Screening of known disease genes in congenital scoliosis

Background

Congenital scoliosis (CS) is defined as a lateral curvature of the spine due to the vertebral malformations and has an incidence of 0.5–1/1,000 births. We previously examined TBX6 in Japanese CS patients and revealed that approximately 10% of CS was caused by TBX6 mutations. However, the genetic cause of remaining CS is unknown.

Methods

We recruited 78 CS patients without TBX6 mutations and major comorbidities, and investigated the genes previously reported to be associated with CS and congenital vertebral malformations by whole‐exome sequencing.

Results

We identified the compound heterozygous missense variants in LFNG in one patient. No likely disease‐causing variants were identified in other patients, however. LFNG encodes a GlcNAc‐transferase. The LFNG variants showed loss of their enzyme function.

Conclusions

A LFNG mutation is reported in a case of spondylocostal dysostosis (SCD), a skeletal dysplasia with severe malformations of vertebra and rib. The CS patient with LFNG mutations had multiple vertebral malformations including hemivertebrae, butterfly vertebrae, and block vertebrae, and rib malformations. LFNG mutations may cause a spectrum of phenotypes including CS and SCD. The current list of known disease genes could explain only a small fraction of genetic cause of CS.

Accuracy of powered surgical instruments compared with manual instruments for pedicle screw insertion: Evaluation using o-arm-based navigation in scoliosis surgery

BACKGROUND

Though powered surgical instruments for pedicle screw insertion combined with navigation have been developed to reduce time taken for spine surgery, clinical evidence demonstrating the safety and effectiveness of powered surgical instruments is limited. The goals of the present study were to compare the accuracy of powered instruments and manual instruments using O-arm-based navigation in surgery for scoliosis.

METHODS

We retrospectively identified 60 consecutive patients with adolescent idiopathic scoliosis who underwent posterior corrective surgery using O-arm based navigation, collected from Jun 2013 to Feb 2015. Overall, 393 screws were tapped and inserted in 30 patients using manual instruments (group M) and 547 screws were tapped and inserted in 30 patients using powered instruments (group P). Postoperative computed tomography was used to assess screw accuracy using the established Neo classification (Grade 0, no perforation; Grade 1, perforation <2 mm, Grade 2: perforation ≥2 and <4 mm, Grade 3: perforation ≥4 mm). The time to position one screw, including registration, was calculated.

RESULTS

In group M, 331 (84%) of the 393 pedicle screw placements were categorized as Grade 0, 49 (13%) were Grade 1, 13 (3.3%) were Grade 2, and 0 were Grade 3. In group P, 459 (84%) of the 547 pedicle screw placements were categorized as Grade 0, 75 (14%) were Grade 1, 13 (2.4%) were Grade 2, and 0 were Grade 3. We found no significant difference in the prevalence of Grade 2-3 perforations between groups. The time to insert one pedicle screw was 5.4 ± 1.4 min in group M, but significantly decreased to 3.4 ± 1.2 min in group P.

CONCLUSIONS

Our results demonstrate that powered instruments using O-arm navigation insert pedicle screws as accurately as conventional manual instruments using O-arm navigation. The use of powered instruments requires less time in O-arm surgery for scoliosis.

Characterization of a novel thogotovirus isolated from Amblyomma testudinarium ticks in Ehime, Japan: A significant phylogenetic relationship to Bourbon virus

The genus Thogotovirus, as represented by Thogoto virus and Dhori virus, comprises a group of arthropod-borne viruses, most members of which are transmitted by ticks. Here we report the genetic and biological characterization of a new thogotovirus, designated Oz virus (OZV), isolated from the hard tick Amblyomma testudinarium in Ehime, Japan. OZV efficiently replicated and induced a cytopathic effect in Vero cells, from which enveloped pleomorphic virus particles were formed by budding. OZV could also replicate in BHK-21 and DH82 cells and caused high mortality in suckling mice after intracerebral inoculation. Phylogenetic analyses of six viral proteins indicated that OZV is clustered with Dhori and related viruses, and is most closely related in glycoprotein (GP) and matrix protein (M) sequences to Bourbon virus, a human-pathogenic thogotovirus discovered recently in the United States. Our findings emphasize the need for understanding the geographic distribution and ecology of OZV and related viruses and for reevaluation of the medical and public health importance of thogotoviruses.

Spinal fusion on adolescent idiopathic scoliosis patients with the level of L4 or lower can increase lumbar disc degeneration with sagittal imbalance 35 years after surgery

Introduction

The purpose of this study was to investigate the long-term incidence of lumbar disc degeneration and Modic changes in the non-fused segments of patients with adolescent idiopathic scoliosis (AIS) who previously underwent spinal fusion.

