Pembrolizumab versus placebo as post-nephrectomy adjuvant therapy for clear cell renal cell carcinoma (KEYNOTE-564): 30-month follow-up analysis of a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial

BACKGROUND

The first interim analysis of the KEYNOTE-564 study showed improved disease-free survival with adjuvant pembrolizumab compared with placebo after surgery in patients with clear cell renal cell carcinoma at an increased risk of recurrence. The analysis reported here, with an additional 6 months of follow-up, was designed to assess longer-term efficacy and safety of pembrolizumab versus placebo, as well as additional secondary and exploratory endpoints.

METHODS

In the multicentre, randomised, double-blind, placebo-controlled, phase 3 KEYNOTE-564 trial, adults aged 18 years or older with clear cell renal cell carcinoma with an increased risk of recurrence were enrolled at 213 hospitals and cancer centres in North America, South America, Europe, Asia, and Australia. Eligible participants had an Eastern Cooperative Oncology Group performance status of 0 or 1, had undergone nephrectomy 12 weeks or less before randomisation, and had not received previous systemic therapy for advanced renal cell carcinoma. Participants were randomly assigned (1:1) via central permuted block randomisation (block size of four) to receive pembrolizumab 200 mg or placebo intravenously every 3 weeks for up to 17 cycles. Randomisation was stratified by metastatic disease status (M0 vs M1), and the M0 group was further stratified by ECOG performance status and geographical region. All participants and investigators involved in study treatment administration were masked to the treatment group assignment. The primary endpoint was disease-free survival by investigator assessment in the intention-to-treat population (all participants randomly assigned to a treatment). Safety was assessed in the safety population, comprising all participants who received at least one dose of pembrolizumab or placebo. As the primary endpoint was met at the first interim analysis, updated data are reported without p values. This study is ongoing, but no longer recruiting, and is registered with ClinicalTrials.gov, NCT03142334.

FINDINGS

Between June 30, 2017, and Sept 20, 2019, 994 participants were assigned to receive pembrolizumab (n=496) or placebo (n=498). Median follow-up, defined as the time from randomisation to data cutoff (June 14, 2021), was 30·1 months (IQR 25·7-36·7). Disease-free survival was better with pembrolizumab compared with placebo (HR 0·63 [95% CI 0·50-0·80]). Median disease-free survival was not reached in either group. The most common all-cause grade 3-4 adverse events were hypertension (in 14 [3%] of 496 participants) and increased alanine aminotransferase (in 11 [2%]) in the pembrolizumab group, and hypertension (in 13 [3%] of 498 participants) in the placebo group. Serious adverse events attributed to study treatment occurred in 59 (12%) participants in the pembrolizumab group and one (<1%) participant in the placebo group. No deaths were attributed to pembrolizumab.

INTERPRETATION

Updated results from KEYNOTE-564 support the use of adjuvant pembrolizumab monotherapy as a standard of care for participants with renal cell carcinoma with an increased risk of recurrence after nephrectomy.

FUNDING

Merck Sharp & Dohme LLC, a subsidiary of Merck & Co, Inc, Rahway, NJ, USA.

Celiac disease and bone health: is there a gap in the management of postmenopausal osteoporosis?

Malabsorption due to celiac disease (CD) may contribute to postmenopausal osteoporosis. This study aimed to survey participants with CD regarding their bone density, fractures, and bone-preserving medications; to compare tolerance of bone-preserving medications in participants with and without CD; and to review the evidence for CD screening and osteoporosis therapies in the setting of CD. We recruited 131 participants with CD and 102 participants without CD. Of those with CD, 87% were diagnosed in adulthood and 40% had no recognized gastrointestinal symptoms. In 21% CD was diagnosed after the diagnosis of osteoporosis and in 9% after a fracture. No difference was found in the tolerability of bone medications between participants with CD and those without. Review of the literature found that, although monitoring of bone health is recommended for patients with CD, screening for CD is not generally accepted for patients with osteoporosis, although studies of the prevalence of CD in osteoporosis had incomplete ascertainment methods. There is a lack of well-conducted studies and therefore insufficient data for the efficacy and tolerability of bone medication in CD. In conclusion, both CD and menopause lead to bone loss. Identifying CD in postmenopausal women should lead to modification of osteoporosis management.

Position Statement on Atopic Dermatitis in Sub-Saharan Africa: current status and roadmap

BACKGROUND

The first International Society of Atopic Dermatitis (ISAD) global meeting dedicated to atopic dermatitis (AD) in Sub-Saharan Africa (SSA) was held in Geneva, Switzerland in April 2019. A total of 30 participants were present at the meeting, including those from 17 SSA countries, representatives of the World Health Organization (WHO), the International Foundation for Dermatology (IFD) (a committee of the International League of Dermatological Societies, ILDS www.ilds.org), the Fondation pour la Dermatite Atopique, as well as specialists in telemedicine, artificial intelligence and therapeutic patient education (TPE).

RESULTS

AD is one of the most prevalent chronic inflammatory skin diseases in SSA. Besides neglected tropical diseases (NTDs) with a dermatological presentation, AD requires closer attention from the WHO and national Departments of Health.

CONCLUSIONS

A roadmap has been defined with top priorities such as access to essential medicines and devices for AD care, in particular emollients, better education of primary healthcare workers for adequate triage (e.g. better educational materials for skin diseases in pigmented skin generally and AD in particular, especially targeted to Africa), involvement of traditional healers and to a certain extent also patient education, bearing in mind the barriers to effective healthcare faced in SSA countries such as travel distances to health facilities, limited resources and the lack of dermatological expertise. In addition, several initiatives concerning AD research in SSA were discussed and should be implemented in close collaboration with the WHO and assessed at follow-up meetings, in particular, at the next ISAD meeting in Seoul, South Korea and African Society of Dermatology and Venereology (ASDV) meeting in Nairobi, Kenya, both in 2020.

Sulfamate in environmental waters

Although sulfamate (the anion of sulfamic acid) has been in use for decades in various industrial and other applications, there is no previously published information about its occurrence and fate in environmental waters. In this study sulfamate was widely detected in environmental waters in Ontario, Canada, ranging up to 128,000ng/L. It was always detected (>100ng/L) in bulk precipitation samples and streams, it was usually detected in samples of lake water, and often detected in groundwater. Spatial and temporal variations suggest that both widespread atmospheric deposition and localized land-based anthropogenic sources of sulfamate may be important. Lower concentrations or non-detections of sulfamate in waters that had relatively low dissolved oxygen (e.g. some groundwaters) suggest that sulfamate may be degraded in the environment under suboxic or anoxic conditions. Given our findings of a wide distribution of sulfamate in environmental waters, including precipitation, it is not likely to be very useful as a wastewater tracer.

