Preventive effects of hyaluronan from deterioration of gait parameters in surgically induced mice osteoarthritic knee model

OBJECTIVE

Osteoarthritis (OA) leads to pain and loss of function in affected joints. Gait disturbance results from these symptoms of OA, and gait analysis can be important to evaluate the progression of OA. The purpose of this study was to analyze gait pattern in a rodent model of OA and to assess the effects of intra-articular injection of hyaluronan (IAI-HA) by gait analysis, along with histological evaluation.

DESIGN

OA was induced by destabilization of the medial meniscus (DMM) of C57BL/6 mice. IAI-HA started 3 weeks after DMM surgery. Mice were allocated to three groups and were given either 800-kDa HA (800-HA), 6000-kDa HA (6000-HA) or saline. We compared these three groups with a sham group by gait analysis using CatWalk. Histological evaluation was performed to assess articular cartilage changes in the knee joints.

RESULTS

Mice injected with 800-HA or 6000-HA showed gait patterns similar to that of the sham mice, while the saline-injected group showed gait disturbances 12 and 16 weeks after DMM surgery. Histological changes in articular cartilage were similar among the 800-HA, 6000-HA and saline-treated groups, demonstrating OA progression throughout the experimental time points. Positive gait-related effects of IAI-HA might occur by its pain relieving effect and/or by preventing contracture.

CONCLUSION

IAI-HA prevented gait disturbances in the DMM model, but did not prevent histological changes associated with OA progression.

Treatment efficiency of mini-implant-borne distalization depending on age and second-molar eruption

OBJECTIVE

The aim of this study was to evaluate the efficiency of molar distalization depending on age and second-molar eruption using the Beneslider.

MATERIALS AND METHODS

Treatment of 51 patients (mean age 17.8 ± 9.6 years) was investigated retrospectively by means of pre- and posttreatment cephalograms. Patients were divided into three groups: 14 children with unerupted upper second molars (group 1), 23 adolescents with second molar in place (group 2), and 14 adults (group 3). The distalization forces applied were 2.4 N in group 1 and 5.0 N in groups 2 and 3. Treatment changes were evaluated and examined statistically for significant differences.

RESULTS

In all patients a Class I molar relationship was achieved. All mini-implants remained stable during treatment. Mean distalization distance as measured by the displacement of the center of resistance was 3.6 ± 1.9 mm (range 1.2-8.5 mm depending on treatment needs). Since no significant tipping was detected, the type of movement can be described as bodily movement. Mean overall distalization speed was 0.6 ± 0.4 mm per month. There were no statistical differences between the groups.

CONCLUSION

We found the Beneslider to be an effective appliance that enables bodily distalization in adequate treatment time. The higher resistance due to erupted second molars can be compensated by the use of higher forces without significantly reducing distalization speed.

Altered cerebellum development and dopamine distribution in a rat genetic model with congenital hypothyroidism

Thyroid hormones play crucial roles in the development and functional maintenance of the central nervous system. Despite extensive studies of the neural function of thyroid hormones, little is known about the effects of hypothyroidism on behavioural traits and the mechanisms underlying such effects. In the present study, we report an investigation of congenitally hypothyroid mutant rdw rats, revealing a novel function of thyroid hormones in the central nervous system. The rdw rats were subjected to behavioural analyses such as the rotarod test, open field test and circadian activity measurement. To determine the cause of behavioural disorders, cerebellar morphogenesis was examined by immunohistochemical analysis, and the axonal transport of dopamine in the nigrostriatal pathway was analysed by high-performance liquid chromatography and western blotting. The effects of thyroxine administration to the rdw rats were examined by behavioural analysis. The rdw rats showed severe impairment of motor coordination and balance. This could be explained by the fact that the rats showed severe retardation of cerebellar morphogenesis, which correlates with the small somata and poor dendritic arborisation of Purkinje cells and retarded migration of granule cells particularly during the first two postnatal weeks. Moreover, the rdw rats showed hypoactivity, characterised by decreased circadian locomotor activity. After weaning, thyroxine administration improved the dwarfism in rdw rats but had no effect on cerebellar function. In addition, the rdw rats showed anxiety and depression intrinsically to novel surroundings. Interestingly, the rdw rats showed high levels of dopamine in the substantia nigra and low levels in the striatum, an important centre for the coordination of behaviour. Furthermore, low levels of tubulin in the striatum were detected, indicating the aberrant axonal transport of dopamine in the nigrostriatal pathway as a result of the reduced delivery of microtubules. These findings indicate an important function of thyroid hormones in cerebellar formation and in the regulation of axonal transport of dopamine. Moreover, rdw rats will be useful for studies of brain function and behavioural disorders in congenital hypothyroidism.

