Modulating the microtubule-tau interactions in biomotility systems by altering the chemical environment.

Obstacles in microtubule mediated neuronal transport can trigger dementia. We use bio-motility assays, that simulate the neuron chemistry in axonopathy, to screen chemicals, that retain the microtubule dynamics in healthy neuronal activity. Tau protein inhibits microtubule activity and leads to oligomerization. Iron(iii) untangles, whereas mono-sodium-glutamate destabilizes the microtubule oligomer.

Isomorphic coalescence of aster cores formed in vitro from microtubules and kinesin motors.

We report fluorescence microscopy studies of the formation of aster-like structures emerging from a cellular element-based active system and a novel analysis of the aster condensation. The system consists of rhodamine labeled microtubules which are dynamically coupled by functionalized kinesin motor proteins cross-linked via streptavidin-coated quantum dots (QDs). The aster-shaped objects contain core structures. The cores are aggregates of the QD-motor protein complexes, and result from the dynamic condensation of sub-clusters that are connected to each other randomly. The structural specificity of the aster core reflects a configuration of the initial connectivity between sub-clusters. Detailed image analysis allows us to extract a novel correlation between the condensation speed and the sub-cluster separation. The size of the core is scaled down during the condensation process, following a power law dependence on the distance between sub-clusters. The exponent of the power law is close to two, as expected from a geometric model. This single exponent common to all the contractile lines implies that there exists a time regime during which an isomorphic contraction of the aster core continues during the condensation process. We analyze the observed contraction by using a model system with potential applicability in a wide range of emergent phenomena in randomly coupled active networks, which are prevalent in the cellular environment.

Experimental and theoretical studies of Si-Cl and Ge-Cl σ-bond activation reactions by iridium-hydride.

We report the iridium hydride-mediated Si-Cl and Ge-Cl σ-bond activation in a low-polarity toluene solution owing to diphosphine-chelation, in which the Si-Cl and Ge-Cl σ-bonds are readily cleaved through an SN2-type pathway via the formation of a free chloride anion.

Development of an (e,2e) electron momentum spectroscopy apparatus using an ultrashort pulsed electron gun.

An (e,2e) apparatus for electron momentum spectroscopy (EMS) has been developed, which employs an ultrashort-pulsed incident electron beam with a repetition rate of 5 kHz and a pulse duration in the order of a picosecond. Its instrumental design and technical details are reported, involving demonstration of a new method for finding time-zero. Furthermore, EMS data for the neutral Ne atom in the ground state measured by using the pulsed electron beam are presented to illustrate the potential abilities of the apparatus for ultrafast molecular dynamics, such as by combining EMS with the pump-and-probe technique.

Impact of immunoreactive substances contained in apheresis platelet concentrate on postoperative respiratory function in surgical patients receiving platelet transfusion: a prospective cohort study.

OBJECTIVES: To construct an alternative policy for the donor selection of platelet concentrate (PC), a clinical study exploring the features of lung injury following PC administration is needed. BACKGROUND: Although a male-donor-only policy for plasma products appears to have efficiently reduced transfusion-related acute lung injury (TRALI), this policy may not be applied to PC because of supply shortages. METHODS AND MATERIALS: We prospectively examined pulmonary function after the transfusion of PC in informed surgical patients treated at a tertiary university hospital in Japan. The contributions of immunoreactive substances contained in the PC to respiratory function after PC transfusion was then statistically examined. RESULTS: Eighty-six patients (56 men, 30 women) were enrolled in the analysis. Fifty-four cases experienced respiratory failure (PaO2 /FiO2 <300 mmHg) after transfusion. Five cases were diagnosed as possible TRALI based on permeability pulmonary oedema, while 23 cases were diagnosed as transfusion-associated circulatory overload (TACO) based on chest radiograph findings. A multivariate logistic regression analysis identified the presence of anti-granulocyte antibody as a significant predictor of possible TRALI [P = 0.023; odds ratio (OR), 13.0; 95% confidence interval (CI), 1.4-118.3]. Meanwhile, anti-leukocyte antibody class II was identified as a significant independent predictor of TACO (P = 0.010; OR, 18.4; 95% CI, 2.0-170.1). CONCLUSIONS: Our data suggest that antibodies contained in PC may contribute to the deterioration of respiratory function after PC transfusion, although the diagnoses of TACO and TRALI may have overlapped among the patients with pulmonary distress in this cohort.

