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Biomedical subjects

M Benvenuto

Publications and source records attributed to M Benvenuto.

9 recordsLinked to original sources
PubMed1999

Successful anastomosis between tissue-engineered intestine and native small bowel.

BACKGROUND: Previous work from this laboratory has shown that isolated intestinal epithelial organoid units on porous biodegradable polymer scaffolds formed vascularized cysts lined by a neomucosa. The purpose of this study was to demonstrate anastomosis between tissue-engineered intestine and the native small bowel and to observe the effect of this anastomosis on cyst growth. METHODS: Intestinal epithelial organoid units from neonatal Lewis rats were seeded onto porous biodegradable polymer tubes made of polyglycolic acid, and they were implanted into the omentum of adult male Lewis rats. Three weeks after implantation, the unit-polymer constructs were anastomosed in a side-to-side fashion to the native jejunum in 20 rats (group 1). The other 18 rats were closed without anastomosis (group 2). All 38 tissue-engineered constructs were harvested 10 weeks after implantation. Four rats underwent upper gastrointestinal (GI) study before they were killed. RESULTS: The rats in group 1 increased their body weights equal to those in group 2, and there was no statistically significant difference between the two groups. Upper GI examinations revealed no evidence of either bowel stenosis or obstruction at the anastomotic site. Grossly, the patency of the anastomosis was 90% and the lumen of the cyst was visualized by the upper GI study. At the second operation, there was no significant difference in the size of the cysts in either group: however, at the time the rats were killed, the length of the cysts in group 1 was significantly longer than that in group 2 (P<0.05 using Mann-Whitney U test). Histological examination showed that cysts after anastomosis were lined by a neomucosa in continuity to native small bowel across the anastomotic site and also demonstrated crypt-villus structures. Morphometric study demonstrated that cysts in group 1 had significantly greater villus number, height, and surface length than did those in group 2. CONCLUSIONS: Anastomosis between tissue-engineered intestine and native small bowel resulted in no complications after the operation, kept a high patency rate, and maintained mucosal continuity between the tissue-engineered intestine and native small bowel. Furthermore, anastomosis had a positive effect on cyst size and development of the mucosa in the tissue-engineered intestine.

Anastomosis, Surgical↗
PubMed1999

End-to-end anastomosis between tissue-engineered intestine and native small bowel.

The purpose of this study was to demonstrate the feasibility of end-to-end anastomosis between tissue-engineered intestine and native small bowel and to investigate the effect of this anastomosis on their growth. Microporous biodegradable polymer tubes were created from a fiber mesh of polyglycolic acid sprayed with 5% polylactic acid. Intestinal epithelial organoid units were harvested from neonatal Lewis rats and seeded onto polymers. These constructs were implanted into the omentum of adult Lewis rats. Three weeks after the implantation, the constructs (n = 7) were anastomosed to the native jejunum in an end-to-end fashion. Ten weeks after implantation, the tissue-engineered intestine was harvested. Four of 7 rats survived for 10 weeks and the overall patency rate of the anastomosis was 78% (11 of 14 anastomosis). The maximal length of the tissue-engineered intestine at week 3 and 10 was 1.80 +/- 0.32 and 1.93 +/- 0.39 cm (mean +/- SD). Histologically, the tissue-engineered intestine was lined with a well-developed neomucosal layer that was continuous with the native intestine. We conclude that anastomosis between tissue-engineered intestine and native small bowel had a moderately high patency rate and had a positive effect on maintenance of the size of the neointestine and development of the neomucosa.

Anastomosis, Surgical↗
PubMed1999

Skeletal muscle tissue engineering using isolated myoblasts on synthetic biodegradable polymers: preliminary studies.

Skeletal muscle is responsible for the control of voluntary movement and the maintenance of structural contours of the body. Muscle loss or deficiency is encountered in various pathological states, and attempts to correct them have been employed with limited success. The aim of the present study was to tissue engineer three-dimensional vascularized skeletal muscle using isolated myoblasts attached to synthetic biodegradable polymer for tissue replacement in the enhancement of muscle regeneration. Myoblasts derived from neonatal rats (3-5-day-old), Fisher CDF-F344, were seeded onto polyglycolic acid meshes and implanted into the omentum of syngeneic adult Fisher CDF-F344 rats. Rats were sacrificed on day 30 and day 45 after the transplantation, and the cell-polymer constructs were harvested for morphological analysis. Histological analysis of the constructs were performed by hematoxylin and eosin, and immunohistochemical staining was positive for alpha sarcomeric actin and desmin skeletal muscle marker. Viable myoblasts organized between strands of degrading polymer mesh formed the new tissue, and vascularization of the entire construct was observed. Organization of neomuscle strands surrounded by vascularized tissue composed of degrading polymer and fusing myoblasts demonstrated the ability of myoblast constructs to survive, reorganize and regenerate tissue-like structures. Since myoblast transplantation to date has been limited to the cellular level of replacement, myoblast-polyglycolic acid constructs may be useful in defining the application of tissue engineering for future skeletal muscle transplantations.

Actins↗
PubMed1993

[Heart sarcoidosis. A case of mitral and ascending aorta involvement].

We describe a case of cardiac sarcoidosis manifested by arrhythmias, shock, chest pain, mitral valve prolapse and incompetence, aortic vascular involvement. Steroid therapy corrected shock and arrhythmias, but was unable to prevent the progression of the mitral valve insufficiency. Subsequently pulmonary and tricuspid valve incompetence were also observed.

Adult↗
PubMed1987

[Pulmonary and systemic embolism in a case of biatrial thrombosis. Role of two-dimensional echocardiography].

The authors describe the case of a 61-year-old woman affected with pulmonary embolism, in whom the presence of masses in both atria has been detected by two-dimensional echocardiography. The event of a systemic embolism and the dissolution of both masses after an anticoagulant therapy, has induced the authors to diagnose a biatrial thromboembolism propagating from the venous system and passage of thromboembolic material through a patent foramen ovale. These findings are, therefore, in differential diagnosis compared with other biatrial intracavitary masses.

Diagnosis, Differential↗
PubMedDate not supplied

[Tibial valgization osteotomy in gonarthrosis with or without chondrocalcinosis. Results after 5 years].

The authors compare the results of valgisation tibial osteotomies in osteoarthrosis of the knee (146 cases) and osteoarthrosis of the knee with chondrocalcinosis (94 cases). The two groups were identical in terms of age, but differed by sex ratio (female predominance in CCA) and the initial radiological stage (more advanced forms in the CCA group). Results differed after the second year and reached significantly different values at 5 years (73% in knee osteoarthrosis as against 34% good clinical results in chondrocalcinosis). Study of two groups of patients paired for age, sex, weight and radiological stage showed that results at 5 years were significantly less good in the CCA group. These results are discussed and compared with those in the 1990 literature.

Adult↗