Biomedical subjects

M Kitani

Publications and source records attributed to M Kitani.

At least 37 records · Page 2Linked to original sources

PubMed1994

[Unilateral posterior spinal artery syndrome of the upper cervical cord associated with vertebral artery occlusion].

Upper cervical cord infarction in the territory of the posterior spinal artery is very rare. We present here an elderly man who developed right upper cervical (C1-2) posterior spinal artery syndrome associated with vertebral artery occlusion. A 62-year-old man suffered a right upper cervical (C1-2) posterior spinal artery syndrome. The onset was associated with neck flexion. Magnetic resonance imaging clearly showed an ischemic lesion. Cerebral angiography revealed occlusion of the distal end of an ipsilateral vertebral artery. The occlusion of the vertebral artery probably caused the cervical cord infarction. The neck flexion possibly induced thrombogenesis in the vertebral artery. Unilateral upper cervical posterior spinal artery syndrome associated with vertebral occlusion following neck flexion was suggested.

Humans↗

PubMed1993

Stereoselective high-performance liquid chromatographic assay for the determination of OPC-18790 enantiomers in human plasma and urine.

A high-performance liquid chromatographic assay method for the quantification of OPC-18790 enantiomers in human plasma and urine is described. A human plasma or urine was extracted with organic solvent under alkaline conditions following the addition of internal standard. The enantiomers and internal standard were then derivatized by reaction with the chiral reagent GITC (2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl isothiocyanate), followed by octadecylsilica chromatographic separation of the diastereomeric products. The mobile phase consisted of acetonitrile-water (41:59). The fluorescence of the eluate was monitored at 355/405 nm. The lowest quantification limit of each enantiomer was 10 ng/ml in plasma and 0.1 micrograms/ml in urine. Both intra- and inter-day coefficients of variation were below 10%. The assay is sensitive, specific and applicable for stereoselective pharmacokinetic studies in human.

Cardiotonic Agents↗

PubMed1993

[Acute respiratory arrest associated with medullary lesion in a case of multiple sclerosis].

We present a case history of a patient with multiple sclerosis who developed an abrupt onset of respiratory arrest associated with medullary lesion. A 27-year-old man developed shallow, totally irregular, ataxic respirations with aggravation of bulbar palsy and quadriplegia in the course of multiple sclerosis. As respiration was almost arrested, artificial respiration was started and continued for five days. Respiration was almost normal after 16 days from the onset of respiratory arrest. MRI showed bilateral, medullary lesions without upper cervical lesions. Pyramidal tracts, medial lemnisci, and paramedian reticular formations in medulla were damaged bilaterally. We supposed that the medullary lesions involved dual respiratory systems: a voluntary system and an automatic system, and caused acute respiratory arrest.

Acute Disease↗

PubMed1993

[A case of hereditary motor and sensory neuropathy with vocal cords palsy and diaphragmatic weakness].

A case of hereditary motor and sensory neuropathy (HMSN) type 1 (Charcot-Marie-Tooth disease (CMT)) is reported with vocal cords palsy, deafness, diaphragmatic weakness, and cerebellopontine atrophy. A 42-year-old man was admitted to our hospital in April, 1991 with marked respiratory distress. He had been diagnosed as having CMT 14 years previously. On admission to our hospital, he revealed dyspnea with marked stridor during inspiration. Physical examination showed marked use of respiratory accessory muscles with thoracoabdominal paradox in the supine position. Neurologic examination revealed tonic pupils, mild bilateral weakness of facial muscles, deafness, mild bulbar palsy, severe wasting and weakness in both proximal and distal muscles of the arms and legs, areflexia, distal loss of all sensory modalities. Pes cavus and hammer toe were present. Movement of upper extremities was ataxic. No hypertrophic changes were noted in his peripheral nerves. Peripheral nerve conduction study showed undetectable both sensory and motor action potentials. Electromyography showed evidence of denervation, more marked in distal muscles. Auditory brain stem response was undetectable. Chest radiographic film showed a normal-sized heart with marked elevation of both hemidiaphragm. Laryngofiberscopy confirmed the presence of bilateral vocal cord paralysis without tumor formation, inflammation or anomaly. The vocal cords lay near the midline and did not show any movement during respiration. Moderate cerebellopontine atrophy was confirmed on MRI scan. A sural nerve section showed severe decrease of myelinated fibers, and onion bulbs. Diagnosis of HMSN type 1 was made by clinical, electrodiagnostic, and sural nerve sections study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Cerebral atrophy precedes the change in cerebral blood flow in patients with ischemic cerebrovascular disease: a short-term follow-up study.

