Feeding Behavior and Fruiting Form Damage by Bollworm (Lepidoptera: Noctuidae) in Bt Cotton.

Bt technologies have played a major role in the control of bollworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), in cotton. Variation in expression levels among varieties and plant parts, along with selection pressure on bollworm populations, has led to the development of resistance to some Bt proteins. Trials were conducted to evaluate how cotton varieties expressing different Bt proteins affect bollworm larval behavior and their damage in flowering cotton. Differences in larval recovery were observed among cotton varieties at 3 d with 3-gene Bt cotton having the lowest recovery and non-Bt cotton having the greatest recovery. Loss of bloom tags and abscission of small bolls at the site of infestation affected bollworm larval recovery among varieties. Day after infestation was the main factor that affected bollworm movement across all varieties. Number of total damaged fruiting forms by an individual bollworm larva was different among all varieties. Overall, flower bud (square) and fruit (boll) damage by an individual larva was lower on 3-gene cotton than 2-gene cotton and non-Bt cotton. An individual larva damaged fewer squares on 2-gene cotton than non-Bt cotton, but boll damage from bollworm was similar among 2-gene cotton and non-Bt cotton. The level of square and boll damage in 2-gene cotton has increased compared to previous research further supporting the occurrence of bollworm resistance to Cry proteins. The 3-gene cotton containing the Vip3A gene experienced low levels of damage and survival. These results will be important for improving management recommendations of bollworm in Bt cotton technologies.

Evaluation of Current Tarnished Plant Bug (Hemiptera: Miridae) Thresholds in Transgenic MON 88702 Cotton Expressing the Bt Cry51Aa2.834_16 Trait.

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is an important pest of cotton in many areas of the southern United States. An experiment was conducted at two locations in Mississippi during 2016 and 2017 to evaluate action thresholds for tarnished plant bug on a novel Bacillus thuringiensis cotton that expresses the Cry51Aa2.834_16 toxin. Treatments included the current action threshold, a 2× threshold, and treatments where insecticides were only applied during the early season (preflower) or only during late season (during flowering) based on the current action thresholds. These were compared to an untreated control and a weekly insecticide use regime that received weekly insecticide sprays. All treatments were imposed on both Bt Cry1Aa2.834_16 cotton and a nontraited cotton. The Bt Cry1Aa2.834_16 trait reduced the number of tarnished plant bugs and injury, and improved yields compared to nontraited cotton. For all spray treatments except the weekly insecticide use regime, yields were greater for the Bt Cry51Aa2.834_16 cotton than the nontraited cotton. In terms of thresholds, Bt Cry1Aa2.834_16 cotton sprayed based on current action thresholds resulted in similar yields to the weekly insecticide use regime of both cotton types. In contrast, the 2× threshold resulted in lower yields than the current threshold for both cotton types. Though thresholds intermediate to the currently recommended action threshold and the 2× threshold were not tested, these data suggest that currently recommended action thresholds appear appropriate for Bt Cry51Aa2.834_16 cotton. These results suggest that this trait will be an important component of current IPM programs in cotton where tarnished plant bug is an important pest.

Value of Neonicotinoid Insecticide Seed Treatments in Mid-South Cotton (Gossypium hirsutum [Malvales: Malvaceae]) Production Systems.

Neonicotinoid insecticides are currently one of two classes of chemicals available as a seed treatment for growers to manage early season insect pests of cotton, Gossypium hirsutum L. (Malvales: Malvaceae), and they are used on nearly 100% of cotton hectares in the midsouthern states. An analysis was performed on 100 seed-treatment trials from Arkansas, Louisiana, Mississippi, and Tennessee to determine the value of neonicotinoid seed treatments in cotton production systems. The analysis compared seed treated with neonicotinoid insecticides seed treatments plus a fungicide with seed only treated with fungicide. When analyzed by state, cotton yields were significantly greater when neonicotinoid seed treatments were used compared with fungicide-only treatments. Cotton treated with neonicotinoid seed treatments yielded 123, 142, 95, and 104 kg ha-1, higher than fungicide only treatments for Arkansas, Louisiana, Mississippi, and Tennessee, respectively. Across all states, neonicotinoid seed treatments provided an additional 115 kg lint ha-1 comparedwith fungicide only treated seed. Average net returns from cotton with a neonicotinoid seed treatment were $1,801 per ha-1 compared with $1,660 per ha-1 for cottonseed treated with fungicide only. Economic returns for cotton with neonicotinoid seed treatments were significantly greater than cottonseed treated with fungicide only in 8 out of 15 yr representing every state. These data show that neonicotinoid seed treatments provide significant yield and economic benefits in Mid-South cotton compared with fungicide only treated seed.

