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Biomedical subjects

T Ide

Publications and source records attributed to T Ide.

At least 199 records · Page 11Linked to original sources
PubMed1995

Effects of a continuous infusion of dopamine on the ventilatory and carotid body responses to hypoxia in cats.

1. We investigated how a continuous infusion of dopamine (DA; 5 micrograms/kg per min), which is often used clinically, would affect the ventilation and carotid chemoreceptor neural activity in anaesthetized cats. 2. In anaesthetized, spontaneously breathing cats, tidal volume (VT) and respiratory frequency (f) were continuously monitored at five levels of inspired oxygen (PIO2 = 110, 130, 150, 170, 760 mmHg) during Da or saline infusion. VT and f were sampled for 1 min after 3 min exposure to each level of PIO2. Time control study was also performed. 3. DA infusion significantly lowered VT under both normoxia and hypoxia in seven of eight cats. Respiratory frequency was not affected by DA infusion. Depression of ventilation during post-hypoxic hyperoxia was augmented by DA infusion. Chemodenervation abolished the ventilatory response to hypoxia and DA did not further affect the ventilatory response to hypoxia. 4. In a second group of artificially ventilated cats, carotid chemoreceptor neural activity was recorded at five levels of arterial oxygen tension. DA infusion significantly depressed carotid chemoreceptor neural activity during normoxia and hypoxia in six of seven cats. 5. These findings suggest that changes in ventilation during low dosage of DA infusion closely correlate with carotid body neural output. A predominant effect of this dosage of DA (5 micrograms/kg per min) was depression in the ventilatory response to hypoxia due to an inhibition of carotid body neural output.

Anesthesia↗
PubMed1995

Calsequestrin is essential for the Ca2+ release induced by myotoxin alpha in skeletal muscle sarcoplasmic reticulum.

Myotoxin alpha (MYTX), a polypeptide toxin purified from the venom of prairie rattlesnakes (Crotalus viridis viridis), induced Ca2+ release from the heavy fraction of skeletal sarcoplasmic reticulum (HSR), using a Ca2+ electrode. The effect of MYTX was nearly abolished by pretreatment with ryanodine, an alkaloid-based Ca2+ channel blocker. In the stopped-flow experiments, MYTX increased the choline+ permeability of HSR in the presence of calsequestrin (CS). Single channel recording experiments showed that in the presence of CS, the channel currents were markedly enhanced by MYTX applied to the cis side, but not to the trans side. However, in the absence of CS, MYTX failed to cause the excitatory effect in both the experiments. These results suggest that CS is essential for MYTX-induced Ca2+ release through the Ca2+ release channels in skeletal HSR.

Adenosine Triphosphate↗
PubMed1995

Thyroid dysfunction induced by interferon therapy for the treatment of hepatitis type C. A report of 4 cases.

We describe 4 patients with onset or aggravation of thyroid dysfunction induced by interferon (IFN) treatment of hepatitis type C. All 4 patients were females; 2 had hyperthyroidism and 2 had hypothyroidism during or after IFN therapy. The onset or aggravation of thyroid dysfunction occurred during administration of IFN in 1 patient and 4 weeks after the end of IFN therapy in the remaining 3 patients. The 2 patients who demonstrated hyperthyroidism were euthyroid and negative for thyroid autoantibodies before receiving IFN therapy. The remaining 2 patients who demonstrated hypothyroidism were positive for thyroid autoantibodies before IFN therapy. One of these patients had a slight decrease in thyroid function before IFN therapy. Anti-thyroid stimulating hormone (TSH) receptor antibodies became positive in all 4 patients. Since there may have been a causal relationship between IFN therapy and the onset or aggravation of thyroid dysfunction, IFN therapy should be administered with caution.

Adult↗
PubMed1995

Effect of dietary soybean phospholipid and fats differing in the degree of unsaturation on fatty acid synthesis and oxidation in rat liver.

