Silver-gold nanotubes containing hot spots on their surface: facile synthesis and surface-enhanced Raman scattering investigations

We report the synthesis of silver-gold nanotubes containing hot spots along their surface. The Ag-Au nanotubes exhibited exceptional SERS properties compared to silver nanowires, enabling the detection of crystal violet in the 10(-10) M regime, as well as 9-nitroanthracene and benzo[a] pyrene at 3.3 x 10(-7) M.

Gibberellic acid in vegetative and reproductive development of Phalaenopsis orchid hybrid genus

The flower industry represents about one billion dollars in Brazil and the development of techniques aimed at flowering control is required. This study evaluated the influence of gibberellic acid (GA3) on the vegetative and reproductive development of young plants of Phalaenopsis FSNT 'Dai-Itigo' hybrid pink color. The application of GA3 was made by foliar sprays at concentrations of 0, 125, 250, 500 and 1,000 mg L -1. The length of leaves increased significantly when using GA3 at low concentrations, but leaf width decreased. The application of GA3 at 125 mg L -1 showed the best results for the promotion of flowering and flower quality of this orchid hybrid. In this treatment, about 50% of plants treated with GA3 flowered about 6-12 months before the plants that were non-treated with this plant growth regulator. The quality of flowering and flowers was best with 125 mg L -1 GA3.

Novel positron emission tomography/computed tomography of diffuse parenchymal lung disease combining a labeled somatostatin receptor analogue and 2-deoxy-2[¹⁸F]fluoro-D-glucose

We prospectively investigated the potential of positron emission tomography (PET) using the somatostatin receptor (SSTR) analogue ⁶⁸Ga-DOTATATE and 2-deoxy-2[¹⁸F]fluoro-D-glucose (¹⁸F-FDG) in diffuse parenchymal lung disease (DPLD). Twenty-six patients (mean age 68.9 ± 11.0 years) with DPLD were recruited for ⁶⁸Ga-DOTATATE and ¹⁸F-FDG combined PET/high-resolution computed tomography (HRCT) studies. Ten patients had idiopathic pulmonary fibrosis (IPF), 12 patients had nonspecific interstitial pneumonia (NSIP), and 4 patients had other forms of DPLD. Using PET, the pulmonary tracer uptake (maximum standardized uptake value [SUV(max)]) was calculated. The distribution of PET tracer was compared to the distribution of lung parenchymal changes on HRCT. All patients demonstrated increased pulmonary PET signal with ⁶⁸Ga-DOTATATE and ¹⁸F-FDG. The distribution of parenchymal uptake was similar, with both tracers corresponding to the distribution of HRCT changes. The mean SUV(max) was 2.2 ± 0.7 for ⁶⁸Ga-DOTATATE and 2.8 ± 1.0 (t-test, p  =  .018) for ¹⁸F-FDG. The mean ⁶⁸Ga-DOTATATE SUV(max) in IPF patients was 2.5 ± 0.9, whereas it was 2.0 ± 0.7 (p  =  .235) in NSIP patients. The correlation between ⁶⁸Ga-DOTATATE SUV(max) and gas transfer (transfer factor of the lung for carbon monoxide [TLCO]) was r  =  -.34 (p  =  .127) and r  =  -.49 (p  =  .028) between ¹⁸F-FDG SUV(max) and TLCO. We provide noninvasive in vivo evidence in humans showing that SSTRs may be detected in the lungs of patients with DPLD in a similar distribution to sites of increased uptake of ¹⁸F-FDG on PET.

Disruption of SIRPα signaling in macrophages eliminates human acute myeloid leukemia stem cells in xenografts

Although tumor surveillance by T and B lymphocytes is well studied, the role of innate immune cells, in particular macrophages, is less clear. Moreover, the existence of subclonal genetic and functional diversity in some human cancers such as leukemia underscores the importance of defining tumor surveillance mechanisms that effectively target the disease-sustaining cancer stem cells in addition to bulk cells. In this study, we report that leukemia stem cell function in xenotransplant models of acute myeloid leukemia (AML) depends on SIRPα-mediated inhibition of macrophages through engagement with its ligand CD47. We generated mice expressing SIRPα variants with differential ability to bind human CD47 and demonstrated that macrophage-mediated phagocytosis and clearance of AML stem cells depend on absent SIRPα signaling. We obtained independent confirmation of the genetic restriction observed in our mouse models by using SIRPα-Fc fusion protein to disrupt SIRPα-CD47 engagement. Treatment with SIRPα-Fc enhanced phagocytosis of AML cells by both mouse and human macrophages and impaired leukemic engraftment in mice. Importantly, SIRPα-Fc treatment did not significantly enhance phagocytosis of normal hematopoietic targets. These findings support the development of therapeutics that antagonize SIRPα signaling to enhance macrophage-mediated elimination of AML.

