Biomedical subjects
Publications and source records attributed to M Ochi.
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In 52 patients we compared the accuracy of standard anteroposterior (AP) radiography, mortise radiography and MRI with arthroscopy of the ankle for the diagnosis of a tear of the tibiofibular syndesmosis. In comparison with arthroscopy, the sensitivity, specificity and accuracy were 44.1%, 100% and 63.5% for standard AP radiography and 58.3%, 100% and 71.2% for mortise radiography. For MRI they were 100%, 93.1% and 96.2% for a tear of the anterior inferior tibiofibular ligament and 100%, 100% and 100% for a tear of the posterior inferior tibiofibular ligament. Standard AP and mortise radiography did not always provide a correct diagnosis. MRI was useful although there were two-false positive cases. We suggest that arthroscopy of the ankle is indispensable for the accurate diagnosis of a tear of the tibiofibular syndesmosis.
BACKGROUND: Satisfactory intermediate and long-term results of periacetabular rotational osteotomy for early osteoarthritis secondary to dysplasia of the hip have been reported for patients in the third and fourth decades of life. The purpose of the present study was to examine the usefulness of rotational acetabular osteotomy in patients older than forty-six years of age. METHODS: A retrospective review of two groups of patients who had been treated with a rotational acetabular osteotomy was conducted. The older group consisted of twenty-four patients (twenty-six hips) with early-stage osteoarthritis who had a mean age at the time of surgery of 50.9 years (range, forty-six to fifty-eight years) and a mean duration of follow-up of 8.2 years (range, five to thirteen years), and the younger group consisted of sixty patients (sixty-three hips) who had a mean age at the time of surgery of 34.4 years (range, thirteen to forty-five years) and a mean duration of follow-up of 8.3 years (range, five to fourteen years). Clinical follow-up was based on the system of Merle d'Aubigne and Postel. The center-edge angle, acetabular roof angle, and head lateralization index were measured on radiographs made preoperatively, postoperatively, and at the time of follow-up. Preoperative and postoperative joint congruencies were classified into four grades. RESULTS: Preoperatively, the mean Merle d'Aubigne clinical score was 13.9 points in the older group and 14.1 points in the younger group. In both groups, this score improved significantly to a mean postoperative follow-up score of 16.6 points (p < 0.0001), with no significant difference between the two groups. The mean center-edge angle improved from 3.2 degrees preoperatively to 34 degrees postoperatively (p < 0.0001) in the older group and from -2.1 degrees preoperatively to 34 degrees postoperatively (p < 0.0001) in the younger group. The mean acetabular roof angle improved from 29 degrees to 5.9 degrees (p < 0.0001) in the older group and from 31 degrees to 2.9 degrees (p < 0.0001) in the younger group. The mean head lateralization index improved from 0.67 to 0.64 (p < 0.01) in the older group and from 0.66 to 0.61 (p < 0.0001) in the younger group. Progression of osteoarthritis was observed radiographically at the time of follow-up in five hips in the older group and in four hips in the younger group. Kaplan-Meier survivorship analysis, with radiographic progression of osteoarthritis as the end point, predicted a ten-year survival rate of 70.0% in the older group and 93.7% in the younger group; this difference was not significant, with the numbers available (p = 0.062, log-rank test). CONCLUSIONS: Our results indicate that rotational acetabular osteotomy for elderly patients can prevent progression of osteoarthritis (as indicated by a survival rate of 70% at ten years) and that in selected cases it is worthwhile at least as a temporizing operation.
A simple, less invasive radial artery harvesting technique involving small skin incisions is described. Only 2 retractors, one of which is light-sourced, are required to construct the operating field. Full harvesting can be accomplished under direct vision with a long-bladed low-voltage electrocautery and forceps through 3 small skin incisions on the forearm. The time required for the harvesting is no longer than that of the standard technique. Spasm of the radial artery has not been seen. Esthetic results are satisfactory.
We investigated the clinical outcome of a reconstructive procedure of the medial patellofemoral ligament for the treatment of habitual or recurrent dislocation of the patella in four children (6 knees), with a minimum follow-up of four years. The technique involves transfer of the tendon of semitendinosus to the patella using the posterior one-third of the femoral insertion of the medial collateral ligament as a pulley. There was no recurrence of dislocation after surgery. The mean Kujala score at follow-up was 96.3 points. Radiological assessment showed that the congruence angle, the tilt angle and the lateral shift radio were restored to normal. The lateral and medial stress shift ratios and the Insall-Salvati ratio remained abnormal. We conclude that this technique can be recommended for the treatment of habitual or recurrent patellar dislocation in children, although hypermobility and patella alta are not fully corrected.
