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Biomedical subjects

T Kasamatsu

Publications and source records attributed to T Kasamatsu.

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

Synergetic cytotoxicity of bleomycin and polyhydric alcohols: DNA strand breakage evaluated by "comet assay".

DNA strand breakage induced in cultured cells by bleomycin (BLM) was remarkably enhanced in the presence of glycerol or polyvinyl alcohol which produces an enhancement effect on BLM cytotoxicity, but not in the presence of alcohols such as methanol, ethanol, or polyethylene glycol which do not produce enhanced cytotoxicity. The comet assay, a useful analytical method for evaluating DNA strand breakage, clearly demonstrated that combinations of BLM and polyhydric alcohols induced serious DNA damage in the whole cell populations compared with those induced by treatment with BLM alone. The comet assay also successfully showed distributions of cell populations with various degrees of DNA damage. These results suggested that an increase in DNA damage induced in the presence of polyhydric alcohols might be responsible for the enhancement of BLM cytotoxicity.

Alcohols↗
PubMed1996

[A population survey on bone mineral density in a fishing village in Wakayama prefecture. (Part 1) Distribution of bone mineral density by sex and age based on a representative sample of the community].

To establish reference values for bone mineral density (BMD), a population survey was carried out in a fishing community in Wakayama Prefecture. The BMD measurements of the lumbar spine (L2-L4) and proximal femur (femoral neck, trochanter and Ward's triangle area) were performed by sex and age, using dual-energy X-ray absorptiometry. Four hundred subjects, aged 40 to 79 years, were recruited randomly to give 50 persons in each of eight age-sex strata from a list of 2,261 residents (1,028 men and 1,233 women) living in a fishing village. The validity of sampling methods was assessed using a questionnaire about lifestyle factors, which was used for all residents aged from 40 to 79 years in the baseline survey. There were no significant differences between the subjects for BMD measurements and all the residents of the community in the frequencies of past history of diseases, healthy habits, food intakes, and rates of smoking, alcohol drinking, coffee and green tea consumption. These findings suggested that the present study population could be considered representative of samples obtained from the entire population in the fishing community. The results of BMD measurements in these subjects, who were selected at random, showed that except for a slightly high BMD of the lumbar spine in men in their 60's, the mean BMD of the lumbar spine and the three proximal segments of the femur decreased with increasing age in both sexes.

Adult↗
PubMed1996

[A population survey on bone mineral density in a fishing village in Wakayama Prefecture (Part 2); The analysis of the risk factors affecting the bone mineral density].

The purpose of this study was to detect factors affecting lumbar bone mineral density (BMD) of general inhabitants in a rural community. A cohort consisting of 2261 inhabitants aged 40-79 years was set up based on the resident registration in Taiji town, Wakayama Prefecture in 1992. Fifty men and 50 women in each of four age strata (40-49, 50-59, 60-69, 70-79), totaling 400 inhabitants, were selected randomly. After completion of a questionnaire by an interviewer, items about physical characteristics such as height, body weight, wrist length and grip power were measured. Examination of BMD of the lumbar spine and proximal femur by dual energy X-ray absorptiometry was performed. Correlation coefficients between BMDs and values of physical characteristics were determined. Lumbar BMD was examined to determine whether the following factors were positive or negative: past history, alcohol consumption, smoking habit, dietary habit, exercise, and in addition, pregnancy times and menstrual status for women. Among the values of physical characteristics, body weight was the most closely correlated with lumbar BMD. The items that showed significantly high values as factors affecting lumbar BMD were a past history of diabetes mellitus (men and women in their 70s), and exercise (men in their 50s and women in their 40s). Regarding pregnancy times and menstruation, BMD in women with a history of childbirth was significantly higher than that in those without the history among the women in their 70s. Although the BMD in the women with lactation was significantly lower than that in those without it among the women in their 40s, there was no difference in BMD between the women with and without the history who were 50 years old or over. The effect of menstrual status was investigated according to years after menopause in the women in their 50s. BMD was significantly lower in the women with ar least six years after menopause than in those within five years.

Adolescent↗
PubMed1996

[A population based study on factors related to bone mineral density in Wakayama Prefecture].

