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Biomedical subjects

S Okawara

Publications and source records attributed to S Okawara.

At least 19 recordsLinked to original sources
PubMed1992

[Hyponatremia and cerebral vasospasm in patients with aneurysmal subarachnoid hemorrhage].

We studied retrospectively the relationship between hyponatremia and cerebral vasospasm in 121 consecutive patients with aneurysmal subarachnoid hemorrhage. In 19 patients sodium levels fell below 130 mEq/l on at least two consecutive days. Hyponatremia developed at average 8.9 hospital day and lasted for 4.4 days. It was mild (126 to 130 mEq/l) in 15 patients, moderate (121 to 125 mEq/l) in 3 patients, and severe (116 to 120 mEq/l) in 1 patient. Cerebral vasospasm was evaluated by angiography, symptoms and CT finding. Angiographical vasospasm was found in 57 patients, symptomatic vasospasm in 38 patients and low density area on CT in 20 patients. Angiographical vasospasm developed in 15 of the 19 patients (78.9%) with hyponatremia, symptomatic vasospasm in 16 patients (84.2%), low density area on CT in 8 patients (42.1%), the difference being significantly high. (respectively, p < 0.01, p < 0.001 and p < 0.01 by chi-square test) Polyuria of 2500 ml or more immediately before the onset of hyponatremia developed in 14 patients (87.5%). When symptomatic vasospasm and hyponatremia coincided, there were only 4 patients in which symptomatic vasospasm was preceded by hyponatremia. So, it is difficult to predict the development of vasospasm from that of hyponatremia. This study found incidence of cerebral vasospasm after aneurysmal subarachnoid hemorrhage to be significantly higher in patients who developed hyponatremia, which raised suspicion about the presence of dehydration. Hyponatremia with central origin generally remains asymptomatic, but it is important to treat positively when the pathology of cerebral vasospasm is taken into consideration.

Dehydration↗
PubMed1992

[A study of plasma atrial natriuretic peptide, antidiuretic hormone and aldosterone levels in a series of patients with intracranial disease and hyponatremia].

For intracranial diseases, plasma atrial natriuretic peptide (ANP), antidiuretic hormone (ADH) and aldosterone were determined and their effects on the development of hyponatremia with central origin were studied. The subjects were 71 cases of intracranial diseases which were admitted to our hospital during a period of 1 year from March, 1989 to March, 1990. The diseases were broken down to subarachnoid hemorrhage 26 cases, hypertensive intracerebral hemorrhage 19 cases, head injury 12 cases, cerebral infarction 11 cases and 3 other cases. Serum-urine electrolytes, plasma ANP and ADH were determined in the acute stage on Day 1 to 4, in the hyponatremia stage on Day 5 to 14 and in the chronic stage on Day 15 downward. Hyponatremia was defined as the serum sodium level of 130 mEq/l or less. Cases evidently having other causes such as heart failure and renal insufficiency were excluded. In the normal control group of persons who were admitted to our hospital for a close checkup (n = 20), plasma ANP was 26.5 +/- 11.6 pg/ml (10-50); levels of 50 pg/ml or more were regarded as abnormally high. 1) Hyponatremia was found in 18 cases (25.4%), subarachnoid hemorrhage in 7 cases, hypertensive intracerebral hemorrhage in 4 cases, head injury in 5 cases and others in 2 cases. 2) The time of onset of hyponatremia was on the 8.3 hospital day. The duration was 7.2 days. The minimum serum sodium level was 124.6 mEq/l. 3) There was no significant change in the plasma aldosterone level at each stage.2+ Predicting development of hyponatremia from plasma ADH and ANP levels in the acute stage is difficult. Inadequate secretion of ANP rather than ADH appeared to be an important factor for the development of hyponatremia, but the plasma ANP level was not always abnormally high, so involvement of other sodium diuretic factors should also be kept in mind.

Adult↗
PubMed1991

[CT and 123I-IMP SPECT findings of head injuries with hyponatremia].

