A chromosomal event resulting in possession and expression of multiple HLA-B and Cw genes in a renal patient

Routine HLA typing of a renal patient for purposes of registration for transplantation revealed an unusual human leucocyte antigen (HLA)-B and Cw genotype, with three specificities detected. Results were confirmed in a second sample, and in a second laboratory. The possibility of these results reflecting a chimaeric state was rejected following short tandem repeat (STR) analysis. Although cytogenetic analysis has failed to detect a chromosomal abnormality, these findings support the view that the aberrant expression of HLA in this patient resulted from an unequal crossover event, occurring during meiosis in a previous generation.

Flexible, actin-based ridges colocalise with the beta1 integrin on the surface of melanoma cells

Using a combination of laser-scanning confocal microscopy and atomic force microscopy, we have identified flexible, actin-based structures on the surface of cells derived from the vertical growth phase of melanoma progression. These flexible structures, lacking on the surface of mature melanocytes, were observed on the surface of all four melanoma cell lines tested. Further investigation revealed that the β1 integrin colocalises with these actin-based ridges on the cell surface, whereas β1 integrin distribution in melanocytes did not correlate with actin-based structures. Fibronectin staining on the surface of melanoma cells was partially codistributed with the ridges. The combination of structural information derived from atomic force microscopy images and fluorescent imaging of the distribution of labelled proteins involved in invasion and metastasis has allowed us to identify a common feature that may be involved in disease progression, at the surface of vertical growth phase melanoma cells, despite the known variation in genetic composition of melanoma.

Upper limb disability in HAVS cases—how does it relate to the neurosensory or vascular elements of HAVS?

AIMS

Hand-arm vibration syndrome (HAVS) consists of vascular, neurosensory and musculoskeletal components, characterized by symptoms that include Raynaud's phenomenon, tingling and numbness in the hands. However, there has been little published data on the effects of HAVS on the capability to carry out normal daily tasks. We have investigated the application of the widely-used disability, arm, shoulder and hand (DASH) disability questionnaire that reflects functionality problems in the upper extremities, as well as symptoms, in a HAVS cohort.

METHODS

The cohort consisted of 118 males who, as a part of their health surveillance, had been referred for further assessment and Stockholm workshop staging. This process involved medical interview, physical examination and quantitative tests covering neurosensory function, manual dexterity and handgrip strength.

RESULTS

The relationship between DASH outcome metric and a combination of quantitative tests reflecting a range of abnormalities found in HAVS, supports the validity of this questionnaire in HAVS studies. The data suggest that HAVS cases have a greater level of upper extremity disability compared with a general population. The study confirms that disability in HAVS is very largely related to sensorineural Stockholm workshop staging, rather than vascular staging. Any influence of vibration-induced Raynaud's phenomenon on upper extremity disability is related to the frequency of blanching attacks rather than their extent across the digits.

CONCLUSION

This study strengthens the importance of identifying and preventing the exacerbation of the neurosenory component of HAVS, that unlike the blanching attacks of the vascular component does not have such an obvious pathognomic signal.

Cocaine Exposure Is Associated With Subtle Compromises of Infants' and Mothers' Social-Emotional Behavior and Dyadic Features of Their Interaction in the Face-to-Face Still-Face Paradigm

Prenatal cocaine and opiate exposure are thought to subtly compromise social and emotional development. The authors observed a large sample of 236 cocaine-exposed and 459 nonexposed infants (49 were opiate exposed and 646 nonexposed) with their mothers in the face-to-face still-face paradigm. Infant and maternal behaviors were microanalytically coded. No opiate-exposure effects were detected. However, mothers of cocaine-exposed infants showed more negative engagement than other mothers. The cocaine-exposed dyads also showed higher overall levels of mismatched engagement states than other dyads, including more negative engagement when the infants were in states of neutral engagement. Infants exposed to heavier levels of cocaine showed more passive-withdrawn negative engagement and engaged in more negative affective matching with their mothers than other infants. Although effect sizes were small, cocaine exposure, especially heavy cocaine exposure, was associated with subtly negative interchanges, which may have a cumulative impact on infants' later development and their relationships with their mothers.

