Effect of defoliation stress on 2-hydroxy cinnamic acid content at different growth stages in Melilotus albus

Melilotus albus (Medik.) is a pasture legume with potential value in Australian farming systems, especially in salt-affected areas. However, the use of this species has been limited because of concerns over high coumarin concentrations. The aim of this trial was to determine the effect of defoliation on the concentration of 2-hydroxy cinnamic acid, a coumarin precursor, at 3 stages of growth (vegetative, flowering and post-flowering) in 6 accessions. The concentration of 2-hydroxy cinnamic acid was determined by high performance liquid chromatography in leaves of plants grown in a glasshouse. Defoliation stress increased the 2-hydroxy cinnamic acid content in the leaves of all accessions studied by about 8%, from 0.89 to 0.96% of dry matter. The 2-hydroxy cinnamic acid concentrations were not significantly different between vegetative and flowering stages in any of the accessions studied, but showed a significant increase post-flowering for 4 out of the 6 accessions studied. This study indicates that grazing may increase the coumarin or 2-hydroxy cinnamic acid concentration in Melilotus albus, but in screening for suitable accessions to progress to new cultivars, it is not necessary to subject plants to a defoliation stress to rank the accessions for 2-hydroxy cinnamic acid or coumarin concentration.

Microarray comparative genomic hybridisation analysis of intraocular uveal melanomas identifies distinctive imbalances associated with loss of chromosome 3

Defining regions of genomic imbalance can identify genes involved in tumour development. Conventional cytogenetics has identified several nonrandom copy number alterations (CNA) in uveal melanomas (UVM), which include monosomy 3, chromosome 6 abnormalities and gain of 8q. To gain further insight into the CNAs and define the regions involved more precisely we analysed 18 primary UVMs using 1 Mb BAC microarray comparative genomic hybridisation (CGH). Our analysis showed that the most common genomic imbalances were 8q gain (78%), 6p gain (67%) and monosomy 3 (56%). Two distinct CGH profiles could be delineated on the basis of the chromosome 3 status. The most common genetic changes in monosomy 3 tumours, in our study, were gain of 8q11.21-q24.3, 6p25.1-p21.2, 21q21.2-q21.3 and 21q22.13-q22.3 and loss of 1p36.33-p34.3, 1p31.1-p21.2, 6q16.2-q25.3 and 8p23.3-p11.23. In contrast, disomy 3 tumours showed recurrent gains of only 6p25.3-p22.3 and 8q23.2-q24.3. Our approach allowed definition of the smallest overlapping regions of imbalance, which may be important in the development of UVM.

Does human relaxin-2 affect peripheral blood mononuclear cells to increase inflammatory mediators in pathologic bone loss?

This study was designed to test the hypothesis that relaxin stimulates bone resorption by regulating the production of several mediators that stimulate osteoclast formation. The levels of mediators were measured in response to differing relaxin concentrations in supernatants from peripheral blood mononuclear cells (PBMCs), MCF-7 breast cancer cells, and normal human osteoblasts. Although all cell types expressed mRNA for the relaxin receptor (LGR7), only PBMCs responded to relaxin at physiologic levels by increasing tumor necrosis factor-alpha and interleukin-1beta secretion. The findings indicate that PBMCs should be studied in relation to the effect of relaxin on inflammation and bone destruction caused by osteoclasts.

Clinician-led surgical site infection surveillance of orthopaedic procedures: a UK multi-centre pilot study

The UK Department of Health established the Healthcare-associated Infection (HAI) Surveillance Steering Group in 2000 to develop a strategy for implementing a national programme for HAI surveillance in National Health Service trusts. A subgroup of this committee examined the surveillance of surgical site infections following orthopaedic surgery. This group oversaw a pilot scheme that was set up in 12 hospitals around the UK to explore the feasibility of implementing a system of surveillance that engaged clinical staff in its operation, provided a process for continuous data collection and could be maintained as part of routine hospital operation over time. A minimum data set was established by the subgroup, and Centers for Disease Control and Prevention (CDC) definitions of infection were used. By March 2003, the surveillance had been undertaken continuously in 11 sites for one to two years, depending on the date of implementation. Only one hospital had ceased data collection. The information was collected mainly by clinical staff, with support and co-ordination usually provided by infection control teams. Data on more than 5400 procedures were available for analysis for four core procedures: arthroplasty of the hip and knee; hemi-arthroplasty of the hip; and internal fixation of trochanteric fractures of the femur. The data set permitted the calculation of risk-adjusted rates, allowing comparisons between hospitals and within a hospital over time. The methodology enhanced clinical ownership of the surveillance process, re-inforced infection control as the responsibility of all staff, and provided timely feedback and local data analysis. The use of CDC definitions permitted international comparisons of the data.

