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At least 397 records · Page 22Linked to original sources
PubMed2001

Mandibular reconstruction using microvascular free flaps: a statistical analysis of 178 cases.

For this article, 178 consecutive cases of mandibular reconstruction using microvascular free flaps and performed from 1979 to 1997 were studied. The purpose of this report is to compare flap success rates, complications, and aesthetic and functional results. The ages of the 131 men and 47 women ranged from 13 to 85 years, with an average of 55 years. Donor sites included the rib (11 cases), radius (one case), ilium (36 cases), scapula (51 cases), fibula (34 cases), and soft-tissue flaps with implant (45 cases). Complications included total flap necrosis, partial flap necrosis, major fistula formation, and minor fistula formation. The rate of total flap necrosis involving the ilium and fibula was significantly higher than that of all other materials combined (p < 0.05). The overall rate of implant plate removal, which resulted from the exposure or fracture of the plate, was 35.6 percent (16 of 45 cases). Each mandibular defect was classified by the extent of the bony defect and by the extent of the soft-tissue defect. The extent of the mandibular bony defect was classified according to the HCL method of Jewer et al. The extent of the soft-tissue defect was classified into four groups: none, skin, mucosal, and through-and-through. According to these classifications, functional and aesthetic assessments of deglutition and contour were performed on 115 subjects, and speech was evaluated in 110. To evaluate the postoperative results, points were assigned to each assessment of deglutition, speech, and mandibular contour. Statistical analysis between pairs of bone-defect groups revealed that there was no significant difference in each category. Regarding deglutition, statistical analysis between pairs of soft-tissue-defect groups revealed there were significant differences (p < 0.05) between the none and the mucosal groups and also between the none and the through-and-through groups. Regarding speech, there was a significant difference (p < 0.05) between the none and the through-and-through groups. Regarding contour, there were significant differences (p < 0.01) between the none and the through-and-through groups and between the mucosal and the through-and-through groups. The points given for each function, depending on the reconstruction material, revealed that there was no significant difference between pairs of material groups. From this prospective study, the authors have developed an algorithm for oromandibular reconstruction. When the bony defect is lateral, the ilium, fibula, or scapula should be chosen as the donor site, depending on the extent of the soft-tissue defect. When the bony defect is anterior, the fibula is always the best choice. When the soft-tissue defect is extensive or through-and-through with an anterior bony defect, the fibula should be used with other soft-tissue flaps.

Adolescent↗
PubMed2000

Depression in the level of cadherin and alpha-, beta-, gamma-catenins in transgenic Xenopus laevis highly expressing c-Src.

Aberrant morphogenesis of transgenic Xenopus laevis 5-day embryos carrying Rous sarcoma virus LTR in their DNA and expressing a high level of c-Src protein kinase was found to be accompanied with a profound depression in the level of cadherins and alpha-, beta-, and gamma-(plakoglobin) catenins in their tissues, as revealed by immunohistochemical analysis. Simultaneously, an increased level of phosphotyrosine staining was detected. However, an analogous increase in the level of phosphotyrosine immunostaining and a slightly higher level of Src were also detected in tissues of originally defective but later spontaneously repaired frog embryos that displayed essentially normal patterns of staining for cadherins and catenins. Our results provide evidence that the defective morphogenesis of frog embryos expressing a high level of c-Src is characterized by the loss of the cadherin-catenin complexes. It appears that to induce frog morphogenetic malformations, the c-Src overproduction and the loss of cadherins-catenins are simultaneously required. Phosphorylation is not likely to be the cause of cadherin and catenin disappearance from the tissues of strongly aberrant frog embryos.

Abnormalities, Multiple↗
PubMedDate not supplied

Lateral calcaneal artery flap for coverage of a posterior heel defect in a child.

The lateral calcaneal artery fasciocutaneous transpositional flap is utilized for coverage in a case presentation of a 6-year-old child with an insensate posterior heel defect. The procedural technique and 32-month follow-up is described. Advocacy of this flap, for this patient, and potential detriments of alternative coverage options are discussed.

Child↗
PubMed1999

Mutation spectrum of ATP7A, the gene defective in Menkes disease.

