The impact of a policy of collaborative management on mortality and morbidity from infective endocarditis

The present study represents a comprehensive retrospective review of endocarditis in a large district general hospital since the inception of a formalized policy involving collaborative management a decade ago. The principle was to involve a recognised team of cardiologists, specialists in infectious disease and microbiologists in the treatment of the disease from the moment of its diagnosis. The pattern of infection has not altered in terms of prevalent organisms and valves infected since the change in management policy. There has, however, been a significant decline in the mortality, from 34 to 24% for all patients with endocarditis. Amongst those referred for collaborative management, the mortality has fallen to 6%. The single greatest improvement is a reduction in the number of patients dying of heart failure, the number of patients developing systemic emboli or requiring prosthetic valve replacement remaining unchanged. The results indicate that early referral to, and treatment by, a multidisciplinary team can significantly reduce the mortality from bacterial endocarditis.     

Electrode recovery potential

In some instances the same electrodes are used for stimulation and then for recording a bioelectric event immediately after the stimulus. However, after the current pulse there remains an electrode potential that decays quasiexponentially. We have designated this falling potential the electrode-recovery potential. This study investigated the recovery potentials of single electrodes of rhodium, stainless steel, platinum and platinum-iridium in contact with 0.9% saline at room temperature (25°C) over a current density ranging from 0.1 to 100 mA/cm² using a constant-current pulse. In all cases, with increasing current density, there was a decrease in the time for the electrode potential to fall to one half of the immediate post-stimulus value. Above about 20 mA/cm² the decrease in recovery time was smooth with increasing current density. Below 20 mA/cm², the recovery time was slightly irregular. The shortest recovery times were for platinum and platinum-iridium. The largest decrease in recovery time with increasing current density was for stainless steel, which decreased 10 fold from 0.1 to 100 mA/cm². The recovery time for rhodium decreased about three-and-one half fold over the same current density range. It was found that the waveform of the recovery potential is not a simple exponential because the Warburg and Faradic components of the electrode-electrolyte interface are current-density dependent. In general, for all current densities studied (0.1–100 mA/cm²), there was a sudden initial fall in electrode potential with cessation of current flow, followed by a very gradual nonexponential decrease in potential.     

Ion transport characteristics of the murine trachea and caecum.

1. The basic defect in cystic fibrosis relates to abnormalities of ion transport in affected tissues, such as the respiratory and gastrointestinal tracts. The identification of the cystic fibrosis gene has enabled studies on the production of a cystic fibrosis transgenic mouse to be undertaken. Knowledge of normal ion transport will be necessary for the validation of any such animal model. We have therefore characterized selected responses of the murine trachea and caecum mounted in 'mini' Ussing chambers under open-circuit conditions. 2. Basal values for the trachea were: potential difference, 1.1 mV (SEM 0.2; n = 18); equivalent short-circuit current, 20.4 microA/cm2 (3.6); conductance, 18.2 mS/cm2 (1.7). Corresponding values for the caecum were: potential difference, 0.7 mV (0.1; n = 18); equivalent short-circuit current, 11.0 microA/cm2 (1.6); conductance, 14.5 mS/cm2 (1.4). 3. Amiloride (10 mumol/l) produced a significant (P less than 0.001) fall in potential difference of 43.0% (5.7) in the trachea, but had no significant effect in the caecum. 4. Subsequently, one of three protocols was used to assess the capacity of either tissue for chloride secretion. Addition of a combination of forskolin (1 mumol/l) and zardaverine (10 mumol/l) produced rises in the potential difference of 873% (509) in the trachea and 399% (202) in the caecum. Both A23187 (10 mumol/l) and phorbol dibutyrate (10 nmol/l) increased tracheal potential difference by 350% (182) and 147% (47), respectively. Neither had a significant effect in the caecum. 5. Subsequent addition of bumetanide caused a fall in the stimulated potential difference of between 39.8% and 71.7%, depending on secretagogue and tissue type.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sevoflurane versus Halothane: Postoperative Maladaptive Behavioral Changes: A Randomized, Controlled Trial

Background: The authors conducted a double-blind, randomized, controlled trial to determine whether the use of sevoflurane in children undergoing anesthesia and surgery results in a higher incidence of postoperative maladaptive behavioral changes as compared with halothane.

