Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Shoko M. Yamada is active.

Publication


Featured researches published by Shoko M. Yamada.


Surgical Oncology-oxford | 2011

A case of multiple brain metastases of uterine leiomyosarcoma with a literature review

So Yamada; Shoko M. Yamada; Hiroshi Nakaguchi; Mineko Murakami; Katsumi Hoya; Akira Matsuno

Brain metastasis from uterine leiomyosarcoma is extremely rare, and prognostically alarming despite various treatments. The authors report a case of multiple brain metastases from uterine leiomyosarcoma who took a favorable course after tumor resection and γ-knife treatment. A 50-year-old woman with a history of hysterectomy for uterine leiomyosarcoma two years earlier, presented with a recent onset of headaches and vomiting. Multiple cerebral lesions were found by magnetic resonance imaging (MRI). The Karnofsky performance scale (KPS) was 40 with left hemiparesis and cerebellar ataxia. She was treated by resection of the left occipital and cerebellar tumors, followed by γ-knife irradiation of the residual tumors. KPS was 70 at her discharge from the hospital. MRI failed to show recurrence of the intracranial lesions 6 months after irradiation. She remained at home until she died from massive intra-abdominal bleeding. This is the first case with multiple brain metastases from uterine leiomyosarcoma, who survived with remarkable neurological improvement for 12 months. No comparable survival has been reported in the literature. It is evident that surgical resection and additional γ-knife irradiation contributed to early neurological recovery.


Clinical Neurology and Neurosurgery | 2012

A simple and consistent technique for ventricular catheter insertion using a tripod.

Shoko M. Yamada; So Yamada; Yoshiaki Goto; Hiroshi Nakaguchi; Mineko Murakami; Katsumi Hoya; Akira Matsuno

OBJECTIVE For long-term preservation of ventriculo-peritoneal (VP) shunt function, it is essential to place the ventricular catheter tip above the foramen of Monro. But the free-hand technique for ventricular catheter passage is not consistent. METHODS Supposing that a convex of skull matches to a sphere, in which the foramen of Monro is the center, a perpendicular direction from the surface of the sphere to inside always directs toward the center. The authors identified the range of skull where corresponded to the sphere by magnetic resonance imaging assessment and utilized tripod to achieve exactly perpendicular insertion of ventricular catheter. And an optimal length of catheter insertion was investigated by navigation system. RESULTS The anterior-posterior range of the spherical portion was from coronal suture to 20mm anterior, and the lateral range of it was between 15 and 35mm lateral from sagittal suture. The optimal catheter length for insertion was between 55 and 58mm from the brain surface. Ideal placement of a ventricular catheter tip was achieved in more than 90% of cases (31/34) with this technique. CONCLUSION Tripod-guided ventricular catheter insertion is a simple and reliable method for VP shunt at any angle of head-rotation.


Neurosurgery | 2009

Bypass coaptation for cervical root avulsion: indications for optimal outcome.

Shokei Yamada; Russell R. Lonser; Austin R. T. Colohan; Shoko M. Yamada; Daniel J. Won

OBJECTIVEPreviously, we reported bypass coaptation of the C3 and C4 anterior rami to the upper trunk of the brachial plexus for restoration of the muscles denervated as a result of C5 and C6 nerve root avulsion. This procedure is thought to be superior to the transfer of individual peripheral nerve fibers to the brachial plexus branches. Therefore, the benefits of the bypass coaptation procedures in the treatment of various root avulsions are presented. METHODSTwenty-six patients were selected as suitable candidates for bypass coaptation procedures. They were divided into 3 groups: 1) Erb-Duchenne palsy due to C5 and C6 root avulsion, 2) Klumpke palsy due to C8 and T1 root avulsion, and 3) the flail arm (or flail upper limb) due to C5 through T1 root avulsion. The surgical techniques are described in detail. RESULTSThe coaptation procedures for the first group resulted in excellent recovery of all the denervated muscles. The patients in the second group showed reinnervation of the finger muscles and finger sensory distributions in infants within the first year after surgery. The flail arm group regained satisfactory proximal muscle function but only mild distal muscle function. One exception was a child who showed significant recovery in proximal and distal motor and sensory function. CONCLUSIONWe recommend the bypass coaptation as a useful procedure for the following categories: Erb-Duchenne palsy due to C5 and C6 root avulsion in all ages, Klumpke palsy due to the C8 and T1 avulsion, and the flail arm due to C5 through T1 avulsion in young children. However, bypass procedures for the flail limb in adults require additional innovative methods to facilitate the growth rate of regenerating nerves.


