In what sense is implicit memory "episodic"? The effect of reinstating environmental context

We consider three aspects of the term episodic. Previous literature shows implicit memory does not make conscious autobiographical reference but does code an item's intrinsic context (e.g., perceptual detail). Here, we consider extrinsic context--namely, that not directly processed as part of item identification and not overtly relevant to the task. Study-test mismatch in environmental context (outdoors vs. indoors) reduced memory in an explicit stem-cued recall task but had no effect on repetition priming in an implicit stem completion task. This was true even for very low frequency words. We support the view that implicit memory reflects traces within perceptual (or semantic) knowledge-based systems that are instance specific but do not code the full spatiotemporal context information necessary to support conscious recollection. We also interpret our results as consistent with differences in environmental context specificity between free recall and recognition.

Are metal mining effluent regulations adequate: identification of a novel bleached fish syndrome in association with iron-ore mining effluents in Labrador, Newfoundland

Water quality guidelines for industrial effluents are in place in many countries but they have generally evolved within a limited ecotoxicological framework. Effluents from iron-ore mines have traditionally been viewed by regulatory bodies as posing little or no risk to the aquatic environment. However, it was recently reported that lake trout taken from a large iron-ore contaminated Lake in Labrador (Wabush Lake) had elevated levels of DNA oxidative damage and were markedly depleted in levels of vitamin A (Payne et al., 1998) in comparison with fish from a Lake (Shabogamo Lake) receiving lesser levels of effluents. Through further observations, it has now been established that the lake trout in Wabush Lake are commonly affected with a marked skin bleaching syndrome in comparison with fish in Shabogamo Lake and a nearby Lake (Ashuanipi) which does not receive effluents. To the authors' knowledge such a syndrome which is characterized by marked reduction in skin pigmentation and overall increase in skin whitening has not been reported before in any fish population in association with contamination. Preliminary information for liver histopathological and blood cell differences have also been obtained in fish in Wabush Lake in comparison with Ashuanipi Lake. It has also been observed through studies on phosphatidyl liposomes that iron-ore leachate contains redox-active material (iron but possibly other transition metals) that has considerable potential for causing oxidative damage to cellular constituents. Using the weight of evidence approach it is indicated that iron-ore effluents may pose more of a risk to the aquatic environment than traditionally considered by regulatory agencies.

Regulation of peroxisome proliferator activated receptor alpha-mediated pathways in alcohol fed cytochrome P450 2E1 deficient mice

Fatty acids are substrates and inducers for cytochrome P450 2E1 (CYP2E1) and peroxisome proliferator activated receptor alpha (PPARalpha). Previously, we have shown that the ethanol-induced CYP2E1 expression in rat is accompanied by the inhibition of the expression of the PPARalpha gene and the reduction in polyunsaturated fatty acid content. To further analyze the effect of CYP2E1 and ethanol in PPARalpha-mediated fatty acid homeostasis, the expression of PPARalpha and retinoid x receptor alpha (RXRalpha) and their target genes was examined in ethanol fed CYP2E1 deficient mice. Our data demonstrated that the expression of PPARalpha and RXRalpha genes was activated in the livers of CYP2E1-null mice suggesting a compensatory effect for the absence of CYP2El. In addition, the expression of PPARalpha target genes, which included the liver fatty acid-binding protein, malic enzyme, and CYP4A1 genes, was induced indicating the activation of PPARalpha-mediated pathways in CYP2E1 deficient mice. Ethanol inhibited the expression of some of the PPARalpha target genes in wild-type mouse livers, and the inhibitory effect of ethanol was particularly prominent in the CYP2E1-null mice. Morphologically, centrilobular fat accumulation was detected in the ethanol fed CYP2E1-null mouse livers suggesting that inhibition of PPARalpha-mediated pathways might be responsible for the ethanol-induced fatty liver in CYP2El-null mice. In addition, the expression of CYP2E1 was not changed in the PPARalpha-null mice. These data suggest that CYP2E1 and ethanol can regulate PPARalpha-mediated fatty acid homeostasis. CYP2E1-induced lipid peroxidation might play a major role in lipid metabolism, PPARalpha only becomes important when the CYP2E1 level is low and polyunsaturated fatty acids increase.