Virtual reconstruction and morphological analysis of the cranium of an ancient Egyptian mummy

A mummy of an Egyptian priestess dating from the 22nd dynasty (c. 770 BC), completely enclosed in an anthropoid (human shaped) coffin, was scanned on a CT scanner. An accurate reconstruction of the cranium was generated from 115 x 2 mm CT images using AVS/Express on a SGI computer. Linear measurements were obtained from six orthogonal cranial views and used in a morphometric analysis software package (CRANID). The analyses carried out were both linear and nearest neighbour discriminant analysis. The results show that there is a 52.9% probability that the mummy is an Egyptian female, with a 24.5% probability that the mummy is an African female. Thus the technique confirms that the coffin contains an Egyptian female, which is consistent with the inscription on the coffin and the shape of the pelvic bones as revealed by plain X-rays. These results show that this technique has potential for analysing forensic cases where the bones are obscured by soft tissue and clothing. This technique may have an application in virtual autopsies.

The value of testing urine in non-gonococcal urethritis

This audit was conducted to look into the necessity of testing urine threads, in the diagnosis of non-gonococcal urethritis (NGU). In a sample of 280 NGU cases, it was found that in 8.8% of cases there was a risk of the diagnosis being missed, should Gram-stained urethral smears be totally relied on. The study showed that examining urine threads is beneficial in diagnosing NGU, especially, in symptomatic men with negative Gram-stained urethral smears. It should be noted, however, that in the group of patients studied for this audit, urine threads testing did not detect any chlamydia-positive NGU cases.

Potentially toxic metals in ombrotrophic peat along a 400 km English-Scottish transect

Four samples of ombrotrophic peat were collected from each of 10 upland locations in a transect from the southern Pennines to the Highland Boundary Fault, a total distance of ca. 400 km. Bulk compositions and other properties were determined. Total contents of Al and heavy metals (Ni, Cu, Zn, Cd, Pb) were determined following digestion with hydrofluoric acid, and concentrations of metals extractable with dilute nitric acid were also measured. Supernatants obtained from aqueous extractions of the peat samples were analysed for pH, major cations and anions, dissolved organic carbon and dissolved metals, and concentrations of free metal ions (Al(3+), Ni(2+), etc.) were estimated by applying a chemical speciation model. Both total and HNO(3)-extractable metal concentrations varied along the transect, the highest values being found at locations close to industrial and former mining areas. The HNO(3)-extractable soil metal contents of Ni, Cu and Cd were appreciably lower than lowest-observed-effect-concentrations (LOEC) for toxicity towards microorganisms in acid, organic rich soils. However, the contents of Zn at two locations, and of Pb at five locations exceeded LOECs, suggesting that they may be exerting toxic effects in the peats. Soil solution concentrations of free heavy metal ions (Cu(2+), Zn(2+), Cd(2+), Pb(2+)) were substantially lower than LOECs for toxicity towards vascular plants, whereas concentrations of Al(3+) were near to toxic levels at two locations.

Modified spontaneous emission and qubit entanglement from dipole-coupled quantum dots in a photonic crystal nanocavity

The modified spontaneous emission dynamics of two photon-coupled quantum dots in a planar-photonic crystal are theoretically investigated. Based on a photon Green function technique for quantizing the electromagnetic fields in arbitrary surroundings, pronounced vacuum Rabi oscillations and dipole-dipole interactions are self-consistently incorporated and are shown to result in a high degree of quantum-bit entanglement. Quantum dots with different optical dipole moments are also found to yield a very rich display of quantum dynamics and offer several advantages over coupling identical atoms.

Quantum emission dynamics from a single quantum dot in a planar photonic crystal nanocavity

A theoretical quantum-optical study of the modified spontaneous emission dynamics from a single quantum dot in a photonic crystal nanocavity is presented. By use of a photon Green function technique, enhanced single-photon emission and pronounced vacuum Rabi flops are demonstrated, in qualitative agreement with recent experiments.

