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S Kojima

Publications and source records attributed to S Kojima.

At least 127 records · Page 7Linked to original sources
PubMed2000

Mitochondrial COI sequences of brachiopods: genetic code shared with protostomes and limits of utility for phylogenetic reconstruction.

A 1230-bp region of the cytochrome c oxidase subunit I (COI) gene of mitochondrial DNA of each of 16 brachiopod species, representing all five living orders, was amplified by polymerase chain reaction and sequenced. Pairwise comparisons of sequence differences plotted against divergence times estimated from the brachiopod fossil record revealed that, although there are considerable variations in the expected substitution rate among different lineages, amino acid substitutions of the COI sequences may largely become saturated in 100 Ma, due mostly to multiple substitutions at the same site. Coinciding with this result, phylogenetic analysis indicated low bootstrap values for nodes corresponding to divergence events that occurred before 100 Ma, suggesting that COI sequences are suitable only for inference of phylogenetic events subsequent to the Mesozoic. Examination of brachiopod codons corresponding to invariant amino acids in the COI of various other animals suggest the nonuniversal codon relationships UGA = Trp, AUA = Met, AAA/G = Lys, and AGA/G = Ser. These are identical to those in mollusks, annelids, and arthropods, consistent with the conclusion that brachiopods are protostomes, as indicated by previous molecular analyses.

Animals↗
PubMed2000

Passive and active recognition of one's own face.

Facial identity recognition has been studied mainly with explicit discrimination requirement and faces of social figures in previous human brain imaging studies. We performed a PET activation study with normal volunteers in facial identity recognition tasks using the subject's own face as visual stimulus. Three tasks were designed so that the activation of the visual representation of the face and the effect of sustained attention to the representation could be separately examined: a control-face recognition task (C), a passive own-face recognition task (no explicit discrimination was required) (P), and an active own-face recognition task (explicit discrimination was required) (A). Increased skin conductance responses during recognition of own face were seen in both task P and task A, suggesting the occurrence of psychophysiological changes during recognition of one's own face. The left fusiform gyrus, the right supramarginal gyrus, the left putamen, and the right hypothalamus were activated in tasks P and A compared with task C. The left fusiform gyrus and the right supramarginal gyrus are considered to be involved in the representation of one's own face. The activation in the right supramarginal gyrus may be associated with the representation of one's own face as a part of one's own body. The prefrontal cortices, the right anterior cingulate, the right presupplementary motor area, and the left insula were specifically activated during task A compared with tasks C and P, indicating that these regions may be involved in the sustained attention to the representation of one's own face.

Adult↗
PubMed2000

Effect of the consumption of ethanol on the microcirculation of the human optic nerve head in the acute phase

Purpose: The effect of the consumption of ethanol on the circulation of the optic nerve head (ONH) in the human eye in the acute phase and its mechanism were studied.Methods: Eleven volunteers drank a bottle of beer (633 mL) with or without ethanol (29.5 g). Normalized blur (NB), a quantitative index of blood flow velocity, was measured in the temporal site of the ONH. NB, blood pressure (BP) and pulse rate (PR) were measured before, immediately after, and every 15 minutes for 90 minutes after consumption. Intraocular pressure (IOP) and plasma ethanol concentration were measured before, and 30 and 90 minutes after consumption. Genotyping of the aldehyde dehydrogenase (ALDH) 2 gene was also performed.Results: NB in the ONH increased significantly from 15 to 45 minutes after consumption of ethanol and the maximum increase was 14% at 15 minutes. IOP was lowered at 90 minutes after consumption, but it was not significant. Mean BP was lowered significantly after 60 minutes. PR and ocular perfusion pressure did not change. A significant correlation was found between plasma ethanol concentration at 30 minutes and maximum NB. NB in the ALDH 2-deficient group was significantly larger from 15 to 45 minutes after consumption than in the proficient group.Conclusions: It appeared that the consumption of ethanol can increase the blood flow in the human ONH in the acute phase through decreased resistance in blood vessels induced by acetaldehyde, a metabolite of ethanol.

