Estimating prevalence of distant metastatic breast cancer: a means of filling a data gap

PURPOSE: To develop and validate a method for estimating numbers of people with distant cancer metastases, for evidence-based service planning. METHODS: Estimates were made employing an illness-death model with distant metastatic cancer as the illness state- and site-specific mortality as an outcome, using MIAMOD software. To demonstrate the method, we estimated numbers of females alive in Australia following detection of distant metastatic breast cancer during 1980-2004, using data on patient survival from an Australian population-based cancer registry. We validated these estimates by comparing them with direct prevalence counts. RESULTS: Relative survival at 10 years following detection of distant metastases was low (5-20 %), with better survival experienced by: (1) females where distant metastatic disease was detected at initial diagnosis rather than subsequently (e.g., at recurrence); (2) those diagnosed in more recent calendar years; and (3) younger age groups. For Australian females aged less than 85 years, the modeled cumulative risk of detection of distant metastatic breast cancer (either at initial diagnosis or subsequently) declined over time, but numbers of cases with this history rose from 71 per 100,000 in 1980 to 84 per 100,000 in 2004. The model indicated that there were approximately 3-4 prevalent distant metastatic breast cancer cases for every breast cancer death. Comparison of estimates with direct prevalence counts showed a reasonable level of agreement. CONCLUSIONS: The method is straightforward to apply and we recommend its use for breast and other cancers when registry data are insufficient for direct prevalence counts. This will provide estimates of numbers of people who would need ongoing medical surveillance and care following detection of distant metastase

Spontaneous intra-peritoneal bleeding secondary to warfarin, presenting as an acute appendicitis: a case report and review of literature

BACKGROUND: Warfarin is a coumarin anti-coagulant, used widely for the therapeutic and prophylactic anticoagulation. Although, it is considered as a life saving medicine, it is associated with the significant adverse effects including intra-abdominal bleeding, which have been very well documented in literature. However, the presentation of warfarin induced intra-peritoneal bleeding as an acute appendicitis has not been reported in English literature. We report this rare, spontaneous intra-peritoneal bleeding secondary to warfarin therapy, mimicking the signs and symptoms of an acute appendicitis for the first time in English literature. CASE PRESENTATION: A 41 year-old female patient who was on warfarin for prophylaxis following the previous episode of pulmonary embolism, presented to the Casualty with the typical symptoms of an acute appendicitis. During operative intervention, we found it to be the spontaneous intra-peritoneal bleeding secondary to warfarin. The patient recovered well following the operation. CONCLUSION: We recommend the use of the radiological investigations in all the cases of acute abdomen who are on warfarin even if the INR is within the therapeutic range

High-speed shaking of frozen blood clots for extraction of human and malaria parasite DNA

<p>Abstract</p> <p>Background</p> <p>Frozen blood clots remaining after serum collection is an often disregarded source of host and pathogen DNA due to troublesome handling and suboptimal outcome.</p> <p>Methods</p> <p>High-speed shaking of clot samples in a cell disruptor manufactured for homogenization of tissue and faecal specimens was evaluated for processing frozen blood clots for DNA extraction. The method was compared to two commercial clot protocols based on a chemical kit and centrifugation through a plastic sieve, followed by the same DNA extraction protocol. Blood clots with different levels of parasitaemia (1-1,000 p/μl) were prepared from parasite cultures to assess sensitivity of PCR detection. In addition, clots retrieved from serum samples collected within two epidemiological studies in Kenya (n = 630) were processed by high speed shaking and analysed by PCR for detection of malaria parasites and the human α-thalassaemia gene.</p> <p>Results</p> <p>High speed shaking succeeded in fully dispersing the clots and the method generated the highest DNA yield. The level of PCR detection of <it>P. falciparum </it>parasites and the human thalassaemia gene was the same as samples optimally collected with an anticoagulant. The commercial clot protocol and centrifugation through a sieve failed to fully dissolve the clots and resulted in lower sensitivity of PCR detection.</p> <p>Conclusions</p> <p>High speed shaking was a simple and efficacious method for homogenizing frozen blood clots before DNA purification and resulted in PCR templates of high quality both from humans and malaria parasites. This novel method enables genetic studies from stored blood clots.</p

Multi-parallel qPCR provides increased sensitivity and diagnostic breadth for gastrointestinal parasites of humans: field-based inferences on the impact of mass deworming