For evaluation of the community health program, 1543 inhabitants aged 40-79 years were recruited as cohort members in Miyama Village, Wakayama Prefecture. In this cohort, bone mineral density (BMD) of 400 subjects, 50 males and 50 females each randomly selected from each of four age strata, was measured at the lumbar spine and femur neck by dual energy X-ray absorptiometry. Information on exposure to possible risk factors was obtained from a self-administered questionnaire. The results were as follows; BMD at the lumbar spine and femur neck in women aged 70-79 who maintained an exercise habit (> or = one hour/week) was significantly higher than women with no exercise habit. The BMD at the femur neck in men aged 60-79 with alcohol drinking habit was significantly higher than those with no drinking habit. Significant correlation was not seen between milk intake or smoking and the BMD. BMD at the femur neck in women aged 60-69 with multiple child births (> or = 4) were significantly higher than those with fewer child births. The BMD in women aged 50-59 with earlier onset of menarche was higher than those with late menarche. Significant reduction in BMD of postmenopausal women was observed compared to premenopausal women analyzed after matching for age. The result of analysis of quantification method of the first type showed that age and menopause had a marked effect on BMD. Concerning lifestyles as other factors, a positive correlation was observed between BMD and drinking for men and exercise for women. These factors appear to be useful indicators of risk for osteoporosis.

Adult↗
PubMed1995

Wide difference between the cytotoxicity of the 11-alpha-and 11-beta-cyano analogues of tilivalline and their epimeric conversion.

Tilivalline (TV) possesses a pyrrolo[1,4]benzodiazepine nucleus and is cytotoxic toward mammalian cells. The 11-beta-cyano TV analogue (1) is about one hundred times more cytotoxic to mouse leukemia L1210 cells than TV itself. In contrast, the 11-alpha-cyano TV analogue (2), an epimer of 1, has only about one-hundredth the cytotoxicity of 1. It was found that epimerization proceeded between 1 and 2 under physiological conditions, and the cytotoxicity of 2 is thought to be caused mainly by 1 that was formed from 2 during incubation in medium.

Animals↗
PubMed1995

Significance of altered fluidity of plasma membranes of the liver and kidney in rats with sepsis.

The present study was conducted to investigate changes in plasma membrane fluidity of the liver and kidney in sepsis, which is the main cause of multiple organ failure. Male Wistar rats weighing 200-250 g were used in all experiments. Sepsis was induced by cecal ligation and puncture. As a control, a sham operation was performed. The time course of plasma membrane fluidity of the liver and the renal cortex in septicemic rats or in controls was studied. To evaluate the fluidity, fluorescence polarization was measured using 1,6-diphenyl-1,3,5-hexatriene. The fluorescence polarization values of liver plasma membranes increased after cecal ligation and puncture: 0.183 +/- 0.004 (mean +/- SEM), 0.194 +/- 0.008, 0.206 +/- 0.003, and 0.210 +/- 0.002 at 0, 24, 48, and 72 hr, respectively. Corresponding values for membranes of the renal cortex increased in a similar fashion. To determine whether factors involved in cell membrane damage exist in blood, the direct effects of lipopolysaccharide (LPS), platelet-activating factor (PAF), and serum from normal rats or from septicemic rats on membrane fluidity were studied. The fluorescence polarization of plasma membranes of the liver or renal cortex to which septicemic rat serum was added was higher than that of plasma membranes to which normal rat serum was added. The fluorescence polarization of liver plasma membranes was increased by LPS, but that of plasma membranes of the renal cortex was slightly decreased. In addition, the fluorescence polarization of liver plasma membranes was increased by PAF, but that of plasma membranes of the renal cortex was decreased.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Spatially distributed responses induced by contrast reversal in cat visual cortex.

Field potentials were recorded from cat striate cortex, either between an epidural screw electrode and a cannula-electrode inserted deep in the gray matter (transcortical recording) or with a pair of metal microelectrodes. Electrodes were placed bilaterally near the cortical projection of the area centralis. The horizontal separation of the recording tips was approximately 2 mm and approximately 300 microns, respectively. The area of the visual field providing input to the recording site (receptive field) was determined by measuring the field potentials generated by contrast reversal of high-contrast, achromatic bar gratings. Five-degree-diameter grating patches were presented individually over a large area of the visual field. The gratings were contrast-reversed at 4, 6 or 10 Hz, while also being swept in spatial frequency between 0.56 and 5.24 c/deg. The receptive fields were approximately 20 deg across or more, substantially larger than expected on the basis of cortical retinotopy. Responses were also elicited by stimulation of the hemi-field contralateral to that contributing to the classical receptive field, implicating the presence of a callosal projection. The large, spatially distributed receptive fields consisted of patches of high and low sensitivity. Continuous cortical infusion of either 100 microM tetrodotoxin or 10 mM muscimol at the recording site totally suppressed the transcortically recorded field potentials, proving that the local field potentials were generated postsynaptically. The present findings suggest that a cluster of cortical cells near the projection site of the area centralis receives input from remote cortical regions to an extent that is comparable with that of anatomically demonstrated long-range lateral connections.

