Comparing catch-up vaccination programs based on analysis of 2012-13 rubella outbreak in Kawasaki City, Japan

During the 2012–13 rubella outbreak in Japan, local governments implemented subsidy programs for catch-up vaccination to mitigate the rubella outbreak and prevent congenital rubella syndrome (CRS). In most local governments, to prevent CRS, eligible persons of the subsidy program were women who were planning to have a child and men who were partners of pregnant women. On the other hand, in Kawasaki City, unimmunized men aged 23–39 years were additionally included in the eligible persons, because they were included in an unimmunized men group resulting from the historical transition of the national routine vaccination in Japan. The number of rubella cases in the city decreased earlier than that in the whole Japan. First, in order to estimate the effect of the catch-up vaccination campaign in Kawasaki City on the epidemic outcome, we performed numerical simulations with a Susceptible-Vaccinated-Exposed-Infectious-Recovered (SVEIR) model incorporating real data. The result indicated that the catch-up vaccination campaign showed a beneficial impact on the early decay of the rubella cases. Second, we numerically compared several different implementation strategies of catch-up vaccinations under a fixed amount of total vaccinations. As a result, we found that early and intensive vaccinations are vital for significant reduction in the number of rubella cases and CRS occurrences. Our study suggests that mathematical models with epidemiological and social data can contribute to identifying the most effective vaccination strategy.

Effect of Lithium Compound Addition on the Dehydration and Hydration of Calcium Hydroxide as a Chemical Heat Storage Material

Many studies on calcium hydroxide [Ca(OH)₂] as a chemical heat storage material have been conducted. Generally, calcium hydroxide undergoes a dehydration reaction (heat storage operation) efficiently at about 400 °C or higher. In this study, we aimed to lower the dehydration reaction temperature and increase the dehydration reaction rate to expand the applicability of calcium hydroxide as a chemical heat storage material. For the purpose of improving the dehydration reactivity, calcium hydroxide with added lithium compounds was prepared, and the dehydration/hydration reactivities were evaluated. From the results, it was confirmed that the addition of the lithium compounds lowered the dehydration reaction temperature of calcium hydroxide and enhanced the reaction rate. The dehydration reaction of Ca(OH)₂ with Li compounds proceeded efficiently even at 350 °C, and the reversibility of the dehydration/hydration reaction was confirmed. The reason for the improvement of the calcium hydroxide dehydration reactivity upon the addition of a lithium compound was examined from the viewpoint of its crystal structure. It was presumed that when lithium ions enter the calcium hydroxide crystals, the crystals became fragile and the dehydration reaction was accelerated.

[Evaluation of real-time surveillance of influenza incidence in Kawasaki City by comparison using the National Epidemiological Surveillance of Infectious Diseases]

Objectives　In Japan, nationwide data of the incidence of infectious diseases have been collected via the National Epidemiological Surveillance of Infectious Diseases (NESID) since 1981. In addition, since March 2014, Kawasaki City has operated its own real-time surveillance (RTS) system to collect data of the incidence of influenza from medical institutions across the city. This study aimed to describe the characteristics of the RTS system and compare the two surveillance systems to improve measures against infectious diseases in the future.Methods　NESID and RTS data from March 2014 to October 2017 were obtained from the Kawasaki City Institute for Public Health. First, the operating methodologies of the two surveillance systems were compared. Second, RTS data were used to analyze the daily epidemic curve, and then the daily number of influenza cases was converted into weekly data for comparison with NESID data. Pearson's correlation coefficients and 95% confidence intervals (CIs) were calculated. Correlations were also analyzed after data for the last and first weeks of each year were excluded because few hospitals remain open around the New Year holiday, resulting in a disproportionately large number of patients visiting the few institutions that remain open.Results　The NESID relies on data provided by a fixed number of medical institutions determined each fiscal year (mean: 56.0±4.2 institutions), while the number of institutions providing data for the RTS varies daily or monthly. In September 2017, 691 of the 1,032 eligible institutions (67.0%) were registered for the RTS. Pearson's correlation coefficient for the two surveillance systems was 0.975 (95%CI, 0.967-0.981); when data for the last and first week of each year were excluded, it was 0.989 (95%CI 0.986-0.992). In each of the three seasons that were investigated, an increase in the incidence of type A influenza preceded an increase in the incidence of type B influenza.Conclusion　The operating methodologies of the two surveillance systems differed; however, the results identified a strong correlation, confirming the reliability of the RTS. The RTS collects daily data by influenza type; therefore, it detects epidemic onsets at an earlier stage, facilitating more detailed epidemiological analysis, compared with that of the NESID. It is necessary to understand differences in the characteristics between two surveillance systems when we analyze influenza surveillance data.

