Overexpression of the protein disulfide isomerase AtCYO1 in chloroplasts slows dark-induced senescence in Arabidopsis.

BACKGROUND: Chlorophyll breakdown is the most obvious sign of leaf senescence. The chlorophyll catabolism pathway and the associated proteins/genes have been identified in considerable detail by genetic approaches combined with stay-green phenotyping. Arabidopsis CYO1 (AtCYO1), a protein disulfide reductase/isomerase localized in the thylakoid membrane, is hypothesized to assemble the photosystem by interacting with cysteine residues of the subunits. RESULTS: In this study, we report that ectopic overexpression of AtCYO1 in leaves induces a stay-green phenotype during darkness, where oxidative conditions favor catabolism. In AtCYO1ox leaves, Fv/Fm and both chlorophyll a and chlorophyll b content remained high during dark-induced senescence. The thylakoid ultrastructure was preserved for a longer time in AtCYO1ox leaves than in wild type leaves. AtCYO1ox leaves maintained thylakoid chlorophyll-binding proteins associated with both PSII (D1, D2, CP43, CP47, LHCB2, and Cyt f) and PSI (PSA-A/B), as well as stromal proteins (Rubisco and ferredoxin-NADP+ reductase). AtCYO1ox did not affect senescence-inducible gene expression for chlorophyll catabolism or accumulation of chlorophyll catabolites. CONCLUSIONS: Our results suggest that ectopic overexpression of AtCYO1 had a negative impact on the initiation of chlorophyll degradation and proteolysis within chloroplasts. Our findings cast new light on the redox regulation of protein disulfide bonds for the maintenance of functional chloroplasts.

Achieving a cure for anastomotic leakage following laparoscopic low anterior resection for rectal cancer using an endoscopic closure device, a MANTIS clip.

Anastomotic leakage (AL) following low anterior resection (LAR) for rectal cancer is a major complication. While most reports focus on the closure of AL using over-the-scope clip (OTSC), few reports are available on the use of through-the-scope clip (TTSC). This is because TTSC is not typically designed for full-thickness closure, unlike OTSC. However, a MANTIS clip, categorized as TTSC, is indicated for full-thickness closure. A 73-year-old man diagnosed with AL 7 days postoperatively following laparoscopic LAR underwent laparoscopic drainage and ileostomy the next day. Although the drainage led to the shrinkage of the fistula, it persisted even after 2 months. Consequently, the fistula orifice was closed using a MANTIS clip under colonoscopy and radiography. Two days later, the patient was discharged. The drain was withdrawn cautiously to prevent residual fistula and removed completely on day 29. This report highlights our experience in using a MANTIS clip for AL following LAR.

Evaluation of X-ray protective goggles in mitigating eye lens radiation exposure during radiopharmaceutical handling and patient care in nuclear medicine.

The aim of this study is to estimate eye lens exposure dose when handling radiopharmaceuticals and interacting with patients receiving radiopharmaceuticals, and to verify the usefulness of X-ray protective goggles in mitigating such radiation exposure using phantoms. To evaluate radiation exposure during the handling of radiopharmaceuticals, we employed a fluorescent glass dosimeter to measure the radiation doses associated with 99mTc, 123I, 131I, 111In, and 18F at distances of 30 cm and 60 cm, followed by calculation of the 3 mm dose equivalent rate (3DER). We then estimated the dose reduction rates for various scenarios, including the use of syringe shields and X-ray protective goggles with lead equivalences of 0.07, 0.15, 0.75, and 0.88 mmPb, as well as their combined application. X-ray protective goggles with lead equivalence of 0.75 mmPb outperformed those with 0.07 mmPb and 0.15 mmPb, for all radionuclides and at both source distances. X-ray protective goggles with 0.88 mmPb outperformed those with 0.75 mmPb during handling of 131I and 111In at a distance of 30 cm. In the remaining scenarios, X-ray protective goggles with 0.88 mmPb resulted in marginal reductions or no discernible additional effects. The overall shielding effect of X-ray protective goggles was less pronounced for 131I and 18F, but the combined use of a syringe shield with X-ray protective goggles with 0.75 or 0.88 mmPb improved the dose reduction rate for all scenarios. In simulating patient care, X-ray protective goggles with 0.88 mmPb demonstrated a dose reduction effect of approximately 50% or more. X-ray protective goggles could reduce the 3DER for the eye lens, and were more effective when combined with a syringe shield. It is valid to use a lead equivalence of 0.88 mmPb to fully harness the protective capabilities of X-ray shielding goggles when dealing with all five types of nuclides in clinical settings.

Hyaline-vascular type unicentric Castleman disease with dysplastic follicular dendritic cell proliferative lesions: a case report.

