Evaluation of the predictive performance of a pharmacokinetic model for propofol in Japanese macaques (Macaca fuscata fuscata)

Propofol is a short-acting intravenous anesthetic used for induction/maintenance anesthesia. The objective of this study was to assess a population pharmacokinetic (PPK) model for Japanese macaques during a step-down infusion of propofol. Five male Japanese macaques were immobilized with ketamine (10 mg/kg) and atropine (0.02 mg/kg). A bolus dose of propofol (5 mg/kg) was administrated intravenously (360 mg/kg/h) followed by step-down infusion at 40 mg/kg/h for 10 min, 20 mg/kg/h for 10 min, and then 15 mg/kg/h for 100 min. Venous blood samples were repeatedly collected following the administration. The plasma concentration of propofol (Cp) was measured by high-speed LC-FL. PPK analyses were performed using NONMEM VII. Median absolute prediction error and median prediction error (MDPE), the indices of prediction inaccuracy and bias, respectively, were calculated, and PE - individual MDPE vs. time was depicted to show the variability of prediction errors. In addition, we developed another population pharmacokinetic model using previous and current datasets. The previous PK model achieved stable prediction of propofol Cp throughout the study period, although it underestimates Cp. The step-down infusion regimen described in this study would be feasible in macaques during noninvasive procedures.

Effect of the C-terminal domain of Vibrio proteolyticus chitinase A on the chitinolytic activity in association with pH changes

AIMS

To reveal the cause of the difference in activity of chitinase A from Vibrio proteolyticus and chitinase A from a strain of Vibrio carchariae (a junior synonym of Vibrio harveyi), we investigated the pH-dependent activity of full-length V. proteolyticus chitinase A and a truncated recombinant corresponding to the V. harveyi form of chitinase A.

METHODS AND RESULTS

After overexpression in Escherichia coli strain DH5α, the full-length and truncated recombinant chitinases were purified by ammonium sulphate precipitation and anion exchange column chromatography. Chitinase activity was measured at various pH values using α-crystal and colloidal chitins as the substrate. The pH-dependent patterns of the relative specific activities for α-crystal chitin differed between the full-length and truncated recombinant chitinases, whereas those for colloidal chitin were similar to each other.

CONCLUSION

The difference in the activity of V. proteolyticus chitinase A and V. harveyi chitinase A might be partly due to a change in the pH dependence of the chitinase activities against α-crystal chitin, resulting from C-terminal processing.

SIGNIFICANCE AND IMPACT OF STUDY

The present results are important findings for not only ecological studies on the genus Vibrio in association with survival strategies, but also phylogenetic studies.

Delimitation of a QTL region controlling cold tolerance at booting stage of a cultivar, 'Lijiangxintuanheigu', in rice, Oryza sativa L

Low temperature at the booting stage of rice causes male sterility resulting in severe yield loss. Cold tolerance has long been an important objective in rice breeding. We identified a quantitative trait locus (QTL) for cold tolerance on the long arm of chromosome 3 from the cold-tolerant breeding line 'Ukei 840' by using F(2) and BC(1)F(2) populations from crosses between 'Ukei 840' and 'Hitomebore'. The cold tolerance of 'Ukei 840' is derived from the Chinese cultivar 'Lijiangxintuanheigu'. The effect of this QTL on cold tolerance was confirmed by developing 'Hitomebore' chromosome segment substitution lines having 'Lijiangxintuanheigu' alleles on chromosome 3. By producing recombinants in chromosome 3, the QTL region for cold tolerance was delimited to the region of about 1.2-Mb region between RM3719 and RM7000. All lines heterozygous for the QTL showed seed fertilities as low as that of 'Hitomebore', suggesting that the 'Lijiangxintuanheigu' allele for cold tolerance in the QTL region is recessive. Determination of a 1.2-Mb nucleotide sequence of 'Ukei 840' and comparison with the published genomic sequence of 'Nipponbare' showed 254 SNPs, of which 11 were in coding regions of genes, seven in five genes being non-synonymous. SNPs were detected in the 5-kb upstream regions of 89 genes, but no differences of gene expression levels were detected between alleles of these genes. Although further delimitation is required to identify the gene responsible for cold tolerance of 'Lijiangxintuanheigu', SNP markers developed here will be useful for marker-assisted selection in a breeding program using 'Lijiangxintuanheigu' as a donor of cold tolerance.