The activities of enzymes in fatty acid oxidation and synthesis in the liver of rats fed soybean phospholipids and soybean oil corresponding to the dietary levels of 3% fatty acid added to the diets containing a saturated fat (coconut oil) and a polyunsaturated fat (safflower oil) at the amounts corresponding to 12% fatty acid levels were compared. Soybean phospholipid compared with soybean oil added to both coconut and safflower oil diets significantly reduced the activities of enzymes in fatty acid synthesis (fatty and synthetase, glucose-6-phosphate dehydrogenase and malic enzyme). However, there were no significant differences in the activities of enzymes in fatty acid oxidation (carnitine palmitoyltransferase, acyl-CoA dehydrogenase and acyl-CoA oxidase) between the groups of rats fed soybean phospholipid and soybean oil added to coconut and safflower oil diets except for one occasion. Soybean phospholipid compared with soybean oil added to coconut oil diet significantly decreased the concentrations of triacylglycerol, cholesterol and phospholipid in the serum and of triacylglycerol and cholesterol in the liver. However, the dietary phospholipid added to safflower oil diet failed to alter these values. These results suggested that the alteration in the rate of fatty acid synthesis, but not oxidation, in the liver is responsible for the lipid-lowering effect of dietary soybean phospholipid added to a saturated fat diet.

Animals↗
PubMed1995

Slit ventricle syndrome successfully treated by a lumboperitoneal shunt.

The authors present the case of a 17-year old man with slit ventricle syndrome, presenting as progressive neurological deterioration after head trauma. Serial computed tomography scans revealed slight ventricular enlargement, suggesting shunt malfunction. Communication between the lumbar subarachnoid space and the lateral ventricles was confirmed by computed tomography cisternography. He underwent a lumboperitoneal shunt, resulting in complete resolution of the symptoms. A lumboperitoneal shunt is considered to be a promising option for the treatment of slit ventricle syndrome.

Adolescent↗
PubMed1995

IgE-mediated allergy to spider mite, Panonychus citri in occupationally exposed individuals.

This paper is the first report on allergy caused by a spider mite, Panonychus citri. Some of fruitgrowers cultivating Citrus junos were manifested immediate allergic symptoms by farming, especially by harvest. By examining C. junos trees, we found the trees cultivated by the fruitgrowers were infested with P. citri. Twelve subjects complaining of immediate allergic symptoms were examined by intradermal test and RAST using allergen extracts prepared from P. citri and Dermatophagoides spp. In intradermal test, ten out of twelve showed a positive response to P. citri and twelve positive to D. farinae. Positive RAST to P. citri were obtained in seven of twelve. Six of them also had positive RAST to D. farinae and D. pteronyssinus. In ELISA inhibition using a serum from Case 4, the inhibition with P. citri extract reached to 92% at the highest concentration used but at the same concentration D. farinae and D. pteronyssinus extracts did not inhibit the binding of specific IgE antibodies to allergen of P. citri. In Case 7, the extracts of P. citri, D. farinae and D. pteronyssinus inhibited at the same concentration 94%, 81%, and 87%, respectively. These results lead to the following conclusions: Seven subjects positive to P. citri in intradermal test and RAST are sensitized to P. citri. P. citri has a specific allergenic determinant in addition to a common determinant with Dermatophagoides spp.

Adult↗
PubMed1995

Telomerase activity in preneoplastic and neoplastic gastric and colorectal lesions.

Recent evidence indicates that telomerase activity may be necessary for cell immortality, which is required for the sustained and indefinite growth of most malignant cells. We analyzed telomerase activity in gastric and colorectal cancers and in gastric and colorectal precancerous lesions to determine whether malignant progression depends on the activation of telomerase and at what stage of carcinogenesis cells have detectable telomerase activity. Telomerase activity was measured by the telomeric repeat amplification protocol assay and was detected in 17 (85%) of 20 primary gastric carcinoma tissues and in 19 (95%) of 20 primary colorectal carcinomas, regardless of tumor staging and histological types. All nodal metastases, peritoneal metastases, and a recurrent gastric cancer tumor were positive. All cell lines established from gastric and colorectal cancers contained telomerase activity. In precancerous lesions, 10 (100%) of 10 colorectal tubular adenomas were telomerase positive, in addition to 3 (23%) of 13 gastric intestinal metaplasias and 1 (50%) of 2 gastric adenomas, whereas the corresponding gastric normal mucosas as well as colorectal mucosas were negative. These results indicate overall that reactivation of telomerase may occur at an early stage of carcinogenesis and may correlate well with malignant progression of gastric cancer. Telomerase activity thus may serve as a powerful additional tool for cancer diagnosis.

