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Biomedical subjects

M Ochi

Publications and source records attributed to M Ochi.

At least 109 records · Page 6Linked to original sources
PubMed1999

The regeneration of sensory neurones in the reconstruction of the anterior cruciate ligament.

We examined whether somatosensory evoked potentials (SEPs) were detectable after direct electrical stimulation of injured, reconstructed and normal anterior cruciate ligaments (ACL) during arthroscopy under general anaesthesia. We investigated the position sense of the knee before and after reconstruction and the correlation between the SEP and instability. We found detectable SEPs in all ligaments which had been reconstructed with autogenous semitendinosus and gracilis tendons over the past 18 months as well as in all cases of the normal group. The SEP was detectable in only 15 out of 32 cases in the injured group, although the voltages in the injured group were significantly lower than those of the controls. This was not the case in the reconstructed group. The postoperative position sense in 17 knees improved significantly, but there was no correlation between it and the voltage. The voltage of stable knees was significantly higher than that of the unstable joints. Our findings showed that sensory reinnervation occurred in the reconstructed human ACL and was closely related to the function of the knee.

Adolescent↗
PubMed1999

Improvement in insulin resistance and the restoration of reduced phosphodiesterase 3B gene expression by pioglitazone in adipose tissue of obese diabetic KKAy mice.

Phosphodiesterase (PDE) 3B is a key enzyme in the mediation of the antilipolytic action of insulin in adipocytes, and activation of this molecule results in a reduced output of free fatty acids (FFAs). An elevation of serum FFAs is known to cause insulin resistance in skeletal muscle and liver, which could be the primary cause of type 2 diabetes. To elucidate whether PDE3B is involved in this disease, we examined the PDE3B gene expression in epididymal fat tissues of obese insulin-resistant diabetic KKAy mice. We also examined the effect of an insulin-sensitizing drug, pioglitazone, on this gene expression. In adipose tissue of KKAy mice, PDE3B mRNA and its corresponding protein were reduced to 48 and 43% of those in C57BL/6J control mice. Basal and insulin-stimulated membrane-bound PDE activities were also decreased to 50 and 36% of those in the controls, respectively. Pioglitazone increased both PDE3B mRNA and protein levels by 1.8-fold of those in untreated KKAy mice. Basal and insulin-induced membrane-bound PDE activities were also increased by 1.6- and 2.0-fold, respectively. Pioglitazone reduced the elevated levels of serum insulin, glucose, FFAs, and triglyceride in KKAy mice. Thus, the reduced PDE3B gene expression in adipose tissues could be the primary event in the development of insulin resistance in KKAy mice, which was improved by pioglitazone possibly because of the restoration of the reduced PDE3B gene expression.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1999

Anterior laxity and MR signals of the knee after exercise. A comparison of 9 normal knees and 6 anterior cruciate ligament reconstructed knees.

9 healthy volunteers and 6 patients with anterior cruciate ligament (ACL) grafts underwent anterior knee laxity measurements and MRI examinations of their knees before and after intensive physical exercise. In the volunteer group, anterior displacement of the knee at 89 and 133 newtons of loading, measured with a KT-2000 knee arthrometer, increased after exercise, compared to before it. In addition, anterior terminal stiffness decreased at 133 newtons of anterior loading. In the ACL group, anterior displacement at 89 and 133 newtons of loading also increased, while no difference was found in anterior terminal stiffness before versus after exercise. On MRI, the signal intensity of normal ACLs after exercise was higher than before it. In contrast, the signals from the grafts showed no differences before versus after exercise. Our findings suggest that the ACL grafts are biomechanically and biochemically different from normal ACLs, even 15 months after ACL reconstruction.

Adolescent↗
PubMed1999

[A case of giant transitional cell carcinoma of the prostate].

A 69-year-old man presented with a complaint of pollakisuria, dysuria and anal pain. Digital rectal examination, transrectal ultrasonography and tumor marker of the prostate indicated a giant benign prostate hypertrophy (BPH), but urethrocystogram and magnetic resonance imaging (MRI) of the prostate was not typical of BPH. A diagnosis of giant BPH was made by transrectal needle biopsy of the prostate. However, symptoms of dysuria and anal pain became severe and then a catheter was indwelt into his bladder. A biopsy performed, 3 months later revealed transitional cell carcinoma in the specimens, but he suddenly died of pulmonary infarction.

