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Biomedical subjects

M Toyama

Publications and source records attributed to M Toyama.

At least 19 recordsLinked to original sources
PubMed2006

[Extracorporeal membrane oxygenation for severe respiratory failure during thoracic aortic aneurysm repair].

We present a case of successful management for severe respiratory failure during thoracic aortic aneurysm repair by applying extracorporeal membrane oxygenation (ECMO). The patient was a 71-year-old man who was diagnosed as thoracic aortic aneurysm and coronary artery stenosis. Severe respiratory failure occurred during operation because of pulmonary hemorrhage, and it was difficult to wean from cardiopulmonary bypass. ECMO was provided for improvement of oxygenation and CO2 removal. Pulmonary hemorrhage was controlled by strict management of coagulation system, and ECMO was discontinued after improvement of oxygenation on the 4th postoperative day. It is considered that early application of ECMO was effective in this case.

Aged↗
PubMed2004

MR features of masticatory muscles in adenoid cystic carcinoma involving the masticator space.

Adenoid cystic carcinoma (ACC) is known for its slow-growing but severely infiltrative nature with little tissue reaction. Although the masticatory muscles are often involved, their imaging features have not been well elucidated. We hereby report three patients with widespread ACC, which initially appeared with trismus and/or temporomandibular symptoms and involved the masticator space. Possible features of masticator space involvement are presented on magnetic resonance (MR) images. Masticatory muscle changes on MR images consisted of two aspects, namely, denervation changes and direct tumour invasion.

Adult↗
PubMed2003

Ankylosis of the temporomandibular joint developing shortly after multiple facial fractures.

A 41-year-old male patient was referred for treatment of extensive facial fractures and lateral condylar dislocations. The patient underwent open reduction and fixation under general anaesthesia. Intermaxillary fixation was released in 2 weeks and mouth opening was 21 mm. Despite postoperative physical exercises, the range of motion decreased to 10 mm at 5 weeks after the surgery. MR arthrography revealed a fibrous ankylosis in the bilateral TMJs. Coronal CT scans depicted a bony outgrowth of the left TMJ tuber. The patient underwent surgery for the ankylosis including discectomy and coronoidectomy, and removal of the bony outgrowth. An interincisal distance of 30 mm on maximal mouth opening has been maintained for 14 postoperative months. The importance of imaging assessment was emphasized for diagnosing the precise pathologic state of the ankylosis and selecting an appropriate surgical treatment of choice.

Adult↗
PubMed2003

Computed tomography of odontogenic myxoma.

OBJECTIVES: The purpose of this study was to clarify the CT features of odontogenic myxoma. METHODS: CT appearances were analysed in 17 patients with histologically verified odontogenic myxoma collected from five dental hospitals in Japan. RESULTS: On the CT images, tumour borders were generally well defined with a smooth margin both for bony and soft tissue structures in all patients. Cortical status was clearly evaluated using CT and the continuity was interrupted in nine patients. Intralesional trabeculations were observed in 13 patients. Of these 13, 6 patients showed the characteristic appearance of angular or straight trabeculations within the tumour. The trabeculations were frequently observed at the peripheral portion of the tumour. In three maxillary tumours, soft tissue margins were observed beyond the cortical margin and/or intralesional trabeculations. In 10 of the 13 lesions evaluated, the majority of the whole tumour area showed relatively lower density compared with surrounding muscles. CONCLUSION: CT clearly demonstrated characteristic features of odontogenic myxoma. CT analysis may contribute to establishing a consensus regarding the interpretation of conventional radiographic appearances in odontogenic myxoma.

Adolescent↗
PubMed2003

[Re-do coronary artery bypass grafting with the descending branch of the lateral femoral circumflex artery in a patient with chronic hemodialysis].

