A rapid and accurate method for the determination of plutonium in food using magnetic sector ICP-MS with an ultra-sonic nebuliser and ion chromatography

In the event of a nuclear incident it is essential that analytical information on the distribution and level of contamination is available. An ICP-MS method is described which can provide data on plutonium contamination in food within 3 h of sample receipt without compromising detection limits or accuracy relative to traditional counting methods. The method can also provide simultaneous determinations of americium and neptunium. Samples were prepared by HNO3 closed-vessel microwave digestion, evaporated to dryness and diluted into a mobile phase comprising 1.5 M HNO3 and 0.1 mM 2,6-pyridinedicarboxylic acid. A commercially available polystyrene-divinylbenzene ion chromatography column provides on-line separation of 239Pu and 238U reducing the impact of the 238U1H interference. Oxidation of the sample using H2O2 ensures all Pu is in the Pu(+4) state. The oxidation also displaces Np away from the solvent front by changing the oxidation state from Np(+3) to Np(+4) and produces the insoluble Am(+4) ion. Simultaneous Pu, Am and Np analyses therefore require omission of the oxidation stage and some loss of Pu data quality. Analyses were performed using a magnetic sector ICP-MS (Finnigan MAT Element). The sample is introduced to the plasma via an ultrasonic nebuliser-desolvation unit (Cetac USN 6000AT+). This combination achieves an instrumental sensitivity of 238U > 2 x 10(7) cps/ppb and removes hydrogen from the sample gas, which also inhibits the formation of 238U1H. The net effect of the improved sample introduction conditions is to achieve detection levels for Pu of 0.020 pg g(-1) (4.6 x 10(-2) Bq kg(-1)) which is significantly below 1/10th of the most stringent EU (European Union) legislation, currently 0.436 pg g(-1) (1 Bq kg(-1)) set for baby food. The new method was evaluated with a range of biological samples ranging from cabbage to milk and meat. Recovery of Pu agrees with published values (100% +/- 20%).

Pancreatic resection for metastatic melanoma

BACKGROUND

The pancreas is an occasional site of metastases from melanoma. It may be the only location of metastatic disease, but more often the melanoma metastasis to other organs as well. Treatment options are somewhat limited, and the role of operative treatment is poorly defined.

CASE OUTLINES

Two patients presenting with abdominal pain were found to have pancreatic lesions. A 45-year-old woman had a pylorus-preserving pancreatoduodenectomy for a mass in the head of pancreas; concurrent liver nodules were treated by segmental liver resection. A 55-year-old man had a total pancreatectomy for multiple pancreatic tumours. Both patients gave a history of ocular melanoma, diagnosed >10 years previously. They had no evidence of malignancy elsewhere. Histology of resected specimens confirmed metastatic melanoma with features consistent with an ocular primary. All resection margins were clear of malignancy, and no lymph node metastases were detected. At 6 months follow-up there were no signs of tumour recurrence.

DISCUSSION

Complete surgical resection offers potential cure in selected patients with metastatic melanoma involving the pancreas, when there is no evidence of widespread disease.

Mechanisms of magnesium-stimulated adhesion of osteoblastic cells to commonly used orthopaedic implants

Poor cell adhesion to orthopaedic and dental implants may result in implant failure. Cellular adhesion to biomaterial surfaces primarily is mediated by integrins, which act as signal transduction and adhesion proteins. Because integrin function depends on divalent cations, we investigated the effect of magnesium ions modified bioceramic substrata (Al(2)O(3)-Mg(2+)) on human bone-derived cell (HBDC) adhesion, integrin expression, and activation of intracellular signalling molecules. Immunohistochemistry, flow cytometry, cell adhesion, cell adhesion blocking, and Western blotting assays were used. Our findings demonstrated that adhesion of HBDC to Al(2)O(3)-Mg(2+) was increased compared to on the Mg(2+)-free Al(2)O(3). Furthermore, HBDC adhesion decreased significantly when the fibronectin receptor alpha5beta1- and beta1-integrins were blocked by functional blocking antibodies. HBDC grown on the Mg(2+)-modified bioceramic expressed significantly enhanced levels of beta1-, alpha5beta1-, and alpha3beta1-integrins receptors compared to those grown on the native unmodified Al(2)O(3). Tyrosine phosphorylation of intracellular integrin-dependent signalling proteins as well as the expression of key signalling protein Shc isoforms (p46, p52, p66), focal adhesion kinase, and extracellular matrix protein collagen type I were significantly enhanced when HBDC were grown on Al(2)O(3)-Mg(2+) compared to the native Al(2)O(3). We conclude that cell adhesion to biomaterial surfaces is probably mediated by alpha5beta1- and beta1-integrin. Cation-promoted cell adhesion depends on 5beta1- and beta1-integrins associated signal transduction pathways involving the key signalling protein Shc and results also in enhanced gene expression of extracellular matrix proteins. Therefore, Mg(2+) supplementation of bioceramic substrata may be a promising way to improve integration of implants in orthopaedic and dental surgery.

