Antimicrobial usage in farm animal practices in the UK: A mixed-methods approach

Antimicrobial resistance (AMR) is a growing One Health problem. Monitoring antimicrobial usage in farm animals is crucial for tackling AMR. A cohort study using the electronic clinical records during 2019 from 23 farm animal veterinary practices across the UK belonging to two corporate groups, with a range of 2-14 veterinarians per practice, estimated the usage of antimicrobials and highest priority critically important antimicrobials (HP-CIAs). Risk factors for using HP-CIAs were evaluated using hierarchical mixed-effects logistic regression modelling with practice ID and farm ID added as random effects. Using a qualitative approach, veterinarians from one of the participating practice groups were recruited for a qualitative study to explore the barriers and facilitators in relation to antimicrobial use. Semi-structured interviews were conducted with participants and analysed thematically. During the year 2019, 98,824 antimicrobial prescribing events overall were recorded from the treatment records of the 23 participating practices. The median count of antimicrobial events per practice was 3226 (range 263-22,159). There were 17,111/98,824 (17.3%) HP-CIAs events overall, with a median of 15.4% at practice level (range 4.8-22.1%). Penicillins were the most frequently used antimicrobials 29,539/98,824 (29.9%) followed by tetracyclines 19,015/98,824 (19.2%). HP-CIA use was strongly clustered, with more clustering seen at the farm level (intraclass correlation coefficient (ICC)= 0.56) than at the practice level (ICC= 0.32). Country, route of administration, season and practice type were significantly associated with the usage of HP-CIAs. Four main themes were identified from the analysis of the veterinarians' interviews: pressure from the industry, drug-related factors, knowledge level of veterinarians and clinical factors. Supermarket contracts and farm assurance schemes were facilitators for reducing antimicrobial use and the use of HP-CIAs. Ease of administration and the withdrawal period of the antimicrobials influenced veterinarians' choice of antimicrobials. The clinical condition and clinical signs presented on farm were reported to influence participating veterinarians' prescribing decision. Participants showed a good understanding of AMR, responsible use of antimicrobials and the term 'critically important antimicrobials'. In conclusion, integrating the quantitative and qualitative findings can inform policymaking on antimicrobials stewardship in farm practice. By estimating the relative levels of clustering of antimicrobial use at the practice and farm level, as well as identifying major risk factors for using HP-CIAs, more targeted interventions can be designed to promote responsible antimicrobial use in farm practice. Furthermore, better understanding the industry pressures on farms to reduce antimicrobials usage could reduce the barriers for responsible antimicrobial use by veterinarians.

Advanced practice physiotherapy care in emergency departments for patients with musculoskeletal disorders: a pragmatic cluster randomized controlled trial and cost analysis

BACKGROUND

Advanced practice physiotherapy (APP) models of care where physiotherapists are primary contact emergency department (ED) providers are promising models of care to improve access, alleviate physicians' burden, and offer efficient centered patient care for patients with minor musculoskeletal disorders (MSKD).

OBJECTIVES

To compare the effectiveness of an advanced practice physiotherapist (APPT)-led model of care with usual ED physician care for persons presenting with a minor MSKD, in terms of patient-related outcomes, health care resources utilization, and health care costs.

METHODS

This trial is a multicenter stepped-wedge cluster randomized controlled trial (RCT) with a cost analysis. Six Canadian EDs (clusters) will be randomized to a treatment sequence where patients will either be managed by an ED APPT or receive usual ED physician care. Seven hundred forty-four adults with a minor MSKD will be recruited. The main outcome measure will be the Brief Pain Inventory Questionnaire. Secondary measures will include validated self-reported disability questionnaires, the EQ-5D-5L, and other health care utilization outcomes such as prescription of imaging tests and medication. Adverse events and re-visits to the ED for the same complaint will also be monitored. Health care costs will be measured from the perspective of the public health care system using time-driven activity-based costing. Outcomes will be collected at inclusion, at ED discharge, and at 4, 12, and 26 weeks following the initial ED visit. Per-protocol and intention-to-treat analyses will be performed using linear mixed models with a random effect for cluster and fixed effect for time.

DISCUSSION

MSKD have a significant impact on health care systems. By providing innovative efficient pathways to access care, APP models of care could help relieve pressure in EDs while providing efficient care for adults with MSKD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05545917 . Registered on September 19, 2022.

Social Isolation in Community-Dwelling Older Adults During COVID-19: Understanding the Role of Resilience

The COVID-19 pandemic increased social isolation for many older adults, causing concern for their health and well-being. To enhance understanding of how community-dwelling older adults were impacted by prolonged social isolation during COVID-19, a qualitative descriptive study was conducted to: (1) explore the self-reported factors supporting their resilience during COVID-19 related social isolation, and (2) to help understand the intentional and unintentional outcomes of the government mandated health measures. A total of 19 community dwelling older adults were sampled. Factors that supported older adults' resilience during COVID-19 included maintaining positivity, drawing on historical experiences of resilience and finding opportunities to connect with their community. However, collective safety came with losses: such as time, freedom, opportunity, engagement, and initiative. The findings provide insight on contributing factors to resilience against social isolation in older adults and suggest the value of collective, community-based approaches to build resilience across variable contexts in this population.

PEDAL protocol: a prospective single-arm paired comparison of multiparametric MRI and 18F-DCPFyl PSMA PET/CT to diagnose prostate cancer

INTRODUCTION

Prostate-specific membrane antigen positron emission tomography (PSMA-PET) has emerged as valuable imaging to assessing metastatic disease in prostate malignancy. However, there has been limited studies exploring the utility PSMA-PET as primary imaging assessing for index lesions prior to biopsy. The primary objective of this study is to compare the diagnostic accuracy of 18-fluorine PSMA (18F DCFPyL PSMA) PET scans to multiparametric MRI (mpMRI) to detect primary prostate cancer at prostate biopsy.