Estimating cumulative wastewater treatment plant discharge influences on acesulfame and Escherichia coli in a highly impacted watershed with a fully-integrated modelling approach

Wastewater treatment plant (WWTP) discharge is often considered a principal source of surface water contamination. In this study, a three-dimensional fully-integrated groundwater-surface water model was used to simulate the transport characteristics and cumulative loading of an artificial sweetener (acesulfame) and fecal indicator bacteria (Escherichia coli) from WWTPs within a 6800 km² mixed-use, highly impacted watershed in Ontario, Canada. The model, which employed 3.5 × 10⁶ computational nodes and 15 layers, facilitated a comprehensive assessment of groundwater-surface water interactions under high and low flow conditions; processes typically not accounted for in WWTP cumulative effects models. Simulations demonstrate that the model had significant capacity in reproducing the average and transient multi-year groundwater and surface water flow conditions in the watershed. As a proxy human-specific conservative tracer, acesulfame was useful for model validation and to help inform the representation of watershed-scale transport processes. Using a uniform WWTP acesulfame loading rate of 7.14 mg person^-1 day^-1, the general spatial trends and magnitudes of the acesulfame concentration profile along the main river reach within the watershed were reproduced; however, model performance was improved by tuning individual WWTP loading rates. Although instream dilution and groundwater-surface water interactions were strongly dependent on flow conditions, the main reach primarily consisted of groundwater discharge zones. For this reason, hydrodynamic dispersion in the hyporheic zone is shown as the predominant mechanism driving acesulfame into near-stream shallow groundwater, while under high flow conditions, the simulations demonstrate the potential for advective flushing of the shallow groundwater. Regarding the cumulative impact of the WWTPs on E. coli concentrations in the surface flow system, simulated transient E. coli levels downstream of WWTPs in the watershed were significantly lower than observed values, thus highlighting the potential importance of other sources of E. coli in the watershed.

Student engagement in a Human Anatomy and Physiology course: a New Zealand perspective

The population diversity of New Zealand is due to the unique fusion of indigenous peoples of Polynesian origin (Māori), western European colonization (Pākehā), and more recent (20th century) immigration from the Pacific region (Pasifika). However, disparities in tertiary education indicate that Māori and Pasifika students are more likely to drop out during their first year of study and are less likely to complete their qualification than their Pākehā peers. Higher levels of course engagement may increase first-year grades, elevate academic performance, and encourage persistence between the first and second years of study. Therefore, a Student Course Engagement Questionnaire was used to quantify engagement in a compulsory first-year undergraduate Human Anatomy and Physiology course in a New Zealand university. A data mining technique was used to assign students into a low-engagement/low-achievement cluster, and a high-engagement/high-achievement cluster. The skills, emotional, and participation-interaction components of engagement were lower in Pasifika students: these students' academic grade was lower than those of both Māori and Pākehā students. The strongest predictors of cluster membership were skills engagement and emotional engagement, suggesting that these components outweighed other aspects of course engagement. Māori and Pasifika students were overrepresented in the low-engagement/low-achievement cluster, and underrepresented in the high-engagement/high-achievement cluster. We suggest that embedding study skills within course delivery, and constantly emphasizing their importance, would likely increase student course engagement. Also, we report that both Māori and Pasifika students remain more disengaged than their Pākehā peers.

Randomised clinical trial: efficacy, safety and dosage of adjunctive allopurinol in azathioprine/mercaptopurine nonresponders (AAA Study)

BACKGROUND

Thiopurine hypermethylation towards 6-methylmercaptopurine (6MMP) instead of 6-thioguanine nucleotides (6TGN) is associated with inefficacy in patients with IBD. Allopurinol reverses such hypermethylation.

AIMS

To prospectively determine efficacy of allopurinol-thiopurine combination and to compare 2 doses of allopurinol.

DESIGN

In a multicentre, double-blind trial, patients with clinically active or steroid-dependent IBD and thiopurine shunting were randomised to 50 or 100 mg/d allopurinol and 25% of their screening thiopurine dose, which was subsequently optimised, aiming for 6TGN of 260-500 pmol/8x10⁸ RBCs. The primary endpoint was steroid-free clinical remission at 24 weeks.

RESULTS

Of 73 patients, 39 (53% [95% CI 42-65]) achieved steroid-free remission, (54% with 50 mg/d and 53% with 100 mg/d). 81% were able to discontinue steroids. Therapeutic 6TGN levels were achieved in both groups. Final thiopurine doses were lower with 100 mg/d allopurinol (P < 0.005). 6MMP: 6TGN ratio decreased from mean 64 to 4 (P < 0.001), being higher with 50 mg/d (6 ± 1.83) than for 100 mg/d ([1 ± 0.16], P = 0.003). Three patients on 50 mg/d failed to sustain low ratios at 24 weeks. Toxicity was minimal; three patients on 50 mg/d allopurinol developed transient leukopenia. Alanine aminotransferase concentrations decreased (P < 0.001) similarly in both arms. Faecal calprotectin levels at study end were lower in patients who achieved the primary endpoint (median 171 [85-541] vs 821[110-5892] ug/g, P = 0.03).

CONCLUSIONS

Low-dose allopurinol-thiopurine combination safely reverses shunting and optimises 6TGN with associated improvement in disease activity. 100 mg/d allopurinol is preferable due to greater metabolite profile stability and lower thiopurine dose without additional toxicity.

Altered walking strategy and increased unsteadiness in participants with impaired glucose tolerance and Type 2 diabetes relates to small-fibre neuropathy but not vitamin D deficiency

AIMS

To investigate alterations in walking strategy and dynamic sway (unsteadiness) in people with impaired glucose tolerance and people with Type 2 diabetes in relation to severity of neuropathy and vitamin D levels.

METHODS

A total of 20 people with Type 2 diabetes, 20 people with impaired glucose tolerance and 20 people without either Type 2 diabetes or impaired glucose tolerance (control group) underwent gait analysis using a motion analysis system and force platforms, and detailed assessment of neuropathy and serum 25 hydroxy-vitamin D levels.

RESULTS

Ankle strength (P = 0.01) and power (P = 0.003) during walking and walking speed (P = 0.008) were preserved in participants with impaired glucose tolerance but significantly lower in participants with Type 2 diabetes compared with control participants; however, step width (P = 0.005) and dynamic medio-lateral sway (P = 0.007) were significantly higher and posterior maximal movement (P = 0.000) was lower in participants with impaired glucose tolerance, but preserved in those with Type 2 diabetes compared with the control group. Dynamic medio-lateral sway correlated with corneal nerve fibre length (P = 0.001) and corneal nerve branch density (P = 0.001), but not with vibration perception threshold (P = 0.19). Serum 25 hydroxy-vitamin D levels did not differ significantly among the groups (P = 0.10) and did not correlate with any walking variables or measures of dynamic sway.

CONCLUSIONS

Early abnormalities in walking strategy and dynamic sway were evident in participants with impaired glucose tolerance, whilst there was a reduction in ankle strength, power and walking speed in participants with Type 2 diabetes. Unsteadiness correlated with small-, but not large-fibre neuropathy and there was no relationship between vitamin D levels and walking variables.

