Histologic Parameters Predictive of Disease Outcome in Women with Advanced Stage Ovarian Carcinoma Treated with Neoadjuvant Chemotherapy

The use of neoadjuvant chemotherapy followed by tumor reduction surgery, also called interval debulking surgery (IDS), is considered an alternative therapeutic regimen for selected patients with advanced stage epithelial ovarian cancer (EOC). Although minimal residual disease has been proven to be a prognostic factor in traditional cytoreduction for advanced stage EOC, predictive factors after IDS still remain unexplored. The aim of this study was to determine the prognostic value of post-neoadjuvant histologic changes with clinical outcome. Three pathologists evaluated 67 cases for the following parameters: fibrosis, necrosis, residual tumor, and inflammation. The Cohen's kappa statistic was used to measure agreement among pathologists. Univariate and multivariate Cox proportional hazards models were used to determine the association between histologic parameters and recurrence-free survival (RFS) and overall survival (OS). There was substantial to almost perfect agreement among the three pathologists in all four histologic parameters (k ranged from 0.65 to 0.97). Fibrosis was associated with longer RFS (P = 0.0257) with a median of [20]months for tumors with fibrosis (3+) versus 12 months for tumors with fibrosis (1+, 2+) and longer OS (P = 0.0249) with a median of 51 months for tumors with fibrosis (3+) versus 32 months for tumors with fibrosis (1+, 2+). Our results revealed that patients with tumors exhibiting fibrosis (1+, 2+), as well as necrosis (0, 1+), had significant shorter RFS and OS (P = 0.059 and P = 0.0234, respectively). We suggest that the assessment of fibrosis and necrosis should be implemented in pathologic evaluation and prospectively validated in future studies.     

Use of Bacteroidales Microbial Source Tracking To Monitor Fecal Contamination in Fresh Produce Production

In recent decades, fresh and minimally processed produce items have been associated with an increasing proportion of food-borne illnesses. Most pathogens associated with fresh produce are enteric (fecal) in origin, and contamination can occur anywhere along the farm-to-fork chain. Microbial source tracking (MST) is a tool developed in the environmental microbiology field to identify and quantify the dominant source(s) of fecal contamination. This study investigated the utility of an MST method based on Bacteroidales 16S rRNA gene sequences as a means of identifying potential fecal contamination, and its source, in the fresh produce production environment. The method was applied to rinses of fresh produce, source and irrigation waters, and harvester hand rinses collected over the course of 1 year from nine farms (growing tomatoes, jalapeño peppers, and cantaloupe) in Northern Mexico. Of 174 samples, 39% were positive for a universal Bacteroidales marker (AllBac), including 66% of samples from cantaloupe farms (3.6 log₁₀ genome equivalence copies [GEC]/100 ml), 31% of samples from tomato farms (1.7 log₁₀ GEC/100 ml), and 18% of samples from jalapeño farms (1.5 log₁₀ GEC/100 ml). Of 68 AllBac-positive samples, 46% were positive for one of three human-specific markers, and none were positive for a bovine-specific marker. There was no statistically significant correlation between Bacteroidales and generic Escherichia coli across all samples. This study provides evidence that Bacteroidales markers may serve as alternative indicators for fecal contamination in fresh produce production, allowing for determination of both general contamination and that derived from the human host.     

Essential role of caveolae in interleukin-6- and insulin-like growth factor I-triggered Akt-1-mediated survival of multiple myeloma cells

Caveolae, specialized flask-shaped lipid rafts on the cell surface, are composed of cholesterol, sphingolipids, and structural proteins termed caveolins; functionally, these plasma membrane microdomains have been implicated in signal transduction and transmembrane transport. In the present study, we examined the role of caveolin-1 in multiple myeloma cells. We show for the first time that caveolin-1, which is usually absent in blood cells, is expressed in multiple myeloma cells. Analysis of myeloma cell-derived plasma membrane fractions shows that caveolin-1 is co-localized with interleukin-6 receptor signal transducing chain gp130 and with insulin-like growth factor-I receptor. Cholesterol depletion by beta-cyclodextrin results in the loss of caveola structure in myeloma cells, as shown by transmission electron microscopy, and loss of caveolin-1 function. Interleukin-6 and insulin-like growth factor-I, growth and survival factors in multiple myeloma, induce caveolin-1 phosphorylation, which is abrogated by pre-treatment with beta-cyclodextrin. Importantly, inhibition of caveolin-1 phosphorylation blocks both interleukin-6-induced protein complex formation with caveolin-1 and downstream activation of the phosphatidylinositol 3-kinase/Akt-1 pathway. beta-Cyclodextrin also blocks insulin-like growth factor-I-induced tyrosine phosphorylation of insulin-responsive substrate-1 and downstream activation of the phosphatidylinositol 3-kinase/Akt-1 pathway. Therefore, cholesterol depletion by beta-cyclodextrin abrogates both interleukin-6- and insulin-like growth factor-I-triggered multiple myeloma cell survival via negative regulation of caveolin-1. Taken together, this study identifies caveolin-1 and other structural membrane components as potential new therapeutic targets in multiple myeloma.     

