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Biomedical subjects

Y Tanimoto

Publications and source records attributed to Y Tanimoto.

At least 19 recordsLinked to original sources
PubMed2006

Movement and diffusion of paramagnetic ions in a magnetic field.

The magnetic movement and thermal diffusion have been studied for Cu(2+) ions in solution. The Cu(2+) ion solution was spotted on the silica gel support and exposed to the magnetic field of 410 kOe(2) cm(-1) intensity x gradient. The Cu(2+) ions were attracted toward the filed center. The moving distance and diffusing distance were observed at various time intervals. It is shown that the Cu(2+) ions move in a large group composed of Cu(2+) ions and H(2)O molecules. The size of the group is approximately estimated to be of 4.6 mum diameter by the analysis of the drift velocity of the group and the Cu(2+) ion concentration in the group.

Journal Article↗
PubMed2006

Macromolecular crystallization in microgravity generated by a superconducting magnet.

About 30% of the protein crystals grown in space yield better X-ray diffraction data than the best crystals grown on the earth. The microgravity environments provided by the application of an upward magnetic force constitute excellent candidates for simulating the microgravity conditions in space. Here, we describe a method to control effective gravity and formation of protein crystals in various levels of effective gravity. Since 2002, the stable and long-time durable microgravity generated by a convenient type of superconducting magnet has been available for protein crystal growth. For the first time, protein crystals, orthorhombic lysozyme, were grown at microgravity on the earth, and it was proved that this microgravity improved the crystal quality effectively and reproducibly. The present method always accompanies a strong magnetic field, and the magnetic field itself seems to improve crystal quality. Microgravity is not always effective for improving crystal quality. When we applied this microgravity to the formation of cubic porcine insulin and tetragonal lysozyme crystals, we observed no dependence of effective gravity on crystal quality. Thus, this kind of test will be useful for selecting promising proteins prior to the space experiments. Finally, the microgravity generated by the magnet is compared with that in space, considering the cost, the quality of microgravity, experimental convenience, etc., and the future use of this microgravity for macromolecular crystal growth is discussed.

Animals↗
PubMed2005

Photodissociation of p-xylene in polar and nonpolar solutions.

The photodissociation of p-xylene at 266 nm in n-heptane and acetonitrile has been studied with use of nanosecond fluorescence and absorption spectroscopy. The p-methylbenzyl radical was identified in n-heptane and acetonitrile by its fluorescence, which was induced by excitation at 308 nm. The p-xylene radical cation was observed in acetonitrile by its absorption. In n-heptane, the decay rate of the S(1) state of p-xylene ((3.2 +/- 0.2) x 10(7) s(-1)) is equal to the growth rate of the p-methylbenzyl radical ((2.7 +/- 0.4) x 10(7) s(-1)), showing that the molecule dissociates via the S(1) state into the radical by C-H bond homolysis (quantum efficiency approximately 5.0 x 10(-3)). In acetonitrile, the formation of the p-xylene radical cation requires two 266 nm photons, and the decay rate of the radical cation ((1.6 +/- 0.2) x 10(6) s(-1)) equals the growth rate of the p-methylbenzyl radical ((2.0 +/- 0.2) x 10(6) s(-1)). This shows that the radical cation dissociates into the radical by deprotonation (quantum efficiency approximately 8.9 x 10(-2)).

Journal Article↗
PubMed2005

Occlusal force and condylar motion in patients with anterior open bite.

Patients with open bite often show a weak occlusal force and temporomandibular disorders (TMDs). If these are the main cause of open bite, it may be hypothesized that both pre-pubertal and adult open-bite patients would show a weak occlusal force and abnormal condylar motion. The purpose of this study was to test this hypothesis. Test group subjects consisted of 13 consecutive pre-pubertal and 13 adult patients with anterior open bite. They were compared with age-matched normal subjects. The adult open-bite group showed a weaker occlusal force and a shorter range of condylar motion compared with the control subjects. In the pre-pubertal subjects, however, there were no significant differences in the occlusal force and range of condylar motion between the open-bite and control groups. Therefore, these results suggest that a weak occlusal force or TMDs may not be the main cause of open bite.

Adolescent↗
PubMed2003

In vitro expansion of human basophils by interleukin-3 from granulocyte colony-stimulating factor-mobilized peripheral blood stem cells.

