Ontogenetic changes in root and shoot respiration, fresh mass and surface area of Fagus crenata.

BACKGROUND AND AIMS: To date, studies on terrestrial plant ecology and evolution have focused primarily on the trade-off patterns in the allocation of metabolic production to roots and shoots in individual plants and the scaling of whole-plant respiration. However, few empirical studies have investigated the root : shoot ratio by considering scaling whole-plant respiration at various sizes throughout ontogeny. METHODS: Here, using a whole-plant chamber system, we measured the respiration rates, fresh mass and surface area of entire roots and shoots from 377 Fagus crenata individuals, from germinating seeds to mature trees, collected from five different Japanese provenances. Non-linear regression analysis was performed for scaling of root and shoot respiration, fresh mass and surface area with body size. KEY RESULTS: Whole-plant respiration increased rapidly in germinating seeds. In the seedling to mature tree size range, the scaling of whole-plant respiration to whole-plant fresh mass was expressed as a linear trend on the log-log coordinates (exponent slightly greater than 0.75). In the same body size range, root and shoot respiration vs. whole-plant fresh mass were modelled by upward-convex (exponent decreased from 2.35 to 0.638) and downward-convex trends (exponent increased from -0.918 to 0.864), respectively. The root fraction in whole-plant respiration, fresh mass and surface area shifted continuously throughout ontogeny, increasing in smaller seedlings during early growth stages and decreasing in larger trees. CONCLUSIONS: Our results suggest a gradual shift in allocation priorities of metabolic energy from roots in seedlings to shoots in mature trees, providing insights into how roots contribute to shoot and whole-plant growth during ontogeny. The models of root : shoot ratio in relation to whole-plant physiology could be applied in tree growth modelling, and in linking the different levels of ecological phenomena, from individuals to ecosystems.

Generating polyketide diversity in Dictyostelium: a Steely hybrid polyketide synthase produces alternate products at different developmental stages.

The soil is a rich ecosystem where many ecological interactions are mediated by small molecules, and in which amoebae are low-level predators and also prey. The social amoeba Dictyostelium discoideum has a high genomic potential for producing polyketides to mediate its ecological interactions, including the unique 'Steely' enzymes, consisting of a fusion between a fatty acid synthase and a chalcone synthase. We report here that D. discoideum further increases its polyketide potential by using the StlB Steely enzyme, and a downstream chlorinating enzyme, to make both a chlorinated signal molecule, DIF-1, during its multi-cellular development, and a set of abundant polyketides in terminally differentiated stalk cells. We identify one of these as a chlorinated dibenzofuran with potent anti-bacterial activity. To do this, StlB switches expression from prespore to stalk cells in late development and is cleaved to release the chalcone synthase domain. Expression of this domain alone in StlB null cells allows synthesis of the stalk-associated, chlorinated polyketides. Thus, by altered expression and processing of StlB, cells make first a signal molecule, and then abundant secondary metabolites, which we speculate help to protect the mature spores from bacterial infection.

Scaling the leaf length-times-width equation to predict total leaf area of shoots.

BACKGROUND AND AIMS: An individual plant consists of different-sized shoots, each of which consists of different-sized leaves. To predict plant-level physiological responses from the responses of individual leaves, modelling this within-shoot leaf size variation is necessary. Within-plant leaf trait variation has been well investigated in canopy photosynthesis models but less so in plant allometry. Therefore, integration of these two different approaches is needed. METHODS: We focused on an established leaf-level relationship that the area of an individual leaf lamina is proportional to the product of its length and width. The geometric interpretation of this equation is that different-sized leaf laminas from a single species share the same basic form. Based on this shared basic form, we synthesized a new length-times-width equation predicting total shoot leaf area from the collective dimensions of leaves that comprise a shoot. Furthermore, we showed that several previously established empirical relationships, including the allometric relationships between total shoot leaf area, maximum individual leaf length within the shoot and total leaf number of the shoot, can be unified under the same geometric argument. We tested the model predictions using five species, all of which have simple leaves, selected from diverse taxa (Magnoliids, monocots and eudicots) and from different growth forms (trees, erect herbs and rosette herbs). KEY RESULTS: For all five species, the length-times-width equation explained within-species variation of total leaf area of a shoot with high accuracy (R2 > 0.994). These strong relationships existed despite leaf dimensions scaling very differently between species. We also found good support for all derived predictions from the model (R2 > 0.85). CONCLUSIONS: Our model can be incorporated to improve previous models of allometry that do not consider within-shoot size variation of individual leaves, providing a cross-scale linkage between individual leaf-size variation and shoot-size variation.

