Expression of Mouse $\alpha-Amylase$ Gene in Methylotrophic Yeast Pichia pastoris

Uehara Hiroyuki,Choi Du Bok,Park Enoch Y.,Okabe Mitsuyasu The Korean Society for Biotechnology and Bioengine 2000 Biotechnology and Bioprocess Engineering Vol.5 No.1

The expression of the mouse $\alpha-amylase$ gene in the methylotrophic yeast, P pastoris was investigated. The mouse $\alpha-amylase$ gene was inserted into the multi-cloning site of a Pichi a expression vector, pPIC9, yielding a new expression vector pME624. The plasmid pME624 was digested with SalI or BglII, and was introduced into P. pastoris strain GSl15 by the PEG1000 method. Fifty-three transformants were obtained by the transplacement of pME624 digested with SaiII or BglII into the HIS4locus $(38\;of\;Mut^+\;clone)$ or into the AOX1 locus $(15\;of\;Mut^s\;clone)$. Southern blot was carried out in 11 transformants, which showed that the mouse $\alpha-amylase$ gene was integrated into the Pichia chromosome. When the second screening was performed in shaker culture, transformant G2 showed the highest $\alpha-amylase$ activity, 290 units/ml after 3-day culture, among 53 transformants. When this expression level of the mouse $\alpha-amylase$ gene is compared with that in recombinant Saccharomyces cerevisiae harboring a plasmid encoding the same mouse $\alpha-amylase$ gene, the specific enzyme activity is eight fold higher than that of the recombinant S. cerevisiae.

Effect of Pressure on Spontaneous Polarization in Ferroelectric Liquid Crystal Mixtures

Hiroyuki Uehara,Jun Hatano 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.42 No.IV

We have investigated the spontaneous polarization of ferroelectric liquid crystals (FLCs) with dierent phase sequences under pressure. The spontaneous polarization PS of an FLC suddenly decreased and disappeared in the SmC-N transition, where the SmC and N phases coexist. The transition temperature of SmC-N increased and the PS slightly decreased with increasing pressure. On the other hand, the PS of another FLC steadily decreased and disappeared at the SmC-SmA transition temperature TCA, and the magnitude of PS steadily decreased with pressure. The in uence of the pressure on the spontaneous polarization is discussed on the basis of parameters such as the temperature width of the coexistence region T, and P0 and in the equation PS = P0[(TCA .. T)=TCA].

Part one: Research in Korea : Production of Heterologous Protein from Methylotrophic Yeast, Pichia pasteris

( Hiroyuki Uehara ),( Enoch Ys Park ),( Mitsuyasu Okabe ),( Dae Yewn Shin ),( Du Bok Choi ) 한국환경보건학회(구-한국환경위생학회) 2004 Current Challenges and Advances in Environmental H Vol.- No.-

Mid-Term Results of Computer-Assisted Cervical Pedicle Screw Fixation

Masashi Uehara,Jun Takahashi,Keijiro Mukaiyama,Shugo Kuraishi,Masayuki Shimizu,Shota Ikegami,Toshimasa Futatsugi,Nobuhide Ogihara,Hiroyuki Hashidate,Hiroki Hirabayashi,Hiroyuki Kato 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.6

Study Design: A retrospective study. Purpose: The present study aimed to evaluate mid-term results of cervical pedicle screw (CPS) fixation for cervical instability. Overview of Literature: CPS fixation has widely used in the treatment of cervical spinal instability from various causes; however, there are few reports on mid-term surgical results of CPS fixation. Methods: Record of 19 patients who underwent cervical and/or upper thoracic (C2–T1) pedicle screw fixation for cervical instability was reviewed. The mean observation period was 90.2 months. Evaluated items included Japanese Orthopaedic Association (JOA) score and C2–7 lordotic angle before surgery and at 5 years after surgery. Postoperative computerized tomography was used to determine the accuracy of screw placement. Visual analog scale (VAS) for neck pain and radiological evidence of adjacent segment degeneration (ASD) at the 5-year follow-up were also evaluated. Results: Mean JOA score was significantly improved from 9.0 points before surgery to 12.8 at 5 years after surgery (p =0.001). The C2–7 lordotic angle of the neutral position improved from 6.4° to 7.8° at 5 years after surgery, but this was not significant. The major perforation rate was 5.0%. There were no clinically significant complications such as vertebral artery injury, spinal cord injury, or nerve root injury caused by any screw perforation. Mean VAS for neck pain was 49.4 at 5 years after surgery. The rate of ASD was 21.1%. Conclusions: Our mid-term results showed that CPS fixation was useful for treating cervical instability. Severe complications were prevented with the assistance of a computed tomography-based navigation system.

