Partitioning circadian transcription by SIRT6 leads to segregated control of cellular metabolism.

Circadian rhythms are intimately linked to cellular metabolism. Specifically, the NAD(+)-dependent deacetylase SIRT1, the founding member of the sirtuin family, contributes to clock function. Whereas SIRT1 exhibits diversity in deacetylation targets and subcellular localization, SIRT6 is the only constitutively chromatin-associated sirtuin and is prominently present at transcriptionally active genomic loci. Comparison of the hepatic circadian transcriptomes reveals that SIRT6 and SIRT1 separately control transcriptional specificity and therefore define distinctly partitioned classes of circadian genes. SIRT6 interacts with CLOCK:BMAL1 and, differently from SIRT1, governs their chromatin recruitment to circadian gene promoters. Moreover, SIRT6 controls circadian chromatin recruitment of SREBP-1, resulting in the cyclic regulation of genes implicated in fatty acid and cholesterol metabolism. This mechanism parallels a phenotypic disruption in fatty acid metabolism in SIRT6 null mice as revealed by circadian metabolome analyses. Thus, genomic partitioning by two independent sirtuins contributes to differential control of circadian metabolism.

Validation of a Skin Calorimeter to Determine the Heat Capacity and the Thermal Resistance of the Skin.

In vivo determination of the skin's thermal properties is of growing interest. Several types of sensors are being designed and tested. In this field, we have developed a skin calorimeter for the determination of the heat flow, the heat capacity and the thermal resistance of the skin. The calorimeter calibration consists of the determination of the parameters of the model we have chosen to represent the behavior of the device. This model considers the heat capacity and the thermal resistance of the skin, which depend on the case (body zone, subject, physical state, etc.) and also have a strong time dependence. Therefore, this work includes a validation study with reference materials. Finally, it is concluded that the heat capacity determined is a function of the thermal penetration depth of the measurement characteristics. In the case of high thermal conductivity materials in which the thermal penetration is nearly total, the heat capacity obtained coincides with that of the reference material sample.

Effects of temperature on metabolic rate and lower dissolved oxygen tolerance of juvenile speckled peacock bass Cichla temensis.

The speckled peacock bass Cichla temensis is a popular sport and food fish that generates substantial angling tourism and utilitarian harvest within its range. Its popularity and value make this species important for management and a potential aquaculture candidate for both fisheries enhancement and food fish production. However, little is known of optimal physiochemical conditions in natural habitats, which also are important for the development of hatchery protocols for handling, spawning and grow-out. Speckled peacock bass have been documented to have high sensitivity to extreme temperatures, but the metabolic underpinnings have not been evaluated. In this study, the effects of temperature (25, 30 and 35°C) on the standard metabolic rate (SMR) and lower dissolved oxygen tolerance (LDOT) of juvenile speckled peacock bass (mean ± standard error total length 153 ± 2 mm and wet weight 39.09 ± 1.37 g) were evaluated using intermittent respirometers after an acclimation period of 2 weeks. Speckled peacock bass had the highest SMR at 35°C (345.56 ± 19.89 mgO2  kg-1 h-1 ), followed by 30°C (208.16 ± 12.45 mgO2  kg-1 h-1 ) and 25°C (144.09 ± 10.43 mgO2  kg-1 h-1 ). Correspondingly, the Q10 , or rate of increase in aerobic metabolic rate (MO2 ) relative to 10°C, for 30-35°C was also greater (2.76) than from 25 to 30°C (2.08). Similarly, speckled peacock bass were the most sensitive to hypoxia at the warmest temperature, with an LDOT at pO2 of 90 mmHg (4.13 mg l-1 ) at 35°C compared to pO2 values of 45 mmHg (2.22 mg l-1 ) and 30 mmHg (1.61 mg l-1 ) at 30 and 25°C, respectively. These results indicate that speckled peacock bass are sensitive to temperatures near 35°C, therefore we recommend managing and rearing this species at 25-30°C.

The effects of temperature and salinity on the blood chemistry and survival of juvenile Atlantic tarpon Megalops atlanticus.

