The direct effect of insulin on organ cultures of brown fat

The Effect of Ultrasonic Liposuction Energy Levels on Fat Graft Viability

BACKGROUND

The use of fat obtained from ultrasound-assisted liposuction is popular. However, no study has considered the effect of different energy levels on fat grafts.

OBJECTIVES

We hypothesized that different ultrasonic energy levels could change the fat graft viability.

METHODS

Both flanks of 15 CD1 nude mice (30 experimental areas) were used, with experimental areas randomly distributed into five groups. Using different energy settings, fat grafts were obtained from a patient's abdominoplasty material and applied to the mouse flank regions. Device settings were intermittent mode with 50% vibration amplitude in group 1, continuous mode with 50% vibration amplitude in group 2, intermittent mode with 90% vibration amplitude in group 3, and continuous mode with 90% vibration amplitude in group 4. The control group was grafted with fat obtained via the conventional method. After 6 weeks, all mice were sacrificed, and fat grafts were excised. Sections were stained with hematoxylin-eosin, Masson's trichrome, and anti-perilipin A antibody.

RESULTS

The perilipin A immunostaining result was lowest in group 4, indicating the lowest viable cell count (p < 0.01). There was no significant difference between groups for the other parameters (p > 0.05).

CONCLUSION

High ultrasonic energy may affect fat graft survival. If fat injection is planned, avoiding high energy settings (our recommendation is not to exceed 16 Watts.) should be considered. We also recommend increasing the vibration amplitude rather than switching from intermittent to continuous mode in body parts that are relatively resistant to liposuction.

NO LEVEL ASSIGNED

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Autologous Fat Transplantation

A preliminary analysis of the methods that have been used and the results achieved since fat grafts were first used in 1889 is presented. Descriptions of the techniques used by several practicing physicians were collected by personal communication and a review of the literature and are recorded in this paper. Although the process of fat transplantation has not been standardized, it can no longer be considered an experimental procedure as enough surgeons have shown that there can be consistently good results. Failures and complications are not the result of the theory that fat cannot be transplanted, but the result of errors in technique and not adequate attention to detail.

Fat Transplantation and Facial Contour

Injection of adipose tissue into corporal depressions to improve contour is not a new procedure. According to the literature, the grafted fat undergoes ischemia, producing a local inflammatory process and reabsorption of part of the injected volume, and the desired result is not achieved. Starting from the premise that vascular insufficiency occurs in the core of grafted tissue, leading to reabsorption, the authors of this paper studied the outcome of injection of small volumes of fat into facial depressions. The subjects, 16 patients with facial depressions (12 with Romberg's syndrome and 4 with lupus), were subjected to small volumes of adipose tissue grafting. Three to seven sessions of fat grafting were necessary to obtain a uniform facial contour. The interval between each procedure was 2–3 months. Ultrasonography and biopsies were performed. The cutaneous ultrasound demonstrated viable adipose tissue, confirming the pathological result.

Enhancement of Autologous Fat Transplantation with Platelet Rich Plasma

Introduction:

Adipose tissue is readily available for autotransplantation. Over many years, the popularity of fat transplantation surgery has waxed and waned as a result of relatively inconsistent and unpredictable survival. Many factors influence the success of autologous fat tissue grafts, some of which can be controlled by the surgeon. Examples include the use of minimally traumatic cannulae, low pressure suction, careful handling of graft tissues, and aseptic techniques. There is emerging evidence that fat grafts may be made more reliable and consistent by careful selection of donor sites and by influencing certain healing mechanisms that control cellular recruitment, migration, and differentiation at the recipient site.

Materials and Methods:

This paper presents an innovative technique that provides a means to isolate autologous platelet rich plasma for use with autologous fat for the purposes of enhanced tissue augmentation.

Results:

The apparent concentration and greater quantity of cellular grafts observed after utilization of these techniques seem to yield a higher proportion of graft volume retention.

Discussion:

This technique is intended to promote or accelerate the healing phase after grafting, enhance the intended augmentation retention volume, potentially reduce secondary calcifications and microcyst formation, and maximize the transplant unit volume by reducing the extracellular fluids transferred with the grafts.