METHODS AND ANALYSIS

The PEDAL trial is a multicentre, prospective, single-arm, paired comparison, non-randomised phase III trial in subjects considered for diagnostic prostate biopsy. Subjects who are eligible for a diagnostic mpMRI prostate will undergo additional same-day 18 F DCFPyl PSMA PET/CT of the chest, abdomen and pelvis. Software coregistration of the mpMRI and PSMA-PET/CT images will be performed. The reporting of the mpMRI prostate, PSMA-PET/CT and PSMA PET/MRI coregistration will be performed blinded. The diagnostic accuracy of PSMA PET/CT alone, and in combination with mpMRI, to detect prostate cancer will be assessed. Histopathology at prostate biopsy will be used as the reference standard. Sample size calculations estimate that 240 subjects will need to be recruited to demonstrate 20% superiority of PSMA-PET/CT. The sensitivity, specificity, positive predictive value and negative predictive value of the combination of mpMRI prostate and PSMA PET/CT compared with targeted and systematic prostate biopsy will be evaluated. It is hypothesised that PSMA PET/CT combined with mpMRI prostate will have improved diagnostic accuracy compared with mpMRI prostate alone for detection of prostate cancer in biopsy-naïve men, resulting in a significant impact on patient management.

ETHICS AND DISSEMINATION

This study was approved by the independent Human Research Ethics Committee. Results will be published in peer-reviewed medical journals with eligible investigators will significantly contribute.

TRIAL REGISTRATION NUMBER

ACTRN12620000261910.

Removal of uterine polyps: clinical management and surgical approach

Endometrial polyps have a reported prevalence from 7.8% up to 30% and are one of the most cost-consuming gynecological conditions for our specialty. There are strong practitioner beliefs that surgical removal of endometrial polyps is highly beneficial, particularly for those with abnormal uterine bleeding and infertility. Additionally, polypectomy is indicated to reduce the risk of malignancy. Transvaginal ultrasound is the first-line diagnostic option for detection of endometrial polyps, while sonohysterography has similar accuracy as hysteroscopy in the diagnostic confirmation. Blind dilatation and curettage is not recommended for polyp removal; rather, hysteroscopy in the operating room and office setting using small-diameter hysteroscopic equipment is the standard approach. This can be performed without anesthesia in most women. While hysteroscopy is an effective method for polypectomy with a low complication rate, it is unknown whether this is truly beneficial for reproductive-age women with infertility and prior assisted reproduction therapy. The risk of malignancy in women with postmenopausal bleeding justifies the necessity of polypectomy with histologic tissue examination. In asymptomatic women, the risk of malignancy is low, and there are no known benefits of polyp removal in the prevention of malignant transformation. Cost-effective studies remain to be done to provide us with the optimal approach to endometrial polyps including the management of asymptomatic and/or infertile women, ideal location including office-based or the operating room setting, complication prevention including intrauterine adhesions, and recurrence issues.

[18F]DCFPyL PET/CT in detection and localization of recurrent prostate cancer following prostatectomy including low PSA < 0.5 ng/mL

PURPOSE

The primary aim of this retrospective multicenter analysis was to assess the performance of PSMA PET/CT using [¹⁸F]DCFPyL in the detection and localization of recurrent prostate cancer post radical prostatectomy (RP). Particular reference is given to low PSA groups < 0.5 ng/mL to aid discussion around the inclusion of this group in PSMA guidelines and funding pathways.

METHODS

Retrospective analysis of combined PSMA database patients from centers in Australia and New Zealand. Two hundred twenty-two patients presenting with recurrence post RP were stratified into five PSA groups (ng/mL): 0-0.19, 0.2-0.49, 0.5-0.99, 1-1.99, and ≥ 2. Lesions detected by [¹⁸F]DCFPyL PET/CT were recorded as local recurrence, locoregional nodes, and metastases.

RESULTS

Of 222 patients, 155 (69.8%) had evidence of abnormal uptake suggestive of recurrent prostate cancer. The detection efficacies for [¹⁸F]DCFPyL PET/CT were 91.7% (44/48) for PSA levels ≥ 2 ng/mL, 82.1% (23/28) for PSA levels 1-1.99 ng/mL, 62.8% (27/43) for PSA levels 0.5-0.99 ng/mL, 58.7% (54/92) for PSA levels 0.2-0.49 ng/mL, and 63.6% (7/11) for PSA levels ≤ 0.2 ng/mL. In those with PSA < 0.5 ng/mL, 47.6% (49/103) had detectable lesions, 71.4% (35/49) had disease confined to the pelvis, 22.4% (11/49) had prostate bed recurrence, 49.0% (24/49) had pelvic lymph nodes, and 28.6% (14/49) had extra pelvic disease.

CONCLUSION

[¹⁸F]DCFPyL PET/CT has a high detection rate in recurrence following RP even at low PSA levels with similar detection levels in the PSA subgroups < 0.5 ng/mL. Employing rigid PSA thresholds when constructing guidelines for PSMA PET/CT funding eligibility may result in a significant number of patients below such thresholds having delayed or inappropriate treatment.

