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ABSTRACTThis study aimed to use a coach-led digital health platform to mitigate burnout and enhance wellbeing among hospital workers. Individual interviews were conducted with 11 healthcare workers to explore their experiences of working with a coach through text-based communication on a digital support platform. Interviews were analysed using thematic analysis. Three overarching themes were identified: (1) Human-centred Conversation, Facilitated Awareness, (2) Learning and Growth, (3) Forward Momentum in the pillars of Lifestyle Medicine. Participants had a positive human-centered connection with their coach and felt safe to communicate openly with her via online chat messages. The coach facilitated participants’ awareness, learning and growth by helping them to identify the goals they wanted to achieve. Participants experienced forward momentum in the pillars of Lifestyle Medicine, including sleep, relationships, meaning and purpose in life, exercise, eating well, along with reduced loneliness and burnout. This study found that participants can experience an inherently human-centred connection through text-based communication with an online coach. There were some limits to this connection, including individual preferences and beliefs in relation to the digital means of communication. Participants felt connected to their coach and experienced benefits that extended beyond achieving individual goals to improving their lifestyle and wellbeing.

Disorders of sex development (DSDs) are a diverse group of conditions where the chromosomal, gonadal or anatomical sex can be atypical. The highly heterogeneous nature of this group of conditions often makes determining a genetic diagnosis challenging. Prior to next generation sequencing (NGS) technologies, genetic diagnostic tests were only available for a few of the many DSD-associated genes, which consequently had to be tested sequentially. Genetic testing is key in establishing the diagnosis, allowing for personalised management of these patients. Pinpointing the molecular cause of a patient’s DSD can significantly impact patient management by informing future development needs, altering management strategies and identifying correct inheritance pattern when counselling family members. We have developed a 30-gene NGS panel, designed to be used as a frontline test for all suspected cases of DSD (both 46,XX and 46,XY cases). We have confirmed a diagnosis in 25 of the 80 patients tested to date. Confirmed diagnoses were linked to mutations in AMH, AMHR2, AR, HSD17B3, HSD3B2, MAMLD1, NR5A1, SRD5A2and WT1which have resulted in changes to patient management. The minimum diagnostic yield for patients with 46,XY DSD is 25/73. In 34/80 patients, only benign or likely benign variants were identified, and in 21/80 patients only variants of uncertain significance (VOUS) were identified, resulting in a diagnosis not being confirmed in these individuals. Our data support previous studies that an NGS panel approach is a clinically useful and cost-effective frontline test for patients with DSDs.

Multiple myeloma (MM) is characterized by the clonal expansion and metastatic spread of malignant plasma cells to multiple sites in the bone marrow (BM). Recently, we implicated the sialyltransferase ST3Gal-6, an enzyme critical to the generation of E-selectin ligands, in MM BM homing and resistance to therapy. Since E-selectin is constitutively expressed in the BM microvasculature, we wished to establish the contribution of E-selectin ligands to MM biology. We report that functional E-selectin ligands are restricted to a minor subpopulation of MM cell lines which, upon expansion, demonstrate specific and robust interaction with recombinant E-selectin in vitro. Moreover, an increase in the mRNA levels of genes involved in the generation of E-selectin ligands was associated with inferior progression-free survival in the CoMMpass study. In vivo, E-selectin ligand-enriched cells induced a more aggressive disease and were completely insensitive to Bortezomib. Importantly, this resistance could be reverted by co-administration of GMI-1271, a specific glycomimetic antagonist of E-selectin. Finally, we report that E-selectin ligand-bearing cells are present in primary MM samples from BM and peripheral blood with a higher proportion seen in relapsed patients. This study provides a rationale for targeting E-selectin receptor/ligand interactions to overcome MM metastasis and chemoresistance.

N-face AlGaN (cap)/GaN (channel)/AlGaN (barrier)/GaN (buffer) high electron mobility transistors (HEMTs) provide a simple solution for strong confinement of the two-dimensional electron gas (2DEG) from the back since carriers are induced on top of the AlGaN barrier. To reduce the adverse effects of random alloy scattering from the AlGaN barrier, an N-face GaN-spacer HEMT was designed with an epi-structure consisting of an AlGaN (cap)/GaN (channel)/AlN/GaN (spacer)/AlGaN (barrier)/GaN (buffer). The 2DEG is confined at the GaN (channel)/AlN interface, while the GaN-spacer layer separates the 2DEG from the AlGaN barrier. The large polarization-induced electric field of the AlN and its large conduction band discontinuity with GaN provide strong confinement for good pinch-off and low output conductance under high electric fields. Up to 20% improvement in electron mobility was measured in these devices. The devices showed a current gain cut-off frequency (ft) of 24 GHz and power gain cut-off frequency (fmax) of 44 GHz for a nominal gate length of 0.7 μm. An output power density of 4.5 W/mm was measured at 4 GHz, with 34% power added efficiency and a gain of 10.3 dB at a drain bias of 40 V. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

2-year greenhouse study was conducted at Clemson University, Clemson, S.C., in 2003 and 2004 to determine drought responses of six bermudagrass (Cynodon spp.) cultivars at four irrigation intervals. Cultivars selected from the 2002 National Turfgrass Evaluation Program Bermudagrass Trial were 'SWI-1012', 'Arizona Common', 'Tift No.3', 'Tifsport', 'Aussie Green', and 'Celebration'. Treatments included 5-, 10-, and 15-day irrigation intervals plus a control (irrigated daily). Volumetric soil water content (VSWC) and evapo-transpiration (ET) rates were recorded every 3 days. Turfgrass quality (TQ) was observed weekly and root weight was measured at the end oft 6-week study. 'Aussie Green' and 'Celebration' produced the highest TQ rating (>7) at week 4 when watered daily. After 4 weeks of the 5-day irrigation interval, all cultivars showed unacceptable quality ratings (<7). However, 'Aussie Green' and 'Celebration' were able to maintain an acceptable TQ rating (7), compared to 'Arizona Common' (5.1) and 'Tift No.3' (5.8) at week 2 (5-day treatment). 'Celebration' produced 114% and 97% greater root weight than 'Tifsport' and 'Aussie Green', respectively, when pooled across all irrigation treatments. At the 15-day irrigation interval treatment, six bermudagrass cultivars pooled together produced 78%, 22%, and 11% greater root weight vs. control, 5-day, and 10-day treatments, respectively. When pooled for all treatments, 'Aussie Green' and 'celebration' VSWC was 5% and 7% lower than 'Tift No.5', and ET rates were 26% and 30% greater than 'Arizona Common'. Based on these results, irrigating bermudagrass in 5-day intervals should be carefully monitored. [ABSTRACT FROM AUTHOR]

