SOX9 modulates cancer biomarker and cilia genes in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive form of cancer with high mortality. The cellular origins of PDAC are largely unknown; however, ductal cells, especially centroacinar cells (CACs), have several characteristics in common with PDAC, such as expression of SOX9 and components of the Notch-signaling pathway. Mutations in KRAS and alterations to Notch signaling are common in PDAC, and both these pathways regulate the transcription factor SOX9. To identify genes regulated by SOX9, we performed siRNA knockdown of SOX9 followed by RNA-seq in PANC-1s, a human PDAC cell line. We report 93 differentially expressed (DE) genes, with convergence on alterations to Notch-signaling pathways and ciliogenesis. These results point to SOX9 and Notch activity being in a positive feedback loop and SOX9 regulating cilia production in PDAC. We additionally performed ChIP-seq in PANC-1s to identify direct targets of SOX9 binding and integrated these results with our DE gene list. Nine of the top 10 downregulated genes have evidence of direct SOX9 binding at their promoter regions. One of these targets was the cancer stem cell marker EpCAM. Using whole-mount in situ hybridization to detect epcam transcript in zebrafish larvae, we demonstrated that epcam is a CAC marker and that Sox9 regulation of epcam expression is conserved in zebrafish. Additionally, we generated an epcam null mutant and observed pronounced defects in ciliogenesis during development. Our results provide a link between SOX9, EpCAM and ciliary repression that can be exploited in improving our understanding of the cellular origins and mechanisms of PDAC.

Conserved Role of the Large Conductance Calcium-Activated Potassium Channel, KCa1.1, in Sinus Node Function and Arrhythmia Risk

BACKGROUND

KCNMA1 encodes the α-subunit of the large-conductance Ca²⁺-activated K⁺ channel, K_Ca1.1, and lies within a linkage interval for atrial fibrillation (AF). Insights into the cardiac functions of K_Ca1.1 are limited, and KCNMA1 has not been investigated as an AF candidate gene.

METHODS

The KCNMA1 gene was sequenced in 118 patients with familial AF. The role of K_Ca1.1 in normal cardiac structure and function was evaluated in humans, mice, zebrafish, and fly. A novel KCNMA1 variant was functionally characterized.

RESULTS

A complex KCNMA1 variant was identified in 1 kindred with AF. To evaluate potential disease mechanisms, we first evaluated the distribution of K_Ca1.1 in normal hearts using immunostaining and immunogold electron microscopy. K_Ca1.1 was seen throughout the atria and ventricles in humans and mice, with strong expression in the sinus node. In an ex vivo murine sinoatrial node preparation, addition of the K_Ca1.1 antagonist, paxilline, blunted the increase in beating rate induced by adrenergic receptor stimulation. Knockdown of the K_Ca1.1 ortholog, kcnma1b, in zebrafish embryos resulted in sinus bradycardia with dilatation and reduced contraction of the atrium and ventricle. Genetic inactivation of the Drosophila K_Ca1.1 ortholog, slo, systemically or in adult stages, also slowed the heartbeat and produced fibrillatory cardiac contractions. Electrophysiological characterization of slo-deficient flies revealed bursts of action potentials, reflecting increased events of fibrillatory arrhythmias. Flies with cardiac-specific overexpression of the human KCNMA1 mutant also showed increased heart period and bursts of action potentials, similar to the K_Ca1.1 loss-of-function models.

CONCLUSIONS

Our data point to a highly conserved role of K_Ca1.1 in sinus node function in humans, mice, zebrafish, and fly and suggest that K_Ca1.1 loss of function may predispose to AF.

Prolonged Exposure to Microgravity Reduces Cardiac Contractility and Initiates Remodeling in Drosophila

Understanding the effects of microgravity on human organs is crucial to exploration of low-earth orbit, the moon, and beyond. Drosophila can be sent to space in large numbers to examine the effects of microgravity on heart structure and function, which is fundamentally conserved from flies to humans. Flies reared in microgravity exhibit cardiac constriction with myofibrillar remodeling and diminished output. RNA sequencing (RNA-seq) in isolated hearts revealed reduced expression of sarcomeric/extracellular matrix (ECM) genes and dramatically increased proteasomal gene expression, consistent with the observed compromised, smaller hearts and suggesting abnormal proteostasis. This was examined further on a second flight in which we found dramatically elevated proteasome aggregates co-localizing with increased amyloid and polyQ deposits. Remarkably, in long-QT causing sei/hERG mutants, proteasomal gene expression at 1g, although less than the wild-type expression, was nevertheless increased in microgravity. Therefore, cardiac remodeling and proteostatic stress may be a fundamental response of heart muscle to microgravity.

