Influence of ejection fraction on hospital mortality, morbidity, and costs for CABG patients

BACKGROUND: Preoperative ejection fraction (EF) has been shown to adversely affect postoperative hospital mortality and morbidity for patients undergoing isolated coronary artery bypass grafting. METHODS: To investigate influence of EF on isolated coronary artery bypass grafting outcomes (overall hospital mortality, hospital cardiac mortality, hospital morbidity, and hospital costs), data were reviewed from 1,354 consecutive patients who underwent isolated coronary artery bypass grafting between January 1, 1990, and April 30, 1992, at a single nonprofit hospital. Overall hospital mortality was 4.06% (cardiac, 2.36%). Hospital morbidity was 14.25% (including mortality). Hospital costs (not charges) averaged $16,673 per patient. To explore the impact of preoperative EF, EF was stratified into regular intervals. Each interval was then compared with regard to hospital mortality, morbidity, and average costs. A new statistical tool, discharge analysis, was developed to analyze the cost data. This was necessary because previous efforts at cost analysis have used tools inappropriate for real world cost data. RESULTS: The statistical analysis showed that patients with EF of 0.40 or greater had the best outcomes (lowest mortality, morbidity, and cost). Once the EF is 0.40 or greater the EF does not carry further predictive value. At EF less than 0.40, patients with EF less than 0.30 have a poorer outcome than patients with EF of 0.30 to 0.39. CONCLUSIONS: (1) Ejection fraction is a valid predictor of mortality, morbidity and resource utilization based on statistical analysis. (2) Patients can be broadly grouped as having EF greater than 0.40, less than 0.30, or from 0.30 to 0.39 with regard to clinical and cost outcomes. (3) Postoperative length of stay is not predicted by risk-adjusted EF. (4) A new tool, discharge analysis, is presented to facilitate cost analysis.     

A seminar/case-based approach to teaching removable partial dentures to predoctoral students

OBJECTIVE: To explore potential long term consequences of second trimester amniocentesis. DESIGN: Children exposed to second trimester amniocentesis have been followed prospectively from birth to school age and compared with children whose mothers declined the test. SETTING: The Hospital for Sick Children, Toronto. SAMPLE: Eighty-six children exposed to amniocentesis and 44 children whose mothers declined the test. INTERVENTIONS: Second trimester amniocentesis for the late maternal age indication. MAIN OUTCOME MEASURES: Standardised tests of intelligence, academic achievement, speech articulation, visual-perceptual-motor ability and fine motor coordination were administered. Parents reported on child behaviour using standardised measures of behaviour problems, social competence, hyperactivity and temperament. Physical growth was also measured, and parents reported on child health. RESULTS: Group differences were not observed. CONCLUSIONS: Second trimester amniocentesis does not appear to compromise child development, behaviour, growth or health.     

Regulation of thrombospondin in the regenerating mouse facial motor nucleus

Thrombospondin (TSP) is a multifunctional extracellular matrix protein that plays a role in neuronal migration and axonal outgrowth in the developing central nervous system. In the current study we have examined the localization and regulation of TSP immunoreactivity (TSP-IR) during neuronal regeneration in the axotomized facial motor nucleus using Western blotting and light and electron microscopy. Transection of the facial nerve led to a gradual increase in TSP-IR in the regenerating motoneurons, peaking 4-7 days after injury (DAI). In addition to regenerating neurons, axotomy also caused a rapid upregulation of TSP-IR on activated microglia throughout the facial nucleus, with a maximum of 2-3 DAI, and a second increase at 14-21 DAI on microglial aggregates surrounding degenerating motoneurons and in neuronophagic microglia. In summary, injury leads to the induction of thrombospondin on axotomized neurons and activated microglia, peaking at the times of maximal posttraumatic microglial proliferation and during neuronal phagocytosis. Since thrombospondin is a multimodal extracellular matrix protein with a variety of cell attachment sites, thrombospondin might serve to link microglia and injured neurons, followed by microglial proliferation and removal of the neuronal debris.     

