The Essential Role of Circulating Thyroglobulin in Maintaining Dominance of Natural Regulatory T Cell Function to Prevent Autoimmune Thyroiditis.

Several key findings from the late 1960s to mid-1970s regarding thyroid hormone metabolism and circulating thyroglobulin composition converged with studies pertaining to the role of T lymphocytes in autoimmune thyroiditis. These studies cemented the foundation for subsequent investigations into the existence and antigenic specificity of thymus-derived natural regulatory T cells (nTregs). These nTregs prevented the development of autoimmune thyroiditis, despite the ever-present genetic predisposition, autoantigen (thyroglobulin), and thyroglobulin-reactive T cells. Guided by the hypothalamus-pituitary-thyroid axis as a fixed set-point regulator in thyroid hormone metabolism, we used a murine model and compared at key junctures the capacity of circulating thyroglobulin level (raised by thyroid-stimulating hormone or exogenous thyroglobulin administration) to strengthen self-tolerance and resist autoimmune thyroiditis. The findings clearly demonstrated an essential role for raised circulating thyroglobulin levels in maintaining the dominance of nTreg function and inhibiting thyroid autoimmunity. Subsequent identification of thyroglobulin-specific nTregs as CD4(+)CD25(+)Foxp3(+) in the early 2000s enabled the examination of probable mechanisms of nTreg function. We observed that whenever nTreg function was perturbed by immunotherapeutic measures, opportunistic autoimmune disorders invariably surfaced. This review highlights the step-wise progression of applying insights from endocrinologic and immunologic studies to advance our understanding of the clonal balance between natural regulatory and autoreactive T cells. Moreover, we focus on how tilting the balance in favor of maintaining peripheral tolerance could be achieved. Thus, murine autoimmune thyroiditis has served as a unique model capable of closely simulating natural physiologic conditions.

An islet-specific CD8+ T cell hybridoma generated from non-obese diabetic mice recognizes insulin as an autoantigen.

Although CD8+ T cells play a major role in beta cell destruction in insulin-dependent diabetes in the non-obese diabetic mouse, the T cell autoantigen(s) recognized by such cells remains to be identified. Therefore, an islet-reactive, CD8+ T cell line was generated from islet-infiltrating cells and hybridized by fusion with a CD8+ alphabeta TCR- BW5147 thymoma. In the presence of islets, none of the 12 CD3+ CD8+ T cell hybridomas isolated secreted IL-2/IL-4 or IFNgamma but three were islet specific, as shown by activation induced cell death. Subclone 4A7.7.15 recognized only islets expressing H-2Kd, demonstrated islet-specific inhibition of proliferation and concomitant partial arrest in the G2/M phase of the cell cycle. Further analysis using a panel of cell lines, expressing H-2Kd, and transfected with the cDNA for various putative autoantigens in type 1 diabetes showed that 4A7.7.15 recognizes insulin as an antigen.

Anterior fusion of the lumbar spine. End-result study with long-term follow-up.

We reviewed the cases of fifty patients who underwent anterior lumbar-spine fusion with autogenous fibular and iliac-bone grafts and were followed for two to fifteen years. Their diagnoses were instability of the spine, degenerative disc disease, pseudarthrosis, and spondylolisthesis. Fifty-six per cent had union and 44 per cent, non-union. Those who had iliac grafts healed in an average of 2.5 years and those who had fibular grafts, in 5.2 years. The clinical result was successful in twenty-six patients (52 per cent) and unsuccessful in twenty-four patients (48 per cent). Paradoxically, about one-half of the patients with clinical successes had a non-union and one-half of the failures had union. Retrograde ejaculation (sterility) did not develop in any of the men, and a survey of world authorities on anterior spine fusion revealed only sixteen patients with the sequela of retrograde ejaculation. The incidence of that complication has been exaggerated.

Prevention and treatment of non-union of slightly displaced fractures of the lateral humeral condyle in children. An end-result study.

