Biomedical subjects

F Boissier

Publications and source records attributed to F Boissier.

9 recordsLinked to original sources

PubMed2003

[Quality of life after corneal transplantation: a retrospective study].

PURPOSE: To assess how clinical and social characteristics influence health-related quality of life among patients who have undergone corneal transplantation. METHODS: Sixty-eight patients followed up for at least 1 year after corneal transplantation participated in this study. Data were collected on social status, systemic co-morbidities, ocular history, best corrected visual acuity, and a detailed ocular examination. Questionnaires that allowed calculation of VF14 and the SF36 scores were filled out for each participant interview. The associations between questionnaire outcomes and social status, ophthalmic status, and general health were evaluated using one-way analysis of variance and multiple stepwise linear regression. RESULTS: The mean best-corrected visual acuity (BCVA) was significantly better in the operated eye for keratoconus and dystrophies than for bullous keratopathy. There is a strong relationship between BCVA in the operated eye and the VF14 score (beta=8.45, p=0.005) and also between BCVA of the contralateral eye and the VF14 score (beta=19.91, p<0.0001). Correlations between VF14 and SF36 were all positive (range r=0.29-0.49, p<0.01). CONCLUSION: This retrospective analysis provided strong evidence for the validity and reliability of the VF14 as an instrument for testing visual disabilities or satisfaction in patients who had corneal transplantation. Astigmatism or anisometropia did not affect VF14 and SF36 scores. The most important factors associated with the VF14 score and SF36 measures were the visual acuity of the operated eye as well as the contralateral one, including their physical function, vitality, and the patient's perception of mental and general health.

Corneal Transplantation↗

PubMed2003

[Calcium and electropermeabilized cells].

Trains of short and intense electric pulses may induce a reversible local permeabilization on the membrane of the treated cells. Hydrophilic species can then almost freely cross the envelope and either enter or escape from the cytoplasm. The purpose of the present study was to investigate the possibility of introducing well defined amounts of Ca2+ ions within the cell. Chinese hamster ovary cells were used as a model system. When the pulsing buffer contained high levels of free Ca2+, the survival of cells was strongly affected. A 1 mM level was well tolerated. When cells were pulsed under moderated field conditions, it was observed that Ca2+ entered cells very rapidly (second time range). But the basic cytoplasmic level was set back spontaneously within a few minutes. The perspectives of this electrical injection are discussed for basic cell biology and high-throughput biotechnology.

Animals↗

PubMed1999

[French Directory of Eye Banks. Report on activities during 1993-1997].

PURPOSE: To describe the activity of the eye banks participating in the French Eye Bank Directory over the period 1993-1997. METHODS: Since 1993, the eye banks have answered annually a questionnaire concerning technical aspects (procurement procedures, microbiological testing, tissue evaluation and preservation procedures) and activity (number of corneas processed, preserved and issued). Data from these banks were collected and presented in the Directory each year. RESULTS: In 1997, a total of 2,432 eyes were processed. Most of the eye banks (84%) used organ culture as the storage method. Thirty percent of the processed corneas were not used for transplantation. The main reasons for discarding corneas were inadequate endothelium before preservation (15.5%) and positive serology (27%), contamination during preservation (4.6-7.2%), and inadequate endothelium after preservation. CONCLUSION: Quality assurance, microbiological safety and tractability requirements are currently an integral part of the cornea transplantation circuit in France. Publication of eye bank activity has enabled and evaluation of the different procedures.

Cornea↗

PubMed1997

[Cup dissociation after reduction of a dislocated hip hemiarthroplasty].

PURPOSE OF THE STUDY: Close reduction of a bipolar hemiarthroplasty dislocation may induce dissociation between the cup and the prosthetic ball head. This rare complication leads to reoperation. CASE REPORT: Two women 84 and 85 years' old suffering from femoral head fracture were treated by bipolar hemiarthroplasty through a postero-lateral approach. After the first post-operative month, a posterior dislocation has occurred. Close reduction, without anesthesia dislocated the intraprosthetic joint. DISCUSSION: Dislocation rate is lower for bipolar hemiarthroplasty than for total hip arthroplasty. Reason for these two dislocation was supposed to be a "bottle-opener" effect's by locking the cup on to the posterior acetabular rim. Limb traction is responsible for intra-prosthetic iatrogenic dislocation. CONCLUSION: Anesthesia should be considered as necessary for prosthesis bipolar hemiarthroplasties dislocation treatment. The authors have moved to a different implant and modified their surgical approach (antero lateral). These modifications were introduced in order to reduce the rate of hip dislocation and above all the event of intraprosthetic dislocation when close reduction was necessary.

Aged↗

PubMed1991

Sertoli cell-specific expression of the human transferrin gene. Comparison with the liver-specific expression.