Value of Neonicotinoid Insecticide Seed Treatments in Mid-South Corn (Zea mays) Production Systems.

Neonicotinoid seed treatments are one of several effective control options used in corn, Zea mays L., production in the Mid-South for early season insect pests. An analysis was performed on 91 insecticide seed treatment trials from Arkansas, Louisiana, Mississippi, and Tennessee to determine the value of neonicotinoids in corn production systems. The analysis compared neonicotinoid insecticide treated seed plus a fungicide to seed only with the same fungicide. When analyzed by state, corn yields were significantly higher when neonicotinoid seed treatments were used compared to fungicide only treated seed in Louisiana and Mississippi. Corn seed treated with neonicotinoid seed treatments yielded 111, 1,093, 416, and 140 kg/ha, higher than fungicide only treatments for Arkansas, Louisiana, Mississippi, and Tennessee, respectively. Across all states, neonicotinoid seed treatments resulted in a 700 kg/ha advantage compared to fungicide only treated corn seed. Net returns for corn treated with neonicotinoid seed treatment were $1,446/ha compared with $1,390/ha for fungicide only treated corn seed across the Mid-South. Economic returns for neonicotinoid seed treated corn were significantly greater than fungicide-only-treated corn seed in 8 out of 14 yr. When analyzed by state, economic returns for neonicotinoid seed treatments were significantly greater than fungicide-only-treated seed in Louisiana. In some areas, dependent on year, neonicotinoid seed treatments provide significant yield and economic benefits in Mid-South corn.

Susceptibility of Flowering Cotton to Damage and Yield Loss from Tarnished Plant Bug (Hemiptera: Miridae).

The tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), is a major pest of cotton in the midsouthern United States, including the states of Arkansas, Mississippi, Louisiana, western Tennessee, and southeastern Missouri. Insecticides provide the primary form of control for this pest, and numerous applications are required annually to control the tarnished plant bug. Little information exists regarding when to terminate insecticide applications targeting tarnished plant bugs in cotton. Numerous sprays are made late in the season to protect a small percentage of the overall yield. Experiments were conducted at the Mississippi State University Delta Research and Extension Center to determine the impact of tarnished plant bug infestation timings on cotton yield. Two separate planting dates were utilized to determine the weeks of flowering that tarnished plant bugs can cause significant yield losses. There was a significant planting date by treatment interaction. Overall, yields were greater in the first planting date than the second planting date. In both planting dates, the first 4 wk of flowering were the most critical for tarnished plant bug control, and this is when the greatest yield losses occurred. Also, when no insecticide applications were made after the fourth week of flowering, no significant yield loss was observed. These data demonstrate the importance of scouting and adhering to treatment thresholds during the early flowering period. These data also suggest that thresholds may be able to be modified or eliminated after the fourth week of flowering, but more research is needed to confirm this.

Value of Neonicotinoid Insecticide Seed Treatments in Mid-South Soybean ( Glycine max ) Production Systems.

Early-season insect management is complex in the Mid-South region of the United States. A complex of multiple pest species generally occurs simultaneously at subthreshold levels in most fields. Neonicotinoids are the only insecticide seed treatment widely used in soybean, Glycine max L., production. An analysis was performed on 170 trials conducted in Arkansas, Louisiana, Mississippi, and Tennessee from 2005 to 2014 to determine the impact of neonicotinoid seed treatments in soybean. The analysis compared soybean seed treated with a neonicotinoid insecticide and a fungicide with soybean seed only treated with the same fungicide. When analyzed by state, soybean yields were significantly greater in all states when neonicotinoid seed treatments were used compared with fungicide-only treatments. Soybean treated with neonicotinoid treatments yielded 112.0 kg ha -1 , 203.0 kg ha -1 , 165.0 kg ha -1 , and 70.0 kg ha -1 , higher than fungicide-only treatments for Arkansas, Louisiana, Mississippi, and Tennessee, respectively. Across all states, neonicotinoid seed treatments yielded 132.0 kg ha -1 more than with fungicide-only treated seed. Net returns from neonicotinoid seed treatment usage were US$1,203 per ha -1 compared with US$1,172 per ha -1 for fungicide-only treated seed across the Mid-South. However, economic returns for neonicotinoid seed treatments were significantly greater than fungicide-only treated seed in 4 out of the 10 yr. When analyzed by state economic returns the neonicotinoid seed treatments were significantly greater than fungicide-only treated seed in Louisiana and Mississippi. These data show that in some areas and years, neonicotinoid seed treatments provide significant economic benefits in Mid-South soybean.

