Computed tomographic symptomatology of lymphedema of the lower extremities]

CT potentialities in the diagnosis and differential diagnosis of lower limb lymphedema in 40 patients (11 men and 29 women), aged 16 to 56, are illustrated. Eighty studies on the limbs were performed to 20 patients with primary lymphedema, 6 with congenital lymphedema, 26 with secondary lymphedema, and 28 with unaffected limbs. The data were statistically processed according to the following parameters: leg diameter, skin and subcutaneous fat thickness and density, the presence of fibrosis in subcutaneous fat, its localization, shape and spreading, fascial thickness. CT permitted objective assessment of disease and a right choice of a type of surgical intervention.     

Neuromuscular response to varying pressures created by tightness of restriction cuff

Variation in regional body composition between genders may change the degree of pressure created by the tightness of cuff used during blood flow restriction training resulting in changes in the level of neuromuscular activation. This study investigates the effects of tightness of cuff and skin and subcutaneous fat thickness on electromyography (EMG) amplitude (RMS) and median frequency (MDF) during exercises and strength testing. Subjects performed knee-extension exercises with varying tightness of cuff while using EMG to measure changes in neuromuscular response. EMG RMS was significantly affected by tightness of cuff and skin and subcutaneous fat thickness. The strongest individual variable for the changes in MDF was also skin and subcutaneous-fat thickness. The changes in EMG response due to tightness of cuff and the effect of skin and subcutaneous fat thickness on tightness of cuff prove the importance of details on BFR protocol and leg composition on neuromuscular function during BFR exercises.     

Influences of probe application on the measurement of subcutaneous thickness using A-mode ultrasonography

The purpose of the present study was to investigate the effects of the way of probe application on the values of subcutaneous fat thickness by use of A-mode ultrasonography . Subjects were six healthy male adults ranging in age from 19 to 35 years. Scapular, triceps, supra-iliac, abdomen, and thigh were chosen for the measurement sites. Observed values of subcutaneous fat decreased with the increase of pressure at scapular, supra-iliac, and abdomen for relatively fatty subjects, but not for lean subjects. However, the values showed little change at triceps and thigh for all subjects. There was no relation between the pressure of probe and the stability of the value. The values were also influenced by the displacement of the probe on skin. Moreover, it was shown that the difference of the angle between probe and skin influenced the values of subcutaneous fat thickness. A-mode ultrasonography++ has many advantages, if it is properly operated considering the above problems.     

Analysis of shear wave propagation in skin; application to an experimental procedure

An analysis of an experimental procedure used to determine age-related changes in the skin was performed. The experiment is based on the propagation of a shear wave through the skin. The analysis of the experiment was used to determine the effects of parameters such as properties of the skin and subcutaneous fat, skin thickness and experimental conditions on the propagation. Computer simulations showed that at lower frequencies (less than 1000 Hz), measured results depended strongly on skin thickness, while at higher frequencies (2000 Hz) the results were relatively insensitive to both skin thickness and the properties of the subcutaneous fat. Results also depended upon the distance between the applied shear disturbance and the measurement point. The analysis suggests that higher frequency (2000 Hz) experimental results are more indicative of mechanical properties of skin than lower frequency (less than 1000 Hz) results.     

Sex differences in the distribution of subcutaneous and internal fat

One-hundred twenty-one male and 93 female subjects, aged 18-23 years, were selected for an investigation of the proportion of subcutaneous to total fat in the whole body. Body fat mass was calculated from body density using the Siri equation. Subcutaneous fat mass was calculated by measuring skinfold thickness at 15 sites and using a modification of the equation derived by Skerjl, Brozek, and Hunt. The main modification to this equation was the introduction of a midlayer area of subcutaneous tissue that is multiplied by fat thickness to give fat volume. The outermost body surface area, which has been utilized in previous research, results in an overestimation of the true subcutaneous fat mass. The average percentages of fat situated subcutaneously (PFSSs) were calculated as 53.7% for males and 62.6% for females. This sex difference is also seen in correlation-regression analysis of PFSS and percentage of fat. In females PFSS decreases with increasing total percentage of fat, whereas in males there is no significant relationship between PFSS and total percentage of fat. This suggests that the proportion of subcutaneous to total fat distribution is negatively related to fatness in females.     