Atlantic tarpon Megalops atlanticus are highly migratory sportfish that support recreational fisheries throughout their range. In US waters, juveniles can be found in coastal and estuarine habitats along the Gulf of Mexico and Atlantic seaboard, with temperature limiting their northern latitudinal distribution. Juveniles may overwinter in these areas during the first several years of life. Low temperatures are known to cause mortality in adults, but the challenges of temperature are less understood for juveniles. Furthermore, salinity, which can change dramatically in these habitats, may have a synergistic effect with temperature. To examine the physiological effects of temperature and salinity on juvenile tarpon, wild fish were acclimated to a range of conditions that potentially occur in the northern range of their estuarine habitats. The haematology of juvenile tarpon was examined in two salinity (≤2 and ≥30 ppt) and temperature (15 and 25°C) treatments, followed by a low-temperature tolerance test. After 2 weeks in treatment conditions, blood samples were analysed for haematocrit, pH, red blood cell concentration, haemoglobin content and plasma osmolality. Increased plasma osmolality was observed in fish at low temperature (15°C compared to 25°C) and at high salinity (≥30 ppt compared to ≤2 ppt). Blood pH was increased at 15°C compared to 25°C, with the highest pH at 15°C and low salinity. Haemoglobin, haematocrit and red blood cell concentration were higher at 25°C than 15°C, with haemoglobin lowest at 15°C and low salinity. For the low-temperature tolerance test, all fish were acclimated to 15°C for 2 weeks, then transferred to separate tanks where temperature was gradually decreased at 0.9 ± 0.1°C/h until fish lost equilibrium. Fish at low salinity lost equilibrium more rapidly (1 ppt, 12.65 ± 0.46°C) than fish at high salinity (30 ppt, 11.26 ± 0.14°C). The results indicate juvenile tarpon are susceptible to low temperature, which is exacerbated by low salinity, findings useful in the assessment of juvenile tarpon overwintering habitat.

Who is open to change after the COVID-19 pandemic? Some insights from Germany.

The COVID-19 pandemic as a disruptive event was initially considered an opportunity for a transformation towards more sustainable lifestyles. In two telephone surveys with more than 1000 participants each, this study explored in October 2020 and May 2021 how people in Germany experienced the COVID-19 related lockdown restrictions. Specifically, the study investigated how the respondents felt their lives had been impaired during the pandemic, which changes they had experienced as particularly bothersome and which ones they perceived to be beneficial. A second objective was to analyze how these perceptions related to either the respondents' urge to return to "normal" or, in contrast, to their openness towards lifestyle changes. A third objective was to identify structural characteristics that would explain differences in perception and assessment of lifestyle changes. Overall, the study found that by 2021, the pandemic had impacted people more negatively than in 2020. Most respondents missed social contacts, traveling and cultural events. Among the positive changes, working from home and spending less money for useless things were particularly prominent. A third of the participants agreed that they would like to question their behavior before the pandemic and live more consciously. Apart from slight differences in gender, age and, most importantly, academic background, socio-economic characteristics hardly help explain why some people were more open to change than others. Therefore, a cluster analysis was conducted with the result that respondents with stronger pro-environmental attitudes were more open to change, no matter how much they felt affected by the pandemic. These findings indicate that when routines are disrupted, pro-environmental personal values and education contribute to the openness for alternative lifestyle choices.

Long-term outcomes of percutaneous versus surgical revascularization in patients with diabetes and left main coronary artery disease: A meta-analysis of randomized controlled trials.

