A large outbreak of the Kappa mutation of COVID-19 in Cork, Ireland, April-May 2021

BACKGROUND

In May 2021, the B.1.617 variant of SARS-CoV-2 emerged in Ireland, and both Delta and Kappa sub-lineages were initially deemed variants of concern (VOCs) on a precautionary basis. We describe a large outbreak of SARS-CoV-2 B.1.617.1 (Kappa mutation) linked to a private gathering among third level students in Cork, Ireland.

METHODS

Surveillance data were available from the Health Service Executive COVID Care Tracker. The epidemiological sequence of infection for each new case in this outbreak was tracked and whole genome sequencing was requested on all linked cases. Enhanced public health control measures were implemented by the Department of Public Health HSE-South to contain onward spread of VOCs, including retrospective contact tracing, lengthy isolation and quarantine periods for cases and close contacts. Extensive surveillance efforts were used to describe and control onward transmission.

RESULTS

There were 146 confirmed SARS-CoV-2 cases linked to the outbreak. All sequenced cases (53/146; 36%) confirmed Kappa mutation. The median age was 21 years (range 17-65). The majority (88%) had symptoms of SARS-CoV-2 infection. There were 407 close contacts; the median was 3 per case (range 0-14). There were no known hospitalisations, ICU admissions or deaths. Vaccination data was unavailable, but the outbreak pre-dated routine availability of COVID-19 vaccines among younger adults in Ireland.

CONCLUSION

Enhanced public health control measures for new and emerging variants of SARS-CoV-2 may be burdensome for cases and close contacts. The overall public health benefit of enhanced controls may only become apparent when evidence on disease transmissibility and severity becomes more complete.

An analysis of hospital-treated attempted hanging and drowning in Ireland, 2007-2019

Background

Highly lethal of methods of self-harm, such as attempted hanging and drowning, are a major public health concern due to their high associated risk of completed suicide. This study aims to describe hospital presentations for attempted hanging and drowning in Ireland and explore the factors associated with self-harm and repeat self-harm by these methods.

Methods

Data on all self-harm presentations to Irish hospitals (2007-2019) were obtained from the National Self-Harm Registry Ireland, a national surveillance system of hospital-treated self-harm. Multivariable logistic regression was used to explore factors associated with any presentation for attempted hanging and drowning and factors associated with repetition of attempted hanging and drowning.

Results

There were 9,719 and 4,637 attempted hanging and drowning hospital presentations, respectively, in Ireland in 2007-2019. The odds of presentations being due to hanging, rather than due to any other self-harm method, were highest for males (aOR 2.88, 95% CI: 2.76-3.02), children aged <15 (aOR 1.32, 1.17-1.48) and in summer (aOR 1.09, 1.02-1.14). The odds of presentations being due to drowning, rather than due to any other self-harm method, were highest for those aged ≥55 (aOR 1.60, 1.43-1.78), homeless individuals (aOR 2.59, 2.32-2.89) and in autumn (aOR 1.15, 1.06-1.25). Repetition of attempted hanging was positively associated with homelessness (aOR 2.47, 2.02-3.04) and acute alcohol ingestion (aOR 1.12, 1.02-1.23). Similar associations were observed for repetition of attempted drowning.

Conclusions

This study identifies key population groups for whom the risk of self-harm, or repeat self-harm, by hanging and drowning is greatest. Universal, targeted and indicated interventions are needed to address the determinants of highly lethal methods of self-harm. Biopsychosocial assessments of those presenting after attempted hanging and drowning are essential, in view of their high risk of repeat self-harm and suicide.

Key messages

An in vitro biofilm model system to facilitate study of microbial communities of the human oral cavity

The human oral cavity is host to a diverse microbiota. Much of what is known about the behaviour of oral microbes derives from studies of individual or several cultivated species, situations which do not totally reflect the function of organisms within more complex microbiota or multispecies biofilms. The number of validated models that allow examination of the role that biofilms play during oral cavity colonization is also limited. The CDC biofilm reactor is a standard method that has been deployed to study interactions between members of human microbiotas allowing studies to be completed during an extended period under conditions where nutrient availability, and washout of waste products are controlled. The objective of this work was to develop a robust in vitro biofilm-model system from a pooled saliva inoculum to study the development, reproducibility and stability of the oral microbiota. By employing deep sequencing of the variable regions of the 16S rRNA gene, we found that the CDC biofilm reactor could be used to efficiently cultivate microbiota containing all six major phyla previously identified as the core saliva microbiota. After an acclimatisation period, communities in each reactor stabilised. Replicate reactors were predominately populated by a shared core microbiota; variation between replicate reactors was primarily driven by shifts in abundance of shared operational taxonomic units. We conclude that the CDC biofilm reactor can be used to cultivate communities that replicate key features of the human oral cavity and is a useful tool to facilitate studies of the dynamics of these communities.

Potential alcohol use disorder (AUD) among men who have sex with men (MSM) in Ireland

Background

Alcohol consumption is a major public health concern in Ireland. Alcohol use disorder (AUD) appears to disproportionately affect men who have sex with men (MSM). However, little is known about the prevalence of AUD in this group in Ireland specifically, and the characteristics of MSM who may struggle with this.

Methods

The European MSM Internet Survey 2017 was an online, self-completed, anonymous questionnaire among MSM residing in Ireland. Standardised questions were used to explore a variety of topics. The validated CAGE-4 questionnaire was used to screen for potential AUD, defined as a CAGE-4 score of ≥ 2 out of 4. Multivariable-adjusted logistic regression analysis was used to identify factors associated with potential AUD.

