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Biomedical subjects

P Griffin

Publications and source records attributed to P Griffin.

At least 19 recordsLinked to original sources
PubMed2005

Nationwide outbreak of listeriosis due to contaminated meat.

We used molecular subtyping to investigate an outbreak of listeriosis involving residents of 24 US states. We defined a case as infection with Listeria monocytogenes serotype 4b yielding one of several closely related patterns when subtyped by pulsed-field gel electrophoresis. Patients infected with strains yielding different patterns were used as controls. A total of 108 cases were identified with 14 associated deaths and four miscarriages or stillbirths. A case-control study implicated meat frankfurters as the likely source of infection (OR 17.3, 95% CI 2.4-160). The outbreak ended abruptly following a manufacturer-issued recall, and the outbreak strain was later detected in low levels in the recalled product. A second strain was recovered at higher levels but was not associated with human illness. Our findings suggest that L. monocytogenes strains vary widely in virulence and confirm that large outbreaks can occur even when only low levels of contamination are detected in sampled food. Standardized molecular subtyping and coordinated, multi-jurisdiction investigations can greatly facilitate detection and control of listeriosis outbreaks.

Adolescent↗
PubMed2005

Evaluation of environmental burdens associated with sewage treatment processes using life cycle assessment techniques.

Life cycle assessments of a range of wastewater treatment processes have been undertaken. At lower consent standards rotating biological contactors and biological filters exhibit lower environmental burdens for the required functionality than other process options. However, at tighter consents this distinction becomes less clear. Attempts to reduce environmental burdens should focus on operational energy requirements (which dominate burden profiles and, where appropriate, on synthetic materials used for bio-mass growth). However, differences between dry and operational weight, and the consequent size of necessary foundation structures are likely to limit opportunities for reducing overall burden profiles through material substitution. Comparison of processes across population equivalents suggests economies of scale may favour adopting larger scale plant, although there are additional factors yet to be included in this analysis. Furthermore, adopting different waste disposal routes during the demolition phase is unlikely to have a distinct impact on burden profiles.

Biodegradation, Environmental↗
PubMed2005

Factors affecting the longevity of sub-surface horizontal flow systems operating as tertiary treatment for sewage effluent.

Compared with other forms of domestic wastewater treatment, reed beds require very little in the way of operational and maintenance input. This is even more markedly the case with tertiary treatment systems (than with secondary treatment systems) where the necessary maintenance amounts to only a few days/year. Unfortunately, in practice this frequently results in them receiving little or no attention at all. Tertiary treatment reed beds are not a "fit and forget" solution but they are often treated this way because they are very forgiving and abuse-tolerant. After a number of years a few of these tertiary reed beds have deteriorated to an extent whereby they are close to failing to comply with the regulator's requirements. Severn Trent Water Ltd has recognised this situation and has committed a budget for a programme of reed bed maintenance. This work has started with a survey of the condition of their beds and particularly to determine the common problems and hence the maintenance regime required. Five main problems occurred either singly or in combination namely: (a) sludge deposition; (b) above surface flooding (partially caused by (a), (c), and (d)); (c) inlet flow distributor problems/clogging; (d) outlet collector problems/incorrect level; (e) weed infestation.

Biodegradation, Environmental↗
PubMed2005

Impact of operational maintenance on the asset life of storm reed beds.

This paper reviews the operation of storm reed beds to determine whether the current system of operational maintenance is contributing to premature process failures and if not, to identify other factors of importance. Twelve storm reed beds of the horizontal subsurface flow type, at seven locations in the South Warwickshire area of the United Kingdom, were surveyed. Each survey consisted of a site visit, an interview with the operators in charge and an assessment of the treatment performance based on routine monitoring data. Although some sites suffered from varying degrees of sludge accumulation, surface blinding and/or weed growth, all effluent concentrations remained far below the consent levels. Thorough operational maintenance on a reed bed is proven to be important for the asset life. However, there are other factors or features of a reed bed that play a more pivotal role in premature process failure such as the lack of pretreatment and a premature operation of the storm overflow.

Biodegradation, Environmental↗
PubMed2004

Effect of concurrent zidovudine use on the resistance pathway selected by abacavir-containing regimens.