In a ten-year study of the healing responses of thirty-one children with fresh fractures of the lateral condyle of the humerus with less than four millimeters of displacement, there were three patterns of healing. Forty-nine per cent healed rapidly in six weeks with abundant callus and periosteal new bone. Thirty-eight per cent healed slowly over eight to twelve weeks, mostly by endosteal union with little callus. Thirteen per cent had progressive displacement of the fragment in the plaster cast and required surgery to prevent non-union. Those fractures that healed had two millimeters or less of displacement of the fragment initially. Those that did not heal had an average of three millimeters of initial displacement. Established non-unions in good position that were symptomatic while the elbow was still immature were salvaged by bone-grafting, sparing the physis of the condylar fragment. The fragment united and grew with the elbow to maturity, producing an excellent end result on long-term follow-up. When the physeal plate of the ununited condylar fragment was absent, the fragment could not grow with the elbow and the result of surgery was less satisfactory.

Sexual complications of anterior fusion of the lumbar spine.

Recently, there is renewed interest in anterior fusion for spondylolisthesis and congenital and paralytic scoliosis with pelvic obliquity. Some of the candidates are prepubertal boys. Sterility after surgery in urogenitally normal prepubertal boys will not be determined until these patients mature. A worldwide survey of 20 surgeons with 15-20 years of experience (4,500 cases) reports the frequency of sterility (retrograde ejaculation) to be 19 cases (0.42%) and impotence 20 cases (0.44%). One-fourth of the retrograde ejaculation cases resolved and became normal. Impotence is non-organic. The complication of retrograde ejaculation does not appear to be related to approach, though it was related to technique. While the complications of sterility and impotence following anterior fusion have been over-exaggerated, caution and informed consent from adult males and parents of prepubertal male children is advisable.

The third step of total autologous blood transfusion in scoliosis surgery. Harvesting blood from the postoperative wound.

In a prospective study in scoliosis and kyphosis surgery patients, red blood cells were harvested from the drainage of the postoperative closed wound and returned to the patient. Approximately 1 unit of blood per patient was saved compared with a historically similarly matched group who had no postoperative blood salvage. The authors conclude that the addition of postoperative autologous blood salvage can considerably reduce predeposit autologous blood requirements of patients undergoing Cotrel-Dubousset instrumentation and posterior spine fusion for spinal deformity.

Erythrocyte survival following intraoperative autotransfusion in spinal surgery: an in vivo comparative study and 5-year update.

A 5-year prospective study of intraoperative blood transfusion in 239 patients, most of whom had major spinal surgery, has been completed. Autotransfusion is safe, practical, and it reduces donor blood requirements and total blood loss by 50%. It eliminates host versus graft reactions and disease transmission. In 33 patients having major spinal surgery, the in vivo survival of autologous, homologous, and processed red blood cells (RBC) using the Cell Saver System were compared. The RBC survival studies were performed using chromium51 isotope labeling technique. The long-term survival of processed RBCs was normal over a 30-day period. There was no significant difference in the survival rate of the three groups studied.

Choosing fusion levels in progressive thoracic idiopathic scoliosis.

The selection of fusion levels in thoracic idiopathic scoliosis was subjected to multicenter retrospective review to test the validity of the classification system and recommendations of King et al. The 253 patients reviewed were treated by posterior fusion and Harrington instrumentation. Bending films were of little help in selecting fusion levels. Standing radiographs alone were usually adequate. King Type II curves may yield better lumbar correction if the lumbar curve is partially included in the fusion. Type IV curves may be safely fused one level proximal to the stable vertebrae.

Outbreak of Pasteurella pneumotropica in a closed colony of STOCK-Cd28(tm1Mak) mice.

Fifteen mice with Pasteurella pneumotropica orbital abscesses were noted in mice that were homozygous for a targeted Cd28 gene mutation. Only one mouse heterozygous for the Cd28 mutation was affected. According to phenotypic reactions and 16S rDNA sequencing, the isolates were most similar to biotype Heyl. This article provides evidence for an immunologic basis of susceptibility to P. pneumotropica infection. Fifteen mice with Pasteurella pneumotropica orbital abscesses were noted in mice that were homozygous for a targeted Cd28 gene mutation. Only one mouse heterozygous for the Cd28 mutation was affected. According to phenotypic reactions and 16S rDNA sequencing, the isolates were most similar to biotype Heyl. This article provides evidence for an immunologic basis of susceptibility to P. pneumotropica infection.

Depletion of CD4+CD25+ regulatory T cells exacerbates sodium iodide-induced experimental autoimmune thyroiditis in human leucocyte antigen DR3 (DRB1*0301) transgenic class II-knock-out non-obese diabetic mice.