A 52-year-old man with hemodialysis had undergone coronary artery bypass grafting (CABG); left internal thoracic artery (LITA) to left anterior descending artery (LAD), right gastroepiploic artery (RGEA) to posterolateral branch (PL), saphenous vein graft (SVG) to diagonal artery (Dx) 5 years previously. After 3 years, angiography was performed due to recurrence of angina pectoris and revealed RGEA and SVG was totally occluded. Since repeated intervention was unsuccessful, reoperation was necessary. Therefore, we performed re-do CABG without cardiopulmonary bypass using lateral femoral circumflex artery (LFCA) as an arterial conduit for myocardial revascularization via the 6th left intercostal posterolateral thoracotomy. Postoperative angiography showed that the LFCA bypass graft was patent and supplied sufficient blood to anastomosed vessel. The patient has had no angina pectoris subsequently. We believe this procedure is useful for re-do myocardial revascularization, and LFCA deserves to be taken into account as an alternative graft in a patient with chronic hemodialysis.

Angina Pectoris↗
PubMed2003

[Minimally invasive video-assisted thoracic surgery using radially expanding trocars].

We report a new and safer access device for thoracoscopic operation. This radially expanding trocar provides a smaller incision of skin and a lesser visceral, vascular or neural injury than a conventional cannula. Therefore, most of patients undergoing this operation do not feel much pain. Moreover, this device system is more cost effective than a conventional one. We prefer and recommend this minimally invasive technique for video-assisted thoracic surgery.

Equipment Design↗
PubMed2002

Measurement of ulnar flow is helpful in predicting ischemia after radial artery harvest.

BACKGROUND: Despite a negative Allen test, some patients develop hand ischemia after radial artery harvesting. The presence of large interosseous collaterals may reduce the sensitivity of Allen test. To evaluate the combination of ulnar flow measurements and the Allen test as an effective screening technique, we performed Doppler ultrasonography during Allen's maneuver. METHODS: The Allen test was used to select candidates for harvesting radial artery from 80 patients undergoing coronary bypass surgery. RESULTS: Of 71 patients with a negative Allen test, one patient developed hand ischemia. This patient was one of six (7.5 %) possessing low ulnar flow levels (less than 40 ml/min/m(2) during compression of the radial artery). This low-flow group had a higher risk for ischemia of the 71 patients with a negative Allen test. The post-operative flow differed greatly from the pre-operative flow in eight patients (11.3 %), which was likely due to large sacrificed interosseous collaterals. CONCLUSION: Combined use of ulnar flow measurement with the Allen test appears to increase the sensitivity of the Allen test. Neither test, however, is sufficient for a group of patients with large interosseous collaterals.

Coronary Artery Bypass↗
PubMed2002

Chronic dental infections mimicking temporomandibular disorders.

BACKGROUND: Trismus and jaw pain are not only caused by temporomandibular disorders (TMD), but also by various pathologies, namely infection, trauma, or neoplasms. TMD-like symptoms, as a result of the pathologies, may be confusing to a clinician. This paper reports two cases of chronic dental infection mimicking TMD. METHODS: Two patients were initially diagnosed with, and treated for, TMD. However the patients did not respond to the treatment. Limited range of motion and jaw pain were then clinically evaluated for differential diagnoses. Laboratory examinations and computerized tomography (CT) scans were carried out to disclose any underlying lesion. RESULTS: Laboratory examination, such as, C-reactive protein helped to detect latent infection. CT scans revealed insidious chronic dental infection imitating TMD. Surgical drainage and chemotherapy resolved the symptoms. CONCLUSION: The importance of a rational diagnostic process, including clinical and laboratory examinations and radiologic imaging, cannot be over-emphasized in elucidating true cause of the symptoms.

Aged↗
PubMed2001

High yield expression and single step purification of human thionein/metallothionein.

Human metallothionein (MT), isoform 2, was expressed in Escherichia coli as an intein (protein splicing element) fusion protein in the absence of added metals and purified by intein-mediated purification with an affinity chitin-binding tag (IMPACT system). This procedure constitutes a novel and simple strategy to prepare thionein (T), the metal-free form, or MT when reconstituting T with metals in vitro. The yield was 8 mg of T or 6 mg of pure Cd(7)- or Zn(7)-MT from a 1-L culture, significantly higher than yields from any other expression system. Purified recombinant protein is indistinguishable from the native protein on the basis of its metal-binding ability, titration of its sulfhydryls, and UV and CD spectra. The MALDI-TOF mass spectrum is consistent with that of T with a free N-terminus.

Amino Acid Sequence↗
PubMed2001

Double patch technique for repairing postinfarction ventricular septal defect.

