Impaired immune responsiveness in Plasmodium berghei immune mice

Mice immunized against Plasmodium berghei parasites by drug-controlled infection exhibited decreased immunoresponsiveness against rabbit red blood cells (RRBC). Increasing RRBC antigen dose increased responsiveness, but agglutinating anti-RRBC antibodies of the IgG class remained undetectable. Clearance of colloidal carbon from the bloodstream of malaria-immunized mice was not different from controls. Removal of all the persistent parasites from immune mice did not restore responsiveness until 140 days after treatment, suggesting that the parasite per se did not influence responsiveness directly. Because of this, and because of the fact that priming of mice with RRBC before P. berghei immunization was not more effective than priming after immunization, it was concluded that antigen uptake and subsequent presentation were not impaired in P. berghei immune mice, in contrast to infected mice. Anti-RRBC antibodies were detected in serum of P. berghei immune mice, but regulation of responsiveness to RRBC by transfer of such immune mouse serum was not found. Immunoglobulin levels, especially of the IgG2 and IgG3 subclass were elevated in sera of P. berghei immune mice, which indicated an LPS-like polyclonal activation. The results also suggest that during drug-controlled infection, which leads to immunity against infection, a state of B-cell tolerance is induced.     

Dipyridamole thallium imaging may not be a reliable screening test for coronary artery disease in patients undergoing vascular surgery

Dipyridamole thallium imaging has been proposed for cardiac risk stratification in patients undergoing peripheral vascular surgery. The purpose of this study was to define the benefit of this investigation in routine preoperative evaluation of these patients. The outcome of 86 patients undergoing vascular surgery procedures was examined in light of preoperative clinical assessment and dipyridamole SPECT thallium imaging (DST). Fifty-one patients (59%) were considered at high risk on clinical grounds, and 22 patients (26%) had perfusion defects. Ten patients suffered a perioperative coronary event, including unstable angina, myocardial infarction, or cardiac death. Seven of the patients with such events were among the 51 clinically high-risk subjects (14%). Three perioperative events occurred in the group of 19 patients with positive DST images who underwent surgery (16%), but the DST test failed to identify 7 patients who suffered coronary events. The frequency of abnormal thallium imaging was similar to the prevalence of angiographically significant coronary disease reported previously at this center, but considerably less than the rate of abnormal thallium imaging in past studies of vascular surgery patients. The application of the test to a low to moderate risk population is probably responsible for its lower predictive accuracy for coronary events. DST is not an ideal routine noninvasive technique for risk stratification in patients undergoing vascular surgery.     

Noninvasive strategies for the estimation of cardiac risk in stable chest pain patients. The Economics of Noninvasive Diagnosis (END) Study Group

Effective allocation of medical resources in stable chest pain patients requires the accurate diagnosis of coronary artery disease and the stratification of future cardiac risk. We studied the relative predictive value for cardiac death of 3 commonly applied noninvasive strategies, clinical assessment, stress electrocardiography, and myocardial perfusion tomography, in a large, multicenter population of stable angina patients. The multicenter observational series comprised 7 community and academic medical centers and 8,411 stable chest pain patients. All patients underwent pretest clinical screening followed by stress (exercise 84% or pharmacologic 16%) electrocardiography and myocardial perfusion tomography. Risk-adjusted multivariable Cox proportional hazards models were developed to predict cardiac death. Kaplan-Meier rates of time to cardiac catheterization were also computed. Cardiac mortality was 3% during the 2.5 +/- 1.5 years of follow-up. The number of infarcted vascular territories and pretest clinical risk factors were strong predictors of cardiac mortality, whereas the number of ischemic vascular territories gained increasing importance when determining post-test resource use requirements (i.e., the decision to perform cardiac catheterization). Exertional ST-segment depression in a population with a high frequency of electrocardiographic abnormalities at rest was not a significant differentiator of cardiac death risk. Stable chest pain patients are accurately identified as being at high risk for near-term cardiac events by both physicians' screening clinical evaluation and by the results of stress myocardial perfusion imaging. Disease management strategies for stable chest pain patients aimed at risk reduction should incorporate knowledge of relevant end points in treatment and guideline development.     

Prolonged impact of home versus clinic-based management of chronic heart failure: Extended follow-up of a pragmatic,multicentre randomized trial cohort

Objectives

We compared the longer-term impact of the two most commonly applied forms of post-discharge management designed to minimize recurrent hospitalization and prolong survival in typically older patients with chronic heart failure (CHF).

Methods

We followed a multi-center randomized controlled trial cohort of Australian patients hospitalized with CHF and initially allocated to home-based or specialized CHF clinic-based intervention for 1368 ± 216 days. Blinded endpoints included event-free survival from all-cause emergency hospitalization or death, all-cause mortality and rate of all-cause hospitalization and stay.

Results

280 patients (73% male, aged 71 ± 14 years and 73% left ventricular systolic dysfunction) were initially randomized to home-based (n = 143) or clinic-based (n = 137) intervention. During extended follow-up (complete for 274 patients), 1139 all-cause hospitalizations (7477 days of hospital stay) and 121 (43.2%) deaths occurred. There was no difference in the primary endpoint; 20 (14.0%) home-based versus 13 (7.4%) clinic-based patients remained event-free (adjusted HR 0.89, 95% CI 0.70 to 1.15; p = 0.378). Significantly fewer home-based (51/143, 35.7%) than clinic-based intervention (71/137, 51.8%) patients died (adjusted HR 0.62, 95% CI 0.42 to 0.90: p = 0.012). Home-based versus clinic-based intervention patients accumulated 592 and 547 all-cause hospitalizations (p = 0.087) associated with 3067 (median 4.0, IQR 2.0 to 6.8) versus 4410 (6.0, IQR 3.0 to 12.0) days of hospital stay (p < 0.01 for rate and duration of hospital stay).