Comparison of Spinous Process-Splitting Laminectomy versus Conventional Laminectomy for Lumbar Spinal Stenosis

Masashi Uehara,Jun Takahashi,Hiroyuki Hashidate,Keijiro Mukaiyama,Shugo Kuraishi,Masayuki Shimizu,Shota Ikegami,Toshimasa Futatsugi,Nobuhide Ogihara,Hiroki Hirabayashi,Hiroyuki Kato 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.6

Study Design: Seventy-five patients who had been treated for lumbar spinal stenosis (LSS) were reviewed retrospectively. Purpose: Invasion into the paravertebral muscle can cause major problems after laminectomy for LSS. To address these problems, we performed spinous process-splitting laminectomy. We present a comparative study of decompression of LSS using 2 approaches. Overview of Literature: There are no other study has investigated the lumbar spinal instability after spinous process-splitting laminectomy. Methods: This study included 75 patients who underwent laminectomy for the treatment of LSS and who were observed through follow-ups for more than 2 years. Fifty-five patients underwent spinous process-splitting laminectomy (splitting group) and 20 patients underwent conventional laminectomy (conventional group). We evaluated the clinical and radiographic results of each surgical procedure. Results: Japanese Orthopaedic Association score improved significantly in both groups two years postoperatively. The following values were all significantly lower, as shown with p -values, in the splitting group compared to the conventional group: average operating time (p =0.002), postoperative C-reactive protein level (p =0.006), the mean postoperative number of days until returning to normal body temperature (p =0.047), and the mean change in angulation 2 years postoperatively (p =0.007). The adjacent segment degeneration occurred in 6 patients (10.9%) in the splitting group and 11 patients (55.0%) in the conventional group. Conclusions: In this study, the spinous process-splitting laminectomy was shown to be less invasive and more stable for patients with LSS, compared to the conventional laminectomy.

Mini Open Foraminotomy for Cervical Radiculopathy: A Comparison of Large Tubular and TrimLine Retractors

Masashi Uehara,Jun Takahashi,Shugo Kuraishi,Masayuki Shimizu,Shota Ikegami,Toshimasa Futatsugi,Kaoru Aoki,Keijiro Mukaiyama,Nobuhide Ogihara,Hiroyuki Hashidate,Hiroki Hirabayashi,Hiroyuki Kato 대한척추외과학회 2015 Asian Spine Journal Vol.9 No.4

Study Design: Retrospective chart review. Purpose: A comparison of mini open foraminotomy (MOF) for cervical radiculopathy using either large tubular (LT) or TrimLine (TL) retractors. Overview of Literature: Posterior foraminotomy relieves compression of the cervical nerve root in radiculopathy patients. However, invasion of the paravertebral muscle may cause major problems in these patients. To address these problems, we performed MOF. Methods: Twenty cervical radiculopathy patients (16 male and 4 female) who underwent MOF between May 2004 and August 2011 were assigned to LT and TL groups. Each group contained 10 subjects. Surgical and clinical outcomes were compared. Results: The average operating time in the TL group was significantly shorter than that in the LT group. The final follow-up mean neck disability indices significantly improved compared to the preoperative values (LT group, 12.0±7.8 vs. 28.0±9.4; TL group, 6.0±5.9 vs. 21.9±10). The final follow-up neck pain visual analog scale (VAS) scores also decreased significantly from the preoperative of 8.0±1.5 and 2.5±2.5 to the final follow-up values of 2.2±2.2 and 1.0±2.5 in the LT and TL groups, respectively. The recovery rate for the neck pain VAS score was 70.0±31.9 in the LT group and 87.0±32.0 in the TL group, thus suggesting no significant difference between the two groups. Conclusions: MOF with the TL retractor is an easy and safe procedure. Furthermore, the use of the TL retractor allows for a minimally invasive and effective surgical treatment of cervical radiculopathy patients.

