Do contaminants compromise the use of recycled nutrients in organic agriculture? A review and synthesis of current knowledge on contaminant concentrations, fate in the environment and risk assessment

Use of nutrients recycled from societal waste streams in agriculture is part of the circular economy, and in line with organic farming principles. Nevertheless, diverse contaminants in waste streams create doubts among organic farmers about potential risks for soil health. Here, we gather the current knowledge on contaminant levels in waste streams and recycled nutrient sources, and discuss associated risks. For potentially toxic elements (PTEs), the input of zinc (Zn) and copper (Cu) from mineral feed supplements remains of concern, while concentrations of PTEs in many waste streams have decreased substantially in Europe. The same applies to organic contaminants, although new chemical groups such as flame retardants are of emerging concern and globally contamination levels differ strongly. Compared to inorganic fertilizers, application of organic fertilizers derived from human or animal feces is associated with an increased risk for environmental dissemination of antibiotic resistance. The risk depends on the quality of the organic fertilizers, which varies between geographical regions, but farmland application of sewage sludge appears to be a safe practice as shown by some studies (e.g. from Sweden). Microplastic concentrations in agricultural soils show a wide spread and our understanding of its toxicity is limited, hampering a sound risk assessment. Methods for assessing public health risks for organic contaminants must include emerging contaminants and potential interactions of multiple compounds. Evidence from long-term field experiments suggests that soils may be more resilient and capable to degrade or stabilize pollutants than often assumed. In view of the need to source nutrients for expanding areas under organic farming, we discuss inputs originating from conventional farms vs. non-agricultural (i.e. societal) inputs. Closing nutrient cycles between agriculture and society is feasible in many cases, without being compromised by contaminants, and should be enhanced, aided by improved source control, waste treatment and sound risk assessments.

Caloric restriction in humans reveals immunometabolic regulators of health span

The extension of life span driven by 40% caloric restriction (CR) in rodents causes trade-offs in growth, reproduction, and immune defense that make it difficult to identify therapeutically relevant CR-mimetic targets. We report that about 14% CR for 2 years in healthy humans improved thymopoiesis and was correlated with mobilization of intrathymic ectopic lipid. CR-induced transcriptional reprogramming in adipose tissue implicated pathways regulating mitochondrial bioenergetics, anti-inflammatory responses, and longevity. Expression of the gene Pla2g7 encoding platelet activating factor acetyl hydrolase (PLA2G7) is inhibited in humans undergoing CR. Deletion of Pla2g7 in mice showed decreased thymic lipoatrophy, protection against age-related inflammation, lowered NLRP3 inflammasome activation, and improved metabolic health. Therefore, the reduction of PLA2G7 may mediate the immunometabolic effects of CR and could potentially be harnessed to lower inflammation and extend the health span.

Mindfulness-based stress reduction improves irritable bowel syndrome (IBS) symptoms via specific aspects of mindfulness

BACKGROUND

Irritable bowel syndrome (IBS) is a common and often debilitating chronic gastrointestinal disorder characterized by abdominal pain and altered bowel habits. Pharmacological treatments are often ineffective, leading to the development of a variety of behavioral interventions. Mindfulness-based stress reduction (MBSR) is one such program that has shown efficacy in reducing gastrointestinal (GI) symptoms and improving quality of life (QOL). This single-arm intervention study examines the association of clinical outcomes with changes in specific aspects of mindfulness.

METHODS

Adults with IBS (53 women, 15 men) participated in an 8-week MBSR class. Primary outcomes of GI symptom severity, quality of life, and GI-specific anxiety, as well as specific aspects of mindfulness using the Five Factor Mindfulness Questionnaire (FFMQ), were assessed at baseline, post-treatment, and 6-month follow-up.

KEY RESULTS

Gastrointestinal symptom responder rate was 71%, and there was a significant pre-post treatment change for three of the five FFMQ scales. Regression analysis indicated that change in the Act with Awareness (P = .02) facet of mindfulness was the strongest predictor of GI symptom and QOL improvement.

CONCLUSIONS & INFERENCES

Mindfulness-based stress reduction training was associated with robust improvements in GI symptoms and associated problems in participants with IBS. Although significant increases in 3 of the 5 measured facets of mindfulness were found, regression analyses suggest that increases in the ability to retain present moment focus and act with awareness may be particularly important for improving outcomes in individuals with IBS. These results may inform the refinement of mindfulness-based protocols specifically for treatment of IBS.

C-reactive protein trajectory to predict colorectal anastomotic leak: PREDICT Study

BACKGROUND

Anastomotic leak is a common complication after colorectal surgery, associated with increased morbidity and mortality, and poorer long-term survival after oncological resections. Early diagnosis improves short-term outcomes, and may translate into reduced cancer recurrence. Multiple studies have attempted to identify biomarkers to enable earlier diagnosis of anastomotic leak. One study demonstrated that the trajectory of C-reactive protein (CRP) levels was highly predictive of anastomotic leak requiring intervention, with an area under the curve of 0·961. The aim of the present study was to validate this finding externally.

METHODS

This was a prospective international multicentre observational study of adults undergoing elective colorectal resection with an anastomosis. CRP levels were measured before operation and for 5 days afterwards, or until day of discharge if earlier than this. The primary outcome was anastomotic leak requiring operative or radiological intervention.

RESULTS

Between March 2017 and July 2018, 933 patients were recruited from 20 hospitals across Australia, New Zealand, England and Scotland. Some 833 patients had complete CRP data and were included in the primary analysis, of whom 41 (4·9 per cent) developed an anastomotic leak. A change in CRP level exceeding 50 mg/l between any two postoperative days had a sensitivity of 0·85 for detecting a leak, and a high negative predictive value of 0·99 for ruling it out. A change in CRP concentration of more than 50 mg/l between either days 3 and 4 or days 4 and 5 after surgery had a high specificity of 0·96-0·97, with positive likelihood ratios of 4·99-6·44 for a leak requiring intervention.

CONCLUSION

This study confirmed the value of CRP trajectory in accurately ruling out an anastomotic leak after colorectal resection.

The LAPLAP study: a randomized placebo-controlled clinical trial assessing postoperative functional recovery using intraperitoneal local anaesthetic in laparoscopic colorectal surgery

AIM

Postoperative pain remains a major factor in recovery from colorectal resection. There is increasing interest in opioid-sparing analgesia, and intraperitoneal local anaesthetic (IPLA) has recently been shown to be useful in minor laparoscopic and open colorectal procedures. The aim of this study was to evaluate the impact of IPLA on functional recovery following major laparoscopic surgery. In this controlled trial, mobility, as measured by the De Morton Mobility Index (DEMMI), was used as a surrogate for postoperative functional recovery.

METHOD

Patients undergoing laparoscopic colorectal resection were randomized either to continuous ropivacaine (0.2% at 4-6 ml/h) or to saline (0.9%) which were administered via intraperitoneal catheter for 3 days postoperatively. Results were analysed in a double-blind manner. DEMMIs were assessed on postoperative days 1, 2, 3, 7 and 30, and data on pain, opioid consumption, gut and respiratory function, length of stay (LOS) and complications were recorded.

RESULTS

Ninety-six patients were recruited. There was no difference in primary outcome (i.e., functional recovery) between IPLA and placebo groups. Opioid consumption and LOS were similar between groups, and no differences were found for any secondary outcome measure. There were no adverse events related to ropivacaine.

CONCLUSION

Infusional intraperitoneal local anaesthetic appears to be safe but does not improve functional recovery or analgesic consumption following elective laparoscopic colorectal surgery, in the setting of an established enhanced recovery programme.