The role of intra-operative cell salvage in patient blood management for revision hip arthroplasty: a prospective cohort study

Cell salvage is an important component of blood management in patients undergoing revision hip arthroplasty surgery. However concerns regarding efficacy and patient selection remain. The aims of this study were to describe intra-operative blood loss, cell salvage re-infusion volumes and red blood cell transfusion rates for revision hip procedures and to identify factors associated with the ability to salvage sufficient blood intra-operatively to permit processing and re-infusion. Data were collected from a prospective cohort of 664 consecutive patients undergoing revision hip surgery at a single tertiary centre from 31 March 2015 to 1 April 2018. Indications for revision surgery were aseptic (n = 393 (59%)) fracture (n = 160 (24%)) and infection (n = 111 (17%)). Salvaged blood was processed and re-infused when blood loss exceeded 500 ml. Mean (SD) intra-operative blood loss was 1038 (778) ml across all procedures. Salvaged blood was re-infused in 505 of 664 (76%) patients. Mean (SD) re-infusion volume was 253 (169) ml. In total, 246 of 664 (37%) patients received an allogeneic red blood cell transfusion within 72 h of surgery. Patients undergoing femoral component revision only (OR (95%CI) 0.41 (0.23-0.73)) or acetabular component revision only (0.53 (0.32-0.87)) were less likely to generate sufficient blood salvage volume for re-infusion compared with revision of both components. Compared with aseptic indications, patients undergoing revision surgery for infection (1.87 (1.04-3.36)) or fracture (4.43 (2.30-8.55)) were more likely to generate sufficient blood salvage volume for re-infusion. Our data suggest that cell salvage is efficacious in this population. Cases where the indication is infection or fracture and where both femoral and acetabular components are to be revised should be prioritised.

Risk factors and mitigation of influenza among Indigenous children in Australia, Canada, United States, and New Zealand: a scoping review

AIM

This review considers prominent risk factors and mitigation strategies of influenza among Indigenous children.

METHODS

Seven electronic databases were searched from the period of 2004-2017 to locate articles discussing influenza among Indigenous children in the developed circumpolar nations of Australia, Canada, United States, and New Zealand. Articles selected for inclusion discussed influenza among Indigenous children as either individuals or as a part of a community. Ancestry searches of articles meeting the review criteria were also undertaken to discern seminal research in this topic area.

RESULTS

From the 39 primary research studies included, marked risk factors and mitigation strategies of influenza among Indigenous children were identified using inductive analysis. Notable risk factors included age under 2 years, cigarette smoke exposure, presence of a chronic illness, and crowded living conditions. Successful mitigation of influenza for Indigenous children included strategies to improve vaccine coverage, provision of health education, and policy change.

CONCLUSION

In the past, the impact of influenza upon Indigenous communities has been devastating for both children and their families. By utilizing existing public health infrastructure and collaborating with culturally unique Indigenous groups, preventive action for Indigenous children at significant risk of contracting influenza can be realized.

Randomised positive control trial of NSAID and antimicrobial treatment for calf fever caused by pneumonia

One hundred and fifty-four preweaning calves were followed between May and October 2015. Calves were fitted with continuous monitoring temperature probes (TempVerified FeverTag), programmed so a flashing light emitting diode (LED) light was triggered following six hours of a sustained ear canal temperature of ≥39.7°C. A total of 83 calves (61.9 per cent) developed undifferentiated fever, with a presumptive diagnosis of pneumonia through exclusion of other calf diseases. Once fever was detected, calves were randomly allocated to treatment groups. Calves in group 1 (NSAID) received 2 mg/kg flunixin meglumine (Allevinix, Merial) for three consecutive days and group 2 (antimicrobial) received 6 mg/kg gamithromycin (Zactran, Merial). If fever persisted for 72 hours after the initial treatment, calves were given further treatment (group 1 received antimicrobial and group 2 received NSAID). Calves in group 1 (NSAID) were five times more likely (P=0.002) to require a second treatment (the antimicrobial) after 72 hours to resolve the fever compared with the need to give group 2 (antimicrobial) calves a second treatment (NSAID). This demonstrates the importance of ongoing monitoring and follow-up of calves with respiratory disease. However, of calves with fever in group 1 (NSAID), 25.7 per cent showed resolution following NSAID-only treatment with no detrimental effect on the development of repeated fever or daily live weight gain. This suggests that NSAID alone may be a useful first-line treatment, provided adequate attention is given to ongoing monitoring to identify those cases that require additional antimicrobial treatment.

Individuals with current suicidal ideation demonstrate implicit "fearlessness of death"

BACKGROUND AND OBJECTIVES

Suicidal behaviour has proved to be difficult to predict, due in part to the particular limitations of introspection within suicidality. In an effort to overcome this, recent research has demonstrated the utility of indirect measures of "implicit" attitudes within the study of suicidality. However, research to date has focused predominantly on implicit self-evaluations and self-death associations. No work has examined implicit evaluations of death, despite the theoretical importance of such evaluations; "fearlessness of death" is central to both the Interpersonal Theory of Suicide and the Integrated Motivational-Volitional model of suicide..

METHODS

Twenty-three psychiatric patients with current suicidal ideation and twenty-five normative university students completed two versions of the Implicit Relational Assessment Procedure (IRAP) that targeted evaluations of death. One task specified personal death (i.e., was self-focused) and the other targeted death in the abstract.

RESULTS

Self-focused evaluations of death reliably distinguished between the two groups, correctly classifying 74% of cases, but evaluations of death in the abstract did not. The suicidal group produced specific biases indicating a rejection of the negativity of death. Results are consistent with the definition of suicidality as involving a self-focused wish to die..

LIMITATIONS

For ethical reason, suicidal behaviours were not assessed in the normative group. Groups were therefore not mutually exclusive. This may have decreased the specificity of the IRAP.

CONCLUSIONS

Suicidal ideation is associated with an implicit "fearlessness of death". The utility of implicit death-evaluations should therefore be considered alongside self-evaluations and self-death associations in the future..