Enhanced absorption of millimeter wave energy in murine subcutaneous blood vessels

The aim of the present study was to determine millimeter wave (MMW) absorption by blood vessels traversing the subcutaneous fat layer of murine skin. Most calculations were performed using the finite-difference time-domain (FDTD) technique. We used two types of models: (1) a rectangular block of multilayer tissue with blood vessels traversing the fat layer and (2) cylindrical models with circular and elliptical cross-sections simulating the real geometry of murine limbs. We found that the specific absorption rate (SAR) in blood vessels normally traversing the fat layer achieved its maximal value at the parallel orientation of the E-field to the vessel axis. At 42 GHz exposure, the maximal SAR in small blood vessels could be more than 30 times greater than that in the skin. The SAR increased with decreasing the blood vessel diameter and increasing the fat thickness. The SAR decreased with increasing the exposure frequency. When the cylindrical or elliptical models of murine limbs were exposed to plane MMW, the greatest absorption of MMW energy occurred in blood vessels located on the lateral areas of the limb model. At these areas the maximal SAR values were comparable with or were greater than the maximal SAR on the front surface of the skin. Enhanced absorption of MMW energy by blood vessels traversing the fat layer may play a primary role in initiating MMW effects on blood cells and vasodilatation of cutaneous blood vessels.     

Skin reflectance relationships with temperature and skinfolds

Skin reflectance measurements were taken with six filters at a site on the medial aspect of the upper arm (underarm) prior to and following topical application of a cold compress. Skinfolds were measured at the underarm and triceps sites. The experiment was designed to test for effects of skin surface temperature and subcutaneous fat variations on skin color as determined by reflectometry. Topical cold-induced erythema of the skin produced marked declines in % reflectance at the shorter visible wavelengths over the range of violet, blue, and green, and only slight declines in % reflectance at the longer visible wavelengths (red range). This is consistent with the observation from past work that there is little hemoglobin absorptance at the red end of the visible spectrum. A positive relationship between the change in % reflectance following topical cold application and underarm skinfold was recorded. Hence, the thickness of fat deposits may contribute to variation in skin reflectance. Since only large temperature differences influenced skin reflectance measurements, the need is not great for fieldworkers to control for surface temperature at the underarm site during skin reflectance survey.     

Individual variability in the structure of the walls of the principal trunks of the subcutaneous veins of the lower extremities of the human fetus

Certain regional peculiarities are noted in the development process of the human principle trunks of the subcutaneous veins during antenatal period. In the fetuses of all ages the wall thickness of the subcutaneous veins is the greatest in the femur, and the middle tunic is better developed in the shin. The vein structure depends on the type of architectonics: at the magistral type (86%) the walls in the large and minor subcutaneous veins are thick with well developed smooth myocytes and connective tissue fibers; at the reticulate type (14%) the walls are thin, their elements are poorly developed. When there is mentioned varicosity of the lower extremity veins in the parents' anamnesis, in fetuses (57%) all the tunics in the venous wall develop more poorly, there is retardation in formation of smooth myocytes and in maturation of collagen fibers. This results in less amount of contractile structures in the middle tunic and optic density of collagen is less manifected.     

Anatomical study of the venous drainage architecture of the scapular skin and subcutaneous tissue.

Venous anatomy of the skin and subcutaneous adipofascial tissue in the scapular region was examined in 14 specimens of 12 fresh cadavers that had been injected systemically with contrast medium. Three-dimensional analysis was performed by radiographing the specimens stereoscopically and splitting them into the skin and subcutaneous adipofascial tissue layers. From the architecture, most of the venous blood that had perfused the dermis was considered to pool in a polygonal venous network, located in the skin layer; to flow chiefly through some large communicating veins; and to enter the scapular, parascapular, or circumflex scapular veins. Most of the venous blood that had perfused the subcutaneous adipofascial tissue was considered to enter the scapular or parascapular veins directly.     

