Counting individual 41Ca atoms with a magneto-optical trap

Atom trap trace analysis, a novel method based upon laser trapping and cooling, is used to count individual atoms of 41Ca present in biomedical samples with isotopic abundance levels between 10(-8) and 10(-10). The method is calibrated against resonance ionization mass spectrometry, demonstrating good agreement between the two methods. The present system has a counting efficiency of 2x10(-7). Within 1 h of observation time, its 3-sigma detection limit on the isotopic abundance of 41Ca reaches 4.5x10(-10).

Clinical decision-making in hypertension using an automated (BpTRU) measurement device

Mercury sphygmomanometers are being removed from clinical practice in the United States due to environmental concerns about mercury toxicity. Accurate blood pressure measurement is central to high-quality hypertension management. In this study of 106 patients, the BpTRU(TM) device was compared to nurse blood pressure measurements that complied with all the JNC VII/American Heart Association guidelines in evaluation of a random casual blood pressure. The intermethod difference in systolic blood pressure was +1.8+/-5.1 mmHg, and for diastolic blood pressure it was 4.8+/-5.1 mmHg (both P<0.001). For the primary study end point of clinical decision-making, there was 92% (97/106) agreement between the hypertension nurse specialist and the BpTRU (kappa 0.8280, 95% confidence interval, 0.721-0.9350). The oscillometric blood pressure measurement with the BpTRU is recommended as a replacement for poorly performed auscultatory blood pressure measurement in clinical practice.

Relationships between arteriosclerosis, cerebral amyloid angiopathy and myelin loss from cerebral cortical white matter in Alzheimer's disease

Pathological relationships between damage to the deep white matter of the cerebral cortex [as evidenced by myelin loss (ML)], cerebral amyloid angiopathy (CAA) and arteriosclerosis (ART) were investigated in the brains of 137 patients with autopsy-confirmed Alzheimer's disease (AD), in order to better understand the causes of white matter damage in AD, and the contribution of this to the pathogenesis of the disorder. All 137 patients had some degree of CAA in one or more brain regions although the occipital cortex was severely affected by CAA more frequently, and consequently mean CAA severity score was significantly greater, than other cortical regions. Eighty-seven patients (63.5%) were affected by ML, with more patients showing ML from occipital cortex than from other cortical regions leading to a significantly higher mean ML severity score in this region. One hundred and twenty-six patients (92%) were affected by ART, although the occipital cortex was not more frequently affected by ART than other cortical areas, the mean ART severity score in occipital cortex was nonetheless significantly greater than that of frontal and temporal cortex. Eighty-seven patients showed both CAA and ML, although there was only a weak correlation between degree of CAA and extent of ML (P = 0.035). Forty-seven patients showed ML and significant ART, 16 patients showed significant ART but no ML, 40 patients showed ML in the absence of significant ART and 34 patients showed neither significant ART nor ML. Overall, and for each of the four brain regions, the extent of ML correlated significantly (P < 0.001) with degree of ART. However, when only those 47 patients with ML and significant ART were considered, much stronger correlations between the extent of ML and the degree of ART were achieved both overall and within each of the four brain regions. The overall ART severity score (and overall scores for each pathological marker of ART) significantly correlated with that of CAA (P < 0.001). Pathological processes leading to white matter damage, in terms of ML at least, in AD are thus likely to be heterogeneous. Many patients suffer ML in association with ART, but in others ML cannot be explained by presence of ART or CAA. In such patients, autoregulatory changes in blood vessels might be responsible for ML. The association between the extent of CAA and ART suggests shared risk factors for each pathological change.

Negative association between amyloid plaques and cerebral amyloid angiopathy in Alzheimer's disease

Cerebral amyloid angiopathy (CAA) is an important, though still relatively neglected, aspect of the pathology of Alzheimer's disease (AD), and both the source of amyloid beta protein (Abeta) in CAA, and its relationship to senile plaque (SP) Abeta, remain unclear. We have investigated the relationship between Abeta deposition in SP and CAA in four regions of brain from 69 patients with AD in order to gain insight into the pathogenetic mechanism(s) underlying these pathologies. CAA was present to some degree in all 69 patients, with the occipital cortex being affected more often and more severely than frontal, temporal and parietal cortices. By definition, SPs were present in all brain areas in all 69 patients, with greater uniformity of distribution than CAA, though the occipital cortex was less severely affected than the other brain regions. There was no significant (positive) correlation between CAA rating and that of SP for any one cortical region, but on combining data from all four regions there was a significant inverse correlation (P=0.037) between CAA and SP ratings. Such data suggest that the cellular sources and mechanisms leading to Abeta deposition as SP or CAA are likely to differ and may proceed independently of each other.

A polymorphism in the angiotensin 1-converting enzyme gene is associated with damage to cerebral cortical white matter in Alzheimer's disease

The impact of the insertion (I)/deletion (D) (I/D) polymorphism in the angiotensin 1-converting enzyme (ACE) gene on the extent of white matter myelin loss (ML) was investigated in four regions of the cerebral cortex in an autopsy-confirmed series of 93 patients with Alzheimer's disease (AD). The possible influence of APO E epsilon4 allele acting in concert with ACE D allele was assessed. The extent of ML did not differ between D/D, I/D and I/I genotype groups when data from all four brain regions were combined. However, separate analysis showed that the frontal and temporal cortex tended to be affected more severely by ML in patients with D/D genotype compared to those with I/D and I/I genotypes. Stratification according to APO E epsilon4 allele revealed a greater overall ML in patients bearing at least one copy of ACE D allele and one APO E epsilon4 allele, especially in individuals homozygous for both. The APO E epsilon4 allele may therefore act synergistically in patients with AD (and other subjects) bearing ACE D/D genotype to increase the risk of ML, perhaps through transient ischaemic episodes consequent upon poor cardiac output associated with coronary atherosclerosis in patients with the APO E epsilon4 allele.

Genetic transformation of Dichanthium annulatum (Forssk)--an apomictic tropical forage grass

Eleven Dichanthium annulatum (Forssk) plants were regenerated from embryogenic callus co-transformed with two plasmids encoding either the hygromycin phosphotransferase gene (hph) or the beta-glucuronidase (GUS) gene (uidA). Analysis of these putative transformants showed that three plants were transformed with the hph gene, showed the presence of the hph transcript and expressed hygromycin resistance after transfer to soil. Two of these also contained the uidA gene but did not express GUS and were shown to be the same transformation event. All three of the transformants set seed. Hygromycin resistance varied from 68-100% in the progeny of the three transformants. Transgene transmission appeared to have been mainly through apomixis.

