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Takeshi Hara

Publications and source records attributed to Takeshi Hara.

At least 19 recordsLinked to original sources
PubMed2006

Performance of monolithic silica capillary columns with increased phase ratios and small-sized domains.

Monolithic silica capillary columns for HPLC were prepared from tetramethoxysilane to have smaller sized domains and increased phase ratios as compared to previous materials, and their performance was evaluated. The monolithic silica columns possessed an external porosity of 0.65-0.76 and a total porosity of 0.92-0.95 and showed considerably higher performance and greater retention factors in a reversed-phase mode after chemical modification than columns previously reported. An octadecylsilylated monolithic silica column with the smallest domain size (through-pores of approximately 1.3 microm and silica skeletons of approximately 0.9 microm) showed a plate height of less than 5 microm at optimum linear velocities (u) of 2-3 mm/s in 80% acetonitrile for a solute having retention factors of approximately 1, and approximately 7 microm at u = 8 mm/s. With a permeability similar to that of a column packed with 5-microm particles, the monolithic silica columns were able to attain column efficiencies comparable to that of particulate columns packed with 2-2.5-microm particles, and showed performance in the "forbidden region" for the previous columns. The performance of the monolithic column can be compared favorably with that of a particle-packed column when 15,000-30,000 or more theoretical plates are desired at a pressure drop of 20-40 MPa or lower. The increased homogeneity of the co-continuous structures, in addition to the small-sized domains, contributed to the higher performance as compared to previous monolithic silica columns.

Benzene Derivatives↗
PubMed2006

Mouse epidermal keratinocytes in three-dimensional organotypic coculture with dermal fibroblasts form a stratified sheet resembling skin.

We describe an organotypic model of mouse skin consisting of a stratified sheet of epidermal keratinocytes and dermal fibroblasts within a contracted collagen gel. The model was designed to maintain the polarity of stratified keratinocytes and permit their long-term culture at an air-liquid interface. After air exposure, the thickness of the keratinocyte sheet transiently increased and then decreased to two cell layers at 2 weeks. The two-cell-layer structure is similar to that of the adult mouse epidermis. Cytokeratin 5 was localized in the lowest cell layer in the epithelial sheet, but cytokeratin 1 and loricrin were localized in the outer cell layers, resembling mouse skin. The expressions of interleukin 1alpha and 1beta in the keratinocytes and of keratinocyte growth factor 1 and 2 in the fibroblasts correlated with keratinocyte stratification. The mouse organotypic coculture is useful in studying epithelial cell-mesenchymal cell interactions in vitro.

Animals↗
PubMed2006

Automatic segmentation and recognition of anatomical lung structures from high-resolution chest CT images.

This paper describes a fully automated segmentation and recognition scheme, which is designed to recognize lung anatomical structures in the human chest by segmenting the different chest internal organ and tissue regions sequentially from high-resolution chest CT images. A sequential region-splitting process is used to segment lungs, airway of bronchus, lung lobes and fissures based on the anatomical structures and statistical intensity distributions in CT images. The performance of our scheme is evaluated by segmenting lung structures from high-resolution multi-slice chest CT images from 44 patients; the validity of our method was proved by preliminary experimental results.

Humans↗
PubMed2006

Serum-soluble tumor necrosis factor receptor 2 (sTNF-R2) level determines clinical outcome in patients with aggressive non-Hodgkin's lymphoma.

