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Biomedical subjects

S Hirabayashi

Publications and source records attributed to S Hirabayashi.

At least 19 recordsLinked to original sources
PubMed2006

Ligand-of-Numb protein X is an endocytic scaffold for junctional adhesion molecule 4.

Junctional adhesion molecule 4 (JAM4) is a cell adhesion molecule that interacts with a tight junction protein, membrane-associated guanylate kinase inverted 1 (MAGI-1). Our previous studies suggest that JAM4 is implicated in the regulation of paracellular permeability and the signalings of hepatocyte growth factor. In this study, we performed yeast two-hybrid screening to search for an unidentified JAM4-binding protein and obtained one isoform of Ligand-of-Numb protein X1 (LNX1), LNXp70, that is an interactor of Numb. Ligand-of-Numb protein X1 is expressed in kidney glomeruli and intestinal epithelial cells, where JAM4 is also detected. Immunoprecipitation from kidney lysates supports the in vivo interaction of proteins. Biochemical studies reveal that JAM4 directly binds the second PDZ domain of LNX1 through its carboxyl terminus. Junctional adhesion molecule 4, LNX1 and Numb form a tripartite complex in vitro and are partially colocalized in heterologous cells. Ligand-of-Numb protein X1 facilitates endocytosis of JAM4 and is involved in transforming growth factor beta -induced redistribution of JAM4 in mammary epithelial cells. Experiments using dominant-negative constructs and RNA interference insure that Numb is necessary for the LNX1-mediated endocytosis of JAM4. All these findings indicate that LNX1 provides an endocytic scaffold for JAM4 that is implicated in the reorganization of cell junctions.

Animals↗
PubMed2001

Staged spinal cord decompression through posterior approach for thoracic myelopathy caused by ossification of posterior longitudinal ligament.

STUDY DESIGN: Prospective clinical study of the effect of staged elimination of anatomic factors inhibiting posterior shift of the thoracic spinal cord on the degree of posterior shift of the thoracic spinal cord and its significance in augmenting the safety of ossification of posterior longitudinal ligament (OPLL) manipulation in thoracic OPLL myelopathy. OBJECTIVES: To develop a comprehensive method that enables safe and sufficient decompression of the spinal cord for thoracic OPLL myelopathy. SUMMARY OF BACKGROUND DATA: Decompression of the spinal cord by direct manipulations of thoracic OPLLs, via either anterior or posterior approach, caused some iatrogenic catastrophic spinal cord injuries, and methods to prevent such injuries during surgery have not yet been developed. METHODS: Procedures of elimination of anatomic factors inhibiting posterior shift of the thoracic spinal cord were performed in stages at intervals of between 1 month and 11 years depending on patients' neurologic status. The first stage operation consisted of extensive cervicothoracic laminoplastic decompression with or without posterior longitudinal durotomy, and if the decompression were insufficient, measures for OPLL-spinal cord separation with or without OPLL manipulation were added. RESULTS: All 17 patients with thoracic OPLL myelopathy showed improvements of neurology comparable with those with successful anterior approaches after decompression. The mean follow-up period was 42 months (range 6-101 months). Neurologic improvements persisted for the entire follow-up period in all patients except one patient who developed arachnoid cyst compressing the dorsum of the once-decompressed spinal cord 30 months after surgery. CONCLUSIONS: Staged posterior decompression to eliminate anatomic factors inhibiting posterior shift of the thoracic spinal cord is the safest and the most reliable method of spinal cord decompression to treat thoracic OPLL myelopathy, so far. However, long-term results are required before the methods can be established.

Adult↗
PubMed2001

Skeletal analysis of craniofacial deformities in brachycephaly: comparison with craniofacial deformities in plagiocephaly.

The deformities of craniofacial bones in brachycephaly (n = 2) and plagiocephaly (n = 2) were compared using three-dimensional skull replicas. In brachycephaly the bilateral deformities of the cranial base were similar to the unilateral deformities on the affected side in plagiocephaly. Shortening of the anterior-middle cranial fossas and expansion of the middle cranial fossas suggest downward and anterior displacement of both temporomandibular (TM) joints resulting in the underdevelopment of the middle-inferior facial bones, though this is less conspicuous in brachycephaly for three reasons. The most important one is that the patients have an imposing facial morphology characterised by high, protruding facial bones, as found on the affected side in plagiocephaly. Secondly, the frontal bones are flattened and positioned posteriorly in the anteroposterior direction, which also helps to mask the underdevelopment of the middle-inferior facial bones. Finally, as bony deformities are symmetrical in brachycephaly, they are not as obvious as they would be if they were unilateral.

Child↗
PubMed2001

Unusual development of acute compartment syndrome caused by a suction injury: a case report.

