Nicolae Ghetu

Training of microsurgical skills on nonliving models.

Although direct exposure to procedures in the operating theater environment, together with practice on laboratory animals, is still seen as the gold standard of teaching in microsurgery, practice on nonliving simulators is currently being validated as an important educational tool. We reviewed the widely used nonliving training models, together with currently accepted innovations, which are parts of curricula of training courses in microsurgery. Using the experience accumulated in training programs at the Centre for Simulation and Training in Surgery, we identified which particular skills can be reliably targeted by each nonliving tissue exercise. We were able to find five groups of nonliving training models: basic manipulation, knot‐tying principles, completing the anastomosis, the real tissue experience, and training in virtual reality. The more abstract models might seem quite far from the real life experience, but they each closely address specific skills. It thus becomes convenient for the instructor to train these skills separately. This generates series of consistently favorable results once the skills are integrated into a more complex procedure. Focused exercises, once assembled in continuity, reconstruct the real life scenario. The training program can comprise a series of increasingly difficult exercises, which mirror the real life situations. Performance on nonliving models in each progressively more challenging exercise can be assessed via direct observation, assisted by clear and objective criteria. Finally, focused training will help both the transition to human surgery and replication of the favorable results to large series of subjects.

New antimicrobial chitosan derivatives for wound dressing applications.

Chitosan is a non-toxic, biocompatible, biodegradable natural cationic polymer known for its low imunogenicity, antimicrobial, antioxidant effects and wound-healing activity. To improve its therapeutic potential, new chitosan-sulfonamide derivatives have been designed to develop new wound dressing biomaterials. The structural, morphological and physico-chemical properties of synthesized chitosan derivatives were analyzed by FT-IR, (1)H NMR spectroscopy, scanning electron microscopy, swelling ability and porosity. Antimicrobial, in vivo testing and biodegradation behavior have been also performed. The chitosan derivative membranes showed improved swelling and biodegradation rate, which are important characteristics required for the wound healing process. The antimicrobial assay evidenced that chitosan-based sulfadiazine, sulfadimethoxine and sulfamethoxazole derivatives were the most active. The MTT assay showed that some of chitosan derivatives are nontoxic. Furthermore, the in vivo study on burn wound model induced in Wistar rats demonstrated an improved healing effect and enhanced epithelialization of chitosan-sulfonamide derivatives compared to neat chitosan. The obtained results strongly recommend the use of some of the newly developed chitosan derivatives as antimicrobial wound dressing biomaterials.

The Effects of Adipose-Derived Stem Cell-Differentiated Adipocytes on Skin Burn Wound Healing in Rats.

Both adipose-derived stem cells (ADSCs) and fat grafting promote burn wound healing, but whether adipogen-derived cells using various inducers such as 3-isobutyl-1-methylxanthine (IBMX) and insulin affect wound healing is unknown. Herein, ADSC-differentiated adipogenic lineages were used in rat burn wounds to evaluate wound healing potential. ADSCs were cultivated using six different adipogenic differentiation conditions (IBMX ± insulin, IBMX for 5 days, high and low Dulbecco’s modified Eagle’s medium) and in vitro morphological changes and cell proliferations during adipogenic differentiation were recorded. Intermediate burn wounds were inflicted in 15 Wistar male rats. Afterwards, the rats were divided into five groups for subcutaneous injections under the wounds: control; ADSCs; differentiated adipocytes (−IBMX+INSULIN and +IBMX[D1–5]+INSULIN) and fat prepared by Coleman technique. Macroscopic changes and histology were documented for 3 weeks. Repeated measures analysis of variance was performed to analyze cell growth and wound healing with a statistical level set of P < .05. Induction cocktails significantly reduced proliferation and induced lipid droplet accumulation. Conditioning without insulin induced the least lipid accumulation, while discontinuing IBMX generated larger adipocytes (P < .001). Adipogenic differentiated ADSCs had similar wound healing abilities with ADSC and fat injections, but differentiated adipocytes (+IBMX[D1–5]+INSULIN) and fat grafting accelerated the early healing process relative to ADSC (P < .001). Reduced fibrosis and mild inflammatory infiltration limited to superficial dermis were observed in +IBMX(D1–5)+INSULIN and fat injection groups, while those reactions were mild to moderate in ADSC group. Differentiated adipocytes achieve similar wound healing results compared with ADSC and fat injections, but differentiated adipocytes (+IBMX[D1–5]+INSULIN) and fat grafting accelerate early healing relative to ADSC.

