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Biomedical subjects

M Saiki

Publications and source records attributed to M Saiki.

At least 19 recordsLinked to original sources
PubMed2006

Varicose veins associated with CADASIL result from a novel mutation in the Notch3 gene.

No genetically diagnosed cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) pedigrees with venous insufficiency have been described. In a CADASIL pedigree with varicose veins, the authors have identified a novel heterozygous mutation in the 3' splice acceptor site of intron 15 of the Notch3 gene. This, based on mRNA analysis, resulted in skipping of exon 16 including eight cysteine residues of EGF-like repeats.

Adult↗
PubMed2006

Assessment of atmospheric metallic pollution in the metropolitan region of São Paulo, Brazil, employing Tillandsia usneoides L. as biomonitor.

Tillandsia usneoides L. is an epiphytic bromeliad plant able to absorb water and nutrients directly from the air. For this reason this species was selected to carry out a monitoring study of air pollution in the metropolitan region of São Paulo, Brazil. Five consecutive transplantation experiments (8 weeks each) were performed in 10 sites of the city, submitted to different sources of air pollution (industrial, vehicular), using plants collected from an unpolluted area. After exposure, trace metals were analyzed in the plant by instrumental neutron activation analysis. Traffic-related elements such as Zn and Ba presented high concentrations in exposure sites near to heavy traffic avenues (cars, buses and trucks) and may be associated to vehicular sources. For Zn and Co the highest contents were related to industrial zones and can be associated to the presence of anthropogenic emission sources. The rare earth elements, Fe and Rb, probably have soil particles as main source.

Air Pollutants↗
PubMed2005

Characterization of trace elements in Casearia medicinal plant by neutron activation analysis.

Leaves of Casearia sylvestris, Casearia decandra and Casearia obliqua plant species, collected at the Atlantic Forest in Brazil, were analyzed by using instrumental neutron activation analysis (INAA). Short and long irradiations using thermal neutron flux of the IEA-R1 nuclear reactor were carried out for these analyses. Concentrations of Ca, K and Mg were found in these samples at the percentage levels, Br, Cl, Fe, Mn, Na, Rb and Zn at the microg g(-1) levels and Co, Cr, Cs, La, and Sc at the microg kg(-1) levels. Comparisons were made among the element concentrations obtained in these three Casearia species and significant differences were found for the elements Cl, Co, Cs, Cr, La, Mn, Na and Sc. The precision and the accuracy of the results were evaluated by analyzing the certified reference materials NIST-1515 Apple Leaves and NIST-1573a Tomato Leaves.

Casearia↗
PubMed2005

Diesel emissions significantly influence composition and mutagenicity of ambient particles: a case study in São Paulo, Brazil.

In 2003, a bus strike paralyzed the fleet of buses in Sao Paulo, Brazil during 3 days, from 6 to 8 of April, the complete interruption of services being achieved on the 7th. We evaluated the effect of the absence of this source of pollution on the composition, mutagenicity, and toxicity of the fine particulate material collected during this period. Particles were sampled in glass fiber filters on days 7 and 15 of April of 2003 (strike and nonstrike days, respectively), using a high-volume sampler. Trace element determinations (As, Br, Co, Cl, Fe, La, Mn, Sb, Sc, and Th) of particulate material samples were carried out by neutron activation analysis. Sulfur determination was done by X-ray fluorescence analysis. The ratio between nonstrike/strike concentrations of hydrocarbons associated with automotive emissions (benzene, toluene, ethyl-benzene, and xylenes; BTEX) was determined by gas chromatography/mass spectrometry. Mutagenesis of testing solutions was determined by means of the Tradescantia micronucleus assay in early tetrads of Tradescantia pallida. The inhibition of mitosis of the cells of the primary meristema of the root tips of Allium cepa was used as an index of the toxicity. Fine particle trace element contents were lower during the strike. The concentrations of sulfur and BTEX were 50% and 39.3% lower, respectively, on the strike day. A significant (P=0.038) reduction of micronuclei induced by fine particles sampled during the strike was observed. No effect of the strike on toxicity was detected. These results indicate that a program aiming to reduce emissions of the bus fleet in our town may impact positively the air quality by reducing the mutagenic potential of ambient particles.

Air Pollutants↗
PubMed2005

WT1 expression level and clinical factors in multiple myeloma.

