Dental and skeletal maturation in female adolescents with temporomandibular joint osteoarthritis.

Occurrence of temporomandibular disorders (TMDs) and temporomandibular joint (TMJ) osteoarthritis (OA) during adolescence may have interactions with mandibular and dental development. The aim of the present study was to investigate relationships between occurrence of TMD and TMJ OA and extents of dental and skeletal development in juvenile female patients. In total, 95 female adolescents (age range, 11-15 years) were selected. Among them, 15 subjects (control) had no signs of TMD, 39 TMD patients did not have OA (TMDnoOA), 17 TMD patients were at initial stage of TMJ OA (TMJOA), and 27 patients showed progressive stage of TMJ OA (TMJOA). Dental age was estimated by Demirjian's stages used in a previous study with Korean adolescents. Craniofacial parameters and cervical vertebrae maturation (CVM) stages, representing skeletal maturity levels, were measured using lateral cephalograms. The estimated dental age was significantly lower than chronological age in all groups, but CVM differences were not statistically significant. Dental age was the lowest, and differences between the chronological age and estimated dental age were the highest among initial stage of TMJOAs followed by progressive stage of TMJOAs, TMDnoOAs and control and were not associated with CVM stages. Cephalometric parameters revealed significant clockwise rotation of the mandible among the TMJOAs compared with controls and TMDnoOAs and were not associated with CVM stages as well. The juvenile female patients with TMD, particularly TMJ OA, showed retarded dental development, mandibular backward positioning and hyperdivergent facial profiles. The TMJ OA may be associated with retarded dental development but not with skeletal maturations.

A controllable double-well magneto-optical trap for Rb and Cs atoms.

We experimentally demonstrate a novel scheme to simultaneously confine two atomic species of (87)Rb and (133)Cs with adjustable spatial separation by a controllable double-well magneto-optic trap. Using a single-loop wire and a magnetic bias field, the two clouds, each containing more than 1 x 10(6) atoms, are spatially separated above and below the wire center of the double-well MOT. The cloud interdistance can be controlled by independently varying the wire current and external bias field. This allows to load the double-well magnetic trap, and to study the dynamics of cold collisions between two-species atoms.

Effects of mixed chimerism and immune modulation on GVHD, disease recurrence and survival after HLA-identical marrow transplantation for hematologic malignancies.

BACKGROUND: The success of allogeneic bone marrow transplantation(allo-BMT) is affected by underlying disease relapse. Although mixed chimerism(MC) is not necessarily a poor prognostic factor, several groups have suggested that MC is associated with an increased risk of disease relapse. There is evidence that patients with MC benefit from additional immunotherapy if the treatment is started in minimal residual disease status(mixed chimerism status), not in frank hematological relapse. The purposes of this study are to evaluate 1) the risk for relapse or graft rejection in correlation to persistent MC status after allo-BMT, and 2) the possibility of preventing relapse by immune modulation treatments (withdrawal or rapid taper-off of post-transplant immuno-suppression, additional interferon treatment, or the administration of donor lymphocytes) in hematologic malignancies. PATIENTS AND METHODS: Of 337 allogeneic donor-recipient pairs between March 1996 and August 1998, 12 patients who showed persistent or progressive MC and who received immune modulation treatments were evaluated. Twelve patients, median age 31 years(range 9 to 39 years), received an allo-BMT for: acute myelogenous leukemia(AML, n = 5), chronic myelogenous leukemia(CML, n = 4), acute lymphocytic leukemia(ALL, n = 3). Serial polymerase chain reaction(PCR) analysis of YNZ 22-, 33.6-minisatellites or Y chromosome-specific PCR analysis at short term intervals(pre- and post-transplant 1, 3, 6, 9, ... months) was performed. Once MC was detected, immune modulation treatments on the basis of increasing MC in an early phase of recurrence of underlying disease were started. RESULTS: Nine of 12 patients converted to complete chimerism(CC) (AML 5/5, CML 3/4, ALL 1/3). Four of 9 CC patients developed graft-versus-host disease(GVHD) grade < or = 2 during immune modulation. All were treated successfully with steroids. Three patients who were not converted to CC showed relapse of underlying diseases or graft failure. CONCLUSION: The results demonstrate that, in patients with hematologic malignancies after allo-BMT, persistent MC is associated with relapse of underlying diseases or graft failure. Furthermore, when patients receive early immune modulation treatment, MC can be changed to complete donor pattern chimerism and ultimately prevent relapse.

