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Biomedical subjects

T Fukunaga

Publications and source records attributed to T Fukunaga.

At least 217 records · Page 12Linked to original sources
PubMed1993

Effects of methylmercury on protein kinase A and protein kinase C in the mouse brain.

The effects of methylmercury administration on adenosine 3',5'-cyclic monophosphate (cAMP)-dependent protein kinase (protein kinase A) and protein kinase C were investigated by determining their second messenger bindings ([3H]cAMP binding for protein kinase A and [3H]PDBu for protein kinase C) and enzymatic activities in the brains of methylmercury-treated mice. After single administrations of methylmercury (10 mgHg/kg, sc), no neurological symptoms were observed, while the mercury concentration in the brain reached 5.6 ppm. Neither second messenger bindings nor enzymatic activities of either protein kinase displayed significant changes. When methylmercury was administered repeatedly (10 mg Hg/kg x 5), the mercury concentration was 11.7 ppm and the enzymatic activity of protein kinase C was reduced to 75% of the control level without significant change in [3H]PDBu binding. Significant change has not been observed in either [3H]cAMP binding or enzymatic activity of protein kinase A. The reduction of enzymatic activity of protein kinase C was reversed by the simultaneous administration of selenite (0.5 mgSe/kg x 5). However, the fact that selenite administration alone displayed not a significant but about a 20% increase in [3H]PDBu binding suggested that selenite itself could affect the level of protein kinase C despite having no apparent effects on protein kinase C in vitro. Further investigation is necessary to assess whether protein kinase C is involved in the detoxication mechanism of selenite with respect to methylmercury. Since the mercury concentration in the brain was higher than the IC50s for both protein kinase A and protein kinase C observed in vitro even after single administration, methylmercury might inhibit both protein kinases, which might impair intracellular signal transduction. This might in part conceal the symptoms during the early stages of methylmercury toxicity.

Animals↗
PubMed1993

Quantitative analysis of revascularisation and new bone formation in experimental bone grafts. The use of an image input and processing system.

Revascularisation and new bone formation in bone grafts has been extensively studied by histological techniques, but the images obtained are very complex and consequently difficult to evaluate quantitatively. We report similar analyses in experimental bone grafts using newer computerised digital techniques. Fresh autografts and fresh and frozen allografts were used. The histological analogue images from them were input digitally into an image processor. The amount of revascularisation and new bone formation could then be quantified in the different grafts. This system has proved to be a useful method of evaluation which could be applied to the quantitative analysis of other histological images.

Angiography↗
PubMed1993

Differences in activation patterns in elbow flexor muscles during isometric, concentric and eccentric contractions.

To investigate the relative activation of the synergistic muscles during three different types of muscle contraction, the electromyograms (EMG) of two elbow flexor muscles, the biceps brachii (BB) and the brachioradialis (BR), have been compared. To accomplish this eight healthy human subjects performed the following elbow flexions against the same load--concentric, eccentric and isometric contractions. The isometric contractions were performed at three elbow angles: 10, 45 and 90 degrees (0 degree equal to full extension). The EMG were recorded by bipolar surface electrodes, and the relative activation between the two muscles was evaluated as the quotient of mean EMG activities (BR/BB). For the isotonic elbow flexions, BR/BB were calculated at three angle divisions: 0-30 degrees, 30-60 degrees and 60-90 degrees. Results indicated that the relative activation of the BR during the concentric contractions was higher than that of the eccentric contraction, particularly at the extended elbow angles, i.e. the BR/BB of the concentric contractions for the elbow joint angles ranging from 0-30 degrees and 30-60 degrees were significantly greater (P < 0.05) than those of the eccentric contractions. During the isometric and eccentric contractions, the BR/BB at the flexed joint angles tended to be greater than those at the extended angles. In contrast, there were no angle-dependent BR/BB variations during the concentric elbow flexions. Further, changing patterns in the EMG power spectra due to the type of contraction were different between BB and BR. These results indicated that the activation pattern in the two elbow flexor muscles varied with the muscle contraction pattern.

Adult↗
PubMed1993

Concentric and eccentric muscle strength before, during and after fatigue in 13 year-old boys.

