Automated PET-only quantification of amyloid deposition with adaptive template and empirically pre-defined ROI.

Amyloid PET is useful for early and/or differential diagnosis of Alzheimer's disease (AD). Quantification of amyloid deposition using PET has been employed to improve diagnosis and to monitor AD therapy, particularly in research. Although MRI is often used for segmentation of gray matter and for spatial normalization into standard Montreal Neurological Institute (MNI) space where region-of-interest (ROI) template is defined, 3D MRI is not always available in clinical practice. The purpose of this study was to examine the feasibility of PET-only amyloid quantification with an adaptive template and a pre-defined standard ROI template that has been empirically generated from typical cases. A total of 68 subjects who underwent brain (11)C-PiB PET were examined. The (11)C-PiB images were non-linearly spatially normalized to the standard MNI T1 atlas using the same transformation parameters of MRI-based normalization. The automatic-anatomical-labeling-ROI (AAL-ROI) template was applied to the PET images. All voxel values were normalized by the mean value of cerebellar cortex to generate the SUVR-scaled images. Eleven typical positive images and eight typical negative images were normalized and averaged, respectively, and were used as the positive and negative template. Positive and negative masks which consist of voxels with SUVR ⩾1.7 were extracted from both templates. Empirical PiB-prone ROI (EPP-ROI) was generated by subtracting the negative mask from the positive mask. The (11)C-PiB image of each subject was non-rigidly normalized to the positive and negative template, respectively, and the one with higher cross-correlation was adopted. The EPP-ROI was then inversely transformed to individual PET images. We evaluated differences of SUVR between standard MRI-based method and PET-only method. We additionally evaluated whether the PET-only method would correctly categorize (11)C-PiB scans as positive or negative. Significant correlation was observed between the SUVRs obtained with AAL-ROI and those with EPP-ROI when MRI-based normalization was used, the latter providing higher SUVR. When EPP-ROI was used, MRI-based method and PET-only method provided almost identical SUVR. All (11)C-PiB scans were correctly categorized into positive and negative using a cutoff value of 1.7 as compared to visual interpretation. The (11)C-PiB SUVR were 2.30 ± 0.24 and 1.25 ± 0.11 for the positive and negative images. PET-only amyloid quantification method with adaptive templates and EPP-ROI can provide accurate, robust and simple amyloid quantification without MRI.

A community cluster of influenza A(H1N1)pdm09 virus exhibiting cross-resistance to oseltamivir and peramivir in Japan, November to December 2013.

Six influenza A(H1N1)pdm09 viruses were detected in Sapporo, Japan, between November and December 2013. All six viruses possessed an H275Y substitution in the neuraminidase protein, which confers cross-resistance to oseltamivir and peramivir. No epidemiological link among the six cases could be identified; none of them had received neuraminidase inhibitors before specimen collection. The haemagglutinin and neuraminidase genes of the six viruses were closely related to one another, suggesting clonal spread of a single resistant virus.

Topological phase transitions driven by magnetic phase transitions in Fe(x)Bi2Te3 (0≤x≤0.1) single crystals.

We propose a phase diagram for Fe(x)Bi2Te3 (0≤x≤0.1) single crystals, which belong to a class of magnetically bulk-doped topological insulators. The evolution of magnetic correlations from ferromagnetic to antiferromagnetic gives rise to topological phase transitions, where the paramagnetic topological insulator of Bi2Te3 turns into a band insulator with ferromagnetic-cluster glassy behavior around x∼0.025, and it further evolves to a topological insulator with valence-bond glassy behavior, which spans over the region from x∼0.03 up to x∼0.1. This phase diagram is verified by measuring magnetization, magnetotransport, and angle-resolved photoemission spectra with theoretical discussions.

Dirac versus Weyl fermions in topological insulators: Adler-Bell-Jackiw anomaly in transport phenomena.

Dirac metals (gapless semiconductors) are believed to turn into Weyl metals when perturbations, which break either time reversal symmetry or inversion symmetry, are employed. However, no experimental evidence has been reported for the existence of Weyl fermions in three dimensions. Applying magnetic fields near the topological phase transition from a topological insulator to a band insulator in Bi1-xSbx we observe not only the weak antilocalization phenomenon in magnetoconductivity near zero magnetic fields (B<0.4 T), but also its upturn above 0.4 T only for E//B. This "incompatible" coexistence between weak antilocalization and "negative" magnetoresistivity is attributed to the Adler-Bell-Jackiw anomaly ("topological" E·B term) in the presence of weak antilocalization corrections.

cDNA cloning of calcineurin heterosubunits from the pheromone gland of the silkmoth, Bombyx mori.