Permeability analysis of neuroactive drugs through a dynamic microfluidic in vitro blood-brain barrier model

This paper presents the permeability analysis of neuroactive drugs and correlation with in vivo brain/plasma ratios in a dynamic microfluidic blood-brain barrier (BBB) model. Permeability of seven neuroactive drugs (Ethosuximide, Gabapentin, Sertraline, Sunitinib, Traxoprodil, Varenicline, PF-304014) and trans-endothelial electrical resistance (TEER) were quantified in both dynamic (microfluidic) and static (transwell) BBB models, either with brain endothelial cells (bEnd.3) in monoculture, or in co-culture with glial cells (C6). Dynamic cultures were exposed to 15 dyn/cm(2) shear stress to mimic the in vivo environment. Dynamic models resulted in significantly higher average TEER (respective 5.9-fold and 8.9-fold increase for co-culture and monoculture models) and lower drug permeabilities (average respective decrease of 0.050 and 0.052 log(cm/s) for co-culture and monoculture) than static models; and co-culture models demonstrated higher average TEER (respective 90 and 25% increase for static and dynamic models) and lower drug permeability (average respective decrease of 0.063 and 0.061 log(cm/s) for static and dynamic models) than monoculture models. Correlation of the resultant logP e values [ranging from -4.06 to -3.63 log(cm/s)] with in vivo brain/plasma ratios (ranging from 0.42 to 26.8) showed highly linear correlation (R (2) > 0.85) for all model conditions, indicating the feasibility of the dynamic microfluidic BBB model for prediction of BBB clearance of pharmaceuticals.

A multiple-channel, multiple-assay platform for characterization of full-range shear stress effects on vascular endothelial cells

Vascular endothelial cells (VECs), which line blood vessels and are key to understanding pathologies and treatments of various diseases, experience highly variable wall shear stress (WSS) in vivo (1-60 dyn cm(-2)), imposing numerous effects on physiological and morphological functions. Previous flow-based systems for studying these effects have been limited in range, and comprehensive information on VEC functions at the full spectrum of WSS has not been available yet. To allow rapid characterization of WSS effects, we developed the first multiple channel microfluidic platform that enables a wide range (~15×) of homogeneous WSS conditions while simultaneously allowing trans-monolayer assays, such as permeability and trans-endothelial electrical resistance (TEER) assays, as well as cell morphometry and protein expression assays. Flow velocity/WSS distributions between channels were predicted with COMSOL simulations and verified by measurement using an integrated microflow sensor array. Biomechanical responses of the brain microvascular endothelial cell line bEnd.3 to the full natural spectrum of WSS were investigated with the platform. Under increasing WSS conditions ranging from 0 to 86 dyn cm(-2), (1) permeabilities of FITC-conjugated dextran and propidium iodide decreased, respectively, at rates of 4.06 × 10(-8) and 6.04 × 10(-8) cm s(-1) per dyn cm(-2); (2) TEER increased at a rate of 0.8 Ω cm(2) per dyn cm(-2); (3) increased alignment of cells along the flow direction under increasing WSS conditions; and finally (4) increased protein expression of both the tight junction component ZO-1 (~5×) and the efflux transporter P-gp (~6×) was observed at 86 dyn cm(-2) compared to static controls via western blot. We conclude that the presented microfluidic platform is a valid approach for comprehensively assaying cell responses to fluidic WSS.

Contraception in sea-going service personnel

The right to make an informed choice about contraception should be afforded to every individual serving within the United Kingdom (UK) Armed Forces. This article looks at the responsibilities and approach that healthcare professionals should take within a Primary Care setting, summarises the common contraceptive options available, discusses the associated advantages and disadvantages of each technique, and considers operational factors in a military environment that combine to influence the final contraceptive choice an individual makes. Case Study. A 19-year old Able Rate joined the Royal Navy (RN) and at her joining medical it was noted that she had been on Microgynon™ combined oral contraceptive pill for approximately three years. During this time, her menstrual periods remained light; she never experienced adverse effects, demonstrated good compliance, and was happy to remain on this contraceptive regimen. Over the course of the next eighteen months, she was reviewed by a number of Medical Officers and Civilian Medical Practitioners on a quarterly basis, with Microgynon™ re-prescribed on each occasion. The appropriate Defence Medical Information Capability Programme (DMICP) template was used, with weight, smoking status, compliance and any issues or comments documented accordingly. In December 2010, a discussion regarding long-acting reversible contraception (LARC) was documented for the first time. The patient agreed to give LARC some thought and a review appointment was made for one month. She was subsequently started on the progestogen-only pill Cerazette™. It was noted by the consulting doctor that both the patient's mother and grandmother had a positive history of cerebrovascular events and the combined oral contraceptive pill was discontinued. Upon review at two months, the patient reported that she was content on Cerazette™ and wished to continue with this medication. She was amenorrhoeic, highly compliant, had given up smoking and her weight and blood pressure were stable. However, due to supply issues, it was explained that Cerazette™ was no longer a viable option for her. She had no plans to start a family, and was keen to investigate other contraceptive options. Furthermore, she expressed a particular desire to remain amenorrhoeic, as she was due to deploy overseas in the coming months, and not only wanted to avoid the inconvenience of having her period, but also felt it preferable not to have to take a daily pill when considering the constantly changing time zones. She subsequently had the etonogestrel-releasing subdermal implant Nexplanon™ fitted without complication. She has remained amenorrhoeic throughout and this form of long-acting reversible contraception has particularly suited her busy working role and active lifestyle.

Assessment of two essential elements of BVDV control on selected Flemish dairy and beef farms

Bovine viral diarrhea virus (BVDV) is one of the most important viruses to cause disease in cattle worldwide. The virus is endemically present in Belgium. Clinical diagnosis of BVDV infection is difficult. Therefore, monitoring through testing is necessary to detect the presence of the virus on farms. As vaccination alone does not suffice for eradication, a combination of measures is required for successful control. Via a questionnaire, the BVDV policy on 241 selected Flemish cattle farms was investigated. This revealed some striking results. For the majority of the herds, the BVDV status was unknown (63%), and only 23% had a monitoring program in place. Furthermore, on seven out of ten (71%) BVDV-vaccinating farms, vaccination against BVDV was implemented as a strategy without knowing the actual BVDV status.

