Age and Post-Lobectomy Recurrence after Endoscopic or Robotic Thyroid Surgery: A Retrospective Cohort Study of 2348 Papillary Thyroid Carcinoma Patients.

The biology of papillary thyroid carcinoma (PTC) in young patients is poorly understood, and there are conflicting data regarding the recurrence for younger patients compared to older patients. We retrospectively analyzed 2348 clinically node-negative (cN0) PTC patients who underwent a thyroid lobectomy between 2008 and 2017. Young age was defined as less than 35 years old. The clinicopathological characteristics and oncologic outcomes of the young age group were compared to those of the older age group. The number of young age cN0 PTC patients accounted for 20.7% of the enrolled patients, and 24.2% were upstaged into pathologic N1a. The young age group had a significantly larger proportion of females, endoscopic/robotic thyroid lobectomies, stage N1a, and larger tumor sizes. Post-lobectomy recurrences were significantly higher in the young age group. In the Cox analysis, young age, large tumor size, and stage N1a were significant risk factors. The multivariate analysis reveals that young age and stage N1a are significant risk factors. Conversely, minimally invasive or robot-endoscopic thyroidectomies were not risk factors for post-lobectomy recurrence compared to conventional thyroidectomies. While young patients with a stage N1a had a significant risk factor for post-lobectomy recurrence, endoscopic/robotic thyroidectomy was as feasible and safe as conventional thyroidectomies in the median seven-year oncologic follow-up. Further high-quality studies are needed to elucidate the relationship between age and the risk of post-lobectomy recurrence.

Unilateral Multifocality Is Not a Risk Factor for Recurrence After Thyroid Lobectomy: A Study of 1,684 Patients With Differentiated Thyroid Cancer.

BACKGROUND/AIM: Many studies indicate that multifocality is associated with high-risk features of differentiated thyroid cancer (DTC). Herein, we evaluated the impact of the unilateral multifocality on post-lobectomy recurrence in patients with DTC. PATIENTS AND METHODS: We retrospectively analyzed 1,684 patients with DTC who underwent thyroid lobectomy from 2008 to 2015 using logistic regression models to calculate the relative risk on post-lobectomy recurrence. RESULTS: Tumor diameter increased from 4.9 mm to 8.1 mm and the proportion of extrathyroidal extension (ETE) and unilateral multifocality progressively increased from 2008 to 2015 (2.1% to 24.3% and 4.2% to 22.8%, respectively). During the 88.6-month follow-up period, 67 (3.98%) recurrences and 2 (0.12%) deaths were observed. There were 269 (16.0%) multifocal DTC cases. There was no significant difference between the multifocal and unifocal groups in terms of the proportion of recurrences (5.2% vs. 3.7%) and distant metastasis (0.4% vs. 0.1%). Logistic regression analysis revealed age <42.5 years (OR=1.83), tumor diameter greater than 7.5 mm (OR=1.89), and N1a (OR=2.04) were potent risk factors for post-lobectomy recurrence. Conversely, male sex (OR=0.77; p=0.407), ETE (OR=1.16; p=0.698) and multifocality (OR=1.23; p=0.526) were not risk factors for recurrence after thyroid lobectomy. A positive node ratio (PNR) ≥42.0%, N1a stage, a tumor diameter ≥7.5mm and age <42.5 years were significant risk factors for recurrence (Log-rank p=0.001, p=0.001, p=0.004 and p=0.009, respectively). Contrariwise, multifocality and ETE were proven to not be risk factors for DTC recurrence after thyroid lobectomy (Log-rank p=0.099 and p=0.126, respectively). CONCLUSION: Unilateral multifocality was not a risk factor for DTC recurrence after thyroid lobectomy and could not be considered an indication for immediate completion or total thyroidectomy.

Comparative functional analysis of PdeNAC2 and AtVND6 in the tracheary element formation.

