Molecular characterization of the genes involved in the secretion and immunity of lactococcin Q, a two-peptide bacteriocin produced by Lactococcus lactis QU 4.

Lactococcin Q is a two-peptide (Qα and Qß) bacteriocin produced by Lactococcus lactis QU 4, which exhibits specific antimicrobial activity against L. lactis strains. The lactococcin Q gene cluster (approximately 4.5 kb) was sequenced and found to include genes encoding lactococcin Q immunity (laqC), an ATP-binding cassette transporter (laqD) and a transport accessory protein (laqE), downstream of the lactococcin Q structural genes (laqA and laqB). In addition, the gene cluster showed high sequence identity with that of a lactococcin Q homologue bacteriocin, lactococcin G. Heterologous expression studies showed that LaqD was responsible for lactococcin Q secretion in a manner dependent on LaqE expression, and that LaqC conferred self-immunity to lactococcin Q and cross-immunity to lactococcin G. Amino acid alignment of both lactococcin transporters revealed that LaqD contains an insertion (160-168 residues) that is essential for lactococcin Q secretion, as L. lactis cells that expressed LaqDΔ160-168 were devoid of this function. Additional experiments demonstrated that the LaqDΔ160-168 mutant was, however, able to secrete lactococcin G, suggesting that the insertion is necessary only for the lactococcin Q secretion by LaqD. This report demonstrates the biosynthetic mechanism of lactococcin Q/G-type bacteriocins and the complementarity of the genes responsible for the secretion of lactococcins Q and G.

Effectiveness of ethinylestradiol/drospirenone for premenstrual symptoms in Japanese patients with dysmenorrhea: Open-label pilot study.

AIM: A combined oral contraceptive containing ethinylestradiol 20 µg plus drospirenone 3 mg (EE20 + DRSP) in a 24/4 regimen has been shown to alleviate the symptoms of premenstrual syndrome and premenstrual dysphoric disorder. This study was conducted to evaluate the efficacy of EE20 + DRSP in Japanese patients with premenstrual symptoms. MATERIAL AND METHODS: A multicenter, prospective, open-label, single-arm, phase IV study was performed in Japanese women with dysmenorrhea and premenstrual symptoms. They were treated with EE20 + DRSP to alleviate the symptoms of dysmenorrhea for six treatment cycles. Premenstrual symptoms were evaluated using a Premenstrual Symptoms Questionnaire at baseline and after three and six cycles of EE20 + DRSP. The degree of dysmenorrhea was also evaluated using a visual analog scale at baseline and after one, three, and six cycles of EE20 + DRSP. RESULTS: Forty-eight patients were treated with EE20 + DRSP. Most of the premenstrual symptoms were alleviated significantly by three and six cycles of EE20 + DRSP treatment. EE20 + DRSP treatment significantly improved the severity of premenstrual symptoms. We also confirmed the effectiveness of EE20 + DRSP for the treatment for dysmenorrhea. CONCLUSION: This study showed that EE20 + DRSP could be a useful treatment strategy for premenstrual symptoms in Japanese women.

Novel method for the fabrication of a charge-transfer complex crystal by photoirradiation.

A novel method for the fabrication of a charge-transfer complex crystal was developed. Photoirradiation of a solution of TPP[Co(tbp)(CN)(2)] and TPP[Co(Pc)(CN)(2)] (tbp=tetrabenzoporphyrin, Pc=phthalocyanine, TPP=tetraphenylphosphonium) gave a molecular conducting crystal of a charge-transfer complex TPP[Co(tbp)(CN)(2)](2), which was produced by the process in which the photoexcited electron in tbp was transferred from the LUMO of tbp to that of Pc.

Premenstrual symptoms and posttraumatic stress disorder in Japanese high school students 9 months after the great East-Japan earthquake.

