• Modulation of Tumor Tolerance in Primary Central Nervous System Malignancies

      Johnson, Theodore S.; Munn, David H.; Maria, Bernard L.; Department of Pediatrics; Immunotherapy Center; GHSU Cancer Center (2012-01-24)
      Central nervous system tumors take advantage of the unique immunology of the CNS and develop exquisitely complex stromal networks that promote growth despite the presence of antigen-presenting cells and tumor-infiltrating lymphocytes. It is precisely this immunological paradox that is essential to the survival of the tumor. We review the evidence for functional CNS immune privilege and the impact it has on tumor tolerance. In this paper, we place an emphasis on the role of tumor-infiltrating myeloid cells in maintaining stromal and vascular quiescence, and we underscore the importance of indoleamine 2,3-dioxygenase activity as a myeloid-driven tumor tolerance mechanism. Much remains to be discovered regarding the tolerogenic mechanisms by which CNS tumors avoid immune clearance. Thus, it is an open question whether tumor tolerance in the brain is fundamentally different from that of peripheral sites of tumorigenesis or whether it simply stands as a particularly strong example of such tolerance.
    • Non-invasive Biomarkers to Detect Acute Kidney Injury in Premature Infants

      Marin, Terri; Williams, Bryan; Bhatia, Jatinda; Sharma, Ashok; Mundy, Cynthia; Cockfield, Christy; College of Nursing; Department of Pediatrics: Neonatology; Department of Population Health Science; Department of Obstetrics and Gynecology; et al.
    • Novel Therapeutic Approaches to Leishmania Infection

      Makala, Levi HC; Baban, Babak; Department of Pediatrics; Department of Oral Biology (InTech, 2014-03-19)
      Leishmaniasis is a parasitic disease transmitted by phlebotomine sandflies. Approximately 1.2 million cases of cutaneous leishmaniasis (CL) and 500,000 cases of visceral leishmaniasis (VL), which is lethal if untreated, occur annually across the globe as per world health organization (WHO) estimates [1-3]. Current statistics and information relevant to leishmaniasis are summarized in Table 1. Leishmaniasis currently affects about 12 million people and it is estimated that approximately 350 million people live in risk of infection [1-3].The number of cases of leishmaniasis is probably underestimated because only 40 of the 88 countries where diseases frequently occur report them on a regular basis [4]. Leishmaniasis, is caused by several leishmania spp., that are obligate intracellular and unicellular kinetoplastid protozoan flagellate that establish themselves within the phagolysosome of host immune competent cells, especially macrophages and dendritic cells (DCs). In 1903, W.B. Leishman and C. Donovan reported this new parasite at the turn of the century [5,6]. Ronald Ross christened the new genus leishmania and the new species donovani in year 1903 [7]. L. major infection (leishmaniasis) in mice is a widely used model of human infection that has yielded critical insights into the immunobiology of leishmaniasis [8-10]. Leishmaniasis as a parasitic disease manifests itself mainly in 3 clinical forms; visceral leishmaniasis (VL), cutaneous leishmaniasis (CL) and mucocutaneous leishmaniasis (MCL), of which VL is the most severe form of the disease. VL is lethal if untreated and spontaneous cure is extremely rare. Cutaneous leishmaniasis usually has milder course and often results into a self-healing of ulcers. Resolution of leishmanial infection is dependent on the coordinated interactions between components of cell mediated immune response, specifically the activation of targeted T-cell populations for appropriate cytokine production and activation of macrophages. L. major infection of B6 and BALB/c mouse strains drives predominantly TH1 and TH2 responses, respectively [11-14]. In murine model, the development of Th1 response is associated with control of infection, and Th2 response is associated with disease progression. However, Th1 and Th2 dichotomy in the human system is not as distinct as in mice and the murine model does not strictly apply to human leishmaniasis.
    • Review of Outcome Information in 46,XX Patients with Congenital Adrenal Hyperplasia Assigned/Reared Male: What Does It Say about Gender Assignment?