Journal Article↗
PubMed2000

Real-time quantitative reverse transcription-polymerase chain reaction for the detection of AML1-MTG8 fusion transcripts in t(8;21)-positive acute myelogenous leukemia.

Quantification of AML1-MTG8 fusion transcripts was performed by using real-time reverse transcription-polymerase chain reaction (RT-PCR) and the clinical value of this method was evaluated in t(8;21)-positive acute myelogenous leukemia (AML). A t(8;21)-positive cell line, Kasumi-1, was used for constructing standard curves and the corrected AML1-MTG8 mRNA expression level relative to the expression of the GAPDH housekeeping gene was calculated. Bone marrow samples from 14 patients with t(8;21)-positive AML were sequentially examined. The corrected AML1-MTG8 expression level at diagnosis varied in the range from 0.4 to 2.7 (median, 1.5) among the patients. When samples at 1, 3 and 6 months were examined after diagnosis, the corrected AML1-MTG8 expression level was found to decrease sequentially in all but one. AML1-MTG8 fusion transcripts were also detected in four of eight samples from patients in remission for more than 1 year. In conclusion, real-time RT-PCR can provide a rapid and accurate quantification of AML1-MTG8 fusion transcripts. This system could be useful to reveal the prognostic relevance of minimal residual disease in t(8;21)-positive AML.

Adolescent↗
PubMed2000

Neuron-independent Ca(2+) signaling in glial cells of snail's brain.

To directly monitor the glial activity in the CNS of the pond snail, Lymnaea stagnalis, we optically measured the electrical responses in the cerebral ganglion and median lip nerve to electrical stimulation of the distal end of the median lip nerve. Using a voltage-sensitive dye, RH155, we detected a composite depolarizing response in the cerebral ganglion, which consisted of a fast transient depolarizing response corresponding to a compound action potential and a slow depolarizing response. The slow depolarizing response was observed more clearly in an isolated median lip nerve and also detected by extracellular recording. In the median lip nerve preparation, the slow depolarizing response was suppressed by an L-type Ca(2+) channel blocker, nifedipine, and was resistant to tetrodotoxin and Na(+)-free conditions. Together with the fact that a delay from the compound action potential to the slow depolarizing response was not constant, these results suggested that the slow depolarizing response was not a postsynaptic response. Because the signals of the action potentials appeared on the saturated slow depolarizing responses during repetitive stimulation, the slow depolarizing response was suggested to originate from glial cells. The contribution of the L-type Ca(2+) current to the slow depolarizing response was confirmed by optical recording in the presence of Ba(2+) and also supported by intracellular Ca(2+) measurement. Our results suggested that electrical stimulation directly triggers glial Ca(2+) entry through L-type Ca(2+) channels, providing evidence for the generation of glial depolarization independent of neuronal activity in invertebrates.

Animals↗
PubMed2000

Interaction of alcohol and an alpha1-blocker on ambulatory blood pressure in patients with essential hypertension.

Ingestion of alcohol acutely decreases vascular resistance and blood pressure (BP) with activation of the sympathetic nervous system in Orientals. Although alpha1-blockers are widely used in the treatment of hypertension, the possible interaction between alcohol and alpha1-blockers has not been clarified. We examined the effects of prazosin on the alcohol-induced BP changes in Japanese men with mild hypertension. Ten hypertensive patients (54 +/- 3 years, mean +/- SE) were given 1 mL/kg of alcohol or isocaloric control drink with a light meal in the evening before and 5 to 7 days after treatment with prazosin (1 mg three times daily). Ambulatory BP monitoring was carried out every 30 min for 24 h in each period using Colin ABPM-630. Blood samples were obtained before and 2 h after intake of alcohol or control drink. Before prazosin treatment, alcohol ingestion decreased BP for several hours with a significant reduction in average 24-h BP, whereas it increased heart rate, plasma norepinephrine, and plasma renin activity. Treatment with prazosin caused a significant decrease in 24-h BP (136.3 +/- 4.0/82.8 +/- 2.5 v 131.6 +/- 3.2/80.0 +/- 2.3 mm Hg). The alcohol-induced hypotension at 2-4 h after ingestion was enhanced by prazosin (-18.0 +/- 3.7/-11.8 +/- 2.7 v -24.4 +/- 4.9/-17.8 +/- 2.8 mm Hg, P < .05 for diastolic BP). These results suggested that inhibition of the sympathetic nervous system with alpha1-blockers accentuates alcohol-induced hypotension. Ingestion of alcohol may cause a marked BP reduction in hypertensive Orientals treated with alpha1-blockers.

