Citations

SUMMARYMurine experimental autoimmune thyroiditis (EAT), characterized by thyroid destruction after immunization with thyroglobulin (Tg), has long been a useful model of organ-specific autoimmune disease. More recently, porcine thyroid peroxidase (pTPO) has also been shown to induce thyroiditis, but these results have not been confirmed. When (C57BL/6 × CBA)F1 mice, recently shown to be susceptible to mouse TPO-induced EAT, were immunized with plasmid DNA to human TPO (hTPO) and cytokines IL-12 or GM-CSF, significant antibody (Ab) titres were generated, but minimal thyroiditis was detected in one mouse only from the TPO + GM-CSF immunized group. However, after TPO DNA immunization of HLA-DR3 transgenic class II-deficient NOD mice, thyroiditis was present in 23% of mice injected with TPO + IL-12 or GM-CSF. We also used another marker for assessing the closeness of the model to human thyroid autoimmunity by examining the epitope profile of the anti-TPO Abs to immunodominant determinants on TPO. Remarkably, the majority of the anti-TPO Abs was directed to immunodominant regions A and B, demonstrating the close replication of the model to human autoimmunity. TPO protein immunizations of HLA-DR3 transgenic mice with recombinant hTPO did not result in thyroiditis, nor did immunization of other mice expressing HLA class II transgenes HLA-DR4 or HLA-DQ8, with differential susceptibility to Tg-induced EAT. Moreover, our efforts to duplicate exactly the experimental procedures used with pTPO also failed to induce thyroiditis. The success of hTPO plasmid DNA immunization of DR3+ mice, similar to our reports on Tg-induced thyroiditis and thyrotropin receptor DNA-induced Graves’ hyperthyroidism, underscores the importance of DR3 genes for all three major thyroid antigens, and provides another humanized model to study autoimmune thyroid disease.

AbstractPrevious studies have demonstrated the in vitro and in vivo activity of CC-5013 (Revlimid), an immunomodulatory analog (IMiD) of thalidomide, in multiple myeloma (MM). In the present study, we have examined the anti-MM activity of rapamycin (Rapamune), a specific mTOR inhibitor, combined with CC-5013. Based on the Chou-Talalay method, combination indices of less than 1 were obtained for all dose ranges of CC-5013 when combined with rapamycin, suggesting strong synergism. Importantly, this combination was able to overcome drug resistance when tested against MM cell lines resistant to conventional chemotherapy. Moreover, the combination, but not rapamycin alone, was able to overcome the growth advantage conferred on MM cells by interleukin-6 (IL-6), insulin-like growth factor-1 (IGF-1), or adherence to bone marrow stromal cells (BMSCs). Combining rapamycin and CC-5013 induced apoptosis of MM cells. Differential signaling cascades, including the mitogen-activated protein kinase (MAPK) and the phosphatidylinositol 3′-kinase/Akt kinase (PI3K/Akt) pathways, were targeted by these drugs individually and in combination, suggesting the molecular mechanism by which they interfere with MM growth and survival. These studies, therefore, provide the framework for clinical evaluation of mTOR inhibitors combined with IMiDs to improve patient outcome in MM.

Background— Recently, we identified circulating smooth muscle progenitor cells (SPCs) in human peripheral blood. The integrin profile of such progenitors is currently unknown and may affect their in vivo homing characteristics. In this study, we determined the integrin profile of vascular progenitors and SPC adhesion to extracellular matrix (ECM) proteins in vitro and in vivo. Methods and Results— SPCs and endothelial progenitor cells (EPCs) were isolated from peripheral blood of healthy human subjects, and expression of surface integrins and adhesion to several vascular ECM proteins were determined. Homing of SPCs in vivo to specific ECM protein was determined by intracoronary infusion of fluorescent SPCs into porcine coronary arteries containing a fibronectin-coated mesh stent. SPCs had high expression of β 1 integrin, moderate expression of α 1 , low levels of α v β 3 , and did not express α v β 5 , β 2 , α 2 β 1 , or α 4 β 1 integrins. In contrast, EPCs had high expression of α 2 β 1 , α v β 3 , α v β 5 , β 1 , and α 1 and minimal expression of α 4 β 1 . Moreover, SPCs showed increased adherence to fibronectin and collagen type I compared with vitronectin, consistent with their integrin profile, and demonstrated a similar degree of in vivo attachment to fibronectin-coated mesh. Conclusions— These data for the first time show a spectrum of integrin expression on vascular progenitors and suggest the potential importance of integrins in mediating adherence of SPCs to specific ECM both in vitro and in vivo.