BACKGROUND: A number of studies support the belief that human basophils play an important role in allergic inflammation. The exact mechanism of basophil activation at the site of allergic inflammation, however, has not been well understood, mainly due to their low number in blood and difficulty in obtaining a sufficient number of highly purified basophils for investigation. OBJECTIVE: The purpose of this study is to expand human basophils in vitro with high yield and purity by culturing peripheral blood stem cells (PBSCs). METHODS: We collected PBSC-rich mononuclear cells containing CD34+ cells (0.15-4.9%) by leukapheresis from patients with malignant lymphoma and lung cancer during haematopoietic recovery after chemotherapy plus granulocyte colony-stimulating factor-induced mobilization. PBSC-rich mononuclear cells were cultured in the presence of IL-3. RESULTS: When PBSC-rich mononuclear cells containing more than 1% of CD34+ cells were cultured, 20.0-83.3% of the cells, mostly with a yield of >10%, were metachromatic cells after 3 weeks of culture. These cells resembled mature peripheral blood basophils morphologically when examined by light and electron microscopy. Flow cytometric analysis showed that they expressed both FcepsilonRI and FcgammaRII. FcepsilonRI cross-linking resulted in intracellular calcium mobilization, histamine release and synthesis of cysteinyl leukotrienes. The intracellular histamine content and the release of these chemical mediators triggered by anti-IgE antibodies were comparable to those of peripheral blood basophils. CONCLUSION: These findings suggest that PBSC-derived basophils expanded in vitro are morphologically and functionally mature and will be a useful tool for the analysis of basophil functions.

Adolescent↗
PubMed2002

Nonspecific interstitial pneumonia as pulmonary involvement of primary Sjögren's syndrome.

The pathologic patterns of lung involvement in nine patients with Sjögren's syndrome (SjS) are evaluated. The patients consisted of three males and six females, with a median age of 59 years. The SjS was diagnosed according to the criteria of the First International Seminar on SjS. In all patients, high-resolution computed radiographic scanning (HRCT) of the lungs was performed, and apparent honeycomb or microhoneycomb formation was observed in six patients. Pathologically, six patients were diagnosed with usual interstitial pneumonia (UIP), and three were diagnosed with nonspecific interstitial pneumonia/fibrosis (NSIP) (group II). There were no apparent honeycomb formations on HRCT in patients diagnosed with NSIP. In conclusion, NSIP is also a possible histologic classification of interstitial pneumonia associated with SjS.

Aged↗
PubMed2001

Stress caused by minimally invasive cardiac surgery versus conventional cardiac surgery: incidence of systemic inflammatory response syndrome.

The present study was conducted to evaluate the degree of stress in patients induced by minimally invasive cardiac surgery (MICS) in comparison with that caused by conventional cardiac surgery. We did this by assessing the incidence of systemic inflammatory response syndrome (SIRS). A total of 48 adult patients who underwent surgery for single valve disease were included in this study, 27 of whom underwent conventional surgery and 21 MICS. We evaluated the stress inflicted on the patients in these two groups by analyzing the duration and degree of SIRS and the level of C-reactive protein (CRP). SIRS was assessed by measuring body temperature, heart rate, respiratory rate, and white blood cell counts. There were no significant differences in the operating times, perfusion times, or aorta clamp times between the two groups; and the mean volume of blood transfusion did not differ significantly either. There was no significant difference in the incidence of SIRS or the mean duration of SIRS between the two groups. The CRP levels did not differ significantly between the two groups. Thus although MICS is superior to conventional cardiac surgery in that only a small skin incision is required, the stress experienced by the patient may be the same as that experienced by the patient undergoing conventional cardiac surgery.

Aged↗
PubMed2001

Lymphocyte subsets in lung tissues of interstitial pneumonia associated with untreated polymyositis/dermatomyositis.

This study was designed to evaluate the distribution of lymphocyte subsets in lung specimens obtained by surgical lung biopsy from 12 patients with interstitial pneumonia associated with untreated polymyositis/dermatomyositis (PM/DM). Differences of histological findings and distributions of lymphocyte subsets between PM and DM were also evaluated. Distributions of B lymphocytes, CD4-positive T lymphocytes, and CD8-positive T lymphocytes were evaluated immunohistochemically. Interstitial pneumonia was pathologically classified as basically nonspecific interstitial pneumonia (NSIP) in all patients. Immunohistochemically, the distribution of B lymphocytes was mostly restricted to inside and/or around lymphoid follicles. The CD4-positive T lymphocytes were distributed diffusely in fibrotic areas and unrelated to lymphoid follicles. Most CD8-positive T lymphocytes were diffusely distributed, especially in relatively normal alveoli. There were no significant differences in the distribution of lymphocyte subsets between PM and DM. Although the distribution of B lymphocytes and CD4- and CD8-positive T lymphocytes in the lung were different, there were no significant differences in distributions of lymphocyte subsets between PM and DM.