BACKGROUND: The efficacy and safety of percutaneous coronary interventions (PCI) relative to coronary artery bypass grafting (CABG) in patients with diabetes and unprotected left main coronary artery disease (LMCAD) are not well established. OBJECTIVES: To perform a meta-analysis evaluating the long-term outcomes after PCI with drug-eluting stents (DES), as compared with CABG, in patients with diabetes and unprotected LMCAD. METHODS: MEDLINE, Cochrane, and Embase were searched for randomized controlled trials (RCTs) that reported outcomes after PCI with DES versus CABG in unprotected LMCAD among patients with diabetes. To evaluate the long-term effects of these interventions, we restricted this analysis to studies with a minimum follow-up period of 3 years. Risk ratios (RRs) with 95% confidence intervals (CIs) were pooled with a random-effects model. Quality assessment and risk of bias were performed according to Cochrane recommendations. RESULTS: Four RCTs with a total of 1080 patients were included, 553 (51.2%) of whom underwent PCI. There was no difference for individual outcomes of all-cause mortality (RR: 1.21; 95% CI: 0.86-1.71; p = .27; I2 = 28%), cardiovascular death (RR 1.29; 95% CI: 0.76-2.18; p = .34; I2 = 0%), or myocardial infarction (MI) (RR: 0.94; 95% CI: 0.61-1.45; p = .79; I2 = 0%). However, the risk of stroke was reduced with PCI relative to CABG (RR: 0.41; 95% CI: 0.18-0.94; p = .04; I2 = 0%), whereas the risk of any repeat revascularization was higher in the PCI group (RR: 1.99; 95% CI: 1.44-2.75; p < .001; I2 = 0%). The risk of the composite outcome of all-cause mortality, MI, stroke, or repeat revascularization was higher after PCI compared with CABG (RR: 1.30; 95% CI: 1.09-1.56; p = .004; I2 = 0%). CONCLUSION: In this meta-analysis with more than 1000 patients with diabetes and unprotected LMCAD followed for a minimum of 3 years, the incidence of repeat revascularization was higher among those treated with PCI, whereas the risk of stroke was higher in patients treated with CABG.

Rivaroxaban versus warfarin in patients with atrial fibrillation enrolled in Latin America: Insights from ROCKET AF.

BACKGROUND: ROCKET AF demonstrated the efficacy and safety of rivaroxaban compared with warfarin for the prevention of stroke and systemic embolism (SE) in patients with atrial fibrillation (AF). We examined baseline characteristics and outcomes in patients enrolled in Latin America compared with the rest of the world (ROW). METHODS: ROCKET AF enrolled 14,264 patients from 45 countries. Of these, 1,878 (13.2%) were from 7 Latin American countries. The clinical characteristics and outcomes (adjusted by baseline characteristics) of these patients were compared with 12,293 patients from the ROW. Treatment outcomes of rivaroxaban compared with warfarin were also stratified by region. RESULTS: The annual rate of stroke/SE was similar in those from Latin American and ROW (P= .63), but all-cause and vascular death were significantly higher than in ROW (HR 1.40, 95% CI 1.20-1.64; HR 1.38, 95% CI 1.14-1.68; P< .001). Rates of major or nonmajor clinically relevant bleeding tended to be lower in Latin America (HR 0.89, 95% CI 0.80-1.0; P= .05). Rates of stroke and/or SE were similar with rivaroxaban and warfarin in patients from Latin America and ROW (HR 0.83, 95% CI 0.54-1.29 vs HR 0.89, 95% CI 0.75-1.07; interaction P= .77). CONCLUSIONS: Patients with AF in Latin America had similar rates of stroke and/or SE, higher rates of vascular death, and lower rates of bleeding compared with patients in the ROW. The effect of rivaroxaban compared with warfarin in Latin America was similar to the ROW. Further studies analyzing patient- and country-specific determinants of these regional differences in Latin America are warranted.

Covid-19 and small lodging establishments: A break-even calibration analysis (CBA) model.

The COVID-19 pandemic foiled the hospitality industry offering no clear insight as to what to expect regarding the emergence of possible new industry standards as likely corollaries of the pandemic. The accommodation sector is one of the most affected sectors in the hospitality industry, especially small lodging establishments incurring the most dramatic brunt of the pandemic's long-tail effects. This study employed a breakeven (BC) analysis to examine the pandemic's opportunity cost and the financial resilience efforts that SLEs should undertake to bounce back or bounce forward. The case study centers on the Superior Small Lodgings (SSL) of Florida, USA. The results suggest that the opportunity cost varies depending on the SLE profiles, and hence resilience approaches should consider heterogeneous business responses.

Network meta-analysis of His bundle, biventricular, or right ventricular pacing as a primary strategy for advanced atrioventricular conduction disease with normal or mildly reduced ejection fraction.

