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Biomedical subjects

F Sakai

Publications and source records attributed to F Sakai.

At least 127 records · Page 7Linked to original sources
PubMed1991

Increase in cerebrospinal fluid and plasma levels of 3-methoxy-4-hydroxyphenylglycol in acute stroke.

BACKGROUND AND PURPOSE: 3-Methoxy-4-hydroxyphenylglycol is known to be a principal metabolite of brain norepinephrine and to be released into the blood and cerebrospinal fluid in association with activation of the central noradrenergic system. We examined changes in plasma and cerebrospinal fluid levels of 3-methoxy-4-hydroxyphenylglycol during acute stroke to see if there might be a correlation between these and the patient's clinical state. METHODS: We measured plasma levels of 3-methoxy-4-hydroxyphenylglycol in 32 control subjects and in 50 patients with brain hemorrhage and 57 patients with brain infarction who were admitted to the hospital within 72 hours after onset. In addition, we estimated 3-methoxy-4-hydroxyphenylglycol concentrations in the cerebrospinal fluid of 37 patients with brain infarction and eight control patients. RESULTS: Mean +/- SEM values for plasma 3-methoxy-4-hydroxyphenylglycol in the patients with brain hemorrhage and those with brain infarction were 7.3 +/- 0.5 and 6.6 +/- 0.5 ng/ml, respectively. Both values were significantly higher than that obtained in the 32 control subjects (4.6 +/- 0.3 ng/ml, p less than 0.01). Plasma levels of 3-methoxy-4-hydroxyphenylglycol correlated well with state of consciousness and prognosis. The mean +/- SEM level of 3-methoxy-4-hydroxyphenylglycol in the cerebrospinal fluid of the 37 patients with brain infarction (10.9 +/- 0.6 ng/ml) was also significantly higher than that in the eight control patients (7.9 +/- 0.6 ng/ml, p less than 0.01). CONCLUSIONS: The observed increase in plasma and cerebrospinal fluid levels of 3-methoxy-4-hydroxyphenylglycol implies that the activity of the central noradrenergic neurons may be enhanced at the onset of stroke, and these levels may be related to some extent to the clinical state and prognosis of stroke patients.

Aged↗
PubMed1991

Digital image processing to remove blur from linear tomography of the lung.

We have studied digital image processing methods to reduce blur in linear tomography of the lung performed with the Fuji computed radiography (FCR) system. One-dimensional unsharp (blur) mask filtering in the direction of tomographic movement was found to be effective in reducing blur. The appearance of the processed tomograms varied depending largely on the properties of the unsharp mask filters applied. With regard to the spatial frequency response of the filter, a high mid-frequency response and a low low-frequency response of the tomographic image data was most effective in obtaining high image quality tomograms. When the standard 2-dimensional unsharp mask technique of the FCR system was additionally applied to the one-dimensional unsharp mask processed tomogram, the clarity of the tomogram was further enhanced. These observations may also be helpful when considering image processing to obtain diagnostically informative digital radiography.

Humans↗
PubMed1990

[Intraoral ultrasound of the tongue tumor].

Transcutaneous ultrasonography scanned through the submandibular triangle has been effectively utilized for the evaluation of tongue tumors. However, because of lacking an appropriate sonic window, tumors located in the anterior portion of the tongue can not be demonstrated on the transcutaneous ultrasonogram. Intraoral ultrasonography using an echoendoscopy was effective for evaluating neoplasms of the tongue, and could clearly demonstrate tongue tumors, which failed to be shown on the transcutaneous ultrasonograms. In addition, intraoral ultrasonograms could provide more accurate anatomical informations concerning the tumor extent than the transcutaneous ultrasonograms.

Endoscopy↗
PubMed1990

Isolation and characterization of three distinct 34 kDa EDTA-extractable proteins from bovine lens.

