基于MRI评估的胰腺脂肪沉积及腹部脂肪分布与原发性高血压的相关性研究

目的探讨基于MRI评估的胰腺脂肪沉积、内脏脂肪和皮下脂肪与原发性高血压的相关性。材料与方法纳入54例高血压患者和108例对照者。应用半自动分割对全胰腺进行分割,并测量全胰腺脂肪分数值。应用Image J软件测量内脏脂肪(visceral adipose tissue,VAT)和皮下脂肪(subcutaneous adipose tissue,SAT)面积,并记录VAT和SAT脂肪分数值(fat fraction,FF),计算内脏/皮下脂肪组织的面积比(V/S)。数据由SPSS进行统计学分析。P<0.05被认为差异具有统计学意义。结果高血压患者全胰腺脂肪分数值、VAT和SAT面积、V/S、VAT和SAT脂肪分数值均高于对照者。全胰腺脂肪分数值对高血压的诊断价值最高(AUC=0.816)。全胰腺脂肪分数的阈值为10.15%,对高血压诊断的敏感度为75.9%,特异度为81.5%。全胰腺FF与VAT面积和脂肪分数值呈中等相关性(r=0.541、0.561);与SAT面积、脂肪分数值和V/S的相关性较低(r=0.280、0.324、0.266)。结论高血压者与全胰腺脂肪分数、VAT和SAT增多有关。全胰腺脂肪分数与VAT和SAT的增加相关。     

MRI脂质定量评估Irisin干预后小鼠肩胛间棕色脂肪激活

目的 探讨MR化学位移选择成像活体定量评估Irisin干预后小鼠肩胛间棕色脂肪组织(iBAT)脂质含量与其活性的相关性。方法 以12只小鼠构建高脂饮食(HFD)诱导肥胖模型(HFD组),随机将其分为磷酸盐缓冲液(PBS)亚组(HFD_PBS亚组)、Irisin干预2周亚组(HFD_Irisin2w亚组)及干预4周亚组(HFD_Irisin4w亚组),每亚组4只；另以正常饮食(CD)饲养4只小鼠(CD组)。对各组对应注射PBS或Irisin溶液予以干预4周后行7.0T Micro MR化学位移成像，测量小鼠iBAT脂质含量_MRI;以HE染色测量iBAT细胞内脂滴面积和脂质含量_HE,以免疫组织化学法检测iBAT解耦联蛋白1(UCP-1)表达水平。比较各指标组(亚组)间差异，评价MR化学位移成像定量小鼠iBAT脂质含量_MRI与病理学检测结果的相关性。结果 HFD_PBS亚组小鼠iBAT脂质含量_MRI、脂滴面积及脂质含量     

Effects of local alpha2-adrenergic receptor blockade on adipose tissue lipolysis during prolonged systemic adrenaline infusion in normal man

During prolonged adrenaline infusion, lipolysis peaks within 30 min and thereafter tends to decline, and we hypothesized that the stimulation of local adipose tissue alpha2-adrenergic receptors accounts for this decline. The lipolytic effect of a prolonged intravenous adrenaline infusion combined with local infusion of the alpha2-blocker phentolamine in superficial and deep abdominal subcutaneous adipose tissue and in preperitoneal adipose tissue was studied in seven healthy subjects. The interstitial glycerol concentration in the three adipose tissue depots was measured by the microdialysis method. Regional adipose tissue blood flow was measured by the (133)Xe clearance technique. Regional glycerol output (lipolytic rate) was calculated from these measurements and simultaneous measurements of arterial glycerol concentrations. Adrenaline infusion increased lipolysis in all three depots (data previously published). Phentolamine infusion did not augment lipolysis in the subcutaneous depots while it increased the lipolytic rate in the preperitoneal depot. It is concluded that alpha2-adrenergic receptors do not have a significant effect on subcutaneous adipose tissue lipolysis during high circulating adrenaline concentrations, and the decrease in lipolysis in subcutaneous adipose tissue under prolonged adrenaline stimulation is thus not attributed to alpha2-adrenergic receptor inhibition of lipolysis. However, in the preperitoneal adipose tissue depot, alpha2-adrenergic receptor tone plays a role for the lipolytic rate obtained during prolonged adrenaline stimulation.     