Pheromone biosynthesis activating neuropeptide (PBAN) stimulates the step of fatty acyl reduction in the pheromone biosynthetic pathway of the silkmoth, Bombyx mori. It has been suggested that the intracellular signal transduction of PBAN in B. mori involves Ca(2+), calmodulin, and calcineurin (also known as protein phosphatase 2B). We have cloned two cDNAs encoding calcineurin heterosubunits from a pheromone gland cDNA library of B. mori. The 2,996-bp clone predicts a 495-amino acid protein homologous to the catalytic subunit calcineurin A (CnA) with a molecular mass of 55,968. The deduced amino acid sequence well conserves the calcineurin B (CnB)-binding domain and two subdomains, a calmodulin-binding and an autoinhibitory domain, showing 77-85% and 82% identities to the isoforms of Drosophila melanogaster CnA and human CnA, respectively. On the other hand, the 820-bp clone predicts a 170-amino acid protein homologous to the regulatory subunit CnB with a molecular mass of 19,357. The deduced amino acid sequence well conserves four EF-hand type calcium-binding structures, showing 95% and about 85% identities to D. melanogaster CnB and mammalian CnBs, respectively. A yeast two-hybrid system has demonstrated the molecular interaction between B. mori CnA and CnB. Northern blot analyses revealed that both CnA and CnB genes were expressed in various larval and adult tissues of B. mori. Both transcripts detected in the pheromone gland three days before adult eclosion increased by the day before eclosion and the mRNA levels were found to be high even two days after adult eclosion. Immunohistochemical analysis has revealed that B. mori calcineurin is localized in the cytoplasm of the pheromone-producing cells.

Adult-onset hereditary sensory and autonomic neuropathy accompanied by anosmia but without skin ulceration.

We report a novel type of hereditary sensory and autonomic neuropathy (HSAN) with adult onset in a Japanese family. One male and 2 females of 6 siblings were affected. They developed anosmia initially at the ages of 20-50 years, followed by anhidrosis and sensory loss. Skin ulceration was absent. Both superficial and deep sensation were impaired in the most distal parts of all 4 limbs. Orthostatic hypotension was present in all patients. This is a unique subtype of HSAN distinct from the HSAN I-V described by Dyck.

Primary extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue type in the CNS.

Extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type has been reported in various internal organs. Here a case is reported of MALT lymphoma developing in the cerebellopontine (CP) angle in a patient with Sjogren syndrome, and the concept of MALT lymphoma of the CNS is introduced. Pathologically, the tumor showed inflammatory features of reactive lymphocytic infiltration with follicle formation, but there were slightly atypical lymphocytes and plasmacytes with B-cell markers. These cells invaded reactive follicles, showing follicular colonization, and showed aberrant expression indicating their neoplastic nature. A review of the literature revealed eight cases of MALT lymphoma originating from the dura mater and one from the CP angle. The average age of patients was 50 years (range 28-66 years), and all patients were female. The tumors were slow to develop and the patients were cured after surgical removal and/or additional therapies. It is proposed that MALT lymphoma should be considered as a differential diagnosis of inflammatory pseudotumor of the CNS.

Characterization of receptors of insect cytokine, growth-blocking peptide, in human keratinocyte and insect Sf9 cells.

Insect cytokine, growth-blocking peptide (GBP), enhances cell proliferation of human keratinocyte cells with a potency almost equivalent to that of human epidermal growth factor (EGF). GBP consists of 25 amino acid residues containing a core region that shows a striking similarity to the C-terminal beta-loop domain of EGF and disordered N and C termini. The present study demonstrates that, although GBP lacks the N-terminal half-portion of EGF molecule, at least five amino acids of the disordered N-terminal six-amino acid region are indispensable for affecting the cell growth activity of GBP. Upon stimulating mitogenesis in keratinocyte cells, GBP directly binds and activates their EGF receptors. GBP also effects proliferative activity on insect Sf9 cells through the binding and activation of the specific receptor, which consists of a heterodimeric complex: a binding subunit (60 kDa) and a tyrosine phosphorylation subunit (58 kDa). These results indicate that GBP enhances cell proliferation of human keratinocyte and insect Sf9 cells through the activation of EGF and GBP receptors, respectively.

EP1 and EP4 receptors mediate exocytosis evoked by prostaglandin E(2) in guinea-pig antral mucous cells.

