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Biomedical subjects

E Watanabe

Publications and source records attributed to E Watanabe.

At least 37 records · Page 2Linked to original sources
PubMed2000

Interarch tooth size relationships of 3 populations: "does Bolton's analysis apply?".

This study evaluates whether Bolton's interarch ratios extend across populations and genders. The data were derived from systematically collected preorthodontic casts of 180 patients, including 30 males and 30 females from each of 3 populations (black, Hispanic, and white). Forty-eight mesiodistal contact points were digitized on each model, and the lengths of the anterior, posterior, and overall arch segments were calculated. The results showed significant (P <.05) ethnic group differences in all 6 arch segment lengths and in all 3 interarch ratios. Whites displayed the lowest overall ratio (92.3%), followed by Hispanics (93.1%), and blacks (93.4%). The group differences were due primarily to the relationships between the posterior segments. The arch segments of males were significantly larger than females; the overall and posterior ratios were also significantly larger in males than in females. Multiple regression analyses showed that individual differences in the overall ratio were most closely associated with the size of the lower second premolar, followed by the upper lateral incisors, upper second premolars, and the lower central incisors. In combination, these 4 teeth explained approximately 50% of the variation in the overall ratio between subjects. We conclude that interarch tooth size relationships are population and gender specific. Bolton ratios apply to white females only; the ratios should not be indiscriminately applied to white males, blacks, or Hispanics.

Adolescent↗
PubMed2000

Development of an enzyme-linked immunosorbent assay for the fungicide imazalil in citrus fruits.

Imazalil has been widely used in citrus fruits such as lemons, oranges, and grapefruits. A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the detection of residual imazalil in citrus fruits. A monoclonal antibody (MoAb) generated to the synthetic imazalil hapten (EIT-0073)-protein conjugate was used. This assay was applied to lemon, orange, and grapefruit matrices for an imazalil analysis. The acceptable residue level for lemons, oranges, and grapefruits in Japan is 5 ppm. The matrix interference was minimized by direct dilution of the sample homogenate. No further cleanup was needed. The detection limit for imazalil in these citrus fruits was 0.1 ng/mL. The recovery of each fortified citrus fruit sample was >81.0%. The imazalil recovery measured by the proposed ELISA was compared to the recovery determined by a conventional HPLC. A good correlation was observed between the proposed ELISA and the HPLC. This proposed ELISA would be useful for monitoring for residual imazalil.

Antibodies, Monoclonal↗
PubMed2000

Assessment of heating effects in skin during continuous wave near infrared spectroscopy.

Near infrared spectroscopy is an increasingly important tool for the investigation of human brain function, however, to date there have been few systematic evaluations of accompanying thermal effects due to absorption. We have measured the spatial distribution of temperature changes during near infrared irradiation (789 nm) as a function of laser power, in both excised tissue (chicken meat and skin) and in the forearm of an awake human volunteer. Light was applied using a 1 mm optical fiber which is characteristic of the topographic system. The temperature of excised chicken tissue increased linearly with power level as 0.097 and 0.042 degrees C/mW at depths of 0 and 1 mm, respectively. Human forearm studies yielded temperature changes of 0.101, 0.038, and 0.030 degrees C/mW at depths of 0.5, 1.0, and 1.5 mm, respectively. Due to direct irradiation of the thermocouple all measurements represent the maximum temperature increase from the laser. In all cases the estimated heating effects from continuous wave optical topography systems were small and well below levels which would endanger tissue cells. The close similarity between ex vivo and in vivo measurements suggests negligible contributions from blood flow in the skin which was further supported by measurements during cuff ischemia. Heating effects decreased sharply with both depth and lateral position; thus, for optode spacings greater than a few millimeters, fibers can be treated independently. Finite element analysis confirms that the experimental results are consistent with a simple heat conduction model.

Animals↗
PubMed2000

Noninvasive cerebral blood volume measurement during seizures using multichannel near infrared spectroscopic topography.

Near infrared spectroscopic topography (NIRS) is widely recognized as a noninvasive method to measure the regional cerebral blood volume (rCBV) dynamics coupled with neuronal activities. We analyzed the rCBV change in the early phase of epileptic seizures in 12 consecutive patients with medically intractable epilepsy. Seizure was induced by bemegride injection. We used eight-channel NIRS in nine cases and 24 channel in three cases. In all of the cases, rCBV increased rapidly after the seizure onset on the focus side. The increased rCBV was observed for about 30-60 s. The NIRS method can be applied to monitor the rCBV change continuously during seizures. Therefore, this method may be combined with ictal SPECT as one of the most reliable noninvasive methods of focus diagnosis.

Adult↗
PubMed2000

Evaluation of absorbability of poorly water-soluble drugs: validity of the use of additives.