A biological comparison of tarnished plant bug (Hemiptera: Miridae) populations from Mississippi's major agricultural regions.

A laboratory experiment was performed to compare fitness parameters of the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations collected from the Hills and Delta regions of Mississippi. Each population was split into two cohorts to be reared on cotton or artificial diet to make comparisons of food source and region of collection. Each population was maintained separately and allowed to mate. Nymphal survivorship from the F1 generation of each population from each region and food source was compared. Parameters measured included development times to fourth instar, fifth instar and adult, total nymphal survivorship, fecundity, and fertility. Populations collected from the Delta region and reared on cotton developed significantly faster at all life stages than other populations. Tarnished plant bugs from the Hills reared on cotton developed significantly slower than other populations, except those from the Hills reared on artificial diet. Populations reared on diet had significantly higher survivorship than those reared on cotton. Tarnished plant bug populations from the Delta region laid significantly more eggs per female per day than those from the Hills region. Populations reared on cotton also laid significantly more eggs per female per day than those reared on diet. Populations collected in the Delta region laid significantly more viable eggs per female per day than those from the Hills region. Tarnished plant bugs reared on cotton produced significantly more nymphs per female per day than those reared on diet. These data indicate there are differences in several fitness parameters between tarnished plant bug populations from the Hills and Delta regions of Mississippi.

Impact of planting date and varietal maturity on tarnished plant bug (Hemiptera: Miridae) in cotton.

A field experiment was conducted in Stoneville, MS, during 2010 and 2011 to investigate the impact of varietal maturity, planting date, and insecticide application on tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), populations and damage in cotton. Four planting dates were selected to encompass the cotton-planting period in Mississippi. An early and late maturing variety were planted at each planting date, and each variety and planting date combination was either sprayed or unsprayed for tarnished plant bugs. Plots were sampled weekly from first square until physiological maturity. Plots were harvested at the end of the season. Early planting dates had lower densities of tarnished plant bug and required fewer insecticide applications than the later planting dates. Mid-April to early May planting dates sustained less yield loss from tarnished plant bug than mid-May to late-May planting dates. Tarnished plant bug had less impact on yield of the early maturing variety than on the late maturing variety. The sprayed plots yielded more than unsprayed plots. These data demonstrate that later plantings of cotton in the Mississippi Delta are likely to experience yield losses from tarnished plant bug and need to be sprayed more compared with early cotton plantings. As a result, growers should manage their crop for earliness through planting date and varietal selection.

SV40 Pseudovirion gene delivery of a toxin to treat human adenocarcinomas in mice.

SV40 vectors packaged in vitro (pseudovirions) are an efficient delivery system for plasmids up to 17.7 kb, with or without SV40 sequences. A truncated Pseudomonas exotoxin gene (PE38) was delivered into various human cells (HeLa, KB-3-1, human lymphoblastoids, and erythroleukemia cells), in vitro using pseudovirions. The number of viable cells was reduced significantly in the PE38-transduced cells. Human KB adenocarcinomas growing in mice were treated with intratumoral injection of PE38 packaged in vitro, and tumor size decreased significantly. Intraperitoneal treatments were as effective in reducing tumor size as intratumoral treatments. To check the viability of mock- or PE38-treated mice, every 4 days they were weighed, their blood was tested, and various tissues were screened for pathology. All parameters showed that the in vitro-packaged vectors, injected into tumors or intraperitoneally, caused no abnormalities in mice. The combined treatment of doxorubicin with in vitro-packaged PE38 reduced tumor size slightly more than each of the treatments separately. However, the combined treatment did not cause the weight loss seen with doxorubicin alone. These results indicate that SV40 in vitro packaging is an effective system for cancer gene delivery using two different routes of injection and in combination with chemotherapy.

The PEP respiratory monitor: a validation study.

The search for a reliable and accurate respiratory rate monitor for use in non-intubated patients has proved to be a long and fruitless one. A new device fulfilling the criteria for such a monitor has recently been described. The pyroelectric polymer (PEP) device is safe, non-invasive, and cheap. In this study the PEP device, transthoracic impedance, and standard observer counting were all compared with the existing gold standard of capnography in 12 healthy adult volunteers. Using a standard statistical technique it was shown that the PEP device performed as well as a capnograph and was more accurate than the other currently available methods of monitoring respiratory rate.

