Salivary pathogen and serum antibody to assess the progression of chronic periodontitis: a 24-mo prospective multicenter cohort study

BACKGROUND AND OBJECTIVE

A diagnosis of periodontitis progression is presently limited to clinical parameters such as attachment loss and radiographic imaging. The aim of this multicenter study was to monitor disease progression in patients with chronic periodontitis during a 24-mo follow-up program and to evaluate the amount of bacteria in saliva and corresponding IgG titers in serum for determining the diagnostic usefulness of each in indicating disease progression and stability.

MATERIAL AND METHODS

A total of 163 patients with chronic periodontitis who received trimonthly follow-up care were observed for 24 mo. The clinical parameters and salivary content of Porphyromonas gingivalis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans were assessed using the modified Invader PLUS assay, and the corresponding serum IgG titers were measured using ELISA. The changes through 24 mo were analyzed using cut-off values calculated for each factor. One-way ANOVA or Fisher's exact test was used to perform between-group comparison for the data collected. Diagnostic values were calculated using Fisher's exact test.

RESULTS

Of the 124 individuals who completed the 24-mo monitoring phase, 62 exhibited periodontitis progression, whereas 62 demonstrated stable disease. Seven patients withdrew because of acute periodontal abscess. The ratio of P. gingivalis to total bacteria and the combination of P. gingivalis counts and IgG titers against P. gingivalis were significantly related to the progression of periodontitis. The combination of P. gingivalis ratio and P. gingivalis IgG titers was significantly associated with the progression of periodontitis (p = 0.001, sensitivity = 0.339, specificity = 0.790).

CONCLUSIONS

It is suggested that the combination of P. gingivalis ratio in saliva and serum IgG titers against P. gingivalis may be associated with the progression of periodontitis.

Self-recovery in schizophrenia: Insight from autobiographical narratives of patients

The self or identity is often seriously challenged by the emergence of psychotic symptoms. A first reason for that is most likely due to the traumatic experience caused by the sudden emergence of hallucinations or persecutory ideas that challenge both the representation of oneself and that of the world and others. A second reason is linked to the social consequences of having a mental illness and of being assigned with the label of “mentally ill or disabled person”. A third relates to the patients’ cognitive impairment that alters their ability to take distance from these self-challenging events, to give a meaning to these experiences and to build coherent narratives of their life that integrate a great variety of personal experiences such as turning points or unpleasant events. For these reasons, recovering from a severe mental illness is a process through which the self evolves by integrating the lessons of past personal events, building new representations of oneself and looking to new directions for future projects. Excerpts of patients’ narratives collected in experimental setting will be presented in order to illustrate how indexes of recovery can be measured in self-narratives and how they help identifying the steps of self-recovery that have been identified in qualitative research on patients with schizophrenia .

Lymphomas and immunological tolerance in the rat induced by murine leukemia viruses

Several lines of Friend, Gross, and Rauscher virus-induced rat tumors were able to grow only in Friend, Gross, and Rauscher virus-tolerant rats that had received injections of each of these viruses at birth. When the tumors were transplanted into the virus-tolerant rats that had received injections of the other types of murine leukemia virus (MuLV), they grew initially and then regressed. Tumors did not grow in normal rats. The same is true in the methylcholanthrene-induced tumors that had been infected with MuLVs. It was deduced from these results that the transplantation antigen of tumor cells that were induced by infection with Friend, Gross, and Rauscher viruses may contain an antigen common to all three viruses and also an antigen that is individually specific, and that the host's immunological tolerance (induced by the neonatal injection of either Friend, Gross, or Rauscher virus) may consist of the tolerance common to all three viruses and, also, of the tolerance that is individually specific.

Structural Basis for Action of the External Chaperone for a Propeptide-deficient Serine Protease from Aeromonas sobria

Subtilisin-like proteases are broadly expressed in organisms ranging from bacteria to mammals. During maturation of these enzymes, N-terminal propeptides function as intramolecular chaperones, assisting the folding of their catalytic domains. However, we have identified an exceptional case, the serine protease from Aeromonas sobria (ASP), that lacks a propeptide. Instead, ORF2, a protein encoded just downstream of asp, appears essential for proper ASP folding. The mechanism by which ORF2 functions remains an open question, because it shares no sequence homology with any known intramolecular propeptide or other protein. Here we report the crystal structure of the ORF2-ASP complex and the solution structure of free ORF2. ORF2 consists of three regions: an N-terminal extension, a central body, and a C-terminal tail. Together, the structure of the central body and the C-terminal tail is similar to that of the intramolecular propeptide. The N-terminal extension, which is not seen in other subtilisin-like enzymes, is intrinsically disordered but forms some degree of secondary structure upon binding ASP. We also show that C-terminal (ΔC1 and ΔC5) or N-terminal (ΔN43 and ΔN64) deletion eliminates the ability of ORF2 to function as a chaperone. Characterization of the maturation of ASP with ORF2 showed that folding occurs in the periplasmic space and is followed by translocation into extracellular space and dissociation from ORF2, generating active ASP. Finally, a PSI-BLAST search revealed that operons encoding subtilases and their external chaperones are widely distributed among Gram-negative bacteria, suggesting that ASP and its homologs form a novel family of subtilases having an external chaperone.

Tumour characteristics, treatment patterns and survival of patients aged 80 years or older with colorectal cancer

AIM

This study aimed to clarify tumour characteristics and treatment patterns for patients with colorectal cancer aged 80 years or older and the impact of age on survival using a large-scale cancer registry database.

METHOD

The database was used to identify 40 851 colorectal cancer patients who underwent surgery between 1995 and 2004. Patients were stratified into four age groups (< 50, 50-64, 65-79, ≥ 80 years). Demographics, tumour characteristics, treatment pattern and survival were compared between age groups. Additionally, the impact of lymph node dissection and adjuvant chemotherapy on survival was studied using the propensity score-matching method.

