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Freeze-substitution and low-temperature embedding of dairy products for transmission electron microscopy.

Dairy products are comprised largely of fat, air and water, which makes it difficult to preserve their ultrastructure for electron microscopy. Keeping the samples frozen throughout fixation and embedding protects the structure and distribution of the components of emulsions and foams. Therefore, dairy products were freeze-substituted and embedded at low temperature (-20 degrees C) to prepare them for transmission electron microscopy. Whipped cream, ice cream mix and dairy/non-dairy mixed systems were frozen by plunging in propane, at its boiling point (-187 degrees C). Ice cream, because it is already frozen, was fractured into 1-mm3 pieces in liquid nitrogen and then added to frozen fixative (-196 degrees C). Fixative solution consisted of glutaraldehyde, osmium tetroxide and uranyl acetate dissolved in either methanol or acetone. When material was to be stained after sectioning the fixative was limited to glutaraldehyde in methanol. The temperature was increased step-wise from -80 to -20 degrees C. Solvent was replaced with resin; the polar resin Lowicryl HM4, the non-polar resin Lowicryl HM20, LR White and LR Gold were tested. Samples were embedded and polymerized at -20 degrees C using ultraviolet light to cross-link the resin. Methanol proved to be the most effective solvent for substituting the ice; the hydrophobic resin Lowicryl HM20 was the most effective resin for retaining fat structure following osmium fixation.

Journal Article↗

Propionate for fatty acid synthesis by the mammary gland of the lactating goat.

Isolated mammary glands of lactating goats were perfused with heparinized and oxygenated blood for 8 to 15 h. Adequate quantities of glucose, acetate, and amino acid were added to the perfusate. After addition of propionate to the perfusion blood, concentrations of odd-numbered and of monomethyl-substituted fatty acids other than those with iso and anteiso configuration increased in the milk fat. These acids seem to be synthesized de novo in the mammary gland. The increase of C17:0 concentration was weak and problematic. We suggest that propionate is acting as a precursor for monomethyl-substituted fatty acids by way of methylmalonyl-CoA. The activating effect of propionate administration upon milk fatty acid production was largest for odd-numbered followed by monomethyl-substituted fatty acids. No increase of iso acids was observed in milk fat in the propionate-infused glands whereas the increase of anteiso acids was extremely small. This agrees with the conception that iso and anteiso fatty acids are synthesized by rumen bacteria.

Animals↗

Comparative study of two techniques for assessing fat intake in a Mediterranean diet. The influence of culinary oils changes.

The diet usually consumed by a community of 18 normolipemic monks was studied. It included olive oil as cooking fat (basal period BP). This diet was modified by substituting olive oil for sunflower oil during a 21-day period (experimental period EP). The precise individual weighing technique was utilised for the determination of intake, and by means of the food composition tables (FCTs) the energy and nutrient of the diet were calculated. By chemical analysis of the duplicate sample (CA) of the cooked dishes the lipid intake was also determined. Total serum cholesterol HDL and LDL cholesterol, serum triglycerides, AI and B-100 apolipoproteins and Lp(a) were also analysed. Similarly the absolute and relative values for SFA, MUFA and PUFA obtained by both techniques were also different and these were maintained when the (PUFA + MUFA)/SFA ratio was calculated by both techniques and in the two periods. The correction of the lipid intake by means of the CA technique did not improve either the correlation between the intake or the plasma lipid concentration or the cholesterolemia prediction (r = 0.83 for FCT and CA).

Adult↗

New aspects of lumbar disc disease. MR imaging and histological findings.

Magnetic resonance imaging (MRI) and plain X-ray and CT studies were performed in patients with a history of lumbar back pain due to spinal disc disease. Spin-echo pulse sequences (SE), phase-contrast techniques (partial saturation sequences with delayed readout, PS), and fat-suppressing inversion recovery sequences (STIR) were employed. In 74 of 325 patients, PS and STIR images displayed vertebral marrow changes adjacent to the end-plates of the affected segments. Bacterial infection, however, could be excluded. In six patients histological diagnosis showed substitution of hematopoietic marrow by fatty tissue, cartilaginous particles, degeneration of fat cells, and an increase in extracellular fluid with different components. The etiology is still unclear, but a correlation with lumbar disc disease is demonstrated. These vertebral marrow changes were best displayed with STIR and phase-contrast MR sequences, both providing contrast changes superior to T2-weighted SE techniques.

