Breast reconstruction following lumpectomy and irradiation

The traditional approach to breast cancer has been the surgical mastectomy. The cosmetic deformity resulting from this procedure has led to the development of our current methods of breast reconstruction. The inherent attraction of lumpectomy and radiotherapy has been its equation with improved cosmesis. This procedure may be an effective alternative to surgery from the cancer perspective and does produce, in the majority of patients, an acceptable cosmetic result. However, this paper demonstrates that it may produce a result that is less optimal than mastectomy with postoperative breast reconstruction. The etiology of the increased deformity can either be the localized lumpectomy with marked internal derangement of breast volume or the radiation therapy itself. In addition, those who develop a combination require a solution to both. We describe three patients who illustrate these problems and believe that a greater awareness of these potential complications should be available to aid patients in choosing their cancer treatment.     

A new technique of scarless expanded forehead flap for reconstructive surgery

The forehead flap is an ideal flap for reconstructive surgery, especially for that involving reconstruction of the face and neck. However, it is usually limited to use in nasal reconstruction, even when performed in conjunction with tissue expansion, because of the severe visible morbidity of the donor site. In this article, the author discusses his development of a new technique of forehead flap, performed in conjunction with tissue expansion, for reconstructive surgery without visible scarring at the donor site. The technique involved positioning a tissue expander in the forehead pocket under the occipitofrontal muscle and serially inflating the expander over a period of approximately 4 to 6 weeks. Thereafter, an expanded forehead flap was created from the frontal hairline area on the basis of the location of the superficial temporal vessels and transferred into 16 recipient sites in 13 patients as an island flap (n = 8), a free flap (n = 1), or a local random flap (n = 7). The donor site was closed directly into the frontal hairline, without any visible scar. With the author's experience in the use of the island flap for nasal, facial, and neck reconstruction and of the free flap for reconstruction in the extremities, the flap could be as large as 8 x 18 cm without inducing flap necrosis or problems with donor-site closure. All patients (n = 13) had acceptable donor-site aesthetic results, without visible scarring. The results indicate that the flap could be a safe, ample, and color-matched flap for reconstruction of the face and neck and could also diminish donor-site morbidity to a minimum, without an unsightly visible scar. Furthermore, the flap could be formed into a customized free flap, with the above-mentioned advantages, to be transferred to any part of the body.     

A novel technique for viable cell determinations

We have developed a simple method to determine cell viability using two fluorescent dyes, Hoechst 33258 and acridine orange. When these dyes are used in combination, dead cells fluoresce brilliant blue and live cells fluoresce green. This method works over a range of dye concentrations (Hoechst 33258, 0.25-2 micrograms/ml; acridine orange, 1-5.0 micrograms/ml) and the fluorescence spectra of the two dyes are such that only one set of filters is required to visualize the effects of both dyes simultaneously. It is insensitive to a wide range of exogenous serum concentrations and is read with greater uniformity by different observers.     

A novel technique for efficient multiple sample dialysis

Conventional methods for dialyzing numerous samples are either expensive or tedious and inefficient. These disadvantages were overcome through the construction and use of a Plexiglas dialysis sample holder (DSH). Large numbers of dialysis samples having 0.5 to 2.0-ml volumes may be attached to numbered positions on the DSH. Sample identification is greatly simplified and considerable savings in time and material are achieved. Furthermore, the risk of sample spill or mixing during filling or emptying of dialysis sacks, and the risk of leaks in dialysis tubing, are minimized.     

A novel technique for measurement of pericardial pressure

To determine whether pericardial liquid pressure accurately measures pericardial constraint, we developed a technique in which a catheter was positioned perpendicular to the epicardial surface. This device, which occupies little or no pericardial space, couples the thin film of liquid to a transducer. In six open-chest dogs, we also measured left ventricular (LV) end-diastolic pressure (LVEDP) and anteroposterior and septum-to-free wall diameters. LVEDP was raised incrementally to approximately 25 mmHg by saline infusion. With the use of the product of the two diameters as an index of area (A(LV)), LVEDP-A(LV) relationships were obtained with the pericardium closed and again after the pericardium had been widely opened to obtain the isovolumic difference in LVEDP (DeltaLVEDP). In all dogs, the technique yielded values of pericardial pressure equal to DeltaLVEDP as well as equal to that measured using a previously placed balloon transducer in the same location and at the same A(LV). We conclude that, when the pressure of the pericardial liquid is appropriately measured, it (in addition to the balloon-measured contact stress) defines the diastolic constraining effect of the pericardium. Furthermore, we suggest that earlier measurements of pericardial "liquid pressure" were low, due to an artifact of measurement.     

A novel technique to overcome browning in tissue culture

Experiments conducted using Dioscorea alata L. revealed that an exudate from the cut end of the explants was responsible for browning of the culture medium. Browning did not affect growth of roots and shoots when explants were cultured in a large volume of medium, but in a small volume it was lethal. Sealing the cut ends with paraffin wax was found to control browning by preventing exudation. This simple technique permitted establishment of cultures in a small volume of medium in about 90 percent of the cases, while in unsealed cultures lethal browning was recorded in 80 percent of the cases. The advantages of this technique over other methods of controlling browning are discussed.     

