Severe Generalized Epidemic Myalgia in an Adult due to Human Parechovirus Type 3: A Case Report.

Parechovirus A type 3 (PeVA3) is most commonly transmitted to adults from children. Although PeVA3 infection is rarely diagnosed, as the symptoms are generally mild and self-limiting, this infection has been associated with epidemic myalgia in Japan. The patient, a 37-year-old man, presented with severe generalized myalgia, inability to open his mouth, and orchitis, which resolved over a period of 10 days. All members of his family were thought to have been infected with PeVA3 during a visit to an amusement park. Although the source of infection and inability to open his mouth are atypical, the acute generalized muscle symptoms made us suspect epidemic myalgia and enabled us to make a diagnosis of PeVA3 infection.

Enhanced osteolytic potential of monocytes/macrophages derived from bone marrow after particle stimulation.

BACKGROUND: Total hip replacement can be complicated by periprosthetic osteolysis. Monocytes/macrophages play a major role in the formation of the foreign body granulomas induced by wear debris. We hypothesized that periprosthetic monocytes/macrophages do not only accelerate inflammatory and osteoclast-mediated osteolytic processes, but also resorb periprosthetic bone directly by themselves. This study was designed to evaluate the osteolytic potential in vitro of monocytes/macrophages derived from bone marrow. METHODS: Monocytes/macrophages were produced by filtration of rat bone marrow cells, followed by culture in the presence of macrophage-colony stimulating factor (M-CSF). Monocyte/macrophage properties were ascertained using immunocytochemistry and phagocytic activity. Osteolytic cytokines and extracellular matrix degrading proteinases were quantified at the mRNA level. RESULTS: Adherent cell fraction was immunoreactive for the monocyte/macrophage specific marker CD68 and active in the phagocytosis of carbon particles up to 72 h. They also showed immunoreactivity to cathepsin K, IL-1beta, IL-6, and M-CSF, but mostly did not react to TRAP. mRNA levels of osteolytic cytokines and extracellular matrix degrading proteinases were enhanced, but that of RANKL were not. Monocytes/macrophages resorbed dentine discs and carbonated calcium phosphate was very actively resorbed after stimulation with titanium particles. DISCUSSION: Harvested bone marrow cells expressed monocyte/macrophage phenotype, but not osteoclastic markers. The capacity of these cathepsin-K-positive phagocytic cells to resorb dentine discs and carbonated calcium phosphate in vitro suggests a direct role of monocytes/macrophages in bone resorption and periprosthetic osteolysis. The finding supports our hypothesis and previous histomorphometric observations on the presence of such osteolytic macrophages in vivo around loosening prosthesis.

Skeletal anchorage for orthodontic correction of severe maxillary protrusion after previous orthodontic treatment.

The correction of a severe maxillary protrusion in an adult by distal movement of the maxillary molars has been one of the most difficult biomechanical problems in orthodontics. This article reports on the treatment of an adult case of severe maxillary protrusion and a large overjet treated with a skeletal anchorage system. A female patient, age 22 years and 3 months, complained of the difficulty of lip closure due to severe maxillary protrusion with a gummy smile. Overjet and overbite were +7.6 mm and -0.9 mm, respectively. She had a history of orthodontic treatment in which her maxillary first premolars were extracted. In order to conduct distal movement of the maxillary molars, anchor plates were placed in the zygomatic process. After achieving a Class I molar relationship, retraction and intrusion of the maxillary incisors were performed. After a 2-year treatment, an acceptable occlusion was achieved with a Class I molar relationship. Her convex facial profile with upper lip protrusion was considerably improved, and the lips showed less tension in lip closure. After a 2-year retention period, an acceptable occlusion was maintained without recurrence of maxillary protrusion, indicating a stability of the occlusion. The result of this treatment indicated that skeletal anchorage is of great importance as a remedy for achieving intrusion and retraction of the maxillary incisors in cases of severe maxillary protrusion with a patient who had previous orthodontic treatment.

Finite element growth analysis for the craniofacial skeleton in patients with cleft lip and palate.

