Complete genome sequence of a tobacco isolate of the tobacco vein banding mosaic virus strain prevailing in China

Tobacco vein banding mosaic virus (TVBMV) is a species of the largest plant virus genus Potyvirus. Its incidence has been increasing in Chinese tobacco-growing area. TVBMV isolates can be clustered into three genetic groups that are corresponding with their geographical origin. We have reported the complete genomic sequence of TVBMV isolate YND with unique NIb/CP cleavage site. Here, we determined and analyzed the complete genomic sequence of isolate HN39, which was collected from tobacco in Henan Province and represented Chinese prevalent strain of TVBMV. HN39 has similar host range with YND, but induce mild vein banding symptom in Nicotiana tabacum cv. Samsun. The genome of TVBMV-HN39 is composed of 9,570 nucleotides, excluding the poly(A) tail. It contains a large ORF of 9,240 nucleotides and encode a polyprotein of 3,079 amino acids. The putative NIa-Pro cleavage site for NIb/CP is Q/G. The identities between the complete genomes of isolates HN39 and YND were 90.0% at nucleotide level and 95.4% at amino acid level. As for other potyviruses, HN39 shared the highest identity with wild tomato mosaic virus (WTMV) at complete genomic level, while different genes shared the highest identities with different potyviruses. This is the second complete genomic sequence of TVBMV reported.

Height growth velocity, islet autoimmunity and type 1 diabetes development: the Diabetes Autoimmunity Study in the Young

AIMS/HYPOTHESIS

Larger childhood body size and rapid growth have been associated with increased type 1 diabetes risk. We analysed height, weight, BMI and velocities of growth in height, weight and BMI, for association with development of islet autoimmunity (IA) and type 1 diabetes.

METHODS

Since 1993, the Diabetes Autoimmunity Study in the Young (DAISY) has followed children at increased type 1 diabetes risk, based on HLA-DR, -DQ genotype or family history, for the development of IA and type 1 diabetes. IA was defined as the presence of autoantibodies to insulin, GAD or protein tyrosine phosphatase islet antigen 2 twice in succession, or autoantibody-positive on one visit and diabetic at the next consecutive visit within 1 year. Type 1 diabetes was diagnosed by a physician. Height and weight were collected starting at age 2 years. Of 1,714 DAISY children <11.5 years of age, 143 developed IA and 21 progressed to type 1 diabetes. We conducted Cox proportional hazards analysis to explore growth velocities and size measures for association with IA and type 1 diabetes development.

RESULTS

Greater height growth velocity was associated with IA development (HR 1.63, 95% CI 1.31-2.05) and type 1 diabetes development (HR 3.34, 95% CI 1.73-6.42) for a 1 SD difference in velocity.

CONCLUSIONS/INTERPRETATION

Our study suggests that greater height growth velocity may be involved in the progression from genetic susceptibility to autoimmunity and then to type 1 diabetes in pre-pubertal children.

The effects of a soluble activin type IIB receptor on obesity and insulin sensitivity

Myostatin, also known as Growth and Differentiation Factor 8, is a secreted protein that inhibits muscle growth. Disruption of myostatin signaling increases muscle mass and decreases glucose, but it is unclear whether these changes are related. We treated mice on chow and high-fat diets with a soluble activin receptor type IIB (ActRIIB.Fc) which is a putative endogenous signaling receptor for myostatin and other ligands of the TGF-β superfamily. After 4 weeks, RAP-031 increased lean and muscle mass, grip strength, and contractile force. RAP-031 enhanced the ability of insulin to suppress glucose production under clamp conditions in high-fat fed mice, but did not significantly change insulin-mediated glucose disposal. The hepatic insulin sensitizing effect of RAP-031 treatment was associated with increased adiponectin levels. RAP-031 treatment for 10 weeks further increased muscle mass and drastically reduced fat content in mice on either chow or high-fat diet. RAP-031 suppressed hepatic glucose production and increased peripheral glucose uptake in chow fed mice. In contrast, RAP-031 suppressed glucose production with no apparent change in glucose disposal in high-fat diet mice. Our findings demonstrate that disruption of ActRIIB signaling is a viable pharmacological approach for treating obesity and diabetes.

