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Biomedical subjects

D Casanova

Publications and source records attributed to D Casanova.

At least 37 records · Page 2Linked to original sources

[Management of cleft lip and palate by the Doctor Magalon's team in Marseille].

The goal of the treatment of patients with cleft lip and/or cleft palate was: obtain a normal appearance, a normal speech and a normal growth without severe pertubations of the quality of life. Millard technique was used to repair the cleft lip in neonatal period. Between 6 and 18 months, the palate cleft was closed by wardill-kilner technique. A gingivoperiostoplasty with osseous graft was performed between 8 and 12 years. The orthodontic treatment began at 7 years. Pharyngoplasty was necessary in several cases. Sequellae and rhinoplasty was performed at the end of the growth. The authors explained their choices.

Child↗

[Longitudinal melanic nail bands (melanonychia): report of 22 cases].

INTRODUCTION: Longitudinal melanonychia is a diagnostic and treatment problem for the surgeon. Fear of melanoma most frequently leads to total excision of nail bed, matrix and plate. METHOD: Twenty two patients, aged from 7 to 77, were operated on from 89 to 98 in our department, using different techniques (total matrix biopsy, total excision of melanonichia with direct suture, Schernberg flap). RESULTS: Thumb and index are predominant locations (11 out of 16). No malignant lesions were found histologically. Aesthetic sequellae were frequent and directly linked to the width and location of the melanonychia. Limited matrix biopsy produce the best aesthetic result. DISCUSSION: Malignant lesions are rare and our series is short. Therefore an additional multicentric study is required. Our choice is to make a limited matrix biopsy in the first place with a minimal aesthetic prejudice. Histology determines the treatment choice: excision or follow up.

Adolescent↗

[15 years experience with microvascular free tissue transfert for repair of head and neck cancer defects].

We present the modalities and results obtained with free flap reconstruction of head and neck cancers defects. This retrospective review of 165 free transfers performed between 1984 and 1999 included 89 radial forearm flaps (54%), 38 latissimus dorsi flaps (23%), 28 osteomyocutaneous flaps (17%), 6 omentum flaps (4%), 2 jejunum flaps, and 2 cutaneous scapular flaps. Indications were orobuccopharynx (34%), hypopharynx (24%), mandible (17%), craniofacial (15%) and skin (10%) defects. Flap failure rate was 9%. Reconstruction of a radiated site was a statistically significant indicator of flap failure. Four types of free flaps were preferred for reconstruction of head and neck cancer defects. The radial forearm flap was used as a lap flap for the orobuccopharynx, the tubuled radial forearm flap for reconstruction of the digestive tract after total pharyngolaryngectomy, the osteomyocutaneous free fibular flap for pelvimandibulectomy, especially for the anterior arch, the latissimus dorsi flap to fill craniofacial defects, and the free omentum flap for craniofacial complications after radiotherapy.

Adenocarcinoma↗

MUSEAP, a novel reporter gene for the study of long-term gene expression in immunocompetent mice.

The improvement of gene therapy vectors would benefit from the availability of a reporter gene that can be used for long-term studies in immunocompetent laboratory animals. We describe the construction and characterization of a novel reporter gene, murine secreted embryonic alkaline phosphatase (MUSEAP). We demonstrate by gene transfer in skeletal muscle of immunocompetent mice that MUSEAP is efficiently secreted and detected in the bloodstream and that injection of an increasing dose of DNA leads to a dose-dependent increase of plasma MUSEAP activity. We also show that the expression of MUSEAP under the control of a constitutive promoter is stable for 1 year and that the activity of MUSEAP in the bloodstream reflects the changes in the transcription rate of its gene. These properties make MUSEAP the only reporter gene that can be used for somatic gene transfer into immunocompetent mice in order to study the impact of gene transfer vectors of metabolic, developmental or environmental factors on long-term gene expression.

Alkaline Phosphatase↗

Tissue expansion of the lower limb: complications in a cohort of 103 cases.

Over 10 years we performed 103 skin-expansion procedures and placed 207 prostheses on lower limbs, using the same surgical protocol. In 83 cases (80.6%) the expansion was achieved without complications. We recorded 20 complications in all (19.4%). Major complications included sepsis, damage due to undermining, exposure of the prosthesis and necrosis of the flap in 16 cases (15.5%), resulting in complete failure of the method in five cases (4.9%). In all, nine patients had septic complications (8.7% of the patients and 45% of the complications), five had exposure of the prosthesis and two had skin necrosis after expansion. Infection and skin necrosis, which are the main causes of failure of this method, can be prevented by a strict surgical protocolcovering all stages of the procedure. Atraumatic undermining, remote and external valves, suction drains in the cavities, advancement flaps and plaster casts after surgery can help to prevent skin necrosis. A separate and remote approach for each prosthesis can prevent infection of all the prostheses and complete failure of the expansion procedure.

Adolescent↗

Emergency treatment of accidental infusion leakage in the newborn: report of 14 cases.