Introductory anatomy and physiology in an undergraduate nursing curriculum

Using an educational data mining approach, first-year academic achievement of undergraduate nursing students, which included two compulsory courses in introductory human anatomy and physiology, was compared with achievement in a final semester course that transitioned students into the workplace. We hypothesized that students could be grouped according to their first-year academic achievement using a two-step cluster analysis method and that grades achieved in the human anatomy and physiology courses would be strong predictors of overall achievement. One cohort that graduated in 2014 (n = 105) and one that graduated in 2015 (n = 94) were analyzed separately, and for both cohorts, two groups were identified, these being "high achievers" (HIGH) and "low achievers" (LOW). Consistently, the anatomy and physiology courses were the strongest predictors of group assignment, such that a good grade in these was much more likely to put a student into a high-achieving group. Students in the HIGH groups also scored higher in the Transition to Nursing course when compared with students in the LOW groups. The higher predictor importance of the anatomy and physiology courses suggested that if a first-year grade-point average was calculated for students, an increased weighting should be attributed to these courses. Identifying high-achieving students based on first-year academic scores may be a useful method to predict future academic performance.

Vulnerability to intimate partner violence and poor mental health in the first 4-year postpartum among mothers reporting childhood abuse: an Australian pregnancy cohort study

The purpose of this study was to investigate intergenerational patterns of abuse and trauma and the health consequences for women in the early childbearing years. A prospective pregnancy cohort of 1507 nulliparous women (≦24 weeks gestation) were recruited in Melbourne, Australia, 2003-2005. Follow-up was scheduled in late pregnancy, 3-, 6- and 12-month and 4-year postpartum. Childhood abuse was retrospectively reported at 4-year postpartum using the Child Maltreatment History Self Report. Intimate partner violence (IPV) was assessed at 1- and 4-year postpartum with the Composite Abuse Scale. Maternal depressive symptoms were assessed in all follow-ups using the Edinburgh Postnatal Depression Scale. Multivariable logistic regression was used to examine associations between childhood abuse, maternal mental health and IPV. Childhood abuse was reported by 41.1 % of women. In the 4 years after having their first child, 28.2 % of women reported IPV, 25.2 % depression and 31.6 % anxiety. Childhood abuse was associated with odds of depression or anxiety 1.5-2.6 times greater and 1.8-3.2 times greater for IPV. Childhood physical abuse remained significantly associated with depression and anxiety in pregnancy and postpartum after adjusting for IPV and stressful life events, while sexual abuse remained significantly associated only with anxiety. Women who begin childbearing with a history of childhood abuse are more vulnerable to IPV and poor mental health. All health care services and agencies in contact with children, young people and families should have adequate training to identify trauma associated with abuse and IPV and provide first line supportive care and referral.

Use of an Artificial Sweetener to Identify Sources of Groundwater Nitrate Contamination

The artificial sweetener acesulfame (ACE) is a potentially useful tracer of waste water contamination in groundwater. In this study, ACE concentrations were measured in waste water and impacted groundwater at 12 septic system sites in Ontario, Canada. All samples of septic tank effluent (n = 37) had ACE >6 µg/L, all samples of groundwater from the proximal plume zones (n = 93) had ACE >1 µg/L and, almost all samples from the distal plume zones had ACE >2 µg/L. Mean mass ratios of total inorganic nitrogen/ACE at the 12 sites ranged from 680 to 3500 for the tank and proximal plume samples. At five sites, decreasing ratio values in the distal zones indicated nitrogen attenuation. These ratios were applied to three aquifers in Canada that are nitrate-stressed and an urban stream where septic systems are present nearby to estimate the amount of waste water nitrate contamination. At the three aquifer locations that are agricultural, low ACE values (<0.02-0.15 µg/L) indicated that waste water contributed <15% of the nitrate in most samples. In groundwater discharging to the urban stream, much higher ACE values (0.2-11 µg/L) indicated that waste water was the likely source of >50% of the nitrate in most samples. This study confirms that ACE is a powerful tracer and demonstrates its use as a diagnostic tool for establishing whether waste water is a significant contributor to groundwater contamination or not.

People with diabetic peripheral neuropathy display a decreased stepping accuracy during walking: potential implications for risk of tripping

AIM

To examine the stepping accuracy of people with diabetes and diabetic peripheral neuropathy.

METHODS

Fourteen patients with diabetic peripheral neuropathy (DPN), 12 patients with diabetes but no neuropathy (D) and 10 healthy non-diabetic control participants (C). Accuracy of stepping was measured whilst the participants walked along a walkway consisting of 18 stepping targets. Preliminary data on visual gaze characteristics were also captured in a subset of participants (diabetic peripheral neuropathy group: n = 4; diabetes-alone group: n = 4; and control group: n = 4) during the same task.

RESULTS

Patients in the diabetic peripheral neuropathy group, and patients in the diabetes-alone group were significantly less accurate at stepping on targets than were control subjects (P < 0.05). Preliminary visual gaze analysis identified that patients diabetic peripheral neuropathy were slower to look between targets, resulting in less time being spent looking at a target before foot-target contact.

CONCLUSIONS

Impaired motor control is theorized to be a major factor underlying the changes in stepping accuracy, and potentially altered visual gaze behaviour may also play a role. Reduced stepping accuracy may indicate a decreased ability to control the placement of the lower limbs, leading to patients with neuropathy potentially being less able to avoid observed obstacles during walking.

Resistance exercise training increases lower limb speed of strength generation during stair ascent and descent in people with diabetic peripheral neuropathy

AIM

To examine the effects of a 16-week resistance exercise training intervention on the speed of ankle and knee strength generation during stair ascent and descent, in people with neuropathy.

METHODS

A total of 43 people: nine with diabetic peripheral neuropathy, 13 with diabetes but no neuropathy and 21 healthy control subjects ascended and descended a custom-built staircase. The speed at which ankle and knee strength were generated, and muscle activation patterns of the ankle and knee extensor muscles were analysed before and after a 16-week intervention period.

RESULTS

Ankle and knee strength generation during both stair ascent and descent were significantly higher after the intervention than before the intervention in the people with diabetes who undertook the resistance exercise intervention (P < 0.05). Although muscle activations were altered by the intervention, there were no observable patterns that underpinned the observed changes.

CONCLUSIONS

The increased speed of ankle and knee strength generation observed after the intervention would be expected to improve stability during the crucial weight acceptance phase of stair ascent and descent, and ultimately contribute towards reducing the risk of falling. Improvements in muscle strength as a result of the resistance exercise training intervention are likely to be the most influential factor for increasing the speed of strength generation. It is recommended that these exercises could be incorporated into a multi-faceted exercise programme to improve safety in people with diabetes and neuropathy.

Degradation of sucralose in groundwater and implications for age dating contaminated groundwater

The artificial sweetener sucralose has been in use in Canada and the US since about 2000 and in the EU since 2003, and is now ubiquitous in sanitary wastewater in many parts of the world. It persists during sewage treatment and in surface water environments and as such, has been suggested as a powerful tracer of wastewater. In this study, longer-term persistence of sucralose was examined in groundwater by undertaking a series of three sampling snapshots of a well constrained wastewater plume in Canada (Long Point septic system) over a 6-year period from 2008 to 2014. A shrinking sucralose plume in 2014, compared to earlier sampling, during this period when sucralose use was likely increasing, provides clear evidence of degradation. However, depletion of sucralose from a mean of 40 μg/L in the proximal plume zone, occurred at a relatively slow rate over a period of several months to several years. Furthermore, examination of septic tank effluent and impacted groundwater at six other sites in Canada, revealed that sucralose was present in all samples of septic tank effluent (6-98 μg/L, n = 32) and in all groundwater samples (0.7-77 μg/L, n = 64). Even though sucralose degradation is noted in the Long Point plume, its ubiquitous presence in the groundwater plumes at all seven sites implies a relatively slow rate of decay in many groundwater septic plume environments. Thus, sucralose has the potential to be used as an indicator of 'recent' wastewater contamination. The presence of sucralose identifies groundwater that was recharged after 2000 in Canada and the US and after 2003 in the EU and many Asian countries.