Results

In total, 1,793 MSM met inclusion criteria, and 31% screened positive for AUD. We observed higher odds of possible AUD among MSM who were bisexual (vs. gay/homosexual) (aOR 1.48 95%CI 1.01-2.18), native to Ireland (vs. non-native) (aOR 1.49 95%CI 1.12-1.96), unemployed (vs. employed) (aOR 1.80 95%CI 1.02-3.16), had used illicit drugs in the previous year (vs. none) (cannabis only, aOR 1.74 95%CI 1.14-2.63) (other illicit drugs, aOR 2.28 95%CI 1.67-3.09), reported anxiety/depression (vs. none) (aOR 1.73 95%CI 1.12-2.66), and MSM who experienced homophobic abuse (vs. never) (aOR 1.55 95%CI 1.09-2.22). Student MSM were less likely to screen positive for AUD (vs. employed) (aOR 0.65 95%CI 0.46-0.93).

Conclusions

The prevalence of AUD appears to be higher in the MSM population compared to the general male population in Ireland. Targeted interventions may be warranted to reduce the burden of AUD among MSM.

Key messages

The prevalence of AUD appears to be higher in the MSM population compared to the general male population in Ireland. Targeted interventions may be warranted to reduce the burden of AUD among MSM.

Covid-19 presentation among symptomatic healthcare workers in Ireland

BACKGROUND

It is recognized that healthcare workers (HCWs) are at high risk of contracting Covid-19. It is incumbent on occupational health staff to recognize potential symptoms of Covid-19 among HCWs.

AIMS

The aims of the study were to describe the presenting symptoms of HCWs who developed Covid-19 in Ireland, and to estimate the odds of specific symptoms being associated with a positive Covid-19 polymerase chain reaction (PCR) result.

METHODS

A retrospective chart review of all symptomatic HCWs who self-presented for Covid-19 testing in Cork from March to May 2020 was conducted. A sex-matched case-control study was carried out to compare presenting features among those who tested positive compared to those who tested negative. Univariate and multivariable-adjusted conditional logistic regression models were run using Stata 15.0 to identify the symptoms associated with positive Covid-19 swab results.

RESULTS

Three hundred and six HCWs were included in the study; 102 cases and 204 controls. Common presenting features among cases were fever/chills (55%), cough (44%) and headache (35%). The symptoms which were significantly associated with a positive Covid-19 swab result were loss of taste/smell (adjusted odds ratio [aOR] 12.15, 95% confidence interval [CI] 1.36-108.79), myalgia (aOR 2.36, 95% 1.27-4.38), fatigue (aOR 2.31, 95% CI 1.12-4.74), headache (aOR 2.11, 95% CI 1.19-3.74) and fever/chills (aOR 1.88, 95% CI 1.12-3.15).

CONCLUSIONS

Fever, fatigue, myalgia, loss of taste/smell and headache were associated with increased odds of a Covid-19 diagnosis among symptomatic self-referred HCWs compared with those had negative swab results. Testing criteria for HCWs should reflect the broad range of possible symptoms of Covid-19.

Preeclampsia and the risk of chronic kidney disease: a national registry-based cohort study

Background

Preeclampsia is associated with increased risk of future cardiovascular disease, but evidence for associations with chronic kidney disease (CKD) has been inconsistent to date. We aimed to measure associations between preeclampsia and long-term CKD in a population-based sample of parous women, and to identify whether the risk differs by CKD subtype.

Methods

Using data from the Swedish Medical Birth Register, singleton live births from 1973-2012 were identified and linked to data from the Swedish Renal Register and National Patient Register (up to 2013). Preeclampsia was the main exposure of interest and was treated as a time-dependent variable. The primary outcome was maternal CKD, and this was classified into 5 subtypes: hypertensive, diabetic, glomerular/proteinuric, tubulo-interstitial, other/non-specific CKD. Cox proportional hazard regression models were used for analysis. Women with pre-pregnancy comorbidities were excluded.

Results

The dataset included 1,924,591 unique women who had 3,726,819 singleton pregnancies. The median follow-up was 20.7 (interquartile range 9.9-30.0) years. Overall, 90,964 women (4.7%) experienced preeclampsia and 18,146 (0.9%) developed CKD. Women who had preeclampsia had higher risk of developing any CKD during follow-up (aHR 1.88, 95% CI 1.79-1.98). The risk differed by CKD subtype, and was higher for hypertensive CKD (aHR 3.76, aHR 3.09-4.57), diabetic CKD (aHR 3.45, 95% CI 2.83-4.21) and glomerular/proteinuric CKD (aHR 2.08, 95% CI 1.90-2.29). Women who had preterm preeclampsia, recurrent preeclampsia, or preeclampsia complicated by pre-pregnancy obesity were also at greater risk of any CKD.

Conclusions

Women with a history of preeclampsia are at increased risk of long-term CKD. The risk is most marked for hypertensive CKD, diabetic CKD, and glomerular/proteinuric CKD. The absolute risk of CKD related to preeclampsia is substantial, and these women may warrant systematic renal monitoring in the years following delivery.

Key messages

Preeclampsia is an independent predictor of long-term risk of chronic kidney disease in otherwise healthy parous women. Women with a history of preeclampsia may warrant systematic renal monitoring through additional blood pressure, blood glucose, and proteinuria checks.

Adverse pregnancy outcomes and long-term risk of maternal renal disease: a systematic review

Background

Little is known about the long-term risk of renal disease following adverse pregnancy outcomes, such as hypertensive disorders of pregnancy (HDP), gestational diabetes (GDM) or preterm delivery. We aimed to investigate associations between adverse pregnancy outcomes and maternal chronic kidney disease (CKD) and end-stage kidney disease (ESKD), by synthesising results of relevant studies.