Accuracy of routine data on MMR vaccination coverage and validity of parental recall of vaccination

A study was conducted to re-validate the measles, mumps and rubella (MMR) coverage and measles susceptibility in children resident in Bolton and born between 1991 and 1995; also to examine the accuracy of parental recall of children's MMR vaccination status. Using general practitioner/practice held records, a validation survey was conducted on a random sample of 171 reportedly unvaccinated children. A questionnaire survey was used to assess parental recall. 'Records' to 'recall' agreement was examined. One- and two-dose population coverage according to routine data was 94.6% and 75.2% respectively, with measles susceptibility of 8.1%. Based on the 'records' survey, one- and two-dose population coverage estimates were 97.4% (+2.8%) and 78.9% (+3.7%), with a revised susceptibility estimate of 5.2%, respresenting a 36% reduction in the susceptibility fraction. Routine data may modestly underestimate vaccination coverage and significantly overestimate measles susceptibility. Many parents of MMR unvaccinated children believe that their children have been vaccinated.

Gabapentin and methylphenidate treatment of a preadolescent with attention deficit hyperactivity disorder and bipolar disorder

Gabapentin is an anticonvulsant drug released in the United States in 1993 for use as adjunctive therapy in refractory partial epilepsy. The mechanism of action of gabapentin is unknown, but the drug has very favorable pharmacokinetics and a good safety profile, which allows its use in high-risk patients. Several reports have described the successful use of gabapentin for bipolar disorders in adults, but there are no controlled studies in the use of gabapentin in children and adolescents. We describe a 12-year-old boy with a history of attention deficient hyperactivity disorder (ADHD), reading disorder, mixed receptive and expressive language disorder, encopresis, and bipolar disorder II who was treated with gabapentin 200 mg/day added to methylphenidate 30 mg/day. Within 3 weeks the improvement and stabilization of mood symptoms was remarkable, as noted by mother, teacher, and clinician, and remained so for 6 months of follow-up. Comorbid bipolar disorder and ADHD is a hotly debated topic in the child and adolescent psychiatric literature, with rates of comorbid ADHD and bipolar disorder ranging from 22% to 90%. Controlled studies are needed to evaluate the possible antimanic mood stabilizing and/or antidepressant properties or gabapentin in youths.

Longitudinal electroproduction of charged pions from (1)H, (2)H, and (3)He

Separated longitudinal and transverse cross sections for charged pion electroproduction from (1)H, (2)H, and (3)He were measured at Q(2) = 0.4 (GeV/c)(2) for two values of the invariant mass, W = 1.15 GeV and W = 1.60 GeV, in a search for a mass dependence which would signal the effect of nuclear pions. This is the first such study that includes recoil momenta significantly above the Fermi surface. The longitudinal cross section, if dominated by the pion-pole process, should be sensitive to nuclear pion currents. Comparisons of the longitudinal cross section target ratios to a quasifree calculation reveal a significant suppression in (3)He at W = 1.60 GeV. The W = 1.15 GeV results are consistent with simple estimates of the effect of nuclear pion currents, but are also consistent with pure quasifree production.

Pharmacodynamic evaluation of RWJ-270201, a novel neuraminidase inhibitor, in a lethal murine model of influenza predicts efficacy for once-daily dosing

We examined RWJ-270201 in a lethal model of influenza in BALB/c mice. The aim was to delineate the pharmacodynamically linked variable for the drug. Challenge was performed with influenza virus A/Shongdong/09/93 (H3N2). Treatment was administered by gavage. Five doses (1 to 10 mg/kg of body weight) and three schedules (every 24, 12, and 8 h) were evaluated with 10 mice per group. There were 39 placebo-treated mice. Drug exposure was evaluated for infected mice. Exposures were calculated after population modeling of all the plasma concentration-time data simultaneously using the NPEM3 program. Evaluation of dose and schedule with Kaplan-Meier analysis and Cox proportional hazards modeling demonstrated that schedule offered no explanatory power relative to dose alone. Evaluation of peak concentration, trough concentration, and area under the concentration-time curve (AUC) by the same methods revealed that AUC was the dynamically linked variable. Again, schedule offered no further explanatory power when included in the model with AUC. This indicates that AUC is the linked variable and that the anti-influenza effect of RWJ-270201 is independent of schedule. We conclude that once-daily dosing of RWJ-270201 should be evaluated in clinical trials of influenza therapy.

An Evaluation of Federal Order Reform

The Federal Agricultural Improvement and Reform Act of 1996 required the Secretary of Agriculture to reform federal milk marketing orders. The Secretary carried out this task and issued a final rule on March 31, 1999, that was eventually approved by dairy farmers in a national referendum. However, a temporary restraining order (TRO) was issued on September 28, 1999, that halted the reform process. The TRO was effectively overturned and the reform process restarted when President Bill Clinton signed the Consolidated Appropriations Act of 2000 on November 29, 1999. The final rule as amended consolidates the number of orders, develops a multiple component pricing system that determines new formulas for class prices, and provides a new system for pricing fluid milk based on county-level price differentials. The impact of these changes is to provide more transparency in pricing and improved market signals to farmers. But the new system is also much more vulnerable to changes in dairy commodity prices. The objective of this report is to provide a comprehensive overview of federal order reform and to analyze the impact of recent changes in class price formulas.

Usability evaluation of the progress note construction set

OVERVIEW

The Veterans Administration (VA) Computerized Patient Record System (CPRS) is a nationally deployed software product that integrates provider order entry, progress notes, vitals, consults, discharge summaries, problem lists, medications, labs, radiology, transcribed documents, study reports, and clinical reminders. Users rapidly adopted the graphical user interface for data retrieval, but demanded options to typing for data entry. We programmed "point and click" forms that integrate with CPRS individually, but were soon overwhelmed by requests. Subsequently, we developed the Progress Note Construction Set (PNCS); a tool suite that permits subject matter experts without programming skills to create reusable "point and click" forms. In this study, we evaluate the usability of these user-constructed forms.

METHODS

An untrained, non-VA subject matter expert used the PNCS to create a graphical form for "skin tear" documentation. Ten VA nurses used the skin tear form to document findings for 7 standardized clinical scenarios. Following each scenario the subjects answered usability questions about the form.

RESULTS

The subject matter expert created the skin tear form in 78 minutes. Users found the form to facilitate their data entry (p 0.0265), and to be at least as fast (p 0.0029) and as easy to use as expected (p 0.0166). Average note entry time was 3.4 minutes.

CONCLUSION

The PNCS allowed a non-programmer to quickly create a usable, CPRS-integrated point and click form. Users found the subject matter expert s form fast and easy to use. The tool suite is a more scaleable form creation method because capacity is no longer limited by programmer availability.