Infusion leakage in the paediatric population of the intensive-care unit is known to cause skin necrosis and significant scarring around tendons, nerves and joints, extending the length of hospital stay. We report a series of 14 newborn children affected by accidental infusion leakage, and their early treatment with Gault's procedure: saline flush-out and liposuction. The results were good: there was no skin impairment in 11 cases and three cases of skin necrosis healed spontaneously. Early treatment of toxic infusion leakage in neonates is recommended to avoid skin necrosis at the site of extravasation. The two procedures proposed by Gault are simple and effective in such cases. They should be employed as early as possible in order to dilute and remove the toxin from the subcutaneous tissue.

Cardiotonic Agents↗

Aplasia cutis congenita. Report on 5 family cases involving the scalp.

Aplasia cutis congenita (ACC) is a rare malformation involving the scalp and sometimes the underlying tissues. It may occur as an isolated defect or be combined with congenital malformations and there is often a family background. The mortality rate is high, with infectious and vascular complications. We report our experience based on the treatment of 5 ACC of the scalp in children, where a family pathology was found.Controlled healing is the best approach for us, even for the serious forms. After the acute period, treatment is based on skin expansion and must be followed by genetic screening of the family.

Ectodermal Dysplasia↗

Management of wounds of exposed or infected knee prostheses.

Skin damage after total knee arthroplasty may jeopardise the functional benefit of the prosthesis. In such cases standard treatment is aimed at avoiding arthrodesis, sometimes replacing the implant and, in exceptional cases, amputation. In most cases early and adequate coverage of the soft tissue defect may make it possible to salvage the prosthesis. Ten patients with skin damage after total knee arthroplasty were treated by debridement of the wound, which was then covered with a pedicled gastrocnemius muscle flap. This was supported by local irrigation and systemic antibiotics. Seven patients were reviewed after a mean follow-up of 28 months (range 14-59). Six patients kept their prostheses and one had a relapse caused by infection at 22 months, which required removal of the prosthesis and secondary arthrodesis. The gastrocnemius muscle flap provides good quality coverage, permits early mobilisation and fast rehabilitation, and reduces the rate of arthrodesis after failure of total knee arthroplasty.

Adult↗

[Reconstruction of the palate vault by free forearm cutaneous flap in oncology].

Surgical reconstruction after partial superior maxillectomy raises a major functional challenge and postoperative recovery implies difficult prosthetic rehabilitation. Between 1989 and 2000, 23 free radial forearm flap reconstruction were performed for palate defects. Twenty-two patients were treated for cancer-related defects and one patient for a non-malignant tumor. Immediate reconstruction was performed in 21 cases and delayed reconstruction in 2. Radiation therapy had been given prior to surgery in 7 patients, Flap necrosis occurred in 2 patients who had surgery alone. Deglutition and phonation outcome was satisfactory in all patients. Trismus was the most frequent complication (7 cases). The free radial forearm flap is the gold standard surgical treatment for superior maxillary defects. In these patients, and exclusive skin flap enables complete reconstruction.

Adult↗

Prion infection impairs the cellular response to oxidative stress.

The molecular mechanism of neurodegeneration in transmissible spongiform encephalopathies remains uncertain. In this study, it was demonstrated that prion-infected hypothalamic neuronal GT1 cells displayed a higher sensitivity to induced oxidative stress over noninfected cells. In addition, the infected cells presented an increased lipid peroxidation and signs of apoptosis associated with a dramatic reduction in the activities of the glutathione-dependent and superoxide dismutase antioxidant systems. This study indicates for the first time that prion infection results in an alteration of the molecular mechanisms promoting cellular resistance to reactive oxygen species. This finding is vital for future therapeutic approaches in transmissible spongiform encephalopathies and the understanding of the function of the prion protein.

Blotting, Western↗

Cleavage of the amino terminus of the prion protein by reactive oxygen species.

Relatively limited information is available on the processing and function of the normal cellular prion protein, PrP(C). Here it is reported for the first time that PrP(C) undergoes a site-specific cleavage of the octapeptide repeat region of the amino terminus on exposure to reactive oxygen species. This cleavage was both copper- and pH-dependent and was retarded by the presence of other divalent metal ions. The oxidative state of the cell also decreased detection of full-length PrP(C) and increased detection of amino-terminally fragmented PrP(C) within cells. Such a post-translational modification has vast implications for PrP(C), in its processing, because such cleavage could alter further proteolysis, and in the formation of the scrapie isoform of the prion protein, PrP(Sc), because abnormal cleavage of PrP(Sc) occurs into the octapeptide repeat region.

Animals↗

Analysis of risk factors for nosocomial sepsis in surgical patients.

