Screen for IDH1, IDH2, IDH3, D2HGDH and L2HGDH mutations in glioblastoma.

Isocitrate dehydrogenases (IDHs) catalyse oxidative decarboxylation of isocitrate to (Alpha)-ketoglutarate ((Alpha)-KG). IDH1 functions in the cytosol and peroxisomes, whereas IDH2 and IDH3 are both localized in the mitochondria. Heterozygous somatic mutations in IDH1 occur at codon 132 in 70% of grade II-III gliomas and secondary glioblastomas (GBMs), and in 5% of primary GBMs. Mutations in IDH2 at codon 172 are present in grade II-III gliomas at a low frequency. IDH1 and IDH2 mutations cause both loss of normal enzyme function and gain-of-function, causing reduction of (Alpha)-KG to D-2-hydroxyglutarate (D-2HG) which accumulates. Excess hydroxyglutarate (2HG) can also be caused by germline mutations in D- and L-2-hydroxyglutarate dehydrogenases (D2HGDH and L2HGDH). If loss of IDH function is critical for tumourigenesis, we might expect some tumours to acquire somatic IDH3 mutations. Alternatively, if 2HG accumulation is critical, some tumours might acquire somatic D2HGDH or L2HGDH mutations. We therefore screened 47 glioblastoma samples looking for changes in these genes. Although IDH1 R132H was identified in 12% of samples, no mutations were identified in any of the other genes. This suggests that mutations in IDH3, D2HGDH and L2HGDH do not occur at an appreciable frequency in GBM. One explanation is simply that mono-allelic IDH1 and IDH2 mutations occur more frequently by chance than the bi-allelic mutations expected at IDH3, D2HGDH and L2HGDH. Alternatively, both loss of IDH function and 2HG accumulation might be required for tumourigenesis, and only IDH1 and IDH2 mutations have these dual effects

Mechanisms controlling anaemia in Trypanosoma congolense infected mice.

Trypanosoma congolense are extracellular protozoan parasites of the blood stream of artiodactyls and are one of the main constraints on cattle production in Africa. In cattle, anaemia is the key feature of disease and persists after parasitaemia has declined to low or undetectable levels, but treatment to clear the parasites usually resolves the anaemia. The progress of anaemia after Trypanosoma congolense infection was followed in three mouse strains. Anaemia developed rapidly in all three strains until the peak of the first wave of parasitaemia. This was followed by a second phase, characterized by slower progress to severe anaemia in C57BL/6, by slow recovery in surviving A/J and a rapid recovery in BALB/c. There was no association between parasitaemia and severity of anaemia. Furthermore, functional T lymphocytes are not required for the induction of anaemia, since suppression of T cell activity with Cyclosporin A had neither an effect on the course of infection nor on anaemia. Expression of genes involved in erythropoiesis and iron metabolism was followed in spleen, liver and kidney tissues in the three strains of mice using microarrays. There was no evidence for a response to erythropoietin, consistent with anaemia of chronic disease, which is erythropoietin insensitive. However, the expression of transcription factors and genes involved in erythropoiesis and haemolysis did correlate with the expression of the inflammatory cytokines Il6 and Ifng. The innate immune response appears to be the major contributor to the inflammation associated with anaemia since suppression of T cells with CsA had no observable effect. Several transcription factors regulating haematopoiesis, Tal1, Gata1, Zfpm1 and Klf1 were expressed at consistently lower levels in C57BL/6 mice suggesting that these mice have a lower haematopoietic capacity and therefore less ability to recover from haemolysis induced anaemia after infection

Trypanosoma vivax Infections: Pushing Ahead with Mouse Models for the Study of Nagana. I. Parasitological, Hematological and Pathological Parameters

