Superparamagnetic iron oxides and low molecular weight gadolinium chelates are synergistic for direct visualization of advanced liver fibrosis

PURPOSE: To compare the contrast-to-noise ratio (CNR) of advanced liver fibrosis on nonenhanced (NE), gadolinium enhanced (Gd), superparamagnetic iron oxides enhanced (SPIO), and combined contrast-enhanced (CCE) spoiled gradient echoes (SGEs). MATERIALS AND METHODS: This retrospective study assessed 83 consecutive patients with cirrhosis and 10 consecutive patients without fibrosis. All patients had NE, Gd, SPIO, and CCE images at 1.5 T. A total of six breathhold SGE sequences with varying imaging parameters were assessed. MR images were evaluated qualitatively and, in 15 cirrhotics who underwent liver transplantation, compared to gross pathology. CNR of fibrosis to background liver was compared across sequences and contrast enhancement types. RESULTS: In cirrhotic patients, CCE images on all sequences showed fibrosis as a meshwork of high-signal 1-mm to 3-mm thick reticulations surrounding 2-mm to 5-mm low-signal regenerative nodules. Fibrosis was less visible on Gd and SPIO images and was barely visible on NE images. CNR was significantly higher for CCE than for NE, Gd, or SPIO images in eight of nine comparisons (P < 0.0001-0.05). The liver had a homogeneous appearance in subjects without fibrosis. CONCLUSION: CCE imaging depicts advanced liver fibrosis with higher CNR than NE, Gd, or SPIO SGEs.     

The anti-mycobacterial activity of Lantana camara a plant traditionally used to treat symptoms of tuberculosis in South-western Uganda

Introduction

Tuberculosis continues to be a devastating public health problem. Many communities in Uganda use medicinal plants to treat various infections, including respiratory tract infections. There are claims that some can treat tuberculosis. Verifying some of these claims could lead to discovery of lead compounds for development of a TB drug.

Methods

Chloroform and methanol extracts of L. camara collected from South-western Uganda were screened against three strains of Mycobacterium tuberculosis using the agar-well diffusion method. H37Rv, the rifampicin-resistant TMC-331 and a non-resistant wild strain (28-25271). The MIC and MBC were determined using the Agar dilution method on Middle brook 7H11.

Results

The methanol extract showed the highest activity against all the three strains used, with zones of inhibition of 18.0–22.5 mm and MIC values of 20 µg/ml for H37Rv and 15 µg/ml for both TMC-331 and wild stain. The values for rifampicin were 1.0 µg/ml for both H37Rv and wild strain but rifampicin hardly showed any activity on TMC-331. The MBC value for the methanol extract of L. camara was 30µg/ml for the H37Rv, and 20µg/ml for both the TMC-331 and wild strains of M. tuberculosis. The MBC for rifampicin was 2.0µg/ml for both H37Rv and the wild strain.

Conclusion

We conclude that L. camara contains principles active against M. tuberculosis, which merit further research.Key words: Anti-mycobacterial, In vitro activity, Medicinal plant, Lantana camara, Mycobacterium tuberculosis, rifampicin     

Feminization and Alteration of <Emphasis Type="Italic">Drosophila</Emphasis> Taste Neurons Induce Reciprocal Effects on Male Avoidance Behavior

Taste perception allows most animals to find edible food, potential mates, and avoid ingesting toxic molecules. Intriguingly, a small group of Drosophila taste neurones (expressing Gr66a-Gal4) involved in the perception of bitter substances is also used to detect 7-tricosene (7-T), a male cuticular pheromone. Male flies tend to be inhibited by 7-T whereas females are stimulated by this pheromone. To better understand their role on male courtship, Gr66a-Gal4 neurons were genetically feminized or altered with various transgenes, and the response of transgenic males was measured toward live targets carrying various amounts of 7-T, or of bitter molecules (caffeine, quinine and berberine). Surprisingly, tester males with feminized taste neurons showed an increased dose-dependent avoidance toward targets with high level of any of these substances, compared to other tester males. Conversely, males with altered neurons showed no, or very little avoidance. Moreover, the surgical ablation of the sensory appendages carrying these taste neurons differently affected the behavioral response of the various tester males. The fact that this manipulation did not affect the courtship toward control females nor the locomotor activity of tester males suggests that Gr66a-Gal4 neurons are involved in the sex-specific perception of molecules inducing male avoidance behavior. Edited by Yong-Kyu Kim.     

Radioresistant cells expressing TLR5 control the respiratory epithelium's innate immune responses to flagellin

Bacterial products (such as endotoxins and flagellin) trigger innate immune responses through TLRs. Flagellin‐induced signalling involves TLR5 and MyD88 and, according to some reports, TLR4. Whereas epithelial and dendritic cells are stimulated by flagellin in vitro, the cell contribution to the in vivo response is still unclear. Here, we studied the respective roles of radioresistant and radiosensitive cells in flagellin‐induced airway inflammation in mice. We found that i.n. delivery of flagellin elicits a transient change in respiratory function and an acute, pro‐inflammatory response in the lungs, characterized by TLR5‐ and MyD88‐dependent chemokine secretion and neutrophil recruitment. In contrast, TLR4, CD14 and TRIF were not essential for flagellin‐mediated responses, indicating that TLR4 does not cooperate with TLR5 in the lungs. Respiratory function, chemokine secretion and airway infiltration by neutrophils were dependent on radioresistant, TLR5‐expressing cells. Furthermore, lung haematopoietic cells also responded to flagellin by activating TNF‐α production. We suggest that the radioresistant lung epithelial cells are essential for initiating early, TLR5‐dependent signalling in response to flagellin and thus triggering the lung's innate immune responses.