OZSPEC-2: an improved broadband high-resolution elliptical crystal x-ray spectrometer for high-energy density physics experiments (invited)

A novel time, space, and energy-resolved x-ray spectrometer has been developed which produces, in a single snapshot, a broadband and relatively calibrated spectrum of the x-ray emission from a high-energy density laboratory plasma. The opacity zipper spectrometer (OZSPEC-1) records a nearly continuous spectrum for x-ray energies from 240 to 5800 eV in a single shot. The second-generation OZSPEC-2, detailed in this work, records fully continuous spectra on a single shot from any two of these three bands: 270-650, 660-1580, and 1960-4720 eV. These instruments thus record thermal and line radiation from a wide range of plasmas. These instruments' single-shot bandwidth is unmatched in a time-gated spectrometer; conversely, other broadband instruments are either time-integrated (using crystals or gratings), lack spectral resolution (diode arrays), or cover a lower energy band (gratings). The OZSPECs are based on the zipper detector, a large-format (100x35 mm) gated microchannel plate detector, with spectra dispersed along the 100 mm dimension. OZSPEC-1 and -2 both use elliptically bent crystals of OHM, RAP, and/or PET. Individual spectra are gated in 100 ps. OZSPEC-2 provides one-dimensional spatial imaging with 30-50 microm resolution over a 1500 microm field of view at the source. The elliptical crystal design yields broad spectral coverage with resolution E/DeltaE>500, strong rejection of hard x-ray backgrounds, and negligible source broadening for extended sources. Near-term applications include plasma opacity measurements, detailed spectra of inertial fusion Hohlraums, and laboratory astrophysics experiments.

Automatic methods for characterization of sexual dimorphism of adult femora: distal femur

Quantifying sex differences in femoral size and shape has extensive applications in forensics and prosthesis design. By applying strong statistical techniques such as principal component analysis (PCA), certain three-dimensional (3D) morphological variations of adult femora can be quantified over various femoral sizes. Coupling this statistical approach with a novel feature generation and extraction technique, localization of statistically significant (p<0.05) features are automatically defined and measured. Also, predefined anatomical landmarks and surgical axes have been calculated automatically. In all methods, femoral scale is controlled as a possible parameter of shape. By extensively comparing measurements across 92 male and 74 female femora, the dimorphic characteristics of the distal femur are shown. These differences have not been accounted for in many prosthetic systems and consequently these systems have limited sizing accuracy.

Admissible and Restrained Revision

As partial justification of their framework for iterated belief revision Darwiche and Pearl convincingly argued against Boutilier's natural revision and provided a prototypical revision operator that fits into their scheme. We show that the Darwiche-Pearl arguments lead naturally to the acceptance of a smaller class of operators which we refer to as admissible. Admissible revision ensures that the penultimate input is not ignored completely, thereby eliminating natural revision, but includes the Darwiche-Pearl operator, Nayak's lexicographic revision operator, and a newly introduced operator called restrained revision. We demonstrate that restrained revision is the most conservative of admissible revision operators, effecting as few changes as possible, while lexicographic revision is the least conservative, and point out that restrained revision can also be viewed as a composite operator, consisting of natural revision preceded by an application of a "backwards revision" operator previously studied by Papini. Finally, we propose the establishment of a principled approach for choosing an appropriate revision operator in different contexts and discuss future work.

Screening of some Australian Flacourtiaceae species for in vitro antioxidant, cytotoxic and antimicrobial activity

A total of 27 methanol extracts obtained from different plant parts of 10 species of rain forest trees belonging to four genera of the Flacourtiaceae and originating from Australia were investigated. In vitro cytotoxicity was measured by an ATP Lite-M assay method against the mouse P388 lymphocytic leukemia cell line. The total antioxidant activity has been assessed based on scavenging activity of stable ABTS free radicals. The minimum inhibition concentration (MIC) was determined by the dilution method performed in 96 well plates against four different microbes. The leaf extract of Casearia sp. (RB 3051), mature stem extract of Casearia grayi and stem extract of Scolopia braunii were found to have most antioxidant activity (IC50 = 2.9 microg/ml), cytotoxic activity (LC50 = 0.89 microg/ml) and antimicrobial activity against all four different microbes, respectively. The results obtained suggested that among the four genera studied Casearia is the most promising in respect of finding significant antioxidant, cytotoxic and also antimicrobial activity.

Initiation of salvage therapy for prostate cancer

Physicians and patients have variable and individual levels of comfort regarding when to begin salvage therapy for rising prostate specific antigen (PSA) after definitive treatment of prostate cancer. The decision to start salvage therapy is a multifactorial process for which few rigorous data or guidelines exist. A questionnaire survey of urologists of the Department of Defense (DoD) Center for Prostate Disease Research (CPDR) was undertaken to obtain current perspectives on when to begin salvage therapy for biochemical failure after definitive therapy. Variables of age, grade, T-stage, nodal status, performance status, latency since prior therapy, PSA velocity, and ploidy were prioritized in four clinical situations; subsequent questions assessed consensus PSA cut-offs for beginning adjuvant therapy in 84 clinical scenarios. Consensus on PSA cut-off points was limited to postoperative radiotherapy (RT), where values of 1.0-1.5 were the mean cut-off points. CPDR urologists consider salvage prostatectomy post-RT only for patients <70-y-old with node negative, grade 2-7 disease and excellent performance status. Ploidy was not generally considered useful in any scenario. Many variables in addition to PSA level are involved in the decision of when to commence adjuvant therapy for initial biochemical failure. These are strikingly interdependent, and few clear absolutes are evident from this questionnaire. This is a point of necessary further research and continued discussion among physicians caring for these patients.

