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Biomedical subjects

T Fukunaga

Publications and source records attributed to T Fukunaga.

At least 199 records · Page 11Linked to original sources

The severity of residual coronary stenosis immediately after thrombolytic therapy does not influence the size of later left ventricular asynergic area.

To determine whether the severity of residual coronary artery stenosis immediately after thrombolytic therapy influences the size of later left ventricular (LV) asynergic area, we reviewed coronary angiograms (CAGs) and left ventriculograms (LVGs) of 31 patients with acute myocardial infarction (AMI). All patients received intracoronary urokinase therapy within 6 h after onset of AMI due to total occlusion of the proximal left anterior descending coronary artery (LAD). A dose of 960,000 IU urokinase was infused into the ostium of the left coronary artery over 40 min. Patients in whom antegrade blood flow without delayed distal filling was restored received rigorous anticoagulation. The patients were divided into three groups according to the severity of the coronary lesion immediately after urokinase therapy: 9 patients with complete occlusion in Group 1, 15 with > 90% stenosis in Group 2, and 7 with < 90% stenosis in Group 3. There were no significant differences in the baseline clinical characteristics among the patients in the three groups. The LADs in Group 1 were also totally occluded 1 month after urokinase therapy, the treated vessels in both Groups 2 and 3 were still patent, and patients in Group 2 showed a further reduction in residual stenosis. When LV asynergic area, regional wall motion, and global ejection fraction (EF) were compared among the three groups, no significant differences were demonstrated. In comparison with the data immediately after urokinase therapy, all parameters 1 month after therapy were significantly improved in both Groups 2 and 3.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Specific tension of elbow flexor and extensor muscles based on magnetic resonance imaging.

Series cross-section images of the upper extremity were obtained for four men by magnetic resonance imaging (MRI) and anatomical cross-sectional areas (ACSA) of elbow flexor muscles [biceps brachii (BIC), brachialis (BRA), brachioradialis (BRD)] and extensor muscles [triceps brachii (TRI)] were measured. Physiological cross-sectional area (PCSA) was calculated from the muscle volume and muscle fibre length, the former from the series ACSA and the latter from the muscle length multiplied by previously reported fibre/muscle length ratios. Elbow flexion/extension torque was measured using an isokinetic dynamometer and the force at the tendons was calculated from the torque and moment arms of muscles measured by MRI. Maximal ACSA of TRI was comparable to that of total flexors, while PCSA of TRI was greater by 1.9 times. Within flexors, BRA had the greatest contribution to torque (47%), followed by BIC (34%) and BRD (19%). Specific tension related to the estimated velocity of muscle fibres were similar for elbow flexors and extensors, suggesting that the capacity of tension development is analogous between two muscle groups.

Adult↗

Comparison of muscle cross-sectional area and strength between untrained women and men.

The cross-sectional areas (CSA) of fat, muscle and bone tissues of the limb as well as maximal voluntary isokinetic strength were measured in untrained men (n = 27) and women (n = 26) aged 18-25 years. Anatomical CSA of the three tissues were determined by ultrasound on the upper arm and thigh. The isokinetic strength of the elbow and knee extensor and flexor muscles were measured by an isokinetic dynamometer (Cybex II) at 1.05 rad.s-1. The women had significantly (P < 0.001) larger fat CSA and smaller bone and muscle CSA than the men in both the upper arm and thigh. Among tissue CSA, the largest difference between the women and men was found in fat CSA regardless of the measurement sites. The sex differences in bone and muscle CSA were found largely in the upper arm compared to the thigh, even when expressed per unit second power of the limb length. Regression analyses of the data for respective samples for the men and women showed significant correlations (r = 0.411-0.707, P < 0.05-P < 0.001) between CSA and strength in all muscle groups except for the elbow extensors of the men (r = 0.328, P > 0.05) and the elbow flexors of the women (r = 0.388, P > 0.05). No significant difference between sexes was observed when strength was expressed per unit of muscle CSA (F.CSA-1) for the elbow flexors and extensors. However, the men showed significantly higher F.CSA-1 than the women for the knee flexors and extensors (P < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Strength and cross-sectional area of knee extensor muscles in children.