Castleman disease (CD) is a rare lymphoproliferative disease. Hyaline-vascular type unicentric CD has a good prognosis if completely resected during surgery. However, follicular dendritic cell proliferative lesions have the potential for recurrence and metastasis. A 22-year-old man was referred to our hospital with the chief complaint of nausea and vomiting. These symptoms were caused by a right mesocolonic tumor pushing the duodenum. The patient underwent laparoscopic tumorectomy and complete surgical excision. The postoperative course was uneventful, with no complications. Pathological examination confirmed that the tumor was an enlarged lymph node, typical of hyaline vascular-type CD; however, follicular dendritic cell proliferative lesions were noted. We report a rare case of hyaline-vascular-type CD with follicular dendritic cell proliferative lesions associated with malignancy, as limited case reports exist on this particular disease.

Variation in blood pressure and heart rate of radiological technologists in worktime tracked by a wearable device: A preliminary study.

The aim of this preliminary study was to measure the systolic BP (SBP) and diastolic BP (DBP) and heart rate (HR) of radiological technologists by WD, and evaluate variation among individuals by worktime, day of the week, job, and workplace. Measurements were obtained using a wristwatch-type WD with optical measurement technology that can measure SBP and DBP every 10 minutes and HR every 30 minutes. SBP, DBP, and HR data obtained at baseline and during work time were combined with the hours of work, day of the week, job, and workplace recorded by the participants in 8 consecutive weeks. We calculated the mean, the ratio to baseline and coefficient of variation [CV(%)] for SBP, DBP, and HR. SBP, DBP, and HR values were significantly higher during work hours than at baseline (p<0.03). The ratio to baseline values ranged from 1.02 to 1.26 for SBP and from 1.07 to 1.30 for DBP. The ratio to baseline for SBP and DBP showed CV(%) of approximately 10% according to the day of the week and over the study period. For HR, ratio to baseline ranged from 0.95 to 1.29. The ratio of mean BP to baseline was >1.2 at the time of starting work, middle and after lunch, and at 14:00. The ratio to baseline of SBP were 1.2 or more for irradiation, equipment accuracy control, registration of patient data, dose verification and conference time, and were also working in CT examination room, treatment planning room, linac room, and the office. CV(%) of BP and HR were generally stable for all workplaces. WD measurements of SBP, DBP, and HR were higher during working hours than at baseline and varied by the individuals, work time, job, and workplace. This method may enable evaluation of unconscious workload in individuals.

[Risk Communication of Radiation Exposure for Diagnosis: A Questionnaire Survey].

PURPOSE: We investigated how a radiologic technologist explains to a patient about the risk of radiation exposure involved by the radiological examination. METHODS: In this institutional review board-approved, cross-sectional study, an online questionnaire link was emailed to 650 radiological technologists who are members of the National Hospital Kanto Koshinetsu Radiological Technologist Association. The questions to survey risk communication included the ideal and reality explanation for radiation exposure to patients, the respondent's educational background, and years of experience. Statistical analysis was performed using the Kruskal-Wallis test and Bonferroni correction as a multiple comparison test. RESULTS: Among the 650 radiological technologists, 245 (37.7%) completed the online questionnaire. The most common response was to compare and convey the doses of radiation during examination and background radiation when asked by a patient about risk. In the cross-analysis, the Kruskal-Wallis test showed no significant difference in what was explained according to educational background. According to years of experience, a significant difference in the content was found about explanation of the risk to patients. CONCLUSIONS: We clarified the actual condition of risk communication related to the exposure in radiological examinations. In the future, development of risk communication is expected by improving the knowledge and information of "risk" and giving explanations requested by patients.

Proliferation and differentiation potential of pluripotent mesenchymal precursor C2C12 cells on resin-based restorative materials.

This study investigated the proliferation and differentiation potential of pluripotent mesenchymal cells on three resin-based restoratives using a typical pluripotent mesenchymal precursor cell line, C2C12. C2C12 cells were cultured for 3-21 days on cured specimens of a Bis-GMA/TEGDMA-based composite resin (APX; Clearfil AP-X), a 4-META/MMA-based resin cement (SB; Superbond C&B) or a HEMA-containing resin modified glass-ionomer (LC; Fuji Ionomer Type II LC). To examine the influences on differentiation potential, alkaline phosphatase (ALP) activity of the cells cultured on each material was determined. On APX and SB, cells adhered and proliferated well, and no significant influences on ALP activity were observed. In contrast, poor cell proliferation and significant suppression of ALP activity were observed for cells cultured on LC, similar to those cultured on a zinc oxide EBA cement used as a control material. Bis-GMA/TEGDMA-based composite resin and 4-META/MMA-based resin exhibited better biocompatibility for C2C12 cells than HEMA-containing resin modified glass-ionomer, suggesting a potential advantage of the former two resins to show smaller influences on regeneration of periapical or periodontal tissue.

