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Yasuhiro Morimoto

Publications and source records attributed to Yasuhiro Morimoto.

At least 19 recordsLinked to original sources
PubMed2006

Relationship of chewing-stimulated whole saliva flow rate and salivary gland size.

OBJECTIVE: We have recently reported that unstimulated whole saliva flow rates (UWSFR) correlate positively with salivary gland sizes and body profiles of weight and body mass indices. In the present study, the correlations of chewing-stimulated whole saliva flow rates (CWSFR) with salivary gland sizes and the body profiles were investigated, and the results were compared with those of UWSFR. DESIGN: Saliva samples were collected from 24 healthy young males and 26 females by the spitting method while chewing paraffin and the CWSFRs were measured. UWSFR and the estimated sizes of the three major salivary glands in our previous study were used. RESULTS: The CWSFRs in all subjects and in males correlated positively with UWSFR, but not in females. The CWSFRs in all subjects correlated positively with parotid and/or submandibular gland sizes, weights and body mass indices, just as with UWSFR; however, the correlation coefficients with salivary gland sizes were smaller than those of UWSFR. In contrast to the results of UWSFR, the correlation coefficients of the CWSFRs with parotid gland sizes in all subjects were larger than those with the sizes of the submandibular glands. The CWSFRs in males correlated only with parotid gland sizes, and those in females did not correlate with any of the parameters. CONCLUSIONS: The results suggest that the larger the size of the salivary glands, the greater the CWSFR, at least in males.

Adult↗
PubMed2006

Can the presence of carotid artery calcification on panoramic radiographs predict the risk of vascular diseases among 80-year-olds?

OBJECTIVE: The purpose of this study was to evaluate whether subsequent vascular diseases and related death could be predicted by the presence of carotid artery calcification detected on panoramic radiographs among elderly persons. STUDY DESIGN: We evaluated 659 panoramic radiographs from 262 male and 397 female 80-year-old subjects and their general medical examination data to assess the relationship between the presence of carotid artery calcification and vascular disease risk at baseline examination. Of these subjects, the occurrence of vascular diseases within 5 years after baseline examination was examined in 191 subjects. Further, the causes of death were examined in 108 subjects who died within 5 years after baseline examination. RESULTS: There was a significant difference in the history of past vascular diseases among subjects with and without carotid artery calcifications; however, no significant difference in the occurrence of subsequent vascular diseases was found among them. Further, there was no significant difference in the occurrence of vascular disease-related death within 5 years after baseline examination among subjects with and without carotid artery calcifications (P = 0.719). CONCLUSION: Our results suggest that the presence of carotid artery calcifications on panoramic radiographs may be related to the history of past vascular diseases; however, this is not a useful marker for subsequent vascular diseases and related death among 80-year-olds.

Aged, 80 and over↗
PubMed2006

Changes in electroencephalographic bicoherence during sevoflurane anesthesia combined with intravenous fentanyl.

With the introduction of bispectral index (BIS) as a measure of a patient's sedation during general anesthesia, attention has been directed toward bispectral analysis of electroencephalography (EEG). In the present study we evaluated the relationship between EEG bicoherence and sevoflurane concentration. Sixteen ASA physical status I-II patients scheduled for elective abdominal surgery were enrolled in the study. Anesthesia was induced with 5% sevoflurane and maintained with sevoflurane and oxygen (50%). Just before surgery, IV fentanyl (2 microg/kg) was given and then continuously infused (2 microg x kg(-1) x h(-1)). Using software we developed, EEG bicoherence, BIS, and 95% spectral edge frequency (SEF95) were recorded at end-tidal sevoflurane concentrations of 0.5%, 0.8%, 1.1%, 1.4%, 1.7%, 2.0%, and 2.3%. Under light anesthesia, EEG bicoherence values were low. With increasing sevoflurane concentrations, 2 peaks of bicoherence emerged along the diagonal line (f1 = f2). Both the first (at around 4 Hz) and second (at around 10 Hz) grew higher (37.7% +/- 7.5% and 35.1% +/- 9.0%, respectively) as the sevoflurane concentration increased to 1.4%. However, the first peak leveled off whereas the second tended to decrease slightly with further increases in sevoflurane concentration. The BIS value decreased as the sevoflurane concentration increased and leveled off at 1.4% and higher concentrations of sevoflurane. The SEF 95 also decreased as the sevoflurane concentration increased up to 2.3%. Thus the distribution pattern of the two bicoherence peaks is likely to be better than BIS of the anesthetic effect of sevoflurane during surgery.