Tracheary elements (i.e. vessel elements and tracheids) are highly specialized, non-living cells present in the water-conducting xylem tissue. In angiosperms, proteins in the VASCULAR-RELATED NAC-DOMAIN (VND) subgroup of the NAC (NAM, ATAF1,2, and CUC2) transcription factor family (e.g. AtVND6) are required for the differentiation of vessel elements through transcriptional regulation of genes responsible for secondary cell wall formation and programmed cell death. Gymnosperms, however, produce only tracheids, the mechanism of which remains elusive. Here, we report functional characteristics of PdeNAC2, a VND homolog in Pinus densiflora, as a key regulator of tracheid formation. Interestingly, our molecular genetic analyses show that PdeNAC2 can induce the formation of vessel element-like cells in angiosperm plants, demonstrated by transgenic overexpression of either native or NAC domain-swapped synthetic genes of PdeNAC2 and AtVND6 in both Arabidopsis and hybrid poplar. Subsequently, genome-wide identification of direct target (DT) genes of PdeNAC2 and AtVND6 revealed 138 and 174 genes as putative DTs, respectively, but only 17 genes were identified as common DTs. Further analyses have found that PdeNAC2 does not control some AtVND6-dependent vessel differentiation genes in angiosperm plants, such as AtVRLK1, LBD15/30 and pit-forming Rho-like GTPases from plant (ROP) signaling genes. Collectively, our results suggest that different target gene repertoires of PdeNAC2 and AtVND6 may contribute to the evolution of tracheary elements.

Thyroglobulin Levels as a Predictor of Papillary Cancer Recurrence After Thyroid Lobectomy.

BACKGROUND/AIM: The effectiveness of using serum thyroglobulin (TG) to predict thyroid cancer recurrence after a thyroid lobectomy is unknown. This study aimed to evaluate the predictive nature of serum TG and TG trends after thyroid lobectomies. PATIENTS AND METHODS: We analyzed 514 papillary thyroid cancer (PTC) patients. The pre-, low-, high, and last-TG levels were reviewed and stratified into three groups. An ascending TG trend was defined if the last-TG level was more than 200% as high as the value of low-TG level. A descending trend was defined if the last-TG level decreased by more than 50% and a flat trend as between them. RESULTS: During a median follow-up period of 73.0 months, there were 21 (4.1%) recurrences. Most patients showed a descending (54.1%) or flat (35.6%) TG trend, but 10.3% of patients showed an ascending TG trend. Overall and lateral recurrences were significantly higher in the ascending TG group, indicating that an ascending TG trend was a good predictor for recurrence. Other factors such as positive node ratio (PNR), patient risk, age, and sex were not significant risk factors. In a Kaplan-Meier analysis, ascending TG trend was a good predictor of lateral recurrence. CONCLUSION: TG levels as a predictor of papillary cancer recurrence after thyroid lobectomy were found to be poor classifiers, and optimal cut-off values were not verified. An ascending TG trend was a good predictor of lateral recurrence. Further studies are warranted to investigate whether an ascending TG trend was due to an incomplete thyroid lobectomy or if the cancer had already metastasized to the lateral compartment.

Numerical and Experimental Investigation of Quasi-Static Crushing Behaviors of Steel Tubular Structures.

In this study, a numerical and experimental investigation of the quasi-static crushing behavior of steel tubular structures was conducted. As the crushing failure behavior involves a high level of nonlinearity for the numerical simulations, these were compared with previous experimental works, including crushing tests of steel square tubes to calibrate the numerical results. Six parameters for the numerical simulations, namely (1) loading boundary condition, (2) geometrical imperfection, (3) friction coefficient, (4) element size, (5) element type, and (6) material nonlinearity model, were examined using a series of finite element analyses. Through the sensitivity study for each parameter, the deformation and crushing load of the steel tube were investigated, and the value that best matched the experimental results was selected. The results of the numerical analysis for the determined model were compared with the experimental results. Finally, the authors provided recommendations that should be considered when performing nonlinear finite element simulations of crushing failure events.