The purpose of this study was to clarify the differences in the nature of craniofacial growth between subjects with normal occlusion and patients with unilateral cleft lip and palate (CLP) in terms of the size, shape and principal growth direction of craniofacial skeleton using finite element method (FEM). Lateral cephalograms were taken of 40 subjects as normal group and 178 patients as CLP group. These subjects were divided into seven developmental ages of 4-, 6-, 8-, 10-, 12-, 14- and 18-year-old. For the finite element analysis, the craniofacial complex was discretized into seven structures or elements with three nodal points in each after tracing each lateral cephalogram on acetate paper. For each stage, the growth parameters in CLP group were compared to those in normal group. The growth of upper facial skeleton and maxillary complex was more remarkably inhibited in CLP than in normal group. Especially, the growth inhibition of posterior maxillary complex in a vertical direction was remarkable in CLP group at any ages. Difference in the size and shape of entire mandibular skeleton between CLP and normal groups was not apparent. It is suggested that grow timing and peak velocity, an essential and key determinant to the success in orthodontic treatment, have been clarified in this study more clearly than in previous studies. It is hopefully anticipated to explore some key determinants to predict individual growth of the craniofacial skeleton near future.

Changes in urinary bone resorption markers (pyridinoline, deoxypyridinoline) resulting from experimentally-induced osteoarthritis in the temporomandibular joint of rats.

The purpose of this study was to quantify the urinary bone resorption markers, pyridinoline (Pyr) and deoxypyridinoline (Dpyr), excreted from experimentally-induced osteoarthritis (OA) in the temporomandibular joint (TMJ) of rats. Osteoarthritic lesions were induced by intra-articular injection of collagenase into the right TMJs of 16-week-old male rats. The whole day's urine was collected from each animal one day before the injection and 5, 7, 11 and 14 days after the injection. Urine samples were analyzed by high-perfomance liquid chromatography and fluorescence spectroscopy. Histological changes in condyle were examined by using paraffin sections with toluidine blue staining. Degenerative changes were observed in the articular cartilage of the experimental group on day 7 and day 14 after the injection of collagenase. The concentration of Pyr was remarkably high in the experimental group, and consequently the Pyr to Dpyr ratio was significantly higher (p<0.05) in the experimental group than in the control group from 7-14 days after the injection. These findings suggest that a urinary Pyr/Dpyr ratio would be available for the detection of degenerative changes in condyle relevant to temporomandibular joint osteoarthritis (TMJ OA).

Minocycline-induced periarticular black bones in inflamed joints which underwent arthroplastic reconstruction.

BACKGROUND: Minocycline-induced pigmentation of bone (black bone) is well described in tooth-bearing intra-oral bone, but is less known in periarticular bone in patients who have undergone total joint arthroplasty. On a retrospective basis, we investigated the short-term clinico-radiological results of total joint arthroplasties in which the patient developed minocycline-induced periarticular black bone. METHODS: We found 5 cases (0.08%), in 4 patients, of periarticular bone pigmentation revealed during total joint arthroplasties (2 hips, 2 knees, and 1 ankle) in our series of total joint surgeries (6,548 cases) over a 10-year time period in our 3 institutes. Their mean age was 56 years at surgery. All patients had received long-term minocycline treatment. Mean dosage and duration of minocycline was 160 mg/day and 2.2 years, respectively. Minocycline had been prescribed for reactive arthritis (one), rheumatoid arthritis (two) and late infection after total joint arthroplasty (two patients). Mean follow-up period was 3.4 years after the surgeries. RESULTS: All cases had black or brown pigmentation in the periarticular bones during the surgery. There was no pigmentation in the cartilage or soft tissues of the joints. The mean Japanese Orthopaedic Association (JOA) score or Japanese Society for Surgery of the Foot (JSSF) scale for rheumatoid arthritis foot and ankle joints at latest follow-up (case 1, 66; case 2, 87; case 3, 77; case 4, 77; case 5, 80) improved compared to those of pre-surgery (case 1, 47; case 2, 45; case 3, 55; case 4, 34; case 5, 55). No implant loosening was noted on radiographic examination during the follow-up period. No abnormal bone formation, bone necrosis, hemosiderin deposition, malignancy or metallic debris was found on histological examination. CONCLUSIONS: No clinico-radiological symptoms of total joint arthroplasties showed in the patients with minocycline-induced periarticular black bone in the short-term. Systemic minocycline treatment has the potential to induce significant black pigmentation of many tissues. In particular, minocycline-induced pigmentation of periarticular bone may be accelerated by inflammation due to rheumatic or pyogenic arthritis. Surgeons should recognize the risk of bone pigmentation in inflamed joints due to the systemic treatment of minocycline and explore its influence on periarticular bone and total joint arthroplasty in the long-term.