Epilepsy in the United Kingdom: seizure frequency and severity, anti-epileptic drug utilization and impact on life in 1652 people with epilepsy

OBJECTIVES

To describe the clinical characteristics of epilepsy in a representative sample of the UK population, including seizure frequency and severity; overall severity of epilepsy; patterns of anti-epileptic drug (AED) use; and the impact of epilepsy on patients' lives. Secondly, to determine if these characteristics differ according to age.

METHOD

A large, geographically comprehensive survey of people with epilepsy by means of a postal questionnaire distributed by general practitioners to 3455 unselected patients receiving AEDs for epilepsy, regardless of age or type of epilepsy and including all regions of the UK. Data were collected on age and gender; age of onset of seizures; seizure frequency and severity; AED use and adverse effect levels; and impact on life of epilepsy. Sub-analyses were performed with stratification by epilepsy severity and age-group.

RESULTS

There were 1652 completed replies. The mean age was 44.2 years; there were 47.2% males, 48.5% females (4.4% not recorded). The mean age at first seizure, 25.1 years, and the mean duration of epilepsy, 19.7 years, were comparable with previous studies. In the preceding one year, 51.7% of patients had no seizures; 7.9% one seizure, 17.2% 2-9 seizures and 23.2% 10 or more. Sixty-four percent of patients had epilepsy classified as mild and 32% severe. There was a marked and significant decrement of seizure frequency with increasing age. The most commonly used AEDs were carbamazepine (37.4%), valproate (35.7%), phenytoin (29.4%), phenobarbitone or primidone (14.2%) and lamotrigine (10.3%). Monotherapy was used in 68% of patients. Patients taking multiple AEDs reported significantly higher levels of adverse effects and worse seizure control. The major impacts of epilepsy on life were work and school difficulties, driving prohibition, psychological and social life. The impacts listed varied with the epilepsy severity and age.

CONCLUSIONS

Seizures remain uncontrolled in up to half of all people with epilepsy in the UK with significant impact on work, family and social life. Previously, there has been a deficiency of data on the characteristics of epilepsy in older people, although it is recognized that the condition is of increasing epidemiological importance in this age group. We have found clear differences in the clinical characteristics of epilepsy in older people, particularly that seizure frequency appears to decline with increasing age.

The diagnostic value of finger systolic blood pressure and cold-provocation testing for the vascular component of hand-arm vibration syndrome in health surveillance

BACKGROUND

Hand-arm vibration syndrome (HAVS) is a complex condition with vascular, sensorineural and musculoskeletal components. A number of quantitative tests have been used for assisting in the diagnosis of HAVS and grading disease severity.

AIMS

To investigate and compare the diagnostic value of finger systolic blood pressure (FSBP) and rewarming of finger skin temperature (FST) following cold-provocation testing, in the assessment of vascular HAVS.

METHODS

Twenty-four individuals with vascular HAVS (Stockholm Workshop stage 2 or 3V) and 22 control subjects underwent FSBP measurements at 30, 15 and 10 degrees C and monitoring of FST following immersion of the hands in water at 15 degrees C for 5 min.

RESULTS

There was a significant reduction in median FSBP% in the vascular HAVS group in the change in FSBP from 30 to 15 degrees C adjusted for brachial blood pressure (FSBPC%). There was no difference in the median time for FST to rewarm by 4 degrees C between HAVS cases and controls. The sensitivity and specificity of FSBP to discriminate between the groups varied between 44 and 61% and 91 and 95%, respectively. The sensitivity and specificity for the time for FST to rewarm by 4 degrees C were 71 and 77%.

CONCLUSIONS

There is little evidence that the described form of finger rewarming after cold-provocation testing is a useful diagnostic test for vascular HAVS, although it may have some moderate influence in ruling out vascular problems. Based on our data, the FSBP may also have limited use in confirming a positive diagnosis of vibration-induced vascular problems. The higher specificity of the FSBP test suggests it may have some value in ruling out the vascular component of HAVS. The data from this study do not confirm the diagnostic power of FSBP for the vascular component of HAVS reported by a few other investigators.