Clinical characteristics of lupus enteritis in Japanese patients: the large intestine-dominant type has features of intestinal pseudo-obstruction

This study was performed to investigate the clinical characteristics of lupus enteritis in Japanese patients with systemic lupus erythematosus (SLE). A total of 481 patients with SLE admitted to our hospital between 2001 and 2015 were retrospectively reviewed. Diagnosis of lupus enteritis was based on the following three criteria: (1) abdominal symptoms, (2) diffuse long-segment bowel thickening and (3) a requirement for glucocorticoid therapy. Lupus enteritis was identified in 17 patients (3.5%) and there were two distinct types: small intestine-dominant and large intestine-dominant. Significant differences between the two types were noted with respect to the age, frequency of biopsy-proven lupus nephritis, frequency of rectal involvement, maximum bowel wall thickness, and requirement for steroid pulse therapy. Among patients with large intestine-dominant lupus enteritis, 60% had extra-intestinal symptoms (hydroureter, bladder wall thickening, and bile duct dilatation) that are known complications of intestinal pseudo-obstruction. Two patients with large intestine-dominant lupus enteritis developed intestinal pseudo-obstruction either before or after diagnosis of lupus enteritis. Five patients (29%) developed recurrence during a median observation period of 7.2 years (1.4-14.4 years). In conclusion, large intestine-dominant lupus enteritis resembles intestinal pseudo-obstruction and these two diseases may have a common pathogenesis.

Ultrasonography of Thymoma with Pathologic Correlation

Preoperative ultrasonograms of 11 surgically proved thymomas and ex vivo ultrasonograms of 3 resected specimens were compared with pathologic findings of resected specimens. Among 11 thymomas 7 appeared solid, 3 were solid with several cystic regions, and the remaining one was unilocular cystic in appearance. Cystic regions on ultrasonograms corresponded to cystic changes on pathologic specimens. Six malignant thymomas showed a typical lacy appearance on ultrasonograms, which corresponded to the lobulated configuration separated by fibrous septa shown on the pathologic specimens.

Influence of Microbubbles on Free Radical Generation by Ultrasound in Aqueous Solution: Dependence of Ultrasound Frequency

The influence of microbubbles on sonochemical efficiencies has been investigated under 28, 45, and 100 kHz ultrasound irradiation. For the 28 and 100 kHz ultrasound frequencies, microbubbles suppressed the I3(-) formation from KI solution as well as the 7-hydroxycoumarin formation from coumarin solution caused by the ultrasonic irradiation. On the other hand, for the 45 kHz ultrasound frequency, microbubbles enhanced the I3(-) formation from KI solution as well as 7-hydroxycoumarin formation from coumarin solution caused by the ultrasonic irradiation. Detection of H2O2 after the irradiation of ultrasound in the presence or absence of microbubbles was also performed, and it was found that H2O2 formation was enhanced only when microbubbles were introduced under the 45 kHz ultrasonic irradiation, which was in good agreement with the results of KI oxidation dosimetry measurements and of coumarin fluorescent probe measurements. Based on these present results, plausible mechanisms that explain the dependence of the ultrasound frequency on the enhancement and suppression of free radical formation in the presence of MBs were proposed.

Design and application of group-specific oligonucleotide probes for detecting and monitoring mouse clostridia

Clostridia dominate the rodent intestinal bacterial community and play an important role in physiological functions of the host. However, their ecology and diversity are still unclear. In our previous report, we showed that phylogenetically novel groups of clostridia inhabit the mouse intestine and contribute to the normalization of germfree mice. In this study, five new oligonucleotide probes were designed and applied to detect these clostridial groups that are essential for the normalization of germfree mice. Faecal microbiota of conventional mouse strains and specific pathogen-free mice from different breeding colonies were analysed by fluorescence in situ hybridization using these five probes. Our results showed that the composition of clostridia differed among mouse strains and also among mouse groups of the same inbred strain from different breeding colonies. These five new probes for mouse clostridia were able to detect the difference in clostridial diversity in each mouse group. In addition to Clostridium, we also analysed Bacteroides and Lactobacillus using previously described probes and the number or the frequency of occurrence of Bacteroides was shown to be different among mouse groups analysed. The oligonucleotide probe set including our newly developed and previously described probes used in this study can be applied to monitoring of significant groups of mouse intestinal microbiota.

Abundance of Virus-Sized Non-DNase-Digestible DNA (Coated DNA) in Eutrophic Seawater

Total DNA concentration in 0.2-mum-pore-size Nuclepore filter filtrates (<0.2-mum fraction) of Tokyo Bay water was estimated to be 9 to 19 ng/ml by an immunochemical quantification method. Almost 90% of the DNA in the <0.2-mum fraction was found in the size fractions larger than 3.0 x 10 Da and 0.03 mum, and most was not susceptible to DNase digestion, that is, consisted of non-DNase-digestible DNA (coated DNA). A significant amount of DNA was obtained from the <0.2-mum fraction of the seawater by three different methods: polyethylene glycol precipitation, direct ethanol precipitation, and ultrafilter concentration. Gel electrophoresis analysis of the isolated DNAs showed that they consisted mainly of coated DNAs with a similar molecular sizes (20 to 30 kb [1.3 x 10 to 2.0 x 10 Da). The abundance of the ultramicron virus-sized coated DNA in natural seawater suggests that these DNA-rich particles can be attributed to marine DNA virus assemblages and that they may be a significant phosphorus reservoir in the environment.

