During the analysis of plant male meiocytes coming from destroyed meiocyte columns (united multicellular structures formed by male meiocytes in each anther locule), a considerable amount of ...information becomes unavailable. Therefore, in this study intact meiocyte columns were studied by volume microscopy in wild-type rye for the most relevant presentation of 3-D structure of rye meiocytes throughout meiosis.
We used two types of volume light microscopy: confocal laser scanning microscopy and non-confocal bright-field scanning microscopy combined with alcohol and aldehyde fixation, as well as serial block-face scanning electron microscopy.
Unusual structures, called nuclear protuberances, were detected. At certain meiotic stages, nuclei formed protuberances that crossed the cell wall through intercellular channels and extended into the cytoplasm of neighbouring cells, while all other aspects of cell structure appeared to be normal. This phenomenon of intercellular nuclear migration (INM) was detected in most meiocytes at leptotene/zygotene. No cases of micronucleus formation or appearance of binucleated meiocytes were noticed. There were instances of direct contact between two nuclei during INM. No influence of fixation or of mechanical impact on the induction of INM was detected.
Intercellular nuclear migration in rye may be a programmed process (a normal part of rye male meiosis) or a tricky artefact that cannot be avoided in any way no matter which approach to meiocyte imaging is used. In both cases, INM seems to be an obligatory phenomenon that has previously been hidden by limitations of common microscopic techniques and by 2-D perception of plant male meiocytes. Intercellular nuclear migration cannot be ignored in any studies involving manipulations of rye anthers.
BACKGROUND: Rapid and sensitive methods for the detection of bacteria in platelet concentrates (PCs) are required as well as inactivation techniques to decrease the transfusion‐associated risk of ...infection from bacterially contaminated PCs. In this study, a rapid microbiologic method for the sensitive counting of viable bacteria in PCs was developed by combining a fluorescent staining technique and a bioimaging system.
STUDY DESIGN AND METHODS: An esterase indicator, carboxyfluorescein diacetate, was used to detect physiologically active bacteria. Treatment was optimized to selectively remove platelets (PLTs). Bacterial cells trapped on a filter were automatically discriminated from other particles or PLT debris and counted by a bioimaging system. The sensitivity, rapidity, and recovery rates were evaluated using PCs spiked with 14 reference bacterial strains and clinical isolates.
RESULTS: Lysis treatment with enzyme and detergent was effective to remove PLTs and white blood cells. Two buffers for fluorescent vital staining were needed for highly sensitive detection of pathogenic bacteria. Fewer than 100 cells spiked in 5‐mL PCs were detected by the bioimaging system after treatment and fluorescent staining, and this result shows that PLTs are selectively digested by the treatment. Bacterial cells spiked in 25‐mL PCs were detected within 45 minutes (treatment, 15 min; filtration and fluorescent staining, 15 min; automated counting and precise image analysis, 10‐15 min).
CONCLUSION: The microbiologic method described here is rapid and sensitive, and this method has potential for the screening of PCs contaminated with bacterial cells. Furthermore, this method could contribute to further evaluation of inactivation techniques.
Background
Bacterial contamination in platelet concentrates (PCs) is a major problem in transfusion medicine. Contamination with Staphylococcus aureus is occasionally missed, even with cultural ...screening.
Study design and methods
Donors implicated in S. aureus‐contaminated PC were followed up. Skin and nasal swab specimens from six donors and S. aureus isolated from PCs related to these donors were subjected to multilocus sequence typing (MLST) and pulsed‐field gel electrophoresis (PFGE) to determine the identity of bacteria. To evaluate the validity of the screening method using BacT/ALERT 3D, we spiked S. aureus and three other bacterial species as comparisons into PCs and investigated their growth pattern.
Results
S. aureus was isolated from all nasal specimens and from the arm skin specimens of three donors with atopic dermatitis. In all cases, the S. aureus strains isolated from the PC and those from the nasal and skin specimens of the same donor showed concordant results using MLST and PFGE. In the spiking study, S. aureus showed irregular detectability over 24 to 48 h post‐spike periods, whereas the three other bacterial species were detected in all culture bottles after a 24‐h post‐spike period.
Discussion
The strain identity of S. aureus between donor and PC suggests that the contaminants were derived from those colonized in the donor. Furthermore, S. aureus yielded false‐negative results using BacT/ALERT 3D.
When trains run repeatedly on the ballasted track, the track irregularity gradually increases due to the train load. Therefore, it is necessary to develop a maintenance plan to efficiently operate ...limited maintenance costs and maintenance machineries, and to realize track conditions that maintain train safety and ride comfort over the medium to long term. As one of efficient track maintenance methods, combining tamping and grinding in a form of “Combined maintenance,” is expected to extend a track maintenance cycle and decrease the total cost for track maintenance activities. However, quantitative analysis and estimated modeling of the effect on this extended maintenance has so far been conducted only for Shinkansen. In this paper, we examine the effect of combined maintenance on conventional lines in order to improve the versatility of combined maintenance for practical use. In addition, we show the results of simulations of track conditions that would be realized when combined maintenance is performed on conventional lines.
