Selecting a free flap for soft tissue coverage in lower extremity reconstruction.

BACKGROUND: Goals of lower extremity microvascular reconstruction (LEMR) include the restoration of function, prevention of infection, and optimal cosmesis. Indications for LEMR include large defects that are not amenable to pedicled options, a large zone of injury, and large complex defects. The novice microsurgeon should first master a handful of free flaps to develop an armamentarium of options for addressing such defects. The scope of this review is to provide free flap options for LEMR in any of the thirds of the lower leg. After reading this article, the reader will understand variations, advantages, disadvantages, indications, and tips for raising each of these flaps. METHODS: Six most commonly used free flaps for LEMR are described in this paper, including the anterolateral thigh flap (ALT) and its variations, the radial forearm flap (RFFF), the lateral arm flap (LAF), the gracilis muscle flap, the rectus abdominis flap (RAF) and the latissimus dorsi flap and its variations. Indications, advantages, disadvantages and technique tips are discussed for each flap. Moreover, selection of the recipient vessels, preoperative management along with an algorithm are also provided. CONCLUSIONS: The ALT flap is a workhorse in covering defects of the leg, foot, and ankle. It's the flap of choice at our institution, especially given the number of traumatic wounds seen as a result of motor vehicles, all-terrain vehicles (ATV), lawnmowers, and gunshot wounds (GSW). At times, the lower extremity zone of injury requires a distant donor site. The RAF can also provide coverage for large soft tissue defects but donor-site morbidity remains its main drawback. The LAF and RFFF provide two pliable options, one that provides pliable soft tissue with minimal donor site morbidity and another that provides a long pedicle. The free gracilis flap is an excellent choice for crossing the ankle joint. Lastly, the free latissimus dorsi is indicated for large defects of the lower extremity independently of the location.

Microvascular reconstruction of pediatric lower extremity trauma using free tissue transfer.

While free tissue transfer has long been established as a reliable microsurgical technique in the adult population, its application in pediatric reconstruction is a relatively recent phenomenon. Despite initial concerns regarding minute vessel diameters, increased propensity for vasospasm, and limited tissue availability, pediatric free tissue transfer is now a widely used technique that has demonstrated an acceptable level of donor and recipient site morbidity in children. Five flaps commonly used in the reconstruction of lower extremity trauma are discussed in this paper: the latissimus dorsi, rectus abdominis, anterolateral thigh, gracilis, and the subscapular and parascapular flaps. The indications, blood supply, advantages, and disadvantages of each are detailed. Incredible progress has been made in the application of microsurgical techniques to the pediatric population over the last several decades. With a healthy understanding of the anatomy and functionality of the donor site, the reconstructive surgeon can repair a variety of complex injuries with an acceptable morbidity and mortality rate.

Can anthropometric measurements and diet analysis serve as useful tools to determine risk factors for insulin-resistant diabetes type 2 among white and black Americans?

OBJECTIVE: Central obesity is implicated in the development of insulin resistance by increasing insulin demand and eventually leading to hyperinsulinemia. Anthropometric measurements have been helpful in determining the risk factors in developing diabetes mellitus type 2. In this study we investigated whether anthropometric measurements differ among diabetics of different races. We also evaluated whether nutrient intake of these individuals was related to anthropometric measurement changes. METHODS: Subjects were recruited from four groups: white control (n = 10), black control (n = 10), white diabetic (n = 5), and black diabetic (n = 10). The diabetic subjects had type 2 diabetes with insulin resistance on insulin monotherapy (age and sex matched). The following determinations were made: diet analysis, body mass index (kg/m(2)), the ratio of waist (umbilical level) to hip (maximum at buttocks) circumference, the ratio of waist to thigh (mid-thigh), and body fat percentage. RESULTS: The micronutrient consumption was fairly similar in all groups with the exception of vitamin A (greatest consumption in the white control group, P < 0.05; and the lowest consumption in the black control group, P < 0.05). The data also suggested that central obesity (greatest waist-to-hip ratio) was present in the individuals with type 2 diabetes. The higher total fat, including saturated, monounsaturated, polyunsaturated, and cholesterol, intake in the diabetic groups were observed. CONCLUSION: The type of fat consumed may be as important as the total fat consumption in the development of insulin resistance. The diet analysis can provide valuable information about the dietary habits of an individual and the possible causes of metabolic problems leading to a disease state. However, genetic factors must be considered when looking at diabetes incidence in different ethnic groups. For example, even though the black diabetic group consumed less fat in comparison with the other groups, their body fat percentages were higher. Therefore, we cannot conclude that high fat intake is primarily responsible for increased body fat percentage. Although anthropometric measurements are a useful tool in risk assessment, researchers should consider anatomic differences among different racial groups as covariables. Diet analysis when used in conjunction with anthropometric measurements can serve as a useful tool to detect whether metabolic alterations are related to dietary habits.

