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M Ochi

Publications and source records attributed to M Ochi.

At least 55 records · Page 3Linked to original sources

Effects of ischemic preconditioning and synchronized coronary venous retroperfusion in an off-pump coronary artery bypass grafting model.

Off-pump coronary artery bypass grafting (CABG) has become a popular procedure. However, temporary occlusion of the target vessel is sometimes a threat to the patients. Although ischemic preconditioning (IP) has been proposed to reduce myocardial injury, its effects remain controversial. The coronary veins represent an alternate route for delivery of therapeutic agents and arterial blood to the acutely ischemic myocardium. The aim of this study was to investigate the protective effect against myocardial ischemia and reperfusion injury of combined IP and synchronized coronary venous retroperfusion (SCVR) in an off-pump CABG model. Twenty-one pigs were assigned to 3 groups of 7 animals. In the control group, the left anterior descending coronary artery (LAD) was occluded for 45 min followed by 2 h of reperfusion using a left intrathoracic artery (LITA) bypass circuit. In the IP group, LAD occlusion was done for 5 min with 15 min of reperfusion, followed by 45 min of LAD occlusion. In the SCVR group, pretreatment before LAD occlusion was the same as in the IP group. Then, SCVR was commenced just after the start of LAD occlusion for 45 min. The percent systolic shortening of ischemic myocardium (measured by sonomicrometry) after reperfusion via the LITA was significantly (p < 0.001) greater in the SCVR group (14.6 +/- 3.3%) than in the control group (-1.6 +/- 5.6%, 95%CI: -24.3 - -8.1) or the IP group (0.7 +/- 8.0%, 95%CI: -22.0 - -5.8) after 30 min of reperfusion, and this difference persisted throughout the reperfusion period. Infarct size (expressed as a percentage of the area at risk) was significantly (p < 0.001) smaller in the SCVR group (2.4 +/- 2.7%) than in the control group (83.0 +/- 2.3%, 95%CI: -99.0 - -62.4) or the IP group (42.0 +/- 23.0%, 95%CI: -58.0 - -21.3). Combined SCVR and IP had a potent myocardial protective effect in the present off-pump CABG model. This method may be clinically feasible and may be able to prolong a safe coronary occlusion.

Animals↗

Current concepts in tissue engineering technique for repair of cartilage defect.

Hunter's observation in 1743 that cartilage "once destroyed, is not repaired," has not essentially changed for 250 years. At present, there is no well-established procedure for the repair of cartilage defect with articular cartilage, which has the same biochemical and biomechanical properties as the surrounding normal intact cartilage. In 1994, transplantation of human autologous chondrocytes in suspension, as reported by Brittberg et al., provided a potential procedure for articular cartilage repair. We have improved their procedure and developed a new technique which creates new cartilage-like tissue by cultivating autologous chondrocytes embedded in Atelocollagen gel for 3 weeks before transplantation. These improvements maintained the chondrocyte phenotype, evenly distributed chondrocytes throughout the osteochondral defects, and decreased the risk of leakage of grafted chondrocytes into the defects. Good clinical results suggest that this technique should be a promising procedure for repairing articular cartilage defect.

Adolescent↗

A case of superficial peroneal nerve injury during ankle arthroscopy.

We report a case of superficial peroneal nerve (SPN) injury caused by ankle arthroscopy. A 20-year-old woman underwent arthroscopy on her right ankle because of chronic ankle pain after a sprain. After arthroscopy, the patient complained of pain on the dorsum of her right foot and felt a radiating pain from the anterolateral portal to the dorsomedial aspect of her foot. Eight months after arthroscopy, we found that a neuroma had developed on the intermediate dorsal cutaneous nerve, and performed neurolysis of the SPN. Her symptoms gradually decreased after surgery, and had disappeared by 45 months. To avoid such an injury of the SPN, the safest placement of the anterolateral portal is necessary and is, according to our previous anatomic study, 2 mm lateral to the peroneus tertius tendon.