Adenocarcinoma↗
PubMed1994

Preparation of a subtractive cDNA library enriched in cDNAs which expressed at a high level in cultured senescent human fibroblasts.

Subtracted cDNA library was prepared by subtracting [cDNA from young growing SV40-transformed human fibroblasts] from [cDNA from growing SV40-transformed fibroblasts in extended lifespan]. Isolated cDNA clones which expressed at high level in life-extended transformed cells also expressed at high level in normal senescent fibroblasts but did at low level in growing and growth-arrested young cells. Neither fibronectin nor procollagen cDNA was isolated. This cDNA library is useful for isolation of senescent-specific cDNA species which express at high level in normal senescent cells but at low level in growing and growth-arrested young cells, avoiding growth-arrest-specific cDNAs.

Animals↗
PubMed1994

Id-related genes encoding helix-loop-helix proteins are required for G1 progression and are repressed in senescent human fibroblasts.

Three complete cDNA clones encoding Id-related helix-loop-helix (HLH) proteins lacking a basic region were isolated from a pcD2 cDNA expression library prepared from TIG-3 human diploid fibroblasts (HDF). Of these cDNAs (Id-1H, Id-1H', and Id-2H), two (Id-1H and Id-1H') appeared to be derived by alternative RNA splicing. Id-1H and Id-2H seem to be human homologues of mouse Id-1 and Id-2, respectively, and have potential to encode 154 and 135 amino acid proteins. The Id-1H and Id-2H mRNAs were barely detectable in quiescent early passage HDF; serum coordinately induced both mRNAs, with two peaks of expression, in early and late in G1. Antisense oligomers complementary to Id-1H and Id-2H mRNA prevented early passage HDF from entering the S phase of the cell cycle. The treatment of serum-stimulated early passage cells with the antisense Id-1H oligomer completely abolished Id-1H. In senescent cells, serum barely induced the Id-1H and Id-2H mRNAs, although the levels of c-myc expression induced were similar in early passage and senescent cells. The expression levels of these Id genes vary among immortal human cell lines. Both genes were overexpressed in VA4 SV40-transformed lung fibroblasts and EJ-1 bladder carcinoma cells, while these genes were expressed at a very low level in SVts8 cells derived from SV40 tsA-transformed TIG-3 cells. SVts8 cells may acquire some function redundant to Id proteins. HT1080 fibrosarcoma cells expressed the Id-1H gene but not the Id-2H gene, suggesting these Id genes may subserve redundant functions.

Alternative Splicing↗
PubMed1994

Isolation of a mammalian cell cycle ts mutant, tsJT663, defective in preparation for passing restriction point.

A cell cycle ts mutant, tsJT663, isolated from Fischer rat cell line 3Y1, was characterized. The execution point of tsJT663 was approximately 2 h before S phase, starting either from a G0 (quiescent) state or from the previous cell cycle. Progression of the cell cycle other than from G0/G1 to S phase was temperature insensitive. The restriction (R) point was also estimated as about 2 h before S phase. When tsJT663 cells at log phase were transferred to 40 degrees C, the cell number increased and then decreased within 2 days and thereafter the cells were growth arrested stably for more than 4 weeks. When the serum-stimulated cells were cultured at 34 degrees C for 6 h at 40 degrees C for various period of time and then at 34 degrees C up to the end of the experiments at 30 h, the frequency of cells entering S phase declined depending upon the duration of culture at 40 degrees C. Assuming that the decline of the frequency of tsJT663 cells capable of entering S phase corresponded to the decline of a putative material required for cells to pass the R point toward S phase, the half-life of this material at 40 degrees C was 1 h. These results are consistent with a tentative conclusion that tsJT663 is a cell cycle ts mutant which does not prepare at nonpermissive temperature for passing the restriction point toward S phase.

Animals↗
PubMed1994

Studies on the antigenicity and nucleotide sequence of the rabies virus Nishigahara strain, a current seed strain used for dog vaccine production in Japan.

