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

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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.

Development of lipid particles targeted via sugar-lipid conjugates as novel nuclear gene delivery system

Efficient nuclear gene delivery is essential for successful gene therapy. This study developed a novel system that mimics the mechanism of nuclear entry of adenovirus (Ad) by means of a Multifunctional Envelope-type Nano Device (MEND). In this system, plasmid DNA (pDNA) was condensed with polycation, followed by encapsulation in a lipid membrane. To target MEND to the nuclear pore complex (NPC), sugar served as a NPC-mediated nuclear targeting device was modified on the surface of the lipid envelope. This was accomplished via synthesis of a sugar-cholesterol conjugate. After binding of the MEND to the NPC, the pDNA core was transferred into the nucleus in conjunction with a breakdown of the lipid envelope. Sugar-modified MEND showed higher transfection efficiency compared with unmodified MEND, in non-dividing and dividing cells. Confocal microscopy confirmed that nuclear transfer of pDNA was improved by sugar modification of MEND. Furthermore, destabilization of the lipid envelope significantly enhanced transfection activity: therefore, nuclear-delivery efficiency was closely related to lipid envelope stability. Moreover, quantitative evaluation of cellular uptake and nuclear transfer processes by real-time PCR confirmed that the surface sugars affected nuclear transfer, but not cellular uptake. In summary, a novel system for the nuclear delivery of pDNA was successfully developed by using a sugar-modified MEND and by optimizing the lipid envelope stability.

Monte Carlo studies on potentiometric titration of (carboxymethyl)cellulose

Monte Carlo simulations of the potentiometric titration are carried out for (carboxymethyl)cellulose in aqueous salt solutions by a previously developed method. A nearly elliptic cylinder with spherical ionizable groups is assumed as model of (carboxymethyl)cellulose molecule. The spherical charges with a hard core potential are adopted as mobile hydrated ions. A fairly satisfactory agreement of the titration curves with the experimental data is achieved by using reasonable molecular dimensions. Dependence of the calculated titration profiles on the molecular model and the characteristics of the system are discussed.

A novel wx mutation caused by insertion of a retrotransposon-like sequence in a glutinous cultivar of rice (Oryza sativa)

DNA polymorphism of the Wx gene in glutinous rice cultivars was investigated by PCR-RF-SSCP and heteroduplex cleavage analysis using Brassica petiole extract, and the nucleotide sequence variations were identified. Most japonica-type glutinous rice was found to have a 23-bp duplication in the second exon, which causes loss of the function of granule-bound starch synthase (GBSS) encoded by the Wx gene. Without the 23-bp duplication, there was an insertion of 7,764 bp in the ninth exon of the wx allele of 'Oragamochi'. Expression analysis of the wx allele using RT-PCR and Northern blot analysis revealed that transcripts of the 'Oragamochi' wx allele are about 1-kb shorter and that the deduced amino acid sequence of the transcript lacks a motif important for GBSS. Therefore, this insertion was considered to be the cause of the glutinous trait of 'Oragamochi'. This 7,764-bp insertion had long terminal repeats, a primer binding site, and a polypurine tract, but no sequence homologous with gag and pol, suggesting that it is a non-autonomous element. Furthermore, it had a structure similar to Dasheng and may be a member of Dasheng.

Tonsillectomy in the treatment of pediatric Henoch-Schönlein nephritis

The exact pathophysiology of HSN remains to be elucidated. Hence, a therapeutic strategy that enables curative treatments for all the various grades of HSN patients has yet to be established. We report our experience performing tonsillectomy combined with steroid therapy for 16 pediatric proteinuric Henoch-Schönlein nephritis (HSN) patients. All patients exhibited hematuria and proteinuria in their first HSN attack with the mean age of onset 7.7 years (range 4.75 - 13.9 years). Nine patients were diagnosed with clinically severe HSN presenting with massive proteinuria (> 1 g/m(2)/day). Renal biopsy findings performed in 6 patients were Grade II (3), Grade III (2) and Grade IV (1) according to the International Study of Kidney Diseases in childhood classification. Tonsillectomy was performed after 1-4 cycles of methylprednisolone pulses during oral prednisolone (0.5 - 1.5 mg/kg/day) therapy. In 2 patients, oral cyclophosphamide therapy was added before the tonsillectomy. The interval between the onset of HSN and tonsillectomy was 97.4 +/- 24.5 days (range 27 424 days). In all patients, proteinuria had disappeared by 6 months after the tonsillectomy and the urine findings had normalized. The interval between therapy initiation and complete remission was 9.6 +/- 2.0 months (range 2 - 26 months). Over follow-up periods of 4.9 +/- 0.6 years (range 2.2 - 9.3 years), no recurrences of Henoch-Schonlein purpura or HSN were observed. There was a significant correlation between early tonsillectomy performance and decreased time until normalization of the urine findings, indicating that the tonsils may have pivotal roles in the initiation and progression of HSN. Their elimination might promote the reversal of nephritis. Although this study is retrospective, we suggested that tonsillectomy at an early stage of HSN may be beneficial by shortening the period of illness and contributing to clinical recovery. Randomized controlled trials will be needed to confirm this supposition.