Methods

Study subjects consisted of 252 patients with AIS who underwent spinal fusion between 1968 and 1988. Of 252 patients, 35 subjects underwent lumbar spine MRI and whole spine X-ray examination. The mean patient age at the time of follow-up was 49.8 years, with an average follow-up period of 35.1 years. We classified the subjects into two groups based on the lowest fused vertebra: H group whose lowest fused vertebra was L3 or higher levels and L group whose lowest fused vertebra was L4 or lower levels.

Results

The L group had significantly advanced disc degeneration on MRI. There was no significant difference between two groups in Modic changes. The L group showed less lumbar lordosis than the H group (H group: 48.1 degrees; and L group: 32.1 degrees) and greater SVA (H group: 1.2 cm; and L group: 5.5 cm).

Conclusions

In AIS patients, 35 years after spinal fusion surgery on average, we evaluated lumbar disc degeneration and Modic changes of the non-fused segments. In patients with the lowest fusion level at L4 or lower, there were reduced lumbar lordosis, considerable SVA imbalance, and severe disc degeneration compared with those with the lowest fusion level at L3 or higher. The lowest fusion level at L3 or higher is recommended to reduce disc degeneration in midlife.

Bone Mineral Density and Physical Performance of Female Patients 27 Years or Longer after Surgery for Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective cohort study.

PURPOSE

To assess bone mineral density (BMD) and bone metabolism ≥27 years after surgery in female patients who underwent spinal fusion for adolescent idiopathic scoliosis (AIS) during adolescence and to determine their associations with physical performance.

OVERVIEW OF LITERATURE

There are no studies investigating postsurgical BMD in middle-aged AIS patients.

METHODS

This study included 23 patients who provided informed consent among 229 female patients with AIS who underwent spinal fusion from 1968 until 1988. Average age at the time of observation was 48.8 years. BMD was measured at the left femoral neck, and the levels of two bone metabolism markers-procollagen type 1 N-terminal propeptide (P1NP) and tartrate-resistant acid phosphatase 5b (TRACP-5b)-were measured from blood samples. Physical performance was measured using grip strength, sit-ups, sit-and-reach, side step, and standing long jump.

RESULTS

Mean BMD was 0.784 g/cm2. According to the World Health Organization diagnostic criteria, one subject (4.3%) had osteoporosis, whereas nine subjects (39.1%) had osteopenia. In patients with osteoporosis or osteopenia, P1NP and TRACP-5b levels were high, and BMD loss was because of high metabolic turnover. All calculated standard scores for physical performance were lower in the study cohort than in healthy individuals. There was a positive correlation between BMD and the standard score for grip strength, whereas there were weak positive correlations between BMD and the standard scores for side step and standing long jump.

CONCLUSIONS

In female AIS patients who underwent spinal fusion in adolescence, 4.3% and 39.1% had osteoporosis and osteopenia, respectively, ≥27 years after surgery. Exercise performance of these patients was poor compared with the national standards. In these patients, increased physical activity should be encouraged to prevent BMD loss in middle age.

Isolation and characterization of Tarumizu tick virus: A new coltivirus from Haemaphysalis flava ticks in Japan

During the course of tick-borne virus surveillance in Japan, three independent isolates of probably the same virus were obtained from three geographically distant populations of the hard tick Haemaphysalis flava. Genome analyses of the three isolates demonstrated that they were closely related but distinct strains of a novel virus, designated Tarumizu tick virus (TarTV), which has a genome of 12 double-stranded RNA segments. The development of the virus-induced cytopathic effects on BHK cells significantly varied according to virus strains. Ten out of 12 segments of TarTV appeared to encode putative orthologs or functional equivalents of viral proteins of Colorado tick fever virus (CTFV) and Eyach virus, suggesting that TarTV is the third member of the genus Coltivirus in the family Reoviridae. This was supported by the facts that the 5'- and 3'-terminal consensus sequences of coltivirus genomes were found also in TarTV genome, and segment 9 of TarTV had sequence and structural features that may mediate a stop codon read-through as observed in that of CTFV. However, segment 7 and 10 of TarTV had no significant sequence similarities to any other proteins of known coltiviruses. Electron microscopic analysis demonstrated that TarTV particle had a non-enveloped bilayer icosahedral structure, and viral inclusion bodies were formed in infected cells. TarTV could infect and replicate in several mammalian cell lines tested, but show no clinical symptoms in intracerebrally inoculated mice. Taken together, our findings provide new insights into genetic diversity and evolution of the genus Coltivirus.