Fabrication of Y2O3-Doped Zirconia/Gadolinia-Doped Ceria Bilayer Electrolyte Thin Film SOFC Cells of SOFCs by Single-Pulsed Laser Deposition Processing

An 8 -mol. % Y₂O₃-doped zirconia/10-mol. % GdO₂-doped ceria (YSZ/GDC) bilayer electrolyte and a Gd_0.5Sr_0.5CoO₃ (GSCO) cathode were deposited by a single-processing, pulsed laser deposition (PLD) method to fabricate anode support cells. No additional heat treatment was needed. Laser frequencies of 10, 20, and 100 Hz were used to deposit bilayer electrolytes between the NiO–YSZ (NiO:YSZ = 60:40 wt. %) anode substrate and the GSCO cathode thin film. The GDC thin film produced at 10 Hz was smooth, well-crystallized, and highly dense. The crystallinity of the GSCO cathode on the GDC was also improved. We concluded the GDC crystallinity affected the crystallinity of the cathode thin film. The resistivity of the YSZ single layer (5.7 μm thickness) was 1.4 times higher than that of the YSZ/GDC bilayer (YSZ 3.0 μm thickness, GDC 2.7 μm thickness) at 600 °C and that of the YSZ-GDC interface became low. The optimum YSZ thickness was found to be approximately 3.0 μm, at which thickness there was effective blocking of the passage of hydrogen molecules and electrons. A cell with a YSZ (3.0 μm thickness, fabricated at 20 Hz)/GDC (5.0 μm thickness, fabricated at 10 Hz) bilayer and GSCO cathode thin film exhibited a maximum power density of 400 mW·cm^–2 at a comparatively low temperature of 600 °C.

Mandibular reconstruction using a poly(L-lactide) mesh combined with autogenous particulate cancellous bone and marrow: a prospective clinical study

The purpose of this study was to evaluate the stability and viability of mandibular bone regeneration using a poly(L-lactide) (PLLA) mesh and autogenous particulate cancellous bone and marrow (PCBM). Sixty-two procedures were undertaken at eight hospitals (22 malignant tumours, 30 benign tumours, five cysts, two osteomyelitis, two trauma, and one atrophy of the alveolar ridge); the success rate was 84%. The follow-up period was between 9 and 200 months (mean 88.2 months). Consequently, bone regeneration at 6 months postoperation was excellent in 35 cases (57%), good in 17 cases (27%), and poor in 10 cases (16%). In six of the 'poor' cases, the PLLA mesh was removed due to local infection early after surgery. Bone resorption>20% was observed in only one of 46 cases with a follow-up term of >1 year. There were no signs of any other adverse effects except in one case where a section of the tray broke off late in the follow-up period. It is concluded that this method is stable and effective due to favourable morphological and functional recovery and low invasiveness. It may thus be a useful alternative procedure for mandibular reconstruction.

Impact of five SNPs in dopamine-related genes on executive function

OBJECTIVES

Dopamine neurotransmission is a critical factor for executive function, which is controlled by the prefrontal cortex in humans. Although the contribution of genetic factors to the regulation of brain dopaminergic activity is widely acknowledged, identification of a genotype-phenotype association has not yet been clearly established. In this study, we therefore evaluated the effects of five functional single-nucleotide polymorphisms (SNPs) in specific genes related to dopamine neurotransmission on executive function in a general population.

MATERIALS AND METHODS

Participants of the health examination at the Shimane Institute of Health Science were recruited for this study (n = 964). To evaluate executive function, the Frontal Assessment Battery (FAB) was administered. SNPs were genotyped using the TaqMan method.

RESULTS

A significant association was found between an SNP in the catechol-O-methyltransferase (COMT) gene (rs4680) encoding the low-activity Met allele and FAB score (P = 0.003). Of note, the flexibility subset of the FAB was associated with the SNP in COMT (P = 0.003) after adjustment for confounding factors. The generalized multifactor dimensionality reduction method identified that the combination of two SNPs in the COMT gene (rs4680) and the dopamine D4 receptor gene (rs1800955) had a significant effect on FAB score.

CONCLUSIONS

Our study indicates a contribution of rs4680 in the COMT gene to the variability in executive function, as assessed by the FAB. In addition, we have indicated that a complex gene-gene interaction between SNPs in the genes related to dopamine neurotransmission may influence executive function in a general population.