Adrenergic alpha-Antagonists↗
PubMed2000

Heterogeneity of renal cortical circulation in hypertension assessed by dynamic computed tomography.

The aim of this study was to assess the grade of heterogeneous disturbance in the renal cortical circulation using dynamic computed tomography and to investigate the relationship between the heterogeneity of renal cortical circulation and hypertension. We studied 125 patients who underwent dynamic computed tomography (CT) for various abdominal diseases and had no serious hemodynamic abnormalities. In dynamic computed tomography under appropriate conditions, each pixel (image element), less than 1 mm2, has a CT number that is in proportion to the concentration of contrast media, which reflects the blood volume in the pixel. The image was constructed at the hilus level about 50 s after the start of a continuous infusion of contrast medium. The mean and standard deviation were calculated from the CT numbers in the renal cortex. The coefficient of variation, ie, the standard deviation divided by the mean value, was used as the index of the heterogeneity of renal cortical circulation. The coefficient of variation was significantly (P < .001) greater in the hypertensive patients (n = 48, 0.174 +/- 0.006 [mean +/- SE]) than in normotensive subjects (n = 77, 0.140 +/- 0.004). The coefficient increased in parallel with the patient's age and with the grade of renal surface irregularity. In the patients whose serum creatinine levels were normal, this parameter also had a significant relationship (r = 0.367, P < .0001) with serum creatinine. These results suggest that the heterogeneity of renal cortical circulation is increased in hypertension and is also associated with aging. This parameter may become a sensitive indicator to detect slight deterioration in the renal cortical circulation.

Adult↗
PubMed2000

Usefulness of (99m)Tc-d,l-HMPAO for estimation of GSH content in tumor tissues.

To investigate whether [(99m)Tc]-hexamethyl propyleneamine oxime ([(99m)Tc]-HMPAO) is applicable for evaluating glutathione (GSH) localization in tumor, the difference of distribution between [(99m)Tc]-d,l- and meso-HMPAO was studied using a mouse tumor model. Biodistribution of [(99m)Tc]-d,l- or meso-HMPAO was studied in GSH-depleted and control Ehrlich tumor-bearing mice. GSH levels in tumors in GSH-depleted and control mice were measured in another set of mice. The uptake of [(99m)Tc]-d,l-HMPAO in tumor was significantly decreased by the diethyl maleate (DEM) treatment. On the other hand, the DEM treatment increased the accumulation of [(99m)Tc]-meso-HMPAO in tumor. Meanwhile, the content of GSH was lowest in tumor among the tissues tested and decreased in a manner similar to other tissues on preloading of DEM. [(99m)Tc]-d,l-HMPAO may be useful for estimating the GSH status in a certain tumor and thereby contribute to the diagnosis of anticancer therapy.

Animals↗
PubMed2000

Urinary schistosomiasis in southern Ghana: 1. Prevalence and morbidity assessment in three (defined) rural areas drained by the Densu river.

