Comparison of dual-energy subtraction and electronic bone suppression combined with computer-aided detection on chest radiographs: effect on human observers' performance in nodule detection

The objective of our study was to compare the effect of dual-energy subtraction and bone suppression software alone and in combination with computer-aided detection (CAD) on the performance of human observers in lung nodule detection.

Fluorescent in situ hybridization mapping of the epidermal growth factor receptor gene in donkey

The physical localization of the epidermal growth factor receptor (EGFR) gene was performed on donkey chromosomes. Bacterial artificial chromosome DNA containing the equine EGFR gene was used to map this gene by fluorescent in situ hybridization on donkey metaphase chromosomes. The gene was mapped on donkey 1q21.1 region.

Ethinylestradiol differentially interferes with IGF-I in liver and extrahepatic sites during development of male and female bony fish

Growth and sexual development are closely interlinked in fish; however, no reports exist on potential effects of estrogen on the GH/IGF-I-axis in developing fish. We investigate whether estrogen exposure during early development affects growth and the IGF-I system, both at the systemic and tissue level. Tilapia were fed from 10 to 40 days post fertilization (DPF) with 17alpha-ethinylestradiol (EE(2)). At 50, 75, 90, and 165 DPF, length, weight, sex ratio, serum IGF-I (RIA), pituitary GH mRNA and IGF-I, and estrogen receptor alpha (ERalpha) mRNA in liver, gonads, brain, and gills (real-time PCR) were determined and the results correlated to those of in situ hybridization for IGF-I. Developmental exposure to EE(2) had persistent effects on sex ratio and growth. Serum IGF-I, hepatic IGF-I mRNA, and the number of IGF-I mRNA-containing hepatocytes were significantly decreased at 75 DPF, while liver ERalpha mRNA was significantly induced. At 75 DPF, a transient decline of IGF-I mRNA and a largely reduced number of IGF-I mRNA-containing neurons were observed in the female brain. In both sexes, pituitary GH mRNA was significantly suppressed. A transient downregulation of IGF-I mRNA occurred in ovaries (75 DPF) and testes (90 DPF). In agreement, in situ hybridization revealed less IGF-I mRNA signals in granulosa and germ cells. Our results show for the first time that developmental estrogen treatment impairs GH/IGF-I expression in fish, and that the effects persist. These long-lasting effects both seem to be exerted indirectly via inhibition of pituitary GH and directly by suppression of local IGF-I in organ-specific cells.

Suppression of transforming growth factor beta signalling aborts caerulein induced pancreatitis and eliminates restricted stimulation at high caerulein concentrations

BACKGROUND: Transforming growth factors betas (TGF-betas) are implicated in pancreatic tissue repair but their role in acute pancreatitis is not known. To determine whether endogenous TGF-betas modulate the course of caerulein induced acute pancreatitis, caerulein was administered to wild-type (FVB-/-) and transgenic mice that are heterozygous (FVB+/-) for expression of a dominant negative type II TGF-beta receptor. METHODS: After 7 hourly supramaximal injections of caerulein, the pancreas was evaluated histologically and serum was assayed for amylase and lipase levels. Next, the effects of caerulein on amylase secretion were determined in mouse pancreatic acini, and cholecystokinin (CCK) receptor expression was assessed. RESULTS: The normal mouse pancreas was devoid of inflammatory cells whereas the pancreas from transgenic mice contained lymphocytic infiltrates. Caerulein injection in wild-type mice resulted in 6- and 36-fold increases in serum amylase and lipase levels, respectively, increased serum trypsinogen activation peptide (TAP) levels, gross oedema and a marked inflammatory response in the pancreas that consisted mainly of neutrophils and macrophages. By contrast, FVB+/- mice exhibited minimal alterations in response to caerulein with attenuated neutrophil-macrophage infiltrates. Moreover, acini from FVB+/- mice did not exhibit restricted stimulation at high caerulein concentrations, even though CCK receptor mRNA levels were not decreased. CONCLUSION: Our findings indicate that a functional TGF-beta signalling pathway may be required for caerulein to induce acute pancreatitis and for the CCK receptor to induce acinar cell damage at high ligand concentrations. Our results also support the concept that restricted stimulation at high caerulein concentrations contributes to the ability of caerulein to induce acute pancreatitis.