Apparent membrane permeation coefficients (Papp) of poorly water-soluble drugs such as indomethacin (IDM) and triamterene (TAT) were obtained by the chamber method using an isolated rat intestinal tissue after solubilization of the drugs by additives. For the additives, sodium deoxycholate (DOC), polyethylene glycol 600 (PEG 600), dimethylsulfoxide (DMSO), ethanol (EtOH), propylene glycol (PG), and rat bile were examined. Their concentrations were determined in ranges considered to be appropriate from the results of in vivo experiments and physiological findings. From the correspondence between this membrane permeability and in vivo bioavailability, we evaluated the validity of our in vitro experiment. On the basis of these evaluations, it was shown that 5% DMSO and 10% PEG 600, which did not affect the membrane integrity, were most appropriate additives for chamber experiments. Papp of IDM was greater than that of TAT, indicating that the order corresponded with that of in vivo bioavailability after oral administration of their PEG 600 solutions. Accordingly, it was concluded that Papp obtained by our in vitro system can be used to assess the in vivo bioavailability.

Absorption↗
PubMed2000

Comparison of water- and land-based exercise in the reduction of state anxiety among older adults.

This study examined the effect of an acute exercise program of different exercise conditions on state anxiety among older adults. 73 healthy subjects were recruited and randomly assigned to either water exercise group (n = 36) or land exercise group (n = 37). State anxiety was assessed before exercise and following exercise. Subjects in the water exercise performed a 70-min. exercise program consisting of a 10-min. warm-up, a 20-min. brisk walking, a 20-min. rhythmic dancing, a 10-min. resistance training, and a 10-min. cool down exercise. The land exercise program contained a 10-min. warm up and a 30-min. combined endurance and resistance exercise, followed by a 10-min. cool down exercise. Analysis showed that both exercise groups scored significantly (p<.001) lower on anxiety after exercise, but there was no significant interaction for group by trial for scores on state anxiety. The data indicate that elderly persons who participate in these types of exercise report lower state anxiety.

Aged↗
PubMed2000

[A case of non-small-cell lung cancer successfully treated using combination chemotherapy with CDDP and vinorelbine].

A 67-year-old woman presented to our hospital with a chief complaint of bloody sputum. A plain chest X-ray a CT scan revealed a tumor shadow 3 cm in size in the middle lobe of the right lung, multiple nodular shadows in the bilateral lung fields and enlarged hilar and mediastinal lymph nodes. A tumor biopsy done under bronchoscopy revealed poorly differentiated adenocarcinoma of the lungs (cT2N3M1). She was given two courses of combination therapy consisting of cisplatin (80 mg/m2) and vinorelbine (20 mg/m2). The primary tumor in the middle lobe of the right lung and the lung metastases were markedly reduced in size, and a complete response was obtained. The only adverse events were grade 4 neutropenia and grade 2 nausea and vomiting.

Aged↗
PubMed2000

Application of a channel biosensor for toxicity measurements in cultured Alexandrium tamarense.

The purpose of this study is to examine the toxicity of Alexandrium tamarense strains using a channel biosensor. With this biosensor, we were able to measure very small quantities of PSP toxin contained within an individual plankton cell. However, measurement of at least 100 cells is more desirable for increasing the sensitivity of the assay. Therefore, in the near future, the proposed biosensor system may be used for monitoring the STX (saxitoxin) produced by a few naturally toxic phytoplankton, and also measuring small amounts of toxin in shellfish.

Biological Assay↗
PubMed1999

Effect of surface contamination on adhesive bonding of cast pure titanium and Ti-6Al-4V alloy.

STATEMENT OF PROBLEM: There is little information regarding bond strengths of resin cements to cast titanium surfaces contaminated by investment material. PURPOSE: This study examined the effect of surface contamination on the shear bond strength of resin cements to cast titanium and Ti-6Al-4V alloy. MATERIAL AND METHODS: Two types of disks were cast from commercially pure titanium (CP-Ti) and Ti-6Al-4V alloy ingots using an argon-arc pressure casting unit and a phosphate-bonded Al2 O3 /LiAlSiO6 investment. After casting, disks were subjected to 3 surface treatments: (1) cast surface sandblasted (50 microm-sized Al2 O3 ) for 30 seconds; (2) metal surface sanded with silicon-carbide paper (600 grit) after grinding the contaminated cast surface (approximately 200 microm in thickness); and (3) metal surface sandblasted for 30 seconds after treatment 2. Surface structures were examined after each treatment with SEM and optical microscopy. Each type of disk was then bonded with 2 types of luting materials. Bonded specimens were subjected to thermocycling for up to 50,000 cycles, and shear bond strengths were determined after 0 (baseline) and 50,000 thermocycles. Results were statistically analyzed with 3-way ANOVA (P <.05). RESULTS: Microscopic observation of cast CP-Ti and Ti-6Al-4V exhibited noticeable structures on the cast surfaces apparently contaminated with investment material. However, there were no statistical differences (P >.05) in the bond strengths of both cements between contaminated (treatment 1) and uncontaminated surfaces (treatment 3) for both metals at baseline and after 50,000 thermocycles. The bond strength of specimens sanded with silicon-carbide paper (treatment 2) deteriorated dramatically after 50,000 thermocycles. CONCLUSIONS: Contamination of the cast metal surfaces by elements of the investment during casting did not affect bond strengths of the luting materials to CP-Ti and Ti-6Al-4V.