Adolescent↗

Effect of long-term olive oil dietary intervention on postprandial triacylglycerol and factor VII metabolism.

Although the beneficial effects of Mediterranean-type diets, which are rich in olive oil, a good source of monounsaturated fatty acids (MUFAs), are generally accepted, little is known about the effects of long-term dietary MUFA intake on postprandial lipoprotein metabolism and hemostasis. This study used a single-blind, randomized, crossover design to investigate the relative effects of a long-term dietary olive oil intervention and a control [saturated fatty acid (SFA)-enriched] diet on postprandial triacylglycerol metabolism and factor VII activity. The postprandial response to a standard test meal was investigated in 23 healthy men who adhered to both diets for 8 wk. cis-MUFAs were successfully substituted for SFAs in the MUFA diet without affecting total dietary fat or energy intakes. The long-term dietary MUFA intervention significantly reduced plasma and LDL-cholesterol concentrations (P = 0.01). Postprandial triacylglycerol concentrations were significantly greater in the early postprandial period after the MUFA diet (P = 0.003). Postprandial factor VII activation and the concentration of the factor VII antigen were significantly lower after the MUFA diet (P = 0.04 and P = 0.006, respectively). This study showed that isoenergetic substitution of MUFAs for SFAs reduces plasma cholesterol and reduces the degree of postprandial factor VII activation. The alterations in the postprandial triacylglycerol response suggest a greater rate of dietary fat absorption and postprandial triacylglycerol metabolism after a diet rich in MUFAs. This study presents new insights into the biochemical basis of the beneficial effects associated with long-term dietary MUFA consumption, which may explain the lower rates of coronary mortality in Mediterranean regions.

Adult↗

Effects of an Ala54Thr polymorphism in the intestinal fatty acid-binding protein on responses to dietary fat in humans.

A polymorphism in FABP2 that results in an alanine-to-threonine substitution at amino acid 54 of the intestinal fatty acid-binding protein (IFABP) is associated with insulin resistance in Pima Indians. In vitro, the threonine form (Thr54) has a higher binding affinity for long-chain fatty acids than does the alanine form (Ala54). We tested whether this polymorphism affected metabolic responses to dietary fat, in vivo. Eighteen healthy Pima Indians, half homozygous for the Thr54 form of IFABP and half homozygous for the Ala54 form, were studied. The groups were matched for sex, age, and body mass index. Plasma triglyceride, nonesterified fatty acid (NEFA), glucose, and insulin responses were measured after a mixed meal (35% of daily energy requirements, 50 g of fat) and after a high fat challenge (1362 kcal, 129 g of fat). NEFA concentrations were approximately 15% higher after the mixed meal and peaked earlier and were approximately 20% higher at 7 h in response to the high fat test meal in Thr54 homozygotes compared with Ala54 homozygotes. Insulin responses to the test meals tended to be higher in Thr54 homozygotes, but glucose and triglyceride responses were not different.The results of this study suggest that the Thr54 form of IFABP is associated with higher and prolonged NEFA responses to dietary fat in vivo. Higher NEFA concentrations may contribute to insulin resistance and hyperinsulinemia in individuals with this allele.

Adipose Tissue↗

Gamma-ray scattering for fat fraction measurement.

The work reported examines the potential of using gamma-ray photon backscatter information to measure in vivo the percentage of fat in specific tissue volumes. 241Am gamma rays are used as the source and the backscatter detected with a hyperpure germanium detector, with ethanol (approximately 80% fat, 20% muscle) and water (muscle) being used as tissue substitutes. Two measurement techniques are examined; the measurement of the ratio of coherent scatter to Compton scatter and the measurement of the Compton scatter profile. Both are shown to be sensitive to the composition difference between ethanol and water. For the coherent-Compton scatter ratio, the measured difference between water and ethanol is 1.85:1, close to the value calculated (about 2:1). A similar difference in the coherent-Compton ratios between muscle and fat is calculated (2.2:1). The FWHM of the Compton profile has also been shown to vary with tissue composition with a difference of 0.10 keV (5%) between the ethanol and water profile widths.

Adipose Tissue↗

Nutrition & health implications of palm oil in Indian diets.