Although Wilm's Tuomor gene (WT1) was first identified as a tumor suppressor gene for Wilm's tumor, WT1 overexpression has been detected in different malignant cell types including leukemia. Increased expression of WT1 in acute leukemia is potentially used as a marker of minimal residual disease. However, the significance of the gene for multiple myeloma is still not clear. To determine the clinical relevance of WT1 expression in multiple myeloma, we examined the association of clinical parameters and WT1 expression in bone marrow for 17 newly diagnosed multiple myeloma patients. WT1 was assessed by real-time quantitative polymerase chain reaction (RQ-PCR) and calculated standardized WT1 expression level per 100 plasma cells in the bone marrow specimen as "corrected WT1". The expression of standardized WT1 and corrected WT1 in myeloma was 59 to 1,600 copies/microg RNA and 0.05 to 406.3 copies/microg RNA/100 plasma cells, respectively, lower than in leukemia. WT1 transcripts increased when clinical factors worsen, including the stage, amount of M protein, Hb, platelet count, blood urea nitrogen (BUN), creatinine, serum alkaline phosphatase (ALP), calcium, beta2-microglobulin, thymidine kinase activity (TK), and C-reactive protein (CRP). In conclusion, the expression level of WT1 could be an additional marker to the standard parameters considered in risk assessment for multiple myeloma.

Biomarkers, Tumor↗
PubMed2004

Long-term accumulation of uranium in bones of Wistar rats as a function of intake dosages.

Groups of Wistar rats were fed with ration doped with uranyl nitrate at concentration A ranging from 0.5 to 100 ppm, starting after the weaning period and lasting until the postpuberty period when the animals were sacrificed. Uranium in the ashes of bones was determined by neutron activation analysis. It was found that the uranium concentration in the bones, as a function of A, exhibits a change in its slope at approximately 20 ppm-a probable consequence of the malfunctioning of kidneys. The uranium transfer coefficient was obtained and an analytical expression was fitted into the data, thus allowing extrapolation down to low doses. Internal and localized doses were calculated. Absorbed doses exceeded the critical dose, even for the lowest uranium dosage.

Animals↗
PubMed2004

Acute pulmonary and hematological effects of two types of particle surrogates are influenced by their elemental composition.

Several epidemiological studies have consistently demonstrated significant associations between ambient levels of particulate matter and lung injury and cardiovascular events with increased morbidity and mortality. Particle surrogates (PS), such as residual oil fly ash (ROFA), have been widely used in experimental studies aimed at characterizing the mechanisms of particle toxicity. Since PS composition varies depending on its source, studies with different types of PS may provide clues about the relative toxicity of the components generated by high-temperature combustion process. In this work, we have studied the effects of nasal instillation of increasing doses of different PS in mice: saline, carbon, and two types of particle surrogates. PS type A (PSA) was the ROFA collected from the waste incinerator of our university hospital; PS type B (PSB) was collected from the electrostatic precipitator of a large steel company and thus had an elevated metal content. After 24h, we analyzed hematological parameters, fibrinogen, bronchoalveolar lavage, bone marrow, and pulmonary histology. Nasal instillation of the two types of PS-induced leucopenia. PSB elicited a greater elevation of plasma fibrinogen levels. Bone marrow and pulmonary inflammatory changes were more intense for PSA. We concluded that the PS composition modulates acute inflammatory changes more significantly than the mass for these two types of PS.

Air Pollutants↗
PubMed2004

Long-term accumulation and microdistribution of uranium in the bone and marrow of beagle dog.

The accumulation and microdistribution of uranium in the bone and marrow of Beagle dogs were determined by both neutron activation and neutron-fission analysis. The experiment started immediately after the weaning period, lasting till maturity. Two animal groups were fed daily with uranyl nitrate at concentrations of 20 and 100 microg g(-1) food. Of the two measuring techniques, uranium accumulated along the marrow as much as in the bone, contrary to the results obtained with single, acute doses. The role played by this finding for the evaluation of radiobiological long-term risks is discussed. It was demonstrated, by means of a biokinetical approach, that the long-term accumulation of uranium in bone and marrow could be described by a piling up of single dose daily incorporation.

Animals↗
PubMed2004

Common hepatic artery aneurysm branching from the superior mesenteric artery. Report of a case.

