The flying buttress construct for posterior spinopelvic fixation: a technical note

Background

School screening for adolescent idiopathic scoliosis (AIS) is discussed. The aim of the present study was to describe the point prevalence of AIS and to evaluate the effectiveness of school screening in 12-year- old children.

Methods

Community nurses and physical therapists in the Southern Health region of Norway including about 12000 school children aged 12 years were invited to participate. All participating community nurses and physical therapists fulfilled an educational course to improve their knowledge about AIS and learn the screening procedure including the Adam Forward Bending Test and measurement of gibbus using a scoliometer.

Results

Sub-regions including 4000 school children participated. The prevalence of idiopathic scoliosis defined as a positive Adam Forward Bending Test, gibbus > 7° and primary major curve on radiographs > 10°, was 0.55%. Five children (0.13%) had a major curve > 20°. Bracing was not indicated in any child; all children were post menarche; four had Risser sign of 4, and one with Risser 1 did not have curve progression > 5° at later follow-up. In one of these 5 children however, the major curve progressed to 45° within 7 months after screening and the girl was operated.

Conclusion

The point prevalence of AIS in 12- year old children is in agreement or slightly lower than previous studies. The screening model employed demonstrates acceptable sensitivity and specificity and low referral rates. Screening at the age of 12 years only was not effective for detecting patients with indication for brace treatment.     

Structural Determinants Underlying Photoprotection in the Photoactive Orange Carotenoid Protein of Cyanobacteria

The photoprotective processes of photosynthetic organisms involve the dissipation of excess absorbed light energy as heat. Photoprotection in cyanobacteria is mechanistically distinct from that in plants; it involves the orange carotenoid protein (OCP), a water-soluble protein containing a single carotenoid. The OCP is a new member of the family of blue light-photoactive proteins; blue-green light triggers the OCP-mediated photoprotective response. Here we report structural and functional characterization of the wild type and two mutant forms of the OCP, from the model organism Synechocystis PCC6803. The structural analysis provides high resolution detail of the carotenoid-protein interactions that underlie the optical properties of the OCP, unique among carotenoid-proteins in binding a single pigment per polypeptide chain. Collectively, these data implicate several key amino acids in the function of the OCP and reveal that the photoconversion and photoprotective responses of the OCP to blue-green light can be decoupled.     

Dynamics of the Establishment of Systemic Potyvirus Infection: Independent yet Cumulative Action of Primary Infection Sites

In the clinic, farm, or field, for many viruses there is a high prevalence of mixed-genotype infections, indicating that multiple virions have initiated infection and that there can be multiple sites of primary infection within the same host. The dynamic process by which multiple primary infection sites interact with each other and the host is poorly understood, undoubtedly due to its high complexity. In this study, we attempted to unravel the basic interactions underlying this process using a plant RNA virus, as removing the inoculated leaf can instantly and rigorously eliminate all primary infection sites. Effective population size in the inoculated leaf and time of removal of the inoculated leaf were varied in experiments, and it was found that both factors positively influenced if the plant became systemically infected and what proportion of cells in the systemic tissue were infected, as measured by flow cytometry. Fitting of probabilistic models of infection to our data demonstrated that a null model in which the action of each focus is independent of the presence of other foci was better supported than a dependent-action model. The cumulative effect of independently acting foci therefore determined when plants became infected and how many individual cells were infected. There was no evidence for interference between primary infection sites, which is surprising given the planar structure of leaves. By showing that a simple null model is supported, we experimentally confirmed—to our knowledge for the first time—the minimal components that dictate interactions of a conspecific virus population establishing systemic infection.     

Effects of potyvirus effective population size in inoculated leaves on viral accumulation and the onset of symptoms

Effective population size (N(e)) is a key parameter for understanding evolutionary processes, but it is generally not considered in epidemiological studies or in studying infections of individual hosts. Whether N(e) has an effect on the onset of symptoms and viral accumulation in Tobacco etch virus (TEV) infection of Nicotiana tabacum plants is considered here. Using mixtures of TEV variants carrying fluorescent markers, the dose dependence of N(e) was confirmed, and the inoculation procedure was found to be the main source of variation in these experiments. Whereas the onset of symptoms was independent of N(e), there was less and more variable accumulation at 6 days postinoculation for small N(e) values (N(e) < 5). The observed variation in accumulation was not heritable, however, suggesting that this variation was not due to the fixation of deleterious mutations in the small founder populations. On the other hand, virus-induced fluorescence and accumulation in the inoculated leaf were strongly N(e) dependent. Systemic accumulation was independent of N(e), although removal of the inoculated leaf led to a small reduction in systemic accumulation for small N(e) values. For whole plants, N(e)-dependent effects on accumulation were no longer observed at 9 days postinoculation. Therefore, the effects of N(e) on accumulation are due mainly to limited expansion in the inoculated leaf and are transient. In this system, N(e)-dependent effects will be strongest at low doses and early in infection. We conclude that N(e) can have implications for epidemiology and infection at the individual host level, beyond determining the rate of mixed-genotype infection.     

