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S Okamoto

Publications and source records attributed to S Okamoto.

At least 55 records · Page 3Linked to original sources
PubMed2003

No clear-cut evidence for cadmium-induced renal tubular dysfunction among over 10,000 women in the Japanese general population: a nationwide large-scale survey.

OBJECTIVE: To examine whether environmental exposure to cadmium has been inducing kidney dysfunction among middle-aged women in the general population in Japan. METHODS: This study was conducted in 2000 and 2001. Morning spot urine samples were collected from 10,753 women (mostly aged 35 to 60 years) in ten prefectures all over Japan (thus about 1,000 women per site). Urine samples were analyzed for cadmium (Cd-U), calcium (Ca-U), magnesium (Mg-U), zinc (Zn-U), alpha(1)- and beta(2)-microglobulins (alpha(1)- and beta(2)-MG-U). The urinary analyte concentrations were corrected for creatinine (cr) concentration (i.e., Ucr). The data thus obtained were subjected to statistical evaluation by chi-square test, ANOVA, multiple comparison test, and simple regression analysis (SRA) as well as multiple regression analysis (MRA) including logistic regression analysis (LRA). Log-normal distribution was assumed for Cd-Ucr, alpha(1)-MG-Ucr and beta(2)-MG-Ucr, whereas normal distribution was considered for age, Ca-Ucr, Mg-Ucr and Zn-Ucr. RESULTS: Geometric mean values (GM) of Cd-Ucr were distributed unevenly, depending on the sampling areas, with a grand GM of 1.3 microg/g cr, the highest (3.2 microg/g cr) and lowest GM values(0.8 microg/g cr) being significantly different from GMs of other areas. Correlation matrix analysis with subjects of all ages showed that log alpha(1)-MG-Ucr and log beta(2)-MG-Ucr correlated significantly (r=0.272 and 0.202, respectively) with log Cd-Ucr, but they correlated also with age (r=0.280 and 0.213, respectively). The same analysis with the two selected age groups (41-50 and 51-60 years), however, failed to show close correlation of alpha(1)-MG-Ucr and log beta(2)-MG-Ucr with Cd-Ucr. Both MRA and LRA indicated that age was a confounding factor in the evaluation of the effect of Cd-U on the two MG levels. Whereas the LRA with the all-age group showed a positive influence of log Cd-Ucr on log alpha(1)-MG-Ucr and log beta(2)-MG-Ucr, such effect disappeared in parallel with the disappearance of age effects when LRA was conducted with the two selected age groups. An exceptional observation was the influence of log Cd-Ucr on log alpha(1)-MG-Ucr (but not on log beta(2)-MG-Ucr) in LRA when a cut-off value of 5.00 mg for alpha(1)-MG-U/g cr was applied. Comparison between the low and high Cd-U groups showed that both alpha(1)-MG-Ucr and beta(2)-MG-Ucr were higher in the high Cd-U groups, but prevalence of cases with alpha(1)-MG-Ucr and beta(2)-MG-Ucr in excess of the cut-off values did not differ between the two groups except when a cut-off value of 5.00 mg/g cr was employed for alpha(1)-MG-U. CONCLUSIONS: In over-all evaluation, no clear-cut evidence was obtained in the present study to show that environmental exposure to Cd has induced tubule dysfunction among middle-aged women in the general population in Japan. It might be the case, however, that an increase in alpha(1)-MG-U was associated with Cd exposure. In this sense, it is apparently desirable from public health viewpoints to make further efforts to reduce the intensity of the general population's exposure to environmental Cd.

Adult↗
PubMed2003

Threshold levels of urinary cadmium in relation to increases in urinary beta2-microglobulin among general Japanese populations.

