15 research outputs found
Mutations in N-terminal flanking region of blue light-sensing light-oxygen and voltage 2 (LOV2) domain disrupt its repressive activity on kinase domain in the Chlamydomonas phototropin.
Phototropin is a light-regulated kinase that mediates a variety of photoresponses such as phototropism, chloroplast positioning, and stomata opening in plants to increase the photosynthetic efficiency. Blue light stimulus first induces local conformational changes in the chromophore-bearing light-oxygen and voltage 2 (LOV2) domain of phototropin, which in turn activates the serine/threonine (Ser/Thr) kinase domain in the C terminus. To examine the kinase activity of full-length phototropin conventionally, we employed the budding yeast Saccharomyces cerevisiae. In this organism, Ser/Thr kinases (Fpk1p and Fpk2p) that show high sequence similarity to the kinase domain of phototropins exist. First, we demonstrated that the phototropin from Chlamydomonas reinhardtii (CrPHOT) could complement loss of Fpk1p and Fpk2p to allow cell growth in yeast. Furthermore, this reaction was blue light-dependent, indicating that CrPHOT was indeed light-activated in yeast cells. We applied this system to a large scale screening for amino acid substitutions in CrPHOT that elevated the kinase activity in darkness. Consequently, we identified a cluster of mutations located in the N-terminal flanking region of LOV2 (R199C, L202L, D203N/G/V, L204P, T207I, and R210H). An in vitro phosphorylation assay confirmed that these mutations substantially reduced the repressive activity of LOV2 on the kinase domain in darkness. Furthermore, biochemical analyses of the representative T207I mutant demonstrated that the mutation affected neither spectral nor multimerization properties of CrPHOT. Hence, the N-terminal flanking region of LOV2, as is the case with the C-terminal flanking Jα region, appears to play a crucial role in the regulation of kinase activity in phototropin
Diagnostic value of procalcitonin and presepsin for sepsis in critically ill adult patients: a systematic review and meta-analysis
Abstract Background Early and accurate diagnosis of sepsis is challenging. Although procalcitonin and presepsin have been identified as potential biomarkers to differentiate between sepsis and other non-infectious causes of systemic inflammation, the diagnostic accuracy of these biomarkers remains controversial. Herein, we performed a comprehensive meta-analysis to assess the overall diagnostic value of procalcitonin and presepsin for the diagnosis of sepsis. Methods We searched three electronic databases (MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials) for relevant studies. Two authors independently screened articles on the basis of inclusion and exclusion criteria. The pooled sensitivity, specificity, and summary receiver operating characteristic curves were estimated. The quality of evidence for diagnostic accuracy in absolute effects, i.e., the number of true or false positives and true or false negatives, gave a particular pre-test probability. Results We included 19 studies (19 observational studies and no randomized controlled trials) that had enrolled 3012 patients. Analyses of summary receiver operating characteristic curves revealed areas under the receiver operating characteristic curves of 0.84 for procalcitonin and 0.87 for presepsin. The pooled sensitivities and specificities were 0.80 (95% confidence interval 0.75 to 0.84) and 0.75 (95% confidence interval 0.67 to 0.81) for procalcitonin. For presepsin, these values were 0.84 (95% confidence interval 0.80 to 0.88) and 0.73 (95% confidence interval 0.61 to 0.82), respectively. There were no statistically significant differences in both pooled sensitivities (p = 0.48) and specificities (p = 0.57) between procalcitonin and presepsin. Conclusion Our meta-analysis provided evidence that the diagnostic accuracy of procalcitonin and presepsin in detecting infection was similar and that both are useful for early diagnosis of sepsis and subsequent reduction of mortality in critically ill adult patients. Systematic review registration The study was registered in PROSPERO under the registration number CRD42016035784
Radiographic Assessment of Spinopelvic Sagittal Alignment from Sitting to Standing Position
Introduction: Most people in modern societies spend the majority of their time sitting. However, sagittal spinal alignment is usually analyzed in the standing position. For understanding the symptoms associated with postural changes, this alignment is better to be analyzed in various positions. The purpose of this study was to investigate lumbo-pelvic relationships between standing up and sitting (sit-to-stand) motion.
Methods: The study subjects were 25 healthy young adult volunteers without any spinal symptoms. The following parameters were measured, namely, intervertebral range of motion (IV ROM), lumbar lordotic angle (L1L5), sacral slope (SS), pelvic tilt (PT), and pelvic incidence (PI), on lateral whole-spine radiographs while sitting upright, sitting anterior flexed (anteflexed), standing anteflexed, and standing upright.