Manchester Arena bombing: lessons learnt from a mass casualty incident

On 22 May 2017 Salman Abedi detonated an improvised explosive device in the Manchester Arena resulting in 23 deaths (including the attacker). This was the deadliest terrorist attack on UK soil since the 2005 London bombings, but was only one of five mass casualty terrorist attacks in the UK in 2017. Preparation for mass casualty incidents (MCI) is obligatory, involving such methods as multiagency tabletop exercises, mock hospital exercises, as well as simulation and training for clinicians in managing the injuries that would be anticipated in such an event. Even in the best prepared units, such an incident will pose significant challenges due to the unpredictable nature of these events with respect to timing and number of casualties. Following an MCI, local and national reviews are undertaken to assess the effectiveness of the response, but also to identify areas where lessons can be learnt and to disseminate these to allow inclusion in future planning. We present the experience following a mass casualty terrorist incident along with a number of lessons learnt from this event.

Verification of an alternative sludge treatment process for pathogen reduction at two wastewater treatment plants in Victoria, Australia

At South East Water wastewater treatment plants (WwTPs) in Victoria, Australia, biosolids are stockpiled for three years in compliance with the State guidelines to achieve the highest pathogen reduction grade (T1), suitable for unrestricted use in agriculture and landscaping. However, extended stockpiling is costly, may increase odour nuisance and greenhouse gas emissions, and reduces the fertiliser value of the biosolids. A verification programme of sampling and analysis for enteric pathogens was conducted at two WwTPs where sludge is treated by aerobic and anaerobic digestion, air drying (in drying pans or solar drying sheds) and stockpiling, to enumerate and, if present, monitor the decay of a range of enteric pathogens and parasites. The sludge treatment processes at both WwTPs achieved T1 grade biosolids with respect to prescribed pathogenic bacterial numbers (<1 Salmonella spp. 50 g^-1 dry solids (DS) and <100 Escherichia coli g^-1 DS) and >3 log₁₀ enteric virus reduction after a storage period of one year. No Ascaris eggs were detected in the influent to the WwTPs, confirming previous studies that the presence of helminth infections in Victoria is extremely low and that Ascaris is not applicable as a control criterion for the microbiological quality of biosolids in the region.

Teaching University Students About Evidence-Based Perinatal Care: Effects on Learning and Future Care Preferences

U.S. university students hold generally medicalized views on childbirth, which contrast with evidence indicating that low-intervention birth is safest for most. Therefore, intentional efforts are needed to educate childbearing populations on perinatal care evidence. Toward that aim, this study involved teaching university students in an introductory class (N = 50) about evidence-based perinatal care. Students completed a "future birth plan" and an essay on how their learning affected care preferences. Analyses revealed that students selected evidence-based care components up to 100 times more frequently than what the national data indicate they are used. Students based care selections on evidence, costs, and personal views. Their interest in physiologic birth has important implications for advancing education on perinatal care, practice, and policy.

Potential Modern Alternative Designs for Caries Clinical Trials (CCTs) and How These can be Validated against the Conventional Model

The main reasons that industry runs caries clinical trials (CCTs) are to provide proof of efficacy and to collect in vivo safety data on new products. In recent years, predominantly due to declining caries levels and the use of positive controls, the cost of performing these CCTs has escalated. It is now reaching the stage where it is becoming commercially prohibitive to conduct new studies. This is likely to stifle innovation of new anticaries products, and we now need new, more discriminatory, faster, and less expensive study designs. There are many ways in which the design of CCTs may be changed, such as improving diagnostic efficiency, improving data handling/statistical modeling, and using high-risk populations. However, it is paramount that the overriding principle behind CCT design validation must be that the results/conclusions from any new design are in line with those shown previously by ‘conventional’ CCTs, to ensure the maintenance of standards for both efficacy and safety. It is suggested that the validation of any new trial design must involve comparisons with regimens previously shown in conventional CCTs to have different anticaries efficacies. For example, since several clinical trials have shown convincing evidence for a monotonic dose response for fluoride at least up to levels of 2500 ppm F, one could choose two products, differing solely in their fluoride level. One aim for this workshop is to identify and agree on validation principles for new clinical trial designs. This will facilitate general international acceptance of novel smaller/faster CCTs designs both now and in the future. We recognize that any new design must not compromise the standard of proof of either efficacy or safety. In addition, any principles will need to take account of current understanding of the caries process, while recognizing the need for change to match future developments in cariology. Finally, the mechanism of action of the test product must be considered, in assessments of the acceptability of novel designs, if this differs markedly from the regimens used to validate the design.

The Challenges of Validating Diagnostic Methods Relative to a Conventional Two-year Caries Clinical Trial

This paper is directed to the question, “What are the appropriate validation criteria for the use of a new clinical trial methodology as a replacement for a conventional two- to three-year caries study?” It is important to recognize that the objective of a two- to three-year randomized, controlled caries trial is to test a precisely framed hypothesis, regarding an experimental product's efficacy relative to a control product. The external validity of conventional two- to three-year caries clinical studies in determining the efficacy and safety of anti-caries products is well-accepted. However, caries clinical trials are not without limitations and have increasingly been viewed as inefficient with respect to measuring the disease process in a holistic manner. The endpoint of a caries lesion with loss of enamel integrity (cavitation) focuses on one end of the caries progression continuum at the expense of early caries initiation and progression. Several early caries detection methods have been developed that correlate with mineral loss of the tooth surface. These diagnostics differ from conventional visual-tactile and radiographic methods in that they are capable of detecting early non-cavitated lesions, and this can generate continuous data. As diagnostic methods become accepted, they will lead to study designs that diverge from the conventional two- to three-year caries studies. Modification of the existing two- to three-year conventional caries design for assessment of product effectiveness, whether by the introduction of a new diagnostic method or by modification of the overall clinical design, must result in a clinical design that is able to differentiate known treatments on the basis of caries prevention efficacy. Given that the fluoride dose response has been characterized in the literature, this should form the basis of any validation package for new methodologies. In conclusion, a minimum expectation for acceptance as a replacement to conventional testing should be that the method or design can differentiate products of known efficacy from one another and that the efficacy relationship observed in a two- to three-year conventional study can be observed with the new method or design.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Multicentre observational study of outcomes after drainage of acute perianal abscess

Introduction

Management of perianal abscesses has remained largely unchanged for over 50 years. The evidence for postoperative wound packing is limited and may expose patients to painful procedures with no clinical benefit and at considerable increased cost.

Methods

Patients were recruited in 15 UK centres between December 2013 and October 2014. Outcome measures included number of dressing (pack) changes, healing, recurrence, return to work/normal function, postoperative fistula in ano and health utility scores (EQ-5D™). Pain was measured before, during and after dressing change on a visual analogue scale.

Results

Some 141 patients were recruited (median age 39 (range 18–86) years). The mean number of dressing changes in the first 3 weeks was 13 (range 0–21), equating to an annual cost to the National Health Service of €6 453 360 in England alone per annum. Some 43·8 per cent of wounds were healed by 8 weeks after surgery and 86 per cent of patients had returned to normal function. Some 7·6 per cent of abscesses had recurred and 26·7 per cent of patients developed a fistula in ano by 6 months following surgery. Patients reported a twofold to threefold increase in pain scores during and after dressing changes.

Conclusion

Recurrent abscess is rare and fistula occurs in one-quarter of the patients. Packing is painful and costly.