Prion diseases: transmission from mad cows?

Prion diseases in humans show considerable clinical and pathological heterogeneity. The identification of a new variant of Creutzfeldt-Jakob disease, and its interpretation as evidence of transmission of mad cow disease to man, rely critically on our understanding of the epidemiology of prion diseases.     

Tolerance to rat liver allografts: IV. Acceptance depends on the quantity of donor tissue and on donor leukocytes

Liver allografts in some rat strains are often spontaneously accepted across a complete major histocompatibility barrier without the requirement for immunosuppression while other nonliver allografts are rejected. In previous studies, we have shown that spontaneous acceptance is dependent on liver passenger leukocytes. Depletion of passenger leukocytes by donor irradiation allows rejection, with DA recipients of irradiated PVG livers having a median survival time (MST) of 16 days. Here we show that, in this model, spontaneous acceptance is reconstituted by intravenous injection of donor leukocytes. Intravenous injection of 3-5x10(7) PVG liver leukocytes significantly prolonged DA survival time (MST=96 days, P=0.026), as did 5x10(7) spleen leukocytes (MST>100 days, P=0.002). Deletion of T cells from the reconstituting inoculum reduced survival time (MST=78 days, P=0.039), whereas deletion of B cells or monocytes/macrophages had no effect on survival time. In contrast, PVG hearts are regularly rejected by DA recipients, and PVG liver or spleen leukocytes, even at doses of greater than 3x10(8) cells/recipient, were unable to induce heart acceptance. To investigate the possibility that acceptance of the irradiated liver but not the heart might be due to the large mass of the liver, two kidneys and two hearts of PVG origin were transplanted to each DA recipient together with 1.5x10(8) PVG leukocytes. These organs survived for greater than 200 days, thereby showing that a large mass of donor tissue, in association with donor leukocytes, leads to acceptance of organs that are rejected if transplanted singly. It appears likely that spontaneous liver transplant tolerance is a high-dose or activation-associated immune phenomenon.     

Purification of a mammalian homologue of Escherichia coli endonuclease III: identification of a bovine pyrimidine hydrate-thymine glycol DNAse/AP lyase by irreversible cross linking to a thymine glycol-containing oligoxynucleotide

We purified a homologue of the Escherichia coli DNA repair enzyme endo nuclease III 5000-fold from calf thymus which, like endonuclease III, demonstrates DNA-glycosylase activity against pyrimidine hydrates and thymine glycol and AP lyase activity (DNA strand cleavage at AP sites via beta-elimination). The functional similarity between the enzymes suggested a strategy for definitive identification of the bovine protein based on the nature of its enzyme-substrate (ES) intermediate. Prokaryotic DNA glycosylase/AP lyases function through N-acylimine (Schiff's base) ES intermediates which, upon chemical reduction to stable secondary amines, irreversibly cross link the enzyme to oligodeoxynucleotides containing substrate modified bases. We incubated endonuclease III with a 32P- labeled thymine glycol-containing oligodeoxynucleotide in the presence of NaCNBH3. This resulted in an increase in the apparent molecular weight of the enzyme by SDS-PAGE. Phosphorimaging confirmed irreversible cross linking between enzyme and DNA. Identical treatment of the most purified bovine enzyme fraction resulted in irreversible cross linking of the oligodeoxynucleotide to a predominant 31 kDa species. Amino acid analysis of the 31 kDa species revealed homology to the predicted amino acid sequence of a Caenorhabditis elegans 27.8 kDa protein which, in turn, has homology to endonuclease III. The translated amino acid sequences of two partial 3' cDNAs, from Homo sapiens and Rattus sp., also demonstrate homology to the C. elegans and bovine sequences suggesting a homologous family of endonuclease III-like DNA repair enzymes is present throughout phylogeny.