EDTA-extractable protein (EEP) is known to be a major lens membrane protein with a molecular mass in the range 32 kDa to 38 kDa, and is also known to bind to the lens membrane and phospholipid-containing liposomes in a calcium-dependent manner. Recent results (Russell, P., Zelenka, P., Martensen, J., and Reid, T.W. (1977) Curr. Eye Res. 6, 533-538) on antibody cross-reactivity have demonstrated that a 34-35 kDa component of EEP is identical to calpactin I (lipocortin II). In this study, we have identified and purified three distinct 34 kDa components of EEP (designated as EEP-34A1, EEP-34A2 and EEP-34B) from bovine lens that inhibit phospholipase A2 activity. These proteins bind to phospholipid-containing liposome and F-actin in a calcium-dependent fashion. Two-dimensional electrophoresis demonstrates that the three proteins were distinct from one another. However, immunochemical studies and one-dimensional peptide mapping indicate that EEP-34A1 and EEP-34B are very similar. Our results also indicate that EEP-34A1 is very similar to calpactin II and that EEP-34A2 corresponds to calpactin I. The bovine lens 34-35 kDa component of EEP is a mixture of proteins rather than a single protein.

Actins↗
PubMed1990

Identification of the 32 kDa components of bovine lens EDTA-extractable protein as endonexins I and II.

EDTA-extractable protein (EEP) is a mixture of major lens membrane proteins with molecular masses ranging from 32 kDa to 40 kDa. These bind to the lens membrane in a Ca2(+)-dependent manner. In the present study we have identified and purified two distinct 32 kDa components of EEP (designated as EEP 32-1 and EEP 32-2) from bovine lens that inhibit phospholipase A2 activity. Both EEP 32-1 and EEP 32-2 bind to phospholipid-containing liposomes and actin filaments in a Ca2(+)-dependent fashion. Immunochemical studies and two-dimensional electrophoreses demonstrate that the two proteins are distinct from one another. Both EEP 32-1 and EEP 32-2 are clearly different from calpactin (lipocortin) or its proteolytic fragments because they did not react with anti-[human placenta calpactin (lipocortin)] antibody. Our results also indicate that EEP 32-1 is very similar to endonexin I and that EEP 32-2 corresponds to endonexin II.

Actins↗
PubMed1990

High resolution ultrasound of the chest wall.

To study the detailed normal ultrasonic anatomy of the pleura and chest wall, high resolution (7.5 MHz) ultrasonograms were obtained from cadaver chest wall specimens and compared with thin section computed tomograms and anatomical specimens. Ultrasonograms show three layers of the intercostal muscles (internal, external and innermost), covered by the "echogenic pleural line." The "echogenic pleural line" is caused by composite echoes from the inner parietal pleura, and the outer endothoracic fascia, with the fatty tissue covering both sides of the fascia, which are located deep to the chest wall muscles. On ultrasonograms, the subpleural fat tissue, when abundant, appeared as an apron-like structure hanging down from the inner surface of the rib (subpleural fat pad), or diffuse fat accumulation mimicking the pleural thickening.

Humans↗
PubMed1990

[Leuko-araiosis--regional cerebral hemodynamics].

To investigate the cerebral hemodynamics of leuko-araisosis (L-A), we made SPECT measurement of regional cerebral blood flow (rCBF) in 31 patients with L-A. Cerebral vascular reactivity to carbon dioxide and blood pressure was studied. Changes in rCBF during sleep were also studied. SPECT measurements of rCBF were made using radioactive tracer I-123-iodoamphetamine and Tc-99m-HMPAO. Regional CBF was reduced in patients with L-A in the white matter and in the frontal and the parietal cortex. Cerebrovascular CO2 reactivity was impaired in the white matter but was preserved in the frontal and parietal cortex. Cerebral blood flow autoregulation was impaired in the frontal cortex and in the parietal cortex. During sleep (stage 2-3) rCBF was reduced most markedly in the frontal and in the parietal cortex. Blood pressure was also reduced during sleep suggesting that the reduction of rCBF in L-A was partly due to dys-autoregulation.