P4-05-05: Imaging Mass Spectrometry Based Lipid Metabolites Analysis for Breast Cancer

Background: Activation of lipid metabolism is an early event of carcinogenesis and a central hallmark of many cancers including breast cancer. Recent findings argue that stearoyl CoA desaturase-1 (SCD1), a key regulator of the fatty acid (FA) composition and the endoplasmic reticulum resident enzyme that converts saturated FA (SFA) into monounsaturated FA (MUFA) is a novel regulator of carcinogenesis. The distinctive lipids composition of membrane in cancer cells and the biological functions of SCD1, however, still remain uncertain. Imaging mass spectrometry (IMS) is a mass spectrometry-based analyzing technique that enables visualization of the individual molecules without requiring antibodies. It allows comprehensive detection of a wide range of biomolecules, such as lipids. We attempted to visualize the localization of lipids in breast cancer by IMS for better understanding of cancer proliferation.

Materials and methods: 13 specimens were obtained from the primary breast cancer patients. All were Japanese woman and aged 41–86 years (mean 61.5y.o.). Only one patient received preoperative systematic therapy. 6 were estrogen receptor (ER) and/or progesterone receptor (PgR) positive and human epidermal growth factor receptor 2 (HER2) negative, 2 were ER and/or PgR positive and HER2 positive, 2 were both ER and PgR negative and HER2 positive and 2 were triple negative.

IMS: Samples were immediately chilled in liquid Hexan and stored at −80°. All specimens were sliced into 10 mm thin sections, mounted onto one indium-tin oxide-coated glass slides (Bruker Daltonics) and then sprayed by 2,5-Dihydroxybenzoic acid. Matrix assisted laser desorption ionization (MALDI) technique was used as a soft ionization method. We used time of flight (TOF)/TOF type instrument (Ultraflex, Bruker Daltonics) and all the spectrum were acquired automatically using Fleximaging software (Bruker Daltonics). Each spectral intensity at any mass-to-charge ratio (m/z) was measured at 16 regions of interest (ROI); 13 ROI were picked up from cancerous parts and 3 were from non-cancerous parts. Spectral intensities were compared and statistical analysis was performed by Mann Whitney test. The software was also used to create two-dimensional ion-density maps.

Results: In the cancerous parts of all the 13 specimens, two distinct peaks of the molecular ions were detected at m/z 798.5 and 810.5, which were not found in the non-cancerous parts. Median intensity of the molecular ions at m/z 798.5 and 810.5 were 38.9 and 3.18 in the cancerous part, while they were 0.84 and 1.02 in the non-cancerous part (p=0.010 and 0.015, respectively). Tandem mass spectrometry analysis for these two molecules revealed that they were two kinds of phosphatidylcholine (PC), PC (16:0/18:1) and PC (18:0/18:1). Localization of the individual PC was visualized by means of IMS, which showed that in cancerous part accumulation of PCs containing MUFA was more pronounced than those containing SFA only. Conclusion:

Two kinds of PC containing MUFA were found to highly accumulate in cancerous parts, which may suggest involvement of SCD1 in the membrane composition regulation and cancer proliferation. Further studies may thus be warranted to explore the relation between PC localization and the SCD1 expression.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-05-05.

Heterodisaccharide 4-O-(N-acetyl-β-D-glucosaminyl)-D-glucosamine is an effective chemotactic attractant for Vibrio bacteria that produce chitin oligosaccharide deacetylase

AIMS

To investigate the attractant effect of 4-O-(N-acetyl-β-D-glucosaminyl)-D-glucosamine (GlcNAc-GlcN) in the chemotaxis of Vibrio bacteria that produce carbohydrate esterase (CE) family 4 chitin oligosaccharide deacetylase (COD), an enzyme that catalyzes the production of GlcNAc-GlcN from N,N'-diacetylchitobiose (GlcNAc)(2).

METHODS AND RESULTS

The chemotactic effect of disaccharides from chitin on several strains of Vibrio bacteria was investigated using an agar gel lane-migration method. The results demonstrated that GlcNAc-GlcN functions as an effective chemoattractant in the CE family 4 COD-producing vibrios, Vibrio parahaemolyticus and Vibrio alginolyticus. In contrast, this phenomenon was not observed in Vibrio nereis or Vibrio furnissii, which lack genes encoding this enzyme. From transmission electron microscope observation of V. parahaemolyticus cells following the chemotaxis assay, GlcNAc-GlcN appears to stimulate polar flagellum rotation.

CONCLUSIONS

GlcNAc-GlcN is a specific chemoattractant for the CE family 4 COD-producing vibrios, V. parahaemolyticus and V. alginolyticus.

SIGNIFICANCE AND IMPACT OF THE STUDY

It was clarified for the first time that GlcNAc-GlcN functions as a signalling molecule in the chemotaxis of Vibrio bacteria that have an ability to produce CE family 4 COD, which generate GlcNAc-GlcN from (GlcNAc)(2).

Dominant-negative effects of a novel mutation in the filamin myopathy

BACKGROUND

Filamin myopathy is associated with mutations in the filamin C gene (FLNC) and is a myofibrillar myopathy characterized by focal myofibrillar destruction and cytoplasmic aggregates containing several Z-disk-related proteins.