The Nishigahara strain of rabies virus, a current seed strain used for animal vaccine production in Japan, is believed to derived from the original Pasteur strain obtained from Paris in or before 1915. In Japan, the virus was serially passaged through several kinds of animals and cell cultures. Reactions with anti-nucleocapsid protein monoclonal antibodies (MAb-N) indicated the Nishigahara strain had maintained the antigenic profile of the Pasteur virus. Reactions with monoclonal antibodies to the glycoprotein (MAb-G) revealed differences between the Nishigahara strain and the Pasteur strain; however, the Nishigahara strain maintained a closer resemblance to the Pasteur virus than to other Pasteur-related viruses or to rabies strains unrelated to the Pasteur strain. Comparative amino acid sequence analysis of cloned cDNA encoding the G gene confirmed the antigenic differences among these strains and the resemblance of the Nishigahara strain to the original Pasteur strain. Comparative nucleotide sequence analysis of the noncoding pseudogene region (Tordo et al., Proc Natl Acad Sci USA 83, 3914-3918, 1986) revealed different relationships. Unlike the Pasteur strain, which encodes a transcription-terminating signal at the end of the G gene (marking the beginning of the pseudogene), a long G-L intergenic sequence in the Nishigahara strain was connected to the 3' end of the cDNA, and the transcription-terminating signal was present only at the end of, but not before, the pseudogene. These results are not inconsistent with the documented origin of the Nishigahara strain, but the genome structure around the pseudogene region suggests divergence from the Pasteur strain and a closer resemblance to other strains of rabies virus.

Amino Acid Sequence↗
PubMed1994

Dietary modifications of the biliary bile acid glycine:taurine ratio and activity of hepatic bile acid-CoA:amino acid N-acyltransferase (EC 2.3.1) in the rat.

Effects of dietary manipulations on the biliary bile acid glycine:taurine (G:T) ratio and the activity of hepatic bile acid-CoA:amino acid N-acyltransferase (EC 2.3.1) in the post-mitochondrial fraction of liver homogenates were examined in the rat. The G:T ratio in rats fed on the diet containing 100 g pectin/kg (2.18) was markedly higher than that in the animals fed on the diet containing 100 g cellulose/kg (0.09). The diets containing either 10 g cholesterol/kg or 5 g sodium cholate/kg, especially the latter, also increased the G:T ratio (0.77 and 2.33 respectively) compared with a control diet free of these steroids (0.34). When the saturating concentrations of taurine (20 mM) and glycine (100 mM) were the substrates, dietary pectin relative to cellulose significantly increased the activity of both taurine- and glycine-dependent bile acid-CoA:amino acid N-acyltransferase, but neither dietary bile acid nor cholesterol influenced it. In spite of the marked difference in the G:T ratio among the rats given various types of experimental diet, the bile acid-CoA:amino acid N-acyltransferase reaction produced taurine-but little glycone-conjugated bile acid when both taurine and glycine coexisted at physiological concentration ranges in the assay media. Dietary manipulations modified the hepatic taurine concentrations and the changes were inversely correlated with those in the G:T ratio. However, hepatic concentration of taurine (1.67-4.82 mumol/g) in rats given various types of experimental diet was comparable with or even higher than the reported Michaelis constant (Km) value of N-acyltransferase for this compound (0.8-2.5 mM).(ABSTRACT TRUNCATED AT 250 WORDS)

Acyltransferases↗
PubMed1994

Reserpine-induced cell transformation without detectable genetic effects in Syrian hamster embryo cells in culture.

Reserpine, a naturally occurring rauwolfia alkaloid, used mainly as an antihypertensive drug, was examined for its ability to induce cell transformation and genetic effects in Syrian hamster embryo (SHE) cells in culture. Treatment of SHE cells with 2 micrograms/ml of reserpine had no effect on cell growth, while 4 micrograms/ml of reserpine reduced the growth rate slightly and 8 micrograms/ml resulted in a significant inhibition of cell growth. Reserpine at doses of 4-8 micrograms/ml for 48 h induced a dose-related increase in morphological transformation of the cells. Reserpine-transformed colonies were morphologically indistinguishable from colonies transformed with benzo[a]pyrene (B[a]P) or other chemical carcinogens. Over the dose range that resulted in cell transformation, treatment of SHE cells with reserpine failed to induce any detectable gene mutations at two genetic loci, chromosomal abnormalities including structural and numerical changes, or DNA adduct formation. These findings indicate that reserpine may have carcinogenic potential by unknown mechanisms that do not include direct induction of gene and/or chromosome mutations.

