Biomedical subjects

H Muratani

Publications and source records attributed to H Muratani.

At least 19 recordsLinked to original sources

PubMed2000

Hemorrhagic subdural effusion complicating an endoscopic III ventriculostomy.

Subdural effusion, a common postoperative complication of extracranial shunting for hydrocephalus, is usually caused by excessive drainage of cerebrospinal fluid. Subdural effusion is thought to occur less frequently after a neuroendoscopic III ventriculostomy, and no reported cases have been symptomatic. We encountered a symptomatic subdural effusion with a component of hemorrhage 5 days after the latter procedure was performed to treat massive hydrocephalus in a 2-year-old boy.

Brain↗

PubMed2000

Spinal intradural perimedullary arteriovenous fistula with varix in infant.

A rare occurrence of type IV spinal arteriovenous malformation (intradural perimedullary arteriovenous fistula) is described in an 18-month-old boy initially misdiagnosed with Guillain-Barré syndrome. An intramedullary mixed-intensity mass lesion at Th1 was demonstrated by magnetic resonance imaging together with flow voids over the dorsal aspect of the swollen spinal cord. Angiography demonstrated an intradural perimedullary arteriovenous fistula including an intraparenchymal vascular pocket. After partial embolisation of the posterior spinal arteries through the left intercostal-radicular artery, the arteriovenous fistula was removed completely together with an organised haematoma. The fistula directly opened into a vascular pocket, which was confirmed pathologically to be a varix. The postoperative course was uneventful, and the patient resumed ambulation within 4 months. The case, subclassifiable as a type IVb spinal perimedullary AVF, was unique given its location and the patient's age at presentation.

Central Nervous System Vascular Malformations↗

PubMed2000

Incidence and long-term prognosis of initial stroke and acute myocardial infarction in Okinawa, Japan.

We performed a cross-sectional survey of the incidence of stroke and acute myocardial infarction (AMI) in Okinawa, Japan, with a census population of about 1.2 million. A total of 3,644 cases of first-ever stroke and 898 cases of initial AMI were detected. The age-adjusted annual incidence rate of stroke was 105 per 100,000 of the standard population of Japan based on census population taken in 1985, and that of AMI was 26 per 100,000. The case-fatality rate of stroke within 28 days of onset was 12.8%, and that of AMI was 22.2%. Of the stroke cases, 51.4% were diagnosed as brain infarctions, 38.7% as brain hemorrhages, and 9.3% as subarachnoid hemorrhages. The diagnoses of stroke subtypes were confirmed by computed tomography or magnetic resonance imaging in 98.4% of all stroke cases. The long-term prognosis of patients with stroke and AMI was studied by examining their 10-yr survival rates (follow-up rate 89.8%). The cumulative survival rate was 38.2% in brain infarction cases, 40.4% in brain hemorrhage cases, and 38.2% in AMI cases. The 50% reduction of survival had occurred at 2,880 days after onset in brain infarction cases, at 2,764 days in brain hemorrhage cases, and at 2,658 days in AMI cases. In Okinawa, the incidence rate of AMI was still considerably lower than that in the Western population, and the rate of stroke was similar to that in the Western population. The ten-year survival rates were quite similar in AMI and stroke, and both were unexpectedly high.

Adult↗

PubMed2000

Comparison of the effect of blood pressure on the development of stroke, acute myocardial infarction, and end-stage renal disease.