On March 11, 2011, the Great East-Japan Earthquake occurred and a massive tsunami hit the northeastern coast of Japan. Catastrophic disasters such as earthquakes and war cause tremendous damage, not only physically but also mentally. Posttraumatic stress disorder (PTSD) is an anxiety disorder that occurs in the aftermath of a traumatic event. Premenstrual syndrome (PMS) is a cluster of psychological and somatic symptoms that are limited to the late luteal phase of the menstrual cycle. Premenstrual dysphoric disorder (PMDD) is considered a severe form of PMS. To determine the relationship between premenstrual symptoms and natural disaster-induced PTSD among Japanese adolescent girls, we conducted a cross-sectional study. Overall, 1489 high school students who belong to two high schools in Sendai, the largest city in northeastern Japan, were assessed 9 months after the earthquake. These schools are located inland, far from the seashore, and were not damaged by the tsunami. Premenstrual symptoms were assessed using the Premenstrual Symptoms Questionnaire, and PTSD symptoms were assessed using the Japanese-language version of Impact of Event Scale-Revised, which is a widely used self-assessment questionnaire about PTSD symptoms. We analyzed the data of 1,180 girls who completed the questionnaires and 118 girls (10.0%) were classified as having PTSD. The prevalence rates of PMDD and moderate to severe PMS increased according to the comorbidity of PTSD (p < 0.001), showing a correlation between the severity of PMS/PMDD and natural disaster-induced PTSD. The comorbidity of PMS/PMDD and PTSD may complicate the follow-up of both conditions.

Relationship between premenstrual symptoms and dysmenorrhea in Japanese high school students.

To determine the relationship between premenstrual symptoms and dysmenorrhea among Japanese adolescent girls, a total of 1,431 high school students were assessed. Of them, 11.3% were classified with "moderate to severe premenstrual syndrome (PMS)" and 3.2% with "premenstrual dysphoric disorder (PMDD)." Eighty-five percent of the girls had dysmenorrhea. The rates of prevalence of PMDD and moderate to severe PMS were increased according to the severity of dysmenorrhea (rs = 0.479), showing a correlation between the severity of PMS/PMDD and dysmenorrhea in adolescents.

Prevalence of premenstrual syndrome and premenstrual dysphoric disorder in Japanese high school students.

To determine the prevalence and the impact of premenstrual symptoms among Japanese adolescent girls, a total of 618 high school students were assessed. Of them, 64.6% were found to suffer from premenstrual symptoms, which is lower than that in adult women. On the other hand, the rates of prevalence of moderate to severe PMS and PMDD in girls were higher than those in adult women. Premenstrual symptoms could have significant consequences by interfering with the daily functioning of adolescent girls.

In vitro synergistic activities of cefazolin and nisin A against mastitis pathogens.

First-generation cephalosporins such as cefazolin (CEZ) have been widely used for mastitis treatment in dairy cattle. However, the use of antibiotics results in the presence of antibiotic residues in milk, which is used for human consumption. Nisin A, a bacteriocin produced by Lactococcus lactis, has been used as a broad-spectrum food preservative for over 50 years. Therefore, a combination of CEZ and nisin A might provide an extended activity spectrum against mastitis pathogens and reduce the antibiotic dose for mastitis treatment. This study aimed to evaluate the combined effect of CEZ and nisin A against mastitis pathogens using the checkerboard and time-kill assays. In the checkerboard assay, the CEZ-nisin A combination exhibited a synergistic effect against Staphylococcus aureus (n=20/20) and Enterococcus faecalis (n=13/18), and meanwhile exhibited a mostly additive effect against Staphylococcus intermedius (n=12/20), Streptococcus agalactiae (n=10/10), Streptococcus dysgalactiae (n=18/18), and Escherichia coli (n=14/18). There were no indifferent or antagonistic effects between CEZ and nisin A. In the time-kill assay, the CEZ-nisin A combination at 0.5 × or 1 × minimum inhibitory concentration exhibited synergistic reduction of bacterial growth by over 3 log10 colony forming units per ml relative to that observed with either antimicrobial substance alone. These results suggest that the CEZ-nisin A combination can be used for developing an intramammary infusion for mastitis treatment, with lower antibiotic concentrations than normal.

The prevalence and risk factors of school absenteeism due to premenstrual disorders in Japanese high school students-a school-based cross-sectional study.