Antioxidant properties of evening primrose seed extracts.

The antioxidant activity of extracts of evening primrose seeds (SE) and a commercially extracted filter cake (FC) were determined. The SE and FC were extracted with methanol/water (9:1) followed by evaporation and concentration. Extracts were tested in a bulk oil system and an oil-in-water emulsion using safflower oil as the major source of lipids. The antioxidant activity of the extracts was compared to that of a control and to that of butylated hydroxytoluene (BHT), singly, and in combination. Antioxidant activity was measured by the co-oxidation of beta-carotene, an oxidative stability instrument, conjugated dienes, and headspace analysis of hexanal. The SE extract had greater antioxidant activity than the FC extract. The SE extract was more effective in controlling the oxidation in the oil-in-water model system than in the bulk oil system. The activity of SE was concentration dependent, and at higher concentrations the SE was as effective as BHT, but it required higher concentrations because of its lack of purity. Synergism between SE and BHT was demonstrated in both model systems.

The effect of ethoxyquin on the quality of ground poultry mortality carcasses preserved by lactic acid fermentation and phosphoric acid stabilization.

Fermentation and acidification have been shown to preserve the protein quality of ground poultry coproducts, but the effects of these processes on their lipid stability are unknown, especially in the presence of an antioxidant. To evaluate the effects of these treatments on lipid quality, ground poultry mortality carcasses, with and without an addition of 500 ppm ethoxyquin, were stabilized for 14 and 45 d by lactic acid fermentation or acidification with 2.76, 5.07, 7.35, or 9.65% feed-grade H3PO4. Ethoxyquin treatment significantly (P < 0.001) improved the oxidative stability of lipids from all storage treatments. However, the addition of ethoxyquin increased (P < 0.001) the levels of volatile N (VN) from 2.51 to 3.18% in products stored for 45 d and resulted in an increase (P < 0.001) in free fatty acids in all ensiled products. Ethoxyquin addition had no effect (P > 0.120) on the fatty acid profile of products stored for 14 d but significantly increased (P < 0.001) the levels of stearic (C18:0) and arachidonic acids (C20:4) in products stored for 45 d. In this experiment, the addition of ethoxyquin to preservation systems for the short-term storage of poultry mortality carcasses improved the lipid quality of the ground material without compromising the protein quality or affecting proximate analysis parameters. However, the increased oxidative stability of mortality silage materials that contain ethoxyquin may contribute to enhanced microbial or enzymatic activities that result in proteolytic or lypolytic breakdown products following longer periods of storage.

Characterization of methanol-soluble and methanol-insoluble proteins from developing peanut seed.