Indel-II region deletion sizes in the white spot syndrome virus genome correlate with shrimp disease outbreaks in southern Vietnam

Sequence comparisons of the genomes of white spot syndrome virus (WSSV) strains have identified regions containing variable-length insertions/deletions (i.e. indels). Indel-I and Indel-II, positioned between open reading frames (ORFs) 14/15 and 23/24, respectively, are the largest and the most variable. Here we examined the nature of these 2 indel regions in 313 WSSV-infected Penaeus monodon shrimp collected between 2006 and 2009 from 76 aquaculture ponds in the Mekong Delta region of Vietnam. In the Indel-I region, 2 WSSV genotypes with deletions of either 5950 or 6031 bp in length compared with that of a reference strain from Thailand (WSSV-TH-96-II) were detected. In the Indel-II region, 4 WSSV genotypes with deletions of 8539, 10970, 11049 or 11866 bp in length compared with that of a reference strain from Taiwan (WSSV-TW) were detected, and the 8539 and 10970 bp genotypes predominated. Indel-II variants with longer deletions were found to correlate statistically with WSSV-diseased shrimp originating from more intensive farming systems. Like Indel-I lengths, Indel-II lengths also varied based on the Mekong Delta province from which farmed shrimp were collected.     

Novel ATP competitive MK2 inhibitors with potent biochemical and cell-based activity throughout the series

Optimization of our previously described pyrrolopiperidone series led to the identification of a new benzamide sub-series, which exhibits consistently high potency in biochemical and cell-based assays throughout the series. Strong inhibition of LPS-induced production of the cytokine TNFα is coupled to the regulation of HSP27 phosphorylation, indicating that the observed cellular effects result from the inhibition of MK2. X-ray crystallographic and computational analyses provide a rationale for the high potency of the series.     

Les génotypes responsables de mucoviscidose ou d’absence bilatérale des canaux déférents ABCD

Over the last decade, the genetic basis for CBAVD has been identified by its association with CFTR gene mutations, and CBAVD is now generally considered to be a mild or incomplete form of CF. In this review, the author summarizes the main results of compilation of CFTR gene analysis conducted in French laboratories for 3,923 patients with CF and 800 males with CABVD. The degree of clinical expression can be affected by several variables, including the molecular mechanisms by which the various CFTR mutations impair or disrupt the function of the CFTR chloride channel. Phenotypic expression of CFTR mutational genotypes varies from severe, progressive pulmonary disease with pancreatic insufficiency (CF-PI), to mild pulmonary disease with pancreatic sufficiency (PS) or singleorgan forms of “CFTR-opathies”. In CF, a total of 310 different CFTR mutations accounting for 94% of 7,846 CF alleles have generated almost 500 different genotypes, comprising 2 severe mutations in 88% of cases (CF-PI), one severe mutation in trans to a mild mutation in 11% (CF-PS), and 2 mild mutations in 1% of identified genotypes. In CBAVD, 137 mutations scattered over the whole gene were identified in 60% of 1,600 CBAVD alleles during the study. Among the 150 characterized mutational CFTR genotypes, compound heterozygosity was the rule, and the most frequent CBAVD combinations were ΔF508/5T (35%), ΔF508/other mutation (30%, including ΔF508/R117H-7T: 5,6%), and 5T/other mutation (17%). No combination of two severe mutations was found in CBAVD (0%); by contrast with the CF population, 88% of genotypes identified in CBAVD comprised a severe mutation in trans to a mild mutation, and 12% consisted of 2 mild mutations. A total of 22 genotypes were shared by both CF and CBAVD. The role of the 5T allele as a splicing variant with variable, incomplete disease penetrance in CBAVD is reviewed. Other haplotype backgrounds, such as the TG12 sequence and the M470V polymorphism, may influence CFTR splicing and/or function. This study confirms the high molecular heterogeneity of CFTR mutations in CBAVD and emphasizes the importance of extensive CFTR analysis in these patients. Longterm follow-up studies of CBAVD patients are necessary in order to predict the phenotypic consequences of numerous CFTR mutational genotypes.