Dried blood spots are a useful tool for quality assurance of rapid HIV testing in Kigali, Rwanda

A study was conducted in two primary health facilities in Kigali, Rwanda, to determine whether dried blood spots (DBS) used for quality control of HIV testing would give comparable results with serum after being stored for a period of 14 days and 30 days at ambient temperature. DBS and serum specimens were collected from patients undergoing HIV testing. ELISA performed on serum at baseline (gold standard) was compared with DBS results. The study included a total of 491 patients, comprising 92 (19%) males and 399 (81%) females with a median age of 27 years. A total of 148 individuals (30%) were HIV-positive. The average ambient temperature under which DBS specimens were stored at the health facilities was 23 degrees C (range 18-25 degrees C). The kappa statistic at 14 days and 30 days was 0.99 (99.4% agreement) and 0.98 (99.2% agreement), respectively, signifying almost 'perfect agreement (P<0.001)' with the gold standard. In a resource-limited sub-Saharan African country embarking on scaling-up of HIV testing, DBS stored at ambient conditions for up to 1 month were found to be a useful and robust tool to perform quality control of rapid HIV testing at the health centre level.

Endoscopic placement of fibrin sealant as a treatment for a long-standing Boerhaave's fistula

A 64-year-old man suffered a spontaneous rupture of the esophagus (Boerhaave's syndrome) after an episode of severe retching. He underwent attempted primary repair of the esophageal defect, but unfortunately the repair failed with the development of a persistent esophago-bronchial fistula resistant to extended conservative management. Three hundred and nineteen days after the initial rupture, the fistula was successfully treated with endoscopic placement of fibrin glue. We believe this to be the first reported case of fibrin sealant being used in the treatment of a long-standing fistula resulting from Boerhaave's syndrome.

First reported case of esophageal paraganglioma. A review of the literature of gastrointestinal tract paraganglioma including gangliocytic paraganglioma

Paraganglioma and the variant gangliocytic paraganglioma are rare gastrointestinal tumors. We present the first reported case of an esophageal paraganglioma and a review of the literature. From this review it seems that these tumors can occur at any age and usually present with acute or chronic bleeding with or without abdominal pain. The majority of reported cases originated in the foregut, most commonly the second part of the duodenum. Macroscopically the tumor may be pedunculated, sessile or ulcerated and have been described up to 10 cm in size. There are no reported cases of gut paragangliomas shown to be producing clinically significant amounts of catecholamines. The majority of reported tumors have been benign, only 7% malignant at presentation and all with lymph node metastases. One case developed bone metastases 3 years after excision and another recurred locally. There has been no benefit seen from radiotherapy or chemotherapy to date and it is recommended that all of these tumors are widely excised together with a lymph node resection if possible.

The bile acid deoxycholic acid (DCA) at neutral pH activates NF-kappaB and induces IL-8 expression in oesophageal cells in vitro

Barrett's oesophagus patients accumulate chromosomal defects during the histological progression to cancer, one of the most prominent of which is the amplification of the whole of chromosome 4. We aimed to study the role that the transcription factor NF-kappaB, a candidate cancer- promoting gene, present on chromosome 4, plays in Barrett's oesophagus, using OE33 cells as a model. Specifically, we wanted to determine if NF-kappaB was activated by exposure to bile acid (deoxycholic acid) in oesophageal cells. We employed pathway specific cDNA microarrays and real-time PCR, to first identify bile acid induced genes and specifically to investigate the role of NF-kappaB. An NF-kappaB reporter system was used, as well as an inhibitor of NF-kappaB (pyrrolidine dithiocarbamate) to confirm the activation of NF-kappaB by bile. We show that physiological levels of DCA (100-300 microM) were capable of activating NF-kappaB in OE33 cells and inducing NF-kappaB target gene expression (particularly IkappaB and IL-8). Other gene expression abnormalities were also shown to be induced by DCA. Importantly, preliminary experiments showed that NF-kappaB activation by bile occurred at neutral pH, but not at acid pH. Acidic bile did however cause over-expression of the c-myc oncogene, as reported previously. Hence, we present data showing that NF-kappaB may be a key mediator of carcinogenesis in bile exposed Barrett's tissues. In addition, neutral bile acids appear to play a significant part in reflux induced gene expression changes. We postulate that the activation of the survival factor NF-kappaB by bile may be linked to the previous cytogenetic data from our laboratory showing the amplification of NF-kappaB's chromosome (chromosome 4), during Barrett's cancer progression. Hence chromosome 4 amplification may provide a survival mechanism for bile exposed oesophageal tissues via NF-kappaB.

Code Growth, Explicitly Defined Introns, and Alternative Selection Schemes

Previous work on introns and code growth in genetic programming is expanded on and tested experimentally. Explicitly defined introns are introduced to tree-based representations as an aid to measuring and evaluating intron behavior. Although it is shown that introns do create code growth, they are not its only cause. Removing introns merely decreases the growth rate; it does not eliminate it. By systematically negating various forms of intron behavior, a deeper understanding of the causes of code growth is obtained, leading to the development of a system that keeps unnecessary bloat to a minimum. Alternative selection schemes and recombination operators are examined and improvements demonstrated over the standard selection methods in terms of both performance and parsimony.

Code growth, explicitly defined introns, and alternative selection schemes

Previous work on introns and code growth in genetic programming is expanded on and tested experimentally. Explicitly defined introns are introduced to tree-based representations as an aid to measuring and evaluating intron behavior. Although it is shown that introns do create code growth, they are not its only cause. Removing introns merely decreases the growth rate; it does not eliminate it. By systematically negating various forms of intron behavior, a deeper understanding of the causes of code growth is obtained, leading to the development of a system that keeps unnecessary bloat to a minimum. Alternative selection schemes and recombination operators are examined and improvements demonstrated over the standard selection methods in terms of both performance and parsimony.

Social stress and trauma: synthesis and spatial analysis

In the last decade violence has emerged as a public health issue, with concomitant interest in surveillance and prevention. This paper is an extension of earlier work seeking to expand the ecological analysis of violence across jurisdictional boundaries, sharpen the level of resolution of such analysis, and ultimately inform small area policy applications in terms of public health initiatives for violence reduction. The underlying model is drawn from stress theory and rests on a set of social indicators representing stress in the Baltimore area. In the earlier work, a set of 24 variables describing violence and socioeconomic conditions across some 1358 areas was factor analyzed and the resulting scores were mapped and interpreted. The present paper takes the analysis a step further in an attempt to identify groups of observations with common traits in order to assist public health professionals and other relevant decision-makers in the process of trauma surveillance, response, and prevention. Cluster analysis was used to combine most similar observations in terms of the three orthogonal factors, and the resulting cluster affiliations were mapped in geographic space. Although no spatial contiguity constraint was put on the clustering algorithm, many statistical clusters were also found to constitute geographic clusters. This implies that the process identified neighborhoods or parts of neighborhoods with shared traits in terms of the underlying set of stressors. Analysis of this type could be used by policy-makers to classify neighborhoods in terms of their needs for various services in addition to public health interventions, including policing, fire protection, building inspection, social work, and education.