Improvement of the long-term stability for dioxin toxicity evaluation method by enzyme-linked immunosorbent assay.

A dioxin enzyme immunoassay (EIA) is one of the methods that may satisfy the requirements to reduce the cost and turn around time for the dioxin analysis. We developed a dioxin enzyme-linked immunosorbent assay (ELISA) to rapidly analyze for trace levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in human milk. In this study, to aim to supply the stable assay quality, the development of long-term stable coated plates for the ELISA system was reported. To the conventional coated plate (wet plate), the dry plate ELISA indicated the stability to be able to store for 1.5 years at 11 degrees C. The IC(50) of this ELISA was 17 +/- 4 pg/well. The standard curve showed almost the same as that of the wet plate. A fairly good correlation between cross-reactivity of the ELISA and WHO-TEF was achieved for environmental matrices. This ELISA should be more practical for environmental sample monitoring.

Chloroform deposition in renal cyst fluid of hemodialysis patients with renal cystic disorders.

Chronic exposure to chloroform (CHCl3) induces renal neoplasms in rodents and may be carcinogenic in humans, but studies on chronic CHCl3 deposition in the human body have not been performed. In this study, we examined 27 hemodialysis patients with renal cystic diseases including acquired cystic disease of the kidney (ACDK) accompanied by renal tumors at high frequency. Intracystic and serum CHCl3 concentrations were determined using a headspace gas chromatography/mass spectrometry analysis. CHCl3 was not detected in the serum in any cases, but levels ranging from <0.1 to 0.659 mg/L were found in the cyst fluid in most cases, including patients with ACDK and autosomal dominant polycystic kidney disease. Because intracystic CHCl3 deposition was not confined to ACDK cases, we were unable to evaluate the relationship between CHCl3 accumulation and carcinogenesis in ACDK. However, our results suggest that compounds such as CHCl3 accumulate in renal cyst fluid in hemodialysis patients with renal cystic diseases.

Polybrominated diphenyl ethers in human serum and sperm quality.

Polybrominated diphenyl ethers (PBDEs) are widely used flame retardants; currently, they are identified as ubiquitous environmental contaminants. Several studies indicate that PBDEs might affect male fertility. We present the results of a pilot study on the relationship between human serum PBDEs and sperm quality. The PBDE levels in Japan are comparable to those found in European countries. Strong inverse correlations were observed between the serum concentration of 2,2',4,4',5,5'-hexabromodiphenyl ether and sperm concentration (r = -0.841, p = 0.002) and testis size (r = -0.764, p = 0.01). Extensive studies on the relationship between PBDEs and sperm quality are required.

Dietary intake estimations of polybrominated diphenyl ethers (PBDEs) based on a total diet study in Osaka, Japan.

This study presents the results of a total diet study performed for estimating the dietary intake of polybrominated diphenyl ethers (PBDEs) in Osaka, Japan. The concentrations of 36 PBDEs were measured in samples from 14 food groups (Groups I-XIV). PBDEs were detected only in Groups IV (oils and fats), V (legumes and their products), X (fish, shellfish, and their products), and XI (meat and eggs) at concentrations of 1.8, 0.03, 0.48, and 0.01 ng g⁻¹, respectively. For an average person, the lower bound dietary intakes of penta- and deca-formulations were estimated to be 46 and 21 ng day⁻¹, respectively. A high proportion of the decabrominated congener (DeBDE-209) was observed in Group IV. To confirm the presence of DeBDE-209 in vegetable oils, an additional analysis was performed using 18 vegetable oil samples. Of these, seven contained ng g⁻¹ levels of DeBDE-209.

Development of stable isotope dilution quantification liquid chromatography-mass spectrometry method for estimation of exposure levels of bisphenol A, 4-tert-octylphenol, 4-nonylphenol, tetrabromobisphenol A, and pentachlorophenol in indoor air.