Resistance to beta-lactam antibiotics

beta-lactams have a long history in the treatment of infectious diseases, though their use has been and continues to be confounded by the development of resistance in target organisms. beta-lactamases, particularly in Gram-negative pathogens, are a major determinant of this resistance, although alterations in the beta-lactam targets, the penicillin-binding proteins (PBPs), are also important, especially in Gram-positive pathogens. Mechanisms for the efflux and/or exclusion of these agents also contribute, though often in conjunction these other two. Approaches for overcoming these resistance mechanisms include the development of novel beta-lactamase-stable beta-lactams, beta-lactamase inhibitors to be employed with existing beta-lactams, beta-lactam compounds that bind strongly to low-affinity PBPs and agents that potentiate the activity of existing beta-lactams against low-affinity PBP-producing organisms.

Efflux-mediated multiresistance in Gram-negative bacteria

Multiresistance in Gram-negative pathogens, particularly Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter spp. and the Enterobacteriaceae, is a significant problem in medicine today. While multiple mechanisms often contribute to multiresistance, a broadly distributed family of three-component multidrug efflux systems is an increasingly recognised determinant of both intrinsic and acquired multiresistance in these organisms. Homologues of these efflux systems are also readily identifiable in the genome sequences of a wide range of Gram-negative organisms, pathogens and non-pathogens alike, where they probably promote efflux-mediated resistance to multiple antimicrobials. Significantly, these systems often accommodate biocides, raising the spectre of biocide-mediated selection of multiresistance in Gram-negative pathogens. While there is some debate as to the natural function of these efflux systems, only some of which are inducible by their antimicrobial substrates, their contribution to resistance in a variety of pathogens nonetheless makes them reasonable targets for therapeutic intervention. Indeed, given the incredible chemical diversity of substrates accommodated by these efflux systems, it is likely that many novel or yet to be discovered antimicrobials will themselves be efflux substrates and, as such, efflux inhibitors may become an important component of Gram-negative antimicrobial therapy.

Psychological distress associated with waiting for results of diagnostic investigations for breast disease

This paper presents the results of a multi-method research project investigating the psychological distress associated with waiting for results of diagnostic investigations in a delayed-results breast clinic. A cohort of 126 women completed standardized psychometric instruments to assess anxiety, mood and coping over 3 days. Semi-structured interviews were conducted with 20 respondents. The findings indicate that waiting sustained but did not exacerbate psychological distress. Peri-diagnostic anxiety, depression, uncertainty and confusion were associated with anxiety levels immediately following triple assessment. Women leaving the clinic with low anxiety retained this composure throughout the peri-diagnostic period. Those in the moderate and high anxiety groups recorded sustained anxiety, depression, uncertainty and confusion, with mean scores comparable to and exceeding those reported by psychiatric out-patients. Coping during the waiting period was typically accomplished by emotion-focused strategies. Qualitative data suggested the delayed-results clinic structure may facilitate psychological preparation for test results.

A critique of a UK standardized test of finger rewarming after cold provocation in the diagnosis and staging of hand-arm vibration syndrome

BACKGROUND

Accurate diagnosis and staging of hand-arm vibration syndrome (HAVS) is important in health surveillance of vibration-exposed workers and the substantial number of related medico-legal cases. The measurement of the rewarming rate of fingers after cold provocation to the hands (CPT) has been suggested as a useful test in diagnosing HAVS.

AIM

To investigate the diagnostic value of a standardized version of the CPT test using a 15 degrees C cold challenge for 5 min applied in the recent compensation assessment of UK miners.

METHODS

Analysis of a subset of UK miners assessed at our unit, together with data from a small repeatability study of the standardized CPT in normal subjects.