Adult↗

Expression of cytokines after meniscal rasping to promote meniscal healing.

PURPOSE: We have developed a new surgical procedure of rasping a meniscal surface to repair a tear in the avascular zone. This procedure stimulates vascular induction to the tear, resulting in meniscal healing. The purpose of this study was to elucidate the mechanism of vascular induction and meniscal healing. TYPE OF STUDY: Randomized trial. METHODS: A full-thickness longitudinal tear of 5 mm in length was created in the avascular zone of the anterior segment of both medial menisci of rabbits. Meniscal rasping of about 0.5 mm in depth was then done on the femoral surface of the left meniscus from the parameniscal synovium to the inner portion including the longitudinal tear, and the right meniscus was left untreated as a control. After surgery, at 1, 7, 14, 28, 56, and 112 days, 4 rabbits were killed, both medial menisci were resected, and immunohistochemical staining with monoclonal antibodies was used to quantify expression of interleukin-1alpha (IL-1alpha), transforming growth factor-beta1 (TGF-beta1), platelet-derived growth factor (PDGF), and proliferating-cell nuclear antigen (PCNA) on the femoral surface of the menisci. A positive ratio of immunostaining was encountered. RESULTS: The positive ratio of IL-1alpha, TGF-beta1, PDGF, and PCNA on the rasped surface area reached its peak at 1, 7, 14, and 7 days, respectively, after surgery, and thereafter gradually declined. Although the time course of the positive ratio was different among these cytokines, the positive ratio on the rasped surface was significantly higher than that on the control surface at the early stage of the observation period. CONCLUSIONS: The cytokine network on the rasped meniscal surface appears to be the key to explaining the mechanism of vascular induction and meniscal healing by meniscal rasping.

Animals↗

Effects of hyaluronic acid and basic fibroblast growth factor on motility of chondrocytes and synovial cells in culture.

The capacity of chondrogenic precursor cells to migrate and proliferate in an injured area is considered to be essential for cartilage repair. We examined cell motility of chondrocytes and synovial cells in monolayer culture and the chemokinetic effects of hyaluronic acid (HA) and basic fibroblast growth factors (bFGF) on these cells. The velocity of chondrocyte migration was accelerated by giving bFGF and simultaneously administering of both HA and bFGF, but it was not affected by HA alone. The velocity of synovial cell migration was increased by HA, but not by bFGF. HA had a chemokinetic effect on synovial cells and bFGF had the same effect on chondrocytes. Treatment with exogenous HA and bFGF may be of value for repairing articular cartilage injury by recruiting chondrogenic cells and promoting migration of chondrocytes in the cartilage tissue.

Animals↗

Intraosseous hypertension and venous congestion in osteonecrosis of the knee.

To determine whether an angiogenic factor affects the pathogenesis of the idiopathic osteonecrosis of the medial femoral condyle, intraosseous pressure and venogram in 11 knees with osteonecrosis were compared with intraosseous pressure and venogram in 11 knees with the medial type of osteoarthritis. Patients were matched by age, gender, obesity index, blood pressure, tibiofemoral angle, and clinical evaluation. The intraosseous pressure of the medial condyle of the knees with osteonecrosis (62.8 +/- 27.3 mm Hg) was significantly higher than that in the lateral condyle of the knees with osteonecrosis (25.4 +/- 18.9 mm Hg) and those of both condyles of the knees with osteoarthritis (medial, 31.6 +/- 17.4 mm Hg; lateral, 29.5 +/- 11.0 mm Hg). In contrast, there was no significant difference in the pressure between the medial and lateral condyles of the knees with osteoarthritis. Venography showed a marked disturbance of venous drainage in all patients with osteonecrosis. In addition, the average clearance time of the medium in the medial femoral condyle was significantly more prolonged in patients with osteonecrosis (17.7 +/- 6.1 minutes) than in patients with osteoarthritis (5.5 +/- 1.6 minutes). These data support the hypothesis that venous stasis within the medullar canal in the condyle increases intraosseous pressure and decreases arteriovenous pressure difference, leading to osteonecrosis.