Animals↗
PubMed1995

Alteration in the fluorescence polarization of rat plasma and liver cell membranes following bile duct ligation in rats.

The fluorescence polarization levels of liver cell membranes and plasma were analyzed to determine membrane fluidity following bile duct ligation (BDL) in rats. Fluorescence polarization was measured with a spectrofluorophotometer equipped with polarizers, using 1,6-diphenyl-1,3,5-hexatrien (DPH) as a probe. After bile duct ligation, liver cell membrane fluidity decreased significantly for up to 14 days after surgery (P < 0.001 on 3rd and 7th days). The polarization of the plasma in rats with BDL slightly but significantly increased compared to the levels in the control animals over the 14-day period following BDL. In addition, a small but significant correlation in the polarization levels between plasma and liver cell membranes (r = 0.362, P < 0.02) was observed. The co-incubation of BDL plasma with normal liver cell membranes resulted in a decrease in membrane fluidity, which suggested that BDL rat plasma had a direct effect on membrane fluidity. After a 70% hepatectomy, the polarization of the membranes from remnant livers in the BDL rats remained elevated relative to the sham-operated controls. It is thus concluded that the membrane fluidity of the livers in BDL rats decreases following bile duct ligation and does not increase after a 70% hepatectomy, presumably due to the increased plasma level of bilirubin.

Animals↗
PubMed1995

Highly-sensitive identification of alpha-fetoprotein mRNA in circulating peripheral blood of hepatocellular carcinoma patients.

In order to capture hepatocellular carcinoma (HCC) cells in circulating peripheral blood, we made analysis to see if alpha-fetoprotein (AFP) mRNA exists in the peripheral blood obtained from patients with HCC and also, as a control, from hepatitis-viral-marker-positive patients without HCC and a healthy volunteer. As the number of HCC cells in peripheral blood and the quantity of AFP mRNA are expected to be very small, the analysis was performed by the reverse transcription followed by an original three-step polymerase chain reaction. By this highly-sensitive method, 5 of 7 HCC patients were positive for AFP mRNA. These 5 positive patients consisted of three with clinically apparent recurrence, one preoperative patient with tumor thrombus in the portal vein and one recurrence-free patient who developed clinically detectable recurrence three months after this analysis. Neither 4 patients with positive viral markers nor a healthy volunteer was positive. The results suggest that detection of AFP mRNA from HCC patients' peripheral blood by our highly-sensitive RT-PCR may be a practical and powerful tool to diagnose the preoperative spreading of HCC and to monitor its recurrence.

Adult↗
PubMed1995

Formation of amino acid precursors in cometary ice environments by cosmic radiation.

Cometary ices are believed to contain water, carbon monoxide, methane and ammonia, and are possible sites for the formation and preservation of organic compounds relating to the origin of life. Cosmic rays, together with ultraviolet light, are among the most effective energy sources for the formation of organic compounds in space. In order to study the possibility of the formation of amino acids in comets or their precursory bodies (interstellar dust grains), several types of ice mixtures made in a cryostat at 10 K ("simulated cometary ices") were irradiated with high energy protons. After irradiation, the volatile products were analyzed with a quadrupole mass spectrometer, while temperature of the cryostat was raised to room temperature. The non-volatile products remaining in the cryostat at room temperature were collected with water. They were acid-hydrolyzed, and analyzed by ion-exchange chromatography. When an ice mixture of carbon monoxide (or methane), ammonia and water was irradiated, some hydrocarbons were formed, and amino acids such as glycine and alanine were detected in the hydrolyzate. These results suggest the possible formation of "amino acid precursors" (compounds yielding amino acids after hydrolysis) in interstellar dust grains by cosmic radiation. We previously reported that amino acid precursors were formed when simulated primitive planetary atmospheres were irradiated with cosmic ray particles. It will be of great interest to compare the amount of bioorganic compounds that were formed in the primitive earth and that brought by comets to the earth.

