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Yasuhiro Morimoto

Publications and source records attributed to Yasuhiro Morimoto.

33 records · Page 2Linked to original sources
PubMed2004

Detection and significance of the characteristic magnetic resonance signals of mandibular condyles in children.

OBJECTIVE: We sought to determine the magnetic resonance imaging (MRI) characteristics of mandibular condyles in still-growing children. In addition, we also evaluated the significance of the double-contour-like structure and the conversion from red to yellow marrow characteristic of this age. METHODS: The MRI characteristics of mandibular condyles were determined by means of fast spin-echo intermediate-weighted images in subjects 9 to 14 years old. In 1 subject who developed temporomandibular joint-related clinical symptoms 1 year later, MRI was re-performed at that time. RESULTS: With the use of MRI, a total of 17 double-contour-like structures were detected in 42 temporomandibular joints of 9- to 14-year-olds, but neither 50 healthy joints of youths nor adults. In terms of bone marrow signal changes, the turning point was found to be 11 years old. In 1 subject, the double-contour-like structures were not visible on the MR images obtained 1 year after the first examination. CONCLUSION: The double-contour-like structure and the periods of conversion from red to yellow marrow may be able to be used as part of the criteria for the staging of mandibular condyle development in children.

Adolescent↗
PubMed2004

Alternation of the magnetic resonance signals characteristic of mandibular condyles during growth.

OBJECTIVE: In a previous study, we named the magnetic resonance imaging (MRI) signal that is characteristic of mandibular condyles in growing children the "double contour-like structure" (DCLS). In the current study, we evaluated the alternating appearance and disappearance of the DCLS in children as they grow to elucidate the significance of the DCLS. STUDY DESIGN: In 11 subjects who were 9-14 years old at the time of the first examination, MRI characteristics of mandibular condyles were sought from fast spin-echo intermediate-weighted images; 2 or 3 years later, repeat MRI were obtained from the same subjects. RESULTS: At the second examination, 10 of the 16 DCLSs detected at the first examination had disappeared. A significant relationship was found between the alternation of the DCLS and the bone marrow conversion from red to yellow in mandibular condyles. Alternation of the DCLS tended to coincide with eruption of the permanent maxillary second molars. The DCLS was also shown to appear as a hypersignal on T2-weighted images. CONCLUSIONS: Double contour-like structure signals in mandibular condyles appeared and disappeared as children grew, and these signal alternations may be useful as a criterion for the staging of mandibular condyle development in children. Possible constituents of the DCLS may be hypervascular loose fibrous tissue and a proliferation of cartilage.

Adolescent↗
PubMed2004

Venous abnormalities incidentally accompanied by renal tumors.

We retrospectively examined the cases of renal tumors experienced between 1993 and 2002 to evaluate the rates of incidence and preoperative identification by imaging techniques, mainly CT, of retroperitoneal venous abnormalities. Among a total of 178 renal cell carcinomas and 13 renal benign tumors, the incidence of multiplicity of renal veins was 5.3%, restricted to operatively confirmed cases (9 out of 170 cases). None of these multiplicities could be detected by preoperative radiological examinations. Other major venous abnormalities included duplications of inferior vena cava and retroaortic left renal vein and spontaneous splenorenal shunt which were all correctly diagnosed preoperatively. The incidence of these abnormalities was 0.52% (1 out of 191 cases for each). A retroperitoneal venous anomaly is common, but urologists must have sufficient knowledge about acquired retroperitoneal venous abnormalities, which seem rather uncommon, to be prepared for the potential hazards which may occur during urological operations.

Carcinoma, Renal Cell↗
PubMed2004

Significance of frequency-selective fat saturation T2-weighted MR images for the detection of bone marrow edema in the mandibular condyle.

The objective of this study was to evaluate the utility of frequency-selective fat saturation (FS) T2-weighted images (T2WI) for the detection of bone marrow edema in the mandibular condyle. MR evidence of bone marrow abnormalities was examined on the set of FS T2WI and conventional T1WI or of conventional T2WI and T1WI in 200 patients with temporomandibular joint (TMJ) related pain. Other parameters studied were TMJ effusion, disk displacement categories, and cortical bone abnormalities. The detection rate and area of bone marrow edema by FS T2WI and T1WI were significantly greater than those assessed by conventional T2WI and T1WI. The correlation between bone marrow abnormalities on FS T2WI and T1WI and pain was significantly stronger than with conventional T2WI and T1WI. This study confirms that FS T2WI is useful for the detection of the "edema pattern" in the mandibular condylar associated with TMJ-related pain.

Adolescent↗
PubMed2004

The relationship between bispectral index and electroencephalographic parameters during isoflurane anesthesia.