Methods

A systematic search of PubMed, EMBASE and Web of Science was done up to July 2018. Case-control and cohort studies were eligible for inclusion if they provided original effect estimates for associations between adverse pregnancy outcomes (HDP, GDM, preterm) and maternal renal disease (primary outcomes: CKD, ESKD; secondary outcomes: renal hospitalisation, renal mortality). Two independent reviewers extracted data and assessed risk of bias. Random effects meta-analyses were conducted to determine pooled adjusted odds ratio (AOR) and 95% confidence interval (95%CI) for each association.

Results

Of 5,120 studies retrieved, 21 studies met inclusion criteria (4,483,847 participants). HDP was associated with increased odds of ESKD (AOR 6.58, 95%CI 4.06-10.65), CKD (AOR 2.08, 95%CI 1.06-4.10), renal hospitalisation (AOR 2.29, 95%CI 1.42-3.71). The magnitude of association was dependent on HDP subtype: AOR for preeclampsia and ESKD was 4.87 (95%CI 3.01-7.87); gestational hypertension and ESKD was 3.65 (95%CI 2.34-5.67); other HDP (including chronic hypertension) and ESKD was 14.67 (95%CI 3.21-66.97). Preterm delivery was associated with increased odds of ESKD (AOR 2.16, 95%CI 1.64-2.85). GDM was associated with increased odds of CKD among black women (AOR 1.78, 95%CI 1.18-2.70), but not Caucasian women (AOR 0.81, 95%CI 0.58-1.13)

Conclusions

Women who experience adverse pregnancy outcomes have increased odds of renal disease, especially after HDP. Risk stratification and preventive interventions may be needed to reduce the risk of clinically significant renal disease in mothers.

Key messages

This is the first study to summarise the long-term risk of renal disease among women who experience a range of adverse pregnancy outcomes. Women who experience hypertensive disorders in pregnancy, preterm delivery, or gestational diabetes are at increased odds of renal disease.

Preterm delivery is associated with long-term risk of maternal renal disease

Background

Preterm delivery is an independent risk factor for maternal cardiovascular disease. Little is known about the association between preterm delivery and maternal renal function, and whether any association is independent of preeclampsia or intra-uterine growth restriction. This study aimed to examine the association between gestational age and long-term maternal chronic kidney disease (CKD) and end-stage kidney disease (ESKD).

Methods

Using data from the Swedish Medical Birth Register, singleton live births from 1973-2012 were identified and linked to data from the Swedish Renal Register and National Patient Register (up to 2013). Women with pre-pregnancy CKD/ESKD, cardiovascular disease, diabetes, hypertension, systemic lupus erythematosus were excluded. Gestational age at delivery was the main exposure, treated as a time-dependent variable. Primary outcomes were maternal CKD or ESKD. Cox regression was used, adjusting for maternal age, year of delivery, country of origin, education, parity, interpregnancy interval, smoking, BMI, gestational diabetes. Models were stratified by exposure to preeclampsia or small for gestational age (SGA).

Results

There were 3,847,694 pregnancies among 1,990,273 unique women. Nine percent of women (n = 172,915) had at least one preterm delivery (<37 weeks). Exposure to preterm delivery was associated with higher risk of CKD (aHR 1.48, 95%CI 1.41-1.54) and ESKD (aHR 2.52, 95%CI 2.17-2.92). Earlier gestational age at delivery was associated with increasing risk of CKD and ESKD. Women with spontaneous preterm delivery were at higher risk of CKD (vs. normal term, aHR 1.33, 95% CI 1.26-1.40) and ESKD (aHR 2.02, 95%CI 1.69-2.40) independently of preeclampsia/SGA. Associations persisted after excluding women who developed postpartum cardiovascular disease, hypertension or diabetes.

Conclusions

Women who gave birth at earlier gestation were at higher risk of later CKD and ESKD. This association persisted independently of preeclampsia and SGA.

Key messages

Preterm delivery is an independent predictor of long-term maternal renal disease. Obstetric history should be considered as part of overall risk stratification for chronic kidney disease in women.

Epidermal autophagy and beclin 1 regulator 1 and loricrin: a paradigm shift in the prognostication and stratification of the American Joint Committee on Cancer stage I melanomas

BACKGROUND

The updated American Joint Committee on Cancer (AJCC) staging criteria for melanoma remain unable to identify high-risk stage I tumour subsets.

OBJECTIVES

To determine the utility of epidermal autophagy and beclin 1 regulator 1 (AMBRA1)/loricrin (AMLo) expression as a prognostic biomarker for AJCC stage I cutaneous melanoma.

METHODS

Peritumoral AMBRA1 expression was evaluated in a retrospective discovery cohort of 76 AJCC stage I melanomas. AMLo expression was correlated with clinical outcomes up to 12 years in two independent powered, retrospective validation and qualification cohorts comprising 379 AJCC stage I melanomas.

RESULTS

Decreased AMBRA1 expression in the epidermis overlying primary melanomas in a discovery cohort of 76 AJCC stage I tumours was associated with a 7-year disease-free survival (DFS) rate of 81·5% vs. 100% survival with maintained AMBRA1 (P < 0·081). Following an immunohistochemistry protocol for semi-quantitative analysis of AMLo, analysis was undertaken in validation (n = 218) and qualification cohorts (n = 161) of AJCC stage I melanomas. Combined cohort analysis revealed a DFS rate of 98·3% in the AMLo low-risk group (n = 239) vs. 85·4% in the AMLo high-risk cohort (n = 140; P < 0·001). Subcohort multivariate analysis revealed that an AMLo hazard ratio (HR) of 4·04 [95% confidence interval (CI) 1·69-9·66; P = 0·002] is a stronger predictor of DFS than Breslow depth (HR 2·97, 95% CI 0·93-9·56; P = 0·068) in stage IB patients.