INTRODUCTION: Although right ventricular pacing (RVP) may impair ventricular function, it is commonly used for advanced atrioventricular block (AVB) and normal or mildly reduced ejection fraction (EF). We aimed to compare His bundle pacing (HBP), biventricular pacing (BiVP), and RVP for advanced AVB in patients with normal or mildly reduced EF. METHODS AND RESULTS: MEDLINE, Embase, Cochrane CENTRAL, ClinicalTrials.gov, Scopus, and Web of Science were searched. Outcomes were all-cause death, heart failure hospitalizations (HFH), EF, left ventricular volumes, 6-minute walk test, and QRS duration. HBP or BiVP was compared with RVP. Subsequently, network meta-analysis compared the three pacing options. Our protocol was registered in PROSPERO (CRD42018094132). Six studies compared BiVP and RVP (704 vs 614 patients) and four compared HBP and RVP (463 vs 568 patients). Follow-up was 6 months to 5 years. There was significantly lower mortality and HFH with HBP or BiVP as compared with RVP (odds ratio [OR], 0.66, [0.51-0.85], P = .002; OR, 0.61 [0.45-0.82], P < .001, respectively]. HBP or BiVP also showed significant increase in EF and decrease in QRS duration (mean difference [MD], 5.27 [3.86-6.69], P < .001; MD -42.2 [-51.2 to -33.3], P < .001, respectively). In network meta-analysis, HBP and BiVP were associated with significantly improved survival compared to RVP, with surface under the cumulative ranking curve (SUCRA) probability of 79.4%, 69.4%, and 1.2% for HBP, BiVP, and RVP, respectively. For HFH, SUCRA probability was 91.5%, 57.2%, and 1.3%, respectively. CONCLUSION: HBP or BiVP were the superior strategies to reduce all-cause death and HFH for advanced AVB with normal or mildly reduced EF, with no significant difference between BiVP and HBP.

Developmental and epileptic encephalopathy due to SZT2 genomic variants: Emerging features of a syndromic condition.

Seizure threshold 2 (SZT2) gene mutations have been associated with developmental and epileptic encephalopathies (DEEs). Following a literature review, we collected 22 patients and identified the main clinical features related to SZT2 variants that are epilepsy with onset within the first years of life, intellectual disability (ID), macrocephaly with dysmorphic facial features, corpus callosum (CC) shape abnormalities, and cortical migration disorders. Moreover, we identified the c.7825T>G homozygous missense variant in SZT2 in two female siblings presenting with focal seizures, mild-moderate ID, behavioral disturbances, and facial dysmorphisms. Interictal Electroencephalogram (EEG) and ictal EEG were both informative and revealed, respectively, temporal bilateral asynchronous slow and epileptiform abnormalities and a focal onset in both of them. Neuroimaging study revealed a thick and abnormally shaped CC. Seizure threshold 2 has been identified as a component of the KICSTOR complex, a newly recognized protein complex involved in the mammalian target of rapamycin (mTOR) pathway. mTOR signaling dysregulation represents common pathogenetic mechanisms that can explain the presence of both epileptogenesis and ID. Even if few cases had been reported, a new clinical phenotype is emerging, and recent hypothesis of hyperactivation of mTORC1 signaling might also open to targeted treatments, challenging an early diagnosis as of paramount importance.

A Method to Determine Human Skin Heat Capacity Using a Non-Invasive Calorimetric Sensor.

A calorimetric sensor has been designed to measure the heat flow dissipated by a 2 x 2 cm2 skin surface. In this work, a non-invasive method is proposed to determine the heat capacity and thermal conductance of the area of skin where the measurement is made. The method consists of programming a linear variation of the temperature of the sensor thermostat during its application to the skin. The sensor is modelled as a two-inputs and two-outputs system. The inputs are 1) the power dissipated by the skin and transmitted by conduction to the sensor, and 2) the power dissipated in the sensor thermostat to maintain the programmed temperature. The outputs are 1) the calorimetric signal and 2) the thermostat temperature. The proposed method consists of a sensor modelling that allows the heat capacity of the element where dissipation takes place (the skin) to be identified, and the transfer functions (TF) that link the inputs and outputs are constructed from its value. These TFs allow the determination of the heat flow dissipated by the surface of the human body as a function of the temperature of the sensor thermostat. Furthermore, as this variation in heat flow is linear, we define and determine an equivalent thermal resistance of the skin in the measured area. The method is validated with a simulation and with experimental measurements on the surface of the human body.

