Artificial Conditioner for Stored Organs

We have developed an artificial organ conditioning system in order not only to condition but also evaluate the viability for transplant graft of kidneys which have been stored for a long time and damaged by warm ischaemia following cardiac arrest. The conditioning system consisted of an artificial lung, a roller pump, an organ chamber and perfusate. The perfusate was prepared with electrolytes, fluorocarbon, amino acid, glucose, an oxygen scavenger and so on. Conditioning was performed by continuous perfusion under mild hypothermia at 24° C. Mildly damaged kidneys (0 and 30 minutes warm ischaemia rabbit kidneys) were well conditioned but severely damaged kidneys failed to produce urination. Our device successfully exposed the viability of stored kidneys and the successful conditioning of damaged kidneys due to warm ischaemia avoiding transplantation. By establishing our method, the harvesting of kidneys following cardiac arrest will be feasible.

Reduction of EDA (+) fibronectin and its clinical importance on cryofiltration

Cryofiltration (CRYO) removes cryogel, which is a combination of fibrinogen (Fbg) and fibronectin (FN), containing pathological substances. The purpose of this study was to measure cryogel EDA(+) FN and study the relationship between EDA(+) FN and clinical symptoms in patients with rheumatoid arthritis, SLE and polymyositis. Cryogel contains 51 times more EDA(+) FN than plasma. The patients with rheumatoid arthritis showed a high level of EDA(+) FN in their plasma, and the EDA(+) FN level in plasma corresponded with changes in joint pain. We calculated the clearance level at several points in cryofiltration, and the reduction enabled us to evaluate the CRYO device. The EDA(+) FN clearance was 23.3 ± 6.4 ml/min, the pFN clearance 16.5 ± 4.1 ml/min, and the Fbg clearance 22.9 ± 5.7 ml/min. As the plasma flow in cryofiltration was 30 ml/min, a clearance of EDA(+) FN and Fbg, approximately 23 ml/min, was obviously high. The study of the plasma level change of EDA(+) FN during cryofiltration revealed a temporary elevation. These results suggest that the EDA(+) FN was most efficiently reduced by cryofiltration, would become a good indicator on plasmapheresis, and might move from other tissues into the blood during cryofiltration.

MMP20 Overexpression Disrupts Molar Ameloblast Polarity and Migration

Ameloblasts responsible for enamel formation express matrix metalloproteinase 20 (MMP20), an enzyme that cleaves enamel matrix proteins, including amelogenin (AMELX) and ameloblastin (AMBN). Previously, we showed that continuously erupting incisors from transgenic mice overexpressing active MMP20 had a massive cell infiltrate present within their enamel space, leading to enamel mineralization defects. However, effects of MMP20 overexpression on mouse molars were not analyzed, although these teeth more accurately represent human odontogenesis. Therefore, MMP20-overexpressing mice ( Mmp20^+/+Tg⁺) were assessed by multiscale analyses, combining several approaches from high-resolution micro-computed tomography to enamel organ immunoblots. During the secretory stage at postnatal day 6 (P6), Mmp20^+/+Tg⁺ mice had a discontinuous ameloblast layer and, unlike incisors, molar P12 maturation stage ameloblasts abnormally migrated away from the enamel layer into the stratum intermedium/stellate reticulum. TOPflash assays performed in vitro demonstrated that MMP20 expression promoted β-catenin nuclear localization and that MMP20 expression promoted invasion through Matrigel-coated filters. However, for both assays, significant differences were eliminated in the presence of the β-catenin inhibitor ICG-001. This suggests that MMP20 activity promotes cell migration via the Wnt pathway. In vivo, the unique molar migration of amelogenin-expressing ameloblasts was associated with abnormal deposition of ectopic calcified nodules surrounding the adherent enamel layer. Enamel content was assessed just prior to eruption at P15. Compared to wild-type, Mmp20^+/+Tg⁺ molars exhibited significant reductions in enamel thickness (70%), volume (60%), and mineral density (40%), and MMP20 overexpression resulted in premature cleavage of AMBN, which likely contributed to the severe defects in enamel mineralization. In addition, Mmp20^+/+Tg⁺ mouse molar enamel organs had increased levels of inactive p-cofilin, a protein that regulates cell polarity. These data demonstrate that increased MMP20 activity in molars causes premature degradation of ameloblastin and inactivation of cofilin, which may contribute to pathological Wnt-mediated cell migration away from the enamel layer.

Longitudinal effects of disaster-related experiences on mental health among Fukushima nuclear plant workers: The Fukushima NEWS Project Study

BACKGROUND

The Fukushima Nuclear Energy Workers' Support (NEWS) Project Study previously showed that experiences related to the Fukushima nuclear disaster on 11 March 2011 had a great impact on psychological states, including post-traumatic stress response (PTSR) and general psychological distress (GPD), among the Fukushima nuclear plant workers. To determine the causal relationship between disaster-related experiences and levels of psychological states, we conducted a 3-year longitudinal study from 2011 to 2014.

METHOD

PTSR and GPD of the nuclear plant workers were assessed by annual questionnaires conducted from 2011 to 2014. The present study included a total of 1417 workers who provided an assessment at baseline (2011). A total of 4160 observations were used in the present analysis. The relationship between disaster-related experiences and psychological states over time was analysed using mixed-effects logistic regression models.

RESULTS

A declining influence of disaster-related experiences on PTSR over time was found. However, the impact on PTSR remained significantly elevated even 3 years after the disaster in several categories of exposure including the experience of life-threatening danger, experiences of discrimination, the witnessing of plant explosion, the death of a colleague and home evacuation. The associations between GPD and disaster-related experiences showed similar effects.

CONCLUSIONS

The effects of disaster-related experiences on psychological states among the nuclear plant workers reduced over time, but remained significantly high even 3 years after the event.