Testing a generalized leaf mass estimation method for diverse tree species and climates of the continental United States.

Estimating tree leaf biomass can be challenging in applications where predictions for multiple tree species is required. This is especially evident where there is limited or no data available for some of the species of interest. Here we use an extensive national database of observations (61 species, 3628 trees) and formulate models of varying complexity, ranging from a simple model with diameter at breast height (DBH) as the only predictor to more complex models with up to 8 predictors (DBH, leaf longevity, live crown ratio, wood specific gravity, shade tolerance, mean annual temperature, and mean annual precipitation), to estimate tree leaf biomass for any species across the continental United States.

Alpine treeline ecotones are potential refugia for a montane pine species threatened by bark beetle outbreaks.

Warming-induced mountain pine beetle (Dendroctonus ponderosae; MPB) outbreaks have caused extensive mortality of whitebark pine (Pinus albicaulis; WBP) throughout the species' range. In the highest mountains where WBP occur, they cross alpine treeline ecotones (ATEs) where growth forms transition from trees to shrub-like krummholz, some of which survived recent MPB outbreaks. This observation motivated the hypothesis that ATEs are refugia for WBP because krummholz growth forms escape MPB attack and have the potential to produce viable seed.

Rising above helium: A hydrogen carrier gas chromatography flame ionization detection (GC-FID) method for the simultaneous quantification of toxic alcohols and ethylene glycol in human plasma specimens.

Unlabelled: Here we validate a GC, Flame Ionization Detection (GC-FID), liquid injection method using hydrogen as a carrier gas combining analysis of toxic volatile alcohols (VA): methanol, ethanol, isopropanol, acetone, as well as glycols, ethylene glycol (EG) and propylene glycol (PG), in a single method.

Methodology: 200 μL of calibrator, QC, or patient specimen were deproteinized with 400 μL of acetonitrile containing internal standards (10 mmol/L N-propyl alcohol for VA and 2.5 mmol/L 1,2-butanediol for glycols).

Decreasing fire season precipitation increased recent western US forest wildfire activity.

Western United States wildfire increases have been generally attributed to warming temperatures, either through effects on winter snowpack or summer evaporation. However, near-surface air temperature and evaporative demand are strongly influenced by moisture availability and these interactions and their role in regulating fire activity have never been fully explored. Here we show that previously unnoted declines in summer precipitation from 1979 to 2016 across 31-45% of the forested areas in the western United States are strongly associated with burned area variations.

Critical analyses when modeling tree biomass to ensure additivity of its components.

It is presented the theme additivity of biomass of tree components. To evaluate and discuss this context, experimental information collected in forests of Acacia mearnsii De Wild. was used.

Future global productivity will be affected by plant trait response to climate.

Plant traits are both responsive to local climate and strong predictors of primary productivity. We hypothesized that future climate change might promote a shift in global plant traits resulting in changes in Gross Primary Productivity (GPP). We characterized the relationship between key plant traits, namely Specific Leaf Area (SLA), height, and seed mass, and local climate and primary productivity.

Remote Sensing Derived Fire Frequency, Soil Moisture and Ecosystem Productivity Explain Regional Movements in Emu over Australia.

Species distribution modeling has been widely used in studying habitat relationships and for conservation purposes. However, neglecting ecological knowledge about species, e.g.

One-step extraction and quantitation of toxic alcohols and ethylene glycol in plasma by capillary gas chromatography (GC) with flame ionization detection (FID).

Objectives: Clinical analysis of volatile alcohols (i.e. methanol, ethanol, isopropanol, and metabolite acetone) and ethylene glycol (EG) generally employs separate gas chromatography (GC) methods for analysis.

SIB-DOTA: a trifunctional prosthetic group potentially amenable for multi-modal labeling that enhances tumor uptake of internalizing monoclonal antibodies.

A major drawback of internalizing monoclonal antibodies (mAbs) radioiodinated with direct electrophilic approaches is that tumor retention of radioactivity is compromised by the rapid washout of iodo-tyrosine, the primary labeled catabolite for mAbs labeled via this strategy. In our continuing efforts to develop more versatile residualizing labels that could overcome this problem, we have designed SIB-DOTA, a prosthetic labeling template that combines the features of the prototypical, dehalogenation-resistant N-succinimidyl 3-iodobenzoate (SIB) with DOTA, a useful macrocyclic chelator for labeling with radiometals. Herein we describe the synthesis of the unlabeled standard of this prosthetic moiety, its protected tin precursor, and radioiodinated SIB-DOTA.

Assessing the performance of sampling designs for measuring the abundance of understory plants.

Accurate estimation of responses of understory plants to disturbance is essential for understanding the efficacy of management activities. However, the ability to assess changes in the abundance of plants may be hampered by inappropriate sampling methodologies. Conventional methods for sampling understory plants may be precise for common species but may fail to adequately characterize abundance of less common species.