基于MRI影像组学对评估术前直肠癌周边纤维脂肪组织浸润的应用价值

目的  评估基于MRI影像组学模型对术前直肠癌周边纤维脂肪组织浸润的应用价值。方法  回顾性分析2019年12月~ 2022年3月于铜陵市人民医院术后经病理证实直肠癌75例患者术前MRI图像资料,根据病理结果分为纤维脂肪组织浸润组（n=33）及纤维脂肪组织未浸润组（n=42）。基于T2WI及动脉期对比增强T1WI（CE-T1WI）提取影像组学特征,将数据按照7:3的比例分为训练组（n=54）与验证组（n=21）,采用最大相关最小冗余和最小绝对收缩和选择算子回归的方法对训练集数据进行特征降维,并将特征降维后作为特征向量,筛选出最佳的影像组学特征,构建出T2WI模型、CE-T1WI模型及T2WI+CE-T1WI模型3种影像组学模型,根据ROC曲线确定其中最优模型;根据肿瘤上下径、肿瘤最厚径、CE-T1WI相对信号强度比值（R_CE-T1WI）、T2WI相对信号强度比值（R_T2）、DWI相对信号强度比值（R_DWI）及ADC值多因素Logistic回归分析构建出联合模型;评估最优模型与联合模型二者效能及临床效益。结果  基于T2WI和CE-T1W1各提取851个影像组学特征,最终分别获得10个和14个最佳特征,用于构建T2WI+CE-T1WI模型。基于T2WI模型、CE-T1W1模型及T2WI+CE-T1WI模型在训练组中对判定直肠癌周边纤维脂肪组织浸润的AUC分别为0.87（95% CI：0.75~0.95）、0.82（95% CI：0.70~0.91）和0.84（95% CI：0.71~0.92）,在验证组中分别为0.76（95% CI：0.53~0.92）、0.73（95% CI：0.50~0.90）和0.76（95% CI：0.52~0.92）。采用联合模型在训练组中对直肠癌纤维脂肪组织浸润的AUC为0.91（95% CI：0.80~0.97）,在验证组中AUC为0.80（95% CII：0.57~0.94）。决策曲线分析提示,阈值取0~1时,联合模型的净收益高于T2WI模型。结论  基于MRI影像组学的联合模型对评估术前直肠癌周边纤维脂肪组织浸润的效能较高。     

Effects of weight loss on visceral and abdominal subcutaneous adipose tissue blood-flow and insulin-mediated glucose uptake in healthy obese subjects

Objective. Rapid weight loss with very-low-calorie diet (VLCD) is known to improve insulin sensitivity and decrease adipose tissue masses. The aim was to investigate the effects of VLCD on adipose tissue regional glucose uptake (rGU) and perfusion and their association with adipokines.

Research design and methods. Sixteen healthy obese (body mass index 33±1.1 kg/m²) subjects underwent VLCD for 6 weeks. RGU and perfusion were measured using [¹⁸F]-fluoro-deoxy-glucose, [¹⁵O]H₂O and positron emission tomography.

Results. Blood-flow and rGU expressed per gram of adipose tissue were higher in visceral fat compared to abdominal subcutaneous fat (P<0.01 for both). Dieting decreased weight by 11±0.9 kg (P<0.0001). Visceral adipose fat decreased by 25% (P<0.001) and abdominal subcutaneous fat by 16% (P<0.001). Whole body insulin sensitivity increased by 33% (P<0.01). Perfusion of both fat depots decreased (P<0.001), while rGU remained unchanged. Among the adipokines, leptin and interleukin-6 levels seemed to be associated with abdominal subcutaneous and intra-abdominal adipose tissue insulin resistance but not with adipose tissue perfusion.

Conclusions. Abdominal adipose tissue perfusion and rGU are not related in obesity. Rapid weight loss decreases perfusion through adipose tissue depots but has no influence on rGU demonstrating the ‘sink’ role of adipose tissue.     

The role of pericardial adipose tissue in the heart of obese minipigs

Background

Pericardial adipose tissue (PAT) volume is highly associated with the presence and severity of cardiometabolic diseases, but the underlying mechanism is unknown. We previously demonstrated that a high‐fat diet (HFD) induced metabolic dysregulation, cardiac fibrosis and accumulation of more PAT in minipigs. This study used our obese minipig model to investigate the characteristics of PAT and omental visceral fat (VAT) induced by a HFD, and the potential link between PAT and HFD‐related myocardial fibrosis.