Responses of MC3T3-E1 cells to three dental resin-based restorative materials.

This study aimed to examine the influences of three dental resin-based restorative materials on cells associated with hard tissue regeneration using osteoblastic MC3T3-E1 cells. A Bis-GMA-based resin composite [Clearfil AP-X (APX)], an MMA-based resin cement [Superbond C&B (SB)], and a resin-modified glass-ionomer [Fuji Ionomer Type II LC (LC)] were tested. A zinc oxide eugenol cement [Super EBA (EBA)] was included in the study for comparison. MC3T3-E1 cells were cultured on set materials for 3, 7, 14, or 21 days. Cell attachment and proliferation were observed by scanning electron microscopy, and mitochondrial dehydrogenase and alkaline phosphatase (ALP) activities of the cells were evaluated. Cell cultures on polystyrene tissue culture dishes served as controls. On APX and SB, cells demonstrated attachment, spreading, and proliferation similar to the controls. In contract, cells adhered and proliferated poorly on LC and EBA. The mitochondrial function and ALP activity of the cells were significantly suppressed (p < 0.05, Scheffe's F test) throughout the experimental period when cultured on LC or EBA, although APX and SB exhibited less inhibition. The results indicate that APX and SB are less toxic to proliferation and differentiation of MC3T3-E1, suggesting that a smaller influence on cementogenesis on these materials can be expected.

Rice CYO1, an ortholog of Arabidopsis thaliana cotyledon chloroplast biogenesis factor AtCYO1, is expressed in leaves and involved in photosynthetic performance.

In the dicotyledonous plant Arabidopsis thaliana, the cotyledon chloroplast biogenesis factor AtCYO1 is crucial for the biogenesis of cotyledon chloroplasts. Arabidopsis mutants lacking AtCYO1 have pale cotyledons but develop normal mature leaves. In the monocotyledonous plant Oryza sativa, the gene OsCYO1 has high sequence identity to AtCYO1, but its function is unknown. We examined the role of OsCYO1 in O. sativa. We first confirmed that transformation with OsCYO1 could recover the phenotype of the Arabidopsis cyo1 mutant. Similar to AtCYO1, recombinant OsCYO1 has protein disulfide reductase (PDR) activity, which increased as a function of dieosin glutathione disulfide concentration with an apparent Km of 3.2µM and Kcat of 0.53min-1. The PDR activity was reduced when NADPH or NADH was used as an electron donor; however, PDR activity was observed with OsCYO1 and glutathione, suggesting that glutathione may serve as a reducing agent for OsCYO1 in vivo. In O. sativa, the OsCYO1 transcript level was higher in leaves compared with the coleoptile, which is the first leaf-like organ that forms during rice embryogenesis. Many OsCYO1 mutant lines defective in RNA interference had green leaves, however, three mutant lines had not only albino coleoptile but also albino leaves. Those having green leaves reduced photosynthetic performance in leaves. Our results demonstrate that OsCYO1 is enzymatically equivalent to AtCYO1 but that the physiological role of OsCYO1 in monocotyledonous plants may differ from that of AtCYO1 in dicotyledonous plants.

Effects of monomers eluted from dental resin restoratives on osteoblast-like cells.

Resin-modified glass-ionomer (RMGIC) has been demonstrated to exhibit inhibition on the growth and differentiation of osteoblasts on its surface. In this study, the hypothesis that the different levels of inhibitory effects on osteoblasts of resin restoratives depend on elution of unpolymerized monomers was examined. Release of monomers from cured specimens of Bis-GMA/TEGDMA-composites, MMA-resin cements, or HEMA-containing RMGIC was determined and osteoblast-like MC3T3-E1 cells were cultured in the presence of 100-10 microg/mL of TEGDMA, 10-1 microg/mL of MMA, or 400-50 microg/mL of HEMA according to the release concentrations. Cell proliferation, alkaline phosphatase (ALP) activity, the expression of osteoblastic markers, and mineralized tissue formation were evaluated. TEGDMA and MMA at the concentrations tested did not affect the growth of MC3T3-E1 and exhibited little harmful effects on their differentiation and mineralization. On the contrary, HEMA inhibited proliferation, ALP activities, the expression of osteocalcin, and mineralized tissue formation at 200 microg/mL or more. These results indicate that HEMA at the concentrations similar to that observed in elution tests affected osteoblastic proliferation, differentiation, and mineralization, suggesting that elution of unreacted HEMA could be the main component of the adverse effects of RMGIC on osteoblast-like cells and influences of resin restoratives on the osteoblasts are possibly dependant on release characteristics of unpolymerized monomers.