Prevalence, Risk Factors, and Perinatal Outcomes of Velamentous Umbilical Cord Insertion in Twin Pregnancies: A Single-Center Retrospective Study.

BACKGROUND: The effect of velamentous cord insertion (VCI) on perinatal outcomes in twin pregnancies is unclear due to conflicting findings. This retrospective study aimed to examine VCI prevalence and related risk factors in twin pregnancies and its association with adverse perinatal outcomes. METHODS: Women with twin pregnancies who delivered between January 2012 and December 2021 in a single tertiary hospital were included. The participants were divided into dichorionic (DC) and monochorionic diamniotic (MCDA) groups, and their maternal and fetal characteristics and VCI rates were compared. Logistic regression models were used to identify risk factors for VCI and VCI-related perinatal outcomes. RESULTS: Among the 694 twin pregnancies included in this study, the VCI rate was significantly higher in MCDA than in DC twins. Body mass index and MCDA twins were significant risk factors for VCI, whereas assisted reproductive technology pregnancy was a significant protective factor against VCI. In DC twins, VCI did not affect perinatal outcomes. In MCDA twins, VCI was a significant risk factor for fetal growth restriction, twin-to-twin transfusion syndrome, and preterm birth at <36 weeks. CONCLUSIONS: VCI was a prominent risk factor for adverse perinatal outcomes only in MCDA twins. Antenatal sonographic assessment of the umbilical cord insertion site would be beneficial.

Cover Crop Amendments and Lettuce Plant Growth Stages Alter Rhizobacterial Properties and Roles in Plant Performance.

Lettuce plants respond differently to cover crop amendments by altering their biomass and nitrogen uptake (Nup) at different plant growth stages. Nonetheless, plant-microbe interactions involved in the alterations are scarcely studied. This study elucidated how the properties of the soil microbial community inhabiting the rhizosphere associated with lettuce (Lactuca sativa L. var. crispa "Red fire") change during plant growth stages. Lettuce plants were cultivated in control soil and soil with rye, hairy vetch (HV), and rye plus HV (rye + HV) cover crop amendments. Rhizosphere soil samples were collected at the mid-growth and mature stages of plant development. DNA was extracted from the soil, and the 16S rRNA region was amplified using polymerase chain reaction to analyze bacterial genes and community structures and functions. Cover crop amendments and plant growth stages increased or decreased the relative abundances of bacterial taxa at the genus level. Plant maturity decreased 16S rRNA gene expression and the number of bacterial operational taxonomic units in all treatments. The unique, core, and shared taxa with low relative abundances may be associated with improved lettuce Nup and lettuce shoot and root biomass at each plant growth stage under different cover crop amendments based on multivariate analysis between plant indicators and bacterial genera groups. This study revealed the importance of bacterial groups with low relative abundance in plant-microbe interactions; such bacteria may promote the cover crop application for high lettuce productivity.

Ploidy distribution and DNA content variations of Lonicera caerulea (caprifoliaceae) in Japan.

Ploidy level and geographical distribution were investigated in Japanese Lonicera caerulea L. Flow cytometric analysis revealed the presence of DNA diploid and DNA tetraploid plants in Japan. Chromosome observation confirmed that diploid and tetraploid plants showed 2n = 2x = 8 and 2n =4x = 36, respectively. The DNA diploid populations were found only in lowland mires, Betsukai, Bekanbeushi, Kushiro and Kiritappu located in eastern Hokkaido. On the other hand, DNA tetraploid populations were distributed in a wide area of Hokkaido, and mainland of Japan. The habitats of DNA tetraploid plants were lowland to alpine region. The DNA content measurement with flow cytometry revealed significant differences in the relative DNA contents among DNA tetraploid populations. The relative DNA content within DNA tetraploid populations varied 1.157-fold at maximum, and might correlate with altitude indicating that DNA contents were smaller as altitude increases. The wide area of distribution in various environments of DNA tetraploid plants suggested the adaptability of the tetraploid plants. Although diploid and tetraploid populations were found, no triploid was detected, indicating crossing difficulty between diploid and tetraploid as confirmed by crossing experiment.

[Reliability of bioluminescent assay (ATP method) for testing antimicrobial susceptibility of Mycobacterium tuberculosis].

To evaluate the reliability of our previously reported antimicrobial susceptibility test by ATP method, we have compared our ATP method to the reference test methods such as Mycobacteria Growth Indicator Tube(MGIT) method, minimum inhibitory concentration(MIC) method, NCCLS M24-T agar proportion method(M24-T method), and Vite spectrum method. The concentrations of drugs used for the assessment were isoniazid(INH) 0.1 microgram/ml, rifampicin(RFP) 2.0 micrograms/ml, ethambutol(EB) 2.5 micrograms/ml, streptomycin (SM) 2.0 micrograms/ml, and kanamycin (KM) 5.0 micrograms/ml. When six M. tuberculosis ATCC strains were subjected to 6 independent experiments by using ATP method, highly reproducible results were obtained on the fifth day of the incubation. We examined correlation among ATP method and reference test methods in drug susceptibility testing for 65 clinical isolates of M. tuberculosis. The correlation between ATP method and MGIT-, MIC-, M24-T method were more than 95% for all drugs. When ATP method and Vite spectrum method was compared, the correlation was 87.7% for INH, 98.5% for RFP, 90.8% for EB, 92.3% for SM, 96.9% for KM. The culture period for determining susceptibility between ATP method and MGIT method was compared by using ATCC reference strains and clinical isolates. Six M. tuberculosis ATCC strains were subjected to 6 independent experiments. By the MGIT method, 8 days were required to obtain the results, whereas 3 days were enough by the ATP method. For 65 clinical isolates, the MGIT method required 9 days for determining susceptibility of all isolates. The ATP method required only 5 days for the same strains. These data demonstrate that the improved ATP method that we reported, is simple, rapid, highly reproducible and nonradiometric, and could be used for the assessment of drug susceptibility for M. tuberculosis with high reliability.