Regulation of carotenoid accumulation and the expression of carotenoid metabolic genes in citrus juice sacs in vitro

In the present study, to investigate the mechanisms regulating carotenoid accumulation in citrus, a culture system was set up in vitro with juice sacs of three citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Valencia orange (Citrus sinensis Osbeck), and Lisbon lemon (Citrus limon Burm.f.). The juice sacs of all the three varieties enlarged gradually with carotenoid accumulation. The changing patterns of carotenoid content and the expression of carotenoid metabolic genes in juice sacs in vitro were similar to those ripening on trees in the three varieties. Using this system, the changes in the carotenoid content and the expression of carotenoid metabolic genes in response to environmental stimuli were investigated. The results showed that carotenoid accumulation was induced by blue light treatment, but was not affected by red light treatment in the three varieties. Different regulation of CitPSY expression, which was up-regulated by blue light while unaffected by red light, led to different changes in carotenoid content in response to these two treatments in Satsuma mandarin and Valencia orange. In all three varieties, increases in carotenoid content were observed with sucrose and mannitol treatments. However, the accumulation of carotenoid in the two treatments was regulated by distinct mechanisms at the transcriptional level. With abscisic acid (ABA) treatment, the expression of the genes investigated in this study was up-regulated in Satsuma mandarin and Lisbon lemon, indicating that ABA induced its own biosynthesis at the transcriptional level. This feedback regulation of ABA led to decreases in carotenoid content. With gibberellin (GA) treatment, carotenoid content was significantly decreased in the three varieties. Changes in the expression of genes related to carotenoid metabolism varied among the three varieties in response to GA treatment. These results provided insights into improving carotenoid content and composition in citrus during fruit maturation

Biomechanical comparison of meniscus-suture constructs for pullout repair of medial meniscus posterior root tears

Abstract Background Transtibial pullout repair for posterior meniscus root tear is widely performed to restore meniscal function. However, it is sometimes technically difficult to pass the suture through the posterior medial meniscus root in narrow joint space. To address this limitation, a new suture technique using an all-inside meniscal suture device through the tibial tunnel was proposed. The purpose of the present study was to compare the biomechanical properties of a meniscus-suture construct prepared using an all-inside meniscal suture device and those of the construct prepared using conventional suture techniques. Methods A total of 18 fresh-frozen porcine medial menisci were used and randomly divided into three groups according to the type of suturing technique applied. Three suturing methods were evaluated: suturing with all-inside meniscal suture device, single simple suture, and double simple sutures. All specimens were subjected to cyclic loading of 300 cycles followed by a load-to-failure test. The displacement after cyclic loading, the ultimate failure load, and the mode of failure were evaluated. Results There was no significant difference among the three suturing techniques regarding both displacement after cyclic loading and ultimate failure load. Suture breakage was the most common failure mode in each group. Conclusions The biomechanical properties of meniscus-suture construct with the all-inside meniscal suture device were equivalent to those obtained using conventional suture techniques. Our results suggest that pullout repair using the all-inside meniscal suture device through the tibial tunnel could serve as an alternative suture technique for the repair of posterior meniscus root tears

Diagnostic Performance and Safety of Positron Emission Tomography Using 18F-Fluciclovine in Patients with Clinically Suspected High- or Low-grade Gliomas: A Multicenter Phase IIb Trial

Objective(s): The study objective was to assess the diagnostic performance of positron emission tomography (PET) for gliomas using the novel tracer 18F-fluciclovine (anti-[18F]FACBC) and to evaluate the safety of this tracer in patients with clinically suspected gliomas.Methods: Anti-[18F]FACBC was administered to 40 patients with clinically suspected high- or low-grade gliomas, followed by PET imaging. T1-weighted, contrast-enhanced T1-weighted, and fluid-attenuated inversion recovery (or T2-weighted) magnetic resonance imaging (MRI) scans were obtained to plan for the tissue collection. Tissues were collected from either “areas visualized using anti-[18F]FACBC PET imaging but not using contrast-enhanced T1-weighted imaging” or “areas visualized using both anti-[18F]FACBC-PET imaging and contrast-enhanced T1-weighted imaging” and were histopathologically examined to assess the diagnostic accuracy of anti-[18F]FACBC-PET for gliomas.Results: The positive predictive value of anti-[18F]FACBC-PET imaging for glioma in areas visualized using anti-[18F]FACBC-PET imaging, but not visualized using contrast-enhanced T1- weighted images, was 100.0% (26/26), and the value in areas visualized using both contrastenhanced T1-weighted imaging and anti- [18F]FACBC-PET imaging was 87.5% (7/8). Twelve adverse events occurred in 7 (17.5%) of the 40 patients who received anti-[18F]FACBC. Five events in five patients were considered to be adverse drug reactions; however, none of the events were serious, and all except one resolved spontaneously without treatment.Conclusion: This Phase IIb trial showed that anti-[18F]FACBC-PET imaging was effective for the detection of gliomas in areas not visualized using contrast-enhanced T1-weighted MRI and the tracer was well tolerated