Hybrid external fixation of tibial pilon fractures

Although external fixation reduces drastically the number of iatrogenic complications compared with acute open reduction and plate fixation, the prognosis for functional recovery after a pilon fracture remains guarded. Many authors have applied validated patient outcome measures to patients who have had pilon fractures. These studies confirmed that there are significant decreases in general health perceptions, physical and emotional role function, pain, and energy levels in patients who have suffered pilon fractures, regardless of the treatment modality. The high-energy tibial pilon fracture with soft tissue compromise remains a treatment dilemma. Hybrid external fixation with limited open reduction has proved to be a safe, reproducible, and effective treatment modality for this complex fracture.

Right ventricular perforation with cardiac tamponade associated with use of a temporary pacing wire and abciximab during complex coronary angioplasty

We describe our recent experience of right ventricular perforation leading to cardiac tamponade associated with a complex coronary angioplasty in which abciximab and a temporary pacing wire were used. This is to highlight the possibility that the combined use of temporary pacing wires and the IIb/IIIa receptor antagonists may be associated with an increased risk of this serious complication. Cathet. Cardiovasc. Intervent. 48:388-389, 1999.

Molecular epizootiology of genotoxic events in marine fish: linking contaminant exposure, DNA damage, and tissue-level alterations

Molecular epizootiological studies are increasingly being used to investigate environmental effects of genotoxic contaminants. The assessment of damage to DNA and linking the damage to subsequent molecular, cellular, or tissue-level alterations is a central component of such studies. Our research has focused on the refinement of the 32P-postlabeling assay for measuring covalent DNA-xenobiotic adducts arising from exposure to polycyclic aromatic compounds, using DNA adducts as molecular dosimeters of genotoxic contaminant exposure in biomonitoring studies, and investigating the relationship of DNA adduct formation to toxicopathic liver disease, including neoplastic lesions. A combination of field and laboratory studies using the 32P-postlabeling assay has shown that DNA adducts in marine fish are effective molecular dosimeters of genotoxic contaminant exposure. Investigations of the relationship of DNA adduct formation to neoplastic liver disease have shown that elevated levels of DNA adducts in certain fish species from contaminated coastal sites are associated with increased prevalences of toxicopathic hepatic lesions, including neoplasms, and that the ability to assess DNA damage has helped to explain, in part, species differences in lesion prevalence. Moreover, in a study of a site in Puget Sound contaminated with polycyclic aromatic compounds, we have shown, for the first time, that elevated levels of hepatic DNA adducts are a significant risk factor for certain degenerative and preneoplastic lesions occurring early in the histogenesis of hepatic neoplasms in feral English sole (Pleuronectes vetulus). These latter findings coupled with our current studies of mutational events in the K-ras proto-oncogene should provide further mechanistic substantiation that mutagenic events resulting from exposure to complex mixtures of genotoxic polycyclic aromatic compounds are involved in the etiology of hepatic neoplasia in English sole.

Developing the skills required for evidence-based practice

The current health care environment requires practitioners with the skills to find and apply the best currently available evidence for effective health care, to contribute to the development of evidence-based practice protocols, and to evaluate the impact of utilizing validated research findings in practice. Current approaches to teaching research are based mainly on gaining skills by participation in the research process. Emphasis on the requirement for rigour in the process of creating new knowledge is assumed to lead to skill in the process of using research information created by others. This article reflects upon the requirements for evidence-based practice, and the degree to which current approaches to teaching research prepare practitioners who are able to find, evaluate and best use currently available research information. The potential for using the principles of systematic review as a teaching and learning strategy for research is explored, and some of the possible strengths and weakness of this approach are highlighted.

British studies which measure patient outcome, 1990-1994

In order to assess the context and use of patient-outcome measurement in nursing. British studies reported in Nursing Research Abstracts, published by the Department of Health in the 5-year period between January 1990 and December 1994 which measured patient outcome were retrieved, and analysed in relation to the nursing specialty, intervention and outcome variables, and method of measurement used. A total of 228 studies which measured patient outcome were identified, which included 516 occurrences of patient-outcome measurement. Fifty per cent of studies measured a single outcome variable. Physical health status and psychosocial functioning outcomes accounted for over half of the total number of variables used, with generic well-being measures least frequently used; 38% of the studies utilized existing outcome measurement tools, or researcher-constructed tools which had been tested for reliability and validity; 62% utilized tools constructed specifically for the study or physiological/biochemical measures. There was variation in the frequency of use of multiple outcome variables and existing measurement tools between different clinical specialties. The 228 studies included 119 different outcome-measurement tools/instruments, with only 20 measurement tools used more than once. The analysis identified a large range of patient-outcome variables and measurement tools included in nursing studies, but little coherence in definition and method of measurement between studies.