Tracking undergraduate student achievement in a first-year physiology course using a cluster analysis approach

A cluster analysis data classification technique was used on assessment scores from 157 undergraduate nursing students who passed 2 successive compulsory courses in human anatomy and physiology. Student scores in five summative assessment tasks, taken in each of the courses, were used as inputs for a cluster analysis procedure. We aimed to group students into high-achieving (HA) and low-achieving (LA) clusters and to determine the ability of each summative assessment task to discriminate between HA and LA students. The two clusters identified in each semester were described as HA (n = 42) and LA (n = 115) in semester 1 (HA1 and LA1, respectively) and HA (n = 91) and LA (n = 42) in semester 2 (HA2 and LA2, respectively). In both semesters, HA and LA means for all inputs were different (all P < 0.001). Nineteen students moved from the HA1 group into the LA2 group, whereas 68 students moved from the LA1 group into the HA2 group. The overall order of importance of inputs that determined group membership was different in semester 1 compared with semester 2; in addition, the within-cluster order of importance in LA groups was different compared with HA groups. This method of analysis may 1) identify students who need extra instruction, 2) identify which assessment is more effective in discriminating between HA and LA students, and 3) provide quantitative evidence to track student achievement.

Identification of translational dermatology research priorities in the U.K.: results of an electronic Delphi exercise

BACKGROUND

Translational research is the direct application of basic and applied research to patient care. It is estimated that there are at least 2000 different skin diseases; thus, there are considerable challenges in seeking to undertake research on each of these disorders.

OBJECTIVES

This electronic Delphi (e-Delphi) exercise was conducted in order to generate a list of translational dermatology research questions that are regarded as a priority for further investigations.

METHODS

During the first phase of the e-Delphi exercise, 228 research questions were generated by an expert panel that included clinical academic dermatologists, clinical dermatologists, nonclinical scientists, dermatology trainees and representatives from patient support groups.

RESULTS

Following completion of the second and third phases, 40 questions on inflammatory skin disease, 20 questions on structural skin disorders/genodermatoses, 37 questions on skin cancer and eight miscellaneous questions were designated as priority translational dermatology research questions (PRQs). In addition to PRQs on a variety of disease areas (including multiple PRQs on psoriasis, eczema, squamous cell carcinoma and melanoma), there were a number of cross-cutting themes that identified a need to investigate mechanisms/pathogenesis of disease and the necessity to improve treatments for patients with skin disease.

CONCLUSIONS

It is predicted that this list of PRQs will help to provide a strategic direction for translational dermatology research in the U.K. and that addressing this list of questions will ultimately provide clinical benefit for substantial numbers of patients with skin disorders.

Efficacy of thiopurines and adalimumab in preventing Crohn's disease recurrence in high-risk patients - a POCER study analysis

BACKGROUND

Crohn's disease recurs in the majority of patients after intestinal resection.

AIM

To compare the relative efficacy of thiopurines and anti-TNF therapy in patients at high risk of disease recurrence.

METHODS

As part of a larger study comparing post-operative management strategies, patients at high risk of recurrence (smoker, perforating disease, ≥2nd operation) were treated after resection of all macroscopic disease with 3 months metronidazole together with either azathioprine 2 mg/kg/day or mercaptopurine 1.5 mg/kg/day. Thiopurine-intolerant patients received adalimumab induction then 40 mg fortnightly. Patients underwent colonoscopy at 6 months with endoscopic recurrence assessed blind to treatment.

RESULTS

A total of 101 patients [50% male; median (IQR) age 36 (25-46) years] were included. There were no differences in disease history between thiopurine- and adalimumab-treated patients. Fifteen patients withdrew prior to 6 months, five due to symptom recurrence (of whom four were colonoscoped). Endoscopic recurrence (Rutgeerts score i2-i4) occurred in 33 of 73 (45%) thiopurine vs. 6 of 28 (21%) adalimumab-treated patients [intention-to-treat (ITT); P = 0.028] or 24 of 62 (39%) vs. 3 of 24 (13%) respectively [per-protocol analysis (PPA); P = 0.020]. Complete mucosal endoscopic normality (Rutgeerts i0) occurred in 17/73 (23%) vs. 15/28 (54%) (ITT; P = 0.003) and in 27% vs. 63% (PPA; P = 0.002). The most advanced disease (Rutgeerts i3 and i4) occurred in 8% vs. 4% (thiopurine vs. adalimumab).

CONCLUSIONS

In Crohn's disease patients at high risk of post-operative recurrence adalimumab is superior to thiopurines in preventing early disease recurrence.

Sources of aminomethylphosphonic acid (AMPA) in urban and rural catchments in Ontario, Canada: Glyphosate or phosphonates in wastewater?

Correlation analysis suggests that occurrences of AMPA in streams of southern Ontario are linked mainly to glyphosate in both urban and rural settings, rather than to wastewater sources, as some previous studies have suggested. For this analysis the artificial sweetener acesulfame was analyzed as a wastewater indicator in surface water samples collected from urban and rural settings in southern Ontario, Canada. This interpretation is supported by the concurrence of seasonal fluctuations of glyphosate and AMPA concentrations. Herbicide applications in larger urban centres and along major transportation corridors appear to be important sources of glyphosate and AMPA in surface water, in addition to uses of this herbicide in rural and mixed use areas. Fluctuations in concentrations of acesulfame and glyphosate residues were found to be related to hydrologic events.

Dyspareunia and childbirth: a prospective cohort study

OBJECTIVE

To investigate the relationship between mode of delivery, perineal trauma and dyspareunia.

DESIGN

Prospective cohort study.

SETTING

Six maternity hospitals in Melbourne, Australia.

SAMPLE

A total of 1507 nulliparous women recruited in the first and second trimesters of pregnancy.

METHOD

Data from baseline and postnatal questionnaires (3, 6, 12 and 18 months) were analysed using univariable and multivariable logistic regression.

MAIN OUTCOME MEASURE

Study-designed self-report measure of dyspareunia at 18 months postpartum.

RESULTS

In all, 1244/1507 (83%) women completed the baseline and all four postpartum questionnaires; 1211/1237 (98%) had resumed vaginal intercourse by 18 months postpartum, with 289/1211 (24%) women reporting dyspareunia. Compared with women who had a spontaneous vaginal delivery with an intact perineum or unsutured tear, women who had an emergency caesarean section (adjusted odds ratio [aOR] 2.41, 95% confidence interval [95% CI] 1.4-4.0; P = 0.001), vacuum extraction (aOR 2.28, 95% CI 1.3-4.1; P = 0.005) or elective caesarean section (aOR 1.71, 95% CI 0.9-3.2; P = 0.087) had increased odds of reporting dyspareunia at 18 months postpartum, adjusting for maternal age and other potential confounders.