BACKGROUND: Recently investigators have worked to identify prognostic factors in non-Hodgkin's lymphoma (NHL) so an appropriate therapeutic plan can be put in action. The aim of the present study was to assess the prognostic significance of serum soluble tumor necrosis factor receptor (sTNF-R) 2 in aggressive NHL. METHODS: One hundred and ten consecutive patients with aggressive NHL who were previously untreated (diffuse large B-cell lymphoma; 94, peripheral T-cell lymphoma; 16) were prospectively enrolled in this study between 1997 and 2002. The patients were treated with 6-8 cycles of CHOP or THP-COP regimens. RESULTS: High serum sTNF-Rs level was associated with some poor prognostic factors and low complete remission rate. Patients with high sTNF-R1 (4 ng/mL and over) and sTNF-R2 (15 ng/mL and over) at onset had significantly lower survival rates (5 yr: 19%, 19%) than those with low sTNF-R1 (under 4 ng/mL) and sTNF-R2 (under 15 ng/mL) (62% and 69%), respectively (P < 0.0005 and 0.0001). Multivariate analysis employing sTNF-R2 and some conventional prognostic factors demonstrated that a combination of sTNF-R2 and performance status, and that of sTNF-R2, sIL-2R, and LDH were significant prognostic factors for poor overall survival and for poor event-free survival, respectively. In addition, we attempted to use sTNF-R2 in combination with the international prognostic index (IPI). The patients in the high risk group and those with high sTNF-R2 in the low-intermediate (LI)/high-intermediate (HI) risk group had significantly lower survival rates than the patients in the low risk group and those with low sTNF-R2 in LI/HI risk group (P < 0.0001). CONCLUSIONS: The results suggest that a high serum sTNF-R2 level predicts a poor prognosis in aggressive NHL and may be a useful biomarker for selecting appropriate treatment when used in combination with the IPI.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2006

Improved endcapping method of monolithic silica columns.

Following a bonding reaction with octadecyldimethyl-N,N-diethylaminosilane (ODS-DEA), a monolithic silica was subjected to consequential on-line endcapping reactions with hexamethyldisilazane (HMDS) or N-(trimethylsilyl)imidazole (TMSI) to compare the two reagents. Endcapping of monolithic silica C(18) columns prepared by a manufacturer was also studied. After endcapping with TMSI in acetonitrile (ACN), all columns provided better performance for hydrogen-bonding compounds and basic compounds than C(18) phases endcapped with HMDS. TMSI endcapping of commercial Chromolith Performance columns also gave improved performance. The results indicate that one can significantly improve the performance of monolithic silica C(18) columns for basic compounds by a simple on-column reaction with TMSI in ACN at a relative low temperature.

Amphetamine↗
PubMed2006

Fas and Fas ligand expression on germinal center type-diffuse large B-cell lymphoma is associated with the clinical outcome.

In recent years, diffuse large B-cell lymphoma (DLBCL) has been classified by DNA microarray analysis into the germinal center B-cell-like (GC) type, the activated B-cell-like (ABC) type and type 3. The latter two types can be collectively categorized as the non-GC (NGC) type. From the prognostic perspective, the GC type has a favorable clinical outcome when compared with the NGC type. The protein Fas induces apoptosis of lymphocytes by binding with the Fas ligand (FasL), and escape from such apoptosis is considered to lead to malignant transformation of the cells and unrestricted growth of lymphoma. We proposed a hypothesis that Fas/FasL expression could be possibly related with a better survival of GC type DLBCL and evaluated 69 DLBCL cases immunohistochemically with CD10, Bcl-6, MUM1, Fas and FasL. These lymphomas were classified as GC type (positive for CD10 or Bcl-6 and negative for MUM1) or NGC type. The GC type had a better overall survival rate than the NGC type (P = 0.0723). Among markers as given above, positive CD10 was the most significant prognostic factor for overall survival in total DLBCL (P < 0.05). In the GC type, Fas and FasL expressions were significantly associated with a favorable overall survival (Fas: P < 0.005; FasL: P < 0.05). Hence, Fas or FasL expression might contribute to a better prognosis of this type of DLBCL.

Adult↗
PubMed2006

Increase of peak intraocular pressure during sleep in reproduced diurnal changes by posture.

