Biomedical subjects

T Hanawa

Publications and source records attributed to T Hanawa.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Development of patient-friendly preparations(II): Preparation and characterization of carrageenan gel containing polyethylene (oxide)].

The pharmaceutical utility of the allopurinol gel (APNgel) which consists of allopurinol (APN), carrageenan (kappa-CG or iota-CG) and polyethylene (oxide) (Alkox) was investigated as a possible material for an oral dosage preparation for ease in handling and/or swallowing. The gel formation was studied as a function of a variety of the concentration of Alkox and/or CG added. The APNgel gelled with kappa-CG was not appropriate to the oral dosage form because of its original taste and odor. In contrast, since iota-CG has no odor and/or taste, we added iota-CG as a gel material. From the investigation of the gelation behavior and the handling of the gelled material, the preferred composition of APNgel (Alkox: iota-CG% ratio) seemed to be that of 0.5:2.0, 1.0:2.0 and 2.0:2.0. The gel strength and the in vitro assessment of the adhesiveness of APNgels were evaluated using a creep meter. The gel strength of the APNgel was affected by the amount of the added Alkox. From the in vitro assessment of the adhesiveness of APNgels, the adhesiveness of APNgel increased with an increase in the amount of added Alkox. The release behavior of APN from APNgels was investigated by the paddle bead method, mimicking the chewing action in mouth. The APNgel was sheared by the beads and the release of APN completed within 480 s. From the results of the sensory test, APNgel consisting of 2.0% iota-CG and 1.0% Alkox seemed to be favorite to the jelly-like preparation.

Adult↗

PubMed2000

[Menopause and anxiety: focus on steroidal hormones and GABAA receptor].

In the menopause transition, around 35% of women will seek medical help for menopausal symptoms. At the climacteric, various symptoms such as forgetfulness, anxiety, depressive neurosis, abnormal sensation, hot flush and sleeplessness are often observed due to hypofunction of the ovaries. There is some indication that women become more anxious during times of relatively low level of estrogen and progesterone such as premenstrual syndrome, premenstrual dysphoric disorder, maternity blues and menopausal state. The exact mechanism behind it is still unclear but is probably related to the decrease of ovarian hormones, which may be triggering psychiatric mood disorders. It is known that ovarian hormones act on specific areas of the brain and appear to act as anxiolytics. Certain progesterone metabolites are anesthetic and have antiepileptic and anxiolytic properties. These steroids modulate the type A gamma-aminobutyric acid (GABAA)/benzodiazepine receptor. This may help explain the increased frequency of anxiety disorders and mood disorders in the early postmenopausal period. In addition, estrogen also improves memory and performance in patients with mild Alzheimer's dementia. These effects can be related to amplifying effects of estrogen on excitatory amino acids in the brain. This is suggested that gonadal steroidal hormones seemed to be one of the essential substances for the maintenance of the limbic system and forebrain function which regulated anxiety, mood, memory and cognitive functions in menopausal women.

Anti-Anxiety Agents↗

PubMed2000

[A new interventional strategy for Alzheimer's disease by Japanese herbal medicine].

A Japanese herbal medicine termed "Kami-Umtan-To (KUT)" was first described in Japanese literature in 1626, KUT consists of 13 different herbs, and it has been used for a long time in the treatment of a variety of neuropsychiatric problems including neurosis and insomnia. Recently, Yabe et al. have demonstrated that KUT increased both choline acetyltransferase (ChAT) and nerve growth factor at the protein and mRNA levels in cultured rat brain cells. Moreover, the same research group has reported that KUT improved mean latency on passive avoidance test in both basal for brain lesioned and aged rats. KUT significantly improved the survival rate, and increased the number of ChAT-positive neurons in aged rats. Here, we report a 12-month open clinical trial of KUT and combination of estrogen, vitamin E and NSAID to aim at slowing down the progression of Alzheimer's disease (AD). Twenty AD patients (MMSE score: 18.6 +/- 5.8) received extracts from original KUT herbs, and 7AD patients (MMSE score: 21.3 +/- 2.8) were placed on the combination therapy. Rate of cognitive decline as measured by change in MMSE score per year was significantly slower (p = 0.04, ANOVA) in the KUT group (1.4 points) and the combination group (0.4 points) as compared to 4.1 points in 32 control AD patients (MMSE score: 20.8 +/- 5.6) who received no medicines for AD. Any of CSF measures including tau. and A beta 1-42 did not differ significantly after KUT therapy. The efficacy of the KUT therapy was most obvious at 3 months. Our results suggest that traditional Japanese herbal medicine(s) may serve a new interventional strategy for AD.