Hypertension is a known risk factor for cardiovascular disease, but few epidemiological studies have examined simultaneously the effect of baseline blood pressure on the development of stroke, acute myocardial infarction (AMI), and end-stage renal disease (ESRD). In 1983, a large, community-based mass screening covered about 14% of the adult population in Okinawa, Japan. The total number of people screened was 107,192 (51,122 men, 56,070 women). We had access to two independent registries of end-organ damage: the Co-operative Study Group of Morbidity and Mortality of Cardiovascular Diseases in Okinawa (COSMO) registry for stroke and AMI, and the Okinawa Dialysis Study (OKIDS) registry for ESRD. The total number of people registered was 4,756 with stroke, 1,059 with AMI, and 641 with ESRD during the study period from April 1, 1988, to March 31, 1991. By using the name, sex, birth date, and ZIP code of registrants, we identified those registrants who were screened in 1983 and had developed stroke, AMI, or ESRD. Hypertension was defined as systolic blood pressure (SBP) of 140 mmHg or higher or diastolic blood pressure (DBP) of 90 mmHg or higher. Other readings were regarded as normotensive. The prevalence of hypertension was 35.8% (N=37,299). The cumulative incidence of stroke, AMI, and ESRD was 154, 21, and 19 subjects among those with SBP < or = 119 mmHg, and 1933, 315, and 71 subjects among those with SBP > or = 160 mmHg. Similarly, the incidence of stroke, AMI, and ESRD was 234, 44, and 25 subjects among those with DBP < or = 69 mmHg and 1980, 381, and 364 subjects among those with DBP > or = 110 mmHg. Hypertension was prevalent in the adult population in Okinawa, Japan, and was a significant predictor of stroke, AMI, and ESRD. However, the effect of blood pressure on target organs differed and was more evident in those with stroke than in those with AMI and ESRD.

Adolescent↗

PubMed2000

Control of blood pressure and lifestyle-related risk factors in elderly Japanese hypertensive subjects.

The aim of this study was to analyze the treatment of elderly hypertensive patients by Japanese physicians specializing in hypertension. We enrolled 939 patients with hypertension who were treated in the outpatient clinics of 11 hospitals in 1995; 793 of these patients (388 men and 405 women; mean age, 66.6+/-9.0 years) received follow-up examinations in 1996, and the data on these patients was used for the present analysis. Blood pressure (BP), body mass index, lifestyle, and laboratory data were analyzed in all patients. The average BP was 143+/-16/81+/-10 mmHg in 1995 and 142+/-15/80+/-10 mmHg in 1996. The patients whose baseline BP was at the level of Grade 2 or 3 in the WHO-ISH classification (n=117) were characterized by a higher women-to-men ratio, higher age, a higher serum total cholesterol concentration, and higher QRS voltage. In these patients, from 1995 to 1996, the average BP significantly decreased, whereas fasting plasma glucose, serum total cholesterol and serum creatinine concentrations showed only negligible changes. In 220 patients (28%), BP was <140/<90 mmHg at both the initial and the follow-up examinations, whereas 351 patients (44%) were hypertensive in both 1995 and 1996. Thirty-three percent of the patients were smokers. More smokers than nonsmokers had had prior cardiovascular events, diabetes mellitus, or overt proteinuria. In conclusion, the average BP level among the patients treated by Japanese physicians specializing in hypertension was somewhat higher than that recommended by WHO-ISH Guidelines (1999). Patient education to control lifestyle-related risk factors, particularly to stop smoking, should be emphasized.

Aged↗

PubMed2000

Non-corresponding effects of an angiotensin-converting enzyme inhibitor on cardiac and vascular hypertrophy in spontaneously hypertensive rats.

Angiotensin-converting enzyme inhibitors (ACEIs) may have different effects on cardiac hypertrophy than on vascular hypertrophy. Arginine vasopressin (AVP) may promote cardiac hypertrophy. Our aims were (1) to simultaneously examine the chronic effects of ACEIs on hypertrophy of the heart and hypertrophy of the coronary and renal interlobular arteries, and (2) to clarify the relation between AVP concentration (AVPC) and cardiac hypertrophy. ACEI (delapril: 30 mg/kg/day) or vehicle (5% arabic gum) was administered in a preventive (4 to 28 weeks of age) or a therapeutic (12-24 weeks of age) protocol in spontaneously hypertensive rats. In both protocols, delapril produced a slight but significant decrease in systolic blood pressure. In the therapeutic protocol, the weight of the left ventricle (mean+/-SE) was lower (p<0.05) in the ACEI group (64+/-2 mg/100 g body weight) than in the control group (69+/-1 mg/100 g body weight). Plasma renin activity was significantly higher in the ACEI group than in the control group in both the preventive (p <0.01) and therapeutic (p<0.01) protocols. In the therapeutic protocol, AVPC was significantly (p<0.05) lower in the ACEI group than in the control group. AVPC was significantly (p=0.02, r=0.46) correlated with the weight of the left ventricle in the therapeutic protocol. For both protocols, no differences were noted between the ACEI and control groups in the vascular hypertrophy of the coronary and renal interlobular arteries. We conclude that (1) the preventive or therapeutic effect of ACEIs on hypertrophy may not be the same in the heart as in the coronary and renal arteries; and (2) AVP was significantly correlated with the left ventricular weight. This indicates that AVP could play a role in the etiology of cardiac hypertrophy in SHR.

