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Biomedical subjects

H Matsuzaki

Publications and source records attributed to H Matsuzaki.

At least 19 recordsLinked to original sources

Osteopontin as biomarker in early invasion by squamous cell carcinoma in tongue.

BACKGROUND: Osteopontin (OPN) expression in squamous cell carcinoma (SCC) of the tongue has not been clearly elucidated. METHODS: We selected 46 cases of tongue SCC and investigated the expression of OPN by immunohistochemical staining. The immunopositive reaction and score for each case were semiquantitatively evaluated. RESULTS: Scores were significantly higher in carcinoma nests than in neighboring normal epithelium or epithelial dysplasia. The OPN was expressed clearly in the cytoplasm of carcinoma cells. In cases of early invasive carcinoma, in particular, expression of OPN showed a remarkable increase at the invasion front compared with the non-invaded regions. However, there was no significant correlation between expression of OPN in the primary tumor nest and lymphatic metastasis, recurrence, or survival rate. CONCLUSION: This suggests that OPN is a useful biomarker of early invasion by SCC in tongue.

Adult↗

Phospho-regulation of human protein kinase Aurora-A: analysis using anti-phospho-Thr288 monoclonal antibodies.

Mammalian Aurora-A is related to a serine/threonine protein kinase that was originally identified by its close homology with Saccharomyces cerevisiae Ipl1p and Drosophila melanogaster aurora that are key regulators in the orchestration of mitotic events. The protein level of Aurora-A, its peak kinase activity during mitosis, and its activation have been attributed to phosphorylation. Here we show that this enzyme is an arginine-directed kinase and define its substrate specificity. We also found that Thr288 within the activation loop is a critical residue for activating phosphorylation events in vitro and that it is spatiotemporally restricted to a brief window at mitosis on duplicated centrosomes and on spindle microtubules proximal to the poles in vivo. Immunodepletion assays indicated that an upstream kinase(s) of Aurora-A might exist in mammalian cells in addition to autophosphorylation. Furthermore, human activated Aurora-A forms complexes with the negative regulator protein serine/threonine phosphatase type 1 (PP1) that was negatively phosphorylated on Thr320. Interestingly, phospho-specific Aurora-A monoclonal antibodies restrain Aurora-A kinase activity in vitro, providing further therapeutic avenues to explore.

Amino Acid Sequence↗

Ultrafast photoinduced melting of a spin-Peierls phase in an organic charge-transfer compound, K-tetracyanoquinodimethane.

Ultrafast photoinduced phase transition in a spin-Peierls (SP) system of K-tetracyanoquinodimethane (K-TCNQ) was studied by femtosecond (fs) reflection spectroscopy. Photocarriers destabilize the SP phase, resulting in a decrease in molecular dimerization within 400 fs. Such a melting of the SP phase drives three kinds of coherent oscillations. By comparing the oscillations with the Raman bands activated by the dimerization, we show that the oscillation of 20 cm-1 is due to an LO phonon, and it plays an important role for the stabilization of the SP phase.

Journal Article↗

Endoscopic carpal tunnel release in the elderly.

The present study is aimed to clarify the postoperative outcome of endoscopic carpal tunnel release in elderly patients with carpal tunnel syndrome. Endoscopic carpal tunnel release was performed on 37 hands of 27 patients (2 men, 25 women) who were aged 70 years or older and clinically and electrophysiologically diagnosed with carpal tunnel syndrome. Mean age at the time of surgery was 74.5 years (range: 70-85 years). Mean postoperative follow-up was 35.5 months (range: 12-114 months). Pain was present preoperatively in 20 hands, but quickly resolved postoperatively in all cases. Numbness completely disappeared in 13 of 37 hands (35.1%), but some degree of numbness remained in the remaining cases. Preoperative severity of thenar muscle atrophy was none in 4 hands, mild in 7 hands, moderate in 12 hands and severe in 14 hands. Postoperative severity of thenar muscle atrophy at final follow-up was none in 13 hands, mild in 16 hands, moderate in 2 hands and severe in 6 hands, confirming that thenar muscle atrophy improves even in elderly patients. However, moderate or severe thenar muscle atrophy remained in 8 hands (21.6%). Endoscopic carpal tunnel release should be considered in the elderly, even though clinical symptoms may not improve substantially in advanced cases.

Age Factors↗

Moderate magnesium-restricted diet affects bone formation and bone resorption in rats.

