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Biomedical subjects

T Moriyama

Publications and source records attributed to T Moriyama.

At least 91 records · Page 5Linked to original sources
PubMed1999

The effects of fabric air permeability and moisture absorption on clothing microclimate and subjective sensation in sedentary women at cyclic changes of ambient temperatures from 27 degrees C to 33 degrees C.

The present paper aimed at learning the effects of two different levels of air permeability and moisture absorption on clothing microclimate and subjective sensation in sedentary women. Three kinds of clothing ensemble were investigated: 1) polyester clothing with low moisture absorption and low air permeability (A clothing); 2) polyester clothing with low moisture absorption and high air permeability (B clothing); and 3) cotton clothing with high moisture absorption and high air permeability (C clothing). After 20 min of dressing time, the room temperature and humidity began to rise from 27 degrees C and 50% rh to 33 degrees C and 70% rh over 20 min, and it was maintained for 30 min (Section I); it then began to fall to 27 degrees C and 50% rh over 20 min, and it was maintained there for 20 min (Section II). The subject sat quietly on a chair for 110 min. The main findings are summarized as follows: 1) The clothing surface temperature was significantly higher in C clothing than in B clothing during section I, but it was significantly higher in B clothing than in C clothing during section II. 2) Although the positive relationship between the microclimate humidity and forearm sweat rate was significantly confirmed in all three kinds of clothing, the microclimate humidity at the chest for the same sweat rate was lower in C clothing than in A and B clothing. These results were discussed in terms of thermal physiology.

Adult↗
PubMed1998

Degradation of HMG-CoA reductase in vitro. Cleavage in the membrane domain by a membrane-bound cysteine protease.

We have recently shown that the endoplasmic reticulum (ER) membrane protein, 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, is cleaved in isolated membrane fractions enriched for endoplasmic reticulum. Importantly, the cleavage rate is accelerated when the membranes are prepared from cells that have been pretreated with mevalonate or sterols, physiological regulators of the degradation process in vivo (McGee, T. P., Cheng, H. H., Kumagai, H., Omura, S., and Simoni, R. D. (1996) J. Biol. Chem. 271, 25630-25638). In the current study, we further characterize this in vitro cleavage of HMG-CoA reductase. E64, a specific inhibitor of cysteine-proteases, inhibits HMG-CoA reductase cleavage in vitro. In contrast, lactacystin, an inhibitor of the proteasome, inhibits HMG-CoA reductase degradation in vivo but does not inhibit the in vitro cleavage. Purified ER fractions contain lactacystin-sensitive and E64-insensitive proteasome activity as measured by succinyl-Leu-Leu-Val-Tyr-7-amino-4-methylcoumarin hydrolysis. We removed the proteasome from purified ER fractions by solubilization with heptylthioglucoside and observed that the detergent extracted, proteasome-depleted membrane fractions retain regulated cleavage of HMG-CoA reductase. This indicates that ER-associated proteasome is not involved in degradation of HMG-CoA reductase in vitro. In order to determine the site(s) of proteolysis of HMG-CoA reductase in vitro, four antisera were prepared against peptide sequences representing various domains of HMG-CoA reductase and used for detection of proteolytic intermediates. The sizes and antibody reactivity of the intermediates suggest that HMG-CoA reductase is cleaved in the in vitro degradation system near the span 8 membrane region, which links the N-terminal membrane domain to the C-terminal catalytic domain of the protein. We conclude that HMG-CoA reductase can be cleaved in the membrane-span 8 region by a cysteine protease(s) tightly associated with ER membranes.

Acetylcysteine↗
PubMed1998

Up-regulation of vascular endothelial growth factor induced by hepatocyte growth factor/scatter factor stimulation in human glioma cells.

Recent findings suggest that hepatocyte growth factor/scatter factor (HGF/SF) contributes to the malignant progression of human gliomas. We investigated the effect of HGF/SF on vascular endothelial growth factor (VEGF) expression of c-Met/HGF receptor-positive human glioma cell lines. Treatment of the glioma cells with various concentrations of HGF/SF resulted in an enhanced secretion of VEGF proteins accompanying increased transcription of VEGF mRNA in a dose-dependent fashion. Since malignant gliomas frequently co-express HGF/SF and its receptor, these results suggest that HGF/SF could act as an indirect angiogenic factor through autocrine induction of VEGF expression and secretion in malignant gliomas.