UNLABELLED: Bispectral index (BIS) integrates various electroencephalographic (EEG) parameters into a single variable. However, the exact algorithm used to synthesize the parameters to BIS values is not known. The relationship between BIS and EEG parameters was evaluated during nitrous oxide/isoflurane anesthesia. Twenty patients scheduled for elective ophthalmic surgery were enrolled in the study. After EEG recording with a BIS monitor (A-1050) was begun, general anesthesia was induced and maintained with 0.5%-2% isoflurane and 66% nitrous oxide. Using software we developed, we continuously recorded BIS, spectral edge frequency 95% (SEF95), and EEG parameters such as relative beta ratio (BetaRatio), relative synchrony of fast and slow wave (SynchFastSlow), and burst suppression ratio. BetaRatio was linearly correlated with BIS (r = 0.90; P < 0.01; n = 253) at BIS more than 60. At a BIS range of 30 to 80, SynchFastSlow (r = 0.60; P < 0.01; n = 3314) and SEF95 (r = 0.75; P < 0.01; n = 3339) were linearly correlated with BIS. The correlation between BIS and SEF95 was significantly better than the correlation between BIS and SynchFastSlow (P < 0.01). At BIS less than 30, the burst suppression ratio was inversely linearly correlated with BIS (r = 0.76; P < 0.01; n = 65). At BIS less than 80, burst-compensated SEF95 was linearly correlated with BIS (r = 0.78; P < 0.01; n = 3404). In the range of BIS from 60 to 100, BIS can be calculated from BetaRatio. At surgical levels of anesthesia, BIS and SynchFastSlow (a parameter derived from bispectral analysis) or burst-compensated SEF95 (derived from power spectral analysis) are well correlated. However, our results show that SynchFastSlow has no advantage over SEF95 in calculation of BIS. IMPLICATIONS: The relationship between bispectral index (BIS) and electroencephalographic parameters was evaluated during nitrous oxide/isoflurane anesthesia. At surgical levels of anesthesia, BIS and the relative synchrony of fast and slow wave (a parameter derived from bispectral analysis) or burst-compensated spectral edge frequency 95% (a parameter derived from power spectral analysis) are well correlated.

Aged↗
PubMed2004

[Anesthetic management with propofol during pheochromocytoma resection under bispectral index monitoring].

In three patients undergoing pheochromocytoma resection under propofol/fentanyl anesthesia, bispectral index (BIS) was monitored for assessment of hypnotic effect. In two patients, arterial blood concentrations of propofol were measured by high performance liquid chromatography (HPLC), and compared with those of the estimated blood concentrations. Until resection of the tumor, propofol was infused at a rate of 10 mg x kg(-1) x hr(-1). After resection of the tumor, propofol dosage was reduced to 3-6 mg x kg(-1) x hr(-1), keeping the BIS values around 60. Rapid infusion of fluid and norepinephrine was required to maintain blood pressure after removal of the tumor in two patients. In one patient, blood pressure was maintained well without rapid infusion of fluid or vasopressor. Arterial blood concentration of propofol after resection of the tumor was equal to the estimated blood concentration (3.04 vs 3.02 microg x ml(-1)) in a patient without rapid infusion of fluid. In a patient with rapid infusion of fluid, the arterial blood concentration was lower than the estimated blood concentration (2.59 vs 3.58 microg x ml(-1)). The anesthetic depth can not be estimated accurately by hemodynamic changes in the patients undergoing pheochromocytoma resection. BIS monitoring should be recommended for adjustment of propofol dosage after pheochromocytoma resection.

Adrenal Gland Neoplasms↗
PubMed2003

Cleavage of nucleolin and argyrophilic nucleolar organizer region associated proteins in apoptosis-induced cells.

To investigate the behavior of nuclear proteins in apoptotic cells, we examined the changes in nucleolin and proteins of the nucleolar organizing region during apoptosis in human osteoblastic cell lines, Saos-2 and MG63. Apoptosis was induced by treatment of these cells with okadaic acid. Proteins prepared from apoptotic cells were subjected to Western blot analysis and a modified Western blot method using silver nitrate. The anti-nucleolin antibody recognized the 110-kDa band and the staining intensity of this band decreased in the proteins prepared from the okadaic acid-treated apoptotic cells. The additional band of an 80-kDa was also detected in the proteins prepared from the apoptotic cells. Two major silver nitrate-stained bands, 110-kDa and 37-kDa, were detected among the proteins obtained from control cells. Like the Western blot analysis, the intensity of the 110-kDa silver nitrate-staining band decreased; an 80-kDa band appeared and its staining intensity increased in the lysate from the okadaic acid-treated cells. The signal intensity of the 37-kDa protein did not change in the sample from the apoptotic cells. In a cell-free apoptotic system, the 80-kDa protein was also detected and the amount of the 110-kDa protein decreased in the extract of Saos-2 cell nuclei incubated with apoptotic cytosol. The change in nucleolin in Saos-2 cells induced to undergo apoptosis was examined by an immunocytochemical procedure using the anti-nucleolin antibody and Hoechst 33342. Nucleolin was visible as dots in nucleoli in the control cells; however, it was not detected in the cells undergoing apoptosis. The dual-exposure view of Hoechst 33342 and anti-nucleolin staining cells confirmed that nucleolin had disappeared from the apoptotic nuclei of Saos-2.

