Determination of 3-Chloro-1,2-Propanediol in Foods and Food Ingredients by Gas Chromatography with Mass Spectrometric Detection: Collaborative Study

The results of a collaborative study are reported for the determination of 3-chloro-1,2-propanediol (3-monochloropropane-1,2-diol; 3-MCPD) in a wide range of foods and food ingredients, using gas chromatography with mass spectrometric detection and incorporating the use of a deuterated internal standard. After a pretrial study, 12 laboratories (6 United Kingdom, 1 Switzerland, 1 Japan, 2 United States, 1 The Netherlands, and 1 from the European Commission) were asked to analyze 12 test materials (as known duplicates or split-level samples) by using a prescribed procedure. The test materials consisted of duplicate samples of acid-hydrolyzed vegetable protein (containing 3-MCPD at 0.029 mg/kg), malt extract (0.055 mg/kg), wholemeal bread crumbs (0.030 mg/kg), salami (0.016 mg/kg), cheese alternative (0.043 mg/kg), and soup powder (split levels at 0.045 and 0.041 mg/kg). Repeatability ranged from 0.005 to 0.013 mg/kg and reproducibility, from 0.010 to 0.027 mg/kg, for the samples tested. Precision values were well within statistically predicted levels (HORRAT values of <1 for 5 of the 6 matrixes tested) and within method criteria prepared by a joint working group composed of the United Kingdom Ministry of Agriculture, Fisheries and Food and industry representatives. The study demonstrated the satisfactory validation of the method for quantifying 3-MCPD at levels of ≥0.010 mg/kg. The limit of detection derived from separate in-house studies was estimated to be 0.005 mg/kg. The method was adopted First Action by AOAC INTERNATIONAL.

Properties of laser-produced GaAs plasmas measured from highly resolved X-ray line shapes and ratios

The properties of hot, dense plasmas generated by the irradiation of GaAs targets by the Titan laser at Lawrence Livermore National Laboratory were determined by the analysis of high resolution K shell spectra in the 9 keV to 11 keV range. The laser parameters, such as relatively long pulse duration and large focal spot, were chosen to produce a steady-state plasma with minimal edge gradients, and the time-integrated spectra were compared to non-LTE steady state spectrum simulations using the FLYCHK and NOMAD codes. The bulk plasma streaming velocity was measured from the energy shifts of the Ga He-like transitions and Li-like dielectronic satellites. The electron density and the electron energy distribution, both the thermal and the hot non-thermal components, were determined from the spectral line ratios. After accounting for the spectral line broadening contributions, the plasma turbulent motion was measured from the residual line widths. The ionization balance was determined from the ratios of the He-like through F-like spectral features. The detailed comparison of the experimental Ga spectrum and the spectrum simulated by the FLYCHK code indicates two significant discrepancies, the transition energy of a Li-like dielectronic satellite (designated t) and the calculated intensity of a He-like line (x), that should lead to improvements in the kinetics codes used to simulate the X-ray spectra from highly-charged ions.

Gadolinium-doped iron oxide nanoparticles induced magnetic field hyperthermia combined with radiotherapy increases tumour response by vascular disruption and improved oxygenation

The gadolinium-doped iron oxide nanoparticles (GdIONP) with greater specific power adsorption rate (SAR) than Fe₃O₄ was developed and its potential application in tumour therapy and particle tracking were demonstrated in transgenic adenocarcinoma of the mouse prostate C1 (TRAMP-C1) tumours. The GdIONPs accumulated in tumour region during the treatment could be clearly tracked and quantified by T2-weighted MR imaging. The therapeutic effects of GdIONP-mediated hyperthermia alone or in combination with radiotherapy (RT) were also evaluated. A significant increase in the tumour growth time was observed following the treatment of thermotherapy (TT) only group (2.5 days), radiation therapy only group (4.5 days), and the combined radio-thermotherapy group (10 days). Immunohistochemical staining revealed a reduced hypoxia region with vascular disruption and extensive tumour necrosis following the combined radio-thermotherapy. These results indicate that GdIONP-mediated hyperthermia can improve the efficacy of RT by its dual functions in high temperature (temperature greater than 45 °C)-mediated thermal ablation and mild-temperature hyperthermia (MTH) (temperature between 39 and 42 °C)-mediated reoxygenation.