Adult↗
PubMed2006

[Anesthetic management with propofol for pheochromocytoma resection under monitoring of bispectral index and blood volume].

In two patients, pheochromocytoma resection was performed under propofol/fentanyl anesthesia, while bispectral index (BIS) monitoring and blood volume measurement using pulse spectrophotometry were done. In one patient (Case 2), arterial blood concentrations of propofol were measured by high performance liquid chromatography (HPLC), and compared with those of the estimated blood concentrations. Continuous infusion of nitroprusside and bolus infusion of nicardipine and/or diltiazem were used when hypertension and tachycardia occurred. After resection of the tumor, propofol dosage was reduced keeping the BIS values around 60. In both patients, blood volume was maintained higher than normal value (Case 1: 79-101, and Case 2: 91-112 ml x kg(-1)) during operation. After tumor resection, the blood pressure was maintained well without rapid infusion of fluid or vasopressor. Arterial blood concentration of propofol was lower than the estimated blood concentration during operation in high blood volume case (Case 2). BIS monitoring and blood volume measurement are useful for adjustment of propofol dosage and for avoidance of hypotension after pheochromocytoma resection.

Adrenal Gland Neoplasms↗
PubMed2006

[Auditory evoked potentials].

Auditory evoked potentials (AEPs) are an electrical manifestation of the brain response to an auditory stimulus. The waveform represents the passage of electrical activity provoked by auditory stimuli from the cochlea to cortex. The waves represented by I-VII are generated mainly in the brainstem. These waves are called the brain stem auditory evoked potentials (BAEPs) or the auditory brain stem response (ABR). The middle latency AEPs (MLAEP) are generated from the medial geniculate and primary auditory cortex. The long latency AEPs (LLAEP) are generated from the frontal cortex and association areas. The BAEPs appear to be an exquisitely sensitive monitor for pathological events during surgery. Anesthetics and mild hypothermia have minimum effect, if any, on the BAEPs. The BAEPs are useful during the microvascular decompression of the fifth or seventh cranial nerve, resection of acoustic neuroma and posterior fossa operations. Because the auditory pathway occupies a small area in the brainstem, combined use of other evoked potentials such as short latency sensory evoked potentials is recommended. The MLAEPs are most promising evoked responses for monitoring awareness or depth of anesthesia. When the concentration of anesthetics is increased, the amplitudes of the MLAEP's peaks are decreased and their latencies are elongated. Commercially developed A-line AEP monitor or aepEX can extract the AEPs waveform in a short period and automatically analyze the changes in the MLAEPs. These AEP based monitors may be superior to bispectral index (BIS) in detecting the transition from unconsciousness to consciousness.

Anesthesia↗
PubMed2005

Utility of diffusion-weighted images using fast asymmetric spin-echo sequences for detection of abscess formation in the head and neck region.

OBJECTIVE: The objective of this study was to evaluate the utility of new diffusion-weighted magnetic resonance images (DWI) using fast asymmetric spin-echo (FASE) sequences for the detection of abscess formation in patients with phlegmon in the oral and maxillofacial regions. METHODS: We compared diffusion-weighted images using FASE sequences with those using the gradient-echo type of echo-planar images (EPI) in 10 control volunteers and 10 patients with phlegmon in the oral and maxillofacial regions. RESULTS: Many kinds of tissues in the oral and maxillofacial regions were relatively well visualized in all subjects on FASE-DWI, but not well on EPI-DWI. Apparent diffusion coefficients calculated from FASE sequences in abscess areas of patients with phlegmon were significantly lower than those in abscess-free areas; however, apparent diffusion coefficients calculated from EPI were not significantly different due to prominent distortion in small sample size study. CONCLUSIONS: We could accurately recognize the presence of abscess formation within inflammatory tissue in 5 patients with phlegmon using FASE-DWI. As an additional magnetic resonance examination, FASE-DWI might be useful in the detection of abscess formation in the oral and maxillofacial regions.