This study investigated the effects of moderate magnesium (Mg)-restricted diet on bone formation and bone resorption in rats. Weanling Wistar strain rats were randomly divided into three dietary groups of 6 rats each and fed their respective diets; a control diet containing 0.05% Mg (C), a half Mg diet containing 0.025% Mg (1/2Mg), or a one-fifth Mg diet containing 0.01% Mg (1/5Mg), for 21 days. Serum osteocalcin level was significantly reduced with decreasing dietary Mg level. Urinary excretion of C-terminal telopeptide of type 1 collagen was significantly higher in the 1/5Mg group than in the C group. Serum insulin-like growth factor-1 (IGF-1) level was significantly lower in the 1/2Mg and 1/5Mg groups than in the C group. Serum soluble receptor activator of nuclear factor-kappaB ligand (sRANKL) level was significantly higher in the 1/2Mg and 1/5Mg groups than in the C group. These results showed that a moderate Mg-restricted diet induced a decrease in bone formation and an increase in bone resorption. Furthermore, these changes of bone formation and bone resorption might be caused by serum IGF-1 and sRANKL levels, respectively.

Animals↗

Magnesium-deficient diet-induced reduction in protein utilization in rats is reversed by dietary magnesium supplementation.

We investigated the effect of dietary magnesium (Mg) level on protein utilization in rats. Male Wistar rats were fed a control diet (control group) and a Mg-deficient diet (Mg-deficient group) for 28 days. After 28 days, the diet of half of the Mg-deficient group (recovery group) was changed from the Mg-deficient diet to the control diet for either 7 or 14 days. After 28 days, final body weight, weight gain and food efficiency were significantly decreased due to the Mg-deficient diet. Apparent Mg absorption, Mg retention and serum Mg levels were also significantly decreased due to the Mg-deficient diet. Furthermore, the Mg-deficient group showed a significant increase in urinary nitrogen (N) excretion and significant decreases in N retention and serum albumin level. At day 7 and 14 after changing the Mg-deficient diet to the control diet, apparent Mg absorption, Mg retention and serum Mg levels were significantly increased in the recovery group as compared with those in the Mg-deficient group. However, with regard to final body weight, weight gain and food efficiency, no significant differences were observed between the Mg-deficient group and the recovery group. At day 14 after changing the diet, urinary N excretion was significantly decreased and N retention was significantly increased in the recovery group as compared with the Mg-deficient group. At day 7 and 14 after changing the diet, the serum albumin level was also significantly increased in the recovery group as compared with that in the Mg-deficient group. These results suggest that: 1) the Mg-deficient diet depresses protein utilization; 2) the Mg-deficient diet-induced impairment of protein utilization is reversed by dietary Mg supplementation; and 3) the Mg-deficient diet-induced growth retardation is not completely reversed after 14 days of Mg supplementation.

Animals↗

Effect of dietary magnesium supplementation on bone loss in rats fed a high phosphorus diet.

The purpose of this study was to investigate the effect of dietary magnesium (Mg) supplementation on bone loss in rats fed a high phosphorus (P) diet. Weanling Wistar strain rats were randomly divided into four dietary groups of 6 rats each and fed their respective diets; a diet containing 0.3% P and 0.05% Mg (C), a diet containing 1.5% P and 0.05% Mg (HP), a diet containing 0.3% P and 0.15% Mg (HMg), or a diet containing 1.5% P and 0.15% Mg (HPMg), for 21 days. Compared to the C and HMg groups, serum parathyroid hormone (PTH) concentration was significantly higher in the HP and HPMg groups. Serum osteocalcin concentration and urinary excretion of C-terminal telopeptides of type I collagen (CTx), markers of bone turnover, were significantly higher in the HP and HPMg groups than in the C and HMg groups. Dietary Mg supplementation had no significant effects on serum PTH and osteocalcin concentrations, while urinary excretion of CTx was significantly lower in the HPMg group than in the HP group. These results suggested that dietary Mg supplementation suppressed bone resorption due to high P diet.

Absorption↗

Effects of high calcium intake on bone metabolism in magnesium-deficient rats.

We examined the effects of high calcium (Ca) intake on bone metabolism in magnesium (Mg)-deficient rats. Male Wistar rats were divided into three groups, with each group having a similar mean body weight, and fed a control diet (control group), a Mg-deficient diet (Mg-deficient group) or a Mg-deficient Ca-supplemented diet (Mg-deficient Ca-supplemented group) for 14 d. Femoral Ca content was significantly lower in the Mg-deficient Ca-supplemented group than in the control group and Mg-deficient group. Femoral Mg content was significantly lower in the Mg-deficient group and Mg-deficient Ca-supplemented group than in the control group. Furthermore, femoral Mg content was significantly lower in the Mg-deficient Ca-supplemented group than in the Mg-deficient group. Serum osteocalcin levels (a biochemical marker of bone formation) were significantly lower in the two Mg-deficient groups than in the control group. As a biochemical marker of bone resorption, urinary deoxypyridinoline excretion was significantly higher in the Mg-deficient Ca-supplemented group than in the control group and Mg-deficient group. The results in the present study suggest that high Ca intake had no preventive effect on alteration of bone metabolism in Mg-deficient rats.

