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Biomedical subjects

K Teramoto

Publications and source records attributed to K Teramoto.

At least 55 records · Page 3Linked to original sources
PubMed1996

Analysis of connective tissue macromolecular components in Ishibashi rat skin: role of collagen and elastin in cutaneous aging.

The Ishibashi (IS) rat, established from cross-breeding between Wistar and wild rats, has a unique skin appearance, with wrinklings and furrows indicative of skin aging appearing at the age of 12 weeks. To understand the underlying mechanism of the formation of wrinkles, macromolecular components of connective tissue, collagen and elastin, in the young (5-6-week-old) and the aged (23-30-week-old) IS rat skins were biochemically analyzed. Hydroxyproline and isodesmosine contents in the aged IS rats were reduced 22% (P < 0.05) and 37% (P < 0.05) compared to the young rats, whereas no significant differences in the contents of both macromolecules in control Sprague-Dawley (SD) rats were seen. The relative content of type III collagen was unaltered between the young and aged skins of both IS and SD rats. A relative decrease in the intact elastin molecule (65 kDa) and a relative increase in the elastin fragments with lower molecular weights were observed in the aged IS rat skin by immunoblotting method. These results indicate that the reduction in collagen and elastin contents and increased degradation of elastin molecules in the aged IS rat skin could be related to the formation of wrinkles. Thus, the IS rat may provide a useful model for the study of skin aging.

Aging↗
PubMed1996

Antimicrobial activities of iodinated polystyrene derivatives.

The antimicrobial activities of insoluble halogenated acetamidomethy1-styrene polymers (prepared by covalent bonding of iodine to polystyrene) were assessed as were the factors determining antimicrobial efficacy. The most active materials were selected from chlorinated or iodinated polymers. Antimicrobial activities were assessed for Escherichia coli (ATCC 25922; American Type Culture Collection, Rockville, MD, U.S.A.), Saccharomyces cerevisiae, and Candida albicans by determining time-course changes in microbial counts in vitro. A 2-iodoacetamidomethylstyrene polymer (No.6-I:-CH2I) was found to have the greatest antimicrobial activity against both bacteria and fungi. No.6-I is the first antimicrobial material that did not make an inhibition hollow in the conventional diffusion test or for which conjugated iodine showed antibacterial activity. This material can be introduced into styrene units on the surface of devices by chemical modification. This material was most active at 37 degrees C. For coated dishes, antimicrobial activity depended on the depth or swollen character of the reactive layer. NO.6-I requires not only a minimum width of polymer layer, but also frequent contact with microbes to have an antimicrobial effect. No.6-I is valuable as a new material because it has strong antimicrobial activity by itself but does not release active iodine. This material is expected to have various applications in implantable clinical devices.

Anti-Infective Agents, Local↗
PubMed1996

Changes in body weight and organ weight of Ishibashi (IS) rats with growth.

Changes in body weight (25-175 days old, every 10 days) and weights of various organs (70, 105, 140 and 175 days old), i.e., cerebrum, cerebellum, pituitary gland, thyroid gland, thymus, heart, liver, spleen, adrenal gland, kidney, seminal vesicle, prostate, epididymis, testes, bulbourethral gland and ovary, of Ishibashi (IS) rats with growth, which are model animals for congenital vertebral malformation (spontaneous kyphoscoliosis) were examined as compared with Brown Norway (BN) rats, which are genetically irrelevant to IS rats, and also with hybrid rats (IBF, rats) which are between IS and BN rats. The experimental results showed that body weight and weights of various organs except cerebrum, cerebellum and thymus were greater in IS rats than in BN rats, and body weight and weights of various organs of IBF, rats were intermediate between the two strains of rats.

Animals↗
PubMed1996

Predicting risk of embolization during anticoagulation for left atrial thrombus by transesophageal echocardiography: a case report.