Results: The measurements of spinopelvic parameters during sit-to-stand motion (sitting upright, sitting anteflexed, standing anteflexed, standing upright, respectively) were as follows: L1L5 (7.9, −4.4, 3.1, 31.9) and PT (31.5, 26.5, 11.9, 7.7). Regarding IV ROM, the lumbar segmental ROM after seat-off was wider than before seat-off (sitting anteflexed). In particular, the L4-L5 segments had a wide ROM from standing anteflexed to standing upright.
Conclusions: The pelvis was retroverted in the sitting upright position and gradually anteverted during sit-to-stand motion. Lumbar lordosis decreased in the sitting upright position, temporarily decreased further (sitting anteflexed), and then increased in the standing position (standing anteflexed and standing upright). The mechanical loads on lumbosacral segments were greater after seat-off due to the reverse movement between upper lumbar and pelvic segments
Discovery of 2,6-Dihalopurines as Stomata Opening Inhibitors: Implication of an LRX-mediated H+-ATPase Phosphorylation Pathway
Stomata are pores in the leaf epidermis of plants and their opening and closing regulate gas exchange and water transpiration. Stomatal movements play key roles in both plant growth and stress responses. In recent years, small molecules regulating stomatal movements have been used as a powerful tool in mechanistic studies, as well as key players for agricultural applications. Therefore, the development of new molecules regulating stomatal movement and the elucidation of their mechanisms have attracted much attention. We herein describe the discovery of 2,6-dihalopurines, AUs, as a new stomatal opening inhibitor, and their mechanistic study. Based on biological assays, AUs may involve in the pathway related with plasma membrane H+-ATPase phosphorylation. In addition, we identified leucine-rich repeat extensin proteins (LRXs), LRX3, LRX4 and LRX5 as well as RALF, as target protein candidates of AUs by affinity based pull down assay and molecular dynamics simulation. The mechanism of stomatal movement related with the LRXs–RALF is an unexplored pathway, and therefore further studies may lead to the discovery of new signaling pathways and regulatory factors in the stomatal movement
Salvage carbon ion radiotherapy for recurrent solitary fibrous tumor: A case report and literature review
Background:Malignant solitary fibrous tumor (MSFT) arising from the spinal cord is extremely rare and poorly understood mesenchymal neoplasms: only a few MSFT in the spinal canal has been described. We describe the clinical course of the patient with MSFT arising from the thoracic spinal cord.Case report:We describe the clinical course of the patient and the radiological and pathological findings of the tumor. The tumor had been resected by microscopic posterior approach and video-assisted thoracic surgery, but local recurrence was observed by MRI at 1-year follow-up period. No metastatic lesion was confirmed. Then, carbon ion radiotherapy (CIRT) was administered to the recurrent lesion. Local suppression has been observed for 40 months after irradiation.Conclusion:Dumbbell-shaped MSFT arising from thoracic spinal cord is a highly unusual presentation. CIRT might be effective for treatment of recurrent tumors
The Respiratory Adjusted Shock Index at Admission Is a Valuable Predictor of In-Hospital Outcomes for Elderly Emergency Patients with Medical Diseases at a Japanese Community General Hospital
Background: The respiratory adjusted shock index (RASI) is a risk score whose usefulness in patients with sepsis and trauma has previously been reported. However, its relevance in elderly emergency patients with medical diseases is yet to be clarified. This study assessed the usefulness of the RASI, which can be evaluated without requiring special equipment, to provide objective and rapid emergency responses. Methods: In this retrospective study, we recruited patients with medical diseases, aged 65 years or older, who were transported to the emergency room from Tokushima Prefectural Kaifu Hospital and underwent arterial blood gas testing from 1 January 2022 to 31 December 2023. We investigated the association of the RASI with other indices, including the lactate level, National Early Warning Score 2 (NEWS2), Shock Index (SI), Sequential Organ Failure Assessment (SOFA) score, quick SOFA (qSOFA) score, and systemic inflammatory response syndrome (SIRS). Results: In this study, we included 260 patients (mean age, 86 years), of whom 234 were admitted to the hospital; 27 and 49 patients died within 7 and 30 days of admission, respectively. The RASI was positively correlated with the lactate level, NEWS2, SI, and increase in the SOFA score (p < 0.001). The RASI was higher in patients with a SIRS or qSOFA score ≥ 2 than in those without (p < 0.001). It predicted death within 7 and 30 days of admission with an area under the curve (AUC) of 0.80 (95% confidence interval [CI]: 0.73–0.87), sensitivity of 96.3%, and specificity of 53.6% when the cutoff value was set to 1.58 and with an AUC of 0.73 (95% CI: 0.66–0.81), sensitivity of 69.4%, and specificity of 70.6% when the cutoff value was set to 1.83, respectively. Conclusions: The RASI is a simple indicator that can be used for predicting in-hospital outcomes in elderly emergency patients with medical diseases. Larger prospective studies based on this study are needed