Emergency General Surgery: evolution of a subspecialty by stealth

BACKGROUND

Emergency surgical patients account for around half of all NHS surgical workload and 80 % of surgical deaths. Few trainees opt to CCT in General Surgery, and there is no recognised subspecialty training program in Emergency General Surgery (EGS). Despite this lack of training and relevant assessment by examination, there appears to be an increasing number of EGS posts advertised. This study aims to provide information about potential future employment opportunities for surgical trainees.

METHODS

All consultant surgeon posts, advertised in the British Medical Journal between January 2009 and December 2014 were included. Data collected included specialty, region and institute of advertised post. For the purposes of statistical analysis, data was divided into two separate year bands: 2009-2011 and 2012-2014. Statistical analysis was by Chi-squared test; p <0.01 was considered statistically significant. An online tool was also used to determine experience and attitudes towards EGS amongst Consultant members of the ASGBI and all UK trainees in national training number (NTN) posts.

RESULTS

Over the six-year study period, there were 1240 consultant job adverts in a general surgical specialty. Nine hundred and 75 were substantive posts; the region with the most jobs was London and the South East (n = 278). There were 55 jobs advertised in EGS, either with (20) or without (35) another subspecialty. The number of EGS adverts increased significantly in 2012-14 compared to 2009-11 (p = 0.008). 229 (28 %) Consultants and 309 (22 %) trainees responded to the survey. 16 % of consultants work in NHS institutions with Emergency General Surgeons. Only 21 % of trainees believe EGS will be delivered by EGS consultants in the future whilst 8.2 % of trainees stated EGS as their career plan. Less than half of all UK consultant surgeons see EGS as a subspecialty.

CONCLUSIONS

This data demonstrates increasing societal need for EGS consultants over the last six years and the emergence of Emergency Surgery as a new subspecialty. In order to meet the EGS needs of the NHS, general surgical training and the examination system need to be revised.

Altered brain responses in subjects with irritable bowel syndrome during cued and uncued pain expectation

BACKGROUND

A majority of the subjects with irritable bowel syndrome (IBS) show increased behavioral and brain responses to expected and delivered aversive visceral stimuli during controlled rectal balloon distension, and during palpation of the sigmoid colon. We aimed to determine if altered brain responses to cued and uncued pain expectation are also seen in the context of a noxious somatic pain stimulus applied to the same dermatome as the sigmoid colon.

METHODS

A task-dependent functional magnetic resonance imaging technique was used to investigate the brain activity of 37 healthy controls (18 females) and 37 IBS subjects (21 females) during: (i) a cued expectation of an electric shock to the abdomen vs a cued safe condition; and (ii) an uncued cross-hair condition in which the threat is primarily based on context vs a cued safe condition.

KEY RESULTS

Regions within the salience, attention, default mode, and emotional arousal networks were more activated by the cued abdominal threat condition and the uncued condition than in the cued safe condition. During the uncued condition contrasted to the cued safe condition, IBS subjects (compared to healthy control subjects) showed greater brain activations in the affective (amygdala, anterior insula) and attentional (middle frontal gyrus) regions, and in the thalamus and precuneus. These disease-related differences were primarily seen in female subjects.

CONCLUSIONS & INFERENCES

The observed greater engagement of cognitive and emotional brain networks in IBS subjects during contextual threat may reflect the propensity of IBS subjects to overestimate the likelihood and severity of future abdominal pain.

Placebo analgesia: Self-report measures and preliminary evidence of cortical dopamine release associated with placebo response

Placebo analgesia is measured by self-report, yet current, expected, and recalled efficacy may be differentially related to brain function. Here we used a human thermal pain model to compare self-reports of expected, concurrent, and recalled efficacy of a topical placebo analgesic, and tested associations of the three measures of efficacy with changes in dopamine D2/D3 receptor availability in brain using [¹⁸F]fallypride with positron emission tomography (PET). Participants (15 healthy women) were assessed on three test days. The first test day included a laboratory visit, during which the temperature needed to evoke consistent pain was determined, placebo analgesia was induced via verbal and experience-based expectation, and the placebo response was measured. On two subsequent test days, PET scans were performed in Control and Placebo conditions, respectively, in counterbalanced order. During Visit 1, concurrent and recalled placebo efficacy were unrelated; during the Placebo PET visit, expected and recalled efficacy were highly correlated (ρ = 0.68, p = 0.005), but concurrent efficacy was unrelated to expected or recalled efficacy. Region of interest analysis revealed dopamine D2/D3 receptor availability was lower in left ventrolateral prefrontal cortex in the Placebo condition (p < 0.001, uncorrected), and greater change in this measure was associated with higher levels of recalled analgesic efficacy (ρ = 0.58, p = 0.02). These preliminary findings underscore the need to consider how self-reported symptom improvement is assessed in clinical trials of analgesics and suggest that dopaminergic activity in the ventrolateral prefrontal cortex may promote recalled efficacy of placebo.

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Healthy women reported on expected, concurrent, and recalled placebo analgesia.

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Measures were obtained in the lab and during PET scanning with [¹⁸F]fallypride.

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Dopamine D2/D3 receptor availability in PFC was associated with placebo analgesia.

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This relationship was specific to recalled placebo analgesia efficacy.

Defining our destiny: trainee working group consensus statement on the future of emergency surgery training in the United Kingdom

The United Kingdom National Health Service treats both elective and emergency patients and seeks to provide high quality care, free at the point of delivery. Equal numbers of emergency and elective general surgical procedures are performed, yet surgical training prioritisation and organisation of NHS institutions is predicated upon elective care. The increasing ratio of emergency general surgery consultant posts compared to traditional sub-specialities has yet to be addressed. How should the capability gap be bridged to equip motivated, skilled surgeons of the future to deliver a high standard of emergency surgical care? The aim was to address both training requirements for the acquisition of necessary emergency general surgery skills, and the formation of job plans for trainee and consultant posts to meet the current and future requirements of the NHS.

Twenty nine trainees and a consultant emergency general surgeon convened as a Working Group at The Association of Surgeons in Training Conference, 2015, to generate a united consensus statement to the training requirement and delivery of emergency general surgery provision by future general surgeons. Unscheduled general surgical care provision, emergency general surgery, trauma competence, training to meet NHS requirements, consultant job planning and future training challenges arose as key themes. Recommendations have been made from these themes in light of published evidence. Careful workforce planning, education, training and fellowship opportunities will provide well-trained enthusiastic individuals to meet public and societal need.

Nitrogen availability and indirect measurements of greenhouse gas emissions from aerobic and anaerobic biowaste digestates applied to agricultural soils

Recycling biowaste digestates on agricultural land diverts biodegradable waste from landfill disposal and represents a sustainable source of nutrients and organic matter (OM) to improve soil for crop production. However, the dynamics of nitrogen (N) release from these organic N sources must be determined to optimise their fertiliser value and management. This laboratory incubation experiment examined the effects of digestate type (aerobic and anaerobic), waste type (industrial, agricultural and municipal solid waste or sewage sludge) and soil type (sandy loam, sandy silt loam and silty clay) on N availability in digestate-amended soils and also quantified the extent and significance of the immobilisation of N within the soil microbial biomass, as a possible regulatory mechanism of N release. The digestate types examined included: dewatered, anaerobically digested biosolids (DMAD); dewatered, anaerobic mesophilic digestate from the organic fraction of municipal solid waste (DMADMSW); liquid, anaerobic co-digestate of food and animal slurry (LcoMAD) and liquid, thermophilic aerobic digestate of food waste (LTAD). Ammonium chloride (NH4Cl) was included as a reference treatment for mineral N. After 48 days, the final, maximum net recoveries of mineral N relative to the total N (TN) addition in the different digestates and unamended control treatments were in the decreasing order: LcoMAD, 68%; LTAD, 37%, DMAD, 20%; and DMADMSW, 11%. A transient increase in microbial biomass N (MBN) was observed with LTAD application, indicating greater microbial activity in amended soil and reflecting the lower stability of this OM source, compared to the other, anaerobic digestate types, which showed no consistent effects on MBN compared to the control. Thus, the overall net release of digestate N in different soil types was not regulated by N transfer into the soil microbial biomass, but was determined primarily by digestate properties and the capacity of the soil type to process and turnover digestate N. In contrast to the sandy soil types, where nitrate (NO3-) concentrations increased during incubation, there was an absence of NO3- accumulation in the silty clay soil amended with LTAD and DMADMSW. This provided indirect evidence for denitrification activity and the gaseous loss of N, and the associated increased risk of greenhouse gas emissions under certain conditions of labile C supply and/or digestate physical structure in fine-textured soil types. The significance and influence of the interaction between soil type and digestate stability and physical properties on denitrification processes in digestate-amended soils require urgent investigation to ensure management practices are appropriate to minimise greenhouse gas emissions from land applied biowastes.