Through literature survey, paired data on cadmium (Cd) and beta(2)-microglobulin (beta(2)-MG) levels (as corrected for creatinine concentration) in urine (i.e., Cd-Ucr and beta(2)-MG-Ucr) among Japanese populations were available for 32 groups of men and 58 groups of women in 12 publications. Plotting of the Cd-Ucr and beta(2)-MG-Ucr data for the groups of women showed that beta(2)-MG-Ucr stayed unchanged when Cd-Ucr was at lower levels, whereas beta(2)-MG-Ucr increased sharply when Cd-Ucr was in excess of 10-20 microg/g cr. Regression analysis was made for groups of women with no elevation in beta(2)-MG-Ucr, and those with >400 or >1000 microg beta(2)-MG-U/g cr. A threshold Cd-Ucr level in relation to an increase in beta(2)-MG-Ucr was estimated as Cd-Ucr at the point of intercept of the two regression lines, one with no beta(2)-MG-Ucr elevation, and the other with >400 or >1000 microg beta(2)-MG-U/g cr. Cd-Ucr at the point of flexion thus calculated was 11-12 microg/g cr. Such observation was quantitatively reproduced by the analysis of data for men, giving 10-11 microg Cd-U/g cr at the point of flexion. This study suggests that the relationship of beta(2)-MG-Ucr with Cd-Ucr is not linear but in the shape of letter 'J', i.e., beta(2)-MG-Ucr increases sharply when Cd-Ucr is in excess of 10-12 microg/g cr.

Adult↗
PubMed2003

Granulocyte transfusion as a treatment for enterococcal meningoencephalitis after allogeneic bone marrow transplantation from an unrelated donor.

Bacterial meningoencephalitis occurring in the pre-engraftment period after bone marrow transplantation (BMT) is a rare complication, and the feasibility of granulocyte transfusion (GTX) in such cases remains to be elucidated. A 37-year-old man developed enterococcal meningoencephalitis during a severely granulocytopenic pre-engraftment period after BMT. Despite therapy with appropriate antibiotics, cultures of blood and cerebro-spinal fluid (CSF) continued to grow Enterococcus faecalis, and he developed rapid mental deterioration and seizure. Granulocytes were collected from his HLA-mismatched, ABO-matched sibling with subcutaneous injection of granulocyte colony-stimulating factor (G-CSF) and oral dexamethazone. Transfusion of 4.4 x 10(10) granulocytes resulted in a 12-h post-transfusion granulocyte increment of 2.0 x 10(9)/l, and maintained peripheral blood granulocyte counts above 0.5 x 10(9)/l for 3 days. A rapid increase of granulocytes in CSF was also observed, and cultures of blood and CSF became negative after GTX. A transient worsening of seizure was observed as a potential side effect of GTX. The patient subsequently developed septic shock because of Pseudomonas aeruginosa and died. Further studies are warranted to evaluate the clinical efficacy of GTX for the treatment of uncontrolled infections in granulocytopenic stem cell transplant recipients.

Adult↗
PubMed2003

Autologous serum eye drops for the treatment of severe dry eye in patients with chronic graft-versus-host disease.

We investigated the efficacy and safety of autologous serum eye drops for the treatment of severe dry eye after allogeneic haematopoietic stem cell transplantation (SCT). A total of 14 patients (four males and 10 females; median age, 31.0 years) with severe dry eye associated with chronic graft-versus-host disease (cGVHD) were enrolled in this study. All patients were refractory to treatment with conventional artificial tears. Autologous serum eye drops, a solution made of 20% autologous serum in sterile saline, were applied 10 times per eye per day. The patients were evaluated every 4 weeks according to visual acuity, corneal sensitivity, vital staining of the ocular surface, tear dynamics, and subjective assessments of symptoms (complaints scores). The median follow-up period was 19.4 months (range: 4-41 months). After 4 weeks of treatment, significant improvement was observed in both complaint scores (from 33.7+/-12.3 to 23.6+/-10.6 points; P<0.01) and fluorescein scores (from 5.8+/-2.0 to 2.4+/-0.9 points; P<0.005). Significant improvements were observed also in rose-bengal staining and tear break-up time. In seven of the 14 patients, the responses were maintained for 6-41 months (median:19.4+/-8.3 months), while six of the other seven patients required treatment with punctal plugs in addition to autologous serum eye drops. One of these other seven patients developed eczema around the eyelids, after which the treatment was discontinued. No serious adverse events were observed. We conclude that autologous serum eye drops are safe and effective for treating severe dry eye associated with cGVHD and that more efficient control of dry eye may be achieved by the combined use of autologous serum eye drops with punctal plugs.

