Sunitinib (SUTENT, SU11248) suppresses tumor growth and induces apoptosis in xenograft models of human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common and third deadliest primary neoplasm. Since HCC is a particularly vascular solid tumor, we determined the antitumor and antiangiogenic activities of sunitinib malate, a potent inhibitor of two receptors involved in angiogenesis - vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR). In the present study, we reported that treatment of HepG2 and SK-Hep-1 cells with sunitinib led to growth inhibition and apoptosis in a dose-dependent fashion. Sunitinib inhibited phosphorylation of VEGFR-2 at Tyr951 and PDGFR-beta at Tyr1021 both in vitro and in vivo. Sunitinib also suppressed tumor growth of five patient-derived xenografts. Sunitinib-induced tumor growth inhibition was associated with increased apoptosis, reduced microvessel density and inhibition of cell proliferation. This study provides a strong rationale for further clinical investigation of sunitinib in patients with hepatocellular carcinoma.

Structural and viscoelastic properties of actin networks formed by espin or pathologically relevant espin mutants

The structural organization of the cytoskeleton determines its viscoelastic response which is crucial for the correct functionality of living cells. Both the mechanical response and microstructure of the cytoskeleton are regulated on a microscopic level by the local activation of different actin binding and/or bundling proteins (ABPs). Misregulations in the expression of these ABPs or mutations in their sequence can entail severe cellular dysfunctions and diseases. Here, we study the structural and viscoelastic properties of reconstituted actin networks cross-linked by the ABP espin and compare the obtained network properties to those of other bundled actin networks. Moreover, we quantify the impact of pathologically relevant espin mutations on the viscoelastic properties of these cytoskeletal networks.

Extraction of Nb and Ta, homolgues of Db, from sulphuric acid solutions with TOA in toluene using SISAK

Extractions of niobium and tantalum as homologues of dubnium (element 105) into tri-octylamine (TOA) in toluene from H2SO4and H2SO4/K2SO4solutions were performed to explore the possibilities of applying the automated on-line liquid–liquid extraction system SISAK to study chemical properties of dubnium in solutions. The results show that the extraction systems TOA/H2SO4and TOA/H2SO4+K2SO4are promising with respect to performing a study of Db with the SISAK system. Suggestions for performing a SISAK Db-experiment are presented. In batch experiments, Pa has also been investigated.

Functional and radiological evaluations of high-energy tibial plateau fractures treated with double-buttress plate fixation

OBJECTIVE

This study was designed to evaluate the functional and radiological outcomes of patients with complex tibial plateau fractures treated with double-buttress plate fixation.

METHODS

Sixty five cases of complex (Schatzker type V and VI) tibial plateau fractures were treated with double-buttress plate fixation in our centre from September 2001 to September 2006 through two separate plate incisions. Fifty four patients were followed up for a period ranging from 12 to 48 months and evaluated for the functional and radiological outcomes by a series of standard questionnaire and measurement.

RESULTS

Due to the good exposure without any extensive soft-tissue dissection of the double-buttress plate fixation, the fractures in all 54 patients were healed and the treatment achieved greater than 90% of satisfactory-to-excellent rates of reduction. The mean time of bone union was 15.4 weeks (range, 12-30 weeks), and the mean time of full weight-bearing was 18.7 weeks (range, 14-26 weeks). At the final follow-up visit, no patients showed knee instability; the mean range of motion was 107.6 degrees (range, 85 degrees -130 degrees ). For all patients, no statistically significant difference in the functional outcomes was observed between their 6-months and final follow-up visits; or in the radiological findings between their immediate postoperative and final follow-up examinations.

CONCLUSION

Double-buttress plate fixation is a feasible treatment option for bilcondylar and complex tibial plateau fractures. Although technically demanding, it offers reliable stability without additional postoperative adjuvant external fixation, and at the same time avoids extensive soft tissue dissection, allowing the early painless range of motion.

Clonal analysis of gastric carcinoma and precancerous lesions and its relation to Ki-67 protein expression

The pathogenesis of intestinal carcinoma is characterized as progressing through multiple steps, which begin with atrophic gastritis followed by intestinal metaplasia, dysplasia and carcinoma. However, the clonal status of gastric precancerous lesions and its association with proliferative kinetics have not been fully understood. In this study, gastric lesions and normal epithelial cells were isolated from formalin-fixed paraffin embedded tissues using a laser capture microdissection (LCM) system, the clonality was analyzed with human androgen receptor gene (HUMARA) polymerase chain reaction (PCR), and the PCR products were examined using Applied Biosystems 3730 DNA Analyzer. The relationship between the clonal status and Ki-67 protein expression was also investigated. Ki-67 was detected by two-step immunohistochemical staining. 5/32 intestinal metaplasia lesions, 10/45 low grade intraepithelial neoplasia, 25/36 high grade intraepithelial neoplasia and 20/20 intestinal gastric carcinoma were of monoclonal origin. Similar to monoclonal inactivation, the expression rate of Ki-67 also increased along the multi-step gastric carcinogenesis. Clonal status was associated with the expression rate of Ki-67 to a certain extent, which may be useful in assessing susceptibility to gastric carcinoma. Key words: gastric carcinoma; precancerous lesion; clonal analysis; Ki-67.