Methods: Children and their parents (n = 102) were randomly assigned to either a halothane group (n = 50) or a sevoflurane group (n = 52). The intraoperative anesthetic protocol was strictly controlled, and the postoperative analgesic consumption and pain levels were recorded. The effect of the group assignment on emergence status and maladaptive postoperative behavioral changes was assessed both by validated psychological measures and physiologic instruments (actigraphy) on postoperative days 1-7. Anxiety of the parent and child was also assessed, as was the child's postoperative recovery (Recovery Inventory).

Results: There were no group differences in preoperative state anxiety, postoperative analgesic requirements, postoperative pain, or the incidence of emergence delirium (P = not significant). Two-way repeated-measures analysis of variance showed no group differences in the incidence of postoperative maladaptive behaviors (F4,72 = 0.60, P = 0.701) or actigraphic variables such as percent sleep, number of night awakenings, and night awakenings that lasted for more than 5 min (P = not significant).     

Partial resolution of acute interstitial pneumonia in native lung after single lung transplantation.

The case of a 49 year old man presenting with rapidly progressive interstitial lung disease is described. Radiological findings and the lung biopsy specimen were compatible with an acute interstitial pneumonia, as was the relentless clinical course culminating in hypoxic respiratory failure. After right single lung transplantation there was considerable improvement in lung function and radiographic clearing of disease in the native left lung.     

Early developmental 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure decreases chick embryo heart chronotropic response to isoproterenol but not to agents affecting signals downstream of the beta-adrenergic receptor.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes cardiovascular toxicity in laboratory animals, including alteration in several processes in which beta-adrenergic receptor (beta-AR) signaling plays important roles. Thus, our laboratory investigated the effects of TCDD on beta-AR expression and signal transduction. Fertile chicken eggs were injected with vehicle (corn oil), 0.24 or 0.3 pmol TCDD/g egg on incubation day 0 (D0) or D5. On D10, heart function was assessed by ECG in ovo. Exposure to TCDD increased the incidence of arrhythmias and decreased the positive chronotropic responsiveness of the heart to isoproterenol. The reduced beta-AR responsiveness was, in part, independent of any overt morphological changes in the heart as chick embryos exposed to TCDD on D5 displayed an intermediate responsiveness to beta-AR agonist in the absence of the dilated cardiomyopathy observed in chick embryos exposed to TCDD on D0. TCDD did not decrease the chronotropic response of the heart to agents that stimulate signals downstream of the beta-AR. In fact, TCDD-exposed embryos were more sensitive than controls to forskolin, increasing heart rates (HR) 21.8 +/- 3.5 beats per min (bpm) above baseline versus control values at 6.3 +/- 2.7 bpm above baseline. TCDD exposure also augmented the negative chronotropic response of the heart to verapamil, decreasing HR -23.2 +/- 7.4 bpm relative to baseline versus control embryos at -12.7 +/- 5.9 bpm below baseline. Finally, the mean cardiac beta1-AR mRNA expression in D10 embryos was not significantly altered by exposure to TCDD on D0. These findings establish that a functional end point of the developing chick heart is sensitive to TCDD exposure and that the TCDD-induced reduction in beta-AR responsiveness may result from alterations in signal transduction upstream of adenylyl cyclase.     

An efficient SNP system for mouse genome scanning and elucidating strain relationships

A set of 1638 informative SNP markers easily assayed by the Amplifluor genotyping system were tested in 102 mouse strains, including the majority of the common and wild-derived inbred strains available from The Jackson Laboratory. Selected from publicly available databases, the markers are on average ~1.5 Mb apart and, whenever possible, represent the rare allele in at least two strains. Amplifluor assays were developed for each marker and performed on two independent DNA samples from each strain. The mean number of polymorphisms between strains was 608±136 SD. Several tests indicate that the markers provide an effective system for performing genome scans and quantitative trait loci analyses in all but the most closely related strains. Additionally, the markers revealed several subtle differences between closely related mouse strains, including the groups of several 129, BALB, C3H, C57, and DBA strains, and a group of wild-derived inbred strains representing several Mus musculus subspecies. Applying a neighbor-joining method to the data, we constructed a mouse strain family tree, which in most cases confirmed existing genealogies.