There have been recent reports of acute compartment syndrome secondary to suction injuries of the hands of children. We report the case of a 68-year-old patient who developed an acute compartment syndrome of the forearm after his arm had been sucked into an exhaust port. He was treated by emergency fasciotomies and the wound was closed five days later with a small skin graft. His recovery was uneventful.

Acute Disease↗
PubMed2001

Optimized 3-D CT scan protocol for longitudinal morphological estimation in craniofacial surgery.

Frequent three-dimensional computed tomography scanning may cause deterioration of the lenses of the eye, which are susceptible to x-rays. The authors performed an experimental study using a phantom head to establish an optimized three-dimensional computed tomography scan protocol for longitudinal morphological estimation in craniofacial surgery. Volume computed tomography scans were performed using a Hi-Speed Advantage SG CT scanner (GE Medical Systems, Milwaukee, WI) in the axial plane with a combination of scan parameters of varied values. The radiation doses induced by each scanning were measured using thermoluminescent dosimeter chips attached to the position of the lenses in the phantom. Two-dimensional images in the coronal plane and three-dimensional images of the osseous surface were generated from each accumulated data set. For each scan parameter, the images generated from data accumulated using different values were compared. The study showed that lens radiation dose increased with tube potential and was almost directly proportional to tube current and 1/pitch. The slice thickness did not affect lens radiation doses significantly. Images with good contrast resolution and low artifact level sufficient for estimating morphological changes were obtained using a low tube potential of 100 kVp and a tube current of 100 mA. In regard to z-axis spatial resolution, a slice thickness of less than 3 mm was required for precisely pointing out bony edges in the two-dimensional reformation images. These results led us to conclude that volume computed tomography for longitudinal examination in craniofacial surgery should be kept to a minimum frequency and performed using a low-dose technique, small slice thickness, and large pitch.

Artifacts↗
PubMed2001

[Laparoscopic radical prostatectomy--initial 10 cases].

PURPOSE: We report the clinical results and efficacy of laparoscopic radical prostatectomy for localized prostate cancer. PATIENTS AND METHODS: Between December, 1999 and June, 2000 we performed transperitoneal laparoscopic radial prostatectomy on 10 patients with T1 or T2 organ confined prostate cancer according to the techniques as described by Guillonneau et al. Different points were as follows: 1) We placed double J catheters during surgery to prevent ureteral injury. 2) We treated dorsal vein complex using an Endo-GIA-stapler. 3) We dissected the bladder neck from the prostate using an ultrasound scalpel in the manner to preserve the bladder neck. RESULT: We could not completed laparoscopic prostatectomy on two patients because of massive bleeding from dorsal vein and consuming too much time to suture urethra-bladder anastomosis. The average operating time in all cases was 8.1 hours including 1.8 hours in laparoscopic pelvic lymphadenectomy. The average estimated blood loss in all cases was 859 ml. There were 2 surgical complications with bladder injury and port site hernia. The histological examination revealed prostate cancer; pT2pNO in 8, pT3pNO in 2. The surgical margin and lymph nodes were negative in all patients. The duration of an indwelling catheter ranged from 5 to 40 days mean 17 days. The duration to recovery of normal micturition was 6 to 90 days, mean 40 days. CONCLUSION: Long-term follow-up and extensive studies are necessary to evaluate the efficacy of this procedure. It might provide shorter duration of an indwelling catheter and earlier recovery of normal micturition as compared with the conventional open surgery.

Aged↗
PubMed2000

Localization of BAI-associated protein1/membrane-associated guanylate kinase-1 at adherens junctions in normal rat kidney cells: polarized targeting mediated by the carboxyl-terminal PDZ domains.

Brain-specific angiogenesis inhibitor (BAI)-associated protein (BAP)1 (also called membrane-associated guanylate kinase [MAGI]-1) is composed of six PSD-95/Dlg-A/ZO-1 (PDZ) domains, two WW domains, and one guanylate kinase (GK) domain. We previously reported that BAP1 is localized at tight junctions in Madine Darby canine kidney (MDCK) cells and intestinal epithelial cells. Here, we have determined the localization of BAP1 in normal rat kidney (NRK) cells that do not form tight junctions. BAP1 was colocalized with E-cadherin along the lateral membrane, suggesting its localization at adherens junctions. Green fluorescent protein (GFP)-BAP1 was distributed in the cytosol in separate NRK cells, and accumulated to the cell-cell contacts when NRK cells have contact with each other. The GFP-BAP1 mutant containing either the first PDZ and GK domains or the WW and second PDZ domains was localized in the cytosol and the nucleus. The GFP-BAP1 mutant containing the second to fourth PDZ domains was distributed in the cytosol. The construct containing the fifth and sixth PDZ domains was localized at the cell-cell contacts along the lateral membrane and slightly in the nucleus, whereas the construct lacking the fifth and sixth PDZ domains was localized in the cytosol and in the nucleus. BAP1 was tyrosine-phosphorylated in vivo, but the tyrosine phosphorylation of BAP1 was not correlated with its localization. These results suggest that the signal in the carboxyl-terminal PDZ domains functions dominantly in vivo to target BAP1 to the lateral membrane, although potential nuclear localization signals exist in the N-terminal region of BAP1.