To boost the edible oil production and attain self-sufficiency, one of the long-term strategies undertaken by the Indian government is promotion of palm oil production through oil palm cultivation. Compared to other traditional oils (except coconut oil) used in India, palm oil and palmolein have high saturated fatty acids and low linoleic acid levels. Studies conducted to evaluate the nutritional and health implications of substituting other oils with palmolein show that despite having low linoleic acid, the use of palm oil may not adversely affect the linoleic acid status of Indian population. Substitution of groundnut oil with palmolein in cereal based lactovegetarian diets providing about 30 per cent total fat calories, doubles the saturated fatty acids and reduces by half the linoleic acid content. The effects of this substitution in volunteers from the middle income group did not raise serum cholesterol and aggregability of platelets indicating that palm oil may not produce the deleterious effects associated with saturated fatty acids. The tocols present in palm oil are natural biological antioxidants and can therefore augment the antioxidant potential of Indian diets. Red palm oil is the richest natural source of carotenes which are powerful biological antioxidants. The major carotene in red palm oil is beta-carotene. Therefore, red palm oil can be used to prevent vitamin A deficiency which is widespread in India.

Cholesterol↗

Influence of dietary fats on pancreatic phospholipids of chronically ethanol-treated rats.

Male rats were given liquid diets by pair-feeding for 24-30 days, and phosphatidylinositols in pancreas were analyzed as derivatives of diacylglycerols and fatty acids. Addition of arachidonic acid or changing the fat component (35 energy %) in the liquid diet from olive oil/corn oil to oil from Borago officinalis, which contains 22% gamma-linolenic acid, increased the fraction of arachidonoyl-containing species. This fraction was decreased by more than 50% by substituting ethanol for 36 of the 47 energy% provided by carbohydrate. A smaller difference between ethanol-fed and control rats was seen in the composition of phosphatidylcholines and phosphatidylethanolamines. There was no difference in the composition of phosphatidylinositols when fat, instead of ethanol, was used to substitute the 36 energy % in the diet containing olive oil/corn oil. Substituting ethanol for 28 of 35 energy% provided by fat as corn oil in a liquid diet had no effect on the fraction of arachidonoyl-containing species. The results indicate that the effect of ethanol on phosphatidylinositols in pancreas is not due to a deficiency of arachidonic acid, and that the effect of the ethanol-containing diet is not due to the lowered carbohydrate content. However, high contents of fat or of ethanol appear to be necessary for the effect.

Animals↗

Effect of dietary fish oil on coronary artery and aortic atherosclerosis in African green monkeys.

Studies were carried out for 2.5 to 3 years in adult male African green monkeys (grivet subspecies) fed diets containing 22% of calories as lard or fish oil with 40% of calories as fat and 0.75 mg cholesterol/Kcal to determine if isocaloric substitution of menhaden fish oil for lard affects coronary artery atherosclerosis. The average total plasma cholesterol concentrations during the experimental period were significantly lower for the fish-oil group (231 +/- 37 mg/dl) compared to the lard group (360 +/- 44 mg/dl), but this difference did not become apparent until after 5 months of experimental diet consumption. High density lipoprotein cholesterol concentrations were 30% lower (p less than 0.01) for the fish-oil group also (57 +/- 5 vs. 82 +/- 6 mg/dl). Plasma triglyceride concentrations were low for both groups, but after about 5 months of diet consumption, they were higher for the animals fed fish oil (25 +/- 2 mg/dl) compared to their lard-fed counterparts (15 +/- 1 mg/dl). Coronary artery intimal area (in this case a measure of early atherosclerotic lesion size) was low in all animals but was significantly less (p less than 0.03) for the fish oil vs. lard groups (0.01 +/- 0.002 vs. 0.03 +/- 0.009 mm2). More atherosclerosis was found in other arteries, and a trend was seen of less atherosclerosis in the thoracic aorta and common carotid arteries of the fish-oil group. The size of lesions in the abdominal aorta was similar between diet groups, but microscopic examination of arteries of the lard group revealed relatively more cholesterol monohydrate crystals compared to the arteries of the fish-oil group. Chemical analysis showed that there was less esterified cholesterol (1.46 +/- 0.71 vs. 3.43 +/- 0.74 mg/g, p = 0.04) and free cholesterol (3.7 +/- 2.15 vs. 7.05 +/- 1.68 mg/g, p = 0.08) in the abdominal aortas taken from the animals fed fish oil. There was a significant correlation between low density lipoprotein (LDL) cholesteryl ester (CE) fatty acid ratio (i.e., saturated + monounsaturated/polyunsaturated species) and the amount of esterified (r = 0.59) and free (r = 0.63) cholesterol in the abdominal aortas. Compared to the lard group, animals fed fish oil had significantly lower LDL CE melting temperatures (26 +/- 1 vs. 38 +/- 1 degree C) and significantly smaller LDL particles (2.68 +/- 0.10 vs. 3.25 +/- 0.38 g/mumol). Therefore, the potentially antiatherogenic effects of dietary fish oil include its ability to decrease the concentration, size, CE content, and CE melting temperature of plasma LDL.

