A Pragmatic Randomized Trial Comparing Surgical Clipping and Endovascular Treatment of Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

Surgical clipping and endovascular treatment are commonly used in patients with unruptured intracranial aneurysms. We compared the safety and efficacy of the 2 treatments in a randomized trial.

MATERIALS AND METHODS

Clipping or endovascular treatments were randomly allocated to patients with one or more 3- to 25-mm unruptured intracranial aneurysms judged treatable both ways by participating physicians. The study hypothesized that clipping would decrease the incidence of treatment failure from 13% to 4%, a composite primary outcome defined as failure of aneurysm occlusion, intracranial hemorrhage during follow-up, or residual aneurysms at 1 year, as adjudicated by a core lab. Safety outcomes included new neurologic deficits following treatment, hospitalization of >5 days, and overall morbidity and mortality (mRS > 2) at 1 year. There was no blinding.

RESULTS

Two hundred ninety-one patients were enrolled from 2010 to 2020 in 7 centers. The 1-year primary outcome, ascertainable in 290/291 (99%) patients, was reached in 13/142 (9%; 95% CI, 5%-15%) patients allocated to surgery and in 28/148 (19%; 95% CI, 13%-26%) patients allocated to endovascular treatments (relative risk: 2.07; 95% CI, 1.12-3.83; P = .021). Morbidity and mortality (mRS >2) at 1 year occurred in 3/143 and 3/148 (2%; 95% CI, 1%-6%) patients allocated to surgery and endovascular treatments, respectively. Neurologic deficits (32/143, 22%; 95% CI, 16%-30% versus 19/148, 12%; 95% CI, 8%-19%; relative risk: 1.74; 95% CI, 1.04-2.92; P = .04) and hospitalizations beyond 5 days (69/143, 48%; 95% CI, 40%-56% versus 12/148, 8%; 95% CI, 5%-14%; relative risk: 0.18; 95% CI, 0.11-0.31; P < .001) were more frequent after surgery.

CONCLUSIONS

Surgical clipping is more effective than endovascular treatment of unruptured intracranial aneurysms in terms of the frequency of the primary outcome of treatment failure. Results were mainly driven by angiographic results at 1 year.

Stent-Assisted Coiling in the Treatment of Unruptured Intracranial Aneurysms: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

Stent-assisted coiling may improve angiographic results of endovascular treatment of unruptured intracranial aneurysms compared with coiling alone, but this has never been shown in a randomized trial.

MATERIALS AND METHODS

The Stenting in the Treatment of Aneurysm Trial was an investigator-led, parallel, randomized (1:1) trial conducted in 4 university hospitals. Patients with intracranial aneurysms at risk of recurrence, defined as large aneurysms (≥10 mm), postcoiling recurrent aneurysms, or small aneurysms with a wide neck (≥4 mm), were randomly allocated to stent-assisted coiling or coiling alone. The composite primary efficacy outcome was "treatment failure," defined as initial failure to treat the aneurysm; aneurysm rupture or retreatment during follow-up; death or dependency (mRS > 2); or an angiographic residual aneurysm adjudicated by an independent core laboratory at 12 months. The primary hypothesis (revised for slow accrual) was that stent-assisted coiling would decrease treatment failures from 33% to 15%, requiring 200 patients. Primary analyses were intent to treat.

RESULTS

Of 205 patients recruited between 2011 and 2021, ninety-four were allocated to stent-assisted coiling and 111 to coiling alone. The primary outcome, ascertainable in 203 patients, was reached in 28/93 patients allocated to stent-assisted coiling (30.1%; 95% CI, 21.2%-40.6%) compared with 30/110 (27.3%; 95% CI, 19.4%-36.7%) allocated to coiling alone (relative risk = 1.10; 95% CI, 0.7-1.7; P  = .66). Poor clinical outcomes (mRS >2) occurred in 8/94 patients allocated to stent-assisted coiling (8.5%; 95% CI, 4.0%-16.6%) compared with 6/111 (5.4%; 95% CI, 2.2%-11.9%) allocated to coiling alone (relative risk = 1.6; 95% CI, 0.6%-4.4%; P  = .38).

CONCLUSIONS

The STAT trial did not show stent-assisted coiling to be superior to coiling alone for wide-neck, large, or recurrent unruptured aneurysms.

A73 EFFECT OF FECAL IMMUNOCHEMICAL TEST CUT-OFF LEVELS ON ADENOMA DETECTION RATE: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background

Adenoma detection rate (ADR) is higher after a positive fecal immunochemical test (FIT) compared to direct screening colonoscopy.

Purpose

This meta-analysis evaluated how ADR, the rates of advanced adenoma detection (AADR), colorectal cancer detection (CDR), and sessile serrated lesion detection (SSLDR) are affected by different FIT positivity thresholds.

Method

We searched MEDLINE, EMBASE, CINAHL, and EBM Reviews databases for studies reporting ADR, AADR, CDR, and SSLDR according to different FIT cut-off values in asymptomatic average-risk individuals aged 50 to 74 years old. Data were stratified according to sex, age, time to colonoscopy, publication year, continent, and FIT kit type. Study quality, heterogeneity, and publication bias were assessed.

Result(s)

Overall, 4280 articles were retrieved and fifty-seven studies were included (332,281 FIT-positive colonoscopies; mean cecal intubation 96.2%; mean age 60.7 years; male 52.1%). Mean ADR was 55.9% (95% CI 53.2% – 58.6%), while mean AADR, CDR, and SSLDR were 27.2% (95% CI 24.3% – 30.1%), 5.4% (95% CI 4.7% – 6.1%), and 3.0% (95% CI 1.7% – 4.6%), respectively. For each 20 μg Hb/g increase in FIT cut-off level, ADR increased by 2.87% (95% CI 1.70% – 4.05%, p &lt; 0.01), AADR increased by 3.90% (95% CI 2.76% – 5.05%, p &lt; 0.01) and CDR by 1.46% (95% CI 0.66% – 2.24%, p &lt; 0.01). Many detection rates were greater amongst males and Europeans.

Conclusion(s)

ADRs in FIT-positive colonoscopies are influenced by the adopted FIT positivity threshold, and identified targets, importantly, proved to be higher than most current societal recommendations.

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Disclosure of Interest

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Flow Diversion in the Treatment of Intracranial Aneurysms: A Pragmatic Randomized Care Trial

BACKGROUND AND PURPOSE

Flow diversion is a recent endovascular treatment for intracranial aneurysms. We compared the safety and efficacy of flow diversion with the alternative standard management options.

MATERIALS AND METHODS

A parallel group, prerandomized, controlled, open-label pragmatic trial was conducted in 3 Canadian centers. The trial included all patients considered for flow diversion. A Web-based platform 1:1 randomly allocated patients to flow diversion or 1 of 4 alternative standard management options (coiling with/without stent placement, parent vessel occlusion, surgical clipping, or observation) as prespecified by clinical judgment. Patients ineligible for alternative standard management options were treated with flow diversion in a registry. The primary safety outcome was death or dependency (mRS > 2) at 3 months. The composite primary efficacy outcome included the core lab-determined angiographic presence of a residual aneurysm, aneurysm rupture, progressive mass effect during follow-up, or death or dependency (mRS > 2) at 3-12 months.

RESULTS

Between May 2011 and November 2020, three hundred twenty-three patients were recruited: Two hundred seventy-eight patients (86%) had treatment randomly allocated (139 to flow diversion and 139 to alternative standard management options), and 45 (14%) received flow diversion in the registry. Patients in the randomized trial frequently had unruptured (83%), large (52% ≥10 mm) carotid (64%) aneurysms. Death or dependency at 3 months occurred in 16/138 patients who underwent flow diversion and 12/137 patients receiving alternative standard management options (relative risk, 1.33; 95% CI, 0.65-2.69; P = .439). A poor primary efficacy outcome was found in 30.9% (43/139) with flow diversion and 45.6% (62/136) of patients receiving alternative standard management options, with an absolute risk difference of 14.7% (95% CI, 3.3%-26.0%; relative risk, 0.68; 95% CI, 0.50-0.92; P = .014).

CONCLUSIONS

For patients with mostly unruptured, large, anterior circulation (carotid) aneurysms, flow diversion was more effective than the alternative standard management option in terms of angiographic outcome.

Transcranial Doppler Velocities and Angiographic Vasospasm after SAH: A Diagnostic Accuracy Study

BACKGROUND AND PURPOSE

After aneurysmal SAH, transcranial Doppler is commonly used to monitor cerebral vasospasm. The diagnostic accuracy of transcranial Doppler flow velocity values in detecting angiographic vasospasm in patients requiring urgent endovascular intervention has not been established.