Disaster Response to a Mass Casualty Incident in a Hospital Fire by Regional Disaster Medical Assistance Team: Characteristics of Hospital Fire.

OBJECTIVE: A disaster in the hospital is particularly serious and quite different from other ordinary disasters. This study aimed at analyzing the activity outcomes of a disaster medical assistance team (DMAT) for a fire disaster at the hospital. METHODS: The data which was documented by a DMAT and emergent medical technicians of a fire department contained information about the patient's characteristics, medical records, triage results, and the hospital which the patient was transferred from. Patients were categorized into four groups according to results of field triage using the simple triage and rapid treatment method. RESULTS: DMAT arrived on the scene in 37 minutes. One hundred and thirty eight (138) patients were evacuated from the disaster scene. There were 25 patients (18.1%) in the Red group, 96 patients (69.6%) in the Yellow group, and 1 patient (0.7%) in the Green group. One patient died. There were 16 (11.6%) medical staff and hospital employees. The injury of the caregiver or the medical staff was more severe compared to the family protector. CONCLUSIONS: For an effective disaster-response system in hospital disasters, it is important to secure the safety of medical staff, to utilize available medical resources, to secure patients' medical records, and to reorganize the DMAT dispatch system.

Levothyroxine Cessation After Thyroid Lobectomy for Papillary Thyroid Cancer Can Be Achieved at the Same Rate as that for Benign Tumors Regardless of the Duration of Thyroid-stimulating Hormone Suppression.

BACKGROUND/AIM: Thyroid lobectomy may cause post-lobectomy hypothyroidism. We investigated the difference in levothyroxine (LT4) supplementation and cessation between patients with benign disease and those with papillary thyroid carcinoma (PTC) and found that the rate of LT4 cessation could be decreased after thyroid-stimulating hormone (TSH) suppression in PTC. PATIENTS AND METHODS: We retrospectively reviewed 88 patients with benign tumor and 463 patients with PTC and investigated the risk factors for LT4 supplementation after thyroid lobectomy. RESULTS: During the median follow-up of 73.0 months, 207 (37.6%) patients maintained the euthyroid state, while 344 (62.4%) patients continued LT4 supplementation for LT4 replacement or TSH suppression. In patients with benign tumors, only high pre-TSH level (>1.98 mIU/l) was a significant risk factor (odds ratio [OR]=10.09). However, in patients with PTC, pre-TSH level ≥1.98 mIU/l (OR=3.28), pregnancy planning (OR=2.97), and age ≥42.5 years (OR=1.94) were significant risk factors. Moreover, the most potent risk factor was tumor aggressiveness (OR=4.00), which was found to be more significant than high pre-TSH. The overall rate of LT4 cessation in all patients was 37.6%; however, in the 303 patients who underwent the LT4-Off trial, there was no difference in the rate in the benign tumor, low-risk PTC, and intermediate-risk PTC groups (66.2%, 68.8%, and 70.8%, respectively; p=0.886). CONCLUSION: When post-lobectomy TSH levels were adequate and the risk of recurrence was reduced, LT4 cessation in PTC could be achieved at the same rate as that in benign tumors, regardless of the duration of TSH suppression.

Field evaluation of transgenic hybrid poplars with desirable wood properties and enhanced growth for biofuel production by bicistronic expression of PdGA20ox1 and PtrMYB3 in wood-forming tissue.

