Diurnal variations of cold-induced thermogenesis in young, healthy adults: a randomized crossover trial

Background: Harnessing cold-induced thermogenesis (CIT) and brown adipose tissue (BAT) activity has been proposed as a means of counteracting a positive energy balance, and thus of combating obesity and its related comorbidities. However, it has remained unclear whether CIT and BAT activity show diurnal variation in humans -knowledge that might allow treatments based on these factors to be time-optimized.Methods: A randomized crossover experiment was designed to examine whether CIT shows morning/evening variation in young, healthy adults (n = 14, 5 women). On the first experimental day, subjects' shivering thresholds were determined following a cooling protocol. After z96 h had elapsed, the sub-jects then returned on two further days (approx. 48 h apart) at 08:00 h or 18:00 in random order. On both the latter days, the resting energy expenditure (REE) was measured before the subjects underwent personalized cold exposure (i.e., according to their shivering threshold). CIT was then assessed for 60 min by indirect calorimetry. In an independent cross-sectional study (n = 133, 88 women), subjects came to the laboratory between 8:00 and 18:00 h and their BAT F-18-fluordeoxyglucose (F-18-FDG) uptake was assessed after personalized cold stimulation.Results: Both the REE and CIT were similar in the morning and evening (all P > 0.05). Indeed, 60 min of personalized-mild cold exposure in the morning or evening elicited a similar change in energy expen-diture (16.8 +/- 12.8 vs. 15.7 +/- 15.1% increase above REE, P = 0.72). BAT F-18-FDG uptake was also similar in the morning, evening and afternoon (all P > 0.05).Conclusion: CIT does not appear to show morning/evening variation in young healthy adults, with the current study design and methodology. BAT F-18-FDG uptake appears not to change across the day either, although experiments with a within-subject study design are needed to confirm these findings. (C) 2021 The Author(s). Published by Elsevier Ltd.Diabetes mellitus: pathophysiological changes and therap

Nipple-sparing mastectomy for breast cancer and risk-reducing surgery : the memorial sloan-kettering cancer center experience

Background: Nipple-sparing mastectomy (NSM) has been gathering increased recognition as an alternative to more traditional mastectomy approaches. Initially, questions concerning its oncologic safety limited the use of NSM. Nevertheless, mounting evidence supporting the practice of NSM for both prophylactic and oncologic purposes is leading to its more widespread use and broadened indications. Methods: Using a prospectively maintained database, we reviewed our experience of 353 NSM procedures performed in 200 patients over the past 10 years. Results: The indications for surgery were:196 prophylactic risk-reduction (55.5%), 74 ductal carcinoma in situ (DCIS) (20.8%), 82 invasive cancer (23.2%), and 1 phyllodes tumor (0.5%). The nipple areolar complex (NAC) was entirely preserved in 341 mastectomies (96.7%). There were 11 patients (3.1%) who were found to have cancer at the nipple margin, warranting further excision. A total of 69 breasts (19.5%) had some degree of skin desquamation or necrosis, but only 12 (3.3%) required operative debridement, of which 3 breasts (1%) necessitated removal of a breast implant. Also, 6 patients (2%) were treated for infection. Of the 196 prophylactic NSMs, 11 specimens (5.6%) were found to harbor occult cancer (8 DCIS and 3 invasive cancers). One patient who underwent NSM for invasive ductal carcinoma in 2006 developed metastatic disease to her brain. No other recurrences are attributable to the 353 NSMs. Conclusions: The trends demonstrate the increasing acceptance of NSM as a prophylactic procedure as well as for therapeutic purposes. Although NSM is not standard, our experience supports the selective use of NSM in both prophylactic and malignant settings

Use Of Chemically Modified Silica With β-diketoamine Groups For Separation Of α-lactoalbumin From Bovine Milk Whey By Affinity Chromatography