RESULTS

Rewarming time in the CPT was significantly lower in those subjects classified as vascular Stockholm stage 0 compared with Stockholm stages 1-3 combined, but did not discriminate between the stages of abnormality. Using the suggested cut-off in the CPT test, the sensitivity and specificity were calculated as 43 and 78%, respectively. Receiver operator characteristic analysis suggested that the rewarming time of highest accuracy gave a sensitivity of 66% and specificity of 59%. In 10 miners who reported unilateral hand blanching, there was no significant difference in CPT measurements between blanching and non-blanching hands. Repeat CPT measurements in normal subjects suggested mean differences of 52 and 107 s for each hand, and the Bland-Altman coefficient of repeatability was approximately 600 s for all fingers.

CONCLUSION

Single application of this standardized CPT test may have limited value in diagnosing the vascular component of HAVS in an individual.

Mechanisms of bacterial biocide and antibiotic resistance

Resistance to antibiotics is increasingly commonplace amongst important human pathogens. Although the mechanism(s) of resistance vary from agent to agent they typically involve one or more of: alteration of the drug target in the bacterial cell, enzymatic modification or destruction of the drug itself, or limitation of drug accumulation as a result of drug exclusion or active drug efflux. While most of these are agent specific, providing resistance to a single antimicrobial or class of antimicrobial, there are currently numerous examples of efflux systems that accommodate and, thus, provide resistance to a broad range of structurally unrelated antimicrobials--so-called multidrug efflux systems. Resistance to biocides is less common and likely reflects the multiplicity of targets within the cell as well as the general lack of known detoxifying enzymes. Resistance typically results from cellular changes that impact on biocide accumulation, including cell envelope changes that limit uptake, or expression of efflux mechanisms. Still, target site mutations leading to biocide resistance, though rare, are known. Intriguingly, many multidrug efflux systems also accommodate biocides (e.g. triclosan) such that strains expressing these are both antibiotic- and biocide-resistant. Indeed, concern has been expressed regarding the potential for agents such as triclosan to select for strains resistant to multiple clinically-relevant antibiotics. Some of the better characterized examples of such multidrug efflux systems can be found in the opportunistic pathogen Pseudomonas aeruginosa where they play an important role in the noted intrinsic and acquired resistance of this organism to antibiotics and triclosan. These tripartite pumps include an integral inner membrane drug-proton antiporter, an outer membrane- and periplasm-spanning channel-forming protein and a periplasmic link protein that joins these two. Expression of efflux genes is governed minimally by the product of a linked regulatory gene that is in most cases the target for mutation in multidrug resistant strains hyperexpressing these efflux systems. Issues for consideration include the natural function of these efflux systems and the therapeutic potential of targeting these systems in combating acquired multidrug resistance.

Unusual pheromone receptor neuron responses in heliothine moth antennae derived from inter-species imaginal disc transplantation

Single-cell electrophysiological recordings were obtained from olfactory receptor neurons housed in sensilla trichodea along the adult antennae arising from transplantation of the antennal imaginal discs between larval male Helicoverpa zea and Heliothis virescens. The olfactory receptor neurons from the majority of type C sensilla sampled on transplanted antennae displayed response characteristics consistent with those of the species that donated the antennae. However, some of the sensilla type C sampled in either transplant type contained olfactory receptor neurons that responded in a manner typical of the recipient species or other neurons that have not previously been found in the type C sensilla of either species. The single-cell data help to explain behavioral results showing that some transplant males do fly upwind to both species' pheromone blends, an outcome not expected based on known antennal sensory phenotypes. Our results suggest that host tissue can influence antennal olfactory receptor neuron development, and further that because of a common phylogenetic ancestry the donor tissue has the genetic capability to produce a variety of sensillar and receptor types.

