Apomictic parthenogenesis in a parasitoid wasp Meteorus pulchricornis, uncommon in the haplodiploid order Hymenoptera.

Although apomixis is the most common form of parthenogenesis in diplodiploid arthropods, it is uncommon in the haplodiploid insect order Hymenoptera. We found a new type of spontaneous apomixis in the Hymenoptera, completely lacking meiosis and the expulsion of polar bodies in egg maturation division, on the thelytokous strain of a parasitoid wasp Meteorus pulchricornis (Wesmael) (Braconidae, Euphorinae) on pest lepidopteran larvae Spodoptera litura (Fabricius) (Noctuidae). The absence of the meiotic process was consistent with a non-segregation pattern in the offspring of heterozygous females, and no positive evidence was obtained for the induction of thelytoky by any bacterial symbionts. We discuss the conditions that enable the occurrence of such rare cases of apomictic thelytoky in the Hymenoptera, suggesting the significance of fixed heterosis caused by hybridization or polyploidization, symbiosis with bacterial agents, and occasional sex. Our finding will encourage further genetic studies on parasitoid wasps to use asexual lines more wisely for biological control.

High-Fat Diet-Induced Diabetic Conditions Exacerbate Cognitive Impairment in a Mouse Model of Alzheimer's Disease Via a Specific Tau Phosphorylation Pattern.

BACKGROUND: Epidemiological evidence has demonstrated a clear association between diabetes mellitus and increased risk of Alzheimer's disease (AD). Cerebral accumulation of phosphorylated tau aggregates, a cardinal neuropathological feature of AD, is associated with neurodegeneration and cognitive decline. Clinical and experimental studies indicate that diabetes mellitus affects the development of tau pathology; however, the underlying molecular mechanisms remain unknown. OBJECTIVE: In the present study, we used a unique diabetic AD mouse model to investigate the changes in tau phosphorylation patterns occurring in the diabetic brain. DESIGN: Tau-transgenic mice were fed a high-fat diet (n = 24) to model diabetes mellitus. These mice developed prominent obesity, severe insulin resistance, and mild hyperglycemia, which led to early-onset neurodegeneration and behavioral impairment associated with the accumulation of hyperphosphorylated tau aggregates. RESULTS: Comprehensive phosphoproteomic analysis revealed a unique tau phosphorylation signature in the brains of mice with diabetic AD. Bioinformatic analysis of the phosphoproteomics data revealed putative tau-related kinases and cell signaling pathways involved in the interaction between diabetes mellitus and AD. CONCLUSION: These findings offer potential novel targets that can be used to develop tau-based therapies and biomarkers for use in AD.

Genetic differences and phenotypic plasticity in body size between high- and low-altitude populations of the ground beetle Carabus tosanus.

The body size of a univoltine carabid beetle Carabus tosanus on Shikoku Island, Japan, was clearly smaller in higher-altitude populations (subspecies), which possibly represents incipient speciation. To explore the determinants of altitudinal differences in body size in this species, we studied the degree of phenotypic plasticity by conducting rearing experiments at two constant temperatures and examined genetic differences through interpopulation crosses. At 15 °C, C. tosanus had a longer developmental period and a shorter adult body than at 20 °C. Nevertheless, variation in body size due to temperature effects (phenotypic plasticity) was small compared to the interpopulation differences, which suggests substantial genetic differences between populations (subspecies) at different altitudes. In F(1) offspring from crosses between a low-altitude (subspecies tosanus) and a high-altitude population (subspecies ishizuchianus), adult body length was affected by the genotypes of both parents, with an interaction effect of parental genotype and offspring sex. Further analyses revealed that adult body length was affected by sex-linked factors in addition to autosomal factors. These genetic differences in body size may have resulted from adaptations to different altitudes and may be important for the process of incipient speciation because body size differences could contribute to premating reproductive isolation.

Development and evaluation of 'disaster preparedness' educational programme for pregnant women.