Larvae therapy and venous leg ulcers: reducing the 'yuk factor'

When a podiatrist modified a nylon maggot therapy containment bag used to dress a wound, debridement was slower but the maggots could be more easily observed and were easier to remove. It is also more user friendly for patients and practitioners.

The awakening cortisol response: no evidence for an influence of body posture

It has recently been reported that the orthostatic challenge associated with postural change from sitting to an upright position is stimulatory to the hypothalamic-pituitary-adrenal axis as evidenced by increased salivary free cortisol. This stimulatory influence is potentially a confound for the many psychoneuroendocrine studies for which salivary free cortisol is the main dependent variable. This particularly relates to laboratory psychosocial stress procedures in which subjects are invited to stand in order to deliver public speech and the studies which have explored the cortisol response to awakening in which postural shift has not been controlled for. We therefore examined, in a balanced cross over design whether the awakening cortisol response was influenced by standing, shortly after awakening or remaining supine during the response study period. In addition and in the same subjects we measured the cardiovascular response and saliva cortisol response to the orthostatic challenge of shifting from a supine to a standing position later in the diurnal cortisol cycle. The expected cortisol response to awakening was demonstrated but there was no evidence that the postural shift, supine to standing, confounded the response. This same postural shift later in the day induced the expected increase in heart rate but cortisol simply followed the circadian decline. Under the conditions of the present study we found no evidence that the postural shift supine to standing could induce a cortisol secretory episode such as to contribute towards the awakening response.

Ultrasound measures of bone and the diurnal free cortisol cycle: a positive association with the awakening cortisol response in healthy premenopausal women

In this study we examined the relationship between characteristics of the diurnal pattern of salivary free cortisol concentration and ultrasound (US) measures of bone in premenopausal women. Subjects were 36 healthy, eumenorrhoeic, nonsmoking women mean age (SE) 30.9 (1.3) years. Saliva samples were collected on awakening and 10, 20, 30, 120, 240, and 600 minutes thereafter. Calcaneal broadband ultrasonic attenuation (BUA) and speed of sound (SOS) were determined. Mean (SE) salivary cortisol concentration was 4.7 (0.5) nmol/l on awakening, peaked at 8.6 (0.9) nmol/l 30 min later, and declined to a trough of 2.3 (0.2) nmol/l 600 min after awakening. BUA and SOS were significantly associated with cortisol 0 and 30 min after awakening (r = 0.40 and 0.40 for BUA and 0.33 and 0.37 for SOS, respectively, with body mass included as covariate). Cortisol levels 240 and 600 min after awakening were not significantly associated with bone variables. Women above the median for peak (30 min after awakening) cortisol had significantly higher BUA and SOS than those below the median [BUA 51.8 (1.0) vs 47.4 (1.5) dB/MHz, P = 0.017; SOS 1554.0 (2.5) vs 1546.4 (1.5) m/sec, P = 0.008]. A high peak in cortisol following awakening was associated with higher US measures of bone in healthy premenopausal women. This finding suggests the possibility that diurnal variation in cortisol may have a role in bone metabolism.

Local lymph node assay - validation, conduct and use in practice

The validation of alternative methods is a relatively new activity in toxicology. The local lymph node assay (LLNA), a novel method for the identification of chemicals that have the potential to cause skin sensitization, was the first test to pass through the formal regulatory validation process established in the USA under the auspices of ICCVAM, the Interagency Coordinating Committee on the Validation of Alternative Methods. ICCVAM approved the LLNA as an alternative to guinea pig tests for the identification of skin sensitisation hazards. In this report, we explore the nine recommendations made by ICCVAM and discuss their interpretation in relation to the new OECD Guideline 429, which describes the LLNA. In particular, the value and limitations of the use of statistical evaluation of data and of the inclusion of routine positive controls is examined. It is concluded that the OECD Guideline as currently written embodies the necessary flexibility to permit conduct of the LLNA in a manner necessary to meet the varying needs of regulatory agencies and toxicologists around the world.