CONCLUSIONS

Obstetric intervention is associated with persisting dyspareunia. Greater recognition and increased understanding of the roles of mode of delivery and perineal trauma in contributing to postpartum maternal morbidities, and ways to prevent postpartum dyspareunia where possible, are warranted.

Altered glycosylation in donor mice causes rejection of strain-matched skin and heart grafts

Differential protein glycosylation in the donor and recipient can have profound consequences for transplanted organs, as evident in ABO-incompatible transplantation and xenotransplantation. In this study, we investigated the impact of altered fucosylation on graft acceptance by using donor mice overexpressing human α1,2-fucosyltransferase (HTF). Skin and heart grafts from HTF transgenic mice were rapidly rejected by otherwise completely matched recipients (median survival times 16 and 14 days, respectively). HTF skin transplanted onto mice lacking T and B cells induced an natural killer cell-mediated innate rejection crisis that affected 50-95% of the graft at 10-20 days. However, in the absence of adaptive immunity, the residual graft recovered and survived long-term (>100 days). Experiments using "parked" grafts or MHC class II-deficient recipients suggested that indirect rather than direct antigen presentation plays a role in HTF skin graft rejection, although the putative antigen(s) was not identified. We conclude that altered glycosylation patterns on donor tissue can trigger a powerful rejection response comprising both innate and adaptive components. This has potential implications for allotransplantation, in light of increasing recognition of the variability of the human glycome, and for xenotransplantation, where carbohydrate remodeling has been a lynchpin of donor genetic modification.

Efficacy and safety of crofelemer for noninfectious diarrhea in HIV-seropositive individuals (ADVENT trial): a randomized, double-blind, placebo-controlled, two-stage study

BACKGROUND

HIV-associated diarrhea remains a significant concern with limited treatment options.

OBJECTIVE

To determine the optimal dose, efficacy, and safety of crofelemer for noninfectious diarrhea.

METHODS

This randomized, double-blind, phase 3 trial used a 2-stage design. Both stages included 2-week screening, 4-week placebo-controlled treatment, and 20-week placebo-free (open-label) extension phases. In stage I, 196 HIV-seropositive patients with chronic diarrhea were randomized to crofelemer 125 mg, 250 mg, or 500 mg or placebo twice daily. Using a prospective analysis, the 125-mg twice-daily dose was selected for stage II. In stage II, 180 new patients were randomized to crofelemer 125 mg twice daily or placebo for 4 weeks. Primary efficacy analysis was the percentage of patients (stages I/II combined) who achieved clinical response (defined as ≤2 watery stools/week during ≥2 of 4 weeks). During the placebo-free extension phase, response (≤2 watery stools) was assessed weekly.

RESULTS

Significantly more patients receiving crofelemer 125 mg achieved clinical response versus placebo (17.6% vs 8.0%; one-sided, P = .01). Crofelemer 125 mg resulted in a greater change from baseline in number of daily watery bowel movements (P = .04) and daily stool consistency score (P = .02) versus placebo. During the placebo-free extension phase, percentages of weekly responders ranged from 40% to 56% at weeks 11 to 24. Crofelemer was minimally absorbed, well tolerated, did not negatively impact clinical immune parameters, and had a safety profile comparable to placebo.

CONCLUSIONS

In HIV-seropositive patients taking stable antiretroviral therapy, crofelemer provided significant improvement in diarrhea with a favorable safety profile.

Daily kiwifruit consumption did not improve blood pressure and markers of cardiovascular function in men with hypercholesterolemia

Increasing fruit and vegetable consumption is a key lifestyle modification in the prevention and treatment of hypertension. Kiwifruit has previously been shown to have favorable effects on blood pressure (BP), likely through inhibiting angiotensin I-converting enzyme activity. We hypothesized that the replacement of 2 fruit servings in a healthy diet with 2 green kiwifruit a day would significantly improve BP and other markers of cardiovascular function, including heart rate, stroke volume, cardiac output, and total peripheral resistance, in a group of hypercholesterolemic men. Using a controlled cross-over study design, 85 subjects completed a 4-week healthy diet run-in period before randomization to one of two 4-week intervention sequences in which they either consumed 2 green kiwifruit a day plus a healthy diet (intervention) or consumed a healthy diet alone (control). Blood pressure and other measures of cardiovascular function (using a Finometer MIDI [Finapres Medical Systems B.V, Amsterdam, The Netherlands] and standard oscillometric device) and anthropometric measurements were taken before and at the end of the treatment periods. A physical activity questionnaire was completed during the last visit. Subjects were found to be predominantly normotensive (43.5%) or prehypertensive (50.6%) and quite physically active (>30 minutes of moderate to vigorous physical activity/day in >80% subjects). No significant differences were seen for BP or any of the other markers, including heart rate, stroke volume, cardiac output, and total peripheral resistance. In conclusion, in this hypercholesterolemic, nonhypertensive group, no beneficial effects on BP or other markers of cardiovascular function were seen when consuming 2 kiwifruit a day against the background of a healthy diet.

Residues of the herbicide glyphosate in riparian groundwater in urban catchments

The herbicide glyphosate and its putative metabolite aminomethylphosphonic acid (AMPA) have been found in urban streams, but limited information is available on their presence in urban riparian groundwater. Information is also lacking regarding the source of AMPA in these urban settings (glyphosate metabolite or wastewater), and whether, if present, glyphosate residues in urban riparian groundwater contribute significantly to urban streams. Glyphosate and AMPA were detected in shallow riparian groundwater at 4 of 5 stream sites in urban catchments in Canada and each were found in approximately 1 in 10 of the samples overall. Frequency of observations of glyphosate and AMPA varied substantially between sites, from no observations in a National Park near the Town of Jasper Alberta, to observations of both glyphosate and AMPA in more than half of the samples along two short reaches of streams in Burlington, Ontario. In these two catchments, AMPA was correlated with glyphosate, rather than the artificial sweetener acesulfame, suggesting that the AMPA is derived mainly from glyphosate degradation rather than from wastewater sources. Land use, localized dosage history, depth below ground and other factors likely control the occurrence of detectable glyphosate residues in groundwater.

Two orthodenticle-related genes in the short-germ beetle Tribolium castaneum

To investigate the molecular basis of head evolution, we searched for genes related to the Drosophila orthodenticle (otd) homeobox gene in the short-germ beetle Tribolium castaneum. Unexpectedly, we found that there are two otd-related genes in Tribolium, with predicted homeodomains highly similar to that of the single Drosophila gene. One of the two genes (Tc otd-1) is more related in both amino acid sequence and expression pattern to fruitfly otd. Tc otd-1 is expressed in a broad anterior stripe in the blastoderm embryo, suggesting a role in early head segmentation similar to that of the Drosophila gene. The second gene (Tc otd-2) is more similar in sequence to the otd-related genes isolated from different vertebrate species (the Otx gene family). Tc otd-2 is not transcribed in the blastoderm, but is expressed later in more limited subsets of cells in the anterior brain. Both Tribolium genes and the Drosophila gene are, unlike the vertebrate genes, also expressed at the developing ventral midline of the embryo. Our results are consistent with the idea that an otd/Otx gene specified anterior head structures in the last ancestor common to arthropods and vertebrates. Within the arthropod lineage, we propose that this gene acquired a function in cells at the developing midline prior to the duplication that generated the two Tribolium genes.