Cellular determinants of the mutational specificity of 1-nitroso-6-nitropyrene and 1-nitroso-8-nitropyrene in the lacI gene of Escherichia coli

We have characterized 202 lacI(-) mutations, and 158 dominant lacI(-d) mutations following treatment of Escherichia coli strains NR6112 and EE125 with 1-nitroso-6-nitropyrene (1,6-NONP), an activated metabolite of the carcinogen 1,6-dinitropyrene. In all, 91% of the induced point mutations occurred at G:C residues. The -(G:C) frameshifts were the dominant mutational class in the lacI(-) collections of both NR6112 and EE125, and in the lacI(-d) collection of NR6112. Frameshift mutations occurred preferentially in runs of guanine residues, and their frequency increased with the length of the reiterated sequence. In strain EE125, which contained the plasmid pKM101, there was a marked stimulation in the frequency of base substitution mutations that was particularly apparent in the lacI(-d) collection. This study completes a comprehensive analysis of 1194 lacI(-) and 348 lacI(-d) mutations induced by either 1,6-NONP or its positional isomer 1-nitroso-8-nitropyrene (1,8-NONP) in strains of E. coli that differ with regard to their ability to carry out nucleotide excision repair and/or their ability to express the translesion synthesis DNA polymerase RI (MucAB) encoded by plasmid pKM101. Among the mutations are 763 frameshift mutations, 367 base substitutions and 47 deletions; these mutations have been characterized at more than 300 distinct sites in the lacI gene. Our studies provide detailed insight into the DNA sequence alterations and mutational mechanisms associated with dinitropyrene mutagenesis. We review the mutational spectra, and discuss cellular lesion repair or tolerance mechanisms that modulate the observed mutational specificity.

RHO-associated protein kinase alpha potentiates insulin-induced MAP kinase activation in Xenopus oocytes

We recently identified Xenopus Rho-associated protein kinase alpha (xROKalpha) as a Xenopus insulin receptor substrate-1 binding protein and demonstrated that the non-catalytic carboxyl terminus of xROKalpha binds Xenopus insulin receptor substrate-1 and blocks insulin-induced MAP kinase activation and germinal vesicle breakdown in Xenopus oocytes. In the current study we further examined the role of xROKalpha in insulin signal transduction in Xenopus oocytes. We demonstrate that injection of mRNA encoding the xROKalpha kinase domain or full length xROKalpha enhanced insulin-induced MAP kinase activation and germinal vesicle breakdown. In contrast, injection of a kinase-dead mutant of xROKalpha or pre-incubation of oocytes with an xROKalpha inhibitor significantly reduced insulin-induced MAP kinase activation. To further dissect the mechanism by which xROKalpha may participate in insulin signalling, we explored a potential function of xROKalpha in regulating cellular Ras function, since insulin-induced MAP kinase activation and germinal vesicle breakdown is known to be a Ras-dependent process. We demonstrate that whereas injection of mRNA encoding c-H-Ras alone induced xMAP kinase activation and GVBD in a very low percentage (about 10%) of injected oocytes, co-injection of mRNA encoding xROKalpha and c-H-Ras induced xMAP kinase activation and germinal vesicle breakdown in a significantly higher percentage (50-60%) of injected oocytes. These results suggest a novel function for xROKalpha in insulin signal transduction upstream of cellular Ras function.

Folate receptor type beta is a neutrophilic lineage marker and is differentially expressed in myeloid leukemia

BACKGROUND

The membrane-associated folate receptor (FR) type beta is elevated in the spleen in patients with chronic myeloid leukemia (CML) and acute myeloid leukemia (AML). In this study, the authors investigated possible cell type and differentiation stage specificity of expression of FR-beta in normal and leukemic hematopoietic cells.

METHODS

An affinity-purified rabbit polyclonal antibody specific for FR-beta was employed for immunostaining representative bone marrow smears and peripheral blood smears from normal individuals and from a limited number of patients with various leukemias. Multiple samples of normal bone marrow and peripheral blood were analyzed for the expression of FR-beta and selected CD antigens by two- or three-color flow cytometry.

RESULTS

Of the morphologically identifiable cells, only neutrophils were positive for FR-beta. The leukemic blasts in CML patients showed expression of FR-beta with no apparent relation to the occurrence of the Philadelphia chromosome. Among acute nonlymphocytic leukemias, FR-beta was expressed in promyelocytic leukemia, in the myeloblast populations of myelomonocytic and erythroleukemias, and variably in M1/M2 AML. Neither the blasts of acute lymphocytic leukemia nor the more mature cells of chronic lymphocytic and hairy cell leukemias expressed FR-beta. The less differentiated FR-beta positive AML samples also were positive for CD34 and HLA-DR. Flow cytometric analysis of normal bone marrow and peripheral blood revealed low or insignificant coexpression of FR-beta with CD34, CD19, and CD3, whereas significant coexpression was observed with high levels of CD33, CD13, and CD11b; coexpression of FR-beta with CD14 was high in the immature bone marrow cells, comparable to that in myeloid cells, but relatively low in peripheral blood.

CONCLUSIONS

The results of this study suggest a narrow expression pattern of FR-beta marking the neutrophilic lineage and the possibility of defining a subtype or subtypes of myeloid leukemia based on FR-beta expression. The identification of FR-beta positive leukemias and the absence of the receptor in normal CD34 positive cells may enable selective receptor-mediated targeting of leukemic cells.

Sex partners of Native American drug users

This study describes patterns of sexual behavior and condom use in a sample of Native American drug-using men and women (N = 114). Data are self-reports of sexual behavior in the last 30 days, including descriptions of the most recent sex partners up to five. These data provided information on 157 sex partner pairs, of which at least one partner was a drug user. Native American women (55%) were more likely than Native American men (23%) to report never using condoms for vaginal and anal sex in the last 30 days. Compared with other ethnic pair combinations, sex partner pairs composed of Native American women and white men (n = 18) were the least likely to use condoms (6% of pairs) and the most likely to report an injection drug user (IDU) sex partner (33% of pairs). These results suggest a potential vector of HIV and other sexually transmitted disease (STD) transmission between white male IDUs and Native American women and highlight the need for further qualitative and quantitative research to examine the factors underlying this pattern of sexual risk behavior.