CONCLUSIONS

Loss of AMLo expression in the epidermis overlying primary AJCC stage I melanomas identifies high-risk tumour subsets independently of Breslow depth. What's already known about this topic? There is an unmet clinical need for biomarkers of early-stage melanoma. Autophagy and beclin 1 regulator 1 (AMBRA1) is a proautophagy regulatory protein with known roles in cell proliferation and differentiation, and is a known tumour suppressor. Loricrin is a marker of epidermal terminal differentiation. What does this study add? AMBRA1 has a functional role in keratinocyte/epidermal proliferation and differentiation. The combined decrease/loss of peritumoral AMBRA1 and loricrin is associated with a significantly increased risk of metastatic spread in American Joint Committee on Cancer (AJCC) stage I tumours vs. melanomas, in which peritumoral AMBRA1 and loricrin are maintained, independently of Breslow depth. What is the translational message? The integration of peritumoral epidermal AMBRA1/loricrin biomarker expression into melanoma care guidelines will facilitate more accurate, personalized risk stratification for patients with AJCC stage I melanomas, thereby facilitating stratification for appropriate follow-up and informing postdiagnostic investigations, including sentinel lymph node biopsy, ultimately resulting in improved disease outcomes and rationalization of healthcare costs.

Drug use among men who have sex with men in Ireland: Prevalence and associated factors from a national online survey

BACKGROUND

Little is known about the prevalence and determinants of drug use among men who have sex with men (MSM) in Ireland. The aims of this study were to measure the prevalence of recreational drug use among MSM in a national sample, and to identify sub-groups of MSM who may benefit from targeted preventive interventions.

METHODS

The MSM Internet Survey Ireland (MISI) 2015 was a community-recruited, nationally-promoted, self-completed online survey for MSM. MISI 2015 included standardised questions on recreational drugs, poppers, and drugs associated with chemsex (i.e. crystal methamphetamine, GBL/GHB, mephedrone, ketamine). Multivariable-adjusted logistic regression was used to identify factors associated with use of these substances.

RESULTS

In the previous year, 36% of MSM used recreational drugs, 33% used poppers, and 7% used drugs associated with chemsex. Five percent were diagnosed HIV-positive. Recreational drug users were significantly younger than non-users (median = 27 vs. 32 years; p < 0.001); popper users were significantly older than non-users (median = 34 vs. 28 years; p < 0.001). The odds of recreational drug use were higher among MSM diagnosed HIV-positive (vs. never tested; AOR 2.27, 95%CI 1.39-3.70). Use of poppers, and use of drugs associated with chemsex, were also higher among MSM diagnosed HIV-positive (vs. never tested; AOR 3.77, 95%CI 2.41-5.90, and AOR 5.87, 95%CI 3.08-11.18 respectively).

CONCLUSIONS

The prevalence of recreational drug use is higher among MSM than in the general population in Ireland, and it is particularly high among MSM diagnosed HIV-positive. Targeted harm reduction messages and preventive interventions are warranted to complement population-based approaches to reducing drug use in this population.

Inequalities in HIV testing uptake and needs among men who have sex with men living in Ireland: findings from an internet survey

OBJECTIVES

HIV disproportionately affects men who have sex with men (MSM) in Ireland. The aim of this study was to improve understanding of HIV testing among MSM living in Ireland to inform prevention and testing initiatives.

METHODS

We used data from the MSM Internet Survey Ireland 2015 (MISI 2015), a cross-sectional survey of MSM living in Ireland. We identified factors associated with never having tested for HIV using univariable and multivariable logistic regression. We identified preferred sites for future tests and examined the relationships between unmet HIV testing needs and socio-demographic groups.

RESULTS

More than one-third (n = 1006; 36%) of MSM had never tested for HIV. Multivariable logistic regression showed that untested men were more likely to be aged 18-24 years, live outside Dublin, have a lower level of education, be born in Ireland, identify as bisexual, be out to fewer people, and not have had sex with a man in the previous 12 months. The same groups of men also had the least knowledge about HIV and were least confident in accessing an HIV test. Men who had never tested for HIV were more likely to prefer testing by their general practitioner (GP) or using home sampling HIV kits and less likely to prefer testing in a sexual health clinic.

CONCLUSIONS

HIV prevention and testing programmes for MSM should be targeted towards younger men, those living outside Dublin and those with lower levels of education. We recommend increased promotion and availability of free HIV testing services in a range of clinical and nonclinical settings (including self-sampling and home testing).

Increased exposure of plankton to arsenic in contaminated weakly-stratified lakes

Arsenic, a priority Superfund contaminant and carcinogen, is a legacy pollutant impacting aquatic ecosystems in urban lakes downwind of the former ASARCO copper smelter in Ruston, WA, now a Superfund site. We examined the mobility of arsenic from contaminated sediments and arsenic bioaccumulation in phytoplankton and zooplankton in lakes with varying mixing regimes. In lakes with strong seasonal thermal stratification, high aqueous arsenic concentrations were limited to anoxic bottom waters that formed during summer stratification, and arsenic concentrations were low in oxic surface waters. However, in weakly-stratified lakes, the entire water column, including the fully oxic surface waters, had elevated concentrations of arsenic (up to 30μgL-1) during the summer. We found enhanced trophic transfer of arsenic through the base of the aquatic food web in weakly-stratified lakes; plankton in these lakes accumulated up to an order of magnitude more arsenic on multiple sampling days than plankton in stratified lakes with similar levels of contamination. We posit that greater bioaccumulation in weakly-stratified lakes was due to elevated arsenic in oxic waters. Aquatic life primarily inhabits oxic waters and in the oxic water column of weakly-stratified lakes arsenic was speciated as arsenate, which is readily taken up by phytoplankton because of its structural similarities to phosphate. Our study indicates that mobilization of arsenic from lake sediments into overlying oxic water columns in weakly-stratified lakes leads to increased arsenic exposure and uptake at the base of the aquatic food web.