Drug and alcohol use of school-age children in a rural community

Drug abuse affects the physical and psychological well-being of the user as well as creating heavy societal costs--which are amplified if the user is a child. This study examined the relationship between drug and alcohol use and self-esteem, school climate, peer effects, and family climate among a small sample of fourth graders in a rural community.

Pain management knowledge, attitudes and clinical practice: the impact of nurses' characteristics and education

This study examined the knowledge, attitudes, and clinical practice of registered nurses (N = 120) regarding pain management. Data were collected from nine varied clinical units in a large, university-affiliated, teaching hospital in an urban area of the Northeast. Demographic information was also collected to explore the relationship between nurses' characteristics, including previous pain education, clinical experience, area of clinical practice, and other variables, and knowledge, attitudes, and clinical practice. Three instruments were used in the study: (a) the Pain Management: Nurses' Knowledge and Attitude Survey; (b) a 12-item demographic questionnaire; and (c) a Pain Audit Tool (PAT) to gather data regarding pain assessment, documentation, and treatment practices from charts. Mean scores from the nursing knowledge and attitudes survey on pain revealed knowledge deficits and inconsistent responses in many areas related to pain management (mean, 62%; range, 41%-90%). The top two nurse-ranked barriers to pain management were related to patient reluctance to report pain and to take opioids for pain relief. Demographic data revealed that education about pain was most inadequate in the following areas: nonpharmacological interventions to relieve pain, the difference between acute and chronic pain, and the anatomy and physiology of pain. Chart audits with the Pain Audit Tool revealed that 76% of the charts (N = 82) lacked documentation of the use of a patient self-rating tool by nurses to assess pain, despite a high reported use (76%) of such a self-rating tool. Adjunct medications were ordered with some consistency, but appeared to be underutilized. This was especially true of nonsteroidal anti-inflammatory agents (mean use, 1%). Ninety percent of the charts had no documentation of the use of nonpharmacological interventions to relieve pain. Although this clinical setting has policies and resources in place regarding the management of pain, it would appear that they are not optimal. Practical recommendations are presented for increasing nurses' knowledge about pain management; improving the quality and the consistency of the assessment, documentation and treatment of pain; and disseminating pain management information.

Electronic signature thrives in different environments

Implementing electronic signature has been a positive experience for both our organizations. The benefits we sought were there, and unforeseen benefits surfaced. Five activities that facilitated the success of electronic signature at our two facilities were (1) flowcharting the electronic signature process prior to purchase and installation; (2) becoming familiar with legal requirements for electronic signature, and assuring that products under consideration meet these requirements; (3) gaining the support of medical staff leadership; (4) using a written agreement of password confidentiality and document responsibility with physicians; and (5) thoroughly training medical records staff, then establishing a positive one-on-one training procedure for physicians with a high degree of staff attention.

The urgent care crunch. Medicaid managed care tackles emergency use--with mixed results

With so many state Medicaid programs all rushing to implement managed care programs, it's clear Medicaid managed care is here to stay. The issues involved in making these programs work, it turns out, are more practical than theoretical. And some states are doing better than others.

32P-postlabeling analysis of DNA adduct formation and persistence in English sole (Pleuronectes vetulus) exposed to benzo[a]pyrene and 7H-dibenzo[c,g]carbazole