Impact of combined (18)F-FDG PET/CT in head and neck tumours

To compare the interobserver agreement and degree of confidence in anatomical localisation of lesions using 2-[fluorine-18]fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) and ¹⁸F-FDG PET alone in patients with head and neck tumours. A prospective study of 24 patients (16 male, eight female, median age 59 years) with head and neck tumours was undertaken. ¹⁸F-FDG PET/CT was performed for staging purposes. 2D images were acquired over the head and neck area using a GE Discovery LS™ PET/CT scanner. ¹⁸F-FDG PET images were interpreted by three independent observers. The observers were asked to localise abnormal ¹⁸F-FDG activity to an anatomical territory and score the degree of confidence in localisation on a scale from 1 to 3 (1=exact region unknown; 2=probable; 3=definite). For all ¹⁸F-FDG-avid lesions, standardised uptake values (SUVs) were also calculated. After 3 weeks, the same exercise was carried out using ¹⁸F-FDG PET/CT images, where CT and fused volume data were made available to observers. The degree of interobserver agreement was measured in both instances. A total of six primary lesions with abnormal ¹⁸F-FDG uptake (SUV range 7.2–22) were identified on ¹⁸F-FDG PET alone and on ¹⁸F-FDG PET/CT. In all, 15 nonprimary tumour sites were identified with ¹⁸F-FDG PET only (SUV range 4.5–11.7), while 17 were identified on ¹⁸F-FDG PET/CT. Using ¹⁸F-FDG PET only, correct localisation was documented in three of six primary lesions, while ¹⁸F-FDG PET/CT correctly identified all primary sites. In nonprimary tumour sites, ¹⁸F-FDG PET/CT improved the degree of confidence in anatomical localisation by 51%. Interobserver agreement in assigning primary and nonprimary lesions to anatomical territories was moderate using ¹⁸F-FDG PET alone (kappa coefficients of 0.45 and 0.54, respectively), but almost perfect with ¹⁸F-FDG PET/CT (kappa coefficients of 0.90 and 0.93, respectively). We conclude that ¹⁸F-FDG PET/CT significantly increases interobserver agreement and confidence in disease localisation of ¹⁸F-FDG-avid lesions in patients with head and neck cancers.

Energy-efficient recovery of butanol from model solutions and fermentation broth by adsorption

This article discusses the separation of butanol from aqueous solutions and/or fermentation broth by adsorption. Butanol fermentation is also known as acetone butanol ethanol (ABE) or solvent fermentation. Adsorbents such as silicalite, resins (XAD-2, XAD-4, XAD-7, XAD-8, XAD-16), bone charcoal, activated charcoal, bonopore, and polyvinylpyridine have been studied. Use of silicalite appears to be the more attractive as it can be used to concentrate butanol from dilute solutions (5 to 790-810 g L(-1)) and results in complete desorption of butanol (or ABE). In addition, silicalite can be regenerated by heat treatment. The energy requirement for butanol recovery by adsorption-desorption processes has been calculated to be 1,948 kcal kg(-1) butanol as compared to 5,789 kcal kg(-1) butanol by steam stripping distillation. Other techniques such as gas stripping and pervaporation require 5,220 and 3,295 kcal kg(-1) butanol, respectively.

Targets and elective colorectal cancer: outcome and symptom delay at surgical resection

OBJECTIVE

To determine, for elective patients with colorectal cancer, if associations exist between the length of symptom history at surgical resection and Dukes stage, completeness of the surgical procedure and patient survival.

PATIENTS AND METHODS

A prospective cohort study was undertaken. Five hundred and eighty-two patients with colorectal cancer, admitted for surgical resection after outpatient consultation, divided into four equal quartiles according to length of symptom history (short: n = 131, 0-103 days; medium: n = 136, 104-177 days; long: n = 136, 178-318 days; very long: n = 137, 319-1997 days). The main outcome measures used were the Extent of tumour (Dukes stage) at resection, completeness of resectional surgery (curative vs palliative), patient survival after resection.

RESULTS

For patients undergoing elective surgical resection of colorectal cancer we did not find an association between Dukes stage and duration of patient history (Dukes stage C tumours were seen in 37% (CI: 26.2%-48.0%) of patients with a short symptomatic history as opposed to 34% (CI: 32%-62%) with a very long symptomatic history). Elective curative resection was not associated with a significantly different symptom duration than elective palliative resection (Palliative resections were performed in 24% (CI: 11.7%-36.4%) of patients with a short symptomatic history as opposed to 16% (CI: 2.4%-29.9%) with a very long symptomatic history). The median survival time for the four elective colorectal patient groups defined by length of symptomatic history was not significantly different - (short: n = 131, 4.3 years; medium: n = 136, 5.9 years; long: n = 136, 7.1 years; very long: n = 137, 5.0 years).