Abscess↗
PubMed2005

Relationship of the unstimulated whole saliva flow rate and salivary gland size estimated by magnetic resonance image in healthy young humans.

OBJECTIVE: The aim of this study was to examine the relationships between gland sizes and the flow rate and composition of the unstimulated whole saliva in humans. DESIGN: In 28 healthy young adults, the sizes of the three major salivary glands were estimated by use of a magnetic resonance (MR) imaging technique. Unstimulated whole saliva was collected for 5 min by the spitting method, and the flow rate and the concentrations of total protein, Na(+) and K(+) and pH were measured. RESULTS: The estimated sizes of the parotid and submandibular glands showed a significant positive correlation with the flow rate and the secretion rate of total protein in the unstimulated whole saliva, but that of the sublingual glands did not. Concerning the concentrations of Na(+) and K(+) and pH, there were no correlations with the salivary gland sizes. CONCLUSIONS: The results suggest that the larger the sizes of the parotid and submandibular glands, the faster the fluid flow and protein secretion rates in unstimulated whole saliva.

Adult↗
PubMed2005

Target-controlled infusion of propofol for a patient with myotonic dystrophy.

We present a patient with myotonic dystrophy (MD) who was anesthetized with propofol using a target-controlled technique for electrophysiologic examination and cardiac catheter ablation. The patient became apneic unexpectedly at the same time when he fell asleep, with effect-site propofol concentration of 1.6 microg ml(-1). We had to insert a laryngeal mask airway (LMA), and mechanical ventilation was performed. The patient opened his eyes on verbal command at an effect-site concentration of 1.2 microg ml(-1) after the procedure. This concentration (1.2 microg ml(-1)) was slightly lower than our institutional average for adult male patients (1.5 +/- 0.2 microg ml(-1)). However, the time from the end of anesthesia to the patient's awakening was about 10 min. We considered that emergence from anesthesia was not delayed in this case. Careful titration of propofol by target-controlled infusion (TCI) enabled to evaluate the patient's sensitivity to propofol. We conclude that TCI of propofol was a useful anesthetic technique in the MD patient. Respiratory depression might occur in MD patients at low propofol concentrations. Precise control and titration over target propofol concentration is important in anesthetic management for MD patients.

Adult↗
PubMed2005

Evaluation of the relationship between periapical lesions/sclerotic bone and general bone density as a possible gauge of general health among 80-year-olds.

OBJECTIVES: To evaluate the incidence among 80-year-olds of periapical lesions as detected on panoramic radiographs and to determine the relationship between sclerotic bone around the periapical lesions to heel bone density, body height, and hand-grip strength. STUDY DESIGN: Six hundred fifty-nine panoramic radiographs (262 males, 397 females), obtained from 80-year-old residents of Fukuoka Prefecture, Japan, were used for evaluation of periapical lesions. These findings were correlated with physical examination results to determine the relationship to general health. RESULTS: Of 659 panoramic radiographs, 31 (5%) were noted to have periapical lesions. Average size of the 31 periapical lesions was 6.1 +/- 2.2 mm. Of the 31 periapical lesions, 21 (68%) were accompanied by linear or diffuse types of sclerotic bone. Of the 21 sclerotic bones, 10 (48%) were of a linear type of sclerotic bone and 11 (52%) of a diffuse type of sclerotic bone. Of the 11 diffuse types of sclerotic bone, 10 (91%) were in the mandible and 1 (9%) in the maxilla. Periapical lesions in the mandible were more frequently accompanied by a diffuse type of sclerotic bone than those in the maxilla (P < .01). The hand-grip strength of those having periapical lesions, accompanied by a diffuse type of sclerotic bone, was stronger than those having no periapical lesions (P < .01) and those accompanied by a linear type of sclerotic bone (P < .03). However, there was no relationship between presence of sclerotic bone and heel bone density or body height. CONCLUSIONS: Periapical lesions accompanied by a diffuse type of sclerotic bone were more frequently seen in the mandible of 80-year-olds. To evaluate the clinical significance of sclerotic bone around periapical lesions in 80-year-olds, further study to evaluate the significance of endodontic treatment needs to be done.