Acute myocardial infarction with simultaneous total occlusion of the left anterior descending artery and right coronary artery successfully treated with percutaneous coronary intervention.

BACKGROUND: Simultaneous thrombosis in more than one coronary artery is an uncommon angiographic finding in patients with acute ST-segment elevation myocardial infarction. It is difficult to identify using 12-lead electrocardiography and usually leads to cardiogenic shock and fatal outcomes, including sudden cardiac death. Therefore, immediate revascularization and adequate mechanical circulatory support are required. CASE PRESENTATION: We report the case of a 58-year-old man who presented with vomiting and chest pain complicated by cardiogenic shock and complete atrioventricular block. Electrocardiography revealed ST-segment elevation in leads II, III, aVF, and V1-V6. Emergency coronary angiography revealed total occlusion of the proximal left anterior descending artery and right coronary artery. The patient successfully underwent primary percutaneous coronary intervention with ballooning and stenting for both arteries. An Impella CP was inserted during the procedure. Fifty-seven days after admission, he had New York Heart Association class II heart failure and was transferred to a rehabilitation hospital. CONCLUSIONS: Acute double-vessel coronary thrombosis, a serious event with a high mortality rate, requires prompt diagnosis and management to prevent complications such as cardiogenic shock and ventricular arrhythmias. A combination of judicious medical treatment, efficient primary percutaneous coronary intervention, and early mechanical support device insertion is crucial to improve the survival rate of patients with this disease.

Consistent scaling of whole-shoot respiration between Moso bamboo (Phyllostachys pubescens) and trees.

Both Moso bamboo (Phyllostachys pubescens) and tree forests have a large biomass; they are considered to play an important role in ecosystem carbon budgets. The scaling relationship between individual whole-shoot (i.e., aboveground parts) respiration and whole-shoot mass provides a clue for comparing the carbon budgets of Moso bamboo and tree forests. However, nobody has empirically demonstrated whether there is a difference between these forest types in the whole-shoot scaling relationship. We developed whole-shoot chambers and measured the shoot respiration of 58 individual mature bamboo shoots from the smallest to the largest in a Moso bamboo forest, and then compared them with that of 254 tree shoots previously measured. For 30 bamboo shoots, we measured the respiration rate of leaves, branches, and culms. We found that the scaling exponent of whole-shoot respiration of bamboo fitted by a simple power function on a log-log scale was 0.843 (95 % CI 0.797-0.885), which was consistent with that of trees, 0.826 (95 % CI 0.799-0.851), but higher than 3/4, the value typifying the Kleiber's rule. The respiration rates of leaves, branches, and culms at the whole-shoot level were proportional to their mass, revealing a constant mean mass-specific respiration of 1.19, 0.224, and 0.0978 µmol CO2 kg- 1 s- 1, respectively. These constant values suggest common traits of organs among physiologically integrated ramets within a genet. Additionally, the larger the shoots, the smaller the allocation of organ mass to the metabolically active leaves, and the larger the allocation to the metabolically inactive culms. Therefore, these shifts in shoot-mass partitioning to leaves and culms caused a negative metabolic scaling of Moso bamboo shoots. The observed convergent metabolic scaling of Moso bamboo and trees may facilitate comparisons of the ecosystem carbon budgets of Moso bamboo and tree forests.

Effect of orbital atherectomy in calcified coronary artery lesions as assessed by optical coherence tomography.