We demonstrate the direct wafer bonding of GaN and ZnSe-based materials. We report on the structural, optical, and electrical characteristics of InGaN/GaN light-emitting diodes (LEDs) and ZnSe-based II–VI materials combined by direct wafer bonding. Reflectivity, transmission electron microscopy (TEM), and current–voltage (I –V ) measurements were performed. The bonded sample exhibited a higher reflectivity at the wavelength of 510 nm than a control LED with an Al cap. Cross-sectional TEM revealed a uniform wafer-bonded interface with no voids or cavities for the low temperature sample, while the sample bonded at a higher temperature was observed to have lens-shaped cavities at semiconductor interfaces. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The aim of the present study was to determine the apparent diffusion boundary layer and dissolution rate constant for various surfaces of compacts and at various locations in the USP paddle dissolution apparatus. Benzoic acid compacts were coated with paraffin wax leaving only the surface under investigation free for dissolution. The dissolution rates for various surfaces at varying locations in the paddle dissolution vessel were determined from the slope of the dissolution profile (amount dissolved (mg) versus time (min)). The apparent diffusion boundary layer and dissolution rate constant were calculated and were found to vary depending on the surface of the compact from which dissolution took place and also on the location and size of the compact. It may be concluded that, in developing models to describe the dissolution from solid dosage forms, it is not accurate to assume constant hydrodynamics and mass transfer rates at all surfaces of the system, or in different locations within the test device. A more exact description of the hydrodyn amics would be necessary in order to precisely model drug dissolution in the paddle dissolution apparatus.

The bioavailability of sediment bound contaminants in lentic (Hamilton Harbour, Lake Ontario) and lotic (Detroit River connecting Lakes St. Clair and Erie) environments were assessed by a battery of multi-trophic tests using laboratory grown organisms. Hamilton Harbour is a hyper-eutrophic and highly contaminated environment due to extensive urban and industrial growth, while the Detroit River has been implicated as a major source of contaminants to Lake Erie. An array of sites across Hamilton Harbour and the Detroit River were selected, including the mouth of the Rouge River as well as the Trenton Channel—the contaminated western arm of the Detroit River. Multi-trophic acute assays were conducted using Daphnia magna, Hyalella azteca, Diporeia hoyi, and Lumbriculus variegatus. While the tests were consistent in determining the most toxic hot spots, variability existed in the sensitivities of test organisms to discriminate among less contaminated sites. The most toxic sediment in the Detroit River was at the mouth of the Rouge River, while the site in Windermere Basin in Hamilton harbour was found to be deleterious. The results indicated that the toxicity in a lotic ecosystem such as the Detroit River was caused by both the bottom sediments and the mobile seston component which contributed to the water-borne toxicity. Conversely, lentic and undisturbed ecosystems such as Hamilton Harbour contain much of their toxic component in the bottom sediments and not in the overlying water column. The multi-trophic battery of test approach adopted in our study appears to be effective in detecting and discriminating differential sensitivities of sediment bound contaminants in both lentic and lotic ecosystems. This battery of tests approach needs continued modification, development, and improvement to keep the assays up-to-date, sensitive, cost effective and adaptable in discriminating complex mixtures of sediment bound contaminants found in natural ecosystems.

The study examined the influence of the Pond Report on the teaching of medical ethics in the London medical schools. A questionnaire was given to both medical students and college officers. All medical colleges reported that ethics was included in the curriculum. However, from students' replies, it seems that attendance of optional courses is low and that not all current final year medical students have had any formal teaching in medical ethics. Stronger guidelines are necessary to ensure appropriate ethical training in London medical schools.

The tear resistance of multi-layered plastic films can be generally predicted from the tear resistance of individual layers by an additive rule. The most notable exception from this additive rule is the case of multi-layered films containing a polyethylene layer. The reason for this specific case is explained by the constraint on the plastic yield zone of polyethylene, which causes a dramatic drop in the tear resistance of the multi-layered film. An extensive plastic zone is generated during the tear fracture of a single layer polyethylene film. This yield zone does not appear when polyethylene is laminated with other polymer films.

A glass capillary gas chromatographic system using simultaneous flame ionization (FID) and electron capture (ECD) detection has been employed for the analysis of trace volatile organic pollutants in a municipal drinking water supply. The use of dual detectors with glass capillary columns allows resolution and detection of both halogenated and non-halogenated compounds simultaneously at less than microgram per liter (ppb) concentrations. By using diethyl ether as a solvent in preparing standard solutions of volatile organic compounds, standardization is made more accurate due to a reduction in solvent masking of early eluting peaks of interest. Additionally, ether shows promise for use in an internal standard method for quantification of VOA. These techniques were found to alleviate problems previously encountered in the analysis of purgeable organics and are described.