Crystallo-co-agglomeration: A novel technique to obtain ibuprofen-paracetamol agglomerates

The purpose of this research was to obtain directly compressible agglomerates of ibuprofen-paracetamol containing a desired ratio of drugs using a crystallo-co-agglomeration technique. Crystallo-co-agglomeration is an extension of the spherical crystallization technique, which enables simultaneous crystallization and agglomeration of 2 or more drugs or crystallization of a drug and its simultaneous agglomeration with another drug or excipient. Dichloromethane (DCM)-water system containing polyethylene glycol (PEG) 6000, polyvinyl pyrollidone, and ethylcellulose was used as the crystallization system. DCM acted as a good solvent for ibuprofen and bridging liquid for agglomeration. The process was performed at pH 5, considering the low solubility of ibuprofen and the stability of paracetamol. Loss of paracetamol was reduced by maintaining a low process temperature and by the addition of dextrose as a solubility suppressant. The agglomerates were characterized by differential scanning calorimetry, powder x-ray diffraction (PXRD), and scanning electron microscopy and were evaluated for tableting properties. The spherical agglomerates contained an ibuprofen-paracetamol ratio in the range of 1.23 to 1.36. Micromeritic, mechanical, and compressional properties of the agglomerates were affected by incorporated polymer. The PXRD data showed reduction in intensities owing to dilution and reduced crystallinity. Thermal data showed interaction between components at higher temperature. Ethylcellulose imparted mechanical strength to the agglomerates as well as compacts. The agglomerates containing PEG have better comparessibility but drug release in the initial stages was affected owing to asperity melting, yielding harder compacts. The agglomeration and properties of agglomerates were influenced by the nature of polymer.     

A novel piezoelectric immunoagglutination assay technique with antibody-modified liposome

A simple rapid piezoelectric immunoagglutination assay (PEIA) technique with antibody-modified liposome has been developed for direct quantitative detection of human immunoglobulin G (hIgG). This technique is based on specific agglutination of antibody-coated liposome particles in the presence of the corresponding antigen, which can be monitored by the frequency shift of a piezoelectric device. Compared with conventional piezoelectric assays, this liposome-based PEIA does not require the immobilization of antigen or antibody on the quartz crystal surface, making the developed technique especially useful for rapid and renewable immunochemical determination. To alleviate non-specific adsorption of serum proteins, modification of the quartz crystal surface by different protocols and the composition of the assay medium have been investigated. The results indicate that the background interference can be substantially minimized through modifying the quartz crystal surface with a bovine serum albumin (BSA) layer and introducing an appropriate amount of BSA in the assay medium. The effects of the liposome composition, the liposome concentration and the concentration of poly(ethylene glycol) (PEG) in the assay medium, have also been investigated. The frequency responses of the liposome-based PEIA are linearly correlated to hIgG concentration in the range of 0.05-6 microg mL(-1) with a detection limit of 50 ng mL(-1).     

A novel phytoplankton chlorophyll technique: toward automated analysis

Interest in the <1 µm picoplankton fraction of naturalwaters, especially the oligotrophic oceans, has generated atrend toward the use of smaller and smaller porosity membranefilters for particulate analyses. The controversy concerningthe suitability of glass fiber versus membrane filters for retainingchlorophyll-containing parlicles is re-examined and the inadequaciesof filtration discussed. Previous comparisons in the literaturefail to resolve this controversy as tests were performed inwaters of >1.0 µm/l chlorophyll. A novel phytoplanktonchlorophyll technique for fresh and marine waters is describedwhich eliminates the need to concentrate plankton on filters.Two commercially available instruments have been modified topermit fluorescence measurements of whole water extracts. Thelower limit of detection is 0.1 µg/l in situ concentrationor 0.02 µg/l extract concentration. The technique lendsitself well to automation with particular applications to insitu fluorometry, flow cytometry and continuous chlorophylldeterminations. ^*This paper is the result of a study made at the Group for AquaticPrimary Productivity (GAP), Second International Workshop heldat the National Oceanographic Institute, Haifa, Israel in April–May1984.     

Decellularized omentum as novel biologic scaffold for reconstructive surgery and regenerative medicine

Homologous tissues, such as adipose tissue, may be an interesting source of acellular scaffolds, maintaining a complex physiological three-dimensional (3D) structure, to be recellularized with autologous cells. The aim of the present work is to evaluate the possibility of obtaining homologous acellular scaffolds from decellularization of the omentum, which is known to have a complex vascular network. Adult rat and human omenta were treated with an adapted decellularization protocol involving mechanical rupture (freeze-thaw cycles), enzymatic digestion (trypsin, lipase, deoxyribonuclease, ribonuclease) and lipid extraction (2-propanol). Histological staining confirmed the effectiveness of decellularization, resulting in cell-free scaffolds with no residual cells in the matrix. The complex 3D networks of collagen (azan-Mallory), elastic fibers (Van Gieson), reticular fibers and glycosaminoglycans (PAS) were maintained, whereas Oil Red and Sudan stains showed the loss of lipids in the decellularized tissue. The vascular structures in the tissue were still visible, with preservation of collagen and elastic wall components and loss of endothelial (anti-CD31 and -CD34 immunohistochemistry) and smooth muscle (anti-alpha smooth muscle actin) cells. Fat-rich and well vascularized omental tissue may be decellularized to obtain complex 3D scaffolds preserving tissue architecture potentially suitable for recellularization. Further analyses are necessary to verify the possibility of recolonization of the scaffold by adipose-derived stem cells in vitro and then in vivo after re implantation, as already known for homologus implants in regenerative processes.Key words: omentum, scaffold, decellularization, adipose tissue engineering, regenerative medicine, microvascularization