OBJECTIVES: We sought to assess plaque modification and stent expansion following orbital atherectomy (OA) for calcified lesions using optical coherence tomography (OCT). BACKGROUND: The efficacy of OA for treating calcified lesions is not well studied, especially using intravascular imaging in vivo. METHODS: OCT was performed preprocedure, post-OA, and post-stent (n = 58). Calcium modification after OA was defined as a round, concave, polished calcium surface. Calcium fracture was complete discontinuity of calcium. RESULTS: Comparing pre- vs post-OA OCT (n = 29), calcium area was significantly decreased post-OA (from 3.4 mm2 [2.4-4.7] to 2.9 mm2 [1.9-3.9], P < 0.001). Poststent percent calcium fracture (calcium fracture length/calcium length) correlated with post-OA percent calcium modification (calcium modification length/calcium length) (r = 0.31, P = 0.01). Among 75 calcium fractures in 35 lesions, maximum calcium thickness at the fracture site was greater with vs without calcium modification (0.58 mm [0.50-0.66] vs 0.45 mm [0.38-0.52], P = 0.003). Final optimal stent expansion, defined as minimum stent area ≥6.1 mm2 or stent expansion ≥90% (medians of this cohort) at the maximum calcium angle site, was observed in 41 lesions. Larger post-OA lumen area (odds ratio 2.64; 95% CI 1.21-5.76; P = 0.02) and the presence of calcium fracture (odds ratio 6.77; 95% CI 1.25-36.6; P = 0.03) were independent predictors for optimal stent expansion. CONCLUSIONS: Calcium modification by OA facilitates poststent calcium fracture even in thick calcium. Greater calcium modification correlated with greater calcium fracture, in turn resulting in better stent expansion.

A prospective, single-center, randomized study to assess whether automated coregistration of optical coherence tomography with angiography can reduce geographic miss.

OBJECTIVE: We sought to evaluate whether automated coregistration of optical coherence tomography (OCT) with angiography reduces geographic miss (GM) during coronary stenting. BACKGROUND: Previous intravascular ultrasound or OCT studies have showed that residual disease at the stent edge or stent edge dissection was associated with stent thrombosis or edge restenosis. This has been termed GM. METHODS: Two hundred de novo coronary lesions were randomized in a 1:1 ratio to OCT-guided percutaneous coronary intervention (PCI) with versus without automated coregistration of OCT with angiography. GM, the primary endpoint, was defined as angiographic ≥type B dissection or diameter stenosis >50% or OCT minimum lumen area <4.0 mm2 with significant residual disease or dissection (dissection flap >60°) within 5 mm from the stent edge. RESULTS: The prevalence of GM was not different comparing OCT-guided PCI with versus without automated coregistration (27.6% vs 34.0%, P = 0.33). However, there was a trend toward a reduced prevalence of significant distal stent edge dissection in lesions with automated coregistration (11.1% vs 20.8%, P = 0.07). The discrepancy in the distance between planned versus actual implanted stent location with automated coregistration was significantly shorter than without coregistration (1.9 ± 1.6 mm vs 2.6 ± 2.7 mm, P = 0.03), especially the prevalence of ≥5 mm discrepancy that was less frequent with automated coregistration. CONCLUSIONS: Automated coregistration of OCT with angiography did not reduce the primary endpoint of GM after stent implantation.

A lognormal distribution of the lengths of terminal twigs on self-similar branches of elm trees.

Lognormal distributions and self-similarity are characteristics associated with a wide range of biological systems. The sequential breakage model has established a link between lognormal distributions and self-similarity and has been used to explain species abundance distributions. To date, however, there has been no similar evidence in studies of multicellular organismal forms. We tested the hypotheses that the distribution of the lengths of terminal stems of Japanese elm trees (Ulmus davidiana), the end products of a self-similar branching process, approaches a lognormal distribution. We measured the length of the stem segments of three elm branches and obtained the following results: (i) each occurrence of branching caused variations or errors in the lengths of the child stems relative to their parent stems; (ii) the branches showed statistical self-similarity; the observed error distributions were similar at all scales within each branch and (iii) the multiplicative effect of these errors generated variations of the lengths of terminal twigs that were well approximated by a lognormal distribution, although some statistically significant deviations from strict lognormality were observed for one branch. Our results provide the first empirical evidence that statistical self-similarity of an organismal form generates a lognormal distribution of organ sizes.

