A Study of Changes in Uterine Leucocytes During Early Pregnancy in the Mouse-vole Interspesific Pregnancies

Mouse and vole embryos were allogeneically and xenogeneically transferred into pseudopregnant CD-1 and immunodeficient （scid） female mice, and we investigated the distribution of uterine leucocytes cells in the implantation sites on days 5,6,and 7 of pregnancy. Macrophages were evenly distributed in the endometrium on days 5 N 7. Neutrophils were rarely seen on days 5 ~ 7, but lymphoeytes were found throughout the endometrium,often in groups associated with glands or the luminal epithelium. The number of uNK cells increased markedly at the mesometrial triangle and the outer decidual area in the CD-1 uteri containing vole embryos; by contrast, scid uteri having vole embryos showed almost the same number as those having mouse embryos. Mast cells were present in large numbers at the myometrium,but rarely in the decidua in all types of pregnant uteri. Cells at the myometrium were more numerous in xenogeneic than in allogeneic transfer. Many mast cells appeared in the inner decidua where xenogeneically transferred vole embryos were dead and aborted. These results suggest the possibility that uterine leucocytes mediate various immunological events in the mouse-vole interspesific pregnancies.     

A 210-kb segment of tandem repeats and retroelements located between imprinted subdomains of mouse distal chromosome 7.

Mammalian genes subject to genomic imprinting often form clusters and are regulated by long-range mechanisms. The distal imprinted domain of mouse chromosome 7 is orthologous to the Beckwith-Wiedemann syndrome domain in human chromosome 11p15.5 and contains at least 13 imprinted genes. This domain consists of two subdomains, which are respectively regulated by an imprinting center. We here report the finished-quality sequence of a 0.6-Mb region encompassing the more centromeric subdomain. The sequence contains four imprinted genes (Ascl2/Mash2, Ins2, Igf2 and H19) and reveals previously unidentified CpG islands and tandem repeats, which may be features of imprinted genes. Most interestingly, a unique 210-kb segment consisting almost exclusively of tandem repeats and retroelements is identified. This segment, located between Th and Ins2, has features of heterochromatin-forming DNA and is highly methylated at CpG sites. The segment exhibits asynchronous replication on the parental chromosomes, a feature of the imprinted domains. We propose that this repeat segment could serve either as a boundary between the two subdomains or as a target for epigenetic chromatin modifications that regulate imprinting.     

Rhizobium inoculant for soybean [Glycine max (L.) Merrill] in Mekong Delta

Summary Rhizobial inoculation trials were conducted in an acid heavy clay soil in Mekong Delta, Viet Nam, using peat based inoculants produced locally and the commercial granular product of Nitragin CCo., Wisconsin, USA. The pH of these soils ranged from 4.5 to 5.1. Two soybean cultivars, MTD₆ and MTD₁₀, were tested as host plants. There were no significant differences between locally made inoculant treated plants and the uninoculated controls in both cultivars. But, the Nitragin inoculation improved all plant characteristics examined in both cultivars. Grain yields of Nitragin inoculated plants of cultivar MTD₆ and cultivar MTD₁₀ were 6.5 and 5.5 times as much as those of the controls; protein content of grain increased 11 and 16 percent, respectively. Well nodulated plants had shorter life cycles, flowering durations, and days to flowering. The Rhizobium symbiosis resulted in an additional 153 kg grain-N/ha. These studies show that a surface coated commercial multistrain inoculant can be used to successfully grow soybeans in the acid, heavy clay soils of the Mekong Delta.     

Response of rhizobacterial communities in watermelon to infection with cucumber green mottle mosaic virus as revealed by cultivation-dependent RISA

We investigated the rhizobacterial densities and community structure in watermelon rhizosphere under the infection of cucumber green mottle mosaic virus (CGMMV) by artificial inoculation. Rhizobacterial densities and communities were analysed from healthy and infected plants under aerobic and anaerobic culture techniques. The highest total number of aerobic rhizobacteria was counted to be 2.7 × 10⁸ colony forming units per gram (CFU · g^?1) and anaerobic rhizobacteria was to be 3.2 × 10⁶ CFU · g^?1, in healthy and infected plants, respectively. Cultivation-dependent ribosomal intergenic spacer analysis (RISA) was employed for further analysis on the rhizobacterial community structure. By incorporating the relative abundance of amplicons, the per cent similarity was determined by the similarity coefficients based only upon the absence or presence of DNA bands. The cluster analysis of RISA showed that the community structure of aerobic rhizobacteria exhibited 60% similarity between healthy and infected plant. The highest community structure similarity (50% similarity) of anaerobic rhizobacteria occurred between before planting and infected plant.     