BACKGROUND: To create an ideotype woody bioenergy crop with desirable growth and biomass properties, we utilized the viral 2A-meidated bicistronic expression strategy to express both PtrMYB3 (MYB46 ortholog of Populus trichocarpa, a master regulator of secondary wall biosynthesis) and PdGA20ox1 (a GA20-oxidase from Pinus densiflora that produces gibberellins) in wood-forming tissue (i.e., developing xylem). RESULTS: Transgenic Arabidopsis plants expressing the gene construct DX15::PdGA20ox1-2A-PtrMYB3 showed a significant increase in both stem fresh weight (threefold) and secondary wall thickening (1.27-fold) relative to wild-type (WT) plants. Transgenic poplars harboring the same gene construct grown in a greenhouse for 60 days had a stem fresh weight up to 2.6-fold greater than that of WT plants. In a living modified organism (LMO) field test conducted for 3 months of active growing season, the stem height and diameter growth of the transgenic poplars were 1.7- and 1.6-fold higher than those of WT plants, respectively, with minimal adverse growth defects. Although no significant changes in secondary wall thickening of the stem tissue of the transgenic poplars were observed, cellulose content was increased up to 14.4 wt% compared to WT, resulting in improved saccharification efficiency of the transgenic poplars. Moreover, enhanced woody biomass production by the transgenic poplars was further validated by re-planting in the same LMO field for additional two growing seasons. CONCLUSIONS: Taken together, these results show considerably enhanced wood formation of our transgenic poplars, with improved wood quality for biofuel production.

PtrMYB120 functions as a positive regulator of both anthocyanin and lignin biosynthetic pathway in a hybrid poplar.

Both anthocyanins and lignins are essential secondary metabolites in plant growth and development. Their biosynthesis is metabolically interconnected and diverges in the central metabolite 4-coumaroyl CoA of the phenylpropanoid pathway. Considerable progress has been made in understanding transcriptional regulation of genes involved in lignin and anthocyanin synthesis pathways, but the concerted regulation of these pathways is not yet fully understood. Here, we functionally characterized PtrMYB120, a R2R3-MYB transcription factor from Populus trichocarpa. Overexpression of PtrMYB120 in a hybrid poplar (i.e., 35S::PtrMYB120) was associated with increased anthocyanin (i.e., cyanidin 3-O-glucoside) accumulation and upregulation of anthocyanin biosynthetic genes. However, transgenic poplars with dominant suppression of PtrMYB120 function achieved by fusing the ERF-associated amphiphilic repression motif to PtrMYB120 (i.e., 35S::PtrMYB120-SRDX) had a dramatic decrease in not only anthocyanin but also Klason lignin content with downregulation of both anthocyanin and lignin biosynthetic genes. Indeed, 35S::PtrMYB120-SRDX poplars had irregularly shaped xylem vessels with reduced S-lignin content in stems, which was proportionally related to the level of the introduced PtrMYB120-SRDX gene. Furthermore, protoplast-based transcriptional activation assay using the PtrMYB120-GR system suggested that PtrMYB120 directly regulates genes involved in both anthocyanin and lignin biosynthesis, including chalcone synthase and ferulate-5 hydroxylase. Interestingly, the saccharification efficiency of line #6 of 35S::PtrMYB120-SRDX poplars, which had slightly reduced lignin content with a normal growth phenotype, was dramatically enhanced (>45%) by NaOH treatment. Taken together, our results suggest that PtrMYB120 functions as a positive regulator of both anthocyanin and lignin biosynthetic pathways and can be targeted to enhance saccharification efficiency in woody perennials.

Wood transcriptome analysis of Pinus densiflora identifies genes critical for secondary cell wall formation and NAC transcription factors involved in tracheid formation.

Although conifers have significant ecological and economic value, information on transcriptional regulation of wood formation in conifers is still limited. Here, to gain insight into secondary cell wall (SCW) biosynthesis and tracheid formation in conifers, we performed wood tissue-specific transcriptome analyses of Pinus densiflora (Korean red pine) using RNA sequencing. In addition, to obtain full-length transcriptome information, PacBio single molecule real-time iso-sequencing was carried out using RNAs from 28 tissues of P. densiflora. Subsequent comparative tissue-specific transcriptome analysis successfully pinpointed critical genes encoding key proteins involved in biosynthesis of the major secondary wall components (cellulose, galactoglucomannan, xylan and lignin). Furthermore, we predicted a total of 62 NAC (NAM, ATAF1/2 and CUC2) family transcription factor members and identified seven PdeNAC genes preferentially expressed in developing xylem tissues in P. densiflora. Protoplast-based transcriptional activation analysis found that four PdeNAC genes, homologous to VND, NST and SND/ANAC075, upregulated GUS activity driven by an SCW-specific cellulose synthase promoter. Consistently, transient overexpression of the four PdeNACs induced xylem vessel cell-like SCW deposition in both tobacco (Nicotiana benthamiana) and Arabidopsis leaves. Taken together, our data provide a foundation for further research to unravel transcriptional regulation of wood formation in conifers, especially SCW formation and tracheid differentiation.