Isokinetic strength and cross-sectional area (CSA) of knee extensor muscles were examined in 60 boys and girls, aged 6-9 years, and in 71 young adult men and women to investigate the influences of age and gender on the strength capabilities in relation to muscle size. A single anatomical CSA of quadriceps femoris at the right mid-thigh was measured by using a B-mode ultrasonic apparatus. Isokinetic strength produced at three kinds of constant velocity, 1.05, 3.14, and 5.24 rad.s-1, was significantly correlated to the product of CSA and thigh length (TL) in separate samples by age and gender. In both genders, however, young adults had significantly higher ratios of strength to CSA.TL (ST.CSA-1.TL-1) than children at all measurement velocities. Relative differences in ST.CSA-1.TL-1 between children and young adults became larger with increasing test velocity. Within the same generation, men had significantly higher ST.CSA-1.TL-1 than women at all measurement velocities except for the ratio in children at 1.05 rad.s-1. These results indicate that the ability to produce strength proportional to muscle size is lower in children than in young adults, regardless of gender, and lower in women than in men within the same generation.

Adolescent↗

Determination of ABO genotypes with DNA extracted from formalin-fixed, paraffin-embedded tissues.

The gene encoding the specific glycosyltransferases which catalyze the conversion of the H antigen to A or B antigens shows a slight but distinct variation in its allelic nucleotide sequence and can be divided into 6 genotypes when digested with specific restriction enzymes. We extracted DNA from formalin-fixed, paraffin-embedded tissues using SDS/proteinase K treatment followed by phenol/chloroform extraction. The sequence of nucleotides for the A, B and O genes was amplified by the polymerase chain reaction (PCR). DNA fragments of 128 bp and 200 bp could be amplified in the second round of PCR, using an aliquot of the first round PCR product as template. Degraded DNA from paraffin blocks stored for up to 10.7 years could be successfully typed. The ABO genotype was deduced from the digestion patterns with an appropriate combination of restriction enzymes and was compatible with the phenotype obtained from the blood sample.

ABO Blood-Group System↗

Plasma concentration of human brain natriuretic peptide in patients on hemodialysis.

The plasma concentration of immunoreactive human brain natriuretic peptide (ir-BNP) was measured in 40 patients on hemodialysis (HD) and in 12 healthy subjects. Immunoreactive human atrial natriuretic peptide (ir-ANP) was also measured. The mean (+/- SE) plasma ir-BNP concentration in the patients before HD (18.4 +/- 3.4 fmol/mL) was markedly higher than that in the control group (0.39 +/- 0.08 fmol/mL). The plasma ir-BNP level was significantly decreased by HD from 18.4 +/- 3.4 fmol/mL to 10.5 +/- 2.2 fmol/mL (P < 0.001), but the latter value was still higher than the upper limit of the normal range for our laboratory. There were significant correlations between the plasma ir-ANP level and the mean blood pressure before HD (P < 0.05) and between the HD-induced changes in plasma ir-ANP level and mean blood pressure (P < 0.001). These correlations were not observed between the plasma ir-BNP level and mean blood pressure. The plasma ir-BNP level correlated with the cardiothoracic ratio and this correlation was closer to that between the plasma ir-ANP level and cardiothoracic ratio. Ultrasound echocardiographic studies in 13 patients revealed that the pre-HD state of high cardiac output was correlated by HD in association with decreases in plasma ir-BNP and ir-ANP levels. Correlations were observed between the pre-HD ir-ANP level and the interventricular septal thickness index (r = 0.68, P < 0.05) and between the change in ir-BNP level and that in left atrial diameter (r = 0.806, P < 0.001). In conclusion, BNP levels were high in HD patients compared with the control subjects and were decreased during HD. In addition, BNP and ANP levels correlated with several parameters of volume change and cardiac status.

Atrial Natriuretic Factor↗

Cross-sectional areas of fat and muscle in limbs during growth and middle age.

Age changes in the cross-sectional areas (CSAs) of fat and muscle tissues of limbs were investigated by using a B-mode ultrasonic technique for 245 males and 275 females aged 6 to 60 years. Four measurement sites were selected in the right limbs: the forearm, upper arm, lower leg and thigh. In an age span from 13 to 15 years, fat CSA for males decreased, while that for females increased at every site. Fat CSAs for both sexes increased in their thirties, but from then there was no more increase with aging. During early childhood, females had similar growth curves in muscle CSAs to those of males. An apparent sex separation in muscle CSAs took place at 13 years of age and after, the relative gender differences in muscle CSAs became larger with growth in the upper extremity than in the lower one. For both sexes, muscle CSA in every site remained almost constant during middle age. This age change in fat and muscle CSAs of limbs during the period of growth generally resembles that reported previously for total fat and fat free mass, respectively. However, age trend in fat CSAs during middle age, a lack of increase on reaching and after the forties differs from that described by prior studies for fat mass.