MATERIALS AND METHODS

We performed a retrospective analysis of a consecutive series of patients with aneurysmal SAH who underwent transcranial Doppler (index test) within 24 hours of conventional angiography (reference test). The judgment of 33%, 50%, and 66% degree of vessel narrowing on angiography was independently established by multiple neuroendovascular clinicians. Vessel-specific per-segment and per-patient transcranial Doppler velocities were studied using receiver operating characteristic curves, the Youden index, and minimal acceptable sensitivity models. Optimal mean flow-velocity thresholds were explored to calculate sensitivity and specificity using a per-patient judgment of vasospasm of at least 50% angiographic narrowing in any large arterial segment except A1.

RESULTS

In 221 patients, vasospasm was found in 15%, 8%, and 4% of arteries when the degree of reference angiographic luminal narrowing was 33%, 50%, and 66%, respectively. Mean flow velocities were significantly higher in vasospastic segments (P = . 001), but per-segment exploratory analyses yielded unsound mean flow velocity thresholds. The Youden and minimal acceptable sensitivity models proposed mean flow velocity thresholds of approximately 160 cm/s for the anterior circulation and 80 cm/s for the posterior circulation in the per-patient diagnosis of angiographic vasospasm (≥50%), yielding a sensitivity of 80%-90% (95% CI, 0.77-0.96), but with a corresponding specificity of 50% (95% CI, 0.40-0.56).

CONCLUSIONS

In this study, a threshold transcranial Doppler mean flow-velocity value that would accurately diagnose ≥50% angiographic vasospasm remained elusive.

Sensitivity of clinician-assessed efficacy outcome measurement instruments in trials of topical therapies for atopic dermatitis: a systematic review and meta-analysis

The rising prevalence of atopic dermatitis (AD) in developing countries and its substantial socioeconomic impact have furthered research over the last two decades giving way to advances in its aetiopathogenesis and treatment. Topical therapies targeting newly identified AD signalling pathways are being developed. Numerous clinician-assessed disease severity outcome measurement instruments (OMIs) are available to evaluate the efficacy of investigational treatments in proof-of-concept (POC) trials for AD. However, little is known about the comparative sensitivity of these efficacy OMIs. We performed a systematic review and meta-analysis to compare the sensitivity of different OMIs in controlled trials of topical therapies for AD published between January 1, 2000 and April 7, 2020. Treatment effect size of OMIs reported at Week 4 was calculated with 95% Confidence Interval (CI). The sensitivity of OMIs was compared by pooling the standardized difference between means (Cohen's d and Cohen's h) for any two OMI-parameter combinations that were reported in ≥3 studies identified in our systematic review. Assessed parameters were difference between active and vehicle at Week 4 and change from baseline [CFB] and percentage change from baseline [%CFB] at Week 4. We identified a total of 15 studies with 3313 subjects examining 14 different OMIs were included in this quantitative meta-analysis. Continuous OMIs had a significantly higher treatment effect size vs. dichotomous OMIs (P = 0.006). Comparisons of Eczema Area and Severity Index (EASI), Investigator's Global Assessment (IGA), body surface area (BSA) and SCORing Atopic Dermatitis (SCORAD) for available parameters were performed and generally had a similar sensitivity, with BSA showing smaller overall effect size estimates. In conclusion, continuous OMIs used in topical clinical trials for AD had significantly higher treatment effect sizes when compared to dichotomous OMIs. Continuous OMIs could provide more power for POC trials with a small sample size in atopic dermatitis with topical therapies.

Reliability of the Diagnosis of Cerebral Vasospasm Using Catheter Cerebral Angiography: A Systematic Review and Inter- and Intraobserver Study

BACKGROUND AND PURPOSE

Conventional angiography is the benchmark examination to diagnose cerebral vasospasm, but there is limited evidence regarding its reliability. Our goals were the following: 1) to systematically review the literature on the reliability of the diagnosis of cerebral vasospasm using conventional angiography, and 2) to perform an agreement study among clinicians who perform endovascular treatment.

MATERIALS AND METHODS

Articles reporting a classification system on the degree of cerebral vasospasm on conventional angiography were systematically searched, and agreement studies were identified. We assembled a portfolio of 221 cases of patients with subarachnoid hemorrhage and asked 17 raters with different backgrounds (radiology, neurosurgery, or neurology) and experience (junior ≤10 and senior >10 years) to independently evaluate cerebral vasospasm in 7 vessel segments using a 3-point scale and to evaluate, for each case, whether findings would justify endovascular treatment. Nine raters took part in the intraobserver reliability study.

RESULTS

The systematic review showed a very heterogeneous literature, with 140 studies using 60 different nomenclatures and 21 different thresholds to define cerebral vasospasm, and 5 interobserver studies reporting a wide range of reliability (κ = 0.14-0.87). In our study, only senior raters reached substantial agreement (κ ≥ 0.6) on vasospasm of the supraclinoid ICA, M1, and basilar segments and only when assessments were dichotomized (presence or absence of ≥50% narrowing). Agreement on whether to proceed with endovascular management of vasospasm was only fair (κ ≤ 0.4).

CONCLUSIONS

Research on cerebral vasospasm would benefit from standardization of definitions and thresholds. Dichotomized decisions by experienced readers are required for the reliable angiographic diagnosis of cerebral vasospasm.

Reliability of CT Angiography in Cerebral Vasospasm: A Systematic Review of the Literature and an Inter- and Intraobserver Study

BACKGROUND AND PURPOSE

Computed tomography angiography offers a non-invasive alternative to DSA for the assessment of cerebral vasospasm following subarachnoid hemorrhage but there is limited evidence regarding its reliability. Our aim was to perform a systematic review (Part I) and to assess (Part II) the inter- and intraobserver reliability of CTA in the diagnosis of cerebral vasospasm.

MATERIALS AND METHODS

In Part I, articles reporting the reliability of CTA up to May 2018 were systematically searched and evaluated. In Part II, 11 raters independently graded 17 arterial segments in each of 50 patients with SAH for the presence of vasospasm using a 4-category scale. Raters were additionally asked to judge the presence of any moderate/severe vasospasm (≥ 50% narrowing) and whether findings would justify augmentation of medical treatment or conventional angiography ± balloon angioplasty. Four raters took part in the intraobserver reliability study.

RESULTS

In Part I, the systematic review revealed few studies with heterogeneous vasospasm definitions. In Part II, we found interrater reliability to be moderate at best (κ ≤ 0.6), even when results were stratified according to specialty and experience. Intrarater reliability was substantial (κ > 0.6) in 3/4 readers. In the per arterial segment analysis, substantial agreement was reached only for the middle cerebral arteries, and only when senior raters' judgments were dichotomized (presence or absence of ≥50% narrowing). Agreement on the medical or angiographic management of vasospasm based on CTA alone was less than substantial (κ ≤ 0.6).

CONCLUSIONS

The diagnosis of vasospasm using CTA alone was not sufficiently repeatable among observers to support its general use to guide decisions in the clinical management of patients with SAH.

Does Increasing Packing Density Using Larger Caliber Coils Improve Angiographic Results of Embolization of Intracranial Aneurysms at 1 Year: A Randomized Trial

BACKGROUND AND PURPOSE

The impact of increased aneurysm packing density on angiographic outcomes has not been studied in a randomized trial. We sought to determine the potential for larger caliber coils to achieve higher packing densities and to improve the angiographic results of embolization of intracranial aneurysms at 1 year.

MATERIALS AND METHODS

Does Embolization with Larger Coils Lead to Better Treatment of Aneurysms (DELTA) was an investigator-initiated multicenter prospective, parallel, randomized, controlled clinical trial. Patients had 4- to 12-mm unruptured aneurysms. Treatment allocation to either 15- (experimental) or 10-caliber coils (control group) was randomized 1:1 using a Web-based platform. The primary efficacy outcome was a major recurrence or a residual aneurysm at follow-up angiography at 12 ± 2 months adjudicated by an independent core lab blinded to the treatment allocation. Secondary outcomes included indices of treatment success and standard safety outcomes. Recruitment of 564 patients was judged necessary to show a decrease in poor outcomes from 33% to 20% with 15-caliber coils.

RESULTS

Funding was interrupted and the trial was stopped after 210 patients were recruited between November 2013 and June 2017. On an intent-to-treat analysis, the primary outcome was reached in 37 patients allocated to 15-caliber coils and 36 patients allocated to 10-caliber coils (OR = 0.931; 95% CI, 0.528-1.644; P = .885). Safety and other clinical outcomes were similar. The 15-caliber coil group had a higher mean packing density (37.0% versus 26.9%, P = .0001). Packing density had no effect on the primary outcome when adjusted for initial angiographic results (OR = 1.001; 95% CI, 0.981-1.022; P = .879).