Our knowledge about Menkes disease (MD) has expanded greatly since its description in 1962 as a new X-linked recessive neurodegenerative disorder of early infancy. Ten years later a defect in copper metabolism was established as the underlying biochemical deficiency. In the beginning of 1990s efforts were concentrated on the molecular genetic aspects. The disease locus was mapped to Xq13.3 and the gene has been isolated by means of positional cloning. This was the beginning of a series of new findings which have greatly enhanced our understanding of copper metabolism not only in human, but also in other species. This review will focus on the molecular genetic aspects of Menkes disease and its allelic form occipital horn syndrome. The mutations will be compared briefly with those described in the animal model mottled mouse, and in Wilson disease, the autosomal recessive disorder of copper metabolism.

Adenosine Triphosphatases↗
PubMed1988

Discordant uptake of technetium-99m DISIDA and technetium-99m sulfur colloid in an amebic abscess.

Hepatobiliary imaging in a patient with an amebic abscess showed an early cold defect that later showed rim enhancement. A Tc-99m SC scan did not show prominent flow (making hepatoma unlikely) and showed the previously noted defect to appear larger and without rim enhancement. The differential damage to Kupffer cells and hepatocytes or edema may account for these findings. Amebic abscess should be included in the differential diagnosis of lesions that give increased Tc-99m IDA but cold Tc-99m SC images.

Adult↗
PubMed2004

nip, a symbiotic Medicago truncatula mutant that forms root nodules with aberrant infection threads and plant defense-like response.

To investigate the legume-Rhizobium symbiosis, we isolated and studied a novel symbiotic mutant of the model legume Medicago truncatula, designated nip (numerous infections and polyphenolics). When grown on nitrogen-free media in the presence of the compatible bacterium Sinorhizobium meliloti, the nip mutant showed nitrogen deficiency symptoms. The mutant failed to form pink nitrogen-fixing nodules that occur in the wild-type symbiosis, but instead developed small bump-like nodules on its roots that were blocked at an early stage of development. Examination of the nip nodules by light microscopy after staining with X-Gal for S. meliloti expressing a constitutive GUS gene, by confocal microscopy following staining with SYTO-13, and by electron microscopy revealed that nip initiated symbiotic interactions and formed nodule primordia and infection threads. The infection threads in nip proliferated abnormally and very rarely deposited rhizobia into plant host cells; rhizobia failed to differentiate further in these cases. nip nodules contained autofluorescent cells and accumulated a brown pigment. Histochemical staining of nip nodules revealed this pigment to be polyphenolic accumulation. RNA blot analyses demonstrated that nip nodules expressed only a subset of genes associated with nodule organogenesis, as well as elevated expression of a host defense-associated phenylalanine ammonia lyase gene. nip plants were observed to have abnormal lateral roots. nip plant root growth and nodulation responded normally to ethylene inhibitors and precursors. Allelism tests showed that nip complements 14 other M. truncatula nodulation mutants but not latd, a mutant with a more severe nodulation phenotype as well as primary and lateral root defects. Thus, the nip mutant defines a new locus, NIP, required for appropriate infection thread development during invasion of the nascent nodule by rhizobia, normal lateral root elongation, and normal regulation of host defense-like responses during symbiotic interactions.

Alleles↗
PubMedDate not supplied

Concurrent percutaneous atrial septal defect closure and pulmonary valvuloplasty.

Severe pulmonary valve stenosis in association with a large atrial septal defect is uncommon. Simultaneous percutaneous closure of the atrial septal defect and pulmonary valvuloplasty appears to be an attractive modality when compared to patients with these two lesions being subjected to surgery or being treated percutaneously at different sittings. We encountered two cases, both with significant pulmonary valvular stenosis associated with atrial septal defect (fossa ovalis type). Both lesions were successfully treated percutaneously in the same sitting. Pulmonary valvuloplasty was done initially and the atrial septal defect closed later to minimize catheter manipulation after device implantation.

Adolescent↗
PubMed1998

Cranioplasty with split lateral skull plate segments for reconstruction of skull defects.

