Biomedical subjects

T Otake

Publications and source records attributed to T Otake.

At least 19 recordsLinked to original sources

PubMed2005

Novel method of inactivation of human immunodeficiency virus type 1 by the freeze pressure generation method.

It has been reported that high-pressure (over 600 MPa) treatment at room temperature inactivates human immunodeficiency virus type 1 (HIV-1), and it has recently been shown that the high pressure generated by the expansion of water due to freezing (freeze pressure generation method, or FPGM) has an inactivating effect on bacteria and fungi. In this study, we examined the effects of treatment by FPGM on HIV-1. A sturdy vessel filled with water and securely closed with a lid was kept at 0 degrees C to -30 degrees C. High pressures of 200 MPa and 250 MPa were generated at -20 degrees C and -30 degrees C, respectively. When T-cell-tropic and macrophage-tropic laboratory strains of HIV-1 were kept at -10 degrees C, the virus infectivity decreased to approximately 1/100, and was completely lost at -20 degrees C and -30 degrees C. Four T-cell-tropic and four macrophage-tropic laboratory strains and clinical isolates of HIV-1 became completely inactivated at -30 degrees C. Treatment by FPGM at -20 degrees C to -30 degrees C reduced HIV-1 reverse transcriptase activity to approximately one tenth. In addition, treatment by FPGM at -20 degrees C was found to destroy the ability of HIV-1 to bind to CD4+ cells. In conclusion, this study showed that treatment by FPGM at -20 degrees C to -30 degrees C destroyed the infectivity of a wide range of HIV-1 strains, and suggested that the mechanisms of HIV-1 inactivation were the reduction in viral enzyme activity and the loss of the cell-binding ability of a viral envelope protein.

Cell Line, Tumor↗

PubMed2003

Mutational analysis of TGF-beta type II receptor, Smad2, Smad3, Smad4, Smad6 and Smad7 genes in colorectal cancer.

Transforming growth factor-beta(TGF-beta) is known to play an important role in controlling embryonal development, cell proliferation and homeostasis. The purpose of this study is to elucidate the involvement of the TGF-beta pathway in colorectal carcinogenesis. DNA was extracted from 100 patients with colorectal cancer. Then, all coding regions of the TGF-beta type II receptor (TRII) and the genes for Smad2, Smad3, Smad4, Smad6, and Smad7 were analyzed by PCR-SSCP and direct sequencing. Also, a LOH analysis of 18q21, where the Smad2 and Smad4 genes are located, was performed. We detected 11 cases of frameshift mutation in the TRII gene (11%) and 5 cases of point mutations in the Smad4 gene (5.0%); LOH at 18q21 was detected with 33% frequency. No abnormalities were found in the genes for Smad2, Smad3, Smad6, and Smad7. These results suggest that the abnormalities of TRII and Smad4 play an important role inhibiting TGF-beta signaling in colorectal carcinogenesis.

Base Sequence↗

PubMed2002

The role of posterior guidances under the altered anterior guidance.

In five subjects, bilateral condylar movement was assessed during lateral excursions with different tooth guidance angles without changing the intercuspal position. Statistical analysis of anova (P < 0.01) revealed that when the incisal path angle became steeper than the natural tooth guidance, distances of the non-working side condyle paths (centre of condyle) decreased significantly, while distances of the working side condyle paths (centre of condyle) remained unchanged. Directions of the working side condyle paths were random, while directions of the non-working side condyle paths remained stable. By analysing six points around the centre of the condyle, it was not possible to confirm any affect on the working side condyle movement by changing the tooth guidance angle. It was revealed that the non-working side condyle had an 'active' role during lateral excursions, and that the working side condyle moved as a result of mandibular movement that was changed because of a steepening of the incisal path angle during lateral excursions. This suggests the possibility that the working side condyle movements were affected 'passively' by altering the tooth guidance.

Adult↗

PubMed2002

A novel substance purified from Perilla frutescens Britton inhibits an early stage of HIV-1 replication without blocking viral adsorption.

Pf-gp6, a 6 kDa anti-degranulation glycoprotein purified from the extract of Perilla frutescens, was examined for its antiviral activity against HIV-1 and HIV-2 in vitro. HIV-1-induced cytopathic effect and proviral DNA synthesis were inhibited in the presence of Pf-gp6. The 50% inhibitory concentrations of Pf-gp6 for various HIV-1 strains, including clinical isolates and CCR5-using (R5) HIV-1, ranged between 1.3 and 71.0 microg/ml, depending on the combination of viral strain and host cell. Furthermore, Pf-gp6 did not directly inactivate infectious viral particles. A time-of-addition experiment revealed that Pf-gp6 lost its activity before zidovudine but after the CXCR-4 antagonist AMD3100 during the early stage of viral infection. Although the pinpoint target of Pf-gp6 remains to be elucidated, it may interfere with a step between viral entry and reverse transcription.

