Loss of cell adhesion molecule CHL1 improves homeostatic adaptation and survival in hypoxic stress

Close homologue of L1 (CHL1) is a transmembrane cell adhesion molecule that is critical for brain development and for the maintenance of neural circuits in adults. Recent studies revealed that CHL1 has diverse roles and is involved in the regulation of recovery after spinal cord injury. CHL1 expression was downregulated in the cerebral cortex, hypothalamus, and brain stem after the induction of acute hypoxia (AH). In the current study, we sought to address the role of CHL1 in regulating homeostasis responses to hypoxia using CHL1-knockout (CHL1^−/−) mice. We found that, compared with wild-type littermates, CHL1^−/− mice showed a dramatically lower mortality rate and an augmented ventilatory response after they were subjected to AH. Immunofluorescence staining revealed that CHL1 was expressed in the carotid body (CB), the key oxygen sensor in rodents, and CHL1 expression level in the CB as assayed by western blot was decreased after hypoxic exposure. The number of glomus cells and the expression of tyrosine hydroxylase (a marker for glomus cells) in the CB of CHL1^−/− mice appeared to be increased compared with CHL1^+/+ mice. In addition, in the ex vivo CB preparation, hypoxia induced a significantly greater afferent nerve discharge in CHL1^−/− mice compared with CHL1^+/+ mice. Furthermore, the arterial blood pressure and plasma catecholamine levels of CHL1^−/− mice were also significantly higher than those of CHL1^+/+ mice. Our findings first demonstrate that CHL1 is a novel intrinsic factor that is involved in CB function and in the ventilatory response to AH.

The effects of music on brain functional networks: a network analysis

The human brain can dynamically adapt to the changing surroundings. To explore this issue, we adopted graph theoretical tools to examine changes in electroencephalography (EEG) functional networks while listening to music. Three different excerpts of Chinese Guqin music were played to 16 non-musician subjects. For the main frequency intervals, synchronizations between all pair-wise combinations of EEG electrodes were evaluated with phase lag index (PLI). Then, weighted connectivity networks were created and their organizations were characterized in terms of an average clustering coefficient and characteristic path length. We found an enhanced synchronization level in the alpha2 band during music listening. Music perception showed a decrease of both normalized clustering coefficient and path length in the alpha2 band. Moreover, differences in network measures were not observed between musical excerpts. These experimental results demonstrate an increase of functional connectivity as well as a more random network structure in the alpha2 band during music perception. The present study offers support for the effects of music on human brain functional networks with a trend toward a more efficient but less economical architecture.

Mechanical loss in multiferroic materials at high frequencies: friction and the evolution of ferroelastic microstructures

Energy absorption in multiferroic materials stems typically from strain relaxation which can be strong even when no extrinsic defects exist in the material. Computer simulations of a simple two-dimensional model on a generic, proper ferroelastic material identify the dissipative mechanisms associated with the dynamical motion as: a) advance and retraction of needle-shaped twin domains and, b) movement of kinks inside twin boundaries. Both movements involve friction losses.

Serum biomarkers analyzed by LC-MS/MS as predictors for short outcome of non-small cell lung cancer patients treated with chemoradiotherapy

PURPOSE

To find potential serum biomakers that can predict clinical outcome upon treatment in non-small cell lung cancer (NSCLC) by analyzing differential proteins in serum with different sensitivity of chemoradiotherapy (CRT).

MATERIALS AND METHODS

Sera were collected from 37 NSCLC patients before they were treated with concurrent cisplatin-based CRT. According to the outcome of CRT, the patients were divided into sensitive group and resistant one. The proteins in sera were separated by two-dimensional gel electrophoresis after the high abundance proteins were removed from sera. The significantly differentially expressed proteins between two groups were analyzed by liquid chromatography and tendem mass spectrometry (LC-MS/MS). Then, an additional 50 serum samples were used for ELISA analysis to validate the identified proteins that we got in the experiment.

RESULTS

Proteins in sera of each group were successfully separated on 2D gels. There were significant discrepancies in serum protein expression between NSCLC patients with different CRT sensitivity. Among eight differently expressed proteins, six proteins were successfully identified with five of which higher expressed and one lower expressed in resistant group. The increased Alpha-1-antitrypsin (α1-AT) level in resistant group comparing to sensitive one were validated by ELISA analysis (p<0.05).

CONCLUSIONS

Proteomic approach may serve as a useful method in detecting the potential biomarkers for predicting the outcome of treatment in NSCLC patients. NSCLC patients with high α1-AT level in serum before CRT may have a worse treatment outcome.

Research on sequence variations analysis of HPV-16 type in Southwestern China

OBJECTIVE

This study was designed to analyze sequence variations in E6, E7, and L1 of human papillomavirus type 16 (HPV-16) to identify novel HPV-6 variants and correlate them with the progression of cervical cancer.