Measurement of annexin V uptake and lactadherin labeling for the quantification of apoptosis in adherent Tca8113 and ACC-2 cells

Phosphatidylserine (PS) exposure occurs during the cell death program and fluorescein-labeled lactadherin permits the detection of PS exposure earlier than annexin V in suspended cell lines. Adherent cell lines were studied for this apoptosis-associated phenomenon to determine if PS probing methods are reliable because specific membrane damage may occur during harvesting. Apoptosis was induced in the human tongue squamous carcinoma cell line (Tca8113) and the adenoid cystic carcinoma cell line (ACC-2) by arsenic trioxide. Cells were harvested with a modified procedure and labeled with lactadherin and/or annexin V. PS exposure was localized by confocal microscopy and apoptosis was quantified by flow cytometry. The detachment procedure without trypsinization did not induce cell damage. In competition binding experiments, phospholipid vesicles competed for more than 95 and 90% of lactadherin but only about 75 and 70% of annexin V binding to Tca8113 and ACC-2 cells. These data indicate that PS exposure occurs in three stages during the cell death program and that fluorescein-labeled lactadherin permitted the detection of early PS exposure. A similar pattern of PS exposure has been observed in two malignant cell lines with different adherence, suggesting that this pattern of PS exposure is common in adherent cells. Both lactadherin and annexin V could be used in adherent Tca8113 and ACC-2 cell lines when an appropriate harvesting procedure was used. Lactadherin is more sensitive than annexin V for the detection of PS exposure as the physical structure of PS in these blebs and condensed apoptotic cell surface may be more conducive to binding lactadherin than annexin V.

Diagnostic reproducibility of squamous cell carcinoma (SC) in the era of histology-directed non-small cell lung cancer (NSCLC) chemotherapy: A large prospective study

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Background: Morphology remains the best biomarker for chemotherapy selection in NSCLC. Both bevacizumab and pemetrexed (in first line) are FDA indicated for non-SC histology only, making precise diagnosis key, although data are few on the reproducibility of their categorization. The standard of care, consensus-based World Health Organization diagnostic classification system, Ed. 4 (WHOC) includes 44 diagnostic categories (DC), does not include immunohistochemical (IHC) data, and is not independently validated. In this study, we estimate the reproducibility of SC versus non-SC classification to be only moderately precise. Methods: Pathologists (P) assigned WHOC diagnoses to virtual H&E slides from an incident surgical cohort of 96 primary lung tumors. At a power of 80% we estimated 24 P reviewing 48 slides each would allow for a reproducibility measure in the clinically useful range kappa=0.7, standard error=0.09. In addition to the 44 DC, we also considered the reproducibility of a simplified 10 category system and a chemotherapy-directed 2 class system. Results: 12 self-identified “lung experts” (E) and 12 community (C) P scored slides based on the 44 possible WHOC DC totaling 222 pathologist-pairs and 7130 slides-pairs. P rated confidence in their choices as: high 53%, somewhat 38%, and not confident 8%. 92% of slides were rated as having sufficient quality. Distribution of DC included SC 30% and adenocarcinoma 36%. Conclusions: To our knowledge this is the largest study ever performed of the WHOC, the only one to consider all 44 DC and to distinguish E vs C P. Although this model tests the reproducibility of the WHOC, not clinical lung cancer diagnoses, it shows that reproducible diagnosis of SC based on H&E morphology alone is inadequate. In the era of histology guided therapy, it highlights the need for strict diagnostic criteria and confirmatory IHC stains in the diagnosis of SC.

[Table: see text]

No significant financial relationships to disclose.

Glutamate receptors on myelinated spinal cord axons: I. GluR6 kainate receptors

OBJECTIVE

The deleterious effects of glutamate excitotoxicity are well described for central nervous system gray matter. Although overactivation of glutamate receptors also contributes to axonal injury, the mechanisms are poorly understood. Our goal was to elucidate the mechanisms of kainate receptor-dependent axonal Ca(2+) deregulation.

METHODS

Dorsal column axons were loaded with a Ca(2+) indicator and imaged in vitro using confocal laser-scanning microscopy.

