Decreased bone mineral density and vertebral compression fractures in a young adult male with 21-hydroxylase deficiency congenital adrenal hyperplasia (CAH): is CAH an unrecognized population at risk for glucocorticoid-induced osteoporosis?

BACKGROUND: CAH, most often due to a molecular defect in the 21-OH enzyme, results in inadequate cortisol production and subsequent life-long GC replacement. AIMS: To heighten awareness for risk of GIO in children with CAH including (1) ongoing assessment of GC dosing, (2) screening for bone health, and (3) prophylactic measures/early intervention once GIO is identified. PATIENT: 23 year-old male with 21OHD CAH referred for osteopenia. METHODS: Chart review; radiological, serological and urine assessment. RESULTS: Patient has old vertebral compression fractures and diminished BMD, the onset of which likely corresponds to excessive GC dosing during adolescence. CONCLUSION: As with other GC-dependent conditions, children with CAH may represent a previously unrecognized population at risk for GIO. Physicians need to be cognizant of the consequences of excessive GC dosing on bone health, especially during infancy and adolescence, critical periods for both linear growth as well as bone accretion.

Approach to lipid screening as a risk marker for cardiovascular disease in pediatric patients with diabetes.

Cardiovascular disease (CVD) is a well-known complication of diabetes mellitus (DM), and patients with DM are at an increased risk for early onset of CVD. Hyperglycemia is believed to be the primary mediator in premature development of atherosclerosis in patients with DM, but there are also derangements in cholesterol levels and inflammatory markers beyond the explanation of hyperglycemia. Although clinicians often screen for dyslipidemia as part of routine care for children and adolescents with DM, many do not feel comfortable treating this condition. Multiple guidelines exist to help clinicians with the prevention, screening, and treatment of CVD risk factors in pediatric patients with DM, but the guidelines do not always agree on screening intervals or medical treatment. Furthermore, the cost-effectiveness of medication use in this population has not been established. Research has advanced our understanding of the role of other biomarkers and radiologic studies of CVD risk, but these studies do not currently have a place in routine clinical practice. It is evident that the increased CVD risk in pediatric patients with DM is complex in origin and the optimal approach to managing dyslipidemia remains unclear. Therefore, an algorithm designed at the University of North Carolina (UNC), Division of Pediatric Endocrinology, is presented to help guide clinicians through screening and treatment of dyslipidemia in youth with DM.

HLA-A2-matched peripheral blood mononuclear cells from type 1 diabetic patients, but not nondiabetic donors, transfer insulitis to NOD-scid/γc(null)/HLA-A2 transgenic mice concurrent with the expansion of islet-specific CD8+ T cells.

OBJECTIVE: Type 1 diabetes is an autoimmune disease characterized by the destruction of insulin-producing ß-cells. NOD mice provide a useful tool for understanding disease pathogenesis and progression. Although much has been learned from studies with NOD mice, increased understanding of human type 1 diabetes can be gained by evaluating the pathogenic potential of human diabetogenic effector cells in vivo. Therefore, our objective in this study was to develop a small-animal model using human effector cells to study type 1 diabetes. RESEARCH DESIGN AND METHODS: We adoptively transferred HLA-A2-matched peripheral blood mononuclear cells (PBMCs) from type 1 diabetic patients and nondiabetic control subjects into transgenic NOD-scid/γc(null)/HLA-A*0201 (NOD-scid/γc(null)/A2) mice. At various times after adoptive transfer, we determined the ability of these mice to support the survival and proliferation of the human lymphoid cells. Human lymphocytes were isolated and assessed from the blood, spleen, pancreatic lymph node and islets of NOD-scid/γc(null)/A2 mice after transfer. RESULTS: Human T and B cells proliferate and survive for at least 6 weeks and were recovered from the blood, spleen, draining pancreatic lymph node, and most importantly, islets of NOD-scid/γc(null)/A2 mice. Lymphocytes from type 1 diabetic patients preferentially infiltrate the islets of NOD-scid/γc(null)/A2 mice. In contrast, PBMCs from nondiabetic HLA-A2-matched donors showed significantly less islet infiltration. Moreover, in mice that received PBMCs from type 1 diabetic patients, we identified epitope-specific CD8(+) T cells among the islet infiltrates. CONCLUSIONS: We show that insulitis is transferred to NOD-scid/γc(null)/A2 mice that received HLA-A2-matched PBMCs from type 1 diabetic patients. In addition, many of the infiltrating CD8(+) T cells are epitope-specific and produce interferon-γ after in vitro peptide stimulation. This indicates that NOD-scid/γc(null)/A2 mice transferred with HLA-A2-matched PBMCs from type 1 diabetic patients may serve as a useful tool for studying epitope-specific T-cell-mediated responses in patients with type 1 diabetes.

Cell Cycle-Dependent Localization of Voltage-Dependent Calcium Channels and the Mitotic Apparatus in a Neuroendocrine Cell Line(AtT-20).

Changes in intracellular calcium are necessary for the successful progression of mitosis in many cells. Both elevation and reduction in intracellular calcium can disrupt mitosis by mechanisms that remain ill defined. In this study we explore the role of transmembrane voltage-gated calcium channels (CaV channels) as regulators of mitosis in the mouse corticotroph cell line (AtT-20). We report that the nifedipine-sensitive isoform CaV1.2 is localized to the "poleward side" of kinetechores during metaphase and at the midbody during cytokinesis. A second nifedipine-sensitive isoform, CaV1.3, is present at the mid-spindle zone in telophase, but is also seen at the midbody. Nifedipine reduces the rate of cell proliferation, and, utilizing time-lapse microscopy, we show that this is due to a block at the prometaphase stage of the cell cycle. Using Fluo-4 we detect calcium fluxes at sites corresponding to the mid-spindle zone and the midbody region. Another calcium dye, Fura PE3/AM, causes an inhibition of mitosis prior to anaphase that we attribute to a chelation of intracellular calcium. Our results demonstrate a novel, isoform-specific localization of CaV1 channels during cell division and suggest a possible role for these channels in the calcium-dependent events underlying mitotic progression in pituitary corticotrophs.