Biomedical subjects

J C de Vicente

Publications and source records attributed to J C de Vicente.

6 recordsLinked to original sources

PubMed2006

Histomorphometric evaluation of guided bone regeneration around implants with SLA surface: an experimental study in beagle dogs.

The aim of this study was to evaluate the efficacy of collagen membranes, either alone or combined with a human demineralized freeze-dried bone allograft (DFDBA) or natural bovine bone graft, in bone defects around dental implants with an SLA (sand-blasted, large grit, acid-etched) surface. The experiments were carried out in three beagle dogs using a split-mouth design. On one side of the jaw, three implants were placed and intra-bony defects were created and covered with a collagen membrane, randomly combined in two of the defects with human DFDBA or inorganic bovine bone graft. A control implant, without membrane covering or defect filling, was also placed. On the other side of the jaw, three implants were placed and the bone defects were treated in a similar fashion, but without membrane covering. The studied variables were the percentage of bone-to-implant contact within the limits of the initial bony defect and percentage of the original bony defect occupied by bone tissue. Although no statistically significant differences were found in this study between the membrane and nonmembrane groups, bone defects augmented with anorganic bovine bone and membranes showed the most promising results from a histological and histomorphometric perspective.

Animals↗

PubMed2002

Impaired dental cytodifferentiation in glial cell-line derived growth factor (GDNF) deficient mice.

Glial cell line-derived neurotrophic factor promotes the survival of multiple neuron types in the central and peripheral nervous system. Moreover, it plays a key role in the development of the enteric nervous system and in the kidney organogenesis. Glial cell line-derived neurotrophic factor and their receptors are expressed in the developing tooth as well as in the trigeminal ganglion. However, the precise role of this growth factor in tooth morphogenesis and cell differentiation, or in the development of trigeminal ganglion cells, is still elusive. Using structural and ultrastructural techniques we analyzed in detail the first molar tooth germ of glial cell line-derived neurotrophic factor deficient mice as well as the neuronal density in trigeminal ganglion. The length and width of first molar tooth germ in knockout deficient animals showed no differences in the knockout animals in comparison with age-matched heterozygous or wild-type littermates. Nevertheless, in mice lacking glial cell line-derived neurotrophic factor, both ameloblasts and odontoblasts failed to fully develop and differentiate, and the enamel matrix and predentin layers were absent. On the other hand, the number of trigeminal sensory neurons and the structure of the nerves supplying first molar tooth germ were largely normal. Present results suggest a new non-neuronal role for glial cell line-derived neurotrophic factor in tooth development. Glial cell line-derived neurotrophic factor seems not to be involved in tooth initiation and morphogenesis, whereas it seems essential for cytodifferentiation. Conversely, neither development of trigeminal neuron nor nerve fibers supplying teeth are directly dependent on glial cell line-derived neutrophic factor.

Animals↗

PubMed2000

Traumatic optic neuropathy. A case report.

A case of visual loss following cranio-maxillofacial trauma is reported. The patient had a sudden partial blindness associated with a fracture of the roof, medial and lateral orbital walls. Access to the orbit was achieved through a transethmoidal approach using the Howarth-Lynch medial incision and resecting the bone fragments which impinged on the optic nerve. The patient had total return of visual acuity, without surgical complications. The role of orbital and optic decompression in the management of patients with traumatic optic neuropathy is discussed. Its indications are controversial and the procedure should be considered only within the context of the specific needs of the individual patient.

Adolescent↗

PubMed1998

Bone regeneration after radicular cyst removal with and without guided bone regeneration.

In order to determine the degree of bone regeneration after removal of radicular cysts using guided bone regeneration (GBR), a prospective, controlled and randomized clinical study was performed. Thirty patients with radicular cysts were divided into three groups. One group, the control group (n=10 patients), was treated by enucleation and primary closure. The other two groups were treated by enucleation and primary closure but GBR was used in addition, using a resorbable membrane (n=10) and a nonresorbable membrane (n=10). The membranes were fixed with nonresorbable Memfix System screws. The residual volume and the density of the newly formed tissue was measured by computer-assisted tomography and computer-assisted digital image analysis before enucleation and three and six months postoperatively. No statistical significance was found in density and residual volume between the three treatment groups after six months. These results suggest that GBR using membranes does not contribute to increased bone regeneration.

Adult↗

PubMed1997

Granular-cell tumours: an immunohistochemical study.

The granular cell tumour (myoblastoma, Abrikosoff's tumour) and the congenital epulis in newborns (Neumann tumour) are two lesions rarely found in the oral cavity, whose histogenetic origin is highly controversial. This work analyses using immunohistochemical techniques 15 cases of myoblastomas and two of congenital epulis with different mono- and poly-clonal antibodies. Positive immunostaining was found for S-100 protein and neuron-specific enolase in all the cases of myoblastoma, and for vimentin and carcinoembryonic antigen in some cases. No immunoreactivity was observed for any of the other 13 antibodies used in congenital epulis.

Actins↗

PubMedDate not supplied

[Intrathecal baclofen for children with chronic pain related to severe spasticity: advantages of tunneling the catheter in the testing phase].

OBJECTIVE: To document the effectiveness and safety of intrathecal baclofen administered through a tunneled catheter during a diagnostic procedure, prior to implantation of a subcutaneous pump, in children with chronic pain due to severe spasticity. METHODS: This was a retrospective study of 6 children with intense chronic pain due to spasticity caused by cerebral palsy or genetic dystonia. Increasing doses of intrathecal baclofen in continuous perfusion through a tunneled catheter were tested. RESULTS: Lumbar intrathecal catheters were tunneled for 48 to 80 hours in 5 males and 1 female aged 8 to 18 years old. Intrathecal baclofen was administered in continuous perfusion up to maximum rates that ranged between 105 and 570 microg/day. For 5 patients the score on the visual analog pain scale (0-10) changed from over 7 to 0 by the end of the test. In 2 patients, side effects of analgesia were noted, specifically sedation, bradycardia, and bradypnea. No serious complications, such as meningitis, spinal abscess, or hematoma, were reported. The families of 4 patients chose to accept implantation of a subcutaneous pump. Pump therapy remained effective and free of complications when checked 23 or 55 months after placement. CONCLUSIONS: Performing a trial of increasing doses of intrathecal baclofen therapy in continuous perfusion through a tunneled catheter facilitated selection of patients for whom chronic administration of intrathecal baclofen is effective and free of complications.

Adolescent↗