Activities and distribution of methanogenic and methane-oxidizing microbes in marine sediments from the Cascadia Margin

We investigated methane production and oxidation and the depth distribution and phylogenetic affiliation of a functional gene for methanogenesis, methyl coenzyme M reductase subunit A (mcrA), at two sites of the Integrated Ocean Drilling Program Expedition 311. These sites, U1327 and U1329, are respectively inside and outside the area of gas hydrate distribution on the Cascadia Margin. Radiotracer experiments using (14)C-labelled substrates indicated high potential methane production rates in hydrate-bearing sediments [128-223 m below seafloor (mbsf)] at U1327 and in sediments between 70 and 140 mbsf at U1329. Tracer-free experiments indicated high cumulative methane production in sediments within and below the gas hydrate layer at U1327 and in sediments below 70 mbsf at U1329. Stable tracer experiments using (13)C-labelled methane showed high potential methane oxidation rates in near-surface sediments and in sediments deeper than 100 mbsf at both sites. Results of polymerase chain reaction amplification of mcrA in DNA were mostly consistent with methane production: relatively strong mcrA amplification was detected in the gas hydrate-bearing sediments at U1327, whereas at U1329, it was mainly detected in sediments from around the bottom-simulating reflector (126 mbsf). Phylogenetic analysis of mcrA separated it into four phylotype clusters: two clusters of methanogens, Methanosarcinales and Methanobacteriales, and two clusters of anaerobic methanotrophic archaea, ANME-I and ANME-II groups, supporting the activity measurement results. These results reveal that in situ methanogenesis in deep sediments probably contributes to gas hydrate formation and are inconsistent with the geochemical model that microbial methane currently being generated in shallow sediments migrates downward and contributes to the hydrate formation. At Site U1327, gas hydrates occurred in turbidite sediments, which were absent at Site U1329, suggesting that a geological setting suitable for a gas hydrate reservoir is more important for the accumulation of gas hydrate than microbiological properties.

16S rRNA gene sequence-based analysis of clostridia related to conversion of germfree mice to the normal state

AIMS

To determine phylogenetic groups of clostridia inhabiting the mouse intestine that are essential for normalization of germfree (GF) mice.

METHODS AND RESULTS

Using both the culture method and cloning, clostridia inhabiting the mouse intestine were isolated, and phylogenetic analysis based on 16S rRNA gene sequences was carried out. As a result, the isolates were found to have novel sequences, and no isolate was determined to be identical to previously known identified clostridia. Although the taxonomy of mouse intestinal clostridia was complex, many of them belonged to Clostridium clusters XIVa and IV in conventional (CV) and limited flora mice and ex-germfree mice administered chloroform-treated CV mouse faeces. The clostridia that belonged to cluster XIVa were most often present and showed the highest diversity.

CONCLUSIONS

Clostridia belonging clusters XIVa and IV are dominant in the mouse intestine as in other gut ecosystems. The novel groups in these clusters are essential for normalization of GF mice.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results of this study can be applied in the strict control of mouse intestinal microbiota and will provide important information for normalization of GF mice and also for research on microbiology of the mouse intestine.

Study of Association Between Hypertensive Disorders of Pregnancy and the Human Coagulation Factor XI Gene

OBJECTIVE

Hypertensive disorders of pregnancy (HDP) are among the most common and serious complications of pregnancy. Persuasive evidence implicaties genetic factors in the genesis of HDP. The aim of the present study was to assess the association between single-nucleotide polymorphisms (SNPs) in the human coagulation factor XI (F11) gene and HDP, by conducting a haplotype-based case-control study.

METHODS

We chose 3 SNPs (rs925453, rs925451, and rs12500151) in the human F11 gene as genetic markers. We then conducted an association study with 77 HDP patients and 154 age-matched non-HDP subjects.

RESULTS

The frequency of rs925453 genotypes significantly differed between the two groups. The frequency of the T-G-G haplotype was significantly higher in the HDP group than in the non-HDP group (p = 0.0002).

CONCLUSIONS

The T allele of rs925453 and the T-G-G haplotype appear to be useful genetic markers of HDP.