Mobilization of a distinct subset of specific granules provides a physiologically important mechanism to recruit Mac-1 (CD11b/CD18) from an intracellular pool to the external surface of the neutrophil plasma membrane, where the functionally active heterodimer mediates several adherence-dependent processes that are crucial for adequate host defense and cellular inflammatory responses. We observed similar characteristics for translocation of Mac-1 and neutrophil formyl peptide receptors (FPR) and hypothesize that the readily accessible pools of both Mac-1 and FPR are colocalized within this specific granule subset. Plasma membrane levels of both FPR (assessed with 3H- FMLP) and Mac-1 (assessed by fluorescence-activated cell sorter analysis of fluorescein isothiocyanate [FITC]-Mo-1-labeled cells) were markedly downregulated in cells prepared at low temperature from blood cooled to 4 degrees C immediately after removal from the circulation. Levels of both FPR and Mac-1 remained low on cells held at 4 degrees C. Upon warming, spontaneous upregulation of Mac-1 and FPR occurred with similar kinetics and temperature dependency. Translocation of both Mac- 1 and FPR was markedly potentiated by exposure of cells to either fluoride ion (which has been shown by others to specifically elicit exocytosis of gelatinase-rich and vitamin B-12 binding protein-poor granules) or granulocyte-macrophage colony-stimulating factor (GM-CSF), a cytokine that markedly potentiates the neutrophils' host defense capabilities. Levels of both FPR and Mac-1 on F-- or GM-CSF-treated neutrophils exceeded those present on cells incubated at 37 degrees C for extended time intervals, indicating that stimulated translocation may involve mobilization of an additional granule subset. Scatchard analysis showed that only low-affinity FPR were translocated during spontaneous and stimulus-dependent upregulation. To directly compare FPR levels on the surface of cells displaying varying levels of Mac-1 within a single cell suspension, cells were labeled with FITC-Mo-1 and sorted into subpopulations based on fluorescence intensity. After sorting, the individual populations were held at 4 degrees C to prevent further spontaneous upregulation, concentrated by centrifugation, and assayed for FPR levels. Under a variety of conditions, FPR levels correlated with Mac-1 (CD11b) expression on cell populations selected on the basis of CD11b fluorescence intensity. Analysis of subcellular fractions obtained from disrupted neutrophils before and after upregulation provided additional support for the hypothesis that Mac-1 and FPR are colocalized within a readily accessible subset of neutrophil granules.

The strength and toughness of soda-lime (container) glass have been enhanced by factors of ~ 2 and ~ 40, respectively, by a 0.1 mm coating of polyurethane containing 6–9 wt% silicon carbide whiskers in random orientation. The strength measurements were made using a standardized procedure and a biaxial ring-on-ring flexure rig. The toughness enhancement has been shown to be due to crack-branching and fibre pull-out mechanisms in the coating, which bridges any strength-limiting flaws in the underlying glass.

The phytoplankton of North Channel in Lake Huron and its productivity was studied at 8 stations distributed across the channel during May to October, 1974. The phytoplankton analysis was conducted using the Utermohl technique. The mean percent biomass at each station indicated Diatomeae (59–77%) and phytoflagellates such as Chrysophyceae (4–21%) and Cryptophyceae (7–19%) as the dominant contributors. Seasonal variations of biomass ranged from 0.2 to 0.35 g·m-3 with a single peak during stratified conditions. Diatomeae dominated throughout the period of investigation followed by Chrysophyceae and Cryptophyceae. Biomass composition by size revealed the dominance of ultraplankton (5–20 µm) which contributed 29–68% to the total biomass. Species such as Fragilaria crotonensis, Tabellaria fenestrata, Synedra acus var. radians, Cyclotella comta and C. bodanica made substantial contributions during the unstratified and stratified conditions.

The environmental quality of the Rhone River (Switzerland-France) has been assessed with a geochemical survey of the pollutants bound to suspended sediments. Ten samples were collected between Lake Geneva and the Mediterranean Sea in Nobember 1989 by continuous flow centrifugation and analysed for grain size distribution, carbonate, organic C, N, forms of particulate P, trace metals, and organic compounds (chlorobenzenes, organochlorine pesticides, PCBs, and PAHs). Four bed sediment samples were also studied for comparative purposes. The suspended solids provide lower variance by parameter than the bed sediments and are clearly most suitable for synoptic monitoring.

Respiration was increased approximately 5-fold with 0.05 microM norepinephrine and to a maximum of 10-fold by 0.30 microM norepinephrine. Prazosin, an alpha-adrenergic blocking agent highly selective for alpha 1-type receptors, partially inhibited the response to norepinephrine (0.05 microM) by 20-25% at a concentration of 0.10-1 microM. In contrast, when the stimulus for respiration was provided by isoproterenol or 3-isobutyl-1-methylxanthine, prazosin was without effect up to a concentration of 10 microM. Yohimbine, an alpha-adrenergic blocking drug preferential for alpha 2-receptors, did not influence norepinephrine-stimulated oxygen uptake. Respiration was increased two- to fourfold by phenylephrine or methoxamine, agents preferential for alpha 1-adrenergic receptors but not at all by clonidine, an agent preferential for alpha 2-adrenergic receptors. The stimulatory effect of phenylephrine on oxygen uptake was fully blocked by prazosin but not propranolol. Removal of extracellular calcium with ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid prevented phenylephrine stimulation of respiration but was without effect when isoproterenol was the stimulus. These results support the participation of alpha 1-adrenergic receptors in control of respiration and are consistent with the possibility that changes in cell calcium are intimately involved in this response.