CT and SPECT findings were examined and the relationship between development of hyponatremia and lesions was studied in cases who developed hyponatremia following head injury. Six cases of hyponatremia after head injury in the last two years were used as the subjects. SPECT was performed by the 123I-IMP intravenous injection method using Tomomatic 64. Slice 2 of 4 to 6 cm on the OM line in the early image was used as the subject site. The data of development of hyponatremia was 5.8 patients days, duration 9.2 days, minimum serum Na level 117.2 mEq/l and minimum plasma osmotic pressure 247.6 mOsm/lH2O. CT findings in the hyponatremic stage showed frontal subdural effusion in all the cases. SPECT findings revealed a decrease of CBF in the frontal region on both sides and in the central region. CBF in the central region also tended to improve at a time when hyponatremia improved. In hyponatremia after head injury, lesions are often found in the frontal region on CT, and CBF in the central region is also decreased bilaterally on SPECT, which is presumed to be concerned with the development of hyponatremia.

Adult↗
PubMed1991

[Serum ANP and ADH after subarachnoid hemorrhage and hyponatremia].

We determined serum atrial natriuretic peptide (ANP) and anti-diuretic hormone (ADH) on a time course basis in cases of subarachnoid hemorrhage and studied their influence on the development of hyponatremia. Twenty six cases of subarachnoid hemorrhage were admitted to our hospital in the past 1 year, and by the site of ruptured aneurysms, there were Acom 6 cases, ICA 6 cases, MCA 5 cases and VA BA 4 cases. Serum ANP and ADH levels were determined in the acute phase on Day 1-4, in the hyponatremia phase on Day 5-14 and in the chronic phase on Day 15 downward. Levels of not more than 130 mEq/l were regarded as hyponatremia. Cases showing other evident causes such as heart failure and renal insufficiency were excluded. In the normal control group (n = 20) which was admitted to this hospital for a close check-up, serum ANP was 26.5 +/- 11.6 pg/ml (10-50); levels of more than 50 pg/ml were regarded as being abnormally high. 1) Hyponatremia was observed in 7 cases (26-9%); the day of onset was 11.9 hospital day. The duration was 5.0 days and the minimum serum Na level was 126.4 mEq/l. 2) The serum ADH level was high regardless of whether or not there was the development of hyponatremia in the acute phase but tended to decrease gradually and became normal in the hyponatremia phase. 3) The serum ANP level in the cases of hyponatremia was 40.7 +/- 9.1 pg/ml in the acute phase, 69.0 +/- 25.7 pg/ml in the hyponatremia phase and 40.2 +/- 21.5 pg/ml in the chronic phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Natriuretic Factor↗
PubMed1991

[Internal carotid artery stenosis and external carotid artery occlusion with unusual extracranial collateral pathway: case report].

A patient with stenosis of the internal carotid artery and occlusion of the external carotid artery associated with an unusual extracranial collateral pathway is presented. A 63-year-old man was hospitalized for sudden onset of black-out after urination. He was alert, and no neurological deficit was found. MRI showed multiple lacunae in the bilateral putamens. Cerebral angiogram demonstrated severe stenosis of the left internal carotid artery at its cervical segment and complete occlusion of the left external carotid artery at its origin. The ascending pharyngeal artery originated from the left internal carotid artery above its stenotic lesion and the superior thyroid artery originated from the left common carotid artery. The sternocleidomastoid branch from the left superior thyroid artery and the muscular branch from the left vertebral artery anastomosed with the muscular branch of the ascending pharyngeal artery. The ascending pharyngeal artery maintained patency of the internal carotid artery. It is important to perform vertebral angiography when there is proximal occlusion and severe stenosis of the internal carotid artery, and when the ascending pharyngeal artery has not been clearly identified as a branch from the ipsilateral external carotid artery on the common carotid angiogram.

Arterial Occlusive Diseases↗
PubMed1990

[An interesting case of pituitary apoplexy showing abnormality in water-electrolyte before and after surgery].