Silencing of CCR4-NOT complex subunits affects heart structure and function

The identification of genetic variants that predispose individuals to cardiovascular disease and a better understanding of their targets would be highly advantageous. Genome-wide association studies have identified variants that associate with QT-interval length (a measure of myocardial repolarization). Three of the strongest associating variants (single-nucleotide polymorphisms) are located in the putative promotor region of CNOT1, a gene encoding the central CNOT1 subunit of CCR4-NOT: a multifunctional, conserved complex regulating gene expression and mRNA stability and turnover. We isolated the minimum fragment of the CNOT1 promoter containing all three variants from individuals homozygous for the QT risk alleles and demonstrated that the haplotype associating with longer QT interval caused reduced reporter expression in a cardiac cell line, suggesting that reduced CNOT1 expression might contribute to abnormal QT intervals. Systematic siRNA-mediated knockdown of CCR4-NOT components in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) revealed that silencing CNOT1 and other CCR4-NOT genes reduced their proliferative capacity. Silencing CNOT7 also shortened action potential duration. Furthermore, the cardiac-specific knockdown of Drosophila orthologs of CCR4-NOT genes in vivo (CNOT1/Not1 and CNOT7/8/Pop2) was either lethal or resulted in dilated cardiomyopathy, reduced contractility or a propensity for arrhythmia. Silencing CNOT2/Not2, CNOT4/Not4 and CNOT6/6L/twin also affected cardiac chamber size and contractility. Developmental studies suggested that CNOT1/Not1 and CNOT7/8/Pop2 are required during cardiac remodeling from larval to adult stages. To summarize, we have demonstrated how disease-associated genes identified by GWAS can be investigated by combining human cardiomyocyte cell-based and whole-organism in vivo heart models. Our results also suggest a potential link of CNOT1 and CNOT7/8 to QT alterations and further establish a crucial role of the CCR4-NOT complex in heart development and function.This article has an associated First Person interview with the first author of the paper.

Predation by Engytatus varians (Distant) (Hemiptera: Miridae) on Bactericera cockerelli (Sulcer) (Hemiptera: Triozidae) and two Spodoptera species

Predation by Engytatus varians (Distant) adults on different development stages of the prey species Bactericera cockerelli (Sulcer) (egg, second, and third nymphal instars), Spodoptera exigua (Hübner) and Spodoptera frugiperda (J. E. Smith) (egg, first, and second larval instars) was evaluated using tomato (Solanum lycopersicum L.) leaflets or plants. These insects are the primary pest of several agriculturally important crops. The influence of E. varians age on the predation capacity was also analysed. Engytatus varians females consumed significantly more B. cockerelli eggs and nymphs than males. Additionally, female predators consumed significantly more second than third instar prey at two predator ages, while males consumed significantly more the second instar than third instar prey at all predator ages. In most of the cases, females also consumed significantly more S. exigua and S. frugiperda eggs than males; however, in terms of larvae consumption, this difference was observed only in some predator ages. Females consumed more the first than second instar S. exigua than males, whereas this behaviour was only observed in males when the predators were 15 and 17 days old. No significant differences were observed in the consumption of first and second instar of S. frugiperda for both sexes of the predators. Predator age did not cause any systematic effects on the predation rates of any prey species. Based on these results, we confirmed that E. varians has potential as a biological control agent for B. cockerelli and also for the Spodoptera species bioassayed.

Extraction of source functions of surface photovoltage transients at very short times

The measurement of surface photovoltage (SPV) transients over 12 orders of magnitude in time was recently demonstrated [Rev. Sci. Instrum. 88, 053904 (2017)]. In dedicated experiments, however, a high-impedance buffer shall be placed outside the measurement chamber, which has consequences for SPV measurements at very short times. By varying the LCR circuit of a measurement configuration, applying a multi-parameter fit and simulating the corresponding SPV transients, we show, on the examples of highly doped silicon and a CdS thin film, that the source function of SPV transients can be reconstructed with a resolution time better than 1 ns.

The HAND1 frameshift A126FS mutation does not cause hypoplastic left heart syndrome in mice

Aims

To test if a human Hand1 frame shift mutation identified in human samples is causative of hypoplastic left heart syndrome (HLHS).