Epidemiological studies on urinary schistosomiasis were carried out in eight villages in the Ga and Akuapem South districts in Ghana. Single urine samples were collected from individuals aged 5 years and above between 10.00 and 14.00 h. The samples were examined for the presence of Schistosoma haematobium eggs using a filtration technique. Indirect morbidity was determined as the presence of microhaematuria and proteinuria using reagent strips, and macrohaematuria was recorded with the naked eye. Out of the study population of 3912 subjects, 2562 (65.5%) submitted urine samples. The prevalence of a Schistosoma haematobium infection ranged between 54.8 and 60.0%. Infection rates increased by age with a peak in the 10-19 years category, and decreased with increasing age. Disease prevalence was higher in males aged 15 years and above in Areas 2 (Ntoaso and Sansami Amanfro) and 3 (Dom Faase, Papase, Chento and Gidi Kope), whereas it was higher among males aged 10 years and above in Area 1 (Ayikai Doblo and Akramaman). The intensity of infection was highest among children aged 10-14 years in most of the villages. More than half of egg-positive children in this age group had a heavy infection (100 eggs and above in 10 ml of urine). Although both egg-positive and egg-negative individuals manifested variable degrees of macro- or micro-haematuria, microhaematuria was more prevalent among egg-positives (chi(2)=918.5, d.f.=1, P<0.01). The degree of microhaematuria and proteinuria were significantly associated with the intensity of the infection. These results indicate a high transmission of disease in the study area.

Adolescent↗
PubMed2000

Temperature dependence of bimolecular reactions associated with molecular mobility in lyophilized formulations.

PURPOSE: We studied the temperature dependence of acetyl transfer between aspirin and sulfadiazine, a bimolecular reaction, in lyophilized formulations at temperatures near the glass transition temperature (Tg) and NMR relaxation-based critical mobility temperature (Tmc), to further understand the effect of molecular mobility on chemical degradation rates in solid pharmaceutical formulations. The temperature dependence of the hydrolysis rates of aspirin and cephalothin in lyophilized formulations was also studied as a model of bimolecular reactions in which water is a reactant. METHODS: Degradation of lyophilized aspirin-sulfadiazine formulations containing dextran and various amounts of water at temperatures ranging from 1 degrees C to 80 degrees C was analyzed by HPLC. The degradation of cephalothin in lyophilized formulations containing dextran and methylcellulose was also analyzed at temperatures ranging from 10 degrees C to 70 degrees C. RESULTS: Acetyl transfer in lyophilized aspirin--sulfadiazine formulations containing dextran exhibited a temperature dependence with a distinct break around Tmc, which may be ascribed to a change in the translational mobility of aspirin and sulfadiazine molecules. The hydrolysis of aspirin and cephalothin in lyophilized formulations, which is also a bimolecular reaction, did not show a distinct break, suggesting that water diffusion is not rate-limiting. CONCLUSIONS: The diffusion barrier of water molecules in lyophilized formulations appears to be smaller than the activational barrier of the hydrolysis of aspirin and cephalothin based on the results of this study that the temperature dependence of the hydrolysis rate is almost linear regardless of Tmc and Tg. On the other hand, the diffusion barrier of aspirin and sulfadiazine molecules appears to be comparable to the activational barrier of the acetyl transfer reaction between these compounds, resulting in nonlinear temperature dependence.

Anti-Infective Agents↗
PubMed2000

Freeze-concentration separates proteins and polymer excipients into different amorphous phases.

PURPOSE: To study the miscibility of proteins and polymer excipients in frozen solutions and freeze-dried solids as protein formulation models. METHODS: Thermal profiles of frozen solutions and freeze-dried solids containing various proteins (lysozyme, ovalbumin, BSA), nonionic polymers (Ficoll, polyvinylpyrrolidone [PVP]), and salts were analyzed by differential scanning calorimetry (DSC). The polymer miscibility was determined from the glass transition temperature of maximally freeze-concentrated solute (Tg') and the glass transition temperature of freeze-dried solid (Tg). RESULTS: Frozen Ficoll or PVP 40k solutions showed Tg' at -22 degrees C, while protein solutions did not show an apparent Tg'. All the protein and nonionic polymer combinations (5% w/w, each) were miscible in frozen solutions and presented single Tg's that rose with increases in the protein ratio. Various salts concentration-dependently lowered the single Tg's of the proteins and Ficoll combinations maintaining the mixed amorphous phase. In contrast, some salts induced the separation of the proteins and PVP combinations into protein-rich and PVP-rich phases among ice crystals. The Tg's of these polymer combinations were jump-shifted to PVP's intrinsic Tg' at certain salt concentrations. Freeze-dried solids showed varied polymer miscibilities identical to those in frozen solutions. CONCLUSIONS: Freeze-concentration separates some combinations of proteins and nonionic polymers into different amorphous phases in a frozen solution. Controlling the polymer miscibility is important in designing protein formulations.

