Variable effects of cardiomyoplasty on left ventricular function

Renin-angiotensin system promotes sodium and chloride retention, participates in the defense response to hypovolemia and, in congestive heart failure, contributes to edema formation and progression of the disease. We investigated whether ACE-inhibitors interfere with the action of the renin-angiotensin system on the nephron, and therefore with water and urinary electrolytes excretion. The interaction among renin-angiotensin system, diuretic treatment and urinary electrolytes was evaluated both during chronic treatment and in response to acute renin-angiotensin system activation as that observed after extracorporeal ultrafiltration-induced transient hypovolemia. Plasma renin activity and aldosterone, body fluid balance and urinary sodium, chloride and potassium concentrations were evaluated in 30 patients with congestive heart failure in NYHA II-III functional class, grouped according to whether long-term therapy did not include (Group I, n = 15) or included (Group II, n = 18) ACE-inhibitors. All parameters were evaluated at baseline and after a single session of extracorporeal ultrafiltration. At baseline, urinary output and urinary sodium and chloride concentrations were similar in the two groups, while urinary potassium concentration was lower in patients assuming ACE-inhibitors (Group II). Plasma renin activity was higher and aldosterone was lower in Group II than in Group I. After removal of similar amounts of plasma water by extracorporeal ultrafiltration, body weight decreased in both groups but the decrease was maintained in the following days only in Group II patients. A transient reduction (48 hours) of both plasma volume and urinary output was observed after ultrafiltration in both groups. Despite plasma renin activity and aldosterone increase, urinary electrolytes response to ultrafiltration was different in the two groups: sodium and chloride were reduced, and potassium did not change in Group 1 while, in Group II, sodium and chloride did not change and potassium excretion was significantly increased. In conclusion, chronic treatment with ACE-inhibitors does not enhance the excretion of sodium in congestive heart failure but just mitigates potassium loss. The role of these drugs becomes particularly relevant during acute renin-angiotensin system activation due to hypovolemia; in this setting ACE-inhibitors counteract sodium and chloride retention resulting in a potential hazard due to interference with the defence mechanisms toward hypovolemia, and an amplification of extracorporeal ultrafiltration efficacy by preventing edema recovery after its mechanical removal.     

Torsional properties of stainless steel and nickel-titanium endodontic files

American cutaneous leishmaniasis (ACL) presents a spectrum of clinical and immunological manifestations. Since the nature of the cellular response appears to play a fundamental role in determining the characteristics of the immunoglobulin isotype of specific antibody responses, we have compared the relative levels of specific antibodies of the four IgG isotypes against Leishmania in sera from patients with different clinical manifestations of ACL. Using a specific antibody capture assay, significant levels of antibodies of the IgG1, 2 and 3 isotypes were detected in localized cutaneous leishmaniasis (LCL); the average level of IgG4 antibodies was low and they were not detected in 10/20 sera. Sera from muco-cutaneous leishmaniasis (MCL) gave a comparatively strong IgG1 response. Sera from diffuse cutaneous leishmaniasis (DCL), the rare form characterized by antigen-specific anergy of cell-mediated immunity, showed highly significant levels of IgG4 antibodies compared to antibody levels of this isotype in the other groups; IgG1 and IgG2 levels were also elevated. Based on other studies of the relationship between the IgG isotype response and cell-mediated immunity, these results confirm a Th1-like CD4+ T cell response in LCL and MCL and a significant Th2-like response in DCL.     

The effect of articulatory suppression on short-term recognition.

Exp 1 determined whether articulatory suppression (AS) affected mainly α (initial strength) or φ (influence of later items) in a short-term recognition task, using 12 female undergraduates. Exp 2, with 12 undergraduates, indicated that the degree to which trace-strength was reduced by an incoming target item varied with what was spoken in the context of the AS task. Findings show that if d′ was used to measure strength in an immediate recognition task, AS of any kind reduced encoding strength as compared with normal voicing. It is concluded that AS exerted its effects by preoccupying short-term store with extraneous material, one effect being that intralist rehearsal was prevented. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sulfonated polyisobutylene telechelic ionomers

The gelation of polyisobutylene-based model ionomers with-S0₃ ^–K⁺ terminal groups has been studied in hexane at 25°C. Both molecular architecture and molecular weight were found to significantly influence the concentration at which gelation occurs. Specifically, three-arm star trifunctional ionomers gel at lower concentrations than linear difunctional ionomers of similar molecular weight. In addition, the gelation concentration decreases with increasing molecular weight for the three-arm star trifunctional ionomer, but the results do not fit the relationship reported previously which relates gelation concentration and molecular weight for carboxylated linear telechelic polymers.     