Association Study Between the Human Renin Gene and Preeclampsia

OBJECTIVE

We recently reported on a missense mutation in exon 9 of the human renin gene (G1051A) that may affect the functioning of this enzyme, and is associated with essential hypertension. The aim of the present study is to assess the association between the genotypes of this missense mutation in the renin gene and preeclampsia (PE) via a case-control study.

METHODS

DNA was extracted from peripheral blood leukocytes, and genotyping of G1051A was performed in 117 PE patients and in 171 non-PE controls.

RESULTS

The frequency of genotypes for G1051A was not significantly different between the two groups. The frequency of the A1051 allele was also not significantly different between PE patients (52.6%) and non-PE controls (50.6%).

CONCLUSIONS

The missense mutation G1051A in the human renin gene is not associated with PE.

Age-related three-dimensional morphological changes in rat motoneurons innervating diaphragm and longissimus muscles

We investigated age-related morphological changes of rat motoneurons innervating diaphragm muscle (DI-MN) and lumber longissimus muscle (LL-MN) in which quite different activation patterns exist. In young (2-4 months) and old (24-26 months) rats, the motoneurons innervating both muscles were labelled retrogradely by intramuscular injection of cholera toxin B subunit. After a 4-day survival, horizontal slices of the spinal cord were processed with immunohistochemical staining (first antibody to cholera toxin B subunit and second antibody with Cy3) and observed with a confocal microscope. Three-dimensional reconstruction of labelled motoneurons was performed to examine soma and dendrite morphology. As compared to the soma volume in young rats, significantly smaller values were found in old rats in both motoneurons and the degrees of decline were 16.1% in DI-MN and 20.3% in LL-MN. Significant decreases in the thickness of primary dendrites were also found in both motoneurons, and the degrees of decline were 17.5% in DI-MN and 22.3% in LL-MN. Smaller changes were found in DI-MN than in LL-MN, indicating the possibility that increased activation by central drives can attenuate age-related morphological changes of the motor system in the spinal cord.

Spatial and temporal distribution of the vibrionaceae in coastal waters of Hawaii, Australia, and France

Relatively little is known about large-scale spatial and temporal fluctuations in bacterioplankton, especially within the bacterial families. In general, however, a number of abiotic factors (namely, nutrients and temperature) appear to influence distribution. Community dynamics within the Vibrionaceae are of particular interest to biologists because this family contains a number of important pathogenic, commensal, and mutualist species. Of special interest to this study is the mutualism between sepiolid squids and Vibrio fischeri and Vibrio logei, where host squids seed surrounding waters daily with their bacterial partners. This study seeks to examine the spatial and temporal distribution of the Vibrionaceae with respect to V. fischeri and V. logei in Hawaii, southeastern Australia, and southern France sampling sites. In particular, we examine how the presence of sepiolid squid hosts influences community population structure within the Vibrionaceae. We found that abiotic (temperature) and biotic (host distribution) factors both influence population dynamics. In Hawaii, three sites within squid host habitat contained communities of Vibrionaceae with higher proportions of V. fischeri. In Australia, V. fischeri numbers at host collection sites were greater than other populations; however, there were no spatial or temporal patterns seen at other sample sites. In France, host presence did not appear to influence Vibrio communities, although sampled populations were significantly greater in the winter than summer sampling periods. Results of this study demonstrate the importance of understanding how both abiotic and biotic factors interact to influence bacterial community structure within the Vibrionaceae.

Determinants for Prediction of Malignant Potential by Metalloproteinase:E-Cadherin Ratio in Prostate Core Needle Biopsy

According to a good correlation between in situ hybridization-based metalloproteinase-2/9:E-cadherin ratio (MER) and the pathological stage of prostate cancer, we set the cutoff line of MER at 6.0 (MER>6) to distinguish between organ-confined (pT2) and advanced diseases (pT3a-b/N1). In this study, we looked at the factors affecting MER and leading to a misprediction of the pathological stage. We examined MER in 39 paired specimens of prostate core needle biopsy and prostatectomy from the same patient and compared these MERs. In 34 (87%) of 39 cases, the MER of biopsy was correlated with the final pathological stage (pT2 vs. pT3a-b/N1). MER ranges in pT3a-b/N1 cancer were significantly wider than those in pT2 cancer (p < 0.01). The number of MER>6 fields in Gleason score 8-9 cancer was larger than that in Gleason score 7 cancer (p < 0.0001). In 5 cases where there was a failure to distinguish pT2 from pT3a-b/N1, the misdiagnosis was significantly associated with a small number of biopsies (4 or 6 specimens; p = 0.0469), a small amount of tumor tissue in biopsy specimens (less than 5 mm; p = 0.0492), and a wide MER range (more than 5.0; high intratumoral heterogeneity; p = 0.0202). Considering these factors increases the usefulness of preoperative prediction of the final pathological stage by MER in prostate cancer.

pH-sensing nano-crystals of carbonate apatite: effects on intracellular delivery and release of DNA for efficient expression into mammalian cells