Clinical Pathways to Ethically Substantive Autonomy

<p>There is no shortage of support for the idea that ethics should be incorporated into the academic and professional curriculum. There is a difference, however, between, on the one hand, teaching professionals about ethics, and, on the other, demanding that they give ethical expression to the range of professional skills they are expected to apply daily in their work. If this expression is not to be perfunctory, ethical judgement must be genuinely integrated into the professional skill set. The mark of integration in this regard is the capacity for autonomous judgement. Ethical autonomy cannot be achieved by a mechanical, rule-bound and circumstance-specific checklist of ethical do’s and don’ts, and it is only partially achieved by a move from mechanistic rules to ‘outcome based’ processes. Rather, professional ethical autonomy presupposes not only a formal understanding of the requirements of an ethical code of conduct, but a genuine engagement with the substantive values and techniques that enable practitioners to interpret and apply principles confidently over a range of circumstances. It is not then, that ethical skill is not valued by the legal profession or legal education, or that the shortfall of ethical skill goes unacknowledged, it is rather that the language of professional ethics struggles to break free from the cautious circularity that is the mark of its formal expression. To require a professional to ‘act in their client’s interests’, or ‘act in accordance with the expectations of the profession’ or act ‘fairly and effectively’ are formal, infinitely ambiguous and entirely safe suggestions; to offer a substantive account of what, specifically, those interests might be, or what expectations we should have, are rather more contentious. Fears of dogma and a narrowing of discretion do, of course, accompany the idea of a search for ethical substance, and caution is to be expected in response to it. Notwithstanding these anxieties, there would appear to be no coherent alternative to the aspiration to substantive autonomy, and this must remain the goal of teaching legal ethics. In light of this, the problem facing educationalists is then perhaps expressed more diplomatically in terms of how ethical skill might be substantively developed, imparted, and integrated into a genuinely comprehensive conception of professional skill.</p><p>Clinical education can go a long way to solving this problem: exposure to the practical tasks of lawyering is the surest and best way of raising consciousness in this regard: ‘Hands-on’ is good - and consciousness-raising is a step in the direction of autonomy, but raw experience and elevated awareness is not enough. We know that our most influential theories of learning tells us that it is in the process of reflection upon problem solving that the practitioner begins to take autonomous control of skill development. In the view of the author, reflection, requires content and direction, and in this paper, with the aid of three models of skill integration inspired by Nigel Duncan’s detailed analysis and video reconstruction of the ethical and technical skill deficiencies brought to light by R v Griffiths, we attempt to specify what might be understood in this regard: Reflective content refers to the discrete interests and values that compete to produce tension in what we will refer to the ‘matrix’ of concerns that feature in all forms of dispute resolution; reflective direction points to an engagement with the resources and techniques that can empower critical and autonomous judgment. In the context of a clinical process broadly structured by the insights of Wenger and by Rest’s model of ethical skill, guided reflection so specified thus serves as an interface between on the one hand, indeterminate ethical form, and, on the other, the substantive ethical wisdom to be found in the repository of values that underpin the very idea of the legal enterprise.</p>

Multivariate methods and artificial neural networks in the assessment of the response of infaunal assemblages to sediment metal contamination and organic enrichment

A 4-year annual sediment survey was conducted in an organically enriched tidal channel to compare the performance of univariate community descriptors, traditional multivariate techniques (TM) and artificial neural networks (AANs), in the assessment of infaunal responses to moderate levels of sediment metal contamination. Both TM approaches and the SOM ANN revealed spatiotemporal patterns of environmental and biological variables, suggesting a causal relationship between them and further highlighting subsets of taxa and sediment variables as potential main drivers of those patterns. Namely, high values of non-natural metals and organic content prompted high abundances of opportunists, while high values of natural metals yielded typical tolerant assemblages of organically enriched areas. The two approaches yielded identical final results but ANNs showed the following advantages over TM: ability to generalise results, powerful visualization tools and the ability to account simultaneously for sediment and faunal variables in the same analysis. Therefore, the SOM ANN, combined with the K-means clustering algorithm, is suggested as a promising tool for the assessment of the ecological quality of estuarine infaunal communities, although further work is needed to ensure the accuracy of the method.

