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Biomedical subjects

N Kida

Publications and source records attributed to N Kida.

At least 19 recordsLinked to original sources
PubMed2006

Enhanced optical magnetoelectric effect in a patterned polar ferrimagnet.

A simple method to dramatically enhance the optical magnetoelectric (ME) effect, i.e., nonreciprocal directional birefringence, is proposed and demonstrated for a polar ferrimagnet GaFeO3 as a typical example. We patterned a simple grating with a period of 4 microm on a surface of GaFeO3 crystal and used the diffracted light as a probe. The optical ME modulation signal for the Bragg spot of the order n=1 becomes gigantic in the photon energy 1-4 eV and reaches 1-2% of the bare diffracted light intensity in a magnetic field of 500 Oe. This is amplified by more than 3 orders of magnitude compared to that for the reflection of bulk GaFeO3. Fabricating a photonic crystal will make it possible to lead the way for the practical use of the optical ME effect.

Journal Article↗
PubMed2006

[Off-pump atrial septectomy in a small neonate].

We report a surgical technique for off-pump atrial septectomy using a Rongeur forceps in the case of a newborn infant weighing less than 2,000 grams. The 6-day-old patient suffered from hypoplastic left heart syndrome with a restrictive interatrial communication. A purse-string suture was placed on the right atrium. A hand-made dull-tipped cannula was inserted into the right atrium through the suture to probe the interatrial communication. Monitoring the pressure at the tip of cannula, we could clearly determine when the cannula tip entered the left atrium. Then, a Rongeur forceps was inserted instead of the cannula, and used to bite into the interatrial septum. It was removed slowly together with the resected atrial specimen. In this manner, an atrial septectomy can be performed without cardiopulmonary bypass; this is far safer and easier than other procedures, such as the Blalock-Hanlon technique. This method can be performed in a small neonate as well as an older infant in whom balloon atrial septostomy is difficult.

Cardiac Surgical Procedures↗
PubMed2005

Optical magnetoelectric effect in a submicron patterned magnet.

The optical magnetoelectric effect, which is a nonreciprocal directional dichroic response, has been demonstrated in a submicron patterned magnet by monitoring the diffracted visible or near-infrared light intensity. An artificial magnetic superstructure is composed of chevron shaped ">" islands made of the ferromagnetic permalloy Ni(80)Fe(20) with a pitch of 1 microm on silicon substrate, in which both space inversion and time reversal symmetry are broken simultaneously. On the basis of the light-polarization angle and magnetic field H dependence, and also comparing the results with the those of the submicron square patterns, we show that the optical magnetoelectric effect emerges as the finite change (approximately 10(-3) at room temperature in H of 500 Oe) of the diffracted intensity.

Journal Article↗
PubMed2004

An effective iodide formulation for killing Bacillus and Geobacillus spores over a wide temperature range.

AIMS: To develop a sporicidal reagent which shows potent activity against bacterial spores not only at ambient temperatures but also at low temperatures. METHODS AND RESULTS: Suspension tests on spores of Bacillus and Geobacillus were conducted with the reagent based on a previously reported agent (N. Kida, Y. Mochizuki and F. Taguchi, Microbiology and Immunology 2003; 47: 279-283). The modified reagent (tentatively designated as the KMT reagent) was composed of 50 mmol l(-1) EDTA-2Na, 50 mmol l(-1) ferric chloride hexahydrate (FeCl(3).6H(2)O), 50 mmol l(-1) potassium iodide (KI) and 50% ethanol in 0.85% NaCl solution at pH 0.3. The KMT reagent showed significant sporicidal activity against three species of Bacillus and Geobacillus spores over a wide range of temperature. The KMT reagent had many practical advantages, i.e. activity was much less affected by organic substances than was sodium hypochlorite, it did not generate any harmful gas and it was stable for a long period at ambient temperatures. The mechanism(s) of sporicidal activity of the KMT reagent was considered to be based on active iodine species penetrating the spores with enhanced permeability of the spore cortex by a synergistic effect of acid, ethanol and generated active oxygen. CONCLUSIONS: The data suggest that the KMT reagent shows potent sporicidal activity over a wide range temperatures and possesses many advantages for practical applications. SIGNIFICANCE AND IMPACT OF THE STUDY: The results indicate development of a highly applicable sporicidal reagent against Bacillus and Geobacillus spores.

Anti-Bacterial Agents↗
PubMed2001

Neuromuscular fatigue during maximal concurrent hand grip and elbow flexion or extension.