Midlife changes of health-related quality of life in adolescent idiopathic scoliosis patients who underwent spinal fusion during adolescence

PURPOSE

Our previous study reported a good health-related quality of life (HRQOL) in adolescent idiopathic scoliosis (AIS) patients 21 years or more after surgery. The purpose of this study is to investigate midlife changes in HRQOL among AIS patients who passed further 5 years from the previous survey.

METHODS

Subjects were 252 individuals who underwent spinal fusion for AIS between 1968 and 1988. The survey was administered twice-in 2009 and in 2014 using Scoliosis Research Society Patient Questionnaire (SRS-22). We analysed survey responses from 42 individuals (39 females, 3 males) who responded to both surveys.

RESULTS

The average scores for each respective domain of the SRS-22 in 2009 and 2014, respectively, were: function, 4.3 and 4.2; pain, 4.3 and 4.3; self-image, 3.0 and 2.9; mental, 3.9 and 3.8; satisfaction, 3.6 and 3.5. There were no significant differences in any domain of the SRS-22 between 2009 and 2014. Comparing non-fused segments of the lumbar spine of patients with fewer than four discs remaining with patients with four discs or more remaining, SRS-22 satisfaction score decreased more in patients with fewer than four discs (change in patients with four discs or more: -0.02; change in patients with fewer than four discs: -0.38; P = 0.05).

CONCLUSION

Each SRS-22 subscore was similar between 2009 and 2014 surveys. Those scoliosis patients who underwent spinal fusion during adolescence had good HRQOL scores in midlife. Even after five years passed, good conditions were maintained.

Influenza A virus infection in Japanese wild boars (Sus scrofa leucomystax)

Serum samples were collected from 385 wild boars between 2010 and 2013 to examine the seroprevalence of influenza A virus (IAV) in Japan. Antibodies against IAV were identified using a commercial kit in 13 wild boars (3.4%). To identify the serotypes, positive sera were examined by virus-neutralization test using representative serotypes and strains. Three wild boars in Yamaguchi and four in Tochigi showed the highest antibody titers against the pandemic H1N1 2009 virus and classical swine H1N1 virus strains, respectively. These data indicate that wild boars may have close contact with humans and domestic pigs and therefore that there is potential for IAVs to reassort in wild boars as they have been shown to do in pigs.

Novel pre-therapeutic scoring system using patient and haematological data to predict facial palsy prognosis

OBJECTIVES

We describe a novel scoring system, the facial Palsy Prognosis Prediction score (PPP score), which we test for reliability in predicting pre-therapeutic prognosis of facial palsy. We aimed to use readily available patient data that all clinicians have access to before starting treatment.

DESIGN

Multicenter case series with chart review.

SETTING

Three tertiary care hospitals.

PARTICIPANTS

We obtained haematological and demographic data from 468 facial palsy patients who were treated between 2010 and 2014 in three tertiary care hospitals. Patients were categorised as having Bell's palsy or Ramsey Hunt's palsy.

MAIN OUTCOME MEASURES

We compared the data of recovered and unrecovered patients. PPP scores consisted of combinatorial threshold values of continuous patient data (eg platelet count) and categorical variables (eg gender) that best predicted recovery. We created separate PPP scores for Bell's palsy patients (PPP-B) and for Ramsey Hunt's palsy patients (PPP-H).

RESULTS

The PPP-B score included age (≥65 years), gender (male) and neutrophil-to-lymphocyte ratio (≥2.9). The PPP-H score included age (≥50 years), monocyte rate (≥6.0%), mean corpuscular volume (≥95 fl) and platelet count (≤200 000 /μL). Patient recovery rate significantly decreased with increasing PPP scores (both PPP-B and PPP-H) in a step-wise manner. PPP scores (ie PPP-B score and PPP-H score) ≥2 were associated with worse than average prognosis.

CONCLUSIONS

Palsy Prognosis Prediction scores are useful for predicting prognosis of facial palsy before beginning treatment.

Physical Activities and Lifestyle Factors Related to Adolescent Idiopathic Scoliosis

BACKGROUND

In addition to genetic factors, environmental and lifestyle factors are thought to play an important role in the onset of adolescent idiopathic scoliosis (AIS). This cross-sectional study was conducted to explore lifestyle factors related to AIS.