OBJECTIVE: To characterize diurnal intraocular pressure (IOP) changes in primary open-angle glaucoma by reproducing IOPs based on patient posture. METHODS: In 148 patients with untreated primary open-angle glaucoma who had IOPs recorded during clinic hours that were less than 21 mm Hg (average, 14.8 +/- 3.2 mm Hg), we measured IOP by noncontact tonometry every 2 hours from 6 am to midnight and every 3 hours from midnight to 6 am with patients sitting and supine. The IOP was reproduced by designating the sitting IOP as measurements taken when the patient was awake and the supine IOP as measurements taken when the patient was asleep for each individual. The reproduced diurnal IOP was composed of 12 measurements that included 2 to 4 IOP levels measured with the patients supine and the rest while they were sitting. RESULTS: The peak of sitting diurnal IOP (mean +/- SD) for 148 patients was 16.0 +/- 2.7 mm Hg, which was significantly lower than the peak of supine IOP (18.9 +/- 3.9 mm Hg) or the reproduced IOP (17.5 +/- 3.6 mm Hg) (P<.001 for both comparisons). The average reproduced IOP at each measurement time peaked at 3 am during sleep; with sitting diurnal IOP or supine diurnal IOP, the peak IOPs were at noon. Twenty-nine patients (20%) with an IOP less than 21 mm Hg during clinic hours had a reproduced IOP of 21 mm Hg or greater while asleep, compared with only 5 patients (3%) when the patients were sitting only. CONCLUSIONS: In patients with primary open-angle glaucoma and IOPs less than 21 mm Hg during clinic hours, 20% of patients had a reproduced IOP of 21 mm Hg or greater, compared with only 3% who had an IOP of 21 mm Hg or greater while sitting. Intraocular pressures peaked in most patients during sleep.

Adolescent↗
PubMed2006

Dugong (Dugong dugon) vocalization patterns recorded by automatic underwater sound monitoring systems.

To quantitatively examine the diurnal, or tidal, effects on dugong behavior, we employed passive acoustic observation techniques to monitor the animals. Automatic underwater sound monitoring systems for dugongs (AUSOMS-D) were deployed on the sea floor at depths of about 5 m south of Talibong Island, Thailand. The AUSOMS-D recorded underwater sound in stereo at a sampling frequency of 44.1 kHz for more than 116 consecutive hours. Dugong calls were automatically detected by newly developed software with a detection rate of 36.1% and a false alarm rate of 2.9%. In total, 3453 calls were detected during the 164 h of recording. The autocorrelation of the call rate indicated an attendance cycle of about 24 or 25 h, and the most frequent vocalizations were observed from 0300 to 0500 h. The calculated bearings of the sound sources, i.e., dugongs, were used as an indicator to track the relative numbers of dugongs during the monitoring periods.

Animals↗
PubMed2006

Feeding behavior of wild dugongs monitored by a passive acoustical method.

Little is known about feeding behavior of wild dugongs (Dugong dugon) because direct measurements of feeding events in the water were scarcely feasible. In this study, the authors achieved the first successful feeding sound monitoring in a seagrass area using a full-band underwater recording system (called automatic underwater sound monitoring system for dugong: AUSOMS-D). In total, 175 feeding sounds were identified in 205 h of recording. Feeding sounds were only detected at night, implying diurnal differences in the feeding behavior of the studied dugong population. Differences in periodicity of feeding sounds suggested that two or more individuals were in the acoustically observable area. Furthermore, a feeding position monitored by two AUSOMS-Ds was used to calculate source levels of dugong feeding sounds. Assuming spherical_propagation, source levels were measured between 70.6 and 79.0 dB rms re 1 microPa/square root of Hz.

Acoustics↗
PubMed2006

Properties of monolithic silica columns for HPLC.

