Action of Sodium Deoxycholate on Subcutaneous Human Tissue: Local and Systemic Effects

BACKGROUND Phosphatidylcholine injections have been used as a nonsurgical alternative to the surgical removal of undesired fat. Studies in cell culture suggest that sodium deoxycholate (SD) has a detergent action in fat reduction.
OBJECTIVE The objective was to study SD in subcutaneous human tissue.
METHODS AND MATERIALS Thirty volunteers underwent four sessions of subcutaneous abdominal injections of diluted 2.5 or 1% SD stock solutions or placebo. Clinical, hematologic, and ultrasonographic evaluations were performed for 3 months and histology at 3 and 6 months.
RESULTS Both concentrations of SD induced an inflammatory response at the injection site, with dose-dependent adipocyte lysis. Patients reported mild, localized heat, erythema, swelling, and intense pain. Microscopic evaluation revealed necrosis of adipose tissue with adipocyte lysis, fat dissolution, acute lymphomononuclear inflammatory reaction, and intense phagocytosis of fat cells by macrophages. Fibrosis was observed only at the 6-month biopsy. Nodules at the injection sites, compatible with areas of inflammation, were detected by ultrasonography 2 weeks after the first injection. Placebo injections induced no histologic changes.
CONCLUSIONS SD induces an inflammatory reaction in subcutaneous human fat and dose-dependent adipocyte lysis with acute pain and fibrosis. No systemic effects were detected. Further studies will establish the best dose–result ratio, frequency of application, and long-term safety.     

Histopathologic evaluation of adipose autografts in a rabbit ear model

Injection of autologous adipose tissue removed via liposuction has been used clinically for facial contouring, the aging face, furrows, facial atrophy, acne scars, nasolabial folds, chin, and various other surgical defects. Survival rates for autografts of fat have been quoted anywhere from 30% to 80%. Our study uses a reproducible rabbit animal model for autotransplantation of adipose tissue and examines the histopathologic changes that occur to the graft over time. Autogenous subcutaneous fat was removed from a dorsal scapular donor site, treated to stimulate cannula damage as in liposuction, then reinjected at the base of the ear. Histologic examination of the grafts were made at 5, 10, 15, 20, 40, and 100 days after transplantation. Hematoxylin-eosin sections were graded on degree of fibrosis present (0 to 4+), viable fat (1 to 10), degree of inflammation (0 to 4+), and neovascularization (+ or -). Viability of fat decreased from 8.5 to 10 at 5 days to 2 viability at 40 days. Acute inflammation peaked at 10 days, followed by the chronic inflammatory response with macrophages and multinucleated giant cells scavenging the dying fat graft. Neovascularization began at 5 days, peaked at 10 days, and remained constant thereafter only at the edge of the graft. Microcysts appeared at 15 days and increased in number in proportion to the decrease in viable fat. In summary, the temporal histologic events are progressive fibrosis; decreased amount of viable fat; inflammation beginning with a neutrophilic response, later a macrophage and giant cell response; and neovascularization at the periphery of the graft insufficient to maintain graft viability.(ABSTRACT TRUNCATED AT 250 WORDS)     

脂肪注射移植后皮肤质地改善的研究

目的:通过皮下脂肪注射移植,探索移植脂肪对皮肤质地的改善作用。方法:取30只裸鼠,随机分成三组,所有鼠左侧皮下移植人脂肪细胞,在另一侧10只注射硅凝胶,10仅行皮下穿刺,剩下10只无任何处置,8周取皮肤组织做HE、Masson’染色观察皮肤真皮层厚度及真皮层内胶原蛋白的含量。结果:取材时,所有裸鼠上都能看到所移植的脂肪,但体积较术前有较明显缩小。肉眼看,脂肪呈正常外观,有较多新生血管生成。组织学检测,移植脂肪外周有大量细胞外基质形成,实验侧真皮层较对照侧明显增厚,真皮内胶原含量增多。结论:移植的脂肪组织不仅仅是一种填充物,在改善轮廓的同时,还有真皮增厚、胶原含量增加等皮肤改善的效应。     

Detergent Effects of Sodium Deoxycholate Are a Major Feature of an Injectable Phosphatidylcholine Formulation Used for Localized Fat Dissolution