Aged↗
PubMed2001

A study of clinical features of cough variant asthma.

Patients with cough variant asthma (CVA) and classic asthma are frequently among subjects who present at clinics complaining of a chronic persistent cough. To reveal the features of CVA, we examined the differences in the clinical appearance between CVA and classic asthma. Ten CVA subjects and 11 classic asthmatics were enrolled in the study; they were recruited among patients who presented at the National Minamiokayama Hospital complaining of a chronic cough. The number of eosinophils in peripheral blood was 256 +/- 45.8/microl in CVA and 400 +/- 123/microl in classic asthma. Eosinophils represented 67% of the cells of sputum in CVA and 82% in classic asthma. Bronchial responsiveness to methacholine was Dmin 1.37 +/- 0.56 U in CVA and 0.71 +/- 0.46 U in classic asthma. There was no significant difference in these three parameters. There was only a significant difference in V25 between CVA and classic asthma, 80.0 +/- 6.9 and 52.2 +/- 10.0%, respectively. Eosinophil inflammation was almost the same in both CVA and classic asthma.

Asthma↗
PubMed2001

Motion of the human mandibular condyle during mastication.

It has been reported that loading to the mandible during closing movement makes the condylar path move more in the superior direction than that during the free closing movement. In this study, the hypothesis was tested that the displacement of the condyle on the chewing side is greater in the direction of the mandibular fossa than that on the non-chewing side. Using a six-degrees-of-freedom jaw movement recording system, we recorded condylar motion in 12 healthy adults without TMD, during the chewing of a large hard gummy jelly. The maximum displacements at the condyle on the chewing side from the maximum intercuspation (CO) position were significantly larger in the superior and medial directions at the initial stage and in the posterior direction at all stages (0.5 mm, 0.5 mm, and 0.6 mm, respectively) than those on the non-chewing side (0.0 mm, 0.1 mm, and 0.1 mm, respectively). This suggests that, in healthy adults, the condyles at CO are located in a position such that excessive load is not applied to the temporomandibular joint when there are the aforementioned displacements.

Adult↗
PubMed2001

Condylar motion in patients with reduced anterior disc displacement.

The influence of reduced anterior disc displacement on condylar motion has not been fully examined in young adults. Reduced anterior disc displacement was hypothesized to inhibit condylar motion. Using a six-degrees-of-freedom jaw-tracking system, we recorded bilateral condylar motion during maximum open-close jaw movement and gum-chewing on both sides in ten young adults with unilateral reduced anterior disc displacement and in ten control subjects without temporomandibular disorders. The bilateral condylar motion during both maximum open-close jaw movement and chewing on the disc-displacement side was inhibited in the test group. The condylar motion on the disc-displacement side during chewing on the non-disc-displacement side was also inhibited in the test group. These results suggest that the limitation of condylar motion on the disc-displacement side may influence condylar motion on the non-disc-displacement side during maximum open-close jaw movement, and mastication on the disc-displacement side in young adults.

Adolescent↗
PubMed2001

Novel protein kinase C delta isoform insensitive to caspase-3.

Protein kinase C delta (PKC delta) plays a key regulatory role in a variety of cellular functions, including apoptosis, as well as cell growth and differentiation. We previously reported that apoptosis was induced by pretreatment with 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7), an inhibitor of PKC, in mouse thymocytes. In the present study, we showed that a novel PKC delta isoform (PKC deltaII) was transiently expressed when thymocytes were pretreated with H-7. The analysis of the cDNA encoding PKC deltaII indicated that a 78 bp fragment was inserted into the caspase-3 sensitive site of the original PKC delta (PKC deltaI), presumably by alternative splicing. The PKC deltaII expressed in COS-1 cells was one product with a molecular mass of 81 kDa and with kinase activity similar to that of PKC deltaI. The expressed PKC deltaI protein (78 kDa) was in part cleaved into a 38 kDa fragment in vivo and in vitro, but the PKC deltaII protein was not. Cleavage of the PKC deltaI protein was inhibited by a specific inhibitor of caspase-3, indicating that PKC deltaII is insensitive to caspase-3. The PKC deltaII was highly expressed in the testis and ovary, and at a lower level in the thymocytes, brain and kidney, whereas PKC deltaI was detected in most tissues, suggesting that the function of PKC deltaII is different from that of PKC deltaI.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2000

Selected mutations in a mesophilic cytochrome c confer the stability of a thermophilic counterpart.