Survival and Rearrest in out-of-Hospital Cardiac Arrest Patients with Prehospital Return of Spontaneous Circulation: A Prospective Multi-Regional Observational Study.

OBJECTIVE: We aimed to determine the factors associated with rearrest after prehospital return of spontaneous circulation (ROSC) and examine the factors associated with survival despite rearrest. METHODS: We conducted a prospective multi-regional observational study of out-of-hospital cardiac arrest (OHCA) patients between August 2015 and July 2016. Patients received prehospital advanced cardiovascular life support performed by emergency medical technicians (EMTs). EMTs were directly supervised by medical directors (physicians) via real-time smartphone video calls [Smart Advanced Life Support (SALS)]. The study participants were categorized into rearrest (+) and rearrest (-) groups depending on whether rearrest occurred after prehospital ROSC. After rearrest, patients were further classified as survivors or non-survivors at discharge. RESULTS: SALS was performed in 1,711 OHCA patients. Prehospital ROSC occurred in 345 patients (20.2%); of these patients, 189 (54.8%) experienced rearrest [rearrest (+) group] and 156 did not experience rearrest [rearrest (-) group]. Multivariate analysis showed that a longer interval from collapse to first prehospital ROSC was independently associated with rearrest [odds ratio (OR) 1.081; 95% confidence interval (CI) 1.050-1.114]. The presence of an initial shockable rhythm was independently associated with survival after rearrest (OR 6.920; 95% CI 2.749-17.422). As a predictor of rearrest, the interval from collapse to first prehospital ROSC (cut-off: 24 min) had a sensitivity of 77% and a specificity of 54% (AUC = 0.715 [95% CI 0.661-0.769]). CONCLUSIONS: A longer interval from collapse to first prehospital ROSC was associated with rearrest, and an initial shockable rhythm was associated with survival despite the occurrence of rearrest. Emergency medical service providers and physicians should be prepared to deal with rearrest when pulses are obtained late in the resuscitation.

Overexpression of a Poplar RING-H2 Zinc Finger, Ptxerico, Confers Enhanced Drought Tolerance via Reduced Water Loss and Ion Leakage in Populus.

Drought stress is one of the major environmental problems in the growth of crops and woody perennials, but it is getting worse due to the global climate crisis. XERICO, a RING (Really Interesting New Gene) zinc-finger E3 ubiquitin ligase, has been shown to be a positive regulator of drought tolerance in plants through the control of abscisic acid (ABA) homeostasis. We characterized a poplar (Populus trichocarpa) RING protein family and identified the closest homolog of XERICO called PtXERICO. Expression of PtXERICO is induced by both salt and drought stress, and by ABA treatment in poplars. Overexpression of PtXERICO in Arabidopsis confers salt and ABA hypersensitivity in young seedlings, and enhances drought tolerance by decreasing transpirational water loss. Consistently, transgenic hybrid poplars overexpressing PtXERICO demonstrate enhanced drought tolerance with reduced transpirational water loss and ion leakage. Subsequent upregulation of genes involved in the ABA homeostasis and drought response was confirmed in both transgenic Arabidopsis and poplars. Taken together, our results suggest that PtXERICO will serve as a focal point to improve drought tolerance of woody perennials.

Effect of alcohol intake on the severity of injuries caused by slipping down.