Effect of pioglitazone on body composition and bone density in subjects with prediabetes in the ACT NOW trial

AIMS

This study examined the effects of pioglitazone on body weight and bone mineral density (BMD) prospectively in patients with impaired glucose tolerance as pioglitazone (TZD) increases body weight and body fat in diabetic patients and increases the risk of bone fractures.

METHODS

A total of 71 men and 163 women aged 49.3 (10.7) years [mean (s.d.)]; body mass index (BMI), 34.5 (5.9) kg/m(2) were recruited at five sites for measurements of body composition by dual energy X-ray absorptiometry at baseline and at conversion to diabetes or study end, if they had not converted.

RESULTS

Mean follow-up was 33.6 months in the pioglitazone group and 32.1 months in the placebo group. Body weight increased 4.63 ± 0.60 (m ± s.e.) kg in the pioglitazone group compared to 0.98 ± 0.62 kg in the PIO group (p < 0.0001). Body fat rose 4.89 ± 0.42 kg in the pioglitazone group compared to 1.41 ± 0.44 kg, (p < 0.0001) in placebo-treated subjects. The increase in fat was greater in legs and trunk than in the arms. BMD was higher in all regions in men and significantly so in most. PIO decreased BMD significantly in the pelvis in men and women, decreased BMD in the thoracic spine and ribs of women and the lumbar spine and legs of men. Bone mineral content also decreased significantly in arms, legs, trunk and in the total body.

CONCLUSIONS

Pioglitazone increased peripheral fat more than truncal fat and decreased BMD in several regions of the body.

Combination therapy with naltrexone and bupropion for obesity reduces total and visceral adiposity

The effects of combination naltrexone/bupropion therapy on body composition and visceral adipose tissue (VAT) mass were examined in a subset (n = 107) of obese subjects from a Phase 2 trial that compared the efficacy and safety of placebo, naltrexone monotherapy, bupropion monotherapy or one of three naltrexone/bupropion dose combinations for 24 weeks. Body composition data were obtained using dual-energy X-ray absorptiometry and computed tomography. Eighty subjects completed the substudy. Naltrexone/bupropion resulted in weight loss and a greater reduction in body fat (-14.0 ± 1.3%) than placebo (-4.0 ± 2.0%), naltrexone monotherapy (-3.2 ± 2.5%) and bupropion monotherapy (-4.1 ± 2.9%; all p < 0.01). Reduction in VAT mass was also greater with naltrexone/bupropion (-15.0 ± 1.8%) than placebo (-4.6 ± 2.7%), naltrexone monotherapy (-0.1 ± 3.5%) and bupropion monotherapy (-2.3 ± 4.2%; all p < 0.01). Reductions in body fat and VAT mass with naltrexone/bupropion were proportional with weight loss. Weight loss with naltrexone/bupropion was not associated with a greater relative reduction in lean mass than placebo or the monotherapies.

Remineralization agents - new and effective or just marketing hype?

This is a review of the need for better remineralization and of the status of calcium-based remineralizing agents for use in anti-caries toothpastes. Use of fluoride toothpastes has markedly reduced caries. However, the decline may be over or in reverse. There is a limit to what fluoride alone can do; complementary agents are needed. Using plaque as a reservoir for calcium-based agents holds promise. Plaque fluid is already supersaturated with respect to relevant calcium phosphates at neutral pH; extra calcium may lead to surface-blocking and sub-optimal lesion consolidation. However, at cariogenic pH, lesions may be more porous to the ingress of mineral, leading to fuller consolidation, and controlled release of calcium should reduce undersaturation with respect to enamel and accelerate deposition of fluorhydroxyapatite. Clinical data to validate in vitro screening models are scarce. Direct progression to in situ models may often be appropriate. The spectrum of lesion types, from softening to relatively advanced subsurface, and lesion activity should be considered. Far from being 'marketing hype', progress with calcium-based remineralizing agents is both encouraging and scientifically sound. Clinical evidence exists for the efficacy of some agents, but further unequivocal clinical data are needed before these agents might be considered 'effective' when delivered from toothpaste.

Sarcopenic obesity: A Critical appraisal of the current evidence

Sarcopenic obesity (SO) is assuming a prominent role as a risk factor because of the double metabolic burden derived from low muscle mass (sarcopenia) and excess adiposity (obesity). The increase in obesity prevalence rates in older subjects is of concern given the associated disease risks and more limited therapeutic options available in this age group. This review has two main objectives. The primary objective is to collate results from studies investigating the effects of SO on physical and cardio-metabolic functions. The secondary objective is to evaluate published studies for consistency in methodology, diagnostic criteria, exposure and outcome selection. Large between-study heterogeneity was observed in the application of diagnostic criteria and choice of body composition components for the assessment of SO, which contributes to the inconsistent associations of SO with cardio-metabolic outcomes. We propose a metabolic load:capacity model of SO given by the ratio between fat mass and fat free mass, and discuss how this could be operationalised. The concept of regional fat distribution could be incorporated into the model and tested in future studies to advance our understanding of SO as a predictor of risk for cardio-metabolic diseases and physical disability.

Simple technologies for on-farm composting of cattle slurry solid fraction

Composting technologies and control systems have reached an advanced stage of development, but these are too complex and expensive for most agricultural practitioners for treating livestock slurries. The development of simple, but robust and cost-effective techniques for composting animal slurries is therefore required to realise the potential benefits of waste sanitation and soil improvement associated with composted livestock manures. Cattle slurry solid fraction (SF) was collected at the rates of 4m(3)h(-1) and 1m(3)h(-1) and composted in tall (1.7 m) and short (1.2m) static piles, to evaluate the physicochemical characteristics and nutrient dynamics of SF during composting without addition of bulking agent materials, and without turning or water addition. Highest maximum temperatures (62-64 °C) were measured in tall piles compared to short piles (52 °C). However, maximum rates of organic matter (OM) destruction were observed at mesophilic temperature ranges in short piles, compared to tall piles, whereas thermophilic temperatures in tall piles maximised sanitation and enhanced moisture reduction. Final OM losses were within the range of 520-660 g kg(-1) dry solids and the net loss of OM significantly (P<0.001) increased nutrient concentrations during the composting period. An advanced degree of stabilization of the SF was indicated by low final pile temperatures and C/N ratio, low concentrations of NH(4)(+) and increased concentrations of NO(3)(-) in SF composts. The results indicated that minimum intervention composting of SF in static piles over 168 days can produce agronomically effective organic soil amendments containing significant amounts of OM (772-856 g kg(-1)) and plant nutrients. The implications of a minimal intervention management approach to composting SF on compost pathogen reduction are discussed and possible measures to improve sanitation are suggested.