Alloys↗
PubMed1999

Evaluation of efficacy in platelet collection by the Haemonetics Component Collection System.

Platelet concentrate product derived from plateletpheresis from a single donor is preferable in terms of reducing the risks of adverse reactions in platelet transfusion. This study evaluated the status of platelet transfusion and the efficacy and safety of plateletpheresis machines. The average number of donors of platelet product per patient has been decreasing and recently reached nearly 1.0; however, some patients still receive multiple random donor platelet products. Platelet collection efficacy was comparable between the Haemonetics Component Collection System (CCS) and the Multi Component System (Multi). However, the CCS has been shown to be effective in terms of processed blood volume and procedure time, especially in donors with lower hematocrits. These results suggest that the CCS may be preferable and safer for donors with lower hematocrits and lighter body weights. Blood centers should collect platelets more effectively to achieve platelet transfusion with the use of platelets derived from a single donor using effective equipment.

Blood Donors↗
PubMed1999

Longitudinal post-eruptive mandibular tooth movements of males and females.

Unbiased estimates of post-eruptive eruption and migration of the mandibular teeth for large representative samples are presently unavailable. The purpose of this study was to evaluate pure tooth movements of untreated children and adolescents longitudinally. Lateral cephalograms of 214 French-Canadians, followed bi-annually between 8 and 15 years of age, were traced, and the positions of the mandibular permanent central incisors and first molars were digitized. Temporal changes in tooth position were evaluated relative to naturally stable mandibular reference structures, using the mandibular reference line for orientation. The statistical analyses included t-tests to assess gender differences and Pearson product-moment correlations to evaluate associations. The results showed that the incisors proclined significantly more for males (6 degrees) than females (3 degrees). The incisor tips displayed early mesial movements that were countered by later distal movements. The incisor apex showed a consistent pattern of distal migration between 8 and 15 years. Mandibular arch length decreased over the 7-year observation period. Rates of mesial molar migration accelerated until 11 years of age and then decelerated. There was no significant change in the mandibular occlusal plane angle between 8 and 15 years of age. Incisor eruption showed the greatest rates during adolescence, attaining peaks at approximately 12 years for females and 14 years for males. The molars erupted approximately 5 mm between 8 and 15 years of age. The greatest gender differences occurred at the older ages, with males showing greater eruption potential than females. It was concluded that the mandibular teeth show significant migration and eruption during childhood and adolescence, with gender differences in the amount, direction, and timing of movement.

Adolescent↗
PubMed1999

Enzymatic characterization of human cytosolic sulfotransferases; identification of ST1B2 as a thyroid hormone sulfotransferase.

Sulfotransferases (ST) are contained as multiple forms in human tissues with overlapping substrate specificities. To identify a form which contributes to the metabolism of 3, 3',5-triiodothyronine (T3), the functional properties of human STs were compared using recombinant STs, ST1A3, ST1A5, ST1B2, ST1E4 and ST2A3. ST1B2 showed a high affinity (Km 46.2 microM) for T3 sulfation, whereas ST1A3, ST1A5, ST1E4 and ST2A3 showed high affinities to p-nitrophenol (Km 0.4 microM), dopamine (Km 7.1 microM), beta-estradiol (Km 0.3 microM) and dehydroepiandrosterone (Km 3.3 microM), respectively. In Western blotting using antibodies raised against an individual ST, hepatic absolute amounts of these STs were determined. The content of ST1B2 in human liver correlated well with T3 sulfation activities in human liver (r=0.96). These results indicate that ST1B2 is biochemically distinct from other forms of ST, and is involved in the metabolism of T3 in human. In addition, studies of thermal stability and 2,6-dichloro-4-nitrophenol (DCNP) inhibition showed that ST1B2 was thermostable and more DCNP resistant than other forms of ST. Affinities for a co-factor, phosphoadenosine 5'-phosphosulfate, also differed 9-fold among 5 different forms of ST.

Cytosol↗
PubMed1999

Bacterial expression and functional characterization of a rat thyroid hormone sulfotransferase, ST1B1.