CONCLUSIONS

Coiling of aneurysms randomized to 15-caliber coils achieved higher packing densities compared with 10-caliber coils, but this had no impact on the angiographic outcomes at 1 year, which were primarily driven by aneurysm size and initial angiographic results.

Intravenous thrombolysis and thrombectomy decisions in acute ischemic stroke: An interrater and intrarater agreement study

PURPOSE

We aimed to assess agreement on intravenous tissue-plasminogen activator (IV tPA) and mechanical thrombectomy (MT) management decisions in acute ischemic stroke (AIS) patients. Secondary objectives were to assess agreement on Diffusion-Weighted-Imaging-Alberta-Stroke-Program-EArly-CT-Score (DWI-ASPECTS), and clinicians' willingness to recruit patients in a randomized controlled trial (RCT) comparing medical management with or without MT.

MATERIALS AND METHODS

Studies assessing agreement of IV tPA and MT were systematically reviewed. An electronic portfolio of 41 AIS patients was sent to randomly selected providers at French stroke centers. Raters were asked 4 questions for each case: (1) What is the DWI-ASPECTS? (2) Would you perform IV tPA? (3) Would you perform MT? (4) Would you include the patient in a RCT comparing standard medical therapy with or without MT? Twenty responders were randomly selected to study intrarater agreement. Agreement was assessed using Fleiss' Kappa statistics.

RESULTS

The review yielded two single center studies involving 2-5 raters, with various results. The electronic survey was answered by 86 physicians (60 vascular neurologists and 26 interventional neuroradiologists). The interrater agreement was moderate for IV tPA treatment decisions (κ=0.565 [0.420-0.680]), but only fair for MT (κ=0.383 [0.289-0.491]) and for combined treatment decisions (κ=0.399 [0.320-0.486]). The intrarater agreement was at least substantial for the majority of raters. The interrater agreement for DWI-ASPECTS was fair (κ=0.325 [0.276-0.387]). Physicians were willing to include a mean of 14±9 patients (33.1%±21.7%) in a RCT.

CONCLUSION

Disagreements regarding the use of IVtPA or MT in the management of AIS patients remain frequent. Further trials are needed to resolve the numerous areas of uncertainty.

Monitoring the efficacy of omega-3 supplementation on liver steatosis and carotid intima-media thickness: a pilot study

Purpose

To determine the effects of omega‐3 supplementation on liver fat and carotid intima–media thickness (IMT) and to assess accuracy of ultrasound (US) for grading liver steatosis.

Materials and Methods

In this one‐way crossover pilot study, we assigned children with obesity and liver steatosis to receive 1.2 g daily of omega‐3 supplementation vs. inactive sunflower oil for 24 or 12 weeks. Liver fat content was assessed by magnetic resonance spectroscopy (MRS), magnetic resonance imaging (MRI) and US, and common carotid IMT by US. Statistical analysis included Chi‐square, Student's t‐tests, ANOVA tests and receiver operating characteristic (ROC) curves.

Results

Omega‐3 supplementation was associated with a trend towards decrease in MRS‐determined liver fat fraction (0.7% and 2.1% decrease in the 24‐week and 12‐week omega‐3 group, respectively) compared with the sunflower oil group (1.0% increase). These changes were not significant, whether assessed by MRS (P = 0.508), MRI (P = 0.508) or US (P = 0.678). Using US, the area under the ROC curves were 0.964, 0.817 and 0.783 for distinguishing inferred steatosis grades 0 vs. 1–2–3, 0–1 vs. 2–3 and 0–1–2 vs. 3, respectively, indicating good accuracy of US‐based fat grading. Omega‐3 supplementation was associated with a decrease in US‐determined IMT (0.05‐mm decrease in the 24‐week omega‐3 group. A 0.015‐mm increase was found in the 12‐week omega‐3 group, and a 0.007‐mm decrease in the sunflower oil group (P = 0.003).

Conclusion

Omega‐3 supplementation had no significant effect on liver fat fraction, but led to carotid IMT decrease in children with obesity and liver steatosis.

Hydrogel versus Bare Platinum Coils in Patients with Large or Recurrent Aneurysms Prone to Recurrence after Endovascular Treatment: A Randomized Controlled Trial

BACKGROUND AND PURPOSE

Some patients are at high risk of aneurysm recurrence after endovascular treatment: patients with large aneurysms (Patients Prone to Recurrence After Endovascular Treatment PRET-1) or with aneurysms that have previously recurred after coiling (PRET-2). We aimed to establish whether the use of hydrogel coils improved efficacy outcomes compared with bare platinum coils.

MATERIALS AND METHODS

PRET was an investigator-led, pragmatic, multicenter, parallel, randomized (1:1) trial. Randomized allocation was performed separately for patients in PRET-1 and PRET-2, by using a Web-based platform ensuring concealed allocation. The primary outcome was a composite of a residual/recurrent aneurysm, adjudicated by a blinded core laboratory, or retreatment, intracranial bleeding, or mass effect during the 18-month follow-up. Secondary outcomes included adverse events, mortality, and morbidity (mRS > 2). The hypothesis was that hydrogel would decrease the primary outcome from 50% to 30% at 18 months, necessitating 125 patients per group (500 for PRET-1 and PRET-2).

RESULTS

The trial was stopped once 250 patients in PRET-1 and 197 in PRET-2 had been recruited because of slow accrual. A poor primary outcome occurred in 44.4% (95% CI, 35.5%-53.2%) of those in PRET-1 allocated to platinum compared with 52.5% (95% CI, 43.4%-61.6%) of patients allocated to hydrogel (OR, 1.387; 95% CI, 0.838-2.295; P = .20) and in 49.0% (95% CI, 38.8%-59.1%) in PRET-2 allocated to platinum compared with 42.1% (95% CI, 32.0%-52.2%) allocated to hydrogel (OR, 0.959; 95% CI, 0.428-1.342; P = .34). Adverse events and morbidity were similar. There were 3.6% deaths (1.4% platinum, 5.9% hydrogel; P = .011).

CONCLUSIONS

Coiling of large and recurrent aneurysms is safe but often poorly effective according to angiographic results. Hydrogel coiling was not shown to be better than platinum.

Inter- and Intrarater Agreement on the Outcome of Endovascular Treatment of Aneurysms Using MRA

BACKGROUND AND PURPOSE

Patients treated with coiling are often followed by MR angiography. Our objective was to assess the inter- and intraobserver agreement in diagnosing aneurysm remnants and recurrences by using multimodality imaging, including TOF MRA.

MATERIALS AND METHODS

A portfolio composed of 120 selected images from 56 patients was sent to 15 neuroradiologists from 10 institutions. For each case, raters were asked to classify angiographic results (3 classes) of 2 studies (32 MRA-MRA and 24 DSA-MRA pairs) and to provide a final judgment regarding the presence of a recurrence (no, minor, major). Six raters were asked to independently review the portfolio twice. A second study, restricted to 4 raters having full access to all images, was designed to validate the results of the electronic survey.

RESULTS

The proportion of cases judged to have a major recurrence varied between 16.1% and 71.4% (mean, 35.0% ± 12.7%). There was moderate agreement overall (κ = 0.474 ± 0.009), increasing to nearly substantial (κ = 0.581 ± 0.014) when the judgment was dichotomized (presence or absence of a major recurrence). Agreement on cases followed-up by MRA-MRA was similarly substantial (κ = 0.601 ± 0.018). The intrarater agreement varied between fair (κ = 0.257 ± 0.093) and substantial (κ= 0.699 ± 0.084), improving with a dichotomized judgment concerning MRA-MRA comparisons. Agreement was no better when raters had access to all images.

CONCLUSIONS

There is an important variability in the assessment of angiographic outcomes of endovascular treatments. Agreement on the presence of a major recurrence when comparing 2 MRA studies or the MRA with the last catheter angiographic study can be substantial.

Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites

Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time-depending on the plant, its growth stage, and the amount of pesticide applied. A wide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.

Patients prone to recurrence after endovascular treatment: periprocedural results of the PRET randomized trial on large and recurrent aneurysms

BACKGROUND AND PURPOSE

Some patients with large or recurrent aneurysms may be at increased risk of recurrence postcoiling. The Patients Prone to Recurrence after Endovascular Treatment (PRET) trial was designed to assess whether hydrogel coils were superior to platinum coils in these high-risk patients. This article reports periprocedural safety and operator-assessed angiographic results from the PRET trial.

