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Biomedical subjects

T Adachi

Publications and source records attributed to T Adachi.

At least 199 records · Page 11Linked to original sources
PubMed1998

Contraction properties of the superior pharyngeal constrictor muscle.

OBJECTIVE: The mechanical contraction property of the superior pharyngeal constrictor (PC) muscle was analyzed and compared with the levator veli palatini (LVP) muscle. DESIGN: Twenty adult dogs anesthetized with sodium pentobarbital were used. RESULTS: The isometric contraction curves of LVP and PC were recorded after direct electric stimulation to each muscle. The contraction time of isometric twitch contraction of the superior PC muscles was 30.3+/-5.25 msec, and the half relaxation time was 22.97+/-5.44 msec. The summation curve was observed at a stimulus frequency above 20 Hz of a repetitive pulse stimulus frequency of 85 Hz. CONCLUSIONS: The mechanical contraction properties of the PC muscle are similar to those of the LVP, but with more aspects that are characteristic of a fast twitch muscle.

Animals↗
PubMed1998

Aggregation independent of N-cadherin and neural cell adhesion molecule on quail myoblasts transformed with temperature-sensitive Rous sarcoma virus.

Quail myoblasts transformed with the temperature-sensitive mutant of Rous sarcoma virus (QM-RSV cells) differentiate temperature-sensitively. At 41 degrees C, the cells begin to fuse after about 15-18 h and form multinucleated myotubes, whereas, at 35.5 degrees C, the cells proliferate. Tyrosine-phosphorylation relates to this temperature-sensitive differentiation. In the course of the investigation of QM-RSV cells, when QM-RSV cells were dissociated with EDTA and shaken in DMEM, the aggregation activity was detected. This activity was expressed on the cells cultured at 41 degrees C, but not at 35.5 degrees C. For detailed characterization of the aggregation, cells from which cadherin and/or neural cell adhesion molecule (NCAM) were removed by trypsin treatment were used. It was then observed that temperature-sensitive and calcium-dependent aggregation activity was expressed on the cells treated with trypsin and EDTA (TE-cells), although the TE-cells did not retain either aggregation molecule. The aggregation activity began to be expressed at 2-4 h after temperature shift and increased with the differentiation. The expression of the activity related to the tyrosine-phosphorylation of some protein. The aggregation of TE-cells was completely inhibited by D(+)-mannose, D(+)-glucose, and N-acetyl-D-glucosamine, but D(+)-galactose did not affect the aggregation. Thus, the present results suggest that the aggregation of mannose specific C-type animal lectin recognized on TE-cells relates to the early stage of the differentiation of QM-RSV cells.

Animals↗
PubMed1998

[Association between social environment and aging of the brain: evaluation with the event-related potential P300].

PURPOSE AND METHODS: To investigate the association between social environment and aging of the brain, we studied P300 event-related evoked potentials in 95 normal elderly subjects living in different social environments. The subjects were divided into two groups: 22 healthy people living in old-age homes (average age 76.5 +/- 5.6 years, average Hasegawa Dementia Scale-Revised 27.4 +/- 2.5), and 93 healthy people living in their own homes (average age 74.1 +/- 5.4 years, average Hasegawa Dementia Scale-Revised 28.3 +/- 2.3). Target and Novelty P300 were recorded by using an auditory oddball paradigm. There were no differences in risk factors for strokes or in findings on magnetic resonance imaging between the two groups. RESULTS: Cognitive function (Okabe's Score and Koh's Block Design Test) were lower in those living in an old-age home than in those living in their own homes. Both target and novelty N100 examinations showed no significant differences in amplitude or latencies between the two groups. However, P300 latencies were larger among those living in an old-age home than among those living in their own homes; P300 amplitudes in the two groups were similar. Those living in an old-age home also had greater age-associated declines in function, as shown by longer latencies in target P300 than in novelty P300. CONCLUSION: Social-environmental factors are closely associated with the aging of the brain.

