Identification of the first Toll-like receptor gene in passerine birds: TLR4 orthologue in zebra finch (Taeniopygia guttata)

Toll-like receptors (TLRs) are the basic components of the vertebrate pathogen recognition system. Despite uniform general structure, remarkable variability in domain composition can be found in individual TLRs among species. Knowledge of interspecific differences is of particular importance to our understanding of selective pressures on TLRs. Currently, most TLRs are characterized only in a limited number of model species, including domestic chicken as a universal avian model. Here, we describe structure and expression pattern of TLR4 in zebra finch, a widely used passerine model species. The tgTlr4 gene consists of three exons (204, 167 and 3033-3043 bp) that are transcribed into messenger RNA with a relatively long 3'-untranslated region (788 bp). Predicted protein is composed of 842 amino acids (aas) forming extracellular domain with nine leucine-rich repeat (LRR) motives flanked at the carboxy-terminal end by leucine-rich repeat carboxy-terminal domain, transmembrane domain and cytoplasmic toll/interleukin-1 receptor domain. The overall structure is similar to other known TLR4 molecules with 32%-49% aa identity to various mammals and 74% to chicken. Although the position of most of the domains in zebra finch TLR4 resembles their position in chicken, there is one extra LRR at the aa position 207-229 in tgTLR4 and one LRR known in chTLR4 is missing. The gene is highly expressed in the bone marrow and in the spleen, intermediately in the gut and low expression was found in the liver and lungs. For the first time in birds, expression of tgTLR4 in peritoneal macrophages was found to be enhanced by the Escherichia coli lipopolysaccharide treatment.

Assessment of a biliary hamartoma with contrast-enhanced sonography using two different contrast agents

A 49 year old male with carcinoma of the esophagus was staged using conventional US of the abdomen. US revealed signs of cirrhosis and a hyporeflexive focal liver lesion of about 5 mm in diameter was found. Low-MI contrast-enhanced ultrasound (CEUS) with SonoVue (Bracco, Milano, Italy) showed an enhancement pattern which was typical for benign liver lesions while high-MI CEUS with Levovist (Schering, Berlin, Germany) revealed a contrast defect in the liver late phase (4:30 min p. i.) which is typical for a malignant lesion. Due to these findings the lesion was evaluated as a potentially malignant lesion and a biopsy was performed. Histology showed a benign biliary hamartoma and incomplete cirrhosis. The findings confirmed that liver-specific contrast agents have the ability to detect very small focal liver lesions not derived from hepatic tissue but may lead to a misinterpretation as a malignant lesion. Nevertheless biliary duct adenomas are benign lesions with almost the same perfusion properties as normal liver parenchyma. Therefore, while using SonoVue, such a misinterpretation of these very common but in most cases very small and not detectable lesions seems unlikely.

COMT polymorphisms in impulsively violent offenders with antisocial personality disorder

OBJECTIVE

The relationship between catechol-O-methyltransferase (COMT) polymorphisms and violent behaviour was tested in highly selected group of non-psychotic violent offenders.

METHODS

We conducted an association study comparing 47 male repeatedly sentenced for impulsive violent attacks diagnosed with Antisocial Personality Disorder (APD) with 43 healthy male controls matched on education. Three COMT polymorphisms were analysed: COMT Val158Met and COMT Ala146Val on exon 4, and untranslated polymorphism on the 6th exon, at the regulatory region of the COMT gene with deletion-insertion character del/C.

RESULTS

Logistic regression analysis revealed that while Val158Met is not associated with violence in APD, another COMT polymorphism - COMT Ala146Val is more frequent among violent offenders with APD (p=0.017).

CONCLUSIONS

To conclude, our findings provide further support that COMT is a modifying gene that plays a role in determining interindividual variability in the proclivity for violent behaviour in subjects without major mental disorder.

[Baseline and contrast-enhanced ultrasound of the liver in tumor patients]

In patients with known malignancy, correct detection and characterization of liver lesions has important therapeutic consequences. Conventional sonography is the most commonly used modality for liver imaging in tumor patients. However, it has a lower sensitivity for the detection of liver metastases compared to contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI). The majority of liver metastases are hypoechoic and well defined in baseline ultrasound (US), while detection of isoechoic or small liver metastases <1 cm is difficult and the differentiation of liver metastases from benign liver lesions and other malignant liver tumors can be impossible with baseline US. The use of microbubble-based ultrasound contrast agents and contrast-specific imaging techniques advanced the accuracy of ultrasound in liver imaging. Levovist and SonoVue are the US contrast agents approved for liver imaging in Europe. Compared to Levovist, SonoVue allows continuous imaging of the liver in real-time over a period of up to 5 minutes. As a result, SonoVue became the preferred contrast agent for liver imaging in the recent years, while Levovist became less important. Important for the detection of liver metastases are the portal venous and late phases in which metastases show a wash-out and can be detected as hypoechoic lesions in homogeneous enhanced liver parenchyma. The detection of hepatic metastases is substantially improved by CEUS compared to conventional B-mode sonography. Several studies showed sensitivity in detecting liver metastases comparable to that of contrast-enhanced CT and MRI. Furthermore, the typical enhancement patterns of the different benign and malignant liver lesions allow reliable characterization and differentiation from liver metastases in the majority of cases. This paper provides information about the advantages and expedient application of contrast-enhanced ultrasound (CEUS) in tumor patients.

Signalling components of the house mouse mate recognition system

Subspecies-specific mate recognition may represent significant barrier to gene flow between diverged genomes potentially leading to speciation. In the house mouse, assortative mating involves the coevolution of several signals and receptors. We compared signalling ability of bedding material, faeces, urine, saliva, salivary androgen binding proteins (ABP) and combinations of urine with saliva and urine with ABP in mate choice in two wild-derived inbred strains (one of Mus musculus musculus and one of Mus musculus domesticus origin). We observed high levels of variation in assortative preferences between the two strains and sexes. The strongest preferences were observed in M. m. musculus-derived individuals in tests where urine was present either alone or as part of a composite signal target. M. m. domesticus-derived mice displayed strain-specific preferences for faeces. Saliva was the least preferred stimulus in both strains and sexes. No effect of two-compound cues was detected. We conclude that there is divergence across both the stimulus and preference parts of the recognition system for both house mouse strains. Of the tested stimuli, those that have the capacity to carry a signal for extended periods under natural conditions (such as urine and faeces) seem to be the most important substances in strain-specific recognition.