African trypanosomiasis is a severe parasitic disease that affects both humans and livestock. Several different species may cause animal trypanosomosis and although Trypanosoma vivax (sub-genus Duttonella) is currently responsible for the vast majority of debilitating cases causing great economic hardship in West Africa and South America, little is known about its biology and interaction with its hosts. Relatively speaking, T. vivax has been more than neglected despite an urgent need to develop efficient control strategies. Some pioneering rodent models were developed to circumvent the difficulties of working with livestock, but disappointedly were for the most part discontinued decades ago. To gain more insight into the biology of T. vivax, its interactions with the host and consequently its pathogenesis, we have developed a number of reproducible murine models using a parasite isolate that is infectious for rodents. Firstly, we analyzed the parasitical characteristics of the infection using inbred and outbred mouse strains to compare the impact of host genetic background on the infection and on survival rates. Hematological studies showed that the infection gave rise to severe anemia, and histopathological investigations in various organs showed multifocal inflammatory infiltrates associated with extramedullary hematopoiesis in the liver, and cerebral edema. The models developed are consistent with field observations and pave the way for subsequent in-depth studies into the pathogenesis of T. vivax - trypanosomosis

Trypanosoma vivax Infections: Pushing Ahead with Mouse Models for the Study of Nagana. II. Immunobiological Dysfunctions

Trypanosoma vivax is the main species involved in trypanosomosis, but very little is known about the immunobiology of the infective process caused by this parasite. Recently we undertook to further characterize the main parasitological, haematological and pathological characteristics of mouse models of T. vivax infection and noted severe anemia and thrombocytopenia coincident with rising parasitemia. To gain more insight into the organism's immunobiology, we studied lymphocyte populations in central (bone marrow) and peripherical (spleen and blood) tissues following mouse infection with T. vivax and showed that the immune system apparatus is affected both quantitatively and qualitatively. More precisely, after an initial increase that primarily involves CD4+ T cells and macrophages, the number of splenic B cells decreases in a step-wise manner. Our results show that while infection triggers the activation and proliferation of Hematopoietic Stem Cells, Granulocyte-Monocyte, Common Myeloid and Megacaryocyte Erythrocyte progenitors decrease in number in the course of the infection. An in-depth analysis of B-cell progenitors also indicated that maturation of pro-B into pre-B precursors seems to be compromised. This interferes with the mature B cell dynamics and renewal in the periphery. Altogether, our results show that T. vivax induces profound immunological alterations in myeloid and lymphoid progenitors which may prevent adequate control of T. vivax trypanosomosis

The unique resistance and resilience of the Nigerian West African Dwarf goat to gastrointestinal nematode infections

<p>Abstract</p> <p>Background</p> <p>West African Dwarf (WAD) goats serve an important role in the rural village economy of West Africa, especially among small-holder livestock owners. They have been shown to be trypanotolerant and to resist infections with <it>Haemonchus contortus </it>more effectively than any other known breed of goat.</p> <p>Methods</p> <p>In this paper we review what is known about the origins of this goat breed, explain its economic importance in rural West Africa and review the current status of our knowledge about its ability to resist parasitic infections.</p> <p>Conclusions</p> <p>We suggest that its unique capacity to show both trypanotolerance and resistance to gastrointestinal (GI) nematode infections is immunologically based and genetically endowed, and that knowledge of the underlying genes could be exploited to improve the capacity of more productive wool and milk producing, but GI nematode susceptible, breeds of goats to resist infection, without recourse to anthelmintics. Either conventional breeding allowing introgression of resistance alleles into susceptible breeds, or transgenesis could be exploited for this purpose. Appropriate legal protection of the resistance alleles of WAD goats might provide a much needed source of revenue for the countries in West Africa where the WAD goats exist and where currently living standards among rural populations are among the lowest in the world.</p

A Retrospective Analysis of Primary Tumour Histology and Survival in Breast Cancer Patients Developing Symptomatic Brain Metastases Treated with Whole Brain Radiotherapy (WBRT) at Mount Vernon Cancer Centre (MVCC).