Two unique and fascinating properties of carbonate apatite which are well-known in hard tissue engineering, have been unveiled, for the first time, for the development of the simplest, but most efficient non-viral gene delivery device - ability of preventing the growth of crystals needed for high frequency DNA transfer across a plasma membrane and a fast dissolution rate for effective release of DNA during endosomal acidification, leading to a remarkably high transgene expression (5 to 100-fold) in mammalian cells compared to the widely used transfecting agents. Moreover, by modulating the crystal dissolution rate of carbonate apatite through incorporation of fluoride or strontium into it, transfection activity could be dramatically controlled, thus shedding light on a new barrier in the non-viral route, which was overlooked so far. Thus we have developed an innovative technology with significant insights, that would come as a promising tool for both basic research laboratories and clinical settings.

Relationship between the Thromboxane A2 Receptor Gene and Susceptibility to Cerebral Infarction

The risk of cerebral infarction (CI) in an individual is dependent on the interplay between genetic risk factors and environmental influences. Binding of thromboxane A2 (TXA2) to its receptor (TP) modulates thrombosis/hemostasis and plays a significant role in the pathogenesis of CI. The aim of the present study was to investigate the relationship between human TP gene single nucleotide polymorphisms (SNPs) and haplotypes and CI in a Japanese population. A genetic association study was performed in 194 CI patients and 365 non-CI subjects by specifically characterizing 6 SNPs in the human TP gene (rs2271875, rs768963, rs2238634, rs11085026, rs4523 and rs4806942). Analysis demonstrated that there were significant differences in the overall distribution of genotypes and dominant or recessive models of rs2271875 and rs768963 between the CI and the non-CI groups. Multiple logistic regression analysis revealed that the C allele of rs768963 was significantly associated with CI (p = 0.029), even after adjusting for confounding factors (odds ratio: 2.41). Further, the C-T-C haplotype of rs768963-rs2238634-rs4806942 was significantly more frequent in the CI group (23.0%) than in the non-CI group (17.7%). These results suggest that specific SNPs and haplotypes may have utility as genetic markers for the risk of CI and that TP or a neighboring gene is associated with the increased susceptibility to CI.

Association study using single nucleotide polymorphisms in the estrogen receptor beta (ESR2) gene for preeclampsia

The pathophysiology of preeclampsia (PE) remains uncertain despite many research efforts. Actual hypotheses seek to explain the vascular damage that characterizes the disease. Recently, it was reported that the mouse disrupted estrogen receptor beta (ESR2) gene was associated with abnormal vascular function and hypertension. Moreover, some investigators have reported that subjects with a family history of hypertension have a statistically significant increased risk for PE. Thus, it is thought that the pathophysiology of PE overlaps that for hypertension. The aim of the present study was to investigate the relationships between single nucleotide polymorphisms (SNPs) in the human ESR2 gene and PE in Japanese subjects, and to assess the involvement of a family history of hypertension in these relationships. Based on a database search on the web site of the National Center of Biotechnology Information (NCBI), we chose four SNPs in the human ESR2 gene, and performed an association study in 84 PE patients and 160 age-matched non-PE subjects. The overall distribution in each SNP did not differ significantly between the two groups. However, after dividing the groups into subjects with and without a family history of hypertension, the allelic distribution of one of the SNPs (rs928554) revealed a positive association. Thus, a possible mutation linked to a SNP may prescribe a genetic predisposition for patients with a family history of hypertension in PE.

[A case of synchronous double cancer responding to UFT--dermoid cyst with secondary malignant transformation and uterine endometrial adenocarcinoma]

We report here a case of synchronous dermoid cyst with secondary malignant tumor and uterine endometrial adenocarcinoma that responded to UFT. A 35-year-old female complained of abdominal fullness and visited our hospital. She had an abdominal mass which was newborn-head size. We performed right salpingo-oophorectomy and partial omentectomy. The pathological findings were dermoid cyst with secondary malignant transformation. After the operation she had underwent cyclic chemotherapy with CDDP, CPA, THP and 5-FU. After three cycles of chemotherapy, a uterine recurrence was suspected from her uterine endocervical smear test. Then we performed a second operation, but radical surgery was impossible due to the presence of multiple metastases to pelvic lymph nodes. The pathological findings were primary uterine endometrial adenocarcinoma, not metastasis from dermoid cyst with secondary malignant tumor. After the second operation, she was treated with oral UFT (400 mg/day), as she refused chemotherapy and radiotherapy. Two months after the start of UFT, the tumor markers were reduced remarkably, and the patient maintained good QOL throughout the treatment without serious adverse events. We conclude that UFT might be benefical in the treatment of advanced gynecologic cancer.

