Biomedical subjects

M Ochi

Publications and source records attributed to M Ochi.

At least 37 records · Page 2Linked to original sources

PubMed2002

Repair of neglected Achilles tendon rupture using gastrocnemius fascial flaps.

BACKGROUND: Neglected Achilles tendon rupture is a rare disorder. In this article, we discuss the results of 10 patients with neglected Achilles tendon ruptures who were treated surgically. METHODS: Between 1980 and 1997, we treated 10 patients (6 men and 4 women) using gastrocnemius fascial flaps according to the method described by Lindholm. The mean age of the patients at the time of the operation was 51 years (range 38-57 years). They were followed-up for 26-192 months. RESULTS: There were significant differences between the American Orthopaedic Foot and Ankle Society (AOFAS) scale score before the operation (72.6+/-5.3) and the score at the most recent follow-up (98.1+/-2.5) (p<0.0001). On Cybex isokinetic strength testing, the peak torque deficiencies in plantar flexion ranged from 8% to 68% at the low setting and from 19% to 33% at the high setting preoperatively, and ranged from -9% to 17% at the low setting and from -13% to 23% at the high setting postoperatively. There were no re-ruptures. CONCLUSION: Our data indicate that the reconstructive technique using gastrocnemius fascial flaps can result in an excellent clinical and functional outcome.

Achilles Tendon↗

PubMed2002

Three-dimensional fast recovery fast spin-echo imaging of the inner ear and the vestibulocochlear nerve.

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.

Ear, Inner↗

PubMed2002

Effects of low-intensity pulsed ultrasound on proliferation and chondroitin sulfate synthesis of cultured chondrocytes embedded in Atelocollagen gel.

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.

Animals↗

PubMed2002

Arthroscopic assessment of human cartilage stiffness of the femoral condyles and the patella with a new tactile sensor.

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.

Adolescent↗

PubMed2002

Transplantation of cartilage-like tissue made by tissue engineering in the treatment of cartilage defects of the knee.

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.

Adolescent↗

PubMed2002

Induction of somatosensory evoked potentials by mechanical stimulation in reconstructed anterior cruciate ligaments.

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.

Adolescent↗

PubMed2001

Systematic search for single nucleotide polymorphisms in the insulin gene: evidence for a high frequency of -23T-->A in Japanese subjects.

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.

Adult↗

PubMed2001

AG-041R, a gastrin/CCK-B antagonist, stimulates chondrocyte proliferation and metabolism in vitro.

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.

Aggrecans↗

PubMed2001

Molecular basis of T cell-mediated recognition of pancreatic cancer cells.

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.

Amino Acid Sequence↗

PubMed2001

Diagnostic potential of short echo time MR spectroscopy of gliomas with single-voxel and point-resolved spatially localised proton spectroscopy of brain.

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.

Adolescent↗

PubMed2001

Differentiation between high-grade glioma and metastatic brain tumor using single-voxel proton MR spectroscopy.

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.

Adolescent↗

PubMed2001

Alteration of collagen network and negative charge of articular cartilage surface in the early stage of experimental osteoarthritis.

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.

Animals↗

PubMed2001

Limited flow capacity of the right gastroepiploic artery graft: postoperative echocardiographic and angiographic evaluation.

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.

Aged↗

PubMed2001

Sequential grafting of the right gastroepiploic artery in coronary artery bypass surgery.

BACKGROUND: Only a few studies have been done on sequential grafting using the right gastroepiploic artery (GEA). METHODS: Forty patients (35 males, ages 36 to 74 years) who underwent sequential grafting of the GEA were reviewed. Angiography of the GEA was performed preoperatively in all patients. GEAs with a luminal diameter greater than 2 mm at the presumptive distal anastomosis on the angiogram were used. The dissected GEA was led into the pericardial cavity through the antegastric route. We used GEAs to graft 89 branches (2.2 per patient) in the inferoposterior region. RESULTS: In 24 patients who had angiographic examinations, all the GEAs were patent, although luminal narrowing was noted in the segment between the two anastomoses in 3 patients. Eight-year actuarial survival was 92.5% and the cardiac-related event-free rate was 95%. CONCLUSIONS: Sequential grafting of the GEA can be performed effectively in selected patients. Performing preoperative angiography to assess the size of the GEA for sequential grafting is strongly recommended.

Adult↗

PubMed2001

Adequacy of flow capacity of bilateral internal thoracic artery T graft.

