How does the lead arsenate prevent the young codling moth larva from injuring the fruit?

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Some Notes on the Oyster Shell Scale

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Reduction in cytokine production in colorectal cancer patients: association with stage and reversal by resection

The aim of this study was to assess monocyte/macrophage function, as defined by lipopolysaccharide (LPS)-induced production of tumour necrosis factor (TNF)-α, interleukin (IL)-10 and interferon (IFN)-γ by stimulated whole blood cultures in patients with colorectal carcinoma before and after surgical resection. Forty colorectal cancer patients prior to surgery and 31 healthy controls were studied. Heparinized venous blood was taken from colorectal cancer patients prior to surgery and from healthy controls. Serial samples were obtained at least 3–6 weeks post-operatively. Blood was stimulated with LPS for 24 h and supernatants were assayed for TNF-α, IFN-γ and IL-10 by enzyme-linked immunosorbent assay. LPS-induced production of TNF-α and of IFN-γ was reduced in patients with colorectal carcinoma compared to controls (TNF-α, 11 269 pg ml−1{12 598}; IFN-γ, 0.00 pg ml−1{226}; median {IQR}) (TNF-α, 20 576 pg ml−1{11 637}, P< 0.0001; IFN-γ, 1048 {2428}, P = 0.0051, Mann–Whitney U -test). Production in patients after surgery had increased (TNF-α: 17 620 pg ml−1{7986}; IFN-γ: 410 pg ml−1{2696}; mean {s.d.}) and were no longer significantly reduced when compared to controls (TNF-α, P = 0.28; IFN-γ, P = 0.76). Production of TNF-α and IFN-γ prior to surgery were reduced to a greater extent in patients with Dukes' stage C tumours compared to those with Dukes' stage A and B stage. There was no difference in IL-10 production between any group. Monocytes/macrophages from patients with colorectal carcinoma are refractory to LPS stimulation as reflected by reduction in TNF-α and IFN-γ production and this is more pronounced in patients with advanced stage tumours. This suppression is not mediated by IL-10 and disappears following surgical resection of the tumour. This provides evidence for tumour induced suppression of immune function in patients with colorectal cancer and identifies a potential therapeutic avenue. © 2000 Cancer Research Campaig

Learning-by-doing as an approach to teaching social entrepreneurship

Many studies have explored the use of learning-by-doing in higher education, but few have applied this to social entrepreneurship contexts and applications: this paper addresses this gap in the literature. Our programme involved students working with different stakeholders in an interactive learning environment to generate real revenue for social enterprises. Our results show that learning-by-doing enables students to develop their entrepreneurial skills and enhance their knowledge of social businesses. The findings also show that students became more effective at working in teams and in formulating and applying appropriate business strategies for the social enterprises. Overall, the learning-by-doing approach discussed in this paper is capable of developing the entrepreneurial skills of students, but there are challenges that need to be addressed if such an approach is to be effective

Supernatants from lymphocytes stimulated with Bacillus Calmette-Guerin can modify the antigenicity of tumours and stimulate allogeneic T-cell responses

BACKGROUND: Reduced expression of class 1 human leucocyte antigens (HLA1) is often a mechanism by which tumours evade surveillance by the host immune system. This is often associated with an immune function that is unable to mount appropriate responses against disease, which can result in a state that favours carcinogenesis. METHODS: In the current study, we have explored the effects of Bacillus Calmette-Guerin (BCG) on the cytokine output of leucocytes, which is a key determinant in generating antitumour action, and have also assessed the effect of these cytokine cocktails on HLA1 expression in solid tumour cell lines. RESULTS: BCG potently activated a broad range of leucocytes, and also enhanced the production of cytokines that were Th(1)-predominant. Supernatants from BCG-treated leucocytes significantly increased the expression of HLA1 on the surface of cancer cell lines, which correlated with increased cytolytic T-cell activity. We also showed that the increased HLA1 expression was associated with activation of intracellular signalling pathways, which was triggered by the increases in the Th(1)-cytokines interferon-γ and tumour necrosis factor-α, as counteracting their effects negated the enhancement. CONCLUSION: These studies reaffirm the role of BCG as a putative immunotherapy through their cytokine-modifying effects on leucocytes and their capacity to enhance tumour visibility