RESULTS

Activation of glutamate receptor 6 (GluR6) kainate receptors promoted a substantial increase in axonal [Ca(2+)]. This Ca(2+) accumulation was due not only to influx from the extracellular space, but a significant component originated from ryanodine-dependent intracellular stores, which, in turn, depended on activation of L-type Ca(2+) channels: ryanodine, nimodipine, or nifedipine blocked the agonist-induced Ca(2+) increase. Also, GluR6 stimulation induced intraaxonal production of nitric oxide (NO), which greatly enhanced the Ca(2+) response: quenching of NO with intraaxonal (but not extracellular) scavengers, or inhibition of neuronal NO synthase with intraaxonal Nomega-nitro-L-arginine methyl ester, blocked the Ca(2+) increase. Loading axons with a peptide that mimics the C-terminal PDZ binding sequence of GluR6, thus interfering with the coupling of GluR6 to downstream effectors, greatly reduced the agonist-induced axonal Ca(2+) increase. Immunohistochemistry showed GluR6/7 clusters on the axolemma colocalized with neuronal NO synthase and Ca(v)1.2.

INTERPRETATION

Myelinated spinal axons express functional GluR6-containing kainate receptors, forming part of novel signaling complexes reminiscent of postsynaptic membranes of glutamatergic synapses. The ability of such axonal "nanocomplexes" to release toxic amounts of Ca(2+) may represent a key mechanism of axonal degeneration in disorders such as multiple sclerosis where abnormal accumulation of glutamate and NO are known to occur.

Mycobacterium bovis Mce4E protein may play a role in modulating cytokine expression profile in alveolar macrophage

SETTING

A large body of research has confirmed that mammalian cell entry proteins (Mce) are related to tuberculosis virulence.

OBJECTIVE

To obtain an insight into the effect of Mce family protein on the pathogenesis of Mycobacterium bovis, we expressed recombinant Mce4E protein in Escherichia coli, and investigated its effect on the expression of tumor necrosis factor alpha (TNF-alpha), inducible NO, interleukin 6 (IL-6) and interleukin 12 (IL-12) in alveolar macrophage by real-time reverse transcriptase polymerase chain reaction (RT-PCR).

RESULTS

Our study demonstrated that after stimulation of alveolar macrophages by Mce4E protein for 48 h, the expression of TNF-alpha was induced, with an enhanced IL-6 mRNA level (P < 0.05) and no changes in IL-12 expression in the macrophages. In addition to the changes in the cytokine expression profile in macrophages, the expression of inducible NO synthase was reduced (P < 0.05). Our MTT [3,(4,5 dimethylthiazol-2yl)-2,5 diphenyl-tetrazolium bromide] analysis of the macrophage also demonstrated that Mce4E protein could inhibit macrophage activity.

CONCLUSION

Our data suggest that Mce4E proteins can induce host inflammation response to M. bovis and may play an important role in host/pathogen interactions.

DOT in rural China: experience from a case study in Shandong Province, China

SETTING

Four counties at varying levels of economic development in Shandong Province were sampled. All offered tuberculosis (TB) directly observed treatment (DOT) treatment at the County TB Dispensary (CTBD).

OBJECTIVE

To empirically document how DOT and home visits were implemented in rural China and to shed light on whether DOT is one of the key elements through which China achieves its high cure rates for TB.

DESIGN

A total of 404 rural smear-positive TB patients registered in the CTBDs were interviewed face-to-face with structured questionnaires. Village doctors and key informants from the CTBDs were also interviewed.

RESULTS

The majority of TB patients in rural areas do not receive DOT from village doctors and rarely get support, such as visits as required, from the CTBDs or township health providers in Shandong, China.

CONCLUSION

The lack of DOT in Shandong does not have a negative effect on TB treatment outcomes. Given that the DOTS strategy is still the core measure of TB control in China, implementation of other programme elements apart from DOT is necessary to ensure a successful TB treatment programme.

Parental social contact in the work place and the risk of childhood acute lymphoblastic leukaemia

To study the possible relation between parental social contact through occupation, a marker for a child's risk of infection, and childhood acute lymphoblastic leukaemia (ALL), the parents of 294 children with ALL aged 0-14.9 years and 376 matched controls were interviewed about their jobs after their child's birth up to the age of 3 years. Job titles were assigned to a level of social contact, and an index of occupational social contact months was created using the level and the job duration. Positive interactions between this index and rural residence associated with an increased risk of childhood ALL and common ALL (c-ALL) were observed (interaction P-value=0.02 for both, using tertiles of contact months; interaction P-value=0.05 and 0.02 for ALL and c-ALL, respectively, using continuous contact months); such findings were not observed when job durations were ignored. Our data suggest that duration of parental occupation may be important when examining the association between parental social contact in the workplace and childhood leukaemia.