The potential risks to human health and reproduction of phenolic xenoestrogens, such as bisphenol A (BPA), 4-tert-octylphenol (OP), 4-nonylphenol (NP), tetrabromobisphenol A (TBBPA), and pentachlorophenol (PCP), have not been fully elucidated. It is possible that healthy humans are exposed to phenolic xenoestrogens in their daily lives. It is also possible that the source of human exposure to trace amounts of phenolic xenoestrogens is indoor air. Therefore, we have established an accurate, sensitive, and selective method for determining BPA, OP, NP, TBBPA, and PCP in air samples by using stable isotope dilution techniques using 13C12-BPA, 4-(1-methyl) octylphenol-d5 (m-OP-d5), 13C12-TBBPA, 13C6-PCP, and liquid chromatography-mass spectrometry (LC-MS). Air sampling (71/min, 24 hours), using glass filters (GB-100R, 47 mm) and Empore SDB-XD filters (47 mm/0.5 mm, 3M, Tokyo, Japan) and subsequent extraction by washing were carried out. Then the extracted sample solution was subjected to LC-MS. The percentage recovery of these analytes ranged from 87.0% to 101.9% (SD 0.2% to 4.6%, n=3) with correction using the stable isotope dilution quantification method. The quantification limit (signal-to-noise ratio, S/N>10) in the air samples was 0.1 ng/m3. Our findings suggest that the LC-MS method can detect low levels of phenolic xenoestrogens in air samples and that these trace levels of analytes exist in indoor air.

Significance of chemokine receptor expression in aggressive NK cell leukemia.

Natural killer (NK) cell-type lymphoproliferative diseases of granular lymphocytes can be subdivided into aggressive NK cell leukemia (ANKL) and chronic NK cell lymphocytosis (CNKL). One reason for the poor outcome in ANKL is leukemic infiltration into multiple organs. The mechanisms of cell trafficking associated with the chemokine system have been investigated in NK cells. To clarify the mechanism of systemic migration of leukemic NK cells, we enrolled nine ANKL and six CNKL cases, and analyzed the expression profiles and functions of chemokine receptors by flowcytometry and chemotaxis assay. CXCR1 was detected on NK cells in all groups, and CCR5 was positive in all ANKL cells. Proliferating NK cells were simultaneously positive for CXCR1 and CCR5 in all ANKL patients examined, and NK cells with this phenotype did not expand in CNKL patients or healthy donors. ANKL cells showed enhanced chemotaxis toward the ligands of these receptors. These results indicated that the chemokine system might play an important role in the pathophysiology of ANKL and that chemokine receptor profiling might be a novel tool for discriminating ANKL cells from benign NK cells.

Epidemiological and outcome characteristics of major burns in Tokyo.

The Tokyo Burn Unit Association (TBUA) was established in 1983 funded by the Tokyo Metropolitan Government, and is organized by 13 burn units in Tokyo. TBUA covers more than 90% of severe burn patients occurring in Tokyo, and all of the cases are registered according to the burn injury registration format. The purpose of this study is to analyze the registered data and to elucidate epidemiological and outcome characteristics of major burn injuries in Tokyo. The total of 6988 hospitalized patients had data for epidemiological analysis, and 6401 patients had complete data for outcome analysis as well, and were included in this study. The characteristic profiles for the analysis included age, sex, cause of burns, inhalation injury, %BSA, burn index (BI), length of burn unit stay, and outcome, and were analyzed by age groups. The mean age of the patients was 40.4 years, and 63% of them were male. It was noteworthy that 25% of the total patients were elderly patients over 60 years of age. Flame was the most common cause making up 45.6% followed by scalding (32.0%). The overall mortality rate was 15.4%. Inhalation injury was accompanied in 27.3% of burn patients. The mortality rate was 34.6% with inhalation injury, and 8.2% without inhalation injury. Causes of death showed that multiple organ failure made up 36.9% of total mortality, followed by sepsis 25.2 and shock 19.0%. The burn size (%BSA and BI) and inhalation injury were the factors for high mortality rate in all age groups whereas age was a predictor for high mortality in the patients older than 16 years of age. Gender was not a factor for high mortality in any age group. The mortality rate showed mildly decreasing tendency since 1995 for which implementation of skin bank was thought to be responsible.

Detection of 1733insC mutations in an Asian family with Birt-Hogg-Dubé syndrome.