Effects of prostaglandin E(2) (PGE(2)) on exocytosis of mucin were studied in mucous cells isolated from guinea-pig antrum using video-microscopy. Stimulation with PGE(2) elicited a sustained increase in the frequency of exocytotic events in a dose-dependent manner, which was under regulation by both Ca(2+) and cAMP. Stimulation with a selective prostanoid EP4 receptor agonist (ONO-AEI-329, 10 microM), which activates cAMP signals, elicited a sustained increase in the frequency of exocytotic events (30 % of that evoked by 1 microM PGE(2)). Stimulation with an EP1 agonist (17-P-T-PGE(2), 1 microM), which activates Ca(2+) signals, increased the frequency of exocytotic events to a lesser extent (5 % of that evoked by 1 microM PGE(2)), while addition of an EP1 antagonist (ONO-8713, 10 microM) decreased the frequency of exocytotic events (approximately 40 % of that evoked by 1 microM PGE(2)). However, addition of the EP1 agonist potentiated the frequency of exocytotic events evoked by the EP4 agonist or forskolin (which elevates cAMP levels) and increased the sensitivity of the exocytotic events to forskolin. These results suggest that the Ca(2+) signal activated via the EP1 receptor potentiates the cAMP-regulated exocytotic events activated via the EP4 receptor during PGE(2) stimulation, by increasing the sensitivity of the exocytotic response to cAMP. In conclusion, exocytotic events in PGE(2)-stimulated antral mucous cells were regulated by interactions between EP1 and EP4 receptors. Experimental Physiology (2001) 86.4, 451-460.

Animal model of axonal Guillain-Barré syndrome induced by sensitization with GM1 ganglioside.

Some humans develop the axonal form of Guillain-Barré syndrome after receiving bovine brain ganglioside. On sensitization with the ganglioside mixture, all of a group of rabbits injected developed high anti-GM1 IgG antibody titers, flaccid limb weakness of acute onset, and a monophasic illness course. Pathological findings for the peripheral nerves showed predominant Wallerian-like degeneration, with neither lymphocytic infiltration nor demyelination. IgG was deposited on the axons of the anterior roots, and GM1 was proved to be present on the axons of peripheral nerves. Sensitization with purified GM1 also induced axonal neuropathy, indicating that GM1 was the immunogen in the mixture. A model of human axonal Guillain-Barré syndrome has been established that uses inoculation with a bovine brain ganglioside mixture or isolated GM1. This model may help to clarify the molecular pathogenesis of the syndrome and to develop new treatments for it.

Structure and activity of the insect cytokine growth-blocking peptide. Essential regions for mitogenic and hemocyte-stimulating activities are separate.

Growth-blocking peptide (GBP) is a 25-amino acid insect cytokine found in Lepidopteran insects that possesses diverse biological activities such as larval growth regulation, cell proliferation, and stimulation of immune cells (plasmatocytes). The tertiary structure of GBP consists of a structured core that contains a disulfide bridge and a short antiparallel beta-sheet (Tyr(11)-Arg(13) and Cys(19)-Pro(21)) and flexible N and C termini (Glu(1)-Gly(6) and Phe(23)-Gln(25)). In this study, deletion and point mutation analogs of GBP were synthesized to investigate the relationship between the structure of GBP and its mitogenic and plasmatocyte spreading activity. The results indicated that deletion of the N-terminal residue, Glu(1), eliminated all plasmatocyte spreading activity but did not reduce mitogenic activity. In contrast, deletion of Phe(23) along with the remainder of the C terminus destroyed all mitogenic activity but only slightly reduced plasmatocyte spreading activity. Therefore, the minimal structure of GBP containing mitogenic activity is 2-23 GBP, whereas that with plasmatocyte spreading activity is 1-22 GBP. NMR analysis indicated that these N- and C-terminal deletion mutants retained a similar core structure to wild-type GBP. Replacement of Asp(16) with either a Glu, Leu, or Asn residue similarly did not alter the core structure of GBP. However, these mutants had no mitogenic activity, although they retained about 50% of their plasmatocyte spreading activity. We conclude that specific residues in the unstructured and structured domains of GBP differentially affect the biological activities of GBP, which suggests the possibility that multifunctional properties of this peptide may be mediated by different forms of a GBP receptor.

Parameters for monitoring treatment effects in CIDP with anti-MAG/SGPG IgM antibody.

We used cycles of plasma exchange and intravenous cyclophosphamide to treat a patient who had chronic inflammatory demyelinating polyneuropathy with anti-myelin-associated glycoprotein/sulfoglucuronylparagloboside IgM antibody. After treatment, serum anti-sulfoglucuronylparagloboside IgM antibody titers were reduced significantly, and clear symptomatic improvement followed. The percentage of CD57-positive lymphocytes and natural killer cell activity had also returned to normal. Our findings indicate that serial measurements of these parameters are useful for monitoring treatment effect in this disease.