Endothelial Growth Factors↗
PubMed1998

Comparative analysis of expression of hepatocyte growth factor and its receptor, c-met, in gliomas, meningiomas and schwannomas in humans.

Expression of hepatocyte growth factor (HGF) and c-met, a proto-oncogene that encodes a receptor for HGF, was examined in 45 cases of human primary intracranial tumors by means of RT-PCR. In gliomas, HGF and c-met mRNAs were preferentially expressed in high-grade tumors. Co-expression of both genes was observed in glioblastomas (6/15) and in one anaplastic astrocytoma (1/5) but not in low-grade astrocytomas (0/3). By contrast, the c-met gene was consistently expressed in meningiomas (12/14) and schwannomas (8/8). The presence of c-Met protein was confirmed in the tumor cells of glioblastoma, meningioma and schwannoma by immunohistochemical staining. Moreover, all of the schwannoma cases co-expressed the HGF gene. These observations suggest that HGF/c-met expression is somehow related to the disease progression in gliomas, whereas c-Met protein might have an important fundamental biological role in meningioma and schwannoma. Moreover, since all of the schwannoma cases concomitantly expressed the ligand (HGF) and the receptor (c-met) genes, HGF may act in an autocrine fashion in schwannoma.

Astrocytoma↗
PubMed1998

Application of SPET using technetium-99m sestamibi in brain tumours and comparison with expression of the MDR-1 gene: is it possible to predict the response to chemotherapy in patients with gliomas by means of 99mTc-sestamibi SPET?

Technetium-99m sestamibi (MIBI) is thought to be passively taken up by metabolically active tumour cells and effluxed from them by P-glycoprotein (Pgp). This 170-kDa membrane-bound protein, encoded by the MDR-1 gene, acts as an energy-dependent efflux pump for several antineoplastic agents, resulting in multidrug resistance. For this reason, it is of interest whether the tumour's response to chemotherapy can be predicted by MIBI single-photon emission tomography (SPET). In this study, MIBI SPET was compared with thallium-201 (Tl) SPET using magnetic resonance imaging as a guide in 16 patients with untreated brain tumours [ten glioblastomas (GBs), two anaplastic astrocytomas (AAs), two low-grade gliomas (LGASs) and two metastatic brain tumours) and in four patients who had received treatment for with brain tumours (two GBs, two AAs). In addition, we investigated the expression of the MDR-1 gene and its product Pgp in the same patients, and compared the results with MIBI SPET findings. MIBI, as well as Tl, was highly accumulated and retained in the enhanced region of malignant gliomas. In addition, MIBI SPET yielded sharp and well-contrasted images, and the margin of the tumour was more clearly defined than with Tl SPET due to a good signal-to-noise ratio. Follow-up MIBI SPET in patients who had received therapy showed marked uptake in a patient with malignant transformation, who deteriorated clinically. Patients with no uptake on MIBI SPET showed no sign of recurrence. Semiquantitative analysis of untreated patients showed a relationship between the early uptake index (UI, ratio of average count/pixel in the lesion to that in the contralateral area on early images) and the degree of malignancy (early UI = 1.08+/-0.06 in LGASs, 4.10+/-0.84 in AAs, 5.71+/-3.47 in GBs, and 7.52+/-1.52 in metastatic brain tumours). The retention index (RI, ratio of delayed to early UI) of MIBI was significantly lower than that of Tl in metastatic brain tumours (P<0.05), but not in malignant gliomas. Histological and biological investigation of gliomas showed that the MDR-1 gene and its product Pgp were expressed only in normal endothelial cells and not in tumour cells or proliferating endothelial cells; Pgp tended to decrease as the degree of malignancy rose. Hence, the presence of Pgp and the grade of malignancy were inversely related in gliomas. By contrast, immunohistochemical study showed strong accumulation of Pgp in metastatic brain tumour cells. These histopathological findings and MIBI SPET findings are compatible with experimental data; MIBI was washed out by Pgp. The main cause of chemoresistance is probably not an increasing drug efflux by Pgp in gliomas. Thus, MIBI SPET is useful for detecting the active lesions, but may not be useful for predicting the response to chemotherapy in gliomas.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Activation of non-primary motor areas during a complex finger movement task revealed by functional magnetic resonance imaging.