Refeeding-induced brown adipose tissue glycogen hyper-accumulation in mice is mediated by insulin and catecholamines

Brown adipose tissue (BAT) generates heat during adaptive thermogenesis through a combination of oxidative metabolism and uncoupling protein 1-mediated electron transport chain uncoupling, using both free-fatty acids and glucose as substrate. Previous rat-based work in 1942 showed that prolonged partial fasting followed by refeeding led to a dramatic, transient increase in glycogen stores in multiple fat depots. In the present study, the protocol was replicated in male CD1 mice, resulting in a 2000-fold increase in interscapular BAT (IBAT) glycogen levels within 4-12 hours (hr) of refeeding, with IBAT glycogen stores reaching levels comparable to fed liver glycogen. Lesser effects occurred in white adipose tissues (WAT). Over the next 36 hr, glycogen levels dissipated and histological analysis revealed an over-accumulation of lipid droplets, suggesting a potential metabolic connection between glycogenolysis and lipid synthesis. 24 hr of total starvation followed by refeeding induced a robust and consistent glycogen over-accumulation similar in magnitude and time course to the prolonged partial fast. Experimentation demonstrated that hyperglycemia was not sufficient to drive glycogen accumulation in IBAT, but that elevated circulating insulin was sufficient. Additionally, pharmacological inhibition of catecholamine production reduced refeeding-induced IBAT glycogen storage, providing evidence of a contribution from the central nervous system. These findings highlight IBAT as a tissue that integrates both canonically-anabolic and catabolic stimulation for the promotion of glycogen storage during recovery from caloric deficit. The preservation of this robust response through many generations of animals not subjected to food deprivation suggests that the over-accumulation phenomenon plays a critical role in IBAT physiology.

La greffe de tissu adipeux : mythe ou réalité scientifique. Lecture critique de la littérature

Fat grafting is an old technique. Since its first description in 1893, fat was used in a lot of indications. After more then a century of evolution, there is still no commonly accepted standard method of fat transfer by all the authors. On the contrary, many different techniques have been described in the literature with the only aim of reducing resorption of the transferred fat. Today the main inconvenient of fat grafting remains the partial resorption the transferred tissue. After a review of the literature of the various technique of fat transfer presented according to their chronology in the operative procedure, we have observed that the techniques developed by certain authors are the opposite of the techniques developed by others. This shows the lack of rigorous work concerning the fat transfer. Whether they are experimental or clinical, in most of these studies, we can find at least one skew which could have influence the results and the conclusion of these studies. A critical revue of the literature offers the opportunity to reconsider the actual bases of fat transfer. The use of an objective way of quantifying the volumes in clinical practice could permit the comparison of different studies in the future.

Searching for the favorable donor site for fat injection: in vivo study using the nude mice model

BACKGROUND

The use of suctioned fat grafts for correction of soft tissue defects is a widespread procedure in esthetic and reconstructive surgery. The main disadvantage of this simple and sensible procedure is the unpredictable absorption rate of the fat graft. A lot of research has been performed aiming for enhancement of the take of the fat grafts.

OBJECTIVE

Our study was performed to find if there is any favorable donor site for fat harvesting.

METHODS

This in vivo experiment using the nude mice model enables the study of the long-term survival of human fat in an animal model. The fat was harvested from three donor areas: the thigh, abdomen, and breast of a 48-year-old woman who came for an elective esthetic procedure. After centrifugation, 1 cc of fat was injected subcutaneously into the scalp of the nude mouse. There were 15 mice in each of the three groups, according to the selected donor sites. The animals were sacrificed 16 weeks after the procedure. The extracted fat was evaluated in terms of weight, volume, and six histologic parameters: integrity, vascularization, cyst formation, fibrosis, necrosis, and inflammation.

RESULTS

This study could not find any statistically significant differences between the three investigated donor sites in the evaluated parameters.

CONCLUSION

On the basis of this study, there is no favorable area for harvesting fat grafts. The donor site can be chosen according to the preference of the surgeon and the patient.

The effect of interleukin-8 on the viability of injected adipose tissue in nude mice