Monolithic silica columns and their use in high peak-capacity HPLC separations are reviewed. Monolithic silica columns can potentially provide higher overall performance than particle-packed columns based on the variable external porosity and variable through-pore size/skeleton size ratios. The high permeability of monolithic silica columns resulting from the high porosity is shown to be advantageous to generate large numbers of theoretical plates with long capillary columns. High permeability together with the high stability of the network structures of silica allows their use in high-speed separations required for a second-dimension column in two dimensional HPLC. Disadvantages of monolithic silica columns are also described.

Benzene Derivatives↗
PubMed2006

[Adverse reaction after use of latanoprost in Japanese glaucoma patients].

PURPOSE: Although latanoprost has proven to have a strong hypotensive effect, some patients show adverse reactions such as eyelid pigmentation, iridial pigmentation, or hypertrichosis. We prospectively investigated these adverse reactions. SUBJECTS AND METHODS: One hundred and one Japanese glaucoma or ocular hypertension patients were included. Iridial, eyelid, and eyelash photographs were taken before and at 6 months after latanoprost treatment. Increased eyelid pigmentation, iridial pigmentation, eyelash pigmentation, vellus hair of the lid, and hypertrichosis were assessed from these photographs. The correlation between the incidence of these adverse reactions and the time of instillation, type of glaucoma, sex, age, or concomitantly used eye drops, and the overlap of these were evaluated. RESULTS: Increased pigmentation of the eyelid was found in 6 cases(5.9%), of the iris in 32 cases (31.7%), of the eyelashes in 29 cases (28.7%), vellus hair of the lid in 38 cases(37.6%), and hypertrichosis in 51 cases(50.5%). Pigmentation of the eyelid was more frequently observed in patients who used latanoprost concomitantly (16.7%) than in those who did not use anti-glaucomatous eye drops before latanoprost treatment (1.6%), or in those treated with latanoprost who had switched from other anti-glaucomatous eye drops (6.3%) (p= 0.03). CONCLUSIONS: The incidence of adverse reactions caused by latanoprost was higher in the eyelashes and iris than in the eyelid.

Adolescent↗
PubMed2006

[Plasmapheresis for fulminant autoimmune hemolytic anemia with rapidly progressing disturbance of consciousness].

A 64-year-old male was diagnosed as having autoimmune hemolytic anemia (AIHA) in December 2001. The diagnosis of AIHA was established based on the presence of anemia, hyperbilirubinemia, reticulocytosis, positive Coombs test and serum LDH elevation. Although he received steroid pulse therapy, disturbance of consciousness appeared and the anemia and icterus did not improve. Plasma exchange was carried out to eliminate antibodies as an emergency measure. The patient's symptoms were ameliorated following four courses of plasma exchange. This case represents a case of aggressive AIHA with disturbance of consciousness and refractory to conventional corticosteroid therapy. Plasma exchange rapidly led to complete remission.

Anemia, Hemolytic, Autoimmune↗
PubMed2006

[Two cases of food-dependent exercise-induced anaphylaxis difficult to evoke symptoms by provocation test].

We report two cases of food-dependent exercise-induced anaphylaxis (FDEIA), which were hardly induced by provocation test in the hospital. Case 1: A 28-years-old Japanese female suffers repeated episodes of sternutation, nasal discharge and edema of eyelids after wheat ingestion of wheat followed by exercise. Case 2: A 14-years-old Japanese male suffers repeated episodes of wheal formation on whole body and dyspnea after lunch containing apple followed by exercise. Both of them had never developed symptoms by either ingestion or exercise alone. Provocation tests were performed on admission by combinations of the ingestion of suspected foods, exercise, and aspirin, but no symptoms were reproduced by any combination of them. After discharge, case 1 reproduced symptoms during exercise after the ingestion of wheat under prostration and cold climate. Case 2 reproduced symptoms during exercise after ingestion of apple when he suffered from common cold. Warm and comfortable condition in admission may make it harder to evoke symptoms by the provocation test. Frigidity, cold, prostration, and stress should be reckoned with in the provocation test to improve the accuracy of diagnosis for FDEIA.