Aged↗

PubMed2000

Cloning, sequencing, and transcriptional analysis of the dnaK heat shock operon of Listeria monocytogenes.

The complete dnaK operon of Listeria monocytogenes was isolated by chromosome walking using the previously cloned dnaK gene as a probe. Molecular analysis of the locus identified 6 genes in the order hrcA, grpE, dnaK, dnaJ, orf35, and orf29. Primer extension analysis revealed 3 transcription start sites-S1, S2, and S3-upstream of the hrcA, grpE, and dnaJ, respectively. The transcription from S1 was heat inducible. Analysis of the sequences revealed the consensus promoter sequences of gram-positive bacteria, P1 and P2 upstream of the hrcA and dnaJ, respectively. The hrcA gene and a regulatory sequence, designated CIRCE (controlling inverted repeat of chaperone expression), play a role in the regulation of expression of the dnaK locus in response to heat shock in several gram-positive bacteria. Their presence upstream of the dnaK locus in L. monocytogenes suggested a similar regulatory mechanism for the transcription initiated at the promoter, P1. Northern blot analysis led to the detection of 4 mRNA species of 4.9 kb, 3.6 kb, 3.6 kb, and 1.2 kb; the first 2 species were heat inducible. The current results indicate that 4 distinct transcripts directed by 3 promoters are involved in the expression of the dnaK operon of L. monocytogenes.

Amino Acid Sequence↗

PubMed1999

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Journal Article↗

PubMed1999

Amount of metallic ions released from Ti-Ni alloy by abrasion in simulated bioliquids.

The current density of Ti-56mass%Ni (Ti-50at.%) alloy after abrasion in simulated bioliquids was measured using a potentiostat to estimate the amount of metallic ions released from the alloy during repassivation and maturation. The current density in saline, saline with and without N2 bubbling, and Hanks' solutions with and without proteins after abrasion was measured and the amount of released ion was calculated from the integrated current density with time, assuming that Ti4+ and Ni2+ are equivalently released. No difference in the amount of released ion was observed between saline with and without N2 bubbling. Also, no difference was observed between saline and pH 7.4 Hanks' solution. More Ti4+ and Ni2+ were released in bioliquids with proteins than in saline with and without N2 bubbling (p < 0.05). That is, dissolved oxygen and inorganic ions in Hanks' solution did not influence the amount of released ion, but proteins influenced it. The release of metallic ions from metals and alloys in biological systems can be estimated by the methodology employed in this study.

Alloys↗

PubMed1999

Surface treatments of titanium in aqueous solutions containing calcium and phosphate ions.

Immersion treatment of titanium in aqueous solutions containing various kinds of ion concentrations of calcium and phosphate (pH 5.8, 7.0, and 8.0) were attempted to accelerate calcium phosphate precipitation on titanium in body fluid. The performance was confirmed using scanning electron microscopy, X-ray diffractometry, and Fourier transformed infrared absorption spectrometry with a reflection absorption spectrometer of the specimen immersed in Hanks' solution. Calcium phosphate precipitation on titanium in Hanks' solution is accelerated by the immersion treatment in aqueous solutions containing calcium and phosphate ions. The amount, composition, and shape of calcium phosphate precipitate vary according to the pH and ion concentrations of the solutions in which titanium is immersed. This method is effective for the surface treatment of inside pore narrow space of titanium materials.

Biocompatible Materials↗

PubMed1999

The Listeria monocytogenes DnaK chaperone is required for stress tolerance and efficient phagocytosis with macrophages.

