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Biomedical subjects

Marco Pignatti

Publications and source records attributed to Marco Pignatti.

8 recordsLinked to original sources
PubMed2007

The distal lateral arm flap for resurfacing of extensive defects of the digits.

The distal lateral arm flap (DLAF) was used to reconstruct six extensive defects of the digits: 2 degloving injuries of the thumb and 4 major skin losses of the fingers. Two adjacent fingers were involved in 1 patient. Flap size ranged from 3 x 7 cm to 9 x 14 cm. Four flaps were reinnervated using the posterior cutaneous nerve of the forearm. All flaps survived, though 1 showed marginal necrosis. Average follow-up was 53.4 months. Thumb opposition scored 5 according to Kapandji; finger ROM averaged 50.75%; pinch strength 72.5%. Protective sensation with touch localization was restored. Patient satisfaction for resurfaced digits averaged 8.9 on a 10-points visual analogic scale. All donor sites resulted in a painless scar with good patient satisfaction. The DLAF offers a thin, pliable skin ideal for digit reconstruction, with low rate of donor site morbidity and can be considered when toe-to-hand flap transfer is not advisable or refused by the patient.

Adult↗
PubMed2006

Calvarial bone healing under spring distension at continuous forces.

The aim of the present study was to evaluate in young animals the dynamics of calvarial bone healing when exposing a bone defect to continuous forces for up to 13 weeks. Six-week-old rabbits after a sagittal suture strip craniectomy were randomized for either of the following protocols: (1) no spring was applied (n = 7); (2) a titanium-molybdenum alloy (TMA) lower-force spring was inserted across the craniectomy gap (n = 9); (3) a stainless steel (SS) higher-force spring was applied (n = 8), or (4) sham operation (n = 8). Results showed that the surgically created calvarial bone gap was after 3 weeks kept widened both when a spring of lower force (TMA) and when a spring exerting a higher force (SS) was applied. At 6 weeks, none of the rabbits of the spring-exposed (2 and 3) groups had any bone bridging the gap, while bone bridging was visible in animals of the 2 groups (1 and 4) lacking springs. Strikingly enough, in both spring-treated groups, the surgically created defect was still after 13 weeks incompletely bridged by bone, interposed by connective tissue, most evidently in those exposed to higher forces (SS). In contrast, a normal sagittal suture enclosed by lamellar bone was seen in both the sham and the strip groups. We conclude that exposing a surgically created calvarial bone defect to continuous mechanical forces delayed the bridging of the bone defect by at least 13 weeks, even if the force exerted by either spring was very low. In any case, when a higher force (SS group) was applied, the bone reunion was efficiently prevented. No side effects were recognized.

Animals↗
PubMed2005

Long-term results of replantation of the proximal forearm following avulsion amputation.

This study reports on the long-term functional outcomes of a homogeneous series of 10 cases of successful replantation of an avulsed proximal forearm and its acceptance on the part of patients. After a minimum follow-up of 3 years (average, 4.7 years), muscular and sensory recovery was evaluated with the Medical Research Council scale, and global function according to the demerit score system of Chen (China Med 5:392-397, 1967). Subjective evaluation and patient satisfaction were investigated by means of a questionnaire. One patient was classified as grade 2, 4 patients as grade 3, and 5 patients as grade 4 according to Chen (China Med 5:392-397, 1967). However, in spite of the poor objective results, patient satisfaction was obtained in 90% of cases, and the replanted extremity was considered of help for common activities of daily living. In conclusion, replantation of an avulsed proximal forearm should be considered only in patients who are strongly motivated to maintain body integrity, and who are aware of the expected functional limitations.

Activities of Daily Living↗
PubMed2004

Effect of the two-wall-stitch mistake upon patency of rat femoral vein anastomosis: Preliminary observations.

Anastomotic patency is believed to be the most important factor in microvascular surgery. The two-wall stitch is a technical error commonly considered to cause thrombosis of the anastomosis, especially on the venous side. In order to demonstrate the real effect on vein patency of the two-wall stitch, the authors performed a standardized mistake after correct microanastomosis on the femoral vein of 15 rats, with one stitch passing through the whole thickness of the two walls of the vein. Traditional correct anastomoses on the contralateral side were used as controls. Patency was assessed at 5, 20, and 60 min and at 24 h by the milking test, and by direct section of the vessel at 24 h. The results showed no statistically significant difference between the two techniques. Histological examination confirmed the clinical judgment about the vessel's patency, and ultrastructural microscopy evidenced only mild signs of endothelial activation. In conclusion, this study indicates that the occasional two-wall stitch does not necessarily increase the risk of venous occlusion in anastomoses of the rat femoral vein.

Anastomosis, Surgical↗
PubMed2002

Keratinocytes enriched for stem cells are protected from anoikis via an integrin signaling pathway in a Bcl-2 dependent manner.

Because inhibition of integrin signaling induces apoptosis, we investigated whether keratinocytes expressing beta1 and alpha6beta4 integrins (enriched for stem cells) are protected from cell death. Keratinocytes rapidly adhering to type IV collagen expressed highest levels of beta1 and alpha6beta4 and of the anti-apoptotic stem cell marker p63. Apoptotic cells were significantly higher in slowly adhering than in rapidly adhering keratinocytes. Anti-beta1 integrin caused a significant increase in apoptotic cells, while it decreased Bcl-2 levels in stem keratinocytes. Bax and Bad proteins were higher in slowly adhering than in rapidly adhering cells. By contrast, Bcl-2, Bcl-x and Mcl-1 proteins were highest in rapidly adhering keratinocytes and nearly absent in slowly adhering cells. After addition of anti-beta1 integrin, the apoptotic rate was significantly higher in HaCaT cells not expressing Bcl-2 than in controls. These results indicate that keratinocytes enriched for stem cells are protected from apoptosis via beta1 integrin, in a Bcl-2 dependent manner.

Anoikis↗