Journal of Medical Case Reports | 2012

Tumefactive multiple sclerosis requiring emergent biopsy and histological investigation to confirm the diagnosis: a case report

So Yamada; Shoko M. Yamada; Hiroshi Nakaguchi; Mineko Murakami; Katsumi Hoya; Akira Matsuno; Kazuto Yamazaki; Yasuo Ishida

IntroductionTumefactive multiple sclerosis is a demyelinating disease that demonstrates tumor-like features on magnetic resonance imaging. Although diagnostic challenges without biopsy have been tried by employing radiological studies and cerebrospinal fluid examinations, histological investigation is still necessary for certain diagnosis in some complicated cases.Case presentationA 37-year-old Asian man complaining of mild left leg motor weakness visited our clinic. Magnetic resonance imaging demonstrated high-signal lesions in bilateral occipital forceps majors, the left caudate head, and the left semicentral ovale on fluid-attenuated inversion recovery and T2-weighted imaging, and these lesions were enhanced by gadolinium-dimeglumin. Tumefactive multiple sclerosis was suspected because the enhancement indistinctly extended along the corpus callosum on magnetic resonance imaging and scintigraphy showed a low malignancy of the lesions. But oligoclonal bands were not detected in cerebrospinal fluid. In a few days, his symptoms fulminantly deteriorated with mental confusion and left hemiparesis, and steroid pulse therapy was performed. In spite of the treatment, follow-up magnetic resonance imaging showed enlargement of the lesions. Therefore, emergent biopsy was performed and finally led to the diagnosis of demyelinating disease. The enhanced lesion on magnetic resonance imaging disappeared after one month of prednisolone treatment, but mild disorientation and left hemiparesis remained as sequelae.ConclusionsFulminant aggravation of the disease can cause irreversible neurological deficits. Thus, an early decision to perform a biopsy is necessary for exact diagnosis and appropriate treatment if radiological studies and cerebrospinal fluid examinations cannot rule out the possibility of brain tumors.


Medical Molecular Morphology | 2014

Molecular status of pituitary carcinoma and atypical adenoma that contributes the effectiveness of temozolomide

Akira Matsuno; Mineko Murakami; Katsumi Hoya; Shoko M. Yamada; Shinya Miyamoto; So Yamada; Jae-Hyun Son; Hajime Nishido; Fuyuaki Ide; Hiroshi Nagashima; Mutsumi Sugaya; Toshio Hirohata; Akiko Mizutani; Yudo Ishii; Shigeyuki Tahara; Akira Teramoto; R. Yoshiyuki Osamura

There have been several reports of temozolomide (TMZ) treatment of pituitary carcinomas and atypical adenomas. O6-methyl-guanine-DNA methyltransferase is not the sole molecule determining the sensitivity to TMZ in pituitary carcinomas and atypical adenomas. The Japan Society of Hypothalamic and Pituitary Tumors study suggests that MSH6, one of mismatch repair pathway enzyme, fulfills a contributory role to the efficacy of TMZ treatment for pituitary carcinomas and atypical adenomas. The preserved MSH6 function might be essential for the responsiveness to TMZ treatment in pituitary carcinomas and atypical adenomas.


Clinical Journal of Sport Medicine | 2014

Vertebral artery dissection caused by swinging a golf club: case report and literature review.