Angioscopic and optical coherence tomographic evaluation of neointimal coverage: 9 months after expandable polyterafluoroethylene covered stent implantation.

An expandable polytetrafluoroethylene (ePTFE) covered stent is generally employed to seal coronary artery perforation. The frequency of ePTFE covered stent use is relatively low; thus, only a handful of studies have reported neointimal coverage and endothelialization inside the deployed ePTFE and clinical time course after ePTFE implantation. This case report presents a 78-year-old man treated with an ePTFE covered stent when he suffered from coronary artery perforation after the implantation of two everolimus eluting stents in the left anterior descending artery. Follow-up coronary angiography 9 months after ePTFE covered stent implantation depicted favorable stent patency. Optical coherence tomography showed thin and uneven stent strut coverage at the culprit. Angioscopy also depicted partial white-coated coverage and stent strut exposure. The outcome of this case suggested that long-term dual antiplatelet therapy should be prescribed for preventing thrombosis after ePTFE covered stent implantation.

Optimization of the phenylurea moiety in a phosphoinositide 3-kinase (PI3K) inhibitor to improve water solubility and the PK profile by introducing a solubilizing group and ortho substituents.

Phosphoinositide 3-kinase (PI3K) is a promising anti-cancer target, because various mutations and amplifications are observed in human tumors isolated from cancer patients. Our dihydropyrrolopyrimidine derivative with a phenylurea moiety showed strong PI3K enzyme inhibitory activity, but its pharmacokinetic property was poor because of lack of solubility. Herein, we report how we improved the solubility of our PI3K inhibitors by introducing a solubilizing group and ortho substituents to break molecular planarity.

Geometrical Structures of Partially Oxidized Rhodium Cluster Cations, Rh6Om+ (m = 4, 5, 6), Revealed by Infrared Multiple Photon Dissociation Spectroscopy.

Infrared multiple photon dissociation (IRMPD) spectra of Rh6Om+ (m = 4-10) are obtained in the 300-1000 cm-1 spectral range using the free electron laser for infrared experiments (FELIX) via dissociation of Rh6Om+ or Rh6Om+-Ar complexes. The spectra are compared with the calculated spectra of several stable geometries obtained by density functional theory (DFT) structural optimization. The spectrum for Rh6O4+ shows prominent bands at 620 and 690 cm-1 and is assigned to a capped-square pyramidal Rh atom geometry with three bridging O atoms and one O atom in a hollow site. Rh6O5+ displays bands at 460, 630, 690, and 860 cm-1 and has a prismatic Rh geometry with three bridging O atoms and two O atoms in a hollow site. Rh6O6+ shows three intense bands around 600-750 cm-1 and multiple weak bands in the range of 350-550 cm-1. This species has a prismatic Rh geometry with four bridging O atoms and two O atoms in a hollow site. Considering that Rh6Om+ (m ≤ 3) adopts tetragonal bipyramidal Rh6 structures, the change at m = 4 to capped bipyramidal and at m = 5 to prismatic geometries results in a reduction of the number of triangular hollow sites. Since NO preferentially binds on a triangular hollow site through the N atom, the geometry change lowers the possibility of NO dissociative adsorption.

Modification of a dihydropyrrolopyrimidine phosphoinositide 3-kinase (PI3K) inhibitor to improve oral bioavailability.

Phosphoinositide 3-kinase (PI3K) is activated in various human cancer cells and well known as a cancer therapy target. We previously reported a dihydropyrrolopyrimidine derivative as a highly potent PI3K inhibitor that has strong tumor growth inhibition in a xenograft model. In this report, we describe further optimization to improve its bioavailability.

Thermal Desorption Spectroscopy Study of the Adsorption and Reduction of NO by Cobalt Cluster Ions under Thermal Equilibrium Conditions at 300 K.