This paper reports the use of cranioplasty using segments of split lateral skull plate to correct large skull defects (larger than 8 x 8 cm). The subjects consisted of 10 patients with head trauma who had undergone decompression surgery, and two patients who had undergone tumour resection. Bone grafts were obtained by cutting approximately 2 cm wide strips from the lateral skull plate using a bone saw that was inserted from a free margin of the bone defects. By cutting strips laterally from the bone defect, the necessary amount of split lateral skull plate can be obtained without performing craniotomy. The pieces of split lateral skull plate are then fixed to the defect using wire or titanium mini-plates. At this point, the selection of bone grafts that match the curvature of the dura mater is important, so that no dead spaces are created between the dura mater and the bone grafts. Infection was not detected in any of the 12 patients, and all bone grafts took completely. One of the 12 patients suffered from a pathological fracture and bone resorption 6 months after surgery. The fracture occurred because the use of basket-shaped reconstruction plates resulted in large spaces between the plate segments, and in addition the intracranial pressure was kept low by a V-P shunt, thus rendering the patient more vulnerable to atmospheric pressure.

Adolescent↗
PubMed2006

Porous gelatin-chondroitin-hyaluronate tri-copolymer scaffold containing microspheres loaded with TGF-beta1 induces differentiation of mesenchymal stem cells in vivo for enhancing cartilage repair.

The aim of the study was to produce a novel porous gelatin-chondroitin-hyaluronate scaffold in combination with a controlled release of transforming growth factor beta1 (TGF-beta1), which induced the differentiation of mesenchymal stem cells (MSCs) in vivo for enhancing cartilage repair. Gelatin microspheres loaded with TGF-beta1 (MS-TGFbeta1) showed a fast release at the initial phase (37.4%), and the ultimate accumulated release was 83.1% by day 18. The autologous MSCs seeded on MS-TGFbeta1/scaffold were implanted to repair full-thickness cartilage defects in rabbits as in vivo differentiation repair group, while MSCs differentiated in vitro were seeded on scaffold without MS-TGFbeta1 to repair the contra lateral cartilage defects (n = 30). Fifteen additional rabbits without treatment for defects were used as control. Histology observation showed that the in vivo differentiation repair group had better chondrocyte morphology, integration, continuous subchondral bone, and much thicker newly formed cartilage layer when compared to in vitro differentiation repair group 12 and 24 weeks, postoperatively. There was a significant difference in histological grading score between these two experimental groups, and both showed much better repair than that of the control. The present study implied that the novel scaffold with MS-TGFbeta1 might serve as a new way to induce the differentiation of MSCs in vivo to enhance the cartilage repair.

Animals↗
PubMed2003

Microarchitecture of rabbit mandibular defects grafted with intramembranous or endochondral bone shown by micro-computed tomography.

The aim of this study was to assess the integration of intramembranous and endochondral autogeneous bone grafts into membranous bony defects, by analysing the microarchitectural changes of the grafted bone 3 months after grafting. Twelve critical size defects (15 x 10mm) were created in rabbit mandibles bilaterally. Six defects on the right side of the mandible were grafted with autogenous endochondral bone, and six on the left were grafted with intramembranous bone. Three months later, the defects were retrieved for imaging with micro-computed tomography (Micro-CT) and for radiographic and histological evaluation. Micro-CT showed that intramembranous bone gave more bone volume a larger, trabecular number and trabecular thickness (P<0.001), and that endochondral bone had more trabecular separation (P<0.001). These findings indicate that intramembranous bone grafts integrate better than endochondral bone grafts in three-dimensions when they are grafted into membranous bony defects.

Animals↗
PubMed1989

Relationship between the radiographic periodontal defect angle and healing after treatment.

This study radiographically evaluated the correlation between the changes in alveolar bone level occurring in bony defects after periodontal therapy and the corresponding pretreatment defect angles. The defect angle was defined by the bony defect surface and the root surface. The changes were determined from identically exposed and processed radiographs obtained just prior to surgery and 15 to 18 months later. The defect angle was clearly correlated to the radiographic changes in alveolar bone level. Most defects with an angle less than 45 degree showed a gain of bone while defects with the largest defect angles showed a loss. In addition, defects on root surfaces without furcations showed better healing than defects associated with furcations.