[Lu]-DOTA-Tyr-octreotate: A Potential Targeted Radiotherapeutic for the Treatment of Medulloblastoma.

Medulloblastoma, the most common pediatric brain tumor, is difficult to treat because conventional therapeutic approaches result in significant toxicity to normal central nervous system tissues, compromising quality of life. Given the fact that medulloblastomas express the somatostatin subtype 2 receptor, [(177)Lu-DOTA(0),Tyr(3)]octreotate ([(177)Lu]DOTA-TATE) could be a potentially useful targeted radiotherapeutic for the treatment of this malignancy. The current study was undertaken to evaluate this possibility in preclinical models of D341 MED human medulloblastoma by comparing the properties of [(177)Lu]DOTA-TATE to those of glucose-[(125)I-Tyr(3)]-octreotate ([(125)I]Gluc-TOCA), a radiopeptide previously shown to target this cell line.

Radioiodinated O(6)-Benzylguanine derivatives containing an azido function.

Introduction: Drug resistance to alkylator chemotherapy has been primarily attributed to the DNA repair protein alkylguanine-DNA alkyltransferase (AGT); thus, personalizing chemotherapy could be facilitated if tumor AGT content could be quantified prior to administering chemotherapy. We have been investigating the use of radiolabeled O(6)-benzylguanine (BG) analogues to label and quantify AGT in vivo. BG derivatives containing an azido function were sought to potentially enhance the targeting of these analogues to AGT, which is primarily present in the cell nucleus, either by conjugating them to nuclear localization sequence (NLS) peptides or by pretargeting via bio-orthogonal approaches.

Targeting aldehyde dehydrogenase: a potential approach for cell labeling.

Introduction: To advance the science and clinical application of stem cell therapy, the availability of a highly sensitive, quantitative and translational method for tracking stem cells would be invaluable. Because hematopoetic stem cells express high levels of the cytosolic enzyme aldehyde dehydrogenase-1A1 (ALDH1), we sought to develop an agent that is specific to ALDH1 and thus to cells expressing the enzyme. Such an agent might be also helpful in identifying tumors that are resistant to cyclophosphomide chemotherapy because ALDH1 is known to be responsible for this resistance.

A radioiodinated MIBG-octreotate conjugate exhibiting enhanced uptake and retention in SSTR2-expressing tumor cells.

Several neuroendocrine tumors are known to express both the somatostatin receptor subtype 2 (SSTR2) and the norepinephrine transporter (NET), and radiopharmaceuticals directed toward both these targets such as MIBG and octreotide derivatives are routinely used in the clinic. To investigate the possibility of targeting both NET and SSTR2 conjointly, a conjugate of radioiodinated MIBG and octreotate was synthesized. Attempts to synthesize the radioiodinated target compound (MIBG-octreotate; [ (131)I] 12a) from a tin precursor were futile; however, it could be accomplished from a bromo precursor by exchange radioiodination in 3-36% ( n = 10) radiochemical yields.

A kit method for the high level synthesis of [211At]MABG.

meta-[(211)At]Astatobenzylguanidine ([(211)At]MABG), an analogue of meta-iodobenzylguanidine (MIBG) labeled with the alpha-emitter (211)At, targets the norepinephrine transporter. Because MABG has been shown to have excellent characteristics in preclinical studies, it has been considered to be a promising targeted radiotherapeutic for the treatment of tumors such as micrometastatic neuroblastoma that overexpress the norepinephrine transporter. To facilitate clinical evaluation of this agent, a convenient method for the high level synthesis of [(211)At]MABG that is adaptable for kit formulation has been developed.

Synthesis and evaluation of glycosylated octreotate analogues labeled with radioiodine and 211At via a tin precursor.

Carbohydration of N-terminus and substitution of a threonine for the threoninol residue at the C-terminus of Tyr3-octreotide (TOC) has resulted in improved pharmacokinetics and tumor targeting of its radioiodinated derivatives. Yet, these peptides are very susceptible to in vivo deiodination due to the similarity of monoiodotyrosine (MIT) to thyroid hormone. The goal of this work was to develop octreotate analogues containing both a sugar moiety and a nontyrosine prosthetic group on which a radioiodine or 211At can be introduced.

No-carrier-added synthesis of a 4-methyl-substituted meta-iodobenzylguanidine analogue.

Radioiodinated meta-iodobenzylguanidine (MIBG) is used in the diagnosis and therapy of various neuroendocrine tumors. As a part of our efforts to develop an MIBG analogue with improved characteristics for these applications, a synthesis of 3-[131I]iodo-4-methylbenzylguanidine ([131I]MeIBG) was developed. Unlabeled MeIBG and the tin precursor, N, N'-(bis-tert-butyloxycarbonyl)-N-(4-methyl-3-trimethylstannylbenzyl) guanidine were synthesized in two steps from 3-iodo-4-methylbenzylalcohol.