At least three forms of phenol sulfotransferase (ST) ST1B1, ST1A1 and ST1C1 are contained in rat livers. To identify the form contributing to the metabolism of 3,3',5-triiodothyronine (T3), functional characterization of these forms was performed by expression in Escherichia coli. ST1B1 and ST1C1 were shown to be active on sulfation towards T3 with high affinity (Km: 44.4 and 25.8 microM, respectively), whereas ST1A1 had low affinity. In Western blotting using antibodies raised against the individual ST, hepatic contents of each ST were quantitatively determined. ST1B1 showed no clear sex-difference, whereas the level of ST1C1 was higher in adult males than adult females. The content of ST1B1 was 1.4, 6.8 and 10 times higher than that of ST1C1 in adult males, adult females and both sexes of immature rats, respectively. The developmental pattern of ST1B1 was similar to that of ST1A1, but differed from that of ST1C1. These results indicate that ST1B1 and ST1C1 are involved in T3 metabolism in rats and ST1B1 is the constitutive form across sexes and ages.

Amino Acid Sequence↗
PubMed1999

Alteration of hepatic sulfation by endotoxin.

Administration of an endotoxin, lipopolysaccharide (1 mg/kg body weight), caused decreases in hepatic sulfations of xenobiotics in male rats through changes in the amounts of at least three forms of sulfotransferases, ST1A1, ST1B1 and ST1C1. The time-dependent decrease was first observed with ST1B1, followed by ST1A1 and ST1C1; and the decrease was more profound in the levels of mRNAs than those of proteins. The decreases in their mRNAs were, however, prevented by the pretreatment with dexamethasone. These results suggest that the endotoxin suppresses the hepatic sulfation through a cytokine-mediated mechanism to change individually hepatic levels of ST1A1, ST1B1 and ST1C1.

Animals↗
PubMed1998

Non-invasive assessment of language dominance with near-infrared spectroscopic mapping.

Hemispheric dominance for language is usually assessed by means of the Wada test where amobarbital is injected into the carotid artery. Recently, positron emission tomography and functional MRI have been used as non-invasive alternatives to this method. We have applied 24-channel near-infrared spectroscopic topography (NIRS) as another non-invasive method to detect the unilateral cerebral activation during a language task. We used 11 healthy volunteers and six patients with intractable epilepsy. A word-generation task was applied for 17 s, followed by an extinction/resting period of 60 s. In healthy volunteers, the inferior frontal region was activated on the side opposite to the subject's handedness in infancy. In the epilepsy cases, the activated side agreed with the dominance determined by the Wada test. Our results demonstrate that NIRS is a feasible non-invasive alternative to the Wada test.

Adult↗
PubMed1998

Neurons as well as astrocytes express proteoglycan-type protein tyrosine phosphatase zeta/RPTPbeta: analysis of mice in which the PTPzeta/RPTPbeta gene was replaced with the LacZ gene.

PTPzeta/RPTPbeta is a receptor-like protein tyrosine phosphatase expressed as a chondroitin sulfate proteoglycan. We generated mice in which the PTPzeta gene was replaced by the LacZ gene by gene targeting. Analysis of heterozygous PTPzeta-targeted mice allowed us to identify PTPzeta-producing cells during development by examining expression of the LacZ gene. LacZ expression was detected only in the central nervous system throughout development from embryonic day 8.5. In the postnatal period, subsets of neurons and astrocytes in the brain, including pyramidal cells and astrocytes in the hippocampus, expressed LacZ. Primary cultures of cells from the cerebral cortex of embryonic day 16 mice also indicated that both neurons and astrocytes were positive for LacZ. These results indicated that neurons and astrocytes express PTPzeta.

Animals↗
PubMed1998

Occurrence of a N-terminal proteolytic fragment of neurocan, not a C-terminal half, in a perineuronal net in the adult rat cerebrum.

Neurocan is a nervous tissue-unique chondroitin sulfate proteoglycan (CSPG) whose expression and proteolytic cleavage are developmentally regulated. In the adult rat brain, neurocan is completely cleaved into some proteoglycan fragments including the C-terminal half known as neurocan-C and a N-terminal fragment with a 130 kDa core glycoprotein (neurocan-130). We describe here the differential distribution of these two neurocan-derived CSPGs in the adult rat cerebrum and the occurrence of neurocan-130 as a new member of a perineuronal net-constituting molecule. At the light microscopic level, neurocan-130 exhibited pericellular localization around a subset of neurons in addition to diffuse distribution in the neuropil. In contrast, neurocan-C was distributed only diffusely in the neuropil. Double staining with anti-neurocan-130 and anti-synaptophysin antibodies suggested that neurocan-130 was localized in the vicinity of the synapses, but not at the synapses. Immunoelectron microscopy showed that neurocan-130 was mainly localized in the cytoplasm of glial cell processes, the so-called glial perineuronal net, encompassing the cell bodies of certain neurons. The presence of neurocan-130 in a limited number of glial cells may reflect some functional heterogeneity of the glia.

Age Factors↗