Mesophilic cytochrome c(551) of Pseudomonas aeruginosa (PA c(551)) became as stable as its thermophilic counterpart, Hydrogenobacter thermophilus cytochrome c(552) (HT c(552)), through only five amino acid substitutions. The five residues, distributed in three spatially separated regions, were selected and mutated with reference to the corresponding residues in HT c(552) through careful structure comparison. Thermodynamic analysis indicated that the stability of the quintuple mutant of PA c(551) could be partly attained through an enthalpic factor. The solution structure of the mutant showed that, as in HT c(552), there were tighter side chain packings in the mutated regions. Furthermore, the mutant had an increased total accessible surface area, resulting in great negative hydration free energy. Our results provide a novel example of protein stabilization in that limited amino acid substitutions can confer the overall stability of a natural highly thermophilic protein upon a mesophilic molecule.

Bacteria↗
PubMed2000

Inflammatory demyelinating polyradiculoneuropathy associated with interstitial lung disease.

A 58-year-old woman presented with inflammatory demyelinating polyradiculoneuropathy accompanied by sensory and motor disturbance and interstitial lung disease. Corticosteroid therapy led to a marked amelioration of both the neuropathy and the lung disease. We suggest that a demyelinating neuropathy is associated with an interstitial lung disease.

Anti-Inflammatory Agents↗
PubMed2000

[Urethral diverticula surrounding the urethra in women: report of 2 cases].

We report two cases of female urethral diverticula. A 49-year-old woman (case 1) complained of perineal pain when she voided urine. A 36-year-old woman (case 2) complained of perineal pain. In both cases, intravenous pyerography and urethrography revealed diverticula around their urethra, and we diagnosed them with urethral diverticula which surrounded their urethra by magnetic resonance imaging. We treated them by transvaginal diverticulectomy. Case 2 was successfully treated, but the diverticulum recurred after one year in case 1. There are over 200 reported cases of female diverticula in the Japanese literature, but a urethral diverticulum surrounding the urethra is rare.

Adult↗
PubMed1999

Male sterility in transgenic mice expressing activin betaA subunit gene in testis.

Activins and inhibins, which are endocrine regulators of anterior pituitary function, have also been reported to participate in the paracrine and autocrine regulation of reproductive function. To determine the in vivo effects of overexpressed activin/inhibin, we generated transgenic mice carrying the human activin/inhibin betaA subunit mini gene under the regulatory control of the mouse methallothionein promoter. In one of the transgenic line analyzed, the betaA subunit gene was preferentially expressed in the testis. Ectopic and allochronic expression of the betaA gene started at 3 weeks after birth and transgenic male mice became sterile in the ensuing several weeks. Histological analysis revealed testicular degeneration in these mice. The results from this transgenic line strongly support the in vivo activity of activin/inhibin in male reproductive functions.

Animals↗
PubMed1999

Benzodiazepine receptor agonists modulate thymocyte apoptosis through reduction of the mitochondrial transmembrane potential.

Peripheral-type benzodiazepines have been shown to exert immunological effects. In this study, we examined the effects of the peripheral-type benzodiazepines on murine thymocytes. Murine thymocytes that were incubated with the peripheral-type benzodiazepines underwent apoptosis associated with the collapse of mitochondrial transmembrane potential (delta psi(m)). The drugs stimulated dexamethasone- and etoposide-induced apoptosis with the enhanced collapse of delta psi(m). The central-type benzodiazepines had no effect on either the delta psi(m) or apoptosis. The reduction of delta psi(m) depended on protein synthesis and protein phosphorylation. These results suggest that the immunomodulating effect of benzodiazepines is in part due to the modulation of thymocyte apoptosis associated with the collapse of delta psi(m).

Animals↗