Amino Acids↗
PubMed1995

Age-related evaluation of peripheral circulation of workers with vibration exposure.

This study was designed to clarify the age variation of the indices in the accelerated plethysmography (APG) for fingers and set the standard ageing curve. The indices of APG of workers with exposure to vibration were compared with those of the standard ageing curves. The subjects were 815 male workers, ranging in age from 18 to 66, without exposure to vibration and without history of hypertension, circulatory diseases or diabetes. Their indices of APG are used establishing the standard ageing curves. The workers occupationally exposed to hand-arm vibration were also the subjects to evaluate peripheral circulation of hand. The APG was measured on the index finger tip of his dominant side by an accelerated plethysmometer. The subjects were divided into age groups at intervals of 5 years. In all age groups from 18 to 64 years, each index of APG showed an approximately normal distribution in a logarithmic scale. The mode of the distribution shifted to a lower value with increasing age. The standard ageing curves were drawn by calculating 25th, 50th and 75th percentiles by a nonparametric method for each group. Each index of the standard ageing curves dropped with increasing age. The significant age effect was slightly marked below 30 years, but marked between 30 and 50 years. The indices of APG of workers with exposure to vibration were also compared with those of the standard ageing curve. The indices of -b/a and a/d of workers with exposure to vibration were deteriorated beyond physiological change. We established the standard ageing curves for APG for male men. The technique is good for the evaluation of peripheral circulation disorder of aged workers with occupational exposure to vibration.

Adult↗
PubMed1994

Efficacy of the Cytobrush method in aged patients.

To evaluate the efficacy of the Cytobrush method in aged patients, a comparative study between the Cytobrush smears and cotton swab smears from the uterine cervix was performed. Consecutive 319 cotton swab smears of the endocervix were attempted on aged patients (60-98 yr, average 77.5 yr) from 1987 to 1988 (A group). Subsequently 391 endocervical smears were attempted by the Cytobrush on aged patients (60-100 yr, average 76.9 yr) from 1988 to 1990 (B group). The Cytobrush method was more effective in the following two points: (1) The rate of insert-impossible case in B group (7.2%) was lower than A group (12.5%). (2) The rate of case containing endocervical columnar cells increased in B group (64.7%) compared with A group (47.7%). In contrast, benign epithelial fragments (BFs) were observed in 6.8% of A, in 28.4% of B group. In smears positive for squamous cancer, malignant epithelial fragments (MFs) were noted in 24.5% of A, and 55.1% of B group. Consequently, the differential diagnosis of MFs from BFs is of more importance on the Cytobrush smears of aged patients.

Aged↗
PubMed1994

Regeneration of norepinephrine-containing fibers in occipital cortex of adult cats.

Regeneration of norepinephrine (NE)-containing nerve fibers in occipital cortex of adult cats was studied using morphological and biochemical methods. Initially, degeneration of cortical NE fibers was induced by direct infusion of 6-hydroxydopamine (6-OHDA) for a week. Cortical reinnervation by NE fibers continuously proceeded throughout 52 weeks, the longest survival period studied, after stopping 6-OHDA infusion. The rate of the reinnervation was slower in mature cortex than that obtained earlier in immature cortex. The present results indicate that the regenerative ability of the central NE neurons is universal, not limited to the immature brain. It is implied that the central NE neurons are equipped with a transmitter-specific repair mechanism throughout life.

Animals↗
PubMed1994

Plasma membrane fluidity during regeneration and atrophy of the rat liver following portal branch ligation.

Dynamic changes in liver plasma membrane fluidity caused by regeneration and atrophy were assessed in rats following portal branch ligation (PBL). The portal branch, which perfuses 70% of the liver, was ligated with 5-0 prolene, and liver plasma membranes were isolated by ultracentrifugation. The membrane fluorescence polarization was measured as an index of membrane fluidity using 1,6-diphenyl-1,3,5-hexatriene (DPH) as the probe dye. In nonligated lobes, a significant decrease in fluorescence polarization was observed 12 and 24 h after PBL (0.171 +/- 0.004, p < 0.01 and 0.165 +/- 0.005, p < 0.001, respectively) as compared to the controls (0.181 +/- 0.002). The fluorescence polarization values then gradually returned to near control levels. In contrast, in the ligated lobes, the fluorescence polarization had increased by 12 hours after PBL (0.196 +/- 0.002, p < 0.01), and remained significantly elevated (p < 0.01) for up to 1 week after PBL, gradually returning to control levels within 3 weeks. The membrane composition was also evaluated by analyzing the cholesterol/phospholipid (C/P) ratio. A significant increase in the C/P ratio was detected in the ligated lobes 12 h and 3 days after PBL, but there was no significant difference in fluorescence polarization values between nonligated lobes and controls. These results suggest that alterations in membrane fluidity play an important role in the regenerative and atrophic processes of the liver following portal branch ligation.