Alveolar Process↗
PubMed1989

Reconstruction of large diaphyseal defects, without free fibular transfer, in Grade-IIIB tibial fractures.

Eight Grade-IIIB tibial fractures that were associated with large soft-tissue and segmental diaphyseal defects, averaging ten centimeters in length, were successfully reconstructed without the use of a free fibular transfer. A free tissue flap was the preferred form of soft-tissue coverage. The osseous reconstruction was accomplished by using a massive amount of autogenous cancellous bone graft. Beads that were made from polymethylmethacrylate and impregnated with two antibiotics at the time of operation were used as soft-tissue spacers to preserve the volume of the diaphyseal defect for later receipt of the cancellous bone graft. The beads prevented the soft-tissue flap from collapsing into and adhering to the site of the tibial defect. The beads also served as vehicles for local delivery of the antibiotics that they contained. When the soft-tissue flap had healed, the beads were replaced with cancellous graft. All of the tibiae healed. The time to healing averaged nine months. The average duration of external fixation was 5.5 months. One deep infection developed, but resolved after debridement and antibiotic therapy. This conservative technique is safe and reliable for patients who have sustained a high-energy tibial fracture and a large segmental diaphyseal defect.

Adolescent↗
PubMed2004

MASSUGU2 encodes Aux/IAA19, an auxin-regulated protein that functions together with the transcriptional activator NPH4/ARF7 to regulate differential growth responses of hypocotyl and formation of lateral roots in Arabidopsis thaliana.

We have isolated a dominant, auxin-insensitive mutant of Arabidopsis thaliana, massugu2 (msg2), that displays neither hypocotyl gravitropism nor phototropism, fails to maintain an apical hook as an etiolated seedling, and is defective in lateral root formation. Yet other aspects of growth and development of msg2 plants are almost normal. These characteristics of msg2 are similar to those of another auxin-insensitive mutant, non-phototropic hypocotyl4 (nph4), which is a loss-of-function mutant of AUXIN RESPONSE FACTOR7 (ARF7) (Harper et al., 2000). Map-based cloning of the MSG2 locus reveals that all four mutant alleles result in amino acid substitutions in the conserved domain II of an Auxin/Indole-3-Acetic Acid protein, IAA19. Interestingly, auxin inducibility of MSG2/IAA19 gene expression is reduced by 65% in nph4/arf7. Moreover, MSG2/IAA19 protein binds to the C-terminal domain of NPH4/ARF7 in a Saccharomyces cerevisiae (yeast) two-hybrid assay and to the whole latter protein in vitro by pull-down assay. These results suggest that MSG2/IAA19 and NPH4/ARF7 may constitute a negative feedback loop to regulate differential growth responses of hypocotyls and lateral root formation.

Amino Acid Sequence↗
PubMed1990

Parascapular free flaps for head and neck reconstruction.

We report our experience with single-stage, primary reconstruction of the head and neck in 29 consecutive patients using parascapular free flaps. The commonest indications were for craniofacial defects (9), oropharyngeal soft tissue defects (10), and combined mandibular and soft tissue losses (4). Ablative surgery was performed for squamous carcinoma (22), melanoma (2), and malignant fibrous histiocytoma (2). Seven patients died of recurrent disease during a 3 1/2 year follow-up. Seven patients are alive with recurrence. Flap complications included total loss (2) due to unsalvageable microvascular thrombosis, wound breakdown with oropharyngeal fistula (2), mandibular osteomyelitis (1), trismus (2), neck contracture (1), and donor site wound dehiscence (1). The overall success of this reconstruction was 93%. Primary wound healing was the general rule with lower morbidity than with other reconstructive techniques. The flap is thin, pliable, and conforms well to three-dimensional defects. The lateral border of the scapula can be incorporated on the same vascular pedicle for single-stage mandibular reconstruction. No muscle is sacrificed, and the posterior donor defect is an added advantage. The parascapular flap is our first choice for reconstruction of major defects in the head and neck.

Adult↗
PubMed2003

Microvascular flap reconstruction of the mandible: a comparison of bone grafts and bridging plates for restoration of mandibular continuity.