The 85% methanol-soluble proteins are known to specifically contribute to the production of flavor of roasted peanut. To determine the nature of the 85% methanol-soluble proteins, they were isolated from the peanut seed, and the 85% methanol-soluble (MS) and 85% methanol-insoluble (MIS) fractions were characterized using polyacrylamide gel electrophoresis (PAGE) and capillary electrophoresis. The results showed that the 85% MS fraction contained lower amounts (9-10%) of protein than the MIS fraction (15-33%). Protein content of the MIS fraction increased more significantly during seed maturation than it did in the MS fraction. Unlike the protein, free amino acids and soluble sugars levels of the MS fraction decreased significantly during seed maturation. The 85% MS fraction contained predominantly low molecular weight (<20 kDa) proteins/polypeptides, whereas the MIS fraction contained a mixture of polypeptides with molecular weight between 14 kDa and 90 kDa. SDS-PAGE showed no major changes in the polypeptide composition of the MS fraction during seed maturation. Capillary electrophoretic analysis revealed major qualitative and quantitative changes in the protein and polypeptide composition of the MS and MIS fractions during seed maturation. Fatty acid analysis of these fractions indicated that the MS fraction is lipoprotein in nature and rich in oleic and linoleic acids.

Isolation and characterization of whey phospholipids.

A freeze-dried whey powder was produced by microfiltration of Cheddar cheese whey. A 0.2-micron ceramic membrane in a stainless steel housing unit was used to concentrate components > 400 kDa present in the whey. The experimental whey powder, derived from Cheddar cheese whey, and a commercial whey powder were subjected to proximate analysis, lipid classes, phospholipid classes, and fatty acid compositional analyses. Commercial whey powder and commercial soybean lecithin were subjected to an alcohol fractionation procedure in an effort to alter the ratio of phosphatidyl choline to phosphatidyl ethanolamine and the functionality of dairy phospholipids. The fractionation procedure produced an alcohol-insoluble fraction containing 84% phosphatidyl ethanolamine, whereas the alcohol-soluble fraction resulted in a decrease in the phosphatidyl choline to phosphatidyl ethanolamine ratio. The commercial whey contained a higher ratio of phospholipids to neutral lipids compared with the experimental whey. The classes of phospholipids present within the two wheys were similar, whereas the experimental whey contained a phosphatidyl choline content twice that of the commercial whey, and the phospholipids composition of both wheys differed from the milk fat globule membrane. Comparison of the phospholipids and fatty acid composition of the wheys with the soy lecithin revealed that although the wheys were similar to each other, they differed from the soy lecithin in both the classes of phospholipids present and in the fatty acid composition. These compositional differences may influence the functionality of whey phospholipids.

Pyomyositis in an HIV-positive premature infant: case report and review of the literature.

Pyomyositis is a purulent infection of skeletal muscle caused predominantly by Staphylococcus aureus. Although not often encountered in the continental United States, pyomyositis is frequently seen in tropical areas. Pyomyositis is difficult to diagnose as it may mimic other diseases. Delay in diagnosis may lead to septicemia, shock, and death. Recently, two cases of patients with pyomyositis and acquired immune deficiency syndrome were reported. We report a case of pyomyositis in a 7-week-old premature infant who subsequently tested positive for anti-HIV antibodies. A brief review of the topic is included.

Analysis of positional isomers of monounsaturated fatty acids by high performance liquid chromatography of 2,4-dinitrophenylhydrazones of reduced ozonides.

A method is described for quantifying the positional isomers in monounsaturated fatty acid methyl ester (FAME) fractions. The procedure involves the preparation of 2,4-dinitrophenylhydrazones (DNPH) of the fragments generated during reductive ozonolysis of FAME, class isolation of the aldehyde and aldehyde ester DNPH, and separation of the aldehyde ester derivatives by high performance liquid chromatography (HPLC). The high extinction coefficient of the DNPH provides for a sensitive assay which is linear for a large range of components over a concentration range of 0.075-5 nmol/component, and the stability of the DNPH permits the independent analysis of the aldehyde and aldehyde ester fragments generated during reductive ozonolysis. The reductive ozonolysis-DNPH-HPLC method developed is as sensitive, reproducible, and accurate as reductive ozonolysis-gas-liquid chromatography and does not suffer from some of the drawbacks of the classical procedure.