OBJECTIVE: Alcohol consumption is associated with an increased risk of injuries. However, its effects on injury severity and mortality remain unclear. Specifically, the effects of alcohol intake on the severity of slip injuries have not been thoroughly investigated. Therefore, our study aimed to investigate the effects of alcohol intake on injury patterns and severity in patients experiencing slip injuries. METHODS: Emergency department surveillance data collected from 2011 to 2016 were analyzed for this study. Among patients aged 15 and older who were admitted for slip injuries, we compared the type and severity of injuries between the alcohol-intake group and the no-alcohol-intake group. Injury severity was classified as non-severe and severe based on the excess mortality ratio-adjusted injury severity score. RESULTS: In total, 227,548 (alcohol-intake, n=48,581; no-alcohol-intake, n=178,967) patients were included. After adjusting for age, time of injury, use of public ambulance, and season, multivariate logistic regression analysis showed that injuries were more likely to be severe in the alcohol-intake group than in the no-alcohol-intake group (odds ratio, 1.60; 95% confidence interval, 1.47-1.75). In addition, male gender and alcohol consumption had a greater synergistic effect on injury severity than the mere sum of each effect of these factors (odds ratio, 2.65; 95% confidence interval, 2.53-2.78). CONCLUSION: Assessment of the patients influenced by alcohol was a challenge in the emergency department due to altered mental status. We suggest a considerate approach in testing and assessing male patients who slipped after alcohol-intake in the emergency department.

Overexpression of Populus transcription factor PtrTALE12 increases axillary shoot development by regulating WUSCHEL expression.

The TALE (Three Amino acid Loop Extension) transcription factor family has been shown to control meristem formation and organogenesis in plants. To understand the functional roles of the TALE family in woody perennials, each of the TALE members of Populus trichocarpa was overexpressed in Arabidopsis as a proxy. Among them, the overexpression of PtrTALE12 (i.e., 35S::PtrTALE12) resulted in a dramatic increase of axillary shoot development with early flowering. Interestingly, expression of WUSCHEL (WUS), a central regulator of both apical and axillary meristem formation, was significantly increased in the 35S::PtrTALE12 Arabidopsis plants. Conversely, WUS expression was downregulated in 35S::PtrTALE12-SRDX (short transcriptional repressor domain) plants. Further analysis found that PtrTALE12, expressed preferentially in meristem tissues, directly regulates WUS expression in transient activation assays using Arabidopsis leaf protoplast. Yeast two-hybrid assays showed that PtrTALE12 interacts with SHOOT MERISTEMLESS (STM); however, the interaction does not affect the WUS expression. In addition, expression of both CIRCADIAN CLOCK ASSOCIATED1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY) genes was suppressed accordingly for early flowering 35S::PtrTALE12 Arabidopsis. Indeed, transgenic poplars overexpressing PtrTALE12 as well as Arabidopsis plants overexpressing AtBLH11, a close homolog of PtrTALE12, phenocopied the 35S::PtrTALE12 Arabidopsis (i.e., increased axillary shoot development). Taken together, our results suggest that PtrTALE12 functions as a positive regulator of axillary shoot formation in both Arabidopsis and poplar.

Can helmet decrease mortality of craniocerebral trauma patients in a motorcycle accident?: A propensity score matching.

A helmet is critical for preventing head injuries during motorcycle accidents. However, South Korean motorcyclists have a lower prevalence of wearing a helmet, compared to developed countries. Therefore, we aimed to evaluate whether helmet wearing was associated with the clinical outcomes in Korean motorcycle accidents. Data were obtained from the Emergency Department-based Injury In-depth Surveillance database 2011-2015. We considered the patients had experienced a motorcycle accident and were only diagnosed with a craniocerebral trauma (CCT). The primary outcome was mortality and the secondary outcomes were the severity and hospitalization duration. The patients were separated whether they were wearing a helmet and the outcomes were compared using multivariate logistic regression after propensity score matching (PSM). Among 1,254,250 patients in the database, 2,549 patients were included. After PSM, 1,016 patients in each group were matched. The univariate analyses revealed that helmet wearing was associated with lesser severity (P < 0.001) and shorter hospitalization (P < 0.001). The regression analysis revealed that mortality was also lower in a helmet-wearing group (odds ratio: 0.34, 95% confidence interval: 0.21-0.56). In conclusion, wearing a helmet may reduce the mortality from a CCT after a motorcycle accident and associated with lesser severity and shorter hospitalization.