Aldosterone↗

PubMed1999

Serial MRI of cerebral infarcts before and after removal of an atrial myxoma.

We describe a cerebral infarct caused by atrial myxoma. A 30-year-old woman with an atrial myxoma presented with a right hemisensory deficit. MRI carried out before and after removal of the myxoma, showed multiple small bilateral white-matter infarcts which increased in number up to the surgery. A lesion in the left thalamus, which enlarged and showed contrast enhancement 4 months before surgery, resembled an old cerebral infarct by the time the myxoma was removed. The number of lesions stopped increasing after surgery. We suggest that atrial myxomas should be removed even in asymptomatic patients, to prevent cerebral infarcts due to embolism of tumour or thrombus.

Adult↗

PubMed1999

Pituitary abscess secondary to isolated sphenoid sinusitis.

Intracranial complications from isolated sphenoid sinusitis are rare but nevertheless demonstrate both a high morbidity and mortality. We herein report a case of a pituitary abscess secondary to sphenoid sinusitis in a 12-year-old boy. This patient presented with an acute onset of moderate fever and headache, followed by progressive right ptosis. An emergency endoscopic endonasal sphenoidotomy with sinus drainage and postoperative antibiotic therapy resulted in a satisfactory recovery.

Brain Abscess↗

PubMed1999

Sudden death in the general population in Okinawa: incidence and causes of death.

Sudden unexpected death is generally considered to be caused by acute myocardial infarction and/or arrhythmia. To document the incidence and causes of sudden death in Japan, where the incidence of myocardial infarction is low, the present study examined death certificates, hospital records, the forensic medical records, and the police records of residents of the southern part of Okinawa island who died at the age of 20-74 years during a 3-year period from January 1, 1992 to December 31, 1994. Sudden death was defined as death within 24 h from the onset of unexpected symptoms. The study documented 126 (87 men and 39 women) sudden deaths. The crude incidence rate was 0.37/1,000 person per year (0.51 in men and 0.23 in women). According to the death certificates, 78 cases died of heart diseases. However, the cause of death could be determined by examination of all available records in only 64 cases: myocardial infarction in 10, non-ischemic heart diseases in 13, and stroke in 23 cases. Even when the analysis was limited to the cases who died within 1 h from the onset of symptoms, heart disease was the cause of death in only 22% of the cases while the cause of death could not be determined in 53% of the cases. Only 13% of those diagnosed as heart diseases on the death certificate were verified. The agreement rate between the diagnosis reached by the re-evaluation of the records and that on the death certificate was 82% for stroke and 33% for other diseases. In Okinawa, Japan, the frequencies of heart disease and stroke as the cause of sudden death may be similar. Except for stroke, the diagnosis appearing on the death certificate has substantial inaccuracy.

Adult↗

PubMed1999

Low serum cholesterol as a risk factor for hemorrhagic stroke in men: a community-based mass screening in Okinawa, Japan.