Aged↗

Increased uptake of 99Tcm-ethyl cysteinate dimer in patients with brain tumours.

We performed 229 99Tcm-ethyl cysteinate dimer (ECD) single photon emission tomography (SPET) studies in 185 patients with brain tumour. Increased uptake of the tracer was observed in 11 cases. In six of these 11 patients, focal intense activity was seen in the area surrounding the tumour. Five of these six patients had episodes of seizure, and ictal SPET showed further increased uptake in the area of hyperperfusion in one patient. Hyperperfusion surrounding the tumour might be related to seizure. In the remaining five patients, increased accumulation was seen in the tumour. Three of these five patients had a discrepancy between 99Tcm-ECD SPET and 201Tl SPET imaging. There could be some difference in the mechanism of accumulation in the tumour between 99Tcm-ECD and 201Tl.

Adolescent↗

Developmental changes in cerebrospinal fluid concentrations of monoamine-related substances in patients with dentatorubral-pallidoluysian atrophy.

Using a Coulochem electrode array system, we investigated the developmental changes of monoamine-related substances in patients with dentatorubral-pallidoluysian atrophy. The patterns observed in the developmental changes of tryptophan, tyrosine, homovanillic acid (HVA), 3-O-methyldopa, and 3-methoxy4-hydroxyphenyl glycol (MHPG) in patients with dentatorubral-pallidoluysian atrophy are quite different from those in control subjects. These abnormal developmental changes in monoamine-related substances may be implicated in age-related differences in clinical symptoms of dentatorubral-pallidoluysian atrophy.

Adolescent↗

Computed tomographic evaluation of the position of the leg for mortise radiographs.

We investigated the most advantageous internal rotation angle of the leg for mortise radiographs. One hundred and twenty-eight feet of 64 healthy volunteers with no histories of ankle or foot pathology (72 feet of 36 males, 56 feet of 28 females) were examined. The subjects had an average age of 29 years (range, 19 to 51 years), average height of 167 cm (range, 157 to 181 cm), and average foot length of 25 cm (range, 23 to 27 cm). We obtained a plain axial view at the level of the central patella and 5 mm proximal to the tibial plafond using computed tomography, and investigated the inclination angle of the distal tibiofibular joint to a horizontal plane, regarding it as a mortise angle. The mean mortise angle was 19.1 +/- 5.0 degrees. However, two peaks were observed at around 15 degrees and 20 degrees. This indicated that the mean mortise angle of the males was 21.2 +/- 4.6 degrees, and the mean mortise angle of the females was 16.4 +/- 4.1degrees, with a significant difference between the males and the females' mortise angle (P < 0.0001). There was no correlation between the mortise angle and the height (P = 0.899 in the males, and P = 0.871 in the females), nor between the mortise angle and the foot length (P = 0.359 in the males, and P = 0.512 in the females). Therefore, we concluded that the internal rotation angle of the leg for mortise radiography should be generally set up at about 20 degrees on males and 15 degrees on females.

Adult↗

Celiac artery aneurysm: a case evaluated preoperatively with three-dimensional computed tomographic angiography.

In a 63-year-old woman computed tomography (CT) incidentally detected a celiac artery aneurysm approximately 3 cm in diameter. While conventional angiography suggested that the splenic artery and common hepatic artery arose from the celiac artery aneurysm, three-dimensional CT angiography indicated that the aneurysm involved only the mid portion of the celiac artery. Considering the risk of eventual aneurysm rupture, surgery was performed. Aneurysmectomy and devascularization of hepatic, splenic, and celiac arteries were carried out following complete cross-clamping of the celiac artery. The distal segment of the celiac artery was directly anastomosed to the proximal segment in an end-to-end fashion. Histologically, the aneurysm wall showed atheromatous changes. Contrast-enhanced abdominal CT confirmed complete removal of the celiac artery aneurysm, and postoperative angiography confirmed good arterial flow. The patient recovered uneventfully after surgery, with normalization of transiently abnormal hepatic function parameters. In this case of celiac artery aneurysm, three-dimensional CT angiography was found to be valuable in determining the relationships of the aneurysms to important arterial branches.