The venous skin graft method for repairing skin defects of the fingers

A venous skin graft for the treatment of skin defects in a finger is described. This procedure involves taking a flap from the forearm together with the subcutaneous vein and anastomosing both ends of this vein to the digital artery and vein, respectively. Thirteen difficult finger wounds were resurfaced with such a venous skin graft. The sizes of the flaps ranged from 1.3 X 3.0 cm to 2 X 5 cm. The lengths of the veins taken were from 6 to 12 cm. Subcutaneous fat is thin, and there is good elasticity in the grafted flap.     

Pathogenesis of chronic venous insufficiency and possible effects of compression and pentoxifylline.

It has been recognized for over 2000 years that ulceration of the leg may be associated with visible varices of the lower limb. More recent physiological investigation has shown that the pressure in the veins of the lower limb remains raised in patients with venous ulceration during ambulation, whereas in normal subjects the pressure in superficial veins falls to a low level. This elevated pressure appears to cause damage to the superficial capillaries in the skin culminating in the production of venous ulceration. Events in the dermal capillaries which result in skin destruction have yet to be fully defined. Pericapillary fibrin cuffs have been demonstrated histologically and suggested as a cause of diminished nutrition to the skin. White blood cells have been shown to accumulate in the lower limb of patients with venous disease and these accumulations are particularly located around the dermal capillaries. Activated white blood cells releasing free radicals and destructive enzymes may precipitate skin destruction. An understanding of these mechanisms may help to explain the efficacy of compression hosiery and bandaging as well as some of the new pharmacological agents which have been shown to influence venous ulcer healing.     

Morphometric and hormonal changes during the chimpanzee menstrual cycle

BACKGROUND: Sex steroids affect many peripheral tissue sites in female mammals. Receptors for these hormones have been found in skin, fat, and bone. In women, these tissues can show morphological changes during the menstrual cycle that may be directly related to steroid secretion. METHODS: The present study was done on chimpanzees to document morphometric markers associated with these tissues (anogenital swelling volume, skin fold thickness as indicator of subcutaneous fat, bony diameters of mandible, wrist, and elbow) and to compare them with cyclic patterns of estradiol, progesterone, testosterone, gonadotropins, and prolactin. RESULTS: Swelling volume changed significantly over the menstrual cycle. All other morphometric parameters showed variation without statistical significance. Skin folds were thickest during the luteal phase. Bony diameters displayed similar but less distinctive changes. Testosterone correlated positively with diameter sites, inversely with subcutaneous fat. No relationships with either estradiol or progesterone were found. We assume that subcutaneous fat and morphometric bone parameters exhibit cycle-dependent changes that may be caused by changes in steroid secretion.     

X-ray semeiotics of changes in the soft tissues and bones of the lower extremities in disorders of the venous outflow

In order to improve radiodiagnosis of chronic and venous insufficiency of the lower limbs, the soft tissues and skeleton of the affected limbs were x-rayed in 120 patients with disturbed venous outflow (60 with varicosity and 60 with the post-thrombophlebitic syndrome - PTPS). The limb soft tissue changes in this disease were shown to be of one type and looked like the thickening of subcutaneous fat; obscure boundaries of the muscles with subcutaneous fat, the narrowing of intermuscular layers, the absence of differentiation of separate muscular groups, visible varices, calcifications of soft tissues and phleboliths. Bone changes appeared later than the clinical signs of disease and were as follows: regional and diffuse osteoporosis, various kinds of periostoses (scaled or partially assimilated linear, multilayer and pectiniform) and hyperostosis. Longitudinal platypodia and transverse foot flattening caused by dysfunction of the musculoligamentous apparatus and increasing venous congestion in the lower limbs were seen in most of the patients.     

