Disruption of cellulose synthesis by 2,6-dichlorobenzonitrile affects the structure of the cytoskeleton and cell wall construction in Arabidopsis

Cellulose is the major component of plant cell walls and is an important source of industrial raw material. Although cellulose biosynthesis is one of the most important biochemical processes in plant biology, the regulatory mechanisms of cellulose synthesis are still unclear. Here, we report that 2,6-dichlorobenzonitrile (DCB), an inhibitor of cellulose synthesis, inhibits Arabidopsis root development in a dose- and time-dependent manner. When treated with DCB, the plant cell wall showed altered cellulose distribution and intensity, as shown by calcofluor white and S4B staining. Moreover, pectin deposition was reduced in the presence of DCB when immunostained with the monoclonal antibody JIM5, which was raised against pectin epitopes. This result was confirmed using Fourier transform infrared (FTIR) analysis. Confocal microscopy revealed that the organisation of the microtubule cytoskeleton was significantly disrupted in the presence of low concentrations of DCB, whereas the actin cytoskeleton only showed changes with the application of high DCB concentrations. In addition, the subcellular dynamics of Golgi bodies labelled with N-ST-YFP and TGN labelled with VHA-a1-GFP were both partially blocked by DCB. Transmission electron microscopy indicated that the cell wall structure was affected by DCB, as were the Golgi bodies. Scanning electron microscopy showed changes in the organisation of cellulose microfibrils. These results suggest that the inhibition of cellulose synthesis by DCB not only induced changes in the chemical composition of the root cell wall and cytoskeleton structure, but also changed the distribution of cellulose microfibrils, implying that cellulose plays an important role in root development in Arabidopsis.

[A study on the relationship between HPV infection and the oncogenesis of primary squamous carcinoma of the lung.]

BACKGROUND

To research the relationship between human papillomavirus (HPV) infection and the oncogenesis of primary squamous carcinoma of the lung.

METHODS

50 formalin-fixed paraffin-embedded tissues of squamous cell carcinoma of the lung , 30 samples of areas of squamous epithelium metaplasia near tumors , and 30 samples of normal bronchial mucosa were detected for the presence of HPV DNA by polymerase chain reaction (PCR) .

RESULTS

In these samples , the positive detection rate of HPV DNA was 26%, 36.7% and 10% respectively. Of the detected HPV DNA , HPV16 was of the highest ratio. The positive rate of HPV6/11 and HPV16 in squamous cell carcinoma and squamous epithelium metaplasia had no significant difference by Chi-Square test ( P > 0. 05) .

CONCLUSIONS

These results suggest that HPV infection might play an important role in the oncogenesis of squamous cell carcinomas of the lung , and squamous epithelium metaplasia of the bronchus could be regarded as a precancer lesion. Compared with biotinylated DNA probes and hybridization technique , PCR has a higher sensitivity.

Comparison of Preincisional and Postincisional Parecoxib Administration on Postoperative Pain Control and Cytokine Response After Total Hip Replacement

Objective:

To investigate whether preincisional parecoxib administration can reduce postoperative pain and modulate the inflammatory cytokine response to a greater extent than preincisional parecoxib administration in total hip replacement patients.

Methods:

Patients were randomized to receive 40 mg parecoxib intravenously either before or after skin incision (preincisional and postincisional groups, respectively). Morphine was administered for postoperative analgesia. Visual analogue pain scale (VAS) scores and morphine consumption were recorded at 1, 6, 18 and 24 h postoperation. Plasma levels of interleukin (IL)-6, IL-8 and tumour necrosis factor-a were measured 30 min before skin incision and 6 h postoperation.

Results:

Compared with the post - incisional group, VAS pain scores at 1 and 6 h postoperation were significantly lower in the preincisional group. Morphine consumption was significantly lower in the preincisional group at 6, 18 and 24 h postoperation. In both groups, IL-6 and IL- 8 levels increased significantly at 6 h postoperation compared with pre - operation, and the preincisional group had significantly lower levels of IL-6 and IL-8 at 6 h postoperation compared with the postincisional group.

Conclusions:

Preincisional parecoxib administration reduced postoperative pain and morphine consumption compared with post - incisional administration, and attenuated IL-6 and IL-8 production 24 h after hip replacement surgery.