Influence of cigarette smoking on crocidolite-induced ferritin release by human alveolar macrophages

Alveolar macrophages (AMs) mobilize iron from the surface of iron-containing minerals such as asbestos and synthesize ferritin for intracellular iron storage or secretion. Although the synthesis of iron-free ferritin (apoferritin) provides antioxidant protection, the secretion of iron-containing ferritin by AMs could increase the availability of catalytic iron in the lungs. Cigarette smoking may promote the secretion of ferritin by AMs after iron acquisition from mineral sources, because smokers' AMs are iron loaded. The first objective of this study was to determine whether ferritin secretion/release by AMs after in vitro exposure to crocidolite asbestos is enhanced by cigarette smoking. The second objective was to assess whether exogenous ferritin-bound iron could enhance the toxicity of crocidolite to lung cells in vitro. AMs recovered from nonsmokers (n = 8) or smokers (n = 8) were exposed to crocidolite or titanium dioxide (TiO2)(1 x 10(6) AMs, 50 to 200 microg/mL) for up to 18 hours. AMs exposed to crocidolite but not TiO2 showed increased cell content of iron and ferritin and increased cell supernatant ferritin concentrations. Increases in iron and ferritin content were similar for AMs recovered from smokers and those recovered from nonsmokers; however, increases in supernatant ferritin were >7-fold greater for smokers' AMs than for nonsmokers' AMs (P < .001). Exposure of A549 cells, a lung cancer-derived cell line, to crocidolite (50 to 200 microg/mL, 18 hours) caused dose-dependent cell death as indicated by lactate dehydrogenase release. The addition of ferritin (> or = 500 mg/mL) but not apoferritin to culture media enhanced crocidolite-induced LDH release (P < .01). These findings suggest that cigarette smoking and crocidolite exposure have synergistic effects that promote ferritin release by AMs, which could catalyze oxidative injury to other alveolar cells.

Acceptability of health status questionnaire screening and vaccination among Kosovar refugees

During 1999, following the war in Kosovo, thousands of Kosovar refugees were received by different countries. The public health reception protocols for these refugees varied widely between and within reception countries. We surveyed a group of Kosovar refugees received in Bolton to assess the acceptability of vaccination and health status questionnaire screening. We also examined the refugees' opinions about the confidentiality of their medical history and their willingness to take part in research. Fifteen out of 29 people responded. Most respondents were happy with the interventions.

The disinfection by-products dichloro-, dibromo-, and bromochloroacetic acid impact intestinal microflora and metabolism in Fischer 344 rats upon exposure in drinking water

Human consumption of chlorinated drinking water has been linked epidemiologically to bladder, kidney, and rectal cancers. The disinfection by-product (DBP) dichloroacetic acid is a hepatocarcinogen in Fischer 344 rats and B6C3F1 mice. The objective of this study is to determine the effect of the DBPs dichloro-, bromochloro-, and dibromoacetic acids (DCA, BCA, DBA) on intestinal microbial populations and their metabolism, with emphasis on enzymes involved in the bioactivation of procarcinogens and promutagens. One-month-old male Fischer 344 rats were provided water ad libitum containing 1 g/l DCA, BCA, or DBA for up to 5 weeks. At 1, 3, and 5 weeks of treatment, beta-glucuronidase (GLR), beta-galactosidase (GAL), beta-glucosidase (GLU), nitroreductase (NR), azoreductase (AR), and dechlorinase (DC) activities were determined in cecal and small and large intestinal homogenates. After 5 weeks of treatment, intestinal populations were enumerated on selective media. Cecal GAL (DCA, BCA, DBA) and GLR (DCA, DBA) activities were reduced after 1 and 3 weeks of treatment and GAL activity was elevated at 5 weeks (BCA). Large intestinal GAL (DCA, BCA) and GLU (DCA, BCA, DBA) activities were elevated after 5 weeks of treatment. Week 5 cecal AR (DCA, BCA, DBA), NR (DCA), and DC (DCA, DBA) activities were reduced. Even though some significant changes in intestinal populations were observed, use of selective media was not sensitive enough to explain fluctuations in enzyme activity. Haloacetic acids in the drinking water alter intestinal metabolism, which could influence bioactivation of promutagens and procarcinogens in the drinking water.

Cardiology services after stress testing: are there sex differences? A population-based study

To test the hypothesis that, in a population-based cohort of persons undergoing stress tests, female sex was negatively associated with the use of cardiology visits in persons with no documented coronary artery disease (CAD) but that this association did not exist when CAD was established. Sex differences in the use of invasive cardiac procedures have been clearly documented, but data on physician encounters, an integral part of care, are lacking. A population-based cohort consisting of all Olmsted County, Minnesota residents who underwent an initial stress test in 1987, 1988, and 1989 in Olmsted County was examined. Medical records were reviewed for baseline characteristics including CAD diagnosis status, test results, and cardiology visits in the year following the stress test. Regression models were constructed to determine whether sex is independently associated with the probability of a visit. In the year after stress testing, there was no difference between the sexes in the use of inpatient (OR for female sex 0.88, 95% CI 0.62-0.97, P = 0.365) and outpatient/consultative (OR for female sex 1.24, 95% CI 0.95-1.61, P = 0.6) cardiology visits. Women were, however, less likely to receive preventive cardiology visits (OR for female sex 0.77, 95% CI 0.62-0.97, P = 0.02). This was largely related to less use of preventive visits among older women with documented coronary artery disease (CAD). In the absence of documented CAD, when the stress test was positive, women were less likely to receive preventive visits. In this geographically defined population within one year after an initial stress test, there was no sex difference in the use of in-patient or out-patient visits but women were less likely to receive preventive cardiology visits in the year after stress testing. Further studies are needed to understand the reasons for and impact of these care patterns.

The nurse's role in promoting breast awareness

BACKGROUND

Breast cancer affects up to one in 12 women in the UK. Breast awareness, which is advocated in place of routine breast examination, involves women becoming more familiar with their bodies.

CONCLUSION

Nurses have a vital role to play in encouraging women to become more breast aware. Their health promotion activities in this area can have an important impact on the uptake of breast screening initiatives.

Ultrasensitive isotope trace analyses with a magneto-optical trap

Laser manipulation of neutral atoms has been used to count individual krypton-85 and krypton-81 atoms present in a natural krypton gas sample with isotopic abundances in the range of 10(-11) and 10(-13), respectively. This method of isotope trace analysis is free of contamination from other isotopes and elements and can be applied to several different isotope tracers for a wide range of applications. The demonstrated detection efficiency is 1 x 10(-7). System improvements could increase the efficiency by many orders of magnitude.