The relation between the level of total serum cholesterol and stroke is controversial. The relation between serum total cholesterol and subtypes of stroke was examined in the participants of a community-based mass screening program in Okinawa, Japan. A total of 38,053 subjects, whose serum level of cholesterol had been determined during a mass screening carried out in 1983, were examined to see whether they had experienced stroke during a 3-year period from 1988 to 1991. Of them, 315 subjects aged 33-93 years (174 men, 141 women) had had a stroke during that period. The types of stroke were cerebral infarction in 164, cerebral hemorrhage in 111, subarachnoid hemorrhage in 19, and others in 21. In men, the odds ratio of cerebral hemorrhage was 0.71 (95% confidence interval, 0.55-0.95), and the odds ratio of cerebral hemorrhage associated with serum level of cholesterol < or =167 mg/dl, 168-191 mg/dl, 192-217mg/dl, and > or =218mg/dl were 1.00 (reference), 0.70 (0.38-1.30), 0.77 (0.55-1.08), 0.73 (0.56-0.96), respectively. Lower serum cholesterol was an independent predictor of cerebral hemorrhage in men.

Adult↗

PubMed1999

Divergent effects of beta-blocker therapy on self-estimated and objectively scored activities of daily living.

To identify factors that influence changes in the activities of daily living (ADL) assessed by a standardized scoring system, ADL-20, and factors affecting the self-estimate of the changes in ADL, we conducted a 1-yr follow-up study of 1,163 outpatients aged 50 yr or older. The follow-up rate was 83.1%. A decrease in the ADL score was associated with advancing age and a lower prescription rate of beta-blockers. Analysis of the modalities of ADL revealed an association between a decreasing mobility score and a lower prescription rate of beta-blockers. In patients with impaired ADL at the time of enrollment, worsening of the ADL score was also associated with a lower baseline ADL score and a history of cardiovascular events. The prescription rate of diuretics was lower in patients who exhibited an improvement in ADL score. There was a considerable dissociation between the self-estimate of changes in ADL and the actual change in ADL-20 score. In more than 60% of patients with impaired baseline ADL, the self-estimate of changes was worse than the actual change in the ADL score. The "worse-than-actual" self-estimate of changes in ADL was associated with a higher prescription rate of beta-blockers. Thus, a history of cardiovascular events accelerates the aging-related deterioration of ADL. The use of a beta-blocker may worsen the self-estimate of the changes in ADL, while the actual ADL is preserved or slightly improved during beta-blocker therapy.

Activities of Daily Living↗

PubMed1999

Factors related to impairment of activities of daily living.

OBJECTIVE: We examined the factors related to the impairment of activities of daily living (ADL). METHODS: ADL was evaluated by using ADL-20, which consists of 20 items from 4 major categories of activities; mobility, self-care, instrumental, and communication. The patients' gender, birth date, clinical diagnosis, past history, life styles, physical findings, laboratory data, and details of therapy were also recorded. Patients A total of 1,163 outpatients aged 50 years or older were included. Data from 1,093 patients were analyzed. RESULTS: We divided the subjects into two groups; Group I having full marks of ADL-20 (n=582) and group II exhibiting an impairment of ADL (n=511). Multiple logistic analysis revealed that in both sexes age and stroke were common independent factors related to the impairment of ADL. Other factors associated with impairment of ADL were smoking in men and presence of proteinuria in women. The presence of hyperlipidemia was associated with preservation of the ADL in women. CONCLUSION: The results demonstrated significant associations of smoking in men and the presence of proteinuria in women with the impairment of ADL in elderly Japanese outpatients. There appears to be a sex difference in the risk factors of impairment of ADL.

Activities of Daily Living↗

PubMed1999

[Clinical experience of image-guided neurosurgery with a frameless navigation system (StealthStation)].

We have applied the frameless navigation system (StealthStation) to various neurosurgical procedures to examine its usefulness. The system consists of a UNIX based workstation that creates triplanar and 3-dimensional images; an infrared optical digitizer with camera array; a reference-light-emitting diode (LED) array (e.g., reference array); and pointer probe modified by the addition of LEDs. This system was used to assist in placing a minimal skin incision and craniotomy in 4 cases, to determine the tumor/brain interface in 2 cases, to target the subcortical lesion in one case, and to correlate bony structure with a skull base tumor in 3 cases. The combined use with magnetic source imaging of the somatosensory cortex allowed a fast orientation of eloquent areas in 2 cases with peri-Rolandic tumor. This system, thus, was proved to be a useful adjunct to open-tumor biopsy or resection.