BACKGROUND: Premenstrual disorders such as premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD) interfere with the daily lives of adolescents. The causes of PMS and PMDD are unknown, but lifestyle habits, such as regular exercise and taste preference are known to be associated. This study was conducted to investigate how premenstrual symptoms affect the school life in Japanese high school students and whether there was a risk factor for school absenteeism that is dependent on the types of premenstrual symptoms or lifestyle habits. METHODS: A school-based survey was conducted in Sendai, an industrial city in Japan. A total of 901 girls aged 15-19 with regular menstrual cycles were assessed using the self-reporting premenstrual symptoms questionnaire (PSQ) and questions regarding school absence, taste preference, and exercise. We classified the girls into 'no/mild PMS', 'moderate-to-severe PMS' and 'PMDD' according to the PSQ. The girls were classified into the 'absent' group if they were absent for more than 1 day per month. We used multivariate logistic analysis to examine the risk factors for school absenteeism. RESULTS: The rates of 'moderate-to-severe PMS' and 'PMDD' were 9.9 and 3.1 %, respectively. A total of 107 girls (11.9 %) were classified into the 'absent' group. Significant differences were observed in the prevalence of all premenstrual symptoms (p < 0.001), 'age' (p < 0.001), 'a preference for salty food' (p = 0.001), and 'lack of regular exercise' (p = 0.03) between the 'absent' and 'non-absent' groups. Multivariate analysis revealed that premenstrual symptoms such as 'insomnia or hypersomnia' (odds ratio [OR] 2.27, 95 % confidence interval [CI]: 1.46-4.17) and 'physical symptoms' (OR 2.24, 95 % CI: 1.37-3.66), 'reduced social life activities' (OR 2.71, 95 % CI 1.31-5.59), and 'a preference for salty food' (OR 1.89, 95 % CI: 1.20-2.98) were risk factors for school absenteeism. CONCLUSIONS: One in nine Japanese female high school students were absent from school due to premenstrual symptoms. Physical premenstrual symptoms and lifestyles, such as a preference for salty food and a lack of regular exercise, were identified as risk factors for school absenteeism.

Identification of Lactococcus-Specific Bacteriocins Produced by Lactococcal Isolates, and the Discovery of a Novel Bacteriocin, Lactococcin Z.

Lactic acid bacteria that produce Lactococcus-specific bacteriocins were isolated and identified as Lactococcus lactis from fresh corn or lettuce. Among them, four isolates were identified as lactococcin Q producers. Seven isolates showed antimicrobial activity against a lactococcin Q producer, L. lactis QU 4, as well as against nisin Z and lacticin Q producers belonging to L. lactis. Strain QU 7 was selected as a standard strain and showed no cross-immunity to lactococcin Q or other lactococcal bacteriocins. The bacteriocin produced by strain QU 7 was purified in three chromatographic steps, and its molecular mass was determined to be 5041.35 Da. The amino acid sequence analysis revealed that it is a novel class IId bacteriocin, referred to as lactococcin Z. It consisted of 45 amino acid residues. The lczA gene encoding the prepeptide of lactococcin Z showed homology to lactococcins A, B, and M. Thus, this report demonstrates a new example of Lactococcus-specific bacteriocins.

Relationship between dysmenorrhea and posttraumatic stress disorder in Japanese high school students 9 months after the Great East Japan Earthquake.

STUDY OBJECTIVE: To determine the relationship between dysmenorrhea and posttraumatic stress disorder (PTSD) among Japanese adolescent girls 9 months after the Great East Japan Earthquake. DESIGN: Cross-sectional study. SETTING: Two high schools in Sendai, the largest city in northeastern Japan. PARTICIPANTS: 1489 female adolescents aged between 15 and 18 years. MAIN OUTCOME MEASURES: Impact of Event Scale-Revised (IES-R), intensity of menstrual pain. RESULTS: The intensity of menstrual pain increased according to the comorbidity of PTSD (P < .001). The IES-R subscale and total scores significantly increased according to the severity of menstrual pain. CONCLUSIONS: This study showed a significant association between natural disaster-induced PTSD and the severity of dysmenorrhea.