Brain-derived neurotrophic factor increases inhibitory synapses, revealed in solitary neurons cultured from rat visual cortex

To elucidate chronic actions of brain-derived neurotrophic factor (BDNF) on GABAergic synapses, we examined effects of a long-term application of BDNF for 10-15 days on autapses (synapses) of solitary GABAergic neurons cultured from rat visual cortex. Solitary neuron preparations were used to exclude a possible contamination of BDNF actions on excitatory neurons in dissociated neuron culture or slice preparations. Neurons were confirmed to be GABAergic pharmacologically with bicuculline, a selective antagonist for GABAA receptors and immunocytochemically with antibody against glutamic acid decarboxylase 65, a GABA synthesizing enzyme. To evaluate GABAergic synaptic function, evoked and/or miniature inhibitory postsynaptic currents (IPSCs) were recorded in the whole-cell voltage-clamp mode. The treatment with BDNF at a concentration of 100 ng/ml enhanced the amplitude of evoked IPSCs and the frequency of miniature IPSCs. In contrast, BDNF did not have a detectable effect on the amplitude of miniature IPSCs and the paired pulse ratio of IPSCs evoked by two, successive activations. To evaluate morphological changes, neurons were immunocytochemically stained with antibodies against microtubule-associated protein 2, to visualize somatodendritic region and synapsin I, to visualize presynaptic sites. The quantitative analysis indicated that BDNF increased the area of soma, the numbers of primary dendrites and dendritic branching points, the total length of dendrites and the number of synaptic sites. Such an action of BDNF was seen in both subgroups of GABAergic neurons, parvalbumin-positive and -negative neurons. To visualize functionally active presynaptic sites, neurons were stained with a styryl dye, FM1-43. BDNF increased the number of stained sites that was correlated with the frequency of miniature IPSCs. These results suggest that the chronic treatment with BDNF promotes dendritic and synaptic development of GABAergic neurons in visual cortex.

Dynamics of microbial populations and strong selection for Cycloclasticus pugetii following the Nakhodka oil spill

Microbial population changes were monitored immediately after the Nakhodka oil spill accident in January 1997 at the heavily oil-contaminated Mikuni coast along the Sea of Japan. The total cell number was almost stable for one year at 2-5 x 10(5) cells mL(-1), while the relative occurrence of culturable heterotrophs and degraders of oil components such as C-heavy oil, kerosene, and n-tetradecane varied, showing a maximum (>50% of the total) immediately following the accident. Gene amplification and phylogenetic analysis of a dilution culture using C-heavy oil as the sole carbon and energy source revealed that one of the predominant oil degraders at the oil-contaminated coast in 2 weeks after the accident closely resembled the aromatic hydrocarbon decomposer Cycloclasticus pugetii. Microbial community composition in oil-contaminated seawater was estimated at the molecular level using newly developed oligonucleotide probes, probe wash-off curve estimation, and quantitative fluorescence dot-blot hybridization techniques. At two different oil-polluted sites, harbor and intertidal regions, the C. pugetii group was estimated to make up 23-25% of the total Bacteria population, followed by the aliphatic hydrocarbon decomposer Alcanivorax borkumensis, which formed 4-7% of the Bacteria. In incubation experiments using floated oil slick and indigenous microbes collected at the harbor, oil degradation activities were enhanced by the addition of both organic and inorganic nutrients. Significant decreases were found in aromatic and aliphatic hydrocarbon fractions: 54-60% and 22-24% in 2 weeks to 68-77% and 23-32% in 2 months, respectively.

Triplex formation using ODN conjugates with polycation comb-type copolymer

Polycation comb-type copolymer that is composed of polylysine backbone and dextran side chains (PLL-g-Dex) has previously been shown to stabilize duplex and triplex DNAs quite effectively. In this study, we have conjugated PLL-g-Dex with oligonucleotides (ODN) aiming to increase the triplex stabilizing efficiency of the copolymer. Here we have demonstrated that the copolymer-TFO conjugates selectively stabilize triplex DNA. Also its potential to form triplex DNA was found to be greater than PLL-g-Dex/ODN mixture.

Acceleration of DNA strand exchange by polycation comb-type copolymer

The accelerating effect of cationic substances on DNA strand exchange reaction between 20 bp DNA duplex and its complementary single strand was studied. A comb-type polycationic copolymer which is composed of poly (L-lysine) backbone and dextran graft chain (PLL-g-Dex) and known to stabilize triplex DNA expedites the strand exchange reaction under physiological relevant conditions. Electrostatically small excess of the copolymer increased DNA strand exchange rate by 300-fold while large excess of spermine or cethyltrimethylammonium bromide, cationic detergent known to promote markedly hybridization of complementary DNA strands, showed slight effect. It should be noted that the copolymer promotes the strand exchange reaction while it stabilizes double stranded DNA.

