fall in cardiac output associated with a rise in systemic vascular resistance that has been attributed to increased blood viscosity. However, because other studies have shown that polycythemia may not reduce oxygen delivery, an alternative hypothesis is that cardiac output falls in response to a rising oxygen content, thereby maintaining oxygen delivery constant. To determine whether oxygen content participates in the regulation of cardiac output during polycythemia, we studied eight chronically instrumented dogs trained to exercise on a treadmill.

Combined pulmonary stenosis and insufficiency preserves myocardial contractility in the developing heart of growing swine at midterm follow-up.

This study was conducted to determine the effects of chronic combined pulmonary stenosis and pulmonary insufficiency (PSPI) on right (RV) and left ventricular (LV) function in young, growing swine. Six pigs with combined PSPI were studied, and data were compared with previously published data of animals with isolated pulmonary insufficiency and controls. Indexes of systolic function (stroke volume, ejection fraction, and cardiac functional reserve), myocardial contractility (slope of the end-systolic pressure-volume and change in pressure over time-end-diastolic volume relationship), and diastolic compliance were assessed within 2 days of intervention and 3 mo later.

[MRI of pulmonary arteries in follow-up after arterial-switch-operation (ASO) for transposition of great arteries (d-TGA)].

Purpose: To determine the value of MRI in postoperative evaluation of patients with arterial-switch-operation (ASO) for d-TGA.

Material And Methods: 14 consecutive patients with d-TGA and ASO were examined with MRI in addition to ultrasound because the acoustic window in echocardiography was insufficient. Nine patients had a pulmonary-artery-bifurcation anterior to the aortic root (group 1), and five (group 2) laterally (two of them left, three of them right).

Magnetic resonance in systems with equivalent spin-1/2 nuclides. Part 1.

Electron paramagnetic resonance (EPR) spectra of S=1/2 systems XL(n) with n equivalent nuclei having spin I=1/2 have been simulated for microwave frequencies in the L-, X-, and W-bands. It has been shown that for n>2 nuclei, the EPR spectra have a more complicated form than anticipated from the usual oversimplified analysis, which predicts n+1 lines with intensity ratios given by the coefficients of the binomial expansion. For the XL(n) system with n=3, the EPR spectra in fact consist of six lines.

Prevalence of hepatitis B surface antigen in vaccinated children and controls in rural Nigeria.

Objective: To determine the prevalence of hepatitis B surface antigen (HBsAg) amongst vaccinated children and controls aged 1-4 years in a rural community in mid-western Nigeria.

Methods: The vaccinated children had received at least three doses of hepatitis B vaccine. The vaccines included recombinant hepatitis B vaccine at birth and a combined diphtheria, tetanus, pertussis (whole cell) plus hepatitis B (DTPw-HBV) vaccine.

Increasing prevalence of multidrug-resistant Streptococcus pneumoniae in the United States over a 10-year period: Alexander Project.

The Alexander Project is a global surveillance study conducted from 1992 to 2001. Minimum inhibitory concentrations and percent resistance to a panel of antimicrobial agents were determined according to National Committee for Clinical Laboratory Standards methodology. Resistance to penicillin (PEN-R) and erythromycin (ERY-R) have increased in the period 1992-2001 by 3.

Snapshot of the substance abuse treatment workforce in 2002: a synthesis of current literature.

Substance abuse among adolescents and adults continues to be a major public health concern. Given the prevalence of substance use, abuse, and dependence in the United States, the treatment needs of the population who abuse substances are great. Adolescents and adults who abuse substances need competent, knowledgeable, and qualified staff to provide services to meet their treatment needs.

Incidence of fractures among epilepsy patients: a population-based retrospective cohort study in the General Practice Research Database.

Purpose: To compare the incidence of various fractures in a cohort of patients with epilepsy with a reference cohort of patients not having epilepsy.

Methods: Patients were included in the epilepsy cohort if they had at least one diagnosis of epilepsy in their medical history and had sufficient evidence of "active" epilepsy (use of antiepileptic drugs, diagnoses) after the practice was included in the General Practice Research Database (GPRD). Two reference patients were sampled for each patient with epilepsy from the same practice.

Peer review: an essential step in the publishing process.

Among the many steps involved in publishing a professional paper, peer review of the submitted manuscript presents both a challenge and an opportunity. Peer review is essential to ensuring that published papers meet appropriate research, scholarship and journal criteria. Peer review is also a valuable resource, providing detailed, professional evaluations that help authors carry out and present scholarship of the highest quality.

Cultural considerations in understanding family violence among Asian American Pacific Islander families.

There has been much research conducted in the area of family violence, however, there is a paucity of research specifically addressing family violence in Asian American and Pacific Islander (AAPI) communities. Because AAPIs are regarded as the model minority, many have the misconception that family violence does not exist in this population. This article examines Asian cultural beliefs and values to gain a better understanding of Asian attitudes towards family violence.

Pro-angiogenic signaling by the endothelial presence of CEACAM1.

Here, we demonstrate the expression of carcinoembryonic antigen-related cell adhesion molecule-1 (CEACAM1) in angiogenic sprouts but not in large mother blood vessels within tumor tissue. Correspondingly, only human microvascular endothelial cells involved in in vitro tube formation exhibit CEACAM1. CEACAM1-overexpressing versus CEACAM1-silenced human microvascular endothelial cells were used in migration and tube formation assays.