Delaying embryo development by storing at 4°C for synchronization to recipients in microinjection technique in rabbits

Short-term storage of embryos at low temperature induces developmental arrest of the embryo and would appear to be a valuable aid in embryo-transfer techniques to avoid wasting embryos. Embryo storage at 4°C was examined to allow synchronization with embryo-transfer recipients using the microinjection technique. Superovulation was induced in female Japanese White donor rabbits four days before mating with males. At the same time, control recipients were injected with human chorionic gonadotropin (hCG) to allow synchronization (R1); the hCG injections were delayed by 24 h in the experimental group (R2). DNA constructs for expressing human C-reactive protein or apolipoprotein AII were microinjected into the male pronuclei of the ova. The microinjected embryos were immediately transferred to recipients (R1) or stored at 4°C in phosphate-buffered saline containing 10% fetal bovine serum. After 17-20 h, the stored embryos were incubated at 37°C for one hour, and the morphologically normal embryos were transferred to recipients (R2). In the R1 rabbits, 855 embryos were transferred to 29 recipients, and 72.4% of the recipients became pregnant. Seven of the 84 offspring were transgenic. In the R2 rabbits, 478 embryos were transferred to 16 recipients, and 62.5% of the recipients became pregnant. Two of the 39 offspring were transgenic. There were no differences in pregnancy rate, litter size and transgenic integration rate between R1 and R2. These results suggest that the short-term 4°C storage of microinjected embryos can be a valuable method for synchronization with recipients, and reducing wastage of embryos and the sacrifice of rabbits.

Short communication: Molecular typing of Prototheca zopfii from bovine mastitis in Japan

Prototheca zopfii causes bovine mastitis, resulting in reduced milk production and the secretion of thin watery milk with white flakes. Prototheca zopfii has been biochemically and serologically divided into at least 2 genotypes, P. zopfii genotype 1 and P. zopfii genotype 2. The latter is known to be the main causative agent of bovine protothecal mastitis. Prototheca zopfii was later reclassified into 5 varieties: var. zopfii (genotypes 1 and 2), var. 1 (formerly Prototheca blaschkeae), var. 3 (formerly P. moriformis), and var. portoricensis. In this study, the 18S ribosomal DNA sequences of diverse clinical specimens from different areas in Japan were studied to clarify the pathogenicity of P. zopfii var. zopfii. The phylogenetic tree revealed that all genotype 2 isolates were grouped in a cluster of P. zopfii var. zopfii SAG 2021(T) (type strain genotype 2), and were independent from the cluster of the genotype 1 isolates. Thus, all isolates from bovine mastitis in Japan were identified as P. zopfii genotype 2. Therefore, P. zopfii var. zopfii genotype 2 is associated with bovine mastitis.

Angiogenic activity of subchondral bone during the progression of osteoarthritis in a rabbit anterior cruciate ligament transection model

OBJECTIVE

To investigate the longitudinal angiogenic activity of subchondral bone and cartilage during the progression of osteoarthritis (OA) using a rabbit model of OA.

MATERIALS AND METHODS

OA was surgically induced by anterior cruciate ligament transaction (ACLT) in left knee of 12 months old female New Zealand white rabbits (n = 33). Histological examination, immunohistochemistry, and angiogenic activity assay was done at 0, 2, 4, 6, 8, 12 weeks after ACLT. Histologic evaluation was performed with haematoxylin and eosin, safranin-O staining to assess the OA change of medial femoral condyle (MFC) and lateral femoral condyle (LFC). CD31 immunohistochemistry was performed to confirm the vascular invasion at osteochondral junction. A co-cultured tubule formation assay was conducted to evaluate angiogenic activity of the subchondral bone and cartilage of MFC and LFC as well as synovium. Association between histological changes, angiogenic activity, and vascular invasion were evaluated.

RESULTS

OA changes increased in a time-dependent manner both in MFC and LFC. Angiogenic activity of subchondral bone showed a monomodal change during the OA progression, achieved a peak in the early to progressive stage and decreased to normal level in the late stage of OA. Surge of vascular invasion was observed following the increase of angiogenic activity in the progressive stage of OA. Angiogenic activity of cartilage did not change during the course of OA progression.

CONCLUSION

Angiogenic activity of subchondral bone was elevated in the early to progressive stage of OA and vascular invasion into the osteochondral junction followed.