Investigation of 89 candidate gene variants for effects on all-cause mortality following acute coronary syndrome

Background  

Many candidate genes have been reported to be risk factors for acute coronary syndrome (ACS), but their impact on clinical prognosis following ACS is unknown.     

Disturbed erythrocyte calcium homeostasis and adenine nucleotide dysregulation in canine phosphofructokinase deficiency

Muscle-type phosphofructokinase deficiency (PFKD) causes a hemolytic disorder and exertional myopathy in humans and dogs. In humans, PFKD is accompanied by a disturbed calcium homeostasis and associated adenine nucleotide dysregulation, which may potentiate the erythroenzymopathy associated with this inherited disorder. This study shows that canine PFKD also manifests these erythrocyte abnormalities. Compared to normal, healthy red cells, PFK-deficient erythrocytes contain lower concentrations of ATP and higher concentrations of IMP and calcium, the latter as per a calcium indicator dye. Adenosine monophosphate deaminase (AMPD) enriched 5000-fold from canine erythrocytes adsorbs to immobilized calcium–calmodulin and the interaction between these two proteins activates AMPD through a K _mapp effect. This behavior is similar to that of the human erythrocyte enzyme and provides a potential contributing mechanism for accelerated adenine nucleotide turnover in canine PFKD. We propose that adenine nucleotide replacement strategies could benefit the erythroenzymopathy in human and canine PFKD and that the dog model of this disorder is an appropriate vehicle for further elucidating this hypothesis.     

Acute health events in adult patients with genetic disorders: the Marshfield Epidemiologic Study Area.

PURPOSE: We ascertained and reviewed acute health events occurring in 2003 among patients age 18 and greater with well-defined single gene, chromosomal, and selected multifactorial conditions within the Marshfield Epidemiologic Study Area. METHODS: Of 47,077 adult Marshfield Epidemiologic Study Area Central cohort members, 1,831 (3.9%) had been given at least one of 71 ICD-9 codes appropriate for genetic diagnoses of interest. Physician review narrowed this to 591 (1.3%) validated patients for the study. Of the 591, 527 (89.2%) patients registered 6,849 visits, which were manually reviewed to delineate acute, relevant health events in the urgent care and primary care provider setting. RESULTS: A total of 244 acute relevant health events among 126 patients corresponding to 58 different genetic conditions were observed. Acute relevant health events corresponded to 3.4% of the total health events in patients identified with genetic problems. Categories of genetic conditions with the highest frequencies of acute relevant health events included chromosomal and microdeletion syndromes (21.3%), hematologic disorders (11.5%), muscular dystrophies (8.6%), and connective tissue disorders (10.2%). CONCLUSIONS: These data have multiple applications and implications in addressing the natural history, long-term medical needs and financial impact of adult patients with genetic conditions.     

Involvement of Toll-like receptor 4 in the embryogenesis of the rodent filaria <Emphasis Type="Italic">Litomosoides sigmodontis</Emphasis>

To examine the role that lipopolysaccharide (LPS)-like molecules from the filarial intracellular endobacteria Wolbachia might play in the development of filarial infections, a natural infection in the LPS-nonresponsive C3H/HeJ mouse strain was compared to that of the LPS-responsive C3H/HeN mouse strain. C3H/HeN mice have been shown to be susceptible to the rodent filarial nematode Litomosoides sigmodontis, with the development of adult worms including females containing mature microfilariae (first stage larvae) in the uterine tubes. However, free microfilariae are not detected. In this study the worm burden and worm length were not significantly different between the C3H/HeN and C3H/HeJ mice. However, the fertility of worms from CeH/HeJ mice was found to be higher than those from C3H/HeN mice. Significantly, mature microfilariae were found at the site of infection only in C3H/HeJ mice. These results indicate a role for TLR4 signaling in the immune response that inhibits worm embryogenesis and prevents the release of microfilariae or directly kills released microfilariae.     

Innovations in curriculum design: A multi-disciplinary approach to teaching statistics to undergraduate medical students

Background  

Statistics is relevant to students and practitioners in medicine and health sciences and is increasingly taught as part of the medical curriculum. However, it is common for students to dislike and under-perform in statistics. We sought to address these issues by redesigning the way that statistics is taught.     