The aim of this study was to assess the performance of three-dimensional fast recovery fast spin-echo (3DFRFSE) for imaging of the inner ear as well as the facial and vestibulocochlear nerves. We evaluated 3DFRFSE sequences, comparing it with 3D fast spin-echo (3DFSE) in a water phantom and in 12 normal volunteers. We also examined 66 patients using 3DFRFSE sequence and assessed the visualization of their pathologies. In a water phantom study, signal intensity (SI) on 3DFRFSE was higher than that on 3DFSE at the same TR ranging from 1,500 to 6,000 ms. In normal volunteers, 3DFRFSE with TR of 2,800 ms showed comparable SI, and signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) superior to those on 3DFSE with TR of 5,000 ms. In clinical setting, 3DFRFSE was useful in demonstrating anatomic details in the labyrinth and pathologic findings of inner ear. The 3DFRFSE can provide high-resolution heavily T2-weighted images (T2WI) with shorter scan time than 3DFSE without significant disadvantage. The 3DFRFSE is a beneficial technique for evaluation of lesions in the inner ear as well as the facial and vestibulocochlear nerves.
The effects of low-intensity pulsed ultrasound (US) on the proliferation and chondroitin sulfate synthesis of cultured chondrocytes embedded in Atelocollagen gel in vitro were examined. Articular cartilage was harvested from the hip, knee, and shoulder joints of 10-week-old Japanese white rabbits. Chondrocytes isolated by collagenase digestion were embedded in type I collagen gel, Atelocollagen gel, and were cultured in Dulbecco's modified eagle's medium for 3 weeks. The US apparatus, SAFHS, was used to deliver an ultrasound signal with spatial and temporal average intensities of 30 mW/cm(2) (US group). The frequency was 1.5 MHz with a 200-microsecond tone burst repeated at 1.0 kHz. US treatments were administered for 20 min per day under culture dishes, with the medium replaced twice a week. Another group of cells was exposed to sham ultrasound as a control. Cell number, histological findings, synthesis of isomers of chondroitin sulfate, and stiffness of the chondrocyte-collagen gel composites were analyzed. US exposure promoted synthesis of chondroitin sulfate, especially chondroitin 6-sulfate, although it did not significantly enhance cell number and stiffness. In this three-dimensional culture model, these results suggest that US exposure may be clinically useful in improving the quality of chondrocyte-Atelocollagen implants for transplantation into articular cartilage defects.
We measured the stiffness of the cartilage of the human femoral condyles via an ultrasonic tactile sensor under arthroscopic control. The stiffness and the degeneration of articular cartilage were assessed in 105 knees in 74 patients (39 men, 35 women, age: 9-72 years) who underwent arthroscopic observation or surgery. Twenty-five knees suffered from traumatic cartilage injury, 14 from osteochondritis dissecans, 13 from osteoarthritis, 11 from meniscal injury and six from ligamentous injury, bipartita patellae (three knees), and symptomatic plica synovialis (two knees). The degeneration of cartilage was classified according to Outerbridge's grading system. The relationships between the stiffness and the grade of cartilage degeneration, and gender were analyzed. The stiffness of grade I (softening) and II (fissuring less than 0.5 inches in length) was significantly lower than that of intact cartilage. In contrast, the stiffness of grade IV (exposed subchondral bone) was significantly higher than that of any other group. The cartilage stiffness of the patella in women was significantly lower than that in men. The tactile sensor was useful for determining the intraoperative stiffness of healthy and diseased human cartilage in all grades.
We investigated the clinical, arthroscopic and biomechanical outcome of transplanting autologous chondrocytes, cultured in atelocollagen gel, for the treatment of full-thickness defects of cartilage in 28 knees (26 patients) over a minimum period of 25 months. Transplantation eliminated locking of the knee and reduced pain and swelling in all patients. The mean Lysholm score improved significantly. Arthroscopic assessment indicated that 26 knees (93%) had a good or excellent outcome. There were few adverse features, except for marked hypertrophy of the graft in three knees, partial detachment of the periosteum in three and partial ossification of the graft in one. Biomechanical tests revealed that the transplants had acquired a hardness similar to that of the surrounding cartilage. We conclude that transplanting chondrocytes in a newly-formed matrix of atelocollagen gel can promote restoration of the articular cartilage of the knee.