BACKGROUND: Birt-Hogg-Dubé syndrome (BHD) is a rare autosomal dominant genodermatosis characterized by skin tumours, including multiple fibrofolliculomas, trichodiscomas and acrochordons. BHD patients also may suffer from associated renal and colonic carcinomas. The defective gene in BHD has been recently identified and is suspected of being a tumour suppressor gene. Several mutations of the BHD gene have been reported only in Caucasian patients. OBJECTIVES: This study reports the first Asian family that has been demonstrated to carry a BHD mutation. PATIENTS/METHODS: The proband was a 26-year-old Japanese man with multiple asymptomatic, soft skin-coloured papules on his face, neck and trunk, which were clinically thought to be acrochordon. His father was also affected. Histopathologically, the papules revealed a fibrofolliculoma that had a circumscribed proliferation of fibroblasts and collagen fibres surrounding an abnormal hair follicle. RESULTS: Mutational analysis of the BHD gene of the proband and the father detected 1733insC, a cytosine insertion mutation in an eight-cytosine tract (nucleotides 1733-1740) in exon 11. Analysis of fibrofolliculoma in the proband showed heterozygous 1733insC mutation, suggesting the absence of loss of heterozygosity. Interestingly, previous mutational analysis in Caucasian patients revealed that both1733insC and 1733delC mutations were hot spots. CONCLUSIONS: This study is the first to find the same hot-spot 1733insC mutation in Asian kindred. The mutations in this polycytosine tract may have a wide, global distribution despite their arising from a different ethnic background.

Determination of di(2-ethylhexyl)phthalate and mono(2-ethylhexyl)phthalate in human serum using liquid chromatography-tandem mass spectrometry.

Concentrations of mono(2-ethylhexyl)phthalate (MEHP), and di(2-ethylhexyl)phthalate (DEHP), in serum of healthy volunteers were determined by high performance liquid chromatography (HPLC) with tandem mass spectrometry (LC/MS/MS). The serum was extracted with acetone, followed by hexane extraction under acidic conditions, and then applied to the LC/MS/MS. Recoveries of 20 ng/ml of MEHP and DEHP were 101+/-5.7 (n=6) and 102+/-6.5% (n=6), respectively. The limits of quantification (LOQ) of MEHP and DEHP in the method were 5.0 and 14.0 ng/ml, respectively. The concentration of MEHP in the serum was at or less than the LOQ. The concentration of DEHP in the serum was less than the LOQ. Contaminations of MEHP and DEHP from experimental reagents, apparatus and air during the procedure were less than the LOQ and were estimated to be <1.0 and 2.2+/-0.6 ng/ml, respectively. After subtraction of the contamination, the net concentrations of MEHP and DEHP in the serum were estimated at or <5 and <2 ng/ml, respectively. To decrease contamination by DEHP, the cleanup steps and the apparatus and solvent usage were minimized in the sample preparation procedures. The high selectivity of LC/MS/MS is the key for obtaining reliable experimental data from in the matrix-rich analytical samples and for maintaining a low level contamination of MEHP and DEHP in this experimental system. This method would be a useful tool for the detection of MEHP and DEHP in serum.

Brain malformations caused by retroviral vector-mediated gene transfer of hippocampal cholinergic neurostimulating peptide precursor protein into the CNS via embryonic mice ventricles.

Hippocampal cholinergic neurostimulating peptide precursor protein (HCNP-pp) is a unique multifunctional protein, being not only the precursor of HCNP, which promotes the phenotype development of septo-hippocampal cholinergic neurons, but also the binding protein of phosphatidylethanolamine, ATP, Raf-1 kinase (known as "Raf-1 kinase inhibitory factor" in peripheral organs), and serine protease. We obtained a high-titer retroviral vector harboring HCNP-pp cDNA by the use of a modified packaging cell line and centrifugation, and by injecting it into embryonic mouse ventricles, we investigated the function of its gene product within the central nervous system (CNS). We found that efficient transduction into hippocampal pyramidal neurons can be achieved by injecting the vector into embryonic brain ventricles on embryonic day 14 (E14). Three days after receiving the intraventricular injection of the high-titer HCNP-pp retrovirus vector on E14, the tissues around the ventricles showed an overexpression of HCNP-pp. This was accompanied by a reduced amount of activated MEK and Erk (as analyzed by histochemical and Western blot methods), suggesting that HCNP-pp also regulates the MAP-kinase cascade within the CNS. Surprisingly, mouse brains that received the HCNP-pp retroviral vector showed massive malformation of the hippocampus and cerebellum when examined 30 days after birth. This shows that strictly regulated HCNP-pp gene expression is necessary for the normal development of the mouse brain, and that the moderate overexpression achieved by retroviral vector-mediated gene transfer is sufficient to cause severe abnormality of entire brain structures.