Anthropometric changes associated with high altitude acclimatization in females

The anthropometric effects of prolonged high altitude exposure were studied in eight college women who lived on the summit of Pikes Peak (14,100 ft.) for 2.5 months. Acclimatization to altitude was associated with a decrease of skin-fold thickness and a reduction in limb circumference, but little change in body weight. It was concluded that these changes reflected a loss of subcutaneous fat during the period of altitude exposure. Altitude exposure did not produce any alterations in trunk circumference at the umbilicus or buttocks, but it did cause an increase in the inspiratory chest circumference at the axillary level and a reduction in expiratory chest circumference at the subscapular level.     

Development of the Mouse Dermal Adipose Layer Occurs Independently of Subcutaneous Adipose Tissue and Is Marked by Restricted Early Expression of FABP4

The laboratory mouse is a key animal model for studies of adipose biology, metabolism and disease, yet the developmental changes that occur in tissues and cells that become the adipose layer in mouse skin have received little attention. Moreover, the terminology around this adipose body is often confusing, as frequently no distinction is made between adipose tissue within the skin, and so called subcutaneous fat. Here adipocyte development in mouse dorsal skin was investigated from before birth to the end of the first hair follicle growth cycle. Using Oil Red O staining, immunohistochemistry, quantitative RT-PCR and TUNEL staining we confirmed previous observations of a close spatio-temporal link between hair follicle development and the process of adipogenesis. However, unlike previous studies, we observed that the skin adipose layer was created from cells within the lower dermis. By day 16 of embryonic development (e16) the lower dermis was demarcated from the upper dermal layer, and commitment to adipogenesis in the lower dermis was signalled by expression of FABP4, a marker of adipocyte differentiation. In mature mice the skin adipose layer is separated from underlying subcutaneous adipose tissue by the panniculus carnosus. We observed that the skin adipose tissue did not combine or intermix with subcutaneous adipose tissue at any developmental time point. By transplanting skin isolated from e14.5 mice (prior to the start of adipogenesis), under the kidney capsule of adult mice, we showed that skin adipose tissue develops independently and without influence from subcutaneous depots. This study has reinforced the developmental link between hair follicles and skin adipocyte biology. We argue that because skin adipocytes develop from cells within the dermis and independently from subcutaneous adipose tissue, that it is accurately termed dermal adipose tissue and that, in laboratory mice at least, it represents a separate adipose depot.     

布朗族成人的身体成分分析

本文采用生物阻抗分析法,研究了布朗族成人的体成分特点。我们在云南省测量了604例(男性248例,女性356例)布朗族成人19项身体成分指标,运用Excel 2003、Spss 19.0对其各项指标进行统计分析。结果显示,男性全身脂肪分布特征为躯干和下肢的脂肪率都大于上肢脂肪率,女性脂肪率从大到小依次为下肢、躯干、上肢;男、女性双侧下肢脂肪率和肌肉量接近,左上肢肌肉量低、脂肪率高;布朗族男性的身高、体质量、肌肉量、推定骨量、总能量代谢、水分率、内脏脂肪等级均大于女性,而体脂率、BMI小于女性。随着年龄的增长,布朗族成人身体肌肉量、骨量、下肢脂肪率、能量代谢等呈明显下降,而内脏脂肪等级明显增加。与云南汉族比较,布朗族成人的体脂率较低、肌肉较发达。     

Hand rejuvenation with structural fat grafting

A simple, reliable technique of autologous fat grafting for long-lasting rejuvenation of the dorsum of the hand is presented. With this technique, small intact parcels of fatty tissue are harvested with a syringe and a blunt 3-mm cannula. Then, most of the nonviable components are removed from the harvested subcutaneous material by centrifugation, decanting, and wicking. Finally, a 17-gauge blunt cannula places the fat in minuscule parcels of tissue with many passes through five or six tiny incisions in the hand. Separation of the tiny parcels of fat maximizes contact between the surfaces of the transplanted fat and surrounding recipient tissues to encourage integration, anchoring, and long-term survival. Structured, purposeful placement of a thin layer of transplanted fat rejuvenates the dorsal hand by restoring a slight fullness to atrophic subcutaneous tissue, by softening the color and definition of exposed extensor tendons and dorsal hand veins, and by supporting the aging skin.     