OBJECTIVES: Abacavir (ABC) selects for four mutations (K65R, L74V, Y115F and M184V) in HIV-1 reverse transcriptase (RT), both in vitro and during monotherapy in vivo. The aim of this analysis was to compare the selection of these and other nucleoside reverse transcriptase inhibitor (NRTI)-associated mutations by ABC-containing therapies in the presence and absence of concurrent lamivudine (3TC) and/or zidovudine (ZDV) and to assess the effect of these mutations on phenotypic susceptibility to the NRTIs. DESIGN: This study was a retrospective analysis of the patterns of NRTI-associated mutations selected following virological failure in six multicentre trials conducted during the development of ABC. METHODS: Virological failure was defined as confirmed vRNA above 400 HIV-1 RNA copies/mL. RT genotype and phenotype were determined using standard methods. RESULTS: K65R was selected infrequently by ABC-containing regimens in the absence of ZDV (13 of 127 patients), while L74V/I was selected more frequently (51 of 127 patients). Selection of both K65R and L74V/I was significantly reduced by co-administration of ZDV with ABC (one of 86 and two of 86 patients, respectively). Y115F was uncommon in the absence (seven of 127 patients) or presence (four of 86 patients) of ZDV. M184V was the most frequently selected mutation by ABC alone (24 of 70 patients) and by ABC plus 3TC (48 of 70 patients). Thymidine analogue mutations were associated with ZDV use. The K65R mutation conferred the broadest phenotypic cross-resistance of the mutations studied. CONCLUSIONS: The resistance pathway selected upon virological failure of ABC-containing regimens is significantly altered by concurrent ZDV use, but not by concurrent 3TC use. These data may have important implications for the efficacy of subsequent lines of NRTI therapies.

Anti-HIV Agents↗
PubMed2003

Prevalence of sensitisation to cellulase and xylanase in bakery workers.

AIMS: To assess the prevalence of sensitisation to a range of exogenous fungal enzymes used in bakeries, and determine the relation between sensitisation and work related symptoms. METHODS: Serum samples (n = 135) from a previous cross sectional study investigating the prevalence of respiratory symptoms and sensitisation to dust components, were reanalysed for specific IgE to the mixed enzymes cellulase, hemicellulase, and xylanase. RESULTS: Eight (6%) of sera tested had detectable specific IgE to mixed enzymes (excluding fungal alpha-amylase) and 16 (12%) to fungal alpha-amylase. A significant increase (p = 0.03) in nasal symptoms was found in those workers sensitised to enzymes (including alpha-amylase and the mixed enzymes, but with or without sensitisation to wheat flour) when compared to those sensitised to wheat flour alone. Both groups had significantly greater levels of nasal symptoms in comparison to those with no evidence of sensitisation. CONCLUSIONS: The association between specific IgE to mixed enzymes, and an increased prevalence of nasal symptoms in individuals sensitised to enzymes, highlights the importance of measuring sensitisation to the full range of exogenous enzymes used in the baking industry, as well as to wheat flour.

Cellulase↗
PubMed2003

Ten years experience of treating all flows from combined sewerage systems using package plant and constructed wetland combinations.

Severn Trent Water have been using constructed wetlands since 1991 as part of a flowsheet in which 6 DWF (Dry Weather Flow) is treated by rotating biological contactors (RBCs), and constructed reed beds used to provide both tertiary treatment and stormwater treatment. The company now has over 50 such sites using this flowsheet. Dimensioning and effluent quality achievable is reported and data presented showing the performance of reed beds treating stormwater alone or in admixture with RBC effluent. After 8-10 years of operation the condition of a number of storm reed beds was assessed to determine the remaining asset life. The majority seem likely to achieve at least another five years of operation before further review is needed.

Biodegradation, Environmental↗
PubMed2002

Developing a sustainable energy strategy for a water utility. Part I: A review of the UK legislative framework.

Increasing political effort to improve water quality across the UK and Europe has led to water and sewerage companies investing heavily in high-tech wastewater treatment plants capable of producing high quality effluents. Consequently, amounts of bought-in electricity used for wastewater treatment has and will continue to increase significantly over coming years, while greater provision of enhanced sewage treatment also produces greater volumes of sewage sludge requiring treatment and disposal. Over the same period, tougher controls on the quality of biosolids applied to agricultural land have also been introduced, while there has been an international attempt to reduce the use of fossil-fuel derived power sources because of concerns over global warming. The latter has brought about the introduction of financial instruments, such as the Climate Change Levy, to curb energy use, promote energy efficiency and encourage the development of renewable energy technologies. These factors are set to drive-up the costs of providing adequate sewage treatment services, while at the same time, a tough regulatory line taken to control profits on regional monopolies held by the UK water companies will significantly reduce their revenues over the period 2000-05. The result is that, financially, UK water and sewerage companies face their most challenging period since privatisation in 1989. This paper briefly outlines the current regulations relating to water quality and energy use that will affect water company operations over coming years.

Conservation of Natural Resources↗
PubMed2002

Developing a sustainable energy strategy for a water utility. Part II: A review of potential technologies and approaches.

