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Biomedical subjects

T Asanuma

Publications and source records attributed to T Asanuma.

At least 37 records · Page 2Linked to original sources
PubMed1996

Doppler estimation of pulmonary artery end-diastolic pressure using contrast enhancement of pulmonary regurgitant signals.

Pulmonary artery (PA) end-diastolic pressure is used as an estimate of PA wedge pressure. We evaluated contrast enhanced pulmonary regurgitant signals in the assessment of PA end-diastolic pressure in 24 patients in a critical care unit. Right atrial pressure was estimated by the percent decrease of the inferior vena caval diameter with inspiration. Weak or absent pulmonary regurgitant signals were enhanced by sonicated albumin (Albunex) in 23 patients (96%). The Doppler-determined PA end-diastolic pressure (the sum of the pulmonary regurgitant pressure gradient at end-diastole and the right atrial pressure) was significantly correlated with the catheter-determined PA end-diastolic pressure (y = 0.85x + 1.72, r = 0.93). Compared with invasive hemodynamic monitoring, the contrast-enhanced Doppler technique using Albunex is effective for measuring PA end-diastolic pressure, even in critically ill patients.

Aged↗
PubMed1996

Intravascular ultrasound evidence of angiographically undetected left main coronary artery disease and associated trauma during interventional procedures.

To determine the clinical significance of angiographically undetected left main coronary artery (LMCA) disease, we analyzed data from 47 patients, with a mean age of 58 years, who were examined with intravascular ultrasound (3.5 Fr, 30 MHz). For assessment of atherosclerosis, the lesion area was calculated from the ultrasound images of the formula, [(total vessel area--lumen area)/total vessel areas] x 100(%). In 37 LMCA segments of patients with significant distal coronary stenosis (> 50%), the percent intima-media area (the index) was 39 +/- 11% (mean +/- SD), significantly greater than that of 10 patients without distal disease (27 +/- 4%, P < 0.01). Among those with significant coronary stenosis, the index was markedly greater in patients with multi-vessel coronary stenosis (46 +/- 12%, n = 19) than in patients with single-vessel disease (33 +/- 9%, n = 18; P < 0.01). At three LMCA sites associated with multi-vessel disease, ultrasound analysis demonstrated disruption of the intima at the site where the guiding catheter for balloon angioplasty had been positioned. These results indicate that LMCA disease is more prominent in patients with multi-vessel distal coronary disease than in those with single vessel disease, even in the absence of angiographic stenosis. We suggest that LMCA trauma can occur where the guiding catheter for angioplasty is positioned, particularly in patients with multi-vessel distal disease.

Adult↗
PubMed1996

The effects of alpha-phenyl-tert-butyl nitrone (PBN) on copper-induced rat fulminant hepatitis with jaundice.

In the present study we demonstrated the protective effects of the spin-trapping agent alpha-phenyl-tert-butyl nitrone (PBN) against fulminant hepatitis with jaundice in LEC rats. In LEC rats an excess amount of copper is accumulated in the liver and causes hepatitis with severe jaundice. PBN was subcutaneously administered every 2 d at the concentration of 128 mg/kg, beginning with 13-week-old rats and continuing for 17 weeks. PBN prevented the loss of body weight, reduced death rate, and suppressed the increase in GTP and GOT values reflecting hepatic cell destruction. Ocular inspection also confirmed the suppressive effects of PBN on jaundice. In parallel with these phenomena, the amounts of thiobarbituric acid-reactive substances (TBARS) in livers of PBN-administered rats were found to be lower than those of non-PBN-administered rats. Little histological changes were observed in PBN-administered rats in comparison with non-PBN-administered rats. The protective effect of PBN on the formation of oxidative damage in liver DNA was observed but not so remarkable as that on lipid peroxidation. From these results, it was concluded that PBN had the liver-protective effects against fulminant hepatitis with jaundice. This suggested that free radicals play an important role in abnormally accumulated copper-induced liver injury and that PBN potentially has therapeutic value for the treatment of hepatitis.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1995

The suppression of age-related accumulation of lipid peroxides in rat brain by administration of Rooibos tea (Aspalathus linearis).

The protective effects of Rooibos tea (RT), Aspalathus linearis, against damage to the central nervous system (CNS) accompanying aging were examined by both the thiobarbituric acid reaction (TBA) and magnetic resonance imaging (MRI) methods in brains of chronically RT-treated rats. Ad libitum administration of RT was begun with 3-month-old Wistar female rats and continued for 21 months. The contents of TBA reactive substances (TBARS) in the frontal cortex, occipital cortex, hippocampus and cerebellum in 24-month-old rats after administration with water were significantly higher than those in young rats (5 weeks old). However, no significant increase of TBARS was observed in RT-administered aged rats. When MR images of the brains of 24-month-old rats with and without RT as well as 5-week-old rats were taken, a decrease of the signal intensity was observed in the cerebral cortex, hippocampus and cerebellum in MR images of aged rats without RT, whereas little change of the signal intensity was observed in MR images of the same regions of 24-month-old rats treated with RT, whose images were similar to those of young rats. These observations suggested that (1) the age-related accumulation of lipid peroxides in the brain was closely related to the morphological changes observed by MRI, and (2) chronic RT-administration prevented age-related accumulation of lipid peroxides in several regions of rat brain.

Administration, Oral↗
PubMed1994

Effects of supine and lateral recumbent positions on pulmonary venous flow in healthy subjects evaluated by transesophageal Doppler echocardiography.