MATERIALS AND METHODS

PRET was a pragmatic, multicenter, randomized controlled trial. Patients had ≥10-mm aneurysms (PRET-1) or a major recurrence after coiling of an aneurysm of any size (PRET-2). Patients were randomly allocated to hydrogel or control arms (any platinum coil) by using concealed allocation with minimization. Assist devices could be used as clinically required. Aneurysms could be unruptured or recently ruptured. Analyses were on an intent-to-treat basis.

RESULTS

Four hundred forty-seven patients were recruited (250 PRET-1; 197 PRET-2). Aneurysms were recently ruptured in 29% of PRET-1 and 4% of PRET-2 patients. Aneurysms were ≥10 mm in all PRET-1 and in 50% of PRET-2 patients. They were wide-neck (≥4 mm) in 70% and in the posterior circulation in 24% of patients. Stents were used in 28% of patients (35% in PRET-2). Coiling was successful in 98%. Adverse events occurred in 28 patients with hydrogel and 23 with platinum coils. Mortality (n=2, unrelated to treatment) and morbidity (defined as mRS>2 at 1 month) occurred in 25 patients (5.6%; 12 hydrogel, 13 platinum), related to treatment in 10 (4 hydrogel; 6 platinum) (or 2.3% of 444 treated patients). No difference was seen between hydrogel and platinum for any of the indices used to assess safety up to at least 30 days after treatment. At 1 month, 95% of patients were home with a good outcome (mRS≤2 or unchanged). Operator-assessed angiographic outcomes were satisfactory (complete occlusion or residual neck) in 339 of 447 or 76.4% of patients, with no significant difference between groups.

CONCLUSIONS

Endovascular treatment of large and recurrent aneurysms can be performed safely with platinum or hydrogel coils.

Inter- and intraobserver agreement in scoring angiographic results of intra-arterial stroke therapy

BACKGROUND AND PURPOSE

Angiographic results are commonly used as surrogate markers of the success of intra-arterial therapies for acute stroke. Inter- and intraobserver agreement in judging angiographic results remain poorly characterized. Our goal was to assess 2 commonly used revascularization scales.

MATERIALS AND METHODS

A portfolio of 148 pre- and post treatment images of 37 cases of proximal anterior circulation occlusions was electronically sent to 12 expert observers who were asked to grade treatment outcomes according to recanalization (of arterial occlusive lesion) or reperfusion (TICI) scales. Three expert observers had to score treatment outcomes by using a similar portfolio of 32 patients or when they had full access to all angiographic data, twice for each method 3-12 months apart. Results were analyzed by using κ statistics.

RESULTS

Agreement among 9 responding observers was moderate for both the TICI (κ = 0.45 ± 0.01) and arterial occlusive lesion (κ = 0.39 ± 0.16) scales. Agreement was similar (moderate) when 3 observers had access to a portfolio (κ = 0.59 ± 0.06 and 0.49 ± 0.07, respectively) or to the full angiographic data (κ = 0.54 ± 0.06 and 0.59 ± 0.07, respectively). Intraobserver agreement was "fair to moderate" for both methods. Interobserver agreement became "substantial" (>0.6) when outcomes were dichotomized into "success" (TICI 2b, 3; arterial occlusive lesion II, III or "failure"; the results were judged more favorably when the arterial occlusive lesion rather than the TICI scale was used.

CONCLUSIONS

There is an important variability in the assessment of angiographic outcomes of endovascular treatments, invalidating comparisons among publications. A simple dichotomous judgment can be used as a surrogate outcome when treatments are assessed by the same observers in randomized trials.

Pollen loads and specificity of native pollinators of lowbush blueberry

The reproduction of lowbush blueberry (Vaccinium angustifolium Aiton) is closely tied to insect pollination, owing to self-incompatibility. Many species are known to have greater pollination efficiency than the introduced Apis mellifera L., commonly used for commercial purposes. In this study, we measured the pollen loads of several antophilous insect species, mostly Apoidea and Syrphidae, present in four lowbush blueberry fields in Lac-St-Jean, Québec. To measure pollen loads and species specificity toward V. angustifolium, we net-collected 627 specimens of pollinators, retrieved their pollen loads, identified pollen taxa, and counted pollen grains. We found that the sizes of pollen loads were highly variable among species, ranging from a few hundred to more than 118,000 pollen grains per individual. Bombus and Andrena species in particular carried large amounts of Vaccinium pollen and thus may have greater pollination efficiency. Also, two species (Andrena bradleyi Viereck and Andrena carolina Viereck) showed nearly monolectic behavior toward lowbush blueberry. Finally, we identified alternative forage plants visited by native pollinators, notably species of Acer, Rubus, Ilex mucronata, Ledum groenlandicum, and Taraxacum. Protecting these flowering plants should be part of management practices to maintain healthy pollinator communities in a lowbush blueberry agroecosystem.

Relation BetweenBglIIPolymorphism in 3β-Hydroxysteroid Dehydrogenase Gene and Adipose Tissue Distribution in Humans

The aim of this study was to investigate the association between a restriction fragment length polymorphism (RFLP) at the 3beta-hydroxysteroid dehydrogenase locus and adipose tissue distribution phenotypes. A total of 132 unrelated individuals from the Quebec Family Study were followed prospectively for an average period of 11.3 years. The BglII polymorphism in exon 4 of the 3beta-HSD gene was detected by PCR. Body mass, body fat, and regional fat distribution indicators were adjusted for age and age2 within each gender. Associations were assessed in unrelated adults with ANOVA across three genotypes. No association was found for the indicators of body mass, body fat, and regional distribution of adipose tissue measured in 1992. In women, the changes (difference between data collected in 1992 and at entry) in the sum of six skinfolds (p=0.04), abdominal skinfold (p=0.01), and abdominal skinfold adjusted (p=0.03) for the sum of six skinfolds at entry were related to the BglII polymorphism at the 3beta-HSD locus. These relations were not found in men, but they gained less body mass and body fat over the 11.3-year period. This suggests that sequence variation at the 3beta-HSD locus or in neighboring genes on chromosome 1 may contribute to individual differences in body fat content and adipose tissue distribution in adult women, particularly in abdominal adipose tissue deposition as they grow older and gain body fat.

Comparison of different methods of inter-eye asymmetry of rim area and disc area analysis

PURPOSE

To describe different methods of inter-eye asymmetry of rim area (RA) to disc area (DA) asymmetry ratio (RADAAR) analysis.

METHODS

This was an observational, descriptive, and cross-sectional study. Both the eyes of all participants underwent confocal scanning laser ophthalmoscopy (Heidelberg retina tomograph (HRT 3)), frequency-doubling technology perimetry (FDT), and complete ophthalmological examination. Based on ophthalmological clinical examination and FDT results of the worse eye, subjects were classified as either normal, possible glaucoma, and probable glaucoma or definitive glaucoma. RADAAR values were calculated based on stereometric HRT 3 values using different mathematical formulae. RADAAR-1 was calculated as a relative difference of rim and DAs between the eyes. RADAAR-2 was calculated by subtracting the value of rim to DA ratio of the smaller disc from the value of rim to DA ratio of the larger disc. RADAAR-3 was calculated by dividing the previous two values. Statistical analyses included ANOVA as well as Student t-tests.

RESULTS

Data of 334 participants were analysed, 78 of which were classified as definitive glaucoma. RADAAR-1 values were significantly different between the four different groups of diagnosis (F=5.82; P<0.001). The 1st and 99th percentile limits of normality for RADAAR-1, RADAAR-2, and RADAAR-3 in normal group were, respectively, -10.64 and 8.4; -0.32 and 0.22; and 0.58 and 1.32.

CONCLUSIONS

RADAAR-1 seems to best distinguish between the diagnostic groups. Knowledge of RADAAR distribution in various diagnostic groups may aid in clinical diagnosis of asymmetric glaucomatous damage.