Materials and methods

Five‐month‐old Lee‐Sung minipigs were made obese by feeding a HFD for 6 months.

Results

The HFD induced dyslipidemia, cardiac fibrosis and more fat accumulation in the visceral and pericardial depots. The HFD changes the fatty acid composition in the adipose tissue by decreasing the portion of linoleic acid in the VAT and PAT. No arachidonic acid was detected in the VAT and PAT of control pigs, whereas it existed in the same tissues of obese pigs fed the HFD. Compared with the control pigs, elevated levels of malondialdehyde and TNFα were exhibited in the plasma and PAT of obese pigs. HFD induced greater size of adipocytes in VAT and PAT. Higher levels of GH, leptin, OPG, PDGF, resistin, SAA and TGFβ were observed in obese pig PAT compared to VAT.

Conclusion

This study demonstrated the similarities and dissimilarities between PAT and VAT under HFD stimulus. In addition, this study suggested that alteration in PAT contributed to the myocardial damage.     

Acute exercise affects dual-energy X-ray absorptiometry body composition estimates but not standardised ultrasound measurements of subcutaneous adipose tissue

Ultrasound has been demonstrated to be a highly accurate and reliable tool for measuring subcutaneous adipose tissue thickness and is robust against changes in hydration status or acute food or fluid intake. However, the effect of prior acute exercise is unexamined. This study examined the impact of an acute endurance exercise and resistance exercise session on standardised brightness-mode ultrasound measurements of subcutaneous adipose tissue thickness compared to skinfolds and dual-energy X-ray absorptiometry body composition estimates. In a randomised cross-over design, 30 active adults (24.2 ± 4.9 years) undertook physique assessment via standardised brightness-mode ultrasound, skinfolds and dual-energy X-ray absorptiometry before, immediately and 45 min after an acute endurance or resistance exercise session. The mean sum of eight subcutaneous adipose tissue thickness measured via standardised brightness-mode ultrasound increased (0.6 mm, p = 0.04) immediately postendurance exercise but was not meaningful when evaluated against the technical error of measurement of the investigator. A significant (p = 0.01) but not meaningful decrease in the sum of eight skinfolds occurred immediately (−1.1 ± 0.4 mm) and 45 min (−1.3 ± 0.4 mm) postresistance exercise. Comparatively, endurance exercise elicited a meaningful decrease of total mass (460 ± 30 g) and trunk lean mass (680 ± 90 g) dual-energy X-ray absorptiometry estimates. Findings from this study indicate standardised client presentation may be unnecessary when employing either standardised brightness-mode ultrasound or skinfolds for body composition assessment unlike dual-energy X-ray absorptiometry.     

Non-invasive cooling wear as an effective means of reducing subcutaneous adipose tissue mass: an in-vivo study

ObjectiveThe increasing prevalence of obesity is a major health problem worldwide. Several non-surgical treatments are now available that reduce body and subcutaneous fat mass. We aimed to determine the efficacy of mild cold for body mass reduction.MethodsNovel cooling wear, which induces mild cooling via evaporation, was worn by 29 women with overweight for 4 weeks. Specifically, the participants wore a cooling waist belt and chaps for 1 hour per day. Non-invasive lipometry was used to determine their subcutaneous adipose tissue thicknesses, and the total weight loss, abdominal circumference, and body mass index (BMI) of the participants were measured.ResultsThe participants achieved a significant total weight loss of 0.7 kg (0.9%), and significant reductions in BMI (0.2 kg/m²) and abdominal circumference (1.9 cm, 1.7%). Furthermore, there was a trend towards a reduction in abdominal subcutaneous fat thickness and a significant reduction in thickness of the anterior thigh was noted. A questionnaire-based evaluation indicated high usability and comfort of the cooling wear.ConclusionThere is a high and growing demand for non-invasive treatment strategies for obesity. Cooling wear represents a novel and promising approach that may be of particular use for individuals who do not require bariatric surgery.     

