RGS12 Drives Macrophage Activation and Osteoclastogenesis in Periodontitis.

Periodontitis is a complex inflammatory disease affecting the supporting structures of teeth and is associated with systemic inflammatory disorders. Regulator of G-protein signaling 12 (RGS12), the largest protein in the RGS protein family, plays a crucial role in the development of inflammation and bone remodeling. However, the role and mechanism(s) by which RGS12 may regulate periodontitis have not been elucidated. Here, we showed that ablation of RGS12 in Mx1+ hematopoietic cells blocked bone loss in the ligature-induced periodontitis model, as evidenced morphometrically and by micro-computed tomography analysis of the alveolar bone. Moreover, hematopoietic cell-specific deletion of RGS12 inhibited osteoclast formation and activity as well as the production of inflammatory cytokines such as IL1ß, IL6, and TNFα in the diseased periodontal tissue. In the in vitro experiments, we found that the overexpression of RGS12 promoted the reprogramming of macrophages to the proinflammatory M1 type, but not the anti-inflammatory M2 type, and enhanced the ability of macrophages for migration. Conversely, knockdown of RGS12 in macrophages inhibited the production of inflammatory cytokines and migration of macrophages in response to lipopolysaccharide stimulation. Our results demonstrate for the first time that inhibition of RGS12 in macrophages is a promising therapeutic target for the treatment of periodontitis.

Root coverage by coronally advanced flap with connective tissue graft and/or enamel matrix derivative: a meta-analysis.

BACKGROUND AND OBJECTIVE: Previous systematic reviews have reported that the use of a coronally advanced flap (CAF) combined with a connective tissue graft (CTG) or enamel matrix derivative (EMD) is more likely to achieve complete root coverage (CRC) than other modalities. However, the details of periodontal parameters and comparisons among a variety of combinations of CAF with CTG and/or EMD are left to be investigated. This study aimed to analyze the differences in periodontal parameters between these treatment modalities. MATERIAL AND METHODS: A literature search was performed using the Cochrane library and MEDLINE (PubMed) for studies focused on the treatment of gingival recession (Miller Class I, II and III) with CAF alone or combined with CTG, EMD or both up to December 2011. Randomized controlled clinical trials with a follow-up duration ≥ 6 mo were included. The outcome analysis included changes in periodontal probing depth (PPD), clinical attachment level, recession depth (RED) and keratinized tissue width (KTW). RESULTS: Thirteen randomized controlled clinical trials, including 529 Miller Class I-III defects from 321 patients were included. For an increase in KTW, CAF + CTG significantly improved more than CAF alone. CAF + EMD also gained more KTW than CAF alone. EMD reduced PPD, however, a significant difference was not found. Furthermore, the effects on changes of RED and clinical attachment level were not identified in the study. CONCLUSION: When combined with CAF, CTG contributed more in the increase of KTW, while EMD seemed helpful for wound healing by its potential in PPD reduction. However, further research is needed to clarify the effects on changes in RED and clinical attachment level.

Computational hemodynamic modeling based on transesophageal echocardiographic imaging.

We address the problem of hemodynamic computational modeling in the left heart complex. The novelty of our approach lies in the exploitation of prior patient specific data resulting from image analysis of Transesophageal Echocardiographic Imagery (TEE). Kinematic and anatomical information in the form of left heart chambers and valve boundaries is recovered through a level-set-based user-in-the-loop segmentation on 2D TEE. The resulting boundaries in the TEE sequence are then interpolated to prescribe the motion displacements in a computational fluid dynamics (CFD) model implemented using Finite Element Modeling (FEM) applied on Arbitrary Lagrangian-Eulerian (ALE) meshes. Experimental results are presented.

Prolongation of cardiac graft survival with anti-CD4Ig plus hCTLA4Ig in primates.