The formation and persistence of benzo[a]pyrene (BaP)- and 7H-dibenzo[c,g]-carbazole (DBC)-DNA adducts in liver of English sole (Pleuronectes vetulus) were investigated. BaP is a putative hepatocarcinogen in English sole based on its ability to induce formation of preneoplastic foci, while DBC is a hepatocarcinogen in mammals but whose carcinogenicity in fish is not known. English sole liver was sampled from 2 h through 84 days after a single intermuscular injection of a BaP and DBC mixture (100 mumol of each/kg body wt.), and DNA adduct levels were measured by the nuclease P1 version of the 32P-postlabeling assay. The major BaP adducts detected were from binding of BaP-7,8-diol-9,10-epoxide to DNA, whereas multiple uncharacterized DBC-DNA adducts were detected. Total adduct levels for both BaP and DBC reached a maximum at 2 days post exposure. The levels of DBC-DNA adducts were greater than the levels of BaP adducts at all time points and increased more rapidly than did the levels of BaP-DNA adducts. The DBC to BaP adduct ratio was 33 +/- 8.8 at 2 h and declined to 4.2 +/- 0.48 by 12 h post exposure. From 2 to 28 days, the levels of both BaP and DBC adducts declined with apparent half-lives of 11 and 13 days, respectively. There was no apparent decline from 28 to 84 days in the levels of the remaining BaP or DBC adducts; these persistent adducts represented 32 and 36% of maximum levels, respectively. These results provide the first data on the kinetics of adduct formation and removal of a carcinogenic nitrogen-containing polycyclic aromatic compound in fish. The results showing greater binding and similar persistence of DBC-DNA adducts compared to BaP-DNA adducts suggest that DBC may be hepatotoxic and potentially carcinogenic in English sole. In a separate experiment, the effect of multiple doses of BaP (30 mumol/kg body wt.) on the levels of hepatic BaP-DNA adducts showed that adduct levels increased linearly (r = 0.815, P = 0.0007) with 5 successive doses administered at 2 day-intervals and sampled 2 days after the last dose. The persistence of both BaP-DNA and DBC-DNA adducts in liver, together with the increase in BaP-DNA adducts in English sole exposed to successive doses of BaP, suggest that hepatic xenobiotic-DNA adducts in English sole are molecular dosimeters of relatively longterm environmental exposure to genotoxic polycyclic aromatic compounds.

Storage phosphor imaging technique for detection and quantitation of DNA adducts measured by the 32P-postlabeling assay

The 32P-postlabeling method has found wide application as a sensitive technique for detecting the presence of a broad range of bulky aromatic compounds covalently bound to DNA. In this method, the modified DNA is enzymatically degraded to 3'-mononucleotides and labeled with [32P]-phosphate at the 5'-position using [gamma-32P]ATP and T4 polynucleotide kinase. The 32P-labeled DNA digest is then chromatographed in two dimensions on polyethyleneimine - cellulose thin-layer plates. Screen-enhanced autoradiography is used to locate the presence of the radiolabeled adducts on the chromatogram, and the radioactive areas are generally excised and quantitated by liquid scintillation spectrometry. However, on a chromatogram with multiple adducts, it can be difficult to quantitative partially resolved adducts and evaluated background radioactivity levels. We have evaluated the use of storage phosphor imaging techniques to quantitate and map the radioactivity on chromatograms generated by the 32P-postlabeling method. The results showed that storage phosphor imaging was approximately 10 times more sensitive than screen-enhanced autoradiography at -80 degrees C for the detection of 32P, exhibits a greater linear range of response, has a resolution that compares favorably to film and has a lower background than does liquid scintillation spectrometry. Further, the generation of a digitized record of the distribution and intensity of radioactivity allows for computer-assisted assessment of adduct profiles and can facilitate quantitation of individual adducts and radioactive zones comprised of multiple overlapping adducts in complex chromatograms. Additionally, the permanent record created by the imaging technology permits facile retrospective analysis of samples, whereas with autoradiography and liquid scintillation spectrometry reanalysis of a replicate sample is required.

Elevated maternal serum alpha-fetoprotein values. How low is high?

Most maternal serum alpha-fetoprotein (MSAFP) screening programs are set up with the goal of prenatal detection of fetal neural tube defects. It is also commonly accepted that MSAFP testing yields many false-positive results. Screening programs commonly utilize schemata that identify abnormal levels of MSAFP as greater than 2.5 multiples of the median (MOM) and also recommend two abnormal values before initiating ultrasound evaluation. Our pilot program evaluating obstetric outcomes found that 21 of the 29 women with elevated MSAFP values (greater than 2.0 MOM) eventually developed significant pregnancy management changes or complications of pregnancy. Thus, we believe that the use of MSAFP screening solely for the purpose of detecting fetal neural tube defects is inconsequential relative to its usefulness in detecting other pregnancy abnormalities. We also believe that ultrasound evaluation should be accomplished after the first abnormal value and that the cutoff of 2.5 MOM should be lowered to at least 2.0.