A 75-year-old woman was admitted with transient left hemiparesis accompanied by diminished level of consciousness in September 1994. Holter electrocardiography showed transient atrial fibrillation, and transesophageal echocardiography (TEE) revealed an atrial septal aneurysm, spontaneous echo contrast, and a thrombus in the left atrial appendage. The patient received anticoagulant treatment with warfarin, and follow-up TEE showed thrombus resolution. However, after the warfarin was discontinued, symptoms recurred in October 1995 and TEE showed a club-like left atrial thrombus (21 x 40 mm) originating in the left atrial appendage and extending to the center of the left atrium. Follow-up TEE after warfarin therapy showed resolution at the neck of the thrombus but the head threatened detachment. The thrombus was subsequently excised surgically. Follow-up TEE was critical for detecting the risk of significant embolization during anticoagulant therapy.

Aged↗
PubMed1995

Regional distribution of superoxide dismutase in the brain and myocardium of the stroke-prone spontaneously hypertensive rat.

1. Enzyme activities and contents of manganese and copper-zinc superoxide dismutase (Mn-, Cu/Zn-SOD) and oxygen free-radical scavengers were determined in the myocardium (right, left ventricle) and brain (cerebral cortex, hippocampus) of 15 and 31 week old stroke-prone spontaneously hypertensive rats (SHRSP). 2. In 15 week old SHRSP myocardium, both Mn- and Cu/Zn-SOD activities were higher but in 31 week old SHRSP, these were lower than that in Wistar-Kyoto (WKY) rats. Further, correlation between Mn-SOD content and activity in 31 week old SHRSP myocardium showed that specific activity was lower than that in WKY. 3. In 15 and 31 week old SHRSP cerebral cortex and hippocampus, SOD content and activity showed a tendency to be lower than that in WKY. 4. These results indicate that enzymatically inactive or low-active Mn-SOD protein exists in SHRSP myocardium, and that the alteration of SOD may be one of the causative factors for the vulnerability of the myocardium and brain against O2-radicals.

Animals↗
PubMed1995

Biochemical characteristics of lungs in senescence-accelerated mouse (SAM).

This study examined age-related biochemical changes of the lung in an animal model of senile lung, senescence-accelerated mouse (SAM). Bronchoalveolar lavage (BAL) was performed on two strains of SAM, the senescence-prone strain (SAM P2) and the senescence-resistant strain (SAM R1), as well as on normal ageing C57 black mice (C57BL), aged 1-24 months. Elastase-like and elastase inhibitory activity of BAL fluid (BALF), glutathione (GSH) and oxidized GSH (GSSG) content both of BALF and lung tissue, and oxygen radical generation of free lung cells obtained by BAL were examined in the three strains of mice. Cell populations did not change throughout the life in SAM strains and C57BL. The elastolytic activity in SAM was greater than in C57BL, but there was no change with age. Both a decreased content of GSH and an increased oxidation of the GSH in BALF were markedly observed with ageing in SAM P2. In the lung tissue, the GSSG/GSH ratio in SAM strains was consistently greater than that in C57BL, suggesting that the GSH redox cycle of the lung may be impaired in SAM strains. The oxygen radical generation by free lung cells increased with age in all three strains, but the increase was earlier and more pronounced in SAM P2 than in the other two strains. In conclusion, an impaired GSH redox cycle and an increased formation of oxygen radicals are observed in the lungs of SAM with increasing age.

Aging↗
PubMed1994

Biological monitoring of exposure to low concentrations of styrene.