Alternation between short- and long photoperiod reveals hypothalamic gene regulation linked to seasonal body weight changes in Djungarian hamsters (Phodopus sungorus)

Djungarian hamsters are able to reduce their body weight by more than 30% in anticipation of the winter season. This particular adaptation to extreme environmental conditions is primarily driven by a natural reduction in day length and conserved under laboratory conditions. We used this animal model to investigate hypothalamic gene expression linked to body weight regulation behind this physiological phenomenon. After an initial collective short photoperiod (SP) adaptation for 14 weeks from a preceding long photoperiod (LP), hamsters were re-exposed to LP for either 6 or 14 weeks, followed by a second re-exposure to SP for 8 weeks. Our data showed that re-exposure to LP led to an increase in body weight. In the hypothalamus Dio2, Vimentin, Crbp1 and Grp50 expression increased, whereas expression of Dio3, Mct8 and Srif decreased. The changes in body weight and gene expression were reversible in most hamsters after a further re-exposure to SP following 6 or 14 weeks in LP. Interestingly, after 14 weeks in LP, body weight loss was pronounced in six hamsters re-exposed to SP, but five hamsters did not respond. In nonresponding hamsters, a different gene expression pattern was manifested, with the exception of Dio2, which was reduced not only in SP re-exposed hamsters, but also in hamsters maintained in LP. Taken together, these data suggest that body weight regulation appears to be tightly linked to a co-ordinated regulation of several genes in the hypothalamus, including those involved in thyroid hormone metabolism.

Investigation of the First Seven Reported Cases of Candida auris, a Globally Emerging Invasive, Multidrug-Resistant Fungus-United States, May 2013-August 2016

November 11, 2016/65(44);1234-1237. What is already known about this topic? Candida auris is an emerging pathogenic fungus that has been reported from at least a dozen countries on four continents during 2009-2015. The organism is difficult to identify using traditional biochemical methods, some isolates have been found to be resistant to all three major classes of antifungal medications, and C. auris has caused health care-associated outbreaks. What is added by this report? This is the first description of C. auris cases in the United States. C. auris appears to have emerged in the United States only in the last few years, and U.S. isolates are related to isolates from South America and South Asia. Evidence from U.S. case investigations suggests likely transmission of the organism occurred in health care settings. What are the implications for public health practice? It is important that U.S. laboratories accurately identify C. auris and for health care facilities to implement recommended infection control practices to prevent the spread of C. auris. Local and state health departments and CDC should be notified of possible cases of C. auris and of isolates of C. haemulonii and Candida spp. that cannot be identified after routine testing.

Somatostatin Agonist Pasireotide Inhibits Exercise-Stimulated Growth in the Male Siberian Hamster (Phodopus sungorus)

The Siberian hamster (Phodopus sungorus) is a seasonal mammal, exhibiting a suite of physiologically and behaviourally distinct traits dependent on the time of year and governed by changes in perceived day length (photoperiod). These attributes include significant weight loss, reduced food intake, gonadal atrophy and pelage change with short-day photoperiod as in winter. The central mechanisms driving seasonal phenotype change during winter are mediated by a reduced availability of hypothalamic triiodothyronine (T3), although the downstream mechanisms responsible for physiological and behavioural changes are yet to be fully clarified. With access to a running wheel (RW) in short photoperiod, Siberian hamsters that have undergone photoperiod-mediated weight loss over-ride photoperiod-drive for reduced body weight and regain weight similar to a hamster held in long days. These changes occur despite retaining the majority of hypothalamic gene expression profiles appropriate for short-day hamsters. Utilising the somatostatin agonist pasireotide, we recently provided evidence for an involvement of the growth hormone (GH) axis in the seasonal regulation of bodyweight. In the present study, we employed pasireotide to test for the possible involvement of the GH axis in RW-induced body weight regulation. Pasireotide successfully inhibited exercise-stimulated growth in short-day hamsters and this was accompanied by altered hypothalamic gene expression of key GH axis components. Our data provide support for an involvement of the GH axis in the RW response in Siberian hamsters.

Seasonal Control of Mammalian Energy Balance: Recent Advances in the Understanding of Daily Torpor and Hibernation

Endothermic mammals and birds require intensive energy turnover to sustain high body temperatures and metabolic rates. To cope with the energetic bottlenecks associated with the change of seasons, and to minimise energy expenditure, complex mechanisms and strategies are used, such as daily torpor and hibernation. During torpor, metabolic depression and low body temperatures save energy. However, these bouts of torpor, lasting for hours to weeks, are interrupted by active 'euthermic' phases with high body temperatures. These dynamic transitions require precise communication between the brain and peripheral tissues to defend rheostasis in energetics, body mass and body temperature. The hypothalamus appears to be the major control centre in the brain, coordinating energy metabolism and body temperature. The sympathetic nervous system controls body temperature by adjustments of shivering and nonshivering thermogenesis, with the latter being primarily executed by brown adipose tissue. Over the last decade, comparative physiologists have put forward integrative studies on the ecophysiology, biochemistry and molecular regulation of energy balance in response to seasonal challenges, food availability and ambient temperature. Mammals coping with such environments comprise excellent model organisms for studying the dynamic regulation of energy metabolism. Beyond the understanding of how animals survive in nature, these studies also uncover general mechanisms of mammalian energy homeostasis. This research will benefit efforts of translational medicine aiming to combat emerging human metabolic disorders. The present review focuses on recent advances in the understanding of energy balance and its neuronal and endocrine control during the most extreme metabolic fluctuations in nature: daily torpor and hibernation.