BACKGROUND: Although chronic morbidity in humans from soil transmitted helminth (STH) infections can be reduced by anthelmintic treatment, inconsistent diagnostic tools make it difficult to reliably measure the impact of deworming programs and often miss light helminth infections. METHODS: Cryopreserved stool samples from 796 people (aged 2-81 years) in four villages in Bungoma County, western Kenya, were assessed using multi-parallel qPCR for 8 parasites and compared to point-of-contact assessments of the same stools by the 2-stool 2-slide Kato-Katz (KK) method. All subjects were treated with albendazole and all Ascaris lumbricoides expelled post-treatment were collected. Three months later, samples from 633 of these people were re-assessed by both qPCR and KK, re-treated with albendazole and the expelled worms collected. RESULTS: Baseline prevalence by qPCR (n = 796) was 17 % for A. lumbricoides, 18 % for Necator americanus, 41 % for Giardia lamblia and 15% for Entamoeba histolytica. The prevalence was <1% for Trichuris trichiura, Ancylostoma duodenale, Strongyloides stercoralis and Cryptosporidium parvum. The sensitivity of qPCR was 98% for A. lumbricoides and N. americanus, whereas KK sensitivity was 70% and 32%, respectively. Furthermore, qPCR detected infections with T. trichiura and S. stercoralis that were missed by KK, and infections with G. lamblia and E. histolytica that cannot be detected by KK. Infection intensities measured by qPCR and by KK were correlated for A. lumbricoides (r = 0.83, p < 0.0001) and N. americanus (r = 0.55, p < 0.0001). The number of A. lumbricoides worms expelled was correlated (p < 0.0001) with both the KK (r = 0.63) and qPCR intensity measurements (r = 0.60). CONCLUSIONS: KK may be an inadequate tool for stool-based surveillance in areas where hookworm or Strongyloides are common or where intensity of helminth infection is low after repeated rounds of chemotherapy. Because deworming programs need to distinguish between populations where parasitic infection is controlled and those where further treatment is required, multi-parallel qPCR (or similar high throughput molecular diagnostics) may provide new and important diagnostic information

Climate stories: Why do climate scientists and sceptical voices participate in the climate debate?

Public perceptions of the climate debate predominantly frame the key actors as climate scientists versus sceptical voices; however, it is unclear why climate scientists and sceptical voices choose to participate in this antagonistic and polarised public battle. A narrative interview approach is used to better understand the underlying rationales behind 22 climate scientists’ and sceptical voices’ engagement in the climate debate, potential commonalities, as well as each actor’s ability to be critically self-reflexive. Several overlapping rationales are identified including a sense of duty to publicly engage, agreement that complete certainty about the complex assemblage of climate change is unattainable and that political factors are central to the climate debate. We argue that a focus on potential overlaps in perceptions and rationales as well as the ability to be critically self-reflexive may encourage constructive discussion among actors previously engaged in purposefully antagonistic exchange on climate change

Acute WNT signalling activation perturbs differentiation within the adult stomach and rapidly leads to tumour formation

A role for WNT signalling in gastric carcinogenesis has been suggested due to two major observations. First, patients with germline mutations in adenomatous polyposis coli (APC) are susceptible to stomach polyps and second, in gastric cancer, WNT activation confers a poor prognosis. However, the functional significance of deregulated WNT signalling in gastric homoeostasis and cancer is still unclear. In this study we have addressed this by investigating the immediate effects of WNT signalling activation within the stomach epithelium. We have specifically activated the WNT signalling pathway within the mouse adult gastric epithelium via deletion of either glycogen synthase kinase 3 (GSK3) or APC or via expression of a constitutively active β-catenin protein. WNT pathway deregulation dramatically affects stomach homoeostasis at very short latencies. In the corpus, there is rapid loss of parietal cells with fundic gland polyp (FGP) formation and adenomatous change, which are similar to those observed in familial adenomatous polyposis. In the antrum, adenomas occur from 4 days post-WNT activation. Taken together, these data show a pivotal role for WNT signalling in gastric homoeostasis, FGP formation and adenomagenesis. Loss of the parietal cell population and corresponding FGP formation, an early event in gastric carcinogenesis, as well as antral adenoma formation are immediate effects of nuclear β-catenin translocation and WNT target gene expression. Furthermore, our inducible murine model will permit a better understanding of the molecular changes required to drive tumourigenesis in the stomach

First serological evidence of West Nile virus in human rural populations of Gabon

To investigate West Nile virus (WNV) circulation in rural populations in Gabon, we undertook a large serological survey focusing on human rural populations, using two different ELISA assays. A sample was considered positive when it reacted in both tests. A total of 2320 villagers from 115 villages were interviewed and sampled. Surprisingly, the WNV-specific IgG prevalence was high overall (27.2%) and varied according to the ecosystem: 23.7% in forested regions, 21.8% in savanna, and 64.9% in the lakes region. The WNV-specific IgG prevalence rate was 30% in males and 24.6% in females, and increased with age. Although serological cross-reactions between flaviviruses are likely and may be frequent, these findings strongly suggest that WNV is widespread in Gabon. The difference in WNV prevalence among ecosystems suggests preferential circulation in the lakes region. The linear increase with age suggests continuous exposure of Gabonese populations to WNV. Further investigations are needed to determine the WNV cycle and transmission patterns in Gabon

Determining the neurotransmitter concentration profile at active synapses

Establishing the temporal and concentration profiles of neurotransmitters during synaptic release is an essential step towards understanding the basic properties of inter-neuronal communication in the central nervous system. A variety of ingenious attempts has been made to gain insights into this process, but the general inaccessibility of central synapses, intrinsic limitations of the techniques used, and natural variety of different synaptic environments have hindered a comprehensive description of this fundamental phenomenon. Here, we describe a number of experimental and theoretical findings that has been instrumental for advancing our knowledge of various features of neurotransmitter release, as well as newly developed tools that could overcome some limits of traditional pharmacological approaches and bring new impetus to the description of the complex mechanisms of synaptic transmission