The mutational specificity of 1-nitroso-6-nitropyrene in the lacI gene of Escherichia coli strains deficient in nucleotide excision repair

We have examined the mutational specificity of 1-nitroso-6-nitropyrene (1,6-NONP), an activated metabolite of the carcinogen 1,6-dinitropyrene, in the lacI gene of Escherichia coli strains which are deficient in nucleotide excision repair (strain NR6113, delta uvrB; strain CM6114, delta uvrB, plasmid pKM101). Separate collections of lacI- mutations and dominant lacI-d mutations, which contain DNA sequence alterations in the region of the lacI gene that encodes the DNA binding domain of the lacI repressor, were made following 1,6-NONP treatment. The DNA sequence of 418 mutations was determined, of which 228 were lacI- mutations and 190 were lacI-d mutations. Ninety three percent of the induced point mutations occurred at G:C residues.0 -(G:C) frameshifts were the dominant mutational class in the lacI- collections of both NR6113 and CM6114, and in the lacI-d collection of NR6113. The frameshift mutations occurred preferentially in runs of guanine residues and their frequency increased markedly with the length of the reiterated sequence. In strain CM6114, which contained the plasmid pKM101, there was a marked stimulation in the frequency of G:C-->T:A transversions that was particularly apparent in the lacI-d collection. We discuss models which might account for the apparent differences in mutational specificity resulting from the presence of the UmuD/C and MucA/B proteins. The results suggest that major classes of mutation are recovered in both the lacI- and lacI-d collections. However, the proportions of the major classes of mutations within the two collections can differ significantly. Depending on the genetic background of the host strain, the relative ratios of base substitutions to frameshift mutations in the lacI-d target can differ by almost an order of magnitude as compared with the lacI- target. This is primarily a function of the relative mutational target size of the different classes of mutation.

Behavioral phenomenology in Alzheimer's disease, frontotemporal dementia, and late-life depression: a retrospective analysis

Often patients in the early stages of Alzheimer's disease (AD), frontotemporal dementia (FTD), and late-life depression can be difficult to differentiate clinically. Although subtle cognitive distinctions exist between these disorders, noncognitive behavioral phenomenology may provide additional discriminating power. In 19 subjects with AD, 19 with FTD, 16 with late-life psychotic depression (LLPD), and 19 with late-life nonpsychotic depression (LLNPD), noncognitive behavioral symptoms were quantified retrospectively using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) and compared using both a one-way ANOVA and a multivariate stepwise discriminant analysis, which utilized a jackknife procedure. The FTD group showed the highest mean total SCAN score, while the AD group showed the lowest. ANOVA showed significant differences in the mean total SCAN scores between the four diagnostic groups (P < .0001). With the discriminant analysis, the four disorders demonstrated different clusters of behavioral abnormalities and were differentiated by these symptoms (P < .0001). A subset of 14 SCAN item group symptoms was identified that collectively classified the following percentages of subjects in each diagnostic category: AD 94.7%, FTD 100%, LLPD 87.5%, and LLNPD 100%. These results indicate that AD, FTD, LLPD, and LLNPD were distinguished retrospectively by the SCAN without using cognitive data. Better definition of the longitudinal course of noncognitive behavioral symptoms in different dementias and psychiatric disorders will be valuable both for diagnosis and to help define behavioral syndromes that are associated with selective neuroanatomic and neurochemical brain pathology.

Bilateral tibial marrow ablation in rats induces a rapid hypercalcemia arising from extratibial bone resorption inhibitable by methylprednisolone or deflazacort

The goals of this study were to quantitate biochemical markers of bone metabolism on days 1-15 after bilateral tibial marrow ablation surgery in young adult rats and to determine the effect of a single dose of methylprednisolone (2 mg/kg) or deflazacort (2.5 mg/kg) given at the time of ablation. Unexpectedly, serum calcium levels rose to a maximum of 15.9 mg/dl on day 7 after marrow ablation and remained above normal through day 15. This increase was blocked by a single intramedullary injection of methylprednisolone or deflazacort immediately following ablation; however, the fact that both drugs produced a characteristic rapid 3- to 10-fold increase in the serum alpha 2-macroglobulin level demonstrates that the drugs rapidly reached the circulation. Both methylprednisolone and deflazacort also inhibited intramedullary deposition of collagen by 40-60% on day 7, a time near which operated control animals achieved maximal accumulation of new bone in this model. Histological comparisons among the three experimental groups were largely consistent with biochemical results. The urinary hydroxyproline/creatine ratio for the operated control group doubled on day 3 and then returned to presurgical levels on day 7 and later. The timing and size of the hydroxyproline/creatinine peak, as well as the fact that the intratibial osteoclastic response peaks on days 8-10 after ablation, suggests it results from extratibial bone resorption induced by marrow ablation. Consistent with this rationale, urinary calcium excretion in operated controls rose 9-fold from day 0 to day 3 and appeared to plateau over the period from day 3 to day 9, before returning to a near presurgical level on day 15. Elevated excretion of calcium noted on days 9-15 in deflazacort-treated animals, which occurs in the absence of a detectable increase in resorption marker hydroxyproline, may however be due to the known action of glucocorticoids in increasing kidney filtration of calcium. In summary, this is the first report to show that bilateral tibial marrow ablation in rats causes a rapid hypercalcemia and calciuria which is accompanied initially by a peak of bone resorption marker urinary hydroxyproline. We speculate that the source of calcium and hydroxyproline is extratibial osteoclastic bone resorption induced by circulating cytokines whose release from ablated tibias or osteoclastogenic action is inhibitable by methylprednisolone and deflazacort.