A 58-year-old man was notified as having a mass in the head of the pancreas at medical checkup on September 26, 2000. He was admitted to our department after being diagnosed as having an aneurysm in the common hepatic artery, branching from the superior mesenteric artery (SMA), based on selective SMA angiography. From an abdominal midline incision, we were able to reach his common hepatic artery aneurysm (CHAA) by mobilizing the pancreas through the route lateral to the greater curvature of the stomach. This aneurysm arose in the common hepatic artery immediately after branching from the SMA. After proximal and distal control of the SMA and common hepatic artery, the aneurysm was incised and the distal hepatic artery was anastomosed end to side to the SMA. The patient had an uneventful postoperative course.

Age Distribution↗
PubMed2003

Mutation in the CHAC gene in a family of autosomal dominant chorea-acanthocytosis.

Although mutations in the CHAC gene have been identified in autosomal recessive chorea-acanthocytosis (AR-ChAc), the molecular basis of autosomal dominant ChAc (AD-ChAc) remains to be determined. The authors investigated abnormalities in the CHAC gene in an AD-ChAc family with mRNA and sequencing analyses of mRNA and genomic DNA. A novel single heterozygous mutation in the last nucleotide of exon 57 of the CHAC gene, which could cause skipping of the exon, was detected in affected siblings.

Adult↗
PubMed2003

Rostral lateral pontine infarction: neurological/topographical correlations.

The authors correlated neurologic features of rostral lateral pontine infarct (rLPI) with lesion location on MRI. rLPI is a motor-sensory stroke presenting as crural monoparesis or crural dominant hemiparesis and segmental superficial or deep sensory disturbances. The dorsolateral pontine base causes crural paresis without supranuclear facial palsy.

Aged↗
PubMed2002

[Long time use of percutaneous cardiopulmonary support after cardiovascular operation; clinical problems from our experience].

Result and problems were studied in 12 patients who received percutaneous cardiopulmonary support (PCPS) after cardiac or aortic surgery. Causative diseases included acute myocardial infarction in 7 cases, rupture of the left ventricular septum after infarction, acute mitral valve regurgitation after infarction, rupture of the left ventricular free wall, a stuck valve, and an aortic aneurysm in the thoracicoabdominal region in each 1 case. The time of postoperative PCPS ranged from 2 to 361 hours, and the mean supply flow volume was 1.78 +/- 0.45 l/min/m2. Seven patients could be taken off the treatment or discharged from the hospital (58.3%). The comparison between surviving and non-surviving cases showed a significantly longer assisted circulation time in the latter. An increase of bleeding after surgery was found in all 8 patients who received PCPS for a long period postoperatively. This was assumed to be due to the thrombocytic activation by heparin.

Aged↗
PubMed2001

Quadricuspid aortic valve associated with aortic stenosis and regurgitation.

A 75-year-old man with moderate aortic stenosis and regurgitation admitted due to heart failure underwent uneventful aortic valve replacement with a Carpentier-Edwards pericardial bioprosthesis valve. A quadricuspid aortic valve discovered incidentally during surgery consisted of 4 of different sizes and a supernumerary cusp between the right and noncoronary cusps. No coronary abnormality was involved. Resected cusps showed fibrotic thickening with calcification and no sign of previous inflammatory disease. Although quadricuspid aortic valve is a very rare anomaly, its potential for severe valve failure in adulthood should not be neglected.

Aged↗
PubMed2001

Coprecipitation with lanthanum phosphate as a technique for separation and preconcentration of iron(III) and lead.

The usefulness of coprecipitation with lanthanum phosphate for separation and preconcentration of some heavy metals has been investigated. Although lanthanum phosphate coprecipitates iron(III) and lead quantitatively at pH 2.3, iron(II) can barely be collected at this pH. This coprecipitation technique was applicable to the separation and preconcentration of iron(III) before inductively coupled plasma atomic-emission spectrometric (ICP-AES) determination; the recoveries of iron(III) and iron(II) from spiked water samples were 103-105% and 0.2-0.7%, respectively. The coprecipitation was also useful for separation of 20 microg lead from 100 mL of an aqueous solution that also contained 1-100 mg iron. Coprecipitation of iron was substantially suppressed by addition of ascorbic acid, which enabled recovery of 97-103% of lead added to the solution, bringing the recovery to within 1.6-5.0% of the relative standard deviations. Lanthanum phosphate can also coprecipitate cadmium and indium quantitatively, although chromium(III), cobalt, and nickel and large amounts of sodium, potassium, magnesium, and calcium are barely coprecipitated at pH approximately/= 3.