The action of endogeneous adenosine on isolated hamster brown adipocytes was examined. Adenosine production from brown adipocytes was measured after labeling of the intracellular nucleotide pool with [3H]adenine. Accumulation of [3H]adenosine in the incubation medium was maximum after 5 min of incubation and was still present after 20 min. When adenosine accumulation was prevented by addition of adenosine deaminase, the stimulatory effects of isoproterenol on oxygen uptake, lipolysis, and adenosine 3',5'-cyclic monophosphate (cAMP) generation were enhanced. However, basal rates of lipolysis and oxygen consumption and levels of cAMP were not affected on addition of adenosine deaminase. A similar potentiation of isoproterenol responses was produced by the adenosine receptor antagonist, 3-isobutyl-1-methylxanthine, present at a concentration (10 microM) which did not change basal levels of respiration or lipolysis. Addition of the adenosine analogue 2-chloroadenosine antagonized isoproterenol-stimulated respiration and lipolysis and prevented potentiation of isoproterenol responses with 3-isobutyl-1-methylxanthine. To localize the site of adenosine action, activity of adenylate cyclase in membrane preparations from brown adipocytes was measured. Isoproterenol-stimulated adenylate cyclase activity was partially inhibited by 2-chloroadenosine in a GTP-dependent manner. Addition of Na+ enhanced the inhibitory effect of 2-chloroadenosine, and 3-isobutyl-1-methylxanthine blocked it. The calculated 50% effective dose for 2-chloroadenosine inhibition was between 10 and 15 nM. These data suggest that adenosine produced by brown adipocytes is an endogenous regulator of respiration in these cells acting at the level of the adenylate cyclase enzyme.

In pentobarbital-anesthesized cats, bolus i.v. injections of sodium azide produced dose-dependent transient hypotension accompanied by a modest tachycardia and a brief hyperpnea. Intracerebroventricular injections of azide elicited graded effects similar to the i.v. doses, but the responses were slower in onset and could be delayed by occluding the cranial blood supply. This is interpreted to mean that intracerebroventricular azide acts systematically after escaping from the cerebrospinal fluid into the bloodstream. The hypotensive response to i.v. azide was not affected by cholinergic or adrenergic blockade or buffer nerve section. The tachycardia was blocked by sympathetic neural blockade or buffer nerve section indicating that it is a baroreflex response to the vasodepressor effect. Respiratory effects of bolus i.v. azide occurred independently of the hypotensive response and were abolished by peripheral chemodenervation. Infusion of azide facilitated CO2-tidal volume responsiveness in the steady state, an effect that was essentially eliminated by carotid sinus neurotomy. The azide did not affect the tidal volume-respiratory frequency relationship mediated by the pulmonary stretch receptors. Thus, the respiratory stimulant effect of azide in subtoxic doses is attributable to an excitatory action on the arterial chemoreceptors. Toxic doses of azide resulted in centrally mediated hypertension, tachycardia, cardiac arrhythmia, respiratory depression, seizures and death.

The impact of navigationally induced suspended sediments from the Upper Great Lakes Connecting Channels on the size-fractionated primary productivity was evaluated by the Carbon-14 technique. The method applied was on-site, rapid, sensitive, inexpensive, and provided dynamic-toxicological information essential for hazard assessment. Both enhancement and inhibition of the primary productivity was observed in various parts of the Upper Great Lakes Connecting Channels. These responses appear to depend on the type of natural plankton and their exposure to various contaminant/nutrient complexes generated by the disturbance of the bottom sediments during the passage of ships. Traditionally, only the inhibition of primary productivity has been monitored from a toxicity point of view, but it is important also to evaluate the implications of enhancement since it may result in increased eutrophication, propagation of nuisance blooms, and change of intricate food-web interactions. The procedure adopted in this study for the first time appears to possess considerable potential for a simple and rapid screening of environmental perturbations resulting from navigational activities.

The ecosystem health of stressed environments in the Great Lakes has been evaluated simultaneously by means of a battery of structural and functional tests based on current technology and involving various trophic levels. These tests attempt to assess ecosystem health at the organism level and simultaneously focus on water-borne and sediment-bound toxicities. The use of structural indicators has been successfully demonstrated. Similarly, functional tests were selectively chosen across various trophic levels and included size-fractionated primary productivity (filtered versus unfiltered assays), and Colpidium, Daphnia, Hyalella, and Pontoporeia assays. Some of the emerging techniques such as in situ plankton cages (I.P.C.), microcomputer-based chlorophyll fluorescence (Video Analysis System), and other assays are discussed. The multi-trophic and multi-disciplinary battery of tests followed in our laboratory adopts a field-to-laboratory approach. The availability of diverse bioassays have placed toxicologists and environmentalists in a position where they are now better equipped to probe the complexities of ecosystem health and its management.

The contamination of Toronto Harbour is a very serious problem. The major sources of pollution are the Don River and sewer outflows, as well as industrial, and municipal effluents. The problem is further compounded by perturbations of the toxic sediment caused by dredging, dredge-disposal, navigation, and recreational activities. The impact of contamination and nutrient enrichment was reflected in the size-fractionated primary productivity experiments. Generally, microplankton/netplankton (> 20 µm) productivity was enhanced whereas ultraplankton (< 20 µm) productivity was inhibited. These observations are attributable to interactions between ameliorating nutrients and toxic contaminants as well as to the differential sensitivity of natural phytoplankton size assemblages to the bioavailable chemical regime. In situ environmental techniques applied in Toronto Harbour were effective, sensitive, and rapid, and provided a better understanding of the impact of dredging/disposal activities under natural conditions. These techniques have great potential in the assessment of the ecotoxicology of harbours and other stressed environments.

The ability to carry out high-resolution genetic mapping at high throughput in the mouse is a critical rate-limiting step in the generation of genetically anchored contigs in physical mapping projects and the mapping of genetic loci for complex traits. To address this need, we have developed an efficient, high-resolution, large-scale genome mapping system. This system is based on the identification of polymorphic DNA sites between mouse strains by using interspersed repetitive sequence (IRS) PCR. Individual cloned IRS PCR products are hybridized to a DNA array of IRS PCR products derived from the DNA of individual mice segregating DNA sequences from the two parent strains. Since gel electrophoresis is not required, large numbers of samples can be genotyped in parallel. By using this approach, we have mapped > 450 polymorphic probes with filters containing the DNA of up to 517 backcross mice, potentially allowing resolution of 0.14 centimorgan. This approach also carries the potential for a high degree of efficiency in the integration of physical and genetic maps, since pooled DNAs representing libraries of yeast artificial chromosomes or other physical representations of the mouse genome can be addressed by hybridization of filter representations of the IRS PCR products of such libraries.

