IFN-γ directly inhibits TNF-α-induced osteoclastogenesis in vitro and in vivo and induces apoptosis mediated by Fas/Fas ligand interactions

Cytokines secreted by T cells play a pivotal role in inflammatory bone destruction. Tumor necrosis factor-α (TNF-α) is a major proinflammatory cytokine produced by macrophages following T cell activation, and directly promotes osteoclast differentiation resulting in accelerated bone resorption. Interferon-γ (IFN-γ) attenuates RANKL-initiated cellular signals through osteoclast formation and counterbalances aberrant bone resorption. With respect to this crosstalk during osteoclastogenesis, the direct interruption of IFN-γ in TNF-α-induced osteoclast formation still requires elucidation. We have demonstrated that IFN-γ directly inhibits osteoclastogenesis induced by TNF-α stimulation and accelerates apoptosis mediated by Fas/Fas ligand signals. There were a decreased number of osteoclasts and reduced mRNA levels encoding Nfatc1 in cultured bone marrow macrophages. Apoptotic responses of cultured cells were observed, with accelerated nuclear fragmentation in osteoclast precursor cells and increased FasL mRNA levels in bone marrow cells stimulated with TNF-α evident. IFN-γ reduced the level of osteoclastogenesis in response to TNF-α treatment in vivo. IFN-γ inhibited TNF-α-induced osteoclastogenesis in mice with T cells that had been exposed to anti-CD4 and -CD8 antibodies. These results provide evidence that IFN-γ directly inhibits osteoclastogenesis and induces cells apoptosis by Fas/FasL signals, leading to the indirect regulation of bone resorption, which is required for protective roles in bone destruction at an inflammation site.     

Sensitivity surveillance of Pseudomonas aeruginosa isolates for several antibacterial agents in Gifu and Aichi prefecture (2008)

We investigated the susceptibility to antibacterial agents of 334 strains of Pseudomonas aeruginosa isolated from medical facilities in Gifu and Aichi prefectures from May to September 2008. For the beta-lactams, meropenem (MEPM) and doripenem (DRPM) gave the lowest MIC50 at 0.5 microg/mL, and tazobactam/piperacillin (TAZ/PIPC) gave the highest susceptible rate of the breakpoint by Clinical and Laboratory Standards Institute (CLSI) at 93.1%. For the quinolones, ciprofloxacin (CPFX) gave the lowest MIC50 at 0.25 microg/mL, followed by pazufloxacin (PZFX) at 0.5 microg/mL, and levofloxacin (LVFX) at 1 microg/mL, and susceptible rate was 76.0% for CPFX and 73.4% for LVFX. Susceptible rates to amikacin (AMK) and tobramycin (TOB) of aminoglycocides and colistin (CL) of polypeptides were 98.2%, 97.6% and 96.4%. In 334 strains, IMP-1 MBL producing P. aeruginosa was 1 strain, and the strain showed resistance to all antibacterial agents except AMK and CL used in this study. The strains isolated from urine were lower susceptible rate in comparison with those from sputum, notably the susceptible rate to CPFX from urine was less over 30% than those from sputum. Because the results of the susceptibility test against P. aeruginosa were different in each area, it is important for us to pay attention to the susceptibility to antibacterial agents and the emergence of resistance in the clinical strains through continuous susceptibility surveillance.     

Biomechanical evaluation of segmental instability in degenerative lumbar spondylolisthesis

Here we investigated the biomechanical properties of spinal segments in patients with degenerative lumbar spondylolisthesis (DLS) using a novel intraoperative measurement system. The measurement system comprised spinous process holders, a motion generator, a load cell, an optical displacement transducer, and a computer. Cyclic displacement of the holders produced flexion-extension of the segment with all ligamentous structures intact. Stiffness, absorption energy (AE), and neutral zone (NZ) were determined from the load-deformation data. Forty-one patients with DLS (M/F = 15/26, mean age 68.6 years; Group D) were studied. Adjacent segments with normal discs in six patients (M/F = 3/3, mean age 35 years) were included as a control group (Group N). Flexion stiffness was significantly lower in Group D than in Group N. The NZ, however, was significantly greater in Group D than in Group N. Thus, compared to normal segments, spinal segments with DLS had a lower flexion stiffness and a higher NZ. NZs in Group D were, however, widely distributed compared to those in Group N that showed NZ <2 mm/N in all cases, suggesting that the segment with DLS is not always unstable and that the segments with NZ >2 mm/N can be considered as unstable. A patent application for the intraoperative measurement system has been submitted.     