Adsorption of NO molecules on gas phase cobalt cluster ions, Con(+) (n = 4-9), was investigated in thermal equilibrium with He gas at 300 K. The Con(+) clusters, contrary to the isolated clusters in a vacuum, adsorbed NO without undergoing significant dissociation. Thermal desorption spectroscopy of Con(+)(NO)m indicated that Con(+) clusters with n = 4-6 and n = 7-9 can have four and six adatoms chemisorbed, respectively. Reduction of NO occurred, releasing N2 molecules, to form Con(+)Ok(NO)m-k (k = 2, 4, ...). The reaction mechanism involved the exchange of chemisorbed N atoms with the O atom in NO bound to the clusters. The reactivity of Con(+) (n = 4-9) exhibited periodic n dependence, and Co6(+) and Co9(+) was similar to the case of the isolated Co16(+) clusters holding up to eight adatoms reported by Anderson et al. ( J. Chem. Phys . 2009 , 130 , 10992 - 11000 ).

Stable Stoichiometry of Gas-Phase Manganese Oxide Cluster Ions Revealed by Temperature-Programmed Desorption.

Temperature-programmed desorption (TPD) experiments were performed on gas-phase manganese oxide cluster ions, namely, Mn(n)O(m)(+) (n = 3-20) and Mn(n)O(m)(-) (n = 3-18). These cluster ions were prepared by laser ablation of a manganese rod in the presence of oxygen gas, and their composition was investigated using mass spectrometry. The composition of Mn(n)O(m)(±) distribution lies above the m = (4/3)n line. When the cluster ions were heated to 1000 K, Mn(n)O(m)(+) (m = (4/3)n + δ, with δ = -1, 0) and Mn(n)O(m)(-) (m = (4/3)n + δ, with δ = 0, 1) was found to be the predominant species, formed by thermal dissociation. These experimental findings indicate that the nascent manganese oxide clusters comprise robust Mn(n)O(m)(±) (m/n ≈ 4/3) and weakly bound excess oxygen atoms. On the basis of the TPD experiments, the oxygen-molecule release was identified as the main dissociation channel. The temperature dependence of O2 desorption was found to be similar among the clusters with the same oxygen excess or deficiency regardless of the number of Mn atoms. The threshold energy of O2 desorption was estimated for Mn4O(m)(+) (m = 6-11) and compared with bond dissociation energies calculated by density functional theory.

Rapid progression of a coronary artery aneurysm caused by IgG4-related disease.

BACKGROUND: IgG4-related disease (IgG4-RD) is a recently recognized fibro-inflammatory disorder that can affect almost any organ. IgG4-RD has also been reported in coronary arteries as periarteritis. IgG4-related coronary periarteritis may cause coronary artery aneurysms, and IgG4-related coronary artery aneurysms (IGCAs) are life-threatening. We describe a case of a patient with IGCA that highlights the usefulness and limitations of various IGCA evaluation modalities and provides insight into disease pathophysiology. CASE SUMMARY: A 60-year-old man with IgG4-RD diagnosed 2 years before and with IGCA at the proximal right coronary artery (RCA) on coronary angiography (CAG) 9 months prior to admission to the hospital presented with acute coronary syndrome. Emergent CAG revealed the rapid progression of IGCA at the RCA, an obstruction of the diagonal branch, and stenosis of the left anterior descending artery (LAD) and the high lateral branch (HL). The patient underwent percutaneous coronary intervention for the diagonal branch. The RCA aneurysm was resected and bypassed with a saphenous vein graft (SVG); coronary bypass grafting (left internal mammary artery to LAD and SVG to HL) was performed. Pathological findings showed inflammatory cell infiltration and disruption of the elastic plate. CONCLUSION: IGCAs require careful follow-up with computed tomography scans for early detection of aneurysmal enlargement.

The morphology and nutrient content drive the leaf carbon capture and economic trait variations in subtropical bamboo forest.