Cases which present abnormality in water-electrolyte before and after operation of pituitary adenoma are occasionally reported. The authors have encountered a case in which neurological symptoms became aggravated abruptly with pituitary apoplexy after admission, hyponatremia was noted before operation and polyuria, not hypotonic urine was observed after operation. As a result of an endocrinological examination which may have an influence on water-electrolyte (ADH, aldosterone, ANP, etc.) the ADH level in hyponatremia before operation was high at 6.8 pg/ml; so, it was taken as SIADH. According to a study at the time of polyuria after operation, the ADH level was normal at 2.4 pg/ml, the ANP level was abnormally high at 140 pg/ml and the specific gravity of the urine was kept at 1.010 or more. So, polyuria was considered due to abnormally increased content of serum ANP. In polyuria due to abnormally increased content of serum ANP, the osmotic pressure of the urine is maintained relatively well, which is a clinical feature evidently different from diabetes insipidus. After operation for pituitary adenoma, water-electrolyte should be controlled with polyuria due to abnormally increased content of serum ANP in addition to diabetes insipidus taken into consideration.

Atrial Natriuretic Factor↗
PubMed1990

[Subacute subdural hematoma--report of 4 cases and a review of the literature].

Subdural hematoma is divided roughly into two types acute and chronic. The two show an entirely different mode of illness. The authors have encountered 4 cases of subacute subdural hematoma in which characteristics of both types coexisted. These cases are characterized by the following. 1) The disease develops in the elderly persons with a history of trauma unknown or after minor head injury. 2) There is a relatively long period of clear consciousness and they visit a hospital when they are in the subacute stage, 3) They have a history of drinking alcohol heavily as a habit and there is a high risk of hypertension and diabetes. 4) Brain CT findings sometimes reveals mixed density hematoma. 5) Hemorrhage from the cortical artery is occasionally noted as the operative findings. Hematoma membrane is absent. 6) The outcome is generally poor because of systemic complications. As described above subacute subdural hematoma was similar to chronic subdural hematoma in the clinical course and CT findings. But operative findings of this disease indicated acute subdural hematoma. Repeated minor hemorrhage, related to coagulation disorder and brain atrophy would be important as the mechanism of subacute subdural hematoma. The effectiveness of perforation craniotomy as radical operation was low and removal of hematoma by major craniotomy was needed. The concept of subacute subdural hematoma is considered important in deciding on a therapeutic policy.

Acute Disease↗
PubMed1990

[Infarction in the territory of the anterior choroidal artery due to embolic occlusion of the internal carotid artery--report of two cases].

A case with infarction in the territory of the anterior choroidal artery (AChA) due to embolic occlusion of the internal carotid artery (ICA) is rare. We described two cases and investigated the mechanism of the territory of the AChA. Case 1 was a 69-year-old man. Case 2 was a 71-year-old woman. The neurological examination in both cases showed left homonymous hemianopsia, left facial palsy, left hemiparesis and left hemisensory disturbance. CT scan in these cases showed infarctions of the right uncus, amygdaloid nucleus, genu and posterior limb of the internal capsule, globus pallidus, lateral geniculate body and tail of the caudate nucleus. The right common carotid angiogram showed a complete occlusion of the ICA at its cervical segment in case 1 and at its carotid siphon in case 2. In both cases, the left carotid injection visualized the right anterior cerebral artery and right middle cerebral artery via the anterior communicating artery well, but the right AChA was not visualized. In case 1, the collateral pathways from the right external carotid artery (ECA) and the right posterior communicating artery (PCoA) to the right ICA were not supplied and the precommunicating segment of the right posterior cerebral artery was hypoplastic. In case 2, the collateral pathway from the right ECA to the right ICA was not supplied.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

[Evaluation of CT-guided stereotaxic aspiration for thalamic hemorrhage by single photon emission CT].