A field study was conducted on 39 male workers exposed to styrene at concentrations below 40 ppm (time weighted average, TWA). Analyses were carried out on environmental air, exhaled air, blood, urine, and two major urinary metabolites of styrene: mandelic acid (MA) and phenylglycoxylic acid (PGA). Head space gas chromatography (GC) with a flame ionization detector (FID) was used for determination of styrene in blood and urine. Postexposure exhaled air was analyzed using capillary GC. Environmental styrene exposure was measured by personal sampling using carbon cloth personal samplers. Urinary metabolites of styrene were determined by high pressure liquid chromatograph (HPLC). When the end-of-shift breath, blood, and urine styrene levels were compared with environmental TWA values, blood styrene correlated best with styrene in air (r = 0.87), followed by breath styrene (r = 0.76). Poor correlation (r = 0.24) was observed between environmental styrene exposure and urine styrene. When styrene metabolites were compared with environmental styrene, the sum of urinary MA and PGA correlated better with styrene in air than MA or PGA alone. The correlations between urinary metabolites and environmental styrene improved when corrected for the specific gravity of urine. Even better correlations were observed when the urinary metabolites were corrected for creatinine. The correlation coefficients for environmental styrene and end-of-shift MA, PGA, and MA+PGA were 0.83, 0.84, and 0.86, respectively. The correlation coefficients between environmental styrene and next morning urinary metabolites fell to 0.47, 0.61, and 0.65 for MA, PGA, and MA+PGA, respectively. These results suggest that determination of the total MA and PGA in urine samples is preferred than separate measurements of MA or PGA. The good correlation between environmental exposure and styrene in the exhaled air also suggests that breath styrene level can be a useful indicator for low level styrene exposure, as the method is specific, noninvasive, and rapid. Urinary styrene seems to be a less reliable indicator for low level styrene exposure.

Adult↗
PubMed1994

31P NMR assessment of orthotopic liver rejection in a rat model.

31P NMR spectroscopy was used serially to study rejecting (ACl-->LEW) and nonrejecting (ACl-->ACl) orthotopic liver transplants in rats. Recipients were evaluated on post-transplant days 1, 3, 5, 7, 9, and 11. The relative changes in phosphomonoester (PME), inorganic phosphate (Pi), high-energy phosphates and pH were studied. The earliest significant difference between the rejecting and nonrejecting groups was a decrease in the alpha-NTP peak area on Day 5. This was followed by significant decreases in beta-NTP and pH, and increases in PME and Pi on Day 7. High-resolution 31P NMR spectra of perchloric acid extracts demonstrated the PME increase to be due mainly to elevated phosphoethanolamine. Using the parameter (Pi + PME)/(alpha + beta + gamma-NTP), rejecting livers were distinguished from nonrejecting livers at a moderate stage of rejection.

Animals↗
PubMed1994

Age-related changes in the antioxidant screen of the distal lung in mice.

We studied the influence of age on glutathione (GSH) content in the distal lung and the lung tissue of mice. From 1 to 28 months of age, the quantity of GSH and glutathione disulfide (GSSG) in bronchoalveolar lavage (BAL) fluid and in the lung tissue were determined. The GSH content in BAL fluid, which reflects the antioxidant screen of the distal lung, decreased with advancing age. The ratio of GSSG to GSH increased in later life, suggesting increase of oxidation of the epithelial lining fluid in old mice. The GSH content in the lung tissue also decreased with aging. Therefore the lower respiratory tract may be less able to defend against external attack, including attack by oxygen-derived active molecules, in senescent mice. The decrease of the antioxidant screen of the distal lung may be associated with impaired lung defense in relation to oxidant-antioxidant balance in aged mice.

Aging↗
PubMed1994

Use of the visual suppression test using post-rotatory nystagmus to determine skill in ballet dancers.

Twelve ballet dancers with various levels of dancing experience and skill were examined with the visual suppression test using post-rotatory nystagmus (PRVST) and caloric stimulation (CVST). The PRVST results showed a suppression rate that was higher than in untrained subjects. The CVST results showed a suppression rate similar to that in untrained subjects. A correlation between the PRVST and CVST suppression rates and the length of dancing experience showed that the suppression rate increased as the level of experience and skill rose. These results indicate that the PRVST and CVST can aid in the clinical and quantitative assessment of the function of the central nervous system in visual-vestibular interactions in ballet dancers. Additionally, testing may have determined function of vestibulo-cerebellar pathways through habituation of visual-vestibular interactions. Findings indicate that it may be possible to use suppression rates of PRVST and CVST to determine the approximate level of a dancer's experience and skill.

Adult↗
PubMed1994

A novel model of senile lung: senescence-accelerated mouse (SAM).