Adult↗

PubMed1999

[Carbamazepine induced hyponatremia].

Carbamazepine (CBZ) is a drug which can induce the syndrome of inappropriate antidiuretic hormone (SIADH). Until 1980's, there were reports regarding CBZ-induced SIADH, but it is rarely reported these days. We here report two cases of CBZ-induced SIADH. Hyponatremia in these cases was rapidly improved by withdrawal of administration of CBZ. According to the previous reports, the rate of hyponatremia in patients receiving CBZ is not small. It ranges from 48% to 31%. As CBZ is frequently used for patients with epilepsy and neuralgia, not only their blood CBZ concentration but also their serum Na level should be monitored.

Adult↗

PubMed1998

Effects of meal ingestion and active standing on blood pressure in patients > or = 60 years of age.

Postprandial hypotension and orthostatic hypotension occur often in elderly patients. In the present study, we examined hemodynamic and humoral responses to meal ingestion and active standing in 20 patients > or = 60 years of age who were free of apparent autonomic and cardiac dysfunction. For a time-control study, water was given instead of a meal to 19 of the 20 patients. After the meal ingestion, there was a fall in systolic blood pressure (BP) in 6 patients of > 20 mm Hg, whereas the fall in systolic BP during the control study was not > 20 mm Hg in any patient. The low-frequency power of the systolic BP wave, an index of peripheral sympathetic activity, was significantly increased only in the patients without postprandial hypotension. The postprandial changes in systolic BP were correlated with the changes in the low-frequency power of the systolic BP wave (r = 0.61; p < 0.01), but they were not correlated with the changes in plasma norepinephrine, insulin, cardiac output, or parameters obtained by the spectral analysis of the RR interval. The systolic BPs in the upright position were comparable after the meal and the water ingestion. Thus, the effects of meal ingestion and upright position on BP are not additive. Dysfunction of peripheral sympathetic control of vascular tone may contribute to the postprandial hypotension in elderly patients.

Aged↗

PubMed1998

Contribution of alpha 2-adrenoceptors in caudal ventrolateral medulla to cardiovascular regulation in rat.

The inhibitory action of alpha 2-agonists on the cardiovascular neurons has been elucidated in the rostral ventrolateral medulla (RVLM) but not in the caudal ventrolateral medulla (CVLM). Our study aimed to clarify whether microinjection of clonidine into the CVLM elicits any cardiovascular effect and whether endogenous alpha 2-adrenoceptor-mediated mechanisms contribute to the tonic activity of the CVLM neurons. In male Sprague-Dawley rats (7-9 wk old, 270-320 g) anesthetized with urethan, unilateral microinjection of 8 nmol of clonidine into the CVLM (n = 10) increased mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) by 12.1 +/- 1.8 mmHg (mean +/- SE, P < 0.01) and 25.8 +/- 4.8% (P < 0.01), while heart rate (HR) remained unaltered. Unilateral microinjection of 2 nmol of SKF-86466, a selective blocker of the alpha 2-adrenoceptors, into the CVLM (n = 10) decreased MAP, HR, and RSNA (-11.6 +/- 2.6 mmHg, -26 +/- 7 beats/min, and -15.3 +/- 1.7%, respectively, P < 0.01 for each). Artificial cerebrospinal fluid caused neither a cardiovascular effect nor a sympathetic response. Prior injection of SKF-86466 into the ipsilateral CVLM attenuated the effects of clonidine. Bilateral microinjection of muscimol into the RVLM abolished the effects of both clonidine and SKF-86466 injected into the CVLM. The pressor and sympathoexcitatory effects of clonidine injected into the CVLM suggest a neuroinhibitory action of the drug on the CVLM neurons. In addition, the depressor and sympathoinhibitory effects of SKF-86466 injected into the CVLM indicated that activation of alpha 2-adrenoceptors by endogenous ligand inhibits CVLM neurons. The effects of clonidine and the alpha 2-adrenoceptor antagonist in the CVLM require the integrity of the RVLM.