Prader-Willi Syndrome: Relationship of Adiposity to Plasma Leptin Levels

Objective : Prader-Willi syndrome (PWS) is an autosomal dominant disorder involving the proximal long arm of chromosome 15, in which obesity is common. However, there is limited information on the underlying physiological mechanisms promoting obesity in this population. We tested whether there was a significant positive association between leptin and total body fat (TBF) in subjects with PWS, and whether this association was stronger among subjects with than without PWS. Research Methods and Procedures : We studied 21 PWS patients and 64 non-PWS controls on whom we measured serum leptin, total body fat, glucose, insulin, and resting energy expenditure. We tested whether the slope of the regression line between leptin and TBF (in kg), measured by dual energy X-ray absorptiometry, was the same for PWS patients and aon-PWS controls. Results : Regression analyses indicated that the leptin-TBF association was significantly stronger among PWS patients. In contrast, the slope of the leptin-body mass index association did not significantly differ between PWS patients and non-PWS controls. None of the other outcome variables showed associations with leptin. Discussion : Results suggest that the role of leptin in promoting obesity may be greater among subjects with PWS than among non-PWS controls.     

Discovery and characterization of the N-phenyl-N′-naphthylurea class of p38 kinase inhibitors

An effort aimed at exploring structural diversity in the N-pyrazole-N′-naphthylurea class of p38 kinase inhibitors led to the synthesis and characterization of N-phenyl-N′-naphthylureas. Examples of these compounds displayed excellent inhibition of TNF-α production in vitro, as well as efficacy in a mouse model of lipopolysaccharide induced endotoxemia. In addition, perspective is provided on the role of a sulfonamide functionality in defining inhibitor potency.     

Haemoglobin C and S role in acquired immunity against Plasmodium falciparum malaria

A recently proposed mechanism of protection for haemoglobin C (HbC; beta6Glu-->Lys) links an abnormal display of PfEMP1, an antigen involved in malaria pathogenesis, on the surface of HbC infected erythrocytes together with the observation of reduced cytoadhesion of parasitized erythrocytes and impaired rosetting in vitro. We investigated the impact of this hypothesis on the development of acquired immunity against Plasmodium falciparum variant surface antigens (VSA) encoding PfEMP1 in HbC in comparison with HbA and HbS carriers of Burkina Faso. We measured: i) total IgG against a single VSA, A4U, and against a panel of VSA from severe malaria cases in human sera from urban and rural areas of Burkina Faso of different haemoglobin genotypes (CC, AC, AS, SC, SS); ii) total IgG against recombinant proteins of P. falciparum asexual sporozoite, blood stage antigens, and parasite schizont extract; iii) total IgG against tetanus toxoid. Results showed that the reported abnormal cell-surface display of PfEMP1 on HbC infected erythrocytes observed in vitro is not associated to lower anti- PfEMP1 response in vivo. Higher immune response against the VSA panel and malaria antigens were observed in all adaptive genotypes containing at least one allelic variant HbC or HbS in the low transmission urban area whereas no differences were detected in the high transmission rural area. In both contexts the response against tetanus toxoid was not influenced by the beta-globin genotype. These findings suggest that both HbC and HbS affect the early development of naturally acquired immunity against malaria. The enhanced immune reactivity in both HbC and HbS carriers supports the hypothesis that the protection against malaria of these adaptive genotypes might be at least partially mediated by acquired immunity against malaria.     

Plant phylogeny as a surrogate for turnover in beetle assemblages

The ability to extrapolate from the known to the unknown is essential if we are to use the turnover of overall biodiversity, as opposed to a few well-known groups, to inform conservation planning. We investigated the usefulness of using evolutionary relationships of plants as a surrogate for the turnover of their associated beetle assemblages. If plant traits that are important to insects are phylogenetically conserved, it follows that there will be a positive relationship between insect faunal dissimilarity and plant evolutionary distance. We collected beetles using pyrethrum knock-down methods from 40 plant species belonging to four plant families in the Sydney region of Eastern Australia. We developed a novel approach for estimating variance in the dissimilarity of beetle assemblages, as explained by plant phylogeny, by using phylogenetic eigenvectors as explanatory variables in a distance-based redundancy analysis. We found a highly significant relationship between faunal dissimilarity and plant evolutionary distance for the entire beetle assemblage, the herbivorous component, and the non-herbivorous component, indicating that beetles generally showed some preference for particular plant clades as habitat, regardless of feeding guild. When comparing observed dissimilarities with those predicted from 40 jack-knife replicates of a Generalised Dissimilarity Model, we were often able to predict beetle turnover from plant phylogenetic relationships, although the reliability of this result was highly variable. Nevertheless, the broad response of beetle assemblages to plant evolutionary relatedness indicates real potential for plant phylogenetic pattern to act as a useful surrogate for insect biodiversity, especially when supplemented with other environmental correlates.     

Do ants make direct comparisons?

Many individual decisions are informed by direct comparison of the alternatives. In collective decisions, however, only certain group members may have the opportunity to compare options. Emigrating ant colonies (Temnothorax albipennis) show sophisticated nest-site choice, selecting superior sites even when they are nine times further away than the alternative. How do they do this? We used radio-frequency identification-tagged ants to monitor individual behaviour. Here we show for the first time that switching between nests during the decision process can influence nest choice without requiring direct comparison of nests. Ants finding the poor nest were likely to switch and find the good nest, whereas ants finding the good nest were more likely to stay committed to that nest. When ants switched quickly between the two nests, colonies chose the good nest. Switching by ants that had the opportunity to compare nests had little effect on nest choice. We suggest a new mechanism of collective nest choice: individuals respond to nest quality by the decision either to commit or to seek alternatives. Previously proposed mechanisms, recruitment latency and nest comparison, can be explained as side effects of this simple rule. Colony-level comparison and choice can emerge, without direct comparison by individuals.