Structural analysis and characterization of lacticin Q, a novel bacteriocin belonging to a new family of unmodified bacteriocins of gram-positive bacteria.

Lactococcus lactis QU 5 isolated from corn produces a novel bacteriocin, termed lacticin Q. By acetone precipitation, cation-exchange chromatography, and reverse-phase high-performance liquid chromatography, lacticin Q was purified from the culture supernatant of this organism, and its molecular mass was determined to be 5,926.50 Da by mass spectrometry. Subsequent analyses of amino acid and DNA sequences revealed that lacticin Q comprised 53 amino acid residues and that its N-terminal methionine residue was formylated. In contrast to most bacteriocins produced by gram-positive bacteria, lacticin Q had no N-terminal extensions such as leader or signal sequences. It showed 66% and 48% identity to AucA, a hypothetical protein from Corynebacterium jeikeium plasmid pA501, and aureocin A53, a bacteriocin from Staphylococcus aureus A53, respectively. The characteristics of lacticin Q were determined and compared to those of nisin A. Similar to nisin A, lacticin Q exhibited antibacterial activity against various gram-positive bacteria. Lacticin Q was very stable against heat treatment and changes in pH; in particular, it was stable at alkaline pH values, while nisin A was inactivated. Moreover, lacticin Q induced ATP efflux from a Listeria sp. strain in a shorter time and at a lower concentration than nisin A, indicating that the former affected indicator cells in a different manner from that of the latter. The results described here clarified the fact that lacticin Q belongs to a new family of class II bacteriocins and that it can be employed as an alternative to or in combination with nisin A.

Lactococcin Q, a novel two-peptide bacteriocin produced by Lactococcus lactis QU 4.

A bacteriocin-producing strain, Lactococcus lactis QU 4, was isolated from corn. The bacteriocin, termed lactococcin Q, showed antibacterial activity only against L. lactis strains among a wide range of gram-positive indicator strains tested. Lactococcin Q was purified by acetone precipitation, cation exchange chromatography, and reverse-phase chromatography. Lactococcin Q consisted of two peptides, alpha and beta, whose molecular masses were determined to be 4,260.43 Da and 4,018.36 Da, respectively. Amino acid and DNA sequencing analyses revealed that lactococcin Q was a novel two-peptide bacteriocin, homologous to lactococcin G. Comparative study using chemically synthesized lactococcin Q (Qalpha plus Qbeta) and lactococcin G (Galpha plus Gbeta) clarified that hybrid combinations (Qalpha plus Gbeta and Galpha plus Qbeta) as well as original combinations showed antibacterial activity, although each single peptide showed no significant activity. These four pairs of lactococcin peptides acted synergistically at a 1:1 molar ratio and exhibited identical antibacterial spectra but differed in MIC. The MIC of Qalpha plus Gbeta was 32 times higher than that of Qalpha plus Qbeta, suggesting that the difference in beta peptides was important for the intensity of antibacterial activity.

Dbp9p, a member of the DEAD box protein family, exhibits DNA helicase activity.

The yeast Dbp9p is a member of the DEAD box family of RNA helicases, which are thought to be involved in RNA metabolism. Dbp9p seems to function in ribosomal RNA biogenesis, but it has not been biochemically characterized. To analyze the enzymatic characteristics of the protein, we expressed a recombinant Dbp9p in Escherichia coli and purified it to homogeneity. The purified protein exhibited RNA unwinding and binding activity in the absence of NTP, and this activity was abolished by a mutation in the RNA-binding domain. We then characterized the ATPase activity of Dbp9p with respect to cofactor specificity; the activity was found to be severely inhibited by yeast total RNA and moderately inhibited by poly(U), poly(A), and poly(C) but to be stimulated by yeast genomic DNA and salmon sperm DNA. In addition, Dbp9p exhibited DNA-DNA and DNA-RNA helicase activity in the presence of ATP. These results indicate that Dbp9p has biochemical characteristics unique among DEAD box proteins.