Assessing reading level of drug users for HIV and AIDS prevention purposes

Using the short form of the Woodcock Reading Mastery Test-Revised and the reading subtest of the Wide Range Achievement Test-Revised, the reading abilities of 284 male and 128 female drug users from five sites across the United States were evaluated. All subjects were participants in a National Institute on Drug Abuse HIV/AIDS prevention project aimed at intravenous drug users and cocaine smokers. Results revealed differences in reading abilities among ethnic groups with Native and white subjects having significantly higher reading levels than Hispanic and black subjects. Significant site differences were revealed, with mean grade equivalent scores ranging from 2.7 to 10.1 grades. Across all subjects, the average grade equivalent reading level was 5.8 to 7.7, indicating that the subjects read below the level of 81.5% to 93% of the general population. We provide implications for development of educational materials that are accessible for this population.

In vivo 1H MRS choline: correlation with in vitro chemistry/histology

We correlated the in vivo 1H Magnetic Resonance Spectroscopy (MRS) concentration of the choline peak (CHO) with in vitro chemical measures of choline-containing compounds and a histological grade of cellularity in 18 patients with neoplastic and infectious brain lesions. Gas-chromatography-mass-spectrometry (GCMS) was used to measure the concentrations of free choline (Cho), glycerophosphocholine (GPCho), phosphocholine (PCho) and phosphatidylcholine (PtdCho) from biopsies in the same area where MRS was performed. Cellular density, free Cho, PCho and GPCho were the strongest determinants of 1H MRS CHO while PtdCho was not. Just as the 1H MRS 2.0 peak reflects both the concentration of n-acetyl-l-aspartate and neuronal density, the 1H MRS 3.2 peak reflects the concentration of water-soluble choline-containing compounds and cellular density.

Eastern barred bandicoot recovery: the role of the veterinarian in the management of endangered species

The eastern barred bandicoot, Perameles gunnii, formerly widespread on the volcanic plains of western Victoria, has been reduced to a single, rapidly-declining, remnant population at Hamilton. Recovery of this critically endangered species has included local management, in an attempt to stabilise the wild population, captive breeding and reintroduction to selected sites. Veterinary advice and assistance have been an integral part of the investigation, planning and implementation phases of the program. The development of appropriate, standardised techniques has enabled successful treatment of problems in the captive colony. Husbandry, including the hand-rearing of pouch young has been refined. Parasitism, identified as a contributor to poor health or death, has been investigated. Experimental development of techniques for the attachment of radio-transmitters to bandicoots has enabled improved field research to take place. Fox predation, a major limiting factor in the recovery program, has been studied in detail, in order to refine control protocols.

Phospholipids in meibomian gland secretion

The bulk of the lipid layer overlying the aqueous portion of the precorneal tear film is composed of polar and nonpolar components. The nonpolar lipids have been the subject of numerous studies; however, the polar lipids have remained relatively uncharacterized. The polar lipids are thought to contain surfactant phospholipids that are critical to the spreading of a lipid film over the aqueous layer, by providing an interface between this layer and the nonpolar lipids. The purpose of the present study is to identify and quantitate the phospholipid complement of meibomian gland secretion which provides the tear film with phospholipids. Meibomian gland secretion was collected from rabbits and phospholipids identified and quantitated by 31P nuclear magnetic resonance spectroscopy. Ten phospholipids were detected from meibomian gland secretion: diphosphatidylglycerol, dihydrosphingomyelin, ethanolamine plasmalogen, phosphatidylethanolamine (PE), phosphatidylserine, sphingomyelin, lysophosphatidylcholine, phosphatidylinositol, alkylacylphosphatidylcholine, and phosphatidylcholine (PC). The two major phospholipids were PC and PE, together comprising nearly 60% of the total phospholipid profile. The nature and relative concentrations of the meibomian gland secretion phospholipids are congruous with a surfactant role at the aqueous-lipid interface and, considering the physical chemistry of the tear film, suggest that the phospholipids should be organized in a very flat or planar configuration.

Women living with drug abuse and HIV disease: drug abuse treatment access and secondary prevention issues

In collaboration with the National Institute on Drug Abuse, the Health Resources and Services Administration is conducting a multisite, longitudinal study on issues of service needs, service utilization, and access to care for drug abusers with HIV. This article discusses access to drug abuse treatment and HIV secondary prevention for 116 women interviewed during the study's first year in five U.S. cities. Using interview data from 115 service providers in those same cities, it also discusses drug abuse treatment availability and barriers to service expansion for drug users with HIV. Study findings indicate that there are highly significant gaps between the drug abuse treatment services these women feel they need and those they have been able to receive; these were particularly pronounced for drug detoxification and residential and outpatient drug-free treatment. Women who used crack cocaine or injection drugs had particularly high levels of need for residential and outpatient drug abuse treatment, while women who use crack were found to have significantly less experience with the drug abuse treatment system than IDUs. HIV secondary prevention was also found to be a critical need for these women, many of whom were engaging in behaviors that place them at risk for reinfection, infection with other diseases, and transmission to others. Providers indicated that lack of funding was the major barrier to expanding services for this population; other barriers, such as lack of ancillary services and transportation, were also noted. Two positive findings were that many drug abuse treatment agencies in these cities provide a wide range of ancillary services and that many different kinds of agencies offer drug abuse treatment services.

Women living with substance abuse and HIV disease: medical care access issues

This paper presents first-year findings from a multi-site, longitudinal study being coordinated by the Health Resources and Services Administration (HRSA) in collaboration with the National Institute on Drug Abuse (NIDA) on access to care for drug abusers with HIV. The sample of 116 women and 187 men in five sites (Denver, Detroit, New Haven, New Orleans, and St. Louis) were interviewed regarding HIV testing history, HIV disease course, and use of health and social services. For both men and women, there were significant gaps between the medical services they reported needing and those they received. Significantly more women needed and received mental health services. Cost and waiting times emerged as the most important barriers to care. The study also found that significantly fewer women than men subjects received pre- and post-test counseling and were advised to get medical services after their first positive HIV test. Overall, first-year study results suggest that multiple barriers in access to service exist for drug-using women, the largest group of women affected by HIV in the United States.