We examined the brain activation induced by a complex finger movement task using functional magnetic resonance imaging (fMRI) with echo planar imaging (EPI). Imaging planes were set up for the observation of non-primary motor areas. Among five normal males examined, four subjects naive to the task showed activations in contralateral primary and supplementary motor areas and the ipsilateral superior anterior part of the cerebellar hemisphere. Also, the bilateral premotor areas and the contralateral ventrolateral nucleus of thalamus were occasionally activated. No changes were observed in the putamen and globus pallidus. The subject accustomed to the task showed activation in the narrow areas of the contralateral primary motor and supplementary motor and premotor areas but not in the cerebellum. These results suggest that fMRI has nearly the same degree of detectability to that of positron emission tomography (PET) in regard to motor functions.

Adult↗
PubMed1998

Isolation of genes identified in mouse renal proximal tubule by comparing different gene expression profiles.

An expression profile is a list based on a large scale sequencing of 1000 cDNA clones, showing the expressed genes and the abundance of their transcripts in a given cell or tissue (Okubo K et al: Nature Genet 2:173, 1992). We constructed an expression profile of mouse renal proximal tubules (PT) carefully isolated by microdissection in order to characterize its gene expression. Altogether 1000 clones were analyzed; there were 646 types of transcripts in PT, among which 196 were identical or homologous to the previously reported genes. The most abundant transcript was kidney-androgen regulated protein. By comparing the expression profile of PT with those obtained from other sources, several genes were identified only in PT. They included known transcripts and transcripts that were not homologous to the known genes. Three (GS4001, 3991, and 4059) of the non-homologous genes were analyzed by Northern blotting and in situ hybridization, and GS4001 and 4059 were predominantly expressed in the kidney, whereas GS3991 was detected in the liver as well as in the kidney. The sequence analysis of the full-size cDNAs demonstrated that GS4001 was a new member of aspartic proteinases and GS4059 was a novel gene. It also revealed that GS3991 was a mouse homologue of SA gene known to be expressed in PT. The expression profile of mouse PT and its comparison with those of other tissues and cells provide an alternate way of isolating genes predominantly expressed in PT, and also provides probes to study the molecular mechanisms of gene expression in the kidney.

3T3 Cells↗
PubMed1998

Up-regulation of HSP47 in the mouse kidneys with unilateral ureteral obstruction.

BACKGROUND: Unilateral ureteral obstruction (UUO) is a well established experimental model of renal injury leading to interstitial fibrosis. The molecular and cellular mechanism(s) of interstitial fibrosis in UUO are beginning to be elucidated. In the progression of interstitial fibrosis in UUO, up-regulation of collagen synthesis is commonly observed. HSP47 is a collagen-binding stress protein and is thought to be a collagen-specific molecular chaperone, which plays a pivotal role during the biosynthesis and secretion of collagen molecules in the endoplasmic reticulum. The synthesis of HSP47 has been demonstrated to always parallel that of collagen in physiological and pathophysiological conditions. It is well recognized that renin-angiotensin system (RAS) is enhanced in the setting of UUO and that enhanced RAS has been implicated in the pathogenesis of interstitial fibrosis in the obstructed kidneys. METHODS: To investigate the role of HSP47 in the progression of interstitial fibrosis in mouse UUO, the expression of HSP47 was examined by Northern blotting, immunohistochemistry and in situ hybridization in the obstructed kidneys. To test the possible involvement of enhanced RAS on the HSP47 expression, we examined the effects of lisinopril, an angiotensin converting enzyme inhibitor, on interstitial fibrosis. HSP47 and type I collagen mRNA expression. RESULTS: By Northern blot analysis, HSP47 mRNA was significantly up-regulated at 12 hours (about twice that of sham operated kidneys) after the onset of ureteral obstruction, further increased and stayed at the increased level until seven days (about 8 times that of sham operated kidneys). HSP47 mRNA and protein expression were observed in the periglomerular and peritubular interstitial regions of the obstructed kidneys. Distribution of smooth muscle alpha actin and type I collagen immunoreactivity were similar to the HSP47 distribution pattern, suggesting that HSP47 was up-regulated in the myofibroblasts. Lisinopril ameliorated the expansion of cortical interstitium in the obstructed kidneys at four and seven days after ureteral obstruction. HSP47 mRNA expression was suppressed at four and seven days, whereas type I collagen mRNA was suppressed only at seven days after the onset of ureteral obstruction. CONCLUSIONS: These results demonstrate the early and persistent up-regulation of HSP47 during the progression of interstitial fibrosis in mouse UUO kidneys, and further suggest the potential role of HSP47 in the pathogenesis of interstitial fibrosis in the obstructed kidneys. Partial suppression of HSP47 mRNA expression by lisinopril at day 4 and day 7 after ureteral obstruction suggests that there are other immediate trigger(s) that induce the HSP47 mRNA expression. Identification of the molecular mechanism of HSP47 induction during UUO may give an insight into the novel aspects of the molecular pathophysiology of interstitial fibrosis in obstructive nephropathy.