Animals↗

Diet, atherosclerosis, and fish oil.

The principal goal of dietary prevention and treatment of atherosclerotic coronary heart disease is the achievement of physiological levels of the plasma total and LDL cholesterol, triglyceride, and VLDL. These goals have been well delineated by the National Cholesterol Education Program of the National Heart, Lung and Blood Institute and the American Heart Association. Dietary treatment is first accomplished by enhancing LDL receptor activity and at the same time depressing liver synthesis of cholesterol and triglyceride. Both dietary cholesterol and saturated fat decrease LDL receptor activity and inhibit the removal of LDL from the plasma by the liver. Saturated fat decreases LDL receptor activity, especially when cholesterol is concurrently present in the diet. The total amount of dietary fat is of importance also. The greater the flux of chylomicron remnants is into the liver, the greater is the influx of cholesterol ester. In addition, factors that affect VLDL and LDL synthesis could be important. These include excessive calories (obesity), which enhance triglyceride and VLDL and hence LDL synthesis. Weight loss and omega-3 fatty acids from fish oil depress synthesis of both VLDL and triglyceride in the liver. The optimal diet for the treatment of children and adults to prevent coronary disease has the following characteristics: cholesterol (100 mg/day), total fat (20% of calories, 6% saturated with the balance from omega-3 and omega-6 polyunsaturated and monounsaturated fat), carbohydrate (65% of calories, two thirds from starch including 11 to 15 gm of soluble fiber), and protein (15% of calories). This low-fat, high-carbohydrate diet can lower the plasma cholesterol 18% to 21%. This diet is also an antithrombotic diet, thrombosis being another major consideration in preventing coronary heart disease. Dietary therapy is the mainstay of the prevention and treatment of coronary heart disease through the control of plasma lipid and lipoprotein levels. The exact place of the omega-3 fatty acids from fish and fish oil remains to be defined. However, this much seems certain. Fish provides an excellent substitute for meat in the diet. Fish is lower in fat, especially saturated fat, and contains the omega-3 fatty acids. Fish oil may have promise as a therapeutic agent in certain hyperlipidemic states, especially the chylomicronemia of type V hyperlipidemia. Fish oil has logical and well-defined antithrombotic and anti-atherosclerotic activities since it depresses thromboxane A2 production and inhibits cellular proliferation responsible for the progression of atherosclerosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

The toxicokinetics and metabolism of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) and their relevance for toxicity.

This article reviews the present state of the art regarding the toxicokinetics and metabolism of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). The absorption, body distribution, and metabolism can vary greatly between species and also may depend on the congener and dose. In biota, the 2,3,7,8-substituted PCDDs and PCDFs are almost exclusively retained in all tissue types, preferably liver and fat. This selective tissue retention and bioaccumulation are caused by a reduced rate of biotransformation and subsequent elimination of congeners with chlorine substitution at the 2,3,7, and 8 positions. 2,3,7,8-Substituted PCDDs and PCDFs also have the greatest toxic and biological activity and affinity for the cytosolic arylhydrocarbon (Ah)-receptor protein. The parent compound is the causal agent for Ah-receptor-mediated toxic and biological effects, with metabolism and subsequent elimination of 2,3,7,8- substituted congeners representing a detoxification process. Congener-specific affinity of PCDDs and PCDFs for the Ah-receptor, the genetic events following receptor binding, and toxicokinetics are factors that contribute to the relative in vivo potency of an individual PCDD or PCDF in a given species. Limited human data indicate that marked species differences exist in the toxicokinetics of these compounds. Thus, human risk assessment for PCDDs and PCDFs needs to consider species-, congener-, and dose-specific toxicokinetic data. In addition, exposure to complex mixtures, including PCBs, has the potential to alter the toxicokinetics of individual compounds. These alterations in toxicokinetics may be involved in some of the nonadditive toxic or biological effects that are observed after exposure to mixtures of PCDDs or PCDFs with PCBs.

Animals↗

Palm and partially hydrogenated soybean oils adversely alter lipoprotein profiles compared with soybean and canola oils in moderately hyperlipidemic subjects.

