Choice of osseous and osteocutaneous flaps for mandibular reconstruction

Microvascular free flap transfer currently represents one of the most popular methods for mandibularreconstruction. With the various free flap options nowavailable, there is a general consensus that no single kindof osseous or osteocutaneous flap can resolve the entire spectrum of mandibular defects. A suitable flap, therefore, should be selected according to the specific type of bone and soft tissue defect. We have developed an algorithm for mandibular reconstruction, in which the bony defect is termed as either “lateral” or “anterior” and the soft-tissue defect is classified as “none,” “skin or mucosal,” or “through-and-through.” For proper flap selection, the bony defect condition should be considered first, followed by the soft-tissue defect condition. When the bony defect is “lateral” and the soft tissue is not defective, the ilium is the best choice. When the bony defect is “lateral” and a small “skin or mucosal” soft-tissue defect is present, the fibula represents the optimal choice. When the bony defect is “lateral” and an extensive “skin or mucosal” or “through-and-through” soft-tissue defect exists, the scapula should be selected. When the bony defect is “anterior,” the fibula should always be selected. However, when an “anterior” bone defect also displays an “extensive” or “through-and-through” soft-tissue defect, the fibula should be usedwith other soft-tissue flaps. Flaps such as a forearm flap, anterior thigh flap, or rectus abdominis musculocutaneous flap are suitable, depending on the size of the soft-tissue defect.     

Angiotensin blockade inhibits osteopontin expression in non-infarcted myocardium after myocardial infarction

Osteopontin has been reported to have an important role in cardiac fibrosis. However, little is known about the effects of angiotensin-converting enzyme inhibitor (ACEI) and angiotensin type 1 receptor blockers (ARB) on osteopontin expression in infarcted myocardium. The purpose of this study was to elucidate the effects of an ACEI (perindpril) and an ARB (candesartan cilexitil) on cardiac function as assessed by Doppler echocardiography and cardiac osteopontin expression associated with cardiac remodeling in myocardial infarcted rats. ACEI or ARB was administered after myocardial infarction (MI). At 4 weeks after MI, cardiac function, and mRNAs in non-infarcted myocardium were analyzed. ACEI and ARB equally prevented left ventricular dilatation, reduction of ejection fraction, and the increase in E/A wave velocity ratio and the rate of E wave deceleration by MI. ACEI and ARB significantly suppressed increased mRNA expression of atrial natriuretic peptide, brain natriuretic peptide, osteopontin, and collagen I and III in the non-infarcted ventricle at 4 weeks. Immunohistochemically stained osteopontin was increased in interstitial fibrosis of non-infarcted myocardium. Both ACEI and ARB significantly prevented cardiac fibrosis and osteopontin expression. In conclusion, angiotensin blockade inhibits osteopontin expression in non-infarcted myocardium and prevents cardiac remodeling after MI.     

Preparing oral dosage form of ketamine in the hospital for simplicity and patient compliance--preparations using agar

Ketamine has been widely used in the operation as intravenous and intramuscular injections, since ketamine has dissociative anesthetic properties. When it is given in sub-anesthetic dose, ketamine is known to have an analgesic effect. The analgesic effect is observed for patients with neuropathic pain when administrated not only by injection but also orally. In Japan, since ketamine is not commercially available except injection forms, patients have to take it as solution of injections for the oral medication. Since the solution of injections has extremely bitter taste, patients intensely desire the development of preparations without the bitterness. In the present study, we prepared oral gel dosage forms of ketamine using agar. It is simple to prepare this dosage form, and most pharmacists can prepare it easily in many hospitals. This gel dosage form met content uniformity requirements and the shape of that was maintained intact during the dissolution test (for 10 hours). The release rate was reduced by additions of additives such as sugar and a flavor in the gel. The reason for the reduction in release could be the suppression of ketamine diffusion depended on the micro-viscosity of solution in the gel. The ketamine contents and the release profile of the gel preparations were unchanged at the room temperature for 12-week storage. The gel preparations in this study would be useful for the oral medication of ketamine, since it is easy for patients to carry them when they go out and the intensely bitter taste could be improved by the addition of a flavor.     

Secondary reconstruction of failed esophageal reconstruction

Between June 1992 and November 2002, 17 patients underwent secondary reconstruction of circumferential esophageal defects due to the failure of immediate reconstruction following ablation of thoracic esophageal cancer. Salvage reconstruction was achieved using free jejunal transfer in 13 patients (including long segment with double vascular pedicle in 2 cases), skin and/or musculocutaneous flap in 2 cases, and jejunal pull-up in 2 cases. In 5 patients, the second salvage surgery was required because of the failed first salvage. However, successful restoration of the esophagus and peroral alimentation was finally achieved in 16 of 17 patients, except 1 patient with several salvage operations using skin and musculocutaneous flap because the gut was unusable. We concluded that the preferred first choice for salvage restoration is free jejunal transfer. If the length of the esophageal defect is extensive, colonic interposition or jejunal pedicle with microvascular anastomosis for supercharging is the next option. If these procedures cannot be used, the transfer of a long jejunal segment with double vascular pedicles is recommended. Reconstruction using skin and/or musculocutaneous flap is the final option. As primary wound closure is often difficult in secondary reconstruction of the esophagus, a pectoralis major musculocutaneous flap is reliable to cover the reconstructed esophagus because skin flaps located in the neck region may be damaged by neck dissection or irradiation, and coverage of the anastomosis with muscle between the digestive tracts is effective to prevent leakage.     