Listeria monocytogenes is a facultative intracellular pathogen which can escape bactericidal mechanisms and grow within macrophages. The intracellular environment of macrophages is one of the most stressful environments encountered by an invading bacterium during the course of infection. To study the role of the major stress protein, DnaK, of L. monocytogenes in survival under intracellular stress induced by macrophage-phagocytosis as well as under extracellular environmental stresses, we cloned, sequenced, and analyzed the dnaK locus from L. monocytogenes. Then we constructed an insertional mutation in the dnaK gene by homologous recombination and characterized it. Sequencing has revealed that the dnaK locus consists of four open reading frames in the order hrcA-grpE-dnaK-dnaJ. The mutant grows neither at temperatures above 39 degrees C nor under acidic conditions e.g. pH 3.0. Using the macrophage cell line JA-4, the ability of the dnaK mutant to grow intracellularly was examined. Immediately after phagocytosis, the number of viable dnaK mutant bacteria found within macrophages was significantly lower compared to that of intracellular wild type bacteria. However, following a 1-3 h latency period, the mutant multiplied in a similar fashion to the wild type within macrophage cells. A quantitative analysis of intracellular bacteria in macrophage cells by microscope and a binding assay of bacteria to the surface of macrophages by ELISA revealed that the lower number of viable dnaK mutant in macrophages after phagocytosis is due to the low efficiency of phagocytosis resulting from the reduced binding capacity of the dnaK mutant. These results demonstrate that DnaK of L. monocytogenes is essentially required for survival under high temperatures and acidic conditions. Though it does not largely contribute to the survival of L. monocytogenes in macrophage cells, it is essential for efficient phagocytosis. This is the first evidence that DnaK is required for the efficient phagocytosis of a facultative intracellular pathogen with macrophages.

Amino Acid Sequence↗

PubMed1998

Repassivation of titanium and surface oxide film regenerated in simulated bioliquid.

The change in potential during repassivation of titanium in artificial bioliquids was examined, and the regenerated surface oxide film on titanium was characterized using X-ray photoelectron spectroscopy and Auger electron spectroscopy to elucidate the repassivation reaction of titanium in a biological system. The repassivation rate in Hanks' solution was slower than that in saline and was not influenced by the pH of the solution. This indicates that more titanium ions dissolve in a biological system than hitherto was predicted when the surface film is destroyed. Phosphate ions are taken up preferentially in the surface film during regeneration, and the film consists of titanium oxide and titanium oxyhydroxide containing titanium phosphate. Calcium ions and phosphate ions are adsorbed by the film after regeneration, and calcium phosphate or calcium titanium phosphate is formed at the outermost surface. Ions constituting Hanks' solution other than calcium and phosphate were absent from the surface oxide.

Biocompatible Materials↗

PubMed1998

Amount of hydroxyl radical on calcium-ion-implanted titanium and point of zero charge of constituent oxide of the surface-modified layer.

To compare the surface properties of calcium-ion (Ca2+)-implanted titanium with those of titanium and to investigate the mechanism of bone conductivity of Ca2+-implanted titanium, amounts of hydroxyl radical of Ca2+-implanted titanium and titanium were estimated. Also, the point of zero charge (p.z.c.) of oxide constituting surface oxides of Ca2+-implanted titanium and titanium was determined. Results showed that the amount of active hydroxyl radical on Ca2+-implanted titanium was found to be significantly larger than that on titanium, indicating that the number of electric-charging sites of Ca2+-implanted titanium in electrolyte is more than that of titanium. The p.z.c. values of rutile (TiO2), anatase (TiO2), and perovskite (CaTiO3), were estimated to be 4.6, 5.9, and 8.1, respectively. Thus, Ca2+-implanted titanium surface is charged more positively in bioliquid than titanium, accelerating the adsorption of phosphate ions.

Journal Article↗

PubMed1998

Effect of cAMP- and cGMP-related drugs on porcine cultured ciliary muscle.