Absorption↗

Radiographic examination of dentigerous cysts in the transitional dentition.

OBJECTIVES: To examine radiographically the relationship between the deciduous tooth and dentigerous cyst of the permanent successor during the transitional dentition. METHODS: From a retrospective review of all patients who visited our institution from April 1988 to August 2001, 70 patients under 16 years of age who had histologically confirmed dentigerous cysts that had developed from the central incisor to the second premolar were identified. These 70 patients were investigated using panoramic and periapical radiographs. RESULTS: In most cases (54 cases; 77.1%) the cyst was in the premolar region. Of the 54 premolars with dentigerous cysts, the overlying deciduous tooth had already been lost in 7 cases. Of the 47 remaining premolars with associated deciduous tooth, 35 (74.5%) had bone resorption of the periapical or bifurcation region, or irregular resorption of the associated deciduous tooth. Of the remaining 12 deciduous teeth with no periapical lesions, 9 had been treated with root canal therapy. Thus, 44 of these 47 cases (93.6%) had the possibility of inflammation at the deciduous tooth associated with the dentigerous cyst. Evidence from one case in the present study suggesting the process by which cyst development occurs is also given. CONCLUSION: Inflammatory change at the apex of the deciduous tooth may bring on a dentigerous cyst of the permanent successor.

Adolescent↗

Radiographic examination of mesiodens and their associated complications.

OBJECTIVES: To examine mesiodens with regard to their status, their influence on adjacent teeth and their alteration during the follow-up period. METHODS: From retrospective reviews of all patients who visited our institution from 1990-2001, we identified 200 patients (256 mesiodentes) who were shown to have mesiodentes on the basis of a periapical radiograph, a panoramic radiograph or an axial radiograph. RESULTS: The number of supernumerary teeth was one in 146 cases (73%), two in 52 cases (26%) and three in 2 cases (1%). Of 256 mesiodentes, the direction of the crown of the mesiodens was inverted in 172 (67%), in a normal direction in 69 (27%) and in a horizontal direction with regard to the tooth axis in 15 (6%). Of the 147 mesiodentes for which axial radiography was performed, 131 (89%) were located at a palatal site against the dental arch, 16 (11%) overlapped the dental arch and none were at a labial site. Of our 200 cases, a delay of eruption of the permanent central incisor was seen in 12 (6%), malposition or rotation of the central incisor in 5 (2.5%) and dentigerous cyst formation arising from mesiodens in 22 (11%). Marked movement of the mesiodens was seen in 10 cases during the follow-up period of 5-7 years. Some complication arising from mesiodens was seen in 19.5% of all cases in our research. CONCLUSION: Although mesiodentes are not caused by malocclusion, they may cause it. A long period of impaction of mesiodentes may bring about dentigerous cyst formation or movement of the mesiodentes.

Adolescent↗

Ultrafast optical switching to a metallic state by photoinduced mott transition in a halogen-bridged nickel-chain compound.

We demonstrate the ultrafast photoinduced Mott transition from a charge transfer insulator to a metal in a halogen-bridged Ni-chain compound by pump-probe reflection spectroscopy. Upon the irradiation of a 130-femtosecond laser pulse, the spectral weight of the gap transition is transferred to the inner-gap region. When the photoexcitation density exceeds 0.1/Ni site, the Drude-like high-reflection band appears in the infrared region, signaling the formation of a metallic state. The photogeneration of the metallic state and the subsequent recovery to the original gapped state occur within a few picoseconds.

Journal Article↗

Photoinduced phase transition in an organic radical crystal with room-temperature optical and magnetic bistability.

A phase control by photoirradiation is successfully achieved in a spin-Peierls system of the organic radical crystal, 1,3,5-trithia-2,4,6-triazapentalenyl (TTTA), which exhibits optical and magnetic bistability around room temperature with a large hysteresis loop. A nanosecond laser pulse is found to induce a transition from a diamagnetic low-temperature phase to a paramagnetic high-temperature phase both inside (296 K) and outside (11 K) the hysteresis loop. Comparison of the excitation energy dependence between transition efficiency and photoconductivity suggests that the photoinduced transition is driven by suppression of the spin-Peierls instability by the accumulation of photocarriers.