Cobalt chloride induces neurite outgrowth in rat pheochromocytoma PC-12 cells through regulation of endothelin-2/vasoactive intestinal contractor

We investigated whether endothelin-2/vasoactive intestinal contractor (ET-2/VIC) gene expression, upregulated by hypoxia in cancer cells, was associated with differentiation in neuronal cells. RT-PCR analysis, morphological observations, and immunostaining revealed that CoCl2, a hypoxic mimetic agent, at 200 microM increased expression of the ET-2/VIC gene, decreased expression of the ET-1 gene, and induced neurite outgrowth in PC-12 rat pheochromocytoma cells. These effects induced by 200 microM CoCl2 were completely inhibited by the antioxidant N-acetyl cysteine at 20 mM. In addition, CoCl2 increased the level of intracellular reactive oxygen species (ROS) at an early stage. Furthermore, interleukin (IL)-6 gene expression was upregulated upon the differentiation induced by CoCl2. These results suggest that expression of ET-2/VIC and ET-1 mediated by ROS may be associated with neuronal differentiation through the regulation of IL-6. When the cells were treated with 500 microM CoCl2 for 24 hr, however, ET-2/VIC gene expression disappeared, IL-6 gene expression was downregulated, and necrosis was subsequently induced in the PC-12 cells.     

T staging of gastric cancer: role of multi-detector row CT

PURPOSE: To evaluate retrospectively the accuracy of multi-detector row computed tomography (CT) in the assessment of serosal invasion in patients with gastric cancer. MATERIALS AND METHODS: The Ethics Committee does not require approval or informed consent for retrospective studies. Forty-one consecutive patients (24 men, 17 women; mean age, 68 years) with gastric cancer were included in this study. All patients were given 600 mL of tap water to drink and were positioned prone or supine on the scanning table. The detector row configuration included four detector rows, a section thickness of 1.25 mm, a pitch of 6, and a reconstruction interval of 0.63 mm. Transverse and multiplanar reconstruction images were simultaneously evaluated by two independent observers to assess the depth of tumor invasion in the gastric wall (ie, T stage). T staging at multi-detector row CT was compared with T staging at histologic evaluation (reference standard), which was performed by means of surgical or histologic examination of the resected specimen. We also calculated the sensitivity, specificity, and accuracy of multi-detector row CT for each observer in the assessment of serosal invasion. RESULTS: Analysis of interobserver agreement showed substantial or almost perfect agreement (nonweighted kappa value of 0.78 and weighted kappa value of 0.85). Correct assessment of gastric wall invasion was 80% and 85% for observers 1 and 2, respectively. The sensitivity, specificity, and accuracy of multi-detector row CT in the assessment of serosal invasion were 90%, 95%, and 93%, respectively, for observer 1 and 80%, 97%, and 93%, respectively, for observer 2. Overstaging occurred in six patients, and understaging occurred in five patients. All understaged tumors were scirrhous subtype gastric cancer. CONCLUSION: Multi-detector row CT scanning of patients with gastric cancer gave 93% accuracy in the assessment of serosal invasion in patients with gastric cancer.     

Prospective respiratory-triggered multidetector row CT (MDCT) for abdominal examinations: initial experience with a prototype

PURPOSE: To develop a prototype for prospective respiratory-triggered multidetector row computed tomography (MDCT) for abdominal examinations and to assess its feasibility. MATERIALS AND METHODS: The prototype consisted of the following components: an MDCT unit, personal computer (PC), and a respiratory motion detector in the form of a wearable belt with sensors to measure differences in pressure caused by breathing excursions. The registered signals were processed by the PC. The abdominal MDCT images of 10 healthy volunteers were obtained with an incremental axial technique in the expiration phase during normal breathing. Multiplanar reformations (MPR) were then performed. On the basis of the precision of these reconstructions, two radiologists then assessed the accuracy and applicability of the system. RESULTS: Coronal and sagittal MPR images from these prospective respiratory-gated examinations were found to be accurate. In particular, the continuity of borders and surfaces of scanned organs proved the exactness of the previously acquired respiration-correlated axial source images. CONCLUSION: This prototype is feasible to perform prospective respiratory-triggered abdominal MDCT examinations during normal respiration without breathhold. This system may be useful for patients with reduced compliance in holding their breath.     

Contrast-enhanced volumetric interpolated breath-hold examination compared with spin-echo T1-weighted imaging of head and neck tumors

OBJECTIVE: Volumetric interpolated breath-hold examination (VIBE) is a relatively new gradient-echo MR sequence that is capable of shortening acquisition times and is reported to be useful in abdominal and brain imaging. The purpose of this study was to evaluate the feasibility of using VIBE images as a substitute for conventional postcontrast spin-echo T1-weighted images in the assessment of head and neck tumors. SUBJECTS AND METHODS: The subjects were 33 consecutive patients referred for MRI for preoperative assessment of head and neck tumors. After administration of gadodiamide hydrate, images were obtained using postcontrast fat-saturated VIBE sequence for a 35-sec acquisition time and then a postcontrast fat-saturated spin-echo T1-weighted sequence for a 269-sec acquisition time ( approximately 4.5 min). Quantitative comparisons of the two methods were made by calculating signal-to-noise and contrast-to-noise ratios for both methods, and qualitative comparisons were made on the basis of the scoring of three independent reviewers concerning image quality and tumor conspicuity. RESULTS: No significant difference was detected quantitatively between the two sequences. However, in qualitative assessments, the degree of image degradation by artifacts was significantly smaller for VIBE images than for spin-echo T1-weighted images (p = 0.029). CONCLUSION: In preoperative evaluations of head and neck tumors, the postcontrast VIBE sequence is capable of decreasing acquisition time without degrading image quality or tumor conspicuity; thus, it is an acceptable alternative to postcontrast spin-echo T1-weighted imaging.