Nekton response to freshwater inputs in a temperate European estuary with regulated riverine inflow

The aim of this 12-year study was to assess the nekton (fish, decapod crustaceans) response to freshwater inputs (rainfall, dam discharges) in a temperate estuary with regulated riverine inflow. Although interannual variability in river discharges to the Guadalquivir estuary has been extremely high since the construction of a dam in 1930, a significant decreasing trend in the dam's discharges has been observed in the last 80 years. During this study, an alternation of wet, standard and dry years occurred in the estuarine area but no significant long-term trend was observed. River discharge, in turn, showed a considerable interannual variability and a significantly decreasing long-term trend. Freshwater inputs had an immediate effect on estuarine salinity and turbidity, and consequently on prey availability (mysids). Although 124 nektonic species were collected, only 47 of them (adding up to 99.7% of total abundance) were regularly present in the estuary: 32 marine migrants, 13 estuarine species and 2 diadromous species. Well-defined temporal changes in species composition and abundance yielded clear seasonal patterns in the estuarine nektonic community. Considerable intermonth and interannual changes were occasionally observed relating to freshwater inputs, mainly in winter/autumn of wet years. Thus, within each two-month period, some significant interannual differences in the nektonic community were also observed, with marine migrants tending to be more abundant in dry years. However, changes in the studied nektonic community did not show long-term trends. In conclusion, natural and human-controlled freshwater inputs currently play a significant role in determining the physicochemical conditions and the biota of the Guadalquivir estuary. However, although freshwater input seemed to transitorily affect the estuarine nekton, either directly (flushing out) or indirectly (through changes in salinity, turbidity and prey availability), a quick reestablishment of the estuarine nekton (strong resilience) was observed following freshwater inputs together with the recovery of environmental conditions within the estuary.

Tailored nanoparticles for tumour therapy

Gd doped iron-oxide nanoparticles were developed for use in tumour therapy via magnetic fluid hyperthermia (MFH). The effect of the Gd3+ dopant on the particle size and magnetic properties was investigated. The final particle composition varied from Gd0.01Fe2.99O4 to Gd0.04Fe2.96O4 as determined by Inductively coupled plasma atomic emission spectroscopy (ICP-AES). TEM image analysis showed the average magnetic core diameters to be 12 nm and 33 nm for the lowest and highest Gd levels respectively. The specific power adsorption rate (SAR) determined with a field strength of 246 Oe and 52 kHz had a maximum of 38Wg(-1) [Fe] for the Gd0.03Fe2.97O4 sample. This value is about 4 times higher than the reported SAR values for Fe3O4. The potential for in vivo tumour therapy was investigated using a mouse model. The mouse models treated with Gd0.02Fe2.98O4 displayed much slower tumour growth after the first treatment cycle, the tumour had increased its mass by 25% after 7 days post treatment compared to a 79% mass increase over the same period for those models treated with standard iron-oxide or saline solution. After a second treatment cycle the mouse treated with Gd0.02Fe2.98O4 showed complete tumour regression with no tumour found for at least 5 days post treatment.

Early hormonal therapy stabilizes hemodynamics during donor procurement

BACKGROUND

Hemodynamic instability has been implicated in the loss of otherwise transplantable organs. We examined the hypothesis that administration of hormonal therapy early during donor management would stabilize hemodynamics and increase the number of organs procured.

METHODS

We retrospectively analyzed 133 consecutive donor records from a single organ procurement organization. Controls (C) received no early hormonal therapy. A steroid group (S) received methylprednisolone only and a combination hormonal therapy group (CH) received thyroxine, methylprednisolone, dextrose, and insulin at the start of donor management (t(0h)). Adrenergic support was adjusted to maintain mean arterial blood pressure (MAP) at > or =60 mm Hg. Doses of adrenergic agents were assessed at t(0h), 4 hours (t(4h)), and just prior to procurement (t(proc)).

