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Biomedical subjects

S Tani

Publications and source records attributed to S Tani.

At least 19 recordsLinked to original sources
PubMed2006

Background values for evaluation of heavy metal contamination in sediments.

The contamination of sediments can be evaluated from comparison of the current concentration with the estimated background value. Although it is known that grain size affects background concentrations, there have been difficulties in evaluating this effect. The specific surface area of sediments, which can be calculated from the grain size distribution, is introduced as a property index for correlation of background values. The results show that for sandy-to-sandy silt sediments, the background values of metals are expressed in terms of fines content, which can be correlated with the corresponding specific surface area. However, for silty clay or clayey silt sediments, which would have a high metal retention capacity, the level of the background may be constrained by the relatively low concentrations of metals in seawater. Finally, background levels of Zn, Cu and Pb are presented.

Adsorption↗
PubMed2002

Problems in health management of professional boxers in Japan.

OBJECTIVE: To investigate whether the incidence of boxing accidents is higher in Japan than in other countries. METHOD: A nationwide survey of boxers was conducted. RESULTS: A total of 632 boxers responded. Most Japanese boxers were relatively mature when they started boxing (mean starting age of 19.2 years). A high percentage of boxers was found three weight divisions higher than previously reported. Many boxers stated that losing weight was not a big problem. It was found that a punch that turns the head can cause serious physical damage, and it was clarified that only a simple punch, rather than accumulated damage from multiple punches, can cause cerebral concussion. Severe shock causing retrograde amnesia is very rare after a fight and disappears relatively quickly. Many additional symptoms are related to damage to the hearing organs, such as hearing difficulties, tinnitus, and vertigo, but these symptoms also resolve quickly. Many boxers experience memory disturbance, not just after a fight but in daily life. CONCLUSION: The approach to boxing has become more oriented towards the method of practice and scientific training, rather than psychological factors, which used to be emphasised.

Boxing↗
PubMed2002

Postnatal changes in ghrelin mRNA expression and in ghrelin-producing cells in the rat stomach.

Ghrelin was recently isolated from the rat stomach as an endogenous ligand for the GH secretagogue receptor. Although it is well known that a large amount of ghrelin is produced in the gastrointestinal tract, developmental changes in ghrelin mRNA expression and differentiation of ghrelin-immunopositive (ghrelin-ip) and mRNA-expressing (ghrelin-ex) cells in the stomach have not been elucidated. In this study, we therefore investigated the changes in ghrelin mRNA expression levels and in the numbers of ghrelin-ip and -ex cells in the stomachs of 1- to 8-week-old male and female rats by Northern blot analysis, immunohistochemistry and in situ hybridization. Northern blot analysis showed that the level of weak ghrelin mRNA expression was low in the postnatal period but then increased in a dimorphic pattern, i.e. transient stagnation at 4 weeks in the male rats and at 5 weeks in the female rats. The number of ghrelin-ip and ghrelin-ex cells also increased after birth, and more numerous ghrelin cells were found in female rats than in male rats, and this finding was confirmed by Northern blot analysis. Ghrelin-ip and -ex cells first appeared in the glandular base of the fundic gland and then they were found in the glandular base and the glandular neck at 3 weeks of age, suggesting that the distribution of ghrelin cells is extended from the glandular base to the glandular neck during the postneonatal development period. This is the first report on detailed changes in postneonatal ghrelin expression level and in the number of ghrelin cells in the rat stomach. The sexual dimorphism of ghrelin expression and ghrelin cell differentiation suggest that ghrelin plays an important physiological role in the stomach.

Animals↗
PubMed2001

Serum amyloid P component is the Shiga toxin 2-neutralizing factor in human blood.

It has been suggested that some factor present in human plasma binds to Shiga toxin 2 (Stx2) and neutralizes it in vitro (Bitzan, M., Klemt, M., Steffens, R., and Muller-Wiefel, D. E. (1993) Infection 21, 140-145). This factor does not exist in other species (Caprioli, A., Luzzi, I., Seganti, L., Marchetti, M., Karmali, M., Clarke, I., and Boyd, B. (1994) Recent Adv. VTEC Infect. 353-356). Because analysis of this factor is important to understanding the pathology induced by Shiga toxin-producing Escherichia coli, we purified this factor from human plasma and identified it. Purification was carried out by serially subjecting human plasma to Con A-Sepharose, DEAE-Sepharose, hydroxyapatite, and gel-filtration high performance liquid chromatography (HPLC), using Stx2-neutralizing activity as the indicator. The gel-filtration HPLC fraction yielded a single band on SDS-polyacrylamide gel electrophoresis. Twenty N-terminal amino acid residues of this fraction were analyzed and found to correspond perfectly to human serum amyloid P component (HuSAP). Because commercially available HuSAP also showed Stx2 binding and neutralizing activity, we identified this factor as HuSAP.