PURPOSE: The objective of this study is the development and evaluation of the usability of an educational programme that teaches disaster preparedness to pregnant women. METHODS: This intervention study examined an intervention group that attended an educational programme and a control group that did not. The subjects were pregnant women in their second trimester. The programme was developed with prior studies and evaluated by self-administered questionnaires that asked about disaster preparedness. The questionnaire was administered twice to the participants in both groups: to the intervention group just before the childbirth class and 1 month after the class, and to the control group at the time of their maternity examination and 1 month afterwards. Two hundred twenty-six members of the intervention group and 262 members of the control group responded to both questionnaires. Of these, 99 of the intervention group and 104 of the control group were primiparous without disaster experience, and the programme was evaluated by comparing these two groups. Effects due to the disaster experience were also analysed within the intervention group. RESULTS: Among primiparous without disaster experience, an intervention effect was found in items concerning awareness modification (five of six items) and behaviour modification (three of seven items). The intervention effect was particularly pronounced in a comparison of primiparous without disaster experience. CONCLUSIONS: An intervention effect was found among the pregnant women who took the programme. In particular, it was statistically significant among primiparous without disaster experience, which suggests that the programme should be shaped to reflect this subject demographic.

[Acute pulmonary embolism after colorectal surgery].

A 84-year-old woman presented with abdominal pain and tarry stools. She was admitted to our hospital, and colonofiberscopy showed type II tumor located cecum. We prevented deep vein thrombosis and acute pulmonary embolism (APE) after abdominal surgery by using the elastic stockings and intermittent pneumatic compression system in operation room. She underwent ileocecal resection and lymphonodi dissection (D2). On 2nd postoperative day, she complained of sudden respiratory distress with loss of consciousness and went into the state of shock. We made the diagnosis of APE after reviewing chest computed tomography and cardiac echo. An emergency atrial and pulmonary thromboembolectomy under cardiopulmonary bypass was performed. We removed the thrombus from right atrium and bilateral main pulmonary artery. After operation, we inserted a temporary vena cava filter into vena cava. We performed the anticoagulant therapy by continuous infusion of heparin with assisting respiration by respirator. The pulmonary artery pressure became steady about 25 approximately 30 mmHg. On 14th postoperative day, we extubated tracheotube. On 40th postoperative day, she could discharge from hospital on foot. Early diagnosis and prompt treatment for APE are important, and we should always keep APE in mind after abdominal surgery.

[Tricuspid valve plasty associated with removal of an infected pacemaker lead: report of a case].

We performed tricuspid valve plasty in a 72-year-old woman with pacemaker lead infection and septicemia. All the infected pacemaker system was removed under cardiopulmonary bypass. Because of advanced adhesion and infection, we needed partial resection and plasty of the tricuspid valve. Postoperative echocardiography revealed only mild tricuspid regurgitation and the recurrence of infection has been avoided. Our technique of valve plasty was useful in a patient with advanced infection of both pacemaker leads and tricuspid valve leaflets.

Leucine zipper motif of chicken histone acetyltransferase-1 is essential for in vivo and in vitro interactions with the p48 subunit of chicken chromatin assembly factor-1.

We cloned cDNA encoding chicken cytoplasmic histone acetyltransferase-1, chHAT-1, comprising 408 amino acids including a putative initiation Met. It exhibits 80.4% identity to the human homolog and possesses a typical leucine zipper motif. The glutathione S:-transferase (GST) pull-down assay, involving truncated and missense mutants of the chicken chromatin assembly factor-1 (chCAF-1)p48, revealed not only that a region (comprising amino acids 376-405 of chCAF-1p48 and containing the seventh WD dipeptide motif) binds to chHAT-1 in vitro, but also that mutation of the motif has no influence on the in vitro interaction. The GST pull-down assay, involving truncated and missense chHAT-1 mutants, established that a region, comprising amino acids 380-408 of chHAT-1 and containing the leucine zipper motif, is required for its in vitro interaction with chCAF-1p48. In addition, mutation of each of four Leu residues in the leucine zipper motif prevents the in vitro interaction. The yeast two-hybrid assay revealed that all four Leu residues within the leucine zipper motif of chHAT-1 are necessary for its in vivo interaction with chCAF-1p48. These results indicate not only that the proper leucine zipper motif of chHAT-1 is essential for its interaction with chCAF-1p48, but also that the propeller structure of chCAF-1p48 expected to act as a platform for protein-protein interactions may not be necessary for this interaction of chHAT-1.