Shoko M. Yamada; Yoshiaki Goto; Mineko Murakami; Katsumi Hoya; Akira Matsuno

Vertebral artery (VA) dissection caused by swinging a golf club is extremely rare, and the mechanism of the dissection has not been elucidated. A 39-year-old man suddenly felt sharp neck pain and dizziness when he swung a driver while playing golf and visited our clinic. Imaging studies showed acute right cerebellar infarction and complete occlusion of the right VA at the C2 (axis) level. After 1 month of 100 mg aspirin treatment, the occluded right VA was completely recanalized and the patient became totally asymptomatic. Professional golfers look at the position of the ball on the ground or tee until completion of their follow-through. However, some amateur golfers look in the direction that the ball travels at the beginning of their follow-through. It is hypothesized that this rapid disproportionate head rotation produces VA elongation and distortion, mainly at the C2 level, causing stenosis or occlusion of the artery.


Brain Tumor Pathology | 2010

A cystic meningioma misdiagnosed as malignant glioma by radiologic and intraoperative histological examinations

Shoko M. Yamada; Yasunori Fujimoto; Yu Kawanishi; Keiji Shimizu

Cystic meningiomas are radiologically difficult to differentiate from malignant brain tumors, particularly when the tumors are intraparenchymally located. In such cases, a surgical strategy relies on intraoperative histological diagnosis. A 60-year-old man had a tumor with multiple cysts in the left parietal lobe that was diagnosed radiologically as malignant glioma. In operative findings, there was no dural attachment of the tumor, and the border between the tumor and normal brain tissue was unclear. Intraoperative histological examination supported the diagnosis of malignant glioma based on a high cellularity and an existence of a multinuclear giant cell in the tumor tissue. We finished the surgery with partial tumor resection; however, postoperative histological diagnosis of the tumor was a typical meningothelial meningioma showing characteristic whorl formations, and in conclusion, a definite diagnosis of the tumor was an intraparenchymal cystic meningioma. In further histological investigations, the tumor tissue around cysts exhibited significantly different features from meningothelial meningioma, demonstrating small lymphocytes and histiocytes with a large nucleus, which resembled intraoperative histological findings. We deliberated that the removal of the tumor tissue from the degenerated portion for intraoperative histological examination might lead to the misdiagnosis of malignant glioma. Operative strategy is strongly influenced by intraoperative histological diagnosis. Therefore, surgeons are obliged to facilitate more precise intraoperative histological examinations by obtaining sufficient tissue from different parts of the tumor.


Acta Histochemica Et Cytochemica | 2013

Clinicopathological and molecular histochemical review of skull base metastasis from differentiated thyroid carcinoma.

Akira Matsuno; Mineko Murakami; Katsumi Hoya; Shoko M. Yamada; Shinya Miyamoto; So Yamada; Jae-Hyun Son; Hajime Nishido; Fuyuaki Ide; Hiroshi Nagashima; Mutsumi Sugaya; Toshio Hirohata; Akiko Mizutani; Yudo Ishii; Shigeyuki Tahara; Akira Teramoto; R. Yoshiyuki Osamura; Kazuto Yamazaki; Yasuo Ishida

Skull base metastasis from differentiated thyroid carcinoma including follicular thyroid carcinoma (FTC) and papillary thyroid carcinoma (PTC) is a rare clinical entity. Eighteen FTC cases and 10 PTC cases showing skull base metastasis have been reported. The most common symptom of skull base metastasis from FTC and PTC is cranial nerve dysfunction. Bone destruction and local invasion to the surrounding soft tissues are common on radiological imaging. Skull base metastases can be the initial clinical presentation of FTC and PTC in the presence of silent primary sites. The possibility of skull base metastasis from FTC and PTC should be considered in patients with the clinical symptoms of cranial nerve dysfunction and radiological findings of bone destruction. A variety of genetic alterations in thyroid tumors have been identified to have a fundamental role in their tumorigenesis. Molecular histochemical studies are useful for elucidating the histopathological features of thyroid carcinoma. Recent molecular findings may provide novel molecular-based treatment strategies for thyroid carcinoma.