Conclusions

Relative to clinic-based intervention, home-based intervention was not associated with prolonged event-free survival. Home-based intervention was, however, associated with significantly fewer all-cause deaths and significantly fewer days of hospital stay in the longer-term.

Trial registration

Australian New Zealand Clinical Trials Registry number 12607000069459 (http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=81803)     

Effect of tissue Doppler on the accuracy of novice and expert interpreters of dobutamine echocardiography.

The subjective interpretation of dobutamine echocardiography (DBE) makes the accuracy of this technique dependent on the experience of the observer, and also poses problems of concordance between observers. Myocardial tissue Doppler velocity (MDV) may offer a quantitative technique for identification of coronary artery disease, but it is unclear whether this parameter could improve the results of less expert readers and in segments with low interobserver concordance. The aim of this study was to find whether MDV improved the accuracy of wall motion scoring in novice readers, experienced echocardiographers, and experts in stress echocardiography, and to identify the optimal means of integrating these tissue Doppler data in 77 patients who underwent DBE and angiography. New or worsening abnormalities were identified as ischemia and abnormalities seen at rest as scarring. Segmental MDV was measured independently and previously derived cutoffs were applied to categorize segments as normal or abnormal. Five strategies were used to combine MDV and wall motion score, and the results of each reader using each strategy were compared with quantitative coronary angiography. The accuracy of wall motion scoring by novice (68 +/- 3%) and experienced echocardiographers (71 +/- 3%) was less than experts in stress echocardiography (88 +/- 3%, p <0.001). Various strategies for integration with MDV significantly improved the accuracy of wall motion scoring by novices from 75 +/- 2% to 77 +/- 5% (p <0.01). Among the experienced group, accuracy improved from 74 +/- 2% to 77 +/- 5% (p <0.05), but in the experts, no improvement was seen from their baseline accuracy. Integration with MDV also improved discordance related to the basal segments. Thus, use of MDV in all segments or MDV in all segments with wall motion scoring in the apex offers an improvement in sensitivity and accuracy with minimal compromise in specificity.     

Therapy in a subtropical climate for children with cerebral palsy. Evidence of physical and psychosocial effects?

Aim: To assess a possible therapeutic effect in children and adolescents with cerebral palsy of a habilitation programme in a warm sunny climate.
Methods: Fifty-seven children and adolescents with cerebral palsy, all integrated with normal functioning children through mainstream schooling, received an individualized four-week habilitation programme at a habilitation centre in Lanzarote in the Canary Islands. They were clinically assessed before and after treatment, and again after three and six months. The clinical tests included gross motor function measure (GMFM) and the paediatric evaluation of disability inventory (PEDI). Mental health and self-esteem were assessed by using the youth self report (YSR), the child behaviour checklist (CBCL) and the Harter's self-perception profile. We also used focus-group interviews on all 57 parents by the end of the treatment period.
Results: The study revealed some improvements in the level of physical performance. The most striking finding, however, was the lasting effect on behavioural and emotional parameters and the children's self-esteem.
Conclusion: Training in a warm climate may explain some of this positive effect. However, based on the focus-group interviews and its quantitative findings a more plausible explanation may be the interaction in a social setting with others in a similar situation.     

Unit cost of Mohs and Dermasurgery Unit

Background Appropriate pricing for medical services of not‐for‐profit hospital is necessary. The prices should be fair to the public and should be high enough to cover the operative costs of the organization. Objective The purpose of this study was to determine the cost and unit cost of medical services performed at the Mohs and Dermasurgery Unit (MDU), Department of Dermatology, The University of Texas – MD Anderson Cancer Center, Houston, TX from the healthcare provider’s perspective. Methods MDU costs were retrieved from the Financial Department for fiscal year 2006. The patients’ statistics were acquired from medical records for the same period. Unit cost calculation was based on the official method of hospital accounting. Results The overall unit cost for each patient visit was $673.99 United States dollar (USD). The detailed unit cost of nurse visit, new patient visit, follow‐up visit, consultation, Mohs and non‐Mohs procedure were, respectively, $368.27, $580.09, $477.82, $585.52, $1,086.12 and $858.23 USD. With respect to a Mohs visit, the unit cost per lesion and unit cost per stage were $867.89 and $242.30 USD respectively. Conclusions Results from this retrospective study provide information that may be used for pricing strategy and resource allocation by the administrative board of MDU.     

Autologous bone marrow transplantation in children with acute lymphoblastic leukemia

We report 25 children with acute lymphoblastic leukemia (ALL) treated with purged autologous bone marrow transplantation (ABMT) at a single center. Two children with high-risk ALL were transplanted in first remission and 23 with relapsing ALL were transplanted in second (n = 21) or third (n = 2) remission. There was no procedure-related mortality. The median time to engraftment (i.e. to reach a polymorphonuclear cell count of 0.5 x 10(9)/l) was 25 days (range 16-45 days). Seven children relapsed, four within five months after ABMT: 18 of 25 children (72%) are in continuous complete remission after a median follow-up period of 50 months (range 5-71 months). The predicted long-term disease-free survival is 65% in the whole group and 61% in those transplanted after relapse. Relapse-free children returned to normal activities within three months after ABMT. The major side effects were development of cataract and gonadal insufficiency. We consider the results promising, but our data do not allow comparison with results reported from treatment with chemotherapy alone, since some of our patients were referred from other centers and represent a selected patient group. Long-term follow-up of well-defined patient populations is necessary to evaluate the effect of ABMT.