Aged↗
PubMed2005

The functional evaluation of salivary glands using dynamic MR sialography following citric acid stimulation: a preliminary study.

OBJECTIVE: We introduce a new technique for the functional evaluation of the salivary glands using continuous magnetic resonance (MR) sialography before and after citric acid stimulation. METHODS: In 10 volunteers, the time-dependent changes in the maximum area of the detectable parotid gland ducts on MR sialographic images taken every 30 seconds before and after citric acid stimulation were analyzed. The time period to the occurrence of the maximum duct area poststimulation was noted, and then the time for the area to return to its 50% value pre-citric acid stimulation was also observed. This new technique was clinically applied in 1 patient with an excessive supply impression of saliva and in 1 patient with a short supply impression with saliva. RESULTS: In all volunteers after citric acid stimulation, the maximum area of the detectable salivary gland ducts first increased and then decreased. A strong relationship was found between the maximum area of the detectable salivary gland ducts before citric acid stimulation and total saliva volume (Pearson r = 0.672, P = .031). Compared with all the volunteers, the ratio of change in the detectable ducts was the highest in the patient with an excessive supply impression of saliva, but lowest in the patient with a short supply impression with saliva. CONCLUSIONS: This initial study suggests that dynamic MR sialography allows for functional and morphological evaluation of the salivary glands. This technique appears to have many possible applications and further investigation in this field is necessary.

Adult↗
PubMed2005

Utility of magnetic resonance cisternography using three-dimensional fast asymmetric spin-echo sequences with multiplanar reconstruction: the evaluation of sites of neurovascular compression of the trigeminal nerve.

OBJECTIVE: To evaluate the utility of magnetic resonance (MR) cisternography using 3-dimensional (3D) fast asymmetric spin-echo (FASE) sequences with multiplanar reconstruction (MPR) for detection of the sites of neurovascular compression (NVC) in patients with trigeminal neuralgia. STUDY DESIGN: Both MR cisternography with 3D-FASE sequences and MR angiography (MRA) were performed on 150 patients with clinical signs and symptoms that suggested trigeminal neuralgia. Results from the original MR cisternography with 3D-FASE sequences, the original MRA, and 4 reformatted images were used for interpretation. Images with inversion between black and white were used from the MR cisternography with 3D-FASE sequences to evaluate NVC. A diagnosis of NVC was made from the presence of vascular contact with the trigeminal nerve at the root entry zone (REZ) and the nature of the involved vessels. For the patients with NVC detectable on 3D-FASE or MRA images, the relationship between the clinically manifested regions and the NVC sites was also evaluated. RESULTS: Of the 150 patients evaluated, 89 were deemed to have NVC. Of these 89 patients, 3 underwent surgery that identified the artery that was involved with the trigeminal nerve. The correlation between the clinically manifested regions and the NVC sites was significantly detectable using both 3D-FASE images and MRA in 89 patients with detectable NVC. The correlation coefficient using 3D-FASE imaging was a little higher than that using MRA. Of the 61 patients deemed not to have NVC, 6 were found to have brain tumors that invaded the root entry zone of the trigeminal nerve. However, the remaining 55 patients had no identifiable cause for trigeminal neuralgia. NVC was found in the asymptomatic side in 27 (18%) of the 150 patients with trigeminal neuralgia using MR cisternography with 3D-FASE sequences. CONCLUSIONS: The technique of MR cisternography using 3D-FASE sequences with MPR is more accurate and useful than MRA for detection of the site of NVC in patients with trigeminal neuralgia. Patients with trigeminal neuralgia should be further examined using MR imaging to rule out a brain tumor. Radiologists should understand that a few subjects with no symptoms could show NVC with MR cisternography.

Adolescent↗
PubMed2005

Three-dimensional identification of hemangiomas and feeding arteries in the head and neck region using combined phase-contrast MR angiography and fast asymmetric spin-echo sequences.

OBJECTIVE: To evaluate a proposed technique for the 3-dimensional (3D) detection of hemangiomas, including vascular malformation and their feeding arteries, in the head and neck. The new technique combines phase-contrast magnetic resonance angiography (PCMRA) without contrast medium and 3D fast asymmetric spin-echo (FASE) sequences. METHODS: The technique was applied to 3 patients having hemangiomas in the head and neck region. In 1 patient the image obtained with the proposed technique was compared to that obtained by standard contrast angiography. RESULTS: In all 3 patients, the 3D presence of the hemangiomas and the feeding arteries were well defined in images created by the proposed technique. Additionally, the characterization of the hemangioma's 3D structure and distribution of the feeding arteries coincided with those observed using contrast angiography in the case for which contrast angiography was also performed. CONCLUSIONS: Preliminary experience shows that the proposed technique combining 3D-FASE and 3D-PCMRA is useful to visualize both the 3D structure of hemangiomas and to identify the 3D distribution of the feeding arteries without using contrast medium.

Adult↗
PubMed2005

The detection of cerebral hypoperfusion with bispectral index monitoring during general anesthesia.

We describe a patient in whom the bispectral index (BIS) decreased to 0 during surgery. A 42-yr-old man with chronic renal failure was scheduled to undergo construction of an arteriovenous shunt. He had a history of acute cerebral hemorrhage. An intracranial hematoma had been removed a month earlier with almost complete neurological recovery. He had uncontrolled hypertension. His systolic blood pressure was 180 mm Hg before anesthesia induction. Anesthesia was induced with 100 mg of propofol and 3% sevoflurane. After laryngeal mask insertion, anesthesia was maintained with nitrous oxide 60% in oxygen and sevoflurane. BIS decreased to near 0 on 2 occasions: after anesthesia induction and shortly after the start of the surgery. His systolic blood pressure decreased to 110 mm Hg and BIS increased when his blood pressure was increased to 130-140 mm Hg. The decrease in BIS was suspected to be the result of decreased cerebral blood flow. The systolic blood pressure of 110 mm Hg (mean blood pressure, 80 mm Hg) was probably less than the lower limit of autoregulation. Although BIS has some limitations as a cerebral monitor, it was useful for detecting possible cerebral hypoperfusion in this case.

Adult↗
PubMed2005

Changes in the bispectral index during intraabdominal irrigation in patients anesthetized with nitrous oxide and sevoflurane.

Surgical stimulation typically results in an activation of electroencephalographic activity. In some instances, painful stimulation in the presence of inadequate anesthesia results in a suppression of the electroencephalogram. This phenomenon has been referred to as a "paradoxical arousal." In our daily practice, we have noted a marked decrease in the bispectral index (BIS) with large delta waves during abdominal surgery when the abdominal cavity was irrigated with normal saline. In the present study, we sought to evaluate changes in BIS during intraabdominal irrigation. Eighteen ASA physical status I-II patients scheduled for elective abdominal surgery were enrolled in the study and allocated randomly to the control group (group C) or the fentanyl group (group F). Anesthesia was induced with 3 mg/kg of thiopental and was maintained with sevoflurane and 50% nitrous oxide. BIS, 95% spectral edge frequency (SEF95), and burst-suppression ratio were recorded using a BIS monitor. Near the end of the procedure, but before irrigation of the abdominal cavity, 1.5 microg/kg fentanyl was given IV to group F. There was no significant change in BIS or SEF95 in group F patients during subsequent irrigation of the abdominal cavity. In contrast, BIS and SEF95 decreased significantly after start of irrigation in group C patients. These data show that the stimulation occurring during intraabdominal irrigation might cause a paradoxical arousal response, as evidenced by a decrease in processed electroencephalographic parameters. Pretreatment with fentanyl suppressed these changes. Anesthesiologists should be aware of this paradoxical arousal response to avoid an inappropriate decrease in the anesthetic concentration in such situations.