Prevention of Stroke in Atrial Fibrillation After Coronary Stenting.

Background and Purpose- The optimal antithrombotic strategy to balance thromboembolic and bleeding events, especially acute stroke, for patients with atrial fibrillation following coronary stenting remains a matter of debate. We conducted a network meta-analysis to identify the antithrombotic regimen associated with the lowest rate of bleeding and thromboembolic events in atrial fibrillation after coronary stenting. Methods- PubMed, Scopus, and Cochrane Central were searched for randomized controlled trials and observational studies of patients with atrial fibrillation after coronary stenting. The outcomes of interest were stroke, myocardial infarction, major adverse cardiac events, mortality, and major bleeding. A network meta-analysis was performed comparing the available antithrombotic regimens in the literature. Results- Three randomized and 15 observational studies were included, with a total of 23 478 participants. Median follow-up was 2 years. Network meta-analysis demonstrated that vitamin K antagonist plus single antiplatelet therapy or direct-acting oral anticoagulant plus single antiplatelet therapy were the most effective regimens in preventing stroke. Direct-acting oral anticoagulant regimens were associated with lower major bleeding rates than vitamin K antagonist regimens. Regimens with dual antiplatelet therapy were associated with lower rates of myocardial infarction. Vitamin K antagonist plus dual antiplatelet therapy was associated with a lower mortality and low-dose direct-acting oral anticoagulants with decreased major cardiovascular adverse events. Conclusions- Direct-acting oral anticoagulant regimens were associated with less major bleeding and major cardiovascular adverse events, but vitamin K antagonists were associated with decreased mortality and stroke. These results suggest that the decision of antithrombotic therapy in patients with atrial fibrillation after percutaneous coronary intervention needs to be individualized.

A meta-analysis of arrhythmia endpoints in randomized controlled trials of transendocardial stem cell injections for chronic ischemic heart disease.

INTRODUCTION: The electrophysiologic impact of cell-based therapy on the injured myocardium remains highly controversial. We aimed to perform a meta-analysis of studies comparing arrhythmia burden following transendocardial stem cell therapy vs placebo in patients with chronic ischemic heart disease (CIHD). METHODS AND RESULTS: PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched. No restriction of stem cell type was specified. The outcomes included sustained supraventricular or ventricular arrhythmias (VAs), sudden cardiac death (SCD), and resuscitated sudden cardiac arrest (SCA). Effect sizes were reported as odds ratio (OR) and 95% CI. Poisson regression was used to account for zero-events data. Twelve randomized trials that included 736 patients (384 in the cell therapy group and 352 in the placebo group) were analyzed. Six different cell types were used. Follow-up ranged from 6 to 12 months. There was a significant decrease in risk of SCD in the cell therapy group, (FE OR, 0.19 [0.04, 0.93]; P = .04). In subgroup analysis, there was a significantly lower risk of SCD or resuscitated SCA in the cell therapy group limited to studies that did not use skeletal myoblasts, (FE OR, 0.23 [0.06, 0.83]; P = .03). There was no significant difference in the incidence of sustained VA between groups (FE OR, 0.91 [0.47, 1.77]; P = .8), even after stratifying by cell type. There was no difference in supraventricular arrhythmias between groups. CONCLUSION: Nonskeletal myoblast transendocardial cell therapy was associated with a significantly lower risk of SCD or resuscitated SCA compared to control, with no proarrhythmic effects.

Modifying Effect of Statins on Fatal Outcomes in Chronic Kidney Disease Patients in the Systolic Blood Pressure Intervention Trial: A Post Hoc Analysis.

