Obesity-related perivascular adipose tissue damage is reversed by sustained weight loss in the rat

Objective – Perivascular adipose tissue (PVAT) exerts an anticontractile effect in response to various vasoconstrictor agonists and this is lost in obesity. A recent study reported that bariatric surgery reverses the damaging effects of obesity on PVAT function. However, PVAT function has not been characterised following weight loss induced by caloric restriction, which is often the first line treatment for obesity. Approach and Results – Contractility studies were performed using wire myography on small mesenteric arteries with and without PVAT from control, diet-induced obese, calorie restricted and sustained weight loss rats. Changes in the PVAT environment were assessed using immunohistochemistry. PVAT from healthy animals elicited an anticontractile effect in response to norepinephrine. This was abolished in diet-induced obesity through a mechanism involving increased local TNFα and reduced nitric oxide bioavailability within PVAT. Sustained weight loss led to improvement in PVAT function associated with restoration of adipocyte size, reduced TNFα and increased nitric oxide synthase function. This was associated with reversal of obesity-induced hypertension and normalisation of plasma adipokine levels, including leptin and insulin. Conclusions – We have shown that diet-induced weight loss reverses obesity-induced PVAT damage through a mechanism involving reduced inflammation and increased nitric oxide synthase activity within PVAT. These data reveal inflammation and nitric oxide synthase, particularly eNOS, as potential targets for the treatment of PVAT dysfunction associated with obesity and the metabolic syndrome

Restoring Perivascular Adipose Tissue Function in Obesity Using Exercise

From Springer Nature via Jisc Publications RouterHistory: accepted 2020-12-21, registration 2020-12-21, pub-electronic 2021-03-09, online 2021-03-09, pub-print 2021-12Publication status: PublishedFunder: British Heart Foundation; doi: http://dx.doi.org/10.13039/501100000274; Grant(s): FS/13/56/30645, FS/16/58/32734, PG/16/52/32229Abstract: Purpose: Perivascular adipose tissue (PVAT) exerts an anti-contractile effect which is vital in regulating vascular tone. This effect is mediated via sympathetic nervous stimulation of PVAT by a mechanism which involves noradrenaline uptake through organic cation transporter 3 (OCT3) and β3-adrenoceptor-mediated adiponectin release. In obesity, autonomic dysfunction occurs, which may result in a loss of PVAT function and subsequent vascular disease. Accordingly, we have investigated abnormalities in obese PVAT, and the potential for exercise in restoring function. Methods: Vascular contractility to electrical field stimulation (EFS) was assessed ex vivo in the presence of pharmacological tools in ±PVAT vessels from obese and exercised obese mice. Immunohistochemistry was used to detect changes in expression of β3-adrenoceptors, OCT3 and tumour necrosis factor-α (TNFα) in PVAT. Results: High fat feeding induced hypertension, hyperglycaemia, and hyperinsulinaemia, which was reversed using exercise, independent of weight loss. Obesity induced a loss of the PVAT anti-contractile effect, which could not be restored via β3-adrenoceptor activation. Moreover, adiponectin no longer exerts vasodilation. Additionally, exercise reversed PVAT dysfunction in obesity by reducing inflammation of PVAT and increasing β3-adrenoceptor and OCT3 expression, which were downregulated in obesity. Furthermore, the vasodilator effects of adiponectin were restored. Conclusion: Loss of neutrally mediated PVAT anti-contractile function in obesity will contribute to the development of hypertension and type II diabetes. Exercise training will restore function and treat the vascular complications of obesity

FAN1 controls mismatch repair complex assembly via MLH1 retention to stabilize CAG repeat expansion in Huntington's disease.

CAG repeat expansion in the HTT gene drives Huntington's disease (HD) pathogenesis and is modulated by DNA damage repair pathways. In this context, the interaction between FAN1, a DNA-structure-specific nuclease, and MLH1, member of the DNA mismatch repair pathway (MMR), is not defined. Here, we identify a highly conserved SPYF motif at the N terminus of FAN1 that binds to MLH1. Our data support a model where FAN1 has two distinct functions to stabilize CAG repeats. On one hand, it binds MLH1 to restrict its recruitment by MSH3, thus inhibiting the assembly of a functional MMR complex that would otherwise promote CAG repeat expansion. On the other hand, it promotes accurate repair via its nuclease activity. These data highlight a potential avenue for HD therapeutics in attenuating somatic expansion

Man of Letters, Literary Lady, Journalist or Reporter?