Methods and results

HLHS is a poorly understood single ventricle congenital heart defect that affects two to three infants in every 10 000 live births. The aetiologies of HLHS are largely unknown. The basic helix-loop-helix transcription factor HAND1 is required for normal heart development. Interrogation of HAND1 sequence from fixed HLHS tissues identified a somatic frame-shift mutation at Alanine 126 (NP_004812.1 p.Ala126Profs13X defined as Hand1A126fs). Hand1A126fs creates a truncated HAND1 protein that predictively functions as dominant negative. To determine if this mutation is causative of HLHS, we engineered a conditional Hand1A126fs mouse allele. Activation of this allele with Nkx2.5Cre results in E14.5 lethality accompanied by cardiac outflow tract and intraventricular septum abnormalities. Using αMHC-Cre or Mef2CAHF-Cre to activate Hand1A126fs results in reduced phenotype and limited viability. Left ventricles of Hand1A126FS mutant mice are not hypoplastic.

Conclusions

Somatically acquired Hand1A126FS mutation is not causative of HLHS. Hand1A126FS mutation does exhibit embryonic lethal cardiac defects that reflect a dominant negative function supporting the critical role of Hand1 in cardiogenesis.

Genetic and Biological Characterization of Four Nucleopolyhedrovirus Isolates Collected in Mexico for the Control of Spodoptera exigua (Lepidoptera: Noctuidae)

This study describes four multiple nucleocapsid nucleopolyhedrovirus isolates recovered from infected larvae of beet armyworm, Spodoptera exigua (Hübner) (Lepidoptera: Noctuidae), on crops in two different geographical regions of Mexico. Molecular and biological characterization was compared with characterized S. exigua multiple nucleopolyhedrovirus (SeMNPV) isolates from the United States (SeUS1 and SeUS2) and Spain (SeSP2). Restriction endonuclease analysis of viral DNA confirmed that all Mexican isolates were SeMNPV isolates, but molecular differences between the Mexican and the reference isolates were detected using PCR combined with restriction fragment length polymorphism (RFLP). Amplification of the variable region V01 combined with RFLP distinguished the two Mexican isolates, SeSLP6 and SeSIN6. BglII digestions showed that the majority of the isolates contained submolar bands, indicating the presence of genetic heterogeneity. Amplification of the variable regions V04 and V05 distinguished between American and the Spanish isolates. Biological characterization was performed against two laboratory colonies of S. exigua, one from Mexico, and another from Switzerland. Insects from the Mexican colony were less susceptible to infection than insects from Se-Swiss colony. In the Se-Mex colony, SeSP2 was the most pathogenic isolate followed by SeSIN6, although their virulence was similar to most of the isolates tested. In Se-Swiss colony, similar LD50 values were observed for the five isolates, although the virulence was higher for the SeSLP6 isolate, which also had the highest OB (occlusion body) yield. We conclude that the Mexican isolates SeSIN6 and SeSLP6 possess insecticidal traits of value for the development of biopesticides for the control of populations of S. exigua.

Age-dependent electrical and morphological remodeling of the Drosophila heart caused by hERG/seizure mutations

Understanding the cellular-molecular substrates of heart disease is key to the development of cardiac specific therapies and to the prevention of off-target effects by non-cardiac targeted drugs. One of the primary targets for therapeutic intervention has been the human ether a go-go (hERG) K⁺ channel that, together with the KCNQ channel, controls the rate and efficiency of repolarization in human myocardial cells. Neither of these channels plays a major role in adult mouse heart function; however, we show here that the hERG homolog seizure (sei), along with KCNQ, both contribute significantly to adult heart function as they do in humans. In Drosophila, mutations in or cardiac knockdown of sei channels cause arrhythmias that become progressively more severe with age. Intracellular recordings of semi-intact heart preparations revealed that these perturbations also cause electrical remodeling that is reminiscent of the early afterdepolarizations seen in human myocardial cells defective in these channels. In contrast to KCNQ, however, mutations in sei also cause extensive structural remodeling of the myofibrillar organization, which suggests that hERG channel function has a novel link to sarcomeric and myofibrillar integrity. We conclude that deficiency of ion channels with similar electrical functions in cardiomyocytes can lead to different types or extents of electrical and/or structural remodeling impacting cardiac output.

We have used the fruit fly cardiac model to show that seizure, the fly homolog of the human ether a go-go K⁺ channel hERG, is functional in the fly heart. This channel plays a major role in cardiac repolarization in humans but not in adult rodent hearts. Loss of channel function in the fly causes bradycardia, electrical arrhythmia and altered myofibrillar structure. Gene expression analysis indicates that Wnt signaling is affected and we show a genetic interaction between sei and pygopus, a Wnt pathway component, on heart function.

FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

BACKGROUND

Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium.

METHODS

Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression.

RESULTS

Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95% confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2.

CONCLUSION

Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2.

P2-12-01: Immunohistochemical (IHC) BAG1 Expression Improves the Estimation of Residual Risk (RR) by IHC4 in Postmenopausal Patients Treated with Anastrozole or Tamoxifen: A TransATAC Study

Aim: To determine whether the incorporation of BAG1 staining improves the estimate of RR after endocrine therapy in postmenopausal patients with ER+ve tumours treated with endocrine therapy. Background: BAG1 encodes a protein (BCL2-associated athanogene 1) that binds to BCL2 and enhances its anti-apoptotic effects. BAG1 is included as a separate subgroup in the 21-gene OncotypeDx Recurrence Score (RS) that is used to assess RR after endocrine therapy in primary ER+ breast cancer. IHC4 is a 4-panel set of IHC markers (ER, PgR, HER2, Ki67) that was shown to provide as much prognostic accuracy as RS in the translational arm of the ATAC trial (TransATAC) of anastrozole versus tamoxifen alone or combined and subsequently independently validated (Cuzick et al, JCO, 2011, in press). Addition of extra markers such as BAG1 to IHC4 may improve the accuracy of the IHC4 and provide extra discriminatory power for oncologists.

Methods: Samples in triplicate TMAs from the TransATAC cohort were stained for BAG1 using the Genetex 3.10G3E2 antibody after validation using siRNA knockdown. Staining was scored separately as nuclear or cytoplasmic and categorized by intensity as 0, 1, 2 or 3. BAG1 IHC values were assessed for their correlation with BAG1 mRNA levels. The statistical analysis plan was pre-specified and tested possible additional information from BAG1 expression to the IHC4 in patients not treated with chemotherapy by change in the likelihood ratio chi-square (ΔLR-X2). Results were included only if there was also complete data for ER, PgR, Ki67 and HER2. Primary analysis was on the HER2−ve node-negative (N-neg) population; secondary analysis was on all N-neg patients. Follow-up was to 10 years and the primary end-point was time to distant recurrence (TTDR).

Results: Data on both nuclear and cytoplasmic BAG1 as well as the other 4 IHC parameters was available on 961 cases of which 855 were HER2−ve. There was a significant correlation between cytoplasmic and nuclear BAG1 (p=0.23, p<0.0001) but the nuclear staining correlated better with mRNA levels and was therefore considered further. Weak but significant correlations were also seen with ER, PgR and tumour grade. In the univariate analysis nuclear BAG1 was significantly associated with worse TTDR in HER2−ve and all N-neg cases (X2=7.91, p=0.005 and X2=10.63, p=0.001 respectively). Nuclear BAG1 also contributed significantly in multivariate analyses in the 2 populations firstly when added to the clinical model (X2=4.99, p=0.02 and X2=5.93, p=0.015 respectively) and secondly when subtracted from clinical plus the IHC4 parameters (X2=5.55, p=0.02 and X2=4.50, p=0.03 respectively).

Conclusions: Nuclear BAG1 expression has significant value for estimating RR that is independent of standard clinical and IHC parameters and it improves the prediction of TTDR in the TransATAC population beyond that with the validated IHC4 score. Unlike IHC4 markers, BAG1 is not commonly measured in pathology work-up of breast cancers. The clinical utility of its addition to IHC4 will be tested by measuring its discrimination of high and low risk patients in clinical practice.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-12-01.

Predictive algorithms for adjuvant therapy: TransATAC

Estrogen receptor (ER) positive primary breast cancers have a wide range of clinical outcomes. Prediction of the likely course of the disease aids treatment decision-making. In the translational arm of the ATAC (anastrozole or tamoxifen alone or combined) trial (TransATAC) we have assessed individual and multiparameter biomarkers for their prediction of overall and distant recurrence. None of the biomarkers identified differential benefit for anastrozole versus tamoxifen. Each of ER, PgR, HER2 and Ki67 was associated with risk of recurrence. A combination of these to create a single predictor IHC4 was as informative as the 21-gene recurrence score (RS). Integration of each of these molecular profiles with classical clinicopathologic variables provided the most accurate prediction of outcome.