We have determined whether somatosensory evoked potentials (SEPs) were detectable after direct mechanical stimulation of normal, injured and reconstructed anterior cruciate ligaments (ACLs) during arthroscopy. We investigated the position sense of the knee before and after reconstruction, and correlated the SEP with instability. Reproducible SEPs were detected in all 19 normal ACLs and in 36 of 38 ACLs reconstructed during a period of 13 months. Of the 45 injured ACLs, reproducible SEPs were detected in 26. The mean difference in anterior displacement in the SEP-positive group of the injured ACL group was significantly lower than that in the SEP-negative group. In the reconstructed group, the postoperative position sense was significantly better than the preoperative position sense. Our results indicate not only that sensory reinnervation occurs in the reconstructed ACL, but also that the response to mechanical loads can be restored, and is strongly related to improvement in position sense.
It has recently been shown that the A/A genotype at g.-23 of the insulin gene correlates with impaired insulin secretion in response to body weight gain in subjects of European descent. To examine whether there are single nucleotide polymorphisms (SNPs) in the insulin gene associated with type 2 diabetes, all exons with their flanking sequences for 113 Japanese type 2 diabetic patients and 99 nondiabetic control subjects were analyzed using PCR direct sequencing. We have only found g.-23T --> A, 806G --> C, 1128T --> C, and 1141A --> C, which have previously been reported in alpha (A-C-C-C) and beta (T-G-T-A) alleles. The allele frequency of -23T --> A in control Japanese subjects was 97.4%, whereas that in Europeans is about 30%. The A/A genotype was found in 94 of 99 Japanese subjects (94.9%) and the allele frequencies of 806G --> C, 1128T --> C, and 1141A --> C were all 96.5%. The estimated haplotype frequencies were (A-C-C-C) (96.0%), (T-G-T-A) (2.0%), (A-G-T-A) (1.5%), and (T-C-C-C) (0.5%). No association of these SNPs or haplotypes with type 2 diabetes was evident. Thus, the A/A genotype at the g.-23 of insulin gene was generally high in Japanese subjects, which could account for the fact that they typically secrete lower levels of insulin.
A newly synthesized compound, AG-041R, 3R-1-(2,2Diethoxyethyl)-3-((4methylphenyl) amino-carbonylmethyl)-3-((4methylphenyl)ureido-indoline-2-one), is a cholecyctokinin-B/gastrin receptor antagonist, but unexpectedly magnified cartilage formation in vivo. Indeed, AG-041R is a potentially effective reagent for the repair of articular cartilage defects. To clarify its effects on chondrocytes, we studied the proliferation, matrix formation, and gene expression of rabbit primary chondrocytes cultured in type I collagen gel composites with AG-041R. Both proliferation and glycosaminoglycan synthesis were stimulated with 1 microM AG-041R, but suppressed with 10 microM. The ratio of the amounts of two chondroitin sulfate isomers, chondroitin-6-sulfate to chondroitin-4-sulfate (an indicator of cartilage maturation), increased with 1 microM but decreased with 10 microM AG-041R. Gene expression analysis showed there was no change in the relative expression levels of chondrocyte markers, Type II collagen and Aggrecan, and osteoblast and adipocyte markers, Type I collagen and PPARgamma, respectively. These findings suggest that adequate concentrations of AG-041R stimulate proliferation of chondrocytes in the matrix, without changing their differentiated characteristics.
Pancreatic cancer continues to be a major unsolved health problem in the world. The prognosis of pancreatic cancer is extremely poor with a median survival of 3-4 months and the 5-year survival being 1-4%. This poor prognosis is primarily because of a lack of effective therapies, and thus development of new treatment modalities is needed. One of these treatments could involve specific immunotherapy, for which elucidation off the molecular basis of T cell-mediated recognition of cancer cells is required. We report here six different genes and 19 immunogenic epitopes from pancreatic adenocarcinoma cells and T-cell receptor beta usage of HLA-A2-restricted CTL clones reacting to some of these epitopes. Sixteen of 19 epitopes were found to possess the ability to induce HLA-A2-restricted CTL activity in the peripheral blood lymphocytes of patients with pancreatic and also colon adenocarcinomas. These results should provide a scientific basis for the development of specific immunotherapy for pancreatic and colon cancer patients.