BACKGROUND: The aim of this study was to determine whether the use of combined immunotherapy with a brief course of humanized anti-CD4Ig and hCTLA4Ig would prolong heterotopic cardiac allograft survival in primates (rhesus monkeys). This model was based on work in "high responder" rats where a brief course of depletive anti-CD4mAb plus hCTLA4Ig was successful in inducing transplantation tolerance. METHODS: Heterotopic cardiac transplants were performed in rhesus recipients. Donor/recipient pairs between groups were confirmed to be reactive prior to transplantation by MLR matching. Humanized anti-CD4Ig, a recently developed anti-CD4mAb, was given at a dose of 20 mg/kg i.v. on days -3, -2, -1, and 0. hCTLA4Ig was administered at 6 mg/kg/dose i.v. on days 0 and 2 for the first recipient and days 0, 2, 4, and 6 for the second recipient. No further immunosuppression was administered. The treated (n = 2) or untreated (n = 5) recipients were followed for graft function by daily palpitation. RESULTS: Treatment with anti-CD4Ig plus hCTLA4Ig resulted in a significant prolongation of heart graft survival (42 days for the first recipient and 52 days for the second recipient) compared to untreated recipients (7 days x 4, 11 days x 1). FACS analysis demonstrated CD4 depletion of anti-CD4 treated animals to <2% on posttransplant day 1. The CD4+ T cells gradually repopulated to 50-70% pretransplant levels just prior to rejection. No adverse responses (fever, tachypnea, tachycardia, infections) were observed. CONCLUSIONS: These are the first results demonstrating that a brief course of combined specific induction immunotherapy with humanized anti-CD4Ig plus hCTLA4Ig, in the absence of adjuvant posttransplant immunosuppression, was well tolerated and resulted in marked prolongation of cardiac allograft survival in primates.

Pleural disease in patients undergoing lung transplantation for cystic fibrosis.

Cystic fibrosis (CF) is associated with varying degrees of pleural inflammatory reaction that occurs as a result of chronic pulmonary infections and intervention to pleural space. The amount of pleural reaction is associated with the difficulty involved when performing the pneumonectomy at the time of lung replacement. The aim of this study is to identify possible pre-transplantation parameters that may predict the extent of pleural adhesion density. The charts of the 32 CF patients who underwent lung transplantation were reviewed. The degree of pleural adhesions was graded as none, minimal, moderate or severe, by extensive retrospective chart review of the operative and pathology reports. Available Brasfield radiographic scores, chest computerized tomographic (CT) scan scores, and pulmonary function test results were correlated to the pleural density grades. CT scans were scored by one radiologist as none, mild focal, moderate focal, diffuse mild or severe pleural disease. The presence of severe adhesions was associated with lower diffusion capacity corrected for volume (DL(CO)/VA) (p=0.0022) and older age (p<0.05) at the time of transplant. The typical radiographic and pulmonary function findings of airway obstruction, parenchymal nodularity and air trapping did not correlate with pleural adhesion density. The eleven patients with severe pleural adhesions had a longer ICU course and remained intubated longer than the thirteen patients with none or minimal adhesions. The extent of severe adhesions associated with CF cannot be predicted by preoperative Brasfield radiographic scores of parenchymal disease or spirometry data. However, chest CT imaging and DL(CO)/VA measurements may be useful in predicting the extent of pleural adhesions and the degree of dissection difficulty associated with the pneumonectomies for lung transplantation in the CF recipients.

Perinatal induction of immunotolerance to cardiac and pulmonary allografts.