Background. Although glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is prevalent in African Americans, their risk of associated neonatal hyperbilirubinemia has not been prospectively studied.Objective. To compare hemolysis and the risk of hyperbilirubinemia among African American, G-6-PD-deficient neonates (study group) and G-6-PD-normal control subjects.Methods. Consecutive, healthy, term and near-term, male neonates born to African American mothers comprised the patient cohort. G-6-PD testing was performed with umbilical cord blood samples. Routine management included measurement of the end tidal carbon monoxide level corrected for ambient carbon monoxide level (ETCOc) within 4 hours after delivery (assessment of hemolysis), ≥1 predischarge bilirubin determination, and additional bilirubin testing as clinically indicated. Indications for phototherapy were identical for study patients and control subjects. Neonates were monitored for the first 1 week of life. ETCOc results, the incidence of hyperbilirubinemia (defined as a transcutaneous or plasma total bilirubin concentration of ≥95th percentile for the hour of life), and the need for phototherapy were compared between the G-6-PD-deficient and G-6-PD-normal groups.Results. Five hundred male patients were enrolled, of whom 64 (12.8%) were G-6-PD-deficient. ETCOc values (median and interquartile range) were higher among G-6-PD-deficient neonates than among control neonates (2.4 ppm [2.0–2.9 ppm] vs 2.1 ppm [1.7–2.5 ppm]). More G-6-PD-deficient neonates developed hyperbilirubinemia than did control subjects (14 of 64, 21.9%, vs 29 of 436, 6.7%; relative risk: 3.27; 95% confidence interval: 1.83-5.86), whereas 13 (20.3%) met the criteria for phototherapy, compared with 25 control subjects (5.7%) (relative risk: 3.53; 95% confidence interval: 1.91-6.56). No cases of kernicterus were observed.Conclusions. Within the African American neonatal population, there is a subgroup of G-6-PD-deficient infants with elevated rates of hemolysis, a higher incidence of hyperbilirubinemia, and a greater requirement for phototherapy, compared with G-6-PD-normal control subjects. These newborns should be monitored vigilantly for the development of hyperbilirubinemia.