Blood Pressure↗
PubMed1989

Cerebral blood flow and cerebral hematocrit in patients with cerebral ischemia measured by single-photon emission computed tomography.

Single-photon emission computed tomography (SPECT) was used for the measurement of regional cerebral blood flow (CBF), cerebral blood volume (CBV) and cerebral hematocrit (Hct). CBF was measured using N-isopropyl-p-I-123-Iodoamphetamine. CBV was measured by both RBC tracer (Tc-99m RBC) and plasma tracer (Tc-99m human serum albumin) and cerebral hematocrit (Hct) was calculated. In normals, the cerebral-to-large vessel Hct ratio was 75.9%. Isovolemic hemodilution in patients with high Hct tended to increase the cerebral-to-large vessel Hct ratio. Low CBF, high CBV and slow cerebral blood mean transit time (MTT by dynamic CT scanning) was seen during the acute stage of completed infarction and during the symptom-free interval of TIA. Cerebral Hct was increased in the ischemic region of poor prognosis.

Adult↗
PubMed1989

[Dynamic local cerebral circulation study in patients with cerebral diseases--using 99mTc-HSA-D mainly compared with 99mTc-HSA].

We have been using 99mTc-RBC and 99mTc-HSA for cerebral angiography and measurement of the local cerebral blood volume (LCBV) and cerebral/peripheral hematocrit ratio (alpha). 99mTc-HSA, however, has a problem of poor stability in the blood. We conducted basic and clinical studies on 99mTc-HSA-D, a ready-to-use preparation with good stability in the blood. We measured the regional cerebral circulation dynamics in patients with cerebral diseases in comparison with 99mTc-RBC and 99mTc-HSA. 99mTc-HSA-D and 99mTc-RBC showed more than a 90% retention ratio in the blood 60 min after administration, and good SPECT images were obtained using these two pharmaceuticals. On the contrary, 99mTc-HSA was unstable and its retention ratio was 60s% 60 min after administration. 99mTc-HSA does not provide good SPECT images due to free 99mTcO4- which seems to be liberated from 99mTc-HSA in the body, etc. There were no adverse reactions or abnormal laboratory findings caused by the 99mTc-HSA-D administration in any of the patients. Based on these results, it is surmised that 99mTc-HSA-D is clinically useful for measurement of the cerebral blood volume and cerebral/peripheral hematocrit ratio (alpha).

Adult↗
PubMed1988

Imaging local cerebral blood flow by Xenon-enhanced computed tomography--technical optimization procedures.

Methods are described for non-invasive, computer-assisted serial scanning throughout the human brain during eight minutes of inhalation of 27%-30% Xenon gas in order to measure local cerebral blood flow (LCBF). Optimized Xenon-enhanced computed tomography (XeCT) was achieved by 5-second scanning at one-minute intervals utilizing a state-of-the-art CT scanner and rapid delivery of Xenon gas via a face mask. Values for local brain-blood partition coefficients (L lambda) measured in vivo were utilized to calculate LCBF values. Previous methods assumed L lambda values to be normal, introducing the risk of systematic errors, because L lambda values differ throughout normal brain and may be altered by disease. Color-coded maps of L lambda and LCBF values were formatted directly onto CT images for exact correlation of function with anatomic and pathologic observations (spatial resolution: 26.5 cubic mm). Results were compared among eight normal volunteers, aged between 50 and 88 years. Mean cortical gray matter blood flow was 46.3 +/- 7.7, for subcortical gray matter was 50.3 +/- 13.2 and for white matter was 18.8 +/- 3.2. Modern CT scanners provide stability, improved signal to noise ratio and minimal radiation scatter. Combining these advantages with rapid Xenon saturation of the blood provides correlations of L lambda and LCBF with images of normal and abnormal brain in a safe, useful and non-invasive manner.

Aged↗
PubMed1988

Regional cerebral blood flow during an attack of vertebrobasilar insufficiency.