Possible involvement of a ubiquitous and several distinct elements in the transcription regulation of the chicken H3 histone gene family.

We have studied possible modes of transcription regulation of four members (H3-II, H3-III, H3-IV and H3-V) of the twelve chicken H3 genes. Results of transient CAT assays using 5'-truncated mutants of H3-IV, together with those reported previously for H3-II and H3-III, indicated that all these four H3 genes possessed a ubiquitous element, the CCAAT sequence, in addition to several distinct elements. Transient CAT assays using the 5'-extended mutants of these four H3 genes showed that the promoter activities decreased with increasing lengths of the 5'-extended fragments, and that the effects were strong for H3-IV and H3-V, but only moderate for H3-II and H3-III.

One allele of the major histone gene cluster is enough for cell proliferation of the DT40 chicken B cell line.

Thirty-nine of the 44 chicken histone genes are located in a major histone gene cluster of 110 kb, the others residing in four separate regions. We generated a heterozygous chicken DT40 mutant, 1/2 delta110 kb, devoid of one allele of the cluster, using gene targeting techniques. Analyses of the mutant revealed that the growth rate of DT40 cells was unchanged even in the absence of one allele of the cluster. Moreover, analyses involving a RNase protection assay, SDS-PAGE or Triton-acid-urea-PAGE revealed not only that in the 1/2 delta110 kb mutant the steady-state levels of total mRNAs of gene families H1, H2A, H2B, H3 and H4 remained constant, but also that the amounts of histones H1, H2A, H2B, H3 and H4 were not changed. A comparison by 2D-PAGE revealed no changes in total cellular protein patterns of the mutant. These observations demonstrate that all the histone gene families have the inherent ability to compensate for the disruption of one allele of the gene cluster, with no influence on cell functions.

Manganese-dependent Dopa/tyrosine sulfation in HepG2 human hepatoma cells: novel Dopa/tyrosine sulfotransferase activities associated with the human monoamine-form phenol sulfotransferase.

Human monoamine (M)-form phenol sulfotransferase (PST) was PCR-cloned and transiently expressed in COS-7 cells. The recombinant enzyme was demonstrated to display not only the previously reported sulfotransferase activity toward dopamine, but also novel manganese-dependent Dopa/tyrosine sulfotransferase activities. These results imply a new functional role of the human M-form PST in the homeostatic regulation of Dopa and tyrosine.

Targeted disruption of an H3-IV/H3-V gene pair causes increased expression of the remaining H3 genes in the chicken DT40 cell line.

The chicken H3 gene family contains 12 members (H3-I to H3-XII). Nine of them belong to two major histone gene clusters, but the genomic locations of the others are unknown. In the DT40 chicken B cell line, H3-IV and H3-V, which are located in inverted orientation and share a 3'-untranslated region of 531 bp, produce about 24% of the steady-state level of total mRNAs from all the H3 genes. To study the nature of these two genes, we carried out targeted integration into DT40 cells of constructs of the H3-IV/H3-V locus. Analysis of the stable transfectants showed that the growth rate of DT40 cells was unchanged in the absence of two copies of the H3-IV/H3-V locus. Furthermore, the remaining H3 genes were shown to be expressed more in the mutants lacking one or two H3-IV/H3-V alleles than DT40 cells, and the steady-state level of total H3 mRNAs remained constant in all the mutant cell lines tested. The levels of mRNAs from the H2B and H1 genes, which are located close to the H3 genes, were unchanged. These results demonstrate that the chicken H3 gene family has the ability to compensate for disruption of H3-IV/H3-V, which are normally responsible for about 24% of total H3 mRNAs.

Targeted disruption of 01H1 encoding a particular H1 histone variant causes changes in protein patterns in the DT40 chicken B cell line.