Aged↗
PubMed1998

Characterization of thiamin-binding protein from buckwheat seeds.

A thiamin-binding protein from buckwheat (Fagopyrum esculentum Moench) seeds gave two bands of 56-and 50-kDa in the absence of 2-mercaptoethanol and a single band of 25-kDa in the presence of 2-mercaptoethanol on sodium dodecylsulfate gel electrophoresis. These results indicate that the protein consists of polypeptides linked by disulfide bond(s). The protein isolated from buckwheat seeds did not have immunological homology with the thiamin-binding proteins from rice seeds and sesame seeds. However, the binding of the protein to thiamin was inhibited by the modification of the carboxyl residues in the protein as well as that of the thiamin-binding protein from rice seeds. These results suggest that the thiamin-binding protein from buckwheat seeds differ from those from rice seeds and sesame seeds as to subunit structure or immunological properties, but resembles them in the mechanism of binding thiamin.

Carrier Proteins↗
PubMed1998

Thiamin-binding protein from sunflower seeds.

A thiamin-binding protein was isolated from sunflower seeds. Its molecular mass was estimated to be 230 kDa by gel filtration. The protein was suggested to be composed of six subunits, which consisted of polypeptides linked by disulfide bond(s). The protein contained a large amount of glutamine or glutamic acid (19.9 mol%) and asparagine or aspartic acid (11.1 mol%). The levels of tryptophan and valine in the protein were low. These properties of the thiamin-binding protein were similar to those of helianthinin. Optimum pH for the thiamin-binding activity of the protein was 8.0 to 9.0. The thiamin-binding activity was not inhibited by thiamin monophosphate, thiamin pyrophosphate, oxythiamin, or pyrithiamin. These properties of the thiamin-binding protein from sunflower seeds were similar to those from buckwheat seeds, but not to those from rice seeds and sesame seeds.

Asparagine↗
PubMed1998

Correlation of prognosis of breast cancer patients and expression of Ley which acts as a cofactor of tumor procoagulant.

Association between Ley expression and prognosis of breast cancer was investigated using monoclonal antibody (MoAb) FS01, which recognizes Ley as an epitope, inhibits the procoagulant activity of cancer cell-derived coagulating activity 1 (CCA-1). Expression intensity and procoagulant activity of CCA-1, tissue factor and HLA-DR on breast cancer cell lines were also examined. Immunohistochemical staining of Ley was performed on primary lesions of 223 breast cancer patients who received absolute curative operation. Flow cytometric analysis and clot timer was used to detect expression and activity of each procoagulant on cancer cell lines. The Ley expression was 73.5%, and no significant relation was observed between clinicopathological factors and intensity of Ley expression. The group showing strong Ley positivity had a significantly poorer prognosis than the Ley-negative group in 5-year disease-free survival (p=0.019). Multivariate analysis using the Cox's proportional hazards' regression model showed that Ley expression is an independent prognostic factor (p=0.018), following tumor size and lymph node metastasis. Ley expression on cancer cell surface is higher than tissue factor and HLA-DR. FS01 and anti-tissue factor MoAb inhibited the coagulating activity of tissue factor-expressing lines, but no cells were inhibited by staphylococcal enterotoxin A, which is known to inhibit the coagulating activity of HLA-DR. CCA-1 and tissue factor plays a important role in the blood coagulating activity of breast cancer cell lines. Breast cancer patients are thought to have a poor prognosis because Ley expression on the surface of the cancer cell induces blood coagulation via CCA-1.

Aged↗
PubMed1998

[Job satisfaction of sales people: a covariance structure analysis of the motivational process].

The purpose of this study was to investigate the relationship among job satisfaction, job involvement, and work motivation. Two hundred thirty-nine sales people completed a questionnaire of job satisfaction (pay, interpersonal relationship, work environment, and job content), job involvement, and work motivation. The data were analyzed with covariance structure analysis, and the model, which was constructed beforehand, fitted well with relatively high GFI and AGFI. Results of the analysis showed that job satisfaction, in terms of pay and interpersonal relationship, influenced job content satisfaction, which in turn indirectly influenced work motivation, mediated through job involvement. In addition, the data indicated that satisfaction with customer relationship was strongly related to job content satisfaction in the sample of sales people.