Very short telomere length by flow fluorescence in situ hybridization identifies patients with dyskeratosis congenita

Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome in which the known susceptibility genes (DKC1, TERC, and TERT) belong to the telomere maintenance pathway; patients with DC have very short telomeres. We used multicolor flow fluorescence in situ hybridization analysis of median telomere length in total blood leukocytes, granulocytes, lymphocytes, and several lymphocyte subsets to confirm the diagnosis of DC, distinguish patients with DC from unaffected family members, identify clinically silent DC carriers, and discriminate between patients with DC and those with other bone marrow failure disorders. We defined "very short" telomeres as below the first percentile measured among 400 healthy control subjects over the entire age range. Diagnostic sensitivity and specificity of very short telomeres for DC were more than 90% for total lymphocytes, CD45RA+/CD20- naive T cells, and CD20+ B cells. Granulocyte and total leukocyte assays were not specific; CD45RA- memory T cells and CD57+ NK/NKT were not sensitive. We observed very short telomeres in a clinically normal family member who subsequently developed DC. We propose adding leukocyte subset flow fluorescence in situ hybridization telomere length measurement to the evaluation of patients and families suspected to have DC, because the correct diagnosis will substantially affect patient management.

Hybridization and Introgression Between Native and Alien Species

Human activities, such intentional and unintentional transplantations, and habitat alterations including the establishment of migration corridors, generate increasing opportunities for formerly allopatric taxa to meet and to hybridize. There is indeed increasing evidence that these introduced plant and animal taxa (including crop plants and domesticated animal taxa) frequently hybridize with native relatives and with other introduced taxa, leading to a growing concern that these hybridizations may compromise the genetic integrity of native taxa to the point of causing extinctions (Abbott 1992; Rhymer and Simberloff 1996; Levin et al. 1996; Ellstrand and Schierenbeck 2000; Vilà et al. 2000). A decade ago, Rhymer and Simberloff (1996) stated in their review on this topic that the known cases are probably just the tip of the iceberg.Using the search term ‘hybridization and introgression’, the Web of Science database yields a total of 1,178 research articles, of which 935 (or 80 %) have been published after 1995 (Fig. 16.1). Indeed, the evidence for natural and man-induced hybridization and introgression appears to have increased exponentially these last few years.

Speciation reversal and biodiversity dynamics with hybridization in changing environments

A considerable fraction of the world's biodiversity is of recent evolutionary origin and has evolved as a by-product of, and is maintained by, divergent adaptation in heterogeneous environments. Conservationists have paid attention to genetic homogenization caused by human-induced translocations (e.g. biological invasions and stocking), and to the importance of environmental heterogeneity for the ecological coexistence of species. However, far less attention has been paid to the consequences of loss of environmental heterogeneity to the genetic coexistence of sympatric species. Our review of empirical observations and our theoretical considerations on the causes and consequences of interspecific hybridization suggest that a loss of environmental heterogeneity causes a loss of biodiversity through increased genetic admixture, effectively reversing speciation. Loss of heterogeneity relaxes divergent selection and removes ecological barriers to gene flow between divergently adapted species, promoting interspecific introgressive hybridization. Since heterogeneity of natural environments is rapidly deteriorating in most biomes, the evolutionary ecology of speciation reversal ought to be fully integrated into conservation biology.

Predictors of optimal viral suppression in patients switched to abacavir, lamivudine, and zidovudine: the Swiss HIV Cohort Study