Lethal and sublethal effects of methoxyfenozide on the development, survival and reproduction of the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae)

The lethal and sublethal effects of the ecdysone agonist methoxyfenozide on the fall armyworm, Spodoptera frugiperda (J. E. Smith), were investigated by feeding a methoxyfenozide-treated diet to fifth instars until pupation in doses corresponding to the LC10 and LC25 for the compound. Larval mortality reached 8% and 26% in the low and high concentration groups, respectively, on the seventh day of the experiment. A progressive larval mortality of 12% for the LC10 and 60% for the LC25 was observed before pupation. Treated larvae exhibited lower pupal weights, higher pupal mortality, presence of deformed pupae, and more deformed adults than untreated larvae. The incorporation of methoxyfenozide into the diet had a significant effect on the timing of larval development. The development period for males and females was about seven days longer than the controls for both concentrations tested. In contrast, the compound affected neither pupae nor adult longevity. Finally, S. frugiperda adults that resulted from fifth instars treated with methoxyfenozide were not affected in their mean cumulative number of eggs laid per female (fecundity), nor percentages of eggs hatched (fertility), or the sex ratio. Our results suggest that the combination of lethal and sublethal effects of methoxyfenozide may have important implications for the population dynamics of the fall armyworm.

Impact of glyphosate on the development, fertility and demography of Chrysoperla externa (Neuroptera: Chrysopidae): ecological approach

Few ecotoxicological studies have used life table analysis to evaluate the toxicity of pesticides on beneficial organisms. This study is the first report of the effect of the herbicide glyphosate on a predator insect, Chrysoperla externa, using a demographic approach. This predator is associated to soybean pests and has a potential role as a biological control agent in the Neotropical Region. The objective of this work was to evaluate the side-effects of glyphosate on the development, fertility and demography of C. externa, treated orally by ingestion of glyphosate-dipped eggs of Sitotroga cerealella in laboratory conditions. The data were analyzed using the age-stage, two-sex life table. Development from third larval instar to pupae and adult longevity were shorter in glyphosate-treatment than in the control. Adult pre-reproductive period was longer in glyphosate-treatment than in the control. Fecundity and fertility were deeply reduced, as well, being fertility greater affected. A high important reduction was registered in all population parameters. Most eggs from glyphosate-treated cohort looked abnormal, smaller than control, dehydrated and became black 2d after oviposition. In addition, adults developed tumours in the abdomen region at 20d after emergence, being the effect more drastic in females than males. It is beyond the scope of our study to speculate on the effects of this herbicide on C. externa field populations. However, it seems likely that populations under continuous use of glyphosate would be exposed at greater detrimental effects in the long term.

Effects of larval exposure to sublethal concentrations of methoxyfenozide in Spodoptera frugiperda (J.E. Smith)

Methoxyfenozide is an ecdysone agonist, the most new class of insect growth regulators. Most studies of the toxicity of ecdysone agonists on lepidopteran pests have been conducted during the larval stages, and little has been published regarding its sublethal effects in the surviving individuals. In this study, the lethal and sublethal effects of methoxyfenozide on the fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) were assessed. For this, fifth instars of this pest were continuously fed, until pupation, with artificial diet containing 0.24 and 0.35 mg of active ingredient/kg diet, which correspond to the LC10 and LC25 values, respectively, for this insecticide. Larval mortality reached 8% and 26% in the low and high concentration groups, respectively, on the seventh day of the experiment. A progressive larval mortality of 12% for the LC10 and 60% for the LC25 was observed before pupation. Treated larvae exhibited lower pupal weights, higher pupal mortality, presence of deformed pupae, and more deformed adults than untreated larvae. The incorporation of methoxyfenozide into the diet had a significant effect on the timing of larval development. Both male and female treated larvae lived about seven days longer than the controls for both concentrations tested. Finally, S. frugiperda adults that resulted from fifth instars treated with methoxyfenozide were not affected in their sex ratio. Our results suggest that the combination of lethal and sublethal effects of methoxyfenozide may have important implications for the population dynamics of the fall armyworm.