A natural product that lowers cholesterol as an antagonist ligand for FXR.

Extracts of the resin of the guggul tree (Commiphora mukul) lower LDL (low-density lipoprotein) cholesterol levels in humans. The plant sterol guggulsterone [4,17(20)-pregnadiene-3,16-dione] is the active agent in this extract. We show that guggulsterone is a highly efficacious antagonist of the farnesoid X receptor (FXR), a nuclear hormone receptor that is activated by bile acids. Guggulsterone treatment decreases hepatic cholesterol in wild-type mice fed a high-cholesterol diet but is not effective in FXR-null mice. Thus, we propose that inhibition of FXR activation is the basis for the cholesterol-lowering activity of guggulsterone. Other natural products with specific biologic effects may modulate the activity of FXR or other relatively promiscuous nuclear hormone receptors.

Placement of electrodes for defibrillation--a review of the evidence.

Defibrillation is the only reliable treatment for ventricular fibrillation. Its success depends on the passage of an adequate current through the chest rather than on the administration of a preset energy. The final determinant of both efficacy and cellular damage is myocardial current density. Therefore, the current should be evenly distributed with an average value that exceeds the defibrillation threshold throughout a critical mass of myocardium but does not cause further local dysfunction. The distribution of current is altered by the relative positions of the two electrodes. European guidelines for electrode (paddle) placement during defibrillation are based on empirical studies and traditional practice. However, there is increasing evidence to suggest that bi-axillary electrode placement may be superior to traditional antero-apical and antero-posterior positions.

Remobilization of patients who fail to achieve minimal progenitor thresholds at the first attempt is clinically worthwhile.

A significant proportion of previously treated patients fail to mobilize sufficient stem/progenitor cells to enable high-dose therapy and peripheral blood stem cell transplantation to be performed. In this study, the value of remobilizing such patients has been evaluated in 20 patients who all failed to achieve progenitor yields of 1 x 10(6)/kg CD34+ cells and 1 x 10(5)/kg granulocyte-monocyte colony-forming units (GM-CFCs) at the first attempt. Most patients remained relatively poor mobilizers at the second mobilization, but the yield of CD34+ cells and GM-CFCs on the first apheresis was significantly greater with the second mobilization than the first. A total yield (all aphereses from both mobilizations) of > 1 x 10(6)/kg CD34+ cells and > 1 x 10(5)/kg GM-CFCs was achieved in 14 out of 20 patients. Seven patients have received high-dose therapy with stem cell infusion; neutrophil recovery was rapid in all patients and platelet independence occurred in < 21 d in five out of seven patients. We conclude that remobilization is worth considering in those patients in whom a chemotherapy-free interval of several months is possible.

Enzymatic kinetic resolution of piperidine atropisomers: synthesis of a key intermediate of the farnesyl protein transferase inhibitor, SCH66336.

The resolution of secondary amines via enzyme-catalyzed acylation is a relatively rare process. The kinetic resolution of a series of intermediates of SCH66336 (1), by either enzymatic acylation of the pendant piperidine (4, 5) or hydrolysis of the corresponding carbamate 3, was investigated. In the case of 4, the molecule exists as a pair of enantiomers due to atropisomerism about the exocyclic double bond. The enzymatic acylation of (+/-)-4 was optimized in terms of acylating agent, solvent, and moisture content. The use of lipase, Toyobo LIP-300, and trifluoroethyl isobutyrate as acylating agent resulted in isobutyrylation of the (+)-enantiomer, which is easily separated from the unwanted (-)-4. Hydrolysis of the isobutyramide 6c yielded the desired (+)-4 in high enantiomeric excess. (-)-4 may be recovered from the resolution step, racemized, and resubjected to enzymatic acylation to increase material throughput.

Biochemical interactions of the neuronal pentraxins. Neuronal pentraxin (NP) receptor binds to taipoxin and taipoxin-associated calcium-binding protein 49 via NP1 and NP2.

Neuronal pentraxin 1 (NP1), neuronal pentraxin 2 (NP2), and neuronal pentraxin receptor (NPR) are members of a new family of proteins identified through interaction with a presynaptic snake venom toxin taipoxin. We have proposed that these three neuronal pentraxins represent a novel neuronal uptake pathway that may function during synapse formation and remodeling. We have investigated the mutual interactions of these proteins by characterizing their enrichment on taipoxin affinity columns; by expressing NP1, NP2, and NPR singly and together in Chinese hamster ovary cells; and by generating mice that fail to express NP1. NP1 and NP2 are secreted, exist as higher order multimers (probably pentamers), and interact with taipoxin and taipoxin-associated calcium-binding protein 49 (TCBP49). NPR is expressed on the cell membrane and does not bind taipoxin or TCBP49 by itself, but it can form heteropentamers with NP1 and NP2 that can be released from cell membranes. This is the first demonstration of heteromultimerization of pentraxins and release of a pentraxin complex by proteolysis. These processes are likely to directly effect the localization and function of neuronal pentraxins in neuronal uptake or synapse formation and remodeling.