RNA-dependent RNA polymerase 6 is required for efficient hpRNA-induced gene silencing in plants

In plants, transgenes with inverted repeats are used to induce efficient RNA silencing, which is also frequently induced by highly transcribed sense transgenes. RNA silencing induced by sense transgenes is dependent on RNA-dependent RNA polymerase 6 (RDR6), which converts single-stranded (ss) RNA into double-stranded (ds) RNA. By contrast, it has been proposed that RNA silencing induced by self-complementary hairpin RNA (hpRNA) does not require RDR6, because the hpRNA can directly fold back on itself to form dsRNA. However, it is unclear whether RDR6 plays a role in hpRNA-induced RNA silencing by amplifying dsRNA to spread RNA silencing within the plant. To address the efficiency of hpRNA-induced RNA silencing in the presence or absence of RDR6, Wild type (WT, Col-0) and rdr6-11 Arabidopsis thaliana lines expressing green fluorescent protein (GFP) were generated and transformed with a GFP-RNA interference (RNAi) construct. Whereas most GFP-RNAi-transformed WT lines exhibited almost complete silencing of GFP expression in the T1 generation, various levels of GFP expression remained among the GFP-RNAi-transformed rdr6-11 lines. Homozygous expression of GFP-RNAi in the T3 generation was not sufficient to induce complete GFP silencing in several rdr6-11 lines. Our results indicate that RDR6 is required for efficient hpRNA-induced RNA silencing in plants.     

An aerobic formate-utilizing bacterium,Cupriavidus sp., isolated from activated sludge of wastewater treatment

An aerobic formate-assimilating bacterium, denoted as strain FAB, was newly isolated from activated sludge of wastewater treatment. Phylogenetic analysis based on 16S rDNA sequence assigned the isolate to the genus Cupriavidus. Scanning electron micrography revealed that this bacterium has a coccal morphology, and from some physiological assays, the bacterium was characterized to be Gram-negative, nitrate-reduction-positive and catalase-positive. In addition to formate, strain FAB was able to utilize fructose, acetate or pyruvate as a preferred carbon source. Compared with a close relative, Cupriavidus necator, our isolate exhibited a greater growth rate on formate under an aerobic condition.     

Pitching Moment Generation in an Insect-Mimicking Flapping-Wing System

Unlike birds, insects lack control surfaces at the tail and hence most insects modify their wing kinematics to produce control forces or moments while flapping their wings. Change of the flapping angle range is one of the ways to modify wing kinematics, resulting in relocation of the mean Aerodynamic force Center （mean AC） and finally creating control moments. In an attempt to mimic this feature, we developed a flapping-wing system that generates a desired pitching moment during flap- ping-wing motion. The system comprises a flapping mechanism that creates a large and symmetric flapping motion in a pair of wings, a flapping angle change mechanism that modifies the flapping angle range, artificial wings, and a power source. From the measured wing kinematics, we have found that the flapping-wing system can properly modify the flapping angle ranges. The measured pitching moments show that the flapping-wing system generates a pitching moment in a desired direction by shifting the flapping angle range. We also demonstrated that the system can in practice change the longitudinal attitude by generating a nonzero pitching moment.     

Risk Factors for Delayed Entrance into Care after Diagnosis among Patients with Late-Stage HIV Disease in Southern Vietnam

Background

We surveyed HIV patients with late-stage disease in southern Vietnam to determine if barriers to access and service quality resulted in late HIV testing and delays from initial diagnosis to entry into HIV care.

Methodology

196 adult patients at public HIV clinics with CD4 counts less than 250 cells/mm3 completed a standardized questionnaire. We used multivariate analysis to determine risk factors for delayed entry into care, defined as >3 months time from diagnosis to registration.

Results

Common reasons for delayed testing were feeling healthy (71%), fear of stigma and discrimination in the community (43%), time conflicts with work or school (31%), did not want to know if infected (30%), and fear of lack of confidentiality (27%). Forty-five percent of participants delayed entry into care with a median CD4 count of 65 cells/mm3. The most common reasons for delayed entry were feeling healthy (51%), fear of stigma and discrimination in the community (41%), time conflicts with work or school (33%), and fear of lack of confidentiality (26%). Independent predictors for delayed entry were feeling healthy (aOR 3.7, 95% CI 1.5–9.1), first positive HIV test at other site (aOR 2.9, CI 1.2–7.1), history of injection drug use (IDU) (aOR 2.9, 95% CI 1.1–7.9), work/school conflicts (aOR 4.3, 95% CI 1.7–10.8), prior registration at another clinic (aOR 77.4, 95% CI 8.6–697), detention or imprisonment (aOR 10.3, 95% CI 1.8–58.2), and perceived distance to clinic (aOR 3.7, 95% CI 1.0–13.7).

Conclusion

Delayed entry into HIV care in Vietnam is common and poses a significant challenge to preventing AIDS and opportunistic infections, decreasing mortality, and reducing HIV transmission. Improved linkages between testing and care are needed, particularly for patients who feel healthy, as well as incarcerated and drug-using populations who may face structural and social barriers to accessing care.     

Real‐time interactive two‐photon photoconversion of recirculating lymphocytes for discontinuous cell tracking in live adult mice

The potential usefulness of intravital two‐photon microscopy for fate mapping is limited by its inability to track cells beyond the confines of the imaging volume. Therefore, we have developed and validated a novel method for in vivo photolabelling of spatially‐restricted cells expressing the Kaede optical highlighter by two‐photon excitation. This has allowed us to optically mark a cohort of follicular B cells and track their dissemination from the original imaging volume in the lymph node to the spleen and contralateral lymph node. We also present the first demonstration, to our knowledge, of in vivo photoconversion of a freely moving single cell in a live adult animal. This method of `discontinuous' cell tracking therefore significantly extends the fate mapping capabilities of two‐photon microscopy to delineate the spatiotemporal dynamics of cellular processes that span multiple anatomical sites at the single cell level. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)