Adherens Junctions↗
PubMed2000

The value of a new method for assessing the separate functions of the long tracts and involved segments in patients with cervical myelopathy.

In order to assess accurately lesions of the spinal cord in patients with cervical myelopathy we have developed a new method of examination, which is based on the Japanese Orthopaedic Association (JOA) scoring system. The method attempts to assess separately the functions of the long tract and any involved cord segments in respect to the period after treatment. It was used in 117 consecutive patients who were divided into 2 groups based on whether or not there was a T2-high-intensity lesion within the spinal cord, as revealed by a preoperative magnetic resonance imaging scan (MRI). The results of this method correlated well with the MRI findings. It was assumed that the degree of function of the upper limbs in patients with a T2-high-intensity lesion revealed more about a segment than about the long tract.

Adult↗
PubMed2000

A neurodegenerative disorder with early myoclonic encephalopathy, retinal pigmentary degeneration and nephronophthisis.

A female case of developmental arrest, early-onset seizures, retinal pigmentary degeneration, progressive central nervous symptoms and peripheral neuropathy, associated with progressive renal dysfunction, anemia and nephrotic syndrome, was presented. Her epileptic syndrome was possibly an early myoclonic encephalopathy, though neonatal seizures were not evident. Serial cranial MRIs showed progressive brain atrophy and a white matter change. Neuropathological examination revealed a neurodegenerative disease mainly involving the white matter with olivopontocerebellar degeneration. She also had the nephronophthisis-medullary cystic disease complex and an early stage of focal segmental glomerulosclerosis. Her grandaunts had renal diseases, one of whom died of renal failure in adolescence, and her father showed cerebellar symptoms since the middle age. All possible metabolic studies were negative. This case is similar to Senior-Loken syndrome, but distinct in terms of the severe and progressive neurological symptoms, suggestive of a new malignant syndrome with some inherent metabolic derangement affecting both the nervous system and the kidneys.

Age Factors↗
PubMed2000

Application of the distraction technique to scaphocephaly.

The case of a 1-year-old boy who underwent correction of a scaphocephalic deformity using distraction devices is described. Double pi-shaped osteotomies were cut. Bilateral temporal bone flaps were gradually expanded, and the frontal bone was pulled back simultaneously. The patient showed a good skull contour 2 years postoperatively. Although previous distractions were aimed only at expansion of the cranium, we used the distraction technique to successfully shorten the cranial vault in the anteroposterior direction. This case demonstrates that the osteotomized bone flaps can be moved in various directions. This feature of the distraction technique may contribute greatly toward meticulous reconstruction of the cranial vault.

Craniosynostoses↗
PubMed1999

New method for measuring area of spinal canal after double-door laminoplasty.

In the double-door laminoplasty procedure used for patients with cervical myelopathy, techniques to obtain a wider spinal canal have been tested. We hypothesized that making the lateral gutters as lateral as possible may be effective for obtaining a wider spinal canal. In this study we aimed to test our hypothesis by using a new measurement method to assess the postoperative cross-sectional area of the spinal canal. Fifty-six vertebrae were operated on in 11 patients, using the STSS spacer (Asahi Optical, Tokyo, Japan). On computed tomography (CT) scans, the most posterior edge of a space-occupying lesion was defined as point A and a horizontal line through point A was drawn parallel to the posterior wall of the vertebral body (line X). Two oblique lines were drawn along the medial margin of the bilateral split laminae (lines R and L). The triangular area enclosed by lines X, R, and L was defined as the substantial area of the spinal canal (SASC). A horizontal line through the median points of the bilateral facet joint in the anteroposterior direction was defined as line B. According to the relative position of line X to line B, two types of vertebra were observed: In type 1, line X was located ventral to line B; in type 2, line X was located dorsal to line B. The mean data values for type 1 vertebra were: SASC, 133.1 mm2; ATD, 22.9 mm; angle R, 61.3 degrees; and angle L, 61.8 degrees. The mean data values for type 2 vertebra were: SASC, 99.8 mm2; ATD, 20.1 mm; angle R, 58.6 degrees; and angle L, 57.5 degrees. There were significant differences between types 1 and 2 vertebrae in values both for SASC and ATD (P < 0.01). There were no significant differences between types 1 and 2 vertebrae regarding angles R and L. The difference in SASC in the two types appeared to arise from the difference in ATD. In other words, the degree of enlargement of the spinal canal was determined not by the inclination of the bilateral split laminae, but by the transverse diameter. This result supports the validity of our hypothesis. In a double-door laminoplasty, to obtain a wider spinal canal, the lateral gutters must be made as lateral as possible (i.e., at the medial border of the facet joints, especially in type 2 vertebra). On the preoperative CT scan, the relative positions of the large-volume lesion and the facet joint must be noted.