A new recombinant vaccinia with targeted deletion of three viral genes: its safety and efficacy as an oncolytic virus

To enhance further the safety and efficacy of oncolytic vaccinia virus, we have developed a new virus with targeted deletions of three viral genes encoding thymidine kinase and antiapoptotic/host range proteins SPI-1 and SPI-2 (vSPT). Infection of human and murine tumor cell lines yielded nearly equivalent or a log lower virus recovery in comparison to parental viruses. Viral infection activated multiple caspases in cancer cells but not in normal cells, suggesting infected cells may die via different pathways. In tumor-bearing mice, vSPT recovery from MC38 tumor was slightly reduced in comparison to two parental viruses. However, no virus was recovered from the brains and livers of mice injected with vSPT in contrast to control viruses. vSPT demonstrated significantly lower pathogenicity in nude mice. Systemic delivery of vSPT showed significant tumor inhibition in subcutaneous MC38 tumor, human ovarian A2780 and murine ovarian MOSEC carcinomatosis models; however, the tumor inhibition by vSPT was reduced compared with parental viruses. These results demonstrated that although deletion of these three viral genes further enhanced tumor selectivity, it also weakened the oncolytic potency. This study illustrates the complexity of creating a tumor-selective oncolytic virus by deleting multiple viral genes involved in multiple cellular pathways.

Chromosomal aneusomy in sputum predicts for lung cancer in nested case-control study

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Background: Lung cancer usually is disseminated at diagnosis and prognosis is poor for most patients. Heavy smokers are known to be at high risk factor for lung cancer and are target population for lung cancer prevention. Sputum has long been considered a potential source of material for biomarker based early detection but no tests have been validated. Methods: Chromosome aneusomy was sought in sputum of 114 cases and 110 controls from the Colorado Sputum Screening Cohort Study, which includes heavy smokers with airflow obstruction matched on age, gender, and date of sample collection. Subject characteristics were as follows: mean age 67 (± 8 years), 75% males, 36% current smokers, mean pack-year 71.2 (± 33.5). The FISH probe LAVysion (Vysis/Abbott) was used, including the DNA targets EGFR, MYCC, 5p15 and CEP6. Results: The multi-target set showed the highest sensitivity (0.78) and specificity (0.95) rates in specimens collected within 12 months of lung cancer diagnosis. The individual probes EGFR, MYCC, 5p15 and CEP6 showed, respectively, decreasing sensitivity rates (0.78, 0.67, 0.62, and 0.29) and increasing specificity rates (0.84, 0.91. 0.86, and 0.95). Combinations of two specific probes (AND) or of any of two probes (OR) have not favorably impacted these coefficients. Proportion of abnormal sputum specimens was higher in squamous cell carcinoma than in adenocarcinoma or small cell carcinoma, both considering the set of specimens collected 12 months prior to disease diagnosis (92%, 75%, 60%) and all specimens (80%, 58%, 44%). Conclusions: Chromosomal aneusomy in sputum was demonstrated in a nested case-control cohort to be a promising marker for prediction of lung cancer risk in heavy smokers with airflow obstruction. Evaluation of four DNA targets was more effective than any single marker or combination of markers, and the test had high sensitivity in patients with squamous cell carcinoma.

[Table: see text]

Schistosoma japonicum triose-phosphate isomerase plasmid DNA vaccine protects pigs against challenge infection