Synergistic stabilization of triplex by combination of comb-type cationic copolymer and oligo-N3'-->P5' phosphoramidates

In the present study, we describe rapid formation of stable pyrimidine motif triplex at physiological pH. The triplex formation was achieved by the synergistic effect of poly(L-lysine)-graft-dextran (PLL-g-Dex) copolymer and N3'-->P5' phosphoramidate (PN) backbone modification of triplex-forming oligonucleotide (TFO). Either the PLL-g-Dex copolymer or the PN modification alone increased the binding constant by nearly two orders of magnitude for the triplex formation at neutral pH. The combination of both stabilizing factors that was the triplex formation with the PN TFO in the presence of the copolymer increased the binding constant by nearly four orders of magnitude. The kinetic study indicated that the copolymer increased the association rate constant, whereas the PN modification decreased the dissociation rate constant. No negative interference between these stabilizing effects was observed. The kinetically orchestrated effects in which the copolymer and the PN TFO contribute to distinct ingredients in triplex equilibrium achieved the rapid formation of the stable triplex.

Protein/oligonucleotide conjugates as a cell specific PNA carrier

We have focused on proteineus ligand conjugate with oligonucleotides (ODNs) as a cell-specific delivery vector for peptide nucleic acids (PNAs). Asialofetuin (AF), a hepatocyte-specific proteineus ligand, was conjugated with ODNs that served as binding sites for PNAs. Succinimidyl-transe-4(N-maleimidylmethyl)-cyclohexane-1-carboxylate (SMCC) modified AF was coupled with 5'-thiolated oligodeoxynucleotide (HS-ODN). The resulting conjugate held PNAs with sequence-specific manner. The PNA/DNA conjugate complex has resistance against nucleases in serum. The efficient release of PNA from the complex was observed when the complex was made in contact with a target nucleotide. PNA uptake to hepatocytes was greatly enhanced when hepatocytes was incubated with PNA/conjugate complex. Free AF thoroughly inhibited PNA uptake with the conjugate, evidencing asialoglycoprotein receptor (ASGP-R) mediated endocytosis to be a major-route for the cellular uptake.

Polycation graft copolymers accelerating DNA strand exchange: involvement of ionic interaction

In the previous study (Chem. Eur. J., 7, 176 (2001)) we demonstrated that the comb-type polycationic copolymer (PLL-g-Dex) which is composed of poly (L-lysine) backbone and dextran graft chains expedited the DNA strand exchange reaction. In this study, fluorescence resonance energy transfer (FRET) was employed to explore the copolymer-mediated DNA strand exchange with higher time-resolution. To initiate strand exchange reaction the duplex prepared from 3'-fluorescein isothiocyanate (FITC)--and 5'-carboxytetramethylrhodamine(TAMRA)-labeled complementary DNAs was added to its non-labeled complementary single strand. DNA strand exchange was monitored by observing the recovery of the FITC quenching. More than 20,000 times increase in strand exchange rate at 37 degrees C by the copolymer was estimated. To investigate the accelerating mechanisms of the copolymer, the same reactions but at various ionic strenghts were studied. With increasing ionic strengths the strand exchange rate in the absence of the copolymer increased, suggesting that ionic repulsion among DNAs is unfavorable for the strand exchange to occur. Hence, alleviation of the electrostatic repulsion through interpolyelectrolyte complex formation is probably a role of the copolymer for accelerating the strand exchange reaction.

Cancer history and loss of MSH2 and MLH1 protein expression in patients with endometrial hyperplasia

In order to evaluate the hereditary background of endometrial hyperplasia patients in relation to protein expression of DNA mismatch repair genes, we evaluated 69 patients with endometrial hyperplasia and 18 patients with normal endometrium having both a personal and family history of cancer (two hereditary nonpolypoid colorectal cancer (HNPCC) patients). We obtained personal and family histories of cancer for all patients. MSH2 and MLH1 protein expression was investigated by immunohistochemical methods. In the endometrial hyperplasia patients, 11 had personal histories and 40 had family histories of cancer. Among the 11 endometrial hyperplasia patients with a personal history of cancer, most cancers were breast or colorectal cancers (82%). In the 40 patients with a family history of cancer, colorectal cancer (33%) was the most frequent. The incidence of loss of expression of MSH2 and/or MLH1 protein in endometrial hyperplasia patients with personal (64%) or family (40%) histories was significantly higher than that in patients without such history (no personal: 21% and no family: 10%; P = 0.0035 and 0.0065). No protein loss was detected in any of the cases with normal endometrium having either a personal or family history of cancer. Our results suggest that a portion of endometrial hyperplasia cases having a personal or family history of cancer may belong to HNPCC, and that in these cases, abnormality of the mismatch repair system may be an early event in endometrial carcinogenesis.