BACKGROUND: Management of chronic kidney disease (CKD) patients includes efforts directed toward modifying traditional cardiovascular risk factors. Such efforts include optimal management of hypertension together with the initiation of statin therapy. METHODS: In this observational study, we determine the modifying effect of statins on the relationship of systolic blood pressure (SBP) goal with mortality and other outcomes in patients with CKD participating in a clinical trial. At baseline, 2,646 CKD patients (estimated glomerular filtration rate < 60 mL/min/1.73 m2) were randomized to an intensive SBP goal < 120 mm Hg or standard SBP goal <140 mm Hg. One thousand two hundred and seventy-three were not on statin, 1,354 were on a statin, and in 19 the use of statin was unknown. The 2 primary outcomes were all-cause mortality and cardiovascular disease (CVD) mortality. RESULTS: The relationships of SBP goal with all-cause mortality (interaction p = 0.009) and cardiovascular (CV) mortality (interaction p = 0.021) were modified by the use of statin after adjusting for age, gender, race, CVD history, smoking, aspirin use, and blood pressure at baseline. In the statin group, targeting SBP to < 120 mm Hg compared to SBP < 140 mm Hg significantly reduced the risk of all-cause mortality (adjusted hazard ratio [aHR] 0.44 [0.28-0.71]; event rates 1.16 vs. 2.5 per 100 patient-years) and CV mortality (aHR 0.29 [0.12-0.74]; event rates 0.28 vs. 0.92 per 100 patient-years) after a median follow-up of 3.26 years. In the non-statin group, the risk of all-cause mortality (aHR 1.07 [0.69-1.66]; event rates 2.01 vs. 1.94 per 100 patient-years) and CV mortality (aHR 1.42 [0.56-3.59]; event rates 0.52 vs. 0.41 per 100 patient-years) were not significantly different in both SBP goal arms. CONCLUSION: The combination of statin therapy and intensive SBP management leads to improved survival in hypertensive patients with CKD.

Measurement of human body surface heat flux using a calorimetric sensor.

We have developed a calorimetric sensor that can perform local measurements of the heat flux transmitted by conduction between a human body and thermostat located inside the sensor. The sensor has a detection area of 2 × 2 cm2 and, in its current configuration, facilitates measurement with a resolution of 10 mW. In this paper, measurements of two healthy male subjects of different ages (24 and 60 years) are presented. We study the variation in the power dissipated by the human body surface as a function of time for a thermostat temperature of 28 °C. We also study the same power with thermostat temperatures varying from 24° to 36°C. Measurements are performed on three different surface areas of the human body: the sternum, abdomen, and hand. The ambient room temperature during all measurements was in the range of 22-24 °C, and the subjects were seated and resting. The results show that the heat flux in the trunk is much more stable than that in the hand and that the heat flux in the sternum is greater than that in other areas. Additionally, this flux is higher in the younger subject (42 mW/cm2) than in the older subject (35 mW/cm2). We also defined a thermal parameter that represents the thermal resistance between the sensor thermostat and the skin. The mean value of this parameter varies between 51 and 71 K/W depending on the subject and measurement area.

Computed tomography is a feasible method for quantifying bone density in Macaca mulatta.

Osteopathologies are a result of advanced age and decreased bone density and represent a global health problem. It is therefore important to generate models for longitudinal studies of the pathophysiology in order to improve early diagnosis and develop preventive therapies. For this kind of research, the use of computed tomography (CT) to evaluate bone health offers advantages over other techniques since it provides more complete information. The aim of this prospective, pilot study was to obtain measurements of the left femur from a population in captivity of 32 rhesus monkeys (Macaca mulatta) in order to standardize the model for future research. Healthy subjects from 5 to 28 years old were chosen. Three groups with different ages were formed as follows: (1) 5-9 years, (2) 10-19 years, and (3) 20-28 years. Semi-automatic segmentation by threshold defined the regions of interest, which were subdivided in the range of 300-700 Hounsfield units (HU) for trabecular bone and >700 HU for cortical bone. Then, the proportional ratios of the volumes of trabecular bone and cortical bone were obtained. Significant differences (analysis of variance test) in the averages of Hounsfield units, cortical, and trabecular bone proportions from each age group proved that a decrease in bone density begins at approximately 20 years of age. The values presented here, as well as the method to obtain them from CT scans, can be used as a baseline in a primate model for long-term research in bone pathology diagnosis and treatment.