Personality Differences According to Gender

This study reports on the gender differences in the responses to 34 questions comprising the Eysenck Personality Questionnaire, as recorded by 508 males and 873 females who constituted the American standardization group for the questionnaire. The mean difference on the resulting M-F scale is statistically significant, being 2.28 ± 0.30 for the British sample and 5.21 ± 0.26 for the American sample.

Disrupted seasonal biology impacts health, food security and ecosystems

The rhythm of life on earth is shaped by seasonal changes in the environment. Plants and animals show profound annual cycles in physiology, health, morphology, behaviour and demography in response to environmental cues. Seasonal biology impacts ecosystems and agriculture, with consequences for humans and biodiversity. Human populations show robust annual rhythms in health and well-being, and the birth month can have lasting effects that persist throughout life. This review emphasizes the need for a better understanding of seasonal biology against the backdrop of its rapidly progressing disruption through climate change, human lifestyles and other anthropogenic impact. Climate change is modifying annual rhythms to which numerous organisms have adapted, with potential consequences for industries relating to health, ecosystems and food security. Disconcertingly, human lifestyles under artificial conditions of eternal summer provide the most extreme example for disconnect from natural seasons, making humans vulnerable to increased morbidity and mortality. In this review, we introduce scenarios of seasonal disruption, highlight key aspects of seasonal biology and summarize from biomedical, anthropological, veterinary, agricultural and environmental perspectives the recent evidence for seasonal desynchronization between environmental factors and internal rhythms. Because annual rhythms are pervasive across biological systems, they provide a common framework for trans-disciplinary research.

Routine versus selective histological examination after cholecystectomy to exclude incidental gallbladder carcinoma

Introduction Gallstone disease is treated commonly with cholecystectomy. Malignant disease of the gallbladder may present similarly and has a poor prognosis. It is common for cholecystectomy specimens to be sent for histological examination to exclude malignancy. However, the incidence of incidental gallbladder carcinoma (IGBC) is low and it has therefore been suggested that macroscopic inspection of the gallbladder by the surgeon, followed by selective histological examination of abnormal specimens, may be safe and cost saving. Methods All cholecystectomies performed between 1 May 2003 and 1 September 2009 were identified from clinical coding. Pathology records were used to identify gallbladder malignancies; these were searched manually to identify IGBC. Pathology reports and case notes were cross-referenced to determine whether there were macroscopic abnormalities present. Annual cost savings were estimated by comparing the number of gallbladder specimens over one year (May 2013 - April 2014) with the total number of cholecystectomies performed in that time. Results Of 4,776 cholecystectomies identified, 12 (0.25%) were cases of IGBC. These cases had a higher median age (68 vs 54 years, p<0.001) and a higher proportion were emergency operations (50% vs 12%, p<0.001). All cases had some form of macroscopic abnormality, most commonly wall thickening (n=6, 50%). Only two cases (17%) had a visible tumour present. Conclusions All cases of IGBC in this study had a macroscopically abnormal gallbladder. Our findings suggest it is safe to adopt a selective approach to histological examination. Savings of almost £20,500 per annum have been achieved.

Somatostatin Agonist Pasireotide Promotes a Physiological State Resembling Short-Day Acclimation in the Photoperiodic Male Siberian Hamster (Phodopus sungorus)

The timing of growth in seasonal mammals is inextricably linked to food availability. This is exemplified in the Siberian hamster (Phodopus sungorus), which uses the annual cycle of photoperiod to optimally programme energy expenditure in anticipation of seasonal fluctuations in food resources. During the autumn, energy expenditure is progressively minimised by physiological adaptations, including a 30% reduction in body mass, comprising a reduction in both fat and lean tissues. However, the mechanistic basis of this adaptation is still unexplained. We hypothesised that growth hormone (GH) was a likely candidate to underpin these reversible changes in body mass. Administration of pasireotide, a long-acting somatostatin receptor agonist developed for the treatment of acromegaly, to male hamsters under a long-day (LD) photoperiod produced a body weight loss. This comprised a reduction in lean and fat mass, including kidneys, testes and brown adipose tissue, typically found in short-day (SD) housed hamsters. Furthermore, when administered to hamsters switched from SD to LD, pasireotide retarded the body weight increase compared to vehicle-treated hamsters. Pasireotide did not alter photoperiod-mediated changes in hypothalamic energy balance gene expression but altered the expression of Srif mRNA expression in the periventricular nucleus and Ghrh mRNA expression in the arcuate nucleus consistent with a reduction in GH feedback and concurrent with reduced serum insulin-like growth factor-1. Conversely, GH treatment of SD hamsters increased body mass, which included increased mass of liver and kidneys. Together, these data indicate a role for the GH axis in the determination of seasonal body mass of the Siberian hamster.