Apoptosis↗
PubMed2003

Evaluation of calcified carotid artery atheromas detected by panoramic radiograph among 80-year-olds.

OBJECTIVE: To evaluate the incidence among 80-year-olds of calcified carotid artery atheromas (CCAAs) as detected on panoramic radiographs. The relationship between CCAAs and general and oral health was also evaluated. STUDY DESIGN: Six hundred and fifty-nine panoramic radiographs (262 males, 397 females), obtained from 80-year-old residents of Fukuoka Prefecture, Japan, were used for evaluation of CCAAs. RESULTS: Of 659 panoramic radiographs, 33 (5%) were noted to have CCAAs. These appeared as a radiopaque nodular mass or masses adjacent to or just below the intervertebral space between C3 and C4. CCAAs were found in 8 males and 25 females. There were marginally significant differences between males and females in CCAAs (P = 0.06). Seventy-four percent of CCAAs were detected in the right side. There appeared to be very little relationship between CCAAs and general and oral health. CONCLUSIONS: The results of this study gives further support to the idea of using panoramic radiographs to detect CCAAs. Therefore, we feel that panoramic radiographs should be evaluated not only for pathosis of the teeth and jaws, but also for other incidental findings, especially in the soft-tissue region of the neck. The findings from this study provide potentially life-saving information especially for those elderly people who are at risk for stroke.

Aged↗
PubMed2003

Are serum S100beta proteins and neuron-specific enolase predictors of cerebral damage in cardiovascular surgery?

OBJECTIVE: To examine whether serum concentrations of S100beta protein and neuron-specific enolase (NSE) are predictors of cerebral damage in cardiovascular surgery. DESIGN: Prospective clinical study. SETTING: University hospital. PARTICIPANTS: Eighteen patients with conventional cardiopulmonary bypass (CPB), 7 with selective cerebral perfusion (SCP), and 3 volunteers (blood samples). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: S100beta and NSE were measured in the blood obtained at 7 time points during and after operation. The concentrations of these markers in the blood from the surgical field and the cell-saver device, and the influence of graded hemolysis (in vitro) on the concentrations of these proteins were also examined. The mean values of S100beta in the CPB group (2.08 +/- 2.00 ng/mL) and the SCP group (1.46 +/-0.77 ng/mL) were highest after aortic declamping and after termination of SCP, respectively. The mean values of NSE in the CPB group (29.1 +/- 14.0 ng/mL) and the SCP group (31.2 +/- 13.6 ng/mL) were highest after termination of CPB and at the end of the operation, respectively. Three patients suffered from cerebral complications, but the elevation of these markers during operation was indistinguishable from those in the other patients. Peak concentrations of S100beta protein in the CPB group and NSE in the SCP group were correlated with the duration of aortic cross-clamping and CPB, respectively. S100beta protein and NSE concentrations in the blood from the surgical field were significantly larger than those in arterial blood, whereas the concentrations in the blood in the cell-saving device were not elevated. The concentration of S100beta protein was not influenced by the extent of hemolysis, whereas NSE concentration was markedly elevated by hemolysis. CONCLUSION: A large part of the increases in S100beta protein and NSE during CPB and SCP is not attributed to neuronal damage, but to contamination with the blood from the surgical field. To determine whether these markers are useful to predict neurologic complications, it will be necessary to exclude contamination from the surgical field as observed in the present study.

Aged↗
PubMed2003

The temporal profile of the reaction of microglia, astrocytes, and macrophages in the delayed onset paraplegia after transient spinal cord ischemia in rabbits.

UNLABELLED: In the present study, we sought to elucidate the temporal profile of the reaction of microglia, astrocytes, and macrophages in the progression of delayed onset motor dysfunction after spinal cord ischemia (15 min) in rabbits. At 2, 4, 8, 12, 24, and 48 h after reperfusion (9 animals in each), hind limb motor function was assessed, and the lumbar spinal cord was histologically examined. Delayed motor dysfunction was observed in most animals at 48 h after ischemia, which could be predicted by a poor recovery of segmental spinal cord evoked potentials at 15 min of reperfusion. In the gray matter of the lumbar spinal cord, both microglia and astrocytes were activated early (2 h) after reperfusion. Microglia were diffusely activated and engulfed motor neurons irrespective of the recovery of segmental spinal cord evoked potentials. In contrast, early astrocytic activation was confined to the area where neurons started to show degeneration. Macrophages were first detected at 8 h after reperfusion and mainly surrounded the infarction area later. Although the precise roles of the activation of microglia, astrocytes, and macrophages are to be further determined, the results indicate that understanding functional changes of astrocytes may be important in the mechanism of delayed onset motor dysfunction including paraplegia. IMPLICATIONS: Microglia and macrophages play a role in removing tissue debris after transient spinal cord ischemia. Disturbance of astrocytic defense mechanism, breakdown of the blood-spinal cord barrier, or both seemed to be involved in the development of delayed motor dysfunction.