Comparison of infrapatellar and subcutaneous adipose tissue stromal vascular fraction and stromal/stem cells in osteoarthritic subjects

Since inflammatory mechanisms have been postulated to link obesity to osteoarthritis, the current study evaluated the ratio of immune cells to multipotent stromal cells within the infrapatellar fat pad (IPFP) and subcutaneous adipose tissue (SQ) of the knee; each depot has potential as a source of regenerative cells. The immunophenotypes of stromal vascular fraction (SVF) and adipose‐derived stem cells (ASCs) of the IPFP and SQ were determined in tissues from osteoarthritic subjects (n = 7) undergoing total knee replacement. Based on a subset of surface antigens, the immunophenotype of ASCs from SQ of OA subjects was not significantly different from that of relatively healthy and leaner subjects undergoing elective liposuction surgery. Flow‐cytometry comparison of SVF cell populations in the IPFP of OA subjects resembled those within the subject's own matched SQ, with the exception of the endothelial marker CD31⁺, which was significantly greater in cells from SQ. In the OA subjects, lower numbers of capillary‐like structures and higher numbers of stromal and alkaline phosphatase colony‐forming units in the IPFP vs SQ were consistent with this finding; however, ASCs from both depots in OA subjects exhibited comparable adipogenic and osteogenic differentiation potential. Thus, the IPFP contains an ASC and immune cell population similar to that of donor‐matched SQ, making it an alternative ASC source for tissue regeneration. Further studies will be needed to determine whether IPFP immune cell infiltrates play an aetiological role in osteoarthritis equivalent to that shown in diabetes associated with obesity. Copyright © 2012 John Wiley & Sons, Ltd.     

Effects of pravastatin and rosuvastatin on the generation of adiponectin in the visceral adipose tissue in patients with coronary artery disease

Pravastatin increases the plasma adiponectin level. We examined whether this is a statins’ class effect or specific to pravastatin. Of 50 patients undergoing cardiac surgery for coronary artery disease (CAD, n = 36) and valvular heart disease (VHD, n = 14), 23 with CAD and serum LDL‐cholesterol level >100 mg/dL were randomized to pravastatin at 10 mg/day (PRAVA, n = 12) or rosuvastatin at 2.5 mg/day (ROSUVA, n = 11) for 2 months, and the other 13 with CAD and LDL‐cholesterol ≤100 mg/dL were not treated with statin (Non‐statin, n = 13). Patients with VHD did not have CAD and were not treated with statin. Blood was sampled at baseline and surgery. Visceral (VIS) and subcutaneous (SC) adipose tissues were harvested during surgery. At baseline, the plasma adiponectin level was low in patients with CAD compared with that of patients with VHD. At surgery, adiponectin level in PRAVA was increased to the level in VHD, whereas those in ROSUVA and Non‐statin were unchanged. VIS contents and gene expressions of adiponectin in PRAVA and VHD were similar to each other and were both higher than those in Non‐statin and ROSUVA. SC content and gene expression of adiponectin were similar among 4 groups. Protein carbonyl (PC) level, an indicator of oxidative stress, in VIS was lower in PRAVA and VHD than in ROSUVA and Non‐statin. There was a negative correlation between the plasma adiponectin and VIS PC levels (r = ?0.41, P < 0.05). Thus, pravastatin increases adiponectin generation, whereas rosuvastatin does not.     

Primary peripheral T-cell lymphoma in subcutaneous tissue: sonographic findings

We describe the sonographic findings in a case of Lennert's lymphoma, a rare type of peripheral T-cell lymphoma, involving the subcutaneous tissues of the arm. The sonographic appearance was thought to be more helpful than MRI to establish the diagnosis.     

内脏脂肪组织与急性胰腺炎严重程度的相关性分析

目的：研究内脏脂肪组织（ visceral adipose tissue , VAT）和急性胰腺炎（ AP）的严重程度之间的关系,探索VAT在预测急性胰腺炎严重程度中的价值。方法回顾性收集2010－01～2013－12期间我院收治的257例急性胰腺炎病例,通过计算断层扫描图像来衡量VAT面积;其他分析因素包括年龄、性别、体质量指数（body mass index, BMI）、APACHEⅡ评分、Ranson’s评分、住院时间和死亡事件。结果56例（21.79％）患者被确诊为中度和重症急性胰腺炎。轻型胰腺炎和中度、重症急性胰腺炎内脏脂肪组织百分比（ VAT％）差异存在统计学意义（ P＝0.013）。中度和重症急性胰腺炎患者VAT％增高,VAT％与BMI没有相关性,但VAT％预测急性胰腺炎严重程度的能力优于BMI。结论 VAT增加与急性胰腺炎的严重程度密切相关。 VAT相对于BMI有着独特的预后价值,建议在急性胰腺炎早期评估中纳入VAT指标。     