In-vitro activity of S. lavandulaefolia (Spanish sage) relevant to treatment of Alzheimer's disease

Salvia lavandulaefolia Vahl. (Spanish sage) essential oil and individual monoterpenoid constituents have been shown to inhibit the enzyme acetylcholinesterase in-vitro and in-vivo. This activity is relevant to the treatment of Alzheimer's disease, since anticholinesterase drugs are currently the only drugs available to treat Alzheimer's disease. Other activities relevant to Alzheimer's disease include antioxidant, anti-inflammatory and estrogenic effects. Results of in-vitro tests for these activities are reported here for S. lavandulaefolia extracts, the essential oil and its major constituents. Antioxidant activity (inhibition of bovine brain liposome peroxidation) was found in the EtOH extract of the dried herb (5 mg mL(-1)) and the monoterpenoids (0.1 M) alpha- and beta-pinene and 1,8-cineole. Thujone and geraniol had lower antioxidant effects, while camphor had no antioxidant effects. Possible anti-inflammatory activity (eicosanoid inhibition in rat leucocytes) was found in the EtOH extract (50 microg mL(-1)) and was shown by the monoterpenoids alpha-pinene and geraniol (0.2 mM), but not 1,8-cineole, thujone or camphor. Possible estrogenic activity (via induction of beta-galactosidase activity in yeast cells) was found in the essential oil (0.01 mg mL(-1)) and the monoterpenoid geraniol (0.1-2 mM). 1,8-Cineole, alpha- and beta-pinene and thujone did not exhibit estrogenic activity in this analysis. These results demonstrate that S. lavandulaefolia, its essential oil and some chemical constituents have properties relevant to the treatment of Alzheimer's disease and provide further data supporting the value of carrying out clinical studies in patients with Alzheimer's disease using this plant species.

High resolution ID-ICP-MS certification of an estuary water reference material (LGC 6016) and analysis of matrix induced polyatomic interferences

Reliable trace metal analysis of environmental samples is dependent upon the availability of high accuracy, matrix reference standards. Here, we present Cd, Cu, Ni, Pb and Zn isotope dilution determination for an estuary water certified reference material (LGC 6016). This work highlights the need for high-accuracy techniques in the development of trace element CRMs rather than conventional inter-laboratory trials. Certification of the estuary water LGC6016 was initially determined from a consensus mean from 14 laboratories but this was found to be unsatisfactory due to the large discrepancies in the reported concentrations. The material was re-analysed using isotope dilution ICP-MS techniques. Pb and Cd were determined using a conventional quadrupole ICP-MS (Elan 5000). Cu, Zn and Ni were determined using a magnetic sector ICP-MS (Finnigan Element), which allowed significant polyatomic interferences to be overcome. Using the magnetic sector instrument, precise mass calibration to within 0.02 amu permitted identification of the interferences. Most interferences derived from the sample matrix. For example, the high Na content causes interferences on 63Cu, due to the formation of 40Ar23Na and 23Na2 16O1H, which in a conventional quadrupole instrument would relate to an erroneous increase in signal intensity by up to 20%. For each analyte a combined uncertainty calculation was performed following the Eurachem/GTAC and ISO guideline. For each element a combined uncertainty of 2-3% was found, which represents a 10-fold improvement compared to certification by inter-laboratory comparison. Analysis of the combined uncertainty budget indicates that the majority of systematic uncertainty derives from the instrumental isotope ratio measurements.

End-of-life decisions: physicians as advocates for advance directives

Physicians have a unique role in supporting patients and families throughout their lives; their expertise is called on not only in life, but also at its end. This study was designed to determine the effect of an individual's age, gender, and attachment to the decision maker with regard to life support choices. A total of 151 subjects completed the researcher-developed instrument. Results suggest that the age of patients is significantly related to the life support options chosen. Specifically, the greater the age of the patient, the more likely a less vigorous life support alternative was chosen. Gender and attachment had no effect on the level of care chosen. Study participants also identified reasons for selecting a particular life support choice for each case. The most common reasons given for a close relative centered around quality-of-life issues. In situations involving a nonrelative, life support decisions were likely to be made using the principle of best interest. The primary care physician has a unique opportunity to initiate discussions about life support issues with patients and families. These decisions must be framed in the context of individual patient expectations and desires throughout the life span.