BACKGROUND: Phosphatidylcholine injections are becoming an increasingly popular technique to treat localized fat accumulation. This formula is composed primarily of phosphatidylcholine and sodium deoxycholate, a bile salt used to solubilize the natural phospholipid in water. The mechanism through which this injectable phosphatidylcholine formulation causes localized fat reduction is unknown. OBJECTIVE: To investigate the active component and mechanism of action of an injectable phosphatidylcholine formulation in clinical use. METHODS: Cell viability and cell membrane lysis assays were performed on cell cultures and porcine skin after treatment with the phosphatidylcholine formula, isolated sodium deoxycholate, or common laboratory detergents Triton-X 100 and Empigen BB. In addition, we described the histologic changes after injection of these substances into porcine tissue. RESULTS: A significant and comparable loss of cell viability, cell membrane lysis, and disruption of fat and muscle architecture was seen in cell cultures and tissue specimens treated with the phosphatidylcholine formula and isolated sodium deoxycholate. These findings were similar to the effects produced after treatment with laboratory detergents. CONCLUSIONS: The phosphatidylcholine formula popularly used in subcutaneous injections for fat dissolution works primarily as a detergent causing nonspecific lysis of cell membranes. Our findings suggest that sodium deoxycholate is the major active component responsible for cell lysis. Detergent substances may have a role in eliminating unwanted adipose tissue. It is advised that physicians use caution until adequate safety data are available.     

Histopathologic findings in a human arterial anastomosis after free flap transfer

During the removal of subcutaneous fat 4 months after free groin flap transfer in a 25-yearold male, the anastomosed artery was also removed for histologic examination. The removal of the artery did not impair flap viability. The considerable narrowing of the arterial lumen caused by extensive hyperplasia of the intima suggested a restriction of arterial function. In addition, the internal elastic membrane had disappeared or was partially intact, doubled, and fragmented. Where sutures were tight, necrosis of the media was found, with heavy scar formation. If the sutures were loose, the media remained intact. The tissue of the flap artery was more heavily altered than the tissue of the recipient artery. This was evidently the result of trauma incurred during preparation of the flap vessels. Functional restriction of the anastomosed artery and secondary flap revascularization apparently occurred in a temporally favorable relationship in this case.     

Recovery of skeletal muscle after laceration and repair

Few data are available regarding structural and functional recovery of lacerated skeletal muscle after repair. This study used the extensor digitorum longus muscle of rabbits to document recovery after laceration and repair and a healing period of 12 weeks. Completely lacerated muscles recovered approximately 50% of their ability to produce tension but were able to shorten to 80% of normal. Partially lacerated muscle bellies recovered approximately 60% of their ability to produce tension and normal ability to shorten. Histologic specimens revealed that the lacerations did not cause necrosis of either segment. After the recovery period, histologic and histochemical sections revealed that the distal segment initially isolated from the nerve supply showed histologic changes of fiber atrophy and size variability, increased fibrosis, and nuclear centralization suggestive of denervation. Dense scar separated the two fragments. Data show that skeletal muscle can recover useful but not normal function after laceration and repair.     

Histologic evaluation of the pulsed Nd:YAG laser for laser lipolysis

BACKGROUND AND OBJECTIVES: Laser lipoplasty with pulsed Nd:YAG laser, widely used in Europe and Latin America, has recently been introduced in Japan and the USA. We report histologic analyses of the effects of the laser on human fat tissue. STUDY DESIGN/MATERIALS AND METHODS: Freshly excised human skin and subcutaneous fat were irradiated with the pulsed Nd:YAG laser (SmartLipo, DEKA, Italy). A 1,064 nm laser at 40 Hz and 150 mJ and 100 microseconds-long pulses were used. Methods of exposure were the same as in the clinical application. In the control group, the specimens were cannulated by the handpiece without irradiation. The tissue was studied by scanning electron microscopy and hematoxylin eosin staining. RESULTS: Scanning electron microscopy after irradiation showed greater destruction of human adipocytes than in the control. Degenerated cell membrane, vaporization, liquefaction, carbonization, and heat-coagulated collagen fibers were observed. CONCLUSIONS: Our study showed that the SmartLipo appeared to be histologically effective for destruction of human fat tissue.     

Aristolochic acids induce chronic renal failure with interstitial fibrosis in salt-depleted rats.