Cerebral atrophy and the decrease in cerebral blood flow (CBF) progress with advancing age. Which of them takes first place, the changes in CBF or cerebral atrophy? We investigated longitudinal changes in CBF and cerebral atrophy in 14 patients with ischemic cerebrovascular disease (CVD): 11 patients with supratentorial lacunar infarction and 3 with carotid transient ischemia attack who were neurologically stable during the 1-3 years of observation. Cerebral atrophy was estimated by the brain atrophy index (BAI): one of the CT area measurement methods, and CBF was measured using the 133Xe inhalation technique. While significant progression of cerebral atrophy was observed, there was no significant change in CBF. Cerebral atrophy precedes the change in CBF and CVD.

Aged↗

PubMed1990

Computerized tomography with longitudinal follow-up of brain atrophy in patients with Parkinson's disease.

Computerized tomographic (CT) studies with longitudinal follow-up of the relationship between supratentorial and infratentorial brain atrophy in Parkinson's disease (PD) using our new CT-derived brain atrophy index (BAI) are reported. In those patients with Parkinson's disease, CT analysis demonstrated a significant increase in brain atrophy compared with controls. Infratentorial BAI correlated significantly with supratentorial BAIs and the decrease in the infratentorial BAI correlated with a corresponding decrease in the supratentorial BAI in those with PD. It is postulated that the infratentorial brain atrophy found in patients with PD could well be secondary to supratentorial brain atrophy.

Adult↗

PubMed1990

[Cognitive function, cerebral blood flow and brain atrophy in olivo-ponto-cerebellar atrophy].

UNLABELLED: Eighteen cases of OPCA (9 males and 9 females, age 39-70, mean 57.8 +/- 8.1 years). Mean duration of illness was 65.7 +/- 36 months. Age-matched controls for Brain-CT were 34 cases (13 males and 21 females) (age 39-70, mean 56.8 +/- 9.4 years), in which CT was examined because of functional disorders, and 50 healthy volunteers (25 males and 25 females) (age 36-72, mean 56.6 +/- 7.9 years) for regional cerebral blood flow (rCBF) and mental function. Brain Atrophy Index (BAI) and Ventricular Atrophy Index (VAI) were calculated by digitizer (PCPAD) on CT films in the slice of lateral ventricle level, basal ganglia level and cerebello-pontine level. There were 10 patients of OPCA who examined CT prior to this study. Interval of the two examinations was 21-76 months, mean 53 months. Regional cerebral blood flow (rCBF) were measured by 133 Xe inhalation methods. Intelligence were evaluated with Okabe's Intelligence Scale (Shortened and modified Wechsler's Memory Scale for Japanese Aged) and Kohs' Block Design Test. Depressive state was evaluated with Zung's Self-rating Depression Scale (SDS). RESULTS: 1) Cerebello-pontine atrophy was significantly prominent but no cerebral atrophy was observed in OPCA. 2) The rCBF was mildly but significantly reduced in OPCA. 3) Performance and verbal intelligence were significantly low in OPCA. 4) OPCA patients showed significant depressive state. 5) Grade of ADL did not show significant participation in the rCBF, intelligence and depressive state. 6) There was no significant correlation between duration of illness and rCBF or mental functions. 7) Cerebello-pontine atrophy significantly progressed in OPCA patients followed-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Effects of an antithrombotic agent (MD-805) on progressing cerebral thrombosis.