Impaired learning and memory performance in a subclinical hypothyroidism rat model induced by hemi-thyroid electrocauterisation

It is well known that clinical hypothyroidism (CH) can induce cognitive deficits, and the decision to start treatment for CH with thyroxine is usually straightforward. However, the relationship of cognition dysfunction with subclinical hypothyroidism (SCH) is inconsistent, and the decision concerning the need to treat SCH is controversial. In the present study, we induced a SCH rat model by hemi-thyroid electrocauterisation; then employed a serial of behavioural tests, including a beam balance, open field task and Morris water maze (MWM), to investigate the behaviour performance of SCH rats; and finally explored the protein expression of phosphorylated extracellular signal-regulated kinase (ERK)1/2 in the hippocampus by western blotting. The results demonstrated that hemi-thyroid electrocauterised rats had an elevated plasma thyrotrophin-stimulating hormone (TSH) level, with normal free thyroxine (fT4) and triiodothyronine (T3) concentrations, which defines SCH in humans. If rat SCH is diagnosed according to measurements of both plasma TSH higher than 97.5 percentile for the sham group and fT4 in the range 2.5-97.5 percentile for the sham group, the success rate of SCH modelling was 66.6%. SCH decreased exploratory behaviour but did not affect motor function in rats, showing a negative correlation of exploratory behaviour with plasma TSH concentration. Moreover, SCH rats displayed an impairment of learning and memory ability in the MWM task, with a longer escape latency in the acquisition phase and a shorter duration in the target quadrant in the test phase compared to that of sham rats. The mechanism for this might be related to the increased plasma TSH concentration, the decreased hippocampal T3 level and the enhanced expression of phosphorylated ERK1/2 in the hippocampus. The results of the present study, together with the results obtained in other studies, suggest that treatment is necessary for SCH.

Identification and expression profiles of grass carp Ctenopharyngodon idella tlr7 in responses to double-stranded RNA and virus infection

The toll-like receptor 7 (tlr7) gene was identified and characterized from grass carp Ctenopharyngodon idella (designated as citlr7), and the messenger (m)RNA expression profiles were examined in vivo and in vitro. The citlr7 genomic sequence consists of 4276 nucleotides (nts), including two exons and one intron. The full length of citlr7 complementary (c)DNA sequence is 3354 nts with the longest open reading frame (ORF) of 3156 nts encoding a peptide of 1051 amino acids. citlr7 mRNA expression was high in spleen, skin and heart, and low in hepatopancreas, muscle, head kidney and trunk kidney in healthy fish. The expression of citlr7 was rapidly and significantly up-regulated at 6 h after grass carp reovirus (GCRV) injection (72·91 fold, P < 0·05), and recovered to the original level at 24 h post-injection in the spleen. The citlr7 transcript was rapidly and significantly down-regulated at the 6 h time point (0·32 fold, P < 0·05) and retrieved the normal level at 72 h post-injection in the hepatopancreas. The citlr7 transcripts were rapidly and significantly inhibited at 2 h post-GCRV infection in the C. idella kidney (CIK) cell line (0·62 fold, P < 0·05), and were rapidly and significantly elevated by the stimulation of the synthetic double-stranded RNA polyriboinosinic-polyribocytidylic acid sodium salt [poly(I:C)] in CIK in a dose and time-dependent manner (P < 0·05). The results imply that citlr7 is involved in the responses to double-stranded RNA and virus infection.

Identification of a novel HLA-A*24:02:55 allele by sequence-based typing

HLA-A*24:02:55 differs from A*24:02:01:01 by a single nucleotide substitution at position 295, in exon 2.

Active-targeted nanotherapy strategies for prostate cancer

Castration-resistant prostate cancer remains incurable and a major cause of mortality worldwide. The absence of effective therapeutic approaches for advanced prostate cancer has led to an intensive search for novel treatments. Emerging nanomedical approaches have shown promising results, in vitro and in vivo, in improving drug distribution and bioavailability, tumor penetration and in limiting toxicity. Nanoscaled carriers bearing finely controlled size and surface properties such as liposomes, dendrimers and nanoparticles have been developed for successful passive and active tumortargeting. Enhanced pharmacokinetics of nanotherapeutics, through improved target delivery and prolonged tissue halflife provides optimal drug delivery that is tumor-specific. Tumor-targeting may be improved through ligand directed delivery systems binding to tumor-specific surface receptors improving cellular uptake through receptor-mediated endocytosis. Recently published data have provided pre-clinical evidence showing the potential of active-targeted nanotherapeutics in prostate cancer therapy; unfortunately, only a few of these therapies have translated into early phase clinical trials development. Hence, progress of active-targeted nanotherapy improving efficiency of site-specific drug delivery is a critical challenge in future clinical treatment of prostate cancer. Exploring specific prostate cell-surface antigens or receptor overexpression may elaborate promising strategies for future therapeutic design. This review presents an overview of some new strategies for prostate cancer active-targeting nanotherapeutics.