Recognition of E-cadherin by integrin alpha(E)beta(7): requirement for cadherin dimerization and implications for cadherin and integrin function

We have investigated the importance of dimerization of E-cadherin in the heterophilic adhesive interaction between E-cadherin and integrin alpha(E)beta(7). Dimerization of cadherin molecules in parallel alignment is known to be essential for homophilic adhesion and has been attributed to Ca(2+)-dependent interactions in the domain 1-2 junction or to cross-intercalation of Trp2 from one molecule to the other. We have disrupted either or both of these proposed mechanisms by point mutations in E-cadherin-Fc and have tested the modified proteins for alpha(E)beta(7)-mediated cell adhesion. Prevention of Trp2 intercalation had no adverse effect on integrin-mediated adhesion, whereas disruption of Ca(2+) binding permitted adhesion but with reduced efficiency. Both modifications in combination abolished recognition by alpha(E)beta(7). In EGTA, alpha(E)beta(7) adhered to wild type E-cadherin but not to the Trp2 deletion mutant. Independent evidence that the mutations prevented either or both mechanisms for dimerization is presented. The data show that dimerization is required for recognition by alpha(E)beta(7) and that it can take place by either of two mechanisms. Implications for the roles of the alpha(E) and beta(7) integrin subunits in ligand binding and for Trp2 and Ca(2+) in the assembly of cadherin complexes are discussed.

Association between time of awakening and diurnal cortisol secretory activity

A 12-hour diurnal profile of salivary free cortisol was measured in healthy adults (n=40) on two consecutive days. Samples were collected at timed intervals synchronised to awakening. The mean profile is characterised by a marked increase in cortisol concentration following awakening, peaking after about 30 min, and a subsequent decline over the remainder of the day. Thus two components of the diurnal cycle were examined: a) the first 45 min post-awakening (the awakening cortisol response) and b) the underlying 12 h profile from immediately until 12 h post awakening (but without the awakening response). Both of these components were analysed in two ways such as to provide an indication of overall cortisol concentration and the degree of change in cortisol concentration, i.e. the rise for the awakening response and the diurnal decline. Both components of the cortisol diurnal profile were negatively correlated with awakening time. Thus, those subjects who awoke earliest had higher levels of cortisol over the 45 min following awakening as well as throughout the rest of the day. They also displayed a more marked diurnal decline to be convergent with late awakeners at the end of diurnal measurement, 12 h following awakening. Hence the diurnal cortisol cycle, which is synchronised to awakening, is significantly related to awakening time. These findings support the notion of a close association between suprachiasmatic nucleus (SCN) control of both awakening and cortisol secretory activity.

Ultrafast Source-to-Surface Movement of Melt at Island Arcs from 226 Ra- 230 Th Systematics

Island arc lavas have radium-226 excesses that extend to higher values than those observed in mid-ocean ridge or ocean island basalts. The initial ratio of radium-226 to thorium-230 is largest in the most primitive lavas, which also have the highest barium/thorium ratios, and decreases with increasing magmatic differentiation. Therefore, the radium-226 excesses appear to have been introduced into the base of the mantle melting column by fluids released from the subducting plate. Preservation of this signal requires transport to the surface arguably in only a few hundreds of years and directly constrains the average melt velocity to the order of 1000 meters per year. Thus, melt segregation and channel formation can occur rapidly in the mantle.

Exploration of the awakening cortisol response in relation to diurnal cortisol secretory activity

Adrenocortical activity can be assessed by measurement of free cortisol in saliva. Cortisol status has important health implications in both physical and psychological terms. Assessment of cortisol status is complicated by the marked diurnal cortisol cycle. This cycle is characterised by an increase in secretory activity following awakening to achieve the morning acrophase. Thereafter it falls with a declining trend over the remainder of the day. For between subject studies the timing of sampling in relation to this cycle is an important consideration. We report a comprehensive study of the diurnal free cortisol cycle designed to analyse its components and to investigate their reliability and inter-relatedness. We instructed 42 healthy volunteers to collect saliva samples at home on two consecutive days. On each day the first sample was collected immediately upon awakening, followed by a further three samples at 15-minute intervals which collectively comprised the "awakening samples". A further four sample's were collected through the day at 3-hour intervals, all synchronized to awakening time. The cortisol response to awakening was calculated in two ways. Overall cortisol production in the first 45 minutes after awakening was calculated as area under the cortisol curve with reference to zero (AUC). The dynamic of the cortisol response to awakening was calculated as area under the cortisol response curve (AURC) with reference to the first awakening sample. In addition the underlying cortisol secretory activity was assessed based upon the diurnal three-hourly samples. All three parameters of adrenocortical activity showed reasonable stability across the two sampling days indicating all were reliable indexes of trait characteristic. AUC was representative of underlying diurnal activity but AURC was not. Measurement at any time point, 3, 6, 9 or 12 hours post-awakening was representative of the underlying 12-hour diurnal activity.

