Shunsuke Sakakibara

Ectopic corticospinal tract and corticothalamic tract neurons in the cerebral cortex of yotari and reeler mice.

Reeler and yotari mice, which are mutant for Reelin or Dab1, respectively, show disorders of cerebral cortical lamination. We injected horseradish peroxidase (HRP) into the upper lumbar enlargement to label corticospinal tract (CST) neurons and wheat germ agglutinin‐conjugated HRP (WGA‐HRP) into the ventral lateral nucleus of the thalamus to label corticothalamic tract (CTT) neurons in both 19‐day‐old yotari and reeler mice with the aim of discovering whether or not they show differences in the distribution pattern of layer V or layer VI neurons. Similar injections of tracers were made in normal controls. HRP‐labeled CST neurons, which were exclusively distributed in layer V of the normal cortex, were radially scattered in the cortex of both mutants, but those in reeler were more deeply distributed than in yotari. WGA‐labeled CTT neurons, which were mainly located in layer VI in the normal cortex, were superficially distributed just beneath the pia mater in both reeler and yotari cortex. The present quantitative study shows that the distribution pattern of layer V neurons, but not layer VI neurons, differs between reeler and yotari mice, suggesting that the Reelin and Dab1 proteins may play different roles in the migration and cell positioning of layer V neurons. J. Comp. Neurol. 461:61–75, 2003.

The superficial layers of the superior colliculus are cytoarchitectually and myeloarchitectually disorganized in the reelin-deficient mouse, reeler

The causative gene for the reeler mouse is reelin which encodes Reelin protein, an extracellular molecule. In the present study, we have examined the cytoarchitecture, myeloarchitecture, and afferent/efferent systems of the superior colliculus (SC) of the reeler mouse. In the reeler, the laminar structures of the superficial three layers of the SC were disorganized and intermingled into a single layer, i.e., the superficial fused layer (SuF), as previously reported in the reelin-deficient SRK rat (Sakakibara et al., Develop. Brain Res. 141:1-13). Next, we have investigated the course and terminals of visual corticotectal and retinotectal projections with an injection of biocytin into the visual cortex or an injection of cholera toxin subunit B into the retina, respectively. In the reeler, anterogradely labeled visual corticotectal and retinotectal fibers took an aberrant course within the SuF, resulting in abnormal myeloarchitecture of the superficial SC of the reeler. Retrograde labeling of tectospinal tract neurons could not show any differences between the normal and reeler mice, suggesting that the deep layers of the reeler SC are cytoarchitectually normal. In situ hybridization and immunohistochemical studies have shown that reelin mRNA and Reelin protein were both recognized in the normal SC. These results suggest that Reelin protein plays some roles in histogenesis of the superficial layers of the SC.

Cytoarchitecture and fiber pattern of the superior colliculus are disrupted in the Shaking Rat Kawasaki

Shaking Rat Kawasaki (SRK) is a Reelin-deficient rat, that shows significant cytoarchitectural abnormalities in the cerebral and cerebellar cortices in a similar manner to the reeler malformation. In the present study, we investigated the cytoarchitecture and myeloarchitecture of the superior colliculus (SC) of this mutant rat. The Nissl staining clearly showed that neuronal components in the superficial layers of the SC in SRK rat were intermingled with each other and that the boundaries between these superficial layers were blurred. The MBP immunohistochemistry showed an abnormal fiber pattern in the superficial layers of the SC of this mutant rat. In the normal rat, myelinated fibers passed rostrocaudally through the optic layer, and only a few myelinated fibers were recognized in the uppermost two layers, i.e., the zonal and superficial gray layers. By contrast, in SRK rat, the myelinated fibers were distributed throughout the entire thickness of the superficial layers of the SC. Anterograde labeling of retinotectal fibers with an injection of Cholera Toxin subunit B into the retina revealed that this abnormal fiber pattern was associated with the anomalous course of the retinotectal fibers. No distinct differences in the cytoarchitecture and fiber pattern in the deep layers of the SC were seen. In conclusion, the present study demonstrated that the cytoarchitecture and fiber patterning in the superficial layers of the SC were disrupted in SRK rat, suggesting that Reelin protein regulates the formation of the superficial layers of the SC.