Aneuploidy↗
PubMed1994

A computer-aided walking rehabilitation robot.

Even with recent techniques, a significant number of patients with multiple injuries cannot be mobilized at an early stage despite the fixation of all fractures. Conventional mobilization aids are not able to provide the prescribed weight bearing needed in fractures, especially those involving both the lower limbs. Robotics is a current technology aimed at improving the quality of medical care. To this end, Takatoshi Ide developed the mobility rehabilitation robot, the REHABOT. This apparatus facilitates rehabilitation by providing secure postural support and prescribed weight bearing during ambulation. The REHABOT has been used for early mobilization and gait training of severely disabled patients at different hospitals in Japan during the last 6 years. In most of the cases, this training has resulted in earlier improvement of ambulatory capability. In this paper we report the use of this device for early ambulation in two patients with multiple fractures involving the extremities and the spine. Early mobilization was achieved by initially reducing the weight bearing to 30% of body weight followed by a gradual increase governed by patient tolerance. The average length of training for these two patients was 18 days. The average total distance was 5.5 km and total walking duration was 4.5 h. After the completion of the training both patients were able to walk independently.

Adult↗
PubMed1994

Depressions by dietary phospholipids of soybean and egg yolk origins of hepatic triacylglycerol and fatty acid synthesis in fasted-refed rats.

Effects of various phospholipid preparations from soybean and egg yolk origins on various indices for lipid biosynthesis in the liver were compared in fasted-refed rats. Phospholipid preparations employed were soybean phospholipid mainly consisting of phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol and phosphatidic acid (soybean PL), egg phospholipid mainly consisting of phosphatidylcholine and phosphatidylethanolamine (egg PL) and purified phosphatidylcholines from soybean (soybean PC) and egg yolk (egg PC) origins. The diet containing 3% fatty acids as soybean and egg PLs compared to the those containing the same amount of fatty acids as the fat blend simulating fatty acid composition of soybean PL and no fatty acids profoundly decreased hepatic concentration of triacylglycerol and liver microsomal concentration of diacylglycerol. Soybean and egg PCs compared to the fat blend also decreased the concentrations of these lipid components in the liver but with the much less extents. Soybean and egg PLs compared to the fat blend also profoundly decreased the activities of enzymes in fatty acid synthesis and of microsomal glycerol 3-phosphate acyltransferase in the liver. These phospholipid preparations compared to the fat blend also significantly decreased the activity of microsomal diacylglycerol acyltransferase when it was measured with endogenous microsomal diacylglycerol substrate. The purified PCs from soybean and egg yolk origins compared to the fat blend also significantly decreased some of these parameters in lipid biosynthesis in the liver but with the much less extents.(ABSTRACT TRUNCATED AT 250 WORDS)

Acyltransferases↗
PubMed1994

tsJT16, a cell cycle ts mutant of rat fibroblast defective in early G0/G1 transition, fails to induce G1-cyclin and cdk2 genes after serum stimulation at the nonpermissive temperature.

tsJT16 is a cell-cycle temperature-sensitive (ts) mutant derived from rat fibroblasts whose functional defect appears soon after the growth stimulation from G0 phase. In addition to c-fos, c-myc and ornithine decarboxylase gene, 7 primarily inducible genes, c-jun, KC, JE, 2F1, 2A9, egr-1, and egr-2, were further shown to be expressed after serum stimulation at both permissive and nonpermissive temperatures. However, expression of secondarily inducible genes, cyclin D1 and D3 and cdk2, was ts and was cycloheximide sensitive. Expression of cyclin C was not inhibited by cycloheximide but it was ts. Failure in expression of G1 cyclins and Cdk2 is suggested to be a causal event for inability of growth induction of tsJT16 at the nonpermissive temperature.

Animals↗