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Biomedical subjects

G Guillemin

Publications and source records attributed to G Guillemin.

At least 19 recordsLinked to original sources
PubMed1991

[Prevention of substance loss in an edentulous site: report of case combining gingival graft and coral particles].

Ridge collapse is often seen after tooth extraction and grafting procedure is used in this technique. This case report presents, after block section of two maxillary incisors, the use of an occlusal epithelio-connective tissue graft, followed by grafting of coral particles. Clinical results, six months post-operatively, show a total maintenance of edentulous ridge volume and height. A biopsy at the same interval shows fibrous tissue surrounding coral particles, giant cells in some areas, but also some areas of calcification.

Adult↗
PubMed1989

Comparison of coral resorption and bone apposition with two natural corals of different porosities.

Previous studies showed that natural coral implanted into bone tissue was gradually resorbed and progressively replaced by newly formed bone. The objectives of this study were to compare the fate of two Madreporian corals, Porites and Acropora, after implantation during 1 and 2 months into sheep and pig long bones. These materials are identical in composition (CaCo3) but differ in volume (49 +/- 2%, 12 +/- 4%, respectively) and mean size (250 vs. 500 microns) of porosities. The non-decalcified histological slices were observed under light microscopy. Implant resorption and new bone formation were quantified through an automatic image analysis system. Quantitative results showed that the larger the porosity volume, the greater was the coral resorption as well as the new bone apposition. Large differences were found between the two animal species. Histological findings were identical to those previously reported: implants were resorbed and progressively replaced by newly formed bone. Coral was found to be an osteoconductive biomaterial which acted as a scaffold for a direct osteoblastic apposition and consequently could be an interesting alternative to bone auto-, allo-, or xenografts.

Animals↗
PubMed1989

[Natural coral used as a replacement biomaterial in bone grafts].

Natural coral, submitted to rigorous protocols of preparation and purification, can be used as a replacement biomaterial for bone grafts both in orthopaedic surgery and maxillo-cranio-facial surgery and neurosurgery. Experimental studies commenced in 1977 and human clinical applications, commenced in 1979, have largely demonstrated the biocompatibility of the material and its entirely original nature. This biomaterial is progressively and totally replaced by newly formed bone with, after completion of the restoration process, has the characteristics of the recipient bone.

Animals↗
PubMed1989

[Coral substituted for bone grafting in posterior vertebral arthrodesis in children. Initial results].

The authors used natural coral as a substitutive element to bone supply in children in need of posterior vertebral graft. The use of natural coral was part of a protocol aiming at diminishing peroperative bleeding, and as far as possible, at doing away with resorting to homotransfusion. After reviewing the biological, experimental and clinical bases, the authors studied 49 cases of posterior vertebral fusion instrumented with the Cotrel-Dubousset device and with natural coral grafts. Results were appraised with X-ray in all cases, 5 times with scintigraphies and 7 times with biopsies and were encouraging: coral behaves quite similarly to the usual bone graft. From their experience the authors describe how coral is to be used and consider that the use of this substitutive element should spread in the future under various forms.

Animals↗
PubMed1988

Madreporic coral: a new bone graft substitute for cranial surgery.

Since 1985, the authors have been using madreporic coral fragments (genera Porites) as a bone graft substitute. Of the 167 coral grafts implanted, 150 were coral "corks" used to obliterate burr holes (diameter 10 mm), five were large implants (length 20 to 40 mm) to repair skull defects, and 12 were coral blocks to reconstruct the floor of the anterior cranial fossa. Previous experimental studies suggested that coral grafts would be well tolerated and become partially reossified as the calcific skeleton was resorbed. The authors describe their experience and detail the main biological properties of these materials, which appear to be very promising for use in cranial reconstructive surgery.

Animals↗
PubMed1988

[The coefficient of saturation of iron in transferrin].

Theoretical iron fixation capacity of transferrin (FCT) can be calculated on its immunochemical titration: (FCT (mumol/l = transferrin (g/l) x 25). Today, its reckoning is more advisable to serum total iron binding capacity measurement. The authors studied the effects of this new proceeding upon usual values interval of transferrin saturation (i.e. serum iron/FCT ratio). The mean value and the distribution of transferrin saturation appear displaced with regard to those achieved by chemical measurement of serum total iron binding capacity. We discuss interpretation of transferrin saturation related to its methods of determination and its semiological interest.

Adolescent↗
PubMed1988

[Reconstruction of the anterior face of the base of the skull using coral grafts].

Following experimental investigations on animals, small coral grafts have been utilized on patients since 1985 to fill in burr holes (42 patients). This first clinical experimental step has been satisfactory. Therefore, blocks of corals have since then been used as bone graft substitutes for anterior skull basis reconstruction (12 patients). Cheap and easily sterilized, coral implants have the advantage of being inert (99% of calcium carbonate), biodegradable and well reossified. They shorten surgical procedures by avoiding the use of iliac and/or costal grafts. No infectious complications have been noted.

Biocompatible Materials↗
PubMed1987

The use of coral as a bone graft substitute.

Experiments have been performed to investigate the use of coral skeletons as bone graft substitutes. Skeletal fragments of different coral genera were implanted into cortical and spongy bone defects and used to bridge transcortical resections in the femur. The implant site was monitored for up to 18 months. Radiographically, both cortical and spongy bone defects were at least partially filled by new bone after 8 weeks while the implants underwent continuous resorption. Coral resorption and replacement by new tissue was also observed in the transcortical resections. The process of resorption was attributed to the enzymatic attack, especially carboanhydrase. This was confirmed by experiments in which dogs were implanted with coral in transcortical resections and treated daily with acetazolamide, a carboanhydrase inhibitor; the absorption appeared delayed and the resections failed to heal.

Acetazolamide↗
PubMed1983

[Anterior resection for cancer of the middle third of the rectum, though always possible, is it desirable?].

Description with details of an operative procedure for anterior resection (A.R.) of rectal carcinoma, with low colorectal anastomosis using circular stapling device. It is quite always possible. Is it desirable? The number of local and regional recurrencies after A.R. for Dukes B and C carcinomas of the mid third of the rectum, higher than in case of Miles operation, incite to ask the question. The five year survival being the same in the two groups make the answer uneasy, regarding handicaps induced by Miles operation. Would, the association to A.R. of pre-operative radiotherapy and/or immunotherapy, be one step to the solution?

Colon↗
PubMed1983

[Determination of erythrocyte sorbitol].

An increase in the intra-cellular concentrations of sorbitol can be responsible, at least in part, for certain long term complications of diabetes. Since the erythrocyte concentration of this polyol is a good indicator of that of other cells, we propose a simple, rapid enzymatic assay technique for red blood cells. The results already obtained reveal a significant difference between the erythrocyte sorbitol concentration in non-diabetic subjects and that in diabetic patients.

Adult↗
PubMed1981

[Fate of a fragment of madrepore coral skeleton implanted in the diaphysis of long bones in dogs].

A madrepore fragment implanted into Dog's long bone diaphysis is quickly vascularized and then progressively resorbed; this is due to an osteoclasic action. At the same time, in replacement of resorbed coral, cancellous bone grows which progressively let the place to compact bone. Injections of diamox given to formerly implanted Dogs, slacken the resorption of coral implants which seems to be the work of carbonic anhydrase contained in osteoclasts.

Absorption↗