Amino Acid Sequence↗
PubMed2001

The N- and C-terminal regions of RBP-J interact with the ankyrin repeats of Notch1 RAMIC to activate transcription.

The evolutionarily-conserved DNA-binding protein RBP-J directly interacts with the RAM domain and the ankyrin (ANK) repeats of the Notch intracellular region (RAMIC), and activates transcription of downstream target genes that regulate cell differentiation. In vitro binding assays demonstrate that the truncated N- and C-terminal regions of RBP-J bind to the ANK repeats but not to the RAM domain. Using an OT11 mouse cell line, in which the RBP-J locus is disrupted, we showed that RBP-J constructs mutated in the N- and C-terminal regions were defective in their transcriptional activation induced by either RAMIC or IC (the Notch intracellular region without the RAM domain) although they had normal levels of binding activity to DNA and the RAM domain. The studies using chimeric molecules between RBP-J and its homolog RBP-L showed that the N- and C-terminal regions of RBP-J conferred the IC- as well as RAMIC-induced transactivation potential on RBP-L, which binds to the same DNA sequence as RBP-J but fails to interact with RAMIC. Taken together, these results indicate that the interactions between the N- and C-terminal regions of RBP-J and the ANK repeats of RAMIC are important for transactivation of RBP-J by RAMIC.

Animals↗
PubMed2001

Biological activity of kiwifruit peel extracts.

Various bioactive substances in kiwifruit extracts were fractionated by organic solvent extractions, followed by silica gel and ODS chromatographies. Both cytotoxic activity and multi-drug resistance reversal activity were found in the less polar fractions. Cytotoxic activity was not always parallel the radical intensity. Antibacterial activity was distributed into various fractions and all fractions were inactive against Candida albicans and H. pylori. Only 70% methanol extracts showed anti-human immunodeficiency virus activity, and produced a broad ESR signal under alkaline conditions, in a fashion similar to lignin. These fractions also effectively scavenged O(2)(-) produced by the xanthine-xanthine oxidase reaction, suggesting a bimodal (pro-oxidant and antioxidant) action. These data suggest a medicinal efficacy of kiwifruit peel extracts.

Animals↗
PubMed2001

Characterization of the amyR gene encoding a transcriptional activator for the amylase genes in Aspergillus nidulans.

The Aspergillus nidulans amyR gene and its cDNA were cloned and sequenced. The genomic gene comprised 2,092 bp, interrupted by two short introns, and encoded a cys-6 zinc transcriptional activator (AMYR) of 662 amino acid residues with a calculated molecular mass of 72,862 Da. Disruption of the amyR gene caused defects in the utilization of maltose and starch and abolished expression of the taaG2 gene encoding A. oryzae Taka-amylase A, which is inducibly and abundantly expressed in the wild-type A. nidulans. Expression of the amyR gene was under the control of the carbon catabolite repressor, CREA. The growth defect of the malA1 mutant on maltose was complemented by the amyR gene; and the amyR gene derived from the mutant possessed a single mutation, from A to T, at position 1,483, resulting in a substitution of His478 to Leu. These results indicate that the amyR gene is identical to the genetically defined malA gene. AMYR possessed five domains (Zn and MH1-MH4) homologous to Mal63p, a transcriptional activator for the genes involved in maltose utilization in Saccharomyces cerevisiae. The His478 to Leu substitution lay within the MH3 domain, corresponding to the negative regulatory domain of Mal63p which relieves the inhibitory effect on the activation function in response to maltose.

Amino Acid Sequence↗
PubMed2001

Antimicrobial activity of new coumarin derivatives.

A preliminary exploration of coumarin analogs as novel antimicrobial agents was carried out to determine the basic features of the structure responsible for the observed biological activity. The substituents ester or carboxylic acid on the coumarin ring were needed to have potent inhibitory activity against both Gram-positive and Gram-negative bacteria. The presence of phenolic hydroxyl group and/or carboxylic acid was necessary to possess higher activity against Helicobacter pylori.