Silica gel surface was chemically modified with β-diketoamine groups by reacting the silanol from the silica surface with 3-aminopropyl-triethoxysilane and 3-bromopentanedione. With this material, copper ions were adsorbed from aqueous solutions. The chemical analysis of the silica-gel-immobilized acetylacetone provided a quantity of 0.67 mmol g-1 of organic groups attached to the support and 0.63 mmol g-1 of copper. This material was used as a stationary phase in IMAC (immobilized metal affinity chromatography), to separate α-lactoalbumin from bovine milk whey. The results showed an efficient separation in the chromatographic column. The possibility of reutilization of the stationary phase was also investigated.1852313316Wiseman, A., (1985) "Handbook of Enzyme Biotechnology," 2nd Ed., , Ellis Horwood, Chichester, EnglandCampbell, M.K., (1991) Biochemistry, , International ed. Saunders, PhiladelphiaDesai, M.A., (1990) J. Chem. Tech. Biotechnol., 48, p. 105Cuatrecasas, P., Wilchek, M., Anfinsen, C.B., (1968) Proc. Nat. Acad. Sci., 61, p. 636Boyer, R.F., (1991) J. Chem. Educ., 68, p. 430Walters, R.R., (1985) Anal. Chem., 57, pp. 1099AAdamson, A.W., (1976) "Physical Chemistry of Surfaces," 3rd Ed., , Wiley, New YorkIler, R.K., (1979) The Chemistry of Silica, , Wiley, New YorkLisichkin, G.V., Kudryatsev, G.V., Nesterenko, P.N., (1983) J. Anal. Chem. USSR, 38, p. 1288Deschler, V., Kleinschmit, P., Panster, P., (1986) Angew Chem. Int. Ed., 25, p. 236Unger, K., (1972) Angew Chem. Int. Ed., 11, p. 267Boudart, M., (1974) Chem. Tech., p. 370Kudryatsev, G.V., Lisichkin, G.V., Ivanov, V.M., (1983) J. Anal. Chem. USSR, 38, p. 16Neimar, I.E., (1987) Theor. Exp. Chem., 23, p. 539Vollet, D.R., Moreira, J.C., Kubota, L.T., Varella, J.A., Gushikem, Y., (1989) Colloids Surf., 40, p. 1Boumabraz, M., Davydov, V.Y., Kiselev, A.V., (1982) Chromatographia, 15, p. 751Sander, L.C., Wise, S.A., (1987) Crit. Rev. Anal. Chem., 18, p. 299Suckling, C.J., (1977) Chem. Soc. Rev., 6, p. 215Filipov, A.P., Zyatkovskii, V.M., Karpenko, I.A., (1981) Theor. Exp. Chem., 17, p. 278Sokozhenkin, P.M., Semikopnyi, A.I., Sharf, V.Z., Lisichkin, G.V., (1988) Russian J. Phys. Chem., 62, p. 218Davis, B.J., (1964) Ann. N. Y. Acad. Sci., 121, p. 404Ornstein, L., (1964) Ann. N. Y. Acad. Sci., 121, p. 321Airoldi, C., Alcantara, E.F.C., (1995) Thermochim. Acta, 259, p. 95Airoldi, C., Alcantara, E.F.C., (1995) J. Chem. Thermodyn., 27, p. 623Huynh, T.K.X., Lederer, M., (1993) J. Chromatogr., 645, p. 185Iamamoto, M.S., Gushikem, Y., (1989) Analyst, 114, p. 98

Association between brown adipose tissue and bone mineral density in humans

Background Brown adipose tissue (BAT) seems to play a role in bone morphogenesis. A negative association has been reported between BAT and bone mineral density (BMD) in women, but not in men. A panel of experts has recently published a set of recommendations for BAT assessment, and thus, to re-address previously reported associations is needed. This study aimed to investigate the association between cold-induced BAT (18) F-Fluorodeoxyglucose (F-18-FDG) uptake and BMD in young healthy adults.Methods Ninety-eight healthy adults (68 women; 22 +/- 2.2 years old; 24.3 +/- 4.5 kg/m(2)) cold-induced BAT was assessed by means of an F-18-FDG positron emission tomography-computed tomography (PET-CT) scan preceded by a personalized cold stimulation. The cold exposure consisted in 2 h in a mild cold room at 19.5-20 degrees C wearing a water perfused cooling vest set 4 degrees C above the individual shivering threshold. Total body and lumbar spine BMD were assessed by a whole-body DXA scan.Results We found no association between BMD and cold-induced BAT volume, mean, and maximal activity (all P>0.1) in neither young and healthy men nor women. These results remained unchanged when adjusting by height, by body composition, and by objectively assessed physical activity. Sensitivity analyses using the criteria to quantify cold-induced BAT-related parameters applied in previous studies did not change the results.Conclusions In summary, our study shows that there is no association between cold-induced BAT and BMD in young healthy adults. Moreover, our data support the notion that previously shown associations between BAT and BMD in healthy non-calorically restricted individuals, could be driven by methodological issues related to BAT assessment and/or sample size limitations.Diabetes mellitus: pathophysiological changes and therap

A New Personalized Cooling Protocol to Activate Brown Adipose Tissue in Young Adults

Diabetes mellitus: pathophysiological changes and therap

Association of Objectively Measured Physical Activity With Brown Adipose Tissue Volume and Activity in Young Adults

Purpose: Human brown adipose tissue (BAT) has gained considerable attention as a potential therapeutic target for obesity and type 2 diabetes; however, whether physical activity (PA) might be an efficient stimulus to activate and recruit BAT remains to be ascertained. We aimed to examine whether objectively measured PA levels were associated with BAT volume and activity in young sedentary adults. We additionally examined the association of PA levels with the skeletal muscles activity.Methods: A total of 130 young healthy and sedentary adults (67% women; age, 21.9 +/- 2.1 years old; body mass index, 25 +/- 4.8 kg/m(2)) participated in this cross-sectional study. PA was objectively measured with a wrist-worn accelerometer for 7 consecutive days. Age-specific cut points were applied to classify wrist accelerations into sedentary time and different PA intensities (i.e., light, moderate, vigorous, moderate-vigorous). The participants underwent 2 hours of a personalized cold exposure to determine the cold-induced BAT volume and activity and the skeletal muscles activity by means of an F-18 fluorodeoxyglucose positron emission tomography combined with a CT scan.Results: Objectively measured PA intensity levels were neither associated with BAT volume and activity nor with the skeletal muscles activity (all P> 0.05). The results remained after adjusting for sex, waking time, and environmental temperature.Conclusions: Although PA plays an important role in the prevention of obesity and related comorbidities, it seems that other physiological mechanisms rather than brown adipocyte activation or recruitment might moderate its beneficial metabolic effects in young sedentary adults.Diabetes mellitus: pathophysiological changes and therap

Evidence of high F-18-fluorodeoxyglucose uptake in the subcutaneous adipose tissue of the dorsocervical area in young adults

Diabetes mellitus: pathophysiological changes and therap