Six members of the chicken H1 gene family, all of which are located in two major histone gene clusters, have been shown to encode six different protein variants. The intracellular mRNA level from one of them, 01H1, encoding the 01H1 variant composed of 218 amino acid residues, constitutes 9.9% of the total H1 mRNA in the DT40 chicken B cell line. To study the specific role of this particular H1 variant, besides its well-known functions as a linker in chromatin maintenance and as a general repressor of transcription, we used targeted integration to construct heterozygous and homozygous DT40 mutants with disruption of one and two 01H1 alleles, respectively. Analyses of the stable transfectants showed that the growth rate of DT40 was unchanged in the absence of two 01H1 alleles. Moreover, the remaining H1 genes were shown to be expressed more in these mutants than in the wild-type cell lines. Two-dimensional polyacrylamide gel electrophoresis showed that within an almost constant background in the homozygous mutants several cellular proteins newly appeared or increased, while some other proteins disappeared or decreased quantitatively. These variable proteins all differed from those that varied in DT40 mutants deprived of one of the eight chicken H2B genes, H2B-V, encoding a particular H2B variant. These results suggest that the 01H1 variant is involved in the regulation of expression of genes that encode the proteins that vary in 01H1-deleted mutants of DT40 cells.

An approximately half set of histone genes is enough for cell proliferation and a lack of several histone variants causes protein pattern changes in the DT40 chicken B cell line.

Of the 44 chicken histone genes, 39 are located in a major histone gene cluster of 110 kb, the others residing in four separate regions. The 42 sequenced genes encode six H1 variants, three H2A variants, four H2B variants, two H3 variants, and one histone H4. To clarify the influence on cell functions of simultaneous deletion of an approximately half set of the genes and some of the variants, we generated homozygous chicken DT40 mutants by disruption of two allelic segments of 57 kb, containing the 21 genes, using gene targeting techniques. Analyses with antisense RNA probes common or specific for gene families H1, H2A, H2B, H3 and H4 indicated that the remaining members of each of the gene families were expressed more in the mutants than in DT40 cells, resulting in maintenance of constant steady-state levels of mRNAs. Two-dimensional polyacrylamide gel electrophoresis showed that in the mutants several cellular proteins newly appeared or increased, and some other proteins disappeared or decreased quantitatively. These results demonstrate that all the histone gene families have the inherent ability to compensate for the disruption of a fair number of their own constituents. Furthermore, some of the histone variants are involved in regulation of the expression of putative genes that encode the proteins that varied in mutant DT40 cells, this participation is not compensated for by any residual variant of the same histone subtype(s).

Organization of the chicken histone genes in a major gene cluster and generation of an almost complete set of the core histone protein sequences.

We present a detailed picture of the disposition of the histone genes in the chicken genome and an almost complete set of the core histone protein sequences. Thirty-nine histone genes, six H1, nine H2A, eight H2B, eight H3 and eight H4, were located within a histone gene cluster of 110 kb, which was covered by five cosmid clones and two lambda clones. Results of our sequence analyses, together with those reported previously, generated a set of the core histone amino acid sequences as follows: three H2A variants, four H2B variants, two H3 variants and an H4 protein.

Participation of histones and histone-modifying enzymes in cell functions through alterations in chromatin structure.

Alterations in the chromatin structure are preferentially involved in the regulation of cell functions, including gene expression, in eukaryotes. Three types of mechanisms, by which the alterations are caused have been reported: (i) variants of histone subtypes, (ii) chromatin remodeling, and (iii) post-translational modification. This review focuses mainly on the first and third mechanisms, especially on the acetylation of core histones, one of the third mechanisms. Using the gene targeting technique for the DT40 chicken B cell line, we systematically generated a number of mutants, respectively, devoid of particular genes encoding histones and histone deacetylase(s) (HDACs). Most of the H1 and core histone variants should be involved positively or negatively in the transcription regulation of particular genes. Of the chicken HDACs (chHDACs), chHDAC-2 controls the amount of the IgM H-chain at the steps of both transcription and alternative pre-mRNA processing, and chHDAC-3 is essential for cell viability, whereas chHDAC-1 merely affects gene expression in DT40 cells. These results indicate that HDAC family members should participate, in combination with one another, and/or histone acetyltransferase(s) (HATs), in the acetylation of core histones that regulates gene expression through alterations in the chromatin structure.

Relation of intraoperative flow measurement with postoperative quantitative angiographic assessment of coronary artery bypass grafting.

