Chromosome-Scale Genome Assembly and Characterization of Top-Quality Japanese Green Tea Cultivar 'Seimei'.

Japanese green tea, an essential beverage in Japanese culture, is characterized by the initial steaming of freshly harvested leaves during production. This process efficiently inactivates endogenous enzymes such as polyphenol oxidases, resulting in the production of sencha, gyokuro and matcha that preserves the vibrant green color of young leaves. Although genome sequences of several tea cultivars and germplasms have been published, no reference genome sequences are available for Japanese green tea cultivars. Here, we constructed a reference genome sequence of the cultivar 'Seimei', which is used to produce high-quality Japanese green tea. Using the PacBio HiFi and Hi-C technologies for chromosome-scale genome assembly, we obtained 15 chromosome sequences with a total genome size of 3.1 Gb and an N50 of 214.9 Mb. By analyzing the genomic diversity of 23 Japanese tea cultivars and lines, including the leading green tea cultivars 'Yabukita' and 'Saemidori', it was revealed that several candidate genes could be related to the characteristics of Japanese green tea. The reference genome of 'Seimei' and information on genomic diversity of Japanese green tea cultivars should provide crucial information for effective breeding of such cultivars in the future.

[Usefullness of intrasacral fixation in an extremely unstable lumbosacral spine].

Intrasacral fixation technique devised by Jackson is said to provide rigid lumbosacral fixation. We treated 3 cases of lumbosacral lesions using this technique in which lumbosacral segment had become extremely unstable during surgical intervention adding to the effect of original lesions. In all cases, surgeries were performed in 2 stages, intrasacral fixation and anterior stabilization. Case 1: A 52-year-old male was diagnosed fungal discitis and spondylitis at L4 and L5. X-ray showed destruction of the vertebral bodies. L2, L3 and sacrum were fixed posteriorly using the intrasacral fixation technique. One week after the first operation, L4 and L5 vertebral bodies were replaced by long fibula grafts through the extraperitoneal approach. Case 2: A 25-year-old female with cauda equina syndrome and abnormal body form diagnosed as having spondyloptosis in which the entire vertebral body of L5 had descended below the endplate of S1. MR imaging revealed marked canal stenosis at the S1 level. In the first surgery, L5 vertebral body was resected through the transperitoneal approach. After 1 week of bed rest, posterior segments of L5 were resected, L4 was affixed to the sacrum and anterior stabilization was achieved with 2 mesh cages and lumbosacral spine was fixed using the intrasacral fixation technique. Case 3: A 64-year-old female was diagnosed as having pyogenic discitis and osteomyelitis at the L5-S1 level. In spite of successful medical treatment for infection, low back pain continued. Radiologically, L5 vertebral body was shown to have collapsed and slipped anteriorly over the sacrum. L3, L4 and sacrum were fixed by intrasacral fixation. One week after the first operation, the L5/S1 disc and the suppurtive vertebral bodies were resected through the extraperitoneal approach and anterior stabilization was performed with iliac bone grafts. At follow-up for a minimum of 6 months, initial fixation was maintained in all 3 cases and bony fusion was obtained. The intrasacral fixation technique was considered to be effective for extremely unstable lumbosacral lesions.

Combined use of TruFill DCS detachable coil system and Guglielmi detachable coil for embolization of meningioma fed by branches of the cavernous internal carotid artery.

A 57-year-old female presented with a left petroclival meningioma fed by the meningohypophyseal trunk of the internal carotid artery (ICA). The enlarged tentorial marginal artery and inferior hypophyseal artery were successfully embolized with the TruFill DCS Detachable Coil System through a 0.019-inch inner diameter microcatheter. Superselective catheterization into the dorsal meningeal artery could not be achieved with the same microcatheter, because the catheter tip was too large to pass into the vessel. Subsequently the feeding artery was successfully embolized with a Guglielmi detachable coil (GDC) through a 0.016-inch inner diameter microcatheter. The patient underwent surgery without blood loss on the day after embolization. Our subjective impression was that the TruFill DCS was softer and had less resistance during insertion, whereas the GDC could be delivered through a smaller caliber system for smaller vessels. Appropriate use of the TruFill DCS and GDCs can allow efficient embolization of the feeding branches of the ICA.

[Embolization for aneurismal dilatation associated with ruptured dissecting anterior inferior cerebellar artery aneurysm with preservation of the parent artery: case report].