NFκB signaling is essential for the lipopolysaccharide-induced increase of type 2 deiodinase in tanycytes

The enzyme type 2 deiodinase (D2) is a major determinant of T₃ production in the central nervous system. It is highly expressed in tanycytes, a specialized cell type lining the wall of the third ventricle. During acute inflammation, the expression of D2 in tanycytes is up-regulated by a mechanism that is poorly understood at present, but we hypothesized that cJun N-terminal kinase 1 (JNK1) and v-rel avian reticuloendotheliosis viral oncogene homolog A (RelA) (the 65 kD subunit of NFκB) inflammatory signal transduction pathways are involved. In a mouse model for acute inflammation, we studied the effects of lipopolysaccharide (LPS) on mRNA expression of D2, JNK1, and RelA in the periventricular area (PE) and the arcuate nucleus-median eminence of the hypothalamus. We next investigated LPS-induced D2 expression in primary tanycyte cell cultures. In the PE, the expression of D2 was increased by LPS. In the arcuate nucleus, but not in the PE, we found increased RelA mRNA expression. Likewise, LPS increased D2 and RelA mRNA expression in primary tanycyte cell cultures, whereas JNK1 mRNA expression did not change. Phosphorylation of RelA and JNK1 was increased in tanycyte cell cultures 15-60 minutes after LPS stimulation, confirming activation of these pathways. Finally, inhibition of RelA with the chemical inhibitors sulfasalazine and 4-Methyl-N¹-(3-phenylpropyl)benzene-1,2-diamine (JSH-23) in tanycyte cell cultures prevented the LPS-induced D2 increase. We conclude that NFκB signaling is essential for the up-regulation of D2 in tanycytes during inflammation.

The connected health of cardiovascular medicine: current status and future directions

The technologies of cardiovascular connected health stand to dramatically alter the management and prevention of cardiovascular disease, a worldwide leading cause of death. The American Heart Association has outlined seven key health metrics including physical activity, adequate blood pressure control, weight and a healthy diet, which lie at the core of cardiovascular disease management. Controlling these metrics has been demonstrated to result in substantial reductions in cardiovascular mortality. These metrics are ideally suited to a connected health management strategy involving enhanced patient empowerment and augmented physician engagement. As more patients and healthcare providers adopt technologies that allow for self-monitoring and point-of-care diagnostics, the physician has access to a greater depth of data concerning their patient's health and how best to influence it.

Photoperiod-dependent regulation of carboxypeptidase E affects the selective processing of neuropeptides in the seasonal Siberian hamster (Phodopus sungorus)

The production of bioactive peptides from biologically inactive precursors involves extensive post-translational processing, including enzymatic cleavage by proteolytic peptidases. Endoproteolytic prohormone-convertases initially cleave the precursors of many neuropeptides at specific amino acid sequences to generate intermediates with basic amino acid extensions on their C-termini. Subsequently, the related exopeptidases, carboxypeptidases D and E (CPD and CPE), are responsible for removing these amino acids before the peptides achieve biological activity. We investigated the effect of photoperiod on the processing of the neuropeptide precursor pro-opiomelanocortin (POMC) and its derived neuropeptides, α-melanocyte-stimulating hormone (MSH) and β-endorphin (END), within the hypothalamus of the seasonal Siberian hamster (Phodopus sungorus). We thus compared hypothalamic distribution of CPD, CPE, α-MSH and β-END using immunohistochemistry and measured the enzyme activity of CPE and concentrations of C-terminally cleaved α-MSH in short-day (SD; 8 : 16 h light/dark) and long-day (LD; 16 : 8 h light/dark) acclimatised hamsters. Increased immunoreactivity (-IR) of CPE, as well as higher CPE activity, was observed in SD. This increase was accompanied by more β-END-IR cells and substantially higher levels of C- terminally cleaved α-MSH, as determined by radioimmunoassay. Our results suggest that exoproteolytic cleavage of POMC-derived neuropeptides is tightly regulated by photoperiod in the Siberian hamster. Higher levels of biological active α-MSH- and β-END in SD are consistent with the hypothesis that post-translational processing is a key event in the regulation of seasonal energy balance.

Increased responses to the actions of fibroblast growth factor 21 on energy balance and body weight in a seasonal model of adiposity

The present study aimed to investigate the actions of fibroblast growth factor 21 (FGF21) on energy balance in a natural model of relative fatness, the Siberian hamster. Hamsters were studied under long days (LD) to promote weight gain, or short days to induce weight loss, and treated with rhFGF21 (3 mg/kg/day) via s.c. minipumps for 14 days. On days 7-9, detailed assessments of ingestive behaviour, metabolic gas exchange and locomotor activity were made. FGF21 caused substantial (P < 0.0001) weight loss in the fat LD state but not in the lean SD state: at the end of the study, FGF21-treated hamsters in LD lost 18% of body weight compared to vehicle controls, which is comparable to the natural body weight loss observed in SD. Epididymal fat pads, a correlate of total carcass fat content, were reduced by 19% in FGF21 treated hamsters in LD, whereas no difference was found in SD. Body weight loss in LD was associated with a reduction in food intake (P < 0.001) and a decreased respiratory exchange ratio (P < 0.001), indicating increased fat oxidation. Treatment with FGF21 maintained the normal nocturnal increase in oxygen consumption and carbon dioxide production into the early light phase in hamsters in LD, indicating increased energy expenditure, although locomotor activity was unaffected. These data suggest a greater efficacy of FGF21 in hamsters in LD compared to those in SD, which is consistent with both the peripheral and possibly central actions of FGF21 with respect to promoting a lean phenotype. The observed differences in FGF21 sensitivity may relate to day length-induced changes in adipose tissue mass.