Unruptured Intracranial Aneurysms. Opinions of Experts in Endovascular Treatment Are Coherent,Weighted in Favour of Treatment, and Incompatible with ISUIA

SUMMARY

In the absence of level one evidence, the treatment of unruptured intracranial aneurysms is grounded on opinions. Results of the largest registry available, ISUIA (the International Study on Unruptured Intraacranial Aneurysms) suggest that surgical or endovascular treatments are rarely justified. Yet the unruptured aneurysm is the most frequent indication for treatment in many endovascular centres. In preparation for the initiation of a randomized trial, we aimed at a better knowledge of endovascular expert opinions on unruptured aneurysms. We administered a standard questionnaire to 175 endovascular experts gathered at the WFITN meeting in Val d'Isère in 2007. Four paradigm unruptured aneurysms were used to poll opinions on risks of treatment or observation, as well as on their willingness to treat, observe or propose to the patient participation in a randomized trial, using six questions for each aneurysm. Opinions varied widely among lesions and among participants. Most participants (92.5%) were consistent, as they would offer treatment only if their estimate of the ten-year risk of spontaneous hemorrhage would exceed risks of treatment. Estimates of the natural history were consistently higher than that reported by ISUIA. Conversely, treatment risks were underestimated compared to those reported in ISUIA, but within the range reported in a recent French registry (ATENA). Participants were more confident in their evaluation of treatment risks and in their skills at treating aneurysms than in their estimates of risks of rupture entailed by the presence of the lesion, the latter being anchored at or close to 1%/year. The gulf between expert opinions, clinical practices and available data from registries persist. Expert opinions are compatible with the primary hypothesis of a recently initiated randomized trial on unruptured aneurysms (TEAM), which is a benefit of endovascular treatment of 4% compared to observation over ten years.Only data from a randomized trial could provide convincing objective evidence in favour or against preventive treatment of unruptured intracranial aneurysms.

Kinin-dependent hypersensitivity reactions in hemodialysis: metabolic and genetic factors

Although the association of angiotensin I-converting enzyme inhibitors (ACEis) with a negatively charged membrane is thought to be responsible for hypersensitivity reactions (HSRs) during hemodialysis, we hypothesize that these complications are due to changes in plasma aminopeptidase P (APP) activity and genotype. To test this hypothesis, we measured plasma APP activity in 14 patients who suffered HSR (HSR+) while dialyzed with an AN69 membrane and simultaneously treated with an ACEi. APP activity was also studied in a control group (n=39) dialyzed under the same conditions, but who did not suffer any side effect (HSR-). We found significantly decreased plasma APP activity (P=0.013) in HSR+ subjects as well as altered degradation of endogenous des-Arginine(9)-bradykinin, with a significantly lower beta value (P<0.001). The same analytical approach was taken in 171 relatives of HSR+ patients. Variance component analysis suggested that genetic differences may explain 61% of the phenotypic variability of plasma APP activity (P<0.001) and the kinetic parameters that characterized kinin degradation. We also showed that the C-2399A single-nucleotide polymorphism at the XPNPEP2 locus was a significant predictor of APP activity in the 39 HSR- controls (P=0.029). Furthermore, a recessive genetic model for the A allele disclosed a significant difference in mean APP activity by genotype (P<0.001). Finally, our study defined the nonspecific inhibition of recombinant APP by some ACEis. In conclusion, this paper highlights the complexity of HSR in hemodialysis, suggesting, as with angioedema, that these rare, but life-threatening adverse events are governed by several metabolic and genetic factors.

Substrate-trapping techniques in the identification of cellular PTP targets

Tyrosine phosphorylation is negatively regulated by the protein-tyrosine phosphatases (PTPs). In order to find the physiological substrates of these enzymes, diverse PTP mutants that do not possess any catalytic activities but appear to bind tightly to their tyrosine phosphorylated substrates have been designed. Hence, they can be used as tools to pull out their respective substrates from heterogeneous extracts. Named PTP "substrate-trapping" mutants by the Tonks laboratory, they represent a diverse variety of defective PTPs that are epitomized by the Cys to Ser mutant (C/S) where the active cysteine residue of the signature motif is mutated to a serine residue. In addition, new mutants have been developed which are expected to help characterize novel and less abundant substrates. In this article, we review and describe all the different substrate-trapping mutants that have successfully been used or that hold interesting promises. We present their methodology to identify substrates in vivo (co-immunoprecipitation) and in vitro (GST pulldown), and provide a current list of substrates that have been identified using these technologies.

New Devices Designed to Improve the Long-Term Results of Endovascular Treatment of Intracranial Aneurysms. A Proposition for a Randomized Clinical Trial to Assess their Safety and Efficacy

SUMMARY

Endovascular coiling can improve the outcome of patients with ruptured intracranial aneurysms, but angiographic recurrences are frequent compared to surgical clipping. New coils or devices have been introduced to improve long-term results of endovascular treatment but none have been the object of a valid clinical trial. We have proposed a multicentric randomized double-blind study comparing radioactive and standard coil occlusion of aneurysms. The purpose of this article is to review issues that are specific to the design of clinical trials to assess embolic agents that could improve the long-term efficacy of endovascular treatment of intracranial aneurysms. The proposed trial is a randomized, multi-center, prospective, controlled trial comparing the new generation coils to standard platinum coils. Blinding, if at all possible, is preferable to minimize bias, at least for follow-up angiographic studies that should cover a period of 18 months. All patients with an intracranial aneurysm eligible for endovascular treatment would be proposed to participate. The study would enrol approximately 500 patients equally divided between the two groups, recruited within two years, to demonstrate a decrease in the recurrence rate, the primary outcome measure, from 20% to 10%. Secondary outcome measures should assure that complications, initial clinical and angiographic results remain unchanged. Independent data safety and monitoring committees are crucial to the credibility of trials and to ensure scientific rigor and objectivity. The scientific demonstration of an improved long-term efficacy, without significant compromise regarding safety, is mandatory before considering the widespread use of a new embolic device for the endovascular treatment of aneurysms.

A randomized trial on the safety and efficacy of endovascular treatment of unruptured intracranial aneurysms is feasible

SUMMARY

The safety and efficacy of endovascular treatment of unruptured intracranial aneurysms remain undetermined. A randomized trial may be the best way to demonstrate the potential benefits of endovascular management. We propose a randomized, prospective, controlled trial comparing the incidence of subarachnoid haemorrage of patients treated by endovascular coiling as compared to conservative management. We would also study a composite outcome combining SAH and the morbidity of treatment. All patients with one or more unruptured aneurysm >> 3 mm eligible for endovascular treatment would be proposed to participate. The study would be conducted in 40-50 centres. The entire study would enrol 1800 patients, recruited over three years and followed for five years, but would be preceded by a feasibility study on 200 patients. A randomized trial comparing endovascular and conservative treatment could have an important impact on the clinical management of intracranial aneurysms.

Genetic variation at the adipsin locus and response to long-term overfeeding

OBJECTIVES

The role of adipsin and adipsin Hinc II polymorphisms on the metabolic and body composition changes in response to overfeeding was studied.

SUBJECTS

A total of 12 pairs of male monozygotic twins ate a 4.2 MJ/day energy surplus, 6 days a week, during a period of 100 days.

RESULTS

The preoverfeeding plasma adipsin concentration correlated positively with the change in CT-measured abdominal total and subcutaneous (P<0.05) fat. The changes in abdominal total fat and abdominal subcutaneous fat correlated negatively with changes in plasma adipsin concentrations (P<0.005). Overfeeding induced greater increases in body weight, fat mass, abdominal total and subcutaneous fat (P<0.05) in 6.1 kb noncarriers (n=10) than in 6.1 kb carriers (n=14) of the adipsin Hinc II polymorphism. The 6.1 kb noncarriers had a greater increase in plasma leptin levels (P<0.01). Also the total (P<0.01) and very-low-density lipoprotein (VLDL)-triglycerides (P<0.05), apolipoprotein B (P<0.05) and VLDL-cholesterol (P<0.05) levels increased more in the 6.1 kb noncarriers than in the 6.1 kb carriers.

CONCLUSIONS

Adipsin plasma level could be a predictor of the changes in abdominal subcutaneous fat during times of increased energy intake. However, a greater increase in the abdominal subcutaneous fat was related to a lower increase in the plasma adipsin level. The adipsin Hinc II 6.1 kb allele noncarriers gained more abdominal subcutaneous fat and had a greater increase in plasma levels of leptin- and triglyceride-rich lipoproteins when exposed to a long-term positive energy balance. These findings provide new information on the role of adipsin on individual differences in response to chronically elevated food intake.

Genetic factors as predictors of weight gain in young adult Dutch men and women

OBJECTIVE

To investigate the association between DNA polymorphisms in several candidate genes for obesity and weight gain. Polymorphisms in these genes may contribute to weight gain through effects on energy intake, energy expenditure or adipogenesis.

DESIGN AND METHODS

From two large cohorts in The Netherlands (total 17,500 adult men and women), we compared 286 subjects aged 20-40 y who gained an average of 12.8 kg (range 5.5-47 kg) during a mean follow-up of 6.8 y with 296 subjects who remained relatively constant over the same period with respect to occurrence of several polymorphisms in candidate genes of obesity and some lifestyle factors. Subjects who were dieting, were high alcohol consumers, were pregnant, changed their smoking status recently, or those who suffered from serious illnesses were excluded. Polymorphisms were determined in the LEPR-gene (LEPR Lys109Arg, LEPR Gln223Arg, LEPR Lys656Asn), in the UCP1 gene (A-G mutation at position-3826 5' region), in the UCP2 gene (Ala55Val, 45 bp Ins/Del), in the PPARG2 gene (Pro12Ala) and in the ADRB2 gene (Gly16Arg and Gln27Glu).