Adolescent↗
PubMed2005

Two-dimensional reversed-phase liquid chromatography using two monolithic silica C18 columns and different mobile phase modifiers in the two dimensions.

Comprehensive two-dimensional (2D) HPLC in the reversed-phase liquid chromatography (RPLC) mode using C18 silica monolith columns at first dimension (1st-D) (10 cm x 4.6mm I.D.) and second dimension (2nd-D) (5 cm x 4.6mm I.D.) was carried out successfully. A mixture of water and tetrahydrofuran (THF) was used as a mobile phase in the 1st-D separation, and a mixture of water and methanol (CH3OH) in the 2nd-D separation. Sample fractions from 1st-D column were directly loaded into an injection loop of the 2nd-D HPLC equipped with two injector valves for one column. The fractionation time at the 1st-D that was equal to the separation time at the 2nd-D was 45 or 60s. Total peak capacity up to 900 was obtained in about 60 min for the isocratic mode separation of aromatic compounds in this system. Gradient elution mode applied to both 1st-D and 2nd-D separations resulted in shorter separation time and better separation efficiencies than the isocratic mode. It was demonstrated that 2D-HPLC systems employing popular C18 stationary phases with different organic modifiers in mobile phases for each dimension could produce large peak capacity. The different selectivities were provided by the difference in polar interactions between a solute and the organic modifier existing in the stationary phase.

Chromatography, High Pressure Liquid↗
PubMed2005

Deficiency of protein kinase Calpha in mice results in impairment of epidermal hyperplasia and enhancement of tumor formation in two-stage skin carcinogenesis.

We generated a mouse strain lacking protein kinase Calpha (PKCalpha) and evaluated the significance of the enzyme in epithelial hyperplasia and tumor formation. PKCalpha-deficient mice exhibited increased susceptibility to tumor formation in two-stage skin carcinogenesis by single application of 7,12-dimethylbenz(a)anthracene (DMBA) for tumor initiation and repeated applications of 12-O-tetradecanoylphorbol-13-acetate (TPA) for tumor promotion. Tumor formation was not enhanced by DMBA or TPA treatment alone, suggesting that PKCalpha suppresses tumor promotion. However, the severity of epidermal hyperplasia induced by topical TPA treatment was markedly reduced. In mutant mice, the number of 5-bromo-2'-deoxyuridine-labeled epidermal basal keratinocytes increased 16 to 24 hours after topical TPA treatment as in the case of wild-type mice, but significantly decreased at 36 and 48 hours. Furthermore, the regenerating epithelium induced by skin wound significantly decreased in thickness but was not structurally impaired. The enhanced tumor formation may not be associated with epidermal hyperplasia. The induction levels of epidermal growth factor (EGF) receptor ligands, tumor growth factor alpha (TGF-alpha), and heparin-binding EGF-like growth factor, in the skin of mutant mice by TPA treatment were significantly lower than those in the skin of wild-type mice. PKCalpha may regulate the supply of these EGF receptor ligands in basal keratinocytes, resulting in a reduced epidermal hyperplasia severity in the mutant mice. We propose that PKCalpha positively regulates epidermal hyperplasia but negatively regulates tumor formation in two-stage skin carcinogenesis.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2005

Evaluation of osteoporosis in X-ray CT examination: a preliminary study for an automatic recognition algorithm for the central part of a vertebral body using abdominal X-ray CT images.

We have developed an algorithm that can distinguish the central part of the vertebral body from abdominal X-ray CT images to determine whether it is possible to aid a diagnosis of osteoporosis. We classified three measures for the principal component analysis and linear discriminant function. When we judged whether patients had osteoporosis or not, the ratio usable for diagnosing osteoporosis (sensitivity) was 1.00 (15/15), and for diagnosing as normal (specificity) was 0.64 (7/11). We believe that this algorithm can be used to aid in diagnosing osteoporosis, utilizing the measures obtained from the CT images.

Adult↗