MATERIALS AND METHODS

Cervical biopsies from 12 HPV-16 positive cervical neoplasia cases were analyzed by polymerase chain reaction (PCR) for E6,E7, and L1 gene. The products of PCR were ligated into pGEM-T vector and used to transform e. coli DH5a. Finally, the sequence of the insert was determined by an automated DNA sequencer.

RESULTS

Compared with the European-Germanyl31 (EG131), 20 mutations were detected, of which eight mutations were detected from all the four biopsies: 131(G-A)(Gly-Arg), 178 (T-G)(Asp-Glu),350 (G-T)(Val-Leu), 647 (A-G)(Asn-Asp),846 (T-C) (synonymous mutation), L1 966th (C-T)(synonymous mutation),L1 1302 (C-T)(synonymous mutation) and L1 1434th (A-G) (synonymous mutation).

CONCLUSIONS

Compared with other HPV-16 reference sequences, nucleotide sequencing analysis of the HPV-16, E6,E7, and L1 gene from cervical carcinoma biopses in Southwestern China consistently shows point mutations, including synonymous mutation and nonsynonymous mutation. Above all, the results may have implications for future researches of viral persistence, transmission, oncogenic potential, developing diagnostic probe, and designing vaccine or biological preparation for a particular population.

Effects of feeding corn naturally contaminated with aflatoxin B1 and B2 on hepatic functions of broilers

The purpose of this study was to evaluate the effects of feeding corn naturally contaminated with aflatoxin B(1) (AFB(1)) and aflatoxin B(2) (AFB(2)) on serum biochemical parameters, hepatic antioxidant enzyme activities, and pathological lesions of broilers. In total, 1,200 Cobb male broilers were randomly allocated into 5 treatments, with 8 replicates per treatment and 30 birds per replicate, in a 42-d experiment. The dietary treatments were as follows: control, 25, 50, 75, and 100% contaminated corn groups. Results showed that serum aspartate aminotransferase activity in the 75 and 100% contaminated groups were higher than that in the control group on d 21 (P < 0.05). Decreased content of hepatic total protein and increased activities of hepatic glutathione reductase and glutathione-S-transferase were observed as the percentage of contaminated corn increased (P < 0.05). The activity of superoxide dismutase and the content of hepatic malondialdehyde increased when the broilers were fed with more than 50% contaminated corn (P < 0.05). A reduction in glutathione peroxidase level was observed in the AFB(1)- and AFB(2)-contaminated groups on d 21 (P < 0.05). The average pathological lesion scores and apoptosis rate of liver cells increased as the concentration of dietary AFB(1) and AFB(2) increased. Ultrastructural changes were found in the livers of broilers fed 100% contaminated corn. In conclusion, diets containing AFB(1) and AFB(2) could induce pathological lesions in the livers, slightly change the serum biochemical parameters, and damage the hepatic antioxidant functions when the inclusion of AFB(1)- and AFB(2)-contaminated corn reached or exceeded 50%.

High junction and twin boundary densities in driven dynamical systems

A novel mechanism for the generation of device materials with very high domain boundary densities is described: we shear the sample in a computer experiment and achieve higher twin densities than in rapid quench. These domain patterns are very stable. Elastically soft materials (image with 6.4$ \times $10(5) atoms) has greater twin densities than hard materials, even for nano-crystals.

Isolation and characterization of microsatellite markers in Chinese herb of Dendrobium loddigesii

As an invaluable herb, Dendrobium loddigesii is widely used in Chinese medicinal field. In order to develop a convenient and efficient identification method and investigate the genetic diversity and structure of this species, twelve microsatellite loci were isolated from two microsatellite-enriched libraries. Twenty-six individuals from Baise population were analysed. The observed and expected heterozygosities ranged from 0.174 to 0.617 and from 0.182 to 0.608, respectively. These microsatellite loci characterized from D. loddigesii will contribute to research on the individual authentication, population structure, genetic diversity and conservation of this species and its similar species.

Human papillomavirus infections in women with clinical gynaecological diseases in southwest China

The aim of this study was to determine the prevalence of human papillomavirus (HPV) infections in women with different gynaecological diseases (GDs) and ages in southwest China. With the assay of reverse dot blot, a total of 5544 cervical samples, including 1008 normal and 4536 abnormal specimens from women with GDs, were assayed for HPV detection. For the normal group, 20.2% (204/1008) tested positive for HPV, of which 40.2% (82/204) were high-risk (HR-HPV) genotypes. In the 4536 abnormal samples, 1569 women (34.6%) tested positive for HPV: 73.5% (1153/1569) had a single infection, 17.7% (277/1569) dual infection and 8.8% (138/1569) multiple HPV infection. Of 1569 HPV-positive specimens, 58.7% (921/1569) were infected with only HR-HPV genotypes. Significant differences in HPV infections were found among women of different ages (P < 0.01), number of pregnancies (P < 0.01), GDs (P < 0.01) and age at first sex (P < 0.01). In the present study, we found a high prevalence of HPV infection in women with GDs in southwest China. In addition to HPV types 16 and 18, a significant proportion of other HR-HPV genotypes were detected in this population.