An artificial sweetener and pharmaceutical compounds as co-tracers of urban wastewater in groundwater

Groundwater in urban areas can be affected by numerous wastewater sources. Distinguishing these sources can facilitate better management of urban water resources and wastewater, and protection of urban aquatic environments. A single wastewater tracer, even if ideal (i.e. low background levels, non-reactive, low detection limits, etc.), would be unable to accomplish this task. Here, we investigated the potential advantages of using a suite of anthropogenic chemicals as co-tracers to distinguish wastewater sources that contribute to groundwater contamination at two urban sites. We considered both relatively ubiquitous and non-ubiquitous tracers in wastewater. At the Jasper (Alberta, Canada) site, concentrations of an artificial sweetener, two pharmaceutical compounds, and a degradate of nicotine in groundwater were strongly correlated as co-tracers. This evidence, along with the similar spatial distributions of these co-tracers could be used to delineate and distinguish a single municipal wastewater plume. At the Barrie (Ontario, Canada) site, there was moderate to strong correlation of the wastewater co-tracers, but local differences in their distributions and in the ratios of their concentrations could be used to infer that mixtures of two or more domestic septic plumes were present in the groundwater at this site. This study demonstrates the benefit of applying a suite of tracers to urban groundwater affected by wastewater contamination. This approach should be applicable at other urban sites.

Does method of birth make a difference to when women resume sex after childbirth?

OBJECTIVE

To investigate the timing of resumption of vaginal sex and assess associations with method of birth, perineal trauma and other obstetric and social factors.

DESIGN

Prospective pregnancy cohort study of nulliparous women.

SETTING

Melbourne, Australia.

SAMPLE

A total of 1507 nulliparous women recruited in early pregnancy (≤24 weeks).

METHOD

Women were recruited from six public hospitals. Data from hospital records and self-administered questionnaires at recruitment and 3, 6 and 12 months postpartum were analysed using univariable and multivariable logistic regression.

MAIN OUTCOME MEASURE

Resumption of vaginal sex.

RESULTS

Sexual activity was resumed earlier than vaginal sex, with 53% resuming sexual activity by 6 weeks postpartum, and 41% attempting vaginal sex. By 8 weeks a majority of women had attempted vaginal sex (65%), increasing to 78% by 12 weeks, and 94% by 6 months. Compared with women who had a spontaneous vaginal birth with an intact perineum, women who had a spontaneous vaginal birth with an episiotomy (adjusted odds ratio 3.43, 95% confidence interval 1.9-6.2) or sutured perineal tear (adjusted odds ratio 3.18, 95% confidence interval 2.1-4.9) were more likely not to have resumed vaginal sex by 6 weeks postpartum. Similarly, women who had an assisted vaginal birth or caesarean section had raised odds of delaying resumption of sex.

CONCLUSIONS

Most women having a first birth do not resume vaginal sex until later than 6 weeks postpartum. Women who have an operative vaginal birth, caesarean section or perineal tear or episiotomy appear to delay longer.

The onset, recurrence and associated obstetric risk factors for urinary incontinence in the first 18 months after a first birth: an Australian nulliparous cohort study

OBJECTIVE

To investigate the contribution of obstetric risk factors to persistent urinary incontinence (UI) between 4 and 18 months postpartum.

DESIGN

Prospective pregnancy cohort.

SETTING

Six metropolitan public hospitals in Victoria, Australia.

SAMPLE

A total of 1507 nulliparous women recruited to the Maternal Health Study in early pregnancy (≤24 weeks of gestation).

METHODS

Data from hospital records and self-administered questionnaires/telephone interviews at ≤24 and 30-32 weeks of gestation and at 3, 6, 9, 12 and 18 months postpartum analysed using logistic regression.

MAIN OUTCOME MEASURES

Persistent UI 4-18 months postpartum in women continent before pregnancy.

RESULTS

Of the women who were continent before pregnancy, 44% reported UI 4-18 months postpartum, and 25% reported persistent UI (symptoms at multiple follow ups). Compared with spontaneous vaginal birth, women who had a caesarean before labour (adjusted odds ratio [aOR] 0.4, 95% confidence interval [95% CI] 0.2-0.9), in first-stage labour (aOR 0.4, 95% CI 0.2-0.6) or in second-stage labour (aOR 0.4, 95% CI 0.2-1.0) were less likely to report persistent UI 4-18 months postpartum. Prolonged second-stage labour in women who had an operative vaginal birth was associated with increased likelihood of UI (aOR 2.5, 95% CI 1.3-4.6). Compared with women who were continent in pregnancy, women reporting UI in pregnancy had a seven-fold increase in odds of persistent UI (aOR 7.4, 95% CI 5.1-10.7).

CONCLUSIONS

Persistent UI is common after childbirth and is more likely following prolonged labour in combination with operative vaginal birth. The majority of women reporting persistent UI at 4-18 months postpartum also experienced symptoms in pregnancy.

Wide spectrum of filaggrin-null mutations in atopic dermatitis highlights differences between Singaporean Chinese and European populations

BACKGROUND

Null mutations in the filaggrin gene (FLG) cause ichthyosis vulgaris (IV) and predispose to atopic dermatitis (AD). Cohort studies in Europe and Japan have reported an FLG mutation carrier frequency of between 14% and 56%, but the prevalent European FLG mutations are rare or absent in Chinese patients with IV and AD.

OBJECTIVES

To investigate further the spectrum of FLG-null mutations in Chinese patients and to compare it with that in other populations.

METHODS

We conducted comprehensive FLG genetic analysis in a discovery cohort of 92 Singaporean Chinese individuals with IV and/or moderate-to-severe AD. All detected FLG mutations were then screened in a cohort of 425 patients with AD and 440 normal controls. Results In total, 22 FLG-null mutations, of which 14 are novel, were identified in this study; the combined null FLG genotype of 17 mutations detected in cases and controls showed strong association with AD [Fisher's exact test; P = 5·3 × 10⁻⁹; odds ratio (OR) 3·3], palmar hyperlinearity (Fisher's exact test; P = 9·0 × 10⁻¹⁵; OR 5·8), keratosis pilaris (Fisher's exact test; P = 0·001; OR 4·7) and with increased severity of AD (permutation test; P = 0·0063).

CONCLUSIONS

This study emphasizes the wider genetic landscape of FLG-null mutations in Asia that is slowly emerging.

Low urinary iodine postpartum is associated with hypothyroid postpartum thyroid dysfunction and predicts long-term hypothyroidism

BACKGROUND

Postpartum thyroid dysfunction (PPTD) is characterized by an early hyperthyroid phase followed, with peak prevalence at 6 months, by a hypothyroid phase which carries a risk of long-term hypothyroidism. Iodine has a major effect on thyroid function. Western Australia has previously been shown to be iodine replete.