Actins↗
PubMed1998

Coffee consumption and decreased serum gamma-glutamyltransferase and aminotransferase activities among male alcohol drinkers.

BACKGROUND: Attention has long been drawn to the potentially harmful effects of coffee on health, however recent epidemiological studies have suggested unexpected, possibly beneficial effects of coffee against the occurrence of alcoholic liver cirrhosis and upon serum liver enzyme levels. METHODS: We examined the potential inverse association between coffee drinking and serum concentrations of gamma-glutamyltransferase (GGT) and aminotransferases, with special reference to interaction with alcohol consumption, in a cross-sectional study involving 12687 health examinees (7398 men and 5289 women) aged 40-69 years from over 1000 workplaces in Nagano prefecture in central Japan. Those who had a history of liver disease and/or serum aminotransferases exceeding the normal range were excluded. Possible confounding effects of alcohol consumption, body mass index, cigarette smoking, and green tea consumption were controlled through multivariate analyses. RESULTS: Increased coffee consumption was strongly and independently associated with decreased GGT activity among males (P trend < 0.0001); the inverse association between coffee and serum GGT was more evident among heavier alcohol consumers (P < 0.0001), and was absent among non-alcohol drinkers. Among females, however, coffee was only weakly related to lower GGT level. Similar inverse associations with coffee and interactions between coffee and alcohol intake were observed for serum aspartate aminotransferase and alanine aminotransferase. Intake of green tea, another popular source of caffeine in Japan, did not materially influence the liver enzyme levels. CONCLUSIONS: Our results suggest that coffee may inhibit the induction of GGT in the liver by alcohol consumption, and may possibly protect against liver cell damage due to alcohol.

Adult↗
PubMed1998

Enhanced glomerular expression of caldesmon in IgA nephropathy and its suppression by glucocorticoid-heparin therapy.

BACKGROUND: Activation and consequent phenotypic modulation of mesangial cells is considered to play a crucial role in the process of glomerular disease progression. Caldesmon, a calmodulin and actin-binding protein, is a molecular marker of the phenotypic change in smooth-muscle cells. SUBJECTS AND METHODS: We studied whether the expression of caldesmon in mesangial cells was enhanced in the process of IgA nephropathy and whether it would be a marker of mesangial activation indicating prognostic significance in specific disease states. We performed immunohistochemical staining with anticaldesmon and alpha-smooth-muscle actin (alpha-SMA) antibodies in 32 biopsy specimens from IgA nephropathy patients and analysed them quantitatively with a computer-aided manipulator. RESULTS: The glomerular expression of caldesmon was enhanced in IgA nephropathy patients. We compared caldesmon expression with composite histological scores (cell score and matrix score), clinical parameters and expressions of alpha-SMA. There was a statistically significant correlation between the caldesmon score and the histological scores (cell score and matrix score, P<0.0001, P<0.01 respectively). Patients showing a high intensity of caldesmon expression (defined as caldesmon score > or = 35; H-group) had significantly higher urinary protein excretion than those showing a low intensity of caldesmon expression (defined as caldesmon score < 35; L-group) (1.2 +/- 1.2 g/24 h vs 0.41 +/- 0.53 g/24 h, P<0.05). Caldesmon and alpha-SMA expression had a statistically significant correlation (P<0.000). Next, 13 patients were treated with glucocorticoid-heparin for 4-8 weeks and re-biopsies were performed. After the therapy, the caldesmon and alpha-SMA scores were significantly lower than those before the therapy (P<0.01). DISCUSSION: These results suggest that the expression of caldesmon in glomeruli is associated with the progression of IgA nephropathy, and that glucocorticoid heparin therapy may reverse the phenotype of mesangial cells during the disease process of glomerulonephritis.

Actins↗
PubMed1998

Bisegmental cervical interbody fusion using hydroxyapatite implants: surgical results and long-term observation in 70 cases.