Determination of adipose tissue blood flow with local 133Xe clearance. Evaluation of a new labelling technique

Adipose tissue blood flow was measured in six healthy, non-obese subjects with the xenon wash-out technique after labelling of the tissue by either injection of 133Xe dissolved in isotonic sodium chloride (water depot) or injection of 133Xe in gas form (gas depot). The wash-out rates were registered from four depots simultaneously. Two depots were placed above the umbilicus, and two depots were placed below the umbilicus in the abdominal, subcutaneous adipose tissue. A water depot and a gas depot were placed in the two positions, respectively. It was not possible to demonstrate any difference between the wash-out rates registered from the two depot types, and it was also not possible to demonstrate any difference between the changes in wash-out rates induced by an oral glucose load. Similarly, the tissue distribution of the water and the gas depots appeared to be similar as registered by a gamma camera. It is concluded that that the two tissue labelling modes give identical results. However, there are significant regional differences in the wash-out rates of xenon from subcutaneous, abdominal adipose tissue, the wash-out rates from infraumbilical depots being about 20% lower than from the supraumbilical depots.     

Pathogenic potential of adipose tissue and metabolic consequences of adipocyte hypertrophy and increased visceral adiposity

When caloric intake exceeds caloric expenditure, the positive caloric balance and storage of energy in adipose tissue often causes adipocyte hypertrophy and visceral adipose tissue accumulation. These pathogenic anatomic abnormalities may incite metabolic and immune responses that promote Type 2 diabetes mellitus, hypertension and dyslipidemia. These are the most common metabolic diseases managed by clinicians and are all major cardiovascular disease risk factors. ‘Disease’ is traditionally characterized as anatomic and physiologic abnormalities of an organ or organ system that contributes to adverse health consequences. Using this definition, pathogenic adipose tissue is no less a disease than diseases of other body organs. This review describes the consequences of pathogenic fat cell hypertrophy and visceral adiposity, emphasizing the mechanistic contributions of genetic and environmental predispositions, adipogenesis, fat storage, free fatty acid metabolism, adipocyte factors and inflammation. Appreciating the full pathogenic potential of adipose tissue requires an integrated perspective, recognizing the importance of ‘cross-talk’ and interactions between adipose tissue and other body systems. Thus, the adverse metabolic consequences that accompany fat cell hypertrophy and visceral adiposity are best viewed as a pathologic partnership between the pathogenic potential adipose tissue and the inherited or acquired limitations and/or impairments of other body organs. A better understanding of the physiological and pathological interplay of pathogenic adipose tissue with other organs and organ systems may assist in developing better strategies in treating metabolic disease and reducing cardiovascular disease risk.     

中国人内脏脂肪指数及内脏脂肪面积与糖尿病肾病的相关性及其预警价值

目的 探讨中国人内脏脂肪指数(Chinese visceral adipose index, CVAI)及内脏脂肪面积(visceral fat area,VFA)与糖尿病肾病(diabetic nephropathy,DN)的关系及病情预警价值。方法 选取2020年10月至2021年10月于甘肃省人民医院内分泌科住院治疗的2型糖尿病(type 2 diabetes mellitus, T2DM)患者240例,收集患者临床资料(一般资料、体格检查、生化指标等)。根据有无DN分为DN组(n=114)、非DN组(n=126)。将CVAI及VFA与尿白蛋白排泄率(urinary albumin excretion rate,UAER)、尿白蛋白/肌酐比值(urine albumin creatine ratio, UACR)、估算肾小球滤过率(estimated glomerular filtration rate,eGFR)作Spearman相关性分析。采用多因素logistic逐步回归分析法筛选T2DM患者发生DN的独立危险因素,并建立多因素logistic回归模型,通过受试者工作特征(...     