Effects of optical brighteners used in biopesticide formulations on crops: reflectance, stomatal conductance, photosynthesis, and growth

Optical brighteners have attracted interest as adjuvant's in baculovirus-based biological insecticides due to their ability enhance the insecticidal properties of these viruses and protect virus particles from the degrading effects of ultraviolet (UV) radiation. The effects of two types of optical brighteners, Tinopal CBS (a distyryl-biphenyl derivative) and Tinopal C1101 (an ethenediyl benzenesulfonic derivative) at 1 or 3% (wt./vol.), on growth of different crOPs [maize, Zea mays L. (var. HY-311), sorghum, Sorghum vulgare Pers. (var. Silo), tomato, Lycopersicum esculentum L. (var. Floradade IT), or pepper, Capsicum annum L. (var. Cal Won 300)] were examined after once a week application during four weeks. Both compounds significantly affected the growth of maize plants, whereas sorghum plants were affected only at the highest concentration of Tinopal C1101. Neither brightener had negative effects on tomato or peppers plants. Both compounds increased the percentage of reflectance of maize and tomato leaves when analyzed using laboratory and field spectrophotometers. A greenhouse experiment involving single application of 1 and 3% Tinopal C1101 indicated that the stomatal conductance and photosynthetic rate of maize and tomato plants were not significantly affected. We conclude that the effects of optical brighteners on plant growth are more likely to be influenced by differences between plant species than differences between brightener compounds.

A large Legionnaires' disease outbreak in Pamplona, Spain: early detection, rapid control and no case fatality

An outbreak of Legionnaire's disease was detected in Pamplona, Spain, on 1 June 2006. Patients with pneumonia were tested to detect Legionella pneumophila antigen in urine (Binax Now; Binax Inc., Scarborough, ME, USA), and all 146 confirmed cases were interviewed. The outbreak was related to district 2 (22 012 inhabitants), where 45% of the cases lived and 50% had visited; 5% lived in neighbouring districts. The highest incidence was found in the resident population of district 2 (3/1000 inhabitants), section 2 (14/1000). All 31 cooling towers of district 2 were analysed. L. pneumophila antigen (Binax Now) was detected in four towers, which were closed on 2 June. Only the strain isolated in a tower situated in section 2 of district 2 matched all five clinical isolates, as assessed by mAb and two genotyping methods, AFLP and PFGE. Eight days after closing the towers, new cases ceased appearing. Early detection and rapid coordinated medical and environmental actions permitted immediate control of the outbreak and probably contributed to the null case fatality.

Statin enhancement of collateralization in acute stroke

Collateral circulation influences cerebral infarction occurrence and size. Statins may improve ischemic stroke outcomes. We evaluated the relationship between prestroke statin use and pretreatment angiographic collateral grade among acute ischemic stroke patients presenting with occlusion of a major cerebral artery. After adjusting for covariates, the statin-treated group had significantly higher collateral scores than non-statin users, suggesting an association between statin use and better collateralization during acute stroke.

Optical brightener Tinopal C1101 as an ultraviolet protectant for a nucleopolyhedrovirus

Baculoviruses are arthropod-specific viruses currently used as biological insecticides in several countries of the world. One important factor limiting the efficacy of these bioinsecticides is related to the inactivation of the virus by solar ultraviolet (UV) radiation. This has motivated studies focused on the use of optical brightener compounds that can protect the virus from UV inactivation. The effects of the optical brightener Tinopal C1101 (ethenedyl benzenesulfonic derivative) on the persistance of a nucleopolyhedrovirus (SfMNPV) was quantified in third instar Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), the principal pest of maize in the Americas. For this, laboratory studies were performed to determine the relationship between virus concentrations and radiation-caused inactivation of SfMNPV alone or in mixtures with 1.25 or 0.1% (vol/vol) Tinopal C1101 using a UV system [radiation was provided by a 15 W UV tube (emission maxima at 312 nm)]. SfMNPV alone was more sensitive to UV than in mixtures with 1.25 or 0.1% Tinopal C1101. For instance, at concentrations of 2.22 x 10(8) and 2.75 x 10(6) occlusion bodies (OBs)/ml, SfMNPV alone-caused mortality was reduced from 88 and 44% (without UV radiation) to 0%, in both cases, after 30 and 15 min exposure to the UV tube, respectively. In contrast, the incorporation of 1.25% Tinopal C1101 into the SfMNPV inoculum at 2.22 x 10(8) and 2.75 x 10(6) OBs/ml caused a mortality of 86.6 and 96.6% after 240 min, respectively. UV-caused inactivation of SfMNPV was directly related to the optical brightener concentration. We conclude that optical brighteners are likely to represent valuable components of nucleopolyhedrovirus formulations.

