The metabolic cost of subcutaneous and abdominal rewarming in king penguins after long-term immersion in cold water.

Marine endotherms in the polar regions face a formidable thermal challenge when swimming in cold water. Hence, they use morphological (fat, blubber) adjustment and peripheral vasoconstriction to reduce demands for heat production in water. The animals then regain normothermia when resting ashore. In the king penguin (Aptenodytes patagonicus) metabolic rate is lower in fed than in fasted individuals during subsequent rewarming on land. This has been suggested to be a consequence of diversion of blood flow to the splanchnic region in fed birds, which reduces peripheral temperatures. However, peripheral temperatures during recovery have never been investigated in birds with different nutritional status. The aim of this study was, therefore, to measure subcutaneous and abdominal temperatures during the rewarming phase on land in fasted and fed king penguins, and investigate to which extent any different rewarming were reflected in recovery metabolic rate (MRR) after long term immersion in cold water. We hypothesized that fed individuals would have a slower increase of subcutaneous temperatures compared to fasted penguins, and a correspondingly lower MRR. Subcutaneous tissues reached normothermia after 24.15 (back) and 21.36 min (flank), which was twice as fast as in the abdomen (46.82 min). However, recovery time was not affected by nutritional condition. MRR during global rewarming (4.56 ± 0.42 W kg-1) was twice as high as resting metabolic rate (RMR; 2.16 ± 0.59 W kg-1). However, MRR was not dependent on feeding status and was significantly elevated above RMR only until subcutaneous temperature had recovered. Contrary to our prediction, fed individuals did not reduce the subcutaneous circulation compared to fasted penguins and did not show any changes in MRR during subsequent recovery. It seems likely that lower metabolic rate in fed king penguins on land reported in other studies might not have been caused primarily by increased circulation to the visceral organs.

Browning formation markers of subcutaneous adipose tissue in relation to resting energy expenditure, physical activity and diet in humans.

Background Regular exercise and diet may contribute to white adipose tissue (WAT) conversion into a brown adipose-like phenotype that may increase resting energy expenditure (REE), leading to weight loss. We examined the relationship between REE, physical activity (PA) participation and diet with browning formation markers of subcutaneous WAT in healthy men. Materials and methods We assessed REE, diet and body composition of 32 healthy men [age (years): 36.06 ± 7.36, body mass index (BMI): 27.06 ± 4.62 (kg/m2)]. Participants also underwent measurements of PA [metabolic equivalent (MET)-min/week] using the International Physical Activity Questionnaire (IPAQ), while they undertook a subcutaneous fat biopsy from the abdominal region to assess the mRNA expressions of uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), peroxisome proliferator-activated receptor alpha (PPARα) and peroxisome proliferator-activated receptor gamma (PPARγ). Results We found no associations between the UCP1, PGC-1α, PPARα and PPARγ mRNAs with REE, PA levels and diet (p > 0.05). However, the PGC-1α, PPARα and PPARγ mRNAs were more expressed in individuals displaying moderate rather than low PA levels (p < 0.05). Furthermore, PGC-1α, PPARα and PPARγ mRNAs were negatively correlated with fat mass percentage (p < 0.05). PGC-1α and PPARα mRNAs were also negatively correlated with BMI, while PGC-1α mRNA was inversely associated with waist-to-hip ratio (p < 0.05). Conclusion REE, PA levels and diet are not associated with browning formation indices of subcutaneous adipose tissue in healthy adult men.

Reproducibility analysis on shear wave elastography (SWE)-based quantitative assessment for skin elasticity.

Shear Wave Elastography (SWE) is an objective and non-invasive method widely used to quantify the tissue solidity. However, there are concerns about the accuracy of the skin SWE results due to the low signal-to-noise ratio (SNR) caused by subcutaneous fat, muscle and bone. This article analyzed the reproducibility of the result for skin SWE and therefore evaluated the availability of SME for skin elasticity involved diseases. Thirty volunteers (mean age: 37 ±â€Š12 years) were selected. SWE were taken on the skin of abdomen and the middle tibia in order to assess the impact of fat, muscle and bone on SWE results. Skin in the area of anterior and lateral tibia marked with seven parallel lines, and each line indicated an identical thickness of the subcutaneous fat from 1-7 mm. Intra-class correlation coefficients (ICC) were used to evaluate the intra-observer and inter-observer reproducibility. The solidity of abdominal skin showed soft and small individual differences (12.4 ±â€Š2.7 kPa), whereas high shear moduli (25-48 kPa) were observed in the skin above tibia and tibialis anterior muscle. When the subcutaneous fat was thicker than 3 mm (≥3), we obtained excellent intra-observer reproducibility (ICC range 0.78-0.98) and inter-observer reproducibility (ICC range 0.75-0.98). The thickness of subcutaneous fat could affect the reproducibility of skin SWE. The further study on skin SWE standardization should be taken.

Design and assessment of novel artificial anal sphincter with adaptive transcutaneous energy transfer system.

This paper presents the in vitro assessment of a novel elastic scaling artificial anal sphincter system (ES-AASS) with an adaptive transcutaneous energy transfer system (TETS) for treatment of severe faecal incontinence (FI). The proposed adaptive TETS has a phase control, which can maintain the output voltage at ∼7 V across the full range of the coupling coefficient variation (from 0.09-0.31) during the whole process of charging with a phase shift of 177.5° to 79.1°. A maximum surface temperature of 42.2 °C was measured above the secondary coil during an energy transmission of 3.5 W in air. The specific absorption rate (SAR) and current density analysis of the biological three-layers structure, including the skin, fat and muscle) surrounding the coil pair were analysed and the results of simulation analysis showed that the value of SAR and current density were very small at any given transmission condition compared with the basic restrictions of the International Commission on Non-Ionizing Radiation Protection (ICNIRP). In conclusion, in vitro experimental results showed that the ES-AASS can control simulated faecal behaviour effectively and the performance of TETS was validated.

Subjective clinical lipoatrophy assessment correlates with DEXA-measured limb fat.

OBJECTIVES: Although physician- and patient-rated diagnoses of lipoatrophy are currently used as a basis for inclusion into clinical trials, few studies have compared physician- or patient-rated lipoatrophy severity with objective measures. We aim to assess the validity of physician- and patient-rated diagnoses of lipoatrophy by evaluating the correlation between clinical assessments of lipoatrophy and objective fat indices. METHODS: This cross-sectional study evaluated the association between clinical lipoatrophy scores and DEXA-measured limb fat (n = 154) and subcutaneous fat mitochondrial DNA (mtDNA) levels (n = 80) in HIV+ individuals. RESULTS: There was a significant negative correlation between DEXA-measured limb fat and lipoatrophy scores generated by either the patients (r = -0.27, p = .008) or the physician (r = -0.48, p < .0001). Also, a significant positive correlation was found between the patient-generated lipoatrophy score and the physician score (r = 0.68, p < .0001). However, there was no correlation between fat mtDNA levels and DEXA-measured limb fat (r = -0.09, p = .42) or between physician- or patient-generated lipoatrophy scores (r = -0.09, p = .43, and r = 0.04, p = .71, respectively). CONCLUSION: These results suggest that physician- and patient-rated lipoatrophy scores may be useful surrogates for more expensive measures of lipoatrophy, which could be reserved for research studies.