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Biomedical subjects

M Tachi

Publications and source records attributed to M Tachi.

At least 19 recordsLinked to original sources
PubMed2003

Effect of low-load resistance training on the tendon properties in middle-aged and elderly women.

AIM: The purposes of this study were to determine the age-related changes in the tendon-aponeurosis structures and to investigate the effects of low-load resistance training on the tendon-aponeurosis structures in middle-aged and elderly women. METHODS: Fifty-one women (55.8 +/- 13.7 years, range: 21-77 years) volunteered to take part in the present study. Furthermore, 11 middle-aged and elderly women (49.7 +/- 9.2 years) performed the low-load resistance training, i.e. squat using body weight, for 6 months. The elongation of the tendon and aponeurosis of the vastus lateralis muscle was directly measured by ultrasonography, while the subjects performed ramp isometric knee extension up to the voluntary maximum, followed by a ramp relaxation. The relationship between the estimated muscle force (Fm) and tendon elongation (L) during the ascending phase was fitted to a linear regression, the slope of which was defined as stiffness. The percentage of the area within the Fm-L loop to the area beneath the curve during the ascending phase was calculated as hysteresis. RESULTS: Maximal strain (L/initial tendon length) and stiffness of the tendon-aponeurosis structures decreased significantly with ageing. In contrast, the hysteresis increased significantly with ageing. In addition, low-load resistance training produced no significant change in stiffness and hysteresis, but significantly increased the maximal elongation of tendon-aponeurosis structures from 23.3 +/- 2.1 mm to 24.8 +/- 2.2 mm (P = 0.045). CONCLUSION: These results suggest that increasing age results in a decrease in the elasticity of tendon-aponeurosis structures and an increase in their viscosity. Furthermore, the low-load resistance training made the elasticity of tendon-aponeurosis structures increase.

Adult↗
PubMed2001

Muscle volume is a major determinant of joint torque in humans.

Muscle force (MF) is linearly related to physiological cross-sectional area (CSA), which is obtained from muscle volume (MV) divided by fibre length. Taking into account the fact that joint torque (TQ) is determined by MF multiplied by the moment arm, the maximal TQ would be a function of MV. This proposition was tested in the present study by investigating the relationship between MV and TQ for elbow flexor (EF) and extensor (EE) muscles of 26 males. The MVs of EF and EE were determined from a series of muscle CSA by magnetic resonance imaging (MRI), and pennation angle (theta) and FL by ultrasonography (US). Maximal isometric TQ was measured at right angle of elbow joint for EF and EE. There was a highly significant correlation between MV and TQ both for EF and EE (r=0.95 and 0.96 respectively) compared with that between muscle CSA and TQ, suggesting the dependence of TQ on MV. Furthermore, prediction equations for MV (MVULT) from muscle thickness (MT) measured by US was developed with reference to MVMRI by the MRI on 26 subjects, and the equations were applied to estimate MV of healthy university students (CON; 160 males) and sports athletes (ATH; 99 males). There were significant linear relationships between MVULT and TQ both for EF (r=0.783) and EE (r=0.695) for all subjects (n=259). The MVULT was significantly higher in ATH (by 32% for EF and 33% for EE, respectively) than in CON. Similarly, significantly greater TQ was observed in ATH (by 35% for EF, 37% for EE, respectively). The theta for EE showed no difference between both groups (17.8 degrees for CON and 17.5 degrees for ATH). On the other hand, the TQ to MV ratio were identical for CON and ATH. The results reveal that the muscle volume of the upper arm is a major determinant of joint torque (TQ), regardless of athletic training.

Adult↗
PubMed2001

Unusual development of acute compartment syndrome caused by a suction injury: a case report.

There have been recent reports of acute compartment syndrome secondary to suction injuries of the hands of children. We report the case of a 68-year-old patient who developed an acute compartment syndrome of the forearm after his arm had been sucked into an exhaust port. He was treated by emergency fasciotomies and the wound was closed five days later with a small skin graft. His recovery was uneventful.

Acute Disease↗
PubMed2001

Optimized 3-D CT scan protocol for longitudinal morphological estimation in craniofacial surgery.

Frequent three-dimensional computed tomography scanning may cause deterioration of the lenses of the eye, which are susceptible to x-rays. The authors performed an experimental study using a phantom head to establish an optimized three-dimensional computed tomography scan protocol for longitudinal morphological estimation in craniofacial surgery. Volume computed tomography scans were performed using a Hi-Speed Advantage SG CT scanner (GE Medical Systems, Milwaukee, WI) in the axial plane with a combination of scan parameters of varied values. The radiation doses induced by each scanning were measured using thermoluminescent dosimeter chips attached to the position of the lenses in the phantom. Two-dimensional images in the coronal plane and three-dimensional images of the osseous surface were generated from each accumulated data set. For each scan parameter, the images generated from data accumulated using different values were compared. The study showed that lens radiation dose increased with tube potential and was almost directly proportional to tube current and 1/pitch. The slice thickness did not affect lens radiation doses significantly. Images with good contrast resolution and low artifact level sufficient for estimating morphological changes were obtained using a low tube potential of 100 kVp and a tube current of 100 mA. In regard to z-axis spatial resolution, a slice thickness of less than 3 mm was required for precisely pointing out bony edges in the two-dimensional reformation images. These results led us to conclude that volume computed tomography for longitudinal examination in craniofacial surgery should be kept to a minimum frequency and performed using a low-dose technique, small slice thickness, and large pitch.