Wild-type and splice-variant secretin receptors in lung cancer: overexpression in carcinoid tumors and peritumoral lung tissue

Gastrointestinal peptide hormone receptors, like somatostatin receptors, are often overexpressed in human cancer, allowing receptor-targeted tumor imaging and therapy. A novel candidate for these applications is the secretin receptor recently identified in pancreatic and cholangiocellular carcinomas. In the present study, secretin receptors were assessed in a non-gastrointestinal tissue, the human lung. Non-small-cell lung cancers (n=26), small-cell lung cancers (n=10), bronchopulmonary carcinoid tumors (n=29), and non-neoplastic lung (n=46) were investigated for secretin receptor protein expression with in vitro receptor autoradiography, using (125)I-[Tyr(10)] rat secretin and for secretin receptor transcripts with RT-PCR. Secretin receptor protein expression was found in 62% of bronchopulmonary carcinoids in moderate to high density, in 12% of non-small cell lung cancers in low density, but not in small cell lung cancers. In tumors found to be secretin receptor positive by autoradiography, RT-PCR revealed transcripts for the wild-type secretin receptor and for novel secretin receptor splice variants. In the non-neoplastic lung, secretin receptor protein expression was observed in low density along the alveolar septa in direct tumor vicinity in cases of acute inflammation, but not in histologically normal lung. In the autoradiographically positive peritumoral lung, RT-PCR showed transcripts for the wild-type secretin receptor and for a secretin receptor spliceoform different from those occurring in lung and gut tumors. In conclusion, secretin receptors are new markers for bronchopulmonary carcinoid tumors, and represent the molecular basis for an in vivo targeting of carcinoid tumors for diagnosis and therapy. Furthermore, secretin receptors may play a role in peritumoral lung pathophysiology. Secretin receptor mis-splicing specifically occurs in tumor and non-tumor lung pathology.

closo-borane conjugated regulatory peptides retain high biological affinity: synthesis of closo-borane conjugated Tyr(3)-octreotate derivatives for BNCT

Despite the improvements in cancer therapy during the past years, high-grade gliomas and many other types of cancer are still extremely resistant to current forms of therapy. Boron neutron capture therapy (BNCT) provides a promising way to destroy cancer cells without damaging healthy tissue. However, BNCT in practice is still limited due to the lack of boron-containing compounds that selectively deliver boron to cancer cells. Since many neuroendocrine tumors show an overexpression of the somatostatin receptor, it was our aim to synthesize compounds that contain a large number of boron atoms and still show high affinity toward this transmembrane receptor. The synthetic peptide Tyr (3)-octreotate (TATE) was chosen as a high-affinity and internalizing tumor targeting vector (TTV). Novel boron cluster compounds, containing 10 or 20 boron atoms, were coupled to the N-terminus of TATE. The obtained affinity data demonstrate that the use of a spacer between TATE and the closo-borane moiety is the option to avoid a loss of biological affinity of closo-borane conjugated TATE. For the first time, it was shown that closo-borane conjugated regulatory peptides retain high biological affinity and selectivity toward their transmembrane tumor receptors. The results obtained and the improvement of spacer and boron building block chemistry may stimulate new directions for BNCT.

National Elm Trial

Although many Dutch elm disease-resistant elm cultivars are available in the nursery trade, much of the public is hesitant to purchase and plant any elm tree. In order to promote interest in planting these trees, scientific data on growth, form, and pest resistance for existing Dutch elm disease resistant elm cultivars are essential.

