Koji Goto

Role of a positive regulator of root hair development, CAPRICE ,in Arabidopsis root epidermal cell differentiation

In Arabidopsis, root hairs are formed only from a set of epidermal cells named trichoblasts or hair-forming cells. Previous studies showed CAPRICE (CPC) promotes differentiation of hair-forming cells by controlling a negative regulator, GLABRA2 (GL2), which is preferentially expressed in hairless cells. Here, we show that CPC is also predominantly expressed in the hairless cells, but not in the neighboring hair-forming cells, and that CPC protein moves to the hair-forming cells and represses the GL2 expression. We also show that the N terminus of bHLH protein interacts with CPC and is responsible for the GL2 expression. We propose a model in which CPC plays a key role in the fate-determination of hair-forming cells.

Functional divergence of the TFL1‐like gene family in Arabidopsis revealed by characterization of a novel homologue

The TERMINAL FLOWER 1 (TFL1) gene of Arabidopsis plays an important role in regulating flowering time and in maintaining the fate of inflorescence meristem (IM). TFL1 is a homologue of CENTRORADIALIS (CEN) from Antirrhinum, which is only involved in IM maintenance. Recent mutational studies and the genome project revealed that TFL1 belongs to a small gene family in Arabidopsis, in which functional divergence may have occurred among the members.

Operative treatment of hip impingement caused by hypertrophy of the anterior inferior iliac spine

A 30-year-old man presented with pain and limitation of movement of the right hip. The symptoms had failed to respond to conservative treatment. Radiographs and CT scans revealed evidence of impingement between the femoral head-neck junction and an abnormally large anterior inferior iliac spine. Resection of the hypertrophic anterior inferior iliac spine was performed which produced full painless restoration of function of the hip. Hypertrophy of the anterior inferior iliac spine as a cause of femoro-acetabular impingement has not previously been described.

A new cementless total hip arthroplasty with bioactive titanium porous-coating by alkaline and heat treatment: Average 4.8-year results

A method has been developed for creating a bioactive coating on titanium by alkaline and heat treatment, and shown that it forms a thin layer of hydroxyapatite (HA) on the surface of implants when soaked in simulated body fluid. A series of 70 cementless primary total hip arthroplasties using this coating technique on a porous titanium surface was performed, and followed up the patients for a mean period of 4.8 years. There were no instances of loosening or revision, or formation of a reactive line on the porous coating. Although radiography just after operation showed a gap between the host bone and the socket in over 70% of cases, all the gaps disappeared within a year, indicating the good osteoconduction provided by the coating. Alkaline-heat treatment of titanium to provide a thin HA coating has several advantages over plasma-spraying, including no degeneration or absorption of the HA coating, simplicity of the manufacturing process, and cost effectiveness. In addition, this method allows homogeneous deposition of bone-like apatite within a porous implant. Although this was a relatively short-term study, treatment that creates a bioactive surface on titanium and titanium alloy implants has considerable promise for clinical application.

Identification of nuclear factor δEF1 and its binding site essential for lens-specific activity of the δ1-crystallin enhancer

The lens-specific reglatory element of the delta 1-crystallin enhancer lies within the core segment (Goto et al., (1990) Mol. Cell. Biol. 10, 935-964). The element was allocated within the 55 bp long HN fragment of the core. Block-wise base substitutions were introduced to the 55 bp and their effect on the enhancer activity of the multimers in lens cells was examined. By base sequence alteration of either of the contiguous blocks 5 and 6, with their original sequence of TTGCT and CACCT, respectively, enhancer activity was totally lost. A lens nuclear factor delta EF1 was found which bound specifically to the base sequences defined by the blocks. DNA binding activity very similar to delta EF1 was also found in extracts of tissues other than lens, suggesting that delta EF1 participates in lens-specific regulation through tissue-dependent modification or interaction with other factors.