Chinese-herb nephropathy (CHN) is a rapidly progressive renal fibrosis associated with the intake of a Chinese herb (Aristolochia fangchi) containing nephrotoxic and carcinogenic aristolochic acids (AA). This study attempted to reproduce the main features of human CHN (renal failure, tubular atrophy, and interstitial fibrosis) in a rat model similar to that of cyclosporin-induced nephropathy. Salt-depleted male Wistar rats received daily subcutaneous injections of either 1 mg/kg body wt AA (low-dose AA group), 10 mg/kg body wt AA (high-dose AA group), or vehicle (control group) for 35 d. On days 10 and 35, assessment of renal function, measurements of urinary excretion of glucose, protein, and leucine aminopeptidase, and histologic analyses were performed (six rats euthanized/group). High-dose AA induced glucosuria, proteinuria, and elevated serum creatinine levels and reduced leucine aminopeptidase enzymuria on days 10 and 35, whereas low-dose AA had no significant effect. Tubular necrosis associated with lymphocytic infiltrates (day 10) and tubular atrophy surrounded by interstitial fibrosis (day 35) were the histologic findings for the high-dose AA-treated rats. In both AA groups, urothelial dysplasia was also observed, as well as fibrohistiocytic sarcoma at the injection site. A short-term model of AA-induced renal fibrosis was established in salt-depleted Wistar rats. These results support the role of AA in human CHN and provide a useful model for examination of the pathophysiologic pathways of renal fibrosis.     

Tissue kallikrein attenuates salt-induced renal fibrosis by inhibition of oxidative stress

BACKGROUND: High salt intake induces hypertension, cardiac hypertrophy, and progressive renal damage. Progressive renal injury is the consequence of a process of destructive fibrosis. Using gene transfer approach, we have shown that the tissue kallikrein-kinin system (KKS) plays an important role in protection against renal injury in several hypertensive rat models. In this study, we further investigated the effect and potential mechanisms mediated by kallikrein on salt-induced renal fibrosis. METHODS: Adenovirus harboring the human tissue kallikrein gene was delivered intravenously into Dahl salt-sensitive (DSS) rats on a high salt diet for 4 weeks. Two weeks after gene delivery, the effect of kallikrein on renal fibrosis was examined by biochemical and histologic analysis. RESULTS: Kallikrein gene delivery resulted in reduced blood urea nitrogen (BUN), urinary protein and albumin levels in DSS rats on a high salt diet. Expression of recombinant human tissue kallikrein was detected in the sera and urine of rats injected with the kallikrein gene. Histologic investigation showed that kallikrein gene delivery significantly reduced glomerular and tubular fibrosis scores and collagen deposition, as well as renal cell proliferation, compared to rats on a high salt diet injected with control virus. Kallikrein gene transfer significantly increased nitric oxide and cyclic guanosine monophosphate (cGMP) levels in conjunction with reduced salt-induced nicotinamide adenine dinucleotide/nicotinamide adenine dinucleotide phosphate (NADH/NADPH) oxidase activity, superoxide production, transforming growth factor-beta1 (TGF-beta1) mRNA and protein levels, and TGF-beta1 immunostaining. CONCLUSION: These results indicate that tissue kallikrein protects against renal fibrosis in hypertensive DSS rats through increased nitric oxide bioavailability and suppression of oxidative stress and TGF-beta expression.     

Presurgical Curettage Appropriately Reduces the Number of Mohs Stages by Better Delineating the Subclinical Extensions of Tumor Margins

Background. Whether presurgical curettage (PC), light curettage performed before Mohs surgery to delineate tumor margin, is appropriate or causes unnecessary removal of normal tissue has not been well established.
Objective. We aim to determine histologically whether PC appropriately increases the size of the stage I specimen or causes unnecessary removal of healthy tissue.
Methods. Before a surgical margin guided by PC was taken, a hypothetical margin determined by visual and tactile assessment alone (no curettage [NC]) was marked outside the clinically defined tumor. Histologic analysis at the NC and the PC margins revealed whether the increase in the stage I specimen as a result of PC was appropriate.
Results. PC appropriately increased the stage I specimen in 21 cases and unnecessarily removed normal tissue in only 1 case. The estimation of tumor margins with PC was 15 times more accurate than with NC (p value = .0012).
Conclusion. For basal cell and squamous cell carcinomas at least 4 mm in diameter, light curettage performed prior to Mohs surgery could better delineate subclinical extensions of the tumor margin and appropriately increase the size of the stage I specimen.     

