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Biomedical subjects

T Ichikawa

Publications and source records attributed to T Ichikawa.

At least 343 records · Page 19Linked to original sources
PubMed1994

Effect of beta-carotene on spontaneous and X-ray-induced chromosomal damage in bone marrow cells of mice.

The effect of beta-carotene on spontaneous and X-ray-induced chromosomal damage in bone marrow cells of mice was studied. As a source of beta-carotene, dried Dunaliella bardawil (containing 6% beta-carotene) or oil suspension of Dunaliella beta-carotene was used. In Experiment 1, mice were given a basal diet, a 0.5% Dunaliella diet, or a 4% Dunaliella diet for four weeks. In Experiment 2, mice were given an oil suspension of Dunaliella beta-carotene (300 mg/kg body wt) by gavage for seven days while being fed a fat-rich diet. After beta-carotene treatment for the indicated time, spontaneous and X-ray (0.3 Gy, whole-body)-induced chromosomal damage in bone marrow cells was evaluated in terms of the percentages of micronucleated reticulocytes in their peripheral blood. The beta-carotene treatment slightly lowered the spontaneous and X-ray-induced chromosomal damage in bone marrow cells. Despite the higher doses of beta-carotene, the concentrations of beta-carotene in bone marrow, liver, and serum were much lower than those of vitamin E. In addition, the beta-carotene treatment markedly lowered the concentration of vitamin E in the tissues.

Animals↗
PubMed1994

Beta-carotene prevents x-ray induction of micronuclei in human lymphocytes.

The effects of beta-carotene and ascorbic acid on spontaneous and x-ray-induced appearance of micronuclei (MNs) in human lymphocytes were studied. For 12 d, three groups of healthy volunteers were given beta-carotene-deficient meals containing 100 mg ascorbic acid. There was no supplementation in the first 6 d but, in the last 6 d, the respective groups were given beta-carotene (30 mg), ascorbic acid (300 mg), or placebo. Blood samples were drawn on days 7 and 13 before breakfast, exposed either to x-ray irradiation or left unexposed and were cultured. Lymphocytes containing MNs were then counted. On day 7 the three groups showed comparable MN frequencies. On day 13 lymphocytes containing x-ray-induced MNs became less frequent in the beta-carotene but not the ascorbic acid group. Both before and after the supplementation, the MN frequency of irradiated lymphocytes showed a significant inverse correlation with plasma beta-carotene. These results strongly suggest that beta-carotene protects human lymphocytes from x-ray-induced genetic damage.

Adult↗
PubMed1994

Viscous indigestible polysaccharides reduce accumulation of pentachlorobenzene in rats.

To investigate an effect of indigestible polysaccharides (cellulose as control, sodium alginate, guar gum or lambda-carrageenan) on the accumulation of pentachlorobenzene, male Sprague Dawley rats were fed experimental diets containing 5 g/100 g of these polysaccharides for 2 wk. They were then given orally 80 mumol (20 mg) of pentachlorobenzene along with their respective diets and the residual pentachlorobenzene was determined after 7 d. The ingestion of the viscous indigestible polysaccharides resulted in significantly lower accumulation of pentachlorobenzene in adipose tissue, liver and kidney than that found in rats fed a cellulose diet. Soon (5 h) after pentachlorobenzene administration, its concentration in the blood of rats fed sodium alginate and guar gum was higher than that of rats fed cellulose, but lower in the groups fed all three viscous polysaccharides after d 3. These results indicate that pentachlorobenzene excretion was increased by the ingestion of viscous indigestible polysaccharides. Lower relative weight of adipose tissue, a storage tissue for pentachlorobenzene, was found in the rats fed sodium alginate and guar gum. The lower adipose tissue mass was likely the main contributor to the enhancement of pentachlorobenzene excretion.

Administration, Oral↗
PubMed1994

Cloning of cDNAs for genes that are specifically or preferentially expressed during the development of tobacco genetic tumors.

To identify genes involved in the formation of genetic tumors in interspecific hybrids (F1) between Nicotiana glauca and N. langsdorffii, genetic tumor-related cDNA probes were obtained by a subtractive hybridization procedure and used to screen libraries of genetic tumor cDNAs. As a result, 17 distinct cDNA clones were isolated for genes that are specifically or preferentially expressed in genetic tumor tissues but are not expressed at all or are barely expressed in normal F1 plants. Among the isolated clones were genes that encoded so-called stress proteins, such as glucan endo-1,3-beta-glucosidase, osmotin, pathogenesis-related proteins and proteinase inhibitor I. Transcripts corresponding to two of the isolated cDNA clones accumulated to a significant extent only in genetic tumor tissues and were not present in callus tissues from parental plants or in the stems and leaves from normal F1 plants. Analysis of genomic DNA revealed that four of these clones hybridized only to genomic sequences from N. langsdorffii and one hybridized only to a genomic sequence from N. glauca. Eight apparently novel clones were further analyzed to determine the kinetics of accumulation of the corresponding mRNAs during development of genetic tumors. The patterns of accumulation of the mRNAs after induction of tumors by cutting of F1 stems could be divided into three groups, an indication that at least three distinct regulatory mechanisms are operative at the transcriptional level to control the expression of these tumor-related genes during the formation of genetic tumors.