Objective. In a prospective study of children with a family history of asthma, asthma onset by 3 years of age was found previously to be positively associated with variables from the first year of life, including elevated total immunoglobulin E (IgE), frequent respiratory infections, and parenting difficulties. We followed this cohort of genetically at-risk children to investigate the relationship between factors assessed in infancy and asthma, allergy, and psychological status at school age. Methods. A cohort of 150 children who were at risk for developing asthma were identified prenatally on the basis of the mothers' having asthma. For 28 children, the father had asthma as well, putting them at bilateral genetic risk. Families primarily were middle and upper middle class Caucasians. Parents came to the clinic during the third trimester of pregnancy for assessments of medical and psychosocial functioning. A home visit took place when the infant was 3 weeks old, when parenting risk was assessed before the onset of any asthma symptoms. Parenting difficulties included problems with infant caregiving as well as components of maternal functioning, such as postpartum depression and inadequate marital support. Blood was drawn for serum IgE at 6 months of age. Parents and offspring subsequently came to the clinic multiple times, with the last clinic visit during the child's sixth year. Follow-up at age 6 involved a clinic visit for allergy and psychosocial evaluations, consisting of interviews and a behavior questionnaire. Seventy-seven children received the allergy and psychosocial evaluation, 26 received the psychosocial evaluation in the clinic, and 30 families received telephone interviews and mailed in questionnaires. Additional monitoring of families by telephone and mail was maintained over the next 2 years, until the children were 8, to ensure accurate characterization of the course of illness. Comprehensive medical records were obtained and reviewed for all health care contacts. Children were designated as having asthma when there was documentation in medical records of physician-diagnosed asthma, observed wheezing, and/or prescription of asthma medications during the time period when the child was between 6 and 8 years of age. Parental reports of the occurrence of asthma corroborated the medical record data. Results. Data regarding asthma status were available for 145 children through 8 years of age. Forty (28%) of the children manifested asthma between 6 and 8 years of age. Among variables previously reported to predict asthma onset by age 3, 3 proved to have significant univariate relationships with asthma between ages 6 and 8: elevated IgE levels measured when the children were 6 months of age, global ratings of parenting difficulties measured when infants were 3 weeks old, and higher numbers of respiratory infections in the first year of life. Among these offspring of mothers with asthma, paternal asthma showed a significant association with asthma between ages 6 and 8. Eczema in the first year was not significantly related to later asthma. Multiple logistic regression showed that the model that best predicted asthma at ages 6 to 8 from infancy variables included 2 main effects. The adjusted odds ratio for 6-month IgE was 2.15 (1.51, 3.05) and for parenting difficulties was 2.07 (1.15, 3.71). Although socioeconomic status (SES) was not associated with asthma at ages 6 to 8, families of lower SES were more likely to be rated as having parenting difficulties early in the child's life. The mothers of lower SES breastfed for a shorter period of time and were more likely to smoke during their infant's first year. There were more respiratory infections during the first year of life among infants whose mother was rated as having more parenting difficulties. Mothers who reported smoking breastfed their infants for a shorter length of time. Male gender was significantly associated with higher IgE levels when infants were 6 months of age. Laboratory testing was completed for 77 children at age 6. Total serum IgE levels were significantly higher for the children with asthma between ages 6 and 8. Skin-prick testing showed that the children with asthma had significantly more positive skin test reactions than did the children without asthma. Psychosocial interview data at 6 years of age were available for 103 families, and behavioral questionnaires were available for 133 families. On the basis of 6-year interviews, children with asthma were rated as being at greater psychological risk than were the children without asthma. Mothers' Child Behavior Checklist (CBCL) ratings of their children's behavior indicated higher internalizing scores for the children with asthma as compared with the children without asthma. Like the 6-month IgE, 6-year IgE was higher for boys. IgE levels measured at 6 months of age were significantly correlated with 6-year IgE levels. Parenting difficulties measured at 3 weeks were significantly correlated with 6-year measures of maternal depression, CBCL Internalizing score, and Child Psychological Risk (CPR) score. There also were significant correlations among the psychosocial variables assessed when the children were 6 years of age; maternal depression was significantly associated with child CBCL Internalizing score and CPR score, and the last 2 also were significantly correlated. Multiple logistic regression showed that 2 concurrently measured variables entered the model showing the strongest associations with asthma at ages 6 to 8. The adjusted odds ratio for CPR score was 3.21 (1.29–7.96) and for 6-year IgE was 1.71 (1.04–2.80). Conclusions. This study of the natural history of childhood asthma focused on the development of asthma into the school-age years in a genetically at-risk group of children. The relationships between biological and psychosocial variables in the first year and school-age asthma support the formulation of asthma as beginning early in life, with the developing immune system interacting with environmental influences. The data provide support for the possible contribution of psychosocial factors to asthma onset and persistence into childhood.

Objective. To determine whether children with pallid breath-holding spells associated with bradycardia can be treated safely and successfully with permanent pacemaker implantation. Methods. The records of pediatric patients who had apparent breath-holding spells and associated bradycardia and were treated with permanent pacemaker implantation were reviewed. Results. Ten pediatric patients with apparent breath-holding spells associated with bradycardia were treated with a permanent ventricular demand pacemaker at the Mayo Clinic between 1985 and 1995. Patients had onset of symptoms between ages 6 days and 12 months and presented for evaluation between ages 12 months and 5 years. Duration of spells was 15 seconds to 10 minutes. Medications to prevent spells were unsuccessful. Electrocardiograms documented asystolic pauses of 1.7 to 24 seconds (mean: 11.9 seconds). Permanent ventricular demand pacemakers were implanted at 10 months to 5 years of age (median: 14.5 months): 9 endocardial and 1 epicardial. Three patients required pacemaker revision. At follow-up of 38 to 170 months (median: 65.5), 5 patients had complete resolution of spells, 2 had only mild color change without loss of consciousness or seizure activity, and 3 continued to have minor brief spells. Conclusions. Permanent pacemaker therapy for children with pallid breath-holding spells associated with severe bradycardia is safe, efficacious, and warranted.