We report a rare case of a ruptured dissecting anterior inferior cerebellar artery (AICA) aneurysm treated by endosaccular embolization with a Guglielmi detachable coil (GDC). An 85-year-old female presented with headache. Computed tomographic (CT) scan showed subarachnoid hemorrhage and intraventricular hemorrhage in the fourth ventricule. Cerebral angiography and 3D-CT angiography revealed an aneurysmal dilatation at the anterior pontine segment of the right AICA with a diagnosis of arterial dissection. The right posterior inferior cerebellar artery (PICA) was absent and the right AICA supplied the territory normally nourished by the right PICA. The aneurismal dilatation was occluded by endosacullar embolization with preservation of the AICA. The distal AICA aneurysm is rare and only seven cases treated with endovascular embolization have been reported. In these, six cases were treated by parent artery occlusion with coil and the subsequent three cases presented with ischemic complications. Only one case was treated by endosaccular embolization with GDC. To our knowledge, this is the second report of the distal AICA aneurysm treated by endosaccular embolization with GDC. Distal AICA aneurysms are briefly discussed while reviewing the literature.

[A case of cervical endodermal cyst].

A very rare case involving an endodermal cyst of the cervical spinal canal was documented. In 1999, a 28-year-old male presented with mild tetraplegia due to a traffic accident and consequently, he was admitted to another hospital. Magnetic resonance imaging (MRI) performed at that time demonstrated a cervical cord cyst. He was treated conservatively and as a result, complete resolution of symptoms was achieved. Five years later, he presented with progressive right hemiparesis and was referred to our institute. MRI at the time of admission exhibited an intradural extramedullary cystic lesion on the ventral side of the spinal cord at the C5-6 levels, which was characterized by low intensity on T1-weighted, and by high intensity on T2-weighted images. The cyst, which had increased in size, compressed the spinal cord remarkably backward. The anterior central vertebrectomy approach was performed. Subtotal resection of the cyst wall was conducted due to its tight partical adhesion to the spinal cord. The vertebral defect was reconstructed with an autogenous iliac graft. According to histological findings the cyst wall consisted of a single layer of columnar epithelial cells with secretory granules and immunohistochemical examination revealed that the cyst wall was positive for cytokeratin 7. Symptoms improved immediately. Subsequently, the patient was discharged with good performance status. Endodermal cysts are very rare developmental cysts derived from the embryonic endodermal layer. Moreover, these lesions are usually located intradurally in the cervical and upper dorsal spine ventral to the spinal cord. Total removal of the cyst is recommended if it is possible. However, total resection is often difficult due to adhesion of the cyst wall to the neural tissue so invasive resection should be avoided. In such cases, follow-up MRI is necessary in order to exclude recurrence of the remnant lesion.

[Preoperative embolization of metastatic spinal tumors].

The authors reviewed their clinical experience with preoperative embolization of metastatic spinal tumors. Between October 2000 and September 2003, 20 patients (13 men and 7 women; average age 68.3 years, range 44-82 years) underwent 24 spinal operations for 22 spinal metastatic tumors. Nineteen spinal operations (79%) were planned preoperative embolization with polyvinyl alcohol particles. In 3 cases, there was no tumor stain. Fifty percent of the C4-T2 lesions and 76% of the T3-L3 lesions were embolized preoperatively. The level of lesions determined which embolization procedure should be used. With C7-T2 or sacral lesions, feeding arteries were superselectively catheterized, then particles were injected via a microcatheter. With T3-L3 lesions, selective catheterization of the corresponding segmental arteries was performed. Particles were injected via 4 or 5Fr catheters. No complications were encountered during embolization. Embolizing from the origin of the segmental arteries is effective for reducing intraoperative blood loss because feeding vessels in the anterior part of the spinal body are able to be embolized. Preoperative embolization is not a very complicated procedure and careful catheterization can avoid complications. Based on tumor histology, size of the spinal body, depth of the operative field and operative approach, preoperative embolization can be performed with positive results.

Stereotactically inserted tube-guided brain biopsy using positron emission tomography and magnetic resonance coregistered images--case report.

A 53-year-old man presented with malignant lymphoma manifesting as disturbances of walking and standing. Magnetic resonance (MR) imaging showed multifocal bifrontal lesions which were enhanced by gadolinium-diethylenetriaminepenta-acetic acid. Positron emission tomography (PET) with [18F]fluorodeoxyglucose showed high uptake of tracer in the lesion. The PET-MR coregistered image was used to determine the biopsy target. After right frontal craniotomy, a sterilized probe controlled by a neuronavigation system was directly passed into the tumor, and a guide tube was inserted along the same track. After dura opening, a small corticotomy was performed along the guide tube track and the tumor was biopsied. Histological examination revealed malignant lymphoma. The stereotactically inserted tube-guided brain biopsy was less invasive and provided an accurate diagnosis. The PET-MR coregistered image was helpful for determining the most active lesion of the brain tumor.