Microsurgical reconstruction for caustic injuries of the oral cavity and esophagus

Ingestion of caustic material often produces profound and irreversible pathologic changes that require reconstructive surgery of the organs damaged. This report describes the authors' successful experience with microsurgical techniques that allowed adequate reconstruction in three patients with cicatricial contracture of the oral cavity and esophagus following ingestion of caustic substances. All patients had attempted suicide by ingesting liquid alkali. Patients #1 and #2 complained of limited mouth opening and impaired tongue movement due to oral scar contracture. Contracture release in the first patient resulted in a defect from the anterior border of the mandible to the retromolar region. The defect was resurfaced with a 6 x 12 cm free forearm flap. Release of the scar contracture in the second patient resulted in a long, narrow, tortuous defect that was difficult to cover, even with a forearm flap, and a jejunal segment was microsurgically transferred as a patch graft to reconstruct the defect. Patient #3 had dysphagia due to stricture of the cervical portion of the esophagus. The defect after resection of the cervical portion was reconstructed by free jejunal interposition. Appropriately selected free-flap transfer in each case provided a satisfactory restoration of function of the oropharyngeal and digestive passages.     

Endocannabinoid system modulates relapse to methamphetamine seeking: possible mediation by the arachidonic acid cascade.

We clarified the modulating action of the endocannabinoid system, and its possible mediation by the arachidonic acid cascade, on the reinstatement of methamphetamine (METH)-seeking behavior, using the intravenous self-administration paradigm in rats. Following 12 days of self-administration of METH, the replacement of METH with saline resulted in a gradual decrease in lever press responses (extinction). Under extinction conditions, METH-priming or re-exposure to cues previously paired with METH infusion markedly increased the responses (reinstatement of drug-seeking). The cannabinoid CB1 receptor antagonist, SR141716A, blocked this behavior. Although the cannabinoid agonist, Delta8-tetrahydrocannabinol (THC), had no effects by itself, coadministration of the agonist and METH at small doses reinstated the drug-seeking behavior. THC attenuated the effects of the reinstatement-inducing dose of METH, but enhanced the effect of cues. Either given repeatedly during the extinction or singly, 24 h before the first METH-priming or cues challenge, THC suppressed the reinstatement. In another set of experiments, we found that diclofenac, a cyclooxygenase inhibitor, also attenuated the reinstatement induced by exposure to cues or drug-priming. These results suggest that the endocannabinoid system, through possible mediation by the arachidonic acid cascade, serves as a modulator of the reinstating effects of METH-priming and cues. Extending the current view on the treatment of drug dependence, these results indicate that endocannabinoid-activating substances as well as cyclooxygenase inhibitors may be promising as antirelapse agents.     

Conduction performance of collateral vessels induced by vascular endothelial growth factor or basic fibroblast growth factor

OBJECTIVE: In the present study, we delivered vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) gene to a rabbit model of hind limb ischemia utilizing an ex vivo method of gene transfer, and evaluated the functional performance of the developed collateral vessels. METHOD: The left femoral artery of a male Japanese White rabbit was excised to induce limb ischemia, and a section of skin was resected for culture of auto-fibroblasts. Twenty days later, the VEGF gene, bFGF gene or beta-galactosidase gene (LacZ) was adenovirally transferred to the cultured auto-fibroblasts (5x10(6) cells), and the next day, a pair of specifically infected fibroblasts (total 1x10(7) cells) was injected via the left internal iliac artery of the same rabbit. Pairs of transferred genes into the fibroblasts were as follows: LacZ/LacZ (control group), VEGF/LacZ (VEGF group), bFGF/LacZ (FGF group) and VEGF/bFGF (combination group). Twenty-eight days after cell administration, collateral development and its function were evaluated. RESULTS: Calf blood pressure ratio, resting blood flow of the left iliac artery and capillary density of ischemic muscle showed similar degrees of angiogenic effects in the VEGF and FGF groups, which were significantly greater than those in the control group. On the contrary, angiographic score, collateral conductance and smooth muscle cell (SMC)-positive vessel density in the FGF group were significantly greater than those in the VEGF group. In the combination group, collateral conductance showed synergistic effects, and in vivo blood flow and smooth muscle cell-positive vessel density revealed additive effects of VEGF and bFGF. CONCLUSION: These findings suggested that bFGF-induced collateral development exceeded VEGF-induced collateral development in the induction of arteriogenesis, and that combined gene delivery of VEGF and bFGF produced additive or synergistic effects of collateral development as compared with the effects induced by transfer of each gene alone.     

