Prophage Origin of a Virulent Phage Appearing on Fermentations of Lactobacillus casei S-1

For protection from the abnormal fermentation of Lactobacillus casei S-1 caused by contamination of a virulent phage, FSV, the origin of this phage was studied. Morphologies, viral structural proteins, and DNA structures of three independent isolates of FSV were compared with those of FSW, which is lysogenized in strain S-1. The results showed (i) that the morphology of FSV phages is indistinguishable from that of FSW and (ii) that all viral structural components found in FSW are present in the particles of FSV's. In addition, restriction endonuclease analyses of viral DNA showed that the HindIII-digested fragments of FSW DNA, the sum of which covered at least 94.7% of this phage genome, were conserved in the FSV DNA digests. Results of Southern filter hybridization of the S-1 and prophage-cured cell (C239) DNAs with FSV DNA as a probe revealed that C239 had lost most of the FSV DNA sequence, whereas S-1 had about one copy of the FSV DNA sequence. These results indicate that virulent phage FSV is derived from the lysogenized phage FSW. Therefore, the appearance of FSV can be eliminated by using the prophage-cured derivative of S-1.     

Coordinate induction of AMP deaminase in human atrium with mitochondrial DNA deletion

Despite the heteroplasmic lower population of mitochondrial (mt) DNA deletion, mtDNA deletion is significantly related to the loss of atrial adenine nucleotides. To elucidate its mechanism, we examined the frequency of a 7.4-kb mtDNA deletion, the concentration of adenine nucleotides, and the activity of AMP catabolic enzymes in 10 human right atria obtained from cardiac surgery, using quantitative PCR, HPLC, and immunoprecipitations. The atrial concentrations of ATP, ADP, AMP, and the total adenine nucleotides were significantly lower in patients with deletion than those in patients without deletion, despite the lower frequency of their deletion. The activities of total AMP deaminase (AMPD), liver-type (AMPD 2), and heart-type isoform (AMPD 3) were significantly higher in patients with deletion than in patients without deletion, although there was no significant difference in the cytosolic 5(')-nucleotidase among them. In conclusion, mtDNA deletion coordinately induces AMP deaminase to contribute to the loss of atrial adenine nucleotides through degrading AMP excessively.     

Proliferation of donor mitochondrial DNA in nuclear transfer calves (Bos taurus) derived from cumulus cells

In embryos derived by nuclear-transfer (NT), fusion of donor cell and recipient oocyte caused mitochondrial heteroplasmy. Previous studies from other laboratories have reported either elimination or maintenance of donor-derived mitochondrial DNA (mtDNA) from somatic cells in cloned animals. Here we examined the distribution of donor mtDNA in NT embryos and calves derived from somatic cells. Donor mitochondria were clearly observed by fluorescence labeling in the cytoplasm of NT embryos immediately after fusion; however, fluorescence diminished to undetectable levels at 24 hr after nuclear transfer. By PCR-mediated single-strand conformation polymorphism (PCR-SSCP) analysis, donor mtDNAs were not detected in the NT embryos immediately after fusion (less than 3-4%). In contrast, three of nine NT calves exhibited heteroplasmy with donor cell mtDNA populations ranging from 6 to 40%. These results provide the first evidence of a significant replicative advantage of donor mtDNAs to recipient mtDNAs during the course of embryogenesis in NT calves from somatic cells.     

The microtubule plus-end proteins EB1 and dynactin have differential effects on microtubule polymerization

Several microtubule-binding proteins including EB1, dynactin, APC, and CLIP-170 localize to the plus-ends of growing microtubules. Although these proteins can bind to microtubules independently, evidence for interactions among them has led to the hypothesis of a plus-end complex. Here we clarify the interaction between EB1 and dynactin and show that EB1 binds directly to the N-terminus of the p150(Glued) subunit. One function of a plus-end complex may be to regulate microtubule dynamics. Overexpression of either EB1 or p150(Glued) in cultured cells bundles microtubules, suggesting that each may enhance microtubule stability. The morphology of these bundles, however, differs dramatically, indicating that EB1 and dynactin may act in different ways. Disruption of the dynactin complex augments the bundling effect of EB1, suggesting that dynactin may regulate the effect of EB1 on microtubules. In vitro assays were performed to elucidate the effects of EB1 and p150(Glued) on microtubule polymerization, and they show that p150(Glued) has a potent microtubule nucleation effect, whereas EB1 has a potent elongation effect. Overall microtubule dynamics may result from a balance between the individual effects of plus-end proteins. Differences in the expression and regulation of plus-end proteins in different cell types may underlie previously noted differences in microtubule dynamics.     