Myxopapillary Ependymoma of the Cauda Equina in a 5-Year-Old Boy

Masashi Uehara,Jun Takahashi,Keijiro Mukaiyama,Shugo Kuraishi,Masayuki Shimizu,Shota Ikegami,Toshimasa Futatsugi,Kenji Sano,Kazuhiro Hongo,Hiroyuki Kato 대한척추외과학회 2014 Asian Spine Journal Vol.8 No.6

Myxopapillary ependymoma in childhood typically occurs in the central nervous system. There are few surgical cases of myxopapillary ependymoma of the cauda equina in children. We report a case of myxopapillary ependymoma of the cauda equina in a 5-yearold boy, who presented with leg pain and abnormal gait. Subtotal resection surgery was performed. Following the subtotal tumor resection, follow-up magnetic resonance imaging evaluation showed a recurrent tumor. As a result, we performed a second subtotal tumor resection and followed with postoperative radiation therapy. No further evidence of the disease has been noted elsewhere in the patient in over ten years of follow-up. Myxopapillary ependymoma of the cauda equina in a young boy was improved by subtotal tumor resection and postoperative radiation therapy.

Ten-Year Results of Reconstruction for Rheumatoid Cervical Spine Lesions and Occurrence Factor of Subaxial Subluxation

Daisuke Kurogochi,Jun Takahashi,Masashi Uehara,Shota Ikegami,Shugo Kuraishi,Toshimasa Futatsugi,Hiroki Oba,Takashi Takizawa,Ryo Munakata,Terue Hatakenaka,Michihiko Koseki,Hiroyuki Kato 대한척추외과학회 2019 Asian Spine Journal Vol.13 No.5

Study Design: Retrospective chart review. Purpose: This study evaluated long-term surgical outcomes of computer-assisted reconstruction using transarticular or cervical pedicle screws for cervical spine lesions caused by advanced rheumatoid arthritis (RA). Overview of Literature: We routinely employ C1–C2 transarticular and cervical pedicle screw instrumentation to reconstruct advanced and unstable RA cervical lesions. However, few reports are available on the long-term results of surgical reconstruction for rheumatoid cervical disorders, particularly regarding cervical pedicle screw fixation. Methods: Six subjects (all female) with RA cervical lesions who underwent atlantoaxial or occipitocervical fixation and were followed for at least 10 years were retrospectively studied. A frameless, stereotactic, optoelectronic, computed tomography-based image guidance system was used for correct screw placement. Variables including the Japanese Orthopaedic Association score, EuroQol, Ranawat value, and C2–C7 angle before and 2, 5, and 10 years after surgery were assessed along with the occurrence of subaxial subluxation (SAS). Results: Mean age at initial surgery was 58.2±7 years (range, 51–68 years), and mean follow-up period was 141±11 months (range, 122–153 months). Lesions included atlantoaxial subluxation (AAS, n=2) and AAS+vertical subluxation (n=4). Mean C2–C7 lordotic angle before and 2, 5, and 10 years after surgery was 20.1°±6.1°, 21.0°±4.0°, 18.8°±4.7°, and 17.8°±5.3°, respectively. SAS did not occur in cases maintaining the C2–C7 lordotic angle. In two cases where the C2–C7 lordotic angle declined from 5 years postoperatively, SAS occurred at the C2–C3 level in one and at the C4–C5 level in the other, both of which required reoperation. Conclusions: Patients with rheumatoid cervical lesions who undergo atlantoaxial or occipitocervical fixation using C1–C2 transarticular or pedicle screws carry a risk of SAS for up to 10 years postoperatively, which may require reoperation.