Cloning, Molecular↗
PubMed1994

Adrenal adenomas: characteristic hyperintense rim sign on fat-saturated spin-echo MR images.

PURPOSE: To determine whether adrenal adenomas can be differentiated from metastases on fat-saturated magnetic resonance (MR) images. MATERIALS AND METHODS: Twenty-eight adrenal adenomas and 20 metastatic lesions were imaged at 1.5 T by means of fat-saturated T1- and T2-weighted and gadolinium-enhanced T1-weighted sequences. The authors evaluated visually whether structures of high signal intensity (hyperintense rim sign) could be observed in the outer margin of the adrenal masses. RESULTS: Twenty-six of 28 adrenal adenomas revealed the hyperintense rim sign on at least one kind of fat-saturated image, compared with only one of 20 metastases. The sensitivity of the hyperintense rim sign as suggestive of adrenal adenoma was 92%, specificity was 95%, and overall accuracy was 94%. CONCLUSION: The hyperintense rim sign is characteristic of adrenal adenomas. Thus, adrenal adenomas can be differentiated from metastases by means of this new imaging sign on fat-saturated MR images.

Adrenal Cortex Neoplasms↗
PubMed1994

MOTION-SENSITIVE CELLS: PUTATIVE LARVAL NEURONES INCORPORATED INTO THE OPTIC LOBE OF THE ADULT SWALLOWTAIL BUTTERFLY

Intracellular recordings were made from neurones with large somata situated at the anteromedial edge of the medulla of the swallowtail butterfly Papilio xuthus; the neurones were then filled with Lucifer Yellow. These cells are putative larval visual interneurones incorporated into the adult optic lobe of the butterfly. There are four classes of motion-sensitive neurones. Two have a dendritic arborization in the dorsal half of the medulla and project an axon to the medial protocerebrum or the contralateral medulla. They respond to vertical downward motion with a strong burst of action potentials and their background activities are inhibited by motion in the opposite direction. Variations in position of the dendritic fields suggest that each group of neurones forms a coherent set of cells detecting vertical motion in the dorsal half of the visual field of the eye. The third class of neurones connects the lobula plate to the midbrain and is preferentially sensitive to vertical upward motion. The fourth class of neurones has a dendritic arborization in the lobula. These neurones are tonically excited by a moving grating irrespective of the stimulus orientation and movement direction. The presence of motion-sensitive medulla neurones suggests that the detection of local motion is completed in the distal medulla.

Journal Article↗
PubMed1994

Aggregation of DNA enhanced by the protoberberine alkaloids, coralyne and berberine.

The aggregation of DNA caused by coralyne was studied by spectroscopic, viscosity and electric birefringence measurements. Aggregation was markedly enhanced over a narrow range of coralyne to DNA phosphate ratio and then followed by precipitation. The electric birefringence measurements indicated that the ratio at the maximal aggregation varied depending on the concentration of coralyne, finally reaching 1:1 at higher concentrations. The particles (type I) for such enhanced aggregation were estimated to be prolate ellipsoids 1700-4000 A in length with a diameter of 1400-4000 A. At higher coralyne concentrations, another particle (type II) was formed which was a thick rod-like particle 1700-4000 A in length with a diameter of 120-210 A. These dimensions indicate that type I and II particles consist respectively of several tens of thousands and some hundreds of molecules of DNA. On the other hand, berberine did not produce such a marked aggregation of DNA, and the result was a thick rod-like particle 1700-4000 A in length with a diameter of 300-1000 A. The enhancement by coralyne and berberine is discussed in terms of intermolecular interactions.

Animals↗
PubMed1994

Effects of Z-300, a new histamine H2-receptor antagonist, on mucin biosynthesis in rat gastric mucosa.

We examined the effects of Z-300 (N-[3-[3- (piperidinomethyl)phenoxy]propyl]-2-(2-hydroxy-ethyl-1-thio)acetam ido.2- (4-hydroxy benzoyl)benzoate), a newly-synthesized selective histamine H2-receptor antagonist, on mucin in rat gastric mucosa. Deep corpus mucin content increased significantly to 127% of the control after the administration of 30 mg/kg of Z-300, whereas that in the antral mucosa did not increase. The addition of Z-300 significantly increased [3H]-labeled mucin in the corpus region. In the antrum, biosynthetic activity showed no significant change by 10(-8)-10(-5) M of Z-300. These results suggest that Z-300 not only inhibits acid secretion but may also promote gastric mucus metabolism in the corpus region.

