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Biomedical subjects

P Mercier

Publications and source records attributed to P Mercier.

At least 19 recordsLinked to original sources
PubMed1992

Recurrent intrinsic brain stem epidermoid cyst.

The authors report the case of a 14-month-old baby boy with an epidermoid cyst located entirely within the pons and medulla, without an exophytic component. The lesion was examined by computed tomography and magnetic resonance imaging. The child was operated upon three times after two recurrences of the lesion. A suboccipital, subtonsillar approach was used for the first and second procedures and a transtemporal approach for the last one. Excision was thought to be complete the first time, since a solid tumor was found and removed in a large cyst. The cyst wall was not identified. No tumor was found during the second procedure despite recurrence of the cyst, which was drained without an attempt to remove the cyst wall. Finally the cyst recurred with a large tumor in the cyst wall which was again totally removed. Consistent with the high mortality of brain stem epidermoid cysts in the literature, the child eventually died. The therapeutic problems, surgical options, and consequences are discussed.

Brain Stem↗
PubMed1992

Multifactorial analysis of the outcome of 6430 cadaver kidney grafts.

A total of 6430 cadaver kidney grafts performed within the network of France-Transplant between 1 January 1978 and 1 January 1989 were analyzed. Each case was examined comprehensively in regard to 12 variables. A multifactorial analysis (Cox regression) was used to determine the degree of association between each covariate and the outcome of the graft. The results were evaluated by calculating relative risks of graft failure for each variable. A total of seven covariates appeared to influence graft survival significantly: the period of transplantation (P = 10(-8)), retransplantations (P = 0.003), age and sex of the donor (P = 0.003 and 0.009 respectively), duration of pretransplant dialysis (P = 0.03), pretransplant sensitization to HLA antigens (P = 0.05), and matching for HLA-A, -B, and -DR loci (P = 0.03). This last parameter has previously been reported as influencing the outcome of the graft in seven out of eight international studies carried out using similar methodology.

Adolescent↗
PubMed1992

A comparative study of the efficacy and morbidity of five techniques for ridge augmentation of the mandible.

Severely atrophic mandibles were augmented in 254 patients using five different surgical procedures, followed by total lowering of the floor of the mouth, vestibuloplasty, and skin graft. Patients were evaluated on a long-term basis to compare efficacy of treatment subjectively by recording patient complaints and by objectively assessing ridge form clinically and radiographically. Patients, in general, were pleased with the short- and long-term results of all five procedures. The ideal ridge form, comma-shaped, was obtained at a much higher rate with the three procedures using hydroxylapatite (HA) alone or in combination with collagen (HA-PFC). Ridge height loss both anteriorly and posteriorly was more severe in the two visor groups with bone graft or with HA than in those with only the alloplast. Labial sensory alterations more frequently occurred in the visor bone graft group, and wound dehiscence and lack of skin graft take were seen most often in the HA-PFC groups. Despite great differences in the quality of ridges obtained and in the number of complications between the visor groups and the alloplast groups, general patient satisfaction with any of the five procedures could be explained by the severity of the original complaints and because muscle interference has been eliminated in all cases by lowering of the floor of the mouth.

Alveolar Ridge Augmentation↗
PubMed1992

Risks and benefits of removal of impacted third molars. A critical review of the literature.

A critical review of the literature about risks and benefits of the removal of impacted 3rd molar teeth is presented in 4 categories: risk of non-intervention, risk of intervention, benefit of non-intervention and benefit of intervention. There are well-defined criteria for removal of impacted 3rd molar teeth. Absolute indications and contra-indications for the removal of asymptomatic 3rd molar teeth cannot be established because no long-term studies exist which validate the benefit to the patient either of early removal or of deliberate retention of these teeth. The prudent course of action for the clinician to follow is based on rational clinical decision-making using traditional methods of evaluation to effect the optimal outcome, keeping the interests of the individual patient above all else.