Artifacts↗
PubMed2001

Muscle fiber and tendon length changes in the human vastus lateralis during slow pedaling.

Muscle fascicle lengths of vastus lateralis (VL) muscle were measured in five healthy men during slow pedaling to investigate the interaction between muscle fibers and tendon. Subjects cycled at a pedaling rate of 40 rpm (98 W). During exercise, fascicle lengths changed from 91 +/- 7 (SE) to 127 +/- 5 mm. It was suggested that fascicles were on the descending limb of their force-length relationship. The average shortening velocity of fascicle was greater than that of muscle-tendon complex in the first half of the knee extension phase and was less in the second half. The maximum shortening velocity of fascicle in the knee extension phase was less than that of muscle-tendon complex by 22 +/- 9%. These discrepancies in velocities were mainly caused by the elongation of the tendinous tissue. It was suggested that the elasticity of VL tendinous tissue enabled VL fascicles to develop force at closer length to their optimal length and kept the maximum shortening velocity of VL fascicles low during slow pedaling.

Adult↗
PubMed2000

A practical synthesis of the ABC ring model of ecteinascidins.

A practical synthesis of 1,2,3,4,5,6-hexahydro-1,5-imino-10-hydroxy-9-methoxy-3,8,11-trimethyl-3- benzazocin-4-one (3) as an ABC ring model compound of ecteinascidin 743 and safracins from 3-hydroxy-4-methoxy-5-methylbenzaldehyde (7) is described. The overall yield in 15 steps is 27%.

Dioxoles↗
PubMed1999

Detection of single-stranded cohesive ends in the genome of Bacillus thuringiensis temperate phage KK-88.

Cohesive ends (cos sites) were detected in the genome of temperate KK-88 phage in Bacillus thuringiensis after analysis of the phage DNA generated by the 3'-5' exonuclease activity of Klenow fragment of DNA polymerase I. In addition, unlike the 5'-protruding ends of coliphage lambda genome, the ends of KK-88 phage genome were found to be 3'-protruding. The restriction map of the phage genome was also constructed on the basis of position of the cos fragments.

Bacillus thuringiensis↗
PubMed1997

Role of alternative splicing of the rat erythropoietin receptor gene in normal and erythroleukemia cells.

An alternatively splicing of the rat erythropoietin receptor (EpoR) gene was identified in normal and erythroleukemia cells by the reverse transcription PCR method. Insertion of a 105 bp fragment at the region corresponding to the extracellular domain of rat EpoR was found. The insert sequence, which encodes additional 21 amino acids, is similar to that previously found in the mouse EpoR gene, however, has an additional 27 bp direct repeat. Due to the presence of a stop codon in the insert, the alternative transcript is translated to a truncated and soluble form of EpoR which is preferentially expressed in liver, spleen, kidney, heart, and bone marrow cells as well as cultured erythroleukemia cells. These findings suggest that alternative splicing of the EpoR gene may play an important role in proliferation and differentiation of rat erythroid cells.

Alternative Splicing↗
PubMed1995

Induction of Fas-mediated apoptosis in p53-transfected human colon carcinoma cells.

To investigate the biological function of p53 in colon carcinoma cells, a wild-type p53 expression plasmid under the control of the human cytomegalovirus promoter was stably transfected into the human colon adenocarcinoma cell line WiDr, which carries a mutation of the p53 gene at codon 273. Exogenous wild-type p53 transcripts were detected at various expression levels in 8 of 117 G418-resistant clones. The growth rates of the wild-type p53+ clones in culture did not change significantly. The efficiency of colony formation in soft agar, however, was completely suppressed in two wild-type p53+ clones. This is the first to demonstrate the feasibility of stable transfection of the wild-type p53 gene under the control of non-inducible promoter in human colon cancer cells. The major alteration found was that wild-type p53+ cells which were incubated with anti-Fas IgM showed marked cytolysis with preferential over-expression of wild-type p53 accompanied by overexpression of a cyclin-dependent kinase inhibitor, WAF1, whereas the endogenous mutant p53 retained its expression level. The findings suggest that a Fas-initiated pathway is incidentally linked to a p53-dependent apoptotic pathway through the reconstituted wild-type p53 gene in WiDr cells. This model should help elucidating the additional role of the p53 tumor suppressor gene and the mechanism of apoptosis in colon carcinoma cells.