We report 2 cases in which the double patch technique was used to repair an anterior postinfarction ventricular septal defect. To do this, we modified infarct exclusion as follows: In addition to a conventional patch excluding the infarcted muscle, another small patch is used to directly close the septal defect. Gelatin-resorcin-formal glue is applied between the double patches, which prevent the glue from being washed away and enhance it to polymerize stably, thereby rapidly stabilizing the infarcted myocardium with the endocardial patch. Echocardiography immediately after operation showed the infarcted septum had completely adhered to the endocardial patch. Both patients demonstrated satisfactory postoperative hemodynamics. Although 1 patient did well, the other died 6 months postoperatively due to complications of pneumonia and gastrointestinal bleeding secondary to colon carcinoma. This double patch technique appears useful, although further experience is needed to verify its safety and efficacy.

Aged↗
PubMed2001

Colour Doppler sonographic analysis of blood-flow velocity in the human facial artery and changes in masseter muscle thickness during low-level static contraction.

Muscle oedema, which can be seen as a thickness increment by ultrasonography, is important in provoking pain and fatigue during low-level contraction. Although oedema is related to the balance of inflow and outflow of blood, there are no data on the correlation between muscle thickness change and blood-flow. Blood-flow velocities in the facial artery and the muscle thickness changes were measured by colour Doppler ultrasonography in 30 healthy volunteers during 20 min contraction with 10% of maximum force. Thickness and velocity changes both reached a peak in the initial phase of contraction. The initial change of thickness did not correlate with the velocity in the facial artery, while those immediately after exercise showed a high correlation. The velocity changes in the facial artery might depend on both the general response to contraction and local metabolic or mechanical factors in the contracted masseters.

Adolescent↗
PubMed2001

Scope-guided implantation of a stented elephant trunk in acute aortic dissection.

A reliable guide is essential for implanting a stented graft safely into a recently dissected, fragile aorta. In 4 patients with acute aortic dissection, the implantation of a stented elephant trunk was done safely using an endoscope for direct visualization. In all patients, the operation went well. The placement of a stent appears to enhance the benefit of the elephant trunk, which itself reduces the complications of an arch replacement in acute dissection.

Acute Disease↗
PubMed2001

Clinical factors of recurrent chronic subdural hematoma.

The clinical, radiological, and operative factors of recurrent chronic subdural hematoma (CSDH) were retrospectively analyzed in 116 patients with CSDH in 134 hemispheres, treated by one burr hole surgery. The correlation of recurrence was evaluated with personal and clinical factors such as age, sex, history of head injury, and interval from onset of initial symptoms to hospitalization; laboratory findings such as bleeding tendency and liver function; computed tomography (CT) findings such as hematoma density and brain atrophy; and operative findings such as additional procedures and postoperative residual air. The recurrence group (RG) included 10 hemispheres (7.5%) in 10 patients (8.6%). The interval from onset of symptoms to hospitalization was significantly shorter in the RG than in the nonrecurrence group (NRG). Headache was more frequently seen in the RG than in the NRG. Density of hematoma on CT was classified into five types: Low, iso, and high density, niveau, and mixed, and the incidence of recurrence was 0%, 2.3%, 17.2%, 12.5%, and 6.5%, respectively. Larger amounts of residual air in the postoperative hematoma cavity were associated with recurrence of CSDH. CSDH that progresses rapidly in the acute stage and appears as high density on preoperative CT is associated with a high incidence of recurrence. Intraoperative air invasion to the hematoma cavity should be avoided to prevent recurrence.

Aged↗
PubMed2001

[Positive illusions in Japanese students].

The purpose of this study was to examine positive illusion phenomena among Japanese students. In Study 1, students were asked to rate themselves and the average same-sex student of their university or vocational school, in terms of their personality, optimism about the future, and belief in personal control. Results indicated that participants showed positive illusions in their ratings of agreeableness, conscientiousness, optimism for negative future events, and personal control. However, negative illusions were found in their ratings of extraversion, openness to experience, and appearance. In Study 2, participants were asked to compare themselves with the average same-sex student of their university or vocational school. Results were similar to those of Study 1. Cultural factors appeared to be responsible for those positive and negative illusions.

