The effects of refreezing on the viscoelastic and tensile properties of ligaments

Biomechanical testing protocols for ligaments can be extensive and span two or more days. During this time, a specimen may have to undergo more than one cycle of freezing and thawing. Thus, the objective of this study was to evaluate the effects of refreezing on the viscoelastic and tensile properties of ligaments. The femur-medial collateral ligament-tibia complexes (FMTC) from six pairs of rabbit knees were used for this study. Following sacrifice, one leg in each pair was assigned to the fresh group and the FMTC was immediately dissected and prepared for testing. The contralateral knees were fresh-frozen at -20 degrees C for 3 weeks, thawed, dissected and then refrozen for one additional week before being tested as the refrozen group. The cross-sectional area and shape of the medial collateral ligament (MCL) was measured using a laser micrometer system. Stress relaxation and cyclic stress-relaxation tests in uniaxial tension were performed followed by a load to failure test. When the viscoelastic behavior of the MCL was described by the quasi-linear viscoelastic (QLV) theory, no statistically significant differences could be detected for the five constants (A, B, C, tau1, and tau2) between the fresh and refrozen groups (p > or = 0.07) based on our sample size. In addition, the structural properties of the FMTCs and the mechanical properties of the MCLs were also found to be similar between the two groups (p > or = 0.68). These results suggest that careful refreezing of the specimens had little or no effect on the biomechanical properties measured.     

Effect of polyethylene glycol and dimethyl sulfoxide on the fusion of bovine nuclear transfer using mammary gland epithelial cells

The effects of polyethylene glycol and dimethyl sulfoxide (PEG/DMSO) treatment of donor cells on the fusion and subsequent development of bovine nuclear transfer embryos using mammary gland epithelial (MGE) cells before electrofusion (fresh MGE cells) was studied. The same study was conducted on those cells that were frozen and stored in liquid nitrogen, and then thawed (frozen-thawed MGE cells). Experiment 1 showed that the exposure time and pH of PEG/DMSO solution affected the fusion of nuclear transfer, and that a higher fusion rate was obtained when fresh MGE cells were exposed to PEG/DMSO solution at pH 8.0 for 5 min. In Experiment 2, the proportion of fused oocytes with fresh PEG/DMSO-treated cells (70 +/- 6%) was significantly higher than that with non-treated cells (50 +/- 13%, p < 0.05). The same tendency was observed when frozen-thawed cells as donor nuclei were used (48 +/- 6% vs. 34 +/- 12%, p < 0.05). In addition, PEG/DMSO treatment has neither harmful nor beneficial effects on the cleavage and development of the blastocyst stage of reconstructed embryos (p > 0.05). The fusion and cleavage rates of frozen-thawed cells were significantly lower than those of fresh cells (p < 0.05). After 10 blastocysts, derived from fresh PEG/DMSO-treated cells, were transferred to five recipient heifers, one live female calf was obtained. Experiment 3 showed that PEG/DMSO treatment reduced the viability of both fresh and frozen-thawed MGE cells (p < 0.05). We conclude that the PEG/DMSO treatment of fresh MGE cells, as well as the frozen-thawed cells, before electrofusion has a positive effect on the fusion of nuclear transfer without decreasing the in vitro development of reconstructed embryos.     

Effectiveness of enhanced cognitive behavior therapy for bulimia nervosa in Japan: a randomized controlled trial protocol

Although fatigue is a common and distressing symptom in cancer survivors, the mechanism of fatigue is not fully understood. Therefore, this study aims to investigate the relation between the fatigue and mindfulness of breast cancer survivors using anxiety, depression, pain, loneliness, and sleep disturbance as mediators. Path analysis was performed to examine direct and indirect associations between mindfulness and fatigue. Participants were breast cancer survivors who visited a breast surgery department at a university hospital in Japan for hormonal therapy or regular check-ups after treatment. The questionnaire measured cancer-related-fatigue, mindfulness, anxiety, depression, pain, loneliness, and sleep disturbance. Demographic and clinical characteristics were collected from medical records. Two-hundred and seventy-nine breast cancer survivors were registered, of which 259 answered the questionnaire. Ten respondents with incomplete questionnaire data were excluded, resulting in 249 participants for the analyses. Our final model fit the data well (goodness of fit index = .993; adjusted goodness of fit index = .966; comparative fit index = .999; root mean square error of approximation = .016). Mindfulness, anxiety, depression, pain, loneliness, and sleep disturbance were related to fatigue, and mindfulness had the most influence on fatigue (β = − .52). Mindfulness affected fatigue not only directly but also indirectly through anxiety, depression, pain, loneliness, and sleep disturbance. The study model helps to explain the process by which mindfulness affects fatigue. Our results suggest that mindfulness has both direct and indirect effects on the fatigue of breast cancer survivors and that mindfulness can be used to more effectively reduce their fatigue. It also suggests that health care professionals should be aware of factors such as anxiety, depression, pain, loneliness, and sleep disturbance in their care for fatigue of breast cancer survivors. This study was registered in the University Hospital Medical Information Network Clinical Trials Registry (UMIN number. 000027720) on June 12, 2017.     