Sublethal effects of two neurotoxican insecticides on Araneus pratensis (Araneae: Araneidae)

Spiders are important predators of several agricultural pests and they play an important role as indicators of ecosystem disturb. In Argentina, soybean crop has increased from the introduction of transgenic soybean resistant to glyphosate. This expansion produced an increase in the use of conventional and non-selective pesticides to control soybean pests. The objective of this work was to evaluate the side effects of subletal concentrations of two neurotoxican insecticides with a different mode of action: endosulfan (Glex, 35%, 25 mg/l a.i.) and spinosad (Tracer, 48%, 30 and 3 mg/l a.i) on Araneus pratensis. The insecticides were applied by ingestion of the treated prey (Musca domestica), and the effects on mortality, prey consumption, web building, mating, ootheca construction and fecundity were determined. Spinosad (30 mg/l a.i.) produced higher mortality than endosulfan (25 mg/l a.i.). Tremors and non-coordinated movements were observed in this treatment. The prey consumption was significantly reduced by the two insecticides (approximately 40% lower than control). The spider web building was significantly affected by the two insecticides, but spinosad had a greater effect. Though mating was not affected by both pesticides, abnormal oothecas and dehydrated eggs were observed. This work reports that sublethal concentrations representing approximately from 25 to 2.5% of the maximum field recommended concentrations (105 and 120 mg/l a.i., respectively) showed negative effects on A. pratensis. The consequences of these effects on role of A. pratensis as a natural mortality factor of soybean pests are discussed.

Conditioning the unconditioned response: modification of the rabbit's (Oryctolagus cuniculus) unconditioned nictitating membrane response

Conditioning-specific reflex modification (CRM) occurs when classical conditioning modifies responding to an unconditioned stimulus (US) in the absence of a conditioned stimulus (CS). Three experiments monitored rabbit nictitating (Oryctolagus cuniculus) membrane unconditioned responses to 5 intensities and 4 durations of periorbital electrical stimulation before and after CS or US manipulation. CRM occurred after 12 days of CS-US pairings but not following unpaired CS/US presentations or restraint. CRM survived CS-alone and CS/US-unpaired extinction of the conditioned response (CR) but not presentations of the US alone, although CRs remained intact. Thus, CRs could be weakened without eliminating CRM and CRM could be weakened without eliminating CRs. Data indicate CRM is a reliable, associative effect that is more than a generalized CR and may not be explained by habituation, stimulus generalization, contextual conditioning, or bidirectional conditioning.

Conditioning the unconditioned response: modification of the rabbit's (Oryctolagus cuniculus) unconditioned nictitating membrane response

Conditioning-specific reflex modification (CRM) occurs when classical conditioning modifies responding to an unconditioned stimulus (US) in the absence of a conditioned stimulus (CS). Three experiments monitored rabbit nictitating (Oryctolagus cuniculus) membrane unconditioned responses to 5 intensities and 4 durations of periorbital electrical stimulation before and after CS or US manipulation. CRM occurred after 12 days of CS-US pairings but not following unpaired CS/US presentations or restraint. CRM survived CS-alone and CS/US-unpaired extinction of the conditioned response (CR) but not presentations of the US alone, although CRs remained intact. Thus, CRs could be weakened without eliminating CRM and CRM could be weakened without eliminating CRs. Data indicate CRM is a reliable, associative effect that is more than a generalized CR and may not be explained by habituation, stimulus generalization, contextual conditioning, or bidirectional conditioning.

[3H]Paroxetine binding to human peripheral lymphocyte membranes of patients with major depression before and after treatment with fluoxetine

Serotonin has been involved in major depression and is also related to central and peripheral mechanisms of neuroimmunomodulation. Recently, the uptake of [3H]serotonin into human peripheral blood lymphocytes has been reported. We determined the density of serotonin uptake sites by the binding of [3H]paroxetine to blood peripheral lymphocyte membrane preparations of controls and of patients with major depression before and after treatment with fluoxetine for six weeks. The severity of depression was assessed by the use of Hamilton Rating Scale for Depression and of Beck Depression Inventory. There was a reduction in the number of sites for [3H]paroxetine in patients before administration of the antidepressant respecting controls, and a recovery after the treatment. Affinity was unchanged. No correlation was obtained between the severity of symptoms determined by Hamilton Rating Scale for Depression or by Beck Depression Inventory, and the number of binding sites for [3H]paroxetine. The levels of the plasma serotonin metabolite, 5-hydroxyindoleacetic acid, did not differ between the three groups of subjects, but serotonin was lower in patients after treatment respecting controls and in patients before treatment. The significant correlation between specific binding of [3H]paroxetine and plasma serotonin levels in controls was not present in the patients. Lymphocyte serotonin transporter is decreased in major depressed patients and is modulated by antidepressant treatment. In addition of counting with a peripheral marker in depression, the study of serotonin system in lymphocytes might contribute to understand the bi-directional interaction between the nervous and the immune systems.