Controlling Bacterial Wilt in Muskmelon with Perimeter Trap Cropping

Perimeter trap cropping (PTC) involves planting one or more rows of a cucurbit crop that is highly attractive to cucumber beetles around the border of a main cucurbit cash crop that is less attractive to the beetles. Cucumber beetles attempting to migrate into the field are concentrated in the relatively more attractive border crop, where they can be controlled by insecticides. In New England, perimeter trap cropping using Blue Hubbard squash as the border crop around pumpkin, cucumber, or butternut squash controlled cucumber beetle/bacterial wilt with as few as one border spray of insecticide. This strategy reduced insecticide use on the main crop by up to 94 percent, nearly eliminating sprays on the main cash crop. In on-farm trials, 8 of 10 Massachusetts growers found that using perimeter trap cropping saved them money. The same tactic also effectively managed cucumber beetles on muskmelon and squash in Oklahoma.

On-farm Cooperator Trials 2011: Effect of Extended-duration Row Covers on Muskmelon and Winter Squash on Bacterial Wilt and Yield

Susceptible cucurbit crops are difficult to grow in Iowa because of bacterial wilt, caused by Erwinia tracheiphila. Striped and spotted cucumber beetles transmit bacterial wilt. Other insect pests such as squash vine borer and squash bugs may also have an economic impact on yield, particularly in squash.

Squash Bug, Squash Vine Borer, and Striped Cucumber Beetle on Butternut Squash and Muskmelon

Alternative agricultural schemes are gaining attention as the demand for organic and sustainable products continues to grow. Pest insects pose a sizeable challenge to agricultural production because their activities reduce crop fitness and productivity. Effective management of pest-insects is, therefore, crucial for successful management, and increasingly entails a multi-dimensional approach.

Weather Inputs to a Warning System for Sooty Blotch and Flyspeck of Apple

Sooty blotch and flyspeck (SBFS) is a mid- to late-season disease of apple. SBFS fungi show up as dark smudges and clusters of black dots on the fruit surface. Since blemished fruit are downgraded, crop losses can exceed 90 percent of the fresh market value.

Testing a Warning System for Anthracnose Fruit Rot on Day-neutral Strawberry

Anthracnose fruit rot (AFR) of strawberry is caused by three Colletotrichum spp. In the Midwest, however, only Colletotrichum acutatum is found. This fungus can attach itself to apparently healthy plants and spread throughout without causing symptoms on the foliage. When fruit begin to ripen and weather conditions are rainy and warm, AFR can suddenly cause great damage to the fruit. To protect against AFR where it has appeared in the past, growers need to spray every 7 to 10 days beginning at the start of bloom until harvest.

Organic Practices for the Production of Butternut Squash

Growers of organic squash need effective ways to manage insect and disease problems. The squash bug (Anasa tristis) sucks sap, causing leaves to wilt and turn black. The squash vine borer (Melittia cucurbitae) can devastate winter squash plantings. Burrowing by larvae into the base of the stem causes yellowing and wilting. Organic insecticides are expensive, have limited efficacy, require many applications, and some kill beneficial as well as target insects.

Organic Practices for the Production of Muskmelon

Cucurbit crops, especially muskmelon and cucumber, attract cucumber beetles, which vector bacterial wilt: Erwinia tracheiphila, causing significant crop losses. High beetle densities are associated with high bacterial wilt incidence, which usually occurs during the first stages of plant establishment. Growers of organic muskmelon need effective ways to manage the cucumber beetle/bacterial wilt complex.

Purification of primitive human hematopoietic cells capable of repopulating immune-deficient mice

The purification of primitive human hematopoietic stem cells has been impaired by the absence of repopulation assays. By using a stringent two-step strategy involving depletion of lineage-positive cells followed by fluorescence-activated cell sorting, we have purified a cell population that is highly enriched for cells capable of multilineage repopulation in nonobese diabetic/severe combined immunodeficient (NOD/SCID) recipients. These SCID-repopulating cells (SRCs) were exclusively found in a cell fraction that expressed high levels of CD34 and no CD38. Through limiting dilution analysis using Poisson statistics, we calculated a frequency of 1 SRC in 617 CD34+ CD38− cells. The highly purified SRC were capable of extensive proliferation in NOD/SCID mice. Mice transplanted with 1 SRC (at limiting cell doses) were able to produce approximately 400,000 progeny 6 weeks after the transplant. Detailed flow cytometric analysis of the marrow of highly engrafted mice demonstrated both lymphoid and myeloid differentiation, as well as the retention of a significant fraction of CD34+ CD38− cells. These highly purified fractions should be useful for identification of the cellular and molecular mechanisms that regulate primitive human hematopoietic cells. Moreover, the ability to detect and purify primitive cells provides a means to develop conditions for maintaining and/or expanding these cells during in vitro culture.