Both genetic and environmental factors contribute to autoimmune disease development. Previously, we evaluated genetic factors in a humanized mouse model of Hashimoto's thyroiditis (HT) by immunizing human leucocyte antigen DR3 (HLA-DR3) and HLA-DQ8 transgenic class II-knock-out non-obese diabetic (NOD) mice. DR3+ mice were susceptible to experimental autoimmune thyroiditis (EAT) induction by both mouse thyroglobulin (mTg) and human (h) Tg, while DQ8+ mice were weakly susceptible only to hTg. As one environmental factor associated with HT and tested in non-transgenic models is increased sodium iodide (NaI) intake, we examined the susceptibility of DR3+ and/or DQ8+ mice to NaI-induced disease. Mice were treated for 8 weeks with NaI in the drinking water. At 0 x 05% NaI, 23% of DR3+, 0% of DQ8+ and 20% of DR3+DQ8+ mice had thyroid destruction. No spleen cell proliferation to mTg was observed. Most mice had undetectable anti-mTg antibodies, but those with low antibody levels usually had thyroiditis. At 0.3% NaI, a higher percentage of DR3+ and DR3+DQ8+ mice developed destructive thyroiditis, but it was not statistically significant. However, when DR3+ mice had been depleted of CD4+CD25+ regulatory T cells prior to NaI treatment, destructive thyroiditis (68%) and serum anti-mTg antibodies were exacerbated further. The presence of DQ8 molecules does not alter the susceptibility of DR3+DQ8+ mice to NaI-induced thyroiditis, similar to earlier findings with mTg-induced EAT. Susceptibility of DR3+ mice to NaI-induced EAT, in both the presence and absence of regulatory T cells, demonstrates the usefulness of HLA class II transgenic mice in evaluating the roles of environmental factors and immune dysregulation in autoimmune thyroid disease.

Synergism between nifedipine and cyclosporine A on the incorporation of [35S]sulfate into human gingival fibroblast cultures in vitro.

BACKGROUND AND OBJECTIVE: We assessed the effects of cyclosporine A and nifedipine on the in vitro incorporation of [(35)S]sulfate into gingival fibroblast cell cultures derived from responder and nonresponder subjects who had received an organ transplant followed by a therapeutic regimen using a combination of those drugs. MATERIAL AND METHODS: Gingival fibroblasts were isolated from responder and nonresponder subjects and maintained in vitro. Prior to cell harvest, gingival interleukin-1beta concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Cells were untreated or exposed to either 10(-7)-10(-10) m nifedipine or 100-500 ng/ml cyclosporine A. Incorporation of [(3)H]proline or [(35)S]sulfate into the cell cultures was determined by liquid scintillation analysis. In addition, the effects of 400 ng/ml cyclosporine A + 10(-7) m nifedipine and 400 ng/ml cyclosporine A + 10(-10) m nifedipine on incorporation of [(35)S]sulfate into the cell cultures was determined. Data were compared by factorial analysis of variance (anova) and a posthoc Tukey's test. RESULTS: Gingiva from responders contained significantly more interleukin-1beta than gingiva from nonresponders (p < 0.01). The cell cultures derived from responders incorporated significantly more [(35)S]sulfate than those derived from nonresponders following exposure to either cyclosporine A or 10(-7) m nifedipine. In addition, the exposure of fibroblasts derived from gingival overgrowth to either 400 ng/ml cyclosporine A + 10(-7) m nifedipine or 400 ng/ml cyclosporine A + 10(-10) m nifedipine significantly increased or decreased, respectively, the incorporation of [(35)S]sulfate into the cultures. CONCLUSION: The therapeutic combination of cyclosporine A and nifedipine could be a significant risk factor for gingival overgrowth in subjects susceptible to either agent. The mechanism for overgrowth could include edema secondary to increased sulfated-glycosaminoglycan (sGAG) synthesis by fibroblasts, but further investigation is required.

Perioperative autotransfusion. Avoiding donated risks.

