Molecular genetics of RecQ helicase disorders

The RecQ helicases belong to the Superfamily II group of DNA helicases, and are defined by amino acid motifs that show sequence similarity to the catalytic domain of Escherichia coli RecQ. RecQ helicases have crucial roles in the maintenance of genome stability. In humans, there are five RecQ helicases and deficiencies in three of them cause genetic disorders characterised by cancer predisposition, premature aging and/or developmental abnormalities. RecQ helicase-deficient cells exhibit aberrant genetic recombination and/or DNA replication, which result in chromosomal instability and a decreased potential for proliferation. Here, we review the current knowledge of the molecular genetics of RecQ helicases, focusing on the human RecQ helicase disorders and mouse models of these conditions.

Genetic variation of the prevailing porcine respiratory and reproductive syndrome viruses occurring on a pig farm upon vaccination

Recurrence of porcine respiratory and reproductive syndrome (PRRS) was observed on a pig farm after introducing two PRRS live virus vaccines to combat preceding outbreaks. The phylogenetic analysis of the nucleotide sequence encoding the GP5 envelope glycoprotein and the nucleocapsid protein coding sequences (ORF5 and ORF7, respectively) showed a close genetic relationship between the new outbreak-related and one of the vaccine viruses, while the prevailing PRRS virus genetic variants disappeared from the farm. These findings, supported by the epidemiological data, indicate that the new variant PRRS viruses might originate from a vaccine virus and demonstrate the limited efficacy of modified live vaccines against heterologous PRRS virus strains.

Heating by an electron Bernstein wave in a spherical tokamak plasma via mode conversion

The first successful high power heating of a high dielectric constant spherical tokamak plasma by an electron Bernstein wave (EBW) is reported. An EBW was excited by mode conversion (MC) of an mode cyclotron wave injected from the low magnetic field side of the TST-2 spherical tokamak. Evidence of electron heating was observed as increases in the stored energy and soft x-ray emission. The increased emission was concentrated in the plasma core region. A heating efficiency of over 50% was achieved, when the density gradient in the MC region was sufficiently steep.

Nutritional status and associated factors in children aged 0–23 months in Granada, Nicaragua

OBJECTIVES

Nicaragua is one of two low-income countries in the Latin Americas. The objectives of this study were to clarify the nutritional status of children aged 0-23 months and to identify the associated factors in rural Nicaragua.

STUDY DESIGN AND METHODS

This was a cross-sectional study; a questionnaire survey was performed and anthropometric measurements were taken in Granada province, Nicaragua.

RESULTS

Seven hundred and fifty-six mothers with at least one child aged 0-23 months took part in this study. The proportion of underweight children [weight-for-age Z-score <-2 standard deviations (SD)] was 10.3%, while 30.1% of children exhibited stunted growth (height-for-age Z-score <-2 SD) and 5.0% were wasted (weight-for-height Z-score <-2 SD). Mothers' illiteracy or lack of formal education [odds ratio (OR)=3.476, P<0.01], a history of respiratory infection (OR=1.821, P<0.05) and a birth weight below the median (<3000 g; OR=1.704, P<0.05) were identified as risk factors for stunted growth. Breastfeeding for more than 12 months (OR=2.031, P<0.01), absence of participation in child growth monitoring (OR=1.956, P<0.05) and female gender of the child (OR=1.884, P<0.05) were identified as risk factors for underweight.

DISCUSSION

Despite the steady economic development in Nicaragua since 1990, child nutritional status has not improved as much as might be expected. The present study revealed that a mother's favourable sociodemographic characteristics and her active participation in health activities, such as child growth monitoring, can protect against child malnutrition, particularly against underweight. More attractive health education or antenatal care programmes might lead to substantial improvements in maternal and child health in this small, poor community.

Enhancement of ultraviolet-induced apoptosis by NF-kappaB decoy oligonucleotides

BACKGROUND

A decoy strategy utilizing oligonucleotides (ODN) containing the specific binding sequence of a certain transcription factor has been developed and is considered to be a potential new class of antigene therapy. However, the application of this new therapeutic modality to skin diseases has not been fully documented.

OBJECTIVES

The aim of this work was to examine the effects of the nuclear factor (NF)-kappaB decoy ODN on UV-elicited skin change.

METHODS

Mouse keratinocyte Pam 212 cells were transfected with NF-kappaB decoy ODN to examine the effects of the decoy ODN on ultraviolet (UV) B-induced apoptosis. Tape-stripped rat dorsal skin was treated with an ointment containing NF-kappaB decoy ODN for the examination of the in vivo impact of the decoy ODN on sunburned cell (SBC) formation and UVB erythema.