Effects of sutural distraction osteogenesis applied to rat maxillary complex on craniofacial growth.

PURPOSE: This study was designed to investigate the effects of artificial mechanical separation of the circummaxillary sutures on craniofacial growth in growing rats. MATERIALS AND METHODS: Twenty 4-week-old Wistar strain male rats were divided equally into experimental and control groups. In the experimental group, 4 holes were made on the maxillary and temporary bones, and expansion appliances were placed into the holes for sutural separation bilaterally. The operated control group underwent sham surgery only. Lateral and dorsoventral cephalograms were taken of the animals every 2 weeks from age 4 to 12 weeks. Linear and angular measurements on the lateral cephalograms were analyzed and subjected to statistical treatment with Student's t-test. All animals were killed for histologic examination 8 weeks after the initiation of the experiment. RESULTS: Nasomaxillary growth and the forward displacement were significantly larger in the experimental group than in the controls (P <.01). New bone formation was clearly observed in the (mechanically separated) sutural space in association with normal healing of the sutural structures. CONCLUSIONS: These findings show that mechanical separation of the circummaxillary sutures, as a new orthopedic approach, accelerated nasomaxillary growth, in this experimental model.

Immunolocalization of vascular endothelial growth factor in rat condylar cartilage during postnatal development.

It is well known that angiogenesis is essential for the replacement of cartilage by bone during skeletal growth and regeneration. To address angiogenesis of endochondral ossification in the condyle, we examined the appearance of vascular endothelial growth factor (VEGF) and its receptor Flt-1 in condylar cartilage of the growing rat. The early expression of VEGF at various sites during condylar cartilage development indicates that VEGF plays a role in the regulation of angiogenesis at each site of bone formation. From the findings of Flt-1 immunoreactivity, the VEGF produced by the chondrocytes of the hypertrophic zone should contribute to the promotion of endothelial cell proliferation and to stimulate migration and activation of osteoclasts in condylar cartilage, resulting in the invasion of these cells into the mineralized zone.

Linear polarized near-infrared irradiation stimulates mechanical expansion of the rat sagittal suture.

Mechanical sutural separation has been carried out in clinical orthodontics for controlling the growth of the craniofacial skeleton. This study was designed to evaluate the effects of linear polarized near-infrared ray irradiation on the sutural expansion of rat sagittal suture. Twenty 8-week-old Wistar strain male rats were equally divided into experimental and control groups. Suture expansion was carried out for 5 days for all animals using an expansion appliance. The experimental animals were subjected to linear polarized near-infrared irradiation. This study has demonstrated that linear polarized near-infrared irradiation stimulates sutural expansion without any pathological changes.

Viscoelastic properties of bovine retrodiscal tissue under tensile stress-relaxation.

To test the hypothesis that the condylar part of the retrodiscal tissue of the temporomandibular joint exhibits resistance to tensile force, we investigated its viscoelastic properties and stress-relaxation behavior under tension. Ten specimens were tested. Stress-relaxation tests were conducted from four different initial stress levels. The tissue exhibited a non-linear stress-strain relationship, which could be represented by a bilinear relation of two line segments. The stress-relaxation curves showed a marked drop in load during the initial 10 s and after 2 min the stress reached an almost steady non-zero level. This feature can be well represented by Kelvin's model. It is concluded that the condylar part of the retrodiscal tissue (a) exhibits a non-linear strain-dependent viscoelastic behavior (b), has a great capacity for energy dissipation and resistance to tensile forces, and (c) contributes to maintain the position of the disc relative to the condyle during jaw closing.