Anti-acrolein treatment improves behavioral outcome and alleviates myelin damage in experimental autoimmune encephalomyelitis mouse

Oxidative stress is considered a major contributor in the pathology of multiple sclerosis (MS). Acrolein, a highly reactive aldehyde byproduct of lipid peroxidation, is thought to perpetuate oxidative stress. In this study, we aimed to determine the role of acrolein in an animal model of MS, experimental autoimmune encephalomyelitis (EAE) mice. We have demonstrated a significant elevation of acrolein protein adduct levels in EAE mouse spinal cord. Hydralazine, a known acrolein scavenger, significantly improved behavioral outcomes and lessened myelin damage in spinal cord. We postulate that acrolein is an important pathological factor and likely a novel therapeutic target in MS.

Regulation of dental enamel shape and hardness

Epithelial-mesenchymal interactions guide tooth development through its early stages and establish the morphology of the dentin surface upon which enamel will be deposited. Starting with the onset of amelogenesis beneath the future cusp tips, the shape of the enamel layer covering the crown is determined by five growth parameters: the (1) appositional growth rate, (2) duration of appositional growth (at the cusp tip), (3) ameloblast extension rate, (4) duration of ameloblast extension, and (5) spreading rate of appositional termination. Appositional growth occurs at a mineralization front along the ameloblast distal membrane in which amorphous calcium phosphate (ACP) ribbons form and lengthen. The ACP ribbons convert into hydroxyapatite crystallites as the ribbons elongate. Appositional growth involves a secretory cycle that is reflected in a series of incremental lines. A potentially important function of enamel proteins is to ensure alignment of successive mineral increments on the tips of enamel ribbons deposited in the previous cycle, causing the crystallites to lengthen with each cycle. Enamel hardens in a maturation process that involves mineral deposition onto the sides of existing crystallites until they interlock with adjacent crystallites. Neutralization of acidity generated by hydroxyapatite formation is a key part of the mechanism. Here we review the growth parameters that determine the shape of the enamel crown as well as the mechanisms of enamel appositional growth and maturation.

Chondrogenic differentiation of mesenchymal stem cells induced by collagen-based hydrogel: an in vivo study

Chondrogenic differentiation of mesenchymal stem cells (MSCs) relies on inductive media of chondrogenic environment. With proper design, a cellular microenvironment mimicking chondrogenic environment might be created to induce chondrogenesis of MSCs. In this study, bone marrow mesenchymal cells (BMSCs) were encapsulated in collagen-based hydrogel, and then enclosed in diffusion-chambers which allow the body fluid to permeate and preclude the host cells to invade. Then, the chamber with the hydrogel-BMSCs composite was implanted in the back of rabbits subcutaneously. The specimens in the chamber were harvested for histological, immunohistochemical, and RT-PCR analyses after 8 weeks. The results showed that cells with the characteristic of chondrocytes were homogenously distributed and the extracellular matrix (ECM) of cartilage has been secreted, indicating the chondrogenic differentiation of BMSCs. As control, nothing was obtained with only BMSCs. Moreover, the expression of collagen type II, indicator of cartilage ECM, was less in tissues with collagen-alginate-hydrogel (CAH) than that with collagen-hydrogel (CH). The results showed that both CH and CAH may induce the chondrogenesis and the induction is materials dependent. From in vitro experiments, TGF-beta is a necessary signal molecule for chondrogenesis, and it was suggested that the material may take in vivo growth factors to trigger chondrogenesis. From the studies, the chondrogenic induction of the hydrogel may be ascribed to that the hydrogel may provide a suitable environment and aggregate the signal molecule for chondrogenesis in vivo. The results would lend valuable reference in clinical for selection of appropriate scaffold for cartilage repair.

Risk of progression to hypertension in a rural Chinese women population with prehypertension and normal blood pressure

BACKGROUND

To determine the incidence of hypertension and its risk factors among rural Chinese women with prehypertension and normotension.

METHODS

A population-based sample of 12,060 rural Chinese women aged > or = 35 years and free from hypertension at baseline were followed from 2004-2006 to 2008. Incident hypertension was defined as systolic blood pressure (SBP) > or = 140 mm Hg, diastolic blood pressure (DBP) > or = 90 mm Hg, or current use of antihypertensive medication.

RESULTS

Over a median follow-up of 28 months (range, 14-47 months), 23.4% of women developed hypertension. The age-adjusted incidence rate was higher in prehypertension than in normotension (11.2/100 person-years vs. 7.9/100 person-years, P < 0.05). Among women with prehypertension, independent predictors of incident hypertension were baseline age, Mongolian ethnicity, low physical activity, baseline body mass index (BMI), baseline salt intake and family history of hypertension. Among women with normal blood pressure (BP), independent predictors were baseline age, low physical activity, baseline BMI and baseline salt intake. The awareness, treatment, and control rates for newly developed hypertension were 33.2, 23.0, and 2.1%, respectively.

CONCLUSIONS

These data indicate that the incidence of hypertension is high among rural Chinese women and it is associated with many risk factors, and the data also suggest that most newly developed hypertension cases are not treated. This high incidence of hypertension may be related to rapid social changes in our country and may apply to other areas of the developing world. These results call for urgent improvements in hypertension prevention, detection and treatment.

Successful Recanalization of a Chronic In-stent Occlusion at the Vertebral Artery Ostium. A Case Report

SUMMARY

In-stent restenosis or occlusion has been frequently reported as a complication after angioplasty and stenting in vertebral arteries. Reopening chronic in-stent occlusion in cervical arteries with endovascular techniques has not been reported. Here we describe a case with stent implantation in the origin of right vertebral artery. The stent was occluded one year after the procedure. The patient demonstrated concurrent ischemic symptoms which were relieved after the in-stent occlusion being recanalized successfully with re-angioplasty.

Cardioprotection of exogenous erythropoietin in mice with ligature-induced aortic stenosis: effects on maladaptive cardiac hypertrophy

Pre-operative treatment with recombinant human erythropoietin may improve aortic stenosis patients' condition, including anemia and/or cardiac dysfunction, for subjecting to aortic valve replacement. In this study, we tested this hypothesis in a mouse model of aortic stenosis. Adult male mice were subjected to either aortic stenosis created by aortic ligature or sham operation. Aortic stenosis for 4 weeks caused cardiac hypertrophy, pulmonary congestion and left ventricular dysfunction. It was associated with increased levels of tumor necrosis factor-alpha in serum and myocardium, and reduced levels of interleukin-10 in myocardium but not in serum. Myocyte apoptosis rate, level of cleaved caspase 3, activity of nuclear factor-kappaB and expression of p38-MAPK pathway were also elevated. Erythropoietin treatment increased hematocrit but did not prevent the development of cardiac hypertrophy. It, however, reduced the apoptosis, prevented the increases in tumor necrosis factor-alpha, nuclear factor-kappaB activation and phosphorylation of p38, and attenuated the increases in lung weight, the decreases in LVEF and LVFS, and the increases in LVDd and LVDs. In conclusion recombinant human erythropoietin has cardioprotective effects in maladaptive cardiac hypertrophy by inhibiting nuclear factor-kappaB activation, phosphorylation of p38-MAPK pathway, and production of tumor necrosis factor-alpha, together leading to a reduced apoptosis.

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.