Culture↗
PubMed2001

[Neuro-Behcet disease mimicking a thalamic tumor].

A case of neuro-Behcet disease presenting as a thalamo-lenticular expanding lesion is reported. A 41-year-old female was admitted with mental deterioration and right hemiparesis. She had been suffering from recurrent oral and genital ulcers and erythema nodosum for several years before admission. Neurological examination on admission revealed poor mental activity, dysarthria and right hemiparesis. Lumbar puncture showed CSF pleocytosis. CT and MRI revealed a thalamo-lenticular expanding lesion. CT showed a homogeneous hypodense lesion of the left lenticulothalamic region, which was enhanced in the central part, exerting a mild mass effect. MRI also revealed the lesion better. The T2 weighted images showed a high intensity signal in the left thalamo-lenticular region and the left peduncle. The T1 weighted images showed a low signal in the corresponding areas with a central enhancement with Gd-DTPA. EEG, SPECT and angiography indicated normal findings. Histologic study of the brain biopsy tissue ruled out a tumor but did not show any specific diagnosis. The patient improved with steroid therapy. In conclusion, the clinical and radiological presentation of neuro-Behcet disease can mimic a cerebral tumor. In such cases, stereotactic biopsy is useful to exclude suspicion of a cerebral tumor.

Adult↗
PubMed2001

[Calf flow reserve measured by venous-occlusion near-infrared spectroscopy: relationship to exercise tolerance].

OBJECTIVES: The correlations between calf flow reserve evaluated with venous-occlusion near-infrared spectroscopy, air plethysmography or skin laser Doppler flowmetry were investigated in patients with cardiovascular diseases. The relationships to exercise tolerance during upright bicycle exercise were also examined. METHODS: The calf flow reserve (blood flow after 5 min of arterial occlusion/basal blood flow) evaluated by the above three methods and peak oxygen uptake (peak VO2) on bicycle exercise were measured in 24 male patients (mean age 65.0 +/- 7.7 years, left ventricular ejection fraction 24-86%). RESULTS: There was a good correlation between flow reserve by near-infrared spectroscopy (8.0 +/- 3.8) and air plethysmography (7.9 +/- 3.1; r = 0.90). However, there was a weak correlation between flow reserve by near-infrared spectroscopy and skin laser Doppler flowmetry (3.4 +/- 1.7; r = 0.42). There was a good correlation between flow reserve by near-infrared spectroscopy and peak VO2 (r = 0.69), or flow reserve by air plethysmography and peak VO2 (r = 0.53). However, there was no significant correlation between flow reserve by skin laser Doppler flowmetry and peak VO2 (r = 0.18). CONCLUSIONS: Calf flow reserve evaluated by venous-occlusion near-infrared spectroscopy relates to the flow reserve in the muscle tissue and is minimally affected by the flow reserve in the skin. The flow reserve in the muscle tissue is related to exercise tolerance, but the flow reserve in the skin is not, in patients with cardiovascular diseases.

Aged↗
PubMed2001

Clinical studies of bioabsorbable poly-L-lactide sternal coaptation pins.

BACKGROUND: Median sternotomy has become the most commonly used incision in cardiac surgery. Since sternal dehiscence, however, is a major complication, we used bioabsorbable poly-L-lactide (P-L-LA) sternal coaptation pins for sternal closure to prevent it. METHODS: From February 1998 to October 1999, 99 patients (64 men, 35 women; mean age, 63+/-1.2 years) underwent median sternotomy for cardiac surgery using sternal coaptation pins. Nineteen patients had diabetes mellitus and seven had renal failure. In closure, two sternal pins were inserted into the bone marrow of the sternum, one into the manubrium, the other into the body, and the sternum was sutured with five stainless steel wires. RESULTS: Five patients died in the hospital. The causes of death were cardiac failure in two patients, respiratory problem in two and perforation of the stomach in one. The average length of hospitalization was 2 4.5+/-2.5 days. Sternal dehiscence occurred in one patient and mediastinitis in four. There was no bleeding from the bone marrow and no complication related to the use of the sternal pins. CONCLUSIONS: P-L-LA sternal pins were easy to insert and may be effective in preventing dehiscence of the sternum.

Absorbable Implants↗