The purpose of this study was to investigate the force-producing characteristics of boys aged 13 years in relation to fatigue of elbow flexor muscles. Maximal voluntary force in elbow flexion was measured before and after a muscle endurance test (MET) by using an isokinetic dynamometer isometrically, concentrically and eccentrically at three velocities, i.e. 0.21, 0.52, and 1.05 rad.s-1. The MET consisted of maximal concentric and eccentric muscle actions performed alternately at 0.52 rad.s-1 for 50 consecutive trials. Muscle cross-sectional area (CSA) of elbow flexor muscles (biceps brachii and brachialis) was measured by a B-mode ultrasound apparatus. Although eccentric force showed significantly higher values than concentric force during MET, there was no significant difference in the rate of decline in force between the two actions. There was no significant difference in the rate of decline in force after MET for each velocity and muscle action. Isometric, concentric and eccentric force before MET was significantly related to muscle CSA whereas, after MET, concentric force significantly correlated with muscle CSA but there was no significant correlation between muscle CSA and isometric or eccentric force. From our study, it is therefore suggested that in development to maturity, isometric, concentric and eccentric force decrease at the same rate with advancing muscle fatigue; however, there might be differences among muscle actions in factors affecting force development.

Adolescent↗
PubMed1993

Scales for mental state and daily living activities for the elderly: clinical behavioral scales for assessing demented patients.

In the diagnosis, treatment, and care of dementia patients in the senile stage, comprehensive evaluation of ability in daily life and mental function is needed. Using a simple behavioral rating scale for the mental states (NM scale) and activities of daily living (N-ADL) of the elderly, we evaluated 250 elderly subjects. According to the NM scale, the scores for subjects in whom the severity was clinically diagnosed were as follows: normal, 50-48; borderline, 47-43; mild dementia, 42-31; moderate dementia, 30-17; and severe dementia, 16-0. Screening for dementia and determining its severity were readily accomplished using the NM scale, and basic activities in the daily life of the elderly could be evaluated effectively using the N-ADL. There was a significant correlation (r = 0.863) between the Hasegawa dementia scale and the NM scale (p < 0.001), a significant correlation (r = -0.947) between intellectual function scores of the GBS scale and the NM scale, and a significant correlation (r = 0.944) between motor function score of the GBS scale and the N-ADL score. Evaluations of daily life activities can be made not only by psychiatrists and clinical psychologists, but by nonspecialists as well, because they are based on data obtained by observation of daily life behaviors; thus, assessment is appropriate both in clinical settings and in places of living.

Activities of Daily Living↗
PubMed1993

Occurrence of blood acetaldehyde in women during ethanol intoxication: preliminary findings.

The question of gender differences regarding blood acetaldehyde levels during ethanol intoxication has not been clarified because of the difficulties in the determination of acetaldehyde levels. Although the blood acetaldehyde levels in men during normal ethanol oxidation are reported to be undetectable, no valid data on female blood acetaldehyde levels have yet been reported. Thus, in the present investigation, 13 young healthy nonalcoholic women, almost all of which took oral contraceptives regularly, were challenged with different doses of ethanol (0.34, 0.68, and 1.02 g/kg) during three different sessions. Venous blood acetaldehyde and ethanol levels were then determined by headspace gas chromatography involving appropriate correction for artefactual acetaldehyde formation during blood treatment and analytical procedures. Corrected blood acetaldehyde levels (mean 2 microM, range 0-6 microM) were observed, predominantly at lower ethanol concentrations. Elevated acetaldehyde levels in women may explain why ethanol is less frequently abused and causes tissue damage more rapidly in women than men.

Acetaldehyde↗
PubMed1993

Muscle-fiber pennation angles are greater in hypertrophied than in normal muscles.

Muscle-fiber pennation angles were measured in vivo with the use of ultrasonography to investigate the relationship between fiber pennation and muscle size for 32 male subjects (from untrained subjects to highly trained bodybuilders). From the image of a B-mode ultrasonogram, fiber pennation angles and thickness of triceps brachii were determined, the former as angles between echoes from the interspaces of fascicles and from the aponeurosis of long and medial heads of triceps and the latter as the distance between the fat-muscle and muscle-bone interfaces. The pennation angles were in the range of 15 and 53 degrees for the long head and 9 to 26 degrees for the medial head, which were similar to or greater than the published and the present data on human cadavers. Significant differences were observed between normal subjects and bodybuilders in muscle thickness and pennation angles (P < 0.01), and there were significant correlations between muscle thickness and pennation angles for both long (r = 0.884) and medial (r = 0.833) heads of triceps, suggesting that muscle hypertrophy involves an increase in fiber pennation angles.