Acetamides↗
PubMed1994

Effect of family group psychotherapy on alcoholic families.

We examined the effect of family group psychotherapy on 14 alcoholic families. Family group psychotherapy helped alcoholic families be aware of their anxiety and conflict and enabled them to share their feelings with a group. Alexithymia for a cognitive-affective disturbance significantly decreased after group psychotherapy. Moreover, participation in family group psychotherapy over six months increased family cohesion and allowed anxiety and conflict to be more easily expressed within the family.

Adult↗
PubMed1994

[Measurement of serum prostatic acid phosphatase (PAP) by Delfia PAP Kit using europium and clinical evaluation in patients with prostate cancer].

Fundamental and clinical studies of serum prostatic acid phosphatase (PAP) detected by a Delfia PAP kit were performed. The system is a time-resolved fluoroimmunoassay using europium as a tracer. The lower limit of detection was 0.2 ng/ml. Sera from 54 patients with prostate cancer, 20 with benign prostatic hypertrophy, 20 with urological malignancies other than prostate cancer and 140 adult males over 46 years old were determined. From the mean + 2 S.D. of serum PAP values obtained on the adult males, 1.5 ng/ml was considered as the upper normal level of adult males. By calculating the efficiency and ROC curve using the PAP values of prostate cancer and benign prostatic cancer, 2.5 ng/ml was decided as a cut-off value of this kit. The positive rates of adult males, prostate cancer, benign prostatic cancer and urological malignancies other than prostate cancer were 0.7%, 65%, 20% and 10%, respectively. The sensitivity of stage A2, B2, C and D1 + D2 was, 0%, 0%, 64% and 83%, respectively. The efficiency of the Delfia PAP kit was 52% and that of the Markit M PA kit was 71%. The correlation between the values assayed with the Delfia PAP kit and the Dinabot PAP kit was very high; the value obtained with the Delfia PAP kit was about 80% of that obtained with the Dinabot PAP kit.

Acid Phosphatase↗
PubMed1994

Effect of vitamin E on 4-nitroquinoline 1-oxide-induced lung tumorigenesis in mice.

Oxidative stress may play a partial role in chemically induced tumorigenesis in mice. Herein, we investigated the preventive effect of vitamin E on 4-nitroquinoline 1-oxide (4NQO)-induced oxidative damage on pulmonary nuclei and lung tumorigenesis in mice. At 4 weeks after 4NQO injection, the levels of nuclear thiobarbituric acid substances (TBARS) and DNA single strand breaks (DNA-SSB) in the lungs of mice treated with 4NQO were significantly higher than those in the control mice. The 4NQO-induced oxidative stress on the nuclei and DNA-SSB were significantly inhibited by vitamin E treatment. The nuclear alpha-tocopherol level in the 4NQO-treated group was significantly lower than that in the control, but the plasma alpha-tocopherol level in the former was slightly lower than that in the latter. Vitamin E feeding compensated the decrease of the level in the nuclei and plasma. The feeding on excessive vitamin E for 23 weeks after 4NQO injection could partly reduce the lung tumor incidence as well as lung tumor multiplicity in mice. These findings suggest that vitamin E could partly suppress 4NQO-induced lung tumorigenesis in mice, probably through the inhibition of 4NQO-induced oxidative damage on the nuclei.

4-Nitroquinoline-1-oxide↗
PubMed1994

[Induction and prevention of kidney injury induced by GSH depletion and vitamin E deficiency in rats].

Four-week-old Wistar male rats were fed a vitamin E (VE)-deficient diet for 8 weeks, followed by intraperitoneal injection of DL-buthionine- [S, R] -sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthetase, at the dose of 1 mmol/kg body weight. As we reported previously, GSH depletion by administration of BSO induced acute tubular necrosis in the kidney of VE-deficient rats and was accompanied by decrease of renal TBA value and marked increase of renal lipofuscin content. In this study, we examined the effect of administration of AsA or Trolox C on these kidney injuries. AsA or Trolox C treatment increased renal GSH content and inhibited the increase of renal lipofuscin production. The increase of BUN and creatinine levels and LDH activity in the sera of rats administered BSO were inhibited by AsA or Trolox C treatment. AsA treatment completely protected the necrosis of epithelia of proximal renal tubules. These results suggest that GSH has an important role in preventing lipofuscin production through the reaction of lipid peroxides with amino acids. AsA spares GSH indicating that these compounds have similar antioxidant actions and that AsA can serve as an essential antioxidant in the presence of severe GSH deficiency.

Animals↗
PubMed1994

[A study of low density lipoprotein in a patient with hyper-high density lipoprotein cholesterolemia with normal cholesterolester transfer protein].