Adenocarcinoma↗
PubMed1994

Programmed expression of cholesterol sulfotransferase and transglutaminase during epidermal differentiation of murine skin development.

To clarify the role of cholesterol sulfate (CS) in the process of epidermal differentiation in vivo, we investigated the concentration of CS and the specific activities of cholesterol sulfotransferase (CST), cholesterol sulfate sulfatase (CS sulfatase) and epidermal transglutaminase (ETG) in murine skin in the pre- and postnatal periods. In the skin at day 14 of gestation, CS was not detected with TLC and the specific activities of all the enzymes were low. However, concomitant with the formation of the multilayered structure of the epidermis (at day 16), the specific activities of CST steeply increased. Although the insoluble CS sulfatase in the microsomal fraction remained at a relatively constant level, the soluble CST in the cytosol fraction showed a 6-fold increase from day 14 to day 16, and the activity decreased continuously in the following period, reaching one forty-sixth of the maximum level at 4-months-old mice. Reflected by the increase in activity, CS was detected in fetal skin at day 15, and the concentration in epidermis significantly increased during the gestation period, reaching maximum level at day 17. Furthermore, the changes in the concentration of cholesterol sulfate were identical with those of N-(O-linoleoyl)-omega-hydroxy fatty acyl sphingosine and its glucosyl derivative in the epidermis. On the other hand, the specific activity of ETG increased after birth. Thus, the activation of CST and ETG was shown to occur separately in association with the formation of the multilayered structure and thickening of the stratum corneum, respectively.

Animals↗
PubMed1993

Difficulty in removing a percutaneous central venous catheter inserted from a peripheral vein.

Two girls with acute lymphocytic leukemia (ALL) are reported. There were difficulties in removing their central venous catheters inserted from a peripheral vein. One girl required surgery under general anesthesia for the removal. The other patient received continuous infusion of low dose urokinase from a distal peripheral vein. The residual catheter was then removed successfully.

Adolescent↗
PubMed1992

Health profiles of workers exposed to acrylonitrile.

The objective of this study was to reveal the health effects of acrylonitrile (AN) in seven Japanese acrylic fiber manufacturing factories. The study subjects were 157 AN-exposed male shift workers who had been exposed to AN for 17 years on the average and 537 control workers whose working conditions were similar to those of the AN-exposed workers. The seven factories were classified into two groups according to their AN exposure levels in 1987, and also into three groups on the basis of 1976 exposure levels. The most highly exposed group of subjects showed a mean AN concentration of 1.13 ppm by personal sampling. Medical examination failed to detect any health effects attributable to long-term exposure to AN, although the existence of some symptoms of acute irritation could not be completely ruled out. The results of this study may provide a "no observed effects level" for human on-the-job exposure with regard to the health effects examined here.

Acrylonitrile↗
PubMed1990

Histochemical and biochemical studies in a patient with myophosphorylase deficiency.

The present report describes the histochemical and biochemical findings of biopsied muscles in a 26-year-old male with myophosphorylase deficiency. Histochemical analysis of the first biopsy specimen revealed that the phosphorylase activity was absent, corresponding to an absent band at 94,000 Da on the basis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Histochemically the second biopsy specimen showed a partial phosphorylase activity of type 2B fibers, corresponding to a weakly staining band at 94,000 Da on the basis of SDS-PAGE. The present study supports the hypothesis that myophosphorylase deficiency is essentially a single gene disorder, characterized by absence or marked reduction of the myophosphorylase protein.

Adult↗
PubMed1989

An assay method for ganglioside synthase using anion-exchange chromatography.

A rapid procedure which is based on combined ion-exchange chromatography and solubility was established for determination of the activity of ganglioside synthases and cerebroside sulfotransferase. The procedure consists of selective elution of radiolabeled reaction products (acidic glycolipids) freed from labeled precursors and breakdown products on a DEAE-Sephadex column and of direct radioassay of the products in the eluate. Monosialogangliosides were eluted from the column with 40 mM ammonium acetate (AcONH4) in methanol, cerebroside sulfate with 90 mM AcONH4 in methanol, and disialogangliosides with 40 mM AcONH4 in isopropanol/n-hexane/water (55/20/19, v/v/v). The established procedure is simple, reproducible, and economical. Using rat Golgi membrane as enzyme source the recovery rate of the products was over 95%.

Animals↗
PubMed1987

[A case of extraorbital sebaceous carcinoma].

A case of sebaceous carcinoma of the forehead of a 77-year-old male is reported and discussed and included in a review of all such cases reported in Japan. The patient had a round erosion on the right forehead that had caused itching for 15 months. An excisional biopsy of that lesion disclosed a malignancy and a subsequent wide excision was performed. The tumor recurred several times after excision and partially effective radiation therapy. The patient finally died of aspiration pneumonia 3 years after the first operation. An autopsy revealed that he had a recurrent sebaceous carcinoma extending to the periosteum of the right temporal bone and a solitary pulmonary metastasis.

Adenocarcinoma↗