We present a comparative study of the cis- and trans-acting elements governing the expression of the human transferrin (Tf) gene in two tissues, liver and testis, where Tf is expressed at various levels. We have previously identified the elements of the promoter, negative, and enhancer regions involved in the liver-specific expression of the gene. By transfection experiments of primary cultured rat Sertoli cells compared with hepatoma cells, DNase I footprinting, and gel retardation studies, we have analyzed 3.6 kilobase pairs of the Tf regulatory region. The far upstream enhancer functional in Hep3B cells is inactive in Sertoli cells; in the two cell types, different nuclear factors appear to bind to a DNA domain crucial for enhancer activity. Similar negative- and positive-acting elements are present in the distal promoter in both tissues. However different combinations of proximal promoter elements control tissue-specific expression. Liver-specific transcription is governed by the interaction of the Tf-LF1 protein and a C/EBP-related factor with the -125 to -45 region. In Sertoli cells, a -34 to -18 TATA box-binding factor is sufficient to initiate basal-level transcription. Efficient expression is achieved by the association of two factors binding either to the (-82, -1) or to the (-153, -52) region. The addition of a third adjacent element decreases the promoter activity, suggesting that the balance of three factors binding to the proximal sites regulates testis-specific expression.

Animals↗

PubMed1991

The enhancer of the human transferrin gene is organized in two structural and functional domains.

We previously identified a 300-base pair long enhancer, located 3.6 kilobases upstream of the cap site of the human transferrin gene. A 5' deletion up to position 86 of the enhancer resulted in complete loss of the enhancer activity. Here we show by competition footprint analysis, gel retardation assays, and transient expression studies in hepatoma and HeLa cells that the enhancer is composed of two distinct structural and functional domains, A (nucleotides 1-86) and B (nucleotides 87-291). Each domain is a proto-enhancer of a different type. Domain A is a proto-enhancer that, when multimerized, is able by itself to stimulate transcription from the heterologous SV40 promoter, both in Hep3B and HeLa cells. It contains the octanucleotide TGTTTGCT sequence and is the binding site of two liver-specific nuclear factors and of a different HeLa nuclear factor. Domain B contains four binding sites interacting with several liver nuclear proteins. In order to bind, any of these proteins requires the presence of all the others. This domain is able to block the activity of a downstream negative element, but it has no enhancer activity by itself. In the presence of the transferrin promoter, full enhancer activity requires the association of the two domains A and B.

Base Sequence↗

PubMed1990

The binding site for the liver-specific transcription factor Tf-LF1 and the TATA box of the human transferrin gene promoter are the only elements necessary to direct liver-specific transcription in vitro.

We have studied the liver-specific transcriptional activity of the human transferrin gene promoter. Results of competition experiments, site-directed mutagenesis, and 5' deletion analysis have demonstrated that a TATA box and a binding site for the liver-specific protein Tf-LF1 are the only elements needed to direct hepatic-specific transcription in vitro. Thus, Tf-LF1 behaves as other previously described proteins, HNF-1, DBP and LF-A1, in that it is sufficient to confer liver-specific transcriptional activity to a promoter in vitro. This results contrast with observations made in transient expression experiments, in which Tf-LF1 binding alone cannot direct hepatic-specific expression, and the binding of at least one more protein, similar to C/EBP, is needed. Thus, as described for other hepatic genes, the number of elements necessary to confer tissue specificity is different in vivo and in vitro.

Base Sequence↗

PubMed1989

Cell type-specific expression of the human transferrin gene. Role of promoter, negative, and enhancer elements.

Transferrin (Tf), the iron transport protein of vertebrate serum, is mainly synthesized in the liver. cis-Acting DNA elements required for liver-specific expression of the human Tf gene were identified by transient and stable expression assays in human hepatoma (HepG2 and Hep3B) and epithelial carcinoma (HeLa) cell lines. Deletion analysis of the 5' DNA sequences of the gene have defined four functionally different regions: (a) A cell type-specific promoter located between positions -125 and -45 which interacts with two nuclear factors and is sufficient for liver-specific expression. (b) A distal promoter region from -620 to -125 base pairs containing positive and negative cis-acting elements which regulate the promoter activity. (c) A negative-acting region between -1.0 and -0.6 kilobase pairs which down-regulates transcription from the Tf promoter. (d) An enhancer located between -4.0 and -3.3 kilobase pairs which is more active in hepatoma than in HeLa cells. Thus, Tf gene expression is modulated by a combination of multiple positive and negative cis-acting elements. The expression results are discussed with respect to our previous description of the trans-acting factors interacting with the proximal and distal promoter regions.

Base Sequence↗

PubMed1988

Interactions of DNA-binding proteins with the 5' region of the human transferrin gene.

We have established by transient expression experiments that the 620 base pairs upstream of the cap site of the human transferrin gene contain the information necessary for efficient expression of the gene in hepatoma cells HepG2 or Hep3B but not in HeLa cells. DNase I footprint analysis reveals that at least five distinct factors present in human or rat liver nuclear extracts interact with different sites of this region. One of these factors, binding to nucleotides -193 to -162, is closely related to or identical with the eukaryotic factor CCAAT-binding transcription factor/nuclear factor I; another one, binding to nucleotides -103 to -83 seems to be related to the CCAAT-binding protein. The binding sites of two other factors, not recognized by HeLa nuclear proteins, each contain an identical 10-nucleotide-long sequence (5' TCTTTGACCT 3') in reverse orientation, separated by 400 base pairs. Results of gel retardation assays, cross-competition experiments, and heat inactivation strongly suggest that the proteins binding to these sites are different. One of these sequences and the binding site of the CCAAT-binding protein related factor are located in the region between nucleotides -119 and -45. We have shown by transient expression experiments with 3' deleted vectors that this region is functionally essential for human transferrin gene expression.

Base Sequence↗