Purification and characterization of Vibrio parahaemolyticus extracellular chitinase and chitin oligosaccharide deacetylase involved in the production of heterodisaccharide from chitin

A chitin-degrading bacterial strain, KN1699, isolated from Yatsu dry beach (Narashino, Chiba Prefecture, Japan), was identified as Vibrio parahaemolyticus. Treatment of powdered chitin with crude enzyme solution prepared from the supernatant of KN1699 cultures yielded a disaccharide, beta-D-N-acetylglucosaminyl-(1,4)-D-glucosamine (GlcNAc-GlcN), as the primary chitin degradation product. The extracellular enzymes involved in the production of this heterodisaccharide, chitinase (Pa-Chi; molecular mass, 92 kDa) and chitin oligosaccharide deacetylase (Pa-COD; molecular mass, 46 kDa), were isolated from the crude enzyme solution, and their hydrolysis specificities were elucidated. These studies confirmed that (1) Pa-Chi hydrolyzes chitin to produce (GlcNAc)(2) and (2) Pa-COD hydrolyzes the acetamide group of reducing end GlcNAc residue of (GlcNAc)(2). These findings indicate that GlcNAc-GlcN is produced from chitin by the cooperative hydrolytic reactions of both Pa-Chi and Pa-COD.

Relation of tumor vascularity to effect of gemcitabine in pancreatic carcinomas: Value of contrast-enhanced harmonic ultrasonography

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Background: Most ductal adenocarcinomas of the pancreas are hypovascular as compared with the surrounding parenchyma on dynamic CT. Coded phase-inversion harmonic ultrasonography more clearly depicts fine vessels in pancreatic tumors after the infusion of ultrasound contrast than dynamic CT. In the present study, we observed the vascularity of pancreatic tumors by means of this technique and investigated its usefulness for evaluation of response to gemcitabine. Methods: Thirty-three patients with inoperable pancreatic carcinomas were enrolled in this study. They received gemcitabine (1 g/m2) 3 times in a cycle (4 weeks). Contrast-enhanced harmonic ultrasonography (CE-US) was performed immediately before the fist cycle and after completing each cycle, by the use of a GE LOGIQ 9 Series unit. We classified patients into 2 groups according to the changes of tumor vascularity observed by CE-US. Group A represents those with tumors in which tumor vascularity was increased during a certain period after the chemotherapy. Group B represents those with tumors in which tumor vascularity was not increased throughout the observation period. Tumor makers (serum CEA, CA19–9, Span-1 and Dupan-2) and median survival time (MST) were employed for the evaluation of therapeutic response and compared between the 2 groups. Results: CE-US demonstrated the increase of tumor vascularity after the chemotherapy in 17 of 33 patients (Group A). MST in the Group A (306 days) was significantly longer than that in the Group B (187 days). The reduction of tumor makers (reduction by 50 % of either serum CEA, CA19–9, Span-1 or Dupan-2) was observed in all patients (17/17) in the group A and in 25 % of patients (4/16) in the group B. The increase of tumor vascularity was noted when the tumor makers were reduced. The increased vascularity turned to decline in parallel with the tumor progression. Conclusion: CE-US is useful for the evaluation of chemotherapeutic response in terms of vascularity. The increased vascularity in pancreatic carcinomas after the chemotherapy may represent the improvement of vascular sclerosis and tumor invasion in small arterioles.

No significant financial relationships to disclose.