Fabrication of submicron titanium-alloy particles for biological response studies.

Biologic response to generated wear particles and subsequent aseptic loosening is a critical factor limiting the long-term survival of total hip replacements. To better understand the sequence of events leading to aseptic loosening and the role of the individual material components, fabricating metal particles similar to those present clinically is very important. We describe a simple milling technique to generate significant amounts of fine titanium-alloy (TiAlV) debris. A TiAlV rod was milled against a TiAlV plate in distilled water supplemented with antibiotics. The resulting debris were sedimented in alcohol and the fine debris were separated. Scanning electron microscopy analysis and particle size analysis demonstrated that the mean size of particles was 1.1 +/- 0.9 microm (range 0.2-4.2 microm). Sixty-two percent were smaller than 1.0 microm, and 85% were smaller than 2.0 microm. The particles generated had varying shapes, including angular or shard-like shapes with jagged and irregular outlines.

Cross-reference weighted least square estimates for positron emission tomography.

An efficient new method, termed as the cross-reference weighted least square estimate (WLSE) [CRWLSE], is proposed to integrate the incomplete local smoothness information to improve the reconstruction of positron emission tomography (PET) images in the presence of accidental coincidence events and attenuation. The algebraic reconstruction technique (ART) is applied to this new estimate and the convergence is proved. This numerical technique is based on row operations. The computational complexity is only linear in the sizes of pixels and detector tubes. Hence, it is efficient in storage and computation for a large and sparse system. Moreover, the easy incorporation of range limits and spatially variant penalty will not deprive the efficiency. All this makes the new method practically applicable. An automatically data-driven selection method for this new estimate based on the generalized cross validation is also studied. The Monte Carlo studies demonstrate the advantages of this new method.

Failure of total hip arthroplasty with a precoated prosthesis. 4- to 11-year results.

A series of early femoral component failures prompted a detailed retrospective clinical and radiographic review of 176 hybrid cemented total hip arthroplasties using a polymethyl-methacrylate coated femoral prosthesis. All surgeries were performed using third generation cement techniques. Average length of followup was 6.3 years (range, 3-12 years). Twenty-one patients died, and one underwent revision surgery because of sepsis. Of the remaining 154 total hip arthroplasties, 23 (15%) of the femoral components failed (21 revised, two definitely loose). The average time to revision was 3.9 years. None of the acetabular components failed. Comparison between the failure and nonfailure groups revealed that poor cement mantles (Grades C or D) with distal cement mantle deficiencies were statistically significant predictors of femoral failure. The most common mechanism of failure was progressive, circumferential cement-bone interface osteolysis with relative preservation of the cement-metal interface. Debonding of the cement column from the prosthesis was a late finding and occurred in only 45% of failed cases. Incorporating the techniques of centralization and centrifugation significantly improved clinical results. Strengthening of the cement-prosthesis interface may magnify the deleterious effects of a poor cement mantle and predisposes the cement-bone interface to failure.

A study of motor and sensory evoked potentials in chronic cauda equina compression of the dog.

