Genetically modified fibroblasts induce angiogenesis in the rat epigastric island flap

Methods: Gene therapy was tested for inducing functional angiogenesis in the superficial rat epigastric island flap to allow earlier pedicle division. Autologous rat fibroblasts were grown, harvested, cultured and retrovirally transfected to produce platelet-derived growth factor AA (PDGF-AA), an angiogenetically active protein. Stable gene expression was monitored by PDGF-AA enzyme-linked immunosorbent assay (ELISA). One hundred and eighty animals were divided into three groups (I–III) and a bilateral flap created in each animal. In all experiments, the right-sided flap was subjected to experimental treatment and the left-sided flap served as control (1 ml saline 0.9%). During flap elevation, group I received 5×10⁶ GMFB (genetically modified fibroblasts) plus 1 ml Dul-becco's modified Eagle's medium. Group II was treated with 5×10⁶ NMFB (non-modified fibroblasts) plus 1 ml medium and group III received 1 ml medium only. The flaps were sutured back and the vascular pedicle was bilaterally ligated and divided in each of ten animals during the following 6 days. After 7 days, the flaps were harvested, the amount of necrosis measured and histologically examined. Results: The GMFB produced up to 560 times more PDGF-AA than the NMFB, measured by ELISA. The GMFB-treated flaps tolerated surgical division of the vascular pedicle significantly earlier than groups II and III. Histologically, fibroblasts persisted in all flaps of groups I and II, without major inflammatory reaction. In all GMFB-treated flaps, massive angiogenesis could be demonstrated. Conclusion: By means of retroviral gene transfer, autologous rat fibroblasts can be genetically modified for stable expression of the PDGF-A gene to produce high amounts of PDGF-AA, which is angiogenetically active. After injection into the panniculus carnosus, these cells induce functional angiogenesis to permit earlier division of the vascular pedicle in this flap model. Received: 5 January 1998 / Accepted: 17 June 1998     

Reconstruction of plantar defects

Plantar defects are a challenge for the plastic surgeon; from 1984–1995 59 operations were performed in 57 patients. The radial forearm flap and the latissimus dorsi (LD) flaps were mainly used depending on the amount of tissue loss. Local flaps such as dorsalis pedis and instep flaps were used for smaller defects. The radial forearm flap is ideal in terms of thickness and stability for the sole but limited in its size. The LD flap is a safe procedure especially for severe injuries and osteitis, but has the disadvantage of being bulky and debulking procedures are frequently performed. For nerve reconstruction deep sensibility seems to be sufficient in order to obtain stable postoperative results. In this report the different operative methods are evaluated. Since 1991, the patients were monitored with static and dynamic foot pressure measurements and gait analysis to assess the postoperative result and prevent pressure ulcers, scar irritation and hyperkeratosis. Preoperative investigations may contribute to an optimal schedule for planning and stabilization of the operative regimen.     

Lymphoscintigraphy as a predictor of lymphatic drainage from cutaneous melanoma

Background: If cutaneous lymphoscintigraphy (CL) is accurate in predicting the draining lymph node basins at risk from primary axial melanomas, then regional metastases should only occur in those lymph node basins identified by CL. Methods: This study is a retrospective review of patients undergoing CL for primary axial melanomas from June 1, 1985, until June 31, 1992. Data retrieved included age, gender, number of basins identified, location of basins identified, management of basins, recurrence in lymphatics, development of distant disease, and long-term follow-up. Results: A total of 181 patients underwent elective LND, and 48 patients (27%) had melanoma in the nodes within the dissected basin. Of these 181 patients, seven developed nodal metastases as their site of first recurrence. All seven recurrences were seen at sites dissected or at sites indicated by CL, which the primary surgeon elected not to treat initially. Of the 116 patients observed, 16 (14%) developed lymph node metastases as their first site of recurrence. Fifteen of these 16 patients had their site of lymph node metastases predicted by CL. In this study, CL predicted 98.6% of all lymph node metastases. Conclusions: The high overall reliability of CL as demonstrated by long-term follow-up indicates that the information obtained by CL can be reliably used to guide intervention. Initial evaluation of patients with high-risk cutaneous melanomas at sites with ambiguous lymphatic drainage must include CL in order to determine the draining lymph node basins and to plan therapy. Presented at the 47th Annual Cancer Symposium of The Society of Surgical Oncology, Houston, Texas, March 17–20, 1994.     

A survey of pre-placement urinalysis drug findings.

In December, 1989, the Department of Transportation (DOT) in conjunction with the Federal Aviation Administration (FAA) mandated an extensive urine drug testing program for selected positions within the airline industry. At the end of 1 year we have tested 7,872 applicants under these rules, with a positive finding rate of 0.17%. We have also tested 32,157 applicants, including those applying for DOT-covered positions, with a positive rate of 2.82%. Considering only the two major drugs of abuse--marijuana and cocaine--we found the positive rate to be an order of magnitude greater than the rate discovered under the DOT program. We present these data together with a discussion of some of the possible reasons for this major disparity. We also present findings for barbiturates and benzodiazepines which are not tested under the DOT program, but which have safety implications related to the aviation industry.     

Fluorescence immunohistochemistry and confocal scanning laser microscopy

We have developed a reliable technique for labeling and examining neural structures in soft tissues associated with articular joints and have tested it in human wrist joints under various specimen-related conditions. The labeling protocol employs an immunohistochemical process with a panneuronal marker (PGP 9.5) as the primary antibody and Alexa Fluor 488 as the fluorescing secondary antibody. Imaging was done using a confocal laser scanning microscope, which produced exceptionally detailed three-dimensional images of nerve endings and transiting nerve fibers from thick sections of wrist joint ligaments obtained from human cadavers. The protocol provided a practical postmortem window for specimen acquisition and processing without significant apparent worsening of image quality. The images produced are resistant to fading with repeated exposure to a fluorescent light source, which gives many opportunities for observation. Background staining is minimal, producing high contrast labeling of target tissues, which, in turn, enhances image analysis.     

Assessment of immunization as a technique to extend the chilled storage life of vacuum‐packaged lamb

The growth at — 1.5°C of Lactobacillus delbrueckii, a meat spoilage organism, was evaluated on vacuum‐packaged lamb legs obtained from animals immunized against that organism. Growth was significantly lower than that on similarly treated legs obtained from non‐immunized lambs. These findings suggest that immunization against spoilage organisms may contribute toward increasing the chilled storage life of fresh meat.     

Pneumococcaemia as a presenting sign in 3 cases of multiple myeloma

Multiple myeloma was diagnosed in 3 patients following episodes of pneumococcaemia associated with neutropenia and decreased serum concentration of normal immunoglobulins. Severe pneumococcal infection is commonly encountered during the course of multiple myeloma, but has not been stressed as a presenting feature of the disease.