RESULTS

With the exception of the Gly16Arg polymorphism in the ADRB2 gene in men (P = 0.04) and women (P = 0.05), and the Lys109Arg polymorphism in the LEPR gene in women, no statistically significant differences in the genotype and allele frequencies were observed between weight gainers and non-weight gainers. Weight gainers differed in some aspects of dietary habits and physical activity patterns: weight gainers consumed relatively more savory snacks and were less active during leisure time compared with non-weight gainers.

CONCLUSION

Only variations in the ADRB2 gene and LEPR gene, may contribute to susceptibility to weight gain. None of the other studied genetic markers were clearly associated with weight gain. Further research is necessary to establish the role of lifestyle factors, or interactions between genes or between genes and lifestyle factors on weight gain with age.

Polymorphisms in the leptin receptor gene, body composition and fat distribution in overweight and obese women

OBJECTIVE

Leptin is an adipocyte-secreted hormone involved in body weight regulation, acting through the leptin receptor, localised centrally in the hypothalamus as well as peripherally, amongst others on adipose tissue. The aim of this study was to evaluate whether polymorphisms in the leptin receptor (LEPR) gene were related to obesity and body fat distribution phenotypes, such as waist and hip circumferences and the amount of visceral and subcutaneous fat.

METHODS

Three known LEPR polymorphisms, Lys109Arg, Gln223Arg and Lys656Asn, were typed on genomic DNA of 280 overweight and obese women (body mass index (BMI)>25), aged 18-60 y. General linear model (GLM) analyses were performed in 198 pre- and 82 postmenopausal women, adjusting the data for age and menopausal state, plus fat mass for the fat distribution phenotypes.

RESULTS

No associations were found between the LEPR polymorphisms and BMI or fat mass. In postmenopausal women, carriers of the Asn656 allele had increased hip circumference (P=0.03), total abdominal fat (P=0.03) and subcutaneous fat (P=0.04) measured by CT scan. Total abdominal fat was also higher in Gln223Gln homozygotes (P=0.04). Also in postmenopausal women, leptin levels were higher in Lys109Lys homozygotes (P=0.02).

CONCLUSION

In conclusion, polymorphisms in the leptin receptor gene are associated with levels of abdominal fat in postmenopausal overweight women. Since body fat distribution variables were adjusted for fat mass, these results suggest that DNA sequence variations in the leptin receptor gene play a role in fat topography and may be involved in the predisposition to abdominal obesity.

A missense mutation in the human melanocortin-4 receptor gene in relation to abdominal obesity and salivary cortisol

AIMS/HYPOTHESIS

The melanocortin-4 receptor (MC4-R) regulates food intake and possibly energy expenditure, and the inactivation of the MC4-R by gene targeting results in obesity, a phenotype strongly associated with Type II (non-insulin-dependent) diabetes mellitus. In our study, we addressed the hypothesis that a G-->A substitution at codon 103 (Val-103Ile) of the MC4R gene influences abdominal obesity, insulin, glucose, and lipid metabolism as well as circulating hormones, including salivary cortisol.

METHODS

We genotyped the missense variant at codon 103 of the MC4R gene in 284 unrelated Swedish men born in 1944 by using polymerase chain reaction amplification followed by digestion with the restriction enzyme HincII.

RESULTS

The frequency of allele G was 0.97 and 0.03 for allele A. The observed genotype frequencies were 95 % and 5 % for G/G and G/A, respectively. The heterozygotes had lower waist-to-hip ratio (p = 0.023) and trends for lower body mass index (p = 0.054) and abdominal sagittal diameter (p = 0.095) compared to G/G homozygotes. Moreover, G/A subjects had borderline lower serum leptin concentrations (p = 0.087) and total cholesterol (p = 0.082). The heterozygotes had also, in comparison to G/G subjects, significantly (p < 0.01) higher mean cortisol concentrations in the morning (21.4 vs 14.6 nmol/l), at ll:45 h (11.6 vs 7.0 nmol/l), 30 min after a standardized lunch (15.3 vs 8.0 nmol/l) and finally, 60 min after lunch (10.8 vs 6.7 nmol/l).

CONCLUSION/INTERPRETATION

These findings suggest that the missense mutation in the MC4R gene could contribute to the variability in body mass, abdominal fat distribution and leptin concentrations in the general population. Moreover, the G/A mutation exhibits evidence of associations with diurnal cortisol levels.

A polymorphism in the regulatory region of the corticotropin-releasing hormone gene in relation to cortisol secretion, obesity, and gene-gene interaction

In recent years, a considerable body of evidence has emerged regarding the pathogenic role of cortisol in abdominal obesity. The regulation of the corticotropin-releasing hormone (CRH) gene might play an essential role because it is the primary hypothalamic neuropeptide involved in the control of adrenal secretion of cortisol. Therefore, we examined the hypothalamic-pituitary-adrenal function by repeated salivary samples for the assessment of cortisol as well as other endocrine, anthropometric, metabolic, and circulatory variables in middle-aged Swedish men (n = 284). With the restriction enzyme XmnI, a variant in the 5'-flanking region of the CRH gene was identified (T255G). The observed genotype frequencies were 89.9% and 9.7% for T/T and T/G, respectively. Only 1 subject was homozygous for the rare allele (0.4%; G/G). The results showed that the XmnI polymorphism of the CRH gene is not associated with an altered cortisol-secretory pattern or sensitivity to glucocorticoids or with obesity and its related metabolic and circulatory perturbations. However, when the interaction effect between a previously described TthlllI glucocorticoid-receptor gene polymorphism and the present XmnI CRH polymorphism was investigated, the cortisol levels before and during physiologic stress and the total diurnal cortisol secretion were significantly increased among subjects who were carriers for both variants. From these results, we conclude that an abnormal production rate of the CRH gene product in the presence of an inadequate glucocorticoid receptor density might lead to elevated cortisol levels.

Mutations in the preproghrelin/ghrelin gene associated with obesity in humans

Ghrelin and preproghrelin sequences were determined in 96 unrelated female subjects with severe obesity (mean body mass index (BMI) 42.3 +/- 3.4 kg/m(2)) and in 96 non-obese female controls (mean BMI 23.0 +/- 1.4 (kg/m2) of the Swedish Obese Subjects cohort. A mutation at amino acid position 51 (Arg51Gln) of the preproghrelin sequence that corresponds to the last amino acid in mature ghrelin product was identified in six (all heterozygotes) obese subjects (6.3%) but not among controls (p < 0.05). The self-reported weight at 20, 30, and 40 years of age tended to be 7.5, 4.7 and 6.4 kg lower, respectively, among obese Gln allele carriers versus obese non-carriers. In addition, a mutation at codon 72 of the preproghrelin gene (Leu72Met) was detected in 15 obese (12 hetero- and 3 homozygotes) and 12 control (all heterozygotes) subjects. This mutation outside the coding region of the mature ghrelin product tended to be associated with lower age of self-reported onset of obesity (15.6 +/- 7.9 vs. 20.5 +/- 10.5 years; p = 0.09). In addition to these two mutations in coding regions, a G274A base change in a non-coding region between exons one and two was found only in two obese individuals. The Arg51Gln amino acid substitution may alter the cleavage site of endoproteases and the length of the mature ghrelin product. The functional significance of the Leu72Met mutation and a G274A base change remains to be determined. In conclusion, the data provide evidence that a low frequency sequence variation in the ghrelin gene could play a role in the etiology of obesity.

Polymorphism in exon 6 of the dopamine D(2) receptor gene (DRD2) is associated with elevated blood pressure and personality disorders in men

A deficient dopamine D(2) receptor (DA2) formation or action may contribute to hypertension via an increase of catecholamine release. In addition, Axis II personality disorders that appears odd or eccentric (cluster A) is associated with a low density of DA2. This study sought to examine if a NcoI restriction fragment length polymorphism (C to T transition) in exon 6 of the dopamine D(2) receptor gene (DRD2) was associated with these characteristics. The genotypes (CC, CT and TT) were compared in anthropometric, endocrine, metabolic and haemodynamic variables as well as estimates of personality disorders in 284 randomly selected 51-year-old men. Homozygotes for the C allele constituted 49% of the men and homozygotes for the T allele 9%, while heterozygotes were 41%. The TT genotype was associated with elevated systolic and diastolic blood pressure, independent of obesity and endocrine abnormalities, including the hypothalamic-pituitary-adrenal axis regulation. Moreover, the TT genotype was significantly more frequent among subjects with grade 1 (mild) hypertension (>140/90 mm Hg) compared to normotensive subjects (<130/85 mm Hg). The polymorphism in exon 6 of the DRD2 was also significantly associated with cluster A personality disorders. These results suggest that a polymorphism in exon 6 of the DRD2examined with the restriction enzyme NcoI is associated with an elevated blood pressure, independent of obesity. Paranoid or schizoid personality disorders is also associated with a polymorphism of the DRD2, which might be associated with a previously demonstrated low density of this receptor.