Abstract Background: The purpose of this study was to determine the influence of primary tumour histology on survival following WBRT for brain metastases in patients with breast cancer.Methods: From treatment records we identified 294 patients with brain metastases and a diagnosis of primary breast cancer who were treated with WBRT at MVCC from January 2000 until December 2008. We obtained information from case notes and original pathology reports regarding TNM staging and receptor status: Estrogen (ER), progesterone (PR) and human epidermal growth factor receptor-2 (HER-2). Dates of diagnosis and death were sourced from records at MVCC, the Thames Cancer Registry and GP practices.Results: We obtained receptor status, TNM staging and dates of death for 294 patients; 19 were excluded as date of death could not be verified. The dates of primary diagnosis for the study cohort ranged from 1983 to 2008. The median age at diagnosis was 52 (range 24-81, interquartile range 42-62).Analysis of age at primary diagnosis expressed as &amp;lt; 50 or ≥ 50 demonstrated improved survival in the younger age group (HR 0.64 95% CI 0.50-0.83). Time to brain relapse amongst patients receiving WBRT was not related to initial tumour size (p=0.8) but was related to the number of affected nodes (reduced by 9 months per node, p=0.038) and women with (non-brain) metastatic disease at diagnosis had WBRT on average 2.4 years earlier than those that did not (p=0.004). TNM staging did not affect post WBRT survival. After adjusting for age at diagnosis (&amp;lt;,≥50), post WBRT survival was not affected by age at treatment. Controlling for the influence of age at diagnosis, Cox regression analysis of survival post WBRT demonstrated improved survival for ER positive patients (HR 0.66 95% CI 0.49-0.90). Survival post WBRT was not significantly influenced by HER-2 (HR 0.81 95% CI 0.55-1.19) or PR (HR 0.91 95% C.I. 0.63-1.33) status. Patients who experience late brain relapse (&amp;gt; 4 years post diagnosis) have slightly better survival post WBRT (HR 0.77, p=0.054). ER positive patients in this study developed brain metastases on average 1.8 years later than ER negative patients (95% CI 0.9-2.8).Conclusions: In this cohort ER positive patients who relapse in the brain do so later and live longer following WBRT (figure 1). Our data suggests that HER-2 status has little effect on post WBRT survival. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4110.</jats:p

A retrospective survival analysis of whole brain radiotherapy (WBRT) for brain metastases at Mount Vernon Cancer Centre (MVCC)

2068 Background: The primary purpose of this retrospective study was to determine the survival of patients with brain metastases following WBRT with regards to the influence of tumor type, age &lt; 65 versus ≥ 65 (RPA RTOG prognostic factor) and recency of treatment date. Methods: From treatment records we identified 1,926 patients with brain metastases from solid tumors who were treated with WBRT at MVCC between February 1992 and March 2008. Dates of death were sourced from records at MVCC, the Cancer Registry and GP practices. Results: We obtained dates of death for patients with lung (n=804), breast (n=457), colorectal (n=129), skin (n=119), kidney (n=82), and unknown primary (n=124) cancers. 42 patients were excluded from analysis as their tumor types were unspecified. A heterogeneous group of 169 patients with a variety of other primary tumor types were also excluded from our primary analyses. 22% of the patients died within the first month following WBRT and only 2.4% remained alive at 2 years. Log-rank analysis of age &lt; 65 versus ≥ 65 demonstrated improved survival for the former for the colorectal, lung, and skin tumor types (p = 0.0048, 0.0001, and 0.0456 respectively). This relationship did not reach significance for the breast, unknown primary, and renal cancer groups (p = 0.14, 0.13, and 0.06 respectively). With the exception of colorectal cancer, the analysis of the effect of treatment date on survival did not reveal recent improvements in survival for patients with brain metastases. An improvement in survival was experienced by the colorectal subgroup treated after March 2006 (HR= 0.51 95% CI 0.27- 0.96). Conclusions: Our data validate age as an important prognostic factor for many tumor types with notable exceptions for as yet undetermined reasons. Metastasis to the brain is a late stage feature of colorectal malignancy. The survival of the majority of patients undergoing WBRT for brain metastases is poor and with the possible exception of colorectal cancer, has not improved over the last decade. [Table: see text] [Table: see text] </jats:p