Relationship between age and injury severity in traffic accidents involving elderly pedestrians.

OBJECTIVE: This study aimed to examine whether injury severity differs with respect to age among elderly pedestrians involved in traffic accidents and identify factors affecting injury severity. METHODS: Using emergency department-based injury in-depth surveillance data, we analyzed the data of patients aged ≥60 years who were victims of pedestrian traffic accidents during 2011 to 2016. The pedestrians' ages were divided into 5-year age strata beginning at 60 years. In a multivariate analysis, injury severity was classified as severe to critical or mild to moderate. RESULTS: The analysis included 10,449 patients. All age groups had a female predominance, and accidents most frequently occurred during the early morning. Multivariate analyses revealed that compared to the 60 to 64 years group, the odds ratios for incurring a severe injury were 1.18 (95% confidence interval [CI], 1.02 to 1.37) for the 65 to 69 years group, 1.42 (95% CI, 1.23 to 1.64) for the 70 to 74 years group, 1.70 (95% CI, 1.45 to 1.98) for the 75 to 79 years group, and 1.83 (95% CI, 1.56 to 2.15) for the ≥80 years group. CONCLUSION: In this study of emergency department-based data, we found that injury severity increased with age among elderly victims of traffic accidents. Furthermore, injury severity varied with respect to sex, time and location of the accident, and type of vehicle involved. Therefore, measures intended to reduce and prevent traffic accidents involving elderly pedestrians should consider these findings.

Wood Transcriptome Profiling Identifies Critical Pathway Genes of Secondary Wall Biosynthesis and Novel Regulators for Vascular Cambium Development in Populus.

Wood, the most abundant biomass on Earth, is composed of secondary xylem differentiated from vascular cambium. However, the underlying molecular mechanisms of wood formation remain largely unclear. To gain insight into wood formation, we performed a series of wood-forming tissue-specific transcriptome analyses from a hybrid poplar (Populus alba × P. glandulosa, clone BH) using RNA-seq. Together with shoot apex and leaf tissue, cambium and xylem tissues were isolated from vertical stem segments representing a gradient of secondary growth developmental stages (i.e., immature, intermediate, and mature stem). In a comparative transcriptome analysis of the 'developing xylem' and 'leaf' tissue, we could identify critical players catalyzing each biosynthetic step of secondary wall components (e.g., cellulose, xylan, and lignin). Several candidate genes involved in the initiation of vascular cambium formation were found via a co-expression network analysis using abundantly expressed genes in the 'intermediate stem-derived cambium' tissue. We found that transgenic Arabidopsis plants overexpressing the PtrHAM4-1, a GRAS family transcription factor, resulted in a significant increase of vascular cambium development. This phenotype was successfully reproduced in the transgenic poplars overexpressing the PtrHAM4-1. Taken together, our results may serve as a springboard for further research to unravel the molecular mechanism of wood formation, one of the most important biological processes on this planet.

Wood forming tissue-specific bicistronic expression of PdGA20ox1 and PtrMYB221 improves both the quality and quantity of woody biomass production in a hybrid poplar.