CONCLUSION

Tumour extent, completeness of resection and patient outcome after elective colorectal cancer resection was not found to have an association with length of patient history at the time of surgery.

Educational psychology in medical learning: a randomised controlled trial of two aide memoires for the recall of causes of electromechanical dissociation

OBJECTIVES

Although mnemonics are commonly used in medical education there are few data on their effectiveness. A RCT was undertaken to test the hypothesis that a new aide memoire, "EMD-aide", would be superior to the conventional "4Hs+4Ts" mnemonic in facilitating recall of causes of electromechanical dissociation (EMD) among house officers.

METHOD

"EMD-aide", organises causes of EMD by frequency of occurrence and ease of reversibility: four groups organised by shape, colour, position, numbering, clockwise sequence, and use of arrows. Eight hospitals were randomised in a controlled trial and 149 house officers were then recruited by telephone. Baseline ability to recall causes of EMD was recorded at one minute and overall. House officers were then sent a copy of either "4Hs+4Ts" or "EMD-aide" according to randomisation group. Recall ability was retested at one month.

RESULTS

68 of 80 and 51 of 69 house officers completed the study in the "4Hs+4Ts" and "EMD-aide" groups respectively (NS) with similar baseline recall. After intervention median number of recalled causes was greater in the "EMD-aide" group, eight compared with seven at one minute (p = 0.034) and eight compared with seven overall, p = 0.067. Recall of all eight causes was more common in "EMD-aide" group, 54% compared with 35%, p = 0.054, and these house officers spent longer examining their aide memoire, p<0.001.

CONCLUSIONS

"EMD-aide" may be superior to "4Hs+4Ts" in facilitating the recall of the causes of electromechanical dissociation. Educational psychology of medical learning and the use of aide memoires in general are worthy of further study.

Extrinsic optical scattering loss in photonic crystal waveguides: role of fabrication disorder and photon group velocity

Formulas are presented that provide clear physical insight into the phenomenon of extrinsic optical scattering loss in photonic crystal waveguides due to random fabrication imperfections such as surface roughness and disorder. Using a photon Green-function-tensor formalism, we derive explicit expressions for the backscattered and total transmission losses. Detailed calculations for planar photonic crystals yield extrinsic loss values in overall agreement with experimental measurements, including the full dispersion characteristics. We also report that loss in photonic crystal waveguides scales inversely with group velocity, at least, thereby raising serious questions about future low-loss applications based on operating frequencies that approach the photonic band edge.

Anastomotic technique and survival after right hemicolectomy for colorectal cancer

AIM

To compare the long-term outcome of patients after right hemicolectomy for colorectal cancer undergoing ileocolonic reconstruction either by a sutured technique or by side-to-side stapled anastomosis.

METHODS

Single surgeon series from 1992 to 2001 comprising 100 consecutive patients, 59 with hand sutured reconstruction and 41 undergoing TLC 55mm stapled side-to-side anastomosis. Details of gender, patient age, and elective versus emergency presentation, Dukes stage, and curative versus palliative resection were recorded prospectively. In addition, post-operative hospital stay and subsequent survival were determined by prospective protocol follow-up.

RESULTS

Overall 24% of the patients studied presented as emergencies and underwent a palliative procedure. There were no anastomotic leaks in either the stapled or sutured groups. Hospital mortality was also not significantly different--stapled reconstruction, 7%, sutured reconstruction, 10% (p value 0.624). Overall long-term cancer outcome was the same for both anastomotic techniques, both stapled and sutured groups having a median survival of 2.9 years.

CONCLUSIONS

Stapled ileocolonic reconstruction after right hemicolectomy for colonic carcinoma is a safe and reliable surgical technique associated with long-term cancer outcomes comparable with those obtained by the sutured anastomotic technique.