Adipose Tissue↗

Epidemiological and ecological studies of Japanese encephalitis in Okinawa, subtropical area in Japan. I. Investigations on antibody levels to Japanese encephalitis virus in swine sera and vector mosquito in Okinawa, Miyako and Ishigaki islands.

From 1985 to 1989, serum specimens of swine raised in the northern, central and southern areas in Okinawa island were examined for Japanese encephalitis (JE) virus antibody by ELISA and hemagglutination-inhibition test. The antibody positive rate was found to be higher in the north and central than in the south. The 2-mercaptoethanol sensitive antibody to JE was detected mostly in June and July, and occasionally in other months except February and March. There was no month when all specimens from three areas turned antibody-negative simultaneously, indicating that JE virus transmission to swine lasted longer in Okinawa island than in other temperature areas in Japan. From 1986 to 1991, the vector mosquitoes (Culex tritaeniorhynchus) were collected in a pig farm in the south of Okinawa island. A total of 153 strains of JE virus was isolated from the vector mosquitoes mainly in June. In Miyako and Ishigaki islands, the antibody positive rate in swine sera was found to be extremely low, compared with that in Okinawa island. In Miyako island, where no paddy rice field is cultivated, a few adults as well as larvae of the vector mosquito were collected, while in Ishigaki island, where there are many watered rice fields, a lot of adults as well as larvae were collected. Although the environmental situation is quite different between the two islands, JE virus transmission appeared to be very low in both islands.

Animals↗

Epidemiological and ecological studies of Japanese encephalitis in Okinawa, subtropical area in Japan. II. Prevalence of Japanese encephalitis antibody in residents in Okinawa, Miyako and Ishigaki islands.

During 1989 to 1990, human sera were collected by age groups in Okinawa (the northern, central and southern areas), Miyako and Ishigaki islands and examined for the neutralization (N) antibodies to two strains, Nakayama (vaccine strain) and C307 (Okinawan strain), of Japanese encephalitis (JE) virus. In Okinawa island, the N antibody positive rate to C307 was higher than that to Nakayama, while in Miyako and Ishigaki islands, the positive rate to Nakayama was higher than that to C307, suggesting that JE virus transmission rate was higher in Okinawa than in Miyako and Ishigaki islands. In Okinawa Prefecture, JE vaccine had not been administered to most of residents over 31 years of age at the time of serum collection. In residents over 31 years old, the positive rate to C307 was highest in the north of Okinawa (83.3%) and was lowest in Miyako (26.3%), with the second lowest in Ishigaki (33.3%). The distribution of N antibody titers to C307 gave hyperbolic patterns in the 0-5 age groups in Miyako and Ishigaki, and also in the 31-40, 41-50 age groups in Miyako and the 41-50 age group in Ishigaki, suggesting low rates of natural infection in these 4-5 decades in both islands. In residents of ages subjected to JE vaccine, a characteristic pattern was obtained, in which the curves to Nakayama shifted to higher titers than those to C307, suggesting that the first antigenic stimulation was caused by vaccine, not by natural infection of JE virus.

Adolescent↗

Studies on serological cross-reaction in sequential flavivirus infections.

Acute- and convalescent-phase sera from patients with dengue (DEN) hemorrhagic fever (DHF) and Japanese encephalitis (JE) that contained pre-existing flavivirus antibodies were tested for cross-reacting antibodies to DEN, JE and yellow fever (YF) viruses by a neutralization (N) test. A fourfold or greater rise in N antibody titer in the convalescent-phase was considered significant. Of 39 DHF cases, obtained at Chiang Mai University Hospital, Thailand, 15 (38.5%) showed a rise in DEN antibody titer, while another 15 (38.5%) showed a significant rise in both DEN and JE N antibody titers. On the other hand, eight (61.5%) of 13 JE cases obtained at the same Hospital, showed a significant rise in JE antibody titer, while two (15.4%) showed a significant rise in both DEN and JE antibody titers. Sucrose gradient centrifugation and fractionation of these two cross-reactive JE sera revealed that IgM class antibody was specific for JE, while IgG class antibody was cross-reactive. Of three JE cases with pre-existing YF antibody obtained in Okinawa, Japan, two showed a significant rise in YF and JE antibodies. Both IgM and IgG class antibodies to YF virus were elevated. These results indicate that the cross-reactivity among flaviviruses in different subgroups (complexes), was observed quite often, even by the N test, in sequential flavivirus infection.

Acute Disease↗

Effect of pulmonary blood flow on microvascular pressure profile determined by micropuncture in perfused cat lungs.