Senescence-accelerated mouse (SAM) has been characterized as a unique animal model to investigate spontaneous aging as well as age-related disorders. However, little is known about the properties of the lung. We examined age-related morphologic and functional changes of the lung in SAM P2, as the senescence-prone strain, and in SAM R1, as the senescence-resistant strain. On morphologic examination, the earlier (starting at 6 mo) and more severe change in airspace size (mean linear intercept: MLI) was observed in SAM P2 (MLI [micron]; 3 mo: 72.1 +/- 2.4; 6 mo: 80.8 +/- 2.9; 12 mo: 91.1 +/- 3.1; 18 mo: 143.4 +/- 6.6), compared with SAM R1 (MLI [micron]; 3 mo: 68.9 +/- 1.8; 6 mo: 70.8 +/- 2.6; 12 mo: 76.1 +/- 2.8; 18 mo: 101.2 +/- 4.7). The destructive index was not remarkably changed through life in both strains, suggesting that the alveolar wall was relatively intact in SAM. On functional examination, the left-sided shift of the pressure-volume (P-V) curves observed in SAM P2 at an early stage of aging (starting at 9 mo) compared with SAM R1. The shape constant (K) obtained from the P-V curve was increased with aging in SAM P2 (K; 3 mo: 0.124 +/- 0.004; 9 mo: 0.142 +/- 0.003; 18 mo: 0.183 +/- 0.008), and also increased at a late stage of aging in SAM R1 (K; 3 mo: 0.123 +/- 0.005; 9 mo: 0.135 +/- 0.004; 18 mo: 0.148 +/- 0.007). This study demonstrates that SAM P2 manifested most of the characteristic changes in senile lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1994

Hepatic resection under the intermittent selective portal branch occlusion by balloon catheter.

BACKGROUND: In hepatic resection, it is important to control intrahepatic blood flow to minimize blood loss. Intermittent and selective vascular occlusion, if possible, are advisable. STUDY DESIGN: For this purpose, we created the double balloon catheter, which when introduced into a lobar or a smaller branch of the intrahepatic portal vein through a branch of the ileocolic vein, made it possible to occlude these branches temporarily during hepatic resection. The small balloon located at the tip of the catheter made it easy to introduce the catheter to the portal branch selectively, under the guidance of ultrasonography. Another balloon was inflated intermittently to occlude selective portal blood flow. Using this technique, hepatic resection was achieved in 18 consecutive patients: 13 with hepatocellular carcinomas (11 with cirrhosis, two with chronic hepatitis), one with cholangiocellular carcinoma, three with metastatic carcinomas, and one with intrahepatic calculi. RESULTS: In these cases, 19 hepatic resections were performed; two left hepatectomies, one extended right hepatectomy, one right hepatectomy, six segmentectomies, eight subsegmentectomies, and one partial hepatectomy. In each case, well demarcated hepatic tissue delineated by ischemic change was removed with minimal bleeding and little impairment to the residual hepatic tissue, resulting in a good postoperative course. CONCLUSIONS: This double balloon catheter can replace the dissection of the hepatoduodenal ligament for hepatic resection, which causes bleeding, especially in patients with cirrhosis, and results in less cell injury of the residual hepatic parenchyma.

Aged↗
PubMed1993

A rat fatty liver transplant model.

A rat model of fatty liver transplantation has been developed to study primary nonfunction in fatty liver grafts. ACI rats were fed with a diet deficient in choline and methionine for 7, 14, 28, and 42 days. Fat content in the pretransplant livers was examined by gas chromatography and histology. The main constituent of the fatty droplets was determined to be triglyceride. The triglyceride concentration reached a maximum by day 14 and remained constant for an additional 28 days. Histology revealed an absence of necrosis in 14- and 28-day fatty livers but scattered hepatocytic necrosis and inflammation in 42-day fatty livers. After being given cold (UW stored, 4 degrees C) or warm (37 degrees C) ischemia, the fatty liver was orthotopically transplanted into normal ACI rats. The one-week survival of fatty liver grafts after 6, 12, 18, and 24 hr cold preservation was 5/5, 5/6, 3/8, 0/6 for 14-day fatty liver and 5/5, 4/6, 0/8, 0/6 for 42-day fatty livers. The survival of normal liver grafts was 5/5, 6/6, 5/9, 2/8, respectively. Increased survival rate was correlated with the absence of hepatocytic necrosis. The survival after 15 and 30 min warm ischemia prior to transplant was 5/5, 2/6 for normal liver grafts and 4/7, 0/6 for 28-day fatty liver graft, respectively. Fatty livers were less resistant to damage induced by cold or warm ischemia.