Three-dimensional ultrasonography before minimally invasive focused parathyroidectomy: The importance of coronal images

Purpose  To evaluate the usefulness of three-dimensional (3D) ultrasonography (US) as a noninvasive preoperative localization procedure before performing minimally invasive focused parathyroidectomy in patients with primary hyperparathyroidism (pHPT). Methods  Seventy-six patients with a solitary adenoma detected by US underwent minimally invasive focused parathyroidectomy. The value of 3D US was assessed by dividing patients into a 2D group and a 3D group. Age, the preoperative serum intact parathyroid hormone (PTH) level, operative time, length of skin incision, and weight of the resected specimen were compared between the groups, and multivariate analysis of the operative time was performed. Results  There were no significant differences between the 2D group and the 3D group in age, the preoperative intact PTH level, length of skin incision, or weight of the resected specimen, but the mean operative time was significantly longer in the 2D group (P < 0.01). Multivariate analysis revealed that 3D US and the weight of the resected specimen were correlated with the operative time (P < 0.05). Conclusion  The coronal images obtained by 3D US assist in the precise localization of parathyroid masses in patients with pHPT undergoing minimally invasive focused parathyroidectomy for a solitary adenoma.     

In vitro short-term platelet adhesion on various metals

The in vitro short-term platelet adhesion on various metals, as accelerated by the addition of Ca²⁺, was evaluated in this study. Metals used for medical devices [an austenitic stainless steel, a cobalt (Co)-chromium (Cr)-molybdenum (Mo) alloy, a titanium (Ti)-6 aluminum (Al)-4 vanadium (V) alloy, a Ti-6Al-7 niobium (Nb) alloy, a Tinickel (Ni) alloy, and commercially pure Ti] were immersed into a platelet-rich plasma solution for 5 or 20 min, and platelet adhesion and aggregation on the surfaces were observed using a scanning electron microscope. The platelet adhesion level on each metal after 5 min of immersion in a platelet-rich plasma solution was the smallest in this order: stainless steel ≤ Co-Cr-Mo alloy < Ti-6Al-4V alloy < Ti-6Al-7Nb alloy < Ti-Ni alloy = Ti. The levels after 5 min of immersion were almost the same as those after 20 min of immersion. Platelet adhesion was minimal on stainless steel and Co-Cr-Mo alloy, which have a Cr₂O₃-containing passive surface oxide film, but was accelerated on Ti and Ti alloys having a TiO₂-contanining film. A Cr₂O₃-containing oxide film has a lower relative permittivity than a TiO₂-contanining film; it thus supports a larger electrostatic force than the latter, adsorbs more albumins, which work as inhibitory proteins, and inhibits platelet aggregation. Therefore, platelet adhesion and aggregation are controlled by the composition of the surface oxide film on a metal due to the relative permittivity of the metal, which influences the amount of adsorbed proteins.     

The combination therapy with alfacalcidol and risedronate improves the mechanical property in lumbar spine by affecting the material properties in an ovariectomized rat model of osteoporosis

Background

The to date evidence for a dose-response relationship between physical workload and the development of lumbar disc diseases is limited. We therefore investigated the possible etiologic relevance of cumulative occupational lumbar load to lumbar disc diseases in a multi-center case-control study.

Methods

In four study regions in Germany (Frankfurt/Main, Freiburg, Halle/Saale, Regensburg), patients seeking medical care for pain associated with clinically and radiologically verified lumbar disc herniation (286 males, 278 females) or symptomatic lumbar disc narrowing (145 males, 206 females) were prospectively recruited. Population control subjects (453 males and 448 females) were drawn from the regional population registers. Cases and control subjects were between 25 and 70 years of age. In a structured personal interview, a complete occupational history was elicited to identify subjects with certain minimum workloads. On the basis of job task-specific supplementary surveys performed by technical experts, the situational lumbar load represented by the compressive force at the lumbosacral disc was determined via biomechanical model calculations for any working situation with object handling and load-intensive postures during the total working life. For this analysis, all manual handling of objects of about 5 kilograms or more and postures with trunk inclination of 20 degrees or more are included in the calculation of cumulative lumbar load. Confounder selection was based on biologic plausibility and on the change-in-estimate criterion. Odds ratios (OR) and 95% confidence intervals (CI) were calculated separately for men and women using unconditional logistic regression analysis, adjusted for age, region, and unemployment as major life event (in males) or psychosocial strain at work (in females), respectively. To further elucidate the contribution of past physical workload to the development of lumbar disc diseases, we performed lag-time analyses.

