Immediate breast reconstruction with tissue expansion

Between October of 1983 and June of 1985, 31 patients underwent primary breast reconstruction with tissue expansion. Tissue expansion was utilized for breast reconstruction when the remaining muscle and skin following modified radical mastectomy was insufficient to accommodate a prosthesis that matched in size and shape the opposite breast. All expanders were placed beneath an investing muscular pocket created by elevating the pectoralis major and serratus anterior. Postoperative expansion began within 1 week, and the breast was expanded to double the volume of the opposite breast. Twenty-two patients have completed their reconstruction with a mean follow-up in 7 months. There were nine complications, including five deflations and four infections. All patients have remained Baker I or Baker II. Creating ptosis to match the breast was accomplished by placing the expander below the rectus fascia and superiorly advancing this expanded tissue at the time of prosthesis placement. Primary breast reconstruction with tissue expansion following modified radical mastectomy is safe, simple, and produces a breast with excellent shape, size, texture, and patient satisfaction.     

Supervised reconstruction of biological networks with local models

MOTIVATION: Inference and reconstruction of biological networks from heterogeneous data is currently an active research subject with several important applications in systems biology. The problem has been attacked from many different points of view with varying degrees of success. In particular, predicting new edges with a reasonable false discovery rate is highly demanded for practical applications, but remains extremely challenging due to the sparsity of the networks of interest. RESULTS: While most previous approaches based on the partial knowledge of the network to be inferred build global models to predict new edges over the network, we introduce here a novel method which predicts whether there is an edge from a newly added vertex to each of the vertices of a known network using local models. This involves learning individually a certain subnetwork associated with each vertex of the known network, then using the discovered classification rule associated with only that vertex to predict the edge to the new vertex. Excellent experimental results are shown in the case of metabolic and protein-protein interaction network reconstruction from a variety of genomic data. AVAILABILITY: An implementation of the proposed algorithm is available upon request from the authors.     

Multiscale tissue engineering for liver reconstruction

The liver is a target of in vitro tissue engineering despite its capability to regenerate in vivo. The construction of liver tissues in vitro remains challenging. In this review, conventional 3D cultures of hepatocytes are first discussed. Recent advances in the 3D culturing of liver cells are then summarized in the context of in vitro liver tissue reconstruction at the micro- and macroscales. The application of microfluidics technology to liver tissue engineering has been introduced as a bottom-up approach performed at the microscale, whereas whole-organ bioengineering technology was introduced as a top-down approach performed at the macroscale. Mesoscale approaches are also discussed in considering the integration of micro- and macroscale approaches. Multiple parallel multiscale liver tissue engineering studies are ongoing; however, no tissue-engineered liver that is appropriate for clinical use has yet been realized. The integration of multiscale tissue engineering studies is essential for further understanding of liver reconstruction strategies.     

Breast reconstruction using modified tissue expansion

Inadequate chest-wall skin following mastectomy for carcinoma continues to be a problem in many breast reconstructions. To avoid extensive surgery, serial tissue expansion has been advocated. Since 1977, one of the authors has used a simple method of tissue expansion that we have termed "modified tissue expansion", defined as the creation of an adequate breast mound in one or two stages using a permanent prosthesis. Ninety percent of patients undergoing breast reconstruction between 1978 and 1983 were reconstructed using this method. A retrospective analysis of these 208 patients is presented. There were no mortalities, and only a 6.3 percent complication rate. Skin necroses related directly to the prosthesis occurred once, and there were no prosthetic deflations. Eighteen percent had first-step reconstruction only. The initial prosthesis averaged 400 cc in size. Selected Halsted radical mastectomy and postradiotherapy patients were successfully reconstructed. Seventy-eight percent felt their results were excellent at 1 year. Two percent were dissatisfied. Multiple office visits and the potential problems of serial expansion were avoided. Modified tissue expansion is a simple and viable method and should be considered among the options for breast reconstruction following mastectomy.     

Multiscale tissue engineering for liver reconstruction

The liver is a target of in vitro tissue engineering despite its capability to regenerate in vivo. The construction of liver tissues in vitro remains challenging. In this review, conventional 3D cultures of hepatocytes are first discussed. Recent advances in the 3D culturing of liver cells are then summarized in the context of in vitro liver tissue reconstruction at the micro- and macroscales. The application of microfluidics technology to liver tissue engineering has been introduced as a bottom-up approach performed at the microscale, whereas whole-organ bioengineering technology was introduced as a top-down approach performed at the macroscale. Mesoscale approaches are also discussed in considering the integration of micro- and macroscale approaches. Multiple parallel multiscale liver tissue engineering studies are ongoing; however, no tissue-engineered liver that is appropriate for clinical use has yet been realized. The integration of multiscale tissue engineering studies is essential for further understanding of liver reconstruction strategies.     

The relative importance of local phase and local amplitude in patchwise image reconstruction

Natural images were subjected to patchwise Fourier analysis, and the local amplitude and phase spectra were swapped between different images. When the patches were large relative to the image size, the appearance of the reconstructed image was similar to that of the image from which the phase information had been derived, in agreement with previous reports of phase-dominance in the global Fourier Transform. However, when the patch size was made sufficiently small, the appearance of reconstructed images was dominated by amplitude rather than phase. This was not simply due to the DC component of the amplitude spectrum. Prior low-pass filtering of the images enhanced the dominance of amplitude information in the patchwise transform. We conclude that patchwise-reconstructed images contain two quite distinct kinds of information for the human observer. The first is the positional information (local sign) of the patches themselves; the second is the textural information within patches, which is dominated by amplitude rather than phase. The reason why the global Fourier Transform is dominated by phase is that in the absence of any other information about local sign, phase is necessary to reconstruct localised features such as edges.     

Double-paddle peroneal tissue transfer for oromandibular reconstruction

The double-paddle peroneal tissue transfer is a useful technique for reconstructing the extensive and complex defect that results after ablative surgery for oral cancer. It can facilitate the design and inset of the skin paddle and avoid the need for a second free flap. The two skin paddles can be based on either two cutaneous perforators of the peroneal vessels or two branches of a single cutaneous perforator. The authors report their experience with double-paddle peroneal tissue flaps (10 fasciocutaneous and five osteocutaneous) in 15 patients. The largest double paddle used was (16 x 9) (15 x 6) cm, and the smallest one was (7 x 5.5) (4.5 x 4) cm. All flaps were used for both intraoral and extraoral defect reconstruction. There was one single skin paddle necrosis caused by erroneous manipulation of the flap 1 week after the operation; however, the skin paddle had survived completely before the manipulation. All other flaps survived completely, with a good to excellent appearance, and no patient had a significant gait disturbance after the operation.     

Generation of a bioartificial fibromuscular tissue with autoregenerative capacities for surgical reconstruction

INTRODUCTION: Anecdotal clinical reports denote first tissue engineering applications entering medical practice. Currently it is still unknown, if these new types of implants will tolerate the specific needs in cancer patients undergoing postoperative chemo- and radiotherapy. METHODS: We implemented a radiotherapy protocol (cumulative dosis 40 Gy) on generated human bioartificial fibromuscular tissues in vitro. We monitored tissue vitality during radiotherapy and tissue recovery (8 weeks follow up period) applying histological methods. RESULTS: The biopsy procedure and seeding techniques yielded a viable 3 dimensional bioartificial human tissue. Radiation resulted in immediate devitalization without destroying tissue integrity. The bioartificial tissue recovered entirely in vitro within 6 weeks. CONCLUSION: Bioartificial human implants appear applicable for surgical reconstruction in oncologic patients potentially facing postoperative radiotherapy.