Using technetium-99m-labeled hexamethylpropyleneamineoxime [( 99mTc]HM-PAO) and single-photon emission computed tomography, we measured changes in regional cerebral blood flow in a 58-year-old man during an attack of vertebrobasilar insufficiency. Angiography demonstrated compression of the left vertebral artery by the osteophytes of cervical spondylosis when the patient turned his head to the left. Measured in the orthostatic position while turning his head to the left during a typical attack of vertebrobasilar insufficiency, regional cerebral blood flow was significantly reduced in the left cerebellum and the right occipital region. Our study illustrates the capability of [99mTc]HM-PAO single-photon emission computed tomography to measure transient reductions in regional cerebral blood flow and to relate these changes to the pathophysiology of vertebrobasilar insufficiency.

Cerebral Angiography↗
PubMed1988

Treatment of acute cerebral infarction with a choline precursor in a multicenter double-blind placebo-controlled study.

A multicenter double-blind placebo-controlled study of cytidine 5'-diphosphocholine (CDP-choline) was conducted to evaluate possible clinical benefits of the drug in patients with acute, moderate to severe cerebral infarction. The patients included also suffered from moderate to mild disturbances of consciousness, and all were admitted within 14 days of the ictus. Patients were allocated randomly to treatment with either CDP-choline (1,000 mg/day i.v. once daily for 14 days) or with placebo (physiological saline). One hundred thirty-three patients received CDP-choline treatment, and 139 received placebo. The group treated with CDP-choline showed significant improvements in level of consciousness compared with the placebo-treated group, and CDP-choline was an entirely safe treatment.

Acute Disease↗
PubMed1988

The number and size of normal mediastinal lymph nodes: a postmortem study.

For the CT diagnosis of pathologically enlarged nodes, information concerning the size of normal nodes is required. We studied 40 adult cadavers and determined the number and size of normal lymph nodes for each region of the mediastinum, counting all nodes and directly measuring the short and long diameters of each in the transverse plane of the node. The location of each node was classified according to the American Thoracic Society system, and the range and standard maximum sizes of normal lymph nodes in each location were determined. Nodes were found in 90-100% of cadavers in regions 4, 7, and 10; and in 68-85% of cadavers in regions 2 and 6. The average number of lymph nodes found was 3.5-4.8 in regions 4, 6, and 10R; 2.1-2.9 in regions 2, 7, and 10L; and 0.1-1.2 in all other regions. The mean short transverse diameters ranged from 2.4 to 5.6 mm, and the mean long transverse diameters ranged from 3.9 to 10.0 mm. The largest mean short and long transverse diameters were found in region 7, the next largest were in region 10R, followed by regions 4, 5, and 10L. We noted a different maximum normal size of lymph nodes in each region of the mediastinum. The short transverse diameter, which showed a smaller variation, appeared to be a more useful parameter than the long transverse diameter. We propose a standard for maximum normal short transverse diameters for nodes in each region of the mediastinum as follows: 12 mm for nodes in region 7; 10 mm for nodes in regions 4 and 10R; and 8 mm for nodes in other regions. The maximum long transverse diameters showed a wider variation, ranging from 25 to 10 mm.

Female↗
PubMed1988

Ultrasonic evaluation of cervical metastatic lymphadenopathy.

We investigated the location, size, and shape of cervical lymph nodes in head and neck cancer, using a 7.5-MHz ultrasound scanner. First, the different criteria for normal size were obtained for cervical lymph nodes in each region; lymph nodes greater than 9 mm in thickness in the internal jugular chain or greater than 7 mm in thickness in the submandibular and submental chains should be suspected of harboring metastatic foci. Second, metastatic nodes showed a more rounded configuration than nonmetastatic ones. Third, a comparative study of metastatic lymph nodes between the in vivo and in vitro ultrasonograms and the corresponding histopathological findings disclosed that an echogenic region in an ultrasonogram of a metastatic node was caused by coagulation necrosis, and a cystic area of liquefaction necrosis.

Carcinoma, Squamous Cell↗