Anti-Bacterial Agents↗
PubMed2001

Synthesis and DNA binding properties of alkyl-linked bis(benzimidazole) compounds.

We have synthesized novel alkyl-linked bis(benzimidazole) compounds and studied their DNA binding properties by spectroscopic (absorption, CD, flow dichroism and fluorescence) and viscosity measurements. The results indicate that bis(benzimidazole) compounds interact with DNA both by intercalation and by groove binding.

Alkylation↗
PubMed2001

Solution structures of the DNA complexes with alkyl-linked bis(benzimidazole) compounds studied by NMR spectroscopy.

We have synthesized two novel alkyl-linked bis(benzimidazole) compounds related to pentamidine. The solution structures of 1:1 complexes of these compounds with the self-complementary DNA duplexes, d(CGCGAATTCGCG)2 (A2T2) and d(CGCAAATTTGCG)2 (A3T3) have been studied by one- and two-dimensional 1H NMR spectroscopy. The intermolecular NOE data of the A3T3 complexed with compound 3 indicate that 3 binds in the minor groove of the central 5'-CAAATTTG region of A3T3.

Alkylation↗
PubMed2001

Vascular orientation by intra-arterial dye injection during spinal arteriovenous malformation surgery.

OBJECTIVE: Rich and complicated vascular structures on the spinal cord often interfere with obliteration of a spinal arteriovenous malformation (AVM). Vascular orientation during spinal AVM surgery is essential. The authors recently performed six consecutive spinal AVM surgeries in five patients (two with perimedullary AVMs, and three with dural arteriovenous fistulae) with the aid of intra-arterial injection of dye (indigo carmine). METHODS: Two representative cases are described. A microcatheter was placed preoperatively in the artery of interest. Subsequent to the exposure of the vascular complex, a 1-ml injection of indigo carmine (2 mg/ml) clearly demonstrated the feeding arteries and the draining veins around the AVM or dural arteriovenous fistula. RESULTS: One patient had repeat surgery because of incomplete obliteration of the AVM owing to migration of the catheter. All patients, except one who had temporary postoperative deterioration and persistent neurological deficits, had good surgical outcomes, however. No apparent side effects caused by the dye were reported. CONCLUSION: The assistance system for spinal AVM surgery is easy and safe and can be applied in other surgical institutions.

Angiography↗
PubMed2001

Trifluoromethyl ketone-based inhibitors of apoptosis in cerebellar granule neurons.

A variety of aromatic trifluoromethyl ketone derivatives has been studied as inhibitors of apoptosis in cerebellar granule neurons (CGNs). Among them, alpha-trifluoromethyl diketone (2) and benzyl trifluoromethyl ketone (11) were found to be apoptosis inhibitors which can prevent a neurodegenerative disease. Compounds 2 and 11 showed neuroprotection effect on low K+-induced apoptosis in CGNs. Furthermore, these compounds effectively suppressed DNA fragmentation accompanied with apoptosis. The neuroprotection mode of 2 and 11 was not related to inhibition of caspase-3.

Acetic Anhydrides↗
PubMed2001

Effect of glucocorticoid on expression of rat MUC5AC mRNA in rat gastric mucosa in vivo and in vitro.

The gastric mucus is an important factor in the gastric mucosal protection from acid, pepsin and various reagents (alcohol, aspirin, etc.). MUC5AC is the mucin secreted from surface mucous cells, and belongs to the gel-forming mucin. We examined the regulation of rat MUC5AC (rMUC5AC) mRNA by glucocorticoid in vivo and in vitro, comparing it with that of pepsinogen (Pg) mRNA. By adrenal gland resection, rMUC5AC and Pg mRNA levels and Pg content in rats significantly decreased to 70%, 46% and 42% of those in the sham operated controls, respectively. With the treatment of hydrocortisone (1, 5 and 50 mg/kg), Pg mRNA level and Pg content in adrenalectomized rats was restored. On the other hand, the rMUC5AC mRNA level exceeded the control with 1 or 5 mg/kg injections of hydrocortisone, but drastically decreased to 18% of sham operation levels with it (50 mg/kg). Similar results were obtained in normal rats with the treatment of hydrocortisone (50 mg/kg). Mucus and DNA content of cultured rat gastric epithelial cells were not affected by hydrocortisone, but rMUC5AC mRNA level was significantly decreased in a dose-dependent manner. From the in vivo and in vitro results, at least a physiological concentration of glucocorticoid was necessary in the expression of rMUC5AC mRNA. However, high dose of hydrocortisone directly suppressed the expression of rMUC5AC mRNA. These results suggested that hydrocortisone might directly cause the suppression and indirectly the enhancement of the mucin biosynthesis.