Journal Article↗

Novel optical and magnetic bistability and photoinduced transition in a one-dimensional halogen-bridged binuclear pt complex.

In iodine-bridged binuclear Pt compounds, R(4)[Pt(2)(pop)(4)I]nH(2)O and R(')(2)[Pt(2)(pop)(4)I]nH(2)O (pop=P(2)O5H2-2), electronic structures on the PtPtI chains have been controlled between a diamagnetic charge-density-wave (CDW) state and a paramagnetic charge-polarization (CP) state by modification of the counterions (R, R') located between chains. In the R=(C2H5)2NH+2 compound, a pressure-induced CP to CDW transition with a drastic color change is identified. This transition is accompanied by a large hysteresis loop within which photoinduced transition between CDW and CP can be driven by selecting the excitation photon energy.

Journal Article↗

Comparison of radiographic and MRI features of a root-diverging odontogenic myxoma, with discussion of the differential diagnosis of lesions likely to move roots.

Lesions that can produce divergence of the roots of teeth in the mandible include odontogenic cysts (odontogenic keratocysts, lateral periodontal cysts and radicular cysts), ameloblastomas, odontogenic myxomas, central giant cell granulomas, adenomatoid odontogenic tumors and aneurismal bone cysts, and other tumors. Moreover most benign jaw lesions can do this occasionally. However, when lesions--which show interradicular tear-shaped radiolucencies--are small it is often difficult to interpret them radiographically, because they do not show characteristic radiographic features. We describe a comparison of radiographic and magnetic resonance (MR) features of a root-diverging odontogenic myxoma, with discussion of the differential diagnosis of lesions likely to move roots. In addition, we discuss radiographic and MR features of possible lesions, which show similar radiographic findings to odontogenic myxoma.

Adult↗

Static gamma-motoneurones couple group Ia and II afferents of single muscle spindles in anaesthetised and decerebrate cats.

Ideas about the functions of static gamma-motoneurones are based on the responses of primary and secondary endings to electrical stimulation of single static gamma-axons, usually at high frequencies. We compared these effects with the actions of spontaneously active gamma-motoneurones. In anaesthetised cats, afferents and efferents were recorded in intramuscular nerve branches to single muscle spindles. The occurrence of gamma-spikes, identified by a spike shape recognition system, was linked to video-taped contractions of type-identified intrafusal fibres in the dissected muscle spindles. When some static gamma-motoneurones were active at low frequency (< 15 Hz) they coupled the firing of group Ia and II afferents. Activity of other static gamma-motoneurones which tensed the intrafusal fibres appeared to enhance this effect. Under these conditions the secondary ending responded at shorter latency than the primary ending. In another series of experiments on decerebrate cats, responses of primary and secondary endings of single muscle spindles to activation of gamma-motoneurones by natural stimuli were compared with their responses to electrical stimulation of single gamma-axons supplying the same spindle. Electrical stimulation mimicked the natural actions of gamma-motoneurones on either the primary or the secondary ending, but not on both together. However, gamma-activity evoked by natural stimuli coupled the firing of afferents with the muscle at constant length, and also when it was stretched. Analysis showed that the timing and tightness of this coupling determined the degree of summation of excitatory postsynaptic potentials (EPSPs) evoked by each afferent in alpha-motoneurones and interneurones contacted by terminals of both endings, and thus the degree of facilitation of reflex actions of group II afferents.

Action Potentials↗

Tuning of electronic structures of quasi-one-dimensional bromo-bridged Ni(III) complexes with strong electron-correlation by doping of Co(III) ions, [Ni(1-x)Co(x)(Chxn)(2)Br]Br(2).

We have succeeded in synthesizing the Ni(III) complexes doped by Co(III) ions, [Ni(1-x)Co(x)(chxn)(2)Br]Br(2) (x = 0, 0.043, 0.093, and 0.118) by using an electrochemical oxidation method. The single-crystal reflectance spectrum of x = 0.118 shows an intense CT band about 0.5 eV, which is lower than that of [Ni(chxn)(2)Br]Br(2) (1.3 eV). The single-crystal electrical conductivities at room temperature of these compounds increase with increase of the amounts of doping of Co(III) ions. In the ESR spectra, peak-to-peak line widths DeltaH(pp) at room temperature change about 600 G in [Ni(chxn)(2)Br]Br(2) to 200 G in x = 0.118. Such a large x dependence of DeltaH(pp) seems to be ascribed to the increasing contribution from the increasing Curie spins which have smaller line width. Therefore, we have tuned the electronic structures of quasi-one-dimensional bromo-bridged Ni(III) complexes with strong electron correlations by doping of Co(III) ions.