OBJECTIVES: Tolerance appears to be more easily induced in the fetus before full immunocompetence is established, but elucidation of this process is needed. A model of perinatal tolerance induction to neonatal skin allografts followed by cardiac and pulmonary allografts is described. METHODS: Sixty Lewis (RT11) rat fetuses were inoculated intraperitoneally at 18 days gestation with 1 x 10(7) ACI (RT1a) rat fetal liver cells (group I); 20 Lewis fetuses were inoculated with 2 x 10(7) ACI fetal liver cells (Group II). control groups consisted of Lewis fetuses inoculated with saline solution (n = 25, group III) and fetuses that were not inoculated (n = 25, group IV). Twenty-five of the 50 surviving group I rats received ACI skin (< 24 hours old) and heart (8 to 10 weeks old) allografts (group IA); the remaining 25 rats received only ACI heart grafts (group IB). Groups II, III, and IV received ACI skin and cardiac allografts. Recipients tolerant to both skin and cardiac grafts received orthotopic ACI lung grafts and third-party skin grafts. Tolerance was indicated by graft survival for more than 100 days. Limiting dilution and flow cytometric analyses were performed. RESULTS: Abortion rates in groups I, II, III, and IV were 17% (10/60), 65% (13/20), 8% (2/25), and 4% (1/25), respectively. Specific tolerance to skin, cardiac, and lung allografts was observed in seven of 25 group IA recipients (28%) and seven of seven group II recipients (100%) compared with no tolerance in any group IB, III, or IV recipients (p = 0.03, chi 2 test). A 100-fold reduction of precursor cytotoxic T lymphocytes and significant splenocyte and bone marrow chimerism in tolerant versus nontolerant rats were noted (p = 0.0001, Student's t test). CONCLUSIONS: Using donor-strain fetal liver cells and neonatal skin grafts, we achieved higher frequencies of tolerance to solid organ grafts in adulthood with lower cell inocula and abortion rates than previously described. Chimerism and depressed precursor cytotoxic T lymphocyte frequencies in tolerant recipients suggest that hematopoietic stem cell engraftment and clonal deletion/anergy are involved in induction of perinatal tolerance.

A rodent model of in utero chimeric tolerance induction.

BACKGROUND: In utero tolerance induction has potential application in pediatric heart transplantation. Immunotolerance appears to be more easily induced in the fetus before full immunocompetence is established; however, the mechanisms behind this phenomenon are still undefined. METHODS: One hundred thirty Lewis (RT1l) rat fetuses from 10 litters were inoculated intraperitoneally at 18 days gestation with 1 x 10(7) ACI (RT1a) rat fetal liver cells. Fifty of the 100 viable neonates successfully brought to term were grafted with neonatal ACI skin within 24 hours of birth and heterotopic ACI hearts at 8 to 10 weeks of age (group 1A); the remaining 50 neonates only received heterotopic ACI heart grafts at 8 to 10 weeks (group 1B). Control groups consisted of 50 Lewis fetuses (five litters) inoculated in utero with phosphate-buffered saline solution (group 2) and 50 Lewis fetuses (five litters) that received no inoculum (group 3); all of these surviving progeny received both neonatal ACI skin and adult ACI cardiac allografts. Skin and cardiac grafts were monitored by daily visual inspection and palpation, respectively. Limiting dilution analysis was performed among all groups to assess precursor cytotoxic lymphocyte frequencies. Likewise, peripheral blood lymphocyte and splenocyte populations were analyzed with flow cytometry to detect allogeneic chimerism. RESULTS: Abortion rates among groups 1, 2, and 3 were 23% (30/130 abortions), 10% (5/50 abortions), and 6% (3/50 abortions), respectively. Tolerance to both ACI skin and cardiac allografts was induced in 14 of the 50 group 1A Lewis recipients (28%). Tolerance was not achieved in any of the recipients in groups 1B, 2, or 3. Limiting dilution analysis among all groups revealed a marked reduction of precursor cytotoxic T-lymphocytes in tolerant allograft recipients compared with recipients in the other groups. Flow cytometry detected significant splenocyte chimerism among tolerant rats; significant peripheral blood chimerism was not noted. CONCLUSIONS: We describe allogeneic tolerance induction in utero to both rat skin and heart tissue by use of donor-strain fetal liver cells. Compared with previous studies with adult splenocytes as the tolerogen, we achieved a higher frequency of tolerance with a markedly lower cell inoculum and lower abortion rate. Allogeneic chimerism was noted in the tolerant recipients, suggesting hematopoietic stem cell engraftment. Cytotoxic T-lymphocyte precursor frequencies were markedly depressed in tolerant animals. Interestingly, both donor-strain fetal liver cells and neonatal skin grafts were required to induce tolerance. These data suggest a period of hematopoietic "education" during and shortly after hematopoietic stem cell engraftment.

Tolerance to cardiac allografts induced in utero with fetal liver cells.