Aged↗
PubMed1999

[Presurgical mapping with functional MRI: comparative study with transcranial magnetic stimulation and intraoperative mapping].

PURPOSE: The accuracy of preoperative mappings in patients with brain tumors near the central sulcus using functional magnetic resonance imaging (fMRI) or transcranical magnetic stimulation (TCS) was evaluated by comparative reference to intraoperative mapping. METHODS: The thumb movement was evoked by TCS for the mapping of the motor cortex. After the placement of the marker determined by TCS on the scalp, fMRI under motor tasks consisting of repetitive grasping was performed. For motor cortex activation, an axial oblique plane to maximize gray matter sampling in the rolandic cortex was employed in order to compare these different mapping techniques more precisely. Sixteen patients with brain tumors were included in this study. RESULTS: In nine patients, fMRI disclosed activation in one restricted gyrus or in the localized area around one restricted sulcus. Of these nine patients, preoperative TCS mapping corresponded closely with fMRI in six, while in the remaining three, the TCS marker fell between 1 and 2 cm apart from the fMRI-activated area. However, in these three patients, intraoperative electrocortical stimulation corresponded with the preoperative mapping with fMRI. In six patients, contigucus two gyri were activated by motor tasks. The TCS marker was disclosed on one of the two activated gyri. Of these six patients, the position of the TCS marker and fMRI-activated site corresponded with each other in four cases. They were found on the same gyrus but there was 1.0-2.0 cm distance between them in two cases. Intraoperative somatosensory evoked potential was monitored in two of these six cases. They corresponded well with the mapping by fMRI and TCS together. In only one patient, no significant activation area was obtained by fMRI because of excessive head motion during motor tasks. The TCS marker in this patient was identical with intraoperative electro-cortical stimulation mapping. CONCLUSION: For presurgical planning in patients with brain tumor near the central sulcus, comparative evaluation with fMRI and TCS is applicable and provides accurate functional mapping.

Adult↗
PubMed1999

[The case report of minimal access CABG for triple-vessel disease].

A 55-year-old male patient underwent CABG for triple-vessel disease using the minimal access approach. The procedure was performed through a limited (10 cm) left para-sternal thoracotomy using extracorporeal circulation established with a usual aortic cannula, and pulmonary arterial and right atrial drainage. The myocardium was protected by antegrade administration of cold cardioplegic solution while the aorta was being cross-clampled. The saphenous vein graft was connected sequentially to the 4 PD and OM branches, and the left internal thoracic artery was grafted to the LAD. The postoperative course was uneventful and coronary angiography showed that all three grafts were patent. The patient was discharged one week postoperatively.

Coronary Artery Bypass↗
PubMed1999

[Delineation of calf arteries using 2D-TOF MR angiography without contrast medium: efficacy of cardiac gating and leg warming].

We evaluated the image quality of non-contrast enhanced 2D-TOF MRA of the calf and the efficacy of cardiac gating and leg warming. In 10 healthy volunteers, MRA was carried out under the following four conditions: (a) usual MRA, (b) MRA with cardiac gating, (c) MRA after leg warming and (d) MRA with cardiac gating after leg warming. Although MRA with cardiac gating was not suitable, MRA after leg warming was well suited to the imaging of calf arteries. The image quality of MRA with cardiac gating after leg warming was the same as that of MRA after leg warming.

Arteries↗
PubMed1998

Sensory neurons regenerate more dominantly than motoneurons during the initial stage of the regenerating process after peripheral axotomy.

This study was designed to determine whether sensory neurons or motoneurons were dominant during the earlier stage of the regeneration process after peripheral axotomy. After transection of the right sciatic nerves of rats, epineurial end neurorrhaphy was performed. At 5, 7 and 14 days postoperatively, the nerves were re-transected at the positive pinch site, and their proximal stumps were exposed to the retrograde neurotracer, Fluoro-Gold (F-G). Seventy-two hours later, the lumbar spinal cords and the L4 and L5 dorsal root ganglia (DRG) were harvested and evaluated. The incidence and the intensity of F-G labelling in DRG were significantly higher than in anterior horns (AH). These results demonstrated that sensory neurons were more dominant than motoneurons in nerve regeneration.