The objective was to investigate muscle fatigue measuring changes in force output and force tremor and electromyographic activity (EMG) during two sustained maximal isometric contractions for 60s: (1) concurrent hand grip and elbow flexion (HG and EF); or (2) hand grip and elbow extension (HG and EE). Each force tremor amplitude was decomposed into four frequency bands (1-3, 4-10, 11-20, and 21-50Hz). Surface EMGs were recorded from the flexor digitorum superficialis (FDS), extensor digitorum (ED), biceps brachii (BB) and lateral head of triceps brachii (TB). The HG and EF forces for the HG and EF and the HG force for the HG and EE declined rapidly, whereas the EE force remained almost constant near to the initial value for the first 40s and then declined. The decrease in EMG amplitude was observed not for the FDS muscle but for the ED muscle. The HG tremor amplitude for each frequency band showed similar decreasing rate, whereas the decreases in EF and EE tremor amplitudes for the lower band (below 10Hz) were slower than those for the higher band (above 11Hz). The neuromuscular mechanisms underlying muscle fatigue during sustained maximal concurrent contractions of hand grip and elbow flexion or extension are discussed.

Adult↗
PubMed2001

Central and peripheral visual reaction time of soccer players and nonathletes.

Visual Reaction Time (RT) was measured by presenting three different sizes of stimulus to the central and peripheral fields of vision in 6 soccer players and 6 nonathletes. An electromyogram was recorded from the flexor digitorum superficialis muscle of the responding forearm. Peripheral visual RT was longer in comparison to central visual RT due to an increment in Premotor Time. The soccer players showed shorter Premotor Times during central and peripheral visual RT tasks than nonathletes, suggesting that the soccer players are better able to respond quickly to a stimulus presented to peripheral as well as central positions.

Adult↗
PubMed1995

Rapid detection of Vibrio cholerae with a new selective enrichment medium and polymerase chain reaction.

The inhibitory effect of metallic EDTA compounds on growth of Vibrio cholerae and Escherichia coli was studied. Only Fe-EDTA among the compounds tested showed pH-dependent growth inhibition on E. coli at pH 9.0, but no inhibition of V. cholerae at the same pH. By addition of Fe-EDTA as a selective inhibitor, a novel enrichment broth (tentatively designated as VCF broth) for the selective isolation and cultivation of V. cholerae from other Gram-negative bacilli has been developed, and the selective enrichment capacity of VCF broth for V. cholerae and selective inhibiting activity against E. coli were significantly higher than those of alkaline peptone water. A simple procedure for rapid detection of V. cholerae by selective enrichment for 6 hr with VCF broth and then amplification of the cholera toxin target DNA fragment by the polymerase chain reaction was presented. VCF broth may be a useful tool for the selective enrichment of V. cholerae in bacterial examinations.

Bacteriological Techniques↗
PubMed1995

Chimeric TLS/FUS-CHOP gene expression and the heterogeneity of its junction in human myxoid and round cell liposarcoma.

Myxoid liposarcomas have a unique and specific t(12;16)q13;p11) chromosomal translocation. The breakpoint has recently been identified and shown to involve the TLS/FUS gene on chromosome 16 and the CHOP gene on chromosome 12. This translocation causes fusion of these genes resulting in the expression of a novel chimeric TLS/FUS-CHOP message. Using the polymerase chain reaction with primer sets derived from sequences of TLS/FUS and CHOP cDNAs, we could amplify three types of the fusion transcripts from seven of seven samples of myxoid and round cell liposarcomas. In six of the seven positive samples, two kinds of chimeric messenger RNAs were found that have been reported previously. However, the last sample had a novel chimeric message that had an extra sequence of 33 bp derived from the TLS/FUS gene. Thus, it was shown that these fusion transcripts had a varying extent of the sequence of TLS/FUS gene incorporated at the site of the fusion. However, the TLS/FUS-CHOP fusion transcripts were not detected in two pleomorphic liposarcomas or in three myxoid variants of malignant fibrous histiocytomas. Our findings indicate that in liposarcomas TLS/FUS-CHOP fusion transcripts have variations at the junction of chimeric messages, which was the case for Ewing's sarcoma. Detection of the chimeric message by reverse transcription polymerase chain reaction was also suggested to be a useful approach for the diagnosis of myxoid and round cell liposarcomas that have (12;16) translocation, and for distinguishing them from pleomorphic liposarcoma and myxoid variant of malignant fibrous histiocytomas.

Adult↗
PubMed1994

[A simple method for differentiation of hydrogen sulfide-producing bacteria by the pH-dependent EDTA-sensitivity test].