Association between uncoupling protein 3 gene and obesity-related phenotypes in the Québec Family Study

BACKGROUND

UCP3 is a mitochondrial membrane transporter that is postulated to uncouple oxidative phosphorylation from ATP synthesis producing heat instead of ATP. Human UCP3 is mainly expressed in skeletal muscle, which plays an important role in energy homeostasis and substrate oxidation. Therefore, UCP3 is a good candidate gene for obesity.

MATERIALS AND METHODS

We analyzed, among 734 subjects from the Québec Family Study, a new GA repeat microsatellite located in intervening sequence (IVS) 6 (GAIVS6) in UCP3 gene, and two already described restriction fragment length polymorphisms (RFLP) Y210Y(C-->T) and V102I(G-->A). Covariance analysis across genotypes for different adiposity, resting energy expenditure, and glucose metabolism variables was undertaken with age and sex, plus body fat and body mass for nonadiposity phenotypes, as covariates.

RESULTS

We found strong associations between GAIVS6 and body mass index (p = 0.0001), fat mass (p = 0.0005), percentage body fat (p = 0.0004), the sum of six skinfold thickness (p = 0.0001), and leptin level (p = 0.0001). Homozygote for the GAIVS6 240 bp alleles (15% frequency in QFS) showed higher adiposity than subjects with the GAIVS6 238 bp allele (70% in QFS). The exons, the 5' untranslated region (UTR), and the exon-intron junctions of UCP3 gene from subjects homozygote for either GAIVS6 238 bp or 240 bp alleles were sequenced in search for mutations. Variants 5'UTR-55C-->T and Y210Y(C-->T) were detected, whereas IVS4-36C-->T was uncovered, but no new exonic or splice junction mutation was observed. RFLP Y210Y(C-->T) was not associated to adiposity in QFS; V1021(G-->A) showed no variation.

CONCLUSION

Our results suggest that some alleles of UCP3 are involved in the etiology of human obesity.

Leptin receptor gene polymorphisms are associated with insulin in obese women with impaired glucose tolerance

Leptin receptors are present on beta-cells as well as on muscle and fat cells, thus enabling leptin to modulate both insulin secretion and insulin action. Leptin inhibits especially the glucose-stimulated insulin secretion from pancreatic cells. The leptin receptor (LEPR) gene could thus play a role in the regulation of glucose and insulin after an oral glucose load. Therefore, the relationship between LEPR polymorphisms and glucose and insulin response to an oral glucose tolerance test (OGTT) was investigated. Three LEPR polymorphisms (Lys(109)Arg, Gln(223)Arg, and Lys(656)Asn) were typed on genomic DNA of 358 overweight and obese women, aged 18-60 yr. Based on an OGTT, 269 subjects were defined with normal glucose tolerance, and 89 with impaired glucose tolerance (IGT). Associations between genotypes and glucose metabolism were analyzed with a general linear models procedure in pre- and postmenopausal women separately, after adjusting the data for age and fat mass. In postmenopausal women with IGT (n = 24), associations were found with Lys(109)Arg and Lys(656)Asn for fasting insulin (P = 0.05) and with Lys(109)Arg and Gln(223)Arg for the insulin response to an OGTT (P < 0.02). In the same group, trends were found with Lys(656)Asn for fasting glucose as well as in response to the OGTT. In premenopausal women with IGT (n = 65), associations were found with Lys(109)Arg and Lys(656)Asn for overall glucose response to the glucose load. In contrast, no associations with insulin or glucose were found in women with normal glucose tolerance. In conclusion, these data indicate that LEPR polymorphisms are associated with insulin and glucose metabolism in women with impaired glucose homeostasis.

G-308A polymorphism of the tumor necrosis factor alpha gene promoter and salivary cortisol secretion

The objective of the current study was to examine the potential impact of the G-->A substitution at position -308 of the tumor necrosis factor alpha (TNF-alpha) gene promoter on obesity and estimates of insulin, glucose, and lipid metabolism as well as circulating hormones including salivary cortisol in 284 unrelated Swedish men born in 1944. The subjects were genotyped by using PCR amplification of the 5' untranslated region of the TNF-alpha gene followed by digestion with the restriction enzyme NcoI. The frequencies were 0.77 for allele G and 0.23 for allele A. Tests for differences in salivary cortisol levels between the TNF-alpha genotypes revealed that there were significantly higher cortisol levels in the morning, before as well as 30 and 60 min after stimulation by a standardized lunch in homozygotes for the rare allele in comparison with the other genotypes. In addition, homozygotes for the rare allele had a tendency toward higher mean values of body mass index, waist to hip ratio, and abdominal sagittal diameter compared with the other genotype groups. The results also indicated a weak trend toward elevated insulin and glucose levels among men with the A/A genotype. In conclusion, a G-->A polymorphism in the 5' untranslated region of the TNF-alpha gene is associated with elevated morning cortisol levels as well as elevated postprandial cortisol secretion. This increase in cortisol secretion might be the endocrine mechanism underlying the previously observed associations between the NcoI TNF-alpha polymorphism and obesity as well as insulin resistance. However, to what extent this polymorphism is associated with these conditions is uncertain from the present data.

A genome-wide scan for abdominal fat assessed by computed tomography in the Québec Family Study

To identify chromosomal regions harboring genes influencing the propensity to store fat in the abdominal area, a genome-wide scan for abdominal fat was performed in the Quebec Family Study. Cross-sectional areas of the amount of abdominal total fat (ATF) and abdominal visceral fat (AVF) were assessed from a computed tomography scan taken at L4-L5 in 521 adult subjects. Abdominal subcutaneous fat (ASF) was obtained by computing the difference between ATF and AVF. The abdominal fat phenotypes were adjusted for age and sex effects as well as for total amount of body fat (kilogram of fat mass) measured by underwater weighing, and the adjusted phenotypes were used in linkage analyses. A total of 293 microsatellite markers spanning the 22 autosomal chromosomes were typed. The average intermarker distance was 11.9 cM. A maximum of 271 sib-pairs were available for single-point (SIBPAL) and 156 families for multipoint variance components (SEGPATH) linkage analyses. The strongest evidence of linkage was found on chromosome 12q24.3 between marker D12S2078 and ASF (logarithm of odds [LOD] = 2.88). Another marker (D12S1045) located within 2 cM of D12S2078 also provided evidence of sib-pair linkage with ASF (P = 0.019), ATF (P = 0.015), and AVF (P = 0.0007). Other regions with highly suggestive evidence (P < 0.0023 or LOD > or =1.75) of multipoint linkage and evidence (P < 0.05) of single-point linkage, all for ASF, included chromosomes 1p11.2, 4q32.1, 9q22.1, 12q22-q23, and 17q21.1. Three of these loci (1p11.2, 9q22.1, and 17q21.1) are close to genes involved in the regulation of sex steroid levels, whereas two others (4q32.1 and 17q21.1) are in the proximity of genes involved in the regulation of food intake. This first genome-wide scan for abdominal fat assessed by computed tomography indicates that there may be several loci determining the propensity to store fat in the abdominal depot and that some of these loci may influence the development of diabetes in obese subjects.

Uridine uptake inhibition as a cytotoxicity test for a human hepatoma cell line (HepG2 cells): comparison with the neutral red assay

This study describes a sensitive microassay for measuring cytotoxicity based on the degree of inhibition of RNA synthesis in HepG2 cells. RNA synthesis is measured by the kinetic uptake of radiolabeled uridine. A large number of compounds were tested in a wide range of concentrations. The concentration required to induce 50% inhibition of HepG2 uridine uptake rates (IC(50)) was determined for each compound and used to rank its potency. These IC(50)s were compared with IC(50)s measured with the neutral red assay. 2-acetylaminofluorene, benzo[a]pyrene and methylnitrosourea were not cytotoxic in the neutral red assay. Uridine uptake was always inhibited at lower concentrations than those required in the neutral red assay, suggesting that the uridine uptake assay is a more sensitive indicator of toxic action than the neutral red inclusion. Uridine uptake assay provides a rapid and quantitative method for assessing toxicity in a human cell line. Application of this method to bottled spring waters are described. Due to its high sensitivity and reproducibility, this method provides a suitable tool for screening a great number of samples and will be a helpful test for evaluating food safety and controlling the recycling process of wrapping materials.