Effects of Fat Preparation Methods on the Viabilities of Autologous Fat Grafts

Fat grafts are commonly used in plastic surgery, but their unpredictable absorption rates are a considerable disadvantage. Furthermore, no agreement has been reached regarding the method that best enables fat graft survival. This study aimed to evaluate the effects of different preparation methods on fat graft viability. Fat tissue was harvested from the remnants of transverse rectus abdominis musculocutaneous (TRAM) flaps by syringe aspiration. Harvested fat tissue was prepared using three different methods: centrifugation, metal sieve concentration, and cotton gauze concentration. To evaluate the viabilities of fat cells, XTT assays were performed. For the study, 18 nude mice were allocated to three groups: the centrifugation, metal sieve, and cotton gauze groups (6 mice per group). Prepared fat (1 ml) was injected into the nuchal area of the mice, and 12 weeks later, grafts were dissected to determine graft survival rates and subjected to histologic analysis. No significant differences were observed in graft survival rates and histologic findings (necrosis and vascularity) between the three groups. However, histologic analysis found the metal sieve group to have significantly lower fat cell viability and more inflammation than the other two groups. The findings suggest that the closed centrifugation technique has no advantage over the open cotton gauze technique in terms of fat graft viability, and that the metal sieve concentration method is deficient as a preparation method because it can cause grafted fat degradation.     

猪皮下脂肪吸脂后组织学观察

目的 观察小型猪皮下组织抽吸后的组织学变化。方法 采用注射器和直径为2mm的抽吸管行白色五指山成年小型猪背部皮下吸脂术，于术前及术后不同时间点分别取吸脂区和对照区皮下脂肪组织标本进行肉眼和（或）组织切片观察。结果 抽吸侧皮下脂肪厚度明显变薄。约为对照侧的53.5%。术区脂肪组织中只在真皮下，浅筋膜隔旁和肌膜表面等处瘢痕形成较多且消褪缓慢，术后6-8个月脂肪小叶结构清楚，抽吸后皮下脂肪细胞的大小。形态与对照部位比较无显著意义。结论 吸脂术可明显减少皮下脂肪的厚度。抽吸时避免损伤皮肤和脂肪下肌层可减少术后瘢痕形成。采用细小的抽吸管可进行浅层脂肪抽吸。     

Development of a seeded scaffold in the great omentum: feasibility of an in vivo bioreactor for bladder tissue engineering

OBJECTIVES: Tissue engineering is very promising in bladder reconstruction. However, one of the main problems is to limit the development of ischaemic fibrosis during tissue maturation. We describe a model using the omentum as an in vivo bioreactor for a previously seeded scaffold. METHODS: Bladder biopsies were taken from five female pigs, from which both urothelial and smooth muscle cells cultures were made. These cultured cells were used to seed a sphere-shaped small intestinal submucosa (SIS) matrix, which was transferred into the omentum after 3 wk of cell growth. The grafts were harvested 3 wk later and histologic, immunohistochemical, and functional studies were performed. RESULTS: We obtained a highly vascularized tissue-engineered construct that contracted in response to acetylcholine stimulation. The wall thickness was 4mm, on average. Histologic and immunostaining analysis of the construct confirmed the presence of a multilayer urothelium on the luminal aspect and deeper fascicles organised tissue composed of differentiated smooth muscle cells and mature fibroblasts without evidence of inflammation or necrosis. Large- and small-diameter vessels were clearly identified histologically in the tissue obtained. CONCLUSION: The omentum permitted in vivo maturation of seeded scaffolds with the development of a dense vascularisation that is anticipated to prevent fibrosis and loss of contractility. This in vivo maturation into the omentum could be the first step before in situ implantation of the construct.     

Downregulation of electron transport chain genes in visceral adipose tissue in type 2 diabetes independent of obesity and possibly involving tumor necrosis factor-alpha