RESULTS

Baseline characteristics were similar in all groups. Dosages of adrenergic agents decreased over time in all groups. A significant decrease in adrenergic requirements was seen in the CH group compared with the C group at t(4h) and t(proc). A trend toward decreased adrenergic requirements was noted in S compared with C at t(4h) and t(proc). Slightly more total organs were procured from S and CH compared with C.

CONCLUSIONS

Significantly less adrenergic support was required with early use of CH. A similar (although nonsignificant) reduction was seen with S. The benefit(s) of CH vs corticosteroids alone remains uncertain and requires further study.

Assembly and plasma membrane targeting of recombinant immunoglobulin chains in plants with a murine immunoglobulin transmembrane sequence

The cDNA encoding a full-length murine immunoglobulin gamma 1 heavy chain with its native leader sequence, transmembrane and intracellular domains was introduced into transgenic plants. Transformed plants expressed the recombinant polypeptide, but, in contrast to plants expressing the heavy chain without transmembrane sequence, the protein appeared to be associated with a plant cell membrane. Extraction of the membrane-associated heavy chain required the presence of a non-ionic detergent, and immunofluorescence studies of protoplasts demonstrated surface expression of membrane Ig heavy chain on up to 40% of the cells from a transgenic leaf. In plants expressing both the membrane Ig heavy chain and its partner light chain, functional antibody was also localised to the plant cell membrane and retention of the heavy chain at this site appeared to have no effect on the efficiency of antibody assembly. This approach of localising and accumulating recombinant antibody in cell membranes may have a number of applications, including passive immunisation against plant pathogens.

Initial effects of the toxic waste spill (Aznalcóllar mine accident) on the aquatic macrofauna of the Guadalquivir Estuary

The initial effects of the toxic waste spill in April 1998 at the Aznalcóllar mine (SW Spain) on the nektonic community of the Guadalquivir Estuary were examined at three sampling sites using univariate and multivariate techniques. Since studied communities showed a considerable seasonal trend, only seasonally homogenous periods were compared to analyse effects of the spill: May-August 1997 (before spill) and May-August 1998 (after spill). Results of both techniques (two-way nested ANOVA and ANOSIM tests, P > 0.05) indicated that there was no significant difference between the nektonic community of the estuary before and after the spill (monthly number of species, abundance, biomass and similarity among samples). Conversely, an unusually high density was observed at the outer sampling site immediately after the spill for species typical of more stagnant estuarine habitats. This feature seems to indicate that the fauna in the estuarine area through which the untreated water penetrated into the main course may have been disturbed. Results also suggest that this initial sudden input of fresh water to the estuary could have enhanced the effects of an increased river flow (a drop in the salinity). Nevertheless, longer temporal series of data, especially for permanent estuarine inhabitants, are recommended before conclusions can be drawn on the effects of the toxic waste spill on estuarine communities.

Hospital admission and mortality differentials of asthma between urban and rural populations in New South Wales

It remains unclear whether there are any differentials in hospital admission and mortality rates of asthma between urban and rural populations. An observational study was conducted, based on patient hospital records, to examine the distribution of asthma admissions and mortality in New South Wales. Data on all reported cases of asthma were obtained from New South Wales hospitals between 1989 and 1994. Information on deaths of asthma was collected between 1983 and 1992. The hospital admission rates of asthma varied from 4.8 per 1000 in 1990 to 5.4 per 1000 in 1992 for rural population, and from 3.0 per 1000 in 1991 to 3.4 per 1000 in 1992 for urban population. The hospital admission rates were 51.2-69.1% higher for rural residents than urban dwellers. The mortality rates of asthma ranged from 4.8 per 100,000 in 1983 to 8.0 per 100,000 in 1985 for rural population, and from 3.8 per 100,000 in 1983 to 6.0 per 100,000 in 1989 for urban population. The mortality rates of asthma were 3.62-42.85% higher for rural residents than urban dwellers. These results indicate that the non-age-adjusted hospital admission and mortality rates of asthma were considerably higher in rural populations than in urban populations in New South Wales.