Adult↗
PubMed1998

[A case of hereditary motor and sensory neuropathy with pyramidal tract sign, optic nerve atrophy and mental retardation].

The patient was a 61-year-old man who suffered from gait disturbance since childhood. He also had mental retardation. Gait disturbance was slowly progressive. His mother, sister, brother and son of his sister suffered from gait disturbance. On neurological examination, he showed mental retardation, optic nerve atrophy and neural deafness. He also showed severe muscle atrophy and weakness of bilateral lower limbs associated with pes cavus. Muscle tonus of lower limbs and patellar tendon reflex were increased bilaterally. Achilles tendon reflex was absent. Babinski and Chaddock signs were positive. Superficial and deep sensations were almost normal. There were no cerebellar signs. Blood chemistry was normal. On nerve conduction studies, motor nerve conduction velocity of the upper limbs was normal and that of the posterior tibial nerve was decreased; right 36.0m/sec, left 29.7m/sec. Sensory nerve conduction velocity of the median nerve was slightly decreased; right 36.5m/sec, left 45.2m/sec and sural nerve did not respond to electric stimuli. On sural nerve biopsy, the density of myelinated fibers was severely decreased. Onion bulb formation was not observed. We classified this case as hereditary motor and sensory neuropathy (HMSN) type II based on nerve conduction studies and findings from sural nerve biopsy. HMSN with pyramidal tract sign has been classified as type V and HMSN with optic nerve atrophy as type VI. This case had characteristic symptoms as type V and VI. Histopathological findings of HMSN type V and VI have not been established yet. This case might provide an important clue for classification of HMSN.

Hereditary Sensory and Motor Neuropathy↗
PubMed1998

[Postoperative management of the preserved rectal segment in patients with familial polyposis: the use of 5-fluorouracil suppositories and green tea extract to inhibit tumor growth].

We report the clinical details of seven patients with familial polyposis. They underwent subtotal colectomy with ileorectostomy, and were treated with 5-fluorouracil suppositories and green tea extract after surgery. Some regression of the polyps in the preserved rectal segment was observed, and no rectal cancer developed in any of these patients.

Adenomatous Polyposis Coli↗
PubMed1998

[Clinical evaluation of intermittent hepatic arterial infusion therapy for metastatic liver tumor of gastric and colorectal cancer].

Eleven patients with liver metastasis from gastric cancer were treated by intermittent arterial infusion using OK-432 and recombinant IL-2 in combination with anticancer drugs. The direct effects for liver metastasis were PR 3 (response rate 30%), MR 2, NC 3, PD 1 and NE 1. Papillary adenocarcinoma showed a highly effective rate. The mean survival period was 326 days and the 50% survival period was 318 days. Out of 4 patients who underwent surgical resection for metastatic liver tumor, one showed recurrence, and the other is now healthy without any sign of recurrence for 8 years after the operation. In 7 patients with liver metastasis from colorectal cancer, intermittent arterial infusion therapy using Leucovorin, CDDP and 5-FU was performed. The direct effects were CR 2, PR 1, MR 1, PD 2, NE 1; the mean survival period was 478 days, and the 50% survival period 556 days. Out of 8 patients who underwent liver resection for metastasis, all patients remained alive for 687 mean survival days without liver recurrence. No severe side effects were noted in either therapy.

Adenocarcinoma, Papillary↗
PubMed1998

[Clinical evaluation of chemiluminescence immunoassay PSA (ACS-PSA) for detection of prostate cancer].