Impaired oxidative phosphorylation is suggested as a factor behind insulin resistance of skeletal muscle in type 2 diabetes. The role of oxidative phosphorylation in adipose tissue was elucidated from results of Affymetrix gene profiling in subcutaneous and visceral adipose tissue of eight nonobese healthy, eight obese healthy, and eight obese type 2 diabetic women. Downregulation of several genes in the electron transport chain was the most prominent finding in visceral fat of type 2 diabetic women independent of obesity, but the gene pattern was distinct from that previously reported in skeletal muscle in type 2 diabetes. A similar but much weaker effect was observed in subcutaneous fat. Tumor necrosis factor-alpha (TNF-alpha) is a major factor behind inflammation and insulin resistance in adipose tissue. TNF-alpha treatment decreased mRNA expression of electron transport chain genes and also inhibited fatty acid oxidation when differentiated human preadipocytes were treated with the cytokine for 48 h. Thus, type 2 diabetes is associated with a tissue- and region-specific downregulation of oxidative phosphorylation genes that is independent of obesity and at least in part mediated by TNF-alpha, suggesting that impaired oxidative phosphorylation of visceral adipose tissue has pathogenic importance for development of type 2 diabetes.     

Regional distribution and behavior of the subcutaneous tissue concerning selection and indication for liposuction

The distribution of the fat tissue in the subcutaneous layer is described. Since it has specific characteristics in each region of the human body, careful evaluation of the distribution before selecting patients for surgery is necessary. The subcutaneous tissue after an operation frequently demonstrates a thick and hard fibrosis which is evidence that liposuction should be performd in the lamellar layers. This type of fibrotic tissue in the subcutaneous areola layer often brings on irregularities and ungraceful waves on the skin surface.     

Time- and Dose-Dependent Effects of Chronic Wound Fluid on Human Adult Dermal Fibroblasts

BACKGROUND Wound healing is a biologic process that is altered in patients affected by chronic venous ulcers. The wound microenvironment is reflected in the chronic wound fluid (CWF), an exudate containing serum components and tissue-derived proteins.
OBJECTIVES We investigated the effects of increasing doses of CWF collected from patients suffering from chronic venous ulcers on human adult dermal fibroblasts cultured in vitro and the relationship among CWF effects and treatment length.
METHODS Fibroblasts were treated with 60, 240, and 720 μg/mL CWF for 3 and 7 days. We evaluated cell proliferation and viability by MTT and Trypan blue assay, cell morphology by light microscopy, F-actin microfilaments organization by tetramethylrhodamine B isothiocyanate-conjugated phalloidin, α-smooth muscle actin expression by immunofluorescence, and senescence-associated β-galactosidase activity.
RESULTS CWF induced an increase in cell proliferation in the first 3 days of treatment. In contrast, at 7 days, a strong decrease in cell viability was observed. These changes were related to a cytoskeletal F-actin reorganization and not to fibroblast–myofibroblast differentiation nor to changes in cellular senescence.
CONCLUSIONS This study shows a dose-dependent and biphasic effect of CWF on dermal fibroblasts, suggesting that a continuous exposure to chronic wounds microenvironment may induce late cellular dysfunctions possibly involved in the delayed wound healing.     

Blockade of TGF-beta action ameliorates renal dysfunction and histologic progression in anti-GBM nephritis

BACKGROUND: We tested whether the entire soluble extracellular domain of the human transforming growth factor-beta (TGF-beta) type II receptor, fused to the Fc portion of human immunoglobulin G (IgG1) (Tbeta-ExR) and expressed in skeletal muscles by adenovirus-mediated gene transfer (AdTbeta-ExR), can ameliorate renal dysfunction and histologic progression in a rat experimental anti-glomerular basement membrane (GBM) nephritis. METHODS: Anti-GBM nephritis was induced in Wistar Kyoto rats by an intravenous injection of anti-rat glomerular basement membrane (GBM) sera. At day 1 (24 hours after induction), AdTbeta-ExR (1 x 109 pfu/mL) was injected into the femoral muscle in the treatment group, and an adenovirus vector-expressing bacterial beta-galactosidase (AdLacZ) was injected into the control group. Then, clinical and histologic changes were examined for 3 weeks after the induction of anti-GBM nephritis. RESULTS: Tbeta-ExR was detected in the serum at day 7, but the serum concentration of Tbeta-ExR had decreased below the detectable level by day 14. Although blood pressure and the degree of proteinuria were similar in both groups, the deterioration of renal function was significantly blunted in the treatment group. Crescent formation and interstitial fibrosis were also ameliorated in the treatment group. These histologic improvements were accompanied by the decreased interstitial infiltration of macrophages and the decreased alpha-smooth muscle actin (alpha-SMA)-positive cells in the glomeruli and the interstitium. CONCLUSION: This study demonstrated for the first time that the blockade of TGF-beta action by AdTbeta-ExR in the early stage of anti-GBM nephritis ameliorates the clinical and histologic progression. In addition, this study shed light on the development of a specific gene therapy for human crescentic glomerulonephritis.     