Aneurysm↗

Assessment of abdominal aortic aneurysms using a cone-beam CT system: an experimental phantom study and an initial clinical evaluation before and after stent-graft treatment in patients with an abdominal aortic aneurysm.

The aim of this study is to conduct a quantitative analysis of cone-beam CT (CBCT) images using a phantom, and then to evaluate the clinical usefulness of CBCT in the assessment of abdominal aortic aneurysms (AAA) before and after stent-grafting, both qualitatively as well as quantitatively. The phantom used in this study was a rectangular plate made of an acrylic resin, which contained eight through-holes to mimic blood vessels. Each columnar cavity was filled with contrast media and the diameter of each was then measured using a cone-beam multiplanar reformation/curved planar reformation (CB-MPR/CPR) technique, and the results were compared with the corresponding results obtained by actual measurement. In the clinical assessment, nine patients with AAA (consisting only of males with an average age of 68 years old: 56 approximately 80) were enrolled. The clinical qualitative analysis of CBCT consisted of: 1) for the pre-operative state, the shape of the aortic aneurysm, the relationship between the aneurysm and the aortic branches, and 2) for the post-operative state, the shape of the stent and any endoleakage present. The clinical quantitative analysis of CBCT included, for the aneurysm, its inflection angle, its maximum diameter, the diameter of the proximal and distal necks, and the distance of these two necks from specific reference points. The quantitative analysis using the phantom showed no significant differences between the results based on CB-MPR/CPR and those obtained by actual measurement. In the clinical qualitative analysis three-dimensional CBCT (3D-CBCT) depicted the anatomical relationship between the aneurysm and the aortic branches well, an accomplishment that was not possible by conventional angiography. Cone-beam maximum intensity projection (CB-MIP) was as good in tracing the migration and deformation of the stent following endovascular intervention as plain radiograms and conventional angiograms. CB-MPR/CPR enabled us to obtain any cross-sectional image of the aorta desired, including a curved, longitudinal cross-section of the aorta. Thus, with the CB-MPR/CPR technique it is easy to determine the distance of the proximal and distal necks of the aneurysm, and the inflection angle, and those results were not significantly different from those obtained by angiography. The diameter of the aneurysm, and the diameter of the proximal and distal necks as measured by CB-MPR/CPR images were significantly different from those obtained by conventional contrast enhanced-CT (p<0.05). This suggests that CB-MPR/CPR yields a cross-sectional view that is more perpendicular to the longitudinal direction of the aorta than that given by conventional contrast enhanced-CT, and thus provides a more accurate cross-sectional image of the aneurysm than the latter. We conclude that, in the experimental phantom study CBCT had a high quantitative reliability, and that, in the clinical study CBCT provided useful information for both qualitatively and quantitatively evaluating AAA before and after stent-grafting.

Aged↗

Adipocyte-specific reduction of phosphodiesterase 3B gene expression and its restoration by JTT-501 in the obese, diabetic KKAy mouse.