Effects of saxagliptin on β-cell stimulation and insulin secretion in patients with type 2 diabetes

AIM

To study the effect of dipeptidyl peptidase-4 (DPP-4) inhibition with saxagliptin on β-cell function as reflected by the stimulated insulin secretion rate after an enteral glucose load in patients with type 2 diabetes.

METHODS

Patients in this randomized, parallel-group, double-blind, placebo-controlled study were drug-naïve, aged 43-69 years, with baseline haemoglobin A1c (HbA1c) 5.9-8.1%. Twenty patients received saxagliptin 5 mg once daily; 16 received placebo. Patients were assessed at baseline and week 12 by intravenous hyperglycaemic clamp (0-180 min, fasting state), and intravenous-oral hyperglycaemic clamp (180-480 min, postprandial state) following oral ingestion of 75 g glucose. Primary and secondary endpoints were percent changes from baseline in insulin secretion during postprandial and fasting states, respectively. Insulin secretion was calculated by C-peptide deconvolution.

RESULTS

After 12 weeks, saxagliptin significantly increased insulin secretion percent change from baseline during the postprandial state by an 18.5% adjusted difference versus placebo (p = 0.04), an improvement associated with increased peak plasma concentrations of intact glucagon-like peptide-1 and glucose-dependent insulinotropic polypeptide. In the fasting state, saxagliptin significantly increased insulin secretion by a 27.9% adjusted difference versus placebo (p = 0.02). Saxagliptin also improved glucagon area under the curve in the postprandial state (adjusted difference -21.8% vs. placebo, p = 0.03).

CONCLUSIONS

DPP-4 inhibition with saxagliptin improves pancreatic β-cell function in postprandial and fasting states, and decreases postprandial glucagon concentration. Given the magnitude of enhancement of the insulin response in the fasting state, further study into the effect of DPP-4 inhibition on the β-cell is warranted.

Media formulation options and manufacturing process controls to safeguard against introduction of animal origin contaminants in animal cell culture

Technical limitations and evolution of therapeuticapplications for cell culture-derived products haveaccelerated elimination of animal-derived constituentsto minimize inadvertent introduction of adventitiousviral or prion agents. Practical considerationsdemand adequate emphasis both on design of theserum-free/protein-free culture environment and onnutrient media manufacturing process controls. Protein components may be acceptable, given adequateattention to synthetic process, sourcing (e.g.,geographic location and endemicity, species andtissue/organ) and validated treatment method. Variousoptions exist for re-engineering of traditionalserum-free formulations (containing insulin,transferrin and other protein factors) withnon-protein substitutes. Caution must also beexercised with sourcing of non-protein additives,particularly amino acids and lipids, to avoidintroducing adventitious contaminants. Simpleguidelines facilitate adaptation, cryopreservation andrecovery of many cell types within a protein-freeculture environment. Scrupulous maintenance offacility and equipment and monitoring of processwater, air handling systems and technical personnelare required to ensure that approved raw materials arecorrectly formulated and dispensed. Validatedsanitization processes provide additional assuranceagainst cross-contamination from previous batches ina multi-use facility.

Impact of Mindfulness-Based Stress Reduction training on intrinsic brain connectivity

The beneficial effects of mindful awareness and mindfulness meditation training on physical and psychological health are thought to be mediated in part through changes in underlying brain processes. Functional connectivity MRI (fcMRI) allows identification of functional networks in the brain. It has been used to examine state-dependent activity and is well suited for studying states such as meditation. We applied fcMRI to determine if Mindfulness-Based Stress Reduction (MBSR) training is effective in altering intrinsic connectivity networks (ICNs). Healthy women were randomly assigned to participate in an 8-week Mindfulness-Based Stress Reduction (MBSR) training course or an 8-week waiting period. After 8 weeks, fMRI data (1.5T) was acquired while subjects rested with eyes closed, with the instruction to pay attention to the sounds of the scanner environment. Group independent component analysis was performed to investigate training-related changes in functional connectivity. Significant MBSR-related differences in functional connectivity were found mainly in auditory/salience and medial visual networks. Relative to findings in the control group, MBSR subjects showed (1) increased functional connectivity within auditory and visual networks, (2) increased functional connectivity between auditory cortex and areas associated with attentional and self-referential processes, (3) stronger anticorrelation between auditory and visual cortex, and (4) stronger anticorrelation between visual cortex and areas associated with attentional and self-referential processes. These findings suggest that 8 weeks of mindfulness meditation training alters intrinsic functional connectivity in ways that may reflect a more consistent attentional focus, enhanced sensory processing, and reflective awareness of sensory experience.

Randomized clinical trial of short-term outcomes following purse-string versus conventional closure of ileostomy wounds

Background

Ileostomy closure is an operation with an underappreciated morbidity, including surgical-site infection, small bowel obstruction and anastomotic leakage. Surgical-site infections, in particular, are a frequent occurrence following closure of contaminated wounds. This randomized controlled trial compared a purse-string closure technique with conventional linear closure.

Methods

Sixty-one patients were randomized to conventional or purse-string closure of ileostomy wounds. The primary endpoint was the incidence of surgical-site infection, including infections requiring hospital or community treatment.

Results

Purse-string closure resulted in fewer surgical-site infections than conventional closure: two of 30 versus 12 of 31 respectively (P = 0·005).

Conclusion

The purse-string method results in a clinically relevant reduction in surgical-site infections after ileostomy closure. Registration number: ACTRN12609000021279 (Australian New Zealand Clinical Trials Registry: http://www.anzctr.org.au/).

Effect of a 3-day high-fat feeding period on carbohydrate balance and ad libitum energy intake in humans

OBJECTIVE

A reduction in glycogen after the switch to an isoenergetic high-fat diet (HFD) might promote a compensatory increase in food intake to reestablish carbohydrate balance. We assessed the effect of an isoenergetic switch from a 49%-carbohydrate to 50%-fat diet on nutrient balance and ad libitum food intake. We hypothesized that carbohydrate balance would be inversely related to ad libitum energy intake.

METHODS

In 47 men and 11 women (22.6+/-0.4 years; 26.1+/-0.5 kg m(-2)), fuel balance was measured in a respiration chamber over 4 days. During the first day, an isoenergetic, high-carbohydrate diet was provided followed by a 3-day isoenergetic, HFD. At the end of this period and after 16 h of fasting, three options of foods (cookies, fruit salad and turkey sandwich) were offered ad libitum for 4 h. The relationships between post-chamber ad libitum intake and macronutrient oxidation and balance measured day-to-day and over the 4-day respiration chamber stay were studied.

RESULTS

After switching to a HFD, 24-h respiratory quotient decreased from 0.87+/-0.02 to 0.83+/-0.02 (P<0.0001) resulting in a 4-day cumulative carbohydrate, fat and protein balances of -183+/-368, 342+/-480 and 65+/-267 kcal, respectively. Cumulative energy balance (224+/-362 kcal per 4 days) did not influence ad libitum energy intake. However, we detected that 4-day carbohydrate balance was a positive and independent predictor of post-chamber ad libitum energy intake (R (2)=0.10; P=0.01), whereas no significant influence of fat and protein balances was found.

CONCLUSION

In response to an isoenergetic change from a high-carbohydrate to HFD, higher carbohydrate balance related to increased energy intake.