Preoperative MR angiography for free fibula osteocutaneous flap transfer

Introduction: Magnetic resonance angiography (MRA) is currently considered the most useful test to evaluate the vascular anatomy of the lower leg prior to free fibula osteocutaneous flap transfer. This study aimed to confirm the validity of preoperative MRA. Methods: In 19 patients underwent free fibula osteocutaneous flap transfer for maxillary and mandibular reconstruction, the MRA and intraoperative findings and the postoperative complications were retrospectively analyzed. The location and number of distal septocutaneous perforators (dSCPs) that were preoperatively identified and harvested with flaps were documented. Results: Preoperative MRA detected dSCPs with 100 % sensitivity. MRA findings also revealed the diversity of vascular structures, such as the tibio‐peroneal bifurcation location and the anatomical relationship between the peroneal vessels and the fibula. No patients suffered postoperative ischemic complications in the donor leg. The total flap survival rate was 95 %. Conclusions: Preoperative MRA effectively excluded large vessel anomalies and peripheral vascular disease, and precisely identified the septocutaneous perforators. Additionally, preoperative MRA contributed to a safer fibular osteotomy by predicting the anatomical relationship between the peroneal vessels and the fibula.

Concomitant chemoradiotherapy for advanced squamous cell carcinoma of the temporal bone.

The purpose of this study was to analyze outcomes for the treatment of locally advanced temporal bone cancer by means of concomitant chemoradiotherapy (CCRT) with a combination of cisplatin (CDDP), 5‐fluorouracil (5‐FU), and docetaxel (TPF).

Comparison of reinnervation for preservation of denervated muscle volume with motor and sensory nerve: an experimental study.

Prevention of the atrophy of denervated muscles is essential for a good outcome in facial contouring and oral reconstruction. In this study, we compared the effectiveness of end-to-end and end-to-side neurorrhaphy of the motor nerve, and end-to-end neurorrhaphy of the sensory nerve, all of which are frequently used in such reconstruction for the prevention of muscle atrophy. Wistar rats were divided into four groups: group 1, motor nerve division of semi-membranosus without repair; group 2, motor nerve division and end-to-end coaptation to the saphenous nerve; group 3, motor nerve division and end-to-side coaptation to the sciatic nerve; and group 4, motor nerve division and end-to-end repair. Measurement of semi-membranosus volume, histological evaluation and staining of neuromuscular junctions that were carried out 3 months postoperatively revealed that muscle volume preservation was larger in groups 3 and 4 than in the other two groups (p<0.05), but slightly superior in group 4 (p<0.05). There was no statistical difference between groups 2 and 1; histologically, muscle architecture was better preserved in group 2 than in group 1; reactivation of the neuromuscular junctions was observed in all except group 1. End-to-side repair of motor nerves is one of the better options for the preservation of muscle volume when end-to-end nerve repair is not indicated. Sensory protection may also provide some advantages in the preservation of muscle volume.

Risk Factors and Surgical Refinements of Postresective Mandibular Reconstruction: A Retrospective Study

Background. Postresective mandibular reconstruction is common in cases of oral and mandibular tumors. However, complications such as infection, plate exposure, or plate fracture can occur. We identified several significant risk factors of complications after reconstructive surgery and compared the effectiveness of different surgical techniques for reducing the incidence of complications. Methods. This study is a retrospective analysis of 28 oromandibular cancer cases that required reconstructive surgery between January 1999 and December 2011 at Kobe University Graduate School of Medicine in Japan. All cases were classified using Hashikawas CAT and Eichners classification methods. Then, we determined whether these classifications and different treatment or surgical methods were significantly related to complications. Results. Complications after mandibular reconstruction occurred in 10/28 patients (36%). Specifically, five patients had plate fractures, four had plate exposures, and one had an infection. Radiation therapy and closure without any flaps were significantly related to infection or plate exposure. The wrap-around technique of securing reconstruction plates was used in 14 cases, whereas the run-through technique was used in two cases. Conclusions. The success of mandibular reconstruction depends on both mechanical and biological factors, such as the location of defects, presence of occlusions, and the amount of vascularization of the flap.