UNLABELLED: Hydroxyapatite (HA) is the main constituent of bone mineral, and synthetic HA serves as a biocompatible and bioactive material. It permits bone growth on its surface and forms a union with the adjacent bone. OBJECT: The authors have developed implants made of porous HA, which they have used in more than 90 cases in the past 6 years to achieve cervical interbody fusion. The implants were designed to provide maximum durability, biomechanical stability, and alignment preservation and to be technically easy to use. The authors summarize their experience and results with the use of these implants. METHODS: The results of postoperative follow-up observation of 12 months or longer (mean 37.1 +/- 2.4 months) are available in 70 patients with underlying disease including: spondylosis, disc extrusion, ossification of the posterior longitudinal ligament (PLL), hypertrophy of the PLL, and trauma. The patients' ages at the time of surgery ranged from 22 to 83 years (mean 50.6 +/- 1.3 years). Flexion-extension radiographs and tomograms, obtained 6 and 12 months after surgery and every year thereafter, were used to demonstrate solid fusion in all cases. Dislocation of the implant occurred in three patients who were treated during the early portion of the series. At 6 to 12 months after surgery, encasement of the implant and formation of union were observed. Normal lordosis, if present prior to surgery, was maintained postsurgery. No neurological deterioration related to the site of fusion occurred during the period of observation. CONCLUSIONS: The authors conclude that satisfactory interbody fusion can be achieved by using HA implants, provided their design is appropriate and adequate surgical techniques are used.

Adult↗
PubMed1998

Prenatal diagnosis of fetal urogenital abnormalities with oligohydramnios by magnetic resonance imaging using turbo spin echo technique.

Turbo spin echo technique is a sequence that enables T2 weighted magnetic resonance (MR) images to be obtained in a few seconds. The purpose of this study is to evaluate the usefulness of this sequence in the prenatal diagnosis of fetal urogenital abnormalities associated with oligohydramnios, which make the ultrasound examination inconclusive. Two fetuses suspected of having prune belly syndrome and polycystic kidney on ultrasound examination were studied by MR imaging using turbo-spin echo method in utero. The images were compared with prenatal ultrasonography or post-mortem findings. In both fetuses, abnormalities were diagnosed correctly. This sequence is useful because it provides images of diagnostic quality in a very short scanning time.

Adult↗
PubMed1998

Two cases of primary pulmonary hypertension diagnosed during pregnancy.

Primary pulmonary hypertension (PPH) is a rare clinical entity with a high mortality in pregnancy, delivery and postpartum. This paper describes two clinical cases of PPH diagnosed in pregnancy with different severity and outcomes; Case 1 was diagnosed as PPH at 34 weeks of gestation with pulmonary arterial pressure of 60 mmHg and delivered successfully by cesarean section with uneventful postoperative course. Case 2 was diagnosed as PPH at 26 weeks of gestation with pulmonary arterial pressure of 120 mmHg and delivered by cesarean section but died on the 7th day after the operation because of serious and progressive pulmonary hypertension. Patients with primary pulmonary hypertension should avoid pregnancy because of the high mortality, although some cases including ours have been reported with positive outcome.

Adult↗
PubMed1998

Continuous and simultaneous cultivation of benthic food diatom Nitzschia sp. and abalone Haliotis sieboldii by using deep seawater.

By using low-temperature, clean, and nutrient-rich properties of deep seawater (DSW; seawater below the euphotic layer), a continuous and simultaneous cultivation system for a benthic food diatom, Nitzschia sp., and juvenile abalone was established. Cell suspension of Nitzschia sp. was added to a bioreactor made of acrylic pipe (7 cm diameter x 50 cm long) containing short vinyl tubes (2 cm diameter x 2 cm long) as substrata. DSW collected from 320 m depth at Muroto City, in Kochi Prefecture, Japan, was supplied to the reactor and incubated under natural light (ca. 6000 lux) with a continuous DSW flow rate of 40 turnovers per hour. After growing enough benthic diatoms in the reactor, juveniles of abalone, Haliotis sieboldii (shell length ca. 10-20 mm) were put into a reactor, and cultivated simultaneously with food diatoms in the continuous flow system. During the four-month incubation, 7-month-old abalone juveniles with a shell length of 12.4 (average) +/-0.2 (SD) mm were grown to 19.4 (+/-1.7) mm in the reactor. Daily growth rates of abalones were 50-110 µm/day. These results indicate that the continuous cultivation system with DSW supports the growth of juvenile abalone without any supply of seaweed until it grows to release size.

Journal Article↗