An Outbreak of Head Rot of Cabbage Caused by Rhizoctonia solani AG2-1 in Central China

In July of 2007, an outbreak of head rot of cabbage (Brassica oleracea) occurred on more than 2,500 ha in Changyang County, Hubei Province, China. On average, yields were reduced by approximately 50%. Affected plants were first observed in 2006, and symptoms were considered physiological or nutritional disorders by growers. In 2007, the more extensive summer rains favored an increase in disease severity. Initial symptoms consisted of irregular, brown-to-black lesions on leaves and sometimes a wet decay of the base of outer leaves. Lesions expanded until entire heads were rotted. Rhizoctonia solani was recovered consistently from symptomatic plant tissues. Five isolates were used to evaluate cultural and morphological characteristics of the pathogen. On potato dextrose agar (PDA), all isolates yielded colonies that became brown after 5 days of incubation. The hyphae, 4.9 to 8.0 μm in diameter, branched at right or acute angles near the septa and each cell usually had six to eight nuclei. Dark brown sclerotia, 0.5 to 5 mm in diameter, appeared after 10 days of incubation. Genomic DNA of a representative isolate, CY-1, was extracted, and the rDNA-internal transcribed spacer sequence showed 99.5% identity to R. solani AG2-1 (Accession No. EU513147) in GenBank. Pathogenicity tests were completed in the laboratory by placing 6-mm-diameter mycelial plugs from 3-day-old PDA cultures of the five isolates onto 30 cabbage leaves detached from 5-week-old cabbage plants. The inoculated leaves were incubated at 28°C with 95% relative humidity in a controlled environment chamber. Two days after inoculation, black, wet lesions were observed on all inoculated leaves, while no symptoms were apparent on leaves inoculated with noncolonized PDA plugs. Koch's postulates were fulfilled by reisolating R. solani from diseased leaves. R. solani AG1 (1), AG2-1 (2), and AG4 (4) have been reported as causal agents of diseases of cabbage and related plants, and AG2-1 has been previously isolated from cabbage grown in southwest China (3), but to our knowledge, this is the most severe outbreak reported from China. References: (1) G. S. Abawi and S. B. Martin. Plant Dis. 69:158, 1985. (2) L. Corazza et al. Eur. J. Plant Pathol. 101:341, 1995. (3) H. R. Li and H. H. Zhu. J. Yunnan Agric. Univ. 3:247, 1993. (4) G. H. Yang et al. Plant Pathol. 56:351, 2007.

Investigating lipid-lipid and lipid-protein interactions in model membranes by ToF-SIMS

With the chemical imaging capability of ToF-SIMS, biological molecules are identified and localized in membranes without any chemical labels. We have developed a model membrane system made with supported Langmuir-Blodgett (LB) monolayers. This simplified model can be used with different combinations of molecules to form a membrane, and thus represents a bottom-up approach to study individual lipid-lipid or lipid-protein interactions. We have used ternary mixtures of sphingomyelin (SM), phosphatidylcholine (PC), and cholesterol (CH) in the model membrane to study the mechanism of domain formation and interactions between phospholipids and cholesterol. Domain structures are observed only when the acyl chain saturation is different for SM and PC in the mixture. The saturated lipid, whether it is SM or PC, is found to be localized with cholesterol, while the unsaturated one is excluded from the domain area. More complicated model membranes which involve a functional membrane protein glycophorin are also investigated and different membrane properties are observed compared to the systems without glycophorin.