Humans↗
PubMed1992

Asymptomatic impacted teeth in edentulous jaws undergoing preprosthetic surgery. A long-term evaluation.

A long-term evaluation is made of 15 patients with asymptomatic impacted teeth in edentulous jaws. Seventeen impacted teeth in 15 patients were recorded and analysed. They were located in denture-bearing areas and in areas undergoing preprosthetic surgery. All patients, except one lost after 1-year period, were followed clinically and radiographically for 1 to 10 years with an average of 4 years. The asymptomatic impacted teeth in edentulous jaws embedded in bone or covered with mucosa did not cause any problem to the patients. The findings of this study support the view that removal of asymptomatic impacted teeth in denture-bearing areas, or in areas undergoing preprosthetic surgery, is unnecessary as long as the integrity of the covering tissues is preserved. A policy or radiological surveillance is recommended.

Adult↗
PubMed1992

[Platelet group polymorphism in Provence. Comparison with the frequencies of platelet-specific allo-antigens observed in other populations].

Systems HPA-1 (Pla); HPA-3 (Bak) HPA-5 (Br) are involved in neonatal alloimmune thrombocytopenia and post-transfusion purpura. The frequencies of platelet-specific antigens in these three systems have been studied among one hundred one unrelated blood donors from Provence (South of France) for three generations. Typing was performed by the MAIPA test (monoclonal antibody-specific immobilization platelet antigen). The phenotypes frequencies found were: HPA-1a (PlA1): 97%; HPA-3a (Baka): 88.1%. These frequencies are quite similar to those reported in Europe and North America, but are different compared to Oriental and South American populations. Our Provence population has the highest frequency of HPA-5b (Bra) yet reported: 23.8%. These results define the polymorphism of platelet-specific antigens in the Provence population. Similar studies, among other populations, would provide new data for geographical haematology, which has so far been based on erythrocyte, leucocyte and serum polymorphisms. The variations between populations in these platelet-specific polymorphisms would be so many useful descriptive elements for the epidemiological study of associated diseases.

Blood Donors↗
PubMed1992

Cavernomas of the spinal cord: report of two patients.

Two operated cases of spinal cord cavernomas are presented. Since spinal angiography is usually normal and myelography not specific, the contribution of magnetic resonance imaging to the diagnosis is emphasized. Surgical considerations of treatment are discussed.

Adult↗
PubMed1992

[Paraplegia after surgery of the suprarenal aorta (26 cases reported during a national survey)].

Although their frequency is probably underestimated, medullary complications of abdominal aorta surgery are rare but serious, and may be the cause of medico-legal actions. Referral of a patient allowed the collection of 26 unpublished cases: 18 with aneurysms, including 6 ruptured lesions and 12 undergoing cold surgery, and 8 with aorto-iliac occlusion, these 26 cases representing 0.16% of abdominal aorta interventions performed during the same period. Mortality (6 cases) was due principally to neurological complications, total in 4 cases, partial in 3 and persistent in 13. Risk factors were perioperative collapse (explaining the elevated frequency in ruptured aneurysms) and the occlusion of the internal iliac arteries. Duration of clamping was not significant. No certain method of prevention could be elucidated, either by a literature review or by analysis of the personal series.

Aged↗
PubMed1992

[Risks and benefits of removal of impacted third molars: critical review of the literature. 1].

Because of the ever-increasing enthusiasm that new graduates have demonstrated for practising minor oral surgery procedures, the authors believed that it would be useful to translate the results of a research project done in 1990 by Drs. David S. Precious and Paul Mercier, who are well-known oral and maxillofacial surgeons. This paper is about the risks and benefits associated with the removal of impacted third molars.

Humans↗
PubMed1991

[Calcificated necrotic inflammatory granuloma after intradiscal injection of triamcinolone hexacetonide].