Adsorption↗

PubMed2001

Analysis of organic esters of plasticizer in indoor air by GC-MS and GC-FPD.

The aim of this study was to assess the performance of a method of analyzing organic esters of plasticizer in indoor air by sampling air in a charcoal tube and extracting the esters in toluene using a gas chromatography-mass spectrometer (GC-MS) and flame photometric detector (FPD). An internal standardization method was used for the GC-MS measurement of phthalate esters, whereas an external calibration method was employed to determine the levels of phosphate esters by FPD. The instrumental detection limit, the instrumental lower limit of determination, and the blank and method detection limits were also determined. Mean recoveries of phthalate esters from the charcoal tube were 97.9-115%. Mean recoveries of phosphate esters were lower but reproducible. Recoveries of the esters from indoor air were generally greater than 80%. For all the compounds, no significant breakthrough was detected up to 100 microg. Thus, indoor organic esters could be accurately determined in the range of 0.6 x 10(-3)-23 microg/m3 by the procedure presented here. Preliminary analysis of the organic esters indicated that exposure to phthalate esters via indoor air inhalation could constitute a significant contribution to total daily intake.

Air Pollution, Indoor↗

PubMed2001

Low or no antibody responses to human immunodeficiency virus type 1 Nef in infected carriers with subtype E, in contrast to subtype B that showed antibodies preferentially recognizing subtype-specific Nef epitopes.

The viral accessory gene product Nef has been shown to play an important role in human immunodeficiency virus type 1 (HIV-1)-induced pathogenesis. Only little information is available regarding the differences in the host immune responses against Nef protein and its function in vivo among different subtypes of HIV-1. In the present study, we showed marked differences in the immune responses to Nef protein between subtypes B and E. The amino acid sequence in subtype E Nef showed 72% homology with that in subtype B. Most murine monoclonal antibodies obtained by immunization with subtype B or E Nef protein showed cross-reactivity with both Nef proteins (80 and 67%, respectively). Next, we focused on the immune responses among infected Japanese and Thai individuals. Subtyping of the individuals into B and E was carried out by enzyme-linked immunosorbent assay (ELISA) using synthetic peptides corresponding to the V3 loop representing the principal neutralizing domain. Most of the sera from these individuals reacted strongly with Gag p24 proteins derived from subtypes B and E at similar levels. However, the immune responses among these individuals to Nef protein were markedly different. Some subtype B-infected Japanese and Thai individuals (40 and 35%, respectively) showed higher levels of anti-Nef antibodies, although these antibodies preferentially recognized epitopes specific to subtype B. On the other hand, most of the subtype E-infected Japanese and Thai individuals showed low or no antibody responses to Nef proteins. Thus, immune responses to Nef were markedly different between subtypes B- and E-infected carriers, suggesting different function(s) for Nef in AIDS pathogenesis. Further, vaccine design must take into account the different subtypes of HIV-1.

Acquired Immunodeficiency Syndrome↗

PubMed2001

Inhibitory effects of Korean plants on HIV-1 activities.

In the search for novel anti-human immunodeficiency virus type 1 (anti-HIV-1) agents from natural sources, 49 MeOH extracts of Korean plants were screened for their inhibitory effects against RNA-dependent DNA polymerase (RT) and ribonuclease H (RNase H) activities of HIV-1 reverse transcriptase and HIV-1 protease, and anti-HIV-1 activity. Regarding the HIV-1 reverse transcriptase, Agrimonia pilosa (whole plant), Cornus kousa (stem and leaf), Limonium tetragonum (root) and Mallotus japonicus (stem) showed significant inhibitory activity on RT activity with 50% inhibitory activity (IC(50)) of 8.9, 6.3, 7.5 and 11.9 microg/mL, respectively, whereas Agrimonia pilosa was also active against RNase H activity (IC(50) = 98.4 microg/mL). Four plants, namely Agrimonia pilosa (whole plant), Atractylodes japonica (root), Clematis heracleifolia (whole plant) and Syneilesis palmata (whole plant), were appreciably active (<35%) against recombinant HIV-1 protease at a concentration of 100 microg/mL. Crinum asiaticum var. japonicum (root) showed significant anti-HIV-1 activity (ED(50) = 12.5 microg/mL) with a favourable SI value of 16.

Anti-HIV Agents↗

PubMed2001

Effect of size of man-made and natural mineral fibers on chemiluminescent response in human monocyte-derived macrophages.