Calorimetry, Differential Scanning↗
PubMed2000

Solution synthesis and biological activity of human pleiotrophin, a novel heparin-binding neurotrophic factor consisting of 136 amino acid residues with five disulfide bonds.

Human pleiotrophin (hPTN), a novel heparin-binding neurotrophic factor consisting of 136 amino acid residues with five intramolecular disulfide bonds, was synthesized by solution procedure in order to demonstrate the utility of our strategy using our newly developed solvent system, a mixture of trifluoroethanol (TFE) and dichloromethane (DCM) or chloroform (CHL). The final protected peptide was synthesized by coupling two larger protected intermediates, Boc-(1-64)-OH and H-(65-136)-OBzl, in CHL/TFE (3:1; v/v) using 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) in the presence of 3,4-dihydro-3-hydroxy-4-oxo-1,2,3-benzotriazine (HOOBt). After removal of all protecting groups using the HF procedure followed by treatment with Hg(OAc)2, the fully deprotected peptide was subjected to an oxidative folding reaction. The product was confirmed as having the correct disulfide structure by examining the cystine peptides obtained by enzymatic digestions, and as possessing the same biological activities as those of the natural product. The N- and C-terminal half domains (1-64 and 65-136) were also synthesized, and measurement of their biological activities indicated that the C-terminal half domain displays almost all the activities of the full-length molecule, whereas the N-terminal half domain shows almost no activity. From these results, we were able to confirm that the C-terminal half domain is responsible for the expression of biological activities in the same manner as human midkine (hMK), another heparin-binding neurotrophic growth factor.

Amino Acid Sequence↗
PubMed2000

Successful ribavirin therapy for severe adenovirus hemorrhagic cystitis after allogeneic marrow transplant from close HLA donors rather than distant donors.

Intravenous ribavirin was given to nine patients who had developed severe adenovirus-induced hemorrhagic cystitis (AD-HC) which was resistant to conventional therapy or where there was involvement of other organs after allogeneic BMT. Three patients recovered completely from AD-HC, two of whom had been resistant to vidarabine. All three had received sibling BMTs (2 HLA matched, 1 HLA mismatched). Five patients who received BMTs from related (2 HLA mismatched) or unrelated (1 HLA matched, 2 HLA mismatched) showed an improvement in symptoms but had recurrent AD-HC after discontinuation of ribavirin. Improvement in clinical symptoms and termination of virus excretion were well correlated. The last patient who received a mismatched unrelated BMT died during ribavirin therapy. Ribavirin was notably more effective among patients receiving BMTs from siblings in contrast to patients receiving BMTs from alternative donors (<0.05). One patient experienced severe pancytopenia during the second treatment with ribavirin after HC recurrence and recovered after ceasing ribavirin. Thus, ribavirin seems to be very effective for severe AD-HC for some recipients who receive transplants from a genetically close donor. Bone Marrow Transplantation (2000) 25, 545-548.

Adenoviridae Infections↗
PubMed2000

Early intervention in post-transplant lymphoproliferative disorders based on Epstein-Barr viral load.

Using a real-time quantitative PCR assay, we identified two patients with EBV-related lymphoproliferative disorders at a very early stage. Both had received an unmanipulated bone marrow transplant with anti-thymocyte globulin for conditioning. To estimate virus-specific immunity, the frequencies of EBV-specific CD8+ T cells were measured using an enzyme-linked immunospot assay. The frequencies of EBV-specific CD8+ T cells of the two were 3.2 and 7.7%, respectively, which had possibly expanded in vivo. After withdrawing the immunosuppressive agents or administering donor lymphocytes transfusion, their symptoms regressed in parallel with the viral load.