Recent trends in cartilage regenerative medicine and its application to oral and maxillofacial surgery

Greater progress has been made in the clinical application of cartilage regenerative medicine, compared with that of other organs. A typical example of cartilage regenerative medicine is autologous chondrocyte implantation, in which chondrocytes isolated from the patient's cartilage are cultured and injected into the cartilage defects in a liquid- or gel-form. However, the classic autologous chondrocyte implantation has been applicable to only limited diseases, including focal cartilage lesion. Therefore, we developed “implant-type” tissue-engineered cartilage that shows mechanical strength and three-dimensional shape. This type of tissue-engineered cartilage uses scaffold composed of atelocollagen hydrogel and poly-l-lactic acid porous material, which is administered with cultured autologous auricular chondrocytes. Its clinical application to nasal deformity of cleft lip and palate patients has been ongoing at present. This review presents an overview of the current situation regarding cartilage regenerative medicine, as well as introducing our research and the development of implant-type tissue-engineered cartilage for the cleft-lip nose. The discussion of the future development of regenerative medicine is also mentioned.     

CD14 expression and Kupffer cell dysfunction in non-alcoholic steatohepatitis: superparamagnetic iron oxide-magnetic resonance image and pathologic correlation

Background and Aim: Kupffer cell (KC) function and CD14 expression contributes to pathogenesis of non‐alcoholic steatohepatitis (NASH). However, these relationships remain unclear. We investigated the relationship of KC function with superparamagnetic iron oxide‐enhanced magnetic resonance imaging (SPIO‐MRI), histopathological severity of NASH, and number of CD14‐positive KCs in NASH. Methods: This retrospective study included 32 patients (24 with NASH and eight with simple steatosis) who had previously undergone SPIO‐MRI with T2‐weighted gradient‐recalled echo sequence. All subjects were diagnosed pathologically and were evaluated for necroinflammation grade, fibrosis stage, and number of CD14‐positive KCs. Patients with NASH and simple steatosis were compared by using the Mann–Whitney test to determine differences in percent reduction of liver‐to‐muscle signal intensity ratio (reduction‐%LMR), as a surrogate parameter of KC function, and number of CD14‐positive KCs. Kruskal–Wallis test and Pearson's correlation coefficient were used to analyze relation among reduction‐%LMR, histopathological severity and number of CD14‐positive KCs. Results: There were statistically significant differences in reduction‐%LMR and number of CD14‐positive KCs between NASH and simple steatosis patients (Mann–Whitney test, P < 0.001 for all comparisons). Reduction‐%LMR decreased with an increase in necroinflammation grade or fibrosis stage. The number of CD14‐positive KCs increased with an increase in necroinflammation grade and fibrosis stage (Kruskal–Wallis test, both, P < 0.001). A high correlation was seen between number of CD14‐positive KCs and reduction‐%LMR (Pearson r = 0.81; P < 0.001). Conclusions: KC phagocytic function evaluated with SPIO‐MRI correlated with histopathological severity and number of CD14‐positive KCs. These results support the concept that KC phagocytic dysfunction contributes to the pathogenesis of NASH.     

Comparison of magnetoencephalography,functional MRI,and motor evoked potentials in the localization of the sensory-motor cortex

Abstract

To clarify the topographical relationship between peri-Rolandic lesions and the central sulcus, we carried out presurgical functional mapping by using magnetoencephalography (MEG), functional magnetic resonance imaging (f-MRI), and motor evoked potentials (MEPs) on 5 patients. The sensory cortex was identified by somatosensory evoked magnetic fields using MEG (magnetic source imaging (MSI)). The motor area of the hand region was identified using f-MRI, during a hand squeezing task. In addition, transcranial magnetic stimulation localized the hand motor area on the scalp, which was mapped onto the MRI. In all cases, the sensory cortical vein or the lack of any functional activation in the area of peri-lesional edema. MEPs were also unable to localize the entire motor strip. Therefore, at present, MSI is considered to be the most reliable method to localize peri-Rolandic lesions. [Neurol Res 1995; 17: 361-367] cortical vein or the lack of any functional activation in the area of peri-lesional edema. MEPs were also unable to localize the entire motor strip. Therefore, at present, MSI is considered to be the most reliable method to localize peri-Rolandic lesions. [Neurol Res 1995; 17: 361-367]