Adult↗
PubMed2003

Hand-assisted laparoscopic splenectomy for a huge splenic cyst: operative technique and case report.

We report the case of a huge splenic cyst that was successfully treated by hand-assisted laparoscopic splenectomy. A 17-year-old girl with a chief complaint of left-sided abdominal pain was admitted to our department for investigation of a splenic tumor. Ultrasonography, computed tomography, and magnetic resonance imaging revealed a huge cystic lesion in the spleen measuring approximately 10 cm in diameter. Hand-assisted laparoscopic splenectomy was safely performed to diagnose and treat the splenic tumor. The histologic diagnosis was an epithelial cyst of the spleen with no atypical cells in the cyst wall. Hand-assisted laparoscopic splenectomy may be a good method of managing a huge splenic cyst that becomes symptomatic and potentially life-threatening through enlargement, rupture, and secondary infection.

Adolescent↗
PubMed2002

Analysis for threshold levels of cadmium in urine that induce tubular dysfunction among women in non-polluted areas in Japan.

OBJECTIVE: To examine if there is a threshold in urinary cadmium concentration that induces elevation in urinary microglobulins. METHODS: The database developed in a previous field survey (Ezaki et al. 2002) was employed. In the survey conducted in 2000 and 2001, more than 10,000 middle-aged women (with no occupational exposure to Cd) in ten prefectures all over Japan gave morning spot urine samples, which were analyzed for cadmium (Cd-U), calcium (Ca-U), magnesium (Mg-U), zinc (Zn-U), alpha(1)- and beta(2)-microglobulins (alpha(1)- and beta(2)-MG-U), and creatinine (cr). The urinary analyte concentrations were corrected for cr concentration (to be expressed as, e.g., Cd-Ucr), and the data thus obtained were subjected to statistical evaluation. The largest geometric mean (GM) for Cd-Ucr among the ten prefecture was 3.2 microg Cd/g cr, and the maximum Cd-Ucr observed among the women studied was 20.9 microg Cd/g cr. RESULTS: Both alpha(1)-MG-Ucr and beta(2)-MG-Ucr increased as a function of the increase in Cd-Ucr among all the women and also in sub-populations of narrow age ranges (i.e., 41-50 and 51-60 years), with no apparent threshold Cd-Ucr. Comparison of the cases exceeding cut-off alpha(1)-MG-Ucr and beta(2)-MG-Ucr levels also indicated a Cd dose-dependent increase in the prevalence, similarly without a threshold Cd-Ucr. In addition, such findings were essentially reproducible when elevation in alpha(1)-MG-Ucr and beta(2)-MG-Ucr levels was examined with the three essential elements, especially with Ca-Ucr and Mg-Ucr, although less clearly with Zn-Ucr. The observations as a whole suggest a possibility that the dose-dependent increases in alpha(1)-MG-Ucr and beta(2)-MG-Ucr with no apparent threshold for element concentration is not specific to Cd-Ucr but common to other elements. CONCLUSIONS: No threshold Cd-Ucr was detected in relation to the increases in alpha(1)-MG-Ucr and beta(2)-MG-Ucr. The element dose-dependent increases in the two MGs with no threshold in the element concentration might be not limited to Cd, but common to other elements. Further studies are apparently necessary.

Adult↗
PubMed2002

Magnetic order and dynamics in an orbitally degenerate ferromagnetic insulator.

Neutron scattering was used to determine the spin structure and the magnon spectrum of the Mott-Hubbard insulator YTiO3. The magnetic structure is complex, comprising substantial G-type and A-type antiferromagnetic components in addition to the predominant ferromagnetic component. The magnon spectrum, on the other hand, is gapless and nearly isotropic. We show that these findings are inconsistent with the orbitally ordered states thus far proposed for YTiO3 and discuss general implications for a theoretical description of exchange interactions in orbitally degenerate systems.

Journal Article↗
PubMed2002

Endosonographic diagnosis of pneumatosis cystoides intestinalis in infancy.

