Biomedical subjects

F Lefebvre

Publications and source records attributed to F Lefebvre.

At least 55 records · Page 3Linked to original sources

PubMed1991

In vitro studies of elastin-fibrin biomaterial degradation: preservative effects of protease inhibitors and antibiotics.

The degradability of a new elastin-fibrin material was tested in vitro versus human pancreatic elastase (HPE) and plasmin (PL) activities. It is shown that aprotinine Iniprol, a well-known protease inhibitor and Eglin C, a new potent inhibitor of HPE, especially when used in synergy, efficiently protected the material. A small amount of specific antibiotics was incorporated into the material. The two products will allow the material to be used in digestive surgery with improved safety.

Adsorption↗

PubMed1991

In vitro association of type III collagen with elastin and with its solubilized peptides.

Elastin fibres or elastin solubilized peptides associated with type III collagen, under physiological conditions, to form a gel-like substance. The gel cohesion could be markedly improved either by desiccation process (gently air-dried rather than lyophilized) or by addition of adhesive connective proteins such as fibronectin, laminin and type IV collagen. They conferred to the material the composition and the structural appearance of typical basement membrane-like structure. Their properties enable us to investigate the biomaterial in several domains.

Adhesiveness↗

PubMed1991

[Breast feeding of low birth weight newborn infants].

Incidence and duration of lactation among mothers of preterm or low birth-weight infants is quite good compared to that of mothers of term infants. However numerous problems are encountered by their infants when breast feeding including poor suction and need for daily supplemental bottle feeding.

Breast Feeding↗

PubMed1991

[Femoro-patellar instability in children and adolescents].

93 knees in 74 patients between 9 and 20 years of age were operated because of patello-femoral instability. In 76 cases, it was due to an intractable patello-femoral syndrome and in 17 cases one or several episodes of patellar dislocation had occurred. Treatment consisted, after failure of physical therapy, 14 times in a leavering of vastus medialis with a lateral capsular release and medial capsularrophy. In 71 cases it was associated to a medial transfer of the patellar ligament. Results were studied in 85 knees after an average follow-up of 6 years. 45 knees were completely symptomless, an excellent result. 34 knees remained with some kind of pain and 6 patellae redislocated. It is concluded that the transfer of the patellar ligament should be associated to the dynamic realignment achieved by the vastus medialis transfer for better results.

Adolescent↗

PubMed1990

Biocompatibility of elastin-fibrin material in the rat.

Biocompatibility and biodegradability of a new elastin-fibrin material were investigated in several organs and tissues of the rat. It has been demonstrated that the material was quite well tolerated in all cases, except in bone marrow. Its use is considered in several aspects of reparative or constructive surgery.

Animals↗

PubMed1990

[Open reduction by the Dunn technique in upper femoral epiphysiolysis. Report of 14 cases].

Fourteen of Dunn's operations for slipped upper femoral epiphysis were analysed in their indications and their results in comparison with others series. The open operation of the femoral head is a good method for the chronic highest displacements. The notion of an acute displacement leads us to ask for a previous bone scintigraphy in order to make sure of the integrity of the vascularisation. Thus, there was no complication of necrosis in this surgery, but unfortunately, there were two chondrolysis and one mechanical accident.

Adolescent↗

PubMed1990

[Congenital vesicovaginal fistula. Commentary and review of the literature apropos of a case].

A case of urinary incontinence through vesico vaginal fistula is related in a five year old girl. Its congenital origin is probable. The right ureteral orifice joins up with the fistula, in full duct. The corresponding kidney is hypotrophic and subjected to the vesico renal flow of the third degree. The incontinence disappears immediately. The literary studies have been analysed. Few are really vesico vaginal fistulas and few have a congenital origin.

Child, Preschool↗

PubMed1989

Incidence and duration of lactation and lactational performance among mothers of low-birth-weight and term infants.