Sixteen patients with thalamic hemorrhage (hematoma volume greater than or equal to 10 ml and CT classification greater than or equal to IIa) were included in this study. In sixteen patients, ten were treated conservatively (conservative group) and six were subjected to CT-guided stereotaxic aspiration (aspiration group). Stereotaxic aspiration was performed at the acute stage within five days after the onset. We measured cerebral blood flow (CBF) using Single Photon Emission CT (Tomomatic 64) and 133-Xe inhalation method. In both groups, CBF was measured at the onset (day 1-5), acute stage (day 7-13), subacute stage (1 month from the onset) and chronic stage (2-4 months from the onset). In this study, mean hemispheric cerebral blood flow (mCBF) was calculated from the middle slice 2, positioned 5cm above the orbitomeatal line. Regional devision of slice 2 in the hematoma side was made as follows. rCBF-A: regional cerebral blood flow in the anterior area of the hematoma. rCBF-L: regional cerebral blood flow in the lateral area of the hematoma. rCBF-P: regional cerebral blood flow in the posterior area of the hematoma. In both groups, age, neurological grading, CT classification and hematoma volume had no significance. In the conservative group, mCBF of the hematoma side in the subacute stage was 68 +/- 7%, and in the aspiration group it was 85 +/- 17%. This difference was statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1989

Rodent and primate adrenal medullary cells in vitro: phenotypic plasticity in response to coculture with C6 glioma cells or NGF.

In order to maintain a chronic supply of growth factor for medulla cells in vitro, chromaffin cells from rat, African green monkeys and man were co-cultured with C6 glioma cells, which secrete growth factors that sustain sympathetic neurons in vitro. The response of chromaffin cells to coculture was compared to treatment of medullary cells with nerve growth factor (NGF) alone. Dispersed chromaffin cell preparations were obtained by a trypsin-collagenase procedure, and subjected to differential plating on collagen-coated surfaces. With both human and monkey tissue, non-chromaffin cells did attach to the culture plates and an enriched chromaffin cell population could be replated. Rat adrenal medulla cells survived very poorly in vitro and were not enriched in this procedure. Cultured human and monkey chromaffin cells survived as epithelial cells (50%) and showed neuritic outgrowth on 55 to 66% of the cells after eight days when treated with nerve growth factor (NGF). These cells showed strong catecholamine histofluorescence, tyrosine hydroxylase (TH) and dopamine beta hydroxylase (DBH) immunoreactivity. In contrast, only ten percent of adult rat chromaffin cells survived in culture, although NGF treatment rescued an additional 20% of the cells and induced neuritic outgrowth after one week in vitro. C6 glioma cells were treated with mitomycin C bromodeoxyuridine to inhibit mitosis and were plated with the various medulla cells in a one to one ratio. Both human and monkey chromaffin cells expressed extensive and enhanced neuritic arborization within eight days of co-culture, (64-82% respectively) and exhibited intimate contact with the glioma cells as seen at the ultrastructural level. Importantly, survival of adult rat adrenal medulla cells was enhanced to 50% or more with 40% of the cells extending neurites when co-cultured with glioma cells for seven days. Chromaffin cells from all three species reacted for TH, DBH and PNMT in co-culture and were histo-fluorescent. The majority of these cells were also immunoreactive for serotonin and enkephalin, while only 37% of chromaffin cells indicated the presence of NPY. These data indicate that adrenal medulla can be maintained in vitro as the neuronal phenotype when co-cultured with growth factor producing cells and that this strategy may be useful for in vivo transplantation studies.

Adrenal Medulla↗
PubMed1989

[Cerebral blood flow in patients with thalamic hemorrhage (Part 2): Etiological analysis of decreased cerebral blood flow in acute stage].

In twenty-nine patients with thalamic hemorrhage, single photon emission CT (SPECT) and CT were performed in the acute stage. Measurement of cerebral blood flow (CBF) was performed by the 133-Xe inhalation method using SPECT (Tomomatic 64). CT findings such as hematoma volume, involvement of internal capsule, ventricular hematoma and topographical localization of hematoma were investigated. We studied etiological analysis of decreased CBF in the acute stage. CBF values in the group of large-volume hematoma (greater than or equal to 10 ml) decreased moderately on the hematoma side and mildly on the nonhematoma side. CBF values in the group of small-volume hematoma (less than 10 ml) decreased mildly on the hematoma side but didn't decrease on the nonhematoma side. CBF values of the former on the hematoma side decreased significantly compared with the latter. Linear correlation between hematoma volume and CBF was significant. As to topographical localization, CBF values of the group which involved medial thalamus decreased significantly compared with the other group. Factors of involvement of internal capsule and ventricular hematoma didn't affect CBF values. In conclusion, major factors which affected decreased CBF in the acute stage were hematoma volume and tomographical localization.