The PEP transducer: a new way of measuring respiratory rate in the non-intubated patient.

OBJECTIVES: To explore the use of a pyroelectric polymer (PEP) film as a transducer for a simple respiratory rate monitor and to evaluate the transducer in a laboratory situation. METHODS: Laboratory evaluation of a new pyroelectric transducer for measurement of respiratory rate. RESULTS: The amplified output from the pyroelectric film produced an excellent respiratory trace when used on a normal spontaneously breathing subject. The transducer is cheap, robust, and reliable. CONCLUSIONS: PEP films have the potential to be used as cheap and effective transducers in respiratory rate monitors for non-intubated patients. In the laboratory, they have many desirable characteristics which should now be evaluated in a clinical setting.

Enzymatic glucuronidation of a novel cholesterol absorption inhibitor, Sch 58235.

A glucuronide of a novel cholesterol absorption inhibitor was synthesized on a 200-mg scale in one step via bovine liver glucuronyltransferase-catalyzed coupling of the glucuronyl moiety of UDP-glucuronic acid with the phenolic hydroxyl of Sch 58235. It was shown that the product yield is limited by the hydrolysis of UDP-glucuronic acid by impurities present in the commercial microsomal preparation of the transferase. This detrimental effect of UDPGluA hydrolysis could be diminished by the presence of high concentration of glucuronlytransferase. Optimization of reaction conditions and purification procedure resulted in a process that proceeded with 95% conversion and 88% isolated product yield. The 13C6-glucuronide of Sch 58235 was prepared with the help of a cascade of eight enzymes operating concurrently in one pot.

Conserved active site aspartates and domain-domain interactions in regulatory properties of the sugar kinase superfamily.

The structures of the sugar kinase/heat shock 70/actin superfamily of enzymes show that the active site is located in a deep cleft between two domains whose relative movement defines a domain closure conformational change thought to be involved in the catalytic and regulatory properties of members of the superfamily. To investigate the role of the domain closure in the regulatory behavior, site-directed mutagenesis is used to alter specific domain-domain interactions in Escherichia coli glycerol kinase (EC 2.7.1.30; ATP:glycerol 3-phosphotransferase), a member of this superfamily. Two active site aspartate residues are conserved throughout the superfamily, one (Asp245 in glycerol kinase) which is proposed to act as a general base during catalysis and one (Asp10 in glycerol kinase) which interacts with the Mg(II) ion of the bound Mg(II)-nucleotide complex. Each of these residues participates in domain-domain interactions that are mediated by the bound substrates. The enzymes containing the substitutions Asp245 to Asn (D245N) or Asp10 to Asn (D10N) were purified by affinity chromatography, and the effects of the substitutions on the catalytic properties and regulation by the allosteric effectors, fructose 1,6-bisphosphate (FBP), and the glucose-specific phosphocarrier protein, IIIGlc (also known as IIAGlc), were determined. Each of the residues participates in catalysis; kcat/Katp is decreased 300-fold by the D245N substitution and 100-fold by the D10N substitution. Affinity labeling with the glycerol analog 1,3-dichloroacetone shows that the level of activity seen for the D245N mutant enzyme is not due to deamidation of the substituted asparagine. Each of the substitutions has little effect on regulation by FBP and the apparent affinity for IIIGlc, and the D245N substitution does not affect the extent of inhibition by IIIGlc. However, the D10N substitution decreases the maximum extent of inhibition by IIIGlc from 100 to 60%, thus changing the action of IIIGlc to that of a partial inhibitor. The different sensitivities of the extents of FBP and IIIGlc inhibition to perturbation of a domain-domain interaction mediated by Asp10 suggest that the relations of the actions of these allosteric effectors to the domain closure conformational change are different.

Central neurocytoma: a clinical study of response to chemotherapy.

We report a case of central neurocytoma treated, after an initial partial resection, by chemotherapy, comprising etoposide, ifosfamide and carboplatin. A response was obtained and further treatment was given with surgery and radiotherapy. There have been no previous reports of response to chemotherapy in this relatively rare tumour.