Animals↗
PubMed1994

Inhibitory effect of fatty acids on 8-hydroxydeoxyguanosine formation in calf thymus DNA treated with bleomycin-Fe(II).

The effect of fatty acids on 8-hydroxydeoxyguanosine (8-OH-dG) formation in calf thymus DNA treated with bleomycin (BLM)-Fe(II) in vitro was studied. The formation of 8-OH-dG was greatly reduced in the presence of stearic acid (18:0) or oleic acid (18:1), however, it increased to the control level with an increase in the number of unsaturated bonds of fatty acids (18:2, 18:3). This increase in 8-OH-dG formation may have resulted from the indirect oxidation of DNA by the peroxidized unsaturated fatty acids formed by BLM-Fe(II). The inhibitory effect of saturated fatty acids on 8-OH-dG formation was observed with those possessing more than 12 methylene chains. Stearic acid also inhibited peroxidation of unsaturated fatty acids (18:2, 18:3) treated with BLM-Fe(II), however, it had no effect on ribose degradation of DNA treated with BLM-Fe(II). These results suggest that different active oxygen species are probably involved in DNA degradation and in formation of 8-OH-dG in DNA and of peroxidized products in fatty acids.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1994

[A case of prostatic cystadenoma].

We report a case of prostatic cystadenoma in a 45-year-old man with the complaint of urinary retention. The large mass was palpated on rectal examination. The tumor was localized in the position of the left lobe of the prostate and was seen as multi-ocular on computerized tomographic (CT) scan. The serum levels of prostatic acid phosphatase (PAP) and prostate specific antigen (PSA) were slightly elevated. The tumor was enucleated retropubically, it weighed 210 g and had an multilocular structure macroscopically. The cyst seen on microscopic examination was lined with cuboidal or columnar epithelial cells and the lining cells were focally multilayered and formed papillary projections. The stroma surrounding the glands was composed of fibrous tissue containing smooth muscle fibers. The epithelial cells were immunoreactive for PAP and PSA.

Cystadenoma↗
PubMed1994

[Prognosis of patient with intractable diseases in Wakayama Prefecture--a follow-up study based on medical care certificates].

To clarify the prognosis of patients with intractable diseases, a baseline survey of patients who received financial aid for intractable disease treatment between April 1984 and March 1985 was performed in Wakayama Prefecture, followed by a follow-up survey over a period of 8 years. Based on public welfare-subsidized system in Wakayama Prefecture, all patients with intractable diseases were checked up annually their certificates of financial aid for treatment. The results obtained were as follows: Parkinson's disease had the highest rate of discontinuation of medical care at 65%, followed by idiopathic thrombocytopenic purpura (ITP) at 64%, aplastic anemia at 55%, ulcerative colitis (UC) at 54%, and Behcet's disease at 50%. Systemic lupus erythematosus (SLE) had the lowest rate of discontinuation of medical care at 32%. Discontinuation was due to death in approximately 50% of the patients with SLE, scleroderma, dermatomyositis and polymyositis, and aplastic anemia. Of these, the causes of death in more than 50% were directly related to the primary diseases. However, in patients with SLE and aplastic anemia, 25% discontinued care because of cure or alleviation. Some patients remained in remission even though the prognosis for these diseases is not generally considered to be favorable. Transfer of jurisdiction to the Disabled Persons Welfare Act was seen in 28% of patients with Parkinson's disease, 24% with Behcet's disease, and 23% with ossification of posterior longitudinal ligament, diseases which are believed to cause restriction in daily activities of patients in some cases. On the other hand, cure or alleviation was the reason for discontinuation in 60-70% of patients with Buerger's disease, UC and ITP.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