Long-term follow-up of hepatitis C virus infection: HLA class II loci influences the natural history of the disease

Hepatitis C virus (HCV) causes various grades of chronic liver disease, ranging from an asymptomatic state to cirrhosis. To assess genetic factors of disease severity, we selected two HCV patient groups according to the following stringent criteria: (i) asymptomatic carrier state (ASC) defined by HCV infection for more than 20 years, normal alanine aminotransferase levels for the past 5 years as well as normal liver histology and/or shape and (ii) liver cirrhosis (LC) as diagnosed by clinical symptoms, liver biopsy and/or ultrasonography. A total of 103 chronically infected Japanese HCV patients (43 ASC and 60 LC) were analyzed. HLA class I and II alleles were established using low resolution DNA typing. HLA-DRB1 and DQB1 genotypes were inferred upon polymerase chain reaction-restriction fragment length polymorphism analysis. Two hundred and one anti-HCV-negative ethnically matched controls were included. The frequencies of DRB1*12 (*1201 and *1202), DQB1*0301 and DRB3*03 alleles were higher in patients with ASC than in those with LC (odds ratio (OR) 11.23, OR 4.25, and OR 3.22, respectively). The frequency of DQB1*0503 were lower in ASC patients compared to LC patients (OR 0.05). No significant differences between groups were observed for age, sex, source of infection, HCV genotype or viral loads. Our findings establish that certain HLA class II alleles strongly influence disease progression following HCV infection.

Inhibition of sequence-specific protein-DNA interaction and restriction endonuclease cleavage via triplex stabilization by poly(L-lysine)-graft-dextran copolymer

Triplex stabilization by poly(L-lysine)-graft-dextran copolymer within a mammalian gene promoter inhibits the DNA binding activity of nuclear proteins from HeLa cells as well as restriction endonuclease cleavage at physiological pH and ionic conditions in vitro. Electrophoretic mobility shift assays using a 30-mer homopurine-homopyrimidine stretch (located between -170 and -141 bp) of rat alpha 1 (I) collagen gene promoter reveal that the copolymer, at its wide range of charge ratio with DNA, stabilizes triplex DNA and enhances triplex-specific inhibition of the protein-DNA interaction. When the triplex-forming region (located between -165 and -146 bp) of the promoter is engineered at the Bam H1 and Pst 1 sites of a plasmid DNA, copolymer-mediated triplex stabilization also remarkably competes endonuclease activity of BamH1. Finally, the triplex-stabilizing efficiency of the copolymer is remarkably higher than that of spermine and benzo[e]pyridoindole. Our results indicate that the copolymer, regardless of the length of the target duplex, stabilizes triplexes for significant inhibition of protein-DNA interaction and endonuclease activity. Since stable triplex formation within a short region out of a long native duplex is a prerequisite to confer the therapeutic potential of antigene strategy, triplex stabilization on a long target duplex and inhibition of nuclear protein-DNA interaction may open the possible in vivo applicability of the copolymer.

Design of polymer materials enhancing nucleotide hybridization for anti-gene technology

Stabilization of nucleotide hybridization is considered important for improving gene therapy using oligonucleotides. We have designed comb-type copolymer consisting of polycation backbone (polylysine) and hydrophilic side chains as a stabilizer for double and triple helical DNAs. The copolymer considerably increased the thermal stability of triple helical structure but did not affect the reversible transition between triple helical and single-stranded DNA. An in vitro electrophoretic mobility shift assay revealed that the copolymer remarkably increased association constants of both Hoogsteen and reverse Hoogsteen-type triple helix formation. Moreover the triple helix-stabilizing efficiency of the copolymer was significantly higher than that of other oligocations like spermine and spermidine. Not only being good DNA triple helix stabilizer, it has also been shown to accelerate DNA strand exchange reactions between double helical DNA and its complementary oligonucleotides. From these, we conclude that this copolymer is capable of either 'stabilizing' or 'activating' DNA hybrids, and may useful for gene targeting employing oligonucleotides.

Overexpression of sigma factor, sigma(B), urges Staphylococcus aureus to thicken the cell wall and to resist beta-lactams

Whole genome sequence analysis revealed that Staphylococcus aureus is provided with only a few sigma factors, including the alternative sigma factor, sigma(B), which is thought to regulate some stress responses. Since the sigB knock-out mutant did not show remarkable phenotypic difference, we constructed the over expressed mutant to examine the role of the sigB. Electron microscopic observation revealed that the mutant showed a variety of cell sizes compared with the parent strain which showed almost homogeneous cell sizes. The mutant delivered a thicker cell wall, about 20% thicker than the parent strain. It became resistant to the lytic activity of lysostaphin and also raised MICs to the cell-wall-affecting antibiotics. The yield of carotenoids and transcripts of pbps were also increased in the mutant. The result suggests that sigB plays some important roles in cell wall synthesis and in resistance to antibiotics that perturb the cell wall synthesis.