With the exponential growth of the human population and industrial developments, research on renewable energy resources is required to alleviate environmental and economic impacts caused by the consumption of fossil fuels. In this study, we present a synthetic biological application of a wood forming tissue-specific bicistronic gene expression system to improve both the quantity and quality of woody biomass to minimize undesirable growth penalties. Our transgenic poplars, designed to express both PdGA20ox1 (a GA20-oxidase from Pinus densiflora producing bioactive gibberellin, GA) and PtrMYB221 (a MYB transcription factor negatively regulating lignin biosynthesis) under the developing xylem (DX) tissue-specific promoter (i.e., DX15::PdGA20ox1-2A-PtrMYB221 poplar), resulted in a 2-fold increase in biomass quantity compared to wild-type (WT), without undesirable growth defects. A similar phenotype was observed in transgenic Arabidopsis plants harboring the same gene constructs. These phenotypic consequences were further verified in the field experiments. Importantly, our transgenic poplars exhibited an improved quality of biomass with reduced lignin content (~16.0 wt%) but increased holocellulose content (~6.6 wt%). Furthermore, the saccharification efficiency of our transgenic poplar increased significantly by up to 8%. Our results demonstrate that the controlled production of both GA and a secondary wall modifying regulator in the same spatio-temporal manner can be utilized as an efficient biotechnological tool for producing the desired multi-purpose woody biomass.

Poplar MYB transcription factor PtrMYB012 and its Arabidopsis AtGAMYB orthologs are differentially repressed by the Arabidopsis miR159 family.

A phenotype-based screening of the T1 transgenic Arabidopsis population transformed by overexpression constructs of the entire poplar MYB transcription factor family found that overexpression of a poplar MYB transcription factor, PtrMYB012, in Arabidopsis resulted in upwardly curled rosette leaves, dwarfism and male sterility. Sequence analysis identified that PtrMYB012 is homologous to the Arabidopsis GAMYB genes (e.g., AtMYB65 and AtMYB33). Gene expression analysis revealed that PtrMYB012 is specifically expressed in floral tissues, especially in male catkins, similar to AtMYB65. It was well known that Arabidopsis GAMYBs are negatively regulated by microRNA159 (miR159) during vegetative growth; thus, the typical phenotypes of upwardly curled leaves, dwarfism and male sterility were only shown in overexpression of GAMYBs with mutations in the miR159 target sequence. To confirm our phenotypic consequences, we independently re-produced transgenic Arabidopsis plants overexpressing PtrMYB012 without mutations in the miR159 target sequence. The resulting 35 S::PtrMYB012 Arabidopsis plants phenocopied the previous transgenic Arabidopsis plants, suggesting that PtrMYB012 is probably not a target of Arabidopsis miR159 despite containing the conserved miR159 target sequence. To gain further insight, we produced transgenic poplars overexpressing the intact PtrMYB012. As a result, no conspicuous phenotype was found in 35 S::PtrMYB012 poplar plants. These results suggest that PtrMYB012 transcripts are down-regulated by miR159 in poplar but not in Arabidopsis. Indeed, subsequent 5'-RACE analysis confirmed that PtrMYB012 transcripts are completely degraded in poplar, probably by miR159, but not in Arabidopsis. These results suggest that species-specific family members of miR159 are important for the regulation of normal growth and development in plants.

Changes to the Korean Disaster Medical Assistance System After Numerous Multi-casualty Incidents in 2014 and 2015.

OBJECTIVE: A number of multiple-casualty incidents during 2014 and 2015 brought changes to Korea's disaster medical assistance system. We report these changes here. METHODS: Reports about these incidents, revisions to laws, and the government's revised medical disaster response guidelines were reviewed. RESULTS: The number of DMAT (Disaster Medical Assistance Team) staff members was reduced to 4 from 8, and the mobilization method changed. An emergency response manual was created that contains the main content of the DMAT, and there is now a DMAT training program to educate staff. The government created and launched a national 24-hour Disaster Emergency Medical Service Situation Room, and instead of the traditional wireless communications, mobile instant smart phone messaging has been added as a new means of communication. The number of disaster base hospitals has also been doubled. CONCLUSION: Although there are still limitations that need to be remedied, the changes to the current emergency medical assistance system are expected to improve the system's response capacity. (Disaster Med Public Health Preparedness. 2017;11:526-530).