Hypothalamic gene expression rapidly changes in response to photoperiod in juvenile Siberian hamsters (Phodopus sungorus)

Siberian hamsters are seasonal mammals that survive a winter climate by making adaptations in physiology and behaviour. This includes gonadal atrophy, reduced food intake and body weight. The underlying central mechanisms responsible for the physiological adaptations are not fully established but involve reducing hypothalamic tri-iodthyronine (T3) levels. Juvenile Siberian hamsters born or raised in short days (SD) respond in a similar manner, although with an inhibition of gonadal development and growth instead of reversing an established long day (LD) phenotype. Using juvenile male hamsters, the present study aimed to investigate whether the central mechanisms are similar before the establishment of the mature LD phenotype. By in situ hybridisation, we examined the response of genes involved in thyroid hormone (Dio2 and Dio3, which determine hypothalamic T3 levels) and glucose/glutamate metabolism in the ependymal layer, histamine H3 receptor and VGF as representatives of the highly responsive dorsomedial posterior arcuate nucleus (dmpARC), and somatostatin, a hypothalamic neuropeptide involved in regulating the growth axis. Differential gene expression of type 2 and type 3 deiodinase in the ependymal layer, histamine H3 receptor in the dmpARC and somatostatin in the ARC was established by the eighth day in SD. These changes are followed by alterations in glucose metabolism related genes in the ependymal layer by day 16 and increased secretogranin expression in the dmpARC by day 32. In conclusion, our data demonstrate similar but rapid and highly responsive changes in gene expression in the brain of juvenile Siberian hamsters in response to a switch from LD to SD. The data also provide a temporal definition of gene expression changes relative to physiological adaptations of body weight and testicular development and highlight the likely importance of thyroid hormone availability as an early event in the adaptation of physiology to a winter climate in juvenile Siberian hamsters.

Short-days induce weight loss in Siberian hamsters despite overexpression of the agouti-related peptide gene

Many vertebrates express profound annual cycles of body fattening, although it is not clear whether these represent differential activity of the central pathways known to mediate homeostatic control of food intake and energy expenditure, or whether the recent discovery of a major role for pars tuberalis-ependymal signalling points towards novel mechanisms. We examined this in the Siberian hamster (Phodopus sungorus) by using gene transfection to up-regulate a major orexigenic peptide, agouti-related peptide (AgRP), and then determined whether this increased anabolic drive could prevent the short-day induced winter catabolic state. Infusions of a recombinant adeno-associated virus encoding an AgRP construct into the hypothalamus of hamsters in the long-day obese phase of their seasonal cycle produced a 20% gain in body weight over 6 weeks compared to hamsters receiving a control reporter construct, reflecting a significant increase in food intake and a significant decrease in energy expenditure. However, all hamsters showed a significant, prolonged decrease in body weight when exposed to short photoperiods, despite the hamsters expressing the AgRP construct maintaining a higher food intake and lower energy expenditure relative to the control hamsters. Visualisation of the green fluorescent protein reporter and analysis of AgRP-immunoreactivity confirmed widespread expression of the construct in the hypothalamus, which was maintained for the 21-week duration of the study. In conclusion, the over-expression of AgRP in the hypothalamus produced a profoundly obese state but did not block the seasonal catabolic response, suggesting a separation of rheostatic mechanisms in seasonality from those maintaining homeostasis of energy metabolism.

Inhibin betaB expression in murine adipose tissue and its regulation by leptin, insulin and dexamethasone

Inhibin betaB (INHBB; coding for the activin betaB subunit) has previously been identified in both human and rodent adipose tissue and using Taqman real-time PCR with specific primers we confirm the expression of INHBB mRNA in rodent adipose tissue. Expression of INHBB in murine epididymal adipose tissue was higher than in any of the other tissues studied and appears to be regulated by changes in energy balance and leptin. It was increased fourfold in the epididymal fat depot of ob/ob mice compared with the same fat depot in lean mice. The i.p. administration of leptin in obese ob/ob mice decreases the expression of INHBB. In human adipose tissue, INHBB is reduced by weight loss. In keeping with this, we demonstrate that INHBB expression in murine adipose tissue is decreased in fasting and increased upon refeeding. We show that INHBB is expressed in both the mature adipocyte and the stromal vascular fraction of adipose tissue. INHBB increases with the differentiation of pre-adipocytes into mature adipocytes in the 3T3-L1 cell line. In differentiated 3T3-L1 adipocytes, where receptors to activin have been previously reported, insulin increases the expression of INHBB, while dexamethasone decreases the expression of INHBB when compared with untreated control cells. Taken together, these results suggest that the regulation of INHBB expression in adipose tissue may play a physiological role in energy balance or the insulin insensitivity associated with obesity.

Short photoperiod-induced decrease of histamine H3 receptors facilitates activation of hypothalamic neurons in the Siberian hamster

Nonhibernating seasonal mammals have adapted to temporal changes in food availability through behavioral and physiological mechanisms to store food and energy during times of predictable plenty and conserve energy during predicted shortage. Little is known, however, of the hypothalamic neuronal events that lead to a change in behavior or physiology. Here we show for the first time that a shift from long summer-like to short winter-like photoperiod, which induces physiological adaptation to winter in the Siberian hamster, including a body weight decrease of up to 30%, increases neuronal activity in the dorsomedial region of the arcuate nucleus (dmpARC) assessed by electrophysiological patch-clamping recording. Increased neuronal activity in short days is dependent on a photoperiod-driven down-regulation of H3 receptor expression and can be mimicked in long-day dmpARC neurons by the application of the H3 receptor antagonist, clobenproprit. Short-day activation of dmpARC neurons results in increased c-Fos expression. Tract tracing with the trans-synaptic retrograde tracer, pseudorabies virus, delivered into adipose tissue reveals a multisynaptic neuronal sympathetic outflow from dmpARC to white adipose tissue. These data strongly suggest that increased activity of dmpARC neurons, as a consequence of down-regulation of the histamine H3 receptor, contributes to the physiological adaptation of body weight regulation in seasonal photoperiod.