Organic contaminants in sewage sludge (biosolids) and their significance for agricultural recycling

Organic chemicals discharged in urban wastewater from industrial and domestic sources, or those entering through atmospheric deposition onto paved areas via surface run-off, are predominantly lipophilic in nature and therefore become concentrated in sewage sludge, with potential implications for the agricultural use of sludge as a soil improver. Biodegradation occurs to varying degrees during wastewater and sludge treatment processes. However, residues will probably still be present in the resulting sludge and can vary from trace values of several micrograms per kilogram up to approximately 1 per cent in the dry solids for certain bulk chemicals, such as linear alkylbenzene sulphonate, which is widely used as a surfactant in detergent formulations. However, the review of the scientific literature on the potential environmental and health impacts of organic contaminants (OCs) in sludge indicates that the presence of a compound in sludge, or of seemingly large amounts of certain compounds used in bulk volumes domestically and by industry, does not necessarily constitute a hazard when the material is recycled to farmland. Furthermore, the chemical quality of sludge is continually improving and concentrations of potentially harmful and persistent organic compounds have declined to background values. Thus, recycling sewage sludge on farmland is not constrained by concentrations of OCs found in contemporary sewage sludges. A number of issues, while unlikely to be significant for agricultural utilization, require further investigation and include: (i) the impacts of chlorinated paraffins on the food chain and human health, (ii) the risk assessment of the plasticizer di(2-ethylhexyl)phthalate, a bulk chemical present in large amounts in sludge, (iii) the microbiological risk assessment of antibiotic-resistant micro-organisms in sewage sludge and sludge-amended agricultural soil, and (iv) the potential significance of personal-care products (e.g. triclosan), pharmaceuticals and endocrine-disrupting compounds in sludge on soil quality and human health.

Effect of valproic acid on body weight, food intake, physical activity and hormones: results of a randomized controlled trial

The objective of this study was to identify mechanisms through which valproic acid (VPA) causes weight gain. Healthy participants (N = 52) were randomized to VPA or placebo in a double-blind study. Energy intake (EI) was measured in the laboratory at lunch and dinner, and physical activity (PA) was measured with accelerometry. Glucose levels and hormones [Peptide YY(3-36), glucagon-like peptide-1 (GLP-1), leptin, ghrelin, insulin] that regulate EI were measured. Assessments occurred at baseline and week 3. Change from baseline was evaluated with mixed models (alpha = 0.05). Weight significantly increased in the VPA group (+0.49 kg), but not the placebo group. The VPA group increased fast food fats cravings and decreased glucose levels compared with placebo. Change in weight, EI and PA did not differ by group. Within group analyses indicated that the VPA group increased PA, hunger, binge eating, depression and GLP-1. VPA-associated weight gain is not likely due to changes in PA or the gut hormones studied. Although EI did not increase when measured after 3 weeks of treatment, VPA decreased glucose levels and increased motivation to eat; hence, EI might have increased in the short-term. Research testing VPA on short-term (1 week) EI, metabolism, and substrate partitioning is warranted.

Expression profile of mRNAs encoding core circadian regulatory proteins in human subcutaneous adipose tissue: correlation with age and body mass index

Objective

Circadian mechanisms underlie the physiology of mammals as an adaptation to the earth’s rotation on its axis. Highly conserved core circadian regulatory proteins (CCRP) maintain an oscillatory expression profile in the central and peripheral tissues. The CCRP include both a positive and negative arm as well as downstream transcriptional regulators. Recent studies in murine models have determined that the mRNAs encoding the CCRP are present in multiple adipose tissue depots and exhibit a robust oscillatory expression profile. The current study set out to examine the expression of CCRP mRNAs in human subcutaneous adipose tissues.

Design

Retrospective analysis of total RNA isolated from subcutaneous adipose tissue.

Subjects

150 healthy female and male lean (BMI < 25), overweight (BMI between 25 and 29.99) or obese (BMI >30) subjects of varied ethnic backgrounds undergoing elective liposuction or surgical procedures.

Results

The expression of the CCRP mRNAs displayed a significant correlation between each other and mRNAs representative of adipogenic biomarkers. Hierarchical cluster analyses of mRNAs isolated from the cohort of female Caucasian subjects (n = 116) identified three major clusters based on expression of downstream CCRP mRNAs. The mRNAs encoding D site of albumin promoter binding protein (DBP), E4 promoter binding protein 4 (E4BP4), PPARγ Co-Activator 1β (PGC-1β), and Rev-erb α were negatively correlated with BMI in a lean cluster (n = 66), positively correlated with BMI in a younger overweight/obese cluster (n = 19), and not significantly correlated with BMI in an older, overweight/obese cluster (n = 31).

Conclusions

These data confirm and extend findings that link the CCRP and circadian mechanisms to the risk of obesity.

Short communication: Attempts to identify Clostridium botulinum toxin in milk from three experimentally intoxicated Holstein cows

Three adult lactating Holstein cows were injected in the subcutaneous abdominal vein with 175 ng/kg of body weight of Clostridium botulinum type C toxin (451 cow median toxic doses) to determine if this botulinum toxin crosses the blood-milk barrier. Whole blood (in sodium heparin) and clotted blood serum samples were taken at 0 min, 10 min, and 3, 6, 9, and 12 h postinoculation. Milk samples were taken at 0 min and at 3, 6, 9 and 12 h postinoculation. All samples were tested for the presence of the toxin using the mouse bioassay and immunostick ELISA test. The immunostick ELISA identified the toxin in whole blood and the mouse bioassay identified the toxin in serum at all times examined in all 3 animals. Toxin was not identified by either detection method in milk samples collected from the 3 animals. From these results, it appears that Clostridium botulinum type C toxin does not cross from the blood to the milk in detectable concentrations.

Pioglitazone treatment in type 2 diabetes mellitus when combined with portion control diet modifies the metabolic syndrome

BACKGROUND

Treatment with thiazolidinediones (TZDs) produces weight gain.

OBJECTIVE

To test whether a portion control diet could prevent weight gain during treatment with pioglitazone in patients with type 2 diabetes mellitus (T2DM).

DESIGN

This 16-week randomized, open-label, parallel arm study compared three groups: (i) pioglitazone plus the American Diabetes Association diet (Pio + ADA); (ii) pioglitazone plus a portion control weight loss diet (Pio + PC); (iii) metformin plus the American Diabetes Association diet (Met + ADA). All participants received the same advice about calorie reduction, lifestyle change and exercise.

METHODS

Fifty-one men and women with T2DM, naive to TZDs, were randomized to a 16-week study. Pioglitazone (Pio) was titrated to a dose of 45 mg/day and metformin (Met) to a dose of 2 g/day. Fasting blood was collected for lipids, insulin and glycosylated haemoglobin A1c (HbA1c) at baseline and 16 weeks.

RESULTS

Forty-eight of fifty-one randomized subjects completed the study. Patients treated with Pio + ADA gained 2.15 +/- 1.09 kg (mean +/- SD) compared with a weight loss of 2.59 +/- 1.25 kg (p < 0.05) in the Pio + PC group, and a weight loss of 3.21 +/- 0.7 kg (p < 0.05) in the Met + ADA group. Waist circumference and visceral adipose tissue decreased significantly more in the Pio + PC group than in the Pio + ADA group. High-density lipoprotein cholesterol levels were significantly increased in the Pio + PC group compared with the Met + ADA group. Pioglitazone reduced insulin resistance (homeostasis model assessment of insulin resistance (HOMA-IR)) more than metformin. No significant differences between groups were seen for glucose, insulin, HbA1c or low-density lipoprotein cholesterol levels.