Adult↗
PubMed2000

Monitoring four herpesviruses in unrelated cord blood transplantation.

Cord blood transplantation, which has lower risk of graft-versus-host disease than bone marrow transplantation, might have higher risk of infections. A system to quantify four herpesviruses, CMV, human herpesvirus 6 (HHV6), EBV, varicella-zoster virus using the real-time PCR assay was established and applied for prospective viral load monitoring in three recipients undergoing cord blood transplantation. CMV and HHV6 were detected in peripheral blood from all three recipients, while EBV was detected in two. Varicella-zoster virus was not detected at all. At the peak of HHV6 or CMV, each patient showed virus-related symptoms. During the pre-transplant period, CMV DNA was detected in two recipients who later developed CMV-related diseases. These observations indicate that our system is not only useful for managing herpesviruses infections in transplant recipients, but also a powerful method for clarifying the relationships between the viral load and clinical symptoms.

Adolescent↗
PubMed2000

An effective chemotherapeutic regimen for acute myeloid leukemia and myelodysplastic syndrome in children with Down's syndrome.

In recent pediatric collaborative studies of acute myeloid leukemia (AML), patients with Down's syndrome (DS) have better outcome than other patients when they were treated according to their intensive AML protocols. This may be attributed to enhanced sensitivity of DS AML cells to selected chemotherapeutic agents. We evaluated a less intensive chemotherapeutic regimen which was specifically designed for children with AML-DS. Remission induction chemotherapy consisted of daunorubicin (25 mg/m2/day for 2 days), cytosine arabinoside (100 mg/m2/day for 7 days), and etoposide (150 mg/m2/day for 3 days). Patients received one to seven courses of consolidation therapy of the same regimen. Thirty-three patients were enrolled on the study and their clinical, hematologic and immunophenotypic features were analyzed. Of the 33 patients, all were younger than 4 years and diagnosed as having acute megakaryoblastic leukemia or myelodysplastic syndrome. All patients achieved a complete remission and estimated 8 year event-free survival rate was 80+/-7%. Three patients relapsed and two died due to cardiac toxicity and one due to septic shock. The results of our study showed that patients with AML-DS constitute a unique biologic subgroup and should be treated according to a less intensive protocol designed for AML-DS.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2000

Long-term outcome of acquired aplastic anaemia in children: comparison between immunosuppressive therapy and bone marrow transplantation.

A total of 100 children under the age of 17 years with acquired aplastic anaemia (AA) were initially treated with immunosuppressive therapy (IST) (n = 63) or bone marrow transplantation (BMT) (n = 37) from an HLA-matched family donor. The projected 10-year survival rates were 55 +/- 8% and 97 +/- 3% respectively (P = 0.004). Because the IST group included 11 non-responders who were salvaged by BMT from an HLA-matched unrelated donor, we compared failure-free survival (FFS) between the groups. The probability of FFS at 10 years was 97 +/- 3% for the BMT group, compared with 40 +/- 8% for the IST group (P = 0.0001). Seven patients evolved to myelodysplastic syndrome (MDS) with monosomy 7 and the estimated cumulative incidence of MDS 10 years after diagnosis was 20 +/- 7% in the IST group. We compared the outcome of children treated with IST during the two consecutive periods of 1983-91 (group A, n = 40) and 1991-8 (group B, n = 23) to assess the impact of combined therapy with antithymocyte globulin and cyclosporin. The probability of FFS at 7 years follow-up was the same in the two groups (50 +/- 8% vs. 40 +/- 15%, P = 0.40). We recommend BMT as first-line therapy in paediatric severe AA patients with an HLA-matched family donor. Alternative donor BMT is recommended as salvage therapy in patients who relapse or do not respond to initial IST.

Adolescent↗