We report pneumatosis cystoides intestinalis in a 10-month-old girl who developed bloody diarrhea following chemotherapy for leukemia. The diagnosis was made only by colonic endoscopic ultrasonography, whereas the abdominal plain radiogram and computed tomography failed to elucidate the diagnosis. She was successfully treated with hyperbaric oxygen therapy. Wider application of endoscopic ultrasonography may lead to the more frequent detection of pneumatosis cystoides intestinalis, currently a rare disorder.

Endosonography↗
PubMed2002

Dose-adjusted preemptive therapy for cytomegalovirus disease based on real-time polymerase chain reaction after allogeneic hematopoietic stem cell transplantation.

We have prospectively evaluated the efficacy of real-time PCR-guided preemptive therapy for CMV diseases in allogeneic hematopoietic stem cell transplant recipients with grades II-IV acute GVHD. The dose of ganciclovir was adjusted according to the viral load determined by real-time polymerase chain reaction (PCR). On detecting CMV reactivation in the plasma, ganciclovir was initiated at a dose of 5 mg/kg body weight once daily, and the dose was increased to twice daily if viral load continued to increase after initiating ganciclovir. In 39 evaluable patients, CMV reactivation assessed by real-time PCR became positive in 30 (77%). One developed CMV gastroenteritis before PCR became positive. Thus the remaining 29 patients were treated preemptively with ganciclovir. The dose of ganciclovir was increased in 12 patients (41%) of preemptively treated patients for increasing viral load. CMV diseases were diagnosed in two patients (one gastroenteritis and one retinitis), and late CMV disease was diagnosed in one patient (gastritis). The treatment was generally well-tolerated, but three patients (10%) developed neutropenia (neutrophil count less than 1.0 x 10(9)/l). In conclusion, real-time PCR-guided preemptive therapy with decreased dose of ganciclovir is feasible and does not increase the frequency of CMV diseases if the dose is adjusted according to the viral load.

Adult↗
PubMed2002

Recurrent acute myositis after allogeneic bone marrow transplantation for myelodysplasia.

A 54-year-old woman developed polymyositis 6 months after allogeneic bone marrow transplantation (BMT) for acute myelogenous leukemia transformed from myelodysplasia. At the onset of myositis, the patient had oral dryness, and the histology of oral mucosa was compatible with chronic graft-versus-host disease (GVHD). Muscle biopsy revealed focal muscle necrosis with massive lymphocytic infiltration. She was diagnosed with polymyositis, and the dose of cyclosporine was increased. Three months later, a complete resolution of myositis had been obtained, and the cyclosporine was tapered off. However, 51 months after the first episode of myositis, she again noted severe myalgia and was diagnosed with a recurrence of polymyositis based on high serum creatinine kinase (CK) and the findings of magnetic resonance imaging (MRI). At that time, chronic GVHD in other organs was not present. She achieved a second remission of polymyositis with cyclosporine, and has remained in remission for 4 years. The pathogenesis of myositis can be attributed to the immunologic imbalance characteristic of the post-allogeneic BMT setting.

Bone Marrow Transplantation↗
PubMed2001

Characterization of genes encoding multi-domain proteins in the genome of the filamentous nitrogen-fixing Cyanobacterium anabaena sp. strain PCC 7120.

Computational analysis of gene structures in the genome of Anabaena sp. PCC 7120 revealed the presence of a large number of genes encoding proteins with multiple functional domains. This was most evident in the genes for signal transduction pathway and the related systems. Comparison of the putative amino acid sequences of the gene products with those in the Pfam database indicated that and PAS domains which may be involved in signal recognition were extremely abundant in Anabaena: 87 GAF domains in 62 ORFs and 140 PAS domains in 59 ORFs. As for the two-component signal transduction system, 73, 53, and 77 genes for simple sensory His kinases, hybrid His kinases and simple response regulators, respectively, many of which contained additional domains of diverse functions, were presumptively assigned. A total of 52 ORFs encoding putative Hanks-type Ser/Thr protein kinases with various domains such as WD-repeat, GAF and His kinase domains, as well as genes for presumptive protein phosphatases, were also identified. In addition, genes for putative transcription factors and for proteins in the cAMP signal transduction system harbored complex gene structures with multiple domains.