BACKGROUND: It is critical to evaluate the anastomotic quality of coronary artery bypass grafting (CABG) in the operating room. The aim of this study is to determine the validity of intraoperative flow measurement for predicting the quality of CABG by comparison with the postoperative quantitative angiographic evaluation of the grafts. METHODS: Eighty-two grafts, including 37 internal thoracic arteries, were examined intraoperatively with a transit-time flowmeter. Coronary angiograms were performed 14 +/- 5 days after CABG to quantify the diameters at the toe, heel, and anastomosis proper of the grafts. RESULTS: There were significant differences between patent and nonpatent grafts in all intraoperative flow parameters. However, the only cut-off value to distinguish patent from nonpatent was a fast Fourier transformation (FFT) ratio of 1.0. FFT is the ratio of powers of the fundamental frequency and its first harmonic. Postoperative quantitative angiography indicated that the stenosis was greatest at the heel of the anastomosis. The degree of stenosis at the heel of the anastomosis alone correlated significantly with intraoperative mean flow values. CONCLUSIONS: Fast Fourier transformation analysis of flow measurement may be useful to differentiate patent grafts intraoperatively. Intraoperative flow measurement may predict the most stenotic part of the anastomosis.

Theoretical analysis of right gastroepiploic artery grafting to right coronary artery.

BACKGROUND: The right gastroepiploic artery (GEA) has been used as the second reliable arterial graft for coronary artery bypass grafting (CABG). However, concern regarding the flow competition with the recipient coronary artery has remained. METHODS: An application of in situ GEA grafting to the right coronary artery (RCA) was studied by using a theoretical model. The theoretical model of CABG was given variables; ie, the diameters and the lengths of both in situ GEA and proximal segment of the RCA, and the degree of proximal stenosis in the RCA. According to the range of these variables obtained from clinical data, the ratio of the GEA flow to the flow of the RCA distal to the anastomosis was calculated. RESULTS: Main factors to determine the flows in the two parallel paths were the inner diameters of both vessels, and the degree of the proximal stenosis. When the inner diameters of the GEA were 0.5 mm larger than that of the RCA, the GEA carried more than 50% of the total flow of the RCA distal to the anastomosis despite a moderate stenosis in the RCA. When the inner diameter of the GEA was equal to, or 0.5 mm smaller than, that of the RCA, the GEA flow was dominated by the native RCA flow unless the proximal stenosis was critical. CONCLUSIONS: If the inner diameter of the GEA is 0.5 mm larger than that of the RCA, CABG with the GEA can be applied more widely. If not, the application would basically be limited.

A method for determining the distribution of fluoride, calcium and phosphorus in human dental plaque and the effect of a single in vivo fluoride rinse.

A new sampling method, capable of sampling plaque from its surface to its interior for quantitative studies, was modified to meet some of the requirements for the determination of the fluoride and mineral (Ca and P) profiles within dental plaque formed in vivo. Plaque samples were repeatedly collected from the same individual, using special devices, before a single fluoride rinse (900 parts/10(6) fluoride) and 10 min and 24 hr after rinse. The method allowed examination of fluoride, calcium and phosphorus distribution along the entire thickness of plaque. Fluoride content significantly increased throughout the sample 10 min after rinsing, indicating the fluoride had rapidly penetrated into the plaque. Although the elevated fluoride concentrations diminished almost to baseline with 24 hr, a high correlation was found between fluoride and minerals in each plaque fraction. It is concluded that this technique will be useful for evaluating the fluoride and mineral behaviour in the saliva/plaque and plaque/enamel interfaces, and the anti caries efficacy of fluoride applications.

Oral glucose retention, saliva viscosity and flow rate in 5-year-old children.

There are significant differences of glucose retention in site-specificity and individuals. Sixty-two 5-year-old nursery schoolchildren participated in this study on the relation between the viscosity of saliva and flow rate and glucose retention. Each child was instructed to rinse his/her mouth with a glucose solution (0.5 M, 5 ml) and then to spit out. Three minutes after rinsing, glucose retention was determined. Resting saliva was collected by a natural outflow method, then the flow rate was determined. A rotational viscometer was used to determine the viscosity. Glucose retention and flow rate were correlated at the left maxillary primary molars, and glucose retention and viscosity were correlated at the maxillary central primary incisors. It was concluded that glucose retention after glucose mouth rinsing was site-specific, and that glucose retention and the index of decayed, missing and filled primary teeth (dmft) were slightly correlated with the salivary viscosity and flow rate.