The pH-dependent EDTA-sensitivity test was performed to differentiate several strains of bacteria forming black colonies by the production of hydrogen sulfide on TCBS (thiosulfate-citrate-bile salt-sucrose agar) medium (tentatively designated as hydrogen-sulfide production bacteria). Two halotorelant strains of 16 hydrogen sulfide-producing strains showed the same bacteriological properties and isoprenoid quinone type as did a reference strain of Proteus mirabilis and were classified into the EDTA-insensitive group as were P. mirabilis and P. vulgaris. On the other hand, the other 14 halophilic strains, showing similar but not identical bacteriological properties or the isoprenoid quinone type to those of Shewanella putrefaciens IFO 3908, were classified into the "EDTA-sensitive (at pH 5)" group as were some species of the genus Vibrio. By the same sensitivity test, S. putrefaciens IFO 3908 was classified into the "EDTA-sensitive (at any pH)" group. These results indicate that the pH-dependent EDTA-sensitivity test is useful for differentiation of bacterial isolates producing hydrogen sulfide and having similar bacteriological properties.

Bacteria↗
PubMed1993

Estrogen-inducible pS2 protein is not the key regulatory component in the proliferation of human breast cancer cells (MCF-7).

Exposure of human breast cancer cells (MCF-7) to tumor promoters such as 12-O-tetradecanoyl phorbol 13-acetate (TPA) for 24 h at concentrations of 1-100 nM resulted in marked inhibition of DNA synthesis but a 3-5-fold increase in the amount of pS2 protein in the medium. These results support our previous suggestion that pS2 protein is not involved in the mechanism controlling proliferation of MCF-7 cells. During treatment with TPA, the intracellular content of pS2 protein was constant, suggesting that TPA did not induce secretion of pS2 protein but rather de novo synthesis of the protein. The increase in the pS2 protein content of the medium by TPA was inhibited by simultaneous addition of cycloheximide, but not by that of actinomycin D. Northern-blot hybridization analysis showed that the amount of pS2 mRNA was unchanged by treatment of the cells with TPA. These results indicate that TPA does not induce transcription of the pS2 gene, and suggest that the main effect of TPA results from the induction of translation of pS2 mRNA.

Biological Transport↗
PubMed1992

[Effect of pH on preferential antibacterial-activity of ethylenediaminetetraacetic acid (EDTA)].

Ethylenediaminetetraacetic acid (EDTA), a chelating agent, was examined for the antibacterial activity against 15 species of bacteria by treating with a 10mM solution at pH adjusted to 5.0, 7.0 or 9.0. All bacterial species tested were classified into three groups; tentatively named the pH5 EDTA-sensitive group comprising Vibrio cholerae and Staphylococcus aureus, the pH9 EDTA-sensitive group comprising Escherichia coli and Pseudomonas aeruginosa and the EDTA-nonsensitive group comprising Proteus mirabilis. The EDTA-sensitivity grouping may be used as a tool for preferential decontamination of certain bacteria in live edible fishes, although further experiments are needed to characterize more strains and also species of bacteria.

Bacteria↗
PubMed1990

Expression of the pS2 gene in human gastric cancer cells derived from poorly differentiated adenocarcinoma.

NH2-terminal amino acid sequence of the pS2 protein produced and secreted by human gastric cancer cells, MKN-45, was determined to be identical to that of MCF-7 cells. A clone encoding pS2 protein was isolated from the cDNA library constructed from MKN-45 cells. The nucleotide sequence was identical to that of pS2 cDNA previously isolated from human breast cancer cells, MCF-7, except for one nucleotide in the 3' untranslated region. Thus, in this cell line, the pS2 gene product is translated and secreted as in MCF-7 cells. RNA blot hybridization analysis revealed that pS2 gene was expressed well in two (MKN-45 and KATO-III; derived from poorly differentiated adenocarcinoma) but not in three cell lines (MKN-1, MKN-28 and MKN-74; from well differentiated adenocarcinoma), suggesting that expression of the pS2 gene depends on the state of cell differentiation. These results suggest that pS2 is expressed in human gastric cancer cells in an estrogen-independent manner and is possibly associated with the malignant state of cells.