Information recalled by women taking anti-epileptic drugs for epilepsy: a questionnaire study

Women with epilepsy have different needs from men, particularly associated with childbearing. Despite clinical guidelines, the care of women with epilepsy remains suboptimal. The aim of this study was to establish whether women with epilepsy recall being given information on topics relating to childbearing. Design of study and methods included a postal questionnaire study of 795 women with epilepsy and of childbearing age. The respondents were identified through both general practices and hospital clinics as part of the Clinical Standards Advisory Group study into Epilepsy Services. Of those women who considered the questions personally relevant, 38-48% recalled receiving information about contraception, pre-pregnancy planning, folic acid and teratogenicity, with lower overall proportions among adolescent women. The proportions that recalled receiving information about vitamin K, safety in child-care and breast-feeding were lower at 12, 24 and 24%, respectively. While it is recognised that information provided may not be recalled, our results suggest that further measures are required to improve the effectiveness of information provision in the UK in relation to women of childbearing age with epilepsy.

Central and autonomic system signs with in utero drug exposure

AIMS

To determine risk for central nervous system/autonomic nervous system (CNS/ANS) signs following in utero cocaine and opiate exposure.

METHODS

A multisite study was designed to determine outcomes of in utero cocaine and opiate exposure. A total of 11 811 maternal/infant dyads were enrolled. Drug exposed (EXP) infants were identified by maternal self report of cocaine or opiate use or by meconium testing. Of 1185 EXP, meconium analysis confirmed exposure in 717 to cocaine (CO) only, 100 to opiates (OP), and 92 to opiates plus cocaine (OP+CO); 276 had insufficient or no meconium to confirm maternal self report. Negative exposure history was confirmed in 7442 by meconium analysis and unconfirmed in 3184. Examiners masked to exposure status, assessed each enrolled infant. Using generalised estimating equations, adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated for manifesting a constellation of CNS/ANS outcomes and for each sign associated with cocaine and opiate exposure.

RESULTS

Prevalence of CNS/ANS signs was low in CO, and highest in OP+CO. Signs were significantly related to one another. After controlling for confounders, CO was associated with increased risk of manifesting a constellation of CNS/ANS outcomes, OR (95% CI): 1.7 (1.2 to 2.2), independent of OP effect, OR (95% CI): 2.8 (2.1 to 3.7). OP+CO had additive effects, OR (95% CI): 4.8 (2.9 to 7.9). Smoking also increased the risk for the constellation of CNS/ANS signs, OR (95% CI) of 1.3 (1.04 to 1.55) and 1.4 (1.2 to 1.6), respectively, for use of less than half a pack per day and half a pack per day or more.

CONCLUSION

Cocaine or opiate exposure increases the risk for manifesting a constellation of CNS/ANS outcomes.

Mechanisms of bacterial biocide and antibiotic resistance

Resistance to antibiotics is increasingly commonplace amongst important human pathogens. Although the mechanism(s) of resistance vary from agent to agent they typically involve one or more of: alteration of the drug target in the bacterial cell, enzymatic modification or destruction of the drug itself, or limitation of drug accumulation as a result of drug exclusion or active drug efflux. While most of these are agent specific, providing resistance to a single antimicrobial or class of antimicrobial, there are currently numerous examples of efflux systems that accommodate and, thus, provide resistance to a broad range of structurally unrelated antimicrobials -- so-called multidrug efflux systems. Resistance to biocides is less common and likely reflects the multiplicity of targets within the cell as well as the general lack of known detoxifying enzymes. Resistance typically results from cellular changes that impact on biocide accumulation, including cell envelope changes that limit uptake, or expression of efflux mechanisms. Still, target site mutations leading to biocide resistance, though rare, are known. Intriguingly, many multidrug efflux systems also accommodate biocides (e.g. triclosan) such that strains expressing these are both antibiotic- and biocide-resistant. Indeed, concern has been expressed regarding the potential for agents such as triclosan to select for strains resistant to multiple clinically-relevant antibiotics. Some of the better characterized examples of such multidrug efflux systems can be found in the opportunistic pathogen Pseudomonas aeruginosa where they play an important role in the noted intrinsic and acquired resistance of this organism to antibiotics and triclosan. These tripartite pumps include an integral inner membrane drug-proton antiporter, an outer membrane- and periplasm-spanning channel-forming protein and a periplasmic link protein that joins these two. Expression of efflux genes is governed minimally by the product of a linked regulatory gene that is in most cases the target for mutation in multidrug resistant strains hyperexpressing these efflux systems. Issues for consideration include the natural function of these efflux systems and the therapeutic potential of targeting these systems in combating acquired multidrug resistance.