OBJECTIVE: Phosphodiesterase (PDE) 3B is a key enzyme involved in the anti-lipolytic action of insulin in adipocytes. PDE3B activation results in a reduced output of free fatty acids (FFA), whereas elevated serum FFA is known to cause insulin resistance. We have recently reported that reduced PDE3B gene expression is restored by treatment with pioglitazone, in the adipose tissues of obese, insulin-resistant diabetic KKAy mice. To determine whether the altered PDE3B gene expression is specific for adipocytes, the expression of this gene in liver and epididymal fat tissues of KKAy mice was examined. The effect of JTT-501, another peroxisome proliferator-activated receptor (PPAR)gamma ligand, which is different from thiazolidinedione, was also examined. METHODS: PDE3B mRNA and protein were quantified by an RNase protection assay and Western blotting respectively. Membrane-bound PDE activities were also measured. RESULTS: In adipose tissues of KKAy mice, PDE3B mRNA, protein and membrane-bound PDE activity were reduced to 47%, 57% and 51% respectively relative to those in C57BL/6J control mice. JTT-501 increased PDE3B mRNA, protein and membrane-bound PDE activity by 2.2-, 1.6- and 1.7-fold respectively over those of untreated KKAy mice. In the liver, PDE3B gene expression remained unchanged in KKAy mice, and was not affected by JTT-501. JTT-501 reduced the elevated levels of serum insulin, glucose, FFA and triglyceride in KKAy mice. CONCLUSIONS: PDE3B gene expression was specifically reduced in the adipose tissues of KKAy mice. JTT-501 restored this reduced gene expression with an accompanying improvement in elevated serum FFA and insulin resistance.

3',5'-Cyclic-AMP Phosphodiesterases↗

[A case of cerebral arteriovenous malformation complicated with intracerebral hemorrhage after endovascular embolization].

We reported a case of cerebral arteriovenous malformation (AVM), complicated with intracerebral hemorrhage (ICH), after endovascular embolization. A 51-year-old male suffered from intraventricular hemorrhage due to a rupture of an intranidal aneurysm on October 4, 1999. The first embolization procedure for the aneurysm and a part of the nidus was performed with 2-hydroxyethyl methacrylate-methyl methacrylate (HEMA-MMA) and Liquid coil on day 21 after admission. On day 28, a second embolization was carried out for the residual nidus. Although most of the nidus was obliterated, the patient became comatose 10 hours after the second embolization. Computed tomography revealed a massive ICH in the right parietal lobe, and he underwent emergency evacuation of the hematoma. During the surgery, HEMA-MMA was seen in a draining vein. This caused venous stasis. Although the patient gradually improved postoperatively, he became comatose again because of a recurrence of ICH on day 36. Evacuation of the hematoma and removal of the nidus were performed again. The operative specimen showed AVM embolized by HEMA-MMA with non-specific inflammation and partial inflammatory degeneration of the vascular wall. Hemodynamic change such as venous stasis or elevated pressure of the feeding artery seemed to be the cause of the hemorrhage. Multi-staged embolization with longer intervals and intraoperative flow control were regarded as crucial for avoiding delayed hemorrhage.

Aneurysm, Ruptured↗

[A case of spinal dural AVF treated by endovascular embolization].

Here we report a case of spinal dural arteriovenous fistula(AVF) treated by endovascular embolization. A 58-year-old female presented with progressive intermittent claudication and numbness of the lower extremities. MRI showed swelling of the spinal cord with intramedullary high signal intensity on T2-weighted image and intramedullary enhancement, suggested spinal cord myelopathy. Myelography demonstrated the dilated serpentine vessels in the subarachnoid space and focal filling defect. Angiography showed spinal dural AVF fed by bilateral lateral sacral artery. The draining vein was posterior spinal vein. Endovascular embolization using liquid material was performed under general anesthesia. The injection of glue included the distal feeding artery, the shunt itself and the initial part of draining vein. A complete cure was achieved, with a normal postoperative angiogram. MRI returned to normal with complete disappearance of T2 high signal, cord enlargement and enhancement by contrast medium. It was suggested that venous congestion induced the transient spinal ischemia, manifested as intermittent claudication. Endovascular embolization using liquid material was safe and quite effective for spinal dural AVF.

Central Nervous System Vascular Malformations↗

Adenosine A(2A) receptor antagonists KF17837 and KW-6002 potentiate rotation induced by dopaminergic drugs in hemi-Parkinsonian rats.