Sulfadiazine—Chitosan Conjugates and Their Polyelectrolyte Complexes with Hyaluronate Destined to the Management of Burn Wounds

In the present study polyelectrolyte complexes (PECs) based on new sulfadiazine-chitosan conjugates with sodium hyaluronate have been developed with potential use in treatment of burn wounds. The PECs were chemically characterized using Fourier Transform—Infrared Spectroscopy, Scanning Electon Microscopy and Near Infrared Chemical Imaging Technique. The swelling behavior and in vitro sulfadiazine release were also investigated. The antimicrobial activity was evaluated towards three bacterial strains: Escherichia coli, Listeria monocytogenes and Salmonella thyphymurium. The developed PECs demonstrated their antimicrobial efficiency against tested bacterial strains, the PECs containing sulfadiazine-modified chitosan being more active than PECs containing unmodified chitosan.

Role of mucosal high-risk human papillomavirus types in head and neck cancers in Romania

Background Limited information is available about the involvement of human papillomavirus (HPV) in head and neck squamous cell carcinomas (HNSCCs) in Romanian patients. Objective To evaluate the HPV-attributable fraction in HNSCCs collected in Northeastern Romania. Materials and methods In total, 189 formalin-fixed paraffin-embedded tissue samples (99 oral cavity tumors, 28 oropharynx, 48 pharynx, and 14 larynx/hypopharynx) were analyzed for HPV DNA and RNA using Luminex-based assays, and for overexpression of p16INK4a (p16) by immunohistochemistry. Results Of the 189 cases, 23 (12.2%) were HPV DNA-positive, comprising half of the oropharyngeal cases (14/28, 50.0%) and 9/161 (5.6%) of the non-oropharyngeal cases. HPV16 was the most prevalent HPV type (20/23, 86.9%), followed by HPV18 (5/23, 21.7%) and HPV39 (1/23, 4.3%). Only two (2/189, 1.1%) HNSCC cases were HPV-driven, i.e. positive for both HPV DNA and RNA. Conclusion A very small subset of HNSCC cases within this cohort from Northeastern Romania appeared to be HPV-driven.

Bilateral V-Y advancement gluteal fold flaps following vulvo-vaginal melanoma resection

The soft tissue defects of the anterior perineum can be caused by tumour excision, trauma, burns, Fournier’s gangrene and genital mutilation. Various reconstruction methods were described: vacuum-assisted closure, skin grafts and skin substitutes, pedicled or free flaps. In the case of defects following oncologic surgery, flaps are the reconstructive method of choice. We present the case of a 65 year-old woman diagnosed with stage III A vulvo-vaginal melanoma affecting also the distal urethra. Radical vulvectomy and en-bloc excision of the anterior third of the vagina and distal urethra, along with bilateral inguinal lymphadenectomy was performed. The resulting defect was covered with bilateral V-Y advancement gluteal fold flaps. A local vaginal recurrence appeared 18 months after surgery and was safely removed. The patient followed chemotherapy with Dacarbazine. The gluteal fold flap offered good defect coverage and survived completely. Follow-up period was two years without distant metastases. Functional result was excellent, urinary function being normal and patient satisfaction high. Due to the gluteal flap’s advantages (appropriate thickness, good vascularity, minimal donor site morbidity, and same operative field allowing for shorter operating time), reconstruction of the anterior perineum after oncological resection with bilateral V-Y advancement gluteal flaps is a viable solution.

Integra for penile coverage after traumatic degloving – case report

Penile soft tissue defects can be caused by tumor excision, trauma, burns, Fournier’s gangrene and self-mutilation. Reconstruction of such defects has been achieved through various methods (local or regional flaps, full-thickness or split-thickness skin grafts, skin substitutes). Although no consensus has been reached, it seems that split thickness skin grafts are the method of choice. Penis resurfacing is a delicate procedure, especially in potent men, as it aims normal coverage, sensibility, aesthetic aspect and restoring erectile function with sexual satisfaction. We present a case of traumatic avulsion of the anterior perineum successfully treated using split thickness skin grafts for the testicles and Integra for the penis. The follow-up period was 5 years. Functional result was excellent, the penile skin regaining its elasticity, flexibility and pliability. No urinary problems or erectile dysfunctions were noted. Due to its advantages (skin elasticity, limited hypertrophic scar formation and inhibited myofibroblasts contraction) Integra might be the optimal penile coverage solution.