C.S. Sobral

Proliferation of fibroblasts cultured on a hemi-cellulose dressing

In recent times, hemi-cellulose dressing (HD) has been used clinically with satisfactory rates of success [Melandri D, De Angelis A, Orioli R, et-al. Use of a new hemicellulose dressing (Veloderm) for the treatment of split-thickness skin graft donor sites A within-patient controlled study. Burns 2006 Dec;32:964-72.]; however, the effect of cellulose dressings on the wound-healing process is unclear due to paucity of experimental data. This study aimed to determine the adhesion and proliferation of human skin fibroblasts, which were cultured in vitro using the explant technique, on HD. Cells were seeded onto HD discs and evaluated for cell adhesion and cell proliferation after 7, 14 and 21 days. Fibroblasts displayed 70% adhesion to HD after 24h. The HD discs seeded with a density of 5x10(4) cells per well showed a proliferation rate of 12% on day 7, 30% on day 14 and 75% on day 21. The results demonstrated that HD can sustain fibroblast proliferation--a highly desirable characteristic for an ideal skin substitute.

Thermolysin in human cultured keratinocyte isolation

BACKGROUND When treating extensively burned patients using cultured epidermal sheets, the main problem is the time required for its production. Conventional keratinocyte isolation is usually done using Trypsin. We used a modification of the conventional isolation method in order to improve this process and increase the number of colonies from the isolated epidermal cell population. PURPOSE To compare the action of trypsin and thermolysin in the keratinocyte isolation using newborn foreskin. METHODS This method used thermolysin as it selectively digests the dermo-epidermal junction. After dermis separation, the epidermis was digested by trypsin in order to obtain a cell suspension. RESULTS Compared to the conventional procedure, these experiments demonstrated that in the thermolysin group, the epidermis was easily detached from the dermis, there was no fibroblast contamination and there were a larger number of keratinocyte colonies which had a significant statistical difference. CONCLUSION The number of colonies in the thermolysin group was significantly greater than in the trypsin group.

Dimethylaminoethanol affects the viability of human cultured fibroblasts.

BackgroundIn clinical practice, dimethylaminoethanol (DMAE) has been used in the fight against wrinkles and flaccidity in the cervicofacial region. The firming action of DMAE is explained by the fact that its molecule, considered to be a precursor of acetylcholine, alters muscle contraction. However, no experimental studies have confirmed this theory. Because the actual mechanism of DMAE action was not defined and there were no references in the literature regarding its direct action on fibroblasts, this study was performed to evaluate the direct action of DMAE on cultured human fibroblasts.MethodsHuman fibroblasts obtained from discarded fragments of total skin from patients undergoing plastic or reconstructive surgical procedures performed within the Plastic Surgery Division at the Federal University of São Paulo were used for this study. The explant technique was used. The culture medium was supplemented with different concentrations of DMAE on the fourth cell passage, and the cell proliferation rate, cytosolic calcium levels, and cell cycle were evaluated. Statistical analysis was performed using analysis of variance (ANOVA) followed by a Newman-Keuls test for multiple comparisons.ResultsA decrease in fibroblast proliferation was associated with an increase in DMAE concentration. A longer treatment time with trypsin was required for the groups treated with DMAE in a dose-dependent manner. In the presence of DMAE, cytosolic calcium increased in a dose-dependent manner. Apoptosis also increased in groups treated with DMAE.ConclusionDimethylaminoethanol reduced the proliferation of fibroblasts, increased cytosolic calcium, and changed the cell cycle, causing an increase in apoptosis in cultured human fibroblasts.

Liposuction Practices among Brazilian Surgeons

1 Hospital Felício Rocho, Belo Horizonte, MG, Brazil. 2 Universidade Federal de São Paulo, São Paulo, SP, Brazil. Conflicts of interest: none. Introduction: Since the 1980s, with Illouz, liposuction has gained popularity and represents one of the most commonly performed procedures in the world today. Some of the complications are serious and potentially lethal. Nevertheless, uniformity in its practice or the manner in which it is taught does not exist. Evaluating techniques employed by plastic surgeons may be the start toward standardization. Methods: A questionnaire on liposuction was given to plastic surgeons of different age groups and from regions of Brazil who were present at the 52nd Brazilian Conference for Plastic Surgery. Results: Two hundred forty-three questionnaires were filled out (n = 243). The average number of incisions was 9 (2–16). Two hundred fortyone surgeons (99%) made incisions along the anterior median/ paramedian line, and 236 (97%) made incisions on the posterior median/paramedian line. Approximately half of those surveyed utilized general anesthesia. Two hundred nine surgeons (86%) placed the patient in the prone position during the procedure. One hundred forty-six (60%) interviewees performed superficial liposuction, with 22 (9%) performing liposuction only on this adipose layer. Eighty-five (35%) participants reported controlling the apparatus’s pressure during the procedure. Conclusion: Liposuction procedures performed in Brazil have significant technical variations. This finding encourages us to reflect on the need to standardize liposuction practice and the manner in which it is taught so as to increase control over the procedure and its safety. ■ ABSTRACT