Adult↗
PubMed1993

Human blood acetaldehyde (update 1992).

Previously, it has been concluded that no detectable, adequately determined, acetaldehyde is to be found in the venous blood of normal Caucasian subjects during acute ethanol intake (Eriksson, 1983). Nevertheless, since then a number of reports on human blood acetaldehyde concentrations have been published. Most, if not all, of these levels can, however, be explained as being the result of artefactual sources. Thus, the early conclusion still holds, according to which the concentration of "free" and/or "loosely bound" acetaldehyde is below detection (< 0.5 microM), during normal conditions, i.e., with no deficiency in, or inhibition of, aldehyde dehydrogenase activity. Even if "free" and/or "loosely bound" acetaldehyde cannot be detected, the question of "more firmly bound" acetaldehyde has still remained open, and a number of papers have been published during the last few years on this aspect. Unfortunately, these investigations also have been seriously hampered by artefactual acetaldehyde formations during different hemolysation, hydrolysation, heating and/or other analytical procedures. The appropriate determination of bound acetaldehyde should in the future be better controlled for artefactual formations, even at very low ethanol concentrations (< 0.1 mM). Even if most of the artefactual formation is ethanol-derived, other sources for formation should also be considered. With a view to the present criteria, there is yet no valid demonstration of released acetaldehyde in human venous blood before, during, or after, normal ethanol intoxication.

Acetaldehyde↗
PubMed1993

[Evaluation of the cases of benign disease with high accumulation on the examination of 18F-fluorodeoxyglucose PET].

In this study 39 cases of abdominal benign disease were examined by PET using 18F-fluorodeoxyglucose (FDG), and 11 cases of them (i.e. 4 cases of liver abscess, 1 of pelvic abscess, 1 of omental abscess, 2 of chronic pancreatitis, 1 of inflammatory pseudotumor of liver, 1 of retroperitoneal leiomyoma and 1 of solid and cystic tumor of pancreas) which showed as high accumulation of FDG as malignant lesion were investigated of their clinical and pathological feature. We used Ci/Cp ratio as index to express the accumulation of FDG in the lesion, which was calculated from radioactivities of the lesion (Ci) and the plasma (Cp) at 60 mins after injection of FDG. The Ci/Cp ratio of the 11 cases was 3.64 +/- 0.77. The pathological feature of the 9 inflammatory cases was high accumulation of inflammatory cells and that of the 2 benign tumor cases was solid proliferation of tumor cells. The serum of the 9 inflammatory cases showed high CRP value. It was considered that the high accumulation of FDG in inflammatory lesions was due to piles of FDG uptake of the many inflammatory cells, while the 2 benign tumors of high accumulation were considered that the tumor cell had as high glucose metabolism as malignancies.

Chronic Disease↗
PubMed1993

[Four cases of advanced adenocarcinoma showing marked response to EAP (etoposide, ADM, CDDP) treatment].

Four cases of unresectable adenocarcinoma due to multiple metastasis were treated by EAP (etoposide, ADM, CDDP). The first was a 49-year-old male with gall bladder cancer, who was admitted to the hospital with metastatic umbilical tumor and intraabdominal dissemination. After 2 courses of treatment, the tumor was significantly decreased and the dissemination was diminished. The second was a 42-year-old female of breast cancer, involving lung, adrenal gland and bone metastasis. After 2 courses of treatment, all metastasis responded remarkably. Case 3 was a 42-year-old female with recurrent rectal cancer. Her lung metastasis completely disappeared after EAP treatment. Case 4 was a 42-year-old breast cancer patient with multiple liver metastasis, who also exhibited a remarkable response. In spite of severe side effects, EAP treatment was remarkably effective in all four cases of unresectable advanced adenocarcinoma.

Adenocarcinoma↗
PubMed1993

Problems involved in the determination of endogenous acetaldehyde in human blood.