The effects of the newly developed synthetic selective antithrombin agent MD-805 were examined in 11 patients with progressing cerebral thrombosis, as an open trial. Nine (82%) of 11 patients improved after 1 week of intravenous drip infusion. No hemorrhagic complications were observed during the therapy. These results suggest that MD-805 is a safe and effective agent for treatment of progressing cerebral thrombosis.

Aged↗

PubMed1989

Pial arterial pressure contribution to early ischemic brain edema.

The effect of pial arterial pressure (PAP) on brain edema was examined in cats with middle cerebral artery (MCA) occlusion. Measurements of PAP and regional CBF (rCBF) were collected in the central core and the peripheral margin of the MCA territory over 180 min post MCA occlusion. Brain water content in each region was determined at the end of the experiment. MCA occlusion resulted in decreased PAP and rCBF in both the core (PAP = 13 mm Hg, rCBF = 9 ml/100 g/min) and the peripheral region (PAP = 15 mm Hg, rCBF = 18 ml/100 g/min). Brain edema developed in both the core and the peripheral region. Brain water content was correlated inversely with PAP in the core region and positively in the peripheral region. The results indicate that decreased blood flow contributes to cytotoxic edema in the core, and a hydrostatic pressure gradient preferentially enhances edema formation in the peripheral region. Maintenance of high perfusion pressure early after ischemia onset may suppress brain edema in the core region.

Animals↗

PubMed1989

Correlation between carotid blood flow and brain atrophy in patients with multi-infarct dementia.

The relation between carotid blood flow measured by Doppler spectrum analysis and brain atrophy on computed tomography (CT) was studied in 22 subjects with multiple lacunar cerebral infarctions. The subjects were divided into two groups, 7 patients with multi-infarct dementia (MID) (mean age 73 years) and 15 nondemented lacunar stroke subjects (NDLS) (mean age 66 years), according to DSM III criteria. All subjects had a score of 7 points or more on Hachinski's ischemic score and showed no carotid artery stenosis. Systolic peak frequency of the common carotid artery (CCA) was measured by Doppler spectrum analysis (Angioscan II). Brain atrophy was measured quantitatively on CT images by two-dimensional measurement using a digitizer. Peak frequencies were lower in MID than in NDLS. Brain atrophy was more severe in MID than in NDLS. There was a significant correlation between peak frequencies and brain atrophy in all subjects. These results indicate that CCA blood flow may reflect brain function in patients with multiple lacunar infarctions.

Aged↗

PubMed1989

[Responses of cerebral arteries to the changes in cerebral perfusion pressure].

The responsiveness of cerebral pial arteries and arterioles to changes in systemic arterial blood pressure (SAP) was investigated. Using 9 cats anesthetized with chloralose and urethane, direct, simultaneous measurements of pial arterial pressure (PAP) and cerebral blood flow (CBF) were made during changes in SAP. SAP was varied between 25 and 140 mmHg by the hemorrhage and blood infusion methods. After a partial craniotomy. PAP was measured with a micropipette connected to a servo-controlled micropressure recording system. Punctured pial arteries were grouped into three types according to their diameters, 1A (291 +/- 33 microns), 2A (16 +/- 26 microns), and 3A (70 +/- 10 microns). CBF on the exposed cortex was measured with hydrogen clearance method. The PAPs measured were a linear function of SAP; PAP (1A) = 0.73/SAP-6.6 (r = 0.96), PAP (2A) = 0.62 X SAP-6.6 (r = 0.90), PAP (3A) = 0.61 X SAP-6.4 (r = 0.93). The result indicates that PAPs are entirely dependent on SAP and that SAP induced changes in PAPs are less in the smaller pial arteries. Regional CBF remained constant (55 +/- 4 ml/100 g/min) between 60 and 140 mmHg of SAP. A significant decrease in CBF was observed below 60 mmHg of SAP. Cerebrovascular resistances were calculated segmentally using the following formulas; large vessel resistances (LVR) = (SAP-PAP(1A]/CBF, middle vessel resistance = (PAP (1A)-PAP (3A]/CBF, and small vessel resistance = PAP (3A)/CBF. The changes in LVR, MVR, and SVR were almost identical between 70 and 140 mmHg of SAP. Below 70 mmHg of SAP, SVR showed the greatest decrease in resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1988

Flow thresholds for cerebral energy disturbance and Na+ pump failure as studied by in vivo 31P and 23Na nuclear magnetic resonance spectroscopy.