Animals↗
PubMed1998

Lipoma arborescens in bilateral knee joints.

We report a case of lipoma arborescens of both knee joints. In the face of chronic joint hydrops, it is important to consider lipoma arborescens in the differential diagnosis and to try to make early diagnosis, using magnetic resonance imaging or another means of examination.

Adult↗
PubMed1998

Anatomic bases of ankle arthroscopy: study of superficial and deep peroneal nerves around anterolateral and anterocentral approach.

We studied the anatomy of the anterolateral and anterocentral portal sites for ankle arthroscopy with reference to the superficial peroneal nerve (SPN) in 29 cadavers (51 ankles) and the deep peroneal nerve (DPN) in 11 cadavers (21 ankles). In relation to the level of division into the medial and intermediate cutaneous nerves and their terminal branches, we classified the structure of the SPN surrounding the ankle into five types. We also identified the point where the SPN and the DPN cross the level of the talocrural joint. 32% of specimens had different SPN division types on the two sides and there was an average of 2 nerves at the level of the talocrural joint. Branches of the SPN were found lateral to the edge of the peroneus tertius tendon in 11.8% of specimens, and at its lateral edge in 27.5%. The DPN and some branches of the SPN were positioned around the lateral edge of the extensor hallucis longus tendon. We consider that the anterolateral portal should be made at least 2 mm lateral to the peroneus tertius tendon to avoid injury to the SPN, since the diameter of the scope is 27 mm. The anterocentral portal is unsuitable for arthroscopy due to a high risk of injury to the DPN and branches of the SPN.

Aged↗
PubMed1998

"Hexatuple" coronary bypass with in situ arterial grafts.

A fifty-seven year old male patient with severe three-vessel coronary artery disease underwent successful coronary bypass surgery in six vessels utilizing the in situ left internal thoracic and right gastroepiploic arteries. Each arterial conduit was anastomosed sequentially to as many as three coronary vessels respectively. Surgical results were excellent and the patient continues to do very well. A postoperative angiogram showed well-working arterial conduits without any anastomotic problems. Multiple sequential anastomoses of the in situ arterial conduits, although rather technically demanding, can provide better long-term results in patients requiring multiple coronary revascularization. When sequential anastomoses of the right gastroepiploic artery are being considered, the length and caliber of the artery should be evaluated by an angiogram since it varies in size compared to the internal thoracic artery.

Anastomosis, Surgical↗
PubMed1998

Bilateral piriformis syndrome after total hip arthroplasty.

We present the case of a 39-year-old man with bilateral piriformis syndrome 4 and 6 years after two cementless total hip arthroplasties, respectively. During surgical exploration, each sciatic nerve was found to be entrapped by a tense piriformis muscle and hypertrophic posterior hip capsule. The sciatic-type pain was relieved after sectioning each piriformis muscle with external neurolysis. This is the first reported case of piriformis syndrome after total hip arthroplasty.

Adult↗
PubMed1998

Adverse effects on rabbit anterior cruciate ligament after knee immobilization: changes in permeability of horseradish peroxidase.

Changes in the permeability of horseradish peroxidase (HRP) and the histology of the rabbit anterior cruciate ligament (ACL) caused by knee immobilization were studied. The knees of adult rabbits were immobilized for 2-8 weeks by a long leg cast with the knee flexed at 120 degrees, and some joints were allowed to be remobilized for 4 weeks after 6 or 8 weeks' immobilization. After 1 ml of HRP was injected into the knee joint and allowed to permeate into the ACL, the degree of permeation at the mid-portion of the ACL between femur and tibia was visualized with diaminobenzidine tetrahydrochloride. The ACL was examined histologically by light and transmission electron microscopy. Although the HRP permeated into almost the entire area of the transverse section of the non-immobilized normal ACL, as the period of immobilization increased, the extent of permeation gradually decreased. The decrease was significant from week 4 to week 6 and from week 6 to week 8. Degenerative change with necrosis of cells at the central area of the ACL was noted in the 6-week immobilization group, and the 8-week period of immobilization increased the extent of this degeneration. Although the permeation recovered in both the 6-week and 8-week immobilization groups 4 weeks after remobilization, there were fewer cells with a normal morphology in the central area in the 8-week immobilization group than in the control. These results suggest that long-term immobilization adversely affects the ACL.