METHODS

This study included 2,759 Japanese female junior high school students who planned a secondary screening after an initial moiré topography screening indicated possible scoliosis. The students and their mothers, or guardians, were asked to fill out a questionnaire consisting of 38 questions about demographic factors, lifestyle-related factors, social factors, household environment, participation in sports, health status, and factors related to the mother's pregnancy and delivery. The questionnaire was completed by 2,747 students (a 99.6% response rate). After excluding students with heart disease, neurological disease, or a congenital vertebral anomaly, 2,600 students were eligible for assessment. After undergoing a secondary screening with standing radiographs of the spine, students were assigned to the normal (control) group if radiographs showed a curve of <15° or to the scoliosis group if they had a curve of ≥15°. The odds ratios (ORs) for AIS in relation to the possible risk or preventive factors were estimated by logistic regression analyses.

RESULTS

No lifestyle-related factor was significantly associated with AIS. However, AIS was associated with classical ballet training (OR, 1.38; 95% confidence interval [CI], 1.09 to 1.75); the odds of AIS developing increased as the child's frequency of training, number of years of experience, and duration of training in ballet increased. The OR for AIS was 1.5 times higher for participants whose mothers had scoliosis. AIS was also associated with a low body mass index (BMI). These associations remained even after mutual adjustment was performed.

CONCLUSIONS

No association was found between AIS and lifestyle-related factors. However, classical ballet training, a family history of scoliosis, and low BMI may be associated with AIS.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Characterization of canine coronavirus spread among domestic dogs in Vietnam

Canine coronavirus (CCoV) is an important pathogen that causes enteritis in dogs, but there is no information on CCoV infection in Vietnam. To examine the prevalence of CCoV infection among Vietnamese dogs, 201 serum samples were analyzed by virus-neutralization (VN) test. The results showed that antibody against CCoV-II was present in 87 dogs (43.3%). To detect genes of CCoV, fecal samples collected from 30 diarrheic and 50 healthy dogs were examinated by RT-PCR, confirming that 2 diarrheic dogs and 5 healthy dogs were positive for CCoV. Nucleotide sequences of N-terminal region of spike (S) gene indicated that CCoV strains were divided into two subgenotypes, CCoV-IIa and -IIb, respectively. Furthemore, we succeeded in isolating CCoV/dog/HCM47/2015, the isolate was plaque-purified three times, and 3’-terminal one-third of the genome was analyzed. Interestingly, the plaque-purified virus had a large deletion in ORF3abc and E genes (1,165 nt), and a short deletion in ORF7b gene (60 nt), suggesting that these regions are not necessary for in vitro replication of CCoV. Next, the antigenicity between the isolated CCoV-IIb and the other CCoV-IIa was compared by VN test, revealing that antigenicty of the isolated CCoV is equal or higher than that of the other CCoV. In summary, two subgenotypes of CCoV-II are spreading among Vietnamese dogs. The isolated virus with a large deletion after in vitro passage may be useful for the development of vaccine, owing to its antigenicity and efficient viral growth in vitro.

Isolation and phylogenetic analysis of canine distemper virus among domestic dogs in Vietnam

Canine distemper virus (CDV) is one of the most serious pathogens found in many species of carnivores, including domestic dogs. In this study, hemagglutinin (H) genes were detected in five domestic Vietnamese dogs with diarrhea, and two CDVs were successfully isolated from dogs positive for H genes. The complete genome of one isolate, CDV/dog/HCM/33/140816, was determined. Phylogenetic analysis showed that all Vietnamese CDVs belonged to the Asia-1 genotype. In addition, the H proteins of Vietnamese CDV strains were the most homologous to those of Chinese CDVs (98.4% to 99.3% identity). These results indicated that the Asia-1 genotype of CDV was the predominant genotype circulating among the domestic dog population in Vietnam and that transboundary transmission of CDV has occurred between Vietnam and China.

Detection of novel ferret coronaviruses and evidence of recombination among ferret coronaviruses

In an epidemiological study of ferret coronaviruses (FRCoVs), novel FRCoV strains (Saitama-1 and Aichi-1) were detected by reverse transcription-polymerase chain reaction (RT-PCR) and nucleotide sequence analysis of partial RNA-dependent RNA polymerase (RdRp) genes. Phylogenetic analysis indicated that these strains belonged to different clusters from other FRCoV strains. Next, the nucleotide sequence of the 3′-terminal region of Saitama-1 (8271 bases) strain was determined and compared with those of the other FRCoVs, indicating that the Saitama-1 strain differed from the previously reported MSU-1 and MSU-2 strains in the regions encoding spike (S) protein, nucleocapsid, and open reading frame 7b. Furthermore, the results of SimPlot analysis indicated that FRCoV (MSU-2 strain) emerged via a recombination event of S protein between the MSU-1 and Saitama-1 strains. This mechanism is similar to that responsible for the emergence of type II feline coronavirus. This information will be useful for understanding the pathogenesis of FRCoV in ferrets.