Adrenergic alpha-Agonists↗

PubMed1998

Prolonged NOS inhibition in the brain elevates blood pressure in normotensive rats.

Systemic inhibition of nitric oxide synthase (NOS) evokes hypertension, which is enhanced by salt loading, partly via augmented sympathetic activity. We investigated whether inhibition of brain NOS elevates blood pressure (BP) in normotensive rats and, if so, whether the BP elevation is enhanced by salt loading. After a 2-wk low-salt (0.3%) diet, male Sprague-Dawley (SD) rats were divided into four groups. Groups 1 and 2 received a chronic intracerebroventricular infusion of 0.5 mg . kg-1 . day-1 of NG-monomethyl-L-arginine (L-NMMA), and groups 3 and 4 were given artificial cerebrospinal fluid (aCSF). Groups 1 and 3 were placed on a high-salt (8%) diet, whereas groups 2 and 4 were on a low-salt diet. On day 9 or 10, group 1 showed significantly higher mean arterial pressure (MAP) in a conscious unrestrained state (129 +/- 3 mmHg vs. 114 +/- 3, 113 +/- 1, and 108 +/- 3 mmHg in groups 2, 3, and 4, respectively, P < 0.05). On a high-salt diet, response of renal sympathetic nerve activity but not of BP to air-jet stress was significantly larger in rats given L-NMMA than in rats given aCSF (29 +/- 4% vs. 19 +/- 3%, P < 0.05). When the intracerebroventricular infusions were continued for 3 wk, MAP was significantly higher in rats given L-NMMA than in rats given aCSF irrespective of salt intake, although the difference was approximately 7 mmHg. Thus chronic inhibition of NOS in the brain only slightly elevates BP in SD rats. Salt loading causes a more rapid rise in BP. The mechanisms of the BP elevation and its acceleration by salt loading remain to be elucidated.

Animals↗

PubMed1998

Relationship between serum cholesterol and the risk of acute myocardial infarction in a screened cohort in Okinawa, Japan.

Coronary heart disease (CHD) is rare in Japanese subjects and serum cholesterol levels are low. However, no data have been published relating the effect of serum cholesterol levels to the incidence of acute myocardial infarction (AMI) in Japan. Data from a large community-based mass screening registry are available for the geographically isolated island of Okinawa, Japan (1980 census, 1.11 million). A total of 38,053 participants (17,859 men and 20,194 women) whose serum cholesterol levels were determined in the 1983 mass screening were examined to determine whether they had experienced AMI. Every case of AMI that occurred during a 3-year period (1 April 1988 to March 1991) throughout Okinawa was recorded in a separate registry. The total number of cases of AMI was 1,021 (674 men and 347 women). Of these, 65 patients (41 men and 24 women) were identified by name, sex, birth date, and zip code in the mass screening registry. The cumulative incidence of AMI increased with the serum level of cholesterol: 42.1 (serum cholesterol < or = 167 mg/dl), 133.5 (serum cholesterol 168-191 mg/dl), 188.9 (serum cholesterol 192-217 mg/dl), and 323.0 (serum cholesterol > or = 218 mg/dl) per 100,000 screened subjects. Multiple logistic analysis was conducted to examine the effect of serum cholesterol on the risk of AMI with adjustment for other variables such as sex, age, systolic and diastolic blood pressure, and proteinuria. The adjusted odds ratio (95% confidence interval) of the observed serum levels of cholesterol was 1.66 (1.29-2.15) with a reference serum cholesterol level of < or = 167 mg/dl. The risk of AMI increased in proportion to the serum level of cholesterol. Serum cholesterol is an independent predictor of AMI in Okinawa, Japan.

Adolescent↗