Increased concentrations of iron and isoferritins in the lower respiratory tract of patients with stable cystic fibrosis

Reactive oxygen species may contribute to airway injury in patients with cystic fibrosis (CF) and iron catalyzes oxidant injury by promoting generation of highly reactive hydroxyl radicals. Iron in the lower respiratory tract may be free, ferritin bound (from which iron can be reductively mobilized), or transferrin bound (which generally prevents iron mobilization). Ferritin is composed of subunits that are heavy (H) or light (L), and H-rich ferritins have additional biologic effects including inhibition of lymphocyte proliferation and cell growth. To assess concentrations of iron and iron-binding proteins in the lower respiratory tract of patients with CF, we measured iron (ferrozine), L-ferritin, H-ferritin, and transferrin (enzyme-linked immunosorbent assay [ELISA]) in bronchoalveolar lavage (BAL) fluid recovered from stable patients with CF (n = 8), healthy nonsmokers (NS; n = 8), or heavy cigarette smokers (HS; n = 8). Iron was detected in BAL fluid from patients with CF and HS, but not NS, with higher iron concentrations in patients with CF (42.0 +/- 11.6 microgram/dl) than in HS (9.9 +/- 2.6 microgram/dl, p < 0.05). Ferritin was present in all BAL fluids, with higher total ferritin (L + H) in patients with CF (647 +/- 84 ng/ml) than in HS (181 +/- 25 ng/ml, p < 0.005) or NS (9 +/- 3 ng/ml, p < 0.0005). Ferritin recovered from HS and NS lungs was < 2% H type, whereas ferritin in CF lungs was > 40% H-type ferritin. Transferrin concentrations in BAL fluid were not different in any group. Tumor necrosis factor (TNF)-alpha was present only in BAL samples from patients with CF. To assess whether TNF-alpha contributed to H-ferritin accumulation in CF lungs, we treated lung epithelial cells (A549) with iron alone (FeSO(4), 10-40 microM) or with iron and TNF-alpha (5-20 ng/ml). Iron-treated A549 cells synthesized almost entirely L-ferritin whereas exposure to TNF-alpha with iron caused a dose-dependent increase in accumulation of H-type ferritin. These findings suggest that oxidant injury could be promoted in lungs of patients with cystic fibrosis by iron mobilized from extracellular ferritin and, in addition, that TNF-alpha-promoted accumulation of H-type ferritin may impair local immune function and cell growth.

Effects of TNF-alpha and IL-1beta on iron metabolism by A549 cells and influence on cytotoxicity

Extracellular iron, which is predominantly bound by transferrin, is present in low concentrations within alveolar structures, and concentrations are increased in various pulmonary disorders. Iron accumulation by cells can promote oxidative injury. However, the synthesis of ferritin stimulated by metal exposure for intracellular iron storage is normally protective. The cytokines tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta may alter iron metabolism by alveolar cells. In this study, we assessed the effects of TNF-alpha and IL-1beta on iron metabolism with a cell line with properties of type 2 alveolar epithelial cells (A549) exposed to non-transferrin-bound (NTBI; FeSO(4)) or transferrin-bound (TBI) iron. In addition, we assessed the cytotoxicity of these exposures by measuring the cell accumulation of malondialdehyde (MDA), a product of lipid peroxidation, and cell death (MTT assay and lactate dehydrogenase release). A549 cells treated with NTBI or TBI in concentrations up to 40 microM accumulated iron and synthesized predominantly L-type ferritin without accumulation of MDA or cell death. Treatment of A549 cells with TNF-alpha (20 ng) or IL-1beta (20 ng) decreased cell transferrin-receptor expression and induced synthesis of H-type ferritin. TNF-alpha and IL-1beta decreased the uptake of TBI; however, the uptake of NTBI was increased. Both cytokines enhanced total ferritin synthesis (H plus L types) in response to iron treatments due to enhanced synthesis of H-type ferritin. Coexposure to TNF-alpha and NTBI, but not to TBI, induced MDA accumulation and greater cytotoxicity (MTT and lactate dehydrogenase release) than TNF-alpha alone. These findings indicate that TNF-alpha and IL-1beta modulate iron uptake by A549 cells, with differing effects on TBI and NTBI, as well as on H-ferritin synthesis. Enhanced iron uptake induced by TNF-alpha and NTBI was also associated with increased cytotoxicity to A549 cells.

A longitudinal evaluation of a communication skills programme

Communication is an essential component of palliative care, but patients and their families are often dissatisfied with their interactions with health professionals. Communication difficulties are also a recognized stress factor among health professionals. Education and training, however, are said to improve communication skills. A communication skills training programme for 110 nurses has demonstrated statistically significant improvements in the nurses' skills, but no long-term effect was evaluated. This paper presents the results of the long-term follow-up study. Of the 110 nurses contacted, 20% refused to participate, 45% agreed and 35% did not respond; 33 nurses returned usable data. The mean length of time since completing the original study was 2.5 years. Since completion of the original course there was no statistically significant deterioration or improvement in eight of the nine areas of assessment skills evaluated. In the area of psychological assessment there was a statistically significant improvement, and overall the nurses maintained their skills and improved in this area. The results suggest that over time the nurses became more confident in the emotional areas of care as a result of the training. The two key elements of the training were audio-tape recordings and feedback, which raised self-awareness, and experiential workshops covering ways of handling difficult situations. Whether a similar training effect could be achieved by a short 3-5 day course on communication skills needs addressing, because the integrated training skills course evaluated here is costly. Preliminary evidence suggests that the 3-5-day course may not be as effective, so the increased costs associated with the integrated training skills course may be wisely spent if it improves the quality of nurse-patient interaction as evidence here suggests.

Defective corticogenesis and reduction in Reelin immunoreactivity in cortex and hippocampus of prenatally infected neonatal mice

Recent reports indicate an association between second trimester human influenza viral infection and later development of schizophrenia. Postmortem human brain studies also provide evidence for reduction in Reelin mRNA (an important secretory protein responsible for normal lamination of the brain) in schizophrenic brains. We hypothesized that human influenza infection in day 9 pregnant mice would alter the expression of reelin in day 0 neonatal brains. Prenatally-infected murine brains from postnatal day 0 showed significant reductions in reelin-positive cell counts in layer I of neocortex and other cortical and hippocampal layers when compared to controls. Whereas layer I Cajal-Retzius cells produced significantly less Reelin in infected animals, the same cells showed normal production of calretinin and nNOS when compared to control brains. Moreover, prenatal viral infection caused decreases in neocortical and hippocampal thickness. These results implicate a potential role of prenatal viral infection in causation of neuronal migration abnormalities via reduction in Reelin production in neonatal brains.

Iron uptake promotes hyperoxic injury to alveolar macrophages

Iron uptake by cells may increase the intracellular pool of prooxidant iron prior to storage of iron within ferritin. Because hyperoxia is toxic to alveolar macrophages (AM) via mechanisms involving oxidant stress, we hypothesized that iron uptake by AM might promote hyperoxia-induced injury. To assess this hypothesis, we cultured AM recovered from healthy volunteers under conditions of normoxia or hyperoxia (60% or 95% oxygen) in media of varying iron content, including control media (3 microM iron) and media supplemented with iron (FeCl3; total iron 10, 20, or 40 microM). AM injury was assessed by measuring release of lactate dehydrogenase (LDH), phagocytic activity for yeast, and cytosolic concentrations of calcium ([Ca2+]i) as determined by ratio image analysis of AM loaded with the fluorescent calcium probe indo-1. There was dose-dependent accumulation of iron and ferritin synthesis in AM exposed to iron-supplemented media. Exposure of AM to hyperoxia (60% and 95% oxygen, 18 h) in control media increased LDH release and impaired phagocytic activity for yeast; however, similar hyperoxic exposures in iron-supplemented media significantly increased the cells' LDH release and decreased phagocytosis. Exposure to 95% oxygen increased the [Ca2+]i of AM over 18 h, but similar exposure in iron-supplemented media induced greater increases in [Ca2+]i. As compared with exposure to normoxia, exposure to hyperoxia (60% and 95% oxygen) also decreased iron uptake and, to a greater extent, ferritin synthesis by AM in iron-supplemented media. These data suggest that: (1) iron uptake promotes hyperoxic injury to AM; and (2) hyperoxia impairs the capacity of AM to sequester iron in ferritin.