Cancer Research UK procedures in manufacture and toxicology of radiotracers intended for pre-phase I positron emission tomography studies in cancer patients

Radiolabelled compounds formulated for injection (radiopharmaceuticals), are increasingly being employed in drug development studies. These can be used in tracer amounts for either pharmacokinetic or pharmacodynamic studies. Such radiotracer studies can also be carried out early in man, even prior to conventional Phase I clinical testing. The aim of this document is to describe procedures for production and safety testing of oncology radiotracers developed for imaging by positron emission tomography in cancer patients. We propose strategies for overcoming the inability to produce compounds in sufficient quantities via the radiosynthetic routes for full chemical characterisation and toxicology testing including (i) independent confirmation as far as possible that the stable compound associated with the radiopharmaceutical is identical to the non-labelled compound, (ii) animal toxicity studies with > or = 10 times (typically 100 times) the intended tracer dose in humans scaled by body surface area, and (iii) patient monitoring during the radiotracer positron emission tomography clinical trial.

The psychological impact of post-operative arm morbidity following axillary surgery for breast cancer: a critical review

In this paper we review the published research that has investigated the psychological impact of arm morbidity associated with axillary dissection for early breast cancer. This critique is particularly timely given the drive towards minimally invasive techniques, such as sentinel node biopsy, which aim to reduce the incidence and severity of post-operative arm problems. Reported symptoms are multifactorial and include numbness, pain, swelling, weakness/stiffness, and restricted shoulder mobility of the affected arm. Conclusions from the few studies that have investigated the severity, incidence, duration and psychological impact of such disability are often limited by methodological problems. We identify these limitations and examine assessment tools used to determine the psychological impact of lymphoedema. The paper highlights the need for methodological rigor in study design, and the careful selection of appropriate, sensitive, reliable and clinically meaningful outcome measures to evaluate the impact of post-operative arm morbidity.

SmeDEF multidrug efflux pump contributes to intrinsic multidrug resistance in Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is an emerging nosocomial pathogen that displays high-level intrinsic resistance to a variety of structurally unrelated antimicrobial agents. Efflux mechanisms are known to contribute to acquired multidrug resistance in this organism, and indeed, one such multidrug efflux system, SmeDEF, was recently identified. Still, the importance of SmeDEF to intrinsic antibiotic resistance in S. maltophilia had not yet been determined. Reverse transcription-PCR confirmed expression of the smeDEF genes in wild-type S. maltophilia, and deletion of smeE or smeF in wild-type strains rendered the mutants hypersusceptible to several antimicrobials, suggesting that SmeDEF contributes to intrinsic antimicrobial resistance in this organism. Expression of smeDEF was also enhanced in an in vitro-selected multidrug-resistant mutant, although deletion of smeF but not of smeE in these mutants compromised antimicrobial resistance. Apparently, hyperexpressed SmeF is capable of functioning with additional multidrug efflux components to promote multidrug resistance in S. maltophilia.

Fluoroquinolone susceptibilities of efflux-mediated multidrug-resistant Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Burkholderia cepacia

The antibacterial activities of seven fluoroquinolones (ciprofloxacin, BAYy3118, clinafloxacin, gemifloxacin, moxifloxacin, sparfloxacin and trovafloxacin) against isogenic efflux-mediated multidrug-resistant strains of Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Burkholderia cepacia, were compared. The results indicate that these fluoroquinolones are all substrates for the multidrug efflux systems of these organisms. Clinafloxacin was found generally to be the most active agent against multidrug-resistant strains.