Reversed-phase liquid chromatographic separation of enantiomers on polysaccharide type chiral stationary phases.

The direct chiral separation by chiral stationary phases (CSPs) is one of the most important techniques to analyze enantiomeric purity as well as to get enantiomerically pure material quickly. Among various types of CSPs, polysaccharide type CSPs are well known by their versatility and durability. They are not only effective under normal-phase conditions, but also under reversed-phase conditions. In order to get a good separation under the reversed-phase conditions, it is the key to choose an appropriate mobile phase. For example, a simple mixture of water/acetonitrile or water/methanol are sufficient for a neutral analyte, while it is necessary to use an acidic solution instead of water for an acidic analyte and a solution of a chaotropic salt (or a basic solution) for a basic analyte, respectively. The paper also presents lists of more than 350 separation examples that include 22 validated methods for drug analyses from serum, plasma, or urine samples on polysaccharide type CSPs under reversed-phase conditions.

Platelet aggregation and coagulation and fibrinolysis parameters in both portal and systemic circulations in patients with cirrhosis and hepatocellular carcinoma.

A tendency to bleed and local vasodilation in the portal circulation are exacerbatory clinical factors in patients with liver cirrhosis. Esophageal variceal bleeding, in particular, is a frequent complication in these patients. Cirrhotic patients have been reported to show impairment of platelet aggregation and an activated fibrinolytic state, possibly with consequential lengthening of the bleeding time. Our previous study has demonstrated enhanced generation of PGI(2), a vasodilating and anti-platelet aggregating hormone, in the portal circulation of cirrhotic patients. In the present study, we compared the platelet aggregation and coagulation and fibrinolytic profiles in portal circulation with those in systemic circulation in twenty cirrhotic patients complicated with hepatocellular carcinoma. A portal blood sample was collected through a fine needle inserted percutaneously and guided ultrasonographically to the intrahepatic portal vein. Simultaneously, venous blood was drawn from a forearm vein as the systemic blood sample. Coagulation and fibrinolytic profiles were assessed by examining the extrinsic fibrinolytic system (tissue plasminogen activator (tPA), t-PA-plasminogen activator inhibitor complex), fibrinogen degeneration product, fibrinogen euglobulin lysis time, platelet count, and platelet aggregation elicited by ADP and collagen. Although fibrinolytic factors were activated in patients in the present study, there were no significant differences between the portal and systemic blood samples in all the coagulation and fibrinolytic parameters examined except for platelet aggregation. The curve of platelet aggregation response to collagen (1, 2, 10 µg/ml), but not that to ADP, shifted significantly more to the right in the portal blood compared to the systemic blood (P<0.05). This result suggested that the difference in prostaglandin generation reported previously, may cause the dissociation between collagen and ADP elicitation of platelet response in portal blood while there is no effect on other parameters in the coagulation and fibrinolytic profiles.

Evaluation of Bayesian predictability of vancomycin concentration in patients with various degrees of renal function.

To assess the usefulness of the population pharmacokinetic parameters of vancomycin (VCM) based on a two-compartment model in Japanese adult patients, predictability by a Bayesian method was evaluated using a concentration time course after single dosing to 22 patients with various degrees of renal function. Using one or two points from the observed data for each patient, the concentrations predicted by a Bayesian method were compared with the observed data for each sampling time. The patients were separated into five groups based on their renal functions indicated by creatinine clearance, and the mean prediction error (MPE) and root mean squared error (RMSE) were calculated for each group as measures of accuracy and precision, respectively. In both one- and two-point methods, the absolute MPE values at each sampling time in the elimination phase were less than 2.5 microg/ml, and the RMSE values were also small. No clear differences were found in MPE and RMSE among the groups. In the distribution phase, the MPE and RMSE were somewhat greater, and RMSE in some groups was around 15 microg/ml when trough data was used to predict the peak concentration. Also, the theoretical RMSE using this population parameter setting could well explain the observed RMSE. These results confirmed this population parameter setting is useful for at least predicting concentration in the elimination phase after single dosing, and the predictability was independent of renal function.

Pharmacokinetics and adverse events following 5-day repeated administration of lenograstim, a recombinant human granulocyte colony-stimulating factor, in healthy subjects.