Fiber size is an important factor in the tumorigenicity of various mineral fibers and asbestos fibers in animal experiments. We examined the time course of the ability to induce lucigenin-dependent chemiluminescence (CL) from human monocyte-derived macrophages exposed to Japan Fibrous Material standard reference samples (glass wool, rock wool, micro glass fiber, two types of refractory ceramic fiber, refractory mullite fiber, potassium titanium whisker, silicon carbide whisker, titanium oxide whisker, and wollastonite). We determined how fiber length or width might modify the response of cells. We found that the patterns of time-dependent increase of CL (sigmoid type) were similar for each sample except wollastonite. We observed a strong correlation between geometric-mean length and ability to induce CL in seven samples > 6 microm in length over the time course (largest r(2) = 0.9760). Although we also observed a close positive correlation between geometric-mean width and the ability to induce CL in eight samples < 1.8 microm in width at 15 min (r(2) = 0.8760), a sample of 2.4 microm in width had a low ability to induce CL. Moreover, the relationship between width and the rate of increase in ability to induce CL had a negative correlation at 30-60 min (largest r(2) = 0.7473). Our findings suggest that the release of superoxide from macrophages occurs nonspecifically for various types of mineral fibers depending on fiber length.

Acridines↗

PubMed2000

The effect of Kana literacy acquisition on the speech segmentation unit used by Japanese young children.

Three experiments were undertaken to investigate whether young children's segmentation units would change as they learned to read kana letters, which represent morae (subsyllabic rhythmic units). The first 2 experiments used a vocal-motor segmentation task to examine whether 4- to 6-year-olds preferred to segment spoken words containing the special syllables CVN, CVQ, or CV: into syllables or into morae. The third experiment used a target monitoring task for CVN to examine whether children's detection of the target syllable in a series of words would vary depending on the moraic constitution of the target and the moraic-syllabic status of the word initial in which the target was embedded. Results indicated that the children's conscious segmentation of words, except for those having a geminate stop consonant (CVQ), developed from being a mixture of syllable- and mora-based to being predominantly mora-based as they learned to read kana letters. The tendency toward mora-based segmentation was also found in the target monitoring task, which required segmentation at a less conscious level.

Child, Preschool↗

PubMed2000

Quantitative assessment of regional myocardial blood flow using oxygen-15-labelled water and positron emission tomography: a multicentre evaluation in Japan.

Recently, a method has been proposed for the quantitative measurement of regional myocardial blood flow (MBF) using oxygen-15-labelled water and positron emission tomography (PET). A multicentre project was organized with the intention of evaluating the accuracy of this method, particularly as a multicentre clinical investigative tool. Each of seven institutions performed PET studies on more than five normal volunteers following a specified protocol. The PET study included a transmission scan, a 15O-carbon monoxide static scan and a 15O-water dynamic scan, thereby yielding MBF values which should have been independent of the spatial resolution of the PET scanner employed. Fifty-three subjects (aged 20-63 years, mean+/-SD 36+/-12 years) were studied at rest, and 31 of these subjects were also studied after dipyridamole in five institutions. Inter-institution consistency and intra-subject variation in MBF values were then evaluated. MBF averaged for all subjects was 0.93+/-0.34 ml min(-1) g(-1) at rest and 3.40+/-1.73 ml min(-1) g(-1) after the administration of dipyridamole, and the flow reserve (defined as the ratio of the two MBF values) was 3.82+/-2.12; these values are consistent with previous reports. Resting MBF values were significantly correlated with the heart rate-blood pressure product (RPP) (y=0.31+6.56E-5x, P<0.010), and RPP was in resting MBF observed in all institutions was well explained by the age-dependent RPP. No significant difference was observed in resting MBF among the institutions. Except in one institution, no significant difference was seen in dipyridamole MBF or myocardial flow reserve. No significant difference was found among the myocardial segments. Regional variation was reasonably small in five institutions, but was not acceptable in two institutions, which was attributed to the scanner performance. These observations suggest that the 15O-water PET technique is useful for a multicentre clinical study if the PET scanner can provide time-activity data with good count statistics.

Coronary Circulation↗

PubMed2000

Anti-HIV-1 phorbol esters from the seeds of Croton tiglium.