Bacterial Proteins↗
PubMed2001

Novel synthetic approach to 19-nor-1alpha,25-dihydroxyvitamin D(3) and its derivatives by Suzuki-Miyaura coupling in solution and on solid support.

19-nor-1alpha,25-Dihydroxyvitamin D(3) was synthesized by the Suzuki-Miyaura coupling of the A-ring intermediate 3, which was efficiently prepared from readily available 5-(tert-butyldimethylsilyl)oxycyclohex-2-enone (5), with the boronate compound of the C,D-ring portion. The method could be applied to a solid-phase synthesis to prepare the des-C,D derivatives of 19-nor-1alpha,25-dihydroxyvitamin D(3). [reaction: see text]

Calcitriol↗
PubMed2001

Highly stereoselective asymmetric construction of an acyclic carbon skeleton having two adjacent alkyl substituents by Michael addition of optically active allenyltitaniums to alkylidenemalonates.

[reaction: see text]. Enantio-enriched allenyltitaniums prepared in situ by the reaction of optically active secondary propargyl phosphates with a divalent titanium reagent Ti(O-i-Pr)4/2i-PrMgCl react readily with alkylidenemalonates with excellent regio- and diastereoselectivities to afford the Michael addition products with a high optical purity, thus opening up a new asymmetric method for construction of an acyclic carbon skeleton bearing two adjacent alkyl substituents.

Journal Article↗
PubMed2001

Extracellular nicotinamide adenine dinucleotide induces t cell apoptosis in vivo and in vitro.

Incubation of mouse T cells expressing the cell surface enzyme ADP ribosyltransferase with nicotinamide adenine dinucleotide (NAD) had been reported to cause ADP ribosylation of cell surface molecules, inhibition of transmembrane signaling, and suppression of immune responses. In this study, we analyze the reasons for these effects and report that contact of T cells with NAD causes cell death. Naive T cells when incubated with NAD and adoptively transferred into semiallogeneic mice fail to cause graft-vs-host disease, and when injected into syngeneic, T cell-deficient recipients do not reconstitute these mice. Rather, they accumulate in the liver, leading to an increase of apoptotic lymphocytes in this organ. Similar effects are induced by injection of NAD, shown to cause a dramatic increase of apoptotic CD3(+), CD4(+), and CD8(+) cells in the liver. Consistent with this, in vitro incubation of naive T cells with NAD is shown to induce apoptosis. In contrast, no cell death is demonstrable when T cells are activated before incubation with NAD. It is concluded that ecto-NAD, as substrate of ADP ribosyltransferase, acts on naive, but not on activated CD69(+) T cells.

Animals↗
PubMed2001

Cycloprodigiosin hydrocloride suppresses tumor necrosis factor (TNF) alpha-induced transcriptional activation by NF-kappaB.

Cycloprodigiosin hydrochloride (cPrG.HCl) obtained from a marine bacterium Pseudoalteromonas denitrificans induces apoptotic cell death in various cancerous cell lines. cPrG.HCl alone caused a little cytotoxicity in HeLa cells, but it enhanced the apoptotic process progressively when co-administered with tumor necrosis factor (TNF)alpha. Here we studied the effect of cPrG.HCl on TNFalpha-induced activation of the transcription factor nuclear factor kappaB (NF-kappaB). Luciferase gene reporter assays revealed that cPrG.HCl potently suppressed the TNFalpha- and the phorbol myristate acetate-induced activation of NF-kappaB. The suppression occurred in the presence of imidazole, indicating that it was not related to the intracellular acidification resulting from the intrinsic H(+)/Cl(-) symporter activity of cPrG.HCl. cPrG.HCl inhibited neither the TNFalpha-induced phosphorylation and degradation of inhibitor of nuclear factor-kappaB, nor the subsequent nuclear translocation and DNA binding of NF-kappaB. cPrG.HCl also suppressed NF-kappaB-enhanced gene expression induced by Rac1, Cdc42, MEKK1, inhibitor of nuclear factor-kappaalpha (IKKalpha), IKKbeta, and a subunit of NF-kappaB, p65. These results indicate that cPrG.HCl suppresses NF-kappaB-dependent gene expression through the inhibition of transcriptional activation.

Apoptosis↗