Animals↗
PubMed1993

Hepatic microcirculatory changes after reperfusion in fatty and normal liver transplantation in the rat.

The hepatic microcirculation in fatty and normal liver grafts in ACI rats was investigated using in vivo microscopy. Six groups were studied. They were: normal and fatty control livers (sham operated), 6-hr cold University of Wisconsin solution (UW)-preserved fatty and normal liver grafts (survival conditions, fatty and normal liver grafts), 18-hr cold UW-preserved fatty livers (nonsurvival conditions, fatty liver graft), and 24-hr cold UW-preserved normal livers (nonsurvival conditions, normal liver grafts). Fatty livers in all groups were found to have narrow and irregular sinusoids with blood cell adhesions to endothelial cells. The number of adhesions increased as the preservation time increased. Sinusoidal blood flow area decreased as the preservation time increased and was correlated with survival in both normal and fatty liver grafts. The phagocytic activity of Kupffer cells (corrected for flow) increased as the preservation time increased. The phagocytic Kupffer cell activity of the 18-hr preserved fatty liver group was greater than the activity of any other group. These features may cause liver cell death and contribute to primary graft nonfunction after transplantation of a fatty liver.

Animals↗
PubMed1993

[Quality of life following liver transplantation].

247 liver transplantations in 210 patients were done between June 1983 and April 1991 in our hospital. In this paper we have analyzed our experience with adult liver transplantation from the view point of quality of life after liver transplant. Indications for liver transplantation were the following: 46 patients with cirrhosis due to non A, non B hepatitis, 29 with alcoholic cirrhosis, 13 with hepatitis B, 34 with primary biliary cirrhosis, 26 with primary sclerosing cholangitis, 29 with acute hepatic necrosis, 10 with liver tumor, 13 with miscellaneous other diseases. Of the 210 patients, 125 are alive to date. One, three and five year survival rates (excluding perioperative death) of all patients were 80.2%, 70.6% and 65.45% respectively. The best rehabilitation is in 73 patients who are full time workers or full time students and in 16 patients who are homemakers. The degree of rehabilitation in these patients is very high: 6 patients died after achieving complete rehabilitation; 11 patients retired from employment after liver transplantation; 8 patients are chronically disabled; 79 patients died before rehabilitation could be achieved. Rehabilitation rates of one and five year survivors are 78% and 84.2% respectively. Quality of life has been satisfactory following liver transplantation.

Adolescent↗
PubMed1992

A visual suppression test using post-rotatory nystagmus.

The visual suppression test is one method for examining the function of visual fixation and visual influence on vestibular nystagmus. In this study the visual suppression test using post-rotatory nystagmus was investigated in 65 normal subjects and 142 clinical cases with cerebellar lesions. In 65 normal subjects the mean +/- standard deviation of visual suppression of the slow phase velocity on post-rotatory nystagmus was 69 +/- 11%. As to the stimulation for visual suppression test, the post-rotatory method using rotatory stimulation is milder than caloric stimulation. This method is far simpler to analyze than the visual suppression test using pendular rotatory nystagmus and other vestibulo-ocular reflex tests. In the 142 patients with cerebellar lesions, reduced or abolished visual suppression on post-rotatory nystagmus was seen in 89 patients with radiologically confirmed disturbances in the vestibulo-cerebellum. And this method could identify the lesion side in the cerebellum. These results showed a correlation between the visual suppression test using post-rotatory nystagmus and one using caloric nystagmus in 65 normal subjects and 142 clinical cases with cerebellar lesions.

Caloric Tests↗