Little is known about the possible existence of endogenous acetaldehyde in human blood. This has partly been due to analytical difficulties preventing accurate determination of blood acetaldehyde levels with and without the presence of ethanol. In the present study the possible existence of endogenous acetaldehyde in human blood was investigated with headspace gas chromatography using three different procedures for the treatment of samples: (1) no treatment of whole blood, cells, or plasma (direct headspace method), (2) hemolysation, and (3) perchloric acid (PCA) precipitation, prior to the headspace determinations. In in vitro experiments, with the direct headspace and the hemolysation methods, higher acetaldehyde peaks were obtained depending on the headspace incubation time, temperature and ethanol concentration. Both methods displayed about the same values of acetaldehyde in blood cells, ranging between 0 and 40 microM, at incubation times between 15 and 180 min, an incubation temperature of 65 degrees C, and ethanol concentrations less than 5 microM. Less acetaldehyde formation (0-15 microM) was obtained with PCA precipitates of whole blood and cell components. Very low acetaldehyde levels (0-1 microM) were obtained in the supernatants without precipitates from either whole blood or cells after headspace equilibration. Substantially less acetaldehyde was formed in plasma preparations than with whole blood and cell fractions. In human experiments, the disturbance of endogenous or exogenous ethanol was minimized by separating and washing the blood cells followed by PCA treatment. No differences in acetaldehyde concentrations were observed in blood samples taken before, during, or after ethanol intoxication (1.5 g/kg dose) of four healthy non-alcoholic volunteers.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetaldehyde↗
PubMed1993

Potential errors in measuring the phase difference between chest flow and mouth flow.

We have previously reported that the phase difference between chest and mouth flows was a useful indicator of obstructive lung disease. In this paper, we calculated the effects of (i) airway reactance, (ii) extrathoracic airway shunt impedance, (iii) heating and humidification of the inspired air, (iv) abdominal gas volume, and (v) respiratory quotient on the measurement of the phase difference between chest flow (Vc) and mouth flow (Vm) using computer simulations. When the airway impedance was approximated as simple airway resistance, the phase difference (theta r) was calculated to be 0.8% less than the phase difference (theta s) calculated from the airway impedance (Za), including airway inertance and shunt compliance, in the normal lung. theta s became larger than theta r when the peripheral resistance increased, but did not exceed 5%. The extrathoracic airway shunt impedance effect did not exceed 0.1%, regardless of the respiratory frequency, airway impedance or thoracic gas volume. The influence of heating and humidification of the inspired air on the phase difference was calculated to be within 5%. The effect of abdominal gas was highly dependent on the abdominal gas volume and the respiratory pattern, but was calculated to be within 5%. The influence of the respiratory quotient was calculated to be negligible. As a result, it was concluded that none of the factors discussed above are an obstacle to the clinical application of this method for the evaluation of pathological changes in obstructive airway disorders.

Airway Resistance↗
PubMed1993

[Perioperative psychological status of patients undergoing radical mastectomy and total hysterectomy].

Using four different psychological tests, namely Spielberger's rating scale [The State-Trait Anxiety Inventory (STAI)], Self-Rating Depression Scale (SDS), Maudsley Personality Inventory (MPI) and Baum test, we investigated the perioperative psychological status of patients undergoing radical mastectomy for breast cancer and compared data with those of patients undergoing total hysterectomy for uterine myoma. Parameters reflecting the psychological status of hysterectomy patients disclosed lower postoperative anxiety, and slight nervousness and persistent depression perioperatively. In contrast, in patients with breast cancer, those with nervousness had persistent anxiety and depression, while those without nervousness showed the same persistent depression as in hysterectomy patients, as well as a high anxiety level postoperatively. Therefore, we speculate that the persistence of depressive mood during the perioperative period is a factor in the psychological disturbance of mastectomy patients with breast cancer, and moreover, they appear markedly apprehensive because of cancer. These results suggest that the persistence of anxiety and depressive mood associated with cancer is a prime factor in the etiology of postoperative psychological disturbance.

Adult↗
PubMed1993

[Comparison between leucovorin and cisplatin as a modulator of 5-fluorouracil].