Serum prostate specific antigen (PSA) levels were measured using an ACS-PSA kit in 147 systematic biopsy cases (61 with prostate cancer (PC)) and 96 transurethral resection of prostate (TUR-P) cases (2 with PC). In the 147 biopsy cases, the sensitivity for PSA using 3.0 and 10.0 ng/ml as cut-off values was 91.8 and 90.2%, while the specificity was 9.30 and 30.2%, respectively. The sensitivity for PSAD (A) (calculated by transabdominal ultrasound) using 0.25 and 0.5 ng/ml/cm3 as cut-off values was 91.8 and 90.2%, while the specificity was 22.1 and 50.0%, respectively. These data indicated that PSAD (A) provided better information for detecting PC than PSA alone. No statistical difference was found between PSAD (A) and PSAD (R) (calculated by transrectal ultrasound) in the utility of detecting PC. PSA below 15.0 ng/ml was seen in sixteen patients with PC. Five of these sixteen patients had a PSA level of < 3.0, and they underwent prostate biopsy based on the abnormality by digital rectal examination (DRE). The other eleven patients had PSAD (A) level of > 0.3 ng/ml/cm3. In all 243 cases, PC was not found in the 49 patients (PSA < 3.0 ng/ml) or 91 patients (PSAD (A) < 0.25 ng/ml/cm3) who had no abnormal findings by DRE and transabdominal ultrasonography. These results suggested a criterion in the use of the ACS-PSA kit for the indication of prostate biopsy and TUR-P.

Aged↗
PubMed1997

PAF analogues capable of inhibiting PAF acetylhydrolase activity suppress migration of isolated rat cerebellar granule cells.

Intracellular platelet-activating factor (PAF) acetylhydrolase in the bovine brain is a heterotrimeric enzyme composed of alpha1, alpha2 and beta subunits. The trimeric enzyme may be involved in neural cell migration, since the human homolog of the non-catalytic beta subunit is a product of the LIS-1 gene which is a causative gene for Miller-Dieker syndrome. Miller-Dieker syndrome is a form of lissencephaly that is characterized by widespread agyria of the brain and defects of neuronal cell migration. In the present study, we attempted to determine whether the catalytic activity of either the alpha1 or alpha2 subunit is required for the regulation of granule cell migration. Granule cells prepared from rat cerebellum at postnatal day 0 express all three subunit proteins (alpha1, alpha2 and beta) as determined by western blotting. Granule cell migration, which was observed in vitro on a layer coated with laminin, was effectively blocked by PAF analogs which showed PAF receptor-antagonistic activity (CV-6209 and CV-3988) and PAF receptor-agonistic activity (carbamoyl PAF). These PAF analogs also inhibited the activity of bovine brain PAF acetylhydrolase. Cell migration was restored when the inhibitors were removed by washing the treated cells with buffer, indicating that the inhibitory effect of PAF analogs is reversible. Structurally-unrelated PAF antagonists (SM-12502, TCV-309 and YM-264), none of which showed any appreciable inhibitory activity against PAF acetylhydrolase, did not block granule cell migration under the same conditions. It is suggested that the catalytic activity of PAF acetylhydrolase may play a crucial role in neural cell migration.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1997

Prolonged activation of phospholipase D in Chinese hamster ovary cells expressing platelet-activating-factor receptor lacking cytoplasmic C-terminal tail.