The enormous changes wrought in the British newspaper industry during the late nineteenth and early twentieth centuries brought about a revolution in newspaper reading habits, financing and influence, all aspects of which have been well-documented by historians of the press. But what of the contributor, particularly the freelance whose millions of words formed, mostly anonymously, the content of the new mass market press? How did writers negotiate changes in the literary marketplace during this time as editors demanded more ‘news’ and less in the way of whimsical paragraphing, and sketches, the traditional newspaper output of the professional man, or woman, of letters? Through the study of memoirs, correspondence and the fictional output of contributors to the press during this time, it is possible to discern the often fraught relations between writers and their most lucrative market

A Randomized Controlled Trial Comparing the Effects of Counseling and Alarm Device on HAART Adherence and Virologic Outcomes

Michael Chung and colleagues show that intensive early adherence counseling at HAART initiation resulted in sustained, significant impact on adherence and virologic treatment failure, whereas use of an alarm device had no effect

Teaching in the age of Covid-19—1 year later

This is an accepted manuscript of an article published by Springer in Postdigital Science and Education on 10/08/2021, available online: https://doi.org/10.1007/s42438-021-00243-7 The accepted version of the publication may differ from the final published version.Published onlin

Mammographic surveillance in women younger than 50 years who have a family history of breast cancer: tumour characteristics and projected effect on mortality in the prospective, single-arm, FH01 study.

BACKGROUND: Evidence supports a reduction in mortality from breast cancer with mammographic screening in the general population of women aged 40-49 years, but the effect of family history is not clear. We aimed to establish whether screening affects the disease stage and projected mortality of women younger than 50 years who have a clinically significant family history of breast cancer. METHODS: In the single-arm FH01 study, women at intermediate familial risk who were younger than 50 years were enrolled from 76 centres in the UK, and received yearly mammography. Women with BRCA mutations were not explicitly excluded, but would be rare in this group. To compare the FH01 cohort with women not receiving screening, two external comparison groups were used: the control group of the UK Age Trial (106,971 women aged 40-42 years at recruitment, from the general population [ie, average risk], followed up for 10 years), and a Dutch study of women with a family history of breast cancer (cancer cases aged 25-77 years, diagnosed 1980-2004). Study endpoints were size, node status, and histological grade of invasive tumours, and estimated mortality calculated from the Nottingham prognostic index (NPI) score, and adjusted for differences in underlying risk between the FH01 cohort and the control group of the UK Age Trial. This study is registered with the National Research Register, number N0484114809. FINDINGS: 6710 women were enrolled between Jan 16, 2003, and Feb 28, 2007, and received yearly mammography for a mean of 4 years (SD 2) up until Nov 30, 2009; surveillance and reporting of cancers is still underway. 136 women were diagnosed with breast cancer: 105 (77%) at screening, 28 (21%) symptomatically in the interval between screening events, and three (2%) symptomatically after failing to attend their latest mammogram. Invasive tumours in the FH01 study were significantly smaller (p=0·0094), less likely to be node positive (p=0·0083), and of more favourable grade (p=0·0072) than were those in the control group of the UK Age Trial, and were significantly less likely to be node positive than were tumours in the Dutch study (p=0·012). Mean NPI score was significantly lower in the FH01 cohort than in the control group of the UK Age Trial (p=0·00079) or the Dutch study (p<0·0001). After adjustment for underlying risk, predicted 10-year mortality was significantly lower in the FH01 cohort (1·10%) than in the control group of the UK Age Trial (1·38%), with relative risk of 0·80 (95% CI 0·66-0·96; p=0·022). INTERPRETATION: Yearly mammography in women with a medium familial risk of breast cancer is likely to be effective in prevention of deaths from breast cancer