We examined a patient with hyper-cholesterolemia with a high level of HDL2 and LDL-cholesterol in serum. The metabolism of lipoproteins in this case was different from that in well-known hyper-high density lipoproteinemia or hyper-low density lipoproteinemia, because the patient had normal levels of cholesterolester transfer protein, lipoprotein lipase and hepatic triglyceride lipase activity. This study describes the characterization of LDL obtained from the patient's serum. LDL from the patient was separated by ultracentrifuge, and analyzed by gradient PAGE. The molecular weight of two LDL from the patient have been estimated to be approximately 1250 and 1450kDa by polyacrylamide gel electrophoresis, and were larger than those of normal individuals and patients with typical hypercholesterolemia (approximately 1150kDa in molecular weight). The LDL from the patient was separated into three fractions by HPLC, and their lipid composition was not significantly different from that of normal LDL. The high level and large size of LDL from the patient may be caused by a reduction in the transfer of cholesterol from LDL to HDL2, or an equilibrium of cholesterol with the increased HDL2.

Aged↗
PubMed1994

Effect of vitamin E on chromosomal damage in bone marrow cells of mice having received low dose of X-ray irradiation.

When mice had received various doses (0, 0.1, 0.2, 0.4 and 0.8 Gy) of X-ray to their whole bodies, the increased % of reticulocytes with micronucleus (MNs) in peripheral blood, an indicator of chromosomal damage in bone marrow cells, was the highest at 44 hr after the irradiation. At the time, the dose-dependent increase of the % was clearly observed. Using this method, the protective effect of vitamin E on X-ray-induced chromosomal damage was examined. Mice were given various doses (0, 75, 300 mg/kg body weight) of vitamin E by intragastric gavage for 4 days, or fed either a basal vitamin E diet (3 mg % of vitamin E) or a high vitamin E diet (100 mg % of vitamin E) for 5 weeks. Then, the mice were given whole body X-ray irradiation at the dose of 0.3 or 0.4 Gy. Vitamin E concentration in bone marrow cells was significantly elevated by the vitamin E treatment, but was not decreased after irradiation. The vitamin E treatment was unable to inhibit the % of reticulocytes with MNs induced by the irradiation. These results indicate that vitamin E in the bone marrow could not significantly prevent chromosomal damage in bone marrow cells against a low dose of X-ray irradiation.

Animals↗
PubMed1994

Primary malignant lymphoma of the brain: demonstration of the p53 gene mutations by PCR-SSCP analysis and immunohistochemistry.

Using PCR-SSCP and immunohistochemical analyses, mutations of the p53 tumor suppressor gene were examined in 5 cases of primary malignant lymphoma of the brain (diffuse large cell type). By PCR-SSCP and nucleotide analyses, p53 gene mutations were seen in 2 of the 5 cases. The mutation in one case was a missense G: C-T:A transversion at codon 176 (TGC-TTC; Cys-Phe) which was located in the highly conserved domains and adjoined a previously proposed hot spot codon (codon 175) in various tumors. p53 immunoreactivity was also shown in this case. The mutation in another case was a nonsense G:C-A:T transition at codon 52 (TGG-TGA; Trp-stop codon) leading to a truncated p53 peptide. Thus, these mutations may have actually given rise to serious structural and functional alterations of the p53 protein. These findings suggested that the p53 gene mutation was related with oncogenesis in the primary malignant lymphoma of the brain.

Adult↗
PubMed1994

Effect on gastric mucus of the proton pump inhibitor leminoprazole and its cytoprotective action against ethanol-induced gastric injury in rats.

The effect of leminoprazole ((+-)-2-[[2-(isobutyl-methylamino)benzyl]sulfinyl]-1H-benzimidazol e, NC-1300-O-3, CAS 104340-86-5), a new compound being developed as an inhibitor of the gastric mucosal proton pump (H+,K(+)-ATPase), on gastric mucus secretion was studied by a biochemical method measuring the gastric mucin content in rats. Oral administration of leminoprazole (30 mg/kg) strongly inhibited the hemorrhagic lesions induced by 60% ethanol containing 0.15 mol/l HCl (acid-ethanol) administered 1 h later. Leminoprazole significantly inhibited the acid-ethanol-induced reduction of the mucin content in the surface mucosa including the mucus gel layer, but no significant effect could be obtained on the reduction of mucin present in the deep layer of the corpus and antral mucosa. Leminoprazole given to rats not treated with acid ethanol accelerated the secretion of deep mucosal mucus and increased significantly the content of soluble mucus which was recovered from the gastric luminal contents to about 200% of control, but failed to produce any significant change in the mucus content present in the surface mucosal and the mucus gel layers. The effect of leminoprazole on gastric mucus secretion might contribute to healing the peptic ulcer diseases and may be involved in the cytoprotective mechanism of this drug.

2-Pyridinylmethylsulfinylbenzimidazoles↗