BACKGROUND: Partially hydrogenated fat has an unfavorable effect on cardiovascular disease risk. Palm oil is a potential substitute because of favorable physical characteristics. OBJECTIVE: We assessed the effect of palm oil on lipoprotein profiles compared with the effects of both partially hydrogenated fat and oils high in monounsaturated or polyunsaturated fatty acids. DESIGN: Fifteen volunteers aged > or =50 y with LDL cholesterol > or =130 mg/dL were provided with food for each of 4 diets (35 d/phase) varying in type of fat (partially hydrogenated soybean, soybean, palm, or canola; two-thirds fat, 20% of energy). Plasma fatty acid profiles, lipids, lipoproteins, apolipoprotein A-I, apolipoprotein B, lipoprotein(a), glucose, insulin, HDL subfractions, and indicators of lipoprotein metabolism (HDL-cholesterol fractional esterification rate, cholesteryl ester transfer protein, phospholipid transfer protein, and paraoxonase activities) were measured at the end of each phase. RESULTS: Plasma fatty acid profiles reflected the main source of dietary fat. Partially hydrogenated soybean and palm oils resulted in higher LDL-cholesterol concentrations than did soybean (12% and 14%, respectively; P < 0.05) and canola (16% and 18%; P < 0.05) oils. Apolipoprotein B (P < 0.05) and A-I (P < 0.05) concentrations mirrored the pattern of LDL- and HDL-cholesterol concentrations, respectively. No significant effect on the total-to-HDL cholesterol ratio was observed for palm oil compared with the other dietary fats. HDL3 cholesterol was higher after palm oil than after partially hydrogenated and soybean oils (P < 0.05). Differences in measures of glucose and HDL intravascular processing attributable to dietary fat were small. CONCLUSION: Palm and partially hydrogenated soybean oils, compared with soybean and canola oils, adversely altered the lipoprotein profile in moderately hyperlipidemic subjects without significantly affecting HDL intravascular processing markers.

Aged↗

Effect of omega-3 fatty acids on the vascular response to angiotensin in normotensive men.

There is a widespread interest in fish oil as a dietary supplement and possible nonpharmacologic adjunct in the treatment of hypertension. The effect of dietary fish oil on blood pressure is controversial and the effect on systemic hemodynamics and regional vascular reactivity in humans is unknown. To address these questions, a double-blind, placebo-controlled, crossover study on the effect of dietary fish oil substitution was performed during a carefully controlled diet in 8 normotensive men. Systemic hemodynamics and the forearm vascular response to intrabrachial artery infusions of norepinephrine, phentolamine and angiotensin II were obtained. Compared with a safflower oil placebo, dietary fish oil had no effect on cardiac output (6.42 +/- 0.38 vs 6.87 +/- 0.28 liters/min, p = not significant) or 24-hour blood pressure (122/68 +/- 3/3 vs 122/68 +/- 3/2 mm Hg, p = not significant). The vascular response to norepinephrine and phentolamine was unchanged. Fish oil, however, significantly (p < 0.05) reduced forearm vascular resistance responses to angiotensin II. These changes were associated with a reduction in plasma triglycerides (64 +/- 9 vs 39 +/- 4 mg/dl, p = 0.02) and an increase in plasma eicosapentaenoic acid levels (0.51 +/- 0.25 vs 1.72 +/- 0.35 microM, p < 0.05). Substitution of a moderate dose of fish oil for fat in a "Western diet" selectively attenuates the vascular response to angiotensin independently of changes in alpha-adrenergic vasoconstriction or systemic hemodynamics.

Adult↗

The effect of diet on bile acid kinetics and biliary lipid secretion in gallstone patients treated with ursodeoxycholic acid.

Effects of specific dietary alterations in patients with radiolucent gallstones treated with ursodeoxycholic acid (UDCA, 750 mg at bedtime) were investigated. Patients were allocated randomly to one of four diets: standard (500 mg cholesterol/day), low-cholesterol (250 mg/day), added-bran (30 g/day), or substituted medium-chain triglycerides (MCT) oil (20% of fat). Dietary intake and good compliance were verified by computerized analysis of dietary diaries. Bile-acid kinetics (26 patients) or secretion of biliary lipids (23 other patients) were determined at enrollment and at 6 and 9 mo, respectively, during treatment. Although MCT further decreased the UDCA-induced decrease in the synthesis of chenodeoxycholic acid, it did not lessen desaturation of bile. Otherwise, compared to the standard diet, no experimental diet significantly altered the UDCA-induced increase of the pools of total bile acids and UDCA or the UDCA-induced decrease in synthesis of bile acids and in biliary secretion or saturation of cholesterol. If these dietary manipulations facilitate dissolution of gallstones by UDCA, they do so by other mechanisms.