OBJECTIVE: To investigate predictors of continued HIV RNA viral load suppression in individuals switched to abacavir (ABC), lamivudine (3TC) and zidovudine (ZDV) after successful previous treatment with a protease inhibitor or non-nucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy. DESIGN AND METHODS: An observational cohort study, which included individuals in the Swiss HIV Cohort Study switching to ABC/3TC/ZDV following successful suppression of viral load. The primary endpoint was time to treatment failure defined as the first of the following events: two consecutiveviral load measurements > 400 copies/ml under ABC/3TC/ZDV, one viral load measurement > 400 copies/ml and subsequent discontinuation of ABC/3TC/ZDV within 3 months, AIDS or death. RESULTS: We included 495 individuals; 47 experienced treatment failure in 1459 person-years of follow-up [rate = 3.22 events/100 person-years; 95% confidence interval (95% CI), 2.30-4.14]. Of all failures, 62% occurred in the first year after switching to ABC/3TC/ZDV. In a Cox regression analysis, treatment failure was independently associated with earlier exposure to nucleoside reverse transcriptase inhibitor (NRTI) mono or dual therapy [hazard ratio (HR), 8.02; 95% CI, 4.19-15.35) and low CD4 cell count at the time of the switch (HR, 0.66; 95% CI, 0.51-0.87 by +100 cells/microl up to 500 cells/microl). In patients without earlier exposure to mono or dual therapy, AIDS prior to switch to simplified maintenance therapy was an additional risk factor. CONCLUSIONS: The failure rate was low in patients with suppressed viral load and switch to ABC/3TC/ZDV treatment. Patients with earlier exposure to mono or dual NRTI therapy, low CD4 cell count at time of switch, or AIDS are at increased risk of treatment failure, limiting the use of ABC/3TC/ZDV in these patient groups.

Ligation dependent allele specific quantification (LASQ) of CFTR cDNA on the LightCycler using MLPA hybridization probes

BACKGROUND: As for Cystic Fibrosis (CF) and many other hereditary diseases there is still a lack in understanding the relationship between genetic (e.g. allelic) and phenotypic diversity. Therefore methods which allow fine quantification of allelic proportions of mRNA transcripts are of high importance. METHODS: We used either genomic DNA (gDNA) or total RNA extracted from nasal cells as starting nucleic acid template for our assay. The subjects included in this study were 9 CF patients compound heterozygous for the F508del mutation and each one F508del homozygous and one wild type homozygous respectively. We established a novel ligation based quantification method which allows fine quantification of the allelic proportions of ss and ds CFTR cDNA. To verify reliability and accuracy of this novel assay we compared it with semiquantitative fluorescent PCR (SQF-PCR). RESULTS: We established a novel assay for allele specific quantification of gene expression which combines the benefits of the specificity of the ligation reaction and the accuracy of quantitative real-time PCR. The comparison with SQF-PCR clearly demonstrates that LASQ allows fine quantification of allelic proportions. CONCLUSION: This assay represents an alternative to other fine quantitative methods such as ARMS PCR and Pyrosequencing.

Extracts of Lindera obtusiloba induce antifibrotic effects in hepatic stellate cells via suppression of a TGF-beta-mediated profibrotic gene expression pattern

Liver fibrosis is characterized by high expression of the key profibrogenic cytokine transforming growth factor (TGF)-beta and the natural tissue inhibitor of metalloproteinases (TIMP)-1, leading to substantial accumulation of extracellular matrix. Liver fibrosis originates from various chronic liver diseases, such as chronic viral hepatitis that, to date, cannot be treated sufficiently. Thus, novel therapeutics, for example, those derived from Oriental medicine, have gained growing attention. In Korea, extracts prepared from Lindera obtusiloba are used for centuries for treatment of inflammation, improvement of blood circulation and prevention of liver damage, but experimental evidence of their efficacy is lacking. We studied direct antifibrotic effects in activated hepatic stellate cells (HSCs), the main target cell in the fibrotic liver. L. obtusiloba extract (135 mug/ml) reduced the de novo DNA synthesis of activated rat and human HSCs by about 90%, which was not accompanied by cytotoxicity of HSC, primary hepatocytes and HepG2 cells, pointing to induction of cellular quiescence. As determined by quantitative polymerase chain reaction, simultaneous treatment of HSCs with TGF-beta and L. obtusiloba extract resulted in reduction of TIMP-1 expression to baseline level, disruption of the autocrine loop of TGF-beta autoinduction and increased expression of fibrolytic matrix metalloproteinase (MMP)-3. In addition, L. obtusiloba reduced gelatinolytic activity of HSC by interfering with profibrogenic MMP-2 activity. Since L. obtusiloba extract prevented intracellular oxidative stress experimentally induced by tert-butylhydroperoxide, we concluded that the direct antifibrotic effect of L. obtusiloba extract might be mediated by antioxidant activity. Thus, L. obtusiloba, traditionally used in Oriental medicine, may complement treatment of chronic liver disease.