OBJECTIVE

To examine the iodine status of women with and without PPTD and the relationship of iodine status postpartum with long-term hypothyroidism.

DESIGN

Case-control with follow-up.

PATIENTS

A total of 149 women at 6 months postpartum (74 PPTD, 75 controls) with 98 (46 PPTD, 52 controls) followed up at 12 years.

MEASUREMENTS

Urinary iodine concentration (UIC) and thyroid function at 6 months postpartum; thyroid function at 12-year follow-up.

RESULTS

At 6 months postpartum, median UIC (quartiles) for observed TSH ranges were: for TSH < 0·4 mU/l 130·0 μg/l (82·0, 170·0); for TSH 0·4-4·0 mU/l 123·0 μg/l (80·5, 168·0); for TSH > 4·0 mU/l 85·0 μg/l (40·0, 141·5), P = 0·018. The odds ratio (OR) of hypothyroid PPTD with each unit of decreasing log iodine was 2·54, (95%CI: 1·47, 4·35), and with UIC < 50 μg/l, OR 4·22, (95%CI: 1·54, 11·55). In the long term, decreased log UIC significantly predicted hypothyroidism at 12-year follow-up (P = 0·002); as did UIC < 100 μg/l (P = 0·03) and UIC < 50 μg/l (P = 0·02). The association was independent of antibody status.

CONCLUSION

Low UIC measured at 6 months postpartum is associated with hypothyroid PPTD and independently predicts long-term hypothyroidism. We believe that it results from more severe preceding destructive thyroiditis, with discharge of thyroidal iodine, and thereby predicts a greater risk of long-term hypothyroidism.

Effects of prolonged second stage, method of birth, timing of caesarean section and other obstetric risk factors on postnatal urinary incontinence: an Australian nulliparous cohort study

OBJECTIVE

To investigate the contribution of prolonged labour, method of birth, timing of caesarean section and other obstetric risk factors to postpartum urinary incontinence.

DESIGN

Prospective pregnancy cohort.

SETTING

Six metropolitan public hospitals in Victoria, Australia.

SAMPLE

A total of 1507 nulliparous women recruited to the maternal health study in early pregnancy (≤24 weeks).

METHOD

Data from hospital medical records and self-administered questionnaires/telephone interviews at ≤24 and 30-32 weeks of gestation and 3 months postpartum analysed using univariable and multivariable logistic regression.

MAIN OUTCOME MEASURE

Urinary incontinence 3 months postpartum in women continent before the index pregnancy.

RESULTS

Of the women continent before pregnancy, 26% reported new incontinence at 3 months postpartum. Compared with women who had a spontaneous vaginal birth, women who had a caesarean section before labour (adjusted odds ratio [OR] 0.2, 95% CI 0.1-0.5) or in the first stage of labour (adjusted OR 0.2, 95% CI 0.1-0.4) were less likely to be incontinent 3 months postpartum. Adjusted OR for incontinence after caesarean section in the second stage of labour compared with spontaneous vaginal birth was 0.5 (95% CI 0.2-1.0). Prolonged second stage labour was associated with increased likelihood of postpartum incontinence in women who had a spontaneous vaginal birth (adjusted OR 1.9, 95% CI 1.1-3.4) or operative vaginal birth (adjusted OR 1.7, 95% CI 1.0-2.8).

CONCLUSIONS

In addition to pregnancy itself, physiological changes associated with the second stage of labour appear to play a role in postpartum urinary incontinence.

Changes in human skeletal muscle length during stimulated eccentric muscle actions

Following eccentric exercise, increases in muscle length alter the length-tension relation of skeletal muscle. However, its unclear if this change occurs during eccentric exercise. Therefore, 70 eccentric actions of the knee extensors of one leg (with superimposed electrical stimulation) were performed at 100°/s, from full extension to full flexion. Angle-specific eccentric force was recorded throughout. Force decreased at all angles although this was non-uniform. At 70°, force decreased by 25%, whereas at 130°, force decreased by 41%. Initial peak force was recorded at 100° (590 ± 232 N); the exercise bout induced a 21% decrease in peak force and a 10° shift in the position of peak force production to 90°. The rightward shift in the muscle length-tension relation thus occurred during eccentric exercise, where greater force loss at short muscle lengths suggested an eccentric-induced over-stretching of sarcomeres.

The major genetic determinants of HIV-1 control affect HLA class I peptide presentation

Infectious and inflammatory diseases have repeatedly shown strong genetic associations within the major histocompatibility complex (MHC); however, the basis for these associations remains elusive. To define host genetic effects on the outcome of a chronic viral infection, we performed genome-wide association analysis in a multiethnic cohort of HIV-1 controllers and progressors, and we analyzed the effects of individual amino acids within the classical human leukocyte antigen (HLA) proteins. We identified >300 genome-wide significant single-nucleotide polymorphisms (SNPs) within the MHC and none elsewhere. Specific amino acids in the HLA-B peptide binding groove, as well as an independent HLA-C effect, explain the SNP associations and reconcile both protective and risk HLA alleles. These results implicate the nature of the HLA-viral peptide interaction as the major factor modulating durable control of HIV infection.

The effect of fenofibrate on HDL cholesterol and HDL particle concentration in postmenopausal women on tibolone therapy

BACKGROUND

Low high-density lipoprotein (HDL) cholesterol and particle concentration are risk factors for coronary heart disease in women. Tibolone lowers HDL cholesterol and HDL particle concentration, an effect that could be reversed by the peroxisome proliferator-activator receptor-α agonist fenofibrate.

OBJECTIVE

To assess the effects of fenofibrate on plasma HDL particles in postmenopausal women taking tibolone therapy.

DESIGN AND PARTICIPANTS

Randomized crossover study conducted in a women's health clinic. Fourteen postmenopausal women taking tibolone 2.5 mg daily for menopausal symptoms were randomized to either fenofibrate 160 mg daily or no treatment for 8 weeks, followed by a 3-week wash-out for fenofibrate and then crossed over to alternate therapy for another 8 weeks. The main outcome measure was changes in plasma HDL cholesterol concentration, apoA-I and apoA-II, LpA-I and LpA-I-A-II.

RESULTS

After 8 weeks of fenofibrate therapy, there was no change in HDL cholesterol, 1.13 ± 0.06 v 1.16 ± 0.06 mmol/l (P = 0.47) or apoA-I, 1.19 ± 0.05 v 1.20 ± 0.05 g/l (P = 0.23). LpA-I fell significantly 0.35 ± 0.03 v 0.29 ± 0.02 (P = 0.02) but there was a rise in apoA-II, 0.35 ± 0.01 v 0.39 ± 0.01 g/l (P = 0.01). There was a significant fall in total cholesterol, triglycerides, low-density lipoprotein cholesterol and apoB.

CONCLUSION

In women taking tibolone, fenofibrate increases plasma apoA-II concentration and effects a redistribution of HDL subfractions but does not correct tibolone-induced changes in HDL cholesterol or HDL particle concentration. The mechanism and significance of this require further investigation.