Biomechanical, radiologic, and histopathologic correlations in the pathogenesis of experimental intervertebral disc disease

STUDY DESIGN

The desert sand rat, an animal model for spinal degenerative disc disease, was studied for biomechanical, histologic, and radiographic characteristics. Load deformation curves with peak force and force decay, hematoxylin-eosin-stained sections, and lateral radiographs were correlated.

OBJECTIVES

The hypothesis that the subchondral bone response preceded or contributed to the degenerative disc disease seen in the desert sand rat was tested.

SUMMARY OF BACKGROUND DATA

Intervertebral disc disease spontaneously develops in the desert sand rat during its lifetime. Approximately 50% will have significant disc disease by age 18 months. Previous studies have found metabolic and histologic changes associated with intervertebral disc degeneration in the sand rat.

METHODS

Desert sand rats were killed at 3-, 9-, 15-, and 18-month intervals and tested in Rheometrics Solid Analyzer with nondestructive step strain loading to obtain a load deformation curve. Radiographs and histologic sections of each animal were compared. Peak force and force decay were analyzed by level and by age. Analysis of variance and Tukey's methods were applied to data.

RESULTS

There were no statistically significant differences in biomechanical data. No histologic changes were noted in the study groups up to 18 months of age. Radiographic differences characterized by subchondral bony sclerosis were noted by 18 months of age. No trends were noted when radiographic grades were compared with force data.

CONCLUSIONS

The absence of biomechanical histologic changes in the intervertebral disc per se from 3 through 18 months, with radiographic changes in the subchondral bone, supports the hypothesis that the earliest changes in intervertebral disc disease in this animal model are related to the subchondral bone response.

[Risk of low birth weight in the Plaza de la Habana region]

The objective of this study was to confirm the risk factors (RF) for low birth-weight (LBW) and suggest new risk factors, which were analyzed separately and together, in order to define a program to be coordinated by family doctors to reduce the frequency of this problem. For this purpose, a retrospective cross-sectional survey was carried out with 57 cases (mothers who had had LBW babies) and 58 controls (mothers who had not had LBW babies). In addition, data were obtained from the prenatal records of mothers who received care at family doctors' offices and at the clinica in the Plaza de la Habana Area. Estimates were made of the relative risk and the percentage attributable risk of 107 hypothetical RF for LBW from a clinical-epidemiological and social standpoint. One-way analysis of variance, the chi-square test, multiple linear regression, and logistic regression were used to analyze the results, which suggested the following RF for LBW: family dysfunction, family crisis, lack of spousal support, extended family, failure to attend prenatal group sessions for pregnant women, and failure to receive education on how to prevent LBW. The multifactorial risk profile was the following: risk of [corrected] intrauterine growth retardation, family dysfunction, threat of preterm delivery, coffee-drinking, attendance at fewer than 11 prenatal checkups, and failure to attend prenatal group sessions for pregnant women. The variables excluded from the model were: low weight-for-height, lack of spousal support, smoking more than 10 cigarettes a day, and family history of LBW. The findings confirmed 10 of the suspected risk factors for LBW in Cuba and nine of those described in the international literature. Maternal age, spontaneous abortion, and alcohol consumption were not confirmed. Six RF for LBW preventable by the family doctor through his/her actions at the family and community level are identified, as is a multifactorial profile of six RF for LBW. On the basis of these results, proposals are made in regard to programming priorities and the implementation of strategies aimed at preventing LBW, and it is recommended that the study be continued with a larger sample.

A semiquantitative scale for histologic grading of articular cartilage repair

This laboratory has developed a semiquantitative scale for grading the natural healing process of defects drilled into articular cartilage. The scale is composed of four parameters: percent filling of the defect, reconstitution of the osteochondral junction, matrix staining and cell morphology; it has a score range from 0 (best) to 14 (worst). The scale was used to evaluate the healing of defects drilled into rabbit knee articular cartilage at 2, 14, 30, 60 and 120 days after surgery. No statistically significant difference in the graded score was found between the two different defect sizes (2.7 and 1.5 mm). However, the differences in score observed between specimens from different sacrifice times were significant (p less than 0.01). Currently many investigators are manipulating cartilaginous lesions in an attempt to improve healing, and this scale will provide a means for quantitatively comparing results from control and experimental groups.