RESULTS

In the over 80 age group, patients were more commonly female, with right colon cancer, multiple primary cancers, history of colorectal cancer, high serum carcinoembryonic antigen values, large tumour, undifferentiated histology, and more frequent pT3/pT4 tumours. In contrast, metastatic disease, central lymph node dissection and adjuvant chemotherapy were less frequent. Overall survival and cancer-specific survival decreased with increasing age for any stage. Multivariate analysis showed age to be an independent predictor of overall survival (hazard ratio 1.45, 95% CI 1.34-1.58, P < 0.001). In the propensity score-matched cohort, overall survival of the patients with central node dissection and having adjuvant chemotherapy was significantly better than for those without. This difference was not statistically significant in patients aged 80 and above.

CONCLUSION

This study showed a significant difference in tumour characteristics and treatment patterns in patients aged 80 and above. Even after adjustment for clinicopathological factors, the difference in survival persisted and age was considered a robust prognostic factor.

A Genome-wide Association Study of Periodontitis in a Japanese Population

Periodontitis is a multifactorial disease in which bacterial, lifestyle, and genetic factors are involved. Although previous genetic association studies identified several susceptibility genes for periodontitis in European populations, there is little information for Asian populations. Here, we conducted a genome-wide association study and a replication study consisting of 2,760 Japanese periodontitis patients and 15,158 Japanese controls. Although single-nucleotide polymorphisms that surpassed a stringent genome-wide significance threshold ( P < 5 × 10−8) were not identified, we found 2 suggestive loci for periodontitis: KCNQ5 on chromosome 6q13 (rs9446777, P = 4.83 × 10−6, odds ratio = 0.82) and GPR141-NME8 at chromosome 7p14.1 (rs2392510, P = 4.17 × 10−6, odds ratio = 0.87). A stratified analysis indicated that the GPR141-NME8 locus had a strong genetic effect on the susceptibility to generalized periodontitis in Japanese individuals with a history of smoking. In conclusion, this study identified 2 suggestive loci for periodontitis in a Japanese population. This study should contribute to a further understanding of genetic factors for enhanced susceptibility to periodontitis.

Real space imaging of spin polarons in Zn-doped SrCu(2)(BO(3))(2)

We report on the real space profile of spin polarons in the quasi-two-dimensional frustrated dimer spin system SrCu(2)(BO(3))(2) doped with 0.16% of Zn. The (11)B nuclear magnetic resonance spectrum exhibits 15 additional boron sites near nonmagnetic Zn impurities. With the help of exact diagonalizations of finite clusters, we have deduced from the boron spectrum, the distribution of local magnetizations at the Cu sites with fine spatial resolution, providing direct evidence for an extended spin polaron. The results are confronted with those of other experiments performed on doped and undoped samples of SrCu(2)(BO(3))(2).

Reproducibility of condylar twist angle measurement using computed tomography and axial radiography of the distal femur

INTRODUCTION

It is essential to understand rotational alignment of the distal femur when performing total knee arthroplasty (TKA). Several rotational landmarks including condylar twist angle (CTA) are used for preoperative planning and during TKA. Axial radiography of the distal femur is used for measuring the CTA, and assessing rotational alignment in TKA. The aim of this study was to investigate the reliability and the reproducibility of the CTA using two different methods and evaluate if CTA differed between varus and valgus knees and between normal and osteoarthritic knees.

MATERIALS AND METHODS

CTA were obtained from 144 knees (77 patients) having total knee or hip arthroplasty using computed tomography (CT) and axial radiography. Subjects were divided into five groups based on femorotibial angle (FTA) and into four groups based on the severity of knee osteoarthritis. The intra-observer and inter-observer reliabilities of these methods and inter-method differences were evaluated.

RESULTS

The mean CTA was 7.02° with axial radiography, and 6.87° with CT images. There were no significant differences among the five FTA groups and among the four osteoarthritis groups. In total, intra-/inter-observer, and inter-method intraclass correlation coefficients were substantial or almost perfect in the scoring system of Landis et al. However, discrepancies ≥ 2° between the two methods were observed in more than 20% of knees.

CONCLUSION

The CTA should be reassessed by more than two observers or two methods for precise preoperative TKA planning in cases where it is difficult to identify the bony landmarks for CTA measurements.

LEVEL OF EVIDENCE

Level III.

Understanding of others' knowledge in French and Japanese children: a comparative study with a disambiguation task on 16-38-month-olds

In order to explain the cultural differences reported in the results of false-belief tasks, we attempted to verify the 'task bias hypothesis' suggested by certain studies (e.g. Tardif et al. (2004). Journal of Child Language, 31, 779-800; Rubio-Fernandez & Geurts (2013). Psychological Science, 24(1), 27-33. doi 10.1177/0956797612447819). At the same time, we aimed to observe the theory of mind (ToM) ability of infants and young children under the age of three in verbal communication. To this end, we propose a new protocol to test young children's ToM ability, with particular attention paid to the linguistic aspect of the task. This original disambiguation task using proper nouns (first names) was tested on a total of 32 children aged between 16 and 38 months, in France and Japan. The results revealed that after the age of 30 months children begin to correctly interpret nouns while simultaneously taking into account their partner's knowledge (50% of the French and 29% of the Japanese children were successful), whereas this remains difficult for younger children (no child under 30 months was successful). The analysis of error types has shown that 'memory bias' was dominant in younger children in particular and 'association bias' was rarely observed across all ages. Given that the results of French and Japanese children did not differ significantly, we assume that this new task design could minimise the influence of cultural difference caused by the characteristics of different languages.