A geometric performance assessment of the EO-1 advanced land imager

The Earth Observing 1 (EO-1) Advanced Land Imager (ALI) demonstrates technology applicable to a successor system to the Landsat Thematic Mapper series. A study of the geometric performance characteristics of the ALI was conducted under the auspices of the EO-1 Science Validation Team. This study evaluated ALI performance with respect to absolute pointing knowledge, focal plane sensor chip assembly alignment, and band-to-band registration for purposes of comparing this new technology to the heritage Landsat systems. On-orbit geometric calibration procedures were developed that allowed the generation of ALI geometrically corrected products that compare favorably with their Landsat 7 counterparts with respect to absolute geodetic accuracy, internal image geometry, and band registration.     

Effects of oxygen, positive end-expiratory pressure, and carbon dioxide on oxygen delivery in an animal model of the univentricular heart

OBJECTIVE: Respiratory manipulations are a mainstay of therapy for infants with a univentricular heart, but until recently little experimental information has been available to guide their use. We used an animal model of a univentricular heart to characterize the physiologic effects of a number of commonly used ventilatory treatments, including altering inspired oxygen tension, adding positive end-expiratory pressure, and adding supplemental carbon dioxide to the ventilator circuit. RESULTS: Lowering inspired oxygen tension decreased the ratio of pulmonary to systemic flow. This ratio was 1.29 +/- 0.08 at an inspired oxygen tension of 100%, 0.61 +/- 0.09 at an inspired oxygen tension of 21%, and 0.42 +/- 0.09 at an inspired oxygen tension of 15% (p < 0.05 compared with an inspired oxygen tension of 100% and a positive end-expiratory pressure of 0 cm H2O). High-concentration supplemental carbon dioxide (carbon dioxide tension of 80 to 90 mm Hg) added to the ventilator circuit decreased inspired oxygen tension from 1.29 +/- 0.11 to 0.42 +/- 0.12 (p < 0.05 compared with baseline). A mixture of 95% oxygen and 5% carbon dioxide (carbon dioxide tension of 50 to 60 mm Hg) did not decrease the pulmonary/systemic flow ratio significantly. All three types of interventions influenced systemic oxygen delivery, which was a function of the pulmonary/systemic flow ratio. As the pulmonary/systemic flow ratio decreased from initially high levels (greater than 1), oxygen delivery first increased and reached an optimum at a flow ratio slightly less than 1. As the pulmonary/systemic flow ratio decreased further, below 0.7, oxygen delivery decreased. The ability of systemic arterial and venous oxygen saturations to predict the pulmonary/systemic flow ratio was examined. Venous oxygen saturation correlated well with both pulmonary/systemic flow ratio and systemic oxygen delivery, whereas arterial oxygen saturation did not accurately predict either pulmonary/systemic flow ratio or oxygen delivery. CONCLUSION: This model demonstrated the value of estimating the pulmonary/systemic flow ratio before initiating therapy. When the initial ratio was greater than about 0.7, interventions that decreased the ratio increased oxygen delivery and were beneficial. When the initial pulmonary/systemic flow ratio was below 0.7, interventions that decreased the ratio decreased oxygen delivery and were detrimental. We conclude by presenting a framework to guide therapy based on the combination of arterial and venous oxygen saturations and the estimate of the pulmonary/systemic flow ratio that they provide.     

Training Psychology Interns in Primary Behavioral Health Care.

This article describes a training program for primary behavioral health care (PBHC) for clinical psychology interns. The authors discuss the rationale for integrating mental health into primary care and the need for additional training programs at the predoctoral internship level. A review of relevant literature suggests that effective functioning in primary care requires competence in (a) generalist psychology, (b) health psychology, (c) interdisciplinary team functioning, and (d) skills specific to primary care. The authors advocate for a relatively intensive training program to address these areas. Common intern training difficulties observed during 3 years of program implementation are discussed. Practical, lessons-learned recommendations that address these problem areas provide guidance for others seeking to develop a PBHC training program. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Animal rights, a bitten apple.

Comments on H. A. Herzog's (see record 1996-13937-001) examination of media coverage to determine trends in the animal rights movement from 1976–1994. The authors argue that Herzog's measure of visibility is too narrow and that the decline in coverage observed in periodicals and major newspapers may reflect a consolidation of, rather than a decline in, the movement's influence. Some additional observations and ideas about the animal rights movement's place in society based on a broader range of assessments of popular culture (e.g., music, film, television, donor support) are offered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)