We studied in this work the compounds which affect the contraction of ciliary muscle and are potential ocular hypotensive drugs, and second messengers produced by the compounds. Using second-passaged porcine cultured ciliary muscle, single cell contraction was used for assay. Cell contraction by carbachol was affected by isobutyl methylxanthine, forskolin, dibutyryl cGMP and sodium nitroprusside (SNP). Forskolin increased intracellular cAMP while SNP stimulated cGMP formation. The results indicate that these cAMP- or cGMP-related compounds could affect the contraction of ciliary muscle like prostaglandins and could therefore have a potential to reduce intraocular pressure.

1-Methyl-3-isobutylxanthine↗

PubMed1998

Estimation of residual stress in dental porcelain by laser-Raman spectroscopy.

Residual stress in the surface of dental porcelain was estimated using laser Raman spectroscopy. Sixteen different magnitudes of residual stress were generated in commercial porcelain disks by tempering, ion exchange, and slow cooling. The specimens were analyzed using a laser-Raman spectrometer with an Ar+ laser. The Raman shift of the largest peak near 500 cm-1 originating from silica was used as an indicator of the level of residual stress. For comparison, the residual stress in the specimen was estimated by the indentation micro-fracture method. The Raman shift of the porcelain increased with increasing residual stress at 3.7 x 10(-2) cm-1/MPa (R2 = 0.89). The increase in the Raman shift corresponded to the increase in compressive stress. In addition, the value of full width at half maximum on the peak corresponded to the residual stress (-1.57 x 10(-1) cm-1/MPa: R2 = 0.82). These results revealed that the increase of residual stress in porcelain clearly appears on the Raman spectrum as an increase in the Raman shift. It is thus feasible to estimate residual stress in porcelain by laser-Raman spectroscopy.

Aluminum Silicates↗

PubMed1998

[Limited operation for stage I lung cancer: a retrospective study].

Although lobectomy is standard therapy for Stage I non-small cell lung cancer, it often cannot be performed in poor-risk patients. In this report, we describe the results of a retrospective study to assess the usefulness of limited operation for stage I lung cancer. Over a 21-year period, 1,286 lung cancers were resected at our center. Among the 497 patients with stage I lung cancer, 36 sublobar resections were performed. There was only one surgery-related death, and the 5-year survival rate was 46% for all patients. At 5 years, survival was 69.2% for patients with squamous cell carcinoma and 33.7% for patients with adenocarcinoma. Survival rates were higher in patients who underwent mediastinoscopy than those who did not, and depended on histological findings and accurate pathological staging.

Adenocarcinoma↗

PubMed1998

[A pulmonary tumorlet with caseous granuloma associated with atypical mycobacterium].

We encountered a case of pulmonary tumorlet with caseous granuloma associated with atypical mycobacterium. A 73-year-old woman was admitted to the hospital because a chest x-ray film showed enlargement of an abnormal shadow in the middle lobe of the right lung. Primary lung cancer was suspected and right middle lobectomy was performed. Acid-fast bacilli (Gaffky 1) were found in a caseous lesion and examination of intraoperatively obtained frozen specimens showed caseous granulomas. The bacilli were later identified as Mycobacterium avium complex. The permanent specimen showed a minute lesion consisting of small clusters of epithelial cells resembling carcinoid tumor in contact with granulomatous tissue. Histopathological examination revealed argyrophilia on Grimelius stain and immunoreactivity to chromogranin-A in the clusters of epithelial cells. Although these results are consistent with small cell carcinoma or peripheral carcinoid tumor, pulmonary tumorlet was diagnosed because of the lesion's small and minimal cytologic atypia, and because of chronic pulmonary damage around the lesion. Pulmonary tumorlets are minute, usually microscopic, tumor-like lesions mostly found in damaged lung tissue obtained at autopsy or during surgery. Morphological diagnosis is sometimes very difficult, but recently these lesions have been regarded as hyperplastic lesions arising in pulmonary neuroendocrine cells (Kultschitzky cells) and caused by chronic pulmonary damage, such as hypoxia and inflammation. Pulmonary tumorlets must be considered in the differential diagnosis of minute lesions suspected to be small cell carcinoma or peripheral carcinoid tumor.

Aged↗

PubMed1998

Relationship between expression of HSP60, urease activity, production of vacuolating toxin, and adherence activity of Helicobacter pylori.