Double-Blinded, Placebo-Controlled Trial of Green Tea Extracts in the Clinical and Histologic Appearance of Photoaging Skin

Background. Green tea extracts have gained popularity as ingredients in topical skin care preparations to treat aging skin. Green tea polyphenolic compounds have significant antioxidant and anti-inflammatory activities, and studies suggest that these extracts help mediate ultraviolet radiation damage.
Objective. To evaluate the effects of a combination regimen of topical and oral green tea supplementation on the clinical and histologic characteristics of photoaging.
Methods. Forty women with moderate photoaging were randomized to either a combination regimen of 10% green tea cream and 300 mg twice-daily green tea oral supplementation or a placebo regimen for 8 weeks.
Results. No significant differences in clinical grading were found between the green tea–treated and placebo groups, other than higher subjective scores of irritation in the green tea–treated group. Histologic grading of skin biopsies did show significant improvement in the elastic tissue content of treated specimens (p<.05).
Conclusion. Participants treated with a combination regimen of topical and oral green tea showed histologic improvement in elastic tissue content. Green tea polyphenols have been postulated to protect human skin from the cutaneous signs of photoaging, but clinically significant changes could not be detected. Longer supplementation may be required for clinically observable improvements.
THIS STUDY WAS SUPPORTED BY NU SKIN INTERNATIONAL, INC. DR. KIMBALL HAS SERVED AS A CONSULTANT TO NU SKIN AND HAS RECEIVED HONORARIA FOR SPEAKING.     

Topographical relationship between urethral rhabdosphincter and rectourethralis muscle: A better understanding of the apical dissection and the posterior stitches in radical prostatectomy

Objectives:   To clarify the topographical relationship between the urethral rhabdosphincter and the rectourethralis muscle as these structures lying dorsally to membranous urethra are important factors to post-prostatectomy urinary continence.
Methods:   Pelvic floor specimens including prostate, bulbus penis, and anorectum, obtained from 15 male cadavers (ages at death 66 to 80 years), were examined with standard histologic and immunohistochemical techniques using semiserial sagittal and transverse sections.
Results:   The rectourethralis muscle was defined. It was found to be located at the interface between the levator ani muscle and rectum. It was not possible to histologically identify the fibromuscular node known as the perineal body. The urethral rhabdosphincter was found to be inserted into the rectourethralis muscle, which is composed of the smooth muscle fibers. Abundant nerves passed between the rectourethralis muscle and the levator ani, or through the rectourethralis muscle. The urethral rhabdosphincter was closely attached to the apical or ventral portion of the rectourethralis muscle. Morphologically, the membranous urethra was fixed to the rectourethralis muscle through the urethral rhabdosphincter.
Conclusions:   The rectourethralis muscle influences the stabilization of membranous urethra. The posterior stitches for the reconstruction of the dorsal musculofascial plate might injure the nerve fibers running along and through the rectourethralis muscle.     

Cryopreservation of Human Fat for Soft Tissue Augmentation: Viability Requires Use of Cryoprotectant and Controlled Freezing and Storage

Background. Autologous fat transfer for soft tissue augmentation has been increasing in recent years. Graft longevity may vary greatly from patient to patient, requiring repeat procedures, often using frozen adipose tissue. Storage usually involves placing syringes of fat directly into a –20°C freezer. However, the viability of fat frozen in this way is controversial.
Objective. This study tested methods for the optimal storage of adipose tissue harvested by tumescent liposuction.
Materials and Methods. Aliquots of washed adipose tissue were frozen directly at –20°C or mixed with cryoprotectants, frozen at 1°C/min, and subsequently stored in liquid nitrogen vapor phase. Aliquots were subsequently thawed, and adipocyte viability was determined by staining and culture methods.
Results. Viability of adipocytes frozen at –20°C was very low when analyzed by staining, and no cultures could be established from any of the specimens. In contrast, viable adipocytes were recovered from samples that were controlled-rate frozen in the presence of cryoprotectants and stored in nitrogen vapor.
Conclusion. Our results indicate that fat frozen at –20°C is not viable and thus provides no advantage over inert fillers. The methods here described could readily be transferred to the clinical setting after further laboratory study.