Intrapulmonary cytokine accumulation following BAL and the role of endotoxin contamination

STUDY OBJECTIVES

BAL induces alveolar inflammation, but its effects on intrapulmonary cytokines and the mechanisms causing inflammation are uncertain. The objectives of this study were: (1) to characterize cytokine response in the lungs to BAL, and (2) to determine whether endotoxin is introduced into the lungs during BAL, which could promote BAL-induced inflammation.

DESIGN AND METHODS

We performed two BAL procedures in healthy volunteers separated by 4 (n=6), 24 (n=5), or 72 h (n=3). The initial BAL was performed in the right middle lobe (RML) and the second BAL was performed in the same location and the lingula. Concentrations of interleukin-8 (IL-8), interleukin-1 (IL-1beta), and transforming growth factor-beta were measured by enzyme-linked immunosorbent assay and tumor necrosis factor-alpha (TNF-alpha) bioactivity was determined. Endotoxin contents of saline (10 and 20 mL) infused through bronchoscopes as well as BAL fluids recovered from six subjects were assessed by limulus amebocyte assay.

RESULTS

At 4 h after the initial lavage, but not at later times, BAL fluid recovered from the RML contained increased concentrations of IL-8 and IL-1beta, and increased TNF-alpha bioactivity. BAL fluid recovered from the lingula contained increased concentrations of TNF-alpha only at 4 h. All BAL samples tested contained detectable endotoxin as did all saline aliquots instilled through bronchoscopes.

CONCLUSIONS

There is intrapulmonary accumulation of the cytokines TNF-alpha, IL-8, and IL-1beta in the lavaged lung within 4 h after BAL; this accumulation resolves by 24 h. Endotoxin contamination of the lungs during bronchoscopy may contribute to BAL-induced lung inflammation.

The effect of three different doses of tranexamic acid on blood loss after cardiac surgery with mild systemic hypothermia (32 degrees C)

OBJECTIVE

Prophylactic administration of tranexamic acid (TA), an antifibrinolytic agent, decreases bleeding after cardiac surgery with systemic hypothermia (25 degrees C to 29 degrees C). Warmer systemic temperatures during cardiopulmonary bypass (CPB) may reduce bleeding and thus alter the requirement for TA. The effect of three different doses of TA on bleeding after cardiac surgery with mild systemic hypothermia (32 degrees C) is evaluated.

DESIGN

Double-blind, prospective, randomized study.

SETTING

University hospital.

PARTICIPANTS

One hundred fifty adult patients undergoing aortocoronary bypass or valvular cardiac surgery.

INTERVENTIONS

Patients received TA, 50 (n = 50), 100 (n = 50), or 150 (n = 50) mg/kg intravenously before CPB with mild systemic hypothermia.

MEASUREMENTS AND MAIN RESULTS

Blood loss through chest drains over 6, 12, and 24 hours after surgery and total hemoglobin loss were measured. Autotransfused blood, transfused banked blood and blood products, and coagulation profiles were measured. Analysis of variance on log-transformed data for blood loss and confidence intervals (CIs) of 0.95 were calculated and transformed to milliliters of blood. No patient was re-explored for bleeding. Blood loss at 6 hours was statistically greater in the 50-mg/kg group compared with the other two groups (p = 0.03; p = 0.02). Total hemoglobin loss was statistically greater in the 50-mg/kg group compared with the 150-mg/kg group (p = 0.04). There was no statistical difference in blood tranfusion rate or coagulation profiles among the three groups. However, preoperative hemoglobin level was statistically lower in the 150-mg/kg group compared with the other two groups (p = 0.01).

CONCLUSION

Of the three doses of TA studied, the most efficacious and cost-effective dose to reduce bleeding after cardiac surgery with mild hypothermic systemic perfusion is 100 mg/kg.

Increased iron and ferritin content of sputum from patients with cystic fibrosis or chronic bronchitis

PURPOSE

Extracellular free iron, or iron bound to ferritin, may promote oxidative injury and bacterial growth in airways of patients with chronic airway inflammation due to cystic fibrosis (CF) or chronic bronchitis (CB). In this study, we assessed sputum content of total iron, ferritin, and transferrin in patients with CF or CB as well as sputum from normal subjects with acute airway inflammation caused by viral upper respiratory tract infections (URTIs).

METHODS

Spontaneously produced sputum was obtained from 33 subjects, including 10 subjects with CF, 18 subjects with CB (10 acute exacerbations, 8 with stable CB), and 5 subjects with URTIs (control subjects). After lysing and dilution, total iron concentrations were determined by controlled coulometry, ferritin was measured by radioimmunoassay, and transferrin was measured by enzyme-linked immunosorbent assay.

RESULTS

Iron was not present in detectable amounts in control sputums, but ferritin was present (6+/-2 ng/mg protein, mean+/-SE), as was transferrin (2.37+/-0.44 microg/mg). Compared with control subjects, concentrations of iron in sputum were increased in patient groups with higher amounts in CF patients (242+/-47 ng/mg, p<0.01) than CB patients with acute exacerbations or patients with stable CB (98+/-50 and 42+/-12 ng/mg, p<0.05 for both). Ferritin content of sputum was also increased in each group, with CF patients (113+/-22 ng/mg, p<0.001) higher than CB patients (acute, 45+/-10 ng/mg; stable, 87+/-24 ng/mg; p<0.01 for both). Compared with control subjects, sputum transferrin was decreased in CF patients (1.09+/-0.40 microg/mg, p<0.05), but not CB patients.

CONCLUSIONS

These findings indicate there are increased airway concentrations of total iron and ferritin-bound iron in patients with CB and, to a greater extent, in patients with CF. Particularly in CF patients who also demonstrated decreased airway concentrations of transferrin, ferritin-bound iron in airways may promote oxidative injury and enhance bacterial growth.