Multidrug resistance in Gram-negative bacteria

Broadly specific, so-called multidrug, efflux mechanisms are now known to contribute significantly to intrinsic and acquired multidrug resistance in a number of Gram-negative bacteria, and the boom in bacterial genomics has confirmed the distribution of these systems in all bacteria. This broad distribution of multidrug transporters lends a certain credibility to suggestions that they play a housekeeping role in the cell, beyond any contributions they may make to antimicrobial efflux and resistance. In many instances, these transporters are dispensable, arguing against their carrying out essential cellular functions; nevertheless, the multiplicity of these broadly specific export systems within a given microorganism, often with overlapping substrate specificity, may explain the dispensability of individual exporters. Whatever their intended function, however, their conservation in so many organisms highlights their probable general importance in antimicrobial resistance, particularly in Gram-negative bacteria whose outer membranes work synergistically with many of these export systems to promote drug exclusion.

Multidrug efflux pumps: expression patterns and contribution to antibiotic resistance in Pseudomonas aeruginosa biofilms

Pseudomonas aeruginosa biofilms are intrinsically resistant to antimicrobial chemotherapies. At present, very little is known about the physiological changes that occur during the transition from the planktonic to biofilm mode of growth. The resistance of P. aeruginosa biofilms to numerous antimicrobial agents that are substrates subject to active efflux from planktonic cells suggests that efflux pumps may substantially contribute to the innate resistance of biofilms. In this study, we investigated the expression of genes associated with two multidrug resistance (MDR) efflux pumps, MexAB-OprM and MexCD-OprJ, throughout the course of biofilm development. Using fusions to gfp, we were able to analyze spatial and temporal expression of mexA and mexC in the developing biofilm. Remarkably, expression of mexAB-oprM and mexCD-oprJ was not upregulated but rather decreased over time in the developing biofilm. Northern blot analysis confirmed that these pumps were not hyperexpressed in the biofilm. Furthermore, spatial differences in mexAB-oprM and mexCD-oprJ expression were observed, with maximal activity occurring at the biofilm substratum. Using a series of MDR mutants, we assessed the contribution of the MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY efflux pumps to P. aeruginosa biofilm resistance. These analyses led to the surprising discovery that the four characterized efflux pumps do not play a role in the antibiotic-resistant phenotype of P. aeruginosa biofilms.

The impact of an incentive-based worksite health promotion program on modifiable health risk factors

A health promotion program consisting of an annual health screening and financial rebates for good health practices was offered to all 2540 employees of Salt Lake County in Utah. Changes in health risks were measured for the 304 full time employees who participated in assessments for four years. Significant improvements were seen in body fat, cholesterol, systolic and diastolic blood pressure, seat belt use, and overall physical health among the high risk group and the low risk group. There was a net increase in the number of people in the high risk group over the four year period.

The validation of a quality of life scale to assess the impact of arm morbidity in breast cancer patients post-operatively

This paper documents the validation of a quality of life scale (QOL) designed to assess the impact of arm morbidity on patients following breast cancer surgery. A four item arm subscale was developed to supplement a multi-dimensional, validated breast cancer QOL tool, the functional assessment of cancer therapy (FACT-B.) The new questionnaire, the FACT-B + 4, was validated on 279 women participating in a trial of sentinel node guided axillary therapy and 29 women attending a lymphoedema clinic. The subscale demonstrated good internal consistency (alpha co-efficient = 0.62 to 0.88) and stability (test-retest reliability = 0.97). Lymphoedema patients reported significantly greater arm problems than a matched sample of pre-operative trial participants. The lymphoedema group also scored lower than trial patients on the FACT-B + 4 indicating a poorer quality of life (p < 0.05). A subset of 66 trial patients who had completed three consecutive assessments was used to evaluate the sensitivity of the questionnaire to change over time. Scores on the FACT-B + 4 were found to decline significantly between the pre-operative assessment and post-operative assessment at 1 month. Arm problems significantly increased during this period. FACT-B + 4 score increased again from 1 month to 12 weeks post-surgery and symptoms reduced, as the extent of arm morbidity resolved. The FACT-B + 4 appears to be psychometrically robust and sensitive to patient rehabilitation, making it suitable for use in longitudinal surgical trials. Given the dearth of existing scales available to measure arm morbidity, we hope this new tool will prove useful to researchers.