METHODS

This study investigated 6 Japanese patients with dominantly inherited myofibrillar myopathy manifested by adult-onset, slow and progressive muscle weakness and atrophy in the distal extremities.

RESULTS

The abundantly expressed proteins in the affected muscles were identified as filamin C by nano liquid chromatography-tandem mass spectrometry. A genetic analysis of FLNC identified a heterozygous c.8107delG mutation that was localized to the dimerization domain of filamin C. A biochemical crosslinking analysis of bacterially expressed recombinant wild-type and mutant filamin C fragments demonstrated that the mutant monomer disturbed the proper dimerization of the wild-type filamin dimer, resulting in formation of a heterotrimer with the wild-type filamin dimer. The expression study in C2C12 myoblasts showed that the mutant filamin fragments formed cytoplasmic aggregates with endogenous wild-type filamin C.

CONCLUSIONS

This study provides evidence for the dominant-negative effects of the FLNC mutation. These effects may be mutation-specific and likely result in the variation in the clinical phenotypes seen in patients with filamin myopathy.

Genetic analysis of interspecific incompatibility in Brassica rapa

In interspecific pollination of Brassica rapa stigmas with Brassica oleracea pollen grains, pollen tubes cannot penetrate stigma tissues. This trait, called interspecific incompatibility, is similar to self-incompatibility in pollen tube behaviors of rejected pollen grains. Since some B. rapa lines have no interspecific incompatibility, genetic analysis of interspecific incompatibility was performed using two F(2) populations. Analysis with an F(2) population between an interspecific-incompatible line and a self-compatible cultivar 'Yellow sarson' having non-functional alleles of S-locus genes and MLPK, the stigmas of which are compatible with B. oleracea pollen grains, revealed no involvement of the S locus and MLPK in the difference of their interspecific incompatibility phenotypes. In QTL analysis of the strength of interspecific incompatibility, three peaks of LOD scores were found, but their LOD scores were as high as the threshold value, and the variance explained by each QTL was small. QTL analysis using another F(2) population derived from selected parents having the highest and lowest levels of interspecific incompatibility revealed five QTLs with high LOD scores, which did not correspond to those found in the former population. The QTL having the highest LOD score was found in linkage group A02. The effect of this QTL on interspecific incompatibility was confirmed by analyzing backcrossed progeny. Based on synteny of this QTL region with Arabidopsis thaliana chromosome 5, a possible candidate gene, which might be involved in interspecific incompatibility, is discussed.

Comparative Studies on S-Glycoproteins Purified from Different S-Genotypes in Self-Incompatible BRASSICA Species I. Purification and Chemical Properties

S-glycoproteins, i.e. stigma glycoproteins that are heritable in correlation with S allele in self-incompatible Brassica species, were apparently purified for three S alleles in B. oleracea. From SDS gel electrophoresis, the estimated molecular weight for two of the S-glycoproteins was 57,000. The other S-glycoprotein was considered to be heterogeneous with molecular weights of 60,000 and 65,000. Distinct differences in amino acid content were found; in general, cysteine, methionine and histidine were low, and serine, glutamate, glycine, leucine, arginine and aspartate were high and variable between the S-glycoproteins. Differences in the isoelectric point were mainly attributed to the amino acid composition of each S-glycoprotein.

Assessment of genetic diversity of accessions in Brassicaceae genetic resources by frequency distribution analysis of S haplotypes

Plant genetic resources are important sources of genetic variation for improving crop varieties as breeding materials. Conservation of such resources of allogamous species requires maintenance of the genetic diversity within each accession to avoid inbreeding depression and loss of rare alleles. For assessment of genetic diversity in the self-incompatibility locus (S locus), which is critically involved in the chance of mating, we developed a dot-blot genotyping method for self-incompatibility (S) haplotypes and applied it to indigenous, miscellaneous landraces of Brassica rapa, provided by the IPK Gene Bank (Gatersleben, Germany) and the Tohoku University Brassica Seed Bank (Sendai, Japan), in which landraces are maintained using different population sizes. This method effectively determined S genotypes of more than 500 individuals from the focal landraces. Although our results suggest that these landraces might possess sufficient numbers of S haplotypes, the strong reduction of frequencies of recessive S haplotypes occurred, probably owing to genetic drift. Based on these results, we herein discuss an appropriate way to conserve genetic diversity of allogamous plant resources in a gene bank.