CONCLUSIONS

Pio + PC, prevented weight gain, reduced waist circumference and visceral fat compared with Pio + ADA diet.

Subtyping obesity with microarrays: implications for the diagnosis and treatment of obesity

OBJECTIVE

Obese patients respond differently to weight loss interventions. No efficient diagnostic tool exists to separate obese patients into subtypes as a means to improve prediction of response to interventions. We aimed to separate obese subjects into distinct subgroups using microarray technology to identify gene expression-based subgroups to predict weight loss.

DESIGN

A total of 72 obese men and women without family history of diabetes were enrolled in the study; 52 were treated with ephedra and caffeine (E+C) and 20 with placebo for 8 weeks. Adipose and skeletal muscle tissue biopsies were performed at baseline. RNA sample pairs were labeled and hybridized to oligonucleotide microarrays. Quantile normalization and gene shaving were performed, and a clustering algorithm was then applied to cluster subjects based on their gene expression profile. Clusters were visualized using heat maps and related to weight changes.

RESULTS

Cluster analysis of gene expression data revealed two distinct subgroups of obesity and predicted weight loss in response to the treatment with E+C. One cluster ('red') decreased to 96.87+/-2.35% body weight, and the second cluster ('green') decreased to 95.59+/-2.75% body weight (P<0.05). 'Red' cluster had less visceral adipose tissue mass (2.77+/-1.08 vs 3.43+/-1.49 kg; P<0.05) and decreased size of the very large fat cells (1.45+/-0.61 vs 2.16+/-1.74 microl; P<0.05) compared to 'green' cluster. Gene expression for both skeletal muscle and adipose tissue was also different between clusters.

CONCLUSIONS

Our study provides the first evidence that the combined approach of gene expression profiling and cluster analysis can identify discrete subtypes of obesity, these subtypes have different physiological characteristics and respond differently to an adrenergic weight loss therapy. This brings us that into an era of personalized treatment in the obesity clinic.

Rapid screening procedure to optimise the anaerobic codigestion of industrial biowastes and agricultural livestock wastes in Cyprus

Small-scale experimental investigations were undertaken on the anaerobic digestion (AD) and codigestion of livestock waste and industrial biowastes. A simple procedure was developed to rapidly determine the suitability of wastes for digestion. The experiment was split into two phases; initially, the seed (digested brewery waste) was replaced by the test waste over a period of 5 days. During the second phase, the test waste was incubated and monitored for methanogenesis. Dairy cattle slurry was the most efficient co-substrate which, when codigested with pig slurry in an equal ratio achieved volatile solids destruction of 32%, CH(4) production rate of 97.4 ml d(-1), maximum CH(4) content of 61.6% and total gas yield of 2229 ml after 529 h. High fat content wastes were unsuitable for AD due to low pH value and because the dominant microbial reaction was fermentation. Codigestion was investigated to overcome any inhibitions; however, dairy cattle slurry, abattoir wastewater and NaOH additions did not lead to methanogenesis. Treating these wastes by AD is feasible but without CH(4) production.

Methods to improve the composting process of the solid fraction of dairy cattle slurry

Cattle slurry solid fraction (SF) with different dry matter (DM) contents was collected from two dairy farms and composted in static and turned piles, with different sizes and cover types, to investigate the effects of pile conditions on the physical and chemical changes in SF during composting and to identify approaches to improve final compost quality. Thermophilic temperatures were attained soon after separation of SF, but the temperature of piles covered with polyethylene did not increase above 60 degrees C. The rate of organic matter (OM) mineralisation increased for turned piles in comparison to static piles, but the maximum amount of mineralisable OM (630-675gkg(-1)) was similar for all pile treatments. The C/N ratio declined from over 36 to a value of 14 towards the end of composting, indicating an advanced degree of OM stabilisation. Mature compost was obtained from raw SF feedstock as indicated by the low compost temperature, low C/N ratio, and low content of NH(4)(+) combined with increased concentrations of NO(3)(-). The efficiency of the composting process was improved and NH(3)-N losses were minimized by increasing DM content of the SF, reducing the frequency of pile turning and managing compost piles without an impermeable cover.

Degradation and plant uptake of nonylphenol (NP) and nonylphenol-12-ethoxylate (NP12EO) in four contrasting agricultural soils

Nonylphenol polyethoxylates (NPEOs) are surfactants found ubiquitously in the environment due to widespread industrial and domestic use. Biodegradation of NPEOs produces nonylphenol (NP), an endocrine disruptor. Sewage sludge application introduces NPEOs and NP into soils, potentially leading to accumulation in soils and crops. We examined degradation of NP and nonylphenol-12-ethoxylate (NP12EO) in four soils. NP12EO degraded rapidly (initial half time 0.3-5 days). Concentrations became undetectable within 70-90 days, with a small increase in NP concentrations after 30 days. NP initially degraded quickly (mean half time 11.5 days), but in three soils a recalcitrant fraction of 26-35% remained: the non-degrading fraction may consist of branched isomers, resistant to biodegradation. Uptake of NP by bean plants was also examined. Mean bioconcentration factors for shoots and seeds were 0.71 and 0.58, respectively. Removal of NP from the soil by plant uptake was negligible (0.01-0.02% of initial NP). Root concentrations were substantially higher than shoot and seed concentrations.

Increased visceral fat and decreased energy expenditure during the menopausal transition

OBJECTIVE

This study assessed longitudinal changes in body composition, fat distribution and energy balance in perimenopausal women. We hypothesized that total fat and abdominal body fat would increase at menopause due to decreased energy expenditure (EE) and declining estrogen, respectively.

DESIGN

Observational, longitudinal study with annual measurements for 4 years.

SUBJECTS

Healthy women (103 Caucasian; 53 African-American), initially premenopausal. During follow-up, lack of menstruation for 1 year and follicle-stimulating hormone >30 mIU ml(-1) defined a subject as postmenopausal.

MEASUREMENTS

Fat and lean mass (dual-energy X-ray absorptiometry), visceral (VAT) and subcutaneous abdominal fat (SAT) (computed tomography), dietary intake (4-day food record), serum sex hormones and physical activity (tri-axial accelerometry). Twenty-four hour EE was measured by whole-room calorimeter in a subset of 34 women at baseline and at year 4.

RESULTS

Body fat and weight increased significantly over time only in those women who became postmenopausal by year 4 (n=51). All women gained SAT over time; however, only those who became postmenopausal had a significant increase in VAT. The postmenopausal group also exhibited a significant decrease in serum estradiol. Physical activity decreased significantly 2 years before menopause and remained low. Dietary energy, protein, carbohydrate and fiber intake were significantly higher 3-4 years before the onset of menopause compared with menopause onset. Twenty-four hour EE and sleeping EE decreased significantly with age; however, the decrease in sleeping EE was 1.5-fold greater in women who became postmenopausal compared with premenopausal controls (-7.9 vs -5.3%). Fat oxidation decreased by 32% in women who became postmenopausal (P<0.05), but did not change in those who remained premenopausal.

CONCLUSION

Middle-aged women gained SAT with age, whereas menopause per se was associated with an increase in total body fat and VAT. Menopause onset is associated with decreased EE and fat oxidation that can predispose to obesity if lifestyle changes are not made.

Strong association between mitochondrial DNA copy number and lipogenesis in human white adipose tissue

AIMS/HYPOTHESIS

Recent studies suggest a link between insulin resistance and mitochondrial function in white fat cells. The aim of this study was to evaluate adipocyte mitochondrial DNA (mtDNA) copy number in relation to adipocyte and clinical variables that are related to insulin sensitivity.