Mathematical Model for Localised and Surface Heat Flux of the Human Body Obtained from Measurements Performed with a Calorimetry Minisensor.

The accuracy of the direct and local measurements of the heat power dissipated by the surface of the human body, using a calorimetry minisensor, is directly related to the calibration rigor of the sensor and the correct interpretation of the experimental results. For this, it is necessary to know the characteristics of the body's local heat dissipation. When the sensor is placed on the surface of the human body, the body reacts until a steady state is reached. We propose a mathematical model that represents the rate of heat flow at a given location on the surface of a human body by the sum of a series of exponentials: W(t) = A0 + ∑Aiexp(-t/τi). In this way, transient and steady states of heat dissipation can be interpreted. This hypothesis has been tested by simulating the operation of the sensor. At the steady state, the power detected in the measurement area (4 cm²) varies depending on the sensor's thermostat temperature, as well as the physical state of the subject. For instance, for a thermostat temperature of 24 °C, this power can vary between 100-250 mW in a healthy adult. In the transient state, two exponentials are sufficient to represent this dissipation, with 3 and 70 s being the mean values of its time constants.

Calorimetry Minisensor for the Localised Measurement of Surface Heat Dissipated from the Human Body.

We have developed a calorimetry sensor that can perform a local measurement of the surface heat dissipated from the human body. The operating principle is based on the law of conductive heat transfer: heat dissipated by the human body passes across a thermopile located between the individual and a thermostat. Body heat power is calculated from the signals measured by the thermopile and the amount of power dissipated across the thermostat in order to maintain a constant temperature. The first prototype we built had a detection area measuring 6 × 6 cm², while the second prototype, which is described herein, had a 2 × 2 cm² detection area. This new design offers three advantages over the initial one: (1) greater resolution and three times greater thermal sensitivity; (2) a twice as fast response; and (3) it can take measurements from smaller areas of the body. The sensor has a 5 mW resolution, but the uncertainty is greater, up to 15 mW, due to the measurement and calculation procedure. The order of magnitude of measurements made in healthy subjects ranged from 60 to 300 mW at a thermostat temperature of 28 °C and an ambient room temperature of 21 °C. The values measured by the sensor depend on the ambient temperature and the thermostat's temperature, while the power dissipated depends on the individual's metabolism and any physical and/or emotional activity.

Ectopic ACTH secretion (EAS) associated to a well-differentiated peritoneal mesothelioma: case report.

BACKGROUND: The association between mesotheliomas and ectopic ACTH secretion has been rarely reported; we present the first case of ectopic ACTH secretion (EAS) associated with a well-differentiated peritoneal mesothelioma in whom the high dose dexamethasone suppression test (HDDST) results and plasmatic ACTH levels were similar to those found in Cushing's disease (CD). CASE PRESENTATION: A 43-year-old hispanic woman with a 20 year history of treatment resistant diabetes mellitus and arterial hypertension. She had a full moon face, a buffalo hump, increased volume in both supraclavicular regions, purple striae in her arms and abdomen, truncal obesity, polymenorrhea and umbilical hernia. A cortisol suppression test with low dose dexamethasone (LDDST) with a result of 16.6 µg/dL and ACTH plasma levels were measured at 32.6 pg/mL. The high dose dexamethasone test suppression percentage was 84.8% and magnetic resonance imaging (MRI) showed no evidence of pituitary alterations, computed tomography (CT) showed images suggestive of uterine fibroid and an intra-abdominal tumor that correlated with an umbilical hernia, which reinforcement after contrast. Surgery was performed, finding uterine fibroids and paracolic tumor implants as well as on the omentum, bladder, bowel, ovaries and appendix. Pathology reported a well-differentiated peritoneal mesothelioma with positive immunohistochemistry for ACTH. CONCLUSIONS: Although most cases of ectopic secretion of ACTH derive from rapidly-developing lung tumors, with very high plasma ACTH levels and cortisol suppression percentages with high doses of dexamethasone under 60%, there is a small percentage of slow-developing, chronic tumors that are biochemically undistinguishable from Cushing's disease. Following the expert recommendations regarding imaging techniques it is possible to identify the associated tumor in most cases.