Catheter visualization with resonant markers at MR imaging-guided deployment of endovascular stents in swine.

Purpose: To evaluate resonant circuits as markers for magnetic resonance (MR) imaging-guided placement of nitinol stents.

Materials And Methods: The study was approved by the institutional animal research committee and complied with National Institutes of Health guidelines for care and use of laboratory animals. Resonant circuits similar to catheter markers used at conventional angiography were placed proximally and distally to a nitinol stent in a stent delivery system.

Sleep at high altitude.

New arrivals to altitude commonly experience poor-quality sleep. These complaints are associated with increased fragmentation of sleep by frequent brief arousals, which are in turn linked to periodic breathing. Changes in sleep architecture include a shift toward lighter sleep stages, with marked decrements in slow-wave sleep and with variable decreases in rapid eye movement (REM) sleep.

Ross-Konno procedure in neonates: report of three patients.

The Ross-Konno procedure, applied to neonates with severe left ventricular outflow tract (LVOT) obstruction, offers a satisfactory solution in fully releasing the LVOT gradient, and in replacing the aortic valve with a pulmonary autograft with an excellent growth potential. We reported on three recent neonatal cases.

Norepinephrine upregulates vascular endothelial growth factor in rat cardiac myocytes by a paracrine mechanism.

Norepinephrine has growth-promoting effects in cardiac myocytes. The present study in cultured neonatal rat cardiac myocytes tested the hypothesis that norepinephrine also stimulates expression of vascular endothelial growth factor (VEGF), an important angiogenic factor. As assessed by polymerase chain reaction cardiac myocytes and non-myocytes expressed all three isoforms of rat VEGF, with the short isoform (VEGF 121 ) preferentially expressed in non-myocytes.

Ross and Ross-Konno procedure in children and adolescents: mid-term results.

Objectives: The aim of the study was to analyze mid-term results of aortic root replacement with pulmonary autograft in children and adolescents in two centers.

Methods: From December 1997 through August 2003, a total of 66 patients underwent the Ross procedure in two centers. Indication for Ross procedure was predominantly aortic stenosis in 24 patients and predominantly aortic regurgitation (AR) in 22 patients.

Oral L-arginine and vitamins E and C improve endothelial function in women with type 2 diabetes.

Endothelial dilator function is impaired in people with type 2 diabetes mellitus (T2DM). Prior research indicates that this can be improved with intravenous administration of ascorbate or L-arginine, but whether these agents have this effect when administered by the clinically practical oral route is unknown. To investigate this question, 10 premenopausal women with T2DM and 10 healthy, premenopausal, non-diabetic women received, in random sequence, a 1-week administration of oral L-arginine (9 g daily) or vitamins E (1800 mg) and C (1000 mg) with an intervening 1-week washout period.

[MRI of congenital heart disease in childhood].

MRI provides a non-invasive diagnostic tool complementing echocardiography on one hand, and showing advantages over echocardiography, on the other hand, especially after corrective procedures. The multiple different MRI sequences need to be adapted to examinations of children and patients with congenital heart disease (CHD), and can be used to detect morphologic changes, blood-flow in the heart and thoracic vessels and diastolic or systolic function of myocardium. Several factors determine the success of the examination of a complex congenital heart disease or a postoperative situs.

Myocardial hypertrophy and enhanced left ventricular contractility in Zucker diabetic fatty rats.

Heart failure is known to be a complication of insulin-dependent (IDDM) and noninsulin-dependent diabetes mellitus (NIDDM) even in the absence of coronary heart disease or hypertension. The mechanisms leading to diabetic cardiomyopathy are unknown. The aim of the study was to characterize structural and functional alterations in hyperinsulinemic Zucker diabetic fatty (ZDF) rats treated with or without insulin.

Psychosocial genetic counseling in the post-nondirective era: a point of view.

For three decades nondirectiveness has served as the central ethos for genetic counseling. It has evolved from narrow definitions defining what should not be done to broad definitions that promote active counseling skills in support of client autonomy and informed decision making. As broad definitions have been formulated, the term "nondirective" has become largely irrelevant to their content; it persists primarily as a historic relic.

Nonocclusive mesenteric ischemia induced by digitalis.

Background: Nonocclusive mesenteric ischemia is a rare but serious disorder with a high mortality rate; causal factors include cardiac glycosides, digoxin, and digitoxin in addition to severe hypotension, decompensated heart failure, and septic shock.

Case Presentation: We present a patient with digitoxin intoxication who died from autopsy-confirmed ischemic gangrenous colitis.

Conclusion: Despite the frequent occurrence of intoxication with cardiac glycosides nonocclusive mesenteric ischemia is a rare event.

Plasma concentrations of aminoterminal pro atrial natriuretic peptide and aminoterminal pro brain natriuretic peptide in healthy neonates: marked and rapid increase after birth.

Objective: The purpose of the study was to examine the possible age dependency of plasma N-terminal pro atrial natriuretic peptide (N-ANP) and N-terminal pro brain natriuretic peptide (N-BNP) levels in healthy term neonates to establish normal ranges for the neonatal period.

Methods: N-ANP and N-BNP plasma concentrations were measured in peripheral venous (n = 116) and umbilical cord blood (n = 37) in 153 healthy term neonates (mean: 5.1; range: 0-30 days) using an enzyme immunoassay.