DicomWorks: Software for Reviewing DICOM Studies and Promoting Low-cost Teleradiology

DicomWorks is freeware software for reading and working on medical images [digital imaging and communication in medicine (DICOM)]. It was jointly developed by two research laboratories, with the feedback of more than 35,000 registered users throughout the world who provided information to guide its development. We detail their occupations (50% radiologists, 20% engineers, 9% medical physicists, 7% cardiologists, 6% neurologists, and 8% others), geographic origins, and main interests in the software. The viewer’s interface is similar to that of a picture archiving and communication system viewing station. It provides basic but efficient tools for opening DICOM images and reviewing and exporting them to teaching files or digital presentations. E-mail, FTP, or DICOM protocols are supported for transmitting images through a local network or the Internet. Thanks to its wide compatibility, a localized (15 languages) and user-friendly interface, and its opened architecture, DicomWorks helps quick development of non proprietary, low-cost image review or teleradiology solutions in developed and emerging countries.     

Interleukin-1beta and tumor necrosis factor-alpha are expressed by different subsets of microglia and macrophages after ischemic stroke in mice

Background  

Interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) are expressed by microglia and infiltrating macrophages following ischemic stroke. Whereas IL-1β is primarily neurotoxic in ischemic stroke, TNF-α may have neurotoxic and/or neuroprotective effects. We investigated whether IL-1β and TNF-α are synthesized by overlapping or segregated populations of cells after ischemic stroke in mice.     

Cholesterol-enriched membrane microdomains are required for inducing host cell cytoskeleton rearrangements in response to attaching-effacing Escherichia coli

The diarrheal pathogens enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain CL56 and enteropathogenic Escherichia coli (EPEC) O127:H6 strain E2348/69 adhere intimately to epithelial cells through attaching-effacing lesions, which are characterized by rearrangements of the host cytoskeleton, intimate adherence, and destruction of microvilli. These cytoskeletal responses require activation of host signal transduction pathways. Lipid rafts are signaling microdomains enriched in sphingolipid and cholesterol in the plasma membrane. The effect of perturbing plasma membrane cholesterol on bacterial intimate adherence was assessed. Infection of both HEp-2 cells and primary skin fibroblasts with strains CL56 and E2348/69 caused characteristic rearrangements of the cytoskeleton at sites of bacterial adhesion. CL56- and E2348/69-induced cytoskeletal rearrangements were inhibited following cholesterol depletion. Addition of exogenous cholesterol to depleted HEp-2 cells restored cholesterol levels and rescued bacterially induced alpha-actinin mobilization. Quantitative bacterial adherence assays showed that EPEC adherence to HEp-2 cells was dramatically reduced following cholesterol depletion, whereas the adherence of EHEC remained high. Cytoskeletal rearrangements on skin fibroblasts obtained from children with Niemann-Pick type C disease were markedly reduced. These findings indicate that host membrane cholesterol contained in lipid rafts is necessary for the cytoskeletal rearrangements following infection with attaching-effacing Escherichia coli. Differences in initial adherence indicate divergent roles for host membrane cholesterol in the pathogenesis of EHEC and EPEC infections.     

Shuttle vectors for <Emphasis Type="Italic">Candida albicans</Emphasis>: control of plasmid copy number and elevated expression of cloned genes

Plasmids containing the inosine monophosphate dehydrogenase gene CaIMH3 from Candida albicans strain ATCC 32354 transform their host to resistance against mycophenolic acid (MPA). The transformants maintain the plasmids at a high copy number (20–40 per cell) and express the CaIMH3 gene at very high levels relative to untransformed controls. The plasmid copy number can be controlled by the concentration of MPA in the media. The transformation procedure is reproducible and the efficiency of transformation is high, up to 15,000 per microgram. Unrearranged plasmids are readily recovered by transforming total DNA from transformants back into Escherichia coli. C. albicans genes cloned into the plasmid are expressed at elevated levels relative to untransformed controls. A derivative vector containing the CaMAL2 promoter and termination sequences expresses the CaERG11 ORF at high levels and confers moderate resistance to fluconazole. These shuttle vectors should facilitate global genomics approaches in C. albicans that have been hampered by its diploid genome.