Dot-blot-SNP analysis for practical plant breeding and cultivar identification in rice

We report dot-blot hybridization with allele-specific oligonucleotides for single nucleotide polymorphisms (SNPs) analysis to be applicable for practical plant breeding and cultivar identification. Competitive hybridization of a digoxigenin-labeled oligonucleotide having the sequence of a mutant allele (or a wild-type allele) together with an unlabeled oligonucleotide having the sequence of a wild-type allele (or a mutant allele) was highly effective to reduce background signals in dot-blot hybridization. All 100 tested genes (200 alleles) in rice having SNPs or insertions/deletions were detected in an allele-specific manner. Genotypes of 43 rice cultivars were identified by this technique, and eight SNP markers were found to be sufficient for distinguishing all the cultivars from each other. Dot-blot analysis was also applied to genotyping of Wx and Sd1 of F4 plants in a conventional breeding program. Since dot-blot analysis with competitive hybridization provides a highly reliable, simple, and cost-effective technique for SNP analysis of a large number of samples, this technique is expected to realize the practical use of a novel breeding method, in which plants or breeding lines are selected by SNP analyses of many genes in a laboratory.

Electrostatic potential screened by a two-dimensional electron system: a real-space observation by scanning-tunneling spectroscopy

Scanning-tunneling spectroscopy at 5 K was used to investigate the electrostatic potential profile on the Si(111)-square root of 3 x square root of 3 Ag surface at subnanometer spatial resolution. The potential was measured from an energy-level shift of electronic states on the surface. The potential images obtained reveal that the potential drops around the steps and Ag adsorbates, upon which positive charges are presumably accumulated. The profiles of the reduced potentials are explained with the screening of potential due to the charges by two-dimensional electron gas (2DEG) existing on the surface. The Friedel oscillation, which results from the screening and has a period of the half Fermi wavelength of the 2DEG, was also observed in the potential images.

Decline in Glucokinase Activity in the Arcuate Nucleus of Streptozotocin-Induced Diabetic Rats

Glucokinase (GK) is known to be the critical glucose sensor of pancreatic B-cells. However, the localization and functional role of GK in the brain remains to be elucidated. In this study, we measured both the activity and mRNA level of GK in the hypothalamic nuclei and the cortex of rats injected intraperitoneally with streptozotocin or vehicle. GK activity was measured by a fluorometric assay; and the GK mRNA level, by use of the real-time reverse transcription polymerase chain reaction. GK activity in vehicle-treated rats was high in the arcuate nucleus, moderate or low in the ventromedial nucleus, lateral hypothalamic area, and paraventricular nucleus, and very low in the cortex. The order of GK mRNA level was almost the same as that of GK activity. GK activity and GK mRNA level only in the arcuate nucleus of streptozotocin-treated rats at 7 d, but not at 2 d, after treatment were lower than those of vehicle-treated rats. The results suggest that prolonged hyperglycemia induced by diabetes decreased the activity of GK in the arcuate nucleus.

The transcriptional landscape of the mammalian genome

This study describes comprehensive polling of transcription start and termination sites and analysis of previously unidentified full-length complementary DNAs derived from the mouse genome. We identify the 5' and 3' boundaries of 181,047 transcripts with extensive variation in transcripts arising from alternative promoter usage, splicing, and polyadenylation. There are 16,247 new mouse protein-coding transcripts, including 5154 encoding previously unidentified proteins. Genomic mapping of the transcriptome reveals transcriptional forests, with overlapping transcription on both strands, separated by deserts in which few transcripts are observed. The data provide a comprehensive platform for the comparative analysis of mammalian transcriptional regulation in differentiation and development.

Tenascin-C regulates proliferation and migration of cultured astrocytes in a scratch wound assay

Tenascin-C (TNC), an extracellular matrix glycoprotein, is involved in tissue morphogenesis like embryogenesis, wound healing or tumorigenesis. Astrocytes are known to play major roles in wound healing in the CNS. To elucidate the roles of TNC in wound closure by astrocytes, we have examined the morphological changes of cultured astrocytes in a scratch wound assay and measured the content of soluble TNC released into the medium. We have also localized the expression of TNC mRNA, TNC, glial fibrillary acidic protein (GFAP), vimentin and integrin beta1. After wounding, glial cells rapidly released the largest TNC isoform and proliferated in the border zones. Subsequently, they became polarized with unidirectional processes and finally migrated toward the denuded area. The proliferating border zone cells and pre-migratory cells intensely expressed TNC mRNA, TNC-, vimentin-, GFAP- and integrin beta1-like immunoreactivity, while the migratory cells showed generally reduced expression except the front. Exogenous TNC enhanced cell proliferation and migration, while functional blocking with anti-TNC or anti-integrin beta1 antibody reduced both of them. These results suggest that mechanical injury induces boundary astrocytes to produce and release TNC that promotes cell proliferation and migration via integrin beta1 in an autocrine/paracrine fashion.