Differential expression of synaptosome-associated protein 25 kDa [SNAP-25] in hippocampi of neonatal mice following exposure to human influenza virus in utero

We investigated the role of maternal exposure to human influenza virus [HI] in C57BL/6 mice on day 9 of pregnancy on the hippocampal expression of SNAP-25 in postnatal day 0 neonates, and compared them to sham-infected pups. The expression of SNAP-25 in infected neonates varied along the septotemporal axis of hippocampus and in various anatomic layers. Quantitative densitometric analysis of specific immunogold silver-enhanced SNAP-25 immunoreactivity [IR] showed increases of 40-347% over control in all septal-dorsal hippocampal layers except for the subplate layer. In mid septo-temporal hippocampus, SNAP-25 IR increased by 10-114% over control in all layers, except for the hippocampal plate, but the extent of this increase was smaller than in the dorsal-septal area. Finally,in temporal-ventral levels, SNAP-25 expression was reduced in all infected layers by 21-33% below control except for mild increases of 8.8 and 10% in subplate and hippocampal plate layers. Additionally, the infected SNAP-25 maximal density bin shifted to lower values dorsally and to higher values medially, with ventral maximal bins remaining unchanged when compared to controls. The differential expression of SNAP-25 in the hippocampi of infected neonates indicates a variable degree of vulnerability across the septo-temporal axis of hippocampus. It is surmised that while viral infection may induce excitotoxicity in the ventral hippocampus, it may cause reactive synapto-genesis in the medial and dorsal sectors of the developing brains of postnatal day 0 neonates.

Treatment with either high or low frequency TENS reduces the secondary hyperalgesia observed after injection of kaolin and carrageenan into the knee joint

For years, physical therapists have been utilizing a variety of modalities, including transcutaneous electrical nerve stimulation (TENS), in an attempt to manage pain associated with inflammation. However, the data on clinical effectiveness is conflicting and the neurophysiological mechanism of action is not known. The purpose of this study was to investigate the effects of high and low frequency TENS on the secondary hyperalgesia that occurs after joint inflammation. Secondary hyperalgesia is thought to reflect changes in central neurons and is thus a measure of activity of central neurons. This study utilized the kaolin and carrageenan model of knee joint inflammation and measured the effects of TENS treatment on paw withdrawal latency to radiant heat (secondary hyperalgesia), spontaneous pain behaviors and joint circumference. Either high (100 Hz) or low (4 Hz) frequency TENS was applied to the knee joint for 20 min after the development of hyperalgesia. Both high and low frequency TENS resulted in a reversal of the hyperalgesia immediately following treatment. The effects of high frequency TENS lasted through at least 24 h while those of low frequency TENS lasted through 12 h. There was no effect of TENS on spontaneous pain behaviors or joint swelling when compared to controls. Thus, TENS appears to be more effective in reducing referred pain (or secondary hyperalgesia) without affecting guarding or splinting of the affected limb. Thus, clinically, the choice to use TENS may depend on patient symptoms; specifically TENS should be effective in reducing referred or radiating pain.

Potential role of epithelial cell-derived histone H1 proteins in innate antimicrobial defense in the human gastrointestinal tract

In the human gastrointestinal tract, microorganisms are present in large numbers in the colon but are sparse in the proximal small intestine. In this study, we have shown that acid extracts of fresh human terminal ileal mucosal samples mediate antimicrobial activity. Following cation-exchange chromatography, one of the eluted fractions demonstrated antibacterial activity against bacteria normally resident in the human colonic lumen. This activity was further fractionated by reverse-phase high-performance liquid chromatography and identified as histone H1 and its fragments. We have also shown that in tissue sections, immunoreactive histone H1 is present in the cytoplasm of villus epithelial cells. In vitro culturing of detached (from the basement membrane) villus epithelial cells led to the release of antimicrobial histone H1 proteins, while the cells demonstrated ultrastructural features of programmed cell death. Our studies suggest that cytoplasmic histone H1 may provide protection against penetration by microorganisms into villus epithelial cells. Moreover, intestinal epithelial cells released into the lumen may mediate antimicrobial activity by releasing histone H1 proteins and their fragments.

Human influenza viral infection in utero increases nNOS expression in hippocampi of neonatal mice

We investigated the role of maternal exposure to human influenza virus (HI) in C57BL/6 mice on day 9 of pregnancy on hippocampal expression of nNOS in day 0 neonates and compared that to sham-infected pups. Qualitative analysis using polyclonal antibody to nNOS showed overall increases in immunoreactivity (IR) in hippocampal and dentate layers of day 0 infected neonates when compared to sham-infected animals. These increases in nNOS immunoreactivity were pronounced in hippocampal plate, intermediate, molecular, subplate, and dentate areas. Quantitative analysis of specific immunogold silver-enhanced nNOS IR via densitometry showed nNOS IR increases of 26-71.6% in all layers, i.e., hippocampal plate (35.1%), dentate area (71.6%), molecular area (43.75%), subplate (45.7%), and intermediate zone (26%) in infected neonatal brains vs. controls. The changes in levels of nNOS expression in hippocampi of neonates born to mothers exposed to HI virus during the second trimester of pregnancy may reflect the potential for glutamatergic excitotoxicity via activation of NMDA receptors in the developing brains of these neonatal mice.

Dietary Fusarium moniliforme culture material induces in vitro tumor necrosis factor-alpha like activity in the sera of swine

Sera obtained from a group of pigs (n = 5) fed a diet amended with fumonisin containing Fusarium moniliforme culture material was used to determine the levels of Tumor Necrosis Factor-Alpha (TNF) activity by a functional bioassay utilizing the TNF sensitive WEHI 140 mouse fibrosarcoma cell line. Two pigs developed signs consistent with pulmonary edema which was confirmed by pathologic examination in only one pig. Significant, time dependent increases in TNF-like activity were observed in all pigs during the five days of the trial. Another group of pigs (n = 5) was given a defined daily dose of the same culture material by gastric intubation. Two pigs developed fulminant pulmonary edema and sharp increases in TNF activity were observed during the 3 days of the trial in all pigs. In both cases the activity was not abrogated by addition of a neutralizing anti-human TNF monoclonal antibody suggesting that other factors may have been responsible for these effects, possibly the increased levels of sphingoid bases in the serum. Since the pig has become an important model in the study of TNF mediated endotoxic shock, these studies illustrate the relevance of certifying the absence of this important mycotoxin from corn based animal diets, specially if functional assays are used to monitor the activity of TNF in serum.

Actin is cleaved during constitutive apoptosis

Proteases play an important role in the programme of cell death by apoptosis but little is known of the substrates cleaved, particularly in constitutive models of this type of cell death. Neutrophils spontaneously undergo apoptosis in culture without requiring external stimuli. During this process we found biochemical and immunochemical evidence for the cleavage of membrane-associated actin, a component of the cytoskeleton that links polymerized actin to the plasma membrane. Cleavage occurred at a single site at the N-terminus, between residues Val43-Met44, a site devoid of a consensus motif for cleavage by cysteine proteases of the interleukin-1beta-converting enzyme (ICE)-family. Whereas actin cleavage and nuclear/cell surface markers of apoptosis were co-ordinately diminished by zVAD-fmk, an inhibitor of the ICE-like family of proteases, only acetyl-leucyl-leucylnormethional, an inhibitor of calpains, was capable of completely inhibiting actin cleavage. Our results suggest that actin is not a direct substrate for the ICE-like family of proteases. By disabling the cytoskeleton, actin cleavage may be an important component in the capacity of apoptosis to reduce the injurious potential of neutrophils.