Acute Disease↗
PubMed1988

[Cerebral blood flow in patients with thalamic hemorrhage--Part 1: Serial changes of cerebral blood flow in conservatively treated patients].

Serial changes of cerebral blood flow (CBF) in nine patients with thalamic hemorrhage are studied. Measurement of CBF was performed in 3 times (acute, subacute and chronic stage) by the 133 Xe inhalation method using rapidly rotating single photon emission CT (SPECT, Tomomatic 64). The outcome was judged at 16 weeks from onset according to the activities of daily life. All patients divided into two groups (good group and poor group) [Result] 1. Serial changes in mean hemispheric CBF (mCBF) of both hematoma and nonhematoma side between good group and poor group. Between two groups, the significant difference was observed only in hematoma side was 77% CBF in acute stage and it was gradually improved in subacute stage. mCBF of nonhematoma side was normal value in all stage. In poor group, mCBF of hematoma side was 64% CBF in acute stage and it was slightly improved in chronic stage (70% CBF). Slice 2 mCBF of nonhematoma side was 69% CBF in acute stage and it was improved in subacute (74% CBF) and chronic (78% CBF) stage. 2. Serial changes in regional CBF (rCBF)--H (hematoma area).A (anterior area of hematoma).L (lateral area of hematoma).P (posterior area of hematoma) of hematoma side between good group and poor group. Between two groups, the significant differences were observed in rCBF-H.L.P on subacute stage and rCBF-P on chronic stage. Serial changes in rCBF were similar to those in slice 2 mCBF of hematoma side. 3. Serial changes in rCBF-H.A.L.P of nonhematoma side between good group and poor group.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1986

Neurologic complications in diabetics after metrizamide lumbar myelography.

Recognized risk factors for metrizamide myelography are seizure disorder, seizure-threshold-lowering drugs, dehydration, and possibly age. After observing serious neurologic complications in diabetic patients after routine metrizamide myelography, a retrospective study was conducted to determine if diabetes should be considered another independent and important risk factor. Forty-one diabetic patients who had lumbar metrizamide myelograms were compared with a control group of 110 nondiabetic patients. A significantly higher incidence was found of severe vomiting (15% vs. 3%, p less than 0.01) and neurologic complications (20% vs. 2%, p less than 0.001) in the diabetic population. Neurologic complications included one case each of seizure, severe encephalopathy, auditory and visual hallucinations, and prolonged somnolence and four cases of confusion-anxiety. Four of the diabetic patients had major transient elevations of blood pressure. These findings suggest that diabetics are a high-risk population for metrizamide myelography. The dose of metrizamide should be minimized, whenever possible. The new nonionic myelographic agents may prove to be safer in this population, but caution and careful follow-up should be exercised in the initial trials with these patients.

Aged↗
PubMed1975

Tele-Autotomogram and Application of the Pneumoencephalographic Chair in Stereotactic Operations.

In order to obtain clearly demonstrated reference points in a preliminary air study for target calculations in stereotactic brain operations, a tele-autotomogram taken with the rotating pneumoencephalographic chair has been used with excellent results. By means of multiaxial rotations of the chair, tele-roentgenograms, including an autotomogram with a constant small magnification, can be obtained easily at any position of the patient with one floor X-ray tube. The same chair, modified to support the stereotactic base ring, can serve as an excellent stereotactic operating table with good maneuverability, offering wide adjustment of the patient's position suitable for various operative approaches. Simultaneously, it produces identical tele-roentgenograms with the same magnification as in the preliminary study, which economizes calculation time and avoids possible measurment error during stereotactic operations.

Humans↗