Onset and Evolution of Southern Annular Mode-Like Changes at Centennial Timescale.

The Southern Westerly Winds (SWW) are the surface expression of geostrophic winds that encircle the southern mid-latitudes. In conjunction with the Southern Ocean, they establish a coupled system that not only controls climate in the southern third of the world, but is also closely connected to the position of the Intertropical Convergence Zone and CO2 degassing from the deep ocean. Paradoxically, little is known about their behavior since the last ice age and relationships with mid-latitude glacier history and tropical climate variability. Here we present a lake sediment record from Chilean Patagonia (51°S) that reveals fluctuations of the low-level SWW at mid-latitudes, including strong westerlies during the Antarctic Cold Reversal, anomalously low intensity during the early Holocene, which was unfavorable for glacier growth, and strong SWW since ~7.5 ka. We detect nine positive Southern Annular Mode-like events at centennial timescale since ~5.8 ka that alternate with cold/wet intervals favorable for glacier expansions (Neoglaciations) in southern Patagonia. The correspondence of key features of mid-latitude atmospheric circulation with shifts in tropical climate since ~10 ka suggests that coherent climatic shifts in these regions have driven climate change in vast sectors of the Southern Hemisphere at centennial and millennial timescales.

Insulin resistance in hidradenitis suppurativa: a case-control study.

BACKGROUND: The association between chronic inflammatory diseases, such as rheumatoid arthritis and psoriasis, and insulin resistance (IR) has been well established. Hidradenitis suppurativa (HS) is a chronic inflammatory cutaneous disease that affects the apocrine gland-bearing areas of the body. OBJECTIVE: We aimed to determine the prevalence of IR in patients with HS. METHODS: This cross-sectional, case-control study enrolled 137 subjects, 76 patients with HS and 61 age- and gender-matched controls. Demographic data, clinical examination of HS patients, anthropometric measures, cardiovascular risk factors and laboratory studies were recorded. The homeostasis model assessment of IR (HOMA-IR) was calculated in all participants by measuring fasting plasma glucose and insulin levels. RESULTS: The median (IQR) HOMA-IR value in HS patients was significantly higher [2.0 (1.0-3.6)] than in controls [1.5 (0.9-2.3)] (P = 0.01). The prevalence of IR was significantly higher in cases (43.4%) compared with controls (16.4%) (P = 0.001). In the linear regression multivariable analysis after adjusting for age, sex and body mass index (BMI), HS remained as a significant factor for a higher HOMA-IR [2.51 (0.18) vs 1.92(0.21); P = 0.04]. The HOMA-IR value and the prevalence of IR did not differ significantly among HS patients grouped by severity of the disease. CONCLUSION: Our results show an increased frequency of IR in HS. Thus, we suggest HS patients to be evaluated for IR and managed accordingly.

Thyroid autoimmunity in patients with hidradenitis suppurativa: a case-control study.

The aetiopathogenesis of hidradenitis suppurativa (HS) is not fully understood; however, increasing evidence suggests that it may be an immune-mediated disorder. Autoimmune thyroid disease (AITD) has classically been considered as the 'paradigm' of autoimmunity, and it has been linked to a variety of skin disorders. To our knowledge, the prevalence of AITD has not been investigated in patients with HS. The aim of the present study was to assess and compare, for the first time, the prevalence of thyroid autoimmunity in 70 patients with HS and in 70 age- and sex-matched controls. In all participants, thyroid autoantibodies and thyroid function tests were analysed. No statistically significant difference was detected between patients with HS and controls, either for the prevalence of thyroid antibodies or for thyroid function parameters. This lack of an association between HS and thyroid autoimmunity suggests that conventional autoimmune mechanisms may not be implicated in the pathogenesis of HS.

Effects of Cannabinoid Exposure during Adolescence on the Conditioned Rewarding Effects of WIN 55212-2 and Cocaine in Mice: Influence of the Novelty-Seeking Trait.

Adolescent exposure to cannabinoids enhances the behavioural effects of cocaine, and high novelty-seeking trait predicts greater sensitivity to the conditioned place preference (CPP) induced by this drug. Our aim was to evaluate the influence of novelty-seeking on the effects of adolescent cannabinoid exposure. Adolescent male mice were classified as high or low novelty seekers (HNS and LNS) in the hole-board test. First, we evaluated the CPP induced by the cannabinoid agonist WIN 55212-2 (0.05 and 0.075 mg/kg, i.p.) in HNS and LNS mice. Then, HNS and LNS mice were pretreated i.p. with vehicle, WIN 55212-2 (0.1 mg/kg), or cannabinoid antagonist rimonabant (1 mg/kg) and were subsequently conditioned with WIN 55212-2 (0.05 mg/kg, i.p.) or cocaine (1 or 6 mg/kg, i.p.). Only HNS mice conditioned with the 0.075 mg/kg dose acquired CPP with WIN 55212-2. Adolescent exposure to this cannabinoid agonist increased the rewarding effects of 1 mg/kg of cocaine in both HNS and LNS mice, and in HNS mice it also increased the reinstating effect of a low dose of cocaine. Our results endorse a role for individual differences such as a higher propensity for sensation-seeking in the development of addiction.

Southern Annular Mode-like changes in southwestern Patagonia at centennial timescales over the last three millennia.

Late twentieth-century instrumental records reveal a persistent southward shift of the Southern Westerly Winds during austral summer and autumn associated with a positive trend of the Southern Annular Mode (SAM) and contemporaneous with glacial recession, steady increases in atmospheric temperatures and CO2 concentrations at a global scale. However, despite the clear importance of the SAM in the modern/future climate, very little is known regarding its behaviour during pre-Industrial times. Here we present a stratigraphic record from Lago Cipreses (51°S), southwestern Patagonia, that reveals recurrent ~200-year long dry/warm phases over the last three millennia, which we interpret as positive SAM-like states. These correspond in timing with the Industrial revolution, the Mediaeval Climate Anomaly, the Roman and Late Bronze Age Warm Periods and alternate with cold/wet multi-centennial phases in European palaeoclimate records. We conclude that SAM-like changes at centennial timescales in southwestern Patagonia represent in-phase interhemispheric coupling of palaeoclimate over the last 3,000 years through atmospheric teleconnections.