Anatomy, Cross-Sectional↗
PubMed1999

New method of assessing outcome of treatment for cervical myelopathy (M/T method)--preliminary report.

In some patients with cervical radiculomyelopathy, neurological examination reveals extreme muscle weakness in an upper extremity with no, or a relatively insignificant, sensory deficit. In assessment of treatment outcome in these patients, the previous method used is thought to be unsuitable. We developed a new method of assessment (the M/T method) in which the recovery of upper extremity muscle weakness is assessed. The purpose of this study was to evaluate this new method. In the M/T method, change in the function of the spinal cord, including the anterior root, is expressed as an index number (recovery rate) in relation to the time-course. The function of the nerve tissue is expressed as the value for the manual muscle testing (MMT) of muscle power, and the muscle tested is represented by one that has the least MMT value before treatment. The unit of measurement of the time-course is 3 months. The index is the difference between the MMT value at the time of follow-up and that before treatment, divided by the number of time units after treatment. The index can be expressed in both fractional and decimal forms. Fractions are useful for examining an individual patient's progress and the decimal form is useful for comparing the data of multiple patients. The M/T method was employed in 16 patients (13 men, 3 women; age, 45-79 years; follow-up, 6 months - 8 years) whose chief complaints were muscle weakness in the upper extremities and who had undergone double-door laminoplasty. Seven patients had an M/T index of 1 or more; the score was 4 in one patient, 2 in four patients, and 1 in two patients. Two patients had an M/T index between 0 and 1; 0.17 and 0.25. Five patients had an index value of 0. The M/T index in two patients was less than 0; -0. 17 and -0.11. Using the M/T method, recovery can be presented as an index number, and as a result, it is easy to compare differences in the recovery rate among patients. The M/T method is useful for evaluation of the viability of the spinal cord, including the anterior root; in particular for those patients in whom neurological examination reveals extreme muscle weakness in an upper extremity with no, or a relatively insignificant, sensory deficit.

Aged↗
PubMed1999

Contact of hydroxyapatite spacers with split spinous processes in double-door laminoplasty for cervical myelopathy.

We developed a new type of spacer made of hydroxyapatite (the STSS spacer) for double-door laminoplasty, and evaluated the contact of 93 STSS spacers with the split spinous processes in 20 patients with double-door laminoplasty. Contact was assessed by measuring the extent of touch of the spacer to the spinous processes, classified into four categories based on computed tomography (CT) images: excellent, complete touch on both sides of the spacer to the spinous process; good, complete touch on one side and more than half touch on the other side; fair, more than half touch on both sides; poor, half or less touch on at least one side. Excellent contact was achieved in 65 spacers (69.9%); good, in 13 (14.0%); fair, in 11 (11. 8%); and poor, in 4 (4.3%). The percentages of excellent or good categories were 75.0% at the C3 level, 73.7% at the C4 level, 78.9% at the C5 level, 90.0% at the C6 level, and 100% at the C7 level. The contact rate of the STSS spacer with the spinous process was better than that achieved with other spacers, probably because the characteristic shape of the STSS spacer was compatible with the widened space between the bilateral spinous processes; i.e., it is trapezoidal on both the axial and the frontal sections. However, the appropriate size of the spacer must be selected in accordance with the size of the spinous process to obtain higher percentages of excellent or good contact.

Adult↗
PubMed1999

Effects of antigen dose and immunization regimens on antibody responses to a cytomegalovirus glycoprotein B subunit vaccine.

The purpose of this phase I study was to evaluate the safety and immunogenicity of 2 doses of cytomegalovirus glycoprotein B (CMV gB)/MF59 vaccine at 3 different immunization schedules. Ninety-five volunteers were randomized to 6 groups. Antibodies to gB represent the majority of the CMV-specific neutralizing response. Three groups received 5 microgram of gB antigen combined with MF59 (a proprietary adjuvant) and 3 groups received a 30-microgram dose at 0, 1, and 2 months; 0, 1, and 4 months; or 0, 1, and 6 months. The vaccine was well tolerated, and there was no significant difference in antibody production between the 2 doses. The vaccine induced highest antibody titers when given at 0, 1, and 6 months. A low dose of CMV gB/MF59 may be the preferred dose for future studies.

Adjuvants, Immunologic↗