Assessment of painful episode frequency in sickle-cell disease

Frequency of painful episodes in sickle-cell disease is considered to be related to clinical severity and possibly to other aspects of the disease. Measurements of frequency often include only hospital-related or more severe, longer-lasting episodes. Since painful episodes, however, may regularly occur in nonhospital settings or be shorter-lasting with possible different pathologic effects, we measured all painful episodes in 10 adults with sickle-cell disease for 1.0-3.8 years, using a daily questionnaire. The results were related to other indices of disease severity and to possible precipitating factors, such as cold weather and menses. Sixty-one percent (on average) of the total number of episodes (243) were nonhospital-related, and 33% (on average) were shorter-lasting. Episode frequencies, whether determined as total, hospital-related, nonhospital-related, or shorter-lasting, were not related to each other or to other indicators of disease severity. The highest incidence of episode frequency occurred in the winter. The association of episodes with menses was moderately close in individual patients. The findings suggest that nonhospital-related painful episodes and shorter-lasting episodes may contribute significantly to episode frequency. Measurement of frequency of all painful episodes would require consideration when evaluating episode frequency and its relationship to disease severity, to possible precipitating factors of episodes, and to treatment of the disease, and for study of the natural course of the disease.

In vivo anti-influenza virus activity of a zinc finger peptide

Matrix protein (M1) is a major structural protein of influenza virus, and it inhibits its own polymerase. A 19-amino-acid peptide, corresponding to a zinc finger region of the M1 sequence of influenza virus strain A/PR/8/34 (H1N1), centered around amino acids 148 to 166, was synthesized. This peptide, designated peptide 6, represents a zinc finger which includes a 7-amino-acid loop or finger and a 4-amino-acid tail at the carboxyl terminus, in addition to the 8 amino acids involved in the coordination of Zn. Three experiments were run to evaluate the activity of peptide 6 on infections induced in mice by influenza A/PR/8/34 and A/Victoria/3/75 (H3N2) viruses. Intranasal (i.n.) treatment of the H1N1 virus infection with 30 or 60 mg/kg of body weight/day, three times daily for 5 days, beginning 4 h pre-or 8 h post-virus exposure, was effective in preventing death, reducing the arterial oxygen decline, and inhibiting lung consolidation. Virus titers in the lungs determined on day 5 were reduced by up to 1.5 log10 in treated groups, but considerable variation in the titers of the recovered virus was seen. The H3N2 virus infection was treated i.n. with 30, 60, or 120 mg of peptide 6/kg/day by using the above-mentioned delayed initiation treatment schedule, and similar protection was seen, although lung virus titers were not reduced in the day-5 assay. Peptide 6 was well tolerated at doses up to 60 mg/kg/day. This zinc finger peptide may provide a new class of antivirals effective against influenza virus.

Rapid lung cytokine accumulation and neutrophil recruitment after lipopolysaccharide inhalation by cigarette smokers and nonsmokers

Inhalation of lipopolysaccharide (LPS) by humans rapidly recruits neutrophils to alveolar structures. Recruitment of neutrophils may be mediated in part by intrapulmonary release of cytokines such as tumor necrosis factor-alpha, interleukin (IL)-1beta, and IL-8, although the kinetics of cytokine accumulation and neutrophil recruitment to the lungs after LPS inhalation have not been determined. Release of some cytokines in response to LPS is reported to be decreased in smokers' alveolar macrophages compared with nonsmokers', suggesting responses to LPS may differ in smokers (S) and nonsmokers (NS). To assess the kinetics of early cytokine accumulation after LPS inhalation and to compare inflammation induced in LPS-exposed S and NS, we performed bronchoalveolar lavage (BAL) in 28 subjects (14 NS and 14 S) at 90 or 240 minutes after inhalation of aerosolized LPS (30 microg). BAL performed at 90 and 240 minutes after LPS inhalation recovered increased numbers of neutrophils and lymphocytes in both NS and S compared with an unexposed control group (10 NS, 10 S), with greater recovery of neutrophils in S than NS (p < 0.001). BAL fluid supernate concentrations of IL-8, IL-1beta, and tumor necrosis factor-alpha at 90 minutes were increased in S and NS compared with an unexposed control group. IL-8 and tumor necrosis factor-alpha concentrations were similar in S and NS; however, IL-1beta concentrations were greater in S (p < 0.005). BAL fluid concentrations of IL-1beta and IL-8 at 90 minutes correlated with absolute neutrophil recovery in S and NS. These findings suggest that the rapid accumulation of cytokines, particularly IL-1beta and IL-8, contributes to lung neutrophil recruitment after LPS inhalation. In addition, parameters of pulmonary inflammation present in S after LPS inhalation are similar to or increased compared with those present in NS.

Extraction and protein sequencing of immunoglobulin light chain from formalin-fixed cerebrovascular amyloid deposits

Substantial amounts of a single protein have been extracted into electrophoresis sample buffer from archived formalin-fixed brain blood vessels, taken from a case of cerebral amyloidosis. Cyanogen bromide cleavage and tryptic digestion of the protein on Western blots allowed amino acid sequences from three resultant peptides to be determined. Comparison of these peptides with database sequences identified the extracted protein as being derived from an immunoglobulin light chain. This is the first demonstration of amino acid sequencing of a polypeptide extracted from formalin-fixed tissue. This case also appears to be unique, since primary cerebrovascular amyloidosis involving immunoglobulin light chains has not been previously described. The amyloid protein had clearly resisted formalin fixation; it is possible that this resistance occurred because the protein was deposited in large amounts as insoluble densely packed aggregates, which may exclude infiltration of the formalin. This technique may therefore have applications in the post-mortem diagnosis of amyloidoses and in the purification of other amyloids.

Gene transfer by adenovirus in smooth muscle cells

We report adenovirus-mediated gene transfer into airway smooth muscle cells in cultured cells and organ-cultured tracheal segments. Incubation of cultured rat tracheal myocytes with virus (5 x 10(8) pfu/ml) for 6 h resulted in beta-galactosidase expression in 94.8 +/- 2.5% of cells (n = 4). Following incubation of thin (less than 200 microns diameter) equine trachealis muscle segments with virus in organ culture (5 x 10(8)-5 x 10(10) pfu/ml) the average expression of the Lac Z gene was approximately 19 +/- 10% (n = 9). Expression was markedly improved, however, in segments from neonatal rats (13-21 days). In two experiments in which the mucosa and serosa were removed, nearly all cells expressed beta-galactosidase, whereas in a third experiment in which the tissue was not dissected, about 40% of cells were stained. Viral infection had no effect on tension development of strips following organ culture. In vitro gene transfer may provide a useful method to alter protein expression and examine the effect of this alteration on excitation/contraction coupling in smooth muscle.