Development of PCR markers to detect the glb1 and Lgc1 mutations for the production of low easy-to-digest protein rice varieties

Limiting the ingestion of protein is the fundamental idea in the diet therapy for patients with chronic renal failure. Two mutations involved in the content of major rice storage proteins useful for developing low easy-to-digest protein rice variety have been isolated. The glb1 mutation causes the deficiency of alpha-globulin, and the Lgc1 mutation reduces the glutelin content. By combining the glb1 and the Lgc1 mutations, it is possible to reduce the easy-to-digest protein content by approximately 50%. The Lgc1 mutation has been shown to be caused by a 3.5-kb deletion between the glutelin structural genes, GluB4 and GluB5, while the molecular basis of glb1 mutation has been less understood. PCR analysis of the glb1 mutation revealed a 62.8-kb deletion, including the structural gene of alpha-globulin. Based on these lines of information, we generated PCR markers that make it possible to detect the glb1 and Lgc1 mutations. Using those PCR markers, we genotyped F(2) plants segregating for the glb1 mutation and the Lgc1 mutation and confirmed the consistency of genotype and phenotype. Because the PCR marker sets can distinguish heterozygotes, they will be very useful in developing new varieties of low easy-to-digest protein rice.

A pilot study of proton beam theary for mucosal melanoma of the head and neck

e17042

Background: The aim of this study is to clarify the clinical profile of proton beam therapy for mucosal melanoma of the head and neck. Methods: Patients with mucosal melanoma of the head and neck fulfilling the following criteria were enrolled: histologically confirmed malignant melanoma; N0 and M0 disease. Proton therapy was delivered three times a week with planned total dose of 60 GyE in 15 fractions. Results: From January 2004 through January 2007, thirteen patients were enrolled in this study. Patients’ characteristics were as follows: median age, 75 years (range, 56 to 79); male/female, 7/6; T1/2/3/4/rec, 3/2/0/7/1. All could receive the full dose of proton therapy. The most common acute toxicities were mucositis (grade 3: 15%) and dermatitis (grade 2: 15%). One patient had unilateral impairment of visual acuity possibly related with treatment. Initial local control rate was 77.0% (10/13, 95%CI: 46.2–95.0%). With median follow up period of 33.7 months, median progression free survival was 18.9 months and median survival time was not reached. 2-year overall survival rate was 69.7% (95%CI: 31.6–86.1%). Most frequent site of first failure was cervical lymph nodes outside of PTV. Four patients died of disease; cachexia caused by distant metastases in three and carotid blowout because of nodal disease in one. Conclusions: Proton beam therapy for mucosal melanoma of the head and neck achieved favorable results in this limited number of patients, although further investigation about late toxicity is needed. Now, the phase II study of this treatment is ongoing.

No significant financial relationships to disclose.

Type-1.5 superconductivity

We demonstrate the existence of a novel superconducting state in high quality two-component MgB2 single crystalline superconductors where a unique combination of both type-1 (lambda{1}/xi{1}<1/sqrt[2]) and type-2 (lambda{2}/xi{2}>1/sqrt[2]) superconductor conditions is realized for the two components of the order parameter. This condition leads to a vortex-vortex interaction attractive at long distances and repulsive at short distances, which stabilizes unconventional stripe- and gossamerlike vortex patterns that we have visualized in this type-1.5 superconductor using Bitter decoration and also reproduced in numerical simulations.

Novel QTLs for photoperiodic flowering revealed by using reciprocal backcross inbred lines from crosses between japonica rice cultivars

The rice japonica cultivars Nipponbare and Koshihikari differ in heading date and response of heading to photoperiod (photoperiod sensitivity). Using simple sequence repeat (SSR) and single nucleotide polymorphism (SNP) markers, we conducted quantitative trait locus (QTL) analyses for heading date in a set of reciprocal backcross inbred lines (BILs) from crosses between Nipponbare and Koshihikari. Under natural-day conditions, transgressive segregation in days to heading (DTH) toward both early and late heading was observed in both BIL populations. QTL analyses revealed that two QTLs--on chromosomes 3 and 6--were involved in the difference in heading date between the parental cultivars. The Nipponbare allele at the QTLs on chromosomes 3 and 6 showed, respectively, increasing and decreasing effects on DTH in both BIL populations. The transgressive segregation observed in the BILs could be accounted for mainly by the complementary action of a set of alleles with opposing effects. Both QTLs were finely mapped as single Mendelian factors in secondary mapping populations (BC2F2 plants/BC2F3 lines). The QTL on chromosome 3 was mapped in the 1,140-kb interval between 94O03-4 (SSR) and OJ21G19-4 (SNP) and was designated Hd16. The QTL on chromosome 6 was mapped in the 328-kb interval between P548D347 (SSR) and 0007O20 (SSR) and was designated Hd17. Both Hd16 and Hd17 were involved in photoperiod sensitivity, as revealed by observation of the DTH of nearly isogenic lines of Nipponbare under short- and long-day conditions, suggesting that allelic differences in both Hd16 and Hd17 account for most of the difference in photoperiod sensitivity between the parental cultivars.