Currently, biochemical modulation for 5-fluorouracil (5-FU) by leucovorin (LV) and cisplatin (CDDP) seems one of the most successful chemotherapy for gastro-intestinal tract cancers. The mechanism of the modulation is thought to increase intracellular 5, 10-methylenetetrahydrofolate (CH2-H4 folate) levels. The purpose of this study is to examine the effect of LV and CDDP as a modulator of 5-FU. Either 10, 200, 400 mg/kg of LV or 2, 4, 6 mg/kg of CDDP were administered intravenously to mice bearing Sarcoma-180. Two hrs. later, CH2-FH4 folate levels were measured in tumor, muscle and intestine by thymidylate synthase (TS) binding assay. As the results, after administration of 200, 400 mg/kg of LV or 4, 6 mg/kg of CDDP, CH2-H4 folate level was elevated. This elevation was dose-dependent in LV. In contrast, no more elevation was observed after 6 mg/kg of CDDP injection. There was much smaller increase of CH2-H4 folate level was observed in the muscle and intestine. We conclude that the elevation of CH2-H4 folate levels depends on the organ and this leads to the tumor specificity in these chemotherapy.

Animals↗
PubMed1992

Physiological cross-sectional area of human leg muscles based on magnetic resonance imaging.

Magnetic resonance imaging techniques were used to determine the physiological cross-sectional areas (PCSAs) of the major muscles or muscle groups of the lower leg. For 12 healthy subjects, the boundaries of each muscle or muscle group were digitized from images taken at 1-cm intervals along the length of the leg. Muscle volumes were calculated from the summation of each anatomical CSA (ACSA) and the distance between each section. Muscle length was determined as the distance between the most proximal and distal images in which the muscle was visible. The PCSA of each muscle was calculated as muscle volume times the cosine of the angle of fiber pinnation divided by fiber length, where published fiber length:muscle length ratios were used to estimate fiber lengths. The mean volumes of the major plantarflexors were 489, 245, and 140 cm3 for the soleus and medial (MG) and lateral (LG) heads of the gastrocnemius. The mean PCSA of the soleus was 230 cm2, about three and eight times larger than the MG (68 cm2) and LG (28 cm2), respectively. These PCSA values were eight (soleus), four (MG), and three (LG) times larger than their respective maximum ACSA. The major dorsiflexor, the tibialis anterior (TA), had a muscle volume of 143 cm2, a PCSA of 19 cm2, and an ACSA of 9 cm2. With the exception of the soleus, the mean fiber length of all subjects was closely related to muscle volume across muscles. The soleus fibers were unusually short relative to the muscle volume, thus potentiating its force potential.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Reliability of measurement of oxygen uptake by a portable telemetric system.

The purpose of the present study was to check the reliability of measurements of oxygen uptake (VO2) using a newly developed portable telemetry system. This system (K2) consisted of a face mask, a flow meter, a gas analyser with a transmitter, and a receiver. The total mass for the subject to carry was about 850 g. Three experiments were carried out, firstly to check the reliability and reproducibility of the flow meter and the K2 gas analyser, secondly to check the accuracy of K2 by comparing it with the Douglas bag method (DB), and thirdly to apply K2 to sports activities. In the first experiment, the flow meter was highly accurate up to 180 l.min-1 with good reproducibility. The measurement error of the gas analyser was less than 2%. In the second experiment, there was no significant difference in the calculated ventilation between K2 and DB. The VO2 showed no significant difference between K2 and DB with some exceptions. In the third experiment, we succeeded in the measurement of VO2 during rowing on water. The measurement of VO2 during running and playing soccer was also possible. It would seem that the present system could well be a powerful tool in the field measurement of VO2 during various sports activities.

Exercise↗
PubMed1992

ABH-related antigens in human male genital tract. A histochemical examination.

The localization of ABH related antigens in human male reproductive tract was examined using monoclonal antibodies and an avidin biotin complex method. No positive reaction with blood group antibodies on spermatozoa was observed in testis and ductus epididymidis apart from erythrocytes and endothelial cells. The expression of ABH and ABH related antigens in ductuli efferents testis, ductus epididymidis, seminal vesicle and prostate was complexly coded by a combination of H, Se, Le and X genes. The results obtained in this study indicate that the ABH antigens detected on spermatozoa of seminal stains are coating antigens and not inherent to the cell membrane, and the ABO, H, Se, Le and X genes are subjected to a tissue-dependent differential expression.

ABO Blood-Group System↗