RESULTS

NF-kappaB decoy ODN specifically induced apoptosis of Pam 212 cells and SBC formation was significantly enhanced by topical NF-kappaB decoy ODN ointment, while UV-induced erythema was not affected.

CONCLUSIONS

These data suggest that enhancement of UV-induced apoptosis by NF-kappaB decoy ODN may play a cancer-preventive role by further eliminating photodamaged keratinocytes.

Konjak mosaic virus: the complete nucleotide sequence of the genomic RNA and its comparison with other potyviruses

Konjak mosaic virus (KoMV) belongs to the genus Potyvirus, family Potyviridae. The complete nucleotide sequence of KoMV F isolate (KoMV F) was determined. The genome is 9,544 nucleotides long excluding the 3' terminal poly A tail and encodes a typical potyviral 350-kDa polyprotein of 3,087 amino acids. Phylogenetic analysis using known potyvirus polyproteins shows that KoMV constitutes a branch with yam mosaic virus, close to another branch including Japanese yam mosaic virus, turnip mosaic virus, scallion mosaic virus and lettuce mosaic virus. The 3' terminal 1,842 nucleotides of a different isolate of KoMV, K-2, was also determined, covering the C-terminal 292 amino acids of the nuclear inclusion protein b (NIb), coat protein (CP), and the 3' untranslated region. The amino acid sequences of the KoMV F CP and the nucleotide sequences of the KoMV F 3' untranslated region showed 92.5 and 90.5% identity to the corresponding genes of K-2, 88.7-96.8 and 92.7-94.4% to those of Zantedeschia mosaic virus (ZaMV) isolates, 87.5-89.7% and 85.5-90.3% to those of Japanese hornwort mosaic virus (JHMV) isolates. These results showed that KoMV is a distinct potyvirus and that KoMV, ZaMV, and JHMV are members of the same potyvirus species. Considering that KoMV was the first of these to be described, ZaMV and JHMV may be considered isolates of KoMV.

Nucleotide sequence of melon yellow spot virus M RNA segment and characterization of non-viral sequences in subgenomic RNA

The nucleotide sequence of melon yellow spot virus (MYSV) M RNA segment was determined. The M RNA segment contains one open reading frame (ORF) encoding 308 amino acids (aa) in the sense orientation and another ORF encoding 1,127 aa in the complementary orientation, which were homologous to the NSm protein and G1/G2 glycoprotein precursor (Gp) protein, respectively. Amino acid sequences identities with the other tospovirus suggested that MYSV is closely related to groundnut bud necrosis virus and watermelon silver mottle virus. To analyze subgenomic RNA of the M RNA segment, RNA transcripts corresponding to the NSm and Gp genes were specifically amplified, and the nucleotide sequence of the 5' terminal region was determined. Sequence analysis of the NSm and Gp transcripts showed that they had a non-viral sequence 12-18 and 10-18 nucleotides long, respectively. Although these sequences varied considerably, in more than half of the cases, a cytosine residue was observed at the 3' end of the non-viral leader sequence, which suggests that the viral transcriptase prefers certain cap-donor sequences harboring a 3'CA dinucleotide.

Mandibular antegonial and ramus notch depths and condylar bone change

The present study sought to clarify the relationship between antegonial and ramus notch depths and condylar bone change, and analyse the effects of such change on craniofacial structure. The study sample was of 28 pre-orthodontic patients with signs and symptoms of temporomandibular joint (TMJ) disorders, who underwent helical computed tomography to diagnose their TMJ pathology. Craniofacial structures were compared between 14 subjects with bilateral condylar bone change (BBC group: two male and 12 female) and 14 subjects with no bone change (NBC group: two male and 12 female). Sella-nasion-point B (SNB) and point A-nasion-point B (ANB) angles were significantly smaller in BBC than in NBC, with ramus height and mandibular body lengths significantly shorter in BBC than in NBC. The BBC lower facial height and SN-Go-Ar angle, as well as antegonial and ramus notch depths, were significantly greater than in NBC, and the mandible was significantly more retruded in BBC than in NBC. These results showed that condylar bone change might be related not only to mandibular size (e.g. retrusion) but also to mandibular outline (including antegonial and ramus notch depth).

Comparison of condylar positions at intercuspal and reference positions in patients with condylar bone change

The purpose of this study was to investigate the condylar displacement from intercuspal position (IP) to reference position (RP), using a jaw movement measuring system with 6 d.f. and helical computed tomography (CT). The 19 patients included in the present study were divided into a group with bilateral condylar bone change (10 subjects, including the sub-groups with flattening and osteophyte formation) and a group with no condylar bone change (9 subjects). The results showed that the bone change group had significantly more superior, posterior and absolute horizontal IP to RP slides than the no bone change group. There was also a significant difference in the amount of antero-posterior and supero-inferior condylar IP-RP displacements related to the type of condylar bone change within the bone change group. The osteophyte sub-group showed the largest posterior displacement, and the flattening sub-group showed the largest superior displacement. These results suggested that this large IP-RP difference in the bone change group might be related to their temporomandibular joint (TMJ) pathology, and it might therefore be useful to keep this difference in mind as one of the clinical indices suggesting the presence of TMJ osteoarthritis (OA).