      Lee, Peter A.; Houk, Christopher Phil; Department of Pediatrics (2010-12-21)
      There is ample historical verification of 46,XX congenital adrenal hyperplasia (CAH) patients being born with essentially male genitaliawhile outcome information is scant. Prior to glucocorticoid therapy, most patients died very young from adrenal insufficiency. Most available reports from laterchildhood, contain little information concerning sexual identity. Reports on older individuals lack adequate information about sexual identity and quality of life. The difficulty in assessing the relative impact of multiple dynamic environmental factors on the development of sexual identity, self- and body esteem and overall adjustment to life is clear. Nevertheless, it remains unclear whether those infants whose masculine genitalia at birth resulted in an initial male assignment would have enjoyed a better adult outcome had they been allowed to remain male rather than the female reassignment that most received. Further, one could ask whether a male sex of rearing should be considered in 46,XX CAH infants with male external genitalia. After reviewing available literature, we conclude that because those extremely virlized 46,XX CAH patients who were reared male with healthy social support demonstrated satisfactory levels of social and sexual function as adults a male sex assignment should be considered in these types of infants when social and cultural environment are supportive.
    • The role of indoleamine 2, 3 dioxygenase in regulating host immunity to leishmania infection

      Makala, Levi HC; Department of Pediatrics (2012-01-9)
      Pathogen persistence in immune-competent hosts represents an immunological paradox. Increasing evidence suggests that some pathogens, such as, Leishmania major (L. major) have evolved strategies and mechanisms that actively suppress host adaptive immunity. If this notion is correct conventional vaccination therapies may be ineffective in enhancing host immunity, unless natural processes that suppress host immunity are also targeted therapeutically. The key problem is that the basis of pathogen persistence in immune-competent individuals is unknown, despite decades of intense research. This fact, coupled with poor health care and a dearth of effective treatments means that these diseases will remain a scourge on humans unless a better understanding of why the immune system tolerates such infections emerges from research. Indoleamine 2,3-dioxygenase (IDO) has been shown to act as a molecular switch regulating host responses, and IDO inhibitor drugs shown to possess potential in enhancing host immunity to established leishmania infections. It is hoped that this review will help stimulate and help generate critical new knowledge pertaining to the IDO mechanism and how to exploit it to suppress T cell mediated immunity, thus offer an innovative approach to studying the basis of chronic leishmania infection in mice.
    • The role of support groups, advocacy groups, and other interested parties in improving the care of patients with congenital adrenal hyperplasia: pleas and warnings.

      Lee, Peter A.; Houk, Christopher Phil; Department of Pediatrics (2010-07-23)
      In the era of advocacy groups, it seems appropriate to contemplate how best to utilize them for patient benefit in the management of those with disorders of sex development (DSD), including those with congenital adrenal hyperplasia (CAH). Such interactions, to be constructive, require a spirit of cooperation to optimize outcomes. A traditional view of advocacy groups as a type of defender of patients' rights appears outdated and it is time that the benefits of their participation be fully realized. Open dialogue with all patients/families, including those who feel harmed by prior care are paramount. We discuss several recent examples of interactions that illustrate how dialogue in the name of "advocacy" can have a negative impact on developing a framework for ongoing constructive dialogue and actions. Such approaches completely change the dynamics of subsequent interactions. Physicians involved in the care of individuals with DSD, including those with CAH, and patients should be aware of confrontational techniques and legal implications that may be used by some advocacy groups. Hopefully recent efforts to promote a multidisciplinary care approach for patients with DSD/CAH will continue to foster mutual cooperation between team members, where the common goal is improving patient/family outcomes and quality of life.
    • Sickle Cell Disease: Genetics, Cellular and Molecular Mechanisms, and Therapies

      Pace, Betty S.; Ofori-Acquah, Solomon F.; Peterson, Kenneth R.; Department of Pediatrics (2012-08-22)
    • Unnecessary Workup of Asymptomatic Neonates in the Era of Group B Streptococcus Prophylaxis

      Buckler, Brad; Bell, Jason; Sams, Ralph; Cagle, William; Bell, Sue Anne; Allen, Carla; Sutherland, Donald E.; Bhatia, Jatinder; Department of Pediatrics; Department of Pediatrics; et al. (2010-08-22)
      Asymptomatic term neonates born to mothers who are Group B Streptococcus (GBS) unknown or GBS positive but â inadequatelyâ treated prior to delivery do not require invasive laboratory evaluation. We conducted a retrospective cohort study of mother/baby dyads born from January 1, 2005 until September 30, 2007 at the Medical College of Georgia. Their current protocol is to obtain a Complete Blood Count with Differential (CBC with D), Blood Culture (BC), and C-reactive protein (CRP) after birth. Mother/baby dyads (n = 242) that met inclusion criteria were reviewed. Of these 242 babies 25 (10%) were started on antibiotics after the initial lab values were known. None of the blood cultures were positive and the CRP's were normal. The 2002 GBS guidelines call for laboratory evaluation of â at-riskâ neonates, but the workup of these babies is not only costly, it does not provide any advantage over old fashioned clinical observation for the evaluation and treatment of early onset GBS sepsis.