Carbon absorption capability and morphological traits are crucial for plant leaf function performance. Here, we investigated the five bamboos at different elevations in Wuyi Mountain to clarify how the leaf trait responds to the elevational gradient and drives the photosynthetic capacity variations. The Standardized Major Axis Regression (SMA) analyses and the Structural Equation Model (SEM) are applied to identify how the bamboo leaf trait, including the ratio of leaf width to length (W/L), leaf mass per area (LMA), photosynthesis rates (Pn), leaf nitrogen, and phosphorus concentration (Leaf N and Leaf P) response to elevation environment, and the driving mechanism of Pn changes. Across the five bamboo species, our results revealed that leaf P scaled isometrically with respect to W/L, leaf N scaled allometrically as the 0.80-power of leaf P, and leaf N and leaf P scaled allometrically to Pn, with the exponents of 0.58 and 0.73, respectively. Besides, the SEM result showed altitude, morphological trait (W/L and LMA), and chemical trait (leaf N and leaf P) could together explain the 44% variations of Pn, with a standard total effect value of 70.0%, 38.5%, 23.6% to leaf P, leaf N, and W/L, respectively. The five bamboo species along the different elevational share an isometric scaling relationship between their leaf P and W/L, providing partial support for the general rule and operating between morphological and chemical traits. More importantly, the leaf W/L and leaf P as the main trait that affects leaf area and P utilization in growth and thus drives bamboo leaf photosynthetic capacity variations in different elevations.

Comparative physiology of canopy tree leaves in evergreen and deciduous forests in lowland Thailand.

The typical seasonally dry forests in Southeast Asia are the mixed deciduous forest (MDF), dry dipterocarp (deciduous) forest (DDF), and dry evergreen forest (DEF). We obtained 21 physiological traits in the top/sunlit leaves of 107, 65 and 51 tree species in MDF, DEF and DDF, respectively. Approximately 70%, 95% and 95% of canopy tree species which consist of MDF, DEF and DDF are sampled, respectively. Light-saturated photosynthetic rates (Asat) exhibit a positive correlation with foliar nitrogen (N) and phosphorus (P) on leaf mass and area bases across tree species. Decreased leaf mass-based P reduces the positive slope of the mass-based N and Asat relationship across species and habitats. The differences in nutrient and water use and leaf habits are well matched to the variation in soil properties among the forest types, highlighting the reliability of this comprehensive database for revealing the mechanism of niche segregation based on edaphic factors.

[A case of sarcomatoid renal cell carcinoma associated with giant hydronephrosis].

A 55-year-old man with a huge cystic lesion in the left kidney was referred to our department. Preoperative computed tomographic scan with enhancement by contrast agents showed that the cyst wall had solid components. Left radical nephrectomy was performed. The resected kidney with giant hydronephrosis weighed 3,950 g and had a ureteral stone with a long diameter of 27 mm. The tumor had infiltrated the renal pelvis, and it was unclear whether the tumor had originated from the kidney or pelvis. Pathological findings showed that the tumor was sarcomatoid renal cell carcinoma. He was started on IFNa and IL-2 therapy. However, brain metastasis soon appeared followed by general worsening of his condition, and he died a month after the surgery.

Diurnal Change of the Photosynthetic Light-Response Curve of Buckbean (Menyanthes trifoliata), an Emergent Aquatic Plant.

Understanding plant physiological responses to high temperature is an important concern pertaining to climate change. However, compared with terrestrial plants, information about aquatic plants remains limited. Since the degree of midday depression of photosynthesis under high temperature depends on soil water conditions, it is expected that emergent aquatic plants, for which soil water conditions are always saturated, will show different patterns compared with terrestrial plants. We investigated the diurnal course of the photosynthetic light-response curve and incident light intensity for a freshwater emergent plant, buckbean (Menyanthes trifoliata L.; Menyanthaceae) in a cool temperate region. The effect of midday depression was observed only on a very hot day, but not on a moderately hot day, in summer. The diurnal course of photosynthetic light-response curves on this hot day showed that latent morning reduction of photosynthetic capacity started at dawn, preceding the apparent depression around the midday, in agreement with results reported in terrestrial plants. We concluded that (1) midday depression of emergent plants occurs when the stress intensity exceeds the species' tolerance, and (2) measurements of not only photosynthetic rate under field conditions but also diurnal course of photosynthetic light-response curve are necessary to quantify the effect of midday depression.