Accurate neuroimaging grading of gliomas is useful for management, but techniques such as MRI and CT are not sufficiently reliable. Necrosis is a consistent, decisive prognostic factor and the key diagnostic criterion for glioblastoma multiforme. MR spectroscopy (MRS) allows noninvasive measurement of metabolites in brain tumours and mobile lipids reflect necrosis. However, short echo-time (TE) spectroscopy has been required for reliable assessment of lipids, since their relaxation times are very short. Recent advances have made it possible to perform short-TE MRS. We attempted to evaluate the significance of short TE spectroscopy as part of routine imaging for diagnosis and grading of gliomas. We performed TE 30 ms MRS in 25 patients with gliomas (grade II six; grade III three; grade IV, 16) and in 19 areas of healthy white matter using proton brain examination/single voxel (PROBE/SV) and point-resolved spatially localised spectroscopy (PRESS). With short-TE spectroscopy, lipid signals were detected in all 16 tumours of grade IV, one grade II (P = 0.0002) and none of grade III (P = 0.001). TE 136 ms MRS, carried out in 20 of these cases, showed lipid signals in only four of 14 grade IV tumours and in none of the other six. N-acetylaspartate/choline (NAA/Cho) ratios were always more than 1.0 in healthy tissues and less than 1.0 in all but one of the gliomas. The mean creatine (Cr)/Cho ratio in each tumour grade was significantly lower than in the healthy tissues. The mean Cr/Cho ratio was also significantly lower in grade IV than in grade II tumours (P < .0005). Considerable overlap in Cr/Cho ratio was observed between grade II and grades III and IV gliomas at long but less so at short-TE MRS. We conclude that short-TE MRS with PROBE/SV and PRESS is of value in grading gliomas.
The purpose of this study was to clarify the efficacy of single-voxel proton magnetic resonance spectroscopy (MRS) in differentiating high-grade glioma from metastasis. Thirty-one high-grade gliomas (11 anaplastic gliomas and 20 glioblastomas) and 25 metastases were studied. Proton MRS was performed using point-resolved spectroscopy with echo times (TEs) of both 136 and 30 ms. The peaks for lipid were evaluated at short TE, and those for N-acetyl-aspartate (NAA), creatine (Cr), and choline-containing compounds (Cho) were assessed at long TE. All the tumors exhibited a strong Cho peak at long TE. Twenty-one of 25 metastases showed no definite Cr peak. The remaining 4 metastases showed NAA and Cr peaks; however, the presence of NAA and relatively high NAA/Cr ratio (1.58+/-0.56) indicated normal brain contamination. All the gliomas, except for a single glioblastoma, showed a Cr peak with (n=16) or without (n=14) NAA. At short TE all metastases and glioblastomas showed definite lipid or lipid/lactate mixture, but anaplastic gliomas showed no definite lipid signal. Intratumoral Cr suggests glioma. Absence of Cr indicates metastasis. Definite lipid signal indicates cellular necrosis in glioblastoma and metastasis, and no lipid signal may exclude metastases.
Forty-eight mature male Japanese white rabbits were subjected to unilateral resection of a segment of the gluteal muscles at the sacral origin and a section of infrapatellar ligament. Animals were killed at 1, 2, 4, and 8 weeks postoperatively, and the articular cartilage of the femoral heads was evaluated. The collagen fibrillar network of the articular surface was observed by scanning electron microscopy (SEM) using microdissection by ultrasonication. Cationized ferritin (CF) was used for the labeling of negative charges on the articular surfaces and the thickness of CF layers was observed under the transmission electron microscope. Metachromasia of the matrix decreased remarkably at 4 weeks postoperatively, and fibrillation of the articular surface was evident at 8 weeks postoperatively. Derangement and rupture of the collagen network developed as early as 1 week after surgery. The thickness of the CF layer significantly decreased at 4 weeks postoperatively. This study confirms that alterations of the articular surface, such as derangement of the collagen network and loss of the negative charge, are some of the earliest changes in osteoarthritis. In addition, application of ultrasonication with proper frequencies to the articular cartilage effects an optimal removal of mucus, with the consequent exposure of a well-preserved articular surface for SEM study.
BACKGROUND: The flow capacity of the right gastroepiploic artery graft has not been clarified. METHODS: Angiographic and echocardiographic studies were conducted in 30 patients who had undergone coronary artery bypass grafting using both the internal thoracic and right gastroepiploic arteries. The luminal diameter of the arterial grafts was measured from the postoperative angiograms. The adequacy of the myocardial blood supply from the arterial grafts was evaluated by dobutamine stress echocardiography. RESULTS: With echocardiography, 14 patients exhibited an ischemic response in the gastroepiploic artery grafted region, whereas no patients exhibited an ischemic response in the internal thoracic artery grafted area. The luminal diameter of the gastroepiploic artery and a younger age were correlated with the ischemic response observed in the dobutamine stress echocardiography. A luminal diameter of the gastroepiploic artery of greater than 2.6 mm had the highest sensitivity and specificity for a nonischemic change. CONCLUSIONS: To generate the maximal flow reserve, the luminal diameter of the gastroepiploic artery when used as a graft should be sufficiently large enough, nearly 3 mm at the anastomosis.