Prevalence and Characterization of Pulmonary Vein Variants in Patients With Atrial Fibrillation Determined Using 3-Dimensional Computed Tomography

Although several branching patterns of pulmonary veins (PVs) were reported, their prevalence and characterization were not sufficiently clarified. Multislice computed tomography was performed in 428 patients who underwent catheter ablation for drug-refractory atrial fibrillation. Size and branching pattern of PVs were analyzed. A typical pattern of 4 PVs with 4 separate ostia was found in 326 patients (76%). However, a common PV trunk, defined as a PV with coalescence of superior and inferior PVs > or =1.5 cm proximal to the junction with the left atrium, was found on the left side in 34 patients (8%) and right side in 3 patients (0.76%). A discrete middle PV was found on the right side in 54 patients (13%) and left side in 9 patients (2%). A right top PV, defined as an anomalous insertion of a branch of the right superior PV into the left atrial body, was also found in 16 patients (4%). In conclusion, 24% of our patients with atrial fibrillation had PV anomalies and 3% had coexistence of 2 PV variants, indicating that PV variants are not rare.

EFFECTS OF GHRELIN TREATMENT ON PATIENTS UNDERGOING TOTAL HIP REPLACEMENT FOR OSTEOARTHRITIS: DIFFERENT OUTCOMES FROM STUDIES IN PATIENTS WITH CARDIAC AND PULMONARY CACHEXIA

non-dominant hemisphere anterior lesions. In posterior watershed infarctions, hemi-anopsia is common. Watershed infarctions in the bilateral frontal lobes can cause severe dementia. PV is a chronic, myeloproliferatieve disorder, predominantly presenting in elderly patients with an incidence rate of 23.5 per 100,000 person-years. Symptoms are due to hyperviscocity. A feared complication of PV is thrombosis (venous or arterial). Together with transformation into myelofibrosis, acute leukemia, or both, thrombosis is the main cause of death. The median survival of treated patients exceeds 10 year. This case history illustrates that an unusual course of cognitive impairment necessitates in-depth clinical investigation.

Clinical and radiological evaluation of revision hip arthroplasty using the cement-in-cement technique

We reviewed 44 consecutive revision hip replacements in 38 patients performed using the cement-in-cement technique. All were performed for acetabular loosening in the presence of a well-fixed femoral component. The mean follow-up was 5.1 years (2 to 10.1). Radiological analysis at final follow-up indicated no loosening of the femoral component, except for one case with a continuous radiolucent line in all zones and peri-prosthetic fracture which required further revision. Peri-operative complications included nine proximal femoral fractures (20.4%) and perforation of the proximal femur in one hip. In five hips wiring or fixation with a braided suture was undertaken but no additional augmentation was required. There was an improvement in the mean Japanese Orthopaedic Association score from 55.5 (28 to 81) pre-operatively to 77.8 (40 to 95) at final follow-up (p < 0.001). Revision using a cement-in-cement technique allows increased exposure for acetabular revision and is effective in the medium term. Further follow-up is required to assess the long-term results in the light of in vitro studies which have questioned the quality of the cement-in-cement bond.

Load dispersion effects of acetabular reinforcement devices used in revision total hip arthroplasty: a simulation study using finite element analysis.

Several types of acetabular reinforcement devices are used to prevent the collapse of grafted bone in revision total hip arthroplasty. However, it remains unclear how the stress is reduced by different devices. We used finite element analysis to evaluate 4 types of acetabular reinforcement devices: Kerboull-type device, Burch-Schneider anti-protrusio cage, Mueller ring, and Ganz ring. The control was a socket fixed with bone cement without any reinforcement devices. The stress distribution on the inner surface of each socket was calculated by binarization image processing. For all 4 reinforcement devices, the stress was reduced to less than one-half of that in the control. All the devices were useful for preventing the collapse of bulk bone grafts applied to load-bearing defects.

Clinical Results of the Wear Performance of Cross-Linked Polyethylene in Total Hip Arthroplasty: Prospective Randomized Trial

To investigate the clinical results of cross-linked polyethylene (CLPE) and to compare the CLPE wear against zirconia and stainless steel heads, we studied the radiographic wear after a minimum 3-year follow-up in total hip arthroplasty (THA). Ninety-four hips were randomly implanted with a 22.225-mm head cemented THA-the group of non-CLPE against zirconia and CLPE against 2 different zirconias and stainless steel. The linear wear rate was significantly lower in the group of CLPE against zirconia (0.067, 0.059 mm/y) and against stainless steel (0.068 mm/y) compared with non-CLPE against zirconia (0.170 mm/y). In the short-term results, the wear performance of CLPE against zirconia was superior to that of non-CLPE; however, it did not show a better wear rate than CLPE against stainless steel. Furthermore, long-term investigations will be necessary for understanding CLPE wear in vivo.