An Arabidopsis homolog of yeast ATG6/VPS30 is essential for pollen germination

Yeast (Saccharomyces cerevisiae) Atg6/Vps30 is required for autophagy and the sorting of vacuolar hydrolases, such as carboxypeptidase Y. In higher eukaryotes, however, roles for ATG6/VPS30 homologs in vesicle sorting have remained obscure. Here, we show that AtATG6, an Arabidopsis (Arabidopsis thaliana) homolog of yeast ATG6/VPS30, restored both autophagy and vacuolar sorting of carboxypeptidase Y in a yeast atg6/vps30 mutant. In Arabidopsis cells, green fluorescent protein-AtAtg6 protein localized to punctate structures and colocalized with AtAtg8, a marker protein of the preautophagosomal structure. Disruption of AtATG6 by T-DNA insertion resulted in male sterility that was confirmed by reciprocal crossing experiments. Microscopic analyses of AtATG6 heterozygous plants (AtATG6/atatg6) crossed with the quartet mutant revealed that AtATG6-deficient pollen developed normally, but did not germinate. Because other atatg mutants are fertile, AtAtg6 likely mediates pollen germination in a manner independent of autophagy. We propose that Arabidopsis Atg6/Vps30 functions not only in autophagy, but also plays a pivotal role in pollen germination.     

Naturally occurring CAR bacillus infection in a laboratory rat colony and epizootiological observations

An epizootic of chronic respiratory disease was found in a rat colony. Lungs of the symptomatic rats showed histopathologically severe peribronchial lymphoid cuffing. Filamentous bacteria were detected on the border of the tracheal and bronchial epithelium by light and electron microscopy. These bacteria did not grown on artificial media but propagated in embryonated chicken eggs. The disease was thus diagnosed as cilia-associated respiratory (CAR) bacillus infection. Epizootiological observations of the natural and experimentally induced cases revealed that the disease was highly contagious, slowly progressive and intractable. Contact infection may play a major role in the transmission of this disease.     

CD157 Marks Tissue-Resident Endothelial Stem Cells with Homeostatic and Regenerative Properties

1. Download high-res image (295KB)
2. Download full-size image

     

Characteristic glycopeptides associated with extreme human longevity identified through plasma glycoproteomics

Background

Glycosylation is highly susceptible to changes of the physiological conditions, and accordingly, is a potential biomarker associated with several diseases and/or longevity. Semi-supercentenarians (SSCs; older than 105?years) are thought to be a model of human longevity. Thus, we performed glycoproteomics using plasma samples of SSCs, and identified proteins and conjugated N-glycans that are characteristic of extreme human longevity.

Skewed male reproductive success and pollen transfer in a small fragmented population of the heterodichogamous tree <Emphasis Type="Italic">Machilus thunbergii</Emphasis>

Heterodichogamy is defined as the presence of two flower morphs that exhibit the male and female functions at different times among individuals within a population. Heterodichogamy is regarded as an adaptation to promote outcrossing through enhanced inter-morph mating, together with a 1:1 morph ratio. However, in highly fragmented populations, the morph ratio may be more likely to be biased by stochastic events. In such a situation, individuals of a minority morph within a population are expected to have higher reproductive success than those of a majority morph, which may suffer from pollen shortages of the minority morph. In this paper, we evaluated mating patterns and male reproductive success in a highly fragmented population of Machilus thunbergii, a putative heterodichogamous evergreen laurel tree. Results of paternity analysis indicated that the selfing rate was not clearly different between the two morphs. In contrast, the proportion of intra-morph mating was higher in the majority-morph (MM) mother trees than in the minority-morph (MF) mother trees. Bayesian estimated male reproductive success indicated that male reproductive success was higher in minority-morph (MF) than in majority-morph (MM) mother trees. These findings indicate that (1) the majority morph mothers, suffering a shortage of the opposite morph pollen, could partly compensate for the reduced reproductive success by intra-morph mating rather than by selfing, and (2) negative-frequency dependent selection may be involved in the maintenance of the two morphs.     

Light and scanning electron microscopic studies of the effects of CO2 laser on the palatine mucosa of rats

In order to verify the effects of CO2 laser on the palatine mucosa of rats, 15 animals were utilized. The animals were anaesthetized with thionembutal by intra-peritoneal injection and the palatine mucosa of each animal was irradiated with a single pulse of 10 W. The results showed that immediately after the irradiation of CO2 laser, the formation of small cavities is observed. The wound healing post operationem is gradually in 1 week. The region is totally occupied by neoformed connective tissue and epithelial cells. Numerous polymorphonuclear cells and fibroblasts may be seen between the neoformed collagen fibres.