mGluR7 Genetics and Alcohol: Intersection Yields Clues for Addiction

Development of addiction to alcohol or other substances can be attributed in part to exposure-dependent modifications at synaptic efficacy leading to an organism which functions at an altered homeostatic setpoint. Genetic factors may also influence setpoints and the stability of the homeostatic system of an organism. Quantitative genetic analysis of voluntary alcohol drinking, and mapping of the involved genes in the quasi-congenic Recombinant QTL Introgression strain system, identified Eac2 as a Quantitative Trait Locus (QTL) on mouse chromosome 6 which explained 18% of the variance with an effect size of 2.09 g/kg/day alcohol consumption, and Grm7 as a quantitative trait gene underlying Eac2 [Vadasz et al. in Neurochem Res 32:1099–1112, 100, Genomics 90:690–702, 102]. In earlier studies, the product of Grm7 mGluR7, a G protein-coupled receptor, has been implicated in stress systems [Mitsukawa et al. in Proc Natl Acad Sci USA 102:18712–18717, 63], anxiety-like behaviors [Cryan et al. in Eur J Neurosci 17:2409–2417, 14], memory [Holscher et al. in Learn Mem 12:450–455, 26], and psychiatric disorders (e.g., [Mick et al. in Am J Med Genet B Neuropsychiatr Genet 147B:1412–1418, 61; Ohtsuki et al. in Schizophr Res 101:9–16, 72; Pergadia et al. in Paper presented at the 38th Annual Meeting of the Behavior Genetics Association, Louisville, Kentucky, USA, 76]. Here, in experiments with mice, we show that (1) Grm7 knockout mice express increased alcohol consumption, (2) sub-congenic, and congenic mice carrying a Grm7 variant characterized by higher Grm7 mRNA drink less alcohol, and show a tendency for higher circadian dark phase motor activity in a wheel running paradigm, respectively, and (3) there are significant genetic differences in Grm7 mRNA abundance in the mouse brain between congenic and background mice identifying brain areas whose function is implicated in addiction related processes. We hypothesize that metabotropic glutamate receptors may function as regulators of homeostasis, and Grm7 (mGluR7) is involved in multiple processes (including stress, circadian activity, reward control, memory, etc.) which interact with substance use and the development of addiction. In conclusion, we suggest that mGluR7 is a significant new therapeutic target in addiction and related neurobehavioral disorders.     

Surface Response of Fluorine Polymer-Incorporated Resin Composites to Cariogenic Biofilm Adherence

Experimental resin composites with incorporated polytetrafluoroethylene (PTFE) particles were developed, which theoretically could improve the surface properties of the materials, including the inhibition of bacterial adherence. To assess the surface properties in relation to biofilm formation and detachment, 23.1% (wt/wt) linear PTFE particles (FL-30) and cross-linked PTFE particles (FC-30) were incorporated into pure resin composites. Pure PTFE plates and pure resin composites without PTFE (F-0) were used as control specimens. Sucrose-dependent Streptococcus mutans biofilms were formed on the specimen blocks inside an oral biofilm reactor for various time periods and analyzed with or without application of driving forces. In addition, water contact angles and surface roughness were measured. The water contact angles of FL-30 (61.2°) and FC-30 (65.8°) were larger than that of F-0 (48.5°). The largest contact angle (107°) was detected on pure PTFE plates. However, the surfaces of FL-30, FC-30, and pure PTFE plates were rougher than that of F-0. Although the surface properties of the materials differed in terms of contact angles and roughness, these factors seemed not to affect biofilm formation on the surfaces within 5 h. Pure PTFE plates harbored almost the same amounts of biofilm as F-0. However, when a very strong driving force was applied, it was clear that there were significantly smaller amounts of biofilms retained on pure PTFE plates, which showed contact angles much higher than those of the other materials. Hydrophobicity of the resin composite was improved by incorporation of PTFE fillers. However, surface resistance against biofilm formation was not improved.     