Previous experimental studies have shown the effects of acute compression of the spinal cord and peripheral nerve roots. Recently, however, a few studies of chronic compression of the cauda equina in animal models have been reported. The purpose of this study was to determine the long-term electrophysiologic changes resulting from chronic compression of the cauda equina in dogs. An animal model of lumbar spinal stenosis was prepared according to Delamarter's method. Four experimental groups, each containing six dogs, were studied. One group underwent only laminectomy of the sixth and seventh lumbar vertebrae; these animals served as controls. In the three other groups, a laminectomy was performed and the cauda equina was constricted by 25%, 50%, and 75%, respectively, to produce chronic compression. Weekly neurologic examinations were carried out, and the neurologic deficits were graded using a modified Tarlov system. Sensory, and motor evoked potentials were recorded preoperatively, immediately after constriction, and at 2 weeks and 1, 2, and 3 months postoperatively. The animals in the control group showed no changes in sensory or motor evoked potentials. The dogs in which the cauda equina had been constricted by 25% showed no neurologic deficits and only mild changes in sensory and motor evoked potentials. The dogs in which the cauda equina had been constricted by 50% showed mild initial motor weakness, and major changes in the evoked potentials. The dogs in which the cauda equina had been constricted by 75% showed significant weakness, paralysis of the tail, and urinary incontinence; all dogs were partially recovered by the 3rd month, but all still showed neurogenic changes in the evoked potentials. Sensory and motor evoked potentials revealed neurologic abnormalities before the appearance of neurologic signs and symptoms. Constriction of more than 50% was the critical point that resulted in complete loss or reduction of the evoked potentials and in neurologic deficits. Dogs in which motor and sensory evoked potentials recovered also showed gradual disappearance of neurologic symptoms and signs. Recovery of motor evoked potentials in particular was associated with complete disappearance of neurologic symptoms and signs. For accurate prognosis in cases of chronic cauda equina compression, a combined diagnostic study of sensory and motor evoked potentials is recommended.

Electrodiagnostic and histologic changes of graded caudal compression on cauda equina in dog.

STUDY DESIGN: An animal model of lumbar spinal stenosis, in which the pathophysiology of this condition could be examined, was retrieved according to Delamarter's method. OBJECTIVES: The purpose of this study was to develop a reproducible animal model of lumbar spinal stenosis to further understanding of the long-term electrophysiologic changes, and to detect prognostic indices of the long-term anatomic and physiologic status of chronic compression of the cauda equina. SUMMARY OF BACKGROUND DATA: Somatosensory-evoked potentials and bulbocavernosus reflexes revealed abnormalities before neurologic signs and symptoms appeared. If delayed somatosensory-evoked potentials and bulbocavernosus reflexes were recovered with the lapse of time, neurologic findings showed gradual recovery. The loss of somatosensory-evoked potentials, bulbocavernosus reflexes, and neurologic, histological abnormalities occurred at 50% constriction of the cauda equina; at the same time, that was the critical point of possible recovery. METHODS: Four experimental groups, each containing six dogs, were studied. One group had a laminectomy of the sixth and seventh lumbar vertebrae only; these animals served as controls. In the three other groups, a laminectomy was performed, and the cauda equina was constricted by 25%, 50%, or 75% to produce chronic compression according to Delamarter's method. RESULTS: Somatosensory-evoked potentials and bulbocavernosus reflexes revealed neurologic abnormalities before the appearance of neurological signs and symptoms. Constriction of more than 50% was the critical point; it resulted in loss of evoked potentials, reflexes, neurologic deficits, and histological abnormalities. CONCLUSION: To accurately forecast prognosis of chronic cauda equina compression, the combined diagnostic study of somatosensory-evoked potential with bulbocavernosus reflex is recommended.

The Orthofix external fixator for fractures of long bones.

The Orthofix external fixator was used to treat 112 fractures of the long bones in 101 patients, and 22 patients with infected nonunions. Our results compared favourably with those reported in other series where external fixation was used. The overall rate of uncomplicated union was 69.6% with 24.1% of patients requiring a further operation. The overall incidence of nonunion (30.4%) was due to the relatively large number of severe open fractures in the series. The apparatus was simple to apply, and safe and effective in practice. We recommend its use for the primary treatment of open and segmental fractures, and for infected nonunion.

Effect of sodium hyaluronate on prevention of osteoarthritis.