BACKGROUND
In 2014, we experienced the first isolation of Lactococcus garvieae from a platelet concentrate (PC). Thereafter, L. garvieae contamination of PCs occurred in two more cases in Japan. It ...is rare that bacterial contamination with uncommon strains like this species occurs frequently within a short period. Therefore, we performed a detailed analysis of the characteristics of these strains.
STUDY DESIGN AND METHODS
Three bacterial strains were identified by biochemical testing and molecular analysis. Genomic diversity was characterized by multilocus sequence typing (MLST). To observe growth kinetics in blood components, PCs were inoculated with the three different strains.
RESULTS
All three strains were identified as L. garvieae by molecular analysis. Each strain belonged to a different phylogenetic group according to MLST analysis. In the spiking trial, the three strains demonstrated differences in their final concentrations and changes in appearance of PCs.
CONCLUSION
In this study, all three L. garvieae strains were correctly identified by molecular analysis. Since the three strains were collected in different regions of Japan and belonged to different phylogenetic groups according to MLST analysis, it is suggested that L. garvieae have a wide distribution with diversity in Japan. In PCs, the three L. garvieae strains showed clear differences in growth kinetics and changes in appearance of PCs. These differences may have been the primary determinant of whether PC contamination was detected before transfusion. Moreover, L. garvieae represents an emerging foodborne bacterium that can cause transfusion‐transmitted bacteremia. Understanding our cases may help prevent bacterial contamination of blood products.
A novel electrolyte system for a rechargeable magnesium battery has been developed. The electrolyte consists of ethylmagnesiumbromide in tetrahydrofuran (EtMgBr/THF) with an ionic liquid (IL) of ...quaternary ammonium salt. The ionic conductivity of the electrolyte with the composition of EtMgBr/THF:IL being 3:1 in volume was 7.44
mS
cm
−1 at 25
°C. A reversible processes of cathodic deposition and anodic dissolution of magnesium has been successfully achieved in the mixed electrolyte system of EtMgBr/THF
+
IL at room temperature.
Background
Transfusion‐transmitted bacterial infections (TTBIs) in Japan have been largely prevented due to a short shelf life of 3.5 days after blood collection for platelet concentrate (PC) and ...washed PCs (WPCs; PC in which 95% plasma is replaced by platelet additive solution).
Case Presentation
Case 1: In January 2018, a woman in her 50s with aplastic anaemia who received WPC transfusion and developed a fever the next day and Streptococcus dysgalactiae subspecies equisimilis (SDSE) was detected in the residual WPC. Case 2: In May 2018, a man in his 60s with a haematologic malignancy who received PC transfusion and developed chills during the transfusion. SDSE was detected in the patient's blood and residual PC.
The contaminated platelet products were both manufactured from blood donated by the same donor. The multi‐locus sequencing typing revealed that SDSE detected in case 1 was identical to that from case 2; however, whole blood subsequently obtained from the donor was culture negative.
Conclusion
WPC and PC produced from two blood donated 106 days apart by the same donor were contaminated with SDSE of the same strain and both caused TTBIs. Safety measures should be considered regarding blood collection from a donor with a history of bacterial contamination.
Glaucoma, the leading cause of blindness, damages the retinal ganglion cells. Elevated intraocular pressure (IOP) is a high-risk factor for glaucoma, so topical hypotensive drugs are usually used for ...treatment. Because not all patients do not respond adequately to current treatments, there is a need to identify a new molecular target to reduce IOP. Here, we have assessed the role of P2Y1 receptors in mediating elevated IOP.
P2Y
receptor agonist was instilled into the eyes of mice, and the IOP changes were measured by a rebound-type tonometer. Expression of P2Y
receptors was estimated by immunohistochemistry. Ocular function was measured by a multifocal electroretinogram.
A single dose of the P2Y
receptor agonist transiently reduced IOP and such effects were absent in P2Y
receptor-deficient (P2Y
KO) mice. P2Y
receptors were functionally expressed in the ciliary body, trabecular meshwork and Schlemm's canal. Activation of P2Y
receptors negatively regulated aquaporin 4 (AQP4) function but up-regulated endothelial NOS (eNOS). P2Y
KO mice showed chronic ocular hypertension regardless of age. P2Y
KO mice at 3 months old showed no damage to retinal ganglion cells, whereas 12-month-old mice showed a significant loss of these cells and impairment of ocular functions. Damage to retinal ganglion cells was attenuated by chronic administration of an IOP-reducing agent.
Activation of P2Y
receptors reduced IOP via dual pathways including AQP4 and eNOS. Loss of P2Y
receptors resulted in glaucomatous optic neuropathy, suggesting that P2Y
receptors might provide an effective target in the treatment of glaucoma.