The effects of novel adenosine A(2A) receptor antagonists KF17837 ((E)-1,3-dipropyl-8-(3,4-dimethoxystyryl)-7-methyl-3, 7-dihydro-1H-purine-2,6-dione) and KW-6002 ((E)-1,3-diethyl-8-(3, 4-dimethoxystyryl)-7-methyl-3,7-dihydro-1H-purine-2,6-dione), on rotational behavior induced by apomorphine or L-DOPA (L-3, 4-dihydroxyphenylalanine) were investigated in rats with unilateral 6-hydroxydopamine lesions. Both KF17837 and KW-6002 slightly induced rotational behavior per se. However, KF17837 and KW-6002 significantly increased the total counts of turning induced by apomorphine at doses of 3 mg/kg, p.o. and 10 mg/kg, p.o., and at doses of 1 mg/kg, p.o. and higher, respectively. KF17837 and KW-6002 also potentiated the rotational behavior induced by L-DOPA at a dose of 3 mg/kg, p.o. Furthermore, i.c.v. injection (10 microg/20 microl) of a selective adenosine A(2) receptor agonist CGS 21680 [2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamidoaden osine] partially prevented the rotational behavior induced by apomorphine and this inhibition was reversed by KW-6002 (1 mg/kg, p.o.). The increase in total counts of apomorphine-induced turning by the adenosine A(2A) receptor antagonists seems to be mainly attributable to prolongation of turning duration rather than enhancement of intensity. These results suggest that these adenosine A(2A) receptor antagonists may be useful to ameliorate shortening in the duration of dopaminergic drug response in patients with advanced Parkinson's disease.

Animals↗

A conditioning lesion promotes in vivo nerve regeneration in the contralateral sciatic nerve of rats.

A conditioning lesion in the sciatic nerve increases in vivo axonal regeneration in the nerve after a second transection. We studied whether this increased regeneration also occurs in the contralateral nerve. The left sciatic nerve was transected and sutured in Wistar rats; the nerve was exposed but not transected in controls. After 5 days, the right sciatic nerves of all rats were transected and sutured. Neuronal regeneration was measured at 0, 1, 3, 5, and 7 days with the pinch test and histological staining. IL-1beta and TGF-beta1 expression was also measured. The initial delay in the experimental group was significantly shorter, but the regeneration rates were the same. The expression of IL-1beta and TGF-beta1 in the right dorsal root ganglia was significantly higher in the experimental group. Nerve injury enhances cytokine expression in the contralateral dorsal root ganglion and promotes contralateral nerve regeneration in vivo by shortening the initial delay.

Animals↗

Human chondrocyte proliferation and matrix synthesis cultured in Atelocollagen gel.

To evaluate the potential of Atelocollagen gel as a carrier for chondrocyte transplantation, histological and biochemical characteristics of the chondrocytes in gel culture were compared with those in conventional monolayer cultures. Articular chondrocytes from 20 patients were isolated by enzyme digestion, embedded in Atelocollagen gel, and cultured for up to 4 weeks. The effects on proliferation, morphological changes, and synthesis of proteoglycans were analyzed by cell counts, light and electron microscopy, and measurement of isomers of chondroitin sulfates. Chondrocytes embedded in the Atelocollagen gel gradually proliferated and produced chondroitin 6-sulfate, maintaining the chondrocyte phenotype for up to 4 weeks. In contrast, although monolayer chondrocytes increased in number, most could be characterized as being fibroblast-like cells with a reduced capability of producing chondroitin 6-sulfate. The results suggest that Atelocollagen gel permitted a gradual proliferation and matrix synthesis of chondrocytes and maintaining its phenotype. Atelocollagen gel represents an important carrier for the clinical application of cultured chondrocyte transplantation for repair of cartilage defects.

Biocompatible Materials↗