Analysis of Variance↗
PubMed1998

A new guide system for posteromedial portal in arthroscopic knee surgery.

A view through the posteromedial portal is necessary to observe the posterior portion of the knee joint such as the tibial attachment of the posterior cruciate ligament (PCL) or the posterior horn of the medial meniscus, which is barely, visible through anterior portals. Especially in arthroscopic PCL reconstruction, the arthroscopic view through the posteromedial portal is indispensable for boring a tibial bone tunnel that is correctly sited. However, it is difficult to create this portal safely without cartilaginous or meniscal damage. We have produced new guidelines to facilitate the process of creating the posteromedial portal even by inexperienced hands. With a cannulated K-wire and a cannulated rod with sharp teeth, the joint capsule of the posteromedial corner can be penetrated safely with or without viewing the posteromedial corner through the anterolateral portal. Based on our experience of using this guide system, we believe it will be a great help to many orthopaedic surgeons in performing various types of arthroscopic surgery, not only for PCL reconstruction but also for arthroscopic synovectomy.

Arthroscopes↗
PubMed1998

The clinical significance of performing preoperative angiography of the internal thoracic artery in coronary artery bypass surgery.

This study was designed to clarify the clinical significance of and indications for performing preoperative internal thoracic artery (ITA) angiography in patients undergoing coronary artery bypass surgery. A total of 300 possible candidates for coronary artery bypass grafting (CABG) underwent ITA angiography during diagnostic catheterization. Semi-selective angiography of bilateral ITAs were performed by injecting contrast medium manually with a 5-F right Judkins coronary catheter. The posteroanterior view of the arteriograms was recorded on a 35-mm cine film or a cut-film. Unusual angiographic findings of the ITAs were observed in nine patients (3%). These findings included: an atrophic ITA in three patients with ipsilateral subclavian artery occlusions; enlarged ITAs giving collaterals to the lower extremities in one patient with extensive aortoiliac occlusive disease; occluded ITAs in one patient with Takayasu's arteritis and two patients with a history of CABG; and a small but nonsclerotic ITA in one patient. Atherosclerotic occlusive ITAs were found in only one patient. Thus, we concluded that routine preoperative angiography of the ITA is not necessary because it is rarely affected by atherosclerosis. However, it should be performed for any of the following reasons: a cervical or supraclavicular bruit; an upper extremity blood pressure difference of greater than 20 mmHg; an extensive aortoiliac occlusion; and certain disorders such as Takayasu's arteritis or Kawasaki disease, or a history of open heart surgery.

Adult↗
PubMed1998

New radiological finding by magnetic resonance imaging examination of the brain in Coffin-Lowry syndrome.

We used magnetic resonance imaging (MRI) to examine the brain of a typical Coffin-Lowry syndrome (CLS) patient. There were many small perivascular focal areas of hypointensity in the white matter on T1-weighted images, similar to those found in mucopolysaccharidosis or perivascular leukomalacia. However, these changes could not seen in another patient we examined. Both patients showed normal urinary mucopolysaccharide patterns with chromatographic analysis. The cause of the MRI result is not known, but it could have a heterogeneous origin, and this result could represent an important indication defining one type of CLS.

Abnormalities, Multiple↗
PubMed1998

Increase of nerve regeneration capacity by new neurotrophic pyrimidine derivative MS-430.

1. We studied whether a new neurotrophic pyrimidine compound, MS-430, can increase the regeneration length of the transected sciatic nerve in a silicone chamber gap of 14 mm. 2. The average length of regenerated myelinated axons in ten cases was 9.0+/-0 mm in the control group, 2.8+/-1.9 mm in the 1 mg/kg/day of the MS-430 group and 5.0+/-5.1 mm in the 3 mg/kg/day of the MS-430 group, indicating that the average length was significantly larger in the 3-mg group than that in the control group (P<0.05). 3. The results clearly showed that the MS-430 has promoting effects on nerve regeneration.

Animals↗