Observation of three cases of temporomandibular joint osteoarthritis and mandibular morphology during adolescence using helical CT

Temporomandibular joint (TMJ) osteoarthritis (OA) is a potential cause of craniofacial deformity. If TMJ OA appears during orthodontic treatment, the mandible usually rotates posteriorly, resulting in an unsatisfactory profile, especially in patients with pre-treatment mandibular retrusion. Although it is important to confirm the kind of TMJ pathosis at the start of orthodontic treatment, the relationship between TMJ OA, condylar remodelling and changes in craniofacial morphology remains unclear because of a lack of longitudinal studies. Elucidating this relationship might allow better prediction of post-treatment craniofacial morphology. In the present case reports, helical computed tomography and cephalometry were used to analyse relationships between the pattern and location of condylar remodelling and the changes in craniofacial morphology in three patients with TMJ OA.

Morphology of the articular eminence in temporomandibular joints and condylar bone change

The purpose of the present study was to investigate the relationship between the inclination of the articular eminence and temporomandibular joint (TMJ) pathology in orthognathic surgery patients with signs and symptoms of TMJ disorders. Twenty-one female orthognathic surgery patients with signs and symptoms of TMJ disorders were examined using pre-treatment helical computed tomography scans. The slope of the eminence in the medial, central and lateral sections of the subjects with osteophyte formation was significantly less than in the subjects with no bone change, and the medial section of the subjects with osteophyte formation was also significantly less steep than in the subjects with erosion. The central and lateral sections in the subjects with anterior disc displacement with reduction were significantly steeper than in subjects with anterior disc displacement without reduction. These results suggest that eminence flattening might occur during changes from erosion to osteophyte formation and from anterior disc displacement with reduction to anterior disc displacement without reduction. This appears to represent adaptation of the condyle, articular disc and articular eminence to changes in loading.

Formation of advanced tokamak plasmas without the use of an ohmic-heating solenoid

A new operational scenario of advanced tokamak formation was demonstrated in the JT-60U tokamak. This was accomplished by electron cyclotron and lower hybrid waves, neutral beam injection, and the loop voltage supplied by the vertical field and shaping coils. The Ohmic heating (OH) solenoid was not used but a small inboard coil (part of the shaping coil), providing less than 20% of total poloidal flux, was used. The plasma thus obtained had both internal and edge transport barriers, with an energy confinement time of 1.6 times H-mode scaling, a poloidal beta of 3.6, and a normalized beta of 1.6, and a large bootstrap current fraction (>90%). This result opens up a possibility to reduce, and eventually eliminate, the OH solenoid from a tokamak reactor, which will greatly improve its economic competitiveness.

Photodynamic therapy may be useful in debulking cutaneous lymphoma prior to radiotherapy

Photodynamic therapy (PDT) with topical 5-aminolaevulinic acid (5-ALA) is a promising new treatment for superficial malignant nonmelanoma tumours, including cutaneous malignant lymphoma. Here, we report a case of cutaneous anaplastic large cell lymphoma effectively treated by PDT with topical 5-ALA in combination with radiotherapy.

Relationship between occlusal curvatures and mandibular deviation in orthodontic patients with temporomandibular disorders

The aim of this study was to investigate the relationships between occlusal curvature (OC) and frontal craniofacial morphology in patients with and without temporomandibular disorders (TMD), using frontal cephalograms and a sophisticated measuring device (XYZAX S400A). Thirty-seven female orthodontic patients (mean age 24.0 years) were divided into a TMD group (n = 25) and no-TMD group (n = 12). In the TMD group, the lateral OCs of the mandibular second premolar, and first and second molars were significantly deeper on the deviated side than on the non-deviated side, and the anteroposterior OCs of the mandibular second premolar and first molar were also significantly shallower on the deviated side. In the no-TMD group, however, there were no significant differences in OCs between deviated and non-deviated sides. The differences between right and left lateral OCs in the mandibular second premolar and first and second molars, as well as the anteroposterior OCs in the mandibular first and second molars, showed significant correlations with mandibular deviation in the TMD group. On the other hand, in the no-TMD group, there was no significant correlation between OCs and mandibular deviation. The above results suggest that OCs might try to compensate for mandibular deviation in patients with TMD.