An investigation of three-dimensional scanning of human body surfaces and its use in the design and manufacture of prostheses

The capture of highly accurate data describing the complex surfaces of the human body may prove extremely useful in many medical situations. The data provide a method of measuring and recording changes to the surface of a patient's soft tissue. The data may be applied to computer-controlled manufacturing techniques, such as rapid prototyping (RP). This enables accurate physical replicas of the patient topography to be produced. Such models may be used as an aid in the design and manufacture of prostheses. This paper describes an investigation aimed at identifying problems that may be encountered when scanning patients and describes the application of the resulting data in the design and manufacture of facial prostheses. The results of the experiment are presented together with a discussion of the accuracy and potential advantages afforded by this approach.

Therapeutic embolization of an internal mammary artery damaged by placement of a central venous catheter

We describe the embolization of a left internal mammary artery damaged by left internal jugular venous catheterization. Because potentially serious complications can occur with a blind approach for central venous catheterization, portable ultrasound machines should be used more often to ensure correct placement of the catheter.

Training primary care physicians to give limited manual therapy for low back pain: patient outcomes

STUDY DESIGN

Randomized controlled study of standard manual therapy given by 31 generalist physicians to 295 patients, in primary care practice.

OBJECTIVES

To determine whether training primary care physicians in techniques of limited manual therapy would result in improved outcomes for their patients with acute low back pain.

SUMMARY OF BACKGROUND DATA

Controversy continues regarding the benefit of spinal manual therapy and the role of highly trained manual therapists in the care of low back pain. Continuing medical education in manual therapy is frequently offered to generalist physicians, but nothing is known of the value and effectiveness of this training.

METHODS

Thirty-one primary care physicians were trained to provide optimal low back care (enhanced care) and a sequence of eight standard manual therapy techniques. Two hundred ninety-five patients were randomized into two treatment groups: enhanced care alone and enhanced care with manual therapy. Main outcome measures included the Roland-Morris functional disability scale measured over time and patient-reported time to functional recovery, time to complete recovery, and satisfaction with care.

RESULTS

No differences were found in Roland-Morris scores over time, mean functional days to recovery, days absent from work, or patient satisfaction. More patients receiving manual therapy (21; 14%) had completely recovered after the first visit compared with the control group (8; 6%; P = 0.01). Patients who received more intense manual therapy (four or more maneuvers) had a more rapid return to functional recovery (7.8 days) compared with those who received less intense manual therapy (11.1 days; P = 0.02).

CONCLUSION

Limited training in manual therapy techniques offers very modest benefit compared with high-quality (enhanced) care for acute low back pain. Outcomes may have been modified by failure of some participant physicians to undertake the required sequence of maneuvers. Intensity of manual therapy may be a factor in improving patient outcomes and needs further study.

Volatiles as an indicator of fungal activity and differentiation between species, and the potential use of electronic nose technology for early detection of grain spoilage

There is significant interest in methods for the early detection of quality changes in cereal grains. The development of electronic nose technology in recent years has stimulated interest in the use of characteristic volatiles and odours as a rapid, early indication of deterioration in grain quality. This review details the current status of this area of research. The range of volatiles produced by spoilage fungi in vitro and on grain are described, and the key volatile groups indicative of spoilage are identified. The relationship between current grain quality descriptors and the general classes of off-odours as defined in the literature, e.g. sour, musty, are not very accurate and the possible correlation between these for wheat, maize and other cereals, and volatiles are detailed. Examples of differentiation of spoilage moulds and between grain types using an electronic nose instrument are described. The potential for rapid and remote grain classification and future prospects for the use of such technology as a major descriptor of quality are discussed.

Training in back care to improve outcome and patient satisfaction. Teaching old docs new tricks

BACKGROUND

We examined clinical outcomes and patient perceptions of back care given by physicians before and after an intensive course of training in back care and limited manual therapy techniques.

METHODS

From a prospective observational cohort study of low back pain involving 208 physicians (115 primary care) and their patients and a subsequent clinical trial of treatment of low back pain given by 31 physicians specially trained in manual therapy and enhanced back care, outcome data from the patients of 13 physicians participating in both studies were compared. In the observational study, the 13 physicians cared for 120 patients. In the manual therapy trial (191 patients) a control group of 94 patients received enhanced back care and an intervention group of 97 patients received enhanced back care plus manual therapy. Pearson's chi-square comparisons and linear and Cox proportional hazard modeling were used to examine effects of variables and recovery time.

RESULTS

Characteristics of the 13 physicians' patients in the cohort group and the manual therapy trial showed some differences in income, workers' compensation, previous employment, and baseline dysfunction. Both control and intervention patients in the manual therapy trial showed more rapid improvement in functional status over time and greater satisfaction with their care than those in the previous cohort study. However, there was no difference between the studies in patient-reported time to return to performing usual daily activities.

CONCLUSIONS

A structured clinical approach to low back care may bring modestly improved clinical outcomes and patient satisfaction.