The mechanism and role of phospholipase D (PLD) activation by platelet-activating factor (PAF) were examined with Chinese hamster ovary cells stably expressing wild-type PAF receptor (WT-H cells) and truncated PAF receptor lacking the C-terminal cytoplasmic tail (D-H cells). Treatment of D-H cells with PAF resulted in the rapid formation of Ins(1,4,5)P3, which was followed by a sustained phase for more than 10 min. In these cells, PAF-induced PLD activation lasted for more than 20 min. In contrast, PLD activation in WT-H cells was transient. PAF stimulation caused the biphasic formation of 1,2-diacylglycerol (DG) in both types of cell. The first phase was rapid and transient, coinciding with the Ins(1,4,5)P3 peak. The second sustained phase of DG formation was attenuated by butanol, which produces phosphatidylbutanol at the expense of phosphatidic acid (PA) by transphosphatidylation activity of PLD, and by propranolol, a selective inhibitor for PA phosphohydrolase catalysing the conversion of PA into DG. The DG level returned nearly to basal at 20 min after PAF stimulation in WT-H cells, whereas in D-H cells the elevated DG level was sustained for more than 20 min. The profile of translocation of protein kinase Calpha (PKCalpha) to membrane was similar to that of DG formation. In WT-H cells, PKCalpha was transiently associated with membranes and then returned to the cytosol. However, in D-H cells PKCalpha was rapidly translocated to and remained in membranes for more than 20 min. Butanol suppressed this sustained translocation of PKCalpha. Furthermore the mRNA levels of c-fos and c-jun by PAF in WT-H cells were much lower than those in D-H cells. Propranolol and butanol at concentrations that inhibited the formation of DG suppressed the PAF-induced mRNA expression of c-fos and c-jun. Taken together, the prolonged PLD activation in D-H cells confirmed a primary role for phospholipase C/PKC in PLD activation by PAF. Furthermore the results obtained here suggest that sustained PLD activation in turn leads to chronic activation and membrane translocation of PKCalpha, which might play an important role in the expression of c-fos and c-jun.

1-Butanol↗
PubMed1997

Increased sensitivity of gastric cancer cells to natural killer and lymphokine-activated killer cells by antisense suppression of N-acetylgalactosaminyltransferase.

UDP-N-acetylgalactosamine:polypeptide N-acetylgalactosaminyltransferases (GalNAc transferases) catalyze the initial reaction in O-linked (mucin type) oligosaccharide biosynthesis. To attempt to inhibit the synthesis of O-glycan, we transfected antisense cDNA of GalNAc transferase type 1 (GalNAc-T1) into a human gastric cancer cell line, JRST. A decreased expression of GalNAc-T1 at the level of both mRNA and protein was observed in the resultant transfectants. They demonstrated a significantly increased sensitivity to NK and lymphokine-activated killer cells in vitro compared with parental cells and mock transfectants. Although there was no significant difference in in vitro cell proliferation among parental cells, mock transfectants, or antisense transfectants, the in vivo growth rate of antisense transfectants using SCID mice was clearly lower than that of parental cells and mock transfectants. Furthermore, the treatment of mice with anti-asialo-G(M1) Ab abolished this growth-inhibitory effect of antisense transfection. From these results, we conclude that antisense suppression of GalNAc-T1 could increase the sensitivity of tumor cells to NK and lymphokine-activated killer cells, suggesting that this strategy may be of use as a new immunogene therapy.

Animals↗
PubMed1997

Src homology 2 protein tyrosine phosphatase (SHPTP2)/Src homology 2 phosphatase 2 (SHP2) tyrosine phosphatase is a positive regulator of the interleukin 5 receptor signal transduction pathways leading to the prolongation of eosinophil survival.

Interleukin-5 (IL-5) regulates the growth and function of eosinophils. It induces rapid tyrosine phosphorylation of Lyn and Jak2 tyrosine kinases. The role of tyrosine phosphatases in IL-5 signal transduction has not been investigated. In this study, we provide first evidence that SH2 protein tyrosine phosphatase 2 (SHPTP2) phosphotyrosine phosphatase plays a key role in prevention of eosinophil death by IL-5. We found that IL-5 produced a rapid activation and tyrosine phosphorylation of SHPTP2 within 1 min. The tyrosine phosphorylated SHPTP2 was complexed with the adapter protein Grb2 in IL-5-stimulated eosinophils. Furthermore, SHPTP2 appeared to physically associate with beta common (betac) chain of the IL-5 receptor (IL-5betacR). The association of SHPTP2 with IL-5betacR was reconstituted using a synthetic phosphotyrosine-containing peptide, betac 605-624, encompassing tyrosine (Y)612. The binding to the phosphotyrosine-containing peptide increased the phosphatase activity of SHPTP2, whereas the same peptide with the phosphorylated Y612--> F mutation did not activate SHPTP2. Only SHPTP2 antisense oligonucleotides, but not sense SHPTP2, could inhibit tyrosine phosphorylation of microtubule-associated protein kinase, and reverse the eosinophil survival advantage provided by IL-5. Therefore, we conclude that the physical association of SHPTP2 with the phosphorylated betac receptor and Grb2 and its early activation are required for the coupling of the receptor to the Ras signaling pathway and for prevention of eosinophil death by IL-5.