OBJECTIVES: This study attempted to evaluate the effects of supine and lateral recumbent positions on pulmonary venous flow by transesophageal Doppler echocardiography in healthy subjects. BACKGROUND: Although transesophageal echocardiographic examination is usually performed with the patient lying in the left lateral decubitus or supine position, little attention has been paid to the effects of these positions on pulmonary venous flow. METHODS: We performed pulsed Doppler transesophageal echocardiography of the left and right pulmonary veins in 16 normal subjects as they lay in the left and right lateral decubitus and supine positions. RESULTS: Data are reported as mean value +/- SD. Adequate recordings were obtained in 12 subjects (75%). In the left pulmonary vein, peak systolic velocity and time-velocity integral of systolic flow increased significantly in the left compared with the right lateral decubitus position (56 +/- 12 vs. 44 +/- 13 cm/s, p < 0.05, and 15 +/- 4 vs. 9 +/- 4 cm, p < 0.05, respectively). In the right pulmonary vein, peak systolic velocity and time-velocity integral of systolic flow decreased significantly in the left compared with the right lateral decubitus position (38 +/- 10 vs. 48 +/- 9 cm/s, p < 0.05, and 9 +/- 2 vs. 12 +/- 2 cm, p < 0.05, respectively). There were no significant differences between positions in peak diastolic flow velocity, time-velocity integral of diastolic flow or peak velocity of flow reversal at atrial contraction. CONCLUSIONS: Pulmonary venous systolic peak velocities and time-velocity integrals of systolic flow increase when the pulmonary venous recording is from the recumbent subject's lower side. Therefore, the effects of position should be considered in evaluating left ventricular diastolic function by transesophageal Doppler echocardiography.

Adult↗
PubMed1994

Magnetic resonance imaging of young and aged rat brains under a magnetic field of 7.05 T.

Using a homemade MR imaging probe (Helmoholtz coil), MR images of brains of 5-week-old and 23- or 24-month-old Wistar rats were taken under a magnetic field of 7.05 T (Tesla). The probe was designed to fit the rat head and made by winding thin copper film round an acrylic tube with a 5-cm i.d., 10-cm length and 2-mm thickness. This was adjusted to resonate with the 300 MHz radiofrequency corresponding to the resonance frequency of 1H under a magnetic field of 7.05 T. MR images were obtained by T1-weighted and two-dimensional Fourier transformation techniques. The sagittal and coronal sections were imaged in 1-mm-thick slices. The size of the data matrix was 128 phase-encoded steps. Each image was obtained through eight acquisitions. A comparison of the MR images with those semi-microscopically taken at the same position of the coronal section revealed that the cerebral cortex, hippocampus, hypothalamus and thalamus were clearly imaged by this probe. With aging, MR images of cerebral cortices were observed with decreased signal intensities. Enlargement of the third ventricles and hypertrophy of cranical parietal bones were also recognized in sagittal MR images of aged rats. These observations were more marked in males than in females. From these observations it was concluded that this probe was applicable for MR imaging of rat brains under a magnetic field of 7.05 T.

Aging↗
PubMed1988

[Endoscopic resection with local injection of hypertonic saline epinephrine for the treatment of early gastric cancer].

We have developed a new method of endoscopic resection of early gastric carcinomas and other tumors. Characteristics of the new method are summarized as follows. 1. In order to prevent bleeding after endoscopic resection of the tumors, local injection of hypertonic saline epine phrine (HSE) solution was applied to the lesion. Even a depressed lesion like II c type early gastric carcinoma was artificially protruded by local injection of HSE solution. 2. Instead of a single fiberscope, double fiberscopes were employed simultaneously for endoscopic resection of the lesion. 3. Prior to resection of the lesion by high frequency current snare method, incision of the mucosa along the marking line around the lesion performed, enabling the area to be resected precisely. 4. Because tissue damage is mild, resected materials removed are suitable for pathological study. Endoscopic resection was performed on a total of 113 cases in early gastric carcinomas; 103 cases among them (91.2%) were curative resections. Ten cases of the rest underwent surgical gastrectomy for the endoscopic non-curative resections. Rate of five-year survival in 103 cases was 85.2%. Endoscopic resection by our method seems to be effective for the treatment of early gastric carcinomas in any lymph node metastasis and in patients at high surgical risk.

Epinephrine↗
PubMed1988

[Hemostatic effect of an endoscopic local injection of hypertonic saline-epinephrine (HS-E) solution on upper gastrointestinal bleeding--comparative study of this effect with and without visible vessel detection].

One hundred and ninety seven patients with upper gastrointestinal bleeding were each administered and endoscopic local injection of hypertonic saline epinephrine (HS-E) solution at our hospital over a 5-year period, from the Spring of 1981 to March of 1986. Peptic ulcers were found in 162 of the patient. Vessels could be visibly detected in the 148 (91.4%)-A group, but not in the 14 (8.6%)-B group. A comparison of the number of endoscopic local injections to each of these groups indicated no significant differences in types of bleeding, systemic complications, or sites of bleeding. The excellent hemostatic effect of HS-E is due to the fact that local injection of its solution can be repeated in large quantities for various types of bleeding.

Adolescent↗
PubMed1979

A new HLA-B antigen (HOK-1) found in the Japanese.

The HLA-B8 antigen is one of the characteristic antigens associated with organ specific autoimmune diseases among Caucasians. Among the Japanese, HLA-B8 positives have been assumed to be extremely rare. By using some HLA-B8 typing sera, a new HLA-B antigen, HLA-Bw4 positive, was found in the Japanese. This new HLA-B antigen, tentatively called HOK-1, showed a phenotype frequency of 3.7% and a gene frequency of 1.9 +/- 0.6%. This antigen has a strong linkage disequilibrium with HLA-Cw1 among the Japanese.

Chromosome Mapping↗