The value of multislice spiral CT features of cavitary walls in differentiating between peripheral lung cancer cavities and single pulmonary tuberculous thick-walled cavities

OBJECTIVES

Form discordance of cavity walls (FDCW) and form concordance of cavity walls (FCCW) in multislice spiral CT (MSCT) were investigated to determine their value in differentiating between peripheral lung cancer cavities and single pulmonary tuberculous thick-walled cavities. An assessment of the role of multiplanar reconstruction (MPR) in detecting FDCW and FCCW was also performed.

METHODS

MSCT cross-sectional images of 116 consecutive cases (including 60 cases with available MPR images) with peripheral lung cancer cavities and 118 consecutive cases (including 62 cases with available MPR images) with single pulmonary tuberculous thick-walled cavities (wall thickness >3 mm) were retrospectively analysed. According to the characteristics of cavitary internal and external walls on MSCT, these cavities were divided into two types (FDCW and FCCW). FDCW was further divided into three subtypes (FDCW-I, FDCW-II and FDCW-III); FCCW was further divided into two subtypes (FCCW-I and FCCW-II).

RESULTS

On the cross-sectional and MPR images, the total detection rate of FDCW-I and FDCW-III in peripheral lung cancer cavities was 76.7% (89/116) and 93.3% (56/60), respectively, whereas the total detection rate of FCCW-I and FCCW-II in single pulmonary tuberculous thick-walled cavities was 75.4% (89/118) and 91.9% (57/62), respectively.

CONCLUSIONS

FDCW-I, FDCW-III, FCCW-I and FCCW-II were valuable in differentiating between peripheral lung cancer cavities and single pulmonary tuberculous thick-walled cavities. MPR could improve the detection of FDCW-I and FDCW-III in peripheral lung cancer cavities and FCCW-I and FCCW-II in single pulmonary tuberculous thick-walled cavities.

Development and use of EST-SSR markers for assessing genetic diversity in the brown planthopper (Nilaparvata lugens Stål)

To assess genetic diversity in populations of the brown planthopper (Nilaparvata lugens Stål) (Homoptera: Delphacidae), we have developed and applied microsatellite, or simple sequence repeat (SSR), markers from expressed sequence tags (ESTs). We found that the brown planthopper clusters of ESTs were rich in SSRs with unique frequencies and distributions of SSR motifs. Three hundred and fifty-one EST-SSR markers were developed and yielded clear bands from samples of four brown planthopper populations. High cross-species transferability of these markers was detected in the closely related planthopper N. muiri. The newly developed EST-SSR markers provided sufficient resolution to distinguish within and among biotypes. Analyses based on SSR data revealed host resistance-based genetic differentiation among different brown planthopper populations; the genetic diversity of populations feeding on susceptible rice varieties was lower than that of populations feeding on resistant rice varieties. This is the first large-scale development of brown planthopper SSR markers, which will be useful for future molecular genetics and genomics studies of this serious agricultural pest.

The Valence Electronic Structure of Co3O4: Is It a Charge-Transfer Insulator?

Despite the relevance to a variety of materials applications, the electronic and bonding properties of spinel transition metal oxides are not well established. We report here the slow oxidation of CoO(100) to Co3O4, studied by photoemission (UPS and XPS), low energy electron diffraction (LEED) and high resolution electron energy loss spectroscopy (HREELS) with the aim of elucidating the valence band electronic structure of the Co3O4 spinel. The original Mott insulator picture of the parent CoO substrate has been revised in recent times, after careful analyses and extensive debate, to the more detailed charge-transfer insulator model which includes some admixture of oxygen 2p levels in the 3d-derived valence band. No equivalent band structure analysis has been performed on the spinel oxides, perhaps in part because of the greater complexity of the 56-atom unit cell with two different cation lattice sites and oxidation states. In this study, we determine the valence band structure of the spinel oxide and address the question of whether Co3O4 can be modeled as a charge-transfer insulator in analogy with its closely related rocksalt substrate.