Adult↗

Current diagnosis and therapy of parotid tumours.

After reviewing a group of more than 400 patients with parotid tumours, we feel that clinical examination, screening ultrasound scanning and pre-operative CT-scan are our most important diagnostic tools. Our treatment concept is based on direct posterior dissection of the main trunk of the facial nerve, total conservative parotidectomy with ablation of all glandular tissue especially in pleomorphic adenomas so that recurrency can be avoided, intra- and postoperative histological examination and filling in the post-operative soft tissue depression in all cases where intra-operative histological examination excludes malignancy. Primary post-parotidectomy defect substitution techniques using the platysma (Roscic) and the sternocleidomastoid muscle (Rausch) as well as a SMAS- and temporoparietal fascia- or galea-flap are illustrated. We currently use the combination of the Rauch- and Roscic- techniques in a way that a sternocleidomastoideus muscle rotation-flap together with a platysma-SMAS-fat-flap entirely cover the defect. We believe that the substitution-plasty, primarily performed for aesthetic reasons, acts as a mechanical barrier for the misdirected regeneration of the nervs to the skin and the sweat glands, and thus tends to avoid Frey's Syndrome. Using our technique concept, we feel that any disadvantage is counter-balanced by the absence of recurrences, no permanent facial paralysis, relatively good aesthetic results and lower incidence of Frey's Syndrome.

Diagnostic Imaging↗

Nutritional evaluation of wheat-fenugreek blends for product making.

Wheat flour was separately substituted with fenugreek flour (raw, soaked, and germinated) at 5-20% levels for product making. Nutrient analysis of the blends, product development, and their acceptability were carried out. Replacement of wheat flour with fenugreek flour increased the protein, fat, lysine, minerals, and dietary fibre contents proportionately to the level of substitution. Among the composite flours, the blends containing germinated fenugreek flour were found superior in nutritional quality compared to others. However, products, viz., bread, biscuits, noodles, and macaroni prepared from the wheat-fenugreek blends at 10, 15, and 20% levels, were found organoleptically acceptable.

Biological Availability↗

The suitability of cells from different tissues for use in tissue-engineered skin substitutes.

Tissue-engineered skin substitutes may be a future remedy for burn wounds and chronic wounds, as wound contraction and scar formation cannot be prevented with the current standard treatment. The aim of this study therefore was to identify readily available sources of fibroblasts suitable for dermal substitution. Three different tissues were studied: dermal tissue from split-skin graft, subcutaneous fat tissue and eschar tissue obtained through debridement of burn wounds. We determined the cellular profile and the cell numbers immediately after isolation and after 2 and 14 days of fibroblast culture using flow cytometry and cell counting with a cytometer. In addition, parts of the isolated cell suspensions were seeded directly into a porous collagen dermal substitute to investigate contraction over time. Various cell types were isolated from the three different tissues, but after 14 days of culturing predominantly fibroblasts (>90%) were detected. Keratinocytes, granulocytes and macrophages, if present, disappeared within 14 days. In the cell populations derived from dermal tissue, the percentage of myofibroblasts had decreased significantly by day 14 (from 8% to 3%, P=0.028). In contrast, this percentage had increased in the cell populations derived from fat and eschar (from 23% to 40% and from 20% to 38%, respectively). The fibroblast yield from dermal tissue after 2 weeks of culturing (50 x 10(6) cells/g of tissue) was significantly higher than the yield from fat and eschar tissue (2 x 10(6) cells/g of each tissue, P=0.029). Immunohistochemistry of collagen matrices seeded and cultured with fat- and eschar-derived cells revealed a high prevalence of myofibroblasts, whereas hardly any myofibroblasts were detected in the matrices seeded with dermal cells. The contraction of the eschar matrices was highest (74+/-6% remaining area), whereas dermal matrices contracted significantly less (92+/-7% remaining area, P=0.029) with intermediate contraction for fat matrices. We conclude that fibroblast cultures can be established from dermal tissue, fat tissue and eschar tissue. Dermis is the best fibroblast source for use in skin substitutes as it yields the highest numbers of fibroblasts with minimal numbers of myofibroblasts.

Adipose Tissue↗