BACKGROUND: Induction of immunological tolerance in utero has potential application in pediatric cardiac transplantation. We describe an inexpensive, reproducible, and well-characterized model of allogeneic tolerance induction in utero using donorstrain fetal liver cells. METHODS AND RESULTS: Each of 9 Lewis (LEW, RTl1) rat fetuses in one litter (group 1) and 10 LEW fetuses in another litter (group 2) were inoculated intraperitoneally at 17 to 18 days of gestation with 1 x 10(6) ACI (RTla) rat fetal liver cells. Ten LEW fetuses in a third litter inoculated with PBS (group 3) and 10 LEW noninoculated fetuses in a fourth litter (group 4) served as controls. The LEW rats were brought to term, and groups 1, 3, and 4 were grafted with neonatal ACI skin within 24 hours of birth and with heterotopic ACI hearts at 8 to 10 weeks of age; group 2 rats received only an ACI heart graft at 8 to 10 weeks. Skin and cardiac grafts were monitored by daily visual inspection and palpation, respectively. Peripheral blood lymphocyte (PBL) populations in all LEW recipients were analyzed with flow cytometry. All LEW fetuses survived to term and developed normally. The ACI skin and cardiac allografts on 3 of the 9 LEW rats in group 1 are viable to date (skin, > 170 days; cardiac, > 100 days). The remaining 6 recipients of this group and all animals in groups 2, 3, and 4 rejected their skin and cardiac grafts by postgrafting day 7. Significant PBL chimerism (1.57%) was observed in only 1 tolerant rat. CONCLUSIONS: We describe allogeneic tolerance induction in utero to both rat skin and cardiac tissue with donor-strain fetal liver cells. Compared with previous studies using adult splenocytes as the tolerogen, we achieved a higher frequency of tolerance with a markedly lower cell inoculum and no abortions. Interestingly, both donor-strain fetal liver cells and neonatal skin grafts were required to maintain tolerance into adulthood. Immunocompetence sufficient to reject allografts was noted in neonates, and PBL chimerism was not prominent in tolerant recipients.

Leflunomide prolongs pulmonary allograft and xenograft survival.

BACKGROUND: Leflunomide, an isoxazole derivative, has been shown to effectively prolong rodent allograft and cardiac xenograft survival. In vitro studies suggest that leflunomide inhibits the production of donor-specific antibodies and is capable of blocking both T- and B-cell proliferation. In light of the significant role that humoral immunity is believed to play in chronic pulmonary allograft rejection as well as hyperacute and accelerated acute xenograft rejection, we examined the efficacy of leflunomide in prolonging pulmonary allografts and xenografts and its effect on donor-specific antibody production. METHODS: Lungs from Brown Norway rats or Golden Syrian hamsters were orthotopically transplanted into Lewis rat recipients. Allograft recipients were treated daily for 14 days with vehicle, leflunomide (15 mg/kg/day orally), or cyclosporine (7.5 mg/kg/day orally) starting on the day of grafting (day 0). In xenograft recipients, leflunomide (20 mg/kg/day orally) or cyclosporine (7.5 mg/kg/day orally) treatment initiated on day 0 was continued until complete graft rejection; the leflunomide dosage was reduced to 10 mg/kg/day after day 14 because of weight loss and leukopenia. Graft viability was assessed with chest radiography in conjunction with open lung biopsies. Toxicity was monitored with body weight measurements, complete blood counts, and serum chemistries. Flow cytometric analysis of serum samples taken from graft recipients on day 7 was used to measure donor-specific immunoglobulin M and immunoglobulin G antibody titers. RESULTS: Allograft and xenograft control animals receiving vehicle yielded graft survival times of 6.0 +/- 0.0 and 5.4 +/- 0.6 days, respectively. Although xenograft recipients treated with cyclosporine (7.5 mg/kg/day orally) showed no significant graft prolongation, pulmonary allograft survival in recipients receiving cyclosporine alone was significantly prolonged to 28.2 +/- 0.7 days. Leflunomide-treated allograft (15 mg/kg/day orally) and xenograft (20 mg/kg/day orally) recipients displayed significant graft prolongation to 28.2 +/- 0.7 days and 15.8 +/- 3.3 days, respectively. Cyclosporine (7.5 mg/kg/day orally) enhanced the effect of leflunomide (20 mg/kg/day orally) in xenograft recipients with a mean graft survival time of 36.0 +/- 3.0 days achieved when both drugs were administered concomitantly. Cyclosporine significantly suppressed donor-specific immunoglobulin G antibody titers in both pulmonary allograft and xenograft recipients while not affecting immunoglobulin M levels. Leflunomide markedly suppressed both immunoglobulin G and immunoglobulin M donor-specific antibody titers in allograft and xenograft recipients. Except for mild leukopenia and anemia, both cyclosporine- and leflunomide-treated allograft recipients showed no evidence of toxic side effects after 14 days of therapy. However, leflunomide-treated xenograft recipients displayed significant weight loss, anemia, and leukopenia after 14 days of treatment with one death in each treatment group.