Radiation Oncology | 2012

Advanced therapeutic strategy for radiation-induced osteosarcoma in the skull base: a case report and review

Shoko M. Yamada; Yudo Ishii; So Yamada; Shigehiko Kuribayashi; Shin-ichiro Kumita; Akira Matsuno

A review of patients with skull base osteosarcoma secondary to radiation (radiation-induced osteosarcoma: RIOS) of the pituitary tumor shows the mean survival of approximately 7 months (2 weeks – 16 months). This warning prognosis seems to stem from two factors, 1) the anatomical complexity of the skull base for total resection of the tumor, and 2) standard adjuvant therapies for the tumor yet to be established. Contrary to the general belief, the authors report an unusually long survival of a 75-year-old woman with a history of osteosarcoma that developed in the same sequence 20 years after pituitary tumor radiation. On her recent admission, she complained of frontal headaches and MRI studies showed a tumor in the sphenoid sinus. Endoscopic trans-nasal tumor removal allowed for histological diagnosis of an osteosarcoma. However, further rapid tumor growth necessitated a radical tumor resection followed by a combined chemotherapy with ifosfamide, cisplatin, and etoposide (ICE). Despite temporary suppression of the tumor growth, the chemotherapy was discontinued due to severe pancytopenia that occurred after three courses of treatment. Shortly after the discontinuation of ICE therapy, the tumor size increased again rapidly, requiring a novel radiation therapy, Cyber-knife treatment. Following this radiation, the tumor growth was arrested, and the patient remains healthy without neurological symptoms over 24 months. The outcome of Cyber-knife in this case suggests that this specific therapy must be considered for the unresectable skull base RIOS.


Molecules | 2011

Molecular Morphology of Pituitary Cells, from Conventional Immunohistochemistry to Fluorescein Imaging

Akira Matsuno; Akiko Mizutani; Koji Takano; So Yamada; Shoko M. Yamada; Hiroshi Nakaguchi; Katsumi Hoya; Mineko Murakami; Masato Takeuchi; Mutsumi Sugaya; Johbu Itoh; Susumu Takekoshi; Robert Yoshiyuki Osamura

In situ hybridization (ISH) at the electron microscopic (EM) level is essential for elucidating the intracellular distribution and role of mRNA in protein synthesis. EM-ISH is considered to be an important tool for clarifying the intracellular localization of mRNA and the exact site of pituitary hormone synthesis on the rough endoplasmic reticulum. A combined ISH and immunohistochemistry (IHC) under EM (EM-ISH&IHC) approach has sufficient ultrastructural resolution, and provides two-dimensional images of the subcellular localization of pituitary hormone and its mRNA in a pituitary cell. The advantages of semiconductor nanocrystals (quantum dots, Qdots) and confocal laser scanning microscopy (CLSM) enable us to obtain three-dimensional images of the subcellular localization of pituitary hormone and its mRNA. Both EM-ISH&IHC and ISH & IHC using Qdots and CLSM are useful for understanding the relationships between protein and mRNA simultaneously in two or three dimensions. CLSM observation of rab3B and SNARE proteins such as SNAP-25 and syntaxin has revealed that both rab3B and SNARE system proteins play important roles and work together as the exocytotic machinery in anterior pituitary cells. Another important issue is the intracellular transport and secretion of pituitary hormone. We have developed an experimental pituitary cell line, GH3 cell, which has growth hormone (GH) linked to enhanced yellow fluorescein protein (EYFP). This stable GH3 cell secretes GH linked to EYFP upon stimulation by Ca2+ influx or Ca2+ release from storage. This GH3 cell line is useful for the real-time visualization of the intracellular transport and secretion of GH. These three methods from conventional immunohistochemistry and fluorescein imaging allow us to consecutively visualize the process of transcription, translation, transport and secretion of anterior pituitary hormone.

Collaboration


Dive into the Shoko M. Yamada's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Akiko Mizutani

Teikyo Heisei University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge