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Biomedical subjects

Y Handa

Publications and source records attributed to Y Handa.

At least 73 records · Page 4Linked to original sources
PubMed1995

Expression of intercellular adhesion molecule 1 (ICAM-1) on the cerebral artery following subarachnoid haemorrhage in rats.

In order to study how immune-inflammatory responses are involved in the pathogenesis of cerebral vasospasm after subarachnoid haemorrhage (SAH), the kinetics of expression of the intercellular adhesion molecule 1 (ICAM-1), a ligand for the leucocyte adhesion receptor, were studied on the cerebral arteries following SAH in rats. The SAH was induced by intracisternal injection of arterial blood. The rats were sacrificed at specified times: immediately after induction of SAH to seven days after SAH. Cryostat sections of the basilar artery (BA) were prepared and incubated with anti-rat ICAM-1 antibody. Morphometric analysis of the BA revealed a significant narrowing of the luminal diameter on Day 2 following SAH. While in the non-treated normal animals, no nor only weak expression of ICAM-1 was observed on the endothelial layer of the BA, there was greater expression of ICAM-1 on the endothelial layer of the BA in SAH rats, and the expression was observed also in the medial layer of the artery from Day 2 to Day 5 following SAH. The present results indicate that SAH really causes responses in the cellular immunity not only in the endothelial layer, but also in the medial layer of the artery as a target of immune damage, which is presumed to be one of the important steps in the development of cerebral vasospasm.

Animals↗
PubMed1995

The influence of total body hyperthermia on brain haemodynamics and blood-brain barrier in dogs.

This study was designed to examine the influence of total body hyperthermia (TBHT) using an extracorporeal circuit with a heat exchanger on the cerebral blood flow (CBF), intracranial pressure (ICP), brain tissue pH, cerebral autoregulation and blood-brain barrier (BBB) permeability in dogs. The rectal temperature of the dow was raised to 41.5 degrees C, maintained at 41.5-42.0 degrees C for 2 hours (HT period) and then reduced to normothermia by cooling. Regional CBF was measured by the hydrogen clearance method before heating, during the HT period and after cooling. ICP and brain tissue pH were monitored during the TBHT treatment. Autoregulation of the CBF during the HT period was assessed by measuring the regional CBF and the ICP in a state of induced hypo- or hypertension. The influence of TBHT on BBB permeability was examined using an immunohistochemical technique. The regional CBF increased from 38.1 +/- 6.5 (mean +/- SD) to 49.1 +/- 9.8 ml/100 g/min and the ICP from 10.3 +/- 4.2 to 16.8 +/- 3.4 mmHg when TBHT was raised. These returned to normal values after cooling. The regional CBF and the ICP changed in parallel with drug-induced changes of mean arterial blood pressure during the HT period. These changes suggest that autoregulation of the CBF is paralysed during the HT period. Brain tissue pH decreased rapidly when the rectal temperature exceeded 41.0 degrees C. The pH was 7.18 +/- 0.05 during the HT period and was relatively stable. The pH returned to a normal value after cooling. Immunopositive stain for albumin was not observed in heated brain tissue except for the normally leaky pineal gland and the choroid plexus, indicating preservation of BBB during TBHT. These results suggest that brain oedema may occur easily due to paralysed cerebral autoregulation when the arterial blood pressure fluctuates excessively, so arterial blood pressure must be controlled strictly during TBHT.

Acid-Base Equilibrium↗
PubMed1995

Effect of mannitol on focal cerebral ischemia evaluated by somatosensory-evoked potentials and magnetic resonance imaging.

BACKGROUND: Mannitol has been used in routine neurosurgical practice for the control of increased intracranial pressure. The effect of mannitol on focal cerebral ischemia was evaluated by somatosensory-evoked potentials (SEP) and magnetic resonance imaging (MRI). METHODS: The left middle cerebral artery (MCA) was exposed via the superomedial transorbital approach and occluded proximal to the origin of the perforating arteries. Ten cats received mannitol (0.5 g/kg IV) immediately, 6, 12, and 18 hours after MCA occlusion. The other 10 cats received saline solution and served as control. The animals were initially prepared to measure SEP before and 15, 30, and 60 minutes after MCA occlusion. Following SEP measurement, all cats were prepared for MRI. Sequential MRI of both intravoxel incoherent motion (IVIM) and T2-weighted spin echo techniques were obtained at 2, 4, 6, and 24 hours after MCA occlusion. The animals were sacrificed after the last MRIs for histologic study. RESULTS: The SEP amplitude decreased to about 10% at 15 minutes after MCA occlusion and then gradually recovered to 38% at 60 minutes in the mannitol group, and 21% in the control group. In MRI study, IVIM imaging demonstrated ischemic cerebral injury as a sharply demarcated area at 2 hours after MCA occlusion, while T-2 weighted imaging failed to show clear evidence of injury until 2-6 hours. High-signal intensity areas on both IVIM and T2-weighted images were smaller in the mannitol group than those in the control group. Histologic study demonstrated that infarction size was 36.9% +/- 7.7% of the left hemisphere in the mannitol group and 57.3% +/- 5.3% in the control group (p < 0.05). CONCLUSIONS: Mannitol is effective for acute cerebral ischemia, and SEP and MRI are useful for monitoring it.

Animals↗
PubMed1995

Mutagenicity of soy sauce treated with nitrite in the presence of ethanol or alcoholic beverages.

The mutagenicity induced by soy sauce after reaction with 50 mM nitrite at pH 3, 37 degrees C, for 60 min in the presence of 1.25-10% ethanol was reduced in proportion to the ethanol concentration. The mutagenicity of soy sauce treated with nitrite was also reduced in the presence of commercial alcoholic beverages, Japanese sake, wine, 'shochu', whiskey and brandy, but not beer, in proportion to the concentration. The mutagenicity of nitrite-treated tyramine, which is a major precursor of a mutagen in soy sauce treated with nitrite, was strongly reduced in the presence of ethanol, n-propanol or isopropanol and more strongly reduced in the presence of methanol, but was increased twofold in the presence of the sugars glucose or sucrose. The reduction of the mutagenicity of nitrite-treated tyramine required simultaneous treatment of tyramine with ethanol and nitrite. The mutagenicity of tyramine treated with nitrite was clearly reduced in the presence of shochu and whiskey, similarly to ethanol. Analysis by high-performance liquid chromatography revealed that the reduction of the mutagenicity of nitrite-treated tyramine in the presence of ethanol resulted from the reduced production of mutagenic 3-diazotyramine from tyramine.

1-Propanol↗
PubMed1995

Prevalence study of oral mucosal lesions in a selected Cambodian population.

The aim of this study was to investigate the epidemiology of oral mucosal lesions in a selected Cambodian population to obtain pilot data useful in planning an oral health data base for the country. Due to unstable conditions in Cambodia, the validity of population data related to present census information is highly questionable. Therefore, prior to this investigation a census registration was carried out using local health workers as registrars in nine villages of a commune. In the period July 4-31, 1991, a total of 1319 individuals (953 women, 366 men, 15-99 yr) were examined by one oral surgeon in the nine villages of Kok Trop Commune, Kandal Stung District, southwest of the capital Phnom Penh. Clinical diagnoses were based on WHO criteria. Information on smoking habits, betel nut chewing habits, and alcohol use was collected by 4 Khmer dental personnel. In total, 71 lesions were recorded in 64 (4.9%) individuals. Leukoplakia was found in 1.1%, lichen lesions in 1.8%, candidosis in 1.4%, submucous fibrosis in 0.2%, cancer in 0.1% and other diagnoses in 0.8%. The prevalence of leukoplakia was 2.2% and 0.6% among men and women respectively, a statistically significant difference (P < 0.05). There were significantly more smokers (P < 0.01) among subjects with leukoplakia (64.3%) than among those without this lesion (28.6%). All subjects with lichen lesions were women. The age-adjusted relative risk for developing lichen among betel nut chewers as compared to non-chewers was 3.3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Intracranial hemorrhage due to long-term anticoagulant therapy in patients with prosthetic heart valves--four case reports.

Four patients with prosthetic heart valves suffered intracranial hemorrhage (cerebral hemorrhage in one patient, cerebellar hemorrhage in one, and chronic subdural hematoma in two) during long-term oral anticoagulant drug therapy (warfarin). In all patients, warfarin was discontinued and its effect neutralized by vitamin K, then surgery was performed after the thrombotest value exceeded 50%. No uncontrollable bleeding occurred at surgery. Warfarin was discontinued until 3-7 days postoperatively. Intravenous heparin administration was used to prevent embolic complications and the dose was modified based on the activated clotting time measured at the bedside. One patient, who could not receive heparin administration because of massive bleeding, developed myocardial infarction due to coronary artery thromboembolism 2 days after operation and died 4 days later. The other patients received heparin administration and were alive and well at the most recent follow-up examinations. Heparin administration monitored by activated clotting time is a useful method to prevent embolic and bleeding complications in the surgical treatment of intracranial hemorrhage in patients with prosthetic heart valves receiving long-term anticoagulant therapy.

Cerebral Hemorrhage↗
PubMed1995

Surgical treatment for ossification of the posterior longitudinal ligament of the cervical spine.

The results of surgical management of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine consisting of either anterior or posterior surgical decompression of the spinal cord and/or nerve roots were evaluated in 75 patients. The OPLL was continuous (COPLL) in 37 patients, segmental (SOPLL) in 29, mixed COPLL and SOPLL (MOPLL) in five, and circumscribed disk type (DOPLL) in four. Fourteen of the patients with COPLL, 27 with SOPLL, three with MOPLL, and all four with DOPLL were treated via the anterior approach with vertebrectomy and discectomy with anterior fusion. The remaining patients were treated by posterior laminoplasty or laminectomy. The overall mean improvement in the neurosurgical cervical spine scale (NCSS) score after surgery was 78.0% in those treated with anterior decompression and 46.1% in those treated with posterior decompression. The NCSS score in the latter group decreased during the follow-up period, from 10.4 to 9.7 points, whereas that in the anterior decompression group increased, from 12.9 to 13.0.

Adult↗
PubMed1995

Control of thumb movements: EMG analysis of the thumb and its application to functional electrical stimulation for a paralyzed hand.

This paper describes the control of thumb movements by functional electrical stimulation (FES). In order to determine stimulation data of thumb muscles, activities of nine thumb muscles and the palmaris longus were analyzed in normal subjects by averaging their EMGs. In this analysis, it was found that well coordinated contractions of these thumb muscles were required for finer movements and precise positioning of the thumb. Based upon this analysis, several standard stimulation data for the thumb muscles were programmed and stored into a computer-controlled FES system. Input of the threshold and maximum stimulating voltages for individual thumb muscles of normal subjects to the system enabled automatic creation of stimulation data for each subject. The thumb movements of the normal subjects induced by these data were very smooth and their trajectories were reproducible. In addition, precise thumb positioning and joint stability were easily obtained. These standard stimulation data for the thumb muscles were also applied to FES control of a C4 quadriplegic. The controllability of the thumb movements was improved and the reliability of hand tasks achieved by FES was increased.

Adult↗
PubMed1994

Effect of mannitol on focal cerebral ischemia evaluated by magnetic resonance imaging.

We have evaluated the effect of mannitol on focal cerebral ischemia using T2-weighted magnetic resonance (MR) imaging and intravoxel incoherent motion (IVIM) MR imaging. The left middle cerebral artery (MCA) was exposed via the transorbital approach in 20 adult cats and occluded just proximal to the origin of the perforating arteries. Seven cats in treatment group received mannitol (0.5 g/kg i.v.) at 0, 6, 12 and 18 hours after MCA occlusion. The other 13 cats received saline and served as controls. Sequential MR coronal images were obtained at 2, 4, 6, and 24 hours after MCA occlusion using a GE Signa (1.5 tesla) system. IVIM MR imaging demonstrated ischemic cerebral injury as a sharply demarcated area at 2 hours after MCA occlusion in control group, while T2-weighted MR imaging failed to show clear evidence of the injury until 2-6 hours. At 24 hours after MCA occlusion, the infarcted area in the mannitol treatment group was 36.9 +/- 7.7% (S.E.M) of the left hemisphere, as compared to 57.3 +/- 5.3% in control group (p < 0.05). Mannitol has beneficial effect on ischemic injury.

Animals↗
PubMed1994

Diagnostic accuracy of the ultrathin arthroscope for temporomandibular joint osteoarthrosis: comparison of arthroscopic and histologic findings in a sheep model.

The diagnostic accuracy of the ultrathin arthroscope was evaluated by examination of the superior joint space of the left temporomandibular joint in 20 sheep. At the time of induction of osteoarthrosis all joints were found to be normal. Six months later the arthroscopic examination was repeated and the results compared with the histologic examination. Similar findings were seen in 11 joints (55%), with arthroscopic overdiagnosis in two (10%) and underdiagnosis in seven (35%). Eight of 16 (50%) disc perforations were found. It was concluded that underdiagnosis occurred because the whole joint space cannot be examined arthroscopically and fibrillated tissue masks bone exposure.

Animals↗
PubMed1994

The effect of occlusal loss on normal and pathological temporomandibular joints: an animal study.

The effect of unilateral posterior malocclusion on temporomandibular joint intra-articular pathology was studied in sheep. In Group I, osteoarthritic changes were induced in the left temporomandibular joint by gentle scraping of the articular surface (Ishimaru and Goss, 1992). Group II had the same procedures as Group I, with concurrent extraction of all the left maxillary posterior teeth. Group III had a different osteoarthritic precondition in the left temporomandibular joint, allowing synovial fluid to contact the condylar marrow (Ishimaru et al., 1992). Group IV had the same procedure as Group III, with concurrent extraction of all the left maxillary posterior teeth. Group V had unilateral maxillary molar teeth extraction in the left side. At 3 months, the animals were sacrificed and the joints examined histologically. There were no significant differences between normal control joints and those with unilateral tooth extraction (Group V). Similarly the degree of osteoarthritic change was the same between Groups I and II. Significant differences (p < 0.05) were seen between Groups III and IV with tooth extraction increasing the osteoarthritic effects. Hence it was concluded that in sheep, malocclusion had no effect on the normal temporomandibular joint and on one type of experimental osteoarthritis, but accelerated osteoarthritic change in another model.

Alveolectomy↗
PubMed1994

Electrophysiological studies of the biceps brachii activities in supination and flexion of the elbow joint.

Activities of the biceps brachii (long head: BiL, short head: BiS) on the elbow joint were studied using an electrical neuromuscular stimulation (ENS) and an electromyography (EMG). In ENS study, ENS to BiL or BiS was performed in seven volunteers. Before ENS, the volunteer relaxed the upper extremity on a table with the elbow extended and the forearm pronated. Then ENS-induced movements of the upper extremity were examined. Movements of elbow flexion and forearm supination were induced simultaneously by ENS to BiS in all volunteer and by ENS to BiL in six volunteers. ENS to BiL of one volunteer resulted in only elbow flexion. In EMG study, averaged EMGs of BiL and BiS during a to-and-fro motion from prone to supine of the forearm with holding a load were analyzed in eight volunteers. The volunteer acted the movements with keeping the elbow joint in different angles. Although an increase and a decrease of EMG activities in BiL and BiS were observed accompanied by the degree of forearm supination, patterns of changes in quantities of EMG activities to changing elbow angles varied from individual to individual. These findings seem to indicate that each human subject has an individual use of the biceps brachii for supination movements, while the action of the muscle on the elbow joint is similar among the subjects.

Adult↗
PubMed1994

Functional electrical stimulation (FES) to the biceps brachii for controlling forearm supination in the paralyzed upper extremity.

Control of forearm supination using the functional electrical stimulation (FES) to the biceps brachii was studied in a C4 quadriplegic patient. As a result of FES to the biceps brachii, and the other elbow flexors and extensors, supination was induced in maintenance of the elbow in the maximum flexion and extension, respectively. Although a range of the movements was still small and limited, these findings indicated a possibility of FES to the biceps brachii for controlling supination in paralyzed upper extremities.

Adult↗
PubMed1994

Study on the elbow movement produced by functional electrical stimulation (FES).

Functional electrical stimulation (FES)-induced movements of the upper extremity using the electromyography (EMG)-based stimulation data, which were created on the basis of EMG analysis of elbow flexion and extension in a normal human subject, were examined. As a result of the FES to the elbow flexors and extensors in another normal subject, smooth and reproducible elbow flexion and extension were controlled. This result seems to indicate not only an advantage of EMG-based stimulation data in the FES but also a great potential of FES as a new technique for the functional anatomy of the human extremities.

Elbow Joint↗
PubMed1994

[Strategies of general anesthesia for cleft palate surgery in Cambodia].

Hare lip and cleft palate surgery team activities in Cambodia were launched in 1989 by a non-governmental Japanese organization, Operations Unies. The objectives of the project are to provide appropriate surgical treatment and safe general anesthesia for local patients and also to conduct technology transfer of general anesthesia and surgery to the local medical staffs. From June 1991 to January 1993, a surgery/anesthesia team was dispatched 4 times and a total of 130 patients received surgical treatments under general anesthesia. Anesthesia techniques employed included total intravenous anesthesia in 70 patients (54%) and intravenous anesthesia with 0.3-0.7% of halothane in 60 patients (46%). There were no major complications, such as airway obstruction and apnea, in the recovery room and in the ward. The reasons why we chose intravenous agents are difficulty in obtaining inhaled agents in Cambodia and lack of scavenging system in a operating room. Although halothane anesthesia with spontaneous breathing has been recommended in developing countries, total intravenous anesthesia could be one of the applicable techniques in these countries. In Cambodia, shortage of medical doctors and the absence of anesthesiologist constitute a major barrier to technology transfer in clinical anesthesia.

Anesthesia, General↗
PubMed1994

Electrical pelvic floor stimulation by percutaneous implantable electrode.

OBJECTIVE: To describe a clinical experience of chronic pelvic floor stimulation using a percutaneous implantable electrode for the treatment of urinary incontinence. PATIENTS AND METHODS: Pelvic floor stimulation using a percutaneous procedure was performed in 10 patients who were suffering from urinary incontinence due to overactive detrusor function. After implantation of the electrode chronic stimulation was instituted with a portable external electrical stimulator. RESULTS: Four to 16 weeks of maximal electrical stimulation improved urinary incontinence in eight of 10 patients. In two of these eight patients incontinence disappeared as measured subjectively. Urodynamic investigations demonstrated a significantly increased volume at the first unstable contraction (P < 0.01) in all patients. One of 30 electrodes migrated during the follow-up period. CONCLUSION: Inhibition of detrusor overactivity was obtained using this procedure. Response appeared to be constant during chronic stimulation. This procedure appears to provide stable and reliable stimulation for chronic treatment of urinary incontinence and may be an alternative to electrical pelvic floor stimulation.

Adult↗