Terbinafine [(E)-N(6,6-dimethyl-2-hepten-4-ynyl)-N-methyl-1-naphthale nemethanamine], an antimycotic agent that inhibits fungal squalene epoxidase activity, was examined for its effects on platelet-derived growth factor (PDGF)-stimulated aortic smooth muscle cell DNA synthesis in vitro and neointimal proliferation in vivo. Exposure of bovine aortic smooth muscle cells to 0.25 to 25 microM terbinafine resulted in a concentration-dependent inhibition of PDGF-induced mitogenesis as determined by [3H]thymidine incorporation into DNA or cell number. The IC50 for inhibition of PDGF-stimulated smooth muscle cell DNA synthesis was approximately 5 microM. Micromolar concentrations of terbinafine also suppressed the mitogenic response to PDGF in fibroblasts. Neither the binding of [125I]PDGF to its plasma membrane receptors nor the uptake of [3H]thymidine or [3H]uridine was affected significantly by terbinafine. Oral administration of terbinafine (200 mg/kg/day) to rats for 2 days before and 14 days after balloon catheter injury to the carotid artery was associated with a 40% decrease in the area of the neointimal lesion. These observations indicate that terbinafine is both a potent in vitro antagonist of the smooth muscle cell mitogenic response to PDGF and an effective, well-tolerated p.o. active inhibitor of neointimal proliferation in vivo.

In the early 1990s, many Canadian pulp and paper mills implemented process changes to comply with new regulations that came into effect in 1993. These regulations placed stricter guidelines on a number of parameters in effluent discharges, including limits on acute toxicity, on the discharges of suspended solids, and on biochemical oxygen demand. To meet these new regulations, many of the older Canadian pulp and paper mills had to install secondary treatment systems. The investment by the Canadian pulp and paper industry was in excess of $5 billion, and the implementation of the new regulations and the process changes took several years. The new regulations were an extension of regulations designed in the early 1970s and were not designed specifically to address the reproductive responses recently reported in fish collected downstream of mills in Scandinavia and North America. This report describes a series of projects conducted between 1991 and 1996 to evaluate the effectiveness of the new regulations to address the issue of reproductive responses in fish associated with exposure to pulp-mill effluents. These studies have shown that the existing short-term bioassays do not adequately predict the potential of effluents to affect reproduction in wild fish. Laboratory testing using fathead minnows exposed over a full life cycle confirmed depression in sex steroid production, delay in sexual maturity, reduced egg production, and changes in secondary sex characteristics documented at some sites. Our studies demonstrated that both steroid hormone changes and induction of liver detoxification enzymes take place quickly. While short-term exposures can predict the potential of some effluents to impact steroid hormone production, there is no readily available assay that can be widely applied. In the absence of a usable and transferable laboratory bioassay, field collections were conducted at a number of sites. Generalizations are not possible at this time, but impacts have been seen at a variety of sites, and partial recovery has been documented at five sites in North America following various process and waste treatment changes. Data gaps and critical research areas are identified.

We have assembled a first-generation anchor map of the mouse genome using a panel of 94 whole-genome-radiation hybrids (WG-RHs) and 271 sequence-tagged sites (STSs). This is the first genome-wide RH anchor map of a model organism. All of the STSs have been previously localized on the genetic map and are located 8.8 Mb apart on average. This mouse WG-RH panel, known as T31, has an average retention frequency of 27.6% and an estimated potential resolution of 145 kb, making it a powerful resource for efficient large-scale expressed sequence tag mapping. [All of the mapping data for the maps presented here have been deposited at the Research Genetics, Inc., web site and can be freely accessed and downloaded at http://www.resgen.com/.]

Recent work has shown that MFO induction and loss of control of steroid hormone production occurs in fish after exposure to pulp mill effluents, PCBs, PAHs, and some pesticides. We had recently developed laboratory assays to evaluate the effluents on these responses, but were lacking a protocol for a sediment assay. This paper describes the development of a sediment test capable of demonstrating MFO induction in fish. MFO responses were evident in rainbow trout within 4 days of exposure to contaminated sediments. Further testing showed that fish were responding to chemicals from the sediments, but not from bottom water, and a survey of sediment from thirteen contaminated areas showed that MFO induction more closely paralleled PAH levels in the sediments than the observed PCB concentrations. The sites showing MFO induction were also the sites where sediment toxicity was demonstrated with laboratory bioassays using Daphnia magna and Hyalella azteca. The protocol has been further refined to describe the quantity of sediment required and duration of testing. This test will enable us to study the biochemical effects of exposure to contaminated sediments. The protocol could also be used to prioritize areas of contamination and to evaluate dredging impacts and remediation success.