To clarify the role of the pulmonary microvasculature in adjusting to increased pulmonary blood flow, we measured arteriolar and venular pressure by the servo-null micropuncture method while changing the pulmonary blood flow in isolated perfused cat lungs. We divided the lung vasculature into three longitudinal segments: 1) arterial (pulmonary artery to 30- to 50-microns arteriole), 2) microvascular (between 30- to 50-microns arteriole and venule), and 3) venous (30- to 50-microns venule to left atrium). The vascular resistance was calculated by dividing the pressure gradient by the flow. The pressure gradient of the microvascular segment did not increase, whereas the pressure gradient of the arterial and venous segments increased simultaneously with flow rate. Total and microvascular resistance decreased with increase of flow rate. Resistances of the arterial and venous segments did not change with increase in flow. We conclude that the microvasculature plays a crucial role in preventing pulmonary hypertension with increases in flow by decreasing microvascular resistance.

Animals↗

Relationships between subcutaneous fat and muscle distributions and serum HDL-cholesterol.

To evaluate the relationship between human body composition and serum lipids levels, the distributions of subcutaneous adipose tissue (AT) and muscle thickness were evaluated in Japanese 449 males and 542 females, aged from 35 to 77 years. Among males, a significant positive correlation was observed between AT thicknesses and total cholesterol, and negative relationships between the AT and HDL-C as well as HDL-C/TC ratio. Among females, similar but weaker relationships were found for AT at the upper arm and trunk sites. However, the thigh AT thickness was positively correlated with HDL-C and HDL-C/TC ratio only among women. The muscle thickness in the abdomen and the thigh correlated significantly with HDL-C/TC for both sexes. Furthermore, the regional trend observed in both sexes remained significant after correction for concomitant variables such as age, tobacco and alcohol intake. We conclude that it is necessary to evaluate not only total body fat but muscle and AT thickness distributions when evaluating the relationship between body composition and serum lipids and lipoproteins.

Adipose Tissue↗

Involvement of genetic polymorphism of alcohol and aldehyde dehydrogenases in individual variation of alcohol metabolism.

The involvement of genetic polymorphism at the alcohol dehydrogenase 2 (ADH2) and aldehyde dehydrogenase 2 (ALDH2) loci in determining blood acetaldehyde levels and the rate of ethanol elimination after ethanol intake was investigated. Sixty-eight healthy subjects ingested 0.4 g of ethanol per kg of body weight over 10 min. Blood acetaldehyde levels scarcely increased in the subjects homozygous for ALDH2*1, regardless of their ADH2 genotypes (ADH2*1/*1, ADH2*1/*2 and ADH2*2/*2). The acetaldehyde levels in the subjects with the ALDH2*1/*2 heterozygote increased to 23.4 microM on average, and no significant differences were observed between the three ADH2 genotype groups. Subjects homozygous for ALDH2*2 showed very high levels of blood acetaldehyde, and the average value was 79.3 microM. The values of Widmark's beta 60 (mg/ml/hr) and ethanol elimination rate (mg/kg/hr) showed significant differences among the three ALDH2 genotypes, and in decreasing order the values were ALDH2*1/*1, ALDH2*1/*2, ALDH2*2/*2. However, no significant differences were seen among the ADH2 genotypes.

Acetaldehyde↗

[Analysis of glucose metabolism in patients with esophageal cancer by PET: estimation of hexokinase activity in the tumor and usefulness for clinical assessment using 18F-fluorodeoxyglucose].

We evaluated glucose metabolism of esophageal cancer by PET using 18F-fluorodeoxyglucose (FDG), in order to investigate its clinical usefulness. In 11 advanced cases k3 value reflecting hexokinase activity and Ci/Cp ratio expressing FDG uptake were calculated from radioactivity in the tumor (Ci) and the plasma (Cp). Both k3 and Ci/Cp were well correlated with hexokinase activity from the resected specimen, so Ci/Cp was considered to be a convenient index for clinical assessment of esophageal cancer. Forty-two cases before treatment revealed high accumulation of FDG, and 41 showed more than 2.0 of Ci/Cp. But, 10 normal controls and one esophageal benign tumor showed less than 2.0. As for 13 post-operative cases, 6 cases out of 7 with recurrence showed more than 2.0 for Ci/Cp, but all 6 cases of non-recurrent cases showed less than 2.0. FDG PET is an useful tool for differential diagnosis of recurrence. The clinicopathological findings were investigated in 26 resected cases. Age, location, vertical extension, histologic feature, lymph node metastasis and histologic stage were not correlative with Ci/Cp. As for DNA ploidy pattern, aneuploidy group showed significantly high Ci/Cp rather than diploidy group. Eight cases which showed more than 5.0 of Ci/Cp resulted in poor prognoses compared with 14 cases which showed less than 5.0.