Environmental legislation is increasing the amounts of bought-in electricity required for sewage treatment, and generating larger volumes of sewage sludge to be treated and disposed of. Concurrently, concerns over global warming and food safety from sewage sludge recycling on agricultural land is augmenting the costs of conventional sewage and sludge treatment technologies and practices. This paper reviews some emerging technologies and practices that may assist in mitigating these problems in the future. In addition, a number of potential renewable energy technologies available to water companies are reviewed. Results suggest that through the take-up of new technologies, current and future water quality standards could be delivered in a more sustainable way. However, this series of papers also highlights that institutional and political conflicts may have inadvertently failed to recognise the wider effects of improving water quality and lessened the financial support necessary for their widespread take-up. It is also suggested that through the use of a Strategic Environmental Assessment (SEA) approach, stakeholders could gain a better understanding of the broader environmental effects of achieving certain water quality standards and develop policy and long-term investment strategies accordingly. However, to fulfill the information requirements of an SEA, an appropriate appraisal tool that considers many of these factors in unison is required, and a possible technique is suggested.

Conservation of Natural Resources↗
PubMed2001

Mass spectrometry screening of combinatorial mixtures, correlation of measured and predicted electrospray ionization spectra.

Methodology was developed to afford rapid characterization of multicomponent mixtures of small organic molecules prepared by split-and-mix combinatorial synthesis. This methodology involved the use of liquid chromatography mass spectrometry (LC/MS) combined with correlation analysis of measured versus predicted electrospray ionization mass spectra. Low-resolution mass spectra of complex mixtures revealed predictable patterns that confirm library products, assisted in identifying chemical synthesis errors, and assessed overall library integrity. In general, equal signal intensities were observed for most combinatorial mixture components, indicating that differences in electrospray ionization efficiency was not a major limitation to this approach. High-throughput data processing programs and informatics tools were used to speed data analysis and to simplify the presentation of the library characterization results. This approach has been used to characterize combinatorial libraries that were synthesized for a variety of drug-discovery programs. Examples are shown for library formats of 1, 40, 66, 280, and 400 component(s)/well. The applicability of this approach to large combinatorial mixtures should allow direct characterization of massive combinatorial libraries.

Journal Article↗
PubMed2001

Anaerobic treatment of domestic wastewater in temperate climates: treatment plant modelling with economic considerations.

Although research suggests that anaerobic treatment of low-strength domestic wastewater is possible in temperate climates, to date, full-scale applications have only been pioneered in hot regions. However, burgeoning environmental legislation in developed countries is giving the impetus to develop anaerobic wastewater treatment systems due to potential economic and environmental benefits they hold over traditional aerobic techniques. In this paper a design rationale for low-temperature, low-strength (COD < 1,000 mgl(-1)), two-phase anaerobic wastewater treatment is developed through empirical modelling of data from published research, and from assumptions arising from a literature review. Model calculations are applied to typical domestic sewage characteristics at two different flow rates, based on population equivalents. Results indicate that soluble COD production in the model hydrolytic tank are similar to those achieved in pilot scale plants in the Netherlands. Model anaerobic reactor sludge characteristics are similar to those achieved in pilot and full-scale anaerobic reactors treating low-strength wastewaters. Indicative cost figures for a two-phase anaerobic treatment plant are given, but are incomplete without an assessment of the cost of post-treatment processes. Anaerobic treatment is likely to become more attractive in the future as new legislation relating to sludge disposal and renewable energy generation are introduced.

Bacteria, Anaerobic↗
PubMed2001

Mechanisms of isocyanate sensitisation. An in vitro approach.

Although there is an abundance of clinical evidence which suggests that the inhalation of isocyanates can induce occupational asthma, the immunological basis for the disease is not understood. We have investigated immune cell responses to isocyanate using the cell line mono-mac-6, by measuring the production of hydrogen peroxide, and the expression of ICAM-1 following challenge with isocyanates and their corresponding amines. We observed an increase in the levels of intracellular peroxide, in addition to an upregulation of ICAM-1 expression (P<0.05), following cell stimulation with isocyanates, which was not apparent following stimulation with amines. From the results of this study we hypothesise that the production of reactive oxygen species (ROS) by monocytic cells at the site of exposure to an isocyanate may have two potential outcomes. The first is that the ROS may contribute to tissue damage at the site of inflammation, and then secondly, it is possible this production of hydrogen peroxide may also induce the upregulation of adhesion markers on monocytic cells, specifically ICAM-1, which may potentiate the infiltration and adhesion of cells at the site of inflammation.

Cyanates↗
PubMed2001

The development of an antibody to trimellitic anhydride.