A polymorphism in the alpha2a-adrenoceptor gene and endurance athlete status

PURPOSE

In a case control study, we examined the allelic frequencies and genotype distributions of two restricted fragment length polymorphisms (RFLP) in the alpha-2A-adrenoceptor gene (ADRA2A) and beta-2-adrenoceptor gene (ADRB2) among elite endurance athletes (EEA) and sedentary controls (SC).

METHODS

The EEA group included 148 Caucasian male subjects recruited on the basis that they had a VO2max > 74 mL O2 x kg(-1) x min(-1). The SC group comprised 149 unrelated sedentary male subjects, all Caucasians, from the Quebec Family Study. After digestion with the restriction enzymes Dra I (ADRA2A) and Ban I (ADRB2), Southern blotting and hybridization techniques were used to detect the mutations in the two ADR genes, which are encoded on chromosomes 10 (q24-26) and 5 (q31-32), respectively.

RESULTS

For the Dra I ADRA2A RFLP, we observed a significant difference in genotype distributions between the two groups (P = 0.037). A higher frequency of the 6.7-kb allele was observed in the EEA group compared with the SC group (P = 0.013). No statistically significant difference was found between groups for the Ban I ADRB2 polymorphic site. Genotype frequencies for both genes in both groups were in Hardy-Weinberg equilibrium.

CONCLUSIONS

In summary, we found evidence that ADRA2A gene variability detected with Dra I is weakly associated with elite endurance athlete status, and we conclude that genetic variation in the ADRA2A gene or a locus in close proximity may play a role in being able to sustain the endurance training regimen necessary to attain a high level of maximal aerobic power.

A polymorphism of the 5'-flanking region of the glucocorticoid receptor gene locus is associated with basal cortisol secretion in men

There is growing evidence that cortisol secretion and/or metabolism is associated with cardiovascular risk factors. Previous studies have shown that cardiovascular risk factors are associated with stimulated cortisol secretion and not with basal cortisol secretion. With the restriction enzyme Tth111I, a variant of the 5'-flanking region of the glucocorticoid receptor gene locus (GRL) was identified. The genotypes were compared for measurements of cortisol secretion and cardiovascular risk factors in a cohort (N = 284) of randomly selected middle-aged men. The frequency of the 3.4/3.4-, 3.4/3.8-, and 3.8/3.8-kilobase (kb) genotypes was 49.6%, 41.4%, and 9.0% respectively. The 3.8-kb homozygotes showed higher total and evening cortisol levels with a trend for elevated levels over the day. Neither stimulated or suppressed cortisol secretion nor anthropometric, endocrine, metabolic, and hemodynamic cardiovascular risk factors were significantly different among the genotypes. Since the polymorphism studied herein is localized at the 5'-flanking region of the GRL, the results suggest that elevated basal cortisol secretion is associated with a polymorphism of the promoter region.

Polymorphisms of the beta2-adrenergic receptor gene (ADRB2) in relation to cardiovascular risk factors in men

OBJECTIVE

To investigate the effect of polymorphisms in codon 16 (Arg16Gly) and codon 27 (Gln27Glu) of the beta2-adrenergic receptor gene (ADRB2) on anthropometric, endocrine, metabolic and haemodynamic variables.

DESIGN

A cross-sectional study.

SUBJECTS

A subgroup of 284 Swedish men from a population sample of 1040 at the age of 51 years.

MAIN OUTCOME MEASURES

Genotype examination of ADRB2 polymorphisms in codon 16 and codon 27 with polymerase chain reaction and restriction fragment length polymorphism. Anthropometric measurements included body mass index, waist-to-hip ratio and abdominal sagittal diameter. Endocrine measurements included blood levels of testosterone, insulin-like growth factor I, and leptin plus salivary cortisol. Overnight fasting values of serum insulin, blood glucose, triglycerides, total, low and high density lipoprotein cholesterol, as well as blood pressure and resting heart rate, were also determined.

RESULTS

Polymorphisms were frequent in both codon 16 and codon 27. The Arg16Gly genotype showed significant relationships to elevated central distribution of body fat and to systolic blood pressure, whilst the Glu27Glu genotype was associated with elevated leptin and triglyceride levels but not to other measurements, including obesity variables.

CONCLUSIONS

We conclude that only a few cardiovascular risk factors are associated with DNA sequence variation in the ADRB2 in Swedish men.

Hypertension in obesity and the leptin receptor gene locus

Recent animal studies indicate that leptin is involved in the regulation of blood pressure through the leptin receptor. Therefore, 51-yr-old men (N = 284) were selected; and anthropometric, endocrine, metabolic, and hemodynamic variables were examined in relation to polymorphisms of the leptin receptor gene (LEPR), by restriction fragment length polymorphism technique. Three polymorphisms were examined: Lys109Arg in exon 4, Gln223Arg in exon 6, and Lys656Asn in exon 14. In comparison with Lys109 homozygotes, Arg109 homozygotes (9%) showed lower body mass index (BMI) and abdominal sagittal diameter, as well as lower systolic (10.0 mm Hg) and diastolic (7.8 mm Hg) blood pressure. Additionally, Arg223 homozygotes (26.8%) showed lower blood pressure (7.6/5.7 mm Hg) than Gln223 homozygotes. These lower blood pressure levels were independent of other variables. No differences were found with the Lys656Asn polymorphism. Measurements of body fat mass correlated with leptin concentration in Lys109 homozygotes and in Lys109 heterozygotes but not in Arg109 homozygotes. Blood pressure correlated with leptin only in men carrying the wild-type allele Lys109. With both elevated BMI and leptin, Lys109 homozygotes had higher blood pressure than the Arg109 homozygous men (12.4/6.9 mm Hg). Men with blood pressure > or = 140/90 mm Hg had, in comparison with normotensive men, increased BMI and leptin levels, and Lys109 homozygotes were significantly more prevalent. These results suggest that leptin is associated with blood pressure regulation in men through the leptin receptor. When BMI and leptin are elevated, increased blood pressure is found only with the most prevalent LEPR genotype at codons 109 and 223, whereas variants of this receptor seem to protect from hypertension. This might explain why not all obese men are hypertensive.

A glucocorticoid receptor gene marker is associated with abdominal obesity, leptin, and dysregulation of the hypothalamic-pituitary-adrenal axis

OBJECTIVE

Abdominal obesity has a key role in the pathogenesis of prevalent and serious diseases and has been shown to be associated with an altered hypothalamic-pituitary-adrenal (HPA) axis function, which is regulated by endocrine feedback mediated via hippocampal glucocorticoid receptors (GR).

RESEARCH METHODS AND PROCEDURES

We examined the HPA axis function by repeated salivary samples for the assessment of cortisol, as well as other endocrine, anthropometric, metabolic, and circulatory variables in middle-aged Swedish men (n = 284). With the restriction enzyme BclI, variants of the GR gene (GRL) locus were identified and two alleles with fragment lengths of 4.5 and 2.3 kilobases (kb) were detected.

RESULTS

The observed frequencies were 40.1% for the 2.3- and 2.3-kb, 46.2% for the 4.5- and 2.3-kb, and 13.7% for the 4.5- and 4.5-kb genotypes. The larger allele (4.5 and 4.5 kb) was associated with elevated body mass index (BMI; p < 0.001), waist-to-hip circumference ratio (p = 0.015), abdominal sagittal diameter (p = 0.002), leptin (p < 0.001), and systolic blood pressure (borderline, p = 0.058). The 4.5- and 4.5-kb allele was associated with leptin after adjustment for BMI. Moreover, salivary cortisol values, particularly after stimulation by a standardized lunch (p = 0.040 to 0.086), were elevated in the men with the larger allele.

DISCUSSION

These results indicate that there is an association between a deficient GR function, defined as a poor feedback regulation of the HPA axis activity, and a polymorphic restriction site at the GR gene locus. An abnormal control of HPA axis function due to genetic alterations may contribute to the pathogenesis of abdominal obesity.

A common polymorphism in the human insulin-like growth factor binding protein 3 gene

A common polymorphism generated by an A to C transition at nucleotide 7580 in the third intron of the insulin-like growth factor binding protein 3 gene was found. This polymorphism can be identified by Nde 1 restriction of genomic DNA amplified with a specifically designed restriction enzyme site-generating oligonucleotide primer. The frequency of the A and C alleles was estimated at 0.6 and 0.4 in the Caucasians, 0.63 and 0.37 in Blacks, respectively.