Adrenalectomy↗
PubMed2001

Reduction of acetals with samarium diiodide in acetonitrile in the presence of Lewis acids.

Transformation of acetals into ethers by partial reduction using a samarium diiodide-Lewis acids-acetonitrile system is described. The reaction with aromatic acetals occurred in good yields in the presence of aluminum chloride (2 eq) whereas the corresponding aliphatic, vinylic, and alkynyl derivatives did not afford ethers under the same conditions. Beta-elimination to give an enol ether becomes predominant when aliphatic acetals that possess a hydrogen at the 2-position are treated with iodotrimethylsilane in the presence of SmI2 or SmI3.

Acetals↗
PubMed2001

In vivo and in vitro analyses of the AmyR binding site of the Aspergillus nidulans agdA promoter; requirement of the CGG direct repeat for induction and high affinity binding of AmyR.

The alpha-glucosidase gene (agdA) of Aspergillus nidulans has a single CGGN8CGG type AmyR binding site in its promoter region. The binding site is functional in vivo as a cis-element responsible for induction by starch, and mutational studies indicated that both the CGG triplets are required for high-level induction. A part of AmyR (residues 1-411; AmyR(1-411)), which was produced as a MalE fusion protein in E. coli, bound to the CGGN8CGG site of the agdA promoter. DNA binding profiles to the mutant binding sites that lacked both or either one of the CGG triplets suggested that AmyR(1-411) can bind to a single CGG triplet site with low affinity and that two AmyR molecules cooperatively bind to the CGG direct repeat.

Aspergillus nidulans↗
PubMed2001

[Isolated abducens nerve palsy caused by the compression of the basilar artery: a case report].

Several pathological etiologies are responsible for abducens nerve palsy, but a neuro-vascular compression of the basilar artery has rarely been recognized as one of the causes. We performed magnetic resonance imaging of the brainstem of 71-year-old female patient with left abducens nerve palsy using constructive interference in the steady state (CISS) method, which allowed high-resolution T 2-weighted imaging and detection of the artery and nerves as high and low intensity area respectively. MRI with CISS revealed the compression of the abducens nerve by the basilar artery at the root exit zone. During the first examination her systolic blood pressure was over 180 mmHg, so we prescribed hypotensive agents until it to normalized. Her symptom of abducens nerve palsy improved after a few days. It is conceivable that compression of the basilar artery may have caused isolated abducens nerve palsy as disclosed by MRI with CISS.

Abducens Nerve Diseases↗
PubMed2000

Smoking increases tissue factor expression in atherosclerotic plaques: implications for plaque thrombogenicity.

BACKGROUND: Smoking increases the risk of atherothrombotic events. To determine whether smoking influences plaque thrombogenicity, we examined the effect of cigarette smoking and aspirin use on tissue factor (TF) expression in atherosclerotic plaques. METHODS AND RESULTS: A total of 23 apoE-/- mice were exposed to cigarette smoke with (n=9) or without (n=14) aspirin treatment. Eleven mice who were exposed to filtered room air served as controls. Aortic root plaques of mice exposed to smoke had higher immunoreactivity for TF (14+/-4% versus 6.4+/-3%; P=0.0005), vascular cell adhesion molecule-1 (15+/-4% versus 5+/-2%; P=0.002), and macrophages (16+/-5% versus 6+/-2%; P=0.002) compared with nonsmoking controls. Aspirin treatment attenuated smoking-induced changes in plaque composition. In human plaques obtained by carotid endarterectomy, TF immunoreactivity (8+/-5% versus 2+/-2%; P=0.0002) and activity (P=0. 03) were higher in the plaques from smokers (n=28) than those from nonsmokers (n=28). Aspirin use was associated with reduced TF expression in smokers (9+/-8% versus 3+/-4%; P=0.0017). CONCLUSIONS: Our results suggest increased plaque TF expression and thrombogenicity as a novel mechanism for the increased risk of atherothrombotic events in smokers. Treatment with aspirin may reduce TF expression.

Aged↗