The lactation experience of 55 mothers of 62 infants of low birth weight (2500 g or less) was prospectively compared with that of 55 mothers of 55 control infants (38 weeks' gestation or more, birth weight more than 2500 g) born at the same institution. The incidence rates of lactation at delivery were 73% for the control group and 58% for the low-birth-weight group; 11% of the infants of low birth weight fed breast milk were never put to the breast. The mean age at first suckling was 277.3 hours in the low-birth-weight group, compared with 3.3 hours in the control group (p less than 0.0005). At first suckling 81% of the low-birth-weight infants and 25% of the control infants sucked poorly or refused the breast (p less than 0.001). At discharge 65% of the breast-milk-fed control infants were exclusively breast-fed, compared with 3% of the low-birth-weight infants fed breast milk (p less than 0.001). The incidence rates of lactation over time were similar in the control and low-birth-weight groups (51% v. 44% at 1 month, 29% v. 13% at 3 months, 13% v. 4% at 6 months and 4% v. 2% at 12 months). The mean duration of lactation was 3.2 months for the control group and 2.5 months for the low-birth-weight group. In the long term 37% of the low-birth-weight infants fed breast milk failed to breast-feed, compared with 2% of the control infants, and only 31% were exclusively breast-fed, compared with 85% of the control infants (p less than 0.001). However, the degree of satisfaction with the lactation experience was similar in the two groups. We conclude that mothers of low-birth-weight infants have good potential for lactation.

Breast Feeding↗

PubMed1989

Repair of experimental arteriotomy in rabbit aorta using a new resorbable elastin-fibrin biomaterial.

A new artificial connective matrix which results from two reactions of fibrinogen and fibronectin on elastin was used to obturate a slit made in the abdominal aorta of rabbit. The so-called Elastin-Fibrin biomaterial behaved as a scaffold through which all the different structures were restored to their former condition. At 3 months, the material had disappeared and no thrombus, no inflammation or reject had been detected.

Animals↗

PubMed1989

Some factors affecting properties of elastin-fibrin biomaterial.

The elasticity, mechanical strength and permeability of a new biomaterial made of elastin and fibrin were investigated. It was shown that gamma-irradiation to sterilize the product, and sulphur derivatives (Merceptyl, thiourea, cystein) working as reticulating agents modified these properties. Depending on whether or not the biomaterial needs to be stiff, strong or elastic both physical processes could intervene separately or together. The good permeability of this material allows it to be used in several surgical fields as a true artificial connective matrix.

Biocompatible Materials↗

PubMed1989

[Adjusted cupula in the treatment of massive osteonecrosis of the upper part of the femur in adolescent children].

Six important necrosis of the apophysis of the femur were treated by arthroplasty with adjusted cup. This operation always made these hips painless, 5 times, the mobility was greatly improved. This a normal social life was quickly recovered. However, the distant future remains uncertain. With the exception of one immediate failure, one hip had to be reoperated, 8 years after the total arthroplasty.

Activities of Daily Living↗

PubMed1989

[Liposarcoma in children. Apropos of 3 cases and a review of the literature].

Liposarcoma is an uncommon tumour in childhood. Three cases are reported. Two patients remain alive and well without local recurrence or metastasis following the initial treatment, however one patient died as a result of direct tumour extension despite chemotherapy. A review of the literature revealed the following features: the extremity are the most common location, the predominance of myxoid histology and its best prognosis. The treatment is the complete surgical excision, the efficiency of radiotherapy or chemotherapy has not been formally proved.

Buttocks↗

PubMed1989

[Surgical treatment of gastroesophageal reflux in the child using Dor's anterior partial fundoplication procedure. Report of 37 cases].

A retrospective study of 37 children with gastroesophageal reflux, treated by Dor's anterior partial fundoplication procedure, objects a good clinical result in a rate of 95%. The late radiologic examinations confirm a good result in 84%, without gastroesophageal reflux or fundoplication alteration, with a mean follow-up of 6 years. The late efficiency of the partial fundoplication is assured by a safe fixation of the abdominal oesophagus and the partial fundoplication to the diaphragnatic crus.