Results

We found a positive dose-response relationship between cumulative occupational lumbar load and lumbar disc herniation as well as lumbar disc narrowing among men and women. Even past lumbar load seems to contribute to the risk of lumbar disc disease.

Conclusion

According to our study, cumulative physical workload is related to lumbar disc diseases among men and women.     

IL-12 inhibits TNF-α induced osteoclastogenesis via a T cell-independent mechanism in vivo

It has been reported that TNF-α plays an important role in bone resorption in pathological conditions. IL-12, which is a T cell mediator, is also an important inflammatory cytokine. We previously reported that IL-12 induces apoptosis in bone marrow cells treated with TNF-α in vitro via an interaction between TNF-α-induced Fas and IL-12-induced Fas ligand (FasL), and that, as a result, osteoclastogenesis is inhibited. The purpose of this study was to investigate the effects of IL-12 on TNF-α-mediated osteoclastogenesis in vivo. We administered TNF-α with and without IL-12 into the supracalvaria in mice. The numbers of osteoclasts in the sutures in the calvaria were higher in mice administered TNF-α than in control mice not administered TNF-α. The numbers of osteoclasts in mice administered both TNF-α and IL-12 were lower than those in mice administered only TNF-α. Next, we determined the levels of mRNAs for cathepsin K and tartrate-resistant acid phosphatase (TRAP). mRNA levels were increased in mice administered TNF-α compared with control mice, but not in mice administered both TNF-α and IL-12. We also evaluated the amounts of tartrate-resistant acid phosphatase 5b (TRACP 5b) in mouse sera. The levels of TRACP 5b in mice administered TNF-α were higher than those in control mice. On the other hand, in mice administered both TNF-α and IL-12, the levels were lower than those in mice administered TNF-α alone. Fas and FasL expression levels were analyzed by real-time RT-PCR. The levels of Fas mRNA were increased in the calvaria of mice administered TNF-α compared with control mice, while those of FasL mRNAs were increased in the calvaria of mice administered IL-12. In TdT-mediated dUTP-biotin nick end-labeling (TUNEL) assays, many apoptotic cells were found in the sutures in the calvaria of mice administered both TNF-α and IL-12. IL-12 also inhibited TNF-α-induced osteoclastogenesis in mice whose T cells were blocked by anti-CD4 and anti-CD8 antibodies. These results suggest that IL-12 inhibits TNF-α-mediated osteoclastogenesis and induces apoptotic changes through an interaction between TNF-α-induced Fas and IL-12-induced FasL, in vivo, via a T cell-independent mechanism.     

Administrative Issues in Child Psychiatry

Administrative issues related to operating child and adolescent psychiatry programs or child mental health centers are substantially different than their adult counterpart programs. The increasing demands from managed care and other regulatory agencies make these programs difficult to operate. The smaller scale of these programs and the fewer existing programs make managing access to care more complicated. The administrators and clinicians in these programs have to be vigilant of legal responsibilities and reporting mandates that child practitioners and agencies that treat children need to abide by. In order to continue thriving, programs need to be efficient and fiscally viable. Issues such as building the continuum of care and finding the qualified personnel to staff these services are discussed in this article.     

The proton pumping pathway of bovine heart cytochrome c oxidase

X-ray structures of bovine heart cytochrome c oxidase have suggested that the enzyme, which reduces O(2) in a process coupled with a proton pumping process, contains a proton pumping pathway (H-pathway) composed of a hydrogen bond network and a water channel located in tandem across the enzyme. The hydrogen bond network includes the peptide bond between Tyr-440 and Ser-441, which could facilitate unidirectional proton transfer. Replacement of a possible proton-ejecting aspartate (Asp-51) at one end of the H-pathway with asparagine, using a stable bovine gene expression system, abolishes the proton pumping activity without influencing the O(2) reduction function. Blockage of either the water channel by a double mutation (Val386Leu and Met390Trp) or proton transfer through the peptide by a Ser441Pro mutation was found to abolish the proton pumping activity without impairment of the O(2) reduction activity. These results significantly strengthen the proposal that H-pathway is involved in proton pumping.