Five phorbol diesters, together with three known ones, were isolated from a MeOH extract of the seeds of Croton tiglium, and their structures were determined by spectroscopic methods and selective hydrolysis of acyl groups. These compounds were assessed for their abilities to inhibit an HIV-induced cytopathic effect (CPE) on MT-4 cells and to activate protein kinase C (PKC) associated with tumor-promoting action. 12-O-Acetylphorbol-13-decanoate and 12-O-decanoylphorbol-13-(2-methylbutyrate) effectively inhibited the cytopathic effect of HIV-1 [complete inhibitory concentration (IC100) values of 7.6 ng/ml and 7.81 microg/ml, and minimum cytotoxic concentration (CC0) value of 62.5 and 31.3 microg/ml, respectively]; however, 12-O-acetylphorbol-13-decanoate showed no activation of PKC at concentrations of 10 and 100 ng/ml. 12-O-Tetradecanoylphorbol-13-acetate (TPA) was found to be not only the most potent inhibitor of HIV-1-induced CPE (IC100 value of 0.48 ng/ml), but also the most potent activator of PKC (100% activation at 10 ng/ml).

Animals↗

PubMed2000

[Detection of genotypic and phenotypic drug-resistant HIV-1 in patients receiving antiretroviral therapy].

We have analyzed the sequences of HIV-1 reverse transcriptase and protease genes in peripheral blood mononuclear cells obtained from patients receiving antiretroviral therapy to evaluate the drug resistance-associated mutations. Of 84 HIV-1-infected individuals treated with reverse transcriptase inhibitors, 43 (51.2%) have been found to carry amino acid substitutions predicted to acquire drug-resistances. One to 3 mutations at amino acid residues reported to be associated with protease inhibitor-resistance were detected in more than 80% of protease inhibitor-naive patients. However, these pre-existing mutations did not seem to raise a real resistance after the initiation of therapy with protease inhibitors. Phenotypic resistance assay was performed with 6 clinical isolates to compare with genotypic resistance. In most of the cases, phenotype was correlated with genotypic changes, however, two strains which were isolated from patients having no experience of chemotherapy showed a decrease in susceptibility to several drugs without any resistance-related mutations detected in their genes. Taken together, determination of phenotypic resistance is necessary, especially when a newly-infected patients starts antiviral therapy.

Acquired Immunodeficiency Syndrome↗

PubMed2000

[Evaluation of antiretroviral chemotherapy based on the profile of virus isolation from HIV-1 infected individuals].

It is well-known that the biological characteristics of HIV-1 persistently infected in the host have often changed into a rapid growth in vitro, T-cell line tropism and marked syncytium inducing (SI) ability accompanied by the progress of clinical stages from AC to ARC or AIDS. We have developed a follow-up diagnostic test using the clinical markers based on the virus phenotypes mentioned above, and reported that the test was significantly useful for determining the clinical status of HIV infected individuals. Recently, highly active antiretroviral therapy (HAART) was introduced into HIV-1 chemotherapy, and has been reported to be a markedly effective treatment for HIV infected individuals. In this study, we carried out an investigation to see whether the follow-up diagnosis was useful even after introducing the HAART in Japan in 1997. The results by the laboratory diagnosis on 139 HIV infected individuals who were clinically observed over a long period showed that the positive rate of virus isolation and MT-4 cell tropism in the isolates during the two years between 1997 and 1998 were significantly lower than that of the nine years from 1988 to 1996 before the implementation of HAART. In addition, we obtained data that the effect of HAART reflects the biological profiles of virus isolation more than the CD4+ T cell counts. These results suggest that data of clinical examination using virus isolation as a parameter are useful not only for predicting the development of AIDS but also for evaluating the effects of HAART, particularly in patients showing no association between the CD4+ T cell counts and the plasma viral load.

Acquired Immunodeficiency Syndrome↗

PubMed2000

The chemiluminescent response from human monocyte-derived macrophages exposed to various mineral fibers of different sizes.

The aims of the present work were to quantify ability to induce lucigenin-dependent chemiluminescence (CL) from 6-9 day-old human monocyte-derived macrophages exposed to various mineral fibers, and to examine the relationship between ability to induce CL and fiber size. All fiber samples induced the CL response from the cells. The relationship between the number of fibers administered and the CL response was examined on all fiber samples by linear regression. The slope of the regression line supplies an approximation of the ability to induce CL. A strong increased correlation between geometric-mean length of fibers and ability to induce CL was observed for the seven fiber samples more than 6 microns in length (r = 0.9895). Geometric-mean width and the ability to induce CL showed no correlation. However, among the two fiber samples having a similar length distribution (RF2, RF3), the wider width sample (RF3, 2.4 microns) demonstrated lower ability to induce the CL than the narrower width sample (RF2, 1.1 microns). The present method enabled comparison of ability to induce lucigenin-dependent CL from human monocyte-derived macrophages for various mineral fibers with different sizes. Our findings suggested the possibility that ability to induce O2- production increased with fiber length, when fibers are longer than approximately 6 microns.