Flow dynamics of the internal thoracic and radial artery T-graft.

Background: Complex use of arterial conduits has resurrected concerns about the adequacy of conduit flow. The T-graft is the extreme example of this trend. Our purpose was to identify the limitation of single source inflow and to compare flow capacity with completion coronary flow.

Evaluation of an internalizing monoclonal antibody labeled using N-succinimidyl 3-[131I]iodo-4-phosphonomethylbenzoate ([131I]SIPMB), a negatively charged substituent bearing acylation agent.

Monoclonal antibodies such as L8A4, reactive with the epidermal growth factor receptor variant III, internalize after receptor binding resulting in proteolytic degradation by lysosomes. Labeling internalizing mAbs requires the use of methodologies that result in the trapping of labeled catabolites in tumor cells after intracellular processing. Herein we have investigated the potential utility of N-succinimidyl-3-[131I]iodo-4-phosphonomethylbenzoate ([131I]SIPMB), an acylation agent that couples the corresponding negatively charged acid [131I]IPMBA to the protein, for this purpose.

Catabolism of 4-fluoro-3-iodobenzylguanidine and meta-iodobenzylguanidine by SK-N-SH neuroblastoma cells.

Background: A fluorine substituted derivative of meta-iodobenzylguanidine (MIBG), 4-fluoro-3-iodobenzylguanidine (FIBG), is retained in SK-N-SH human neuroblastoma cells in vitro to a higher degree than the MIBG.

Method: To investigate whether the higher retention of FIBG is due to differences in the catabolic degradation of the two tracers, in vitro paired-label studies were performed using SK-N-SH cells.

Results: No detectable amount of benzyl amines, benzoic acids or hippuran derivatives, potential catabolites of these tracers, were seen in either case.

Inhaled prostacyclin is safe, effective, and affordable in patients with pulmonary hypertension, right heart dysfunction, and refractory hypoxemia after cardiothoracic surgery.

Background: The purpose of this study was to describe our institutional experience in using inhaled prostacyclin as a selective pulmonary vasodilator in patients with pulmonary hypertension, refractory hypoxemia, and right heart dysfunction after cardiothoracic surgery.

Methods: Between February 2001 and March 2003, cardiothoracic surgical patients with pulmonary hypertension (mean pulmonary artery pressure >30 mm Hg or systolic pulmonary artery pressure >40 mm Hg), hypoxemia (PaO(2)/fraction of inspired oxygen <150 mm Hg), or right heart dysfunction (central venous pressure >16 mm Hg and cardiac index <2.2 L.

Meta-iodobenzylguanidine derivatives containing a second guanidine moiety.

Radioiodinated meta-iodobenzylguanidine (MIBG) is used in the diagnosis and therapy of various neuroendocrine tumors. To investigate whether an additional guanidine function in the structure of MIBG will yield analogues that may potentially enhance tumor-to-target ratios, two derivatives-one with a guanidine moiety and another with a guanidinomethyl group at the 4-position of MIBG-were prepared. In the absence of any uptake-1 inhibiting conditions, the uptake of 4-guanidinomethyl-3-[(131)I]iodobenzylguanidine ([(131)I]GMIBG) by SK-N-SH cells in vitro was 1.

O6-3-[131I]iodobenzylguanine: improved synthesis and further evaluation of a potential agent for imaging of alkylguanine-DNA alkyltransferase.

O(6)-Benzylguanine derivatives with suitable radionuclides attached to the benzyl ring are potentially useful in the noninvasive imaging of the DNA repair protein, alkylguanine-DNA alkyltransferase (AGT). Previously, O(6)-3-[(131)I]iodobenzylguanine ([(131)I]IBG) was prepared using a two-step approach; we now report its synthesis in a single step by the radioiododestannylation of O(6)-3-(trimethylstannyl)benzylguanine in 85-95% radiochemical yield. The in vitro specific uptake of [(131)I]IBG in DAOY human medulloblastoma cells, in TE-671 human rhabdomyosarcoma cells and a CHO cell line transfected to express AGT was linear (r(2) = 0.

N-succinimidyl 3-[211At]astato-4-guanidinomethylbenzoate: an acylation agent for labeling internalizing antibodies with alpha-particle emitting 211At.

The objective of this study was to develop a method for labeling internalizing monoclonal antibodies (mAbs) such as those reactive to the anti-epidermal growth factor receptor variant III (EGFRvIII) with the alpha-particle emitting radionuclide (211)At. Based on previous work utilizing the guanidine-containing acylation agent, N-succinimidyl 4-guanidinomethyl-3-[(131)I]iodobenzoate ([(131)I]SGMIB), we have now investigated the potential utility of its astato analogue for labeling the anti-EGFRvIII mAb L8A4. N-succinimidyl 3-[(211)At]astato-4-guanidinomethylbenzoate ([(211)At]SAGMB) in its Boc-protected form was prepared from a tin precursor in 61.