HDL subparticles and coronary artery disease in NIDDM

Decreased HDL cholesterol levels are associated with an increased risk of coronary artery disease (CAD) in non insulin dependent diabetes mellitus (NIDDM). The aim of this study was to compare HDL subparticles with apo A-I (LpAI) and those with apo A-I and apo A-II (LpAI/AII) in subjects with and without NIDDM and to study the relationship between HDL subparticles and CAD in NIDDM. Lipids, apo A-I and HDL subparticles were measured in 240 subjects with NIDDM and in 248 age and gender matched controls. Subjects with NIDDM had higher triglyceride levels (2.5 +/- 1.8 vs. 1.4 +/- 0.8 mmol/1, P < 0.001), lower HDL cholesterol (0.9 +/- 0.3 vs. 1.2 +/- 0.3 mmol/l, P < 0.001), apo A-I (124.7 +/- 22.4 vs. 139.8 +/- 24.1 mg/dl, P < 0.001) and LpAI/AII (82.4 +/- 18.2 vs. 94.9 +/- 16.7 mg/dl, P < 0.001) in comparison to controls. LpAI levels were similar in both groups. Diabetic subjects with CAD (n = 109) had higher triglycerides (2.7 +/- 1.9 vs. 2.3 +/- 1.8 mmol/l, P = 0.02) and lower HDL cholesterol (0.8 +/- 0.2 vs. 1.0 +/- 0.3 mmol/l, P <0.001), apo A-I (115.5 +/- 20.1 vs. 132.3 +/- 21.4 mg/dl, P < 0.001), LpAI (40.2 +/- 9.1 vs. 44.4 +/- 12.4 mg/dl, P = 0.06), and LpAI/AII levels (75.4 +/- 18.0 vs. 88.3 +/- 16.2 mg/dl, P < 0.001) in comparison to diabetic subjects without CAD (n = 131). In a multivariate analysis, apo A-I was found to be the best predictor of CAD in subjects with NIDDM. In conclusion, reduced HDL cholesterol levels found in NIDDM are, principally, due to reduced concentrations of apo A-I and apo A-II-containing particles (LpAI/AII). While LpAI and LpAI/AII levels were lower in NIDDM subjects with CAD, plasma apo A-I is the best predictor of CAD in NIDDM.

A rational approach to regulation of gene therapy in Canada

Gene therapy offers prospects of dramatically improved treatments for and possibly true cures of previously intractable diseases, and has therefore attracted much public interest and hopeful expectation. At the same time, it involves new and exploratory techniques and potential risks to patients. The definition of a drug in the Canadian Food and Drugs Act clearly includes materials used to effect gene therapy and also the products of genetic manipulations. The regulatory framework in Canada is based on risk management. The potential hazards and benefits of gene therapy and similar interventions will be assessed for categorization according to risk and an appropriate level of control, with the additional principle of deriving positions that are harmonized with those of counterpart regulatory agencies.

Evidence against the exon theory of genes derived from the triose-phosphate isomerase gene

The exon theory of genes proposes that the introns of protein-encoding nuclear genes are remnants of the DNA spacers between ancient minigenes. The discovery of an intron at a predicted position in the triose-phosphate isomerase (EC 5.3.1.1) gene of Culex mosquitoes has been hailed as an evidential pillar of the theory. We have found that that intron is also present in Aedes mosquitoes, which are closely related to Culex, but not in the phylogenetically more distant Anopheles, nor in the fly Calliphora vicina, nor in the moth Spodoptera littoralis. The presence of this intron in Culex and Aedes is parsimoniously explained as the result of an insertion in a recent common ancestor of these two species rather than as the remnant of an ancient intron. The absence of the intron in 19 species of very diverse organisms requires at least 10 independent evolutionary losses in order to be consistent with the exon theory.

The nurse as an educator

The rapidly changing healthcare system offers challenges and opportunities for nurse educators. Increasing evidence of health promotion/consumer empowerment, cost containment, increase in chronic illness, and the continued expansion of medical technology requires nurses with broad educational competencies. These competencies include preceptoring, patient education, and formal presentation skills. In this article, the authors describe the development and implementation of a multifaceted staff development curriculum designed to support the nurse as an educator.

Hyperoxia amplifies TNF-alpha production in LPS-stimulated human alveolar macrophages

Human alveolar macrophages (AM) produce a number of inflammatory mediators including tumor necrosis factor (TNF). TNF-alpha has been implicated in several forms of lung injury including that associated with oxygen toxicity. To investigate whether oxygen could induce or augment the release of TNF from AM, we acquired AM from nonsmoking volunteers and determined TNF release after in vitro hyperoxia. Although TNF release was not induced by oxygen exposure alone, if lipopolysaccharide (LPS) stimulation occurred simultaneously, there was significant augmentation by 60 and 95% oxygen over LPS-stimulated AM exposed to 21% oxygen. This increase was paralleled by a significant increase of interleukin (IL)-1 beta. Dimethylthiourea (DMTU), a hydroxyl radical scavenger, inhibited this release. The increase in TNF extracellular concentrations induced by hyperoxia was not associated with significant increases in intracellular concentration or detectable mRNA over LPS-stimulated AM exposed to 21% oxygen. We hypothesize that hyperoxia exposure may alter the LPS-stimulated AM cytoplasmic milieu, thus further enhancing TNF-alpha production by a post-transcriptional mechanism.

Smoking in hotels: prevalence, and opinions about restrictions

Exposure to high levels of environmental tobacco smoke can occur in hotels. Controversy exists about smoking regulation on licensed premises. This survey of 138 people attending one of three Newcastle hotels during 1993 found that 57 per cent of respondents were nonsmokers. Fifty-eight per cent (95 per cent confidence interval (CI) 50 to 66 per cent) of respondents in these hotels believed their health was being adversely affected by other people's smoke in the hotel. Seventy per cent (CI 62 to 78 per cent), including half the smokers, were in favour of restriction of smoking in the hotels. Most preferred the establishment of smoke-free areas to the introduction of total smoking bans in hotels. The failure of hotels to regulate smoking suggests that a legislative approach is required. The case for legislation would be strengthened by a larger study elsewhere in Australia.

The role of lipoprotein A-I and lipoprotein A-I/A-II in predicting coronary artery disease

The aim of this study was to examine the role of HDL subparticles with apolipoprotein (apo) A-I alone (LpA-I) and with apoA-I and apoA-II (LpA-I/A-II) in predicting coronary artery disease. Concentrations of these HDL subparticles were compared in 184 subjects with angiographically confirmed significant coronary artery disease (> 50% stenosis of at least one vessel) and 191 age- and sex-matched control subjects without clinical coronary artery disease. LpA-I and LpA-I/A-II were measured with magnetic beads coated with anti-apoA-II antibodies to separate particles containing apoA-II from plasma. Total plasma cholesterol and triglyceride levels were similar in both groups. Although subjects with coronary artery disease had lower HDL cholesterol, plasma apoA-I, LpA-I, and LpA-I/A-II than age- and sex-matched control subjects without coronary artery disease, plasma apoA-I was the best predictor of coronary artery disease. In conclusion, LpA-I and LpA-I/A-II are lower in subjects with coronary artery disease but do not add to plasma apoA-I in predicting the presence of coronary artery disease.