One-Stage Umbilicus Reconstruction After Resection of Urachal Cyst

AbstractUmbilical reconstruction after total excision of the umbilicus represents a challenging problem for reconstructive surgeons. We describe herein a new method for one-stage umbilical reconstruction after resection of a urachal cyst. This case series included 6 patients, with laparoscopic urachal cyst removal in 5 and conventional transcutaneous surgery in 1. One-stage umbilical reconstruction was performed in all cases. When a conventional transcutaneous approach is indicated, umbilical reconstruction can be undertaken through the same skin incision used for total resection of the urachal cyst. Two triangular flaps were designed just below the umbilical defect. Flaps were rotated 180 degrees and sutured together to form one big triangular flap. This flap was then folded to create the new umbilicus. A deep umbilicus with good shape was constructed in all cases, and all patients were satisfied with the outcome. This method is simple, easy, and produces a natural-looking umbilicus.

Three-dimensional venous visualization with phase-lag computed tomography angiography for reconstructive microsurgery.

BACKGROUND Most free flap reconstruction complications involve vascular compromise. Evaluation of vascular anatomy provides considerable information that can potentially minimize these complications. Previous reports have shown that contrast-enhanced computed tomography is effective for understanding three-dimensional arterial anatomy. However, most vascular complications result from venous thromboses, making imaging of venous anatomy highly desirable. METHODS The phase-lag computed tomography angiography (pl-CTA) technique involves 64-channel (virtually, 128-channel) multidetector CT and is used to acquire arterial images using conventional CTA. Venous images are three-dimensionally reconstructed using a subtraction technique involving combined venous phase and arterial phase images, using a computer workstation. RESULTS This technique was used to examine 48 patients (12 lower leg reconstructions, 34 head and neck reconstructions, and 2 upper extremity reconstructions) without complications. The pl-CTA technique can be used for three-dimensional visualization of peripheral veins measuring approximately 1 mm in diameter. CONCLUSION The pl-CTA information was especially helpful for secondary free flap reconstructions in the head and neck region after malignant tumor recurrence. In such cases, radical dissection of the neck was performed as part of the first operation, and many vessels, including veins, were resected and used in the first free-tissue transfer. The pl-CTA images also allowed visualization of varicose changes in the lower leg region and helped us avoid selecting those vessels for anastomosis. Thus, the pl-CTA-derived venous anatomy information was useful for exact evaluations during the planning of free-tissue transfers.

Effect of local application of transcutaneous carbon dioxide on survival of random-pattern skin flaps

INTRODUCTION Skin flap procedures are widely used to reconstruct skin and soft tissue defects. Skin flap necrosis is a serious postoperative complication. Many researchers have introduced pharmacological agents to improve flap ischemia in experimental studies. However, outcomes of these studies remain controversial. We previously demonstrated that transcutaneous CO2 application improves hypoxia in fracture repair. In this study, we hypothesized that improving hypoxia by transcutaneous CO2 application can improve the blood flow in skin flaps and increase angiogenesis. We investigated whether transcutaneous CO2 application can increase the survival of random-pattern skin flaps. MATERIALS AND METHODS Six-week-old male Sprague-Dawley rats were divided into two equal groups: the control group (n = 6) and CO2 group (n = 6). A random-pattern skin flap was constructed in these rats. Topical CO2 was applied using a hydrogel every day for 5 days in the CO2 group. The flap survival area was measured on postoperative days 1, 3, and 5. The vessel density and expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and hypoxia-inducible factor-1α (HIF-1α) were evaluated on postoperative day 5. RESULTS A statistically significant difference was found in the percentage of the flap survival area between the two groups on postoperative days 3 and 5 (p < 0.05). Furthermore, the expression of VEGF and bFGF was significantly higher and that of HIF-1α was significantly lower in the CO2 than in the control group (p < 0.05). CONCLUSIONS Transcutaneous CO2 application can improve the blood flow in skin flaps and increase angiogenesis, thus increasing the survival of random-pattern skin flaps.