OBJECTIVE: To compare the efficacy of vascularized bone grafts and bridging mandibular reconstruction plates for restoration of mandibular continuity in patients who undergo free flap reconstruction after segmental mandibulectomy. Study design and setting A total of 210 patients underwent microvascular flap reconstruction after segmental mandibulectomy. The rate of successful restoration of mandibular continuity in 151 patients with vascularized bone grafts was compared to 59 patients with soft tissue free flaps combined with bridging plates. RESULTS: Mandibular continuity was restored successfully for the duration of the follow-up period in 94% of patients who received bone grafts compared with 92% of patients with bridging mandibular reconstruction plates. This difference was not statistically significant. In patients who received bone grafts, most cases of reconstructive failure occurred during the perioperative period and were due to patient death or free flap thrombosis. In patients who received bridging plates, all instances of reconstructive failure were delayed for several months and were due to hardware extrusion or plate fracture. CONCLUSIONS: Vascularized bone-containing free flaps are preferred for reconstruction of most segmental mandibulectomy defects in patients undergoing microvascular flap reconstruction. However, use of a soft tissue flap with a bridging mandibular reconstruction plate is a reasonable alternative in patients with lateral oromandibular defects when the nature of the defect favors use of a soft tissue free flap. SIGNIFICANCE: Both bone grafts and bridging plates represent effective methods of restoring mandibular continuity following segmental mandibulectomy, with the former being the preferred technique for patients undergoing microvascular reconstruction.

Adult↗
PubMed2004

Biomechanical evaluation of fixation techniques for bridging segmental mandibular defects.

OBJECTIVE: To compare biomechanical properties of currently available plating systems used to reconstruct segmental mandibular defects. DESIGN: Controlled in vitro investigation. SETTING: Academic medical center laboratory. INTERVENTIONS: Thirty-two polyurethane mandibles were equally divided among 4 groups: mandibles with a 4-cm lateral segmental defect that was bridged with a (1) 3.0-mm locking-screw reconstruction plate, (2) 2.4-mm low-profile reconstruction plate, or (3) 2.4-mm reconstruction plate and (4) uncut (control) mandibles. All plates were contoured and secured to the synthetic mandibles with 4 bicortical screws on either side of the defect. Three constructs from each group were subjected to contralateral-molar single-load-to-failure testing. Mean yield displacement, yield load, and bending stiffness were quantified and compared among the 4 groups. The single-load-to-failure data were used to establish conditions for fatigue testing; such testing was then performed on the remaining 5 samples in each group. Mean cycles to failure were measured and compared among the 4 groups. RESULTS: Mean yield displacement, yield load, and bending stiffness were comparable among the plated groups. Both the 3.0-mm locking-screw and 2.4-mm low-profile reconstruction plate designs withstood 1580 and 1124 times more cycles to failure, respectively (P = .005), than did the control group. The other reconstruction plate was also superior to the unplated controls, offering an 865-fold improvement. CONCLUSIONS: All 3 mandibular fixation device systems tested produce comparable levels of single load to failure biomechanical integrity; however, the higher-profile plating system design offered slightly superior fatigue performance. No differences in performance were observed between the locking and nonlocking designs; neither failed at the screw-substrate interface.

Biomechanical Phenomena↗
PubMed1996

Aberrant mammary tissue and nephrourinary malignancy.

Polythelia (supernumerary nipple) provides a clue to congenital and hereditary malformations of the kidney and the urinary collecting system. It is also regarded as a cutaneous paraneoplastic marker because of the significant association with urogenital malignancies. A 38-year-old man with sporadic left supernumerary nipple without evidence of ear, facies, or gonadal defects or lateral displacement of the nipples was routinely examined for the presence of renal anomalies. Investigation revealed left polycystic kidney disease with adenocarcinoma in the upper pole. The nephrocutaneous defects and renal malignancy showed a peculiar ipsilaterality. The overlap between polythelia, polycystic kidney disease with adenocarcinoma in the upper pole. The nephrocutaneous defects and renal malignancy showed a peculiar ipsilaterality. The overlap between polythelia, polycystic kidney, and renal adenocarcinoma may provide a further clue to the embryonal origin of this cancer.

Adenocarcinoma↗