The ecosystem health of the Toronto Waterfront (Ashbridges Bay), Lake Ontario which receives treated sewage effluent was investigated during 1987 and 1988 by means of a functional and structural battery of tests. The functional tests included in situ size-fractionated primary productivity, Algal Fractionation Bioassays (AFBs), unfiltered and filtered bioassays, and sediment assays with Daphnia magna and Hyalella azteca. The structural evaluation involved the biomonitoring of the components of the ‘microbial loop’, such as bacteria, autotrophic picoplankton, heterotrophic nanoflagellates, and protozoa. The experimental results reveal a diversity of physiological responses to the complex nutrient and contaminant regimes by the indigenous phytoplankton. There was no evidence of the impact of chlorination on the primary productivity of the Bay. The overall productivity was higher during the post-chlorination period than the pre-chlorination phase. The high rates of microplankton + netplankton productivity near the outfall have been attributed to the bioavailability of nutrients which, quite possibly, exert ameliorating effects on metal toxicity. In contrast, the low ultraplankton rates have been interpreted to be due to their well-known sensitivity to contaminants. The Effluent Receiving Water Bioassays (ERWB) with filtered and unfiltered experiments provided interesting insight and appear to be a potentially useful assessment tool. Generally, the unfiltered water compared to the filtered was toxic to the offshore test phytoplankton. This demonstrates a unique ecological adaptation to the prevailing in situ conditions by the Bay community which might be important from the restoration point of view. However, the offshore population was found to be sensitive to the particulate-bound toxicity as indicated by the unfiltered bioassays. Consequently, it is essential to probe the complexity of nutrient-contaminant interactions which ultimately appear to determine the toxicity and the resulting health of the biota. Furthermore, our experiments have shown that the particulate-matter is an important carrier of both nutrients and contaminants in Ashbridges Bay. The sediment bioassays for Station 419 indicated that sediments were toxic during both the pre- and post-chlorination phases. Both solid and liquid phase testing indicated toxicity of sediment to the acute Daphnia test. The Hyalella chronic assay showed good survival during the 4-wk period of the experiment, in contrast to the toxicity observed for phytoplankton and Daphnia. This may be due to large mounts of organic matter available in the Bay. The invertebrate bioassays confirmed the lack of impact of chlorination. Finally, the ‘microbial loop’ seems to be a sensitive, rapid, and an early warning bioindicator of anthropogenic stress. The multi-trophic battery of structural and functional strategy adopted in our laboratory appear to be holistic and effective. The strategy has a considerable potential for developing eco-technology for a badly needed assessment and restoration of ecosystem health of the Great Lakes as well as other perturbed environments in the world.

Pertussis toxin (PT) is a major virulence factor of Bordetella pertussis which exerts a range of effects on the immune system, including the enhancement of IgE, IgA and IgG production, delayed-type hypersensitivity reactions, and the induction of experimental autoimmune diseases. However, the mechanism by which PT mediates adjuvanticity remains to be defined. In this investigation we have shown that PT can potentiate antigen-specific T cell proliferation and the secretion of IFN-γ, IL-2, IL-4 and IL-5 when injected with foreign antigens. A chemically detoxified PT and a genetic mutant with substitutions/deletions in the S-1 and B oligomer components that abrogate enzymatic and binding activity displayed no adjuvant properties. In contrast, a non-toxic S-1 mutant devoid of enzymatic activity but still capable of receptor binding retained its adjuvanticity, augmenting the activation of both T_h1 and T_h2 subpopulations of T cells. In an attempt to address the mechanism of T cell activation, we found that PT stimulated the production of IFN-γ and IL-2 by naive T cells and IL-1 by macrophages. Therefore potentiation of distinct T cell subpopulations may have resulted in part from the positive influence of IFN-γ on the development of T_h1 cells and the co-stimulatory role of IL-1 for T_h2 cells. Furthermore, PT augmented expression of the co-stimulatory molecules B7-1 and B7-2 on macrophages and B cells, and CD28 on T cells, suggesting that the adjuvant effect may also be associated with facilitation of the second signal required for maximal T cell activation. This study demonstrates that the immunopotentiating properties of PT are largely independent of ADP-ribosyltransferase activity, but are dependent on receptor binding activity and appear to involve enhanced activation of T cells.
Keywords:antigen presentation, bacteria, IFN-γ, IL-1, IL-2, IL-4, IL-12, infectious disease, immunomodulator, pertussis vaccine, T cell activation

Peening is a technique commonly used to improve fatigue resistance, but it is not always appreciated that excessive peening may be detrimental to fatigue behaviour. The present work demonstrates this effect in three different alloys: a mild steel, stainless steel, and a commercial copper alloy. The dependence of fatigue behaviour on peening intensity is shown to reach a maximum beyond which high intensity peening reduces fatigue life; at very high intensities the fatigue life can be reduced below the unpeened value. This reduction in fatigue life is shown to coincide with an increase in surface roughness, as measured by the parameter Ra, and the onset of a distinct damage mechanism revealed by scanning electron microscopy. The varying effect of peening intensity in the different materials is related to their tensile, fatigue, and wear properties; a model is advanced to explain the observed behaviour, based on the change from an initiation dominated mechanism to a propagation dominated mechanism as peening intensity is increased. A limited number of results is also presented showing the effect of peening time on fatigue behaviour.

This communication reports the effects of the exotoxin of Bordetella pertussis (pertussis toxin) on hamster brown fat cells. Pertussis toxin significantly increased the lipolytic and respiratory responses to isoproterenol but did not increase the basal rates of either of these processes. In contrast, the stimulation of respiration by the alpha-adrenergic agent phenylephrine was not altered by pertussis toxin. The inhibitory effects of adenosine on stimulated lipolysis, respiration, and adenylate cyclase activity were completely abolished by pertussis toxin, as was the ability of methylxanthines or adenosine deaminase to potentiate isoproterenol stimulation of respiration or lipolysis. These effects of pertussis toxin were associated with an ADP ribosylation of a single membrane protein having a molecular weight of approximately 41. These data demonstrate that pertussis toxin can prevent the inhibitory action of adenosine on brown fat cells and suggest that the effects of the nucleoside on these cells results from inhibition of adenylate cyclase. We further suggest that the enhanced responses to isoproterenol in pertussis-treated adipocytes results from a blockade of the action of endogenous adenosine. In addition to blocking adenosine action, pertussis toxin also abolished the antilipolytic effect of insulin. However, because the antilipolytic effect of insulin was prevented by adenosine deaminase and 3-isobutyl-1-methylxanthine and restored by 2-chloroadenosine, we conclude that insulin action on these cells is dependent on adenosine. Thus pertussis toxin blockade of insulin action appears to be secondary to blockade of adenosine action.