METHODS

We studied a group of 148 healthy volunteers with a large inter-individual variation in BMI. Relative amounts of mtDNA and nuclear DNA were determined by quantitative RT-PCR. The mtDNA:nuclear DNA ratio reflects the tissue concentration of mtDNA per cell.

RESULTS

The mtDNA copy number was enriched in adipocytes of adipose tissue and decreased slightly by ageing (p = 0.015) and increasing BMI (p = 0.004); however, it was not influenced by sex, energy-restricted diets or marked long-term weight reduction. Adipose mtDNA copy number was not independently related to resting energy expenditure, overall insulin sensitivity or adipocyte lipolysis. However, it showed a strong positive correlation with basal (p = 0.0012) and insulin-stimulated lipogenesis (p < 0.0001) in fat cells, independently of age and BMI, and a weak positive correlation with levels of mRNA from several genes involved in mitochondrial oxidative capacity (r = 0.2-0.3).

CONCLUSIONS/INTERPRETATION

The mtDNA copy number in human white fat cells is fairly stable within healthy individuals. It is not influenced by sex or weight loss and is not important for overall insulin sensitivity or energy expenditure at rest. However, it is strongly related to adipocyte lipogenesis and weakly to mitochondrial oxidative capacity, suggesting that adipocyte mitochondria are, above all, local regulators.

Field investigations on the survival of Escherichia coli and presence of other enteric micro-organisms in biosolids-amended agricultural soil

AIMS

To measure the survival of enteric micro-organisms in agricultural soil amended with conventional and enhanced treated biosolids in relation to environmental and edaphic conditions.

METHODS AND RESULTS

Escherichia coli, Salmonella and F-specific RNA bacteriophage were enumerated in sludge and amended soil. Salmonella was not detected and only small numbers of bacteriophages were found in conventional, dewatered mesophilic anaerobically digested biosolids (DMAD). Neither organism was detected in soil. Escherichia coli numbers in soil increased with DMAD application compared with the unamended control, or soil receiving enhanced treated, thermally dried digested (TDD) and composted (CPT) biosolids. Empirical statistical models were developed summarizing the relationship between soil temperature, moisture content and time and E. coli populations. Background numbers of E. coli declined with increasing soil temperature and decreasing soil moisture responding to seasonal patterns in environmental conditions. Time following application was the only significant explanatory variable of E. coli numbers and decay in DMAD-amended soil.

CONCLUSIONS

E. coli are an indigenous component of the microbial community in field soil and populations increased in cool, moist soil during autumn-winter and declined in warm, dryer soil during spring-summer. Enhanced treated biosolids were not a source of E. coli, but reduced the size of the indigenous population possibly by stimulating the activity of predatory and competing soil flora because of the organic substrate input from sludge. Conventionally treated biosolids increased E. coli numbers in soil. However, introduced bacteria declined rapidly and survival was limited to 3 months, irrespective of the timing of sludge application or environment.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results provide assurance that residual numbers of pathogens applied to soil in treated biosolids decay to background values well within cropping and harvesting restrictions imposed when sewage sludge is spread on farmland.

In vivo measurement of tissue metabolism in tendons of the rotator cuff

We have undertaken an in vivo assessment of the tissue metabolism and cellular activity in torn tendons of the rotator cuff. Cellular oxygen consumption was measured in 13 patients undergoing mini-open repair of small, medium, large and massive full-thickness tears. Measurements were also taken from three control patients who were undergoing open stabilisation of the shoulder with grossly normal tendons. The level of oxygen and nitrous oxide was measured amperometrically using silver needle microelectrodes at the apex of the tear and 1.5 cm from its edge. With nitrous oxide indicating the degree of perfusion, oxygen consumption was calculated at each location to reflect cellular activity.

All of the torn tendons had lower levels of cellular activity than the control group. This activity was lower still in the tissue nearest to the edge of the tear with the larger tears showing the lowest activity. This indicated reduced levels of tissue metabolism and infers a reduction in tendon viability.

Our findings suggest that surgical repair of torn tendons of the rotator-cuff should include the more proximal, viable tissue, and may help to explain the high rate of re-rupture seen in larger tears.

Barriers to accessing HIV/AIDS care in North Carolina: Rural and urban differences

Many HIV-positive individuals face multiple barriers to care and therefore frequently experience unmet medical and support services needs. Rural areas often lack the infrastructure to support the delivery of comprehensive HIV services; however, few studies have examined service barriers faced by rural residents with HIV/AIDS, particularly in the South where two-thirds of people living with HIV/AIDS in rural areas reside. We surveyed North Carolina HIV/AIDS case managers (N = 111) employed at state-certified agencies regarding barriers to medical and support services that influence medication adherence for their rural and urban-living clients. For each of the seven barriers assessed (long travel for care, HIV-related stigma, and a lack of transportation; HIV-trained medical practitioners; housing; mental health services and substance abuse treatment), a substantial proportion of case managers (29-67%) reported it was a 'major problem'. For five of the seven barriers, rural case managers were significantly more likely to identify the barrier as a 'major problem'. Multivariate analysis revealed that rural case managers and case managers with more female clients reported a greater number of barriers. Because unmet medical and support service needs may result in poorer outcomes for HIV-positive individuals, barriers to these services must be identified and addressed, particularly in rural areas which may be highly underserved.

A rare mutation in AgRP, +79G>A, affects promoter activity

The agouti-related protein is a powerful orexigenic peptide. A rare mutation, +79G>A, was identified in its minimal promoter in two white carriers. Comparison of the 45-year-old male proband, who was also a carrier of the common Ala67Thr polymorphism, with an age- and weight-matching wild-type population showed marginal differences for resting metabolic rate (RMR) and body mass index. The second carrier however was an obese 57-year-old female with reduced RMR. Functional analysis in hypothalamus- and periphery-derived cell lines showed reduced promoter activity for the +79A allele in the adrenocortical cells only, suggesting that it could affect the peripheral expression levels of AgRP. The +79G>A mutation could predispose to body weight gain (as suggested by the phenotype of the second carrier), but it could only affect the proband at an older age as he may be protected by the Ala67Thr polymorphism that is associated with resistance to late-onset fatness.

A comparison of two chlorhexidine gel brushing regimens and a conventional toothpaste brushing regimen for the development of tooth staining over a 6-week period

AIMS

A single-centre, randomized single-blind parallel study was undertaken to compare staining seen with three brushing regimens and to determine subject perception of side effects such as staining and effects on taste.

METHODS

This 6-week parallel study used 157 volunteers who were randomized into one of three treatment groups: (i) brushing in the morning and evening with a normal dose of a 1% chlorhexidine gel, (ii) brushing with a low dose of chlorhexidine gel in the evening and a whitening dentifrice in the morning, and (iii) brushing with a standard fluoride paste in the morning and evening. Following home usage of their allocated products, the study volunteers returned after 3 and 6 weeks to record the amount of stain present. After the 6-week period, subject perception of taste and stain acceptability was determined using a questionnaire.

RESULTS

After 6 weeks of use of the low-dose chlorhexidine gel and whitening dentifrice, significantly more stain was seen compared with the use of a standard dentifrice (P<0.0001). Similarly, significantly more stain was seen with use of the normal-dose chlorhexidine gel compared with the low-dose gel and whitening dentifrice (P=0.0007). Approximately 30% of individuals on the low-dose chlorhexidine gel regimen found the amount of stain unacceptable and 10% noted an effect on their taste perception.

CONCLUSIONS

The use of low dose of chlorhexidine gel at night and a whitening paste in the morning produced a significant amount of stain that 30% of subjects considered unacceptable.