Addressing developmental needs of pregnant adolescents

To appropriately meet the needs of pregnant adolescents, health care providers must evaluate the cognitive and psychosocial development of these clients. Differences in early, middle, and late adolescents who are pregnant are described. The impact of adolescent stages on accomplishing the developmental tasks of pregnancy are discussed. Nursing implications for assessment, communication techniques, teaching strategies, and family interventions are presented. A case study is included.

The nature of calibrators in immunoassays: are they commutable with test samples? Must they be?

Immunoassay systems require calibration protocols that are normally more sophisticated than many analytical techniques in routine clinical use. Calibrators used in such assays may differ significantly from the analyte in clinical specimens. Differences in the properties of calibrators, or reference materials, from those of clinical specimens may include: species origin of the calibrator for an analyte; integrity of the molecular species; matrix of the calibration solution; addition of preservative agents. Owing to the large number of potential differences in the properties of calibrators and those of serum specimens that may affect immunoassay results, the concept of commutability that we originated and first applied to enzyme activity measurements can readily be applied to immunoassay determinations. We specifically examined the properties of calibration materials in nine commercial immunoassay tests for human thyrotropin. Significant non-commutability of materials was demonstrated. The measured results obtained with authentic patient sera differed by a factor of approximately two fold between the techniques exhibiting the lowest and greatest numeric results. Considerably larger intermethod biases were found for calibration materials. Multivariate analysis revealed that the patient sera formed a highly focussed pattern. The calibration materials for one instrument system also focussed in this group. Other calibrators formed three foci indicating similar patterns of commutability within each of the three groups. Clustering was independent of the amount of thyrotropin in the patient specimens, but appeared to be concentration-dependent for at least some of the calibrators. Thus the availability of a common calibration material appears feasible, but not presently available in many commercial products. A processed human serum, a candidate material for use in our proficiency testing program, was projected in the same cluster as authentic patient sera indicating that this material has intermethod properties identical to patient sera (i.e. fully commutable).

Suitability of control materials for determination of alpha-amylase activity

The suitability of control materials for determination of alpha-amylase activity was assessed in comparison with reference groups of authentic human serum specimens containing alpha-amylase of either pancreatic or salivary origin, specimens from patients with no pancreatic pathology, and normal specimens to which porcine pancreatic alpha-amylase was added. After determination of alpha-amylase activity by 11 commonly used techniques (five different principles), the results were processed by both classical (linear representation, regression) and multivariate (correspondence analysis, principal-components analysis) statistical techniques. Specimens containing porcine pancreatic alpha-amylase did not behave like any of the other groups. We conclude that porcine enzyme should not be used for interlaboratory quality-control surveys or intermethod comparison studies. Determination of human salivary and pancreatic alpha-amylase showed intermethod biases similar to those for authentic patients' specimens. Human salivary alpha-amylase, both because of its behavior and its commercial availability, is a satisfactory source for alpha-amylase activity of quality-control specimens. The nature of the matrix (polyvinylpyrrolidone, albumin, delipidated serum, bovine serum, or human serum) little influenced the behavior of the specimens for any of the methods studied.

Suitability of control materials for determination of alpha-amylase activity

The suitability of control materials for determination of alpha-amylase activity was assessed in comparison with reference groups of authentic human serum specimens containing alpha-amylase of either pancreatic or salivary origin, specimens from patients with no pancreatic pathology, and normal specimens to which porcine pancreatic alpha-amylase was added. After determination of alpha-amylase activity by 11 commonly used techniques (five different principles), the results were processed by both classical (linear representation, regression) and multivariate (correspondence analysis, principal-components analysis) statistical techniques. Specimens containing porcine pancreatic alpha-amylase did not behave like any of the other groups. We conclude that porcine enzyme should not be used for interlaboratory quality-control surveys or intermethod comparison studies. Determination of human salivary and pancreatic alpha-amylase showed intermethod biases similar to those for authentic patients' specimens. Human salivary alpha-amylase, both because of its behavior and its commercial availability, is a satisfactory source for alpha-amylase activity of quality-control specimens. The nature of the matrix (polyvinylpyrrolidone, albumin, delipidated serum, bovine serum, or human serum) little influenced the behavior of the specimens for any of the methods studied.