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Biomedical subjects

A Raffi

Publications and source records attributed to A Raffi.

At least 19 recordsLinked to original sources
PubMed2006

Silicone based polyurethane materials: a promising biocompatible elastomeric formulation for cardiovascular applications.

The biocompatibility of a new material for cardiovascular applications constituted by a poly(ether)urethane (PEtU) and a silicone [polydimethylsiloxane (PDMS)] was evaluated. The achieved material shows properties similar to both polyurethanes and silicones. The material was transformed into porous membranes by a spray-deposition technique. Since any material preparation and manufacturing procedure may introduce some toxicity, in vitro cytotoxicity screening tests were carried out. Human umbilical vein endothelial cells (HUVECs) and a mouse fibroblasts cell line (L929) were cultivated with extracts obtained from materials containing 10, 40 and 100% (w/w) of PDMS. The commercially available Estane 5714-F1 and Cardiothane 51 were used as controls. Extracts were incubated up to 72 hours with HUVECs and L929 cells. The cytotoxic effect was evaluated by light microscopy, cell viability (MTT reduction and neutral red uptake) and proliferation (5-bromo-2'-deoxyuridine incorporation) tests. In vivo studies were carried out using materials containing the same PDMS percentages as for in vitro experiments. The same commercial controls were used. Results obtained with cell culture studies agreed with those obtained in the in vivo experiments and showed that the material preparation and manufacturing procedure do not introduce any toxicity in the products at each PDMS concentration investigated.

Animals↗
PubMed2002

Light microscopy evaluation of polyurethane vascular grafts porosity by Sudan Black B staining.

In small-diameter vascular grafts, the porosity of the internal surface plays an important role because it affects initial thrombus deposition and therefore the graft's patency. As well as many other studies reported in the literature we have carried out a study of the relationship between porosity and the manufacturing parameters of polyurethane (PU) grafts by standard scanning electron microscopy (SEM) analysis. However, SEM was not completely satisfactory for evaluating the 'sponge-like' uptake of water by the graft due to the unavoidable water loss and metal coating during preparation. In fact this preparation produces artefacts of the three-dimensional porous structure. To avoid this problem we investigated the possibility of observing the graft's internal surface through a stereomicroscope after it had absorbed water. We looked into a simple staining procedure which preferentially colours the PU graft fibres with respect to the void areas. After testing different kinds of stains, we eventually found that Sudan Black B, which usually stains for all kinds of lipid, turned out to be an excellent stain for the water-loaded PU grafts when diluted with ethanol. This staining procedure, coupled with a computerized image analysis system, allowed us to evaluate the degree of void and average void size of the graft internal surface and to correlate these data with graft density and manufacturing parameters.

Azo Compounds↗
PubMed1987

[11q trisomy: apropos of 2 cases].

The authors report two new cases of 11q trisomy, one due to a "classical" (11q; 22q) translocation, one due to a desequilibrated (8q; 11q) translocation (de novo). The 2 phenotypes are compared with the data of the literature on the 11q trisomy syndrome.

Chromosomes, Human, Pair 11↗
PubMed1986

[Importance of the study of allergy and determination of the HLA group in the lipoid nephrosis in children. Study of 8 cases].

Eight children with steroid-response nephrotic syndrome were investigated to study the relation-ship between steroid responsive syndrome, allergy and HLA-antigens. Six of them had clinical and/or biological allergic symptoms. The allergen was identified in four out of six cases (grass-pollen 2 cases, house dust 1 case, frullania 1 case). Six children had DR7 HLA-antigen, five had B12 antigen. Three of the four children with cortico-dependent nephrotic syndrome have associated B12-DR7 HLA antigens. Search of an allergen seems to be of interest in children with steroid-responsive nephrotic syndrome, since eviction of the allergen may be proposed as a complement to cortico-therapy.

Child↗
PubMed1985

[Congenital generalized lipodystrophy. Lipid changes. Therapeutic trials].

On the occasion of a new case of congenital generalized lipodystrophy the clinical features of this disease are reviewed. Furthermore, the frequent association of type V hypertriglyceridemia is emphasized. Various pathogenic hypotheses guide the therapeutic attempts, which are often unsuccessful.

Child↗
PubMed1984

[Truncular auriculo-ventricular block disclosing isolated corrected transposition of great vessels].

A case of atrioventricular and ventriculo-arterial discordance with L-transposition of the great arteries (corrected transposition of the great arteries), complicated by complex atrioventricular block is reported. The points of interest in this case were the association of an atrioventricular block and isolated corrected transposition, revealing the underlying malformation, and the intrahisian location of the block which seems only to have been reported on three previous occasions in this context.

Bundle of His↗
PubMed1979

[Germinoma (ectopic pinealoma) with double location : supra-sellar and the cerebellum without pineal tumour (author's transl)].

The now nine years old girl with growth retardation, started to be ill with otitis and then diabetes insipidus of central origin at 1974. A treatment with lysin-vasopressin is prescribed. The PNEG in May 1976 shows a little, pea like, suspicious, supra-sellar nodule who is not surgically explored since they was no ophtalmologic symptoms and because a normal CT scan. Corticoid and thyroid substitutive therapy is added until September 1977 when the general status becomes impaired and vomiting starts. Also because some visual loss, a new neuroradiological study is performed showing a supra-sellar tumour and a fourth ventricle mass. The CT scan asserts the double intracranial expansive process and a posterior fossa craniotomy is done with subtotal resection of a vermian tumour and Torkildsen drainage. The histology is : Immature Dysembryoma (seminoma type) or germinoma. The follow-up was good under hormonal care. X Rays Therapy over the posterior fossa, the suprasellar region, the brain and the spinal channel was instaured. Four months later, the CT scan shows normal sized ventricles and no tumour mass at all. This case gives the authors opportunity for comments and to study the concerned literature.

Brain Neoplasms↗
PubMed1975

[Primary malignant tumor of the liver in children].

Primary malignant tumours of the liver in children are rare. They occur in more than 50% of cases before the age of 2 years. The clinical signs are very often limited to a large mass in the right hypochrondrium. A search for alphafoetoprotein and arteriography are the most useful investigations for diagnosis. The pathology leads one to distinguish hepatoblastomas and hepatocarcinomas. The prognosis in these tumours remains poor for, in spite of progress in liver surgery, a cure is rarely possible. It is important for doctors to recognize the existence of this tumour pathology in order to give a chance for surgery to succeed in these young children. To illustrate this, 5 cases from Besançon are reported here.

Adolescent↗