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) (lenograstim) was administered to healthy subjects at doses of 2, 5 and 10 micrograms/kg/day for 5 days (twice a day subcutaneously) to examine the optimal dose and schedule of lenograstim in mobilizing peripheral blood progenitor cells (PBSC) for allogeneic transplantation. Lenograstim administration significantly increased CD34+ cells in a dose-related manner. A significant correlation was observed between the maximal post-dosing counts and the pre-dosing baseline counts of CD34+ cells. Peripheral neutrophils increased markedly by seven to 13 times from the baseline to a peak of approximately 40,000/microliter on day 5 for the 5 and 10 micrograms/kg/day doses. After peak serum concentration (Cmax) was attained 4 h following administration, serum G-CSF declined with time in a log-linear fashion. The Cmax and 12 h area-under-the-curve increased dose dependently, but minimum drug level increased up to day 2 and then decreased until day 5. Clearance decreased with increasing dosage at the first dose, and increased significantly at the last dose. We found a highly significant correlation between absolute neutrophil counts and clearance for each dose. Adverse events most frequently occurred on day 6, with increases of alkaline phosphatase and lactate dehydrogenase and onset of bone pain. Increases of aspartate aminotransferase and alanine aminotransferase occurred as delayed events. Platelet count gradually decreased after the end of drug administration to 57% of the pre-dosing count on day 10, but was still within the normal range. These preliminary results suggest that repeated doses of lenograstim induce mobilization of PBSC in a dose-dependent manner and the pre-dosing baseline count of PBSC may predict the post-dosing maximal mobilization. The drug treatment may cause delayed-onset moderate thrombocytopenia and increased transaminase, and the drug clearance changes in a complex manner during repeated dosing.

Congenital neuropathy with the absence of large myelinated fibers.

Twelve patients with hereditary motor and sensory neuropathy with the absence of large myelinated fibers have been reported. All of these patients had central nervous system involvement. In this report, we describe the first patient with pure motor and sensory neuropathy with the absence of large myelinated fibers without central nervous system involvement. Morphometric analysis of the biopsied sural nerve specimen revealed extremely small myelinated fibers compared with previously reported patients. It is supposed that the cause of this disease might be the abnormal development of axons of the peripheral nerves.

Genotype analysis of the CYP2C19 gene in HCV-seropositive patients with cirrhosis and hepatocellular carcinoma.

This study was conducted to assess whether the genotypic frequency of Smephenytoin 4'-hydroxylase CYP2C19 gene differs in Japanese cirrhotic patients who developed hepatocellular carcinoma. Thirty-eight patients with cirrhosis were studied. The wild-type allele CYP2C19*1 and the two mutated alleles, CYP2C19*2 and CYP2C19*3, were identified by PCR-RFLP method. Individuals with homozygous CYP2C19*2 or CYP2C19*3 mutation and those with CYP2C19*2 and CYP2C19*3 heterozygous mutation were predicted to be the poor metabolizer (PM) phenotype. The overall frequency of PM predicted from the genotyping analysis was 29% (11 of the 38 patients), consisting of 5 patients homozygous for CYP2C19*2, two homozygous for CYP2C19*3 and four heterozygous for the two defects. Among 24 HCV-seropositive patients with cirrhosis and hepatocellular carcinoma, the frequency of PM was 41.7% and significantly higher than that observed in 186 healthy controls. We postulate that the PM phenotype caused by the mutation of CYP2C19 gene in cirrhotic patients with HCV infection is associated with a high risk for developing hepatocellular carcinoma.

Distribution of growth-blocking peptide in the insect central nervous tissue.

Parasitization of the armyworm Pseudaletia separata by the endoparasitic wasp Cotesia kariyai inhibits larval growth and delays pupation, conditions necessary for proper maturation of the parasite larvae. Parasitization is correlated with an elevated level of a 25-amino-acid hormone-like peptide, growth-blocking peptide (GBP, ENFSGGCVAGYMRTPDGRCKPTFYQ). Injection of synthetic GBP into nonparasitized larvae dose dependently mimics the effects of parasitization by delaying the larval development. Here we studied the relationship between parasitization and both the production and distribution of GBP in central nervous tissues. We found that parasitization is correlated with an elevated expression of GBP mRNA, and increased concentrations of both proGBP and GBP in the host insect brain and subesophageal ganglion. The increase in proGBP precedes that of the mature GBP by about 12 h. In situ hybridization analysis using sections of parasitized and nonparasitized larval brains showed strong expression of GBP mRNA in perineural cells and/or class I neuroglia in the rind of both larval brains. The expression in parasitized larval brain-subesophageal ganglion is approximately two- to threefold higher than that in nonparasitized larvae. The presence of GBP in insect neural tissue, and its role in inhibiting growth, suggest an involvement in the regulation of neurosecretory cells.