Enhanced single-photon emission from quantum dots in photonic crystal waveguides and nanocavities

A theoretical formalism is presented to investigate enhanced radiative decay of excited dipoles in photonic crystal waveguides and nanocavities with a view to achieving efficient single-photon emission from embedded quantum dots. Surprisingly, large enhancement effects are achievable in both waveguides and nanocavities, and enhanced emission in the waveguide is shown to scale proportionally (inversely) with the photon group index (velocity). Further, a way to include radiative coupling of the quantum dot is shown, and the importance of its inclusion is subsequently demonstrated.

Use of whole genome amplification and comparative genomic hybridisation to detect chromosomal copy number alterations in cell line material and tumour tissue

We have established that whole genome amplification (WGA), in conjunction with genomic DNA array comparative genomic hybridisation (gaCGH) allows for the identification of genome-wide copy number abnormalities (CNAs) in DNA extracted from both cell line and patient material. To determine the fidelity and reproducibility of WGA to detect copy number imbalances using gaCGH, well characterized cell line genomic DNA was analysed. The gaCGH data obtained from non-amplified DNA and amplified DNA for the neuroblastoma cell line NUB7 and a paediatric medulloblastoma patient was almost identical. In addition, laser capture microdissection (LCM) of prostate tumour cells and subsequent WGA allowed for the detection of a number of CNAs that may not have been identified if DNA had been extracted in bulk from heterogeneous tissue. The results presented here demonstrate the use of WGA for generating sufficient DNA for gaCGH analysis without the introduction of significant sequence representation bias. The combination of amplification and gaCGH using DNA extracted from archival patient material has the potential for permitting the studying of DNA from small cancerous or pre-cancerous foci, which may help to identify potential genomic markers for early diagnosis.

Cloning and sequencing of badger (Meles meles) interferon γ and its detection in badger lymphocytes

The European badger (Meles meles) has been identified as a reservoir for Mycobacterium bovis and is implicated in the maintenance and transmission of tuberculosis in cattle. There is a need for a sensitive test of M. bovis infection in badgers and the current serodiagnostic test used for this purpose has low sensitivity. As observed for other species, assay of interferon-gamma (IFNgamma) produced in response to M. bovis antigens is a more sensitive test of tuberculosis. With this objective in sight, we report the first step in the development of an ELISA for badger IFNgamma. The badger IFNgamma gene was cloned and sequenced and used to generate a specific polyclonal antibody to the cytokine. The gene sequence demonstrated regions that were conserved within the IFNgamma genes of other mammals. The badger sequence was most similar to the canine, showing similar structural organisation of the gene and 88% amino acid identity. Rabbits were immunised with DNA encoding badger IFNgamma and the resulting polyclonal antiserum demonstrated specificity for canine IFNgamma by immunoblot of a commercial recombinant canine IFNgamma. The antiserum was used to detect intracellular badger IFNgamma by flow cytometry analysis of badger lymphocytes stimulated with mitogen.

The anaesthetic management of a woman with a 31-week abdominal pregnancy

An 18-year-old primigravida was admitted to hospital complaining of abdominal pain and vomiting. An ultrasound examination suggested the diagnosis of advanced abdominal pregnancy and this was confirmed using magnetic resonance imaging. Two days later she underwent operative delivery of a live fetus. The placenta was left in situ as it was attached to a large number of pelvic structures. Such surgery can result in maternal death due to massive haemorrhage as there is no mechanism to stem blood loss from the placental bed. Death can also occur in the post-partum period from septic complications if the placenta is left in situ. The management of such patients requires personnel and equipment to deal with massive and rapid haemorrhage; aortic cross clamping may be required to control bleeding. In this case, surgery and recovery were uneventful.

Export of dissolved organic carbon from peatlands under elevated carbon dioxide levels

Peatlands represent a vast store of global carbon. Observations of rapidly rising dissolved organic carbon concentrations in rivers draining peatlands have created concerns that those stores are beginning to destabilize. Three main factors have been put forward as potential causal mechanisms, but it appears that two alternatives--warming and increased river discharge--cannot offer satisfactory explanations. Here we show that the third proposed mechanism, namely shifting trends in the proportion of annual rainfall arriving in summer, is similarly unable to account for the trend. Instead we infer that a previously unrecognized mechanism--carbon dioxide mediated stimulation of primary productivity--is responsible. Under elevated carbon dioxide levels, the proportion of dissolved organic carbon derived from recently assimilated carbon dioxide was ten times higher than that of the control cases. Concentrations of dissolved organic carbon appear far more sensitive to environmental drivers that affect net primary productivity than those affecting decomposition alone.