The present study compared the effects of insulin, 2-chloroadenosine, and prostaglandin E2 as inhibitors of respiration in hamster brown adipocytes stimulated with either isoproterenol or phenylephrine. Addition of 2-chloroadenosine or prostaglandin E2 strongly antagonized isoproterenol-stimulated respiration; phenylephrine-stimulated respiration was also partially inhibited by 2-chloroadenosine and prostaglandin E2, but the extent of inhibition caused by these agents was not as great as when isoproterenol was used. Isoproterenol-stimulated respiration was inhibited by insulin, but phenylephrine-stimulated respiration was insensitive to the inhibitory effect of insulin. When brown adipocytes were pretreated with pertussis toxin, isoproterenol-stimulated respiration was enhanced, but phenylephrine-stimulated respiration was not significantly affected. The inhibitory effects of 2-chloroadenosine and prostaglandin E2 on isoproterenol-stimulated respiration were completely blocked by pertussis toxin, indicating that the mode of action of these inhibitory hormones was secondary to inhibition of adenylate cyclase and resultant inhibition of lipolysis. Prostaglandin E2 inhibition of phenylephrine-stimulated respiration was also abolished by pertussis toxin. In contrast, 2-chloroadenosine inhibition of phenylephrine-stimulated respiration persisted in adipocytes treated with pertussis toxin. These data suggest that phenylephrine stimulates respiration through a mechanism that is not altered by pertussis toxin and further that 2-chloroadenosine inhibition of isoproterenol- or phenylephrine-stimulated respiration can be dissociated.

Pertussis toxin (PT) is a major virulence factor of Bordetella pertussis which exerts a range of effects on the immune system, including the enhancement of IgE, IgA and IgG production, delayed-type hypersensitivity reactions, and the induction of experimental autoimmune diseases. However, the mechanism by which PT mediates adjuvanticity remains to be defined. In this investigation we have shown that PT can potentiate antigen-specific T cell proliferation and the secretion of IFN-gamma, IL-2, IL-4 and IL-5 when injected with foreign antigens. A chemically detoxified PT and a genetic mutant with substitutions/deletions in the S-1 and B oligomer components that abrogate enzymatic and binding activity displayed no adjuvant properties. In contrast, a non-toxic S-1 mutant devoid of enzymatic activity but still capable of receptor binding retained its adjuvanticity, augmenting the activation of both Th1 and Th2 subpopulations of T cells. In an attempt to address the mechanism of T cell activation, we found that PT stimulated the production of IFN-gamma and IL-2 by naive T cells and IL-1 by macrophages. Therefore potentiation of distinct T cell subpopulations may have resulted in part from the positive influence of IFN-gamma on the development of Th1 cells and the co-stimulatory role of IL-1 for Th2 cells. Furthermore, PT augmented expression of the co-stimulatory molecules B7-1 and B7-2 on macrophages and B cells, and CD28 on T cells, suggesting that the adjuvant effect may also be associated with facilitation of the second signal required for maximal T cell activation. This study demonstrates that the immunopotentiating properties of PT are largely independent of ADP-ribosyltransferase activity, but are dependent on receptor binding activity and appear to involve enhanced activation of T cells.

Fifty random clinical isolates of Haemophilus parainfluenzae were tested for their susceptibility to 10 antibiotics by a microtiter broth dilution method. Three of the strains tested were resistant to ampicillin, whereas eight were resistant to tetracycline. All strains tested were susceptible to chloramphenicol, kanamycin, gentamicin, cephalothin, and colistin. The ranges of minimal inhibitory concentrations for the three remaining antibiotics were: 0.5 to >/=128 mug of penicillin G per ml, 0.03 to 4 mug of carbenicillin per ml, and 1 to 16 mug of erythromycin per ml. Elevated minimal inhibitory concentrations for penicillin and carbenicillin were noted for the three ampicillin-resistant strains. Tests for beta-lactamase production demonstrated the presence of this enzyme in each of the three ampicillin-resistant strains.

A cDNA clone (HLUG 25) encoding the complete sequence of a human liver UDP-glucuronosyltransferase was isolated from a lambda gt11 human liver cDNA library. The library was screened by hybridization to a partial-length human UDP-glucuronosyltransferase cDNA (pHUDPGT1) identified from a human liver pEX cDNA expression library by using anti-UDP-glucuronosyltransferase antibodies. The authenticity of the cDNA clone was confirmed by hybrid-select translation and extensive sequence homology to rat liver UDP-glucuronosyltransferase cDNAs. The sequence of HLUG 25 cDNA was determined to be 2104 base-pairs long, including a poly(A) tail, and contains a long open reading frame. The possible site of translation initiation of this sequence is discussed with reference to a rat UDP-glucuronosyltransferase cDNA clone (RLUG 38).

Radiation hybrid panels are already available for genome mapping in human and mouse. In this study we have used two model organisms (chicken and zebrafish) to show that hybrid panels that contain a full complement of the donor genome can be generated by fusion to hamster cells. The quality of the resulting hybrids has been assessed using PCR and FISH. We confirmed the utility of our panels by establishing the percentage of donor DNA present in the hybrids. Our hybrid resources will allow inexpensive gene mapping and we expect that this technology can be transferred to many other species. Such successes are providing the basis for a new era of mapping tools, in the form of whole genome radiation hybrid panels, and are opening new possibilities for systematic genome analysis in the animal genetics community.

The precision, accuracy, and other performance characteristics of the MS-2 (Abbott Laboratories, Diagnostic Division, Dallas, Tex.) system for the identification of Enterobacteriaceae were evaluated in a collaborative study involving three clinical laboratories. When identifying 150 unknown, coded organisms, the MS-2 system was 97%, 98%, and 93% accurate, respectively, in three laboratories. The system showed an overall accuracy of 94% when compared with conventional manual tube methods in identifying 1,154 clinical isolates of 26 species of Enterobacteriaceae. Discrepancies between automated and conventional methods were chiefly caused by biochemical variants, especially among Enterobacter species. The MS-2 system was rapid and simple to operate and produced printed results of bacterial identification in 5 h. The cost of disposable components compared favorably with commercial, visually read systems for identifying Enterobacteriaceae.