BACKGROUND: With the T graft configuration, multiple arterial revascularization can be accomplished using bilateral internal thoracic arteries. However, concern remains about the flow capacity of the main stem of the left internal thoracic artery (LITA). METHODS: Forty patients who underwent multiple revascularization of the entire territory of the left coronary system with a T graft were investigated. Six months after the operation, they were examined angiographically. During the same period, dobutamine stress echocardiography was performed to evaluate the adequacy of the myocardial blood supply from the T graft. The T graft revascularized two branches in 5 patients, three branches in 23, four branches in 11, and five branches in 1 of the left coronary system. Other conduits were used if revascularization was required for the right coronary system. RESULTS: Complete revascularization was achieved in the left coronary territory in all patients. The LITA main stem showed a wide lumen in all patients. Luminal narrowing was present in the distal segment of the LITA in 3 patients. The right internal thoracic artery (RITA) was patent in all patients, whereas luminal narrowing was observed in the distal segment of the RITA in 5 patients. No patient exhibited ischemic wall motion abnormality in the anteroseptal, lateral, or posterolateral region of the left ventricle where the T graft revascularized. Eight patients showed ischemic response in the inferoposterior region, that is, the territory of the right coronary artery. CONCLUSIONS: The LITA main stem, forming a T-graft configuration with the free RITA, has an adequate flow reserve to supply at least the entire left coronary arterial system with sufficient blood. Therefore, multiple coronary revascularization using the T-graft technique is feasible.

Aged↗

PubMed2001

Phosphodiesterase 3B gene expression is enhanced in the liver but reduced in the adipose tissue of obese insulin resistant db/db mouse.

Phosphodiesterase (PDE) 3B, when activated by insulin, causes a decrease in intracellular cAMP concentration. The activation of this enzyme results in the reduced output of free fatty acids (FFA) from adipocytes, and an increased lipogenesis in liver. We have recently shown that PDE3B gene expression is reduced in adipose tissues of KKAy mice. We intend to further elucidate the regulation of PDE3B in liver as well as adipose tissues in relation to the insulin resistant state. We examined PDE3B gene expression in liver and adipose tissues of obese, insulin-resistant diabetic db/db mice and also checked the effect of an insulin-sensitizing drug, troglitazone, on this gene expression. In the liver of db/db mice, PDE3B mRNA, its corresponding protein, and the associated catalytic activity were all increased by 2.1, 1.9 and 1.6-fold, respectively, over those in db/+ control mice. Histological examination revealed substantial triglyceride storage in the liver of db/db mice. Conversely, in the adipose tissue of db/db mice, PDE3B mRNA, protein, and its associated activity were all decreased by 0.38, 0.33 and 0.36-fold, respectively. Troglitazone, which has no effect on PDE3B in liver, increased the expression of this gene in adipocytes. This increase is associated with a reduction in the elevated levels of serum insulin, glucose, FFA and triglycerides. The reduced PDE3B gene expression in adipose tissues, which results in the elevation of serum FFA, could be the primary event in the development of insulin resistance in db/db mice. The enhanced PDE3B gene expression may correlate with changes in triglyceride storage in the liver of these mice.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed2001

Arthroscopic diagnosis of tibiofibular syndesmosis disruption.

PURPOSE: We have been able to diagnose tibiofibular syndesmosis injury by ankle arthroscopy, and in the present study we compare these results with the results from plain radiographs. TYPE OF STUDY: Case series. METHODS: Thirty-eight type-B (Weber system) distal fibular fractures in 38 patients were diagnosed to determine whether tibiofibular syndesmosis disruption was present. According to the Lauge-Hansen system, 16 patients had supination-external rotation fractures and 22 had pronation-abduction fractures. Standard non-weight-bearing anteroposterior radiographs and mortise radiographs were evaluated. Furthermore, ankle arthroscopy was performed on all patients. RESULTS: Tibiofibular syndesmosis disruptions were diagnosed in 16 of the 38 patients (42%) by anteroposterior radiography, 21 of 38 patients (55%) by mortise radiography, and 33 of 38 patients (87%) by ankle arthroscopy. All of the patients who were diagnosed with tibiofibular syndesmosis disruption by anteroposterior radiography and mortise radiography were also confirmed by ankle arthroscopy to have injured their tibiofibular syndesmosis. In 12 patients, ankle arthroscopy was the only method used to diagnose the tibiofibular syndesmosis disruption. CONCLUSIONS: Ankle arthroscopy excels in term of the diagnosis ratio for tibiofibular syndesmosis disruption compared with both anteroposterior and mortise radiography. Therefore, we conclude that ankle arthroscopy is necessary for the correct diagnosis of tibiofibular syndesmosis disruption.

Adolescent↗

PubMed2001

Identification of novel C253Y missense and Y864X nonsense mutations in the insulin receptor gene in type A insulin-resistant patients.

Mutations in the insulin receptor gene have been reported in cases of type A insulin resistance. We report herein two cases of type A insulin resistance, which involve some novel mutations. Case 1 is a heterozygote of the C253Y missense mutation and case 2 is a heterozygote of the Y864X nonsense mutation. In the C253Y missense mutation in exon 3, a cysteine residue is replaced with tyrosine in the cysteine-rich domain of the alpha subunit. The Y864X in exon 13 results in a truncated receptor, which is devoid of most of the beta subunit. This mutant receptor could not be expressed on a cell membrane since the transmembrane domain is missing. Other significant mutations were not found for the entire coding regions and splice/donor sites.

Adolescent↗