The relationships among CBF, cerebral energy metabolism, Na+ pump activity, and electrocorticograms (ECoG) following graded hypotension were studied in 48 gerbils. Energy metabolism and Na+ pump activity were estimated by in vivo 31P and 23Na nuclear magnetic resonance (NMR) spectroscopy, and CBF was determined by [14C]iodoantipyrine methods at the end of the experiments. The CBF measured in normotensive animals was 0.51 +/- 0.07 ml/g brain/min. Following graded hypotension, no 31P spectral change was observed until CBF fell to 0.21-0.27 ml/g brain/min, at which level the intracellular pH began to decrease in association with ECoG voltage reduction. At a CBF level of 0.18-0.23 ml/g brain/min, phosphocreatine (PCr) began to decrease in association with inorganic phosphate (Pi) elevation. At this level, ECoG became isoelectric, although no adenosine triphosphate (ATP) change yet resulted. At a flow level of 0.12-0.14 ml/g brain/min, ATP began to decrease gradually. At 0.04-0.05 ml/g brain/min, PCr and ATP virtually disappeared, and the 23Na signal intensity suddenly changed. The present study demonstrated flow thresholds for the development of tissue acidosis, PCr-Pi changes, and ATP reduction. It appears that functional suppression occurs prior to ATP changes, whereas Na+ pump failure results after ATP depletion.

Animals↗

PubMed1988

Effect of smoking on regional cerebral blood flow in the normal aged volunteers.

The effects of long-term cigarette smoking on regional cerebral blood flow (rCBF) were studied in 67 normal male volunteers. All subjects were healthy volunteers without any past history of cerebral and pulmonary disease. rCBF decreased significantly with advancing age. Although there was no significant difference in rCBF between young smokers and nonsmokers, elderly smokers showed significantly lower rCBF than elderly nonsmokers. There was no difference in vital capacity and FEV 1.0% between smokers and nonsmokers in both young and elderly groups. The smokers, however, showed significantly lower V50 than the nonsmokers. PeCO2 in smokers was significantly lower than in nonsmokers. No significant differences were seen in hematocrit, antithrombin III, aggregating platelet, serum lipids and blood pressure between smokers and nonsmokers in both age groups. There was a significantly positive correlation between rCBF and PeCO2 in all groups. These results suggest that long-term smoking may reduce rCBF by means of hypocapnia, resulting from latent small airway disturbances, not by advancing cerebral arteriosclerosis.

Aged↗

PubMed1988

Effect of long-term administration of buflomedil on regional cerebral blood flow in chronic cerebral infarction.

The influence of long-term oral administration of buflomedil on regional cerebral blood flow was investigated in 10 patients with chronic cerebral infarction and mild to moderate mental deterioration. Patients were given 150 mg buflomedil three times daily for a period of eight weeks. Regional cerebral blood flow (rCBF) was measured in patients before they began buflomedil treatment and during the last week of treatment. The interval of the rCBF measurements in the control subjects (n = 12) ranged from seven to forty-eight days. Mental function in the patients studied was evaluated by use of Hasegawa's simple intelligence scale for the aged and Zung's self-rating depression scale, before and during the last week of buflomedil treatment. The results showed a mean increase in rCBF of 10.5% +/- 12.1% in the patient group. The control group demonstrated virtually no change in rCBF measurements. Improvements in the mental function scores of the buflomedil-treated group were noted, and 5 of the 10 patients reported improvement in subjective symptoms.

Cerebral Infarction↗

PubMed1988