Adaptor Proteins, Signal Transducing↗
PubMed1997

Comparison of myocardial contrast echocardiography and coronary angiography for assessing the acute protective effects of collateral recruitment during occlusion of the left anterior descending coronary artery at the time of elective angioplasty.

To assess the immediate change in collateral flow distribution within the occluded myocardium and the acute protective effects on myocardial ischemia after coronary occlusion, myocardial contrast echocardiography (MCE) was performed in 15 patients with normal left ventricular function undergoing elective coronary angioplasty of the left anterior descending artery, and the results were compared with those obtained from coronary angiography (CA). The sonicated or nonsonicated contrast material was injected into the right coronary artery before and during coronary occlusion and collaterals were graded on a 4-point scale (none = 0 to good = 3). Development of subjective anginal symptoms, ST-segment shift and wall motion abnormality during coronary occlusion were graded on a 4-point scale (none = 0 to severe = 3). Both MCE and CA detected a significant development in collateral flow during coronary occlusion. There was no significant correlation between MCE and CA collateral grades before or during coronary occlusion. The collateral flow assessed with MCE was inversely but significantly correlated with development of subjective anginal symptoms (r(s) = -0.70, p <0.01), ST-segment shift (r(s) = -0.78, p < 0.005) or wall motion abnormality (r(s) = -0.91, p < 0.001) during coronary occlusion. In contrast, the angiographic collateral flow was not correlated with development of anginal symptoms (r(s) = -0.46, p = 0.10), ST-segment shift (r(s) = -0.41, p = 0.14), or wall motion abnormality (r(s) = -0.26, p = 0.35). The present study suggested that the acute protective effects of coronary collaterals during coronary occlusion were closely associated with myocardial perfusion rather than the angiographic epicardial collateral vessel filling, and thus MCE was useful in assessing the acute protective effects of coronary collaterals during coronary occlusion.

Aged↗
PubMed1997

Stage specific expression of milk fat globule membrane glycoproteins in mouse mammary gland: comparison of MFG-E8, butyrophilin, and CD36 with a major milk protein, beta-casein.

The expression of mouse milk fat globule membrane (MFGM) glycoproteins, MFG-E8, butyrophilin, CD36 was analyzed by Northern blot analyses. MFG-E8 and butyrophilin mRNAs were specifically detected in the mammary gland of lactating mice, whereas CD36 mRNA was detected in the heart and lung as well as in the mammary gland of lactating mice. The mRNAs of the three MFGM glycoproteins accumulated at mid-lactation were about 2-10-times as much as those of the early and late gestation stages, whereas beta-casein mRNA accumulation was dramatically increased; the mRNA at mid-lactation was no less than 40-times as much as that before lactation. In mouse mammary epithelial cell lines, HC11 and COMMA-1D, only a slight or almost no enhancement for the expression of MFG-E8, butyrophilin and CD36 mRNAs was induced simply by the treatment with the lactogenic hormones such as prolactin, insulin and dexamethasone, whereas the beta-casein mRNA expression was remarkably enhanced only by that treatment. Furthermore, while the beta-casein protein was constantly detected in milk throughout the lactation stage, the content of MFG-E8 and butyrophilin proteins increased during the lactation with an increase in the milk fat content. These results suggest that the stage-specific expression of milk fat globule membrane glycoproteins in mammary epithelial cells is regulated in a similar but not necessarily identical mechanism to that of a major milk protein, beta-casein.

Animals↗