Changes in the human fat mass from the ages of 6 to 18

In 2,300 persons of both sex, 6, 8, 10, and 18 years of age, using the caliper of "Holtein"-type for measuring thickness of skin-fat folds, age dynamics in distribution of subcutaneous fat, as well as general, subcutaneous and internal fat have been estimated. Both in boys and girls at the age of 6-12 years the place of the greatest accumulation of the subcutaneous fat is the anterior surface of the femur; its least layer up to 10 years of age is localized on the brachium, and at the age of 12 and 18 years--on the forearm. The subcutaneous fat mass from 6 up to 12 years of age increases more than 3 times, while the body mass at the same time increases only by 91-98%. The most significant increment of the general fat mass is noted at 10-12 years of age. In 6-year-old children the part of the subcutaneous fat in the body mass is less than that of the internal fat. By 12 years of age the relative mass of the subcutaneous fat increases, and that of the internal fat remains practically the same. This, evidently, demonstrates that equilibrium between volumetric characteristics of tissues in the internal medium of the organism is preserved in the process of its age development. Up to 12 years of age sexual differences in the dynamics of all the parameters are insignificant. Comparing with the adolescents, in 18-year-old boys fat mass--body mass ratio decreases, and in the girls it continues to increase.(ABSTRACT TRUNCATED AT 250 WORDS)     

Insulin sensitivity and regional fat gain in response to overfeeding

Although insulin resistance and type 2 diabetes (T2DM) are associated with upper body fat distribution, it is unknown whether insulin resistance predisposes to upper body fat gain or whether upper body fat gain causes insulin resistance. Our objective was to determine whether insulin sensitivity predicts abdominal (subcutaneous and/or visceral) fat gain in normal weight adults. Twenty-eight (15 men) lean (BMI = 22.1 ± 2.5 kg/m(2)), healthy adults underwent ~8 weeks of overfeeding to gain ~4 kg fat. Body composition was assessed before and after overfeeding, using dual-energy X-ray absorptiometry (DXA) and abdominal computed tomography to measure total and regional (visceral, abdominal, and lower body subcutaneous) fat gain. We assessed insulin sensitivity with an intravenous glucose tolerance test (IVGTT) and the 24-h insulin area under the curve (AUC). We found a wide range of insulin sensitivity and a relatively narrow range of body fat distribution in this normal weight cohort. Participants gained 3.8 ± 1.7 kg of body fat (4.6 ± 2.2 kg body weight). The baseline 24-h AUC of insulin concentration was positively correlated with percent body fat (r = 0.43, P < 0.05). The contribution of leg fat gain to total fat gain ranged from 29 to 79%, whereas the contributions of abdominal subcutaneous fat and visceral fat gain to total fat gain ranged from 17 to 69% and -5 to 22%, respectively. Baseline insulin sensitivity, whether measured by an IVGTT (S(i)) or the 24-h AUC insulin, did not predict upper body subcutaneous or visceral fat gain in response to overfeeding. We conclude that reduced insulin sensitivity is not an obligate precursor to upper body fat gain.     

Kinematic models of the upper limb joints for multibody kinematics optimisation: An overview

Soft tissue artefact (STA), i.e. the motion of the skin, fat and muscles gliding on the underlying bone, may lead to a marker position error reaching up to 8.7 cm for the particular case of the scapula. Multibody kinematics optimisation (MKO) is one of the most efficient approaches used to reduce STA. It consists in minimising the distance between the positions of experimental markers on a subject skin and the simulated positions of the same markers embedded on a kinematic model. However, the efficiency of MKO directly relies on the chosen kinematic model. This paper proposes an overview of the different upper limb models available in the literature and a discussion about their applicability to MKO.The advantages of each joint model with respect to its biofidelity to functional anatomy are detailed both for the shoulder and the forearm areas. Models capabilities of personalisation and of adaptation to pathological cases are also discussed. Concerning model efficiency in terms of STA reduction in MKO algorithms, a lack of quantitative assessment in the literature is noted. In priority, future studies should concern the evaluation and quantification of STA reduction depending on upper limb joint constraints.