A chemometric study of chromatograms of tea extracts by correlation optimization warping in conjunction with PCA, support vector machines and random forest data modeling

A reverse phase high performance liquid chromatography (HPLC) separation was established for profiling water soluble compounds in extracts from tea. Whole chromatograms were pre-processed by techniques including baseline correction, binning and normalisation. In addition, peak alignment by correction of retention time shifts was performed using correlation optimization warping (COW) producing a correlation score of 0.96. To extract the chemically relevant information from the data, a variety of chemometric approaches were employed. Principle component analysis (PCA) was used to group the tea samples according to their chromatographic differences. Three principal components (PCs) described 78% of the total variance after peak alignment (64% before) and analysis of the score and loading plots provided insight into the main chemical differences between the samples. Finally, PCA, support vector machines (SVMs) and random forest (RF) machine learning methods were evaluated comparatively on their ability to predict unknown tea samples using models constructed from a predetermined training set. The best predictions of identity were obtained by using RF.

A rete mirabile of the posterior cerebral artery. Embryonic and phylogenetic remnant of choroidal artery origin

SUMMARY

We present the case of a 41-year-old man with a vascular network associated with the left posterior cerebral artery (PCA). Although initially considered to be a brain AVM, further investigation showed no arteriovenous shunting and a rete mirabile of the PCA was diagnosed. A well known but rare occurrence mainly in the anterior circulation, rete mirabile has not previously been described in the PCA.The PCA is a composite vessel, developmentally. Its proximal portion derives from the posterior division of the ICA while its cortical territories are annexed from the anterior choroidal artery adjacent to the lateral geniculate body. We propose that this rete (or network) represents a persistence of the embryonic anastomosis betweenthe AChA and the PCA.

Prevalence of and risk factors for isolated systolic hypertension in the rural adult population of Liaoning Province, China

The prevalence of and associated risk factors for isolated systolic hypertension, as defined by the Joint National Committee (JNC)-6 classification, were investigated in the rural population of Liaoning Province, China. A total of 45,925 people aged 35 years or older were examined in a cross-sectional study. Overall, the prevalence of isolated systolic hypertension was 10.6% (males 10.1%; females 11.2%). The prevalence of isolated systolic hypertension was positively correlated with age, gender, smoking status, alcohol intake, body mass index, salt intake and Mongolian race. This study showed that isolated systolic hypertension was very common in rural Chinese people and that many risk factors are linked with isolated systolic hypertension.

Expression of anion exchanger 2 in human gastric cancer

Anion exchanger 2 (AE2), which mediates exchange of Cl(-)/HCO3(-) across the plasma membrane, is widely expressed in body tissues. It is most abundantly expressed in stomach and is responsible for the uptake of Cl(-) ions that are destined to become HCl molecules.

AIM

To determine whether AE2 expression was altered in gastric tumors.

METHODS

We have studied AE2 expression in normal human gastric tissues (n =16) and in gastric tumors (n = 33) using immunohistochemistry and immunofluorescent labeling.

RESULTS

In normal gastric tissue positive staining was observed in gastric fundus gland, suggesting parietal cell-related expression of AE2, and AE2 expression was localized in the nuclear membrane and even in cell nuclei. For assay of cancerous gastric tissues, specimens of human gastric cancer arising from the region of the fundus (2 cases), the body (14 cases) and the antrum (17 cases) were randomly selected. Immunohistochemical staining has showed that AE2 was down-regulated in all 14 cancerous gastric body specimens, whereas staining for AE2 in cancerous antrum was less intense and had a diffuse profile.

CONCLUSIONS

The data suggest that AE2 might be associated with gastric carcinogenesis and the achlorhydria experienced by gastric cancer patients.

Altered hippocampal circuit function in C3H alpha7 null mutant heterozygous mice

The alpha7 subtype of nicotinic receptor is highly expressed in the hippocampus where it is purported to modulate release of the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). The alpha7 receptor-mediated release of GABA is thought to contribute to hippocampal inhibition (gating) of response to repetitive auditory stimulation. This hypothesis is supported by observations of hippocampal auditory gating deficits in mouse strains with low levels of hippocampal alpha7 receptors compared to strains with high levels of hippocampal alpha7 receptors. The difficulty with comparisons between mouse strains, however, is that different strains have different genetic backgrounds. Thus, the observed interstrain differences in hippocampal auditory gating might result from factors other than interstrain variations in the density of hippocampal alpha7 receptors. To address this issue, hippocampal binding of the alpha7 receptor-selective antagonist alpha-bungarotoxin as well as hippocampal auditory gating characteristics were compared in C3H wild type and C3H alpha7 receptor null mutant heterozygous mice. The C3H alpha7 heterozygous mice exhibited significant reductions in hippocampal alpha7 receptor levels and abnormal hippocampal auditory gating compared to the C3H wild type mice. In addition, a general increase in CA3 pyramidal neuron responsivity was observed in the heterozygous mice compared to the wild type mice. These data suggest that decreasing hippocampal alpha7 receptor density results in a profound alteration in hippocampal circuit function.