Primary cardiac lymphoma treated with orthotopic heart transplantation: a case report.

Primary lymphoma of the heart is an extremely rare tumor. It is associated with a high mortality rate because of the advanced stage of myocardial involvement at initial presentation. Conventional surgical and medical treatments have not met with much success. This article reports the first case of primary cardiac lymphoma treated with orthotopic heart transplantation. The patient had hemodynamically significant severe acute rejection, neutropenic sepsis, and tumor recurrence during the late postoperative period, illustrating the difficulties associated with concomitant immunosuppression and tumor chemotherapy. Unfortunately, the patient died after a period of remission. Our approach to the integration of immunosuppression with chemotherapy, posttransplantation follow-up, and complications is discussed.

The immunopharmacology of immunosuppression by 15-deoxyspergualin.

We have used two murine bioassays, a nonprimarily vascularized heart transplant model and a host-versus-graft (HvG) popliteal lymph node (PLN) hyperplasia assay, to study the novel immunosuppressant, 15-deoxyspergualin (DSG). Using these methods, we investigated DSG's immunosuppressive potency, efficacy, and mechanisms of action. Dose-response studies showed that prolongation of heart allograft survival by DSG was dose dependent with an ED50 +/- SD of 1.45 +/- 0.39 mg/kg/day and that DSG was nearly seven times more potent than cyclosporine. Low maintenance doses of 0.25 or 1.0 mg/kg/day of DSG that followed an initial 14-day course of 5.0 mg/kg/day DSG enabled heart allografts to survive for more than 200 days without recipient weight loss or other signs of overt toxicity. When used as treatment for ongoing acute rejection, DSG prolonged graft survival. Although a 30-day course of 5.0 mg/kg/day of DSG caused significant but reversible body-weight loss, no overt, gross, or histopathologic evidence of significant tissue toxicity was observed in mice treated with 5.0 mg/kg/day DSG for 13 consecutive days. Frequent, intermittent administration of DSG was more immunosuppressive than less frequently administered high doses of DSG, but continuous infusion did not augment drug efficacy or reduce its toxicity. Isobologram analysis of graft survival in recipients treated with both DSG and CsA showed that this drug combination produced synergistic immunosuppression. In contrast to DSG's efficacy when administered posttransplant, the survival of grafts in recipients that were treated with DSG for 30 days posttransplant was only minimally prolonged. When recipients were sensitized by primary grafts, administration of DSG only during the period of sensitization or only immediately after implantation of secondary grafts failed to prevent accelerated rejection. If, however, graft recipients were treated with DSG both before and after implantation of secondary grafts, accelerated graft rejection was prevented. DSG induced partial alloantigen-specific unresponsiveness, since in DSG-treated C3H recipients of primary BALB/c grafts, secondary BALB/c grafts survived longer than third-party C57BL/6 secondary grafts. A dose of DSG that prolonged graft survival maximally did not suppress the in vivo lymphoproliferative response to alloantigen in the PLN assay. In contrast, doses of CsA that prolonged graft survival minimally suppressed the HVG response significantly. Thus, these studies showed that DSG was a more potent and effective immunosuppressant than CsA, and that DSG treatment prolonged graft survival substantially without apparent toxicity. Furthermore, unlike CsA, a dose of DSG that prolonged heart allograft survival did not suppress alloantigen-stimulated lymphoproliferation in vivo.(ABSTRACT TRUNCATED AT 400 WORDS)