Journal Article↗
PubMed2001

Automorphogenesis and gravitropism of plant seedlings grown under microgravity conditions.

Plant seedlings exhibit automorphogenesis on clinostats. The occurrence of automorphogenesis was confirmed under microgravity in Space Shuttle STS-95 flight. Rice coleoptiles showed an inclination toward the caryopsis in the basal region and a spontaneous curvature in the same adaxial direction in the elongating region both on a three-dimensional (3-D) clinostat and in space. Both rice roots and Arabidopsis hypocotyls also showed a similar morphology in space and on the 3-D clinostat. In rice coleoptiles, the mechanisms inducing such an automorphic curvature were studied. The faster-expanding convex side of rice coleoptiles showed a higher extensibility of the cell wall than the opposite side. Also, in the convex side, the cell wall thickness was smaller, the turnover of the matrix polysaccharides was more active, and the microtubules oriented more transversely than the concave side, and these differences appear to be causes of the curvature. When rice coleoptiles grown on the 3-D clinostat were placed horizontally, the gravitropic curvature was delayed as compared with control coleoptiles. In clinostatted coleoptiles, the corresponding suppression of the amyloplast development was also observed. Similar results were obtained in Arabidopsis hypocotyls. Thus, the induction of automorphogenesis and a concomitant decrease in graviresponsiveness occurred in plant shoots grown under microgravity conditions.

Arabidopsis↗
PubMed2001

Clinical analysis and prognostic study of ossified ligamentum flavum of the thoracic spine.

OBJECT: A variety of factors may affect surgery-related outcome in patients with ossification of the ligamentum flavum (OLF) of the thoracic spine. The aim of this study was to determine these factors on the basis of preoperative clinical and radiological findings. METHODS: The authors treated 31 cases of symptomatic thoracic OLF between 1988 and 1999. The following factors were retrospectively studied: patient age, sex, morbidity level, initial symptoms, chief complaint, duration of symptoms, patellar reflex, Achilles reflex, computerized tomography (CT) finding, presence of intramedullary change determined by magnetic resonance imaging, coexistent spinal lesions, preoperative grade, and postoperative grade. A decompressive laminectomy was performed in all cases. In 29 patients (94%) improved symptoms were demonstrated postoperatively. In terms of functional prognosis, the preoperative duration of symptoms was significantly shorter in the group of patients with excellent outcomes than in those with fair outcomes (p < 0.05). No significant difference was observed in the correlation between other factors. To evaluate the degree of preoperative thoracic stenosis and the severity/extent of OLF-induced spinal compression, we used an original OLF CT scoring system. A score of excellent on the CT scale tended to indicate an excellent prognosis (p < 0.01). CONCLUSIONS: Thoracic OLF frequently develops in the lower-thoracic spine in middle-aged men, and it is complicated by various spinal lesions in many cases. Early diagnosis and treatment are important for understanding the clinical symptoms and imaging diagnosis because the present findings suggest that a delay in diagnosis and treatment correlates with the functional prognosis postoperatively.

Adult↗
PubMed2001

[Severe thrombocytopenia induced by radiographic non-ionic contrast medium].

A 70-year-old man was admitted to our hospital because of right hemiparesis. He had no allergies or previous exposure to radiographic contrast medium, and the platelet count on admission was within the normal range. On day 8 of hospitalization, he underwent computed tomography of the brain with 100 ml of iopamidol administered intravenously. Three hours later, his platelet count fell to 5,000/microliter, and he developed purpura. Because drug-induced thrombocytopenia was suspected, platelet transfusion was undertaken and corticosteroids were administered. The platelet count returned gradually to normal in 2 days. At the time, we were unable to ascertain the cause of the thrombocytopenia. To clarify whether the contrast medium had been responsible, iopamidol was added to the patient's heparinized whole blood. Subsequent platelet aggregation was observed microscopically and the platelet count decreased, suggesting that the thrombocytopenia had been due to contrast medium-induced platelet aggregation. Although thrombocytopenia after injection of contrast medium is extremely rare, such cases should be evaluated carefully because the condition can be life-threatening if severe.

Aged↗