The protective efficacy of a Schistosoma japonicum, Chinese strain, triose-phosphate isomerase (TPI) plasmid DNA vaccine was examined in naïve pigs. Pigs were vaccinated with the TPI DNA-plasmid alone, or in conjunction with IL-12 as pcDNA3.1-P35, pcDNA3.1-P40 plasmids via intramuscular injection. Control pigs were immunized with equivalent amounts of pcDNA3.1. Pigs were immunized 3 times at 21-day intervals and challenged 30 days after the final boost. Forty-five days post-challenge, pigs were sacrificed and perfused to compare adult worm burdens, female worm burdens, liver egg burdens and granuloma size. We found that pigs vaccinated with SjCTPI DNA alone had adult worm burdens reduced by 48.3% and that a further decrease in adult worm burdens was not seen in the group vaccinated with SjCTPI DNA in conjunction with IL-12 (46.2% reduction). The SjCTPI DNA vaccines had a more pronounced effect on reducing female worm burdens i.e. 53.6% SjCTPI alone and 59.6% for SjCTPI+IL-12. Vaccination with SjCTPI-DNA reduced liver eggs by 49.4% and this response was significantly enhanced by the addition of IL-12 (65.8% reduction in liver eggs). In addition to the dramatic protective effects seen in vaccinated pigs, we also noted that granuloma size was reduced by 42% in both groups. Thus, vaccination of pigs and other large animals in China with SjCTPI DNA vaccine will likely reduce transmission by reducing adult worm burdens and worm egg output and simultaneously reduce hepatic egg-associated pathology.

Electrochemically deposited Pd islands on an organic surface: the presence of Coulomb blockade in STM I(V) curves at room temperature

Palladium islands with a thickness of a few monolayers were deposited on top of a self-assembled monolayer (SAM) fabricated from 4-mercaptopyridine. In the I(V) curves obtained using the scanning tunneling microscope (STM) clearly the signature of Coulomb blockade is observed, explicitly demonstrating that these islands are coupled to the underlying gold substrate only via a tunneling barrier; this spectroscopic feature also allows to distinguish the palladium islands from similar morphological features present on the gold substrate prior to palladium deposition.

Hydrogen induced metallicity on the ZnO(1010) surface

Exposure of the mixed-terminated surface to atomic hydrogen at room temperature is found to lead to drastic changes of the electrical properties. The insulator surface is found to become metallic. By employing several experimental techniques (electron energy loss spectroscopy, He-atom scattering, and scanning tunneling microscopy) together with ab initio electronic structure calculations we demonstrate that a low-temperature (1 x 1) phase with two H atoms in the unit cell transforms upon heating to another (1 x 1) phase with only one H atom per unit cell. The odd number of electrons added to the surface per unit cell gives rise to partially filled surface states and thus a metallization of the surface.

NMDA receptors mediate calcium accumulation in myelin during chemical ischaemia

Central nervous system myelin is a specialized structure produced by oligodendrocytes that ensheaths axons, allowing rapid and efficient saltatory conduction of action potentials. Many disorders promote damage to and eventual loss of the myelin sheath, which often results in significant neurological morbidity. However, little is known about the fundamental mechanisms that initiate myelin damage, with the assumption being that its fate follows that of the parent oligodendrocyte. Here we show that NMDA (N-methyl-d-aspartate) glutamate receptors mediate Ca2+ accumulation in central myelin in response to chemical ischaemia in vitro. Using two-photon microscopy, we imaged fluorescence of the Ca2+ indicator X-rhod-1 loaded into oligodendrocytes and the cytoplasmic compartment of the myelin sheath in adult rat optic nerves. The AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid)/kainate receptor antagonist NBQX completely blocked the ischaemic Ca2+ increase in oligodendroglial cell bodies, but only modestly reduced the Ca2+ increase in myelin. In contrast, the Ca2+ increase in myelin was abolished by broad-spectrum NMDA receptor antagonists (MK-801, 7-chlorokynurenic acid, d-AP5), but not by more selective blockers of NR2A and NR2B subunit-containing receptors (NVP-AAM077 and ifenprodil). In vitro ischaemia causes ultrastructural damage to both axon cylinders and myelin. NMDA receptor antagonism greatly reduced the damage to myelin. NR1, NR2 and NR3 subunits were detected in myelin by immunohistochemistry and immunoprecipitation, indicating that all necessary subunits are present for the formation of functional NMDA receptors. Our data show that the mature myelin sheath can respond independently to injurious stimuli. Given that axons are known to release glutamate, our finding that the Ca2+ increase was mediated in large part by activation of myelinic NMDA receptors suggests a new mechanism of axo-myelinic signalling. Such a mechanism may represent a potentially important therapeutic target in disorders in which demyelination is a prominent feature, such as multiple sclerosis, neurotrauma, infections (for example, HIV encephalomyelopathy) and aspects of ischaemic brain injury.