The relationship between the expression of heat shock protein 60 (HSP60) of Helicobacterpylori on the bacterial surface and its pathogenic factors of urease activity, production of vacuolating toxin, and adherence to human gastric carcinoma cells was examined. There was no correlation between urease activity, production of vacuolating toxin, and the expression of HSP60. However, there was a significant correlation between the adherence activity to human gastric carcinoma MKN45 cells and the expression of HSP60 (correlation coefficient; r = 0.68). In an inhibition assay with anti-HSP60 antibody, we examined the adhesion of H. pylori to MKN45 cells. The adherence of 3 of 13 H. pylori strains was inhibited by anti-HSP60 antibody. The results suggest that H. pylori HSP60 may be associated with the adhesion of H. pylori to human gastric cells.

Bacterial Adhesion↗

PubMed1997

Arginase of Bacillus brevis Nagano: purification, properties, and implication in gramicidin S biosynthesis.

An arginase [EC 3.5.3.1] was purified to homogeneous state from a gramicidin S-producing Bacillus brevis Nagano. The enzyme has a molecular weight of about 180,000 on gel filtration. The subunit molecular weight is 32,000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis, indicating that the enzyme is hexameric. The optimum pH is found near 10.0. Mn2+ is essential for its activity and Fe2+, Co2+, Ni2+, and Mg2+ cannot replace Mn2+. The enzyme is highly specific for L-arginine with a K(m) value of 12.8 mM for L-arginine, which is similar to that of liver-type arginase in ureotelic animals. B. brevis arginase is apparently induced by the addition of L-arginine to the glutamate medium. The increased formation of L-ornithine, a constituent amino acid of gramicidin S, by arginase may be involved in the accelerated production of gramicidin S by B. brevis in the presence of L-arginine in the growth medium.

Arginase↗

PubMed1997

Surface modifications of titanium in calcium-ion-containing solutions.

The surface of titanium was modified in calcium-ion-containing solutions to improve bone conductivity. Three kinds of aqueous solutions for the modification were prepared using calcium nitrate, calcium chloride, and calcium oxide. The pH values of the solutions were 3.9, 7.4, and 12.6, respectively. At first, anatase powder was immersed in the solutions of 7 days to confirm the effect of the solutions on the modification. As a result, calcium titanate was formed on the anatase powder, indicating that the titanium surface was possibly modified by the solutions. Titanium plates were then immersed in the solutions at ambient temperature for 7 days, washed by deionized water, and dried. X-ray photo-electron spectroscopy of surface-modified titanium revealed that the surface-modified layer contained calcium hydroxide and/or calcium titanate. The surface-modified layer in which titanium was modified was thickest in this order: calcium oxide, calcium chloride, and calcium nitrate solutions. Apatite was formed on the surface-modified titanium in Hanks' solution while apatite was undetected on unmodified titanium. Therefore, the surface modification of titanium may improve bone conductivity. The amount of apatite corresponded to the thickness of the surface-modified layer and the amount of calcium in the layer.

Apatites↗

PubMed1997

Early bone formation around calcium-ion-implanted titanium inserted into rat tibia.

Rat tibia tissue into which calcium ion (Ca2+)-implanted titanium was surgically placed was histologically analyzed to investigate the performance of the Ca(2+)-implanted titanium as a biomaterial. Calcium ions were implanted into only one side of titanium plates at 10(17) ions/cm2 and the Ca(2+)-treated titanium was surgically implanted into rat tibia for 2, 8, and 18 days. Tetracycline and calcein were used as hard-tissue labels. After excision of the tibia, the tissues were fixed, stained, embedded in polymethyl methacrylate, and sliced. The specimens were observed using a fluorescence microscope. A larger amount of new bone was formed on the Ca(2+)-treated side than on the untreated side, even at 2 days after surgery. In addition, part of the bone made contact with the Ca2(+)-treated surface. On the other hand, bone formation on the untreated side was delayed and the bone did not make contact with the surface. Mature bone with bone marrow formed in 8 days. Neither macrophage nor inflammatory cell infiltration was observed. The results indicated that Ca(2+)-implanted titanium is superior to titanium alone for bone conduction.

Animals↗