Child↗

PubMed1988

Biochemical study of adduct synthesis between fibrin monomers and elastin.

Monomers of fibrin generated by thrombin from fibrinogen reacted with elastin to give a new addition product or adduct. Adduct formation resulted from a covalent bond between fibrin monomers and elastin. The kinetic studies of this reaction confirmed that the adduct was formed before fibrin precipitated to produce the clot. The reaction depended on elastin, fibrinogen and thrombin concentrations. When thrombin-induced and reptilase-induced fibrin were compared, it became obvious that fibrin monomers did intervene more commonly as Des AA-fibrin than as Des AA.BB-fibrin. The adduct synthesis was completely inhibited by 150 microM of the peptide Gly-Pro-Arg-Pro which was previously known to stabilize the fibrin monomers and consequently to inhibit the polymerization completely. It is shown that FXIII could intervene directly in the reaction where homological quality of elastin (human versus bovine) and purity of thrombin were other important factors.

Animals↗

PubMed1988

Outcome at school age of children with birthweights of 1000 grams or less.

A follow-up study was done of extremely low-birthweight infants (less than or equal to 1000g) born between 1976 and 1979, a period when aggressive intervention was not routine practice. The survival rate was 19 per cent. 44 of the 46 survivors were followed to a mean age of 6 1/2 years. By five years of age 23 of the 44 children had been admitted to hospital, mainly for surgery and respiratory problems. Eight of 31 five-year-old children were growth-retarded and five of 26 were microcephalic. Among 44 children, ophthalmological problems were found in nine cases and neurosensory impairments (cerebral palsy, deafness) in seven. 12 children were mentally handicapped or had impaired intelligence (IQ or DQ less than 85). Over-all, 14 of the 44 children had impairments, severe in four cases and moderate in 10. Mean verbal IQ was significantly lower than mean performance IQ. Among 37 children in school or in remedial programs, nine required special education and another 12 in regular classes either failed or had very poor results, or needed extra professional help. Only 16 of the children had no significant problems in school. These findings indicate that extremely low birthweight (less than or equal to 1000g) represents a major risk to life, health (hospital admissions), long-term growth, neurosensory integrity, cognitive development and learning potential.

Child↗

PubMed1988

[Disseminated osseous lymphangiomatosis. Apropos of 6 case reports].

Following six cases of disseminated bone lymphangiomatosis, the problem of potential haemorrhagic complications in the patients evolution has been focused. Consumption coagulopathy associated there, must be taken into account in view of therapeutic choices and vital prognosis evaluation.

Adolescent↗

PubMed1987

A new reconstituted connective tissue matrix: preparation, biochemical, structural and mechanical studies.

A fibrinogen derivative generated by thrombin was reacted with elastin to yield a new addition product or adduct between the two proteins. Addition of fibronectin, and then of collagen, did not interfere with the basic elastin-fibrinogen reaction and conferred the qualities of an artificial connective tissue to the product. Biochemical, structural and biomechanical aspects of the new matrix were studied. Aprotinin, heparin, thiomersal, and thiourea did not inhibit the main reaction; indeed, some of these ingredients improved the matrix cohesion. Scanning electron microscopy showed the genesis of a true network whose meshes were more reticulated by the addition of thiourea. Biomechanical studies, i.e., strength and elasticity showed the thiourea matrix to be the strongest. These intrinsic properties suggest the product could have biological and clinical applications.

Biocompatible Materials↗

PubMed1987

Adduct formation between soluble fibrin monomers and elastin.

Monomers of fibrin generated from fibrinogen by thrombin reacted with elastin to give a new addition product or adduct. The adduct formation results from a covalent bond between both proteins, formation of which is dependent on elastin, fibrinogen and Ca2+ concentrations; but, Factor XIIIa did not intervene. Addition of fibronectin, together with fibrinogen, as cold insoluble proteins from human plasma, and of soluble collagen from rat tail tendon did not inhibit the first reaction. This enabled us to elaborate a new artificial connective matrix.

Animals↗