BACKGROUND: This study aimed to identify patients at high risk for developing sepsis following surgery according to criteria determined by the American College of Chest Physicians and the Society of Critical Care Medicine Consensus Conference on sepsis. METHODS: A prospective case-control study was performed in surgical patients in a tertiary care centre over 1 year. Patients were identified by a daily prospective surveillance. Controls were selected randomly from the daily list of surgical inpatients. Data were collected prospectively. Crude and adjusted odds ratios (ORs) and their 95 per cent confidence intervals were computed using logistic regression analysis. RESULTS: During follow-up, 99 cases and 99 controls were identified. The main risk factors for sepsis found in the multivariate analysis were coma within 48 h before sepsis (OR 13.5, 95 per cent confidence interval 3.6-50.8), low serum albumin level at admission (OR 15.8, 5.4-46.4), two or more intrinsic co-morbidities (OR 11.8, 2.8-49.4) and parenteral nutrition (OR 5.1, 1.5-17.1). Emergency surgery (OR 3.0, 1.4-6.4), abdominal surgery (OR 2.6, 1.0-6.8) and number of surgical interventions (OR 2.5, 1. 1-6.1) were the variables related to surgery that significantly increased the risk of sepsis. Both the study on the Efficacy of Nosocomial Infection Control (SENIC) and the National Nosocomial Infections Surveillance indices showed a statistically significant trend with sepsis. CONCLUSION: Patient-related factors appear to represent the greatest risk for developing postoperative nosocomial sepsis, rather than factors associated with the surgery.

Case-Control Studies↗

Effect of Congo red on wild-type and mutated prion proteins in cultured cells.

Transmissible spongiform encephalopathies form a group of fatal neurodegenerative disorders that have the unique property of being infectious, sporadic, or genetic in origin. Although some doubts remain on the nature of the responsible agent of these diseases, it is clear that a protein called PrP(Sc) (which stands for the scrapie isoform of the prion protein) has a central role in their pathology. PrP(Sc) represents a conformational variant of a normal protein of the host: the cellular isoform of the prion protein, or PrP(C). Compounds such as glycosaminoglycans and Congo red (CR) have been shown to interfere with both in vitro and in vivo PrP(Sc) formation. It was hypothesized that CR acts by overstabilizing the conformation of PrP(Sc) molecules or by modifying trafficking of PrP(C). Using transfected cells expressing 3F4-tagged mouse PrPs, we show here that CR does not interfere with conversion of PrP molecules carrying pathogenic mutations. On the contrary, after incubation with the drug, some of their properties, such as insolubility and protease resistance, are enhanced and are even acquired by the wild-type molecule. This last observation suggests an alternative mechanism of action of CR and leads us to reconsider the relationship between the biochemical properties of PrP and conformational alteration of the protein.

Animals↗

Effect of amphotericin B on wild-type and mutated prion proteins in cultured cells: putative mechanism of action in transmissible spongiform encephalopathies.

Transmissible spongiform encephalopathies form a group of fatal neurodegenerative disorders that have the unique property of being infectious, sporadic, or genetic in origin. Although some doubts remain on the nature of the responsible agent of these diseases, it is clear that a protein called PrP(Sc) [the scrapie isoform of prion protein (PrP)] plays a central role. PrP(Sc) represents a conformational variant of PrP(C) (the cellular isoform of PrP), the normal host protein. Polyene antibiotics, such as amphotericin B, have been shown to delay the accumulation of PrP(Sc) and to increase the incubation time of the disease after experimental transmission in laboratory animals. Unlike agents such as Congo red, the inhibitory effect of amphotericin B on PrP(Sc) generation has not been observed in infected cultures. Using transfected cells expressing wild-type or mutated mouse PrPs, we show here that amphotericin B is able to interfere with the generation of abnormal PrP isoforms in culture. Its action seems related to a modification of PrP trafficking through the association of this glycosylphosphatidylinositol-anchored protein with detergent-resistant microdomains. These results represent a first step toward the comprehension of the mechanism of action of amphotericin B in transmissible spongiform encephalopathies.

Amphotericin B↗

Successful transmission of three mouse-adapted scrapie strains to murine neuroblastoma cell lines overexpressing wild-type mouse prion protein.

Propagation of the agents responsible for transmissible spongiform encephalopathies (TSEs) in cultured cells has been achieved for only a few cell lines. To establish efficient and versatile models for transmission, we developed neuroblastoma cell lines overexpressing type A mouse prion protein, MoPrP(C)-A, and then tested the susceptibility of the cells to several different mouse-adapted scrapie strains. The transfected cell clones expressed up to sixfold-higher levels of PrP(C) than the untransfected cells. Even after 30 passages, we were able to detect an abnormal proteinase K-resistant form of prion protein, PrP(Sc), in the agent-inoculated PrP-overexpressing cells, while no PrP(Sc) was detectable in the untransfected cells after 3 passages. Production of PrP(Sc) in these cells was also higher and more stable than that seen in scrapie-infected neuroblastoma cells (ScN2a). The transfected cells were susceptible to PrP(Sc)-A strains Chandler, 139A, and 22L but not to PrP(Sc)-B strains 87V and 22A. We further demonstrate the successful transmission of PrP(Sc) from infected cells to other uninfected cells. Our results corroborate the hypothesis that the successful transmission of agents ex vivo depends on both expression levels of host PrP(C) and the sequence of PrP(Sc). This new ex vivo transmission model will facilitate research into the mechanism of host-agent interactions, such as the species barrier and strain diversity, and provides a basis for the development of highly susceptible cell lines that could be used in diagnostic and therapeutic approaches to the TSEs.

Animals↗