Adenocarcinoma↗
PubMed1990

Complete primary structure of the human estrogen-responsive gene (pS2) product.

pS2 is a human gene whose transcription is directly triggered by estrogen in human breast cancer cells (MCF-7). We described here the complete primary structure of the pS2 gene product. The pS2 protein purified from conditioned medium of MCF-7 cells was S-pyridylethylated and digested with TPCK-trypsin. Five major fragments were obtained by reverse-phase HPLC. Amino acid sequence analysis of these tryptic peptides established that the pS2 protein comprises a 60-amino acid polypeptide. The sequence of the pS2 protein was completely identical to that deduced from the nucleotide sequence of the pS2 gene, if the signal polypeptide is excluded. Furthermore, two cDNA clones encoding an 84-amino acid precursor pS2 protein were isolated from a cDNA library which was constructed with RNA from MCF-7 cells cultured in the presence of estrogen. The nucleotide sequence of one clone (pS2B1) was identical to that of pS2 cDNA previously reported except for one nucleotide in the 3' untranslated region. The other clone (pS2B2) was longer by 73 nucleotides, at the 5' end, than pS2B1. The additional 73 nucleotides are located just upstream of the sequence of pS2B1 in the structure of the pS2 gene, indicating that the pS2 gene has two start sites for transcription. However, a mRNA molecule corresponding to pS2B1 but not to pS2B2 was detected in the cells on RNA blot hybridization analysis, indicating that one transcriptional start site is mainly used.

Amino Acid Sequence↗
PubMed1989

Hormonal regulation of synthesis and secretion of pS2 protein relevant to growth of human breast cancer cells (MCF-7).

We have recently identified human epidermal growth factor-like immunoreactive factor synthesized and secreted by human breast cancer cells (MCF-7) as a secretory protein encoded by the pS2 gene, the transcription of which is directly induced by estrogen. We demonstrated in this paper that synthesis and secretion of pS2 protein as well as pS2 mRNA were induced about 5-fold specifically by physiological concentrations of estrogen, which stimulated growth of the cells about 5-fold. Stimulative effects of estrogen on both cell growth and synthesis/secretion of pS2 protein were inhibited completely by actinomycin D, cycloheximide, and antiestrogen. However, the increase in DNA synthesis from 6 h after the start of treatment of the cells with estrogen preceded the increase in the amount of pS2 protein in the culture medium from 12 h after that. Furthermore purified pS2 protein did not stimulate DNA synthesis of the cells. These results suggest that induction of pS2 protein by estrogen is not involved in the growth-stimulating effect of estrogen in MCF-7 cells.

Androgens↗
PubMed1988

Identification of a polypeptide secreted by human breast cancer cells (MCF-7) as the human estrogen-responsive gene (pS2) product.

Human epidermal growth factor-like immunoreactive factor (designated as EGF-LI) synthesized and secreted by human breast cancer cells, strain MCF-7, was isolated in pure form. Thirty-seven micrograms of EGF-LI was purified by anion-exchange, gel permeation, and reverse-phase high-performance liquid chromatography from 2 liters of serum-free medium conditioned by the cells. The sequence of the first 36 amino acids from the N-terminus was determined with a gas-phase protein sequencer. Computer-assisted screening revealed, quite unexpectedly, this sequence to be completely identical to that of the translational product encoded by pS2, the human estrogen-responsive gene, over the region extending from residue 25 to 60 (Jakowlew, S. B. et al. (1984) Nucleic Acids Res., 12, 2861-2878).

Amino Acid Sequence↗
PubMed1983

A Japanese family with high density lipoprotein deficiency.

Two siblings with marked reduction of plasma high density lipoprotein (HDL) were found in a Japanese family. Their plasma cholesterol levels were very low (30-60 mg/dl), especially in the HDL fraction (0-1 mg/dl). The concentration of apolipoprotein (Apo) A-I in their plasma was 2-3 mg/dl and that of Apo A-II was 1.5-2.0 mg/dl, determined by means of a single radial immunodiffusion technique. An ultracentrifugally separated HDL fraction contained two different populations of lipoprotein particles, as shown by electron microscopy; a small particle with a diameter of 50-70 A and a relatively large particle at 200 A. Plasma lecithin: cholesterol acyltransferase activity was substantially retained in both cases. Hepatosplenomegaly was present and liver biopsy revealed lipid deposition in reticuloendothelial cells, although the tonsils were apparently normal. No severe atherosclerotic lesions were noticed. The results from these two cases were consistent with the characteristic features of homozygotes of familial HDL deficiency (Tangier disease). HDL cholesterol levels were relatively low in the parents and two children from one patient, which is consistent with the heterozygote state. Two other cases in the kindred were also found to have relatively low HDL cholesterol levels, besides these 4 cases of obligate heterozygotes. Apo A-I and Apo A-II levels in the plasma of the obligate heterozygotes, however, were within the normal range. Plasma low density lipoprotein in the patients moved faster in polyacrylamide gel electrophoresis than those of normal subjects, as did those in the heterozygotes.

Adult↗