Journal Article↗

UV-induced tyrosine phosphorylation of PKC delta and promotion of apoptosis in the HaCaT cell line.

Protein kinase C delta (PKC delta) is activated through tyrosine phosphorylation and is involved in apoptosis induction in the H(2)O(2)-treated fibroblasts. In the human keratinocyte HaCaT cell line, ultraviolet radiation, which induces apoptosis, promoted tyrosine phosphorylation and activation of PKC delta, but neither enhanced threonine phosphorylation in the activation loop nor generated the catalytic fragment of the PKC isoform. Tyrosine phosphorylation of PKC delta was prevented by a radical scavenger, N-acetyl-l-cysteine, and by a tyrosine kinase inhibitor, genistein, in the ultraviolet-irradiated keratinocyte cell line. Ultraviolet radiation-induced apoptosis was attenuated by N-acetyl-l-cysteine and genistein as well as by a PKC inhibitor, bisindolylmaleimide I. These results indicate that reactive oxygen species generated by ultraviolet radiation enhance tyrosine phosphorylation of PKC delta, and the PKC isoform thus activated by the modification reaction contributes to induction of apoptotic cell death in keratinocytes.

Antineoplastic Agents↗

Symptoms of thoracolumbar junction disc herniation.

STUDY DESIGN: A retrospective clinical review of patients with thoracolumbar junction disc herniation. OBJECTIVES: To evaluate the clinical features of thoracolumbar junction disc herniation and to prepare a chart for the level diagnosis in the neurologic findings and symptoms. SUMMARY OF BACKGROUND DATA: Thoracolumbar junction disc herniations show a variety of signs and symptoms because of the complexity of the upper and lower neurons of the spinal cord, cauda equina, and nerve roots. Furthermore, much is still unknown about thoracolumbar junction disc herniations because of their rare frequency. METHODS: The clinical features of 26 patients who had undergone operations for single disc herniations at T10-T11 through L2-L3 were investigated. Affected levels were as follows: 2 patients with disc herniation at T10-T11 disc, 4 patients at T11-T12, 3 patients at T12-L1, 6 patients at L1-L2, and 11 patients at L2-L3. The level of disc space of interest was confirmed with whole-spine plain roentgenograms. The caudal end of the cord was judged by magnetic resonance imaging and computed tomographic myelogram. RESULTS: Two patients with T10-T11 disc herniation showed moderate lower extremity weakness, increased patellar tendon reflex, and sensory disturbance of the entire lower extremities. Three of four patients with T11-T12 disc herniation experienced lower extremity weakness, and three patients had accentuated patellar tendon reflex. Sensory disturbance was observed in the anterolateral aspect of the thigh in one patient and on the entire leg in three patients. Bowel and bladder dysfunction was noted in three patients. In the T12-L1 disc herniation group (n = 3), muscle weakness and atrophy below the leg were advanced, and bowel and bladder dysfunction were also noted. Two of these three patients had bilateral drop foot, and one patient had unilateral drop foot; sensory disturbance was noted in the sole or foot and around the circumference of the anus, and the patellar tendon reflex and Achilles tendon reflex were absent. All six patients with L1-L2 disc herniation showed severe thigh pain and sensory disturbance at the anterior aspect or lateral aspect of the thigh. On the other hand, there were no clear signs of lower extremity weakness, muscle atrophy, deep tendon reflex, or bowel and bladder dysfunction in these patients. In the L2-L3 disc herniation group (n = 11), all patients had severe thigh pain and sensory disturbance of the anterior aspect or the lateral aspect of the thigh. Weakness in the quadriceps was noted in five patients and weakness in the tibialis anterior in two patients. Decreased or absence of patellar tendon reflex was observed in nine patients. Five patients had positive straight leg raising test results, and eight patients showed positive femoral nerve stretch test results. CONCLUSION: Among thoracolumbar junction disc herniations, T10-T11 and T11-T12 disc herniations were considered upper neuron disorders, T12-L1 disc herniations were considered lower neuron disorders, L1-L2 disc herniations were considered mild disorders of the cauda equina and radiculopathy, and L2-L3 disc herniations were considered radiculopathy. These findings had relatively distinct differences among herniated disc levels.

Adult↗