Postpartum thyroid dysfunction and the long-term risk of hypothyroidism: results from a 12-year follow-up study of women with and without postpartum thyroid dysfunction

BACKGROUND

The long-term risk of hypothyroidism following postpartum thyroid dysfunction (PPTD) is uncertain. Most previous studies have been small, short-term or have lacked a control group.

OBJECTIVE

To ascertain the long-term risk of hypothyroidism in women following PPTD. Design and participants A 12-year longitudinal study of 409 women (including 71 with PPTD) who previously participated in a PPTD prevalence study.

MEASUREMENTS

The primary outcome measure was hypothyroidism (defined as TSH greater than 4 mU/l or on thyroxine replacement) at follow-up. Outcomes in women with and without PPTD were compared by logistic regression. Receiver operating characteristic analysis was used to determine the optimal cut-off for baseline TSH as a predictor of hypothyroidism in the cohort.

RESULTS

At follow-up, hypothyroidism was present in 27 of 71 women who had PPTD at baseline (38%) and 14 of 338 women without PPTD (4%). From multivariate analysis, odds ratios (with 95% confidence intervals) for hypothyroidism were - 4.8 (1.6, 14.1) for PPTD; 8.2 (2.8, 24.6) for positive thyroid peroxidase antibodies (TPOAb); 9.7 (2.6, 37.0) for the hypothyroid phase of PPTD and 51.4 (19.2, 137.5) for hypothyroid PPTD with positive TPOAb. A baseline TSH above 2.6 mU/l was the optimal cut-off for predicting hypothyroidism (sensitivity 76%, specificity 86%).

CONCLUSIONS

PPTD is a strong predictor of hypothyroidism in the long-term. Women who present with postpartum hypothyroidism or have positive TPOAb are at particularly high risk, suggesting that close long-term follow-up is advisable if thyroxine replacement is not instituted at an early stage.

Effects of eccentric exercise-induced muscle damage on intramyocellular lipid concentration and high energy phosphates

Eccentric exercise is known to cause changes to the ultrastructure of skeletal muscle and, in turn, may alter the ability of the muscle to store and utilise intracellular substrates such as intramyocellular lipid (IMCL). The purpose of this study was to test the hypothesis that exercise-induced muscle damage (EIMD) results in IMCL accumulation. Six males (31 ± 6 years; mean ± SD, and 72.3 ± 9.7 kg body mass) performed 300 unilateral, maximal, isokinetic, eccentric contractions (Ecc) (30° s(-1)) of the quadriceps on an isokinetic dynamometer, followed immediately by an equal amount of work by the contralateral leg but with concentric action (Con). Phosphate compounds and IMCL content of the vastus lateralis of both legs were measured using (31)P and (1)H magnetic resonance spectroscopy. IMCL content was higher in Ecc than Con 24 h post but the reverse was evident 48 h post-exercise (P = 0.046). A significant time × trial interaction for resting [P(i)] (P = 0.045), showed increases in Ecc across time but no change in Con. A significant main effect of trial (P = 0.002) was apparent indicating the Ecc leg had marked metabolic dysfunction. The P(i)/PCr ratio showed a significant effect of trial (P = 0.001) with an increase evident in Ecc leg, primarily due to increases in [P(i)]. The present study highlights changes in IMCL content of skeletal muscle following EIMD.

Interactions between heart rate variability and pulmonary gas exchange efficiency in humans

The respiratory component of heart rate variability (respiratory sinus arrhythmia, RSA) has been associated with improved pulmonary gas exchange efficiency in humans via the apparent clustering and scattering of heart beats in time with the inspiratory and expiratory phases of alveolar ventilation, respectively. However, since human RSA causes only marginal redistribution of heart beats to inspiration, we tested the hypothesis that any association between RSA amplitude and pulmonary gas exchange efficiency may be indirect. In 11 patients with fixed-rate cardiac pacemakers and 10 healthy control subjects, we recorded R-R intervals, respiratory flow, end-tidal gas tension and the ventilatory equivalents for carbon dioxide and oxygen during 'fast' (0.25 Hz) and 'slow' paced breathing (0.10 Hz). Mean heart rate, mean arterial blood pressure, mean arterial pressure fluctuations, tidal volume, end-tidal CO(2), and were similar between pacemaker and control groups in both the fast and slow breathing conditions. Although pacemaker patients had no RSA and slow breathing was associated with a 2.5-fold RSA amplitude increase in control subjects (39 +/- 21 versus 97 +/- 45 ms, P < 0.001), comparable (main effect for breathing frequency, F(1,19) = 76.54, P < 0.001) and reductions (main effect for breathing frequency, F(1,19) = 23.90, P < 0.001) were observed for both cohorts during slow breathing. In addition, the degree of (r = 0.36, P = 0.32) and reductions (r = 0.29, P = 0.43) from fast to slow breathing were not correlated to the degree of associated RSA amplitude enhancements in control subjects. These findings suggest that the association between RSA amplitude and pulmonary gas exchange efficiency during variable-frequency paced breathing observed in prior human work is not contingent on RSA being present. Therefore, whether RSA serves an intrinsic physiological function in optimizing pulmonary gas exchange efficiency in humans requires further experimental validation.

Filaggrin loss-of-function variants are associated with atopic comorbidity in pediatric inflammatory bowel disease

BACKGROUND

Pediatric inflammatory bowel disease (IBD) has a high prevalence of coexistent atopy. Filaggrin (FLG) loss-of-function variants (null-alleles) are associated with eczema and asthma in association with eczema. The aim was to assess the contribution of FLG null-alleles to pediatric IBD susceptibility and to coexistent atopy (eczema, asthma, allergic rhinitis, or food allergy).

METHODS

FLG variants (R501X and 2282del4) were genotyped in 403 children with IBD, 683 parents, and 996 population controls.

RESULTS

In all, 11% of IBD patients carried at least 1 FLG null-allele compared to 11% of population controls (P > 0.4). Carriage of 1 or more null-alleles in patients with atopy (present in 52% of IBD patients) differed from IBD patients without atopy (14% versus 6%, P = 0.01; odds ratio [OR] 2.4, 95% confidence interval [CI] 1.2-5.1). The effect of FLG null-alleles was strongest for eczema (19% versus 7%, P = 0.0003; OR 3.3, 95% CI 1.7-6.6) and food allergy (28% versus 8%, P = 0.0001; OR 4.5, 95% CI 2.0-10.0). The presence of more than 1 atopic disease tended to increase the associated OR: eczema + asthma (23% versus 7%, P = 0.001; OR 3.9, 95% CI 1.6-9.1), eczema + asthma + allergic rhinitis (29% versus 7%, P = 0.0006; OR 5.4, 95% CI 1.9-15.4) and eczema + asthma + allergic rhinitis + food allergy (45% versus 6%, P < 10(-4); OR 12.2, 95% CI 3.2-46.3). Logistic regression analysis of IBD cases confirmed the association of carriage of an FLG null-allele with atopy (P = 0.01; OR 2.4, 95% CI 1.2-5.1) and co-occurrence of different forms of atopy (P = 0.003; OR 3.5, 95% CI 1.5-8.1).

CONCLUSIONS

Filaggrin null-alleles have no effect on IBD susceptibility but contribute to coexistent eczema and food allergy.