定量非对称回波最小二乘估算法迭代水脂分离序列MRI研究及应用进展

定量非对称回波最小二乘估算法迭代水脂分离序列（IDEAL-IQ） MRI的信噪比（SNR）较高,可有效定量评估体内脂肪和铁含量及分布,近年来临床应用范围逐渐扩大。本文就IDEAL-IQ MRI研究及应用进展进行综述。     

Triglyceride synthesis in human subcutaneous adipose tissue cells of different size

Abstract Human adipose tissue fat cells, liberated by eollagenase treatment, were separated into different sizes with a technique utilizing the differences in flotation rates of large and small fat cells in a physiological medium. — Incubation of fat cells after treatment with collagenase caused a pronounced breakage of fat cells. Therefore only incorporation of radioactivity from l-¹⁴C-glucose into triglyceride but not into carbon dioxide could be measured in separated fat cells. When collagenase-liberated fat cells were incubated with radioactive glucose, radioactivity in the triglycerides increased with fat cell diameter in the remaining intact fat cells. When intact adipose tissue was incubated with radioactive glucose and then subjected to collagenase treatment, followed by separation of fat cells into different fat cell size classes, the same phenomenon was observed, namely a significant positive correlation between fat cell size and incorporation of radioactivity from glucose into triglycerides in adipose tissue with a wide range of fat cell diameters. Insulin response was small and varying. The dependence of triglyceride synthesis on fat cell size varied in different adipose tissue samples.     

Comparison of two methods to assess the tissue/blood partition coefficient for xenon in subcutaneous adipose tissue in man

Summary. A new method to calculate the tissue/blood partition coefficient (Λ) for xenon in studies on the subcutaneous adipose tissue blood flow was compared with a previously reported method based on local skinfold thickness (Λ_LSt). The former method included needle biopsies from the abdominal and femoral subcutaneous adipose tissue, and the mean fat cell diameter was measured (Λ_ECT)- The extracellular tissue fraction in subcutaneous tissue was then estimated from a diagram. The tissue lipid content was approximated to equal the relative intracellular volume and Ostwald's solubility coefficients for ¹³³Xe, based on the distribution of xenon in lipid, albumin and 0.9% saline were applied. Estimated Λ-values based on needle biopsies from the abdominal site were: 8.6±0.1 versus 9.9±0.4 ml g^-1 (meanæ) (P<0.05) and from the femoral site: 9.1±0.1 versus 9.6±0.2 in lean (n=10) and obese subjects (n=10), respectively. The corresponding Λ-values obtained from skinfold measurements were: 6.2±0.5 versus 11.0±0.4 (P<0.001) and 6.9±03 versus 11.4±0.4 (P<0.001) in lean and obese subjects, respectively. Pooled Λ_LsT-values correlated positively with estimated adipose tissue blood flow (ATBF) (r: 0.34, P<0.05, n=40) whereas no such correlation was found for Λ_ECT-values. In conclusion, a new method is presented which may allow an accurate determination of, and which may lead to reliable data on, subcutaneous ATBF in both lean and obese subjects. Comparative studies indicate that the widely used Λ-value of 10.0 in subcutaneous adipose tissue may be used as a rough estimate for subcutaneous blood flow studies in these patient groups.     

人工智能分割心外膜脂肪组织研究进展

心外膜脂肪(EAT)属内脏脂肪组织，具有复杂的生理及病理特性，对于多种心血管相关疾病的发生、发展及预后等具有重要影响。随着人工智能(AI)的快速发展，基于AI分割EAT并用于诊疗心血管疾病等已成为研究热点。本文就AI分割EAT研究进展进行综述。     

囊性软组织病变的MRI诊断

目的：了解MRI对囊性软组织病变的诊断能力。方法：分析35个病变的部位，信号等MR征象。结果：皮质腺囊肿等位于皮肤和皮下，神经纤维瘤等位于肌间隙。腱鞘囊肿和滑膜肉瘤等位于关节旁，脂肪肉瘤等位于肌肉内，脓肿，转移瘤和血肿有灶周水肿，前二者中心区呈水样信号，亚急性期血肿T1WI与T2WI均呈高信号；粘液变性区T1WI呈略低，等或略高信号，T2WI呈高信号。结论：根据病变囊性区MRI信号特征可推测其囊性成分，结合其他MRI表现，多数囊性软组织病变的的组织来源可以正确推断。