Adipose tissue injection as a free graft for the correction of soft-tissue defects is a widespread procedure in plastic surgery. The main problem in achieving long-term soft-tissue augmentation is partial absorption of the injected fat and hence the need for overcorrection and re-injection. The purpose of this study was to improve the viability of the injected fat by the use of interleukin-8. The rationale for the use of interleukin-8 was its abilities to accelerate angiogenesis and attract inflammatory cells and fibroblasts, providing the injected adipocytes more feeding vessels and a well-established graft bed to enhance their viability. Human adipose tissue, obtained by suction-assisted lipectomy, was re-injected into the subcutis in the scalp of nude mice. Interleukin-8 (0.25 ng) was injected subcutaneously to the scalp as a preparation of the recipient site 24 hours before the fat injection and was added to the fat graft itself (25 ng per 1 cc of injected fat). In the control group, pure fat without interleukin-8 was injected and no interleukin-8 was added for the preparation of the recipient site. One cubic centimeter of fat was injected in each animal in both the study and control groups. There were 10 animals in each group. The animals were euthanized 15 weeks after the procedure. Graft weight and volume were measured and histologic evaluation was performed. In addition, triglyceride content and adipose cell sizes were measured as parameters for fat cells viability. Histologic analysis demonstrated significantly less cyst formation in the group treated with interleukin-8. No significant differences were found between the groups with regard to graft weight and volume or the other histologic parameters investigated. No significant differences were demonstrated in adipose cell sizes and their triglyceride content. In conclusion, less cyst formation, indicating improved quality of the injected fat, can be obtained by the addition of interleukin-8. Further studies of various dosages of interleukin-8 and their long-term effect are required before these encouraging results could be applied clinically.

In Search of Improved Fat Transfer Viability: A Quantitative Analysis of the Role of Centrifugation and Harvest Site

Fat grafting is an unpredictable procedure that continues to challenge the field of plastic surgery due to irregular resorption. Applications for this procedure are broad in both reconstructive and cosmetic plastic surgery. Fat grafts are carefully obtained and manipulated to obtain better graft takes and results, yet there is no universal agreement on what constitutes an ideal methodology. The present study examines adipocyte viability from four commonly used donor sites in five subjects. No statistical differences in adipocyte viability were demonstrated among abdominal fat, thigh fat, flank fat, or knee fat donor sites that were immediately removed and untreated (p < 0.225). In addition, no differences were observed in representative tissue samples that were removed and centrifuged (thigh, p = 0.508; knee, p = 0.302; flank, p = 0.088; abdomen, p = 0.533). On the basis of these quantitative data, neither harvest location nor centrifugation demonstrated any advantage in terms of lipocyte viability. Fat tissue transfers from these common sites may be considered equal, and centrifugation does not appear to enhance immediate fat tissue viability before implantation.

Post acne scarring: a review

Historically, post acne scarring has not been well treated. New techniques have been added and older ones modified to manage this hitherto refractory problem. The patient, his or her expectations and overall appearance as well as the morphology of each scar must be assessed and treatment designed accordingly. Upon reaching an understanding of what the pathology of the scar is and where it resides in the skin, the most pertinent treatment for that scar may be devised. Post acne scars are polymorphous and include superficial macules, dermal troughs, ice picks, multi-channelled fistulous tracts and subcutaneous atrophy. The wide variety of new methods includes the latest resurfacing tools such as CO(2) and erbium infrared lasers, dermasanding and possibly some future techniques such as non-ablative and radiofrequency resurfacing. Dermal and subcutaneous augmentation with autologous (including fat and blood transfer) and non-autologous tissue augmentation and the advent of tissue undermining has greatly improved the treatment of atrophic scars. Use of punch techniques for sharply marginated scars (such as ice picks) is necessary if this scar morphology is to be treated well. One should attempt to match each scar against an available treatment as far as possible. Many of these techniques may be performed in a single treatment session but repeat treatments are often necessary. The treatment of hypertrophic acne scarring remains difficult, but silastic sheeting, vascular laser and intralesional cytotoxics are interesting developments. Most often occurring extra-facially and in males, these distressing scars often require multiple treatments and modalities before adequate improvement is achieved.

The fat pearl graft in ophthalmic plastic surgery: everyone wants to be a donor!

Autogenous fat pearl grafting offers a solution to several difficult problems in ophthalmic plastic surgery. These include lower eyelid contour and tear trough deformities, depressed scars, and upper eyelid crease asymmetries and hollow superior sulci. The grafting technique is easily learned and patient satisfaction is high.

The behavior of fat grafts in recipient areas with enhanced vascularity

Fat grafts are used for soft-tissue augmentation of various anatomic regions, most frequently for the improvement of facial contours. Resorption of the graft is the main problem, and several different procedures have been described to minimize this phenomenon. Using 25 New Zealand rabbits, the behavior of fat grafts in a highly vascularized recipient site was studied. The recipient sites prepared on the backs of the rabbits were divided into four regions. A capsule formation with silicone sheet application was accomplished in two of these recipient areas before the transplantation of the fat grafts. Fat grafts were placed in the other two recipient areas without any prior preparation. We prepared two types of fat tissue; in one the lobular structure was preserved and in the other it was manually crushed and rinsed with lactated Ringer's solution. The fat tissues with preserved lobular structure were placed in area I and area III. Manually crushed and rinsed fat tissues were placed in area II and area IV. In areas III and IV, a capsule formation with silicone sheet had been accomplished 3 weeks before grafting. Biopsy samples were obtained from these sites at the end of the first, third, sixth, and tenth months. Our aim was to observe the histologic fate of fat tissue in different recipient areas. The macroscopic and microscopic evaluation of the fat grafts in areas with silicone sheet indicated significant differences in the resorption time of the fat grafts; however, it was concluded that the significant resorption of the transplanted autologous fat tissue grafts at the end of the first year was an inevitable consequence of fat grafting.