Because of the risks associated with donated blood, although slight, intraoperative and postoperative autotransfusion is becoming the wave of the future. "Intraoperative autotransfusion," according to Ken Williamson, MD, of the Mayo Clinic, "is now a medically indicated procedure." Cost effectiveness, once raised as an objection to intraoperative autotransfusion, is no longer considered; disease prevention is paramount. Every OR nurse should become familiar with the operation of the autotransfusion machines and be able to set up such a machine and operate it in an emergency. In our institution, one OR nurse can run two machines in different operating rooms because blood loss into the orthopedic wound is usually slow. Inservice training for nurses is readily available from the manufactures' representative or distributors. All in all, nurses-especially OR nurses-must prepare to be part of the autotransfusion team in the 1990s and beyond.

Nonunion of slightly displaced fractures of the lateral humeral condyle in children: an update.

Inadequate treatment continues to be the leading cause of nonunion of slightly displaced fractures of pediatric lateral humeral condyles, despite references to prevention in the orthopaedic literature. In most cases, the elbow was established nonunion can be salvaged by early stabilization and bone grafting, provided that the fragment is in acceptable position and the growth plate of the condylar fragment is open. Procrastination may allow the physis of the condylar fragment to close prematurely, preemptying the golden opportunity to salvage the child's elbow. The author has collected 23 similar cases from correspondence with 17 orthopaedic surgeons.

In vivo evidence for CD4+ and CD8+ suppressor T cells in vaccination-induced suppression of murine experimental autoimmune thyroiditis.

In several experimental autoimmune diseases, including experimental autoimmune thyroiditis (EAT), vaccination with attenuated autoantigen-specific T cells has provided protection against subsequent induction of disease. However, the mechanism(s) of vaccination-induced suppression remains to be clarified. Since we have previously shown that suppression generated by pretreatment with mouse thyroglobulin (MTg) or thyroid-stimulating hormone in EAT is mediated by CD4+, not CD8+, suppressor T cells, we examined the role of T cell subsets in vaccination-induced suppression of EAT. Mice were vaccinated with irradiated, MTg-primed, and MTg-activated spleen cells and then challenged. Pretreatment with these cells suppressed EAT induced by immunization with MTg and adjuvant, but not by adoptive transfer of thyroiditogenic cells, suggesting a mechanism of afferent suppression. The activation of suppressor mechanisms did not require CD8+ cells, since mice depleted of CD8+ cells before vaccination showed reduced EAT comparable to control vaccinated mice. Furthermore, depletion of either the CD4+ or the CD8+ subset after vaccination did not significantly abrogate suppression. However, suppression was eliminated by the depletion of both CD4+ and CD8+ cells in vaccinated mice. These results provide evidence for the cooperative effects of CD4+ and CD8+ T cells in vaccination-induced suppression of EAT.

High density insulin receptor-positive diabetogenic T lymphocytes in nonobese diabetic mice are memory cells.

Our previous work examining the importance of insulin receptor (IR) expression on T cells has demonstrated that when T cells from nonobese diabetic mice were sorted into populations expressing a high (IR(High)) and a low (IR(Low)) density of IR, IR(High) T cells rapidly transferred insulitis and diabetes. We have further characterized IR(High) T cells. Both CD4+ and CD8+ cells were detected in the IR(High) T cell population, but IR(High) expression was detected predominantly on CD4+ cells. IRHigh T cells were polyclonal for TCR Vbeta-chain expression. By 3 color flow cytometric analysis, virtually all IR(High) T cells expressed low or negligible levels of CD62L (CD62L(Low)/-) and high levels of CD44 (CD44(High)). The lack of IL-2 receptor and transferrin receptor expression as seen previously, together with the CD62L(Low)/- CD44(High) phenotype suggests that IR(High) T cells are memory cells. However, since only about one quarter of all of the CD62L(Low)/- or CD44(High) T cells were also IR(High), the IR(High) phenotype defines a subpopulation of memory T cells that are aggressively diabetogenic.

Behavioral sequelae of bracing versus surgery for Legg-Calvé-Perthes disease.

The Louisville Behavioral Checklist was administered to 23 white boys between the ages of 7 and 12 years who completed treatment for Perthes disease by bracing or surgery at the Florida Elks Children's Hospital. The groups were comparable, with 11 children in the surgery group and 12 in the bracing group. Results indicated statistically significant differences (p = 0.05) between the groups in three areas. Patients in the bracing group were more likely to demonstrate deficits in social, academic, and sexual behavior as compared with patients in the surgery group.