Acid anhydrides are a group of highly reactive chemicals used widely in the formulation of paints and plastics. Exposure to acid anhydrides causes several occupational lung diseases such as pneumonititis and asthma. Whilst anhydrides, specifically trimellitic anhydride (TMA), have been shown to bind to lung tissue in an animal model, further investigation has been hampered by the lack of a reagent which would enable the identification of primary target proteins for the binding of TMA. Our objective was to develop an antibody to TMA which would enable in vitro studies of TMA interactions with lung epithelial proteins. We developed a monoclonal antibody which binds solely to TMA. We have demonstrated that the antibody can be used to detect TMA bound to different human proteins with little non-specific binding to unconjugated proteins. We then exposed cells of the A549 lung epithelial cell line to TMA in vitro and have shown by western blotting that binding occurs in the 20-35 Kd weight range. We have developed a specific and sensitive reagent to detect TMA bound to proteins. We have used this to show that when TMA is incubated with a lung epithelial cell line, that the TMA binds to proteins with a restricted molecular weight range. These results suggest that the current paradigm for the detection of IgE to small molecular weight reactive chemicals, which presupposes that the chemical binds to serum albumin, may need further investigation.

Animals↗
PubMed2001

Measurement of personal exposure to aerosols of Nephrops norvegicus (scampi) using a monoclonal-based assay.

BACKGROUND: The industrial processing of scampi (Nephrops norvegicus) generates bioaerosols which can cause occupational respiratory disease in exposed individuals. The objective of this study was to develop a monoclonal antibody-based immunoassay to measure scampi proteins collected using standard personal air sampling methods. METHODS: A monoclonal antibody was generated which predominantly bound to a single 97 Kd scampi protein, which we have shown to be a major allergen. This protein was shown by SDS PAGE immunoblotting to be present in various aqueous extracts from wastes produced during scampi processing. A quantitative immunoslotblot method was developed to quantify scampi from air sample filters. RESULTS: We demonstrated the utility of this method by showing a significant difference (P = 0.015) in the level of exposure of two groups of 12 workers processing scampi at a traditional open workstation (GM = 607 ng m(-3)) and at an enclosed workstation (GM = 451 ng m(-3)). CONCLUSION: We conclude that this assay can be used, in conjunction with health surveillance, to monitor exposure and the efficacy of measures to reduce exposure to airborne scampi allergen in an occupational environment.

Aerosols↗
PubMed2001

Personal protective equipment and dermal exposure.

Personal protective equipment (PPE) should only be used as a control measure when other measures are inappropriate or are inadequate by themselves. The person undertaking a risk assessment must exercise his or her judgment to take into account the protection afforded by the PPE. There is, therefore, considerable scope for differences in approach and it would seem sensible to eliminate these differences and ensure consistency, where possible, by reaching agreement on the attenuating effect of PPE. However, there is growing evidence that the levels of protection indicated by laboratory-based tests may not be achieved in real use situations. Studies of workplace protection suggest that the spread of contaminants inside protective clothing, including gloves, is commonplace and significant. Insufficient attention may have been paid to the effect of factors such as temperature differentials on the permeation of chemical agents through protective materials. To investigate this, a test cell was designed and built to measure the breakthrough times and subsequent permeation rate of solvents through glove materials where the temperature inside and outside the glove was representative of those that can occur in the workplace. Two chemical solvents were tested against two different glove materials at three different temperature conditions. The differences between the breakthrough times and permeation rates were measured and compared to manufacturer's test data. The practical implications are considered for risk of health and safety to the wearer.

Gloves, Protective↗
PubMed2001

A specialized crisis response site as a core element of police-based diversion programs.

Transporting an individual in psychiatric crisis to an emergency department is often frustrating for both law enforcement and mental health professionals. To facilitate collaboration between police and mental heath professionals in crisis cases, some communities have developed prebooking diversion programs that rely on specialized crisis response sites where police can drop off individuals in psychiatric crisis and return to their regular patrol duties. These programs identify detainees with mental disorders and work with diversion staff, community-based providers, and the courts to produce a mental health disposition in lieu of jail. This paper describes three of the diversion programs participating in the Substance Abuse and Mental Health Services Administration jail diversion knowledge development application initiative that demonstrate the importance of specialized crisis response sites. The three programs are in Memphis, Tennessee; Montgomery County, Pennsylvania; and Multnomah County, Oregon. The authors describe important principles in the operation of these programs: being a highly visible, single point of entry; having a no-refusal policy and streamlined intake for police cases; establishing legal foundations to detain certain individuals; ensuring innovative, intensive cross-training; and linking clients to community services.

Antisocial Personality Disorder↗