Postacne scarring: a review of its pathophysiology and treatment

BACKGROUND

There has been a largely unheralded revolution in the number of techniques that can now be used in the treatment of atrophic postacne scarring. Atrophic scarring is the more common type of scarring encountered after acne.

OBJECTIVE

To illustrate the range of techniques useful in the therapy of postacne scarring, their relative advantages and disadvantages, and their place in treatment.

METHOD

A review of available techniques is used to illustrate the treatment of indented or atrophic acne scars.

RESULTS

The individual architecture of the indented scar must be assessed so that treatment may be designed to maximize its improvement. A variety of new methods now exist, including newer resurfacing tools such as infrared lasers, dermasanding, and others in their infancy such as nonablative resurfacing and radiofrequency methods. A true explosion in autologous and nonautologous tissue augmentation and the advent of tissue undermining and the use of punch replacement techniques has added more precision and efficacy to the treatment of these scars.

CONCLUSION

Atrophic postacne scars may be satisfactorily treated in many patients, but multiple methods are often required to ensure the best results.

Management of post-acne scarring. What are the options for treatment?

Post-acne scarring is a very distressing and difficult problem for physician and patient alike. Recently, newer techniques and modifications to older ones may make this hitherto refractory problem more manageable. Options for dealing with post-acne scarring are explored. The patient, his or her overall appearance and the morphology of each scar must be assessed and treatment designed accordingly. To adequately address the patient with scarring, a thorough knowledge of the pathophysiology and anatomy of the different types of scars should be sought. Once an understanding of what the pathology is and where it is occurring is attained, the most pertinent treatment for that scar may be devised. A variety of post-acne scars is produced including superficial macules, dermal troughs, ice picks, multi-channelled fistulous tracts and subcutaneous atrophy. The wide variety of new treatment methods for post-acne scarring includes newer resurfacing tools such as CO2 and erbium infrared lasers, dermasanding and possibly some future techniques such as non-ablative and radiofrequency resurfacing. Dermal and subcutaneous augmentation with autologous and nonautologous tissue augmentation and the advent of tissue undermining have greatly improved treatment of atrophic scars. Use of punch techniques for sharply marginated scars (such as ice picks) is necessary if this scar morphology is to be treated well. One should attempt to match each scar against an available treatment as far as possible. Many of these techniques may be performed in a single treatment session but repeat treatments are often necessary. The treatment of hypertrophic acne scarring remains difficult, but silastic sheeting, vascular laser, and intralesional cytotoxics are interesting developments. Most often occurring extra-facially and in males these distressing scars often require multiple treatments and modalities before adequate improvement is achieved.

The effect of preoperative needle abrasion of the recipient site on survival of autologous free fat grafts in rats

Pads of fat ranging from 670-1758 mg in weight were taken from the right groins of 20 rats and implanted subcutaneously over their right pectoral muscles. One week previously the recipient site on the thorax had been abraded with a needle in 10 of the rats. After three months the transplanted fat was taken out, weighed, and examined histologically by light microscopy. Regional tissue blood flow in the transplanted fat and in the fat from the left groin was measured by the microsphere technique. The amount of surviving fat and blood flow in the fat transplanted to an abraded recipient site was significantly higher than in the control group after three months. We conclude that preoperative needle abrasion of the recipient site may increase the chance of revascularisation and survival of the transplanted fat in rats.

Monolayer cultures of disaggregated human adipocytes

Two theories have been advanced to explain the origin of adipocytes and both have experimental evidence in support. One theory proposed that adipocytes are specialized differentiated cells with specific lipid storage functions. The other held that they are unspecialized anlage cells which have the potential to store lipids depending on conditions. In an attempt to examine the little understood roles which these cells play in obesity and other abnormalities of lipid metabolism, disaggregated human adipocytes from infants and young children, free of stromal contamination, have been successfully grown in culture. The details of the techniques used, and some peculiar morphological characteristics of these cells in culture, are described.