Acridines↗

PubMed1999

Breast Cancer in Two Patients with Poland's Syndrome.

Poland fs syndrome is characterized by a congenital defect of the pectoralis major associated with various types of anomalies of the ipsilateral upper extremity. Furthermore, there have been reports of Poland fs syndrome associated with malignancies such as leukemia, malignant lymphoma, and leiomyosarcoma. We describe two cases of Poland fs syndrome associated with breast cancer. The first patient developed right breast cancer associated with ipsilateral breast hypoplasia, defects of the pectoralis major and minor, and syndactyly. She underwent mastectomy and dissection of the axillary nodes. The second patient had left breast cancer associated with ipsilateral breast hypoplasia, defects of the pectoralis major and minor, and syndactyly. She underwent breast-conserving surgery and dissection of the axillary nodes without irradiation of the breast. Both patients are currently alive and free of disease. Although previously there has been no evidence that links Poland fs syndrome and breast cancer, elucidating the molecularmechanism that causes Poland fs syndrome may further clarify the relationship between Poland fs syndrome and malignancies.

Journal Article↗

PubMed1999

Inhibitory effects of Sudanese plant extracts on HIV-1 replication and HIV-1 protease.

Forty-eight methanol and aqueous extracts from Sudanese plants were screened for their inhibitory activity on viral replication. Nineteen extracts showed inhibitory effects on HIV-induced cytopathic effects (CPE) on MT-4 cells. The extracts were further screened against HIV-1 protease (PR) using an HPLC assay method. Of the tested extracts, the methanol extracts of Acacia nilotica (bark and pods), Euphorbia granulata (leaves), Maytenus senegalensis (stem-bark) and aqueous extracts of A. nilotica (pods) and M. senegalensis (stem-bark) showed considerable inhibitory effects against HIV-1 PR. Inhibitory principles were isolated from M. senegalensis and their activities were also discussed.

Anti-HIV Agents↗

PubMed1999

Sevoflurane exposure time and the neuromuscular blocking effect of vecuronium.

PURPOSE: To determine the effect of sevoflurane exposure time on the duration of vecuronium neuromuscular blockade. METHODS: In 40 adult patients anesthesia was induced with 1.5-2 mg x kg(-1) propofol and 3-5 microg x kg(-1) fentanyl and the trachea was intubated without the aid of muscle relaxant. Patients were randomized into four groups of 10. In group 1, 0.05 mg x kg(-1) vecuronium was administered with N2O and anesthesia was maintained by propofol infusion and fentanyl. Vecuronium was administered with sevoflurane 2% in 30 patients, commencing at the same time (group 2) and at 30, and 60 min after sevoflurane (groups 3, 4). Adductor pollicis force of contraction to train-of-four ulnar nerve stimulation was recorded. Times from vecuronium injection to 95%, maximal block, and recovery times to 25% recovery were recorded. RESULTS: There were no differences in times to 95% and maximal block in the four groups. Recovery times were longer in groups 3 and 4 than in groups 2 and 1 (P < 0.01). Times to 5% recovery were 15.0 +/- 3.7, 17.8 +/- 4.8, 28.2 +/- 9.9, and 29.5 +/- 9.5, and to 25% recovery were 22.3 +/- 5.2, 27.2 +/- 6.4, 42.3 +/- 16.3, and 50.5 +/- 16.4 in groups 1, 2, 3, and 4 respectively. No differences were found between group 1 and group 2 nor between group 3 and group 4. CONCLUSION: Sevoflurane produced time-dependent potentiation of vecuronium. After 30 min exposure, 25% recovery was prolonged by 89% and after 60 min by more than 100% compared with the control group.

Adult↗

PubMed1999

Primary small cell carcinoma of the esophagus with achalasia in a patient in whom pro-gastrin-releasing peptide and neuron-specific enolase levels reflected the clinical course during chemotherapy.

We report a case of primary small cell carcinoma of the esophagus in a patient with achalasia in whom pro-gastrin-releasing peptide (ProGRP) and neuron-specific enolase (NSE) levels were measured. Although chemotherapy markedly reduced the size of the primary tumor and lymph node metastases, it had no effect on liver metastases. The tumor marker levels decreased after chemotherapy as the primary tumor and lymph node metastases decreased in size, and they increased as the liver metastases enlarged. However, there was a discrepancy between the levels of ProGRP and NSE during the patient's clinical course. We demonstrate the usefulness of measuring ProGRP and NSE levels to assess the effect of chemotherapy in patients with esophageal small cell carcinoma.

Antineoplastic Combined Chemotherapy Protocols↗