OBJECTIVEBrown adipose tissue (BAT) is present in adult humans where it may be important in the prevention of obesity, although the main factors regulating its abundance are not well established. BAT demonstrates seasonal variation relating to ambient temperature and photoperiod in mammals. The objective of our study was therefore to determine whether seasonal variation in BAT activity in humans was more closely related to the prevailing photoperiod or temperature.RESEARCH DESIGN AND METHODSWe studied 3,614 consecutive patients who underwent positron emission tomography followed by computed tomography scans. The presence and location of BAT depots were documented and correlated with monthly changes in photoperiod and ambient temperature.RESULTSBAT activity was demonstrated in 167 (4.6%) scans. BAT was demonstrated in 52/724 scans (7.2%) in winter compared with 27/1,067 (2.5%) in summer months (P < 0.00001, χ2 test). Monthly changes in the occurrence of BAT were more closely related to differences in photoperiod (r2 = 0.876) rather than ambient temperature (r2 = 0.696). Individuals with serial scans also demonstrated strong seasonal variation in BAT activity (average standardized uptake value [SUVmax] 1.5 in July and 9.4 in January). BAT was also more common in female patients (female: n = 107, 7.2%; male: n = 60, 2.8%; P < 0.00001, χ2 test).CONCLUSIONSOur study demonstrates a very strong seasonal variation in the presence of BAT. This effect is more closely associated with photoperiod than ambient temperature, suggesting a previously undescribed mechanism for mediating BAT function in humans that could now potentially be recruited for the prevention or reversal of obesity.

The secretion of many hormones, including oxytocin, vasopressin and growth hormone, is not constant but shows a day-night rhythm. The suprachiasmatic nucleus (SCN) is thought to generate most mammalian biological rhythms and previous studies have reported suprachiasmatic efferents to the paraventricular nucleus (PVN) and the supraoptic nucleus (SON). We used in vivo extracellular electrophysiological techniques to show that the SCN also sends direct and indirect neural projections to the arcuate nucleus (ARC). This projection consisted of both excitatory and inhibitory components and may contribute to the entrainment of the rhythm in growth hormone secretion to the day-night cycle. Some SCN neurones appear to project to both the SON and the ARC. The SCN in turn receives excitatory and inhibitory inputs from the ARC and the peri-nuclear zone of the SON (peri-SON), which may provide feedback information, as well as allowing nonphotic entrainment of the SCN, for example, in response to feeding. Our data thus suggest extensive two-way connections between the SCN and its target nuclei which may contribute to the generation of day-night neuroendocrine rhythms. They also suggest the existence of indirect retinal projections to the ARC and PVN. We further investigated the retinal projection to the SCN. We were unable to demonstrate a significant difference in retinal input to those suprachiasmatic cells which had efferent projections to particular hypothalamic targets (SON and/or ARC), and those which did not.

It will be important to review the long-term results of larger trials.

Aspects of decision making, postoperative management, and complications routinely discussed with patients were investigated using a questionnaire completed by 141 hand surgeons of various grades who regularly manage Dupuytren disease. This account presents the results of this questionnaire study, and the literature is discussed in context. A brief description of operative technique in fasciectomy and dermofasciectomy is included. Thresholds for surgery did not differ greatly among the surgeons who completed the questionnaire. The training background and the number of operations performed by surgeons also did not generally influence surgical decision making. Postoperative care regimens were very similar. However, there was great variation in the complications routinely included in discussions with patients undergoing surgery for Dupuytren contracture. Recurrence and nerve damage were the only 2 mentioned by almost all surgeons. There was also diversity in what rates were quoted for complications, particularly recurrence (median 33%, range 0%-100%) and stiffness (median 10%, range 0%-100%).

Key Results1. Among a 787-patient cohort with confirmed COVID-19, three chest radiograph scores (BRIXIA, RALE, and percent opacification) all had good interrater reliability with intraclass correlations of 0.87, 0.86, and 0.72 respectively.2. Radiograph scores predicted intensive care unit (ICU) admission or death after COVID-19 diagnosis. A 50%-75% opacification (compared to 0%-25%) associated with a 2.2-fold increase in these outcomes among those eligible for ICU care after adjustment for clinical risk scoring. SummaryBRIXIA, RALE, and percent opacification produced reliable and reproducible COVID-19 chest radiograph severity scores that improved accuracy for predicting adverse outcomes when incorporated into ISARIC-4C mortality and NEWS2 clinical scoring systems. I n p r e s s ResultsAdmission chest radiographs of 50 patients (mean age, 74 years +/-16 [sd], 28 men) were scored by all 3 radiologists, with good inter-rater reliability for all scores (ICCs (95% CIs) of for RALE 0.87 (0.80, 0.92), BRIXIA 0.86 (0.76, 0.92), and percentage opacification 0.72 (0.48, 0.85)). Of 751 patients with chest radiograph, those with >75% opacification had a median time to ICU admission or death of just 1-2 days. Among 628 patients with data (median age 76 years (IQR 61 -84), and 344 were men), 50-75% opacification increased risk of ICU admission or death by twofold (1.6 -2.8), and over 75% opacification by 4 fold (3.4 -4.7), compared to a 0-25% opacification when adjusted for NEWS2 score. ConclusionBRIXIA, RALE, and percent opacification scores all reliably predicted adverse outcomes in SARS-CoV-2.

Ultrasound is a useful adjunct to mammography for the characterisation and biopsy of solid breast lesions. Protein expression profiling of breast cancer has identified specific subgroups with potential clinical, biological and therapeutic implications. The aim of this study was to determine the ultrasound correlates of these novel molecular classes of invasive breast cancer. The ultrasound findings in 358 patients with operable breast cancer were correlated with the previously described protein expression classes identified by our group using immunohistochemical (IHC) assessment of a large series of breast cancer cases in which 25 proteins of known relevance in breast cancer were assessed, including hormone receptors, HER2 status, basal and luminal markers, p53 and e-cadherin. The proportion of occult lesions was not significantly different in the two groups. Significant differences were noted between the two groups expressing luminal epithelial markers and hormone receptors (1 and 2), including a greater proportion of ill-defined, irregular and distally attenuating tumours in group 2. Tumours characterised by c-erbB2/MUC1 expression, with weak hormone receptor positivity (group 3) were also more likely to be ill defined. Tumours expressing basal markers (group 5) were less likely to have an echogenic halo. The ultrasound features of breast cancer show areas of significant correlation with molecular classes of invasive breast cancer identified by IHC analysis. The biological reasons for these findings and their implications regarding imaging protocols require further study and may enable improved detection of these lesions.

No abstract

As pleural thickening can have a benign or malignant cause, use of the appropriate imaging techniques is crucial to a correct diagnosis. The authors explore the options