The MS-2 system (Abbott Diagnostics, Division of Abbott Laboratories, Dallas, Tex.) was evaluated for its efficacy in determining the susceptibilities of both clinical and selected challenge (nonfastidious, facultative, and aerobic) isolates. The MS-2 results were compared with standard Kirby-Bauer disk diffusion and microdilution results by using fresh clinical isolates. For gram-positive isolates other than enterococci, overall agreement between MS-2 and reference results was 93 to 98%. With enterococci, MS-2 agreement with disk diffusion was 68% but with microdilution was 86% (agreement between disk diffusion and microdilution was 73%). The main discrepancies with enterococci were with cephalothin, penicillin, gentamicin, and kanamycin. With clinical gram-negative isolates, the overall agreement was 91 to 93%, with most discrepancies occurring with Enterobacter spp. and beta-lactam antibiotics (MS-2 versus disk diffusion, 84%; MS-2 versus microdilution, 84%; disk diffusion versus microdilution, 87%) and with Serratia spp. and colistin (false-susceptible results). The agreement of MS-2 results with established reference antibiograms of a special collection of challenge strains was 91 to 97% for the gram-positive cocci and 86 to 98% for the gram-negative strains. (With Enterobacter spp., agreement was 86%, but was greater than 90% for all other organism groups.) Of the 98 finite MS-2 minimum inhibitory concentrations (MICs) that could be directly compared with microdilution MICs, 77 (79%) were within +/- 1 well of the geometric mean microdilution MIC. MS-2 analysis time ranged from 2.8 to 6.5 h (mean, 4.2 h). On the basis of these results, we conclude that the MS-2 can be expected to yield rapid and accurate results with most nonfastidious, facultative, and aerobic pathogens.

A pH 4.0 buffered solution of the fluorochrome acridine orange was used to stain samples of 2,704 blood cultures that failed to yield visible evidence of growth after 1 day of incubation. Results obtained by the staining method were compared with those obtained by aerobic and anaerobic subcultures simultaneously performed upon the same cultures. Of the 109 culture-positive blood specimens initially detected by the acridine orange and the subculture methods, 85 (78%) were detected by both acridine orange and subcultures techniques, 14 (12.8%) were detected by subculture alone, and 10 (9.2%) were detected by acridine orange alone. The differences between the subculture and acridine orange methods were not found to be statistically significant (P less than 0.1). The acridine orange method represents a rapid and inexpensive alternative to conventional subculture techniques for the detection of bacteria in blood cultures that fail to yield visible evidence of growth after 1 day of incubation.

A modified auxanographic carbohydrate assimilation procedure for the identification of medically important yeasts is described. This method employs a heavy inoculum of unstarved yeasts, autoclaved yeast assimilation medium, pour plates of shallow depth, and commercially available carbohydrate-impregnated disks. The accuracy of this procedure was established in a comparison with the Wickerham broth method.

Observations were made on respiration, alveolar concentration of CO2, arterial blood pressure and heart rate in barbiturate-anesthetized cats subjected routinely to section of the vagus and carotid sinus nerves and maintained with pure O2 for inhalation. Bolus i.v. injection of angiotensin II (AII), 0.6 to 6.0 micrograms/kg, evoked a prompt shortlasting suppression of breathing, manifested mainly as a reduction in tidal volume susceptible to the development of tachyphylaxis if injections were spaced more closely than 30 min apart. Ablation of the area postrema failed to eliminate the respiratory effect of All. The response also persisted after midbrain transection, spinal cord transection at C8, dorsal rhizotomy of spinal segments C1 to C8 and interruption of cranial nerves V, VII, VIII, IX, X, XI and XII. No influence of All was evident on indirectly evoked tibialis muscle contractions and on pulmonary compliance. A reduction in phrenic nerve impulse traffic coincided with the respiratory response to All. Cranial i.a. injection of All initiated the respiratory effect in its first pass through the brain, before any change occurred in the blood pressure. The degree of All-induced respiratory inhibition was relatively constant at different magnitudes of breathing produced by CO2 inhalation or by electrical stimulation of the respiratory center in the medulla oblongata. It is concluded that All given by bolus intravascular injection causes respiratory inhibition through a direct central action at the final processing step in the CO2-tidal volume controller.

The Gen-Probe PACE 2 assay (Gen-Probe Inc., San Diego, Calif.) was compared with culture for the detection of Neisseria gonorrhoeae in endocervical specimens that were mailed to the laboratory. During mail transport, the specimens were exposed to extremes of hot and cold weather for several days before arriving in the laboratory. Specimens on culture plates deteriorated during transport, as evidenced by many dead gonococcus-like colonies. The manufacturer's recommendation for reporting PACE 2 assay-positive results was modified to create a suspicious category for samples with relative light units near the positive cutoff value. Of a total of 4,869 specimens tested, 30 were positive by both methods and 102 were positive only by the PACE 2 assay. These additional 102 positive specimens were likely to be true positives, as indicated by several lines of indirect evidence, including detailed probe competition analysis, patient history, and the lack of false-positive results in hand-delivered specimens. Although Gen-Probe Inc. indicates that specimens are stable for up to 7 days, N. gonorrhoeae was easily detectable by the PACE 2 assay after 1 month of incubation at room temperature in the PACE 2 transport buffer. We also compared the Gen-Probe PACE 2 assay for Chlamydia trachomatis with culture on endocervical specimens delivered by same-day courier. Of 398 endocervical specimens tested, the PACE 2 assay detected 19 of 20 culture-positive samples. Although the assay failed to detect one culture-positive sample, it was able to detect two very weak culture-suspicious samples. Finally, PACE 2 assays for N. gonorrhoeae and C. trachomatis performed on the same samples indicated that the coinfection rate was 40% for women attending five family planning clinics. We concluded that the Gen-Probe PACE 2 assay system should be considered for use in testing those specimens that are transported to the laboratory through the mail.