The changes in the surface of articular cartilage of femoral condyle from rabbits were evaluated after degenerative changes were made by the technique advocated by Hulth. The medial collateral and both cruciate ligaments were excised, and a medial menisectomy was done. Then the right knee joint was injected with 1 ml of Na-hyaluronate gel every two weeks. The animals were sacrificed at two, four, six, eight, or sixteen weeks postoperatively. After sacrifice, the medial femoral condyle was excised and prepared for the light microscopic and scanning electron microscopic study. At eight to sixteen weeks, there were chondrocyte clones with clefts to the radial zone and increased loss of the height of articular cartilage on the control side; but, on the experimental side there was a significant delay and lessening of the arthritic response. The biocompatibility and the protective effect of joint degeneration of this device make this material a valuable adjuvant in the treatment of osteoarthritis and the traumatized joints.

Deltoid sensory flap.

Eight patients were treated using the deltoid sensory flap for soft-tissue injury of the extremities. The results were one-stage reconstructions of soft tissue extremity injuries. Protective sensibility was provided to the reconstructed area; there was no limitation of motion of the shoulder after the procedure; and primary closure of the donor site was feasible. The advantages of the deltoid sensory flap exceed those of other reconstructive procedures that are used in areas where sensibility is essential.

Clinical significance of the immunological tests in rheumatoid arthritis.

Of the many theoretical causes of rheumatoid arthritis(RA), the most widely held theory is the autoimmune mechanism. In order to clarify the clinical significance of the immunological tests in RA, we studied immunoglobulin and complement levels in sera and synovial fluids of 118 RA patients and the following results were obtained. 1) The levels of immunoglobulins were elevated in both serum and synovial fluid and this was more prominent in the seropositive cases than the seronegative ones. 2) The levels of C3 component were decreased in both serum and synovial fluid, while those of C4 were decreased only in synovial fluid. Serum C3 and C4 component levels were more decreased in the seropositive cases than the seronegative ones. 3) The immunoglobulin levels in serum (IgG, IgM and IgA) and synovial fluid (IgG and IgA) and the levels of C3, C4 component in serum were well correlated with the clinical forms of rheumatoid arthritis. 4) The IgA level in serum and IgM level in synovial fluid were more increased in the exacerbated cases than the chronic ones. 5) Serum IgG level was decreased after steroid medication over one month.

Molecular analysis of membrane immunoglobulin-negative variants.

The mouse B-cell lymphoma WEHI 279.1 is a tumor which synthesizes both membrane and secreted immunoglobulin M (IgM). We have immunoselected variants which fail to express the membrane form (mIgM-); the most frequently isolated phenotype is a complete loss of both membrane expression and synthesis of the mu heavy chain within the cells. We have chosen four of these mIgM- mutants for detailed molecular investigation. One of these has suffered a large deletion which covers the region of chromosome 12 containing the expressed mu gene, but three have no detectable changes in the DNA arrangement of the mu gene. All of the mutants, including the deletion mutant, synthesize 10-30% of the wild-type level of cytoplasmic mu RNA; however, none is the appropriate size for membrane mu (mu m) or secreted mu (mu s) message. Based on our studies of the deletion mutant, which retains its nonproductively arranged allele, at least some of these RNAs may be 'sterile' transcripts from the nonproductively arranged allele. However, if all of these mRNAs derive from the other allele, they represent a substantial elevation of these sterile messages relative to the wild-type level. Furthermore, the three nondeletion mutants transcribe mu RNA at a level indistinguishable from the wild type. It is likely that their defects lie in the stability, processing, or transport of the mu RNA within the nucleus. Somatic cell hybrids between P3X and the IgM- variants produced mostly mIgM- hybrids. However, a few mIgM+ hybrids were produced, suggesting that the mu- defects may be partly complemented by the P3X fusion partner.

Structure of acid protease from Endothia parasitica in cross-linked form at 2.45-A resolution.

The structure of acid protease from Endothia parasitica in strongly cross-linked form is compared with that of the untreated protein at 2.45-a resolution. The only observed conformation change introduced by the cross-linking reaction is at the N terminal. Otherwise the two main chain structures are essentially identical. Approximately 2 molecules of the inhibitor, 1,2-epoxy-3-(p-nitrophenoxy)propane, are found to be incorporated into each protein molecule. They are covalently bound to the two aspartic residues at the active center.