Aged↗

A study on ADH2 and ALDH2 genotyping by PCR-RFLP and SSCP analyses with description of allele and genotype frequencies in Japanese, Finn and Lapp populations.

Genetic polymorphisms of the alcohol dehydrogenase ADH2 and aldehyde dehydrogenase ALDH2 genes were investigated in Japanese, Finn, and Lapp populations by using PCR-RFLP and SSCP analyses. The ALDH2 genotypes were unequivocally determined by a PCR-RFLP assay with a mismatched primer. The determination of the ADH2 genotypes, however, was found to be problematic in PCR with the reported oligonucleotide primer sets because there are high homologies among the ADHl, ADH2, and ADH3 gene sequences. The problem of the heterozygote excess in typing results obtained by using the previously reported PCR-RFLP methods was resolved by nested PCR, in which an internal primer set reamplified the ADH2 sequence selectively from a mixture of the ADH gene sequences amplified in the first PCR amplification of genomic DNA samples as templates. A newly designed primer pair with longer sequences and single 3' end mismatches was later found to achieve a predominant amplification of the ADH2 sequence in a single PCR. RFLP and SSCP analyses of PCR products with the new primer set gave results fully consistent with those by nested PCR. Thus, the ADH2 genotypes defined in this study were free from any typing errors. The ADH2 and ALDH2 allele frequencies observed in this study were found not to be biased significantly from those reported previously from Japanese populations, and these were monomorphic for Lapp and Finn populations.

Alcohol Dehydrogenase↗

Semi-automatic method for determination of different isoforms of carbohydrate-deficient transferrin.

Carbohydrate deficient transferrin (CDT) has been reported to be one of the best biochemical markers of alcohol abuse. However, a need still exists for a simple and practical method for widespread laboratory use. A semi-automatic (SA) isoelectric focusing (IEF) assay for CDT (SA-IEF-CDT) by a Phast System is introduced here. Different isoforms of transferrin were separated by IEF on polyacrylamide gels (pI 4.0-6.5) and located by immunofixation with an anti-transferrin serum. The precipitation bands were stained with Coomassie Brilliant Blue and quantitated densitometrically. The present method gave a picture of the relative amounts of 10 different transferrin isoforms. The percentage of CDT with pI > or = 5.7 (representing di-, mono- and asialotransferrin) was calculated. For comparisons transferrin bands with pI > or = 5.6 (tri-, di-, mono-, and asialotransferrin), pI > or = 5.8 (mono- and asialotransferrin) and pI > or = 5.9 (asialotransferrin) as well as GGT, ASAT and ALAT were calculated. The method showed good linearity and it identified different isoforms in concentrations of < 10 mg/l of transferrin. The correlation of the present method with a commercially available method employing anion exchange followed by double antibody RIA (AE-RIA-CDT) was good (n = 38, r = 0.924). In 19/20 (95%) of healthy controls, the CDT value was below 4.4% (mean + 2 S.D.) of total transferrin, while higher values were observed in all 20 (100%) alcoholics. In conclusion, the developed semi-automatic method is a practical and reliable alternative for determination of different transferrin isoforms.

Adult↗

Allocation of mouse cerebellar granule cells derived from embryonic ventricular progenitors--a study using a recombinant retrovirus.

Granule cells of the mammalian cerebellar cortex originate from embryonic progenitors present in the ventricular germinal layer. To investigate the allocation fate of these ventricular progenitors in the mouse, we labeled a few of them on embryonic day 13 with a recombinant retrovirus carrying lacZ which encodes E. coli beta-galactosidase (beta-gal), and the labeled cells in the postnatal cerebellar cortex were detected by beta-gal histochemistry. In the postnatal cerebellar cortex, the virally-labeled beta-gal+ granule cells formed discrete clusters. These clusters were not compactly packed with the beta-gal+ cells, and there was intermingling with beta-gal- granule cells. Neither beta-gal+ Purkinje cells nor glia were found to be included in the clusters. Most of the granule cell clusters were incompatible with the functional areas of the cortex. These results suggest: (1) granule cells derived from individual ventricular progenitors are allocated in clusters and are not extensively dispersed, (2) granule cells descended from one progenitor may mix with their neighbors that are descended from another progenitor, (3) the allocation fate of the ventricular progenitors of granule cells is not restricted to the functional areas of the cerebellar cortex.

Animals↗