Recently, it has been demonstrated that symptomatic epidural calcifications represent a complication of intradiscal injection of triamcinolone hexacetonide (Hexatrione). Out of our three cases, pathological examination showed lesions of necrosis with granulomatous inflammatory reaction and bone metaplasia. Necrosis seems to be the primary cause of calcifications so we propose to call the lesion inflammatory and necrotic granuloma. The incidence of these granulomas is unknown. They are unpredictable and appear with a mean range of a year following the intradiscal injection. The treatment is surgery if they become symptomatic.

Anti-Inflammatory Agents↗
PubMed1991

[A laxative jam].

A study on the effects of a laxative jam was done on a group of veterans hospitalized at Le Centre hospitalier de l'Université Laval, Sainte-Foy (Québec). The jam, made up of a mixture of dates and prunes, was tried as a form of treatment to see whether it would increase the frequency of bowel movements and decrease laxative use in long-term care elderly patients. Analysis of the treatment group revealed a significant increase in the frequency of bowel movements and a similar decrease in laxative use. No change was observed in the other patients. Although the addition of this jam amounted to a monthly expense of 167$, it has remained part of the diet on a PRN basis.

Aged↗
PubMed1991

[Value of the neuropsychological evaluation in cerebral arterial aneurysms surgically treated].

Early examination (3 months) of 81 patients, operated on for ruptured cerebral aneurysms, by neurosurgeons and neuropsychologists show significant differences between them both; the neuropsychological evaluation has the best predictive value as far as the outcome is concerned especially regarding the return to their initial job (69% after a year in this series). The outcome also depends on the age, the preoperative grade, and the professional qualification. The aneurysm location and the date of the operation are not so important. Early neuropsychological evaluation enable us to start a rehabilitation program for socio professional reinsertion and to improve the quality of life.

Adolescent↗
PubMed1990

Serological analysis of the dissociation process of HLA-B and C class I molecules.

Two forms of HLA class I molecules reacting differentially with the HC-10 monoclonal antibody were identified at the surface of HLA-A3, B7, Cw3 or Cw7 human cells. The HC-10-nonreactive form (which includes all HLA-A3 and a large fraction of HLA-B7, Cw3 and or Cw7 molecules) corresponds to heavy chains apparently tightly associated to beta 2-microglobulin. The HC-10-reactive form (which represents only a fraction of cell surface expressed HLA-B7, Cw3 and Cw7 molecules) corresponds to heavy chains loosely but still associated to beta 2-microglobulin. Further biochemical analyses and the study of mouse transfected cells expressing other HLA class I specificities led to the following conclusions: (a) dissociation of HLA-B and C molecules is a multistep phenomenon, the various stages being identifiable serologically; (b) acquisition of the HC-10 antigenic determinant appears as a hallmark of HLA class I molecules engaged in the process of dissociation; however, its expression does not imply complete separation of heavy and light chains; (c) only the initial stage of the dissociation process can be identified on cell surfaces, whereas (d) following addition of detergent, dissociation of HLA-B and C molecules spontaneously proceeds further, resulting in accumulation in cell lysate of cell surface-derived isolated HLA-B and C class I heavy chains.

Animals↗
PubMed1990

Topographic anatomy of the lumbar lateral vertebral groove. Anatomical basis of the surgical approach to extra foraminal herniated disc.

The study of numerous dissections, sections and X-rays of the lumbar spine has enabled us to clarify the connections of the lumbar spinal nerves at their emergence from the intervertebral foramen and in the lateral vertebral groove. This work naturally leads to the study of the extra foraminal herniated disc by an extra isthmian approach or to percutaneous surgery of thoracolumbar discs.

Humans↗
PubMed1990

[Collagen type IV: major component of basement membranes. Current knowledge].

The collagen family represents the most abundant protein in animals. Type IV collagen ([alpha 1 (IV)]2 alpha 2 (IV)) differs from the other types in several respects and particularly in its distribution, being strictly limited to the basement membranes. Alterations in the structure and functions of basement membranes are observed in a number of diseases, such as tumoral angiogenesis and diabetic nephropathy. This article reviews current structural and pathophysiological knowledge concerning type IV collagen.

Basement Membrane↗