Adult↗
PubMed2005

[Anesthetic management of a patient undergoing PTA stent placement for right common carotid artery stenosis].

A 60-year-old man underwent percutaneous transluminal angioplasty (PTA) stent replacement of the right common carotid artery. Preoperative angiogram revealed bilateral vertebral artery occlusion and 50% stenosis in contralateral internal carotid artery. Anesthesia was induced and maintained with fentanyl and propofol by TCI. rSO2, BIS and EEG were monitored. Moderate hypothermia (33-35 degrees C) was induced by concomitant use of milrinone. Edaravone, a novel free radical scavenger, and Sendai cocktail were administered before interruption of carotid flow. During 5 minutes of test occlusion by balloon, right rSO2 decreased from 61% to 49% and EEG showed slow waves with decreased amplitude. Therefore we decided to perform PTA and stenting separately. Right rSO2 decreased from 62% to 48% during PTA (6 min occlusion), while rSO2 decreased from 66% to 50% during stenting (7.5 min occlusion). EEG also showed the similar changes as observed during test occlusion. After the procedures, rSO2 and EEG recovered in a short time. Postoperative angiogram showed an improvement of carotid artery stenosis and intracranial vessels showed no branch occlusion. Patient was maintained hypothermic (35 degrees C) for 2 days after surgery. He recovered without additional neurological complications. We found that rSO2 was a useful, real-time and non-invasive method for evaluation of cerebral ischemia in our patient.

Angioplasty, Balloon↗
PubMed2004

Clinical application of magnetic resonance sialographic 3-dimensional reconstruction imaging and magnetic resonance virtual endoscopy for salivary gland duct analysis.

PURPOSE: In a previous study, we showed that the new and fast sequence 3-dimensional (3D)-fast asymmetric spin-echo sequencing could be applied in magnetic resonance (MR) sialographic 3D reconstruction imaging of the parotid gland ducts and in producing virtual endoscopic views of the parotid gland with MR data. MATERIALS AND METHODS: In the present study, we examined the clinical application of these MR sialographic 3D reconstruction imaging and virtual endoscopy of the salivary gland ducts using MR data sets with 3D-fast asymmetric spin-echo sequencing. RESULTS: The MR sialographic 3D reconstruction images showed a complete view in the branch paths from all angles, and the MR virtual endoscopic views showed conditions in the endoluminal tracts of the large branches in 20 patients with salivary gland duct abnormalities, including Sjögren syndrome, cyst, tumor, sialadenitis, and salivary calculi. CONCLUSION: The clinical use of MR sialographic 3D reconstruction imaging and MR virtual endoscopy for salivary gland ducts may enhance understanding of the 3D relationship between the ducts and the surrounding tissue, as well as the endoluminal circumstance within ducts. Possible future applications abound, and further investigation in this field is expected.

Adolescent↗
PubMed2004

Inflammatory paradental cyst (IPC) in the mandibular premolar region in children.

OBJECTIVES: We investigated the occurrence of inflammatory paradental cysts (IPC) in the mandibular premolar, and demonstrated the points of difference with regard to diagnostic features between IPC and dentigerous cysts (DC). MATERIAL AND METHODS: We analyzed the radiographs and histology of 60 cases with a cystic lesion associated with inflammation in the mandibular premolar region based on diagnostic criteria as IPC. RESULTS: In 4 out of 60 cases, we diagnosed the 4 cysts as IPCs in the mandibular premolar region, and recognized that one form of IPC was similar to a mandibular infected buccal cyst. The other 56 non-IPC cases were diagnosed as DC. On the IPCs, the permanent tooth normally erupted in all 4 cases after treatment, but in one case, the IPC recurred. CONCLUSIONS: The present investigation suggested that we might have misdiagnosed IPCs in the mandibular premolar region as DC to date. It is important to consider the differences between IPC and DC with regard to the causes of recurrence during treatment of IPC.

Adolescent↗