Significant interaction between LRP2 rs2544390 in intron 1 and alcohol drinking for serum uric acid levels among a Japanese population

A genome-wide association study identified that LRP2 rs2544390 in intron 1 was associated with serum uric acid (SUA) levels among Japanese, as well as polymorphisms of SLC22A12, ABCG2, and SLC2A9. This study aimed to confirm the association of rs2544390 C/T with SUA, as well as another LRP2 polymorphism (rs3755166 G/A) in the promoter. Subjects were 5016 health checkup examinees (3409 males and 1607 females) aged 35 to 69years with creatinine<2.0mg/dL. The subjects with SLC22A12 258WW, SLC2A9 rs11722228C allele, ABCG2 126QQ and 141Q allele (2546 males and 1199 females) were selected for analysis. Mean SUA was 6.03mg/dL for CC, 6.18mg/dL for CT, and 6.19mg/dL for TT among males (p=0.012), and 4.49mg/dL, 4.45mg/dL, and 4.42mg/dL among females (not significant), respectively. No association was observed for rs3755166. The association with rs2544390 was stronger among male drinkers. The odds ratio of drinking ≥5/week relative to no drinking for hyperuricemia (SUA≥7mg/dL and/or under medication for hyperuricemia) was 1.11 (95% confidence interval, 0.67-1.84) among CC males, 1.75 (1.22-2.51) among CT males, and 3.13 (1.80-5.43) among TT males. The interaction terms with drinking ≥5/week were 1.56 (p=0.156) for CT and 2.87 (p=0.005) for TT. This was the first report on the interaction between LRP2 genotype and alcohol drinking for SUA. Since the low density lipoprotein-related protein 2 (megalin) encoded by LRP2 is a multi-ligand endocytic receptor expressed in many tissues including the kidney proximal tubules, the association/interaction remained to be confirmed both epidemiologically and biologically.     

Effects of gender on kidney function in magnesium-deficient rats

This study investigated the gender differences in the kidney function of magnesium (Mg)-deficient rats. Male and female rats were fed a control diet or a Mg-deficient diet for 21 d. Mg-deficient diet had no significant effect on kidney calcium (Ca) or phosphorus (P) concentration in male rats, while Ca and P concentrations in female rats were significantly higher in Mg-deficient rats than in the control rats. With regard to indicators of kidney function, no significant differences in creatinine clearance and serum urea nitrogen concentration were observed among the groups. Serum albumin concentrations were significantly lower in rats fed the Mg-deficient diet than in rats fed the control diet. In both sexes, urinary albumin excretion was significantly higher in rats fed the Mg-deficient diet than in rats fed the control diet. Gender differences had no significant influence on creatinine clearance, serum urea nitrogen concentration, serum albumin concentration and urinary albumin excretion. These results suggest that gender differences have no effect on kidney function in Mg-deficient rats under the condition used.     

Economic Integration in Tanzania (1970–2011): A Biophysical Assessment

This article assesses the impact of economic integration on Tanzania's sociometabolic profile for the years 1970–2011, which witnessed an opening and further integration of Tanzania's economy through increased trade and foreign investment, through a time‐series economy‐wide material flows analysis (EW‐MFA). The EW‐MFA results show that contrary to the trade patterns of many developing countries, increased economic integration has resulted in Tanzania becoming a net importer of resources across all material categories when measured by the physical trade balance indicator. Additionally, the article discusses the conceptual and empirical challenges of measuring ecologically unequal exchange with EW‐MFAs for developing countries whose export profiles are dominated by lightweight, high‐value precious stones and metals. It also assesses the degree to which the Tanzanian economy has undergone dematerialization over the past 40 years of economic integration.