Anesthesia↗
PubMed2002

Involvement of cytochrome c and caspases in apoptotic cell death of human submandibular gland ductal cells induced by concanamycin A.

In the present study, we found that a specific inhibitor of vacuolar type H+-ATPase (V-ATPase), concanamycin A, induced apoptosis in a human submandibular gland ductal cancer cell line, HSG. Immunoblot analysis revealed that cytochrome c was released from mitochondria into the cytoplasm when HSG cells were cultured with concanamycin A for 6 h. The maximum activities of caspase-3 and -9 were reached in HSG cells after 18 and 12 h culture of concanamycin A, respectively. Both caspase-3 and -9 were cleaved to an active form in HSG cells cultured with concanamycin A. Interestingly, concanamycin A decreased the level of heat shock protein 27 (HSP27) in HSG cells. Taken together, these findings suggest that apoptosis in HSG cells induced by concanamycin A is regulated by cytochrome c released from mitochondria into cytoplasm and the subsequent activation of caspases, and that HSP27 may interfere with caspase-dependent apoptotic cell death induced by concanamycin A.

Anti-Bacterial Agents↗
PubMed2002

Diagnostic image analyses of activator treated temporomandibular joint in growth and maturing stages.

This study evaluates the condylar response to activator in growth and in maturing patients using radiographs and magnetic resonance images (MRI). Seven patients (four in growth and three in maturing stages) treated for mandibular distal occlusion were studied. In all seven patients, lateral roentgen cephalograms, panoramic radiograms, and MRIs were made before and following functional treatment. All patients' mandibles advanced during treatment. Downward and forward mandibular growth was observed by superimposition of lateral cephalograms. On the condylar posterosuperior regions for both groups, double contours were sometimes observed on the panoramic radiograms following therapy. These double contours coincided with an area of high intensity in the MRIs for both groups. In the mature adult group, the double contours were more clearly observed when compared with those in the growth group. There were differences in the condylar adaptation types between the growth and mature development stages. Condylar adaptation to the newly created mandibular position was nevertheless found even in adult patients.

Activator Appliances↗
PubMed2002

[Transient complete atrioventricular block during renal transplantation].

A 25-year-old female underwent renal transplantation. The patient had no complication preoperatively except hypertension. Preoperative electrocardiogram revealed no abnormality. Anesthesia was maintained with sevoflurane. Donor kidney was perfused with University of Wisconsin (UW)'s solution (4 degrees C) after removal. Transient complete atrioventricular block appeared twice after reperfusion of the transplanted kidney. Adenosine in the UW's solution was considered the major cause of atrioventricular block in this patient. Attention must be paid to the occurrence of atrioventricular block and bradycardia shortly after reperfusion in the case where UW's solution was used for donor kidney perfusion.

Adenosine↗
PubMed2002

[Efficacy of bispectral index monitoring in improving anesthetic management, economics, and use of the operating theater].

This study was designed to assess the efficacy of bispectral index (BIS) monitoring in reducing the amount of volatile anesthetics used and improving recovery profiles. Sixty patients (ASA physical status 1 or 2) undergoing various surgical procedures under sevoflurane/nitrous oxide anesthesia were studied. The patients were randomly assigned to two groups of which anesthesia was carried out with (BIS group) or without (control group) monitoring BIS, and in the latter, anesthesiologist was blinded to the BIS values. In the BIS group, sevoflurane concentration was adjusted to achieve target BIS values between 40-60 during surgery and 60-75 during the final 15 min of the surgery. Drug usage, incidence of intraoperative complications, and recovery parameters were recorded. Demographics were similar between the groups. The BIS values in the BIS group were significantly higher compared with those of control group in which BIS values were blinded during anesthesia. The sevoflurane consumption in the BIS group (17 +/- 3 ml.h-1) was lower than control group (22 +/- 3 ml.h-1). Compared with control group, the patients in BIS group were extubated earlier and became eligible for discharge earlier from recovery room than control group. There was no significant difference in the incidence of intraoperative complications between the groups. Titrating sevoflurane concentration with BIS monitoring during anesthesia decreased anesthetic consumption and improved recovery compared with standard clinical practice.

Adult↗