Nuclear factor {kappa}B inactivation in the rat liver ameliorates short term total warm ischaemia/reperfusion injury

BACKGROUND

In hepatic ischaemia/reperfusion injury, activated liver macrophages (Kupffer cells) are dominantly regulated by a transcription factor, nuclear factor kappaB (NFkappaB), with respect to expression of inflammatory cytokines, acute phase response proteins, and cell adhesion molecules.

AIMS

We assessed whether inactivation of NFkappaB in the liver could attenuate total hepatic warm ischaemia/reperfusion injury.

METHODS

We studied rats with hepatic overexpression of inhibitor kappaBalpha super-repressor (IkappaBalpha SR) caused by a transgene introduced using an adenoviral vector. Hepatic ischaemia/reperfusion injury was induced under warm conditions by total occlusion of hepatoduodenal ligament structures for 20 minutes, followed by reperfusion. Controls included uninfected and control virus (AdLacZ) infected rats.

RESULTS

IkappaBalpha SR was overexpressed in Kupffer cells as well as in hepatocytes, blocking nuclear translocation of NFkappaB (p65) into the nucleus after reperfusion. Gene transfection with IkappaBalpha SR, but not with LacZ, markedly attenuated ischaemia/reperfusion injury, suppressing inducible nitric oxide synthase and nitrotyrosine expression in the liver. Moreover, no remarkable hepatocyte apoptosis was detected under IkappaBalpha SR overexpression.

CONCLUSIONS

Adenoviral transfer of the IkappaBalpha SR gene in the liver ameliorates short term warm ischaemia/reperfusion injury, possibly through attenuation of hepatic macrophage activation.

Genes outside the S supergene suppress S functions in buckwheat (Fagopyrum esculentum)

BACKGROUND AND AIMS

Common buckwheat (Fagopyrum esculentum) is a dimorphic self-incompatible plant with either pin or thrum flowers. The S supergene is thought to govern self-incompatibility, flower morphology and pollen size in buckwheat. Two major types of self-fertile lines have been reported. One is a type with long-homostyle flowers, Kyukei SC2 (KSC2), and the other is a type with short-homostyle flowers, Pennline 10. To clarify whether the locus controlling flower morphology and self-fertility of Pennline 10 is the same as that of KSC2, pollen tube tests and genetic analysis have been performed.

METHODS

Pollen tube growth was assessed in the styles and flower morphology of KSC2, Pennline 10, F1 and F2 plants that were produced by the crosses between plants with pin or thrum and Pennline 10.

KEY RESULTS

Pollen tubes of Pennline 10 reached ovules of all flower types. The flower morphology of F1 plants produced by the cross between thrum and Pennline 10 were thrum or pin, and when pin plants were used as maternal plants, all the F1 plants were pin. Both plants with pin or short-pin flowers, whose ratio of style length to anther height was smaller than that of pin, appeared in F2 populations of thrum x Pennline 10 as well as in those of pin x Pennline 10.

CONCLUSION

The results suggest that Pennline 10 possesses the s allele as pin does, not an allele produced by the recombination in the S supergene, and that the short style length of Pennline 10 is controlled by multiple genes outside the S supergene.

Spontaneous regeneration of the corticospinal tract after transection in young rats: a key role of reactive astrocytes in making favorable and unfavorable conditions for regeneration

We demonstrated the occurrence of marked regeneration of the corticospinal tract (CST) after a single transection and failure of regeneration after a repeated transection in young rats. To provide convincing evidence for the complete transection and regeneration we used retrograde neuronal double labeling. Double-labeled neurons that took up the first tracer from the transection site and the second tracer from the injection site caudal to the transection site were observed in the sensorimotor cortex. The anterograde tracing method revealed various patterns of regeneration. In the most successful cases the vast majority of regenerated fibers descended in the normal tract and terminated normally whereas a trace amount of fibers coursed aberrantly. In the less successful cases fibers descended partly normally and partly aberrantly or totally aberrantly. To clarify the role of astrocytes in determining the success or failure of regeneration we compared expression of glial fibrillary acidic protein (GFAP), vimentin and neurofilament (NF) immunoreactivity (IR) in the lesion between single and repeated transections. In either transection, astrocytes disappeared from the CST near the lesion site as early as 3 h after lesioning. However, by 24 h after a single transection, immature astrocytes coexpressing GFAP- and vimentin-IR appeared in the former astrocyte-free area and NF-positive axons crossed the lesion. By contrast, after a repeated transection the astrocyte-free area spread and NF-positive axons never crossed the lesion. It appears likely that the major sign, and possibly cause of failure of regeneration is the prolonged disappearance of astrocytes in the lesioned tract area.